RIKEN
Accelerator
Progress Report
vol. 48

国立研究開発法人理化学研究所

仁科加速器研究センター

RIKEN Nishina Center for Accelerator-Based Science

RIKEN Accelerator Progress Report

vol. 48

国立研究開発法人理化学研究所 仁科加速器研究センター
RIKEN Nishina Center for Accelerator-Based Science
Wako, Saitama, 351-0198 JAPANRIKEN Accelerator Progress Report 2014 vol.48
This is an unabridged version of the 48th volume of RIKEN Accelerator Progress Report(hereinafter referred to as APR), the official annual report of the Nishina Center for
Accelerator-Based Science.
A PDF version of APR can be downloaded from our website.
http://www.nishina.riken.jp/researcher/APR/index_e.html

Published by
RIKEN Nishina Center for Accelerator-Based Science
2-1 Hirosawa, Wako-shi, Saitama 351-0198 JAPANDirector of RIKEN Nishina Center for Acclerator-Based Science
Hideto En’yo
Editorial Board
T. Uesaka (chairperson), T. Abe, H. Haba, K. Hashimoto, E. Hiyama, T. Ichihara, Y. Ichikawa, T. Ikeda, H. Imao, N. Inabe,
K. Ishida, T. Isobe, T. Kanazawa, A. Kohama, K. Morimoto, H. Otsu, R. Seidl, T. Tada, K. Takahashi, T. Tamagawa,K. Tanaka, M. Wada, J. Zenihiro, T. Gunji, H. Ishiyama, S. Goto, K. Iwai, and T. Okayasu
Contact
Progress@ribf.riken.jp
All rights reserved. This report or any portion thereof may not be reproduced or used in any form, including photostatic
print or microfilm, without written permission from the Publisher.
Contents of the manuscripts are the authors' responsibility. The Editors are not liable for the content of the report.
RIKEN Nishina Center for Accelerator-Based Science, October 2015

PREFACE
The readers of RIKEN Accelerator Progress Report (APR) must have realizedthat we have stopped sending you a thick volume of papers. Instead, you now
receive a compilation of the gravure and the highlights of the year with informationof a web page where you can download a full set of the articles. While such change
has been made to adapt to the changing times, it may make the readers of the older
generation miss the good old times.
Nevertheless, when you pick up a thin booklet of the latest APR, please look
into one of the highlights, “RI beam production at BigRIPS in 2014” written by N.
Fukuda and his coauthors. From the impressive nuclear chart showing the history
of RI beam production, you will learn that from March 2007 to December 2014,
140 new isotopes were discovered at BigRIPS, and that the production yields were
measured for more than 1,000 isotopes. A total of 89 experiments have been
performed so far. The Nishina Center is proud of these accomplishments and all themembers who have contributed to this remarkable achievement must be applauded.
According to the BigRIPS compilation, the most popular primary beam is without a doubt uranium-238, and the close
second is calcium-48. Containing 20 protons and 28 neutrons, calcium-48 is the so-called doubly magic nucleus. It is very
neutron rich but its life time is 43 quintillion (1018) years, much longer than the life of the universe (14 billion years). This
is why there still exists natural calcium-48, but since its quantity totals only 0.18% of all the calcium, it is very expensive.
Calcium-48 is our key tool to study the nuclear region called “island of inversion” and to find out where a neutron drip line
for fluorine (F), neon (Ne), sodium (Na) etc. is. In 2014, our Ion Source Team succeeded in the calcium-48 ion production
which is highly budget-friendly. As highlighted in this volume of APR as “Supply of 48Ca beam from 18-GHz ECRIS using
the micro-oven” by K. Ozeki and his coauthors, the consumption of calcium-48 has been reduced by nearly a factor of 10
and the stability of the ion source has much improved. One should acknowledge that such behind the scene effort is essential
for our beam performance.
Other important subject which became quite visible at the RIKEN RI Beam Factory in 2014 is nuclear chemistry. Withthe third event of element 113 observed in the summer of 2012, the search for 113th element was concluded which propelled
us to take the next step forward, i.e. to begin search for element 119 and 120. With this shift, a long-waited research fornuclear chemistry of super-heavy elements came into full swing. There are two outstanding reports in this APR, “Firstchemical synthesis and investigation of Sg(CO)6” by J. Even et al. and “Results of first online tests of small ion-surfing RF
carpet gas cell at GARIS-II” by P. Schury et al.. The former determined that seaborgium belongs to the 6th family chemically,
and the latter revealed the powerful potential of GARIS-II in its application to super heavy element chemistry whencombined with the RF carpet technology developed to slow RIs down for high precision measurements. I believe superheavy chemistry has moved into an unexplored new stage of research.
The year 2014 was the landmark year for the Nishina Center in that it made a shift toward a new direction in response to
the needs of today’s society. We have started two governmental projects, ImPACT (Impulsing Paradigm Change throughDisruptive Technologies) program titled “Reduction and Resource Recycle of High Level Radioactive Wastes with Nuclear
Transmutation” and SIP (Strategic Innovation Promotion) program titled “Technology for creating next-generation forestry,
agriculture and fisheries”, both of which are based on our long time bottom-up efforts and activities. By initiating thesegovernmental projects, we have declared to the society that we will give back to the community our research results.
In spite of such impressive progress made in the Nishina Center however, it was truly unfortunate that the entire
JFY2014 had to be spent on complying with RIKEN’s countermeasures against the STAP incident, a serious scientificmisconduct that occurred at the RIKEN Center for Developmental Biology. I apologize for any inconveniences you have had
to deal with. I must, however, repeat once again what I had wrote in the preface of APR2013. If any similar incident everoccurred at the Nishina Center, the Center would cease to exist. We thus declare that we will never let such an incident
happen in our field.
Hideto En'yo

Director,
RIKEN Nishina Center for Accelerator-Based Science

E U R I CA!

~ Secrets Revealed via Decay Spectroscopy of Exotic Nuclei ~EURICA: A state-of-the-art decay spectrometer~ Exploring exotic nuclei with high-efficiency andhigh-resolution equipment ~The RIBF in Japan, one of the world’ s most powerfulradioactive beam facilities, has been providing intense
beams of exotic nuclei since 2007. Following the successof the first decay spectroscopy experiments in 2009, which
focused on the study of neutron-rich nuclei with masses ofaround A = 100-117, a world-class decay project called
EURICA (Euroball-RIKEN Cluster Array)† was launchedowing to the efforts of 190 international collaborators. This

state-of-the-art spectrometer, which consists of twelve
Euroball HPGe cluster detectors (formerly GSI RISING) andthe highly-segmented RIKEN β-ray detector WAS3ABi,
markedly improves the performance of high-resolution
decay spectroscopy of exotic nuclei with fast radioactive
beams. EURICA has been in operation since 2012, and has
harvested the decay properties of several hundred exotic
nuclei. The lifetimes and level schemes of isotopes
produced in BigRIPS can be deduced by measuring thetimes of flight, trajectories, and energies of the isotopes,
and their subsequent β and γ rays emitted in the β-γ decay.

β-decay half-lives and nuclear astrophysics~ How and where were the heavy elements produced in the universe? ~The β-decay half-lives of isotopes withproduction rates as low as several events per
day were measured using the EURICA
spectrometer. In the fall of 2012, thehalf-lives of neutron-rich nuclei in thevicinity of 78Ni (Z=28, N=50) were
investigated using WAS3ABi, a device thatconsists of 8 layers of double-sided
silicon-strip detectors (shown in the image
on the right). The results are summarized in
Figure 1. The systematics of the half-lives
indicate a sudden decrease beyond N=50
(79,80Ni) and below Z=28 (77Co), thus
76,77
81
providingevidence
for a doubly
Co, 79,80
Ni 78androbustCu:experimental
magic Ni. 78 †ion of doubly magicNisso,∗2 F. Browne,∗3,∗2 P. Doornenbal,∗2 G. Gey,∗4,∗5,∗2 H.-S. Jung,∗6
rström,∗2 T. Sumikama,∗8 J. Taprogge,∗9,∗10,∗2 Zs. Vajta,∗11,∗2
K. Yoshinaga,∗14 H. Baba,∗2 S. Franchoo,∗15 T. Isobe,∗2 P. R. John,∗16urz,∗17 I. Matea,∗15 K. Matsui,∗1 D. Mengoni,∗16 P. Morfouace,∗15
bata,∗13 A. Odahara,∗13 E. Şahin,∗20 H. Sakurai,∗1,∗2 H. Schaffner,∗17
an,∗15 D. Suzuki,∗15 R. Taniuchi,∗1 and V. Werner∗19

t. 113, 032505

N2P3

Dame

103

Half-life (ms)ution aroundh nuclei, i.e.,
for the firstart of an EUKEN in 2012.
ted up to an
lotron accelck beryllium
flight fission.
erage current. During the
4 78
Ni nuclei
mental decay
trometer.
s (solid sympen symbols)
e to the fifthts Qβ value,
and the neuxpected phehly in an isolearly visible
reduction iso the shorter
systematics
79,80
Ni could
N = 50 shell,ecay rates of

Figure 1: Experimental half-lives as afunction of neutron number for the
Z=27–31 isotopic chains. The filled
and open symbols represent half-lives
measured by EURICA and otherexperimental setups, respectively.

102
31Ga
30Zn

29Cu

10

28Ni

27Co

44

46
48
Neutron number

50

52

The decay properties of exotic nuclei are also key to uncovering some of the long-standing mysteries ofFig. 1. Experimental half-lives as a function of neutron
the astrophysical rapid-neutron capture process (r-process), namely, the main astronomical site(s) and its
number for isotopes with Z = 27 − 31. All the solidmechanism.
The r-process
is adeterminedsequence inofthis
neutron-captureand β-decay processes that is known to besymbols represent
the half-lives
work
responsible
for thesynthesis
approximately
while the open
symbols
are theof
half-lives
taken fromhalf
the of the elements heavier than iron. Nuclear physics
1–4)
neutron-capture
rates, β-decay half-lives, and β-delayed neutron
inputs,for example,
masses(Qin
literature. Thenuclear
systematic
trendsdifferentβ ),theisotopicprobabilities
chains are highlighted
lines connecting
theemissionof verybyneutron-richnuclei,are expected to play a significant role in thedata points witha smaller
uncertainty.
understandingof themechanismand site(s) of the r-process. Figure 2 summarizes the nuclei surveyed
with EURICA at the RIBF. A first attempt to study the universality of the astrophysical r-process was
performed by measuring the β-decay half-lives of 110 neutron-rich nuclei around mass A=100-140,
In addition, a large gap can be noticed in Fig. 1
where
the first
between40thehalf-lives
half-lives wereof the measured
Co and Ni forisotopesfrom time. As shown in Figure 3, the reaction-network
calculationsofsupernova
nucleosynthesis
withthe new half-lives indicate that the (n,γ)↔(γ,n) equilibrium
N = 44 to N = 50. According to shell model calcuislations,still valid,andreproduces
theuniversalityofthethis can be explained by the filled proton f7/2elements with Z > 56.
single particle orbit (SPO) in Ni isotopes. In this case,the proton produced in the β decay of Ni isotopes fills
the πf5/2 SPO above πf7/2 , leading to a reduction of
the Qβ value and longer half-lives of Ni isotopes thanthose of Co isotopes. The newly measured half-lives of76,77
Co follow the decreasing trend with considerable

Figure 2: Summary of the nuclei surveyed with EURICA, where known half-lives are presented incolor. The open circles indicate the data collected prior to the Kr beam campaign in 2015. The results
are presented in S. Nishimura et al. PRL 106, 052502 (2011), Z.Y. Xu et al. PRL 113, 032505 (2014),
and G. Lorusso et al. PRL 114, 192501 (2015).

st

1 PeakTheoretical Prediction
with new half-lives (RIBF)

nd

2 Peak130rdXe

3 Peak

r-process element

195

Pt

Rare earth
232

Th
238

U

80

100

120

140

160

180

200

220

240

Mass A
Figure 3: Abundances of r-process elements compared with estimations of reaction-network
calculations of supernova nucleosynthesis.

Magicity and deformation~ The magic numbers 28, 50, and 82, and regions far from the valley of stability ~Understanding nuclear shell structure and its evolution toward the drip-lines is one of the major
topics in nuclear structure research as well as nuclear astrophysics. One of the main goals of
EURICA is to study the shell gaps around the doubly magic nuclei 78Ni (Z=28, N=50), 132Sn (Z=50,
N=82), and 100Sn (Z=50, N=50), where a possible weakening of the magicity and shell quenchingeffects have been discussed. Figure 4 provides a compilation of the energies of the first excited statesin even-even nuclei obtained via γ rays from isomers and β-delayed γ rays from daughter nuclei. In
addition, detailed level schemes were deduced for 116,118Ru, 129In, and 131In via the β-delayed γ raysof 116,118Tc, 129Cd, and 131,132Cd, respectively, and long-lived isomers in 126Pd and 131Cd wereidentified via internal conversion. Some of the EURICA results from 2012 are related to low-lying
states in neutron-rich nuclei that contribute to the formation of the r-process peak around mass
A~130. Further systematic studies on shell evolution of both neutron- and proton-rich nuclei havebeen conducted using β-γ spectroscopy with EURICA at the RIBF and will be reported in the future.

P.-A. Söderström et al.
PRC C 88, 024301 (2013)

136

Sn

H. Watanabe et al.
PLB 704, 270 (2011)

G. Simpson et al.
PRL 113, 132502 (2014)

T. Sumikama et al.
PRL106, 202501 (2011)
H. Watanabe et al.
PRL111, 152501 (2013)
PRL 113, 042502 (2014)

126

Pd

128

Pd

136

Sn

138

Sn

Figure 4: Overview of first excited state energies in even-even nuclei obtained via γ rays from isomers
and β-delayed γ rays from daughter nuclei.

†EURICA was supported by the EUROBALL Owners Committee for the loan of the germanium
detectors, and the PreSpec collaboration for the use of the readout electronics. WAS3ABi was partly
funded by the Priority Centers Research Program in Korea (2009-0093817). Ten international Ph.D.
students participating in the EURICA collaboration were supported by RIKEN IPA (International
Program Associates).

CONTENTS

RIKEN Accel. Prog. Rep. 48 (2015)

C

O

N

T

E

N

T

S
Page

PREFACEEURICA! ~ Secrets Revealed via Decay Spectroscopy of Exotic Nuclei ~Ⅰ. HIGHLIGHTS OF THE YEAR
1p3/2 Proton-Hole State in 132Sn and Shell Structure Along N=82
J. Taprogge et al.

1

Isomer decay spectroscopy of 164Sm and 166Gd: mid-shell collectivity around N=100
Z. Patel et al.

2β-Decay half-lives of 76,77Co, 79,80Ni and 81Cu: experimental indication of doubly magic 78Ni
Z. Y. Xu et al.

3

Intermediate-energy Coulomb excitation of 104Sn: Moderate E2 strength decrease approaching 100Sn
P. Doorenbal et al.

4First campaign of the SEASTAR project
P. Doornenbal et al.

5

Fragmentation of 137Cs and 90Sr on proton and deuterium
H. Wang et al.

6

Missing-mass spectroscopy of tetra-neutron system via exothermic double-charge exchange reaction 4He(8He,8Be)4n
K. Kisamori et al.

7

Laser-RF double resonance spectroscopy of 84-87Rb isotopes trapped in superfluid helium
X.F. Yang et al.

8

RI beam production at BigRIPS in 2014
N. Fukuda et al.

9

Neutron drip-line search using 48Ca beam
N. Inabe et al.

11High-resolution hadronic-atom X-ray spectroscopy with superconducting transition-edge-sensor microcalorimeters
S. Okada et al.

12

Measurement of high-pT neutral mesons with a high-energy photon trigger in ALICE
S. Yano and K. Shigaki

13

Transverse single-spin asymmetries in prompt photon production from proton-proton collisions
D. Pitonyak et al.

14

Entanglement entropy of de Sitter space α-vacua
N. Iizuka, T. Noumi, N. Ogawa

15

Current Reflection and Transmission at Conformal Defects: Applying BCFT to Transport Process
T. Kimura and M. Murata

16

Magneticfield of the slowest rotating neutron star in the symbiotic X-ray binary 4U 1954+319
T. Enoto et al.

17

Short-term spectral softening of black-hole binary Swift J1753.5-0127
A. Yoshikawa et al.

18

Installation of return BT line from IRC
Y. Watanabe et al.

19

Supply of 48Ca beam from 18-GHz ECRIS using the micro-oven
K. Ozeki et al.

20

Particle identification for Sn region with SAMURAIJ. Yasuda et al.

21

Results of first online tests of small ion-surfing RF carpet gas cell at GARIS-Ⅱ
P. Schury et al.

22Electron scattering spectrometer for the SCRIT project
K. Tsukada et al.

23

Measurement of isochronism using α-source for the Rare RI Ring
Y. Abe et al.

24Time-stamping system for nuclear physics experiments at RIKEN RIBF
H. Baba et al.

25

First chemical synthesis and investigation of Sg(CO)6
J. Even et al.

26

RIKEN Accel. Prog. Rep. 48 (2015)

CONTENTS

Ⅱ. RESEARCH ACTIVITIES I (Nuclear, Particle and Astro-Physics)
1. Nuclear Physics
Long-lived isomer in 126Pd
H. Watanabe

27

Yrast 6+ Seniority Isomers of 136,138Sn
G. Simpson et al.

28

Gamma-Spectroscopy around 100Sn
J. Park and D. Lubos

29

Identification of a millisecond isomeric state 129Cd via the detection of internal conversion and Compton electrons
J. Taprogge et al.

30

Study of shape evolution in neutron-rich Cs isotopes using β-decay spectroscopy
A. Yagi et al.

31

Shell evolution in neutron-rich Te isotopes beyond doubly magic 132Sn
P. Lee et al.

32

Decay spectroscopy of neutron-rich Z ≈ 60 isotopes
E. Ideguchi et al.

33

Investigation of octupole correlations of neutron-rich Z ~ 56 isotopes through β-γ spectroscopy
R. Yokoyama et al.

34

Decay spectroscopy of neutron-rich rare-earth isotopes
P-A Söderström et al.

35

Rotational level structure of sodium isotopes inside the “Island of Inversion”
P. Doornenbal et al.

36

In-beam γ-ray spectroscopy of 50Ar
D. Steppenbeck et al.

37

Experimental study of isoscalar and isovector dipole resonances in neutron-rich oxygen isotopes
N. Nakatsuka et al.

38

Study of the pygmy-dipole resonances of 132Sn and 128Sn in inelastic α-scattering
J. Tscheuschner, T. Aumann et al.

39

Coulomb excitation of 130Cd
H. Wang, N. Aoi et al.

40

Search of E1 strength around threshold in 70Ni
R. Avigo, O. Wieland et al.

41

Structure at and beyond the dripline in the vicinity of the N=14 and 16 sub-shell closures
S. Leblond et al.

42

Study of neutron-unbound states of 19C at SAMURAIJ. Hwang et al.

44

Measurement of unbound states in 17C at SAMURAI
S. Kim et al.

45

Detailed analysis of tracking detectors for SAMURAI08 experiment
S. Koyama et al.

46

Fission Barrier Studies of Neutron-Rich Nuclei via the (p,2p) Reaction: Status of NP1306-SAMURAI-14 Experiment
D. Muecher, S. Reichert et al.

47

Identification of fission fragments from tracks measured by the FDC1
S. Reichert et al.

48

Analysis status of the experiment on fission associated with the (p,2p) reaction with 238U beam
M. Sako et al.

49

Study of Neutron-Proton Correlations & 3N Forces in 12C
H. N. Liu et al.

50

Measurement of the 132Sn(p, n) reaction at 270 MeV/nucleon
M. Sasano et al.

51

Experimental study on neutron-neutron correlation in Borromean nuclei via the (p, pn) reaction at intermediate energy with the SAMURAI
spectrometer
Y. Kubota et al.

52

Simulations for experimental studies of breakup reactions on neutron-deficient isotopes relevant to the astrophysical rp-process
V. Panin et al.

53

Future plan to study light nuclei near the neutron drip line via charge-exchange (p,n) reactions in inverse kinematics
L. Stuhl et al.

54

Spin-dipole response of 4He by using (8He, 8Li(1+))
H. Miya et al.

55

CONTENTS

RIKEN Accel. Prog. Rep. 48 (2015)

Spectroscopy of Single-Particle States in Oxygen Isotopes via AO( →p, 2p) Reaction with Polarized Protons
S. Kawase et al.

56

Status on residual analysis of SHARAQ04 experiment
T.L. Tang et al.

57

Parity-transfer reaction for study of spin-dipole 0− mode
M. Dozono et al.

58

Direct mass measurements of neutron-rich Ca isotopes beyond N = 34
M. Kobayashi et al.

59

Gamma-ray detector array for isomer tagging at SHARAQ
Y. Kiyokawa et al.

60

Quadrupole collectivity in island-of-inversion nuclei
S. Michimasa et al.

28,30

Ne and 34,36Mg

61

Study of nuclear structure in proton-rich carbon isotopes
T. Miyazaki et al.

62

Triton contamination in the 10C secondary beam produced by RIPS
T. Miyazaki et al.

63

β-NMR measurement of 41S
Y. Ichikawa, Y. Ohtomo et al.

64

β-NMR measurement in coincidence with β-delayed γ rays of 41S
Y. Ichikawa et al.

65

Interaction of 8B, unstable and loosely bound, with 208Pb: scattering and breakup
C. Signorini, M. Mazzocco et al.

66

First production of 10Be beam at CRIB and 10Be+α resonant elastic scattering
H. Yamaguchi et al.

67

Investigation of the waiting point 22Mg in the rp-process
N.N. Duy et al

68

Production of Lv isotope in the hot fusion reaction of 248Cm+48Ca at E*=38.4 MeV
D. Kaji et al.

69

Production of 215U and 216U and attempt to produce 219Np and 220Pu
Y. Wakabayashi et al.

70

Search for new isotopes in the region around Z = 33 using the in-flight fission of a 238U beam at 345 MeV/nucleon
Y. Shimizu et al.

71

Search for new neutron-rich isotopes with Z ~ 55-70 using a 345 MeV/nucleon 238U beam
N. Fukuda et al.

72

Study of particle identification and RI beam separation for the Z~80 region using projectile fragmentation of 238U
N. Inabe et al.

73

Production cross section measurements of radioactive isotopes produced from a 124Xe beam at 345 MeV/u by the BigRIPS separator
H. Suzuki et al.

74

Production cross section measurements for fragments of 70Zn beam
D.S. Ahn et al.

75

On-line test of rotating magnetic field system for β-NMR method
Y. Ishibashi et al.

76

Probing the critical behavior in the evolution of GDR width at very low temperatures in A ~ 100 mass region
B. Dey et al.

77

2. Nuclear Physics (Theory)
Hoyle band and αcondensation in 12C
Y. Funaki

79

Energy and mass-number dependence of hadron-nucleus total reaction cross sections
A. Kohama et al.

80

Systematic calculation of T = 1 triplets with proton–neutron mixed energy density functionals
K. Sato et al.

81

Correlated two-neutron emission in decay of unbound nucleus 26O
K. Hagino and H. Sagawa

82

Three-body model calculation of the 2+ state in 26O
K. Hagino and H. Sagawa

83

Proton-neutron pairing vibrations in 40Ca: Precursory soft mode of the isoscalar spin-triplet pairing condensation
K. Yoshida84

Study of low-frequency negative-parity vibrational excitations of superdeformed rotational band in 40Ca using cranked Skyrme-RPA
calculations
M. Yamagami and K. Matsuyanagi

85

RIKEN Accel. Prog. Rep. 48 (2015)

CONTENTS

Self-consistent Hartree-Fock and RPA Green's function method for monopole response of neutron-rich Ni isotopes
I. Hamamoto and H. Sagawa

86

Origin of fusion hindrance in heavy systems
K. Washiyama

87

Pairing effect in thermal shape fluctuation model on the width of giant dipole resonance
A.K. Rhine Kumar et al.

88

Shell-model study of Gamow-Teller transition from 100Sn
M. Honma et al.

89

Reentrance phenomenon of superfluid pairing in hot rotating nuclei
N. Quang Hung et al.

90

Giant dipole resonance in highly excited nuclei
N. Dinh Dang

91

Theoretical analysis of 132Xe by generator coordinate method
N. Yoshinaga et al.

92

Tops-on-top model applied to TSD bands in 164Lu
K. Sugawara-Tanabe et al.

93

Recent progress and open issues on pseudospin and spin symmetries
H. Z. Liang et al.

94

Nuclear moment of inertia in super-normal phase transition region
K. Tanabe et al.

95

Joint project for large-scale nuclear structure calculations in 2014
N. Shimizu et al.

96

3. Nuclear Data
Development of a new EXFOR editor system
A. Sarsembayeva et al.

97

Thick-target yields derived from inverse kinematics toward transmutation
S. Imai et al.

98Compilation of nuclear reaction data from the RIBF
D. Ichinkhorloo et al.

99

4. Hadron Physics
Performance improvement of PHENIX MUID
S. Han et al.

101

PHENIX Run13 Local Polarimetry
M. Kim et al.

102

Hadronic backgrounds pattern study for W ±→ μ ± analysis in PHENIX
C. Kim et al.

103

W → μ parity violating asymmetries from the 2013 running period in the PHENIX experiment
R. Seidl

104

Neutral pion double helicity asymmetry
K. Boyle

105

Preliminary results of A Lπ L measurement at √s = 510 GeV at mid-rapidity through a PHENIX experiment
I. Yoon106

Cross section and asymmetry measurement of very forward neutral particle production at RHIC
Y. Goto107

Fragmentation function measurements in BelleR. Seidl et al.

108

Measurement of direct photon azimuthal anisotropy in s NN =200GeV Au+Au collisions in RHIC-PHENIX experiment
S. Mizuno for the PHENIX

109

0Charged hadron ellipptic and triangular flow in Cu+Au at
H. Nakagomi et al.

s NN = 200GeV

110

Commissioning and operation of silicon vertex detector for PHENIX experiment in RHIC Run-14
M. Kurosawa

111

Alignment of the PHENIX Silicon Vertex Tracker (VTX) in the 2014 RUN
T. Moon et al.

112

Distance of closest approach analysis with VTX at RHIC-PHENIX
H. Asano et al.

113

Current status of bottom and charm measurements using VTX at RHIC-PHENIX
T. Hachiya et al.

114

CONTENTS

RIKEN Accel. Prog. Rep. 48 (2015)

Development of the FVTX high multiplicity trigger system for the PHENIX experiment
T. Nagashima et al.

115

Study of direct photon polarization to shed on strong magnetic field in heavy ion collisions at PHENIX
T. Hoshino

116

Measurement of dielectron production in
S. Hayashi et al.

117

s NN = 5.02 TeV p-Pb collisions by using the ALICE detector

Measurement of neutral pion v2 in Pb-Pb collisions at
T. Tsuji et al.

s NN = 2.76 TeV by the ALICE experiment118

s NN =5.02 TeV with the ALICE detector

119

Azimuthal distributions of jets with respect to high-pT neutral pion triggers in pp collisions at √s = 7 TeV and PbPb collisions at s NN
= 2.76 TeV from ALICE
D. Watanabe

120

Long-range correlation in p-Pb collisions at
Y. Sekiguchi et al.

Study of ion backflow with 2GEMs + MICROMEGAS for the ALICE-TPC upgrade
K. Terasaki et al.

121

Search for dark photons from neutral meson decays in p + p and d + Au collisions at
Y. Akiba and Y. Yamaguchi

122s NN = 200 GeV

Progress in probing flavor asymmetry of antiquarks in protons in the E906/SeaQuest experiment at Fermilab
K. Nagai et al.

123

Results of the K − pp bound-state search in J-PARC E151st
T. Hashimoto et al.

124

Measurement of the proton Zemach radius from the hyperfine splitting energy in ground-state muonic hydrogen
M. Sato et al.

125

5. Hadron Physics (Theory)
Strong enhancement of jet-medium coupling in the quark-gluon plasma near transition temperature
J. Liao

Magnetic moments of light nuclei from lattice QCD
S. Beane et al.

127
128

Nucleon structure in lattice QCD near physical mass
S. Ohta

129

Holographic heavy-quark symmetry
K. Hashimoto et al.

130

Possibility of ferromagnetic neutron matter
K. Hashimoto

131

Pion and Kaon form factors in the NJL model
Y. Ninomiya et al.

132

Chiral Magnetic and Vortical Effects at Weak Coupling
H.-U. Yee

133

Collinear parton splitting for early thermalization and chemical equilibration in heavy-ion collisions
A. Monnai and B. Mueller

134

Chemical equilibration of QCD medium for photon v2 puzzle
A. Monnai

135

Refraction of light in the quark-gluon plasma
A. Monnai

136

Transverse single-spin asymmetries in proton-proton collisions and the role of twist-3 fragmentation
D. Pitonyak et al.

137

Left-right spin asymmetries in lepton-nucleon collisions
D. Pitonyak et al.

138

Twist-3 double-spin asymmetries in lepton-nucleon collisions
D. Pitonyak et al.

139

Strong binding and shrinkage of single and double K̄ nuclear systems (K ¯pp, K ¯ppn, K ¯K ¯p and K ¯K ¯pp) predicted by
Faddeev-Yakubovsky calculations
T. Yamazaki et al.

140

New way to produce dense double-antikaonic dibaryon system, K ¯K ¯pp, through Λ(1405) - doorway sticking in p +p collisions
T. Yamazaki et al.

141

Theoretical analysis of Λ(1405) → (Σπ)0 mass spectra produced in p + p → p + Λ(1405) + K+ reactions
M. Hassanvand, S.Z. Kalantari

142

RIKEN Accel. Prog. Rep. 48 (2015)

CONTENTS

6. Particle Physics
h0 → cc̄ as a test case for quark flavor violation in the MSSM
A. Bartl et al.

143

Update on lattice QCD calculation of neutral B meson mixing in static limit of b quark
T. Ishikawa et al.

144

Progress toward an ab initio, Standard Model calculation of direct CP-violation in K-decays
C. Kelly

145

Collisional Energy Loss in Semi-Quark Gluon Plasma
S. Lin et al.

146

Entropic destruction of heavy quarkonium in non-Abelian plasma from the holographic correspondence
K. Hashimoto and D. Kharzeev

147

Magnetic instability in AdS/CFT : Schwinger effect and Euler-Heisenberg Lagrangian of Supersymmetric QCD
K. Hashimoto, T. Oka et al.

148

Turbulent meson condensation in quark deconfinement
K. Hashimoto et al.

149

Meson turbulence at quark deconfinement from AdS/CFT
K. Hashimoto et al.

150

Electromagnetic instability in holographic QCD
K. Hashimoto et al.

151

Electric Field Quench in AdS/CFT
K. Hashimoto et al.

152

Holographic entanglement and causal shadow in the time-dependent Janus black hole
Y. Nakaguchi, N. Ogawa, T. Ugajin

153

Radion stabilization in the presence of Wilson line phase
Y. Abe et al.

154

Is cosmological constant screened in Liouville gravity with matter?
T. Inami et al.

155

Effective Higgs interactions of composite dark matter
E. T. Neil

156

Effective field theory for spacetime symmetry breaking
Y. Hidaka, T. Noumi, G. Shiu

157

Dynamical breaking of shift-symmetry in supergravity-based inflation
A. Mazumdar, T. Noumi et al.

158

Non-Gaussianities of primordial perturbations and tensor sound speed
T. Noumi and M. Yamaguchi

159

Spin operator and entanglement in quantum field theory
K. Fujikawa et al.

160

Linearity of quantum probability measure and Hardy's model
K. Fujikawa et al.

161

SSD and the infinite circumference limit of CFT
T. Tada162

Towards U(N|M) knot invariant from ABJM theory
B. Eynard and T. Kimura

163

Duality and integrability of supermatrix model with external source
T. Kimura

164

Bulk angular momentum and Hall viscosity in chiral superconductors
A. Shitade and T. Kimura

165

7. Astrophysics and Astro-Glaciology
Insights from Antarctica on volcanic forcing during the Common Era
M. Sigl et al.

167

Variation in chemical composition induced by solar energetic particle events in the middle atmosphere
Y. Nakai et al.

168

Measurements of nitrogen isotope ratios in samples with very low nitrate concentrations from the Dome Fuji ice core (Antarctica) drilledin 2010
Y. Motizuki et al.

169

X-ray and Optical/UV Correlation Studies of Active Galactic Nuclei
H. Noda170

Time-variable Fe K emission lines from accreting white dwarf binaries
T. Yuasa

171

CONTENTS

RIKEN Accel. Prog. Rep. 48 (2015)

Spectral and Temporal Approach to Physics of Neutron Stars
T. Enoto, T. Tamagawa et al.

172

Timing analysis of solar flares in hard X-ray and soft γ-ray bands measured by the Suzaku Wide-band All-sky Monitor
W. Iwakiri et al.

173

Spurious shear from tree-rings on LSST CCD
Y. Okura et al.

174

Performance test of TPC Polarimeter for cosmic X-ray sources at BNL NSLS-1
W. Iwakiri et al.

175

Fabrication of a TPC X-ray Polarimeter and Preliminary Testing with the Synchrotron Radiation Light Source at Spring-8
A. Hayato et al.

176

Measurement of X-ray beam polarization of BL32B2 at SPring-8 using a Compton polarimeter
M. Kubota et al.

177

Performance test of Modulated X-ray Source using UV-LED and Channel Electron MultiplierW. Iwakiri et al.

178

Property of LCP-GEM in pure dimethyl ether at low pressures
Y. Takeuchi et al.

179

Measurement of the electron drift velocity in DME gas
M. Kubota et al.

180

Measures for Micro Meteoroids and Orbital Debris in Cooler Driver Harnesses of the Soft X-ray Spectrometer onboard ASTRO-H
H. Noda et al.

181

8. Accelerator
Emittance measurements for RIKEN 28 GHZ SC-ECRIS
Y. Higurashi et al.

183

Supply of 70Zn beam from 18-GHz ECRIS using the micro-oven
K. Ozeki et al.

184

Current status of the RIKEN 18-GHz superconducting ECR ion source
T. Nagatomo et al.

185

Acceleration test of 235U
K. Ozeki et al.

186

Modification of septum electrode for RRC-EDC
K. Yamada et al.

187

Construction of new amplifiers for RILAC
K. Suda et al.

188

Magnet system for a new beam transport line from IRC to E5 experimental room
K. Kumagai et al.

189

Improved-flatness beryllium disk stripper for uranium acceleration at RIKEN RIBF
H. Hasebe et al.

190

Thinning effect of gas strippers for high-intensity very heavy ion beams
H. Imao et al.

191

Control and monitoring system of gas strippers
R. Koyama and H. Imao

192

Beam Energy and Longitudinal Beam Profile Measurement System at the RIBF
T. Watanabe et al.

193

Maintenance and development of the RIBF control system
M. Komiyama et al.

194

Development of new operational log system for RIBF operation
A. Uchiyama et al.

195

Commissioning of the Laser Ion Source for RHIC EBIS
M. Okamura and T. Kanesue

196

NISHINA RIBF water-cooling system 2014
T. Maie et al.

197

Charge State Selective Ion Beam Acceleration Using the RFQ Linac
Y. Fuwa et al.

198

Investigation of the effect of solenoidal magnetic field on Fe plasma flux for application to laser ion source
S. Ikeda et al.

199

9. Instrumentation
Operational status of the superconducting SAMURAI magnet
H. Sato et al.

201

RIKEN Accel. Prog. Rep. 48 (2015)

CONTENTS

Preparation status of the (p, 2p) fission experiment with the SAMURAI spectrometer
S. Reichert and M. Sako et al.

202

Slow neutron detector WINDS for (p, n) reaction in inverse kinematics with SAMURAIJ. Yasuda et al.

203

Integration of GET system for SπRIT-TPC
T. Isobe et al.

204

Performance evaluation of GET readout electronics for heavy ion collision experiments at RIBF
G. Jhang, T. Isobe et al.

205

Status of SπRIT-TPC
M. Kurata-Nishimura et al.

206

Test of prototype crystals of the γ-ray detector CATANA
Y. Togano et al.

207

Isotope separation with new ion-optics mode
H. Takeda et al.

208

A NaI (Tl) detector array for measurements of γ rays from fast radioactive isotope beams
S. Takeuchi et al.

209

Development of a total-kinetic-energy counter for high-rate experiments at ZeroDegree spectrometer
R. Taniuchi et al.

210

Low-pressure MWDC system for ESPRI experimentY. Matsuda et al.

211

NiGIRI: Identification of n, p, d, t, 3,4He, 6,7Li, and γ-rays
H. Matsuzawa et al.

212

Proposal of novel delayed-neutron branching ratio measurements using MRTOF
M. Wada213

Advanced development of GARIS-Ⅱ using He-H2 mixture as a filled gas toward the study of superheavy element
D. Kaji et al.

214

Pulse shape analysis for short-lived decay of superheavy elements
S. Yamaki et al.

215

Performance of ion surfing rf-carpet for high-energy RI beam gas catcher
F. Arai et al.

216

Evaluation of effects of a large energy deposition on Deuterium gaseous active target for a high-intensity ion beam injection
C.S. Lee, S. Ota et al.

217

Design of a thin-film polarized proton target system for low-energy RI beam experiments
E. Milman et al.

218

Kinetic parameters of photo-excited triplet state of pentacene determined by dynamic nuclear polarization
K. Tateishi et al.

219

Development of single-crystal CVD diamond detector for time-of-flight measurements
Y. Sato et al.

220

Efficient excitation of photo-excited triplet electrons of pentacene for dynamic nuclear polarization
K. Tateishi et al.

221

Realization of 1H spin polarization of 40% at room temperature
K. Tateishi et al.

222

Production of spin polarization of atoms in superfluid helium using a pulsed Ti: sapphire laser
M. Hayasaka et al.

223

Microwave system development of enlarged spin-polarized proton target for RI beam experiments
S. Chebotaryov et al.

224

The off-line adjustment of the parasitic production of low-energy RI-beam system for installation in BigRIPS
T. Sonoda et al.

225

Current status of the gas cell ion beam cooler-buncher at SLOWRI
Y. Ito et al.

226

SCRIT luminosity monitor
S. Yoneyama et al.

227

Study of the performance of the SCRIT rear drift chamber
S. Matsuo et al.

228

Current status of RI beam production at electron-beam-driven RI separator for SCRIT (ERIS)
T. Ohnishi et al.

229

Development of the readout system for SCRIT WiSES
A. Enokizono et al.

230

New fast-kicker system for Rare RI Ring
Y. Yamaguchi et al.

231

CONTENTS

RIKEN Accel. Prog. Rep. 48 (2015)

Status of the resonant Schottky pick-up for the Rare RI Ring project
F. Suzaki et al.

232

Extraction of multi-nucleon transfer reaction products in 136Xe and 198Pt systems
Y. Hirayama et al.

233

Detector system for the KEK isotope separation system
S. Kimura et al.

234

Q-value resolution improvements in the spectroscopy of deeply bound pionic atoms using BigRIPS
T. Nishi et al.

235

Development of D2 gas-filled drift chamber for spectroscopy measurements of pionic atoms in inverse kinematics
Y.N. Watanabe et al.

236

Radiation monitoring in the RIBF using ionization chamber
M. Nakamura et al.

237

Measurement of activation around the He gas stripper at RIBF
A. Akashio et al.

238

Beam preparation for fee-based utilization of a 70-MeV/A Kr-beam
A. Yoshida and T. Kambara

239

Implantation of 7Be and 22Na beams for wear diagnostics application
A. Yoshida et al.

240

Development of a GEM tracker for the J-PARC E16 experiment
W. Nakai

241

Preparation status of the J-PARC E16 experiment: measurement of spectral change of vector mesons in nuclei
S. Yokkaichi et al.

242

Simulation of HBD response in the J-PARC E16 experiment based on test results
K. Kanno et al.

243

Resistive Plate Chamber (RPC) for BGOegg Experiment
T. Nam, N. Tomida

244

Quality assurance test of pixel detector ladders for VTX
T. Sumita et al.

245

Fast clear technique for NEBULA data acquisition for SAMURAI17 experiment
Y. Togano et al.

246

Test of the advanced implantation detector array (AIDA) at RIBF
C. Griffin et al.

247

CCJ operations in 2014
S. Yokkaichi et al.

248

Computing and network environment at the RIKEN Nishina Center
T. Ichihara, Y. Watanabe, H. Baba

249

Ⅲ. RESEARCH ACTIVITIES II (Material Science and Biology)
1. Atomic and Solid State Physics (Ion)
Hyperfine structure measurement of 133Cs atoms in superfluid helium
K. Imamura et al.

251

Lattice location and density distribution of hydrogen in β1-V2H
E. Yagi et al.

252

Observation of the FFLO-like nodal planes in the Au layer of Nb/Au/Fe trilayers by neutron reflectivity measurements
H. Yamazaki et al.

253

Response of polyimide films to U ion beams as etched-track detectors
T. Yamauchi et al.

254

High-density n-type doping of diamond by nitrogen beam implantation
H. Ueno et al.

255

2. Atomic and Solid State Physics (Muon)
μSR study of the magnetism and superconductivity in the multi-layered Bi-2223 high-Tc superconductor
T. Adachi et al.

257

μSR study of the Al-induced magnetic order in La2 − x SrxCu1 − y AlyO4
K. M. Suzuki et al.

258

μSR study of cluster-glass state in Sr1 − x LaxRuO3
I. Kawasaki et al.

259

Investigation of magnetic ground states in mixed kagome systems (Rb1 − x Csx)2Cu3SnF12 by μSR
T. Suzuki et al.

260

High pressure μSR study of quantum phase transition in CeNiAsO
H. Guo et al.

261

RIKEN Accel. Prog. Rep. 48 (2015)

CONTENTS

Investigation of hydrogen dynamics in hydroxyl salts Co2(OD)3Cl
X.G. Zheng et al.

262

Partial magnetic order in the quantum spin system NH4CuCl3
T. Goto et al.

263

Zn-substitution effects on distorted tetrahedral spin-chain system Cu3Mo2O9
H. Kuroe et al.

264

Magnetic ground state of Cu6O8MCl (M = Y, Pb) with a caged structure
K. Kawashima et al.

265

μSR studies on antiferromagnet RRu2Al10 (R = Sm, Gd)
H. Tanida, H. Guo et al.

266

Determination of muon sites on metal-organic hybrids of (C6H5CH2CH2NH3)2CuCl4 and (C2H5NH3)2CuCl4
E. Suprayoga et al.

267

Investigation of muon sites in YBa2Cu3O6 using density functional theory
S.S. Mohd-Tajudin

268

Muon sites in Ce(Ru, Rh)2Al10 investigated using Density Functional Theory from the perspective of electronic potential
N. Adam et al.

269

μSR study of the density wave state in α-(BEDT-TTF)2MHg(SCN)4 (M=K, Rb)
K. Ichimura et al.

270

Study on coupling between electron conduction and spin fluctuation in novel organic charge transfer complexes with TANC
M. Enomoto et al.

271

Study of charge carrier transport in active layer P3HT:ZnO:PCBM hybrid solar cells measured by muon spin relaxation
L. Safriani et al.

272

μSR study on antiferromagnetism in K-Rb alloy and Rb clusters in sodalite
T. Nakano et al.

273

Li-ion diffusion in LixFePO4 with x = 0, 0.25 and 0.5
I. Umegaki et al.

274

Investigations of defects in TiO2 rutile crystal by muon and muonium
K. Asakura, H. Ariga et al.

275

Response of muonium to oxygen contents in hemoglobin and other biological aqueous solutions for cancer research
K. Nagamine

276

Development of gas system for MuSEUM experiment
K. S. Tanaka et al.

277

Development of online muon beam profile monitor for the MuSEUM experiment
S. Kanda278

3. Radiochemistry and Nuclear Chemistry
Reversed-phase extraction behavior of the 105th element, Db, with tributyl phosphate
M. Murakami et al.

279

Solid-liquid extraction of 261Rf from hydrochloric acid with Aliquat 336 resin
T. Yokokita et al.

280

Extraction behavior of rutherfordium as a cationic fluoride complex with a 2-thenoyltrifluoroacetone chelate extractant from HF/HNO3
acidic solutions
Y. Kitayama et al.

281

Thermal stability of the group 6 hexacarbonyl complexes
I. Usoltsev et al.

282

Extraction behavior of Mo and W from H2SO4 using amine-extractant (Aliquat336) as homologs of seaborgium
A. Toyoshima et al.

283

Solvent extraction of short-lived radioisotopes of Mo and W from oxalic acid solution with Aliquat 336 for chemical studies of seaborgium (Sg)N. Goto et al.

284

Reversed-phase chromatography of Nb and Ta with TBP for conducting a chemical experiment on the 105th element, Db
M. Murakami et al.

285

Liquid-liquid extraction of Nb and Ta with Aliquat 336 from 0.27 M HF solution
D. Sato et al.

286

Coprecipitation Behaviors of Zr, Hf, and Th with Sm Hydroxide for Chemical Study of Element 104, Rf
Y. Kasamatsu, et al.

287

Liquid-liquid extraction of zirconium and hafnium with 2-thenoyltrifluoroacetone for chemical studies of element 104, rutherfordium
A. Tanaka et al.

288

Production of platinum radiotracer for Gamma-Ray Emission Imaging
S. Komoto et al.

289

Production of 88Y for gamma-ray emission imaging
K. Higashikawa et al290

CONTENTS

RIKEN Accel. Prog. Rep. 48 (2015)

99

Ru Mössbauer spectroscopy of Na-ion batteries of Na2RuO3 (I)Y. Kobayashi et al.

291

Production of 262, 263Db in the 248Cm(19F,xn)267-xDb reactions at Elab = 96 MeV
M. Murakami et al.

292

Production of 174Re in the natGd(23Na,xn) reactions for future studies on Bh chemistry using GARIS
H. Haba et al.

293

Excitation function of the natHf(α,x)182gTa reaction: Cyclotron production of a long-lived γ-ray emitter 182gTa
M. Murakami et al.

294

Production cross sections of (d,x) reactions on natural ytterbium
M. U. Khandaker and H. Haba

295

Measurement of production cross sections of Tc isotopes in the natMo(d,x) reactions
Y. Komori et al.

296

Measurements of alpha-induced cross section for 48Cr and 49Cr up to 50 MeV
H. Kikunaga et al.

297

Improvement in the chemical yield of purified 109Cd for fee-based distribution at the RIKEN AVF cyclotron
Y. Wakitani et al.

298

Preparation of no-carrier-added 85Sr using the natRb(d,x)85Sr reaction
S. Yano et al.

299

4. Radiation Chemistry and Biology
Localization of Rad51 and phosphorylated DNA-PKsc after heavy-ion irradiation in mammalian cells
M. Izumi et al.

301

Low-dose high-LET heavy ion-induced bystander signaling
M. Tomita et al.

302

Effect of days after irradiation on lethal rate of F3 progeny in the fruit fly mutation isolation system
K. Tsuneizumi and T. Abe

303

Extra-early-flowering wheat mutants produced by heavy-ion-beam mutagenesis
A. Nishiura et al.

304

Heredity analysis of radiation induced semidwarf mutants in Tartary buckwheat (Fagopyrum tataricum Gaertn.)
T. Morishita et al305

Effects of Ar-ion beam irradiation on inducing mutations in chrysanthemum and sweetpotato
Y. Tanokashira et al.

306

Rapid screening of heavy-ion-induced large deletion mutants by using quantitative real-time PCR in Arabidopsis thaliana
Y. Kazama et al.

307

LET-dependent effect on mutation induction DNA repair-deficient background in Arabidopsis thaliana
K. Ishii et al.

308

Characterization of isolates derived from heavy-ion-beam irradiated cells in the unicellular green alga Parachlorella kessleri
T. Yamazaki et al.

309

Effects of Ar-ion beam irradiation on survival rate of Aurantiochytrium sp.
K. Ikeda et al.

310

Analysis of DNA breakpoint detected from rice exome sequencing data
R. Morita et al.

311

Establishment of rice transformation systems to study gene functions
R. Morita et al.

312

Functional analysis of a new virescent mutant in rice induced by heavy-ion beam irradiation
H. Abe et al.

313

Tracking alleles linked with Fusarium head blight resistance QTLs in wheat (Triticum aestivum) released in Kyushu region
S. Niwa et al.

314

Ion track observation in cell nucleus irradiated by 3 MeV He ion microbeams produced with glass capillaries
T. Ikeda et al.

315

Estimation method of microbeam divergence from glass capillaries for biological use
R.J. Bereczky et al.

316

Fricke nanocomposite gel dosimeter for heavy ion beam irradiation
T. Maeyama et al.

317

Ⅳ. OPERATION RECORDS
Program Advisory Committee meetings for nuclear physics and for material and life science
K. Yoneda et al.

319

Beam-time statistics of RIBF experiments
K. Yoneda et al.

320

RIKEN Accel. Prog. Rep. 48 (2015)

CONTENTS

Operation report of the industrial cooperation teamA. Yoshida et al.

321

Electric power condition of Wako campus in 2014
E. Ikezawa et al.

322

Radiation safety management at RIBF
K. Tanaka et al.

323

RILAC operation
E. Ikezawa et al.

326

AVF operations in 2014
N. Tsukiori et al.

327

Present status of the liquid-helium supply and recovery system
T. Dantsuka et al.

328

Operation of the superconducting ring cyclotron cryogenic system
H. Okuno et al.

329

Present status of the BigRIPS cryogenic plant
K. Kusaka et al.

330

Operation report on the ring-cyclotrons in the RIBF accelerator complex
S. Fukuzawa et al.

331

Ⅴ. EVENTS

333

Ⅵ. ORGANIZATION AND ACTIVITIES OF RIKEN NISHINA CENTER (Activities and Members)

337

Organization

337

Finances

338

Staffing

339

Research publication

339

Management

340

International Collaboration

345

Awards347

Brief overview of the RI Beam Factory

347

Theoretical Research Division

Quantum Hadron Physics Laboratory

350

Theoretical Nuclear Physics Laboratory

353

Strangeness Nuclear Physics Laboratory

356

Mathematical Physics Laboratory

358

Sub Nuclear System Research Division
Radiation Laboratory

361

Advanced Meson Science Laboratory

365

RIKEN-BNL Research Center

370

Theory Group371

Computing Group

373

Experimental Group375

RIKEN Facility Office at RAL

379

RIBF Research Division
Radioactive Isotope Physics Laboratory

382

Spin isospin Laboratory

386

Nuclear Spectroscopy Laboratory

389

High Energy Astrophysics Laboratory

391

Astro-Glaciology Research Unit

393

Research Group for Superheavy Element

394

Superheavy Element Production Team

396

Superheavy Element Research Device Development Team

397

Nuclear Transmutation Data Research Group
Fast RI Data Team

398
399

CONTENTS

RIKEN Accel. Prog. Rep. 48 (2015)
Slow RI Data Team400

Muon Data Team401

High-Intensity Accelerator R&D Group402

High-Gradient Cavity R&D Team403

High-Power Target R&D Team404

Accelerator Group405

Accelerator R&D Team406

Ion Source Team407

RILAC Team

408

Cyclotron Team409

Beam Dynamics & Diagnostics Team410

Cryogenic Technology Team

411

Infrastructure Management Team

412

Instrumentation Development Group413

SLOWRI Team

414

Rare RI-ring Team

417

SCRIT Team

419

Research Instruments Group

421

BigRIPS Team422

SAMURAI Team

424

Computing and Network Team

425

Detector Team

427

Accelerator Applications Research Group

428

Ion Beam Breeding Team429

RI Applications Team

431

User Liaison and Industrial Cooperation Group

433

User Support Office434

Industrial Cooperation Team

435

Safety Management Group
Partner Institution

436
437

Center for Nuclear Study (CNS), The University of Tokyo

438

Center for Radioactive Ion Beam Sciences, Niigata University

441

Radioactive Nuclear Beam Group, Institute for Particle and Nuclear Studies, KEK

443

Events (April 2014 - March 2015)

445

Press Releases (April 2014 - March 2015)

446

Ⅶ. LIST OF PUBLICATIONS & PRESENTATIONS

447

Ⅷ. LIST OF PREPRINTS

531

Ⅸ. LIST OF SYMPOSIA & WORKSHOPS

535

Ⅹ. LIST OF SEMINARS

537

AUTHOR INDEX

547

I. HIGHLIGHTS OF THE YEAR<< Selection process of highlights >>Highlights are selected by a two-step process. In the first step, a referee who reviews a manuscript decides
whether she/he would recommend it as one of the highlights.
Members of the editorial board then make additional recommendations if they think an important contribution
has not been recommended by the referee.
The second step involves the editor-in-chief proposing a list of highlights based on the recommendation given
above to the editorial board. After discussing the scientific merits and uniqueness of the manuscripts fromviewpoints of experts/non-experts, the editorial board makes the final decision.

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

1p3/2 Proton-Hole State in 132 Sn and Shell Structure Along N=82†
J. Taprogge,∗1,∗2,∗3 A. Jungclaus,∗1 H. Grawe,∗4 S. Nishimura,∗2 P. Doornenbal,∗2 G. Lorusso,∗2
G.S. Simpson,∗5 P.-A. Söderström,∗2 T. Sumikama,∗6 Z.Y. Xu,∗7 H. Sakurai,∗2,∗7 H.Watanabe,∗2 on behalf of
the RIBF-85 and RIBF-60&62R1 collaborations
The nucleus 132 Sn is of particular interest for nuclear structure investigations since it is the only heavy
neutron-rich doubly-magic nucleus far away from thevalley of stability which is accessible for experimental studies. While 132 Sn as well as the neighboring
Sn (Z=50) and Sb (Z=51) isotopes have been studied in detail in the past, the experimental information
for nuclei in the region below 132 Sn is scarce. Important knowledge, e.g. with respect to the energies of the
proton single-hole states in 132 Sn, is still missing.
In an experiment performed in December 2012 aspart of the EURICA campaign at the RadioactiveIsotope Beam Factory (RIBF), the neutron-rich nuclei 131,132 Cd were produced by the in-ﬂight ﬁssion ofa 238 U beam and implanted into the active stopper
WAS3ABi. The γ rays emitted following the β decay of 131 Cd and after β-delayed neutron emission of132
Cd were detected with the EURICA array comprising 84 germanium crystals. A single γ ray with anenergy of 988 keV was observed in the decays of both131
Cd and 132 Cd. It was placed to populate the known(1/2− ) β-decaying isomer in 131 In at an excitation energy of Ex = 365(8) keV thus deﬁning a second excitedstate at 1353 keV. This newly identiﬁed state is preliminary assigned to have spin and parity of 3/2− andto correspond to the previously unknown 1p3/2 proton
single-hole state with respect to the 132 Sn core. A fullaccount of the arguments which lead to this assignmentis presented in Ref. 2) .
Using the newly established 1p3/2 proton singlehole energy, shell-model calculations have been performed to calculate the energies of the ﬁrst excited
2+ states and the proton gaps ∆2p [deﬁned here as∆2p = M (Z + 2, N ) + M (Z − 2, N ) − 2M (Z, N ), with
M (Z, N ) the mass of a nucleus with Z protons andN neutrons] for the N =82 isotones below 132 Sn as
shown in Fig. 1. For comparison, Fig. 1 also shows theresults of similar SM calculations performed for the
N =50 isotones below 100 Sn, in that case in comparison with available experimental information. Whilefor the N =50 isotonic chain typical signatures of subshell closures are observed at Z=38 and 403,4) , they
†
∗1
∗2
∗3
∗4
∗5
∗6
∗7

N = 50N = 82c)E(2+) [MeV]a)2
1+0.5 MeV+1.0 MeV+1.5 MeV

experimental data
shell-model this work
shell-model Ref. 3)
30

34

38

42

46

34

38

42

46 50
d)

30

34

38

42

46 50 30 34
Proton number Z

38

42

46

30

∆2p [MeV]

4

50
b)

3
2
1
50

Fig. 1. a) and c): Energies of the ﬁrst excited 2+ states,
E(2+ ), and b) and d): proton gaps, ∆2p , in the even
N =50 and N =82 isotones, respectively. The black lines(solid, dashed, and dotted) in c) and d) show the resultsof SM calculations assuming an increase of the 1p splitting by 0.5, 1.0, and 1.5 MeV, respectively.

disappear for the N =82 isotones below 132 Sn. The
disappearance of the proton sub-shell closures has its
origin in the small energy gap between the 1p1/2 andthe next single-particle orbital (SPO), independent of
the character of the latter. Figs. 1 c) and d) show
the reappearance of the sub-shell gap when increasing
the energy separation between the 1p1/2 orbit and thenext SPO.
Without the existence of pronounced proton subshell closures the N =82 isotones 120 Sr and 122 Zr should
behave as mid-shell nuclei and consequently enhanced
cross-shell excitations are expected to lead to a reduction of the N =82 shell gap in that region. Such a
reduction would have a signiﬁcant impact on r-process
calculations and it is therefore concluded that preference should be given to mass models which indeed predict a reduction of the N =82 gap, such as the HFB245)
approach.
References
1) J. Dobaczewski et. al., Phys. Rev. Lett. 72, 981 (1994).
2) J. Taprogge et. al., Phys. Rev. Lett. 112, 132501 (2014).
3) A. F. Lisetskiy et. al., Phys. Rev. C 70, 044314 (2004).
4) T. Fastermann et. al. Prog. Part. Nucl. Phys. 69, 85(2013).
5) S. Goriely et. al., Phys. Rev. C 88, 024308 (2013).

Condensed from the article in Phys. Rev. Lett., Vol. 112,132501 (2014)
Instituto de Estructura de la Materia, CSICRIKEN Nishina Center
Departamento de Fı́sica Teórica, Uni. Autónoma de Madrid
GSI Helmholtzzentrum für Schwerionenforschung GmbH
LPSC, UJF, CNRS, INPG, Grenoble
Department of Physics, Tohoku University
Department of Physics, University of Tokyo-1-

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Isomer decay spectroscopy of 164 Sm and 166 Gd: mid-shell collectivity
around N=100†
Z. Patel,∗1,∗2 P.-A. Söderström,∗1 Zs. Podolyák,∗2 P. H. Regan,∗2,∗3 P. M. Walker∗2 H. Watanabe∗1,∗4
E. Ideguchi∗5 G. S. Simpson∗6 H. L. Liu∗7 S. Nishimura,∗1 Q. Wu,∗8 F. R. Xu,∗8 H. Sakurai,∗1
The RIBF-86 Collaboration and the EURICA Collaboration
t1/2 = 600(140) ns

The deformation of nuclei around A = 160 may
influence the elemental abundances in the rare earth
element peak. Macroscopic-microscopic calculations
show a deformation maximum close to N = 104 andZ = 66 (170 Dy)1) . However, these calculations seem tobe contradicted by recent experimental data2,3) . We
utilise the existence of K isomers in this deformed region, to reveal the low-lying excited states in A ≈ 160
nuclei that can provide insight into their deformation.
Neutron-rich Z = 62, 64 isotopes were produced byin-flight fission of a 345 A·MeV 238 U beam with anaverage beam intensity of 10 pnA incident on a 9 Be
target at the RIBF. The secondary RI beam containing the nuclei of interest is passed through BigRIPS
and the ZeroDegree spectrometers that separate andidentify the beam species on an ion by ion basis, using
TOF, Bρ and ∆E. The ions of interest were implanted
in a stopper and the γ rays emitted following isomeric
decay were detected using EURICA (Euroball-RIKEN
Cluster Array): 84 HPGe crystals arranged in a 4π
configuration around the stopper.

(5 )(4 ) 105

(37)

1119

137

(5 )
(4 )
(3 )

(5 )
669
(6 )

energy surface calculations4) with total energy minimised in (β2 , β4 , β6 ) deformation space and γ = 0 sug−+gest a 6− state with a 2-neutron ν 52 [512] ⊗ ν 72 [633]166164
configuration is isomeric in both
Gd andSm.
A key feature of our results are the first 2+ and 4+
energies. The systematics of E(2+ ) and E(4+ → 2+ )are shown in Fig. 3. The observed 2+ and 4+ energiesof 166 Gd and 164 Sm are the lowest in their isotopic
chains and of the N = 102 isotones, suggesting they
are the most deformed N = 102 nuclei observed in thisregion to date. Our new points in the systematics also
highlight the increase of E(2+ ) and E(4+ → 2+ ) at
N = 100. This behaviour supports the appearance ofa recently predicted deformed shell gap at N = 1005)
that will influence r-process abundance calculations.

(6 )

100
78

1009

1280

1170

1088
1249

1188

120

(6 )

(2 )
0

249
100

161
70

Fig. 1. Level scheme of 166 Gd obtained in this work.

∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

90
80

60
92

Sm
Gd
Dy
Er
Yb

240

70

The decay from isomeric states in 166 Gd and 164 Sm(N = 102) has been detected for the first time. The
half-lives of the isomeric states have been measured tobe 950(60) ns and 600(140) ns for 166 Gd and 164 Sm respectively. Their level schemes, seen in Figs. 1 and 2,
were deduced from γ-γ coincidence analysis. Potential
†

260

Sm
Gd
Dy
Er
Yb

110

E(2+) keV

(4 )

156

Fig. 2. Level scheme of 164 Sm obtained in this work.

939
1224

242

(4 )
(2 )
0

183
178

911

E(4+ → 2+) keV

t1/2 = 950(60) ns
146

(6 )

349

220
200
180
160

94

96

98

N

100

102

104

106

140
92

94

96

98

100 102 104 106

N

Fig. 3. Systematics of E(2+ ) and E(4+ → 2+ ) for Sm, Gd,
Dy, Er and Yb isotopes. All data points from ENDSDF
and this work.

References

Condensed from the article in Phys. Rev. Lett. 113, 262502(2014)RIKEN Nishina Center
Department of Physics, University of Surrey
Radioactivity Group, National Physics Laboratory
Department of Physics, Beihang University
RCNP, Osaka University
LPSC, UJF, CHRS, INPG, Grenoble
Department of Applied Physics, Xi’an Jiaotong University
School of Physics, Peking University

1) P. Moller et al., Atomic and Nuclear Data Tables 59,
185 (1995).
2) E. F. Jones et al., Journal of Physics G 30, L43 (2004).
3) P.-A. Söderström et al., Phys. Rev. C 81, 034310 (2010).
4) F. Xu, et al., Phys. Lett. B 435, 257 (1998).
5) S. K. Ghorui, et al., Phys. Rev. C 85, 064327 (2012).

-2-

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

β-Decay half-lives of 76,77Co, 79,80Ni and 81 Cu: experimental
indication of doubly magic 78 Ni†
Z. Y. Xu,∗1,∗2 S. Nishimura,∗2 G. Lorusso,∗2 F. Browne,∗3,∗2 P. Doornenbal,∗2 G. Gey,∗4,∗5,∗2 H.-S. Jung,∗6
Z. Li,∗7 M. Niikura,∗1 P.-A. Söderström,∗2 T. Sumikama,∗8 J. Taprogge,∗9,∗10,∗2 Zs. Vajta,∗11,∗2
H. Watanabe,∗12 J. Wu,∗7,∗2 A. Yagi,∗13 K. Yoshinaga,∗14 H. Baba,∗2 S. Franchoo,∗15 T. Isobe,∗2 P. R. John,∗16
I. Kojouharov,∗17 S. Kubono,∗2 N. Kurz,∗17 I. Matea,∗15 K. Matsui,∗1 D. Mengoni,∗16 P. Morfouace,∗15
D. R. Napoli,∗18 F. Naqvi,∗19 H. Nishibata,∗13 A. Odahara,∗13 E. Şahin,∗20 H. Sakurai,∗1,∗2 H. Schaffner,∗17
D. Sohler,∗11 I. G. Stefan,∗15 D. Suzuki,∗15 R. Taniuchi,∗1 and V. Werner∗19
In order to study the nuclear shell evolution around
Ni, the β-decay half-lives of neutron-rich nuclei, i.e.,
76,77
Co, 79,80 Ni and 81 Cu were measured for the firsttime. The experiment was performed as part of an EURICA campaign at the RIBF facility, RIKEN in 2012.
A high-intensity 238 U beam was accelerated up to anenergy of 345 A MeV by the RIKEN cyclotron accelerator complex before hitting a 3-mm-thick beryllium
target to produce secondary beams via in-flight fission.
The 238 U86+ beam was delivered at an average currentof 5 pnA to the production target position. During the
13 days of the experiment, about 1.2 × 104 78 Ni nuclei
were identified and delivered to the experimental decay
station at the end of the ZeroDegree spectrometer.
Figure 1 shows the experimental results (solid symbols) and the values in the literature (open symbols)
as a function of the neutron number. Due to the fifth
power relation between the half-life and its Qβ value,
a linear relationship between log10 T1/2 and the neutron number of the parent nucleus is expected phenomenologically when Qβ evolves smoothly in an isotopic chain. In Fig. 1 this linearity is clearly visible
below N = 50. Beyond that, a sudden reduction isseen in the Z = 28 isotopic chain due to the shorter
half-lives of 79,80 Ni with reference to the systematics
at N ≤ 50. The fast β-decay processes in 79,80 Ni could
be attributed to the neutrons outside the N = 50 shell,
which result in higher Qβ values and β-decay rates of79,80
Ni compared to that of 78 Ni.
78

Half-life (ms)

103

102
31Ga
30Zn

29Cu

10

28Ni

27Co

44

46
48
Neutron number

50

52

Fig. 1. Experimental half-lives as a function of neutron
number for isotopes with Z = 27 − 31. All the solid
symbols represent the half-lives determined in this work
while the open symbols are the half-lives taken from theliterature1–4) . The systematic trends in the different
isotopic chains are highlighted by lines connecting thedata points with a smaller uncertainty.

In addition, a large gap can be noticed in Fig. 1
between the half-lives of the Co and Ni isotopes fromN = 44 to N = 50. According to shell model calculations, this can be explained by the filled proton f7/2
single particle orbit (SPO) in Ni isotopes. In this case,the proton produced in the β decay of Ni isotopes fills
the πf5/2 SPO above πf7/2 , leading to a reduction of
the Qβ value and longer half-lives of Ni isotopes thanthose of Co isotopes. The newly measured half-lives of76,77
Co follow the decreasing trend with considerable
gaps relative to those of the corresponding Ni isotones,
indicating an almost constant Z = 28 shell gap without significant quenching up to N = 50.

†

Condensed from the article in Phys. Rev. Lett. 113, 032505(2014)∗1 Department of Physics, University of Tokyo∗2 RIKEN Nishina Center∗3 University of Brighton∗4 LPSC, Université Grenoble-Alpes, CNRS/IN2P3∗5 ILL, Grenoble∗6 Department of Physics, University of Notre Dame
∗7 Department of Physics, Peking University∗8 Department of Physics, Tohoku University∗9 Universidad Autónoma de Madrid∗10 Instituto de Estructura de la Materia, CSIC
∗11 Atomki, Debrecen∗12 IRCNPC, Beihang University∗13 Department of Physics, Osaka University∗14 Department of Physics, Tokyo University of Science∗15 Institut de Physique Nucléaire d’Orsay, IN2P3-CNRS∗16 Università di Padova and INFN Sezione di Padova∗17 GSI∗18 Istituto Nazionale di Fisica Nucleare∗19 Wright Nuclear Structure Laboratory, Yale University

References
1) NNDC database (2013), http://www.nndc.bnl.gov/;
2) C. Mazzocchi et al.: Phys. Lett. B 622, 45 (2005);
3) P. Hosmer et al.: Phys. Rev. C 82, 025806 (2010);
4) M. Madurga et al.: Phys. Rev. Lett. 109, 112501(2012);-3-

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Intermediate-energy Coulomb excitation of 104Sn:
Moderate E2 strength decrease approaching 100 Sn†
P. Doornenbal,∗1 S. Takeuchi,∗1 N. Aoi,∗2 M. Matsushita,∗3,∗4 A. Obertelli,∗5 D. Steppenbeck,∗3 H. Wang,∗1,∗6
L. Audirac,∗5 H. Baba,∗1 P. Bednarczyk,∗7 S. Boissinot,∗5 M. Ciemala,∗7 A. Corsi,∗5 T. Furumoto,∗8 T. Isobe,∗1
A. Jungclaus,∗9 V. Lapoux,∗5 J. Lee,∗1 K. Matsui,∗10 T. Motobayashi,∗1 D. Nishimura,∗11 S. Ota,∗3
E.C. Pollacco,∗5 H. Sakurai,∗1,∗10 C. Santamaria,∗5 Y. Shiga,∗4 D. Sohler,∗12 and R. Taniuchi∗10Counts / 25 keV

In recent years, several experimental findings generated a large interest regarding the E2 strength patternin the tin isotopes. While the neutron-rich isotopes
with A = 126, 128, 130 follow the anticipated trend ofsmoothly decreasing B(E2)↑ values towards the major
shell closure well described by large-scale shell-model(LSSM) calculations1,2) , the proton-rich nuclei take adifferent path. Commencing with the stable A = 114
isotope a steadily growing deviation from the shellmodel expectations was observed with almost constantB(E2)↑ values for the A = 106 − 112 isotopes1–3) . A
first attempt for 104 Sn with limited statistics has recently been made4) . The result of 0.10(4) e2 b2 indicates a steep decrease of excitation strength in agreement with LSSM calculations. In a second measurement, a considerably larger value of 0.180(37) e2 b2 was
obtained5) . Here, we report on the first B(E2)↑ extraction of 104 Sn from absolute Coulomb excitation crosssections at intermediate energies.
A 124 Xe primary beam was accelerated up to an energy of 345 MeV/nucleon and impinged on a 3 mm
thick Be production target at the F0 focus of the BigRIPS fragment separator6). The Bρ − ∆E − Bρ
method was applied to select and purify secondary
beams of 104 Sn and 112 Sn in two subsequent measurements. The secondary beams were transported to the
focal point F8, where a 557 mg/cm2 thick Pb target
was inserted to induce Coulomb excitation reactions.
+
To detect γ-rays from the 2+
1 → 0gs transitions, thereaction target was surrounded by the DALI2 array7).
Reaction products were identified behind the reaction
target by the ZeroDegree spectrometer1) .
A B(E2)↑ value of 0.173(28) e2 b2 was deduced for104
Sn. The run with 112 Sn, which has a known B(E2)↑800

Experiment
Simulation 1253 keV
Background Fit
Sim. + Background

a)

600

*

Pb(112Sn,112Sn )400

Counts / 25 keV

200

300

Experiment
Simulation 1258 keV
Background Fit
Sim. + Background

b)

200

*

Pb(104Sn,104Sn )

100
500

1000

1500

2000 2500 3000
Energy (keV)

Fig. 1. Doppler corrected γ-ray spectra of 112 Sn (top panel+a) and 104 Sn (bottom panel b). The observed 2+
1 → 0gstransitions are compared to simulations.

value, was used for feeding estimations. Our result
is in agreement with the 0.180(37) e2 b2 obtained inRef.5) with largely overlapping error bars, but deviates significantly from the value of 0.10(4) e2 b2 obtained in Ref.4) . The drop in excitation strength ismuch smoother than suggested in Ref.4) and cannot be
reproduced by present LSSM calculations using standard effective charges as well as proton and neutron
excitation across the N = Z = 50 shell.

†

Condensed from the article in Phys. Rev. C 90, 061302(R)(2014).
∗1 RIKEN Nishina Center∗2 Research Center for Nuclear Physics, Osaka University∗3 Center for Nuclear Study, University of Tokyo∗4 Department of Physics, Rikkyo University∗5 CEA Saclay∗6 State Key Laboratory of Nuclear Physics and Technology,
Peking University∗7 Niewodniczanski Institute of Nuclear Physics, Polish
Academy of Sciences∗8 National Institute of Technology, Ichinoseki College∗9 Instituto de Estructura de la Materia, CSIC
∗10 Department of Physics, University of Tokyo∗11 Department of Physics, Tokyo University of Science∗12 Institute for Nuclear Research of the Hungarian Academyof Sciences

References
1) A. Banu et al., Phys. Rev. C 72, 061305 (2005).
2) A. Ekström et al., Phys. Rev. Lett. 101, 012502 (2008).
3) C. Vaman et al., Phys. Rev. Lett. 99, 162501 (2007).
4) G. Guastalla et al., Phys. Rev. Lett. 110, 172501 (2013).
5) V. Bader et al., Phys. Rev. C 88, 051301(R) (2013).
6) T. Kubo et al., Prog. Theor. Exp. Phys. 2012, 03C003(2012).
7) S. Takeuchi et al., Nucl. Instr. Meth. A 763, 596 (2014).

-4-

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

First campaign of the SEASTAR project
P. Doornenbal,∗1 A. Obertelli,∗1,∗2 G. Authelet,∗1,∗2 H. Baba,∗1 F. Browne,∗3 D. Calvet,∗1,∗2 F. Château,∗1,∗2
L.X. Chung,∗4 A. Corsi,∗1,∗2 A. Delbart,∗1,∗2 Zs. Dombradi,∗5 S. Franchoo,∗6 J.-M. Gheller,∗1,∗2 F. Giacoppo,∗7
A. Gillibert,∗1,∗2 A. Gottardo,∗6 K. Hadynska-Klek,∗7 T. Isobe,∗1 Z. Korkulu,∗5 S. Koyama,∗1,∗8 Y. Kubota,∗1,∗9
V. Lapoux,∗1,∗2 J. Lee,∗10 M. Lettmann,∗11 C. Louchart,∗11 R. Lozeva,∗12 K. Matsui,∗1,∗8 M. Matsushita,∗9
T. Miyazaki,∗1,∗8 S. Momiyama,∗8 T. Motobayashi,∗1 M. Niikura,∗1,∗8 S. Nishimura,∗1 L. Olivier,∗6 S. Ota,∗9
H. Otsu,∗1 Z. Patel,∗13 C. Péron,∗1,∗2 A. Peyaud,∗1,∗2 E.C. Pollacco,∗1,∗2 J.-Y. Roussé,∗1,∗2 E. Sahin,∗7
H. Sakurai,∗1,∗8 C. Santamaria,∗1,∗2 M. Sasano,∗1 C. Shand,∗13 Y. Shiga,∗1,∗14 P.A. Söderström,∗1 G.L. Stefan,∗6
D. Steppenbeck,∗9 T. Sumikama,∗1,∗15 D. Suzuki,∗6 S. Takeuchi,∗1 R. Taniuchi,∗1,∗8 T. Uesaka,∗1 Zs. Vajta,∗5
H. Wang,∗1 V. Werner,∗11 J. Wu,∗1,∗16 Z. Xu,∗1,∗10 K. Yoneda,∗1 and the SEASTAR Collaboration
The SEASTAR (Shell Evolution And Search for
Two-plus energies At the RIBF) project aims to measure systematically 2+
1 energies of neutron-rich nuclei
via in-beam γ-ray spectroscopy. Its setup combines the
DALI2 γ-ray spectrometer1) with the MINOS setup
including a liquid hydrogen target system2) , as shownin Fig. 1, while exotic nuclei are produced with Bi66
gRIPS3) . In the first campaign 2+Cr,
1 energies of
70,72
Fe, and 78 Ni were measured with three different
secondary beam settings.
A 238 U primary beam was accelerated to 345
MeV/nucleon and impinged on a 3-mm thick Be target at the entrance of BigRIPS. The beam intensity
varied between 13 to 15 particle-nA. The spectrometer was tuned for 67 Mn, 71,73 Co, and 79 Cu ions toenable (p, 2p) reactions and to populate 2+
1 states in
the above mentioned nuclei. Particle identification was
performed with the Bρ-∆E-TOF method, employing
standard BigRIPS detectors. Beam energies in frontof the MINOS target were around 250 MeV/nucleon,
beam purities in the order of 0.1–0.3 %, and total intensities of 4 to 6 kHz.
The MINOS and DALI2 setups were installed at theF8 focus. A reaction target thickness of 102 mm was
employed for all three settings. A key feature of the
MINOS system was its time projection chamber, whichenabled to reconstruct vertex positions of (p, 2p) (andalso (p, 3p)) reactions with an accuracy of a few mm2) .
DALI2 was employed in its standard configuration of
186 large-volume NaI(Tl) detectors. However, MINOS

Fig. 1. Schematic view of the SEASTAR setup with the
MINOS time projection chamber (yellow) mounted inside DALI2.

was installed further upstream than reaction targets
are usually employed, resulting in an azimuthal angular coverage of DALI2 between 10◦ and 100◦.
Reaction products were identified with the spectrometer ZeroDegree3), providing again particle identification via the Bρ − ∆E−TOF method with standard detectors. ZeroDegree was tuned for the (p, 2p)
reaction channel in MINOS, resulting in total rates between 450 and 1200 Hz.
Data were collected for 7.5 days during the three settings in total, while secondary beam production withBigRIPS took 1.5 days and 1 day was used for user
tuning. The 2+
1 energies were observed on-line for the66
Cr, 70,72 Fe, and 78 Ni isotopes. Currently, these data
as well as many by-products are under analysis by several groups belonging to the SEASTAR collaboration.

∗1

RIKEN Nishina Center
CEA Saclay∗3 School of Computing Engineering and Mathematics, University of Brighton∗4 INST Hanoi∗5 MTA Atomki∗6 IPN Orsay∗7 Department of Physics, University of Oslo
∗8 Department of Physics, The University of Tokyo∗9 Center for Nuclear Study, The University of Tokyo∗10 Department of Physics, The University of Hong Kong
∗11 Institut für Kernphysik, TU Darmstadt∗12 IPHC Strasbourg∗13 Department of Physics, University of Surrey∗14 Department of Physics, Rikkyo University∗15 Department of Physics, Tohoku University∗16 Department of Physics, Peking University∗2

References
1) S. Takeuchi et al.: Nucl. Instr. Meth. A 763, 596 (2014).
2) A. Obertelli et al.: Eur. Phys. J. A 50, 8 (2014).
3) T. Kubo et al.: Prog. Theor. Exp. Phys. 2012, 03C003.

-5-

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Fragmentation of 137 Cs and 90 Sr on proton and deuterium
H. Wang,∗1 H. Otsu,∗1 H. Sakurai,∗1 D. Ahn,∗1 M. Aikawa,∗2 H. Baba,∗1 P. Doornenbal,∗1 T. Fukahori,∗3
N. Fukuda,∗1 T. Isobe,∗1 S. Kawakami,∗4 S. Koyama,∗5 S. Kubono,∗1 G. Lorusso,∗1 Y. Maeda,∗4 A. Makinaga,∗2
S. Momiyama,∗5 M. Niikura,∗5 Y. Shiga,∗1,∗6 P.-A. Söderström,∗1 H. Suzuki,∗1 H. Takeda,∗1 S. Takeuchi,∗1
R. Taniuchi,∗1,∗5 Ya. Watanabe,∗1 and Yu. Watanabe∗7
Properties of long-lived ﬁssion products (LLFP)
have been studied for decades. LLFP nuclei are highly
radioactive, although they are close to the line of β stability. These ﬁssion products are also of great interestfor nuclear engineering as they carry a large weightfraction in the nuclear waste from nuclear reactor systems. Transmutation of the ﬁssion products into stableor short-lived isotopes has been suggested. Aiming at
investigating the LLFP transmutation, we report on
the fragmentation of 137 Cs and 90 Sr on proton anddeuterium in inverse kinematics.
A primary beam U was accelerated to 345 MeV/nucleon,
and it bombarded a 1-mm thick Be target located at
the object point of the BigRIPS fragment separator.
The average beam intensity was about 12 particle nA.
Two secondary beam settings were applied and optimized for the 137 Cs and 90 Sr isotopes. The energies
Fig. 1. Measured cross sections presented as isotope distriwere about 185 MeV/nucleon in front of the secondary
butions for the fragments produced by 137 Cs on proton
targets for both beams. The intensities of the 137 Cs
and deuterium. EPAX and PHITS calculations are disand 90 Sr beams were 1.2×103 and 7.1×103 Hz, withplayed for comparison.
purities of 14% and 28%, respectively.
Three targets, 179.2 mg/cm2 CH2 , 217.8 mg/cm2
CD2 1) , and 226.0 mg/cm2 12 C were used to induce thesecondary reactions. Data were also collected using
an empty target to obtain the contribution from thebeam-line materials. Reaction products were identiﬁedby the ZeroDegree spectrometer using the TOF-Bρ∆E method. A total kinetic energy measurement was
performed for identiﬁcation of the charge states. In
order to cover the fragments over a wide range, several
settings in ZeroDegree were applied.
The isotopic distributions of the fragmentation crosssections for the 137 Cs and 90 Sr beams on proton anddeuterium are shown in Figs. 1 and 2, respectively.
The proton- and deuterium-induced cross sections werededuced from the CH2 and CD2 targets, respectively,
after subtraction of the carbon contributions by the
C target as well as the background contributions by
the empty target run. The validation of the cross secFig. 2. Same as Fig. 1 but for 90 Srtion values was around 1 mb, as determined by statis2)
tics. The results are generally reproduced by PHITS ,while EPAX3) shows some discrepancies for the multiReferences
nucleon removal channels.
∗1
∗2
∗3
∗4
∗5
∗6
∗7

1) Y. Maeda et al.: Nucl. Instr. Meth. A 490, 518 (2002).
2) T. Sato et al.: J. Nucl. Sci. Technol. 50, 913 (2013).
3) K. Sümmerer and B. Blank: Phys. Rev. C 61, 034607(2000).

RIKEN Nishina Center
Faculty of Science, Hokkaido University
Japan Atomic Energy Agency
University of Miyazaki
Department of Physics, University of Tokyo
Department of Physics, Rikkyo University
Kyushu University-6-

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

Missing-mass spectroscopy of tetra-neutron system via exothermic
double-charge exchange reaction 4 He(8 He,8 Be)4n
K. Kisamori,∗1,∗2 S. Shimoura,∗2 H. Miya,∗1,∗2 M. Assie,∗3 H. Baba,∗1 T. Baba,∗4 D. Beaumel,∗1,∗3
M. Dozono,∗1 T. Fujii,∗1,∗2 N. Fukuda,∗1 S. Go,∗1,∗2 F. Hammache,∗3 E. Ideguchi,∗5 N. Inabe,∗1 M. Itoh,∗6
D. Kameda,∗1 S. Kawase,∗2 T. Kawabata,∗4 M. Kobayashi,∗2 Y. Kondo,∗1,∗7 T. Kubo,∗1 Y. Kubota,∗1,∗2
M. Kurata-Nishimura,∗1 C. S. Lee,∗1,∗2 Y. Maeda,∗8 H. Matsubara,∗1 S. Michimasa,∗2 K. Miki,∗5 T. Nishi,∗1,∗9
S, Noji,∗10 S. Ota,∗2 S. Sakaguchi,∗1,∗11 H. Sakai,∗1 Y. Sasamoto,∗2 M. Sasano,∗1 H. Sato,∗1 Y. Shimizu,∗1
A. Stolz,∗10 H. Suzuki,∗1 M. Takaki,∗2 H. Takeda,∗1 S. Takeuchi,∗1 A. Tamii,∗5 L. Tang,∗2 H. Tokieda,∗2
M. Tsumura,∗4 T. Uesaka,∗1 K. Yako,∗2 Y. Yanagisawa,∗1 and R. Yokoyama∗2
neutron system, as shown in Fig. 1. The spectrum
contains 28 events including background events. The
background events were estimated from the the number of events that was not identified as multi-particle
in one bunch in the MWDC at F6. There were only
2.2 ± 1.0 events in the whole spectrum region, which isalmost negligible compared to the selected 28 events.
The excitation energy (E4n ) of the spectrum was calibrated using the peak position of the 8 Li(1+ ) state andthe scale of magnetic rigidity of the SHARAQ spectrometer. 8 Li was produced by the inverse kinematicsof the (p,n) reaction of 8 He. The uncertainty of theenergy determination accuracy was 1.25 MeV at theone sigma level. The resolution of the spectrum was
1.16 MeV at the one sigma level.
The events were concentrated in the low-excitationenergy region of 0 < E4n < 2 MeV and a continuum
were observed at a region of E4n > 2 MeV. The meanof the four events at 0 < E4n < 2 MeV was 0.83 ±0.25 MeV. The possibility of the resonance state at thelow-energy region and the shape of the continuum will
be discussed in comparison with results of a theoretical calculation assuming the correlation of di-neutron
clusters.
+>+).?/@/2/4+5
events / 4 MeV

Since the report on candidates of a bound tetraneutron system1) , multi-neutron systems in nuclei haveattracted considerable attention on both the experimental and theoretical fronts. On the other hand,later theoretical studies using ab-initio calculations2)
have suggested that the tetra-neutron cannot exist as
a bound system but possibly as a resonance system.
We performed missing-mass spectroscopy of the 4nsystem via the exothermic double-charge exchange reaction 4 He(8 He,8 Be)4n3) . The primary goal of the experiment was to determine the energy level and its
width of the 4n system. In order to produce the 4nsystem with a small momentum transfer of less than
20 MeV/c, a secondary beam of 8 He with a large internal energy was used.
The experiment was performed at the RIKEN RI
Beam Factory (RIBF) using the SHARAQ spectrometer and a liquid He target system4) . We measured themomentum of the 8 He beam at BigRIPS-F6 with theHigh-Resolution Beamline and the momenta of two alpha particles, which were the decay products of the8
Be ejectile, with the SHARAQ spectrometer. The incident beam energy of 8 He was 186 MeV/u.
Events resulting from the 4 He(8 He,8 Be)4n reaction
were selected. Two α particles from the 8 Be ejectile
were detected simultaneously at the final focal planeof the SHARAQ spectrometer. Furthermore, a method
to reconstruct trajectories for more than two particles
under a high-intensity beam (∼2 MHz) was developed5). In order to a obtain good signal-to-noise ratio, it
was important to identify multi-particles in one bunch,which have the possibility to create the background
events. These events were rejected using the MultiWire Drift Chamber (MWDC) at F6.
We obtained the missing-mass spectrum of a tetra-

:2
14
12
:8
10
:9

!"#$%&'()*
background

Preliminary!"#$%&%'(")

wave
wave packet
packetjust
just after
after reaction
reaction

8A

resonance
resonance

6=

continuum
continuum

42
28
09
-20
789

∗1

-10
7:9

09

10
:9

20
89

30
;9

40
29

50
<9

60
=9

excitationenergy of 4n (MeV)+,#-.".-')/+)+&%0/'1/2)/34+56

Fig. 1. Missing-mass spectrum of tetra-neutron system.

RIKEN Nishina Center
Center for Nuclear Study, the University of Tokyo∗3 IPN, Orsay∗4 Department of Physics, Kyoto University∗5 Research Center Nuclear Physics, Osaka University∗6 Cyclotron and Radioisotope Center, Tohoku University∗7 Department of Physics, Tokyo Institute of Technology∗8 Faculty of Engineering, University of Miyazaki∗9 Department of Physics, the University of Tokyo∗10 National Superconducting Cyclotron Laboratory, Michigan
State University∗11 Faculity of Science, Kyushu University∗2

References
1) F. Marques et al.: Phys. Rev. C 65, 044006 (2002)
2) S. Pieper: Phys. Rev. Lett. 90, 252501 (2003)
3) K. Kisamori et. al.: Accelerator Progress Rep. 45 (2012)4) M. Kurata-Nishimura et. al.: Accelerator Progress Rep.
46 (2013)
5) K. Kisamori et. al.: Accelerator Progress Rep. 46 (2013)-7-

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Laser-RF double resonance spectroscopy of 84−87 Rb isotopes trappedin superfluid helium†
X.F. Yang,∗1,∗2 T. Furukawa,∗1,∗3 T. Wakui,∗1,∗4 K. Imamura,∗1,∗5 T. Fujita,∗1,∗6 Y. Mitsuya,∗1,∗5
M. Hayasaka,∗1,∗7 Y. Ichikawa,∗1 Y. Ishibashi,∗1,∗9 H. Shirai,∗1,∗8 T. Suzuki,∗1,∗8 Y. Ebara,∗3 A. Hatakeyama,∗10
M. Wada,∗1 T. Sonoda,∗1 Y. Ito,∗1 T. Kobayashi,∗11 S. Nishimura,∗1 M. Kurata-Nishimura,∗1 Y. Kondo,∗1,∗8
K. Yoneda,∗1 H. Ueno,∗1 T. Shinozuka,∗4 T. Shimoda,∗6 K. Asahi,∗1,∗8 and Y. Matsuo∗1,∗12


Laser spectroscopy measurements of various isotopes
have provided a number of valuable results, such as
nuclear spins, moments, and charge radii. However, tofurther study exotic atoms that are far from stability, higher eﬃciency and higher resolution are strongly
required to overcome certain experimental limitations(low yield, limited beam time, large contaminations,and so on). Therefore, a new method called OROCHI
was developed for laser spectroscopy measurements ofradioactive isotopes (RIs) in superﬂuid helium (He II)using a small and controllable number of atoms.1) In
this method, using He II as the trapping medium forthe energetic ion beam and matrix for trapped atoms,
we aim to systematically determine the nuclear spins and moments of RIs with a low yield. This measurement is based on the observation of Zeeman andhyperﬁne structures by optical pumping and the double resonance method. Recently, we have succeededin trapping, polarization, and laser spectroscopy measurements of 84−87 Rb isotopes in He II.
A general introduction to the experimental principle and method has been presented elsewhere.2) In thisexperiment, both stable 85,87 Rb and unstable 84,86 Rb
energetic ions produced from the RIPS were counted
accurately and implanted into He II. The number ofatoms injected into He II was on the order of 104 pps for the current setup. Using the trapping position
control system, we conﬁrmed the precision of the trapping site (around 1 mm) of atoms in He II by detecting
laser-induced ﬂuorescence (LIF).3) On the basis of thetrapping volume (π × 5 × 5 × 1 mm3 ) of atoms in He
II (ion beam spot size: ϕ ≈ 10 mm), and the observation range (5 × 2 × 2 mm3 ) of the LIF detection system, we estimated that more than 20% of the trapped
atoms were used for laser spectroscopy measurements.
From the number of injected ions and detected LIF
photons, the number of detectable LIF photons from
one injected atom was estimated to be approximately








Fig. 1.: LRDR spectra of Rb isotopes trapped in He II. The
red solid line is the fitting function, as described in Ref.4)

0.2 - 0.3.
After the precise trapping of 84−87 Rb in He II, theatoms were optically pumped and polarized with a polarized laser light. In addition, laser-RF double resonance spectra of the 84−87 Rb atoms were measured
by monitoring the LIF signal as a function of the scanned external magnetic ﬁeld with a ﬁxed-frequency
transverse RF ﬁeld applied to the atoms, as shownin Fig. 1. Relatively high spin polarization (above40%) was achieved for the 84−87 Rb isotopes,4) which
was estimated from the diﬀerence in the LIF intensity between the linearly and circularly polarized laser.
The resonance peaks provide information regarding the
Zeeman splitting of atoms in a magnetic ﬁeld. Fromthese Zeeman resonance peaks, nuclear spin values for
84m,84−87
Rb isotopes were determined with reasonableaccuracy, after eliminating the eﬀect of the backgroundmagnetic ﬁeld.
In conclusion, we performed the eﬀective trapping
and laser spectroscopy measurements of 84−87 Rb isotopes with a controllable number of atoms in He II
using the newly developed method. The achievementof high trapping eﬃciency and high spin polarizationand the determination of the nuclear spins of RIs in
He II suggest the potential application of this method
to the study of various exotic particles in He II.

†

Condensed from the article in Phys. Rev. A 90, 052516(2014)∗1 RIKEN Nishina Center∗2 Nuclear and Radiation Physics Section, KU Leuven∗3 Department of Physics, Tokyo Metropolitan University∗4 Cyclotron Radioisotope Center, Tohoku University∗5 Department of Physics, Meiji University∗6 Department of Physics, Osaka University∗7 Department of Physics, Tokyo Gakugei University∗8 Department of Physics, Tokyo Institute of Technology∗9 Department of Physics, University of Tsukuba∗10 Department of Applied Physics, Tokyo University of Agriculture and Technology∗11 Laser Technology Laboratory, RIKEN∗12 Department of Advanced Sciences, Hosei University

References
1) T. Furukawa et al.: Hyp. Int. 196, 191 (2010).
2) T. Furukawa et al.: Nucl. Instrum.Methods B 317, 590(2013).
3) X. Yang et al.: Nucl. Instrum.Methods B 317, 599(2013).
4) X. Yang et al.: Phys. Rev. A 90, 052516 (2014).

-8-

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

RI beam production at BigRIPS in 2014
N. Fukuda,＊1 Y. Shimizu,＊1 H. Takeda,＊1 H. Suzuki,＊1 D.S. Ahn,＊1 N. Inabe,＊1 D. Murai,＊1,＊2 K. Yoshida,＊1 H. Sato,＊1
Y. Sato,＊1 K. Kusaka,＊1 Y. Yanagisawa,＊1 M. Ohtake,＊1 D. Kameda,＊1 and T. Kubo＊1
RI beam production at the BigRIPS fragment separator1)
in 2014 is presented. Table 1 lists the experimental
programs carried out at BigRIPS in this period and the RI
beams produced for each experiment.
The beam time at the RIBF started in March with the
Uranium beam campaign, in which 6 experiments were
performed. The long-lived fission products, 137Cs and 90Sr,
were produced by the in-flight fission of the 238U beam toinvestigate their nuclear-transmutation reaction2). Owing totheir proximity to the -stability line, we experienced
difficulties in improving the purities of the isotopes ofinterest.
The 55Ca and 56Ca beams were produced by projectile
fragmentation of a 70Zn beam for a direct massmeasurement at the SHARAQ spectrometer. A spectroscopyof deeply-bound pionic atoms was performed using the
BigRIPS separator as a high-resolution spectrometer. The
spring beam time ended with the 16O beam experiment at

the SHARAQ spectrometer.
The autumn beam time began in October with the second
Uranium beam campaign, which consisted of 6 experiments.
First, a machine study was conducted to study particle
identification and isotope separation when producing
heavier beams with an atomic number (Z) of around 803). It
was the first attempt at the RIBF. The 172Dy and 170Dy
beams were delivered to the EURICA experiment. The
RI-beam production around Z = 65 at BigRIPS has been
pioneered in recent new-isotope-search experiments4, 5).
The 48Ca primary beam was provided with a highintensity of approximately 500 pnA. Such a high-intensity
beam made it possible to search for the neutron drip line for
the F, Ne, and Na isotopes.
The experiments to search for new neutron-rich isotopes
were performed using the in-flight fission of a 238U beam5, 7),
as shown in Table 1. A total of 28 new isotopes wereidentified in the preliminary analysis.

Table 1. List of the experimental programs and RI beams produced at the BigRIPS in 2014 (in chronological order).
Primary beam
Proposal No.
CourseRI beam (Primary beam)
132
Sn
NP1306-SAMURAI17
SAMURAINP1306-SAMURAI14
SAMURAI(238U)
238
130
U
Cd
NP1306-RIBF31R1
ZeroDegree
137
Cs, 90Sr
345 MeV/u
DA14-01
ZeroDegree
DA14-02-01
BigRIPS
New isotope search (Z ~ 55—70 region)79
Cu, 73Co, 67Mn
NP1312-RIB118
ZeroDegree70
Zn56
Ca, 55Ca, 54Sc
NP1312-SHARAQ3R
SHARAQ
345 MeV/u2
H
1
H, 3He *(d, 3He) reaction for pionic atom
NP1312-RIBF54R1
BigRIPS
250 MeV/u
16O
1
H, (16O)
NP1112-SHARAQ08
SHARAQ
250 MeV/u
MS-EXP13
BigRIPS
RI-beam production in the region of Z ~ 80
82
NP1012-RIBF63
BigRIPS
Ga
aa238
132
U
Sn, 128Sn
NP1012-RIBF61
ZeroDegree
70Ni
345 MeV/u
NP1306-RIBF51R1
ZeroDegree
DA14-02-02
BigRIPS
New isotope search (Z ~ 33 region)
172
Dy, 170Dy
NP1112-RIBF88R1
EURICA24
O, 22O, 20O
NP1312-RIBF56R1
ZeroDegree
48
Ca
19
NP1312-SAMURAI18R1
SAMURAIB, 17B, 14Be, 11Li
345 MeV/u
DA14-02-03
BigRIPS
Drip line search for F, Ne, Na＊1＊2

RIKEN Nishina Center
Department of Physics, Rikkyo University-9-

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Fig. 1 shows the nuclear chart, in which all the isotopes
produced at the BigRIPS from the commissioning in March
2007 to December 2014 are indicated along with the newisotopes observed at BigRIPS. The number of RI-beams
produced amounted to approximately 350, and the numberof new isotopes reached approximately 140. Production
yields for more than 1,000 isotopes were obtained.
The number of experiments using RI beams at BigRIPS
is tallied in Table 2, for various primary beams in each year.
A total of 89 experiments have been performed so far.

References

1) T. Kubo: Nucl. Instr. Meth. B 204, 97 (2003).
2) H. Wang et al.: In this report.
3) N. Inabe et al.: In this report.
4) D. Kameda et al.: RIKEN Accel. Prog. Rep. 46, 20 (2013).
5) N. Fukuda et al.: In this report.
6) N. Inabe et al.: In this report.
7) Y. Shimizu et al.: In this report.

As of December 2014

RI beams produced (354)
Production yield (1024)
New isotopes 2007, 2008 (47)
New isotopes 2011 (30)
New isotopes 2012 (26)
New isotopes 2013 (8)124Xe

New isotopes 2014 (28)5082238U In-flight fission

Z

70Zn

28

50

20

48Ca

18O

8

20
8

28

N

Fig. 1. RI beams produced at the BigRIPS separator from March 2007 to December 2014.
Table 2. Number of experiments using RI beams at the BigRIPS.
238
124
86
70
48
18
Year
U
Xe
Kr
Zn
Ca
O
‘07
4
1
‘08
2
4
‘09
3
3
‘10
10
1
‘11
4
2
2
‘12
6
3
1
4
6
‘13
4
2
3
‘14
11
1
3
Total
34
7
1
2
24
12

- 10 -

16

O

14

N

4

He

3
2

1

5

1

1
1

2

H

1

1
2

Yearly total
5
6
10
14
8
20
9
17
89

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

Neutron drip-line search using 48Ca beam
N. Inabe,*1 N. Fukuda,*1 H. Takeda,*1 H. Suzuki,*1 D. S. Ahn,*1 Y. Shimizu,*1 D. Murai,*2 H. Sato,*1 Y. Sato,*1
K. Kusaka,*1 Y. Yanagisawa,*1 M. Ohtake,*1 K. Yoshida,*1 H. Otsu,*1 N. Iwasa,*3 T. Nakamura,*4
O. Tarasov,*5 B. Sherrill,*5 D. Morrissey,*5 H. Geissel,*6 and T. Kubo*1
A neutron drip-line has been determined till O1) of which
the positions using the plastic scintillators. In themass number(A) is 24, three times the atomic number(Z).
drip-line search, A/Z was determined for only the second
However for F, Ne and Na isotopes with A=3Z+4 werehalf (from F5 to F7) in the second stage due to large
found2). The sudden increase in neutron numbers suggests
contaminants at F3 ( > 1 MHz), which is mainly triton.
Figure 1 shows a PID plot for the setting of the drip-linethat there might be a change in the nuclear structure of F.
search of 33F with a running time of 14.3 hours. In thisThe drip-line search is important to investigate how many
neutron number increases and determination of the drip line
measurement live time of data acquisition was 74.5 % andgives some constraints to nuclear models.
the intensity of 48Ca beam was 415 particle nA on average.
The drip-line search was performed by using the
As shown in Fig. 1, 31F was clearly seen but there is no3)
48
BigRIPS with a 345 MeV/u Ca beam of high intensity (>event in the 33F area although an expected value of 33F are
20.7 counts if we assume a production cross section of 33F
400 particle nA). In the search, we used two settings of33
36
39
the BigRIPS for F and Ne& Na. In the two settings,
predicted by EPAX 2.154).
magnetic rigidities before a degrader located at F1 were thesame (9.385 Tm) but those after it were different. The
magnetic rigidities were determined so that 33F for theformer and center of 36Ne and 39Na for the latter became acentral orbit. Radioactive isotopes were produced by the
20 mm Be target. The thickness of the degrader at F1 was
15 mm. A rather thick target and degrader were used so as
not to be over the maximum magnetic rigidities of both the
Figure 1 A/Q vs Z plot for the drip-line search of F.
first and second stage in the BigRIPS. Another degrader
at F5 (7 mm) was used to remove light particles such as
Figure 2 shows the yield systematics of F isotopes withtriton. Widths of momentum slits at both F1 and F5 wereprediction of EPAX 2.15 (solid line). The measured yields±120 mm and those of both F2 and F7 slits were ±20 mm.
A collimator made using iron was located upstream of F2 to
are in good agreement with those of EPAX2.15.
remove triton, 6He of long stopping ranges that could not be
removed by the F2 slit. The length of the collimator for
beam direction was 450 mm and the opening widths were
±35 mm at the entrance and ±20 mm at the exit. In
order to study yield systematics, we measured the yields of
23~31
F, 34Ne, and 37Na using the same settings of the target,
degraders, and slits as the drip-line search. We alsostudied the secondary reaction effect in the target whereinisotope A is produced in 2 steps via a different isotope B(Here A is produced by 48Ca->B->A). In this study weFigure 2
Yield systematic of F isotopes.
measured target thickness dependence (Be 5 mm, 10 mm
and 20 mm) of the production yields using 37Na.
We estimated probability that 33F is 0 count in theParticle identification (PID) was performed bydetermination of Z and A/Z event by event using themeasurement by applying the expected value (20.7 counts)
E-TOF-B method. The E was measured using fourto the Poisson distribution. The estimated probability is
300 m Si stacks, the MUSIC, and plastic scintillators at F70.000000103 % and this implies that the probability that 33F
redundantly.
TOF was measured using 2 plastic
is unbound is 99.999999897% in this assumption. In the
scintillators at F5 and F7. B was determined by track
study of the secondary reaction effect, we did not observe a
reconstruction using positions and angles measured bylarge enhancement at the thick target as expected. Detailed
PPACs located at F5 and F7. Because around Z=10,
analysis including the 36Ne&39Na setting is in progress.
efficiency of the PPAC was not 100 %, we also measured
References
RIKEN Nishina Center
Department of Physics, Rikkyo University＊3
Department of Physics, Tokyo Institute of Technology＊4
Department of Physics, University of Tohoku＊5Michigan State University (MSU)＊6
Gesellschaft fuer Schwerionenforshung mbH (GSI)＊11) H. Sakurai et al: Phys. Lett. B 448, 180 (1999).
2) M. Notani et al: Phys. Lett. B 542, 49 (2002).
3) T. Kubo: Nucl. Instr. Meth. B 204, 97 (2003).
4) K. Sümmerer: Phys. Rew. C 61, 034607 (2000).

＊2- 11 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

- 12 -

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

Measurement of high-pT neutral mesons with a high-energy photon
trigger in ALICE
S. Yano∗1,∗2 and K. Shigaki∗1

0

E

0

d3 σ pp→π X
11 Nπ
1 1 σMB=(1)dp3
2π pT Nevt ε × Acc BR ∆y∆pT

Here σM B is the cross-section of minimum-bias (MB),0N π is the number of reconstructed neutral pions, and
Acc is the PHOS acceptance correction. Nevt is thenumber of analyzed events in the minimum-bias trigger data analysis. In case of the PHOS trigger data
analysis, it is the number of analyzed PHOS trigger
events times the rejection factor. In the minimum-bias
trigger data analysis, ε indicates the reconstruction ef∗1
∗2

Department of Physics Science, Hiroshima University
RIKEN Nishina Center- 13 -

ﬁciency, whereas in the PHOS trigger data analysis, it
indicates the reconstruction eﬃciency times the trigger
eﬃciency for a neutral-pion meson.
The invariant cross-section of a neutral pion in pp
collisions at LHC energies are shown in Fig. 1. As
shown in Fig. 1, the 0.9, 2.76 and 7 TeV analyses
used only minimum-bias (MB) trigger data, but the 8
TeV analysis (this analysis) used not only minimumbias but also PHOS trigger data. The very-low pT(∼ 1GeV/c) region cross-section was measured by the
Photon Conversion Method (PCM)2) with the tracking detectors of the central burrel1) . For the 8 TeV
result, the minimum-bias and PHOS trigger data werecombined to measure the very wide pT range neutralpion meson. The dashed line denotes the result ﬁtted
to Tsalis functions.
Ed3σ/dp3 (pb GeV-2/c3)

ALICE, one of the experiments at the Large Hadron
Collider (LHC) at CERN, is aimed at studying heavyion collisions and the properties of a deconﬁned stateof matter, the quark-gluon plasma (QGP)1) . High-pT
particle production is a powerful tool for characterizing
the QGP because the interaction between its fast partons depends on the QGP transport properties. The
hadron yields in heavy-ion collisions can be quantiﬁed by the nuclear modiﬁcation factor (RAA ), whichis the ratio of the particle yield in heavy-ion collisions
normalized by the number of inelastic nucleon–nucleon
collisions to the yield in pp collisions. Previous experiments have shown that RAA at high pT is signiﬁcantly
smaller than 1, which can be explained by the energy
loss of fast partons traversing in QGP.
The ALICE experiment includes a high-resolution
and high-granularity electromagnetic calorimeter called
PHOS1) . One of the main physics goals achievable
by PHOS is the study of energy loss through themeasurement of high-pT neutral mesons (π 0 and η).
Three PHOS modules are installed in the ALICE experiment, which covers azimuthal angles in the range
260◦ < ϕ < 320◦ and pseudorapidity |η| < 0.125.
PHOS provides a photon trigger (PHOS trigger) by requiring the measured energy to be above a threshold.
The threshold
was set to be 2 and 4 GeV in pp colli√
sions at s = 8 TeV. By using the PHOS trigger, highpT neutral mesons can be eﬃciently measured in the
ALICE experiment. This paper discribes the analysis
status of neutral-pion production measured with thePHOS trigger and minimum-bias (MB) trigger data in
pp collisions.√ Further, neutral-pion production in pp
collisions at s = 8 TeV are compared with results forother LHC energies (0.9, 2.76 and 7 TeV)2)3) . In thisanalysis, 0.3nb−1 and 70nb−1 MB-trigger and√ PHOStrigger data respectively, in pp collisions at s = 8TeV
are used.
The invariant cross-section can be calculated as

pp s = 8 TeV
pp s = 7 TeV × 10-1
pp s = 2.76 TeV × 10-2
-3

pp s = 900 GeV × 10

110p (GeV/c)T

Fig. 1. Neutral-pion cross section in pp collisions at LHC
energies.

By comparing the results for diﬀerent LHC energies, pertubative Quantum Chromodynamics (pQCD)
can be tested at LHC energies and the fragmentation
function (FF) of gluon to the neutral-pion model canbe restricted. Further, this comparison can help predict a neutral-pion production cross-section in pp collisions at other energies. This has not been measured
yet and more precise references to study phenomena
induced by AA collisions can be estimated for QGP
study.
References
1) The ALICE Collaboration, JINST 3, S08002 (2008).
2) The ALICE colaboration, Phys.Lett.B 717 (2012), pp.
162 - 172.
3) The ALICE colaboration, Eur. Phys. J. C (2014) 743108.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Transverse single-spin asymmetries in prompt photon production
from proton-proton collisions†
D. Pitonyak,∗1 K. Kanazawa,∗2 Y. Koike,∗3 and A. Metz∗2
Collinear twist-3 factorization has been used sincethe 1980s in order to describe transverse single-spin
asymmetries AN . For a general process A↑ B → C X,
the cross section can be written as the sum of threeterms depending on which non-perturbative function is
kept at twist-3. For hadron production, which has been
intensely studied for close to 40 years, the distribution
and fragmentation contributions to the cross section
cannot be disentangled, i.e., all of them are summed
together in the cross section. For many years it was often assumed that the piece involving the so-called QiuSterman (QS) function GF (x, x) was the main cause of
AπN . However, this led to a so-called “sign mismatch”
between the QS function and the transverse momentum dependent (TMD) Sivers function extracted fromsemi-inclusive deep-inelastic scattering (SIDIS)1) . Recently we showed in 2) for the first time that the fragmentation contribution in collinear twist-3 factorization actually can describe AπN very well. By using a
Sivers function fully consistent with SIDIS, we demonstrated that this mechanism could also resolve the signmismatch puzzle. Nevertheless, an independent extraction of GF (x, x), through observables like Ajet
N and
AγN , is crucial to confirm this assertion. However, oneγmust keep in mind that for Ajet
N and AN other twist-3
distribution effects can enter besides the QS function.
Thus, in order to have a “clean” extraction of GF (x, x),
it would be ideal if these other terms were small.
Therefore, we return to the SSA in p↑ p → γX
to see if this reaction could provide such an observable. In twist-3 collinear factorization, AγN has contributions from multiparton correlators inside either thetransversely polarized proton or the unpolarized proton. For this process the former has been widely discussed in the literature for both (twist-3) quark-gluonquark3–10) and tri-gluon11) non-perturbative functions,which are chiral-even objects evaluated at either softgluon or soft-fermion poles (SGPs/SFPs). The full
result for twist-3 effects on the side of the unpolarized proton is a new piece from this work and, although we refrain from showing the explicit formulafor brevity, will be included in our numerical analysis. This term involves a chiral-odd quark-gluon-quark
correlator EF (x, x), which is related to the TMD BoerMulders function.
We now focus on the phenomenology. For the SGP
correlators EF (x, x) and GF (x, x) we make use of iden†

∗1
∗2
∗3

Condensed from the article in PRD 91, 014013 (2015)
RIKEN Nishina Center
Department of Physics, Temple University
Department of Physics, Niigata University- 14 -SS 
� 510
510 GeV,
GeV, ΗΗ 
� 3.5
3.5

A
ANN
Γ
Γ

0.2
0.2

0.4
0.4

0.6
0.6

0.8
0.8

xxFF

0.005
�0.005
0.010�0.010Total
Total
ΧΧ�ee SGPSGPΧΧ�oo SGPSGPΧΧ�ee SFP
SFP

0.015
�0.015
0.020�0.0200.025
�0.025

Fig. 1. AγN vs. xF at fixed η = 3.5 and√S = 510 GeV.

tities that relate the first to the Boer-Mulders function
and the second to the Sivers function. Since at thispoint no information on the SFP functions is available, F (0, x) = GF (x, x).
we assume the relation GF (0, x)+G
Model calculations of quark-gluon-quark correlatorsshow that chiral-even SFP functions are much smaller
as compared to the SGP one and might even vanish.
Therefore, we believe that this ansatz is reasonable.
In Fig.1 we show an estimate of AγN (along with anuncertainty band) from all these pole contributions fora set of kinematics relevant for the measurement of
this observable at PHENIX and STAR. One sees thatthe entire effect is due to the “Sivers-type” QS mechanism. Using the Sivers function extracted from SIDIS,
our results show that AγN could be on the order of several (negative) percent in the forward region, providing a “clean” observable to extract of the QS function
GF (x, x). In light of the “sign-mismatch” crisis involving GF (x, x) and the Sivers function1) , and the recently proposed solution to this issue that relies on thetwist-3 fragmentation mechanism2) , such an extraction
is of vital importance. In addition, one can obtain important information on the process dependence of theSivers function as well as help discriminate between
the Generalized Parton Model and twist-3 formalisms
since the former predicts a positive asymmetry. Thus,
measurements of this process by PHENIX and STARare crucial.
References
1) Z.-B. Kang et al., Phys. Rev. D 83, 094001 (2011).
2)K. Kanazawa et al., Phys. Rev. D 89, 111501(R) (2014).
3)J.-w. Qiu and G. Sterman, Nucl. Phys. B 378, 52 (1992).
4) X. Ji et al., Phys. Rev. D 73, 094017 (2006).
5) C. Kouvaris et al., Phys. Rev. D 74, 114013 (2006).
6) Y. Koike and K. Tanaka, Phys. Lett. B 646, 232 (2007)[Erratum-ibid. B 668, 458 (2008)].
7)K. Kanazawa and Y. Koike, Phys. Lett. B 701, 576 (2011).
8)L. Gamberg and Z.-B. Kang,Phys. Lett. B 718, 181 (2012).
9)K. Kanazawa and Y. Koike, Phys. Lett. B 720, 161 (2013).
10) L. Gamberg et al., Phys. Rev. Lett. 110, 232301 (2013).
11)Y. Koike and S. Yoshida, Phys. Rev. D 85, 034030 (2012).

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

Entanglement entropy of de Sitter space α-vacua†
N. Iizuka,∗1 T. Noumi,∗2 and N. Ogawa∗2
The de Sitter space is a very interesting space-time.
It is a solution of Einstein equation when cosmologicalconstant dominates, and it is related to the inflationary
stage of our universe, as well as to the current stageof accelerating universe. A peculiar property of the deSitter space is that the de Sitter invariant vacuum is
not unique; it has a one-parameter family of invariant
vacuum states |α, called α-vacua1,2) .
The α-vacua give very peculiar behavior for the twopoint functions in the de Sitter space; the two-point
functions on α-vacua between points x and y containnot only the usual short distance singularity δ(|x − y|),where |x − y| is the de Sitter invariant distance between x and y, but also contain very strange singularity such as δ(|x − ȳ|) and δ(|x̄ − y|), where x̄ and ȳ
represent the antipodal points of x and y, respectively.
Since antipodal points in the de Sitter space are notphysically accessible due to the separation by a horizon, one cannot have an immediate reason to discard
two-point functions containing such an antipodal singularity. It is therefore unclear which vacuum should
be realized in our universe. As a result, a number ofstudies have been done on phenomenological aspects ofthe α-vacua (e.g. primordial perturbations generated
during inflation).
Since which vacuum one should choose is always avery important question, one is motivated to calculate
physical quantities not only in a particular vacuum but
also in others, and see if there is a big reason to choose
or discard a particular vacuum.

SEE
V
0.20

0.15

0.10

0.05

0.2

0.4

0.6

0.8

1.0

1.2

1.4

In this work, we computed the entanglement entropy
∗1
∗2

0.10
0.08
0.06
0.04
0.02

1.0

0.5

0.5

1.0

Α

Fig. 2. Plot of SEE /V against α, for ν = 0 (red), 0.25
(orange), νc = 0.4062 . . . (green), 0.43 (blue) and 0.5(purple).

in de Sitter α-vacua. By generalizing the recent calculation by Maldacena and Pimentel3) in the Euclidean(or Bunch-Davies) vacuum for free scalar fields, we derived how entanglement entropy depends on α. The
results are shown in Fig. 1 and Fig. 2.
As is seen in Fig. 2, the entanglement entropy increases significantly as we take α very large for genericvalues of ν. However only for ν = 1/2 and 3/2, thistendency disappears. Note that ν = 1/2 is the conformal mass and ν = 3/2 is massless. It is interesting tounderstand more physically why such a mass dependence occurs.
Our calculation is done for the free scalar field.
Therefore direct comparison with the holographic calculation for the Euclidean vacuum3) is difficult. It
must be interesting to ask how the calculation of entanglement entropy on the α-vacua can be done in
the strong coupling limit via holography, a la RyuTakayanagi formula4) . Understanding these will hopefully shed more light on the question of which vacuum
one should choose in the de Sitter space. We hope tocome back to this question in near future.
ReferencesΝ

Fig. 1. Plot of SEE /V against ν, for α = 0 (red), 0.1 (orange), 0.25 (yellow), 1 (green) and 2 (blue). Notice theperiodicity and reflection symmetries.

†

SEE
V

Condensed from the article arXiv:1404.7487 [hep-th].
Department of Physics, Osaka University
RIKEN Nishina Center- 15 -

1) E. Mottola, Phys.Rev. D31 (1985) 754.
2) B. Allen, Phys.Rev. D32 (1985) 3136.
3) J. Maldacena and G. L. Pimentel, JHEP 1302 (2013)
038, [arXiv:1210.7244].
4) S. Ryu and T. Takayanagi, Phys.Rev.Lett. 96 (2006)
181602, [hep-th/0603001].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Current Reflection and Transmission at Conformal Defects:
Applying BCFT to Transport Process†T. Kimura∗1,∗2 and M. Murata∗3
A powerful method for studying critical phenomena with conformal defects is boundary conformal
field theory (BCFT). However, it has not been completely understood how BCFT describes the reflection/transmission at conformal defects. In this report, we define the reflection/transmission coefficientfor conserved currents, as a natural generalization ofthat based on the energy-momentum tensor.1)
We consider two one-dimensional quantum systems
connected by a junction, which can be considered as
an impurity interacting with the bulk. Let us assume
that the first system is in the positive domain x > 0,
the second is in the negative x < 0, and they are connected at the origin as depicted in Fig. 1(a). Now
we shall describe the above system in terms of BCFT.
Corresponding to the two quantum systems, the BCFT
picture involves two CFTs: CFT1 and CFT2 . These
CFTs are defined in the upper and lower half planes
respectively as depicted in Fig. 1(b). The real axis,
which divides the two CFTs, stands for the world lineof the impurity, or the defect. We can reformulate thissystem to obtain CFT1 ×CFT2 in the upper half plane
thanks to the folding trick,2) as shown in Fig. 2. In thisway, the junction of the one-dimensional quantum systems can be mapped into a CFT boundary condition.

Fig. 2. From the defect to the boundary. By using thefolding trick, a system with the defect is mapped intoanother system defined on the upper half plane withthe boundary.

R-matrix based on this boundary state |B,
j,b

R[C]ij,ab = −0|j1i,a j 1 |B
.
0|B

(1)

Since we have three constraints for this matrix, it has
only one degree of freedom. Letting ωB [C] beb

0|K1a K 1 |B
1,d ωB [C] = −k1 k2 (k1 + k2 )
0|B
ab

the R-matrix is given by

k1
k1 k2
k2
R[C] =
1
k1 + k2

1
k2
k1



+ ωB [C]



(2)

−1
1

1
−1



where dab is the Cartan–Killing form, ki is the levelof the Kac–Moody algebra, and Kna = k2 jn1,a − k1 jn2,a .
We can introduce the reflection and transmission coefficients based on this matrix:
Fig. 1. From the impurity to the defect. (a) Two onedimensional systems are connected through the impurity at x = 0. (b) Adding the time direction and taking
the continuum limit, that system is mapped into thetwo-dimensional system with the defect along the line
x = 0.

We assume that CFT1,2 have the same symmetrysubalgebra C, which is preserved at the conformal defect. For such a defect,the we choose following curtot,arent gluing condition jntot,a + j −n |B = 0, where
ˆ and jjntot,a takes values in the Kac–Moody algebra C,
is the anti-holomorphic part. We then introduce the
†

∗1
∗2
∗3

Condensed from the article in Nucl. Phys. B885 266 (2014)
RIKEN Nishina Center
Institut de Physique Théorique, CEA Saclay
Institute of Physics, ASCR

- 16 -

R[C] =

R11 + R22,
k1 + k2

T [C] =

R12 + R12,
k1 + k2(4)

which satisfy the current conservation R + T = 1. Applying this formula to the coset-type boundary statewith C = su(2),3) we obtain(k +k ) (k +k )S001 2 Sρ11 2
2k1 k2T [su(2)] =1 − (k +k ) (k +k ) ,(5)(k1 + k2 )2
S 1 2 S 1 2
ρ001with the modular
 S-matrix
 of SU(2)k labeled by
 two
(k)

integers, Sρµ =2k+2 sinπ
k+2 (2ρ + 1)(2µ + 1).

References
1) T. Quella et al., JHEP 0704 (2007) 095.
2) M. Oshikawa, I. Affleck, Phys. Rev. Lett. 77 (1996) 2604.
3) T. Quella, V. Schomerus, JHEP 0206 (2002) 028.

,(3)

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

Magnetic field of the slowest rotating neutron starin the symbiotic X-ray binary 4U 1954+319†
T. Enoto∗1,∗2,∗3 , M. Sasano,∗4 S. Yamada,∗5 T. Tamagawa,∗1
K. Makishima∗4,∗6 , and Suzaku 4U 1954+319 Analysis Team
Neutron stars (NSs) are not boring degenerate compact objects with a uniform face, but exhibit a large
variety of observational diversities mainly due to awide range of magnetic field (B-field, ∼ 104 –1012 T),
rotation spin period (P ∼ 10−3 –104 s), and (in somecases) mass accretion from a companion star. Binary
systems with NSs are conventionally classified into
high-mass X-ray binaries (HMXBs, an optical counterpart mass Mc >10M ) or low-mass X-ray binaries(LMXBs, Mc <1–2M ). The former and latter are
thought to host NSs with higher and lower B-field of
107−8 T and 104−6 T, respectively. However, the symbiotic X-ray binary (SyXB) 4U 1954+319 was recently
recognized as a rare system hosting a peculiar NS andM-type companion, and found to be the slowest rotator
among known X-ray pulsars with P ∼5.4 h.
We performed two observations of 4U 1954+319
with the X-ray satellite Suzaku in 2011 (quiescent) and2012 (flare phase), and investigated the spectral andtemporal nature of this peculiar system. Although theoptical counterpart is classified as a “low mass” star,
its X-ray features are quite similar to a wind-fed typeFig. 2. Spectral comparison of 4U 1954+319 with otherlong period pulsars in HMXBs (modified from Enoto etal., 20141) ).

Fig. 3. Schematic view of the quasi-spherical accretionfrom stellar wind in the X-ray binary 4U 1954+3191) .

Fig. 1. The 1–10 keV X-ray count rates of 4U 1954+319
observed with X-ray CCD instruments (X-ray Imaging
Spectrometer) on board the Suzaku satellite1) , during
a quiescent state (panel a and b) and an outburst (cand d) in 2011 and 2012, respectively.
†
∗1
∗2
∗3
∗4
∗5
∗6

Condensed from the article in the Astrophysical Journal
786, 127 (2014)
RIKEN Nishina Center
JSPS SPD Fellow
NASA Goddard Space Flight Center
Department of Physics, University of Tokyo
Department of Physics, Tokyo Metropolitan University
RIKEN MAXI Team- 17 -HMXB system; e.g., 1) high pulsed fraction, ∼60–80%,
2) shot-like mass accretion, characterized by the lognormal distribution of the count rate (Fig.1), 3) broadband spectral similarity to low-luminosity slowly rotating NSs in HMXBs (Fig. 2), and 4) a narrow 6.4
keV Fe-Kα line. Combined with a sign of the spinequilibrium over a long time scale, we proposed a quasispherical accretion regime from a slow stellar windfrom the M-type companion (Fig. 3). Even though
we do not need an extremely strong B-field like magnetars, which were expected from the canonical disk-type
accretion, we still need a higher B-field in the range of
108−9 T as the HMXB-NSs rather than the LMXBNSs. Our study indicates a new interesting subclass of
X-ray pulsars, i.e., SyXBs, and casts a question on its
evolutionary path to make such a peculiar system.
References
1) T. Enoto, M. Sasano, et al: ApJ, 786, 127 (2014)

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Short-term spectral softening of black-hole binary
Swift J1753.5–0127†
A. Yoshikawa, ∗1∗2 S. Yamada,∗3 S. Nakahira,∗4 M. Matsuoka,∗5 H. Negoro,∗6
T. Mihara,∗5 and T. Tamagawa,∗1

†
∗1
∗2
∗3
∗4
∗5
∗6

Condensed from the article in Publications of the Astronomical Society of Japan, 2015, 67, 1, 11
High Energy Astrophysics Laboratory, RIKEN Nishina Center
Department of Physics, Tokyo University of Science
Department of Physics, Tokyo Metropolitan University
ISS Science Project Oﬃce, ISAS, JAXAMAXI team, RIKEN
Department of Physics, Nihon University- 18 -

Normalized
Normalized light
light curves
curves

33
2.5
2.5

(a)
(a)

22
1.5
1.5

↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓
↓

0.7–1.7 keV
keV
0.7–1.7
2–4 keVkeV
2–4
4‒10 keV
keV
4‒10
15–50 keV
keV
15–50

11
0.5
0.5
00

56000
56000

56020
56020

56040
56040

MJD
MJD

56060
56060

56080
56080

55

10
10

(b)
(b)
1.0
1.0
-2 ))
-1 cm
νF
νFνν (keV(keV ss -1
cm -2

The X-ray emission from black-hole binaries (BHBs)
is driven by the release of gravitational energy fromaccreting matter falling into a black hole (BH). The
X-ray intensities are known to fluctuate for approximately weeks or months (outburst). There are twostates: the low-luminosity hard (low/hard) and thehigh-luminosity soft (high/soft) states. The X-ray
spectra of the low/hard state can be well reproduced bya power law with a photon index of 1.4–2.1.1) The spectra of the high/soft state can be explained by opticallythick thermal disk emission (accretion disk2)3) ). Transitions between the low/hard and high/soft states during the outburst have been observed in many BHBs.
The Swift J1753.5–0127 outburst was occurred on
May 30 2005.4) After the outburst, the source flux
peaked on July 9 2005, and then gradually decreased
for more than 9 years. Dips were observed in the
15–50 keV energy range that lasted for approximately
25 days (short-term variation). The dips are interpreted as a possible eclipse by the warped disk.5) Observations with MAXI6) revealed the increase of theintensity in the 2–4 keV energy range during the variation in 2009.7) The increase can not be explained by
the eclipse. To investigate the cause of the short-term
variation, we have studied the X-ray spectrum.
For another short-term variation of the source on
April 23 2012, we succeeded in tracing its spectral time
evolution, as shown in Fig. 1. We overlaid the light
curves for the various energy ranges normalized by themean count rates, which were calculated by averaging over approximately 40 days. The light curves below and above 10 keV were observed using MAXI and
Swift8) , respectively. The hump in the 0.7–4 keV bandand the dip in the 15–50 keV band correspond to thegrowth and decay of the accretion disk, respectively(Fig. 1a). The X-ray spectrum observed by using theSwift-XRT9) changed during the short-term variation(Fig. 1b). The spectrum can be fitted by the emission
model of the accretion disk. The disk temperatures(T in ) and energy fluxes (Fdisk ) changed from 0.48 to
0.2 keV and from 4.8×10−9 to 2.2×10−9 erg s−1 cm−2 ,respectively. The best-fit parameters show the vari-

0.5
0.5

0.1
0.1

0.05
0.05

MJD 56045
56045
MJD
MJD 56047
56047
MJD
MJD 56049
56049
MJD
MJD 56050
56050
MJD
MJD 56053
56053
MJD
MJD 56055
56055
MJD
11

22
Energy (keV)(keV)
EnergyFig. 1. (a) The light curves in energy ranges of 0.7–1.7 keV(red), 2–4 keV (green), 4–10 keV (blue), and 15–50 keV(magenta) normalized by the average value. Arrows
indicate the XRT observations on MJD 56045 (red),
56047 (orange), 56049 (green), 56050 (cyan), 56053(blue), 56055 (magenta), and the other dates (black).
These colors correspond to the spectrum observed on
MJD 56045, 56047, 56049, 56050, 56053, and 56055 in
Fig. (b).

ation of the accretion disk and the state transitions
from the low/hard to high/soft state (softening) during the short-term variation. The F disk and T in did notobey the relationship, F disk ∝ T in 4 , suggesting thatthe structure of the accretion disk changed during thesoftening.
References
1) R. A. Remillard, & J. E. McClintock: ARA&A, 44, 49(2006).
2) K. Mitsuda et al.: PASJ, 36, 741 (1984).
3) K. Makishima et al.: ApJ, 308, 635 (1986).
4) M. D. Palmer et al.: Atel #546 (2005).
5) A. W. Shaw et al.: MNRAS, 433, 740 (2013).
6) M. Matsuoka et al.: PASJ, 61, 999 (2009).
7) H. Negoro et al.: Atel #2341 (2009).
8) S. D. Barthelmy et al.: SSRv, 120, 143 (2005).
9) D. N. Burrows et al.: Proc. SPIE, 4140, 64 (2000).

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)




＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊

                  
                               

        

























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
              
          
      
       
                       

          
               
       

          ＊  

 





＊  



















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     

        
     
      

      
       
       

        
       




          
                          

        
         

        
         
        
                          




         
                        
       
        


        

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Supply of 48Ca beam from 18-GHz ECRIS using the micro-oven
K. Ozeki,＊1 Y. Higurashi,＊1 M. Kidera,＊1 and T. Nakagawa＊1
In order to enhance the intensity and stability of the
Ca beam supplied from the RIKEN 18-GHz Electron
Cyclotron Resonance Ion Source (ECRIS),1) we have been
conducting operational tests on a micro-oven using 40Ca.2)
Owing to the cost of the material in which the 48Ca isotope
is highly enriched (70-80%), it is very important to reduce
its consumption rate. For this purpose, we adopted theso-called “hot liner”3-5) and studied its effect on the
reduction of the consumption rate. In this study, wherein atantalum cylinder and disk of 0.1-mm thick were installed
into the ECRIS, we observed an apparent reduction of thematerial consumption rate by using the hot liner. Details of
the results are described in Ref. 6.
The 48Ca beams for a series of experiments using the
micro-oven have been supplied three times until now. Eachseries of experiments is summarized in Table 1. The
statuses of the beam supply for experiments-1, such as
beam intensity and material consumption rate, are reported
in Ref. 6.
48

Table 1. Supply of the 48Ca beam using a micro-oven.
Days
ChargeBeam course
1
Nov. to Dec. 2013
11+
GARIS, RIPS
2
Sep. to Oct. 2014
11+
GARIS, RIPS
3
Nov. to Dec. 201410+
BigRIPS

Fig. 2. Long-term supply of the 48Ca beam. The beam
intensity for 48Ca10+ (gray) and the oven current (black)are shown.

In the series of experiments-3, the 48Ca beam produced by
the present method was first supplied to the new RIBF
accelerator complex. Figure 1 shows the charge distributionof the 48Ca ions. The RF power fed to the ECRIS was 370 W.

The amounts of 48Ca placed into the crucible andsubsequently consumed were 299 mg and 98 mg,
respectively. The consumption rate of 48Ca was 0.13 mg/h.
We succeeded in supplying stable and highly intense (twice
as high compared to before, at the exit of ECRIS) beamwith low material consumption rate (nearly one-tenth as low
compared to before).
Previously, the peak intensity of the 48Ca beam extracted
from Superconducting Ring Cyclotron was 415 particle nA,
but it was impractical to maintain the beam intensity at thislevel because of insufficient stability and high material
consumption rate. The practical application of the
micro-oven system realized long-term stable supply of the48
Ca beam with an intensity of more than 400 particle nA tousers.7)

Fig. 1. Charge distribution of the 48Ca ions.
The beam intensity at the exit of ECRIS and the ovencurrent are shown in Fig. 2. The beam intensity was
adjusted according to the requirements of the experiment,by changing the aperture of the slit at the exit of ECRIS. A
beam intensity of ~35 electric A with maximum slit
aperture was maintained throughout the experimental
duration.
＊1

References

1) T. Nakagawa et al.: Nucl. Instrum. Methods B 226, 392 (2004).
2) K. Ozeki et al.: Rev. Sci. Instrum. 85, 02A924 (2014).
3) A. Efremov et al.: Rev. Sci. Instrum. 69, 662 (1998).
4) V. B. Kutner et al.: Rev. Sci. Instrum. 71, 860 (2000).
5) P. Lehérissier et al.: Rev. Sci. Instrum. 73, 558 (2002).
6) K. Ozeki et al.: Rev. Sci. Instrum. 86, 016114 (2015).
7) http://www.nishina.riken.jp/RIBF/accelerator/tecinfo.html

RIKEN Nishina Center- 20 -

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

Particle identification for Sn region with SAMURAIJ. Yasuda,∗1 M. Sasano,∗2 R.G.T. Zegers,∗3 H. Baba,∗2 W. Chao ,∗2 M. Dozono,∗2 N. Fukuda,∗2 N. Inabe,∗2
T. Isobe,∗2 G. Jhang,∗2,∗13 D. Kamaeda,∗2 T. Kubo,∗2 M. Kurata-Nishimura,∗2 E. Milman,∗2 T. Motobayashi,∗2
H. Otsu,∗2 V. Panin, ∗2 W. Powell, ∗2 M. Sako, ∗2 H. Sato,∗2 Y. Shimizu,∗2 L. Stuhl,∗2 H. Suzuki,∗2
T. Suwat, ∗2 H. Takeda,∗2 T. Uesaka,∗2 K. Yoneda,∗2 J. Zenihiro,∗2 T. Kobayashi,∗4 T. Sumikama,∗4 T. Tako,∗4
T. Nakamura,∗5 Y. Kondo,∗5 Y. Togano,∗5 M. Shikata,∗5 J. Tsubota,∗5 K. Yako,∗6 S. Shimoura,∗6
S. Ota,∗6 S. Kawase,∗6 Y. Kubota,∗6 M. Takaki,∗6 S. Michimasa,∗6 K. Kisamori,∗6 C.S. Lee,∗6 H. Tokieda,∗6
M. Kobayashi,∗6 S. Koyama,∗7 N. Kobayashi, ∗7 H. Sakai,∗8 T. Wakasa,∗1 S. Sakaguchi,∗1 A. Krasznahorkay,∗9
T. Murakami, ∗10 N. Nakatsuka, ∗10 M. Kaneko, ∗10 Y. Matsuda, ∗11 D. Mucher, ∗12 S. Reichert, ∗12 D. Bazin,∗3
and J.W. Lee∗13∗1Department of Physics,Kyushu University
RIKEN Nishina Center∗3 NSCL Michigan State University∗4 Department of Physics, Tohoku University∗5 Tokyo Institute of Technology∗6 CNS, University of Tokyo∗7 University of Tokyo∗8 ULIC, RIKEN Nishina Center∗9 MTA, Atomki∗10 Kyoto University∗11 Konan University∗12 Technical University Munich∗13 Department of Physics, Korea University∗2

Z
Z

from FDC23) drift chamber which was placed after the
SAMURAI spectrometer. The obtained ∆E resolutionis σ∆E /∆E = 0.43 ± 0.03(stat.) %.
The rigidity was analyzed by using four drift chambers BDC1,2, FDC1 and FDC23) . The obtained rigidity resolution is R/σR = 1318 ± 27(stat.).
Figure. 1(a) shows the PID spectrum with respect
to atomic number Z and mass to charge ratio A/Q.
The Z resolution is σZ = 0.22 corresponding to 4.6σ
separation for Z=50 and 51. The A/Q resolution is
σA/Q = 0.14 % for 132 Sn50+ which corresponds to 5.4σ
separation.
52
52

51.5
51.5
51
51

(a)
(a)

Sb
Sb

135
135

50+
Sn50+
Sn

50
50

1022
10

49+
Sn49+
Sn

132
132

132
132

50.5
50.5

10
10

In
In

49.5
49.5

129
129

49
49
48.5
48.5
48
48

11

47.5
47.5

2000
2000
1800
1800
1600
1600
1400
1400
1200
1200
1000
1000
800
800

2.56
2.56

2.58
2.58

2.6
2.6

2.62
2.62

2.64
2.64

(b)
(b)

2.66
2.66

2.68
2.68

2500
2500

2000
2000

σZZ =
= 0.22
0.22
σ

2.7
2.7

2.72
2.72

2.74
2.74

mass toto charge
charge ratio
ratio (A/Q)
(A/Q)
mass

CountsCounts47
47

CountsCounts

We performed the SAMURAI17 experiment1) at
RIKEN RIBF to study Gamow-Teller transition in132
Sn by (p, n) reaction with the WINDS2) and the
SAMURAI spectrometer3) . The SAMURAI spectrometer was used for tagging (p, n)-reaction events withthe particle identiﬁcation (PID) of the beam heavy
fragments. The PID was performed with the TOF-Bρ∆E method. Here we report the preliminarily resultson the PID.
Here, we used the 132 Sn beam run with empty-target
cell at F13 and selected the non-reacted trigger eventsin order to estimate the resolution of TOF, Bρ and∆E. The beam rigidity was measured by the BigRIPS
with a typical momentum resolution of R/σR ∼ 3000.
The TOF was measured by using the plastic scintillators SBT1,2 and the HODS with ﬂight path lengthL  12.5 m. The HODS consists of 6 plastic scintillation counters with size of 450 mm × 100 mm ×
5 mm. The obtained TOF resolution is σt = 62.1 ±2.7(stat.) ps, where the statistical uncertainty is indicated. It should be noted that the non-uniformity of
SBT1 thickness is as large as about 20 % which corresponds to 1 MeV/nucleon energy loss diﬀerence for 200
MeV/nucleon 132 Sn beam. In this analysis we gatedthe central position of SBT1 to estimate the TOF resolution, by using tracking information from BDC1,23)
drift chamber which were placed between SBT1,2 andthe target. In the following the resolution was estimated with the same manners.
The energy loss ∆E was measured by HODS. The∆E is sensitive to the HODS thickness. In this experiment the non-uniformity of HODS thickness is about
10–20% for 6 counters. In order to correct the thickness dependence, we used the tracking information

1500
1500

1000
1000

(c)
(c)

Sn
Sn

(49.5 << Z
Z << 50.5)
50.5)
(49.5

σA/Q
= 0.14%
0.14%
σ
=
A/Q
132
50+
Sn50+
for 132
Sn
for

600
600
400
400

500
500

200
200
00
47 47.5
47.5 48
48 48.5
48.5 49
49 49.5
49.5 50
50 50.5
50.5 51
51 51.5
51.5 52
52
47

Z
Z

00

2.56 2.58
2.58 2.6
2.6 2.62
2.62 2.64
2.64 2.66
2.66 2.68
2.68 2.7
2.7 2.72
2.72 2.74
2.74
2.56

mass toto charge
charge ratio
ratio (A/Q)
(A/Q)
mass

Fig. 1. (a) A SAMURAI PID spectrum with respect to Z
and A/Q for non-reacted events with empty target cell.
(b) Z distribution for all beam component and (c) A/Q
distribution for Sn isotopes. The resolution of Z and
A/Q are σZ = 0.22 and σA/Q = 0.14% for 132 Sn50+ ,respectively.

References
1) M. Sasano et al., : in this report.
2) J. Yasuda et al.,: in this report.
3) T. Kobayashi et al., Nucl. Instr. Meth. B317, 294 (2013).

- 21 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Results of ﬁrst online tests of small ion-surﬁng RF carpet gas cell at
GARIS-IIP. Schury,∗1 F. Arai,∗1,∗2 H. Haba,∗1 Y. Ito,∗1 I. Katayama,∗1 D. Kaji,∗1 K. Morimoto,∗1 M. Reponen,∗1
T. Sonoda,∗1 M. Wada,∗1 and H. Wollnik∗1,∗3
































Fig. 1. Combined stopping and extraction eﬃciency for205
Fr as a function of degrader thickness. The thickness was varied by rotating the degrader. Gas cell was
operated at room temperature.
∗1
∗2
∗3






beam On/Oﬀ
214Ac



216Th






213Ac

215Ac











217Pa





Fig. 2. α-decay spectra seen on silicon detector after thegas cell. Pulsing the linac beam with a short period, astrong suppression of short-lived isotopes was observed.





Of perhaps greater interest was the stopping andextraction eﬃciency for shorter-lived isotopes. Thiswas studied with a Tantalum target using the reactions 181 Ta(40 Ar,p4n)216 Th and 181 Ta(40 Ar,4n)217 Pa
to produce species with T1/2 of 26 ms and 3.5 ms, respectively. The α-decay spectra seen after the gas cellusing a chopped beam and measuring decays during“beam oﬀ” are shown in Fig. 2. The red spectrum
was measured by quickly pulsing the linac beam while
the green spectrum was measured with longer period
pulses. For the long period beam pulses, short-lived
isotopes extracted during “beam on” decay prior to“beam oﬀ” and are suppressed.
For these beams, having higher-Z and lower energy
than 205 Fr, the degrader was inoptimally thick. However, we were able to set lower limits on the stoppingand extraction eﬃciencies. For the short-lived 216 Th,
we were able to achieve ∼15% combined eﬃciency,
while for the extremely short-lived 217 Pa ∼12%.



As part of the SLOWRI project, we have begun development of a new low-energy experimental facility,
SlowSHE, for use with radioactive isotopes (RI), suchas Super Heavy Elements (SHE), that are created via
fusion-evaporation reactions. This new facility utilizes
a small gas cell1) placed after the GARIS-II separator
to thermalize the ions before they are transported toa multi-reﬂection time-of-ﬂight mass spectrograph2) .
A very thin mylar ﬁlm (2.4 µm thick) on a rotatable
frame is placed before the gas cell for use as an adjustable degrader to remove, in combination with twothin (1.1 µm and 2.4 µm thick) mylar windows, a large
fraction of the ions kinetic energy. The remaining
kinetic energy is removed by collisions with He gas,
which the cell is pressurized with upto 100 mbar.
In this ﬁrst experiment, we desired to verify the combined stopping and extraction eﬃciency for a varietyof chemical elements using isotopes with a wide rangeof half-lives. We ﬁrst studied stopping and extractionof the long-lived 205 Fr (T1/2 =3.8 s), produced via thereaction 169 Tm(40 Ar,4n)205 Fr.
The degrader was initially replaced with a large silicon detector array to measure the incoming rate. The
α-decay rate of 205 Fr was calibrated against the rateof elastically scattered incoming beam near the reaction target. The detector was then replaced by thedegrader and the rate of α-decay on a silicon detector
placed after the gas cell was measured as a function of
the degrader angle. The result, shown in Fig. 1, featured a ﬂat plateau with eﬃciency peaking near 30%.

RIKEN Nishina Center
Department of Physics, University of Tsukuba
Department of Chemistry and BioChemistry, New Mexico
State University- 22 -

These results were obtained with the gas cell operated at room temperature; we believe that using cryogenic temperatures should provide further improvements by reducing the possibility of charge exchangewith gas impurities and reducing the rate of diﬀusionof the ion cloud as it transits the length of the gas cell.
Even with the eﬃciencies reported herein, it should
be possible to perform precision mass measurements ofeven trans-Uranium isotopes with exceedingly low production rates. First such measurements are planned totake place within calendar year 2015.
References
1) F. Arai et al., this volume
2) P. Schury et al., Nuclear Instr. and Methods in Physics
Research B 335 (2014) 39-53

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

Electron scattering spectrometer for the SCRIT project
K. Tsukada,∗1,∗2 A. Enokizono,∗1,∗3 K. Kurita,∗1,∗3 S. Matsuo,∗1,∗3 Y. Moriya,∗1,∗2 T. Ohnishi,∗1 T. Suda,∗1,∗2
T. Tamae,∗1,∗2 M. Togasaki,∗1,∗3 T. Tsuru,∗1,∗2 R. Toba,∗1,∗4 K. Yamada,∗1,∗3 S. Yoneyama,∗1,∗2 andM. Wakasugi∗1
We have developed the magnetic spectrometer system1) , WiSES (Window-frame Spectrometer for Electron Scattering), for electron scattering on short-lived
nuclei at the SCRIT electron scattering facility. The
WiSES consists of a dipole magnet2,3) , FDC(Front
Drift Chamber), RDC(Rear Drift Chamber)4) , plastic scintillator hodoscope, and a helium bag. Figure 1
shows a schematic view of the WiSES and SCRIT system5) . The layer conﬁgulation of the drift chambers is
XX’XX’ for FDC and VV’UU’XX’VV’UU’ for RDC.
The gas of drift chambers are He+CH4 (50:50) at thistime. The combination of FDC and RDC enables reconstruction of the trajectory of electrons in the magnetic ﬁeld and estimation of the momentum. Our goalof momentum resolution is δp/p ∼ 1×10−3 for 300
MeV electron. The solid angle of the spectrometer isevaluated to be 83 msr by a simulation. The plastic
scintillator hodoscope is used to generate trigger signals. A detail of the data acquisition system is reported
elsewhere6) . The helium bag made of vinyl sheets ofthickness 30 µm is installed between FDC and RDC
to reduce the multiple scattering of electrons.
In December 2014, a commissioning experiment was
carried out to evaluate the performance of the WiSES
and the luminosity monitor system7) . A tungsten wireof diameter 50 µm was mounted in the SCRIT, andits position could be controlled remotely; this wire wasused as a target. Because the diﬀerential cross sectionof electron elastic scattering on the tungsten target
is well known, we can estimate the performance of thespectrometer by checking the reproducibility of the differential cross sections. In Fig. 2, preliminary results
for the electron beam energy at 150 MeV are shown.
Electrons elastically scattered from the tungsten wire
are found as a peak in the vertex point and momentum distribution, and their resolutions are evaluatedto be approximately 10 mm and 6×10−3 , respectively.
These resolutions will be improved by further analysis.
The obtained angular distribution is well reproduced
by a simulation in which the diﬀerential cross sectionof the elastic scattering on the tungsten target is estimated by a DWIA calculation.

Fig. 2. Preliminary results for the electron energy at 150
MeV. (a) Vertex point distribution along the beam line.
A clear peak of electrons scattered from the tungsten
wire can be seen. (b) Momentum distribution of electrons from the tungsten wire. A clear peak corresponding to the elastic scattering can be seen. (c) Polar angle
distribution of the elastically scattered electrons. The
red line shows the simulation using the diﬀerential crosssection estimated by a DWIA calculation.
Fig. 1. Schematic view of the WiSES. A trajectory between
FDC and RDC was reconstructed by a Runge-Kutta
calculation. The space between FDC and RDC was
ﬁlled with helium.
∗1
∗2
∗3
∗4

RIKEN Nishina Center
ELPH, Tohoku University
Department of Physics, Rikkyo University
Department of Electrical Engineering, Nagaoka Universityof Technology- 23 -

References
1) T. Adachi et al.: Accel. Prog. Rep. 45, 144 (2012)2) T. Suda et al.: Accel. Prog. Rep. 46, 184 (2013)3) T. Tamae et al.: Accel. Prog. Rep. 47, 196 (2014)4) S. Matsuo et al.: in this report.
5) M. Wakasugi et al.: Accel. Prog. Rep. 43, 1 (2010)6) A. Enokiozono et al.: in this report.
7) S. Yoneyama et al.: in this report.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEAR

Measurement of isochronism using α-source for the Rare RI Ring
Y. Abe,∗1,∗2 Y. Yamaguchi,∗1 M. Wakasugi,∗1 T. Uesaka,∗1 A. Ozawa,∗2
F. Suzaki,∗1,∗3 D. Nagae,∗2 H. Miura,∗3 and T. Yamaguchi∗3
Figure 2 shows the results of measurement and simulation by MOCADI.3) To evaluate the optimum gradientvalue, we ﬁtted the results with a parabolic function.
The obtained mean value of 0.207(2) is in very good
agreement with the simulation result of 0.205. Thisshows that our isochronous ﬁeld calculation was correct and an isochronous ﬁeld is formed using trim coils.
The ﬁnal observed width had 0.61 ns standard deviation. However, the width was limited by the timing
resolution of the detectors. Therefore, the achieved
isochronism of the ring was less than 1.3 × 10−4 .
3.5

standard deviation [ns]

The Rare RI Ring was constructed at the RIBF
to measure the masses of nuclei pertinent to the rprocess.1) We performed an oﬄine machine study using
α-source (241 Am). The α-source was placed in the ringon the central orbit at the R-MD1 area after the ﬁrst
sector as shown in Fig. 1. First, we tried transporting the α particle in the ring and succeeded. Next, toconﬁrm the isochronous ﬁeld of the ring, we measured
TOF after one revolution using two detectors. One wasa carbon foil detector like a circulation detector of thisring,2) and the other was a plastic scintillator. The
carbon foil detector consisted of thin carbon foil (60µg/cm2 thickness) and three wired plates. A schematic
view of these detectors is shown in Fig. 1. The carbon
foil detector was placed in front of the source, whereas
the plastic scintillator was placed behind the source todetect the α particle after one revolution. A delayed
signal from the carbon foil detector was used as a stop
signal of TOF, and a signal from the plastic scintillator
was used as a start signal.

Simulation
Measurement

3.0

Fitting

2.5
2.0
1.5

mean = 0.207(2)

1.0
0.5
0.0
0.16

0.17

0.18

0.19

0.20 0.21

0.22

0.23

0.24

0.25

(∂B/∂r)/B0
α-ray
R-MD1
(W+Au) wire
(φ 40 µm)

C-foil(60 µg/cm2)

Fig. 2. Results of measurement (closed circles) and comparison with simulation (dashed line). The solid line is
the result of ﬁtting with a parabolic function.

241Am

α-ray

eMCP

Plastic
scintillator

Fig. 1. Setup of α-source and detectors. The carbon foil
detector was placed in front of the α-source, whereas
the plastic scintillator was placed behind.

The obtained TOF was 4643.5(6) ns which corresponds to an α particle with 0.87 MeV/nucleon. This
energy is equivalent to the value calculated from energy loss by the cover of the source and the carbon
foil. In addtion we measured TOF while changing theradial gradient of the magnetic ﬁeld using 10 trim coils.
∗1
∗2
∗3

RIKEN Nishina Center
Institute of Physics, University of Tsukuba
Department of Physics, Saitama University- 24 -

It is seen from our results in Fig. 2 that the standard
deviation was saturated. This saturation was causedby the limitation of timing resolution of the detectors.
Currently, we are testing an injection system to store
the α particle from the source for several revolutions. If
we can measure the TOF after several revolutions, wewould be able to conﬁrm the isochronism with higher
order even though the timing resolution of the detectors is limited. Furthermore we will perform a machine
study using a heavy-ion beam in the next ﬁscal year.
References
1) Y. Yamaguchi et al.: RIKEN Accel. Prog. Rep. 46 xiv(2013)
2) Y. Abe et al.: JPS Conf. Proc. 1, 013059 (2014)3) N. Iwasa et al.: Nucl. Instrum. Methods B 126, 284(1997)

Ⅰ. HIGHLIGHTS OF THE YEARRIKEN Accel. Prog. Rep. 48 (2015)

Time-stamping system for nuclear physics experiments at RIKEN
RIBF†
H. Baba,∗1 T. Ichihara,∗1 T. Ohnishi,∗1 S. Takeuchi,∗1 K. Yoshida,∗1 Y. Watanabe,∗1 S. Ota,∗2 S. Shimoura,∗2
and K. Yoshinaga∗3
At the RIKEN RIBF, a new time-stamping system
has been developed for nuclear physics experiments.
The time-stamping function is implemented in a logic
unit for programmable operation (LUPO)1) . One of
the remarkable features is that it can attach the timestamp information to an existing CAMAC/VME based
DAQ system in RIBF2) . The timing resolution of thetime-stamping system is 10 ns, which is suﬃcient toﬁnd the event correlation between separated DAQ systems. This speciﬁcation enables us to merge obtained
data separately on an event-by-event basis after themeasurement.
The proposed time-stamping system was installed
at RIKEN RIBF for use in β-decay experiments3–6) .
In these experiments, a beam line detector set, a silicon detector array, and a germanium detector array
were used. Since the triggers for these detectors are
independent of each other, three separate DAQ systems were used. In this report, the results for the
DAQ systems for the beam line detector set (BeamDAQ) and the silicon detector array (SiDAQ) are described. The beam line detector set is triggered by
RI-beams, i.e., beam events. The silicon detector array is triggered by both implanted isotopes and β rays,i.e., beam events and β-decay events. For the silicondetector array, when both SiDAQ and BeamDAQ are
triggered at the same time, the event can be identiﬁed as a beam event. On the other hand, if SiDAQ istriggered but BeamDAQ is not, the event is a β-decay
event. In order to determine the relationship between
the number of actually generated physics events andthe number of events accepted by separate DAQ systems, the combined live time was investigated. An
additional DAQ system named full-event monitor was
installed to acquire the time stamps of all generated
triggers. By using LUPO, trigger time stamps for each
DAQ system are recorded without loss. BeamDAQ
and SiDAQ store detector data together with the timestamps of accepted triggers. In contrast, the full-event
monitor only accumulates time-stamp values of triggers generated for BeamDAQ and SiDAQ. The combined live times for beam events and β-decay eventsin the silicon detector array are determined as the ratio of the number of events identiﬁed using BeamDAQ
and SiDAQ and the number of triggers recorded by
†
∗1
∗2
∗3

Condensed from the article in Nucl. Instr. and Meth. A
777, 75 (2015)
RIKEN Nishina Center
Center for Nuclear Study, University of Tokyo
Tokyo University of Science- 25 -

Table 1. Event rates and combined live times for beam andβ decay events in the silicon detector array.
Beam events
Measured
Estimated

R (events/s)
87.5
87.3

PL (%)
94.0
94.0

β decay events
Measured
Estimated

R (events/s)
368369

PL (%)
95.3
95.3

the full-event monitor. Table 1 lists the measured andestimated combined live times for beam and β-decay
events in the silicon detector array. The real eventoccurrence rate (R) is unknown if the full-event monitor is not present. However, it is possible to estimate itby comparing the observed and simulated DAQ acceptance rates (Racc ) when a trigger is accepted by both
BeamDAQ and SiDAQ. Monte Carlo simulation was
performed in order to estimate DAQ acceptance rates
from a DAQ transaction time, which can be obtainedusing the scaler circuit in the experiment. The transaction times of BeamDAQ and SiDAQ were 210 and 108
μs, respectively. From the results of the Monte Carlosimulation, the assumed beam-event and β-decay event
rates (R) are calculated to ﬁt the observed DAQ acceptance rate (Racc = 82.2 events/s). These results
indicate that for beam and β-decay events, the accuracy of the Monte Carlo simulation was good. Within
this simulation, the systematic error in the simulated
event rates was 0.2%.
In summary, a time-stamping system has been introduced in the RIKEN RIBF. This system is particularly useful for β-decay experiments. Although the
combined live time for separate DAQ systems is notstraightforward to determine, it can be measured by installing a full-event monitor. It was found that Monte
Carlo simulations can estimate the true event rate witha high degree of accuracy.
References
1) H. Baba et al.: RIKEN Accel. Prog. Rep. 43, 222(2010).
2) H. Baba et al.: Nucl. Instr. Meth. A 616, 65 (2010).
3) H. Watanabe et al.: Phys. Lett. B 696, 186 (2011).
4) H. Watanabe et al.: Phys. Lett. B 704, 270 (2011).
5) S. Nishimura et al.: Phys. Rev. Lett. 106 052502 (2011).
6) T. Sumikama et al.: Phys. Rev. Lett. 106 202501(2011).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅰ. HIGHLIGHTS OF THE YEARFirst chemical synthesis and investigation of Sg(CO)6†
J. Even, *1 A. Yakushev,*2 Ch.E. Düllmann,*1,*2,*3 H. Haba,*4 M. Asai,*5 T.K. Sato,*5 H. Brand,*2 A. Di Nitto,*3 R. Eichler,*6,*7F.L. Fan,*8 W. Hartmann,*2 M. Huang,*4 E. Jäger,*2 D. Kaji,*4 J. Kanaya,*4 Y. Kaneya,*5 J. Khuyagbaatar,*1 B. Kindler,*2
J.V. Kratz,*3 J. Krier,*2 Y. Kudou,*4 N. Kurz,*2 B. Lommel,*2 S. Miyashita,*5, *9 K. Morimoto,*4 K. Morita,*4, *10
M. Murakami,*4,*11 Y. Nagame,*5 H. Nitsche,*12, *13 K. Ooe,*11 Z. Qin,*8 M. Schädel,*5 J. Steiner,*2 T. Sumita,*4 M. Takeyama,*4
K. Tanaka,*4 A. Toyoshima,*5 K. Tsukada,*5 A. Türler,* 6, *7 I. Usoltsev, *6, *7 Y. Wakabayashi,*4 Y. Wang,*8 N. Wiehl,*1, *3
S. Yamaki,*4, *14
Gas phase chemical studies of the superheavy elements
have been limited to simple inorganic compounds so far.1)
Due to challenging experimental conditions, access to othercompound classes was limited. With the combination ofphysical preseparation with gas-phase chemistry techniques,parts of the experimental limitations could be overcome.2-3)
We succeeded in the synthesis of the first carbonyl
complex of a superheavy element, namely seaborgium
hexacarbonyl (Sg(CO)6), at the GAs-filled Recoil Ion
Separator GARIS4). Sg(CO)6 has been predicted to bestable5) and its adsorption behavior on SiO2 surface is
expected to be very similar to that of W(CO)66). We
therefore investigated Sg(CO)6 along with W(CO)6.
Short-lived 164W, and ~10-s 265Sg were synthesized in thereactions 144Sm(24Mg,4n)164W and 248Cm(22Ne,5n)265Sg.
The evaporation residues (EVRs) were separated from theprimary beam and lighter transfer products within GARIS.
At the focal plane of GARIS, a recoil transfer chamber(RTC) was installed. The EVRs passed the entrance
window of the RTC and were thermalized in a He / COatmosphere (~600 mbar) in the RTC. The free single ions of
W and Sg reacted with CO, forming volatile complexes7).
The RTC was flushed continuously, transporting volatilecompounds through a 10-m long capillary to the Cryo
Online Multidetector for Physics and Chemistry of theTransactinides COMPACT8), a thermochromatography
detector array. The chromatography channel is formed by
32 pairs of silicon PIN diodes covered with a SiO2 surface,
kept at temperatures between 22 °C and -140°C. Volatilecompounds adsorb at a certain temperature on the detector
surface. The deposition pattern compared with Monte Carlo
Simulations MCS, which allowed determining theadsorption enthalpy -ΔHads. W as well as Sg were trans†

ported to COMPACT, hence, formed volatile compoundswith the CO. In total 15 decay chains assigned to the decayof 265Sg plus three uncorrelated fission event assigned tooriginate from members of the 265Sg decay chain wereobserved under almost background free conditions at a total
beam integral of 1.52∙1019. Both, the W as well as the Sg
complexes deposited mainly in the last third of the detector(see Fig. 1). The W chromatograms are in agreement withformer experiments reported in 3), where the transported
species was assigned to W(CO)6. The Sg species shows thesame adsorption behavior on SiO2 as W(CO)6, whichstrongly supports the assignment to Sg(CO) 6 7). The
experimental distribution and MCS are shown in Figure 1.

Fig. 1. Distribution of 164W (upper graph) and 265Sg(bottom graphic). 164W was measured at 1L/min; the lower
panel shows a combined chromatogram of all observed Sg
events (flow rates between 1 L/min and 2.2 L/min). The
black curve shows the result of the MCS (after [7]).

Condensed from the article in Even et al. Science 345, 1491 (2014).

*1

Helmholtz-Institut Mainz.
GSI Helmholtzzentrum für Schwerionenforschung GmbH.
*3
Johannes Gutenberg-Universität Mainz.
*4
Nishina Center for Accelerator-Based Science, RIKEN.
*5Advanced Science Research Center, JAEA.
*6
University of Berne.
*7
Paul Scherrer Institute.
*8
Institute of Modern Physics Lanzhou; Chinese Academy of Sciences.
*9
Hiroshima University.
*10
Kyushu University.
*11
Niigata University.
*12
University of California, Berkeley.
*13
Lawrence Berkeley National Laboratory,.
*14
Saitama University.

References*21) A. Türler and V. Pershina: Chem. Rev. 113, 1237 (2013).
2) Ch.E. Düllmann: Eur. Phys. J. D 45, 75 (2007).
3) J. Even et al.: Inorg. Chem. 51, 6431 (2012).
4) K. Morita et al.: Nucl. Instr. Meth. B 70, 220 (1992).
5) C.S. Nash, B.E. Bursten: J. Am. Chem. Soc. 121, 10830 (1999).
6) V. Pershina, J. Anton: J. Chem. Phys. 138, 174301–6 (2013).
7) J. Even et al. Science 345, 1491 (2014).
8) A. Yakushev et al., Inorg. Chem. 53, 1624 (2014).

- 26 -

II. RESEARCH ACTIVITIES I(Nuclear, Particle and Astro-Physics)

1. Nuclear Physics

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Long-lived isomer in 126 Pd†
H. Watanabe∗1,∗2 for the RIBF60&62R1 Collaboration

†
∗1
∗2

Condensed from the article in Phys. Rev. Lett. 113, 042502(2014)RIKEN Nishina Center
IRCNPC, School of Physics and Nuclear Energy Engineering, Beihang University- 27 -

are populated through the β decay of the long-lived
isomer in 126 Pd. Therefore, the half-life is determined
to be 23.0(8) ms by taking a weighted average of therespective values. Based on the observed mutual coincidence [see Fig. 2(d)] and γ-ray intensities, we propose
the decay scheme from the long-lived isomer in 126 Pd
to the high-spin states in 126 Ag as shown in Fig. 1.
(10+ )

296.7
86.2

(7− )
(5− )
(4+ )

2406 23.0(8) ms

β2110 0.44(3) µs
2023 0.33(4) µs(2121+x)

542.4
1481
1330.2
787.7

(2+ )

359.5
227.9

0+

(1762+x)(1534+x)

741.8

693

(792+x)

693.3

598.1

0 48.6(8) ms

193.7

126
46 Pd 80

194+x
x

126
47 Ag 79

20
542.4
10
0
8

(c)

4
2

8

(d)

193.7
227.9

6

300
1502.0Eγ [keV]1330.2914.7

1132.8250

400 I II
300
200
× 10
100
0
0 400 800 1200 1600
Eelectron [keV]

693.3
787.7

1330.210297keV:
1 693keV:
T1/2=21(2)ms
T1/2=20(3)ms
0.10 20 40 60 80 100 120 0 20 40 60 80 100 120
Time [ms]542.4
1330.2
787.7

296.7

6

0

0

Counts /
8 keV

296.7

(b)

Counts /
1 keV

40

741.8

359.5

4

193keV:T1/2=25(2)ms
100
101
742keV:T1/2=23(2)ms
0.1
0 20 40 60 80 100 120
Time [ms]Counts /16 msCounts / 1 keV

30

287.0
254.3
296.7
263.2

80

542.4
583.5
598.1
661.9
693.3
741.8
787.7
842.6

50

0

Counts / 2 keV(a)Counts /16 msCounts / 1 keV

100

193.7
227.9 203.7
263.2
287.0
296.7
359.5
365.0

Fig. 1. Decay schemes of the J π = (10+ ) isomer in 126 Pd.

Counts / 2 keVSpectroscopic studies of 126 Pd have been performedat the RIBF facility. Neutron-rich nuclei below 132 Sn
were produced using in-flight fission of a 238 U86+ beamat 345 MeV/nucleon with the intensity ranging from
7 to 12 pnA, impinging on a beryllium target with athickness of 3 mm. The nuclei of interest were separated and identified through the BigRIPS separator
and the following ZeroDegree spectrometer. A totalof 5.3 × 104 126 Pd fragments were implanted into ahighly segmented active stopper, named WAS3ABi,
which consisted of eight double-sided silicon-strip detectors (DSSSD) stacked compactly. The DSSSDs also
served as detectors for electrons following β-decay andinternal conversion (IC) processes. Gamma rays weredetected by the EURICA array that consisted of twelve
Cluster-type detectors.
The decay schemes of the isomeric states in 126 Pd
are exhibited in Fig. 1. For 126 Pd, the J π = (5− ) and(7− ) isomers at 2023 and 2110 keV, respectively, werereported in Ref.1) . In the present work, the γ rays
below these isomers, except for the 86-keV line, havebeen also observed in coincidence with electrons thatwere associated with the prior implantation of 126 Pd,
as demonstrated in Fig. 2(a). With gates on these γrays, a prominent peak can be found in an electron
spectrum [marked with ”I” in the inset of Fig. 2(b)];this corresponds to the conversion electrons for the 86keV, E2 transition (αT = 2.374). In Fig. 2(b), a γray at 297 keV is clearly visible in addition to the γrays below the (5− ) isomer by gating on the 86-keV
IC peak. The appearance of the 297-keV peak is emphasized by taking a γ-ray time condition earlier thanelectron events, as is evident from the inset of Fig. 2(a),suggesting that this new γ ray precedes the highly converted 86-keV transition. Furthermore, the 297-keV γ
ray is observed in coincidence with the other γ rays in126
Pd [see Fig. 2(c) as an example]. Thus, the longlived isomer can be identified at an excitation energyof 2406 keV. A peak marked with ”II” in the inset of
Fig. 2(b) is expected to arise from the conversion electrons for the 297-keV transition, being most likely ofan E3 character (αT = 0.1197).
The half-life (T1/2 ) derived from the time distribution of the 297-keV γ ray is in agreement with that of
the 693-keV one within experimental errors, as illustrated in the insets of Fig. 2(c). Similar half-lives havebeen observed for six other γ rays; these transitions are
expected to belong to high-spin states in 126 Ag which

2
0

200

400

600

800
Eγ [keV]

1000

1200

1400

Fig. 2. Gamma-ray spectra measured with various gateconditions within 50 ms after the 126 Pd implantation.

References
1) H. Watanabe et al.: Phys. Rev. Lett. 111, 152501(2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Yrast 6+ Seniority Isomers of 136,138Sn††

Condensed from the article in Phys. Rev. Lett. 113, 132502(2014)∗1 University of the West of Scotland∗2 SUPA∗3 LPSC, UJF, CNRS, INPG
∗4 Institut Laue-Langevin∗5 RIKEN Nishina Center∗6 IEM, CSIC
∗7 UAM∗8 IPHC∗9 Department of Physics, Tohoku University∗10 Department of Physics, University of Tokyo- 28 -

4

50

2

40

+

30
20

B(E2;6 -> 4 ) (e fm )The shell model plays a key role in allowing a microscopic description of many of the properties of atomic
nuclei. Its two ingredients are single-particle energies and effective nucleon-nucleon interactions. Experimental studies of semi-magic Sn nuclei beyond the
doubly magic nucleus 132 Sn provide information thatallows the neutron-neutron part of effective interactions for the N = 82 − 126 valence space to be tested
and optimized. More generally, such studies provide
a key benchmark for the methods used to constructeffective interactions in a heavy-mass region far fromstability. Currently there is little experimental dataon the Sn isotopes beyond the N = 82 shell closure,which are difficult to produce and study.
Excited states in the nuclei 136,138 Sn have been investigated by detecting delayed γ-ray cascades using
the EURICA spectrometer1) , which was coupled to
the BigRIPS separator of the RIBF facility. These
exotic nuclei were produced by the in-flight fission of
a 345 MeV/nucleon 238 U beam. Cascades containing
three delayed γ rays each were observed in coincidencewith identified 136,138 Sn ions. The spins of the isomericstates of 136,138 Sn were assigned as (6+ ), in analogy
with a very similar delayed cascade previously reported
for 134 Sn2) .
The energies of the excited states of 134,136,138 Sn
have been compared to the predictions of shell-model
calculations, which used state-of-the-art realistic effective interactions. These calculations used the fullN = 82 − 126 valence space and the effective singleparticle energies were the experimental ones. The experimentally determined level energies of 134,136,138 Sn+
were all well reproduced. The B(E2; 6+
1 → 41 ) values
were also correctly predicted for 134,138 Sn, though thisvalue was more than a factor of 5 away for 136 Sn, as
shown in Fig. 1. Three other shell-model calculations
reported in the literature, using realistic and empirical effective interactions, also failed to reproduce the+136
B(E2; 6+
Sn and are off by at least
1 → 41 ) value fora factor of 2.

+

G.S. Simpson,∗1,∗2,∗3 G. Gey,∗3,∗4,∗5 A. Jungclaus,∗6 J. Taprogge,∗6,∗7,∗5 S. Nishimura,∗5 K. Sieja,∗8
P. Doornenbal,∗5 G. Lorusso,∗5 H. Sakurai,∗5,∗10 P.-A. Söderström,∗5 T. Sumikama,∗9 Z.Y. Xu,∗10
on behalf of the RIBF-85 collaboration
Exp.
Seniority
Vlowk
Vlowk+mod

10
0

134

136

138

A

Fig. 1. Experimental (black squares) and theoretical re+134−138
Sn.
duced transition rates for 6+
1 →41 γ decays in
The calculations used a realistic Vlow−k interaction(red filled circles), a pairing-modified Vlow−k interaction (blue open circles) and a pure f7/2 seniority scheme(grey curve).

+
The near-constant energies of the (2+1 ), (41 ) and+
134,136,138(61 ) states ofSn are characteristic of dom-

inant seniority 2 (one broken pair) excitations. The
B(E2) values of seniority-conserving transitions are
expected to follow the shape of a symmetric positive
parabola, as shown in Fig. 1. The results obtained witha realistic Vlow−k interaction follow a similar pattern
to the seniority 2 scheme. Additional shell-model calculations have been performed which allowed particlehole excitations from the neutron ν0h11/2 and proton
0g9/2 shells to the N = 82 − 126 and Z = 50 − 70
valence spaces, respectively. These allowed the influence of core polarization effects on the transition ratesof the neutron-rich Sn nuclei to be examined. How+136
ever, the B(E2; 6+
Sn was still
1 → 41 ) value for
not correctly reproduced. Reducing the energies of2the ν1f7/2
diagonal and off-diagonal matrix elements+136
by ∼150 keV allowed the B(E2, 6+
Sn
1 → 41 ) of
to be correctly predicted. This shift is equivalent toa reduction in the pairing strength. The results using
this pairing-modified Vlow−k interaction are shown in
Fig. 1. Similar modifications to pairing were necessary
to reproduce the level schemes of 72,74 Ni4) , illustrating the need for additional theoretical efforts on theconstruction of effective interactions.
References
1) P.A. Soderström, et al.: Nucl. Instr. Meth. B 317, 649(2013).
2) A. Korgul, et al.: Eur. Phys. J. A 7, 167 (2000).
3) A. Covello, et al.: J. Phys. Conf. Ser. 267, 012019(2011).
4) H. Grawe, et al.: Nucl. Phys. A704, 211 (2002).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Gamma-Spectroscopy around 100 Sn
D. Lubos,∗1,∗2 J. Park,∗3 M. Lewitowicz,∗4 R. Gernhäuser,∗1 R. Krücken,∗3 S. Nishimura,∗2 H. Sakurai,∗5
H. Baba,∗2 B. Blank,∗6 A. Blazhev,∗7 P. Boutachkov,∗8 F. Browne,∗9,∗2 I. Celikovic,∗4 P. Doornenbal,∗2
T. Faestermann,∗1 Y. Fang,∗10,∗2 G. de France,∗3 N. Goel,∗8 M. Gorska,∗8 S. Ilieva,∗11 T. Isobe,∗2
A. Jungclaus,∗12 G. D. Kim,∗13 Y.-K. Kim,∗13 I. Kojouharov,∗8 M. Kowalska,∗14 N. Kurz,∗8 Z. Li,∗15
G. Lorusso,∗2 K. Moschner,∗7 I. Nishizuka,∗16,∗2 Z. Patel,∗17,∗2 M. M. Rajabali,∗3 S. Rice,∗17,∗2 H. Schaffner,∗8
L. Sinclair,∗18,∗2 P.-A. Söderström,∗2 K. Steiger,∗1 T. Sumikama,∗16 H. Watanabe,∗19 Z. Wang,∗3 J. Wu,∗12,∗2
and Z. Y. Xu∗5,∗2∗1

Physik Department E12, Technische Universität München
RIKEN Nishina Center∗3 TRIUMF∗4 GANIL∗5 Department of Physics, University of Tokyo∗6 CENBG∗7 Institut für Kernphysik, Universität zu Köln∗8 GSI Darmstadt∗9 School of Comp., Eng. and Maths., Brighton University∗10 Department of Physics, Osaka University∗11 Institut für Kernphysik, TU Darmstadt∗12 IES CSIS
∗13 Institute for Basic Science∗14 CERN∗15 School of Physics, Peking University∗16 Department of Physics, Tohoku University∗17 Department of Physics, Surrey University∗18 Department of Physics, University of York
∗19 Department of Physics, Beihang University∗2

uncertainties that is usually introduced by simulation
based methods. Efficiency calibrations, consistent with

Absolute γ -ray efficiency

An experiment for studying the superallowed
Gamow-Teller decay of the doubly magic nucleus 100 Sn
was performed in June 2013 at the high-resolution separator BigRIPS of the RIBF at the RIKEN Nishina
Center. A 4-mm 9 Be target was bombarded with a124
Xe beam of 345 MeV/u at intensities up to 36.4 pnA
to produce 100 Sn and a large cocktail3) of its neighboring nuclei down to neutron numbers N = (Z - 2) byfragmentation. The nuclei were implanted into the
WAS3ABi silicon detector that consists of 3 detectors with high granularity extended by 10 additional
single-sided, seven-fold segmented detectors in a closed
stack geometry to absorb the emitted β-particles at a
maximum efficiency. This WAS3ABi detector was surrounded by 84 Ge- and 18 LaBr-detectors of the 4π-γray spectrometer EURICA.
In order to study the branching ratios of the β-decays,
derive level schemes of exotic nuclei and determine isomeric ratios as well as lifetimes of the isomers, a reliable efficiency calibration has been performed.
Owing to the special geometry of the WAS3ABi andthe failure of several Ge-detectors, the calibration was
performed using a γγ-coincidence method. Cascading
γ-transitions in 98 Cd, 94 Pd and 96 Pd, fed by different
isomers, are available with a large number of counts.
For example the delayed γ-emission in 98 Cd always
contains a complete chain for the energies 147 keV,
198 keV, 687 keV and 1395 keV. Thus, the ratio of
coincident events of a pair of transitions and the total
number of events for one of them directly yields theefficiency at the corresponding energy. This method isof great advantage since the radiation, originating in
the implantation region, contains the detector-specificabsorption effects and it does not introduce systematic

0.14

Addback
No addback

0.12

0.1

0.08

0.06

0.04

0.02

0

200

400

600

800

1000

1200

1400
Energy / keV

Fig. 1. Absolute γ-ray efficiency of the HPGe clusters of
EURICA. γ-rays from isomers of 98 Cd, 96 Pd and 94 Pd,
are used for the fit. Bars indicate the statistical uncertainty of the efficiencies.

previous works4) , using this γγ-coincidence method areshown in Fig. 1.
In addition, greater precision of known isomer halflives was attainable owing to high statistics in thisexperiment and preliminary half-lives of 8+ and 12+
isomers in 98 Cd were determined as 181+35−25 ns and+5
228−5 ns, respectively. This would lead to better constraints on the transition strengths for the test of modern shell models. Previously reported γ-rays in the
β-decay of 100 Sn1) were reproduced, allowing an unprecedented βγγ-coincidence analysis for 100 In. Moreover a new high-spin isomeric state in 96 Cd has been
observed with a half-life of about 200 ns, with a decaybranch into both, the 16+ isomer and the (10+ ) state,
which has a prompt decay cascade to the ground state.
Further analysis is underway to finalize experimental
results and compare these to large-scale shell model
calculations.
References
1) C. Hinke et al.: Nature, 486, 341 (2012).
2) B. S. Nara Singh et al.: Phys. Rev. Lett. 107, 172502(2011).
3) D. Lubos, RIKEN Accel. Prog. Rep.: 47 (2014)4) K. Steiger: PhD thesis TU München (2010)- 29 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Identification of a millisecond isomeric state 129 Cd via the detectionof internal conversion and Compton electrons†
J. Taprogge,∗1,∗2,∗3 A. Jungclaus,∗1 H. Grawe,∗4 S. Nishimura,∗2 P. Doornenbal,∗2 G. Lorusso,∗2 E. Nácher,∗1
G.S. Simpson,∗5 P.-A. Söderström,∗2 T. Sumikama,∗6 Z.Y. Xu,∗7 H. Sakurai,∗2,∗7 H.Watanabe,2 on behalf of the
RIBF-85 and RIBF-60&62R1 collaborations
Isomeric states near nuclear shell closures are a sensitive probe to study the position of single-particle orbitals and their evolution. In the present work wehave studied for the ﬁrst time excited states in 129 Cd
which decay via the emission of γ rays. The neutronrich 129 Cd ions were produced at the Radioactive Isotope Beam Factory (RIBF), identiﬁed and separated
in BigRIPS and then implanted in the active stopper
WAS3ABi, consisting of eight closely packed DSSSD,
which is surrounded by the germanium array EURICA.

counts per 4 keV

300
200

100

400

800
1200
Energy [keV]

1600
T1/2 = 3.6(2) ms

Fig. 1. Energy spectrum of the Si detector in which the129
Cd ions were implanted for all decays observed in
the first 10 ms (black) and from 30 to 40 ms (red) after
the implantation.

27/27/2+

15/2-

5/2+

†
∗1
∗2
∗3
∗4
∗5
∗6
∗7

Condensed from the article in Phys. Lett. B, Vol. 738, 223(2014)
Instituto de Estructura de la Materia, CSICRIKEN Nishina Center
Departamento de Fı́sica Teórica, Uni. Autónoma de Madrid
GSI Helmholtzzentrum für Schwerionenforschung GmbH
LPSC, UJF, CNRS, INPG, Grenoble
Department of Physics, Tohoku University
Department of Physics, University of Tokyo- 30 -

406 keV
(M1)

13/2-

1/2+
3/2+

Two types of events were recorded by the data acquisition system, the implantation of the ions into theactive stopper WAS3ABi and their subsequent decays.
In the decay of 129 Cd a very short-lived component
in the range of a few milliseconds was observed, much
shorter than the previously reported half-lives of thetwo β-decaying states in 129 Cd1) . The inspection of theenergy spectrum of the Si detector in which the 129 Cdions were implanted for all decays observed in the ﬁrst
10 ms after the implantation (see black curve in Fig. 1 )revealed a peak structure at about 340 keV and an excess of counts below 250 keV. Those structures are notvisible for decays occurring in the time interval of 30 to
40 ms after the implantation for which the smooth energy distribution expected for β decays is observed (red353 keV (E3)21/2+1587 keV

01181 keV0curve) in Fig. 1. A comparison to Monte-Carlo simulations indicated that conversion electrons and Compton electrons from transitions following the decay ofa ms isomeric state in 129 Cd lead to the registrationof decay events in the active stopper. The energies ofsubsequent X-rays are summed with a certain chance
to the energy of the Compton electron which shifts thepeak to about 340 keV. Four transitions with energies
of 353, 406, 1181 and 1587 keV were observed in delayed coincidence with the implanted 129 Cd ions andthe half-life of the new isomeric state was determined
to T1/2 =3.6(2) ms from the summed time diﬀerence
distributions between the observed decay events andthe observation of either the 406- or 1181-keV γ rays.
Furthermore, the measured intensities of both γ rays
and conversion electrons were used to tentatively assign an E3 multipolarity to the primary isomeric transition with an energy of 353 keV.

NA-14

11/2-

EXP

Fig. 2. Proposed decay scheme and comparison to the shellmodel calculations NA-14.

The deduced decay scheme is compared to shellmodel calculations employing state-of-the-art realistic
interactions (NA-14, same as in Ref.2) ) in Fig. 2. The
dashed lines represent the predicted positions of lowlying positive parity states as well as states with positive and negative parity in the spin range 17/2 − 23/2.
None of these states is predicted to be isomeric. Basedon this comparison the new state was assigned to havespin and parity (21/2+ ). The experimentally determined reduced transition strength of B(E3) = 0.50(3)W.u. for the (21/2+ ) → (15/2− ) E3 transition is inperfect agreement with the value predicted by the SM
calculations, B(E3) = 0.48 W.u..
References
1) O. Arndt et al., Acta Physics Polonica B 40, 437 (2009)2) J. Taprogge et. al., Phys. Rev. Lett. 112, 132501 (2014).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Study of shape evolution in neutron-rich Cs isotopes
using β-decay spectroscopy
A. Yagi,∗1,∗2 A. Odahara,∗1 R. Daido,∗1,∗2 Y. Fang,∗1,∗2 H. Nishibata,∗1,∗2 R. Lozeva,∗3 C.-B. Moon,∗4
S. Nishimura,∗2 P. Doornenbal,∗2 G. Lorusso,∗2 P.-A. Söderström,∗2 T. Sumikama,∗5 H. Watanabe,∗6
T. Isobe,∗2 H. Baba,∗2 H. Sakurai,∗7,∗2 F. Browne,∗8,∗2 Z. Patel,∗9,∗2 S. Rice,∗9,∗2 L. Sinclair,∗10,∗2
J. Wu,∗11,∗2 Z.Y. Xu,∗12 R. Yokoyama,∗13 T. Kubo,∗2 N. Inabe,∗2 H. Suzuki,∗2 N. Fukuda,∗2
D. Kameda,∗2 H. Takeda,∗2 D.S. Ahn,∗2 D. Murai,∗14 F.L. Bello Garrote,∗15 J.M. Daugas,∗16
F. Didierjean,∗3 E. Ideguchi,∗17 T. Ishigaki,∗1,∗2 H.S. Jung,∗18 T. Komatsubara,∗19 Y.K. Kwon,∗19
C.S. Lee,∗20 P. Lee,∗20 S. Morimoto,∗1,∗2 M. Niikura,∗7,∗2 I. Nishizuka,∗5 T. Shimoda,∗1 and K. Tshoo∗19
10105

5

10104

4

143Xe54+

145Xe54+ 146

Xe54+

144Xe54+

147Xe54+10103

3CountsShape evolution in neutron-rich nuclei with the neutron number N >82 and the proton number Z>50 beyond the doubly magic 132 Sn nucleus have been investigated along several isotopic chains. The EURICA project1) provides us with an opportunity to
study extremely neutron-rich nuclei using β-decay andisomer-decay spectroscopy. We reported the results of
the isomer-search experiment for neutron-rich Cs isotopes2) , where new isomers were found in 145 Cs, 146 Cs,
147
Cs, and 148 Cs. To understand the nuclear structureof these neutron-rich Cs isotopes in the low-spin states,
we studied the β decay of neutron-rich Xe to Cs isotopes.
The neutron-rich Xe isotopes were produced throughin-ﬂight ﬁssion reaction using a 345-MeV/nucleon 238 U
beam. Particle identiﬁcation was performed using the
mass-to-charge ratio (A/Q) and the atomic number
deduced from the information of time-of-ﬂight (TOF),
magnetic rigidity (Bρ) and energy loss of ﬁssion fragments through BigRIPS and ZeroDegree Spectrometer3) . The isotopes were implanted into a stack ofﬁve double-sided Si-strip detectors (WAS3ABi)1) . β
rays emitted from the isotopes were also detected by
WAS3ABi. The parent nuclei of the β decay were identiﬁed by position correlation on the WAS3ABi between
the implanted fragments and the detected β rays. γ
rays emitted after the β decay were detected by the
γ-ray detector array which is called EURICA1) .

10102

2

142Xe53+ 143Xe53+ 144 53+
Xe

1010
1 1
2.65

2.66

2.67

2.68

2.69

2.7

2.71

2.72

2.65 2.66 2.67 2.68 2.69 2.70 2.71 2.72

A/Q

Fig. 1. A/Q spectrum of neutron-rich Xe isotopes.

Figure 1 shows a spectrum of particle identiﬁcation
for the Xe (Z = 54 ) isotopes as a function of A/Q.
The fully-stripped A Xe54+ ions are separated from thehydrogen-like A−3 Xe53+ ones owing to the high A/Q
resolution.
Coincidence data of β-γ and β-γ-γ with particle
identiﬁcation of 143 Xe, 144 Xe, 145 Xe, 146 Xe, and 147 Xe
isotopes is analyzed. As an example, the γ-ray energy
spectrum and the decay curve for the β decay of 145 Xe
to 145 Cs are shown in Fig. 2. We found 11 new γ rays
associated to the transitions in 145 Cs emitted after theβ decay of 145 Xe. These γ-ray peaks are represented asfull circles in Fig. 2. Other peaks are mostly assigned
to transitions in the granddaughter 145 Ba nucleus. The
inset in Fig. 2 shows the decay curve deduced by thetime diﬀerence between the implantation of 145 Xe andthe detection of the β rays gated on newly found 5
γ rays in 145 Cs. The half-life of the β decay was determined to be 197(10) ms, which is consistent withthe reported one in Ref. 4. Detailed analyses are in
progress.
matrix∗1

Department of Physics, Osaka University
RIKEN Nishina Center∗3 IPHC/CNRS and University of Strasbourg∗4 Department of Display Engineering, Hoseo University∗5 Department of Physics, Tohoku University∗6 Department of Physics, Beihang University∗7 Department of Physics, University of Tokyo∗8 CEM, University of Brighton∗9 Department of Physics, University of Surry∗10 Department of Physics, University of York∗11 Department of Physics, Peking University∗12 Hong Kong University∗13 CNS, University of Tokyo∗14 Department of Physics, Rikkyo University∗15 Department of Physics, University of Oslo
∗16 CEA/DAM∗17 RCNP, Osaka University∗18 Department of Physics, University of Notre Dame
∗19 IBS∗20 Department of Physics, Chung-Ang University

matrixpy
Entries

797

Mean 280.8
RMS 239.5

∗2

600
600

200

Counts500
500

CountsT1/2 = 197 (10) [ms]

200

400
400

150

150

100

100

50

50

300

0

300

200
200

0

0
0

200 400 600 800 1000
Time[ms]
200

400

600

800

1000

100
100

00
0

100
100

200
200

300
300

400
400

Energy[keV]

500
500

600
600

700
700

Fig. 2. γ-ray energy spectrum and decay curve of the βdecay of 145 Xe to 145 Cs.

References
1) S. Nishimura et al.: Prog. Theor. Exp. Phys. 2012,
03C006 (2012).
2) A. Yagi et al.: RIKEN Accel. Prog. Rep. 47, 3 (2014).
3) N. Fukuda et al.: Nucl. Instrum. Methods Phys. Res. B
317, 323 (2013).
4) U.C. Bergmann et al.: Nucl. Phys. A714, 21 (2003).

- 31 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Shell evolution in neutron-rich Te isotopes beyond
doubly magic 132Sn∗1

Department of Physics, Chung-Ang University
Department of Display Engineering, Hoseo University∗3 Department of Physics, Osaka University∗4 IPHC/CNRS and University of Strasbourg∗5 RIKEN Nishina Center∗6 RISP, Institute for Basic Science∗7 Department of Physics, Tohoku University∗8 Department of Physics, Tokyo University∗9 School of computing engineering and mathematics, University of Brighton∗10 Department of Physics, University of Surrey∗11 Department of Physics, University of York∗12 School of Physics, Peking University∗13 CNS, University of Tokyo∗14 Department of Physics, Rikkyo University∗15 Department of Physics, University of Oslo
∗16 CEA/DAM∗17 RCNP, Osaka University∗18 Department of Physics, University of Notre Dame
∗19 Department of Nuclear Engineering, Hanyang University∗20 Department of Physics, Beihang University∗2- 32 -

80
Count / /100
Counts100msecms

70

Count //keV
CountskeVWithin the context of the shell model, the nuclear
structure is understood in terms of the shell orbital
excitation across a large shell gap. In particular, theneutron-rich nuclei with a few valence nucleons at andnear the doubly magic nuclei such as 132 Sn always attract attention for testing the various nuclear models
in view of the rapidly changing nuclear structure withneutron numbers1–3) . In this respect, Sb and Te isotopes, with one and two protons outside the Z=50 proton shell closure respectively, form an interesting setof nuclei to study the evolution of the nuclear structure beyond the Z=50 and N =82 shell closures. This
work aims at determining the internal structures of
the neutron-rich Sb and Te nuclei and observing the
intrinsic nature of the nuclei such as isomerism, shapetransition, and dynamic or static deformation.
The nuclei to be investigated were produced andisotope-separated with BigRIPS at the RIBF facilityby the in-flight fission of a 238 U beam on a 9 Be production target at 345 MeV/nucleon. Measurements
were focused on identification of E(2+ ) and/or E(4+ )in even-even 138−140 Te for investigating the 132 Sn coreshell evolution and search for level scheme in the nuclei of interest to study the single-particle and collective features based on the β-decay level scheme. Particle identification was made by BigRIPS on the basisof the Bρ-∆E-TOF method4) . Further, subsequent β
decays from the reaction products were detected after(4 +(2 + )(
2+
)
)
(0 +
)

P. Lee,∗1 C.S. Lee,∗1 C.-B. Moon,∗2 A. Odahara,∗3 R. Lozeva,∗4 A. Yagi,∗3,∗5 D.S. Ahn,∗5 H. Baba,∗5
F.L. Bello Garrote,∗15 F. Browne,∗9 R. Daido,∗3,∗5 J.M. Daugas,∗5,∗16 F. Didierjean, ∗4 P. Doornenbal,∗5
Y. Fang,∗3 N. Fukuda,∗5 E. Ideguchi, ∗17 N. Inabe,∗5 T. Ishigaki,∗3,∗5 T. Isobe,∗5 H.S. Jung, ∗5,∗18 D. Kameda,∗5
Y.K. Kim,∗6,∗19 T. Komatsubara,∗6 T. Kubo,∗5 Y.K. Kwon,∗6 G. Lorusso,∗5 S. Morimoto,∗3,∗5 D. Murai,∗5,∗14
M. Niikura,∗5,∗8 H. Nishibata,∗3,∗5 S. Nishimura,∗5 I. Nishizuka,∗5,∗7 Z. Patel,∗10 S. Rice,∗10 H. Sakurai,∗5,∗8
T. Shimoda,∗3 L. Sinclair,∗11 P.-A. Söderström,∗5 T. Sumikama,∗5,∗7 H. Suzuki,∗5 H. Takeda,∗5 K. Tshoo,∗6
H. Watanabe,∗5,∗20 J. Wu,∗5,∗12 Z.Y. Xu, ∗8 and R. Yokoyama ∗13
T1/2 = 356 (34) ms

10

60
50
40
30

1

0

0.5

20

1

1.5

Time (s)

2

2.5

3

*

10
0

100

200

300

400

500

EnergyEnergy (keV)
(keV)

600

*
700

800

Fig. 1. Energy spectrum for β-delayed γ-decay associatedwith 138 Sb obtained by coincidence gates on lower transitions in 138 Te. Spectral lines marked by asterisks are
newly identified γ rays in this work. The inset shows adecay curve for the β-decay of 138 Sb.

the Sb secondary beam was implanted into the active
stopper, WAS3 ABi5) with the EURICA array in its
stopped-beam configuration6).
In the present experiment, we observed, for the firsttime, the β-delayed γ decay for 138 Sb as an example
in Fig. 1. The deduced β-decay half-life for 138 Sb
agrees well with previously reported value7) , while thehalf-life of 140 Sb needs more careful analysis to draw
a conclusion. We found two new excited states above
the known (4+ ) state in 138 Te and one candidate excited state in 140 Te. We expect that this newly found
spectroscopic information on excited states will provide crucial information on shell evolution of neutronrich Te isotopes and pairing interaction around N =82
shell closure. Further analysis is in progress.
References
1) D. Radford et al.: Phys. Rev. Lett. 88 222501 (2002).
2) J. Terasaki et al.: Phys. Rev. C 66 054313 (2002).
3) F. Hoellinger et al.: Eur. Phys. J. A 6 375 (1999).
4) N. Fukuda et al.: Nucl. Instr. Meth. B 317 323 (2013).
5) S. Nishimura: Prog. Theor. Exp. Phys. 2001 03C006(2012).
6) P.-A. Söderström et al.: Nucl. Instr. Meth. Phys. B 317
649 (2013).
7) O. Arndt et al.: Phys. Rev. C 84 061307(R) (2011).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Decay spectroscopy of neutron-rich Z ≈ 60 isotopes
E. Ideguchi,∗1 Mn. Tanaka,∗1 R. Yokoyama,∗3 G. S. Simpson,∗2 S. Nishimura,∗4 P. Doornenbal,∗4
P.-A. Söderström,∗4 G. Lorusso,∗4 Z. Xu,∗5 J. Wu,∗4,6 T. Sumikama,∗7 N. Aoi,∗1 H. Baba,∗4 F. Bello,∗8
F. Browne,∗4,9 R. Daido,∗10 Y. Fang,∗10 N. Fukuda,∗4 G. Gey,∗2,4,11 S. Go,∗3,4 N. Inabe,∗4 T. Isobe,∗4
D. Kameda,∗4 K. Kobayashi,∗12 M. Kobayashi,∗3 T. Komatsubara,∗13 T. Kubo,∗4 I. Kuti,∗14 Z. Li,∗6
M. Matsushita,∗3 S. Michimasa,∗3 C.-B. Moon,∗15 H. Nishibata,∗10 I. Nishizuka,∗7 A. Odahara,∗10 Z. Patel,∗4,16
S. Rice,∗4,16 E. Sahin,∗8 L. Sinclair,∗4,17 H. Suzuki,∗4 H. Takeda,∗4 J. Taprogge,∗18,19 Zs. Vajta,∗14
H. Watanabe,∗20 and A. Yagi∗10
The neutron-rich A∼150 region contains a wide variety of shape phenomena, including shape coexistence
and possible static octupole and hexadecapole deformations. After the systematic studies of the excitedlevels of these isotopes, it was found that the nuclei
beyond N = 90 or 92 in this region show characteristics
of strong quadrupole deformation, such as low-energy
2+ levels and the energy ratio of 4+ to 2+ levels ofnearly 3.3. In addition, K isomers were systematicallyobserved,1) which indicates stable axial-symmetric deformation because K is a good quantum number insuch nuclei and large ∆K transitions are strongly hindered.
In our studies of neutron-rich Nd isotopes throughisomer spectroscopy using the EURICA spectrometer,2) K isomers were systematically observed up to
N = 100.3) Gamma rays decaying from the isomer andthose of ground-state rotational bands in low-lying levels were observed. The trend of decreasing 4+ → 2+
transition energy with increasing neutron number may
indicate the development of quadrupole deformation in
neutron-rich Nd isotopes.
Such development of deformation will reﬂect in the
conﬁguration of the ground state, and therefore, thespin and parity of neighboring odd and odd-odd nuclei
will be useful for understanding the deformed structure. This can be investigated through β-γ spectroscopy.
In order to study the β decay of neutron-rich Pr isotopes, which are parent nuclei of the Nd isotope, β-γ

spectroscopic measurement was performed at RIBF.
The in-ﬂight ﬁssion of 238 U at 345 MeV/u was employed to produce neutron-rich Pr isotopes and theirneighbors. Nuclei of interest were selected and transported to the ﬁnal focal plane, F11, using the BigRIPS
fragment separator. These isotopes were stopped at
the active stopper, WAS3ABi,4) and β-γ spectroscopyof these isotopes was performed using the EURICA
setup at F11.
Figure 1 shows a γ-ray energy spectrum after the βdecay of 156 Pr. Gamma peaks at 67 and 155 keV are
clearly identiﬁed in the spectrum, and they correspondto the previously reported 2+ → 0+ and 4+ → 2+
transitions of 156 Nd,1) respectively. Based on the obtained results, we will assign the spin and parity of theparent nucleus, 156 Pr. In addition, γ transitions associated with the non-yrast levels of 156 Nd will be also
investigated.
These data are currently being analyzed.

∗1

Research Center for Nuclear Physics, Osaka University
LPSC, Université Grenoble-Alpes, CNRS/IN2P3∗3 Center for Nuclear Study, The University of Tokyo∗4 RIKEN Nishina Center∗5 Department of Physics, The University of Tokyo∗6 Peking University∗7 Department of Physics, Tohoku University∗8 University of Oslo
∗9 The University of Brighton∗10 Department of Physics, Osaka University∗11 ILL∗12 Department of Physics, Rikkyo University∗13 University of Tsukuba∗14 MTA Atomki, Debrecen, Hungary∗15 Hoseo University∗16 The University of Surrey∗17 University of York∗18 Instituto de Estructura de la Materia, CSIC
∗19 Universidad Autónoma de Madrid∗20 Beihang University∗2

Fig. 1. Gamma-ray energy spectrum after β decay of 156 Pr.

References
1) G. S. Simpson et al.: Phys Rev. C 80, 024304 (2009).
2) S. Nishimura: Nucl. Phys. News 22, No. 3 (2012).
3) Mn. Tanaka et al.: RIKEN Accel. Prog. Rep. 47, xvii
(2014).
4) S. Nishimura, et al.: RIKEN Accel. Prog. Rep. 46, 182(2013).

- 33 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Investigation of octupole correlations of neutron-rich Z ∼ 56 isotopes
through β-γ spectroscopy
R. Yokoyama,∗1 E. Ideguchi,∗2 G. Simpson,∗3 Mn. Tanaka,∗2 S. Nishimura,∗4 P. Doornenbal,∗4
P.-A. Söderström,∗4 G. Lorusso,∗4 Z. Y. Xu,∗5 J. Wu,∗4,∗6 T. Sumikama,∗7 N. Aoi,∗2 H. Baba,∗4 F. Bello,∗8
F. Browne,∗9,∗4 R. Daido,∗10 Y. Fang,∗10 N. Fukuda,∗4 G. Gey,∗3,∗4,∗11 S. Go,∗1,∗4 N. Inabe,∗4 T. Isobe,∗4
D. Kameda,∗4 K. Kobayashi,∗12 M. Kobayashi,∗1 T. Komatsubara,∗13 T. Kubo,∗4 I. Kuti,∗14 Z. Li,∗6
M. Matsushita,∗1 S. Michimasa,∗1 C.-B. Moon,∗15 H. Nishibata,∗10 I. Nishizuka,∗7 A. Odahara,∗10 Z. Patel,∗16,∗4
S. Rice,∗16,∗4 E. Sahin,∗11 L. Sinclair,∗17,∗4 H. Suzuki,∗4 H. Takeda, ∗4 J. Taprogge,∗18,∗19 Zs. Vajta,∗14
H. Watanabe,∗20 and A. Yagi∗10
A recent study on the existence of static octupole deformation in Ra isotopes1) attracted much attention.
The interaction between orbits with ∆J = ∆L = 3 is
responsible for octupole correlations and thus the nuclei with orbits having the properties near the Fermi
surface are expected to have large octupole correlations. This corresponds to Z or N ∼ 34, 56, 88, and134, and neutron-rich Ba isotopes (Z = 56, N ∼ 88)
are also expected to have large octupole correlations.
The Ba isotopes have been studied and octupole bands
with enhanced E1 transition rates have been discovered2) . However, the previous study revealed that theE1 rates do not peak at N = 88, 148 Ba92 has large
E1 rates comparable to as much as those of 144 Ba88 ,while 146 Ba90 has much smaller rates. Calculations ofoctupole correlation have large uncertainty and diﬀer
from each other. For example, ref3) predicts some β3
values in 150 Ba94 while ref4) argues that the β3 of 150 Ba
is almost zero. Experimental investigations of neutronrich isotopes in which no excited state is known, suchas 150 Ba, are important to understand the strange systematics of the E1 rates of the Ba isotopes.
We performed β-γ spectroscopy on neutron-rich Z ∼56 isotopes at RIBF. The neutron-rich isotopes were
produced using in-ﬂight ﬁssion of a 345MeV/nucleon
238
U beam. Fission fragments were identiﬁed by measuring the time-of-ﬂight and magnetic rigidity in the∗1

Center for Nuclear Study, The University of Tokyo
Research Center for Nuclear Physics, Osaka University∗3 LPSC, Université Grenoble-Alpes, CNRS/IN2P3∗4 RIKEN Nishina Center∗5 Department of Physics, The University of Tokyo∗6 Department of Physics, Peking University∗7 Department of Physics, Tohoku University∗8 Department of Physics, University of Oslo
∗9 School of Computing Engineering and Mathematics, University of Brighton∗10 Department of Physics, Osaka University∗11 ILL, Grenoble∗12 Department of Physics, Rikkyo University∗13 Department of Physics, University of Tsukuba∗14 MTA Atomki, Hungarian Academy of Science, Hungary∗15 Department of Display Engineering, Hoseo University∗16 Department of Physics, University of Surrey∗17 Department of Physics, University of York∗18 Instituto de Estructura de la Materia, CSIC
∗19 Departamento de Física Teórica, Universidad Autónoma de
Madrid∗20 Department of Physiscs, Beihang University∗2- 34 -

Fig. 1. Preliminary γ-ray energy spectra of the β decay
from 152 La to 152 Ce. The time window is 100 ms fromthe ion implantation. The low-energy peaks around 34
and 39 keV are Kα and Kβ X rays of Ce atoms, respectively, after the emission of conversion electrons.

second stage of BigRIPS and by measuring the energy
loss by using the ion chamber at the ﬁnal focal plane,
F11. The secondary beam was implanted into an active stopper WAS3ABi5) , which consists of ﬁve layersof double-sided-silicon-strip detectors. The γ rays fromthe implanted nuclei were detected using EURICA6) ,which is an array of 12-cluster Ge detectors in which
each cluster consists of 7 crystals.
Figure 1 shows the γ-ray energy and timing spectra of β-decay events after the implantation of 152 La.
Three known γ rays were conﬁrmed at 80.5, 182.5, and274.6 keV; these had been reported as E2 decays fromthe 2+ , 4+ , and 6+ states of the ground-state band of
152
Ce, respectively, by the spontaneous ﬁssion of 252 Cf
in ref7) . From this result for 152 Ce, the feasibility of themeasurement and analysis has been conﬁrmed. Analysis of Ba isotopes is in progress, and the results mayhelp us understand the octupole correlations of nuclei.
References
1) L. P. Gaﬀney et. al.: Nature 497, 199 (2013)
2) W. Urban et. al.: Nucl. Phys. A 613, 107 (1997)
3) P. A. Butler et. al.: Nucl. Phys. A 533, 249 (1991)
4) W. Nazarewicz et. al.: Nucl. Phys. A 429, 269 (1984)
5) S. Nishimura et. al.: RIKEN APR 46, 182 (2013)6) S. Nishimura: Nucl. Phys. News 22, No.3 (2012)7) H. J. Li et. al.: Phys. Rev. C 86, 067302 (2012)

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Decay spectroscopy of neutron-rich rare-earth isotopes- 35 -

Dy
Dy

174
174

Dy
Dy

172
172

170
170

66
66
64
64
62
62
2.54
2.54

2.56
2.56

2.58
2.58

2.6
2.6

2.62
2.62

2.64
2.64

2.66 A/q
2.66
A/q

Fig. 1. Combined particle identification obtained during
the two settings in the experiments.

8 → 8+

60

20

6+→ 4+

4+→ 2+

x-rays30

2+→ 0+

40

8+→ 6+

-

50

10
0
0

50

∗1

RIKEN Nishina Center∗2 Department of Physics, University of Surrey∗3 National Physical Laboratory, Teddington∗4 IRCNPC, Beihang University∗5 School of Physics and Nuclear Energy Engineering, Beihang
University∗6 Hong Kong University∗7 INR, Hungarian Academy of Sciences∗8 Department of Physics, Chung-Ang University∗9 Department of Physics, Tohoku University∗10 Hanoi University of Science∗11 School of Physics, Peking University∗12 Department of Physics, Osaka University∗13 Department of Physics, Almajmaah University∗14 School of Computing, Engineering and Mathematics, University of Brighton∗15 Department of Physics, Sungkyunkwan University∗16 School of Physics and Astronomy, University of Edinburgh∗17 RCNP, Osaka University∗18 GSI, Darmstadt∗19 Nuclear Engineering Division, Argonne National Laboratory∗20 Department of Nuclear Physics, Australian National University∗21 Hoseo University∗22 IFIN-HH, Bucharest∗23 School of Physics, University College Dublin∗24 Department of Physics, University of Tokyo∗25 INFN-LNL, Legnaro

Ho
Ho

68
68

Counts

The region in the nuclear chart between 50 < Z < 82
and 82 < N < 126 is the largest region between traditional nuclear shells and, thus, ideal to study theevolution of collectivity and K isomerism originatingfrom the high-j orbitals around mid-shell. Neglecting any potential sub-shell closures, the nucleus withthe largest number of valence particles in this region is170
Dy with proton number Z = 66 and neutron number N = 104. Accordingly it should be one of the mostcollective of all nuclei with A < 208, in its ground state.
From the high degree of axial symmetry and large deformation we expect several long lived, pure K isomers.
In particular, we expect a N = 104, K = 6+ isomer in170
Dy and a N = 106, K = 8− isomer in 172 Dy, similar
to the N = 102, K = 6− isomers in 166 Gd and 164 Sm
recently published1) .
A EURICA experiment was carried out in November
2014, where a 345 MeV/u 238 U beam impinged on a
Be target and the fragments separated and identified
in the BigRIPS separator and the ZeroDegree spectrometer and implanted in the WAS3 ABi active stopper. The experiment was carried out with two settings,
13.5 hours centering on 170 Dy and 45 hours centeringZ
Z

P.-A. Söderström,∗1 P.H. Regan,∗2,∗3 P. Walker,∗2 H. Watanabe,∗4,∗5 J.J. Liu,∗6 P. Doornenbal,∗1 Z. Korkulu,∗7
P. Lee,∗8 G. Lorusso,∗1,∗3 S. Nishimura,∗1 T. Sumikama,∗9 P. Vi,∗10 J. Wu,∗1,∗11 A. Yagi,∗12 G.X. Zhang,∗5
T. Alharbi,∗13 H. Baba,∗1 F. Browne,∗14 A.M. Bruce,∗14 R. Carroll,∗2 K.Y. Chae,∗15 Zs. Dombradi,∗7
A. Estrade,∗16 N. Fukuda,∗1 C. Griffin,∗16 E. Ideguchi,∗17 N. Inabe,∗1 T. Isobe,∗1 H. Kanaoka,∗12
I. Kojouharov,∗18 F.G. Kondev,∗19 T. Kubo,∗1 S. Kubono,∗1 N. Kurz,∗18 I. Kuti,∗7 S. Lalkovski,∗2 G. Lane,∗20
E.J. Lee,∗21 G. Lotay,∗2 C.-B. Moon,∗21 I. Nishizuka,∗9 C.R. Nita,∗14,∗22 A. Odahara,∗12 Z. Patel,∗2
Zs. Podolyák,∗2 O.J. Roberts,∗23 H. Sakurai,∗1,∗24 H. Schaffner,∗18 C.M. Shand,∗2 H. Suzuki,∗1 H. Takeda,∗1
S. Terashima,∗5 Zs. Vajta,∗7 J.J. Valiente-Dòbon,∗25 Z.Y. Xu,∗6 and S. Yoshida∗12

100

150

200

250

300

350

400

450 500Eγ (keV)Fig. 2. Combined γγ-coincidence spectrum gated on the
decays from the 8− isomer in 174 Er.

on 172 Dy. The combined PID is shown in Fig. 1.
In Fig. 2, the decay of the known N = 106, K = 8−
isomer in 174 Er2) is shown. This shows the capabilities
to measure very long lived isomers by triggering onconversion electrons in the 4+ → 2+ and 2+ → 0+transitions, in this case populated by the β-decay of174
Ho. This is not only the heaviest nucleus that has
been measured in EURICA but, with a half life of 4.0 s,
it is also the longest lived isomer. Besides the 170 Dy,
172
Dy, and the previously known 174 Er isomers, theexperimental data set contains several new isomers, βdelayed γ-rays and new β-decay half-lives. All of these
are currently under analysis.
References
1) Z. Patel, et al.: Phys. Rev. Lett. 113, 262502 (2014).
2) G. D. Dracoulis, et al.: Phys. Rev. C 79, 061303 (2009).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Rotational level structure of sodium isotopes
inside the “Island of Inversion” †

†
∗1
∗2
∗3
∗4
∗5
∗6

Condensed from the article in Prog. Theor. Exp. Phys.
2014, 053D01 (2014).
RIKEN Nishina Center
State Key Laboratory of Nuclear Physics and Technology,
Peking University
Advanced Science Research Center, Japan Atomic Energy
AgencyDepartment of Physics, Rikkyo University
Center for Nuclear Study, University of Tokyo
Department of Physics, Tokyo Institute of Technology- 36 -

400

a)

300

100
Na, Mγ <45033

Mγ < 3020040Mγ = 3

20

100

0

600

700

800

Counts / 25 keV

0
40

b)

34

c)

35

Na, Mγ <4

30
20
10
0

Counts / 25 keV

The study of neutron-rich Ne, Na, and Mg nuclei
around the breakdown of the N = 20 neutron magic
number, an area in the Segré chart termed “Island of
Inversion”1) has provided a wealth of information on
the evolution of nuclear shell structure away from thevalley of β stability. Due to its location in the proximity of the neutron drip-line, accessing the “Island of
Inversion” is an experimental challenge. In this paper,
we report on the first γ-ray spectroscopy performed
for the N = 23, 24 sodium isotopes 34,35 Na and a newtransition in 33 Na. For the latter nucleus, previous
measurements suggested that the observed two transi++
tions originate from a 7/2+
1 → 5/21 → 3/2g.s. cascade
and the energy ratio was found to be close to an ideal
K = 3/2 rotational band in the strong coupling limit2) .
A 48 Ca beam with an average intensity of 70 particle nA was accelerated by the Superconducting Ring
Cyclotron to 345 MeV/u and incident on a 15 mm
thick beryllium production target. A combination of
two magnetic dipoles and a 15 mm thick aluminum
degrader was utilized to filter a 36 Mg secondary beamwith the BigRIPS fragment separator3) by applying
the Bρ − ∆E − Bρ method. For further purification,a second aluminum degrader of 5 mm thickness wasinserted at the dispersive focal point of the second BigRIPS stage. After passing BigRIPS, the secondary
beams were incident on 2.54 g/cm2 carbon and 2.13
g/cm2 CH2 (polyethylene) reaction targets, respectively. BigRIPS was operated with its full momentum acceptance of ±3% and the average intensity of36
Mg was 90 particles per second. Gamma-rays emitted in coincidence with the secondary reactions weredetected with the DALI2 array4), which was composedof 186 large-volume NaI(Tl) detectors. The secondary
reaction products were identified with the ZeroDegree
Spectrometer3) .
In the present work, a third γ-ray transition was observed for 33 Na at 760(13) keV in addition to the two
known ones, and forms a doublet with the 7/2+
1 →
34
5/2+
Na, a sin1 decay. For the odd-odd nucleus

Counts / 25 keV

P. Doornenbal,∗1 H. Scheit,∗1,∗2 S. Takeuchi,∗1 Y. Utsuno,∗3 N. Aoi,∗1 K. Li,∗1,2 M. Matsushita,∗1,∗4
D. Steppenbeck,∗1 H. Wang,∗1,∗2 H. Baba,∗1 E. Ideguchi,∗5 N. Kobayashi,∗6 Y. Kondo,∗6 J. Lee,∗1
S. Michimasa,∗5 T. Motobayashi,∗1 T. Otsuka,∗5 H. Sakurai,∗1 M. Takechi,∗1 Y. Togano,∗1 and K. Yoneda∗1

80

Na, Mγ <4 15

10

60

5

40

0

20
0
0

500

1000

500

1000

1500
2000
Energy (keV)

Fig. 1. Doppler corrected γ-ray spectra in coincidence with
33
Na a), 34 Na b), and 35 Na c). The analysis was restricted to event with aγ-ray multiplicity Mγ of lessthan 4.

gle γ-ray transition was observed at 451(7) keV, while
the energy spectrum of 35 Na exhibited transitions at
373(5) and 641(16) keV. The level structure of the oddeven sodium isotopes was found to be well describedby the SDPF-M effective interaction5) .
References
1) E. K. Warburton et al., Phys. Rev. C 41, 1147 (1990).
2) A. Gade et al., Phys. Rev. C 83, 044305 (2011).
3) T. Kubo et al., Prog. Theor. Exp. Phys. 2012, 03C003(2012).
4) S. Takeuchi et al., Nucl. Instr. Meth. A 763, 596 (2014).
5) Y. Utsuno et al., Phys. Rev. C 60, 054315 (1999).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

In-beam γ-ray spectroscopy of 50 Ar
D. Steppenbeck,∗1 S. Takeuchi,∗1 N. Aoi,∗2 P. Doornenbal,∗1 M. Matsushita,∗3 H. Wang,∗1 H. Baba,∗1 S. Go,∗3
J. Lee,∗1 K. Matsui,∗4 S. Michimasa,∗3 T. Motobayashi,∗1 D. Nishimura,∗5 H. Sakurai,∗1,∗4 Y. Shiga,∗6
P.-A. Söderström,∗1 T. Sumikama,∗7 R. Taniuchi,∗4 J. J. Valiente-Dobón,∗8 and K. Yoneda∗1

∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

RIKEN Nishina Center
RCNP, University of Osaka
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Department of Physics, Tokyo University of Science
Department of Physics, Rikkyo University
Department of Physics, Tohoku University
Laboratori Nazionali di Legnaro- 37 -Counts / channel

104
49

Ar

103

50

Ar

2

10

10
1

2.6

2.7

2.8

2.9

Mass-to-charge ratio

Fig. 1. Particle identification plot (A/q) for Ar isotopes
measured using the ZeroDegree spectrometer.

Fig. 2. Two transitions with energies of ∼1.2 and, tentatively, ∼1.6 MeV are present in the spectrum and areassigned to 50 Ar in the present work. Details on the
structure of 50 Ar and the significance of the N = 32
subshell closure at Z < 20 will be presented elsewhere.
40

Counts / 50 keV

Owing to the advent of intense radioactive isotope
beams over recent years, it has become possible tostudy the structures of nuclei with large neutron-toproton ratios using techniques including in-beam γ-ray
spectroscopy and decay spectroscopy. One of the focal
points of such studies has been the evolution of nuclear shell structure in exotic radioisotopes, where thenuclear ‘magic’ numbers in stable systems have beenshown to deviate from their usual values. One such
example is the onset of the new neutron magic number N = 16 in exotic oxygen. On the contrary, thedisappearance of the standard magic number N = 28
has been investigated in 42 Si. In the neutron-rich f p
shell, development of a new subshell closure at N = 32
has been reported in Ca1–3) , Ti4,5) , and Cr6,7) isotones,
and more recently, a sizable subshell gap at N = 34
was reported in 54 Ca8) .
In the present study, the low-lying structure of 50 Ar(Z = 18) was investigated using multi-nucleon removal reactions from a fast radioactive beam containing 54 Ca, 55 Sc, and 56 Ti, among other constituents,
with the technique of in-beam γ-ray spectroscopy, inorder to gain further insight on the magnitude of the
N = 32 subshell closure at Z < 20. The secondary
beam was created using projectile fragmentation of70
Zn30+ ions at 345 MeV/u and products were identified on an event-by-event basis using the BigRIPS separator. A 10-mm-thick 9 Be reaction target was placedat the eighth focal plane of BigRIPS to induce nucleon
removal reactions and a high efficiency γ-ray detector
array9) (DALI2) was employed to measure transitions
from nuclear excited states populated by the reactions.
Reaction products were identified by the ZeroDegree
spectrometer; the particle identification plot for Ar
isotopes is provided in Fig. 1. Data acquisition was
triggered by the arrival of an ion at the end of ZeroDegree measured in coincidence with at least one γ ray in
DALI2. Data were recorded to disk for offline analysis
over a time period of approximately two days.
The Doppler-corrected γ-ray energy spectrum, deduced from the sum of the 9 Be(54 Ca,50 Ar+γ n )X,
9
Be(55 Sc,50 Ar+γ n )X, and 9 Be(56 Ti,50 Ar+γ n )X multinucleon removal reactions (n ≥ 1), is displayed in

50

Ar

30
20
10
0
0

1000

2000

3000

Transition energy (keV)

4000

Fig. 2. (colour online) Doppler-corrected γ-ray energy
spectrum for 50 Ar. The black dotted line and the blue
dashed lines are an exponential fit to the backgroundand GEANT4 simulations, respectively; the solid redline is the total (sum) fit.

References
1) A. Huck et al., Phys. Rev. C 31, 2226 (1985).
2) A. Gade et al., Phys. Rev. C 74, 021302(R) (2006).
3) F. Wienholtz et al., Nature 498, 346 (2013).
4) R. V. F. Janssens et al., Phys. Lett. B 546, 55 (2002).
5) D.-C. Dinca et al., Phys. Rev. C 71, 041302(R) (2005).
6) J. I. Prisciandaro et al., Phys. Lett. B 510, 17 (2001).
7) A. Bürger et al., Phys. Lett. B 622, 29 (2005).
8) D. Steppenbeck et al., Nature 502, 207 (2013).
9) S. Takeuchi et al., Nucl. Inst. Meth. A 763, 596 (2014).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Experimental study of isoscalar and isovector dipole resonances inneutron-rich oxygen isotopes
N. Nakatsuka,∗1,∗2 H. Baba,∗2 N. Aoi,∗10 T. Aumann,∗3 R. Avigo,∗5,∗14 S. R. Banerjee,∗12 A. Bracco,∗5,∗14
C. Caesar,∗3 F. Camera,∗5,∗14 S. Ceruti,∗5,∗14 S. Chen,∗13,∗2 V. Derya,∗4 P. Doornenbal,∗2 A. Giaz,∗5,∗14
A. Horvat,∗3 K. Ieki,∗11 N. Imai,∗7 T. Kawabata,∗1 K. Yoneda,∗2 N. Kobayashi,∗8 Y. Kondo,∗9 S. Koyama,∗8
M. Kurata-Nishimura,∗2 S. Masuoka,∗7 M. Matsushita,∗7 S. Michimasa,∗7 B. Millon,∗5 T. Motobayashi,∗2
T. Murakami,∗1 T. Nakamura,∗9 T. Ohnishi,∗2 H. J. Ong,∗10 S. Ota,∗7 H. Otsu,∗2 T. Ozaki,∗9 A. Saito,∗9
H. Sakurai,∗2,∗8 H. Scheit,∗3 F. Schindler,∗3 P. Schrock,∗3 Y. Shiga,∗11,∗2 M. Shikata,∗9 S. Shimoura,∗7
D. Steppenbeck,∗2 T. Sumikama,∗6 I. Syndikus,∗3 H. Takeda,∗2 S. Takeuchi,∗2 A. Tamii,∗10 R. Taniuchi,∗8
Y. Togano,∗9 J. Tscheuschner,∗3 J. Tsubota,∗9 H. Wang,∗2 O. Wieland,∗5 K. Wimmer,∗8 Y. Yamaguchi,∗7
and J. Zenihiro∗2
Giant resonance is one of the most important phenomena for understanding quantum many-body systems. Neutron-rich nuclei are predicted to have exotic giant resonances due to their smaller neutron separation energy and excess neutrons. One of the exotic giant resonances in neutron-rich nuclei is a dipole
resonance found at excitation energies lower than 10
MeV1) . The nature of these resonances is of great interest. One of the method to understand the nature ofthese resonances is to investigate if they are iso-vector
or iso-scalar resonances. In order to study the relationship between iso-vector and iso-scalar dipole resonances in neutron-rich oxygen isotopes, we performed
an experiment at RIBF and measure the dipole resonances of the neutron-rich nuclei 20 O, 22 O, and 24 O.
These beams were produced via projectile fragmentation of a 345MeV/nucleon 48 Ca beam on 9 Be targets
with mass thicknesses of 2.8 g/cm2 , 2.8 g/cm2 , and 2.2
g/cm2 . Γ rays from the excited beam particles weredetected with large volume LaBr3 crystals from INFN
Milano2) in combination with DALI23) . Two different
targets, 5 g/cm2 Au for coulomb excitation and 300
mg/cm3 liquid helium for inelastic α particle scattering, were used to obtain the iso-vector and iso-scaler
dipole strengths respectively.
A preliminary particle identification (PID) plot of Z
versus A/Z for the 24 O beam is shown in Fig. 1. PID
was performed by the Bρ-∆E-TOF technique using the
BigRIPS. The Bρ information was reconstructed fromthe time difference between the left- and right-handsides of the plastic scintillator installed at the disper-

sive focal plane. The achieved purity of 20 O, 22 O, and24
O was 73%, 66%, and 51%, respectively. PID of
the outgoing beams was performed by the same Bρ∆E-TOF technique using the ZD spectrometer. Lowpressure multi-wire drift chambers4) were used to measure Bρ of the outgoing beams. Figure 2 shows a preliminary PID plot of Z versus A/Z for the outgoing
beam where an 24 O beam is on a Au target. The reaction products are clearly observed. The analysis ofγ rays is in progress.

Fig. 1. PID plot of the 24 O beam setting∗1

Department of Physics, Kyoto University
RIKEN Nishina Center∗3 Institut für Kernphysik, Technische Universität Darmstadt∗4 Institut für Kernphysik, Universität zu Köln∗5 Istituto Nazionale di Fisica Nucleare Milan∗6 Department of Physics, Tohoku University∗7 Center for Nuclear Study, The University of Tokyo∗8 Department of Physics, The University of Tokyo∗9 Department of Physics, Tokyo Institute of Technology∗10 Research Center for Nuclear Physics, Osaka University∗11 Department of Physics, Rikkyo University∗12 Variable Energy Cyclotron Centre, The Indian Department
of Atomic Energy∗13 School of Physics, Peking University∗14 University of Milan∗2- 38 -

Fig. 2. PID plot of the 24 O beam and the Au target setting
on ZD spectrometer

References
1) V. Derya et al. J. Phys. Conf. Ser. 366, 012012 (2012)
2) A. Giaz et al. Nucl. Instrum. Methods Phys. Res., Sec.
A 729, 910 (2013)3) S. Takeuchi et al. Nucl. Instrum. Methods Phys. Res.,
Sec. A 763, 596 (2014)4) H. Miya et al. Nucl. Instrum. Methods Phys. Res., Sec.
B 317, 701 (2013)

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Study of the pygmy-dipole resonances of 132 Sn and 128 Sn in inelastic
α-scattering

Z

J. Tscheuschner,∗1,∗2 T. Aumann,∗1 D. S. Ahn,∗2 R. Avigo,∗3,∗4 H. Baba,∗2 K. Boretzky,∗5 A. Bracco,∗3,∗4
C. Caesar,∗5 A. Camera,∗3,∗4 S. Chen,∗2,∗6 V. Derya,∗7 P. Doornenbal,∗2 J. Endres,∗7 N. Fukuda,∗2 U. Garg,∗8
A. Giaz,∗3,∗4 M. N. Harakeh,∗9 M. Heil,∗5 A. Horvat,∗1 K. Ieki,∗10 N. Imai,∗11 N. Inabe,∗2
N. Kalantar-Nayestanaki,∗9 N. Kobayashi,∗11 Y. Kondo,∗12 S. Koyama,∗11 T. Kubo,∗2 I. Martel,∗13
M. Matsushita,∗14 B. Million,∗15 T. Motobayashi,∗2 T. Nakamura,∗12 N. Nakatsuka,∗2,∗16 M. Nishimura,∗2
S. Nishimura,∗2 S. Ota,∗14 H. Otsu,∗2 T. Ozaki,∗12 M. Petri,∗1 R. Reifarth,∗17 D. Rossi,∗18 A. Saito,∗12
H. Sakurai,∗2,∗11 D. Savran,∗5 H. Scheit,∗1 F. Schindler,∗1 P. Schrock,∗1 D. Semmler,∗1 Y. Shiga,∗2,∗10
M. Shikata,∗12 Y. Shimizu,∗2 H. Simon,∗5 D. Steppenbeck,∗2 H. Suzuki,∗2 T. Sumikama,∗19 D. Symochko,∗1
I. Syndikus,∗1 H. Takeda,∗2 S. Takeuchi,∗2 R. Taniuchi,∗11 Y. Togano,∗12 J. Tsubota,∗12 H. Wang,∗2
O. Wieland,∗3 K. Yoneda,∗2 J. Zenihiro,∗2 and A. Zilges∗7
52
Pygmy-dipole resonance is commonly considered asa dipole mode of the nucleus related to a vibration
103
of excess neutrons against a core. As such, it should50
be related to the neutron richness of the nucleus as
102
well as its neutron-skin thickness. So far, the experSn-13249+
Sn-13248
imental information on this low-lying dipole mode isastonishingly scarce, even for stable nuclei1) . One in10
teresting open question is the isospin character of the46
low-lying dipole strength. In an experiment with the
2.55
2.6
2.65
2.7
2.75 1stable 124 Sn isotope2) , it has been concluded that a
A/Qlarge fraction of the pygmy strength is of isoscalar charFig. 1. Particle identification plot of the secondary beamacter, however significant differences in the strength
after the liquid Helium target, gated on incoming 132 Sn
distribution compared with photoexcitation have beenions determined using the ZeroDegree spectrometer.
observed.
ber to achieve a high geometric acceptance.
In November 2014, the isoscalar mode of the pygmyAs a first step of the analysis, the preliminary par128
132
Sn andSn isotopes weredipole resonances inticle identification (PID) plot of Z versus A/Q canmeasured in inelastic α-scattering at RIKEN. The isobe
determined by a combination of the measured entopes of interest were produced with a high-intensity
ergy
loss, magnetic rigidity, and the time-of-flight
primary 238 U beam of 345 MeV/u impinging on ausing
the BigRIPS and the ZeroDegree spectromeberyllium target. The resulting secondary beam with
5).
As a result, beam purity was dertermined toteran energy of approximately 200 MeV/u was directedbe18%
for 128 Sn and 26% for 132 Sn. As an extowards the liquid helium target with a thickness of
ample,
theresulting PID for the outgoing particles
approximately 300 mg/cm2 . The γ-rays, which are132Snexperiment is shown in Fig. 1. In
fortheejected at the target position, have been measured by
the
plot,
different
charge states for 132 Sn can be ob8 large-volume 3.5”×8”LaBr3 :Ce crystals from Hector
served. However, the 129 Sn49+ -state has to be conINFN Milano3) and 95 large-volume NaI(Ti) DALI24)
sidered, because it has a similar A/Q-value as the
crystals. These crystals surrounded the target chamfully stripped 132 Sn ion (A/Q(129 Sn49+ )=2.633 andA/Q(132 Sn50+ )=2.640). The pygmy-dipole resonances∗1 Institut für Kernphysik, TU Darmstadt∗2 RIKEN Nishina Centercan be identified by the correlation of the identified∗3 INFN sezione di Milano
particles to the corresponding γ-rays. Finally, the∗4 Dipartimento di Fisica, Universita degli studi di Milano
strength of the isoscalar pygmy-dipole resonances can∗5 GSI Helmholtzzentrum Darmstadt
be determined. In addition, experiments already per∗6 School of Physics, Peking University∗7 Institute für Kernphysik, Universität zu Kölnformed at GSI Darmstadt with the R3 B setup will
∗8 Department of Physics, University of Notre Dameprofit, because with the result of this experiment, the∗9 KVI-CART Groningenisovector part of the resonance can be separated from∗10 Department of Physics, Rikkyo University
the isoscalar part.
∗11 Department of Physics, University of Tokyo∗12 Department of Physics, Tokyo Institut of Technoloy
References∗13
p2

Entries

Mean x3548250
2.627

Mean y

49.11

RMS x

0.03813RMS y

0.877450+

Departamento de Fisica Aplicada, Universidad de Huelva∗14 Center for Nuclear Research, University of Tokyo∗15 VECC India∗16 Department of Physics, Kyoto University∗17 Institut für Kernphysik, Goethe Universität Frankfurt∗18 National Supercoducting Cyclotron Laboratory,

MichiganState University∗19 Department of Physics, Tohoku University- 39 -

1) D. Savran et al.: Prog. Part. Nucl. Phys. 70, p.210(2013).
2) J. Endres et al.: Phys. Rev. Lett. 105, 212503 (2010).
3) A. Giaz et al.: NIM A729, 910 (2013).
4) S. Takeuchi et al.: NIM A 763, 596 (2014).
5) T. Kubo et al.: Prog. Theor. Exp. Phys. 03C003 (2012).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Coulomb excitation of 130 Cd
H. Wang,∗1 N. Aoi,∗2 P. Doornenbal,∗1 S. Takeuchi,∗1 M. Matsushita,∗3 Y. Shiga,∗1,∗4 D. Steppenbeck,∗3
R. Taniuchi,∗1,∗5 R. Avigo,∗6 H. Baba,∗1 C. Bauer,∗7 Z. Dombradi,∗8 Z. Elekes,∗8 E. Ideguchi,∗2 T. Isobe,∗1
A. Jungclaus,∗9 J. Lee,∗1 H. Liu,∗1,∗10 S. Momiyama,∗5 T. Motobayashi,∗1 K. Nacher,∗9 M. Niikura,∗5
S. Nishimura,∗1 A. Obertelli,∗11 H. Otsu,∗1 H. Sakurai,∗1 C. Santamaria,∗11 P.-A. Söderström,∗1
T. Sumikama,∗12 J. Taprogge,∗9 Z. Vajta,∗8 J. Wu,∗1,∗10 Z. Xu,∗1 T. Yamamoto,∗2 and K. Yoneda∗1
A 1-mm-thick Bi target was used to induce Coulomb
excitation reactions. De-excitation γ rays were detected by the DALI2 spectrometer6) , which surrounded
the secondary target. Reaction residues were collected
and analyzed by the ZeroDegree spectrometer5) . The
spectrometer was optimized for the transportation of
130
Cd. Particle identiﬁcation was performed again using the TOF – Bρ − ∆E method, as in BigRIPS.
In addition, a LaBr3 (Ce) scintillation detector (SaintGobain BrilLanCeT M 380) located downstream of theionization chamber was used for the total kinetic energy measurement.
The analysis for the B(E2) value is currently inprogress.

Atomic number Z

The properties of the nuclei beyond 132 Sn havedrawn considerable attention recently because thisdoubly magic nucleus lies far away the line of β stability. The evolution of the N = 82 shell gap to the“south” of 132 Sn has been discussed in several studies1,2) . For nuclear astrophysics, it has been suggested
that the N = 82 shell closure aﬀects the r-process
abundance distribution around mass A ≈ 1302) . However, for the N = 82 magicity in the Cd (Z = 48) isotopes, the mass and the spectroscopy measurements
show contradictory results. The Qβ value of 130 Cd
was better reproduced by a mass model assuming aquenched shell gap3) . However, a good shell closure
was suggested from the ﬁrst 2+ state as the excitationenergy of 1.3 MeV4) is close to those in other even-even
N = 82 isotones. In order to investigate the magic
character of N = 82 in 130 Cd, we measured the reduced transition possibility (B(E2)) via the Coulomb
excitation.
The secondary beams were produced from an
in-ﬂight ﬁssion reaction of a U primary beam at
345 MeV/nucleon incident on a 3-mm-thick Be target located at the object point of the BigRIPS fragment separator5) . The average beam intensity was
about 10 particle nA. The ﬁssion products around130
Cd were selected and puriﬁed by employing two
wedge-shaped aluminum energy degraders with thicknesses of 8 and 2 mm, respectively, located at the dispersive foci. The momentum acceptance of BigRIPS
was set to 5%. The secondary beam was identiﬁed
event-by-event via the TOF – Bρ − ∆E method using
standard BigRIPS detectors. Figure 1 shows a twodimensional plot of Z versus A/Q for the secondary
beam in BigRIPS. The intensity of the 130 Cd beam
was 15 counts/s with a purity of 1.3%. The beam energy was about 160 MeV/nucleon before the secondary
target.

132

51

Sn
10

2

50

49

48

130

10

Cd

47

46
2.62 2.64 2.66 2.68 2.70 2.72 2.74 2.76

1Mass-to-charge ratio A/Q
Fig. 1. Particle identiﬁcation plot of the secondary beams
in BigRIPS.

References∗1

RIKEN Nishina Center∗2 RCNP, Osaka University∗3 CNS, University of Tokyo∗4 Department of Physics, Rikkyo University∗5 Department of Physics, University of Tokyo∗6 INFN, Italy∗7 TU Darmstadt, Germany∗8 Institute for Nuclear Research, Hungary∗9 Instituto de Estructura de la Materia, CSIC
∗10 School of Physics and State Key Laboratory of Nulcear
Physics and Technology, Peking University∗11 CEA Saclay, France∗12 Department of Physics, Tohoku University- 40 -

1) J. Dobaczewski et al.: Phys. Rev. Lett. 72, 981 (1994).
2) B. Pfeiﬀer et al.: Nucl. Phys. A 693, 282 (2001).
3) I. Dillmann et al.: Phys. Rev. Lett. 91, 162503 (2003).
4) A. Jungclaus et al.: Phys. Rev. Lett. 99, 132501 (2007).
5) T. Kubo et al.: Prog. Theor. Exp. Phys. 2012, 03C003(2012).
6) S. Takeuchi et al.: Nucl. Instr. Meth. A 763, 596 (2014).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Search of E1 strength around threshold in 70Ni†
R. Avigo,*1,*2 O. Wieland,*1 A. Bracco,*1,*2 F. Camera,*1,*2 H. Baba,*3 N. Nakatsuka,*4 P. Doornenbal,*3 Y. Togano,*5
J. Tscheuschner,*6 T. Aumann,*6 G. Benzoni,*1 N. Blasi,*1 K. Boretzky,*7 S. Brambilla,*1 S. Ceruti,*1,*2 S. Chen,*8
F.C.L. Crespi,*1,*2 N. Fukuda,*3 A. Giaz,*1,*2 K. Ieki,*9 N. Kobayashi,*10 Y. Kondo,*5 S. Koyama,*10 T. Kubo,*3 S. Leoni,*1,*2
M. Matsushita,*11 B. Million,*1 A.I. Morales,*1,*2 T. Motobayashi,*3 T. Nakamura,*5 M. Nishimura,*3 S. Nishimura,*3 H. Otsu,*3
T. Ozaki,*5 L. Pellegri,*1,*2 A. Saito,*5 H. Sakurai,*3 H. Scheit,*6 P. Schrock,*6 Y. Shiga,*3 M. Shikata,*5 D. Steppenbeck,*3
T. Sumikama,*12 S. Takeuchi,*3 R. Taniuchi,*10 J. Tsubota,*5 H. Wang,*3 and K. Yoneda*3
The structure and nature of the E1 strength distribution
around the separation energy depends mainly on the neutron
excess. Some information in stable nuclei has been obtainedin the past but only very few data are available for exotic
neutron rich nuclei using mainly Coulomb excitation
techniques1) and references therein.
There is an ongoing discussion on the possibility of
extracting information on the neutron skin from the pygmy
resonance strength2). This quantity can be related to theisospin-dependent part of the nuclear equation of state(EOS) which in turn has relevant implications for thedescription of neutron stars. Furthermore, the presence of astrength with E1 character close to the particle threshold has
important astrophysical implications in explosive
nucleosynthesis scenarios.
In order to understand better the characteristics of thispygmy dipole strength it is important to study an isotopic
chain of a nucleus with increasing neutron number. As the
pygmy dipole strength distribution in 68Ni around thethreshold has recently been studied1,2,3), a new high intensity
and high resolution experiment was performed on 70Ni at
RIKEN Radioactive Isotope Beam Factory (RIBF) in
November 2014.
A 238U primary beam was accelerated up to an energy of
345 AMeV and made to impinge on a thick rotating Be
production target. In BigRIPS4) the B-E- B method wasapplied to select and purify a secondary beam of 70Ni (30kcps with 40% purity at a beam energy of 260 AMeV). The
70
Ni isotope was incident on a 2 g/cm2 thick gold secondary
target. Reaction residues from the secondary target wereidentified using the ZeroDegree Spectrometer. Scattering
angles were determined using parallel plate avalanche
counters.

To detect gamma rays from the decay of different nuclear
levels the reaction target was surrounded by a combinationof the DALI2 array5) (consisting of 96 NaI(TI) crystals) and8 large volume 3.5’’ x 8’’ LaBr3:Ce detectors6) mounted at
30° in the forward direction. These latter detectors have ahigh efficiency, excellent energy resolution for high energy
gamma rays and very good time resolution.

Fig. 1. Particle identification plot (B-E- B TOF of thesecondary beam in front of the Au reaction target. The 70Ni
isotopes are labeled.
Fig. 1 shows the particle identification plot taken during
the experiment can be seen. The data are under analysis.
The first preliminary outcome will be the 2+ state strengthof 70Ni. This known 2+0+gs E2 transition strength will betaken as a benchmark for the determination of the unknown
E1 transitions strengths below and above the threshold.
Presently high energy gamma ray events in the LaBr3:Ce
detectors and add back spectra in DALI2 are being analyzed.
The determination of the E1 strength distribution of themeasured 70Ni and the subsequent analysis of the relation
between strength and neutron skin together with the data ofthe measured 68Ni will give a better and important
contribution to the understanding of the features of thepygmy dipole strength.

†

Experiment NP1306 -RIBF51R1, November 2014
INFN sezione di Milano*2
University of Milano*3
RIKEN Nishina Center*4
Kyoto University*5
Department of Physics, Tokyo Institute of Technology*6
TU Darmstadt*7
GSI Darmstadt*8
Peking University*9
Rikkyo University*10
University of Tokyo*11
CNS, University of Tokyo*12
Tohoku University*1

References

1) O. Wieland et al. PRL 102, 092502 (2009).
2) A. Carbone et al. Phys. Rev. C 81 041301(R) (2010).
3) D. Rossi et al. PRL 111, 242503 (2013).
4) T. Kubo et al. Prog. Theor. Exp. Phys. 03C003 (2012).
5) S. Takeuchi et al. NIM A763, 596 (2014).
6) A. Giaz et al. NIM A729, 910 (2013).

- 41 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Structure at and beyond the dripline in the vicinity of the
N=14 and 16 sub-shell closures
S. Leblond,∗1 Y. Kondo,∗2 J. Gibelin,∗1 F. M. Marqués,∗1 T. Nakamura,∗2 N. A. Orr,∗1 S. Ogoshi,∗2
R. Minakata,∗2 R. Tanaka,∗2 N. L. Achouri,∗1 T. Aumann,∗3 H. Baba,∗4 F. Delaunay,∗1 P. Doornenbal,∗4
N. Fukuda,∗4 J. W. Hwang,∗5 N. Inabe,∗4 T. Isobe,∗4 D. Kameda,∗4 D. Kanno,∗2 S. Kim,∗5 N. Kobayashi,∗2
T. Kobayashi,∗6 T. Kubo,∗4 J. Lee,∗4 T. Motobayashi,∗4 D. Murai,∗7 T. Murakami,∗8 K. Muto,∗6
T. Nakashima,∗2 N. Nakatsuka,∗8 A. Navin,∗9 S. Nishi,∗2 H. Otsu,∗4 H. Sato,∗4 Y. Satou,∗5 Y. Shimizu,∗4
H. Suzuki,∗4 K. Takahashi,∗6 H. Takeda,∗4 S. Takeuchi,∗4 Y. Togano,∗10 A. G. Tuff,∗11 M. Vandebrouck,∗12
and K. Yoneda∗4∗1

LPC-Caen, ENSICAEN, Université de Caen, CNRS/IN2P3
Department of Physics, Tokyo Institute of Technology∗3 Institut für Kernphysik, Technische Universität Darmstadt∗4 RIKEN Nishina Center∗5 Department of Physics and Astronomy, Seoul National University∗6 Department of Physics, Tohoku University∗7 Departiment of Physics, Rikkyo University∗8 Department of Physics, Kyoto University∗9 GANIL, CEA/DSM-CNRS/IN2P3∗10 ExtreMe Matter Institute (EMMI) and Research Division,
GSI∗11 Department of Physics, University of York∗12 Institut de Physique Nucléaire, Université Paris-Sud,
IN2P3-CNRS, Orsay

22

C + C → 20C + n + X

Counts / 100 keV

200

150

100

50

00

800

1

700

22

2

3

4

5

2

3

4

5

N + C → 20C + n + X

600

Counts / 50 keV

The structure of the neutron-rich nuclei in the vicinity of the N=14 and 16 sub-shell closures have attracted considerable interest in recent years. In particular, 19 B and 22 C represent the heaviest canididate two-neutron halo systems1–3) whilst also spanning
N=14 and 16 below doubly-magic 22,24 O. In terms ofthe most neutron-rich oxygen isotopes, the behaviour
beyond 24 O, with the ultimate goal of investigating
28
O, has taken on renewed interest in the light of recent
improvements in sophisticated structure modelling4,5) .
The present report describes the status of the analysisof data acquired during a series of three experiments,
undertaken with these goals in mind, as part of theinitial phase of operation of the SAMURAI spectrometer6) coupled to the large area neutron array NEBULA7) and DALI28) NaI array.
One of the systems of particular interest in termsof modelling 22 C and the evolution of the ν2s1/2 andν1d5/2 levels is 21 C9) , the unbound sub-system of Borromean 22 C. In the present work we have attemped
to populate 21 C via both neutron and proton removalfrom 22 C and 22 N respectively, whereby it is expectedthat the different valence neutron configurations of the
projectile ground states should result in the population of correspondingly different final states. Figure 1
shows the reconstructed 20 C+n invariant mass (or decay energy) spectra for the two reactions. As may beseen, the selectivety of the two reactions is markedly
different, with neutron removal from 22 C exhibiting inparticular a rather narrow structure close to 1.5 MeV.
We note that in comparison to the featureless, but very
limited statistics spectrum of Ref.10) , the proton removal from 22 N shows here a very pronounced struc-

500
400
300
200
100
00

1

Edecay (MeV)

Fig. 1. Preliminary results for the 20 C+n decay energy
spectra obtained for neutron (upper) and proton (lower
panel) removal reactions at 240 MeV/nucleon. The dotted line, normalised at high decay energy, represents anevent-mixed estimate of the corresponding uncorrelated
distribution.

∗2- 42 -

ture at around 1 MeV.
The further analysis of these preliminary results iscurrently underway, including the extraction of the
20
C+n momentum distribution for the neutron removal channel, which will shed light on the angularmomentum of the removed neutron and hence the character of the corresponding 21 C states. Analysis of thedata acquired for two-proton removal from 23 O is alsoin progress with the initial results exhibiting a decay

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

estimated, which are in line with the results of earlier studies undertaken elsewhere employing the same
reaction12,13) .
Work is currently proceeding to finalise the analysis of the data acquired for single-proton removal from27
F to populate 26 O. To date the 24 O+2n decay energy
spectrum has been successfully reconstructed after implementation of neutron cross talk rejection procedures
based on kinematic conditions. The spectrum exhibitsa feature at around 1.3 MeV, which represents the firstobservation of an excited (presumably 2+ ) state in 26 O,
together with a very sharp peak at threshold corresponding to the ground state13,14) . A detailed analysis is being performed to determine the characteristics(energies and widths) of both states. The considerably
higher statistics obtained in the present work should
allow for a much more precise determination of theground state energy. In the near future the data acquired for the two-proton removal from 27,28 Ne will
also be exploited in the hope of providing further insight into the structure of 25,26 O.
We note that in an earlier report15) , intensities werequoted for the secondary beams employed for the investigation of 25,26 O. For reference, for future experiments, Table 1 lists updated determinations of theintensities.
The work described here relating to the investigation of 21 C forms part of the PhD thesis of S. Leblond(LPC-Caen).

Fig. 2. Preliminary results for the 24 O+n relative energy
spectrum obtained for proton removal from 26 F at 212
MeV/nucleon. The solid curve shows the results of a fit
assuming a single resonance (see text)

Beam

Energy(MeV/nucleon)

∆P/P
(%)

Intensity(kpps/100pnA)

27

241
212
212
240

±3
±3
±0.6
±0.6

1.0
29
2.5
14

F
Ne
26
F
27
Ne
28

References

Table 1. Intensities, in terms of the 48 Ca primary beam
(354 MeV/nucleon) intensity (pnA), for the secondary
beams employed to investigate 25,26 O. The momentum
aecceptance of the BigRIPS separator is noted in eachcase as is the mean secondary beam energy.

1) K. Tanaka et al.: Phys. Rev. Lett. 104, 062701 (2010).
2) N. Kobayashi et al.: Phys. Rev. C83, 054604 (2012).
3) L. Gaudefroy et al.: Phys. Rev. Lett. 109, 20503(2012).
4) T. Otsuka et al.: Phys. Rev. Lett. 105, 032501 (2010).
5) G.R. Jansen et al.: Phys. Rev. Lett. 108, 242501(2012).
6) T. Kobayashi et al.: Nucl. Instr. Meth. B 317, 294(2013).
7) Y. Kondo et al.: RIKEN Accel. Prog. Rep. 45, 131(2012); http://be.nucl.ap.titech.ac.jp/~nebula8) S. Takeuchi et al.: Nucl. Instr. Meth. B A763, 596(2014).
9) G. Jansen et al.: Phys. Rev. Lett. 113, 142502 (2014).
10) S. Mosby et al.: Nucl. Phys. A909, 69 (2013).
11) T. Nakamura et al.: Phys. Rev. Lett. 96, 252502(2006).
12) C.R. Hoffman et al.: Phys. Rev. Lett. 100, 152502(2008).
13) C. Caeser et al.: Phys. Rev. C88, 034313 (2013).
14) E. Lunderberg et al.: Phys. Rev. Lett. 108, 142503(2012).
15) Y. Kondo et al.: RIKEN Accel. Prog. Rep. 46, 6(2013).

energy spectrum similar to that observed in singleproton removal from 22 N.
Data was also acquired for reactions of 19 B and 22 C
beams on a Pb target with the goal of deducing theE1 strength functions for the two-neutron dissociation
channel. This should enable further constraints to beplaced on the halo structure of both nuclei as well as
insight into the halo neutron spatial configurations11) .
The analysis of the data is on going, with very preliminary results indicating that both nuclei exhibit considerable near threshold strength.
In the case of the heavy oxygen isotopes, the analysis of the data obtained for proton removal from a 26 F
beam to populate 25 O is in its final stages. Figure 2
shows the preliminary results obtained for the 24 O+n
decay energy spectrum, including a comparison withthe best fit results for an =2 resonance. A resonanceenergy of 0.75 MeV and width of 0.09 MeV have been

- 43 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Study of neutron-unbound states of 19 C at SAMURAI

The neutron-unbound region of the nuclear levelstructure has been investigated extensively in recent
years, especially for nuclei near the neutron drip line.
In this report, we provide the result of the experiment
to study neutron-unbound states in 19 C by usin a oneneutron knockout reaction. The report contains theoutcome of the succeeding research following the report in the previous year.1)
The experiment was performed at the RIBF facility.
A 20 C secondary beam at 280 MeV/nucleon separated
by BigRIPS impinged on a 1.8 g/cm2 -thick carbon target. Neutron-unbound states of 19 C produced by oneneutron knockout decays into a 18 C ion and a neutron.
18
C was identified and its momentum was measured
using the SAMURAI spectrometer2) with the help of
its experimental appratus. Arrays of plastic scintillators for neutron detection (NEBULA) were used tomeasure the momenta of decay neutrons.3) The experimental setup is identical to that of Ref.4) .
A preliminary relative energy spectrum for the system of 18 C + n is shown in Fig. 1 with the result offitting analysis. Acceptance was corrected for considering the effect of the geometry of the detector system, which was estimated using a Monte-Carlo simulation. Error bars are statistical ones. Briet-Wigner
shape functions were used as response functions generated using a simulation code taking the detector resolution into account. The background consists of a
Boltzmann-type distribution for non-resonant continuum and a distribution for uncorrelated 18 C + n pairsreconstructed using the event mixing technique. A different scale from 0.5 MeV is taken in the y-axis be∗1

Department of Physics and Astronomy, Seoul National University∗2 RIKEN Nishina Center∗3 LPC-Caen, ENSICAEN, Université de Caen, CNRS/IN2P3∗4 Department of Physics, Tokyo Institute of Technology∗5 Institut für Kernphysik, Technische Universität Darmstadt∗6 Department of Physics, Tohoku University∗7 Department of Physics, Rikkyo University∗8 Department of Physics, Kyoto University∗9 GANIL, CEA/DSM-CNRS/IN2P3∗10 ExtreMe Matter Institute (EMMI) and Research Division,
GSI∗11 Department of Physics, University of York∗12 Institut de Physique Nucléaire, Université Paris-Sud,
IN2P3-CNRS∗13 Present address:Department of Physics, Tokyo Institute ofTechnology- 44 -

dσ/dErel (mb/MeV)

J.W. Hwang,∗1,∗2 Y. Satou,∗1 S. Kim,∗1,∗2 N. A. Orr,∗3 T. Nakamura,∗4,∗2 Y. Kondo,∗4,∗2 N. L. Achouri,∗3
T. Aumann,∗5 H. Baba,∗2 F. Delaunay,∗3 P. Doornenbal,∗2 N. Fukuda,∗2 J. Gibelin,∗3 N. Inabe,∗2 T. Isobe,∗2
D. Kameda,∗2 D. Kanno,∗4,∗2 N. Kobayashi,∗4,∗2 T. Kobayashi,∗6,∗2 T. Kubo,∗2 S. Leblond,∗3 J. Lee,∗2
F. M. Marques,∗3 R. Minakata,∗4,∗2 T. Motobayashi,∗2 D. Murai,∗7 T. Murakami,∗8 K. Muto,∗6 N. Nakatsuka,∗8
T. Nakashima,∗4,∗2 A. Navin,∗9 S. Nishi,∗4,∗2 S. Ogoshi,∗4,∗2 H. Otsu,∗2 H. Sato,∗2 Y. Shimizu,∗2 H. Suzuki,∗2
K. Takahashi,∗6 H. Takeda,∗2 S. Takeuchi,∗2 R. Tanaka,∗4,∗2 Y. Togano,∗10,∗13 A. G. Tuff,∗11
M. Vandebrouck,∗12 and K. Yoneda∗2
600

50

x 12

40

400

30
20

200

10

0
0

0.5

1

1.5

2

2.5

3

3.5
4
Erel (MeV)

0

Fig. 1. Preliminary relative energy spectrum for the system of 18 C + n (filled circles). The black solid line is
the result of the fit; the dashed lines are for the two resonances; the dot-dashed line is the assumed background.
(see details in the text)

cause of the significant threshold resonance. Three resonances were observed at Erel = 36±1 keV, 0.84±0.02
MeV and 2.33 ± 0.01 MeV, corresponding to the statesof Ex = 0.62(9) MeV, 1.42(9) MeV, and 2.91(9) MeV,
respectively, based on the formula: Ex = Erel + Sn ,where Sn is the one-neutron separation energy of 19 C
(0.58(9) MeV5) ). Note that all values are preliminary.
While the first and second resonances are consistent+
with the 5/2+
1 and 5/22 states reported by the knock6)
out experiment and the inelastic scattering measurement7) , respectively, the third one was observed for the
first time in the present study. A next step of analysis
is planned to obtain the parallel momentum distribution of the knockout residue to investigate spins andparities of the observed states.
References
1) J. W. Hwang et al.: RIKEN Accel. Prog. Rep. 47, xix(2014).
2) T. Kobayashi et al.: Nucl. Instr. Meth. B 317, 294(2013).
3) Y. Kondo et al.: RIKEN Accel. Prog. Rep. 45, 131(2012).
4) Y. Kondo et al.: RIKEN Accel. Prog. Rep. 46, 6 (2013).
5) M. Wang et al: Chin. Phys. C 36, 1603 (2012).
6) M. Thoennessen et al.: Nucl. Phys. A 912, 1 (2013).
7) Y. Satou et al.: Phys. Lett. B 660, 320 (2008)

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Measurement of unbound states in 17 C at SAMURAI
S. Kim,∗1,∗2 Y. Satou,∗1 J.W. Hwang,∗1,∗2 T. Nakamura,∗2,∗3 N. A. Orr,∗4 Y. Kondo,∗2,∗3 J. Gibelin,∗4
N. Kobayashi,∗2,∗3 R. Tanaka,∗2,∗3 R. Minakata,∗2,∗3 S. Ogoshi,∗2,∗3 S. Nishi,∗2,∗3 D. Kanno,∗2,∗3
T. Nakashima,∗2,∗3 N. L. Achouri,∗4 T. Aumann,∗5 H. Baba,∗2 F. Delaunay,∗4 P. Doornenbal,∗2 N. Fukuda,∗2
N. Inabe,∗2 T. Isobe,∗2 D. Kameda,∗2 T. Kobayashi,∗6,∗2 T. Kubo,∗2 S. Leblond,∗4 J. Lee,∗2 F. M. Marqués,∗4
T. Motobayashi,∗2 D. Murai,∗7 T. Murakami,∗8 K. Muto,∗6 N. Nakatsuka,∗8 A. Navin,∗9 H. Otsu,∗2 H. Sato,∗2
Y. Shimizu,∗2 H. Suzuki,∗2 K. Takahashi,∗6 H. Takeda,∗2 S. Takeuchi,∗2 Y. Togano,∗10,∗13 A. G. Tuff,∗11
M. Vandebrouck,∗12 and K. Yoneda∗2

Department of Physics and Astronomy, Seoul National University∗2 RIKEN Nishina Center∗3 Department of Physics, Tokyo Institute of Technology∗4 LPC-Caen, ENSICAEN, Université de Caen, CNRS/IN2P3∗5 Institut für Kernphysik, Technische Universität Darmstadt∗6 Department of Physics, Tohoku University∗7 Department of Physics, Rikkyo University∗8 Department of Physics, Kyoto University∗9 GANIL, CEA/DSM-CNRS/IN2P3∗10 ExtreMe Matter Institute (EMMI) and Research Division,
GSI∗11 Department of Physics, University of York∗12 Institut de Physique Nucléaire, Université Paris-Sud,
IN2P3-CNRS∗13 Department of Physics, Tokyo Institute of Technology∗1- 45 -

25
20

dσ/dErel (mb/MeV)

To study unbound states in 17 C above the neutron
separation energy of 0.735(18) MeV1) , an experiment
was performed at RIBF during the first physics run of
the SAMURAI spectrometer2) . The unbound statesof 17 C were produced using the one-neutron knockout reaction of 18 C. The 18 C beam was provided by
BigRIPS. The beam intensity was typically 2300 pps
with the energy of 250 MeV/nucleon under the momentum acceptance of ±3%. Particle identification of
the beam was carried out by employing the Bρ-TOF∆E method with a mass resolution of A/∆A = 770
at 1 sigma. The unbound states of 17 C populated by
one-neutron knockout of 18 C on a carbon reaction target with a thickness of 1.8 g/cm2 immediately decays
into a 16 C fragment and a neutron. The particle identification of this fragment was also carried out using
the Bρ-TOF-∆E method with a mass resolution ofA/∆A = 250 at 1 sigma. The identification of thestates of the 16 C fragment subsequent to the decay
was carried out on the basis of γ-n coincidence. The
de-excitation γ-rays in 16 C were detected by a γ-ray
detector array DALI23) , while neutrons were detectedby the neutorn detector array NEBULA consisting of
neutron detectors (NEUT) and charged-particle vetodetectors (VETO). For NEUT, the timing resolution
was 270 ps in a flight length of approximately 11 m.
The relative energy (Erel ) of 17 C was reconstructedusing the momentum vectors of the 16 C fragment andthe neutron. To determine the positions of the resonances, responses were generated using a Monte Carlosimulation that considers the beam characteristics, reaction mechanism, and detector resolutions. From thesimulation, the Erel resolution was evaluated as ∆Erel

15
10
5
0

0

1

2

3

4

Erel (MeV)

5

6

7

Fig. 1. Preliminary spectrum of the relative energy of 17 C.
The black solid line represents the result of the overall
fit by three responses (red solid lines) and a Maxwellian
background (a blue solid line).

√= 0.4 Erel MeV in FWHM.
A preliminary result of the fitting to the experimental spectrum with three responses and a Maxwellian
background is shown in Fig. 1 where resonances at
Erel = 0.58(3), 2.01(2), and 3.30(6) MeV are observed.
In this measurement, the resonance at E rel = 0.58(3)exhibited a correlation with a gamma line at 1.72(12)MeV, which corresponds to the 2+ state of 16 C4) .
Consequently, the three resonances correspond to excited states at 3.04(12), 2.75(3), and 4.04(6) MeV.
The excited states at 2.75(3) and 4.04(6) MeV are
likely to correspond to the states at 2.71(2) and 3.93(2)MeV, respectively, which have been observed in the βdelayed neutron measurement5) . Further analysis involving a comparison with Glauber model calculations
is in progress to investigate the orbital angular momentum and spin-parity of the observed resonances.
References
1) M. Wang, G. Audi, A. H. Wapstra, F. G. Kondev, M.
MacCormick, X. Xu, and B. Pfeiffer: Chin. Phys. C 36,
1603 (2012).
2) T. Kobayashi et al.: Nucl. Instrum. Methods Phys. Res.
B 317, 294 (2013).
3) S. Takeuchi et al.: Nucl. Instrum. Methods Phys. Res.
A 763, 596 (2014).
4) D. R. Tilley et al.: Nucl. Phys. A 564, 1 (1993).
5) H. Ueno et al.: Phys. Rev. C 87, 034316 (2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Detailed analysis of tracking detectors for SAMURAI08 experiment
S. Koyama,∗1,∗2 H. Otsu,∗2 for SAMURAI08 collaboration
We performed an experiment at SAMURAI tosearch for α-cluster levels in 16 C.1) The levels were
populated by bombarding a 16 C secondary beam on aliquid He target. The excitation energies were reconstructed from the invariant mass of the 16 C∗ → 12 Be +4
He decay channel by measuring their four momenta.
The four momenta were deduced from timing measurements and the tracking of drift chambers (DCs). For
these DCs, the tracking eﬃciency and position resolution depend on the energy loss in the detector, which
depends on the element number (Z) of penetrating
fragments. In order to determine the four momenta
accurately, the parameters for tracking should be separately optimized for each Z.
Figure 1 shows a particle identiﬁcation (PID) plot ofreaction products measured using the plastic scintillator array HODF and HODP.2) Note that 1 scintillator
out of 32 of the array on which the secondary beam
directly hits with an intensity of 2 × 105 is excluded.

Fig. 1. PID plot of reaction products. The vertical axis
shows the mean light output and the horizontal axis
shows the time of flight (TOF) between the plastic scintillator placed upstream of the target and HODF andHODP.

DCs consist of more than 3 planes with diﬀerent
kinds of wire orientations. FDC2,2) which was placeddownstream of the SAMURAI magnet2) (B = 2.3 T
at the center), has 6 X (vertical, 0◦ ), 4 U (+30◦ ) and4 V (−30◦ ) planes. The drift length on each plane ismeasured and the trajectories of fragments for one axial direction, x = a0 + a1 z, are reconstructed by ﬁtting
a linear function, where x is the position orthogonal tothe beam line, a0 and a1 are linear ﬁtting parametersand z is the position along the beam line. The x positions of fragments in the k-th plane of a DC xk are deduced from the time-to-digital converter (TDC) spectrum with a space-time conversion (STC) function,
which converts time information to drift length. The
STC function is ﬁrst obtained by integrating the TDC
spectrum and is corrected in response to the result of∗1∗2

Fig. 2. (a) The optimized STC functions for Z = 2 (red)and Z = 4 (green) fragments. (b) xk − rk correlation
with the optimized STC function. (c) xk − rk correlation with an unoptimized STC function.

tracking. Figure 2 (a) shows the two STC functions
optimized for Z = 2 and Z = 4 fragments. The diﬀerence between the two functions is clear. The residue rk
is deﬁned as rk = xk −x′k , where x′k = a0 +a1 zk and zk
is the z position of the k-th plane. Figs. 2 (b) and (c)show how xk − rk correlation changes when a diﬀerent
STC function is applied for tracking. The positions arewell reconstructed when the optimized STC function isapplied (Fig. 2 (b)) while they systematically deviate
from the case in which an inappropriate STC function
is applied (Fig. 2 (b)).
The position resolution of the k-th plane of a DC ∆xk
can be evaluated using the standard deviation of theresidue of the plane ∆rk as follows:√
Szz − 2Sz zk + S1 zk2∆x,(1)∆rk = 1 −D∑∑
∑ 2
where S1 =k 1, Sz =k zk , Szz =k zk , and
D = S1 Szz − Sz2 . It is assumed that ∆xk has thesame value ∆x in the same wire-oriented planes of a
DC to deduce Eq. 1. Table 1 summarizes the position
resolutions of X, U, and V planes with the optimized
STC function for each Z. The position resolution of
FDC2 is 120 µm2) for Z = 6. Note that the value ofthe high voltage (2.4 kV) is not optimized for one Z tomeasure fragments with diﬀerent Z in this experiment.
Table 1. Resolution of each plane of FDC2

Wire orientation
X
U
V

Resolution (µm)
Z=2
342
255
257

Resolution (µm)
Z=4
309
195
199

References
1) H. Otsu et. al.: RIKEN Accel. Prog. Rep. 47, xx (2014).
2) T. Kobayashi et. al.: Nucl. Instrum. Meth. B 317 (2013).

Department of Physics, University of Tokyo
RIKEN Nishina Center- 46 -

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Fission Barrier Studies of Neutron-Rich Nuclei via the (p,2p)
Reaction: Status of NP1306-SAMURAI-14 Experiment
D. Mücher,∗1,∗2 S. Reichert,∗1,∗2 M. Sako,∗2 M. Sasano,∗2 A. Andreyev,∗3 T. Aumann,∗4 H. Baba,∗2
M. Böhmer,∗1 M. Dozono,∗5 N. Fukuda,∗2 R. Gernhäuser,∗1 W. F. Henning,∗6 K. Hirose,∗3∗2
N. Inabe, D. Kameda,∗2 N. Kobayashi,∗2 T. Kobayashi,∗7 Y. Kondo,∗8 T. Kubo,∗2 Y. Kubota,∗2,∗5 R. Lang,∗1
L. Maier,∗1 Y. Matsuda,∗9 S. Mitsuoka,∗4 T. Motobayashi,∗2 T. Nakamura,∗8 N. Nakatsuka,∗9 S. Nishimura,∗2
I. Nishinaka,∗3 K. Nishio,∗3 R. Orlandi,∗3 H. Otsu,∗2 V. Panin,∗2 S. Sakaguchi,∗2 H. Sato,∗2 Y. Shimizu,∗2
L. Stuhl,∗2 T. Sumikama,∗2 H. Suzuki,∗2 H. Takeda,∗2 Y. Togano,∗2 T. Uesaka,∗2 J. Yasuda,∗2 K. Yoneda,∗2
and J. Zenihiro∗2
The aim of NP1306-SAMURAI-14 is to experimentally determine fission barrier heights in neutron-richnuclei ”north east” of doubly-magic 208 Pb using RIB’s
at RI Beam Factory (RIBF) at RIKEN. The results
will drastically improve our experimental knowledge
on fission barriers away from stability which is poorat present. Neutron-rich nuclei around Z ≈ 82 andN > 126 are good subjects to be studied because theisospin dependence of fission barriers in those nuclei arequite controversial: The Rotating Liquid Drop Model
predicts an increase of barrier heights with neutron
number, while modern, more microscopic fission models make completely different and, depending on themodel, quite varying behaviors (see e.g.1) and references therein). The behavior of fission barriers towards neutron-rich nuclei has a direct impact on the
r-process2) , which is believed to produce about half ofthe stable heavy elements in the universe.
The basic idea is to use the quasifree (p,2p) reaction
in inverse kinematics to excite the nuclei of interest.
Heavy neutron-rich nuclei provided at the RI Beam
Factory bombard a hydrogen target and measurements
of proton four-momenta tells us an excitation energyof the neutron-rich isotopes. In case that fission takes
place, the two fission fragments are detected and analyzed with the large-acceptance SAMURAI spectrometer3) . This allows to extract a threshold energy forthe fission process.
For this experiment, heavy secondary beams must
be produced from a primary 238 U beam and identified
using BigRIPS. This is a difficult task as the secondary
fragments after the production target have very similar
A/Q ratios compared to the primary beam, which has
to be stopped in the beam dump after the D1 magnet. A first test was performed from the BigRIPS
team in autumn 2014 to produce neutron-rich Polonium (Z=84) nuclei (N. Inabe et al. in the present
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

Physics Department E12, Technical University Munich
RIKEN Nishina Center
ASRC JAEAIKP, Technical University Darmstadt
Center for Nuclear Studies, University of Tokyo
Physics Devision, Argonne National Laboratory
Department of Physics, Tohoku University
Department of Physics, Tokyo Institute of Technology
Department of Physics, Kyoto University

volume of this APR).
In April 2014, we performed a one day test at the
SAMURAI setup using a stable 238 U beam. The experimental setup was basically identical to the one used forexperiment NP1306-SAMURAI-17 (M. Sasano in thepresent volume of this APR). To keep the beam intensity below 5 · 104 pps in the SAMURAI area, the 238 U
beam was produced as a secondary beam, using a 5 mm
Be production target. The best setting was found bychoosing the Q=87+ charge state after the target, followed by a Q=90+ charge state after a thin aluminum
degrader. In this way, 40 kHz beam rate after BigRIPS
was achieved using 0.75 pnA primary beam intensity.
The beam purity was better then 98 %. The beam hit
a 1 cm liquid hydrogen target. A multiplicity triggerof the WINDS array (see reports of the present volume of the APR) was used to trigger on possible (p,2p)
events close to the target. These data are currently analyzed by S. Reichert. Indeed, based on time-of-flightand QDC information, coincident protons follow the
expected kinematics of quasi-free scattering. However,in order to achieve the desired missing mass resolution,a new high-resolution proton-detection system is currently under development in collaboration of the TU
Munich and RIKEN. The status of the development of
this setup can be found in the report of S. Reichert etal. in the present volume of this APR.
The test experiment also gives first results about
the response and performance of various detectors of
the SAMURAI setup on high-Z beams. The mass andcharge resolution for the identification of fission fragments is currently analyzed by M. Sako (see report in
the present volume of this APR). Furthermore the data
allow us to study the tracking efficiency of coincident
fission fragments. A first analysis about the identification of fission fragments using the FDC1 detector wasdone by S. Reichert (see report in the present volumeof this APR).
References
1) P. Moeller et al.: Phys. Rev. C 79, 064304 (2009).
2) G. Martinez-Pinedo et al.: Prog. Part. Nucl. Phys. 59(2007) 199-205.
3) T. Kobayashi et al.: Nucl. Inst. Meth. B 317, 294304(2013).

- 47 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Identification of fission fragments from tracks measured by the FDC1
S. Reichert,∗1,∗2 M. Sako,∗2 M. Sasano,∗2 D. Mücher,∗1,∗2 A. Andreyev,∗3 T. Aumann,∗4 H. Baba,∗2
M. Böhmer,∗1 M. Dozono,∗5 N. Fukuda,∗2 R. Gernhäuser,∗1 W. F. Henning,∗6 K. Hirose,∗3∗2
N. Inabe, D. Kameda,∗2 N. Kobayashi,∗2 T. Kobayashi,∗7 Y. Kondo,∗8 T. Kubo,∗2 Y. Kubota,∗2,∗5 R. Lang,∗1
L. Maier,∗1 Y. Matsuda,∗9 S. Mitsuoka,∗4 T. Motobayashi,∗2 T. Nakamura,∗8 N. Nakatsuka,∗9 S. Nishimura,∗2
I. Nishinaka,∗3 K. Nishio,∗3 R. Orlandi,∗3 H. Otsu,∗2 V. Panin,∗2 S. Sakaguchi,∗2 H. Sato,∗2 Y. Shimizu,∗2
L. Stuhl,∗2 T. Sumikama,∗2 H. Suzuki,∗2 H. Takeda,∗2 Y. Togano,∗2 T. Uesaka,∗2 J. Yasuda,∗2 K. Yoneda,∗2
and J. Zenihiro∗2b=a1 + a2tanθ1 + tanθ2(1)where θ1/2 are the angles of the two fission fragments
1 and 2 in respect to the beam axis and a1/2 are definedas their most probable intersection point with the firstlayer of the FDC1.
The results for two 1/2 h runs with each with the
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

Technical University Munich
RIKEN Nishina Center
ASRC JAEA
Technical University Darmstadt
Center for Nuclear Studies, University of Tokyo
ANL
Tohoku University
Tokyo Institute of Technology
Kyoto University- 48 -

300

hLayervsXges60

hLayervsXges12

200

100

100

0

-100

0

-100

-200
-300
0

Distance to the beam axis [mm]Distance to the beam axis [mm]

300

200

-200

2

4

6

8

10

12

14

# of Layer of the FDC 1

-300
0

(a)

2

4

6

8

10

12

14

# of Layer of the FDC 1(b)Fig. 1. Online plot of typical tracks observed in the FDC1

6000

Entries 113279

5000
4000

# of counts

filled target or with the empty one are shown in Fig.
2(a) and (b). In both cases the maximum of the verybroad peak is in good agreement with the real distanceto the target of 2215 mm. The sharp peak at b ≈4600 mm also appears in both spectra but it is not yet
understood. The peak in the case of the empty run
can be considered as interactions of the beam with thetarget foil. The main and important difference is thenumber of events which drops down from over 100.000
to ∼5000 entries removing the liquid hydrogen fromthe target.
# of counts

The purpose of the experiment NP1306-SAMURAI14
is to characterize parameters of fission of neutron richheavy nuclei, like the fission barrier heights and thefragment distributions. As a first step, we performedin April 2014 a 24-hour beamtime experiment using238
U as primary beam at 250 MeV/u and an intensityof 5×104 pps. A liquid hydrogen target in the setup of
NP1306-SAMURAI17 was used as a secondary target.
In this report we present a method to identify fission fragments by the forward drift chamber 1 (FDC1)
which is positioned upstream in front of the SAMURAI spectrometer. In the beam direction, the FDC1
has 14 layers. For each layer the positions of the particles passing the active volume are determined. The
most likely trajectory is defined as the composition of
the available positions in all layers which has the smallest χ2 . When two fission fragments are incident, there
are two possible positions for all the layers and theirtracks are given by the two smallest χ2 values.
In Fig. 1 we show examples of trajectories throughthe 14 layers in beam axis of the FDC1. In Fig. 1(a)the number of possible positions of the particles in eachlayer is one. Hence the track corresponds to a beamlike particle, showing no fission reaction is induced.
The situation in Fig. 1(b) is totally different where
each layer has two entries and two tracks with a large
gap can be reconstructed. Such events are interpreted
as two particles crossing the FDC1 at the same time.
For these cases the distance b between their intersection points and the first layer of the FDC1 in beam
direction is obtained by

3000
2000
1000
00

1000

2000

3000

4000

5000

6000

7000

8000

9000 10000

240
220
200
180
160
140
120
100
80
60
40
20
00

Entries

5332

1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Distance b to the FDC 1 [mm]Distance b to the FDC 1 [mm]

(a)

(b)

Fig. 2. Intersection point of two tracks of the FDC1 in
respect to the beam axis. (a) is the result where thetarget was mounted, in (b) there was no liquid hydrogen
between the target foils.

This method seems promising for a fast and reliable way to identify fission stemming from reactions
inside the target. However the uncertainty in the reconstructed vertex position b is very large, σ ∼ 600
mm. In the future this might be improved, e.g., by including the position of the incoming beam by the beamdrift chambers. A precise beam position and incident
angle is also needed for determining the A/Q value ofthe fission fragments in the downstream part of the
SAMURAI spectrometer.

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Analysis status of the experiment on fission associated with the(p,2p) reaction with 238 U beam
M. Sako,∗1 S. Reichert,∗1,∗2 M. Sasano,∗1 D. Mücher,∗2 A. Andreyev,∗3 T. Aumann,∗4 H. Baba,∗1 M. Böhmer,∗2
M. Dozono,∗5 N. Fukuda,∗1 R. Gernhäeuser,∗2 W. F. Henning,∗6 K. Hirose,∗3 N. Inabe,∗1 D. Kameda,∗1
N. Kobayashi,∗1 T. Kobayashi,∗7 Y. Kondo,∗8 T. Kubo,∗1 Y. Kubota,∗1,∗5 R. Lang,∗2 L. Meier,∗2 Y. Matsuda,∗9
S. Mitsuoka,∗4 T. Motobayashi,∗1 T. Nakamura,∗8 N. Nakatsuka,∗1,∗9 S. Nishimura,∗1 I. Nishinaka,∗3
K. Nishio,∗3 R. Orlandi,∗3 H. Otsu,∗1 V. Panin,∗1 S. Sakaguchi,∗7 H. Sato,∗1 Y. Shimizu,∗1 L. Stuhl,∗1
T. Sumikama,∗1 H. Suzuki,∗1 H. Takeda,∗1 Y. Togano,∗8 T. Uesaka,∗1 J. Yasuda,∗1,∗10 K. Yoneda,∗1 and
J. Zenihiro∗1∗1

RIKEN Nishina Center
Technical University Munich∗3 ASRC JAEA
∗4 Technical University Darmstadt∗5 Center for Nuclear Studies, University of Tokyo∗6 ANL∗7 Tohoku University∗8 Tokyo Institute of Technology∗9 Department of Physics,Kyoto University∗10 Department of Physics,Kyushu University

(a)

(b)

Number of Counts

103
2

10

10
1

(c)
10

1
0

2000
ADC of ID = 1 in HODS (ch)4000

Fig. 1. (a)Layout of the experimental setup of the SAMURAI downstream detectors. The energy deposition(ADC) of slat ID = 1 in the HODS without (b) andwith (c) multiplicity gate for slat ID = 1 and 6.
4000

(a)
ADC of ID = 6 in TED (ch)4000

ADC of ID = 1 in TED (ch)Our experimental program NP1306-SAMURAI141)
is the ﬁrst attempt to determine ﬁssion barrier heightfor neutron-rich heavy nuclei such as 212 Bi or 213 Po.
In this experiment, we use missing mass spectroscopy
to determine the excitation energy of the ﬁssioning nucleus produced by the (p,2p) reaction in combination
with the SAMURAI spectrometer.
In this report, we show preliminary results of data
analysis for the test experiment performed using a primary 238 U beam with a typical intensity of 5×104 pps
and at a beam energy of 250A MeV.Liquid hydrogenwith a 10-mm thickness was used as the secondary target to study the proton induced (p,2p) reaction.
Figure 1(a) shows the layout of the experimental
setup in the downstream part of the SAMURAI spectrometer2,3) : the forward drift chamber 2 (FDC2),
the ion chamber for fragment (ICF), the hodoscope(HODS), and the total energy detector (TED). HODS
has seven slats of plastic scintillators. Here, we label the slats with IDs from 0 (lower rigidity side) to 6
(higher rigidity side). TED is an array of 8 × 4 CsI
crystals, labeled from 0 to 7 corresponding to HODS
for the second row from the bottom side.
Figure 1(b) shows the energy deposition for the slat
ID = 1 in HODS without any constraint on the HODS
multiplicity, while Fig. 1(c) is constrained by multiplicity = 2. A peak around 3000 ch in Fig. 1(b)corresponds to 238 U beam, which disappears with themultiplicity gate. A bump structure around 1000 ch
corresponds to ﬁssion fragments in Fig. 1(c).
Figure 2 shows two-dimensional histograms of the∆E-E correlation for ﬁssion fragments. Slats ID = 1(left) and 6 (right) in HODS are selected for ∆E, while
the crustal ID = 1 and 6 are selected for total E. The
multiplicity gate is applied to Fig. 2 (b) and (d). The
test experiment was successful to measure the ﬁssion
fragments associated with the (p,2p) reaction.

2000

4000

(b)

2000

0
0

2000
ADC of ID = 1 in HODS (ch)

4000

(c)

2000

4000

(d)

2000

0
0

2000
ADC of ID = 6 in HODS (ch)4000

Fig. 2. ∆E-E correlation for each ﬁssion fragment with
ADC between the TED and HODS with slat ID = 1(left) and 6 (right) without (top) and with (bottom)
the multiplicity gate.

Further analysis will be performed to establish theidentiﬁcation of mass and charge number for each ﬁssion fragment.
References∗21) D. Mücher, M. Sasano, M. Sako et al.: Proposal RIBF
NP-PAC- 12 Fission Barrier Studies of Neutron-Rich
Nuclei via the (p,2p) Reaction (2013).
2) T. Kobayashi et al.: Nucl. Instr. Meth. B 317, 294,(2013).
3) SAMURAI Magnet and Detectors: http://ribf.
riken.jp/SAMURAI/index.php?ChargedParticleDetector- 49 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Study of Neutron-Proton Correlations & 3N Forces in 12 C
H. N. Liu,∗1,∗2 J. Lee,∗1,∗3 H. Otsu,∗1 Y. Kondo,∗4 S. Takeuchi,∗1 Y. Togano,∗4 H. Baba,∗1 N. Chiga,∗5
P. Doornenbal,∗1 N. Fukuda,∗1 J. Gibelin,∗6 J. Hwang,∗7 T. Isobe,∗1 T. Kawabata,∗8 N. Kobayashi,∗9
T. Kobayashi,∗5 K. Kusaka,∗1 S. Leblond,∗6 Y. Matsuda,∗8,∗13 M. Matsushita,∗10 R. Minakata,∗4
T. Motobayashi,∗1 T. Murakami,∗5 K. Muto,∗5 T. Nakamura,∗4 N. Nakatsuka,∗8 A. Navin,∗11 M. Nishimura,∗1
S. Ogoshi,∗4 J. Ohnishi,∗1 S. Sakaguchi,∗12 H. Sakurai,∗1 M. Sasano,∗1 H. Sato,∗1 Y. Satou,∗7 K. Sekiguchi,∗5
Y. Shimizu,∗1 T. Sumikama,∗5 Y. Wada,∗5 K. Yoneda,∗1 and J. Zenihiro∗1∗1

RIKEN Nishina Center
School of Physics and State Key Laboratory of Nuclear
Physics and Technology, Peking University∗3 Department of Physics, The University of Hong Kong
∗4 Department of Physics, Tokyo Institute of Technology∗5 Department of Physics, Tohoku University∗6 LPC, Caen
∗7 Department of Physics, Seoul National University∗8 Department of Physics, Kyoto University∗9 Department of Physics, The University of Tokyo∗10 CNS, The University of Tokyo∗11 GANIL, CEA/DSM-CNRS/IN2P3∗12 Department of Physics, Kyushu University∗13 CYRIC, Tohoku University∗2- 50 -

7h2

6Charge Number Z

The study of neutron-proton (np) correlations in nuclei is very important to understand the nuclear structure. Direct two-nucleon knockout reactions oﬀer apowerful tool for quantitative measurements of the np correlations in N = Z nuclei.1,2) The measured inclusive two-nucleon knockout cross sections3,4) show
signiﬁcant enhancement of np (T = 0 & 1) over nn
and pp (T = 1) correlations in 12 C. The shell-model
calculation for the two-nucleon overlaps within the pshell can reproduce the inclusive cross sections for likenucleon pair removal, but underestimates the np-pairremoval cross section by approximately a factor of two.1) This discrepancy implies insuﬃcient descriptionof the T = 0 np interactions in the shell-model wave
functions. A recent calculation using the no-core shellmodel that exploits modern chiral eﬀective ﬁeld theory NN+3N interactions2) suggests that the ﬁnal-stateexclusive np-knockout cross sections from 12 C to the
T = 0 states can provide an immediate test of the np
correlations (particularly in their T = 0 component) and three-nucleon forces. To investigate the natureof these forces, we therefore measured γ-residue coincidence to extract the ﬁnal-state-exclusive np- andpp-removal cross sections from 12 C to 10 B and 10 Be.
The experiment was carried out at RIBF. The secondary 12 C beam (presently not available as the primary beam for SRC-use experiments) was produced byfragmentation of an 18 O primary beam at 250 MeV/u
using a 5-mm thick Be target. The ions of interest
were selected using the BigRIPS fragment separator5)
by measuring the energy loss (∆E ) and time of ﬂight(TOF) with plastic scintillators at the intermediate foci F3 and F13. The incident angle and position of thebeam on a 1.879-g/cm2 thick Be target were determined by two drift chambers, BDC1 and BDC2. The
target was surrounded by the DALI2 γ-ray spectrom-

10

102

B

10

5

Be
10

4
3
1.6

1.8

2

2.2

Mass-to-Charge Ratio A/Z

2.4

2.6

1

Fig. 1. Particle identification after the secondary target.

eter.6) One hundred and ﬁfty-nine crystals of DALI2 were employed with an azimuthal angular coverage
from 25◦ to 154◦ . The mid-target energy of 12 C wasapproximately 190 MeV/u. Reaction products weretransported to the SAMURAI spectrometer7) and identiﬁed with the Bρ-∆E -TOF method. The magnetic rigidity Bρ was determined from the measured
positions at the forward drift chambers, FDC1 andFDC2. ∆E and TOF were measured by using the plastic scintillator hodoscopes, HODF and HODP. Fig. 1
shows the particle identiﬁcation of reaction residues.
It should be noted that the reaction channels of interest were measured simultaneously because of the large
acceptance of SAMURAI.
The preliminary ratio of inclusive np- to pp-removal
cross sections was obtained, which is consistent withthe previous result within errors.3) Currently, the γray spectrum analysis is ongoing. Further, the partial
cross sections will be extracted.
References
1) E. Simpson and J. A. Tostevin: Phys. Rev. C 83, 014605(2011).
2) E. Simpson et al.: Phys. Rev. C 86, 054609 (2012).
3) J. M. Kidd et al.: Phys. Rev. C 37, 2613 (1988).
4) D. L. Olson et al.: Phys. Rev. C 28, 1602 (1983).
5) T. Kubo et al.: Prog. Theor. Exp. Phys. 2012, 03C003(2012).
6) S. Takeuchi et al.: Nucl. Instr. Meth. A 763, 596 (2014).
7) T. Kobayashi et al.: Nucl. Instr. Meth. B 317, 294(2013).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Measurement of the 132 Sn(p, n) reaction at 270 MeV/nucleon
M. Sasano,∗1 J. Yasuda,∗2 R.G.T. Zegers,∗3 H. Baba,∗1 W. Chao,∗1 M. Dozono,∗1 N. Fukuda,∗1 N. Inabe,∗1
T. Isobe,∗1 G. Jhang,∗1,13 D. Kamaeda,∗1 T. Kubo,∗1 M. Kurata-Nishimura,∗1 E. Milman,∗1 T. Motobayashi,∗1
H. Otsu,∗1 V. Panin, ∗1 W. Powell, ∗1 M. Sako, ∗1 H. Sato,∗1 Y. Shimizu,∗1 L. Stuhl,∗1 H. Suzuki,∗1 T. Suwat,∗1
H. Takeda,∗1 T. Uesaka,∗1 K. Yoneda,∗1 J. Zenihiro,∗1 T. Kobayashi,∗4 T. Sumikama,∗4 T. Tako,∗4
T. Nakamura,∗5 Y. Kondo,∗5 Y. Togano,∗5 M. Shikata,∗5 J. Tsubota,∗5 K. Yako,∗6 S. Shimoura,∗6 S. Ota,∗6
S. Kawase,∗6 Y. Kubota,∗6 M. Takaki,∗6 S. Michimasa,∗6 K. Kisamori,∗6 C.S. Lee,∗6 H. Tokieda,∗6
M. Kobayashi,∗6 S. Koyama,∗7 N. Kobayashi, ∗7 H. Sakai,∗8 T. Wakasa,∗2 S. Sakaguchi,∗2 A. Krasznahorkay,∗9
T. Murakami, ∗10 N. Nakatsuka, ∗10 M. Kaneko, ∗10 Y. Matsuda, ∗11 D. Mucher, ∗12 S. Reichert, ∗12 D. Bazin,∗3
and J.W. Lee∗13
Among the collective modes1) , the Gamow-Teller(GT) giant resonance is an interesting excitation mode.
It is a 0h̄ω excitation characterized by the quantumnumber changes of orbital angular momentum (∆L =0), spin (∆S = 1), and isospin (∆T = 1), and induced by the transition operator στ . In the stable
nuclei in medium or heavier mass regions (A > 50),
the collectivity in this mode exhibits the GT giant resonance (GTGR), which gives information that is critically important for understanding the isovector partof the effective nucleon-nucleon interaction2) and thesymmetry potential of the equation of the state3) .
The goal of the NP1306-SAMURAI17 experiment
performed in Spring 2014 was to extract the GT andspin-dipole (SD) transition strengths over a wide excitation range covering their giant resonances on the key
doubly magic nucleus 132 Sn via the charge-exchange(p, n) reaction at 270 MeV/nucleon in inverse kinematics. This is an essential step toward establishingcomprehensive theoretical models for nuclei situatedbetween 78 Ni and 208 Pb; at the same time, this is amilestone for extending the research on various phenomena in stable nuclei such as GT quenching, andnuclear weak processes of astrophysical interest, to theneutron-rich region far from the beta stability. An experimental technique based on the missing mass spectrocopy4,5) was employed to reconstruct the excitationenergy spectra for the reaction.
In the experiment, a secondary beam of 132 Sn at
270 MeV/nucleon was produced through an abrasionfission reaction with a 345 MeV/nucleon primary beamof 238 U. The resulting cocktail beam had a total intensity of 1.4×104 pps, containing 132 Sn with a purity of
45%. The particle identification (PID) was performed

Fig. 1. Top view of the experimental setup around the
SAMURAI spectrometer.

on an event-by-event basis by measuring the energy
loss in the ionization chamber at the F7 focal plane,
and the magnetic rigidity and the time of flight of thebeam particles in the BigRIPS spectrometer.
Figure 1 shows a top view of the experimental setup
around the SAMURAI spectrometer6) . The secondary
beam was impinged on a liquid hydrogen target7) before the entrance of the SAMURAI magnet. The recoil neutrons were detected by using the Wide-angle
Inverse-kinematics Neutron Detectors for SHARAQ(WINDS) surrounding the target. The PID of thereaction residues was performed with the SAMURAI
spectrometer and the decay neutrons from the residues
were detected with the NEBULA. Detailed reports on
the WINDS setup, the PID analysis in the SAMURAI
spectrometer, and the NEBULA DAQ based on a fast
clear mode are given in other reports in the current
volume of the APR. The analysis is in progress. In
preliminary results, the kinetic curves corresponding
to the (p, n) reaction are clearly observed; this indicates that the experiment worked as planned.
References∗1

RIKEN Nishina Center∗2 Department of Physics,Kyushu University∗3 NSCL Michigan State University∗4 Department of Physics, Tohoku University∗5 Tokyo Institute of Technology∗6 CNS, University of Tokyo∗7 University of Tokyo∗8 ULIC, RIKEN Nishina Center∗9 MTA, Atomki, Debrecen, Hungary∗10 Kyoto University∗11 Konan University∗12 Technical University Munich∗13 Department of Physics, Korea University

1) M. N. Harakeh and A. M. van der Woude: Giant Resonances (Oxford University Press, Oxford, 2001).
2) S. Fracasso and G. Colo: Phys. Rev. C 72, 064310(2005).
3) P. Danielewicz: Nucl. Phys. A 727, 233 (2003).
4) M. Sasano et al.: Phys. Rev. Lett. 107, 202501 (2011).
5) M. Sasano et al.: Phys. Rev. C 86, 034324 (2012).
6) T. Kobayashi et al.: Nucl. Inst. Meth. B 317, 294-304(2013).
7) M. Kurata-Nishimura et al.: RIKEN Accel. Prog. Rep.
45, 122 (2012).

- 51 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Experimental study on neutron-neutron correlationin Borromean nuclei via the (p, pn) reaction
at intermediate energy with the SAMURAI spectrometer
Y. Kubota,∗1,∗2 A. Corsi,∗3 G. Authelet,∗3 H. Baba,∗2 C. Caesar,∗4 D. Calvet,∗3 A. Delbart,∗3 M. Dozono,∗1
J. Feng,∗5 F. Flavigny,∗6 J.-M. Gheller,∗3 J. Gibelin,∗7 A. Gillibert,∗3 K. Hasegawa,∗8 T. Isobe,∗2 Y. Kanaya,∗9S. Kawakami,∗9 D. Kim,∗10 Y. Kiyokawa,∗1 M. Kobayashi,∗1 N. Kobayashi,∗11 T. Kobayashi,∗8 Y. Kondo,∗12
Z. Korkulu,∗13 S. Koyama,∗11 V. Lapoux,∗3 Y. Maeda,∗9 F. M. Marqués,∗7 T. Motobayashi,∗2 T. Miyazaki,∗11
T. Nakamura,∗12 N. Nakatsuka,∗14,∗2 Y. Nishio,∗15 A. Obertelli,∗3 A. Ohkura,∗15 N. A. Orr,∗7 S. Ota,∗1
H. Otsu,∗2 T. Ozaki,∗12 V. Panin,∗2 S. Paschalis,∗4 E. C. Pollacco,∗3 S. Reichert,∗16 J.-Y. Roussé,∗3 A. Saito,∗12
S. Sakaguchi,∗15 M. Sako,∗2 C. Santamaria,∗3 M. Sasano,∗2 H. Sato,∗2 M. Shikata,∗12 Y. Shimizu,∗2
Y. Shindo,∗15 L. Stuhl,∗2 T. Sumikama,∗8 M. Tabata,∗15 Y. Togano,∗12 J. Tsubota,∗12 T. Uesaka,∗2 Z. Yang,∗5
J. Yasuda,∗15 K. Yoneda,∗2 and J. Zenihiro∗2
Dineutron correlation is one of the symbolic phenomena expected to appear in neutron drip-line nuclei.
It has been studied using different approaches, such as
the transfer reaction and the break up reaction. However, currently available data seem to be insufficient tostudy the neutron-neutron correlation in terms of (i)the decomposition of high-angular-momentum components, (ii) the extraction of a core excitation, (iii) andthe effect of final state interactions (FSIs).1) In thisstudy, (i) the MINOS2) was used for higher luminosity, (ii) γ rays were detected to tag the core excitation,(iii) and the quasi-free (p, pn) reaction was employed
to minimize the FSI.
The experiment was performed at RIBF. Secondary
beams were produced and separated by the BigRIPS,
by projectile fragmentation of a 48 Ca primary beam at
345 MeV/nucleon with a typical intensity of 400 particle nA in a 20-mm or a 30-mm thick Be target. They
were detected and identified using plastic scintillators
at the focal planes F3, F5, F7, and F13 and multi-wiredrift chambers (MWDCs) at F13 (BDC). The sufficient number of beam particles required, which arelarge enough as indicated, is listed in Table 1. The
ratio of 3 H in the beam at F13 was typically 14%.
Figure 1 shows a schematic view of the experimental setup. The reaction point in a 15-cm thick liquid hydrogen target was determined from the tracks ofcharged particles reconstructed from signals from theTable 1. Number of beam particles on the target. ∆p/p
denotes the momentum acceptance of the BigRIPS.
Energy
Beam
11
Li
14
Be
17
B
19
B

∆p/p Number of beam particles
Required Obtained
3.2 9.5 × 109 1.6 × 1010
3.2 1.8 × 109 2.3 × 109
3.2 8.6 × 107 1.6 × 109
3.2 4.3 × 107 9.8 × 106[MeV/nucleon] [%]

246
265
277
224

MINOS TPC and the BDC. The momenta of decay
neutrons, a knocked-out neutron, and a recoil proton
were determined respectively by the NEBULA,3) the
WINDS,4) and a recoil proton detector (RPD) setup
consisting of an MWDC and a plastic scintillator array.
The charged fragments were identified and momentum
analyzed by the SAMURAI spectrometer5) using thetwo MWDCs (FDC1 and FDC2) followed by the hodoscopes (HODF and HODP). γ rays emitted from theexcited core were detected by the DALI2.6)
Data analysis is currently in progress.
We thank the staff of accelerators and BigRIPS for
their effort and support. The theoretical support anddiscussion provided by Y. Kikuchi and K. Ogata arehighly appreciated.
A;B$

3-.*0$

0)>$

%$
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($

'$
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∗1

Center for Nuclear Study, University of Tokyo∗2 RIKEN Nishina Center∗3 CEA, Saclay∗4 Department of Physics, Technische Universität Darmstadt∗5 Department of Physics, Peking University∗6 IPN Orsay∗7 LPC Caen
∗8 Department of Physics, Tohoku University∗9 Department of Applied Physics, University of Miyazaki∗10 Department of Physics, Ehwa Womans University∗11 Department of Physics, University of Tokyo∗12 Department of Physics, Tokyo Institute of Technology∗13 MTA Atomki∗14 Department of Physics, Kyoto University∗15 Department of Physics, Kyushu University∗16 Department of Physics, Technische Universität München*#'789$:;<%9=$.4)5"1$

6*+&$

)*+$

*1"-2$

&&"#$

%$
ACB$

,-./0$

!"#$

!"#$

'$

Fig. 1. (a) Schematic view of the setup. Trajectories ofparticles are shown by arrows. (b) Schematic view ofthe MINOS surrounded by the DALI2.

References
1) Y. Kikuchi et al.: Phys. Rev. C87, 034606 (2013).
2) A. Obertelli et al.: Eur. Phys. Jour. A50, 8 (2014).
3) Y. Kondo et al.: RIKEN Accel. Prog. Rep. 45, 131 (2012).
4) K. Yako et al.: RIKEN Accel. Prog. Rep. 45, 137 (2012).
5) T. Kobayashi et al.: Nucl. Instr. Meth. B317, 294 (2013).
6) S. Takeuchi et al.: Nucl. Instr. Meth. A763, 596 (2014).

- 52 -

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Simulations for experimental studies of breakup reactions on
neutron-deficient isotopes relevant to the astrophysical rp-process
V. Panin,∗1 K. Yoneda,∗1 T. Uesaka,∗1 M. Kurokawa,∗1 T. Motobayashi,∗1 H. Otsu,∗1 Z. Elekes,∗2
A. Saastamoinen,∗3 and B. C. Rasco∗4
Our experimental program aims to investigate explosive nucleosynthesis in the rp-process occurring intype I X-ray bursts related to the most frequent typeof stellar explosions in the Galaxy1) . Indispensable
experimental information related to resonant structures in most sensitive proton-capture reactions withextremely neutron-deficient isotopes will result in theadvancement of the existing X-ray burst models by
providing a reliable nuclear-data input2) . A particularfocus of this research is to obtain spectroscopic information about proton-unbound excited states in 66 Se
and 58 Zn, which are expected to be involved in the
breakout from the waiting-point nuclei 64 Ge and 56 Ni
through the sequential two-proton capture3) . Singleneutron removal reactions from 67 Se and 59 Zn at 250
MeV/nucleon beam energy will be deployed to populate the states above one- and two-proton separationenergy in 66 Se and 58 Zn, respectively. Proton decay
in-flight of these highly excited states will then be measured in complete kinematics using High-Resolution(HR) 90◦ mode of the SAMURAI magnetic spectrometer4) in combination with the existing tracking systems
and the custom-designed Si-strip detectors for simultaneous detection and tracking of heavy ions and protons.
The conceptual design of the setup was examinedby detailed Geant4 simulations, aiming to achieve anexperimental resolution of about 100 keV (sigma) fora single resonance and a total detection efficiency
of at least 20%. The multidimensional parameterization and fit algorithm was developed to reconstruct
the total momentum of every particle and eventually
the proton-fragment relative energy Erel in their rest
frame. Compromising the resulting Erel resolution, detection efficiency, and construction cost, an appropriate experimental configuration was worked out after
systematical variation of the setup parameters such as
the geometry and location of the tracking detectors,
target thickness, magnetic field strength, etc. In addition, specific simulations were performed to study
the effect of δ-electrons on the measurements by the
Si trackers. In particular, the interference with a proton signal is studied together with various options tosuppress this effect by placing compact kick-off magnets between the Si-trackers, by adjusting the rela∗1
∗2
∗3
∗4

RIKEN Nishina Center
Institute for Nuclear Research, MTA Atomki
Cyclotron Institute, Texas A&M University
Department of Physics and Astronomy, Louisiana State University- 53 -

tive distance between the detectors, and/or by track
discrimination using track information in the protontracking system after the magnet. Based on thesestudies, the minimum requirements for the design ofa vacuum chamber for the Si trackers (i.e., its size, position relative to the target, and internal locations of
the detectors) were specified and the following conclusions were drawn:(1) The HR-mode is suitable for the heavy-ionproton (HI-p) experiments with beam energies
ranging from 200 to 250 MeV/nucleon.
(2) The value of acceptance×efficiency in the HRmode can be comparable to that of the standard“Day one” configuration (40% for one-proton
decay with Erel =1 MeV and beam energy of 250
MeV/nucleon).
(3) The HR-mode provides a better mass (momentum) resolution (1/1500) for heavy ions.
(4) The momentum resolution for protons and Erelresolution can be determined mainly by thestraggling in the target and by the position resolutions of the proton-tracking detectors.
(5) Erel resolution (sigma) of approximately 100
keV can be achieved at Erel =1 MeV alongwith the beam energies between 200 and 250
MeV/nucleon.
These results together with the LISE++ simulations
were used in the experimental proposal that was reviewed and approved by the 14th NP-PAC in June
2014. In a similar way, feasibility studies and experimental optimizations were performed for other potential HI-p experiments involving one- and two-proton
breakup of 9 C, 28 S, 32 Ar, 34 Ca, 35 K, 36 K and 36 Ca. A
common setup configuration for all HI-p experiments
was figured out and presented by the collaborators in
the 15th NP-PAC. Thus, we intend to perform a totalof four HI-p experiments in the next two years, ideallyas campaign-type measurements, which will provide
a wealth of experimental data that can significantly
enrich our knowledge and understanding of nucleosynthesis in type I X-ray bursts.
References
1) S. E. Woosley and R. E. Taam: Nature, Vol. 263 (1976),
101-103
2) A. Parikh, J. Jose, G. Sala, and C. Iliadis: Prog. Par.
and Nucl. Phys., Vol. 69 (2013), 225-223
3) O. Forstner et al.: Phys. Rev. C, Vol. 64 (2001), 045801
4) T. Kobayashi et al.: Nucl. Inst. Meth. B 317 (2013),
294-304

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Future plan to study light nuclei near the neutron drip line via
charge-exchange (p,n) reactions in inverse kinematics
L. Stuhl,∗1 M. Sasano,∗1 D. Ahn,∗1 H. Baba,∗1 W. Chao,∗2 M. Csatlós,∗3 Zs. Dombrádi,∗3 M. Dozono,∗4
N. Fukuda,∗1 B. Hong,∗5 N. Inabe,∗1 T. Isobe,∗1 G. Jhang,∗5 M. Kaneko,∗6 S. Kawase,∗4 K. Kisamori,∗4
M. Kobayashi,∗4 N. Kobayashi,∗7 T. Kobayashi,∗8 Y. Kondo,∗9 Z. Korkulu,∗1 S. Koyama,∗7 A. Krasznahorkay,∗3
T. Kubo,∗1 Y. Kubota,∗1,∗4 C. S. Lee,∗1,∗4 Y. Matsuda,∗10 S. Michimasa,∗4 E. Milman,∗11 T. Motobayashi,∗1
T. Murakami,∗6 S. Naimi,∗1 T. Nakamura,∗9 N. Nakatsuka,∗6 M. Niikura,∗7 M. Kurata-Nishimura,∗1
A. Ohkura,∗12 S. Ota,∗4 H. Otsu,∗1 V. Panin,∗1 S. Reichert∗13 S. Sakaguchi,∗12 H. Sakai,∗1 M. Sako,∗1
H. Sakurai,∗7 H. Sato,∗1 Y. Satou,∗14 M. Shikata,∗9 Y. Shimizu,∗1 S. Shimoura,∗4 Y. Shindo,∗12 H. Suzuki,∗1
M. Tabata,∗12 M. Takaki,∗4 H. Takeda,∗1 J. Timár,∗3 Y. Togano,∗9 H. Tokieda,∗4 J. Tsubota,∗9 T. Uesaka,∗1
Zs. Vajta,∗3 T. Wakasa,∗12 K. Yako,∗4 J. Yasuda,∗12 K. Yoneda∗1 and J. Zenihiro∗1
We plan to investigate the isovector response of
Li and 14 Be nuclei near the neutron drip line.
The variation of spin-isospin residual interaction andthe effect of spatial distribution of neutron skin or
halo on spin-isospin responses will be studied using
charge-exchange (p,n) reactions, at intermediate energies (260-280 MeV/nucleon) in inverse kinematics.
The Gamow-Teller (GT) and spin-dipole (SD) transitions including their giant resonances will be measured. Experimentally, the (p,n) reactions at intermediate beam energies can selectively excite GT states up
to high excitation energies in the final nucleus. Thereis a close proportionality between the cross-sections at
0◦ and the transition strengths B(GT) in these reactions1) . Therefore, the (p,n) reactions provide a powerful method to study the B(GT) distributions.
An experimental approach to study the variation of
the spin-isospin collectivity is the energy difference between the GT giant resonance (GTGR) and isobaric
analog state (IAS) over a wide range of (N-Z)/A. Measurements on stable nuclei show that the GTGR is afew MeV higher than the IAS. This difference gives access to spin-isospin residual interaction strength. However, it is expected to differ at high (N-Z)/A2,3) . According to predictions for (N-Z)/A values greater than0.3, the GTGR energy decreases below the IAS energy.
It is a compelling interest to obtain new experimental
data on nuclei with high (N-Z)/A along the neutron
drip line to clarify how the spin-isospin residual interaction strength changes and whether it is related also
to the skin or halo structures. With only two pioneer
11∗1

RIKEN Nishina Center
School of Physics, Peking University∗3 MTA Atomki, Debrecen, Hungary∗4 CNS, University of Tokyo∗5 Department of Physics, Korea University∗6 Division of Physics and Astronomy, Kyoto University∗7 Department of Physics, University of Tokyo∗8 Department of Physics, Tohoku University∗9 Department of Physics, Tokyo Institute of Technology∗10 Department of Physics, Konan University∗11 Department of Physics, Kyungpook National University∗12 Department of Physics, Kyushu University∗13 Department of Physics, Technical University Munich∗14 Dept. of Physics and Astronomy, Seoul National University∗2- 54 -

experiments4,5) this effect is not well studied and further experimental data are needed.
A new experimental technique developed at NSCL,MSU6,7) will be applied to measure the (p,n) reaction
in inverse kinematics which enables us to achieve a highluminosity using a thick target without losing the information on the recoil neutron momentum necessary
for the missing mass reconstruction. The setup using BigRIPS, WINDS (Wide-angle Inverse-kinematics
Neutron Detectors for SHARAQ) and the SAMURAI
spectrometer together with a 10-mm thick liquid hydrogen target will allow us to extract the GT and SD
transition strengths from the low-lying region up to 40
MeV excitation energies. The use of the SAMURAI is
crucial for covering all decay channels simultaneously
and for obtaining conclusive data on the GT strengthsof the nuclei of interest.
By using WINDS placed at a distance of 1 m (1.25m) from the target position both on left and right (topand bottom) sides with respect to the beam line, we
detect recoil neutrons from the (p,n) reaction. Fromthe measured neutron TOF and recoil angle, the excitation energy and center-of-mass scattering angle canbe deduced. The reaction products will be momentumanalyzed by the SAMURAI spectrometer. The particle identification for the reaction residues will be madeusing the TOF and energy loss information measured
by hodoscopes (HODF, HODP). The energy loss information will be complementary used. The NEBULA
detector will be used for tagging the neutron decay of
the reaction products.
Our proposal has been presented at the 15th Program Advisory Committee for Nuclear Physics experiments at RI Beam Factory (NP-PAC). The NP-PAC
approved 5 days of beam time.
References
1) T. D. Taddeucci et al.: Nucl. Phys. A 469, 125 (1987).
2) C. Gaarde: Nucl. Phys. A 396, 127 (1983).
3) H. Sagawa et al.: Phys. Lett. B 303 215 (1993).
4) M. Kobayashi et al.: JPS Conf. Proc. 1, 013034 (2014).
5) H. Sakai et al.: In preparation.
6) M. Sasano et al.: Phys. Rev. Lett. 107, 202501 (2011).
7) M. Sasano et al.: Phys. Rev. C 86, 034324 (2012).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Spin-dipole response of 4 He by using (8 He, 8 Li(1+ ))The spin dipole (SD) (∆ S = ∆ L =1) of spin-isospin
responses is connected with the tensor correlation in
nuclei. Especially, on a double-closed nucleus, the SD
excitation contribution is large because of the nucleon
conﬁguration. The SD excitation function was measured on 4 He which is the lightest double-closed nucleus. This is important for the study of supernova
nucleosynthesis with the neutrino-nucleus reaction1) .
We coducted the exothermic charge-exchange (CE)reaction of 4 He(8 He, 8 Li(1+ ))4 H. CE reactions are
powerful tools to study the spin-isospin responses.
The spin-ﬂip transition of 8 He(0+ ) → 8 Li(1+ ) canbe identiﬁed by measuring the de-excited γ-rays(Eγ =0.98 MeV) from the ﬁrst 1+ state of 8 Li. The
beam energy region of 100–300 MeV/nucleon is suitable for the study of the spin-isospin responses2) .
The experiment was performed at the RIKEN
RIBF facility by using BigRIPS3) , the high-Resolution
beamline4) , and the SHARAQ spectrometer5) . The
8
He beam, which was produced via a projectilefragmentation reaction with an 18 O beam and 9 Be
target, was transported to the secondary target position at an intensity of 2 MHz. We used the liquid4
He target6) with a thickness of 120 mg/cm2 . In order to determine the excitation energy using missing
mass method, the momenta of 8 He and 8 Li at an energy of 190 MeV/nucleon were measured at the beamline and SHARAQ within the low-pressure multi-wiredrift chamber (LP-MWDC) 7) and cathode readout
drift chamber8) . The γ-ray detector array DALI29)
was placed around the target position to measure the0.98 MeV γ-ray.
Figure 1 shows the missing mass spectrum of the(8 He,8 Li) reaction (black line). The contribution ofboth the 4 He target and hydrogen is included in this∗1

Center for Nuclear Study, The University of Tokyo
RIKEN Nishina Center∗3 Institut de Physique Nucléaire, Orsay∗4 Department of Physics, Kyoto University∗5 Research Center Nuclear Physics, Osaka University∗6 Cyclotron and Radioisotope Center, Tohoku University∗7 Department of physics, Tokyo Institute of Technology∗8 Department of Applied Physics, University of Miyazaki∗9 National Institute of Radiological Sciences∗10 Department of physics, The University of Tokyo∗11 Department of Physics, Kyushu University∗12 National Superconducting Cyclotron Laboratory, Michigan
State University∗2- 55 -Counts/2
Counts/2 MeV
MeV

H. Miya,∗1 S. Shimoura,∗1 K. Kisamori,∗1,∗2 M. Assié,∗3 H. Baba,∗2 T. Baba,∗4 D. Beaumel,∗3 M. Dozono,∗1
T. Fujii,∗2 N. Fukuda,∗2 S. Go,∗1 F. Hammache,∗3 E. Ideguchi,∗5 N. Inabe,∗2 M. Itoh,∗6 D. Kameda,∗2
S. Kawase,∗1 T. Kawabata,∗4 M. Kobayashi,∗1 Y. Kondo,∗7 T. Kubo,∗2 Y. Kubota,∗1,∗2 C. S. Lee,∗1,∗2
Y. Maeda,∗8 H. Matsubara,∗9 S. Michimasa,∗1 K. Miki,∗5 T. Nishi,∗10 M. Kurata-Nishimura,∗2 S. Ota,∗1
H. Sakai,∗2 S. Sakaguchi,∗11 M. Sasano,∗2 H. Sato,∗2 Y. Shimizu,∗2 H. Suzuki,∗2 A. Stolz,∗12 M. Takaki,∗1
H. Takeda,∗2 S. Takeuchi,∗2 A. Tamii,∗5 H. Tokieda,∗1 M. Tsumura,∗4 T. Uesaka,∗2 K. Yako,∗1 Y. Yanagisawa∗2
and R. Yokoyama∗1

30
30
25
25
20
20
15
15
10
10
55
00
-30 -20-20 -10
-10
-30

00

10
10

20
20

30 40
40 50
50 60
60 70
70
30
Excitation energy
energy [MeV][MeV]
Excitation

Fig. 1. Excitation energy distribution of 4 H obtained using missing mass method. The red line shows the background estimated from the contamination of the excitation energy distribution.

spectrum. The region around 10 MeV and −17 MeV
shows the 4 He →4 H and 1 H → n reactions, respectively. The 1 H → n reaction originates at the plastic
scintilator installed at the upstream of the target. The
amount of contamination (red line) was estimated byusing the energy loss of the LP-MWDC placed between
the scintilator and the target. Thus, the 4 He(8 He,
8Li)4 H reaction was obtained.
Further analysis to obtain the angular distribution
and double diﬀerential cross-sections is now in progress
to obtain the isovector SD strength of 4 He.
References
1) T. Suzuki et al. Phys. Rev. C 74, 034307 (2006).
2) W. G. Love and M. A. Franey: Phys. Rev. C 24, 1073
(1981).
3) T. Kubo et al.: Nucl. Instr. Meth. B 204, 97-113 (2003).
4) T. Kawabata et al.: Nucl. Instr. Meth. B 266, 4201-4204(2008).
5) S. Michimasa et al.: Nucl. Instr. Meth. B 317, 305-310(2013).
6) H. Ryuto et al: Nucl. Instr. Meth. A 555, 1-5 (2005).
7) H. Miya et al.: Nucl. Instr. Meth. B 317, 701-704 (2013).
8) K. Kisamori et al.: CNS Ann. Rep. 2011 (2013).
9) T. Takeuchi et al.: Nucl. Instr. Meth. A 763, 1-8 (2014).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Spectroscopy of Single-Particle States in Oxygen Isotopes via
AO(p, 2p) Reaction with Polarized Protons
S. Kawase,∗1 T. L. Tang,∗1 T. Uesaka,∗2 D. Beaumel∗2,∗3 M. Dozono,∗2 T. Fujii,∗1,∗2 T. Fukunaga,∗2,∗4
N. Fukuda,∗2 A. Galindo-Uribarri,∗5 S. H. Hwang,∗6 N. Inabe,∗2 D. Kameda,∗2 T. Kawahara,∗2,∗7 W. Kim,∗6
K. Kisamori,∗1,∗2 M. Kobayashi,∗1 T. Kubo,∗2 Y. Kubota,∗1,∗2 K. Kusaka,∗2 C. S. Lee,∗1,∗2 Y. Maeda,∗8
H. Matsubara,∗2 S. Michimasa,∗1 H. Miya,∗1∗2 T. Noro,∗2,∗4 A. Obertelli,∗9 S. Ota,∗1 E. Padilla-Rodal,∗10
S. Sakaguchi,∗2,∗4 H. Sakai,∗2 M. Sasano,∗2 S. Shimoura,∗1 S. S. Stepanyan,∗6 H. Suzuki,∗2 M. Takaki,∗1,∗2
H. Takeda,∗2 H. Tokieda,∗1 T. Wakasa,∗2,∗4 T. Wakui,∗2,∗11 K. Yako,∗1 Y. Yanagisawa,∗2 J. Yasuda,∗2,∗4
R. Yokoyama,∗1,∗2 K. Yoshida,∗2 and J. Zenihiro∗2 for the SHARAQ04 collaboration
count/5mm Excitation Energy of 21N (MeV)

90
80
70
60
50
40
30
20
10
0
-200

O(p,2p)22
7

count/MeV
!"

22

80
70
60
50
40
30
20
10
0
-10

6
5
4

O(p,2p)#$

30


-130
< xS1
< -60
 
 (mm)

25

20

15

3

10

2
1

5

0

0

-60
< xS1
< 10

 (mm)

25

20

15
10
5
-150

-100

-50

0

50

100

150

0
-20


200

x S1 (mm)Fig. 1. Correlation between the excitation energy of 21 N
and xS1 .

We performed 14,22−24 O(p, 2p) reaction measurements (SHARAQ04 experiment) with a polarized proton target at RIBF to measure single-particle spectra and to determine spin-orbit splitting of 1p proton single-particle orbits in 14,22−24 O as a function of
their neutron number. For the experimental setup, see
ref.1) . In this report, current status of the analysis for
22
O(p,2p) is described.
The (p, 2p) reaction was identiﬁed via the particle identiﬁcations of incident nuclei and two scatteredprotons. Particles were identiﬁed via the Time-ofFlight(TOF)-∆E method on an event-by-event basis.
Then the proton separation energy of the incident nuclei and the excitation energy of the residual nuclei
were calculated from scattering angles and TOF ofscattered protons.
Position of the residual nuclei and TOF from thetarget are also measured at a focal plane S1 at the∗1

Center for Nuclear Study (CNS), University of Tokyo
RIKEN Nishina Center∗3 Institut de Physique Nucléaire d’Orsay∗4 Department of Physics, Kyushu University∗5 Oak Ridge National Laboratory∗6 Department of Physics, Kyungpook National University∗7 Department of Physics, Toho University∗8 Department of Applied Physics, University of Miyazaki∗9 CEA Saclay∗10 Instituto de Ciencias Nucleares, Universidad Nacional
Autónoma de México∗11 CYRIC, Tohoku University∗2- 56 -

-10
 

0

10

20


30
 40
 50
 60
 70
 80


Excitation
of 21
N
(MeV)
 Energy


Fig. 2. Excitation energy spectrum for 22 O(p, 2p) for eachxS1 region. The red lines show the background estimated from the 2p coincidence events occurred in the
carbon target.

downstream of the reaction point for the identiﬁcation of the residual particle in order to improve theS/N ratio and to separate the excited states of 21 N.
Figure 1 shows the correlation between the excitationenergy and the position of the residual nuclei at theS1 focal plane (xS1 ) after applying a TOF gate. At
S1, particles with larger Bρ come to the smaller xS1
region. There are two clear loci in the xS1 region of(−130, −60) and (−60, 10). The former corresponding
to 21 N and the latter should be 19 N or 20 N generated
through the neutron emission of 21 N. It will be clariﬁedby Bρ analysis.
Figure 2 shows the excitation energy spectra of 21 N
for diﬀerent xS1 regions. The red lines show the background originated from the carbon contamination of
the polarized target and obtained from the measurement with a carbon target. At least two discrete states
are observed in these plots.
The cross sections, spectroscopic factors, and thespin-polarization observables such as the vector analyzing power are expected to be obtained through subsequent analyses in the near future.
References
1) S. Kawase et al.: RIKEN Accel. Prog. Rep., 46, 30(2013)

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Status on residual analysis of SHARAQ04 experiment
T. L. Tang,*1 S. Kawase,*1 T. Uesaka,*2 D. Beaumel,*2,*3 M. Dozono,*2 T. Fujii,*1,*2 N. Fukuda,*2 T. Fukunaga,*2,*4
A. Galindo-Uribarri,*5 S. H. Hwang,*6 N. Inabe,*2 D Kameda,*2 T. Kawahara,*2,*7 W. Y. Kim,*6 K. Kisamori,*1,*2
M. Kobayashi,*1 T. Kubo,*2 Y. Kubota,*1,*2 K. Kusaka,*2 C. S. Lee,*1 Y. Maeda,*8 H. Matsubara,*2 S. Michimasa,*1
H. Miya,*1,*2 T. Noro,*2,*4 A. Obertelli,*9 S. Ota,*1 E. Padilla-Rodal,*10 S. Sakaguchi,*2,*4 H. Sakai,*2 M. Sasano,*2
S. Shimoura,*1 S. S. Stepanyan,*6 H. Suzuki,*2 M. Takaki,*1,*2 H. Takeda,*2 H. Tokieda,*1 T. Wakasa,*2,*4 T. Wakui,*2,*11
K. Yako,*1 Y. Yanagisawa,*2 J. Yasuda,*2,*4 R. Yokoyama,*1,*2, K. Yoshida,*2 and J. Zenihiro,*2 for SHARAQ04 collaboration
Proton knockout reaction on radioactive fluorine andoxygen isotopes was performed in SHARAQ04 experiment
at RIBF, RIKEN Nishina Center. The analyses on 14O and22
O have been reported by S. Kawase et al.1, 2). The
identification of residual nuclei at downstream (S1 focal
plane of the SHARAQ spectrometer3)) serves an importantrole in identifying the reaction channel and separating thestrengths in the excitation energy spectrum. The objectiveof the present analysis is particle identification via Z vs A/Q
plot. We will explain the conversion from the energy loss
(𝛥𝛥𝛥𝛥) vs time-of-flight (TOF) plot to the Z vs A/Q plot.

The conversion from 𝛥𝛥𝛥𝛥-TOF to Z-A/Q is based on thefollowing equations,
𝑍𝑍 = 𝛽𝛽√𝐿𝐿,
𝑔𝑔 + ℎ 𝐿𝐿

𝐴𝐴
𝑐𝑐 1
𝑥𝑥
= ( ) (𝐵𝐵𝜌𝜌 ) (1 +),𝐷𝐷1(𝑥𝑥|𝛿𝛿)𝑄𝑄
𝑢𝑢 𝛾𝛾𝛾𝛾(1)(2)

where 𝛽𝛽 and 𝛾𝛾 are the Lorentz factors of residual nuclei;
𝐿𝐿 is the light output of Nyoki; 𝑔𝑔 and ℎ are the parametersfrom the Birks formula4), which correct the non-linearity oflight-output and energy loss; 𝑐𝑐 is the speed of light invacuum; 𝑢𝑢 is the atomic mass unit; (𝐵𝐵𝜌𝜌 )𝐷𝐷𝐷 is the magnetic
rigidity of the D1 magnet (6.5269 Tm); 𝑥𝑥 is the x-position
on MWDC-S1; and (𝑥𝑥|𝛿𝛿) is the dispersion at the S1 focal
plane.
Figure 2 shows the Z vs A/Q plots for the beam without
reaction. The left plot is from downstream and the right plot
is from upstream. The accuracy and resolution of both Z
and A/Q in the downstream plot are bad compared withthose in the upstream plot. The resolution of Z is 0.3 in thedownstream plot, while it is 0.1 for the upstream plot. The
resolution of A/Q is 0.1 for the downstream plot, and it is0.01 for the upstream plot.

Fig. 1. Experimental setup before S1 focal plane of
SHARAQ spectrometer.
Figure 1 shows the experimental setup for downstream.
The TOF was measured by an array of 14 identical plastic
scintillators (5 mm X 50 mm X 85 mm), named Nyoki, witha plastic scintillator (PLS0D) located in the entrance of theSDQ magnet as start timing. Each scintillator of Nyoki waslabeled from 0 to 13. The even ID scintillators were 10 mm
downstream from odd ID. There was 5 mm overlap between
adjacent IDs. The energy loss of each Nyoki’s scintillator
was calibrated with the energy loss in PLS0D. The positionsof the residual nuclei were measured by an MWDC at theexit of the D1 magnet. The flight-length was then calculated
by using the position at S1. The velocities of the residual
nuclei were calculated from the flight length and the TOF.

Fig. 2. Z vs A/Q plots under beam trigger; (left)
downstream; (right) upstream.
The analysis is still in progress. We are focusing on
improving the accuracy and resolution by 1) better
estimation of the parameters such as 𝑔𝑔, ℎ, and (𝑥𝑥𝑥𝑥𝑥𝑥; 2)
better calculation on flight-length; and 3) better tracking of
SMWDC-S1.

Center of Nuclear Study (CNS), University of Tokyo
RIKEN Nishina Center
Institut de Physique Nucléaire d’Orsay＊4
Department of Physics, Kyushu University＊5
Oak Ridge National Laboratory＊6
Department of Physics, Kyungpook National University＊7
Department of Physics, Toho University＊8
Department of Applied Physics, University of Miyazaki＊9
CEA Saclay＊10
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma deMéxico＊11
CYRIC, Tohoku University
＊1
＊2
＊3

References

1) S. Kawase et al.: RIKEN Accel. Prog. Rep. 46 (2013) 30.
2) S. Kawase et al.: in this report.
3) T. Uesaka et al.: Nucl. Inst. Meth. Phys. B 266 (2008) 4218.
4) W. R. Leo: Techniques for Nuclear and Particle Physics
Experiments (Springer-Verlag, Berlin, 1994), P 168.

- 57 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Parity-transfer reaction for study of spin-dipole 0− mode
M. Dozono,∗1 K. Fujita,∗2 N. Fukuda,∗3 M. Ichimura,∗3 N. Inabe,∗3 S. Kawase,∗1 K. Kisamori,∗1 Y. Kiyokawa,∗1
K. Kobayashi,∗4 M. Kobayashi,∗1 T. Kubo,∗3 Y. Kubota,∗1 C. S. Lee,∗1 M. Matsushita,∗1 S. Michimasa,∗1
H. Miya,∗1 A. Ohkura,∗2 S. Ota,∗1 H. Sagawa,∗1,∗5 S. Sakaguchi,∗2 H. Sakai,∗3 M. Sasano,∗3 S. Shimoura,∗1
Y. Shindo,∗2 L. Stuhl,∗3 H. Suzuki,∗3 H. Tabata,∗2 M. Takaki,∗1 H. Takeda,∗3 H. Tokieda,∗1 T. Uesaka,∗3
T. Wakasa,∗2 K. Yako,∗1 M. Yamagami,∗5 Y. Yanagisawa,∗3 J. Yasuda,∗2 R. Yokoyama,∗1 K. Yoshida,∗3 and
J. Zenihiro∗3
The spin-dipole (SD) 0− excitation has recently attracted theoretical attention owing to its strong relevance in the tensor correlations in nuclei. For example,
self-consistent HF+RPA calculations in Ref.1) predictthat the tensor correlations produce a strong hardening (shifting toward higher excitation energy) eﬀect on
the 0− resonance. It is also predicted that the eﬀect issensitive to the magnitude of the tensor strength. Thus
experimental data of the SD 0− distribution enable us
to examine the tensor correlation eﬀects quantitatively.
Despite this importance, experimental information on
0− states is limited because of the lack of the experimental tools suitable for 0− studies.
We propose a new probe, the parity-transfer(16 O, 16 F(0− , g.s.)) reaction, for 0− studies2) . The
parity-transfer reaction selectively excites unnaturalparity states for a 0+ target nucleus, which is an advantage over the other reactions used thus far. In order toestablish the parity-transfer reaction as a new tool for0− studies, we measured the 12 C(16 O, 16 F(0− , g.s.))12 B
reaction. We demonstrate the eﬀectiveness of this reaction by identifying the known 0− state at Ex =9.3 MeV in 12 B.
The experiment was performed at the RIKEN RI
Beam Factory (RIBF) by using the SHARAQ spectrometer and the high-resolution beam line. Figure 1
shows a schematic layout of the experimental setup. A
primary 16 O beam at 250 MeV/nucleon and 107 pps

from the superconducting RING cyclotron (SRC) wastransported to the S0 target position. The beamline to the spectrometer was set up for dispersionmatched transport. We used a segmented plastic scintillation detector as an active 12 C target. This detector consisted of 16 plastic scintillators with a size of
30 mm × 5 mm × 1 mm, and it was used to determine
the x-position of the beam on the target. The outgoing
15
O + p particles produced by the decay of 16 F were
measured in coincidence. The particles were momentum analyzed by using the SHARAQ spectrometer.
The 15 O particles were detected with two low-pressure
multi-wire drift chambers (LP-MWDCs) at the S2 focal plane, while the protons were detected with two
MWDCs at the S1 focal plane.
We reconstructed the relative energy Erel between
the 15 O and the proton. A preliminary result is shownin Fig. 2. The obtained Erel resolution was 150 keV in
FWHM at Erel = 535 keV, and the 0− ground stateof 16 F was clearly separated from other excited states.
In order to identify the 12 B(0− , 9.3 MeV) state, data
analysis for obtaining the 12 C(16 O, 16 F(0− , g.s.)) spectrum and its angular distributions is in progress.

Fig. 2. Preliminary result of the relative energy between
the 15 O nucleus and the proton from the decay of 16 F.

∗1
∗2
∗3
∗4
∗5

Fig. 1. Schematic layout of the experimental setup.

References

Center for Nuclear Study, University of Tokyo
Department of Physics, Kyushu University
RIKEN Nishina Center
Rikkyo University
Center for Mathematics and Physics, University of Aizu

1) H. Sagawa and G. Colò: Prog. Part. Nucl. Phys. 76, 76(2014).
2) M. Dozono et al.: RIKEN Accel. Prog. Rep. 45, 10(2012).

- 58 -

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Direct mass measurements of neutron-rich Ca isotopes beyond
N = 34
M. Kobayashi,∗1 S. Michimasa,∗1 Y. Kiyokawa,∗1 H. Baba,∗2 G.P.A. Berg,∗3 M. Dozono,∗1 N. Fukuda,∗2
T. Furuno,∗4 E. Ideguchi,∗5 N. Inabe,∗2 T. Kawabata,∗4 S. Kawase,∗1 K. Kisamori,∗1,∗2 K. Kobayashi,∗6
T. Kubo,∗2 Y. Kubota,∗1,∗2 C.S. Lee,∗1,∗2 M. Matsushita,∗1 H. Miya,∗1 A. Mizukami,∗7 H. Nagakura,∗6
D. Nishimura,∗7 H. Oikawa,∗7 S. Ota,∗1 H. Sakai,∗2 S. Shimoura,∗1 A. Stolz,∗8 H. Suzuki,∗2 M. Takaki,∗1
H. Takeda,∗2 S. Takeuchi,∗2 H. Tokieda,∗1 T. Uesaka,∗2 K. Yako,∗1 Y. Yamaguchi,∗6 Y. Yanagisawa,∗2
R. Yokoyama,∗1 and K. Yoshida∗2
The shell evolution in nuclei far from stability is oneof the main subjects of nuclear physics. Nuclear mass
is one of the most fundamental quantity providing information on the shell structure. The neutron numbersof 32 and 34 have been suggested to be candidates of
new magic numbers in the Ca isotopes1) . Recently
the masses of 53 Ca and 54 Ca were measured, and theshell closure at N = 32 was established2) . The present
work aims at studying the nuclear shell evolution at
N = 32, 34 by direct mass measurements of neutronrich nuclei in the vicinity of 54 Ca.
The experiment was performed at the RIKEN RI
Beam Factory (RIBF). The masses were measured directly by the TOF-Bρ method. Neutron-rich isotopes
were produced by fragmentation of a 70 Zn primarybeam at 345 MeV/nucleon in a 9 Be target. The fragments were separated by BigRIPS, and transported in
the High Resolution Beam Line to the SHARAQ spectrometer. The beam line and SHARAQ were operated
in the dispersion matching mode allowing a momentum resolution of 1/14700.

Fig. 1. Schematic view of the beamline and the detectors
used in the experiment.
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Center for Nuclear Study, University of Tokyo
RIKEN Nishina Center
Department of Physics, University of Notre Dame
Department of Physics, Kyoto University
RCNP, Osaka University
Department of Physics, Rikkyo University
Department of Physics, Tokyo University of Science
NSCL, Michigan State University

A schematic view of the beamline with the detectors used in the experiment is shown in Fig. 1. The
TOF was measured with newly developed diamonddetectors3) installed at BigRIPS-F3 and the ﬁnal focal plane of SHARAQ (S2). The ﬂight path length
between F3 and S2 is 105 m along the central ray.
We installed two low pressure multi-wire drift chambers (LP-MWDCs)4) at both F3 and S2 to correct theﬂight pass lengths using the tracking information on
an event-by-event basis. The Bρ value was measured
by a parallel plate avalanche counter (PPAC) locatedat the target position of SHARAQ (S0). At S2, we
mounted two silicon strip detectors for identiﬁcationof the atomic numbers of the fragments. To identify
the isomers, which leads to a systematic shift towards
higher masses, we placed a plastic stopper downstreamof S2 and a γ-detector array consisting of 2 Ge cloverand 16 NaI(Tl) detectors. Details of this system canbe found in Ref.5) .
Figure 2 shows the preliminary particle identiﬁcation of the secondary beams. The total yield of 55 Ca
was on the order of several thousands. Many species ofreference nuclei over a broad range of A and Z were observed, which were used in the mass calibration. Further analysis is in progress.

Fig. 2. Particle identiﬁcation of the secondary beams.

References
1) T. Otsuka et al.: Phys. Rev. Lett. 87 082502 (2001).
2) F. Wienholtz et al.: Nature 498 349 (2013).
3) S. Michimasa et al.: Nucl. Instr. Meth. B 317 305 (2013).
4) H. Miya et al.: Nucl. Instr. Meth. B 317 317 (2013).
5) Y. Kiyokawa et al.: in this report.

- 59 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Gamma-ray detector array for isomer tagging at SHARAQ
Y. Kiyokawa,∗1 S. Michimasa,∗1 M. Kobayashi,∗1 R. Yokoyama,∗1 D. Nishimura,∗2 S. Ota,∗1 A. Mizukami,∗2
H. Oikawa,∗2 K. Kobayashi,∗3 H. Baba,∗4 G.P.A. Berg,∗5 M. Dozono,∗1 N. Fukuda,∗4 T. Furuno,∗6
E. Ideguchi,∗7 N. Inabe,∗4 T. Kawabata,∗6 S. Kawase,∗1 K. Kisamori,∗1,∗4 T. Kubo,∗4 Y. Kubota,∗1,∗4
C.S. Lee,∗1 M. Matsushita,∗1 H. Miya,∗1 H. Nagakura,∗3 H. Sakai,∗4 S. Shimoura,∗1 A. Stolz,∗8 H. Suzuki,∗4
M. Takaki,∗1 H. Takeda,∗4 S. Takeuchi,∗4 H. Tokieda,∗1 T. Uesaka,∗4 K. Yako,∗1 Y. Yamaguchi,∗3
Y. Yanagisawa,∗4 and K. Yoshida∗4
Mass measurement of neutron-rich short-lived nuclei
was performed by employing the TOF-Bρ techniqueat the RIKEN RI Beam Factory(RIBF). A beam of70
Zn at 345MeV/nucleon bombarded a 9 Be target to
produce neutron-rich nuclei with atomic numbers (Z)ranging from 10 (Ne) to 23 (V) and A/Q from 2.5
to 2.9. Nuclei of interest were separated and particle identiﬁed on an event-by-event basis by using the
BigRIPS separator coupled with the SHARAQ spectrometer. Details of this experiment can be found in
Ref.1) .
Herein, we report on an isomer tagging gammaray detector array to assist in particle identiﬁcation.Furthermore the array was used to search for new
isomeric states. Figure 1 shows a schematic view of the
γ-ray detector array, installed in the air downstreamof the ﬁnal focal plane (S2) of the SHARAQ spectrometer. The array consisted of 2 clover-type HPGe detectors, each surrounded with 8 NaI(Tl) scintillators.
A 20-mm-thick plastic scintillator was placed as an active beam stopper for Sc isotopes at the center of thedetector array. An 12-mm-thick aluminum degrader
was installed upstream to adjust the stopping range ofthe nuclei of interest. A veto scintillator was installed
downstream of the γ-ray detector array to reject theevents where the nuclei penetrated the stopper. The
dynamic range of HPGe and NaI(Tl) detectors covers γ-rays up to 3 MeV. The energy resolution of the
HPGe [NaI(Tl)] detectors was about 3.8 keV [60 keV]
at 1333 keV [662 keV] in FWHM and full-energy peakeﬃciencies were 0.6% [9.7%] for 1.2-MeV γ rays. The
decay time window for gamma-ray spectra was set to
100 ns – 15 µs after the particles arrived at S2. The
data acquisition (DAQ) system for the γ-ray detector
array was separate from the one for the mass measurement and ran with single triggers from HPGe or
NaI(Tl) detectors. For making an event correlation
between the two DAQs used for isomer tagging andfor particle identiﬁcation, a common time stamp wasrecorded in both DAQ systems.
Figure 2 shows the delayed γ-ray spectra measuredby HPGe in (a) 50 K and (b) 43 S used for the particle
identiﬁcation. The energies of the observed gamma
rays were consistent with those of previous works,
Refs.2),3) .
Further analysis for the identiﬁcation of new isomeric states and isomeric ratios is in progress.

Fig. 1. Schematic view of the isomer tagging system downstream of the final focal plane of SHARAQ(S2).

Fig. 2. Delayed γ-ray spectra measured by HPGe in (a)50
K and (b) 43 S used for the particle identification.

∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Center for Nuclear Study, University of Tokyo
Tokyo University of Science
Rikkyo University
RIKEN Nishina Center
University of Notre Dame
Department of Physics, Kyoto University
RCNP, Osaka University
NSCL, Michigan State University

References
1) M. Kobayashi et al.: in this report.
2) J.M. Daugas et al.: Phys. Rev. C. 81 (2010) 034304.
3) L. Gaudefroy et al.: Phys. Rev. Lett. 102 (2009) 092501.

- 60 -

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Quadrupole collectivity in island-of-inversion nuclei
28,30
Ne and 34,36 Mg†
S. Michimasa,∗1 Y. Yanagisawa,∗2 K. Inafuku,∗3 N. Aoi,∗4 Z. Elekes,∗5 Zs. Fülöp,∗5 Y. Ichikawa,∗2 N. Iwasa,∗3
K. Kurita,∗6 M. Kurokawa,∗2 T. Machida,∗6 T. Motobayashi,∗2 T. Nakamura,∗7 T. Nakabayashi,∗7 M. Notani,∗8
H. J. Ong,∗4 T. K. Onishi,∗9 H. Otsu,∗2 H. Sakurai,∗2,∗9 M. Shinohara,∗7 T. Sumikama,∗3 S. Takeuchi,∗2
K. Tanaka,∗2 Y. Togano,∗7 K. Yamada,∗2 M. Yamaguchi,∗2 and K. Yoneda∗2
We report here on the in-beam γ-ray spectroscopy
in very neutron-rich even-even nuclei of 28,30 Ne and34,36
Mg by proton inelastic scattering using a liquidhydrogen target in inverse kinematics. The 30 Ne nucleus has a conventional magic number of 20, and 36 Mg
is located in the middle of the shell closures of N = 20
and 28. The 30 Ne and 36 Mg are closer to the neutron
drip line than the nuclei belonging to the so-called “island of inversion (IOI)”. We have studied the evolution of quadrupole deformation on the side with moreneutrons and less protons than IOI. The report is acondensed version of our published paper1) .
The experiment was performed using the RIPS
beamline at the RI Beam Factory. A radioactive secondary beam, containing neutron-rich nuclei 32,34,36 Mg
and 28,30 Ne, was produced by fragmentation reactions
from 63-MeV/nucleon 48 Ca. Details of the experimental setup around the secondary target and beam conditions are provided in Ref.1) .
The angle-integrated cross sections for population of+
the 2+
1 states were obtained from the yields of the 21 →+01 transitions with γ-detection multiplicity equal toone. The spectra are shown in Figs. 3–6, 8 in Ref.1) .
The deduced cross sections and deformation lengths
are summarized in Table 1.
The present results extended the measurements ofquadrupole collectivity along Ne and Mg isotopic

chains by providing deformation lengths with improved
accuracies for 28,30 Ne, 34 Mg and a new measurementfor 36 Mg. The systematic trends of the deformation
lengths are displayed in Fig. 1(a) and (b). The ﬁlled
and open circles indicate the deformation lengths deduced in the present work and those that have been estimated from the previous results using the WP09 potential2) , respectively. The thin black and thick orange
error bars represent statistical and systematic errors,
respectively. The squares indicate previous results of
Coulomb excitation experiments.
Figures 1(a) and (b) also display several theoretical results that can be compared to the experimental
results. The solid-blue and dashed-red lines are predictions by AMPGCM3) and the shell model with the
SDPF-M eﬀective interaction4) , respectively. The shellmodel calculations in a 0h̄ω model space are shown by
the green dotted5) and orange dotted6) lines. For Mg
isotopes, the AMPGCM and SDPF-M calculations,which implement conﬁguration mixing around N = 20,
reproduce the systematic trend of experimental deformation lengths in a satisfactory manner. In addition,
they agree with the trend for the Ne isotopic chain, although they both systematically overestimate the experimental values.

Table 1. Angle-integrated cross sections for the 2+
1 statesand deduced deformation lengths in 28,30 Ne and32,34,36
Mg.
Nucleus
28
Ne
30
Ne
32
Mg
34
Mg
36
Mg
†
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

σ(2+
1 ) (mb)
23(2)
37(4)
40+9
−8
63(5)
47(8)

δ(p,p′ ) (fm)1.33 ± 0.06 (stat) ±0.05 (syst)
1.59+0.08−0.09 (stat) ±0.07 (syst)
1.85 ± 0.20 (stat) ±0.08 (syst)
2.30+0.09−0.10 (stat) ±0.16 (syst)
1.90+0.16−0.17 (stat) ±0.16 (syst)

Fig. 1. Systematics of deformation lengths around the IOIregion. Panels (a) and (b) show deformation lengths of
Ne and Mg isotopes, respectively. Details are describedin the text.

Condensed from the article in Phys. Rev. C 89, 054307(2014).
Center for Nuclear Study, University of Tokyo
RIKEN Nishina Center
Department of Physics, Tohoku University
RCNP, Osaka University
ATOMKI
Department of Physics, Rikkyo University
Department of Physics, Tokyo Institute of Technology
Argonne National Laboratory
Department of Physics, University of Tokyo- 61 -

References
1) S. Michimasa et al., Phys. Rev. C 89 (2014) 054307.
2) S.P. Weppner et al., Phys. Rev. C 80 (2009) 034608.
3) R.R. Rodrı́guez-Guzmán et al., Eur. Phys. J. A 17
(2003) 37; Nucl. Phys. A 709 (2002) 201; Phys. Lett.
B 474 (2000) 15.
4) Y. Utsuno et al., Rhys. Rev. C 60 (1999) 054315.
5) E. Caurier et al., Rhys. Rev. C 58 (1998) 2033.
6) F. Nowacki and A. Poves, Phys. Rev. C 79 (2009)014310.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Study of nuclear structure in proton-rich carbon isotopes
T. Miyazaki,∗1,∗2 H. Otsu,∗2 E. Yu. Nikolskii,∗2,∗5 Y. Shiga,∗2,∗3 M. Kurata-Nishimura,∗2 S. Takeuchi,∗2
Y. Satou,∗4 M. Kurokawa,∗2 H. Baba,∗2 G. Lorusso,∗2 T. Isobe,∗2 M. Niikura,∗1 E. A. Kuzmin,∗2,∗5
A. A. Korsheninnikov,∗2,∗5 A. A. Ogloblin,∗2,∗5 S. A. Krupko,∗6 M. S. Golovkov,∗6 A. A. Bezbakh,∗6
R. S. Slepnev,∗6 A. S. Fomichev,∗6 S. I. Sidorchuk,∗6 A. V. Gorshkov,∗6 A. G. Knyazev,∗6 P. Papka,∗7
H. J. Ong,∗8 S. Kim,∗4 J. W. Hwang,∗4 S. Choi,∗4 H. Chae,∗4 E. Kim,∗4 Y. H. Kim,∗4 D. Lubos,∗2,∗9
D. Beaumel,∗2,∗10 P. A. Söderström,∗2 S. Sakaguchi,∗11 S. Kubono,∗2 A. K. Perrevoort,∗2 E. Milman,∗2
S. Chebotaryov,∗2 W. Powell,∗2 T. Motobayashi,∗2 K. Yoneda,∗2 and H. Sakurai∗1,∗2∗1

Department of Physics, The University of Tokyo
RIKEN Nishina Center∗3 Department of Physics, Rikkyo University∗4 Department of Physics, Seoul National University∗5 National Research Centre “Kurchatov Institute”∗6 Flerov Laboratory of Nuclear Reactions, Joint Institute for
Nuclear Research∗7 Department of Physics, Stellenbosch University∗8 Research Center for Nuclear Physics, Osaka University∗9 Technische Universität München∗10 Institut de Physique Nucléaire d’Orsay, IN2P3/CNRS∗11 Department of Physics, Kyushu University∗2- 62 -

ing the 10 C(p, t) and 10 C(p, d) reactions, respectively.
Their excitation energies were consistent with the previous results. In future studies, observation of the excited states in 8 C with higher statistics, better energy
resolution, and higher S/N ratio is expected.

Counts/ 250
keV


400

400


g.s.


300

300


200

200


100

100

00-10


-10


-5
-5

00

55


10

10


15
15

x[MeV] EFig. 1. The excitation energy spectrum of 8 C.

500

500



Counts/ 250
keV

The structures of the proton-rich carbon isotopes 8 C
and 9 C were studied by the neutron transfer 10 C(p, t)
and 10 C(p, d) reactions, respectively. The experiment
was aimed at measuring the unknown excited statesin 8 C, which had not been achieved in the previous
studies1–4) and identifying the decay property of theunbound ﬁrst excited state in 9 C.
The experiment was performed in 2013 at the
RIKEN RIPS facility5) . A 10 C secondary beam at
51 AMeV was impinged on the hydrogen gas target system (CRYPTA)6,7) . Recoilied tritons and deuterons
were identiﬁed by using the ∆E-E method, with thehelp of the Dubna telescope consisting of an annular
double-sided strip silicon detector and 16 CsI(Tl) scintillators. The reaction residues were identiﬁed by the∆E-E method using a four-plastic-scintillator array at
0 degree8) .
The excitation energy spectrum of 8 C after subtracting the background is shown in Fig. 1. The groundstate of 8 C was observed. The deduced mass excess of
the 8 C nucleus was 34.9(1.1) MeV, which is consistent
with the values reported in previous works1–4) . The
diﬀerential cross-section of the 10 C(p, t)8 Cg.s. reaction
will be analyzed in order to deduce the transferred angular momentum in the reaction.
The background-subtracted excitation energy spectrum of 9 C is shown in Fig. 2. The known groundand ﬁrst excited states in 9 C were observed. The deduced excitation energy of the ﬁrst excited state in 9 C
was 2.4(5) MeV, which is consistent with the value obtained in the previous experiment9) . By tagging theresidual nucleus separated by the detectors at 0 degree, the decay paths of the ﬁrst excited states in 9 C
will be determined.
In summary, the ground state of 8 C and the groundand ﬁrst excited states of 9 C were observed by us-

400

400


g.s.

2.2


300
300


200
200


100
100


-5
00-500Ex[MeV]
 

55

10
10



Fig. 2. The excitation energy spectrum of 9 C.

References
1) R. G. H. Robertson et al.: Phys. Rev. Lett. 32, 1207 (1974).
2) R. E. Tribble et al.: Phys. Rev. C 13, 50 (1976).
3) R. G. H. Robertson et al.: Phys. Rev. C 13, 1018 (1976).
4) R. J. Charity et al.: Phys. Rev. C 84, 014320 (2011).
5) T. Kubo et al.: Nucl. Instrum. Methods B 70, 309 (1992).
6) H. Ryuto et al.: Nucl. Instrum. Methods. A 555, 1 (2005).
7) M. Kurata-Nishimura et al.: RIKEN Accel. Prog. Rep. 46,
165 (2013).

8) T. Miyazaki et al.: RIKEN Accel. Prog. Rep. 47, 23 (2014).
9) W. Benenson and E. Kashy: Phys. Rev. C 10, 2633 (1974).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Triton contamination in the 10 C secondary beam produced by RIPS
T. Miyazaki,∗1 H. Otsu,∗2 M. Niikura,∗1∗2 for DA13-03-01 collaboration
We have performed missing mass spectroscopy on
C to measure its excited states populated by the twoneutron transfer reaction from 10 C, 10 C(p, t)8 C, in an
inverse kinematics.1,2) In this experiment, an unexpected triton contamination was found to occur in a
proton-rich 10 C secondary beam produced and separated by the RIKEN Projectile-fragment Separator(RIPS).3)
The 10 C secondary beam was produced by the
projectile-fragmentation of a 12 C beam with an energyof 70 MeV/nucleon impinging on a 94.2-mg/cm2 -thick9
Be production target. The secondary beam was ﬁrst
separated by its magnetic rigidity (Bρ) using the ﬁrst
dipole magnet (D1) and a slit at the dispersive focal
plane (F1) of the RIPS. A wedge-shaped aluminum degrader of 321-mg/cm2 thickness was placed at F1 forfurther selection of the beam through analysis of its Bρ
using the second dipole magnet (D2) and a slit at theachromatic focus (F2). The widths of the F1 and F2
slits were adjusted to ±24 mm and ±5 mm, and magnetic rigidities of D1 and D2 were set to 1.9858 Tm
and 1.8262 Tm, respectively. We expected to obtainnearly pure 10 C beam using this RIPS setting.
The secondary 10 C beam was injected into a cryogenic H2 gas target (CRYPTA)4) to induce the (p, t) reaction. The recoil tritons were detected with a Dubna
telescope consisting of an annular double-sided strip
silicon detector followed by cesium iodide scintillators. The telescope was installed downstream of the
CRYPTA target. The excitation energy of the protonunbound 8 C nucleus of was reconstructed by measuring the scattering angle and the total kinetic energy(TKE) of the recoil tritons.
Figure 1 shows the TKE spectra of tritons detectedwith the Dubna telescope. The solid line represents
the TKE spectrum measured with the H2 gas target (target run) and the shaded histogram represents
that without the target (empty run) normalized by thebeam intensity. The peak at 55 MeV (Gg.s. ), which isfound only in the target run, corresponds to the groundstate of 8 C produced by the two-neutron transfer reaction. The mass excess of the ground state of 8 C deduced from this peak is consistent with previous studies.5–8) Hence, the peak at 48 MeV (G0 ) should not
originate from the (p, t) reaction.
To identify the origin of the G0 peak, the positionof the detected triton on the Dubna telescope is plotted by gating on G0 and Gg.s. as shown in Fig. 2 (a)and (b), respectively. While tritons produced by thetransfer reaction were found to distribute through the

600
600

∗1
∗2

Department of Physics, the University of Tokyo.
RIKEN Nishina Center.

- 63 -Counts8

G0 Gg.s.

400
400

200
200

0020
20

40
40

60
60

80
80

TKE [MeV]

Fig. 1. Total kinetic energy of tritons measured with the
Dubna telescope in the target run (solid line) and emptyrun (shaded)
50 (a) gated on G0
-50

50

45

250

(b) gated on Gg.s.

40y [mm]

200
200

35
30

150
150

00

25

0

20

100
100

15
10

50
-50
-50

5

-50
-50
-50

00

50
50

0

-50
-50

x [mm]

00

50
50

0

Fig. 2. Hit position of tritons on the Dubna telescope gatedon the TKE spectra of G0 (a) and Gg.s. (b).

entire region of the Dubna telescope, tritons in G0 weredetected only at the inner rings of the telescope. In addition, the TKE of tritons having Bρ of D2 is 52 MeV,
which is close to the measured TKE of G0 . Therefore,
we concluded that a triton contaminant was present in
the proton-rich 10 C secondary beam.
In the present experiment, data acquisition was triggered by timing signals of the plastic scintillator placed
upstream of the target (PlF3 ) coincident with the
Dubna telescope. Since the threshold of PlF3 was set
to be much higher than the energy loss for the tritons,
the triton contaminants on the Dubna telescope wereobtained as an accidental-coincidence events and thecount rate of the tritons could not be estimated. The
contaminants were removed by gating on the prompt
timing of the Dubna telescope for further analysis.
In conclusion, we observed the unexpected triton
contaminant in the proton-rich 10 C secondary beam,even though a large A/Q diﬀerence exists between 10 C
and triton.
References
1) T. Miyazaki et al.: RIKEN Acc. Prog. Rep. 47, 23 (2014).
2) T. Miyazaki et al.: RIKEN Acc. Prog. Rep. 2014.
3) T. Kubo et al.: Nucl. Instrum. Methods B 70, 309 (1992).
4) H. Ryuto et al.: Nucl. Instrum. Methods. A 555, 1 (2005).
5) R.G.H. Robertson et al.: Phys. Rev. Lett. 32, 1207 (1974).
6) R.E. Tribble et al.: Phys. Rev. C 13, 50 (1976).
7) R.G.H. Robertson et al.: Phys. Rev. C 13, 1018 (1976).
8) R.J. Charity et al.: Phys. Rev. C 84, 014320 (2011).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

β-NMR measurement of 41 S
Y. Ichikawa,∗1 Y. Ohtomo,∗1,∗2 Y. Ishibashi,∗1,∗3 T. Suzuki,∗2 T. Sato,∗2 K. Imamura,∗1,∗4 T. Fujita,∗5
T. Furukawa,∗6 K. Asahi,∗2 T. Egami,∗7 C. Funayama,∗2 M. Hayasaka,∗8 C. Hirao,∗2 S. Kojima,∗2 T. Komine,∗2
M. Matsumoto,∗8 Y. Sakamoto,∗2 A. Takamine,∗9 D. Tominaga,∗7 H. Yamazaki,∗1 and H. Ueno∗1

∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

RIKEN Nishina Center
Department of Physics, Tokyo Institute of Technology
Department of Physics, University of Tsukuba
Department of Physics, Meiji University
Department of Physics, Osaka University
Department of Physics, Tokyo Metropolitan University
Department of Physics, Hosei University
Department of Physics, Tokyo Gakugei University
Department of Physics, Aoyama Gakuin University- 64 -

300
280

43Cl

260

Energy loss (MeV)

The erosion of N = 28 shell gap has been suggested
from several spectroscopic experimental data.1–4) In
particular, the 43 S nucleus is of considerable interest because shape coexistence is expected to occur,
which is key to understanding the evolution of shellgaps far from stability. The isomeric state of 43 S at
320 keV is suggested to have a shape close to sphericalwith a spin-parity of 7/2− ,5,6) but both the spin-parityand deformed parameter of the ground state have notbeen determined directly. To investigate the mechanics
leading to such an anomalous nuclear structure, we aim
to measure the ground-state nuclear moment of 41,43 S.
First, µ of 41 S was measured using the β-ray detectednuclear magnetic resonance (β-NMR) method,7) combined with a technique to produce spin-polarized RI
beams.8)
The experiment was carried out at the RIPS facility
at RIBF. The RI beam of 41 S was produced by thefragmentation of a primary beam of 48 Ca at an energyof E = 63 MeV/nucleon on a primary target of 9 Be
with a thickness of 0.52 mm. The typical intensity of
the 48 Ca beam at the target was 200 pnA. To realize
the spin polarization in 41 S, an emission angle of θF >1◦ and a momentum window of pF = p0 × (1.015 ±0.025) were selected, where p0 represents the central
momentum of the fragment 41 S. Under this condition,
the particle identification of the secondary beam was
performed on an event-by-event basis with information
regarding time of flight (TOF) and energy loss (∆E) as
shown in Fig. 1. The beam was pulsed with durationsof beam-on and beam-off periods of 2.9 s and 2.9 s,
equally.
The 41 S beam was then transported to the final focal plane and implanted into a stopper crystal of CaS
with which AP = −0.14% was observed previously,9)where A and P denote the asymmetry parameter forthe β-ray emission and the degree of polarization of
41
S, respectively. The CaS stopper was mounted between the poles of a dipole magnet that produces anexternal magnetic field of B0 = 0.5 T. β rays emitted
from the stopper were detected using plastic scintillator telescopes located above and below the stopper.
An oscillating radio-frequency field B1 was applied per-

240
220
200

41S

180
160
140
120
100

10

15

20

25

30

35

Time of flight (ns)Fig. 1. Particle identification of 41 S. The horizontal andvertical axes represent TOF between the plastic scintillators at F2 and F3, and ∆E taken at the silicondetector at F2, respectively.

pendicular to B0 using a pair of coils. The frequencyof B1 was swept over a certain region, and spin reversal occurred when the region included the Larmor
frequency. The spin reversal was detected through thechange of the up/down ratio R of the β-ray counts atthe two telescopes. Because the range within which
the g-factor of 41 S is predicted theoretically is quite
wide, a fast switching system for changing the tankcircuit frequency10) was used. In this experiment,
the g-factor search was conducted in the region where
0.2 < g < 0.8. The results of the NMR measurements
are under analysis.
References
1) R. W. Ibbotson et al.: Phys. Rev. C 59, 642 (1999).
2) F. Sarazin et al.: Phys. Rev. Lett. 84, 5062 (2000).
3) Zs. Dombrádi et al.: Nucl. Phys. A727, 195 (2003).
4) S. Grévy et al.: Eur. Phys. J. A 25, 111 (2005).
5) L. Gaudefroy et al.: Phys. Rev. Lett. 102, 092501(2009).
6) R. Chevrier et al.: Phys. Rev. Lett. 108, 162501(2012).
7) K. Sugimoto et al.: J. Phys. Soc. Jpn. 21, 213 (1966).
8) K. Asahi et al.: Phys. Lett. B 251, 488 (1990).
9) H. Shirai et al.: RIKEN Accel. Prog. Rep. 47, in print.
10) N. Yoshida et al.: Nucl. Instrum. Meth. B 317, 705(2013).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

β-NMR measurement in coincidence with β-delayed γ rays of 41 S
Y. Ichikawa,∗1 Y. Ohtomo,∗1,∗2 Y. Ishibashi,∗1,∗3 T. Suzuki,∗2 T. Sato,∗2 K. Imamura,∗1,∗4 T. Fujita,∗5
T. Furukawa,∗6 K. Asahi,∗2 T. Egami,∗7 C. Funayama,∗2 M. Hayasaka,∗8 C. Hirao,∗2 S. Kojima,∗2 T. Komine,∗2
M. Matsumoto,∗8 Y. Sakamoto,∗2 A. Takamine,∗9 D. Tominaga,∗7 H. Yamazaki,∗1 and H. Ueno∗1

∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

Counts / 0.5 keV

x 102
10000

Counts / 0.5 keV

(a)

7500
5000
2500

0
120
x 10
10000

125

130

140

145

150

(b)

5000
2500

545

550

555

560

565

570

575

580

Energy (keV)

x 102
2000

Counts / 0.5 keV

135

Energy (keV)

7500

0
540

(c)

1500
1000
500
0
750

755

760

765

770

775

780

Energy (keV)

Fig. 1. β-delayed γ rays of 41 S with energy of (a) 131 keV,(b) 554 keV and (c) 761 keV.

10000

Counts / 100 ms

We aim to measure the magnetic moment of theground-state 41 S, by combining the technique to produce spin-polarized RI beams1) and the method of βray-detected nuclear magnetic resonance (β-NMR). In
the previous experiment, the spin polarization realized
in the 41 S beams implanted in a CaS crystal was measured to be AP = −0.14(4)%2) using the adiabatic
field rotation (AFR) device3) . Since the AP value isthe product of the asymmetry parameter A for the βray emission and the degree of polarization P of 41 S,
the small AP value may be attributed to a cancellation of A when various β-decay branches are mixed.
Indeed, the decay scheme of 41 S has not been established other than the observation of several β-delayed
γ rays4) . In order to avoid a possible cancellation of
the A parameter, we have attempted to perform the βNMR measurement in coincidence with the β-delayed
γ rays, along with the normal β-NMR measurement5) .
The experiment was carried out at the RIPS at
RIBF. The beam production of 41 S and experimental setup are common to the normal β-NMR measurement5) . The β-delayed γ rays emitted from 41 S in the
CaS crystal located at the center of poles of the dipole
magnet were detected with two Ge detectors set at a
distance of 20 cm from the crystal. Each Ge detector
has a relative efficiency of 35%. The data acquisition
was system triggered by a γ-hit event defined by a logical OR of signals from the Ge detectors.
In this experiment, we have observed 3 β delayed γ
rays of 41 S with large yields, with energies of 131, 554
and 761, as shown in Fig. 1 (a), (b) and (c), respectively. To confirm the origin of these γ rays, the half
lives associated with these γ rays were deduced fromthe decay curve spectra synchronized with the beam
pulsing: 2.9 s for beam-on and 2.9 s for beam-off. Figure 2 shows the decay-curve spectra for the 131-keV γ
ray in the beam-off period. The decay-curve was fitted
to an exponential function on a constant background,and then, the half life was preliminarily determined
to be 1.99(5) s, which is in good agreement with theprevious value4) , and the origin was confirmed to be
41
S. Further analysis to obtain the NMR spectra incoincidence with these γ rays is in progress.

8000

6000

4000

2000

0

0

500

1000

1500

2000

2500

3000

Time (ms)Fig. 2. Decay-curve spectrum for 131-keV γ ray. The halflife was preliminarily determined to be 1.99(5) s.

References
1) K. Asahi et al.: Phys. Lett. B 251, 488 (1990).
2) H. Shirai et al.: RIKEN Accel. Prog. Rep. 47, 39(2014).
3) Y. Ishibashi et al.: Nucl. Instrum. Meth. B 317, 714(2013).
4) J. A. Winger et al.: AIP Conf. Proc. 455, 606 (1998).
5) Y. Ichikawa et al.: RIKEN Accel. Prog. Rep. 48 (inthis report).

RIKEN Nishina Center
Department of Physics, Tokyo Institute of Technology
Department of Physics, University of Tsukuba
Department of Physics, Meiji University
Department of Physics, Osaka University
Department of Physics, Tokyo Metropolitan University
Department of Physics, Hosei University
Department of Physics, Tokyo Gakugei University
Department of Physics, Aoyama Gakuin University- 65 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Interaction of 8B, unstable and loosely bound, with 208Pb: scattering andbreakup
C. Signorini,*1 A. Boiano,*2 C. Boiano,*3 C. Manea,*4 M. Mazzocco,*4 C. Parascandolo,*2 D. Pierroutsakou,*2
A.M. Sánchez-Benítez,*5 E. Strano,*4 D. Torresi,*4 M. La Commara,*2 H. Yamaguchi,*6 D. Kahl,*6 Y. Hirayama,*7
H. Ishiyama,*7 N. Imai,*6,*7 N. Iwasa,*8 S.C. Jeong, *7,*13 S. Kimura,*7 Y.H. Kim,*7 S. Kubono,*6,*9 H. Miyatake,*7
M. Mukai,*7 T. Nakao,*7 Y. Sakaguchi,*6 T. Teranishi,*10 Y. Wakabayashi,*9 Y.X. Watanabe,*7 C.J. Lin,*11 H.M. Jia,*11
L. Yang,*11 and Y.Y. Yang*12
The main motivation of this experiment was toinvestigate of the reaction dynamics induced by theradioactive ion-beam 8B, extremely loosely bound with Sp=137keV, at Coulomb barrier energy: i.e., reaction crosssection deduced from elastic scattering, as well as thetransfer and/or breakup processes. The 8B beam, provided
by the CRIB facility, was produced via the inverse
kinematics reaction 3He(6Li, n)8B. The primary 6Li beam
intensity ranged from 1 to 3 eA, resulting in a 8B intensityof ~104 Hz, with an energy of 50±1 MeV. The 6Li ion
source had to be retuned twice owing to the total
consumption of the lithium material. This resulted in a
beamtime loss of two days, allowing us to accumulate
statistics for four days beamtime on target. As expected, the8
B beam was contaminated by 7Be, via the 3He(6Li,pn)7Be
reaction, by 3He, recoiling from the 3He material of the
production gas target, and by some 6Li halo (originatingfrom the primary beam, that was around 108 times more
intense than the secondary one); thus, the 8B beam purity
achieved was approximately 20%. The contaminations were
not problematic since each beam species was identified via
a time of flight technique. The light charged particles
produced in the reaction were detected and identified withsix E-E telescopes, consisting of 40–50 m + 300 mdouble sided silicon strip detectors. The detectors werearranged symmetrically around the target at a distance of
pproximately 11 cm. All the detectors with the related
electronics were brought from Italy, INFN1. For theE-detectors we utilized for the first time, ASIC digitalelectronics, whereas we used for the E detectors low-noiseelectronics; these electronics were also fully developed in
Italy2,3. The charged particles identified were 8B, 7Be, 6Li,
4
He, 3He, and protons (Fig. #1), confirming our preliminary
estimates: namely, the existence of a consistentFig. 1. E-Eres identification of the different ions producedin the scattering of the cocktail 8B-7Be-3He beam onto a
208
Pb target.
amount of transfer (p transferred with 7Be out) and breakup
processes (→7Be+p, and possible subsequent 7Be breakup→3He+4He). Preliminary data from the angular distributionof the 8B elastic scattering confirm our expectations of astrong absorption occurring in the 8B-induced reactions.
In all the runs we were able to verify the good
capabilities of the homemade electronics2,3 for identifying
the various ions detected by the E silicon via the built-in
risetime detection. Fig. #2 shows a typical spectrum: signal
rise time vs. E, with the related ion identification.

*1

INFN, LNL, Legnaro
Department. of Physics and INFN, Napoli*3
INFN-Sezione di Milano*4
Dept. of Physics and Astronomy and INFN, Padova*5
University of Lisbon, Nuclear Physics Centre*6
CNS University of Tokyo, RIKEN
*7
KEK
*8
Department of Physics, Tohoku University*9
RIKEN Nishina Center*10
Department of Physics, Kyushu University*11
China Institute of Atomic Energy*12Institute of Modern Physics, Chinese Academy of Sciences*13
Institute for Basic ScienceFig. 2. Performances of the homemade electronics of thethin E detectors. The measurement of the risetime signal
vs. the energy loss allows for clear ion identification.

*2

References

1) E.Strano et al., Nucl. Instr. and Meth. B317(2013)657
2) C.Boiano et al.; IEEE Nucl.Science Symposium and Medical
Imaging Conference. (NSS/MIC)14-34(2012)865
3) C. Boiano et al.; IEEE Nucl.Science Symposium, Conference
Records 1-173(2009)1399.

- 66 -

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

First production of 10 Be beam at CRIB and 10Be+α resonant elastic
scattering
H. Yamaguchi,∗1 D. Kahl,∗1 S. Hayakawa,∗1 Y. Sakaguchi,∗1 and T. Nakao,∗2 for CRIB collaboration∗1∗2

silicon detectors, which had thicknesses of 20 µm and480 µm, were placed in the gas-filled chamber, consisting of a “∆E-E” telescope. The telescope was locatedat 482 mm from the Mylar entrance window, exactly inthe direction of the beam axis. The energy of the beam
degraded and the beam was stopped by the thick gas
target and α particles originating from elastic scatterings reached the telescope. The energy spectrum of the
α particles exhibited several peaks, as shown in Fig. 1.
In principle, α-cluster like resonances including theoretically predicted ones should be observed as peaksin the present measurement. In particular, two distinct peaks that likely correspond to resonances in 14 C
are observed at excitation energies of 14.3 MeV and
16 MeV; however, the resonant features of those are
yet to be investigated. The peak at the highest energy
of approximately 17 MeV could be due to background
events arising from impurities in the 10 Be beam andshould be eliminated in the main run.
In summary, we successfully produced a 10 Be beamat CRIB for the first time and also showed that the resonant scattering measurement is feasible. The actual
measurement for 7.5 days will be performed in 2015.
140
120

Count (for 9 hours)

α-cluster states are known to occur in many nuclei,
including isotopes of the carbon nucleus. Among the
α-cluster states, linear-chain cluster states have been
considered as exotic and of interest for a long time.
Although there have been many theoretical investigations, no clear experimental evidence has been obtained for such states thus far.
By performing an antisymmetrized molecular dynamics (AMD) calculation, Suhara and En’yo1,2) ob++
tained a band (0+5 , 26 , 46 ) that could be explained
as linear-chain cluster levels of 14 C. It was predictedthat these levels appear a few MeV or more above the10
B+α threshold, unlike the prolate bands in the studyof Oertzen et al.3) The investigation2) shows that the
AMD wave function has a configuration in which two
α particles and two neutrons are located close to eachother, while the remaining α particle is relatively faraway. This implies that states having such a linearchain configuration could be accessed from the 10 Be+αchannel.
The aims of the present work are 1) to search fora linear-chain configuration via 10 Be+α resonant scattering, and 2) to determine the resonant parametersof the high excited states (13-18 MeV) of 14 C, which
are still mostly unknown, in order to elucidate on thecluster-band structure. The experimental method issimilar to that used in previous studies.4,5)
The study was conducted at the low-energy
radioactive-isotope (RI) beam separator CRIB. The
10
Be beam at CRIB was first produced on January
17-19, 2014. Using a 5.57 MeV/u primary 11 B beamfrom the AVF cyclotron and a 500-Torr cryogenic deuterium target, 10 Be particles were produced via the11B(d, 3 He)10 Be reaction in inverse kinematics. The+
4 charge state was selected using the D1 dipole magnet of CRIB. The produced 10 Be4+ beam was contaminated with a small amount of 10 B4+ , which was mostly
excluded by inserting a 0.7 µm-thick Mylar film as acharge stripper at the F1 focal plane. The highest 10 Be
beam production rate was 2 ×104 pps at the final focal
plane (F3). The beam energy was 3.51 MeV/u before
reaching parallel-plate avalanche counters (PPACs) installed for the beam monitoring.
We also performed a test measurement of α resonant scattering using a chamber filled with helium gas
at 760 Torr, which served as the target for elastic scattering. The chamber had a window covered with a 25
µm-thick Mylar film at the beam entrance. A pair ofCenter for Nuclear Study, University of Tokyo
Advanced Science Research Center, Japan Atomic Energy
Agency- 67 -

Ex~16 MeV

100
80

Ex~14.3 MeV
60
40
20
0
0

2

4

6

8

10

12

14

16

18

20

Measured alpha particle energy (MeV)

Fig. 1. Energy spectrum of α particles. The data wereaccumulated for 9 hours.

References
1) T. Suhara and Y. Kanada-En’yo: Phys. Rev. C 82,
044301 (2010).
2) T. Suhara and Y. Kanada-En’yo: Phys. Rev. C 84,
024328 (2011).
3) W. Oertzen, et al.: Eur. Phys. J. A21, 193 (2004).
4) H. Yamaguchi et al.: Phys. Rev. C 83, 034306 (2011).
5) H. Yamaguchi et al.: Phys. Rev. C 87, 034303 (2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Investigation of the waiting point 22Mg in the rp-process
N. N. Duy,＊1, *2 L. H. Khiem,＊2 S. Kubono,＊3 H. Yamaguchi,＊4 D. Kahl,＊4 and N. K. Uyen*5
Nucleosynthesis in stars occurs via several reaction
chains, including a combination of the (α,p)-process,(p,γ)-process, and β+-decay. A nucleus is a waiting point if
the (,p) or (p,γ) reaction rate is so low that the nuclear
processing has to wait for β+-decay. Since thenucleosynthesis grows to the 22Mg nucleus via thefollowing reaction chains, 14O(,p)(p,)18Ne(,p)(p,)22Mg(,p)(p,)26Si(,p)(p,)30S(,p)(p,)34Ar(,p)(p,)38K, there
are three possible ways by which the reactions can proceed
through 22Mg: 22Mg(β+)22Na, 22Mg(α,p)25Al, and22Mg(p,γ)23Al. Because of the small Q-value (Q = 0.125
MeV) of the (p,γ)-reaction, it is thought that thephotodisintergration of 23Al prevents a significant part of
the flow through this reaction. In addition, at
high-temperature condition, i.e., T 9 = 1 – 10 GK, the22Mg(α,p)25Al reaction was thought to be dominant. If thereaction rate of 22Mg(α,p)25Al is lower than the rate of beta
decay, the nucleosynthesis must await the decay from 22Mg,
and subsequently, the 22Mg nucleus becomes a waiting point.
To investigate the potential waiting of 22Mg, we measured
the 22Mg+ reaction and determined the resonance states1)of 26Si that are used to calculate the reaction rate of22
Mg(,p)25Al under such stellar conditions. According to
the results of a previous work,2) we could estimate the rateof the (α,p)-process, (p,γ)-process, and β+-decay in 22Mg.
The reaction rate of 22Mg(,p)25Al was determined byusing the resonance states of 26Si obtained from alphascattering in the 22Mg+ experiment. The calculation was
performed by using following expression:
N A  v8.08  109  T6 
tot

3/ 2

 11605Ei 
 (1)
T6


   exp  iiwhere , (), Ei, and T6 are reduced mass, resonancestrength, resonance states, and temperature in million
Kelvin, respectively. The resonance strength was calculated
by assuming that of the proton occupied 10% of the total
width. As shown in Fig. 1, the rates of the (α,p) reaction
corresponding to the first resonance is the highest. The
reaction rate is low under concerned stellar conditions, witha value in the range of 10-30 – 10-7. The speed of the (α,p)
reaction, which depends on the abundance of isotopes in thestellar environment, and that of beta decay were obtained
from the following equations:R p 



 X
m



R   ln 2 / T1/ 2 ,NA v pwhere , Xa, NA<v>, ma, and T1/2 are the density of thematerials in the stellar environment, abundance of 4He, rateof the (α,p) reaction, mass of 4He, and half-life of 22Mg.
According to the rates obtained in the previous work, 2) we
could determine the speed of the (p,γ) reaction. The results
show that in the temperature range of T 9 = 1 – 10 GK, the(p,γ) reaction is the dominant. Table 1 compares the three
processes.

Fig. 1. Rates of the reaction 22Mg(,p)25Al calculated byusing the resonance states of 26Si via alpha scattering of22
Mg.
Table 1. Speed of the reactions and beta decay
T9
(GK)
1.0
1.5
2.0
2.5
10

Rp
(reaction/s)
2.99E-06
1.79E-04
1.26E-03
3.90E-03
7.50E-02

Rp(reaction/s)
7.80E+03
2.47E+04
4.92E+04
7.80E+04----

R +(decay/s)
0.17890.17890.17890.17890.1789Since the speed of the (p,γ) reaction is much higher thanthat of the others, it does not wait for beta decay. Therefore,
under the conditions of X-ray burst and Type-II supernovae,
the 22Mg nucleus does not act as a waiting point.
Subsequently, beta decay does not occur. Once the beta
decay is skipped, the 22Na unstable isotope which decays
beta-plus (+) to the excited state of 22Ne, which de-excites
to ground state by emitting gamma rays with energy of
1.275 MeV, cannot be formed. Therefore, such gamma rays
have not been observed by satellites up to date. In addition,
the 22Ne/20Ne ratio changes, which is one of the causes of
the Ne-E problem.

(2)
(3) 

Department of Physics, Dong Nai University.
Institute of Physics, Vietnam Academy of Science and Technology.
＊3
RIKEN Nishina Center.
＊4
Center for Nuclear Study, The University of Tokyo.
＊5
Department of Physics, HCM University of Technology and Education.
＊1＊2

References

1) N. N. Duy et al: RIKEN Accel. Prog. Rep. 47, 43 (2015).
2) J. J. He et al: Phys. Rev. C 76, 1 (2007).

- 68 -

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Production of Lv isotope in the hot fusion reaction of248
Cm+48 Ca at E ∗ =38.4 MeV
D. Kaji,∗1 K. Morita,∗1,∗2 K. Morimoto,∗1 C. Berner,∗1,∗3 H. Haba,∗1 Y. Komori,∗1 M. Murakami,∗1,∗4
Y. Narikiyo,∗1,∗2 M. Takeyama,∗1,∗5 K. Tanaka,∗1,∗6 T. Tanaka,∗1,∗2 Y. Wakabayashi,∗1 and S. Yamaki∗1,∗7
In 2013, a gas-filled recoil ion separator (GARIS)
was employed to study the production of Lv (Livermorium, Z=116) isotopes in the hot fusion reactionof 248 Cm+48 Ca at the excitation energy of compound
nucleus E ∗ =41.5 MeV1) . As a result, five correlated
decay chains were observed. On the basis of the assignments of the precedent studies2–4) , two of the eventswere attributed to the decays of 293 Lv (3n), and threeof them were assigned to the decays of 292 Lv (4n).
With the aim of clear identification of these nuclides,
we started to measure the excitation function in thereaction of 248 Cm+48 Ca → 296 Lv∗ .
The experimental setup was almost the same as thatused in our previous work1) using 48 Ca11+ beam with
261.6 MeV. In this work, the 248 Cm target was irradiated with a 258 MeV 48 Ca11+ beam from RIKEN
heavy-ion linear accelerator RILAC. Total beam dose
was 5.0×1018 during a net irradiation time of 14.2
days. The average beam intensity on the target was
0.68 particle µA. The reaction products were separated
in-flight from projectiles and other by-products using
GARIS, and then they were guided into the focal plane
detection system after they passed through the timeof-flight (TOF) detector5) . The separator was filledwith He gas at 73 Pa. Magnetic rigidity for measuring
the Lv isotope was set to be 2.174 Tm. Then, the typical trigger rate at the focal plane was 58 cps at 0.89
particle µA.
Seventy-three events, which were anti-coincided with
TOF detectors, with energies above 100 MeV were observed. Two events among their fission events were
found to be correlated with preceding α-particles andimplanted evaporation residue (ER). Observed decay
chains are shown in Fig. 1. The first chain, which wasobserved on September 22, 2014, consists of three consecutive α-decays followed by SF. Decay properties of
all nuclides in the first chain agree well with those of
the decay chain from 293 Lv reported in early works2–4) .
The second chain consists of two consecutive α-decays
followed by SF. Assuming the first α originating from293
Lv is not detected in the second chain, the chain
looks the same as the first series because decay properties of two α and SF in the second chain agree well
∗1
∗2
∗3
∗4
∗5
∗6
∗7

RIKEN Nishina Center
Department of Physics, Kyushu University
Faculty of Physics, Technical University Munich
Graduate School of Science and Technology, Niigata University
Department of Physics, Yamagata University
Graduate School of Science, Tokyo University of Science
Department of Physics, Saitama University- 69 -

with those of α2 and α3 followed by SF in the firstone. However, the missing probability is estimated tobe 0.3% by considering the dead time for data acquisition and counting rate of the FPD. By the low missing
probability, we can not conclude whether the second
chain is from 293 Lv or the other nuclide that is provided directly (and emitted the 9.71 MeV α-particle).







 

α
α
α











α

α













γ



Fig. 1. Observed decay chains. Strip number, kinetic energy, T OF , and position of ER are given as well as
decay energy and time, and position for each α-decay
and/or SF .

The cross-section was deduced to be 0.9+2.1−0.7 pb for
3n evaporation channel assuming the transmission of
GARIS to be 35%. The cross section agrees well with∗the previously reported value of 1.1+1.7−0.7 pb at E =40.9
MeV2,3) . On the other hand, we did not observe thedecay chain originating from 4n. The cross-section
limit was 1.64 pb for 4n although the reported value is
3.3+2.5−1.4 pb.
For further understanding from the reaction mechanism, we will measure the excitation function at anenergy higher than 41.5 MeV.
References
1) K. Morita et al.: RIKEN Accel. Prog. Rep. 47, (2014).
2) Yu. Ts. Oganessian et al.: JINR preprint, E7-2004-160,
p.1 (2004).
3) Yu. Ts. Oganessian et al.: Phys. Rev. C70, p.064609(2000).
4) S. Hofmann et al.: Eur. Phys. J. A48, p.62 (2012).
5) D. Kaji et al.: RIKEN Accel. Prog. Rep. 47, (2014).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Production of 215U and 216U and attempt to produce 219Np and 220Pu
Y. Wakabayashi,∗1 K. Morimoto,∗1 D. Kaji,∗1 H. Haba,∗1 M. Takeyama,∗1,∗2 S. Yamaki,∗1,∗3 K. Tanaka,∗1,∗4
K. Nishio,∗5 M. Asai,∗5 Y. Komori,∗1 M. Murakami,∗1,∗6 T. Tanaka,∗7 A. Yoneda,∗1 and K. Morita∗1,∗7
Theory1) predicts that nuclei with N = 126 exist up
to Fm (Z = 100) because of the fission barrier arisingfrom the ground-state shell effect. The heaviest N =126 nuclei reported so far is 218 U (Z = 92). In thisprogram to study nuclei with N = 126, we attempt
to produce heavier nuclei such as 220 Pu. In previous
experiments, a new isotope 216 U, which is the daughter
nucleus of 220 Pu and 215 U, were observed2) .
We performed an experiment at the RIKEN Linear
Accelerator (RILAC) facility. We used 82 Kr ion as anincident beam and 136,137,138 BaCO3 , N at La2 O3 , andN at
CeO2 as targets to study the 82 Kr + 136,137,138 Ba,
139
La, and 140 Ce reactions. Each target material
was prepared by sputtering on 0.8–1.1-µm-thick aluminum foils so as to achieve a thickness of 300–500µg/cm2 , and it was also covered with 40 µg/cm2 ofaluminum.The 82 Kr beams with energies of 365, 381
and 386 MeV were used to bombard these target foils
mounted on a rotating target.
Evaporation residues (ERs) were separated from thebeam particles and other products using a gas-filled recoil ion separator (GARIS), and they were implanted
into a position-sensitive strip detector (PSD; 58 × 58mm2 ). The PSD was boxed in four Si detectors (SSD)
to catch α particles escaping from the PSD. Two timing detectors were set in front of the PSD to measure2

Previous(a)1∆T(ER - αp)

T1/2 (exp.) of Eα1(exp.)= 2.6 +3.6
ms
-1.0

0
2

4

∆T(αp - αd)T1/2 (exp.) = 18

+11
-5 ms
+20

T1/2 (ref.) = 30 -10 ms+0.5

T1/2 (exp.) = 0.7 -0.2 sec
T1/2 (ref.) = 1.3 (2) sec ∆T(αd - αgd)

1

0

1

Previous(b)
216

U (αp)Eα3

Eα1 (exp.)= 8390 (33) keV

Eα1

Table 1. α-decay events of 215 U and 216 U. The time andposition difference between the implanted ERs and the
α-decay are ∆T and ∆X, respectively. Eb represents
the 82 Kr beam energy at the center of the target.

Eα2

0

1

0
2

2

the time-of-flight (TOF) of the ERs. Time information was also used to distinguish between the α-decay
events in the PSD and the recoil implantations. A Gedetector was placed 6 mm behind the PSD to measure
the γ-rays coinciding with the α-decays. The isotopes
were identified by using an α-decay chain with known
α-decay properties of the descendants and the position
correlations between the implanted ERs in the PSD
and the subsequent α-decays.
In this experiment, we confirmed the production of
215
U and 216 U by observing one chain and six chains,respectively, including the candidates of new transitions. For the decay chains of 216 U, the α-decay energies and decay times are shown in Fig. 1. These
decay events and cross sections are summarized in Table 1, and we labeled the decay energies with Eα1 ,Eα2 , and Eα3 temporarily. For a new transition, Eα2of 216 U may be a transition from isomer-state in 216 U
to ground-state in 212 Th as well as an isomer state of218
U with the α-decay energy of 10678 keV3) . In theattempt to produce 219 Np and 220 Pu using the 82 Kr+ 139 La and 140 Ce reactions, cross section upper limits of 28 pb and 46 pb, respectively, were obtained.
Further discussion, such as the interpretation of newtransitions, is ongoing.

-1 0

1

2

3

4

log10(T1/2)(sec)

5

212

3

Th (αd)2Eα (exp.) = 7810 (21) keV

216

U(Eα1 )Eα (ref.) = 7802 (10) keV

1
0
3

208

Ra (αgd)2

Eα (exp.) = 7124 (23) keV

1

Eα (ref.) = 7133 (5) keV

0216

6000 7000 8000 9000 10000

Energy(keV)

Fig. 1. α-decay time (a) and energy (b) spectra for 216 U.
The previous results are indicated by dotted arrows.
Each ∆T indicates the time difference between each decay generation (αp , αd , and αgd ). The labeled energies
Eα1 , Eα2 , and Eα3 for 216 U are specified. Observed αdecay energies and half-lives are written with reported
ones except for 216 U.

U(Eα2 )
216
U(Eα3 )

Eα(keV)
84082)
8371
8379*
10518
10459*
8254
8265*

∆T
(ms)
6.98
3.95
0.43
2.50
0.43
1.81
3.40

|∆X|
(mm)
0.2
0.2
0.5
0.2
2.3
0.1
0.2

U
84362)
5.82
1.0(Eα1 )
215
U
82302)
0.64
0.4(Eα2 ) 8283
2.10
0.2
* Sum energy of PSD and SSD.
215

Reaction (Eb ) &Cross section
137
Ba+82 Kr (366)→ 216 U + 3n
22+14
−9 pb
136

Ba+82 Kr (350)→ 216 U + 2n
58+77
−38 pb136

Ba+82 Kr (373)→ 215 U + 3n
31+28
−18 pb

References
∗1
∗2
∗3
∗4
∗5
∗6
∗7

RIKEN Nishina Center
Department of Physics, Yamagata University
Department of Physics, Saitama University
Tokyo University of Science
Japan Atomic Energy Agency
Department of Chemistry, Niigata University
Department of Physics, Kyushu University

1) H. Koura: Prog. Theor. Exp. Phys. 2014, 113D02(2014).
2) Y. Wakabayashi et al.: RIKEN Accel. Prog. Rep. vol.47,xxii (2014).
3) A.P. Leppänen et al.: Eur. Phys. J. A25, Supplement 1,
183 (2005).

- 70 -

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Search for new isotopes in the region around Z = 33 using thein-flight fission of a 238 U beam at 345 MeV/nucleon
Y. Shimizu,∗1 T. Kubo,∗1 N. Inabe,∗1 D.S. Ahn,∗1 N. Fukuda,∗1 K. Kusaka,∗1 D. Murai,∗1,∗2 M. Ohtake,∗1
H. Suzuki,∗1 H. Takeda,∗1 Y. Yanagisawa,∗1 K. Yoshida,∗1 Y. Hirayama,∗3 Y. Ichikawa,∗1 N. Imai,∗4 T. Isobe,∗1
N. Iwasa,∗5 S.C. Jeong∗3 D. Kim,∗6 E.H. Kim,∗6 H. Miyatake,∗3 M. Mukai,∗3 H. Otsu,∗1 H. Sato,∗1
T. Sonoda,∗1 and A. Yagi∗7
A new isotope search experiment in the neutronrich region around Z = 33 was performed in November 2014, aiming to expand the frontier of accessible
neutron-rich exotic nuclei. In this experiment, the nuclei of interest were produced by the in-ﬂight ﬁssion of
a 345 MeV/nucleon 238 U beam colliding with a 4.00mm-thick Be target. The primary beam intensity was
10.8 particle nA on average. Fission fragments wereseparated and identiﬁed using the superconducting inﬂight separator BigRIPS1) . In order to separate andpurify the RI beams, two wedge-shaped energy degraders were placed at the F1 and F5 dispersive foci.
The typical counting rate at the F3 and F7 achromatic
foci were 30.1 kHz and 1.88 kHz, respectively. Table 1
summarizes the experimental conditions.

Figure 1 shows a two-dimensional PID plot of Z
versus A/Q. The solid red line indicates the limit ofpreviously identiﬁed isotopes. The relative root meansquare (rms) Z resolution and the relative rms A/Q
resolution achieved were typically 0.57% and 0.055%,
respectively. We can see some candidates for new isotopes such as 93 As, 96 Se, and 99 Br.
Detailed analysis is currently in progress.

40
38

Target (mm)Be 4.00
Bρ a (Tm)
8.087
Degrader at F1 (mm)Al 2.82
Degrader at F5 (mm)Al 2.99
F1 slit (mm)+64.2 / −64.2
F2 slit (mm)+20.0 / −12.0
F5 slit (mm)+120.0 / −120.0
F7 slit (mm)+15.0 / −15.0
94
Central particle
As
Irradiation time (h)97.3Live time of DAQ (%)
66.1
Trigger rate (kHz)
1.24
Total dose
2.35 × 1016a
The values from the magnetic fields of the first dipole
magnet.

36

∗1
∗2
∗3
∗4
∗5
∗6
∗7

RIKEN Nishina Center
Department of Physics, Rikkyo University
High Energy Accelerator Research Organization (KEK)
Center for Nuclear Study (CNS), University of Tokyo
Department of Physics, Tohoku University
Institute for Basic Science (IBS)
Department of Physics, Osaka University- 71 -Z

Table 1. Summary of the experimental conditions.

Particle identiﬁcation (PID) was performed using
the ∆E-TOF-Bρ method in which the energy loss(∆E), time of ﬂight (TOF), and magnetic rigidity (Bρ)
were measured to allow the event-by-event determination of atomic number Z and mass-to-charge ratio A/Q
of fragments2) . The PID was conﬁrmed by measuring
the delayed γ-rays emitted from short-lived isomers,such as 95 Kr and 94 Br, by using two clover-type highpurity germanium detectors placed at the F7 achromatic focus; this technique is called isomer tagging.

Known New

42

34
32
30
28

y
r
a
in

m
i
l
re

P
2.6

2.65

2.7

2.75

2.8

2.85

2.9

A/Q
Fig. 1. Two-dimensional PID plot of Z versus A/Q. Redline indicates the limit of known isotopes.

References
1) T. Kubo et al.: Nucl. Instr. Meth. B 204, 97 (2003).
2) N. Fukuda et al.: Nucl. Instr. Meth. B 317, 323 (2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Search for new neutron-rich isotopes with Z ∼ 55–70
using a 345 MeV/nucleon 238 U beam
N. Fukuda,∗1 N. Inabe,∗1 D. Kameda,∗1 H. Suzuki,∗1 H. Takeda,∗1 D.S. Ahn,∗1 D. Murai,∗1,∗2 K. Yoshida,∗1
K. Kusaka,∗1 Y. Yanagisawa,∗1 M. Ohtake,∗1 Y. Shimizu,∗1 Y. Sato,∗1 H. Sato,∗1 H. Otsu,∗1 H. Baba,∗1
G. Lorusso,∗1 P.-A. Söderström,∗1 T. Isobe,∗1 N. Imai,∗3 M. Mukai,∗1,∗4 S. Kimura,∗4 H. Miyatake,∗4
N. Iwasa,∗5 A. Yagi,∗6 R. Yokoyama,∗3 O.B. Tarasov,∗7 H. Geissel,∗8 and T. Kubo∗1

∗4
∗5
∗6
∗7
∗8

59+
Pr
Pr59+

ZZ

60
60

Known frontier
frontier
Known

1044
10
1033
10

55
55

1022
10

50
50
45
45
75
75

rryy
iinnaammiill
PPrree

2.45
2.45

2.5
2.5

2.55
2.55

(b)
(b)

10
10
2.6 2.65
2.65
2.6
A// Q
Q
A

2.7
2.7

2.75
2.75

2.8
2.8

Known frontier
frontier
Known

70
70

1033
10
1022
10

65
65
60
60
55
55

11

68+
yy
Er68+
Er
nnaarr
mii
iim
l
l
e
e
PPrr

10
10

176
176

2.45
2.45

2.5
2.5

2.55
2.55

2.6
2.6 2.65
2.65
A // Q

2.7
2.7

2.75
2.75

2.8
2.8

11

Setting
Production target
Isotope tuned
Bρ of D1
Degrader at F1
Degrader at F5F1 slitF2 slitF5 slitF7 slitAverage intensity
Running time

Particle identiﬁcation (PID) was based on the TOFBρ-∆E method to deduce Z and the mass-to-charge
ratio (A/Q)8) . The preliminary PID plots of Z versus A/Q are shown in Fig.1. The relative root meansquare A/Q and Z resolutions are typically 0.037% and0.45%, respectively, for the 161 Pr setting, and 0.047%
and 0.88%, respectively, for the 180 Er setting. A totalof 18 new isotopes have preliminarily been identiﬁed
ranging from Z = 56 to 69. Further analysis is currently in progress.

Pr setting
Be 4.0 mm
161
Pr
7.527 Tm
Al 1.4 mm
Al 1.4 mm±64.2 mm+10/−3 mm±120 mm±25 mm
12.6 pnA
54.6 h
1.55 × 1016
particles

Er setting
Be 6.9 mm
180
Era)6.311 Tm
Al 0.98 mm
Al 0.96 mm+32.1/−42.8 mm+4/−3 mm±120 mm±25 mm
3.39 pnA
44.2 h
3.36 × 1015
particles

References
1) T. Kubo: Nucl. Instr. Meth. B 204, 97 (2003).
2) T. Ohnishi et al.: J. Phys. Soc. Jpn. 79, 073201 (2010).
3) D. Kameda et al.: RIKEN Accel. Prog. Rep. 46, 20(2013).
4) Y. Shimizu et al.: RIKEN Accel. Prog. Rep. 47, 47(2014).
5) H. Suzuki et al.: Nucl. Instr. Meth. B 317, 756 (2013).
6) D. Kameda et al.: RIKEN Accel. Prog. Rep. 47, viii
(2014).
7) O.B. Tarasov and D. Bazin: Nucl. Instr. Meth. B 266,
4657 (2008).
8) N. Fukuda et al.: Nucl. Instr. Meth. B 317, 323 (2013).

of the first stage of BigRIPS.

∗3

159
159

Table 1. Summary of the experimental conditions.

a) Hydrogen-like (Q = 67) ions were chosen in the first half

∗2

(a)
(a)

Fig. 1. Z versus A/Q particle identification plots obtainedin the Pr (a) and Er (b) settings. The known frontiers
are indicated by the red lines.

Total dose of 238 U

∗1

65
65

Z
Z

Since the commissioning of the BigRIPS separator1)
in 2007, an extensive search for new isotopes has been
conducted to expand the region of accessible exotic
nuclei. By the end of 2013, about 100 new neutron-richisotopes had been observed using the in-ﬂight ﬁssionof a 238 U beam2–4) , and 4 new neutron-deﬁcient nuclei
had been observed by the projectile fragmentation of
a 124 Xe beam5) . In April 2014, we searched for new
neutron-rich isotopes with the atomic number Z ∼ 55–
70 for the second time since the 2011 experiment3) ,with an increased beam intensity.
The neutron-rich isotopes were produced by the inﬂight ﬁssion of a 238 U beam at 345 MeV/nucleon.
The maximum beam intensity was approximately 12.5
pnA. The ﬁssion fragments were collected and separated with the BigRIPS. The experimental conditions
are summarized in Table1. We adopted two diﬀerentBρ settings of the separator, each targeting new isotopes around 161 Pr (Pr setting) and 180 Er (Er setting).
The settings were determined using the measured crosssections6) and the detailed simulations with the code
LISE++7) .

RIKEN Nishina Center
Department of Physics, Rikkyo University
Center for Nuclear Study, University of Tokyo
High Energy Accelerator Research Organization (KEK)
Department of Physics, Tohoku University
Department of Physics, Osaka University
NSCL, Michigan State University
GSI- 72 -

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Study of particle identification and RI beam separation for the Z~80 region
using projectile fragmentation of 238U
N. Inabe,*1 N. Fukuda,*1 H. Takeda,*1 H. Suzuki,*1 Y. Shimizu,*1 D. Murai,*2 D. S. Ahn,*1 H. Sato,*1 Y. Sato, *1
K. Kusaka,*1 Y. Yanagisawa,*1 M. Ohtake,*1 K. Yoshida,*1 M. Sako,*1 N. Imai,*3 S. Kimura,*3 M. Mukai,*3 H. Miyatake,*3
N. Iwasa,*4 and T. Kubo*1
An atomic number of Z~80 produced through a
projectile fragmentation of 238U is the next area for RI beam
production at the BigRIPS.1) In this area, charge-state
distributions are broad, which causes some problems for
production concerned with both particle identification (PID)
and isotope separation. To study this effect, we performed
a test experiment to produce RI beams of high Z.
The test experiment was carried out using a 345 MeV/u238
U beam. To study PID, RI beams were produced by the238
U beam in low counting rates of ~2 x105 pps so as tomake PID easy by sometimes mixing the 238U primary beamof the charge state 92+ at F1. The production target was
5.79-mm-thick Be and the magnetic rigidity (B) of the first
dipole D1 was 6.001 Tm. Degraders were not used at F1and F5. The F1 slits were set to produce a momentum
byte in the range between -3% and 0.1% when the primarybeam was not mixed and between -3% and 0.5 % whenmixing it. The PID was performed by determining Z and
A/Q on an event-by-event basis using the E-TOF-B
method. E was measured by MUSIC at F7 and TOF was
measured using two plastic scintillators at F3 and F7. B
was determined by track reconstruction using positions andangles measured by PPACs located at F3, F5, and F7.
Total kinetic energy (TKE) was also measured using by NaI
at F7 to determine A.
Figure 1a and b show the PID spectra of A/Q vs. Z for Z> 30 and Z > 85, respectively. We can see not only
projectile fragments but also fission fragments below Z~70
in Fig. 1a. Fig. 1c shows the similar plot as Fig. 1b when
primary beams are mixed. We can clearly see four charge
states of 238U, which are produced by changing the charge
state from 92+ in the scintillator at F3. Resolutions of Z
are 0.58 % for Z~90 and 0.41 % for Z~50. The worse
resolution in the high-Z area might be attributed to charge
state straggling, which broadens energy loss spectra when
passing through a detector with some charge states.
We performed the PID of U isotopes. Fig. 2 shows an
A/Q spectrum of U produced by cutting with Z= 92±0.3.
We identified the main peaks of A/Q > 2.55 but could not
assign those of low A/Q because of overlap with isotopes of
Z=91. The resolution of A/Q is 0.05%. We tried to examine
whether other small peaks exist in large peaks, for example,
233 89+U in the 236U90+ peak but we could not determine thisbecause of the quenching of the TKE counter.
In order to study isotope separation, we produced RI
beam of which the central orbit was 226Bi82+ with the

7-mm-thick Be target. Bof the first dipole was 6.13 Tm.
The degrader at F1 of 0.3 mm and momentum acceptanceof ±3% were used to produce many types of isotopes atthe same time such as a search for new isotopes. The
isotopes were not well-separated in this experiment owing
to large unexpected contaminants of fission fragments with
Z~60 and high counting rates of ~100 kHz/pnA. Thesephenomena have not been predicted by the simulation.

Fig. 1aZ vs. A/Q plot (Z>30)

Fig. 1b Z vs. A/Q plot (Z>85)

Fig. 1c Z vs. A/Q plot on mixing with the primary beam.

Fig.2 A/Q spectrum of U isotopes
Reference
1) T. Kubo: Nucl. Instr. Meth. B 204, 97 (2003).

RIKEN Nishina Center
Department of Physics, Rikkyo University
＊3
KEK
＊4
Department of Physics, University of Tohoku＊1＊2- 73 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

Production cross section measurements of radioactive isotopes
produced from a 124Xe beam at 345 MeV/u by the BigRIPS
separator
H. Suzuki,∗1 N. Fukuda,∗1 H. Takeda,∗1 D. Kameda,∗1 Y. Shimizu,∗1 D.S. Ahn,∗1 D. Murai,∗1,∗2 H. Sato,∗1
K. Yoshida,∗1 K. Kusaka,∗1 Y. Yanagisawa,∗1 M. Ohtake,∗1 Y. Sato,∗1 N. Inabe,∗1 and T. Kubo∗1∗1∗2

RIKEN Nishina Center
Department of Physics, Rikkyo University- 74 -

Production cross section (mb)

102

(a)

100

Zr
Mo

Se

-2

Kr

10

Ru
Sr

10-4

Zr

Mo

-6

10

Ru

-8

10

10-10

Pd

Cd

Sn

Te

95

100

105

Ag

In

95

100

-12

10

65

70

75

80

85

90

110

Mass number
102

Production cross section (mb)

We have measured the production rates and the production cross sections for a variety of radioactive isotopes (RIs), which were produced from a 124 Xe beamat an energy of 345 MeV/u using the BigRIPS separator.1) Proton-rich isotopes with atomic numbers
Z = 34−52 were produced by the projectile fragmentation of the beam on a 4-mm thick Be productiontarget. The particle identification of RIs was based on
the TOF-Bρ-∆E method.2)
The production cross sections were deduced fromthe measured production rates and the transmission
efficiency in the BigRIPS separator, which was simulated with the LISE++ code.3) In the LISE++ simulation, the parametrization for momentum distribution was adjusted, because the exponential tails in the
low-momentum regions fell off faster than those in the
LISE++ calculation with the original parametrization
for the 345-MeV/u 124 Xe + Be reaction.4)
Figure 1 shows the production cross sections of
RIs obtained in three experiments, including our
first 124 Xe-beam experiment4) with predictions of the
EPAX empirical cross-section formulae. The type ofsymbols represents the experiment from which the data
were obtained. The filled symbols indicate that the
distribution peak is located inside the slit opening at
each focus, while the open symbols indicate that thepeak is located outside the opening. The deduced crosssections of the same isotopes obtained in different settings / experiments were fairly consistent with eachother, even though some isotopes were accepted only
their low-momentum tails in the separator. This indicates the reliability of our measurements and simulations with LISE++ .
The solid and dashed lines in Fig. 1 show thecross sections predicted from the empirical formulae
EPAX3.1a5) and EPAX2.15,6) respectively. EPAX3.1apredicts the cross sections better than EPAX2.15,
which overestimates them. The measured cross sections of RIs with a wide range of Z are fairly well reproduced by EPAX3.1a, although some isotopes show systematic discrepancies in the highly neutron-deficientregion. For 100 Sn, our experimental cross section at
345 MeV/u is approximately 1/6 of that predicted by
EPAX3.1a. Further, the discrepancy becomes significant in the large Z region.

(b)

100

Nb
Br

10-2

Tc
Rb
Y

-4

10

Rh

Nb

Tc

10-6
10-8
-10

10

10-12

Sb

Xe-beam first exp.
73
Sr exp.
100
Sn exp.
EPAX3.1a
EPAX2.15
65

70

75

80

85

90

105

110

Mass number

Fig. 1. Production cross sections of RIs produced in the124
Xe + Be reaction at 345 MeV/u with the predictions of EPAX parametrization. (a) Results for even-Z
isotopes. (b) Results for odd-Z isotopes.

References
1) T. Kubo: Nucl. Instrum. Meth. Phys. Res. B 204, 97(2003).
2) N. Fukuda et al.: Nucl. Instrum. Meth. Phys. Res. B
317, 323 (2013).
3) O. B. Tarasov and D. Bazin:
LISE++ site,
http://lise.nscl.edu, Michigan State University.
4) H. Suzuki et al.: Nucl. Instrum. Meth. Phys. Res. B
317, 756 (2013).
5) K. Sümmer: Phys. Rev. C 86, 014601 (2012).
6) K. Sümmer and B. Blank: Phys. Rev. C 61, 034607(2000).

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Production cross section measurements for fragments of 70 Zn beam

We measured the production yields and production cross sections of radioactive isotopes (RIs) in
the neutron-rich region with the atomic number Z =16 ∼ 24 produced from an 70 Zn beam at an energyof 345 MeV/nucleon by using the BigRIPS separator1) . Neutron-rich RIs were produced through projectile fragmentation on a 10-mm Be target, and theparticle identification (PID) of RIs was performed using the TOF-Bρ-∆E method. The energy loss (∆E)
was measured using an ion chamber at F7. The timeof-flight (TOF) between F3 and F7 was measured using
plastic scintillators and the trajectory was measured
at F3, F5, and F7 by using Parallel Plate Avalanche
Counters(PPACs).
The Bρ of BigRIPS was set to the rigidity corresponding to the center of the momentum distributionof 56 Ca, and the PID was confirmed by the isomers of56
Sc and 59 Ti. The experimental conditions for 56 Ca
setting are listed in Table 1. Figure 1 is a PID plot
showing the relation between the atomic number (Z)and mass-to-charge ratio (A/Q). Background eventswere eliminated by the correlations among phase-space
profiles by using the PPAC, pulse-height, and timing signals from the plastic scintillators; reaction loss
events in the ionization chamber; pile-up events using
plastic scintillators and the ionization chamber; particle trajectories between two different foci; and charge
state change at F5.

Atomic number Z

D. S. Ahn,∗1 H. Suzuki,∗1 N. Fukuda,∗1 H. Takeda,∗1 Y. Shimizu,∗1 D. Murai,∗1,∗2 K. Yoshida,∗1
D. Kameda,∗1 H. Sato,∗1 Y. Sato,∗1 Y. Yanagisawa,∗1 K. Kusaka,∗1 M. Ohtake,∗1 N. Inabe,∗1 and T. Kubo∗1

26

103

24
22

102

20

56Ca

18
10

16
14
12
2.5

2.55

2.6

2.65

2.7

2.75

2.8

2.85

2.9

2.95

3

1

mass-to-charge ratio A/Q

Fig. 1. Particle identification plot of atomic number Z versus mass-to-charge ratio A/Q for projectile fragmentation in the reaction of 70 Zn + Be at an energy of 345
MeV/nucleon.

ment with the EPAX parameterizations. The production cross sections are consistent with EPAX2.15 forZ < 20 and with EPAX3.1a for Z > 20.

Table 1. Experimental conditions.
Center particle
TargetF1 degrader
F5 degrader
Bρ01
Momentum acceptance56

Ca
Be 10 mm
Al 3 mm
Al 5 mm
7.349 Tm
± 3%

The production cross sections were obtained using
the transmission efficiency calculated using LISE++
code3) and production yields. In Figure 2, the redcircles represent the experimental result of RIs produced from the 70 Zn beam. The solid and dashedlines in Fig. 2 represent the production cross sections
calculated with empirical formulae EPAX3.1a4) and
EPAX2.155) , respectively. EPAX3 is proposed as theuniversal empirical formula, and it shows better agreement with experimental data for the most neutron-richfragments than EPAX2 does. Overall, our experimental measurements of cross sections are in good agree∗1∗2

RIKEN Nishina Center
Department of Physics, Rikkyo University- 75 -

Fig. 2. Production cross section for fragments of the 70 Zn
beam. The solid and dashed lines represent EPAX parameterizations, and the red circles represent experimental results.

References
1) T. Kubo et al.: Nucl. Instrum. Meth. Phys. Res. B 204,
97 (2003).
2) N. Fukuda et al.: Nucl. Instrum. Meth. Phys. Res. B
317, 323 (2013).
3) O. B. Tarasov et al.: http://lise.nscl.msu.edu
4) K. Sümmer: Phys. Rev. C 86, 014601 (2012).
5) K. Sümmer and B. Blank: Phys. Rev. C 61, 034607(2000).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-1. Nuclear Physics

On-line test of rotating magnetic ﬁeld system for β-NMR method
Y. Ishibashi,∗1,∗2 D. Nagae,∗1 Y. Abe,∗1,∗2 Y.E. Ichikawa,∗1 K. Sawahata,∗1 A. Ozawa,∗1 and H. Ueno∗2∗1∗2

Institute of Physics, Univ. of Tsukuba
RIKEN Nishina Center- 76 -

is written as Aβ P =Tank circuit (a)Phaseshifter Attenuator
Amp

᳸
F.G.

√
√
(R0 /R) − 1/ (R0 /R) + 1.
Variable
capacitor
Cable
delay

Ferrite core

Tank circuit (b)5)
Magnet pole

Staticmagnetic field5)

β-ray counter
telescope&D)FU\VWDO

Pickupcoil 1

Pickupcoil 2

Staticmagneticfield

Spin polarizedbeam

RF coil

Spin polarizedbeam
Oscilloscope

Fig. 1. Block diagram of the RF system for the rotating
magnetic ﬁeld and a schematic layout of the β-NMR
setup.

−→The d beam was pulsed with beam-on and beamoﬀ periods of 16 s and 22.02 s, respectively. In the
beam-oﬀ period of a cycle, RF was applied for the ﬁrst
10 ms. Subsequently, the β-rays were counted for 22s, and in the last 10 ms of the beam-oﬀ period RF wasapplied again to restore the spin direction. First, wemeasured R0 without RF and then, we measured R
with RF. This cycle was repeated until the required
measurement statistics were attained.
In this experiment, we ﬁrst measured a µ moment
by using β-NMR applied to the linear RF using tankcircuit (a); then, measured it using another one. Figure 2 shows obtained Aβ P values. Next, we attempted
to measure the sign of µ(20 F) by applying a rotating
RF. Analysis of the results is in progress.
0.5
0.4
0.3

AP [%]The β-ray detected nuclear magnetic resonance (βNMR) method1) is an eﬃcient method to measure thenuclear magnetic (µ) moment of unstable nuclei. The
absolute value of µ moments are measured for various nuclei by using β-NMR. However, the sign of µmoments are rarely measured in experiment. In the βNMR method, a linear oscillating magnetic ﬁeld (RF),which can be a superposition of a right- and leftrotating RF, is applied to invert the direction of spinpolarization. Thus, only the absolute value of µ moments is estimated from the applied frequency of thelinear RF. Therefore, to determine the sign of a µ moment, applying a rotating RF is necessary. A rotating
RF system has been under development2,3) to determine the sign of a µ moment by using the β-NMR
method. The rotating magnetic ﬁeld is obtained using two Helmholtz-like coils with axes crossed at rightangles. The experimental apparatus to produce the rotating RF is shown in Fig. 1, and a detailed description
is given in Ref. 2 and 3.
In the present work, the performance of the system
was studied with spin-polarized 20 F (I π = 2+ , T1/2
= 11.163 s, µ(20 F) = +2.09335(9) µN ) nuclei at the
Research Center for Nuclear Physics, Osaka University. A spin-polarized 20 F nucleus was produced in−→
the 19 F( d , p)20 F reaction. In this reaction, the polarization of the beam particles is transferred to each−→nucleus. The d beam was produced using a polarized ion source4) , and accelerated at E/A = 10 MeV
using the AVF cyclotron. The polarized beams were
impinged on a CaF2 crystal (0.5 mmt ) to produce thepolarized 20 F. The crystal was placed at the center ofthe β-NMR apparatus (See Fig. 1.) at room temperature with a static magnetic ﬁeld B0 = 500 mT applied.
The β-rays emitted from 20 F nuclei were detectedwith plastic scintillator telescopes located above andbelow the crystal. The up/down ratio R of the β-ray
counts is written as R0 ≈ a(1+Aβ P )/(1−Aβ P ), wherea denotes a constant factor representing asymmetries
in counter solid angles and eﬃciencies and Aβ and P
denote the β-ray asymmetry parameter and the degreeof spin-polarization, respectively. A rotating RF perpendicular to B0 is applied to 20 F by using the twopairs of coils. If the frequency and direction of the rotating RF correspond to the resonance values, the direction of the spin polarization is inverted (P → −P )by the NMR. Thus, the up/down ratio is changed as
R ≈ a(1 − Aβ P )/(1 + Aβ P ). When the polarization isaltered because of the resonant spin change, a change
appears in the ratio R0 /R. The β-ray asymmetry Aβ P

0.2
0.1
0

Linear RF Field1

Linear RF Field2

Fig. 2. Obtained Aβ P value of 20 F with applied linear RF
ﬁeld.

References
1) K. Sugimoto et al.: J. Phys. Soc. Jpn. 21, 213 (1966)
2) T. Niwa et al.: UTTAC 81, 5 (2012)3) D. Nagae et al.: Hype. Int. 220, 65 (2013)
4) K. Hatanaka et al.: Nucl. Instr. and Meth. 217, 397(1983)

Ⅱ-1. Nuclear Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Probing the critical behavior in the evolution of GDR width at very
low temperatures in A ∼ 100 mass region†
B. Dey,∗1 D. Mondal,∗1 D. Pandit,∗1 S. Mukhopadhyay,∗1 S. Pal,∗1 S. Bhattacharya,∗2 A. De,∗3 K. Banerjee,∗1
N. Dinh Dang,∗4 N. Quang Hung,∗5 and S.R. Banerjee∗1

†
∗1
∗2
∗3
∗4
∗5

Condensed from the article in Phys. Lett. B 731, 92 (2014)
Variable Energy Cyclotron Center, Kolkata
Department of Physics, Barasat Govt. College, Kolkata
Department of Physics, Raniganj Girls’ College, Kolkata
RIKEN Nishina Center
School of Engineering, Tan Tao University- 77 -GDR width (MeV)12

GDR width (MeV)

Although a wealth of data exists on the angular momentum dependence of width of giant dipole resonance(GDR) in different mass regions, the measurement of
the GDR width at low temperatures (T < 1 MeV)
is rather scarce due to the experimental difficulties in
populating the nuclei at low excitation energies. The
present work aims at providing systematic experimental data on the GDR width, specifically, at this very
low temperature region. It is also our endeavor to systematically assess the different theoretical models andunderstand the complete nature of the damping mechanism as a function of T inside the atomic nucleus.
The increase of the GDR width as a function of T
is described reasonably well within the Phonon Damping Model (PDM)1) . The GDR damping mechanism
is caused by coupling of the GDR to noncollective
particle-hole (ph) and particle-particle (pp) [hole-hole(hh)] configurations. The coupling to the various phconfigurations leads to the quantal width (exists evenat T = 0), whereas the thermal width arises owing to
the coupling to pp and hh configurations which appear at T > 0 because of the distortion of the Fermi
surface. Thermal pairing since is also included, sincein finite systems it does not collapse at the temperature of the superfluid-normal phase transition in infinite systems, but decreases monotonically as T increases. The macroscopic Thermal Shape Fluctuation
Model (TSFM)2,3) , on the other hand, is based on
the fact that large-amplitude thermal fluctuations of
the nuclear shape play an important role in describing the increase of the GDR width as a function of T .
The TSFM, however, cannot explain the T dependence
below 1.5 MeV in different mass regions. Recently,
by modifying the phenomenological parameterization(pTSFM)3) , a new fitting formula, called the Critical Temperature included Fluctuation Model (CTFM),
was proposed4) , which gives a good description of the
GDR width behavior for both T and J in the entire
mass region.
In this work, a systematic measurement of the apparent GDR width has been carried out in the unexplored region (T = 0.8 − 1.5 MeV) for 97 Tc using alphainduced fusion reactions. This is the first measurementof the GDR width at finite temperature in A ∼ 100
mass region both above and below the critical point

(a)
10
8

TSFM

6
CTFM
4

(b)

10
8

PDM

6
4
0.0

0.5

1.0

1.5

2.0

2.5

Temperature (MeV)

Fig. 1. (a) GDR width as a function of temperature. Symbols are experimental data. The TSFM calculations
with shell effect (dotted lines) and without it (dashedlines) are shown for J = 0h̄ (lower) and J = 30h̄ (upper). Continuous lines are the CTFM predictions for
J = 10h̄ (lower) and J = 20h̄ (upper). (b) The solidline shows the result of PDM calculations, performed
at J = 0 by using the single-particle energies obtained
within the deformed Woods-Saxon potentials with thedeformation parameter β = 0.134, and including exact
canonical-ensemble thermal pairing gaps for neutronsand protons.

and can be effectively used to verify the existing theoretical models. The experiments were performed at the
Variable Energy Cyclotron Centre (VECC), Kolkata.
A self supporting 1 mg/cm2 thick 93 Nb target was
bombarded with alpha beams produced by the K-130
cyclotron. Four different beam energies of 28, 35, 42
and 50 MeV were used to form the compound nucleus(CN) 97 Tc at the excitation energies of 29.3, 36, 43 and50.4 MeV, respectively. The high energy γ-rays fromthe decay of 97 Tc were detected using the high energy
photon spectrometer LAMBDA.
The data have been compared with the TSFM,
CTFM and PDM. Interestingly, the CTFM and PDM
give the similar results and agree with the data,
whereas the TSFM differs significantly even after incorporating the shell effects (Fig. 1).
References
1) N. Dinh Dang and A. Arima, Phys. Rev. Lett. 80, 4145
(1998), Nucl. Phys. A 636, 427 (1998); N. Dinh Dang,
Phys. Rev. C 85, 2023 (2012); N. Dinh Dang and N.
Quang Hung, Phys. Rev. C 86, 044333 (2012).
2) W. E. Ormand et al., Phys. Rev. Lett. 77 607 (1996).
3) D. Kusnezov et al., Phys. Rev. Lett. 81, 542 (1998).
4) Deepak Pandit et al., Phys. Lett. B 713, 434 (2012).

2. Nuclear Physics (Theory)Ⅱ-2. Nuclear Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Hoyle band and α condensation in 12 C
Y. Funaki∗1
The Hoyle state, the second J π = 0+ state at 7.65
MeV in 12 C, is a typical example of cluster states andhad a long history since it was predicted by F. Hoyle
and subsequently observed by Cook et al. as a key
state in the synthesis of 12 C in stellar evolution. In thelast decade, the aspects of the α condensate, in which
α clusters occupy an identical S-orbit, has attracted
great interest since the so-called Tohsaki-HoriuchiSchuck-Röpke (THSR) wave function1) , which has the
3α condensate character, was shown to be equivalent
to the Hoyle state wave function obtained by solving
the equations of the full 3α resonating group method(RGM) or generator coordinate method (GCM)2) . In
addition to the Hoyle state, the nature of the otherpositive-parity excited states were recently highlighted
by many experiments3–6) .
In this report, we investigate the structures of thepositive parity excited states above the 3α thresholdby using an extended version of the THSR wave function, which includes the 3α condensate and 8 Be + α
asymptotic conﬁgurations, with a treatment of resonances7) . In particular, we focus on the structures of
3–5)
6)
the “Hoyle band” states as well as the 2+
and 4+
2
2
states, which were recently observed above the Hoyle+
state, in addition to the structures of the 0+
3 and 04
states, which were also quite recently identiﬁed in experiment3) .
7

experiment, which gives a support to the rotational
picture. In fact, we found the very strong E2 transi+
tions inside the Hoyle band B(E2; 4+
2 → 22 ) = 591
4
4
+
+
2
2
e fm and B(E2; 22 → 02 ) = 295 e fm .
On the other hand, the J π = 0+ band head in experiment seems to be fragmented into the Hoyle state andthe 0+
3 state, and the calculated levels also have a similar tendency concerning the B(E2) transition from the2+
2 state, the Hoyle state being located slightly below
and the 0+
3 state slightly above the J(J + 1) line. Ac+
cordingly, the transition between the 2+
2 and 03 states++2
is also very strong B(E2; 22 → 03 ) = 104 e fm4 .
This suggests that the Hoyle band, especially inwhat concerns the 0+ band-head state, cannot be considered a simple rotational band. This results fromthe fact that the 3α condensate structure in the Hoyle
state is not the same as the usual 8 Be(0+ ) + α rotation, in which the remaining α cluster orbits outside
the 8 Be core. Namely, in the Hoyle state, the remaining α cluster also orbits inside the 8 Be core, and independent 3α-cluster motion in an identical 0S-orbit
is realized. Consequently, the Hoyle state gains extra binding energy, and hence its energy position isconsidered to be pushed below the J(J + 1) line, as
shown in Fig. 1. The same eﬀect is also argued tooccur in the study of 16 O8,9) , in which the 4α condensate is identiﬁed as a “complete condensate” and the
12C(0+2 ) + α state as a “local condensate”. Because of
the existence of the “complete condensate”, a higher
0+ excited state, which is shown to have a prominent8
Be(0+ ) + α structure7,10) with the remaining α cluster orbiting outside the 8 Be core, appears as a higher
nodal state, the 0+
3 state excited from the Hoyle statewith a very strong monopole transition strength calcu2+
lated to be M (E0; 0+
2 → 03 ) = 35 fm .

(4++))exp.
(4
exp.

6

th. [MeV]
E−E
E−E3th.
3αα [MeV]

5
4(0+4+4 )exp.
exp.

(2++))exp.
(2
exp.

3
+
+

exp.
2 (033 )exp.

References

1+(0+22 )exp.
exp.

1) A. Tohsaki et al. Phys. Rev. Lett. 87, 192501 (2001).
2) Y. Funaki et al. Phys. Rev. C 67, 051306(R) (2003).
3) M. Itoh et al. Nucl. Phys. A 738, 268 (2004); M. Itohet al. Phys. Rev. C 84, 054308 (2011).
4) M. Freer et al. Phys. Rev. C 80, 041303(R) (2009).
5) W. R. Zimmerman et al. Phys. Rev. Lett. 110, 152502(2013).
6) M. Freer et al. Phys. Rev. C 83, 034314 (2011).
7) Y. Funaki arXiv: 1408.5855.
8) S. Ohkubo and Y. Hirabayashi Phys. Lett. B 684, 127(2010).
9) Y. Funaki et al. Prog. Theor. Phys. Supple. 196, 439(2012).
10) C. Kurokawa and K. Katō Phys. Rev. C 71, 021301(2005); Nucl. Phys. A 792, 87 (2007).

0
0

3

66

J(J+1)
J(J+1)

12
12

20
20

+
+
Fig. 1. The observed energy levels for the 0+
3 , 04 , and 22
+ 5)
+ 6)
3)
states in Ref. , and the 22
and 42states are denoted by black circles and black squares, respectively.
The calculated energy levels for the five states are denoted by red diamonds.

In Fig. 1, the calculated energy levels are plotted asa function of J(J + 1), together with the experimental++
data. We can observe that the 0+
2 , 22 , and 42 statesroughly follow a J(J +1) trajectory both in theory and∗1

RIKEN Nishina Center- 79 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Energy and mass-number dependence of hadron-nucleus total
reaction cross sections†
A. Kohama,∗1 K. Iida,∗1,∗2 and K. Oyamatsu∗1,∗3
The size of an atomic nucleus is one of the most fundamental quantities that characterize the bulk properties of nuclei. It is well known for β stable nuclei inthe ground state thanks to systematic measurements ofelectron and proton elastic differential cross sections.
This helps clarify the equation of state of nuclear matter near the saturation point.1)
In this work, we systematically analyze nuclear reaction data that are sensitive to nuclear size, namely,
proton-nucleus total reaction cross sections σR (p + A)
and differential elastic cross sections, using a phenomenological black-sphere (BS) approximation of nuclei that we are developing. In this framework, theradius of the black sphere “a” is found to be a usefullength scale that simultaneously accounts for the observed σR (p+A) and first diffraction peak in the proton
elastic differential cross section. This framework is expected to be applicable to any kind of projectile thatis strongly attenuated in the nucleus. On the basis ofa cross-section formula constructed within this framework (BS cross-section formula)2) as function of thetarget mass number A and the proton incident energy
Tp , we find that a less familiar A1/6 dependence of σR
plays a crucial role in describing the Tp dependence.
In order to illustrate the A dependence of σR , inFig. 1, we compare the values of the BS cross-section
formula with those obtained by using the square-wellpotential of the same radius “a” within the eikonal
approximation for the cases of natu. C and Pb. By noting that a very well scales as A1/3 , we examine thedifference in the A dependence between the two expressions. As a result of expansion in A, the leading
term is proportional to A2/3 , while the subleading termis proportional to A1/3 multiplied by an A dependent
exponential suppression factor in the eikonal approximation, which causes a different Tp dependence fromthe solid curve in each panel of Fig. 1. This difference
results from the A1/6 dependence in σR .
By comparing the solid curves in the upper and lower
panels of Fig. 1, one can see the relatively weaker Tp
dependence for the case of Pb. The cross section itself
grows proportional to ∼ A2/3 , while the Tp -dependent
term is proportional to ∼ A1/6 , leading to O(A−1/2 )corrections to the O(A2/3 ) term. Thus, the relativechange in the cross section by Tp is suppressed. Thisis the reason why the slope toward a lower Tp becomessteeper for the case of C than that of Pb. The lat†
∗1
∗2
∗3

Condensed from the article in arXiv: 1411.7737
RIKEN Nishina Center
Depart. of Natural Science, Kochi University
Depart. of Human Informatics, Aichi Shukutoku University- 80 -

Fig. 1. Comparison of the BS cross-section formula (solid
curve) with the eikonal approximation based on thesquare-well potential (dashed curve) for σR (p + natu. C)(upper) and σR (p +natu./208 Pb) (lower) as a functionof Tp . We adopt both the BS radius at 800 MeV andthe square-well radius as 2.70 fm for carbon and 7.40
fm for lead. The values of σBS (≡ πa2 ), which are represented by squares with crosses, are obtained from themeasured peak angle of the first diffraction maximum of
the proton elastic scattering. They are consistent withthe measured σR (◦3) , ×4) ).

est empirical values of σR 4) apparently support thepresence of the O(A1/6 ) correction term in σR .
A part of this work was already reported in Ref.[5].
References
1) K. Oyamatsu et al.: Prog. Theor. Phys. 109, 631 (2003).
2) K. Iida et al.: J. Phys. Soc. Japan 76, 044201 (2007).
3) R. F. Carlson: At. Data Nucl. Data Tables 63, 93(1996).
4) A. Auce et al.: Phys. Rev. C 71, 064606 (2005).
5) A. Kohama et al.: RIKEN Accel. Prog. 43, 59 (2009).

Ⅱ-2. Nuclear Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Systematic calculation of T = 1 triplets with proton–neutron mixed
energy density functionals
K. Sato,∗1 J. Dobaczewski,∗2,∗3,∗4 T. Nakatsukasa,∗1,∗5 and W. Satu�la∗2,∗4

∗1
∗2
∗3
∗4
∗5

RIKEN Nishina Center
Institute of Theoretical Physics, Faculty of Physics,Universityof Warsaw
Department of Physics, University of Jyväskylä
Helsinki Institute of Physics, University of Helsinki
Center for Computational Sciences, University of Tsukuba- 81 -

formed a systematic calculation of the T = 1 triplets in
A = 4n + 2 nuclei. We calculated the triple energy difference (TED)4) 2E(Tz = 0)−E(Tz = 1)−E(Tz = −1)
with several Skyrme parameter sets. In this model,
while the Tz = ±1 IASs are obtained with the standard Hartree-Fock calculation without p-n mixing, theTz = 0 IAS is calculated using the isocranking modeland is described by a single time-even Slater determinant consisting of p-n mixed single particles.
Figure 1 shows examples of the results of the calculation. We plot the deviation of the calculated TEDs
from the experimental data in the A = 14 − 58 region.
The TEDs in the T = 1 triplets calculated with theSLy4, SIII, and SkM* parameter sets are shown. One
can see a systematic underestimation of the TEDs in
Fig. 1. In this calculation, we used isoscalar EDFs,
which are invariant under rotation in isospin space,plus the Coulomb energy functional. This systematicdeviation may imply that we need to extend functionals further to include isospin breaking terms. We already started performing a calculation including theisospin breaking interaction, which will be reported
elsewhere.
TED(calc.)-TED(exp.) (MeV)

We performed a systematic calculation for T = 1
isobaric analog states (IASs) based on energy density functionals (EDFs) including proton-neutron (p-n)
mixing. Recently, we developed a new model to calculate IASs on the basis of the Skyrme EDFs that include
arbitrary mixing between protons and neutrons1) . In
this framework, single-particle states are generalized assuperpositions of proton and neutron components. In
connection with this extension of single particles, density functionals are also extened to those with mixing
between protons and neutrons2) . In this work, we consider an extension of EDFs including p-n mixing onlyin the particle-hole (p-h) channel, with both the rotational and isospin symmetries conserved. Our ultimate
goal, however, is to develop a consistent symmetryunrestricted EDF approach including p-n mixing bothin the p-h and pairing channels.
We developed a code for the p-n mixing calculation
by extending the code “HFODD,”3) which solves thenuclear Skyrme–Hartree–Fock(–Bogolyubov) problem
by using the Cartesian deformed harmonic-oscillator
basis. In this p-n mixing calculation, we perform
isocranking calculation by adding the isocranking term
�t is the isospin
to the Hamiltonian: ĥ� = ĥ − �λ · ˆ�t. Here, ˆoperator. The isocranking term is analogous to thatused in the standard tilted-axis-cranking calculations
for high-spin states. By adjusting the isocranking frequency �λ, we can control the size and direction of theisospin of the system.
In Ref. 1), we developed an eﬃcient method for determining the isocranking frequency and successfully
applied the isocranking model to the IASs in eveneven A = 40 − 56 and odd-odd A = 14 isobars. Thus,
we demonstrated that the p-n mixed single-reference
EDF approach is capable of quantitatively describing
the isobaric analog excited states. Among the resultsin Ref. 1), that of odd-odd T = 1 IASs is of particular interest (See Fig. 4 in Ref. 1)). We calculated
the energies of the I = 0+ , T = 1 triplet of statesin the A = 14 isobars, 14 C, 14 N, and 14 O by using
the SkM* EDF. We found that there is asymmetry between the energy diﬀerences |E(Tz = 0)− E(Tz = −1)|and |E(Tz = 0) − E(Tz = 1)|, which may be related tocharge asymmetry and independence of the NN interaction. To investigate this point, in this study, we per-

0.4
0.2
0

SLy4
SIII
SkM*

-0.2
-0.4
-0.6
-0.8

10 15 20 25 30 35 40 45 50 55 60
A

Fig. 1. Deviation of the calculated triple energy diﬀerence
from the experimental data5) , TED(calc.)-TED(exp.),
for the T = 1 triplets in A = 14 − 58 nuclei. The TEDs
calculated with SLy4, SIII, and SkM* are plotted.

References
1) K. Sato et al.: Phys. Rev. C 86, 061301(R) (2013).
2) E. Perlińska et al.: Phys. Rev. C 69, 014316 (2004).
3) N. Schunck et al.: Comput. Phys. Commun. 183, 166(2012); J. Dobaczewski et al. (unpublished).
4) W. Satu�la et al.: Acta. Phys. Pol. B 45 167 (2014).
5) National Nuclear Data Center, Brookhaven National
Laboratory, http://www.nndc.bnl.gov/.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Correlated two-neutron emission in decay of unbound nucleus 26 O†
K. Hagino∗1 and H. Sagawa∗2,∗3
We study the two-neutron decay of the unbound 26 O
nucleus with a three-body model assuming an inert 24 O
core and two valence neutrons. In order to describe thedecay properties of the neutron unbound nucleus, wetake into account the couplings to the contiuum byusing the Green’s function technique.
In the experiment of Ref.1) , the 26 O nucleus wasproduced in a single proton-knockout reaction from asecondary 27 F beam. Therefore, we ﬁrst construct the
ground state of 27 F with a three-body model, assuming the 25 F+n+n structure. We then assume a sudden proton removal; that is, the 25 F core changes to24
O keeping the conﬁguration for the n+n subsystemof 26 O to be the same as that in the ground state of27
F. This initial state, Ψi , is then evolved with the
Hamiltonian for the three-body 24 O+n+n system forthe two-neutron decay.
We consider two three-body Hamiltonians, one forthe initial state 25 F+n+n and the other for the ﬁnal
state 24 O+n+n. For both cases, we use the Hamiltonian
H = ĥnC (1) + ĥnC (2) + v(1, 2) +p⃗1 · p⃗2
,
Ac m

(1)

where Ac is the mass number of the core nucleus, m isthe nucleon mass, and ĥnC is the single-particle (s.p.)
Hamiltonian for a valence neutron interacting with thecore. We use a contact interaction between the valence
neutrons. See ref.2) for details of the parameters of Eq.
(1) and the contact interaciton between the neutrons.
With the initial wave function from the three-bodymodel, the decay energy spectrum can be computed
as3)
dP
1
= ℑ⟨Ψi |G(E)|Ψi ⟩,
dE
π

(2)

with G(E) = G0 (E) − G0 (E)v(1 + G0 (E)v)−1 G0 (E),where ℑ denotes the imaginary part. G(E) is the perturbed Green’s function, while G0 (E) is the unperturbed Green’s function given by
G0 (E) =∑ |(j1 j2 )(0+ ) ⟩⟨(j1 j2 )(0+ ) |1,2

e1 + e2 − E − iη,(3)where the sum includes all independent two-particle
states coupled to the total angular momentum J = 0
with positive parity, as described by the three-body
Hamiltonian for 24 O+n + n.
Figure 1 shows the decay energy spectrum obtained
†
∗1
∗2
∗3

Condensed from the article in Phys. Rev. C 89,
014331(2014)
Department of Physics, Tohoku University
RIKEN Nishina Center
Center for Mathematics and Physics, University of Aizu

- 82 -

Fig. 1. (Color online) Decay energy spectrum for the twoneutron emission decay of 26 O. The solid line shows
the result with the full inclusion of the final–stateneutron-neutron (nn) interaction, while the dotted line
shows the result without the final–state nn interaction. The dashed line is obtained by including only+
the (d3/2 d3/2 )(0 ) configurations in the unperturbed
Green’s function of Eq. (3). The theoretical curves
are drawn with a finite width of 0.21 MeV, which isthe same as the experimental energy resolution. The
experimental data are taken from Ref.1) .

with Eq. (2). The solid line shows the correlated spectrum, in which the ﬁnal–state nn interaction is fully
taken into account, while the dotted line shows the result without the ﬁnal–state nn interaction. The lattercorresponds to the term G0 (E) in G(E). Without the
ﬁnal–state nn interaction, the two valence neutrons in
26
O occupy the s.p. resonance state of 1d3/2 at 770
keV, and the peak in the decay energy spectrum appears at twice this energy. When the ﬁnal–state nn interaction is taken into account, the peak is drasticallyshifted towards a lower energy and appears at 0.14
MeV, in good agreement with the experimental data.
The ﬁgure also shows with the dashed line the result+
obtained by including only the (d3/2 d3/2 )(0 ) conﬁgurations in the unperturbed Green’s function of Eq.
(3). This corresponds to the case without the dineutron correlation in the ﬁnal state, as the dineutron correlation is caused by an admixture of several conﬁgurations with diﬀerent parities. The dineutron correlation
shifts the peak position further down, making the peak
appear at an energy close to the threshold, as shownby the solid line.
We discuss the role of neutron-neutron correlation in
the decay probability as well as in the energy and theangular distributions of the emitted neutrons in Ref.2)
References
1) E.Lunderberg et al.,Phys.Rev.Lett.108,142503 (21012).
2) K.Hagino and H.Sagawa, Phys.Rev.C89,014331(2014).
3) H.Esbensen and G.F.Bertsch, Nucl.Phys.A542, 310(1992).

K. Hagino∗1,∗2 and H. Sagawa∗3,∗4
discussthe2+ state of 26 O using a three-body
Ⅱ-2.WeNuclearPhysics(Theory)
24

to, but slightly smaller than,
theAccel.
unperturbed
RIKEN
Prog. Rep. energy,
48 (2015)
model of an O+n+n system with full account of theE = 1.54 MeV, and thus the energy shift from theunperturbed energy is much smaller than the energy
continuum. The decay energy spectrum for a given+
26 †Three-body
model
state
in argued
O that this is a
shift offor thethe 0+2state.
angular momentum
I can be evaluatedas calculation
We have
typicalspectrum
wellunderstoodbythesingle-j model∑dPI(I) (I) 2
∗1,∗2
∗3,∗4
with
the
pairing
residualinteraction.
Manyshell model=|Ψk |Φref | δ(E − Ek ), K. Hagino (1) and H. SagawadE
3)
calculations
such
as
the
ab
initio
and
USDA
and
k
4)
USDB
calculations
have
predicted
theexcitation
enWe discuss
the 2+ state of 26 O using a three-bodyto, but slightly
smaller 26
than, the unperturbed energy,(I)+
where Ψk 24
is a solution of the three-body model
ergy
of
the
2
state
in
O
in
the
oppositetrend,
i.e.,
model of an O+n+n system with full account of theE = 1.54 MeV, and thus the energy shift from the
Hamiltonian with angular momentum I and energy
they
have predicted
a higherenergy than
than thethe energy
unperunperturbed
energy ismuch smaller
continuum.(I) The decay energy spectrum for a given+
turbedenergy.
Theenergy
of
the
2
E
,
and
Φ
is
the
wave
functionforareference
state
state
needs
k
ref
shift for the 0+ state. We have argued
angularmomentumI can be evaluated asthat thistoisbea
5)with the same angular momentum. For a reference
urgently
conﬁrmed
experimentallyinorder
to clarify
typical spectrum well understood by the single-jmodel
27∑ the(I)dPIwe use
state
uncorrelated
state
of
the
validityofnuclearmodelsandeﬀectiveinteractions
F
with
the
(I) 2
with
the
pairing
residualinteraction.
Many
shell
model
=
|Ψ |Φref |δ(E − Ek ),(1)
innuclei on andbeyondtheneutronneutron](IM )  conﬁguration,
which isdE |[1d3/2 ⊗k 1d3/23) drip-line.
calculations
such
as
the
ab
initio
and
USDA
and
k
dominant in the ground state of 27 F.
USDB4) calculations have predicted the excitation enReferences +WithΨa(I)contacteﬀectsonwhereis a interaction,
solution of thethecontinuum
three-bodymodel
ergy of the 2 state in 26 O in the opposite trend, i.e.,k1) K.Hagino and H.Sagawa, Phys.Rev.C89,014331(2014).
the
decay
energyspectrum
can
be
taken
into
account
Hamiltonian with angular momentum I and energy
they
have predicted
higher energy thanthe unper2) E.Lunderberg
et al.,aPhys.Rev.Lett.108,
142503(21012).
(I)
inGreen’s
Noticethat Eq.state(1)+
turbedenergy.
Theenergyofthe2
Ekterms, and Φofreftheis thewavefunction.
function for
a reference
state
needs
3) C.Caesar et al., Phys. Rev. C88, 034313 (2013). to becanexpressed
aswithbethesame angularmomentum. For a reference
urgently conﬁrmed experimentally5) in order to clarify

4) B.A.Brown and W.A.Richter, Phys.Rev.C74,034315(2006).

-1

dP/dE (MeV )

-1

-1

dP/dE
dP/dE
(MeV
(MeV
) )

-1

dP/dE (MeV )state
uncorrelated
state1of 27 F with
theY.Kondo
validity of
nuclearmodels privateand eﬀective
interactions
the
5)
and
T.Nakamura,communications.
dPIwe use1the∑
(I)
(I)
(I)
(I)
(IM
)
=|[1d
− ⊗ 1dΦref] |Ψk  conﬁguration,Ψwhich|Φrefis, in nuclei on and beyond the neutron drip-line.
kneutron
3/2
3/2
dE
π
Ek − E − iηkdominant in the groundstate of 27 F.
1(I)(I)continuum eﬀects on(I)
With ≡a contactthe− Φinteraction,(E)|Φ(2) References
Uncorrelated
ref |Gref ,π1) K.Hagino andthe decay energy
spectrum can be taken into account
1 H.Sagawa, Phys.Rev.C89,014331(2014).
I=02) E.Lunderberg et al., Phys.Rev.Lett.108,
142503(21012).
I=2
in
terms ofdenotes
the Green’s
function. Noticethat ηEq.
where
the imaginary
part andis (1)an3) C.Caesar 0.8
et al., Phys. Rev. C88, 034313 (2013).
(I)
can
be
expressed
asinﬁnitesimal number and G (E) is the correlated4) B.A.Brown and W.A.Richter, Phys.Rev.C74,034315(2006).
0.6
Greens’scorrelated Greens’s
function5) Y.Kondo and T.Nakamura, private communications.
dPI function.
1 ∑ The
1
(I)
(I)
(I)
(I)
− 
Φusing unperturbedΨGreen’s|Φref ,will be =constructedref |Ψkthe
0.4dE
πEk − E − iη kkfunction.
0.2(I)
The upper1panel(I)of Fig.
1 shows
the decay energy≡ −26 Φref |G(I) (E)|Φref ,(2)
Uncorrelated
spectrum of π O for I = 0 (dashed line) and I=2 (solid01I=01line).
set η andin Eq.
to2 x (I=2)
0.9 x (I=0) I+=0.1
where For presentation
denotes the purposes,
imaginarywe1)part
η (2)
is an
0.8
be
a
ﬁnite
value,
i.e.,
η
=
0.21
MeV
.
For
comparison,
I=0
only
(I)
inﬁnitesimal number and G (E) is the correlated
0.8
we also show
the spectrum
for the Greens’s
uncorrelatedcase
0.6
Greens’sfunction.
The correlated
functionwith bea dottedline, which
givessame spectrum
both
0.6 +
will
constructed
using
thetheunperturbed
Green’sThree-bodymodel calculationof thestate in 26 O†
0.4 2
for
I
=
0
and
I
=
2.
For
the
uncorrelated
case,
the
function.
0.4
spectrumhas panela peakofatFig.
E =11.54
MeV,
twice
0.2
The uppershows
thewhichdecayisenergy
∗1,∗2
∗3,∗4
and
H.
SagawaK.
Haginothesingle-particle
energy,
0.77
With
0.2
spectrumof 26 O forresonanceI = 0 (dashedline)
andMeV.
I=2 (solid0
thepairing
interaction
betweenthevalenceneutrons,
1line). For presentation
purposes,
we
set
η
in
Eq.
(2)
to
0.9 x (I=0) + 0.1 x (I=2)
26 lower energies. The
0 smaller than,theenergyshiftstowards
discussthei.e.,2+ ηstateof MeVO 1)
using
acomparison,
three-bodyto, but slightly0
1 I=0 only
2the unperturbed
3
4 energy,
beWea peakﬁnite
value,
=
0.21
.
For
24
0.8
energyshift∆Eislarger
in
I
=
0
than
in
I
=
2,
i.e.
,
E
(MeV)
model
of
an
E
=
1.54
MeV,
and
thus
the
energyshift
from theO+n+nsystemwithfull
accountofthewe also show the spectrum for the uncorrelated case
the
peak
in
the
spectrumappears
at
E
=
0.148
MeV
unperturbed
energyismuchsmallerthantheenergycontinuum.
The
decay
energyspectrum
for
a
given
with a dotted line, which gives the same spectrum both
0.6+
(∆E
=
−1.392
MeV)
for
I
=
0
and
at
E
=
1.354
MeV
Fig.
1.
(upperpanel)
The
decay
energyspectrumfor isthe
shift
for
the
0
angularmomentumI
canbeevaluatedasstate.
We
have
arguedthat
thisafor I = 0 and I = 2. For the uncorrelated case, the26(∆E=−0.186
MeV)
for
I
=
2.
O.
The
dashedandtwo-neutron
emission
decay
of
0.4
typicalspectrum
wellunderstoodbythesingle-jmodel
spectrumat
E = 1.54 MeV, which is twice∑ a peakdPI havehas(I) that(I) 2 2+ state appears at apsolid
represent
theinteraction.
0+ and 2+ states,
withthelines
pairing
residual
Many respectively.
shell model= shown|Ψk resonance|Φref |theδ(E− Ek ),0.77 MeV. With
(1)
theWe
single-particle
energy,0.2+
dE
3)
proximately
E
=
1.35
MeV.
This
2
energyiscloseThedotted
line
shows
the
uncorrelated
spectrumobcalculations
such
as
the
ab
initio
and
USDA
and
k
the pairing interaction between the valence neutrons,4) by ignoring the interaction between the valencetainedUSDB
calculations
have
predicted
theexcitationen†0
the Condensedpeak(I)
energyfromshifts
the towards
article inlower
Phys.energies.
Rev. C The
90,
2decay
3
4
+0
where
Ψ
is aissolution
three-bodyenergyspectrumobergyneutrons.
of the 2(lower
statepanel)in1 26 TheO
the opposite
trend,i.e.,k027303(2014)
energyshift∆Elarger in of
I =the0 thanin I = 2,model
i.e. ,
E in
(MeV)
∗1
Hamiltonian
angularmomentum
Departmentwithof Physics,
TohokuUniversity I and energy
tainedbysuperposing
the
I
=
0
and
I
=
2
components.
they
have
predicted
ahigherenergythantheunperthepeak inappears at E = 0.148 MeV∗2(I)the spectrum
Electron
Photon Science,
Tohoku UniThe energy.
dashed line
the decayenergyspectrumturbedTheisenergyof the2+ state
Ek ,ResearchandΦrefCenter
is MeV)theforwave
functionneedsforto thebe(∆E=−1.392forI= 0 andfor
ataEreference= 1.354 state
MeV
Fig. 1. (upper
panel)The decayenergyspectrumfortheversity
5)
pure
I
=
0
conﬁguration.
Theexperimental
data,
norwiththesame
angularmomentum.
Forareferenceurgently
conﬁrmed
experimentally
in
order
to
clarify
26∗3(∆ERIKEN= −0.186
MeV)
for I = 2.
Nishina
Centerandtwo-neutron emission decay of O. The dashed2)
27∗4 Center.
to theunit area,
areand
taken
state
use
the uncorrelatedofappears
the malized
validity
nuclearmodels
F of
with
the
+ from Ref.
for shown
Mathematics
andUniversity
Aizu
We we
have
that (IMthe)Physics,
2+ statestate
at ap2eﬀective
states, interactions
respectively.
solidlinesofrepresent
the 0+ andin nuclei
on andbeyonddrip-line.
neutron|[1d3/2⊗ 1d]
 Thisconﬁguration,is
3/2MeV.
proximately
E =1.35
2+ energywhich
is close
The dottedlineshows thethe neutron
uncorrelated
spectrum obdominant in the ground state of 27 F.
tained by ignoring the interaction between the valence†
Condensed
frominteraction,
the articletheincontinuum
Phys. Rev.
C 90,
ReferencesWith
a contacteﬀectsonneutrons. (lower panel) The decay energy spectrum ob027303(2014)
1) K.Hagino and H.Sagawa, Phys.Rev.C89,014331(2014).
thedecay energy
spectrum
can
be
taken
into
account∗1 Departmentof Physics, Tohoku University
tained by superposing the I = 0 and I = 2 components.
2) E.Lunderberg et al., Phys.Rev.Lett.108, 142503(21012).
∗2 terms
inof Center
the Green’s
function.
that
Eq. Uni(1)Research
for Electron
PhotonNotice
Science,TohokuThe dashedlinePhys.
is theRev.
decay
energyspectrum3) C.Caesar
et al.,
C88,
034313(2013).for the
canversity
be expressed as
pure I = 0 conﬁguration. The experimental data, nor∗3∗4

RIKEN Nishina Center∑ (I)and(I)Centerfor 1
Mathematics
Physics, Universityof (I)
Aizu (I)
dP
1
I
= − 
Ψk |Φref ,Φref |Ψk dEπ
Ek − E − iη4) B.A.Brown and W.A.Richter, Phys.Rev.C74,034315(2006).
malized toandtheT.Nakamura,unit area, areprivate
taken communications.
from Ref.2) .
5) Y.Kondok(2)- 83 -1

where  denotes the imaginary part and η is an
inﬁnitesimal number and G(I) (E) is the correlated

1(MeV )

1(I)(I)≡ − Φref |G(I) (E)|Φref ,
π

0.8
0.6

Uncorrelated
I=0
I=2RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Proton-neutron pairing vibrations in 40 Ca: Precursory soft mode of
the isoscalar spin-triplet pairing condensation†
K. Yoshida∗1†∗1Condensed from the article in Phys. Rev. C 90, 031303(R)(2014)
Graduate School of Science and Technology, Niigata University- 84 -80
-1)" $&$!%$%&$!&
pair-transfer
strength (MeVThe pairing correlation plays a central role in lowenergy nuclear phenomena. The correlation is sostrong that the ﬂuctuations of the pairing gap aroundits zero equilibrium value develop in nuclei near theclosed shell, and the systems get deformed eventuallyin gauge space when more nucleons are added. The collective pairing vibration emerging in the closed-shell
nuclei is thus associated with the occurrence of thepairing condensation.
It is in the isovector and spin-singlet (T = 1, S = 0)channel that the pairing correlation has been extensively studied. With the advent of the radioactiveisotope beam technology, heavy proton-rich nuclei
along the N = Z line have received considerable attention. The isoscalar and spin-triplet (T = 0, S = 1)
pairing correlation is expected to be visible in N ∼ Z
nuclei because the shell structures around the Fermi
levels of both neutrons and protons are similar to eachother and the spatial overlap between the neutron andproton single-particle wave functions would be large toform a proton-neutron (pn) Cooper pair1) . Because of
the strongly attractive pn interaction in the 3 S1 channel, the possible T = 0 pairing condensate has been
discussed theoretically in heavy N ∼ Z nuclei2–4) .
I investigate the possibility of a collective T = 0 pnpairing vibrational mode in the “normal” phase where
the T = 0 pairing gaps are zero. The pn pair excitations are described microscopically based on the nuclear energy-density functional (EDF) method. Moreprecisely, the pn-pairing vibrational modes are obtained out of the solutions of the pn particle-particle
random-phase approximation (ppRPA) equation, andare described as elementary modes of excitation generated by two-body interactions acting between a proton
and a neutron. Then, I show that the strongly collective T = 0 pn-pairing vibrational mode emerges when
the interaction is switched on.
Figure 1 shows the strength distributions for themonopole (L = 0) pn-pair-addition and removal trans†
fer |⟨Z ± 1, N ± 1; λ|P̂T,S(P̂T,S )|Z, N ⟩|2 as functions of
the RPA frequency ωλ in 40 Ca. In the present calculation, the SGII interaction is used for the particlehole (ph) channel. For the pp channel, the densitydependent contact interactions are employed. The
pairing strength in the T = 1 channel is ﬁxed as(T =1)V0= −390 MeV fm3 . The pairing strength in(T =0)(T =1)
the T = 0 channel is given as V0= f × V0
.

f=0

f=1.0

f=1.3

f=1.7

f=2.0



60

40


(a)


42Sc

 15
1+
10


(b)


38

K

1+

5


20

0

8


(c)

42
Sc


6

0+


4

0
4

3
2
1


2


0

0

20


2

4


38
K


(d)

+

0

'!"
unp.

RPA

0
8 0
1
6
2
$#'!(
RPA frequency (MeV)

3

4

Fig. 1. Monopole pn pair-addition strengths of 40 Ca →42
Sc and pair-removal strengths of 40 Ca → 38 K in theπ
J = 1+ , T = 0 [(a), (b)] and J π = 0+ , T = 1 [(c),(d)] states smeared with a width of 0.1 MeV. For the(J, T ) = (1, 0) channel, the strengths obtained with factors f = 0, 1.0, 1.3, 1.7, and 2.0 are shown. For the(J, T ) = (0, 1) channel, the unperturbed single-particle
transition strengths are also shown by a dotted line.

Factor f is changed to see the eﬀect of the interactionin the T = 0 channel.
It is clearly visible that the RPA frequency of the
T = 0 pn-pairing vibrational mode becomes lower on
increasing the pairing strength f . The pairing collectivity generated is sensitive to the shell structure aswell as to the interactions. The critical strength isfound to be fc = 2.04. A rapid lowering of the RPA frequency seen here indicates the occurrence of true vacuum giving the T = 0 pairing gaps ∆ ≡ ⟨P̂T =0,S=1 ⟩ ̸=
0 in the limit of the strong pairing interaction f > fc .
Another direct measure of the collectivity is the pntransfer strength. One can also see an exponential enhancement in the transition strengths when approaching the critical strength fc . Therefore the 1+ state in38
K and 42 Sc can be considered as a precursory softmode of the T = 0, S = 1 pairing condensation.
References
1) A. L. Goodman: Phys. Rev. C 58, R3051 (1998).
2) W. Satula and R. Wyss: Phys. Lett. B 393, 1 (1997).
3) A. L. Goodman: Phys. Rev. C 60, 014311 (1999).
4) G. F. Bertsch and Y. Luo: Phys. Rev. C 81, 064320(2010).

Ⅱ-2. Nuclear Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Study of low-frequency negative-parity vibrational excitations ofsuperdeformed rotational band in 40 Ca using cranked Skyrme-RPA
calculations
M. Yamagami ∗1 and K. Matsuyanagi∗2
An atomic nucleus is a unique quantum system. A
nucleus exists in various modes with diverse shapes andcollective motions by adding only a small percentage ofthe total binding energy. The diversity also increases
with additional isospin and angular momentum.
40
Ca is a representative nucleus: the ground state isspherical with a spherical magic number N = Z = 20;
however a superdeformed (SD) band built on the excited 0+ state at 5.2 MeV was found.1) The large octupole collectivity can be expected in the SD state associated with the SD shell structure that consists of approximately an equal number of positive- and negativeparity levels.
The description of diverse nuclear phenomena
through a single theoretical framework is a challenging
subject. Toward this direction, we have developed theﬁrst computer code of the cranked random phase approximation with Skyrme density functional (cranked
Skyrme-RPA). Using this code, once the Skyrme density functional is ﬁxed, we can calculate consistently
the ground state as well as the rotational and vibrational excitations in nuclei across the nuclear chart.
We adopt the single-particle Hamiltonian with thetriaxially deformed potential that uniformly rotates
about the x-axis with a rotational frequency ωrot ;h′ = h − ωrot jx . The Skyrme SLy4 interaction is employed for h. Two discrete symmetries, the parity androtation about the x-axis at the angle π, are imposedon the single-particle wave functions. The wave functions are represented through Fourier-series expansion
in order to eﬀectively treat the conﬁgurations involving
unbound single-particle states.
We solve the RPA equation in the matrix form witha residual interaction derived from the Skyrme force
through the Landau-Migdal approximation. The oc(ξ,ζ)
tupole transition operators O3K can be classiﬁed by
the z-component K of its angular momentum and thex (z) - signature ξ (ζ) = ±1 representing the symmetry of rotation about the x (z) - axis. The Coriolis
coupling mixes the diﬀerent K and ζ modes. The excitations can be classiﬁed into two types by ξ.
We study the low-frequency negative-parity vibrational excitations of the SD rotational band in 40 Ca.
The upper part of Fig. 1 shows the six vibrational
states with ξ = −1 for vibrational energy Evib < 5
MeV. The isoscalar octupole transition strength B(IS :O3 ) changes as a function of ωrot , and the maximum
value for each vibrational state exceeds 50 Weisskopf
units (W.u.) within the region from ωrot = 0 to 1.6
MeV/ℏ.
The vibrational energy of the ﬁrst excitation decreases as a function of ωrot . The B(IS : O3 ) value
is 66.5 W.u. at ωrot = 0.4 MeV/ℏ and then decreases
slowly. This ωrot dependence is associated with therotational alignment of [440]1/2 particle states: Thiseﬀect reduces the SD shell gap at N (Z) = 20 by 42.4
(40.4) percent while ωrot changes from 0 to 1.5 MeV/ℏ.
The B(IS : O3 ) value is dominated by the ζ = +1
(ζ=+1)(−1,+1)component B(IS : O3
) consisting of O31
and(−1,+1)
O33
operators.
It is quite interesting to investigate what will happen
if ωrot is increased further; however we could not obtain reliable RPA solutions. A better method for eliminating the spurious center of mass component may berequired. Nevertheless, it seems reasonable to assume
that the above discussion will continue: the vibrationalenergy will decrease further and cross the yrast line.
This may indicate an instability of the SD shape, leading to a transition to a non-axial reﬂection-asymmetricshape.

∗1

References∗2

Department of Computer Science and Engineering, University of Aizu
RIKEN Nishina Center- 85 -

Fig. 1.
(Upper) The vibrational energies of negativeparity excitations with ξ = −1 of the SD state in 40 Ca
are shown as a function of ωrot . (Lower) The B(IS : O3 )and B(IS : O3(ζ=+1) ) of the lowest vibrational excitation.

1) E. Ideguchi et al.: Prog. Theor. Phys. Suppl. 196, 427(2012).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Self-consistent Hartree-Fock and RPA Green’s function method formonopole response of neutron-rich Ni isotopes†
I. Hamamoto∗1,∗2 and H. Sagawa∗1,∗3
120

n

1
= Im T r(Q† (⃗r) GRP A (⃗r; r⃗′ ; E) Q(r⃗′ ))
π

(1)
.

(2)

for isoscalar monopole strength. The calculated results are shown in Fig. 1. Note that the widths of
all responses are due to the coupling to the continuum without any smearing factor. It is concluded thatsharp monopole peaks with width on the order of 1
MeV can hardly be expected for 68 Ni in the low energy region below 20 MeV. Instead, a broad shoulderof monopole strength consisting of neutron excitations
to non-resonant one-particle states (called thresholdstrength) with relatively low angular momenta (ℓ, j)
is obtained in the continuum energy region above theparticle threshold, which is considerably lower thanthat of the isoscalar giant monopole resonance. In themonopole excitations of 68 Ni there are no unperturbed
particle-hole states below 20 MeV, in which the particle is placed in either a bound or a resonant state. It isemphasized that in the theoretical estimation a proper
treatment of the continuum is extremely important.
†
∗1
∗2
∗3

unperturbed
RPA

80

4

STRENGTH (fm /MeV)(a)+

Ni IS 0 SLy4

60
40
20
0

0

5

10

15

20
Ex(MeV)

25

30

35

40

10
68

−1

8

4

Ni SLy4
Monopole

1f7/2
7/2

−1

2p3/2
3/2

(b)

−1
5/2
5/2

1f

−1

2p1/2
1/2

6

4

2

where Q expresses one-body operators
1 ∑ 2
Qλ=0, τ =0 = √
ri
4π i

68

100

STRENGTH (fm /MeV)

We discuss low-energy monopole strength of Ni isotopes using the self-consistent Hartree-Fock calculationand the RPA Green’s function method with Skyrmeinteractions. This study is strongly motivated by arecent observation of monopole strength by inelasticalpha scattering at 50A MeV on the unstable nucleus
68Ni.1) The observation of soft monopole mode is reported at 12.9 ± 1.0 MeV, in addition to the isoscalar
giant monopole resonance (ISGMR), for which the centroid is placed at 21.1 ± 1.9 MeV. To study the properties of low-energy monopole strength, the continuum
eﬀect must be properly taken into account in the theoretical calculations. Therefore, we perform the selfconsistent HF+RPA calculations with the Skyrme interactions in coordinate system. The strength distributions S(E) are obtained from the imaginary part of
the RPA Green function, GRP A , as∑|< n | Q | 0 >|2 δ(E − En )S(E) =

Condensed from the article in Phys. Rev. C 90,
031302(R)(2014)
RIKEN Nishina Center
Division of Mathematical Physics, Lund Institute of Technology at the University of Lund
Center for Mathematics and Physics, University of Aizu

- 86 -

0

0

5

10

15

20
25
Ex (MeV)

30

35

40

Fig. 1. (Color online) Monopole strength function (1) of68
Ni . (a) Unperturbed monopole strength and isoscalarmonopole RPA strength. The RPA strength denoted by
the solid curve includes all strengths due to the coupling
between bound and unbound states in RPA. In the unperturbed response, the p-h strengths, in which bothparticle and hole orbits are bound, are not included.
The energies of those unperturbed p-h excitations are
the 1d5/2 → 2d5/2 excitation at 27.60 MeV for neutrons and the excitations of 1p3/2 → 2p3/2 at 27.58
MeV and 1p1/2 → 2p1/2 at 27.46 MeV for protons. In
addition, the proton excitation at 27.3 MeV from thebound 1d5/2 orbit to the one-particle resonant 2d5/2
orbit has such a narrow width that the strength is notplotted. The narrow peaks at 24.1 and 24.7 MeV in theunperturbed strength curve are the proton 2s1/2 → s1/2
and 1d3/2 → 2d3/2 excitations, respectively. (b) Unperturbed neutron threshold strengths, which contribute to
the total unperturbed strength below the energy of ISGMR in Fig. 1a, are shown for respective occupied holeorbits.

References
1) M.Vandebrouck et al., Phys.Rev.Lett. 113,032504(2014).

Ⅱ-2. Nuclear Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Origin of fusion hindrance in heavy systems
K. Washiyama∗1∗1

RIKEN Nishina Center- 87 -

100
100

Mo +
+X
X
Mo

10
10

Energy [MeV]In fusion reactions in heavy systems whose charge
product ZP ZT is larger than 1600, it has been observed1) that the formation of a compound nucleus isstrongly hindered around the Coulomb barrier energy,
compared with ZP ZT < 1600 systems. In such heavy
systems, an additional energy is needed to achieve
fusion, which is called the extra-push energy.2) The
most probable reason behind the fusion hindrance phenomenon is the occurrence of the quasi-fission process,which involves reseparation without the formation of acompound nucleus after two nuclei touch each other, inheavy systems. A macroscopic fluctuation–dissipation
model using a Langevin equation has been developed3)
to analyze quasi-fission and fusion dynamics especiallyin the synthesis of superheavy elements. Recently,
the quasi-fission process was analyzed using the microscopic time-dependent Hartree-Fock (TDHF) model. 4)
The aim of this study is to analyze in detail theorigin of fusion hindrance in heavy systems by using
the microscopic TDHF model. To this end, we employ
our method5) to extract nucleus–nucleus potential andone-body energy dissipation from the relative motionof colliding nuclei to internal degrees of freedom in theentrance channel of fusion reactions from TDHF evolutions. We reported in Ref.6) that the nucleus–nucleus
potential extracted from TDHF in the 96 Zr + 124 Sn
system monotonically increases as the relative distancedecreases, and that the potential shows no ordinary
barrier. In this report, we present results of our systematic study for fusion in heavy systems and discussa possible origin of fusion hindrance.
First, we perform systematic calculations for estimating the extra-push energy by TDHF for several
heavy systems. We define the extra-push energy using TDHF as the difference between the fusion threshold energy and the potential barrier obtained from thefrozen density approximation, Eextra = Ethres − VFD .
The frozen density potential is estimated while keeping the projectile and target densities frozen to theirrespective ground-state densities. We confirm that theobtained extra-push energies agree well with those deduced from experimental observations. Then, we extract the nucleus–nucleus potential V (R) and friction
coefficient γ(R) as a function of the relative distance
between two nuclei R for those systems. We find thatthe property of the extracted potentials is similar tothat in the 96 Zr + 124 Sn system,6) i.e., monotonic increase and no barrier structure in the potential. Finally, we analyze the fusion hindrance in heavy systems. We extract V (R) and γ(R) at the fusion threshold energy. We stop the extraction at Rmin where the

96
96

Zr +
+X
X
Zr

�V
∆V
Ediss
E
diss

88
66
44
22
00

92
92

100
104
110
124
132
136
Mo 100
Mo 104
Ru 110
Pd 124
Sn 132
Sn 136
Xe
Mo
Mo
Ru
Pd
Sn
Sn
Xe

Fig. 1. Increase in potential ∆V (red circle) and accumulated dissipation energy Ediss (blue diamond) for the100
Mo + 92,100 Mo, 104 Ru, 110 Pd and 96 Zr + 124,132 Sn,
136
Xe systems.

remaining kinetic energy reduces as much as possible
in the TDHF simulations. At Rmin , we can identify
the extra-push energy as a sum of the remaining kinetic energy, accumulated dissipation energy estimatedfrom γ(R)5) , and increase in potential due to the frozen
density barrier, denoted by ∆V = V (Rmin ) − VFD . In
Fig. 1, the increase in potential ∆V and dissipated energy Ediss are plotted for the 100 Mo + 92,100 Mo, 104 Ru,
110
Pd (left panel) and 96 Zr + 124,132 Sn, 136 Xe (rightpanel) systems. It is clear that the contribution fromthe increase in potential to the extra-push energy islarger than that from the dissipated energy. From thisfinding, we conclude that the dynamical increase inpotential energy is the main contribution to the extrapush energy.
References
1) C.-C. Sahm et al.: Nucl. Phys. A 441, 316 (1985).
2) W. J. Swiatecki: Nucl. Phys. A 376, 275 (1982).
3) Y. Aritomo, K. Hagino, K. Nishio, and S. Chiba: Phys.
Rev. C 85, 044614 (2012).
4) C. Simenel: Eur. Phys. J. A 48, 152 (2012); L. Guo and
T. Nakatsukasa: EPJ Web Conf. 38, 09003 (2012); V.
E. Oberacker, A. S. Umar, and C. Simenel, Phys. Rev.
C 90, 054605 (2014).
5) K. Washiyama and D. Lacroix: Phys. Rev. C 78, 024610(2008); K. Washiyama, D. Lacroix and S. Ayik: Phys.
Rev. C 79, 024609 (2009).
6) K. Washiyama: RIKEN Accel. Prog. Rep. 47, 67(2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Pairing effect in thermal shape fluctuation model on the width ofgiant dipole resonance†
A.K. Rhine Kumar,∗1 P. Arumugam,∗1 and N. Dinh Dang∗2
The study of nuclear properties at high temperature,spin and isospin has gained much of interest in recent
times. Apart from these extremes, there are still some
unexplored regimes of hot nuclei. The properties of nuclei at very low temperatures and the phase transitions
associated with that belong to such area where conclusive experimental results are scarce. At such low temperatures, the shell (quantal) and pairing effects arequite active though being modified by thermal effects.
In hot nuclei, thermal fluctuations are expected to belarge since the nucleus is a tiny finite system. Thermal shape fluctuations and fluctuations in the pairing
field are the dominating fluctuations and have been so
far studied separately within different models. Bothof these fluctuations are expected to be present at low
temperatures. However, the interplay between themhas not been investigated so far. The present work addresses this subject and we study the influence of thisinterplay on the experimental observables, namely thewidth of giant dipole resonance (GDR). The thermal
shape fluctuation model (TSFM), which is often usedby experimentalists, describes the increase of the GDR
width with temperature by averaging the GDR crosssection over all the quadrupole shapes. However thismodel is known to largely overestimate the GDR widthin open-shell nuclei at low temperatures. The successof a proper pairing approach1,2) suggests the necessityof including pairing correlations to cure this shortcoming of the TSFM. This is done in the present work.
We employ the thermal shape fluctuation model
built on Nilsson-Strutinsky calculations3) with amacroscopic approach to GDR and examine the inclusion of the fluctuations in the pairing field. The nuclear shapes are related to the GDR observables usinga model comprising an anisotropic harmonic oscillator potential with separable dipole-dipole interaction.
In this formalism the GDR Hamiltonian can be written as H = Hosc + η D† D + χ P † P , where Hosc
stands for the anisotropic harmonic oscillator hamiltonian, the parameter η characterizes the isovector component of the neutron and proton average field and χ
denotes the strength of the pairing interaction. The
pairing interaction changes the oscillator frequencies[ωνosc (ν = x, y, z)] resulting in the new set of frequen2+N ∆Ncies ων = ωνosc − χω P , where ω P = Z∆PZ+N
with χ having the units of MeV−1 .
†∗1∗2

Alternatively,

Condensed from the article in Phys. Rev. C. 90, 044308(2014)
Department of Physics, Indian Institute of Technology Roorkee, Uttarakhand
RIKEN Nishina Center- 88 -

Fig. 1. (Color online) GDR width for 97 Tc, calculated
within the liquid drop model (LDM), without pairing,
including BCS pairing and pairing fluctuations, as afunction of temperature in comparison with experimental data2) .

the role of pairing is to renormalize the dipole-dipole√
interaction strength such that, η = η0 − χ0 T ω P ,with χ0 having the units of MeV−5/2 . The effective
GDR cross-sections is calculated by averaging all the
cross-sections obtained from thermal fluctuations ofquadrupole shapes by using the formula for the expectation value of an observable O as �O�β,γ,∆P ,∆N =OW (T, β, γ, ∆P , ∆N )D[α]/ W (T, β, γ, ∆P , ∆N )D[α]with W (T, β, γ, ∆P , ∆N ) = exp[−F (T ; β, γ, ∆P , ∆N )/T ],D[α] = β 4 | sin 3γ| dβ dγ d∆P d∆N . The total free energy (FT OT ) at a fixed deformation is
calculated using the expression FT OT = ELDM + p,n δF . The
liquid-drop energy (ELDM ) is calculated by summingup the Coulomb and surface energies corresponding toa triaxially deformed shape defined by the deformation parameters β and γ. The shell correction (δF )is obtained with exact temperature dependence using
the single-particle energies given by the triaxial Nilsson
model.
The results of our calculations for 97 Tc, 120 Sn and208
Pb demonstrate that the TSFM can be quite successful if the shell effects (with explicit temperaturedependence) and the pairing ones are properly incorporated in the free energy (See Fig. 1).
References
1) N. Dinh Dang, A. Arima, Phys. Rev C 68, 044303(2003); N. Dinh Dang, N. Quang Hung, Phys. Rev C
86, 044333 (2012).
2) B. Dey, et al, Phys. Lett. B 731, 92 (2014).
3) P. Arumugam, G. Shanmugam, S. K. Patra, Phys. Rev.
C 69, 054313 (2004).

Ⅱ-2. Nuclear Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Shell-model study of Gamow-Teller transition from 100 Sn
M. Honma,∗1 T. Otsuka,∗2,∗3,∗4 T. Mizusaki,5 Y. Utsuno,∗6 N. Shimizu,∗3 and M. Hjorth-Jensen∗4,∗7

∗1
∗2
∗3
∗4
∗5
∗6
∗7

Center for Mathematics and Physics, University of Aizu
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
National Superconducting Cyclotron Laboratory, Michigan
State University
Institute of Natural Sciences, Senshu University
Advanced Science Research Center, Japan Atomic Energy
AgencyDepartment of Physics and Center of Mathematics for Applications, University of Oslo

- 89 -

tion of a large part (69%) of the GT strengths on thelowest 1+ state. In the present calculation, the GT
decay goes mainly into the lowest three states, andthe 1+
3 state carries the largest strength as shown in
Fig.1 (B(GT)=2.8 including the standard quenching
factor of 0.74). Further analysis is desired for clarifying the GT strength distribution and the corresponding closed-core structure.

B(GT)In the previous report1) , we presented the resultsof shell-model calculations with an eﬀective interaction determined for the use around 100 Sn. We adopted
the model space consisting of four orbits 1p1/2 , 0g9/2 ,1d5/2 and 0g7/2 assuming a hypothetical “core” 76
38 Sr38 .
2)
Starting with a G-matrix interaction, the Hamiltonian parameters were modiﬁed by iterative ﬁts to experimental energy data. The shell-model results reasonably described the systematics of energy levels andelectromagnetic transitions for nuclei around 100 Sn.
As a next step, we report on the Gamow-Teller(GT) transition from 100 Sn using the same shell-model
framework. Since 100 Sn is a doubly-magic, jj-closed
N = Z nucleus, some similarity to 56 Ni is expected. In
the case of 56 Ni, the GT transition is dominated by theπf7/2 → νf5/2 excitation, and in the extreme singleparticle picture the ﬁnal state is described by a 1p-1h
conﬁguration on top of the closed 56 Ni core. However,according to the realistic shell-model calculations, theGT strengths are distributed over many states due tothe conﬁguration mixing. We have reported3) that the“double-peak” structure in the strength distribution
becomes signiﬁcant after including 4p-4h components.
Therefore it is interesting to examine whether the similar structure could be seen in the case of 100 Sn.
Since the GT transition from 100 Sn should be dominated by the πg9/2 → νg7/2 excitation, we can expect a reasonable description in the present model
space. At the price of the lack of some (possibly minor)
components such as the πd5/2 → νd3/2 , the present
model space allows us to take into account the eﬀects
of suﬃciently many np-nh conﬁgurations. The calculated GT strength distribution is shown in Fig.1. Although we don’t see clear “double-peak” structure inthis case even at the t=5 truncation level, the splittingof the strength becomes signiﬁcant as more and moreparticle-hole conﬁgurations are included.
In the recent β-decay experiment of 100 Sn4) , a possible “superallowed” GT transition corresponding to
B(GT)=7.6+2.2−2.5 was observed. The analysis was madeunder the assumption that the GT decay goes into
the single ﬁnal 1+ state of 100 In. This assumption
was supported by large-scale shell-model calculationsin the gds model space, which predict the concentra-

10
5
0
10
5
0
10
5
0
10
5
0
10
5
0
10
5
0

100

Sn →

100

In

t=0

t=1

t=2

t=3

t=4

t=5
0

2
4
6
8
10
100
Ex (MeV) in
In (t=6)

12

Fig. 1. The GT transition strength from 100 Sn calculatedby the shell model varying the truncation order t, which
stands for the number of nucleons allowed to excite fromthe lower orbits (p1/2 , g9/2 ) to the higher orbits (d5/2 ,g7/2 ). The discrete strengths indicated by thick verticalbars are obtained by the prescription in Ref.5) through100 Lanczos iterations, and they are folded by Gaussian of σ=0.5MeV as shown with a smooth curve. No
quenching factor is considered for the purpose of comparison. The shell-model results are obtained by using
the eﬃcient code MSHELL646) .

References
1) M. Honma et al.: RIKEN Accel. Prog. Rep. 47, in press.
2) M. Hjorth-Jensen et al.: Phys. Rep. 261, 125 (1995).
3) M. Honma et al.: RIKEN Accel. Prog. Rep. 46, 45 (2012).
4) C. B. Hinke et al.: Nature 486, 341 (2012).
5) R. R. Whitehead: in Moment Methods in Many Fermion
Systems, edited by B. J. Dalton et al. (Plenum, New
York, 1980), p. 235.
6) T. Mizusaki et al.: MSHELL64 code (unpublished).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Reentrance phenomenon of superfluid pairing in hot rotating nuclei
N. Quang Hung,∗1 N. Dinh Dang,∗2 B.K. Agrawal,∗3 V.M. Datar,∗4 A. Mitra,∗4 and D.R. Chakrabarty∗4

∗1
∗2
∗3
∗4

School of engineering, Tan Tao University, Long An
RIKEN Nishina Center
Theory Division, Saha Institute of Nuclear Physics, Kolkata
Nuclear Physics Division, Bhabha Atomic Research Center,
Mumbai- 90 -1012

ρ (MeV -1 )

1010
8

10

Exp
FTBCS
FTBCS1

10 6
104

10

_

_

102

(b) J = 10 h(a) J = 0 h

0

1010

ρ (MeV -1 )When a nucleus rotates (total angular momentum J
and/or rotational frequency ω are not zero), the nucleon (proton and neutron) pairs located around the
Fermi surface will scatter to the empty levels nearby
and lead to the decreasing of pairing correlation. When
the J or ω is sufficiently high, i.e., equal to the criticalvalue Jc or ωc , the scattered nucleons completely block
the single-particle levels around the Fermi surface.
Consequently, pairing correlation disappears. However, when J is slightly higher than Jc (or ω ≥ ωc ), theincrease of temperature T will relax the particles scattered around the Fermi surface and causes some levels
become partially unoccupied, making them available
for scattered pairs. As a result, the pairing correlation reappears at some critical value T1 . As T goeshigher, e.g., at T2 > T1 , the newly created pairs will
be eventually broken down again. This phenomenon
is called the pairing reentrance. The recently developed FTBCS1 theory that includes the effect due toquasiparticle-number fluctuations in the pairing field
and angular momentum z projection at T �= 0 has
predicted the pairing reentrance effect in some realistic nuclei1) . The shell-model Monte Carlo calculations
have suggested that the pairing reentrance effect canbe observed in the nuclear level density in a form of
a local maximum at low T (or excitation energy E ∗ )and high J (or ω). Recently, an enhancement of level
density of 104 Pd at low E ∗ and high J has been experimentally reported2) . In this work we try to see
whether the enhancement observed in the extracted
level density of 104 Pd is an experimental evidence of
pairing reentrance phenomenon in atomic nuclei.
The FTBCS1 equations at finite temperature andangular momentum are derived based on the variational method to minimizethe expectation value of thepairing Hamiltonian H = k ǫk (a†+k a+k + a†−k a−k ) −G kk′ a†k a†−k a−k′ ak′ − λN̂ − ω M̂ , in the grandcanonical ensemble. This Hamiltonian describes a system rotating about the symmetry axis, which is chosen
to coincide with its z component. The particle-number
operator N̂ and the z projection M̂ of the total angular momentum Jˆ (which coincides with M̂ for spheri
cal nuclei) are defined as N̂ = k (a†+k a+k + a†−k a−k ) ,M̂ = k mk (a†+k a+k − a†−k a−k ) , where a†±k (a±k ) are
the creation (annihilation) operators of a particle in
the k-th deformed state, whereas ǫk , λ, and ω are respectively the single-particle energies, chemical poten-

108
10 6
104
_

_

(c) J = 20 h102(d)J = 30 h

100
0

5

10

15

20

E* (MeV)

25

0

5

10

15

20

25

E* (MeV)Fig. 1. (Color online) Total level densities for 104 Pd asfunction of E ∗ obtained within at the quadrupole deformation parameter β2 = 0.276 at several J. The dottedand dashed lines stand for the FTBCS and FTBCS1
results, respectively. The solid lines are the experimentally extracted level densities

tial, and rotational frequency. The FTBCS1 equation for the pairing gap has the final form as ∆−k =∆ + δ∆k , where ∆ = G k′ uk′ vk′ (1 − n+k ′ − nk ′ ) ,−δ∆k = GδNk2 uk vk /(1 − n+
−
n
)
,
with
u
,
v
k
k , and nkkkbeing the Bogolyubov’ u, v coefficients and quasiparticle occupation numbers, respectively. The total level
density ρ(E, J) is calculated as ρ(E, J) = ρ(E, M =J) − ρ(E, M = J + 1) , where ρ(E, M ) is obtained byusing the inverse Laplace transformation of the grandpartition function.
Because of quasiparticle number fluctuations, theFTBCS1 gaps decrease monotonically with increasing
excitation energy E ∗ and do not collapse at E ∗ = Ec∗
as in the case of the FTBCS. Within the FTBCS1, thepairing reentrance is seen very clearly at J = 20h̄ forneutrons and at J = 30h̄ for protons. Consequently,
there appear local enhancements in the FTBCS1 level
densities at around 2 < E ∗ < 5 MeV at these two values of J(Fig. 1). The FTBCS1 level densities agree
fairly well with the experimental data at all J values
considered in present work.
References
1) N.D. Dang and N.Q. Hung, Phys. Rev. C 77 ), 064315(2008); N.Q. Hung and N.D. Dang, Phys. Rev. C 78,
064315 (2008), Phys. Rev. C 84, 054324 (2011).
2) A. Mitra et al., J. Phys. G 36, 095103 (2009); A. Mitra
et al., EPJ Web of Converences 2, 04004 (2010); V.
Datar, A. Mitra, and D.R. Chakrabarty, unpublished.

30

Ⅱ-2. Nuclear Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Giant dipole resonance in highly excited nuclei†

The present work summarizes the achievements of
the Phonon Damping Model (PDM)1) in the description of the the GDR width and shape at finite temperature T and angular momentum J. The GDR parameters predicted by the PDM and experimentally
extracted are also used to calculate the shear viscosityof finite hot nuclei.
The PDM’s Hamiltonian consists of the independent
single-particle (quasiparticle) field, GDR phonon field,
and the coupling between them. The Woods-Saxon
potentials at T = 0 are used to obtain the singleparticle energies ǫk . The GDR width Γ(T ) is a sum:Γ(T ) = ΓQ +ΓT of the quantal width, ΓQ , and thermal
width, ΓT . In the presence of superfluid pairing, thequantal and thermal widths are ΓQ = 2γQ (EGDR ) =(+)
2πF12 ph [uph ]2 (1 − np − nh )δ[EGDR − Ep − Eh ] ,(−)
and ΓT = 2γT (EGDR ) = 2πF22 s>s′ [vss′ ]2 (ns′ −(+)
ns )δ[EGDR − Es + Es′ ] , where uph = up vh + uh vp ,FWHM (MeV)
(MeV)
FWHM

N. Dinh Dang∗1
120
120

Sn
Sn

PDM
PDM
FLDM
FLDM
pTSFM
pTSFM
AM
AM

15
15
10
10

BraccoBraccoEndersEndersBaumann
Baumann
Heckmann
Heckmann
Kelly
Kelly

55
00

1
1

2
3
2
3
T
T (MeV)
(MeV)

†
∗1

Condensed from the article in EPS Web of Conferences 66,
02024 (2014)
RIKEN Nishina Center- 91 -

5
5

Fig. 1. GDR width for 120 Sn predicted by the PDM, phenomenological thermal shape fluctuations (pTSFM),
adiabatic (AM), and Fermi liquid drop (FLDM) models
as functions of T in comparison with experimental datain tin regions.

(−)

12
10
8
6
4
2
0

120

Sn

_

η/ s ( h /4π kB )vss′ = us us′ − vs vs′ (ss′ = pp′ , hh′ ) with the coefficients of Bogolyubov’s transformation
uk and vk ,quasiparticle energies Ek ≡ (ǫk − λ)2 + ∆2 , superfluid pairing gap ∆, and quasiparticle occupations
numbers nk = [exp(Ek /T ) + 1]−1. F1 is chosen so that
ΓQ at T = 0 is equal to GDR’s width at T = 0; F2 ischosen so that, with varying T , the GDR energy EGDR
does not change significantly. EGDR is the solution of
EGDR − ωq − Pq (EGDR ) = 0, where ωq is the energyof the GDR phonon before the coupling between thephonon and single-particle mean fields is switched on,
and Pq (ω) is the polarization operator owing to thiscoupling. In numerical calculations the representation
δ(x) = limε→0 ε/[π(x2 + ε2 )] is used for the δ-function
with ǫ = 0.5 MeV.
In the verification of the condition for applying hydrodynamics to nuclear system, the quantum mechanical uncertainty principle requires a finite viscosity for
any thermal fluid. It has been conjectured that theratio η/s of shear viscosity η to the entropy volume
density s is bounded at the lower end for all fluids,
namely the value η/s = h̄/(4πkB ) is the universal
lower bound (KSS bound or unit). From the viewpointof collective theories, one of the fundamental explanations for the giant resonance damping is the friction
term (or viscosity) of the neutron and proton fluids.
The exact expression for the shear viscosity η(T ) interms of the GDR’s parameters at zero and finite T
was obtained as η(T ) = η(0)[Γ(T )/Γ(0)]{EGDR (0)2 +[Γ(0)/2]2 }/{EGDR (T )2 + [Γ(T )/2]2 }. The predictions

4
4

KSS bound

0

1

2
3
T (MeV)

4

5

Fig. 2. The ratio η/s as a function of T for nuclei in thetin region. The gray areas are the PDM predictions byusing 0.6u ≤ η(0) ≤ 1.2u with u = 10−23 Mev s fm−3 .

for the GDR width and the ratio η/s by the PDM,
pTSFM, AM, and FLDM for 120 Sn are plotted as functions of T in Figs. 1 and 2 in comparison with the empirical results. The latter are extracted from the experimental systematics for GDR in tin region making
use this exact expression. It is seen that the predictions by the PDM have the best overall agreement withthe empirical results. Based on these results and on
a model-independent estimation, it is concluded thatη/s for medium and heavy nuclei at T = 5 MeV is in
between (1.3 - 4.0) KSS units.
References
1) N. Dinh Dang and A. Arima, Phys. Rev. Lett. 80, 4145
(1998); Nucl. Phys. A 636, 427 (1998); Phys. Rev. C
68, 044303 (2003).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Theoretical analysis of 132 Xe by generator coordinate method
N. Yoshinaga,∗1,∗3 K. Higashiyama,∗2 and E. Teruya ∗1

=

∑
i

Iτ
∑

Kτ =−Iτ

�
⟩
Iτ i
FK
P̂ Iτ
P̂Nτ �Φτ (βi , γi ) ,τ ρ Mτ Kτ

(1)Iτ
where P̂M
is the spin projection operator, P̂Nτ is
τ Kτ
Iτ i
the particle-number projection operator, FK
is theτρweight function to be determined by solving the HillWheeler equation, and i stands for a representative
point with deformation (β, γ). Then, the wave function
∗1
∗2
∗3

Department of Physics, Saitama University
Department of Physics, Chiba Institute of Technology
RIKEN Nishina Center- 92 -

4

3

E(MeV)

Xe, Ba, and Ce nuclei in the mass A ∼ 130 region exhibit γ-instability in low-lying states, which is characterized by energy staggering of the even-odd spin statesin the quasi-γ band and by some forbidden transition
rates between the yrast and quasi-γ bands. The energy levels and decay properties of the low-lying states
were discussed in the framework of the interacting boson model1) , where quadrupole collective excitations
are described in terms of the angular momenta zero(s) and two (d) bosons.
Another characteristic feature of even-even nuclei
is the irregular level sequence in the yrast band, i.e.,the backbending phenomenon, which is interpreted asband crossing between the ground-state band and thes band originating from the alignment of two neutronsin 0h11/2 orbitals. Sudden decreases in the level spacing and the E2 transition rates are observed around thestates of spin 10. Recently, full-fledged shell-model calculations have been performed for the even-even, oddmass and doubly-odd nuclei in this mass region2) . The
shell-model calculations well reproduce the experimental energy levels and electromagnetic transition rates.
In the present study, we apply the quantum-numberprojected generator coordinate method (GCM) to132
Xe under the same interaction used in the previous shell model studies2) . All the five orbitals, 0g7/2 ,1d5/2 , 1d3/2 , 0h11/2 and 2s1/2 , in the major shell of
50 ≤ N (Z) ≤ 82 are considered, and valence neutrons(protons) are treated as holes (particles).
In the present scheme, spins of the neutron and proton systems (Iν and Iπ ) are projected separately, andthe total spin is constructed by angular momentum
coupling. To generate functions for the GCM in aneutron or proton system (τ = �ν or π), ⟩we employ
the Nilsson BCS intrinsic states �Φτ (β, γ) , where β
and γ indicate axial and triaxial quadrupole deformations, respectively. The ρth GCM wave function withangular momentum Iτ in neutron or proton space isgiven by� (τ ) ⟩�ΨIτ Mτ ρ

2

1

0

+

132

Xe

12
12

+

+
6
6

+
+

4
4

+

+
3
3
+

+
2
2

+

+
+

+

+
6
6

6
6

+

+
3
3
+
+

4
4

+

+
2
2

+

+

+
0
0

10
10

+

+
8
8
+

+
5
5++
4
4

+

+
6
6

+

+
0
0

+
+

4
4

+
7
7
+

+
8
8
+

+
6
6
+

+
4
4
+

+
0
0

+

+
8
8
+

+
6
6

+
+

5
5

+

+
4
4

+

+

+
8
8
+

+
3
3
+
+
6
6
+

+
4
4
+
2
2
+

+
0
0

+

+
2
2

+

+
0
0

+

+
5
5

+
2
2

+

SM

+
7
7

+

+

+
3
3

+
2
2

+

expt.

+

+
10
10

8
8

+
+

+
+

+

+

+
2
2

+

+
2
2

+
0
0

+

+
5
5
+
+
4
4

+

+
7
7

+
8
8

+

+
12
12

+
12
12

+

+
10
10

+

+
(10
(10 ))
+
6
6

+

+
+

+

+
0
0

triaxial

axial

Fig. 1. Comparison of the experimental energy levels(expt.) with the shell-model (SM) results, those in thetriaxial GCM (triaxial), and those in the axial GCM(axial).

for an even-even nucleus can be written as
�
⟩ [�
⟩ �
⟩](I)
�ΨIM (Iν ρIπ σ) = �Ψ(ν) ⊗ �Ψ(π)
,
Iν ρ
Iπ σ
M

(2)

where I is the total spin and M is its projection. GCM
calculations are carried out for two cases: (i) triaxial deformations (9 points) with β = 0.10, 0.20, 0.30,
γ = 10◦ , 30◦ , 50◦ ; (ii) only axial deformations (49points) with β = 0.00, 0.02, 0.04, · · · , 0.48 and γ = 0◦ ,60◦ . In Fig. 1, experimental energy levels are comparedwith the shell-model results, and those in the GCM.
In both cases of triaxial and axial deformations, theGCM well reproduces the experimental energy levelsof the even-spin yrast band and those obtained by theshell model. In the case of other excited states, theGCM calculations performed by assuming triaxial deformation are in good agreement with the shell model+++
results, especially for the 2+
2 , 31 , 42 , and 51 states,
which are members of the γ-band. However, energy
levels calculated by assuming only axial deformation++
for the 3+
1 , 51 , and 71 states are much higher thanthose calculated using the shell model. Apparently,+++
the description of the 2+
2 , 31 , 42 , and 51 states is notsatisfactory when assuming only the axially symmetricshape. The triaxial components play an essential rolein the description of these states.
References
1) F. Iachello and A. Arima: The Interacting Boson
Model, (Cambridge University Press, Cambridge, England, 1987).
2) E. Teruya, N. Yoshinaga, K. Higashiyama, and A. Odahara, to be published.

Ⅱ-2. Nuclear Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Tops-on-top model applied to TSD bands in 164 Lu†
K. Sugawara-Tanabe,∗1,∗2 K. Tanabe,∗1,∗3 and N. Yoshinaga∗3
The top-on-top model with moments of inertia(MoI) dependent on angular-momentum (I) works
quite well in describing triaxial strongly deformed(TSD) bands in odd-mass nuclei.1–3) In this paper, thetop-on-top model is extended to the tops-on-top model
for an odd-odd nucleus 164 Lu, in which one proton andone neutron in each single-j orbital are coupled to thetriaxial rotor.
Both positive- and negative- parity TSD bands in
164
Lu are well reproduced by taking account of attenuation factors in the Coriolis interaction, which includes the eﬀect of the partially ﬁlled single-j shell. In
order to observe the eﬀect of the attenuation factor,
we compared numerical results with and without theattenuation factor and conﬁrmed its importance forthe excitation energies relative to the reference, i.e.,E ∗ − aI(I + 1) with a = 0.0075 MeV.4,5)
For a pure-rotor case without single-particle potentials, an explicit algebraic formula for the TSD band
levels is obtained. The level is classiﬁed by three quantum numbers (nα , nβ , nγ ), where nα is related to therotor wobbling quantum number, and nβ and nγ to theprecession quantum numbers for a proton and a neutron. Under the condition of D2 -invariance,6) threequantum numbers take limited integers depending on
the value of I − j1 − j2 and nα − nβ − nγ . As an
example, we assume j1 = j2 = 13/2, and compare
the energy eigenvalues from this boson model with theresult obtained from the exact diagonalization of therotor Hamiltonian in Fig. 1 for odd number I whereI − j1 − j2 is even. In this case nβ and nγ appear as
the combination np = nβ + nγ . The yrast has quantum numbers (0, 0) and the yrare (0, 2)3 . On the other
hand, for even number I where I − j1 − j2 is odd, theyrast has quantum numbers (1, 0) and the yrare (2, 1)2 .
The boson model reproduces the exact results in good
accuracy.
It is easy to derive the stability condition for a purerotor case. We found that there is no wobbling aroundthe axis with the intermediate MoI. The wobbling motion exists only around the axis with the maximum or
minimum MoI, which agrees with the result in classicalmechanics.7) Consequently, we can state that there is
no stable rotation around the axis with the intermediate MoI, and that stable rotational motion exists onlyaround the axis with the maximum or minimum MoI.
The diﬀerence in quantum numbers between the
yrast and yrare TSD bands in 164 Lu, in which single†
∗1
∗2
∗3

Condensed from the article in Prog. Theor. Exp. Phys.,Vol.2014, 063D01 (2014)
RIKEN Nishina Center
Otsuma Women’s University
Department of Physics, Saitama University- 93 -EMeV
3
2.5

31
31
31

2

31
31

31

1.5
1
0.5
0

15
13

0,0

15
13

0,23

17
15

2,0

17
15

1,12

19
17

3,12

19
17

4,0

-0.5

Fig. 1. Comparison of the energy levels of odd spin I(13 ≤ I ≤ 31) between the boson model (solid lines) andthe exact result (dashed lines). Quantum numbers anddegeneracy of levels (np + 1) are given by (nα , np )np +1
below each rotational band. Angular momentum values
are assigned to the lowest two levels and the highest
level in the right-hand side of each band.

particle potentials are included, is conﬁrmed by direct
estimation of spin alignments. It is conﬁrmed that the
yrast TSD band with even I−j1 −j2 has quantum numbers (nα , nβ , nγ )=(0,0,0), while the yrare TSD bandwith odd I − j1 − j2 has (1,0,0).
The electromagnetic transition rates of B(M 1) are
reduced by a factor of 1/20 because the signs of gfactors of a proton and a neutron are diﬀerent in comparison with the odd-A case, while the electromagnetictransition rates of B(E2) are in the same order but
reduced by a factor of 1/2. These reductions of electromagnetic transition rates will make the observationof TSD bands in even-even nuclei diﬃcult.
References
1) K. Tanabe and K. Sugawara-Tanabe: Phys. Rev. C 73,
034305 (2006).
2) K. Tanabe and K. Sugawara-Tanabe: Phys. Rev. C 77,
064318 (2008).
3) K. Sugawara-Tanabe and K. Tanabe: Phys. Rev. C 82,
051303(R) (2010).
4) S. Törmänen et al.: Phys. Lett. B 454, 8 (1999).
5) P. Bringel et al.: Phys. Rev. C 75, 044306 (2007).
6) A. Bohr: Mat. Fys. Medd. Dan. Vidensk. Selsk. 26,
no. 14 (1952).
7) L. D. Landau and E. M. Lifshitz:
Mechanics(Butterworth-Heinemann, Oxford, 1976), 3rd ed.,Sect. 37.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Recent progress and open issues on pseudospin and spin symmetries†
H. Z. Liang,∗1 J. Meng,∗1,∗2 and S.-G. Zhou∗3∗3- 94 -









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
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`I

J



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a 
`G
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
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



∗2

Condensed from the article in Phys. Rep. 570, 1 (2015)
RIKEN Nishina Center
School of Physics, Peking University
Institute of Theoretical Physics, Chinese Academy of Sciences





I

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

∗1

V

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
S

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

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



†


S

I

K

V

G
J

S

I
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J
a 
`K


L


Then, three of the open issues in this ﬁeld were selected and discussed in detail, i.e., the perturbative natureof PSS, the puzzle of intruder states, and the supersymmetric (SUSY) representation of PSS.
For the perturbative nature of PSS, we emphasizedthat the symmetry breaking behaves perturbatively
depending on whether an appropriate symmetry limit
is chosen and an appropriate symmetry-breaking term
is identiﬁed. As long as an appropriate symmetry limit
is chosen, the nature of PSS is indeed perturbative.5)
For the puzzle of intruder states, we showed several
diﬀerent features about this puzzle, i.e., the bound states in the non-conﬁning or conﬁning potentials, thebound and resonant states identiﬁed by the zeros of
Jost function,6) a continuous transformation between
SS and PSS, and the SUSY transformation of the PSS
scheme. By doing so a number of “contradicting” results in the literature for the spin (pseudospin) part-

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V

G

J

L



• From stable nuclei to exotic nuclei• From non-conﬁning to conﬁning potentials• From local to non-local potentials• From central to tensor potentials• From bound states to resonant states• From nucleon spectra to anti-nucleon spectra• From nucleon spectra to hyperon spectra• From spherical nuclei to deformed nuclei






Pseudospin symmetry (PSS)1,2) was introduced to
explain the near degeneracy between pairs of nuclear
single-particle states with the quantum numbers (n −1, l + 2, j = l + 3/2) and (n, l, j = l + 1/2). They
are regarded as pseudospin doublets by deﬁning thequantum numbers (ñ = n − 1, ˜l = l + 1, j = ˜l ± 1/2),
as illustrated in Fig. 1.
This observation raised a fascinating question
whether such near degeneracy is accidental (a degeneracy not explained by an obvious symmetry) or due
to symmetry breaking (more descriptively hidden symmetry). Since PSS was recognized as a relativistic symmetry in the 1990s,3) many special features, including
the spin symmetry (SS) for anti-nucleons,4) and many
new concepts have been introduced in relevant studies, which led to several exciting discoveries during thepast decade.
In this review article,† we intended to systematically provide a comprehensive overview on the recent
progress. The PSS and SS in various systems and potentials were discussed based on the following aspects:

Fig. 1. Schematic nuclear single-particle spectrum. Pairs of
single-particle states in braces are defined as the pseudospin doublets.

ners have been clariﬁed explicitly.
For the SUSY representation of PSS, we pointed out
one of the promising ways for understanding the PSS
and its symmetry breaking, by combining the similarity renormalization group, the SUSY quantum mechanics, and the perturbation theory.7) Meanwhile, application of the SUSY technique directly to the Diracequations, which have non-trivial scalar and vector potentials, remains an interesting and open proposition.
Another important issue is the experimental signalsof these symmetries. So far, several nuclear structure
phenomena have been interpreted directly or implicitly by the PSS, including nuclear superdeformed conﬁgurations, identical bands, quantized alignment, andpseudospin partner bands. The relevance of PSS in the
structure of halo nuclei and superheavy nuclei was also
pointed out. More experimental evidences for PSS are
highly desired for future studies.
References
1) A. Arima, M. Harvey, and K. Shimizu: Phys. Lett. B
30, 517 (1969).
2) K. Hecht and A. Adler: Nucl. Phys. A 137, 129 (1969).
3) J. N. Ginocchio: Phys. Rev. Lett. 78, 436 (1997).
4) S.-G. Zhou, J. Meng, and P. Ring: Phys. Rev. Lett. 91,
262501 (2003).
5) H. Z. Liang et al.: Phys. Rev. C 83, 041301(R) (2011).
6) B.-N. Lu, E.-G. Zhou, and S.-G. Zhou: Phys. Rev. Lett.
109, 072501 (2012); Phys. Rev. C 88, 024323 (2013).
7) H. Z. Liang et al.: Phys. Rev. C 87, 014334 (2013).

Ⅱ-2. Nuclear Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Nuclear moment of inertia in super-normal phase transition region†
K. Tanabe∗1,∗2 and K. Sugawara-Tanabe∗1,∗3

†
∗1
∗2
∗3

Condensed from the article in Phys. Rev. C, Vol. 91, 034328(2015)RIKEN Nishina Center
Department of Physics, Saitama University
Otsuma Women’s University- 95 -

1.04

odd mass

1.02

JJrig

The purpose of this paper is to derive the analytic
expression for the angular momentum (I) dependenceof the moment of inertia (MoI) from the microscopic
many-body theory both for even-even and odd-massnuclei. The I-dependence of MoI has been proved tobe essential in simulating triaxial, strongly deformed(TSD) bands in a series of papers.1–4)
We adapt the approximation developed for the gap(Δ) dependence of the ratio of MoI (J) to the rigidbody value (Jrig ).5,6) It assumes that only large matrix elements of single-particle angular momentum of(jx )αβ contribute to J with a common excitation energy of δ(= εβ − εα ), where εα denotes the singleparticle energy of the level α. We apply this approximation to the gap equation including the Coriolis antipairing (CAP) eﬀect7) through the second-order perturbation to the cranking term.8,9)
When Δ is larger than half of the single-particle level
distance d, we can apply a deﬁnite integral for the gap
equation with the CAP eﬀect. When Δ is smaller thanhalf of d, we propose the ﬁnite sum method with the
picket-fence approximation for the level distribution.
In this case, it is proved that Δ never tends to zero,and there is no sharp phase transition from the superconducting state to the normal state. Neglecting thehigher order in 2Δ/δ for the case Δ < d/2 (ﬁnite sum
method), we express MoI as an analytic function of I.
In Fig. 1, we compare the approximate solution between even-even and odd-mass nuclei as functions of I
measured from the band-head angular momentum I0 .
Usually, I0 = 0 for even-even nucleus, while I0 �= 0
for odd-mass nucleus, for example, I0 = 13/2 for the
TSD yrast band in 163 Lu.10) We choose the singleparticle energy for a valence nucleon as ε� = 0.6 MeV
above the Fermi surface, and the initial pairing gap at
I=I0 for odd mass as 0.6 MeV, smaller than 0.8 MeV
for even-even nucleus (blocking eﬀect). The blocking
eﬀect reduces the starting value of Δ and increases
that of the MoI. In odd-mass case, there is a termthat correlates the single-particle state of � with αthrough (jx )2α� . The matrix element of (jx )2α� is chosen to be 12 for εα > ε� and 10 for εα < ε� . The
other parameters are the same as those for the eveneven case. We have started both approximate solutions
with Δ = 0.15 MeV corresponding to I−I0 ∼15, whiled = 0.4 MeV.
As is seen in Fig. 1, the main diﬀerence between
even-even (dashed line) and odd-mass (solid line) nu-

1eveneven

0.98
0.96
0.94
0.92
15

20

25

30

35

40

II0
Fig. 1. Comparison of the ratio J/Jrig in the approximate
sum method as functions of I-I0 for even-even (dashedline) and odd-mass (solid line) nuclei.

clei is from the blocking eﬀect. Then, both curves increase gradually, and approach the value 1. The MoIof odd-mass case is chosen to be slightly larger thanthat of the even-even case. The curves become convex upward before they reach to rigid-body values.
This upward convexity is also necessary for explaining the energy sequence of TSD bands.4) For the caseof Δ ≥ d/2 (deﬁnite integral), J goes to Jrig around
I−I0 ∼ 17 or 18 (sharp phase transition). Even in thiscase, odd-mass nuclei show an upward convexity before the phase transition at I=17 ∼ 18. Because oflarger I0 , the slow phase transition occurs at larger I
for odd-mass nuclei than for even-even nuclei.
References
1) K. Tanabe and K. Sugawara-Tanabe: Phys. Rev. C 73,
034305 (2006).
2) K. Tanabe and K. Sugawara-Tanabe: Phys. Rev. C 77,
064318 (2008).
3) K. Sugawara-Tanabe and K. Tanabe: Phys. Rev. C 82,
051303(R) (2010).
4) K. Sugawara-Tanabe, K. Tanabe and N. Yoshinaga:
Prog. Theor. Exp. Phys. 2014, 063D01 (2014).
5) A. Bohr and B. R. Mottelson: N uclear Structure (Benjamin, Reading, MA, 1975), Vol. II.
6) D. Bengtsson and J. Helgessen: Lecture notes in a summer school at Oak Ridge (1991).
7) B. R. Mottelson and J. G. Valatin: Phys. Rev. Lett. 5,511 (1960).
8) M. Sano and M. Wakai: Nucl. Phys. 67, 481 (1965).
9) K. Sugawara: Prog. Theor. Phys. 35, 44 (1966).
10) S. W. Ødegård et al .: Phys. Rev. Lett. 86, 5866(2001).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-2. Nuclear Physics (Theory)

Joint project for large-scale nuclear structure calculations in 2014
N. Shimizu,∗1 T. Otsuka, ∗1,∗2 T. Togashi,∗1 N. Tsunoda,∗2 and Y. Utsuno∗1,∗3
A joint project for large-scale nuclear structure calculations has been promoted since the year 2002 basedon a collaboration agreement between the RIKEN Accelerator Research Facility (currently RIKEN Nishina
Center) and the Center for Nuclear Study, the University of Tokyo. Currently, we maintain 16 PC servers
with Intel CPUs for large-scale nuclear shell-model calculations. One of the servers has 40 CPU cores and
1TB main memory. Based on this project, we performed shell-model calculations of the various nuclides
which had been measured at the RIKEN RI Beam Factory, such as 31 Ne, 33 Mg, and 50 Ar under collaborations with many experimentalists.1) Since the resultsof these collaborations are presented in other reports,
here we introduce four theoretical achievements of thisproject in 2014: development of a shell-model code,shell-model analyses of the isomeric states of 43,44 S
and high-spin states of neutron-rich Cr, Fe isotopes,
and an application of the extended Kuo-Krenciglowa(EKK) method in understanding the island of inversion.
We developed a new code, named “KSHELL” forlarge-scale shell-model calculations on state-of-the-art
supercomputers2) . In nuclear shell-model calculations,
we solve an eigenvalue problem of the Hamiltonian
matrix, whose dimension tends to be huge, by including many-body correlations fully inside the model
space. The newly developed code enables us to solve
this eigenvalue problem by using many CPU cores efﬁciently.
We have investigated the structure of exotic nuclei
in the N ∼ 28 region, which attracts much attention in experimental studies using RIBF. In our mostrecent work3) , we focus on the nature of exotic isomeric states in neutron-rich S isotopes, in particular+
44 4)strongly hindered E2 decay from 4+S .
1 and 21 inThis study is based on shell-model calculations using
the SDPF-MU interaction5) which was developed inthis joint project. In order to extract intrinsic statesfrom the shell model, we carry out the variation after
angular-momentum projection (AM-VAP). The AMVAP calculation shows that the 4+
1 level is dominatedby a K = 4 intrinsic state and that this is the origin
44of the strong E2 hindrance. The 4+
S is the1 level inlightest high-K isomer among the ones ever identiﬁedin the A ∼ 100, A ∼ 130, A ∼ 180, and A ∼ 250
regions.
We have performed large-scale shell model calculations for natural- and unnatural-parity states in Cr and
∗1
∗2
∗3

Center for Nuclear Study, University of Tokyo
Department of Physics, University of TokyoJapan Atomic Energy Agency- 96 -

Fe isotopes with N ≤ 356) . Unnatural positive-parity
states in odd-mass Cr and Fe nuclei with N ≤ 35 wereobserved experimentally from low-lying energy levels
to high-spin ones. These states are dominated by oneparticle one-hole excitation across the N = 40 shellgap. The model space of our calculation is composedof f p-shell + 0g9/2 + 1d5/2 orbits with the truncation
allowing 1h̄ω excitation of a neutron. It eﬀectively describes and predicts the energy levels up to the highspin states. The eﬀective single-particle energies ofν0g9/2 in Cr and Fe isotopes are rather constant in theregion with N ≤ 35. This indicates that the sharp
drop of the 9/2+
1 levels in this mass region, which is
discussed as an indication of the evolution of ν0g9/2 , isexplained by the Fermi surface approaching the ν0g9/2
orbit with the increase of neutron number.
Investigation of the neutron-rich nuclei starting fromthe fundamental nuclear force has been accomplishedby the newly constructed EKK method7) . To construct
the eﬀective interaction for the shell model startingfrom the nuclear force, we usually utilize the manybody perturbation theory, but the standard perturbation theory ends up with a series of divergences whenapplied to a large shell-model space, for example, themodel space spanned by two major shells. The EKK
method avoids a divergence with a re-summation of
the perturbative series and makes it possible to construct the eﬀective interaction for more than one major
shell. We constructed the eﬀective interaction for thesdpf -shell, starting from the N3LO interaction with
the EKK method. The contribution from the threebody force is also added as eﬀective two-body interactions. We found that this interaction consistently
describes the ground state energies and low-lying levels of even-even nuclei (O, Ne, Mg, Si isotopes). In
particular, the disappearance of the N = 20 gap of
Ne, Mg isotopes and the restoration of the N = 20
gap of Si and S isotopes are well described.
References
1) T. Nakamura et al.: Phys. Rev. Lett. 112, 142501(2014).
2) N. Shimizu, arXiv:1310.5431 [nucl-th].
3) Y. Utsuno, N. Shimizu, T. Otsuka, T. Yoshida, and Y.
Tsunoda: Phys. Rev. Lett. 114, 032501 (2015).
4) D. Gonzalez et al.: Phys. Rev. C 83, 061305(R) (2011).
5) Y. Utsuno, T. Otsuka, B. A. Brown, M. Honma, T.
Mizusaki, and N. Shimizu: Phys. Rev. C 86, 051301(R)(2012).
6) T. Togashi, N. Shimizu, Y. Utsuno, T. Otsuka, and M.
Honma: Phys. Rev. C 91, 024320 (2015).
7) N. Tsunoda, K. Takayanagi, M. H.-Jensen, and T. Otsuka: Phys. Rev. C 89, 024313 (2014).

3. Nuclear Data

Ⅱ-3. Nuclear Data

RIKEN Accel. Prog. Rep. 48 (2015)

Development of a new EXFOR editor system
A. Sarsembayeva,∗1,∗2 S. Imai,∗1,∗2 S. Ebata,∗1,∗2 M. Chiba,∗3 K. Katō,∗1 N. Otuka,∗4,∗5 and M. Aikawa∗1
The International Network of the Nuclear Reaction
Data Centers (NRDC)1) is a worldwide network of nuclear data centers organized under the auspices of theInternational Atomic Energy Agency (IAEA). NRDC
was established to collect experimental data from allover the world, initially addressing the data needs ofthe fission reactor industry.
The present aim of the NRDC is to encompass all
types of nuclear reaction data, including neutron- andcharged particle-induced data, as well as photonuclear
data. Such data are required for many nuclear applications such as accelerator-driven systems, fusion reactors, nuclear medicine, materials analysis, environmental monitoring, and basic research2) . Since the early
80s, the Nuclear Reaction Data Centre of Hokkaido
University (JCPRG, formerly Japan Charged-Particle
Nuclear Reaction Data Group)3) an active member of
the NRDC.
Under the NRDC, experimental nuclear reaction
data are compiled in a unified format EXFOR (EXchange FORmat) and stored in the library4) . EXFOR
is the main source of experimental nuclear reaction
data and covers results published as early as in the
1930s2) .
In order to make EXFOR compilation easy, various
editor systems have been developed within the NRDC
community. ANDEX5) developed by IAEA-NDS (Vienna) and ERES by CNDC (Beijing)6) are such systems developed in the 1990s. An EXFOR editor developed by CNPD (Sarov) in 2000s is currently used bymany EXFOR compilers. In JCPRG, a web-based nuclear data input system HENDEL (Hyper Editor for
Nuclear Data Exchange Libraries) was developed forthe compilation of experimental nuclear reaction data
in EXFOR and NRDF formats7) . The latter is theoriginal database in JCPRG and is being used as astandard compilation editor system at JCPRG since20018) . For the beginners of EXFOR compilation, theHENDEL system is very useful because it requires only
an elementary knowledge of EXFOR. It is now also
used by young EXFOR compilers in Kazakhstan andMongolia. While the current HENDEL system is welldesigned to create outputs in both NRDF and EXFOR formats, some extra input forms for the creationof NRDF outputs could be rather confusing for foreign compilers. Therefore, development of HENDEL
specialized for EXFOR outputs is of our interest.
Recently, we have started to develop a new HEN∗1
∗2
∗3
∗4
∗5

Faculty of Science, Hokkaido University
Meme Media Laboratory, Hokkaido University
Sapporo-Gakuin University
Nuclear Data Section, International Atomic Energy Agency
RIKEN Nishina Center- 97 -

DEL system using the Java programming language fora stand-alone application type. Java is platform independent and an object-oriented programming language. Note that EXFOR compilers emphasized ina recent EXFOR compilation workshop (6-10 Oct.
2014, Vienna) that it is important to develop an OSindependent EXFOR editor system9) .
We adopt Java Swing API for building a GUI(graphical user interface) application. A main page ofthe new HENDEL editor under development is shownin Fig.#1. Contents of the editor will be organized in a
Tree format. The contents of the editor consist: Bibliography, information commonly applied to all data
sets of the EXFOR entry (Subentry 001), and information applied to each data set of the EXFOR entry
independently (Subentry 002, 003,..). The Bibliography section consists of Title, Author, Affiliation, andReference. One of the new improvements in this editor
is that the Affiliation and Reference part in the Bibliographic section can be multiplied by “+” button, as
shown in Fig. 1.

Fig. 1. Bibliography section of a Java-based Hendel system.

In the current stage, the design of the user interface and inclusion of utilities (e.g., checking tools) havebeen completed.
References
1) N. Otuka (ed.): Report INDC(NDS)-0401 Rev.6, IAEA
(2014).
2) H. Henriksson et al.: Proc. Int. Conf. on Nucl. Data Sci.
Tech., (Nice, 2007), p. 737.
3) Nuclear Reaction Data Centre, http://www.jcprg.org,
2015/04/27.
4) N. Otuka et al.: Nucl. Data Sheets 120 (2014) 272.
5) V. Osolio: Report IAEA-NDS-0101, IAEA (1991).
6) Li Shubing et al.: Report IAEA-NDS-0151, IAEA
(1994).
7) Web-based Editor for Nuclear Data, http://www.
jcprg.org/hendel/, 2015/04/27.
8) N. Otuka et al.: Report INDC(NDS)-0434, IAEA
(2002), p. 144.
9) V. Semkova, B. Pritychenko (eds.): Report INDC(NDS)0672, IAEA (2015).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-3. Nuclear Data

Thick-target yields derived from inverse kinematics toward
transmutation
S. Imai,∗1 M. Aikawa,∗2 and S. Ebata∗1
Nuclear transmutation of long-lived ﬁssion products(LLFP) into stable and short-lived isotopes is considered as an important technique for reducing nuclear wastes in nuclear power plants1) . Thick-target
yields (TTY) on radioactive targets are fundamental and key information for establishing such a technique, although experiments on such radioactive targets suﬀer from high radioactivity. Recent progress inexperimental techniques now allow the utilization ofbeams composed of radioactive isotopes (RI) including LLFP. In fact, an experiment has been performed
at RIBF to obtain cross section data relating to 90 Srand 137 Cs2) . Unstable nuclei of astrophysical interests
have also been applied to obtain cross sections deduced
from the thick-target method of elastic scattering3) .
We therefore suggest an estimation method for the
TTY on a radioactive target based on inverse kinematics. In the case that the projectile is stopped inside thethick target, the TTY denoted by Y is obtained by the
integration value of cross-section σ and density ρ of thetarget, up to the projectile penetration length. Whilethe energy decrease of the projectile is described bydE
the stopping power S(E) = − d(ρx)
at a certain point
x, the TTY can be expressed as:∫
NA AP ϵin1dϵ,(1)
Y (ϵin ) =
σ(ϵ)
AT
S(ϵ)
0

which leads to:dY (ϵ)
NA AP
1
=
,
σ(ϵ)
dϵ
AT
S(ϵ)

(2)

where the Avogadro constant NA , the mass number of
the target AT , the energy per nucleon ϵ = E/AP withthe mass number of the projectile AP and its incident
energy ϵin are used. In this report, we call this system
the forward kinematics and its TTY Yfor .
The inverse kinematics with an RI beam suggeststhat by swapping roles of the radioactive target andincident particle, we can obtain the TTY of the inverse
kinematics system denoted by Yinv . The ratio of the
TTYs between diﬀerential yields, R(ϵ), at the sameenergy ϵ is given by:R(ϵ) ≡

dYfor (ϵ)
A2 Sinv (ϵ)= P2.
dYinv (ϵ)
AT Sfor (ϵ)∗2Table 1. TTY Yfor at two incident energies evaluated from
Eq. (4) taking R ≃ 1.1 and from Eq. (1).
Yfor (ϵin )40 MeV

100 MeV

From Eq. (4)From Eq. (1)0.94 × 10−50.91 × 10−50.113 × 10−3
0.114 × 10−3

We show the example of nat Cu(12 C, X)24 Na5) . In
order to calculate Yfor and Yinv using Eq. (1), the crosssection σ(ϵ) and stopping power S(ϵ) should be known(see in Fig. 1). R(ϵ) shown in Fig. 1 (b) converges
at a constant value at a high energy of more than 50
MeV/A. This simple behavior of R(ϵ) at a high energy
and small σ(ϵ) at a low energy allows us to use a moreconvenient conversion method as:
Yfor (ϵin ) ≃ R̃ Yinv (ϵin ),(4)

where R̃ is a constant value of R(ϵ) at the high energy. Indeed, these are in good agreement with values
derived from Eq. (1) (Table 1).
This conversion method will be applied to radioactive isotopes, such as 137 Cs, and used to search suitableprojectiles for transmutation of LLFP.

(3)
References

Since the σ(ϵ) of both systems are the same and arecanceled out in the ratio, the TTY Yfor (Yinv ) can be
estimated without cross-section if we know Yinv (Yfor ).
Note that the stopping powers Sfor and Sinv can becomputed by SRIM 2008 code4) .
∗1

Fig. 1. Cross-section of nat Cu(12 C,X)24 Na with experimental data5) with spline fitting in (a), and the evaluatedratio R(ϵ) by SRIM 20084) in (b) as functions of ϵ.

Meme Media Laboratory, Hokkaido University
Faculty of Science, Hokkaido University- 98 -

1) W. S. Yang et al.: Nucl. Sci. Eng. 146, 291 (2004).
2) H. Wang et al.: In this report.
3) H. S. Jung et al.: Phys. Rev. C90, 035805 (2014).
4) J. F. Ziegler, J. P. Biersack and M. D. Ziegler:
SRIM: the Stopping and Range of Ions in Matter,
http://www.srim.org.
5) H. Yashima et al.: Phys. Rev. C66, 044607 (2002).

Ⅱ-3. Nuclear Data

RIKEN Accel. Prog. Rep. 48 (2015)

Compilation of nuclear reaction data from the RIBF
D. Ichinkhorloo,∗1 M. Aikawa,∗2 S. Ebata,∗1 N. Furutachi,∗3 S. Imai,∗1 K. Katō,∗2 A. Makinaga,∗4
M. Odsuren,∗5 N. Otuka,∗6,∗7 A. Sarsembayeva,∗1 and B. Zhou∗1
Nuclear reaction data, such as cross sections, angular and energy distributions of secondary particles, andresonance parameters, are required to be compiled into
a database for their users for a large variety of applications and research fields. A nuclear reaction databasethat fulfils this requirement is the EXFOR library,which is maintained by the International Atomic Energy Agency (IAEA) and the International Network of
Nuclear Reaction Data Centres (NRDC). The NRDC
members are involved in data compilation and softwaredevelopment for nuclear data users. Each member is
responsible for compiling data about neutrons, charged
particles, and photon-induced reactions. This responsibility is assigned to members according to area where
the experimental facility to obtain data is located.
One of the NRDC members is the Hokkaido University Nuclear Reaction Data Centre (JCPRG).1)
JCPRG covers nuclear reaction data except neutroninduced data obtained in Japan and contributes about
10% of charged-particle nuclear reaction data in the
EXFOR library.2) At the JCPRG, the compiled nuclear reaction data are stored in two databases, NRDF
and EXFOR libraries, simultaneously. The former isthe original database of JCPRG and the latter is thecollaborative one among the NRDC. Both databases
are available and searchable online on the JCPRG website.
In addition to the NRDC, we have also collaborated
with the RIKEN Nishina Center for data compilationfrom January 2010 to March 2014. The purpose ofthis collabotation is to increase the availability of nuclear reaction data produced at the RIBF. The compiled data produced at the RIBF are translated into
EXFOR format and available online for the benefit ofnuclear data users. In this article, we report on our
activities in 2014 concerning the compilation of experimental nuclear reaction data from the RIBF.
In 2014, we compiled 28 new papers, data of whichwere obtained in Japan. 14 of them contain RIBF
data and match the compilation scope of the EXFOR
library. 10 papers were published in 2013 and 2014
and their compilation reflects recent activities of the
RIBF. On the contrary, the remaining 4 papers were
published before 2009 and compiled for completenessof data published by the RIBF. Especially, 2 papers
∗1
∗2
∗3
∗4
∗5
∗6
∗7

Meme Media Laboratory, Hokkaido University
Faculty of Science, Hokkaido University
Faculty of Engineering, Hokkaido University
Graduate School of Medicine, Hokkaido University
Nuclear Research Center, National University of Mongolia
RIKEN Nishina Center
NDS, IAEA- 99 -

are written in Chinese and were published in 2005 and2006. All data are accessible by the accession numbers
Table 1. Entry numbers with references compiled from the
RIBF data in 2014
Entries

Total

E23983)
E24406)
E24449)E245112)
E245715)

E23994)
E24427)
E244810)
E245513)
E245816)14

E24395)
E24438)E245011)
E245614)listed in Table 1. For higher quality of the contents,
numerical data are requested from the corresponding
authors of the compiled papers. Most of the compiled
RIBF data in 2014 are provided by the authors. Suchadditional information is also available with the list ofcompiled RIBF data on the JCPRG website.
During the four-year fruitful collaboration, we could
establish a good procedure to compile new publications. Therefore, most of recent experimental nuclear
reaction data from the RIBF have successfully been
compiled in the EXFOR library. As a next step, we arefocusing on the improvement of the completeness andusability of the data produced at the RIBF. In addition, we are developing a new data format using XML
technology. The new format will allow us to communicate with experimentalists for proofreading compiled
information.
References
1) http://www.jcprg.org/
2) http://www.jcprg.org/exfor/
3) N. Iwasa et al.: Phys. Rev. C 78, 024306 (2008).
4) Z. Elekes et al.: Phys. Rev. C 79, 011302 (2009).
5) M. U. Khandaker et al.: Nucl. Instrum. Methods Phys.
Res., Sect. B 316, 33 (2013).
6) S. J. Jin et al.: Phys. Rev. C 88, 035801 (2013).
7) G. L. Zhang et al.: High Energy Physics and Nuclear
Physics, 29, 940 (2005) (in Chinese).
8) D. Y. Pang et al.: High Energy Physics and Nuclear
Physics, 30, 22 (2006) (in Chinese).
9) L. Audirac et al.: Phys. Rev. C 88, 041602 (2013).
10) Y. Satou et al.: Phys. Lett. B 728, 462 (2014).
11) H. Haba et al.: Phys. Rev. C 89, 024618 (2014).
12) T. Nakamura et al.: Phys. Rev. Lett. 112, 142501(2014).
13) A. Ozawa et al.: Phys. Rev. C 89, 044602 (2014).
14) S. Michimasa et al.: Phys. Rev. C 89, 054307 (2014).
15) M. U. Khandaker et al.: Nucl. Instrum. Methods Phys.
Res., Sect. B 335, 8 (2014).
16) N. Kobayashi et al.: Phys. Rev. Lett. 112, 242501(2014).

4. Hadron Physics

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Performance improvement of PHENIX MUID
S. Han,＊1, *2 S. Caussin,＊1, *3 I. Nakagawa,＊1 and the PHENIX collaboration
PHENIX Muon Identifier, MUID, is one of the PHENIX
detectors. It has north and south arms, and each arm consistsof 5 layers of alternating energy absorbers andlow-resolution ionization chambers. The chamber iscomposed of many bunches of larocci tubes.1)
During the RHIC-Run 13, the efficiency of the MUID
dropped to less than down under 60% under conditions ofhigh beam luminosity, as shown in Fig. 1. The high voltage
supply system is implemented with 400 M Ωcurrent-limiting resistors, and thus, the voltage is sagged at
the tube as a function the drawing current, which results inthe efficiency drop. The latest performance of MUID
indicated a possible degradation of the efficiency from what
was observed at the early stage of MUID operation a decadeago.
In order to update the performance, we executed the highvoltage(HV) scan in July 2014. The resulting efficiency
curve as a function of HV values demonstrated that thecurrent operation voltage (4400V) is almost the edge of theplateau curve and an additional current draw immediately
leads to a substantial efficiency drop, as shown in Fig. 2.
Overall, more than 50% of the HV chains showed degraded
efficiency performance as compared to that observed in
2004. All these phenomena signify that the plateau of the
MUID became narrower than observed initially. Thus, it isobvious that an improvement of the MUID performance isrequired before starting the RHIC-Run 16. We aim tomeasure Drell-Yan using a high luminosity beam at acollision energy of 500GeV. The MUID efficiency is a topic
of much concern because detection efficiency affects on
square for this measurement.

Fig. 2. Efficiency versus high voltage for south arm gap 0,
panel 5, plane 0. New data (green, black, red points)
indicate a steeper drop than the efficiency turn on curve(blue solid line) observed in 2004.
One of the ways to improve the aforesaid situation is toreconsider the operating HV condition, i.e., if a higher
voltage can be set away from the edge of the plateau. To
define the current plateau region, we explored the higher
voltage region and evaluated hit rates vs HV values, as
shown in Fig. 3.

Fig. 3. Hits per sec graph range of 4400V to 4900V at
north arm gap 0, panel 0, plane 0.
Fig. 3. shows the result of the scan up to 4900V. It is
obvious that the operation voltage should not be pushed over
4600V, because a plateau region is created from 4400V to
4600V.
The observed plateau runs up to 4550 - 4600V dependingon the HV chain. The results obtained thus far indicate that
the MUID can be operated at a higher voltage of +100V to+200V with a relatively small increase in the noise hit rates.
HV optimization is currently in progress.
Fig. 1. Efficiency drop with an increase in BBC novertex
rate. BBC is the beam luminosity monitoring device.
RIKEN Nishina Center
Ewha Womans University＊3
ENSICAEN＊1＊2

References

1) J. Murata et al.: Nucl.Instrum.Meth. A500 (2003)
2) W. Anderson et al.: Mar 2011. 51pp. arXiv:1103.4277- 101 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

PHENIX Run13 Local Polarimetry
M. Kim∗1,∗2 for the PHENIX collaboration∗1∗2

RIKEN Nishina Center
Department of Physics and Astronomy, Seoul National University- 102 -

−0.01−

χ2 / ndfχp0

132.9 / 11

−0.03851 ±± 0.00055−

Fill 17186
17186 Blue
Blue Beam
Beam e
eLR
Fill
LR

eeLR
LR

Fill 17169 Blue Beam eLReLR

One of the most important goals of the PHENIX
experiment at the Relativistic Heavy Ion Collider(RHIC) is to study the proton spin structure by measuring spin asymmetries during particle production.
The Run13 PHENIX experimentcollided longitudi√
nally polarized protons at s = 510 GeV. Helicity
asymmetry measurements of various probes from theexperiment are ongoing.
RHIC is capable of running polarized proton beams,
and each beam polarization P is measured by RHIC
polarimeters using left-right asymmetry in elastic scattering in the Coulomb Nuclear Interference (CNI) region. Since the stable beam polarization direction in
the RHIC rings is vertical, the beam polarization direction is kept vertical in RHIC except in experimental
halls. For each ring, Spin Rotators, which consist of superconducting helical dipole magnets, rotate the beampolarization direction the 90 degrees at the entrance
and the exit of the PHENIX experimental hall.
Since beam polarization may not purely be longitudinal at the experimental hall, we require measurements of transverse and longitudinal component of P(P⊥ , P� ) at the experimental hall, which is local polarimetry, as they introduce systematic error. Local
polarimetry is especially important in ALL measurements for studying gluon polarization in a proton since
ALL is very small, and P⊥ has potential to introduce
significant error.
PHENIX Local Polarimetry uses large transverse
single spin asymmetry (left-right asymmetry) AN offorward neutron production. Left-right asymmetry
originates from the interference between spin flip andnon-flip amplitudes. One Pion Exchange (OPE) models describe the production cross section of forward
neutron reasonably well, but the pion exchange amplitude is fully spin flip.1) Theoretical study is still ongoing.
PHENIX Local Polarimeter measures energies andtrajectories of forward neutrons. The local polarimeter consists of Zero Degree Calorimeters (ZDCs), andShower Max Detectors (SMDs). ZDC consists of W-Cu
alloys and PMMA (polymethyl methacrylate) based
optical fibers, and collects Cherenkov photons produced by charged secondary particles from neutron
showers. SMD is an X-Y plastic scintillator strip hodoscope. It is located between the 1st and 2nd ZDC
modules, where the approximate hadronic shower ismaximum. X-Y position of a neutron is reconstructedby using shower profile on SMD. Those detectors arelocated 1800 cm away from the collision point, and

0.003
0.003

p0
p0

0.002
0.002

−0.02
−

0.001
0.001

−0.03
−

0.001
− 0.0012 ndf
χ 2 // ndf

7.569 // 11
11
7.569

0.0003416 ± 0.0002509
0.0002509− 0.0003416

0
0
0.002
− 0.0020.003− 0.003

−0.04
−

0.004
− 0.004
−0.05
−

0.005
− 0.005
50

100

150

200
250
300
ZDC energy (GeV)−0.006
0.006

50
50

100
100

150
150

200
250
300
200
250
300
ZDC energy
energy (GeV)
(GeV)
ZDC

Fig. 1. Observed asymmetry in transverse fill (left), in longitudinal fill (right). The red lines are constant fittings.

cover 10 cm x 10 cm of a transverse plane at each zero
degree area.
The observed left-right asymmetry eN of forward
neutron production is defined as eN = P⊥ AEff
N , where
=
f
A
.
f
is
the
smearing
effect,correAEff
smear
N
smear
N
lated to the neutron energy-dependent position resolution1) . fsmear is assumed to be constant during theRun13 experiment.We measure AEff
N at transversely
polarized proton beam collisions, where P⊥ = P sothat it is measured by RHIC polarimeters. After that,
we measure eN with the local polarimeter to obtainP⊥ of longitudinally polarized beams.
Fig.1 shows eN plots. The left (right) plot shows eNof transversely (longitudinally) polarized proton beamcollisions.
PY PB
PY PB
As a final result, P⊥Y P⊥B is ∼ O(10−3 ) and P�Y P�Bis ≈ 0.999 in the Run13 experiment. The measured
double helicity asymmetry becomes≈
AMeasured
LL

1 1(P Y P B ALL + P⊥Y P⊥B AT T ) (1)PY PB � �

≈ 0.999ALL + O(10−3 )AT T(2)

where Y and B represent two colliding beams, and
AT T is the double transverse spin asymmetry. This
analysis suppressed the systematic error of AT T termto O(10−3 ). ALL measurements have been done up toO(10−4 ) so far2) , and O(10−3 )AT T is orders of magnitude smaller than 10−4 .3) Therefore, P⊥ does not significantly contribute to systematic error in ALL measurements in Run13.
References
1) A. Adare et al.: Phys. Rev. D 88, 032006 (2013)
2) A. Adare et al.:Phys. Rev. D 90, 012007 (2014)3) K. Boyle: AIP Conf. Proc. 915,335 (2007)

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Hadronic backgrounds pattern study
for W ± → µ± analysis in PHENIX
C. Kim,∗1,∗2 Y. Goto,∗2 S. Caussin,∗2,∗3 S. Han,∗2,∗4 M. Kim,∗2,∗5 T. Moon,∗2,∗6 T. Murakami,∗7 J. Murata,∗8
T. Nagashima,∗2,∗8 I. Nakagawa,∗2 S. Park,∗2,∗5 R. Seidl,∗2 W. Saito,∗2,∗8 K. Tanida,∗2,∗5 and I. Yoon∗2,∗5
The ongoing W ± → l± analysis at PHENIX aims
to precisely constrain the sea quark spin contribution
to the proton spin of 1/2. The main observable of thisanalysis is single longitudinal spin asymmetry amongmuons (AL ), which directly decayed from W boson1) .
To measure the desired asymmetry precisely S/BG
needs to be estimated as accurately as possible. However, observing a distinct Jacobian peak in W ± → µ±
is not expected due to the large momentum and charge
smearing in the muon reconstruction in addition todominant backgrounds from various sources. As a result, conventional S/BG estimation is not available;thus, we use a partially indirect method based on likelihood to the W (Wness), which is calculated by using
NLO level signal Monte Carlo (MC) and data itself.
In an actual S/BG estimation, we perform an unbinned maximum likelihood ﬁt (UMLF) by using six
probability density functions (PDFs) from a pair ofkinematic variables (η (pseudorapidity) and dw23 (reduced azimuthal bending)) and three processes (signal,
muonic BG, and hadronic BG).
Among these PDFs, the hadronic BG process ismodeled from the data itself owing to the diﬃcultyin hadronic MC production. To obtain the expected
hadronic distribution among the ﬁnal muon candidates, we modeled each kinematic variable’s distribution from the BG dominant region in the data (0.1 <Wness < 0.9), and then extrapolated it into the signal
dominant region (Wness > 0.9). For the validity ofthe method, each variable’s distribution along Wness
should be understood precisely. However, as there exists a serious Wness dependence of dw23 (Fig. 1) unlike η, a speciﬁc pattern study was required to reﬂect
its shape along Wness.
A typical dw23 in a certain Wness range (ex. 0.1 <Wness < 0.2) can be described by a stack of two Gaussians. To understand its development along Wness,
we collected dw23 over a certain Wness range, performed a ﬁt using two Gaussians, and then parameterized each Gaussian’s parameters (maximum, center,and FWHM) along Wness. Then we fed it back during
the hadronic BG dw23 modeling process as explained
above.
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Department of Physics, Korea University
RIKEN Nishina Center
Department of Physics, ENSICAEN
Department of Physics, Ewha Womans Univeristy
Department of Physics, Seoul National University
Department of Physics, Yonsei University
Department of Physics, Kyoto University
Department of Physics, Rikkyo University

Fig. 1. An example of dw23 vs. Wness.

Fig. 2. Comparison between fit results before (top) and after (bottom) the pattern study for W + → µ+ measured
in the North muon arm. The gray-hatched area of thesolid line indicates the uncertainty of the final PDF itself.

Figure 2 shows the results of a 2D UMLF projection onto dw23 in the ﬁnal sample before and after
the pattern study. A noticeable improvement was observed in the ﬁt’s χ2 , and we plan to apply the pattern
study in W ± → µ± analysis for both the 2012 and2013 datasets.
References
1) H. Oide et al: RIKEN Accel. Prog. Rep. 46 xviii- 103 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

W→ µ parity violating asymmetries from the 2013 running period in
the PHENIX experiment
R. Seidl∗1 for the PHENIX collaboration

Sampled range

σ(pp
(pp→
→W
W±±))×× BR(WBR(W→→ ll±±)) totalσtotal cross
cross section
section2013 :∫ Ldt = 277 pb≡

PYTHIA
CHE
STAR W→→e
PRD85 (2012) 092010
PHENIX W →→e
PRL 106 (2011) 062001-1.0 <
<η
η<
< 1.0
1.0
-1.0

-0.35 <
<η
η<
< 0.350.35-0.35

PHENIX W →
→µ

A
ALL

W+++Z
+Z→µ++,e,e++
Wµ
PeTeT >
> 30
30 GeVGeV
PTT>16>16 GeVGeV P
P
AeLeL (2009-2012)(2009-2012)
A
AµLL (2013)(2013)A
AeLeL (2013)(2013)A
NNPDFpol1.1
NNPDFpol1.1
GRSV STD
STD
GRSV
DSSV
DSSV
DNS KKP
KKPDNS
DNS Kretzer
Kretzer
DNS= 510
510 GeV
GeV
Run 13:13: p+p
p+p atat ss =
Run

0.5
0.5
0.0
0.0
-0.5
-0.5
-1.0
-1.0
1.0
1.0

-2 W
-1
-2
W--+Z
+Z→µ--,e,e-- -1

 



00




0.5
0.5

1113
22
STAR A
AeLeL(PRL(PRL1
113 (2014)(2014) 072301)
072301)STARη ++DSSV E
ETT>25>25 GeV
GeV
DSSV
ll

0.0
0.0
-0.5
-0.5
-1
Sampled Luminosity:
Luminosity: 277
277 pbpb-1
per armarm (2013)(2013)
Sampled
per

-1.0
-1.0

-2
-2

-1
-1

00

11

22

ηll--


 



1.1 <
< ||η
η|| <
< 2.5
2.5
1.1
50
50

100
100

150
150

200
200

250
250

300
300

±
±
σ
σ(pp
(pp→
→W
W±))×
× BR(WBR(W→→ ll±)) [pb][pb]References±

Fig. 1. Total pp → W X × BR(W → l) cross sections forforward muon and previously published W → e resultsby PHENIX1) and STAR2) as well as predictions by
Pythia3) , CHE4) and RHICBOS5) .

ables for signal and backgrounds candidate events werepre-selected by a likelihood ratio where only high signal likelihood events were kept. Then the relative signal and background contributions were fit by a maximum unbinned likelihood fit. From those preliminary
pp → W ± X cross sections were extracted which turned
out to be consistent with NLO predictions, see Fig. 1.
After correcting the raw single spin asymmetries for
∗1

1.0
1.0

Fig. 2. Single spin asymmetries of W+Z decay leptons as afunction of lepton rapidity. The preliminary PHENIX
electron and muon results from the 2013 data taking
period (red) and the published STAR electron resultsfrom 2012 (green)7) are shown as well as various helicity
parameterizations.

RHICBOS-1

beam polarization and dilution by background the preliminary results6) for the single spin asymmetries wereobtained as seen in Fig. 2. The results are in good
agreement with the parameterizations and will eventually be used in future iterations of the global helicity fits to all the existing deep inelastic scatteringand proton-proton collision data. The 2013 PHENIX
W results are currently being prepared for publicationand it is expected to reduce the systematic uncertainties which are dominated by the uncertainties on thesignal to background ratio still.

A
ALL

During the 2013 data taking period 277 pb−1 of longitudinally polarized proton collision data at a center of mass energy of 510 GeV were accumulated withan average beam polarization of 53% per beam at thePHENIX experiment at RHIC. This data corresponds
to the largest data sample available for the polarized
W data analysis. In order to access the sea quark polarization in the nucleon real W boson production isan elegant way. The parity violation of the weak interaction directly selects the helicity of the quarks andanti-quarks and the charge of the produced W boson
selects the quark and anti-quark flavors. For example
the W − gets produced by a left-handed d quark anda right-handed anti-u quark. While the u and d quark
helicities are already reasonably well known the sea
quark helicities are only very poorly determined andthe question whether the polarized light sea is symmetric or not has been predicted rather differently in various nucleon models. The analysis of W decay muonsin the forward and backward muon arm detectors of
PHENIX is not as straightforward as at central rapidities as there is no clean W decay signature such as a
Jacobian peak at half the W mass. Also a large numberof background sources exist such as heavy flavor decaymuons and hadrons decaying within the tracking volume mimicking a high momentum muon as previously
reported. With the help of kinematically different vari-

RIKEN Nishina Center- 104 -

1) A. Adare et al. [PHENIX Collaboration], Phys. Rev.
Lett. 106 (2011) 062001
2) L. Adamczyk et al. [STAR Collaboration], Phys. Rev.
D 85 (2012) 092010
3) T. Sjostrandet al. Comput. Phys. Commun. 135 (2001)
2384) D. de Florian and W. Vogelsang, Phys. Rev. D 81 (2010)
0940205) P. M. Nadolsky and C. P. Yuan, Nucl. Phys. B 666(2003) 31
6) F. Giordano [PHENIX Collabortion], to appear in JPCS
(Spin 2014 proceedings).
7) L. Adamczyk et al. [STAR Collaboration], Phys. Rev.
Lett. 113 (2014) 072301

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Neutral pion double helicity asymmetry†
K. Boyle∗1
π0

A LL

A major goal of the RHIC Spin program is to determine the gluon spin distribution in the proton. The
quark spin contribution to the proton spin (∆Σ) is only
about 25%1) , and so the remaining spin must be carried by the gluon spin (∆G), or by the gluon and quark
orbital angular momentum (Lq and Lg , respectively):

GRSV-std
pT Correlated Systematic Uncert.

0.01

0.005

†
∗1

Condensed from the article in Phys. Rev. D 90, no.
012007 (2014)
RIKEN BNL Research Center0-0.005

1,

Run5+6+9 Not Included:
4.8% Global Scaling Uncert.

-0.01

4.2x10 -4 Global Shift Uncert.
2

3

4

5

6

7

8

9

pT [GeV/c]

Fig. 1. Results for π 0 ALL vs. pT from the combined 2005,
2006 and 2009 PHENIX data sets. The data are compared with several theoretical expectations.

π0

A LL

(2)

where PB and PY are the polarizations of the two proton rings at RHIC, N is the yield of neutral pions,
π 0 , ++ and +− indicate same and opposite helicity
combinations of the two beam helicities, and R is therelative luminosity, defined as R = L++ /L+−, whichis required to normalize differences in the luminosity
L between RHIC proton bunches.
In 2009, RHIC PHENIX recorded 14 pb−1 with anaverage polarization of 56%. The π 0 ALL was measured, and found to be consistent with previous results.
The combined results from 20052), 20063) and 20094)
are plotted in Fig. 1. The systematic uncertainty from
relative luminosity in 2009 was larger than in previous
years, and for the lowest π 0 transverse momentum, pT ,was larger than the statistical uncertainties.
The combined data set are shown in Fig. 1 and Fig. 2
compared to several theoretical expectations based on
fits to the world polarized scattering data. In the caseof1) , the RHIC 2005 and 2006 π 0 data are also included. In fits that do not use RHIC data, such as
GRSV5) , LSS6) and BB7) , there is large uncertainty in∆G and therefore in the expected π 0 ALL . Fits including some RHIC data, such as DSSV1) and NNPDF8)
find a smaller range of possible ∆G. These data therefore offer significant constraint on ∆G. Recently, the
RHIC 2009 data have been included in an updated
version of DSSV9) , and indicate that the gluon spin
contribution to the proton spin is about the same sizeas that of the quarks.

Run5+6+9

0.015

1
1
= ∆Σ + ∆G + Lq + Lg
(1)
2
2
written in units of h̄.
At RHIC, ∆G can be probed directly through measurements of the double helicity asymmetry in polarized p + p collisions, in this case for neutral pions:
1 N++ − RN+−PB PY N++ + RN+−GRSV ∆ g(x) ≈ 0

0.02

Sp =

ALL =

DSSV08
0.025

NNPDF
0.025

BB10
LSS10

0.02

Run5+6+9
pT Corr. Syst. Uncert.

0.015

0.01

0.005

0

-0.005

-0.01
2

4

6

8

10

12

p [GeV/c]T

Fig. 2. Results for π 0 ALL vs. pT from the combined 2005,
2006 and 2009 PHENIX data sets. The data are compared with several theoretical expectations.

References
1) D. de Florian, R. Sassot, M. Stratmann and W. Vogelsang, Phys. Rev. D 80, 034030 (2009).
2) A. Adare et al. [PHENIX Collaboration], Phys. Rev. D
76, 051106 (2007).
3) A. Adare et al. [PHENIX Collaboration], Phys. Rev.
Lett. 103, 012003 (2009).
4) A. Adare et al. [PHENIX Collaboration], Phys. Rev. D
90, no. 1, 012007 (2014).
5) M. Gluck, E. Reya, M. Stratmann and W. Vogelsang,
Phys. Rev. D 63, 094005 (2001).
6) E. Leader, A. V. Sidorov and D. B. Stamenov, Phys.
Rev. D 82, 114018 (2010).
7) J. Blumlein and H. Bottcher, Nucl. Phys. B 841, 205(2010).
8) R. D. Ball et al. [The NNPDF Collaboration], Nucl.
Phys. B 874, 36 (2013).
9) D. de Florian, R. Sassot, M. Stratmann and W. Vogelsang, Phys. Rev. Lett. 113, 012001 (2014).

- 105 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics√
0Preliminary results of AπLL measurement at s = 510 GeV at
mid-rapidity through a PHENIX experiment
I. Yoon∗1,∗2 for the PHENIX collaboration
One of the important functions of the relativistic
heavy ion collider (RHIC) longitudinally polarized proton program is to constrain the gluon-spin component of the proton (∆G) by measuring the double
helicity asymmetry (ALL ) of π 0 and jet production.
Based on the results of deep inelastic scattering experiments, the quark-spin component of proton is only
0.330 ± 0.011(T heo.) ± 0.025(Exp.) ± 0.028(Evol.).1)
The remaining spin might be carried by gluons or orbital momentum. However, ∆G has not been measured in detail as yet.2)0π0The√ measurement of ALL for π production (ALL )at s = 200 GeV has been successfully published andhas contributed to constraining ∆G.3) To explore thelower Bjorken x region, where dominant uncertainty
remains, longitudinally polarized proton-proton collisions in 2013 (Run13) were√successfully carried out
s = 510 GeV.√Becausewith increased energy, i.e.
of the increased energy, the measurement at s = 510
GeV can reach a lower x range, 0.01 < x, while theprevious measurement
could reach only 0.02 < x. The√
measurement at s = 510 GeV is ongoing and preliminary results have been released.
0
AπLL can be defined in terms of differences in crosssections as
00

AπLL =

0

0

π
π
dσ++
− dσ+−d∆σ π=
π 0 + dσ π 0
dσ π0
dσ++
+−

(1)

where σ++(+−) stands for π 0 cross-section with the0same(opposite) helicity proton collisions. Because σ π
can be described by the parton distribution function,
the partonic reaction cross-section and fragmentation
function and most of π 0 s are from quark-gluon or
gluon-gluon scattering at mid-rapidity region, gluon
helicity distribution (∆g) is accessible by measuring
0
AπLL . This description is verified by comparing theπ 0 cross-section between theoretical and experimental
data.
Equation 1 can be rewritten in terms of experimental
observables as
ALL =1 N++ − RN+−L++,R =PB PY N++ + RN+−
L+−

(2)

where PB(Y ) is the polarization of RHIC’s “Blue (Yellow)” beam, N++(+−) is the yield of the π 0 candidatefrom the same (opposite) helicity collisions, and R is
the relative luminosity of the same and opposite helicity collisions.
∗1∗2

As the collision rate increases in Run13, the effect ofmultiple collisions on one beam crossing becomes sizable. The effect of multiple collisions is fully taken into
account for the relative luminosity measurement. Luminosity miscount by the finite resolution of the vertex
width of luminosity detector is also considered. The
uncertainty of the relative luminosity is a dominantsystematic uncertainty of the measurement.
To reduce the combinatorial background in diphoton invariant distribution, several cuts are applied.
Hits by a charged track, hadron, and previous crossings are rejected. To evaluate ALL for the remaining
background, ALL of the background is also measured
and is subtracted to obtain physical asymmetry.
0Fig. 1√shows preliminary results of AπLL measurement at s = 510 GeV. The result covers 2 GeV/c< PT√< 20 GeV/c (0.008 < xT < 0.08, where xT =2PT / s). The DSSV14 theory curve is shown andit agrees with experimental
data within uncertainty.
√
The measurement at s = 200 GeV is also shown forcomparison. Larger asymmetry is observed at higher
collision energy.

RIKEN Nishina Center
Seoul National University- 106 -√
0Fig. 1. Preliminary result of AπLL measurement at s =√0510 (red line) and comparison with AπLL at s = 200
GeV3) (blue line). DSSV14 theory curves2) are shown.
The grey and yellow bands indicate systematic uncertainty due to the uncertainty of relative luminosity.
Global-scale uncertainty due to systematic uncertaintyof polarization is not shown. Open boxes denote pointto-point systematic uncertainty.

Further analysis is ongoing to obtain the final result.
References
1) A. Airapetian et al.: Phys. Rev. D 75, 012007 (2007).
2) D. de Floran, R. Sassot, M. Stratmann and W. Vogelsang: Phys. Rev. Lett. 113. 012001 (2014).
3) A. Adare et al.: Phys. Rev. D 90, 012007 (2014).

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Cross section and asymmetry measurement of very forward neutral
particle production at RHIC
Y. Goto∗1 for the RHICf Collaboration
Although air shower observations at the surface ofthe earth have been carried out to understand the origin of the ultrahigh energy cosmic rays, these observations have uncertainties in the interpretation of theobserved data from the present phenomenological nuclear collision models. The LHCf experiment has been
performed at LHC for understanding cosmic ray generation from the collider experiment data1–3) . Precision
measurements of the very forward particle productionin the collider experiments improve the understandingof particle production processes in the nuclear collisions, and largely affect the interpretation of the observed data and the origin of the cosmic rays.
A large 10% single transverse-spin asymmetry(SSA) in neutron production from transversely polarized proton collisions was found at RHIC in 20024) .
This provides an important clue to study elementary
processes in air shower generation because the large
SSA indicates that there are dominant contributions
from processes that strongly interfere with each other.
Because the SSA measurement of neutron production
provides interference measurement with one pion exchange with a spin flip, it is sensitive to a mesonexchange without spin flip5) . Although the SSA ofvery forward neutrons at collision energies of 62 GeV,
200 GeV, and 500 GeV was measured at RHIC, thetransverse-momentum resolution of the data was limited.
We will perform a new collider experiment at RHIC,
the so called RHICf experiment, which uses a LHCf detector (which is called the RHICf detector) with a highresolution and wide coverage of transverse-momentum
measurements in order to improve the studies performed at RHIC and LHC. RHIC is a dedicated machine for QCD physics and it allows flexible operationto achieve our physics goals. In the RHICf experiment, we will have an improved transverse-momentum
resolution using the RHICf detector. The LHCf experiment has measured very forward neutral particle
cross section at collision energies of 0.9 TeV and 7 TeV.
We will obtain precision measurements of very forward
neutral particles (neutron, photon, neutral pion) at acollision energy of 510 GeV at RHIC. These data ofvarious collision energies will provide an understanding of air shower generation and the limitations in theorigin of the ultrahigh energy cosmic rays.
The RHICf detector will be located in front of the
Zero-Degree Calorimeter (ZDC) in the north side, 18m from the PHENIX collision point. In this area, allcharged particles are swept out by the last dipole mag∗1

RIKEN Nishina Center- 107 -

Fig. 1. Schematic view of the RHICf detector installationand the structure of the calorimeter.

net for colliding beams at RHIC, and only neutral particles are detected. The RHICf detector consists of
two sampling EM (electromagnetic) calorimeters with
44 interaction-length tungsten, 16 layers of scintillators, and 8 layers of silicon strip detectors; one with
25 mm × 25 mm and another with 32 mm × 32 mm
cross sectional area. The ZDC detector is a sampling
hadron calorimeter composed of Cu-W alloy absorbers
with PMMA (Polymethyl methacrylate)-based opticalfibers. The detection, identification, and energy measurement of photons and neutrons are performed using
EM and hadron calorimeters. A schematic view of the
RHICf detector installation and the structure of thecalorimeter are shown in Fig. 1.
We have proposed to perform a dedicated run for
1 week in 2016 with 510 GeV polarized proton collisions6) , and we are preparing for it. In the dedicated
RHICf run, we will use the normal accelerator condition of the RHIC, except the beta function value
at the PHENIX collision point, β ∗ = 10 m, in orderto obtain parallel beam collisions. We need 12 h toachieve sufficient luminosity for cross section measurements of photons, neutrons, and neutral pions including the transverse-momentum scan. The SSA can bemeasured with the same data set with higher statistics
than the measurements in the past.
References
1) O. Adriani et al., Phys. Lett. B 715, 298 (2012).
2) O. Adriani et al., Phys. Rev. D 86, 092001 (2012).
3) O. Adriani et al., Phys. Lett. B 703, 128 (2011).
4) Y. Fukao, M. Togawa et al., Phys. Lett. B 650, 325(2007).
5) B. Z. Kopeliovich, I. K. Potashnikova, I. Schmidt and
J. Soffer, Phys. Rev. D 84, 114012 (2011).
6) Y. Itow et al. [RHICf Collaboration], arXiv:1409.4860[physics.ins-det].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Fragmentation function measurements in Belle

Fragmentation functions allow us to study the process of nearly free partons fragmenting into final state
hadrons as they also exist in visible matter. While
the theory of the strong interaction, QCD, is generally accepted as the force governing all hadronic matter around us, only high energy processes are directly
calculable. Parton distribution functions as well as
fragmentation functions need to be obtained by experiment. Of particular interest is, how a parton of acertain flavor fragments into certain types of hadrons,
how initial parton spin gets translated into the distribution of final state hadrons and how transvserse
momentum is generated relative to the initial parton.
In the Belle experiment one can study these aspects
well since the underlying process of electron-positronannihilation provides a clean initial state without any
hadrons to study the emerging final state hadrons.
However, normally the quark flavor is not directly accessible as both a quark and an antiquark are created
and at least for light flavors (u, d and s quarks) tagging
techniques are not reliable. A first way around thislimitation was already performed in the Collins typeanalysis1) where two charged pions in opposite hemispheres were studied. Having two hadrons in opposite
hemispheres mostly ensures, that one hadron was fragmentating from the quark and another from the antiquark. The ratio of same over opposite charges thenrevealed the differences of favored and disfavored polarized and un-polarized fragmenation functions. Thismethod was extended for pion-kaon and kaon-kaon
combinations to obtain sensitivity of the strange quark
Collins functions as well as disfavored u,d quark tokaon Collins fragmentation functions. Preliminary results have been obtained in 20142) as shown in Fig. 1
and are expected to be published soon.
Furthermore the unpolarized fragmentation funch
tions D1,q(z, s) can be studied in a similar way andfirst results have been prepared for all combinations ofcharged pions and kaons either in opposite hemispheres√or also the same for comparison. Here, z = 2Eh / s
is the fractional energy the √hadron h carries relative
to the initial parton q and s is the center of massenergy. In the thus obtained cross sections as a function of fractional energy z the ratios between sameand opposite sign pion pairs in opposite hemispheres
essentially provide the ratio of dis-favored over favored
∗1
∗2
∗3
∗4
∗5
∗6

RIKEN Nishina Center
Physics department, University of Illinois
Physics department, University of Indiana
Department of Physics, Tokyo Institute of Technology
Department of Physics, University of the Basque Country
Ikerbasque- 108 -A0

R. Seidl,∗1 F. Giordano,∗2 M. Leitgab,∗2 A. Vossen,∗3 H. Li,∗3 W. Jacobs,∗3 N. Kobayashi,∗4
M. Grosse-Perdekamp,∗2 A. Ogawa,∗1 C. Hulse∗5 and G. Schnell∗5,∗6

0.06

Unlike/Like ≠π≠π
Unlike/Like ≠πK
Unlike/Like KK

0.2 ʺ≤ z1 < 0.25

0.25 ʺ≤ z1 < 0.3

Belle Preliminary

0.04

0.02

0

-0.02

0.06
0.3 ʺ≤ z1 < 0.42

0.42 ʺ≤ z1 < 1

0.04

0.02

0

-0.02
0.2

0.25

0.3

0.35

0.4

0.45

0.5

0.55

z2

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0.55

z2

Fig. 1. Collins type azimuthal moments as a fucntion of
fractional energy z2 in bins of fractional energy z1 for
opposite sign over same sign pion pairs (blue), πK(green) and kaon pairs (purple).

fragmentation from u,d quarks to pions. Favored fragmentation relates to fragmentation into a hadron withvalence content the same as the initial parton (ie uto π + = |ud⟩) and dis-favored fragmentation with valence content not the same (ie d to π + ). First results
have been obtained and are expected to be shown as
preliminary results and be published soon. The expected precision is such, that even the ratios at fractional hadron energies z above 0.8 have still reasonably
small uncertainties.
In addition an analysis of transverse momenta of one
hadron relative to a second hadron is ongoing whichshould help improve the rather large uncertainties andassumptions of any transvserse momentum dependent
distribution and fragmentation functions. These areneeded for the analysis of quark transversity and Sivers
function data of semi-inclusive deep inelastic scattering and hadron collision experiments. These explicit
transvserse momentum dependent measurements arealso expected to obtain preliminary status this year.
References
1) R. Seidl et al. [Belle Collaboration], Phys. Rev. Lett.
96, 232002 (2006). R. Seidl et al. [Belle Collaboration],
Phys. Rev. D 78, 032011 (2008), [Erratum-ibid. D 86,
039905 (2012)]. A. Vossen et al. [Belle Collaboration],
Phys. Rev. Lett. 107, 072004 (2011).
2) F. Giordano [Belle Collaboration], PoS DIS 2014, 212(2014).

Ⅱ-4. Hadron Physics

√RIKEN Accel. Prog. Rep. 48 (2015)

Measurement of direct photon azimuthal anisotropy insN N =200GeV Au+Au collisions in RHIC-PHENIX experiment
S. Mizuno∗1,∗2 for the PHENIX collaboration

High-energy heavy-ion collision experiments havebeen carried out since 2000 at the Relativistic Heavy
Ion Collider (RHIC), to study the properties of quarkgluon plasma (QGP). Direct photons are deﬁned as all
photons except for those coming from hadron decays.
Photons do not strongly interact with the medium.
Furthermore, they are emitted from various sources,
such as initial hard scattering, jet fragmentation, andthermal radiation, during all stages of collisions. Thus,
direct photon is a powerful tool to study QGP.
Direct photon pT spectra have been measured via
a calorimeter method1) , virtual photon method2) , andconversion photon method3) . It is found that the pT
spectra of Au+Au collisions include an additional exponential pT spectra compared to those of p+p collisions scaled by the number of binary collisions. The
eﬀective temperature is obtained from the inverse slopeof the exponential pT spectra, it is approximately 240
MeV. It is found that photons mainly originate from avery hot medium in the early stage of collisions, since
the kinetic freeze-out temperature obtained is approximately 100 MeV.
Azimuthal anisotropy is deﬁned as the relative amplitude of anisotropic azimuthal distribution with respect to the event plane. To quantify the anisotropy,
Fourier series is used for the azimuthal distribution of
the number of emitted particles.
∑
dN/dϕ = N0 [1 +2vn cos {n(ϕ − Ψn )}],
(1)
vn = ⟨cos {n(ϕ − Ψn }⟩,∗2

Fig. 1. (Left) v2 as a function of pT of a neutral pion (black)and inclusive photon (red). (Right) v2 as a function of
pT of a direct photon4) .

There is a discrepancy called “photon puzzle”.
There are no models to explain both the results simultaneously. In order to constrain the photon production
mechanism, the third-order azimuthal anisotropy v3 ismeasured. Figure 2 shows direct photon v3 for pT < 4
GeV/c. It is found that the strength of direct photon
v3 is comparable to that of hadron v3 . It shows a similar trend to direct photon v2 . It can be interpreted
that photons emitted in the late stage of collisions are
dominant in the low pT region. These results would be
helpful for understanding the photon puzzle.

(2)

where ϕ is the azimuthal angle of photons, and vn
and Ψn are the strength and event plane of thenth -order harmonic azimuthal anisotropy, respectively.
The mechanism of azimuthal anisotropy has been studied, and it is understood that it strongly depends on
the initial geometry shape. The photon emission angle is expected to depend on the photon sources andinitial geometry of the participant shape: thermal photons have v2 > 0, photons fragmented from a jet havev2 > 0, and prompt photons have zero v2 ,. Direct photon v2 is measured4) to identify the photon sources.
It is found that the strength of direct photon v2 ataround 2 GeV/c is comparable to that of hadron v2 .
Because photons are emitted during all stages of collisions, emitted photons should include photons emitted
from the medium, which is not yet expanded. This is
why direct photon v2 was predicted to be smaller thanhadron v2 in many theoretical models. Since a photon∗1

has large v2 , the results suggest that photons in the
low pT region are mainly generated from in the latestage of collisions.

University of Tsukuba
RIKEN Nishina Center- 109 -

Fig. 2. v3 as a function of pT of a neutral pion (red) anddirect photon (black) by 20% centrality steps from 0 to60%.

References
1) S.S. Adler et al.: P.R.L. 94, 232301 (2005)
2) A. Adare et al.: P.R.L. 104, 132301 (2010)3) A. Adare et al.: arXiv:1405.3940 [nucl-ex] (2014)
4) A. Adare et al.: P.R.L. 109, 122302 (2012)

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Charged hadron elliptic and triangular flow in Cu+Au at√
sN N = 200GeV
H.Nakagomi∗1,∗2 for the PHENIX collaboration
Quark-gluon-plasma(QGP) is considered to be a hot
and dense nuclear matter which is a phase of matter in quantum chromodynamics. A QGP was createdby colliding nuclei at the Relativistic Heavy Ion Collider(RHIC) .
One of the strong evidence to prove the formationof QGP is that the low momentum particle production is anisotropic. Azimuthal anisotropy originatesfrom initial spatial geometry. For low momentum particles, anisotropic collective ﬂow is considered to result
from the hydrodynamic expansion of QGP. Further thestrength of azimuthal anisotropic ﬂow has been used todetermine the speciﬁc viscosity over entropy ratio(η/s)
of QGP and the initial spatial condition by comparing it with the theoretical model. Thus measuring theazimuthal anisotropic ﬂow is a good method to investigate the bulk property of QGP and the space time
expansion mechanism.
The produced particle distribution is expressed as a
Fourier expansion series as follows∑dN∝1+
2vn cos(n(ϕ − Ψn ))
(1)
dϕ
n=1
where vn = ⟨cos(n(ϕ − Ψn ))⟩ n(1,2,3,4,,,) corresponds
to the strength of anisotropic ﬂow, ϕ is the azimuthal
angle of the produced particle, Ψn is the nth order
event plane that is the average of all emitted particles
angles. So far the 2nd order ﬂow harmonic v2 whichis called elliptic ﬂow has been studied in symmetricsystems such as Au+Au, the 3rd order ﬂow harmonicv3 which is called triangular ﬂow was not predicted
to exist because initial geometry was considered to besymmetric. However recently, a large v3 was measured
at RHIC. The v3 is assumed to have originated fromthe initial spatial ﬂuctuation.
In 2012, a Cu+Au collision was performed at RHIC.
In Cu+Au collisions, the initial spatial geometry isasymmetric. The pressure gradient is predicted to be
diﬀerent for the Au and Cu sides. Thus the diﬀerent
expansion at the Au and Cu sides will lead to the asymmetric emission of particles. The vn in the Cu+Au collision could help determine η/s and the initial spatialcondition.
Figure 1 ilustrates the Npart dependence of v2 andv3 for three collision systems. The system size dependence of v2 is clearly seen. The v2 values in Cu+Au
collisions are between those in Au+Au and Cu+Cu
data sets and v2 in all systems increases as Npart decreases, the diﬀerence of v2 values between the diﬀerent∗1∗2

RIKEN Nishina Center
Graduate School of Pure and Applied Sciences
University of Tsukuba- 110 -

systems reduce with a decreasing Npart . The Npart dependencies of v2 and v3 could be expected from those of
2nd and 3rd order initial spatial anisotropies(ϵ2 and ϵ3 ).
The ϵ2 and ϵ3 are calculated using a Glauber Monte
Carlo simulation. Figure 2 ilustrates comparison between v2 and v3 as a function of pT with event-byevent hydrodynamical calculation with η/s for 20-30% centrality bin. In this hydrodynamical calculation,
Glauber Monte Carlo simulations are employed as theinitial spatial condition and 4π/s = 1 or 4π/s = 2 isused. The hydrodynamical calculation with 4π/s = 1
has better agreement with v2 and v3 at low pT than
4π/s = 2, whereas at high pT hydrodynamical calculation with 4π/s = 2 has better agreement with v2 andv3 than 4π/s = 1.

Fig. 1. Comparison of v2 and v3 as a function of Npart for
four centrality bins in Au+Au, Cu+Cu and Cu+Au

Fig. 2. v2 and v3 as a function of pT for 20-30% centralitybin. Comparison of PHENIX experimental data points
and hydrodynamical calculation

References
1) A. Adare et al (PHENIX Collaboration), Phys. Rev.
Lett. 107 252301 (2011)2) M. R. Haque, M. Nasim, B. Mohanty, Phys. Rev. C 84,
067901 (2011)3) Bozek Phys. Lett. B717, 287(2012)

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Commissioning and operation of silicon vertex detector for PHENIX
experiment in RHIC Run-14
M. Kurosawa,∗1 Y. Akiba,∗1 H. Asano,∗2 J. Bryshawskyj,∗3 T. Hachiya,∗1 M. Lentz,∗4
B. Miljko,∗5 T. Moon,∗1 H. Nakagomi,∗6 R. Nouicer,∗4 C. Pancake,∗7 P. Stankus,∗5
T. Sumita,∗1 A. Taketani,∗1 M. Wysocki,∗5 and the PHENIX VTX group
The PHENIX experiment aims to elucidate the spin
structure of nucleons and the property of the hot anddense matter at the Relativistic Heavy Ion Collider(RHIC). A silicon vertex detector (VTX) was successfully installed in 2010 as a key element in the spin and,hot and dense matter physics. The VTX comprises afour-layer barrel detector built from two inner silicon
pixel detectors and two outer silicon strip detectors.
As mentioned in our previous report, the silicon pixel
detectors were repaired and the active area of VTX
was improved from 60% to 90% before Run-141) . This
report presents the results of the commissioning andthe performance of silicon pixel detectors in Run-14.
The silicon sensor module is an assembly of a silicon pixel sensor and four readout chips bump-bonded
to the sensor with soldering bumps. Most of the deadarea 10% results from the defects of soldering bumps
caused by a thermal stress during operation. The pixel
response at the boundary between the active and thedead areas is unstable, and those pixels become noisy
because they have high resistivity caused by a weekelectrical connection. The main tasks in the commissioning stage are the determination of the thresholdlevel and mask of noise pixels for all readout chips forminimizing fake hits.
Figure 1 shows the threshold dependence of a hit
event rate for a readout chip. The threshold is represented as a DAC value. The higher the DAC value, thelower the number of electrons. The average of the optimized threshold for all readout chips was 180, whichcorrespons to 3,700 electrons. The average was substantially low compared with that for the 14,000 electrons of Minimum Ionizing Particle (MIP).
Pedestal data was taken with a random trigger todetect noise pixels. The location of noise pixels were
determined by detecting pixels that have a high hit
rate. Since the noise level is dependent on the threshold level, a threshold and noise scan were iterated several times. Figure 1 shows the plot after removing
pixels that have high hit rate. Approximately 0.03%
of all pixels were masked and the probability of thenoise-hit per event was reduced to 10−5 .
Figure 2 illustrates a performance plot that shows
∗1
∗2
∗3
∗4
∗5
∗6
∗7

RIKEN Nishina Center
Department of Physics, Kyoto Univ.
Department of Physics, City Univ. of New YorkBrookhaven National Laboratory
Oak Ridge National Laboratory
Department of Physics, Tsukuba Univ.
Department of Physics, Stony Brook University

Fig. 1. Relationship between the threshold and thecount/total event.

the correlation of the z vertex between beam-beamcounter (BBC) and VTX. The BBC is a Cherenkov
counter and determines the z vertex with a precisionof 5 mm. The position resolution of VTX is less than
80 µm at over 1 GeV/c2) . The width of the plot depends on the resolution of the BBC.

Fig. 2. Scatter plot of the z vertex position for BBC and
VTX.

The 200 GeV Au+Au collision run was started in
March and it ended in the middle of June. The VTX
took about 20 billion events of physics data keeping theactive area of 90% without any serious issues during
this period.
References
1) M. Kurosawa et al.: RIKEN Accel. Prog. Rep. 47, 228(2013)
2) T. Moon et al.: In this report.

- 111 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Alignment of the PHENIX Silicon Vertex Tracker (VTX) in the 2014
RUN
T. Moon,∗1,∗2 A. Adare,∗3 Y. Akiba,∗1 H. Asano,∗1,∗4 S. Bathe,∗1 J. Bryslawskyj,∗5 T. Koblesky,∗3
T. Hachiya,∗1 M. Kurosawa,∗1 D. Mcglinchey,∗3 H. Nakagomi,∗1,∗6 R. Nouicer,∗1 T. Rinn,∗7 Z. Rowan,∗5
T. Sumita,∗1 A. Taketani,∗1 and the PHENIX VTX group

∗1
∗2
∗3
∗4
∗5
∗6
∗7

RIKEN Nishina Center
Department of Physics, Yonsei University
Department of Physics, University of Colorado, Boulder
Department of Physics, Kyoto University
Department of Physics, Baruch Colleage, CUNY
Department of Physics, Univ. of Tsukuba
Department of Physics, Iowa State University

×103

×103
140

350

120

300

100

250

80

200

60

100

0.0 < pT < 0.5 GeV/c

20
0

180

150

σDCA2D = 130 µm

40

-0.04

-0.02

0

50
0.02

0

0.04

DCA2D [cm]σDCA2D = 87 µm
0.5 < pT < 1.0 GeV/c
-0.04

-0.02

0

0.02

DCA2D [cm]

0.04

0.02

DCA2D [cm]

×103
60000

160
140

50000

120
40000

100

30000

80
60
40
20
0

σDCA2D = 68 µm

20000

1.0 < pT < 1.5 GeV/c
-0.04

-0.02

0

10000

0.02

0

0.04

DCA2D [cm]σDCA2D = 60 µm
1.5 < pT < 2.0 GeV/c
-0.04

-0.02

0

0.04

Fig. 1. DCA distributions in X-Y plane as a pT after thealignment
σDCA2D ( pT )σDCA2D [µm]During the 2014 run, PHENIX has recorded a large
number (∼20B) of events with the PHENIX silicon vertex tracker (VTX)1),2) and the Foward VTX (FVTX)
combined. This dataset is also the best quality datasetof VTX since it was installed in 2011.
The VTX is located close to the interaction point of
the two incoming particles. It consists of four coaxial
cylindrical layers, with radii between 2.63 and 16.69
cm, covering the pseudo-rapidity range |η| < 1.2 andazimuthal angle ∆φ ∼ 2π. The two innermost layers
consist of silicon pixel sensors, and the two outermost
layers are made of silicon strip-pixel sensors.
The VTX is designed to reconstruct primary andsecondary vertices with a resolution better than 100µm
for pT > 1GeV/c as well as to significantly improve
tracking performance in conjunction with other detectors, particulary the drift chamber (DC). The VTX,
thus, is necessary for charm and bottom separation,and for direct measurement of D0 meson using a distance of closest approach (DCA) of the reconstructed
track from the primary vertex position.
In reality, the actual installed detector position cannot be measured by our high-precision surveys. Thus
there exists a relatively large mis-alignment that will
significantly degrade the resolution of the measurement.
Alternatively, the mis-alignment can be improved
through the track-to-hit based alignment via software.
The ideal geometry of the VTX for pixel and strippixel is first known by measurements of sensor positions in surveys and the design positions, respectively.
The position of (hits on) the sensor is represented ina VTX coordinate system. On the other hand, thetrack for the alignmemt is reconstructed by the DC ina global (DC) reference coordinate system regardlessof the VTX, and it is projected to the primary vertex. The relative postion between the VTX and the
DC is determined by measuring a beam center in eachcoordinate system and then (hits on) the sensor, andthe track projection is represented in the global reference coordinate system. Residual (distance between
the tracks and the measured hit on the sensor plane) isused to evaluate the mis-alignment in the VTX geome-

140

120

100

80

60

40
0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

pT [GeV/c]

Fig. 2. Resolution of DCA in X-Y plane as a function ofpT after the alignment

try as input for the next iteration. The mis-alignmentis minimized as the residual becomes 0. This procedure
is iterated until convergence is reached.
The VTX alignment in the 2014 run has been successfully completed as stated above. The final results
are shown in Fig. 1 and Fig. 2, which indicate DCA
distributions and resolution as a function of pT in XY plane after the alignment. It should be noted that
deterioration of the resolution in the low pT region(pT < 1GeV/c) is attributed mainly to backgrounds
and multiple scattering.
We have achieved DCA resoultion of < 70µm for
1GeV/c of pT , which enables precise investigation ofcharm and bottom physics in both the p + p and
Au+Au collision systems with the PHENIX detector
at RHIC.
References
1) A. Taketani et al. [PHENIX Collaboration], Nucl. Instrum. Meth. A. 623, 374, (2010).
2) T. Hachiya et al.: RIKEN Accel. Prog. Rep. 44, 179(2011).

- 112 -

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Distance of closest approach analysis with VTX at RHIC-PHENIX
H. Asano,∗1,∗2 A. Adare,∗3 Y. Akiba,∗2 S. Bathe,∗4,∗2 J. Bryslawskyj,∗4 T. Hachiya,∗2 T. Koblesky,∗3
M. Kurosawa,∗2 D. McGlinchey,∗3 T. Moon,∗7,∗2 H. Nakagomi,∗10,∗2 R. Nouicer,∗11,∗2 T. Rinn∗8 Z. Rowan,∗4
T. Sumita,∗2 A. Taketani,∗2 and the PHENIX VTX group
Heavy quark production is being studied via a
PHENIX experiment by measuring of electrons fromsemi-leptonic decays of hadrons containing charm andbottom quarks. A large suppression and strong elliptic
flow of single electron heavy
flavor has been observed√in Au+Au collisions at s = 200 GeV1) . In past measurement, PHENIX was unable to distinguish electrons
from charm and bottom quarks.
In order to understand the medium effects in moredetail, the Silicon Vertex Tracker (VTX) was developed and installed in year 2011 in the RHIC-PHENIX
experiment. The VTX can measure charms and bottoms separately using the distance of closest approach(DCA) to the primary vertex. After the preliminary result of the fraction of b → e/(b → e+c → e) in Au+Au
collision was reported2) , we improved the DCA analysis to obtain the final result.
(i) In the high multiplicity environment, hits on the
VTX can be associated with uncorrelated tracks.
They are one of the main sources of backgroundof DCA distribution. We studied the chi-square
distribution of track fitting using real data anda Monte Carlo simulation. We determined thethreshold of the chi-square value of tracks to reject random association candidates as much as
possible. The real tracks are expected to be removed around 5% from the simulation study.
(ii) Electrons from photon conversion and Dalitz decay of neutral mesons are also the backgroundsource in the electron DCA measurement. We
identify e+ , e− pairs by VTX and removed thesepairs from the DCA distribution. The tagging
efficiency of the conversion and the Dalitz decay are estimated thorough the simulation. The
yield of the remaining electrons and the shapeof the DCA distribution from conversions andDalitz decays are also estimated using the pastmeasurement data1) and the simulation.
(iii) Electrons from J/ψ and Kaon also cause small
background noise. The yield of these electrons
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Department of Physics, Kyoto University
RIKEN Nishina Center
Department of Physics, University of Colorado Boulder
Department of Physics, City University of New York
Department of Physics, Yonsei University
Graduate School of Pure and Applied Sciences, Universityof Tsukuba
Brookhaven National Laboratory
Department of Physics and Astronomy, Iowa State University- 113 -and the shape of DCA distribution are estimatedusing the past measurement data and the simulation.
After completing the study, we decomposed electron
DCA distribution. In Fig. 1, the shape of each component is obtained through the simulation and each component is overlaid on the DCA distribution of real data.
Currently, the ratio of charm and bottom quarks are
based on theoretical prediction. The fraction of each
DCA background (conversion, Dalitz, Kaon, J/ψ...) is
obtained from (ii) and (iii). The sum of those DCA
distribution values describes the shape of the electron
DCA distribution in real data very well.
To obtain the precise ratio of b → e/(b → e + c → e)
as a function of transverse momentum and momentum
distribution of parent mesons (D and B mesons) from
DCA measurement, an invariant yield of heavy flavor
electrons and DCA distribution are being analyzed simultaneously. The results will be published soon.
2.00 < p < 2.50
T

Data
Charm
BottomRandomHadron Contamination
DalitzConversion
Ke3
J/ ψ
Sum

103

102

10

1

10-1
-0.15

-0.1

-0.05

0

0.05

0.1

0.15

c*DCA2d [cm]Fig. 1. Electron DCA distribution at 2.0-2.5 GeV/c.
Charm (blue) and bottom (yellow) are signal. The
other components are backgrounds. The sum of thesignals and backgrounds (light blue) obtained throughthe simulation is consistent with data (black).

References
1) A. Adare et al. Phys.Rev., C84:044905, (2011).
2) R. Nouicer et al. Nucl.Phys., A904-905 (2013) 647c-652c

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Current status of bottom and charm measurements using VTX at
RHIC-PHENIX
T. Hachiya,∗1 A. Adare,∗2 Y. Akiba,∗1 H. Asano,∗1,∗3 S. Bathe,∗1,∗4 J. Bryslawskeyj,∗4 T. Koblesky,∗2
M. Kurosawa,∗1 D. Mcglinchey,∗1 T. Moon,∗1,∗5 H. Nakagomi,∗1,∗6 R. Nouicer,∗7 T. Rinn,∗8 Z. Rowan,∗4
T. Sumita,∗1 and A. Taketani∗1(1) Rejecting photon conversions and Dalitz decays:
Photon conversions and Dalitz decays of lightneutral mesons are the main background sourcesin single electron measurement. Electron pairs
from the backgrounds are generated with small
opening angles and the pair makes correlated
hits in VTX. Therefore, VTX can signiﬁcantly
reject the backgrounds by requiring pair-wise
hits in VTX. On the other hand, heavy ﬂavor
electrons (b → e and c → e) rarely make thecorrelated hits. Figure 1 shows the fraction ofheavy ﬂavor electrons to inclusive electrons. The
open and closed circles correspond to the result
before and after VTX installation, respectively.
This plot indicates that VTX could reject thebackground eﬀectively and provide a good signal to noise ratio.
(2) Unfolding of DCA distribution:
We developed an unfolding method to decompose bottom and charm contributions3) . The
method is a Bayesian approach using the Markov
chain Monte Carlo sampler4) .
Using thismethod, the bottom and charm yields are obtained by ﬁtting both the DCA and the pT distribution of heavy ﬂavor electrons simultaneously.
The DCA shape is correlated with the pT distri∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

bution of the parent B and D mesons because
the DCA is determined by the convolution of
two eﬀects: the decay length of the parent particle and the decay pT kick relative to the parent
momentum. As a consistency test, we veriﬁed if
the known input can be reproduced using a simulation3) .
(3) Detector eﬃciency:
The detector eﬃciency was determined by full
GEANT simulation with the actual dead map.
The raw pT spectrum of heavy ﬂavor electrons
was corrected using the eﬃciency, and the corrected spectrum is consistent with the publisheddata5)(4) DCA smearing by random association
The DCA shape is smeared and modiﬁed by the
random association of electron tracks with VTX.
The smearing eﬀect was studied by embedding
simulated electron tracks into real events. Then,
we found that the unphysically large DCA tailin the data was explained by the smearing eﬀect.
The current analysis of Au+Au data will be completed for publication soon. We took 20 billion Au+Au
data in year 2014, which is 20 times larger statistics.
This new dataset will be analyzed. The alignment calibration of the dataset was completed6) and the data
production was started.
Fraction of HFe to inclusive electrons

One of the most noteworthy results at RHIC was thestrong suppression of inclusive open heavy quarks (bottoms and charms) at high pT in central Au+Au collisions1) . It was expected that heavy quarks would beless suppressed due to their large mass. However, theresults showed that the suppression was comparablystrong with pions. In order to study the suppression indetail, we developed a silicon vertex tracker (VTX) at
PHENIX. VTX can measure bottoms and charms separately using the distance of closest approach (DCA)
to the primary vertex.
We reported the preliminary result of the fractionof (b → e)/(b → e + c → e) using VTX in Au+Au
collisions2) . Numerous improvements of the analysis
for the ﬁnal result are underway. Here, we have listed
a few of these improvements:

1
0.9
0.8
0.7
0.6
0.5
0.4
0.3

After VTX installation

0.2

Before VTX installation

0.1
0
0

0.5

1

1.5

2

2.5

3

3.5

4

4.5
5
p (GeV/c)T

Fig. 1. Fraction of heavy flavor electrons to inclusive electrons before (closed) and after (open) the VTX installation.

References
1) A. Adare et al: Phy. Rev. Lett. 98, 172301 (2007).
2) R. Akimoto et al.: RIKEN Accel. Prog. Rep. 46, 60(2013).
3) A. Adare et al.: Quark Matter 2014 poster.
4) G. Choudalakis.: arXiv:1201.4612v4
5) H. Asano at al.: In this report.
6) T. Moon at al.: In this report.

RIKEN Nishina Center
Department of Physics, University of Colorado, Boulder
Department of Physics, Kyoto University
Department of Natural Science, Baruch College, CUNY
Department of Physics, Yonsei University
Department of Physics, University of Tsukuba
Brookhaven National Laboratory
Department of Physics, Iowa State University- 114 -

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Development of the FVTX high multiplicity trigger system for the
PHENIX experiment
T. Nagashima,∗1,∗2 Y. Fukushima,∗1,∗2 S. Hasegawa,∗3 I. Nakagawa,∗1 W. Saito,∗1,∗2
and the PHENIX FVTX group
Protons and neutrons, which are the components offamiliar substances, are composed of quarks and gluons that bind quarks together. Immediately following
the big bang, under extremely high-density and hightemperature conditions, quarks and gluons are considered to escape from the boundary of nucleons. Thisliquid-like state is called Quark Gluon Plasma (QGP).
The PHENIX group investigates the behavior ofmatter in such a high-density and high-temperaturestate produced by collision using Relativistic Heavy
Ion Collider (RHIC). In particular, in Au+Au and
Pb+Pb collisions, the particle angular correlation exhibits a similar azimuthal pattern throughout the wide
range of the rapidity region, referred to as “ ridge. ”
The ridge correlation is considered as a consequenceof the hydrodynamic ﬂow of products, and it is interpreted as a characteristic of QGP. Certain experiments
at the LHC have recently reported that the ridge wasobserved especially in high-multiplicity events in small
colliding systems, such as p+p.1) Similar ridge phenomena were observed in d+Au and He3+Au at RHIC.
However, they have not yet been observed in p+p.
Previous experiments demonstrated high-multiplicity
events are the key to observe the ridge in p+p collisions. In PHENIX, the Forward Silicon Vertex Detector (FVTX) is suitable to select such high-multiplicity
events since it is the tracker closest to the vertex point.
The FVTX trigger design is shown in Fig. 1. The
trigger signal is generated on FPGAs implemented
on FVTX readout electronics,2) Front End Module(FEM) and FEM Interface Board (FEM-IB). Using thefeature that each FEM corresponds to an azimuthal
slice of the FVTX sensor, each FEM judges whether
there is any track, following which the FEM-IB counts

Fig. 1. FVTX trigger design based on the FPGA logic
implemented on the readout electronics
∗1
∗2
∗3

the number of track ﬂag sent from the FEM, and ﬁnally the FVTX trigger ﬁres when the number of track
is greater than that of our interest.

Fig. 2. Correlation between the number of hits and thetrigger state

The trigger algorithm in the FEM FPGA was tested
through evaluation of the process eﬃciency depending on the number of hits on the detector. The hits
were generated by using a calibration pulse that injects typically 13 strips per detector per event. Fig.
2 shows the correlation between the number of hits
per event measured from oﬄine data analysis and thetrigger state; the vertical axis shows the trigger ﬂag
at an FEM that is supposed to give 1 for the events
where the number of hits is greater than the threshold.
The eﬃciency, deﬁned as the number of trigger events
divided by the number of events with more hits than
the trigger threshold, was 94%, and a few fake triggers
were observed.
New serial line cables for FEM - FEM-IB communication were installed in the trigger system, and theirsignal transmission test was performed. Performance
was monitored by scanning the signal rate, and the cables exhibited good performance up to a trigger rate of
4.7 MHz. The timing of the trigger signal was tuned
with GL1. It was found that GL1 does not recognize
the trigger signal depending on timing. It is adjusted
using the BBC trigger signal, which is already used asa trigger.
References
1) V. Khachatryan et al.: CMS Collaboration, JHEP

1009 (2010) 091
2) arXiv:1311.3594v2 [physics.ins-det] 14 Feb. 2014

RIKEN Nishina Center
Department of Physics, Rikkyo University
J-Parc- 115 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Study of direct photon polarization to shed on strong magnetic fieldin heavy ion collisions at PHENIX†
T. Hoshino∗1,∗2
A strong magnetic ﬁeld is expected to be createdin non-central heavy-ion collisions. This ﬁeld is created by the eﬀect of both of the collision participants
and spectators. The ﬁeld direction is perpendicular
to the collision reaction plane. The magnitude of theﬁeld created in the collisions at BNL-RHIC top energy is estimated to reach as high as 1014 teslas. If
the magnitude of the magnetic ﬁeld in heavy-ion collisions is compared with the QED critical magnetic ﬁeld
(Bc = m2e /e = 4×109 teslas) and the surface of magnetars (1011 teslas), the ﬁeld magnitude is much higher inheavy ion collisions. The ﬁeld magnitude is decreased
rapidly but keeps the magnitude above the critical ﬁeldof an electron for about 3 fm/c.
Creation of a strong magnetic ﬁeld in heavy ion collisions was ﬁrst expected in 19761) . The strong magnetic ﬁeld in heavy ion collisions has recently attracted
the interest of researchers in theories and experiments
in recent years for the following reasons. First, themagnetic ﬁeld can reach beyond the critical ﬁeld andinteresting phenomena such as Chiral magnetic eﬀects
and non-linear QED eﬀects can appear in such a strong
ﬁeld. Second, quark-gluon plasma (QGP) is expected
to be created in a strong magnetic ﬁeld thus the evolution of the plasma may have an eﬀect by the strong
magnetic ﬁeld. The state of the initial stage is another topic of recent interest. Measuring the eﬀect of
the ﬁeld should be the key to understanding the initialstage.
Chiral magnetic eﬀect is measured by experiments
using charged particle asymmetry with respect to thereaction plane which is reported by STAR and ALICE
experiments2)3) . However the ﬁeld has not yet been
directly detected by experiments. If the eﬀects of themagnetic ﬁeld can be detected, we can directly accessto the initial stage of collisions. Electro-magnetic particles are a clean probe for accessing the initial stage
because they are not aﬀected by the strong interaction.
Dilepton production rate in an external magnetic
ﬁeld is calculated using a photon vacuum polarization
tensor, and the production rate depends on the direction of the ﬁeld. The production rate is higher inperpendicular direction to the ﬁeld than that parallelto the ﬁeld.
Dilepton polarization is also measured to understandthe production mechanism of quarkonia. The PHENIX
experiment measured J/ψ polarization with dielectron
4). While the physics motivation and mechanism are
diﬀerent between the measurement of quarkonia and∗1∗2

RIKEN Nishina Center
Department of Physical Science, Hiroshima University- 116 -

Fig. 1. Definitions of polarization axis

virtual photon polarization, we are now using the same
parametrization with that analysis.
dN∝ 1 + λ cos(θ)
d cos(θ)(1)

where θ is the angle between the positive lepton ina dilepton rest frame and a certain polarization axis,and λ is the polarization parameter; if λ is positive(negative), polarization is transverse (longitudinal).
Three deﬁnitions of polarization frames are usuallyused. In the helicity (HX) frame, the axis is the dilepton momentum in the laboratory frame. In the CollinsSoper (CS) frame, the axis is the bisector between two
beams in the dilepton rest frame. In the GottfriedJackson (GJ) frame, the axis is the direction of thebeam in the dilepton rest frame.
We use the data set of Au+Au and p+p at 200
GeV/nucleon pair collected in 2004 and 2006, respectively. The PHENIX experiment has excellent electron
identiﬁcation capabilities and has succeeded in measurement of direct virtual photons.
The direct virtual photon is the probe and π 0 and η
Dalitz decay electrons are candidates of control probes
because they are from a later stage of the collisions.
Polarization measurement in p + p collisions can also
act as a control probe since a ﬁeld is not created in thecollisions.
We are measuring polarization with the following
mass regions, 0.12 < Mee < 0.3 (containing virtualphoton) and Mee < 0.12 GeV/c2 (π 0 Dalitz decay
dominant). The acceptance eﬀect is included in thecos(θ) distribution. Thus we need to correct the eﬀect
with simulation. Since the simulation does not containthe eﬀect of the magnetic ﬁeld, we can estimate the effect. We are now estimating the acceptance eﬀect withsingle particle simulations.
References
1) B.Muller et al.: Phys. Rev. Lett. 36, 517 (1976)
2) B. I. Abelev et al., Phy. Rev. Lett. 103, 251601 (2009)3) B. Avelev et at., Phys. Rev. Lett. 110, 012301 (2013)
4) A. Adare et. al., Phys. Rev. D 82, 012001 (2010)

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)√
Measurement of dielectron production in sN N = 5.02 TeV p-Pb
collisions by using the ALICE detector
S. Hayashi,∗1,∗2 H. Hamagaki,∗2 and T. Gunji∗2∗1∗2

RIKEN Nishina Center
Center for Nuclear Study, Graduate School of Science, theUniversity of Tokyo- 117 -

tracted according to Eq 1 .

Efficiency
Efficiency

singlesingleee
ϵpairtrig (mee , pT ) = 1−[1−ϵtrig (pT1 )][1−ϵtrig (pT2 )](1)

0.4
0.4

0.35
0.35
0.3
0.3

Pair
Pair Efficiency
Efficiency
Reconstruction
Reconstruction Efficiency
Efficiency
TRD
TRD Trigger
Trigger Efficiency
Efficiency

0.25
0.25
0.2
0.2
0.15
0.15
0.1
0.1
0.05
0.05

000
0

11

22

33

44

55

66

7 8
8 9
7
9 10
10
22
m (GeV/(GeV/ c
m
c ))
ee
ee

ee

2 -1

((GeV/c ) )Fig. 1. pT integrated pair eﬃciency as a function of invariant mass. Circles and boxes correspond to the pairreconstruction eﬃciency and TRD trigger eﬃciency forpairs, respectively.

ev

1./N dN/m

Heavy quark (charm and bottom quarks) measurements in heavy ion collisions provide key informationon the properties of the deconﬁned matter, the quark
gluon plasma (QGP). Since heavy quarks are produced
via gluon fusion, gluon splitting, and ﬂavor excitation,
cold nuclear matter eﬀects (CNM) cannot be negligible1) . In p-Pb collisions at the Large Hadron Collider(LHC), correlations between electrons from heavy ﬂavor decays and charged hadrons in p-Pb collisions show
the correlations in rapidity space, which may be dueto the gluon saturation or collective expansion of thesystem2) . In the electron-positron pair (dielectron)
mass spectrum, dielectrons from semi-leptonic decaysof heavy quarks are dominant at mee > 1 GeV/c2
and can be aﬀected by CNM eﬀects. The Transition
Radiation Detector (TRD) in ALICE provides online
electron trigger3) . ALICE recorded 1.4 nb−1 with the
TRD trigger in p-Pb collisions in 2012-2013, which is
20 times larger statistics than the minimum bias data
(0.067nb−1 ).
In the ALICE detector, charged tracks are reconstructed by the Inner Tracking System (ITS) and theTime Projection Chamber (TPC)4) . Electrons are
identiﬁed by dE/dx in the TPC and hadrons are rejected by a time-of-ﬂight (ToF) detector. To extract
the raw dielectron spectrum, the background is estimated using the same event like-sign pairs correctedby the relative acceptance diﬀerence between unlikesign and like-sign pairs, which is evaluated using an
event-mixing technique5) . Pair acceptance and detection eﬃciency are evaluated with the fast Monte Carlosimulation. First, the single electron eﬃciency is obtained from the full Monte Carlo calculation using the
DPMJET event generator and GEANT3 simulations.
Pair eﬃciency is extracted by the product of the single electron eﬃciency. Dielectrons from light meson′
decays (π 0 , η, ρ, ω, η , ϕ) are generated from EXODUS
according to the measured charged pion spectrum in pPb collisions and mT scaling. For heavy quarks contribution, dielectrons are generated using PYTHIA withthe parametrization tuned for the NLO calculation6) .
Figure 1 shows the pair eﬃciency as a function of invariant mass, where circles and boxes correspond to
the pair reconstruction eﬃciency and TRD trigger efﬁciency for pairs, respectively. The single electron trigger eﬃciency is calculated as the number of triggered
electrons divided by the number of minimum bias electron samples. TRD trigger eﬃciency for pairs is ex-

1
10

-1

p-Pb s10-2

TRD triggered events with TRD offline matching

10

-3

10

-4

10

-5

10

-6

10

-7

10

-8

NN

= 5.02 TeVeep > 0.4 GeV/ c, |η | < 0.8Tee

0 < p < 10 GeV/ cT

This Work

0

1

2

3

4

5

6

7

8
9
10
2
m (GeV/c )eeFig. 2. Corrected dielectron yield per inelastic p-Pb collision as a function of invariant mass.

Figure 2 shows the inclusive invariant yield of dielectrons as a function of invariant mass. The next stepis to take into account the azimuthal angle and rapidity dependence of the single electron eﬃciency in thepair and trigger eﬃciency calculations. After the invariant yield is extracted, cc and bb cross-sections will
be extracted and compared with the theoretical models to understand the dielectron production in p-Pb
collisions.
References
1) H. Fujii, K. Watanabe, NPA 920, 78-93 (2013).
2) E. Pereira de Oliveira Filho, arXiv:1404.3983v2 (2013)
NPA in press..
3) J. Klein, NIMA 706 23-28 (2013).
4) F. Carminati et al., J. Phys. G: Nucl. Part. Phys. 30
1517 1763 (2004).
5) S. Hayashi et al., CNS Ann. Rep., 2012 (2014)6) M. Mangano, et al., Nucl. Phys. B373, 295 (1992)

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Measurement of neutral pion v2 in Pb-Pb collisions at
TeV by the ALICE experiment√sN N = 2.76

T. Tsuji,∗1,∗2 H. Hamagaki,∗2 T. Gunji,∗2 for the ALICE collaboration√
In central Pb-Pb collisions at sN N = 2.76 TeV at
the Large Hadron Collider (LHC) in CERN, the yieldof particles at high transverse momentum (pT ) is observed to be strongly suppressed as compared with the
expected yield from p+p collisions scaled by the average number of the binary collisions. This suppression is
explained by the energy loss of hard scattered partonsin the medium created in heavy ion collisions. This
suppression is called jet quenching. This suppression
is quantified by the nuclear modification factor (RAA ),which is the ratio of the yield in Pb-Pb collisions to theyield in p-p collisions scaled by the nuclear thickness
function TAA  as follows:
RAA (pT ) =1

d2 NAA /dpT dy.
< TAA > d2 σpp /dpT dy

RAA (pT ) is well described by many models that employ different approaches for the calculation of partonenergy loss. For a better understanding of the energy
loss mechanisms, measurement of the path length dependence of the energy loss is crucial.1) Since the path
length is highly correlated with the azimuthal angle
with respect to the reaction plane (∆φ), RAA is measured as a function of (∆φ).
The RAA (pT , cent, ∆φ) is expressed as
RAA (pT , cent, ∆φ) = F (∆φ, pT ) · RAA (pT , cent),
where F (∆φ, pT ) is the ratio of the relative yield asgiven byF (∆φ, pT ) = N (∆φ, pT ),dφN (∆φ, pT )and N (∆φ, pT ) can be expressed in terms of a Fourier
expansion with ∆φ.
N (∆φ, pT ) ∝ 1 + 2

inf


n=1

N (∆φ, pT ) = N (1 + 2v2 cos(2∆φ)).
∗2

Fig. 1. v2 of π 0 values as a function of Npart . The data
points represent v2 of π 0 measured by the LHC-ALICE
experiment. Solid and dashed lines indicate model calculations using pQCD and Ads/CFT, respectively.

Npart at 6 GeV < pT < 20 GeV. The analysis is performed by using semi-central triggered data recorded
in 2011 Pb-Pb collisions. Solid and dashed lines represent model calculations from pQCD-based (weakly
coupled medium) and AdS/CFT-based (strongly coupled medium) energy loss models, respectively. In thisplot, the v2 of π 0 values shows the same tendency as
the v2 values of the charged particles qualitatively.3)
Comparison of the model calculations and experimental results for v2 of π 0 is currently in progress.
References(vn cos(n∆φ)),

where vn is the magnitude of the n-th order harmonic.
The second harmonic, v2 , represents the strength ofelliptic azimuthal anisotropy. Since high pT particles
are dominated by the jet fragmentation, the v2 of jets
is induced by the path length dependence of the energyloss.
The v2 is obtained by fitting the azimuthal angular
distribution of π 0 with∗1

π 0 ’s are identified by the invariant mass between
two photons with a Photon Spectrometer (PHOS).2)
Figure 1 shows the v2 of π 0 values as a function of

RIKEN Nishina Center
Center for Nuclear Study, Graduate School of Science, University of Tokyo- 118 -

1) A. Majumber: J. Phys. G. Nucl. Part. Phys. 34, S377
(2007).
2) K. Aamodt et al., for the ALICE Collaboration: JINST
3, S08002 (2008).
3) B. Abelev et al., for the ALICE Collaboration: Phys.
Lett. B719, 18-28 (2013).

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Long-range correlation in p-Pb collisions at
the ALICE detector√
sN N =5.02 TeV with

Y. Sekiguchi,∗1,∗2 H. Hamagaki,∗2 and T. Gunji∗2
Measuring of the correlations in particle productionin the azimuthal angular space and rapidity space isvery useful for investigating the underlying mechanismand dynamics of particle production in high-energy
nucleus-nucleus collisions. The long-range correlationsin the rapidity space in near-side angular pairs in dihadron correlations was ﬁrst observed in Au-Au col√lisions at sN N = 200 GeV at RHIC.1,2) This longrange correlation was derived from the collective expansion of the initial geometry ﬂuctuations. Unexpectedly, a similar structure has also√ been observedin high-multiplicity p-p collisions at s=7 TeV with
the LHC-CMS experiment.3) The high-density gluon
ﬁelds in a small x of nucleus and the collision of two
high-density gluon sheets can explain the long-range
correlation.4) It is very interesting to study the correlation in p-Pb collisions since the initial gluon density
and magnitude of the collective expansion are very different from those in other collision systems (pp and
Pb-Pb).
A Large Ion Collider Experiment (ALICE) is dedicated to understand the state of matter as it existed
shortly after the Big Bang, called Quark Gluon Plasma(QGP). The main subsystems in the ALICE for the
study are the inner tracking system (ITS), time projection chamber (TPC), and time of ﬂight (TOF). The
ITS consists of 6 layers of silicon detectors for vertex
ﬁnding and tracking. The TPC is the main tracking
detector and is used for particle identiﬁcation by measuring the speciﬁc energy loss dE/dx. The TOF is used
to identify particles by measuring the time of ﬂight.
They have a common acceptance |η| <0.9.
The correlation function as a function of ∆η and ∆ϕ
between two charged particles is deﬁned as:
1

in the same event multiplicity class. The α factor ischosen so that it is unity for pairs at (∆η, ∆ϕ) = (0, 0).
The correlation function in peripheral collisions (lowmultiplicity event class) is subtracted from that in central collisions (high-multiplicity event class) to remove
the auto-correlations from jets. Figure 1 shows theassociated yield per trigger particle in 0-20% eventclass subtracted by 60-100% event class with 1<pT,trig ,pT,asso <2 GeV. The projection onto ∆ϕ averaged over0.8< |∆η| <1.6 on the near side and |η| <1.6 on theaway side is shown in Fig. 2. The double ridge structure is observed.
Measurements of the correlation functions by tagging identiﬁed hadrons and strange baryons are ongoing to evaluate the collectivity in p-Pb collisions andthe initial state eﬀects.

0.35

0.3
∆η 1

0
-1

∆φ

Fig. 1. Associated yield per trigger partile in 0-20% eventclass subtracted by 60-100% event class with 1<pT,trig ,pT,asso <2 GeV

0.345
0.345
0.34
0.34

2

d NassoS(∆η, ∆ϕ)=
Ntrig d∆ηd∆ϕB(∆η, ∆ϕ)

4

2

0

(1)

0.335
0.335
0.33
0.33

where this correlation function is studied for diﬀerent pT intervals and diﬀerent event classes according to the event multiplicity, and Ntrig is the total
number of triggered particles in the event class and
pT,trig interval. The signal distribution S(∆η, ∆ϕ) =1/Ntrig d2 Nsame /d∆ηd∆ϕ is the associated yield per
trigger particle for particle pairs from the same
event. The background distribution B(∆η, ∆ϕ) =α1/Ntrig d2 Nmixed /d∆ηd∆ϕ corrects for pair acceptance, pair eﬃciency, and uncorrelated pairs. It isconstructed by correlating the trigger particle in one
event with the associated particles from other events∗1∗2

RIKEN Nishina Center
Center for Nuclear Study, the University of Tokyo- 119 -

0.325
0.325

-1
-1

00

11

22

33

44

�∆φφ

Fig. 2. Projection onto ∆η averaged over 0.8< |η| <1.6 on
the near side and |η| < 1.6 on the away side

References
1) STAR Collaboration, Phys. Rev. C80 (2009) 064912
2) PHOBOS Collaboration, Phys. Rev. Lett. 104 (2010)
062301
3) CMS Collaboration, JHEP 09 (2010) 091
4) K. Duslingand and R. Venugopalan, Phys, Rev, D 87
(2013) 054014

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Azimuthal distributions of jets with respect to high-pT neutral pion√√
triggers in pp collisions at s = 7 TeV and PbPb collisions at sN N
= 2.76 TeV from ALICE
D. Watanabe∗1,∗2 and T.Chujo∗2

12

T,ch,jet

8
6
4

-1

0

1

2

3

Jets are reconstructed with the anti-kT jet algorithmof the FastJet4) package combining charged tracks
measured in the central tracking devices and a cone
size parameter of R = 0.4. The contribution of underlying events is subtracted from the reconstructed jets
using the average background momentum method.
Figure.1 and 2 show the azimuthal correlation between trigger π 0 and jet in pp and PbPb collisions, respectively, with three diﬀerent trigger π 0 regions andtwo diﬀerent associated jet pT thresholds. Two clear∗1∗2

RIKEN Nishina Center
University of Tsukuba- 120 -T,ch,jet

8< p
4

trig
T

16 < p24 < p3< 12 GeV/c

trig
T
trig
T

< 20 GeV/c< 36 GeV/c

Systematic uncertainty
20

4∆ϕ (rad)

-1

0

1

2

3

4

∆ϕ (rad)√Fig. 1. π 0 -jet azimuthal correlations in pp collisions at s
= 7 TeV normalized by number of trigger π 0 for trig< 12 GeV/c, 16 < ptrig<
ger π 0 regions 8 < ptrig
TT
trig
20 GeV/c, 24 < pT < 36 GeV/c, and associated jet> 10, 20 GeV/cthresholds passo
T

14

PbPb sNN = 2.76 TeV
EMCal-trigger
Centrality:0-20 %p assoc > 10 GeV/c

12
10
8

T,jet

6

trig

This work

4
2

This analysis used the shower shape and cluster
splitting method3) to identify high pT π 0 . Using thismethod, high pT π 0 around 40 GeV/c can be identiﬁed
with a signal-to-noise ratio of 90 %.

p assoc > 20 GeV/c

5

1

2
0

6

trig

trig

10

1/N π0 dN ch,jet/d∆ϕ (rad-1)

1/N π0 dN ch,jet/d∆ϕ (rad-1)

ALICE Preliminary
pp @ s = 7 TeV
EMCal-trigger
p assoc > 10 GeV/c

140

1/N π0 dN ch,jet/d∆ϕ (rad-1)

In this paper, we report the jet azimuthal distribution
with neutral pion trigger in pp collisions at√√
s = 7 TeV and PbPb collisions at sN N = 2.76
TeV from LHC-ALICE. The ALICE detector was built
to exploit the unique physics potential of nucleusnucleus interactions at the LHC.2) This analysis usedthe central tracking devices, ITS and TPC, for charged
particle track measurements, and the electromagnetic
calorimeter EMCal for π 0 measurements.

16

trig

In general, the energy loss of recoil jets and leading jets depends on the path length in the medium.
For example, jet pairs with a large energy asymmetry in the ﬁnal states can be from the surface of themedium. While leading jets escape the medium fromthe surface, recoil jets traverse in the medium with loss
to its energy. We can use this surface bias to obtaindeeper insight into the properties of the medium. The
stronger the surface bias, the greater is the path length
in the dense medium of the recoiling jet at the opposite
azimuth. By measuring the full jets in the recoil siderather than measuring high-pT leading hadrons, we canperform a more comprehensive and direct study of jet
interactions with the medium.1)

jet peaks are observed, indicating that high pT production is corelated with jet production. Both near andaway-side widths decrease with increasing pT of thetrigger π 0 . The decrease is stronger for the away-side
correlation width. As the next step, we plan to study
the path length dependence by selecting diﬀerent trigger π 0 pT in the ratio of the per-trigger yield (IAA ).

1/N π0 dN ch,jet/d∆ϕ (rad-1)

Jet measurements play a critical role in probing the
hot and high energy density matter created in heavy
ion collisions. Energy loss of patrons can be studied
by measuring changes in the jet structure during jet
suppression.

98

p assoc > 20 GeV/c
T,jet

7

8< p

6

trig
T,π0

16 < p5

24 < p4
3< 12 GeV/c

trig
T,π0
trig
T,π0

< 20 GeV/c< 36 GeV/c

2
1

-1

0

1

2

3

4
∆ϕ (rad)

0

-1

0

1

2

3

4
∆ϕ (rad)Fig. 2. π 0 -jet azimuthal correlations in PbPb collsions at√
sN N = 2.76 TeV normalized by number of trigger π 0 .
Trigger π 0 pT regions and associated jet pT thresholds
are same as Fig.1.

References
1) ALICE collaboration, An Addendum to the EMCal
Technical Design Report (DCAL), CERN-LHCC-2010011
2) ALICE collaboration, Performance of the ALICE Experiment at the CERN LHC, arXiv:1402.4476v2
3) ALICE collaboration, X. ZHU, Analysis of the π0Charged Hadron Correlations Using ALICE EMCAL,
https://indico.cern.ch/event/181055/session/37/
contribution/451
4) M. Cacciari, G. P. Salam, G. Soyez et al.: CERN-PHTH/2011-297

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Study of ion backflow with 2GEMs + MICROMEGAS for the
Study of ion backflow
withupgrade
2GEMs + MICROMEGAS for the
ALICE-TPC
ALICE-TPC upgrade

Energy resolution (%)

K. Terasaki,∗1,∗2 H. Hamagaki,∗2 and T. Gunji∗2
K. Terasaki,∗1,∗2 H. Hamagaki,∗2 and T. Gunji∗2
ALICE is the dedicated experiment to study Quark
Gluon PlasmaALICE(QGP),
a hot
and dense
Quantumis thededicated
experiment
to study Quark
chromodynamics
heavy
iondense
col- Quantum
Gluon(QCD)
Plasmamedium,(QGP), via
a hot
and
lisions at LHC.
The ALICE Time
Projection
Chamberchromodynamics(QCD)
medium,via heavy ion col1)(ALICE-TPC),
which
is thedevicein Projection
the cen- Chamberlisionsat LHC.
Themain
ALICE
Time1) particle identiﬁcation oftral barrel (ALICE-TPC),
for tracking andwhich is the main device in the cen3
charged particles,
consistsof a 90 m
cylindertral barrel
for tracking
andparticle ﬁlled
identiﬁcation ofwith Ne/COcharged
particles, consists of a 90 m3 cylinder ﬁlled
2 /N2 (90/10/5).
Secondarywith
ionsNe/CO
generated
an electron-avalanche(90/10/5).
2 /N2 inprocess in the Secondary
TPC returnions
to thedrift space,known
asgenerated
in anelectron-avalanche“Ion Backﬂow(IBF).”
BecauseIBF distorts
the elecprocess
in the
TPC returnto the drift
space, known as
Fig.
1. A schematic of measurement setup with 2GEMs +tric ﬁeld in “Ionthe drift
space,(IBF).”
its reduction
is essential
to theBackﬂow
BecauseIBF distorts
elecMICROMEGAS.
Fig. 1. A schematic of measurement setup with 2GEMs +achieve good
performancethespace,
TPC.itsA reduction
gating grid
tric
ﬁeld in the ofdrift
is essential to
MICROMEGAS.
system is widely
employed
to reduce IBF;
however,achievegood performanceof theTPC. Ait gating grid
limits the dataacquisition
to thetoorderof IBF;kilo- however, it
systemis widely rate
employed
reducehertz. Thelimits
rate ofcollisionsrate
at tothetheLHC
theheavy-ion
data acquisition
order of kilo- 20
will be 50 kHz
from
2019.
ALICE-TPC
will beat the LHC
hertz.
The
rateTheof heavy-ion
collisions
20
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upgraded towill
readbeoutof Pb-Pbcollisions
con50thekHzdatafrom2019. TheALICE-TPC
will be18
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tinuously, which
requires
IBF out
andtheenergyupgraded
to readdataresolutionof Pb-Pb forcollisions con- 16
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Fe to be lessthan 1.0%
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respectively,
at resolutionatinuously,
whichandrequiresand energy
for 142)55
gain of 2000 for
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than1.0% and 12%, respectively, at a 12
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for Ne-basedgas mixtures.
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readout chamber
being investigated
for this
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grade. In addition,with 2GEMs+ MI-for this up- 8
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CROMEGAS
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addition,with 2GEMs + MI- 6
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CROMEGAS
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IBF (%)(%)
multiplied throughapplicationa potential
diﬀermicromesh∼ 100 µmofabovea readout.
Electrons areFig.
2. Energy resolution as a function of IBF for Ne/CO2
ence between
the mesh throughand the readout(∆VMM
Secmultiplied
applicationof a). potential
diﬀer(black)and(red).
Fig.Ne/CO
2. Energy
as a function of IBF for Ne/CO2
2 /N2resolution
ondary ionsence
are absorbed
eﬃciently
on the meshwhenbetween themesh andreadout(∆VMM ). Sec(black)
and
Ne/CO
/N
2
2 (red).
the electric ﬁeld
above
is considerably
ondaryionsthearemeshabsorbed
eﬃcientlysmaller
on the mesh when(by a factortheof 100)
than
that
below
mesh.
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pointsmarkers; formeasurements
by thediﬀerent+ MICROMEGAS
is shown
Fig. 1. Our
MI-with 2GEMs
A schematicof theinmeasurement
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corresponding
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and the points
example,the
GEM1-MMscan
represents
CROMEGAS
has
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(Lines
Per
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mesh
GEM1
+ MICROMEGAS is shown in Fig. 1. Our MI2∆Vtomaintain
the
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It
shows
that
cercorresponding
tovariations
ofboth∆VGEM1 andlocated 128 CROMEGASµm above 120 has
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shows
that cer2
and the current
from
all
the
readoutpads
issummedlocated 128 µm above 120 readout pads (8 × 10 mm )
MM
and
IBF
is
less
than
0.5%
at
an
energyresolutionoftain
pointsmeettherequirement
for
Ne/CO
up. Two 50µm-thickGEMs
areplacedabove
MI2 (90/10)
and the current from all the readout pads is summed
∼
12%
for
Ne/CO
/N
(90/10/5).
Additional
nitroand
IBF
is
less
than
0.5%
at
an
energyresolutionof2
2
CROMEGAS.
IBF
isdeﬁned
as
I
/I
,
where
I
and
up. Two 50 µm-thickc GEMs
are placed
above MIa
c
gen
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to
betterIBF
becausealargerpotential
dif∼
12%
for
Ne/CO
/N
(90/10/5).
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plane
and
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2
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CROMEGAS. IBF is deﬁned as Ic /Ia , where Ic andferenceto achieve
thegainof 2000a andsubgen leads
to betterIBFbecauselargerpotential difthe anode pads,
calculated
Ia are respectively.
the current atGain
the iscathodeplaneasand thatat is requiredsequently
ﬁeld ratioof MICROMEGAS
ferenceis required
to achieve the decreases.
gain of 2000 and subIa /(Nseed × theR × e),
where
Nseed, R, and e areGain
the numanodepads,
respectively.
is calculated
as theevaluation
for Ne/CO
at a better decreases.
sequently
the ﬁeldof MICROMEGAS
2 /Nratio
2 (90/10/5)
ber of seed Ielectronsfor
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rate eofare theThe
R ×55e),R, andnuma /(Nseed ×
seed ,the55(and worseforIBF)
is in 2progress.
Even- at a better
The evaluation
Ne/CO/N2 (90/10/5)
X-ray from ber
Fe,chargeforof 55
anFeelectron,
re- the energyof andseed theelectrons
in Ne gas,
rate of resolution
tually,of a MICROMEGAS
that
has
energy resolution(and worse IBF) isin progress.
Evenspectively. X-ray from 55 Fe, and the charge of an electron,
re- the performancea 780 LPI micromesh
90 µm gapofwill
be evaluated. that has
tually, theandperformancea MICROMEGAS
The correlation
between energy resolution and IBF
spectively.
a 780 LPI micromesh and 90 µm gap will be evaluated.
for Ne/CO2 (90/10)
and Ne/CO
with and IBF
The correlation
betweenenergy resolution
2 /N2 (90/10/5)
References
diﬀerent voltage
setups2 (90/10)
is shownand
in Fig.
2. 2Diﬀerent
for Ne/CO
Ne/CO/N2 (90/10/5)
with1) CERN-LHCC-2000-001
References (2000).
diﬀerent voltage setups is shown in Fig. 2. Diﬀerent
GEM1-MM scan (VEnergyEnergy resolution
resolution (%)(%)

GEM1-MM scan (VGEM1-MM scan (V=210V) (Ne/CO )

GEM2

2

=230V) (Ne/CO )2=250V)GEM1-MM(Ne/CO ) scan (V

GEM2
GEM2

GEM1 scan (Ne/CO /N2)2

Et1 scan (Ne/CO /N2)
2

2

GEM1-MM scan (V=210V) (Ne/CO(Ne/CO ))

GEM2

22

GEM2
GEM2

22

GEM2

2

=230V) (Ne/CO(Ne/CO ))GEM1-MM scan
scan (V(VGEM2=250V)=250V) (Ne/CO(Ne/CO2))

GEM1
scan (Ne/CO
scan(Ne/CO /N/N ))GEM1-GEM2 scan (Ne/CO /NGEM1
)
2
2 22
2
2
Et1
scan (Ne/CO(Ne/CO/N
scan/N22))
GEM2-MM scan (V=220V)Et1(Ne/CO/N )GEM1

GEM2-MM scan (VGEM2-MM scan (VGEM2-MM scan (V

2

2

2

2

2
2

GEM1-GEM2
scan (Ne/CO(Ne/CO /N/N ))=230V)GEM1-GEM2(Ne/CO /N2) scan
22 222
GEM2-MM(V=220V)
scan(V=220V) (Ne/CO(Ne/CO /N/N22))=240V)GEM2-MM(Ne/CO /Nscan
)

GEM1
GEM1

GEM1
GEM1

22

GEM1
GEM1

22

GEM1

2

GEM2-MM(V
scan(VGEM1=230V)=230V) (Ne/CO(Ne/CO2/N/N ))=250V)GEM2-MM(Ne/CO /Nscan
)
GEM1
2 22
2
2
GEM2-MM scan
=240V)
GEM2-MMscan (V(V=240V) (Ne/CO(Ne/CO /N/N22))GEM1

GEM2-MM scan
GEM2-MMscan (V(VGEM1=250V)=250V) (Ne/CO(Ne/CO2/N/N22))∗1∗22) CERN-LHCC-2013-020(2013).
1) CERN-LHCC-2000-001(2000).
RIKEN Nishina Center
3)
Y.
Giomataris
et
al.:
Nucl.
Instr. and(2013).
Meth. A 376, 29
2)
CERN-LHCC-2013-020
Center for∗1Nuclear
Study,
Graduate
Schoolof
Science,
UniRIKEN Nishina Center
versity of ∗2Tokyo3) Y. Giomataris et al.: Nucl. Instr. and Meth. A 376, 29Center for Nuclear Study, Graduate School of Science, (1996).
Uni(1996).

versity of Tokyo- 121 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Search for dark photons from neutral meson decays in p + p and√d+Au collisions at sN N =200 GeV†
Y. Akiba∗1 and Y. Yamaguchi∗2,∗3 for PHENIX Collaboration

ε QED µν
Lmix = − Fµν
Fdark ,
2
where ε parameterizes the mixing strength. Dark photons can then mix with the QED photon through allprocesses that involves QED photons.
The PHENIX experiment searched for possible decays of π 0 , η → γU , U → e+ e− by examining theinvariant mass mee of e+ e− pairs in a large sampleof Dalitz decays, π 0 , η → γe+ e− for 30 < mU < 90
MeV/c2 in the dark photon parameter space. The
weak coupling of the dark photon with the QED photon implies that the natural width of the dark photon
is very narrow. Thus if the dark photon mass is in thisrange, a clear dark photon signal should appear as anarrow peak in the e+ e− mass spectrum.
We used the data set of p + p collisions in the 2006
and 2009 runs and d+Au collisions in the 2008 run,√at sN N = 200 GeV, but did not find any significant
signal. Thus, we set the upper limit on the mixing
parameter ε2 as a function of the dark photon massmU .
Fig.1 shows the limits determined by the PHENIX
along with the 90% confidence level (CL) limits fromother experiments and the 2σ upper limit theoretically calculated from (g − 2)e . The band indicates therange of parameters that would allow the dark photon to explain the (g − 2)µ anomalies with 90% CL.
The PHENIX experiment limits exclude the values of
†

∗1
∗2
∗3

Condensed from the article in Phys. Rev. C91:031901(R)(2015)
RIKEN Nishina Center
CNS, University of Tokyo
Stony Brook University- 122 -10-4

A1 (MAMI)

electron g-2 2σKLOE
ε 90% CLThe standard model (SM) of particle physics provides unprecedented numerical accuracy for quantities
such as the anomalous magnetic moment of the electron (g − 2)e . Hence, measurements that lie outside
SM predictions warrant a special investigation. One
such result is the measured value of (g − 2)µ , which
deviates from SM calculations by 3.6σ. An intriguing
explanation for this discrepancy has been proposed byadding a “dark photon”1) . This possibility has recently
gained more relevance because it provides a simultaneous explanation of various beyond-the-standard-model
phenomena in addition to (g − 2)µ . These includes the
positron excess observed by PAMELLA, FERMI, and
AMS-2 satellite experiments.
A simple formulation of the dark sector postulatesa “dark photon” U of mass mU that mixes with the
QED photon via the “kinetic coupling” term in the
Lagrangian

-5

10

WASA
muon g-2 90% CL

HADES

PHENIX

BaBar
-6

10

10

20

30

40

50

60

70

80
90 100mU [MeV/c 2]

Fig. 1. A compilation of the limits of the U γ mixing parameter, showing the PHENIX results, together withother experiments and the band indicating the range ofmass and coupling parameters favored by the (g − 2)µanomaly at 90% CL. Also shown is the 2σ upper limit
obtained from (g − 2)e .

the coupling favored by the (g − 2)µ anomaly above
mU > 36 MeV/c2 . Recently, BaBar reported stricter
limits from a search of the reaction e+ e− → γU, U →l+ l− , excluding values of the preferred (g − 2)µ region
for mU > 32 MeV/c22) . As a result, nearly all theavailable parameter space that would allow the dark
photon to explain the (g − 2)µ results are ruled out
at 90% CL by independent experiments. The entire
parameter space to explain the (g − 2)µ anomaly by
the dark photon can be excluded at 85% CL by the
PHENIX data alone. The level of compatibility between our data and the coupling strength favored forthe (g − 2)µ anomaly is 10% with a statistical test.
In summary, the PHENIX results set limits for the
coupling of a dark photon to the QED photon over themass range 30 < mU < 90 MeV/c2 . Combining with
the BaBar results, the dark photon is ruled out at
90% CL as an explanation for the (g − 2)µ anomaly
for mU > 32 MeV/c2 , leaving only a small remaining
part of the parameter space in the region 29 < mU <32 MeV/c2 .
References
1) P. Fayet, Phys. Rev. D75:115017(2007).
2) J. Lees et al. (BaBar Collaboration), Phys. Rev.
Lett.113:201801 (2014).

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Progress in probing flavor asymmetry of antiquarks in protons in theE906/SeaQuest experiment at Fermilab
K. Nagai,∗1 Y. Goto,∗2 Y. Miyachi,∗3 S. Miyasaka,∗1 K. Nakano,∗1 S. Nara,∗3 S. Sawada,∗2,∗4 T.-A. Shibata∗1,∗2
for the E906/SeaQuest Collaboration
E906/SeaQuest is a Drell–Yan experiment at
Fermi National Accelerator Laboratory (Fermilab).
SeaQuest aims to measure the ﬂavor asymmetry of¯
antiquarks (d/ū)in protons at large Bjorken x moreaccurately than the E866 experiment, which is theDrell–Yan experiment conducted previously at Fermilab.1) The ﬂavor asymmetry is derived from the ratioof the Drell–Yan cross sections in proton-proton (pp)and proton-deuteron (pd) reactions, as shown below:
[
]
σ pd
d¯
1
1+
.
(1)
∼
2σ pp
2
ū

that of random backgrounds was estimated using realdata. The experimental data ware ﬁtted reasonably
well to simulated events and estimated backgrounds,
which suggests the detectors and the algorithm of dimuon reconstruction work as expected. The Drell–Yan
events were selected with a di-muon cut-oﬀ mass of 4.2
GeV. We evaluated the cross-section ratio using theyields of the Drell–Yan events in the pp and pd inter¯actions. The ﬂavor asymmetry (d/ū)was derived fromthe cross-section ratio using Eq. 1. The magnitude and¯ are currently being evaluated.
systematic error of d/ū¯Thus, Fig. 2 shows only the statistical errors of d/ūWe use a 120-GeV proton beam extracted from Fermilab Main Injector and liquid hydrogen and deuteriumas targets. Carbon, iron, and tungsten are also used
as targets for measuring nuclear eﬀects on the parton
distribution. The Drell–Yan process creates a µ+ µ−
pair, and therefore the muons are measured to countthe number of Drell–Yan events. SeaQuest acquired
data for 10 months in 2013 and 2014 (called “Run 2”).
Data acquired over two months of the data were analyzed as an initial step. Results of the analyzed dataand prospects are discussed in this report.
1800


 
Events/ 100 MeV

- Drell–Yan
- J/ψ- ψ'-Background 

1400

1200

1000

800


¯ vs Bjorken x obtained by E866 (blueFig. 2. Plot of d/ūpoints), and the size of statistical errors expected in the
SeaQuest experiment (red points) and that obtainedusing the analyzed data (green points).

600

400


1

2

3

4

5

6

Mass (GeV)

7

8

9

10


Fig. 1. Reconstructed di-muon mass distribution with all
the targets (black points). It is fitted with four components (red, green, yellow, and black lines).

We succeeded in reconstructing the mass distribution of di-muons with all the targets as shown in Fig. 1.
The mass distribution was ﬁtted with four components, Drell–Yan events, J/ψ events, ψ ′ events, andrandom backgrounds. The distribution shapes of theDrell–Yan, J/ψ, and ψ ′ events were simulated, while
∗1
∗2
∗3
∗4

E906Run-II
 POT
6.4×10 16

E906
preliminary


1600


200

00



of• PartGraduate School of Science and Engineering, Tokyo Institute of Technology
RIKEN Nishina Center
Faculty of Science, Yamagata University
Institute of Particle and Nuclear Studies, KEK- 123 -

using the analyzed data, together with the previous
measurement results. The amount of analyzed data at
small x is approximately the same as that of the E866
data.
We started acquiring another set of data for two
years in November 2014. After data acquisition, we
will obtain 20 times more statistics than the set of data
we analyzed. The result that will be obtained using in
the SeaQuest experiment will considerably improve theunderstanding of the internal structure of protons.
References
1) E.A. Hawker et al.: E866/NuSea, Phys. Rev. Lett. 80,
3715 (1998)

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-4. Hadron Physics

Results of the K − pp bound-state search in J-PARC E151st
T. Hashimoto,∗1 K. Itahashi,∗1 M. Iwasaki,∗1 Y. Ma,∗1 H. Ohnishi,∗1 S. Okada,∗1 H. Outa,∗1 F. Sakuma,∗1
M. Sato,∗1 M. Tokuda,∗1 and Q. Zhang,∗1 for the J-PARC E15 collaboration∗1

RIKEN Nishina Center- 124 -

structed from a π − p pair detected using the CDS to
be almost free from the background. Missing-neutron
events were identified by the 3 He(K − , Λp)X missing
mass, with ∼ 20% Σ0 p-event contamination (Σ0 →Λγ). The preliminary Λp invariant-mass spectrum, obtained with ∼ 10 MeV/c2 resolution, consists of a flatcomponent widely distributed in the three-body phasespace and an enhancement around the threshold. The
threshold structure mainly originates from events witha low-momentum transfer, and it might be evidence
for the K − pp bound state.
In 2015, we plan to conduct the 2nd-stage physics
run with 10 times the number of beam-kaons in the 1ststage, as well as calibration runs with hydrogen anddeuteron targets. With the new data set, we will further investigate the structure around the K − pp binding threshold.
Binding Energy [GeV]0
K s -tagged

0

×102
30
25
20

100
2.25 2.3 2.35 2.4 2.45 2.5

15

M(Λ(1405)+p)

M(Σ +N+π)M(Λ+N+π)40

M(Σ +N)

60

M(Λ+p)

80

10
5

20
0
2

Counts / 10 MeV/c2

120

0.1

M(K+p+p)

140

0.2

M(K+p+p)160

Arbitrary unit

0.3

d2σ/dΩ/dM × ACDS (μb/sr/(MeV/c2))

The interaction between a nucleon and an anti-kaon(K̄), the lightest hadron with a strange quark, is one of
the keys to understanding meson-baryon interactions
in low energy quantum chromodynamics (QCD) incorporating three flavors in the nuclear system. Precise
measurements of elementary K̄N interactions and investigations of K̄-nuclear bound systems (K̄ nuclei)
are currently hot topics. The K − pp state, a boundsystem of a negative kaon and two protons, is theoretically considered the simplest K̄ nucleus,1) and thus
it has attracted special interest. We are searching for
the K − pp bound state by using an in-flight reaction as
the J-PARC E15 experiment.2) The first physics dataacquisition (E151st ) was performed in May 2013, with
5 × 109 kaons at 1 GeV/c on a liquid 3 He target.
Figure 1 shows the obtained semi-inclusive neutron
spectrum at θnlab = 0◦ .3) Here, we detected the neutron
by using a plastic scintillator array ∼ 15 m away fromthe target. To reconstruct the reaction vertex for thetime-of-flight measurement, at least one charged track
is required in a cylindrical detector system (CDS) surrounding the target. The K 0 -tagged spectrum, shownin the inset of Fig. 1, is attributed to the chargeexchange K − p → Ks0 n reaction, and demonstrates
that the detector resolution and the missing-mass scale
are well understood.
The observed yield in the deeply bound region, corresponding to K − pp binding energies larger than 80
MeV, was in good agreement with the evaluated backgrounds originating from 1) accidental hits and neutral
particles other than neutrons, 2) reactions on the target cell, and 3) neutrons produced via charged Σ decay.
In this mass region, upper limits on the production
cross section of a bound state were evaluated, assuming
a K − pp → Λp isotropic decay. They were determined
to be 30-270 µb/sr, depending on the mass and the decay width. The upper limits obtained are much smaller
than the theoretical calculation.4) The ratios of the upper limits to cross sections of the quasi-elastic channels
are (0.5–5)% (quasi-elastic) and (0.3–3)% (charge exchange). These ratios are rather small compared tothe sticking probability of the usual hypernucleus formation. On the other hand, a significant excess wasobserved around the K − pp binding threshold. However, in spite of the observed large yield corresponding
to ∼ 1 mb/sr, structures suggested in theoretical spectral functions4,5) cannot be identified from only thesemi-inclusive measurement.
We also analyzed the Λp events detected using the
CDS to investigate the K − pp decay. A Λ was recon-

2.1
3

2.2
-

2.3

2.4

2.5

2.6

0
2.7

2

He(K ,n)X missing mass (GeV/c )Fig. 1. 3 He(K − , n)X semi-inclusive missing-mass distribution at θnlab = 0◦ 3) . ACDS denotes the charged-tagging
acceptance of the CDS. The inset shows the Ks0 -tagged
spectrum.

References
1) T. Yamazaki and Y. Akaishi: Phys. Lett. B 535 (2002)
70.
2) M. Iwasaki et al.: J-PARC proposal P15, “A searchfor deeply-bound kaonic nuclear states by in-flight3
He(K − , n) reaction” (2005).
3) T. Hashimoto et al.: arXiv:1408.5637 (2014).
4) T. Koike and T. Harada: Phys. Rev. C 80 (2009)055208.
5) J. Yamagata-Sekihara, D. Jido, H. Nagahiro, and S.
Hirenzaki: Phys. Rev. C 80 (2009) 045204.

Ⅱ-4. Hadron Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Measurement of the proton Zemach radius from the hyperfine
splitting energy in ground-state muonic hydrogen
M. Sato,∗1 S. Aikawa,∗2 K. Ishida,∗1 M. Iwasaki,∗1,∗2 S. Kanda,∗3 Y. Ma,∗1 Y. Matsuda,∗4 T. Matsuzaki,∗1
K. Midorikawa,∗5 Y. Oishi,∗1 S. Okada,∗1 N. Saito,∗5 A. Takamine,∗6 K. Tanaka,∗1,∗4 H. Ueno,∗1 and S. Wada∗5Studies of the proton electromagnetic structure haverecently attracted great interest stimulated by the proton radius puzzle, which is a 7σ discrepancy in the
proton charge radius determined using two diﬀerent
methods. One is a traditional determination method
using e − p scattering and the atomic hydrogen spectroscopies as compiled in CODATA1) . The other isa method of laser spectroscopy of the Lamb shift inmuonic hydrogen2) . To understand this inconsistency
between “electronic” and “muonic” methods, there areseveral hypotheses including physics beyond the Standard Model. However, none of them are conclusive,
and the puzzle is still an unsettled question.
Since the proton charge radius is deﬁned only fromthe electric distribution in the proton, it is a curious
question as to how we can determine the magnetic distribution of a proton probed with muons, which may
become a clue to solve the puzzle. Therefore, we focus
on the proton Zemach radius, which contains information on both the charge and magnetic-moment distributions in the proton. The proton Zemach radius, RZ ,is expressed as∫∫
RZ = d3 r|r| d3 r′ ρE (r′ )ρM (r − r′ ),where ρE and ρM denote spatial distributions of thecharge and magnetic moment of the proton, respectively. This Zemach radius can be determined fromthe hyperﬁne splitting energy of a hydrogen-like atom.
Thus, we determine the proton Zemach radius from thelaser spectroscopy of the hyperﬁne splitting energy ofmuonic hydrogen.
The experimental principle is as follows. When
negative muons are stopped in hydrogen, they form
muonic hydrogen atoms and are quickly deexcited to
the ground state. Its energy level is split into hyperﬁne sublevels by the spin combination of the protonand muon: the spin singlet (F = 0) and the triplet (F= 1) states. The splitting energy is ∼0.183 eV, whichcorresponds to a mid-infrared frequency of 44.2 THz
and wavelength of 6.78 µm. We will measure this energy through a laser spectroscopy. To search for the
resonance frequency, the spatial asymmetry of spinpolarized muon decays is used. To populate the spin

∗1
∗2
∗3
∗4
∗5
∗6

RIKEN Nishina Center
Department of Physics, Tokyo Institute of Technology
Department of Physics, The University of Tokyo
Graduate School of Arts and Science, The University ofTokyo
RIKEN Center for Advanced Photonics
Department of Physics and Mathematics, Aoyama Gakuin
University

polarization in F = 1, we use a circularly polarizedlaser. A speciﬁc F = 1 state is selectively excited because of the conservation of the total angular momentum. The electrons from polarized muon decays aredetected to ﬁnd the decay asymmetry during the laser
frequency scan.
A conceptual drawing of the experimental setup is
shown in Fig. 1. Negative muons with momenta of
40 MeV/c are stopped in a gas hydrogen target. The
density of the hydrogen gas is optimized to be 0.01%
of LHD (liquid hydrogen density) to suppress the collisional quench process, which is a deexcitation fromF = 1 to F = 0 through a collision with a neighboring atoms. The mid-infrared laser is injected from theside of the target ∼ 1 µs after the stopped µ− timing. The laser power is a key issue to achieve suﬃcientpolarization through a laser-induced excitation. The
laser system is under development in RIKEN3) , andthe achievable laser performance is a power of 40 mJ
and bandwidth of 50 MHz with a repetition rate of
50 Hz. For further enhancing the eﬀective laser powerby multiple reﬂection, a multi-pass cavity consisting of
two mirrors facing each other is installed in the hydrogen target, as schematically illustrated in the ﬁgure.
The mirror reﬂectivity is assumed to be 99.95% andthe resulting polarization is ∼16%.
The yield estimation and a feasibility study of thepresent measurement are nearing completion. A beam
study with negative muons in RIKEN-RAL is scheduled for the next ﬁscal year.

ee-µµ−−

forwardforward countercounterH
H22
mirrormirror

00

10
10 cm
cm

backward
backward countercounter
laser
laser

Fig. 1. Conceptual drawing of the experimental setup.

References
1) P. J. Mohr, B. N. Taylor, D. B. Newell: Rev. Mod. Phys.
84, 1527 (2012).
2) R. Pohl et al.: Nature 466, 213 (2010).
3) N. Saito et al.: Proc. of SPIE, Vol. 8526, 852605 (2012).

- 125 -

5. Hadron Physics (Theory)Ⅱ-5. Hadron Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Strong enhancement of jet-medium coupling in the quark-gluon
plasma near transition temperature†
J. Liao∗1,∗2

†
∗1
∗2

Condensed from the articles in Phys. Rev. D. 89, 126006(2014) and in arXiv:1411.3673.
Physics Department and Center for Exploration of Energy
and Matter, Indiana University
RIKEN Nishina Center- 127 -

�
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3

4

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Fig. 1. Temperature dependence of jet-medium couplingfrom a non-conformal holographic QCD model4) .

�qF T 3A new, deconﬁned form of QCD matter known as
the quark-gluon plasma is created in relativistic heavy
ion collisions. In such collisions, highly energetic jets
provide unique probe of the quark-gluon plasma properties. The observable quantifying jet energy loss isthe nuclear modiﬁcation factor, RAA as well as its
azimuthal anisotropy characterized by its second harmonic coeﬃcient v2 . Both RHIC and LHC measurements have shown a sizable v2 in the high pt region.
Recently the temperature dependence of jet-medium
coupling, which may be quantiﬁed by the so-called
jet transport coeﬃcient q̂(T ), has attracted signiﬁcant interest. As was ﬁrst found in1) , the geometricanisotropy v2 at high pt is particularly sensitive to suchtemperature dependence, and a simultaneous description of high pT RAA and v2 at RHIC requires a strong
enhancement of jet-medium coupling in the near-Tc region. Furthermore, the near-Tc enhancement predicts
a visible reduction of average opaqueness of the ﬁreballfrom RHIC to LHC which was conﬁrmed by analyzing
how the RAA evolves with beam energy2,3) . Therefore
phenomenologically there are robust evidences for suchnear-Tc enhancement, while a precise theoretical determination of such nontrivial T-dependence has not been
known owing to the highly nonperturbative dynamics
in the near-Tc regime.
One important approach for strongly coupled quarkgluon plasma is to use holographic QCD models. It
is particularly important to introduce non-conformal
physics that is most prominent around Tc . By constructing such a model4) , we have found that: 1) there
are strong non-conformal, non-perturbative dynamics
going on in the near-Tc region; 2) such dynamics leads
to non-monotonic behavior in QGP thermodynamics
as shown by the strong near-Tc peak of trace anomaly(which is well modeled by holography); 3) the same
dynamics leads to non-monotonic behavior in QGP
transport properties and in particular strong near-Tc
enhancement of jet-medium coupling q̂/T 3 (see Fig.1).
More recently we have developed a new jet quenching framework, CUJET3.05) , that is shown to accountwell for both high pT single inclusive hadron suppression RAA and its azimuthal anisotropy v2 at both
RHIC and the LHC energies. CUJET3.0 model includes two new nonperturbative eﬀects in the QCD
transition temperature range T ∼ 140 − 250 MeV: (1)the Polyakov loop suppression of color-electric scatter-

0.2

v3.0
0.3

v2.0

0.4

T GeV

0.5

0.5

0.6

0.6

Fig. 2. Temperature dependence of jet-medium couplingfrom the CUJET3.0 model5) .

ing and (2) the enhancement of scattering due to emergent magnetic monopoles near Tc . We ﬁnd that the
CUJET3.0 jet transport parameter q̂(E, T )/T 3 peaks
near Tc and has very strong nonconformal E and T
dependence up to T ∼ 400 MeV. Extrapolating down
to E = 2 GeV, we ﬁnd a striking new connection between bulk perfect ﬂuidity with η/s ∼ 0.1 near Tc andhigh pT high T perturbative jet quenching.
References
1) J. Liao and E. Shuryak, Phys. Rev. Lett. 102, 202302(2009).
2) X. Zhang and J. Liao, Phys. Rev. C 89, no. 1, 014907(2014).
3) X. Zhang and J. Liao, Phys. Rev. C 87, 044910 (2013).
4) D. Li, J. Liao and M. Huang, Phys. Rev. D 89, no. 12,126006 (2014).
5) J. Xu, J. Liao and M. Gyulassy, arXiv:1411.3673 [hepph].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-5. Hadron Physics (Theory)

Magnetic moments of light nuclei from lattice QCD†
S. Beane,∗1 E. Chang,∗2 S. Cohen,∗2 W. Detmold,∗3 H. Lin,∗1 K. Orginos,∗4 A. Parreno,∗5 M. Savage,∗2 andB. Tiburzi∗6
The structure and dynamics of nuclei have been
extensively probed using electromagnetic interactions.
Magnetic moments historically helped support a picture of light nuclei as collections of weakly interacting
nucleons, which led to the phenomenologically successful shell-model description of nuclei. At a fundamental level, however, nuclei are bound states of the quarkand gluon degrees of freedom of QCD. Nuclear forces
emerge from QCD as a consequence of confinement andchiral symmetry breaking. Yet, nuclei are not simply
collections of quarks and gluons determined by global
quantum numbers; rather, nuclei have the structureof interacting nucleons, and this feature remains to beunderstood at a deep level. Knowledge of the quark
structure of nuclei, moreover, is required to turn nuclei
into laboratories for probing fundamental symmetries,
and pushing the limits of the Standard Model.
We have computed magnetic moments of the lightest few nuclei using lattice QCD. These calculations,the first of their kind, have been performed at unphysical light-quark masses. All three light-quark masses inour computation were set equal to the physical strange
quark mass. At this SU (3) flavor-symmetric point, theresulting pion mass is mπ ≈ 800 MeV. Further details of
the lattice action and gauge configurations are found in
Ref.2) . To compute magnetic moments, U (1)Q gauge
links giving rise to a uniform magnetic field were post
multiplied onto each QCD gauge field. While quenching sea quark electric charges is an approximation,
there are no contributions to magnetic moments resulting from coupling the magnetic field to sea quarks
in our computation This fact owes to the three degenerate quark flavors withelectric charge
 their non-singlet
matrix, Q = e diag + 23 , − 31 , − 13 . Sub-percent QED
effects, however, have been neglected in our computation. The combined gauge fields were used to compute
up and down (≡ strange) quark propagators, whichwere then contracted to form the required nuclear correlation functions using the techniques of Ref.3) . Finally nuclear correlation functions were projected onto
spin components with respect to the direction of themagnetic field.
†
∗1
∗2
∗3
∗4
∗5
∗6

Condensed from Reference1)
Dept. of Physics, University of Washington, Seattle
Dept. of Physics, University of Washington, Seattle; andInstitute for Nuclear Theory, Seattle
Center for Theoretical Physics, MIT, Cambridge
Dept. of Physics, College of William and Mary, Williamsburg; and JLab, Newport News
Dept. d’Estructura i Constituents de la Matèria (ICC), Universitat de Barcelona
Dept. of Physics, The City College of New York (CUNY);
and RIKEN–BNL Research Center- 128 -

Fig. 1. Nuclear magnetic moments computed using lattice
QCD at the SU (3) flavor-symmetric point1) . Results inlattice nuclear magnetons [LNM] (blue bands) are remarkably close to experimentally measured moments inphysical nuclear magnetons (dashed red lines). Despite
deep binding found at this unphysically large quark
mass, magnetic moments of light nuclei are close to
those predicted from simple shell-model configurations.

The ground-state energy of a non-relativistic hadron
having mass M , and charge Qe is given by� = M + e |QB|
� − �µ · B
� + O(B 2 ).
E(B)
(1)
2M
The field-dependent terms appearing above are due tothe lowest Landau level and Zeeman interaction, which
is proportional to the hadron’s magnetic moment, µ.
To isolate magnetic moments with good statistical precision, the long Euclidean-time limit of correlator ratios was utilized. For a spin-half hadron, e.g., we consider the ratio
 (0)
(B)
C↑ (τ )C↑ (τ )(B)
R (τ ) = (B)(2)∼ e−2µ|B|τ ,(0)C↓ (τ )C↓ (τ )
as a function of the applied magnetic field. Extracted
magnetic moments are shown in Fig. 1 in lattice nuclear magnetons, i.e. units of 2Me N , where MN is thelattice nucleon mass, MN ≈ 1.6 GeV. When scaled inthis fashion, results are remarkably close to experimental values. In particular, evidence for shell-model configurations suggests that this property of nuclei may
extend over a broad range of quark masses.
References
1) S. R. Beane, E. Chang, S. Cohen, W. Detmold, H.W. Lin, K. Orginos, A. Parreno, M. J. Savage, andB. C. Tiburzi, Phys. Rev. Lett. 113, 252001 (2014).
2) S. R. Beane et al. (NPLQCD Collaboration), Phys. Rev.
D 87, 034506 (2013), arXiv:1206.5219 [hep-lat].
3) W. Detmold and K. Orginos, Phys. Rev. D 87, 114512(2013), arXiv:1207.1452 [hep-lat].

Ⅱ-5. Hadron Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Nucleon structure in lattice QCD near physical mass
S. Ohta∗1,∗ 2,∗ 3 for RBC and UKQCD Collaborations
The RIKEN-BNL-Columbia (RBC) collaboration
continue numerical lattice-QCD investigations of nucleon structure1–6) . Here, I report results obtained
from ensembles7–9) generated jointly with the UKQCD
collaboration near the physical pion mass. In these
ensembles the strange quark mass is set very close to
its physical value while the degenerate up and downquark is varied toward the physical mass, resulting inpion mass ranging from about 420 to 170 MeV. Isovector observables such as vector- and axialvector-current
form factors and some low moments of structure functions are calculated.
The isovector axial charge, gA , is about the mostimportant observable concerning nucleon structure. It
determines the neutron life and pion-nucleon interaction through the celebrated Goldberger-Treiman relation. And as such it determines nuclear abundance andmuch of nuclear physics. Lattice-QCD calculations
have experienced difficulty reproducing this quantity:
they generally underestimate the experimental valueof 1.2723(23)10) . Our latest results do not escape thisproblem, as summarized in Fig. 1: About 10% deficit
1.4

experiment
I24 1.75GeV 2.71fm, 2009
I24 1.75GeV 2.71fm, AMA 2013
I+D 1.37GeV 4.61fm, 2012
I+D 1.37GeV 4.61fm, AMA 2013

1.35
1.3

gA/gV

1.25
1.2
1.15

References

1.1

1) H. -W. Lin, et al., Phys. Rev. D 78, 014505 (2008)
arXiv:0802.0863 [hep-lat].
2) T. Yamazaki et al., Phys. Rev. Lett. 100, 171602(2008) arXiv:0801.4016 [hep-lat].
3) T. Yamazaki, et al., Phys. Rev. D 79, 114505 (2009)arXiv:0904.2039 [hep-lat].
4) Y. Aoki, et al., Phys. Rev. D 82, 014501 (2010)arXiv:1003.3387 [hep-lat].
5) M. Lin, PoS LATTICE 2013, 275 (2014) arXiv:1401.1476[hep-lat].
6) S. Ohta, PoS LATTICE 2013, 274 (2014) arXiv:1309.7942[hep-lat].
7) C. Allton et al. , Phys. Rev. D 78, 114509 (2008)
arXiv:0804.0473 [hep-lat].
8) Y. Aoki et al., Phys. Rev. D 83, 074508 (2011)arXiv:1011.0892 [hep-lat].
9) R. Arthur et al., Phys. Rev. D 87, 094514 (2013)arXiv:1208.4412 [hep-lat].
10) K.A. Olive et al. (Particle Data Group), Chin. Phys.
C, 38, 090001 (2014).
11) S. Ohta, PoS LATTICE 2014, 134 arXiv:1410.8353[hep-lat].

1.05
1

0

0.1

0.2

2

0.3

0.4

0.5

0.6

2
mπ (GeV )Fig. 1. The ratio, gA /gV , of isovector axia chargel, gA ,to isovector vector charge, gV , calculated in our recent
lattice-QCD ensembles plotted against calculated pionmass squared, m2π 6)

is persistent across the mass range investigated, andpossibly worsens toward the physical mass.
Much of our efforts during the past year were concentrated in understanding this11) , starting with thelong-range autocorrelation observed at the lightestmass ensemble at pion mass mπ = 170 MeV. This ensemble is at the smallest finite-size scaling parameter,mπ L = 3.9, where L is the linear extent of the lattice
volume. That weaker but similar auto-correlation was
∗1
∗2
∗3

seen at heavier mass, mπ = 330 MeV, with the second smallest finite-size scaling parameter, mπ L = 4.6,
but not at a lighter mass of 250 MeV with larger
mπ L = 5.8, hints this autocorrelation may be related
to too small lattice volume.
We found weaker but similar autocorrelation in
isovector transversity, 1δu−δd , that differs by only
one extra Dirac γ matrix factor from the axialvector
current. This, together with the axial charge observation, suggests the virtual pion cloud around the nucleon may not be well contained within the lattice volume. The other observables, including the isovector
vector-current form factors and isovector quark momentum fraction, xu−d , and isovector quark helicity
fraction, x∆u−∆d do not show such autocorrelation
at any mass.
A possible cause for such a long-range autocorrelation is interference from the gauge-field topology thatis known to have long autocorrelation. However theaxial charge and topological charge are not found to
be correlated11) .
We also looked at how the axial charge fluctuatesspatially by dividing the volume into halves with lowerand higher x−, y−, or z−coordinates11) : we found thatit fluctuates rather wildly.
At the pion mass of about 170 MeV the virtual pion
cloud around the nucleon may not be well containedin our lattice box with linear extent of about 4.5 fm.

Institute of Particle and Nuclear Studies, KEK
Department of Particle and Nuclear Physics, SOKENDAIRIKEN BNL Research Center, BNL- 129 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-5. Hadron Physics (Theory)

Holographic heavy-quark symmetry†
K. Hashimoto,∗1,∗2 N. Ogawa,∗1 and Y. Yamaguchi∗1
Hadrons containing heavy quarks, i.e., charm andbottom quarks, have attracted much interest in hadronand nuclear physics. Accelerator experiments havefound rich spectra of heavy hadrons for conventional states, three-quark baryons and quark-antiquarkmesons, and exotic hadrons having complex structures such as multiquark states and hadronic composite states1) . Various structures of heavy hadrons are
generated by the nature of internal quark potentials
and/or hadron-hadron interactions which result fromfundamental phenomena of quantum chromodynamics(QCD).
In heavy quark sectors, a new symmetry that has
not been appeared in the light-quark sector is expected
to be important. It is called heavy-quark spin symmetry2) , and it emerges because of the suppression of
the spin-dependent interaction between quarks, whichis inversely proportional to quark masses. This symmetry leads to a specific feature: mass degeneracy ofheavy hadrons having different spins. In the case ofmesons, we find small mass splittings between spin0 pseudo-scalar mesons and spin-1 vector mesons inexperimental results, e.g., the mass splitting of BB ∗(∼45 MeV) in the bottom-quark sector is much smaller
than that of KK ∗ (∼ 400 MeV) in the strange-quark
sector. The symmetry also affects decays and productions of heavy hadrons with different spins. Hence, theheavy-quark spin symmetry plays a significant role inheavy-hadron spectroscopy.
The spectra of heavy hadrons have been studied using various theoretical approaches, such as the quark
model and lattice QCD. In addition, we found thatthe gauge/gravity correspondence3) is a promising approach because it provides powerful methods to deal
with strongly coupled theories.
The gauge/gravity correspondence has been applied
to investigate hadron spectra by introducing dynamical quarks described by excitations on probe D-branes.
For example, N = 2 hypermultiplet flavors (= quark
multiplets) added to N = 4 SU(Nc ) super Yang-Mills
theory are realized by introducing Nf probe D7-braneson the AdS5 × S5 background ( generated by Nc D3branes) on the gravity side4) . In this model, the quarks
are given as fundamental strings stretched between D3and D7-branes. The masses of pseudo-scalar and vector mesons are obtained as fluctuations of the scalarand vector fields on the flavor D-branes4) .
In the gauge theory holding supersymmetry, however, both pseudo-scalar and vector mesons are mem†

∗1
∗2

Condensed from the article in arXiv:1412.5590 [hep-th]
RIKEN Nishina Center
Department of Physics, Osaka University- 130 -

bers of the same multiplet, and the masses are completely degenerate regardless of the value of the quark
mass. Even when the supersymmetry is broken byfinite temperature, Shark-Schwartz compactification,etc, the supersymmetry is recovered in the heavyquark limit (i.e., in the UV limit) in most of the
top-down models. Hence, the presence of the heavyquark spin symmetry has not been obvious in thegauge/gravity duality. In order to determine whether
the heavy-quark spin symmetry exists, we need to investigate meson mass degeneracies in theories that are
non-supersymmetric even in the UV region.
In this study, we propose a semi-bottom-up, deformed D3-D7 model. The background geometry is
deformed from the conventional AdS5 × S5 and obtained as

 2
dr
2δ
2
2
2α
µ
ν
2 −2β
dsstr = r ηµν dx dx + R r+ r dΩ5 ,r2(1)
eφ = g0 r−4γ ,(2)in the string frame, where R corresponds to the radius of AdS5 , dΩ25 represents the metric of S 5 , and φ isthe dilaton. Here r is the non-dimensional coordinate.
The background geometry is given in the UV leading
form and generally holds no supersymmetry or conformal symmetry. We introduce 4 deformation parameters (α, β, δ, γ) for the background, but they are constrained by several conditions so that the theory would
have physically reasonable properties. The standard
D3 background corresponds to (α, β, δ, γ) = (1, 0, 0, 0).
We investigate the spectra of the pseudo-scalar andvector quarkonia at the limit mQ → ∞, computed as
the fluctuations of the fields on the flavor D7-brane
placed on this background.
We observed a slight mass difference between
pseudo-scalar and vector quarkonia, which is at most 1.5%, even in the non-supersymmetric analysis. The
mass degeneracy is found in not only ground states but
also excited states.
References
1) N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt,
G. T. Bodwin, E. Eichten, A. D. Frawley andA. B. Meyer et al.: Eur. Phys. J. C 71, 1534 (2011).
2) A. V. Manohar and M. B. Wise: Camb. Monogr. Part.
Phys. Nucl. Phys. Cosmol. 10, 1-191 (2000).
3) J. M. Maldacena: Int. J. Theor. Phys. 38, 1113 (1999)[Adv. Theor. Math. Phys. 2, 231 (1998)].
4) A. Karch and E. Katz: JHEP 0206, 043 (2002).
5) M. Kruczenski, D. Mateos, R. C. Myers, and D. J. Winters: JHEP 0307, 049 (2003).

Ⅱ-5. Hadron Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Possibility of ferromagnetic neutron matter†
K. Hashimoto∗1,∗2
Ferromagnetic order in nature always attracts interest for study as it manifests microscopic structure ofmatter and materials. Among observed magnetic ﬁelds
in nature, perhaps the strongest stable magnetic ﬁeld
is on the surface of magnetars, which goes up to 1015
[G] and more. The mechanism for generating such astrong ﬁeld is yet to be uncovered, and it is natural
to resort the origin to the high density of neutrons ofwhich the neutron stars consist. In fact, after the discovery of pulsars, the possibility of ferromagnetism atneutron stars was proposed. However, numerical simulations of neutron matter with realistic inter-nucleon
potentials have not shown the ferromagnetic phase. So
the possibility of the ferromagnetic phase at high density neutron matter, if exists in nature, waits for a newmechanism of the spontaneous magnetization.
In this paper, we study the possibility of the ferromagnetic phase at high density of neutrons, by using
the simplest but general chiral eﬀective action. Low energy dynamics of neutrons is governed by the chirally
symmetric interactions through pions and the spinmagnetic coupling with magnetic ﬁelds. Our model
consists of dense neutrons coupled with neutral pions
and magnetic ﬁelds, together with the chiral anomaly
term. These are indispensable ingredients, and we will
see the outcome for the magnetic phase from this minimal model.
The reason for choosing the neutral pion is simply
for the realization of the ferromagnetism, as other pion
condensations such as charged pion condensation havenot been shown to exhibit a ferromagnetism. In addition, with a neutral pion condensation of the form
Π0 (x) ∝ sin k · x, a neutron lattice is formed with analternating layer structure (ALS)1) , then the neutron
spins cancel each other, and macroscopic magnetization would not emerge. In this paper, instead, we analyze a neutral pion condensation of the diﬀerent form
Π0 (x) = q·x following Dautry and Neyman2) , and generalize the study to include magnetic ﬁelds and QCD
anomaly.
Our study is motivated by the earlier work3) inwhich, together with M. Eto and T. Hatsuda, the author proposed a mechanism for a ferromagnetic phaseat high density of neutrons. The mechanism utilizes
a neutral pion domain wall coupled to the magnetic
ﬁeld through the QCD chiral anomaly. A spontaneous
magnetization was shown in3) in the approximation ofa single wall and one-loop neutrons. In this paper,
we generalize the idea, and study in the simplest chiral model the Fermi energy of the dense neutrons and
†

∗1
∗2

Condensed from the article in arXiv:1412.6960
RIKEN Nishina Center
Department of Physics, Osaka University- 131 -

its back-reaction due to the pion condensation and themagnetic ﬁelds. A successive array of the domain walls
can be approximated by the linear pion condensationof Dautry and Neyman.
Let us summarize what we ﬁnd in this paper.
• Toy model of neutral fermions.
First we provide a toy model of a neutral fermion
with a Zeeman coupling to magnetic ﬁelds. Under the assumption of the spatial homogeneity, we
calculate the energy density of the ferromagnetic
phase and show that it is favored compared to theordinary fermion matter.
• Simplest chiral model and ferromagnetic order.
The toy model of the neutral fermions is the essential part of the chiral model of neutrons and pions.
We analyze the simplest chiral eﬀective model ofdense neutrons and neutral pions, together withthe magnetic ﬁeld coupling and the QCD anomaly.
We ﬁnd that the neutral pion condensation ofform proposed by Dautry and Neyman is precisely in the same place as the magnetization,
under the assumption of the spatial homogeneity. The energy density of the ferromagnetic-pioncondensation phase is lower than the ordinary
neutron matter at high density around ρ > 5ρ0where ρ0 is The generated magnetic ﬁeld is ∼ 40
[MeV] ∼ O(1017 )[G].
• Comparison to ALS.
We compare our energy density with that of theinhomogeneous ALS phase (which does not exhibit a magnetization), and ﬁnd that the ALS
phase is favored. The energy gain of the ALS isby several times greater than that of our ferromagnetic phase.
• Axial vector meson condensation.
To seek for the possibility of the ferromagnetism,
we look at the axial vector meson condensation accompanied by our model. Indeed, any axial vector
meson plays the same role as the neutral pions,and the axial vector meson condensation further
reduces the energy density of the ferromagnetic
phase signiﬁcantly.
References
1) R. Tamagaki and T. Takatsuka, Prog. Theor. Phys. 56,
1340 (1976).
2) F. Dautry and E. M. Nyman, Nucl. Phys. A 319, 323(1979).
3) M. Eto, K. Hashimoto and T. Hatsuda, Phys. Rev. D
88, 081701 (2013) [arXiv:1209.4814 [hep-ph]].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-5. Hadron Physics (Theory)

Pion and Kaon form factors in the NJL model
Y. Ninomiya,∗1 W. Bentz,∗1,∗2 and I. C. Cloët∗3
In this work we study the dressed quark mass dependence of the pion and kaon electromagnetic form factors at the quark level using the Nambu-Jona-Lasinio(NJL) model, which is a powerful chiral eﬀective quark
model of QCD1) . We choose the proper-time regularization scheme and introduce an infrared cut-oﬀ as inprevious studies2,3) in order to include one important
aspect of quark conﬁnement. In the calculation there is
one free model parameter, which we take as the dressed
light quark (u and d) mass M . The constituent quark
model suggests that M is about 0.3–0.4 GeV, and it
is often ﬁxed as 0.4 GeV in NJL model calculations.
However, in this work we show that the description of
the pion and kaon form factors, as well as other physical quantities, are sensitive to the dressed light quark
mass, and can be greatly improved if the dressed lightquark mass is taken to be M ≃ 0.25 GeV.
We ﬁrst explore the quark condensates ⟨q̄q⟩, thekaon decay constant fK , and the light (m) and strange(ms ) current quark masses using various values of the
dressed quark mass. Our results for these quantities
are shown in Table I. It is revealed that our results
for the three ratios ms /m, fK /fπ and ⟨s̄s⟩/⟨ℓ̄ℓ⟩ arein excellent agreement with recent experimental analyses and lattice QCD calculations, if the mass of the
dressed light quark is approximately M ≃ 0.25 GeV.
Therefore, it is interesting to study the pion and kaon
form factors for the case where M is assumed to besmaller than the usually adopted values.
Figs. 1 and 2 show our calculated results for the pionand kaon form factors for the case M = 0.25 GeV. In
each ﬁgure the dotted line denotes the result when thequark-photon vertex is treated as point-like (bare); thedash-dotted line includes eﬀects from the pion cloud;and the dashed line is the full result which also includes
the vector mesons contributions to the quark-photonvertex. The solid line shows the monopole functions
which are determined so as to reproduce the empiricalcharge radii. From these ﬁgures it is clear that thedata and the monopole functions can be reproduced
very well by choosing M ≃ 0.25 GeV and including
both the pion cloud and vector meson contributions.
Such good agreement can not be attained for the caseof M ≃ 0.4 GeV.

Fig. 1. Pion form factor for the case M = 0.25 GeV.

Table 1. Results for the current quark masses, kaon decay
constant and quark condensates, for various values ofthe dressed light quark mass M . Masses and fK are inunits of GeV, and quark condensates in units of GeV3 .
The model parameters are chosen to reproduce fπ =0.093 GeV, mπ = 0.14 GeV and mK = 0.49 GeV.
M
0.20
0.25
0.30
0.35
0.40
†
∗1
∗2
∗3

m
0.00410.00860.01230.01500.0168

ms
0.131
0.227
0.293
0.331
0.357

fK
0.128
0.110
0.010
0.094
0.091

⟨ ⟩
ℓ̄ℓ
−(0.275)3−(0.214)3−(0.190)3−(0.177)3−(0.170)3

Fig. 2. Kaon form factor for the case M = 0.25 GeV.
⟨s̄s⟩−(0.329)3−(0.224)3−(0.180)3−(0.159)3−(0.148)3

W.B. acknowledges support by the Grant in Aid for Scientific Research (Kakenhi) of the Japanese Ministry of Education,
Culture, Sports, Science and Technology, project no. 20168769.

References

Condensed from an article by Y. Ninomiya et al., Phys. Rev.
C 91, 025202 (2015).
Department of Physics, School of Science, Tokai University
RIKEN Nishina Center
Physics Division, Argonne National Laboratory- 132 -

1) T. Hatsuda and T. Kunihiro, Phys. Rept. 247, 221(1994).
2) W. Bentz and A. W. Thomas, Nucl. Phys. A 696, 138(2001).
3) I. C. Cloët, W. Bentz and A. W. Thomas, Phys. Lett.
B 621, 246 (2005).

Ⅱ-5. Hadron Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Chiral Magnetic and Vortical Effects at Weak Coupling
H. -U. Yee∗1,∗2
Chiral magnetic and vortical effects are parityodd transport phenomena in the hydrodynamics of aplasma of chiral massless fermions, which are macroscopic manifestations of the underlying microscopicchiral anomaly. For the plasma of a single right-handed
Weyl fermion, the chiral magnetic effect dictates a cur as
rent along an applied external magnetic field Bµ J = 4π2 B where µ is the chemical potential, and in
the case of chiral vortical effect, the vorticity of fluid × v plays a role similar to the magneticω = (1/2)∇
ω . These effects are robust
field, J = (µ2 + π 2 T 2 /3)due to the topological nature of chiral anomaly, andshould persist both in weak and strong coupling limits. Demonstrating the expected universality of these
phenomena in weak and strong coupling limits is aninteresting and non-trivial test of the topological nature of chiral anomaly. While the strong coupling limit
provided by AdS/CFT correspondence has successfully
confirmed the universality of these effects, the weakcoupling picture, albeit more intuitive, contains more
subtleties that need to be carefully taken into accounts.
In general, one can define the chiral magnetick)conductivity1) σχ (ω, k) by J = σχ (ω, k)B(ω,where (ω, k) are frequency and longitudinal momentum of the in-homogeneous time-dependent magnetic field B(ω,k). One expects the zero frequencymomentum limit of σχ (ω, k) to reproduce the topologically robust result of chiral magnetic effect,limk→0 limω→0 σχ (ω, k) = 4πµ2 . In the interactionfree limit, both diagrammatic1) and kinetic2) approaches give a result for σχ (ω, k) such thatlimk→0 limω→0 σχ (ω, k) = limω→0 limk→0 σχ (ω, k) =µ1
3 · 4π 2 , while a hydrodynamic argument indicates that
there should not be such a difference between the twolimits3) . Since hydrodynamic regime exists only in aninteracting theory, it is natural to study this issue in
an interacting theory going beyond the non-interacting
limit. In Ref.3) we showed in both kinetic and diagrammatic approaches that the above difference between two limits disappears in the presence of relaxation dynamics caused by interactions, confirming the
expectation from the hydrodynamics argument.
It is interesting to understand how chiral magnetic
and vortical effects arise in the quasi-particle pictureof kinetic theory of chiral fermions. The essential
ingredient that is responsible for chiral anomaly is
the Berry’s curvature in momentum space4,5) , b =
 p × Ap = p/2|p|3 , where Ap is the Berry’s connection∇of momentum-dependent chiral spinors. We showed inRef.6) that the quasi-particle energy in the presence of∗1∗2

Department of Physics, University of Illinois, Chicago
RIKEN Nishina Center- 133 -

 · p/2|magnetic field is dictated to be (p) = |p| − Bp|2
by Lorentz invariance where the second term is a spinmagnetic moment interaction. This term brings about
several interesting consequences. Since the equilibriump) = 1/(exp[β(p)] + 1) the distridistribution is f eq (bution becomes distorted by the magnetic field, whichcauses a net current along the magnetic field. This effect turns out to explain 1/3 of the full chiral magnetic
effect. On the other hand, the equation of motions of5)quasi-particles with the Berry’s curvature√ is given by
√
˙




Gx = ∂/∂p + (b · ∂/∂p)B where G = 1 + b · B
is the modified phase space density. The second term induces a net current along the magproportional to B
netic field even with spherically symmetric equilibrium
distribution. This contribution gives the rest 2/3 of thefull chiral magnetic effect.
Interestingly, a similar feature also exists in the chi , a deral vortical effect6) . With the fluid vorticity ω
tailed valance in the Boltzmann equation with conser = x × p + (1/2)
vation of angular momentum Lp/|p|,where the second term is the spin angular momentum, dictates the equilibrium distribution to be f eq =ω ·p1/(exp[β( − 2|p| )] + 1) , which induces a net current
proportional to ω
 : the result comprises 1/3 of thefull chiral vortical effect. From the spin-magnetic mo · p/2|ment interaction term in the energy, −B
p|2 , onecan obtain a contribution to the current by the variation of the quasi-particle action with respect to eternal gauge
which takes a form
 potential, the result of × p/(2|p|2 )). With distribution∆J = d3 p/(2π)3 (∇ffunction f = f eq ( − v · p), the resulting current alongω constitutes the rest 2/3 of the chiral vortical effect.
In space-time dimensions higher than four, there are
generalizations of chiral magnetic and vortical effects.
A weak coupling computation of them in real-timeformalism was performed in Ref.7) , which successfully
confirmed the hydrodynamics prediction in Ref.8)
References
1) D. E. Kharzeev and H. J. Warringa, Phys. Rev. D 80,
034028 (2009).
2) D. T. Son and N. Yamamoto, Phys. Rev. D 87, no. 8,
085016 (2013).
3) D. Satow and H. U. Yee, Phys. Rev. D 90, 014027(2014).
4) D. T. Son and N. Yamamoto, Phys. Rev. Lett. 109,
181602 (2012).
5) M. A. Stephanov and Y. Yin, Phys. Rev. Lett. 109,
162001 (2012).
6) J. Y. Chen, D. T. Son, M. A. Stephanov, H. U. Yee andY. Yin, Phys. Rev. Lett. 113, no. 18, 182302 (2014).
7) H. U. Yee, Phys. Rev. D 90, 065021 (2014).
8) D. E. Kharzeev and H. U. Yee, Phys. Rev. D 84, 045025(2011).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-5. Hadron Physics (Theory)

Collinear parton splitting for early thermalization and chemical
equilibration in heavy-ion collisions
A. Monnai∗1 and B. Müller∗2,∗3

∗1
∗2
∗3

RIKEN Nishina Center
Physics Department, Duke University
Brookhaven National Laboratory- 134 -

1022
10

g
g

(t =
= 0.2
0.2 fm/c)
fm/c)
ffinitinit (t
g
g
(t =
= 0.8
0.8 fm/c)
fm/c)
ff (t
g
g
ffeq
eq

10
10

ff

gg

1
1
-1
10-1
10
-2
10-2
10
-3
10-3
10
-4
10-4
10
0
0

1
1

2
2

3
3

4
4

p (GeV)
(GeV)
p

5
5

6
6

Fig. 1. Gluon distribution before and after the timeevolution compared with that in equilibrium.

2
10
102

1
1

1
1
qq

-1
10
10-1
-2
10
10-2

-1
10
10-1
-2
10
10-2

-3
10
10-3
-4
10
10-40
0

q

q
ffinit(t = 0.2 fm/c)
init (t = 0.2 fm/c)
q
q
ff (t
(t =
= 0.8
0.8 fm/c)
fm/c)
q
q
ffeq
eq

10
10

ff

gg

2
10
102

g

g
ffinit(t = 0.2 fm/c)
init (t = 0.2 fm/c)
g
g
ff (t
(t =
= 0.8
0.8 fm/c)
fm/c)
g
g
ffeq
eq

10
10

ff

High-energy heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large
Hadron Collider (LHC) are the gateway to the early
universe, where quarks and gluons are deconﬁned fromhadrons. The strong elliptic ﬂow observed suggeststhat the system is thermally equilibrated within a very
short time τth = 0.5-1 fm/c, at which point relativistichydrodynamics becomes a valid description of the bulk
medium. The mechanism that leads to the early equilibration, on the other hand, is still not well known.
A theoretical explication of the formation of a QCD
droplet is of high importance in collider physics.
In this work, we propose a phenomenological description of the local early equilibration based oncollinear parton splitting and recombination1) . Equilibration of a heavy-ion system requires (i) thermalization, (ii) chemical equilibration, and (iii) isotropization since the colliding nuclei are described as thecolor glass condensate where gluons are saturated up
to the typical momentum p  Qs 2) . Collinear splitting
introduces two low-momentum partons from a highmomentum incident parton. This is suitable for thedescription of the ﬁrst two types of equilibration because the thermal distribution has a relatively large
number of low-momentum partons. The processes weconsider are (a) splitting of a gluon into two gluons,(b) gluon emission by quarks and (c) quark-antiquark
pair production. Momentum fraction in a splitting
is governed by the parton splitting functions3) . The
rate of splitting in a dimensional analysis is given
1/2
as Γ  αs (q̂/p)1/2 , where αs is the QCD couplingand q̂ is the transport coeﬃcient for momentum diffusion. The recombination processes are introduced
phenomenologically; hence, the equations of motion for
the quark and the gluon phase-space distributions satisfy the second law of thermodynamics. The eﬀects ofelastic scattering, which creates oﬀ-shell partons, areencoded in the model via the Focker-Planck equation.
The detailed expressions of the equations of motion
can be found here1) .
We perform numerical estimations with a nonexpanding (1+1)-dimensional geometry to investigate
the qualitative properties of the equilibration model.
Figure 1 shows the gluon distribution of a pure gluon
system before and after time-evolution. The eﬀective
degrees of freedom are included in the deﬁnition of
the phase-space distribution. Here, the initial condition is a color-glass-like one where f g (p = 0)  1/αs

-3
10
10-3

1
1

2
2

3
3

p
p (GeV)
(GeV)

4
4

5
5

6
6

-4
10
10-40
0

1
1

2
2

3
3

p
p (GeV)
(GeV)

4
4

5
5

6
6

Fig. 2. (Left panel) Gluon and (right panel) quark distributions before and after the time-evolution comparedwith those in equilibrium.

and Qs  2 GeV. The system almost thermalizes at
0.8 fm/c when the initial time is 0.2 fm/c. Next, weconsider the case when Nf = 3 and obtain the gluon
and the quark distributions shown in Fig. 2. Here,the system approaches the thermalized state rather
quickly, but the eﬀective numbers of degrees of freedom remain far from those in equilibrium owing to
the slowness of the quark chemical equilibration process. For the current parameter settings, the typicaltime required for chemical equilibration is estimatedas τchem  2 fm/c. The results imply that collinear
parton splitting and recombination play an importantrole in the early-time dynamics of heavy-ion collisions,and the quark-gluon plasma at the onset of hydrodynamic evolution can be gluon-rich.
Future prospects include improvement of the model
parameters and development of a (3+1)-dimensional
numerical model for quantitative description of
isotropization in such QCD systems.
References
1) A. Monnai and B. Müller: arXiv:1403.7310 [hep-ph].
2) L. D. McLerran and R. Venugopalan: Phys. Rev. D 49,
2233 (1994); D 49, 3352 (1994).
3) G. Altarelli and G. Parisi: Nucl. Phys. B 126, 298(1977).

Ⅱ-5. Hadron Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Chemical equilibration of QCD medium for photon v2 puzzle
A. Monnai∗1

∑

dN
N
=
[1 + 2vn cos(φ − Ψn )],
dφ
2π
n=1

neq
g
n2 ,
2 q
(neq
q )
1
∂µ Ngµ = (ra − rb )ng − ra eq n2g
ng
neq
1
g
+ rb eq 2 n2q + rc nq − rc eq nq ng ,
(nq )
ng

(2)

(3)

where ra , rb , and rc are the reaction rates. Since pair
production is the only quark numbe-changing process,
†
∗1

0.2
0.2

Condensed from the article in Phys. Rev. C 90, 021901(R)(2014)RIKEN Nishina Center- 135 -

γ(eq)
vvγ22 (eq)γ(c =0.2,=0.2, cca,c=1.5)vvγ22 (c
=1.5)
a,c
b
b
γγ
v
(c =0.5,=0.5, cca,c=1.5)
v22 (c
=1.5)
a,c
b
b
γ
(c =2.0,=2.0, cca,c=1.5)vvγ22 (c
=1.5)
a,c
b
b

γ

0.15
0.15
0.1
0.1
0.05
0.05
0
0
0
0

0.5
0.5

1
1

1.5
1.5

2
2

2.5
2.5

3
3

p (GeV)
(GeV)
p

3.5
3.5

4
4

4.5
4.5

5
5

T
T

(1)

where φ is the azimuthal angle in momentum spaceand Ψn is the n-th harmonic event plane. On the other
hand, direct photon v2 is found to be a few times larger
than hydrodynamic predictions,1,2) which is recognized
as the “photon v2 puzzle.” Of direct photons, thermal photons from the QGP medium are the dominantsource of anisotropy because prompt photons from initial hard processes do not have it intrinsically.
In this work, I have considered the eﬀects of chemical equilibration in the QGP on thermal photon v2 .3)
A heavy-ion system before the collision is described as
the color glass condensate, a state of saturated gluons.
Several early equilibration models indicate that chemical equilibration is slower than thermalization.4) Thisimplies that the quark number at the onset of hydrodynamic evolution is smaller than that under equilibrium. Since photons are coupled to quarks, late chemical equilibration suppresses the emission of thermal
photons in the early stages where ﬂow anisotropy is
still small. Consequently, thermal photon v2 can become eﬀectively large owing to the contribution fromlater times.
I have developed a new (2+1)-dimensional ideal hydrodynamic model and coupled it to the rate equations
for the parton number densities. The number changing processes are (a) g ↔ gg, (b) g ↔ q q̄, and (c)q(q̄) ↔ gq(g q̄). Here, the vanishing net baryon number limit is considered. The relaxation equations are:∂µ Nqµ = 2rb ng − 2rb

0.25
0.25

vv2γ2

Discovery of the quark-gluon plasma (QGP), a deconﬁned phase of QCD, at BNL Relativistic Heavy Ion
Collider and CERN Large Hadron Collider is a milestone in hadron physics. The produced medium is considered to be strongly coupled because the momentum
anisotropy in hadronic spectra is large enough to validate hydrodynamic description. This is quantiﬁed byelliptic ﬂow v2 deﬁned as a Fourier expansion coeﬃcient of the yield N :Fig. 1. Thermal photon v2 with diﬀerent quark chemical
equilibration rates.

chemical equilibration time would be given by τchem =1/rb . Here, the rates are parametrized as ri = ci T .
The equation of state is a hyperbolic interpolation of
those for hadron and parton gases with Nf = 2. The
thermal photon emission rate is also derived from thosefor the hadron and QGP phases.
Figure 1 shows the elliptic ﬂow of thermal photons√
for Au-Au collisions at sN N = 200 GeV with theimpact parameter b = 7 fm. The chemical reaction
parameters are chosen as cb = 0.2, 0.5, and 2.0, whereca,c = 1.5. Thermal photon v2 can be visibly enhancedby late quark chemical equilibration. For the suggested
chemical equilibration time τchem = 2 fm,4) cb = 0.5
follows from T ∼ 0.2 GeV. The dependences on thegluon number-changing processes characterized withra and rc are found to be small as expected. The particle spectrum of thermal photons is not aﬀected muchby chemical non-equilibrium with the current parameter settings. This implies that late quark chemical
equilibration is important to explain the photon v2
problem. It should be noted that the mechanism canalso be an explanation to the large photon v3 recently
observed in the experiments.
Future prospects include the introduction of a dynamical equation of state, improved initial conditions,and chemical equilibration rates. Eﬀects of viscosities
would also be important in quantitative discussion because thermal photons are sensitive to early-time ﬂuid
dynamics where oﬀ-equilibrium corrections are large
because photons can pass through the QCD medium.
References
1) A. Adare et al. [PHENIX Collaboration]: Phys. Rev.
Lett. 109, 122302 (2012).
2) D. Lohner [ALICE Collaboration]: J. Phys. Conf. Ser.
446, 012028 (2013).
3) A. Monnai: Phys. Rev. C 90, 021901 (2014).
4) A. Monnai and B. Müller: arXiv:1403.7310 [hep-ph].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-5. Hadron Physics (Theory)

Refraction of light in the quark-gluon plasma
A. Monnai∗1∗1

RIKEN Nishina Center- 136 -

Fig. 1. Schematic of medium refraction for (a) elliptic ﬂow
and (b) triangular ﬂow.

0.03
0.03

promptvvγ2γ2,, prompt
(a=0)
(a=0)

promptvvγ2γ2,, prompt(a=0.5)(a=0.5)

0.025
0.025

promptvvγ2γ2,, prompt
(a=1)
(a=1)

0.02
0.02

promptvvγ2γ2,, prompt
(a=2)
(a=2)

,promptγγ,prompt
vv22

Electromagnetic probes in high-energy heavy-ion
collisions provide us with important information on thequark-gluon plasma (QGP) because experimental data
indicate that the hot medium is color opaque but electromagnetically transparent. An important discovery
regarding such probes is the excessive yield of direct
photon elliptic (v2 ) and triangular ﬂow (v3 ).1) Direct
photons consist of prompt photons created in the initial hard processes and thermal photons emitted fromthe medium. Flow harmonics is deﬁned as a Fourier expansion coeﬃcient of particle spectra in the azimuthal
angle and is induced by geometrical anisotropy in thesystem via medium interaction. Since hadronic ﬂow
harmonics follows hydrodynamic description and isconsidered as an evidence for the existence of a strongly
coupled medium, quantitative understanding of the direct photon ﬂow harmonics is an important issue inheavy-ion phenomenology.
I have investigated the eﬀect of refraction on prompt
photons by the QGP medium in the transverse plane(Fig. 1).2) The emission rate for prompt photons isderived from p-p collision data.3) The path of a ray
in a medium with the refractive index n is given as
d2 x/dτ 2 = (1/2)dn2 /dx according to Fermat’s principle. The dynamical evolution of an inhomogeneous
medium should be considered, because the typical lifetime and size of the system are comparable. Here,
I use a (2+1)-dimensional ideal hydrodynamic modelwith Monte-Carlo Glauber initial conditions and a lattice QCD equation of state. The initial time is 0.4 fm/cand the freeze-out temperature is 0.15 GeV. The temperature and frequency dependence of the refractive index is parametrized as n2 (T, ω) = 1−ωp2 /ω 2 , where theplasma frequency is parametrized as ωp2 = a2 T 2 . In thehigh-temperature limit, ωp2 ∼ m2D ∼ e2 T 2 is obtainedusing the Debye mass mD . This implies a2 ∼ 10−1
since e2 = 4παEM . The frequency ω is Doppler-shiftedfrom the original frequency as ω = ω0 /γ(1 + β cos ∆φ),
where ∆φ is the angle between the ﬂow and the direction of a ray. It should be noted that the phase velocity
in the QGP medium, vph = 1/n, exceeds the speed oflight, but causality is not violated because the groupvelocity remains smaller than unity. When n2 < 0, themedium does not bend a ray but partially absorbs it.
The elliptic ﬂow of prompt photons is shown in
Fig. 2. When there is no refraction, the quantity vanishes. For non-unity refractive indices, on the other
hand, positive v2 is observed above plasma frequencies. The magnitude, however, is not large enoughto account for the large photon v2 found in collider
experiments. Below the plasma frequency, the high-

0.015
0.015
0.01
0.01
0.005
0.005
00
00

0.5
0.5

11

1.5
1.5

pp (GeV)
(GeV)

22

2.5
2.5

33

T
T

Fig. 2. Diﬀerential elliptic ﬂow of prompt photons for different refraction parameters.

temperature region near the center of the medium becomes semitransparent and suppresses photons traveling horizontally, leading to negative v2 . Once theentire system becomes translucent at low momentum,
v2 again becomes positive because photons have betterchance of moving out of the medium in the directionof the minor axis. This implies that the QGP plasma
frequency can be constrained from measurements. The
absorptive behavior has not been found in photon pT
spectra above 0.5 GeV at RHIC and 1 GeV at LHC.4)
Here, the former condition is more stringent and the
maximum refraction parameter allowed is a2 ∼ 1-2.
Higher-order harmonics, v3 -v5 , are found to be positive but small. Note that the above argument depends
on the choice of refractive index. Numerical analyses
with diﬀerent indices and introduction of thermal photons will be performed in the future.
References
1) A. Adare et al. [PHENIX Collaboration]: Phys. Rev.
Lett. 109, 122302 (2012).
2) A. Monnai: arXiv:1408.1410 [nucl-th].
3) S. Turbide, R. Rapp and C. Gale: Phys. Rev. C 69,
014903 (2004).
4) A. Adare et al. [PHENIX Collaboration]: arXiv:1405.3940[nucl-ex].

Ⅱ-5. Hadron Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

Transverse single-spin asymmetries in proton-proton collisions andthe role of twist-3 fragmentation†
D. Pitonyak,∗1 K. Kanazawa,∗2 Y. Koike,∗3 and A. Metz∗2

†

∗1
∗2
∗3

Condensed from the article in PRD 89, 111501(R) (2014)
RIKEN Nishina Center
Department of Physics, Temple University
Department of Physics, Niigata University- 137 -

0.4
0.4

STAR 04
04
STAR
3.3 <
<η
η<
< 4.1
4.1
3.3

0

STAR 1212STARη== 3.68
3.68
η

π≠0

A
AN
N

0.2
0.2
0
0

0.2
0.2

0.3
0.3

0.4
0.4

xxFF

0.5
0.5

0.6 0.4
0.4
0.6

STAR
STAR 08
08

0.5
0.5

xxFF

0.6
0.6
π≠0

<η>
<η> =
= 3.7
3.7

<η>
<η> =
= 3.3
3.3

0.7
0.7

0

AN
A
N

0.1
0.1

0
0
-0.4
-0.4 -0.2
-0.2

0
0

xxFF

0.2
0.2

0.4
0.4

-0.6
-0.6 -0.4-0.4 -0.2
-0.2

00

xxFF

0.2
0.2 0.4
0.4 0.6
0.6

0.2
BRAHMS 07
0.1

AN

The field of transverse single-spin asymmetries(SSAs) in hard semi-inclusive processes began close to
40 years ago at FermiLab. People noticed early onthat the collinear parton model cannot generate thelarge effects that were found. It was then pointed outthat SSAs for single-particle production in hadronic
collisions are genuine twist-3 observables for which,in particular, collinear 3-parton correlations have tobe taken into account. This formalism later on was
worked out in more detail and applied to SSAs in processes like light hadron production in proton-proton
collisions, p↑ p → hX. Here we focus on SSAs in suchreactions, which have been complemented by many experiments, including those at RHIC.
For quite some time it was believed that effects
inside the transversely polarized proton dominate
the transverse SSA in p↑ p → hX (typically denoted by AN )1–4) . In particular, the so-called QiuSterman function TF was thought to be the main nonperturbative object that generates this observable. TF
can be related to the transverse-momentum dependent⊥(TMD) Sivers parton density f1T. Because of this relation, one can extract TF from data on either AN oron the Sivers transverse SSA in semi-inclusive deepinelastic scattering (SIDIS) ASiv
SIDIS . It therefore cameas a major surprise when an attempt failed to simultaneously explain both AN and ASiv
SIDIS — the two
extractions for TF actually differ in sign5) , a puzzle
that has become known as the “sign mismatch”.
At this point one may start to question the dominance of TF . In fact, data on the neutron target transverse SSA in inclusive DIS6) seem to support this pointof view7) . Therefore, we study here the potential roleof fragmentation effects, whose analytical result in thetwist-3 formalism was first worked out in 8) . It involves
the non-perturbative functions Ĥ, ĤFU , and H, where
the first is related to the TMD Collins function and thethird can be written in terms of the other two.
In Fig. 1 we show our results from fitting
the collinear 3-parton fragmentation correlator ĤFU
0±
to data for AπN from STAR9–11) and AπN from
BRAHMS12) . Our fit describes the data very well;moreover, one can see without ĤFU , one cannot obtain the rise in AN at large xF that is characteristic of the data. Therefore, we have demonstrated forthe first time that twist-3 factorization actually candescribe high-energy RHIC data for AπN if one takesπ+–πθ = 4°

θ = 2.3°

0

-0.1
0.2

0.25

0.3

xF
0

0.15

0.2

xF

0.25

0.3

±

Fig. 1. Fit results for AπN and AπN . The dashed line (dotted line in the case of π − ) means ĤFU switched off.

the fragmentation contribution into account. This
work also allows us to potentially resolve the signmismatch crisis since one does not need TF to describe
the data. Since in the twist-3 approach part of AN
can be fixed by spin/azimuthal asymmetries in SIDIS
and in e+ e− → h1 h2 X, we have shown that at present
a simultaneous description of all those observables ispossible.
References
1) J.-w. Qiu and G. Sterman, Phys. Rev. D 59, 014004 (1999).
2) C. Kouvaris et al., Phys. Rev. D 74, 114013 (2006).
3) Y. Koike and T. Tomita, Phys. Lett. B 675, 181 (2009).
4) K. Kanazawa and Y. Koike, Phys. Rev. D 82, 034009(2010); Phys. Rev. D 83, 114024 (2011).
5) Z.-B. Kang et al., Phys. Rev. D 83, 094001 (2011).
6) J. Katich, Phys. Rev. Lett. 113, 022502 (2014).
7) A. Metz et al., Phys. Rev. D 86, 094039 (2012).
8) A. Metz and D. Pitonyak, Phys. Lett. B 723, 365 (2013).
9) J. Adams et al. [STAR Collaboration], Phys. Rev. Lett.
92, 171801 (2004).
10) B. I. Abelev et al. [STAR Collaboration], Phys. Rev.
Lett. 101, 222001 (2008).
11) L. Adamczyk et al. [STAR Collaboration], Phys. Rev.
D 86, 051101 (2012).
12) J. H. Lee et al. [BRAHMS Collaboration], AIP Conf.
Proc. 915, 533 (2007).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-5. Hadron Physics (Theory)

Left-right spin asymmetries in lepton-nucleon collisions†
D. Pitonyak,∗1 L. Gamberg,∗2 Z.-B. Kang,∗3 A. Metz,∗4 and A. Prokudin∗5

†

∗1
∗2
∗3
∗4
∗5

Condensed from the article in PRD 90, 074012 (2014)
RIKEN Nishina Center
Division of Science, Penn State University–Berks
Theoretical Division, Los Alamos National Lab
Department of Physics, Temple University
Jefferson Lab- 138 -

π++
≠

0.6
0.6
0.5
0.5

Sum
Sum
F
FFT
FT
H
H
H
H
H
HFU
FU

A
ANN

0.4
0.4
0.3
0.3
0.2
0.2
0.1
0.1

00
-0.1
-0.1
00

0.1
0.1

0.2
0.2

0.3
0.3

0.4
0.4

0.5
0.5

xxHFHF

0.6
0.6≠00 Sum
π
Sum

0.4
0.4

ANN
A

The field of transverse single-spin asymmetries(SSAs) in hard semi-inclusive processes began close to
40 years ago when large effects were found at FermiLabthat could not be generated within the collinear partonmodel. Here we focus on the left-right azimuthal asymmetry that can be defined in single-inclusive leptoproduction of hadrons if the nucleon is transversely polarized, N ↑ → hX. This asymmetry is similar to thetransverse single-spin asymmetry AN that occurs inp↑ p → h X, which has been intensely studied at RHIC.
Recently, the HERMES Collaboration1) and the Jefferson Lab Hall A Collaboration2) reported the first evermeasurements of AN in lepton-nucleon scattering. In
general, one may expect that AN in this reaction could
give new insight into the underlying mechanism of AN
in hadronic collisions that is the subject of longstanding discussions.
We compute AN for N ↑ → hX in collinear factorization, where one can have twist-3 effects in the transversely polarized nucleon or in the unpolarized outgoing hadron. The former involves the so-called QiuSterman function FF T — a specific quark-gluon-quark
correlator that has an intimate connection with thetransverse momentum dependent (TMD) Sivers func⊥, while the latter arises from parton fragmention f1T
tation, specifically through the functions Ĥ, H, andĤFU , where the first is related to the TMD Collins
function. Both of these mechanisms have been studiedin p↑ p → h X within collinear factorization, e.g., in
3–6). Note that N ↑ → hX has also been computed in
the so-called Generalized Parton Model (GPM) (mostrecently in 7) ), which uses TMD parton correlation
functions.
We will estimate AN based on leading-order formulas, which we refrain from showing here explicitly forbrevity, and study the contributions from the distribution term involving FF T , and the fragmentation term
involving Ĥ, H, and ĤFU . It is important to realize that for the process at hand,  N → h X, only
the hadron transverse momentum Ph⊥ can serve as
the hard scale. Here we give a sample of our results,
namely some for HERMES and an EIC. In Fig. 1 weplot (in the top panel) AN as a function of xH
F = −xF
for π + production with 1 < Ph⊥ < 2.2 GeV (Ph⊥   1GeV)for lepton-proton collisions at HERMES energy√
S = 7.25 GeV. Also shown (in the bottom panel)is our prediction for π 0 production at EIC energy

FFT
F
FT

0.3
0.3

H
H

0.2
0.2

HFU
H
FU

H
H

0.1
0.1
00
-0.6
-0.6

-0.4
-0.4

-0.2
-0.2

0
0

0.2
0.2

0.4
0.4

0.6
0.6

xxFF

+
Fig. 1. AN as a function of xH
at HERMES
F = −xF for π
kinematics (top), and a prediction for AN as functionof xF for π 0 at EIC kinematics (bottom).

√S = 63 GeV and Ph⊥ = 3 GeV. Note that forp↑ p → π X in the forward region (xF > 0) very large
values for AN have been observed. We find that a
non-zero AN is predicted in this region at an EIC.
We see that our theoretical estimates for AN agreewith the HERMES results in sign and roughly in shape,
but in terms of magnitude they are typically above thedata. Such a discrepancy cannot be considered a failure of the collinear twist-3 formalism, but rather shows
the need for for a next-to-leading order calculation, especially in the region of lower Ph⊥ . It will also be
important to better constrain the 3-parton fragmentation correlator ĤFU through measurements, e.g., of−AπN , which might allow one to test the recent extraction of ĤFU that can play a crucial role in AN in pp
collisions6) , and to discriminate between the GPM andthe twist-3 frameworks.
References
1) A. Airapetian et al. [HERMES Collaboration], Phys.
Lett. B 728, 183 (2014).
2) K. Allada et al. [Jefferson Lab Hall A Collaboration],
Phys. Rev. C 89, 042201 (2014).
3) J.-w. Qiu and G. Sterman, Phys. Rev. D 59, 014004 (1999).
4) C. Kouvaris et al., Phys. Rev. D 74, 114013 (2006).
5) A. Metz and D. Pitonyak, Phys. Lett. B 723, 365 (2013).
6) K. Kanazawa et al., Phys. Rev. D 89, 111501(R) (2014).
7) M. Anselmino et al., Phys. Rev. D 89, 114026 (2014).

Ⅱ-5.
-5. Hadron
Hadron Physics
Physics (Theory)
(Theory)

RIKEN Accel.
Accel. Prog.
Prog. Rep.
Rep. 48
48 (2015)(2015)RIKEN

Twist-3 double-spin asymmetries in lepton-nucleon collisions†
D. Pitonyak,∗1 K. Kanazawa,∗2 A. Metz,∗2 and M. Schlegel∗3
Hadrons, the strongly interacting particles that comprise almost all of the visible matter in the universe,
have been shown to possess a complex inner-structurethat goes beyond a simple quark picture. For example,
experimental results in the 1970s on transverse singlespin asymmetries (SSAs) revealed the crucial role thatquark-gluon-quark correlations could play in hadrons.
This is a consequence of the fact that such observables are twist-3 effects. Much work over the last 40
years has been performed in the study of transverse
SSAs from both the experimental and theoretical sides.
In addition, one also has twist-3 double-spin asymmetries (DSAs), namely those where one particle islongitudinally polarized and the other is transversely
polarized. We will denote these by ALT . The classic process for which this effect has been analyzed is
ALT in inclusive deep-inelastic lepton-nucleon scattering (DIS). In that case the entire result can be written in terms of the collinear twist-3 function gT (x).
Furthermore, this asymmetry has been studied in the
Drell-Yan process involving two incoming polarizedhadrons1–4) ; in inclusive lepton production from W boson decay in proton-proton scattering5) ; for jet production in lepton-nucleon collisions6) ; and for direct
photon production7) , jet/hadron production8) , and Dmeson production9) in nucleon-nucleon collisions.
Here we consider the reaction  N ↑ → h X, where
one can have twist-3 contributions from both the distribution (incoming nucleon) and the fragmentation (outgoing hadron) sides. The leading-order (LO) analyticalformulas for these terms are new results from this work,
but we refrain from showing them explicitly for brevity.
Based on this computation we will give numerical estimates for e N ↑ → π X, where N = p, n. We will
only look at the distribution piece, where we need LO
input for the non-perturbative functions D1 (z) (unpolarized fragmentation function), g̃(x) (“worm-gear”type function), gT (x), and g1 (x) (helicity distribution),where g̃(x) is the least known of these functions andhas gained quite some interest over the years.
Since we have little information on g̃(x), we lookat two scenarios: i) using the approximate relation⊥(1)⊥g̃(x) ≈ −f1T (x), where f1T
is the Sivers function;and ii) using a Wandzura-Wilczek (WW)-type approx1
imation g̃(x) ≈ x x dy
y g1 (y), which was also used elsewhere in the literature and holds relatively well in
certain models. In both cases for gT (x) we use the1
WW approximation, gT (x) ≈ x dy
y g1 (y). In Fig. 1†

Condensed from the article arXiv:1411.6459 submitted to PLB∗1 RIKEN Nishina Center∗2 Department of Physics, Temple University∗3 Institute for Theoretical Physics, Tübingen University- 139 -

S  7.25
7.25 GeV,
GeV, P
Ph
1 GeV
GeV
S
h  1

A
ALT
LT
0.15
0.15

WW
ΠΠ� WWWWΠΠ� WW�
SiversΠΠ Sivers

0.10
0.10

SiversΠΠ� Sivers

0.05
0.05
0.1
0.6 0.5 0.4 0.3 0.2 0.1

0.0
0.0

xxFF

0.05
0.10
S
3.45 GeV,
GeV, xxFF  0.26
0.26
S 
 3.45

A
ALT
LT

WW
ΠΠ� WWΠΠ� WWWWΠΠ� Sivers
Sivers

0.2
0.2
1.0
1.0

1.1
1.1

1.2
1.2

1.3
1.3

1.4
1.4

1.5
1.5

PPh
h

ΠΠ� Sivers
Sivers

0.2
0.2
0.4
0.4

Fig. 1. ALT vs. xF for HERMES (top) and√ ALT vs. Ph⊥ for
JLab6 (bottom), where xF = 2Phz / S with Phz (Ph⊥ )the hadron’s longitudinal (transverse) momentum.

we show a sample of our results, namely for HERMES
and JLab6, where finalized data is expected soon fromboth groups.
We see from our plots that the “Sivers” input and“Wandzura-Wilczek” input can give quite different results due to the different behavior of g̃(x). Thus, evena qualitative comparison of our predictions with experiment could help distinguish between the Sivers andWW scenarios. Moreover, if the magnitude of the data
is in line with our results, one could have direct accessto the “worm-gear”-type function g̃(x), which has received some attention recently. If the magnitude is
not in agreement, this observable could give insight
into the importance of quark-gluon-quark correlationsin the nucleon and/or twist-3 fragmentation effects in
unpolarized hadrons. However, one always has to keep
in mind the potential large impact of next-to-leading
order terms. In general, we found the best chance tomeasure a nonzero asymmetry is at HERMES, JLab,and COMPASS, as the high center-of-mass energy ofan EIC leads to a very small effect. We expect thisconclusion to be rather robust.
References
1) R. L. Jaffe and X. D. Ji, Phys. Rev. Lett. 67, 552(1991); Nucl. Phys. B 375, 527 (1992).
2) R. D. Tangerman and P. J. Mulders, hep-ph/9408305.
3) Y. Koike et al., Phys. Lett. B 668, 286 (2008).
4) Z. Lu and I. Schmidt, Phys. Rev. D 84, 114004 (2011).
5) A. Metz and J. Zhou, Phys. Lett. B 700, 11 (2011).
6) Z.-B. Kang et al., Phys. Rev. D 84, 034046 (2011).
7) Z.-T. Liang et al., Phys. Lett. B 712, 235 (2012).
8) A. Metz et al., Phys. Rev. D 86, 114020 (2012).
9) Y. Hatta et al., Phys. Rev. D 88, 014037 (2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-5. Hadron Physics (Theory)

Strong binding and shrinkage of single and double K̄ nuclear systems(K − pp, K − ppn, K − K − p and K − K − pp) predicted by
Faddeev-Yakubovsky calculations
S. Maeda,∗1 Y. Akaishi,∗2,∗3 and T. Yamazaki∗2,∗4
Chiral Weak
Ansatz0-1.2

Λ(1405)
Standard Ansatz-1.3_(I=0)s KN-1.4

PDG2012

-1.5

-1.6

-1.7

10%

20%
enhanced

-50

KN
-100
DISTO

(I=0)

_
V KN

3 _(I=0)_
KKN 2V KN
3 _(I=0)
K NN _2V KN
K NNN _3V _(I=0)
2 KN

-150

-200
[MeV]
(I=0)

_
KK NN 3V KN

EnergyR KNC [fm]

2.0

R
R

1.5

NN in

NN in

K -p
p

K -K pp

K-pp
K-K-pp
K-K-p
K-p

1.0

-1.2

-1.3

-1.4

-1.5

-1.6

-1.7

_(I=0)s KN

Fig. 1. Global view of the calculated bound-state energies(upper) and sizes (lower), RKNC and RN N of K̄ nuclear
clusters as functions of the K̄N interaction strength,(I=0)
sK̄N , which is normalized so as to be -1 at the binding
threshold. The zones of the standard “Λ(1405) ansatz”(s = −1.37) and the “Chiral” ansatz (s = −1.22) are
shown by vertical broken lines. The experimental valueof the mass of K − pp as observed by DISTO7) is shownby a horizontal broken line, where a relativistic correction for the binding energy around 10 MeV is not taken
into account.

Non-relativistic Faddeev and Faddeev-Yakubovsky
calculations were made for K − pp, K − ppn, K − K − p
and K − K − pp kaonic nuclear clusters, where the quasi
bound states were treated as bound states by employ∗1
∗2
∗3
∗4

Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine.
RIKEN Nishina CenterCollege of Science and Technology, Nihon University
Department of Physics, University of Tokyo- 140 -

ing real separable potential models for the K − -K − andthe K − -nucleon interactions as well as for the nucleonnucleon interaction1) .
The binding energies and spatial shrinkages of thesestates, obtained for various values of the K̄N interaction, were found to increase rapidly with the K̄N interaction strength. Their behaviors are shown in a reference diagram, Fig. 1, where possible changes by varying the K̄N interaction in the dense nuclear medium
are given. Using the Λ(1405) ansatz with a PDG massof 1405 MeV/c2 for K − p, the following ground-statebinding energies together with the wave functions wereobtained: 51.5 MeV (K − pp), 69 MeV (K − ppn), 30.4
MeV (K − K − p) and 93 MeV (K − K − pp), which arein good agreement with previous results of variational
calculation based on the Akaishi-Yamazaki coupledchannel potential2–5) . The K − K − pp state has a significantly increased density where the two nucleons are located very close to each other, in spite of the inner N N
repulsion. Relativistic corrections on the calculated
non-relativistic results indicate substantial lowering of
the bound-state masses, especially of K − K − pp, toward the kaon condensation regime. The fact that the
recently observed binding energy of K − pp7) is muchlarger (by a factor of 2) than the originally predicted
one may infer an enhancement of the K̄N interaction
in dense nuclei by about 25%, possibly due to chiralsymmetry restoration. In this respect some qualitative
accounts are given based on ”clearing QCD vacuum”
model of Brown, Kubodera and Rho.8)
References
1) See full description: S. Maeda, Y. Akaishi and T. Yamazaki, Proc. Jpn. Acad. Ser. B 89 (2013) 418.
2) Y. Akaishi and T. Yamazaki, Phys. Rev. C 65 (2002)
044005.
3) T. Yamazaki and Y. Akaishi: Phys. Lett. B 535 (2002)
70.
4) T. Yamazaki, A. Doté and Y. Akaishi, Phys. Lett. B
587 (2004) 167.
5) T. Yamazaki and Y. Akaishi, Phys. Rev. C 76 (2007)
045201.
6) M. Agnello et al., Phys. Rev. Lett. 94 (2005) 212303.
7) T. Yamazaki et al., Phys. Rev. Lett. 104 (2010) 132502.
8) G.E. Brown, K. Kubodera and M. Rho, Phys. Lett. B
192 (1987) 273.

Ⅱ-5. Hadron Physics (Theory)

RIKEN Accel. Prog. Rep. 48 (2015)

New way to produce dense double-antikaonic dibaryon system,
K − K − pp, through Λ(1405)-doorway sticking in p + p collisions
M. Hassanvand,∗1,∗2 Y. Akaishi,∗1,∗3 and T. Yamazaki∗1,∗4
A recent successful observation of a dense and deeply
bound K̄ nuclear system, K − pp, in the p + p →K + + K − pp reaction in a DISTO experiment1) indicates that the double-K̄ dibaryon, K − K − pp, which
was predicted to be a dense nuclear system2,3) , canalso be formed in p + p collisions.

a)
p'

K+

p incident

p targetFig. 2. (Color online) Diﬀerential cross sections for various
bound-state energies, E, of the K − K − pp system for Tp= 7.0 GeV, Γ = 150 MeV, b = 0.3 fm and θ12 = 180.

X

Λ*
b)
K

+

study of the calculated eﬀects of the binding and density of K − K − pp on the cross section, we ﬁnd thatthe bound-state peak of K − K − pp dominates over the
spectrum when and only when the system is dense.
This is understood as the two Λ∗ doorway particles interact immediately within a short distance, assisted bya large momentum transfer (∼ 1.8 GeV/c) and a shortcollision length (∼ 0.3 fm), which helps to enlarge theΛ∗ − Λ∗ sticking into a dense K − K − pp system. See
details in Ref.4,5) . This mechanism is similar to thatfor a single K̄ cluster (K − pp) formation6,7) , which has
just been proven by the DISTO experiment.

Λ*K+
p targetp incidentXΛ*Fig. 1. Reaction diagrams in the center-of-mass system of
pp collisions. a) For pp → K + + K − pp and b) for
pp → K + + K + + K − K − pp. The Λ(1405) resonanceparticle as a doorway is indicated by Λ∗ .

We have formulated and calculated the diﬀerential
cross section for the formation of the simplest doubleK̄ nuclear cluster system, K − K − pp, in the reaction
processp + p → K + + K + + Λ∗ + Λ ∗ ,→ K + + K + + K − K − pp,→ K + + K + + Λ + Λ,

References
1) T. Yamazaki et al., Phys. Rev. Lett. 104 (2010) 132502.
2) T. Yamazaki, A. Doté and Y. Akaishi, Phys. Lett. B
587 (2004) 167.
3) S. Maeda, Y. Akaishi and T. Yamazaki, Proc. Jpn.
Acad. Ser. B 89 (2013) 418.
4) T. Yamazaki, Y. Akaishi and M. Hassanvand, Proc. Jpn.
Acad. Ser. B 87 (2011) 362.
5) M. Hassanvand, Y. Akaishi and T. Yamazaki, Phys.
Rev. C 84 (2011) 015207.
6) T. Yamazaki and Y. Akaishi, Proc. Jpn. Acad. Ser. B
83 (2007) 144.
7) T. Yamazaki and Y. Akaishi, Phys. Rev. C 76 (2007)
045201.

where Λ∗ is a quasi-bound K − p state corresponding
to the Λ(1405) resonance4,5) . From a comprehensive
∗1
∗2
∗3
∗4

RIKEN Nishina Center
Department of Physics, Isfahan University of Technology
College of Science and Technology, Nihon University
Department of Physics, University of Tokyo- 141 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-5. Hadron Physics (Theory)

Theoretical analysis of Λ(1405) → (Σπ)0 mass spectra
produced in p + p → p + Λ(1405) + K + reactions
M. Hassanvand,∗1,∗2 S. Z. Kalantari,∗2 Y. Akaishi,∗1,∗3 and T. Yamazaki ∗1,∗4
0.12

(b)
(d)

0.08

(a)

(c)

Σ+π- + Σ-π+

0.06

2

0.04

M=1405 MeV/c

2

b/(MeV/c )]dσ/dM [µb0.10p+Λ∗ +K + reactions, in which both the incident channel for a quasi-bound K − p state and its decay process
to (Σπ)0 were taken into account realistically1) . We
calculated M (Σπ) spectral shapes for various theoretical models for Λ∗ . They are asymmetric and skewed,
and were compared with recent experimental data of
HADES2) . The nearly isotropic proton distribution
observed in DISTO3) and HADES is ascribed to a shortcollision length in the production of Λ∗ , which justiﬁes
the high sticking mechanism of Λ∗ and the participating proton into K − pp4) .
In the present work we formulate the spectral shapeof the (Σπ)0 mass to provide theoretical guides to analyze experimental data of (Σπ)0 mass spectra fromthe above reaction. We take into account both the formation and the decay processes of Λ∗ in pp reactions
realistically, following our K̄N − Σπ coupled-channel
formalism5) . In this way, we derive the general formof the spectral function, which is not symmetric, butskewed with respect to the pole position. Then, we analyzed (Σ+− π −+ )0 spectra from HADES at Tp = 3.50
2GeV2) , and obtained: M (Λ∗ ) = 1405+11−9 MeV/c andΓ = 62 ± 10 MeV, where the interference eﬀects of theK̄N -Σπ resonance with I= 0 and 1 Σπ continuum areconsidered. Whereas the HADES spectrum shows avery broad peak centered around 1385 MeV/c2 , significantly lower lying than 1405 MeV/c2 , we have clariﬁedthat it is due to kinematical distortion. The present result on M and Γ is in good agreement with the PDG12and PDG14 values6) . The Hyodo-Weise (HW) spectra7) , shown as the curves (c) and (d) in the ﬁgure, do
not account for the experimental spectrum.

HKAY (1405), χ2 =9
PDG (1405.1), χ2=14
HW, T 21 , χ2 = 111
HW, T22 , χ2 = 39

0.02
0.00
-0.02
1300

1350

1400

1450

+

2

1500

MM(pK ) [MeV/c ]

PDG

PDG

Fig. 1. (Color online) (Upper) Comparison of HADES data
(Σ+ π − + Σ− π + , closed squares) at Tp = 3.50 GeV?)
with best-ﬁt theoretical spectral functions S(x). a)
Best-ﬁt HKAY curves (with χ2 = 9.5, M = 1405+11−9
MeV/c2 and Γ = 62 ± 10 MeV). b) AY model with
the PDG parameters (with χ2 = 14, M = 1405.1+1.3−1.0
MeV/c2 and Γ = 50 MeV6) ). The Chiral model using
HW’s T21 (with χ2 = 111, c)) and T22 (with χ2 = 40,d)). (Lower) Conﬁdence level contours from χ2 ﬁttingof the HADES data of Σ+ π − +Σ− π + at Tp = 3.50 GeV.
The PDG12 values are also shown.

We formulated the Λ(1405) (abbreviated as Λ∗ )→ (Σπ)0 invariant-mass spectra produced in p + p →
∗1
∗2
∗3
∗4

RIKEN Nishina Center
Department of Physics, Isfahan University of Technology
College of Science and Technology, Nihon University
Department of Physics, University of Tokyo- 142 -

References
1) M. Hassanvand, S.Z. Kalantari, Y. Akaishi and T. Yamazaki, Phys. Rev. C 87, 055202 (2013); Phys. Rev. C
88, 019905(E) (2013).
2) G. Agakishiev et al. (HADES collaboration), Phys. Rev.
C 87, 025201 (2013).
3) T. Yamazaki et al., Phys. Rev. Lett. 104 (2010) 132502;
P. Kienle et al., Eur. Phys. J. A 48 (2012) 183.
4) T. Yamazaki and Y. Akaishi, Phys. Rev. C 76 (2007)
045201.
5) Y. Akaishi, Khin Swe Myint and T. Yamazaki, Proc.
Jpn. Acad. B 84, (2008) 264.
6) Particle Data Group 2012, J. Beringer et al., Phys. Rev.
D 86 (2012) 010001; Particle Data Group 2014, K.A.
Olive et al., Chin. Phys. C 38, 090001 (2014).
7) T. Hyodo and W. Weise, Phys. Rev. C 77, 035204(2008).

6. Particle Physics

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)h 0  c c as a test case for quark flavor violation in the MSSM†
A. Bartl,＊1 H. Eberl,＊2 E. Ginina,＊2 K. Hidaka,＊3 ,＊4 and W. Majerotto＊2
It is very important to determine if the SM (Standard
Model)-like Higgs boson discovered at the LHC (Large
Hadron Collider) in 20121,2) is the SM Higgs boson or the
Higgs boson of New Physics. This is the most important
issue in the present particle physics world. In this reportbased on our paper3), we study the possibility that it is thelightest Higgs boson h 0 of the Minimal SupersymmetricStandard Model (MSSM), by focusing on the width of the
decay h 0  c c . We compute the decay width at a fullone-loop level in the DR renormalization scheme in the
MSSM with nonminimal Quark Flavor Violation (QFV).
We take our reference QFV scenario as shown in Table 1
in Ref.3). The main features of the scenario are: (i) it
contains large c~  ~t (scharm-stop) mixings and large QFVtrilinear couplings of squark-squark Higgs boson, and (ii) it
satisfies the strong constraints on QFV from the B meson
data, where scharm [stop] is the supersymmetry (SUSY)
partner of the charm [top] quark. In this scenario, thelightest up-type squarks u~1 and u~ 2 are strong mixtures of
,
and
the
trilinear
couplings
c~L / R - ~t000( c~L - ~t R - h , c~R - ~tL - h , ~tL - ~t R - h couplings)
are large; therefore, u~1, 2  u~1, 2  h0 couplings are large. This
leads to an enhancement of the u~1, 2 - u~1, 2 - g~ -loop vertex
correction to the decay amplitude of h 0  c c shown in
Fig. 1, where g~ is a gluino, which is a hypotheticalsupersymmetric partner of a gluon. Thus, this results in alarge deviation of the MSSM prediction for the decay width- (h0  c c ) from the SM prediction.
In Fig. 2, we show the contour plot of the deviation of the
MSSM prediction from the SM prediction  SM (h 0  c c )
uRR
uLR
uLR
uRR
  23 plane, where = 0.118 MeV in the  23
and  23
.
23
~
~
~
~
are the c R - t R and c L - t R mixing parameters,
respectively. We see that the MSSM prediction is very
uLR
uRR
sensitive to the QFV parameters  23
and  23
, and thatthe deviation of the MSSM prediction from the SM
prediction can be very large (as large as ~ 35%). We havefound that the MSSM prediction becomes nearly equal to
the SM prediction if we switch off all the QFV parametersin our reference QFV scenario.
The observation of any significant deviation of the decay
width from its SM prediction indicates new physics beyond
the SM. It is important to estimate the theoretical andexperimental uncertainties of the width reliably in order toconfirm such a deviation. The relative error of the SM
width is estimated to be ~ 6%4). The relative error of the

MSSM width is estimated to be ~ 6%3). As seen in Fig. 2,
the deviation of the MSSM width from the SM width can beas large as ~ 35%. Such a large deviation can be observed at 
a future e e collider ILC (International Linear Collider)with a CM energy 500 GeV and an integrated luminosity of1600 fb-1, where the expected experimental error of thewidth is ~ 3%5). A measurement of the width at LHC is a
hard task because of the difficulties in charm-tagging.
In this report, we have shown that the full one-loop
corrected decay width (h0  c c ) is very sensitive to the
QFV parameters in the MSSM. In a scenario with largec~  ~
t mixings, the width can differ up to ~ 35% from its
SM value. After estimating the uncertainties of the width,
we conclude that an observation of these MSSM QFVeffects is possible at ILC. Therefore, we have a good
opportunity to discover the QFV SUSY effect in this decay0h  c c at ILC.

L / R

†

Condensed from the article in Phys. Rev. D 91, 015007 (2015)
Institute for Physics, University of Vienna＊2
Institute for High Energy Physics, OEAW, Vienna＊3
Department of Physics, Tokyo Gakugei University＊4
RIKEN Nishina Center＊1

Fig. 1. Gluino-loop vertex correction to h 0  c c .

Fig. 2. Contour plot of the deviation of the full one-loop
0level MSSM width (h  c c ) from the SM widthSM0 (h  c c ) for our reference QFV scenario.
References

1) G. Aad et al.: Phys. Lett. B 716, 1 (2012).
2) S. Chatrchyan et al.: Phys. Lett. B 716, 30 (2012).
3) A. Bartl et al.: Phys. Rev. D 91, 015007 (2015).
4) L. G. Almeida et al.: Phys. Rev. D 89, 033006 (2014).
5) J. Tian and K. Fujii: Proc. EPS-HEP 2013, Stockholm, Sweden,
PoS(EPS-HEP2013)316 [arXiv:1311.6528 [hep-ph]].

- 143 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Update on lattice QCD calculation of neutral B meson mixing
in static limit of b quark
T. Ishikawa,∗1 Y. Aoki,∗2,∗1 T. Izubuchi,∗3,∗1 C. Lehner,∗3 and A. Soni,∗3 for RBC Collaboration
The Cabibbo–Kobayashi–Maskawa (CKM) matrix
is a key part of elementary particle physics, and constraints on the elements Vts and Vtd can be obtained
from B 0 − B 0 mixing, where highly nonperturbative
hadronic weak matrix elements play an essential role.
We perform simulations on this subject using static
heavy quark as the treatment of b quark.1)2) The final
values of B meson decay constants and mixing matrix
elements and ξ parameter in the static b quark limit
are summarized as
fB = 218.8(6.5)stat (16.1)sys [MeV],
fBs = 263.5(4.8)stat (18.7)sys [MeV],
fBs /fB = 1.193(20)stat (35)sys ,
fB B̂B = 240(15)stat (17)sys [MeV],
fBs B̂Bs = 290(09)stat (20)sys [MeV],ξ = 1.208(41)stat (44)sys ,

∗2
∗3





fB

f Bs






240

fBs /fB280

fB [MeV]

230

270

220

260

(4)

210

250

(5)

270
260
250
240
230
220

(6)

RIKEN Nishina Center
Nagoya University, KMI
Brookhaven National Laboratory- 144 -




fB



B B f Bs



B Bs


ξ

Fig. 1. Error budget for final quantities. The height of thebars indicates total error, whereas the relative size ofthe colors is determined by squared errors.1)

(1)
(2)
(3)

where statistical (stat) and systematic (sys) errors are
given. In Fig. 1, the error budget is presented. Amongthe uncertainties presented in Fig. 1, a large portion of
the error consists of statistical error, chiral extrapolation uncertainty, and renormalization uncertainty; it isthus important to reduce them to obtain more reliable
results.
The first step in improving the current results is
reducing the statistical errors using the All-ModeAveraging (AMA) technique.3) This involves locating many source points in the measurement but using an approximation in obtaining quark propagators
to greatly reduce computational cost. We show the
preliminary results of the AMA calculation in Fig. 2
and compare them with the current results (without
AMA). Although the AMA calculation is still ongoing,
the presented error reduction is quite encouraging.
The systematic uncertainties involve chiral extrapolation and renormalization error. For the chiral extrapolation, we are currently focusing our effort on physicalpion simulation, where we use RBC/UKQCD’s 2+1
flavor 483 × 96 domain-wall fermion ensemble. By
this calculation, most of the chiral extrapolation uncertainty is removed. Currently, the renormalization
error is large for non-ratio quantities because only oneloop perturbation is employed. We are, however, investigating a possibility of nonperturbative method forthe matching using RI/MOM scheme and coordinate
space method,4) where removing power divergence is∗1


current

AMA

1/2
fB B̂B [MeV]

current

AMA

fBs /fB

1.2
current

320
310
300
290
280
270

1.3

fBs [MeV]

current

AMA

1/2
fBs B̂Bs [MeV] 1.3

AMA

ξ

1.2
current

AMA

current

AMA

Fig. 2. Comparison of chiral and continuum extrapolated
physical quantities between current and AMA results.
The error denotes only statistical one.

essential to the existence of the static heavy quark.
Although the static limit is a good approximation
for b quark, it is known to have O(ΛQCD /mb ) ∼ 10%
uncertainty. To obtain precise results, we need to remove or reduce this uncertainty systematically. The
heavy quark expansion of a heavy-light quantity Φhl ,which has a finite asymptotic limit as mQ → ∞, iswritten as∞  ΛQCD pγpΦhl (1/mQ ) = Φhl (0) exp
, (7)
mQ
p=1
where mQ is the heavy quark mass, which is heavier
than the QCD scale ΛQCD . Our project finally includes simulations in light quark mass region (typically
c quark mass region) for obtaining expansion parameters γp s. Combining the static result with the lighter
quark mass enables us to obtain results with much lessuncertainty, where our static limit results play a crucialrole as a valuable “anchor point”.
References
1) Y. Aoki et al.: arXiv:1406.6192 [hep-lat].
2) T. Ishikawa et al.: PoS LATTICE 2013, 410 (2014).
3) T. Blum et al.: Phys. Rev. D 88, 094503 (2013).
4) K. Cichy et al.: Nucl. Phys. B 865, 268 (2012).

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Progress toward an ab initio, Standard Model calculation of direct
CP-violation in K-decays
C. Kelly∗1 for the RBC and UKQCD collaborations∗1

RIKEN Nishina Center, Brookhaven National Laboratory- 145 -

0.03

0.2

data

data

0.15

0.02

0.1
0.01

0.05
Q6

Q2

Recent theoretical and computational advances in thefield of lattice QCD have opened the door to an abinitio determination of ǫ′ , the measure of direct CPviolation in Standard Model K → ππ decays. New
sources of direct CP-violation are required to explain
the observed matter-antimatter asymmetry in the Universe, and ǫ′ is particularly sensitive to the contributions introduced by many Beyond the Standard Model
theories. A comparison of the Standard Model value
to the precisely measured experimental number may
therefore provide evidence of new physics.
In K → ππ decays, the final ππ state can have either
isospin I = 2 or 0 and ǫ′ manifests as a difference inthe complex phases of the corresponding
amplitudes,


ImA0
ImA2
′
A2 and A0 respectively: ǫ ∝ ReA2 − ReA0 .
The RBC and UKQCD collaborations have successfully performed calculations of A2 with 10% total errors1) , and only A0 remains to be determined. This issignificantly more difficult than A2 , firstly because theππ state can mix with the vacuum, leading to disconnected diagrams in which the two pions annihilate andare recreated at a later time. Such diagrams are typically extremely noisy and require advanced techniquessuch as all-to-all (A2A) propagators. The second difficulty is in creating a ππ state that is degenerate withthe kaon such that the decay occurs with physical kinematics. This requires the pions to be moving, necessitating the use of G-parity spatial boundary conditions2) (GPBC) to control the statistical noise.
Efficient use of GPBC and A2A introduces a large
number of computational challenges that must be overcome. To this end, we developed parallel code highly
optimized for the IBM Blue Gene/Q machines at BNL,
ANL and Edinburgh University and have, to date, generated O(100) independent measurements of the K →ππ amplitude. The measurements were performed ona custom generated ensemble with a (4.6 fm)3 lattice
volume and a relatively coarse 0.143 fm lattice spacing.
We use a three-flavor chiral action with degenerate up
and down quarks and a physical strange quark.
With our chosen lattice parameters we obtain a measured pion mass of mπ = 142.4(1.3) MeV and a kaon
mass of mK = 489.9(2.4) MeV, very close to their
physical values of 135 MeV and 495 MeV respectively.
We use GPBC in all three spatial directions and obtaina ππ energy of Eππ = 524(45) MeV, which agrees withthe kaon mass within errors, suggesting a near-physicaldecay.
In Fig. 1 we plot the contributions to A0 from the Q2

0

0

-0.05

-0.01

-0.1
-0.02
-0.03

-0.15
0

2

4

6
Top

8

10

12

-0.2

0

2

4

6
Top

8

10

Fig. 1.: Lattice time dependence of Q2 and Q6 , thedominant contributions to ReA0 and ImA0 respectively. The fit is shown in red.
and Q6 operators, which respectively dominate ReA0
and ImA0 . Here we use a K → ππ time separationof 12, and fit to the plateau between t = 4–8; outsideof this region the signal is contaminated by excitedstates. Our analysis also includes measurements with
K → ππ time separations of 10 and 14. Preliminary
results from our current, somewhat limited, data set
suggest a ∼50% statistical error on our result for ReA0and ∼40% for ImA0 . The error is almost completely
dominated by the disconnected diagrams, despite ouruse of A2A methods, and can only be resolved withmore statistics. We anticipate doubling the statistics
within the next 6 months.
The systematic errors on our results are dominatedby the discretization error and the error on the Wilson coefficients. The former arises because the measurement is performed on a single, coarse lattice, andis expected to be O(20%); in future calculations thiscan be removed by performing a continuum extrapolation over results computed at different lattice spacings. The Wilson coefficients are involved because wematch the low-energy lattice calculation to the threeflavor Weak effective theory where the charm has been
integrated out perturbatively; as the charm is comparatively light, it is not clear how reliable this is. We
intend to study this by comparing A0 computed using cheaper lattice calculations with stationary pions
and both three and four dynamical flavors. Ultimately
we intend to repeat the calculation with a dynamical
charm quark.
References
1) T. Blum, P. A. Boyle, N. H. Christ, J. Frison, N. Garron,
T. Janowski, C. Jung and C. Kelly et al., Phys. Rev. D
91 (2015) 7, 074502 [arXiv:1502.00263 [hep-lat]].
2) C. Kelly, PoS LATTICE 2012, 130 (2012).

12

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Collisional Energy Loss in Semi-Quark Gluon Plasma†
S. Lin,∗1 R. D. Pisarski,∗1,∗2 and V. V. Skokov∗3
Quantum chromodynamics (QCD) above the deconfinement temperature Tc is in quark gluon plasma(QGP) phase. The QGP produced in the relativistic
heavy ion collider (RHIC) and large hadron collider(LHC) remains in a temperature window Tc ∼ 2Tc
for much of its lifetime. This is a regime where
high-temperature perturbation theory becomes inappropriate. The regime is called semi-QGP, which
is characterized by a non-trivial Polyakov loop. A
matrix model with background color charges Acl
0 =i/g diag(−Q, 0, Q) has been proposed to describe thephysics in the regime1) . The background color charges
can be viewed as imaginary chemical potentials forquarks and gluons, which effectively suppress their
number density as compared to high-temperature
QGP. In this letter, we considered how the suppressionof quark and gluon number density affects heavy-quark
collisional energy loss in semi-QGP.
It is known that heavy quarks lose their energy by
Coulomb scattering and Compton scattering, in whichheavy quarks scatter off gluons and a light quarks respectively. Both processes contribute to total energy
loss. The presence of background color charges suppresses light quark and gluon number densities differently, resulting in different suppression factors forenergy loss corresponding to the two processes. For
Coulomb scattering, we found that the energy loss perunit length, to the leading logarithmic order, is given
by a Q-dependent factor S qk (Q) times the energy loss
at Q = 0:
qk
qk
dE 
dE 
qk
= S (Q).
dx Q
dx Q=0(2)

where Nf and αs are respectively the number of lightquark flavors and strong coupling constant. mD is thegluon Debye mass. S qk (Q) is the infinite sum of tracesof the Wilson
loop
 1/T
cl
L ≡ Peig 0 dτ A0 :S qk (Q) =
†
∗1
∗2
∗3

∞
4  (−)n+1
tr Ln .
π 2 n=1n2

The energy loss at Q = 0 can be expressed as follows2) :
gl





8
dE 
ET
ET
4
2
2
ln
ln
+
,
=
π
α
T
s
dx Q=0
3
m2D
27
M2
(5)
where M is the mass of heavy quark. S gl (Q) again
involves an infinite sum of traces of the Wilson loop∞
1 6  |tr Ln |2
gl
−1 .
(6)
S (Q) =
8 π 2 n=1 n2(1)

The energy loss, to the leading logarithmic order, at
Q = 0 is as follows2) :
qk


2
dE 
ET
2
2
,
= π αs T Nf ln
dx Q=09m2DThe energy loss from Compton scattering also factorizes to a Q dependent factor and the energy loss at
Q = 0 to leading logarithmic order.
gl
gl
dE 
dE 
gl
=
S
(Q)
.
(4)
dx Q
dx Q=0(3)

Condensed from the article in Phys. Lett. B, Vol.730, 236(2014)RIKEN Nishina Center
Department of Physics, Brookhaven National Laboratory
Department of Physics, Western Michigan University- 146 -

Fig. 1. Suppression factors for Coulomb scattering S qk andCompton scattering S gl .

The suppression factors S qk (Q) and S gl (Q) are both
functions of temperature through Q, whose temperature dependence is extracted from results of latticesimulation on Polyakov loop. Fig. 1 shows the plots of
S qk (Q) and S gl (Q) versus T . We found that Coulomb
scattering and Compton scattering are significant suppressed as QGP approaches Tc from temperature above
Tc . It is also noteworthy that the suppression is muchgreater for Compton scattering than for Coulomb scattering.
References
1) A. Dumitru, Y. Guo, Y. Hidaka, C. P. K. Altes
and R. D. Pisarski, Phys. Rev. D 83, 034022 (2011)[arXiv:1011.3820 [hep-ph]].
2) S. Peigne and A. Peshier, Phys. Rev. D 77, 114017(2008).

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Entropic destruction of heavy quarkonium in non-Abelian plasma
from the holographic correspondence†
K. Hashimoto∗1,∗2 and D. E. Kharzeev∗3
The studies of heavy quarkonium at finite temperature are expected to advance the understanding of
QCD plasma and to clarify the nature of the deconfinement transition. It was originally proposed1) to
use the quarkonium suppression in heavy ion collisions
as a way to detect the Debye screening in the quarkgluon plasma. The subsequent experimental studies
of quarkonium production at different energies however revealed a puzzle – the charmonium suppression
observed at RHIC (lower energy density) appearedstronger than at LHC (larger energy density). This is
in contrast to both the Debye screening scenario1) andthe thermal activation through the impact of gluons.
One possible solution to this puzzle is the recombination of the produced charm quarks into charmonia.
However, recently it was argued2) that an anomalously strong suppression of charmonium near the deconfinement transition can be a consequence of thenature of deconfinement. The argument put forward
in Ref.2 was based on the lattice QCD results indicating a large amount of entropy associated with theheavy quark-antiquark pair placed in the quark-gluon
plasma. This entropy S was found on the lattice togrow as a function of the distance L between the quark
and antiquark. The proposal of2) is that this entropy
should thus lead to the emergent entropic force
F =T

∂S
,
∂L

(1)

where T is the temperature of the plasma. It has beenfound that the balance of the attractive force from theinternal interaction and the repulsive entropic force
indicates a strong suppression of charmonium statesnear the deconfinement transition. The leading role ofthe entropic force in the deconfinement transition itself
has been conjectured, as well as a possible link of theobserved peak in the entropy near the deconfinementtransition to the “long string” condensation.
In this paper, we investigate the microscopic originof the entropy associated with the heavy quark pair in
non-Abelian plasma using the holographic correspondence (the AdS/CFT correspondence). We conclude
that the narrow and strong peak in the entropy associated with the heavy quark pair near the transition temperature is indeed related to the nature of deconfinement, and in holographic description originates
†
∗1
∗2
∗3

Condensed from the article in Phys. Rev. D90, 125012(2014)RIKEN Nishina Center
Department of Physics, Osaka University
Department of Physics and Astronomy, Stony Brook University- 147 -

from the entropy of a long fundamental string at thebottom of the confining geometry which would be absorbed into a black hole horizon after a deconfinementtransition. It is absent in the conformal N = 4 supersymmetric Yang-Mills theory, but emerges in a confining Yang-Mills theory obtained by compactification of
the fifth dimension. On the boundary, this entropy has
to be attributed to long-range, delocalized excitations
entangled with the heavy quark pair that can indeed
be described as the “long string”.
The origin of this peak in the holographic description is intriguing – it arises because the heavy quark
pair acts as an eyewitness of the black hole formationin the confining (at low temperatures) bulk geometry.
This process of black hole formation is the dual holographic representation of the deconfinement transitionon the boundary. From this viewpoint, the entropy
associated with the quark-antiquark pair is the rightquantity to detect the temperature at which the deconfinement occurs.
We also study the entropic force in holographic setup of strongly coupled gauge theories. It turns outthat the entropic force associated with the distributionof the quarks is at a sub-leading order in the strong
coupling expansion in terms of the ’tHooft coupling
constant, while the entropic force of the QCD stringis comparable to the quark-antiquark force. Howevera reasonable evaluation of the sub-leading term showsthat the Einstein entropic force increases such that thecritical distance of the quark pair to be destructed entropically is shortened.
Our proposal of using the entropy associated withthe heavy quark-antiquark pair to detect the deconfinement transition is somewhat similar to the idea ofusing the entanglement entropy as an order parameterof deconfinement. The difference is that the order parameter discussed in is the von Neumann entanglement
entropy of a spatial region with a boundary, while weconsider the Gibbs entropy. In terms of the boundary
theory, the entropy of the quark-antiquark pair likely
emerges from the entanglement of a “long string” connecting the quark and antiquark with the rest of thesystem. It would be interesting to clarify this issue
further as it may improve our understanding of both
deconfinement and confinement.
References
1) T. Matsui and H. Satz, Phys. Lett. B 178, 416 (1986).
2) D. E. Kharzeev, Phys. Rev. D 90, 074007 (2014)[arXiv:1409.2496 [hep-ph]].
3) K. Hashimoto and T. Oka, JHEP 1310, 116 (2013)[arXiv:1307.7423].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Magnetic instability in AdS/CFT : Schwinger effect andEuler-Heisenberg Lagrangian of Supersymmetric QCD†
K. Hashimoto,∗1,∗3 T. Oka,∗2 and A. Sonoda∗3
The renowned Schwinger effect1) creation process ofelectron-positron pairs in strong electric fields, is a big
challenge in the field of non-linear quantum field theory. Although the Schwinger limit E ∼ m2e has notbeen reached by the direct experiments such as strong
lasers, similar effective setups in materials are actively
investigated. Theoretical foundation of the Schwinger
effect was to evaluate the imaginary part of the effective action of QED under a constant electromagnetic field, the Euler-Heisenberg Lagrangian2) whichdates back to 1936. The Euler-Heisenberg Lagrangianis a generating function of nonlinear electromagnetic
responses of the vacuum. In its expression, the electricfield couples to the magnetic field in a complicated andnonlinear manner, and the total effective Lagrangian isa starting point in the research of strong fields in QED,
including the non-perturbative Schwinger effect.
In our previous paper3) , two of the present authors
derived an Euler-Heisenberg Lagrangian for a supersymmetric QCD in the strong coupling limit, by using
the AdS/CFT correspondence but the Maxwell electricfield) is applied, a quark antiquark pair is created. The
nontrivial part is the gluon interaction at strong coupling in QCD. The quarks are confined, and between
the quark and the antiquark a confining force (a QCD
string) is present to bind them. If the electric field isstrong enough, the quarks are liberated. This truly
nonperturbative process is of importance, not only because it can be a realistic phenomenon occurring in theuniverse, but also because it may be a touchstone forunderstanding the quark confinement.
There are at least two cases in which the QCD
Schwinger effect may play an important role: First,
the heavy ion collision experiment, and second, magnetars (neutron stars with a very strong magnetic field).
In the heavy ion collisions, very strong electric fields
are generated by the the electric current induced byheavy ions passing by each other. Since the magnetic
field is time dependent, there appears strong electricfield as well, and it may be related to the formationof the quark gluon plasma. On the other hand, magnetars are known to be the most dense place in theuniverse, and the strong magnetic field accompanied
by some electric field can occur and affect the core
structure of the stars, possibly having a quark phaseinside. In these examples, the understanding of QCD
and Schwinger effect in strong electric and magnetic
†

∗1
∗2
∗3

Condensed from the article in JHEP 1406 (2014) 085
RIKEN Nishina Center
Department of Applied Physics, University of Tokyo
Department of Physics, Osaka University- 148 -

fields can be tested by experiments/observations andserves as a playground at which we can test our theoretical knowledge on strongly coupled quantum field
theories.
The result of Ref.3) is summarized as follows; The
Euler-Heisenberg Lagrangian of strongly coupled N =2 supersymmetric QCD at large Nc limit was calculated in the presence of a constant electric field using
the AdS/CFT correspondence. Its imaginary part explicitly evaluated is found to agree with large electricfield expansion of the Schwinger effect of N = 2 supersymmetric QED (once the QCD string tension is
replaced by the electron mass). However, there, only
the electric field was considered. In this paper, we include the full dependence of the magnetic field, which
is important as is obvious from the physical situations
explained above.
Here we summarize the finding of the present paper:• We obtain the Euler-Heisenberg Lagrangian of theN = 2 supersymmetric QCD in a constant electromagnetic field, at strong coupling and large Nc
limit.
• We evaluate the imaginary part of the EulerHeisenberg Lagrangian, and find that the rate of
the quark antiquark creation diverges at zero temperature for massless quarks.
• The divergent rate can be regularized, i.e., thevacuum is unstable but the lifetime becomes finite, by either introducing finite temperature or aquark mass.
• We compute the real part of the Euler-Heisenberg
Lagrangian, and show the disappearance of
Cotton-Mouton effect in an expansion with theelectromagnetic field.
• The imaginary part of the Euler-Heisenberg Lagrangian for a small quark mass is shown to coincide with that of N = 2 supersymmetric QED, atthe leading order in electron mass. The agreement
is found also for the real parts responsible for the
Cotton-Mouton effect.
References
1) J. S. Schwinger, Phys. Rev. 82, 664 (1951).
2) W. Heisenberg and H. Euler, Z. Phys. 98, 714 (1936)
3) K. Hashimoto and T. Oka, JHEP 1310, 116 (2013)[arXiv:1307.7423].

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Turbulent meson condensation in quark deconfinement†
K. Hashimoto,∗1,∗2 S. Kinoshita,∗3 K. Murata,∗4 and T. Oka∗5
Quark conﬁnement is one of the most fundamental and challenging problems in elementary particle
physics, left unsolved. Although quantum chromodynamics (QCD) is the fundamental ﬁeld theory describing quarks and gluons, their clear understandingis limited to the deconﬁned phase at high energy orhigh temperature limits due to the asymptotic freedom. We may beneﬁt from employing a more naturaldescription of the zero temperature hadron vacuum.
A dual viewpoint of quark conﬁnement in terms of the“fundamental” degrees of freedom at zero temperature- mesons, is a plausible option.
The mesons appear in families: they are categorized
by their spin/ﬂavor quantum numbers, as well as aresonant excitation level n giving a resonance towersuch as ρ(770), ρ(1450), ρ(1700), ρ(1900), · · ·. In thisLetter we ﬁnd a novel behavior of the higher meson
resonances, i.e., mesons with large n. In the conﬁned
phase, when the deconﬁned phase is approached, we
observe condensation of higher mesons. In this state,
macroscopic number of the higher meson resonances,with a characteristic distribution, are excited. The
condensed mesons have the same quantum number
as the vacuum. The analysis is done via the anti-deSitter space (AdS)/conformal ﬁeld theory (CFT) correspondence, one of the most reliable tools to study
strongly-coupled gauge theories. By shifting our viewpoint from quark-gluon to meson degrees of freedom,
we gain a simple and universal understanding of the
conﬁnement/deconﬁnement transition, with a bonusof solving mysteries in black holes physics through the
AdS/CFT.
The system we study is the N = 2 supersymmetric SU (Nc ) QCD which allows the simplest AdS/CFT
treatment. The deconﬁnement transition is induced
by external electric ﬁelds. In static ﬁelds, the conﬁned
phase becomes unstable in electric ﬁelds stronger thanthe Schwinger limit E = ESch beyond which quarks
are liberated from the conﬁning force. We ﬁnd that
this instability is accompanied by the condensationof higher mesons. A striking feature is revealed forthe case of an electric ﬁeld quench: The kick fromthe quench triggers a domino-like energy transfer from
low to high resonant meson modes. This leads to a
dynamical deconﬁnement transition1) even below the
Schwinger limit. The transfer we ﬁnd resembles that ofturbulence in classical hydrodynamics as higher modes
†

∗1
∗2
∗3
∗4
∗5





















Fig. 1. Turbulent behavior of mesons toward deconfinement. The horizontal axis is the meson resonance leveln, and the vertical axis is the meson energy. m is thequark mass, and t is time measured after the electricfield quench. It shows a power-law behavior turned
from an exponential behavior, which is a turbulence.

participate; thus we call it a “turbulent meson condensation” and suggest it being responsible for deconﬁnement. See Fig.1.
We remind that the N = 2 theory is a toy model:
The meson sector is conﬁned and has a discrete spectrum while the gluon sector is conformal and is always
deconﬁned. Here, we concentrate on the deconﬁnement of heavy quarks and not the gluons. Note thatthe mesons with low spins in this theory are describedby a conﬁning potential and an eﬀective QCD string
exists, whereby we deﬁne our “quark conﬁnement”.
The higher meson resonances are naturally interpreted as long QCD strings, therefore our ﬁnding is
consistent with interpreting deconﬁnement as condensation of QCD strings2) . Under the condensation, aquark can propagate away from its partner antiquark
by reconnecting the bond QCD string with the background condensed strings. The gravity dual of the deconﬁned phase is with a black hole, so given the relation with long fundamental strings, our result may
shed light on the issue of quantum black holes; In particular, our time-dependent analysis gives a singularity
formation on the ﬂavor D-brane in AdS, a probe-braneversion of the Bizon-Rostworowski turbulent instability in AdS geometries3) .
References
1) K. Hashimoto, S. Kinoshita, K. Murata and T. Oka,
arXiv:1407.0798 [hep-th].
2) A. M. Polyakov, Phys. Lett. B 72, 477 (1978).
3) P. Bizon and A. Rostworowski, Phys. Rev. Lett. 107,
031102 (2011) [arXiv:1104.3702 [gr-qc]].

Condensed from the article in arXiv:1408.6293
RIKEN Nishina Center
Department of Physics, Osaka University
Osaka City University Advanced Mathematical InstituteKeio University
Department of Applied Physics, University of Tokyo- 149 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Meson turbulence at quark deconfinement from AdS/CFT†K. Hashimoto,∗1,∗2 S. Kinoshita,∗3 K. Murata,∗4 and T. Oka∗5
How the quarks are conﬁned at the vacuum of quantum chromodynamics (QCD) is one of the most fundamental questions in the standard model of particle
physics. We would like to ﬁnd a universal feature of
the deconﬁnement. To understand the nature of thequark conﬁnement, we need a proper observable which
exhibits a universal behavior irrespective of how webreak the conﬁnement. In this paper, we propose auniversal behavior of resonant mesons and name it meson turbulence.
Following our previous paper1) , we ﬁnd that a particular behavior of resonant mesons (excited states ofmesons) can be an indicator of the deconﬁnement. The
meson turbulence is a power-law scaling of the resonant meson condensations. For the the resonant meson level n (n = 0, 1, 2, · · ·), the condensation of themeson ⟨cn (x, t)⟩ with its mass ωn causes the n-th meson energy εn scaling as (ωn )α with a constant power
α. This coeﬃcient α will be unique for a given theory,and does not depend on how one breaks the conﬁnement. In particular, for the theory which we analyze inthis paper, that is N = 2 supersymmetric QCD with
N = 4 supersymmetric Yang-Mills as its gluon sector
at large Nc at strong coupling, the universal power-law
scaling parameter α is found to be⟨εn ⟩ ∝ (ωn )α ,α = −5 .

(1)

where εn is the energy of the n-th meson resonance.
Normally, for example at a ﬁnite temperature, the energy stored at the n-th level of the resonant meson
should be a thermal distribution, εn ∝ exp[−ωn /T ].
The thermal distribution is Maxwell-Boltzmann statistics, in which the higher (more massive) meson modes
are exponentially suppressed. However, we conjecturethat this standard exponential suppression will be replaced by a power-law near any kind of the deconﬁnement transitions. If we think of the meson resonantlevel n as a kind of internal momentum, then the energy ﬂow to higher n can be regarded as a so-called
weak turbulence. This is why we call the phenomenon
meson turbulence, and the level n can be indeed regarded as a momentum in holographic direction in the
AdS/CFT correspondence.
The reason we came to the universal power behavior
is quite simple. We combined two well-known things,
†

∗1
∗2
∗3
∗4
∗5

• Mesons are excitations of an open QCD string.

Fig. 1. A schematic picture of the deconfinement phase ascondensation of QCD strings. Left: we add a meson (apair of a quark and an anti-quark connected by a QCD
string) to the system. Right: due to the backgroundcondensed QCD strings, the QCD string can be reconnected, and the quark can freely propagate away fromthe anti-quark.

• Deconﬁnement phase is described by a condensation of long strings.
Combining these two leads us to the conjecture that thedeconfinement of quarks is indicated by a condensationof higher meson resonances. More precisely, we claimthat the condensation should be turbulent: the higher
mode condensation is not suppressed exponentially but
behaves with a power-law.
We shall investigate various deconﬁning transitionsin this paper, to check the universality of our conjecture of the meson turbulence. First, we work with astatic case. A nonzero electric ﬁeld is a good example since a strong electric ﬁeld can make the quarkantiquark pair dissociate. Then we investigate timedependent setup. The virtue of the AdS/CFT correspondence is that time-dependent analysis is possible,
as opposed to lattice simulations of QCD. To demonstrate the universality of the meson turbulence, we
work in two examples: (1) electric-ﬁeld quench, and(2) quark-mass quench. In all cases, we ﬁnd numerically the meson turbulence and the universal powerlaw with the power α = −5.

The universality we found in this paper strongly indicates that the meson turbulence is a universal phenomena which is independent of how one breaks the
conﬁnement.
References
1) K. Hashimoto, S. Kinoshita, K. Murata and T. Oka,
arXiv:1408.6293 [hep-th].

Condensed from the article in arXiv:1412.4964
RIKEN Nishina Center
Department of Physics, Osaka University
Osaka City University Advanced Mathematical InstituteKeio University
Department of Applied Physics, University of Tokyo- 150 -

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Electromagnetic instability in holographic QCD†
K. Hashimoto,∗1,∗3 T. Oka,∗2 and A. Sonoda∗3
Schwinger effect2) is one of the most interesting phenomena in particle physics. This is a phenomenon thata pair creation of charged particles occur under an external field such as an electromagnetic field. Schwinger
obtained the creation rate of an electron positron pairby evaluating the imaginary part of Euler-Heisenberg
Lagrangian1) , which is an effective Lagrangian for aconstant  electric field.
This rate Γ is derived asΓ ∼ exp −πm2e /eE to leading order and has a form
with a negative power in the gauge coupling e. So the
Scwinger effect is a non-perturbative effect. Here, meis the electron mass and E is an electric field. A criticalelectric field necessary energy for the electron positronpair creation is Ecr ∼ m2e c3 /eh̄, and the strength isabout 1018 [V/m]. So, it is a phenomenon which shows
up only under strong electromagnetic fields.
Recently, we have seen advance in research on astrong electromagnetic field in both theoretical and experimental aspects of hadron physics. At the heavy ion
collision in RHIC and LHC, it is expected that a strong
magnetic field is generated by a collision of charged
particles accelerated at about the speed of light.
Within the AdS/CFT framework, the quark paircreation rate in the strongly coupled N = 4 supersymmetric Yang-Mills theory was obtained in3) . On
the other hand, two of the present authors obtained
the vacuum decay rate, which can be identified as thecreation rate of quark-antiquark pairs, in N = 2 supersymmetric QCD(SQCD) by using a different method4)
in AdS/CFT correspondence: the imaginary part ofthe probe D-brane action. D3-D7 brane system corresponds to N = 4 supersymmetric SU (Nc ) Yang-Mills
theory including an N = 2 hypermultiplet in the fundamental representation of the SU (Nc ) gauge group.
They obtained the creation rate of the quark antiquarkin the N = 2 SQCD under a constant electric fieldby evaluating the imaginary part of the D7-brane action. Then, the present authors evaluated the imaginary part of the D7-brane action including not only
a constant electric field but also a constant magnetic
field and obtained the creation rate of the quarks andantiquarks in the N = 2 SQCD5) .
We summarize the properties of the creation rate
in both electric and magnetic fields obtained in5) for
N = 2 SQCD as follows. We derived the EulerHeisenberg Lagrangian for a constant electromagnetic
field in N = 2 SQCD at large Nc and at strong coupling. Then, we obtained the creation rate of thequarks and antiquarks by evaluating the imaginary
†

∗1
∗2
∗3

Condensed from the article in arXiv:1412.4254
RIKEN Nishina Center
Department of Applied Physics, University of Tokyo
Department of Physics, Osaka University- 151 -

part of the Lagrangian. We found that the creation
rate diverges at a zero temperature in the massless
quark limit while it becomes finite when we introduce
a nonzero temperature. The divergence of the creation
rate is influenced not only by a constant electric field
but also by a constant magnetic field. The results in
SQCD showed similarities with the creation rate of
the electron positron pair in N = 2 supersymmetric
QED(SQED) in constant electromagnetic field.
In this paper, we study the quark antiquark paircreation in non-supersymmetric QCD at large Nc atstrong coupling, and the imaginary part of D8-braneaction in a constant electromagnetic field. The holographic models are the Sakai-Sugimoto model6) and
its deformed version. Our findings in this paper are as
follows:• We derive the Euler-Heisenberg Lagrangian for
confining gauge theories: the Sakai-Sugimotomodel and the deformed Sakai-Sugimoto model.
We obtain the creation rate of the quark antiquark
pair under the electromagnetic field, by evaluating
the imaginary part of the D-brane actions.
• The imaginary part is found to increase with themagnetic field parallel to the electric field, while
it decreases with the magnetic field perpendicular
to the electric field. So the vacuum instability
strongly depends on the direction of the appliedmagnetic field relative to the electric field.
• We obtain a critical value of the electric field, i.e.,
the Schwinger limit, by using the condition thatthe D-brane action has the imaginary part. In
the case of the Sakai-Sugimoto model, the criticalelectric field corresponds to a QCD string tension
between a quark and an antiquark.
As for the first part among above, a result with only
an electric field was reported in Ref. 7). We analyze
generic electric and magnetic fields in this paper.
References
1) J. S. Schwinger, Phys. Rev. 82 (1951) 664.
2) W. Heisenberg and H. Euler, Z. Phys. 98 (1936) 714[physics/0605038].
3) G. W. Semenoff and K. Zarembo, Phys. Rev. Lett. 107(2011) 171601 [arXiv:1109.2920 [hep-th]].
4) K. Hashimoto and T. Oka, JHEP 1310, 116 (2013)[arXiv:1307.7423].
5) K. Hashimoto, T. Oka and A. Sonoda, JHEP 1406
(2014) 085 [arXiv:1403.6336 [hep-th]].
6) T. Sakai and S. Sugimoto, Prog. Theor. Phys. 113(2005) 843 [hep-th/0412141].
7) K. Y. Kim, S. J. Sin and I. Zahed, JHEP 0807, 096(2008) [arXiv:0803.0318 [hep-th]].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Electric Field Quench in AdS/CFT†K. Hashimoto,∗1,∗2 S. Kinoshita,∗3 K. Murata,∗4 and T. Oka∗5
In this paper, we analyze response of the strongly
coupled gauge theory against an electric ﬁeld quench,by using the AdS/CFT correspondence. The system is
N = 2 supersymmetric QCD with N = 4 super YangMills as a gluon sector, and has a conﬁning spectrum
for the meson sector (while the gluon sector is always
deconﬁned). We turn on the electric ﬁeld in a timedependent manner, and ﬁnd that the system develops
to a deconﬁnement phase of mesons.
We study time-dependent behavior of various observables such as electric current carried by the quarks
and the quark condensate. We deﬁne the thermalization time scale and the deconﬁnement time in termsof the gravity dual side: the thermalization is with the
Hawking temperature, and the deconﬁnement is withthe strong redshift.
Among our ﬁndings, the most interesting is the factthat the deconﬁnement transition of the mesons occurs even with a small electric ﬁeld once it is applied
time-dependently. In the static electric ﬁeld, there exists a critical value of the electric ﬁeld beyond which
the electric current ﬂows and the system is deconﬁned.
In our time-dependent quench, if the quench is madesuﬃciently fast, even with a ﬁnal electric ﬁeld whichis smaller than the critical value, the system goes toa deconﬁnement phase — there appears a strong red
shift region in the gravity dual.
In the dual gravity picture, this phenomena can beunderstood as the D-brane version of the weakly turbulent AdS instability. The wave packet on the D-brane
is getting sharp as time increases and, eventually, collapses into the naked singularity. Accordingly, we also
found a curious behavior of the deconﬁnement time —the time scale when a strong redshift region appearson the D7-brane. The deconﬁnement time takes only
discrete values.
Furthermore, the potential implication of thepresent study of nonequilibrium dynamics in QCD
to strongly correlated electron system is suggestive.
Then, it is tempting to speculate that the formation of
naked singularity explained in the previous section isan indication of the “meson Mott transition”, i.e., theQCD version of the exciton Mott transition. We plot aschematic phase diagram obtained by this analogy in
Fig. 1 with three regions (i), (ii), and (iii).
(i) Confinement phase with coherent oscillation. When the ﬁeld is weak, the system is always
†

∗1
∗2
∗3
∗4
∗5

Condensed from the article in JHEP 1409 (2014) 126
RIKEN Nishina Center
Department of Physics, Osaka University
Osaka City University Advanced Mathematical InstituteKeio University
Department of Applied Physics, University of Tokyo

Ef

Ef
pair creation

QCD Schwinger limit(critical field)(iii) Deconfined nonequilibrium phase(ii) Transient deconfined state

Ef

on”

nsiti

t tra

ot
on M

s

“me

screeningEfcoherent oscillation of
vacuum polarization(i) Confinement phase∆V
Fig. 1. Schematic ”dynamical phase diagram” of states realized in the present study by a static electric field Ef
following an initial ramp (parametrized by the time parameter ∆V ). See text for details.

in the conﬁnement phase. However, when the ramp
speed is fast (small ∆V ), the ﬁeld induces a coherent
oscillation of vacuum polarization due to meson excitation.
(ii) Transient deconfined phase (“meson Mott
transition”). This is the speculated “meson Mott
transition” regime. When the meson amplitude becomes large, the conﬁnement force becomes relatively
weak due to screening. The quarks become liberated
and deconﬁnement takes place in the meson (quark)sector.
(iii) Deconfined nonequilibrium phase above
QCD Schwinger limit. When the electric ﬁeld
is stronger than the conﬁning strength (= QCD
Schwinger limit), the conﬁnement phase becomes unstable against direct pair creation of quark and antiquarks.1) . This state is a static nonequilibrium phasewith ﬁnite current.
In summary, by studying the dynamics of supersymmetric QCD in strong electric ﬁelds, we observed many
interesting, and universal nonequilibrium physics. Ourﬁnding implies similarities between possible formation
mechanism of quark gluon plasma in heavy ion collision experiments to laser induced phase transitions
in condensed matter, which helps us understand thephysics more deeply.
References
1) K. Hashimoto and T. Oka, JHEP 1310, 116 (2013)[arXiv:1307.7423].

- 152 -

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Holographic entanglement and causal shadow
in the time-dependent Janus black hole†
Y. Nakaguchi,∗1,∗2 N. Ogawa,∗3 and T. Ugajin∗4
The relation between entanglement and the blackhole interior has been attracting attention recently.
For eternal AdS black holes, some interior information
is captured by the entanglement entropy of an intervalon the dual theory, i.e. a thermofield doubled CFT1) .
In some kinds of black holes, the interior appears
even more difficult to access since they have “causal
shadow” regions inside. In this work, we consider
one such black hole, called the three-dimensional timedependent Janus black hole2) ,


r02
2
2
+
dθ
)
,
ds2 = L2 dy 2 +(−dtg̃(y)2 cosh2 r0 t

2

,
(1)
g̃(y) =
1 + 1 − 2γ 2 cosh 2ywhere γ is a deformation parameter from the BTZ
black hole. This is a solution of the Einstein-scalar
theory and it corresponds to a pair of two entangled
2D CFTs, whose coupling constants are different fromeach other.
This geometry has a horizontally extended Penrose
diagram as shown in Fig. 1. The remarkable property of this geometry is the existence of a so-called“causal shadow region,” which is causally inaccessible
from both boundaries.

glement entropy in this system in a holographic manner, by using the Ryu-Takayanagi formula. As in the
BTZ black hole, there are two candidate extremal surfaces in the bulk, whose area gives the entanglement
entropy. One of the extremal surfaces, which we callthe connected surface, connects two asymptotic boundaries and probes the black hole interior. The other extremal surface, which we call the disconnected surface,localizes near each of the asymptotic boundaries.
In the Janus black hole, when the deformation fromthe BTZ black hole is not so large, we found a similar behavior but with the critical time tc shorter thanthat of the BTZ black hole. Roughly speaking, this isbecause the deformation makes the wormhole region
longer and results in a longer connected surface. The
results for the time evolution of the entanglement entropy of each phase are plotted in Fig. 2.
In addition, we also found that with a sufficiently
large deformation, the disconnected surface is always
dominant, and that the holographic entanglement entropy is already proportional to the size of the subsystem from the initial time. This means that the entanglement entropy of this subsystem does not probe theblack hole interior.

At,Θ 5
11.0
10.5

t
+∞

10.0

EH

tu

+∞

fu

−∞

Γ 2  0.3
Adc Numerical
Early approx. tΘ
Late approx. Θt

9.5

re

AH

9.0

y

pa

OΓ 2 
Ac

st

8.5

EH
8.0

−∞
Fig. 1. Penrose diagram of the 3D time-dependent Janus
black hole. The causal shadow is painted yellow. The
apparent horizons (green line) in the time slices τ =const. are located inside the future event horizon.

We studied the time-evolution of the same entan†

∗1
∗2
∗3
∗4

0

2

4

6

8

t

Fig. 2. The time t dependence of the extremal surface area
A for a subsystem θ = 5, in the disconnected phase(black dotted line, numerically obtained) and in theconnected phase (gray line).

References

Condensed from the article arXiv:1412.8600 [hep-th].
Institute for the Physics and Mathematics of the Universe,
University of Tokyo
Department of Physics, University of Tokyo
RIKEN Nishina Center
Kavli Institute for Theoretical Physics, University of California- 153 -

1) T. Hartman and J. Maldacena, JHEP 1305 (2013)
014, [arXiv:1303.1080].
2) D. Bak, M. Gutperle, and S. Hirano, JHEP 0702
(2007) 068, [hep-th/0701108].
3) D. Bak, M. Gutperle, and A. Karch, JHEP 0712
(2007) 034, [arXiv:0708.3691].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Radion stabilization in the presence of Wilson line phase†
Y. Abe,∗1 T. Inami,∗2∗3 Y. Kawamura,∗1 and Y. Koyama∗4
In a higher-dimensional gravity theory, a scalar ﬁeld
ϕ called “radion” appears in the extra-dimensional
graviton components, and its vacuum expectation
value is related to the size of the extra space. The stabilization of the radius is crucial for the solution to thehierarchy problem in the Randall-Sundrum model1)
and inﬂation based on the radion2) . The stabilizationis realized by the quantum eﬀects of a graviton andfermions in a 5D model M4 × S 13) .
In a higher-dimensional gauge theory, the extradimensional components of gauge bosons are massless at the tree level because of gauge invariance, andFig. 1. The potential V (ϕ, θ) with c1 = 1, c2 = 4, m =their zero modes become dynamical degrees of freedom
1×1010 GeV, µ = 1×1010 GeV and L = 3×10−17 GeV−1 .
called the Wilson line phases θ and are stabilized byquantum corrections4) . There is a possibility that realistic gauge symmetries including the standard model
than c1 +2 and the radion is stabilized at a certain ﬁnite
ones survive after the stabilization of the Wilson line
value of ϕ. A typical shape of V (ϕ, θ) is depicted inphases. The Wilson line phase receives ﬁnite radiative
Fig. 1. From this ﬁgure, we see that the true minimum
corrections in its mass and can play the role of theof the potential is located on the line θ = π. The values
Higgs boson5) , providing a solution to the gauge hierof ϕ and the potential at the minimum depend on thearchy problem. An inﬂation model has been proposedparameters m, µ and L. Their values do not drastically
based on the idea that the Wilson line phase becomesmodify the shape of the potential drastically.
the inﬂaton6) .
In this work, we investigated the behavior of the
We investigate how the Wilson line phase and thepotential for both large and small values of the radion
Casimir energy from various bulk ﬁelds are involved
and found that the potential does not have a ﬁnite
in the stabilization of the radion in a diﬀerent setup.
minimum in the case with only charged fermions as
Particularly, we study the stabilization of the extramatter ﬁelds. The radion stabilization is realized in1dimensional radius of S in the presence of a Wilson
the presence of neutral fermions whose number is larger
line phase of the extra U (1) gauge symmetry in 5D
than the number of charged ones by two.
space-time with a ﬂat background metric and without
The remaining subject is the application of our pobranes, by using the eﬀective potential V for ϕ and θ
tential V (ϕ, θ) to an inﬂation model. By identiﬁng theat the one-loop level.
extra-dimensional scalar component of the 5D gauge
Our model consists of the 5D graviton ĝM N , aﬁeld and/or the scalar component of the 5D metric as
U (1) gauge boson BM , c1 charged fermions ψi (i =the inﬂaton, we examine whether the potential repro1, · · · , c1 ), and c2 U (1) neutral fermions ηl (l =duces realistic inﬂation parameters. The radion prop1, · · · , c2 ). We take M 4 × S 1 as the background 5D
erties diﬀer from thoset of the Wilson line phase.
space-time and impose periodic boundary conditions
on every ﬁeld. We obtain the one-loop potential
[
]
1/3
1/3
1/3
6 1
3 1
1
V (ϕ, θ) = − 2 2 4 ζ(5) + c2 2 2 4 Li5 (e−Lµϕ ) + Lµϕ1/3 Li4 (e−Lµϕ ) + L2 µ2 ϕ2/3 Li3 (e−Lµϕ )
π ϕ L
π ϕ L
3
[
]
1/3
1/3
1/3
3 1
1
+c1 2 2 4 Re Li5 (e−Lmϕ eiθ ) + Lmϕ1/3 Li4 (e−Lmϕ eiθ ) + L2 m2 ϕ2/3 Li3 (e−Lmϕ eiθ ) , (1)π ϕ L
3Referenceswhere L, m and µ are the compactiﬁcation circumfer1) L. Randall and R. Sundrum: Phys .Rev. Lett. 83, 3370
ence, the mass of the charged fermions and the neutral(1999).
fermions, respectively.
2) A. Mazumdar: Phys. Lett. B469, 55 (1999).
3) Y. Fukazawa, T. Inami, and Y. Koyama: Prog. Theor.
The potential has a ﬁnite minimum in the presence
Exp. Phys. 2013 021B01 (2013).
of neutral fermions the number c2 of which is larger
†

∗1
∗2
∗3
∗4

Condensed from the article in PTEP 2014 7, 073B04(2014).
Department of Physics, Shinshu University
RIKEN Nishina Center
Department of Physics, National Taiwan University
Department of Physics, National Tsing Hua University- 154 -

4) Y. Hosotani: Phys. Lett. B126, 309 (1983).
5) H. Hatanaka, T. Inami, and C.S. Lim: Mod. Phys.
Lett. A13, 2601 (1998).
6) N. Arkani-Hamed, H.-C. Cheng, P. Creminelli, and
L. Randall: Phys. Rev. Lett. 90, 221302 (2003).

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Is cosmological constant screened in Liouville gravity with matter?
T. Inami,∗1,∗2 Y. Koyama,∗3 Y. Nakayama,∗4 and M. Suzuki∗5,∗6
Recent observation of dark energy in our universe
has led to the conviction that the cosmological constant Λ has an inﬁnitesimal positive value. It meansthat our space-time is de √Sitter (dS) space with the
Hubble constant H being Λ. It has been proposedthat the strong infrared (IR) divergence property ofquantum corrections on dS space may explain thesmallness of Λ in our current universe (so called cosmological constant problem). The Einstein equation describes the relation between the space-time Ricci tensor Rµν and the energy momentum (EM) tensor Tµν
due to the presence of matter. In vacuum, where Tµν is
proportional to the metric, the Einstein equation takes
the formκ1Rµν − gµν R + gµν Λeﬀ = 0, Λeﬀ = Λ − Tρ ρ , (1)2D
where R is the scalar curvature, κ = 8πG with G being
Newton’s constant. The vacuum contribution of Tµν
is now combined with Λ to deﬁne the eﬀective cosmological constant Λeﬀ .
In view of this expression, we may wonder if a large
value of Tµν cancels the large value of Λ, yielding a very
1 We study
small value of Λeﬀ that we observe today.?)
this question in 2-dimensional (2D) Liouville gravity.
We are interested in the dS solution of Liouville gravity, which can describe the interaction between scaler
ﬁeld and gravity. The 2D cosmological constant has
two components: the coupling of the Liouville potential and the trace of the EM tensor. By using Weyltransformation to 2D metric gµν (gµν = e2φ ĝµν ), we
obtain the equation,
SL+mat[∫ [Φ, φ]√1 µνQĝ ∂µ Φ∂ν Φ += − d2 x −ĝ
R̂Φ
4πb2
4πb
]
1
Λ
(2)
+ e2Φ + ĝ µν ∂µ φ∂ν φ + e2Φ V (φ) .
κ2

The ﬁrst three terms are Liouville gravity. At thispoint, it is important to note that the negative valueof Λ corresponds to dS space in Liouville gravity.
As a concrete matter Lagrangian, we have studied amassless scalar ﬁeld theory with λφ4 interaction minimally coupled to Liouville gravity.

∗1
∗2
∗3
∗4
∗5
∗6

√
√
1
1
L = − g µν ∂µ φ∂ν φ −g − λφ4 −g + ∆L,
2
4!

(3)

RIKEN Nishina Center
Department of Physics, National Taiwan University
Department of Physics, National Tsing-Hua University
Walter Burke Institute for Theoretical Physics, California
Institute of Technology
Department of Physics, Shizuoka University
Department of Information Science and Technology, Graduate School of Science and Technology, Shizuoka University

λ

λ
x

λ

λ

x

z

z
b1

b2

Fig. 1. Part of λ2 -order corrections to the EM tensor Tµν.

where ∆L consists of counter-terms. In dS space, themassless scalar propagator contains IR divergence inthe long wavelength limit and the IR logarithm appears because the cutoﬀ regularization of the IR di2-4 we havevergence. Based on the in-in formalism,?,?,?)
computed the VEV of the EM tensor to the order ofλ2 .
Λeﬀ ∼ Λ + (Weyl anomaly) ++κλln2 a(η)
32π 2

κλ2
1
ln4 a(η),
8π (4π)2 H 2

(4)

1
1 −Ht
is the scale factor and η = − Hewhere a = − Hηis conformal time. The resulting VEV has time dependence through the IR logarithms, and as a consequence, the eﬀective cosmological constant shows thescreening eﬀect at late time such that the absolutevalue decreases with time. This should be in contrast
with the situations where D > 2, in which the cosmo5
logical constant is anti-screened in the λφ4 theory.?)
To claim that the observed dS breaking eﬀects are
physical, we need to ﬁnd whether they may be eliminated from the local counter-terms. Here, we discussrather unfamiliar time-dependent IR counter-terms.
This possibility plays a crucial role to understand the(in)equivalence between the Sine-Gordon model andthe massive Thirring model in dS space. We are indeed able to recover the dS invariance by adding timedependent IR counter-terms to the naive perturbative computations using the dS breaking propagator.
Within the perturbation theory we have studied, however, a similar mechanism does not seem to be workable in λφ4 theory. This fact supports the claim thatthe observed screening mechanism of the cosmologicalconstant should be physical. This sensitive issue will
be further discussed in our future publication.

References- 155 -

1) J. Polchinski: hep-th/0603249.
2) J. S. Schwinger: J. Math. Phys. 2, 407 (1961).
3) L. V. Keldysh: Zh. Eksp. Teor. Fiz. 47, 1515 (1964)[Sov. Phys. JETP 20, 1018 (1965)].
4) S. Weinberg: Phys. Rev. D 72, 043514 (2005).
5) V. K. Onemli and R. P. Woodard: Class. Quant. Grav.
19, 4607 (2002).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Effective Higgs interactions of composite dark matter†
E. T. Neil∗1,∗2 for the LSD Collaboration
The recent discovery of the Higgs boson has placed
significant and direct constraints on models which predict new physics near the electroweak scale. At thesame time, recent dark matter direct-detection experiments have greatly improved their sensitivity, pushinginto the region of parameter space where dark matterinteracts with the standard model through exchange
of a Higgs boson.
These new constraints are particularly interesting in
the context of composite dark matter models (e.g.1) ).
In such a model, the lightest stable bound state of astrongly-coupled gauge sector provides a dark mattercandidate. Although the bound state itself must be net
electroweak neutral due to direct-detection experimental constraints, its constituents may carry electroweak
charges; the resulting interactions with the standard
model in the early universe can explain the observed
dark matter abundance, while scattering from presentday direct detection experiments is through suppressedhigher-dimensional operators2).
If the dark gauge interaction spontaneously breaks
a continuous symmetry, then some of the bound states
will be massless Nambu-Goldstone bosons, which
are ruled out by experiment if they are electroweak
charged. A realistic composite dark matter model
thus requires a mechanism for mass generation of
the constituents. In most models the constituentsare fermions, and they can be given mass throughthe Higgs mechanism; depending on the assignmentof charges, “vector-like” mass terms may also be allowed3) . The Higgs couplings required for mass generation are directly constrained by direct-detection experiment, in terms of the Higgs coupling of the dark
matter bound state itself.
We consider for concreteness a model consisting ofan SU(4) dark gauge force, and a set of degeneratefermions mf carrying electric charge Q = ±1/2. The
dark matter candidate is a neutral baryon-like boundstate of four such fermions, and has total mass mB .
The coupling of the Higgs boson to this baryon-likestate is given by the formula�mB � v ∂mf (h) �� f (B)gh,B =fv
mf∂h �h=v(1)fwhere v = 246 GeV is the vacuum expectation value(B)of the Higgs field. The factor ff contains the scalar
matrix element of the fermions inside the baryon-like†∗1∗2

Condensed from the article in Phys. Rev. D89, 094508(2014)RIKEN Nishina Center
Department of Physics, University of Colorado, Boulder- 156 -

0.2
0.1
Αmax

0.05

0.02
0.01

0

1000

2000

mB GeV

3000

4000

Fig. 1. From3) , upper bound on the effective Higgs coupling α based on three lattice simulations at various
values of the fermion mass (green curves) and in theheavy quark limit (red dotted curve). The filled region
on the left shows values of mB ruled out by experimental bounds on light charged particles from LEP.

state, �B|f¯f |B�. This matrix element can be extracted using the Feynman-Hellmann theorem fromthe slope of the baryon mass, ∂mB /∂mf ; this is a
non-perturbative quantity, and is calculated using lattice simulations of the SU(4) theory. We find 0.15 (B)
ff  0.34 in the range of fermion masses simulated.
Finally, the term in parentheses,�v ∂mf (h) ��
α=
,
(2)
mf
∂h �h=v

is entirely model-dependent, and parameterizes thefraction of the fermion mass mf which is generated dueto the Higgs mechanism; if there are no “vector-like”
mass terms, then α = 1. The current upper boundon α in this model, based on our lattice calculation of(B)
ff and the latest experimental results from LUX4) ,is shown in Fig. 1. For the entire range of models
considered, this constraint is significantly less than 1,
indicating that generation of mf in this model requires
more than the Higgs mechanism alone.
References
1) G. D. Kribs, T. S. Roy, J. Terning, and K. M. Zurek,
Phys. Rev. D81 (2010) 095001
2) T. Appelquist et al. (LSD Collaboration): Phys. Rev. D88(2013), 014502
3) T. Appelquist et al. (LSD Collaboration): Phys. Rev. D89(2014), 094508
4) D. S. Akerib et al. (LUX Collaboration): Phys. Rev. Lett. 112(2014) 9, 091303

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Effective field theory for spacetime symmetry breaking†Y. Hidaka,∗1 T. Noumi,∗1 and G. Shiu∗2,∗3
Symmetry and its spontaneous breaking play an important role in various areas of physics. In particular,
the low-energy effective field theory (EFT) based on
the underlying symmetry structures provides a powerful framework for understanding the low-energy dynamics in the symmetry broken phase.
For internal symmetry breaking in Lorentz invariant systems, the EFT based on coset construction had
been established in 1960’s1,2) . When a global symmetry group G is broken to a residual symmetry group
H, the corresponding Nambu-Goldstone (NG) fields
π(x) are introduced as the coordinates of the coset
space G/H and the general effective action can be constructed from the Maurer-Cartan one form,
Jµ = Ω−1 ∂µ ΩwithΩ(x) = eπ(x) ∈ G/H .

(1)

Such a coset construction was also extended to spacetime symmetry breaking3,4) accompanied by the inverse Higgs constraints5) and has been applied to various systems. Although the coset construction captures certain aspects of spacetime symmetry breaking,its understanding seems incomplete compared to theinternal symmetry case.
For example, a naive counting of broken spacetime
symmetries based on the global symmetry picture contains redundant fields and causes a wrong counting ofNG modes. For conformal symmetry breaking, it is
known that the inverse Higgs constraints compensate
such a mismatch of NG mode counting. It is also argued recently that the inverse Higgs constraints eliminate not only the redundant fields but also the massivemodes, which nonlinearly transform under the broken
symmetries (see, e.g.,6–8) ). In addition to the masslessmodes, such massive modes associated with the symmetry breaking can be relevant in the construction ofphenomenological models (e.g. massive fields with a
Hubble scale mass are nonnegligible in cosmology).
In this work, we discussed the effective field theory for spacetime symmetry breaking from the local
symmetry point of view. By gauging spacetime symmetries, the identification of NG fields and the construction of the effective action are performed based on
the breaking pattern of diffeomorphism, local Lorentz,
and (an)isotropic Weyl symmetries as well as the internal symmetries including possible central extensions
in nonrelativistic systems. Such a local picture distinguishes, e.g., whether the symmetry breaking condensations have spins and provides a correct identifica†

∗1
∗2
∗3

tion of the physical NG fields, while the standard coset
construction based on global symmetry breaking doesnot. We illustrated that the local picture becomes important in particular when we take into account massive modes associated with symmetry breaking, whose
masses are not necessarily high.
We also revisited the coset construction for spacetime symmetry breaking. Based on the relation between the Maurer-Cartan one form and connections forspacetime symmetries, we classify the physical meanings of the inverse Higgs constraints by the coordinate
dimension of broken symmetries. Inverse Higgs constraints for spacetime symmetries with a higher dimension remove the redundant NG fields, whereas those fordimensionless symmetries can be further classified by
the local symmetry breaking pattern.
We are now working on several applications of ourapproaches for spacetime symmetry breaking. For example, there are some recent discussions that inhomogeneous chiral condensations may appear in the QCD
phase diagram. Using our EFT framework, we discuss
the dispersion relation of the NG field in such a phase.
Another ongoing application is inflation. We are e.g.
trying to classify the source of primordial gravitational
waves (which potentially affect the B-mode polarization of cosmic microwave backgrounds) by the symmetry breaking point of view. We hope to report those
applications in near future.
References

Condensed from the article in arXiv:1412.5601.
RIKEN Nishina Center
Department of Physics, University of Wisconsin, Madison
Center for Fundamental Physics and Institute for Advanced
Study, Hong Kong University of Science and Technology- 157 -

1) S. R. Coleman, J. Wess and B. Zumino, Phys. Rev.
177, 2239 (1969).
2) C. G. Callan, Jr., S. R. Coleman, J. Wess and B. Zumino, Phys. Rev. 177, 2247 (1969).
3) D. V. Volkov, Sov. J. Part. Nucl. 4, 3 (1973) .
4) V. I. Ogievetsky, Proc. of X-th Winter School of Theoretical Physics in Karpacz 1, 117 (1974).
5) E. A. Ivanov and V. I. Ogievetsky, Teor. Mat. Fiz. 25,
164 (1975).
6) A. Nicolis, R. Penco, F. Piazza and R. A. Rosen, JHEP
1311, 055 (2013) [arXiv:1306.1240 [hep-th]].
7) S. Endlich, A. Nicolis and R. Penco, Phys. Rev. D 89,
no. 6, 065006 (2014) [arXiv:1311.6491 [hep-th]].
8) T. Brauner and H. Watanabe, Phys. Rev. D 89, no. 8,085004 (2014) [arXiv:1401.5596 [hep-ph]].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Dynamical breaking of shift-symmetry in supergravity-based
inflation†
A. Mazumdar,∗1 T. Noumi,∗2 and M. Yamaguchi∗3
The observations of the cosmic microwave background (CMB) temperature anisotropies1,2) now
strongly support the occurrence of primordial inflation in the early Universe. The observed temperature anisotropy can be well fitted by the primordial
perturbations generated during inflation and the anticorrelation of the temperature (T) and E-mode polarization at large angular scale suggests that the primordial perturbations have been stretched on superhorizon
scales1,2) . In addition, very recently, BICEP2 reported
the detection of the primordial tensor perturbations
through the B-mode polarization as3)
r = 0.20+0.07−0.05 (68%CL),(1)where r is the tensor-to-scalar ratio. To explain thislarge tensor-to-scalar ratio is challenging for cosmology and particle physics because of the Lyth bound4) :one would expect a super-Planckian excursion of theinflaton field in order to generate large r.
Generally speaking, the super-Planckian excursionof the inflaton is problematic from the effective field
theory (EFT) point of view. In particular, within
string theory there are many scales, the string scale,
Ms , the compactification scale, Mc and the derived
4 dimensional Planck scale, with a spectrum, Ms ≤Mc ≤ Mp . Beyond Ms there are quantum corrections
not only to the inflaton potential but also to the inflaton kinetic term which can lead to various complications. Even if we assume that we have only one fundamental scale, such as Mp , there are many issues pertaining to the validity of an EFT when the field’s VEVgoes beyond Mp . In principle, a gauge singlet inflaton
can couple to many degrees of freedom, including theStandard Model and the hidden sector degrees of freedom. Typically, the individual inflaton’s couplings tomatter has to be smaller than 10−3 to maintain theflatness of the inflaton potential and also to match thedensity perturbations created during inflation.
In spite of all these challenges, we wish to ask thequestion - whether can we explain at least a suchsmall inflaton couplings to matter, and large inflaton’s VEV during inflation within an EFT approachby invoking some symmetry such as shift-symmetry,φ → φ = φ + c, where φ is the inflaton and c is aconstant. Within EFT, one has to ensure that the inflaton’s and all other field’s kinetic terms are small,and here we simply assume so in some patch of the
†

∗1
∗2
∗3

Condensed from the article in Phys.Rev. D90 (2014) 043519.
Physics Department, Lancaster University
RIKEN Nishina Center
Department of Physics, Tokyo Institute of Technology- 158 -

Universe just to be within the EFT regime. Sucha shift-symmetry has been for the first time introduced in the context of chaotic inflation in supergravity (SUGRA)5,6) . However, based on the same token if
shift-symmetry remains unbroken inflation would neveroccur in our patch of the universe. The shift-symmetry
has to be broken, but in such a way that the breaking remains soft, which could be understood via somedynamics of the fields. A hard breaking can be introduced5,6) , but the predictions can be lost or one has toresort to some anthropic arguments.
The purpose of this work is to illustrate a concrete model of dynamical shift symmetry breaking.
We showed that it is indeed possible to break theshift-symmetry dynamically within 4 dimensional supergravity prior to a long phase of inflation. Thanks
to the shift-symmetry, the leading contribution to the
inflaton potential is free from the dangerous exponential factor even after its breaking, which is the main
obstacle to realizing the super-Planckian inflation insupergravity. In our simple mode, the resulting effective inflaton potential schematically takes the form
φinfwith µ being the dynamical symVeff (φinf ) ∼ cosµmetry breaking scale. This potential can induce an inflationary epoch with the inflaton excursion ∆φinf ∼ µ.
Unfortunately, in this model, it is difficult to realize the super-Planckian inflation ∆φinf > Mp as longas the dynamical symmetry breaking scale µ is subPlanckian. We hope to extend our simple model torealize the super-Planckian inflation, in near future.
References
1) G. Hinshaw et al. [WMAP Collaboration], arXiv:1212.5226[astro-ph.CO].
2) P. A. R. Ade et al. [Planck Collaboration],
arXiv:1303.5082 [astro-ph.CO].
3) P. A. R. Ade et al. [BICEP2 Collaboration],
arXiv:1403.3985 [astro-ph.CO].
4) D. H. Lyth, Phys. Rev. Lett. 78, 1861 (1997) [hepph/9606387].
5) M. Kawasaki, M. Yamaguchi and T. Yanagida, Phys.
Rev. Lett. 85, 3572 (2000) [arXiv:hep-ph/0004243].
6) M. Kawasaki, M. Yamaguchi and T. Yanagida, Phys.
Rev. D 63, 103514 (2001) [arXiv:hep-ph/0011104].

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Non-Gaussianities of primordial perturbations and tensor soundspeed†
T. Noumi∗1 and M. Yamaguchi∗2
Inflation is now widely accepted as a paradigm ofearly Universe to explain the origin of the primordial
perturbations as well as to solve the horizon and theflatness problems of the standard big-bang cosmology.
The current observational data such as the cosmic microwave background (CMB) anisotropies support almost scale-invariant, adiabatic, and Gaussian primordial curvature fluctuations as predicted by inflation.
While the paradigm itself is well established and widely
accepted, its detailed dynamics, e.g. the identificationof an inflaton, its kinetic and potential structure, andits gravitational coupling, are still unknown.
The non-Gaussianities of primordial curvature perturbations are powerful tools to give such informations.
For example, it is well-known that the equilateral typeof bispectrum of primordial curvature perturbations isenhanced by the inverse of their sound speed squared
1,2). The null observation of the equilateral type byequil= 42 ± 75
the Planck satellite, characterized as fNL
3)(68% CL) , yields stringent constraints on the soundspeed of the curvature perturbations as cs ≥ 0.02 (95%CL)3) .
Inflation generates not only primordial curvature
perturbations but also primordial tensor perturbations
4). Very recently, it was reported that primordial tensor perturbations have been found and the tensor-to5)
scalar ratio r is given by r = 0.20+0.07−0.05 (68% CL) ,though it is constrained as r < 0.11(95% CL) in
the Planck results6) . Their amplitude directly determines the energy scale of inflation, so it is estimated as V 1/4  2.2 × 1016 GeV given r  0.25) andPζ  2.2 × 10−96) . If we go beyond the powerspectrum, it is known that the bispectra of primordial tensor perturbations enable us to probe the gravitational
coupling of the inflaton field7) . Such a non-trivial gravitational coupling easily modifies the sound speed ofprimordial tensor perturbations, cγ , and it can significantly deviate from unity8) . Then, one may wonder if
the small sound velocity of primordial tensor perturbations can enhance their non-Gaussianities as in thecase of the curvature perturbations. In this work, we
addressed this issue.
The relation between the sound speed and thenon-Gaussianities of primordial curvature perturbations can be clearly understood by use of the effective field theory (EFT) approach to inflation9) . Inflation can be characterized by the breakdown of timediffeomorphism invariance due to the time-dependent
†

∗1
∗2

cosmological background and the general action for
inflation can be constructed based on this symmetry
breaking structure. The primordial curvature perturbation can be identified with the Goldstone mode π associated with the breaking of time-diffeomorphism invariance. The symmetry arguments require that modification of the sound speed cs induces non-negligible
cubic interactions of the Goldstone mode π, and hence
the sound speed and the bispectrum of the curvature
perturbations are directly related.
In this work, we investigated the relation between
the sound speed of tensor perturbations and the bispectrum of primordial perturbations, based on the
EFT approach. We first identified what kind of operators can modify the tensor sound speed. Then, weclarify which type of non-Gaussianity arises associatedwith the modification and can be used as a probe forthe tensor sound speed. We found that the tensor
sound speed is not directly related to tensor bispectra,in contrast to the scalar sound speed case. We also
discussed primordial trispectra as a possible probe oftensor sound speed.
References

Condensed from the article in arXiv:1403.6065.
RIKEN Nishina Center
Department of Physics, Tokyo Institute of Technology- 159 -

1) D. Seery and J. E. Lidsey, JCAP 0506, 003 (2005)[astro-ph/0503692].
2) X. Chen, M. -x. Huang, S. Kachru and G. Shiu, JCAP
0701, 002 (2007) [hep-th/0605045].
3) P. A. R. Ade et al. [Planck Collaboration],
arXiv:1303.5084 [astro-ph.CO].
4) A. A. Starobinsky, JETP Lett. 30, 682 (1979) [Pisma
Zh. Eksp. Teor. Fiz. 30, 719 (1979)].
5) P. A. R. Ade et al. [BICEP2 Collaboration],
arXiv:1403.3985 [astro-ph.CO].
6) P. A. R. Ade et al. [Planck Collaboration],
arXiv:1303.5082 [astro-ph.CO].
7) X. Gao, T. Kobayashi, M. Yamaguchi and J. ’i. Yokoyama,
Phys. Rev. Lett. 107, 211301 (2011) [arXiv:1108.3513[astro-ph.CO]].
8) T. Kobayashi, M. Yamaguchi and J. ’i. Yokoyama,
Prog. Theor. Phys. 126, 511 (2011) [arXiv:1105.5723[hep-th]].
9) C. Cheung, P. Creminelli, A. L. Fitzpatrick, J. Kaplan and L. Senatore, JHEP 0803, 014 (2008)[arXiv:0709.0293 [hep-th]].

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Spin operator and entanglement in quantum field theory†
K. Fujikawa,∗1 C.H. Oh,∗2 and C. Zhang∗2
Entanglement is studied in the framework of Dyson’s
S-matrix theory in relativistic quantum ﬁeld theory,
which leads to a natural deﬁnition of entangled statesof a particle-antiparticle pair and the spin operator
from a Noether current. As an explicit example,
the decay of a massive pseudo-scalar particle into anelectron-positron pair is analyzed. Two spin operators are extracted from the Noether current. The
Wigner spin operator characterizes spin states at therest frame of each fermion and, although not measurable in the laboratory, gives rise to a straightforward
generalization of the low energy analysis of entanglement to the ultra-relativistic domain. In contrast, if
one adopts a (modiﬁed) Dirac spin operator, the entanglement measured using spin correlation becomesmaximal near the threshold of the decay, while the entanglement is replaced by the classical correlation for
the ultra-relativistic electron-positron pair by analogy
to the case of neutrinos, for which a hidden-variablestype description is possible. Entanglement in this sense
depends on the energy scale involved. Chiral symmetry which is fundamental in particle physics diﬀerentiates the spin angular momentum and the magnetic moment. The use of weak interaction, which can measure
helicity, is suggested in the analysis of entanglement
at high energies instead of a Stern-Gerlach apparatus,
which is known to be useless for the electron. A difference between the electron spin at high energies andthe photon linear polarization is also noted.
We formulate the entanglement in the frameworkof relativistic quantum ﬁeld theory, or more precisely,in the S-matrix theory deﬁned by Dyson.1) In the Smatrix theory, we treat only asymptotic states that
contain particles far apart from each other.
We consider the decay of a very massive pseudoscalar particle P into an electron-positron ∫pair byan interaction Hamiltonian, HI (t) = g d3 x :P (x)ψ̄(x)iγ5 ψ(x) : with a coupling constant g. The
Dyson∫ formula for the S-matrix gives the state Ψ =−ig d4 x : P (x)ψ̄(x)iγ5 ψ(x) : |P (⃗0)⟩, where we assume a small g. We then obtain for the ﬁxed momentum direction of the electron,1Ψ(⃗p) ≡ √ [a† (⃗p, s)b† (−⃗p, −s) + a† (⃗p, −s)b† (−⃗p, s)]|0⟩.
2This shows a way to prepare a desired state in theframework of local and causal relativistic ﬁeld theory. All the properties of the asymptotic state are ac†∗1∗2

Condensed from the article in Phys. Rev. D. 90, 025028(2014).
RIKEN Nishina Center
Center for Quantum technologies, National University ofSingapore,- 160 -

counted for in the framework which is consistent withlocality, causality and the uncertainty principle; in particular, it is important to recognize that we integrate
over the entire Minkowski space in deﬁning Ψ; thatis, we have no information about when and where theparticle decayed.
Spin Operator
The conserved angular momentum operator (Noether∫ˆcharge) of the Dirac action is given by J⃗ = d3 x :⃗ + S]ψ(x)⃗ψ † (x)[L:, which is written as∫∑1{ξ(s′ )†⃗σ ξ(s)a† (⃗d3 pp, s′ )a(⃗
p, s)
2
′
s,s

+

∫

−ξ † (−s)⃗σ ξ(−s′ )b† (⃗p, s′ )b(⃗p, s)}()∑⃗ p, s)d3 p{a† (⃗p, s) La(⃗s()
⃗ p, s) }.
+b† (⃗p, s) Lb(⃗

The ﬁrst term is called the Wigner spin operator,
which is not directly measured in the laboratory. We
instead deﬁne the (modiﬁed) Dirac spin operator
ˆ⃗
S(⃗
p)
∑ 1m
1
≡
ξ † (s′ )⃗σT ξ(s) + p̂ξ † (s′ )(⃗σ · p̂)ξ(s)]
{[
2
E
2
′
s,s

×a† (⃗
p, s′ )a(⃗
p, s)
1m †
1
ξ (−s)⃗σT ξ(−s′ ) + p̂ξ † (−s)(⃗σ · p̂)ξ(−s′ )]−[2E2×b† (−⃗
p, s′ )b(−⃗p, s)},

which is close to what is measured in the laboratory.
A salient feature of this spin is that it appraoches thehelicity state proportional to the momentum directionp̂ for E → ∞. That is, the spin correlation at highenergies becomes similar to the correlation of neutrinos. The spin correlation of two neutrinos, which canhave only two states h = ±, does not deﬁne the entanglement in the conventional sense. That is, thehigh energy electron states behave like classical particles, which show the correlation but not entanglement.
This transition to helicity states may be measured using weak interactions.2)
References
1) F. J. Dyson: Phys. Rev. 75, 1736 (1949).
2) K. Fujikawa and R. Shrock: Phys. Rev. Lett. 45, 963(1980).

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Linearity of quantum probability measure and Hardy’s model†
K. Fujikawa,∗1 C.H. Oh,∗2 and C. Zhang∗2
Hardy proposed a characterization of entanglementthat does not use inequalities by EPR-type arguments.
It is however disturbing that his scheme, which is intended as a measure of entanglement, completely fails
for the maximally entangled case.1)
The local hidden-variables model in d = 4 = 2 × 2
dimensions of the Hilbert space is defined by2)∫
⟨ψ|a · σ ⊗ b · σ|ψ⟩ =ρ(λ)dλa(ψ, λ)b(ψ, λ), (1)Λwhere a and b are 3-dimensional unit vectors, σ stands
for the Pauli matrix, and a(ψ, λ) and b(ψ, λ) are dichotomic variables assuming the eigenvalues ±1 of a·σ
and b · σ, respectively. One can show that this local hidden-variables model does not satisfy the linearity of the quantum mechanical probability measure in
the sense ⟨ψ|a · σ ⊗ b · σ|ψ⟩ + ⟨ψ|a · σ ⊗ b′ · σ|ψ⟩ =⟨ψ|a · σ ⊗ (b + b′ ) · σ|ψ⟩ for non-collinear b and b′ .
If the linearity of the probability measure is strictly
imposed, which is tantamount to asking that the noncontextual hidden-variables model in d = 4 gives the
CHSH inequality |⟨B⟩| ≤ 2 uniquely,3) it is shown thatthe hidden-variables model can describe only separable
quantum mechanical states4)∫⟨ψ|a · σ ⊗ b · σ|ψ⟩ =ρ1 (λ1 )dλ1 a(ψ, λ1 )∫(2)
× ρ2 (λ2 )dλ2 b(ψ, λ2 ).
In this case, it is shown that Hardy’s model becomestrivial. Although Hardy’s paradox is interesting as anexperimental test of local realism, its mathematical basis is less solid than hitherto assumed.
Hardy’s model
Hardy defines the projection operators1)Ûi = |ui ⟩⟨ui |, D̂i = |di ⟩⟨di |,(3)

with i = 1, 2, and1[β 1/2 |+⟩i + α1/2 |−⟩i ],α+β1[β 3/2 |+⟩i − α3/2 |−⟩i ]|di ⟩ = √α3 + β 3|ui ⟩ = √(4)

for the entangled state |ψ⟩ = α|+⟩1 |+⟩2 − β|−⟩1 |−⟩2
with α2 + β 2 = 1.
†
∗1∗2

Condensed from the article in Int. J. Mod. Phys. A29,
1450017 (2014).
RIKEN Nishina Center
Center for Quantum Technologies, National University ofSingapore- 161 -He then shows the relations⟨ψ|D1 U2 D1 |ψ⟩= 1,⟨ψ|D1 |ψ⟩⟨ψ|D2 U1 D2 |ψ⟩= 1,⟨ψ|D2 |ψ⟩⟨ψ|D1 D2 D1 |ψ⟩
αβ
= 1−
,
⟨ψ|D1 |ψ⟩(1 − αβ)⟨ψ|U1 U2 |ψ⟩ = 0,

(5)
(6)
(7)
(8)

with 0 < αβ ≤ 1/2.
In the hidden-variables model, the projection operators are assigned their eigenvalues; for example,
D1 (ψ, λ) = 1 or 0, dependingon the hidden-variable∫
λ. Relation (7) implies dλρ(λ)D1 (ψ, λ)D2 (ψ, λ) ̸= 0
for 0 < αβ < 1/2 and thus

D1 (ψ, λ) = 1 and D2 (ψ, λ) = 1(9)∫for some λ, while (8) implies dλρ(λ)U1 (ψ, λ)U2 (ψ, λ) =0 and thus
U1 (ψ, λ)U2 (ψ, λ) = 0(10)

for all λ. On the other hand relations (5) and (6) imply
D1 (ψ, λ) = 1 ⇒ U2 (ψ, λ) = 1,D2 (ψ, λ) = 1 ⇒ U1 (ψ, λ) = 1,(11)

⟨U1 ⟩ = ⟨U2 ⟩ = ⟨D1 ⟩ = ⟨D2 ⟩ = 0,(12)respectively, where ⇒ means ”inevitably implies”.
For the entangled state with 0 < αβ < 1/2 except
for αβ = 1/2, which implies the maximum entanglement, the relations (9)-(11) are inconsistent.1) This iscalled Hardy’s paradox, which shows the inconsistencyof local realism with entanglement except for the maximally entangled case without referring to inequality.
On the other hand, for a pure state, Bell’s theorem|⟨B⟩| ≤ 2 with B = a·σ⊗(b+b′ )·σ+a′ ·σ⊗(b−b′ )·σ forany a, a′ , b, and b′ implies5) relation (2), namely, theseparable state. The separable state in Hardy’s model,
which is consistent with local realism, imlies α = 1 and
β = 0, for example, for which |ψ⟩ = |+⟩1 |+⟩2 whileÛi = |−⟩ii ⟨−| and D̂i = |−⟩ii ⟨−|. In this case,and all the correlations vanish; thus, Hardy’s model
becomes mathematically trivial. Hardy’s model is inconsistent with local realism by construction.
References
1) L. Hardy: Phys. Rev. Lett. 71, 1665 (1993).
2) J. S. Bell: Physics 1, 195 (1965).
3) J. F. Clauser, M. A. Horne, A. Shimony, R. A. Holt:
Phys. Rev. Lett. 23, 888 (1969).
4) K. Fujikawa: Prog. Theor. Phys. 127, 975 (2012).
5) N. Gisin: Phys. Lett. A154, 201 (1991).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

SSD and the infinite circumference limit of CFT†
T. Tada∗1
Among all the Virasoro generators of Conformal
Field Theory (CFT), three of them, L0 , L1 and L−1 ,form a subalgebra that is isomorphic to sl(2, R) andcorresponds to the global conformal transformation.
The Casimir operator of the subalgebra can be expressed as
C2 = L20 − L2+ − L2− ,(1)

L1 + L−1
L1 − L−1, L− =.
22i(2)

In analogy with the 2+1 dimensional Lorentz transformation, the space spanned by L0 , L+ and L− isapparently divided into three distinctive regions. The
first region is the “time-like” region that contains L0and small perturbations around it. Any vector within
this region can be transformed to L0 upto some numerical multiplication, by the global conformal transformatiom or the sl(2, R). This is actually the region
one would have in mind, when one demanded the invariance of the vacuum on the basis of the physicalequivalence for the states connected by the global conformal transformation. The second is the “space-like”
region, which contains the linear combination of L+
and L− . The region between these two is the last one,and could be called the “light-cone” region. This region is represented by either L0 − L+ or L0 − L− .
If one further invokes the analogy with the Lorentz
geometry, the “time-like” region corresponds to the“massive” representation. Since one observes the spectrum of L0 in this region, the “mass” in this case shouldbe the inverse of the circumference, or the finite scale of
CFT1,2) . Then, it is natural to induce that the “lightcone” region corresponds to the “massless” representation and the infinite circumference. In this letter, we
will argue that if one takes the generator in the “lightcone” region, say L0 − L+ (plus anti-holomorphic partL̄0 − L̄+ , to be exact), as a Hamiltonian, one can obtaina CFT with the infinite circumference.
Should we adopt a generator that corresponds to
L0 − L+ as a Hamiltonian, we can define the following
conserved charges:
 t=const.
2κ
1
1
Lκ ≡
dz(− (z − 1)2 )e z−1 T (z), (3)2πi2where T (z) = Tzz (z) is the energy momentum tensor
of the original CFT. Note that for κ = 0
 t=const.
11dz(− (z − 1)2 )T (z)
L0 =
2πi
2
∗1

L1 + L−1.
2(4)

One can further calculate the commutation relations
among the charges defined above using the operator
product expansion of the energy momentum tensor
T (z)T (w) ∼c/2
2T (w)∂w T (w)+· · · .(5)++42(z − w) (z − w)
z−w

The result reads

where
L+ =

= L0 −RIKEN Nishina Center- 162 -

[Lκ , Lκ ] = (κ − κ )Lκ+κ +c 3
κ δ(κ + κ ).
12(6)

We have thus obtained the continuous Virasoro algebrawith the central charge c, establishing that we have thetheory that exhibits the continuous spectrum. This isconsistent with the argument presented at the beginning.
This also nicely explains the feature observed in thephenomena called sine-square deformation (SSD) atleast for the case that involves CFT. It was found
3–6)
that a certain class of quantum systems, systems
with closed and open boundary conditions, have identical vacua provided that the coupling constants of the
open-boundary system are modulated in a specific way.
In particular, SSD works for two-dimensional conformal field theories and it’s implications for string theory were discussed by the present author7,8) . SSD for
CFT adopts exactly (4) as the (holomorphic part of) Hamiltonian. At that time, it had been somewhat
enigmatic that these two systems with different boundary conditions share the same vacuum state, but thiscan be explained through the discovery of the continuous spectrum for the SSD system. Because the continuous spectrum suggest that SSD system has an infinitely large space, the distinction between the open
and closed condition at the ends that located at infinitely away, is no longer physically relevant.
References
1) A. A. Belavin, A. M. Polyakov and A. B. Zamolodchikov: Nucl. Phys. B 241, 333 (1984).
2) J. L. Cardy: J. Phys. A 17, L385 (1984).
3) A. Gendiar, R. Krcmar and T. Nishino: Prog. Theor.
Phys. 122 (2009) 953; ibid. 123 (2010) 393.
4) H. Katsura: J. Phys. A 45, 115003 (2012)5) H. Katsura: J. Phys. A: Math. Theor. 44 (2011) 252001.
6) I. Maruyama, H. Katsura and T. Hikihara, Phys. Rev.
B 84 (2011) 165132.
7) T. Tada: Proceedings of the 12th Asia Pacific Physics
Conference JPS Conf. Proc. 1, 013003 (2014) .
8) T. Tada: Mod. Phys. Lett. A 30, 1550092 (2015).

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Towards U(N |M ) knot invariant from ABJM theory
B. Eynard∗1,∗2 and T. Kimura∗1,∗3
The knot invariant can be realized using the Wilson
loop operator in Chern–Simons gauge theory. Especially for the invariant for unknot and torus knot, there
exists an integral representation analogous to the U(N )symmetric matrix model. Recently it was pointed outthat the partition function of ABJM theory on S 3 canbe written as a supermatrix integral.1) From this pointof view, it is natural to explore a possibile connection
between the ABJM Wilson loop and a knot invariant.
The ABJM partition function is written as follows,

2

1
1
N
N
Z=
[dx] [dy]
det
,
x −y
1≤i,j≤N
N !2
2 cosh i 2 j(1)22
dx − 2g1s x
dx 2g1s yand [dy] = 2π ewith thewhere [dx] = 2π estring coupling constant gs = 2πi/k. In this expression the Wilson loop operator in the representation
R is given by the corresponding character of U(N |N )group, WR → StrR U (x; y) with the holonomy matrix
U (x; y) = diag(ex1 , · · · , exN , −ey1 , · · · , −eyN ). Whenthe partition λ, corresponding to the representation
R, satisfies ΛN +1 > N , this character is decomposed
into that for SU(N ) which is written in terms of the
Schur function,
StrR U (x; y) = sµ (ex ) sν (ey )

N


i,j=1

(exi − eyj ) ,(2)

where µti = λti+N and νit = λi+N . We consider thiscase in particular. Thus the integral representation for
the unknot Wilson loop in ABJM theory is now written
WR (Kunknot )

 N


1
N
N
= [dx] [dy] det
exi ξi +yi ηixi −yj2 cosh 2i=1(3)
with ξi = λi −i+1/2, ηi = λti −i+1/2. We can compute
this integral by applying the Fourier transform formula
2iwz/π/ cosh z,
1/ cosh w = dz
π e


1
WR (Kunknot ) = k −N q 2 (C2 (µ)−C2 (ν))


1
, (4)
× det
1
1
1≤i,j≤Nq 2 (ξi +ηj ) + q − 2 (ξi +ηj )where the parameteris defined as q = egs and



∞ 
1 2
1 2
C2 (λ) = i=1 λi − i + 2 − −i + 2
is the second Casimir operator, corresponding to the framing
∗1
∗2
∗3

Institut de Physique Théorique, CEA Saclay
CRM, Université de Montréal
RIKEN Nishina Centerfactor. This shows that the U(N |N ) character average
is factorized into that for U(1|1) theory. This kind of
property is called Giambelli compatibility.2)
In order to see the connection to the ordinary knot
invariant in U(N) from the determinantal expression(4), it is convenient to rewrite as follows,1k −N q 2 (C2 (µ)−C2 (ν))

N 
−1

1
1
q 2 (ξi +ηj ) + q − 2 (ξi +ηj )

i,j=1

×

N 


i<j

1

1

q 2 (ξi −ξj ) − q − 2 (ξi −ξj )

 1

1
q 2 (ηi −ηj ) − q − 2 (ηi −ηj ) .
(5)

The last two factors coincide with the Wilson loop average in U(N ) theory, which is given by the quantum
dimension of the representation R, up to the normalization constant.
The integral formula shown above can be generalized
to the situation for the torus knot, which is labeled by
two coprime integers (P, Q). In this case the partition
function is slightly modified
1[dx]N [dy]N
Z(P,Q) =
N !2




1
1
det
.
× det
x −y
x −y
1≤i,j≤N
2 cosh i2P j 1≤i,j≤N 2 cosh i2Q j(6)
We can show this torus knot partition function
is just given by the symplectic transform of theoriginal unknot partition function.
Thus it canbe shown that they are related in a simple way,
Z(P,Q) = (P Q)N Z(1,1) . Since there exists the U(N |N )character, written
in terms of the Schur function,sλ (uQ ; v Q ) = µ cµλ,Q sµ (u; v), as well as the ordinary
U(N ) theory, finally the torus knot Wilson loop average can be expressed as a linear combination of thatfor the fractionally framed unknot,

 


WR (KP,Q ) =cVR,Q WR (K1,f )(7)Vwith the framing number f = Q/P . This is just a
supersymmetric version of the Rosso–Jones formula forthe torus knot invariant.3)
References
1) A. Kapustin et al, JHEP 1003 (2010) 089.
2) A. Borodin et al, Adv. Appl. Math. 37 (2006) 209.
3) M. Rosso, V. Jones, J. Knot Th. Ram. 2 (1993) 97.

- 163 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-6. Particle Physics

Duality and integrability of supermatrix model with external source†
T. Kimura∗1,∗2
In quantum field theory, in order to compute correlation functions, it is convenient to introduce the generating function by adding an extra source term. Such agenerating function is defined in the sense of path integral, and thus it is quite difficult to compute in general.
However, in the matrix model, just a zero dimensional
theory, a number of methods for computation are established, which are also applicable to the model withthe external source. In this report we generalize theduality of the matrix model with the external sourcewith a characteristic polynomial, which was originallyfound in the Gaussian matrix model,1) to the supermatrix model with an arbitrary matrix potential.
The correlation function of the characteristic polynomial in the supermatrix model, which we study here,is given by


p
q
M
ΨN,M ;p,q {ai }N
,
{b
}
;
{λ
}
,
{µ
}
j
α
β
i=1
j=1
α=1
β=1
p

Sdet(λα − Z)
1
= dZ e− h̄ Str W (Z)+Str ZC α=1(1)
qSdet(µ
β − Z)
β=1

where Z is a size N + M Hermitian supermatrix, andthe external source is C = diag(a1 , . . . , aN , b1 , . . . , bM ).
This formula includes several useful situations, e.g., theordinary characteristic polynomial average (M = q =0), the average of inverses (M = p = 0), and the ratio average (M = 0). Therefore it provides a master
formula for the characteristic polynomial average invarious matrix models.
The matrix measure in the integral is invariant under
the supergroup transformation, dZ = d(U ZU −1 ) withU ∈ U(N |M ), which is expressed in terms of eigenvalues, dZ = ∆N,M (x; y)2 dN x dM y dU . Here the Jacobian is given by the Cauchy determinant,∆N,M (x; y) =NMi<j (xi − xj )i<j (yi − yj ).
N,Mi,j (xi − yj )(2)Then, to compute the intgral, we now introduce theHarish-Chandra–Itzykson–Zuber formula for the supergroup U(N |M )2–4)


dU e
U(N |M )Str ZU CU −1

det exi ai det e−yi bj. (3)=∆N,M (x; y)∆N,M (a; b)

Applying this formula, we obtain the following expression for the matrix integral in terms of eigenvalues
†

∗1
∗2

Condensed from the article in PTEP 2014 123A01 (2014)
RIKEN Nishina Center
Institut de Physique Théorique, CEA Saclay- 164 -

ΨN,M ;p,q =

 N,M


1

1

dxi dyj e− h̄ W (xi )+ h̄ W (yj )+xi ai −yj bj

i,j×∆N +p,M +q (x, λ; y, µ). (4)∆N,M (a; b)∆p,q (λ; µ)Since the Cauchy determinant can be written as a determinant


xk−1
i
(5)
∆N,M (x; y) = det(xi − yj )−1
with i = 1, . . . , N , j = 1, . . . , M , k = 1, . . . , N − M , if
N ≥ M , we obtain the determinanal formula for thecharacteristic polynomial average


p
q
M
ΨN,M ;p,q {ai }N
i=1 , {bj }j=1 ; {λα }α=1 , {µβ }β=1
Qk−1 (ai ) Pk−1 (λα )1=det  R(ai ; bj ) SR (λα ; bj )  ,∆N,M (a; b)∆p,q (λ; µ)R̃λα ;µβSL (ai ; µβ )(6)where we have introduced auxiliary functions:1
Pi−1 (x) = xi−1 , R̃(x; y) =
,
x−y

1
Qi−1 (a) = dx Pi−1 (x) e− h̄ W (x)+xa ,R(a; b) =



(7)
(8)

1

dxdy R̃(x; y) e− h̄ (W (x)−W (y))+xa−yb , (9)11e− h̄ W (x)+xa ,
x−µ

1
1
SL (λ; b) = dye h̄ W (y)−yb .
λ−ySL (a; µ) =

dx

(10)
(11)

The formula (6) actually shows a duality between
the external source and the characteristic polynomial,
which is just given by Laplace (Fourier) transforms,


p
q
M
ΨN,M ;p,q {ai }N
i=1 , {bj }j=1 ; {λα }α=1 , {µβ }β=1


F.T.
M
= Ψp,q;N,M {λα }pα=1 , {µβ }qβ=1 ; {ai }N,{b}j j=1 .
i=1
(12)This is because the auxiliary functions transformto each other through the Fourier transformation:
Pi−1 (x) ↔ Qi−1 (a), R(x; y) ↔ R̃(a; b), SL (λ; b) ↔
SR (a; µ).
References
1) E. Brézin, S. Hikami, Comm. Math. Phys. 214 (2000) 11.
2) T. Guhr, J. Math. Phys. 32 (1991) 32.
3) J. Alfaro et al., J. Math. Phys. 36 (1995) 3085.
4) T. Guhr, Comm. Math. Phys. 176 (1996) 555.

Ⅱ-6. Particle Physics

RIKEN Accel. Prog. Rep. 48 (2015)

Bulk angular momentum and Hall viscosity in chiralsuperconductors†
A. Shitade∗1 and T. Kimura∗2,∗3
Chiral superfluids and superconductors (SCs) are exotic states whose time-reversal symmetry is spontaneously broken and Cooper pairs carry nonzero angular momentum (AM). There is a long-standing problem on the AM in chiral -wave SCs, the so-called
intrinsic AM paradox, which is summarized as Lz =h̄mN0 /2 × (∆0 /EF )γ , where |m| ≤ , N0 , ∆0 , EF , γ
are the magnetic quantum number, the total numberof electrons, the gap strength, the Fermi energy, andthe exponent characterizing the dependence on the SC
gap. γ = 0 is the most natural if all electrons fromCooper pairs with the AM z = h̄m. On the other
hand, γ = 1 is intuitively plausible if a electrons near
the Fermi surface from Cooper pairs.1) One of the obstacle is that the physical quantities involving the position operator are ill defined in periodic systems, andwe have to manage an inevitable divergence in the bulk
limit. An interesting clue to the AM is the Hall viscosity (HV), which has been intensively discussed in
the context of the quantum Hall effect. The important
relation ηH = h̄N0 s̄/2 holds in general gapped systems
at zero temperature,2) in which the orbital spin s̄ isequal to 2 in chiral -wave SCs. In this report, wederive the Berry-phase formulas for the AM and theHall viscosity (HV) to apply to chiral SCs in two andthree dimensions, which allow us to deal with the bulk
systems.
We examine an angular velocity from the gaugetheoretical viewpoint. Now that the system is rotated,
we have to deal with a theory in a curved spacetime.
We use the Cartan formalism, consisting of two gauge
potentials, a vielbein and a spin connection. Since weare now interested in the orbital AM, we do not consider the spin connection corresponding to the internal
AM for simplicity. A vielbein haµ is a gauge potential
corresponding to local spacetime translations, while aspin connection is that corresponding to local Lorentz
transformations. The spatial component of a vielbein
is related to a displacement vector. Since a vielbein
is a gauge potential, it induces a field strength called
torsion,T lj0 = ∂j hl 0 − ∂0 hl j ,T lij = ∂i hl j − ∂j hl i .

(1)

The former is “electric.” The first term describes anangular velocity if l and j are antisymmetric, while
the second term describes a strain-rate tensor if symmetric. On the other hand, the latter is “magnetic”
†

∗1
∗2
∗3

Condensed from the article in Phys. Rev. B90 134510 (2014)
Department of Physics, Kyoto University
Institut de Physique Théorique, CEA Saclay
RIKEN Nishina Center- 165 -

characterizing edge and screw dislocations in crystals.
Based on this formalism, we derive the momentum
polarization, at zero temperature in a gapped fermion
system,
occ 

dd π
Pk i =
π Ai π ,(2)
d k n
(2πh̄)nwhere π is the momentum, the summation is takenover the occupied states, the Berry connection is given
by Ainπ = ih̄ unπ |∂πi unπ , and unπ is the Bloch eigenstate. Then the AM is obtained by the antisymmetricpart of the momentum polarization,
occ 

dd π
Lk = ijk P ji =
 Ai π π j .
(3)
d ijk n(2πh̄)
nSince the Berry connection is regarded as the expectation value of the position operator in the Wannier basis, this Berry-phase formula really indicates  = x × p
in the momentum space.
i jHere we define the nonsymmetric viscosity by ηk l =il∂Tk /∂ −Tj0 . As well as the AM formula, we obtainηki lj =

occ 
dd π
1 ijm πk πl Ωnπm fnπ ,h̄(2πh̄)dn(4)where fnπ = f (nπ − µ) is the Fermi distribution function andis defined by Ωnπk = the Berry curvatureih̄2 ijk ∂πi unπ |∂πj unπ . The proper HV is obtained
as its symmetric part. Especially in two dimensions,the antisymmetric part yields
d2 π 21 
π Ωnπz fnπ .
(5)
ηH =
4h̄ n
(2πh̄)2
These expressions are quite analogous to that for theHall conductivity, corresponding to the charge transport. The integrand just differs in the factor of π.
By applying these formulas to the Bogoliubov–deGennes system, we obtain the AM for gapped chiralSCs at zero temperature(Ak × k)z = h̄mN0 /2 ,(6)
Lz = −h̄kwhich is consistent with γ = 0, and shows the relation
to the HV, Lz = 2ηH . See, for example, for the recent
microscopic studies suggesting γ = 0.3)
References
1) A. J. Leggett, Rev. Mod. Phys. 47 (1975) 331.
2) N. Read, Phys. Rev. B79 (2009) 045308.
3) Y. Tsutsumi, K. Machida, Phys. Rev. B85 (2012) 100506.

7. Astrophysics and Astro-Glaciology

Ⅱ-7. Astrophysics and Astro-Glaciology

RIKEN Accel. Prog. Rep. 48 (2015)

Insights from Antarctica on volcanic forcing during the Common Era†
M. Sigl,＊1 J. R. McConnell,＊1,＊2 M. Toohey,＊3 M. Curran,＊4 S. B. Das,＊5 R. Edwards,＊6 E. Isaksson,＊7 K. Kawamura,＊2,＊8
S. Kipfstuhl,＊9 K. Krüger,＊3,＊10 L. Layman,＊1 O. J. Maselli,＊1 Y. Motizuki,＊11 H. Motoyama,＊2 D. R. Pasteris,＊1 and
M. Severi＊12
Assessments of climate sensitivity to projected
greenhouse gas concentrations underpin environmental
policy decisions, with such assessments often based onmodel simulations of climate during recent centuries andmillennia1)-3). These simulations depend critically on
accurate records of past aerosol forcing from global-scalevolcanic eruptions, reconstructed from measurements ofsulphate deposition in ice cores4)-6). Non-uniform transportand deposition of volcanic fallout mean that multiple
records from a wide array of ice cores must be combined tocreate accurate reconstructions. Here we re-evaluated therecord of volcanic sulphate deposition using a much more
extensive array of Antarctic ice cores. In our newreconstruction, many additional records have been addedand dating of previously published records corrected
through precise synchronization to the annually dated West
Antarctic Ice Sheet Divide ice core7), improving andextending the record throughout the Common Era. Whereas
agreement with existing reconstructions is excellent after
1500, we found a substantially different history of volcanic
aerosol deposition before 1500; for example, global aerosol
forcing values from some of the largest eruptions (forexample, 1257 and 1458) previously were overestimated by
20–30% and others underestimated by 20–50%.
References

1) G. A. Schmidt et al.: J. Quat. Sci. 25, 7 9 (2010)..
2) G. C. Hegerl, et al.: Nature 440, 1029 (2006).
3) IPCC Summary for Policymakers in Climate Change 2007: The
Physical Science Basis (eds Solomon, S. et al.) (Cambridge
Univ. Press, 2007).
4) G. A. Schmidt, et al.: Geoscientific Model Dev. 5, 185 (2012).
5) T. J. Crowley, & M. B. Unterman: Earth Syst. Sci. Data 5, 187(2013).
6) C. C.Gao et al.: J. Geophys. Res. 113, D23111 (2008).
7) M. Sigl, et al.: J. Geophys. Res. 118, 1151 (2013).
† Condensed from the article in Nature Climate Change 4, 693–697(2014)＊1
Desert Research Institute＊2
National Institute of Polar Research＊3
GEOMAR Helmholtz Centre for Ocean Research Kiel
＊4
Australian Antarctic Division and Antarctic Climate and Ecosystems＊5

Woods Hole Oceanographic Institution
Department of Imaging and Applied Physics, Curtin University＊7
Norwegian Polar Institute＊8
Department of Biogeochemistry, JAMSTEC＊9
Alfred Wegener Institute, Helmholtz Centre for Polar andMarine Research＊10
University of Oslo＊11
RIKEN Nishina Center＊12
Department of Chemistry ‘Ugo Schi’, University of Florence＊6- 167 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-7. Astrophysics and Astro-Glaciology

Variation in chemical composition induced by solar energetic
particle events in the middle atmosphere
Y. Nakai,*1 Y. Motizuki,*1 M. Maruyama,*1 H. Akiyoshi,*1,2 and T. Imamura2
Recently, the influences of super solar flares on the earth
environment have been extensively investigated. One of theareas of focus in such investigations is the change ofchemical composition in the terrestrial atmosphere induced
by energetic particles generated in the super solar flares.
The bombardment of solar energetic particles (SEPs) to theatmosphere is called an SEP event, where a large amount of
X-rays, gamma-rays, protons, and heavier ions from thesurface of the sun intrude the terrestrial atmosphere. In
particular, high-energy protons come down into thestratosphere and induce dissociation of nitrogen molecules
followed by an increase of odd nitrogen oxides (NOx) andreactive odd nitrogen species (NOy). Consequently, theincrease of NOx and NOy affects the ozone concentration
over a period longer than SEP events.
We have performed simulations to investigate variation inchemical composition in SEP events by solving a large
number of rate equations for the concentrations of chemical
species in air.1) We adopt 77 chemical species including
ions and about 480 chemical reactions (ionic reaction
processes, neutral reactions, photolysis, etc.) in the present
simulation. A large number of ionic processes, including
recombination in the stratosphere, were treated for the firsttime, to the best of our knowledge. No transport processes
are taken into account. This model is referred to as the
Box-model hereafter. We carried out calculations using
commercial software for solving complex chemical reaction
systems (FACSIMILE, MCPA Software Ltd).
In order to estimate the yields of prompt products by the
SEP protons, we used the G-values (amount of products per
absorbed energy of 100 eV) investigated by radiolysis
studies2,3), based on the assumption that the prompt productyields are determined only by the energy deposit of the SEP
protons in air. The prompt products are assumed to be
charged products (positive atomic ions, positive molecularions, and electrons) and neutral products (ground-state andthe metastable atoms) generated from nitrogen and oxygen
molecules in air. The energy deposit was estimated using
the calculations of ion-pair creation by the SEP protons4).
During an SEP event, both the photochemical reactions
induced by the UV and visible radiation from the sun andthe reactions induced by the SEP protons are considered in
the simulation. The variation in chemical composition in an
SEP event is estimated as the difference between the result
obtained through simulation including the radiolysis
processes due to the SEP protons and that obtained underconsideration of only photochemical reactions using thesame initial condition.
1
2

RIKEN Nishina Center
National Institute for Environmental Studies- 168 -

Figure 1 shows a tentative result of the variation in theozone concentration at the 50 km altitude in the northern
polar region for the SEP event in October-November 2003.
The energy deposit in the SEP event continued for six days.
A sharp decrease of the ozone concentration is observed
immediately after the SEP event starts. On the third day ofthe event, when the energy deposit also reaches the
maximum, the decrease of the concentration reaches the
maximum and increases back gradually after that. The
ozone concentration does not completely recover andremains depleted for a few weeks or more. This depletion of
the ozone presumably corresponds to a very slow recoveryof the NOx concentrations. The NOx concentration begins
to increase when an SEP event starts. It continues toincrease for four days and is almost maintained constantafter the SEP event. The depletion of ozone is thought tocontinue after the SEP event since the ozone is consumed in
the catalytic reaction cycle involving NOx, e.g., NO+O3!
NO2+O2.
In the near future, we will investigate the global andlong-term influence of SEP events on the atmosphericchemical composition. In our approach, we will estimate
short-term variations during an SEP event using ourBox-model, and the estimated variations will then be input
into a three-dimensional (3D) chemical climate model(CCM)5) as instantaneous perturbation of the chemicalcomposition. This is because the transport of chemical
species treated in 3D is essential for investigating the global
and long-term influence.

Figure 1. Tentative result for the variation in the ozone
concentration at the 50km altitude caused by SEP (see text).
References

1) For the early-stage model: K. Sekiguchi et al., RIKEN Accel.
Prog. Rep. 46, 124 (2013).
2) C. Willis and A. W. Boyd, Int. J. Radiat. Phys. Chem. 8, 71(1976).
3) H. Mätzing, Adv. Chem. Phys. LXXX, 315 (1991).
4) C.H. Jackman et al., Atmos. Chem. Phys. 8, 765 (2008).
5) H. Akiyoshi et al., J. Geophys. Res. 114, D3, 16 (2009).

Ⅱ-7. Astrophysics and Astro-Glaciology

RIKEN Accel. Prog. Rep. 48 (2015)

Measurements of nitrogen isotope ratios in samples with very low nitrateconcentrations from the Dome Fuji ice core (Antarctica) drilled in 2010
Y. Motizuki,*1 S. Okamoto,*1, *2 K. Takahashi,*1 Y. Nakai,*1 A. Makabe,*3, *4 K. Koba,*3 and H. Motoyama*5
Nitrate (NO3–) in ice core samples is known to provide avariety of information on past and present atmosphericconditions. For instance, NO3– data for samples from theTalos Dome ice core (Antarctica) exhibited a highly
significant relationship with cosmic ray fluxes.1) In addition,
several research groups2),3) have measured the δ15N of NO3–
in surface snow in Antarctica to quantify the extent ofisotopic fractionation due to photolytic processes after
precipitation. However, there is little information available
about the depth profiles of the δ15N of NO3– in ice coresamples from Antarctica.
Our goal was to precisely analyze the δ15N and δ18O ofNO3– in ice cores to clarify the history of solar activity andcosmic events. However, it is difficult to measure the δ15Nand δ18O of NO3– in Antarctic ice cores because the NO3–
concentrations are low (typically <0.4 μmol/L), and theavailable sample volume is limited. In this study, as afeasibility study, we used a denitrifier method4) to perform
highly sensitive measurements of the δ15N of NO3– insamples from the DFS10 ice core, which was drilled in
2010, 7 km south of Dome Fuji Station (DFS), to obtain aprofile of the δ15N of NO3–. The NO3– concentration in thecore was approximately 0.35 μmol/L. In what follows, wewill introduce the outline of the results for 70 samples
collected from the ice core of depths of Dome Fuji at
3.3–7.6 m. The sampling procedure was the same as that
described by Motizuki et al. (2014)5) for the ice core drilled
at Dome Fuji in 2001. We assume that these samples
correspond to approximately the time interval from AD
1900 to 1960. Each sample segment cut from the ice core
corresponds to a time interval of approximately 0.7–1.0 year.
A 10 mL aliquot of each sample was used; NO3– in thesample water was quantitatively converted to N2O by the
denitrifying bacteria, Pseudomonas aureofaciens, whichlack N2O reductase. The isotopic composition of the N2O
gas produced by the bacteria was measured using a mass
spectrometer (IsoPrime100) with a purge-and-trap
introduction system. The isotope ratios were referenced tothe internationally recognized standards USGS32, USGS34,
and USGS35 provided by IAEA (International Atomic
Energy Agency). Nitrate concentrations were analyzed byion chromatography (ICS2000) with error limits of 2 or 3%.
The amount of nitrogen used for the analysis ranged from
2.1 to 4.8 nmol. δ15N ranged from 144.8 to 332.0‰ and the
RIKEN Nishina Center
National Institute for Environmental Studies＊3＊3
Tokyo University of Agriculture and Technology＊4＊4
JAMSTEC＊5＊5National Institute of Polar Research
＊1
＊1
＊2
＊2

maximum error was ± 2.5‰. The high, positive δ15N values
obtained in the study were therefore attributed to a
post-depositional effect on NO3–. Figure 1 shows the depth
profiles of NO3– concentrations and δ15N values. Despite
the lack of any correlation between NO3– concentrationsand δ15N values, their depth profiles appear to be related forseveral depth intervals. For example, both profiles areconvex in the depth intervals 3.3–4.0 and 5.5–6.0 m. It has
been reported that NO3– concentration decreases as δ15N
values increases near the surface of snow because ofphotolysis in the surface snow (vide supra).2) There was no
negative correlation between NO3– concentration and δ15N
values for our ice core samples, which indicates that thevariations of δ15N and NO3– concentration in ice coresamples below 3 m do not reflect post-depositional
fractionation of nitrogen isotopes. Instead, the depth
profiles of δ15N and NO3– concentration likely preserve thecorresponding variations in the original precipitation.
-

15

NO3 [μmol/L]δ N [‰]

15

δ N (‰)-

NO3 (μmol/L)

Depth [m]Fig. 1 The depth profiles of δ15N and NO3– concentration.
We intend to continue the measurements of nitrogen andoxygen isotopes in NO3– for samples collected from deeper
in the ice core. We expect that the depth profiles of nitrogenand oxygen isotopes will reflect the variations in thechemical and physical characteristics of past precipitation,
indicate the origin of the NO3– production in thestratosphere, and provide important information that will
help elucidate the history of solar activity and cosmic
events.

References

1) R. Traversi et al.: Solar Phys. 208, 237 (2012).
2) T. Blunier et al.: Geophys. Res. Lett. 32, L13501 (2005).
3) M. Frey et al.:Atmos. Chem. Phys. 9, 8681 (2009).
4) M. MacIlvin and L. Casciotti: Anal. Chem. 83, 4905 (2011).
5) Y. Motizuki et al.: Cryosphere Discuss. 8, 769 (2014).

- 169 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-7. Astrophysics and Astro-Glaciology

X-ray and Optical/UV Correlation Studies of Active Galactic Nuclei
H. Noda,∗1 and T. Minezaki,∗2 on behalf of the AGN Optical–X-ray Monitoring Collaboration
Almost all galaxies in the universe are considered
to harbor, at their center, a supermassive Black Hole
(BH) with a mass of ∼ 105−10 M , where M is Solar
mass. In Active Galactic Nuclei (AGNs), a considerable amount gas accretes onto the BH, and multi wavelength signals, including optical, UV, and X-ray, aregenerated with bolometric luminosity of ∼ 1040−46 erg
s−1 . The X-ray is presumably generated, via inverse
comptonization in high-temperature electron clouds(coronae) formed near the BH, while the optical/UVemissions via black body processes of an optically thickand geometrically thin accretion disk extending out tofarther radii from the BH. Although a combinationof the accretion disk and coronae has been known as“the central engine” creating a large amount of energy
in AGNs, its properties including geometries, physicalconditions, and heating mechanisms are still unclear.
Applying a timing method1) to Suzaku 2) data of an
AGN called NGC 3227, we found that a Hard PrimaryComponent (HPC) dominated X-ray emission in the
faint phase, while a Broad-band Primary Component(BPC) appeared in addition to the HPC in the brightphase (Fig. 1a). This demonstrates that at least two
X-ray emitting regions with distinct properties exist(a)

Faint phase

Bright phase
HPC

HPC

νFν

BPC
Reprocessed X-ray

2

Reprocessed X-ray

45 2
Energy (keV)

45

UV (~1500 Å) count rate (cnt/s)

10
9.5

(b)

9
8.5
8

BPC + HPC
Only HPC

7.5
7
6.5
6

0

0.5 1
1.5 2
2.5 3
2-10 keV count rate (cnt/s)

Fig. 1. (a) Spectral components of NGC 3227 in the faint(left) and bright (right) phase3) . (b) A plot between
fluxes in the 2–10 keV and UV bands. Systematic errorsof the Swift detectors were not included in the errors.
∗1∗2

RIKEN Nishina Center
Institute of Astronomy, School of Science, The University ofTokyo- 170 -

near a BH, and one emitting the HPC is always visible,
while the other radiating the BPC shows up only when
the amount of accreting gas is large3) . However, thegeometries of the HPC and BPC creating regions canbe hardly identiﬁed with only the X-ray information.
To study the geometries, we focus on correlations
between the ﬂuxes of primary X-ray and optical/UV,
because a better correlation possibly reﬂects a stronger
geometrical connection of an X-ray radiating region
with the accretion disk. In 2013–2014, we performed
optical and X-ray simultaneous monitoring on an
AGN called NGC 3516 with Suzaku and ﬁve Japaneseground-based telescopes. As a result, a signiﬁcant correlation was discovered between ﬂuxes of HPC and theoptical signals. The result will be discussed elsewhere.
Optical–UV data derived by Swift 4) are useful aswell. Almost all Suzaku observations of NGC 32273)
were simultaneously followed up by Swift; therefore
X-ray ﬂux in the faint and bright phase, identiﬁed by
Suzaku (Fig. 1a), can be individually compared withthose in optical/UV. First, we extracted UV countrates from a 5”-radius circle centering at the nucleus on
UV images obtained with the UVW2 ﬁlter. Next, we
extracted 2–10 keV count rates from the Suzaku andSwift datasets derived at the same time as the UV images. Figure 1(b) shows a count-count plot between the
UV and X-ray count rates with diﬀerent colors between
the faint (purple) and bright (green) phases. When
we ﬁtted the faint-phase plots (Fig. 1b purple) witha linear function, including systematic errors of 3%
into the UV count rates, the ﬁt almost succeeded with
χ2 /ν = 13.4/6. However, in ﬁtting all the plots (Fig.
1b purple plus green) again with a linear function, after
including the 3% systematic errors into the UV countrates, the result degraded giving χ2 /ν = 61.5/9. Thismight indicate that the HPC ﬂux is strongly correlatedwith UV, while the BPC ﬂux is little correlated.
Because the HPC was found to deeply relate withblack body photons from the accretion disk, it may
come from an hot accretion ﬂow, and if so, the faintphase corresponds to the low/hard state5) . On theother hand, the origin of the BPC still remains unclear, because it did not appear for long enough in theprevious observations of NGC 3516 and NGC 3227. To
examine the bright phase in detail, we perform another
X-ray and optical monitoring with Suzaku, and the systematic analyses of AGN data in the Swift archive.
References
1) H. Noda et al.: ApJ, 771, 100 (2013)
2) K. Mitsuda et al.: PASJ, 59, 1 (2007)
3) H. Noda et al.: ApJ, 794, 2 (2014)4) N. Gehrels et al.: ApJ, 611, 1005 (2004)
5) F. Yuan & R. Narayan: ARAA, 52, 529 (2014)

Ⅱ-7. Astrophysics and Astro-Glaciology

RIKEN Accel. Prog. Rep. 48 (2015)

Time-variable Fe K emission lines from accreting white dwarf binaries
T. Yuasa∗1
Accretion of gas from a normal star in a binary system onto a compact star liberates a vast amount ofgravitational potential energy. This often results inheating of the gas and high-energy electromagnetic radiation. By observing the emission, properties of thecompact star can be studied because the emission occurs from regions close to the star.
We have been studying the mass-accreting whitedwarf system that is considered to be an importantcandidate of type Ia supernovae. In particular, our focus has been on measuring the mass of a white dwarf ina binary system by modeling of X-ray spectra of heatedgas. For details of the modeling and initial results, see
our previous publication (Yuasa et al. 2010).
To further improve the accuracy of the mass measurement, it is crucial to understand the geometry andprofiles of density, temperature, and bulk velocity of
the X-ray emitting plasma. In April 2014, we wereawarded a 180k-second observation of the magnetic accreting white dwarf V1223 Sgr by using the Japanese
Suzaku X-ray telescope. The aim of the observation is
to assess the geometry assumed in the model calculation based on precise measurement of time variation of
Doppler energy shifts and intensities of the Fe atomic
lines after the previous marginal report (Hayashi et al.
2011).
After the standard data selection, we obtained highphoton-statistics spectrum as presented in Fig. 1.
To disentangle Doppler energy shifts of lines caused
by in-falling bulk velocity of the X-ray emitting gas
and other effects such as white dwarf spin and subsequent line-of-sight viewing angle variation, we performed phase resolved spectral fitting by splitting thetotal observation time into four phase bins with a period of 754 s (corresponding to the spin period of thewhite dwarf in V1223 Sgr). No statistically significant
time variation was observed for the centroid energiesof the lines, in contrast to the previous report (Hayashi
et al. 2011), due to long-term degradation of the energy resolution of the instrument. On the other hand,
as shown in Fig. 2, the line intensities varied over spin
phases although statistical fitting errors are still large
due to phase resolving (resulting shorter integration
time per phase bin).
These time variations can be interpreted to becaused by the resonance-trapping beaming effect (Terada et al. 2001) where the optical thickness of the
X-ray emitting hot plasma becomes greater than unity
only for resonance line photons and trapped within theplasma while continuum photons exit the plasma region almost freely (i.e. the plasma is optically thin for∗1

RIKEN Nishina Center- 171 -

continuum photons). In this scheme, the optical thickness is sensitive to the plasma density, the geometricalshape, and the white dwarf mass. Therefore, we arecontinuing to perform detailed analyses and comparison with Monte Carlo radiation transfer simulation
results to utilize this resonance-beaming feature as analternative constraint for measuring the white dwarf
mass and related physical quantities of the binary system such as the mass accretion rate.

Fig. 1. Time-average X-ray CCD spectrum of V1223 Sgr.
Thermal bremsstrahlung continuum and three atomic
emission lines from neutral Fe (6.4 keV) and highly ionized Fe ions (6.7 and 6.9 keV).

Fig. 2. Crosses are intensities of the three Fe emission lines
over white dwarf spin phases (ordinate presents theequivalent width, which is a measure of the line intensity). Solid curves are the best-fit sinusoidal functions.

References
1) Yuasa T., et al. 2010, A&A, 520, A25
2) Hayashi T., et al. 2011, PASJ, 63, 739
3) Terada Y., et al. 2001, MNRAS, 328, 112

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-7. Astrophysics and Astro-Glaciology

Spectral and Temporal Approach to Physics of Neutron Stars
T. Enoto,∗1,∗2,∗3 T. Tamagawa,∗1 T. Kitaguchi,∗1,∗4 A. T. Hayato,∗1 T. Yuasa,∗1
W. B. Iwakiri,∗1 H. Noda,∗1 A. Yoshikawa,∗1 Y. Takeuchi,∗1 M. Kubota,∗1 and K. Nishida∗1
Astronomical observations of neutron stars provide
us an unique approach to investigate the fundamental physics under extreme condition. Degenerate matter inside neutron stars exceeds the nuclear density,and the equation of state of high density matter is observationally constrained via measurements of stellar
mass and radius. Neutron stars are also characterized by strong gravity (gravitational redshift z ∼ 0.2),
fast rotation (up to P ∼ 1 ms), and strong magnetic
ﬁeld (B ∼ 108 T). Recent progress of X-ray observations further indicates an strongly magnetized subclassof neutron stars, called magnetars1) . There are accumulating evidence for 2–3 orders of magnitude higher
magnetic ﬁeld than that of canonical neutron stars,
with peculiar ﬂare and burst activities interpreted as
dissipation of the magnetic energy2) . Neutron stars
are, thus, an ideal laboratory in our universe3) .
We are now about to enter the age of precise astrophysical measurement of neutron stars. The ASTROH X-ray observatory4) , expected to be launched in2015, will realize a ultra-high spectral resolution ofE ∼ 7 eV in the ∼0.3–10 keV band (cf., ∼130 eV
FHWM at 6 keV of the X-ray CCD onboard Suzaku).
This will enable us to search for a proton cyclotronfeature as direct evidence for the strong ﬁeld and for agravitationally-redshifted absorption feature to determine the equation of state of neutron stars. One year
after the ASTRO-H, the Neutron star Interior Composition Explorer (NICER)5) will be attached to the Inmagnetic
axis

rotationaxis
Hard X-rays frommagnetosphere?

poloidal (dipole)magnetic field

References

Soft X-rays fromhot spots on the
neturon star surface

toroidalmagnetic field

Short burst
emission during
an active state
reconnection?
short burst?
hot spot

Fig. 1. Schematic view of a magnetar, a subclass of neutronstars with extremely strong magnetic field.
∗1
∗2
∗3
∗4

ternational Space Station (ISS). The NICER projectwill provide us unprecedented high-timing resolution
data of neutron stars with very large photon statistics, and is expected to reveal the equation of state ofneutron stars. In addition to these spectral and temporal improvements, polarization is expected to open
a new observational window of the X-ray astronomy.
The Gravity and Extreme Magnetism Small Explorer(GEMS)6) , the ﬁrst polarization-dedicated X-ray satellite, was re-proposed in 2014 with a new name.
Prior to the ASTRO-H launch, we have started investigations of scientiﬁc topics and possible candidatesof observations, and published it as the ASTRO-H
White Paper7) . Hard X-ray from magnetars is listed
as one of the good candidates of ASTRO-H8) . We arealso preparing the handbook for the high spectral data
handling, called the “Cookbook”. As international cooperation for future missions, we have also collaborated with the NICER and X-ray polarimeter groups
at NASA Goddard Space Flight Center, mainly contributing to calibration of the NICER X-ray mirror anddevelopments of the X-ray polarimeter9) . As our collaborative relationship grows, FUture Cooperation is a
Key element for the Spectral and Temporal Approachto Physics for neutron stars.
In 2014, we reported a signature of the toroidal
ﬁeld embedded in the magnetar interior10) from
4U 0142+61 (see Fig 1), and also studied how neutrino emission coupled with the toroidal ﬁeld aﬀects
spin evolution of neutron stars11) . We studied themagnetic ﬁeld and accretion mechanism of the slowest
rotating X-ray pulsar, 4U 1954+31912) , and iron line
emission from the prototypical X-ray pulsar, Herculis
X-1 (Her X-1)13) .

RIKEN Nishina Center
JSPS SPD Fellow
NASA Goddard Space Flight Center
Department of Physical Science, Hiroshima University- 172 -

1) C. Thompson et al: MNRAS, 275, 255 (1995)
2) T. Enoto et al.: PASJ, 62, 475 (2010)3) A. S. Burrows et al: PNAS, 111, 2409 (2014)4) T. Takahashi, K. Mitsuda, R. Kelley, et al: Proc. of the
SPIE, 8443, 84431Z (2012)5) K. C. Gendreau, Z. Arzoumanian, & T. Okajima: Proc.
of the SPIE, 8443, 844313 (2012)6) K. Jahoda: Proc. of the SPIE, 7732, 77320W (2010)7) S. Kitamoto, T. Enoto, S. Safi-Harb, et al:arXiv:1412.1165 (2014)8) T. Enoto et al: ApJ, 722, L162 (2010)9) T. Enoto et al: Proc. of the SPIE, 9144, 91444M (2014)
10) K. Makishima, T. Enoto, J. S. Hiraga, et al: Phys.
Rev. Lett., 112, 171102 (2014)11) Y. Suwa, & T. Enoto: MNRAS, 443, 3586 (2014)12) T. Enoto et al: ApJ, 786, 127 (2014)
13) F. Asami, T. Enoto, et al: PASJ, 66, 44 (2014)

Ⅱ-7. Astrophysics and Astro-Glaciology

RIKEN Accel. Prog. Rep. 48 (2015)

Timing analysis of solar flares in hard X-ray and soft γ-ray bands
measured by the Suzaku Wide-band All-sky Monitor
W.B. Iwakiri,∗1 on behalf of Suzaku WAM teamHard X-ray and γ-ray observations have proved to bea powerful tool to for studying the physics of particle
acceleration and transfer in solar ﬂares. These highenergy photons are often observed in X class ﬂares deﬁned by the GOES satellite. The origin of emission isthought to be the thick-target bremsstrahlung of highenergy particles accelerated by magnetic reconnection.
Previous observations have revealed that the arrival
times of hard X-ray photons (20 - 200 keV) dependon their energy1) . The energy-dependent time delays
can be explained through the trap plus precipitation
model1) . First, the model suggests that electrons accelerated by magnetic reconnection are injected intoa magnetic loop and trapped (magnetic mirror trap).
Next, the trapped electrons escape the loop by pitchangle scattering and precipitate to the chromosphere.
As a result, hard X-ray photons are produced by thicktarget bremsstrahlung. If Coulomb collisions represent
the dominant pitch angle scattering for trapped electrons, the collisional deﬂection time τ can be represented as2)
τ (E) ∝ E 1.5 .

(1)In this progress report, we performed a timing analysisof the Sept 24 2011 solar ﬂare observed by the Wideband All-sky Monitor (WAM)3) onboard Japanese ﬁfth
X-ray satellite Suzaku from 80 keV to 7 MeV.
The WAM consists of four lateral walls composed of

bismuth germanium oxide Bi4 Ge3 O12 (BGO) crystals.
The event data are recorded with a 1-s time resolution
in the 55 energy band. The WAM has a large eﬀective
area that reaches 400 cm2 at 1 MeV. This is the largest
area in among currently working γ-ray spectrometers
on-board astronomical satellites. Therefore, WAM is
suitable for hard X-ray and soft γ-ray observation ofsolar ﬂares4) . Figure 1 shows the energy-resolved time
proﬁles of the solar ﬂare on Sept 24 2011 observed by
WAM. The lightcurves show that the main peak has
shifted progressively later at the higher energy band.
In order to evaluate the time lag quantitatively, wemeasured the delay using a cross correlation techniquebetween the 80 - 130 keV lightcurve and the other eightenergy-resolved lightcurves (130 - 7000 keV band). Before the analysis, we used a low-pass ﬁlter for eachlightcurve by running an average of 10 bins (the time
bin size is 1 s) to exclude the higher frequency component, because the observed fast structures are causedby the diﬀerence of electron time-of-ﬂight from directly
precipitating electrons1) . The derived time delays as afunction of energy are shown in Fig.2. The results show
the energy dependence of the time delays are clearlychanged around 1000 keV. In the lower energy band,the relation is roughly consistent with E1.5 , which ispredicted by the pitch angle scattering of Coulomb
collision2) . On the other hand, above 1000 keV, therelation becomes more ﬂat. If we ﬁt the results using
the broken power-law model and the power-law index
of the lower energy is ﬁxed at 1.5, the derived index
of the higher energy band is 0.253±0.008 with a cutoﬀ
energy of 598±9 keV (the errors are 90% conﬁdence).
The estimation of systematic errors caused by a pileup eﬀect is currently in progress.

Fig. 2. The measured energy-dependent time delay of theSept 24 2011 flare using the cross correlation method.
Fig. 1. Background-subtracted lightcurves of solar flare
triggered on Sept 24 2011 09:35:00 UT observed by
Suzaku-WAM in nine energy bands.
∗1

RIKEN Nishina Center

References
1) M. J. Aschwanden et al: ApJ, 487, 936 (1997)
2) D. B. Melrose, & J. C. Brown: MNRAS, 176, 15 (1976)
3) K.Yamaoka et al: PASJ, 61, 35 (2009)4) A.Endo et al: PASJ, 62, 1341 (2010)- 173 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-7. Astrophysics and Astro-Glaciology

Spurious shear from tree-rings on LSST CCD
Y. Okura,∗1,∗2 , A. Plazas,∗3,∗4 , M. May∗3 and T. Tamagawa∗1
Charge-COupled Device(CCD) detectors in observational instruments are composed of a silicon layer,
which changes photons from astronomical objects into
electrons. The electron signal is ampliﬁed and contains information about the objects. Impurity gradients in the silicon that originate when it is grownproduce transverse electric ﬁelds that bend the electron path. The bending creates ﬂux modulation, position displacement and shape distortion of objects. The
tree-ring eﬀect is caused by circularly symmetric impurity gradients in the silicon wafer., which induce ﬂux
modulation, position displacement, and shape distortion of the observed astronomical objects. The treering eﬀect in some recent observational instruments(DESa) , HSCb) ) are smaller than the pixel scale, inducing small changes in object images. Future highprecision cosmology by the LSSTc) needs high precision measurement of astronomical objects. One of themethods for studying cosmology is the measurementof weak lensing shear (Schneider et al., 20061) ), whichchanges the shape of the image of objects from a large
scale structure (cosmic shear). Statistics of the cosmic
shear depend on the cosmological parameters, whichcharacterize the initial state and future of the Universe. However, the tree-ring eﬀect causes systematic
error in the measurement because it changes the shapeof images (Plazas et al., 20142) ). We studied the impact of the tree-ring eﬀect on the LSST test CCDs forhigh-precision cosmology.
We are the ﬁrst to quantify the tree-ring eﬀect on the
LSST prototype sensors. We used ﬂat images that contain data taken with uniform illumination where concentric ﬂux modulation (tree rings) can be observed.
We found the center of the tree-ring eﬀect near thecorner of the CCD (Fig. 1) and measured teh onedimensional proﬁle by averaging by angle (blackline in
Fig. 2). If the ﬂux modulation or position displacement are concentric, shape distortion(spurious shear)can be obtained (Okura et al in preparation) as
1
TR
γrad
(r) ≈ − f (r),2of the spurious shear is 0.005%, it is much smaller thanthe cosmic shear which has typical scale of approximately 1-2 %.
Next, we calculated the two-point correlation of the
spurious shear because, in cosmological analysis, we
calculate the two-point correlation of the cosmic shear
for obtaining the statistics of the cosmic shear. Figure 3 shows the two-point correlation of the spurious
shear in the ﬁeld of view of LSST (189 CCDs, 60000 ×60000 pixels) with a sampleing scale of 50 pixels. The
typical scale of the correlation is approximately 10−13 ,which is much smaller than the two-point correlation of
the cosmic shear(10−6 ). Therefore, the tree-ring eﬀect
on the LSST CCDs will not degrade the constrainingof the cosmological parameters.

Fig. 1. Tree-ring pattern on the LSST CCD

Fig. 2. One-dimensional proﬁle of the ﬂux modulation(black) and spurious shear (blue) caused by the treering eﬀect on the LSST CCD.

(1)

TR
where f (r) and γrad(r) are the proﬁles of ﬂux modulation and spurious shear, respectively. We show themeasured spurious shear in Figure 2, and the blue line
indicates the measured spurious shear. As typical scaleFig. 3. Absolute values of two-point spurious shear correlation caused by the tree-ring eﬀect on the FOV of the
LSST CCD. Black points indicate parallel correlation,and blue points indicate cross correlation with 50-pixels
sampling. Non-absolute values oscillated about zero.

∗1

References

∗2
∗3
∗4
a)

b)
c)

RIKEN Nishina Center
RIKEN BNL Research Center
Brookhaven National Laboratory
Jet Propulsion Laboratory
http://www.darkenergysurvey.org
http://www.naoj.org/Projects/HSC/HSCProject.html
http://www.lsst.org

1) P. Schneider., Part 1: Introduction to gravitational lensing and cosmology, Springer-Verlag Berlin Heidelberg,(2006)
2) A. A. Plazas, G. M. Bernstein, E. S. Sheldon, PASP,
Volume 126, issue 942, (2014) pp.750-760- 174 -

Ⅱ-7. Astrophysics and Astro-Glaciology

RIKEN Accel. Prog. Rep. 48 (2015)

Performance test of TPC Polarimeter for cosmic X-ray sources at BNL NSLS-1
W.B. Iwakiri,＊1 K. Black,＊2 T. Kitaguchi,＊1 J. Hill,＊2 K. Jahoda,＊2 T. Enoto,＊1,＊2 T. Tamagawa,＊1,＊3 Y. Takeuchi,＊1,＊3
M. Kubota,＊1,＊3 H. Marlowe,＊4 R.Cole,＊4 K. Nishida,＊1,＊3 and A.Hayato＊1
Cosmic X-ray polarimetry is believed to be a powerfulmeasurement technique for studying the physics in extreme
environments such as strong gravitational fields andmagnetic fields in the universe. However, soft X-ray
polarization has not succeeded so far except for a few
detections in the 1970’s 1). To study such an unexploited
field, NASA and RIKEN have been developing an X-ray
polarimeter that employs the Time Projection Chamber(TPC) technique2). In this progress report, we discuss theperformance test of a TPC polarimeter with a new Read Out
Board (ROB) design3).
When an incident X-ray interacts with a gas atom, aphotoelectron is ejected preferentially in the direction of theelectric field vector of the incident photon according to acosine2 probability distribution. Thus, we can determine thepolarization degree and the phase by obtaining a track
image and initial direction of the photoelectron. A
schematic view of TPC polarimeter is shown in Fig 1. To
ensure high efficiency for the polarization signal, the charge
detection plane of the TPC polarimeter consists of the Gas
Electron Multiplier (GEM) designed by RIKEN4) mounted
over strip anodes parallel to the incident X-rays.
Two-dimensional images of photoelectron are created using
a one-dimensional strip readout and by timing the arrival of
charge2). For a small satellite mission of cosmic X-ray
polarimetry, we have proposed two different ROB designs.
One design uses two gold-plated titanium frames with“tongue in groove” to secure the strips under tension3). The
performance of the polarimeter using this type of ROB has
been verified and meets all mission requirements5). To
reduce cost and risk by further simplifying the assembly
more, the other design one has used epoxy adhesives tohold the strips under tension to the lower frame.
We carried out the performance test for the polarimeter at
the Brookhaven National Laboratory (BNL) SynchrotronLight Source-1 facility in September 2014. The polarimeter
was filled with 190 torr dimethyl ether (DME). To make thepixels of the track image square-shaped, the electrical drift
region was selected as 196 V/cm, which is the drift velocity
equal to the 121 μm divided by the 50 ns sampling time.
The transfer field between the GEM and the ROB was
selected as 660 V/cm considering the collection efficiencyof the charge. The detector was irradiated withliner-polarized monochromatic X-rays at eight energy bands.
The total number of the events is 5 × 104 for individual
measurement. Further, to calibrate the polarimeter, we alsoacquired 2.7 keV unpolarized events.
Fig.2 shows the derived modulation curves for threeenergy bands and the 2.7 keV unpolarized data at 8 mmfrom GEM, which corresponds to the detector optical axis.
The results have subtracted the pedestal and common modenoise and deconvolved the electronics response. The S/Nachieved 5 σ levels. To correct the asymmetry caused by thedifference of the drift velocity between the drift and thetransfer region, the results are corrected using Gaussianconvolution in the time axis. The Gaussian σ value is 46 μm
which is optimized using the 2.7 keV unpolaraized data5).
As an indicator of the polarization sensitivity, we introduce
a modulation factor μ , which is defined as

μ = (fmax – fmin) / (fmax + fmin),where fmax and fmin are maximum and minimum values ofthe modulation curve, respectively. The derived modulation
factors of 2.7 keV, 4.5 keV, and 6.4 keV are 21.3±0.6%,
37.9±0.6%, and 46.6±0.6%, respectively. The results are
consistent with previous ROB design5) and meet themeasurement requirement. The estimation of the systematic
error for the detector position is still under discussion.

Fig. 2. Modulation at three energy bands measured at BNL
using TPC polarimeter.
Fig. 1. Schematic view of the TPC polarimeter2,3)
RIKEN Nishina Center＊2
NASA Goddard Space Flight Center＊3
Department of Physics, Tokyo University of Science＊4
Department of Physics and Astronomy, University of Iowa
＊1

References

1) M.C.Weisskopf et al: ApJL, 220, L117 (1978)
2) K. Black et al: NIMPA, 581, 755 (2007)
3) J. Hill et al: Proc. of the SPIE, 9144 , 91441N (2014)4) T. Tamagawa et al: NIMPA, 608, 390 (2009)5) T. Enoto et al: Proc. of the SPIE, 9144, 91444M (2014)- 175 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-7. Astrophysics and Astro-Glaciology

Fabrication of a TPC X-ray Polarimeter and Preliminary Testingwith the Synchrotron Radiation Light Source at Spring-8
A. Hayato,∗1 T. Tamagawa,∗1 T. Kitaguchi,∗1,∗2 E. Teruaki,∗1,∗3 W. B. Iwakiri,∗1
Y. Takeuchi,∗1,∗4 M. Kubota,∗1,∗4 and K. Nishida∗1,∗2

∗1
∗2
∗3
∗4
a)

larized source. The first step of our study is to determine µpol of the RIKEN polarimeter.
We performed two experiments: (a) to measureµ with highly (∼85%) polarized source at BL32B2
SPring-8, and (b) to confirm the flat modulation with
unpolarized line emission produced by an X-ray generator. We took measurements at 4.5, 5.5, 6.4, 7.0, and7.5 keV for (a) and 4.5 and 6.4 keV for (b), although
we focus on only the result of the 4.5 keV data here.
Figure 2(a) shows the modulation curve taken withthe well-collimated (200×200 µm2 ) 4.5-keV polarized
X-ray at the middle height of the active volume, and(b) shows that with the 4.5-keV unpolarized X-ray under the same condition. The obtained µpol at 4.5 keV is0.3×0.85/pbeam , where pbeam is the polarization degreeof the X-ray beam, while the observed flat modulation
is 0.00±0.02. Meanwhile, the determination accuracy
for the polarization angle is about 4◦ at a certain drift
height. A detailed comparison with the GEMS polarimeter and other performance studies (e.g., detector
angle dependency for the sensitivity) are in progress.
(a) 4.5 keV(b) 6.4 keV

1 mm

CountsFig. 1. Charge-weighted photoelectron track image takenby the RIKEN polarimeter with a 6.4-keV X-ray, together with a reconstructed angle with the blue arrow.
800
700

800

(a) Polarized 4.5 keV

600

600

500

500

400

400

300

300

200

200

Nevt = 49980
μ = 26.31 ± 0.62 %Peak = -86.40 ± 0.68 deg
chi2=75.22 (dof=97)1000(b) Unpolarized 4.5 keV

700(

X-ray polarimetry is expected to provide unique information about stars, such as strong gravitational
fields around black holes. However, it is far behind intechnology in comparison to radio/optical polarimetry,
and the observation of Crab nebula by OSO-8 satellite
40 years ago has been the only detection of X-ray polarization among astronomical objects1) . NASA and
RIKEN have been developing the X-ray polarimeterusing the time projection chamber (TPC) techniquewith the sensitivity 10 times greater than the OSO-8
polarimeter, for the Gravity and Extreme Magnetism
Small explorer (GEMS), an X-ray polarization telescope missiona) . Although we have already built theflight model2) , a detailed study is still needed in orderto fully understand the characteristics of the TPC polarimeter. We therefore fabricated an in-house TPC
polarimeter at RIKEN (RIKEN polarimeter) for tests
in various situations. In this report, we present a brief
overview and the basic performance of the RIKEN polarimeter.
The TPC polarimeter is a gas-based detector withsensitivity in the energy range of 2 − 10 keV. The polarimeter can image a photoelectron and reconstruct
its initial direction, where the azimuth angle distribution depends on the linear polarization degree/angle ofthe incoming X-ray3) .
The design of the RIKEN polarimeter is originallybased upon the GEMS polarimeter4) , although handy
materials (e.g., bare aluminum instead of coppertungsten or gold-plated aluminum) are used for easiermachining. Another modification is that we adopted
the Scalable Readout System (SRS), manufactured by
CERN/RD51, instead of a custom-made ASIC as the
strip readout. A SRS consists of APV25(s) with a sampling rate of 40 MHz, ADC card(s), and a Front-End
Card. Figure 1 shows the photoelectron track takenby the RIKEN polarimeter.
What we actually measure with the polarimeter isa modulation curve, an azimuth angle distribution of
the photoelectron. The modulation factor µ is derived
from (fmax − fmin ) / (fmax + fmin ), where fmax andfmin are the maximum and minimum counts in the
curve. The modulation factor of the polarimeter µpol ,which represents the sensitivity of polarimetry, is defined as µ which should be measured with a 100% po-

-80

-60

-40

-20

Nevt = 50732
μ = 0.00 ± 1.82 %Peak = -45.60 ± 124.63 deg
chi2=129.72 (dof=97)

100

0

20

40

60
80
Angle (deg)

0

-80

-60

-40

-20

0

20

40

60
80
Angle (deg)Fig. 2. Modulation curve for 4.5 keV (a) polarized X-rayand (b) unpolarized X-ray taken with the TPC polarimeter.

References

RIKEN Nishina Center
Department of Physics, Hiroshima University
NASA Goddard Space Flight Center
Department of Physics, Tokyo University of Science
GEMS was canceled in 2012 regarding the cost.

1) M. C. Weisskopf et al.: ApJ, 208, L125 (1976).
2) J. E. Hill et al.: Proc. SPIE, 8433, 84331Q (2012).
3) K. Black et al.: NIMPA, 581, 755 (2007).
4) T. Enoto et al.: Proc. SPIE, 9144, 91444M (2014).

- 176 -

Ⅱ-7. Astrophysics and Astro-Glaciology

RIKEN Accel. Prog. Rep. 48 (2015)

Measurement of X-ray beam polarization of BL32B2 at SPring-8
using a Compton polarimeter
M. Kubota,∗1,∗2 T. Kitaguchi,∗1 A. Hayato,∗1 W. Iwakiri,∗1 T. Enoto,∗1,∗3 K. Nishida,∗1,∗2 Y. Takeuchi,∗1,∗2
A. Yoshikawa,∗1,∗2 and T. Tamagawa∗1

∗1
∗2
∗3

need to know the modulation factor, Msim , which is
100% for a perfect polarimeter and 0% for an insensitive detector. We estimate it using the Geant4 Monte
2 . The obtained parameters, µCarlo toolkit?)
obs , Msim ,and P , are listed in Table 1. The beam polarization
degrees at 4.5, 6.4, and 8.0 keV are estimated to be
75.9 ± 0.1%, 77.1 ± 0.2%, and 77.0 ± 0.1%, respectively.
Inthe hatch
hatch
In theSignalSignal cable
cable

Side
Side View
View

AMPTEKAMPTEK
PX5

Si
Si det.
det.

oscilloscope
oscilloscope

X-ray
X-ray

CdTe
CdTe
det.
det.

Front
Front View
View
0°
0°

Si
Si
detectordetector
Be
Be

90°
90°

CdTe
CdTe
detectordetector

AMPTEK
PX5

PC
PC

KOUZU
KOUZU
XZ Stage
XZ

Fig. 1. Experimental setup to measure the synchrotron Xray beam polarization. The two X-ray detectors are
the AMPTEK XR100CR Si detector and the XR100T
CdTe detector.
!22 / ndf
27.28 / 6
χ / ndf
27.28 / 6Prob
0.0001283
Prob
0.0001283
Offset79.17 ± 0.1156
Offset79.17 ± 0.1156
mu
69.21 ± 0.1322
mu
69.21 ± 0.1322
Peak (deg) -1.444 ± 0.07056
Peak (deg) -1.444 ± 0.07056

Count
(cps)
CountRate
Rate
(cps)
Rate
Rate(cps)(cps)

We develop a photoelectric tracking gas detector using a time projection chamber technique for a cosmic
1 . To calibrate the X-ray polarimeX-ray polarimetry?)
ter at a synchrotron facility, the polarization degree of
the incident X-ray beam should be known. In order tomeasure the beam polarization, we build a Compton
polarimeter based on the X-ray scattering processes,
where the angular distribution of the scattered X-rays
is sensitive to the polarization direction of the incident
X-rays. The Compton polarimeter can accurately measure the beam polarization owing to its high analyzing
power. We use the Compton polarimeter to measure
the beam polarization of the BL32B2 beamline at theSPring-8 synchrotron facility where the gas X-ray polarimeter is verified.
Figure 1 shows the schematic view of the experimental setup. The Compton polarimeter consists of acylindrical Be scatterer and two X-ray detectors, i.e.,a Si sensor and a CdTe sensor, that face each otheracross the scatterer. Each detector is located 1 cm
away from the Be scatterer and has a diameter of 4mm and an effective length of 4 mm. Incident X-rays
from left to right, as shown in Fig. 1, are scatteredby the Be cylinder and then detected by these sensors.
As the detectors rotate around the scatterer through arotation stage, the count rates modulate with the minimum rate in the direction of the electric field vector(i.e., the polarization direction) of the incident X-rays
and the maximum rate perpendicular to the vector.
The count rate shows a sinusoidal curve as a functionof the rotation angle (modulation curve). The polarization degree of the incident X-rays is derived fromthe modulation curve. We measure the polarization
degree of the incident X-rays at 4.5, 6.4, and 8.0 keV.
Figure 2 shows the modulation curve for 4.5 keV Xrays. The data points are fitted by a sinusoidal modelwith a constant offset: f (θ) = a ∗ cos(2 ∗ (θ − b)) + c,
where θ is the rotation angle. The free parametersa, b, and c represent the amplitude, polarization direction, and offset, respectively. The observed beampolarization degree, µobs , is calculated using the equation: µobs = a/c. We define zero degree in the detector
coordinate system when the Si detector is on top. In
order to reduce the systematic error caused by beam
misalignment, we calculate the average of the countrates obtained from two angles 180 degrees apart fromeach other. To calculate the beam polarization, P , we

180
180
160
160
140
140
120
120
100
100
80
80
60
60
40
40
20
20
0
0 0
0

20
20

40
40

60
60

80
80

100
100

120
120

140
140

160
180
Angle
160 (deg)
180

Angle
(deg)
Rotation Angle(degree)Rotation Angle (degree)

Fig. 2. Modulation curve of polarized X-rays with an energy of 4.5 keV. The red line indicates the best-fit
model.
Table 1. Summary of the observed modulation (µobs ), simulated modulation factor (Msim ), and beam polarization (P )
E
(keV)
4.5
6.4
8.0

µobs
(%)
69.2 ± 0.1
70.6 ± 0.2
72.1 ± 0.1

Msim
(%)
91.21 ± 0.10
91.62 ± 0.05
93.67 ± 0.02

P(%)
75.9 ± 0.1
77.1 ± 0.2
77.0 ± 0.1

References

RIKEN Nishina Center
Department of Physics, Tokyo University of Science
NASA/GSFC

1) K. Black et al: NIM A, 581, 755 (2007)2) S. Agostinelli, et al: NIM A, 506, 250 (2003)- 177 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-7. Astrophysics and Astro-Glaciology

Performance test of Modulated X-ray Source using UV-LED and
Channel Electron Multiplier
W.B. Iwakiri,∗1 K. Gendreau,∗2 A. Hayato∗1 Y. Takeuchi,∗1,∗3 K. Nishida,∗1,∗3 M. Kubota,∗1,∗3
and T. Tamagawa∗1
A Modulated X-ray Source (MXS) with Channel
Electron Multiplier (CEM) developed by NASA isa newtype of X-ray generator that uses UV-LED1) .
MXS has many advantages compared with radioactive
sources or X-ray generators that require hot ﬁlaments.
For example, the timing of the X-ray output can becontrolled using the modulated LED. Moreover, electronic ampliﬁcation by CEM leads to the generation ofshort X-ray pulses (tens of nanosecond). These advantages make the calibration of an X-ray detector considerably easy. For example, we can determine the drift
velocity of an electron in a gas using high-precision
X-ray photon emission timing. It is important to calibrate an X-ray polarimeter using the Time Projection
Chamber technique2) . In this progress report, we show
the performance of MXS with CEM.
A basic layout of MXS with CEM is shown in Fig
1. When an UV-photon emitted from an LED hitsa photocathode, the photon converts to a photoelectron. The photoelectron is accelerated onto a target
through a potential diﬀerence and it produces an Xray. In fact, the modulation of the LED provides modulated photoelectron and it leads to the generation ofmodulated X-rays eventually. The X-ray spectrum canbe controlled by choosing the target material and theacceralating potential. To amplify the photoelectron,i.e., to obtain a high X-ray ﬂux, CEM is set between aphotocathod and the target. Figure 2 shows the MXS
made at RIKEN. The assembly is based on the SUS304
cuboid that is 67×34×34 mm. We adopted MgO as thephotocathode and Ti as the target.
To verify the performance of the MXS quantitatively, ﬁrst, we checked the output X-ray ﬂux. The
pressure in the MXS is set at 10−7 torr with pumping.
The voltage of the CEM and target are set as −2.25
kV and 10 kV, respectively. The frequency of the input pulse is ﬁxed at 10 kHz. We used a Si detector,
AMPTEK XR100CR, to evaluate the output X-ray.
Figure 3 (left) shows the relation between the widthof the input pulse with 10 kHz for the LED and theoutput X-ray ﬂux. The results show that these twoparameter have a linear relationship. When the widthof the input pulse is 500 ns, the observed X-ray ﬂux is4000 counts/s/msr.
Next, we evaluate the duration of the output X-ray
pulse using a Time-to-Digital Converter (TDC). We
measured the time interval between the leading timeof input pulse for LED (used as the start signal of theTDC) and the arrival time of the output X-ray photon(used as the stop signal of the TDC). Figure 3 (right)
shows the derived TDC histogram at 5 diﬀerent widthsof the input pulse (50, 100, 200, 400, and 600 ns). The
bin size of the histograms are 62.5 ns. The width ofeach histogram corresponds to the pulse width of theoutput X-rays. It means that the MXS output is controlled by choosing the input pulse, and we can provide
a X-ray photon when needed at precisely known times.
To reduce the cost and size, currently, we are developing a new MXS using a carbon nanotube instead of
LED and CEM.

Fig. 2. MXS with CEM developed by our group.

Fig. 3. Left : Output X-ray ﬂux as a function of the widthof input pulse for the LED (the frequency of the input
pulse is ﬁxed at 10 kHz). Right : TDC histogram at
ﬁve diﬀerent input pulse widths. The start and stop
signal are the input pulse and the arrival timing of theoutput X-ray, respectively.
Fig. 1. Schematic view of MXS with CEM.
∗1
∗2
∗3

RIKEN Nishina CenterNASA Goddard Space Flight Center
Department of Physics,Tokyo University of Science

References
1) K.Gendreau et al: Proc. of the SPIE, 8443, 84434V(2012)
2) K.Black et al: Proc. of the SPIE, 7732, 77320X (2010)- 178 -

Ⅱ-7. Astrophysics and Astro-Glaciology

RIKEN Accel. Prog. Rep. 48 (2015)

Property of LCP-GEM in pure dimethyl ether at low pressures†

†

∗1
∗2
∗3
∗4

Condensed from the article in JINST 9 C01002 (2014)
RIKEN Nishina Center
Department of Physics, Tokyo University of Science
NASA/GSFC
Department of Mechanical Engineering, Kogakuin University- 179 -

Ratio

(this experiment / Magboltz)

We developed a photoelectric X-ray polarimeter
onboard X-ray advanced concepts testbed (XACT)
sounding rocket, the ﬁrst dedicated NASA rocket mission for high sensitivity observation of cosmic X-ray
polarization.1,2) The polarimeter uses a time projection chamber technique to obtain the distribution ofphotoelectron emissions from which the polarizationof the incident X-rays can be measured. A key deviceof the polarimeter is a 100-µm-thick gas electron multiplier (GEM) foil with a copper-clad liquid crystal polymer insulator (LCP-GEM),3,4) which ampliﬁes the signal that keeps the track image of photoelectrons. The
required gain of the LCP-GEM for the polarimeter is
3,000 without discharge. Fine photoelectron track images are essential for a highly sensitive measurement of
X-ray polarization. By extending the track length using a low-pressure gas, high-resolution photoelectron
track images can be obtained. On the other hand,
the low-pressure gas decreases the X-ray detection efﬁciency of the polarimeter. We anticipate that the
optimum gas pressure of pure dimethyl ether (DME)
is 50−150 Torr by considering the trade-oﬀ between
the detected count rate and the modulation factor.1)
However, LCP-GEMs have never been operated below
190 Torr in DME gas. Under such low gas pressures,
discharge is one of the most signiﬁcant risks to the successful operation of GEMs. To explore this unknown
regime, we performed a systematic investigation of thegain properties of a 100-µm-thick LCP-GEM in DME
at low pressures for the ﬁrst time.
We developed a prototype gas-chamber detector,
which possesses the same geometry as the ﬂight modelof XACT. By irradiating the chamber with 6.4 keV
X-rays, we obtained the spectrum from the readout
pad and ﬁtted it with a Gaussian model. An energy
resolution of approximately 20% at the FWHM wasachieved. The highest gain under stable operation at
190 Torr was 2 × 104 at dVGEM = 560 V, while thatat 20 Torr was approximately 300 at dVGEM = 470 V.
Above 50 Torr, the highest gain exceeded 3000, whichmeets our requirements for the XACT polarimeter.
The gain curves could be reproduced by exponentialfunctions; however, a change of slope with pressure
was observed. In addition, we determined the real
GEM gain derived from the sum of charge amounts
induced in the readout pad and GEM anode using the

α / P [ /cm/Torr]

Y. Takeuchi,∗1,∗2 T. Tamagawa,∗1,∗2 T. Kitaguchi,∗1 S. Yamada,∗1 W. Iwakiri,∗1 F. Asami,∗1,∗2
A.Yoshikawa,∗1,∗2 K. Kaneko,∗1,∗2 T. Enoto,∗1,∗3 A. Hayato,∗1 T.Kohmura,∗4 and the GEMS/XACT team

10
Magboltz
190 Torr
110 Torr
70 Torr
50 Torr
40 Torr
30 Torr
20 Torrline fitted by exponencial function

1
1.2
1
0.8
0.6
0

500

1000

1500

EGEM / P [V/cm/Torr]

2000

2500

3000

Fig. 1. Top: Comparison between the measured α and theα simulated by Magboltz7) with 1σ errorbars.Bottom:
Ratio of α obtained in this experiment to that obtainedwith Magboltz calculation.

same data set. The real gain represents the ampliﬁcation degree of electron drifting in the GEM hole,while the eﬀective gain is the real gain multiplied by
the ampliﬁed electron collection eﬃciency of the readout pad.5) The real gain is approximately twice theeﬀective one because the charge amount of the GEM
anode is almost the same as that of the readout pad.6)
The highest gain at 190 Torr is 4 × 104 , while thatat 20 Torr is around 600. These real gain curves also
show deviation from an exponential function.
To comprehensively characterize the gain variations
with diﬀerent gas pressures and GEM voltages, we derived the ﬁrst Townsend coeﬃcient, α. Fig. 1 shows
the observed α as a function of EGEM /P superposedwith the results of Magboltz calculations.7) EGEM is
the electric ﬁeld applied to the GEM. The data points
can be roughly reproduced by an exponential function,although they show deviation from it in the higher
EGEM /P range. This is because the DME ions gain
suﬃcient kinetic energy from such a strong electric ﬁeld
to ionize the DME gas and emit additional electrons
that are ampliﬁed in the GEM hole. The measured α
values were approximately 80% of ones derived from
Magboltz calculations, which suggests that the length
over which the number of electrons were ampliﬁed in
the GEM hole was diﬀerent from the GEM thickness
but close to 80 µm.
References
1) K. Gendreau et al.: Proc. SPIE, 8443 84434V-1 (2012)2) J.K. Black et al.: NIM, A581 755 (2007)
3) T. Tamagawa et al.: NIM, A560 418 (2006)
4) T. Tamagawa et al.: NIM, A608 390 (2009)5) J. Benlloch et al.: NIM, A419 410 (1998)
6) Y. Takeuchi et al.: JINST, 7 C03042 (2012)7) S.F. Biagi: NIM, A421 234 (1999)

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-7. Astrophysics and Astro-Glaciology

Measurement of the electron drift velocity in DME gas
M. Kubota,∗1,∗2 T. Kitaguchi,∗1 A. Hayato,∗1 W. Iwakiri,∗1 T. Enoto,∗1,∗3 K. Nishida,∗1,∗2 Y. Takeuchi,∗1,∗2
A. Yoshikawa,∗1,∗2 and T. Tamagawa∗1

∗1
∗2
∗3

is 0.242 cm/µs, is 196.3 V/cm by interpolating the observed values. Reproducibility of the results should bechecked in further experiments.
Chamber

Be window

DME 190 Torr

Drift plane
Slit

X-ray

Ed

MXS

Preamp

GEM
Ei =1500 V/cm
Readout strip

TDC
Pulse gen.

Fig. 1. Experimental setup to measure the electron drift
velocity in DME gas.

Time diﬀerence (µsec)

We have developed a photoelectric tracking type gas
X-ray polarimeter using a time projection chamber
technique for cosmic X-ray polarimetry.1) We selectdimethyl ether (DME) as target gas of the polarimeterbecause the electron drift velocity in DME is relatively
slow. The polarimeter chamber, filled with DME gas
under a pressure of 190 Torr, consists of three components: drift plane, gas electron multiplier (GEM),
and readout strips. When an X-ray interacts with a
DME gas atom, a photoelectron is ejected in a direction according to a cosine probability distributionaligned with the electric field vector of the incident Xray. Secondary electrons produced by photoelectron
ionization are drawn by the electric field to the GEM,
amplified by a factor ～3000 with the strong electricfield in the GEM hole, and then collected by readout
strips. The 2-d image of the photoelectron track created by the readout strip position and timing enables
measurement of the polarization degree of incident Xrays. In order to square the pixel size of the 2-d image, the electron drift velocity is optimized to be 0.242
cm/µs, which is derived from a strip pitch of 121 µm
over a sampling rate of 50 ns. Thus, we accurately
measure the electron drift velocity in DME gas undera pressure of 190 Torr as a function of applied electric
filed.
Figure 1 shows a schematic view of experimental
setup. We generated X-rays with a modulated X-ray
source (MXS), whose X-ray radiation can be controlled
by a switching LED2) with a pulse generator. Generated X-rays were collimated and directed parallel to
the GEM foil. The drift distance of electrons to the
GEM foil changed by moving it up and down the chamber using the Sigma Koki Z-stage. We measured thetime interval between the leading edge of the pulse,which turned on the LED, and a discriminator signal
created by charges induced on the GEM cathode. The
drift velocity can be determined by dividing the X-ray
beam position difference by the time interval difference. Figure 2 shows time interval as a function ofstage position. The drift velocity was calculated by
the slope of this plot.
The observed drift velocities, vobs , at various electric field are listed in Table 1. The drift velocities are
determined with an accuracy of < 0.5%, and are consistent with the Magboltz prediction3) , vsim , under the
DME gas condition of 190 Torr and 25◦ C. We determined that the electric field, where the drift velocity

10
9

6

15

8
7

cm

V/

/cm

5V

21

6
5
4
3
2

5.2

5.4

5.6

5.8

6

6.2

6.4

6.6

Relative drift distance (mm)Fig. 2. Time difference as a function of stage position. The
drift velocity is calculated by the slope of this plot.
Table 1. Comparison of simulated drift velocity and measured velocity.
Ed(V cm−1 )
156
176
186
196
205
215

vobs
(cm µs−1 )0.1918(6)0.2161(10)0.2291(8)0.2405(8)0.2525(9)0.2650(8)vsim(cm µs−1 )0.1916(2)0.2158(2)0.2285(3)0.2411(3)0.2532(3)0.2651(3)References
1) K. Black et al: NIMPA, 581, 755 (2007).
2) Keith Gendreau et al: Proc. of the SPIE, 8443, 84434V(2012).
3) S.F. Biagi: Nucl. Instr. and Meth. A 283, 716 (1989).

RIKEN Nishina Center
Department of Physics, Tokyo University of Science
NASA/GSFC- 180 -

Ⅱ-7. Astrophysics and Astro-Glaciology

RIKEN Accel. Prog. Rep. 48 (2015)

Measures for Micro Meteoroids and Orbital Debris in Cooler Driver
Harnesses of the Soft X-ray Spectrometer onboard ASTRO-H
H. Noda∗1 and T. Tamagawa∗1 on behalf of the SXS teamThe Soft X-ray Spectrometer (SXS)1) onboard the
6th Japanese X-ray satellite ASTRO-H2) covers an
0.3–12 keV band with an unprecedentedly high energy resolution of 7 eV (the target value is 4 eV). The
performance of X-ray spectroscopy is achieved using
micro-calorimeter technology at a low temperature of∼ 50mK, which is maintained through the following
cooling chain. Stirling coolers, called Shield Coolers(SCs) and Pre-Coolers (PCs), decrease the temperature from ∼ 290K to ∼ 20K, and subsequently, a JouleThomson cooler (JT) further decreases the temperature to ∼ 4.5K. Then, the temperature is cooled downto ∼ 1.2K with superﬂuid helium and/or an Adiabatic
Demagnetization Refrigerator (ADR), and ﬁnally thetemperature is reduced to ∼ 50mK using two-stage
ADRs at the front end of the chain.
Electric power derived by a satellite bus is supplied
to SCs, PCs, and the JT via cooler drivers named
SC Driver (SCD), PC Driver (PCD), and JT Driver(JTD), respectively1) . The cryo-coolers and cooler
drivers are connected by multiple harnesses, and thenumbers of particularly important harnesses for driving the cryo-coolers are 4 in SCD, 4 in PCD, and 2
in JTD (10 in total). Because a part of the dewar
surface is placed in front of a window of the satellite
panel (Fig. 12) ), the harnesses are partly exposed tospace, and hence, Micro Meteoroids and Orbital Debris(MMODs) of various sizes can collide with the harnesses. If one of the important harnesses is destroyed
because of collision with an MMOD, the cooling chain
fails to work as required, signiﬁcantly degrading the

SXS performance. Thus, the design needs to satisfy
the requirement that the number of MMODs passing
through an important harness per year must be lower
than 0.1. In the present document, we roughly estimate the probabilities with 1-digit accuracy in caseswith and without a Kevlar measure3) , and we determine whether the requirement can be satisﬁed.
The probability that a harness is penetrated by an
MMOD can be estimated by multiplying an area exposed to space, a solid angle against space, and ﬂux
of MMODs. In each harness, the part exposed tospace commonly has a length of ∼ 2 m and a solid
angle of ∼ 0.5π against space, while the sum of widthsof important parts driving the cryo-coolers is ∼ 1–3
mm (for simplicity, we hereafter employ a width of
3 mm for all the harnesses). According to a debris
ﬂux model, MASTER20094) , developed by the European Space Agency (ESA), the MMOD ﬂux drasticallychanges with their sizes. Because the critical MMOD
size is determined as the smallest diameter penetrating a harness, the ﬂux depends on the toughness of theharnesses. According to the JAXA space debris protection manual3) , the critical MMOD size for a commonlyused harness cable is ∼ 0.2 mm, while that for the samecable covered by a 1-layer Kevlar ﬁber is calculated tobe ∼ 0.4 mm. Therefore, the MMOD ﬂuxes can be
determined to be ∼ 10 and ∼ 1 collisions/m2 /year forharnesses without and with the 1-layer Kevlar coverage, respectively.
We calculated the probabilities that one of the important harnesses is penetrated per year. The casewithout Kevlar coverage has the probability
0.5π
10 pieces × 2 m × 0.003 m ×× 10 collisions/m2 /year
2π≈ 0.2 collisions/year,
while the probability for the case with the 1-layer
Kevlar ﬁber decreases to
0.5π
× 1 collisions/m2 /year
10 pieces × 2 m × 0.003 m ×
2π≈ 0.02 collisions/year.
Thus, we successfully conﬁrmed that the design withthe 1-layer Kevlar ﬁber coverage is eﬀective to satisfy
the requirement, and we have employed the measures
for all the SCD, PCD, and JTD important harnesses.

Fig. 1. Flight model of the ASTRO-H satellite body in a vibration test, including the engineering model of the SXS
dewar2) on the inside. The red dotted square shows awindow at the satellite panel, through which the harnesses are exposed to the space and MMODs can enter.
∗1

RIKEN Nishina Center- 181 -

References
1) K. Mitsuda et al. SPIE 7732, 773211 (2010)2) T. Takahashi et al. SPIE, 9144, 914425 (2014)
3) JAXA space debris protection manual, 2009, JERG-2144-HB001
4) ESA MASTER: http://www.master-model.de8. Accelerator

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RIKEN Accel. Prog. Rep. 48 (2015)

Emittance measurements for RIKEN 28 GHZ SC-ECRIS†
Y. Higurashi,*1 J. Ohnishi,*1 K. Ozeki,*1 and T. Nakagawa*1
During the last several years, we have been working on
increasing the intensity of highly charged uranium (U) ion
beams and we have produced intense beams (≈180 eµA for
U35+ and ≈230 eµA for U33+) using the sputtering method 1).
It is obvious that the emittance of highly charged U ion
beams should be sufficiently smaller than the acceptance of
the accelerators of the RIKEN RIBF for safe acceleration.
Therefore, to minimize the extent of emittance for intense
beams of U ions, we intensively studied the effect of the ion
source parameters on the emittance. If the magnetic field
distribution affects the ion dynamics and the trajectory of
the extracted beams, 2) it may also affect the emittance ofhighly charged heavy ions.
Emittance was measured using an emittance monitor,
which consists of a movable thin slit and wires (beamprofile monitor).
The root mean square (rms) emittance is defined as(1)
In these equations, the averages of the phase-spacecoordinates of position (x, y) and divergence (x’, y’) are
weighted by the beam intensity 3).
To investigate the magnetic field distribution effect, wemeasured the emittance for various magnetic field
distributions with 18- and 28-GHz microwaves.
The magnitude of maximum mirror magnetic fieldstrength at the beam extraction side (Bext) was changed from
≈1.8 T to ≈1.4 T, while keeping the other magnetic fieldstrengths constant (Binjti≈3.1 T, Bmin≈0.65 T and Br≈1.8 T)
for investigating the Bext effect with 28-GHz microwaves.
The RF power and the extraction voltage were ≈1.5 kW and
22 kV, respectively. Figure 1 shows the normalized rms
y-emittance as a function of Bext. The emittance drasticallychanged from ≈0.07 to ≈0.17 π mm mrad as Bext decreased
from ≈1.4 T to ≈1.8 T. The beam intensity also depended on
Bext. It changed from ≈60 eµA to 40 eµA as Bext decreased
from ≈1.8 T to ≈1.4 T. In this figure, open circles denote theaveraged emittance for various drain currents (2.5-4.5 mA),
which is proportional to the extraction current. The error
bars (emittance spread ≈0.015 π mm mrad) are the standard
deviations.
The magnitude of Binj was changed from ≈1.5 T to 3.1 T,
while keeping the other magnetic field strengths constant(Bext ≈1.45 T, and Bmin ≈0.65 T, Br ≈1.8 T) for investigating
the Binj effect. Figure 2 shows the results for rms
y-emittance. The emittance increased from ≈0.09 to ≈0.17 π
mm mrad as Binj increased.
†

Condensed from the proceedingw of ECRIS 2014, 21st International
Workshop on ECR Ion Sources August, 24–28,Nizhny Novgorod, Russia＊1
RIKEN Nishina Center

Fig. 1. Normalized rms y-emittance as a function of Bext.

Fig. 2. Normalized rms y-emittance as a function of Binj with
28-GHz microwaves, for Bext ≈1.45 T.

We measured the emittance of U35+ ions for various ion
source conditions. The extent of emittance was independentof the drain current and extraction electrode position. On
the other hand, it strongly depended on the magnetic field
distributions. The study of the Binj effect may yield somenovel information, implying that the emittance of U35+ ionsis not influenced by the extraction conditions, but rather by
the ion dynamics in the plasma modified by Binj. On theother hand, for less heavy ions such as Xe, Kr, and O ions,preliminary experimental results did not show any strong
effects of the magnetic field distributions as for U35+ ion
beams. The magnetic field distribution may affect only
highly charged very heavy ions. Additional research is
required to understand these phenomena.
References

1) Y. Higurashi et al.: Rev. Sci. Instrum. 85 02A953 (2014).
2) P. Spaedtke et al.: Proc of 18th Int. Workshop on ECR ion
sources, Chicago, USA, 2008, http://www.jacow.org, P. 213.
3 ) I. G. Brown: The Physics and Technology of Ion
Sources. (Wiley, New York, 1989, p. 94).

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-8. Accelerator

Supply of 70Zn beam from 18-GHz ECRIS using the micro-oven
K. Ozeki,＊1 Y. Higurashi,＊1 and T. Nakagawa＊1
In the 18-GHz electron cyclotron resonance ion source(ECRIS)1), we have achieved the practical use of the
micro-oven to supply high-intensity and stable 48Ca beams
for a long term. 2-4) In the process of the operational tests,
we found that the temperature of our oven could be
increased up to about 1000○C without damaging the oven.
At that temperature, the vapor pressure of ZnO is expected
to reach a level high enough to extract the Zn beam withadequate intensity. Therefore, we conducted the supply testof Zn beam using the micro-oven.
In contrast to the Ca beam, in which the Al powder ismixed to the CaO powder to reduce CaO, only the powderof ZnO was placed in the crucible because the vapor
pressure of ZnO is sufficiently high. The hot liner5), whichplays an important role in reducing the material
consumption rate when supplying the 48Ca beam, is not
used when supplying the 70Zn beam because even if theoven current is increased, the beam intensity hits a peak at
an inadequate level when installing the hot liner into the
ECRIS.
When increasing the oven current gradually, the water
evaporated first. By increasing the oven current, theproduction of the Zn beam was observed at the oven current
lower than that at which the Ca beam was produced. This
production seems to be due to the metallic Zn existingslightly in ZnO. The production of the Zn beam at this ovencurrent was terminated after a short time. By further
increasing the oven current, the production of the Zn beam
was observed again at the oven current higher than that at
which the Ca beam was produced.
The 70Zn15+ beam produced by the micro-oven was firstsupplied for the experiment at the RIBF, from May to June
2014. The beam intensity at the exit of ECRIS and the ovencurrent are shown in Fig. 1. As an example, the power
applied to the oven for the oven current of 2.45 A (May 16
to May 19) is estimated to be 39 W. The RF power fed to
the ECRIS was 550 W. During the experiment, the sudden
increases in pressure in the ECRIS, followed by either theincrease in beam intensity or runaway of the ECRIS,
occurred several times. These phenomena seem to be due tothe grain size of the ZnO (in this experiment, the material
was prepared by chipping sintered ZnO rod. The grain size
was up to about 1 mm in diameter). Assuming that a grain
had a metallic Zn core and a ZnO shell, the inner pressureof the grain increases. The shell becomes thinner with theevaporation of ZnO and cracks at some point to cause asudden increase in pressure in the ECRIS. This instability
problem seems to be prevented by chipping the grains as
fine as possible.

＊1

Because there was a break period (“CGS failure” in Fig.
1), the material was replaced just to be safe. The statuses ofbeam supply before and after the break are summarized inTable 1. The consumption rate all through the experiment
was 0.14 mg/h.
Table 1. Status of beam supply.
Before After
Beam intensity [electric A]
30
33
Amount of ZnO placed in the crucible [mg] 1007
835
Amount of ZnO consumed [mg]5922Consumption rate of ZnO [mg/h]
0.16
0.10
The vapor pressures among Ca, Zn, and ZnO are in thefollowing order: Zn > Ca > ZnO. In order to evaporate ZnO,
an oven temperature higher than that for Ca is required. But
after being decomposed into Zn and O by the plasma, avapor pressure higher than that of Ca is obtained.
Sufficiently low consumption rate without the hot liner
seems to stem from the above relation of vapor pressures.

Fig. 1. Long-term supply of the 70Zn beam for theexperiment at the RIBF. The beam intensity for 70Zn15+(gray) and the oven current (black) are shown.
References

1) T. Nakagawa et al.: Nucl. Instrum. Methods B 226, 392 (2004).
2) K. Ozeki et al.: RIKEN Accel. Prog. Rep. 46, 128 (2013).
3) K. Ozeki et al.: Rev. Sci. Instrum. 85, 02A924 (2014).
4) K. Ozeki et al.: Rev. Sci. Instrum. (to be published).
5) A. Efremov et al.: Rev. Sci. Instrum. 69, 662 (1998).

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RIKEN Accel. Prog. Rep. 48 (2015)

Current status of the RIKEN 18-GHz superconducting ECR ion
sourceT. Nagatomo,∗1 K. Kobayashi,∗2 M. Nishimura,∗2 T. Kageyama,∗1 Y. Kotaka,∗2,∗3 Y. Ohshiro,∗3
V. Tzoganis,∗1,∗4 O. Kamigaito,∗1 and T. Nakagawa∗1
The RIKEN 18-GHz superconducting electron cyclotron resonance ion source (18-GHz SC-ECRIS) provides comparatively light ions to the RIKEN AVF cyclotron1) , which is used as an injector at the RI Beam
Factory (RIBF) as well as for investigations in lowenergy nuclear physics, material sciences, and biological irradiations and RI productions for commercial use.
The 18-GHz SC-ECRIS was designed as a liquid-Hefree system, and similar ion sources were constructedat the end of the 1990s2) . The SC-ECRIS consistsof four superconducting solenoid coils and a permanent Nd-B-Fe hexapole magnet, which generate the socalled minimum-B magnetic mirror geometry. A highpower 18-GHz microwave (∼ 500 W) is used to heatup the electrons in the plasma, so that highly charged
heavy ions can be produced. The superconducting
solenoid coils whose ﬁlaments are made of Nb-Ti alloy are cooled with a 4.2-K Giﬀord-McMahon (GM)refrigerator (0.7 W). In addition, the high-Tc superconducting current leads are cooled with another 20-K
GM (4 W).
Last summer, these coils could not be cooled below
100 K after 21 days of cooling. This happened justafter the annual maintenance of the cryostat systems,
and so, we suspected that the thermal insulation surrounding the solenoid coils might be degraded. That is
why the whole set of the solenoid coils and the vacuum
insulation including the cryostat systems have been
replaced with another set that was used in the past
and was held in reserve. The replacement was carriedout last October, following which the super-conducting
coils could successfully be cooled to 4 K.
The permanent hexapole magnet had a length of 350
mm and an outer diameter of 199 mm. The hexapole
magnet has been replaced with a larger one with anouter diameter of 210 mm so that the radial magnetic
ﬁeld increases from 1.0 T to 1.1 T at the magnet poleface to enhance the plasma conﬁnement for the 18-GHz
operation.
The klystron power ampliﬁer (KPA), which was used
to generate the high-power 18-GHz microwave, also
showed degradation over time. Moreover, the output
power was unstable, which directly led to ﬂuctuationof the extracted beam intensity. That is why we haveintroduced a traveling-wave tube ampliﬁer (TWTA)
instead of the KPA even though the maximum output
∗1
∗2
∗3
∗4

RIKEN Nishina Center
SHI Accelerator Service Ltd.
CNS, The University of Tokyo
Department of physics, University of Liverpool- 185 -

power of the TWTA (750 W) is half of that of the KPA.
As a result of this replacement, new remote control
functions and additional interlocks to protect the ion
source were appended to the existing remote operating
system.
The beam emittance extracted from the 18-GHz SCECRIS does not seem to be well matched with the acceptance of the low energy beam transport (LEBT)
system of the AVF cyclotron. Transverse emittances
are crucial parameters and can be optimized by matching the emittance with the acceptance of the LEBT.
Moreover, decoupling any inter-plane correlation in thetransverse 4D emittance is important to increase thebeam brightness3) . At present, no device to measure
the emittance is installed in the beam line following
the 18-GHz SC-ECRIS. Because of a spatial limitation to install a new device, we have started to develop a compact emittance meter based on the pepperpot method4) . The prototype emittance meter was
installed behind the analyzing magnet. As the ﬁrst
step, we have obtained an image of beam spots of
6.52-keV p+ (∼ 80 eµA) as shown in Fig. 1. The
transverse r.m.s emittances were measured to be about
40 mm mrad. Further developments and investigations are in progress to establish the emittance meter
which can be applied for diagnostics of the low-energy
highly charged heavy-ion beam extracted from ECR
ion sources.

Beam

Horizontal

Fig. 1. An image of beam spots obtained using the prototype pepper-pot emittance meter.

References
1) S. Kohara et al.: Nucl. Instrum. and Meth. A,
526 (2004), p. 230.
2) T. Kurita et al.: Rev. Sci. Instrum. 71 (2000), p. 909
3) C. Xiao et al.: Phys. Rev. STAB, 16 (2013), 044201
4) H.R. Kremers et al.: Rev. Sci. Instrum. 84 (2013),
025117

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-8. Accelerator

Acceleration test of 235U
K. Ozeki,*1 Y. Higurashi,*1 T. Nagatomo,*1 and O. Kamigaito*1
Transmutation of long-lived fission products included in
the radioactive waste into short-lived or stable nuclei is oneof the fundamental issues for future nuclear energy. In orderto design a reasonable process for transmutation,
fundamental data on nuclear reactions, such as the neutron
capture cross section over a wide energy range, are crucial.
Acceleration of such radioactive nuclei would help in
obtaining the fundamental data through nuclear reaction
studies using radioactive beams.
The biggest obstacle in the acceleration of such nuclei istheir high radioactivity, which limits the available amountof radioactive material in an ion source. The solution to thisproblem is to mix a very small amount (several tenths of
micrograms) with the usual ion source materials, andaccelerate them by pilot-beam acceleration. In this machine
study, the feasibility of pilot-beam acceleration wasinvestigated for 235U, which is included in natural uranium(natural abundance of 0.7204%), using 238U as the pilot
beam. As shown in Fig. 1, the 235U isotope is present insuch minute quantities that it is impossible to be identified
by the analyzing system of the RIKEN 28-GHz
Superconducting Electron Cyclotron Resonance Ion Source(28-GHz SC-ECRIS).1)

peak speculated to be due to 235U35+ was identified by the
profile monitor installed at downstream of SL-U10(PF-U10b). The extraction voltage of the 28-GHz
SC-ECRIS and acceleration voltage of the RIKEN Linear
Accelerator 2 (RILAC2)3) were multiplied by 235/238 to
extract and accelerate the particles comprising the peak. The
235 35+
U beam was successfully observed downstream of the
RILAC2 (B61).
Since the 235U35+ beam with an intensity of several
electric nA was observed with the main differential probe(MDP) moved to the injection region, we tried to accelerate
235 35+
U by tuning only the phase of RF and the excitation
current of the main coils of the RRC, while keeping thesignal of the MDP as constant as possible. However,
because of our insufficient tuning skill, it was difficult to go
beyond the radii of 2 m; hence, we gave up this acceleration
procedure.
Therefore, the SL-U10 was fully opened. A beam
intensity of about 100 electric nA was observed with the
MDP, which was enough to obtain the signal from the phaseprobe (PP). By tuning the isochronism, we achieved
acceleration of the 235U35+ beam in the RRC. The turnpattern of the circulating 235U35+ beam measured by the
MDP is shown in Fig. 2. The extraction efficiency was
about 75%.

Fig. 2. Turn pattern of the circulating 235U35+ beam in the
RRC.

Fig. 1. Charge distribution of the uranium ions with a slit
aperture of ±0.1 mm. 235U ions are expected to appear at
the position indicated by the red arrow, but they cannot
be identified.
As the first step of the machine study, the 238U35+ beam,
which was used as a pilot beam, was extracted from the
RIKEN Ring Cyclotron (RRC).2) Next, the aperture of theslit installed at the exit of the 28-GHz SC-ECRIS (SL-U10)
was decreased, and the excitation current of the analyzing
magnet of the 28-GHz SC-ECRIS was swept. Then, a small*1

Besides our insufficient operational ability, the difficultyin the acceleration test mentioned above stemmed from thefundamental fact that isochronism cannot be achieved bychanging only the main coil current. The magnetic fieldcalculation revealed that several trim-coil currents should
be changed over a wide range to accommodate the massdifference of more than 1% of the uranium ions. In our
subsequent study, we plan to accelerate 234U35+ by using
235 35+
U as the pilot beam, based on an accurate magnetic
field calculation.
References

1) T. Nakagawa et al.: Rev. Sci. Instrum. 81, 02A320 (2010).
2) H. Kamitsubo: Cyclotrons’86, 17 (1986).
3) O. Kamigaito et al.: Proc. of PASJ2-LAM31, 502 (2006).

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RIKEN Accel. Prog. Rep. 48 (2015)

Modification of septum electrode for RRC-EDC
K. Yamada,∗1 S. Ishikawa,∗2 T. Nakamura,∗2 M. Nishida,∗2 and H. Okuno∗1
Electric deﬂection channel (EDC) is an importantdevice to extract the circling ion beam in a cyclotron
by using high-static electric ﬁeld up to 10 MV/m. The
circling beam and the extracting beam in the cyclotron
are separated by a septum electrode, which is a thinground electrode of the EDC and only the extracting
beam is aﬀected by the electric ﬁeld and deﬂected. Because major beam loss in the cyclotron occurs on the
septum electrode, the heat load restricts the maximum
beam intensity accelerated by the cyclotron. Especially for the uranium beam acceleration at the RIBF,
turn separation of the circling beam in the RIKEN ring
cyclotron (RRC) is about 7 mm due to the low acceleration voltage and the short stopping range of ions ina material causes melting of the septum electrode, as
happened in ﬁscal year 2012. Therefore, a new septum
electrode for the RRC-EDC was introduced in order toimprove the heat-load durability of the beam loss.
We fabricated the septum electrode with a V-cut
entrance as shown in Fig. 1. The septum electrode
was made of oxygen-free copper and divided into twopieces, the entrance side and the remainder, to facilitate the replacement of the damaged entrance side.
Thickness of the beam-pass area on the septum electrode was 0.8 mm for the entrance side, 1.6 mm forthe central part, and 5 mm for the exit. The coolingwater pipes between the two pieces were connected by
a VCR1) tube ﬁtting. Ten points of E-type thermocouple devices were mounted on the septum electrodefor thermal interlock.
Figure 2 shows the results of the 3D heat transfer calculation for the original and the new septum electrode assuming turbulent forced convective
heat transfer by cooling water. The range of bothplots is from 0 ◦ C to 1100 ◦ C. For the original
septum electrode, which is a simple ﬂat plate, themaximum temperature was about 850 ◦ C assuming

V-cut

4.0 mm(height)×0.8 mm(thickness)×0.05 mm(range)
uniform distribution of 300 W heat load at the entrance, and assuming the heat transfer coeﬃcient of
20000 W/(m2 ·K) on the inside of cooling water pipe.
On the other hand, the maximum temperature was reduced to 670 ◦ C for the new septum electrode assuming 500 W uniform heat load for the same dimensions
and same heat transfer coeﬃcient. For both cases, theperipheral temperature was set to 25 ◦ C. The original
septum electrode was replaced by the new one, andthe old driving motors for the RRC-EDC were alsochanged to new stepping motors. The modiﬁed RRCEDC was used for the machine time from the winter of2013, including the RIBF experiment. No failure wasfound on the new septum electrode with about 4.5 kWof 238 U35+ beam and 1.6 kW of 48 Ca beam.
In order to extend the capability for further intensity growth, we have started to develop a mass-lessseptum electrode by arranging numerous thin tungsten ribbons. A test piece of a 50-µm-thick tungsten ribbon was irradiated by varying the intensity of
238 35+U
beam with an energy of 10.7 MeV/u provided
by the RRC in November 2014 to investigate the melting boundary. The tungsten ribbon melted at an intensity of about 50µA. The result will be comparedwith the heat transfer calculation and the prototype
septum electrode will be fabricated.

Thermocouples

Beam
Fig. 2. Results of the 3D heat transfer calculation aroundthe beam entrance side for the original (upper panel)and the new (lower panel) septum electrode.

Cooling water pipe
Fig. 1. New septum electrode with a V-cut entrance.
∗1∗2

References
1) Product of Swagelok Co.

RIKEN Nishina Center
SHI Accelerator Service Ltd.

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Ⅱ-8. Accelerator

Construction of new amplifiers for RILAC†
K. Suda,∗1 E. Ikezawa,∗1 N. Sakamoto,∗1 K. Yamada∗1 Y. Touch,∗2 T. Ohki,∗3 K. Oyamada,∗3 K. Kaneko,∗3
M. Tamura,∗3 H. Yamauchi,∗3 A. Yusa,∗3 and O. Kamigaito∗1
RILAC consists of six variable frequency cavities(tanks) constructed in 19781) . The first amplifier wasconstructed in 1977 as a prototype for tank #1. Fiveother amplifiers were constructed the next year. The#5 and #6 amplifiers were upgraded in 1999 for experiments super heavy element synthesis. Three finalstage plate DC power supply (plate PS) were upgradedat the same time; one PS supplies DC voltage to two
amplifiers.
In recent years, several issues related to amplifiers#1 to #4 were encountered, such as water leaks fromcooling pipes and damages to the socket for the tetrodecaused by insufficient contact. The contact between
the socket and tetrode is shallow and a careful alignment is necessary. In particular, the design of the #1
amplifier was the oldest, so it became difficult to maintain it. Therefore, the amplifier #1 was upgraded in
FY 2013 along with #2, because the plate PS was common for #1 and #2, and its control system had to be
upgraded at the same time.
The new amplifier, as well as those for #5 and#6 are based on a tetrode RS2042SK coupled with a
RS2012CJ from THALES/SIEMENS with a grounded
grid circuit, that were originally designed for RRC2) .
The maximum RF signal of 0.01 W (10 dBm, 18 to
40 MHz) is amplified by pre-, driver- and, final-stage
amplifiers up to 150 kW. In 14 years of operation of the
RILAC #5 and #6, we have experienced several parasitic modes, which might damage the tank and/or theamplifier itself. One is caused by a coupled oscillation
between the 99-MHz G1-G2 resonance of RS2042SK
and the output circuit including a feeder line to thetank. The other example is the 7th harmonic mode
observed in RILAC #5. In order to avoid such parasitic modes, a 50 kW dummy load was installed at aplate stub.
In a factory, matching conditions for input and output circuits of driver- and final-stage amplifiers were
measured and/or tuned. (1) The gain of the input
circuit for a driver amplifier called as “All Pass Network” was measured and confirmed to be sufficient. (2)An input circuit for the final amplifier was tuned bya vacuum variable capacitor (INCAP) and a movable
shorting stub located at a cathode input. The following was performed after installation in an accelerator
hall: (3) An output impedance of the final amplifier
was matched by changing a plate stub and a capacitor(OUTCAP). Details are described in Ref.3) .
∗1
∗2
∗3

RIKEN Nishina Center
Sumitomo Heavy Industries
SHI Accelerator Service Ltd.

- 188 -

Fig. 1. Result of dummy load tests for two amplifiers (#1,#2). Voltages of plate (Ep ), currents of plate (Ip ),screen (Ig2 ) and control grids (Ig1 ), and the increase intemperatures of the cooling water (∆T ) for the driverand final amplifiers are shown.

The old amplifiers were removed in December 2013,
and the new ones were installed in January 2014.
Dummy load and power tests were performed in February 2014. In dummy load tests, a water-cooled 250 kW
dummy load was connected to the output of the amplifier. It succeeded in obtaining an output power of
150 kW at three frequencies (Fig. 1). Then, load tests
were performed at 36.5 MHz. The required acceleration voltages of RILAC #1 and #2 were successfully obtained. Beam service using the new amplifiers
started on schedule on March 10th, 2014. A few problems occurred during operations. One was the leakageof cooling water from a rf power feeder of #14) . Thiswas partly due to heating at the output flange of theamplifier. The parameters of the amplifier were tuned,so that the temperature of the flange decreased. The
other problem was that an automatic tuning control
system stopped its sequence abnormally. This happened in both amplifiers in some cases since May 2014.
The PLC program was corrected in October 2014.
References
1) M. Odera et al., Nucl. Instrum. and Methods, 227, 187(1984).
2) T. Fujisawa et al., Sci. Papers I.P.C.R. 80 (1985).
3) K. Suda et al., Proc. of LINAC14, MOPP12, 339 (2015).
4) E. Ikezawa et al., In this report.

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RIKEN Accel. Prog. Rep. 48 (2015)

Magnet system for a new beam transport linefrom IRC to E5 experimental room
K. Kumagai,*1 N. Fukunishi,*1 and S. Fukuzawa＊2
We constructed a new beam transport line to provide
high-energy beams accelerated by the IRC to the E5experimental room in the Nishina building for biologicalexperiments. The magnet system of the beam transport line
was designed on the basis of the following factors: (1) For
economic reasons, magnet power supplies were notproduced, and existing power supplies were used byswitching. (2) The new transport beam line was connectedto the second half of the existing RRC to the E5 beam line.
(3) As a part of the new beam transport line uses theexisting IRC bypass beam line in the opposite direction, thebeam line optics was designed to reduce the number ofmagnets that require polarity change. (4) In order to be able
to switch a large number of magnets or magnet polarity
with a simple procedure, nineteen switches assembled in
two control panels were laid out in one place.
Figure 1 shows the layout of the new beam transport
line. The magnet power supplies were prepared in thefollowing way:
•The DAKR magnet (1500 A-26 V) used the old DC
power supply previously used for the fRC-MIC2. As thispower supply could operate at various currents and voltages,
it was installed in front of the RRC room so that it could be
utilized as a spare of the several power supplies for the
RRC when it was not used for the DAKR.
•The polarity switches were added to the power supplies
for DMR3, DMR4, and DMR5 dipole magnets on thebypass beam line.
•Three dipole magnets, DMR6, DMR7, and DMR8, wereconnected in series and excited by the old fRC main power
supply removed in 2012 for the enhancement of the fRC.1)
The auxiliary power supplies built into the power supply
were used for fine adjustment of the magnetic field ofindividual magnets. The transistor banks in the auxiliary

power supplies had to be modified to match the output
power of each magnet.
•As the maximum current (300 A) of the existing power
supply for the DMD5 dipole magnet immediately before
entering the E5 room was insufficient, the 420 A-150 V
power supply for RIPS-Q11 was used by switching.
•Fourteen new quadrupole magnets used the power
supplies for quadrupole magnets on the IRC-SRC transportline by switching. The cables from the power supplies were
wired to the magnets on the new beam transport line and the
IRC-SRC transport line through load switching panels.
•The first steering magnet right after the IRC named
STR00 used the power supply for STK01 on the IRC-SRC
transport line by switching.
•All magnets on the new beam line except STR00 usedthe dedicated 10 A-60 V power supplies controlled by aLinux-based PLC named F3RP61.
Boring for the wiring through experimental vaults andrelocation of the power supplies were completed in 2013.
Wiring and an operation test of the power supplies were
performed in the summer of 2014. In December 2014, thepolarity check and excitation test for the all magnets were
performed. In January 2015, we planned to carry out thecommissioning of the new transport line using the
160MeV/u 40Ar beam.
At present, the switching of the dipole and quadrupole
magnets and their polarity is performed manually. In
FY2015, we plan to operate switching automatically using
buttons.
References
1) K.Kumagai et al.: RIKEN Accel. Prog. Rep. 46, 132(2012).

Fig. 1. Layout of the new beam transport line from IRC to E5.
＊1

RIKEN Nishina Center＊2

SHI Accelerator Service Ltd.

- 189 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-8. Accelerator

Improved-flatness beryllium disk stripper for uranium acceleration
at RIKEN RIBF
H. Hasebe,＊1 H. Okuno,＊1 H. Kuboki,＊1 H. Imao,＊1 N. Fukunishi,＊1 M. Kase,＊1 and O. Kamigaito＊1
We have successfully provided a stable uranium beamduring long-term operation in November 2012 (totally 1.18
× 1018 particles in 37 days) using a rotating beryllium disk
stripper with a thickness of 0.1 mm as the second stripper.
The number of irradiating particles and disk conditions are
summarized in Table 1 along with those of other disks
described below. This first used Be disk is denoted as Disk
1 in the Table. However, emittance growth due to thenonflatness of the disk exceeded the accepted levels for
subsequent cyclotrons (IRC, SRC)1).
To realize flatter disks, we prepared a Be disk subjected
to diamond polishing (Disk 2) in March 20132). Also, disk
thickness was reduced from 0.1 mm to 0.085 mm, which
was suited for the IRC injection energy. Therefore,transmission efficiencies of the IRC and SRC were
improved. The Be disk was still usable even after the totally
9.29 × 1017 U-particle irradiation during the 30-day beamtime operation3).
Disk 2 was used again for the U beam time in March
2014. The lifetime of this disk ended and was determined tobe additional 21 days (Fig. 1: Right). The total number of U
beam particles was 1.68 × 1018 during 51 days (including 30
days in 2013) as written in Table 1. Many cracks wereobserved along the beam irradiation traces.
The Be disk was replaced with a new one (Disk 3), which
was identical to Disk 2 (0.085-mm-thick, diamondpolished), for the remaining beam time. Irradiation with anadditional 8.83 × 1017 U particles was carried out in 17 days.
Beam transmission efficiency was improved, but since thethermal load to the disk was increased from 90 W to 230 W
because of the increased beam intensity, the disk was
greatly deformed. The difference in the deformation isshown in Fig. 1 (Right: Disk 2, Left: Disk 3).

Table 1. Summary of four Be disk used.

Be Disk 1
Not polish
0.1-mm thick
Be Disk 2
Diamond polish
0.085-mm thick
Be Disk 3
Diamond polish
0.085-mm thick
Be Disk 4
Diamond polish
0.085-mm thick
φ110mmSpecial processing

Irradiation 　current
Total beam particle
4 - 5 eµA18

1.18x10

Days

State
Many cracks

37

Still usable
Slight beam fluctuation

4 - 12 eµA
18

1.68x1051(30+21)

Distortion and Many cracks
Not usable
Slight beam fluctuation

12 eµA17

8.83x10

Distortion, Slightly cracked

17

Still usable
No beam fluctuation

8 eµA

Slightly Distorted

17

9x10

No crack

20

Still usable
No beam fluctuation

In October 2014, we introduced the Be disk with a
special design2) (Disk 4) to reduce the thermal deformation.
Due to this improvement, this Be disk survived after the U
beam time with approximately 9 × 1017 U-particle
irradiation·in 20 days. Main changes were as follows: 1)
The outer diameter of the disk was 110 mm (from 120 mm),2) 12 areas with cuts existed around the disk circumference,3) the disk holder was made of copper (from aluminum)with an outer diameter of 65 mm, and 4) 12 holes with
2-mm diameter existed around the holder.	
  Beamavailability was further improved by the suppression of thebeam fluctuation. The conditions of U beam irradiation arelisted in Table 1 (Disk4). This Be disk is still usable andexhibits no problem. Figure 2 shows the special-design Be
disk: (left) new and (right) after usage.

(a)(b)
Fig. 2. (a) New specially designed Be disk and (b) after
irradiation. Deformation was moderated.
Fig. 1. Polished Be disks after irradiation (Right: Disk 2,
Left: Disk 3).

*1 RIKEN Nishina Center

References
1)
2)
3)

- 190 -

H. Hasebe et al., RIKEN Accel. Prog. Rep. 46, 133 (2013).
PASCAL CO., LTD.
URL: http://www.pascal-co-ltd.co.jp/home.html
H. Hasebe et al., RIKEN Accel. Prog. Rep. 47, 144 (2014).

Ⅱ-8. Accelerator

RIKEN Accel. Prog. Rep. 48 (2015)

Thinning eﬀect of gas strippers for high-intensity very heavy ion
beams
H. Imao,∗1 H. Okuno,∗1 H. Kuboki,∗1 O. Kamigaito,∗1 H. Hasebe,∗1 R. Koyama,∗1∗2 and M. Kase∗1
Intensity upgrade of very heavy ions beams, such as
U and Xe beams, is one of the main concerns at the
RIKEN Radioactive Isotope Beam Factory (RIBF). In
the acceleration of the very heavy ion beams, the possible output intensities have been limited mainly by
the lifetime problem of the carbon foil strippers. In
previous years, the realization of gas strippers was animportant breakthrough for the intensity upgrade ofvery heavy ion beams1,2) . In order to achieve higher intensities of very heavy ion beams, we must understandthe application limit of the gas stripper. Density reduction of the gas along the trajectories of the beams,
caused by the heat load (thinning eﬀect), is a factor determines the application limit of the gas stripper. To
validate the thinning eﬀect at the present intensities,
we measured the velocities of the uranium beams after
the stripper as a function of the beam intensities.
In the measurements, 238 U35+ beams up to 1particle µA at 10.8 MeV/u were injected into the helium gas stripper placed after the RIKEN ring cyclotron. The arrival time of the beams before and after the stripper were measured using the phase probe.
The measured time diﬀerence (∝ gas density and gas
temperature) depends on the output beam current, asshown in Fig. 1, where the beam current is changed
with the duty of a beam chopper. For the higher
beam current, the velocities of the output beams arehigher because of gas density reduction due to higher
heat deposition. The saturation of the time diﬀerence depends on the chopping frequency f , as shownin Fig. 1. The beam structure for the chopping frequency f is also shown in Fig. 1. A simpliﬁed differential equation for the temperature rise T is given
as dT /dt = Q/C − cp ṁ/C, where Q is the heat loadof the beams, C is the heat capacity of helium, cp isthe speciﬁc heat of helium for constant pressure andṁ is the mass ﬂow rate. At Q=0 (timing of beamoﬀ), the temperature reduces with the time constantτ = C/cp ṁ = M/ṁ. The saturation also depends onṁ in the beam region.
Figure 2 shows the dependence of the temperaturerise of the helium gas stripper on the beam current.
The chopping frequency was ﬁxed with 1 kHz in thesemeasurements. Although the temperature rise depends slightly on the beam proﬁle, all measured values were lower than those expected from the calculations (dotted line) with ﬂow-3D (computational ﬂuid
dynamics simulation software). A possible explanation
may be some suppression mechanisms of heat on he-lium due to vacuum ultraviolet light emission from theexcited helium atoms and molecules or energetic delta
electrons emission.
In summary, we clearly observed the thinning effect of helium gas stripper by 1-particle µA uranium
beams. Our results have important implications forlower heating eﬃciencies obtained with some suppression mechanisms.

∗11) H. Imao et al., IPAC 2013, Shanghai (2013).
2) H. Imao et al., IPAC 2014, Dresden (2013).

∗2

RIKEN Nishina Center
SHI Accelerator Service Ltd.

- 191 -

Fig. 1. The dependence of the arrival time diﬀerence on
the beam duty for various chopping frequencies (up)and the beam structure of the chopped beam (down).

Fig. 2. Dependence of the temperature rise of helium on
the beam current. Dotted line indicates the calculated
values.

References

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-8. Accelerator

Control and monitoring system of gas strippers
R. Koyama∗1,∗2 and H. Imao∗1
We report on the control and monitoring system ofa gas stripper, a new RIBF charge stripper using agas target. A gas stripper has been developed as analternative to a traditional carbon-foil stripper for increasing the intensity in very heavy ion beams such asuranium or xenon beams at the RIBF. A recirculating
helium gas stripper1) and an air stripper2) are installedat the A02 site after the RRC and at the M04 site after
the fRC (GS-A02 and GS-M04), respectively.
The schematic block diagram of their control andmonitoring system is shown in Fig. 1.

Xe
U

BF1
OT1

BF2
OT2

Heat
exchanger
PT1

PT3

Serial-to-Ethernet converter(NI ENET-232/Na�onal instruments)

TCP/IP

PT2
SerialGauge controller(XGS-600/Agilent)

99.6%
recircula�on
Thermocouple module(NI 9213/Na�onal instruments)

Oriﬁce temp. : OT1-8& Pump temp. : PT1-3(K-type Thermocouple)

CompactDAQ chassis(NI cDAQ-9171,9172/Na�onal instruments)

Solid-state relay(NI 9485/Na�onal instruments)

USB

TCP/IP(Network
shared variables) Windows PC@Local(LabVIEW program)
PCI

Windows PC@Console(LabVIEW program)
DeviceNet interface(NI PCI-8532/Na�onal instruments)
DeviceNet

USB/Serial
Gauge controller(M-603GC/Cannon Anelva)
Air compressor
Pressure gauges:(M-360CP,M-350PG/Cannon Anelva)

GS-M04

124

OT6

BF5
OT7 Air Target OT8

Xe52+

124

: Mechanicalbooster pump
: Turbomolecularpump: Rotary pump

Fig. 1. Schematic block diagram of control and monitoring
system for gas strippers.

We developed a user-friendly GUI program using the
LabVIEW for the system, which includes the following:

∗1
∗2

0.10
6500
0.05
6450
0.00

Beam �ming
0

5

He gas target
pressure
10

15
20Time [min]

-0.05
25

-0.10
30

0
-2
-4
-6
-8
-10
-12
-14

Fig. 2. Correlation among target pressure of GS-A02, beamtiming, and beam intensity observed by the phaseprobe.

Beam interlock system
ChannelaccessLabVIEW EPICS
EPICS
Buﬄe current: BF1-5
Client I/O Server
control system(beam loss monitor)

Mass ﬂow controller(FCST1500FD/Fcon)

0.15

6400

2

0.20

Beam intensity

6550

6350

TCP/IP

Xe40+ BF4
OT5

238 64+

MBP array

Serial

6600

40+

Xe
U

GS-A02BF3OT3 He Target OT4Foreline
trap

Control unit
(RVC 300/Pfeiﬀer Vacuum)

MyDAQ2server(Data record)

124

Helium gas target pressure [Pa]20+238 35+Pressure gauges:(CDG-500/Agilent,
MG-2/Cannon Anelva)

He gas

PP-D15 beam �ming dri� [ns]124

The developed system allows us to remotely optimize the target pressure of gas strippers with the assistance of the online beam monitoring system5) . Figure 2 shows the correlation among the target pressureof GS-A02, beam timing, and beam intensity nondestructively observed by a phase probe (PP).
PP-G01 beam intensity varia�on [%]Gas regula�ng valve(EVR 116 -> RME 005 A/Pfeiﬀer Vacuum)OT8 and mechanical booster pumps PT1–PT3• Signal output to the beam interlock system in response to the monitoring value via the NI CompactDAQ• Data recording to the MyDAQ2 system3)• Remote control of the pressure and/or ﬂow rateof the target gas• Monitoring of the pressure of each diﬀerentiallypumped section• Monitoring of buﬄe current BF1–BF5 (beam loss
monitor) via the EPICS control system3,4)• Monitoring of the temperature of oriﬁces OT1–
RIKEN Nishina Center
SHI Accelerator Service Ltd.

- 192 -In this case, the beam timing at PP-D15 (31 m
downstream of the GS-A02) gradually varied owing to
the energy loss reduction in the GS-A02 as its target pressure decreased6) , resulting in a ∼10% decrease
in beam intensity at PP-G01 (5 m downstream of
the SRC). The beam intensity was recovered by twice
ﬁne controlling the target pressure by observing thebeam monitoring system, as indicated by the arrows
in Fig. 2. The pressure should be regulated with ±1%
accuracy by the control unit, however, it got out-ofcontrol at the end of the machine time, so we speculate that its accuracy was reduced owing to irradiation
damage to the regulating valve EVR 116 near the GSA02 in the RRC vault. EVR 116 has been replacedwith radiation-proof RME 005 A.
References
1) H. Imao et al.: Proc. of IPAC2013, Shanghai, China,
May 2013, THPWO038, p.3851 (2013).
2) H. Imao et al.: Proc. of IPAC2014, Dresden, Germany,
Jun. 2014, THPME067, p.3388 (2014).
3) M. Komiyama et al.: Proc. of ICALEPCS2011, Grenoble, France, Oct. 2011, MOPKN005, p.90 (2011).
4) R. Koyama et al.: RIKEN APR 46, 135 (2013).
5) R. Koyama et al.: Nucl. Instr. Meth. A 729, (2013) 788.
6) H. Imao et al.: in this proceedings.

Ⅱ-8. Accelerator

RIKEN Accel. Prog. Rep. 48 (2015)

Beam Energy and Longitudinal Beam Profile Measurement Systemat the RIBF†
T. Watanabe,∗1 M. Fujimaki,∗1 N. Fukunishi,∗1 H. Imao,∗1 O. Kamigaito,∗1 M. Kase,∗1 M. Komiyama,∗1
N. Sakamoto,∗1 K. Suda,∗1 M. Wakasugi,∗1 and K. Yamada∗1

Upstream C20

Downstream C22

Fig. 1. Longitudinal profiles the 19 F9+ beam measured at
C20 (upstream) and C22 (downstream) in the AVF cyclotron beam transport line as displayed on the graphical user interface.
†∗1

Condensed from the proceedings in 5th International Particle Accelerator Conference (IPAC’14)
RIKEN Nishina Center- 193 -

C20 : Fitted by Gaussian function
C22 : Fitted by Gaussian function

12000

Center TC22 :6.95 ns

10000

TDC Yield (counts)

Monitors with plastic scintillators as sensors (scintillation monitors) were fabricated to measure the energy and longitudinal proﬁles of heavy-ion beams at
the RIKEN RI beam factory (RIBF). Six pairs of two
scintillation monitors installed in the transport lines
were used to measure the particle time-of-ﬂight (TOF)
between the paired monitors to determine the acceleration energy of the heavy-ion beams. The energy ofthe beam can be calculated from the measured TOF.
In addition, ﬁve scintillation monitors were installed
to measure the longitudinal proﬁles of the heavy-ion
beams. Longitudinal beam proﬁles were obtained byusing a time-to-digital converter (TDC), which digitizes the detected signals from the scintillator and the
RF clock signal. Recently, to help users operate thesystem more easily, a new embedded processor witha higher-performance CPU has been introduced, anda new user interface has been constructed using the
LabVIEW program.
For data acquisition and control of the scintillation
monitors, we developed a ccompactPCI system thatuses a Windows-based PC1) . Signals from the detectors are ampliﬁed and converted to logic pulses by
a constant-fraction discriminator. The TDC digitizes
this pulse along with the RF clock and stores the events
into the memory of the TDC. The TDC (TC890) has
two memory banks based on a so-called ping-pongmemory architecture that enables data readout while
the module continues to acquire events. When a bankis ready to be read, an interrupt is generated, andthe readout starts in the direct memory access mode.

Center TC20 :13.00 ns

C22

C20

8000
6000

(1-V):
7.23 deg.

4000(1-V):
6.67 deg.

2000
0
0

5

10

15

20

Time (ns)Fig. 2. Gaussian functions fit to the rightmost beam profiles at C20 and C22 in Fig. 1.

The programs for the data acquisition, control, and forshowing results are written in LabVIEW (Windows7).
The PCs are connected to a laptop in the main control room located 100 m from the Riken ring cyclotron(RRC) hall via Ethernet and remote desktop connection. The EPICS system controls insertion of the monitor into the beam line or its retraction from the beamline and it monitors these statuses.
We measured the energy of a 19 F9+ beam accelerated by the AVF cyclotron by using the TOF method.
The 19 F7+ beam was used to produce element 105,
262
Db from a target of 248 Cm2) . Because the sequential double pulse resolution was 15 ns, the 19 F9+ beam
was attenuated to be under 1 M s−1 using beam attenuators. The longitudinal proﬁle of the 19 F9+ beam wasmeasured at C20 (upstream) and C22 (downstream) in
the AVF cyclotron beam transport line were displayedon the graphical user interface as shown in Fig. 1. The
rightmost longitudinal proﬁles obtained at C20 andC22 in Fig. 1 are expanded and plotted in Fig. 2. By
ﬁtting the proﬁles in Fig. 2 with Gaussian functions, we
determined the center times TC20 and TC22 of the proﬁles and the longitudinal phase widths (1-σ), as shownin Fig. 2. The beam kinetic energy (TT OF ) obtainedby measuring the TOF was 6.81 MeV/u. In addition,
the beam kinetic energy (TBρ ) can be determined by
the magnetic ﬁeld of the bending magnet that bends
the 19 F9+ beam because the ﬁeld was already known
as a function of the exciting current. In this measurement, the hysteresis eﬀect was not taken into account.
The kinematic energy TBρ was determined to be 6.80
MeV/u. These energies are in good agreement, with adiﬀerence between TT OF and TBρ of 0.1%.
References
1) T. Watanabe et al.: RIKEN Accel. Rep. 43, 135 (2010).
2) M. Murakami et al.: RIKEN Accel. Rep. 47, 265 (2014).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-8. Accelerator

Maintenance and development of the RIBF control system
M. Komiyama,＊1 A. Uchiyama,＊1 M. Fujimaki,＊1 K. Kumagai,＊1
N. Fukunishi,＊1 M. Hamanaka,＊2 and T. Nakamura＊2
We report on the maintenance work and development of
the RIBF control system, which include addressing aproblem experienced with a beam interlock system (BIS),1)
upgrades for two types of control boards used for magnet
power supplies and an extension of the control system toinstall a new beam transport line.
The RIBF control system consists of two parts according
to the development of RIBF. One of them is used for the old
facility, once called the RIKEN Accelerator Research
Facility (RARF), which started its operation in 1986. The
other is the new facility that started its operation in 2006. A
BIS was developed to protect the hardware of the RIBF
accelerator complex from unallowable beam losses forhigh-power heavy ion beams. The BIS is composed mainlyof Melsec PLCs2) that process many interlock signals, suchas failure signals sent from rf systems used in our
cyclotrons, magnet power supplies, and vacuum gate valves
in beam transport lines, within 1ms. At the RIBF facility,
there are two sets of BIS working for the old facility and the
new facility as well as the control system. In 2014, we
experienced for the first time a serious problem in which
several interlock conditions were changed without any
command inputs. After careful investigations, the cause ofthis malfunction, a failure of the CPU module used in the
BIS, was rectified by replacing the existing CPU modulewith a spare one. Because the hardware used in the BIS isaging and the trigger of this malfunction is unclear, we
prepared spare CPU modules in preparation for similar
troubles in the future; this would be effective in reducing
downtimes during RIBF operation.
The second topic is upgrades for the Network-I/O (NIO)
system. The NIO is a commercially available control
system manufactured by Hitachi Zosen Corporation. It is
widely used to control many magnet power supplies used in
the new facility and a part of the old facility. The NIO
system consists of several types of controllers. The NIO-S
board is directly attached to a magnet power supply andcontrols it according to a signal from an upper-level control
system. About 500 NIO-S boards are used in RIBF. The
NIO-C board works as a master board of NIO-S boards andis designed to run in VME computing machines. The
NIO-C and the NIO-S are connected by an optical cablethrough a branch board. The existing NIO system has beenworking stably but production of the present NIO-S board
was terminated because some parts are unavailable today.
Therefore, we developed a successor of the existing NIO-S
board in 2013 and this year we ran its performance tests.
This successor was designed to be compatible with the＊1＊2

RIKEN Nishina Center
SHI Accelerator Service Ltd.

existing NIO-S board but the performance tests revealed
that some types of magnet power supplies cannot be
controlled by the successor because the widths of some
output pulses produced by the successor are slightly
different from those given by the existing one. Currently,
finding a solution to stably control these magnet power
supplies is under consideration.
On the other hand, production of the NIO-C has also
been completed for the same reason as in the case of NIO-S.
Hence, we should also develop a successor board of thepresent NIO-C. Its R&D started in 2014. The specifications
required for the new board are essentially the same as forthe existing one, but we decided to design the new board to
run in a control system constructed by PLC modules insteadof the VME computing environment currently used, inorder to achieve cost reduction and functional scalability.
We started the design of its prototype in 2014, which isscheduled to be delivered in March 2015. Softwaredevelopments required for the successor board arescheduled in 2015, where some new features will be added.
The third topic is extension of the control system to covera new beam transport line now under construction, aiming
at increasing the available beam energies in the existing
beam irradiation port dedicated to biological experiments.
The new beam line transports a beam extracted from theintermediate stage ring cyclotron (IRC) to the E5experimental vault (hereafter, IRC-E5 BL). The control
system for the IRC-E5 BL is constructed as a naturalextension of the existing control system of the RIBF
accelerator complex by adding the new components used in
the IRC-E5 BL to the existing control system because no
new types of components are installed in the IRC-E5 BL.
Magnet power supplies are controlled by the NIO systemand F3RP61,3) which is a Linux-based PLC-CPU module
manufactured by Yokogawa Electric Corporation, on which
EPICS programs can be executed. Vacuum systems andbeam diagnostic devices such as beam profile monitors arecontrolled using in-house controllers’ Network Device
Interface Module (N-DIM4)) as well as the other beamtransport lines of the RIBF accelerator complex. Regarding
the beam interlock signals of the IRC-E5 BL, we
incorporate them into BIS. Beam commissioning isscheduled in January 2015.
References

1) M. Kobayashi-Komiyama et al.: RIKEN Accel. Prog. Rep. 39,
239 (2006)
2)http://www.mitsubishielectric.co.jp/fa/products/cnt/plcq/items/3) http://www.yokogawa.co.jp/rtos/Products/rtos-prdcpu9-ja.htm
4) M. Fujimaki et al.: RIKEN Accel. Prog. Rep. 37, 279 (2004)- 194 -

Ⅱ-8. Accelerator

RIKEN Accel. Prog. Rep. 48 (2015)

Development of new operational log system for RIBF operation∗1∗1 system for∗1RIBF operation
Development ofA.new
operationallog
Uchiyama,
M. Komiyama,
and N. Fukunishi

∗1
∗1
∗1
A. isUchiyama,
Komiyama,Whenand theN. Fukunishi
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one of the M.
electric
monitored operation status, such as thelog systems for recording and viewing the acceleraDAC value of a magnet power supply, is changed, thetorTheoperation
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system)database.
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one
of
the
features,themonitorlog systems for recording and viewing the acceleraDAC value of a magnet power supply, is changed,prothe
KEK
wasutilizedastheoperationallog
systemforthegram
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tor operation time and contents of an operated destatusacquires
is stored
operational
intogatethe4)
because(IOCs)RIKEN
RIBF
control system.
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fully
the requirements
on a satisfy
Web browser(Firefox). ofInusers.
the near future, we
Therefore, we developed a new operational log system
will update the system for improving the usability tofor RIBF control system.
fully satisfy the requirements of users.

Fig. 1. Outline of the new operational log system.
1. Outlineof thenewsystem,
operational
system.
InFig.
additionto theZlog
thelogPostgreSQLbased database, which is one of the major relational
databases,
is adopted
for recording
logsPostgreSQLin the new
In addition
to the Zlog
system, theoperationallog system.
order
to major
ensure relational
compatibased database,which is In
oneof thebilitywith Zlog,
the new
log system
databases,
is adopted
for operational
recording logs
in the usesnewthesame databasetableIn configurationas compatiin Zlog.
operationallog system.
order to ensureThecharttheofnew
newoperational
operationalloglogsystemsystemisbilitysystemwith Zlog,
uses
shown
in
Fig.1.
The
RIBF
controlsystemconsists
the same database table configuration as in Zlog.
ofa distributed
controlsystemconstructedusing theThesystem chartof new
operationallog systemisExperimental
Physics
andIndustrial
Control
Systemshown in Fig.1. The RIBF control system consists
3)
Therefore,featureto store using
the data(EPICS).
of a distributed
control thesystemconstructed
theinto the databaseis developedon the Control
basis of caMonExperimental
Physics
and Industrial
System3) is an event driven program using EPICS
itor, which
Therefore, the feature to store the data
(EPICS).
channel(CA)
protocol. on the basis of caMoninto the accessdatabaseis developed
itor, which is an event driven program using EPICS∗1 RIKEN Nishina Centerchannel access (CA) protocol.
∗1

RIKEN Nishina Center

Fig. 2. User interface showing operational log for magnet
power supply.
Fig. 2. User interface showing operational log for magnet
power supply.

References

1) K. Yoshii et al.: Proc. ICALEPCS07, (2007), p. 299.
2) http://www.zope.org/
References
3)
Komiyamaal.: RIKEN
Accel. Prog.
Rep.
1) M.
K. Yoshii
et al.:etProc.
ICALEPCS07,(2007),
p. 47.
299.
4)
K.
Evans.
Proc.
ICALEPCS2005,(2005),
PO1.033-6.
2) http://www.zope.org/
5)3) http://getbootstrap.com/
M. Komiyama et al.: RIKEN Accel. Prog. Rep. 47.
4) K. Evans. Proc. ICALEPCS2005, (2005), PO1.033-6.
5) http://getbootstrap.com/- 195 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-8. Accelerator

Commissioning of the Laser Ion Source for RHIC EBIS †M. Okamura＊1,＊2 and T. Kanesue＊1
The electron beam ion Source (EBIS)-based heavy ion
preinjector (RHIC-EBIS) served for RHIC and NASASpace Radiation Laboratory (NSRL) at Brookhaven
National Laboratory (BNL)1). The NSRL is a facility thatsimulates the effect of galactic cosmic radiation (GCR),
which consists of highly energetic heavy ions of various
kinds in space. The RHIC-EBIS is required to provide fastswitching between heavy-ion species for this purpose. A
new laser ion source (LIS), named “LION,” is funded byNASA to expanding the range of ion species available forfast switching. Fast switching can be accomplished byswitching the laser-irradiation position on different target
materials2,3).
LION consists of a high-power pulsed laser, a target
chamber, a 3-m-long plasma drift region with a solenoid
magnet, and an extraction chamber. The ion extraction
voltage may be up to 40 kV. The laser is equipped with two
identical Q-switched Nd:YAG laser oscillators (850 mJ/6 ns
at FWHM, 1062 nm wavelength ). A built-in laser combiner
merges the two laser beams into one laser path to aim at thesame position. The laser is focused on a solid state target
plate. The laser spot on the target is 5 mm in diameter.
Different laser energies in the range 500 ~ 700 mJ is used
depending on the species to achieve singly charged ions. Ina target chamber, several targets are held on a tungsten
target holder, as shown in Fig.1, which is mounted on an
x-y linear stage. The stage allows the laser to irradiate
different positions on different target materials. The
solenoid magnet is used to reduce the diverging angle of the
expanding plasma. The typical magnetic field to be used isonly several Gauss. With this drift length, an ion beam witha pulse width of a few hundred microseconds is achieved.
The commissioning of the beam was started on March 7,2014 with an Fe target. LION was isolated from the EBIS
beam line to prevent RHIC gold run as a precaution. The
platform voltage was set to 12 kV for the first beam test.
The Fe beam extracted from the LION was very close towhat we expected. No breakdown caused by the generated
plasma was observed.
From March 14, the operation mode of EBIS was
adjusted for LION. The transport line and the EBIS
injection timing were investigated to capture ions. The firstbeam extracted from the EBIS was observed on March 16.
On March 26, the first beam at the NSRL target room
was observed with a Ta beam. The beam intensity was
sufficiently high for an NSRL run. Hence, we decided touse the LION for an NSRL run.
†

Condensed from the article in Proceeding of IPAC2014
Collider-Accelerator Department, BNL＊2
RIKEN Nishina Center

Fig. 1 Target holder with Au, C, Fe, and Ta targets from left
to right. Aluminium plates are used to hold the Au target.
The user operation with LION was started from March 27,
and it was very successful. Since then, LION has provided
most of beams for NSRL. This is beyond our initial plan to
use the LIS for several days for commissioning. After all, C,
Si, Ti, Fe, Ta, and Au beams are provided for NSRL userruns.
As predicted, lighter species show less tolerance of thenumber of shots on a single spot to maintain long-term
stability. The target scan step of 0.1 mm / 80 s was used for
C while 0.1 mm / 540 s was used for Fe. These numbers areconservative and should be investigated further for efficientuse of target materials.
The EBIS injection efficiency and the EBIS setting had
been improved continuously. Since June 3, LION with aplatform voltage of 18 kV started to provide Au beams for
RHIC instead of providing beams for NSRL. Until the endof the run, LIS has been working continuously. The target
scan step for the Au target was set at 0.5 mm / 20 s. The
target was 1-mm thick with 25 mm x 25 mm area, and thetarget consumed approximately 50% of its life.
LION was used to provide C, Si, Ti, Fe, Ta, and Au
beams for NSRL and RHIC user operation. This is the first
LIS for low-charge-state ion production to be combinedwith an EBIS-type heavy-ion source for long term user
operation.
References

1) J. Alessi et al., New York, 2011, p. 1966 (2011)2) T. Kanesue et al., Rev. Sci. Instrum., 79, 02B102 (2008)
3) K. Kondo et al., Rev. Sci. Instrum., 81, 02A511 (2010)(2000)＊1- 196 -

Ⅱ-8. Accelerator

RIKEN Accel. Prog. Rep. 48 (2015)

NISHINANISHIA RIBF water-cooling system 2014
T. Maie,*1 K. Kusaka,*1 M. Ohtake,*1 Y. Watanabe,*1 E. Ikezawa,*1 M. Kase,*1
M. Oshima,*2 H. Shiraki,*2 K. Kobayashi,*3 and J. Shibata *3
1. Operation condition
In the fiscal year 2014, the Nishina and RIBF water-coolinginstallation was operated for one hundred and fifty days andfive months, respectively. These operation periods
correspond to the scheduled beam service time of RIBF,
which is five months. In addition, Nishina’s coolinginstallation was used not only for the full RIBF operation
but also for the AVF standalone operation, RILAC + RRC
operations, RILAC2+ RRC operations, and AVF + RRC
operations. During FY2014, there were no severe problems
that caused beam service interruption for the Nishina and
RIBF cooling water system. However, mind problems were
often encountered, these are reported here.
2. Trouble report
Water leakage in the cooling system was a problem,
particularly water leakage from a connection part of theflange portion and coupler in the cooling laying of the pipes.
Another problem is the deterioration due to aging of theslack and the flange packing of the bolt by the vibration of
the coolant pump, electrolytic corrosion, corrosion of thecooling plumbing is important. However, with the coolingfacilities at the Nishina center, a water leakage sensor is
attached to the outside of the accelerator and a beam line,
the point of the cooling plumbing and, regardless of thewhole stop, a member of driving of the accelerator
discovers it easily while driving and comes to be able tocope. Other problems, include issues with the inverter,pressure gauge, and flowmeter, as well as problems with thepacking of the coolant pump and damage of the mechanicalseal; control is the main problem that occurred in 2014. In
some cases, damage to the motor of the cooling tower fan
occurred at snowy weight by the snow. Other factors
affecting cooling facilities other than the above-mentioned
problems include a affected by cooling facilities than a stopof steam and the cold water supplied from rolling blackouts
and the cogeneration in the place. SRC and the Big RIPS
He-refrigerator do not become if they do not always cooloff, and it is necessary for pro-backup, to change the power
supply and coolant beforehand to prevent one from being
affected by a blackout and suspension of the water supply,
which 2-3 times occurs in a year.

3. New establishment, improvement
Even during periodical maintenance, etc. when theaccelerator is stopped, the RIBF cooling facilities havevarious new establishments and show, improved
construction. It is built the cooling facilities for return beamlines as a representative thing by new construction
sequentially from the year before last; As an example of the
improved construction, I improved the cooling plumbing forthe ability for cooling reinforcement pro-IRC and SRC exc.
cooling and cooling reinforcement of SRC-MDC1
sequentially from last year.
4. Summary
I intend to minimize the problems associated with coolingfacilities in future, while aiming for stable cooling facilities
without problems, and suggesting the enforcement ofeffective maintenance, and undertaking premeditateddeterioration measures.
References

1) T. Maie et al.: RIKEN APR .47
2) Y. Watanabe et al.: RIKEN APR .48

RIKEN Nishina Center
Nippon Kucho Service Co., Ltd＊3
SHI Accelerator Service Co., Ltd＊1＊2- 197 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-8. Accelerator

Charge State Selective Ion Beam Acceleration Using the RFQ Linac
Y. Fuwa,∗1,∗2 S. Ikeda,∗1,∗3 T. Kanesue,∗4 M. Okamura,∗4 and Y. Iwashita∗5
In the ﬁeld of Heavy ion beam Inertial Fusion (HIF), one of the promising ion species as the driver beam
is Bi2+ . Considering a scenario based on the RF accelerator, a laser ion source with the Direct Plasma Injection Scheme (DPIS)2) has the advantage to provide
high-intensity heavy ion beams3) . Ion charge states
produced by laser ion sources has distribution4) . With
DPIS, all charge states of ions can be injected into an
RFQ linac. However, in the case of Bi2+ production,
Bi1+ and Bi3+ would also be injected. These unnecessary ions would waste RF power and/or cause unexpected radioactivation. Thus, charge-state-selective
acceleration using the RFQ linac is desired. In thisstudy, a scheme to achieve charge-state-selective ion
beam acceleration is discussed.
In the case of accelerating ions with a charge state q
and a mass number A diﬀerent from the desired particle with q0 and A0 , the condition for stable acceleration
is described as below5) :qq0
cos(ϕs ) =cos(ϕs0 ),
(1)
A
A0
1)

where ϕs is the synchronous phase of a particle withcharge-to-mass ratio q/A, and ϕs0 is that of the desiredparticle. Then, the condition of capture for the case of
A = A0 isq0cos(ϕs0 ) < 1.
0<
(2)
qUsually, the synchronous phase of the the desired particle in the accelerating section of the RFQ linac isapproximately −30◦ . Therefore, by choosing Bi2+ as
the desired particle (q0 = 2), Bi1+ (q = 1) has nostable phase and would not be accelerated, while unwanted Bi3+ will be accelerated. The results of a particle tracking simulation show that more than 30% of
Bi3+ are captured and accelerated by a conventionallydesigned RFQ for Bi2+ .
One of the solutions to accelerate only Bi2+ is thefollowing scheme: 1) The ions are injected into the
RFQ with diﬀerent momentums depending on charge
state q. Using this initial momentum diﬀerence between Bi2+ and Bi3+ , these ions can be pre-bunchedseparately in the longitudinal phase space. 2) The
modulation or acceleration voltage is raised when Bi2+
ions are in the acceleration phase and Bi3+ ions are in
the deceleration phase, and Bi2+ ions would gain energy while Bi3+ ions would be decelerated. 3) Due
∗1
∗2
∗3
∗4
∗5

RIKEN Nishina Center
Graduate School of Science, Kyoto University
Interdisciplinary Graduate School of Science and Engineering
Collider Accelerator Department, Brookhaven National
Laboratory
Institute for Chemical Research, Kyoto University- 198 -

Fig. 1. Applied cell parameters versus cell number.

Fig. 2. Result of longitudinal phase space distribution.
Red: Bi2+ , Blue: Bi3+ . The ordinate axis shows momentum normalized to Bi2+ initial momentum. The
abscissa shows RF phase. (a) Initial distribution, (b)after pre-bunching, (c) after capturing Bi2+ , (d) after
acceleration.

to the energy diﬀerence between Bi2+ and Bi3+ , only
Bi2+ ions would be captured in the RF bucket and be
stably accelerated. To realize this scheme, we variedcell lengths in the bunching section. An example ofthe sequence of the designed cell parameters is shownin Fig. 1. Fig. 2 shows the particle tracking simulation results with the cell parameters shown in Fig. 1.
The capture rate of Bi3+ could be suppressed by up to
3 %.
References
1) R. Burke, Nucl. Instrum. Methods Phys. Res., Sect. A
733 (2014) 158
2) M. Okamura et al., Rev. Sci. Instrum., 79 (2008)
02B314.
3) M. Okamura et al., Nucl. Instrum. Methods Phys. Res.,
Sect. A 733 (2014) 97.
4) K. Kondo et al., Rev. Sci. Instrum. 81, (2010) 02A511.
5) P. N. Ostroumov et al., Phys. Rev. ST Accel. Beams 3,030101 (2000).

Ⅱ-8. Accelerator

RIKEN Accel. Prog. Rep. 48 (2015)

Investigation of the eﬀect of solenoidal magnetic ﬁeld on Fe plasma
ﬂux for application to laser ion source
S. Ikeda,∗1,∗2 M. Okamura,∗3 and K. Horioka∗2

Biased ion probe
Laser
Fe target
o

30 50

ø2 mm
Aperture

72

Grounded mesh

2.5

Current density (mA/cm2)

Laser ablation plasma has been studied as a highly
charged ion source for nuclear physics experiments1)
and as a high ﬂux ion source for heavy ion inertial fusion,2) and it is used as an ion source at Brookhaven
National Laboratory3) . In a typical conﬁguration of
the source, plasma ﬂux at an extractor varies as a function of time. The time-dependent ﬂux results in thechanges in the ion beam current and its optics withina beam pulse. To prevent the changes, we propose to
apply a pulsed magnetic ﬁeld. Enhancement of theﬂux after passing through a static solenoidal magnetic
ﬁeld was observed4) . The enhancement depended on
the magnetic intensity. Therefore, if we apply the fastrising magnetic ﬁeld in accordance with the transient
ﬂux level of the plasma, we will be able to make theﬂux level ﬂat.
To predict the optimal pulsed magnetic ﬁeld, we
ﬁrst investigated the eﬀect of a static magnetic ﬁeldthat was driven by quasi-stationary current during theplasma passing through the coil. We scanned a biased
ion probe detecting plasma ﬂux transversely or normal
to the plasma drifting direction by applying a magnetic
ﬁeld.
Figure 1 is a brief schematic diagram of the experimental setup. A Nd:YAG laser irradiated an iron target with a pulse width of 6 ns and intensity of 4.0×108
W/cm2 . At this irradiation level, the laser mainly produces singly charged ions in the chamber evacuated to
4 × 10−4 Pa. The coil was driven by a pulse circuit.
During the plasma passing through the coil, the decrease in magnetic ﬂux density was less than 10 % andwe can regard the magnetic ﬁeld as almost constantduring the interaction. A 2-mm-diameter aperture and

0G
40 G

2

1.5

1

0.5

0

-40

-30
-20
-10
0
10
20
Transverse distance from center x(mm)30Fig. 2. Transverse flux distribution with and without magnetic fielda metal mesh whose transparency was 90.3 %, weregrounded and placed in front of the probe.
Figure 2 shows the transverse distribution of plasma
ﬂux whose longitudinal velocity vz is 14 mm/µs at 870
mm away from the target. vz was estimated by division of the distance by the time of ﬂight. Horizontal
axis is the distance x from the center axis. Each pointis an average of 3 data. The red squares are data withno magnetic ﬁeld and green ones are in the presence ofmagnetic ﬁeld. The magnetic ﬂux density at the centerof the coil is estimated to be 40 G using a simulation
code(OPERA). When the magnetic ﬁeld was applied,
two peaks and decrease in the ﬂux near the center axis
were observed. The formation of two peaks around x =-15 and 20 mm means that the plasma collected aroundthe radius. The collection indicates that the magnetic
ﬁeld had focusing force that increases nonlinearly withincreasing x. On the other hand, the decrease in theﬂux around the center (x = 0 mm) may mean that themagnetic ﬁeld does not converge the plasma withina certain value of x. The diﬀerence in the magnetic
ﬁeld eﬀect on the plasma with respect to x may result from the shape of the magnetic ﬁeld. We need toinvestigate this diﬀerence in order to increase the ion
ﬂux with minimum emittance growth. The discussionof the enhancement mechanism will help optimize theparameters of pulsed magnetic ﬁeld.
References

Fig. 1. Schematic of experimental setup for transverse scanof ion flux distribution
∗1
∗2
∗3

RIKEN Nishina Center
Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology
Collider Accelerator Department, Brookhaven National
Laboratory- 199 -

1) P. Fournier et al.: Nucl. Instrum. Meth. A, 71, 924(2000).
2) J. W. Kwan, IEEE Trans. Plasma Sci. IEEE Nucl.
Plasma Sci. Soc., 33, 1901 (2005).
3) T. Kanesue et al.: Proceedings of IPAC2014, Dresden,
Germany, p 1890 (2014).
4) J. Wolowski et al.: Laser Part. Beams, 20, 113 (2002).

9. Instrumentation

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Operational status of the superconducting SAMURAI magnet
H. Sato,∗1 K. Kusaka,∗1 M. Ohtake,∗1 and T. Kubo∗1

80
Resistance [Ω]

0.5

70

Resistance [Ω]

60
50

0.3

0.1
4

8

12

16

HTc PL

20

Temperature [K]-20
YOKOGAWA
7651

10
0

50

100

150

+

100
100

LHe
LHe transfer
transferPressure [kPaG],[kPaG],
Pressure
Liquid He
He Level
Level [%][%]
Liquid8080

Temperature [K][K]
Temperature

CC
CC operation
operation

250
250

60
60

200
200
150
150

40
40

GM/JT
GM/JT operation
operation

100
100

20
20

50
50

350
350
300
300

2/13
2/13

2/15
2/15

2/17
2/17

2/19
2/19

2/21
2/21

2/23
2/23

Date
Date

2/25
2/25

2/27
2/27

Lower
Lower coil
coil
LN
LN22 cooling
cooling

100
100
LHe
LHe transfer
transfer

80
80

CC
CC operation
operation

250
250

CC
CC operation
operation

200
200

GM/JT
GM/JT
operation
operation

150
150

100
100

60
60
40
40
20
20

50
50
0
0

0
0

Pressure [kPaG],[kPaG],
Pressure
Liquid He
He Level
Level [%][%]
Liquid

0
0

2/07
2/07

2/09
2/09

2/11
2/11

2/13
2/13

2/15
2/15

2/17
2/17 2/19
2/19

Date
Date

2/21
2/21 2/23
2/23 2/25
2/25 2/27
2/27

0
0

T_coil_vessel_in
T_coil_vessel_in

T_20K_A
T_20K_A

T_80K_B
T_80K_B

T_PL
T_PL

T_coil_vessel_out
T_coil_vessel_out

T_20K_B
T_20K_B

T_shield
T_shield

P_He
P_He

T_coil
T_coil

T_80K_A
T_80K_A

T_shield_port
T_shield_port

Liquid_He
Liquid_He

200

coil

V
YOKOGAWA
MV1000250

300

Temperature [K]Fig. 1. Correlation between resistance and temperature of
the superconducting coil. The upper and lower insets
are an enlarged graph of below 20 K and a schematic
diagram of the measurement of the resistance, respectively.

Figure 2 shows the trend of the temperature, pressure in the helium vessels, and liquid helium level. It
took one month to complete the cooling-down operation, and 7,125 L of liquid nitrogen (LN2 ) and 3,145 L
of liquid helium (LHe) were used in total.
The graph of the lower coil exposes our inexperience of the cooling of the magnet. This led to imperfect removal of LN2 , resulting in the dissipation of
LHe. However, we gathered technical know-how during the cooling-down procedure of the lower coil. (1)The cooling-down speed during LN2 transfer should be
∗1

300
300

Fig. 2. Trend graph of the upper and lower coil during
the cooling. T means the temperature of each part1) .
P He means the pressure in the helium vessel. Liquid He means the LHe level (100%≈240 L). The notation “CC” means 20 K, 80 K, PL cryocoolers, and“GM/JT” the GM/JT cryocoolers1) .

0.2

30

0

LN
LN22 cooling
cooling

0.4

0
0

40

Upper
Upper coil
coil

350
350

Temperature [K][K]
Temperature

The first cooling down of the superconducting
SAMURAI magnet1) was done by TOSHIBA in April
2011, and we had maintained the operation of the cryogenic systems of the magnet. However, the magnet
was warmed up in September 2013 in order to savethe operation time of the cryocoolers2) . Therefore, themagnet was cooled down again in February 2014 forthe coming experiments. The cooling operation was
performed by ourselves in order to save the cost.
Firstly, the pumping of the vacuum vessels of thecryostats was started. We waited for 8 days until thevacuum level reached 2 × 10−5 Torr. Secondly, thecooling-down procedure was started. The temperatureof each point in the cryostat, excluding the coil, wasmonitored by thermometers. The temperature of thecoil was monitored by measuring the resistance of thecoil using the correlation shown in Fig. 1. Although
the temperature below 9 K cannot be measured withthis method, there is no problem for the cooling-down
operation because the temperature of the coil vessel isalso monitored.

RIKEN Nishina Center- 201 -

around 10 K/h. (2) Special care must be taken whenchecking the residual LN2 . (3) The pressure of gaseous
He should be 0.03–0.05 MPa when pushing and removing LN2 . (4) The coil vessels should be evacuated tobe −99 kPaG before replacing the residual gaseous N2
in the coil vessels with gaseous He. It takes about
30 min. (5) The position of the transfer tube in theservice port is very important in order to transfer LHe
without loss. (6) The pressure of gaseous He shouldbe 0.03–0.05 MPa, and that of the LHe Dewar shouldbe 0.028–0.034 MPa (4–5 psi) when transferring LHe.
These were successfully applied to the cooling of theupper coil. In our next operation, the period of thecooling down will be shortened, and the amount of LN2and LHe will be reduced with the experience gained inthis study.
References
1) H. Sato et al.: IEEE Trans. Appl. Supercond. 23,4500308 (2013).
2) H. Sato et al.: RIKEN Accl. Prog. Rep. 47, 173 (2014).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Preparation status of the (p, 2p) fission experiment with the
SAMURAI spectrometer
S. Reichert,∗1,∗2 M. Sako,∗2 M. Sasano,∗2 D. Mücher,∗1,∗2 A. Andreyev,∗3 T. Aumann,∗4 H. Baba,∗2
M. Böhmer,∗1 M. Dozono,∗5 N. Fukuda,∗2 R. Gernhäuser,∗1 W. F. Henning,∗6 K. Hirose,∗3
N. Inabe,∗2 D. Kameda,∗2 N. Kobayashi,∗2 T. Kobayashi,∗7 Y. Kondo,∗8 T. Kubo,∗2 Y. Kubota,∗2,∗5 R. Lang,∗1
L. Maier,∗1 Y. Matsuda,∗9 S. Mitsuoka,∗4 T. Motobayashi,∗2 T. Nakamura,∗8 N. Nakatsuka,∗9 S. Nishimura,∗2
I. Nishinaka,∗3 K. Nishio,∗3 R. Orlandi,∗3 H. Otsu,∗2 V. Panin,∗2 S. Sakaguchi,∗2 H. Sato,∗2 Y. Shimizu,∗2
L. Stuhl,∗2 T. Sumikama,∗2 H. Suzuki,∗2 H. Takeda,∗2 Y. Togano,∗2 T. Uesaka,∗2 J. Yasuda,∗2 K. Yoneda,∗2
and J. Zenihiro∗2
The experiment NP-1306-Samurai14 is the first attempt at determining fission barrier heights for unstable nuclei like 212 Bi or 213 Po1) . For this the missing mass spectroscopy of the two protons from the(p, 2p) reaction in inverse kinematics provides a suitable method of determining the threshold for the fission barrier height unambiguously and directly. We
report on the development status of the experimental setup for measuring the (p, 2p) reaction using theheaviest projectiles.
The goal for the resolution power of the setup is toachieve an energy resolution of σ=1 MeV for the reconstructed excitation energy. The systematic uncertainty
in the reconstructed missing energy should be less than
0.1 MeV. To realize this goal we need to measure theopening angle and energies of two emitted protons withresolutions of σθop < 3 mrad and σEp /Ep < 2%.
The design of the (p, 2p) setup is schematicallyshown in Fig. 1. The setup consists of a vacuum chamber containing a liquid hydrogen target and three layers of single-sided detectors on two arms with respect
to the beam line. The reaction point and the emission angles of emitted protons are determined by thesilicon detectors in connection with the beam trackersof the standard SAMURAI setup, BDC1 and BDC2.
The setup has additional plastic scintillation detectors
at a distance of 1.6 m from the target and outside thevacuum chamber to measure the time of flight (TOF)
of protons in order to determine their kinetic energies.
We prepare two types of silicon detectors with thesame dimensions of 51 × 78 mm; the first type (typeA) is segmented to 768 strips parallel to the short sidewith a 100 µm pitch, whereas the other type (type B)
has 498 strips parallel to the long side with the same
pitch size as type A.
The three layers in one arm are structured in thisway: The closest one to the target is type A, from
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

Technical University Munich
RIKEN Nishina Center
ASRC JAEA
Technical University Darmstadt
Center for Nuclear Studies, University of Tokyo
ANL
Tohoku University
Tokyo Institute of Technology
Kyoto University

which two sets of type A and B detectors are placed
at a center distance of 10 cm to fit the solid angle
coverage. They are mounted in parallel with the beamline as shown by the red lines in Fig. 1, aligning theshorter side of the detector vertically.
The type A and B detectors are used to determine
horizontal and vertical positions of proton tracks, respectively. To meet the requirements on the openyxzTOF detectors
0.5mm
Aluminum 

30
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 

35
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Fig. 1. Target chamber (top view) including three layers of
one-dimensional silicon strip detectors on each side.

ing angle and proton energy measurements, the thicknesses of the detectors must be thin as long as thesignal-to-noise ratio in the charge readout of each strip
allows a clear detection of protons. We aim at using
50 µm silicon detectors for the innermost layer and 100µm ones for the others, to satisfy the requirements. At
the end of 2014, 100 µm ones were ordered. A readout
system based on the highly integrated APV25 chips2)
is currently set up for full system tests.
References
1) D. Muecher et al.: Proposal RIBF NP-PAC-12 Fission
Barrier Studies of Neutron-Rich Nuclei via the (p,2p)
Reaction (2013).
2) J. Lawrence et al.: User Guide Version 2.2 for the
APV25-S1 (2001).

- 202 -

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Slow neutron detector WINDS for (p, n) reaction
in inverse kinematics with SAMURAIJ. Yasuda,∗1 M. Sasano,∗2 R.G.T. Zegers,∗3 H. Baba,∗2 W. Chao ,∗2 M. Dozono,∗2 N. Fukuda,∗2 N. Inabe,∗2
T. Isobe,∗2 G. Jhang,∗2,∗13 D. Kameda,∗2 T. Kubo,∗2 M. Kurata-Nishimura,∗2 E. Milman,∗2 T. Motobayashi,∗2
H. Otsu,∗2 V. Panin, ∗2 W. Powell, ∗2 M. Sako, ∗2 H. Sato,∗2 Y. Shimizu,∗2 L. Stuhl,∗2 H. Suzuki,∗2
T. Suwat, ∗2 H. Takeda,∗2 T. Uesaka,∗2 K. Yoneda,∗2 J. Zenihiro,∗2 T. Kobayashi,∗4 T. Sumikama,∗4 T. Tako,∗4
T. Nakamura,∗5 Y. Kondo,∗5 Y. Togano,∗5 M. Shikata,∗5 J. Tsubota,∗5 K. Yako,∗6 S. Shimoura,∗6
S. Ota,∗6 S. Kawase,∗6 Y. Kubota,∗6 M. Takaki,∗6 S. Michimasa,∗6 K. Kisamori,∗6 C.S. Lee,∗6 H. Tokieda,∗6
M. Kobayashi,∗6 S. Koyama,∗7 N. Kobayashi, ∗7 H. Sakai,∗8 T. Wakasa,∗1 S. Sakaguchi,∗1 A. Krasznahorkay,∗9
T. Murakami, ∗10 N. Nakatsuka, ∗10 M. Kaneko, ∗10 Y. Matsuda, ∗11 D. Mucher, ∗12 S. Reichert, ∗12 D. Bazin,∗3
and J.W. Lee∗13
output in the scintillator was set to be 70 keV protonenergy.
The timing resolution of WINDS bar was estimatedby using prompt γ ray from the liquid hydrogen target.
The timing reference was taken from the plastic scintillators SBT1,2 whose timing resolution is typically 40
ps in FWHM. The observed peak width of the prompt
γ ray was 800 ps in FWHM which is most due to thetiming resolution of WINDS. This timing resolution
corresponds to energy resolution of ∆E/E = 11%.
The neutron-detection eﬃciency depends on the energy of neutrons as well as the threshold on light output. The typical eﬃciency with a threshold of 60
keVee was estimated by using the Monte Calro code of
MCNP4) , and it varied from 40% at 0.6 MeV neutron
to 20% at 4 MeV neutron. The eﬃciency calibration
was performed by locating a neutron source of 252 Cf
at the target position with a NE213 liquid scintillator
whose absolute eﬃciency as well as energy and threshold dependence are well known. The data analysis iscurrently in progress.
Topview

Sideview

WINDS

1200 mm120°
5° step

m
0m

beam

n

Right

n
74°

20°

residual
to SAMURAI 22°
122°

Liq. H

WINDS
Top

ELENS

Left
90

In April 2014, we performed the SAMURAI17 experiment1) at RIKEN RIBF to study Gamow-Tellertransition on 132 Sn by using (p, n) reaction with theWide-angle Inverse-kinematics Neutron Detectors for
SHARAQ (WINDS)2) and the SAMURAI spectrometer.
Figure 1 shows a schematic view of the experimental setup around the target. The secondary beam wastransported to a 10 mm thick liquid hydrogen target,
which was surrounded by the WINDS to detect recoil neutrons. From the measured neutron time-ofﬂight (TOF) and recoil angle, the excitation energy
and center-of-mass scattering angle are determined.
The WINDS consists of 61 plastic scintillators withsizes of 600 × 100 × 30 mm3 . In this experiment 12
scintillators of the ELENS3) with sizes of 1000 × 45 ×
10 mm3 were also installed. The left and right wallswith respect to the beam line covered the angular region from 20 to 122 degrees with 5 degree steps. Top
and bottom walls covered the angular region from 16
to 74 degrees with 3.5 degree steps. Each detector isplaced such that the 30-mm-wide (WINDS) or 10-mmwide (ELENS) plane is oriented to the target direction
and placed at a distance of 900 mm (1200 mm) fromthe target for left and right (top and bottom) walls.
The charge signal from each PMT is digitized by a
CAEN V792 QDC. The timing signal is processed bya leading-edge discriminator (LeCroy 4413) and digitized by CAEN V1190 TDC. In order to maintain a
low threshold of neutron detection, the PMT voltage
is kept to be as high as possible, typically -2700V and-2500V for H7195 and H7415. The threshold for light

beam

14°
residual

Liq. H to SAMURAI

16°

72°
4° step

Botttom∗1

Department of Physics,Kyushu University
RIKEN Nishina Center∗3 NSCL Michigan State University∗4 Department of Physics, Tohoku University∗5 Tokyo Institute of Technology∗6 CNS, University of Tokyo∗7 University of Tokyo∗8 ULIC, RIKEN Nishina Center∗9 MTA, Atomki∗10 Kyoto University∗11 Konan University∗12 Technical University Munich∗13 Department of Physics, Korea University∗2

Fig. 1. A schematic view of the WINDS setup.

References
1) M. Sasano et al.,: in this report.
2) K. Yako et al., RIKEN Accel. Prog. Rep 45, 137 (2012).
3) L. Stuhl et al., Nucl. Instr. Meth. A 736, 1 (2014).
4) Monte Carlo NParticle Transport Code System,
MCNP5-1.60 and MCNPX-2.7.0.

- 203 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Integration of GET system for SπRIT-TPC
T. Isobe,∗1 M. Kurata-Nishimura,∗1 H. Baba,∗1 N. Nakatsuka,∗2 T. Murakami,∗2 W.G. Lynch,∗3 J. Barney,∗3
J. Estee,∗3 S. Tangwancharoen,∗3 G. Jhang,∗4 W. Powell,∗5 and Y. Ayyad,∗6 for the SπRIT Collaboration
A Time Projection Chamber (TPC) has been produced as the main detector of the SAMURAI-SπRIT
project for the study of the nuclear equation of stateusing heavy ion collision experiments1) . As the readout system for the SπRIT-TPC, we have integrated theGeneric Electronics for TPC (GET) system2) , which
was developed mainly by a France and USA collaboration3) . For the integration of GET electronics, development of interfaces in terms of both hardware andsoftware are necessary.
Since the GET system was developed for general usage, the interface of the GET electronics to a TPC
depends on the specifications of each detector, such as
connector types and the signal characteristics of thedetector, and this interface has to be developed foreach project. We call such an interface a ZAP board,which serves as an adapting connector between the
GET electronics and the TPC, as well as providing
protection for the electronics. Thus GET electronics
can be mounted on any TPC by just making the ZAP
board. There are several requirements for designing
the ZAP board. In the case of SπRIT-TPC, the board
was designed to fit in the space on the TPC which is
supposed to be installed in the SAMURAI chamber,to reduce the noise in order to increase the dynamic
range, and to reduce the distortion of gain among thedifferent channels. It is especially important to reducenoise since it strongly affects the electrical treatmentsof a signal. Here the electrical treatments of each signal
are: 1. hit pattern register which is made by the discriminator on each signal after the pre-amplification,
2. internal trigger which is made with the hit patternregister, and 3. zero-suppression of digitized signal.
The quality of the internal trigger strongly depends onnoise level, which is strongly affected by the design of
the ZAP board.
To satisfy our requirements, prototypes of several types of interface boards were made andthe above requirements were checked quantitatively
by using the minimum GET system composed of
CoBo+AsAd+ZAP boards. The AsAd board is forthe amplification and digitization of an analog signal3) . The AsAd must be installed near the TPC inorder to reduce noise. The CoBo board is for handlingthe trigger, controlling the AsAd and managing data3) .

To fit the AsAd board on the SπRIT-TPC within thelimited vertical space of ∼17 cm, a prototype flexible
ZAP made of a thin Cu plate (10 µm) and polymide(12.5 µm) was first made. The noise level of the flexible board, which can be estimated through RMS ofpedestal, is not small. This is most likely due to thelarge capacitor made by the noise shield and signal
line (50∼100 pF/ch). The capacitance of each signal
line can be roughly calculated as a plane parallel plate
capacitor. Ultimately it was decided to use a ZAP
board made of conventional rigid electric board which
has a short signal line and small capacitor on each signal line of 10∼20 pF/ch. The achieved noise level is
4 ADC under the configuration of a dynamic range of
12 bit, 120 fC and a shaping time of 233 nsec. It canbe reduced to be 2∼3 ADC after the subtraction of a
fixed noise pattern (FPN) line which is not connected
to TPC pads. Without this ZAP, the GET electronics
exhibit and average noise level of 3 ADC. This noiselevel is small enough for the SπRIT experiment, and so
the production of ZAP has started and the mounting
of GET electronics on the TPC is ongoing.
The user of the GET system is not only responsible
for the interface to their TPC, but they must also integrate or develop the DAQ. For the SπRIT project,
NARVAL4) is planned to be employed as the DAQ system. By employing NARVAL, large amounts of dataof more than 100 MByte/sec from SπRIT-TPC can behandled. The development of an interface to send datafrom Babirl to NARVAL is being developed so that raw
data from Babirl can be merged with data from GET
system by using NARVAL.
We have performed a test experiment using the GET
system on another TPC with the final ZAP at HIMAC
during November 2014. NARVAL was not used in thistest experiment. The analysis result of the test experiment is reported by G. Jhang in this APR. In the test
experiment, we took benchmark test data of the GET
system. We read out 756 channels with a sampling
rate of 25 MHz and 256 time buckets. A partial readout mode using the hit pattern register was used toincrease the data acquisition rate as much as possible.
A data acquisition rate of 600 Hz and a data rate of
1 GByte/min were achieved, which is sufficient for the
first experiment of SπRIT project.

RIKEN Nishina Center
Department of Physics, Kyoto University
National Superconducting Cyclotron Laboratory, Michigan
State University
Department of Physics, Korea University
Department of Physics, University of Liverpool
Research Center for Nuclear Physics, Osaka University

1) S. Rebecca et al.: Physics Procedia 37, 1799 (2012).
2) T. Isobe et al.: RIKEN Accel. Prog. Rep. 46, 151(2014).
3) E. Pollacco et al.: Physics Procedia 37, 1799 (2012).
4) X. Grave.: Proc. 14th IEEE NPSS RT Conf, 65(2005).

∗1
∗2
∗3
∗4
∗5
∗6

References- 204 -

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Performance evaluation of GET readout electronics for heavy ion
collision experiments at RIBF
G. Jhang,∗1,∗2 T. Isobe,∗2 M. Kurata-Nishimura,∗2 T. Murakami,∗3 M. B. Tsang,∗4 S. Hasegawa,∗5 K. Hosomi,∗5
S. Hwang,∗5 H. Sugimura,∗5 J. Brzychczyk,∗6 B. Hong,∗1 P. Lasko,∗6 J. Lukasik,∗7 W. G. Lynch,∗4
P. Pawlowski,∗7 Z. Sosin,∗6 and S. Tangwancharoen∗4 for the SπRIT Collaboration

∗1
∗2
∗3
∗4

∗5
∗6
∗7

Department of Physics, Korea University
RIKEN Nishina Center
Department of Physics, Kyoto University
National Superconducting Cyclotron Laboratory and Department of physics and Astronomy, Michigan State University
Advanced Science Research Center, Japan Atomic Energy
AgencyJagiellonian University
Institute of Nuclear Physics PAN- 205 -

layer numbers, where one layer means a row of 96 pads
perpendicular to the beam axis and the BRAHMSTPC has 12 layers. To obtain the resolution we selected three successive layers and calculated the diﬀerence between the hit position on the middle layer andthe average position of hits on the ﬁrst and the thirdlayers assuming that the resolution of each pad is thesame as δx. For example, x = 0 means the resolution is calculated with the layer number 0, 1, and 2
by accumulating x1 − (x0 + x2 )/2 values for all events.
By the error propagation the RMS value of the distribution,σ, and the resolution, δx, have the relation:√
σ = 3/2δx.
0.45
0.4
Resolution (mm)

GET(Generic Electronics for TPCs)1) will be usedas the front-end readout electronics for the newly constructed SπRIT-TPC(SAMURAI pion Reconstruction
Ion-Tracker Time Projection Chamber)2) . The GET
electronics has been recently developed by the GET
collaboration for the particle and nuclear physics experiments and its performance is yet to be evaluated.
We performed a test experiment at the Heavy Ion Medical Accelerator in Chiba(HIMAC) facility using the
BRAHMS-TPC(TPM1)3) to evaluate the performanceof the GET electronics. The TPC has the multi-wire
conﬁguration similar to the SπRIT-TPC: anode wires
for signal multiplication, gating grid wires to reducethe background noise.
We used 300 AMeV 132 Xe beam with 500 mg/cm2
CsI target surrounded with the multiplicity trigger array of 60 scintillator plastics. To evaluate the resolution in both wire and drift directions, in the ﬁrst setup
the BRAHMS-TPC(TPM1) was placed at 60 degrees
oﬀ the beam axis and we took data with diﬀerent sampling rate of 5, 10, 25, 50, 100 and 200 MHz and shaping time of 70, 232, 502 and 1014 ns. Due to breakdownof the µ-TCA power supply, only one AsAd board(256channels) is used in this conﬁguration.
In the second setup the BRAHMS-TPC(TPM1) was
located at 0 deg. We replaced the broken power supply
and took data with three AsAd boards(768 channels)
controlled by a full CoBo(Control Board for 4 AsAd
boards). We tested the gating grid drivers with beam
intensities varying from 102 to 105 pps. We placed
ﬁve 3 mm thick Al plates in front of the TPC to stop
the beam and heavy fragments so that only the lightcharged particles with Z < 3 can reach the TPC at theintensity 104 and 106 pps. Finally, with beam intensity
104 and 105 pps we took data under the SπRIT-TPC
experimental condition: sampling rate of 25 MHz,shaping time of 232 ns, 256 time buckets(10.24 µs),
and zero suppression mode.
Figure 1 shows the preliminary result in the ﬁrst
setup. The resolution is presented as a function of the

0.35

Drift

0.3

Wire

0.25
0.2
0

2
4
6
8
Used Layer (x = [x, x+1, x+2])

10

Fig. 1. Resolution of the wire and drift direction as a function of the layer number x, which is the first layer number among three layers.
Table 1. Resolution from two collaborations
Collaboration
BRAHMS
SπRIT

Direction
wire (µm) drift (µm)
310427
217±10401±22Comparison between the result from both collaborations is summarized in Table 1. Our result is better
because the GET electronics is 12 bit ADC while the
BRAHMS collaboration used 10 bit ADC.
Further analyses in the second setup are ongoing.
References
1) E. Pollacco et al.: Physics Procedia 37 (2012) 1799.
2) R. Shane et al.: Nucl. Instr. and Meth. A 784 (2015)
512.
3) M. Adamczyk et al.: Nucl. Instr. and Meth. A 499(2003) 437.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Status of SπRIT-TPC
M. Kurata-Nishimura,∗1 R. Shane,∗2 A. McIntosh,∗3 T. Isobe,∗1 J. Barney,∗2 J. Estee,∗2 G. Jhang,∗1∗4
W. Powell,∗5 W.G. Lynch,∗2 M.B. Tsang,∗2 T. Murakami,∗6 S. Tangwancharoen,∗2 S.J. Yennello ,∗3for SπRIT-TPC collaboration
The SAMURAI Pion-Reconstruction and IonTracker Time-Projection Chamber (SπRIT-TPC)1)
was constructed at Michigan State University andtransferred to RIKEN RIBF-SAMURAI in February
2014. The main aim of this project is to constrain
the symmetry energy term in the nuclear-matter equation of state (EoS) at supra-saturation density. TheSπRIT-TPC is capable measuring the momentum ofpions and light particles emitted in heavy nuclear collisions, such as 132 Sn + 112 Sn at beam energies of hundreds of MeV/nucleon.
In summer 2014, an installation procedure for the
SπRIT-TPC into the SAMURAI magnet chamber wasdeveloped and verified. The SπRIT-TPC is designed
to maximize the coverage in the SAMURAI magnet
chamber. The internal height of SAMURAI chamber isdesigned to be 800 mm. Bolts, covered by 25 mm highcaps, surround the magnet pole on top and bottom toprevent the chamber from crushing due to the pressure
difference when the chamber is under vacuum. On theother hand, the design height of the SπRIT-TPC is742 mm and thus there is a very small margin of error
for installing it into the SAMURAI chamber. Thus
the confirmation of the installation is one of the mostimportant issues in this project. Also confirmation ofsafe operation in the magnetic field is critical.
The setup for installation of the SπRIT-TPC in thechamber is shown in Fig.1. In this figure, the SAMURAI magnet was oriented at 30 degrees, it is most common experimental configuration. However, the SpiRIT
TPC was designed to sit inside the SAMURAI magnet
chamber when it is oriented at zero degree. To test
the installation procedure without expending a lot of
resources to reconfigure the SAMURAI magnet, theSπRIT-TPC was inserted from one half side of theexit window with the oblique angle. Rails placed in
the chamber extended toward the downstream window where additional rails were located on tables. TheSπRIT-TPC was set on a slider which moves along
rails with negligible friction. It was able to be pushed
and pulled in the chamber using dual hydraulic jacks.
When the SπRIT-TPC was installed inside the chamber, it was raised up about 25 mm to the beam height.
Installing and dismounting the SπRIT-TPC was com∗1
∗2

∗3
∗4
∗5
∗6

RIKEN Nishina Center
National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University
Cyclotron Institute, Texas A&M University
Department of Physics, Korea Universtiy
Department of Physics, University of Liverpool
Department of Physics, Kyoto University- 206 -

pleted in about 20 minutes.
An operational test in the magnetic field was also
performed. Before hand, all magnetic material itemson the SπRIT-TPC were removed. The read out
electronics described in Ref.2) were set up. Finally,
charged particle tracks of cosmic rays and beta source
were detected in a magnetic field ranging from 0.1 to
0.5 T. Figure 2 shows a part of a helical track produced
by a cosmic ray was observed within the detection area
read out by one AsAd electronics board.
Furthermore, a remote controlled target ladder was
mounted inside the TPC-enclosure. The target position is determined by reading the voltage drop between
the fixed and movable contacts on a resistive strip.
The overall geometry and position of the field cage
and the target ladder relative to the enclosure were
measured using photogrammetry2) . The deviationfrom the design value was evaluated as less than 200µm.
In summary, significant progress on the preparation
for the SπRIT-TPC experiment has been achieved.

Fig. 1. Picture of the SπRIT-TPC inserted into the SAMURAI chamber. Left top: picture in the chamber. Leftbottom: schematic view of the installation method.

Fig. 2. Event display for a cosmic ray detected by the
SπRIT-TPC in the SAMURAI magnet at 0.3 T. Enlarged view of the track is on the right.

References
1) R. Shane at al.: Nucl. Instr. Meth. A 784 (2015) 513.
2) http://www.geodetic.com/products/systems/v-stars-s.aspx
3) T. Isobe et al.: in this report.

Y. Togano,∗1,∗2 M. Shikata,∗1 T. Ozaki,∗1 Y. Kondo,∗1,∗2 and T. Nakamura∗1,∗2from 22 Na is shown in Fig. 3. The light output of the
The γ-ray detector CATANA (CAesium iodide arfrom 22 Na
shownatinlarger
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theby thereﬂectionof lights
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Instrumentation
RIKEN
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∗1,∗2
∗1
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Na,
and
Co
sources.
The
geomesensors
forthescintillation
light
from
the
crystalsare
try of the tested crystals is shown in Fig. 1. To eval2) Y. Togano et al.: RIKEN Accel. Prog. Rep. 47, 179
try
of
the
testedcrystals
is
shown
in
Fig.
1.
To
evalthephotomultipliertubes(PMTs)
R580
and
R11265uate the position dependence, the collimated γ rays
(2014).
uate
the position
dependence,the collimatedγ raysfromHamamatsu
Photonics.
detailed
descriptionof
irradiatedthe crystals
from aAdirection
perpendicular3)J.
Bea et al.: Nucl. Instrum. and Meth. A 350, 184
irradiatedthecrystalsfromain2)
direction
CATANAbe foundin ref.
.
to the x −canz planedeﬁnedFig.
1. perpendicular
The collima(1994).
to
the
xa −
plane
Fig.
1. Theeﬃciency
collimadependence
ofinlight
collection
torThewasposition
10zcm
thickdeﬁned
lead witha 1-cm-diameter
hole.
tor
was
a
10
cm
thick
lead
with
a
1-cm-diameter
hole.
can
be
signiﬁcantforthecrystalsof
CATANA,The test was performed for two crystals frombecause
diﬀerThe
test
wasperformedfortwocrystals
from
diﬀerthecrystalshaverelatively
large
volumes.
We
have
ent companies. The two crystals have almost identicalentcompanies.
The
two
crystalshave
almostidentical
testedtheposition
dependence
of
the
light
collection
geometry. We tentatively name the two crystals as A
geometry.
We
name
the
two crystals
as A
eﬃciency
thetentatively
prototype Figure
CsI(Na)by usingγ
and B in ofthis
report.
2 crystals
shows
the
typical
137
22
60
and
B
in
this
report.
Figure2shows
thetypical
rays
from
Cs,
Na,
and
Co
sources.
The
geomeresponse of the crystals A and B to the uncollimatedresponse
oftestedthekeV
crystals
AisfromandB22to
uncollimatedtry
the1275
crystals
shown
in theFig.
1. ToAeval511 ofandγ raysNa.
Crystal
has
22
511
and
1275
keV
γ
rays
from
Na.
Crystalhas
Fig. 2. Typical response of the crystals to the 22 Na source.
uate
theposition
dependence,thecollimatedrays
a better energy resolution than crystal B. TheγAposiFig. 2. Typical response of the crystals to the 22 Na source.
ation
betterenergyresolution
crystaleﬃciency
B. The alongposiirradiatedthe crystals
acollection
direction
perpendiculardependenceof the fromlightthantion
dependenceof thethelight incollection
eﬃciency
to thexlength− z planedeﬁnedFig.
Thecrystalz ofcrystalsA
and1.Btothecollimaγalong
rays
crystalz oftheleadcrystals
B to the γ hole.
rays
tor was lengtha 10 cm
thick
withAa and1-cm-diameter
The test was performed for two crystals from diﬀerent companies. The two crystals have almost identicalgeometry. We tentatively name the two crystals as A
and B in this report.
Figure 2 shows the typicalresponse of the crystals A and B to the uncollimated
511 and 1275
rays from 22 Na. crystals
Crystal A has
TestkeVofγ prototypeof the γ-ray detector CATANA
Fig. 2. Typical response of the crystals to the 22 Na source.
a better energy resolution than crystal B. The position dependenceY.
of Togano,the light∗1,∗2
collection
eﬃciency∗1
M. Shikata,T.along
Ozaki,∗1 Y. Kondo,∗1,∗2 and T. Nakamura∗1,∗2
crystal length z of the crystals A and B to the γ raysfrom 22 Na is shown in Fig. 3. The light output of the
The γ-ray detector CATANA (CAesium iodide arcrystal B is larger at larger z. This tendency is due toray
γ-ray Transitionsin Atomic
at highFig. for1. Geometryof the tested
prototypeNuclei
crystals.
The
Fig.deﬁnition
1. GeometrythetestedprototypeThethefocusing
causedofby
thereﬂectionof eﬃciency
lights at
isospin
Asymmetry)has
beendeveloped
to measureof theofaxis
inthe testis also crystals.
shown.
PMT
Fig. optical
3. Position
dependence
the
light
collection
3)
deﬁnitionof theaxistopin ofthethetest
is alsoshown.
thepolished
surfaceof
crystalB
γ rayassociatedhighlyexcitedstateslikePMTthe.
To
obtaina crystalbetter
Fig.for3. thePosition
dependence
of
the
light
collection
eﬃciency
wasattached
to withthecrystals.
crystals A (red) and B (black) along thewas dipole
attached
to the topof the giant
crystals.
pygmy
resonance
and/ordipoleresonance.
position
dependence
andenergyresolution,changesinforthecrystals
A
(red)
and
B
(black)along
thecrystallength z. Crystal B shows larger position dependence∗1 Department of Physics, Tokyo Institute of Technology
1)
CATANA
will
be
used
with
SAMURAI
at
RIBF.
the
reﬂectivityofthecrystalA
surfaces
wererealizedThelengthz.
CrystalB
showslargerposition
dependence∗1∗2 RIKENof the light collection eﬃciency.
Departmentof Physics,
Nishina
Center Tokyo Institute of Technology∗2 RIKEN Nishina
by roughening
the crystal
surfaces.
excitationenergy Center
will be reconstructed by combiningof the light collection
eﬃciency.
The fabrication of the CsI(Na) crystals for CATANA
the invariant mass of the reaction products measured
will start in spring 2015, and ﬁnish in late 2015.
by SAMURAI and γ-ray energies from CATANA.
The CATANA array consists of CsI(Na) crystals andReferences
has between 10 and 15 cm thickness. The crystals are1) T. Kobayashi et al.: Ncul. Instrum. and Meth. B 317,
housedin 0.5-mm-thickaluminumboxes.crystals.
The photoFig. 1. Geometryof the tested
prototypeThe
294 (2013).
sensors
for thelighttheshown.
crystalsPMT
aredeﬁnitionof scintillation
the axis in thetestfrom
is alsoFig. 3. Position dependence of the light collection eﬃciency
2)
Y.
Togano et al.: RIKEN Accel. Prog. Rep. 47, 179
the wasphoto
multiplier
R580 and R11265
attached
to thetubes
top of(PMTs)
the crystals.
for the crystals A (red) and B (black) along the crystal(2014).
fromHamamatsu Photonics. A detailed description oflengthB shows
largerdependence∗1 Department of Physics, Tokyo Institute of Technology
3) J.
Bea z.
et Crystalal.: Nucl.
Instrum.
andposition
Meth. A
350, 184
2)
CATANA
be
found
in
ref.
.
∗2 RIKEN can
of
the
light
collection
eﬃciency.
Nishina Center(1994).
The position dependence of light collection eﬃciency
can be signiﬁcant for the crystals of CATANA, because
the crystals have relatively large volumes. We havetested the position dependence of the light collection- 207 eﬃciency of the prototype CsI(Na) crystals by using γ
rays from 137 Cs, 22 Na, and 60 Co sources. The geometry of the tested crystals is shown in Fig. 1. To eval-

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Isotope separation with new ion-optics mode
H. Takeda,∗1 T. Kubo,∗1 N. Fukuda,∗1 H. Suzuki,∗1 N. Inabe,∗1 and H. Geissel∗2
Two-stage structure is an important feature of the
in-ﬂight fragment separator BigRIPS.1) The ﬁrst stage,
which consists of two dipoles (D1 and D2) and four
superconducting triplet quadrupoles (STQs) (STQ14), is located between the production target F0 andachromatic focus F2 with the momentum dispersive
focus F1. The second stage, which consists of four
dipoles (D3-D6) and eight STQs (STQ7-14), is locatedbetween the achromatic foci F3 and F7 with the momentum dispersive foci F4, F5, and F6. The stage between F2 and F3, which consists of two STQs (STQ56), acts as a matching section. Rare-isotope (RI) beam
is produced and separated in the ﬁrst stage with anenergy-loss degrader at F1, and particle identiﬁcationand momentum analysis are performed in the second
stage.1,2) Another energy-loss degrader placed at F5 isoften eﬀective when unwanted isotopes are transmitted
as a result of the charge state change or the secondary
reaction in the ﬁrst degrader at F1. The thicknesses
and shapes of the degraders at F1 and F5 are chosen
so as to optimize the RI beam according to the experimental requirements.
The two stages act independently and their isotopic
separation power can be added or subtracted, depending on the experimental condition. When the separation powers of the two stages are subtracted, the horizontal spatial distance of the separated isotopes becomes small at the ﬁnal focus F7. Adding the isotopic
separation powers of the two stages would increase thehorizontal spatial distance. Because widths also increase, improvement of the ﬁnal resolving power will
depend on the experimental condition.
The ion-optical solution for adding the separation
power can be realized by having either one or threefoci in the matching section F2-F3, which have twofoci (F2 and F3) in the standard mode. At least one
focus in the standard mode is abandoned in the formercase. It is not desirable because both F2 and F3 areimportant for slits and diagnostics of the RI beam.
Therefore, here we present the solution having threefoci.
Figure 1 shows the horizontal (X) and vertical (Y )tracks of the beam from F0 to F7 obtained from the solution of the ﬁrst-order ion-optical calculation. In thissolution, ion-optical conditions of the two stages (F0F2 and F3-F7) are the same as the ones in the standard
mode. Only the matching section F2-F3 is modiﬁed tohave an additional focus in the X direction at the midpoint “F2.5” between F2 and F3, while the beam is not
focused in the Y direction at F2.5 to reduce excitation∗1∗2

Fig. 1. Horizontal (X) and vertical (Y ) tracks of the beamin the new mode.

Fig. 2. Comparison of tin isotope distribution at F7 between the standard mode (left) and new mode (right)
simulated with LISE++ .

currents of STQ5 and STQ6. Reversing the polarityof all quadrupoles of the two STQs is also necessary to
reduce the currents. The maximum magnetic rigidity(Bρ) of 8.7 Tm is achieved in this solution. The value
is almost the same as the maximum Bρ of the second
stage (8.8 Tm). There is a trade-oﬀ between achieving
high Bρ and large acceptance.
Figure 2 shows an example of horizontal distributions of tin isotopes at F7, simulated by LISE++ , in a
238
U + Be 4 mm reaction at 345 MeV/nucleon using
3 mm- and 2.2-mm-thick aluminum degraders at F1and F5, respectively. The spectrometer is tuned for132
Sn with D1 Bρ = 7.49 Tm. The left and right panels show the results in the standard and new modes,
respectively. In the standard mode, all isotopes accumulate in the center (X = 0) because of the subtraction of the separation power. In contrast, the isotope
separation is improved in the new mode.
Note that the diﬀerence between the two modes issmall for separation of isotones because they often collect at approximately the same position at F2. Altering the combination of energy and degrader thickness
is required for isotone separation.
A machine study for the new ion-optical mode proposed here had been scheduled in November 2014, but
was cancelled. We expect to perform this study in thenext year.
References
1) T. Kubo: Nucl. Instr. Meth. B204, 97 (2003), T. Kubo
et al.: Prog. Theor. Exp. Phys. 2012, 03C003 (2012).
2) N. Fukuda et al.: Nucl. Instr. Meth. B317, 323 (2013).

RIKEN Nishina Center
GSI Helmholtzzentrum für Schwerionenforschung GmbH

- 208 -

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

A NaI(Tl) detector array for measurements of γ rays from fast
radioactive isotope beams †S. Takeuchi,∗1 T. Motobayashi,∗1 Y. Togano,∗2 M. Matsushita,∗3 N. Aoi,∗4 K. Demichi,∗5 H. Hasegawa,∗5 andH. Murakami∗1
The recent development of fast radioactive ion (RI)
beams requires a new type of γ-ray detector array forin-beam spectroscopic studies. Experiments are performed in inverse kinematics by using fast RI beams
with a high velocity of v/c ≃ 0.3 − 0.6 that causesa large Doppler shift for γ rays emitted. In order toextract the transition energy in the rest frame of the
projectile, precise measurements of emission angles ofγ rays as well as a good intrinsic energy resolution
are required. Another requirement for γ-ray detection
is high eﬃciency, because the secondary-beam intensity for nuclei far from stability is typically low. The
RIKEN RIBF provides the world’s highest intensity
exotic beams to study unstable nuclei. To capitalizeon the performance of RIBF, we have constructed a
new γ-ray detector array called DALI2 (Detector Array for Low Intensity radiation 2) for in-beam γ-ray
spectroscopy experiments.
The design of the DALI2 array follows a concept
similar to the original array DALI1,2) , which was developed for experiments at the old facility at RIKEN thatprovides light exotic beams with v/c ≃ 0.3. In experiments performed at the new RIBF facility providing
higher-velocity exotic beams with v/c ≃ 0.6, the performance of DALI is not optimized. Therefore, DALI2
was designed to fulﬁll the required conditions for experiments performed at the RIBF facility by improving
the angular resolution and the detection eﬃciency. In
order to compromise on requirements such as intrinsic
resolution, detection eﬃciency, and cost, we adopted
NaI(Tl) as the detector material. The DALI2 arrayconsists of a large number of detectors, 160-186, which,depending on the experimental conditions, are at various distances from the target. As shown in Fig. 1, thedetectors are arranged to form twelve layers that are
set perpendicularly to the beam axis, and a detector
matrix covers the forward angles. Each layer consistsof 6-14 detectors and the forward matrix consists of 64
detectors. In this standard conﬁguration, DALI2 cancover a polar angle between 15◦ and 160◦ .
The performance of DALI2 was examined by using measurements with standard γ sources and by
performing the Monte Carlo simulations with the
GEANT3 code3) . Simulations reproduce measurements
†
∗1
∗2
∗3
∗4
∗5

Condensed from the article in Nucl. Instrum. and Methods
in Phys. Res. Sect. A, 763, 596 (2014)
RIKEN Nishina Center
Department of Physics, Tokyo Institute of Technology
CNS, University of Tokyo
RCNP, Osaka University
Department of Physics, Rikkyo University- 209 -

Fig. 1. Schematic view of DALI2 in its standard configuration consisting of 186 NaI(Tl) crystals.

well, including results obtained by in-beam experiments. A typical full-energy-photopeak resolution of
10% (FWHM) and 20% eﬃciency are achieved for 1MeV γ rays emitted from moving nuclei with v/c ≃ 0.6
without applying add-back analysis. This resolution
is satisfactory for spectroscopy of low-lying states ineven-even nuclei. The high eﬃciency enables γ-γ coincidence measurements even for beam intensity as low
as 1 Hz. The DALI2 array has been applied successfully to a variety of experiments at the old RIKEN
facility and more recently at the new RIBF facility.
This will be used in many more experiments to study
nuclear structures of exotic nuclei at RIBF. For further spectroscopic studies of heavy or odd-mass nuclei,
the SHOGUN array with superior energy resolution isplanned4) .
References
1) T. Motobayashi et al.: Phys. Lett. B 346, 9 (1995).
2) T. Nishio et al.: RIKEN Accel. Prog. Rep. 29, 184(1996).
3) GEANT3, CERN Program Library Long Writeup
W5013, 1993.
4) P. Doornenbal et al.: RIKEN Accel. Prog. Rep. 42, 182(2009).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Development of a total-kinetic-energy counter for high-rate
experiments at ZeroDegree spectrometer
R. Taniuchi,∗1,∗2 H. Wang,∗2 N. Aoi,∗3 H. Baba,∗2 S. Koyama,∗1,∗2 M. Kurokawa,∗2 M. Matsushita,∗4
S. Momiyama,∗1,∗2 M. Niikura,∗1 Y. Shiga,∗2,∗5 and S. Takeuchi∗2
A total-kinetic-energy (TKE) counter for particle identification at the ZeroDegree (ZD) spectrometer was tested in 2014. The detector is aimed at
the discrimination of not fully stripped ions for themass region A  100. For example in the case of136
Sn (RIBF31), the mass-to-charge ratios (A/Q) of
133
Sn49+ and 136 Sn50+ are similar and the resolutionof A/Q obtained by the TOF−Bρ−∆E method is not
sufficient to separate them. In order to separate thefully stripped ions from the neighboring charge-state
contaminants, the TKE counter is required to havethe mass resolution of 1% (FWHM).
Considering the beams with high counting rate(∼100 kcps), the counter should have a short decay
time and radiation resistance. For this purpose, aø3′′ LaBr3 (Ce) scintillatora) with a 0.5-mmt aluminum
housing is preparedb) . It is mounted downstream of theF11 multiple sampling ionization chamber (MUSIC).
In previous studies1–3) , the feasibility of charge-state
identification using this scintillator was tested. The
mass resolution was not as good as 1% (FWHM). Simultaneously, a quenching phenomenon was observed
3), namely, the light yield per energy deposition of
the incident beam decreased as a function of Z. To
obtain higher resolution, the degree of the quenching
phenomenon should be known for the optimization of
the amplification factor of the light readout.
In 2014, two types of light readouts were tested. For
the first case (tested in the experiments RIBF31R1 andDA14-01-01), five PIN-photodiodes (S3204-08, HPK)
were aligned on the downstream surface of the scintillator4) . For the second setting (tested in the experiments RIBF61, RIBF51R1 and RIBF56R1), the readout consisting of a ø3′′ PMT (R6091HA, HPK) and atapered-type divider (E5859, HPK) were coupled withthe scintillator. In this report, the result of the second
setting is discussed.
During three experiments, the amplitudes of thesignal of the PMT were measured using an oscilloscope with several high-voltage (HV) settings. The
ZD spectrometer were set for 132 Sn (20.8 GeV), 70 Ni(15.2 GeV), and 22 O (5.21 GeV)c) , for the respective
∗1
∗2
∗3
∗4
∗5
a)
b)
c)

Department of Physics, the University of Tokyo
RIKEN Nishina Center
Research Center for Nuclear Physics, University of Osaka
Center for Nuclear Study, the University of Tokyo
Department of Physics, Rikkyo University
Saint-Gobain BrilLanCeTM 380
LaBr3 (Ce) is known to have a light decay time around 16 ns.
The kinetic energies of heavy ions are deduced from the Bρ
values of the last dipole of ZD spectrometer.

- 210 -

Fig. 1. Amplitude of the PMT output with several HVs foreach ZD spectrometer settings.
Table 1. Signal amplitudes per unit energy.
Particleγ/δ-ray
22 O
70 Ni
132 SnAmplitude (mV/GeV)
124
40
19
15

Quenching factord)
1
0.32
0.16
0.13

experiments. Figure 1 shows the signal amplitudes asa function of applied HV for different isotopes. For
reference, data of γ-ray calibration before and after
the experiment with 22 Na, 60 Co and 137 Cs sources arealso plotted. They are normalized by the energy of the
γ-ray, namely, the amplitudes per 1 MeV.
For the 132 Sn and 22 O settings, owing to the frequent
implantation rate (∼40-100 kcps) and high light yield,
the PMT output was saturated with overcurrent of thedivider circuit when the HV value was above 700 V.
On the other hand, the slopes below 700 V are similar
to the one of γ-ray. This ensures that the PMT has
linearity even for the lower operation voltage.
By extrapolating the γ-ray results to the lowervoltage region, the light yield of the scintillator is compared with heavy ions. The values in the center columnof Table 1 are the signal amplitudes per the kinetic energies when the HV is set at 650 V. The quenching
phenomena of the light yield are observed obviously.
According to this result, optimum gain of the PMT
can be discussed. A new divider circuit designed fromthis result will be tested in 2015.
References
1) Yuta Hara, Master thesis, Rikkyo University, 2010.
2) Riyato Kambayashi, Master thesis, Rikkyo University,
2011.
3) Kota Kobayashi, Master thesis, Rikkyo university, 2012.
4) He Wang et al., in print.
d)the ratio of the signal amplitudes per energies of heavy ionsto that of γ-ray.

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Low-pressure MWDC system for ESPRI experimentY. Matsuda,∗1,∗2 J. Zenihiro,∗2 W. Chao,∗2,∗3 H. Sakaguchi,∗2,∗4 J. Tanaka,∗4 M. Tsumura,∗2,∗5 and
N. Nakatsuka∗2,∗5

MWDC

310 mm

Beam

MWDC

(a)

1000 mm(c)(b)

Vacuum gauge
HV connectors
Gas in/out

∗2
∗3
∗4
∗5

V5

V9

V8

V6
640B

V3

V10

SS-4MG
SS-4L

V1

V2

V11

V12

INFICON
VGC402

MWDC

Leak port
To dry pump

From gas cylinder

CDG025D

Gas
handler

CDG025D

V4

Vacuum chamber

MWDC

Fig. 2. Schematic diagram of the gas handler system.

Efficiency [%]100 Total
W1
80

W2
C1
C2

60
40
20

400
300
500
High voltage [-V]600

Fig. 3. Detection eﬃciency for the 200 MeV/nucleon Xe
beam. The beam intensity was 6×103 particles per
pulse (pulse width 1 s). The threshold voltages of theASDs were -20 mV. Deﬁnition of the symbols is thesame as in Ref. 3.

ASD

MWDC

MWDC

X-X ′ -Y -Y ′ -X-X ′ -Y -Y ′77.5 mm(X) × 77.5 mm(Y )2.5 mm (Anode-Potential)
4.8+0.0−0.1 mm (Cathode-Cathode)
W-Re / Au (Diameter: 16 µm)
Al / Au (Diameter: 80 µm)
Kapton / Al (Thickness: 7.5 µm)
Aramid (Thickness: 4 µm)

Conﬁguration
Eﬀective area
Drift length
Gap
Anode wire
Potential wire
Cathode foil
Window foil

200

Fig. 1. Schematic layout of the MWDC system: (a) verticalsectional, (b) cross sectional, (c) front views.
∗1

Table 1. Speciﬁcation of each MWDC. The design was
based on the MWDC for SAMURAI2) .

0

Vacuum chamber

Beampurity of more than 99%. The eﬃciency reached 100%
without any electric discharge. In addition, position
resolution for each plane was about 60 µm (rms).
In summary, we constructed a low-pressure MWDC
system. By using the 132 Xe beam and the i-C4 H10gas, basic characteristics were evaluated for the beam
intensities of 103–4 pps. We will further study thesequantities for the beam intensities of 105–6 pps.

MKS 246C

Elastic scattering of protons with RI beams (ESPRI)
has been used to study the ground-state properties of
unstable nuclei1) . In order to achieve good energy resolution in the experiment, position and angular resolutions of 100 µm and 0.1 mrad are required at a positionof the solid hydrogen target. The typical energy andintensity of the beam are 200-300 MeV/nucleon and
105–6 particles per second (pps), respectively. This report describes a multi wire drift chamber (MWDC)
system newly constructed for this purpose.
Figure 1 shows a schematic layout of the system, andTable 1 shows the speciﬁcation of the MWDC. Two
MWDCs are installed inside a vacuum chamber at a
distance of 1 m. Through the SHV connectors, negative potentials are applied to the cathode planes andthe potential wires against the anode wires. Signals
from the anode wires are converted into LVDS signals
by the ASDs (GND, GNA-210), and fed to multihit
TDCs.
The chamber including the MWDCs, with volumeof about 25 L, is ﬁlled with 100% quench gas (CH4 ,C2 H6 , i-C4 H10 ) at low pressures to reduce multiple
scattering of the beam. Figure 2 shows a schematic
diagram of the gas handler system. The pressure of
the gas is controlled with a pressure controller (MKS,
640B), and measured with two vacuum gauges (INFICON, CDG025D-X3). The ﬂow rate is adjusted witha metering valve (Swagelok, SS-4MG / SS-4L).
Basic characteristics of the system were evaluatedwith a 132 Xe beam at HIMAC. Figure 3 shows thedetection eﬃciency as a function of the bias voltage
when i-C4 H10 (99.5%) was used at 6666 Pa. Deﬁnitionof symbols in Fig. 3 is the same as in Ref. 3. The ﬂow
rate was about 100 cc/min at 1 atm to maintain the

References
1) Y. Matsuda et al.: Phys. Rev. C 87, 034614 (2013).
2) T. Kobayashi et al.: Nucl. Instr. and Meth. B 317, 294(2013).
3) Y. Matsuda et al.: Nucl. Instr. and Meth. A 670, 25(2012).

Department of Physics, Konan University
RIKEN Nishina Center
Department of Physics, Peking University
RCNP, Osaka University
Department of Physics, Kyoto University- 211 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

NiGIRI: Identification of n, p, d, t, 3,4He, 6,7Li, and γ-rays†
H. Matsuzawa,∗1,∗2 S. Nishimura,∗2 T. Isobe,∗2 G. Lorusso,∗2 M. Kurata-Nishimura,∗2 and K. Ieki∗1
The azimuthal angle correlation of neutrons andcharged particles with respect to the reaction plane inheavy-ion collisions is expected to provide essential information on the equation of state (EOS) of high density nuclear matter in supernovae and neutron star.
A new scintillation detector NiGIRI (Neutron, ion,and γ-ray Identification for Radioactive Isotope beam),comprises two types of PMTs (Hamamatsu H11265200, R8520-20-12) attached on both sides of a plastic
scintillator EJ299-33 (30×55×127 mm3 ), is designed tomeasure the positions and energies of neutrons (≥ 100keV) and charged particles (π ± , p, d, t, 3,4 He, 6,7 Li, ..)with pulse-shape discrimination (PSD) capability1–3) .
A feasiblity study of the NiGIRI detectors was performed using 132 Xe + CsI collisions at energies of
400 AMeV at HIMAC. The energies and positions ofcharged particles were reconstructed and identified using the correlations of energy losses (∆E), timings, and
PSDs among the different layers of NiGIRI detectors.
Sixty four signals (32 NiGIRI detectors x 2 PMTs),
recorded with a synchronized wave-dump mode of four
flash ADC modules (CAEN V1730B; 500 MHz with 14bits), were analyzed to deduce the integrated charge,
timing, and PSD offline.
Figure 1 demonstrates the particle identification of
low energy p, d, t, 3,4 He, and 6,7 Li in the energy correlation of the 1st layer of NiGIRI (E) and a chargedparticle veto plastic scintillator (CPV: 2 mmt ; ∆E).
The punch-through charged particles with higher energy were identified using up to 8 layers of NiGIRI
detectors.

Fig. 1. Correlation between the veto counter (∆E) and 1st
layer (E).

Particle identification of neutrons was tested using
the PSD, which is the ratio of the total charge-integral(gate width = 385 ns) and tail charge-integral (gatewidth = 360 ns; delay = 24 ns) of each PMT signal. The energy dependences of the PSD for charged∗1∗2

Department of Physics, Rikkyo Univ.
RIKEN Nishina Center- 212 -

particles (Fig. 2a: events with CPV signal) and neutral particles (Fig. 2b: events with no CPV signal)
show separation of particles among (p-d-t)-(He)-(Li)and (γ)-(n), respectively. The energies of these ionscan be deduced using the time-of-flight (TOF) between
the CsI target and the NiGIRI detectors, which is also
useful for the consistency check with the energy losses
in the NiGIRI detectors. π ± production can also be
studied by tagging stopped π decays in wave-dump
signals of the last NiGIRI detector.

Fig. 2. PSD of the 1st layer main PMT of charged particles(a) and neutrons and γ-rays (b). Charged particle after
CP veto in (b) is simply due to insufficient coverage of
the NiGIRI detector.

Figure 3 shows the proto-type NiGIRI arrays arranged with full azimuthal coverage. Upgraded NiGIR detectors will be applied at RIBF to study theneutron-proton differencial flow at target rapidity inneutron-rich nucleus collisions, where reaction plane
will be determined by measuring the squeeze-out outof-plane flow in mid-rapidity region.

Fig. 3. Thirty two NiGIRI detectors (16 arrays x 2 layers) arranged at target rapidity for multiplicity measurement.

References
1) S.A. Pozzi et al.; Nucl. Instr. Meth. A 723, 19-23 (2013)2) S. Nyibule et al.; Nucl. Instr. Meth. A 728, 36-39 (2013)3) H. Matsuzawa et al.; RIKEN Accel. Prog. Rep. 47(2015)

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Proposal of novel delayed-neutron branching ratio measurements
using MRTOF
M. Wada,∗1 P. Schury,∗1 and Y. Ito,∗1∗1

RIKEN Nishina Center- 213 -

gas cell

MRTOF

pure beam
beam
pure

n

Fig. 1. Sketch of setup for Pn measurement with MRTOF

94 Kr

94Br

Counts

The astrophysical r-process plays important roles insynthesis of heavy elements in the universe1) . The rprocess pathway is dominantly determined by the neutron separation energies of neutron-rich nuclei and theabundance of the elements strongly depends on thehalf-life of the nuclei in the pathway. In addition tothese two dominant nuclear properties, the delayed
neutron emission probabilities (Pn ) and the neutron
capture cross sections (σn ) contribute partially to theelement abundance. The cross section does not contribute during equilibrium, but strongly affects thefreeze-out stage. However, direct neutron capture crosssections of very neutron rich nuclei is so far very difficult to determine experimentally2) . During freeze-out,the β-decay path towards stability is defined by Pn .
Although almost all nuclei in the r-process pathway
have non-negligibly finite Pn , only a limited number ofthem are experimentally determined.
So far the experimental Pn values have been determined by a limited variety of methods: direct detectionof delayed-neutron by 3 He gas counters, detection ofrecoil ions in an ion trap3) , and radiochemical identification of daughter nuclei. We propose a novel method
using a gas catcher cell and a multi-reflection time-offlight mass spectrograph (MRTOF-MS). The principle
is the same as the radiochemical method. All daughter
nuclides are identified and the yields are compared todetermine Pn . In the radiochemical method, characteristic γ-rays and their branching ratios are needed toobtain the yields, however, they are often unknown insuch very neutron rich nuclei. In the new method, we
identify the daughters and remaining precursor ions by
the MRTOF-MS. Figure 1 shows a schematic drawingof the experimental setup. The injected precursor nuclear ions are first thermalized in the gas catcher anddecay in the cell. The decay products are also thermalized in the cell and then extracted from the cellusing an rf-carpet and transport to the MRTOF-MS.
The recoil products are identified by the mass spectrograph. Figure 2 shows a schematic mass spectrum forthe case of 94 Br. Note that remaining precursor and β
decay recoil, single neutron decay recoil, two neutron
decay recoil and their daughters (grand daughters of
the precursor) are all identified in a single spectrum.
It is especially important that the isobaric pair of the
precursor and the β-decay product (without neutron
emission) can be clearly separated. Such simultaneous detection of multiple atomic mass numbers alongwith separation of isobaric ions is a unique feature of
MRTOF-MS4) . It is difficult to achieve such capabil-

93Kr

Kr

92Kr

Kr

A=94

A=93

A=92

TOF

Fig. 2. Schematic time of flight spectrum showing the precursor 94 Br, β-decay daughter 94 Kr, delayed single neutron decay recoil 93 Kr, delayed two neutron decay recoil92
Kr and their daughters.

ities in any other type of separator. The β-delayed
neutron decay probabilities can be obtained:
Pn = N (A − 1)/N0 ,P2n = N (A − 2)/N0 ,N0 = N  (A) + N (A − 1) + N (A − 2),

(1)
(2)
(3)

where N (A−x) is the sum of x-neutron branch, N  (A)is β-decay recoil and daughters excluding the remaining precursor, and N0 corresponds to the total β-decay
number.
Thus obtained Pxn have ambiguities due to mixingof the daughter’s Pxn . However, this can be correctedby an independent measurement using the daughter asa precursor. Moreover, for astrophysical applications,the final mass distribution from a single precursor is
the required data. Another possible uncertainty canbe attributed to the decay in MRTOF, however, thisfraction can be evaluated if the lifetimes are known.
In case a cocktail RI beam is provided, one can still
determine Pn by solving a linear algebra of the final
distributions of isotopes in a few different but known
distributions of the cocktail beams.
References
1) E. Burbidge et al, Rev. Mod. Phys., 29 (1957) 547.
2) T. Yamazaki et al., Nucl. Inst. Meth. A325 (1993) 489.
3) Y. M. Yee et al., Phys. Rev. Lett. 110 (2013) 092501.
4) P. Schury et al., Int. J. Mass Spectrom., 359 (2014) 19.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Advanced development of GARIS-II using He-H2 mixture
as a filled gas toward the study of superheavy element
D. Kaji,∗1 K. Morimoto,∗1 H. Haba,∗1 Y. Wakabayashi,∗1 M. Takeyama,∗1,∗2 S. Yamaki,∗1,∗3 K. Tanaka,∗1,∗4
and K. Morita∗1,∗5

∗1
∗2
∗3
∗4
∗5

RIKEN Nishina Center
Department of Physics, Yamagata University
Graduate School of Science, Tokyo University of Science
Department of Physics, Saitama University
Department of Physics, Kyushu University- 214 -

lish a suitable condition to study SHE using the He-H2
mixture, further investigation is in-progress.

   


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
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ρ 
 


Fig. 1. Yield curve of 214 Th as a function of magnetic rigidity for various He-H2 mixture gases (○:pure He, ▽:10%
H2 , □:20% H2 , △:36% H2 ). Each solid curve is a Gaussian function fitted to data points.

( 
    

Performance of a gas-filled recoil ion separator(GARIS-II) has been investigated using various asymmetric fusion reactions1–5) . The studies have indicatedthat the separator has a large transmission under alow-background condition in comparison with GARIS
and that the separation of unwanted particles is improved using He-H2 mixture as a filled gas. The lowbackground condition is very important for identifying
superheavy elements (SHE) produced with a low crosssection of pb-order. Therefore, the usefulness of He-H2
mixture as a filled gas toward the study of SHE was investigated further in this work. As a typical example,
results for 214 Th, which was produced via the reactionof 197 Au(23 Na,6n), are given here.
The reaction products of 214 Th were separated inflight from projectiles and other by-products using
GARIS-II, and then they were guided into a double
sided silicon detector after passing through a time-offlight detector1–3) . The separator was filled with He-H2
mixture gases with various H2 mixing ratios (0, 10, 20,
and 36%). The gas pressure was maintained 47 Pa.
The yields of 214 Th, which was assigned from an
α-transition of 7.678 MeV, were measured by varying
the fraction of H2 composition from 0 to 36% as shownin Fig. 1. Each yield is plotted against the magnetic
rigidity Bρ. The optimum Bρ value was determinedby fitting to the data points using a Gaussian function.
The optimum Bρ value was shifted from 1.711 to 1.821
Tm by increasing the mixing ratio of H2 from 0 to 36%,
and the yields of 214 Th were enhanced 1.43 times.
The shift of the optimum Bρ value implies that theequilibrium charge state q of recoil ions moving in afilled gas becomes small. The q, which was deduced
from the optimum Bρ values, are plotted against the
mixing ratio of H2 in Fig. 2. The q was decreased
with increasing H2 composition. The q
in pure H2
can be estimated to be 3.58 using empirical systematics, which was obtained using a Dubna gas-filled recoil
separator DGFRS6) . Interpolated values of q between
4.28 and 3.58 in the case of pure He and H2 are indicated as a broken line in Fig. 2. The interpolation wellagrees with the obtained q values using various mixing ratios within an error bar. On the other hand, thetransmission is improved with increasing the mixing
ratio of H2 , although the width parameter ∆Bρ/Bρ
becomes slightly worse from 8.4% to 9.4%. To estab-
'%*'
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Fig. 2. Equilibrium charge state of 214 Th ions moving ina He-H2 mixture. Interpolation between experimentally obtained q of 4.28 and estimated q of 3.58 fromDGFRS’s work6) is indicated as a broken line.

References
1) D. Kaji et al.: J. Radioanal. Nucl. Chem. 303, p.1523(2015).
2) D. Kaji et al.: JPS Conf. Proc. 1, p.013051 (2014).
3) D. Kaji et al.: Nucl. Instrum. Methods B 317, p.311(2013).
4) D. Kaji et al.: RIKEN Accel. Prog. Rep 47, (2014) [Inprint].
5) D. Kaji et al.: RIKEN Accel. Prog. Rep 46, p.189(2013).
6) Yu. Ts. Ogganessian et al.: Phys. Rev. C64, p.064309(2001).

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Pulse shape analysis for short-lived decay of superheavy elements
S. Yamaki,∗1,∗2 K. Morimoto,∗1 D. Kaji,∗1 Y. Wakabayashi,∗1 M. Takeyama,∗1,∗3 K. Tanaka,∗1,∗4 H. Baba,∗1
T. Yamaguchi,∗2 T. Suzuki,∗2 and K. Morita∗1,∗5
In heavy or superheavy element research, it is important to know the α decay energies and half-lives of
the nuclei to conﬁrm that objective nuclei have been
formed. The α decay half-lives of these nuclei are very
short (0.1-1 µs) for heavier Z according to some theoretical calculations. However in the traditional system,
the combination of a shaping ampliﬁer and PH-ADC
cannot separate sequential events within 1 µs. To measure the α decay properties of such short-lived nuclei,
a digital data acquisition system with ﬂash-ADC was
implemented in the GARIS-II1) read-out system. In
the new system, waveforms from a preampliﬁer are directly registered with ﬂash-ADC SIS3301 to avoid thesumming phenomena caused by pileup in the shaping ampliﬁer. Figure 1 shows the PH-ADC read-out
and ﬂash-ADC read-out systems. The DAQ systems
for the PH-ADC and ﬂash-ADC are operated independently. Separately obtained data are synchronized by
the LUPO time-stamp module.

170 ns). The larger MTOT events from this peak correspond to pileup ones. For example the MTOT
∑116 forthe waveform in Fig.2(a) is calculated as ( t=83 t +
∑305
∑116
∑305
t=273 t)/(t=83 +
t=273 ) − 83 = 109.8 (> 17).
Therefore, this event is treated as a pileup one.
(a)pileup events

single events

vth

Fig. 2. (a) An example of a pileup pulse (upper panel)and its diﬀerential (lower panel). (b) MTOT histogram
when 241 Am α was implanted in the PIN diode.

In the second stage, template ﬁtting for each pulse
was performed3) . The template was made by averaging
10000 241 Am α waveforms for each channel. The ﬁtting
function is given as:
f (t) = A[0] · template(t − A[1]) + baseline,

Fig. 1. The setup of PH-ADC and ﬂash-ADC read-out systems.

In a recent study, a pulse shape analysis (PSA) algorithm for the waveforms from the GARIS-II read-out
system was developed2) . PSA was tested using oﬀ-line
tests. 241 Am α was implanted in a Si PIN photodiode(Hamamatsu S3204) and the signal was preampliﬁedby the Clear Pulse 579. The sampling rate was 100
MHz. Some pileup events occurred when the α source
was set close to the detector. Figure 2(a) shows an example of a pileup pulse. In order to distinguish pileup
events from single events, the weighted mean in timeover threshold (MTOT) method for the diﬀerentiatedwaveforms was developed and applied. MTOT is deﬁned as:
∑tm
{
twt
1 (vt ≤ vth )MTOT = ∑t=0
−T,
w
=
, (1)
t
tm
0 (vt > vth )
wt

(b)

(2)

where the free parameters (A[i]; i = 0, 1) represent thepulse height and time oﬀset. The baseline is an averageof the data from t = 0 to the start of the pulse. For asingle pulse, an energy resolution of 25 keV (FWHM)
for 5486 keV α was obtained, while a resolution of 20
keV was obtained using the original PH-ADC system.
In addition the shortest time interval between sequential events identiﬁed by PSA was 349 ns (Fig. 3). Theenergies of the ﬁrst and second pulses were 5494 keV
and 5444 keV, respectively. Further development of
PSA is now underway.

t=0

where t is the time, tm is the sampling period (800clock), vt is the voltage, vth is the voltage threshold,and T is the minimum t when wt = 1. Figure 2(b)shows a histogram of the MTOT. The peak that corresponds to single events is seen around 17 clock (=Fig. 3. Pileup pulse (dotted line) and ﬁtting of this event(solid line). From this ﬁtting, the time interval between
two events was determined to be 349 ns.

∗1

References

∗2
∗3
∗4
∗5

RIKEN Nishina Center
Department of Physics, Saitama Univ.
Graduate School of Science and Engineering, Yamagata
Univ.
Faculty of Science and Technology, Tokyo Univ. of Science
Department of Physics, Kyusyu Univ.

- 215 -

1) D. Kaji et al.: Nucl. Instr. and Meth. B 317, 311 (2013).
2) S. Yamaki et al.: Proc. ARIS2014 in print.
3) S.N. Liddick et al.: Nucl. Instr. and Meth. A 669, 70(2012).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Performance of ion surfing rf-carpet for high-energy RI beam gas
catcherF. Arai,∗1,∗2 Y. Ito,∗2 I. Katayama,∗2 M. Reponen,∗2 P. Schury,∗2 T. Sonoda,∗2 M. Wada,∗2 and H. Wollink∗2,∗3
High-energy radioactive isotopes have been used
in ion trap-based precision experiments after being
stopped in a large gas cell. The stopped ions of theseisotopes can be extracted from the large gas cell as alow-energy ion beam. To transport and extract theseions quickly and efficiently, electric fields are required
to guide them. In this respect, an rf-carpet (RFC)
method utilizing a dc potential gradient is a standard
technique.1) However, such a method is restricted tolonger half-life isotopes because of the transport timeowing to the upper limit on the dc gradient that canbe supported before electric discharges occur in thelarge gas cell. To study short half-life isotopes, an
RFC featuring faster transport is required. Recently,
a hybrid technique wherein the dc gradient is replaced
by a traveling potential wave was proposed, called ion
surfing.2)
Recently, we have demonstrated the transport andextraction of K+ ions using a circular RFC in 20 mbar
of He gas pressure.3) However, in a practical gas cell,
the gas pressure is higher by one order of magnitude.
In this study, the transport and extraction of K+
and Cs+ ions with the ion surfing method were tested
in high pressure He gas using a 100 mm cylinder electrode to create a push electric field Epush and a circular RFC of 80 mm diameter. In addition, we compared
the effect of an RFC of a fine pitch with one of a rough(a)(a)
pitch. (a)Thefine pitch
RFC consists of 0.08 mm wide
+V+V
+V
F FF 0.16 mm pitch and 0.32 mm diring electrodes with
ionionionionion
ion
RF-carpet
ameter orifice,whereasthe rough pitch RFC consists
F FF
RF-carpet
RF-carpetringelectrodes
ringelectrodes
ringelectrodesof 0.16 mm wide ring electrodes with 0.32 mm pitchRF:
0°0°+0°wave:
0°0°0°
0°
RF:
0°0°
wave:
RF:
+ +wave:
180°+diameterwave:
90°
and 0.64 RF:
mm
orifice.
RF:
180°
wave:
90°
RF:
180°
+ +wave:90°

two ion currents: the current reaching the RFC electrodes (with rf off), IRFC and the ion current reachinga Faraday Cup (FC), IFC . The FC was biased at −10 V
to pull ions out from the extraction orifice.
We define the combined transport and extraction efficiency as IFC /IRFC . Figure 2 shows the efficiency for
K+ and Cs+ ions with the fine pitch RFC and therough pitch RFC as functions of the He gas pressure
PHe . Above a maximum pressure, the efficiency decreases with increasing pressure because the effective
repelling force decreases because of stronger damping
effect at high He gas pressures; the push electric fieldthen exceeds the effective repelling field of the RFC
causing ions to hit the RFC. The efficiency for Cs+
is always higher than for K+ because the effective repelling force scales with the mass-to-charge ratio. The
fine pitch RFC is more efficient than the rough pitch
RFC at higher He gas pressures. This indicates thatthe effective repelling force is stronger for finer pitch
at higher He gas pressures.
We obtained an ion collection efficiency up to nearly
100% within a wide range of He gas pressures. To allow
operation at higher PHe , a larger effective repelling
force is needed.
We applied the ion surfing RFC to a superheavy
element gas cell. The results are presented elsewherein this journal4) .

p pp

p pp

(b)
(b) E
(b)

KIon
ion source
source

push

+V+V
p+V
pp

Fp Fp

Fp
Cylinderelectrode
FRF
FF
RFRF

Push
electrodePushelectrodePushelectrode
Exit oriﬁce
Exit
oriﬁceExit
nozzleExit(!0.32
oriﬁce(φ0.32mm)ExitnozzleExit
oriﬁceExit
nozzleoo

Ions

RF-carpet

F.C.
F.C.
FC
F.C.

!"#$%
!"10V

-10 V

RF-carpet
RF-carpet
RF-carpet
IRFC
IRFC
total
electrodes
ringelectrodes IRFC
electrodes
IFC
IFCringring
IFC

oo

Outer
electrodeOuterelectrodeOuterelectrodeFigure 1 illustrates the scheme used to test the efficiency of this method. The study required measuring∗2∗3

Department of Physics, University of Tsukuba
RIKEN Nishina Center
Department of Chemistry and Biochemistry, New Mexico
State University- 216 -

0.6
0.4

K+

0.2

ﬁne RFC
50

100

wave
to to
outsidewave
tooutsideoutsideIouterwave
IouterIouterFig. 1. Sketch of the transport and extraction efficiency
measurement scheme. An rf frequency of 9.3 MHz andrf amplitude of 104 Vpp are typical operating conditions.

∗1

K+

0.4

0.0

+ ionsK+Kions
+
Kions

wave
to to
insidewave
toinside
inside
wave

0.6

0.2

K ion
+sourceionsourceions
K KionsourceCs+

0.8

Efficiency

ExitnozzleExit
nozzleExit
nozzle1.0

0.8

Efficiency

RF:
0°0°
+0°wave:
180°
0°
RF:
0°0°
wave:
180°
RF:
+ +wave:
180°
RF:
180°
+ wave:
270°
RF:
180°
wave:
270°
RF:
180°
+ +wave:
270°

Cs+

1.0

RFRFRF

150

200

PHe (mbar)

250

300

0.0

rough RFC
50

100

150

200

PHe (mbar)

250

300

Fig. 2. The efficiency of K+ and Cs+ ions as a function of
the He gas pressure PHe with fine RFC (left) and rough
RFC (right).

References
1) M. Wada et al.: Nucl. Instr. Meth. B204, 570 (2003).
2) G. Bollen: Int. J. Mass Spectrom. 299, 131 (2011).
3) F. Arai et al.: Int. J. Mass Spectrom. 362,56 (2014).
4) P. Schury et al.: In this report.

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Evaluation of eﬀects of a large energy deposition on Deuterium
gaseous active target for a high-intensity ion beam injection
C.S. Lee,∗1,∗2 S. Ota,∗1 M. Takaki,∗1 Y. Kiyokawa,∗1 Y.N. Watanabe,∗2,∗3 H. Tokieda,∗1 and J. Zenihiro∗2
A deuterium gaseous active target, CNS Active Target (CAT)1,2) , has been under development for measuring the Isoscalar Giant Monopole Resonance (ISGMR)
in unstable nuclei via the (d, d’) reaction. In order toextract the ISGMR component by using the multipole
decomposition analysis, a wide angular coverage of the
distribution of the diﬀerential cross-section is required.
The CAT consists of GEM-TPC and Si detectors. In
the center-of-mass frame, the scattering angular regionof recoil particle of θCM around 2 degrees was coveredby the GEM-TPC, while the region of θCM ≥ 5 degrees was covered by the Si detectors. In the previous
experiment2) at HIMAC using a 132 Xe beam with ahigh intensity of around 1 MHz at 115-MeV/u incident energy, we experienced instabilities of the CAT; asudden jump of the current value of the ﬁeld cage and aﬂuctuation of the baseline of Si signals were observed.
The instabilities can be considered as the eﬀect of highenergy-loss density in the active gas target caused bya heavy ion beam. For evaluating of such eﬀect, webombarded the CAT with a very intense 3-MeV proton(H+ ) beam provided by a pelletron in RIKEN. In thispaper, the experiment and the results are reported.

Fig. 1. A schematic view of the setup at pelletron, RIKEN.

Figure 1 shows a schematic view of the experimental setup. The CAT was connected to the exitof the pelletron beam port with a 12-µm-thick Almylar foil. An Al ﬂange of the chamber at the exit of
the CAT was used as a Faraday Cup (FC). A copper
plate was employed to collect the charges multipliedby three thick GEMs (THGEMs) for evaluating theeﬀective gas gain. The current outputs of the FC andthe Cu plate were measured using picoammeters (ADVANTEST TR8641). The voltage and current valuesof each high-voltage supply were recorded using a multimeter (KEITHLEY 2701). Four Si detectors with aneﬀective area of 9×9 cm2 and thickness of 0.5 mm weresurrounding the ﬁeld cage. The Si signals were ampliﬁed using a preampliﬁer (mesytec MPR-32) and readout using an oscilloscope. The energy of the H+ beam
was 3 MeV, and its intensity was varied from 1 to 60
∗1
∗2
∗3

Center for Nuclear Study, The University of Tokyo
RIKEN Nishina Center
Department of Physics, The University of Tokyo- 217 -

pA. The GEM-TPC was operated at an eﬀective gas
gain of about 60 in 0.4-atm H2 .
Baseline ﬂuctuations were observed in the signalsof the Si detectors for a beam intensity of 20-pA, as
shown in the left panel in Fig. 2. This beam condition provides an energy-loss density equivalent to a132
Xe beam with an intensity of 1.2 MHz and energy
115 MeV/u. The ﬂuctuation disappeared, when, withthe same beam condition, a 10-µm-thick Al-mylar foil
was placed in front of each Si detector. Therefore, we
understand that the ﬂuctuation is possibly due to radioactive noise. At 60-pA 3-MeV H+ beam injection,
the ﬂuctuations became smaller.

Fig. 2. Preamplifier outputs of Si detectors for a 20-pA
3-MeV H+ beam injection without Al-mylar foil cover(left) and with Al-mylar foil cover (right).

Figure 3 shows the variation of current in the Cu
plate and ﬁeld cage during the 20-pA 3-MeV H+ beam
injection. The current of the ﬁeld cage increased by
4-5 µA immediately after the injection of the highintensity beam and gradually increased during thebeam irradiation. This may be explained by the effect of the initial ions from the beam and the ion backﬂow (IBF) from the THGEMs. Although the ﬁeld cage
had tripped (the current limit was 1 mA) several times,
a sudden jump of the current value seldom happened.
This may be caused by the diﬀerence between a heavyion and a light-ion, such as δ-ray creation. The eﬀectof δ-rays on both Si detectors with Al-mylar covers
and the GEM-TPC will be evaluated by using a highintensity heavy-ion beam in the near future.

Fig. 3. Current variation of the Cu plate (left) and the fieldcage (right) during a 20-pA 3-MeV H+ injection.

References
1) S. Ota et al.: CNS Annual Report 2011, CNS-REP-90(2013) 70-71.
2) S. Ota et al.: CNS Annual Report 2013, CNS-REP-93(2015) 49-50.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Design of a thin-film polarized proton target system for low-energy
RI beam experiments
E. Milman,∗1,∗3 S. Sakaguchi,∗2 S. Chebotaryov, ∗1,∗3 W. Kim,∗3 K. Tateishi,∗1 and T. Uesaka ∗1
The search for unknown resonances of unbound 10 N
via 9 C+p elastic resonant scattering is proposed. Theoretically, four broad and overlapping low-lying 10 N
resonances that may not be clearly identifiable in the
9
C+p excitation function are expected.The vector analyzing power is measured to determine these broadresonances1) . The level information obtained in theexperiment is useful for discussing resonances in 10 Li
since 10 N and 10 Li are mirror nuclei that are expected
to have a similar structure. The 10 Li structure provides us with valuable information for constructing thethree-body model of the borromean 11 Li nucleus.
A polarized target is required for the measurementof the analyzing power. A polarized proton solid target
for low-energy beam experiments2) has been designed
based on an existing system for intermediate energies
3). In the target, proton polarization is obtained bytransferring the electron polarization of photo-excitedtriplet state of pentacene to protons of p-terphenyl.
Polarization transfer is done by microwave irradiationthat satisfies the condition that the Rabi frequency ofelectron spin is matched to the Larmor frequency ofthe proton2) .
We select a magnetic field strength of 0.2 T. Thisvalue is a tradeoff between the magnitude of proton
polarization and magnetic field effect for the trajectoryof recoil particles. At this field strength, the resonancefrequency of electron spins is ∼4.8 GHz and the proton
resonance frequency is ∼8.5 MHz.
For the detection of low-energy recoil protons emitted with respect to ±22.5◦ where the analyzing poweris expected to be the largest, the microwave resonatormust be sufficiently short to avoid interference with the
trajectory of scattered protons.A three-loop two-gap
resonator4) (LGR) was chosen as the microwave resonator, as shown in Fig. 1 (Left). Its structure allows
us to sufficiently shorten the resonator and to implement NMR coil close to the resonator without affecting
its performance4) .
We conducted a simulation of the LGR using theelectromagnetic field simulation software CST Microwave Studio. In the simulation, the LGR was placed
inside a brass shield to reduce microwave radiation
losses, as shown in Fig. 1 (Right). The shield was
designed to allow beam particles and recoil protons topass through the resonator freely. The LGR was excited by an antenna placed close to one of edge loops.
The resonance frequency of LGR and the strength of
∗1
∗2
∗3

RIKEN Nishina Center
Department of Physics, Kyushu University
Department of Physics, Kyungpook National University- 218 -

Fig. 1. Three-loop two-gap resonator (LGR) (Left). LGR
placed in the shield (Right).

the oscillating microwave field were simulated at 1-W
incident power. The power required for optimal polarization transfer was evaluated. Simulations were performed for different central loop diameters. We foundthat the resonator with 18-mm diameter and 5-mm
length was the tradeoff between the target size andrequired incident power of 20 W.
The thickness of the target was chosen to be 110 µm
to cover the range of the 9 C beam with an energy of 5.6
MeV/nucleon. A novel thin crystal production method
is proposed. In this method, the crystal prepared by
the Bridgmann method is placed in a vacuum tube
and heated. The crystal sublimates and its thickness
slowly decreases. The sublimation speed is controlled
by the heater temperature. A test sample prepared by
the sublimation method is shown in Fig. 2.The sample
thickness is approximately 700 µm.

Fig. 2. Sample prepared by the sublimation method.

In conclusion, the microwave resonator was designed
for the thin-film polarized proton target at 0.2 T.
The sublimation method was proposed to produce thincrystals. In the next fiscal year, the resonator will bebuilt and tested. A thin crystal with a thickness ofapproximately ∼100 µm will be produced by the sublimation method.
References
1) T. Teranishi, S. Sakaguchi, T. Uesaka et al.: AIP Conf.
Proc. 1525, 552 (2013).
2) S. Sakaguchi et al.: Nucl. Instrum. Methods Phys. Res.
B 317, 679 (2013).
3) T. Uesaka et al.: Nucl. Instrum. Methods Phys. Res. A
526, 186 (2004).
4) R. L. Wood, W. Froncisz, J. S. Hyde: J. Magn. Reson.
58, 243 (1984).

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Kinetic parameters of photo-excited triplet state of pentacene
determined by dynamic nuclear polarization
T. Kawahara,∗1,∗2 S. Sakaguchi,∗1,∗3 K. Tateishi,∗1 T. L. Tang,∗4 and T. Uesaka∗1
A polarized proton target prepared by dynamic nuclear polarization (DNP) techniques, which is a meansof transferring electron spin polarization to nuclei by
microwave irradiation, has been extensively used inparticle and nuclear physics experiments.1) However,in these studies, DNP is carried out at a cryogenic
temperature of <4.2K and in a high magnetic ﬁeld of
several Tesla. On the other hand, DNP using photoexcited triplet states (Triplet-DNP) can produce highnuclear spin polarization without such equipment, byusing the non-equilibrated electron spin polarizationin the lowest photo-excited triplet state generated bylaser irradiation.2)
In this paper, we determined kinetic parameters of
the triplet electron spin of pentacene, which is mainly
used as a polarizing agent in Triplet-DNP, to optimize
the polarization transfer sequence for maximizing thepolarization of the target. Although the polarizationof the triplet electrons is initially higher than 70%, it
decreases as a function of time after the optical excitation. There are two processes relevant to this phenomenon: one is the decay from the triplet state to
the ground state, while the other is the relaxation to
the thermal equilibrium in the triplet state. The time
constants are referred to as lifetimes (τi , i=+1, 0, -1: irepresents the sublevels in the triplet state) and spinlattice relaxation time (T1 ).
We determined the time constants of pentacene
doped into p-terphenyl in 0.3 T and at room temperature, based on the NMR signal intensities of proton
spins enhanced by Triplet-DNP. A continuous-wave
Ar-ion laser pulsed by an optical chopper is used for optical excitation. We ﬁrst measured the delay-time (thetiming of microwave irradiation for polarization transfer) dependence (Fig. 1(a)). Analysis using only thisdata revealed a diﬃculty in separating the contributions of τi and T1 . We thus utilized the pulse-structure(the duty and the repetition rate of laser pulse) dependence data as additional information (Fig. 1(b)). The
combined analysis of these data allowed us to separate the contributions of the parameters. The values+3.0 µsof τ0 and τ± were determined to be 22.3 µs−1.5µs andµs
88 µs+13,
respectively(Fig.
1(c)).
The
value
of T1
−19 µswas found to be longer than 300 µs. It was also foundthat the proton signal enhancement is limited at a high
†
∗1
∗2
∗3
∗4

Condensed from the article in J. Phys. Soc. Jpn. 84, 044005(2015)RIKEN Nishina Center
Department of Physics, Toho University
Department of Physics, Kyushu University
Center for Nuclear Study, University of Tokyo- 219 -

D(ȫȫT)

2000(88.2 ȣV210.5 ȣV25 ȣV)(48.1 ȣV168 ȣV50 ȣV)(21.9 ȣV101.5 ȣV҄ ȣV)

1000

0

100

0

200

E
800

600

400

200

0

0

2

4

6

8

10

F
1000

800

600

2.0

min

400

200
0
15

20

25

30 60 80

100 120 102

10㸱҄

Fig. 1. (a) the delay-time dependence of the NMR signal
intensities of proton spins enhanced by Triplet-DNP. (b)the pulse-structure (the duty and the repetition rate oflaser pulse) dependence of the signal intensities. (c)Variation of the chi square values of τ0 , τ− , and T1 .

repetition rate owing to the partial cancellation of theelectron spin polarization by the remaining population
produced by the preceding laser pulses.
References
1) D. G. Crabb and W. Meyer: Annu. Rev. Nucl. Part.
Sci. 47 67 (1997).
2) T.Wakui et al.: Nucl. Instrum. Methods Phys. Res.
Sect. A 550 521 (2005).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Development of single-crystal CVD diamond detector
for time-of-flight measurements
Y. Sato,＊1 T. Shimaoka,＊2 M. Kobayashi,＊3 M. Takaki,＊3 H. Miya,＊3 M. Matsushita,＊3 S. Michimasa,＊3 K. Yako,＊3
S. Shimoura,＊3 M. Tsubota,＊2 J. H. Kaneko,＊2 H. Murakami,＊1 H. Sato,＊1 K. Yoshida,＊1 T. Kubo＊1
Production and identification techniques for radioactive
isotope (RI) beams are important for nuclear physics
experiments involving exotic nuclei that are very unstable.
RI beams are generally produced as secondary beams fromhigh-energy heavy-ion reactions using in-flight fragment
separators. In these devices, a charged-particle detector witha fast response and high radiation hardness is required tomeasure the time of flight (TOF) of ions for identifying the
RI beams in high-dose environments.
Diamond is one of the most promising materials forfabricating a charged-particle detector for performing
accurate timing measurements under high-intensity beam
conditions. Fast signals for superior timing resolution canbe obtained because of the high breakdown electrical fieldstrength and high carrier saturation velocities of the
diamond crystal. Additionally, high radiation hardness tolarge charged-particle fluxes can be expected because of thehigher displacement energy of diamond.
In this study, we fabricated a single-crystal (sc) chemicalvapor-deposited (CVD) diamond detector and evaluated the
intrinsic timing resolution of the detector. Figure 1 shows
the block diagram of the electronic circuit used forevaluating the timing resolution. Two diamond detectors
were placed in the E7B beam line at the RIKEN accelerator
facility. The detectors were fabricated using an sc-diamondof approximately 4×4 mm2. In brief, the detector has a layer
structure of Pt/sc-diamond/Ti/Au. The thickness of the
diamond crystals are 90 μm and 139 μm for the front-side
and rear-side of the detector, respectively.
8.6 MeV/nucleon-7Li beams penetrated two diamonddetectors. The pulses induced from the detector were readout using a broadband amplifier with an analog bandwidthof 1 MHz–2 GHz (CIVIDEC C2 Broadband Amplifier).
The amplifier signals were processed with a leading edge
discriminator, a time-to-amplitude-converter (TAC), and 8
k-multi-channel analyzer (MCA) for TOF measurement.
The timing resolution of the measurement system wasestimated to be 7.8 ps () using a constant time difference
generated by the fast-pulser signal and cables.
Figure 2 shows the measured TOF spectrum. The widthof the peak was estimated to be 45 ps (). The intrinsic
timing resolution of the detector was evaluated by dividing
the width of the peak by √2 and subtracting the timing
resolution of the measurement system. Here, the same
performance of the two detectors was assumed. The
intrinsic timing resolution was estimated to be 31 ps ().
RIKEN Nishina Center
Graduate School of Engineering, Hokkaido University＊3
Center for Nuclear Study, University of Tokyo＊1＊2

Fig. 1: Block diagram of the electronic circuit used in the
TOF measurement. The start signal and stop signal werecreated by output signals from the rear-side and thefront-side detector, respectively. The bias supply is left out.
The time offset of ~11 ns was created using cables. L.E.
discriminator: leading edge discriminator, TAC:
time-to-amplitude-converter, MCA: multi-channel analyzer

Fig. 2: Time of flight spectrum between two diamonddetectors. The intrinsic timing resolution (int) was
evaluated using distribution of the peak (45 ps ()) and thetiming resolution of the measurement system (7.8 ps ()).
This value is superior to the values reported by GSI: 57 ps
and 39 ps for 600 MeV/nucleon-58Ni and 1
GeV/nucleon-238U, respectively1,2). On the other hand,
NSCL/MSU achieved a resolution of ~15 ps for 87
MeV/nucleon-78Kr3).
In a future study, we will attempt to fabricate acharged-particle detector using a higher quality sc-diamondand evaluate the intrinsic timing resolution. On the other
hand, the use of a large size sc-CVD diamond (20 mm×20mm) was considered to fabricate the process for
manufacturing, large size detector.
References

1) E. Berdermann, et al.: Nuclear Physics B 78, 533 (1999).
2) E. Berdermann, et al.: XXXVI Int. Winter Meeting on Nucl.
Physics, Bormio 1998.
3) A. Stolz, et al.: Diam. Relat. Mater., 15, 807 (2006).

- 220 -

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Eﬃcient excitation of photo-excited triplet electrons of pentacene fordynamic nuclear polarization
K. Tateishi,∗1 T. Tsukihana,∗2 Y. Urata,∗2 S. Wada,∗2 and T. Uesaka∗1∗1∗2

RIKEN Nishina Center
RIKEN Center for Advanced Photonics- 221 -

(a)
TP1

M1

AP

OC1

TS1

QP1

CM

M4

LC1

Qsw1

LBO
L1

1319-nm oscillator

M5
TP2

M2
Qsw2

RT

OC2

LC2

TS2

589 nmQP2

LC2

M3 Sum-Frequency Generation

1
1
1- +- = 1319 1064
589

1064-nm oscillator(c) 10001

output power [mW]

intensity [a.u.]

(b)

0.5

0

0.6

800
0.5

600
400

0.4

200
0.3

0
-200 -1000

100 200

time [ns]pulse energy [mJ]

Dynamic Nuclear Polarization (DNP) has been successfully applied to a polarized target. DNP is a methods of transferring spin polarization from electrons to
nuclei with microwave irradiation. However, as longas electron spins in thermal equilibrium are used asa polarizing agent, cryogenic temperatures of approximately 4.2 K will be required for hyperpolarization in
the order of 10% even under strong magnetic ﬁelds ofseveral Tesla.1) One approach for overcoming the limitation is to use non-thermalized electron spins as apolarizing agent instead.
DNP using the photo-excited triplet-electron spin ofpentacene2) requires neither a cryogenic system nor asuperconducting magnet, but a laser for creating hyperpolarized electron spins. There are four important
requirements in the light source: wavelength, pulse
width, repetition rate, and output power. The wavelength aﬀects the excitation eﬃciency from the groundstate to the excited singlet state. The pulse width inﬂuences the transition eﬃciency from the excited singlet state to the triplet state. The repetition rate isrelated the initial buildup rate of 1 H spin polarization.
The output power is determined by the number of excited electrons, i.e., the sample volume.
To this end, a new laser system is developed, whichis constructed using two neodymium-doped yttrium
aluminum garnet (YAG) lasers with wavelengths of1064 nm and 1319 nm and a LiB3 O5 crystal for sumfrequency generation (Fig. 1). 3) The wavelength,
pulse width, repetition rate, and output power are
589 nm, 126 ns, 3 kHz, and 1 W, respectively. We
developed oscillators independently using laser diodepumped YAG crystals. The acousto-optic Q-switch(A/O Q-sw) was chosen to generate light pulses because of the high repetition frequency. The pulse width
can be varied by adjusting the input current of thelaser diode, and in this experiment we used ﬁnal output pulse widths of 84 and 126 ns. In order to generate
589-nm light, the infrared lights were overlapped at the
LiB3 O5 crystal. Finally, residual infrared lights wereseparated by visible-coated mirrors.
Using a single crystal of p-terphenyl doped with
deuterated pentacene4) , we carried out the DNP experiments in 0.35 T and at 300 K with laser pulses of
84 ns and 126 ns. The maximum polarization of a 84
ns laser pulse is 16% with a repetition rate of 400 Hz.
The maximum polarization of the 126 ns laser pulse
is 22% with a repetition rate of 600 Hz. The optimal
repetition rate was diﬀerent because the excited elec-

0

1000

2000

3000

repetition rate [Hz]Fig. 1. (a) Schematic view of 589-nm laser constructedwith two Nd-doped YAG lasers with wavelengths of1064 nm and 1319 nm and a LiB3 O5 crystal forsum-frequency generation. M1,M2: Oscillator mirror; Qsw1,Qsw2: A/O Qsw; TP1,TP2: Thin Plate;
LCP,LC2: Laser Chamber; RT: Rotator; OC1,OC2:
Output coupler; AP: Aperture; TS1,TS2: Telescope;
QP1,QP2: Quarter-wave plate; CM: Combiner mirror;
L1:Lens; M3,M4,M5: Mirror; LBO: LiB3 O5 crystal. (b)Pulse shape. (c) Output power (circles) and pulse energy (crosses) as a function of repetition rate.

trons play not only the role of a polarized agent but
also that of a relaxation source. When the repetition
rate was increased, the initial buildup rate increases,
but the paramagmetism acceralates spin-lattice relaxation of 1 H spins. The ﬁnal achievable polarization isdetermined by the balance of these two eﬀects. Furthermore, to obtain higher 1 H spin polarization, ourresults indicated that a longer laser pulse width to increase the initial buildup rate or a higher external magnetic ﬁeld to decrease the spin-lattice relaxation of 1 H
spins is necessary.
References
1) T. Maly et al.: J. Chem. Phys. 128 052211 (2008).
2) K. Takeda: Triplet State Dynamic Nuclear Polarization(VDM Verlag, 2009).
3) N. Saito et al.: Opt. Lett. 32 1965 (2007).
4) K. Tateishi et al.: Proc. Natl. Acad. Sci. USA 111 7527
(2014).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Realization of 1 H spin polarization of 40% at room temperature
K. Tateishi,∗1 T. Tsukihana,∗2 Y. Urata,∗2 S. Wada,∗2 and T. Uesaka∗1
Dynamic Nuclear Polarization (DNP) is a means oftransferring spin polarization from electrons to nuclei.
As a method for enhancing bulk nuclear spin polarization, DNP has been successfully applied to areas
ranging from fundamental physics to materials science,
biology, and medical science. The conventional DNP,
which is used radical as a polarizing agent, is carriedout in the strong magnetic field and at cryogenic temperature (e.g. 3.35 T and 1.4 K) to polarize electron spins in the order of 10%.1) One approach forovercoming the limitation of the experimental conditions is to use non-thermalized electron spins instead.
DNP with electron spins in the photo-excited triplet
state (triplet-DNP) can achieve hyperpolarization independent of the magnetic field strength and temperature.2) We employed pentacene as a polarizing agent,
which has an electron spin polarization of 73%, andp-terphenyl as a host material because of its stability
at room temperature and large pentacene capacity.

(a)

(b)
D

D

D

D

D

D

D

D

D

D

D

D

D
D

D

D

D

D

(c)

1H spin polarization [%]

40

30

20

10

0

References
0

5

10
time [min]15

Fig. 1. (a) pentacene-d14 . (b) p-terphenyl-2’,3’,5’,6’-d4 . (c)Polarization buildup curve. The polarizations were estimated by comparing the intensities of the hyperpolarized signals and the thermal intensities in 0.6 T atroom temperature.
∗1∗2

In this study, we focused on realizing the highest
H spin polarization at room temperature. The finallyachievable nuclear spin polarization with triplet-DNP
is determined by the balance between the spin-lattice
relaxation time of the nuclear spin (1 H in this report)
and the speed of the polarization transfer.
In order to suppress the spin-lattice relaxation
time3) , we used pentacene-d14 as the polarizing
agent (Fig. 1(a)). The triplet electrons played the roleof a polarizing agent as well as contributed to 1 H spinlattice relaxation through a perturbation of the local
field of the 1 H spins in the vicinity. In addition, we synthesized p-terphenyl-2’,3’,5’,6’-d4 (Fig. 1(b)). The 1 H
spin-lattice relaxation in p-terphenyl-h14 was mainly
due to the pendulum motion of the central benzene
ring, which modulates the local dipolar field of the 1 H
spins in and near the central ring.4)
A high-repetition-rate laser system was developed
to increase the speed of polarization transfer, and it
consists of two Neodymium-doped Yttrium Aluminum
Garnet (YAG) lasers with wavelengths of 1064 nm and1319 nm and LiB3 O5 crystal for sum-frequency generation.5) The wavelength, pulse width, repetition rate,
and output power were 589 nm, 126 ns, 3 kHz, and 1
W, respectively.
Using a single crystal of p-terphenyl-d4 doped withpentacene-d14 and the new laser, we conducted thetriplet-DNP in 0.65 T and at room temperature. The
buildup curve is shown in Fig. 1(c). 40% of 1 H spinpolarization was obtained in 15 minutes, which corresponded to the 20,000-fold enhancement under thesame conditions.
Hyperpolarization techniques using photo-excitedtriplet electrons can be used to simplify DNP experiments. The NMR sensitivity of samples that preferambient temperatures can be boosted significantly.3)
Bulk nuclear hyperpolarization in such low magnetic
fields is also desirable to achieve the polarized target for RI beams6) and the polarized filter for neutron
beams.7)
1

RIKEN Nishina Center
RIKEN Center for Advanced Photonics- 222 -

1) J. H. Ardenkjaer-Larsen et al.: Proc. Natl. Acad. Sci.
USA 100 0158 (2003).
2) K. Takeda: Triplet State Dynamic Nuclear Polarization(VDM Verlag, 2009).
3) K. Tateishi et al.: Proc. Natl. Acad. Sci. USA 111 7527
(2014).
4) K. Kahda et al.: J. Phys. Soc. Jpn. 51 3936 (1982).
5) N. Saito et al.: Opt. Lett. 32 1965 (2007).
6) T. Uesaka et al.: Phys. Rev. C 82 021602(R) (2010).
7) M. Haag et al.: Nucl. Instrum. Methods Phys. Res.,
Sect. A 678 91 (2012).

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Production of spin polarization of atoms insuperfluid helium using a pulsed Ti: sapphire laser
M. Hayasaka,＊1,＊2 T. Furukawa,＊3 H. Tomita,＊4 T. Takamatsu,＊4 K. Imamura,＊2,＊5 T. Fujita,＊6T. Kobayashi,＊7 H. Uematsu,＊1 H. Ueno,＊2 and Y. Matsuo＊8
We are developing a new laser spectroscopic technique“OROCHI” to determine nuclear spins and moments of RI
atoms. In this technique, superfluid helium (He II) is used
as a material for trapping short-lived RI atoms. We utilize
optical pumping to produce atomic spin polarization, andlaser - radio frequency (RF) /microwave double resonancemethod to investigate Zeeman and hyperfine splittings of
the RI atoms, respectively. In He II spin polarization can be
maintained for a long time (>2 s in the case of Cs),1) whichenables us to produce a high degree of spin polarization. As
for optical pumping, CW lasers are generally used to
produce spin polarization. High-repetition-rate pulsed lasers
can be superior in producing spin polarization owing to thelarge pumping rate. Using pulsed lasers, we expect toproduce spin polarization efficiently for various atomic
species that have not been spin-polarized yet. We herereport on the production of spin polarization and RF
resonance of Rb atoms in He II using a tunable pulsed Ti:
sapphire (Ti: Sa) laser operated at 1-3 kHz.
We have constructed a pulsed Ti: Sa laser with a z-shaped
cavity2) originally developed at Mainz University (see Fig.
1). The Ti: Sa laser canlase in wide range of wavelengthfrom 670 to 1050 nm3) andUV output can be easily
obtained by second harmonic generation. The Ti: Sa crystal
is pumped by a second harmonic output of a Nd: YLF laser.
The laser cavity contains four mirrors for light ofwavelength ranging from 750 to 850 nm. The tunable rangeof wavelength using a birefringent filter is 749-790 nm.For
the Rb experiment, the laser is tuned to the excitation
wavelength of Rb atoms in He II (780 nm)4). At thiswavelength the achieved output power is >150 mW at 1
kHz, and >200 mW at 2 and 3 kHz.

Fig. 1. Schematic diagram of the Ti: sapphire laser layout＊1

Department of Physics, Tokyo Gakugei University
RIKEN Nishina Center＊3
Department of Physics, Tokyo Metropolitan University＊4
Department of Quantum Engineering, Nagoya University＊5
Department of Physics, Meiji University＊6
Department of Physics, Osaka University＊7
RIKEN Center for Advanced Photonics＊8
Department of Advanced Sciences, Hosei University＊2

Fig. 2. RF resonance of 85Rb obtained by applying RF
frequency of 2.35 MHz. We can see the resonance peak at B
= 5.4(9) Gauss and peak of LIF intensity with no spinpolarization at B = 0 Gauss. The repetition rate of the pulsed
laser was 3 kHz and the output power was 7.5 mW.
Using this pulsed Ti: Sa laser, we conducted experiments
for Rb atoms in He II with optical pumping and laser-RF
double resonance method.
Figure. 2 shows laser induced fluorescence (LIF) signal
from Rb atom by the magnetic field swept from 0 to 7
Gauss. At B = 0, the LIF intensity was larger than that withmagnetic field because spin polarization of atoms was notconserved. With increasing external magnetic field, the LIF
intensity decreased due to the increase in spin polarization.
When the RF frequency is in resonance with Zeeman
splittings, the spin polarization was decreased and then LIF
intensity was increased. In Fig. 2, we can see the RF
resonance of the 85Rb Zeeman transitions in He II. These
results reveal that the produced spin polarization using
pulsed laser was sufficient to observe RF resonance clearly.
In the case of using pulsed lasers under 10 mW at 1 to 3
kHz repetition rate, we could produce comparable spinpolarization to the CW laser experiment 4) and observe RF
resonance.
In the future, we plan to use the pulsed Ti: Sa laser for
optical pumping of atomic species that have not yet been
spin-polarized and develop a technique to produce spinpolarization of various atoms. The excitation wavelength of
In atoms is 370 nm in He II5). We expect to produce spinpolarization of In atoms using a second harmonic
generation of the pulsed Ti: Sa laser.
References

1) T. Furukawa et al.:Phys. Rev. Lett. 96, 095301 (2006)
2) J. Yi et al.: Jpn. J. Appl. Phys. 42, 5066-5070 (2003)
3) K. Muramatsu.: Master Dissertation, Nagoya University (2011)4) T. Furukawa.: Doctor Dissertation, Osaka University (2007)
5) Y. Kato. Master Dissertation, Meiji University (2012)- 223 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Microwave system development of enlarged spin-polarized proton
target for RI beam experiments
S. Chebotaryov, ∗1,∗3 S. Sakaguchi, ∗1,∗2 T. Kawahara, ∗1 W. Kim, ∗3 E. Milman, ∗1,∗3 K. Tateishi, ∗1 andT. Uesaka ∗1

∗1
∗2
∗3

RIKEN Nishina Center
Department of Physics, Kyushu University
Department of Physics, Kyungpook National University- 224 -

sheet. The CuFlon sheet is rolled around a holder toform a cylindrical resonator.5) Our estimation showsthat there is a possibility to increase the efficiency of
the resonator by increasing the thickness of its copper plates from 4.4 to 36 µm, as thicker plates better
suppress radiation losses due to the skin effect.

Spin Polarization (a.u.)

A spin-polarized proton target provides opportunities to observe spin-dependent interactions in unstable nuclei. The center for Nuclear Study, Universityof Tokyo and RIKEN groups have developed a spinpolarized proton target system that is applicable to RI
beam experiments.1) The method of generating spinpolarization employed in the target system is based on
the cross-polarization technique,2) where the polarization of an electron system is transferred to protons in
the presence of a rotating magnetic field. The rotating
field is generated as a standing electromagnetic wave
using a microwave resonator.
Recently, the target system was upgraded to accomodate a target sample with a larger diameter (24mm) compared with the diameter before (14 mm).
This upgrade was carried out to increase the fraction ofbeam particles accepted by the target and to decrease
the rate of background events from the target holder.
One of the problems expected with this upgrade is thatthe standing electromagnetic wave in a large resonatoris generally weaker than that in a small one, whichmight prevent us from producing a sufficiently strong
field required for achieving optimal polarization conditions and attaining a high spin polarization.
To facilitate polarization transfer using the crosspolarization technique, electron and proton systems
have to be coupled in order for spin-exchange interaction to occur. The coupling condition h̄ωe = h̄ωI isknown as the “Hartmann–Hahn condition”3) . Here,ωe is the electron effective Larmor frequency in an
external microwave magnetic field H1 , and ωI is the
proton Larmor frequency. The electron effective Larmor frequency is proportional to the amplitude of H1 ,ωe ∝ H1 , and therefore ωe can be adjusted to match
the proton Larmor frequency. In the experiment, ωe
is tuned by changing the H1 field amplitude, which inturn is proportional to the square root
√ of the input
power supplied to the system, H1 ∝ PMW .
In the test we performed previously,4) it was foundthat the amplitude of the oscillating magnetic field
was not sufficiently high to fulfill the Hartmann–Hahn
condition. To address this problem, a redesign of theloop-gap resonator (LGR) has been attempted. LGRis the device responsible for generating a microwave
field with power PMW provided from an RF amplifier.
It is made of a sheet of CuFlon material, which consistsof a copper metal clad on both sides of a thin Teflon

600

2014
2013

400

200

0

0
1
2
3
4
√
√
Microwave Amplitude − P MW ( W )Fig. 1. Dependence of proton spin polarization signal intensity on the square root of the applied microwave power.

In Fig. 1, the closed triangles represent results ofthe present test carried out with LGR whose copper
plates are 36 µm thick. It can be √seen that saturationis reached at approximately 2.0 W of input power
where the polarization stops increasing despite the increasing input power. The presence of saturation indicates that the Hartmann–Hahn condition was fulfilled,i.e., the polarization of electrons was fully transferredto the protons. In Fig. 1 the hollow circles indicate theresults of the test carried out using LGR whose coppers plates are 4.4 µm thick. Here, the signal intensity
rises across the entire region of powers applied, whichmeans that the condition was satisfied only partially.
In summary, we designed LGR with thicker copper
plates and performed test with it. The results of thetest are promising – the Hartmann–Hahn condition issatisfied at reasonable microwave powers, which meansthat the newly constructed LGR should be suitable forapplication with enlarged target samples.
References
1) T. Wakui et al.: Nucl. Instr. Meth. Phys. Res. A 550,521 (2005).
2) A. Henstra et al.: Chem. Phys. Lett. 165, 6 (1990).
3) S. Hartmann, E. Hahn: Phys. Rev. 128, 2042 (1962).
4) S. Chebotaryov: in RIKEN Accelerator Progress ReportVol. 47, 187 (2013).
5) T. Barnard et al.: J. Magn. Reson., Ser A 120, 72(1996).

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

The oﬀ-line adjustment of the parasitic production of low-energy
RI-beam system for installation in BigRIPS
T. Sonoda,∗1 M. Wada,∗1 I. Katayama,∗1 N. Fukuda,∗1 H. Iimura,∗2 N. Inabe,∗1 T. Kubo,∗1 K. Kusaka,∗1
H. Takeda,∗1 H. Suzuki,∗1 M. Reponen,∗1 M. Wakasugi,∗1 K. Yoshida∗1 and SLOWRI collaborations
The construction of a low-energy RI-beam facility
SLOWRI1) began in 2013. The parasitic low-energy
RI-beam production system (PALIS)2) in SLOWRI
was successfully manufactured in 2014. The preliminary installation of PALIS in the second focal planechamber (F2) in BigRIPS was demonstrated. The performance evaluation of PALIS by oﬀ-line experiments
is in progress.
We will restore unused RI-beams by installing asmall gas cell in the F2 chamber in BigRIPS. This will
provide parasitic low-energy RI-beams for various precision experiments whenever BigRIPS experiments arein operation. In order to realize the parasitic beam production, there should be no interference from PALIS
in terms of BigRIPS beam tuning, detector operation
and replacement, vacuum level, etc. This year we conﬁrmed the following items whether there is no mechanical interference due to the installation of PALIS in theF2 chamber. The ﬁrst item was the ﬁtting check between the F2 chamber and PALIS which is integrated
with the F2 chamber’s roof3) . Position reproducibility was ensured by using locating guide pins equippedin PALIS. PALIS, whose weights approximately 1100kg, was carefully moved by a ﬂoor-operated crane andplaced on the F2 chamber within <1.0 mm reproducibility without any trouble. The second item wasthe applicability for the replacement of detectors used
for BigRIPS beam tuning without taking PALIS away.
There are three detectors, i.e., two PPACs and one
plastic scintillator inside the F2 chamber, they need
to be occasionally replaced for maintenance. By using two maintenance windows equipped in PALIS, we
conﬁrmed that these detectors were able to be put inor out. The third item was the vacuum level for theF2 chamber together with PALIS. After several hoursof pumping, the pressure in the F2 chamber was 10−4
Pa, the same as in conventional operation. Fig. 1 shows
the photographs during the installation test of PALIS
in the F2 chamber in BigRIPS.
The oﬀ-line experiment was started for the performance evaluation of PALIS. A new diﬀerential pumping method was implemented in PALIS from the resultof a prototype system4) . The diﬀerential pumping region is devided into four sections. The capability ofdiﬀerential pumping was veriﬁed; a pressure diﬀerence
from approximately 105 Pa argon or helium in the gas
cell down to 10−4 Pa in the ﬁnal section was achieved,
while using a 2 mm diameter gas cell exit hole.
∗1∗2

RIKEN Nishina Center
Japan Atomic Energy Agency- 225 -

PALIS
PALIS

Gas
Gas cell
cell
SLIT
SLIT

BigRIPSBigRIPS F2
F2 chamberchamberFig. 1. The upper photo shows the entire PALIS integrated
with the F2 chamber’s roof. The lower photo is the gas
cell part in PALIS.
Pressure(Pa)
Pressure (Pa)
10
1055

Argon
gas
Argon gas

101033

HeliumHelium gas
gas

10
1011
-1
10
10-1
-3
10
10-3

Differential
pumping region
region (70cm)(70cm)
Differential pumping

Section1
Section1

Gas
cell
Gas cell(exit
2mm)(exit hole
hole 2mm)

Section3
Section3

Section2
Section2

Place
Place

Section4
Section4

Fig. 2. Capability of diﬀerential pumping in PALIS.

We plan to start on-line commissioning experiments
in 2015.
References
1) M. Wada et al., Hyp. Int. 199 (2011) 269.
2) T. Sonoda et al. APS Conf. Proc. 1104 (2009) 132.
3) T. Sonoda et al. ARIS2014 proceedings to be published.
4) T. Sonoda et al.: Nucl. Inst. and Meth. B295 1(2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Current status of the gas cell ion beam cooler-buncher at SLOWRI
Y. Ito,∗1 F. Arai,∗1,∗2 I. Katayama,∗1 M. Reponen,∗1 P. Schury,∗1 T. Sonoda,∗1 M. Wada,∗1 and H. Wollnik∗1,∗3

Efficiency

1.0
0.8
0.6

K+
fRF = 9.3 MHz
VRF = 112 Vpp
fAF = 70 kHz(vion ~ 90 m/s)
1.0

1.5

2.0

2.5

3.0

3.5

PHe (mbar)

Epush (V/cm)
5
10
15

4.0

4.5

102

Acetylcellulose
d = 1.22-1.34 g/cm3

101

15

20

25

Incident Energy (keV)

30

10

15

20

25

Incident Energy (keV)

30

Fig. 2. Ranges as a function of the incident energy of an
incoming ion beam for several elements with both SiN
and Acetylcellulose membranes. The bands describe
the range straggling in ±1σ and the dashed lines indicate the minimum thicknesses for each material.

5.0

Fig. 1. Transport and extraction efficiency as a function of
the He gas pressure for several Epush values.

As shown in Fig. 1, at He gas pressures higher than
2 mbar, efficiencies of ≈100% were obtained for a wide
∗3

Na
K
Rb
Cs

Si3N4

d = 3.44 g/cm3

10

0.2

∗2

Si3N4

101

0.4

∗1

102

Range (nm)

1.2

0.0

range of push electric field strengths. For an even lower
gas pressure, such as 1 mbar, the efficiency slightly decreased; efficiencies of more than 60% were achieved
even with the highest push electric field strengths.
Compared to the efficiency of 22% seen with a finepitch RFC at 5 mbar, a rougher pitch can be expected
to make the GCCB highly efficient.
Another concern was the injection of a 30 keV beam
into the gas cell. The gas cell has no window to transport the low-energy ion beam, and thus all elements
can be injected into the gas cell. However the incoming beam might be scattered due to the leak gas aroundthe entrance. As a complementary idea, we are considering using nm-thick windows for the entrance. One
option is a SiN membrane and the other is a Acetylcellulose membrane. The minimum thicknesses of SiN
and Acetylcellulose membranes are 10 nm with 5×5mm2 area and 10 nm with ∼10 mm diameter, respectively. The ranges for both windows were calculated by
the SRIM code as shown in Fig. 2. In both cases, theranges at 30 keV for the elements as heavy as Cs arelarger than the minimum thicknesses, indicating thations can penetrate the windows. Because the residual
ion energy after the window will be much lower than
the windowless case, the size of the gas cell can bemuch smaller, i.e., total length of <100 mm.

Range (nm)Conversion of a continuous ion beam to a pulsed
ion beam will be an essential process for various precision experiments at the SLOWRI facility1) . Continuous ion beams from SLOWRI gas cells can be stopped
and provided as low-emittance pulsed ion beams witha gas cell ion beam cooler-buncher (GCCB)2) . The
GCCB consists of a gas cell with an RF carpet (RFC),
an RF quadrupole ion guide, and a flat trap3) . Ion
beams of energy as high as 30 keV will be injected intoa low-pressure He gas cell, and then decelerated andthermalized solely by gas collisions. The ions will thenbe efficiently transported by the RFC and the RFQ ion
guide to the flat trap, and then bunched and cooled.
In this process, there was a concern regarding theperformance of the RF carpet at such unusually low
pressure – as low as 2 mbar. Simulations indicatedthat a rough-pitch RFC could transport ions more efficiently than a fine-pitch RFC4) . The transport andextraction efficiency was investigated experimentallyusing an RFC with a pitch of 0.32 mm and an exit holewith a diameter of 0.64 mm with K+ ions. Here thepitch was twice as large as the fine-pitch RFC used inhigh pressure gas cells. The experimental parameters
were optimized to achieve a high efficiency (describedin Fig. 1), which is defined as the ratio of the ion current leaving the exit hole measured by a Faraday cup
placed after the RFC to the ion current measured on
the RFC electrodes when the RF and AF voltages areturned off.

RIKEN Nishina Center
Department of Physics University of Tsukuba
Department of Chemistry and Biochemistry, New Mexico
State University- 226 -A performance test of these windows, i.e., a stresstest for the pressure difference and the heat cycle between the room temperature and cryogenic temperature, will be performed soon. Using a 30 keV ion beamof stable nuclei, the overall efficiency of the GCCB withand without a window will be evaluated in FY2015.
References
1) M. Wada et al., Nucl. Instr. Meth. B 204, 570 (2003)
2) Y. Ito et al., JPS Conf. Proc. 6 (2015) (in press)
3) Y. Ito et al., Nucl. Instr. Meth. B 317, 544 (2013)
4) Y. Ito et al., RIKEN Accl. Prog. Rep. 47, 205 (2013)

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

SCRIT luminosity monitor
S. Yoneyama,∗1,∗2 A. Enokizono,∗1,∗3 K. Kurita,∗1,∗3 S. Matsuo,∗1,∗3 Y. Moriya,∗1,∗2 T. Ohnishi,∗1 T. Suda,∗1,∗2
T. Tamae,∗1,∗2 R. Toba,∗1,∗4 M. Togasaki,∗1,∗3 K. Tsukada,∗1,∗2 T. Tsuru,∗1,∗2 M. Wakasugi,∗1
and K. Yamada ∗1,∗3
A luminosity monitor has been newly constructed
and installed at the SCRIT electron scattering facility1,2) . This monitor measures the number ofbremsstrahlung photons produced by collisions between an electron beam and the target short-lived nuclei trapped in the SCRIT device. Using known abremsstrahlung cross section, one can determine thecollision luminosity on-line.
The monitor consists of a position detector anda calorimeter as shown in Fig.
1.
The position detector measures the spatial distribution of thebremsstrahlung photons, and the calorimeter measures
their energies. The position detector consists of two
identical X- and Y-detectors, each of which has 16 optically isolated scintillating fibers of 3 × 3 mm2 crosssection. The scintillating fibers are coupled to a 4 ×
4 multi-anode photomultiplier. The calorimeter consists of seven optically isolated pure-CsI crystals, eachof which is 20 cm long with a hexagonal cross section
with 4 cm sides.
In order to define the angular acceptance of thedetector for the bremsstrahlung process, a large Pb
block, 300 (h) x 300 (w) x 50 (t) mm3 , with a holeof 50 mm ϕ is placed in front of the monitor for collimation of bremsstrahlung photons. Note that thebremsstrahlung photons enters the center crystal of thecalorimeter. The luminosity monitor is placed ∼670
cm downstream from the center of the SCRIT device.
Figure 2 shows the spatial distributions ofbremsstrahlung photons, whose energy is larger than
50 MeV. The stored electron beam energies were 150
and 300 MeV, and typical stored currents were 250 mA
for both energies.

20

Ca

lor

cm

4 cm

ime

ter

4.8 cm5 cmΦ

Position detector

Non-identical shapes observed for X and Y distributions should be attributed to the asymmetricmaterial distributions of the storage ring along thebeam axis, where the bremsstrahlung photons travel
through. GEANT4 simulations are performed by taking the material distributions precisely into account as
possibly, and the simulation results are found to reproduce the measured spatial distributions reasonably
well. In addition, the measured energy distributionsof the bremsstrahlung is also well accounted for by thesimulation. Assuming that the trapped residual gases
are purely oxygen, the collision luminosities are determined as L = 2.34 ± 0.09 cm−2 s−1 and 17.2 ± 0.69
cm−2 s−1 , respectively3) .

Fig. 2. X and Y distributions for Ee = 150 and 300 MeV

During the luminosity measurements mentioned
above, elastically scattered electrons from the trapped
residual gases were measured simultaneously using a
newly installed high-resolution large-acceptance magnetic spectrometer, WiSES (Window-frame Spectrometer for Electron Scattering)4) . As the elastic scattering cross section for oxygen is also well known, thecollision luminosity will be independently determinedfrom the elastic scattering events soon, and the results
should be compared with that determined by the luminosity monitor.
References

Fig. 1. Bremsstrahlung Luminosity Monitor.
∗1
∗2
∗3
∗4

RIKEN Nishina Center
ELPH, Tohoku University
Department of Physics, Rikkyo University
Department of Electrical Engineering, Nagaoka Universityof Technology- 227 -

1) M. Wakasugi et al. Nucl. Instrum. and Method B317,(2013) 668.
2) T. Suda et al. Prog. Theor. Exp. Phys. 03C008, (2012)3) S. Yoneyama, Master thesis (in Japanese), (2014) Tohoku University.
4) K. Tsukada et al., in this report.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Study of the performance of the SCRIT rear drift chamber
S. Matsuo,∗1,∗2 A. Enokizono,∗1,∗2 K. Kurita,∗1,∗2 Y. Moriya,∗2,∗3 T. Suda,∗2,∗3 T. Tamae,∗2,∗3 K. Tsukada,∗2,∗3
T. Tsuru,∗2,∗3 and S. Yoneyama∗2,∗3
The SCRIT electron spectrometer called WiSES(Window-frame Spectrometer for Electron Scattering)consists of a dipole magnet, front and rear drift chambers (FDC and RDC, respectively), a helium bag to
reduce multiple scattering and plastic scintillators forevent triggering. To obtain charge density distributions of unstable nuclei, the angular distributions ofdifferential cross sections have to be precisely measured
using elastic electron scattering. Thus, the WiSES
is required to achieve a good momentum resolution(∆p/p ≈ 10−3 ) for a wide momentum range1) , and theposition resolution of the RDC is required to be ∼150
µm to achieve the momentum resolution. A newly developed electronics module (RAINER) is employed toread data for the RDC2) . In this article, we report
performances of the RDC and RAINERs, which were
examined using a tungsten wire target experiment in
December 20143) .
Since the RDC and RAINERs are installed very
close to the RF power source for the electron storage ring, the background noise effect must be carefully
investigated. Although the RF noise test has been performed using a small prototype DC with RP1212 (anold version of RAINER) which showed a good performance4) , the actual RF effect on the RDC is still
uncertain. Therefore, we repeated the same RF noise
test using the RDC and RAINERs prior to the wire
target experiment. As shown in Fig. 1 (a), the noiselevel was found to be slightly larger than that observedin the previous report but still less than ∼800 mV in
the worse case. Fig. 1 (b) shows the comparison ofnoise counts between the RF off and on cases as afunction of the threshold voltage (Vth ) for the ASD

chip in RAINER. There is basically no difference in thenoise rate for the RF on/off conditions at Vth > 800
mV, and the rate reduces to zero for Vth > 2200 mV.
For the wire target experiment, Vth is set to 1500 mV,
where the noise rate is still much smaller than the event
rate (a few hundred hertz) and such a low-rate random
background could be eliminated in the tracking.
The RDC consists of 10 layers as VV′ UU′ XX′ VV′ UU′
and the tracking is performed using the following iterative algorithm. First, the U and V planes are determined using the hit position information for every
four layers. Here, the initial hit position in each cell is
calculated using TDC and a roughly estimated x − t(space-time) calibration parameter. Second, a track is
determined by combining the V/U planes and the hit
positions in the remaining two X layers by minimizing
χ2 /ndf. Then, the residual distributions between theinitial hit positions and the track intersection on thelayer planes and the x − t calibration parameters are
re-evaluated for each layer. The procedure is iterated(typically 4-5 times) until the widths of the residual
distributions converge to the minima. The position
resolution and efficiency per layer of the RDC were
determined from the wire-target experimental data.
Fig. 2 shows the converged residual distribution for agiven V layer without the hit information of the layer.
The rms was found to be ∼200 µm.
In summary, we conducted a wire target experimentfor SCRIT WiSES and obtained calibration parameters for the RDC. Some efforts to improve the tracking
algorithm are underway by tuning the calibration parameters to obtain a better position resolution.

Fig. 2. Residual distribution of a V layer of the RDC
Fig. 1. (a) RF noise level measured at the ASD chip in the
RAINER card. (b) Noise count rates as a function ofVth with/without RF power.
∗1
∗2
∗3

Department of Physics, Rikkyo University
RIKEN Nishina Center
Research Center for Electron-Photon Science, Tohoku University- 228 -

References
1) T. Suda et al.: Prog. Theor. Exp. Phys. 03C, 008 (2012)
2) A. Enokizono et al.: in this progress report.
3) K. Tsukada et al.: in this progress report.
4) S. Matsuo et al.: Accel. Prog. Rep. 47, 198 (2014)

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Current status of RI beam production at electron-beam-driven RI
separator for SCRIT (ERIS)
T. Ohnishi,∗1 S. Ichikawa,∗1 M. Togasaki,∗1,∗2 K. Kurita,∗1,∗2 and M. Wakasugi∗1
ERIS (electron-beam-driven RI separator for SCRIT) consists of an RI generator, a FEBIAD-type ion
source, and an RI separator. The photoﬁssion of uranium driven by an electron beam is used for RI production in ERIS. Details of ERIS were reported in Ref .
2. During the present year, we improved the releaseeﬃciency including the eﬃciency of release from theproduction target and that of transport from the target to the ionization chamber. In this paper, we report
improvements and the present status of ERIS.
One of the improvements is the stable supply of a
1-mm uranium carbide target disk. Using a 1-mm target disk, the eﬃciency of release from the production
target is expected to increase, because the total surface area of target disks becomes larger than in thecase of 2-mm target disks used in the previous test3) .
Uranium carbide is obtained by the carbothermal reduction of uranium oxide in presence of carbon. Details of constructing the target were presented in Ref .
3. In order to construct a thin disk, the careful selection of the graphite grain size is required for theprocess of constructing a disk from graphite powder.
Furthermore, the uranium-oxide-coated graphite powder is also needed to construct a disk without a binder.
These requirements are aimed at reducing the vacancy
inside the disk and the crack at the edge of the disk.
The obtained disk was approximately 1 mm in a thickness and 18 mm in a diameter. In total, 23 disks wereprepared. The total amount of uranium was about 15
g, and the average mass concentration of uranium inthe disk was estimated as 3.4 g/cm3 .
Another improvement involved strengthening theheat shield. In particluar, the heat shield of the transfer tube located between the target and the ionizationchamber was increased in order to ensure no cold spots
were present.
After these improvements, the uranium-carbide
disks were irradiated with an electron beam accelerated to 150 MeV. The electron beam power was nearly
10 W. Tantalum disks with a thickness of 5 mm and adiameter of 20 mm were inserted in front of the production target to increase the production of γ rays. The
temperature of the target and the transfer tube wasapproximately 2000 ◦ C. The produced RIs were accelerated to 20 kV and mass-separated by the analyzing
magnet. They were identiﬁed by the measurement ofγ rays corresponding to the decay of the RIs using a
Ge detector.
Figure 1 shows the rate of Sn and Xe isotopes at
1)

∗1
∗2

RIKEN Nishina Center
Department of Physics, Rikkyo University- 229 -

the Ge detector. These rates are estimated from theobserved γ-ray yield using the eﬃciency of the Ge detector and the half-life of each isotope. The overall eﬃciency is the ratio of the observed rate to the expected
production rate inside the target. This eﬃciency includes the eﬃciency of release from the target, ionization in the ion source, and eﬃciency of transport fromthe ion source to the detector. The overall eﬃciency ofstable xenon with a calibrated gas ﬂow was also measured during the experiment. Because stable xenon
was introduced into the ionization chamber througha gas inlet, the measured overall eﬃciency of stablexenon includes only ionization and transport eﬃciencies. In the case of tin isotopes, the same ionizationand transport eﬃciency as those of xenon can be used,which is supported by the results at ALTO4) . As aresult, the release eﬃciency of xenon and tin isotopes
can be estimated. Table 1 shows the summary of rateand eﬃciency in the case of 137 Xe and 132 Sn. Compared with the previous results3) , the release eﬃciencies of 137 Xe and 132 Sn become almost nine and six
times larger, respectively. Furthermore, the overall efﬁciency of 132 Sn at ERIS is achieved at same level as
ALTO4) . Further studies are in progress in order torealize the electron elastic scattering experiment with
RI.

Fig. 1. Rate of Sn and Xe isotopes at the particle identiﬁcation detector at ERIS. The electron beam power was
almost 10 W. Total amount of uranium is 15g.
Table 1. Summary of rate and eﬃciency with 10-W beam
137
132
Xe
Sn
6
Observed rate (atoms/s)
6.4×10
2.6×105
Expected rate (atoms/s)
7.5×107 1.3×107
Overall eﬃciency
8.4%
2.1%
Overall eﬃciency of stable xenon
14%
15%
Release eﬃciency
61%
14%

References
1) M. Wakasugi et. al: Nucl. Instr. Meth. B317, 668(2013).
2) T. Ohnishi et. al: Nucl. Instr. Meth. B317, 357(2013).
3) T. Ohnishi et. al: RIKEN Accel. Prog. Rep. 47, ?(2014).
4) M. Cheikh Mhamed et. al: Nucl. Instr. Meth. B266,
4092(2008).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Development of the readout system for SCRIT WiSES
A. Enokizono,∗1,∗2 H. Baba,∗2 Y. Haki,∗3 K. Kurita,∗1,∗2 S. Matsuo,∗1,∗2 Y. Moriya,∗2,∗4 T. Suda,∗2,∗4
T. Tamae,∗2,∗4 K. Tsukada,∗2,∗4 T. Tsuru∗2,∗4 and S. Yoneyama∗2,∗4
WiSES (Window-frame Spectrometer for Electron
Scattering) has been developed for SCRIT experiments
in order to achieve the world’s first measurement of
the detailed structures of unstable nuclei using electron elastic scattering1) . A detailed description of the
WiSES apparatus is reported elsewhere2) . One of the
key components of WiSES is the Rear Drift Chamber(RDC) and the readout module (RAINER). In December 2014, all WiSES components including RDC and
RAINERs have been installed for a wire target experiment, and the performance has been measured3)4) . In
this report, the setup of RDC and the WiSES readout
system for the wire target experiment is described.
RDC has a volume of 274 cm x 36 cm x 78 cm
and consists of 10 layers as UU′ VV′ XX′ UU′ VV′ madeout of 1002 sense wires (20 µm Au-W) and 3026 field
wires (80 µm Au-Al). Each drift cell has a hexagonal
shape with each side measuring 1 cm, and He + CH4(50:50) gas is used with an operation voltage of 2.95
kV. During the performance measurement and burn-in
test for a year, 2 field wires of the U and V layers had
a high current problem and have been replaced. We
have found no hot/dead channel and experienced no
HV trip throughout the wire target experiment.
Figure 1 shows RAINER which is a general multipurpose readout card (15 cm x 20 cm) manufactured by
REPIC and is capable of processing ADC and TDC for
64 independent channels. TDC is counted by FPGA
with the timing resolution of ∼1 ns with an 8 µs ringbuffer. One of the advantages of using RAINER is
the reduction of analog background noises by digitizing the signal at FPGA and the data is sent on

TCP. This is beneficial for RDC which is installed near
SCRIT SR2’s RF power source. An RF noise test has
been performed and reported elsewhere4) . 16 cards
are mounted on RDC to read all 1002 channels andthe data is sent to a DAQ PC via Ethernet cables witha Gigabit switching hub. It has two data write modes,
i.e. RAW mode and zero suppression mode to help in
speeding up the DAQ rate.
As shown in Figure 2, two plastic scintillators are
installed for triggering events and veto scintillators arealso placed to remove cosmic events and backgroundfrom the SR2 ring. TDC data for FDC are obtainedwith AMT-VME and the data is sent to the same DAQ
PC as one for RAINERs. RIBFDAQ5) (Babirl and
ANAROOT) are used as the DAQ and online monitoring softwares. 16 RAINER data and VME data
are taken by independent 17 processes using only one
DAQ PC including the event builder. The DAQ performance test shows that there is no event loss up toa few kHz in the zero suppression mode. This is sufficient considering our trigger rate which is typically a
few hundreds Hz including backgrounds.
In summary, SCRIT WiSES and the readout systemhave been developed and operated smoothly for thewire target experiment, except for a few minor issues.
More studies and improvements of the DAQ system
are underway toward the first electron-132 Sn scatteringexperiment at SCRIT in 2015.

Fig. 2. Appearance of WiSES setup at SCRIT experiment.

References

Fig. 1. RAINER card
∗1
∗2
∗3
∗4

Department of Physics, Rikkyo University
RIKEN Nishina Center
REPIC Corporation
Research Center for Electron-Photon Science, Tohoku University- 230 -

1) M. Wakasugi et al.: NIM B317, 668 (2013).
2) T. Suda et al.: Prog. Theor. Exp. Phys. 03C008 (2012).
3) K. Tsukada et al.: in this progress report.
4) S. Matsuo et al.: in this progress report.
5) H. Baba et al.: NIM A616, 65 (2010).

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

New fast-kicker system for Rare RI Ring
Y. Yamaguchi,∗1 H. Miura,∗1,∗2 Y. Abe,∗1,∗3 and M. Wakasugi∗1
We are developing a new fast-kicker system for Rare
RI Ring. Figure 1 shows the block diagram of the new
fast-kicker system. It primarily consists of a thyratron
Kicker magnet
12.5Ω
Charger
75kV

PFN 12.5Ω(adjustable)

Coaxial Cable
5m, 12.5Ω

Thyratronswitch
HV unitThyratron
Grid pulser

Coaxial Cable
15m, 12.5Ω

Dicharge trigger
for extraction(adjustable)
Control unit

Matching
resistor
12.5Ω(adjusable)

Discharge trigger
for injection

Fig. 2. PFN charging waveform for injection/extraction.
Fig. 1. Block diagram of the new fast-kicker system.

∗1
∗2
∗3

RIKEN Nishina Center
Department of Physics, Saitama University
Institute of Physics, University of Tsukuba- 231 -

We fabricated a prototype twin kicker magnet toinvestigate the magnetic field by using a single-turnlong search coil. Figure 3 shows the waveform of themagnetic field. Owing to the faster response time,

Magnetic field [G]switch, a charger coupled with a pulse forming network(PFN), a kicker magnet, a matching resistor, and acontrol section of the discharge trigger. The thyratron
is a deuterium-filled three-gap ceramic CX1171, which
was assembled by e2v technologies. The kicker magnet
is a distributed constant type magnet with a characteristic impedance of 12.5 Ω. We use a new substrateof the thyratron grid pulser on the basis of a previous feasibility study1) to shorten the response time. In
addition, we adopt a fast-charger named the hybrid
charging system2) to reduce the recharging time.
The new substrate of the thyratron grid pulser ismainly composed of four FET drivers, four MOSFETs, and four pulse transformers (PTs). Here, theresponse time refers to the interval between the timeof input of the discharge trigger signal and the time of
10 % of the thyratron current output. The responsetime steadies at around 250 ns when the charging voltage becomes 25 kV or more.
The hybrid charging system, which consists of amain charging part and a sub-charging part, is indispensable for extracting a particle from the ringin 700 µs using the same kicker magnet. The main
charge (90 %) is achieved in about 0.1 ms using adouble forward converter composed of IGBTs and a
PT. After the main charging process is completed,the sub-charging process is immediately started. The
sub-charge is completed within 0.1 ms using a highfrequency (500 kHz) resonant circuit and a PT. In addition, a high-precision voltage divider, which connects
to the sub-part coupled with a comparator, can be
maintained at a constant charging voltage level within
the range of fluctuation of less than ± 1 %. Figure 2
indicates an example of the PFN charging waveform
for injection/extraction.






465 ns









Triggerin          
Time [ns]

Fig. 3. Waveform of the magnetic field at the charging voltage Vc = 25 kV.

the propagation time from a trigger signal input tothe power supply until the flattop center of the kicker
magnetic field is about 465 ns. On the other hand,the shape of the flat-top part and the tail-part of the
waveform does not satisfy our requirements. The fluctuation of the flat-top, which is defined as ±80 ns of
the flat-top center, should be maintained at less than
±3%, and we want to restrict it to less than 0 ± 1%
for the region after 355 ns (for 200 MeV/u) from theflat-top center. Therefore, we are trying to reduce thedisturbance of the waveform.
References
1) Y. Yamaguchi et al.: RIKEN Accel. Prog. Rep. 44, 157(2011).
2) Y. Yamaguchi et al.: RIKEN Accel. Prog. Rep. 46, 166(2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Status of the resonant Schottky pick-up for the Rare RI Ring project
F. Suzaki,∗1,∗2 Y. Abe,∗1,∗3 S. Naimi,∗1 A. Ozawa,∗3 T. Suzuki,∗2 T. Uesaka,∗1 M. Wakasugi,∗1 K. Yamada,∗1
T. Yamaguchi,∗2 Y. Yamaguchi,∗1 J. Zenihiro,∗1 and Rare-RI Ring collaboration
Precise mass measurements of rare RI make a substantial contribution to the study of nucleosynthesis
and nuclear structure. Rare RI Ring is an isochronous
storage ring for precision mass measurements of rare RI
1,2). The Rare RI Ring allows us to determine masses
with a precision of 10−6 . For such high precision measurement, it is essential to maintain the isochronous
condition at 10−6 . We are interested in neutron-richnuclei that have short lifetimes and low production
rates. To measure such nuclei, we adopted the individual injection technique, in which a single particle isinjected to the ring and stored.
Resonant Schottky pick-up is a beam diagnostic device which can detect non-destructively the signal froma particle passing through the resonant cavity at theresonance frequency, fres . With the resonant Schottky
pick-up we acquire revolution frequencies of nuclei circulating in the ring. The distribution of the revolution
frequency corresponds to the distribution of the momentum of nuclei. We adopted the resonant Schottky
pick-up as a monitor for tuning the isochronous ﬁeld
in the ring. Similar resonant Schottky pick-ups havebeen used for the same purpose at GSI3) in Germany
and IMP4) in China.
We performed the oﬄine performance test of theresonant cavity with a network analyzer5) . From themeasurements, fres = 171.43 MHz, shunt impedance
Rsh = 161 kΩ, unloaded quality factor Q0 = 1880,
and Rsh /Q0 = 86 Ω were obtained. With results of
the oﬄine test, the output signal power corresponding
to a single ion with charge q at resonance3) is estimated to be P = q 2 × 2.7 × 10−21 W and the power ofthermal noise Pnoise is estimated to be 7.1 × 10−19 W.
For q ≥ 17, the signal from a single particle could be
detected by the present Schottky pick-up.
We have started new oﬄine test to investigate thesensitivity of the resonant Schottky pick-up. We developed a test system using the electron beam generated
by an electron gun. Figure 1 shows the schematic viewof the setup. We used a Ta ﬁlament cathode. A gridis connected to a function generator. With the output
coupler, we detect the induced electromagnetic wave
inside the resonant cavity at the resonance frequency.
Usually, we obtain a DC electron beam when thermal
electrons are accelerated. However, the DC electron
beam does not induce the alternative electromagnetic
ﬁeld in the resonant cavity. Therefore, we add a frequency modulation at the desired frequency and am∗1
∗2
∗3

RIKEN Nishina Center
Department of Physics, Saitama University
Institute of Physics, University of Tsukuba- 232 -

plitude into the grid. The modulated frequency is set
to the resonance frequency. This simulates the ion circulation in the storage ring at the frequency. Changing
the amplitude of the modulation controls the ion beam
current. Therefore, we quantitatively evaluate the sensitivity of the resonant Schottky pick-up. The resultsof the test will be reported in coming publications.

CavityCathodeRF
Function
generator

Grid

Faradaycup

Outputcoupler
RSA

Fig. 1. Schematic view of the oﬄine test using an electron
beam. To induce an alternative electromagnetic ﬁeld
inside the resonant cavity, we use the grid to modulate the DC electron beam at the resonance frequency.
Therefore alternative electromagnetic ﬁelds are induced
by electrons passing through the resonant cavity. We
detect the induced signals with a real time spectrum
analyzer (RSA).

References
1) Y. Yamaguchi et al.: Nucl. Instrum. Methods. Phys.
Res. B 317 (2013) 629.
2) A. Ozawa et al.: Prog. Theor. Exp. Phys. 2012 Issue 1(2012) 03C009.
3) F. Nolden et al.: Nucl. Instrum. Methods. Phys. Res. A
659 (2011) 69.
4) J. X. Wu et al.: Nucl. Instrum. Methods. Phys. Res. B
317 (2013) 623.
5) F. Suzaki et al.: JPS. Conf. Proc. (ARIS2014) in press.

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Extraction of multi-nucleon transfer reaction products in 136 Xe and198
Pt systems
Y. Hirayama,∗1 H. Ishiyama,∗1 S.C. Jeong,∗1 H. Miyatake,∗1 M. Oyaizu,∗1 Y.X. Watanabe,∗1
N. Imai,∗2 M. Mukai,∗3 S. Kimura,∗3 Y.H. Kim,∗4 M. Wada,∗5 T. Sonoda,∗5 P. Van Duppen,∗6
Yu. Kudryavtsev,∗6 and M. Huyse∗6

∗1
∗2
∗3
∗4
∗5
∗6

Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK)
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tsukuba
Department of Physics, Seoul National University
RIKEN Nishina Center
Instituut voor Kern-en Stralingsfysica, KU Leuven- 233 -

−2

Extraction efficiency

10

−3

10

−4

10

0

5
136

10

15

20

25

Xe beam intensity ( pnA )Fig. 1. Extraction eﬃciency of 198 PtAr2 molecular ions
measured as a function of the 136 Xe beam intensity.

ionized 199 Pt (t1/2 = 30.8(2) min) atoms that mainly
formed 199 PtAr2 molecular ions like 198 Pt did. Figure
2 shows the measured lifetime when 199 PtAr2 molecular ions are used. The measured lifetime t1/2 = 33(4)min was in good agreement with the reported value.
Thus, the molecular formation does not aﬀect the lifetime measurement of unstable nuclei.
Considering the production rates of nuclei aroundN = 126 calculated by the GRAZING code1) , we canmeasure 12 new lifetimes with an eﬃciency of 0.1%,
beam purity of > 99.7%, and a primary beam intensityof 20 pnA. To extend this study to more neutron-richnuclei, we have been developing a new sextupole ion
guide with a large angular acceptance for increasing
the extraction eﬃciency.
1600

Beta-ray counts

We have developed the KEK Isotope Separation System (KISS) to study the β-decay properties of theneutron-rich isotopes with neutron numbers aroundN = 126 for astrophysics research1–3) . In the KISS,a gas cell ﬁlled with argon gas at a pressure of 50 kPa,
in which nuclei produced by multi-nucleon transfer reactions are to be stopped and collected, is essential
equipment for selectively extracting the isotope of interest by using a resonant ionization technique. Using
the elastic events of 198 Pt in the 136 Xe beam and 198 Pt
target system, we evaluated the absolute extraction efﬁciency and beam purity of the KISS gas cell system.
We successfully measured the lifetime of the unstable
nucleus of 199 Pt extracted from the KISS.
We performed on-line tests using the 136 Xe beamwith an energy of 10.75 MeV/nucleon and a maximum
intensity of 20 pnA. The 136 Xe beam was directed onto
the 198 Pt target placed in the gas cell, and was stopped
at a tungsten beam dumper after passing through thegas cell. The thermalized and neutralized 198,199 Pt
atoms of the reaction products were re-ionized in thegas cell, and the ions were extracted and detected after
mass separation by using a Channeltron detector forion counting. The lifetime of 199 Pt was measured byusing β-ray telescopes newly installed at the E3 experimental hall4) .
We successfully extracted laser-ionized 198 Pt atoms
emitted from the target by elastic scattering. However,the 198 Pt ions formed molecular ions such as 198 PtH2 ,198
PtH2 O, and 198 PtAr2 with the intensity ratio of
1, 1, and 6, respectively, relative to the intensity of198
Pt ions. Figure 1 shows the measured extraction
eﬃciency of the 198 PtAr2 molecular ions (A = 278) asa function of the primary beam intensity. The extraction eﬃciency was deﬁned as a ratio of the number of198
PtAr2 ions detected to the number of 198 Pt atoms
emitted from the target by elastic scattering (17 barn).
The measured eﬃciency of about 0.20% was observed
to be independent of the primary beam intensity, as
shown in Fig. 1, owing to the bend structure of thegas cell. The obtained beam purity was > 99.7% at
the maximum primary beam intensity of 20 pnA.
After the extraction of 198 Pt, we extracted laser-

1200
800
400
0

0

20

40

60

80

100

Time (min)Fig. 2. Lifetime measurement of 199 Pt.

References
1) S.C. Jeong et al.: KEK Report 2010-2.
2) Y. Hirayama et al.: RIKEN Accel. Prog. Rep. 44 (2011)
25; 45 (2012) 152; 46 (2013) 176; 47 (2015).
3) H. Ishiyama et al.: RIKEN Accel. Prog. Rep. 45 (2012)
151.
4) S. Kimura et al.: reported in this RIKEN Accel. Prog.
Rep. 48.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Detector system for
the KEK isotope separation system
S. Kimura,∗1 H. Ishiyama,∗2 N. Imai,∗3 S.C. Jeong,∗2 H. Miyatake,∗2 Y. Hirayama,∗2
Y.X. Watanabe,∗2 M. Oyaizu,∗2 M. Mukai,∗1 Y.H. Kim,∗4 and A. Ozawa∗1

∗1
∗2
∗3
∗4

Department of Physics, University of Tsukuba
Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK)
Center for Nuclear Study, University of Tokyo
Department of Physics, Seoul National University- 234 -

Fig. 1. Schematic view of the detector system.

 

 







 




The KISS has been developed to study the β-decay
properties of neutron-rich nuclei around neutron number N = 126 which determine the r-process pathand form the third peak of the elemental abundance(A∼195).1,2) The detector system of the KISS requires
high detection eﬃciency for low-energy β-rays because
the nuclei of interest have small Q-value around 2
MeV. In addition, the system should be operated ina low-background environment because of the low production rates of these nuclei. Although the tolerable
count rate of the background depends on the production rates, our ultimate goal is to set around several
tens of counts per day, allowing access to these nuclei.
The detector system of the KISS consists of β-ray
telescopes, Ge detectors, and a tape transport system.
A schematic view of the detector system is shown in
Fig. 1. For particle identiﬁcation, three Ge detectors
are employed to detect K-X rays emitted from the nuclei of interest. To eﬃciently count low-energy β-rays
with low background, the β-ray telescopes are composed of three double-layered thin plastic scintillators;
the thicknesses of the ﬁrst and second layers are 0.5mm and 1 mm, respectively. The solid angle of theβ-ray telescopes is 90% of 4π.
The β-ray telescopes worked as designed. The energy spectra of the scintillators were in good agreementwith Geant4 simulations. A comparison of energy deposit in the ﬁrst layer between the simulation and themeasured result is shown in Fig. 2. The measured efﬁciency of the β-ray telescopes for low-energy β-rays
emitted from a 90 Sr/90 Y source was 55.4(15)% with anenergy threshold of 20 keVee for the ﬁrst layer and 30
keVee for the second layer.
The background rate of the β-ray telescopes wasmeasured to be 5 cps. The origins of the backgroundwere considered to be cosmic rays and electrons scattered by γ-rays from natural activities. Initially, toreduce the cosmic rays, a veto counter system was installed, which consisted of plastic scintillators. The
conﬁguration of the plastic scintillators was designed
based on the Geant4 simulation, and the designed
value of the veto eﬃciency was 92% for 1 GeV muon.
The veto counter reduced the previous background rateby 1.1 cps. In addition, to reduce the room background of γ-rays from natural activities, we installed





























 











   
Fig. 2. Energy deposit distribution of the first layer for βrays from the 90 Sr/90 Y source.

shields with low-activity Pb blocks and reduced thebackground rate by 2.4 cps. Finally, by raising theenergy threshold of the second layer to 70 keVee without signiﬁcant sacriﬁce of the detection eﬃciency for
β-rays of interest, we reduced the background rate by
0.3 cps. In total, we reduced the background rate to
1.2 cps from 5 cps.
The main component of this background rate is environmental γ-rays and accidental coincidence rate inan extra active area of the scintillators. We will replace
the present telescopes with new ones consisting of gas
counters and thin plastic scintillators. Gas counterswill be constructed with a small amount of materials
to reduce the Compton scattering of γ-rays.
References
1) S. C. Jeong et al.: KEK Report 2010-2.
2) Y. Hirayama et al.: In this report.

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Q-value resolution improvements in the spectroscopy ofdeeply bound pionic atoms using BigRIPS
T. Nishi,∗1,∗2 D. Ahn,∗2 G.P.A. Berg,∗2,∗3 M. Dozono,∗2 D. Etoh,∗2,∗4 H. Fujioka,∗2,∗5 N. Fukuda,∗2
N. Fukunishi,∗2 H. Geissel,∗2,∗6 E. Haettner,∗2,∗6 T. Hashimoto,∗2 R.S. Hayano,∗1 S. Hirenzaki,∗2,∗7
H. Horii,∗1,∗2 N. Ikeno,∗4,∗8 N. Inabe,∗2 K. Itahashi,∗2 M. Iwasaki,∗2 D. Kameda,∗2 S. Kawase,∗9
K. Kisamori,∗2,∗9 Y. Kiyokawa,∗9 T. Kubo,∗2 K. Kusaka,∗2 M. Matsushita,∗9 S. Michimasa,∗9 G. Mishima,∗1,∗2
H. Miya,∗2 D. Murai,∗2 H. Nagahiro,∗7 M. Niikura,∗1,∗2 S. Ota,∗9 N. Sakamoto,∗2 K. Sekiguchi,∗2,∗4 H. Suzuki,∗2
K. Suzuki,∗2,∗10 M. Takaki,∗9 H. Takeda,∗2 Y.K. Tanaka,∗1,∗2 T. Uesaka,∗2 Y. Wada,∗2,∗4 Y.N. Watanabe,∗1,∗2
H. Weick,∗2,∗6 H. Yamakami,∗2,∗5 Y. Yanagisawa∗2 and K. Yoshida∗2∗1

Department of Physics, University of Tokyo
RIKEN, Nishina Center∗3 JINA and Department of Physics, University of Notre Dame
∗4 Department of Physics, Tohoku University∗5 Department of Physics, Kyoto University∗6 GSI Helmholtzzentrum für Schwerionenforschung GmbH
∗7 Department of Physics, Nara Women’s University∗8 YITP, Kyoto University∗9 CNS, University of Tokyo∗10 Stefan Meyer Institute, Austrian Academy of Sciencestransfer line to tune the optics. In the new method, themomentum deviation of the particle and the position
at F0 can be deduced through position measurements
at F3 and F5 using the following equations:x0 = x3 /(x|x)03 ,δ = (x5 − (x|x)35 x3 )/(x|δ)35 .
Here, x0 , x3 , and x5 are the positions at the F0, F3, andF5 focal planes in BigRIPS, respectively. (x|x)03 and(x|x)35 are the magnifications from F0 to F3 and from
F3 to F5, respectively. (x|δ) represents dispersion. Because of achromatic transport from F0 to F3, (x|δ)03
is assumed to be 0. These transfer matrix elementsof BigRIPS were measured in advance by setting theoptics of the beam-transfer line to the standard mode,in which the F0 focal plane was achromatic. Figure 1
shows the 2D plot of the deduced δ and x0 . By using
this method, we could measure and improve the new
optics in the beam-transfer line.
As a result, we succeeded in improving the Q-value
resolution. The peaks in the online spectrum of thepresent experiment were clearly narrower than thoseof similar past experiments. The precise analysis is inprogress.
10
8

35000

6

30000

4

0

deduced x [mm]

In June 2014, we performed missing-mass spectroscopy on the deeply bound pionic atoms to mea1,2 The Q valsure their binding energies and widths.?,?)
122,1173
ues of theSn(d, He) reactions were measured using BigRIPS near the π − emission threshold. We succeeded in accumulating a sufficient number of eventsand achieved the best Q-value resolution in the spectroscopy of the Sn(d,3 He) reaction thus far. In thispaper, we report how we achieved the resolution.
We improved two aspects. First, the emittance andmomentum spread of the primary beam were reducedby optimizing accelerator parameters. Second, the optics of the beam-transfer line was adjusted to realize optimum dispersion matching. Here, the “beamtransfer line” indicates the beam line from the exit of
SRC to the F0 focal plane in BigRIPS.
The emittance and momentum spread were monitored using the beam position and angle at the achromatic focal plane F3 and the dispersive focal plane
F5 in BigRIPS. According to these measurements, thevoltage and phase of the flat top cavity of SRC, thephase of the RF of RRC, and the voltage of the rebuncher were optimized. We also optimized the phaseslit inside and the double slits downstream of the AVF
cyclotron. After optimization, we achieved an emittance of 0.2 × 2.0 πmm·mrad (horizontal) and a momentum spread of 0.027% (σ), which are dramatic improvements from those achieved in the pilot experiment: an emittance of 0.7 × 3.0 πmm·mrad and momentum spread of 0.04% (σ).
To adjust the dispersion at F0, a new method wasdeveloped using position information at the F3 andF5 focal planes. In our experiment, we developed newion optics with finite dispersion at F0 to realize the
3 However, there aredispersion-matching condition.?)no high-precision position/angle detectors in the beam-

25000

2

20000

0
-2

15000

-4

10000

-6

5000

-8
-10
-0.1

-0.08

-0.06

-0.04

-0.02

0

0.02

deduced δ [%]

0.04

0.06

0.08

0.1

0

Fig. 1. Scatter plot of x0 versus δ deduced from x3 and x5 .
The slope corresponds to the dispersion at F0.

∗2

References
1) K. Itahashi et al.: RIBF Proposal No.054 (2008).
2) K. Itahashi et al.: RIBF Proposal No.054R1 (2013).
3) T. Nishi et al.: Nucl. Instrum. Methods. in Phys. Res.
B 317 290-293 (2013).

- 235 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Development of D2 gas-filled drift chamber for spectroscopy
measurements of pionic atoms in inverse kinematics

We report the development of a D2 gas-filled drift
chamber for spectroscopy measurements of pionic
atoms. We plan to perform missing-mass spectroscopy
measurements of deeply bound pionic atoms in inverse
kinematics of the (d,3 He) reaction. We will employ a
D2 gas-filled multi-wire drift chamber (MWDC) as anactive target in a magnetic field of ∼ 1 T. A heavy
ion beam is injected into the chamber inside which thereaction occurs. The reaction angle and the energy of
forward scattered 3 He are measured using the MWDC
and silicon strip detectors, which are installed inside
the MWDC. The energy of the 3 He is approximately
60 MeV. The feasibility of the measurements was investigated through simulations in a previous study.1)
According to the results of the simulations, a position
resolution of 500 µm and enough gain to measure 60
MeV 3 He are required for the MWDC.
To check the performance of the D2 gas-filled
MWDC, we fabricated a prototype of the detector. For
the MWDC, hexagonal wire geometry, in which a sensewire is surrounded by six potential wires, is adopted.
The side length of the hexagon is 6 mm. The MWDC
consists of 10 planes, five of which are tilted (two U
planes at 18◦ and three V planes at -18◦ as shown in
Fig. 1) to measure the vertical position of charged
particles. The outer cells serve as guard wires against
chamber walls to eliminate field deformation.
Figure 2 shows the measurement setup. Inside the
MWDC, an α source (241 Am, 4.3 kBq) was placed anda silicon strip detector (12 strips, 37.5 × 50 mm2 , 300µm thick) was installed on the opposite side. The trigger was initiated by the signal of the silicon detector
and the timing of the MWDC signal was recorded using
a TDC. In this measurement, the chamber was filledwith 1 atm H2 gas instead of D2 gas as the first step.
Tracking analysis was performed and position resolution was evaluated when a HV of -1420 V was applied
to the potential wires. The α-ray detection efficiency
was higher than 99% for all planes except for the firstone. Figure 1 shows a typical event display. The drift
length in each cell is expressed as a circle and the hit
strip in the silicon strip detector is painted black. The
track was successfully reconstructed as indicated by
the red line in Fig. 1. The position resolution of theplanes with vertical and tilted wires was evaluated tobe 100 – 150 µm and 100 – 250 µm. The resolution is
sufficient for the experiment if the magnetic field does
not deteriorate the resolution considerably.
∗1
∗2
∗3

x position [mm]Y. N. Watanabe,∗1,∗2 H. Fujioka,∗1,∗3 R. S. Hayano,∗2 K. Itahashi,∗1 T. Nishi∗1,∗2 and Y. K. Tanaka∗1,∗2
NoName__66
Entries
1
Mean x0
Mean y
0
RMS x
0
RMS y
0

50

X X’X X’X
Plane
number     

40
30

U U’
 

V V’V  

20
10
0
-10
-20
-30
-40

! source

-50
-80

-60

SSD
-40

-20

0

20

40

60

80

z position [mm]Fig. 1. An example of an event display. There are potential
wires on the vertices and sense wires at the center of thehexagons. The circles represent the drift length for eachwire and the straight line is the deduced track.

! source

SSD

Fig. 2. A schematic drawing of the measurement setup.
An α source was placed in front of the first plane anda silicon detector was placed on the opposite side.

In the measurement, we observed the position dependence, i.e., the plane dependence of gas gain. In
the fifth – eighth planes, facing blank regions, the gas
gain was more than five times larger than that in theother planes when HV was -1420 V. This was due tothe geometrical configuration of the wires, and it was
qualitatively confirmed through Garfield2) calculations
that the electric field strength in these planes was effectively 5% higher. Geiger-mode behavior in theseplanes caused a rapid increase of current and made itdifficult to apply higher voltage. We found that extra
guard wires were needed facing the blank regions. Under the current condition, the detection efficiency for
60 MeV 3 He in the low-gain planes was estimated tobe less than 20%.
As the next step, we will improve gain uniformity by
applying discrete voltage to each plane.
References

RIKEN Nishina Center
Department of Physics, University of Tokyo
Department of Physics, Kyoto University

1) K. Okochi et al.: Accel. Prog. Rep. 46, 79 (2013).
2) R. Veenhof: Garfield, (http://garfield.web.cern.ch/garfield)- 236 -

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Radiation monitoring in the RIBF using ionization chamber
M. Nakamura,＊1 K. Yamada,＊1 A. Uchiyama,＊1 H. Okuno,＊1 and M. Kase＊1
In recent years, we have attempted to monitor radiation
due to beam loss in the RIBF by using self-made ionizationchambers (ICs)1),2),3) However, in the course of RIBF
operations, a part of 238U86+ ion beam accelerated at 345
MeV/nucleon struck the septum electrode of theelectrostatic deflection channel (EDC) of RRC and theseptum was damaged in December 2012. To avoid suchserious damages, the part of septum where the ion beams
can easily irradiate was cut off and molded to the“V-shaped” edge and many thermocouples (TCs) were set
at the surface of the septum. Before the septum wasdamaged by the irradiation of ion beams and the consequent
rise in temperature, these signals are input to BIS.
However, the response time of these TCs are estimated in
the order of few seconds. Furthermore, such results
showed that the septum was damaged only when a part ofthe 238U86+ beam hit the septum within 10-1 to 1 s. Hence,a faster signal for BIS with a response time of at least of theorder of 10-1 s is required. On the other hand, the responsetime of IC can be estimated to the order of 101 ms. The
response time of the whole BIS is about 1〜max. 25 ms.
Accordingly, we can obtain the response time to the orderof 10-1 s when the alarm signal from IC is used for BIS.
Hence, we investigated to introduce the alarm signal fromIC around the EDC of RRC into BIS in the case of 238U86+
ion beam acceleration.
Usually, we input the alarm signal from IC near the EDC
of SRC to BIS after the “calibration experiments”1,2). In
these experiments, the ion beams were attenuated from1/100 to 1/10 and irradiated to the EDC for a fairly shorttime and IC voltages were measured. From these results,
we can estimate the alarm levels of IC to BIS. However, it
can be very dangerous to irradiate heavy-ion beams to the
EDC of RRC because of a sudden increase in thetemperature of the septum. Therefore, we can consider thealarm levels of IC from the signals of TCs set at the septum.
When the temperature difference between the TC set at theupper part of the septum with the TC set at the beam-exitside of the septum (defined as “the maximum value of
septum temperature rising”) becomes 10℃, the alarm
signal is input to BIS.
Hence, we have compared the
maximum value of septum temperature rising with thesignal of IC set near the EDC of RRC in the machine timeof the 238U86+ beam. The result is shown in fig. 1. The
data showed little dispersion and the calibration curve in fig.
1 can be drawn. From this curve, we can recognize thatthe voltage of IC became about 1.4 V when the maximum
temperature rising of EDC reached 10℃, shown as red
dotted line in fig. 1. Then we can decide the alarm level of
IC for BIS for the 238U86+ ion beam.
＊1

RIKEN Nishina Center

Fig. 1 Correlation of IC voltage and maximum value of
septum temperature rising
We have input the alarm signal to BIS from April 28 to
May 12 and from October 16 to November 14, 2014 whenthe 238U86+ ion was accelerated at 345 MeV/nucleon. On
May 5, the BIS by the alarm signal from IC acted andstopped the operations of RIBF. Fig. 2 shows the IC
signal from May 5, 0:00 to 9:00. At 5:45, the signal
suddenly rose up to 6.4 V and the alarm signal was sent to
BIS. We could confirm that this signal reached BIS fasterthan the alarm signals from TCs set at EDC. After thissignal, any alarm from IC did not reach BIS in the machinetime of the 238U86+ beam in 2014. The cause of thisunusual signal shown in fig. 2 is unknown. In any case, as
described above, we could confirm that the faster alarm
signal to BIS can be input from the IC near the EDC of
RRC. Thus, we investigated to input the alarm signal fromIC in RRC to BIS each time heavy ions are accelerated,such as 238U86+.

Fig. 2 Signal from the IC near EDC of RRC
References
1) M. Nakamura et al.: RIKEN Accel. Prog. Rep. 44, 293 (2011)2) M. Nakamura et al.: RIKEN Accel. Prog. Rep. 45, 228 (2012)3) M. Nakamura et al.: RIKEN Accel. Prog. Rep. 47, 310 (2014)- 237 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Measurement of activation around the He gas stripper at RIBF
The activation of the He gas stripper setup caused by auranium beam was evaluated. There are several types of gas
and solid stripper setup in RIBF, and a stripper setup isselected for the beam nuclide, such as uranium, xenon, andcalcium. The He gas stripper setup has been developed for
uranium beam acceleration at RIBF. 1) The stripper setups
are often exchanged with other types to change the beam
nuclide of the RIBF accelerator. The radiation exposure
caused by the residual dose during the exchange andmaintenance works is a serious issue. Thus, evaluating theresidual dose and studying the origin of the dose areimportant to improve future setups. This evaluation is also
applicable for the shielding design of future facilities.
In this study, the activation method was applied for the
He gas stripper irradiated by a uranium beam. During themachine operation in the autumn of 2014, the samples wereplaced both inside and outside the stripper chamber. Afteruranium beam irradiation, the  rays emitted from thesamples were measured using a Ge detector.
The energy of the uranium beam on the stripper was
10.75 A MeV and the beam intensity in operation was 1200
particle nA. The beam irradiated for one month. The He gaspressure was 7 kPa, and the gas thickness wasapproximately 50 cm which corresponds to 0.7 mg/cm2.
The sample materials were aluminum and bismuth. The
aluminum sample is made of the same material as the gas
stripper chamber. Bismuth is a useful element for neutron
measurement. Radioactive isotopes of bismuth are
generated by neutron irradiation, and the generated isotope
nuclides depend on the neutron energy because of thethreshold energy of the reactions, as listed in table 1.
Some of the aluminum samples were set in the gas
stripper chamber where the He gas pressure was highest.
The distance between the nearest sample and the uranium
beam was 47.25 mm. The samples placed inside the stripper
chamber were hit by the nuclei of the fission products of theuranium beam. The other aluminum samples set outside thestriper chamber are sensitive to the neutron only because
the fission products stop in the chamber wall and do notreach outside. Thus, the aluminum samples are thebenchmark of the neutron activation of aluminum chamber
itself. The bismuth samples are set with the aluminum
samples outside the chamber to obtain the neutron energy
on the aluminum samples.
Figure 1 shows the measured -ray spectrum obtained
from the aluminum sample set inside the chamber after
cooling for 13.5 days. Table 2 lists the identified nuclides
with short half lives. Typical nuclides of the fission
products from the 238U beam were observed.  ray peaks
from long-lived nuclides were not observed yet in the
spectrum owing to the high background  rays from the＊1

RIKEN Nishina Center

Count/second/efficiency

A. Akashio,＊1 K. Tanaka,＊1 and H. Imao＊1

100

Al sample
10

1

0.1

0

500

1000

1500

2000

Energy (keV)
Fig. 1. Typical  ray spectrum of the Al sample set in thegas stripper chamber. Many energy peaks caused byradioactive isotopes generated from the fission of 238U
were observed.

short-lived nuclides. -ray peaks of aluminum itself, such as
24
Na with a 15 hour half life, were not found.
Table 1 lists the observed bismuth isotopes in the natural209
Bi samples that were set outside the stripper chamber.
The result suggests that the energy of irradiated neutrons on
the bismuth samples was up to 22.55 MeV, since  raysfrom the 205Bi nucleus, which have a threshold energy of
28.6 MeV, were not detected.
After cooling the samples for a long time and backgroundlevels become low,  rays from the long-lived nuclides will
be detected. The result will be compared with a Monte
Carlo simulation result to evaluate radiation issues in the
future.
Table 1. Threshold of neutron energy corresponding to the
production of radioactive bismuth isotopes observed in thisstudy.
NuclideHalf life
Reaction
Threshold
207
209
Bi
31.6 year
Bi(n,3n)207Bi 14.12
206
209
Bi
6.4 dayBi(n,4n)206Bi 22.55
Table 2. Typical radioactive nuclei observed in thealuminum sample inside the stripper chamber.
NuclideHalf life
NuclideHalf life
95
136
Zr
64 dayCs
13 day95
140Nb
35 dayBa
13 day99
140
Mo
2.8 dayLa
1.7 day99m
141
Tc
6.0 hourCe
32.6 day103
147
Ru
39 dayNd
11 day131
I
8.0 day
References

1) H. Imao et al.: Proc. of IPAC2013, Shanghai, China, May 2013
THPWO038, p.3851 (2013).

- 238 -

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Beam preparation for fee-based utilization of a 70-MeV/A Kr-beam
T. Kambara∗1 and A. Yoshida∗1
In October 2014, RIKEN provided a 70 MeV/A
Kr beam from the RIKEN Ring Cyclotron (RRC) to
private companies as the ﬁrst fee-based utilization.1)
Since the customers required irradiations in an atmosphere with a uniform ﬂux distribution over a large
area and speciﬁed linear energy transfer (LET), we developed the following system at the E5A beam line andsuccessfully delivered desired beams to the customers.
The uniform beam-ﬂux distribution was achieved
with wobbler magnets and a scatterer foil. A pairof 60-Hz wobbler magnets deﬂected the beam fromthe RRC vertically and horizontally so that the beam
center traced a circle. At about 68 cm downstream,
the beam passed through a scatterer (48-µm thick Aufoil), where multiple scattering brought about a lateralvelocity distribution. At about 392 cm downstream
from the scatterer, the beam passed to the atmospherethrough an 8-cm diameter and 75-µm thick polyimide(Kapton) vacuum-separation window.
In the atmosphere part of the beam path, we usedan energy degrader and several detectors to control the
LET and measure the beam characteristics. Figure 1
shows the conﬁguration. After the window, there werean ionization chamber (IC: Applied Engineering Inc.,
AE-1341S) and a 0.5-mm thick plastic scintillator formeasuring the total beam intensity. The IC had a 5cm diameter window that determined the beam size
downstream. An adjustable energy degrader (WoodBell Co. Ltd.) followed to control the LET, where thebeam energy was adjusted by inserting up to eight Al
foils with 8-cm diameter and thicknesses of 12.8, 23.8,
48.6, 100.2, 100.8, 196.4, 486.0, and 975.4 µm. We caninsert any combination of the foils by using a remotecontrol pneumatic system to set the LET almost continuously. After the degrader, two sets of ∆E + E
Si-detector stacks were mounted on a motor-driven linear slider; the detectors can be not only placed at thecenter of the beam path but also horizontally moved
across the beam for measuring the beam-ﬂux distribution. The customer samples were placed at about 10
cm downstream from the Si detectors.
Beam scanning with the Si detectors revealed thatthe beam ﬂux was uniform within ±1.8 % over a diameter of about 35 mm. Another measurement with a
GAFCHROMIC-ﬁlm irradiation showed that the local
deviation of the dose was within ±5 %.
For the beam-intensity measurements, the scintillator counted the ions from nearly-zero intensity toabout 2.5 × 105 ions/s and the IC was available from
400 to 2.5 × 106 ions/s.
We adjusted and veriﬁed the LET at the sample in∗1

RIKEN Nishina Center- 239 -

Fig. 1. Setup of Kr-beam irradiation after the window.

the following way: Increasing the thicknesses of the degrader foils, we measured the beam energy by using the
Si detectors until the beam was totally stopped. Then
we compared the thickness-energy relation to SRIM
calculations2) and obtained the stopping power in thesample as a function of the degrader thickness, witha correction for the energy loss in the atmosphere between the Si detector and the sample. We considered
the stopping power as the LET.
Figure 2 shows the relation between the LETs of40
Ar, 84 Kr, and 132 Xe ions at the surface of Si andtheir ranges in the material. The 70-MeV/A 84 Kr
beam from the RRC has the maximum energy of 43
MeV/A at the irradiation position, which corresponds
to an LET between 13.2 and 40.9 MeV/(mg/cm2 ); thesolid line in Fig. 2 indicates this region. In addition, if we use 95-MeV/A 40 Ar and 26-MeV/A 132 Xebeams accelerated by the RRC, an LET from 2.3 to 69
MeV/(mg/cm2 ) is available at the same beam line.

Fig. 2. LETs of 40 Ar, 84 Kr, and 132 Xe ions at the surfaceof Si as functions of their ranges. The solid lines correspond to the ions accelerated by the RRC and extracted
to the atmosphere.

References
1) A. Yoshida et al.: In this report.
2) J. F. Ziegler: http://www.srim.org.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Implantation of 7 Be and 22 Na beams for wear diagnostics application
A. Yoshida,∗1 T. Kambara,∗1 H. Takeichi,∗1 H. Yamaguchi,∗2 T. Nakao,∗2 D. Kahl,∗2 R. Uemoto,∗3 andN.Takahashi∗4
To develop a method for wear diagnostics of industrial material using RI beams,1,2) intense beams of 7 Be
(T1/2 = 53 days) and 22 Na (T1/2 = 2.6 years) provided
by CRIB were implanted in the surface of machineparts. Here we describe the generation and characterization of the RI beams.
The 7 Be beam was produced via H(7 Li,7 Be)n reaction. A beam of 5.7 MeV/A 7 Li2+ with an average intensity of 1.7 particle µA (pµA) was introduced
to CRIB and passed through a cryogenic H2 gas target at a pressure of 760 Torr and cooled by liquid
N2 to 90 K. The produced 7 Be4+ beam was introduced to a dedicated vacuum chamber at the F2 focal
plane. A position-sensitive Si detector (PSD, Hamamatsu S5378-02), an energy degrader, and a rotating
irradiation sample holder were installed in the chamber. The energy and proﬁle of the RI beam were measured using the PSD. The energy of the 7 Be beam was
4.16 MeV/A, and the beam spot size was 4.8 × 8.1 mm
in FWHM when the momentum spread was set to ±3.1%. The relatively large beam-spot size seems related
to a halo of the beam spot at the gas target. The implantation rate of the 7 Be beam was approximately 60
kBq/h, according to a gamma-ray measurement after
the implantation.
The 22 Na beam was produced via the H(22 Ne,22 Na)nreaction. A 6.1 MeV/A 22 Ne7+ beam with an averageintensity of 0.25 pµA was introduced to the H2 gas
target at 400 Torr and 90 K. The energy and size ofthe 22 Na11+ beam at F2 was 3.67 MeV/A and 4.7×4.3
mm in FWHM, respectively, with a momentum spreadof ±3.1 %. The implantation rate was approximately
0.3 kBq/h.
For wear-loss diagnostics, the depth proﬁle of implanted RI should be controlled and characterized accurately. The depth proﬁle was controlled using a rotating energy degrader that had eight foils of diﬀerent
thicknesses. The foils were circularly placed on a wheelof diameter 14 cm rotating at 12 rpm so that they crossthe RI beam path one by one. An additional degrader
foil can be mounted on a beam collimator with a diameter of 10 mm placed downstream of the wheel.
To study the implantation-depth proﬁle, we ﬁrst irradiated a stack of 2-µm-thick Al foils with the RI
beams, and measured the radioactivity of each foil witha Ge detector. Then we obtained the beam-energy
spectra by the PSD, and calculated the range distribution of the ions in Al with the SRIM code3) . Figure
∗1
∗2
∗3
∗4

RIKEN Nishina Center
Center for Nuclear Study, Univ. of Tokyo
S.H.I. Examination & Inspection, Ltd.
Sumitomo Heavy Industries, Ltd.

- 240 -

1 shows a case of a 22 Na beam with a narrow momentum distribution of ±1 % implanted to the stackafter the rotating degrader with a blank and seven Al
foils with thicknesses of 4.9, 7.6, 11.9, 16.9, 23.8, 27.4,
and 31.7 µm. The depth proﬁle with the stacked-foil
is shown by black circles as relative intensities of theradioactivity in the foils. The horizontal and vertical error bars indicate the thickness and the statisticalerror for each foil. The dotted line shows the SRIM
calculation of the range distribution from the energy
spectrum. Below a depth of 5 µm, the corresponding
energy spectrum could not be measured as it was below
the detector threshold. The triangles indicate normalized fractions of the foils obtained by re-binning therange spectrum according to the stack-foil thicknesses.
We multiplied a factor of 0.97 to the stopping power of
the SRIM calculation for optimum agreement between
the stacked-foil measurement and the calculation.
The conventional stacked-foil method is reliable because it directly measures the implanted RI, but its
depth resolution is limited because assembling manythin foils as a stack is hard work. On the other hand,the energy measurement with a Si detector is simpler,
but the accuracy of the implantation-depth distribution depends on the range calculation. Here, we combined the two methods with a correction factor for the
SRIM calculation results and obtained a continuous
implantation-depth proﬁle.

Fig. 1. Implantation-depth profile of 22 Na beam in stacked
Al foils.

References
1) A. Yoshida et al.: “Operation report of industrial cooperation team”, in this report.
2) A. Yoshida et al.: Nucl. Instr. Meth. B 317, 785 (2013).
3) J. F. Ziegler: “The SRIM code, the stopping and rangeof ions in matter”, http://www.srim.org.

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Development of a GEM tracker for the J-PARC E16 experiment
W. Nakai∗1,∗2 for the J-PARC E16 Collaboration
Fig. 3. We tested four types of chambers, which aresummarized in Table 1. We have achieved a position
resolution better than 100 µm and an eﬃciency of 90%
up to an incident angle of 30◦ for all sizes of GTRs.
Table 1. The summary of tested chambers.

Residual [mm]Size
100 mm
100 mm
200 mm
300 mmDrift gap
7 mm
5 mm
7 mm
7 mm

Legend in Fig. 2 & 3
GTR100 A
GTR100 B
GTR200
GTR3000.2
0.18

GTR 100 A

0.16

GTR 100 B
GTR 200

0.14

GTR 300

0.12
0.1
0.08
0.06
0.04
0.02
0

0

10

20

30

40
Incident Angle [degree]

Fig. 2. The result of 3 mm gap equivalent analysis. Standard deviations of residual as functions of incident angle.

Efficiency

The main aim of the J-PARC E16 experiment isto measure the mass modiﬁcation of ϕ mesons in nuclear matter at J-PARC in order to study the originof hadron mass. The details of this experiment arepresented in another article of this report1) .
We employed a tracking detector using the Gas Electron Multiplier (GEM)2) , and have been developing it
to be a position-sensitive detector in a magnetic ﬁeld
with a magnitude of 1.8 T at the center of the magnet.
Our requirement for this detector is a position resolution of 100 µm up to an incident angle of 30◦ in a highcounting rate environment of up to 5 kHz/mm2 . Our
GEM tracker consists of a drift cathode, triple-GEM
stack, and readout strip board. We chose a strip pitchof 350 µm to achieve the required position resolution.
For inclined tracks, a hit position of a GEM
tracker is determined with a technique called “ timing
method ”, where the spatial distribution of a chargecluster generated by a charged track in the drift gap isreconstructed using the arrival timing information of
signals from readout strips. As shown in Fig. 1, thedistance from ionization electrons to each strip (z) can
be calculated by vd × t, where t is the arrival time andvd is the drift velocity. After calculating each z, we
ﬁt a straight line to these points and determine theintersection point of the line with the center of drift
gap.
In the experiment, a drift gap of 3 mm is desirable toreduce the signal pile-up; however the test experiment
was performed using a wider gap. Thus, additional
analysis is performed to evaluate performance for a
3 mm gap. The analysis only uses signals that havesmaller drift times corresponding to the 3 mm gap.
Results of this analysis are shown in Fig. 2 and1
GTR 100 A
GTR 100 B
GTR 200
GTR 300

0.99
0.98
0.97
0.96
0.95

z Cathode plane
z=vt
Drift gap center

0.94
0.93

Drift gap = 3 - 7 mm

0.92
0.91
0.9

0

GEM
Readout

10

20

30

40
Incident Angle [degree]

Fig. 3. Detection eﬃciencies as functions of incident angle.

Track

References
Fig. 1. Positions where ionization electrons are generated
can be reconstructed by vd × t.
∗1
∗2

Department of Physics, The University of Tokyo
RIKEN Nishina Center- 241 -

1) S.Yokkaichi, et al, in this report
2) F. Sauli, Nucl. Instrum. Meth. A386 (1997) 531

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Preparation status of the J-PARC E16 experiment: measurement ofspectral change of vector mesons in nuclei
S. Yokkaichi∗1 for the J-PARC E16 Collaboration
We have proposed the experiment E161) to measure
the vector meson decays in nuclei in order to investigate the chiral symmetry restoration in dense nuclear matter. The experiment will be performed at
the J-PARC Hadron Experimental Facility. Scientiﬁc(“stage 1”) approval was granted to the experimentE16 by PAC in March 2007. For the full approval,
we were required to demonstrate the experimental feasibility and show the prospects of acquiring suﬃcient
funds and of beam-line construction. Toward the full
approval, the technical design report (TDR) was submitted to PAC held in May 2014, and the TDR is being
revised as per the requirements provided by PAC, andthe revised TDR will be submitted to the PAC held in
July 2015.
The aim of the experiment is to perform a systematic
study of the spectral modiﬁcation of vector mesons,particularly the ϕ meson, in nuclei, using the e+ e− decay channel with statistics that are two orders larger inmagnitude than those of the preceding E3252) experiment performed at KEK–PS. In other words, the aim isto accumulate 1×105 to 2×105 events for each nuclear
target (H, C, Cu, and Pb) and to deduce the dependence of the modiﬁcation on the matter size, and themeson momentum. At the same time, the e+ e− decaysof the ρ, ω, and J/ψ mesons can be measured, while
the yields depend on the trigger condition required tosuppress the background e+ e− pairs.
For the experiment, we plan to use a 1010 -pps, 30GeV proton beam in the high-momentum beam line,
which is being constructed at J-PARC. In order to increase the statistics by a factor of 100, we will construct
a large-acceptance spectrometer that can be operated
under 107 Hz nuclear interactions at the target. In
order to cope with such a high-interaction rate, GEM
has been adopted for constructing new tracking and
PID detectors.
The construction of the high-momentum beam line,
where we perform the experiment, has been on-goingsince 2013 by KEK. The ﬁrst beam is scheduled aroundthe end of JFY 2016; it was delayed by a year becauseof the beam stoppage due to the radiation accident
at J-PARC in May 2013. The schedule of the spectrometer magnet reconstruction is also delayed, and it
is expected to be completed by July 2015. After thecompletion of the magnet reconstruction, we can begin
installing the detectors in the magnet. The target dayof the construction is March 2016. Our spectrometerhas 26 modules. Owing to the budget limitations, ourﬁrst goal of the staged construction plan is to construct∗1

RIKEN Nishina Center- 242 -

eight modules, which correspond to approximately one
third of the full installation.
The development of the detectors has almost completed, and we are moving to the production phase.
For the GEM Tracker (GTR)3) , the production of
GEM has been underway since 2013. Six modules (outof eight, as mentioned above) are currently under construction. The production of frames made of CFRP,
which is used to install the GEM chambers in the spectrometer, started in 2014. For the HBD4) , which isone of our electron ID detectors, only two modules
are currently under construction. The lead-glass (LG)EM Calorimeter, another electron ID detector, utilizes
the recycled LG from the TOPAZ experiment. The reshaping of LG blocks, for eight modules (330 blocks), isto be completed at the KEK engineering center within
JFY 2014.
The development of the read-out and trigger modules are underway. As a pre-ampliﬁer and front-end
module (FEM) of GEM detectors, an APV25 chip and
SRS, both are CERN-made, are adopted. We joined
the RD515) collaboration in CERN in July 2013 to codevelop GEM-related electronics. For HBD, we use
the RD51-made APV25 preamp. For GTR, a more
smaller preamp using the APV25 chip was fabricatedby ourselves and the production started in January
2015. The ﬁrst version of the FEM for the LG is tested
and the revision is on-going.
For the trigger, signals from the GEM foil of GTR
and HBD are used. ASICs for the amp-shaperdiscriminator to generate the trigger primitive of thetwo detectors has been produced under the cooperation of the KEK e-sys group. For GTR, the test of thesecond version is to be started. The test of the ﬁrst
version for HBD is almost completed. To generate a
global trigger signal, an FPGA board “UT3”(Belle II
collaboration) is used. To transfer the trigger primitives to UT3, we developed another module called“TRG-MRG”. The ﬁrst version of TRG-MRG is already delivered and will be tested at KEK. These tests
will be completed by the end of JFY 2014.
References
1) S. Yokkaichi et al.: J-PARC proposal No. 16(http://j-parc.jp/researcher/Hadron/en/pac_0606/
pdf/p16-Yokkaichi_2.pdf),
Lect. Notes Phys. 781 161 (2009).
2) M. Naruki et al.: Phys. Rev. Lett. 96, 092301 (2006),
R. Muto et al.: Phys. Rev. Lett. 98, 042501 (2007).
3) W. Nakai et al.: in this report.
4) K. Kanno et al.: in this report.
5) http://rd51-public.web.cern.ch/RD51-Public/

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Simulation of HBD response in the J-PARC E16 experiment basedon test results

A hadron blind detector (HBD) has been developed for the J-PARC E16 experiment.1) The E16 experiment aims to investigate the origin of QCD mass
through the spectral change of a ϕ meson in a nucleus.
The mass spectrum is reconstructed through electronpositron decays. A detector for electron identiﬁcationis required. The HBD is utilized in the E16 experiment for this purpose. The HBD identiﬁes electrons
by converting Čerenkov photons emitted by an incident
electron in a CF4 radiator into photoelectrons using a
CsI photocathode. These photoelectrons are ampliﬁed
by gas electron multiplier2) (GEM) foils and are subsequently read out as an electric signal. Other charged
particles apart from the electron do not emit Čerenkov
photons in the momentum region where we perform themeasurement, 0.4–3 GeV/c. With this scheme, the
HBD distinguishes electrons from the other charged
particles.
We have constructed a prototype of the HBD and
performed a test experiment using a positron beam of
1.0 GeV/c at Research Center for Electron Photon Science, Tohoku University. We successfully observed 11
photoelectrons per incident positron with the prototype3) when the incidence angle to the beam was 0◦ .
This result was consistent with the expected result calculated based on the performance of each detector element. However, only HBD response to an electron was
obtained in this beam test, and the response to a pionis also required to determine the pion rejection power
for a given electron detection eﬃciency. We estimatedthe HBD response to a pion through simulation.
For this simulation, we used the HBD response toa pion that has already been obtained with anotherprototype. This prototype has a smaller pad readout
and longer gap lengths between GEM foils. Taking
into account of the diﬀerences between the prototype
and another prototype, we performed the simulation
to evaluate the prototype response to a pion. With
this simulation, we estimated an electron detection efﬁciency of 85% with a pion rejection factor of 50 for
1.0 GeV/c electrons and pions at the threshold of 6.5 ewhen the incidence angle was 0◦ . In the actual J-PARC
E16 experiment, charged particles including electronsand pions are emitted from a target and the incidence
angle of these particles to the HBD is approximately 0–
45◦ . Furthermore, these charged particles move along
a curved line because of the magnetic ﬁeld in the spectrometer used in the experiment, resulting in a larger∗1∗2

RIKEN Nishina Center
Department of Physics, Graduate School of Science, The
University of Tokyo- 243 -

Electron detection efficiency

K. Kanno∗1,∗2 for the J-PARC E16 Collaboration
1.2
1
0.8
0.6
0.4
0.2
0
0

1

2
3
4
Momentum [GeV/ c]5

Fig. 1. Electron detection eﬃciency as a function of electron momentum.

incidence angle to the HBD.
To evaluate the electron detection eﬃciency in theoﬄine analysis, we performed another simulation by
including the possible momentum and incidence angle distribution of electrons from ϕ meson decays.
In the simulation, ϕ mesons were generated by a 30
GeV/c proton-induced reaction using the nuclear cascade code JAM.4) These ϕ mesons decay into electronsand positrons, and then electrons move according to
the magnetic ﬁeld. We assumed pion samples had
the same track as the electron samples. The HBD
responses to an electron and a pion were estimatedbased on the result of the beam test and the simulation
mentioned in the previous paragraph. The electron detection eﬃciency as a function of electron momentum
with a pion rejection factor of 100 is shown in Fig. 1.
The eﬃciency decreases in the region of 0.4–1.5 GeV/c.
This fact reﬂects that the signal amplitude of a pionincreases with decreasing momentum. A pion sample
having lower momentum has a larger curvature in amagnetic ﬁeld and consequently has a larger incidence
angle to the HBD, namely, a larger signal amplitude.
The large errors in the high-momentum region are due
to availability of limited statistics. The overall eﬃciency is 60% with a pion rejection factor of 100 at thethreshold of 7.5 e, which meets the requirement of theexperiment.
As the next step, we will measure the response toa pion, which has been simulated, using a pion beamwith GEM foils and the readout pad conﬁguration forthe production type of HBD.
References
1) S. Yokkaichi et al.: in this report
2) F. Sauli: Nucl. Instr. and Meth. A 386, 531 (1997)
3) K. Kanno et al.: RIKEN. APR. 47, 226 (2014)4) Y. Nara et al.: Phys. Rev. C61, 024901 (1999)

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Resistive Plate Chamber (RPC) for BGOegg Experiment†
T. Nam,*1,*3 N. Tomida,*2 M. Niiyama,*2 H. Ohnishi,*1,*3 C.-Y. Hsieh,*4 M.-L. Chu,*4 and W.-C. Chang*4
We have developed and installed a time-of-flight system
to measure the energy of charged particles, especially protons,
for BGOegg experiment. The design of the chamber was
based on the RPC chamber for LEPS2 experiment, which wehave already reported previously in ref.1).
BGOegg experiment using LEPS2 beamline to study
hadron photoproductions is currently under operation at
SPring-8 (Super Photon ring-8 GeV). The main detector is
the BGOegg calorimeter which made from 1320 ��� ��� ���
crystals assembled in the shape of an egg (fig. 1). The
BGOegg calorimeter can detect high-energy gamma ray
coming out from the target in an open angle of 24 to 144
degrees; an energy resolution of 1.3 % at 1 ��� gamma
energy was achieved and previously reported at ref 2).

Figure 1: setup of the BGOegg experiment

The RPC is placed 1�.� � downstream from the target,and covers an open-angle of 7� in the horizontal and 4�
in the vertical. In BGOegg experiment, we are measuring
the �� mass modification to study the �� �1� anomaly
problem using a nuclear target with the BGOegg detector
system and the LEPS2 high-intensity photon beam. We arelooking for the presence of the �� meson in its decay to��� � � � � � in the nuclear medium. In addition, themomentum of a forwardly recoiled proton in the A(�� ��)
reaction will be measured by the RPC. We use the RF signal
as the start signal and the RPC signal as the stop signal, thetime resolution must include the contribution of all
uncertainty sources such as the amplifier, discriminator,
RPC, TDC and the time reference RF.
�
�
�
�
�
�
�
� ���
� ����� ����� ����� ������� ����
����For the timing measurements, CAEN V1290A TDC
modules were used. The resolution of the RF signal isabout 4 ��. The electron bunch width in the SPring-8 storage
ring is ~1� ��. The time resolution of V1290A is �0 �� after
the integral non linearity corrections. If we assume that theinternal time resolution of RPC is �0��3), then the remaining
contributions come from Front-End-Electronics(FEEs) andare considered to be less than 40 ��. In total, the resolution of
our RPC system is expected to be �0 ��.
During the development, we have produced and tested formany aspects of the RPC such as geometry of the pad/strip
read-out, width of the gap, number of gap and trigger rate.

The ��0 �� � 2 stacks � � gaps �.� � 100 ��� strip
read-out with anode inside geometry reached a time
resolution of �0 �� and an efficiency more than 99%
above 10 ������ 1). The coverage area is 3.� � � �� .
The wall consists of 32 RPC modules as shown in fig. 2; 2
rows with 16 modules each. The size of an RPC module is116.2 cm (L) × 24.7 cm (W) × 2.7 cm (H). The active areaof an RPC module is 20.75×100 ��� and the active areaof each RPC module overlaps about
0.3 cm with each other in thehorizontal and 0.5 cm in the vertical.
The custom FEEs of our RPC
including the amplifier, discriminatorand stretcher were developed by Dr.
M.-L. Chu. A method for the signal
Figure 2: RPC wall
read-out to reduce the total number of
TDC and ADC channels by half was applied, and this method
is shown in fig. 3.
The special feature of the amplifier is that it is designed tominimize the reflection of the signal. The input impedance of
the amplifier is set to 40 ��� and it matches well with the
impedance of our RPC,
which is about 30 –40 ���. The output
signal of our custom
discriminator has thesame width as the
input. This width isvery narrow, typically Figure 3: The sketch of FEEs for RPC
around � ��. And thiswidth is too narrow to be read by V1290A TDC. Therefore,
we developed an additional stretcher to be placed after thediscriminator to stretch the pulse width to 10 �� so that it
can be read by V1290A TDC. For the timing measurement,
we use CAEN V1290A TDC modules. For the charge
measurement, we use LeCroy Fast Encoding and Readout
ADCs (FERAs). The ADC information is used fordeveloping correction parameters and a strip separation
method.
BGOegg experiment started acquiring data from April
2014, and the performance of the RPC is being checkedagainst many aspects and the calibrations are under way toensure the reliability of the RPC’s data for physics studies
in near future.
References†

This manuscript summary the results which were reported at
JINST 9 C10008, 2014.
*1
Research Center for Nuclear Physics, Osaka University.
*2
Physics Department, Kyoto University.
*3
RIKEN Nishina Center*4
Institute of Physics, Academia Sinica- 244 -

1) N. Tomida, H. Onishi, M. Niiyama, T. Nam, Large strip RPCs
for the LEPS2 TOF system, Nucl. Instr. Meth. A, 766, 283-287,
2014.
2) T. Ishikawa et al., ELPH Annual Report Vol.1, 61 (2012).
3) C. Williams et al, A 20 ps timing device-A Multigap Resistive
Plate Chamber with 24 gas gaps, Nucl. Instr. Meth. A, 594, 39–
43, 2008.

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Quality assurance test of pixel detector ladders for VTX
T. Sumita,∗1 Y. Akiba,∗1 H. Asano,∗1,∗2 T. Hachiya,∗1 M. Kurosawa,∗1 T. Moon,∗1,∗3 H. Nakagomi,∗1,∗4
C. Pancake,∗5 H. Sako,∗1 S. Sato,∗1 A. Taketani,∗1 and the PHENIX VTX group
A silicon vertex tracker (VTX) was installed in the
PHENIX detector at the Relativistic Heavy Ion Collider. The VTX detector consists of two inner layersof silicon pixel detectors and two outer layers of silicon strip detectors. A pixel ladder is composed of amechanical stave, four hybrid sensors1) , and two readout buses. A hybrid sensor is an assembly consistingof a silicon pixel sensor and four readout chips (ALICE1LHCb2) ) bump-bonded to the sensor. One ladderhas 16 readout chips and one readout chip has 8,192
pixels, with a pixel size of 425 µm × 50 µm, organizedin 32 columns and 256 rows.
We fabricated new spare silicon pixel ladders. In
order to ensure correct operation before the assemblyof the VTX detector, quality assurance (QA) test of
the ladders need to be performed. This report presents
the results of the QA test for the ladders.
The QA test system consists of Silicon PIxel ReadOut (SPIRO) modules, Front-End Module (FEM), andNOVEC HFE-7200.3) The SPIRO modules provide allelectricity, control the readout chip of the sensor module and read out pixel data The FEM is an interface
between the SPIRO modules and the data acquisition
system. NOVEC HFE-7200 was used to cool the readout chips. The following tests are performed for eachladder.
(1) Current consumption:
The current consumption of the analog and digital circuits of the readout chips are measured.
(2) JTAG functionality:
It is conﬁrmed whether the conﬁguration settings in the chip can be controlled by using Joint
Test Action Group (JTAG4) ) protocol.
(3) Minimum threshold:For all chips, the minimum threshold in all pixels
are determined.
(4) Pulse test:
Pulse test is to check for dead chips and connections. The test pulse from the pulsar inside thechip is transmitted to each pixel cell.
(5) Test using a β-ray source (90 Sr):
Faulty bump bonds and the maximum eﬃciency
are evaluated by β-source measurements
The ladder is biased at 10 V during the measurement.
A total of 7 ladders were tested, and correct operation of all the ladders was conﬁrmed except for one lad∗1
∗2
∗3
∗4
∗5

RIKEN Nishina Center
Department of Physics, Kyoto University
Department of Physics, Yonsei University
Department of Physics, University of Tsukuba
Department of Physics, Stony Brook University- 245 -

Fig. 1. Typical result of a readout chip in the source test.
The horizontal and vertical axes represent pixel position
along the column and row directions, respectively. Low
gray-levels represents a low number of hits.

der. Four chips (one hybrid sensor) of the incorrectly
working ladder did not respond to the tests because ofa short circuit in the readout bus. A typical result ofa readout chip in the source test is shown in Fig. 1.
The ineﬃcient area at the bottom of columns 1, 9, 17,
and 25 is attributed to the presence of the test pulse
signal generator on the readout chips, which aﬀected
the readout circuit.
In summary, QA tests for the seven new assembled
pixel ladders were performed. The results conﬁrmedthat six ladders are working properly and that a part ofone ladder is not functional. One of functional ladders
will be used in the 2015 run.
References
1) T. Sumita et al.: RIKEN Accel. Prog. Rep. 47 230(2013).
2) W. Snoeys et al.: Nucl. Instr. Meth. A 466, 366 (2001).
3) M. Kurosawa et al.: RIKEN Accel. Prog. Rep. 43 208(2010).
4) IEEE std 1149.1.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

Fast clear technique for NEBULA data acquisition for SAMURAI17
experiment
Y. Togano,∗1,∗2 Y. Kubota,∗2,∗3 H. Baba,∗2 and H. Otsu,∗2 for the SAMURAI17 collaboration
A fast clear technique for NEBULA data acquisition(DAQ) was newly introduced for the 132 Sn(p, n) experiment at SAMURAI.1) The technique enabled themeasurement of recoil neutrons and projectile-like neutrons in coincidence. NEBULA DAQ could not workwith the main trigger for the (p, n) reaction measurement because the recoil neutrons were slow.
The incoming 132 Sn beams were detected by beamtagging detectors: SBT1 and SBT2. We deﬁne thesignal from SBT1 as “Beam” in this report. Recoil
neutrons from the (p, n) reaction were measured using WINDS2) surrounding a liquid hydrogen target.
The charged outgoing particles were analyzed by using
the SAMURAI system. The outgoing neutrons fromthe breakup of reaction products were measured byusing NEBULA. The main trigger of the experiment
was a coincidence of Beam and WINDS. Because of
the slow neutrons from the (p, n) reaction detected byusing WINDS, the trigger decision of the experimentwas ∼ 300 ns slower than the that with the standard
SAMURAI setup.3)
The main trigger for the experiment was controlled
by using the GTO module.4,5) The trigger for NEBULA DAQ was a coincidence of Beam and NEBULA signals (Beam × N EBU LA trigger). The analog and time information of NEBULA was obtainedby using CAEN V792 QDC and V775 TDC modules, respectively. The VME module used to interrupt NEBULA DAQ was RPV-130 by REPIC. The
fast clear of V792 and V775 could be performed by
inputting the fast clear signal to the modules during
their data conversion. The dead time of the fast clear
was 600 ns. Figure 1 shows the circuit diagram of
NEBULA DAQ for the fast clear. The interrupt of

NEBULA DAQ was performed by using a 10 µs delayed main trigger signal to allow time for the data
conversion of QDC and TDC. If the DAQ system wasinterrupted when NEBULA data were empty owing to
no Beam × N EBU LA trigger or the dead time of fast
clear, the NEBULA data were recorded as an empty
event. The fast clear signal was generated by anticoincidence between Beam×N EBU LA (synchronizedwith DAQ start/stop) and the main trigger. If themain trigger was ﬁred to acquire data during the deadtime of fast clear for NEBULA, a fast clear ﬂag wasstored by a coincidence register (coin. reg. 1). The
NEBULA-accepted trigger was Beam×N EBU LA vetoed by the dead time of NEBULA DAQ and the fast
clear of V775/V792. A ﬂag for Beam × N EBU LA
was stored by a coincidence register if it was coincident with the main trigger (coin reg. 2). NEBULA
DAQ could be switched to the singles mode, in which
the trigger was generated by NEBULA itself for calibrations, in B2F experimental area.
In the experiment, the typical rate of the main trigger and the Beam × N EBU LA trigger were 2.4 kHz
and 1.6 kHz, respectively. Owing to the dead time of
the fast clear, ∼ 0.7% of NEBULA data could not becollected. Fig. 2 shows the time versus crystal ID plotof NEBULA. The locus at approximately 60 ns corresponds to fast neutrons from the target region indicating that NEBULA DAQ functions eﬀectively. This fast
clear technique can be applied to other experiments byadjusting the delay for the Beam × N EBU LA signal(300 ns in this experiment).

Fig. 2. Time versus crystal ID plot of NEBULA.

References

Fig. 1. Circuit diagram for NEBULA DAQ with fast clear.
∗1
∗2
∗3

Department of Physics, Tokyo Institute of Technology
RIKEN Nishina Center
Center for Nuclear Study, University of Tokyo- 246 -

1) M. Sasano et al.: RIKEN Accel. Prog. Rep. 48 (2015).
2) K. Yako et al.: RIKEN Accel. Prog. Rep. 45, 137(2012).
3) T. Kobayashi et al.: Nucl. Instrum. Meth. B 317, 294(2013).
4) H. Otsu et al.: RIKEN Accel. Prog. Rep. 46, 146 (2013).
5) H. Baba et al.: RIKEN Accel. Prog. Rep. 47, 235(2014).

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Test of the advanced implantation detector array (AIDA) at RIBF
C.J. Griffin,*1 T. Davinson,*1 A. Estrade,*1 D. Braga,*2 I. Burrows,*3 P. Coleman-Smith,*3 T. Grahn,*4 A. Grant,*3
L.J. Harkness-Brennan,*4 M. Kogimtzis,*3 I. Lazarus,*3 S. Letts,*3 Z. Liu,*1 G. Lorusso,*5 K. Matsui,*5,*6 S. Nishimura,*5
R.D. Page,*4 M. Prydderch,*2 V. Pucknell,*3 S. Rinta-Antila,*4 O. Roberts,*7 D. Seddon,*4 J. Simpson,*3 J. Strachan,*3
S.L. Thomas,*2 and P.J. Woods*1

Fig. 1: A photograph of the fully constructed AIDA
assembly.
The advanced implantation detector array (AIDA)1)
represents the latest generation of silicon implantation
detectors for use in decay spectroscopy measurements of
exotic nuclei at fragmentation beam facilities.
Designed to improve upon current generation, the AIDA
features high detector pixelation and fast overload recovery(~1 s), required at modern RI facilities with increasingly
high secondary beam intensity and access to isotopes withvery short half-lives.
Application specific integrated circuits (ASICs)2) were
specifically designed to meet the above requirements. One
ASIC can process 16 data channels, each with two
dedicated preamplifiers: one with selectable gain to cover
the low and medium energy ranges of up to 1 GeV, and theother, a low-gain amplifier that covers the full dynamic
range of 20 GeV. Detector signals are carried via flexible
Kapton PCBs to the front end electronics (FEE) cards,
which support 64 channels of instrumentation. The FEE
cards contain the following: multiple analog-to-digitalconverters (ADCs) for use in signal processing; afield-programmable gate array (FPGA) for control, signal
processing, and event building.
†Condensed from the proceeding of XIII Nuclei in the Cosmos, 7-11 July,
2014, Debrecen, Hungary*1School of Physics and Astronomy, University of Edinburgh*2
STFC Rutherford Appleton Laboratory*3
STFC Daresbury Laboratory*4
School of Physical Sciences, University of Liverpool*5
RIKEN Nishina Centre*6
Department of Physics, University of Tokyo*7
School of Engineering and Mathematics, University of Brighton

As each FEE card runs a separate data acquisition system(DAQ), reading data from only 64 channels, dead-time issignificantly reduced compared to that in current generation
detectors dealing with high pixelation. Fig. 1 shows the full
AIDA assembly.
To study the response of the AIDA to implantation of heavyions, an in-beam test was conducted at the Radioactive Ion
Beam Factory (RIBF) at RIKEN. The test was conductedparasitically to the first SEASTAR campaign,3) placing the
AIDA at the F11 focal plane. In this test configuration,
AIDA comprised one DSSSD type BB18 with a thicknessof 1 mm and featuring 128 strips with a 0.625 mm pitch inboth the x and y directions. Our test demonstrated thecapability of AIDA to detect position and energy of fast
fragment beams, as shown in Fig. 2.
With promising progress being made on all fronts, theAIDA is planned for use at the RIBF throughout 2015-2016
with two focuses: -decay half-life and decay spectroscopy
measurements using the EURICA -ray detector, andmeasurements of -delayed neutron emission probabilities
as part of the BRIKEN collaboration.

Fig. 2: Spectrum of energy measured using the front andback strips of AIDA’s DSSD for fragments around 78Ni, forevents in coincidence with a veto scintillator in the front
AIDA.
References

1) http://www2.ph.ed.ac.uk/td/AIDA/welcome.html
2) D. Braga, P. J. Coleman-Smith, T. Davinson, I. H. Lazarus,
R. Page, S. Thomas: ANIMMA 2nd International
Conference Proc., IEEE, (2011), pp. 1–5.
3) In this progress report- 247 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅱ-9. Instrumentation

CCJ operations in 2014
S. Yokkaichi,∗1 H. En’yo,∗1 T. Ichihara,∗1 and Y. Watanabe∗11Overview

The RIKEN Computing Center in Japan (CCJ)1)
commenced operations in June 2000 as the largest oﬀsite computing center for the PHENIX2) experimentbeing conducted at the RHIC3) . Since then, the CCJ
has been providing numerous services as a regional
computing center in Asia. We have transferred several
hundred TBs of raw data ﬁles and nDST a) ﬁles fromthe RHIC Computing Facility (RCF)4) to the CCJ.
The transferred data ﬁles are stored in a High Performance Storage System (HPSS)5) . A joint operation of
the CCJ with the RIKEN Integrated Cluster of Clusters (RICC)6) is continued since July 2009. HPSS anddedicated 20 PC nodes are maintained by them.
Many analysis and simulation projects are being carried out at the CCJ, and these projects are listed on the
web page http://ccjsun.riken.go.jp/ccj/proposals/.
As of December 2014, CCJ has contributed 31 published papers and 40 doctoral theses.
2

Computing hardware and software

In 2014, computing hardware (nodes and RAIDs)
and software (OS, batch queuing systems, databaseengine, and so on) were changed slightly from thosedescribed in the previous APR1) . In summary, we
have 28 computing nodes, two login servers, one main
server (users home directory, NIS, DNS, NTP), two
disk servers and HPSS machines in our machine room,and 20 computing nodes in the RICC room. In total, 524 jobs can be processed simultaneously by thesecomputing nodes.
One database (postgreSQL7) ) server and one AFS8)
server are operated in order to share the PHENIX computing environment (the other database server retiredin 2014). Sharing of the Scientiﬁc Linux9) 4 (SL4) environment was stopped in April 2014, and now only theSL5 environment is shared by the computing nodes,
which have approximately 0.9 TB of library ﬁles. We
have four data-transfer servers on which the grid environment10) is installed for the data transfer to/from
RCF. Two servers out of the four retired in Jan. 2015.
Disk failure occurred in March 2014, during a reboot after a planned power outage. File system of anusers work disk became corrupt and about 1.5 TB ofdata were lost in spite of adopting VxFS, a journalingﬁle system. Another trouble, namely, power outage at
the RAID due to the power failure on Wako Campus
in February, is thought to be an underlying cause of∗1
a)

RIKEN Nishina Centerterm for a type of summary data files in PHENIX- 248 -

the corruption of the ﬁle system. This has been themost serious accident at the CCJ so far, although it isdeclared that there are no backup of the disk.
Table 1 lists the numbers of malfunctioning SATA or
SAS disks in the HP servers, namely, computing nodes
and NFS/AFS servers.
Table 1. Number of malfunctioning HDDs in 2011-2014
Type
SATA
SAS

Size
1 TB
2 TB
146 GB
300 GB

Total
192
120
38
24

2014
11
0
2
1

2013
16
2
0
0

2012
20
5
1
0

2011
9
4
1
1

2.1 HPSS
The amount of data archived in the HPSS were approximately 1.73 PB (1.53 PiB) in 2.15 million ﬁles,as of December 2014, not so changed in 2014. No newdata ﬁle has been transferred in 2014, and therefore,
the data list in the previous APR1) is still eﬀective.
RICC will be upgraded to the “HOKUSAI” system,a new RIKEN computing cluster launched in April
2015, and HPSS will retire around August 2015. Data
migration to the new archiving system was performed
in Jan. 19 - Mar. 16 2015. The 863 TB (785 TiB) of
data in 1.66 million ﬁles out of 1.73 PB were migrated
to the new archiving system, because the raw data of
PHENIX, which were transferred for DST production
and already served out, were not migrated.
3

Prospect

The replacement of the main RAID and server ison-going, and should be completed in May 2015. The
batteries of the four UPSs have expired and should be
replaced in 2015. Regarding to the upgrade from RICC
to HOKUSAI, conﬁguration changes in the networkand job submitting environment are planned in theﬁrst half of 2015.
References
1) Y. Ikeda et al.: RIKEN Accel. Prog. Rep. 47, 237(2014).
2) http://www.phenix.bnl.gov/3) http://www.bnl.gov/rhic/4) https://www.racf.bnl.gov/5) http://www.hpss-collaboration.org/
6) http://accc.riken.jp/ricc/7) http://www.postgresql.org/
8) http://www.openafs.org/
9) http://www.scientificlinux.org/
10) http://www.globus.org/toolkit/docs/latest-stable/
gridftp/

Ⅱ-9. Instrumentation

RIKEN Accel. Prog. Rep. 48 (2015)

Computing and network environment at the RIKEN Nishina Center
T. Ichihara,∗1 Y. Watanabe,∗1 and H. Baba∗1
We are operating the Linux/Unix NIS/NFS cluster
systems1,2) at the RIKEN Nishina Center (RNC).
Figure 1 shows the current configuration of theLinux/Unix servers at the RNC. We have adopted Scientific Linux (SL), which is a clone of Red Hat Enterprise Linux (RHEL), as the operation system.
The host RIBF.RIKEN.JP is used as the mail server,
NFS server of the user home directory /rarf/u/, andthe NIS master server. This is the core server for the
RNC Linux/Unix cluster with approximately 600 registered user accounts. The hosts RIBF00/RIBF01 areused as SSH login servers to provide access to external
users, and as general-purpose computational servers,
printer servers, and gateways to the RIBF intranet.
An HP PloLiant DL-585 server was installed in 2006
as RIBF00 and this was replaced by DL-320e G8 in
January 2015. At the same time, the OS of RIBF00
was upgraded from SL 5.11 to SL 6.6.







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Fig. 2. Mail Trends: Message categories by PMX.

The data servers RIBFDATA02/03 and analysis
servers RIBFANA01/02/03 are mostly used to store
and analyze experimental data at RIBF. We have a
156 TB RAID system to store the experimental data
as /rarf/w and /rarf/d/, which is connected to RIBFDATA02/03. A 52 TB SAS-FC RAID was added to
RIBFANA02 for data analysis for the SAMURAI experiment in October 2014.
A new Web server RIBFWEB1 was installedin April 2014 as the official Web server of RNC
WWW.NISHINA.RIKEN.JP to replace the old Web
server RARFWWW, which was installed in 2005. The
RIBFWEB1 also serves another Web service with using a virtual host function of the Apache http server3) .
The hosts RIBFSMTP1/2 are the mail front-end
servers, and they are used for tagging spam mails andisolating virus-infected mails. The latest version of
the Sophos Email Protection-Advanced (PMX 6.2.1)
has been installed on these. Figure 2 shows the Mail
Trends by the PMX over 12 months in 2014. The orange bar indicates the number of spam mails blocked
by the IP blocker; approximately 55 % of the incoming
mails are blocked.
An anonymous ftp server, FTP.RIKEN.JP, is managed and operated at the RNC. Major Linux distributions, including Scientific Linux, Ubuntu, Debian,
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References
1) http://ribf.riken.jp/comp/2) T. Ichihara et al.: RIKEN Accel. Prog. Rep. 47, 236(2014).
3) http://httpd.apache.org/docs/2.2/en/vhosts/

Fig. 1. Configuration of the RIBF Linux cluster.
∗1

RIKEN Nishina Center- 249 -

III. RESEARCH ACTIVITIES II(Material Science and Biology)

1. Atomic and Solid State Physics (Ion)Ⅲ-1. Atomic & Solid State Physics (Ion)

RIKEN Accel. Prog. Rep. 48 (2015)

Hyperfine structure measurement of 133 Cs atoms in superfluid helium
K. Imamura,∗1,∗2 T. Furukawa,∗3 X. F. Yang,∗4 Y. Mitsuya,∗2 T. Fujita,∗5 M. Hayasaka,∗6∗2∗9
T. Kobayashi,∗7 A. Hatakeyama,∗8 H. Ueno,∗1 H. Odashima,
133 and Y. Matsuo

Hyperfine structure measurement of

Cs atoms in superfluid helium

∗5
∗6
∗7
∗8
∗9

LIF Intensity [count/bin]

LIF Intensity [count/bin]

LIF Intensity [count/bin]

LIF Intensity [count/bin]

nm)5) . In this experiment, several gauss of static magThe study of nuclear structure via laser spectroscopy
∗1,∗2
∗3
∗4
∗2
∗6
K. Imamura,
Furukawa,
X.
F. Yang,
Mitsuya,T.trappedFujita,∗5atoms
M. Hayasaka,
neticﬁeld wasY.applied
to theusing atechniques has contributed
to signiﬁcant T.
progress
in
∗7
∗8
∗1
∗2
∗9
T. Kobayashi,
A. Hatakeyama,
Ueno, H.
Odashima,
Y. polarization.
Matsuopair ofH.
Helmholtz
coils
to maintainand
spin
nuclear physics1) . To extend
the applicabilityofTo observe HFS resonance of Cs atoms, MW was irralaser spectroscopy techniques for the study of lowdiated to the spinpolarized
atoms andseveral
its frequency
yield exotic nuclei
rate is lessnm)5)
. In this Cs
experiment,
gauss of static mag
Thewhosestudy productionof nuclear structure
via thanlaser spectroscopy
was scanned.
The ﬁeld
emittedinducedﬂuorescence
100 pps, we havebeen developing
OROCHI(Optical progress
netic
waslaserappliedto thetrapped atoms using
techniques
has contributed
to signiﬁcantin1)(LIF) during
the scanningof MW
frequencies
wasspinde- polarization
RI-atom Observationin Condensed
pairof Helmholtz
coils
to maintain
nuclear physics. To Helium
extend as
theIonapplicabilityofusing aTophotomultipliertube. To suppress
strayMW was irra
catcher)2) . OROCHI
is based on
a combination
observe HFS resonanceof Cs atoms,
laser spectroscopy
techniques
for theofstudytectedof lowlightthan
from thediatedlaser beam,
the wavelength
LIF (892
superﬂuid heliumII)nuclei
as anwhoseeﬀective
stopper rate
for is lessto the spinpolarized Csofatoms
and its frequenc
yield (Heexoticproduction
5)high-energetic100
ion pps,beams
in beensitu laser
spectroscopy
was selectedusing a monochromator.
1 ﬂuorescenc
was scanned.
The emitted laserFigure
inducedweand
have
developing
OROCHI nm)(Opticalof atoms. InRI-atom
OROCHI,an energetic
beam prothe obtained
spectratheinscanning
this experiment.
We(LIF) duringof MW frequencies
was deObservationin ionCondensed
Heliumshows
as Ionduced at an accelerator
is directly
injected
can clearlyresonance
peaks in theﬁgure.
tected theusinga photomultipliertube.
To suppress stra
catcher)2) .facility
OROCHIis basedon ainto
combinationof observe
He II. The injectedions
are neutralized
the stopper
Since forthe resonancefrequencies
are shiftedby ZMS of LIF (89light fromthe laser beam,
the wavelength
superﬂuid
helium(He II) as during
an eﬀective
stopping process
and are trapped
as andisolated
atoms.
owing to the appliedmagneticﬁeld,thearesonancefrenm)5) was
high-energetic
ion beams
in situlaser spectroscopy
selectedusing
monochromator.
Figure
The trapped ofatoms
are subjected
to aancircularly
quencies
measuredboth cases
i.e.,in usingσ+atoms.
In OROCHI,
energeticpoion beampro- are shows
the forobtained
spectrathis experiment.
W−larized laser duced
light andto thespin ispolarized
and σinto
polarized
lasers. observe
The HFSCs atoms peaks
in He in the ﬁgure
at andriven
accelerator
facility
directly injected
can clearly
theofresonancestate. The Zeeman/hyperﬁnesplittings(ZMS/HFS)
II is calculated
by averaging
the twomeasured
He II. The injectedions areneutralized during
the
Since
the resonancefrequencies
areresoshifted by ZM
of atoms are stopping
measuredprocessusing aandlaser-RF/MW
frequencies.
obtainthe preliminary
value
are trapped(radioas isolatednanceatoms.
owingWeto theappliedmagnetic ﬁeld,
theofresonance frefrequency/microwave)
doubleresonance
method to
9 250.58(2)MHz
as theof Cs foratoms
in cases
He II.i.e., using σ
The trappedatoms
are subjected
to dea circularly
poquencies
areHFS
measuredboth−
duce nuclear spins
andlasermoments.
So far,a series
This result showsthe HFSlasers.
of Cs The
atoms
in He
II atoms in H
larizedlight anddrivento oftheex-spin polarizedand σthatpolarized
HFS
of Cs
periments using
the 84-87
is approximately% largerthan thatvacion beam have beenper- (ZMS/HFS)
state.
The RbZeeman/hyperﬁnesplittings
II is 0.63(2)calculated
by averaging
the intwomeasured resouum
owing tonancethe frequencies.
eﬀect of the We
surrounding
formed at theofRIKEN
Nishina
Center.
The
feasibilatoms aremeasuredusing
a laser-RF/MW(radioobtain thehelium.
preliminary value o
Thetoachieved
accuracy
6 digitsin theity of the principleof OROCHI hasdouble
been successfully
frequency/microwave)
resonance method
de9measurement250.58(2) MHz
as theis HFS
of Cs
atoms in He I
3)current
theshows
accuracy
HFS
demonstratedduceby measuring
the ZMSof 84-87 RbSo
. far,For a series
nuclear spins
and moments.
of ex-system.
ThisSince
resultthat ofthethe
HFS
of of
CsCs
atoms in He I
atoms
in He IIisisapproximately
limited owing to
the ﬂuctuation
the that in vac
further developmentof using
OROCHI,
it isRbindispensable
periments
the 84-87
0.63(2)% largerinthan
ion beam have been
perappliedﬁeld, ofit thecan surrounding
be imto ensure theformed
applicability
OROCHIfor themea- Theintensityuumowingmagnetic
to the eﬀect
heliumat the of
RIKEN
Nishina
Center.
feasibil- of theproved by oneTheor twoordersmeasurementof magnitude accuracy
by installing
surement of HFS
atoms
in He ofII. OROCHI
In particular,
the successfully
achieved
is 6 digits in th
ity ofoftheprinciple
has been
3)
stabilized
supplyfor theSince
magneticﬁeld. Inofthefollowing two demonstrated
issues have to beHow
the of
He84-87 Rb
current
system.
the accuracy
the HFS of C
by conﬁrmed
measuringi)theZMS. For power
near feature, wewillinconduct
measurement
II environmentaﬀectsdevelopment
the HFS of an
atoms
He II issystematic
limited owing
to the ﬂuctuation in th
furtherof introduced
OROCHI, atom,
it is indispensable
84-87
of HFSand ii) What tois ensurethe highest
level of measurementac- for the
Rb toofdemonstratefeasibility
the applied themagneticﬁeld,ofit can be im
the applicabilityof OROCHI
mea-using intensity
curacy that canbe achieved.
theII.above
OROCHI
the studyof low-yield
exoticofnuclei.
by oneor two orders
magnitude by installin
surementof HFSToofinvestigate
atoms in He
In particular,
the for proved
mentioned issues,
we conducted
an experimentusingi) How the Hestabilized power supply3 for the magnetic ﬁeld. In thfollowing
two issues haveto be conﬁrmed
10
103
133
Cs atoms thatare introduced
into
II using
thenear feature, we will
II environmentaﬀectstheHe
HFSof an introduced
atom,
5.5 conduct systematic measuremen+ pumping84-87
σlaser ablationand
technique.
of HFS usingii) What is the highest level of measurement
acRb todemonstrate the feasibility oσ- pumping11 (F, m )=(4, +4) (3, +4))=(4, +4) (3,+4)
The experimental
setup
to theone incuracy thatcanisbesimilarachieved.
To investigate
the above F OROCHI for the study(F,ofmFlow-yield
exoticnuclei.
ref.[4]. An open-topped
quartz we
cubic
cell (70 ××mentioned issues,
conducted
an70
experiment
using
4.5
103
103
70 mm3 ) ﬁlled133withHe II liquidwasintroduced
placed inside
Cs atoms
that areintotheHe II using9 the5.5
σ+ pumping
cryostat. A solid
was placed
approximately 1 cm
laserCsCl
ablationtechnique.
σ- pumping11 (F, mF)=(4, +4) (3, +4)(F, mF)=(4, +4) (3, +4
above the liquidThesurface.
In this experiment,
atomsto the one
experimental
setup is Cs
similar
in
7
3.5
4)
were introduced
into AnHe open-topped
II using two quartz
pulsed cubic
laserscell. (70 × 70 ×
ref.[4].
4.5
39242.3 9242.5 9242.7 9242.9
9
The introduced
into the70 Cs
mmatoms) ﬁlledwere
withpumped
He II liquid
was spinplaced inside 9258.5
the
9258.9
9258.7
Frequency [MHz]
polarized stateusing circularly
polarized
laser approximately
tuned
cryostat.
A solid CsCl
was placed
1 cm Frequency [MHz]
Fig.atoms
1. Observed spectra in this experiment. (a) when usto the D1 transitionof Cs
atomsIninthis
Heexperiment,
II (876
above thelineliquidsurface.
Cs7
3.5
ing 4)
thewere introduced into He II using two pulsed lasers. σ + pumping laser. (b) when using the σ − pump∗1 RIKEN Nishina Center
9242.3 9242.5 9242.7
laser.
introduced Cs atoms were pumped into theing
spin9258.5
9258.9
9258.7
∗2 DepartmentTheof Physics, Meiji University
Frequency [MHz]
Frequency [MHz]
state
using
circularly
polarized
laser
tuned
∗3 Departmentpolarized
Referencesof Physics, Tokyo Metropolitan University∗4 School of Physics,
Fig.
in thisexperiment.
to thePeking
D1 transition
Cheal and
K.1.T.Observed
Flanagan:spectra
J. Phys.
G Nucl.
Partic. (a) when u
University line of Cs atoms in He1)IIB.(876

Department of Physics, Osaka University
ing the σ + pumping laser. (b) when using the σ − pump37, 113101 (2010).
Department∗1of Physics,
Tokyo Gakugei
RIKEN Nishina
Center University
2) T. Furukawa eting
al.:laser.
Hyp. Interact. 196, 191 (2010).
∗2 for
RIKEN Center
AdvancedofPhotonics
Department
Physics, Meiji University
3) X. F. Yang References
et al.: Phys. Rev. A 90, 052516 (2014).
∗3
Department of Applied
Physics,
Tokyo Tokyo
Universityof Agri- University
Departmentof Physics,
Metropolitan
4) T. Furukawa
Phys.
Rev.
96, 095301(2006).G Nucl. Parti
culture and ∗4
technology
1)etB.al.:
Cheal
and
K. Lett.
T. Flanagan:
J. Phys.
School of Physics, Peking University
5) T. Kinoshita et37,
al.:113101
Phys. (2010).
Rev. B 49, 3648 (1994).
Department∗5of Advanced
Sciences,
HoseiOsaka
University
Departmentof Physics,
University∗6 Department of Physics, Tokyo Gakugei University
2) T. Furukawa et al.: Hyp. Interact. 196, 191 (2010).
∗7 RIKEN Center for Advanced Photonics
3) X. F. Yang et al.: Phys. Rev. A 90, 052516 (2014).
∗8 Department of Applied Physics, Tokyo University of Agri4) T. Furukawa et al.: Phys. Rev. Lett. 96, 095301 (2006
culture and technology- 251 ∗9 Department of Advanced Sciences, Hosei University
5) T. Kinoshita et al.: Phys. Rev. B 49, 3648 (1994).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-1. Atomic & Solid State Physics (Ion)

-V22H
H††
Lattice
Lattice location
location andand density
density distribution
distribution ofof hydrogenhydrogen inin bb11-V*1,*2
E.
E.Yagi,Yagi,*1,*2
T.
T.Hayashi,
Hayashi,*2*2T.
T.Yoshida,
Yoshida,*2*2S.
S.Koike,
Koike,*3*3N.
N.Higami,
Higami,*2*2K.Hirabayashi,
K.Hirabayashi,*2*2A.
A.Takebayashi,
Takebayashi,*2*2H.
H.Matsuba,
Matsuba,*2*2and
and
*1
*1
K.
K.Ogiwara
OgiwaraOn
On thethe atomistic
atomistic state
state ofof hydrogenhydrogen inin VV22H,
H, itit has
has beenbeenreportedreported thatthat hydrogenhydrogen atoms
atoms areare distributed
distributed randomly
randomly atat
tetrahedral
tetrahedral (T)(T) sites
sites inin thethe aa-phase-phase with
with aa bcc
bcc crystal
crystalstructure
structure atathighhigh temperaturestemperatures above
above about
about 470
470 K,
K, whereas
whereasinin thethe low-temperature
low-temperature bb11-phase-phase below
below about
about 450450 K,
K, theythey
occupyoccupy specificspecific octahedral
octahedral (O(Ozz)) sites
sites with
with anan ordered
orderedarrangement.
arrangement.1)1) The
The bb-V
H has
has two
two different
different crystal
crystal-V22H
structures,
structures, aa body-centred
body-centred tetragonal
tetragonal (bct)(bct) structure,
structure, andand aabody-centred
body-centred monoclinic
monoclinic one
one (bcm)(bcm) with
with slightslight inclination
inclinationofof thethe c-axis
c-axis(( aa00 ≈≈90
90.3.3--91
91  )) (a(a pseudo-tetragonal
pseudo-tetragonal
1)1)structure),
structure), both
both ofof whichwhich have
have anan axial
axial ratio
ratio between
betweena-and
a-and c-axes
c-axes cc00 aa00 ≈≈11.1.1, , depending
depending onon thethe condition
condition forforcrystalcrystal growth.
growth.1)1) When
When tensile
tensile stressstress isis applied
applied along
along thethe[001]
[001] axis
axis during
during transformationtransformation fromfrom thethe aa toto bb11-phases,-phases,thethe VV22HH crystallizes
crystallizes into
into thethe bct
bct structure,
structure, while
while without
without
tensiletensile stressstress itit crystallizes
crystallizes into
into thethe bcmbcm structure.
structure. The
The OOzz
sites
sitesareareoctahedral
octahedral(O)(O)sitessitesbetween
betweentwo
twoadjacentadjacentVVatoms
atoms
alignedaligned along
along thethe c-axis
c-axis (z-axis)(z-axis) (Fig.1).
(Fig.1). The
The changechange ofofhydrogenhydrogen site
site fromfrom TT toto OOzz sites
sites implies
implies thatthat thethe OOzz-site-site
occupancy
occupancyisis stabilizedstabilized bybyelongation
elongation ofof thethe c-axis,
c-axis, which,which,
conversely,
conversely,has
hasbeenbeeninduced
inducedby
byforces
forcesexerted
exertedby
byhydrogenhydrogenatoms
atoms onon neighbouringneighbouring VV atoms.
atoms. The
The mechanism
mechanism ofofoccurrence
occurrenceof
ofthe
thebctbctstructure
structureandandthetheOOzz-site-siteoccupancy
occupancyininthethe bb11-phase-phase waswas theoreticallytheoretically studiedstudied forfor thethe uniform
uniform
elongation
elongation ofof thethe c-axis
c-axis under
under thethe condition
condition ofof constantconstant
volume,volume, andand itit was
was proposed
proposed thatthat thethe elongation
elongation ofof thethe))c-axisc-axisisiseffective
effectivefor
for thetheOOzz-site-siteoccupancy.
occupancy.22 Therefore,
Therefore, totoexamineexamine this
this effectiveness,
effectiveness, inin thethe present
present study,
study, thethe sitesite
occupancy
occupancy ofof hydrogenhydrogen inin both
both tetragonal
tetragonal bb-V
H and
and
-V22H
monoclinic
monoclinicbb-V
Hisistotobe
beinvestigatedinvestigatedinindetail.
detail.
-V22H
Another
Anotherfundamental
fundamental problem
problemon
onhydrogenhydrogenisisthethedensity
density
distribution
distribution ofof hydrogenhydrogen aroundaround its
its occupation
occupation site.
site. ThisThis
problemproblem isis related
related toto thethe extent
extent ofof wavewave function
function ofofhydrogen.
hydrogen. Experimental
Experimental values
values hitherto
hitherto reported
reported byby aa
neutronneutron diffraction
diffraction method
method forfor thethe tetragonal
tetragonal bb-V
H are
are
-V22Hlargerlargerthan
thanthethetheoreticallytheoreticallycalculated
calculatedvalues
valuesand,and,therefore,
therefore,
3,4)
there
therehas
hasbeenbeenaalarge
largediscrepancy
discrepancybetween
betweenthem.
them.3,4)In
In orderorder toto clarify
clarify thethe sitesite occupancy
occupancy andand thethe spatial
spatialdensitydensitydistribution
distribution ofofhydrogen,hydrogen, thethe channelling
channellingmethod
method isisvery
very useful.
useful. In
In thethe present
present study,
study, thethe channelling
channelling method
methodutilizing
utilizingaanuclear
nuclearreaction
reaction11H(
H(1111B,B,aa))aa
aawithwithaa1111BBbeam
beamofofanan energy
energy ofof about
about 22 MeV,
MeV, which
which had
had been
been developed
developed toto5,6)
locatelocatehydrogenhydrogendissolved
dissolvedin
inTa
Taand
andV,
V,5,6)
isisapplied.
applied.
The
The lattice
lattice location
location ofof hydrogenhydrogen andand its
its density
density
distribution
distributionin
inthe
thetetragonal
tetragonalbb11-V-V22H
Hsinglesinglecrystal
crystal††Condensed
Condensedfrom
fromthethearticle
articleininJ.J.Phys.
Phys.Soc.
Soc.Jpn.
Jpn.81,
81,044602
044602(2012)(2012)

＊1
＊1

RIKEN
RIKENNishina
NishinaCentre
Centre＊2＊2SchoolSchoolofofScience
ScienceandandEngineering,Engineering,Waseda
WasedaUniversity
University
Department
DepartmentofofPhysics
PhysicsII,
II,TokyoTokyoUniversity
UniversityofofScience
Science＊3＊3preparedprepared under
under tensile
tensile stressstress andand thethe monoclinic
monoclinic
bb11-V-V22H
H1.1
single crystal
crystal preparedprepared without
without tensile
tensile1.1 single
stressstress have
have been
been studiedstudied atat room
room temperature.
temperature. The
The
following
following results
results have
have been
been obtained.
obtained. In
In these
these crystals,
crystals, HH
atoms
atoms areare locatedlocated atat octahedral
octahedral (O)(O) sites
sites with
with different
different
distributions
distributions over
over OOxx, , OOyy, , andand OOzzsites.
sites. In
In thethe tetragonal
tetragonal
bb11-V-V22H,
H, about
about 80%
80% ofof thethe HH atoms
atoms areare locatedlocated atat OOzzsites,
sites,
about
about10%
10%of
ofthemthematatOOyysites
sitesandandabout
about10%
10%of
ofthemthematatOOxx
sites.
sites. In
In thethe monoclinic
monoclinicbb11-V-V22HH1.1
about 65%
65% ofof thethe HH
1.1, , about
atoms
atomsarearelocatedlocatedatatOOzzsites,
sites,about
about 20%
20%of
ofthemthematatOOyysites
sites
and
andabout
about15%
15%of
ofthemthematatOOxxsites.
sites.These
Theseresults
resultssupport
supportthethetheoreticaltheoretical prediction
prediction thatthat hydrogenhydrogen preferentially
preferentiallyoccupies
occupies
OOzzsites
sitesunder
undertensile
tensilestressstressalong
alongthethez-axis
z-axis(c-axis).
(c-axis).
In
In bothboth crystals,
crystals, thethe HWHM
HWHM ofof thethe density
densitydistribution
distributionofofhydrogenhydrogenisisabout
about 0.35
0.35 ÅÅininthe
the[100][100]direction,
direction,whereas
whereasitit isis lessless than
than 0.13
0.13 ÅÅ inin thethe [001][001] direction
direction on
on thetheassumption
assumptionof
ofthe
theGaussian
Gaussiandistribution.
distribution.The
TheHWHM
HWHMin
inthe
the
[110]
[110] direction
direction has
has been
been measured
measured only
only inin thethe tetragonal
tetragonal
crystalcrystal to
to be
be about
about 0.35
0.35 Å.
Å. These
These values
values areare muchmuch smaller
smallerthan
than those
those hitherto
hitherto obtained
obtained byby thethe neutron
neutron diffraction
diffraction
method,method, andand close
close totothe
the values
values theoreticallytheoreticallycalculated
calculated forforthethegroundgroundstate
state(~0.28(~0.28ÅÅfor
forthethe[100][100]direction
directionand
and~0.093~0.093ÅÅforforthethe[001][001]direction).
direction).

Fig.1.
Fig.1.Two
Twokinds
kindsofofTTsites,
sites, TT11and
andTT22, ,and
andthreethreekinds
kindsofofOO
sites,
sites, OOxx. . OOyy andand OOz,z, inin thethe bct
bct structure.
structure. For
For eacheach type
type ofof
site,
site,only
onlysome
someofofequivalentequivalentsites
sitesareareindicated.
indicated.
References
References

1)
1)For
Forexample:
example:J.J.Wanagel,
Wanagel,S.S.L.
L.Sass,Sass,and
andB.
B.W.
W.Batterman:
Batterman:Phys.
Phys.
Stat.
Stat. Solidi
Solidi AA 10,
10, 4949 (1972);(1972); H.
H. Asano,
Asano, Y.Y. Abe,
Abe, andand M.
M.
Hirabayashi:
Hirabayashi: J.J. Phys.
Phys. Soc.
Soc. Jpn.
Jpn. 41,
41, 974974 (1976);(1976); Y.
Y. Noda,Noda, K.
K.
Masumoto,
Masumoto, S.S. Koike
Koike T.T. Suzuki,
Suzuki,andand S.S. Sato:
Sato:Acta
Acta Crystallogr.,
Crystallogr.,
Sect.
Sect.B42,
B42,529529(1986).
(1986).
2)2)H.
H.Sugimoto:Sugimoto:J.J.Phys.
Phys.Soc.
Soc.Jpn.
Jpn.53,53,25922592(1984).
(1984).
3)
3) T.T. Kajitani
Kajitani andand M.
M. Hirabayashi:
Hirabayashi: Z.
Z. Phys.
Phys. Chem.
Chem. NF
NF 145,145, 27
27(1985).
(1985).
4)4)H.
H.Sugimoto
Sugimotoand
andY.
Y.Fukai:
Fukai:J.J.Phys.
Phys.Soc.
Soc.Jpn.
Jpn.51,
51,25542554(1982).
(1982).
5)5) E.
E. Yagi,Yagi, T.T. Kobayashi,
Kobayashi, S.S. Nakamura,
Nakamura, Y.
Y. Fukai,
Fukai, andand K.
K.
Watanabe:
Watanabe:J.J.Phys.
Phys.Soc.
Soc.Jpn.
Jpn.52,
52,34413441(1983).
(1983).
6)6) E.
E. Yagi,Yagi, T.T. Kobayashi,
Kobayashi, S.S. Nakamura,
Nakamura, Y.
Y. Fukai,
Fukai, andand K.
K.
Watanabe:
Watanabe:Phys.
Phys.Rev.
Rev.BB31,
31,1640
1640(1985).
(1985).

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Ⅲ-1. Atomic & Solid State Physics (Ion)

RIKEN Accel. Prog. Rep. 48 (2015)

Observation of the FFLO-like nodal planes in the Au layer of
Nb/Au/Fe trilayers by neutron reflectivity measurements
H. Yamazaki,＊1 M. Kubota,＊2 N. Miyata,＊3 and M. Takeda＊2
In order to clearly show the changes in reflectivity whenmeasurement conditions were changed, the reflectivity
ratios log(R1/R2) were plotted as a function of Q in Fig. 2:[R(2.3 K, 2 kOe)/R(2.3 K, 0 kOe)], [R(2.3 K, 2 kOe)/R(10K, 2 kOe)], [R(2.3 K, 0 kOe)/R(10 K, 0 kOe)], and [R(10 K,
2 kOe)/R(10 K, 0 kOe)] for (1) (S, H≠0)←(S, H=0), (2) (S,H≠0)←(N, H≠0), (3) (S, H=0)←(N, H=0), and (4) (N,H≠0)←(N, H=0), respectively. The base lines are shifted
arbitrarily for clarity of comparison. The variations inlog(R1/R2) are qualitatively the same as those obtained in
the previous measurements.
At high Q’s in Fig. 2, regular and periodic peaks areobserved particularly for (1) and (2) with an interval of 0.4
nm-1 (shown as broken lines). This interval corresponds to aperiod of 15.7 nm in real space. Low-noise data acquired inthis experiment allow for the resolution of these peaks. At
present, the origin of the 15.7 nm period is not clear. The
thickness of the Fe layer is 12.6 nm, and we can observe a
peak at 0.5 nm-1 that corresponds to a thickness of 12.57 nm,
reflecting a magnetic change in the Fe layer. For moreelaborate analysis, we have to carry out reflectivity
simulation based on an appropriate multilayer model,
including magnetic components not only in Fe but also in
Au. The intense peak at 3.2 nm-1 for (1) and (2), however,may prove the existence of the FFLO-like nodal planes in
the Au layer.

1 (S, H =0) ← (S, H =0)log (R1/R2)

From the study of Nb/Au/Fe and Nb/Au/Co trilayers,1, 2)
it was suggested that the superconducting order parameter Δ
shows an FFLO-like oscillation with a period of Λ~2.1 nm
in the Au layer probably due to the existence of strong
spin-orbit coupling. In order to observe the oscillation in Δ,
we carried out neutron reflectivity measurements on atrilayer of Nb(28.8nm)/Au(10.4nm)/Fe(12.6nm) with a capof Au(4.4nm). For a review on the FFLO (or LOFF) states,
please see ref. 3.
The Nb layer shows superconductivity below Tc~8.0 K,
whereas the Fe layer is ferromagnetic. Below Tc, the Au
layer is supposed to be in a superconducting state due to aproximity effect of the Nb layer. For the observation of
possible FFLO-like nodal planes, where paramagnetic
moments will appear when a magnetic field is applied
neutron reflectivity
perpendicular to the planes,4)measurements were performed for 0.07<Q<6 nm-1 at BL17
(Sharaku) in J-PARC/MLF. Measurements were firstcarried out at [10 K, 0 kOe], and then the sample wascooled to 2.3 K under zero magnetic field (|H|<0.1 Oe) toachieve a superconducting state. Measurements werecarried out in sequence as shown in Fig. 1: [2.3 K, 0
kOe]→[2.3 K, 2 kOe]→[10 K, 2 kOe]. The data wereobtained under four different conditions: (N, H=0) a normal
state without field, (S, H=0) a superconducting state without
field, (S, H≠0) a superconducting state with an applied field,and (N, H≠0) a normal state with an applied field.
The reflectivity obtained as a function of Q was inexcellent agreement with previous results (Project No.
2012B0139). In the present experiment, we wereparticularly interested in the reflectivity at high Q’s. To
improve the S/N ratio, the signal was accumulated for alarger number of counts than in the previous measurements.

2 (S, H =0) ← (N, H =0)

3 (S, H =0) ← (N, H =0)

H

4

T

Magnetic Field (kOe)5sample plane

4 (N, H =0)← (N, H =0)3

Hc2(T )

Superconducting
State

1

Normal Statezero-field cooling

0

2
4
6
8 10
Temperature (K)Fig. 1. Conditions for the measurements.
RIKEN Nishina Center
JAEA
＊3
CROSS
＊2

1

2

3

4

5

6

-1

Q (nm )

Fig. 2. Changes in neutron reflectivity.

2

0

＊1

0

References

1) H. Yamazaki, N. Shannon and H. Takagi: Phy. Rev. B 73,
094507 (2006).
2) H. Yamazaki, N. Shannon and H. Takagi: Phy. Rev. B 81,
094503 (2010).
3) R. Casalbuoni and G. Nardulli: Rev. Mod. Phys. 76, 263(2004).
4) Y. Matsuda and H. Shimahara: J. Phys. Soc. Jpn. 76, 051005(2007).

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-1. Atomic & Solid State Physics (Ion)

Response of polyimide films to U ion beams as etched-track detectors
T. Yamauchi,＊1 T. Kusumoto,＊1 K. Matsukawa,＊1 Y. Mori,＊1 M. Kanasaki,＊1 K. Oda,＊1 S. Kodaira,＊2 K. Yoshida,＊3
Y. Yanagisawa,＊3 T. Kambara,＊3 and A. Yoshida＊3
Figure 1 shows typical growth curves of etch pit radius r
against the thickness of layer removed G for U ions andother indicating heavy ions. During the etching, the films
were reduced in thickness by 2G. With increasing energy ofU ions, the fitted slope for each data set decreases. The
observed linear relation allowed us to use the conicalassumption in evaluating the etch rate ratio V, which is theratio of the track etch rate Vt to the bulk etch rate Vb. 7) The
etch rate ratio was assessed by the following relation:(1)
V={1+( dr/dG)2} /{1-( dr/dG)2}
where (dr/dG) is the slope of the fitted line. The sensitivityof etch pit formation is defined as V-1. Figure 2 indicatesthe sensitivity of U ions, as well as other heavy ions, as afunction of the stopping power. The threshold of U ions foretch pit formation is 3,439 keV/µm, which is higher thanthat of other heavy ions. The threshold is also observed in
the growth curve (Fig. 1), as the intersect of the fitted line
for 337.6 MeV/n U ions with a depth of 1.88 µm.
101

Sensitivity

The polyimide Kapton retains its excellent physical,
electrical, and mechanical properties over a wide
temperature range between 4 and 673 K, and hence, it isconsidered an attractive candidate for a nuclear track
membrane. Size-controllable nuclear pores on the
sub-micron scale have been fabricated in the polyimide
films by chemical etching, subsequent to irradiation withheavy ions.1-3) Such nuclear membranes have been used in
nanopore membranes, templates for metallic nanowires,aerosol filters, and gas separation films.4-6) Applicability ofthe polyimide films as etched-track detectors for researchon ultra-heavy cosmic rays has also been suggested; in thiscase, relatively long etchings are performed prior to thesurface observations on the micron-scale under optical
microscopes.7) Few studies have been carried out, however,on the response of the polyimide for U ions, even as
fundamental studies,8,9) different from that on polyethylene
terephthalate.10) In this report, we describe the first result on
the detection threshold and sensitivity of Kapton for U ions.
Commercially available Kapton films (from Nilaco) witha thickness of 125 µm were stacked and exposed to 345
MeV/n U-238 beams in air at the port of BigRIPS(F12),
covering the stopping powers up to 20,000 keV/µm. Afterthe exposure, the films were etched in a sodium
hypochlorite solution kept at 55˚C.

7Etch pit radius, r (m)

6

(2.3 MeV/n)

5U(17.1 MeV/n)(14.7 MeV/n)

43439 keV/µm
10-23(3.5 MeV/n)

1.88 µm

2
1
0

103

(3.7 MeV/n)

U(337.6 MeV/n)
0

2

4

6

8

10

12

References

14

Fig. 1. Etch pit growth curves for U ions (14.7, 17.1 and
337.6 MeV/n), Xe ions (2.3 MeV/n), Kr ions (2.5 MeV/n),
Si ions (3.5 MeV/n), and Al ions (3.7 MeV/n). Each energy
for other indicating ions is close to that of the Bragg peaks.
Graduate School of Maritime Sciences, Kobe University
National Institute of Radiological Sciences＊3
RIKEN Nishina Center＊2

104

Stopping power (keV/m)

3x104

Fig. 2. Sensitivity of Kapton for U ions and other heavy
ions against the stopping power.

Thickness of layer removed, G (m)

＊1

U
10-1

U

(2.5 MeV/n)

1001) P. Vater: Nucl. Tracks Radiat. Meas. 15, 743 (1988).
2) C. Trautmann et al.: Nucl. Instr. Meth. B 111, 70 (1996).
3) R. Sudowe et al.: Nucl. Instr. Meth. B 175-177, 564 (2001).
4) W. Ensinger et al.: Radiat. Meas. 40, 642 (2005).
5) W. Ensinger et al.: Surf. Coatings Technol. 201, 8442 (2007).
6) W. Ensinger et al.: Radiat. Phys. Chem. 79, 204 (2010).
7) T. Yamauchi et al.: Appl. Phys. Exp. 6, 046401 (2013).
8) C. Trautmann et al.: Nucl. Instr. Meth. B 116, 429 (1996).
9) S. A. Saleh and Y. Eyal: Nucl. Instr. Meth. B 208, 137 (2003).
10) D. Drach et al.: Nucl. Instr. Meth. B 28, 46 (1987).

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Ⅲ-1. Atomic & Solid State Physics (Ion)

RIKEN Accel. Prog. Rep. 48 (2015)

High-density
High-density
High-density
n-typen-typen-typedopingdopingdopingof diamondofof diamonddiamondby nitrogenbyby nitrogen
nitrogen
beam
beam
beam
implantation
implantation
implantation
∗1
∗1 ∗2
∗2,∗3
∗2,∗3
∗1,∗4
∗1,∗4
∗1
∗1
∗1
∗1
∗1
∗1
∗1,∗5
∗1,∗5
∗1,∗5
H. Ueno,H.
H.∗1Ueno,
Ueno,
R. Kato,R.
R.Kato,Kato,
H.M.∗2∗2Yamamoto,
H.M.
H.M.Yamamoto,
Yamamoto,A.∗2,∗3
Yoshimi,A.
A.Yoshimi,
Yoshimi,K.∗1,∗4
Morimoto,
K.
K.Morimoto,
Morimoto,
Y. Ichikawa,Y.
Y.Ichikawa,
Ichikawa,
Y. Ishibashi,
Y.
Y.Ishibashi,
Ishibashi,
∗1,∗6
∗1,∗6
∗1,∗6
∗1,∗6
∗1,∗6
∗1,∗6
Y. Ohtomo,Y.
Y.Ohtomo,
Ohtomo,and T. andSuzukiandT.
T.SuzukiSuzukiAfter the
After
After
discoverythethe discovery
discoveryof the ofof
superconductivity
thethe superconductivity
superconductivityofnealing
ofof
nealing
nealing
processprocessprocess
to make
to
tothe
make
make
diamondthethe diamonddiamondlattice latticeaslatticeclean
asas clean
clean
1)
1)
1)
boron-doped
boron-doped
boron-doped(p-type)(p-type)(p-type)diamonddiamonddiamondin 2004in
in,20042004
as possible
asaspossible
possibleshould shouldbeshouldalsobebeinvestigated.
also
alsoinvestigated.
investigated.
studies, ,studies
havestudieshave
have
In
Inthe
thepresent
present
work, we
work,
work,
reportwewereportonreportthe on
ﬁrst
onthe
the
nitrogenﬁrst
ﬁrstnitrogennitrogenbeen extensively
beenbeenextensively
extensively
conducted
conducted
conducted
to raiseto
to
the
raise
raise
Tc of
the
the
TTccofofdiamonddiamonddiamondIn the present
a)
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a)
ion
ion
ionimplantation
implantation
experimentexperimentexperiment
at RIBF
at
at
RIBF
RIBF
superconductivity.
superconductivity.
superconductivity.
These studies
These
Thesestudies
havestudies
indicatedhave
haveindicatedindicatedthat a thatthat
aa implantation
to investigate
totoinvestigate
investigateaaahigh doping
highhighdoping
concentration
dopingconcentration
concentrationof boronofofisboron
boron
favorable
isisfavorable
favorable
for in- forforininpossible
possiblepossibleonset ofonset
onset
n-typeofofn-type
superconductivity
n-typesuperconductivity
superconductivityof diamond.
ofofdiamond.
diamond.
14 3+ 14
14 3+
creasing
creasing
creasing
the Tc ofthetheTTccofofsuperconductivity.
A beam
AA of
beam
beam
superconductivity.
superconductivity.
High doping
High
Highdoping
condopingconconN ofof delivered
NN3+ delivereddeliveredat energy
at
at energy
energyE/A =E/A
E/A
450 == 450
450
centration
centration
centration
can be cancanintroducedbebe introduced
introducedby the bychemical-vaporby thethe chemical-vaporchemical-vaporkeV fromkeV
keVthe
from
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the RILAC
RILAC
accelerator
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at RIBF
at
at was
RIBF
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was imim2,3)
2,3)
2,3)
deposition
deposition
deposition(CVD)(CVD)(CVD)
methodmethod
methodplantedplanted
plantedinto (100)-faceted
into
into(100)-faceted(100)-faceted
single crystals
singlesinglecrystals
crystalsof typeofIb
oftypetype
di- Ib
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Basedthisonontechthis
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amond
amond
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wasenergysetwas
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lower
far
hasreachedso
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11.4
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at K
dopingK4)4) at
at dopingcondoping conconc has Tso
21
21
21
−3
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than thethan
than
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the
theCoulomb
Coulomb
barrier barrier
tobarrier
avoid
to
tothe
avoid
avoid
radioactivaion
thetheradioactivaion
radioactivaion
centration
centration
centration
ρ =8.4×10
ρρ =8.4×10=8.4×10
cm−3
. cm
cm
Theoretically,. . Theoretically,
Theoretically,it has itit has
has
of samples.
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samples.
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crystals
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been predicted
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×× 4×
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mm
0.3 mm(t),×× 0.3
0.3 mm(t),mm(t),and mounted
andand mounted
mountedon a onon aa
Tc ≥ 100
TTcc ≥
K≥100
is100
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KKisispossible
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fordopeddiamonddopeddiamonddiamond, because, , because
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targetthe highthethephononhighhighphonon
phononfrequency
frequency
frequencyof diamond
ofofdiamonddiamondis favorable
isisfavorable
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chamber.
chamber.
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The implantation
implantation
was carried
waswas carried
carriedout at out
roomout atat roomroom
increasing
increasing
increasing
the Tc the
TTccofofsuperconductivity.
ofthe
superconductivity.
superconductivity.
temperaturetemperaturetemperature
at beamat
atcurrent
beambeamcurrent
current
I = 3 ∼II10==3µA.
3∼∼10
10µA.
µA.
Unfortunately,
Unfortunately,
Unfortunately,
the dopingthethedopingconcentration
dopingconcentration
concentrationachievableachievableachievable
14
14
14
22
−3
22
22
−3
The
The density
densityρ(14 N) ρ(ρ(1414theby CVDbybyisCVD
CVD
limitedisis limited
limitedto less to
to
than
less
lessρthanthan= 10ρρ
==cm
10
10
of
N)
N) of
implantedof thethe implanted
implanted
N particles
NN particles
particles
for
cm
cm−3
for
forThe density
20
−3
20
20
−3
−3
was simply
waswassimply
calculated
simplycalculated
calculatedbybybyboron and,
boron
boron
more
and,
and,
seriously,
moremoreseriously,
seriously,ρ = 10 ρρ==10
10 forcm
cm
cm
phosphofor
forphosphophosphorus (n-type).
rus
rus(n-type).
(n-type).
With higher
With
Withhigher
concentration,higherconcentration,
concentration,
the dopants
thethedopants
dopants
I · T II· ·TT
are known
areareknown
toknown
formtotodimers,form
formdimers,
dimers,causingcausing
causing
localization
localization
localizationof the ofofthetheρ(14 N) ρ(ρ(1414N),,(1)=N)== ,(1)(1)
qq· ·SS· ·∆R
q · S · ∆R∆R
doped doped
carriers,
doped carriers,
carriers,
and thus
andandcannotthus
thus cannot
cannotbe usedbe
befor
used
used
electric
forfor electric
electric
conduction.
conduction.
conduction.
In viewInIn
ofviewview
electronic
ofofelectronic
electronic
applications,applications,applications,both p-bothbothwhere
p-pwhere
II isbeam
beam
TT isirradiation
Iwhereis theis thethe current,
beam current,
current,
T is theis thethe irradiation
irradiation
type andtype
type
n-typeandandn-type
dopingsn-typedopings
dopings
are necessary.
arearenecessary.
necessary.
From anFrom
Fromanalanananalanal==the33++ charge
time, qtime,time,= 3+qq is
isis thethe chargestatechargeofstate
state
the ofbeam,of thethe beam,
Sbeam,≃ SS ≃≃
ogy to other
ogy
ogyto
to
superconductors
otherothersuperconductors
superconductors
such assuch
high-Tsuchasaschigh-T
high-T
cuprates,
cuprates,
π×4 mm×6.5π×4π×4 mm×6.5
mm×6.5mm is mmthemmbeamisis thethespot
beam
beam
size,
spot
spot
and
size,
size,
∆R
and
and
is ∆R
∆R isiscccuprates,
it is natural
ititisisnatural
naturalto expecttotoexpectn-typeexpectn-type
superconductivity
n-typesuperconductivity
superconductivity
in dia- inindiadiathe stopping-range
thethe stopping-range
stopping-range
distribution
distribution
distributionof the ofbeamof thethe inbeam
beam
the inin thethemond. mond.
To
mond.
date,
To
To
however,date,
date,however,
however,high-density
high-density
high-density
doping dopingof
dopingn-typeofofn-typen-typecrystal.crystal.
crystal.
TakingTaking
Takinga valueaaof
value
value
∆R ofof≃∆R∆R
0.2 ≃µm
≃ 0.2
0.2
at µm
µm
the atat thethecarrier carrier
hascarriernothas
has
been
not
not
achieved.
been
beenachieved.
achieved.
mean stoppingmean
mean stopping
stopping
range R
range
range
≃ 2.5
RR ≃
µm,
≃ 2.5
2.5
calculatedµm,µm, calculated
calculatedwith withwith
7)
A newAA
approachnewnew approach
approach
expected
expected
expected
to realizetoto realize
high-density
realize high-density
high-density
the simulationthethe simulation
simulation
code SRIM
code
code7)SRIM,SRIM
we 7)determined, , wewe determined
determinedρ(14 N) ρ(ρ(1414N)N)
doping doping
dopingis heavy-ion
isis heavy-ion
heavy-ion
implantation,
implantation,
implantation,
becausebecause
becausei) a sharpi)i) aa sharp
sharp
of ﬁve ofnitrogen-implantedof ﬁveﬁve nitrogen-implanted
nitrogen-implanted
diamonddiamonddiamondcrystals,
crystals,
crystals,
rangingranging
ranging
20
20
20
22
−3
22
22
−3
fall-oﬀ fall-oﬀ
atfall-oﬀ
the atdistalat thetheedgedistaldistalinedgeedge
the instopping
in thethe stopping
stopping
range (i.e.,
range
range (i.e.,(i.e.,
from ρ from=from
7.8ρρ×==
10
7.8
7.8
×
×10
10
to
1.9
×
to
to10
1.9
1.9
×
cm
×10
10
. cm
These
cm−3
. . densiThese
ThesedensidensiBragg peak),
Bragg
Braggpeak),whichpeak),becomes
which
whichbecomes
becomes
remarkableremarkableremarkablefor heavy-ion
forforheavy-ion
heavy-ionties areties
ties
approximately
areareapproximately
approximately
the samethetheassamesame
the reported
as
asthe
thereported
reported
CVD- CVDCVDbeams,beams,
isbeams,
favorable
isisfavorable
favorable
for the forpurposeforthethepurpose
purposeof high of
dopingofhighhighdoping
condopingconcondoped doped
boron
doped densities
boron
boron densities
densities
at whichatat superconductivity
which
which superconductivity
superconductivity
ofofof
1,4,8) 1,4,8)
1,4,8)
centration,
centration,
centration,and ii) anddopantandii)
ii)dopantdimerization
dopantdimerization
dimerization
should should
notshouldoc-notnotococdiamonddiamonddiamondhas beenhashasobserved
been
been observed
observed. Oﬄine. . Oﬄine
Oﬄine
resistivity
resistivity
resistivity
cur verycurcurfrequently
very
very frequently
frequently
becausebecause
becauseof the ofhighof thetherandomnesshighhigh randomness
randomness
measurements
measurements
measurementsof the obtained
ofofthetheobtained
obtained
nitrogen-doped
nitrogen-doped
nitrogen-doped
crystalscrystals
crystalsof the implanted
ofofthetheimplanted
implanted
atoms. atoms.
atoms.
TakingTaking
Takingthese advantages,
these
theseadvantages,
advantages,
wewe
wea functionasasasaafunction
functionof temperatureofoftemperaturetemperature
are in progress.
areareininprogress.
progress.
have been
have
have
conducting
been
beenconducting
conducting
doped-diamond
doped-diamond
doped-diamondstudiesstudies
instudiesorderininorder
order
to realizetoto realizeanrealizen-typeanan n-type
diamondn-type diamonddiamondsuperconductivity
superconductivity
superconductivity
with with
with
References
References
References
1) E.A.1)
1)
Ekimov
E.A.
E.A.Ekimov
Ekimov
et al.: Nature
etetal.:al.: Nature
428,
Nature
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428,
428,
(2004).
542
542(2004).
(2004).
Tc as highTTcc asas
ashighhighpossible.
asaspossible.
possible.
Furthermore,
Furthermore,
Furthermore,
it is also
ititisimporisalso
alsoimporimpor2) B.V.2)
2)
Spitsyn
B.V.
B.V.Spitsyn
etSpitsynal.: J.
etetCryst.
al.:al.: J.J.Growth
Cryst.
Cryst.Growth
Growth52, 21952,(1981).
52,219219(1981).
(1981).
tant totant
tant
reproducetoto reproduce
reproduce
the increase
thethe increase
increasein Tc inininboron-doped
TTcc inin boron-doped
boron-doped
3)
M.
Kamo
3)
3)
M.
M.
et
Kamo
Kamo
al.:
J.
et
et
Cryst.
al.:
al.:
J.
J.
GrowthCryst.
Cryst.
GrowthGrowth62,642
62,(1983).
62,
642
642(1983).
(1983).
p-type p-type
region,p-type region,
region,in particular,
inin particular,
particular,
outsideoutside
outsidethe CVD
thethelimit,
CVD
CVD limit,
limit,
4) H. Umezawa
4)4) H.
H.Umezawa
Umezawa
et al.: cond-mat
etetal.:al.: cond-mat
cond-mat
05033030503303
0503303(2005). (2005).
(2005).
under the
under
under
schemethethe scheme
schemeof heavy-ion
ofof heavy-ion
heavy-ion
implantation
implantation
implantation
utilizing
utilizing
utilizing5) T. Shirakawa
5)5) T.
T. Shirakawa
Shirakawa
et al.: etJ.
et al.:
Phys.
al.: J.J.Soc.
Phys.
Phys.
Jpn.
Soc.
Soc.
76,
Jpn.
Jpn.
014711
76,
76, 014711
014711the high
the
the
beam
high
highcurrent
beambeamcurrent
current
of various
ofofvarious
variousheavy ions
heavy
heavy
availableions
ionsavailable
available(2007). (2007).
(2007).
at the at
RIBF
at thethefacility.
RIBF
RIBF facility.
facility.
In parallel,In
In parallel,parallel,the optimizationthethe optimization
optimizationofofof6) Sumicrystal:
6)6) Sumicrystal:
Sumicrystal:
Sumitomo
Sumitomo
Sumitomo
ElectricElectricElectric
Industries,
Industries,
Industries,
Ltd., OsLtd.,
Ltd.,OsOsconditions
conditions
conditions
for heavy-ion
forforheavy-ion
heavy-ion
implantation
implantation
implantation
includingincludingincludingan an- anananan- aka, Japan.
aka,aka,Japan.
Japan.
∗1
∗2
∗3
∗4
∗5
∗6

7) J. Ziegler:
7)7) J.J.Ziegler:
Ziegler:
SRIM―SRIM
SRIM
The
stopping――The
Thestopping
stopping
and rangeandandofrange
range
ions ofin
ofionsionsinin∗1∗1 RIKEN
RIKEN
Nishina
RIKENNishina
CenterNishinaCenter
Centermatter,matter,
http://www.srim.org/
matter,http://www.srim.org/
http://www.srim.org/(2008). (2008).
(2008).
∗2∗2 Condensed
Condensed
Condensed
Molecular
Molecular
Molecular
Materials
Materials
Materials
Laboratory,
Laboratory,
Laboratory,
RIKEN RIKEN
RIKEN
8) E. Bustarret
8)8) E.
E.Bustarret
Bustarret
et al.: Phys.
etetal.:
al.:
Rev.
Phys.
Phys.
Lett.
Rev.
Rev.
93Lett.
Lett.
237005,9393237005,(2004).
237005,(2004).
(2004).
∗3∗3
ResearchResearch
ResearchCenter ofCenter
CenterIntegrative
ofofIntegrative
Integrative
Molecular
Molecular
Molecular
SystemsSystems(CIMoS),
Systems(CIMoS),(CIMoS),
InstituteInstitute
Institutefor Molecularfor
forMolecular
Molecular
Science Science
Science∗4∗4 Research
ResearchResearch
Core forCore
ExtremeCoreforforExtreme
ExtremeQuantum
Quantum
Quantum
World, Okayama
World,
World,Okayama
Okayama
UniUniUniversity versity
versity∗5∗5 Institutea) Thea)a) TheInstitute
Instituteof Physics,
ofofPhysics,
University
Physics,University
Universityof Tsukuba
ofofTsukuba
Tsukuba
experiment
Theexperimentexperiment
was performedwaswasperformed
performed
under the
under
under
ExperimentalthetheExperimental
Experimental
ProProPro∗6∗6 Department
Department
Departmentof Physics,
ofofPhysics,
Tokyo
Physics,
Institute
Tokyo
TokyoInstitute
Instituteof Technology
ofofTechnology
Technology
gram ML1006-LINAC29.
gram
gramML1006-LINAC29.
ML1006-LINAC29.

- 255 -

2. Atomic and Solid State Physics (Muon)

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)µSR study of the magnetism and superconductivity
in the multi-layered Bi-2223 high-Tc superconductor
T. Adachi,∗1,∗2 M. A. Baqiya,∗3 K. M. Suzuki,∗1,∗4 K. Tsutsumi,∗4 M. Fujita,∗1,∗4 S. Adachi,∗5 T. Watanabe,∗5
I. Watanabe,∗1 and Y. Koike∗1,∗3

∗1
∗2
∗3
∗4
∗5

RIKEN Nishina Center
Department of Engineering and Applied Sciences, Sophia
University
Department of Applied Physics, Tohoku University
Institute for Materials Research, Tohoku University
Graduate School of Science and Technology, Hirosaki University- 257 -

is observed at 0.3 K, indicating the development of the
Cu-spin correlation. The λ at 0.3 K is more signiﬁcantthan that observed in the underdoped crystals at 0.3
K. Moreover, the temperature dependence of λ exhibits
local maxima at 40 K and 1 K probably corresponding
to the development of the Cu-spin correlation in IP
and OP’s, respectively. The temperatures are higher
than those observed in the underdoped crystals, respectively. These results suggest that the Cu-spin correlation is more developed in the HUD crystals than in
the underdoped crystals, although no muon-spin precession due to the formation of a magnetic order isobserved even at 0.3 K. Accordingly, the p value of IP
in the HUD Bi-2223 cuprate may reside in the vicinityof the boundary between the AF and superconducting(SC) phases in the phase diagram.
In summary, we have found two distinct developments of the Cu-spin correlations probably originatingfrom IP and OP’s in the HUD Bi-2223 crystals. The
p value of IP probably resides in the vicinity of theboundary between the AF and SC phases in the phase
diagram, suggesting that the Bi-2223 crystals with Tc
lower than ∼ 40 K exhibit an AF ground state.

Raw Asymmetry (%)

In the research of high-Tc cuprate superconductors,
the relationship between the magnetism and superconductivity has been a central issue. Nuclear-magneticresonance (NMR) experiments in the so-called multilayered Hg-based cuprate Hg-1245 with 5 CuO2 planesin the unit cell have revealed that the hole concentration per Cu, p, in the CuO2 plane is larger in the outerplanes (OP’s) than in the inner planes (IP’s) due to thediﬀerence in the coordination number of Cu between
OP’s and IP’s.1) Moreover, it has been suggested thatboth antiferromagnetic (AF) order and superconductivity coexist homogeneously in a CuO2 plane with asmall p value. In the optimally doped Hg-1245 cuprate,
it has been reported from zero-ﬁeld (ZF) µSR measurements that a muon-spin precession is observed at low
temperatures, suggesting the coexistence of AF orderand superconductivity.2)
Fujii et al.
have succeeded in growing sizable single-crystals of a tri-layered Bi-based cuprate
Bi2 Sr2 Ca2 Cu3 O10+δ (Bi-2223) with Tc = 110 K.3) Recently, we have performed ZF-µSR measurements of
the underdoped Bi-2223 single-crystals with Tc = 87
K, obtained through the reduction annealing. It has
been found that the depolarization rate of muon spins,
λ, increases with decreasing temperature and exhibits
a local maximum at 10 K, followed by an increase below 5 K. This suggests the existence of two distinct
Cu-spin correlations in a crystal probably originatingfrom IP and OP’s. However, the development of the
Cu-spin correlation is weak even at 0.3 K, preventing
us from investigating the detailed magnetic state in
Bi-2223 cuprates. Based on the results, we have performed µSR measurements of Bi-2223 in the heavily
underdoped (HUD) regime with Tc = 40 − 60 K, obtained through the further reduction-annealing. The
ZF and longitudinal-ﬁeld µSR measurements were carried out using a ﬂy-past HELIOX cryostat at temperatures down to 0.3 K at RIKEN-RAL.
Figure 1 shows ZF spectra of the HUD Bi-2223. At
250 K, the spectrum shows a slow depolarization ofmuon spins, indicating that Cu spins ﬂuctuate fast beyond the µSR frequency range. With decreasing temperature, it is found that the depolarization becomes
fast gradually and an exponential-like depolarization

20

Bi2Sr2Ca Cu O10+δδ

15

Heavily underdoped(Tc = 40 - 60 K)
Zero field

2

3

10
T = 250 K
40 K
2K
20 K
1K
5 K 0.3 K

5
0

2

4

6

8

10

12

Time (µµsec)
Fig. 1. Zero-field µSR time spectra of the heavily underdoped Bi2 Sr2 Ca2 Cu3 O10+δ single crystals with Tc =40 − 60 K.

References
1) H. Mukuda et al.: J. Phys. Soc. Jpn. 77, 124706(2008).
2) K. Tokiwa et al.: Physica C 460-462, 892 (2007).
3) T. Fujii et al.: J. Cryst. Growth 223, 175 (2001).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)µSR study of the Al-induced magnetic order in La2−x
2−xSrxxCu1−y1−yAlyyO44
∗1,∗2
∗1,∗3
∗4
∗1
∗1
∗1
K.
K. M.
M. Suzuki,
Suzuki,∗1,∗2
T.
T. Adachi,
Adachi,∗1,∗3
M.
M. A.
A. Baqiya,
Baqiya,∗4
M.
M. Abdel-Jawad,
Abdel-Jawad,∗1
S.
S. Yoon,Yoon,∗1I.
I. Watanabe,
Watanabe,∗1
and
and
∗1,∗4
∗1,∗4
Y.
Y. Koike
Koike

The
The so-calledso-called stripe
stripe correlation
correlation ofof spins
spins andand holes
holes
has
has been
been studiedstudied intensively
intensively inin orderorder toto clarify
clarify its
its rerelationshiplationship with
with thethe appearance
appearance ofof superconductivity
superconductivity
inin thethe high-T
high-Tcc cuprates.
cuprates. Nevertheless,
Nevertheless, thethe details
details ofofthethe stripes
stripes have
have notnot yetyet been
been clariﬁed
clariﬁed toto date.
date. OneOneofof thethe reasonsreasons isis thatthat thethe frequencies
frequencies ofof thethe dynamdynamical
ical stripes
stripes areare fasterfaster than
than thethe µSRµSR frequency
frequency range
range
in
in aa wide
wide range
range ofof thethe hole-concentration
hole-concentration per
per Cu,Cu, p,
p,
where
where thethe superconductivity
superconductivity appears.
appears. For
For this
this reareason,
son, impurity
impurity substitution
substitution isis oneone ofof crucial
crucial ways
ways toto
study
study thethe stripe
stripe correlation,correlation, because
because substituted
substituted imimpurities
purities tend
tend toto slow
slow down
down thethe spin
spin ﬂuctuations,ﬂuctuations, leadleading
ing toto thethe formation
formation ofof thethe static
static stripe
stripe order.
order. ForFormerly,
merly, we
we havehave found
found fromfrom thethe zero-ﬁeld
zero-ﬁeld (ZF)
(ZF) µSR
µSR
3+
that
that thethe magnetic
magnetic impurity
impurity Fe
Fe3+
tends
tends toto stabilize
stabilize aa
magnetic
magnetic order
order inin thethe whole
whole superconducting
superconducting regime
regime of
of
1,2)
1,2)
La
La2−x
Sr
Sr
Cu
Cu
Fe
Fe
O
O
(LSCFO).
(LSCFO).
Intriguing
Intriguing
is
is
that
that
2−x xx1−y
1−y yy 44
doubledouble successive
successive magnetic
magnetic transitionstransitions areare observed
observed ininthethe overdoped
overdoped regime
regime ofof LSCFO,LSCFO, indicating
indicating thatthat thethestripestripe order
order induced
induced byby thethe FeFe substitution
substitution persists
persists up
up
toto pp ∼
∼ 0.300.30 andand terminatesterminates there.
there. As
As forfor eﬀects
eﬀects ofof nonnon2+
magnetic
magnetic Zn
Zn2+
substitution,
substitution, weakness
weakness ofof thethe develpdevelpment
ment ofof thethe Cu-spin
Cu-spin correlation
correlation by
by thethe ZnZn substitution
substitution
prevents
prevents us
us fromfrom understanding
understanding thethe nature
nature ofof thethe CuCu3)
spin
spin correlation
correlation especially
especially inin thethe overdoped
overdoped regime.
regime.3)
Recently,
Recently, we
we havehave observed
observed unexpected
unexpected behavior
behavior inin
3+
non-magnetic
non-magnetic Al
Al3+-substituted-substituted La
La2−x
Sr
Sr
Cu
Cu
Al
Al
O
O
2−x xx1−y
1−y yy 44(LSCAO)(LSCAO) by
by thethe µSRµSR measurements,
measurements, namely,
namely, aa static
staticmagnetic
magnetic state
state isis induced
induced byby 3%
3% Al-substitution
Al-substitution inin thetheoverdoped
overdoped regime.
regime. It
It is
is expected
expected thatthat eﬀects
eﬀects ofof nonnonmagnetic
magnetic impurities
impurities onon thethe Cu-spin
Cu-spin correlation
correlation will
will bebeclariﬁed
clariﬁed even
even inin thethe overdoped
overdoped regime.
regime.
Therefore,
Therefore, inin orderorder toto investigate
investigate thethe magnetism
magnetism ininduced
duced byby thethe AlAl substitution,
substitution, we
we havehave performed
performed ZFZFµSRµSR experiments
experiments forfor LSCAOLSCAO with
with xx == 0.11
0.11 –– 0.30
0.30 andandyy == 0.03.
0.03. The
The polycrystalline
polycrystalline samples
samples were
were preparedpreparedbyby thethe ordinary
ordinary solid-statesolid-state reaction
reaction method.
method. ZF-µSR
ZF-µSR
measurements
measurements were
were carried
carried out
out usingusing aa Variox,
Variox, aa HeHeliox
liox andand aa Janis
Janis cryostats
cryostats at
at temperaturestemperatures down
down toto 0.30.3
K
K at
at RIKEN-RAL.
RIKEN-RAL.
FigureFigure 1(a)1(a) shows
shows thethe ZF-µSR
ZF-µSR time
time spectra
spectra ofof
LSCAO
LSCAO with
with xx == 0.300.30 andand yy == 0.03.
0.03. AtAt 5.05.0 K,
K, thethespectral
spectral shows
shows thethe Gaussian-type
Gaussian-type relaxation
relaxation due
due toto thetherandomly-oriented
randomly-oriented nuclear
nuclear dipole
dipole ﬁeld,
ﬁeld, indicating
indicating elecelectrontron spins
spins ﬂuctuate
ﬂuctuate fast
fast beyond
beyond thethe µSRµSR timetime window.
window.
With
With decreasing
decreasing temperature,temperature, thethe muon-spinmuon-spin depolardepolarization
ization becomes
becomes fast
fast progressively
progressively down
down toto 0.8
0.8 K
K and
and

ﬁnallyﬁnally aa nearly-staticnearly-static magnetic
magnetic order
order isis formed
formed at
at 0.30.3
K,K, suggestingsuggesting aa remarkableremarkable eﬀect
eﬀect ofof thethe Al-substitution
Al-substitutiononon thethe development
development ofof thethe Cu-spin
Cu-spin correlation
correlation even
even ininthethe heavily-doped
heavily-doped regime.
regime. Figure
Figure 1(b)1(b) shows
shows thethe pp dedependence
pendence ofof thethe magnetic
magnetic transitiontransition temperature,temperature, TTNN,,
deﬁneddeﬁned asas thethe midpoint
midpoint ofof thethe changechange inin thethe initial
initialasymmetryasymmetry ofof thethe magnetic
magnetic component
component inin an
an analyticalanalytical
function.
function. It
It is
is foundfound thatthat TTNN decreases
decreases monotoniously
monotoniously
withwith increasing
increasing p,
p, suggestingsuggesting thatthat thethe stripe
stripe order
order isisinducedinduced also
also inin thethe overdoped
overdoped regime.
regime. Moreover,Moreover, TTNN
2)
disappears
disappears at
at pp ∼
∼ 0.300.30 asas observed
observed inin LSCFOLSCFO2)
and
and
3)
3)
LSCZO.
LSCZO. Therefore,
Therefore, it
it hashas been
been concluded
concluded that,
that, reregardlessgardless ofof thethe type
type ofof impurities,
impurities, thethe development
developmentofof thethe stripe
stripe correlation
correlation isis observed
observed up
up toto pp ∼
∼ 0.30,0.30,
suggestingsuggesting an
an intimate
intimate relationshiprelationship between
between thethe stripe
stripecorrelation
correlation andand thethe appearance
appearance ofof thethe high-T
high-Tcc supersuperconductivity.
conductivity. Considering
Considering thethe diﬀerence
diﬀerence between
between the
the
3+
2+
3+
results
results of
of Fe
Fe3+
,, Zn
Zn2+
and
and AlAl3+,, charge
charge disorderdisorder as
as wellwell
as
as large
large magnetic
magnetic moments
moments may
may play
play anan important
important rolerole
inin thethe stabilization
stabilization ofof thethe stripe
stripe correlation.
correlation.

∗1∗1

References
References

∗2
∗2
∗3
∗3

∗4
∗4

RIKEN
RIKEN Nishina
Nishina Center
CenterInstitute
Institute forfor Materials
Materials Research,
Research, Tohoku
Tohoku University
University
Department
Department ofof Engineering
Engineering andand Applied
Applied Sciences,
Sciences, Sophia
SophiaUniversity
University
Department
Department ofof Applied
Applied Physics,
Physics, Tohoku
Tohoku University
University

La
La2-x
SrxxCu
Cu1-y
AlyyO
O44
2-xSr
1-yAl
xx == 0.30,
0.30, yy == 0.03
0.03

Normalized Asymmetry

1.0
1.0
0.8
0.8

5.0
5.0 K
K
3.0 K
K
3.0
1.5 K
K
1.5
1.2 K
K
1.2
0.8 K
K
0.8
0.3 K
K
0.3

0.6
0.6
0.4
0.4
0.2
0.2
00

00

22

88

66

88

10
10

La
La2-x
SrxxCu
Cu1-y
AlyyO
O44
2-xSr
1-yAl
yy == 0.03
0.03

77
66

TN (K)N

44

Time
Time (µ(µµµsec)
sec)

55
44
33
22
11
00

00

0.05
0.05

0.10
0.10

0.15
0.15

pp (( == xx -- y)
y)

0.20
0.20

0.25
0.25

0.30
0.30

Fig.
Fig. 1.
1. (a)(a) Zero-field
Zero-field µSRµSR timetime spectra
spectra of
of La
La2−x
SrxxCu
Cu1−y
AlyyO
O44
2−xSr
1−yAl
(LSCAO)(LSCAO) with
with xx == 0.300.30 andand yy == 0.03.
0.03. (b)(b) Temperature
Temperaturedependence
dependence ofof thethe magnetic
magnetic transitiontransition temperature,temperature, TTNN,,
ofof LSCAOLSCAO with
with yy == 0.03.
0.03.

1)
1) K.
K. M.
M. Suzuki
Suzuki etet al.,
al., Phys.
Phys. Rev.
Rev. BB 86,
86, 014522
014522 (2012).
(2012).
2)
2) K.
K. M.
M. Suzuki
Suzuki etet al.,
al., inin preparation.
preparation.
3)3) Risdiana,
Risdiana, etet al.,
al., Phys.
Phys. Rev.
Rev. BB 77,
77, 054516
054516 (2008).
(2008).

- 258 -

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)µSR study of cluster-glass state in Sr1−x Lax RuO3
I. Kawasaki,∗1,∗2 M. Yokoyama,∗3 K. Fujimura,∗3 and I. Watanabe∗2

1.0

Normalized Asymmetry

50 K

Sr0.6La0.4RuO3

0.8

24 K

0.6

12 K

0.4
0.2
0

0

2

4

6

8

∗3

0.6
0.4
0.2
0

0

5

10

15

20

25

30

T (K)

Fig. 2. Temperature dependence of the volume fraction.

In the present study, we performed µSR experimentson polycrystalline sample of Sr1−x Lax RuO3 to further
investigate the cluster-glass state of this system. TheµSR experiments were carried out at the RIKEN RAL
Muon Facility in the UK, where an intense pulsed
muon beam is available.
Figure 1 shows the zero-ﬁeld spectra for x = 0.4 measured at various temperatures. Below 30 K, the relaxation rate develops and a loss of initial asymmetry isobserved, indicating a development of magnetic clusters. The ZF-spectra are well ﬁtted by the following
function, which assumes a presence of two components:
1
2
P (t) = A1 [ e−λ1 t + (1 − ∆1 t)e−∆1 t ]3
3
1 −λ2 t 2
+ (1 − ∆2 t)e−∆2 t ],+A2 [ e33where A1 and A2 represent the paramagnetic and ordered volume fractions respectively. The temperaturedependence of the volume fraction of the magnetic ordered region is shown in Fig. 2. The volume fraction
exhibits a rapid increase at around 10 K, where themagnetic susceptibility shows a peak,6) and reaches
nearly 100% at the lowest temperature. The presenceof the magnetic ground state with the volume fractionof 100% inevitably indicates the itinerant nature of theRu 4d electrons in this system.
1) S. A. Grigera et al.: Science 294, 329 (2001).
2) Y. Maeno et al.: Nature 372, 532 (1994).
3) A. Callaghan et al.: Inorg. Chem. 5, 1572 (1966).
4) J. Okamoto et al.: Phys. Rev. B 60, 2281 (1999).
5) P. B. Allen et al.: Phys. Rev. B 53, 4393 (1996).
6) I. Kawasaki et al.: J. Phys. Soc. Jpn. 83, 064712(2014).]
7) H. Nakatsugawa et al.: J. Phys.: Condens. Matter 14,
415 (2002).

10

Fig. 1. Zero-field µSR spectra.
∗2

Sr0.6La0.4RuO3

0.8

References
6K
Time (µs)

∗1

1.0

Vf

Strontium ruthenate shows various types of physicalproperties attributed to the itinerant feature of Ru 4delectrons and the strong mixing between Ru 4d andO 2p electrons.1,2) SrRuO3 crystallizes into a distorted
perovskite structure and is a ferromagnet with a Curie
temperature of about 160 K.3) Photoemission experiments showed that the density of states at Fermi levelis dominated by the Ru 4d state.4) Therefore, itinerant Ru 4d electrons are considered to be responsible
for the magnetic properties. It is also argued that thedevelopment of the incoherent component in the density of states reﬂects the electronic correlation eﬀects.
In addition, this system shows “ bad metal ” behavior in transport at high temperatures: the electricalresistivity continues to increase with increasing temperature, even though the Boltzmann mean free path
becomes smaller than the lattice constants, indicating that the itinerant quasi-particle description is nolonger available in the high temperature range.5) Theseexperimental ﬁndings suggest that the physical properties are strongly inﬂuenced by the correlation of theRu 4d electrons, and the Ru 4d states have a dualityof itinerant and localized natures.
We have studied the Sr site-substituted system
Sr1−x Lax RuO3 .6) Substituting La for Sr suppress the
Ferromagnetism.7) In addition, the Ru-O distance increases with increasing x, suggesting that doping La
may enhance the role of the electronic interaction. Recent our studies suggest that for x ≥ 0.3, disorder plays
an important role and this system shows a short range
ferromagnetic ordering (cluster formation), and withfurther decreasing temperature these clusters freeze
into a cluster-glass state.

Graduate School of Material Science, University of Hyogo
RIKEN Nishina Center
Faculty of Science, Ibaraki University- 259 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)

Investigation of magnetic ground states in mixed kagome systems(Rb1−x Csx )2 Cu3 SnF12 by µSR
T. Suzuki,∗1,∗4 K. Katayama,∗2 H. Tanaka,∗2 T. Goto,∗3 and I. Watanabe∗4

∗1
∗2
∗3
∗4

(a)

(c)

LF200G

0.27 KLF-µSR

1
Corrected Asymmetry

Corrected Asymmetry

1
19 K

0.8

5K

0.6

4K

0.4
3K
1K

0.2

0.8
3000 G

0.6
1500 G
1000 G

0.4
200 G

0.2

500 G

0.27 K3

6
t (µs)

9

0
0

12

3

6
t (µs)

9

0.4

0.4

(b)

5

(d)

LF 200 gauss
λ1

0.3

T = 0.27 K
λ1
λ2

0.3

- 260 -λ1 (µs-1)

λ2

College of Engineering, Shibaura Institute of Technology
Department of Physics, Tokyo Institute of Technology
Department of Physics, Sophia University
RIKEN Nishina Center

12

0.2

4

3
0.2
2

λ2 (µs-1)

0
0

λ1

10

0.1

0.1
5
0
0

10
T (K)

0
20

1

λ2

The Heisenberg kagome antiferromagnet (HKAF)
has attracted much attention in magnetism, because
several frustration and quantum eﬀects have been indicated by theories. For example, in√the classicalspin√model case for HKAF, the q = 0 or 3 × 3 magnetic
structure is stabilized when the next-nearest-neighborinteraction is considered. In the case of S = 1/2 kagome lattice, exotic magnetic ground states have beentheoretically predicted. For example, numerical calculations revealed that the ground state is a magnetically disordered spin liquid. In the ground state, triplet
excitations are gapped, and there exists the continuum of low-lying singlet states below the triplet gap1) .
Valence-bond crystal by a periodic arrangement of singlet dimers has also been proposed as the magnetic
ground state of S = 1/2 HKAF2) . Experimentally,
many kinds of HKAF have been investigated as thecandidate for the ideal kagome spin lattice material.
Another new candidate for the ideal kagome latticewith an exotic magnetic ground state was reported
by Ono et al. The cupric compound A2 Cu3 SnF12 (A= Cs, Rb), which is the subject of this study, is a
newly synthesized family of S = 1/2 HKAF3,4) . For
Cs2 Cu3 SnF12 , the weak-ferromagnetic behavior is observed below TN = 20 K, and it is suggested that theantiferromagnetic ordered state appears4) . On the other hand, for Rb2 Cu3 SnF12 , the ﬁrst realization of the”pinwheel” valence bond solid (VBS) ground state in
the S = 1/2 HKAF are conﬁrmed by inelastic neutron measurements5) . Quite recently, mixed kagome
systems (Rb1−x Csx )2 Cu3 SnF12 have been prepared6) .
By magnetic susceptibility and speciﬁc heat measurements on single crystals, they reported a phase diagram, which shows the existence of the quantum phasetransition from the VBS to the AF phase at xc = 0.53.
In this concentration, the spin gap vanishes and theordered state disappears from the view point of magnetization results.
We carried out LF-µSR measurements in x = 0.53
single crystal to investigate dynamical magnetic properties microscopically. Figure 1 (a) shows LF-µSR
time spectra in 200 gauss at various temperatures.
It is emphasized that no disappearance of the initialasymmetry is observed. Below 3 K, time spectra are
well ﬁtted by the two component function as follows:
A(t) = A1 exp(−λ1 t)+A2 exp(−λ2 t). Here, A1 = 0.58,
A2 = 0.42. As shown in Fig. 1 (b), λ1 increases

0 2
10

103
HLF (gauss)

0104

Fig. 1. (a)Temperature dependence of the time spectra in
the LF of 200 gauss. (b) Temperature dependence ofthe muon spin relaxation rate in LF 200 gauss. (c) LFµSR time spectra above 200 gauss up to 3000 gauss at
0.27 K. (d) LF dependence of the muon spin relaxation
rate at 0.27 K.

with decreasing temperature. LF-dependence of time
spectra at 0.27 K is shown in Fig. 1 (c), and LFdependence of relaxation rates is shown in (d). Muon
spin relaxation rates are inversely proportional to LF,
and such change indicates “white” frequency spectra,
which means the spectra are described by summationof continuously distributed frequencies using the Redﬁeld formula. These results suggest that the internal ﬁelds ﬂuctuate, and are consistent with reported
macroscopic results at least down to 0.27 K.
References
1) H. C. Jiang et al.: Phys. Rev. Lett. 101, 117203 (2008).
2) R. R. P. Singh et al.: Phys. Rev. B 77, 144415 (2008).
3) M. Muller et al.: Z. Anorg. Allg. Chem. 621, 993 (1995).
4) T. Ono et al., Phys. Rev. B 79, 174407 (2009).
5) K. Matan et al., Nature Phys. 6, 865 (2010).
6) K. Katayama et al.: arXive:1412.5770v1 [cond-matt.strel].

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)

High pressure µSR study of quantum phase transition in CeNiAsO
H. Guo,∗1,∗2 Y. Luo,∗1 I. Watanabe,∗2 and Z. Xu∗1
The discovery of superconductivity in LaFeAsO1−y Fysystems1) triggers not only a new search of the ironbased superconductors, but also studies of the Kondo
eﬀect when La is replaced by magnetic ions such as Ce.
The Fe 3d electrons in such systems usually undergo aspin-density-wave (SDW) transition at about 140 K on
top of the much lower temperature where the 4f electrons become magnetically ordered.2) In order to study
the 4f electronic properties, we therefore focused on a
Ni-based compound, namely, CeONiAs, instead of Febased compounds since the Ni ions are not long-ranged
magnetically ordered in these compounds, as observedby experiments and theoretical calculations.3)
Our previous studies including magnetic susceptibility, transport, and thermal dynamic measurements
show that CeONiAs undergoes two successive magnetic transitions at T1 = 9.3 K and T2 = 7.3 K, respectively, and these two transitions can be suppressed both byhydrostatic and chemical pressures (P ). When P > 4
kbar, T1 can be hardly seen, while T2 is continuously
suppressed with a critical value of Pc ∼ 6.3 kbar. Resistivity measurements indicate that there is a quantum phase transition at Pc . In order to reveal the roleof magnetic correlations around the quantum criticalpoint (QCP), and the evolution of magnetic structurewith pressure, we have performed µSR experimentswith gas pressures up to 6.1 kbar on CeONiAs0.9 P0.1 ,where the substitution of As by P is expected to reduce
Pc .
During the high pressure µSR measurement, mostof the muons are stopped at the pressure cell madeof Cu, and therefore, muon spin precession is hardly
observed even when magnetic ordering appears in thesample, which limits our analyses of the evolution of
the magnetic structure with pressure from the observation of muon spin precession in the zero ﬁeld (ZF)
measurement. Alternatively, we performed transverse
ﬁeld (TF) measurements and the spectra were ﬁtted
using the following function:
A(t) = Aini cos(γµ Bt + φ)exp(−λt)(1)

where Aint is the initial asymmetry, γµ is the muon
gyromagnetic ratio, B is the magnetic ﬁeld, and λ isthe muon spin relaxation rate.
Figure 1(a) shows the temperature dependence of
the initial asymmetry, Aini at ambient pressure (A.P.)
and P = 6.1 kbar. At A.P., Aini is nearly temperature independent at high temperatures, and decreases
sharply below approximately 10 K. No further significant change is observed below 10 K due to the low∗1∗2

Department of Physics, Zhejiang University
RIKEN Nishina Center- 261 -

Fig. 1. Temperature dependence of the extracted parameters. (a) The initial asymmetry. (b) The muon spin
relaxation rate, λ. The arrows indicate the magnetictransition temperatures.

signal-to-background ratio. The transition temperature is suppressed to approximately 6 K when P = 6.1
kbar. Fig. 1(b) shows the temperature dependence ofthe muon spin relaxation rate λ. The substantial increase of λ below about 10 K and 6 K, respectively, at
A.P. and P = 6.1 kbar is consistent with the resultsof the temperature dependence of Aini . The appearance of the internal ﬁeld will increase the internal ﬁeld
distribution width at the muon site, thus enhancing
the muon spin relaxation rate. Owing to the usageof a pulsed muon source, the increase in muon spin
relaxation rate will usually lead to a decrease in theinitial asymmetry. Thus, our current results conﬁrm
the magnetic ordering from the microscopic view point.
The application of high pressures up to 6.1 kbar also
conﬁrms that the magnetic ordering is suppressed bypressure. Unfortunately, valuable information about
the evolution of the internal ﬁeld with the pressurecannot be obtained since we cannot observe the muon
spin precession directly as mentioned above.
References
1) Y. Kamihara, H. Hiramatsu, M. Hirano, R. Kawamura,
H. Yanagi, T. Kamiya, and H. Hosono, J. Am. Chem.
Soc. 128, 10012 (2006).
2) J. Zhao, Q. Huang, C. de la Cruz, S. Li, J. W. Lynn,
Y. Chen, M. A. Green, G. F. Chen, G. Li, Z. Li, J. L.
Luo, N. L. Wang, and P. Dai, Nature Materials 7, 953(2008).
3) T. M. McQueen, T. Klimczuk, A. J. Williams, Q.
Huang, and R. J. Cava, Phys. Rev. B 79, 172502 (2009).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)

Investigation of hydrogen dynamics in hydroxyl salts Co2(OD)3Cl
X.L. Xu,＊1 X.G. Zheng,＊1 H.J. Guo,＊2 and I. Watanabe＊2
The dynamic Kubo-Toyabe function represents thecontribution from the nuclear dipolar field of D atoms, andthe exponential one accounts for magnetic relaxation.

0.24
172.3 K
209.1 K245.2 K272.7 K

Co (OD) Cl
2

0.2

3

change in dynamics of thenuclear dipolar field of D

0.16

Asymmetry

Hydroxyl salts of the type M2(OH)3X (X = Cl, Br, or I)
have been known for a long time. These compounds
containing magnetic ions are magnetic materials. However,
only in recent years their magnetic properties have beenclarified as a result of our research 1,2) and they are known
as “frustrated magnets”. Our latest finding is universal
strong magnetic--dielectric--lattice coupling in all suchcompounds. Measurements of dielectric constants andlattice parameters revealed simultaneous changes at therespective TN for all hydroxyl salts, which indicate strong
magnetic--dielectric--lattice coupling. Moreover, we foundthat for Co2(OH)3Cl and Co2(OH)3Br, which have thehighest crystal symmetry in the hydroxyl salt series shownin Fig. 1, the corresponding deuterated compounds
Co2(OD)3Cl [Br] clearly exhibited a ferroelectric responseat exceptionally high temperatures. Sharp peaks wereobserved at 229 K in both dielectric constants measured at
100 kHz for Co2(OD)3Cl.3) Similar behaviors were observedin Co2(OD)3Br (TE = 224 K at 100 kHz).

0.12

0.08

0.04

0

0

2

4

Time (s)

6

8

10

Fig. 2. Muon-spin-relaxation spectra indicating a change inthe dynamics of D atoms in Co2(OD)3Cl.

-1

Fluctuation rate of D (s )

0.7
0.65

Co (OD) Cl
2

3

0.6
0.55
0.5
0.45
0.4
0.35
0.3
100

150

200

T

250

300

T (K)

Fig. 1. High crystal symmetry of Co2(OD)3Cl.
Therefore, we performed SR experiments on Co2(OD)3Cl
to reveal the mechanism of this unconventional ferroelectric
response, using the muon facilities at RIEKN-RAL. We
observed a change in the dynamics of D atoms in
Co2(OD)3Cl through the nuclear dipolar field of D (Fig. 2).
The asymmetry a(t) of muon-spin-relaxation can beapproximately expressed by a combination of the
dynamic Kubo-Toyabe function and an exponentialfunction.
＊1＊2

Department of Physics, Saga University
RIKEN Nishina Center

Fig.3. The analyzed fluctuation rate of the nuclear dipolar
field of the D atoms in Co2(OD)3Cl.
The analyzed fluctuation rate of the nuclear dipolar field of
the D atoms in Co2(OD)3Cl shows an abrupt changearound the ferroelectric transition temperature TE = 230 K(Fig. 3), suggesting that the hydrogen (D) dynamics plays acritical role in the ferroelectric response of Co2(OD)3Cl.
References

1) X.G. Zheng et al.: Phys. Rev. B 71, 052409 (2005).
2) X.G. Zheng et al.: Phys. Rev. Lett. 95, 057201 (2005).
3) X.G. Zheng et al.: Phys. Rev. B 87, 174102 (2013).

- 262 -

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)

Partial magnetic order in the quantum spin system NH4CuCl3
T. Goto,＊1 K. Matsui,＊1 T. Suzuki,＊2 H. Guo,＊4 A. Oosawa,＊1 M. Fujisawa,＊3 H. Tanaka,＊3 I. Watanabe＊4
The ground states of boson systems with randomness
have been a puzzle for a long time. In a uniform system
consisting of mobile bosons, the ground state is theBose-Einstein condensed fluid. When the mobility ofparticles is reduced by introducing randomness or
frustration, the system becomes solid-like, that is, the Bose
glass or the Wigner crystal, details of which, however, arestill unknown1). For studying the property of the boson
system, NH4CuCl3 is suitable model compound, where both
the density and mobility of the field-induced magnons canbe tuned by the magnitude of applied field and the state of
non-centrosymmetric NH4 molecules, respectively.
The quantum spin magnet NH4CuCl3 is an S =1/2
three-dimensional dimer system with the crystal structure
isomorphic to TlCuCl3, which is a spin-gapped system andis known for the Bose-Einstein condensation offield-induced magnons. The ground state of NH4CuCl3,
however, is different from that of TlCuCl3, that is, gaplessin zero field, showing a magnetic order at TN = 1.25 K.
When a high magnetic field is applied, two-stepmagnetization plateaus are observed2). The mechanism of
the two-step plateaus attracts much interest, for it is related
to the fundamental property of the field-induced magnons.
One of the models3) proposed so far is the localized
three sublattice dimer model that claims an existence of thethree inequivalent dimers A, B and C with different criticalfields Hc, one of which i.e. HcA is zero. This model
elegantly explains the two-step plateaus: the two plateaus
appear in the field regions where the dimer A and B
saturates, and the net magnetization saturates when all threesaturate.
According to this model, only dimer A
magnetically orders at zero field, indicating the partial
magnetic order.
The elastic neutron scattering experiment4) confirms the
doubling of the unit cell along b, supporting the existence of
three inequivalent dimers in an elongated unit cell.
However, recent high-field NMR observation5) disproves
this model. That is, in the high field of the second plateau
region, the two of the three inequivalent dimers are
saturated and only C is paramagnetic, and hence the NMR
signal corresponding to C is expected to be observed atnearly zero-shift position. However, in the high-field NMR
spectra, a signal corresponding to either A or B is also
observed with that for C. This contradiction gives us agood motivation to propose carrying out the SR
experiment on this compound. If the model is correct, one
expects that only one site possesses a large hyperfine field
while the other three quarter sites are expected to remain in
the paramagnetic state, or that when the interaction among
Department of Physics, Sophia University
Department of Physics, Shibaura institute of Technology＊3
Department of Physics, Tokyo Institute of Technology＊4
RIKEN Nishina Center＊1＊2inequivalent three dimers is appreciable, three different
hyperfine fields will appear at each dimer, similar to thecase of SrCu2(BO3)2.
So far, zero field (ZF) - SR measurements on single
crystals of NH4CuCl3 were carried out at the Riken-RAL
Muon Facility using a pulsed surface-muon beam with amomentum of 27 MeV/c. In the ordered state below TN, aclear muon spin rotation is observed at zero-field. At thelowest temperature 0.31 K, one can see in the
depolarization curve a clear beat with two different
frequencies and also an extremely fast term thatmonotonically decreases with time. This leads us tochoose reasonably the three-component function
GKT(;)·(A1e-1+A2e-2cos2+A3e-3cos3) to fit thedata below TN. Above TN, the depolarization curves
simply consist of one component, that is, the first term in
the above function.
Figure 1 shows the typicaldepolarization curves with the fitted function at various
temperatures. The two hyperfine fields 1/ and 2/
increased monotonically below TN and reached 150 and 90
Oe. The volume fraction of each component for A1, A2
and A3 were 25, 70 and 5 % at 0.3 K.
Although the observed data clearly demonstrate that theordered state consists of three different parts, the fraction ofeach part is not in accord with the model, which declaresthat A1, A2 and A3 should be in the ratio 1:2:1. For further
quantitative comparison of this result with thethree-sublattice model, the detailed knowledge of the muon
stopping site in the unit cell is indispensable. 6)

Fig. 1. Muon spin depolarization curves at various
temperatures below and above TN=1.25 K. Solid curves
arefittedfunctionwiththreecomponents
GKT(;)·(A1e-1+A2e-2cos2+A3e-3cos3).
References

1) K. Kodama, Science 298, 395 (2002).
2) W. Shiramura et al., J. Phys. Soc. Jpn. 67, 1548 (1998).
3) M. Matsumoto, Phys. Rev. B 68, 180403 (2003).
4) Ch. Rüegg et al., Phys. Rev. Lett. 93, 037207 (2004).
5) H. Inoue et al., Phys. Rev. B 79, 174418 (2009).
6) K. Matsui et al. J. Phys.: Conf. Ser. 551 012007 (2014).

- 263 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)

Zn-substitution effects on distorted tetrahedral spin-chain system Cu3Mo2O9†

The Zn-substitution effects on Cu3Mo2O9 were studied.
This compound has a quasi one-dimensional distorted
tetrahedral spin system made of S = 1/2 Cu2+ ions.1) The
multiferroic properties below the Néel temperature TN = 8 K
has been reported based on macroscopic measurements.2)
The substituted Zn ions cut the magnetic chain directly andreduce the magnetic order. We have reported a novel
magnetic ground state based on some macroscopic
measurements for the heavily (5.0%) Zn-substituted sample.
3)
To obtain a microscopic viewpoint of the Zn-substitution
effects on Cu3Mo2O9, we measured muon spinrotation/relaxation spectra in (Cu,Zn)3Mo2O9 with ARGUS
spectrometer at Port 2. We prepared single crystals oflightly (0.5%) and heavily (5.0%) Zn substituted Cu3Mo2O9
through continuous solid-state crystalization.4) The sliced
single crystals are placed in the Variox cryostat with the 3He
sorption refrigerator. We measured the backward-forward
asymmetry spectrum ABF(t) defined as

ABF(t) = [AB(t)  AF(t)]/ [AB(t) + AF(t)]

,

(1)

0.8

(a)

ZF SR, 0.3 K
Zn 5.0% (+0.4)

0.6

0.4

0.2
0

Zn 0.5% (+0.2)
Cu3Mo2O9
0.5
1Time (s)

FFT amplitude (arb. units)

Normalized asymmetry

where AB(t) and AF(t) are the signal from the backward andthe forward counters, respectively. A parameter  ~ 1 isintroduced to correct the small misalignment of the system.
The signals from the muons stopping at the Ag foil on the
crystals are removed using the comparison of ABF(t) under
the transverse magnetic field of 20 G at temperatures below
and above TN. We found that approximately 75% of theimplanted muons are stopped at the crystal.
Internal field (G)0500 1000
0.6 (b)ZF SR, 0.3 K
0.4

0.2

0
0

Zn 5.0% (+0.4)

Zn 0.5% (+0.2)

Cu3Mo2O91020Frequency (MHz)Fig. 1. Normalized asymmetry spectra at 0.3 K in
(Cu,Zn)3Mo2O9 in (a) and their fast Fourier transformationin (b). The upper scale in (b) denotes the internal fieldworking on the muon stopping site(s).

----------------------------------------------------------------------------------------------------------†

Condensed from the article in JPS Conf. Proc. 2, 010206 (2014)
Physics Division, Sophia University＊2
RIKEN Nishina Center＊3
Natuional Institute for Material Science (NIMS)＊1

Order Parameter(normalized)

H. Kuroe,＊1,*2 T. Sekine,＊1 I. Kawasaki,＊2 I. Watanabe,＊2 and M. Hase＊3

1

0.5

0
0

SR (Cu3Mo2O9)
SR (Zn 0.5%)SR (Zn 5.0%)
Magnetization
Hamasaki et al.
Calculation based on
Brillouin function
0.5

1Normalized Temperature

Fig. 2. Normalized internal fields in (Cu,Zn)3Mo2O9, themagnetization taken from ref. 1, and the saturation
magnetization calculated based on the Brillouin function asfunctions of the temperature normalized by TN.
Figures 1(a) and 1(b) show the SR time spectra andtheir fast Fourier transformations, respectively. In pure
Cu3Mo2O9 and the Zn-0.5% sample, the signals are very
similar, indicating the same magnetic ground states. The
oscillation frequencies of the SR time spectra in Fig. 1(a)correspond to the dominating components in thefrequency-domain spectra of Fig. 1(b) due to the muon
precession around the internal field of 650 G. The beat on
the oscillating spectrum at approximately 0.7 s in Fig. 1(a)and the weak peak at 750 G in Fig. 1(b) indicate the twokinds of internal magnetic fields. In the Zn-5.0% sample,
the rapidly decaying oscillation in the time-domain
spectrum and the widely distributed frequency-domain
spectrum were observed as shown in Figs. 1(a) and 1(b),respectively. We conclude that the magnetic ground state of
the Zn-5.0% sample is different from the ones in pure
Cu3Mo2O9 and the Zn-0.5% sample.
In Fig. 2, we show the normalized amplitudes of thedominating internal field in Cu3Mo2O9 and the Zn-0.5%
sample and that of the averaged internal field in theZn-5.0% sample as functions of temperature normalized by
TN. These normalized amplitudes have similar temperaturedependences with the normalized magnetization because of
the weak ferromagnetic component of the spin moment inpure Cu3Mo2O91) as well as the temperature variation of thesaturation magnetization in a ferromagnet calculated basedon the Brillouin function. These facts indicate that the orderparameter of this multiferroic phase transition is thesublattice magnetization.
References

1) T. Hamasaki et al.: Phys. Rev. B 77, 134419 (2008).
2) H. Kuroe et al.: J. Phys. Soc. Jpn. 80, 083705 (2011).
3) H. Kuroe et al.: J. Kor. Phys. Soc. 63, 542 (2013).
4) K. Oka et al.: J. Cryst. Growth 334, 108 (2011).

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Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)

Magnetic ground state of Cu6O8MCl (M = Y, Pb) with a caged structure
K. Kawashima,*1,*2 H. Takeda,*1 S. Yasuda,*1 S. Igarashi,*1 W. Ito,*1 I. Kawasaki,*2 I. Watanabe,*2 and J. Akimitsu*1＊1＊2

Department of Physics and Mathematics, Aoyama Gakuin University.
RIKEN-RAL, Nishina Centerof Cu+, Cu2+, and Cu3+ 2). These conditions encumber theformation of the completely static magnetic ordered state in
Cu6O8PbCl. The observed behavior of ZF-SR spectra andFig. 2 data of Cu6O8PbCl indicate the growth of theshort-range magnetic interaction between S = 1/2 spins
below 20 K. Consequently, the magnetic ground state of
Cu6O8PbCl does not have a static long range magnetic
ordered state such as an antiferromagnetic state in high-Tc
cuprate. There is possibility that the short range interactionof Cu6O8PbCl forms the spin glass state below 20 K likeunder-doping material in high-Tc cuprate. The magnetic
ground state of Cu6O8MCl compound depends on thevalence state of the M site ion.

Corrected Asymmetry

25

(a)

20

15

10

T = 60 K

T = 10 K
15K
20K
30K

0

2

4

100K
200K
300K

6

8

10

12

14 0

2

4

6

8

10

12

25

Corrected Asymmetry

14

Time (s)Time (s)

(b)

20

15

10

T = 60 K

T = 10 K
15 K
20 K
30 K

0

2

4

100 K
200 K
300 K

6

8

10

12

14 0

2

4

6

8

10

12

14

Time (s)Time (s)Fig. 1 ZF-SR time spectra of Cu6O8MCl ((a) M = Y, (b) M= Pb) at various temperatures. Solid lines indicate the fitting
results of eq. (1).

-1

 (s )

a-relaxing

13-1

 (s )

Cu6O8MCl (M=cation) compound has a Cu6O8 cage
which forms a three-dimensional Cu-O network byconnecting their faces in its crystal structure 1). The formal
Cu valence in the Cu6O8 cage is +2.15 for M = Pb4+ and+2.33 for M = Y3+, suggesting the existence of Cu+ (3d10),
Cu2+ (3d9) with S = 1/2 spin, and Cu3+ (3d8) 2). If there ispartial existence of S = 1/2 spins on the Cu site in the Cu6O8
cage, the static magnetic ordered state is expected in thesquare-lattice and the dynamical spin fluctuation in thetriangular-lattice i.e., the magnetic competition state is
expected in the magnetic ground state of Cu6O8MCl. To
elucidate the detailed physical properties of Cu6O8MCl, we
focused on clarifying the magnetic ground states of
Cu6O8PbCl, which is the semiconducting material, andcompared the observed data with the based material of
Cu6O8YCl, which is the metallic compound withparamagnetic behavior.
SR experiments were performed at the RIKEN-RAL
Muon facility at the Rutherford-Appleton Laboratory, UK.
Fig. 1 shows the zero field (ZF) SR spectra of Cu6O8MCl(M=Y, Pb) at various temperatures. With the decrease in thetemperature, the initial asymmetry of Cu6O8PbCl rapidly
decreased below 20 K (Fig. 1(b)). On the other hand, clear
decreasing behavior of the initial asymmetry was notobserved in the ZF-SR spectra of Cu6O8YCl down to 0.3
K, indicating that there is no magnetic ordered state in thissystem (Fig. 1(a)). The ZF-SR spectra in Fig. 1 wereanalyzed using the following function,
P(t) = Aexp(-t)GKT(,t)+AB (1),where A is the initial asymmetry at t = 0,  is relaxation
ratio of the muon spin, and AB is the background signal.
GKT(,t) is the static Kubo-Toyabe function with ahalf-width of  describing the distribution of thenuclear-dipole field at the muon site 3). Results of thebest-fit of eq. 1 are indicated by the solid line in Fig. 1, andthe observed adjusted parameters A, , and  of Cu6O8MCl(M=Y, Pb) as functions of temperature are shown in Fig. 2.
A (a-relaxing) of Cu6O8YCl slightly decreases with thedecrease in the temperature (Fig. 2), whereas  and  of
Cu6O8YCl are almost constant, being temperature
independent. These facts indicate that there is no change ofspin dynamic and long range magnetic ordered state in
Cu6O8YCl, which is a metallic compound withparamagnetic behavior. For Cu6O8PbCl, the temperaturedependence of a-relaxing, , and  change below 20 K,
indicating the change in the magnetic spin state (Fig. 2).
However, clear precession signal is not confirmed in the
ZF-SR spectra below 20 K. The Cu6O8 cage has asquare-lattice and triangular-lattice on its surface, and theCu sites in the Cu6O8 cage are occupied by various valences

12
11
10

M=Y

9
8
0.08
0.06
0.04
0.02
0
0.15
0.14
0.13
0.12
0.11
0.1
0.09
0.08

M = Pb
M=Y
M = Pb

M=Y
M = Pb

0

50

100

150

200

250

300

T (K)

Fig. 2 Temperature dependence of the initial asymmetry A(a-relaxing), relaxation ratio  and  of Cu6O8MCl (M = Y,Pb) defined by the results of fitting for the Fig. 1 data.
References

1) I. Yazawa, R. Sugise, N. Terada, M. Jo, K. Oka, and H. Ihara,
Jpn. J. Appl. Phys. 29 L1693 (1990).
2) G. Zouganel, K. Bushida, I. Yazawa N. Terada, M. Jo, H.
Hayakawa, and H. Ihara, Sol. St. Comm. 80 709 (1991).
3) Y. J. Uemura, T. Yamazaki, D. R. Harshman, M. Senba, and E. J.
Ansaldo, Phys. Rev. B 31 546 (1985).

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)µSR studies on antiferromagnet RRu2 Al10 (R = Sm, Gd)
H. Tanida,∗1,∗3 H. Guo,∗1,∗2 I. Kawasaki,∗1 M. Sera,∗3 T. Nishioka,∗4 M. Matsumura,∗4
I. Watanabe, ∗1 and Z. Xu ∗2

∗1
∗2
∗3
∗4

RIKEN Nishina Center
Department of Physics and State Key Laboratory of Silicon
Materials, Zhejian University
AdSM, Hiroshima University
Graduate school of Integrated Arts and Science, Kochi University- 266 -

25

Raw Asymmetry (%)

The Kondo semiconductor CeT2 Al10 (T = Ru, Os)with an orthorhombic-type structure shows a uniqueantiferromagnetic (AFM) order at T0 ∼ 30 K.1,2) This
compound exhibits numerous unusual electronic properties that can be ascribed to the strong electron correlation between conduction and localized 4f electrons,
namely, the c − f hybridization effect, by which arenormalized quasi-particle state with heavy effective
electron mass is formed in the case of many Ce- or
Yb-based intermetallic compounds. However, in theclass of materials known as the Kondo semiconductors
or insulators, a temperature-dependent energy gap isformed instead. One of the most salient features ofthis system is magnetic anisotropy in the AFM ordered state. Since the magnetic susceptibility showsa large anisotropy of χa χc χb , an AFM orderedmoment (mAF ) is expected to be parallel to the a-axis
in the AFM ordered state. However, mAF c is realized, as was revealed by neutron scattering and 27 Al
NMR/NQR studies.3–5) The AFM structure is not robust and is easily tuned by magnetic field4) , pressure6) ,or chemical doping.7–9) This indicates that magnetic
exchange interactions are not a key parameter for thismagnetic ordering, but there could be an unknown parameter related to the strong c−f hybridization effect,
which must be related to the extraordinary high transition temperature of T0 ∼30 K.
We previously performed µSR experiments on theabove undoped and Rh-doped CeRu2 Al10 . The results have been published elsewhere.9) One of the residual problems is the serious inconsistency in the temperature dependence of internal fields (Hint ) between
two muon sites, that is, one component shows a usual
mean-field behavior, but the other does not. To address this problem, we planned to perform zero-fieldµSR on related antiferromagnets with more localized
4f -electron character, RRu2 Al10 (R = Nd, Sm, andGd). These compounds are worthy of investigation for
their AFM ordered state; for instance, in the sample R= Gd, mAF is suggested to be parallel to the [011] direction, although a simple dipole-field calculation suggests that mAF prefers the a-axis direction.10) In ref.
9, a possible origin of this discrepancy was suggested
to be the zig-zag chain structure of Gd sites along thec-axis direction.
Figure 1 shows the zero-field time spectra of

GdRu 2 Al 10 ZF
double pulse

20
20 K
15 K

15
10
5
0

Background = 11.426

5

10

15

Time (µs)
Fig. 1. Zero-field time spectra of GdRu2 Al10 at T = 20 and
15 K under double-pulse-beam condition.

GdRu2 Al10 at T = 20 K and 15 K; the data wererecorded under double-pulse-beam condition. We
found that the initial asymmetry is reduced when thetemperature is lowered below the AFM transition temperature of TN = 17 K. This is clear evidence for magnetic ordering. Since Hint is expected to be large because of the large magnetic moment of Gd-4f electrons, we should use single-pulse condition with muchgreater time resolution than that of the double-pulse
condition. However, we had to use the double-pulse
condition within our beam time because we could notbreak the extrinsic noise resulting from the kicker operation. Within the present resolution, we could not
identify any muon-spin precession behavior, and thus,from the zero field measurement, we could not obtain
quantitative information on Hint .
References
1) A. M. Strydom: Physica B 404, 2981 (2009).
2) T. Nishioka et al.: J. Phys. Soc. Jpn. 78, 123705 (2009).
3) D. D. Khalyavin et al.: Phys. Rev. B 82, 100405(R)(2010).
4) H. Tanida et al.: Phys. Rev. B 84, 233202 (2011).
5) M. Matsumura et al.: J. Phys. Soc. Jpn. 78 123713(2009).
6) H. Tanida et al.: Phys. Rev. B 88, 045135 (2013).
7) A. Kondo et al.: J. Phys. Soc. Jpn. 82, 054709 (2013).
8) R. Kobayashi et al.: J. Phys. Soc. Jpn. 82, 093702(2013).
9) H. Guo et al.: Phys. Rev. B 88, 115206 (2013).
10) M. Sera et al.: Phys. Rev. B 88, 100404(R) (2013).

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)

Determination of muon sites on metal-organic hybrids of(C6H5CH2CH2NH3)2CuCl4 and (C2H5NH3)2CuCl4†
E. Suprayoga,1,2 A. A. Nugroho,2 A. O. Polyakov,3 T. T. M. Palstra,3 and I. Watanabe1
Hybrid materials consisting of metal and organic
In order to gain an understanding of the magnetic
components have recently attracted considerable attention
properties of EA and PEA, we are now attempting to reveal
because they have lots of possibilities for tailoring their
the muon positions. We determine the spin alignment byfunctionalities and physical properties by adjusting theircomparing the experimental results with the muon positions
metal and/or organic building blocks [1]. The organic
estimated using the computational techniques on the basis
component can be used not only to bind the metalof the assumption that internal fields at the muon site arecomponents but also to control the connectivity between thecaused by dipole fields from surrounding magnetic
metal components and to manipulate their dimensionality
moments. We present the results of the first trial to apply[2]. One of the interesting type of hybrid materials is thedensity functional theory (DFT) method [4] to EA and PEA
magnetic hybrid with perovskite-type transition metal salt
in order to reveal the minimum energy positions that could
with a chemical formula such as (C2H5NH3)2CuCl4 (EA)
facilitate muon injection. The estimation of the potentialand (C6H5CH2CH2NH3)2 CuCl4 (PEA) [3]. We have carried
minimum positions was carried within the DFT frameworkout µSR measurements on both materials at the RIKENas implemented in the Vienna ab-initio simulation package
RAL muon facilities. The results revealed the appearance of(VASP) [5] using the RICC supercomputer.
clear muon spin precession under the zero-field condition inmagnetically ordered states. This observation provided
evidence of the formation of long-range magnetic orderingof Cu spins. The internal field at the muon site wasdetermined from the muon-spin precession frequency to beapproximately 200 G at 4 K in both systems. In the case of
PEA, a fast-depolarized component in an earlier time region
was observed from room temperature down to 4 K. This
fast depolarized component was not decoupled even infields of a couple of Tesla, showing the existence of a
possible muon state that is strongly coupled with thesurrounding electrons via radical formation. Such a state
(a)
(b)
(c)
(d)
Fig. 2. Crystal
structure (left) and DFT calculation
results
was not observed in EA. The dipole-dipole interaction is too(a)(b)(d)(d)(a)(b)Calculation results of the(c)(c)
Figure 3. (a)potential energy on (C6 H5 CH
2 CH2 NH3 )2 CuCl4 (PEA).
on(b)(c)PEA.
Thepicturesisosurfaces
the electrostatic potentials forweak to trigger the 3D magnetic ordered state because of
Expandedof the CuClof
6 octahedra with estimated minimum potential positions
Figure3.
3. (a)(a)Calculation
Calculation
resultsofthepotential
energyon
CuCl4 (PEA).
6H
5 CH
2 NH
3 )2
Figureofthepotential
energyon(C(C(PEA).
whichresults
are drawn
by isofurfaces.
(d)Expanded
pictureof2 CH
organic
components
aroundthe phenyl
6H
5 CH
2 CH
2 NH
3 )2 CuCl
4
the large distance between the CuCl6 layers.
425
meV(center)
and
1.025
meV
(right)show
possible(b)(c)Expanded
Expanded pictures
picturesofTwo
thepotential
CuCl
with
minimum
potential
positionsring.ofminimum
positionsin and on thephenyl ringare drawn
by isosfurfaces as(b)(c)
theCuCl66 octahedra
octahedra
withestimatedestimated
minimum
potential
positionswell. Isosurfacesin (b), (c) pictureand(d) showpotential
energy areasaround
which
are
195,
425 and 1,025
whicharearedrawn
drawn byby isofurfaces.
isofurfaces.
(d)ofoforganic
components
thethephenylmuon
sites.
which(d) Expanded
Expanded
pictureorganic
components
aroundphenylmeV higher
than that ofandthe minimum
potential position,
respectively.
ring. Two
Twopotential
potential minimum
minimum
positionsisosfurfaces
as as
ring.
positions inin and ononthethephenyl
phenylring
ringarearedrawn
drawnbyby
isosfurfaces
well. Isosurfaces
Isosurfaces inin (b),(b), (c)(c) andand (d)
and
1,025
well.
(d) showshow potential
potentialenergy
energyareas
areaswhich
whichareare195,
195,425
425
and
1,025
foundof potential
six positions.
potential
minimumaroundmeV higher than that toofWetherelaxation
minimum
position,themuon
Morerespectively.
calculatione↵orts positions
are being undertaken
to estimate
meV
higher than that oftheminimum
potential
position,
respectively.
final muon
positions in EA and PEA taking into account those local relaxation e↵ects.
CuCl
6 in EA as well as in PEA, as shown in Figs. 1 and 2.

On the other hand, C1 and C2 which are estimated in PEA around the- phenyl ring can giveto the relaxation of Fourmuon
positions.
Morecalculatione↵ortsare wellbeing
undertaken
to ions
estimateandof muonthemstates(A1- others.
4) werearoundtheapicaldi↵erent
from
As
has
been
discussed,
the Clinjectedmuon
prefers toto the relaxation of muon
positions.
Morecalculatione↵ortsare being
undertaken
to estimate- over the ringradicalstate
aroundtheaccountphenyl ringon which⇡ electrons aredelocalized
final muon positions inform
EAaandPEA
takinginto
those
local relaxatione↵ects.
ions
two
of
them
(B1
and
2)
were
in
betweenin-planeCl
finalOnmuon
positions
in
EA
and
PEA
takingintoaccount
those
local
relaxatione↵ects.
Such C2
a radical
make a large
internal
field atmuon sitethegive
Fermi contact
the other hand,[14].
C1 andwhichstate
are canestimatedin PEAaroundthethephenyl
ringviacan
On the muonother states
hand,
C1
and
C2Thus,which
areestimatedin PEAaroundthecanphenylring
canhyperfine
give fieldthehasmuon
state
identified
in positions
ourµSRinjected
experiment
withcandidatesa largeplane.
These
muon
be
oninteraction.
theCuCl
di↵erentfromothers.
been
well
discussed,themuon
prefersto4As[8], must
be the one
a wellradicaldiscussed,
state aroundthe
phenyl ring.
However,the estimationdi↵erent
muon state
statesaroundfromothers.
As thathasforms
beeninjectedmuon
preferstoform a radical
thephenyl
ring
on
which
⇡ electrons
arethedelocalized
over
the
ring
to
show
muon-spin
precession
behaviorunder
thezero-field
of
the
final
muon
state
aroundthephenyl
ring
is
not
so
easy
and
straightforward.
form
radicalstate statearoundphenylring on which⇡atelectrons
areovercontact
the ring This is[14]. aSuch
a radical
canthemakea largefieldabout
thesitedelocalized
via theFermi
because,the phenyl
ringinternal
has at least
10 muoncrystallographic
orientations
which are ortho-,[14].
Such a radical
state
canstatemakea magneticallylarge internal
fieldorderedat the muon
site
via
Fermi
conditioninstatesinoftheboth
EAcontactandinteraction.
Thus, themuon
identified
in ourexperimenta large
hyperfinefield
metaand parapositions
andtheirµSR
inequivalences
on withboth sides
thering. This
complicatedinteraction.
the
muon
state
identified
inaroundourandµSRexperiment
witha large
hyperfinefield[8], must beThus,
the onethatforms
a radicalstate
thephenyl ⇡ring.
However,theestimation
local
structureofthe phenyl
ring
delocalized
electrons
over
the
ring
make
the
estimation
PEA.
Two
more
minimum
potential
positions
(C1
and
2)
[8],
must
be
the
one
that
forms
a
radicalstate
aroundthephenylring.
However,theestimationdiﬃcult.
Local
e↵ectsin the more accurateofof the final muon statearoundtherelaxation
phenyl ringis arenotalsoso veryeasyimportantand straightforward.
This estimation
is
were
found
in
PEA
in
and
on
the
phenylringoftheorganic
muon
positionsaroundthethephenylring
inPEA.
ofbecause,the finalstate
the phenyl
ring
is not so easyorientations
and straightforward.
This isthemuonphenylringaroundhas at least
about 10
crystallographic
which are ortho-,
because,theparapositions
phenyl part,ring andhascausing
at
least
about
10 crystallographic
which
are ortho-,meta- andtheir
inequivalenceson bothsides statesoforientations
the ring.
This
complicatedpossible
muon
bound
with
the
4. Conclusions
metaand parapositions
andring
theirandinequivalences
both sidesof thecomplicatedlocal structureof the phenyldelocalized ⇡ onelectrons
over theringring.
makeThisthe estimation(b) of EA is shown (c)with Cu ionsFig.(a) 1. Crystal structure
surrounding
electrons
formation
with
large
We applied the density
functional via
theory radical
analysis to estimate
the electrostatic
potential
energylocal
structure
the phenyle↵ects
ring and⇡ electrons
overmore
the ring
makeestimation
the estimationdiﬃcult.
Localofrelaxation
are delocalizedalso very importantin theaccurateofin metal-organic hybrids of (C2 H5 NH3 )2 CuCl4 (EA) and (C6 H5 CH2 CH2 NH3 )2 CuCl4 (PEA) in
Figure 2.represented(a)Calculation results
the potential
usingionsthe density
theoryby ofblue
ballsenergy
andby Clby functional
greendiﬃcult.
balls.positions
Thehyperfine
fields.
Local relaxatione↵ects
are
also
very
important
in
the
more
accurate
estimationofmuon
aroundthethephenylringinPEA.
order to estimate local minimum potential positions as preferences for injected muons to beon (C2 H5 NH3 )2 CuCl4 (EA). (b)(c)Expanded picture of the CuCl6 octahedra with estimatedmuon
positions aroundinitiallythe thetrapped.
phenyl We
ringin PEA.
found
six potential minimum positions around the CuCl6 in EA. The
ofwhichthe areelectrostatic
potential
455
meV
minimumisosurface
potential positions
drawn by isosurfaces.
Isosurfacesforin (b)and (c)show (right)
similar positions were found in PEA as well. Four of them were around the apical Cl atom
4. Conclusions
the potential energy areas which are 337 and 455 meV higher than from the minimum potential
represents
thelocalization
volume
for
muon
site
positions.
References
and
two
of
them
were
in
between
Cl atoms
on the CuCl2 potential
plane. Thosemuon positions
position A1, respectively.
applied the density functional theory analysis toin-plane
estimatethe electrostatic
energy4.WeConclusions_the density
in metal-organic
hybrids
ofN.
(CR.
NH
and
(C6 H5Matter
CH2electrostatic
CH220,
NH315980)2 CuCl
(PEA)
in
1)
C.
al.:
Phys.
Cond.
2 H5Rao3 )et
2 CuCl4J.(EA)
4(2008).
We
appliedfunctional
theoryanalysistoestimatethepotential
energy†order
estimate
local minimum
potential
positionsas preferencesmuons
to be inarticlein Journal
Physics:
Conference
Seriespositions were Condensed
named as A1 tofrom
A4 andthe
B1 to
B2 following
the sameof
definitionin thecaseinof
EA tometal-organic
hybridsofR.
(CKagan)2 CuCl(C945
CH2injectedNH3 )2 CuCl
2 H5 NH
3et
4 (EA) and6 H5 CH
2 for
4 (PEA)
2)C.
al.:Science286,(1999).
as indicated in Fig. 3(b) and (c).
initially
trapped. local
We foundsix potential
around forthe injected
CuCl6 inmuons
EA. Theorder
to estimate
minimum
potentialminimum
positionspositionsas preferences
to be551, 012054 (2014)
In addition to those six potential minimum positions, two more positions appeared insimilarand3) foundA.
O. inPolyakovet minimum
al: Four
Chem.
Materwere24,
133 the(2012).
positionsfound
PEA
as well.
ofpositions
themaroundtheCuCl
apicalCl atom1
initially
trapped. wereWe
six
potential
around6 in EA. The
Nishina
Centeron the phenyl RIKEN
ring of PEA.
Those two
positions are shown in Fig. 3(d) named as C1 and
C2.
and
two
of
them
were
in
betweenin-plane
Cl
atoms
on
the
CuCl
plane.
Those
muon
positions
2 A 140,
similarin PEA
FourPhys.
of themwerearoundthe(1965).
apical Cl atom
2
The C1 positionis almost on the C-H bond of the phenyl ring. The C2 position is within
the positions were4) found
W. Kohn
and asL. well.
J. Sham:
Rev.
1133
FMIPA,
Institut Teknologi Bandungphenyl ring. Potential energies at C1 and C2 sites were about 0.5 eV higher than others
andtwo of them were in between in-plane Cl atoms on the CuCl2 plane. Those muon positions
and
3

Solid
State Chemistry,
Rijkuniversiteit
Groningen!
the di↵erence inthe potential
energy between
the two position was
about 0.1 eV.
Comparing results achieved in EA and PEA, it was found that positions from A1 to A3, B1
and B2 are quite similar in those systems. This fact means that the electrostatic potential aroundthe CuCl6 octahedra is similar in both of EA and PEA. It can be supposed that muon positions
around CuCl6 octahedra are similar and that surrounding organic parts do not a↵ect muon
positions around CuCl6 octahedra. Since di↵erences in the potential energy among estimatedpositions are not so big and was about a hundred of meV, all positions around CuCl6 octahedra
can be preferences for injected muons to be initially trapped. Those positions are expected tocorrespond to those which show the muon-spin precession in the zero-field condition as observedin our previous µSR experiment [8]. It should be noted that the final muon positions must bedi↵erent from those estimated in the current study. We have not yet taken into account local
relaxation e↵ects of lattice which are caused by injected muons. We also did not include thee↵ect of the zero-point vibration motion of the muon itself. Those e↵ects relax initial muon
positions and lead to the deformation of the crystal structure minimizing the total energy and5) G. Kresse and J. Furthmuller: Phys. Rev. 54, 11169 (1996).

- 267 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)

Investigation of muon sites in YBa2Cu3O6 using density functional
theory†S.S. Mohd-Tajudin,＊1,＊2 S.N.A. Ahmad,＊1 D.F. Hasan-Baseri,＊1 E. Suprayoga,＊2,＊3 N. Adam,＊1,＊2 A.F. Rozlan,＊1
S. Sulaiman,＊1 M.I. Mohamed-Ibrahim,＊1 and I. Watanabe＊2
injected muons. Three are close to the apical oxygen of the
CuO5 tetrahedra (marked as M1-M3) and one is close to theplanar oxygen (marked as M4). 2,6) The M5 site is close to
the Cu(I) site in the Cu-O chain, while the M6 site is
between the CuO2 planes. M5 and M6 are new and different
from view point of the well-known argument on the muonbinding state with oxygen because muons prefer to associatewith oxygen to form the hydrogen binding state that lowers
its potential energy.5) According to the following procedure,
we estimate the final state of the muon. We put µ+ on theminimum potential position and recalculate the µ+ positionin the 3x3x3 supercell taking into account the relaxations of
the muon and all atomic positions so as to minimize thetotal energy of the supercell.

Since the discovery of the Cu-based high-Tc
superconducting oxides, both theoretical and experimental
investigations have been carried out to understand theirmagnetism, electronic properties, and superconducting
mechanism.
Butthemechanismofhigh-Tc
superconductivity is still unclear and further investigations
are required. The Muon Spin Relaxation (µSR) technique is
one of the effective approaches for these investigations. TheµSR technique can give us valuable information on high-Tc
superconductivity, electronic states, spin structures, andhyperfine fields. Additional information on muon sites canalso give us more options to quantitatively discuss theseproperties. Unfortunately, successful determination of muonsites from µSR experimental data has been possible only forfew cases in the past. Thus, we have been trying to establish
a way to estimate muon sites from a computational view
point by using the density functional theory (DFT). We havealready tested our method on La2CuO4 (LCO) because thissystem has been well investigated by µSR. There are a lot ofexperimental data related to the antiferromagneticallyordered state in LCO and we can compare the data with our
calculation results to successfully obtain new results interms of muon sites in LCO.1) The similar
anitiferromagneticlally ordered state has also been reported
in YBa2Cu3O6+x (YBCO) and we can apply our
computational method to the YBa2Cu3O6 as well as the caseof LCO.2-4)
The hole concentration of YBCO can be controlled bychanging the oxygen content, x, from 0 to 1. The systemchanges from antiferromagnetic state (x = 0) to
superconducting state (x = 1). 2-4) The anti-ferromagnetictransition temperature, TN, is approximately 350 K at x = 0.
Several components of muon–spin precession have beenclearly observed below TN. This indicates that there aresome muon sites in YBCO.6) In order to optimize theexchange correlation function, we first calculated thedensity of the state of each electronic orbital of YBa2Cu3O6.
After optimizing the electronic correlation function, we
calculated the electrostatic potential as implemented in
Vienna Ab-initio Simulation Package (VASP) by using
RIKEN Integrated Cluster of Clusters (RICC) and found six
local minimum potential positions. These minimum potential
positions can be regarded as initial stopping positions of the

Figure 1. Crystal structure of YBCO with x = 0. Cu(II) in
the CuO2 plane is surrounded by five oxygen atoms and hasa spin half. The Cu(II) rules the antiferromagneticallyordered state, while the Cu(I) which is in the Cu-O chain is
non-magnetic with a zero spin. We found six local
minimum potential positions (M1 to M6) from thecalculation by the DFT method. The positions were drawn
by the isosurfaces in different colors.
We will carry out precise µSR measurement on YBCO
with x = 0 to verify our method for the estimation of muonsites. Then, we will compare the electronic structures,
hyperfine fields, and spin structures with the experimental
results in terms of insulating YBCO.
References

1) B. Adiperdana et al., Phys. Procedia 30 109-112 (2012).
2) N. Nishida et al., Jpn. J. appl. Phys. 26 L1856 (1987).
3) S. Sanna et al., Phys. Rev. Lett. 93 207001 (2004).
4) M. Akoshima et al., Phys. Rev. B 62 6761 (2000).
5) S.S. Mohd-Tajudin et al., Phys. J.: Conf Ser 551 012054 (2014).
6) M. Pinkpank et al., Physica C 317-318 299 (1999).

†

Condensed from the article in Physics Procedia 30 109-112 (2012)
School of Distance Education, Universiti Sains Malaysia＊2
RIKEN Nishina Center＊3
Physics Department, Institut Teknologi Bandung＊1- 268 -

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)

Muon sites in Ce(Ru, Rh)2Al10 investigated using Density Functional Theory
from the perspective of electronic potential†
N. Adam,＊1,＊2 E. Suprayoga,＊1,＊3 B. Adiperdana,＊4 H. Guo,＊5 H. Tanida,＊6 S.S Mohd-Tajudin,＊2 R. Kobayashi,＊7,＊8
M.Sera,＊6 T. Nishioka,＊9 M. Matsumura,＊9 S. Sulaiman,＊2 M.I Mohamed-Ibrahim,＊2 and I. Watanabe＊1,＊2, ＊3, ＊4, ＊5
CeRu2Al10 has the orthorhombic YbFe2Al10-type structurewith space group Cmcm.1) Ce atoms control the magnetismof this system and are surrounded by Al atoms forminga cage-like structure which is suggested to form a twodimensional plane structure stacking along the b-axis.2,3)
Despite having the nearest neighbour distance,
approximately 5.2Å between Ce ions, CeRu2Al10 exhibits anantiferromagnetic transition at T0 = 27.3 K which cannot be
explained by taking only RKKY interaction into account. 4)
The magnetic susceptibility is largely anisotropic whereas
the direction of magnetic moment is along the c-axis and is
expected to flip to the a-axis when a small concentration of
Ru atoms are substituted by Rh atoms.5) In addition, fromthe µSR results of a Rh-doped system, Guo et al. reported
drastic changes in internal fields at muon sites whichwere related to the spin-flop caused by doping of 3% Rh
atoms in CeRu2Al10.6)
A number of investigations of muon sites in Ce-based
Kondo semiconductors, CeRu2Al10 and Ce(Ru, Rh)2Al10
were carried out by using Density Functional Theory (DFT)
to understand the magnetic properties. From the calculationof electrostatic potential, we found all muon sites previously
suggested by Kambe et al.7) and Khalyavin et al.8) as shownin Figure 1. Because they were not crystallographically
identical, muon sites in CeRu2Al10 are still undefined andthe hyperfine interactions cannot be discussed in detail.

Fig. 1. Muon sites in CeRu2Al10 suggested by Kambe etal.7) and Khalyavin et al. 8)†

Condensed from the article in J. Phys.: Conf. Ser. 551 012053 (2014)
RIKEN Nishina Center＊2
Computational Chemistry and Physics Laboratory, Universiti Sains
Malaysia＊3
Physics Department, Institut Teknologi Bandung＊4
Physics Department, Universitas Padjajaran＊5
Department of Physics and State Key Laboratory of Silicon Material,
Zhejiang University＊6
Department of Quantum Matter, Hiroshima University＊7
Quantum Condensed Matter Division, Oak Ridge National Laboratory＊8
Neutron Science Laboratory, University of Tokyo＊9
Graduate School of Integrated Arts and Science, Kochi University＊1

Fig. 2. Three planes that differentiate CeRu2Al10 (a) andCe(Ru, Rh)2Al10 (b). Planes (1) and (3) contain the muonsites suggested by Kambe et al., whereas the plane (2)contains the muon sites suggested by Khalyavin et al. In
plane (3), one Ru atom is substituted by one Rh atom.

Fig. 3. Potential differences between non-doped and doped
systems in planes (1), (2) and (3). The purple and yellow
points on the planes indicate the positions of suggested
muon sites.
The potential energies calculated for the plane in the nondoped system were subtracted from those of corresponding
plane in the doped system to investigate the potential
differences. Large differences are seen in plane (3) where a
Ru atom was substituted by a Rh atom. Because of thischange at the Rh atom in plane (3), the potential energy inplane (2) is also slightly deformed around the position
underneath the Rh atom. The large potential difference atthe substituted Rh atom in plane (3) may have been becauseof the difference in valence configuration from that of Ru
atom.
However, the potential energy at the suggested muonsites did not exhibit much difference even though the Rh
doping concentration in the CeRu2Al10 was increased to12.5%.
References

1) V. M. Thiede et al.: J. Mater. Chem. 8, 125 (1998).
2) H. Tanida et al.: Phys. Rev. B 84, 115128 (2011).
3) M. Sera et al.: J. Phys. Soc. Jpn. 82, 024603 (2013).
4) T. Nishioka et al.: J. Phys. Soc. Jpn. 78 123705 (2009).
5) A. Kondo et al.: J. Phys. Soc. Jpn. 82 054709 (2013).
6) H. Guo et al.: Phys. Rev. B 88 115206 (2013).
7) S. Kambe et al.: J. Phys. Soc. Jpn. 79, 053708 (2010).
8) D. D. Khalyavin et al.: Phys. Rev. B 82 100405 (2010).
- 269 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)SR study of the density wave state in -(BEDT-TTF)2MHg(SCN)4 (M=K, Rb)
K. Ichimura,＊1,＊2 K. Katono,＊2 and I. Watanabe＊1
Charge density wave (CDW) and spin density wave(SDW) are well-known ground states in low-dimensional
conductors and are based on different interactions. The
former is due to electron-phonon interaction and the latter isdue to on-site Coulomb interaction. Although manifests of
CDW and SDW have been discussed separately, thecoexistence of CDW and SDW is still an open problem.
In terms of the mixture of CDW and SDW, we focus onthelow-dimensionalorganic
conductor
-(BEDT-TTF)2MHg(SCN)4 (M=K, Rb). The compounds
undergo the density wave state at TDW= 8 and 12 K for K
and Rb-salt, respectively, as a consequence of the nesting of
Fermi surfaces. Commonly, organic conductors have too
little carrier density to screen the Coulomb interaction.
SDW was suggested by anisotropy of the magnetic
susceptibility1). On the other hand, CDW was suggested by
NMR2), in which no magnetic order was observed.
Accordingly, no clear evidence for the ground state of
-(BEDT-TTF)2MHg(SCN)4 has been obtained as yet. We
believe that this lack of evidence comes from thecoexistence of CDW and SDW. Such a mixture of CDW
and SDW forms a new ground state in low-dimensional
conductors, and is interesting in terms of g-ology3), which isa theoretical approach to ground states in one-dimensional
system. The present system is expected to be located at theboundary between CDW and SDW. To the best of ourknowledge, no study thus far has been able to determine
whether CDW and SDW coexist or compete with eachother.
For K-salt, Pratt et al.4) performed a zero-field SRmeasurement at a temperature range from 5 to 16 K. They
reported SDW ordering with an amplitude of 310-3 B.
However, this suggested value of the magnetic moment isextremely smaller than that of conventional SDW, for which
the amplitude is in the order of 0.1 B. In order tore-examine
thedensity
wave
state
in
-(BEDT-TTF)2MHg(SCN)4, we performed a SR
experiment at a lower temperature with higher statistics.
Small
flakesof
singlecrystalsof
-(BEDT-TTF)2MHg(SCN)4 (M=K, Rb) were grown by astandard electrochemical method with deuterated
BEDT-TTF molecules to eliminate the nuclear spin of
protons. In this experiment, we concentrated on Rb-salt,
which has a higher TDW than K-salt. The transition
temperature was determined as TDW= 12 K based on thetemperature dependence of the static magnetic susceptibility.
The powdered sample was mounted as a fly-past setup for a3
He refrigerator. The SR measurement was performed
down to 0.3 K.
＊1＊2

RIKEN Nishina Center
Department of Applied Physics, Hokkaido University

Fig. 1. Temperature dependence of asymmetry for
deuterated -(BEDT-TTF)2RbHg(SCN)4.

Figure 1 shows the temperature dependence of themuon-spin
precession
componentalongthelongitudinal-field (LF) of 20 G applied along the initial
spin-polarization of the injected muon. This component
reflects the existence of a static component obtained
from internal fields at the muon site in deuterated
-(BEDT-TTF)2RbHg(SCN)4. No drastic change wasobserved in the local field at TDW= 12 K. This tendency isqualitatively consistent with that obtained by Pratt et al.4).
At present, data accuracy is not considerably higher thanthat of Pratt et al. with large error bars. We will try to
improve the accuracy by collecting more muon events inthe next trial. This is expected to reduce the upper limitof the expected magnetic moment which has beensuggested by Pratt et al. to be 310-3 B following thesame logic4). On the other hand, we found an unusual
increase in the asymmetry below 2 K. This might be anindication of some degree of freedom or subphases5) in thedensity wave phase.
References

1) T. Sasaki, H. Sato and N. Toyota: Synth. Met. 41, 2211 (1991).
2) K. Miyagawa, A. Kawamoto and K. Kanoda: Phys. Rev. B 56,
14 (1997).
3) J. Solyom: Adv. Phys. 28, 201 (1979).
4) F. L. Pratt, T. Sasaki, N. Toyota and K. Nagamine: Phys. Rev.
Lett. 74, 3892 (1995).
5) A. Hoshikawa, K. Nomura, S. Takasaki, J. Yamada, S. Nakatsuji,
H. Anzai, M. Tokumoto and N. Kinoshita: J. Phys. Soc. Jpn. 69,
1457 (2000).

- 270 -

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)Stud
dy of couppling bettween eleectron co
onductionn and spiin fluctuaation
in novel organiic chargee transferr complexes withh TANC
*1,*2
*1
*1
*1
*2
M. Enomoto,*1,*2
Y. Furuya,*1
K
K. Isoda,*1
M. Tadokoro,*1
and I. Watanaabe*2

＊1
＊1
＊2
＊2

Department of C
Chemistry, Tokyoo University of Sccience
RIKEN Nishinaa Center

N

N

N

N

Figuure 1
(b)

(a)
(c)

Fig. 2. Crysstal structures oof {[Cu(TANC
C)](NO33)0.50.5}nn10.0
Depolarization rate (μs-11)

We have suucceeded to synthesizesorrganic conducctors
wiith
a
novel
electronn
accep
eptor,
5,6
6,11,12-tetraaazanaphthacenne (TANC; seee Figure 1). The
TA
ANC moleculle forms highhly conductiv
ve compoundds invaarious combinnations with metalmions. In particular, sevveral
Cu
u-TANC systeems are highlyy attractive coomplexes in teerms
off formation oof both π-electron condu
uctive bands andoordinating strructure betweeen the accep
ptor molecule andcocoopper spin ssites. Employying these propertiesp
iss animmportant approach to consstruct π-d intteraction systeems,suuch as the (DC
CNQI)22Cu syystem,1)1) wheree DCNQI dennotes
N,,N’-dicyanoquuinodiimine.
1.5+
In the case of [Cu1.5+(T
TANC)](NO33)0.5
00.5
0 , Cu ions andTA
ANC radicalss are alternateely linked thhrough coordiinate
intteraction betw
ween Cu-N atooms along thee b-axis, as shhown
in Fig. 2(a). These flat-ribbbon structuress stack with eachher to form 22D layers in thet ab-plane, while NO33 aanionothlayyers are segreegated from eaach Cu-TANC
C layers (see F
Figs.
1(b
b) and (c)). W
While the condductivity of th
his complex shhows
semiconductingg behavior, thee single crysttal exhibits a highonductivity off 50 S cm-1-1 at 300 K along the a-axis, w
whichco
is the stacking ddirection of thhe TANC molecules. Moreoover,onductivity shows highly annisotropic beh
havior, that is,, σ||aco
/ σ||bσ ~ 8.3, whhich correspoonds to the seegregated staccked
strructure of C
Cu-TANC 2D
D layers. Intterestingly, X
X-rayphhotoelectron sspectroscopy resultsrindicatte the coexisttence2+
off Cu++ and the Cu2+
at a 1 : 1 ratio in the Cu-TANC layyers.
Moreover,M
the innfrared reflectivity measureement revealss thateleectrons fluctuuate betweenn these two valence statees atcoopper ion sitess in both the directions off stacking (a-aaxis)annd flat-ribbon (b-axis) structtures.
t
TANC complex fam
mily,
On the othher hand, theAgg(TANC), alsoo forms a sim
milar conductiv
ve layer withoout acoounter anionn layer, succh as the NO33 layerr in
1.5+[CCu1.5+(TANC)]](NO33)0.5
Thhe anisotrop
pic conducttivity
0.5.
meeasurement ffor the Ag complexc
at roomrtemperaatureshhows that σσ||a / σ||b ~ 13, whiich reflects thelow
w-dimensionaal character ofo the Ag coomplex compparedwiith the Cu onne. Infrared reflectivityrstu
udy supports thisobbservation. Thhe reflectivity component, whichw
is norm
mal tothee stacking ddirection, is negligible,
n
while
w
the parrallelcoomponent cann be observeed similar too that in thee Cu
coomplex.
To understannd how electtron conduction occurs inn theTA
ANC complexxes, we carried out μSR measurementss on
1.5+[CCu1.5+(TANC)]](NO33)0.5
t depolarizaation
0.5. We found that the
1/2-1/2
ratte at 300 K iis proportionaal to -H1/2, whichw
suggestss theexxistence of thee 1D diffusionn behavior of spin-exciteds
sttates

1.0

100

1000

10000
0

0.1

0.0

Longituudinal field (OOe)
Fig.
F 3. The fieeld dependencce of the depolarization ratee
at
a 300 K.
(thee solid line in Fig. 2) rather than 2D diffuusion (the brokken
linee in Fig. 2). This behavior w
was also obseerved at 200 anda100
0 K. Since we have prediccted from ou
ur previous ligght
experiments thaat electrons are conducctive in thesehighh-temperaturee regions, thee present μSR
R results suppport
our prediction. At
A this momentt, we are not sureswhether thist2+
t Cu++ and Cu
C 2+
1D diffusion behavior occurs iin the line of thennection or in the direection of TANC
T
stacking.
conCom
mparison betw
ween the μSSR data of thet
Cu and Agcommplexes will an
nswer this queestion.
Refferences

1) A.
A Aumüller et all.: Angew. Chemm., Int. Ed. Engll. 25, 740 (19866).
2) F.
F L. Pratt et al.: Synth. Met., 855, 1747 (1997).
3) F.
F L. Pratt et al.: Hyperfine Inteeract., 104, 357 (1997).
4) N.
N Kojima et al.: Solid State Coommun., 120, 165
1 (2001).
5) N.
N Kida et al.: Phhys. Rev. B, 777, 14427 (2008)).

- 271 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)

Study of charge carrier transport in active layer P3HT:ZnO:PCBM hybrid
solar cells measured by muon spin relaxation†
L. Safriani,*1 Risdiana,*1 A. Bahtiar,*1 A. Aprilia,*1 and I. Watanabe*2†

Condensed from the article submitted to Materials Science Forum
Department of Physics, Padjadjaran University＊2
RIKEN Nishina Center＊1

P3HT:ZnO:PCBM at 15K

100 mT
50 mT

20

20 mT
10 mT
5 mT
2 mT

10

P3HT:ZnO:PCBM at 25K

30

395 mT
200 mT

395 mT
200 mT

Asymmetry

Asymmetry30

100 mT
50 mT

20

20 mT
10 mT
5 mT
2 mT

10

0 mT

0

0

2

4

6

0 mT

0

8

0

Time (sec)

2

4

6

8

Time (sec)

Fig. 1. The asymmetry data of P3HT:ZnO:PCBM at 15 K
and 25 K for various longitudinal magnetic fields.
Figure 2 shows the LF dependence of 1 in
P3HT:ZnO:PCBM, where 1 is the depolarization rate
associated with the fast component. At 15K, the relationship ~ H-0.5 is observed clearly, which indicate that onedimensional intra-chain diffusion occurs in this system.
Compared with the SR data for P3HT that show adimensional crossover at 25K,3) the data for
P3HT:ZnO:PCBM show the dimensional crossover fromone-dimensional to three-dimensional apparently at a lower
temperature. We cannot explain the experimental results
immediately, but they are likely related to the advantageous
properties of ZnO nanoparticles that facilitate electrontransfer.
101

101

P3HT:ZnO:PCBM
T = 15 K

100

P3HT:ZnO:PCBM
T = 25 K

100-1 (sec ) (sec-1)

Recently, many researchers have been making an effort toobtain high performance of solar cells by modifying theactive material of the solar cell. Conjugated polymers arepromising active materials. Much attention has been paid topolythiophene and its derivatives owing to their chemical
and thermal stability in addition to their potential to absorb
the solar spectrum in solar cells. Poly(3-hexylthiophene)(P3HT), a derivative of poly(3-alkylthiophene), presents thehighest hole mobility,1) thus attracting researchers’attention.
Hybrid solar cells that combine organic and inorganic
materials have been developed to increase the performanceof solar cells. P3HT having the highest hole mobility, whencombined with inorganic materials with the highest electron
mobility, shows promise for better performance. Zinc oxide(ZnO) is an inorganic material that has high electron
mobility and is easy to prepare. In bulk heterojunction
systems of solar cells, ZnO behaves as an electron acceptor
to dissociate excitons formed in P3HT. For practicalapplication to solar cells, ZnO nanoparticles are prepared toresolve the problem associated with the small diffusion
range of P3HT.2) Fullerene and its derivative [6,6]-phenyl
C61 butyric acid methyl ester (PCBM) are well-known
acceptor materials for polymer solar cells owing to theirability to transfer excitons from polymers within 45 fs.3)
In previous studies, ZF- and longitudinal-field (LF)-μSR
measurements were performed on samples of P3HT4) andP3HT:ZnO.5) For both the samples, it was found that charge
carrier transport changes from intra-chain to inter-chain
diffusion. For P3HT:ZnO, one-dimensional intra-chain
diffusion was observed at low temperatures, while
three-dimensional inter-chain diffusion was observed athigh temperatures.5) The addition of PCBM into the
P3HT:ZnO blend increased the charge transfer from P3HT
to ZnO and also reduced the aggregation of ZnO
nanoparticles.
To clarify the charge carrier dynamics in a bulk ternary
system of hybrid materials, we measured charge carriertransport using LF-SR in the P3HT:ZnO blend by adding afullerene derivative (PCBM).
Figure 1 shows the LF dependence of the raw asymmetryat 15 K and 25 K. The initial asymmetry increases withincreasing LF field owing to the repolarization of themuonium state.6) The raw asymmetries at 15 K and 25 K
show a clear dependence on field and temperature.

10-1
10-2

10-1
10-2
10-3

10-3
0

10

10

1

HLF (mT)

10

2

10

3

100

101

HLF (mT)

102

103

Fig. 2. The longitudinal-field dependence of the relaxation
rate 1 of P3HT:ZnO:PCBM at 15 K and 25 K.
With increasing temperature, the charge carrier transfer
changes from intra-chain to inter-chain diffusion.
One-dimensional intra-chain diffusion is observed in thesamplesattemperatures
below
15K,
while
three-dimensional inter-chain diffusion is observed attemperatures above 25 K.
References
1)
2)
3)
4)

W. Ma et al.: Adv. Funct. Mater. 15, 1617-1622 (2005)
L. W. Ji et al.: J Matter Sci. 45, 3266-3269 (2010)
G. Zerza et al.: Synth. Metals 119, 637 (2001)
R. Risdiana, et al.: Journal of Physics Conf. Series 200,
052024-052027 (2010)5) L. Safriani et al.: Adv. Mater. Res. 896, 477-480 (2014)6) F. L. Pratt: Philos.Mag. Lett. 75, 371-380 (1997)- 272 -

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)µSR study on antiferromagnetism in K-Rb alloy and Rb clusters in
sodalite
T. Nakano,∗1,∗2 K. Tanibe,∗1 L. M. Kien,∗1 S. Yoon,∗2,∗3 M. Abdel-Jawad,∗2 F. L. Pratt,∗4
I. Watanabe,∗2 and Y. Nozue∗1

∗1
∗2
∗3
∗4

Department of Physics, Osaka University
RIKEN Nishina Center
Department of Physics, The Catholic University of Korea
ISIS, Rutherford Appleton Laboratory- 273 -

a non-magnetic state is realized in the metallic phase
after the I-M transition.
(a)

(b)

s-electron

β cageSi
AlOA+
A43+ clusterin β cage~9Å

Fig. 1. Schematic illustrations of (a) the crystal structureof sodalite and (b) the A3+
4 cluster formed in the β cage,
where A indicates an alkali element.

Asymmetry (%)(a) 24(K1.7Rb2.3)

3+

150 K

20
16

5K
12

(b) 24
Asymmetry (%)

Porous crystals of zeolites make it possible to generate periodically arrayed alkali-metal nanoclusters.
Various kinds of magnetically ordered states have been
observed in these systems, although they do not contain any magnetic elements. Sodalite is a kind of aluminosilicate zeolites where the β cages with an innerdiameter of ≅ 7 Å are arrayed in a bcc structure asshown in Fig. 1 (a). The chemical formula is given by
A3 Al3 Si3 O12 per β cage where A indicates an alkali
cation. By the loading of guest alkali atoms into dehydrated sodalite, an A3+
cluster is formed in the β4cage as schematically shown in Fig. 1 (b), where an selectron is shared by four A+ ions and is conﬁned in
the cage. When Na3+
4 clusters are formed in all the βcages, antiferromagnetic (AFM) ordering occurs below
the Néel temperature of TN = 48 K1–3) because of theexchange coupling between the adjacent clusters. The
material is assigned to a Mott insulator. When heavier
alkali cations are substituted for Na+ , TN systematically increases: 72, 80, and 90-100 K for clusters with3+
average chemical compositions of K3+, and
4 , (K3 Rb)
3+4,5)(K1.5 Rb2.5 ) , respectively.
However, a recent work
has revealed that Rb3+
does not show AFM order4
ing and shows metallic behavior. In the present work,
we investigate in detail the magnetic properties of thissystem in the vicinity of the insulator-to-metal (I-M)
transition by utilizing µSR. The experiments were performed at the RIKEN-RAL Muon Facility using the
CHRONUS spectrometer.
Figure 2 (a) shows the zero-ﬁeld µSR spectra of KRb alloy clusters ((K1.7 Rb2.3 )3+ ). At 5 K, a muon-spin
precession signal with a large amplitude is clearly observed. This result indicates that the AFM order isrobust in the major volume of the sample even just before the I-M transition. The internal ﬁeld at the muonsite is estimated to be 166 Oe. This is stronger than3+
2)
3+that in Na3+
4 (92 Oe) , K4 (142 Oe), and (K3 Rb)
4)(155 Oe) . A systematic increase in the size of thes-electron wave function in the heavier alkali metals,
which is the origin of the enhancement of AFM exchange interaction, is expected to provide a stronger
Fermi contact between muon and s-electron. TN is estimated to be ≅ 90 K from the temperature dependence of the internal ﬁeld. In contrast, the pure Rb
clusters (Rb3+
4 ) only show very slow relaxation even at
2 K as shown in Fig. 2 (b). This result conﬁrms that

Rb4

3+

80 K

20
16

2K

12
0.0

0.5

1.0

1.5

2.0

2.5

3.0

Time (µs)

Fig. 2. Zero-ﬁeld µSR spectra of (a) K-Rb alloy clustersand (b) Rb clusters in sodalite.

References
1) V. I. Srdanov, G. D. Stucky, E. Lippmaa, and G. Engelhardt: Phys. Rev. Lett. 80, 2449 (1998).
2) R. Scheuermann, E. Roduner, G. Engelhardt, H.H. Klauss, and D. Herlach: Phys. Rev. B 66, 144429(2002).
3) T. Nakano, M. Matsuura, A. Hanazawa, K. Hirota, and
Y. Nozue: Phys. Rev. Lett. 109, 167208 (2012).
4) T. Nakano, R. Suehiro, A. Hanazawa, K. Watanabe,
I. Watanabe, A. Amato, F. L. Pratt, and Y. Nozue: J.
Phys. Soc. Jpn. 79, 073707 (2010).
5) T. Nakano, Y. Ishida, A. Hanazawa, and Y. Nozue: J.
Kor. Phys. Soc. 62, 2197 (2013).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)

Li-ion diﬀusion in Lix FePO4 with x = 0, 0.25 and 0.5
I. Umegaki,∗1 M. Månsson,∗2 H. Nozaki,∗1 G. Kobayashi,∗3 R. Kanno,∗4 H. Guo,∗5 K. Ishida,∗5 I. Watanabe,∗5
and J. Sugiyama∗1

∗1
∗2
∗3
∗4
∗5

Toyota Central Research and Development Labs., Inc.
Material Physics, Royal Institute of Technology
Institute for Molecular Science
Department of Electronic Chemistry, Tokyo Institute ofTechnology
RIKEN Nishina Center- 274 -AP0 (t)(a)T = 125 K

ZF
LF=5 G

AP0 (t)(b)T = 175 K
TIME [µ s]ZF
LF=5 G

AP0 (t)(c)T = 250 K
TIME [µ s]ZF
LF=5 G

TIME [µs]Fig. 1. ZF- and LF-µ+ SR spectra on FePO4 at (a) 125 K,(b) 175 K, and (c) 250 K.
LixFePO4

6

Temperature [K]LixFePO46

x=0
x=0.25x=0.5

ν [10 /s](a) ∆∆ [10 /s]

Lithium iron phosphate, LiFePO4 , is used as a cathode material in Li-ion batteries. A comparison withthe conventional cathode materials such as LiCoO2 ,LiNiO2 , and LiMn2 O4 showed that LiFePO4 has a
special advantage over because of its high stability
during the lithium extraction/intercalation reaction at
medium temperatures (around 400 K).
Based on electrochemical1,2) and structural analyses,3)
the lithium extraction reaction from LiFePO4 is represented as follows: LiFePO4 - xLi → (1 − x)LiFePO4+ xFePO4 . Both LiFePO4 and FePO4 phases coexist
in Lix FePO4 , and single phase samples of Lix FePO4
have not been obtained so far. Following upon theµ+ SR work on LiFePO4 ,4) we have measured µ+ SR
spectra on Lix FePO4 (x = 0, 0.25, and 0.5) in order tounderstand the diﬀusive property shown in Lix FePO4
sample consisting of the two phases.
Powder samples of Lix FePO4 were prepared from
LiFePO4 by reacting it with NO2 BF2 in acetonitrile.
Then, the Li-deﬁcient powder sample was sealed intoa titanium cell with a gold o-ring. The window of thecell was made of a Kapton ﬁlm of 50 µm thickness.
The cell was mounted onto the Cu plate of a liquid-He
ﬂow-type cryostat in the temperature range between
10 and 400 K.
Figure 1 shows the temperature dependence of zeroﬁeld (ZF-) and longitudinal ﬁeld (LF-) µ+ SR spectra for FePO4 . Since there is no crucial change withtemperature, the implanted muons are static up to250 K. In fact, the spectra were ﬁtted by a combinationof a dynamic Kubo-Toyabe (KT) signal and a timeindependent background signal from a powder cell.
The ﬁeld distribution width (∆) and the ﬁeld ﬂuctuation (ν) were found to be independent of temperature;∆FePO4 = 7.1 × 104 s−1 and νFePO4 = 2.6 × 104 s−1 .
On the other hand, dynamic behavior was clearlyobserved for Li0.25 FePO4 and Li0.5 FePO4 . The µ+ SR
spectra were well ﬁtted by a combination of two KT
signals and a background signal. The two KT signals
came from the muons stopped in the LiFePO4 phaseand those in the FePO4 phase. Therefore, we used thesame values of ∆FePO4 and νFePO4 for the KT signal
from the FePO4 phase. Figure 2 shows the temperature dependence of ∆ and ν for the three samples. As
expected, the result is very consistent with that obtained for LiFePO4 . Assuming that the Li-ion jump to

(b) ν

x=0
x=0.25x=0.5

Temperature [K]Fig. 2. Temperature dependence of (a) ∆ and (b) ν obtained for FePO4 , Li0.25 FePO4 , and Li0.5 FePO4 .

interstitial sites,4) we obtained the diﬀusion coeﬃcient
as: DLi = 5.8 × 10−11 cm2 /s at 200 K for Li0.5 FePO4
and DLi = 1.3 × 10−11 cm2 /s for Li0.25 FePO4 . These
values are smaller than DLi for LiFePO4 ,4) implying
the eﬀect of Li-ion diﬀusion between the LiFePO4 andFePO4 phases. Such interphase diﬀusion is believed tobe the most interesting process shown in the LiFePO4
cathode. In order to understand the interphase Li-ion
diﬀusion, however, we need to study the relationshipbetween DLi and x in Lix FePO4 in more detail.
References
1) A. K. Pahdi et al.: J. Electrochem. Soc. 144, 1188
(1997).
2) W. -J. Zhang.: J. Power Sources, 196, 2962 (2011).
3) A. Yamada et al.: J. Electrochem. Socl. 148, A224
(2001).
4) J. Sugiyama et al.: Phys. Rev. Lett. 103, 147601 (2009).

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)

Investigations of defects in TiO2 rutile crystal by muon and muonium
H. Ariga,∗1∗2 K. Asakura,∗1 K. Shimomura,∗3 K. Ishida,∗2 F. Platt,∗4 W. Higemoto,∗5 E. Torikai,∗6
A. D. Pant,∗6 K. Yokoyama,∗7 B. Ohtani,∗1 and K. Nagamine∗8
Metal oxides play a key role in the ﬁeld of environmental science, heterogeneous catalysis, electrochemistry, biology, chemical sensors, magnetism, and otherchemical processes. It is well known that the existence of defect sites drastically changes the chemicaland physical properties of metal oxides. TiO2 is theone of the most studied material among metal oxides.
The defect sites in TiO2 aﬀect the catalytic and photocatalytic properties. The structure of defect site on
surface is well known by scanning probe microscope(STM, AFM and so on) observations. The major defect on the surface is oxygen vacancy. However, themicroscopic insight of bulk defect sites has not been
established yet. Although oxygen vacancy is believed
to be a typical defect site in TiO2 , no direct evidence
has been reported to characterize the defect structure,and its properties have not been revealed because of
the diﬃculty in detecting defects directly. In orderto establish a charge balance, Ti3+ is assumed in thenearest neighbor of the bulk oxygen vacancy. Thus,
oxygen vacancy has been discussed by measuring Ti3+
species, which have one d electron and are characterized with ESR or NMR techniques. However, since
Ti3+ species do not only exist next to the oxygen vacancies but also at other sites such as interstitial Ti,
planar defects, CS planes and so on, it is necessary toobtain information including the adjacent morphology
of Ti3+ . It is suggested that hydrogen stabilizes at anoxygen vacancy as hydrid (H− ) in TiO2 through density functional calculations. As Muon is regarded as
an isotope of hydrogen, µSR has potential to be theprobe of oxygen vacancy.
Our recent preliminary TF µSR measurements at
the RIKEN-RAL suggested the existence of a large
fraction of a diamagnetic component (µ+ orM u− ) andsome normal muonium at room temperature in TiO2
with an oxygen vacancy. The purpose of the present
work is to clarify whether negative muonium ions exist
in TiO2 with an oxygen vacancy by laser irradiation
and also to determine a further detailed state of µ+ .
We have performed both zero-ﬁeld (ZF) measurements and “Pump and probe” measurements by laser
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Catalysis Research Center, Hokkaido University
RIKEN Nishina Center
Insittue of Material Structure Science, KEK
ISIS Science and Technology Facilities Council, Rutherford
Appleton Laboratory
Advanced Science Research Center, Japan Atomic Energy
AgencyDepartment of Research Interdisciplinary Graduate Schoolof Medicine and Engineering, University of Yamanashi
ISIS/Qween Marry Univeersity
UC-Riverside- 275 -

irradiation at various temperatures. The µSR measurements were performed at the RIKEN-RAL Muon
Facility. The mirror-polished rutile TiO2 single crystals (25 x 25 x 0.5 mm3 , Crystal Base, Japan) oriented
to the (110) plane were used. The sample was calcinedat 1073 K for 6 h in air followed by reduction at 1173 K
for 2 h under an ultra-high vacuum environment (0.5
x 10−8 Pa). The color of sample became blue after
the reduction procedure. Laser was irradiated fromthe opposite side of muon through a quartz glass byutilizing the sample cell developed by Prof. Torikai’sgroup.
The ZF muon spin relaxation spectra with and without oxygen vacancies are obtained at various temperatures from 15 K to room temperature. The diﬀerence
between two samples are observed at a temperature
lower than 50 K. The spectra at 15 K are shown in
Fig. 1. The relaxation of spectra without an oxygen
vacancy is predictable to be derived from nuclear spinsof Ti (47 Ti and 49 Ti) because of the absence of electronic spin. We expected a Gaussian ﬁeld proﬁle andﬁtted the plot with a Kubo-Toyabe relaxation function. The spectra without the oxygen vacancy waswell ﬁtted with ∆ = 0.30 MHz (Gaussian distribution:
0.71 mT), which is a typical value for nuclear spins.
The Kubo-Toyabe relaxation function for a Lorentzianﬁeld distribution was added for ﬁtting the relaxationof spectra with the oxygen vacancy. The ∆ value andthe Lorentzian distribution were 0.38 MHz and 1.9 mT,
respectively.
We have also preformed pump and probe measurements to examine the existence of Mu− . The “pump”
laser irradiation is intended to remove one electronfrom the negative muonium ion, which makes the ion
detectable by a transverse-ﬁeld measurement. However, we could not detect obvious diﬀerences in the results obtained with and without laser irradiation. The
remaining issue is to simulate the dynamics of Mu− bylaser irradiation and determine an approach to detect
Mu− .

Fig. 1. Zero field µSR spectrum of rutile TiO2 (a) with and(b) without oxygen vacancy at 15 K.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)

Response of muonium to oxygen contents in hemoglobin and other biologicalaqueous solutions for cancer research
K. Nagamine,*1, *2, *3 A.D. Pant, *4 I. Shiraki, *4 E. Torikai,*4 K.Shimomura, *3 F.L. Pratt, *5 H. Ariga, *6 K. Ishida, *7
and J.S. Schultz *7
Hypoxia, or low oxygenation, is known as an importantfactor in tumor biology; in cancer patients, an accurate
measurement of O2 concentration (c(O2)) or partial pressurein specific regions is critical1) therefore, improved methods
for detecting O2 are required. Several trials that employ PET,
MRI and EPR have been conducted1).
We have proposed the use of + as a new sensitive
method to probe the existence of paramagnetic O2 in cancer
tumors in the human body. The + in water is known totake the states of diamagnetic + such as +OH (60%),
paramagnetic muonium (Mu, + + e-) (20%), and a missing
fraction (20%). In Mu, 50% fraction becomes an ortho statewith spin 1, providing a spin rotation signal with aprecession pattern (1.39 MHz/G) that is 100 times fasterthan that of diamagnetic +. Some experimental studies
have been conducted on the oxygen-dissolving effects ofthe spin relaxation rate (λMu) of paramagnetic Mu in purewater due to electron spin exchange interactions withparamagnetic O2 in water; the rate change of λMu againstc(O2) is (1.8 ± 0.1) ×1010 (L/mol)/s 2). A problem thatremains to be solved is the effect of other magnetic
molecules, which is the objective of the present study.
Experiment was conducted at Port 2 of RIKEN-RAL
using 60 MeV/c decay . Spin rotation and relaxation weredetected under 2.2 G transverse fields at room temperature.
The biological samples used were as follows: 1)
Albumin; Bovin serum (plasma) albumin 2) Serum; Donor
horse serum 3) Hemoglobin (Hb); Polymerized hemoglobinof bovine origin in a lactated Ringer’s solution at 13%
concentration in the form of deoxy-Hb.
Before measuring the O2 dependence of λMu, its
dependence on the concentration of each biologicalmolecule was systematically measured. The increasing ratesof λMu were obtained as 25 s1/(g/L) for albumin, 1s1/(vol.%) for serum and 3.1s1/(g/L) for Hb.
Then, by determining the relevant concentration foreach molecule, the O2 dependence of λMu was measured. In
these biological aqueous solutions, λMu showed an almost
similar change in relaxation against increasing O2
concentration as that for pure water.
For higher Hb concentrations, by introducing O2, a partof deoxy-Hb (magnetic) becomes oxy-Hb (non-magnetic)so that the O2 dependence of λMu becomes non-linear.
*1

Atomic Physics Laboratory, RIKEN
Physics & Astronomy, University of California, Riverside*3
Muon Science Laboratory, IMSS, KEK*4Medicine and Engineering, University of Yamanashi*5
ISIS, Rutherford Appleton Laboratory*6
Catalysis Research Center, Hokkaido University*7
RIKEN Nishina Center*8
Bio-Engineering, University of California, Riverside*2

Measurements were made upto 2.0 g/L c(Hb) and 20%
c(O2) (Fig. 1). The O2 dependence of λMu at higher Hbconcentrations was predicted by assuming the following
relation3): λMu = RHb(Mu) + RO2(Mu). There, RHb(Mu) is therelaxation rate due to the amount of deoxy-Hb obtained bysolving the Hill’s equation for the total Hb amount andc(O2) 4), while RO2(Mu) is the relaxation rate due to the freemolecular O2 in solution obtained by the O2 dependence
data of the pure water and by the amount of free O2 whichis estimated by subtracting the O2 amount used for oxy-Hbformation obtained by the Hill’s equation. As summarized
in Fig. 1, λMu increases with increasing Hb at any fixedc(O2); slower increasing rate at Hb higher than 1 g/L due tooxy-Hb formation. The λMu becomes undetectably large (≥10 s1) at c(O2) lower than 6% at higher c(Hb) of 100 g/L
expected for human body.
Before carrying out the clinical application of the
proposed method to studies on hypoxia, it is important to
conduct further systematic studies on the behavior of O2 invarious other biological aqueous systems, especially withhigh-concentration Hb. Significant features of the present
muon method can be summarized as follows: a)
non-invasive nature, b) no need of a high magnetic field andc) sub-mm probing region confinement by the advanced
beam method.5)

Fig. 1 Summary of dependence on O2 concentration of muonium
relaxation rates in Hb aqueous solution; experimental data upto
2.0 g/L and predictions upto 150 g/L by the method described in
the text.

References

1) J.L. Tatum et al., Int. J. Radiat. Biol., 82, 699 (2006).
2) E. Roduner et al., J. Chem. Faraday Trans., 91, 1935 (1995).
3) A.D. Pant et al., J. Phys.: Conf. Series, 551, (2014) 012043.
4) M. Samaja et al., Clin. Chem., 20, 110 (1983).
5) K. Nagamine, JPS Conf. Proc., 2, 010001 (2014).

- 276 -

Ⅲ-2. Atomic & Solid State Physics (Muon)

RIKEN Accel. Prog. Rep. 48 (2015)

Development of gas system for MuSEUM experiment
K. S. Tanaka∗1,∗2 on behalf of J-PARC MuSEUM Collaboration
We are planning to measure the energy of groundstate hyperﬁne structure (HFS) of muonium at JPARC/MLF. Muonium is a hydrogen-like bound statethat consists only leptons, and its HFS is a good probe
for testing the QED theory. The latest experiment at
LAMPF obtained the following value:1)
ex∆HF SM= 4.463302765(53) GHz (12 ppb) .

∗2

RF cavity

CCD camera(1)

The total uncertainties were determined using the statistical uncertainties. We will achieve an accuracy
more than 10 times greater than that of the latest experiment by using the H-line at J-PARC.
Muons polarized in the revese direction of momentum enter the bore of a large superconducting solenoid
magnet from the J-PARC/MLF muon beamline. A RF
cavity is located at the center of the magnet containing pure Kr gas. Muons stop by collisions in the gas,and polarized muoniums are formed by the electron
capture process.
In a magnetic ﬁeld the ground state splits into four
substates. ν12 and ν34 are obtained by the microwave
magnetic resonance technique. High-momentum decay positrons are emitted preferentially in the direction of the muon spin. By driving the transitions with
an applied microwave magnetic ﬁeld perpendicular tothe static magnetic ﬁeld, the muon spin can be reversed and the angular distribution of high-momentum
positrons changes from predominantly upstream todownstream with respect to the beam direction. The
cavity was designed to be resonant simultaneously in
the TM110 mode at the ν12 transition frequency andin the TM210 mode at the ν34 frequency2) . The muonium HFS (∆ν) is obtained by summing ν12 and ν34 .
A Gas chamber surrounds the RF cavity to seal
in the Kr gas. The chamber consists of only aluminum and its upstream foil is thin enough (100 µm)
for muons to pass through. We performed gas introduction tests in the chamber. The gas pressure ismonitored at the 0.02 % level by a silicon pressuretransducer. The gas in this system is sampled regularly by small cylinders. Since spin-exchange collisions occur between muonium and paramagnetic contaminant particular oxygen, we intend to determine
the purity of a gas at the parts per million level using Q-mass. We studied the performance of the gas
panel without gas sampling and precise gas pressure
monitoring on November 2014 (Fig. 1). In this test,
we measured muonium distributions under several gas
pressures (Fig. 2). The gas pressure in the chamber
maintain a steady at sub Torr level during this measurement.
∗1

Gas panel

Gas chamber

RIKEN Nishina Center
Graduate School of Arts and Sciences, University of Tokyo- 277 -

Fig. 1. Experimental setup at 2014A beamtest. The gaschamber is mounted on the support rail. The gas panel
is behind the gas chamber.

0.1 atm

0.3 atm

0.7 atm

1.0 atm

0.5 atm

Fig. 2. Muonium distributions at the center of the chamber
for diﬀerent gas pressures.

References
1) W. Liu et al.: Phys. Rev. Lett. 82, 711 (1999)
2) K. S. Tanaka on behalf of MuSEUM Collaboration K.
S. Tanaka et al.:, JPS Conf. Proc. 2, 010405 (2014)

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)

Development of online muon beam profile monitor for the MuSEUM
experiment
S. Kanda∗1,∗2 for the MuSEUM Collaboration
Muonium is the bound state of a positive muon andan electron. Because neither muon nor electron has
an internal structure, muonium ground state hyperﬁnesplitting (MuHFS) can be the most precise probe forthe test of the bound state QED and for the determination of muon mass via the ratio of magnetic moments ofa muon and a proton. At J-PARC, we plan to performa precision measurement of the MuHFS by microwave
spectroscopy of muonium. Spectroscopy of the energy
states is performed by measurement of positron asymmetry from muonium decays. Our goal is to improve
the precision by an order of magnitude compared withthat of the most recent experiment. In order to achieve
the goal, we utilize J-PARC’s highest-intensity pulsed
muon beam2) , highly segmented positron detector with
Silicon PhotoMultiplier(SiPM)3) , and an online/oﬄine
muon beam proﬁle monitor.
The online muon beam proﬁle monitor analyses themuon beam from the aspect of beam shape and relative
intensity. Requirements for the beam proﬁle monitor
are minimum destruction and high reconﬁgurability ofthe beam. We utilize thin plastic scintillation ﬁber
and SiPM. Figure 1 shows the conceptual design ofthe muon beam proﬁle monitor. The detector consistsof an one dimensional array of thin plastic scintillation
ﬁber with a 100 µm diameter. The ﬁbers are boundinto a bundle and connected to a SiPM. For a front-end
electronics, EASIROC front-end chip4) was utilized as
an ASD (ampliﬁer, shaper, and discriminator). The
pulse height is digitized by an external peak holding
ADC.

Figure 2 shows the developed prototype and its
cross-sectional view. The ﬁbers were arrayed on a polyimide ﬁlm of 25 µm thickness and bonded by epoxy
resin. Forty ﬁbers were bound into one band of 4 mm
width. Two bands were arrayed with a 2 mm gap.
In November 2014, a beam test was performed at

Fig. 2. Developed prototype of the online muon beam profile monitor

J-PARC MLF MUSE D2 beam line. Figure 3 shows
the measured photon yield as a function of total muon
beam intensity. Saturation in higher intensity region iscaused by the limited number of SiPM pixels (in case ofthis prototype, number of pixels was 667). The beam
intensity was controlled by movable slits and measured
by an oﬄine beam proﬁle monitor5) , which consists ofa gated image intensiﬁer and a cooled CCD. The movable slits only change beam density and keep beam proﬁle unchanged. Based on the result of the beam test,
the design of a full-scale detector is in progress. SiPM
with narrower pixel pitch will be used and process ofﬁber bonding will be optimized for uniform thickness.

Fig. 3. Measured photon yieldFig. 1. Conceptual design of the online muon beam profile
monitor∗1∗2

Department of Physics, University of Tokyo
RIKEN Nishina Center- 278 -

References
1) W. Liu et al.: Phys. Rev. Lett. 82 (1999) 711
2) A. Toyoda et al.: J. Phys. Conf. Ser. 408 (2013) 012073
3) S. Kanda et al.: JPS Conf. Proc. 2 (2014) 010404
4) S. Callier et al.: Physics Procedia 37 (2012) 1569
5) T. U. Ito et al.: NIM A 754 (2014)

3. Radiochemistry and Nuclear ChemistryⅢ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Reversed-phase extraction behavior of the 105th element, Db, withtributyl phosphate
M. Murakami,∗1,∗2 S. Tsuto,∗1 K. Ooe,∗1 S. Goto,∗1 D. Sato,∗1 N. Goto,∗1 T. Koyama,∗1 T. Nagaoka,∗1
R. Motoyama,∗1 H. Haba,∗2 Y. Komori,∗2 A. Toyoshima,∗3 A. Mitsukai,∗3,∗4 Y. Kitayama,∗5 Y. Fukuda,∗5
and H. Kudo∗1

∗1

∗2
∗3

∗4

∗5

Department of Chemistry, Niigata University
RIKEN Nishina Center
Advanced Science Research Center, Japan Atomic Energy
AgencyFaculty of Science, Ibaraki University
Graduate School of Natural Science and Technology,
Kanazawa University- 279 -

8.74 MeV) for 262 Db and its α-decay daughter 258 Lr(T1/2 = 3.9 s), 16 and 2 events were observed in
Fractions 1 and 2, respectively, including one timecorelated α pair in Fraction 1. The chemical yield of
170
Ta, including deposition and dissolution efficienciesof the aerosols, was 44 ± 13%.
Percent extraction (%Ext) values were evaluated using the equation
100A2
,
(1)
%Ext =
A1 + A2
where A1 and A2 are the radioactivities in Fractions 1
and 2, respectively. The correction for the radioactive
decay was considered for A1 and A2 . In Fig. 1, theobtained %Ext values of 262 Db and 170 Ta are shownas closed symbols, together with those of 90g Nb and178aTa (open symbols) obtained in the separate experiment,2) as a function of the initial HF concentration,[HF]ini . Because of the small number of the 262 Db
events in Fraction 2, an upper-limit %Ext value of ≤25% was evaluated for 262 Db. The evaluated %Ext
value for 170 Ta was 93 ± 5%, which was in agreement with the previous result for 178a Ta (%Ext = 94
± 4%2) ). This suggests that Db would not form a Talike fluoride complex [DbF6 ]− in 1.0 M HF, where Ta
forms an extractable species, [HTaF6 (TBP)3 ].5)
262
248
19
262
248
19
Db
Cm +
+19
F)
Db ((nat
Cm
F)
170
nat
19
170
Ta (( Gd
Ta
Gd +
+ F)
F)
90g
90g
nat
Nb ((nat
Zr
+
d)
Nb
Zr
+
d)
178a
nat
178a
nat

100
100

Ta (( Hf
Ta
Hf +
+ d)
d)

%Ext
%Ext

Our group has investigated the extraction behaviorof Nb and Ta, homologs of the 105th element Db, from
HF solutions with tributyl phosphate (TBP) by thebatchwise and on-line column chromatographic methods.1,2) In the on-line column experiment with a 62
wt% TBP resin,2) the obtained distribution coefficients(Kd ) of Ta were in agreement with those obtained by
the batch experiment, indicating that the studied system can be applicable to the column chromatographic
experiment with the short-lived 262 Db (T1/2 = 33.8 s).
In this work, the extraction behavior of Db was studied to discuss the chemical form of Db in HF media bycomparing the behavior of Nb and Ta.
The isotopes 262 Db and 170 Ta (T1/2 = 6.76 min)were simultaneously produced in the bombardment of
a 19 F beam on the mixed 248 Cm/nat Gd target. The
19
F beam was delivered from the AVF cyclotron, andits energy was 105.3 MeV at the center of the target. The typical beam intensity was 700 particle-nA.
The reaction products were transported with a He/KCl
gas-jet system to a chemistry laboratory and were deposited on a collection site in Automated Rapid Chemistry Apparatus (ARCA3) ) for 80 s. Then, the products were dissolved in 140 µL of 1.0 M HF and were
loaded onto a column (1.6 mm i.d. × 7.0 mm height)
filled with the 62 wt% TBP resin. The flow rate of theeluent was 1.0 mL/min. The effluent was collected in a
Ta dish as Fraction 1. The remaining products in thecolumn were stripped with 140 µL of 10 M HF at aflow rate of 1.0 mL/min, and the effluent was collectedin another Ta dish as Fraction 2. Both effluent fractions in the Ta dishes were evaporated to dryness andsubjected to α spectrometry using an automated rapid
α/SF detection system.4) The α-particle measurement
was started at 43 s and 57 s after the collection of
the products for Fractions 1 and 2, respectively. The
counting duration was 259 s and 248 s for Fractions 1
and 2, respectively. After the α-particle measurement,
every third or fifth pair of Ta dishes was subjected to
γ-ray spectrometry to monitor the behavior of 170 Ta
and its chemical yield.
In total, 820 cycles of chromatographic separation
were conducted. In the α energy region (Eα = 8.42–

50
50

00

1000
10

[HF]ini(M)[HF]
ini (M)

1011
10

Fig. 1. Dependence of %Ext values of Nb, Ta, and Db on[HF]ini .

References(2014).
1) S. Tsuto et al.: RIKEN Accel. Prog. Rep. 47, 270
in press.
2) M. Murakami et al.: In this report.
3) Y. Nagame et al.: Radiochim. Acta 93, 519 (2005).
4) H. Haba et al.: RIKEN Accel. Prog. Rep. 45, 204(2012).
5) Z. Zhu and C. Y. Cheng: Hydrometallurgy 107, 1(2011).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Solid-liquid extraction of 261Rf from hydrochloric acid with Aliquat 336 resin
T. Yokokita,＊1,＊2 Y. Kasamatsu,＊2 Y. Shigekawa,＊1,＊2 Y. Yasuda,＊1,＊2 K. Nakamura,＊1,＊2 H. Haba,＊1 Y. Komori,＊1
M. Murakami,＊1 and A. Shinohara＊1,＊2
The chemical properties of transactinide elements(atomic numbers Z ≥ 104) are considered to differ fromthose of its homologues because of the increasingly strong
relativistic effects on the valence shell electrons of heavy
atoms. The transactinide nuclei are produced at accelerators
using heavy-ion-induced nuclear reactions. These nuclei
have low production rates and short half-lives (T1/2 ≤ ~1min). Therefore, the chemical experiments of transactinides
must be carried out rapidly on one-atom-at-a-time basis
using nuclear reaction products transported from the target
chamber by a He/KCl gas-jet system. The chemical
properties of transactinides have so far been investigatedmainly by a partition method based on a comparison of theirchemical behavior with those of lighter homologous
elements.
Solution chemistry experiments have been often
conducted on element 104, rutherfordium (Rf). Anion- andcation-exchange experiments of Rf in HF and HF/HNO3
were successfully performed under conditions such that the
distribution behaviors in equilibria were observed for thehomologues of Rf. Clearly different behavior of Rf from its
homologues Zr and Hf was reported.1) On the other hand, inthe cation exchange in H2SO4/HNO3, the Kd values of Hf in
the online experiment were in good agreement with those in
the offline batch experiment, whereas the Kd values of Zr in
the online experiment were not.2) Therefore, it is important
to investigate the time dependence of the distribution
behaviors of transactinides to obtain their equilibrated data
because the time required to reach distribution equilibrium
would be different among homologues. Thus, we developed
a batch-type solid-liquid extraction apparatus to evaluate
the time dependence of the distribution behavior of Rf andto obtain the equilibrated Kd values.3) To determine theexperimental condition and obtain comparison data for Rf,
we also performed solid-liquid extraction of Zr and Hf andTh (pseudo homologue) with a quaternary ammonium
chloride, Aliquat 336, from HCl.4) In this work, we
performed an online solid-liquid extraction experiment on
261
Rf and 169Hf using the developed apparatus at RIKEN.
The 261Rf (T1/2 = 68 s) and 169Hf (T1/2 = 3.25 min)nuclides were produced in the 248Cm(18O,5n)261Rf andnat
Gd(18O,xn)169Hf reactions, respectively, by the RIKEN
K70 AVF cyclotron. The nuclear reaction products thatrecoiled out from the target were caught by KCl aerosols in
He gas and were transported by the gas-jet system to thechemistry laboratory. In the solid-liquid extraction
experiments, the reaction products in the gas-jet were
deposited on a collection site on a dissolution apparatus.
＊1＊2

RIKEN Nishina Center
Graduate School of Science, Osaka University

Then, the deposited sample was dissolved in about 0.25 mL
of 7.9 and 9.0 M HCl. The solution sample entered thechemical reaction container containing the 28 wt% Aliquat
336 resin (1.11–1.62 mg). After shaking the container witha vortex mixer for 10–60 s, only the solution phase waspushed out of the container by compressed air and collectedon the Ta dish. Then the solution sample was evaporated todryness with hot He gas and a halogen lamp to prepare asample for α-spectrometry. Subsequently, the Ta dish wastransferred to a Si PIN photodiode detector, and α-particle
measurement was performed. After the measurement, theγ-ray activity of 169Hf was monitored using a Ge detector todetermine its Kd value and chemical yield.
In Fig. 1, the Kd values of Zr, Hf, and Th with the 28wt%
Aliquat 336 resin4) are shown as a function of the HClconcentration. The Kd values of Hf in this work wereconsistent with those in the offline batch experiment (≥4 hof shaking), indicating that the Kd values of Hf in equilibria
could be obtained using batch-type solid-liquid extraction
apparatus. The 24 and 3 α events were observed in theexperiments at 7.9 M HCl (38 extractions, chemical yield:
56%) and at 9.0 M HCl (68 extractions, chemical yield:47%), respectively, in the α energy region of 261Rf and its
daughter 257No. The detected α counts for eluent clearlydecreased with an increase in the HCl concentration. Thissuggests that Rf forms anionic chloride complexes with Cl−
ions, similar to the case of Zr and Hf and different from thecase of Th. The present results are consistent with theprevious report.5) We will report the Kd values of Rf in thepresent experiment in the future.

Fig. 1. The Kd values of Zr, Hf, and Th as a function of theHCl concentration with 28 wt% Aliquat 336 resin.
References

1) Y. Ishii et al.: Bull. Chem. Soc. Jpn. 84, 903 (2011).
2) Z. J. Li et al.: Radiochim. Acta 100, 157 (2012).
3) A. Kino et al.: RIKEN Accel. Prog. Rep. 46, 241 (2013).
4) T. Yokokita et al.: 6th International Conference of Ion Exchange,
Ginowan, November 12 (2014).
5) H. Haba et al.: J. Nucl. Radiochem. Sci. 3, 143 (2002).

- 280 -

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Extraction behavior of rutherfordium as a cationic fluoride complex
with a 2-thenoyltrifluoroacetone chelate extractant from HF/HNO3 acidic
solutions
Y. Kitayama,*1 Y. Fukuda,*1 H. Haba,*2 K. Tsukada,*3 A. Toyoshima,*3 H. Kikunaga,*4 M. Murakami,*2, *5 Y. Komori,*2
M. H. Huang,*2 T. Taniguchi,*1 S. Ueno,*1 K. Hayashi,*1 Y. Yatsu,*1 I. Chiyonishio,*6 K. Murakami,*6 and A. Yokoyama*6in the range of [F－]eq > 4 × 10－5 M in both the batch andon-line experiments. This indicates that fluoride
complexation of Zr and Hf consecutively proceeds to form
neutral or anionic species from cationic ones with theincrease in [F－]eq. Therefore, differences in the formation offluoride species between Rf and its homologues can beobserved in these [F－]eq.
As a preliminary result, 160 α events including 21
time-correlated α-particle pairs (8.00-8.40 MeV) from 261Rf
and its daughter nuclide 257No were observed in 1001 cyclesof the chromatography experiment. The %ads values of Rf
were evaluated by using the following equation:

where Fr1 and Fr2 are the radioactivities observed in thefractions 1 and 2, respectively. The %ads values of Rf wereconstant at around 60% in the [F－]eq range up to 5×10－4 M
and then steeply decreased at [F－]eq = 9×10－4 M while
those of Hf decreased significantly from 100% to a few
percent around [F － ]eq = 1×10 － 4 M. The latter data
reproduced the results for Hf for the on-line experiments
shown in Fig. 1. This suggests that the cationic fluoride
complexes of Rf exist more stably than those of Hf at [F－]eq> 1×10－4 M.

-1

102

Kd /mL g

Recently, we developed a reversed-phase-chromatography technique with 2-thenoyltrifluoroacetone (TTA) as achelate extractant to clarify chemical properties of acationic fluoride complex of a superheavy element,
rutherfordium (Rf). The resin containing a TTA n-octanolsoluiton has been prepared for that purpose [1]. In this study,
we have investigated chromatographic behavior of Rf withthis technique in various HF/HNO3 solutions.
Both of batch and on-line experiments were performed
with Zr and Hf to determine experimental conditions
suitable for Rf. For batch experiments, non-carrier tracers ofZr and Hf were used to examine distribution coefficient (Kd)values. As for on-line experiments, reversed-phase
chromatography of the short-lived nuclides 89m, 85Zr and169
Hf was performed with a micro-column in the same way
as Rf experiment to obtain elution curves and percent
adsorption values (%ads) as defined below.
In Rf experiments, nuclides of 261Rf with a half-life of 68s and 169Hf were simultaneously produced in the 248Cm(18O,5n)261Rf and natGd(18O, xn)169Hf reactions, respectively,
with 109.3 MeV 18O beam at the RIKEN K70 AVF
cyclotron. The reaction products were rapidly transportedwith a KCl/He gas-jet system to the chemistry laboratory
and were deposited on the collection site of the on-line
Automated Rapid Chemistry-Apparatus (ARCA) for
chromatography experiments. The products were dissolved
in HF/0.01 M HNO3 solutions and were fed onto themicro-column (1.6 mmφ×7 mm) of ARCA at a flow rate of
0.1 mL/min. The resin containing 25 wt.% of TTA was
filled in the column. The effluent from the column wascollected on a Ta-disk as fraction 1. The remaining productsin the column were then stripped with a 0.1 M HF/0.1 M
HNO3 solution and were collected on another Ta disk as
fraction 2. These disks were then separately evaporated todryness with a halogen heat lamp and heated He gas. The
samples were assayed with a rapid α/SF detection system
for studying the aqueous chemistry of superheavy elements
at RIKEN.
The Kd values of Zr and Hf in the batch and on-line
experiments were determined and compared in the wide
range of F－equilibrium concentration ([F－]eq) as shown in
Fig. 1. The values of both Zr and Hf show sudden decreases

101

100 -7
10

Hf batch
Zr batch
Hf online
Zr online
10-6

10-5
10-4
[F-]eq /M
Fig. 1 Distribution coefficients, Kd, of Zr and Hf plotted asa function of [F－ ]eq assayed by batch (solid lines) andon-line (closed symbols) experiments.

*1

Graduate School of Natural Science and Technology, Kanazawa
University*2
RIKEN Nishina Center*3
Advanced Science Research Center, Japan Atomic Energy Agency*4
Research Center for Electron Photon Science, Tohoku University*5
Graduate School of Science and Technology, Niigata University*6
Institute and College of Science and Engineering, Kanazawa University- 281 -

Reference

1) M. Araki, T. Nanri., Y. Takeda, M. Nishio, M. Nishikawa, Y.
Kasamatsu, Y. Ezaki, Y. Kudou, H. Haba, and A. Yokoyama,:
RIKEN Accel. Prog. Rep. 43, 271 (2010).

Survival
Survival
probability,
probability,% %Survival probability, %Recently, the on-line production of Sg(CO)6 was
1. The difference of 23 kJ/mol in (FBDEs) of Mo-CO
achieved.1) The Sg-CO bond in the Sg(CO)6 complex was(169 kJ/mol) and W-CO (192 kJ/mol) leads to a
predicted to be slightly more stable than the corresponding
decomposition temperature shift of about 100°C. The
bond in the complex of its lighter homolog W(CO)6. 2) In
figure suggests that the experiment can be sensitive to a
Ⅲ-3. Radiochemistry & Nuclear Chemistry
RIKEN Accel. Prog. Rep. 48 (2015)
this work, we aim to design the experimental setup to
Experiment:
verify this prediction. Alpha-decaying isotopes 163W and
Mo(CO)6164
W were producedin fusion-evaporation
reactions
Thermalstability
of
the
group
6
hexacarbonyl
complexes
W(CO)6100
144
Sm(24Mg,xn)163-164W at RIKEN Linear Accelerator
Simulations (FBDE):
Thermalstabilityof the6 hexacarbonyl complexes
was bombarded
withgroupa(RILAC). Therefore,a 144Sm target
Mo(CO)(169 kJ/mol)
80 *4,*5,*6 R. Eichler,*1,*2 J. Even,
*1,*2
*3
*4
*5
*5
*7
I.
Usoltsev,
M.
Asai,
H.
Brand,A.
Di
Nitto,
Ch.E.
Düllmann,
F. 6Fangli,
24energyof
0.66 µApart *8Mg beam, at *4a center-of-target
W(CO)(192 kJ/mol)
6
*8
*4
*8
*8
*8
*5
*4
Hartmann,M.
E. Jäger,D. *5
Kaji, J. Kanaya, *4,*5,*6
Y. Kaneya, J. Khuyagbaatar,
B.(189-205
Kindler,Haba,TheW.Gas-filled*3 Huang,*4*5*7kJ/mol)
136H.
MeV.
Recoil
Separator(GARIS)
Sg(CO)
60
I. Usoltsev,*1,*2
H.Ion
Brand,
Ch.E. Düllmann,
R. Eichler,*1,*2 J. Even,
F. 6Fangli,*6 M. Asai,*4*8 A. Di Nitto,
*4
*4
*3,*9
*8
*8,*10J.V.*8Kratz, separation
J.Krier,*4 Y.
Kudou,
S. Miyashita,
K.*8Morimoto, K. Morita,*8 N. Kurz,*4 B. Lommel,
*8
*8
*5
*4
allowedforefficientthe desired
evaporation
W. Hartmann,
M.ofHuang,
E. Jäger,
B. Kindler,
H. Haba,*8,*11*3*12, *13 D. Kaji,*11J. Kanaya, *3Y. Kaneya, *3J. Khuyagbaatar,*4*1, *2Y.
Nagame,H.
Nitsche,
K.
Ooe,
T.K.
Sato,
M.
Schädel,J.
Steiner,P.
Steinegger,
M.
Murakami,
*6
*4
*8
*4
*4
*3,*9
*8
*8,*10residues J.V.
fromKratz,
the beamand *8from
multinucleon
J.Krier,Y. Kudou,
N. Kurz,transfer
B. Lommel,
S. 40
Miyashita,
K. Morimoto, K. Morita,
*8
*8
*3
*8
*7
M.*8,*11
Takeyama,
K.
Tanaka,A.*12,
Toyoshima,
K. Tsukada,*3*3A. Türler,*1, *2
Y. Wang,
T. Sumita,*3*13a gas*11*3 Y. Wakabayashi,*4*1, *2
products.
The separated
werein
Y.isotopes
Nagame,H.thermalized
Nitsche,
K.
Ooe,
T.K.
Sato,
M.
Schädel,M. Murakami,*3, *6*8, *1, *4*4*7 J. Steiner, P. Steinegger,
N. Wiehl,
S. Yamaki,
A. Yakushev,
Q. Zhi
16320 *3 A. Türler,*8 and He 1:1 by*8*1, *2
mixtureof CO
volume.
M. Takeyama,*8 K.
Tanaka,The
A.formedToyoshima,*3 K. Tsukada,
Y. Wakabayashi,*8 Y. Wang,*7
T. Sumita,
164
*3,
*6
*8,
*1,
*4
*4
*7
W(CO)6 complexes were N.transported
theWiehl,
S.toYamaki,
A. Yakushev, Q. Zhi
Recently, thesetup
on-lineproductionof capillaries.
Sg(CO)6 The
was
1. The0 difference of 23 kJ/mol in (FBDEs) of Mo-CO
decomposition
through
PFA Teflon
1)
The Sg-COin the ofSg(CO)
complex wasachieved.
(169 kJ/mol) and W-CO (192 kJ/mol) leads to a
decomposition
setup bondconsisteda 6decomposition
200 300
500 600
700 800 of900
Recently,
the on-line production of Sg(CO)6 was
1. The100
differenceof 400
23 kJ/molin (FBDEs)
Mo-CO3) to be slightly more stable than the corresponding
predicted
decomposition temperature shift of about 100°C. The
column , covered inside by silver foil, and a bypass
Cachieved.1) The Sg-CO bond in the Sg(CO)6 complex 2)was(169 kJ/mol) and Temperature,
W-CO (192 kJ/mol)
leads to aInbond in ofthethecomplexof itslighter
homologW(CO)figure suggests that the experiment can be sensitive to a6.
columnsame size
madeof PFA
Teflon.
Becauseofpredicted to be slightly more stable than the corresponding
decomposition temperature shift of about 100°C. The
small difference in FBDE i.e., 10 kJ/mol.
this
work,
we
aim
to
designtheexperimental
setup
tothe high inertness toward carbonyl complexes the Teflon
2)Inbond in the complex of its lighter homolog W(CO)figure suggests that the experimentcan be sensitive to a
Experiment:
163 6.
Wandverifythis
prediction.
Alpha-decaying
isotopes
bypass was implemented to quantify the actual production
Mo(CO)
Fig. 1: 104Mo(CO)6 and 163-164W(CO)
thiswork, we aim to design the experimental setup to
6 6 experimental
164
W of
werethe produced
fusion-evaporation
Experiment:yield
carbonyl incomplexes.
The yieldsreactionsof theW(CO)decomposition
curves (symbols)
andsimulatedcurves100
6verifythis prediction.
Alpha-decaying isotopes 163W and
144
24
163-164
Mo(CO)6
Sm( Mg,xn)
W to
at pass
RIKEN
Linear Accelerator
carbonylcomplex able
this decomposition
setup
164
Simulations(FBDE):
considering the relevant FBDE’s(dashedlines).
The
W were produced 144in fusion-evaporation reactions
W(CO)6 (169 kJ/mol)
was bombarded
with a(RILAC).
Therefore,
a Sm
100
Mo(CO)
were
determinedby means
oftargettotal trappingof the volatile144
163-1646
80 interval2) for 265Sg(CO)6 is indicated(redarea).
predicted
Sm(24Mg,xn)
W at RIKEN Linear Accelerator
24
Simulations
a center-of-target
energy of
0.66 µApart inMgthebeam,
W(CO)6(FBDE):(192 kJ/mol)complexes
cryo atonline
thermochromatography(RILAC). Therefore, a 144Sm1)target was bombarded with aMo(CO)6 (169 kJ/mol)
80
WedevelopedaMonte-Carlobased
two-step
reversible
136
MeV.
The
Gas-filled
RecoilIon
Separator(GARIS)
Sg(CO)(189-205
kJ/mol)detector array
COMPACT. The primary result of a60
60.66 µApart 24Mg beam, at a center-of-target energy ofW(CO)6 (192 kJ/mol)
3)adsorption-irreversible
decomposition
model
for
allowedforefficientseparationofthedesiredevaporation
complete decomposition experiment is given in a form of a
136 MeV. The Gas-filled Recoil Ion Separator (GARIS)
Sg(CO)6 (189-205 kJ/mol)
60
describing
theheterogeneous
decomposition
process.
This
residues
from
the
beam
and
from
multinucleon
transfer
40
decomposition curve, which pictures the survival
allowed for efficient separation of the desired evaporation
model successfully reproduced the experimental results for
products. The
isotopes
were thermalized
in a gasprobability
forseparated
a complex
as a functionof decomposition
residues from the beam and from multinucleon transfer
4016320 6 and W(CO)6 (Fig. 1, dashed lines) and could be
Mo(CO)
mixture
of
CO
and
He
1:1
by
volume.
The
formedtemperature. The results of the model experiments withproducts.
The
separatedisotopes
werethermalized
in
a
gas
164
104W(CO)6
252wereused
for designing and evaluating data of the futurecomplexes
transportedtotheMo obtained from the Cf spontaneous fission source20
mixture of CO and He 1:1 by volume. The
formed 1630
3)
decomposition
experiments with Sg(CO)6 (Fig. 1, reddecomposition
setup
through
PFA
Tefloncapillaries.
The“Miss Piggy” at the University of Bern are presented
164
W(CO)6 complexes were transported
tothe163,164
intervalof
FBDE=
kJ/mol).
Thus,
completedecomposition
setup
consistedofadecomposition
W in Fig.
together with the current results obtained for0100 200 300 197±8
400 500
600 700
800a 900
decomposition
setup through PFA Teflon capillaries. The
method for the experimental
verificationoftheprediction
column3), covered inside by silver foil, and a bypass
Temperature, Cdecomposition setup consisted of a decomposition2)
100 200 300 400 500 600 700 800 900
was elaborated.
column3)of the same size made of PFA Teflon. Because of*1
Universityof Bern inside by silver foil, and a bypass, coveredcolumnsmall difference in Temperature,
FBDE i.e., 10 kJ/mol.
C
thePaulhighinertnesstoward carbonyl complexes the Teflon*2
Scherrer
Institute
To conclude, we successfully tested a fast and efficientcolumnofthesame size made of PFA Teflon. Because of*3
bypasswas
implemented
toquantify
theactualproduction
104
163-164
Advanced Science Research Center
Mo(CO)andW(CO)experimental
Fig.
small1:difference
in FBDEi.e.,thermal
10 kJ/mol.
6
6
approachforassessingthestabilityof group 6
theGSI
high inertness toward
carbonyl complexes the Teflon*4
für Schwerionenforschungyield Helmholtzzentrumof the carbonyl
complexes. The yields of thedecomposition
curves(symbols)
andsimulatedcurvescarbonylcomplexes.
The
dissociationenergyofthe Sg-CO*5bypasswas
implemented
toquantify
theactualproduction
104
163-164
Helmholtz-Institut
Mo(CO)6 andW(CO)6 experimental
Fig. 1:
carbonylcomplexMainz
able to pass this decomposition setup*6
consideringtherelevant
FBDE’s(dashedlines).
bond can be therefore experimentally investigated The
and
yield
of Gutenberg-Universität
the carbonyl complexes.
The yields of theJohannes
Mainz
decomposition curves(symbols) and simulated curves
weredetermined
by
means
of
total
trappingofthevolatile
265*7
Sg(CO)(red
predictedcomparedinterval2) for
Institute ofModern Physics
Lanzhou
6 is indicateddirectly
withthe related
properties
ofarea).
lightercarbonylcomplexable topass this decomposition setup
considering the relevant FBDE’s (dashed lines). The
complexes
in forthecryo onlineSciencethermochromatography*8
Nishina
Center
Accelerator-Basedhomologs.
weredeterminedbymeans of1) total
trapping of the volatile*9Wedevelopeda 2)Monte-Carlo
two-step
reversiblefor 265Sg(CO)based(redarea).
predicted
interval
6 is indicatedThe
primary
resultofadetector
array
COMPACT.
Hiroshima University
complexes
in
the
cryo
onlinethermochromatography
3)*10
adsorption-irreversible
decomposition
model
for
Kyushu University
completedecomposition experiment
is
given
in
a
form
of
a
ReferencesWe
developed a Monte-Carlo based two-step reversible*11
detectorarray COMPACT.1) The primary result of a
Niigata University
describing
theheterogeneous
decomposition
process.
This
decomposition
curve,
which
picturesthesurvival
1)
J. Even et al.: Science 345,
6203 (2014). model3)*12
adsorption-irreversible
decomposition
forcompletedecomposition
experiment is given in a form of a
Universityof California
model
successfully
reproduced
the121,experimental
results forprobability
for a complex as a function of decomposition
2)
C.
S.
Nash:
J.
Am.
Chem.
Soc.
10830 (1999).
*13
describing the heterogeneous decomposition
process. This
Lawrence Berkeleycurve,
National Laboratory
decomposition
which pictures the survival
1, dashedlines) and could be
Mo(CO)
6 and W(CO)
6 (Fig.Univ.
temperature.
The results of the model experiments with
*14
3)
I. successfully
Usoltsev:
PHDreproduced
ThesisBern(2014).
Saitama University
model
the
experimental
results forprobability
for a complex as a function of decomposition
104
used for designing and evaluating data of the future
Mo obtained from the 252Cf spontaneous fission source
Mo(CO)6 and W(CO)6 (Fig. 1, dashed lines) and could betemperature. The results of the model experiments
with3)
decomposition experiments with Sg(CO)6 (Fig. 1, red“Miss Piggy” at the Universityof Bern are presented
104
used for designing and evaluating data of the future
Mo obtained from the 252Cf spontaneous 163,164
fission source
interval of FBDE= 197±8 kJ/mol). Thus, a complete
W
in
Fig.
together with the current results obtained fordecomposition experiments with Sg(CO)6 (Fig. 1, red“Miss Piggy” at the University of Bern 3) are presented
method for the experimental verification of the prediction
interval of FBDE= 197±8 kJ/mol). Thus, a complete
together with the current results obtained for 163,164W in Fig.
2)
was elaborated.
*1
University of Bernmethod for the experimental verification of the prediction*2
2)
Paul Scherrer InstituteTo
conclude,
we successfully tested a fast and efficientwaselaborated.
*1*3 University of Bern
Advanced Science Research Center
approachforassessing
the thermal stability of group 6*2*4 Paul Scherrer Institute
GSI Helmholtzzentrum für SchwerionenforschungTo conclude, we successfully tested a fast and efficient*3
carbonylcomplexes.
The
dissociation energy of the Sg-CO*5 Advanced Science Research Center
Helmholtz-Institut Mainz
approach for assessing the thermal stability of group 6*4*6 GSI Helmholtzzentrum für Schwerionenforschung
bond
can
be
therefore
experimentallyinvestigated andJohannes Gutenberg-Universität Mainz
carbonyl complexes. The dissociation energy of the Sg-CO*5*7 Helmholtz-Institut Mainz
Institute of Modern Physics Lanzhou
directlycomparedwiththerelatedpropertiesof lighter*6*8bond can be therefore experimentally investigated andJohannes
Gutenberg-Universität
MainzScience
Nishina Center
for Accelerator-Basedhomologs.
*7*9 Institute of Modern Physics Lanzhou
directly compared with the related properties of lighter
Hiroshima University*8*10 Nishina Center for Accelerator-Based Science
Kyushu University
homologs.
References*9*11
Hiroshima
University
Niigata
University
Kyushu University
Universityof California*11*13 Niigata University
Lawrence Berkeley National Laboratory*12*14 University of California
Saitama University*13
Lawrence Berkeley National Laboratory*14
Saitama University

1)
2)
1)
3)
2)
3)

*10
*12

J. Even et al.: Science 345, 6203 (2014).
C. S. Nash: J. Am. Chem. Soc. 121, 10830 (1999).
J. Even et al.: Science 345, 6203 (2014).
I. Usoltsev: PHD Thesis Univ. Bern (2014).
C. S. Nash: J. Am. Chem. Soc. 121, 10830 (1999).
I. Usoltsev: PHD Thesis Univ. Bern (2014).

References- 282 -

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Extraction behavior of Mo and W from H2SO4 using amine-extractant(Aliquat336) as homologs of seaborgium
A. Toyoshima,*1 A. Mitsukai,*1,*2 A. Vascon,*1 Y. Kaneya,*1,*3 M. Murakami,*4,*5 K. Ooe,*4 N. Goto,*4 D. Sato,*4 Y. Komori,*5
H. Haba,*5 K. Tsukada,*1 M. Asai,*1 T. K. Sato,*1 Y. Nagame,*1 and M. Schädel*1,*6

Advanced Science Research Center, Japan Atomic Energy Agency
Faculty of Science, Ibaraki University＊3
Graduate School of Science and Engineering, Ibaraki University＊4
Graduate School of Science and Technology, Niigata University＊5
RIKEN Nishina Center＊6
GSI Helmholtzzentrum für Schwerionenforschung GmbH
＊1
＊2

volumes of the organic and aqueous phases, respectively.
In the experiments of W, 181W was produced in the181
Ta(d, xn)181W reaction at the RIKEN K70 AVF cyclotron.
After the chemical separation of 181W from a Ta target
material through an ion-exchange, carrier-free 181W wasstocked in H2SO4 solutions. The procedure of thesubsequent batch experiment was the same as that for
93m
Mo described above.
Results of kinetics experiments showed that theextraction equilibrium of 93mMo was reached within 5 s in
the range of 0.1 M < [H2SO4] < 8.6 M, while that of W wasdependent on [H2SO4]; the equilibrium was attained within
40 s at [H2SO4] < 1 M and within 2 min at 1 M < [H2SO4] <8.6 M. In Fig. 1, the D values of Mo and W underequilibrated conditions are shown as a function of [H2SO4].
The D values of Mo and W decrease up to 3 M and 2 M,
respectively, with increasing [H2SO4]. This is probably due
to protonation reactions of hydrolyzed Mo and W species.
On the other hand, when [H2SO4] > 3 M and > 4 M, the Dvalues of W and Mo, respectively, show a sharp increase.
This clearly indicates the formation of anionic sulfate
complexes of Mo and W. Sulfate complexation of Sg under
the present experimental conditions will be clarified in our
future experiments.
102
93mMo

101

D

Recently, we began to study the aqueous chemistry of agroup-6 transactinide element, Sg. At present, we focus on
the formation of anionic sulfate complexes of Mo and W,
which are lighter homologs of Sg, by means ofamine-extraction in H2SO4 as a preparatory experiment for
Sg. Previously, we have found that the group-4transactinide, Rf, has a weaker preference to form a sulfate
complex than its lighter homologs, Zr and Hf.1) This isconsistent with its predicted, larger ionic radius comparedto the measured radii of Zr and Hf; moreover, this is ingood agreement with a theoretical prediction2) that thestability of Rf complexes is lower because of the smaller
ionic contribution to the chemical bond. The investigationof sulfate complex formation of Sg is, therefore, expected toprovide valuable information on its ionic radius andchemical bonding.
This paper reports on the extraction behavior of thecarrier-free radioisotopes 93mMo and 181W from aqueous
H2SO4 solution using an amine extractant, Aliquat336, by abatch method to ensure that the chemical behavior ofmononuclear complexes of these homologs is retained. First,
the extraction kinetics of these radioisotopes in 0.1, 4.3 and
8.6 M H2SO4 with 0.2 M Aliquat336 were studied. Then,
extraction probabilities were investigated as a function of
H2SO4 concentration, [H2SO4].
In the experiments of Mo, 93mMo was produced in thenatZr(, xn) reaction at the RIKEN K70 AVF cyclotron.
Nuclear reaction products transported by a KCl/He gas-jet
at a flow rate of 2.5 L/min were deposited on a small pieceof plastic (Naflon®, ~2 cm × 1.5 cm) for 3 min. KCl
aerosols were produced by sublimation at 640oC. Then, thedeposited products were dissolved win 100 L of 0.1 – 8.6
M H2SO4 solution. The solution was then added to 600 Lof H2SO4 solution with the same concentration in a plastic
vial. Subsequently, 700 L of the toluene solution of
Aliquat336 was added. After shaking with a Vortex mixer
for 360 s, the mixed sample was centrifuged for 30 s. From
both the phases, 500 L solutions were collected separatelyin 2 vials. These 2 samples were then subjected to -ray
spectrometry with a Ge detector. The distribution ratio, D,
was evaluated with the equation, D = (Aorg / Vorg) / (Aaq / Vaq),
where Aorg and Aaq are the radioactivities in organic andaqueous phases, respectively, and Vorg and Vaq are the

181

W

100

10-1

10-2
10-1

100
[H2SO4] / M

101

Fig. 1. Variation of D value of Mo and W as a function of
H2SO4 concentration, [H2SO4].
References

1) Z. J. Li et al.: Radiochim. Acta 100, 157 (2012).
2) V. Pershina et al.: Radiochim. Acta 94, 407 (2006).

- 283 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Solvent extraction of short-lived radioisotopes of Mo and W from oxalic acidsolution with Aliquat 336 for chemical studies of seaborgium (Sg)N. Goto, *1 K. Ooe, *1 A. Toyoshima,* 2 M. Murakami,*1,*3 Y. Komori, *3 H. Haba,*3 S. Goto,*1 and H. Kudo*4

Graduate School of Science and Technology, Niigata University
Advanced Science Research Center, Japan Atomic Energy Agency＊3
RIKEN Nishina Center＊4
Department of Chemistry, Faculty of Science, Niigata University＊1＊2

Dependence of the D values of 93mMo and 177W on the
Aliquat 336 concentration with a 0.01 M oxalic acid/ 0.1 M
HCl/0.9 M LiCl solution is shown in Fig. 1. Results
previously obtained with 181W are also plotted in the same
figure. The D values of Mo and W increase with increasing
concentration of Aliquat 336. The slopes of the D value vs.
[Aliquat 336] plot on logarithmic scales are evaluated to be
2.08 ± 0.03 for Mo and 1.33 ± 0.02 for W with a weighted
least-squares fitting. This indicates that extracted anionic
oxalate complex of Mo is associated with two molecules of
Aliquat 336, while that of W is with one molecule. On amacro scale, it was reported that Mo and W are extracted as(R3NH)2MO2(C2O4)2 from oxalic acid solution, where R3Nshows a trioctylamine (TOA) molecule and M shows Mo or
W.4,5) The present result for Mo corresponds to the reported
Mo oxalate complex. On the other hand, it seems that W
forms a different complex from the Mo one. Under thepresent experimental condition, chloride ions of 1 M arepresent contrary to the experiment in the reference.5)
Therefore, the extracted W complex might contain one
oxalate ion and one chloride ion. To obtain further
information on the extracted species of W, we need toinvestigate the variation in the distribution ratio as afunction of the concentration of chloride ions. Based on theextraction behavior of Mo and W obtained in these studies,
oxalate complex formation of Sg will be investigated.
102
101

Slope: 2.1 (Mo)
Slope: 1.3 (W)100
DThus far, few studies of seaborgium (Sg) in an aqueous
phase have been reported, where only a few events of Sg
weredetected
after
batch-wisecation-exchange
chromatography.1,2) There have been few chemical studies
of Sg owing to the experimental difficulties caused by its
extremely low production yield and short half-life. To
overcome the difficulties, we are developing a new rapid
continuous chemistry apparatus based on the solvent
extraction technique. We have been also studying solvent
extraction behavior and extracted species of molybdenum(Mo) and tungsten (W), which are lighter homologs of Sg,
to apply obtained results to development of the new
apparatus and to compare extraction behavior among thehomologs including Sg. Because it is well-known that Mo
and W form polyoxometalate complexes, Mo and W should
be extracted on a tracer scale for comparison of extraction
behavior of their mononuclear complexes with that of Sg,
which can exist only as single atoms. In a previous report,
the solvent extraction of W from oxalic acid solution into
toluene with Aliquat 336 was carried out with long-lived
radiotracer, 181W (T1/2 = 121.2 d).3) In this paper, we reporton the extraction behavior of Mo using short-lived
radioisotope along with W. The extracted species of these
two elements will be discussed.
Short-lived radiotracers 93mMo (T1/2 = 6.85 h) and 177W
(T1/2 = 2.25 h) were produced in the irradiation with a
50-MeV α beam supplied from the RIKEN K70 AVF
cyclotron on a metallic natZr and natHf target foils. Nuclear
reaction products recoiling out of the targets weretransported by a KCl/He gas-jet method at a He gas flowrate of 2.0 L/min. The transported products were deposited
on a small plastic piece (Naflon®) for 1min. Then, thedeposited products were dissolved with 100 μL of 0.01 M
H2C2O4 (oxalic acid)/0.1 M HCl/0.9 M LiCl solution. The
solution was then pipetted to a plastic tube in which 600 μL
of aqueous solution and 700 μL of Aliquat 336 in toluene
had been added. After shaking with a Vortex mixer for 5min, the mixed sample was centrifuged for 30 s. From boththe phases, 500 μL of aliquots were separately taken into
two vials. These two samples were then subjected to γ-ray
spectrometry with a Ge detector. The distribution ratio (D)of 93mMo and 177W was calculated using the equation of D =(Aorg / Vorg) / (Aaq / Vaq), where Aorg and Aaq are theradioactivities in organic and aqueous phases, respectively,
and Vorg and Vaq are the volumes of organic and aqueous
phases, respectively.

10-1

93m
Mo
181
W
177

10-2
10-3

W

10-5

10-4
10-3
10-2
[Aliquat 336] / M

10-1

Fig. 1. Variation in the distribution ratio of 93mMo, 177W and181
W from 1.0 × 10-2 M oxalic acid with 0.1 M HCl/0.9 M
LiCl as a function of the concentration of Aliquat 336.
References

1) M. Schädel et al.: Radiochim. Acta 77, 149 (1997).
2) M. Schädel et al.: Radiochim. Acta 83, 163 (1998).
3) N. Goto et al.: RIKEN Accel. Prog Rep. 47, 269 (2014).
4) K. Yakabe and S. Minami: Nippon Kagaku Kaishi 1045 (1983).
5) K. Yakabe, K. Iwamoto and S. Minami: Nippon Kagaku Kaishi
714 (1985).

- 284 -

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Reversed-phase chromatography of Nb and Ta with TBP for
conducting a chemical experiment on the 105th element, Db
M. Murakami,∗1,∗2 S. Tsuto,∗1 K. Ooe,∗1 S. Goto,∗1 D. Sato,∗1 N. Goto,∗1 T. Koyama,∗1 T. Nagaoka,∗1
R. Motoyama,∗1 H. Haba,∗2 Y. Komori,∗2 A. Toyoshima,∗3 A. Mitsukai,∗3,∗4 Y. Kitayama,∗5 Y. Fukuda,∗5
and H. Kudo∗1

∗1

∗2
∗3
∗4
∗5

Department of Chemistry, Niigata University
RIKEN Nishina Center
Advanced Science Research Center, Japan Atomic Energy
AgencyFaculty of Science, Ibaraki University
Graduate School of Natural Science and Technology,
Kanazawa University- 285 -

Radioactivity per each fraction (arb. unit)of the total activity of 178a Ta). Similar elution behavior of 90g Nb was also observed at higher [HF]ini . The
peak volume of the elution curves of 178a Ta gradually
decreased, corresponding to the decreasing distribution coefficient (Kd ) of 178a Ta on the TBP resin. In
Fig. 1, the elution curve of 178a Ta was fitted by theGlückauf formula of chromatography4) except for the
first leakage fraction. The Kd values are described as
Kd = vp /mr , where vp and mr are the peak volume andmass of dry resin (6.31 mg), respectively. The evaluated Kd values of 178a Ta are shown in Fig. 2 together
with those of 179 Ta previously obtained by the batch
experiments.1) The good agreement between the online and off-line results indicates that the extraction
equilibrium is reached in the present column experiment. Recently, we performed an extraction experiment of Db with the studied system.5)
100
100
90g
90g
Nb
Nb
178a
178a

80
80

Ta
Ta

60
60
40
40
20
20
00

00

500
500

1000
1000

1500
1500

Volume (µL)(�L)
VolumeFig. 1. Elution curves of 90g Nb and 178a Ta in 1.0 M HF on
the column of 62 wt%TBP resin.
3
10
103
178a
178a
Ta
Ta(on-line)(on-line)
90g
90g
Nb
Nb(batch)(batch)179
179

Ta
Ta(batch)(batch)2
10102

Kd (mL/g)(mL/g)
Kd

Detailed chemical properties of superheavy elements(SHEs) have not been elucidated owing to the difficultyin conducting chemical experiments because of theirshort half-lives and extremely low production rates.
For investigating the chemical properties of the 105th
element, Db, we studied the extraction behavior of
the group-5 homolog elements Nb and Ta from HF
media with tributyl phosphate (TBP), which is usedin the industrial separation of Nb and Ta. In ourprevious study using batchwise solvent extraction,1)
we observed the differences between the 95g Nb and179
Ta extraction behaviors; the distribution ratios of
179
Ta reach a maximum at the initial HF concentration, [HF]ini = 0.27 M, whereas those of 95g Nb increase
with increasing [HF]ini . To examine the applicabilityof this extraction system to the short-lived 262 Db with
T1/2 = 33.8 s, we performed an on-line reversed-phase
chromatographic experiment on Nb and Ta using Automated Rapid Chemistry Apparatus (ARCA).2)
The nuclides 90g Nb (T1/2 = 14.6 h) and 178a Ta(T1/2 = 2.45 h) were produced via the nat Zr(d,xn)
and nat Hf(d,xn) reactions, respectively, with a 24-MeV
deuteron beam supplied from the RIKEN AVF cyclotron. The nuclides produced were transported witha He/KCl gas-jet system and were deposited on a collection site in ARCA for 60 s. Then, the products
were dissolved in 1–10 M HF solutions and were loaded
onto a column (1.6 mm i.d. × 7.0 mm height) filledwith a 62-wt% TBP-laden resin, which was preparedin the procedure described in Ref. 3. The flow rateof the eluent was 1.0 mL/min. The effluent fractions
were consecutively collected in 7 polypropylene (PP)tubes. The remaining products in the column were
stripped with 330 µL of 10 M HF at a flow rate of 1.0
mL/min, and the effluent was collected in another PP
tube. Each fraction was subjected to γ-ray spectrometry with a Ge detector.
Figure 1 shows the elution curves of 90g Nb and178aTa in 1.0 M HF as an example, in which correction for a dead volume of ARCA (40 µL) was made forthe effluent volume. 90g Nb was eluted immediately,
whereas 178a Ta showed a broad peak around 770 µL
with a small leakage in the first effluent (less than 5%

1
10
101

0
10
100
-1
10
10-1

0
10
100

1
10
101

2
10
102

[HF]
[HF]iniini(M)(M)

Fig. 2. Variation in Kd values of 178a Ta as a functionof [HF]ini (closed symbols). The Kd values of 95g Nb
and 179 Ta obtained by the batch experiment1) are also
shown as open symbols.

References

1) S. Tsuto et al.: RIKEN Accel. Prog. Rep. 47, 270
in press.
(2014).
2) Y. Nagame et al.: Radiochim. Acta 93, 519 (2005).
3) H. Haba et al.: Radiochim. Acta 95, 1 (2007).
4) E. Glückauf: Trans. Faraday Soc. 51, 34 (1955).
5) M. Murakami et al.: In this report.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Liquid-liquid extraction of Nb and Ta with Aliquat 336
from 0.27 M HF solution
D. Sato,*1,*2 M. Murakami,*1,*2 K. Ooe,*1 H. Haba,＊2 H. Kikunaga,*3 S. Goto,*1 and H. Kudo*4
The elements with atomic numbers ≥ 104 are called
transactinide elements. Their chemical properties are
greatly interesting because it is expected that chemical
behavior of these elements would deviate from that oflighter homologs by strong relativistic effects on valence
electrons1). Therefore, it is very important to study thechemical behavior of transactinide elements comparing withthat of lighter homologs.
Among the transactinide elements, we are interested in thechemical properties of 105th element Db, especially, forcomplex formation with a fluoride ion which is a strong
complexing reagent for group 5 elements. Anionic fluoride
complex formation of Db has been investigated throughanion exchange study from HF solution2). The result of thisexperiment showed that the Kd value of Db in 13.9 M HF
was smaller than that of Nb and Ta, which are lighter
homologs of Db. However, the chemical form of Db was
not yet determined in this condition. Therefore, forinvestigation of fluoride complex formation of Db in detail,we have been studying the liquid-liquid extraction behaviorof Nb and Ta from HF solutions with quaternary ammonium
salt, Aliquat 336. So far, a clear difference of the extraction
behavior between Nb and Ta in 10-2-27 M HF was observed.
While distribution ratios (D) of Nb were decreased withincreasing HF concentration, those of Ta were a maximum
at around 0.3 M HF3). Since linear relations with slope ≈ 1
for both elements were observed from log D vs. log[Aliquat 336] plots, it was suggested that univalent anionic
fluoride complex of NbOF4- and TaF6- were extracted by
Aliquat 336 in 2.7 M and 10 M HF. However, in previous
study, we have not obtained information of chemical
species in 0.27 M which those of Ta are most extracted.
Therefore, in the present work, variation of D values of95g
Nb and 179Ta vs. concentration of Aliquat 336 in 0.27 M
HF was studied.
Long-lived radiotracers, 95gNb (T1/2 = 34.97 d) and 179Ta(T1/2 = 665 d), were produced during deuteron irradiation ofZr and Hf metallic foil targets with natural isotopic
abundances, respectively, using the RIKEN K70 AVF
Cyclotron. These radiotracers in the targets were chemicallyisolated by ion-exchange separation. The tracers weredissolved in 600 μL of 0.27 M HF and then mixed with thesame volume of 10-8-10-1 M Aliquat 336/1,2-dichloroethane
solutions in a polypropylene tube. After shaking of thesolutions for 5 min, followed by centrifugation, the twophases were separately pipetted into sample tubes. The
Graduate School of Science and Technology, Niigata University
RIKEN Nishina Center*3
Research Center for Electron Photon Science, Tohoku University*4
Department of Chemistry, Faculty of Science, Niigata University*1*2

radioactivities of the two samples were measured with a Ge
detector. D values of Nb and Ta were obtained from theratio of the radioactivities of the two phases.
The dependences of the distribution ratios of 95gNb and179
Ta in 0.27 M HF on the concentrations of Aliquat 336 areshown in Fig. 1. The results show a linear relation with aslope of ≈1 for both Nb ([Aliquat 336] = 10-5-10-1 M) andTa ([Aliquat 336] = 10-8-10-7 M), which indicates that
univalent anionic fluoride complexes are extracted by
Aliquat 336. Therefore, it is suggested that NbOF4- andTaF6- were also extracted by Aliquat 336 in 0.27 M HF
along with 2.7M and 10 M HF.

Fig. 1: Variation of the distribution ratio D of 95gNb and179
Ta vs. concentration of Aliquat 336 in 0.27 M HF.
From the obtained results and reference [4-5], it isassumed that the chemical species of Nb and Ta change
from NbOF4- to NbOF52- and from TaF6- to TaF72-,
respectively, with increasing HF concentration in the rangeof 0.27-10 M, expressed as following equations:NbOF4- + F- ↔ NbOF52-(1)

TaF6- + F- ↔ TaF72-(2)

In the near future, dependence of D values of 95gNb and
Ta on concentration of Aliquat 336 in HF solution lower
than 0.27 M will be investigated for further study offluoride complex formation of group 5 elements.

179

References

1) P. Pyykko: Chem. Rev. 88, 563 (1988)
2) K. Tsukada et al.:,Radiochim. Acta 97, 83 (2009).
3) D. Sato et al.: Accel. Prog. Rep. 47 271 (2014).
4) F. Monroy Guzman et al.: J. Radioanal. Nucl. Chem. 208, 461(1996).
5) A. Agulyansky: The Chemistry of Tantalum and Niobium
Fluoride Compounds, 125-134- 286 -

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Coprecipitation Behaviors of Zr, Hf, and Th with Sm Hydroxide
for Chemical Study of Element 104, Rf†
Y. Kasamatsu,＊1 K. Toyomura,＊1 N. Shiohara,＊1 T. Yokokita,＊1 Y. Komori,＊1,＊2 A. Kino,＊1 T. Yoshimura,＊3 N. Takahashi,＊1
H. Haba,＊2 Y. Kudou,＊2 H. Kikunaga,＊2,＊4 T. Mitsugashira,＊5 T. Ohtsuki,＊6 K. Takamiya,＊6 and A. Shinohara＊1
Owning to significant relativistic effects on electron
orbital shells for heavy elements, the chemical properties ofthe superheavy elements are expected to deviate from thecharacteristic periodicity of the lighter homologues in the
periodic table, and their chemical studies have attracted
much attention. However, experimental evaluation of these
species is fraught with difficulties. Because of theextremely low production rates and short half-lives (withina few min) of these heavy nuclides, chemical evaluations of
the superheavy elements must be rapidly conducted on a
one-atom-at-a-time basis. Thus, simple chemistry
employing partition methods such as solvent extraction andion-exchange chromatography have been utilized and thechemical separations were repeated hundreds or thousandsof times under identical conditions. This approach requires
a rapid chemistry apparatus. Additionally, for unambiguous
identification of superheavy nuclides, it is necessary tomeasure the energies and lifetimes of α or sometimes
spontaneous fission decays.
The purpose of the present study is to establish a newexperimental methodology for investigating the chemical
properties of superheavy elements, specifically, thecoprecipitation properties of 261Rf (T1/2 = 68 s) by theformation of hydroxide and ammine complexes. Herein, weapplied a simple coprecipitation method with Sm hydroxide,
which facilitates α spectrometry with high energy
resolution,1) to the investigation of the coprecipitation
behaviors of the homologues of Rf: Zr, Hf, and Th. In
addition, a semiautomatic apparatus for repetitive
preparation of precipitate samples was developed and tested
using the gas-jet transport system of nuclear products.
We used 88Zr, 175Hf, and 228Th radiotracers to prepare
coprecipitated samples with Sm hydroxide. A 20 μL aliquotof the Sm standard solution (Sm 1000 ppm, 1 M HNO3)
was added into 220 μL of an aqueous solution (~0.4 M HCl)containing the radiotracers in a polypropylene (PP) beaker.
The solution was stirred and 2 mL of the basic solution(dilute and concentrated aqueous NH3 and 0.1, 1.0, 6.0, and12.0 M NaOH solutions) was then added to produce theprecipitate. After aging the precipitate for 10 s or 10 min at
25 ºC, the precipitate sample was subjected to suction
filtration with a PP membrane filter (eichrom, Resolve®
†

Condensed from the article in J. Nucl. Radiochem. Sci. 14, 7 (2014).
Graduate School of Science, Osaka University＊2
RIKEN Nishina Center＊3
Radioisotope Research Center, Osaka University＊4
Research Center for Electron Photon Science, Tohoku University＊5
Institute for Material Research, Tohoku University＊6
Research Reactor Institute, Kyoto University＊1

Filters 0.1 μm). The obtained sample was dried on a heaterat 100 ºC, and was subjected to γ-ray and α-particle
measurements. The radioactivities of the filtrate and PP
beakers used were also measured. We determined
precipitation yields, Y, and the percent adsorption on the PP
beaker, Rad, from the radioactivities.
A computer-controlled suction filtration apparatus for the
preparation of precipitated samples of heavy elements wasdeveloped. The online experiment using the apparatus was
performed with relatively short-lived nuclides 89m,gZr (4.2
min and 78.4 h) and 173Hf (23.6 h) produced using the AVF
cyclotron at RCNP. These nuclides were rapidly andcontinuously transported from the nuclear reaction chamberto the chemistry laboratory using the He/KCl gas-jet system.
Using the apparatus, the products were dissolved by 200 μL
of dilute HCl and the precipitate samples were prepared atroom temperature in a manner similar to that used in theabove tracer experiment with stirring for 10 s.
The Rad values of Zr, Hf, and Th for samples aged for 10s was generally less than 3%, which suggests that physicaladsorption of these group 4 elements during coprecipitation
with Sm hydroxide was small enough to be negligible in thedetermination of the coprecipitation yields. The Y values ofZr, Hf, and Th obtained with 10-min and 10-s aging are ingood agreement with each other. This suggests that thechemical reactions during coprecipitation of these elements
are fast, and the present conditions are suitable for
evaluating the coprecipitation behavior of 68-s 261Rf.
Almost complete coprecipitation of Zr and Hf with Smhydroxide was achieved when aqueous NH3 solutions and
0.1 M NaOH were used. These results are consistent withthe well-known properties of these elements, i.e., hydroxide
precipitation in basic solutions. With the use of more highly
concentrated NaOH solutions, these yields decreased,
whereas the Th yields were constant at ca. 100%. This is
attributed to the fact that Zr and Hf form hydroxide
complex ions in high [OH−] solutions.
The Y values obtained in the online experiments and theirdependence on the composition of the added basic solution
are consistent with those in offline experiment. Thissuggests that the present experimental method using theapparatus under the present conditions should be applicableto the coprecipitation experiment of Rf.
Reference

1) H. Kikunaga et al., Appl. Radiat. Isot. 67, 539 (2008).

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Liquid-liquid extraction of zirconium and hafnium with
2-thenoyltrifluoroacetone for chemical studies of element 104, rutherfordium
A. Tanaka,*1 K. Ooe,*1 H. Kikunaga,*2 M. Murakami,*1,*3 Y. Komori,*3 H. Haba,*3 S. Goto,*1 and H. Kudo*4

D = Ao/Aa ,Institute of Science and Technology, Niigata University
Research Center for Electron Photon Science, Tohoku University＊3
RIKEN Nishina Center＊4
Faculty of Science, Niigata University
＊2

103

(1)

where Aa and Ao denote the radioactivities of either of 88Zr
and 175Hf in aqueous and organic phases, respectively.
Figure 1 shows the dependence of D values of 88Zr and175
Hf from 3 M HNO3 on the TTA concentration in toluene.
The D value of 88Zr was approximately 10 times that of175
Hf. It is well-known that the chemical behavior of Zr isremarkably similar to that of Hf and mutual separation
between these two elements is very difficult. Therefore, thepresent result shows that TTA has extraction selectivity forZr, and it is very interesting to investigate extraction＊1

behavior of Rf with TTA.
In the extraction of tetravalent metal ions (M4+) with TTA,
the extraction reaction is usually described by the following
equation:
M(TTA)4(o) + 4H+ . (2)M4+ + 4HTTA(o)From eq. (2), it is expected that the log D vs. log [TTA] plotshows linear relation with the slope of 4 and the value of theslope indicates the number of TTA molecules involved in
the extraction reaction. A least-squares fit to the present data
showed a straight line with a slope of 3.8 for 88Zr and 3.9
for 175Hf. Therefore, this result suggests that the main
extracted species of Zr and Hf would be Zr(TTA) 4 andHf(TTA)4 from 3 M HNO3. The slope value of the log D vs.
log [TTA] plot was closer to 3 for both Zr and Hf, in not
greater than 2 M HNO3. This might be caused by the effectof hydrolysis of Zr and Hf: formation of ZrOH3+ andHfOH3+. Thus, an experimental condition suitable forextraction of Rf(TTA)4 is determined to be 3 M HNO3
solution.
In the future, liquid-liquid extraction experiments of Zr
and Hf with a rapid extraction apparatus using flow
injection analysis (FIA) technique3) will be performed for
the Rf experiment.

Distribution ratio

Chemical studies of element 104, rutherfordium (Rf), in
aqueous solutions have been carried out mainly usingIn
thesecolumncolumnchromatography.1),2)
chromatographic experiments, inorganic ligands such as
fluoride and chloride ions were used, and inorganic
complex formation of Rf was investigated. However, little
has been reported regarding the complex formation of Rf
with organic ligands such as a chelating agent. In thepresent study, liquid-liquid extraction of zirconium (Zr) andhafnium (Hf), which are lighter homologs of Rf, wasperformed to find suitable experimental conditions forcomplexation studies of Rf with organic ligands.
2-thenoyltrifluoroacetone (TTA), which is often used as achelate extractant in analytical chemistry and separation
techniques, was applied in this experiment.
Radiotracers of 88Zr (T1/2 = 83.4 d) and 175Hf (T1/2 = 70 d)
were produced in the 89Y(d, 3n) and 175Lu(d, 2n) reactions,
respectively, using the RIKEN K70 AVF cyclotron. Metal
foils of Y (150 µm thickness) and Lu (100 µm thickness)were used as targets. Incident energy of the deuteron beam
was 24 MeV. The produced radiotracers were chemicallyseparated from the target materials through the anion
exchange method and stored in 3 M HNO3 solution.
Aqueous solution of 3 M HNO3 (600 µL) containing 88Zr
and 175Hf radiotracers was mixed with an equal volume of
TTA in toluene solution in a polypropylene tube, and the
mixture was mechanically shaken for 15 hours at 25 ºC.
After equilibration, the mixture was centrifuged for 30
seconds, and a 420 µL aliquot from each phase wasseparately transferred into a polypropylene tube. The
radioactivity of each phase was measured by a Ge detector,
and the distribution ratio (D) was calculated by thefollowing equation:

102
101

88Zr

175Hf

Slope = 3.8

100
10-1
Slope = 3.9

10-2
10-3 -3
10

10-2[TTA] / M

10-1

100

Fig. 1. Dependence of distribution ratios of 88Zr and 175Hffrom 3 M HNO3 on TTA concentration in toluene.
References

1) H. Haba et al.: J. Nucl. Radiochem. Sci. 3, 143 (2002).
2) H. Haba et al.: J. Am. Chem. Soc. 126, 5219 (2004).
3) T. Koyama et al.: 5th Asia-Pacific Symposium onRadiochemistry’13 (APSORC 13), “Development of a rapid
solvent extraction technique with flow injection analysis forsuperheavy element chemistry” 25-NCP-05.

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RIKEN Accel. Prog. Rep. 48 (2015)

Production of platinum radiotracer for Gamma-Ray Emission Imaging
S. Komoto,*1 M. Munekane,*1 T. Fukuchi,*2 H. Haba,*3 K. Higashikawa,*1 M. Ueda,*1 S. Motomura,*2 and S. Enomoto*1,*2
Platinum drugs such as cis-diammine dichloro
platinum(Ⅱ) (cisplatin) have been used for a long time as afirst-choice drug for several types of tumors. The efficacyof these types of drugs has been certainly approved
however the disadvantages are the strong toxic side effects
including nephrotoxicity, nausea, and neurotoxicity. Theseside effects are considered as dose-limitation factors.
Further, in treatment, the tumor gradually develops
resistance to these drugs. There are some mechanisms ofresistance such as “Decreased uptake” and “Increased
efflux.” 1)
To investigate potential side effects and drug efficacy, weare developing noninvasive and quantitative distribution
analysis methods that can determine the concentration ofplatinum drugs in normal tissues/organs and tumors. We
have propose using a new nuclear medicine imaging
technology called GREI (Gamma-Ray Emission Imaging),
to visualize the distribution of platinum drugs labeled withplatinum radionuclides. GREI comprises a Compton camera
composed of two planar germanium (Ge) detectors
developed in our laboratory.2) GREI has a wide detectableenergy range (200-2000 keV) which is different from theconventional imaging modalities, namely single photon
emission computed tomography (SPECT) and positronemission tomography (PET). Next, a variety of nuclides thatwere difficult to image can now be used because of GREI.
For the GREI experiment, platinum radionuclides with
optimum half-lives and emitting γ-rays are required. Someuseful radionuclides for the GREI are listed in Table 1. In
this study, we investigated the production of radio-platinum
nuclides that are suitable for GREI experiments via thenatOs(α,xn) reactions.
For the radio-platinum production, we used metallic natOs
powder (chemical purity: 99.99 %) as the target material.
Approximately 500 mg of osmium powder was pressed by
3 t at 1 min, and molded into a pellet (φ 15 mm). The pellet
was covered with a 10-μm Al foil (chemical purity:
99.999%). The osmium target was irradiated by the 30-MeV
α-beam supplied by RIKEN AVF cyclotron for 1.5 h. The
beam intensity was 1 particle μA. The γ-ray spectrum of theirradiated target is shown in Fig. 1. This spectrum showsthat 189Pt and 191Pt were produced, and fewer quantities ofother impurities such as radio-osmium and radio-iridium
were produced. After the irradiation, the following
separation steps were performed to remove the target
osmium from the radio-platinum as reported by M. Bonardi,
et al.3) First, for removing osmium, the irradiated target wasdissolved in 10 mL conc. HNO3 and heated at the 200 ℃.
Graduate school of Medicine, Dentistry, and Pharmaceutical Sciences,
Okayama University*2
RIKEN Center for Life Science Technologies*3
RIKEN Nishina Center*1

In this step, osmium was distilled and trapped in 4.7 N
NaOH. After almost all of the liquid was evaporated,
another 10 mL of conc. HNO3 was added and heated until
dryness was achieved. After this step, the process of adding
5 mL of conc. HCl and drying up was repeated thrice. The
reaction vessel was washed with 5 mL of 3 M HCl and thesolution containing radio-platinum was transferred to a vial.
After the chemical separation, the radioactivities of 189Pt
and 191Pt were 0.48 and 1.0 MBq, respectively, and thechemical yield was over 90 %.
GREI can detect γ-rays of various energies that are
emitted from 189Pt and 191Pt. This allows us to use both ofthese radio-platinum as radio tracers for imaging. In future,
we will synthesize cisplatin with radio-platinum, administerit to a tumor-bearing mouse, and perform imaging
experiments.
Table. 1. Useful platinum radionuclides for GREI.

Fig. 1. Gamma-ray spectrum of produced nuclides in
irradiated target.
References

1) S. Motomura et al.: J. Anal. At. Spectrom. 28 (6), 934 (2013).
2) M. Kartalou et al.: Mutat. Res.-Fund. Mol. M. 478.1, 23 (2001).
3) M. Bonardi et al.: J. Radioanal. Nucl. Chem. 236.1-2, 159,
(1998).

- 289 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Production of 88Y for gamma-ray emission imaging
K. Higashikawa,＊1,＊2 A. Morioka,＊1 H. Haba,＊3 M. Ueda,＊1 T. Fukuchi,＊4 and S. Enomoto＊1,＊4
Radioimmunotherapy (RIT) is an internal radiation
therapy that uses radiolabeled drugs, in particularparticularly in monoclonal antibodies (mAbs) or peptides.
90
Y emits highly cytotoxic β- ray and is thus a promisingradionuclide for use in RIT. However, 90Y cannot be readily
imaged by nuclear medicine imaging modalities, because
90
Y is a pure β- emitter.1) On the other hand, 86Y emits β+rays, which can be detected by PET.1-3) In addition,
86
Y-labeled drugs (mAbs or peptides) display identicalbiodistributions to 90Y-labeled drugs because 86Y ischemically identical to 90Y.1) Therefore, in recent years, 86Y
has attracted attention as an attractive surrogate for studying
90
Y-labeled drugs. However, the physical half-life of 86Y(T1/2 = 14.7 h) is shorter compared to that of 90Y (T1/2 = 64.1h), and thus, it is not suitable as a surrogate for investigating
serial biodistribution of RIT drugs with long biologicalhalf-lives, such as mAb, which remain circulating in vivo
for weeks.4) A chemically identical surrogate with a longer
half-life is desirable for development phases of 90Y-labeled
drugs.
88
Y is chemically identical to 90Y and has a long half-lifeof T1/2 = 106.6 d. Moreover, 88Y emits γ rays with energies
of 898 and 1836 keV, which can be detected using
semiconductor Compton cameras through gamma-ray
emission imaging (GREI).5) Therefore, the imaging of
88
Y-labeled drugs with GREI has the potential ability toinvestigate the serial biodistribution of 90Y-labeled drugs
with a long biological half-life, in particular, in preclinicalstudies. The final purpose of our study is to develop an
imaging method for 88Y-labeled drugs through GREI. In thisstudy, we produced 88Y for the GREI experiment.
88
Y was produced by the natSr(d,x)88Y reactions. To
prepare a natSrO pellet target with a diameter of 10 mm,
approximately 400 mg of natSrCO3 (Wako Pure Chemical
Industries, Ltd., chemical purity: 99.99%) was heated for 2
h at 1000C and pressed at 1.6 t. The pellet was covered
with a 10-μm Al foil (chemical purity: 99.999%). The target
was irradiated with a 24-MeV deuteron beam supplied fromthe RIKEN AVF cyclotron. The irradiation was performedfor 5 h at a beam current of approximately 1.5 particle μA.
Thirty-nine days after the irradiations, 88Y waschemically isolated from the natSrO target by extraction
chromatography using Ln-resin (Eichrom Technologies,
Inc., particle size: 50-100 μm) filled in a Muromac column(Muromachi Technos Co., Ltd., internal diameter: 5 mm,height: 50 mm). The Ln-resin column was washed in
*1

*2
*3
*4

advance with 3 mL of water, 10 mL of 10 M HNO3, andthen 4 mL of water, and was pre-equilibrated with 2 mL of
1 M HNO3. The irradiated natSrO target was dissolved in 1
M HCl and evaporated to dryness on a hot plate and under aheat lamp. The residue was dissolved in 5 mL of 1 M HNO3,
and was evaporated to dryness. Subsequently, the residue
was dissolved in 5 mL of water and 2 mL of 1 M HNO3,
and was evaporated to dryness. Then, the residue wasdissolved in 2 mL of 1 M HNO3 and loaded onto the
Ln-resin column. The resin was then washed with 16 mL of
1 M HNO3. 88Y was eluted from the resin with 10 mL of 10
M HNO3. The eluted solution was heated to dryness, and 2
M HCl was added to the residue.
The γ-ray spectrum of the final purified product is shownin Fig. 1. Approximately 10 MBq of 88Y was obtained. The
radiochemical yield of 88Y in the chemical isolation process
was approximately 80%. In the next experiment, we plan tosynthesize 88Y-labeled drugs and try to visualize theirbiodistirbution using GREI.

Fig. 1. Gamma-ray spectrum of 88Y after the chemical
isolation.
References

1) T. K. Nayak et al.: Med. Chem. 7(5), 380 (2011).
2) S. Palm et al.: J. Nucl. Med. 44(7), 1148 (2003).
3) T. K. Nayak et al.: Eur. J. Nucl. Med. Mol. Imaging. 37, 1368
(2010).
4) D. R. Mould et al.: Curr. Opin. Drug Discov. Devel. 10(1), 84(2007).
5) S. Motomura et al.: J. Anal. At. Spectrom. 23, 1089 (2008).

Department of Pharmaceutical Analytical Chemistry, Graduate schoolof Medicine, Dentistry, and Pharmaceutical Sciences, Okayama
University
Japan Society for the Promotion of Science
RIKEN Nishina Center
Next-Generation Imaging Team, RIKEN- 290 -

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

99Ru Mössbauer spectroscopy of Na-ion butteries of Na2RuO3 (I)Y. Kobayashi,＊1,＊2 M. Okubo,＊3 H. Haba,＊1 and A. Yamada＊3

Sodium-ion batteries have attracted considerable
attention recently, because of their potential forlarge-scale applications: higher power and less expensive
batteries compared to Li-ion batteries can be realized byutilizing abundant and polarizable sodium ion as amobile charge carrier. One of the main obstacles torealizing high performance sodium-ion batteries is thelow specific capacity of the electrode materials. Thus, it
is particularly important to develop novel Na-ion cathodematerials with a high capacity as well as a high operating
potential.
Our group has recently reported the electrochemical
properties of Na excess transition metal oxide
Na[Na1/3Ru2/3]O2, where the cation arrangement in the[Na1/3Ru2/3] layer is controlled between the ordered anddisordered states by synthetic conditions. Importantly,
the ordered and disordered Na[Na1/3Ru2/3]O2 exhibit
significant differences in the electrochemical properties1).
In this work, we conducted Ru Mössbauer spectroscopy
for the ordered and disordered Na[Na1/3Ru2/3]O2 toclarify the valence states of Ru ions during
desodiation/sodiation.
The source nuclide, 99Rh (T1/2=15.0 d) for 99Ru
Mössbauer spectroscopy was produced via the 99Ru (p,n)
99
Rh reaction. The 96%-enriched 99Ru metal powder was
irradiated by protons with E = 12 MeV and I = 10 µA at
the AVF Cyclotron. The 99Ru metal powder was packed
into an Al holder, which was tightly fixed to theirradiation equipment for cooling by He gas flow andwater flow during the irradiation. After irradiation forabout 24 hours, the target was used as a 99Rh Mössbauer
source without being subjected to annealing or chemicaltreatment2).
99
Ru absorption Mössbauer spectra of Na[Na1/3Ru2/3]O2
samples were obtained using a conventional Mössbauer
spectrometer. Owing to the relatively high energy of the
Mössbauer -ray (89.8 keV), both the source and theabsorbers were maintained at liquid-helium temperature
in a cryostat.
The obtained spectra are shown in Fig. 1 and 2. The
Mössbauer spectrum for the disordered Na[Na1/3Ru2/3]O2(Fig. 1 (a)) shows a broad singlet with isomer shift () ofെ0.30 mm/s and linewidth () of 0.95 mm/s. The  value
is typical of RuIV, although the large linewidth suggests
structural disorder around Ru. The Mössbauer spectrum
for the ordered Na[Na1/3Ru2/3]O2 (Fig. 1 (b)) shows asinglet with  = െ0.27 mm/s and  = 0.63 mm/s,
indicating RuIV. Thus, regardless of the synthetic
＊1
＊2
＊3

RIKEN Nishina Center
University of Electro-Commun.
University of Tokyo

conditions, the valence states of Ru in both compounds
are the same. However, the linewidth for the ordered
compound is much smaller than that of the disorderedone, most likely due to the ordered honeycomb
arrangement of Na and Ru in the [Na1/3Ru2/3] layer.
On charging the ordered compound, the Mössbauer
spectrum, as shown in Fig.2, cannot determine theelectronic structure accurately, in part due to the small
amounts of the obtained sample. However, a preliminary
result indicates oxidation of Ru from tetravalent topentavalent, from the obtained  value of +0.21 mm/s
with a small quadrupole splitting of 0.60 mm/s. Further
experiments with a larger amount of samples are now inprogress to reveal the reaction mechanism of
Na[Na1/3Ru2/3]O2.

(b)

(a)

Fig. 1. 99Ru Mössbauer spectra of (a) disorderedand (b) ordered Na[Na1/3Ru2/3]O2 at 4.2 K.

Fig. 2. 99Ru Mössbauer spectra at 4.2 K of theordered Na[Na1/3Ru2/3]O2 after electric charge.
References

1) M. Tamaru, et al., Electrochem. Commun. 33, 23 (2013).
2) Y. Kobayashi et al., J. Phys. 217, 012023 (2010).

- 291 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Production of 262,263 Db in the 248 Cm(19 F,xn)267−x Db reactionsat Elab = 96 MeV
M. Murakami,∗1,∗2 S. Goto,∗1 K. Ooe,∗1 D. Sato,∗1 S. Tsuto,∗1 N. Goto,∗1 T. Koyama,∗1 R. Aono,∗1 H. Haba,∗2
M. Huang,∗2 and H. Kudo∗1∗1∗2

Department of Chemistry, Niigata University
RIKEN Nishina Center- 292 -

the daughter nuclide, T1/2 = 4.5+1.7−1.0 s, is in agreement with the reported half-life of 258 Lr, T1/2 = 3.9s.3) Thus, these events are attributed to the α deα
αcay chain 262 Db → 258 Lr →. The expected numberof random correlations was evaluated to be 0.3 in thisenergy region. Regarding all 14 events as true ones,
the production cross section of 262 Db is derived as σ
= 0.25+0.08−0.07 nb. This cross section is consistent withthe previously reported one, σ = 0.23+0.18−0.11 nb at 97.4
MeV.1)
Only one α-α correlation was found around the energy regions of 263 Db and its α-decay daughter 259 Lr,
as shown by an arrow in Fig. 1(a). Although this number of the event, one, is comparable with the expected
number of random events, the deduced half-life of thedaughter nucleus, T1/2 = 3.1+14.8−1.4 s, is consistent withthe reported half-life of 259 Lr (T1/2 = 6.2 s3) ). If thisevent is regarded as a true one, the cross section of263
Db is deduced to be σ = 0.031+0.072−0.026 nb, which isone order of magnitude smaller than that of 262 Db as
well as the HIVAP predictions.1)

Daughter energy
energy (MeV)(MeV)
Daughter

9.0
9.0

(a)
(a)

263
263

262
262

Db
Db

Db
Db

(c)
(c)

8.8
8.8
258
258

Lr
Lr

8.6
8.6
8.4
8.4

259
259

Lr
Lr

8.2
8.2
8.0
8.0

20
20

20
20
Counts // 20
20 keVkeVCounts

The isotope 262 Db (T1/2 = 33.8 s1) ) is often usedin the chemical studies of element 105, Db. At
RIKEN, the decay properties of 262 Db produced in
the 248 Cm(19 F,5n)262 Db reaction were recently studied with a gas-jet transport system coupled to the gasfilled recoil ion separator GARIS.1) In this study, however, 263 Db produced in the 4n channel was not observed at 97.4 MeV and 103.1 MeV. The upper-limit
cross sections of 263 Db were rather smaller than thosepredicted by the HIVAP code, which reproduced the
5n channel fairly well. Therefore, in this work, we investigated the production of Db isotopes at a lower
energy of 96 MeV, at which the predicted excitation
function for 263 Db exhibits the maximum.
A 248 Cm2 O3 target of 460 µg/cm2 thickness was prepared by electrodeposition onto a Be backing foil of
1.8-mg/cm2 thickness. nat Gd2 O3 of 23-µg/cm2 thickness was admixed with the target material to simultaneously produce 170 Ta (T1/2 = 6.76 min) via thenat
Gd(19 F,xn)170 Ta reaction. A 19 F7+ beam was supplied by the AVF cyclotron. The beam energy at the
middle of the target was 96.2 MeV, and the energy
degradation in the target was estimated to be 1.0 MeV.
The average beam intensity was 450 pnA.
The reaction products recoiling out of the target were continuously transported by a He/KCl gasjet system to the rotating wheel detection system
MANON. The transport efficiency was estimated to be
74%. Other details of the measurement were similar
to those in our previous study.2)
We searched for time-correlated α-α event pairs at
the α-energy range of 8.0 ≤ Eα ≤ 9.0 MeV. On setting the time window to 25 s, 16 α-α correlations were
found. Figure 1(a) shows the two-dimensional arraysof these α-α correlations. In Fig. 1(a), 74 α-α corα
relations assigned to the decay chain 262 Db → 258 Lr
α
1)→ in the previous experiment are compared. The
α-particle spectra of the parent and daughter nuclides
are shown in Figs. 1(b) and (c), respectively. For theparent α spectrum, the 8.46-MeV α line of 262 Db isseen, while the 8.68-MeV α line was not very clear owing to the low counting statistics. On the other hand,the α lines of 258 Lr were clearly found in the daughter
α spectrum.
In Fig. 1(a), a solid box indicates the gated α-energy
range of the parent 262 Db (8.26–8.83 MeV) and thedaughter 258 Lr (8.36–8.80 MeV). Fourteen events arefound in this energy region. The deduced half-life of

(b)
(b)

This
This work
work
Haba
Haba etet al.
al. (2014)(2014)

10
10

0
0

10
00
10
CountsCounts // 20
20 keV
keV

8
8

8.2
8.2

8.4
8.4

8.6
8.6

8.8
8.8

99

ParentParent energy
energy (MeV)(MeV)

Fig. 1. (a) Two-dimensional representation of timecorrelated events. (b) α spectrum of parent nuclei. (c)α spectrum of daughter nuclei.

References
1) H. Haba et al.: Phys. Rev. C 89, 024618 (2014).
2) M. Murakami et al.: RIKEN Accel. Prog. Rep. 47, 265
inpress.
(2014)
3) R. B. Firestone and V. S. Shirley: Table of Isotopes, 8thed. (John Wiley & Sons, 1996).

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Production of 174Re in the natGd(23Na,xn) reactions for future studies on Bhchemistry using GARIS
H. Haba,＊1 R. Aono,＊2 D. Kaji,＊1 Y. Kasamatsu,＊3 H. Kikunaga,＊4 Y. Komori,＊1 H. Kudo,＊2 K. Morimoto,＊1 K. Morita,＊1
M. Murakami,＊1 K. Nishio,＊5 A. Shinohara,＊3 M. Takeyama,＊1 T. Tanaka,＊1 S. Tsuto,＊2 Y. Wakabayashi,＊1 S. Yamaki,＊1
and T. Yokokita＊3

RIKEN Nishina Center
Department of Chemistry, Niigata University＊3
Graduate School of Science, Osaka University＊4
Research Center for Electron Photon Science, Tohoku University＊5
Advanced Science Research Center, JAEA
＊1
＊2

the least-squares fitting with the Gaussian curve with amaximum yield at Bρ = 1.74 ± 0.01 Tm and a resolution of
ΔBρ/Bρ = 10.0 ± 0.4%. This optimum Bρ agrees well withthat (Bρ = 1.78 ± 0.05 Tm) deduced from our systematic
trend for the low-energy recoil ions.6) The gas-jet transport
efficiency was about 80%. The radioactivity of 174Re
available at the chemistry laboratory is 55 ± 2 kBq pμA–1
after the 60-s aerosol collection. This yield is high enoughto allow development of chemistry apparatuses andinvestigation of chemical systems for the study of Bhchemistry in the future.
105

4

Net counts per min

10

3

10

104

2

0

0

10

349.5 174Re
351.2 176Re
373.6 173Re

Time / min1520

174.8 173W
190.7 173Re

102
101

5

457.7 173W

10423.3 172W

240.2 176Re
243.4 174Re

1

10

253.9 172Re

103

181.5 173Re
184.5 175Re
196.9 177Re

10

109.1 176Re
113.0 174Re
123.2 172Re
130.2 173W

Counts per 0.5 keV

0

100

200

300

400

500

Energy / keV

Fig. 1. Typical γ-ray spectrum observed
nat
Gd(23Na,xn) reactions at Bρ = 1.74 Tm.

in

the

Yield of 174 Re (arb. unit)

We have been developing a gas-jet transport system
coupled to GARIS as a novel technique for superheavy
element (SHE) chemistry.1) So far, isotopes of 261Rf (atomic
number Z = 104), 262Db (Z = 105), and 265Sg (Z = 106) havebeen produced in the 248Cm(18O,5n), 248Cm(19F,5n), and248
Cm(22Ne,5n) reactions, respectively, and the production
and decay properties of these isotopes have been
investigated for chemical studies.1–3) Recently, the chemical
synthesis and gas-chromatographic analysis of Sg(CO)6
were successfully conducted with 265Sg.4) We plan to obtaina heavier element, Bh (Z = 107), by investigatingproduction conditions of 266,267Bh in the 248Cm(23Na,xn)
reactions. In this work, as the first step, we optimized
setting parameters of the GARIS gas-jet system using 174Re
produced in the natGd(23Na,xn) reactions. Since Re is ahomologous element of Bh in the periodic table, the Re
isotopes would be useful in fundamental experiments on Bhchemistry in the future.
The natGd2O3 target with a thickness of 340 μg cm–2 was
prepared by electrodeposition onto a 2-μm Ti foil. The
23
Na7+ ion beam was extracted from RILAC. The beamenergy was 130.6 MeV at the middle of the target, and thetypical beam intensity was 1.4 particle μA. The evaporation
residues (ERs) were separated by GARIS. Several magnetic
rigidities were investigated (Bρ = 1.58–1.94 Tm) at a He
pressure of 33 Pa. Then, the ERs were guided into a gas-jet
chamber of 100-mm depth through a 0.7-μm Mylar window.
The ERs were transported by a He/KCl gas-jet to achemistry laboratory. The He flow rate was 5 L min–1, andthe chamber pressure was 78 kPa. The KCl aerosols werethen collected on a glass filter for 60 s and subjected to
γ-ray spectrometry with a Ge detector after a cooling timeof 60 s. A 20-μm Al foil was placed at the entrance of thegas-jet chamber to evaluate the gas-jet transport efficiency.
Figure 1 shows a typical γ-ray spectrum observed in thenat
Gd(23Na,xn) reactions. In this work, the γ-rays of 172–177Re
and 172,173W were identified in the spectra. The decay curveof the 243.4-keV γ-ray of 174Re is shown in the inset of Fig.
1. The half-life of 174Re was determined to be T1/2 = 2.40 ±0.04 min, which agreed with that in the literature.5) Figure 2
shows the variation in the yield of 174Re as a function ofmagnetic rigidity. The dashed curve represents the result of

1.4

1.5

1.6

1.7

1.8

1.9

2.0

Magnetic rigidity, B / Tm

2.1

Fig. 2. The yield of 174Re as a function of magnetic rigidity.
References

1) H. Haba et al.: Chem. Lett. 38, 426 (2009).
2) H. Haba et al.: Phys. Rev. C 85, 024611 (2012).
3) H. Haba et al.: Phys. Rev. C 89, 024618 (2014).
4) J. Even et al.: Science 345, 1491 (2014).
5) R. B. Firestone and V. S. Shirley: Table of Isotopes, 8th ed.
(John Wiley & Sons, New York, 1996).
6) D. Kaji et al.: Proc. Radiochim. Acta 1, 105 (2011).

- 293 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Excitation function of the nat Hf(α,x)182g Ta reaction:
Cyclotron production of a long-lived γ-ray emitter 182g Ta
M. Murakami,∗1,∗2 H. Haba,∗1 and H. Kudo∗2∗1∗2

RIKEN Nishina Center
Department of Chemistry, Niigata University- 294 -

obtained for the nat Hf(α,x)176,177,178 W, 178,183 Ta,
Hf reactions, while cumulative ones were obtained for nat Hf(α,x)175,176,177,182g Ta, 175 Hf. The measured cross sections of the nat Hf(α,x)182g Ta reaction
are shown in Fig. 1 along with the calculated ones. The
cross sections in the energy range of 41–50 MeV were
measured for the first time. The excitation function
exhibits the maximum cross section of 8.3 ± 0.3 mb
at 41.5 ± 1.2 MeV. The data of Tárkányi et al.4) areconsistent with the present data at ≥30.7 MeV, whilethat at 27.6 ± 0.7 MeV (0.2 ± 0.3 mb) is much smaller
than the present one of 1.60 ± 0.08 mb at 27.2 ± 1.6
MeV. The cross sections calculated by the TALYS-1.6
code8) show systematically lower values with a similar
shape of the excitation function.
The physical thick-target yield was deduced from themeasured cross sections and the calculated stopping
power by the SRIM-2008 program.7) The deduced yieldof 182g Ta was 5.2 kBq/µAh at 50 MeV.
179m2,181

10
10

Cross
Cross section
section (mb)(mb)

We previously investigated the production of 179 Ta(T1/2 = 1.82 y) in the proton- and deuteron-induced
reactions on nat Hf1,2) for basic chemical studies of
the 105th element Db, which must be conducted at asingle-atom scale. Although the long half-life of 179 Ta
is convenient for such the chemical experiments, thedecay characteristics of 179 Ta are less suitable: 179 Ta
does not emit any γ ray in its EC decay, and it mustbe traced by measuring the characteristic X rays of
Hf, which are often interfared by X or γ rays of othernuclides.
Another long-lived Ta isotope, 182g Ta (T1/2 = 114.74d), is a γ-emitting isotope, and it has also been used asa radiotracer to explore the chemical behavior of Ta.
182g
Ta is usually produced by the 181 Ta(nth ,γ) reaction
with a high cross section of 20.5 ± 0.5 b.3) However, the182g
Ta radiotracer produced in this way is undesirable
for basic studies of Db, because it is obtained with amacro amount of the target material of Ta.
Very recently, Tárkányi et al. measured the crosssections of W, Ta, and Hf isotopes in the nat Hf(α,x)
reactions up to 40 MeV.4) As shown in Fig. 1,
they reported that the excitation function for thenat
Hf(α,x)182g Ta reaction increased with the beam energy. Because the 182g Ta tracer with high specific radioactivity can be obtained with this reaction, we further studied the production of 182g Ta in this reaction.
The excitation functions were measured by astacked-foil activation technique. 11 pairs of thinmetallic foils of nat Hf (97% chemical purity, 23 µm
thickness) and nat Cu (99.9% chemical purity, 9 µm
thickness) were stacked in an alternating sequence.
The nat Cu foils were used for monitoring the beam
current and energy by measuring the well-establishednat
Cu(α,x)67 Ga excitation function.5) The size of the
all foils was 15 × 15 mm2 . The stack was bombarded
by a 50-MeV α beam supplied by the AVF cyclotronfor 31 min. The beam was collimated within 9 mm indiameter and the average beam current was 0.23 µA.
After the bombardment and the proper cooling duration, each foil was subjected to γ-ray spectrometry
with a Ge detector.
The production cross sections were derived by thewell-known activation formula.6) The beam energies
in the individual target foils were calculated with the
SRIM-2008 program.7) The experimental cross sections were compared with the calculated ones by the
TALYS-1.6 code.8)
In this work, independent cross sections were

182g
Hf(α,x)182g
Ta

nat
nat

This
This work
work
Tarkanyi
Tarkanyi et
et al.
al. (2014)(2014)TALYS-1.6
TALYS-1.6

8
6

180
180

4

Hf(α,d)

179
179

2
0
0

Hf(α,pn)Hf(α,pn)180
180 Hf(α,d)

0
0

10
10

Hf(α,p)Hf(α,p)

20
20

30
30

40
40

50
50

60
60

α-particle
α-particle energy
energy (MeV)(MeV)

Fig. 1. Excitation function of the nat Hf(α,x)182g Ta reaction. Dashed curves indicate the individual reaction
channels evaluated by the TALYS-1.6 code.8)

References
1) M. Murakami et al.: Appl. Radiat. Isot. 90, 149 (2014).
2) M. Murakami et al.: RIKEN Accel. Prog. Rep. 47, 266
in(2014)
press.
3) S. F. Mughabghab: in Atlas of neuteron resonances (Elsevier Science, 2006).
4) F. Tárkányi et al.: Appl. Radiat. Isot. 91, 114 (2014).
5) IAEA report IAEA-TECDOC-1211 (2007).
6) M. S. Uddin et al.: Nucl. Instrum. Methods Phys. Res.
B 258, 313 (2007).
7) J. F. Ziegler et al.: Nucl. Instrum. Methods Phys. Res.
B 268, 1818 (2010).
8) A. J. Koning et al.: in Proceedings of the International
Conference on Nuclear Data for Science and Technology, edited by O. Bersillon et al. (EDP Sciences, 2008),
p. 211.

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Production cross sections of (d,x) reactions on natural ytterbium†
M. U. Khandaker＊1,＊2 and H. Haba＊2
The deduced thick-target yields indicate that a low amountof no-carrier-added radioactivity of 177gLu (2.4 MBq/A-h)
could be obtained by irradiating an enriched 176Yb target
with 11-MeV deuteron energy from a cyclotron.
400

Hermanne et al., '06
Manenti et al., '11
Tarkanyi et al., '13This work

Cross Section (mb)

350
300

177g

177

TENDL-2013 ( Lu+ Yb)
177g
177
177m
TENDL-2013 ( Lu+ Yb+ Lu-21.4%)
177
TENDL-2011 ( Yb) Ignatyuk

176

177g

Yb(d,x)250

Lu-Cum

200
150
100
50
0

0

5

10

15

20

25

30

Deuteron Energy (MeV)

Fig. 1. Excitation function of the natYb(d,x)177gLu reaction.

Integral yield (MBq/A-h)

The method for obtaining accurate information of lightcharged-particle-induced reaction cross sections has
generated significant interest in the nuclear data community
because these reactions are being increasingly used innuclear medicine, accelerator and nuclear technology, andthe testing of nuclear reaction theories. Recently, weinvestigated deuteron-induced reaction cross sections fromvarious target elements because measured data of the (d,x)
processes are limited compared to those of (p,x) processes.
A survey of literature shows that several investigations havebeen conducted for the natYb(d,x) reactions leading tovarious applications. As an example, the production of the177
Lu radionuclide via the natYb(d,x) reaction finds
applications ininternal radiotheraphy and imaging
procedures 1,2). Its half-life is long enough to allow
sophisticated preparation (e.g., shipping, labelling,
purification etc.) for use without any significant loss ofactivity. 177Lu can be produced in principle in several ways.
Currently, a large scale production of 177Lu is in practice byusing only the high flux nuclear reactor via the direct
176
Lu(n,)177Lu or indirect 176Yb(n,)177Yb177Lu routes
followed by a complex separation procedure of 177Lu fromthe Yb isotopes 3). On the other hand, the carrier-free 177Lu
is available in the charged-particle irradiations on various
targets, though its activity is relatively lower than those in
the reactor productions. However, it may be possible toovercome this deficiency with recent high-power
accelerator technologies, which enable large scale andon-site productions of 177Lu leading to its various practicalapplications.
The objective of the present study was to report the latest
cross
sectionsofthenat
Yb(d,x)169,170,171,172,173,174m,174,176m,177gLu and 169,175,177Yb
reactions that were measured with a high precision over theenergy range of 2–24 MeV using the AVF cyclotron facilityof the RIKEN RI Beam Factory, Wako, Japan. Details on
the irradiation technique, radioactivity determination, anddata evaluation procedures are available in Ref.4). Owing to
the space limitation of this report, we present only thenat
Yb(d,x)177gLu cross sections and the deduced yield in Figs.
1 and 2, respectively. Measured cross sections with an
overall uncertainty of about 12.8% are listed in Ref.4). The
cross-sections were normalized by using the natTi(d,x)48V
monitor cross sections recommended by IAEA. Measured
data were critically compared with the available literature
data, and an overall good agreement was found. However,
only partial agreements were obtained with the data
extracted from the TENDL-2013 library based on the
TALYS code.

25

Lu: This work
Lu: This work
171g+m
Lu: This work
172g+m
Lu: This work
177g
Lu: This work
175g+m
Yb: This work
170g+m

20
15
10
5
0

Fig.

169g+m

0

2.

5

10

15

20

thick

targetyieldsDeuteron Energy (MeV)

Physical

25

for

the

169g+m,170g+m,171g+m,172g+m,177gLu and 175g+mYb radionuclides.

References
1)
2)
3)
4)

†

Condensed from the article in Nucl. Inst. Meths. B. 335, 8 (2014).
Department of Physics, University of Malaya＊2
RIKEN Nishina Center＊1- 295 -J. J. Teunissen, D. J. Kwekkeboom, E. P. Krenning: J. Clin.
Oncol. 22, 2724 (2004).
M. R. A. Pillai, S. Chakraborty et al.: Appl. Radiat. Isot. 59,
109 (2003).
E. P. Horwitz, D. R. McAlister et al.: Appl. Radiat. Isot. 63,
23 (2005).
M. U. Khandaker, H. Haba et al.: Nucl. Instrum. Meths Phys.
Res. B 335, 8 (2014).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Measurement of production cross sections of Tc isotopes in the natMo(d,x)
reactions
Y. Komori,*1 M. Murakami,*1 and H. Haba*1＊1

RIKEN Nishina Center

40 MBq/µA·h, respectively. To increase the production
yields of 99Mo/99mTc and to reduce radioactivities fromby-reaction products, the use of enriched 98Mo and 100Mo
targets is favorable. Based on the present results, we willproduce 95mTc for the model experiments on Bh chemistry.
We will also develop a simple and efficient chemical
separation scheme to obtain no-carrier-added Tc tracer from
the Mo target.
70
Cross section [mb]

60

nat

Mo(d,x)95m

Tc

This work
Tarkanyi (2012)
Lebeda (2010)
Sheng (1990)
Randa (1976)TENDL-2013

50
40
30

97

Mo(d,4n)20

95

Mo(d,2n)10

94

Mo(d,n)96

Mo(d,3n)

0
0

10
20
Deuteron energy [MeV]30

Fig. 1. The excitation function of the natMo(d,x)95mTc
reaction.
103
Thick-target yield [MBq/A・h]

Chemical characterization of superheavy elements is oneof the important and challenging subjects in the field of
nuclear chemistry. We plan to conduct model experiments
for chemical studies of element 107, Bh using radiotracersof its homologs, Tc and Re. Relatively long-lived isotopes,
95m
Tc (T1/2 = 61 d) and 184gRe (T1/2 = 35.4 d) are useful for
tracer experiments. In the field of nuclear medicine, theisotope 99mTc, the daughter nuclide of 99Mo, is the mostwidely used for diagnostic imaging. Recently, the direct
production of 99Mo/99mTc using an accelerator has attracted
much attention. In this work, production cross sections of
deuteron-induced nuclear reactions on natMo (nat: natural
isotopic abundance) have been measured up to 24 MeV for
the quantitative production of Tc isotopes. The results are
discussed by referring to previously reported data and thetheoretical model code TALYS.1)
The production cross sections were measured using a
stacked-foil technique. Seventeen natMo foils (99.95%
purity, 20.9 mg/cm2 thickness), sixteen natTi foils (99.5%
purity, 9.2 mg/cm2 thickness), and sixteen natTa foils(99.95% purity,16.1 mg/cm2 thickness) were stacked in theorder ofMo/Ti/Ta. The Ti foils were used to calibrate thebeam current and the incident energy via the monitor
reaction natTi(d,x)48V.2) The Ta foils were used to attenuate
the beam energy. The size of all foils was 15 × 15 mm2. The
target stack of the Mo/Ti/Ta foils was irradiated for 1 h witha 24-MeV deuteron beam supplied from the RIKEN AVF
cyclotron. The average beam current was 0.17 μA. After theirradiation, each foil was subjected to γ-ray spectrometry
with a Ge detector.
The excitation functions were measured for thenat
93m,99,101
Mo(d,x)93m,93g,94m,94g,95m,95g,96m,96g,97m,99mTc,
Mo,
90g,92m,95m,95g,96g
89g
Nb, and Zr reactions. Figure 1 shows theexcitation function of the natMo(d,x)95mTc reaction. Our
results are in good agreement with the previously reported
data.3‒5) It can be seen that the TALYS code (TENDL-2013)
underestimates the cross sections at deuteron energies
exceeding 10 MeV. For the other reactions, most of ourresults are in good agreement with those of previous studies.
We measured the production cross section of 97mTc (T1/2 =91 d) in the deuteron energy range of 14‒24 MeV for the
first time. It was found that the TALYS code qualitatively
reproduces the shape of these excitation functions, though
there is little agreement between the experimental crosssections and the theoretical values.
Thick-target yields for all the investigated Tc, Mo, Nb, andZr isotopes were deduced from the measured production
cross sections. Figure 2 shows the thick-target yields of the
Tc isotopes as a function of the deuteron energy. The
deduced yield of 95mTc at 23.7 MeV is 0.36 MBq/µA·h. For
99
Mo and 99mTc, the deduced yields at 23.7 MeV are 9.6 and

96m

10

2

10

1

Tc

94m

Tc

95g

99m

Tc

96g

100
10

93g

93m
94g

-1

Tc

Tc

Tc

Tc

Tc

95m
97m

Tc
Tc

10-2
10-3
10-4
0

8
12 16 20 24 28
Deuteron energy [MeV]Fig. 2. Thick-target yields of the Tc isotopes
expressed as radioactivities after 1-h irradiation with
1 μA.

References

41) A. J. Koning et al.: TENDL-2013: TALYS-based EvaluatedNuclear Data Library, 2013.
2) IAEA: IAEA report IAEA-TECDOC-1211, 2007.
3) W. Sheng et al.: Inst. Nucl. Sci. Technol. Sichuan Univ. Rep.,
NST-004 (1990).
4) O. Lebeda et al.: Appl. Radiat. Isot. 68, 2425 (2010).
5) F. Tárkányi et al.: Nucl. Instrum. Meth. B 274, 1 (2012)- 296 -

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Measurements of alpha-induced cross section for 48Cr and 49Cr up to
50 MeV
H. Kikunaga,∗1,∗2 M. Murakami,∗3,∗2 Y. Komori,∗2 and H. Haba∗2

∗1
∗2
∗3

Research Center for Electron Photon Science, Tohoku University
RIKEN Nishina Center
Graduate School of Science and Technology, Niigata University- 297 -

96F

6F

E6F

㻝㻜㻞6F

㻝㻜㻟6F
996F
6F

㻯㼛㼡㼚㼠㼟㻌㻛㻌㼏㼔㻝㻜㻠6FP&U&U&U&U6F

lated values with the Talys code reproduce the experimental values of 48 Cr and 49 Cr with a reasonable accuracy although each peak position of the excitation
functions is deviated slightly.

㻝㻜㻝

㻝㻜㻜
㻜

㻡㻜㻜

㻝㻜㻜㻜
㻱㼚㼑㼞㼓㼥㻌㻔㼗㼑㼂㻕

㻝㻡㻜㻜

㻞㻜㻜㻜

Fig. 1. A γ-ray spectrum of a Ti foil sample at an eﬀectiveenergy of around 50 MeV.

㻝㻜㻜㻯㼞㼛㼟㼟㻌㼟㼑㼏㼠㼕㼛㼚㻌㻔㼙㼎㻕

Chromium is one of the essential trace elements insome animals but it also can be toxic in high concentrations. Understanding the behavior of chromium inanimals, plants, and the environment is important andinﬂuential on the various ﬁelds such as biological sciences.
The radioactive tracer technique has been widely
recognized as a powerful tool for behavior analysis ofelements in trace amounts. The isotopes 48 Cr (T1/2= 21.6 h), 49 Cr (T1/2 = 42.3 m), and 51 Cr (T1/2 =27.7 d) have potential as tracers because of their suitable half-lives. In this work, the cross sections for thereactions nat Ti(α, X)48 Cr and nat Ti(α, X)49 Cr up to
50 MeV were measured to produce these isotopes eﬃciently.
The excitation functions of these reactions were measured by the stacked-foil technique. The target stack
containing 20 natural Ti foils (99.5% pure) with thickness of 20 and 40 μm were irradiated with a α-particle
beam delivered from the RIKEN K70 AVF Cyclotronfor 30 min. The cyclotron was operated at a beam energy of 50.4 MeV, which was conﬁrmed by TOF measurement, with a mean current of around 0.4 μA.
After the irradiation, the target foils were enclosed
in a polyethylene ﬁlm separately and were subjectedto γ-ray spectrometry using a high-purity germanium
detector. The incident beam energy and ﬂux were determined by activation of the monitor foil techniqueusing the nat Ti(α, X)51 Cr reaction. The reference data
were obtained from the IAEA Reference Data1) . Theenergy loss in each foil was calculated using the TRIM
code2) .
A γ-ray spectrum of a Ti foil sample at an eﬀectiveenergy of around 50 MeV is shown in Fig. 1. The γpeaks of scandium, vanadium, and chromium are observed in the spectrum. During the tracer preparation,
it is necessary to separate chromium from titanium andthe other elements.
The cross sections for the nat Ti(α, X)48 Cr andnatTi(α, X)49 Cr reaction obtained in this work areshown in Fig. 2. For comparison, the earlier experimental data3–6) of the nat Ti(α, X)48 Cr reaction andthe values calculated using the Talys 1.6 code7) withdefault parameters are included in Fig. 1. The crosssections of 48 Cr obtained in this work is in good agreement with the earlier experimental data. The calcu-㻝㻜㻝㻌㻹㼕㼏㼔㼑㼘㻌㼑㼠㻌㼍㼘㻚㻌㻔㻯㼞㻙㻠㻤㻕㻌㼃㼑㼕㼚㼞㼑㼕㼏㼔㻌㼑㼠㻌㼍㼘㻚㻌㻔㻯㼞㻙㻠㻤㻕㻌㻴㼑㼞㼙㼍㼚㼚㼑㻌㼑㼠㻌㼍㼘㻚㻌㻔㻯㼞㻙㻠㻤㻕㻌㻼㼑㼚㼓㻌㼑㼠㻌㼍㼘㻚㻌㻔㻯㼞㻙㻠㻤㻕㻌㼀㼔㼕㼟㻌㼣㼛㼞㼗㻌㻔㻯㼞㻙㻠㻤㻕㻌㼀㼔㼕㼟㻌㼣㼛㼞㼗㻌㻔㻯㼞㻙㻠㻥㻕㻌㻌㼀㼍㼘㼥㼟㻌㻝㻚㻢㻌㻔㻯㼞㻙㻠㻤㻕㻌㼀㼍㼘㼥㼟㻌㻝㻚㻢㻌㻔㻯㼞㻙㻠㻥㻕

㻜㻚㻝

㻌

㻜㻚㻜㻝
㻝㻜

㻞㻜

㻟㻜

㻠㻜

㻡㻜

㻱㼚㼑㼞㼓㼥㻌㻔㻹㼑㼂㻕

Fig. 2. Cross sections for the nat Ti(α, X)48 Cr and nat Ti(α,X)49 Cr reactions.

References
1) IAEA-Tecdoc-1211 2001 Charged particle cross section
database for medical radioisotope production: diagnostic radiosotopes and monitor reactions (IAEA, Vienna,2001).
2) J. F. Ziegler et al.: The stopping and range of ions insolids (Pergamon Press, New York, 1985).
3) R. Michel et al.: Radiochim. Acta 32,
32, 173 (1983).
4) R. Weinreich et al.: Appl. Radiat. Isot. 31
31, 223 (1980).
152, 187
5) A. Hermanne et al.: Nucl. Instrum. Meth. B 152,
(1999).
140, 9 (1998).
6) X. Peng et al.: Nucl. Instrum. Meth. B 140,
7) A. J. Koning et al.: ”TALYS-1.0”, Proc.. Int. Conf.
Nucl. Data Sci. Technol. ND2007, Nice, France, 200704 (EDP Sciences, 2008) p.211.

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-3. Radiochemistry & Nuclear Chemistry

Improvement in the chemical yield of purified 109Cd for fee-based distribution
at the RIKEN AVF cyclotron
Y. Wakitani,＊1 S.Yano,＊1 T.Yamada,＊1 H. Haba,＊2 S. Shibata,＊2 and K. Takahashi＊2
Since October 2007, we have distributed fee-based 109Cd（T1/2 = 469.4d）,produced via the 109Ag(d,2n)109Cd reaction
using the RIKEN AVF cyclotron, to the general public.1)
After irradiation, 109Cd was chemically separated from theAg target and reaction byproducts. We have employed aseparation method involving AgCl precipitate and anion
exchange in HCl.2) However, a considerable percentage ofthe produced 109Cd tends to be lost by inclusion andadsorption on the AgCl precipitate in this method. F. W. E.
Strelow3) and M. K. Das4) applied another technique usinghydrobromic acid (HBr) for 109Cd separation. Betterchemical yield could be expected because the precipitation
step was not required in this method. In order to improvethe chemical yield for 109Cd separation, we studied a similar
technique using anion exchange in HBr without AgCl
precipitation for the chemical separation of 109Cd from theirradiated target in the present work.
Cadmium-109 was produced by irradiating a silver plate innatural isotopic abundance (chemical purity: >99.99%; size:
ø15 mm; thickness: 0.6 mm) using a 24-MeV deuteronbeam from the RIKEN AVF cyclotron. The irradiation timewas 37 h, and the average beam intensity was 9 µA. During
the irradiation, the target was continuously cooled withhelium gas and water.
Ag(1.1g)c.HNO3: 5mL ＋ H2O: 5mL＋ H2O2 × 3drops
heat to dryness

After the irradiation, 109Cd was chemically separated fromthe Ag target according to the procedure shown in Fig. 1.
The Ag target was dissolved in 5 mL of concentrated
nitric acid, 5 mL of water, and three drops of hydrogen
peroxide solution. The solution was evaporated to dryness.
The residue was dissolved in 10mL of c. HBr. This solution
was also evaporated to dryness. The residue was dissolvedin 90 mL of 7 M HBr. This 7 M HBr solution was passed
through the anion-exchange column (ø7 mm × 40 mm
height) packed with Dowex 1X8 (100–200 mesh, Cl– form).
109
Cd was adsorbed on the resin, and Ag was eluted. Thenthe column was washed with 7 M HBr and 0.02 M HCl.
109
Cd was adsorbed on the resin and the unwanted 65Zn was
eluted. Finally, 109Cd was eluted with 3 M HNO3 and H2O.
The present results are shown in Table 1,together withthose obtained in our previous study. The specificradioactivity and radionuclide purity were measured by
-ray spectrometry using a Ge detector. The chemical
impurity was also estimated by ICP-MS for a control
sample treated using the same chemical process as theirradiated Ag target. Chemical impurities were found to be
57 ppm for S and 87 ppm for Ca. The others were below 10
ppm. As shown in Table 1, the chemical yield obtained in
the present work was significantly improved from 80% to98%.
Table1. Comparison of the results of the 109Cd purification
between our previous2) and the present work.
Our previous

This

work

work

80

98

94

93

Decontamination factor of Ag

3×106

7.6×106

Radionuclidic purity>99.9%>99.9%

c.HBr: 10mL
heat to dryness
7M HBr: 90mL

Chemical yield (%)
Specific radioactivity*1

7M HBr: 10mL × 4(MBq/μg)

0.02M HCl: 5mL × 6
3M HNO3: 2mL × 3
H2O: 5mL
Dowex 1×8 , 100-200 mesh,
φ7.0mm× 40mm height

Ag

65

Zn

109

Cd

Fig. 1. Chemical separation scheme for 109Cd.

*1 (Beam intensity :10 μA, irradiation time: 48 h)
References

1) T. Kambara et al.: RIKEN Accel. Prog. Rep. 42, 295 (2008).
2) J. Kanaya et al.: RIKEN Accel. Prog. Rep. 45, 203 (2012).
3) F. W. E. Strelow et al.: Anal. Chem. 40, 2021 (1968).
4) M. K. Das et al.: The Third International Conference on
Application of RadiotraCers and Energetic Beams in Sciences(ARCEBS-14), January, 2014, Kolkata, India.

＊1
Japan Radioisotope Association＊2

RIKEN Nishina Center- 298 -

Ⅲ-3. Radiochemistry & Nuclear Chemistry

RIKEN Accel. Prog. Rep. 48 (2015)

Preparation of no-carrier-added 85Sr using the natRb(d,x)85Sr reaction
S. Yano,*1,*2 Y. Wakitani,*1 T. Yamada,*1 H. Haba*2, S. Shibata,*2 and K. Takahashi*2*1*2

Japan Radioisotope Association
RIKEN Nishina Centeramount of Sr impurities from irradiation to be 346 ng under3A irradiation for 24 h.
The amount of Sr isotopes produced by the nuclear
reaction depends on the deuteron beam dose. To apply thepresent technique to a larger-scale production, we estimatedthe expected specific radioactivity for the distribution
shown in Fig. 2. According to the present result, the purified
85
Sr solution having a high specific radioactivity of 124
MBq μg–1 could be produced under 3A irradiation for 24 husing the present chemical separation scheme. We areplanning to launch the purified 85Sr solution with a highspecific radioactivity prepared using these studied
techniques in response to customers' request.
Table 1. Measured principal chemical impurities in the 85Sr
solution after the purification process.
Element

Na

Al

Si

S

K

Concentration (ppm)

12.8

4.6

19.5

110.0

4.2

Element

Ca

Ba

Rb

Sr

Concentration (ppm)

231.8

19.8

0.1

0.1

1200

85

Sr
Sr impurities

Cross section in mb

1000
800
600
400
200
0

5

10

15
20
Energy in MeV

25

30

Fig 1. Cross sections for 85Sr and other stable Sr isotopes
calculated using the TALYS code.
specific activity （MBq mg-1 h-1）

Since 2007, we have distributed purified radioisotopes
such as 65Zn, 88Y, and 109Cd produced at the RIKEN AVF
cyclotron to the general public.1) After the Fukushima
Dai-ichi Nuclear Power Plant accident in 2011, distributionof 85Sr solutions having high specific radioactivity was
required to develop analysis techniques for discharged
radio-strontium. In response to these demands, we intended
to produce 85Sr via the natRb(d,x)85Sr reaction using a
24-MeV deuteron beam from the RIKEN AVF cyclotron.
We also studied a chemical separation procedure to obtain apurified 85Sr solution using a no-carrier-added technique. In
the previous study,2) we successfully produced a 85Sr
solution having high radionuclidic purity. To estimate
specific radioactivity, however, chemical purity should be
estimated carefully. In the present study, we therefore
evaluated chemical impurities in the prepared solution andassessed the applicability of the natRb(d,xn)85Sr reaction andthe no-carrier-added technique to the larger-scale
production of the 85Sr solution for distribution.
The 85Sr isotope used in this work was produced byirradiating a RbCl disk (Sigma-Aldrich; chemical purity: >99.99%; thickness: 500 mg cm-2) of natural isotopic
abundance with 24-MeV deuterons. The average beam
intensity was 159 nA. The irradiation time was 17 min. 85Sr
was chemically separated in accordance with the scheme
using a two-step chromatographic separation technique that
we had reported.2) The chemical impurities in 5.0 mL of thispurified solution was evaluated using ICP-MS (Agilent
Technologies; Model 7700) for a control sample, which wastreated using the same procedure as that for the irradiatedsample.
The production yield of 85Sr was estimated to beapproximately 3.90 MBq·μA–1 h–1 under the present
experimental condition. The chemical yield reached as highas 94%. As shown in Table 1, the Rb target material was
successfully removed and the decontamination factor of Rb
reached 106. The strontium content required for thedetermination of specific radioactivity was measured to be
0.1 ppm (equivalent to 614 ng) in this analysis. However,the Sr impurities originate from not only the environment
but also nuclear reactions. To estimate stable Sr isotopes
produced by nuclear reactions, we calculated the expected
Sr impurities by comparing the production yield obtained in
the present experiment with that simulated by the TALYS
code.3)Fig. 1 shows the simulated cross sections of 85Sr and otherstable Sr isotopes. The production yield of 85Sr was 4.37
MBq·μA-1 h-1. To estimate the production yields for other Sr
isotopes, the calculated production yields for the stable Sr
isotopes were normalized by the calculated rate for 85Sr andthe one obtained in the present experiment. As a result, the

700
600
500
400
300
200
100
0

0

100

200

300

400

500

600

700

800

900

24 MeV deuteron beam dose （A*h）

Fig 2. Calculated specific radioactivity for distribution of
the purified 85Sr solution as a function of the deuteron beam
dose.
References
1)
2)
3)

- 299 -

T. Kambara et al.: RIKEN Accel. Prog. Rep. 42, 295 (2008).
S. Yano et al.: In this report.
A.J. Koning et al.: ND2007, (2007), p.211-214

4. Radiation Chemistry and Biology

Ⅲ-4. Radiation Chemistry & Biology

RIKEN Accel. Prog. Rep. 48 (2015)

Localization of Rad51 and phosphorylated DNA-PKsc after
heavy-ion irradiation in mammalian cells
M. Izumi*1 and T. Abe*1
Accelerated heavy-ion particles with high linear
energy transfer (LET) induce complex clustered DNA
damage, which is considered an obstacle to efficient
repair and causes different biological effects compared with
low-LET radiation such as X-ray. However, the biologicaleffects of heavy-ion irradiation are not fully understood at
the molecular level. To analyze the repair mechanism for
DNA double-strand breaks (DSBs) caused by heavy ions,
we have investigated cell sensitivity to heavy ions using thewild-type CHO-AA8 cells and two CHO mutant lines
deficient in homologous recombination (HR)1) or
non-homologous end-joining (NHEJ)2) in a previous study3)
and found that HR, but not NHEJ, is primarily involved in
the repair pathway induced by high-LET ionizing radiation.
In this study, we investigated the localization of
Rad51 and the phosphorylated form of the catalytic subunitof the DNA-dependent kinase (DNA-PKcs) in CHO cells
after
X-ray
or
heavy-ion
irradiation
withimmunoflorescence staining. Rad51 is essential for HR
and is involved in strand transfer during homologous
pairing,4) whereas DNA-PKcs is involved in NHEJ andphosphorylated upon DNA damage on threonin-2609.5)
One hour after X-ray irradiation, hundreds of Rad51
or phosphorylated DNA-PKcs foci were observed in nuclei(Fig. 1A), although they were not colocalized with eachother. The number of foci started to decrease 4 h after
irradiation and fractions of Rad51 and phosphorylated
DNA-PKcs foci were colocalized. A small fraction of
DSBs was not repaired within 24 h (data not shown), andthe foci remaining at 16 h after irradiation contained both
Rad51 and phosphorylated DNA-PKcs, suggesting that
irreparable DSBs recruite repair proteins of the NHEJ andHR pathways.
On the other hand, large fractions of Rad51 andphosphorylated DNA-PKcs foci were colocalized 1 h afteriron-ion irradiation (LET = 1000 keV/µm) (Fig. 1B),
suggesting that the majority of DSBs have different
structures in nature. Although our previous results suggestthat NHEJ is not involved in the repair pathway after
heavy-ion irradiation,3) we observed that phosphorylated
DNA-PKcs was recruited to DSBs. These results suggestthat repair proteins of both pathways are recruited to DSBs
induced by heavy ions, and finally HR is selected fordamage repair.
Currently, we are investigating how the cell cycle andLET affect the repair kinetics and colocalization of Rad51
and phosphorylated DNA-PKcs. We are also planning to
examine the localization of 53BP1 and Rif1 after heavy-ion
irradiation, which are involved in the selection of repair
pathways for DSB repair.6,7)

Fig. 1 Representative images of CHO nuclei (blue) with
Rad51 (green) and phosphorylated DNA-PKsc (red) foci.
The cells were irradiated with 5 Gy of X-ray (A) or iron
ions (B) and fixed with 4% paraformaldehyde at indicatedtime points after irradiation. Foci formation of Rad51 andphosphorylated
DNA-PKcs
wasdetected
byimmunofluorescence staining.
References*1 RIKEN Nishina Center- 301 -

1) R.S. Tebbs et al.: Proc. Natl. Acad. Sci. USA 92, 6354 (1995)
2) S.R. Peterson et al.: Proc. Natl. Acad. Sci. USA 92, 3171
(1995)
3) M. Izumi and T. Abe.: RIKEN Accel. Prog. Rep. 47, in press(2014)
4) A. Shinohara et al: 69, 457 (1992)
5) P. Douglas et al.: Biochem. J. 368, 243 (2002).
6) C. Escribano-Diaz et al.: Mol. Cell 49, 872 (2013)7) J. R. Chapman et al.: Mol. Cell 49, 858 (2013)

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-4. Radiation Chemistry & Biology

Low-dose high-LET heavy ion-induced bystander signaling
M. Tomita,∗1,∗2 T. Tsukada,∗1 and M. Izumi∗1
The radiation-induced bystander response (RIBR) isa cellular response induced in nonirradiated cells thatreceive bystander signals from directly irradiated cells
within an irradiated cell population.1) The RIBR induced by low doses of high-LET radiations is an important issue concerning the health of astronauts andin heavy-ion radiation cancer therapy. Here, we investigated the molecular mechanisms underlying andbiological implications of the RIBR induced by suchlow doses of high-LET radiations.
Figure 1 shows the clonogenic survival curve of normal human ﬁbroblast WI-38 cells irradiated with Fe
ions (1000 keV/µm). Cells were harvested from thecell culture ﬂask immediately (0 h) or 16–24 h after
irradiation, and the surviving fraction was determinedby using a colony formation assay. At doses below 0.2
Gy, the surviving fractions of the cells harvested 1624 h after exposure to Fe ions were much lower thanthose extrapolated from higher doses above 0.1 Gy using the linear-quadratic model (LQ model).2) On theother hand, the cells harvested immediately after exposure did not show such a high cell killing eﬀect atlower doses. These results suggest that an adequate
incubation period is necessary for the bystander signal
induction and transfer.
Previously, we have reported that reactive oxygen
species (ROS), gap-junction intercellular communication (GJIC), and cyclooxygenase-2 (COX-2) protein as
well as nitric oxide (NO) may be involved in high-LET
radiation-induced bystander signal transfer.3) Here, weshow the progress of results reﬂecting new data [Fig.
2]. Lindane and NS-398 (an inhibitor of GJIC and
COX-2, respectively) were dissolved in DMSO (a scavenger of ROS). DMSO did not signiﬁcantly suppress
the bystander cell killing eﬀect. In contrast, lindane,
NS-398, and c-PTIO (a scavenger of NO) signiﬁcantly
suppressed cell death to similar levels. Cells pretreatedwith both c-PTIO and lindane did not show signiﬁcantly higher surviving fraction than those pretreatedwith lindane or c-PITO alone. These results suggestthat bystander signaling through GJIC and the cell
culture medium induces the bystander cell killing effect in a coordinated manner.
Currently, we are examining the role of the NFκB/Cox-2/prostaglandin E2 and NF-κB/iNOS/NO
pathways,4) which may be activated in bystander cells.

∗1∗2

RIKEN Nishina Center
Radiation Safety Research Center, Central Research Institute of Electric Power Industry- 302 -

Fig. 1. Survival curves of WI-38 cells. Conﬂuent monolayers of WI-38 cells were irradiated with 90 MeV/u Fe
ions (1000 keV/µm) and the cells were harvested immediately (0 h) or 16–24 h after irradiation. The surviving
fraction was determined by using a colony forming assay. Panel A shows all data obtained in this study.
Panel B shows surviving fractions at doses below 0.5
Gy. The error bars represent the standard deviations.

Fig. 2. Eﬀect of inhibitors or scavengers. DMSO (0.1%),
lindane (Lin, 50 µM), c-PTIO (20 µM), or NS-398 (50µM) was added to the medium 2 h before irradiation.5)
WI-38 cells were irradiated with 0.1 Gy Fe ions. The
error bars represent the standard errors of the mean
(SEM) (n=3–4).*P < 0.05, for comparison with irradiated control cultures.

References
1) M. Tomita and M. Maeda: J. Radiat. Res. 56, 205(2015).
2) M. Tomita et al.: RIKEN Accel. Prog. Rep. 42, 276(2009).
3) M. Tomita et al.: RIKEN Accel. Prog. Rep. 47, in press.
4) T. K. Hei et al.: Curr. Mol. Pharmacol. 4, 96 (2011).
5) M. Tomita et al.: Radiat. Res. 179, 200 (2013).

Ⅲ-4. Radiation Chemistry & Biology

RIKEN Accel. Prog. Rep. 48 (2015)

Effect of days after irradiation on lethal rate of F3 progeny in the
fruit fly mutation isolation system
K. Tsuneizumi*1 and T. Abe*1
Heavy-ion beam mutagenesis is generally recognized as
an effective method for mutation breeding1, 2). Although thismethod was greatly successful with a plant, its applicationis still limited for animals. We therefore plan to acquire
more basic data to set up optimal conditions for theirradiation system by heavy-ion beam using Drosophilamelanogaster (fruit fly) as a useful model.
In a previous study, we have developed and improved astable mutant isolation system using fruit flies by
employing carbon-ion beam irradiation. In the system, weprepared a useful genetic tool, called balancer chromosome,to prevent genomic recombination. We also prepared small
commercial cuvettes with a plane surface to apply
heavy-ion beam equally to overcome unstable results3).
Then, we could observe a linear correlation between anumber of F1 progeny and an irradiation dose when themales were irradiated with a carbon-ion beam3).
In this report, we introduced a new machine to improvethe mutant isolation system [Fig. 1a]. If fruit flies are putin empty cuvettes for irradiation, they die because ofdryness. So, it is necessary to put fly foods in the cuvettes toavoid dryness.	
 However, it was difficult to prepare many
samples without polluting the irradiated surface because thefood was stuffed manually. The machine made it possible todispense fly foods to many cuvettes without polluting theside surface of the cuvettes.
We prepared powdered fly foods for the machine,
because it is easy to use and is commercially available. We
considered using a needle tip for dispensing viscous fly
foods to many cuvettes continuously [Fig. 1b]. Then we
optimized the water-to- powder ratio for injection. Next, we
set parameters for the dispensing machine using a program,
such that the surface of fly foods was slanted in a cuvette[Fig. 1c]. As a result of these examinations, we were able
to prepare more than 300 cuvettes in 2 hours.
To optimize the conditions for the mutant isolation
system, we estimated the suitable state of F1 progeny that
includes a possibility of chromosome damages. Various
developmental cells are intermingled in testis of irradiatedfruit fly. The repair mechanism to DNA damages and thesensitivity to irradiation are different in each cell4). So, it isimportant to know when flies with high probability of DNA
damage are born. Because DNA damages to important
genes for survival can be judged by the homozygotes bornin F3 progeny, we measured a frequency of lethal rate of F3progeny [Fig. 2]. The progeny being born 4 days after
irradiation at 10 Gy dose levels recorded the maximum
frequency of lethal rate [Fig. 2]. These data will be helpful
for optimizing the irradiation system in the future.
＊1

RIKEN Nishina Center

Fig. 1. a) A photograph of a micro dispensing machine(Shopmaster 300DS made by Musashi engineering, Inc.). b)
A photograph of magnified view of dispensing fly foods
into cuvettes. c) A diagram of a comparison of a surface of
fly foods in the cuvettes. A dispensing program has been
tuned so that a shadow does not form in the cuvettes by fly
foods. The left figure shows a failure caused by fly foodshadow. The right figure shows appropriate placement of
fly food. Heavy-ion beams are indicated as red arrows.

Fig. 2. A change in frequency of lethal rate of F3 progeny.
Parental male flies were irradiated with a carbon-ion beamwith linear energy transfer values of 80keV/µm. F: filial
generation.
References

1) T. Abe et al.: in Plant Mutation Breeding and Biotechnology,
edited by Q. Y. Shu et al. (CABI, Oxfordshire, 2012), p.99.
2) A. Tanaka et al.: J. Radiat. Res. 51, 223 (2010).
3) K. Tsuneizumi et al.: RIKEN Accel. Prog. Rep. 46, 255 (2013).
4) M. Ashburner et al.: Drosophila a Laboratory Handbook(CSHL Press, New York, 2005).

- 303 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-4. Radiation Chemistry & Biology

Extra-early-flowering wheat mutants produced by heavy-ion-beammutagenesis†
A. Nishiura,＊1 Y. Kazama,＊2 T. Abe,＊2 N. Mizuno,＊3 S. Nasuda,＊3 and K. Murai＊1
To avoid harvesting in the rainy season, early floweringor early heading is one of the most important characteristics
for bread wheat (Triticum aestivum) in East Asia, including
Japan. A detailed understanding of the flowering
mechanism in wheat plants is of value not only for wheat
breeding but also for basic scientific research. From thelarge scale mutant panel of diploid einkorn wheat (Triticum
monococcum)strain
KU104-1
developedbyheavy-ion-beam irradiation1), we identified four extra
early-flowering mutants, named extra-early-flowering1(exe1), exe2, exe3, and exe4. The four exe mutants fell into
two
groups,namelyType
I(moderately
extra-early-flowering type; exe1 and exe3) and Type II(extremely extra-early-flowering type; exe2 and exe4),
based on a field experiment.
In a growth chamber, leaf-emergence timing in wild-type(WT) and exe mutant plants was examined under long-day(LD) or short-day (SD) conditions. Under LD conditions,
WT plants averaged about 180 days from sowing toflag-leaf unfolding. In contrast, Type I exe mutants took
about 65 days and Type II about 50 days. WT plants
transited from the vegetative to reproductive growth phaseat the 9-leaf stage, while exe mutants showed earlier phasetransition: at the 5-leaf stage for exe1 and exe3 (Type I) andthe 4-leaf stage for exe2 and exe4 (Type II). In WT plants,
the flag leaf occurred at the 18-leaf stage, while in exe1,
exe2, exe3, and exe4, the flag leaf appeared at the 9-leaf,
8-leaf, 9-leaf, and 7-leaf stages, respectively. Under SD
conditions, WT plants transited from the vegetative toreproductive growth phase at the 13-leaf stage. In contrast,

exe
Fig. 1. Extra-early-flowering (exe) mutant plants grown in
the field.
†

Condensed from the article in Breeding Science 64, 213 (2014)
Department of Bioscience, Fukui Prefectural University＊2
RIKEN Nishina Center＊3
Graduate School of Agriculture, Kyoto University＊1

exe1 and exe3 mutants (Type I) transited at the 8-leaf stage,
while exe2 and exe4 mutants (Type II) transited at the 4-leaf
stage. Interestingly, the phase transition was early (at the
4-leaf stage) in Type II exe mutants under both SD and LD
conditions. Comparing Type I exe mutants between SD and
LD conditions indicates that these mutants retained
photoperiodic sensitivity. However, Type II exe mutants had
lost almost all photoperiodic sensitivity.
In wheat, it was found that three genes mainly control theflowering, namely VERNALIZATION 1 (VRN1), VRN2 and
VRN3. The analysis of VRN1, a flowering-promoter gene,
showed that it was more highly expressed in seedlings at theearly developmental stages in Type II mutants than in TypeI mutants. The up-regulation of VRN1 expression in exe
mutants was associated with earliness in flowering under
LD conditions. The extremely extra-early flowering in TypeII mutants was associated with a more rapid up-regulationof VRN1 expression than in Type I mutants. It is notablethat a similar level of VRN1 expression was observed at thephase transition in each exe mutant: at the 5-leaf stage forType I mutants and at the 4-leaf stage for Type II mutants.
This finding suggests that the level of VRN1 expression iscorrelated with the phase transition from vegetative toreproductive growth and may act as a threshold forflowering competency in wheat plants.
The original KU104-1 is an einkorn wheat strain thatcarries a null allele of the VRN2 gene, a repressor offlowering. Thus, our results indicate that the level of VRN1
expression controls earliness in flowering in exe mutants
independently of VRN2. In bread wheat, it has been known
that winter cultivar quantitatively requires prolonged cold
temperature to yield vernalization saturation. Some wintercultivars require 2-4 weeks of low temperature to reach the
maximum vernalization effect on heading, and others
require more than 4 weeks. Positional cloning of the gene
was performed for the duration required for vernalization,and the results demonstrated that this trait is controlled by
the recessive VRN1 gene on the A genome at the protein
level2). A previous study also revealed that the binding
ability of the VRN1 protein to TaHOX1 was associated withthe requirement of low-temperature duration to reachvernalization saturation. These findings, together with thepresent exe study, support our model of gene network forflowering: VRN1 plays a central role in the flowering
pathway3).
References

1) K. Murai et al.: Nucl. Instr. Meth. Phys. Res. B 314, 59 (2013).
2) G. Li et al.: Plant J. 76, 742 (2013).
3) S. Shimada et al.: Plant J. 58, 668 (2009).

- 304 -

Ⅲ-4. Radiation Chemistry & Biology

RIKEN Accel. Prog. Rep. 48 (2015)

Heredity analysis of radiation induced semidwarf mutants in Tartary
buckwheat (Fagopyrum tataricum Gaertn.)
T. Morishita, *1, *2 Y. Hayashi,*2 and T. Abe*2
Recently, heavy-ion beams have been regarded as agood mutagen for plant breeding, and as such various
varieties have been developed by using heavy-ion beams.
We previously reported the biological effects and mutationinduction by ion beams in Tartary buckwheat1) 2). We
obtained semidwarf mutants named IRBFT-45, 63, 67 and
77. The semidwarf type is important for improving thelodging resistance and yielding ability in buckwheat
breeding. These semidwarf mutants were obtained byirradiating dry seeds of Tartary buckwheat (var.
Rotundatum) with 40 Gy of carbon (23 keV/μm, 12C6+), 100
Gy of carbon (39 keV/μm, 12C6+), 30 Gy of iron (624keV/μm, 56Fe24+) and 20 Gy of argon (280 keV/μm,
40
Ar17+) ions3). On the other hand, we obtained similarsemidwarf lines named IRBFT-6 and 20 by irradiating dry
seeds with 50 and 500 Gy of gamma rays (60Co, 44.4TBq)
at the Institute of Radiation Breeding, and IRBFT-38 by
irradiating dry seeds with 40 Gy of helium ions (16 keV/μm,
4He2+) at JAEA. The plant height of all of these semidwarflines was 50-60% of the original varieties. We performed
heredity analysis on these semidwarf mutants.
All of the F1 plants obtained by crossing among
IRBFT-6, 20, 45 and their original varieties showed wild
type like phenotype. The phenotypes in the populations of
F2 were segregated into wild type like and semidwarf, andthe appropriate segregation ratio was found to be 3:1 by achi square test (Table 1). This suggests that the trait ofsemidwarf in IRBFT-6, 20, and 45 was controlled by anuclear single recessive gene.
To classify these semidwarf lines, a half diallel cross
was performed (Fig. 1). When F1 plants showed asemidwarf phenotype, the causal gene of the parents wasconsidered to be the same. When F1 plants showed
wild-type like phenotype, the causal genes of the parents
were considered to be different. From the phenotype in F1,
it was estimated that these 7 lines were classified into 2
groups. One consisted of IRBFT-6, 20 and 45, which had acommon semidwarf gene termed sdA. The other consistedof IRBFT-38, 63, 67 and 77, which had another semidwarf
gene termed sdB.
Because a crossing test with original varieties was not
performed in sdB lines (IRBFT-38, 63, 67 and 77), thenumber of sdB gene(s) was not determined. Instead, weinvestigated the segregation ratios in the F2 plants generated
by crossing sdB lines with IRBFT-20 (sdA) (Table 2). The
phenotypes in the populations of F2 were segregated into
wild type like and semidwarf. Their segregation ratios were
＊1
＊2

NARO Hokkaido Agricultural Research Center
RIKEN Nishina Center

then fitted to the two recessive gene model (Table 2). These
results indicated that sdB was controlled by a single
recessive gene different from sdA.
Table 1. Segregation patterns of plant type crossing between
semidwarf lines and the original variety in the F2
population
No. of plants

Cross combination
Pontivy×IRBFT-6
Hokkai T8×IRBFT-20
Rotundatum×IRBFT-45♂
♀

Wild type21
54
60

Semidwarf
9
17
13

χ2
3：1
0.4
0.04
2.01

p
0.53
0.84
0.16

IRBFT-20 IRBFT-38 IRBFT-45 IRBFT-63 IRBFT-67 IRBFT-77

IRBFT-6

SD 6

IRBFT-20
IRBFT-38

WT 3

SD 4

WT 5

WT 4

WT 4

WT 4
(SD 1)

SD 5

WT 4

WT 7

WT 5

WT 2
(SD 1)

SD 5

SD 3

SD 1

WT 3

WT 4

WT 4

SD 17

SD 14

IRBFT-45
IRBFT-63
IRBFT-67

SD 16

Fig. 1. Phenotypes of F1 plants by a half diallel cross. SD means
semidwarf type, and WT means wild-type like. Numbers inparentheses are the numbers of research plants.

Table 2. Segregation patterns of plant type crossing between
semidwarf lines in the F2 population
Cross combination
IRBFT-20×IRBFT-38
IRBFT-20×IRBFT-63
IRBFT-20×IRBFT-67
IRBFT-20×IRBFT-77

References

No. of plants
Wild type
109
64
137
130

Semidwarf
85
56
103
109

2

χ
9：7
0.01
0.41
0.07
0.33

p
0.99
0.52
0.79
0.56

1) T. Morishita et al.: RIKEN Accel. Prog. Rep. 36, 137 (2003)
2) T. Morishita et al.: RIKEN Accel. Prog. Rep. 40, 255 (2007)
3) T. Morishita et al.: RIKEN Accel. Prog. Rep. 41, 232 (2008)- 305 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-4. Radiation Chemistry & Biology

Effects of Ar-ion beam irradiation on inducing mutations
in chrysanthemum and sweetpotato



＊1


Y. 
Tanokashira,＊ 1 
J. 
Nagai,＊ 1 
S. 
Nagayoshi,＊and 
T. 
Abe＊2


It 
is 
expected that 
heavy-ion beam 
irradiation will 
be
useful in 
inducing 
mutations for 
plant 
breeding in  

agriculture1), 2). 
However, 
effects of
Ar-ion beam 
irradiation 
on manyplant 
species 
remain 
unexplained. 
Therefore,
 effects of Ar-ionbeam 
irradiation 
on 
chrysanthemum and
sweetpotato, 
which are 
major 
crops in 
Kagoshima
Prefecture, was 
investigated and 
compared with 
C-ion

beams in 
this 
study.
 At 
first, we 
investigated 
effects of Ar-ionbeam
  irradiation 
on regenerationof chrysanthemum.
Leaf 
bladesof 
the 
spray-mum 
cultivar 
“Southern 
Chelsea”, 
which was 
developed in
Kagoshima 
Prefecture, were 
irradiated by
 0.1, 
Ar-ion 
beams 
(LET: 280 
keV/μm) at 
doses of0.3, 
0.5,

1, 
2, 
and 3 Gy, 
and 
C-ion 
beams 
(LET: 23 
keV/μm) at 
doses

of 
1, 
2, 
and 3 
Gy. 
After 
irradiation, 
these 
tissues were
 
cultured in 
vitro, and 
the numberof 
directly 
regenerated

plants from 
adventitious 
shoots1) were 
counted. 
The relative   
regeneration
rates of Ar
ions 
were 
lower than 
that 
of C
ions  
atthe 
same 
dose, andthe 
proportion 
between 
relative  
regeneration
rates of Ar
ions 
and 
C 
ions 
(Ar/C) 
became 
 
 1).

loweraccording to 
increasing of irradiation
doses (Fig.
  
In
addition, the 
relative 
regeneration rate 
of Ar
ions 
became 
higheraccording to 
decreasing of 
irradiation 
doses; 
37.8%,
 and 
 of
 1,
 0.5, and 
65.9%,
90.9% at doses
0.3 
Gy, (Fig.
 respectively1). 
From 
past 
findings, the 
optimal dose 
forinducing 
mutations 
in 
chrysanthemum will 
be 
at 
the when 
dosethe 
relative 
regeneration rate 
has 
declined  
considerably,and 
this 
optimal dose 
of C
ions 
will 
be 2 Gy3).
 
 Ar
 
Consequently, theoptimal dose ofions 
is 
estimated 
to 
be


0.5 
Gy 
assuming that 
the 
relative 
regeneration rate 
of Ar
ions 
for 
optimal dose 
is 
at 
the 
same 
level with C 
ions.

 
Fig. 
1. 
Comparison of 
the 
relative 
regeneration rateby 
the 
Ar-ion “Southern  
and 
C-ion beam 
irradiation in
Chelsea”. The
relative
 regeneration rate 
means the 
rate 
of 
regenerated 
shoots afterion 
 
beam 
irradiation toradiationless 
regenerated shoots,
which were
directly 
developed from 
adventitious 
shoots1). Next, we 
investigated 
the 
effects of Ar-ionbeam
irradiation 
on 
inducing 
mutations for 
sweetpotato. 
Axillary 
 
shoots of invitro-grown 
stems of cultivar“Konamizuki”
＊
＊1
＊
＊2

 Prefectural Institute for Agricultural Development
Kagoshima Nishina Center
RIKEN

 
 
  at
wereirradiated 
by Ar-ionbeams (LET:
280 keV/μm)   3 
doses
of 1,
2, andGy, 
and 
C-ion 
beams 
(LET: 23 
keV/μm)at 
doses of 
10 
and 
15 
Gy. 
After 
irradiation, 
these were 
 weeks, and 
tissues
cultured for 
about 10the 
growth morphological mutations 
and
of 
in 
vitro 
plants were  
observed.
In 
Fig. 
2, 
mortality rate,
stunting 
rate, and  
mutationrate 
mean 
the 
rate 
of samples
that 
died without 
 stem 
germination,
samples whose
lengths were 
less 
than 2
 and 
 leaves have 
 
cm,
samples whose
one 
or moreincisions, to investigated 
respectively,
samples. 
The 
original leaf 
of 
 experimental
cultivar“Konamizuki” is 
cordate. 
Under the  mortality 
conditionused 
in 
this 
study, therates of 
both 
Ar 
 
ions
and 
C 
ions 
were relatively
low 
(Fig. 2) . In 
contrast, the rate   
stunting
at 3 Gy Ar
ions 
was 
about 4.7
times and 
about 
  ions,
1.8
times higher
than 
those 
at 
10 
Gy 
and 
15 
Gy C (Fig.
 
respectively2). 
This 
fact 
suggests that 
the 
dose 
of Ar  

ionsthat 
strongly 
influences thegrowth of sweetpotato 
will
be 
lower than 
that of C 
ions. 
Furthermore, the 
 2 Gy Ar 
morphologicalmutation rate ations 
was 
25.7%
  
(Fig.
2). 
This rate
was 
highest 
under all 
irradiation 
 morphological mutations 
conditions.
Because manycan 
be at 
detectedthe 
mature 
stage, the 
reason that 
the 
mutation  
  
rate
at 2 Gy Ar
ions 
is higerthan 
that 
at 3 Gy Ar
ions 
could
 the high 
  
bestunting rate
at 3 Gy Ar
ions. 
Moreover, some 
of mutations 
  were 
theleading to 
the incisionof leavesthe  resultsof 
spontaneous 
mutation; however,the 
mutation rate 
 underheavy-ion beam 
irradiation 
was 
clearly higher
than 
 non-irradiation.
 These morphological
that
observed under 
mutantsare 
chimera 
plants 
generated from multicellular 
  
tissues.
Therefore, 
we triedto 
separate mutationsites by  
 
cuttingout mutation
tissues. On 
the 
basis of 
these results,it 
 a  of Ar-ion 

issupposed thatlow dosebeams 
strongly affects 
 mutation 
onthe 
growth 
and morphologicalof sweetpotato.

 2.
 
 

Fig.
Effects of 
heavy-ion beamirradiation 
on sweetpotato  
 cultivar“Konamizuki”. 
The 
period andtimes of irradiationand the numberof 
samples 
(from 96 
to 
187) 
were 
different 
based on the  
line
class anddoses.

References  
 Hot.
 
 12,
 245 (2013)
1)
K. Uenoet al.:
Res. (Japan)  Res.
 16,
 67
 (2014)
2)
T. 
Abe 
et 
al.: Breed.
  
 Breed.
  

3)
K. Uenoet al.:
Res. 
3(Separate Vol. 2),62 (2001)- 306 -

Ⅲ-4. Radiation Chemistry & Biology

RIKEN Accel. Prog. Rep. 48 (2015)

Rapid screening of heavy-ion-induced large deletion mutants by using
quantitative real-time PCR in Arabidopsis thaliana
Y. Kazama,＊1 T. Hirano,＊1,＊2 K. Ishii,＊1 M. Yamada,＊1 Y. Shirakawa,＊1 S. Ohbu,＊1 and T. Abe＊1
In heavy-ion irradiation, the size of deletions can bevaried according to different values of linear energy transfer(LET). In irradiation experiments on Arabidopsis thaliana,
we previously found that beams with LET of 30 keV/μm
induced small deletions (1 to 51 bp) with high frequency,
and this size is appropriate for disrupting a single gene.1)
Thus, 30-keV/μm beams are suitable for use in mutation
breeding as well as in reverse genetics to find single genedisruption lines in conjunction with SNP detection systems.
On the other hand, beams with LET of 290 keV/μm caused
larger deletions (1 kbp to several hundred kbp).2) Suchhigh-LET beams can be used for generating mutants lacking
tandemly arrayed genes (TAGs) that have functions similar
to one another, allowing us to investigate the function of
TAGs. Thus, we are now developing a deletion-mutant
correction by screening them from M3 generations after
being irradiated with 100-, 200-, or 290-keV/μm beams.
The screening is performed using array-CGH designed for
all TAGs of A. thaliana. Researchers will be able to screen
deletion mutants of interest from our stock of over 10,000
of 290-keV/μm irradiated M2 lines.
However, screening deletion mutants is time-consuming.
Conventionally, it was performed by PCR in the M2
generation, in which only homozygous deletions(HomDels) could be detected unless primers were designed
to have deletions placed between them (Table 1). In casethat the HomDel mutant of interest is lethal, no candidate
would be obtained. By contrast, heterozygous deletions(HetDels) can be inherited over generations, and are foundin the M2 generation with about two times frequency
compared with HomDels (Fig.1). If a HetDel is easily
detected in the M2 generation (See Fig. 1), the screening
pool size can be reduced. Herein, we tested the quantitative
real time PCR (qPCR) for detection of a HetDel.
For our test, we selected an Arabidopsis line
(C200-84-N2) from our stock induced by carbon-ion beamirradiation (135 MeV/nucleon, 200 keV/μm) at a dose of 75
Gy. This line has a 3.5-kbp deletion at the2762232-2765771 position on chromosome 4. The 3.5-kbp
deletion is harbored as a HetDel in the M2 generation. Thus,
four individual progenies of the M3 plants of C200-84-N2
were used for qPCR, since some of them would have a
3.5-kbp deletion as the HetDel.
qPCR was performed by using LightCycler and the
Universal Probe Library detection format (Roche
Diagnostics, Penzberg, Germany). Relative amplification
ratios between the 3.5-kbp deleted and non-deleted regions
were calculated by using the ΔΔCp method. Sample A
RIKEN Nishina Center＊2
Faculty of Agriculture, University of Miyazaki＊1

Fig. 1. Assumed deletion screening in M2 generation by
qPCR. HetDels are detected more frequently than HomDels
for heritable (A) and inheritable (B) cases. No symbol
indicates individuals that have no deletion.
showed the same relative amplification ratio as wild-type(Fig. 2). Samples B and C showed about half-level of theratio as compared to wild-type, indicating that they contain
HetDels. Sample D showed no amplification. These results
indicate that large deletions can be detected even if they areheterozygous. Our irradiated M2 seed stocks in conjunction
with this method will prove a powerful tool for analyzing
the functions of TAGs.

Fig. 2. qPCR in four M3 plants (A to D). Data are expressed
as fold changes compared with values in wild-type (wt).
Error bars indicate ±SD. N=3 in each plant. White
arrowheads and a black arrowhead indicate HetDel and
HomDel, respectively. *, p< 0.01 compared to wild-type.
References
1) Y. Kazama et al.: BMC Plant Biol. 11, 161 (2011).
2) T. Hirano et al.: Mutat. Res. 735, 19 (2012).

- 307 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-4. Radiation Chemistry & Biology

LET-dependent effect on mutation induction DNA repair-deficient backgroundin Arabidopsis thaliana
K. Ishii,*1 Y. Kazama,*1 Y. Shirakawa,*1 S. Ohbu,*1 and T. Abe*1
A previous study on the effect of LET on inducing
mutation revealed that the most effective value of LET(LETmax) on dried seeds of Arabidopsis thaliana was 30.0
keVμm-1, within a range 22.5 to 640 keVμm-1.1) LET istherefore an important factor in mutation induction. In the
mutagenesis process, the DNA double-strand break (DSB)
repair system is concerned with the production of mutations.
There are two major DSB repair pathways:
non-homologous end joining (NHEJ) and homologous
recombination repair (HRR) function in eukaryotic cells.2)
NHEJ and HRR are independent pathways. HRR is arelatively error-free pathway because it utilizes thehomologous region of a sister chromatid to repair thedamaged strand, whereas the NHEJ pathway is relatively
error-prone.
To determine whether DSB repair pathways are involvedin the LET-dependent effect on mutation induction, we
intended to investigate the effect of LET in the DSB
repair-deficient background. We planned to measure themutation rates after heavy-ion beam irradiation with LET
values 22.5 and 30 keVμm-1 in the three mutant lines: 1) the
HRR pathway-deficient mutant line, 2) the NHEJ
pathway-deficient mutant line, and 3) both HRR and NHEJ
pathway-deficient mutant line. Here, we report the mutation
rates of the Rad54-deficient mutant as the HRR
pathway-deficient mutant line.
Seeds of the APG3(+/-) mutant (CS16118) and the
AtRad54(-/-) mutant (SALK_038057) were obtained from the
Arabidopsis Biological Resource Center (ABRC, Ohio
State University) and the European Arabidopsis StockCentre (NASC, the University of Nottingham), respectively.
The APG3(+/-) mutant carries BASTA-resistance at the
APG3-disrupted allele, and a uniformly heterozygous
population can be selected as photosynthetic and
BASTA-resistant seedlings.3) The uniformly heterozygous
population facilitates investigation of the mutation
frequency in the irradiated (M1) generation by calculating
the proportion of the number of plants with white sectors ontrue leaves to that of total plants with true leaves (Fig. 1).
The AtRad54(-/-) mutant carries a kanamycin resistance. The
APG3(+/-) plants were crossed with the AtRad54(-/-) plants.
The F1 seeds were germinated in the presence of BASTA (2μg/mL) and kanamycin (50 μg/mL), and the germinatedplants were replanted to pots. F2 seeds were collected fromthe self-pollinated F1 plants. In the F2 generation, thephotosynthetic and both BASTA- and kanamycin-resistant
plants were screened. The second screening of the
APG3(+/-)/AtRad54(-/-) plants were conducted by PCR. A
sufficient number of seeds were collected from progenies of*1

RIKEN Nishina Center

the identified APG3(+/-)/AtRad54(-/-) plants.
Heavy-ion beam irradiation was conducted as previously
described3) with some modifications. The seeds of the
APG3(+/-)/AtRad54(-/-) and APG3(+/-)/AtRad54(+/+) plants were
irradiated with 12C6+ ions with LETs of 22.5 or 30.0
keVμm-1 at a dose of 300 Gy.
The mutation frequencies were obtained as previously
described.3) The mutation frequencies of AtRad54(+/+) plants
were 3.0 and 6.6% when the LET values were 22.5 and 30.0
keVμm-1, respectively, and they are significantly different(Table 1; p<0.05 with chi-square test). The mutation
frequency of 22.5 keVμm-1-irradiated AtRad54(-/-) plants
was 5.6%, which was at the same level as that of
30.0-keVμm-1 irradiated control (p≥0.05). It is assumed that
because the HRR pathway is disabled, the error-prone
NHEJ pathway mainly functioned to repair DSB. The
mutation frequency of 30.0-keVμm-1 irradiated AtRad54(-/-)
plants, however, was still 6.8%, which was at the same level
as that of the control (p≥0.05). This result proposed ahypothesis: in the case of the 30.0-keVμm-1 irradiation, in
contrast to the 22.5-keVμm-1 irradiation, DSBs occur
beyond the capacity of the HRR pathway functions and are
repaired mainly by the NHEJ pathway, leading to a highmutation frequency. Further analysis on other DNA repair
gene-deficient mutants is in progress.

Fig. 1. Sector mutation caused by heavy-ion beamirradiation on the APG3(+/-) mutant. (A) A plant showing
sector mutation. The leaf exhibiting mutation is indicatedby the white arrowhead. (B) A plant not showing abnormal
phenotype. Bars = 2 mm.
Table 1. LET-dependent effect on inducing mutation.
Mutation frequency (%)
LET (keVμm-1)
AtRad54(-/-)
AtRad54(+/+)
22.5
5.6 (916)
3.0* (2,241)30.0
6.8 (857)
6.6* (2,118)
Numbers in parentheses indicate numbers of samples.
*Kazama et al. (2012).
References

1) Y. Kazama et al.: Plant Biotechnol. 25: 113-117 (2008).
2) L. H. Thompson: Mutat. Res. 751: 158-246 (2012).
3) Y. Kazama et al.: Plant Biotechnol. 29: 441-445 (2012).

- 308 -

Ⅲ-4. Radiation Chemistry & Biology

RIKEN Accel. Prog. Rep. 48 (2015)

Characterization of isolates derived from heavy-ion-beam irradiated cells in
the unicellular green alga Parachlorella kessleri
T. Yamazaki,*1,*2 Y. Yamashita,*1 S. Ota,*1,*2 T. Takeshita,*1 Y. Kazama,*3 T. Abe,*3 and S. Kawano*1,*2
Parachlorella kessleri is a unicellular microalga relatived
to the Chlorella species that belong to the class ofTrebouxiophyceae in the Chlorophyta and accumulates
starch followed by lipids after suffering sulfur-starvation. 1)
A P. kessleri strain (NIES-2152) exhibits the highest
biomass productivity under continuous high-light
conditions among the strains that are relative algal species.
2)
The properties of P. kessleri such as the ability to produce
biomaterials including starch and lipids, and high biomass
productivity qualify this strain as the most desired candidate
in industrial production.
To improve the productivity of biomass or biomaterials inalgal cells, we have been developing a breeding system for
microalgae using P. kessleri as a model case. Our previous
report demonstrated that the isolates from heavy-ion-beamirradiated P. kessleri cells exhibit a broad spectrum ofphenotypes, which are different from the wild type strain. 3)
Another case study demonstrated that the heavy-ion-beamirradiation could disrupt gene(s) responsible for a metabolic
pathway to assimilate extracellular nitrates by transportingand oxidizing them to ammonium. 4) These findings suggestthat the breeding system based on the heavy-ion-beam will
modify a specific metabolic pathway to produce
biomaterials.
Wild type P. kesseleri cells were grown in the wells of a384-well plate using a tris-acetate-phosphate (TAP) medium
containing inorganic nutrients sufficient for healthy growthunder continuous-light conditions. Optical density at 595
nm (OD595) and the emission of a lipophilic fluorescencestain, Nile Red, in each well were measured as an index ofcell density and accumulation of neutral lipids in cells,
respectively (Fig. 1). The median of OD595 for wild type P.
kessleri cells reached to approximately 1.11 at 12th day ofculture after inoculation into a fresh TAP medium. Although
the individual values were scattered, they exhibited aconstant range of scatter in replications. The wild type cells
were grown in nutrient-limited media (dSTAP for sulfur
starvation; dNTAP for nitrogen starvation; dPTAP for
phosphorus starvation). Among the three conditions,
nitrogen starvation suppressed the increase of OD595 after
inoculation most effectively. In addition, the values inindividual wells exhibited also a constant range of scatter.
The Nile Red fluorescence values for the threenutrient-limited culture media were almost the same, andthey were higher than that for the TAP-medium, suggestingthat the neutral lipids accumulate in those cells in high and*1

Department of Integrated Biosciences, Graduate School of Frontier
Sciences, University of Tokyo*2
JST, CREST*3
RIKEN Nishina Center

Fig. 1. Boxplots of OD595 values and Nile Red emissions in replications forthe wild type strain and isolates from heavy-ion-beam irradiated P.
kessleri cells.

isolates using this method should consider the scatter
between wells.
The P. kessleri cells were irradiated by heavy-ion beams
of different doses and nuclear species (Fe and Ar ions at 25
Gy and 50 Gy). These cells were grown on plates
containing a solid TAP medium, and the obtained colonies
were defined as isolates. The individual isolates were
inoculated in the wells of 384-well plates containing a fresh
TAP medium. Four thousand six hundred and eight isolates
were grown for 12 days. OD595 values and Nile Red
emissions for these wells were measured at the 12th day ofculture after inoculation (Fig. 1). The distribution of OD595
values differed from the expected pattern with the constantrange of the scatter spreading around the median calculated
for the wild type replications. Although the exact scatter ofindividual isolates was unclear because the value wasmeasured only once, this result indicates that the population
contains heterogeneous isolates with different genetic
backgrounds. Under sulfur and phosphorus starvations, thescatters were consistent with that for the wild typereplications; however, under nitrogen starvation the median
was lower than that for the in the case of wild type. These
inconsistencies with the expected result were observed in
the constant range of scatter for Nile Red emission except in
the case of sulfur starvation. These data suggest that acertain group of isolates from heavy-ion-beam irradiatedalgal cells alters the genetic background responsible for cellproliferation and metabolism.
This study was supported by JST, CREST (to SK).
References

1) Mizuno et al. : Bioresour Technol. 129, 150–155 (2013)
2) Takeshita et al. : Bioresour Technol. 158, 127-134 (2014)3) Ota et al. : Bioresour Technol. 149, 432-438 (2013)
4) Yamazaki et al. : Riken Accel. Prog. Rep. 47, 301 (2014)- 309 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-4. Radiation Chemistry & Biology

Effects of Ar-ion beam irradiation on survival rate of Aurantiochytrium sp.
K. Ikeda,*1 R. Kose,*1 T. Okuda,*1 Y. Sakakura,*1 K. Kaya,*1 Y. Kazama,*2 and T. Abe*2

Growth rate ( hour⁻¹ ) = ln( X₁ / X₀ ) / ( t₁ - t₀ )where X₁ and X₀ are cell densities ( cells/mL ) at times t₁
and t₀, respectively. During the primary screening, 22 and12 mutants were selected from the SYLR6#3 and NB6-3
strains, respectively. However, the characteristic features ofthe selected mutants in terms of their colors and highgrowth rates completely disappeared.
The effects of other heavy-ion beams on cells are being
investigated.

150
100
50
0

40
60
Dose ( Gy )Fig.1 Survival curves of Aurantiochytrium sp.

*1*2

Sea Act Co. Ltd.
RIKEN Nishina Center

Strains

Survival rate (%) = (number of colonies) / (cellnumber before irradiation) x 100
The survival rates of both strains rapidly decreased with adose of 20 Gy (Fig.1). The colony-forming cells wereisolated from the agar plates and suspended in the sterilized
GTY medium. The cell suspension was transferred to thecell-culture plates with 96 wells for primary screening. Celldensity was measured using the iMark Microplate Reader(BIO RAD) at 650 nm. During the primary screening, basedon the colony color and a higher growth rate, mutant cells
were selected and transferred to test tubes for secondary
screening. The colonies of Aurantiochytrium with high lipid
contents showed cells also show orange to brown color.
Therefore, to select mutants with high lipid contents, darkorange to brown colonies were picked out from the various
mutated colonies.
During the secondary screening, the selected cells were
cultured in test tubes with reciprocal shaking at 25˚C for 48
h. The cell growth rate was measured using packed cellvolume (PCV, %) and was converted to cell number.
Growth rate was calculated using the following equation:SYLR6#3
NB6-3

Survival rate（％）

The organisms that belong to the Aurantiochytrium
sp. are heterotrophic marine thraustochytrids with a highgrowth rate. They produce many bioactive compounds
such as squalene, docosahexanoic acid ( DHA, C22:6n-3 ) andodd-numbered fatty acids, and they are being improved interms of their cellular cell functions for industrial
utilization1 , 2).
To introduce novel cell functions, irradiation with a swift,
heavy-ion beam to induce mutations is an effective
method3). At RIKEN RI Beam Factory (RIBF), microbial
cells and plant seeds are irradiated with heavy-ion beams
such as of carbon and argon (Ar).
In this study, Aurantiochytrium spp.NB6-3 and SYLR6#3
were selected because of their short lag times and industrial
usage. The strains were exposed to accelerated Ar ions witha dose range of 20 Gy to 80 Gy. After irradiation, cells were
cultured on GTY medium (2% glucose, 1% Tryptone, 0.5%
yeast extract and 1.8% Red Sea Salt)-containing agar plates(90mm) at 25˚C for 48 h. The colonies were counted
using the colony forming unit (CFU) to estimate theirsurvival rates and were isolated for mutant screening.
Values were expressed as averages of duplicate CFU
experiments. Survival rate was obtained using the formula:

80-49
80-36
80-26
60-56
60-48
60-46
60-44
60-43
60-42
60-41
60-13
40-54
40-53
40-50
40-39
40-30
40-21
40-20
40-17
20-32
20-14
20-7
Wild

0

20

(SYLR6#3)

0.00

80

(NB6-3)
80-45

48h
80-37
96h
80-30

48h
96h

80-22
80-21
80-14
60-51
60-50
60-37
60-24
60-7
Wild

0.05
0.10
Growth rate (hour⁻¹)

0.00

0.05
0.10
Growth rate (hour⁻¹)

Fig.2 Growth rates of isolated strains estimated during
the secondary screening
References

1) A. N. Jakobsen et al. : Appl Microbiol Biotechnol. 80 297-306(2008).
2) Q. Li et al. : Agric. Food Chem., 57, 4267-4272 (2009)3) A. Tanaka et al. : J. Radiat. Res., 51, 223-233 (2010)- 310 -

Ⅲ-4. Radiation Chemistry & Biology

RIKEN Accel. Prog. Rep. 48 (2015)

Analysis of DNA breakpoint detected fromrice exome sequencing data
R. Morita,1 K. Ishii,1 S. Kogure,1 K. Ichinose,1 Y. Hayashi,1 and T. Abe1
We have performed exome sequencing analysis to reveal
mutations induced by heavy-ion beams in rice. We used
three software packages, GATK, Pindel, and BEDTools, todetect mutations from exome sequencing data. Among them,Pindel finds DNA breakpoints, decides the types ofmutations such as deletion, insertion, inversion, and tandem
duplication1). When Pindel cannot determine types ofmutations, the mutation is called an "unassigned
breakpoint". We found homozygous mutations called
unassigned breakpoints from the rice mutant (Mutant-1)
induced by Ne-ion beam irradiation. This mutant possessed
three unassigned breakpoints. Two of these were located in
the same chromosome, suggesting that they werebreakpoints derived from an inversion.
We confirmed the candidate inversion by polymerase
chain reaction (PCR) analysis. First, we estimated theposition of two breakpoints, namely, breakpoint A andbreakpoint B by using Integrative Genomic viewer2). Then,
we designed primer F1 having the sequences in the
upstream region of the breakpoint A (Fig. 1). We createdprimer R1 corresponding to the downstream region of thisbreakpoint. Similarly, primers F2 and R2 were synthesized
on both sides of the breakpoint B. When PCR was carriedout with primer sets F1R1 or F2R2 using wild-type
genomic DNA as the template, DNA amplification wasobserved (Fig. 1). On the other hand, when PCR was
carried out using Mutant-1 DNA as the template, noamplification of these DNA fragments should be observed(Fig. 1). When we attempted to amplify a DNA fragmentwith primer sets F1F2 and R1R2 using Mutant-1 DNA,DNA amplification should be observed (Fig. 1).

Fig. 1. Experimental design for detecting an inversion by
PCR. Bold arrows indicate the annealing site of each primer.
Thin arrows indicate the direction of the DNA. Boxes
indicate chromosome.
1

RIKEN Nishina Center

We investigated the existence of the inversion from DNA
amplification pattern in this way.
In the PCR experiment, DNA amplification was observed
when we used primer sets F1F2 or R1R2 using mutant 1
genomic DNA as the template (Fig. 2). No amplification ofthese DNA fragments was observed when we usedwild-type DNA as the template (Fig. 2). These results
demonstrated that homozygous inversion existed in the
Mutant-1 plant as we expected. Sequencing analysis using
PCR products of the Mutant-1 plant revealed that 2-bp
deletion occurred at breakpoint A and 5-bp deletionoccurred at breakpoint B (Fig. 3). The distance frombreakpoint A to B was 298.6 kb, and we found a new
mutant gene disrupted by breakpoint B (Fig. 3). Ourfindings suggest that we can identify new mutated genefrom a mutation that is called an "unassigned breakpoint"
by using Pindel. PCR analysis of "unassigned breakpoint"mutations generated in other mutants is in progress.

Fig. 2. Detecting an inversion generated in mutant-1. DNA
amplification is detected by MCE-202 MultiNA (Shimadzu).
The names of the genomic DNAs and primers are displayed
above the gel image. DNA size markers are shown on theleft side.

Fig. 3. Structure of inversion determined in this study. Thin
arrows indicate the direction of the DNA. The genedisrupted by the inversion is shown as the yellow box.
References

1) K. Ye et al.: Bioinformatics. 25, 2865 (2009).
2) J. T. Robinson et al.: Nature Genet. 29, 24 (2011).

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Ⅲ-4. Radiation Chemistry & Biology

Establishment of rice transformation systems
to study gene functions
R. Morita,＊1 K. Ichinose,＊1 Y. Shirakawa,＊1 and T. Abe＊1
We have screened a large number of rice mutants
induced by heavy-ion beam. To identify the causal gene foreach mutant, a complementation test is needed. The
complementation test is the experiment used to determine
whether a gene is a causal gene for a mutant. The Recovery
of a specific phenotype of a mutant is observed when an
intact causal gene is introduced to a mutant (Fig. 1).1) To
clarify the causal gene for the rice mutant of interest, weused a reliable Agrobacterium-mediated transformation
system.2, 3) In the Agrobacterium-mediated method, a DNA
region termed "T-DNA" transfers from a circular DNA in
Agrobacterium into plant chromosomes (Fig. 2). We
introduce both the gene of interest and the marker gene fora selection reagent, such as antibiotics or herbicides, into
the T-DNA region. Plant cells that have accepted T-DNA
will only survive on a medium containing a selection
reagent. The Agrobacterium-mediated method is a goodmeans to obtain a transgenic plant with high efficiency anda low copy number.
For a pilot experiment, we introduced the hygromycin
phosphotransferase (HPT) gene in rice. The HPT geneconfers hygromycin-resistance to rice cells and is one of themost frequently used marker gene in transformation
experiments of rice. We obtained more than 20 plantlets
from the calluses induced from 100 rice seeds (Fig. 3).

Fig. 1. Complementation test performed in the study of arice virescent mutant. The virescent mutant generates whiteleaves when they are grown at 20 oC (left). Mutant plantsthat contain T-DNA including the intact causal gene show
green leaves under the same condition (right). Rice plants
are grown in the Murashige and Skoog medium. Bar = 1
cm.
＊1

The transformation efficiency of our experiment (over 20%)
was equivalent to the efficiency reported by Toki et al.
(2006). Using this technique, we will determine the causal
gene for a rice mutant exhibiting an interesting phenotype.

Fig.
2.
Schematic
representationofAgrobacterium-mediated plant transformation system.

theFig. 3. Regenerated plant from the hygromycin-resistantcallus. Bar = 1 cm.
References

1) R. Morita et al.: RIKEN Accel. Prog. Rep. 46, 259 (2013)2) S. Toki et al.: Plant J. 47, 969 (2006)
3) H. Saika et al.: Transgenic Plants: Methods and Protocols 3, 67(2012)RIKEN Nishina Center- 312 -

Ⅲ-4. Radiation Chemistry & Biology

RIKEN Accel. Prog. Rep. 48 (2015)

Functional analysis of a new virescent mutant in rice induced byheavy-ion beam irradiation
H. Abe,＊1 R. Morita,＊1 S. Kogure,＊1 K. Ichinose,＊1 Y. Hayashi,＊1 and T. Abe＊1
It is evident that heavy-ion beam irradiation effectively
produced many phenotypic mutants in rice (Oryza sativa L.
cv. Nipponbare)1, 2); thus, the method has been applied torice breeding as a new technology. Although many ricemutants have been isolated to date, the functions of anumber of their causative genes have not been completely
elucidated. One such mutant, 22-4Y in rice, has beenobtained as a virescent mutant by irradiating seeds with acarbon-ion beam (20 Gy, LET: 22.5 keV/µm)3). virescentis a chlorotic mutant of higher plants that reduces thechlorophyll content in young leaves, but the chlorophyll
content of the leaves recover as the plants grow4). Certainclasses of the virescent mutants are low-temperature
conditional4); the 22-4Y mutant also shows chlorotic leaves
phenotype when grown at 20 ○C but not at 30 ○C during theearly growth stages3). As the 22-4Y functions are relatedwith chlorophyll synthesis and/or chloroplast development,
both of which are important for crop production, we
decided to investigate the 22-4Y gene and to analyze its
functions.

Fig. 1. Schematic representation of the 22-4Y protein andits fragments expressed in E. coli.
The predicted 22-4Y protein (the upper line) has 720
amino acids (M1-Y720) with a calculated molecular massof 78.2 kDa.
Each fragment of 22-4Y(C58-Y720),(C58-R417), (D418-Y720), (C58-P239) and (R240-R417)
is shown. Positions of the FAD/NAD(P)-binding motif(GXGXXG) are shown in red bars. A region withhomology to pyridine nucleotide-disulfide oxidoreductase
family enzymes is shown in green.
The predictedchloroplast transit peptide is shown in dark blue.
＊1

Genetic analysis of the 22-4Y mutant revealed that gene
LOC_Os05g34040 on the long arm of chromosome 5
showed a deletion of 13095 bp 3). Morita et al.3) confirmed
by using a genetic complementation test that the causative
gene of 22-4Y is LOC_05g34040.
In order to know the gene functions, in many cases, it ismost important and necessary to reveal the functions of theprotein encoding to the corresponding gene. BLAST
searches of the complete Oryza sativa sequence revealed
that only one copy of the 22-4Y gene is present in the
nuclear genome, which encodes a putative polypeptide of
720 amino acids with a calculated molecular mass of 78.2
kDa (Fig.1, the upper line). Pfam search predicted that the
22-4Y
proteinhadaputative
conserved
FAD/NAD(P)-binding motif (GXGXXG) (Fig.1, red bars)
and a homology to pyridine nucleotide-disulfide
oxidoreductase family enzymes (Fig1, green region). Thismeans that 22-4Y is a new class of VIRECENT protein
among so far identified4) (V1, chloroplast-localized RNAbinding protein; V2, guanylate kinase; V3, large subunit ofribonucleotide reductase). TargetP program predicted that
the N-terminal 57 amino acids sequence of the 22-4Y
protein was a chloroplast transit peptide. Actually, when
the N-terminal 76 amino acids sequence of the 22-4Y
protein was fused to cyan fluorescent protein (CFP) andtransiently expressed in an onion epidermal cell, the fusion
protein was localized to chloroplast. Thus, the N-terminal
sequence of the 22-4Y protein was functional as achloroplast targeting peptide.
Electron microscopic
observation revealed that chloroplast development wasarrested when 22-4Y mutant was grown at 20 ○C but not at
30 ○C during the early growth stages. These results
suggest that the 22-4Y protein was functional in chloroplastand had some important regulatory functions in chloroplastdevelopment.
To further reveal and analyze the protein function of
22-4Y, we decided to purify some recombinant proteins of
22-4Y by using an E. coli expression system (Fig. 1). It is
important to demonstrate the enzymatic activity of the
22-4Y protein, as well as to identify the target (substrate)
protein(s) to reveal the regulatory functions of the 22-4Y
protein during chloroplast development.
References

1) Y. Hayashi et al.: RIKEN Accel. Prog. Rep. 43, 282 (2010).
2) Y. Hayashi et al.: RIKEN Accel. Prog. Rep. 46, xxiv (2013).
3) R. Morita et al.: RIKEN Accel. Prog. Rep. 46, 259 (2013).
4) K. Kusumi and K. Iba: Front Plant Sci. 5, 386 (2014).

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Ⅲ-4. Radiation Chemistry & Biology

Tracking alleles linked with Fusarium head blight resistance QTLs in wheat(Triticum aestivum) released in Kyushu region
S. Niwa,＊1,＊2 Y. Kazama,＊1,＊2 M. Alagu,＊2 T. Abe,＊1 and T. Ban＊2
Fusarium head blight (FHB) is a plant diseaseoccuring insmall grains such as wheat, barley and maize. In Japan, the
FHB of wheat is one of the most destructive diseases
because of its coincidence with the flowering to
grain-filling period of wheat which provides afungus-favorable condition. In addition, FHB decreases theyield and the quality of wheat.
The Kyushu region is one of the main wheat production
areas in Japan. After the FHB epidemics in 1963, anintensive breeding program for FHB resistance has been
conducted in Kyushu as a national breeding program.
Similar to the general breeding program, FHB resistancebreeding has been performed by crossing a cultivar ofinterest with another resistant cultivar. Then, progenies
having appropriate traits are selected. Through this process,feasible alleles (feasible one of a number of alternative
forms of the same gene) would be selected, which implies
that the alleles linked to loci related to an unfavorable
agronomic trait may also be excluded. Because of theannual variation in rainfall, FHB disease pressure fluctuates,
causing rendering the evaluation of FHB resistance lines
laborious and uncertain. By investigating the alleles related
to the FHB resistance through the breeding linage,
information on alleles contributing to the FHB resistance inthe breeding program can be obtained.
As a first step, thirteen representative cultivars bred from
1920s to 2010s were selected. The seeds of the cultivars
were sown on petri dishes and refrigerated at 4°C for fourdays; subsequently, they were germinated in a 25°C
chamber. The germinated plantlets were transplanted to pots
and grown in a glasshouse at 25°C. Leaves were harvested
18 days after sowing and used for DNA extraction.

Of the 21 wheat chromosomes, DNA markers linked to thealleles related to FHB resistance were reported in the shortarm of chromosomes 2D (2DS), long arm of 2D (2DL),
3BS, 5AS, and 6BS.1-4) By conducting PCR using thesemarkers, types of alleles related to FHB resistance (resistant,susceptible, or other) in individual cultivars were
determined. The fragment, after amplification with a DNA
marker UMN10 at 3BS was analyzed by sequencing. The
PCR products of the other markers were electrophoresedusing MultiNA (Shimadzu, Kyoto, Japan).
The results are listed in Table 1. Resistant alleles on 3BS
and 5AS were retained after ‘Shinchunaga’ was bred. The
resistant allele on 2DL was fixed in the linage after‘Asakazekomugi’ was bred. In contrast, resistant alleles on
2DS and 6BS were excluded from the lineage for cultivars
released after the 1940s released cultivars, when
‘Shinchunaga’ had contributed as their frequent crossing
parent. Interestingly, the susceptible alleles from
‘Shinchunaga’ had been selected for 2DS, and the resistancealleles on 6BS were selected alternatively from the counter
parents of ‘Shinchunaga.’ It can be expected that somealleles responsible for unfavorable agronomic trait(s) on
6BS from ‘Shinchunaga’ may be linked to these regions.
‘Shinchunaga’ has favorable allele (s) such as rht8
thatdetermins plant height and was selected even linked
with the susceptible allele for FHB. In the same manner,other alleles detected in modern cultivars might contribute
to FHB resistance rather than the ones detected in oldcultivars as new linkage disequilibrium. Further
investigation of the alleles related to FHB resistance inevery generation of lineages is in progress.

Table1 Types of FHB resistance-related alleles in Kyushu linages
5AS
6BS
Release
2DS
2DL
3BS
year
Cultivar
TaMRP-D1 Xgwm539
UMN10
Xgwm293 Xgwm304 Xwmc398 Xgwm644
1923
Eshimashinriki
R
o
o
R
R
nd
nd
1931
Norin 5
R
R
o
R
R
o
R
1933
Shinchunaga
S
o
R
R
R
R
R
1936
Norin 20
R
o
R
R
R
R
R
1943
Norin 52
S
o
R
R
R
o
o
1956
Shirasagikomugi
S
o
R
o
S
o
o
1957
Junreikomugi
S
o
R
R
R
o
o
1978
Asakazekomugi
S
R
R
R
R
o
o
1986
Wheat Norin PL-4
S
R
R
R
R
R
nd
1986
Saikai 165
S
R
R
R
R
o
o
1994
Chikugoizumi
S
R
R
R
S
o
o
2006
Towaizumi
S
R
R
nd
R
o
o
2011
Wheat Norin PL-9
S
R
R
o
S
o
o
R: resistant allele, S: susceptible allele, o: other allele (resistant type unknown), nd: not determined

References＊1＊2

RIKEN Nishina Center
Kihara Institute for Biological Research, Yokohama City University

1) P. Cuthbert et al.: Theor. Appl. Genet. 114: 429 (2007).
2) S. Liu et al.: Cereal Res. Commun. 36: 195 (2008).
3) H. Buerstmayr et al.: Plant Breed. 128: 1 (2009).
4) T. Suzuki et al.: Breed Sci. 62: 11 (2012).

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RIKEN Accel. Prog. Rep. 48 (2015)

Ion track observation in cell nucleus irradiated by 3 MeV He ion microbeams
produced with glass capillaries
T. Ikeda,＊1 M. Izumi,＊1 V. Mäckel,＊2 T. Kobayashi,＊2 R. J. Bereczky,＊1 T. Hirano,＊1 Y. Yamazaki,＊2 and T. Abe＊1
Microbeam irradiation of cultured single cells using
tapered glass capillaries with outlet diameters of the orderof 1 m has been performed employing RIKEN Pelletron
accelerator. Apparatus with a 3-m outlet diameter isreported in elsewhere1). Microbeam is a unique scheme 2)that can actively select an irradiation volume of ~m3.
When a microbeam of He ions of a few MeV hits a target,e.g., a biological cell, the ions will stop at the depth
corresponding to their range (10~20 m). Any other parts
downstream of the stopping volume will not be damaged.
This is one of advantages of employing beams of a few
MeV. The glass capillaries with thin end-windows play animportant role in delivering the ions directly to the cells insolution.
At RIKEN, we have developed a unique technology formutation breeding using high-energy heavy-ion beams fromRIKEN Ring Cyclotron. Such high linear energy transfer(LET) ions produce clustered DNA damage that cannot be
repaired by the cell itself, leading to cell death, or can only
be repaired incompletely by the cell, which induces
mutations. In order to investigate both the lethality and theeffectiveness of mutation induction, the position selectivityof the microbeam will be needed because hitting ofdifferent parts may cause unwanted effect. Here wedemonstrate the DNA damages along ion tracks in a cell
nucleus using a microbeam with relatively high LET.
A 3-MeV He ion microbeam was used for the irradiationof the nucleus of human cells (HeLa cells) because it is
known that there is a similarity in the radiation response
between plant and animal cells. The ions were generated by
the Pelletron and transported to the cell irradiation port1). A
5-cm-long glass capillary optics with a 4-m-thickend-window whose diameter was 3 m and with an inlet
diameter of 0.8 mm was installed at the beam port with anangle of 45o with respect to the horizontal plane so thatwidely-used petri dish filled with liquid solution can beused. The LET of a 3-MeV He ion is 150 keV/m in water.
The range of the ions is only 12 m in water after theend-window. In order to adjust the dose of the irradiation toeach cell, a beam chopper consisting of an electrostatic
beam deflector was employed so that a few to ten ions were
included in a short pulse of 0.8 s. The pulse was repeated100-1000 times according to the number of the required
ions to the target.
It took approximately 12 min to irradiate about 40 cells in
one dish, and totally 168 cells in 4 dishes were irradiated.

After the irradiation, the Double Strand Breaks (DSBs) at
DNAs were fluorescent-labeled as follows. The time for the
repair process based on an enzymatic reaction was 20 min
after the irradiation, and then the cells were washed threetimes with ice-cold phosphate-buffered saline (PBS) and
fixed with 4% formaldehyde in PBS at 4°C for 20 min.
Then, the cells were permeabilized with 0.5% Nonidet P-40
in PBS at 4°C for 5 min, and phosphorylated histone H2AX
was detected by using rabbit antibody (Millipore) and an
Alexa488-conjugated donkey anti-rabbit IgG (Jackson
ImmunoResearch Laboratories).
Figures 1(a) and (b) are the cross-sectional and bottom
views of the irradiated cells, respectively, reconstructedfrom the photos taken by changing the focus position along
the z-axis (vertical axis). Cell nuclei are identified as
bean-shaped blue regions with a width of ~15 m and havefluorescence from a stain DAPI binding to A-T rich regionsin DNA. The outlines of the cells are not seen. The DSBs
are detected as bright points with green color from
Alexa488. Even without irradiation, DSBs can take place asan activity of a living cell. However, the concentration of
DSB bright points along a line is an evidence of artificial
lesion. The ion track with the angle of 45o is clearly seen as
a fluorescent line in Fig. 1(a). We succeeded in observationof a visible track for MeV ions inside a cell nucleus. It is
confirmed that MeV-ion irradiation made DSB lesions in
the DNA, which may cause gene defects. Further
experiments considering other conditions, e.g., LET, control
of cell cycle, and so on are needed as well as the number ofions necessary to form a track.

Fig. 1. Fluorescent lines corresponding to the ion track in ahuman cell nucleus. (a) Cross-sectional view of theirradiated cells at the horizontal line in the bottom view. (b)Bottom view of the cell.
References

RIKEN Nishina Center＊2
Atomic Physics Laboratory, RIKEN＊11) V. Mäckel et al.: Rev. Sci. Instrum. 85, 014302 (2014).
2) Y. Iwai et al.: Appl. Phys. Lett. 92, 023509 (2008).

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Ⅲ-4. Radiation Chemistry & Biology

Estimation method of microbeam divergence from glass capillaries forbiological use
R.J. Bereczky,＊1 T. Ikeda,＊1 T. Kobayashi,＊2 M. Utsugi,＊3,＊1 T. Hirano,＊4,＊1 Y. Sakai,＊3 and T. Abe＊1
Ion microbeams can be used in various fields such as basic
research, or for many different technical applications suchas in radiobiology. When an ion beam with energy on theorder of megaelectron volts is transmitted through a tapered
glass microcapillary, the extracted beam can be used as aion microbeam for cell irradiation. Moreover, the ions canbe directly guided to the cell using a capillary with athin-end window. At RIKEN, we have developed a unique
technology for mutation breeding using high-energy
heavy-ion beams. Heavy-ion beams at relatively low doses
induce mutations at a high rate without severely inhibiting
growth. Densely ionizing radiation produces clusters of
DNA damage that cannot be repaired by the cell, leading tocell death, or can only be repaired incompletely by the cell,which induces mutations. The effects of heavy-ion beams
on both the lethality and effectiveness of mutation induction
should be investigated in more detail in future studies. An
ion microbeam is a useful tool for DNA damage or repair
process research. The regions relevant to mutations in aliving cell are not distributed uniformly, but concentrated
into a small region. A well-defined microbeam is required toirradiate these small regions.
The purpose of our work is the development of
microbeam irradiation for human cells, in which it is easy toobserve DNA damages. Through these investigations, we
provide an estimation method to define the beam
divergence in a tapered glass capillary. Our studies havebeen performed both experimentally and theoretically. In
the case of thinner capillaries, i.e., on the order of 1 micron,the divergence of the transmitted beam has been
investigated, and similar experiments with a 200 μm
diameter capillary without a thin end-window were also
reported1). No study has yet reported on capillaries withoutlet diameters in the 10 μm range and with thin
end-windows, a size at which the application for cellirradiation is not obvious anymore.
The result of our first SRIM simulations2) showeddiscrepancy from the experimental ones (see procedure
below). When we changed the divergence of the beam
inside the capillary from 0 to a nonzero value, i.e, 2.5°, theresults of the simulation and the experiment were in good
agreement (Fig. 1).
We measured the beam distribution extracted in air as afunction of the distance between the exit of the capillary
and a piece of CR-39, using He ions with the energy of 4.5
MeV produced by the RIKEN pelletron accelerator.
RIKEN Nishina Center
Atomic Physics Laboratory, RIKEN＊3
Toho University, Department of Physics＊4
University of Miyazaki, Faculty of Agriculture＊1＊2

The ions were transmitted through a tapered glass capillary(pulled from injection needle), set at the end of the beamline.
The inlet diameter of the capillary was 800 μm, the outlet
diameter was 4 μm, and it had a thin end-window made ofplastic with a thickness of 8 μm3). The length of thecapillary was ~ 65 mm. The profile of the extracted beam
was measured with CR-39 (Fig. 2). The average rate of theions was 14 counts/s during the measurement. To avoid theoverlap of the ion tracks on the CR-39 surface, the numberof transmitted ions was chosen once as 200, and as 600 in
the other cases.
Further systematic studies will be performed in the near
future that will contribute to the development of microbeam
irradiation of human cells.

Fig.1. Comparison of the beam profile of the experiments(black) and SRIM simulations (orange). The horizontal
axis shows the distance of the ion tracks from the center ofthe beam. The values of the beam divergence inside thecapillary are shown in each figures. The distance between
the exit of the capillary and the CR-39 was 6 mm.

Fig.2. Profile of the extracted beam, when the distance
between the exit of the capillary and the CR-39 was 2 mm.
The scale corresponds to 50 μm.
References
1) N. Fujita et al.: NIMB 315, 332-335 (2013).
2) SRIM-2013: http://www.srim.org/.
3) Y. Iwai et al.: Appl. Phys. Lett. 92, 023509 (2008).

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RIKEN Accel. Prog. Rep. 48 (2015)


＊＊＊＊＊＊＊        

       
        
                      
      
     
       
    

     


        
      
      
      

             
                R  T     

      R T 
 
          
       
     R   
         


       
          
       
    R     

＊ 
 ＊ ＊ ＊ ＊ 
         δR      
       
                
          
         
             
       
                   



       
       
                
 

 
   

















     R   





- 317 -

IV. OPERATION RECORDS

Ⅳ. OPERATION RECORDS

RIKEN Accel. Prog. Rep. 48 (2015)

Program Advisory Committee meetings
for nuclear physics and for material and life science
K. Yoneda, ∗1 K. Ishida, ∗1 H. Yamazaki, ∗1 N. Imai, ∗2 K. Yako, ∗2 H. Ueno, ∗1 and H. Sakai∗1
The Program Advisory Committees (PAC) is incharge of reviewing scientific proposals submitted foruse of the accelerator facility of RIKEN Nishina Center (RNC). In Fiscal Year 2014, three PAC meetings
were held; two for proposals of nuclear physics (NPPAC), and one for proposals of material and life science(ML-PAC). The NP-PAC meetings were co-organizedby RNC and the Center for Nuclear Study (CNS), theUniversity of Tokyo. The NP-PAC reviewed experimental proposals at RIBF, whereas the ML-PAC reviewed proposals at Rutherford Appleton Laboratory(RAL) and RIBF.

Table 1. Summary of the outcome of the 14th and 15th
NP-PAC meetings. The proposals ranked with S and A
are treated as the “approved” proposals.
14th NP-PAC (June 27 – 28, 2014)
requested
approved
proposals (days) proposals (days)
GARIS (RILAC)
1 (26)
1 (26)
CRIB (AVF)
3 (37)
1 (18)
RIPS (RRC)
3 (38)
3 (16.5)
BigRIPS/ZDS
9 (88)
3 (20.5)
SHARAQ
1 (5.5)0 (0)SAMURAI
6 (50.5)
3 (21)
Construction
0 (-)
0 (-)
Total
23 (245)
11 (102)

NP-PACThe 14th and 15th NP-PAC meetings were held on
June 27 and 28, 2014, and December 12 and 13, 2014,
respectively1) . In the 14th (15th) NP-PAC meeting,23 (20) proposals were reviewed, and 11 (14) proposals
were approved as grade S or A. The outcome of these
NP-PAC meetings is summarized in Table 1.
Before the 14th NP-PAC meeting, one of the PAC
members resigned, and no new member was added.
Consequently, the number of the PAC members became sixteen.
The PAC members of the 14th and 15th NP-PAC
meetings are as follows:
M.N. Harakeh (KVI, the chair), R.F. Casten (Yale
Univ.), H. Emling (GSI), H. Iwasaki (Michigan State
Univ.), W. Loveland (Oregon State Univ.), S. Nakamura (Tohoku Univ.), T. Nakatsukasa (RNC), T. Nilsson (Chalmers Univ.
of Technology), C. Scheidenberger (GSI), B. Sherrill (FRIB Lab.), O. Sorlin (GANIL), A. Tamii (RCNP, Osaka Univ.), F.K. Thielemann (Univ. of Basel), Y. Utsuno (JAEA),
M. Yahiro (Kyushu Univ.), and Y. Ye (Peking Univ.).

ML-PACThe 11th ML-PAC meeting was held on January 8
and 9, 20152) . In this meeting, 31 RAL proposals and8 RIBF proposals were reviewed. The summary of theoutcome of the meeting is given in Table 2.
The 11th ML-PAC members are as follows:
J.-M. Poutissou (TRIUMF, the chair), A. Amato (PSI), T. Azuma (RIKEN), A. Hiller (ISIS,
RAL), R. Kadono (KEK), A. Kawamoto (Hokkaido
Univ.), N. Kojima (Univ.
of Tokyo), K. Kubo
∗1
∗2

15th NP-PAC (December 12 – 13, 2014)
requested
approved
proposals (days) proposals (days)
GARIS (RILAC)
0 (0)
0 (0)
CRIB (AVF)
3 (19.333)
3 (19.333)
RIPS (RRC)
0 (0)
0 (0)
BigRIPS/ZDS
12 (91.5)
7 (34)
SHARAQ0 (0)0 (0)SAMURAI
5 (40.5)
4 (12.5)
Construction
0 (-)
0 (-)
Total
20 (151.333)
14 (65.833)

Table 2. Summary of the outcome of the 11th ML-PAC
meeting.
11th ML-PAC (January 8 – 9, 2015)
requested
approved
proposals (days) proposals (days)
RAL
31 (208)30 (123)RIBF
8 (66)
7 (50)Total
39 (274)
37 (173)(ICU), D.E. MacLaughlin (UC Riverside), S. Maekawa(JAEA), P. Mendels (Univ. Paris, Orsay), H. Yamase(NIMS), S. Yoshida (Thera Projects Associates), andX.G. Zheng (Saga Univ.).
References
1) http://www.nishina.riken.jp/RIBF/NP-PAC/index.html
2) http://www.nishina.riken.jp/RIBF/ML-PAC/index.html

RIKEN Nishina Center
Center for Nuclear Study, the University of Tokyo- 319 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅳ. OPERATION RECORDS

Beam-time statistics of RIBF experiments
K. Yoneda,∗1 H. Ueno,∗1 and H. Sakai∗1∗1

RIKEN Nishina Center- 320 -

100

Machine Study

90

User Time

Beam Time (days)

80
70
60
50
40
30
20
10
0

2007 2008 2009 2010 2011 2012 2013 2014

Fiscal Year

Fig. 1. Bar chart showing the BT statistics for high-energymode experiments from FY2007 to FY2014. The accelerator tuning time and Nishina Center mission time are
not included.
300

RILAC stand alone
AVF stand alone

250

Beam Time (days)

This report describes the statistics of the beam times(BTs) at the RIBF facility in Fiscal Year (FY) 2014. In
the following, the BTs are categorized into two groups:
high-energy-mode and low-energy-mode BTs. In theformer mode, the beams were delivered in the acceleration scheme of AVF, RILAC, or RILAC2 → RRC →(fRC → IRC →) SRC, where the accelerators in parentheses can be skipped in the cascade acceleration, depending on the beam species used. In the latter mode,
the acceleration scheme is AVF or RILAC (→ RRC).
BTs in the high-energy mode were scheduled from
April to July, from October to December 2014, andin the latter half of March 2015, considering the restriction of utility-power use, budgetary constraints,
maintenance schedule of the accelerator system andco-generation system, as well as other constraints. In
the series of experiments in spring, the primary beams
of 238 U, 70 Zn, 2 H, and 16 O were provided to users, andin the autumn series, the primary beams of 238 U and48
Ca were provided. The beam time in March 2015 wasused only for the nuclear transmutation program which
was carried out as a Nishina Center mission program,i.e. as an experiment other than what the RIBF Program Advisory Committees1) (PAC) was approved. 13
experiments approved by the PAC with the approved
beam time of 70.4 days were conducted in total. 7.3
days were used for the facility development programs,
defined as machine study (MS) experiments. Other
than these, three new isotope search experiments andtwo transmutation experiments were conducted as the
Nishina Center mission programs.
The data summary of the high-energy-mode BTs in
FY2014 is given in Fig. 1 as a bar chart. Compared tothe beam time in FY2013, the user time increased, as
the beam time operation in FY2013 was in spring only.
Including the Nishina Center mission beam time, thetotal amount of beam time available in FY2014 wasrecovered to the level of FY2012.
The data summary for the low-energy mode is shownin Fig. 2. Here the BTs are classified by the accelerator
operation modes, AVF, RILAC, and RRC. In FY2014,
most of the low-energy-mode experiments after December had to be cancelled, due to the restriction of the operation budget. Despite of this cancellation, the total
amount was almost the same as in FY2013. The fraction of the RILAC stand-alone beam time increased,
as a long experiment approved as the S grade was conducted.

RRC
200
150
100
50
0
2007 2008 2009 2010 2011 2012 2013 2014

Fiscal Year

Fig. 2. Bar chart showing the BT statistics for low-energymode experiments from FY2007 to FY2014.

References
1) K. Yoneda, K. Ishida, H. Yamazaki, N. Imai, K. Yako,
H. Ueno, and H. Sakai: In this report.

Ⅳ. OPERATION RECORDS

RIKEN Accel. Prog. Rep. 48 (2015)

Operation report of the industrial cooperation teamA. Yoshida,∗1 T. Kambara,∗1 H. Takeichi,∗1 H. Haba,∗1 S. Shibata,∗1 K. Takahashi,∗1 S. Yanou,∗2 andY. Wakitani∗2
In 2014, the industrial cooperation team was engaged in collaboration research for industrial application of RI beam, fee-based utilization of heavy-ion
beams to industry, and fee-based distribution of radioisotopes. These activities are summarized below.
Under a collaborative research agreement entitled “Development and application of wear diagnosis
method with RI beams” between RIKEN, Universityof Tokyo, and two private companies, we develop amethod for wear diagnostics of industrial materials using RI beams as tracers. Compared with conventional
methods where tracer RIs are produced in the materials by ion-beam irradiations, our method employs RIbeam implantation for the materials, which results inless radiation damage in the materials. We had two
beamtimes, IC13-01-01 in February and IC13-01-02 in
March 2014, at E7A beamline of the AVF cyclotron.
Beams of RI nuclei 7 Be (T1/2 = 53 days) with intensities up to 108 ions/s and 22 Na (T1/2 = 2.6 years) withintensities up to 107 ions/s were provided by CNS RI
beam separator (CRIB) and implanted near the surfaceof metallic machine parts, whose wear-loss was evaluated through radioactivity measurements. Anotherarticle in this report describes technical details on the
preparation and characterization of the RI beams.1)
Concerning this research, two patents have been applied for.2)
RIKEN Nishina Center opened the AVF cyclotron,
RILAC, and RIKEN Ring Cyclotron (RRC) for industrial utilizations.3) The first proposal of fee-based utilization was submitted by private companies in June
and was reviewed and approved by the Industrial Program Advisory Committee (InPAC) in August (proposal number IC14-01). The beamtime was performedin October with a 70-MeV/A 84 Kr beam at the E5A
beamline of the RIKEN Ring Cyclotron. Another article in this report describes technical details of the beam
preparation and characterization according to the customers’ requests.4)
Since 2007, RIKEN distributes radioisotopes (RIs)
produced at RIBF to users in Japan for a fee incollaboration with the Japan Radioisotope Association5) (JRIA). According to a material transfer
agreement (MTA) drawn between JRIA and RIKEN,
JRIA mediates the transaction of the RIs and distributes them to users. The distributed RIs are 65 Zn(T1/2 = 244 days), 109 Cd (T1/2 = 463 days), and 88 Y
(T1/2 = 107 days). The RIs are produced by the
RI Applications Team at the AVF cyclotron. 65 Zn,∗1∗2

RIKEN Nishina Center
Japan Radioisotope Association- 321 -

Cd, and 88 Y are produced with a 24-MeV deuteronbeam through 65 Cu(d,2n)65 Zn, 109 Ag(d,2n)109 Cd, andnat Sr(d,xn)88 Y reactions, respectively.
In 2014, we delivered three shipments of 109 Cd witha total activity of 22 MBq, seven shipments of 65 Zn
with a total activity of 44 MBq, and one shipment of88
Y with an activity of 1 MBq. The final recipients of
the RIs were five universities, one research institute,and two hospitals. Figure 1 shows the yearly trends
in the number of orders and the amounts of the distributed RIs.
109

Fig. 1. Number of orders (left) and amount (right) of theRIs distributed yearly from 2007 to 2014. The distribution of 88 Y started in 2010.

Information on the RIs can be obtained from
JRIA through their dedicated website (https://www.jram.net/jram/DispatchTopPage.do; in Japanese) or
FAX (03-5395-8055).
References
1) A. Yoshida et al.: in this report.
2) A. Yoshida et al.: Japanese Patent No. 2014-4555 and
T. Kambara, A. Yoshida and H. Takeichi: Japanese
Patent No. 2014-34417.
3) http://ribf.riken.jp/sisetu-kyoyo/ (Japanese).
4) T. Kambara et al.: in this report.
5) http://www.jrias.or.jp/ (Japanese),
http://www.jrias.or.jp/e/ (English).

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅳ. OPERATION RECORDS

Electric power condition of Wako campus in 2014
E. Ikezawa, *1 M. Kato, *1 H. Yamazawa, *1 and M. Kase*1
The monthly electrical power consumption data for RIKEN
Wako campus (Wako) and RIKEN Nishina Center (RNC),
and the energy supply by the cogeneration systems (CGSs)
are shown in Fig. 1. The hourly average electrical power
consumption at RNC for each day in 2014 is shown in Fig. 2.
The annual data of electrical power consumption and energy
supply in 2014 is listed in Table 1. The total electrical power
consumption of Wako in 2014 was 157,943 MWh, which
was 10% higher than that in 2013. On the other hand, thetotal electrical power consumption of RNC in 2014 was
72,724 MWh, which was 30% higher than that in 2013.
When the RI Beam Factory (RIBF) experiments using theuranium (238U) beam were conducted, the maximum
electrical power supply to Wako from Tokyo electric power
corporation (TEPCO) reached 22.0 MW with a CGS output
of 3.5 MW on April 9, 2014, whereas the maximum
electrical power consumption of RNC reached 17.1 MW on
October 21, 2014.
A complete overhaul of the gas turbine of the CGS #1 after
8,000 h of operation was carried out in September 2014.
We experienced the following problems during thereporting period. The CGS #1 stopped on May 25, 2014, andagain, on October 21, 2014, because of control equipment
failure. We had an interruption in power supply on February
15, 2014, due to a snow storm. Earth leakages also occurred
9 times. However, the origin of most of those leakages were
unexplained.

Fig.1 Monthly electrical power consumption and energy
supply by CGSs in 2014.

Fig.2 Hourly average electrical power consumption at RNC
for each day in 2014.

Table 1 Annual data of electrical power consumption andenergy supply in 2014.
Total

Unit

Wako purchase

139,851

MWh

Total electrical power supply to Wako from TEPCO

111%

Wako consumption

157,943

MWh

Wako electrical power consumption (CGSs + TEPCO)110%

RNC purchase59,319MWh

Total electrical power supply to RNC from TEPCO

137%

CGS #1

13,405

MWh

CGS #1 total electrical power output

107%

RNC consumption

72,724MWh

RNC total electrical power consumption

130%

＊1

Note

RIKEN Nishina Center- 322 -

% of 2013

Ⅳ. OPERATION RECORDS

RIKEN Accel. Prog. Rep. 48 (2015)

Radiation safety management at RIBF
K. Tanaka,*1 Y. Uwamino,*1 H. Sakamoto,*1 R. Hirunuma-Higurashi,*1 H. Mukai,*2 A. Akashio,*1 T. Okayasu,*1
R. Suzuki,*3 M. Takekoshi,*3 Y. Yamauchi,*3 S. Fujita,*1 H. Aiso,*1 K. Igarashi,*1 S. Iizuka,*1 and N. Usudate*1
Residual radioactivity at the cyclotron deflectors wasmeasured just before maintenance works were carried out inthe summer of 2014. The same measurement has been
performed regularly since 1986, and the variations in thedose rates are shown in Fig. 1. Considering that the dose

Fig. 1. Dose rates of residual radioactivity at the
deflectors of five cyclotrons.

rate depends on the beam intensity and the cooling time, thetrend has not changed considerably since 2006, when RIBF
operation started.
The residual radioactivity was measured along the beamlines after almost every experiment. Points 1–26, marked
with solid circles in Fig. 2, are locations where
high-residual dose rates were usually observed. Table 1 lists
these dose rates and the measurement dates, beam
conditions, and the decay periods after the end of operation.
The conditions for the data are chosen to be maximum
doses among the measured data at each points. The
maximum dose rate was found to be 17 mSv/h at point 13,
which is the neighbor of the G01 Faraday cup.
We continuously monitor the radiation in and around the
RIBF facility by using neutron and gamma area monitors.
In 2014, the annual dose at the site boundary were less thanthe detection limit of the monitors after backgroundcorrection. The neutron dose had been lower than thedetection limit of 2 µSv/y and the γ-ray dose had been
lower than the detection limit of 8 µSv/y. Therefore, theannual total dose in 2014 was less than 10 µSv/y, which
was considerably lower than the legal limit of 1 mSv/y.

G01
targetD1 magnet

Fig. 2. Layout of beam lines at RIBF. Locations listed in Table 1 are indicated. G01, the target, and D1 magnet are also
shown.
*1

RIKEN Nishina Center*2

Japan Environment Research Corporation
Daiwa Atomic Engineering Corporation*3- 323 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅳ. OPERATION RECORDS

Table 1. Dose rates measured at beam lines in 2014. Points
1−26 indicate the measured locations shown in Fig. 2.
Dose
Decay
Date Particle Energy Intensity period
Point rate (M/D)(MeV/u) (pnA)(μSv/h)(h)Fig. 3. Accumulated leakage radiation at the boundaryof the radiation-controlled area.
The dose rates at the radiation-controlled area in 2014
have been monitored. Three monitors are placed at theboundary of the radiation-controlled area. One is in thecomputer room of the Nishina building, and the other two
are on the roofs of the IRC and BigRIPS. The highest
observed value was 142 µSv/y at the IRC roof as a result of
beam loss at the transport line between SRC and BigRIPS.
Figure 3 shows the annual neutron dose at these locations
since 1999. These were considerably lower than the legal
limit of 1.3 mSv/3 month. The dose on the BigRIPS roof
was below the detection limit of 3 µSv/y for neutrons.
The water in closed cooling systems at BigRIPS was
sampled after the 2014 operation of RIBF. A 345-MeV/u 20
particle nA, on average, 238U beam was provided during
April and May, and during October and November. A 70Zn
75 particle nA was provided in May and June. A 400
particle nA 48Ca beam was in November and December.
Radionuclide concentrations were measured by using aliquid-scintillation counter and a Ge detector to comparethem with the legal limit. The results are shown in Table 2.
After operation with the intense 48Ca beam, the summationof the ratios of the concentrations to the legal limits for thedrain water of all the radionuclides at the BigRIPS became
approximately 1/4, and the water was transferred into thedrain tank before the next operation. This is to prevent
contamination of the room in case of a water leakage. The
water in the drain tank, which contains drain water fromother places, is released after the concentration ofradionuclides is confirmed to be lower than the legal limit.
This water circulates in the closed system with ion
exchange resins. Thus, the nuclides in waters listed in Table
2, with the exception of tritium, are already filtered values.
However, tritium accumulates in the water because thenuclide has a long half life of 12.3 year and is difficult toremove with filters. At the measurement before beamirradiation in 2014, the concentration of tritium in water in

1
2

55
650

7/23
7/23

α
α

12.5
12.5

400
400

54
54

3

450

7/23

α

12.5

400

54

4

100

10/8

Kr-84

70

0.07

19

5

1000

11/14

U-238

10.75

1430

13

6

190

12/16

Ca-48

63

200

2215

7

80

7/23

N-14

135

500

15621

8

1300

12/16

Ca-48

45.4

938

113

9

2000

7/23

O-18

88

51

534

10

70

7/23

O-18

88

51

534

11

170

12/16

Ca-48

345

530

110

12

5000

12/16

Ca-48

345

530

110

13

17000

12/16

Ca-48

345

530

110

14

550

12/16

Ca-48

345

530

110

15

700

12/16

Ca-48

345

530

110

16

100

12/16

Ca-48

345

530

110

17

400

12/16

Ca-48

345

530

110

18

750

12/16

Ca-48

345

530

113

19

100

12/16

Ca-48

345

530

113

20

150

12/16

Ca-48

345

530

113

21

1500

12/16

Ca-48

345

530

113

22

3000

12/16

Ca-48

345

530

113

23

7000

12/16

Ca-48

345

530

113

24

2800

12/16

Ca-48

345

530

113

25

325

12/16

Ca-48

345

530

113

26

150

12/16

Ca-48

345

530

113

all systems was approximately 3 Bq/cm3.
In 2014, the primary beam mode was newly mounted on
the safety management system of RIBF by considering thehigh radiation dose risk due to the intense beam. The target
intensity of the primary beam in RIBF is 6 × 1012
particle/second on the production target of BigRIPS. Then,a secondary beam of low intensity is generated via a nuclear
reaction and separation through BigRIPS. However, in theexperimental rooms located downward from BigRIPS, thepermitted beam intensity is 107 particle/second both forprimary and secondary beams. In RIBF operation, faintprimary beams are sometimes derived to the experimentalrooms directly. If intense primary beams more than thepermission derived to the experimental rooms owing toaccelerator trouble etc., the interlock system work in a
moment and stop the beam automatically. However, a delayof few seconds is necessary before a beam is stopped by theinterlock system operation. There may be a serious risk ofradiation exposure to workers even in the neighbor rooms
that are outside the irradiated area. Therefore, the safety- 324 -

Ⅳ. OPERATION RECORDSmanagement system was improved to inhibit theunexpected radiation exposure.
The primary beam mode in the radiation control systemaffects the restriction area, accelerator operation, and beamtransport operation. When the primary beam mode is started,the entry-forbidden area is first expanded to the neighborexperimental rooms of the beam delivered area. Secondly, acombination of the attenuation devices of the accelerator,
which control the beam intensity, is limited to regulate thebeam intensity less than permitted limit. Additionally, while
the primary beam mode is off, the magnetic field of the D1
magnet of BigRIPS, which determines whether the primaryor secondary beam is transported to the experimental rooms,
is always monitored. Moreover, if the value corresponds toa primary beam transportation, the safety management
system does not permit beam irradiation until the primarybeam mode is on, which means no-entry allowed to theneighbor experimental rooms. With these improvements,
radiation exposure risk due to unexpected intense beams is
mitigated.

RIKEN Accel. Prog. Rep. 48 (2015)

Table 2. Radionuclide concentrations in cooling water of
BigRIPS, the allowable legal limits for drain water, and theratio of the concentration to the allowable limit.
Concentration[a] Limit[b] Ratio to
Cooling
Nuclidewater(Bq/cm3)(Bq/cm3) limit [a/b]
H-3
14
60
0.23
Be-7
1.5e-330
4.9e-31)
BigRIPSCo-58
8.2e-41
8.2e-4F0 target
Mn-54
6.4e-41
6.4e-4summation
0.23
H-3
12
60
0.2
Be-7
1.7e-230
5.7e-4
BigRIPS
Co-57
1.2e-34
2.9e-4exit beam Co-58
3.7e-31
3.7e-3dump
Mn-54
9.7e-41
9.7e-4summation
0.21
H-3
11
60
0.18
BigRIPS
Be-7
0.14
30
4.7e-3side-wall
Co-58
1.3e-31
1.3e-3
beam dump
summation
0.19
1) read as 4.9× 10-3

- 325 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅳ. OPERATION RECORDS

RILAC operation
E. Ikezawa,*1 T. Ohki,*2 M. Kase,*1 T. Nakagawa,*1 N. Sakamoto,*1 H. Okuno,*1 N. Fukunishi,*1
M. Komiyama,*1 A. Uchiyama,*1 T. Maie,*1 M. Nagase,*1 M. Fujimaki,*1 T. Watanabe,*1 H. Hasebe,*1
H. Imao,*1 H. Kuboki,*1 K. Ozeki,*1 K. Suda,*1 Y. Higurashi,*1 K. Yamada,*1 Y. Watanabe,*1 S. Watanabe,*1
T. Nagatomo,*1 T. Aihara,*2 H. Yamauchi,*2 K. Oyamada,*2 M. Tamura,*2 A. Yusa,*2 K. Kaneko,*2 and O. Kamigaito*1
The RIKEN heavy-ion linac (RILAC) has operated
steadily throughout the reporting period and has supplied
various ion beams for different experiments. Some statistics
regarding the RILAC operation from January 1 to
December 31, 2014, are given in Table 1. The total beamservice time of the RILAC accounted for 84.5% of its
operation time. The two operation modes of the RILAC, thestandalone mode and the injection mode, in which the beam
is injected into the RIKEN Ring Cyclotron (RRC),
accounted for 53.1% and 46.9% of the total beam service
time of the RILAC, respectively. For beam experiments andmachine study of the RI Beam Factory (RIBF), a70
Zn-ionbeam
anda2.650-MeV/nucleon
48
2.675-MeV/nucleon Ca-ion beam accelerated by the
RILAC were injected into the RRC from May 12 to June 7
and from November 12 to December 11 2014, respectively.
Table 2 lists the beam service times in the standalone modeof the RILAC allotted to each beam course in the RILAC
target rooms in 2014. The e2 beam course in target room no.
1 was used in experiments using the GARIS2. The e3 beamcourse in target room no. 1 was used in experiments using
the GARIS. The e6 beam course in target room no. 2 wasused in the analysis of trace elements. Table 3 lists theoperation time of the 18-GHz ECR ion source(18G-ECRIS) in 2014.
We carried out the following improvements and overhauls
during the reporting period.
1) In the RF systems, the DC high-voltage power supplies
were subjected to annual inspection. The major
components of mechanical parts were subjected tosimple inspection. The contact fingers for the trimmerof CSM cavities were replacedwith new ones.
2) Two water pumps were overhauled. The other water

pumps were subjected to simple inspection. All cooling
towers were subjected to monthly inspection and annual
cleaning.
3) All the turbomolecular pumps were subjected to annual
inspection. Cryogenic pumps used for the no. 1 and no.
2 cavities of RILAC and the A5 and A6 cavities of CSM
were overhauled. A compressor unit of the cryogenic
pump used for the no. 5 RILAC cavity was repaired.
We faced the following mechanical problems during thereporting period.
1) A section of the cooling pipe of an earth ring for the
lower stem in the FC-RFQ cavity had a vacuum leak.
We repaired the pipes with a repair material as a stopgap
measure.
2) Water was found to have splashed in the rf power feederof the no.1 RILAC cavity because of leakage from a
cooling pipe for the coaxial conductor. We replaced itwith new ones.
3) Water was found to have splashed in the CSM A4 cavity
because of leakage from a cooling pipe of the end drift
tube. We repaired the pipes with a repair material as astopgap measure.

Table 1. Statistics of RILAC operation from January 1 to
December 31, 2014.

Table 3. Operation time of the 18G-ECRIS in 2014.

Operation time of RILAC

2960.0 h

Mechanical problems

153.1 hStandalone RILAC

1327.3 hInjection into RRC

1172.6 h

Total beam service time of RILAC

2499.9 h

Table 2. Beam service time of the standalone RILAC
allotted to each beam course in target rooms
no. 1 and no. 2 in 2014.
Beam course

Total time (h)e2e3- 326 -

31.6
66.1

e6

29.7

2.2

Total

1327.3

100.0

Ion

Mass

N

14

Charge state
3

62.3

N

15

3

105.7

Na

23

7

504.0

Al

27

6

216.0

Ar

40

11

144.0

Ca

48

10,11

1487.6

Zn

70

15

609.2

Kr

82

18

216.0

Kr

86

18

120.0

Total

RIKEN Nishina Center＊2
SHI Accelerator Service Ltd.
＊1

%

419.7
878.0

Total time (h)3464.7

Ⅳ. OPERATION RECORDS

RIKEN Accel. Prog. Rep. 48 (2015)

AVF operations in 2014
N. Tsukiori,*2 M. Fujimaki,*1 T. Fujinawa,*1 N. Fukunishi,*1 S. Fukuzawa,*2 M. Hamanaka,*2 H. Hasebe, *1
Y. Higurashi,*1 E. Ikezawa,*1 H. Imao,*1 S. Ishikawa,*2 T. Kageyama,*1 O. Kamigaito,*1 M. Kase,*1
M. Kidera,*1 K. Kobayashi, *2 M. Komiyama,*1 Y. Kotaka,*3 R. Koyama,*2 H. Kuboki,*1 K. Kumagai,*1
T. Maie,*1 M. Nagase,*1 T. Nagatomo,*1 T. Nakagawa,*1 M. Nakamura,*1 T. Nakamura,*2 M. Nishida,*2
M. Nishimura,*2 J. Ohnishi,*1 Y. Ohshiro,*3 H. Okuno,*1 K. Ozeki,*1 N. Sakamoto,*1 J. Shibata,*2 K. Suda,*1
A. Uchiyama,*1 T. Watanabe,*1 Y. Watanabe,*1 K. Yadomi,*2 K. Yamada,*1 and S. Yamaka*3
In 2014, the total annual operation time of the K70 AVF
cyclotron (denoted as AVF hereafter) was 2942 hours asshown in Table 1. This was increased by 311 hours
compared with that in 2013. In this duration, the time forbeam tuning was 1240 hours, which was 274 hours longer
than that in 2013. Most of the increased time (311 hours)
was spent on beam tuning because the time for beam tuningfor “Injection to RRC-SRC” was increased to two to threetimes longer than usual, and it took considerable time torecover from problems. On the other hand, the total beam
supply time was 1702 hours, which was classified into three
categories: “Injection to RRC”, “Injection to RRC-SRC”,
and “AVF standalone”. The operation times for these three
categories are listed in Table 1.
All of the beams accelerated by the AVF in 2014 arelisted in Table 2. In this table, the following beams wereaccelerated for the first time in 2014: 16O (4.9 MeV/u), 84Kr
(3.97 MeV/u),  (12.5 MeV/u), 11B (5.0 MeV/u), 19F (6.08
and 6.768 MeV/u), and  (7.5 MeV/u). The supplied
courses were as follows (in order of the supplied time): RI
production, RRC-SRC, CRIB, RRC-E5, Student Ex, and
E7B.

2013
2631
966

2014
2942
1240

Injection to RRC
Injection to RRC-SRC

738
118

208
455

AVF standalone
Beam course (AVF standalone) (hr)
E7A
E7B
C03

809

1039

480
18
311

335
58
646

Particle
p
d
d



6
Li
7
Li
7
Li
11
B
12
C
16
O
18
O
19
F
19
F
22
Ne
40
Ar
56
Fe
84
Kr

E (MeV/u)
12.0
12.0
4.9
6.5
7.5
12.5
11.2
5.6
8.6
5.0
7.0
4.9
6.07
6.08
6.768
6.1
5.2
5.0
3.97

CourseRI production
RI production
RRC-SRC
Student Ex.
RI production
RI production
CRIB
CRIB
E7B
CRIB
RRC-E5
RRC-SRCRI production
RI production
RI production
CRIB
RRC-E5RRC-E5RRC-E5(1) During 40Ar beam tuning, the beam stopped
unexpectedly at RRC. This was due to an incorrect
arrangement of the readout-cable of baffle slits, which cut
across the beam trajectory in the chamber of the RRC.
(2) During 6Li beam supply, the beam current decreased
at the ion source. To investigate the cause, the ion source
was disassembled. Consequently, some contaminations
were observed and lack of 6Li metal was found.
(3) During 12C beam tuning, one of the hollow
conductors from the magnetic channel of the AVF cracked
and cooling water sprayed out from that crack. The crack
was temporarily caulked by putty because it was difficult toclose the crack by weld. The beam tuning was restarted
without any problems.

Table 1. AVF operation statistics in 2014.
Total operation time (hr)Beam tuning

Table 2. AVF beam list in 2014.

The total fault time was 118 hours. The main faults arelisted in Table 3, in descending order of time spent on
restoration, and details are indicated below.

RIKEN Nishina Center
SHI Accelerator Service Ltd.
＊3
Center for Nuclear Study, the university of Tokyo＊1＊2- 327 -

Table 3. Main faults in 2014. See text for details.
(1)
(2)
(3)

Date
6th September
13th May
16th September

Time for restoration (hr)
22
18
17

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅳ. OPERATION RECORDS

Present status of the liquid-helium supply and recovery system†
T. Dantsuka,＊1 H. Okuno,＊1 M. Nakamura,＊1 M. Kase,＊1 S. Tsuruma,＊1
M. Ohshima,＊2 H. Miura,＊2 H. Shiraki,＊2 H. Hirai,＊2 H. Hazama,＊2 and H. Shiba＊2
The liquid-helium supply and recovery system1), which
can produce liquid helium at a liquefaction rate of 200 L/hfrom pure helium gas, has been under stable operation since
the beginning of April 2001. The volumes of liquid helium
supplied each year from 2001 to 2013 are shown in Fig. 1.
The volume gradually increased from 2001 to 2008 but
sharply increased in 2010, before decreasing sharply in
2011, and again sharply increasing in 2012.
We improved our recovery system in 2014. A new
recovery line was connected to the existing line of the
Nanoscience Joint Laboratory at the Emergent Matter
Research Facilities.
The purity of helium gas recovered from laboratories
gradually improved once the construction of the system wascompleted. Currently, the impurity concentration in therecovered gas rarely exceeds 200 ppm. The volume ofhelium gas recovered from each building in the Wako
180000160000140000Liquid Helium (L)12000010000080000
60000

campus and the volume transported to the liquid helium
supply and recovery system were measured. The recovery
efficiency, which is defined as the ratio of the amount ofrecovered helium gas to the amount of supplied liquid
helium, was calculated. The recovery efficiency for thebuildings on the south side of the Wako campus, such as the
Cooperation Center building of the Advanced Device
Laboratory, the Chemistry and Material Physics building,and the Nanoscience Joint Laboratory building, increased tomore than 90%.
However, the system experienced malfunctioning at theend of September 2014. The motor of helium compressor
failed and we could not supply liquid helium for a period of
two and a half months. One cause of motor failure wasdeterioration due to age. We updated the inverter of thehelium compressor in March 2014.

Magnetic Materials Laboratory
Low Temperature Physics Laboratory
Advanced Device Laboratory
Condensed Molecular Materials Laboratory
Molecular Characterization Team
Surface and Interface Science Laboratory
Surface Chemistry Laboratory
Radioactive Isotope Physics Laboratory
Exploratory Materials Team
Other laboratories

40000
20000
0
2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

Fiscal Year

Fig.1. Volumes of liquid helium supplied to laboratories for each fiscal year from 2001 to 2013†

Condensed from the article in Phys. Rev. Lett. 85, 1827 (2000)
RIKEN Nishina Center＊2
Nippon Air Conditioning Service K.K＊1

References

1) K. Ikegami et al.: RIKEN Accel. Prog. Rep. 34, 349 (2001).

- 328 -

H. Okuno,∗1 T. Dantsuka,∗1 M. Ohshima,∗2 H. Shiraki,∗2 H. Hazama,∗2 A. Mikami,∗2 H. Miura,∗2 H. Shiba,∗2
M. Kubota,∗2 H. Hirai,∗2 and M Haneda∗2
net required that the power supply of all the superRIKEN
Accel.We
Prog.
Rep. find48 (2015)
conducting trim coils be shut
down.
could
no
signs of an increase in temperature. Thus we suspect
refrigerator, and four He buffer tanks for cooling thethat this comes from the noise of the control system.
240-MJ superconducting magnets used for the SRC,
Operation of the superconducting ring
cyclotron cryogenic system
On December 25, the flow rate of the cooling chanhas a cooling capacity of approximately 1 kW at 4.5 K
nel for one small power lead suddenly increased: weand an inventory of 5000 L of liquid He. The cooling
∗1
∗1
∗2
∗2
∗2
∗2
H. Okuno,
T. Dantsuka,
M. Ohshima,
Shiraki,∗2 suspect
H. Hazama,
A.impurity
Mikami,∗2
H. Miura,
H. Shiba,that thedroppedor a control
valve
systemwas operated
for approximatelynine H.
months∗2∗2∗2
M. Kubota,
H. Hirai, in and
Hanedathe M
line.
We believe that we need to monitor thein 2014, with a three-month maintenanceshutdown
impurity and aging of the control system regulary.
in summer (July–August) and a shutdown to conserve
electricalpower
in January.
The SRC(Superconducting
Ring Cyclotron) cryonet required that the power supply of all the superWe
experienced
problems
in the operagenic system, whichsome
consistsof threewith
compressors,a He
conducting trim coils be shut down. We could find notions,
some ofandwhich
us tanks
to stopfor
thecooling
operation
refrigerator,
fourrequired
He buffer
thesigns of an increase in temperature. Thus we suspectofthe Hesuperconducting
refrigerator andmagnets
the compressor.
240-MJ
used for The
the probSRC,
that this comes from the noise of the control system.
lems
listedcapacity
in Tableof1.approximately
We stopped theoperation
has aarecooling
1 kW
at 4.5 ofK
On December 25, the flow rate of the cooling chanthe
compressor
duringHe He.
purification
proand helium
an inventoryof 5000
L of theliquidThe coolingnel for one small power lead suddenly increased: we
cesson February
19, 2014
because heavy snowon thatsystemwas operated
for approximatelynine months
suspect that the impurity dropped or a control valve
day
stoppedtheafanin the cooling
tower for cooling
wain 2014,
withthree-month
maintenanceshutdown
in the line. We believe that we need to monitor theter.
Some (July–August)improvements wereout totoconserve
prevent
in summer
and acarried
shutdown
impurity and aging of the control system regulary.
thefans fromstopping
due to heavy snow. A temperelectricalpower
in January.
ature
in the someHe refrigerator
also demonstrated
We sensor
experienced
problems within the operaunusual, and
we presume
thatthisstop
wasthebecausethetions, someof whichrequiredus tooperation
attachment
between thepipesensor becameof the He refrigerator
andtheandcompressor.
The loose.
probUnfortunately
thissensorplays
a role thein theinterlocklems are listed in
Table
1. We
stoppedoperationoflogic,
but welet it go because
to open the cold
the helium
compressor
during wethehadHe purification
proboxto February
improve theOctober
29thatthecess on19, attachment.
2014 because On
heavy
snow onsecondand third
turbines
trippedtowersuddenly
due to wathe
day stopped
the fanin the coolingfor coolinghighspeed improvementsof the third turbine.
However,
couldter. Somewere carriedout towepreventfind
no signtheir highspeedfrom snow.
the trendgraph.
the fans
fromofstoppingdue
to heavy
A temperWe
thiscaused bythedemonstrated
noise of theaturesuspectsensor thatin theHewas
refrigerator
also
control
Wepresume
will checkthethisrotation
speed monunusualsystem.
, and wethat
was becausetheitorsystem between
using a thesignalgenerator
duringtheloose.
next
attachmentpipeand sensor
becamesummermaintenance.
Unfortunately
this sensor plays a role in the interlock
Duringoperationfrom April
to June,thetheheliumlogic,
but thewe letit go because
we hadto opencold
flow
rateimproveof the coolingchannel forOna smallpower
box tothe attachment.
October
29 leadthegradually
Thistrippedsuggests
trappingof tosomesecond anddegraded.
third turbines
suddenly
due
theimpuritythat
the flow rate.
On November
high speedof decreased
the third turbine.
However,
we could
22
systemthe superconducting
magfindthe
no interlock
sign of theirhighforspeed
from the trend graph.
We suspect that this was caused by the noise of thecontrol system. We will check the rotation speed monitor system using a signal generator during the next
summer maintenance.
Subsystem
Date
Problems
During the operation from April to June, the helium
He compressor February 19
Fans in the cooling stopped working due to heavy snow
flow rate of the cooling channel for a small power leadHe refrigerator April – June
A temperature sensor behaved unusually
gradually degraded. This suggests
trappingof some of the pre-cooling valve (warm gas injection)
October 12
Mishandling
impurity that decreased theOctoberflow rate.
On
November
29
Trip of the second and third turbines.
22 the interlock
system for April
the superconducting
magSc. magnet– JuneGradualdecrease of the flow rate for small current power leads
The SRC (Superconducting Ring Cyclotron) cryo-Ⅳgenic. OPERATION
system,RECORDS
which consists of three compressors, a He

November. 22
October 29

Discharge of the superconducting trim coils
Sudden increase of the flow rate for a small current power lead

Table 1. Lists of problems that occured in the He cooling system in 2014.
∗1∗2

Subsystem
Date
RIKEN Nishina Center
He compressor
February 19
Nippon Kucho
Service Co., Ltd
He refrigerator April – June
October 12
October 29
Sc. magnet
April – June
November. 22
October 29

Problems
Fans in the cooling stopped working due to heavy snow
A temperature sensor behaved unusually
Mishandling of the pre-cooling valve (warm gas injection)
Trip of the second and third turbines.
Gradual decrease of the flow rate for small current power leads
Discharge of the superconducting trim coils
Sudden increase of the flow rate for a small current power lead

Table 1. Lists of problems that occured in the He cooling system in 2014.
∗1∗2

RIKEN Nishina Center
Nippon Kucho Service Co., Ltd- 329 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅳ. OPERATION RECORDS

Present status of the BigRIPS cryogenic plant
K. Kusaka,＊1 M. Ohtake,＊1 T. Kubo,＊1 K. Yoshida,＊1 M. Ohshima,＊2 A. Mikami,＊2 H. Shiba,＊2 H. Hazama,＊2

RIKEN Nishina Center
Nippon Kucho Service Co., Ltd.
＊2
Mayekawa Mfg. Co., Ltd.
＊1
＊2

250
200
150
100
50
0

0

2000

4000

6000

8000

10000 12000 14000

Operation Time of Coalescer Filters [h]Fig. 1. Oil contamination at the entrance of the second
coalescer vessel (3SP).
Oil Contamination [wt. ppm]

In addition to periodic calibration of pressure andtemperature sensors, maintaining the oil-removal module in
the helium compressor unit is crucial to ensure long-term
continuous operations of BigRIPS1). The oil-removal
module comprises an oil vessel with a demister (1SP), threecoalescer vessels (2SP, 3SP, and, 3.5SP), and two adsorbent
vessels (4SP and 5SP). We replaced the activated charcoal
and molecular sieves in 4SP every year and the activatedcharcoal in 5SP every 2 years to ensure low oil
contamination in helium gas at the exit of the oil-removal
module.
Before the adsorbent vessels, oil in the helium gas isseparated by coalescer filters in three coalescer vessels. The
drain oil separated from the helium gas is sent to thecompressor via a drain line with solenoid valves, dependingon the oil level in the coalesce vessel. By measuring theoperation interval of the solenoid valves, the oil
contamination level of the helium gas at the entrance of thesecond and the third coalesce vessel can be evaluated. The
expected oil contamination levels at the entrance of the
coalescer vessels are 15-50 and 0.75-1.25 wt. ppm for 3SP
and 3.5SP, respectively. The oil contamination level canalso be easily measured with an oil check kit2).
Each coalescer vessel contains four coalescer filters,
manufactured by Domnick Hunter3), and all the filters were
replaced every 2 years, since 2008. However, the filters
used for 6 years were discontinued and replaced with thesuccessive product of Domnick Hunter in 2014.
Figure 1 shows an estimate of the oil contamination levelat the entrance of 3SP as a function of the coalescer filter
operation time from the oil drain from the 3SP. The navy
blue, green, and, yellow diamonds represent the estimates
for the 2008-2009, 2010-2011, and 2012-2013 operations,
respectively. The estimate for the 2014 operation with newcoalescer filters is shown as pink diamonds. The estimates
increase to 50~75 wt. ppm up to an operation time of2000 hours for the period of 2008-2009 and 2010-2011 andthen stays constant. The estimate for the 2014 operationshows similar behavior. On the other hand, the estimate forthe period of 2012-2013 scatters largely and showsmonotonous increasing tendency. The oil check kit values
are also shown as open symbols in Fig. 1. The open
triangles, squares, circles, and diamonds represent results
for the 2008-2009, 2010-2011, 2012-2013, and 2014
operations, respectively.

Oil Contamination [wt. ppm]

H. Miura,＊2 H. Shiraki,＊2 H. Hirai,＊2 M. Haneda,＊2 M. Kubota,＊2 M. Noguchi,＊3 and N. Suzuki＊3

10
8
6
4
2
0

0

2000

4000

6000

8000

10000 12000 14000

Operation Time of Coalescer Filters [h]Fig. 2. Oil contamination at the entrance of the third
coalescer vessel (3.5SP).
In Fig. 2, we show a similar analysis of the oil
contamination at the entrance of 3.5SP. Symbols and colors
used in Fig. 2 are same as those in Fig. 1. A gradualincreasing tendency of the oil contamination is seen in all
operation periods. Following the large oil contamination at
the entrance of the 3SP, the results for the period of
2012-2013 are approximately twice of that for the otherperiod. Since the solenoid valve of 3.5SP was operated only
once since Sept. 2014, only one pink symbol is plotted inFig. 2. Although the performance efficiency of the newfilter elements seem to be similar to that of discontinued
ones, we shall continue observations and investigate
oil-removal modules carefully in the coming maintenanceperiod.
References

1) K. Kusaka et al.: RIKEN Accel. Prog. Rep. 41, 244 (2008).
2) K. Kusaka et al.: RIKEN Accel. Prog. Rep. 43, 309 (2010).
3) http://www.parker.com/- 330 -

Ⅳ. OPERATION RECORDS

RIKEN Accel. Prog. Rep. 48 (2015)

Operation report on the ring-cyclotrons in the RIBF accelerator complex
S. Fukuzawa,*3 N. Sakamoto,*1 T. Dantsuka,*1 M. Fujimaki,*1 N. Fukunishi,*1 T. Fujinawa,*1M. Hamanaka,*3 H. Hasebe,*1
Y. Higurashi,*1 E. Ikezaw,a*1 H. Imao,*1 S. Ishikawa,*3 M. Kase,*1 T. Kageyama,*1 O. Kamigaito,*1 M. Kidera,*1
K. Kumagai,*1 H. Kuboki,*1 K. Kobayashi,*3 Y. Kotaka,*2 M. Komiyama,*1 R. Koyama,*3 T. Maie,*1 M. Nagase,*1
T. Nagatomo,*1 T. Nakagawa,*1 M. Nakamura,*1 T. Nakamura,*3 M. Nishida,*3 M. Nishimura,*3 J. Ohnishi,*1
Y. Ohshiro,*2 H. Okuno,*1 K. Ozeki,*1 J. Shibata,*3 K. Suda,*1 N. Tsukiori,*3 A. Uchiyama,*1 T. Watanabe,*1 Y. Watanabe,*1
S. Watanabe,*1 K. Yadomi,*3 S. Yamaka,*2 K. Yamada,*1 and H. Yamasawa*1
The operation of ring-cyclotrons (RRC, fRC, IRC, andSRC) in the RIBF accelerator complex in 2014 is reported.
Table 1 summarizes the accelerated beams provided forusers. The scheduled beam service time was 3192.3 h. The
delivered beam service time was 2967.1 h. Note that 82% of
the beam service time was distributed to the experimentsthat utilize beams accelerated by SRC and the remaining
18% was distributed to the experiments in which the beams
extracted from RRC are used by the users. Beamavailability, which is the most important parameter
indicating the stability of operation, was 92.9%.
In March 2014, the campaign-type experiments utilizing
the 238U 345 MeV/u beam were performed. In the beginningof the beam tuning procedure, we experienced a hardware
fault related to the main differential probe (MDP) of the
fRC twice, which resulted in 4.5-day delay of the beam start
time. Once the beam service started on March 27, fiveexperiment programs were performed without any issue
with accelerators. After an 8.3 -day break of the IRC and
SRC operations scheduled for the 28-GHz ECR ion source,
the beam service of uranium ions was resumed and it
finished on May 13. Three experimental programs were
performed after the break.
From May 16, we started a beam service of a 345-MeV/u
70
Zn beam. During the beam service, a hardware fault
with the control system of the gas cogeneration system that
supplies backup electricity to the helium refrigerator used
for SRC occurred, which resulted in an 8-day beam service
interruption in total.
After the problem was fixed, the beam was stably delivered
until June 7. Owing to the beam current upgrade in the
18-GHz ECR ion source, the beam intensity increased to

123 particle nA, which corresponds to 120% of the intensity
recorded during the beam service performed in 2012.
Since June 9, deuteron and 18O beams (250 MeV/u) areprovided for RIBF experiments. In these beam services, low-emittance high beams with stability were strongly requiredby the users to realize high resolution measurements.
The operation parameters of the accelerators used were
finely tuned and the purity of single-turn extraction was
0.2%. This high-quality operation was maintained by finetuning as necessary ,throughout these beam services.
After a shutdown scheduled for a routine maintenance insummer, the 238U (345 MeV/u) beams were delivered for six
RIBF experiments from October 20 to November 18. The
maximum beam intensity of 27.9 particle nA was recorded
during this beam service.
Next, from November 18 to December 11, 48Ca (345MeV/u) beams were delivered for four RIBF experiments.
During these beam services, the operational total
acceleration voltage of the SRC RF system was upgraded to
2.4 MV/turn and a voltage applied to the electric deflection
channel of SRC was 128 kV. These parameters are close to
their maximum capability and essential in producing a
low-beam-loss operation required for high-power beams. In
addition to an ion-source improvement, the maximum beam
intensity recorded in the beam service ,0.53 particle A,
was obtained. This corresponds to the beam power of 8.8
kW which is the power record of the beams obtained in
RIBF.
In addition to the biological experiments at E5B, the beamservices of 48Ca for RIPS (E6) and 136Xe for KISS (E2B)
were performed.

Table 1. Summary of the accelerated beams in 2014
Ions
12

EnergyAccelerat ors(MeV/u)
135

C
40
Ar

Beam Course

Beam Current(particle nA) Scheduled Delivered
requestedtime (h)Maxtime (h)*Downtime

Total time

(h)**

(h)

Availabilit y(%)***

E5B(Biology +MS)

1

393

71

71

0

71

100
100

95 AVF-RRC

E5B(Biology )

1

91.2

32

32

0

32

56

Fe

90

E5B(Biology )

1

2.8

20

20

0

20

100

48

Ca

63

200

235.3

108

103.1

1.2

104.3

95.4

84

70

1

0.1

85

72.9

9.8

82.8

85.8

Kr
136
Xe
238(235)

U

238

U
d

10.75
10.75
250

16

O

250

Ca

345

70

Zn(1st)345

70

Zn(2nd)345

238

U(1st)

345

238

U(2nd)

345

U(3rd)RILAC2-RRC

50 RILAC2-RRC-fRC

48

238

RILAC-RRC

345

AVF-RRC-SRC

E6(RIPS)E5B(Industry )

10

405

96

100.5

2.8

103.4

104.7

A02,D(MS)

N/A

1428

121

121

0

121

100

H course(MS)

N/A

125

15

15

0

15

100

10

510

252

268.1

42.7

310.8

106.4

10

41.8

108

125.4

18.6

144

116.1

500

530

492.2

474.1

18.1

492.2

96.3
92.7

E2B(KEK/KISS)BigRIPS
SHARAQ(CNS)
BigRIPS, ZDS SAMURAIRILAC-RRC-IRCSRC

RILAC2-RRC-fRCIRC-SRC

SHARAQ(CNS)

75

123

216

200.2

39.1

239.3

SHARAQ(CNS)

75

116.6

96

93.1

2.9

96

97

BigRIPS, ZDS,SAMURAI

10

22.1

540

384.4

159.6

544.1

71.2

BigRIPS,ZDS

10

25

408

385.2

94.8

480.1

94.4

BigRIPS,ZDS,SAMURAI,
EURICA

15

27.9

532.1

501

31.1

532.1

94.2

RIKEN Nishina Center
Center for Nuclear Study, the University of Tokyo＊3
SHI Accelerator Service Ltd.
＊1＊2

- 331 -

*Delivered time
= Supply time forBeam users.
**Down time
= Supply stop timecaused by accelerator
issues.
***Availability=Deliveredtime/scheduled time.

V. EVENTS

Ⅴ. EVENTS

RIKEN Accel. Prog. Rep. 48 (2015)

ARIS2014 - 2nd Conference on Advances in Radioactive Isotope
ScienceT. Motobayashi∗1
The second conference on Advances in Radioactive
Isotope Science (ARIS 2014) was held at the Ito International Research Center in Tokyo on June 1-6,
2014. It was jointly organized by the RIKEN Nishina
Center and CNS, the University of Tokyo, sponsored
by IUPAP (International Union of Pure and Applied
Physcs), and supported by several Japanese institutions and societies. The first ARIS conference washeld in 2011 in Leuven, Belgium, by merging the twomeetings, ENAM (International Conference on Exotic
Nuclei and Atomic Masses) and RNB (International
Conference on Radioactive Nuclear Beam). In a joint
assembly of the advisory committees of the two meetings, the ultimate goal of ARIS was set to create the“flagship conference” series on the science of radioactive isotopes, including the physics of exotic nuclei andstudies with RI beams. Since the Nishina Center andthe CNS have extensively studied on radioactive isotopes with excellent RI-beam facilities and their significant contributions in the near futre are foreseen, thesecond conference in Japan was very well-timed.
The scientific scope of ARIS 2014 was of the following subjects, taking over the ones of the first conference with some modifications: 1)nuclear structure,2)nuclear astrophysics, 3)fundamental symmetries andinteractions, 4)nuclear reactions and responses, 5)nuclear properties including atomic masses and fundamental constants, nuclear moments and radii, rare decay modes, and nuclei at the driplines, 6)nuclear EOS
and its implications, 7)heaviest elements and fission,8)radioactive isotope production and developments ofexperimental devices, 9)computational developments,
10)applications, and 11)other related issues.
On Sunday June 1, public lectures attracted a large

audience of about 300 people including high school students. The conference started on Monday with the welcome address by the Conference Chair, Hideto En’yo.
In the first scientific session chaired by the Conference
Co-chair, Takaharu Otsuka, Robert Janssens gave the
keynote talk addressing “big” questions in the field andproviding an overview of the new and important developments after the first conference.
The number of registrants turned out to be 407 from27 countries. Thus the higly optimistic goal set by theorganizers was reached, reflecting the considerble interest and amount of work done in this the research
field. The conference photo shown below (Fig. 1) delivers the lively atmosphere of the conference.
There were 48 plenary talks and 82 oral presentations in three parallel sessions held on June 3 and 6 afternoons. Recent highlights from RIBF, the new neutron magic number 34 experimentally confirmed forthe neutron-rich nucleus 54 Ca and first life-time measurements for a number of nuclei in the r-process path,for example, attracted much attention as well as new
results from world facilities. Among 239 papers presented in poster sessions, seven posters presented byyoung scientists were selected as “Best Posters”, andthe awarding ceremony took place in the closing session. Angela Bracco summarized the conference byselecting major aspects from numerous presentations
and emphasizing the bright future of the field.
The conference proceedings will be published electronically in the JPS Conference Proceedings Volume
6 (2015). The next ARIS conference will be jointly
hosted by NSCL and TRIUMF.

Fig. 1. Conference photo taken in the session hall.
∗1

Scientific Secretary of ARIS2014, RIKEN Nishina Center- 333 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅴ. EVENTS

The 8th Nishina School
T. Kishida∗1 and H. Ueno∗1
The RIKEN Nishina Center (RNC) has commenced
Nishina School to enhance international research relationship in the Asian Region through human-resource
development in the ﬁeld of nuclear physics. In this program, undergraduate students are being accepted by
the RNC from Peking University since 2008 and fromSeoul National University since 2012 for two weeks every summer. Both the programs have been mergedsince 2013.
The 8th Nishina School was held from July 28 toAugust 8, 2014. The curriculum of the School was designed to introduce the pleasure of nuclear physics into
the undergraduate students from Peking University (5students) and Seoul National University (5 students).
The ﬁrst week, program consisted of lectures and basic experimental trainings. In the second week they
performed a real-beam experiment using the RIKEN
Pelletron accelerator, starting from its planning andfollowed by the analyses and the discussions. On thelast day of the School, the presentation session by thestudents was held. The program timetable in 2014 isshown in Fig. 1.
In response to a request for improving the management of the Nishina School proposed by the people incharge of the Nishina School held in the last year, theRNC director convened a preparatory meeting on December 25, 2013, to discuss the development of an organizational management system of the Nishina School
and the improvement of transparency in the decisionmaking process. For this purpose, it was determined at
the meeting to newly set up the Nishina School Steering Committee. The Committee is composed of Ueno
(Chair), En’yo, Sakurai, and Sakai. The Committee
Meetings were held four times on March 3, April 23,
May 26, and July 15, 2014. Kishida, principle of the
Nishina School, also attended all these Meetings as anobserver. Their meeting minutes were reported at thesecond, fourth, and ﬁfth RNC Coordination Committee Meetings held in 2014.
In order to enhance the experimental training, theCommittee determined to incorporate accelerator experimental training into the curriculum. In this year,
cross-section measurements were conducted for the
12
C(p,γ)13 N reaction utilizing a proton beam at Ep =1600–1850 keV delivered from the RIKEN Pelletron
accelerator. Technical instructions of the experimental training were provided by Research Scientists inNuclear Spectroscopy Lab., Spin Isospin Lab., and RI
Physics Lab. They were technically assisted by IPA
and JRA researchers of these laboratories.
The Committee also considered that enhancement∗1

RIKEN Nishina Center- 334 -

of working-level dialogue among the persons in chargeof, e.g., the entire program, experimental trainings,
and oﬃce procedures is an important subject. This
year, three working-level meetings, including an onsite meeting at the Pelletron, were held on July 4, 10,
and 18. Despite such a gradual improvement, the situation can be further improved.
All the students had a good experience and enjoyed
the School and life at the RNC. Figure 2 shows a photograph taken at the opening ceremony on July 28.
First
Week

Jul. 27

Jul. 28

Jul. 29

Jul. 30

Jul. 31

Aug. 1

Aug. 2

(Sun)

(Mon)

(Tue)

(Wed)

(Thu)

(Fri)

(Sat)

Training B:

Accelerator(Kase)

Lecture 2:

OpeningMorning(10:30−11:45)

Intro. ofLecture 4:
Nucl. Phys.
Scintillation(Ogawa)detectors
e-Learning (Doornenbal)
Lecture 3:

Afternoon 1

RIBF tour(13:30−14:45)

Lecture 1:(15:30−16:45)

Morning(10:30−11:45)

Afternoon 1,

ent

NaI detector− Analysis(Isobe)Lecture 6:

Nucl.
astrophys.

(Motobayashi)
Lecture 7:(Isobe)Student
interimpresention(1)

Safetytraining(Tanaka)

Aug. 3

Aug. 4

Aug. 5

Aug. 6

Aug. 7

Aug. 8Aug. 9

(Sun)

(Mon)

(Tue)

(Wed)

(Thu)

(Fri)

(Sat)

Labwork
Instruction 1:

Labwork:

Labwork
Instruction 2:

Exp.
Analysis
Pelletron
description beam timedetails(Doornenbal)(Zenihiro)(Nakao)Visit of
Pelletron

Labwork:

Data
Reportanalsysis preparation(Isobe)Labwork:

Result &Student
discussions
final
Data
presention(Isobe)analsysis(Zenihiro)
Interimpresention
Closing(3)
Labwork:(13:30−14:45)

Labwork:

Afternoon 2

Exp.
planning(Zenihiro)(15:30−16:45)

Afternoon 3

Training A:

Commun Oscilloscope
icatoin Coaxial Cable(Kishida)(Kishida)

Afternoon 2

SecondWeek

Nucl. Phys.
Training B:
Metrology
NaI detector(Sato)− Measurem

Lecture 5:

Interimpresention(2)

Technical
assistance:• Imamura• Ohtomo• Zengyang• Suzaki• Jin• PowelFig. 1. The curriculum and timetable of Nishina School
2014. The lectures and experimental trainings are indicated in blue and red, respectively.

Fig. 2. Photograph of Nishina School 2014.

Ⅴ. EVENTS

RIKEN Accel. Prog. Rep. 48 (2015)

The 27th World Conference of the International Nuclear Target
Development Society (INTDS2014)
H. Okuno,＊1 H. Hasebe,＊1 H. Kuboki,＊1 H. Imao,＊1 A. Yoshida,＊1
K. Morimoto,＊1 D. Kaji,＊1 K. Yoshida,＊1 and K. Sakuma＊1
The 27th World Conference o f the International Nuclear
Target Develop ment Society (INTDS 2014) was held fro mAugust 31th to September 5th, 2014 at the National
Museum of Emerging Science and Innovation (Miraikan) inOdaiba Tokyo, Japan with special emphasis on targets foraccelerator-based research. INTDS 2012 was organized by
the RIKEN Nishina Center for Accelerator-based Science,
Saitama.
The series of INTDS conferences dates back to 1963
when the "First Symposiu m on Research Materials for
Nuclear Measurements" was held sponsored by the Central
Bureau for Nuclear Measurements (CBNM; recently,
IRMM ‚ -Institute for Reference Materials andMeasurements) in Belgiu m. Since then, researchers
involved in target preparation shared their experience anddiscussed related problems during biennial conferences
hosted alternatively in Europe, North A merica, and Asia
(www.intds.org). The 23rd INTDS conference was held in
Tsukuba, Japan in 2006. It was delightful to meet again in
Japan on the occasion of the 27th International INTDS
conference.

More than 77 participating scientists fro m 17 countries(Belgiu m, Canada, China, France, Germany, India, Italy,
Japan, Korea, Pakistan, Poland, Ro mania, Russia, South
Africa, Swit zerland, UK, USA), met in Tokyo to present
over 67 scientific contributions covering the wide field of"State-of-the-art Technologies for Nuclear Target andCharge Stripper". A laboratory tour of the RIKEN RI Beam
Factory was included in the scientific program to introduce
the institution and laboratories. The conference comprised
eleven different sessions titled ‚"Targets and strippers for
RIBF", "Classical accelerator targets", "RI beams", "Gasstrippers", "Liquid strippers"‚ "Production targets"‚"Medical and industrial applications", "Radioactive targets","Target characterization", "Liquid and gas targets","Radioactive targets", and "Laser-related targets". The
sessions included many activ ities such as the discussion of
excit ing new developments or methods, reports on
improvements of established techniques, presentation ofscientific results by young scientists, and the introduction of
new groups and laboratories in the society.

Fig. 1: Photo of conference attendees＊1

RIKEN Nishina Center for Accelerator-Based Science- 335 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅴ. EVENTS

The 6th International Conference on Trapped Charged Particles andFundamental Physics
M. Wada,*1 P. Schury,*1 Y. Ichikawa,*1 and Y. Ito*1
The 6th International Conference on Trapped Charged
Particles and Fundamental Physics (TCP2014) was heldfrom 1st to 5th December, 2014 at the Takamatsu
International Conference Hall. Prior to the conference, apreschool (TCP school) for young researchers wasorganized from 28th to 29th November at the Nishina Hall of
RIKEN where inspiring lectures were given by S. Ulmer, R.
Thompson, R. Hayano, H. Katori, V. Dzuba, Yu. Litvinov,
W. Nörtershäuser. About 60 participants enrolled in theschool and half of them went to Takamatsu.
During the conference, a variety of scientific programs
using stored particles were actively discussed.
Anti-Hydrogens are routinely synthesized and precision
spectroscopy of them is being actively pursued.
Multi-reflection
time-of-flight(MRTOF)mass
spectrographs were put online at three different laboratories
at almost the same time at ISOLDE, RIKEN and GSI, andare also under preparation at TRIUMF, MSU, ANL, and
IBS in Korea. Advanced resonance detection methods in
Penning trap mass spectrometers were discussed. Several
fundamental symmetry studies using molecular ions, neutral
atoms and highly charged ions (HCI) were discussed. The
highlight of the conference was a sympathetically cooled
HCI crystal in a linear Paul trap by Heidelberg-Aarhus
collaboration. It can be a next-generation frequency
standard, but also provides a platform for research inphysics beyond the standard model such as time variation of
the fine structure constant. An Australian theorist suggeststhat Cf16+ is the best candidate for such research at present.

A total of 107 registered participants attended and 63% ofthem were from abroad. We invited 47 speakers. Of them,
45 accepted the invitation, 2 of whom later cancelled. We
accepted 23 oral presentations and 26 posters; additionally,
3 oral contributions included posters.
An international workshop, NNP2014, was held at thesame time and location, hence joint sessions and social
events were held.
In the international organization committee meeting, it
was decided that TCP2018 will be held in USA andorganized by G. Bollen of MSU.

Fig. 2 An atraction during the banquet.

Fig. 1 Participants of TCP2014 in Takamatsu＊1

RIKEN Nishina Center- 336 -

VI. ORGANIZATION AND ACTIVITIESOF RIKEN NISHINA CENTER(Activities and Members)

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

1. Organization
1.1 Organization Chart as of March 31, 2015

Quantum Hadron Physics Laboratory
Theoretical Nuclear Physics Laboratory
Strangeness Nuclear Physics Laboratory

Koji Hashimoto

Radiation Laboratory

RIKEN BNL Research Center

Masahiko Iwasaki

Samuel H. Aronson

Deputy Director:Robert Pisarski

Nishina Center Advisory Council

RIKEN Facility Office at RAL

Larry McLerranComputing Group

Taku Izubuchi
Yasuyuki Akiba

Philip KINGRadioactive Isotope Physics Laboratory

RIBF Research Division

Hiroyoshi Sakurai

Spin isospin Laboratory

Tomohiro Uesaka

Nuclear Spectroscopy Laboratory
Nishina Center Planning Office

Theory Group

Experimental Group

RBRC Scientific Review Committee (SRC) Meeting

RBRC Management Steering Committee(MSC)

Sub Nuclear System Research Division

Hideto En'yo

Advanced Meson Science Laboratory

Advisory Committee for the RIKEN-RAL Muon Facility

Theoretical Research Division

Emiko Hiyama

Mathematical Physics Laboratory

President RIKEN Ryoji Noyori

Tetsuo Hatsuda
Takashi Nakatsukasa

Hideki Ueno

High Energy Astrophysics Laboratory

Toru Tamagawa

Astro-Glaciology Research Unit

Yuko Motizuki

Research Group for Superheavy Element

Kosuke Morita

Superheavy Element Production Team

Kosuke Morita

Superheavy Element Research
Device Development Team
Nishina Center for Accelerator-Based Science

Hideto En'yo

Nuclear Transmutation Data Research Group

Hiroyoshi Sakurai

Theoretical Research
RIBF Research
RIBF synergetic-use coordinator:Tohru Motobayashi

Muon Data Team
High-Intensity Accelerator R&D Group

Osamu Kamigaito

Senior Advisor:Walter F. Henning
Senior Advisor:Yasushige Yano

Hideakii Otsu
Koichi Yoshida
Teiichiro Matsuzaki

High-Gradient Cavity R&D Team Naruhiko Sakamoto
High-Power Target R&D Team

Accelerator Group
Scientific Policy Committee

Fast RI Data Team
Slow RI Data Team

Deputy Director:Tetsuo Hatsuda

Deputy Director:Hiroyoshi Sakurai

Kouji Morimoto

Osamu Kamigaito

Deputy Director:
Hiroki OKUNO (Intensity Upgrade),
Nobuhisa FUKUNISHI (Stable and Efficient Operation),
Masayuki KASE(Energy-Efficiency Management)

Program Advisory Committee

Accelerator R&D TeamIon Source Team

Coordination Committee

Beam Dynamics &Diagnostics Team

Safety Review Committee

Hiroki Okuno
Takahide Nakagawa

RILAC Team
Cyclotron Team

Eiji Ikezawa
Naruhiko Sakamoto
Nobuhisa Fukunishi

Cryogenic Technology Team

Machine Time Committee

Hiroki Okuno

Infrastructure Management Team

Public Relations Committee
Instrumentation Development Group

Masanori Wakasugi

SCRIT Team
Research Instruments Group

Toshiyuki Kubo

Masayuki KaseSLOWRI Team
Rare RI-ring Team

Michiharu Wada
Masanori Wakasugi
Masanori Wakasugi

BigRIPS TeamSAMURAI Team
Computing and Network Team
Detector Team

Accelerator Applications Research Group

Tomoko Abe

Ion Beam Breeding TeamRI Applications Team

User Liaison and Industrial Cooperation Group

Hideyuki Sakai

Deputy Director: Hideki UENO(User Support)

Safety Management Group

Yoshitomo Uwamino- 337 -

User Support Office
Industrial Cooperation Team

Hiroki Okuno

Koichi Yoshida
Hideaki Otsu
Takashi Ichihara
Hiromi Sato
Tomoko Abe
Hiromitsu Haba
Ken-ichiro Yoneda
Atsushi YoshidaRIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

1.2 Topics in FY2014
In fiscal year 2014, RNC launched several interdisciplinary innovation programs as yet another new challenge for its researchers. One
such example is RNC’s participation in the ImPACT program which aims to significantly reduce and resource recycle high-level radioactive
waste. To achieve this goal, the organizational structure required to develop key technology for effective nuclear transmutation has beenrevised so that the nuclear reaction data of the long-life fission products can be obtained. RNC also participates in the Strategic Innovation
Program (SIP) in cooperation with eighteen other institutes in Japan to undertake the task of building a system for strategic omics breeding
technology.
With President’s Discretionary Fund providing the financial support of 450 million yen for international research collaboration, RNC
was able to execute approximately five months of RIBF operation in total. Accordingly, user time also reached its record-high 2597 hours.

Oct. 1, 2014

Mar. 31, 2015

Start of Nuclear Transmutation Data Research Groupassociated with following three teams
Fast RI Data Team
Slow RI Data Team
Muon Data Team
Start of High-Intensity Accelerator R&D Groupassociated with following two teams
High-Gradient Cavity R&D Team
High-Power Target R&D TeamEnd of Mathematical Physics Laboratory

2. Finances
As mentioned in “1. Administrative Topic in FY2014”, RNC executed approximately five months of RIBF operation. Breakdown
expenses of the RNC FY2014 budget and a transition for the past five years are shown in following graphs.
[Correction: In the 2013 edition, the FY2014 budget was shown erroneously instead of that of FY2013. The budget of FY 2014 has beenreprinted with the revised external funding.].

0
Accelerator science research

564

476

International collaboration research

2,510

RIBF construction
External Funding

FY2014

Million Yen

Million Yen
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0

External Funding
RIBF Construction Subsidy
International Collaboration Research
Accelerator Science Research

2010

2011

2012

2013

2014

- 338 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

3. Staffing
At the start of FY 2014, April 1 2014, there were 246 personnel affiliated with RNC and 347 researchers visiting RNC for research
purpose. The following graphs show a breakdown of personnel into seven categories as of April 2014, and a transition of the number of eachcategory. In the transition graph, researchers associated with the BNL collaboration in 2014 are counted as Contract Researcher.

78

Permanent Researcher

47

Fixed Term Full Time Researcher

28

BNL Collaboration

24

374

Technical staff

31

Postdoctoral Researcher

38

Junior Research Associate
External researcher

FY20141200
1000

External Reseacher
Junior Research Associate
Post Doctoral Researcher
Technical Staff
Contract Researcher
Permanent Researcher

800
600
400
200

0

2010

2011

2012

2013

2014

4. Research publication
Research results published in 2014 are roughly split into two categories, i.e., papers published in journals and oral presentations. A
transition of the number of the past five years is shown in the following graph.
1200
1000
Oral Presentations (Domestic)

800

Oral Presentations (Outside Japan)

600

Papers in Domestic Journals

400

Papers in Foreign Journals
200
0

2010

2011

2012

2013

- 339 -

2014

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

5. Management
Headed by the RNC Director Hideto En'yo, the RIKEN Nishina Center for Accelerator-Based Science (RNC) consists of:
10 Laboratories
1 Research unit
9 Groups with 25 Teams
2 overseas research center with 3 Groups
as of the latter half of FY2014. There are also three 'Partner Institutes' which conduct research in the laboratories set up in RNC.
RNC is managed by its Director who takes into consideration the majority decision of the RNC Coordination Committee. The Nishina
Center Planning Office under the auspices of President of RIKEN is responsible for administrative matters of RNC.
The management of RNC is supported by the following committees:
Scientific Policy Committee
Program Advisory Committee
Safety Review Committee
RIBF Machine Time Committee
Public Relations Committee
There are also committees to support the President of RIKEN and/or the Director of RNC such as:
RBRC Management Steering Committee (MSC) and Nishina Center Advisory Council with two subcommittees,
RBRC Management Steering Committee (MSC) andNishina Center Advisory Council with two subcommittees,
RBRC Scientific Review Committee (SRC) andAdvisory Committee for the RIKEN-RAL Muon Facility

Nishina Center for Accelerator-based Science
Executive Members (as of March 31, 2015)
Hideto EN'YO
Director RNC; Chief Scientist, Director of Radiation Laboratory
Tetsuo HATSUDA
Deputy Director (Theoretical Research), RNC; Chief Scientist, Director of Quantum Hadron Physics Laboratory
Hiroyoshi SAKURAI
Deputy Director (RIBF Research), RNC; Chief Scientist, Director of Radioactive Isotope Physics Laboratory;
Group Director, Nuclear Transmutation Data Research Group
Tohru MOTOBAYASHIRIBF Synergetic-Use Coordinator
Walter F. HENNING
Senior Advisor
Yasushige YANO
Senior Advisor
Minami IMANISHI
Assistant

RNC Coordination Committee
The following subjects relevant to the RNC management are deliberated under the chairmanship of the RNC Director:
Establishment of the new organization or reorganization in RNC
Personnel management of RNC researchers
Research themes and research budget
Approval of the Partner Institutes
Evaluation of the management of RNC and the response to the recommendations by external evaluation
The RNC Coordination Committee is held monthly.
Members (as of March 31, 2015)
Hideto EN'YO
Hiroyoshi SAKURAI
Tetsuo HATSUDA
Tohru MOTOBAYASHI
Walter F. HENNING
Yasushige YANO
Masahiko IWASAKI
Tomohiro UESAKA
Hideki UENO
Toru TAMAGAWA
Takashi NAKATSUKASA
Emiko HIYAMA
Koji HASHIMOTO
Kosuke MORITA
Osamu KAMIGAITO

Director, RNC; Chief Scientist, Director of Radiation Laboratory
Deputy Director, RNC; Chief Scientist, Director of Radioactive Isotope Physics Laboratory; Group Director,
Nuclear Transmutation Data Research Group
Deputy Director, RNC; Chief Scientist, Director of Quantum Hadron Physics Laboratory
RIBF Synergetic-Use Coordinator
Senior Advisor
Senior Advisor
Chief Scientist, Director of Advanced Meson Science Laboratory
Chief Scientist, Director of Spin isospin Laboratory
Chief Scientist, Director of Nuclear Spectroscopy Laboratory; Deputy Group Director, User Liaison andIndustrial Cooperation Group
Associate Chief Scientist, Director of High Energy Astrophysics Laboratory
Associate Chief Scientist, Director of Theoretical Nuclear Physics Laboratory
Associate Chief Scientist, Director of Strangeness Nuclear Physics Laboratory
Associate Chief Scientist, Director of Mathematical Physics Laboratory
Group Director, Research Group for Superheavy Element; Team Leader, Superheavy Element Production TeamGroup Director, Accelerator Group; Group Director, High-Intensity Accelerator E&D Group- 340 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Hideyuki SAKAI
Hiroki OKUNOGroup Director, User Liaison and Industrial Cooperation Group
Deputy Group Director, Accelerator Group; Team Leader, Accelerator R&D Team; Team Leader,
Cryogenic Technology Team; Team Leader, High-Power Target R&D Team
Deputy Group Director, Accelerator Group; Team Leader, Beam Dynamics & Diagnostics Team
Deputy Group Director, Accelerator Group; Team Leader, Infrastructure Management TeamGroup Director, Accelerator Applications Research Group; Team Leader, Radiation Biology TeamGroup Director, Safety Management Group
Group Director, Research Instruments Group; Team Leader, Detector TeamGroup Director, Instrumentation Development Group; Team Leader, Rare RI-ring Team; Team Leader, SCRIT Team
Team Leader, RILAC Team
Team Leader, Computing and Network Team
Team Leader, Cyclotron Team; Team Leader, High-Gradient Cavity R&D Team
Team Leader, Detector Team
Team Leader, Ion Source Team
Team Leader, RI Applications Team
Team Leader, Superheavy Element Device Development Team
Team Leader, Industrial Cooperation Team
Team Leader, BigRIPS Team; Team Leader, Slow RI Data Team
Team Leader, User Support OfficeTeam Leader, SLOWRI Team
Team Leader, SAMURAI Team; Team Leader, Fast RI Data Team
Team Leader, Muon Data Team
Vice Chief Scientist; Group Leader, Experimental Group, RIKEN BNL Research Center
Vice Chief Scientist, Advanced Meson Science Laboratory
Vice Chief Scientist, Quantum Hadron Physics Laboratory
Research Unit Leader, Astro-Glaciology Research Unit
Deputy Director, Nishina Center Planning OfficeNobuhisa FUKUNISHI
Masayuki KASE
Tomoko ABE
Yoshitomo UWAMINO
Toshiyuki KUBO
Masanori WAKASUGIEiji IKEZAWA
Takashi ICHIHARA
Naruhiko SAKAMOTO
Hiromi SATO
Takahide NAKAGAWA
Hiromitsu HABA
Koji MORIMOTO
Atsushi YOSHIDA
Koichi YOSHIDA
Ken-ichiro YONEDA
Michiharu WADA
Hideaki OTSU
Teiichiro MATSUZAKI
Yasuyuki AKIBA
Katsuhiko ISHIDA
Tsukasa TADA
Yuko MOTIZUKI
Mitsuru KISHIMOTO

Nishina Center Planning Office
The Nishina Center Planning Office is responsible for the following:
Planning and coordination of RNC’s research program and system
Planning and management of RNC’s use of budget
Public relations activities
Members (as of March 31, 2015)
Hiroshi TSUBOI
Mitsuru KISHIMOTO
Kazunori MABUCHI
Yasutaka AKAI
Yukari ONISHI
Kumiko SUGITA
Yuko OKADA
Yukiko SATO
Kyoji YAMADA
Yoshio OKUIZUMIMasatoshi MORIYAMA
Rie KUWANA

Executive Director; Director, Head of Nishina Center Planning Office
Deputy Director, Nishina Center Planning Office; Administration Manager, RBRC; Administration Manager,
RIKEN Facility Office at RAL
Deputy Manager, Nishina Center Planning Office
Administrative Officer of Nishina Center Planning Office; Deputy Administration Manager, RBRC
Chief, Nishina Center Planning OfficeSpecial Administrative Employee
Task-Specific Employee
Task-Specific Employee
Special Temporary Employee
Temporary Employee
Consultant for Advisory Committee, Research Review, etc.
Temporary Staff

Scientific Policy Committee
The Scientific Policy Committee deliberates on the following:
Research measures and policies of RNC
Administration of research facilities under RNC's management
The Committee members are selected among professionals within and outside RNC. The members were not chosen nor the Committee held in FY2014.

Program Advisory Committee
The Program Advisory Committee reviews experimental proposals submitted by researchers and reports the approval/disapproval of the proposals to
the RNC Director. The Committee also reports to the RNC Director the available days of operation at RIBF or the Muon Facility at RAL allocated to researchers.
The Committee is divided into three categories according to the research field.
(1) Nuclear Physics Experiments at RIBF (NP-PAC): academic research in nuclear physics- 341 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES(2) Materials and Life Science Researches at RNC (ML-PAC): academic research in materials science and life science(3) Industrial Program Advisory Committee (In-PAC): non-academic research
Program Advisory Committee for Nuclear Physics Experiments at RI Beam Factory (NP-PAC)
Members (as of March 31, 2015)
Muhsin N. HARAKEH (Chair)Prof., KVI (Kernfysisch Versneller Instituut), University of Groningen, Netherlands
Yanlin YE
Prof., State Key Lab. of Nucl. Phys. and Tech., School of Physics, Peking University, China
Christoph SCHEIDENBERGER
Head, NuSTAR/ENNA Department, GSI, Germany
Friedrich-K. THIELEMANN
Prof., Department of Physics, University of Basel, Switzerland
Rick F. CASTEN
Prof., Department of Physics, Yale University, USA
Christopher J. (KIM) LISTER
Prof., Department of Physics and Applied Physics, University of Massachusetts, Lowell, USA
Hans EMLING
Prof. Dr., GSI, Germany
Hironori IWASAKI
Assistant Prof., National Superconducting Cyclotron Laboratory, Michigan State University, USA
Walter D. LOVELAND
Full Prof., Department of Chemistry, Oregon State University, USA
Thomas NILSSON
Prof., Chalmers Univ. of Technology, Sweden; Chair of BFC (Board of FAIR Collaborations)Bradley. M.SHERRILL
FRIB Associate Laboratory Director for Users, Michigan State University, USA
Olivier SORLINGANIL (Grand Accélérateur National d’Ions Lourds), France
Satoshi N. NAKAMURA
Prof. Nuclear Experiment Group, Faculty of Science, Tohoku University, Japan
Atsushi TAMII
Associate Prof., Research Center for Nuclear Physics, Osaka University, Japan
Yutaka UTSUNO
Senior Scientist, Advanced Science Research Center, JAEA, Japan
Masanobu YAHIRO
Prof., Faculty of Sciences, Kyushu University, Japan
Takashi NAKATSUKASA
Associate Chief Scientist, Theoretical Nuclear Physics Laboratory, RNC, Japan
Program Advisory Committee for Materials and Life Science Researches at RIKEN Nishina Center (ML-PAC)
Members (as of March 31, 2015)
Jean-Michel POUTISSOU (Chair)
Senior research scientist Emeritus, TRIUMF, Canada
Alex AMATO
Bulk μSR Group Head, GPS Scientist, Laboratory for Muon Spin Spectroscopy, PSI, Switzerland
Douglas E. MACLAUGHLIN
Prof., Emeritus, University of California, Riverside, USA
Sadamichi MAEKAWA
Director General, Advanced Science Research Center, JAEA, Japan
Kenya KUBO
Prof., Department of Material Science, International Christian University, Japan
Adrian HILLIER
ISIS, RAL, UK
Philippe MENDELS
Prof., Laboratorie de Physique des Solides, Universite Paris-SUD, France
Xu-Guang ZHENG
Prof., Department of Physics Faculty of Science and Engineering, Saga University, Japan
Hiroyuki YAMASE
Senior Researcher, National Institute for Materials Science, Japan
Ryosuke KADONO
Prof., Division Head, Muon Science Laboratory, Institute of Materials Structure Science, KEK, Japan
Norimichi KOJIMA
Prof., Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Japan
Toshiyuki AZUMA
Chief Scientist, Atomic, Molecular & Optical Physics Laboratory, RIKEN, Japan
Atsushi KAWAMOTO
Prof., Graduate School of Science, Hokkaido University, JAPAN
Shigeo YOSHIDA
Research Consultant, RIKEN Center for Sustainable Resource Science, RIKEN, Japan
Industrial Program Advisory Committee (In-PAC)
Members (as of March 31, 2015)
Akihiro IWASE (Chair)Prof., Graduate School of Engineering, Osaka Prefecture University, Japan
Kenya KUBO
Prof., The College of Liberal Arts, International Christian University, Japan
Hitoshi NAKAGAWA
Auditor, Japan International Research Center for Agricultural Sciences, Japan
Nobuhiko NISHIDA
Full time research fellow, Toyota Physical and Chemical Research Institute, Japan
Toshinori MITSUMOTO
Chief Engineer, Quantum Equipment Division, Sumitomo Heavy Industries, Ltd, Japan
Toshiyuki AZUMA
Chief Scientist, Atomic, Molecular & Optical Physics Laboratory, RIKEN, Japan

Safety Review Committee
The Safety Review Committee is composed of two sub committees, the Safety Review Committee for Accelerator Experiments and the Hot-Lab Safety
Review Committee. These Committees review the safety regarding the usage of radiation generating equipment based on the proposal submitted to RNC
Director from the spokesperson of the approved experiment.
Safety Review Committee for Accelerator Experiments
Members (as of March 31, 2015)
Takashi KISHIDA (Chair)
Senior Research Scientist, Radioactive Isotope Physics Laboratory
Kouji MORIMOTOTeam Leader, Superheavy Element Device Development Team
Eiji IKEZAWA
Team Leader, RILAC Team
Hiromitsu HABATeam Leader, RI Applications Team
Shinichiro MICHIMASA
Assistant Prof., Center for Nuclear Study, University of Tokyo
Hidetoshi YAMAGUCHI
Lecturer, Center for Nuclear Study, University of Tokyo
Hiroshi WATANABE
Lecturer, Radioactive Nuclear Beam Group, IPNS, KEK- 342 -

Ⅵ. RNC ACTIVITIESHiromi SATO
Atsushi YOSHIDA
Koichi YOSHIDA
Naoki FUKUDA
Naruhiko SAKAMOTO
Ex officio members
Yoshitomo UWAMINO
Kanenobu TANAKA
Hisao SAKAMOTO
Hot-Lab Safety Review Committee
Members (as of March 31, 2015)
Masako IZUMI (Chair)
Hiromitsu HABA
Yoshitomo UWAMINO
Kanenobu TANAKA
Hisao SAKAMOTO
Hiroki MUKAIRIKEN Accel. Prog. Rep. 48 (2015)

Team Leader, Detector Team
Team Leader, Industrial Cooperation Team
Team Leader, BigRIPS Team
Nishina Center Research Scientist, BigRIPS Team
Team Leader, Cyclotron TeamGroup Director, Safety Management Group
Deputy Group Director, Management Group
Nishina Center Technical Scientist, Safety Management Group

Senior Research Scientist, Radiation Biology Team
Team Leader, RI Applications TeamGroup Director, Safety Management Group
Deputy Group Director, Safety Management Group
Nishina Center Technical Scientist, Safety Management Group
Assigned Employee, Safety Management GroupRIBF Machine Time Committee
Upon request of the RNC Director, the RIBF Machine Time Committee deliberates on the machine time schedule of RIBF, and reports the results to him.
Members (as of March 31, 2015)
Hideyuki SAKAI (Chair)
Tomoko ABE
Nobuhisa FUKUNISHI
Osamu KAMIGAITO
Masayuki KASE
Toshiyuki KUBO
Kouji MORIMOTO
Hiroki OKUNO
Hiroyoshi SAKURAI
Hideki UENO
Tomohiro UESAKA
Yoshitomo UWAMINO
Masanori WAKASUGI
Ken-ichiro YONEDA
Susumu SHIMOURA
Hidetoshi YAMAGUCHI
Hiroari MIYATAKE
Observers (as of March 31, 2015)
Hideto EN'YO
Nobuaki IMAI
Hiromitsu HABA
Kosuke MORITA
Tohru MOTOBAYASHI
Koichi YOSHIDA
Kanenobu TANAKA
Mitsuru KISHIMOTOGroup Director, User Liaison and Industrial Cooperation Group
Group Director, Accelerator Applications Research Group
Deputy Group Director, Accelerator Group
Group Director, Accelerator Group
Deputy Group Director, Accelerator Group
Group Director, Research Instruments GroupTeam Leader, Superheavy Element Research Device Development Team
Deputy Group Director, Accelerator Group
Chief Scientist, Radioactive Isotope Physics Laboratory
Chief Scientist, Nuclear Spectroscopy Laboratory
Chief Scientist, Spin isospin Laboratory
Group Director, Safety Management Group
Group Director, Instrumentation Development GroupTeam Leader, User Support Office
Professor, Center for Nuclear Study, University of Tokyo
Lecturer, Center for Nuclear Study, University of Tokyo
Professor, Radioactive Nuclear Beam Group, IPNS, KEK
Director, RNC
Chair, RIBF-UEC, Associate Prof. Center for Nuclear Study, University of Tokyo
Team Leader, RI Applications TeamGroup Director, Research Group for Superheavy Element
RIBF Synergetic-Use Coordinator
Team Leader, BigRIPS Team; Team Leader, Slow RI Data Team
Deputy Group Director, Safety Management Group
Deputy Director, Nishina Center Planning OfficePublic Relations Committee
Upon request of the RNC Director, the Public Relations Committee deliberates and coordinates the following matters:(1) Creating public relations system for the RNC(2) Prioritization of the public relations activities for the RNC(3) Other general and important matters concerning the public relations of RNC
Members (as of March 31, 2015)
Hiroshi TSUBOI
Hiroyoshi SAKURAI
Tetsuo HATSUDA
Tohru MOTOBAYASHI
Walter F. HENNING
Yasushige YANO

Executive Director; Director, Head of Nishina Center Planning Office
Deputy Director, RNC; Chief Scientist, Radioactive Isotope Physics Laboratory
Deputy Director, RNC; Chief Scientist, Quantum Hadron Physics Laboratory
RIBF synergetic-use coordinator
Senior Advisor
Senior Advisor- 343 -

RIKEN Accel. Prog. Rep. 48 (2015)

Masahiko IWASAKI
Tomohiro UESAKA
Hideki UENO
Toru TAMAGAWA
Takashi NAKATSUKASA
Emiko HIYAMA
Koji HASHIMOTO
Kosuke MORITA
Osamu KAMIGAITO
Hideyuki SAKAI

Ⅵ. RNC ACTIVITIES

Chief Scientist, Advanced Meson Science Laboratory
Chief Scientist, Spin isospin Laboratory
Chief Scientist, Nuclear Spectroscopy Laboratory
Associate Chief Scientist, High Energy Astrophysics Laboratory
Associate Chief Scientist, Theoretical Nuclear Physics Laboratory
Associate Chief Scientist, Strangeness Nuclear Physics Laboratory
Associate Chief Scientist, Mathematical Physics Laboratory
Group Director, Research Group for Superheavy Element
Group Director, Accelerator Group
Group Director, User Liaison and Industrial Cooperation Group

RBRC Management Steering Committee (MSC)
RBRC MSC is set up according to the Memorandum of Understanding between RIKEN and BNL concerning the collaboration on the Spin Physics
Program at the Relativistic Heavy Ion Collider (RHIC).
Members (as of March 31, 2015)
Maki KAWAI
Shoji NAGAMIYA
Hideto EN'YO
Berndt MUELLERDavid LISSAUER
Satoshi OZAKI

Executive Director, RIKEN
Science Advisor, RIKEN
Director, RNC
Associate Laboratory Director for Nuclear and Particle Physics, BNL
Deputy Chair, Physics Department, BNL
Senior Advisor, BNL

Nishina Center Advisory Council
The agenda to be deliberated by NCAC are set by the Terms of Reference presented by the RNC Director on the fundamental issues regarding research
activities and administrative matters. NCAC submits its report to the President of RIKEN, and to the Director of Nishina Center if necessary. The members of
NCAC are recommended by the Director of the Nishina Center to the President of RIKEN and selected from among highly knowledgeable individuals andexperts worldwide. NCAC has two sub-councils for the RBRC and the RAL Muon Facility, respectively.
Members (as of March 31, 2015)
Robert TRIBBLE (Chair)
Hirokazu TAMURA
Muhsin N. HARAKEH
Jean-Michel POUTISSOU
Richard MILNER
Andrew TAYLOR
Juha ÄYSTÖAngela BRACCO
Masaki FUKUSHIMA
Ken'ichi IMAI
Marek LEWITOWICZ
Lia MERMINGA
Witold NAZAREWICZ
Susumu SHIMOURA
Matthias SCHÄDEL
Jun SUGIYAMA
Wolfram WEISE
GuoQing XIAO
Akira YAMAMOTO

Deputy Director for Science and Technology, BNL, USA
Prof., Department of Physics, Graduate School of Science, Tohoku University, Japan
Prof., Emeritus, KVI (Kernfysisch Versneller Instituut), University of Groningen, Netherlands; Chair, NP-PAC
Senior research scientist Emeritus, TRIUMF, Canada; Chair, ML-PAC
Prof., Director, Laboratory for Nuclear Science, MIT, USA; Chair, RBRC-SRC
Executive Director, STFC National Laboratories, UK; Chair, RAL-IAC
Director of Helsinki Institute of Physics, Finland
Prof., Department of Physics, the University of Milan, Italy
Prof., Institute for Cosmic Ray Research, University of Tokyo, Japan
Group Leader, Research Group for Hadron Physics, Advanced Science Research Center, JAEA, Japan
Deputy Director, GANIL (Grand Accélérateur National d'Ions Lourds), France
Head, Accelerator Division, TRIUMF, Canada
Prof., Department of Physics and Astronomy, the University of Tennessee, USA
Prof., Center for Nuclear Study (CNS), University of Tokyo, Japan
Group Leader, Research Group for Superheavy Elements, Advanced Science Research Center, JAEA. , Japan
Principal Research Scientist, Toyota Central R&D Labs., INC, Japan
Director, European Center for Theoretical Studies in Nuclear Physic and Related Areas, Italy
Director, Institute of Modern Physics, Chinese Academy of Sciences, China
Head, Linear Collider Project Office, Department of Advanced Accelerator Technologies, KEK, Japan

RBRC Scientific Review Committee (SRC)
Members (as of March 31, 2015)
Richard MILNER (Chair)
Shinya AOKI
Ken'ich IMAI
Tetsuo MATSUI
Alfred MUELLER
Peter Braun-MUNZINGERCharles PRESCOTT
Akira UKAWA

Prof., Director, Laboratory for Nuclear Science, MIT, USA
Prof., Yukawa Institute for Theoretical Physics, Kyoto University, Japan
Group Leader, Research Group for Hadron Physics, Advanced Science Research Center, JAEA, Japan
Prof., Department of Basic Science, Graduate School of Arts and Sciences, Komaba, University of Tokyo, Japan
Prof., Department of Physics, Columbia University, USA
Prof., Dr. GSI Helmholtzzentrum für Schwerionenforschung, Germany
Prof., Stanford Linear Accelerator Center, USA
Prof., Graduate School of Pure and Applied Science, University of Tsukuba, Japan- 344 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Advisory Committee for the RIKEN-RAL Muon Facility
Members (as of March 31, 2015)
Andrew D TAYLOR (Chair)Jean-Michel POUTISSOU
Klaus P. JUNGMANN
Roberto De RENZI
Yasuyuki MATSUDA
Jun SUGIYAMAExecutive Director, STFC National Laboratories, UK
Senior research scientist Emeritus, TRIUMF, Canada
Prof., University of Groningen, Netherlands
Prof., Department of Physics and Earth Sciences, University of Parma, Italy
Assoc. Prof., Graduate School of Arts and Sciences, the University of Tokyo, Japan
Principal Research Scientist, Toyota Central R&D Labs., INC, Japan

6. International Collaboration
Country

Partner Institute

Austria

Stefan Meyer Institute for Subatomic Physics

Belgium

Katholieke Universiteit te Leuven

Bulgaria
CanadaThe Institute for Nuclear Research and Nuclear
Energy (INRNE)
TRIUMF

China

China Nuclear Physics Society
Peking University

Objects

RNC contact person

Experimental and theoretical hadron physics,
especially in exotic hadronic atoms and mesonand baryon nuclear bound states
Framework

Masahiko IWASAKI, Chief Scientist, Director ofAdvanced Meson Science Laboratory

Framework
Accelerator-based Science
Creation of the council for China -Japan researchcollaboration on nuclear physics
Nuclear Science
Strategic cooperation (Nishina School)EU

Shanghai Jiao Tong University

International Joint Graduate School Program

ZHEJIANG University

International Joint Graduate School Program

Institute of Modern Physics, Chinese Academyof Science
School of Nuclear Science and Technology,
Lanzhou University
School of Physics, Nanjing University

Physics of heavy ions

European Gamma-Ray Spectroscopy Pool
Owners Committee
European Center for Theoretical Studies in
Nuclear Physics and Related Areas (ECT*)CERN

The use of Euroball ditector at RIKEN

ALICE Collaboration
GSI & Reaction with Relativistic Radioactive
Beams (R3B) Collaboration

Finland

University of Jyvaskyla

FranceNational Institute of Nuclear Physics and Particle
Physics ( IN2P3)
CNRS, CEA,GANIL, Université Paris Sud, etc.

IRFU CEA-Saclay DSM/IRFU, IPNO CNRS
IN2P3, GANIL
CEA-DSMSIMEM Graduate School, Department of
Physics, Caen University
Université de Caen Basse Normandie

Framework
Framework

Theoretical physics
Framework
RD-51:R&D programme for micro-pattern gas
detectors (MPGD)
Development of Gas Electron Multiplier, Silicon
Detectors, etc.
To unravel structure of nuclei in the vicinity ofand beyond the neutron dripline throughexperiments with the NeuLAND detector
combined with the SAMURAI magnetic
spectrometer at the RIBF
Basic nuclear physics and related instrumentation
Physics of heavy ions
Creation of an International AssociatedLaboratory (LIA)
French-Japanese International AssociatedLaboratory for Nuclear Structure Problems
The preparation and realization for the MUST2
campaign of experiments at RIKEN
The use of MINOS device at RIKEN
Framework
International Joint Graduate School Program- 345 -

Michiharu WADA, Team Leader, SLOWRITeam
Hedeki UENO, Chief Scientist, Nuclear
Spectroscopy Laboratory
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Takashi NAKATSUKASA, Associate chief
scientist, Theoretical Nuclear Physics Laboratory
Isao WATANABE, Advanced Meson Science
Laboratoy
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Yue MA, Advanced Meson Science Laboratory
Emiko HIYAMA, Associate chief scientist,
Strangeness Nuclear Physics Laboratory
Shunji NISHIMURA, Radioactive Isotope
Physics Laboratory
Tetsuo HATSUDA, Deputy Director, Chief
Scientist, Quantum Hadron Physics Laboratory
Satoshi YOKKAICHI, Senior Research Scientist,
Radiation Laboratory
Satoshi YOKKAICHI, Senior Research Scientist,
Radiation Laboratory
Satoshi YOKKAICHI, Senior Research Scientist,
Radiation Laboratory
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory

Michiharu WADA, Team Leader, SLOWRI
Team
Tohru MOTOBAYASHI, RIBF synergetic-use
coordinator
Tohru MOTOBAYASHI, RIBF synergetic-use
coordinator
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory

RIKEN Accel. Prog. Rep. 48 (2015)

Country
Germany

Hungary
Indonesia

Ⅵ. RNC ACTIVITIESPartner InstituteTechnische Universität München

Objects

Max-Planck Gesellschaft

Nuclear physics, hadron physics, nuclear
astrophysics
Comprehensive agreement

GSI

Physics of heavey ions and accelerator

The Institute of Nuclear Research of the
Hungarian Academy of Sciences (ATOMKI)
ITB, UNPAD, ITS, UGM

Nuclear physics, Atomic Physics

UNPAD

Material science using muons at the RIKENRAL muon facility
International Joint Graduate School Program

Institut Teknologi Bandung (ITB)

International Joint Graduate School Program

Universitas Hasanuddin

Agricultural science and related fields involving
heavy-ion beam mutagenesis using Indonesiancrops
Physics of heavy ions

Italy

National Institute of Nuclear Physics (INFN)

Korea

Applied Physics Division, National Institute for
New Technologies, Energy and Environment(ENEA)
Seoul National University

Framework

Tohru MOTOBAYASHI, RIBF synergetic-use
coordinator
Tohru MOTOBAYASHI, RIBF synergetic-use
coordinatorInternational Joint Graduate School Program

Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Itaru NAKAGAWA, Radiation Laboratory

Institute of Basic Science, Rare Isotope Science
Project
Department of Physics, Kyungpook National
University
College of Natural Sciences of Kyungpook
National University
College of Science, Yonsei University

Rare ion accelerator and related fields

Hiroyoshi SAKURAI, Shunji NISHIMURA

Framework

Department of Physics, Yonsei University

International Joint Graduate School Program

Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Yasuyuki AKIBA, Radiation Laboratory

Department of Physics, Korea University

Framework

Yuji GOTO, Radiation Laboratory

College of Natural Science, Ewha Women’s
University
Universiti Sains Malaysia

Framework

the Henryk Niewodniczanski Institute of Nuclear
Physics, Polish Academy of Sciences(IFJ PAN)
“Horia Hulubei” National Institute of Physics
and Nuclear Engineering Bucharest-Magurele,
Romania
Joint Institute for Nuclear Research (JINR)

Framework

Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Isao WATANABE, Advanced Meson Science
Laboratoy
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory

Russian Research Center “Kurchatov Institute”

Framework

Switzerland

Paul Scherrer Institute

UK

The Science and Technology Facilities Council

Improve the performance and reliability ofaccelerator systems
Muon science using the ISIS Facility at the
Rutherford Appleton Laboratory
International Joint Graduate School Program

Malaysia
PolandRomania
RussiaUniversity of Liverpool
USA

BNL

Nishina School

RNC contact person
Emiko HIYAMA, Associate chief scientist,
Strangeness Nuclear Physics Laboratory
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Isao WATANABE, Advanced Meson Science
Laboratoy
Isao WATANABE, Advanced Meson Science
Laboratoy
Isao WATANABE, Advanced Meson Science
Laboratoy
Tomoko ABE, Group Director, Accelerator
Applications Research GroupInternational Joint Graduate School Program
Framework

Framework on Muon Science

Framework
Framework

Columbia University

The Spin Physics Program at the Relativistic
Heavy Ion Collider(RHIC)
The development of QCDCQMichigan State University

Framework
TPC(Time Projection Chamber)

VietnamVietnam Atomic Energy Commission

Framework

Hanoi University of Science

International Joint Graduate School Program

Institute of Physics, Vietnam Academy of
Science and Technology

Framework- 346 -Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Hiroyoshi SAKURAI, Tomohiro UESAKA,
Osamu KAMIGAITO, Masanori WAKASUGIOsamu KAMIGAITO, Director, Chief Scientist,
Accelerator Group
Philip KING, Director of RIKEN-RAL muon
facility
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Hideto EN'YO, Director of RNC
Taku IZUBUCHI, Group Leader, Computing
Group, RBRC
Tomohiro UESAKA, Chief Scientist, Spin
Isospin Laboratory
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory& Tadaaki ISOBE, Radioactive Isotope Physics
Laboratory
Tohru MOTOBAYASHI, RIBF synergetic-use
coordinator
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory
Hiroyoshi SAKURAI, Deputy Director, Chief
Scientist, Radioactive Isotope Physics Laboratory

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

7. Awards
Awardee, Laboratory / TeamAward

Tetsuo HATSUDA, Quantum Hadron Physics Laboratory
Shinya AOKI (Visiting Scientist), Quantum Hadron Physics Laboratory
Noriyoshi ISHII (Visiting Scientist), Radiation Laboratory

The Prizes for Science and Technology in
Research Category, in the FY2015
Commendation for Science and Technology

The Minister of Education, culture,
Sports, Science and Technology(MEXT)

Apr. 15

Tomonari HIRANO, Ion Beam Breeding Team
Yusuke KAZAMA, Ion Beam Breeding Team
Kotaro ISHII, Ion Beam Breeding Team
Sumie OHBU, Ion Beam Breeding Team
Yuki SHIRAKAWA, Ion Beam Breeding Team
Tomoko ABE, Ion Beam Breeding TeamThe Outstanding Presentation Award fortheir research at the 125th Meeting of theJapanese Society of Breeding

Japanese Society of Breeding

May 14Maeyama TAKUYA, Beam Dynamics &Diagnostics Team

Young Scientist Award

The 5th Asia Pacific Symposium on
Radiation Chemistry (APSRC2014)

Sep. 11

Yuko MOTIZUKI, the Astro-Glaciology Research Unit

NIceSTEP Award

National Institute of Science andTechnology Policy

Dec. 19

Kimiko SEKIGUCHI (Visiting Scientist) ,Spin Isospin Laboratory

The silver prize of the 2nd Yuasa Prize

Ochanomizu University

Dec. 24

Yoichi IKEDA, Quantum Hadron Physics Laboratory
Toru SATO (Visiting Scientist), Strangeness Nuclear Physics Laboratory

The 20th Best Paper Award

The Physical Society of Japan

Mar. 23

Aiko TAKAMINE (Visiting Scientist) , SLOWRI TeamThe 9th Young Scientist Award in the fieldof experimental nuclear physics

The Physical Society of Japan

Mar. 21

Abhay DESHPANDE, RBRC experimental group

Appointment as an APS Fellow

The American Physical Society

Mar. 13

8. Brief overview of the RI Beam Factory
Intensity of Primary Beams

Achieved beam intensities (as of March 2015)
238

U
Xe
86
Kr
70
Zn
48
Ca
18
O
14
N
4
He
d
pol. d124

28 pnA
38 pnA
30 pnA123 pnA
530 pnA
1,000 pnA
400 pnA
1,000 pnA
1,000 pnA
1,000 pnA

(345 MeV/u, Oct. 2014)(345 MeV/u, Jun. 2013)(345 MeV/u, Nov. 2007)(345 MeV/u, Jun. 2014)(345 MeV/u, Nov. 2014)(345 MeV/u, Jun. 2010)(250 MeV/u, Oct. 2010)(250 MeV/u, Oct. 2009)(250 MeV/u, Oct. 2010)(250 MeV/u, Apr. 2009)- 347 -

Organization

Date

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESHistory of Beam Intensity Upgrade

1000

320A MeV 4He

18O

294A MeV 18O

48Ca

(pnA)

100

10

Air stripper (2nd stage)

70Zn

86Kr

124Xe

28-GHz SC-ECRISRILAC2

Variable energy

Helium gas stripper (1st stage)
Rotating beryllium stripper (2ndstage)
fRC upgrade
90 μA @ 28-GHz SC-ECRISFixed energy
1

0.1
2007

238U

AVF injection

2008

18-GHzECRIS@RILAC

2009

2010

2011 2012(year)

2013

2014

2015

CNT-based foil (1st stage)
28 μA @ 28-GHz SC-ECRISSC-ECRIS with the existing 18-GHz klystron@RILAC (testoperation)

Total beam time for experiments
400.0
350.0
300.0
250.0

days

Machine StudyRNC Enterprise

200.0

Industrial use
Material & Life

150.0

Nuclear Physics

100.0
50.0
0.0

2007

2008

2009

2010

2011

Fiscal year

- 348 -

2012

2013

2014

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Breakdown of Nucl. Phys. Expts.
300.0

250.0

200.0

RILAC/GARIS

days

AVF/CRIB
RRC/RIPS

150.0

SRC/BigRIPS

100.0

50.0

0.0

2007

2008

2009

2010

2011

2012

2013

2014

Fiscal year

Total beam time allocated to BigRIPS experiments
160

Total (Data run + MS + Tuning)

PAC‐approved experiments

140

Beam Time (days)

120
100
80
60
40
20
0
2007

2008

2009

2010

2011

Fiscal Year- 349 -

2012

2013

2014

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESTheoretical Research Division
Quantum Hadron Physics Laboratory
1. Abstract

Atomic nuclei are made of protons and neutrons bound by the exchange of Yukawa's pion and other mesons. Also, protons andneutrons are made of quarks bound by the exchange of gluons. These strong interactions are governed by the non-Abelian gauge theory
called the quantum chromodynamics (QCD). On the basis of theoretical and numerical analyses of QCD, we study the interactions between
the nucleons, properties of the dense quark matter realized at the center of neutron stars, and properties of the hot quark-gluon plasma
realized in the early Universe. Strong correlations common in QCD and cold atoms are also studied theoretically to unravel the universal
features of the strongly interacting many-body systems. Developing perturbative and non-perturbative techniques in quantum field theory
and string theory are of great importance not only to solve gauge theories such as QED and QCD, but also to find the theories beyond thestandard model of elementary particles. Various theoretical approaches along this line have been attempted.

2. Major Research Subjects(1) Improving the tenth-order QED contribution to the electron g−2(2) Physics of particles with resonant interactions(3) String duality and Sine-Square Deformation of Conformal Field Theory(4) Theory of spontaneous symmetry breaking(5) QCD under extreme conditions(6) Lattice baryon forces

3. Summary of Research Activity(1) Improving the tenth-order QED contribution to the electron g−𝟐𝟐𝟐𝟐
The preliminary value of the tenth-order of the perturbation theory of QED contribution to the electron anomalous magnetic
moment (g−2) was reported by us in 2012. Since then, we have been involved in improving and establishing its accuracy. To carry out it,
we reevaluated the most difficult and large set of the Feynman diagrams by using the advanced technique of numerical calculation
especially suitable to RIKEN’s supercomputer. As a result, we have obtained more reliable and more precise values for the eighth- andtenth-order terms. Together with the Harvard experiment of the electron g−2, it leads to the world-best value of the fine-structure constant
α that will be used to determine a next CODATA recommended value of α.
(2) Physics of particles with resonant interactions
Some particles, such as nucleons, can only weakly or nearly bind by pair. As a result, their pairwise interaction is resonant.
Resonant interactions induce universal few-body phenomena, such as the Efimov effect. These phenomena lead to the existence ofuniversal three-body bound states, that can be easily investigated with ultra-cold atoms. After analysing these experiments and clarifying
these few-body phenomena for the past few years, we have now started to explore their consequences at the many-body level, by firstlooking at mixtures of resonantly interacting heavy and light particles. The near-resonant interaction induces a phase made of trimers of two
heavy and one light particles. We have characterized this phase by carrying out for the first time a six-body calculation of the effective
interaction between two universal trimers.
(3) String duality and Sine-Square Deformation of Conformal Field Theory
String duality is the concept that has been leading us to better understandings of the dynamics of string theory. One of suchdualities is the open-closed duality, which suggests relation between gauge theories and the theory of gravity, thus could be behind anotherduality, AdS/CFT correspondence. Since the difference between open string and closed string is the difference of the boundary condition of
the worldsheet of string, of particular interest is the recently found phenomenon called Sine-Square Deformation (SSD) in which certain
quantum systems exhibit the change from the closed-boundary vacuums to open-boundary ones through the spatial modulation of thecouplings. We investigated SSD in the context of Conformal Field Theory (CFT) in particular and found continuous Virasoro algebra,
suggesting that CFT would acquire a continuous energy spectrum under SSD.
(4) Theory of spontaneous symmetry breaking(4-1) Dispersion relations of Nambu-Goldstone modes at finite temperature and density
We discussed the dispersion relations of Nambu-Goldstone (NG) modes associated with spontaneous breaking of internal
symmetries at finite temperature and/or density. We showed that the dispersion relations of type-A (I) and type-B (II) NG modes are linear
and quadratic in momentum, whose imaginary parts are quadratic and quartic, respectively. In both cases, the real parts of the dispersion
relations are larger than the imaginary parts when the momentum is small, so that the NG modes can propagate far away. We derived thegap formula for NG modes in the presence of a small explicit breaking term. We also discussed the gapped partners of type-B NG modes,
when type-A and type-B NG modes coexisted.
(4-2) Effective field theory for spacetime symmetry breaking
We discussed the effective field theory for spacetime symmetry breaking from the local symmetry point of view. By gauging
spacetime symmetries, the identification of Nambu-Goldstone (NG) fields and the construction of the effective action were performed
based on the breaking pattern of diffeomorphism, local Lorentz, and (an)isotropic Weyl symmetries as well as the internal symmetries
including possible central extensions in nonrelativistic systems. Such a local picture distinguishes, e.g., whether the symmetry breaking
condensations have spins and provides a correct identification of the physical NG fields, while the standard coset construction based on
global symmetry breaking does not. We illustrated that the local picture becomes important in particular when we took into account- 350 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

massive modes associated with symmetry breaking, whose masses were not necessarily high. We also revisited the coset construction forspacetime symmetry breaking. Based on the relation between the Maurer-Cartan one form and connections for spacetime symmetries, weclassified the physical meanings of the inverse Higgs constraints by the coordinate dimension of broken symmetries. Inverse Higgs
constraints for spacetime symmetries with a higher dimension remove the redundant NG fields, whereas those for dimensionlesssymmetries can be further classified by the local symmetry breaking pattern.
(5) QCD under extreme conditions(5-1) Production and Elliptic Flow of Dileptons and Photons in the semi-Quark Gluon Plasma
We considered the thermal production of dileptons and photons at temperatures above the critical temperature in QCD. We useda model where color excitations are suppressed by a small value of the Polyakov loop, the semi Quark-Gluon Plasma (QGP). Comparing
the semi-QGP to the perturbative QGP, we found a mild enhancement of thermal dileptons. In contrast, to leading logarithmic order in weakcoupling there are far fewer hard photons from the semi-QGP than the usual QGP. To illustrate the possible effects on photon and dileptons
production in heavy ion collisions, we integrated the rate with a realistic hydrodynamic simulation. Dileptons uniformly exhibit a small
flow, but the strong suppression of photons in the semi-QGP tends to bias the elliptical flow of photons to that generated in the hadronic
phase.
(5-2) Relativistic hydrodynamics from quantum field theory on the basis of the generalized Gibbs ensemble method
We derived relativistic hydrodynamics from quantum field theories by assuming that the density operator is given by a local
Gibbs distribution at initial time. We decomposed the energy-momentum tensor and particle current into nondissipative and dissipative
parts, and analyzed their time-evolution in detail. Performing the path-integral formulation of the local Gibbs distribution, we
microscopically derived the generating functional for the nondissipative hydrodynamics. We also constructed a basis to study dissipative
corrections. In particular, we derived the first-order dissipative hydrodynamic equations without choice of frame such as theLandau-Lifshitz or Eckart frame.
(6) Lattice baryon forces
One of the most important subjects in nuclear physics is to determine nuclear forces and hyperon forces, or generalized baryon
forces, directly based on the fundamental theory, QCD. In HAL QCD Collaboration, we have been developing a novel lattice QCD
formulation and performing first-principles numerical simulations to determine baryon forces. Spin-orbit forces have been calculated forthe first time, and attraction in 3P2 channel is observed, which is related to the P-wave neutron pairing in neutron stars. The calculation of
the N-Omega interaction shows that the system is bound in 5S2 channel. Three-nucleon forces have been calculated at several heavy quark
masses, and quark mass dependence is found to be small. The lattice calculations are extended to the the exotic tetraquark systems as Tcc
and Tcs, and the phenomenological diquark picture in these systems is studied as well. As an application, properties of medium-heavy
nuclei have been calculated based on lattice nuclear forces, and so-called "mass-formula" is obtained.

Members
Chief Scientist (Lab. Head)
Tetsuo HATSUDA (Deputy Director, RNC)
Vice Chief Scientist
Tsukasa TADA
Research & Technical Scientists
Takumi DOI (Senior Research Scientist)
Yoshimasa HIDAKA (Senior Research Scientist)

Pascal Raphaël Gabriel NAIDON (Research Scientist)

Nishina Center Research Scientist
Makiko NIO
Special Postdoctoral Researchers
Arata YAMAMOTO (– Mar. 31, 2014)
Kanabu NAWA (– Mar. 31, 2015)
Yuji SAKAI (– Apr. 30, 2014)

Takashi SANO (– Mar. 31, 2015)
Kazuhiko KAMIKADO
Noriaki OGAWA (Apr. 1, 2014 –)Foreign Postdoctoral Researchers
Gergely Peter FEJOES

Vojtech KREJCIRIK (Apr. 1, 2014 –)Postdoctoral Researchers
Yoichi IKEDA
Koich HATTORI (Feb. 1, 2014 –)Taichi KAWANAI (– Sep. 30, 2014)

Shinsuke YOSHIDA (– Mar. 31, 2015)
Daisuke SATO (– Sep. 30, 2014)

Junior Research Associate
Masaru HONGO (Univ. of Tokyo)- 351 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESInternational Program Associate
Robert Friedrich LANG (– Feb. 12, 2012)
Visiting Scientists
Noriyoshi ISHII (Osaka Univ.)
Yoshitaka HATTA (Kyoto Univ.)
Motoi TACHIBANA (Saga Univ.)
Masashi HAYAKAWA (Nagoya Univ.)
Toichiro KINOSHITA (Cornell Univ.)
Kenji SAKAI (Univ. of Tsukuba)
Shinya AOKI (Kyoto Univ.)
Hiroshi SUZUKI (Kyushu Univ.)
Keiko MURANO (Osaka Univ.)
Daisuke KADOH (KEK)
Yuji HIRONO (Univ. of Tokyo)
Tatsuyuki TAKATSUKA (Iwate Univ.)
Hong MAO (Hangzhou Normal Univ.)
Arata YAMAMOTO (Univ. of Tokyo)

Sho OZAKI (KEK)
Takashi OKA (Univ. of Tokyo)
Keitaro NAGATA (KEK)
Takashi INOUE (Nihon Univ.)
Kazuyuki KANAYA (Univ. of Tsukuba)
Sachiko TAKEUCHI (Japan College of Social Work)
Takayuki MATSUKI (Tokyo Kasei Univ.)
Takumi IRITANI (Kyoto Univ.)
Hiroshi TOKI (Osaka Univ.)
Tetsuo MATSUI (Univ. of Tokyo)
Makoto TAKIZAWA (Showa Pharm. Univ.)
Teiji KUNIHIRO (Kyoto Univ.)
Shoichi SASAKI (Tohoku Univ.)
Masahito UEDA (Univ. of Tokyo)

Student Trainees
Bruno CHARRON (Univ. of Tokyo)
Shimpei ENDO (Univ. of Tokyo)
Yusuke HAMA (Univ. of Tokyo)
Yasuki TACHIBANA (Univ. of Tokyo)
Tomoya HAYATA (Univ. of Tokyo)
Koichi MURASE (Univ. of Tokyo)
Yuya TANIZAKI (Univ. of Tokyo)

Ryuichi KURITA (Univ. of Tokyo)
Kota MASUDA (Univ. of Tokyo)
Masanori YAMADA (Univ. of Tsukuba)
Terukazu ICHIHARA (Kyoto Univ.)
Yuta KIKUCHI (Kyoto Univ.)
Shoichiro TSUTSUI (Kyoto Univ.)

Part-time Workers
Yuki MINAMI (Oct. 1, 2014 – Mar. 31, 2015)

Kayo YAMAJI- 352 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Theoretical Research Division
Theoretical Nuclear Physics Laboratory
1. Abstract

Nuclei are finite many-particle systems composed of protons and neutrons. They are self-bound in femto-scale (10-15m) by the strong
interaction (nuclear force) whose study was pioneered by Hideki Yukawa. Uncommon properties of the nuclear force (repulsive core,spin-isospin dependence, tensor force, etc.) prevent complete microscopic studies of nuclear structure. There exist number of unsolved
problems even at present. In addition, radioactive beam facilities reveal novel aspects of unstable nuclei. We are tackling these old
problems and new issues in theoretical nuclear physics, developing new models and pursuing large-scale calculations of quantum
many-body systems. We are also strongly involved in research on other quantum many-body systems, to resolve mysteries in the quantum
physics.

2. Major Research Subjects(1) Nuclear structure and quantum reaction theories(2) First-principle calculations with the density functional theory for many Fermion systems(3) Computational nuclear physics

3. Summary of Research Activity(1) Systematic calculation of T = 1 triplets with proton-neutron-mixed energy density functionals
We have performed a systematic calculation for the T = 1 isobaric analog states (IASs) based on the Skyrme energy density functionals(EDFs) including protons-neutron (p-n) mixing. The IASs are calculated using the isocranking method. First we performed a systematic
calculation for the energies of the T = 1 triplets in the A = 10 ~ 66 region with several Skyrme parameter sets. We used the isoscalar p-n
mixed Skyrme EDFs, which are invariant under rotation in the isospin space, together with the Coulomb energy functional. The calculated
results show a systematic underestimation from the experimental data, which may be related to violation of the charge symmetry and thecharge independence of the nucleon-nucleon interaction and may imply that we need to further extend the energy functionals including
isospin breaking terms. Recently, we have started a calculation including the isospin breaking interactions.
(2) Three dimensional mesh calculations for covariant density functional theory
The covariant density functional theory has some numerical difficulties, such as variational collapse and the fermion doubling.
Because of these problems, the three-dimensional (3D) mesh calculation was impossible for a long time. In order to realize suchcalculations for the first time, we proposed in a novel and practical method to solve Dirac equations in the 3D coordinate space. The
variational collapse is prevented by employing a method based on the variational principle for the inverse of a single-particle Hamiltonian,
while for the fermion doubling, we have extended the method of Wilson fermion, which has been widely employed in lattice QCD
calculations.
Using 16O as an example, we have confirmed that our strategy provides accurate solutions for self-consistent mean-field calculations
without the influence of the negative-energy spectrum and the spurious solutions of a discretized Dirac equation. We have also shown with
24Mg and 28Si that this method is applicable to deformed solutions in the (β, γ) deformation plane. This development enables us, e.g., i) tostudy any complicated structure of nuclei with a single numerical code, ii) to compare directly the results of the relativistic models to thoseof 3D mesh calculations with the non-relativistic models, and iii) to provide reliable theoretical predictions with the relativistic models forunknown nuclei allowing symmetry-breaking solutions. It also allows a straightforward extension of the finite amplitude method within therelativistic framework for a study of nuclear excitations in deformed nuclei.
(3) Microscopic description of fusion hindrance in heavy systems
We investigate fusion hindrance in heavy systems, where the fusion probability is strongly hindered compared with that in light- andmedium-mass systems, to understand the origin of the fusion hindrance from a microscopic point of view. We employ microscopic
time-dependent Hartree-Fock (TDHF) model for the analysis. In TDHF simulations, we reasonably reproduce the extra-push energies
estimated from experimental data for heavy systems. Then, we extract nucleus-nucleus potential and energy dissipation by combining
TDHF simulations for fusion reactions with Newton equation including a dissipation term. Extracted potentials in heavy systems show
monotonic increase as the relative distance of two nuclei decreases and the disappearance of an ordinary barrier structure, which are
different from lighter systems. Using these properties, we analyze the origin of the extra-push energy and find that the contribution to
extra-push energy from the increase in potential is larger than that from dissipated energy in most systems. We conclude from our analysis
that the main origin of the fusion hindrance is dynamical increase in potential.
(4) Hidden pseudo-spin and spin symmetries and their origins in atomic nuclei
Pseudo-spin symmetry (PSS) was introduced to explain the near degeneracy between pairs of nuclear single-particle states with thequantum numbers (n-1, l+2, j=l+3/2) and (n, l, j=l+1/2). We have written a review article [arXiv:1411.6774, Phys. Rep. in press], andintended to provide a comprehensive overview on the recent progress of pseudo-spin and spin symmetries in a systematic way. Thesesymmetries were discussed in various systems and potentials: from stable nuclei to exotic nuclei, from non-confining to confining
potentials, from local to non-local potentials, from central to tensor potentials, from bound states to resonant states, from nucleon spectra to- 353 -

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Ⅵ. RNC ACTIVITIES

anti-nucleon spectra, from nucleon spectra to hyperon spectra, from spherical nuclei to deformed nuclei.
Furthermore, three of the open issues in this field were selected and discussed in detail, i.e., the perturbative nature of PSS, the puzzle
of intruder states, and the supersymmetric (SUSY) representation of PSS. For the perturbative nature of PSS, we emphasized that whether
or not the symmetry breaking behaves perturbatively depends on whether an appropriate symmetry limit is chosen and an appropriate
symmetry-breaking term is identified. As long as an appropriate symmetry limit is chosen, the nature of PSS is indeed perturbative. For the
puzzle of intruder states, we showed several different features about this puzzle. By doing that a number of “contradicting” results in theliterature for the spin (pseudo-spin) partners have been clarified in an explicit way. For the SUSY representation of PSS, we pointed out oneof the promising ways for understanding the PSS and its symmetry breaking, by combining the similarity renormalization group, the SUSY
quantum mechanics, and the perturbation theory. Meanwhile, how to apply the SUSY technique directly to the Dirac equations, which have
non-trivial scalar and vector potentials, remains an interesting and open question.
(5) "Hybrid Kurotama model" for total reaction cross sections
We have developed a new general-purpose-total-reaction-cross-section model/subroutine called ``Hybrid Kurotama". The model has
been tested and compared with available data for p+He, p+nucleus, and nucleus+nucleus total reaction cross sections. The overall
agreement has been found better than former published models. This model is therefore very suitable to be used in any deterministic orMonte Carlo particle and heavy ion transport code.
(6) Improved parametrization of the transparency parameter in Kox and Shen models of total reaction cross sections
The total reaction cross section is an essential quantity in particle and heavy-ion transport codes when determining the mean-free pathof a transported particle. Many transport codes determine the distance a particle is transported before it collides with the target or is stopped
in the target material, with the Monte Carlo (MC) method using semiempirical parametrization models for the total reaction cross sections.
In order to improve the well-known Kox and Shen models of total reaction cross sections and allow the models to be used at energies below
30 MeV/nucleon, we have proposed a modified parametrization of the transparency parameter. We have also reported that the Kox andShen models have a projectile-target asymmetry and should be used so that the lighter nucleus is always treated as the projectile.
(7) Energy and mass number dependence of total reaction cross sections of nuclei
We have systematically analyzed nuclear reaction data that are sensitive to nuclear size, namely, proton-nucleus total reaction crosssections and differential elastic cross sections, using a phenomenological black-sphere approximation of nuclei that we are developing. In
this framework, the radius of the black sphere is found to be a useful length scale that simultaneously accounts for the observed
proton-nucleus total reaction cross section and first diffraction peak in the proton elastic differential cross section. This framework is
expected to be applicable to any kind of projectile that is strongly attenuated in the nucleus. On the basis of a cross-section formula
constructed within this framework, we find that a less familiar A1/6 dependence plays a crucial role in describing the energy dependence of
proton-nucleus total reaction cross sections.
(8) Probing the critical behavior in the evolution of GDR width at very low temperatures in A ~ 100 mass region
The influence of giant dipole resonance (GDR) induced quadrupole moment on GDR width at low temperatures is investigatedexperimentally by measuring the GDR width systematically in the unexplored temperature range T = 0.8-1.5 MeV, for the first time, in A ~100 mass region. The measured GDR width, using alpha induced fusion reaction, for 97Tc confirms that the GDR width remains constant at
the ground state value up to a critical temperature and increases sharply thereafter with the increase in T. The data have been compared withthe adiabatic thermal shape fluctuation model (TSFM), phenomenological critical temperature fluctuation model (CTFM) and microscopic
phonon damping model (PDM). Interestingly, the CTFM and PDM give the similar results and agree with the data, whereas the TSFM
differs significantly even after incorporating the shell effects indicating towards the inclusion of GDR-GQR coupling in the TSFM.
(9) Giant dipole resonance in highly excited nuclei
The evolution of the giant dipole resonance’s (GDR) width and shape at finite temperature T and angular momentum J is describedwithin the framework of the phonon damping model (PDM). The PDM description is compared with the established experimental
systematics obtained from heavy-ion fusion and inelastic scattering of light particles on heavy target nuclei, as well as with predictions byother theoretical approaches. Extended to include the effect of angular momentum J, its strength functions have been averaged over the
probability distributions of T and J for the heavy-ion fusion evaporation reaction, which forms the compound nucleus 88Mo at high T and J.
The results of theoretical predictions are found in excellent agreement with the experimental data. The predictions by PDM and theheavy-ion fusion data are also employed to predict the viscosity of hot medium and heavy nuclei.
We also explore an approach that includes temperature-dependent shell effects and fluctuations of the pairing field in the thermal
shape fluctuation model (TSFM). We apply this approach to study the width of GDR in 120Sn, 179Au and 208Pb. Our results demonstrate that
the TSFM that includes pairing fluctuations can explain the recently observed quenching in the GDR width.
(10) Reentrance phenomenon of superfluid pairing in hot rotating nuclei
When a nucleus rotates (total angular momentum J and/or rotational frequency ω are not zero), the nucleon (proton and neutron) pairs
located around the Fermi surface will scatter to the empty levels nearby and lead to the decreasing of pairing correlation. When the J or ω issufficiently high, i.e., equal to the critical value J_c or ωc, the scattered nucleons completely block the single-particle levels around the
Fermi surface. Consequently, pairing correlation disappears. However, when J is slightly higher than Jc (or ω >ωc), the increase of
temperature T will relax the particles scattered around the Fermi surface and causes some levels become partially unoccupied, making themavailable for scattered pairs. As a result, the pairing correlation reappears at some critical value T1. As T goes higher, e.g., at T2 > T1, thenewly created pairs will be eventually broken down again. This phenomenon is called the pairing reentrance. The recently developed- 354 -

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FTBCS1 theory that includes the effect due to quasiparticle-number fluctuations in the pairing field and angular momentum z projection at
T ≠ 0 has predicted the pairing reentrance effect in some realistic nuclei. The shell-model Monte Carlo calculations have suggested that thepairing reentrance effect can be observed in the nuclear level density in a form of a local maximum at low T (or excitation energy E*) andhigh J (or ω). Recently, an enhancement of level density of 104Pd at low E* and high J has been experimentally reported. This work
demonstrates that the enhancement observed in the extracted level density of 104Pd is the first evidence of pairing reentrance phenomenon
in atomic nuclei.

Members
Associate Chief Scientist (Lab. Head)
Takashi NAKATSUKASA
Research & Technical Scientist
Akihisa KOHAMA (Senior Research Scientist)
Nishina Center Research Scientist
Dang Dinh NGUYEN
Special Postdoctoral Researchers
Kohei WASHIYAMA (– Mar. 31, 2015)

Koichi SATO

Foreign Postdoctoral Researcher
Haozhao LIANG (– Mar. 31, 2015)
Research Consultants
Akitsu IKEDA

Kenichi MATSUYANAGI

Visiting Scientists
Kazuhiro OYAMATSU (Aichi Shukutoku Univ.)
Kei IIDA (Kochi Univ.)
Yasuyuki SUZUKI (Niigata Univ.)
Nguyen Quang HUNG (Tan Tao Univ.)
Kazuyuki OGATA (Osaka Univ.)

Takashi ABE (Univ. of Tokyo)
Naoyuki ITAGAKI (Kyoto Univ.)
Kazuko TANABE (Otsuma Women's Univ.)
Kaori KAKI (Shizuoka Univ.)
Kiyomi IKEDA (Niigata Univ.)

Student Trainees
Rhine Kumar Arayakkandi Keechiprath(Indian Inst. of Tech. Roorkee)
Part-time Workers
Kiyomi ARAI
Noriko OKAYASU
Tsuneyo SUZUKI
Miki KANOU

Yoko OZAWA (– Mar. 31, 2014)
Kahori SHIMADA (– Sep. 30, 2014)
Mie DOI (Oct. 1, 2014 –)Naomi MURAKAMI (Jan. 1, 2015–)- 355 -

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Ⅵ. RNC ACTIVITIESTheoretical Research Division
Strangeness Nuclear Physics Laboratory
1. Abstract

We proposed accurate calculation method called ‘Gaussian Expansion Method using infinitesimally shifted Gaussian lobe basis
function’. When one proceeds to four-body systems, calculation of the Hamiltonian matrix elements becomes much laborious. In order tomake the four-body calculation tractable even for complicated interactions, the infinitesimally-shifted Gaussian lobe basis function has
been proposed. The GEM with the technique of infinitesimally-shifted Gaussians has been applied to various three-, four- and five-body
calculations in hypernuclei, the four-nucleon systems, and cold-atom systems. As results, we succeeded in extracting new understandings invarious fields.

2. Major Research Subjects(1) Hypernuclear structure from the view point of few-body problem(2) Structure of exotic hadron system(3) Baryon-baryon interaction based on lattice QCD(4) Structure of three- and four-body 4He atom systems

3. Summary of Research Activity(1) Recently, we observed of neutron-rich system nnΛ as a bound state. To investigate this system, we performed nnΛ+NnΣ three-bodycoupled channel calculation. Using YN interaction to reproduce observed binding energies for 4ΛH, 4ΛHe, and 3ΛH, we do not find any
bound state for nnΛ system which is inconsistent with the data. Now, we propose the experimentalists to perform a search experimentof nnΛ system again.
(2) It is interesting to study the structure of Ar isotope, since we have some superdeformed states (SD) in this Isotope. Within theframework of AMD method, we investigate the structure of SD states. In addition, we study the structure of Ar Λ hypernuclei. Then, we
found that Λ-separation energy was dependent on the degree of deformation of core nuclei.
(3) Using several realistic 4He atomic potential, we calculate Efimov spectra of trimer and tetramer systems of 4He. Our result shows anextension of the universality in Efimov trimers that the appearance of the repulsive barrier at the three-body hyperradius R3 ≈ 2 W rvd
makes the critical scattering lengths independent of the short-range details of the interactions as reported in the literature and also in thepresent work for the 4He trimer with the realistic potentials.

Members
Associate Chief Scientist (Lab. Head)
Emiko HIYAMA
Contract Researcher
Yasuro FUNAKI
Research Scientists
Hiroya SUNO (Research Scientist, concurrent : Strangeness Nuclear Physics Laboratory,

Main: Field Theory Research Team)Special Postdoctoral Researcher
Masahiro ISAKA
Foreign Postdoctoral Researcher
Philipp GUBLER (– Oct. 31, 2014)
Postdoctoral Researcher
Hajime TOGASHI (Apr. 1, 2014 –)Research Consultants
Yasuo YAMAMOTO (– Mar. 31, 2014)
Yoshikazu FUJIWARA (Apr. 1, 2014 –)Toshio MOTOBA (– Mar. 31, 2014)

Junior Research Associates
Tetsuya YOSHIDA (Apr. 1, 2014 –)Shota OHNISHI

Saori MAEDA (Apr. 1, 2014 –)- 356 -

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Visiting Researchers
Naoyuki Sakumichi (JSPS)

Christiane SCHMICKLER (JSPS, Apr. 1, 2014 – Mar. 31, 2015)

Visiting Scientists
Takayuki MYO (Osaka Inst. of Tech.)
Hidekatsu NEMURA (Univ. of Tsukuba)
Masakiyo KITAZAWA (Osaka Univ.)
Taiichi YAMADA (Kanto Gakuin Univ.)
Takenori FURUMOTO (Ichinoseki Nat’l College of Tech.)Yasuo YAMAMOTO (Tsuru Univ.) (Apr. 1, 2014 –)Makoto OKA (Tokyo Tech.)Atsushi UMEYA (Nihon Inst. of Tech.)
Tetsuo HYODO (Kyoto Univ.)
Daisuke JIDO (Tokyo Met. Univ.)
Soichi ISHIKAWA (Hosei Univ.)
Thomas Adriaan RIJKEN (Radboud Univ. Nijmegen)Atsushi HOSAKA (Osaka Univ.)
Shoji SHINMURA (Gifu Univ.)
Akinobu DOTE (KEK)

Kazuma NAKAZAWA (Gifu Univ.)
Toru SATO (Osaka Univ.)
Jinniu HU (Peking Univ.)
Philipp GUBLER (ECT*)
Wolfram WEISE (TUM)
Yoshikazu FUJIWARA (Kyoto Univ.) (– Mar. 31, 2014)
Toshio MOTOBA (Osaka Elec.-Com. Univ.) (Apr. 1, 2014 –)Shuichi GOJUKI (SGI Japan Ltd.)
Javier ROCAMAZA (Univ. of Milan)
Hyun-Chul KIM (Inha Univ.)
Xian-Rong ZHOU (Xiamen Univ.)
Satoshi NAKAMURA (Tohoku Univ.)
Satoru HIRENZAKI (Nara Women's Univ.)
Tomokazu FUKUDA (Osaka Elec.-Com. Univ.)
Kiyomi IKEDA (Niigata Univ.) (Jul. 1, 2014 –)Student Trainees
Akira YOKOTA (Tokyo Tech.)
Saori MAEDA (Tokyo Tech.) (– Mar. 31, 2014)
Tetsuya YOSHIDA (Tokyo Tech.) (– Mar. 31, 2014)

Yongwoo CHOI (Kyungpook Nat’l Univ.) (– Feb. 31, 2015)
Hana GIL (Kyungpook Nat’l Univ.) (– Feb. 31, 2014)- 357 -

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Ⅵ. RNC ACTIVITIESTheoretical Research Division
Mathematical Physics Laboratory
1. Abstract

The aim of mathematical physics laboratory is to apply mathematical scheme to resolve long-standing issues in various subjects ofphysics. Mathematics, in particular that originates in superstring theory, has universal feature which is common to wide range of physics.
This covers elementary particle physics, hadron physics, nuclear physics, cosmology, general relativity and condensed matter physics. We
apply mathematical scheme such as superstring theory, D-branes, AdS/CFT correspondence, solitons, statistical mechanics and integrable
systems. Topics which the laboratory covers currently include non-perturbative analysis of quantum chromo-dynamics, superstrings, andmodels beyond the standard model of particle physics, and soliton physics.

2. Major Research Subjects(1) Application of Superstring Theory(2) Non-perturbative analyses of strongly-coupled gauge theories(3) Physics of Black Holes and Cosmology(4) Solitons physics(5) Mathematical physics(6) Lattice gauge theory

3. Summary of Research Activity

Interplay between mathematics and physics is indispensable, as any physics law is described in terms of mathematics. However, thepresent status of various theoretical physics does not fully appreciate the usefulness of mathematics, as each topics goes into details and hasless interaction with other subjects even nearby. We integrate various subjects of physics, by applying recent development of mathematics
and mathematical physics, to solve long-standing issues in physics. In particular, mathematical methods in superstring theory has beendeveloped and is mature enough to be applied to other physics. We put efforts on the application as described below, in addition to someother mathematical techniques such as numerical simulations, solitons and integrable systems.

(1) Application of superstring theory
1) Magnetic instability in AdS/CFT : Schwinger effect and Euler-Heisenberg Lagrangian of Super- symmetric QCD
To reveal the Schwinger effect for quarks, i.e., pair creation process of quarks and antiquarks, we derive the vacuum decay rate atstrong coupling using AdS/CFT correspondence. Magnetic fields, in addition to the electric field responsible for the pair creation,
causes prominent effects on the rate, and is important also in experiments such as RHIC/LHC heavy ion collisions. In this paper,
through the gravity dual we obtain the full Euler-Heisenberg Lagrangian of N=2 supersymmetric QCD and study the Schwinger
mechanism with not only a constant electric field but also a constant magnetic field as external fields. We determine the quark massand temperature dependence of the Lagrangian. In sharp contrast with the zero magnetic field case, we find that the imaginary part,and thus the vacuum decay rate, diverges in the massless zero-temperature limit. This may be related to a strong instability of the QCD
vacuum in strong magnetic fields. The real part of the Lagrangian serves as a generating function for non-linear electro-magnetic
responses, and is found such that the Cotton-Mouton effect vanishes. Interestingly, our results of the Schwinger / Cotton-Mouton
effects coincide precisely with those of N=2 supersymmetric QED.
2) Electric Field Quench in AdS/CFTAn electric field quench, a suddenly applied electric field, can induce nontrivial dynamics in confining systems which may lead tothermalization as well as a deconfinement transition. In order to analyze this nonequilibrium transitions,we use the AdS/CFT
correspondence for N=2 supersymmetric QCD that has a confining meson sector. We find that the electric field quench causes thedeconfinement transition even when the magnitude of the applied electric field is smaller than the critical value for the static case(which is the QCD Schwinger limit for quark-antiquark pair creation). The time dependence is crucial for this phenomenon, and thegravity dual explains it as an oscillation of a D-brane in the bulk AdS spacetime. Interestingly, the deconfinement time takes only
discrete values as a function of the magnitude of the electric field. We advocate that the new deconfinement phenomenon is analogous
to the exciton Mott transition.
3) Entropic destruction of heavy quarkonium in non-Abelian plasma from holography
Lattice QCD indicates a large amount of entropy associated with the heavy quark-antiquark pair immersed in the quark-gluon
plasma. This entropy grows as a function of the inter-quark distance giving rise to an entropic force that can be very effective indissociating the bound quarkonium states. In addition, the lattice data show a very sharp peak in the heavy quark-antiquark en- tropy atthe deconfinement transition. Since the quark-gluon plasma around the deconfinement transition is strongly coupled, we employ theholographic correspondence to study the entropy as- sociated with the heavy quark-antiquark pair in two theories: i) N=4
supersymmetric Yang-Mills and ii) a confining Yang-Mills theory obtained by compactification on a Kaluza-Klein circle. In bothcases we find the entropy growing with the inter-quark distance and evaluate the effect of the corresponding entropic forces. In the- 358 -

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case ii), we find a sharp peak in the entropy near the de- confinement transition, in agreement with the lattice QCD results. This peakin our holographic description arises because the heavy quark pair acts as an eyewitness of the black hole formation in the bulk ? theprocess that describes the deconfinement transition. In terms of the boundary theory, this entropy likely emerges from theentanglement of a ”long string” connecting the quark and antiquark with the rest of the system.
(2) Cosmology
1) Dynamical breaking of shift-symmetry in supergravity-based inflation
Shift-symmetry is essential to protect the flatness of the potential, even beyond the super- Planckian vacuum expectation value(VEV) for an inflaton field. The breaking of the shift- symmetry can yield potentials suitable for super-Planckian excursion of theinflaton. The aim of this paper is to illustrate that it is indeed possible to break the shift-symmetry dynamically within 4 dimensional
supergravity prior to a long phase of inflation. Thanks to the shift-symmetry, the leading contribu- tion to the inflaton potential is freefrom the dangerous exponential factor even after its breaking, which is the main obstacle to realizing the super-Planckian inflation insuper- gravity. But, in our simple model, the resulting inflaton potential is a cosine type potential rather than the power-law one and it
is difficult to realize a super-Planckian breaking scale unfortunately.
2) Effective gravitational interactions of dark matter axions
We investigate the structure of gravitational self-interactions of coherently oscillating axions in the general relativistic framework.
A generic action for a massive scalar field in the Friedmann- Robertson-Walker background is first introduced based on the effective
field theory approach to cosmological perturbations. Using the obtained setup, we evaluate the effective gravitational inter- action of
the massive scalar field, i.e. scalar quartic interactions mediated by metric perturbations. Applying the results to the system of dark
matter axions, we estimate their self-interaction rate and discuss its implications for the axion Bose-Einstein condensate dark matter
scenario. Leading contributions for the gravitational interactions of axions are given by the process mediated by the dynamical
graviton field, which is essentially the Newtonian potential induced by fluctuations of the background fluids. We find that it leads tothe same order of magnitude for the interaction rate of dark matter axions in the condensed regime, compared with the results ofprevious studies using the Newtonian approximation.
(3) Condensed matter physics
1) Current Reflection and Transmission at Conformal Defects: Applying BCFT to Transport Process
We study reflection/transmission process at conformal defects by introducing new transport co- efficients for conserved currents.
These coefficients are defined by using BCFT techniques thanks to the folding trick, which turns the conformal defect into theboundary. With this definition, exact computations are demonstrated to describe reflection/transmission process for a class ofconformal defects. We also compute the boundary entropy based on the boundary state.
2) Bulk angular momentum and Hall viscosity in chiral superconductors
We establish the Berry-phase formulas for the angular momentum (AM) and the Hall viscosity (HV) to investigate chiralsuperconductors (SCs) in two and three dimensions. The AM is defined by the temporal integral of the anti-symmetric momentum
current induced by an adiabatic defor- mation, while the HV is defined by the symmetric momentum current induced by the symmetrictorsional electric field. Without suffering from the system size or geometry, we obtain the macro- scopic AM Lz = (h/2pi) m N0/2 atzero temperature in full-gap chiral SCs, where m is the magnetic quantum number and N0 is the total number of electrons. We alsofind that the HV is equal to half the AM at zero temperature not only in full-gap chiral SCs as is well-known but also in nodal ones,
but its behavior at finite temperature is different in the two cases.
(4) Mathematical physics
1) Duality and integrability of supermatrix model with external source
We study the Hermitian supermatrix model involving an external source. We derive the deter- minantal formula for thesupermatrix partition function, and also for the expectation value of the characteristic polynomial ratio, which yields the duality
between the characteristic polyno- mial and the external source with an arbitrary matrix potential function. We also show that thesupermatrix integral satisfies the one and two dimensional Toda lattice equations as well as the ordinary matrix model.
2) Laplace operators on Sasaki-Einstein manifold
We decompose the de Rham Laplacian on Sasaki-Einstein manifolds as a sum over mostly positive definite terms. An immediate
consequence are lower bounds on its spectrum. These bounds constitute a supergravity equivalent of the unitarity bounds in dual
superconformal field theories. The proof uses a generalization of Kahler identities to the Sasaki-Einstein case.
3) Non-Lagrangian Theories from Brane Junctions
We use 5-brane junctions to study the 5D TN SCFTs corresponding to the 5D N=1 uplift of the 4D N=2 strongly coupled gauge
theories, which are obtained by compactifying N M5 branes on a sphere with three full punctures. Even though these theories have no
Lagrangian description, by using the 5-brane junctions proposed by Benini, Benvenuti and Tachikawa, we are able to derive their
Seiberg-Witten curves and Nekrasov partition functions. We cross-check our results with the 5D superconformal index proposed by
Kim, Kim and Lee. Through the AGTW correspondence, we discuss the relations between 5D superconformal indices and n-point
functions of the q-deformed WN Toda theories.
4) From the Berkovits formulation to the Witten formulation in open superstring field theory
The Berkovits formulation of open superstring field theory is based on the large Hilbert space of the superconformal ghost sector.
We discuss its relation to the Witten formulation based on the small Hilbert space. We introduce a one-parameter family of conditions- 359 -

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5)

Ⅵ. RNC ACTIVITIES

for partial gauge fixing of the Berkovits formulation such that the cubic interaction of the theory under the partial gauge fixing reduces
to that of the Witten formulation in a singular limit. The local picture-changing operator at the open-string midpoint in the Witten
formulation is regularized in our approach, and the divergence in on-shell four-point amplitudes coming from collision of
picture-changing operators is resolved. The quartic interaction inherited from the Berkovits formulation plays a role of adjusting
different behaviors of the picture-changing operators in the s channel and in the t channel of Feynman diagrams with two cubic
vertices, and correct amplitudes in the world-sheet theory are reproduced. While gauge invariance at the second order in the coupling
constant is obscured in the Witten formulation by collision of picture-changing operators, it is well defined in our approach and isrecovered by including the quartic interaction inherited from the Berkovits formulation.
Duality of topological branes
We show a duality of branes in the topological B-model by inserting two kinds of the non-compact branes simultaneously. We
explicitly derive the integral formula for the matrix model partition function describing this situation, which correspondingly includes
both of the characteristic poly- nomial and the external source. We show that these two descriptions are dual to each other through theFourier transformation, and the brane partition function satisfies integrable equa- tions in one and two dimensions.

Members
Associate Chief Scientist (Lab. Head)
Koji HASHIMOTO
Contract Researcher
Shunji MATSUURA (Sep. 1, 2014 –)Special Postdoctoral Researchers
Masato TAKI (– Apr. 30, 2014)
Shingo TORII (– Mar. 31, 2015)
Postdoctoral Researchers
Yuki MINAMI (– Mar. 31, 2014)

Toshifumi NOUMI (– Mar. 31, 2015)

Yasuhiro YAMAGUCHI (Apr. 1, 2014 –)Visiting Researcher
Taro KIMURA (JSPS Fellow, – Mar. 31, 2015)
Senior Visiting Scientist
Koichi YAZAKI (Univ. of Tokyo)
Visiting Scientists
Yoshio YAMAGUCHI (Univ. of Tokyo)
Shoichi MIDORIKAWA (Aomori Univ.)
Keiji IGI (Univ. of Tokyo)
Hiroshi ITOYAMA (Osaka City Univ.)
Yuuichirou SHIBUSA (Nagasaki Inst. of Applied Sci.)
Nobuyuki ISHIBASHI (Univ. of Tsukuba)
Asato TSUCHIYA (Shizuoka Univ.)
Tatsumi AOYAMA (Nagoya Univ.)
Kazutoshi OHTA (Meiji Gakuin Univ.)

Takeo INAMI (Chuo Univ.)
Masanori HANADA(KEK)
Yu MAEZAWA(Univ. Bielefeld)
Minoru ETO (Yamagata Univ.)
Norisuke SAKAI (Tokyo Women's Christian Univ.)
Makoto SAKAGUCHI (Ibaraki Univ.)
Tetsutaro HIGAKI (KEK)
Keisho HIDAKA (Tokyo Gakugei Univ.)
Kazuo FUJIKAWA (Univ. of Tokyo)- 360 -

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Sub Nuclear System Research Division
Radiation Laboratory
1. Abstract

Nucleons, such as protons and neutrons, are a bound state of constituent quarks glued together with gluons. The detail structure of
nucleons, however, is not well understood yet. Especially the mechanism to build up the spin of proton, which is 1/2, is a major problem inphysics of the strong force. The research goal of Radiation Laboratory is to solve this fundamental question using the world firstpolarized-proton collider, realized at RHIC in Brookhaven National Laboratory (BNL) in USA. RHIC stands for Relativistic Heavy Ion
Collider, aiming also to create Quark Gluon Plasma, the state of Universe just after the Big Bang. RIKEN-BNL Research Center (RBRC)
directed by S. Aronson carries our core team at BNL for those exciting researches using the PHENIX detector. We have found that the
proton spin carried by gluons is indeed small. We also identified W bosons in the electron/positron decay channel and in the muon decay
channel, with which we are about to conclude how much anti-quarks carry the proton spin. Other than the activities at RHIC we arepreparing new experiments at J-PARC and Fermilab to study the nature of hadron. We are also performing technical developments such asnovel ion sources, fine-pitch silicon pixel detectors and high-performance trigger electronics.

2. Major Research Subjects

1) Spin physics with relativistic polarized-proton collisions at RHIC
2) Study of nuclear matter at high temperature and/or at high density
3) Technical developments on radiation detectors and accelerators

3. Summary of Research Activity(1) Experimental study of spin structure of proton using RHIC polarized proton collider[See also RIKEN-BNL Research Center Experimental Group for the activities at BNL]
In 2014 we have reached a major milestone in determining the gluon spin contribution to the total spin of the nucleon. After initiallymeasuring small asymmetries statistically consistent with zero, we have succeeded to determine non-zero gluon polarization in the recent
high statistics runs at 510 GeV. With the valence quark spin contribution already reasonably well known, the contributions from sea quarks
and orbital angular momenta remain to be understood. PHENIX has collected data to access the sea quark polarizations via leptonic decaysof W bosons. Preliminary results have been obtained using all the data taken so far. While orbital angular momentum cannot be directly
accessed at RHIC, several transverse spin phenomena are being accumulated to study the orbital angular momentum and the overall
three-dimensional structure of the nucleon.
To further investigate these effects the PHENIX experiment proposes substantial detector upgrades to go along the expected
accelerator improvements. The proposed upgrade replaces the present magnet with a solenoid, so that we are considering to build an
open-geometry forward spectrometer which can measure hadrons, photons, electrons, muons and jets in the forward rapidity region.
Especially the Drell-Yan (quark-antiquark annihilation into lepton pairs) transverse single spin asymmetries are the main goal of these
upgrades. As a pilot measurement, some of us are participating in the Fermilab SeaQuest experiment which has been collecting muonpairs using a 120-GeV unpolarized proton at Fermilab. By measuring the unpolarized Drell-Yan process, we can study quark spin-orbit
effects which supplement what can be learned in the polarized Drell-Yan process.
(2) Experimental study of quark-gluon plasma using RHIC heavy ion collider[See also RIKEN-BNL Research Center Experimental Group for the activities at BNL]
We have completed several key measurements in the study of quark-gluon plasma at RHIC. As the top of them, we lead the analysis of
the first thermal photon measurement in heavy ion collisions. The measurement indicates that the initial temperature reached in the central
Au+Au collision at 200 GeV is about 350MeV, far above the expected transition temperature Tc~170MeV, from hadronic phase toquark-gluon plasma. This work was rewarded by Nishina Memorial Prize in 2011. Using the same “virtual photon” method used in thethermal photon measurement, we measured direct photons in d+Au collisions. The results show that there is little cold nuclear effects indirect photons. This supports that the large enhancement of direct photons observed in Au+Au is indeed due to hot quark-gluon plasma
formed in Au+Au collisions.
We also measured the elliptic flow strength, v2, of direct photons in Au+Au collisions. The results show surprisingly large v2, whichmeans the source of those photons expands elliptically. This is one of the most interesting results from RHIC in the last three years. One of
the JRA students of Radiation Laboratory led this important analysis. Also, the most recent measurements of high pT 0 suppression in
Au+Au collisions show that the suppression reduces at very high pT (pT~20GeV).
We lead measurement of heavy quark (charm and bottom) using VTX, a 4 layer silicon vertex tracker which we jointly constructedwith US DOE. The detector was installed in PHENIX in 2011. Analysis of heavy quark using the silicon vertex detector is ongoing. The
first preliminary results from the 2011 Au+Au run and 2012 p+p run was reported in the Quark Matter 2012 conference. We are now
finalizing the results for publication. Analysis of the 2014 Au+Au run is also in progress and we expect the first preliminary results from the2014 run in this year (2015).
In Wako we are operating a cluster computer system specialized to analyze huge data sets taken with the PHENIX detector. It consists- 361 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESof 28 nodes (18 old nodes and 10 new nodes) each of which has two CPUs and 10 sets of local disk for data repository (old node: quad-core
CPU, 1TB disk, new node: six-core CPU, 2TB disk). There are 264 CPU cores and 380 TB disks in total. This configuration ensures thefastest disk I/O when the jobs are assigned to the nodes where the required data sets are stored. It is also important that this scheme
doesn't require an expensive RAID system and network. Through this development we have established a fast and cost-effective solution in
analyzing massive data.
We have about 1.7 PB of data produced by the PHENIX experiment. They are stored in the archive system (HPSS) operated by the
Advanced Center for Computing and Communication (ACCC). Since ACCC decided to replace HPSS, we have started to transfer the data
into the new archive system.
(3) Study of properties of mesons and exotic hadrons with domestic accelerators
Preparation of the experiment E16 at J-PARC 50-GeV PS is underway with the Grant-in-Aid for Scientific Research on Innovative
Areas (MEXT). This experiment aims to perform a systematic study of the mass modification of low-mass vector mesons in nuclei toexplore the chiral symmetry breaking in dense nuclear matter, namely, the mechanism proposed by Nambu to generate the major part ofhadron mass.
Gas Electron Multiplier (GEM) technology is adopted for the two key detectors, GEM Tracker (GTR) and Hadron-blind Cherenkov
detector (HBD). With a cooperation with Japanese industries, GEM foils with a world-largest size (30cm x 30cm) are newly developed.
Through the beam tests at ELPH, J-PARC, LEPS, and RIKEN RIBF, the followings are achieved and proven; 1) required position
resolution of 0.1 mm, and 2) stable operation under the hadron-background environment, typically 30 times higher rate than that expectedin the J-PARC experimental area. The design parameters of the GTR and HBD were finalized and the mass-production of GTR GEM
started. HBD GEM is under the final tuning to achieve the required stability, efficiency and pion-rejection power.
For the readout electronics of GEM, a preamp using the APV25 ASIC chip is developed and tested. For the digitization and the datatransfer, the SRS system developed by CERN is also tested and adopted. Another preamp-ASIC for the trigger signal from GEM foils is
also developed and tested. Trigger logic boards, which are developed by Belle II, are tested with the firmware customized for thisexperiment.
The development phase of the detectors is just over and we are moving to the production phase. For the readout electronics, the mass
production will start in a year after some remained tests. The construction of the beam line is finally funded in KEK and started at J-PARC
in 2013. It will be completed by March 2016. The spectrometer construction at the beam line is planned to start in March 2015 and thecommissioning with a primary beam will be performed in early 2016.
(4) Detector development for PHENIX experiment
After 7 years of hard work, we installed the silicon vertex tracker (VTX) into the PHENIX detector at RHIC in December 2010. VTX
is a 4-layer silicon tracker to measure heavy quark (charm and bottom) production in p+p and heavy ion collisions at RHIC. The detector
was funded by RIKEN and the US DOE. We and RIKEN BNL Research Center are responsible for construction and operation of the inner
two pixel detectors. The VTX was successfully commissioned during the 500 GeV p+p run in 2011. Subsequently, we collected 5 billion
Au+Au events in the 2011 run, 11/pb of p+p data at 510 GeV, 3/pb of p+p data at 200 GeV, 110/b of U+U data at 193 GeV, and 2.9/nb of
Cu+Au at 200 GeV. We are now analyzing those datasets to study the interaction between heavy quarks and the quark-gluon plasma.
During the 2011 run, part of the pixel detector was damaged due to thermal stress on the detector. We repaired the damaged pixel
detectors in 2012 to 2013, and the tracker was re-installed in PHENIX before the 2014 run and has been successfully re-commissioned. The
2014 run is a major heavy quark run of RHIC and the VTX detector worked very well during the run. PHENIX recorded about 20 billion
Au+Au collision events with VTX. This dataset is effectively more than 10 times of that of 2011 data. We expect definitive results on heavy
quark measurements from the 2014 run.
Sea quark polarization measurement via W-boson production is one of the highlight of PHENIX spin program. In order to detect highmomentum muons from W-decay, we developed the momentum-sensitive trigger system for the PHENIX forward muon arms withcollaborators from KEK, Kyoto and Rikkyo University. Together with new hadron absorber, W-boson measurement was successfully
carried out using the new high momentum trigger. We accumulated high-integrated luminosity of about 250pb-1 in Run13 and almost
achieved our goal. The intensive analysis is underway towards the publication. Preliminary results were released in October 2014 and theanalysis is at the final stage towards the publication. Besides W detection, the trigger system has been also operated for heavy flavor meson
detection in conjunction with a forward vertex (FVTX) detector.
(5) Development of beam source
Under the collaboration with Brookhaven National Laboratory, we are developing various techniques for a laser ion source (LIS) to
provide high quality heavy-ion beams to the accelerators at present or in the future. In 2014, we installed a new LIS which provides various
species of singly charged ions to the RHIC-AGS complex. The commissioning was very successful and we have delivered C, Al, Ti, Si, Ta
and Au ions. We also demonstrated fast switching of ion species within one second. At this moment, we are upgrading this LIS to provide
gold beam and other lighter ion beams simultaneously. Once this upgrade is completed, all the ion beams except proton and uranium will be
supplied by the LIS at the RHIC-AGS complex with much enhanced versatility. Besides, we are studying the highly charged ionization andmagnetic field confinement of laser ablation plasma, and testing a linear accelerator model which selectively accelerates charge states.

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Members
Chief Scientist (Lab. Head)
Hideto EN’YO (Director, RNC)
Vice Chief Scientist
Yasuyuki AKIBA
Research & Technical Scientists
Yasushi WATANABE (Senior Research Scientist)
Yuji GOTO (Senior Research Scientist)
Itaru NAKAGAWA (Senior Research Scientist)
Satoshi YOKKAICHI (Senior Research Scientist)

Ralf SEIDL (Senior Research Scientist)
Hiroaki ONISHI (Senior Research Scientist, concurrent; Advanced Meson
Science Lab.)

Contract Researchers
Takashi HACHIYA (– Mar. 31, 2015)
Maki Kurosawa (– Sep. 30, 2014)

Hisayuki TORII (– Mar. 31, 2014)

Postdoctoral Researchers
Yoki ARAMAKI (– Mar. 31, 2014)
Yuhei MORINO (– Jul. 31, 2014)
Tomonori TAKAHASHI (– Mar. 31, 2014)

Takayuki SUMITA
Yoshimasa IKEDA (– Mar. 31, 2014)

Junior Research Associates
Yusuke KOMATSU (Univ. of Tokyo, – Mar. 31, 2014)
Shinichi HAYASHI (Univ. of Tokyo, –Mar. 31, 2015)
Yuko SEKIGUCHI (Univ. of Tokyo)
Koki KANNO (Univ. of Tokyo)
Wataru NAKAI (Univ. of Tokyo)
Megumi SEKINE (Tokyo Tech., – Mar. 31, 2014）
Sanshiro MIZUNO (Univ. of Tsukuba, – Mar. 31, 2015)
Tomoya TSUJI (Univ. of Tokyo, – Mar. 31, 2015)

Tomoya HOSHINO (Hiroshima Univ.)
Shunsuke Ikeda (Tokyo Tech.)
Masafumi KUMAKI (Waseda Univ.)
Hiroshi NAKAGOMI (Univ. of Tsukuba)
Yasuhiro FUWA (Kyoto Univ., – Mar. 31, 2015)
Satoshi YANO (Hiroshima Univ.)
Daisuke WATANABE (Univ. of Tsukuba)
Kohei TERASAKI (Univ. of Tokyo)

International Program Associates
Sanghwa PARK (Seoul Nat’l Univ., – Feb. 26, 2015)
Inseok YOON (Seoul Nat’l Univ.)
Minjung KIM (Seoul Nat’l Univ.)

Taebong MOON (Yonsei Univ.)
Chong KIM (Korea Univ., – Dec. 9, 2014)
Se Young HAN (Ewha Womans Univ., Oct. 1, 2014 –)Visiting Researcher
Daisuke KAWAMA (JSPS Fellow, – Mar. 31, 2015)
Senior Visiting Scientists
Toshiaki SHIBATA (Tokyo Tech.)Takashi NAKANO (Osaka Univ.)

Visiting Scientists
Kyoichiro OZAWA (KEK)
Noriyoshi ISHII (Univ. of Tsukuba)
Susumu SATO (JAEA)
Megumi NARUKI (KEK)
Akitomo ENOKIZONO (Rikkyo Univ.)
Yoshinori FUKAO (KEK)
Michiko SEKIMOTO (KEK)
Kiyoshi TANIDA (Seoul Nat’l Univ.)
Hirotsugu KASHIWAGI (JAEA)
Taku GUNJI (Univ. of Tokyo)
Junpei TAKANO (KEK)
Kazuya AOKI (KEK)
Masashi KANETA (Tohoku Univ.)
Munehisa OHTANI (Kyorin Univ.)
Yorito YAMAGUCHI (Univ. of Tokyo)
Youngil KWON (Yonsei Univ.)
Kenichi NAKANO (Tokyo Tech.)Maya SHIMOMURA (Iowa State Univ.)
Noriyosu HAYASHIZAKI (Tokyo Tech.)Yuhei MORINO (KEK)
Kenji FUKUSHIMA (Keio Univ.)
Atsushi NAKAMURA (Hiroshima Univ.)
Ryo ICHIMIYA (KEK)
Tomohiro NISHITANI (Nagoya Univ.)
Tomonori TAKAHASHI (Osaka Univ.)
Tsutomu MIBE (KEK)
Makoto KUWAHARA (Nagoya Univ.)
Masahiro OKAMURA (BNL)
Shunzo KUMANO (KEK)
Bentz WOLFGANG (Tokai Univ.)
Alexander BAZILEVSKY (BNL)
Shin-ya SAWADA (KEK)
Ryotaro MUTO (KEK)
Masanori HIRAI (Tokyo Univ. of Sci.)- 363 -

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Student Trainees
Yusuke KOMATSU (Univ. of Tokyo)
Shoichiro NISHIMURA (Univ. of Tokyo)
Takuya SHIBUKAWA (Univ. of Tokyo)
Yuki OBARA (Univ. of Tokyo)
Yusuke OYA (Hiroshima Univ.)
Interns
Hidemitsu ASANO (Kyoto Univ.)
Chong KIM (Korea Univ.)
Sarah CAUSSIN
Part-time Workers
Maki KUROSAWA (Oct. 1, 2014 –)Kimiaki HASHIMOTO (Rikkyo Univ., – Mar. 31, 2014)
Ryoji AKIMOTO (Univ. of Tokyo, – Mar. 31, 2014)
Takeru IGURI (Rikkyo Univ., – Mar. 31, 2014)
Assistants
Keiko SUZUKI

Ⅵ. RNC ACTIVITIESKazuya NAGASHIMA (Hiroshima Univ.)
Hikari MURAKAMI (Univ. of Tokyo)
Yosuke UEDA (Hiroshima Univ.)
Key NAGAI (Tokyo Tech.)

Kotoko SHUKUTANI (Rikkyo Univ.)
Yomei FUKUSHIMA (Rikkyo Univ.)
Junsang PARK (Seoul Nat‘l Univ.)
Wataru SAITO (Rikkyo Univ., – Mar. 31, 2014)
Toru NAGASHIMA
Hikari MURAKAMI (Univ. of Tokyo)

Mitsue YAMAMOTO- 364 -

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Sub Nuclear System Research Division
Advanced Meson Science Laboratory
1. Abstract

Particles like muons, pions, and kaons have finite life times, so they do not exist in natural nuclei or matters. By implanting theseparticles into nuclei/matters, exotic phenomena in various objects can be studied from new point of view.
Kaon is the second lightest meson having “strange”-quark as a constituent quark, which also does not exist in natural nuclei. It is
expected that if one embed mesons into nuclei, the sizes of the nuclei become smaller and one can form a high density object beyond thenormal nuclear density. Study of this object could lead to better understanding of the origin of the mass of the matter, and may reveal thequark degree of freedom beyond the quark-confinement. The other example is the weak interaction in nuclear matter. It can only be studied
by the weak decay of hypernuclei, which have Lambda particle in the nuclei.
Muon provides even wider scope of studies, covering condensed matter physics as well as nuclear and atomic physics, and we aretrying to extend the application field further into chemical and biological studies. For instance, stopping positively charged muon in amaterial, we obtain information on the magnetic properties or the local field at the muon trapped site (µSR). Injecting negatively charged
muon to hydrogen gas, muonic hydrogen atom (µp) is formed. We are planning to measure µp hyperfine splitting energy to measure proton
magnetic radius, which is complementary quantity to the proton charge radius and its puzzle lately attracts strong interest. We are alsointerested in precision measurement of muon property itself, such as muon anomalous magnetic moment (g-2) to study physics beyond thestandard model.
In our research, we introduce different kind of impurities into nuclei / matters, and study new states of matter, new phenomena, or theobject properties.

2. Major Research Subjects(1) Study of meson property and interaction in nuclei(2) Origin of matter mass / quark degree of freedom in nuclei(3) Condensed matter and material studies with muon(4) Nuclear and particle physics studies via muonic hydrogen(5) Development of ultra cold muon beam, and its application from material science to particle physics

3. Summary of Research Activity(1) Hadron physics at J-PARC, RIKEN-RIBF, GSI and SPring-8
Kaon and pion will shed a new insight to the nuclear physics. The discovery of deeply bound pionic atom enables us to investigate theproperties of mesons in nuclear matter. At RIKEN-RIBF, we are preparing precise experimental study of the pionic atom. We have also
started next generation kaon experiments (E15 and E31) at J-PARC. In these experiments, we are aiming at precise determination of the
KbarN interaction, and clarify the nature of kaon in nuclei and the nature of Λ(1405), which could be K-p bound state. At Spring-8 and at
GSI, we are also aiming to study omega and η’ nuclei. By these experiments, we aim to be a world-leading scientific research group using
these light meta-stable particles.
(1-A) Deeply bound kaonic nuclei
We have performed experimental exploration of theoretically predicted deeply bound kaonic nuclear states, such as the <K-pp> boundstate. One of the most interesting features of the kaonic nucleus is the strong attraction of the KbarN interaction. Because of this strong
attraction, the kaon in nucleus will attract surrounding nucleons, resulting in extremely high-density object, which is several times larger
than normal nuclear density. Measurement of the kaon properties at such high energy density will provide precious information on theorigin of hadron masses and the chiral symmetry breaking and its partial restoration.
The experiment J-PARC E15 aims to identify the nature of the <K-pp> bound state by the in-flight 3He(K-, n) reaction, which allows
us to investigate such state both in the formation via the missing-mass spectroscopy using the emitted neutron, and in its decay via theinvariant-mass spectroscopy by detecting decay particles from <K-pp>. For the experiment, we constructed a dedicated spectrometersystem at the secondary beam-line, K1.8BR, in the hadron hall of J-PARC.
The first physics data-taking was carried out in March and May, 2013 with 6x109 kaons on 3He target, corresponding to a ~1% of theapproved proposal. We successfully obtained semi-inclusive 3He(K-, n) X missing-mass spectrum, and found a tail structure just below themass threshold of (K- + p + p) which cannot be explained by well-known processes and backgrounds. We also demonstrated an exclusive
analysis by reconstructing 3He(K-, Λp) n events. To derive more information on the KbarN interaction by the exclusive measurement, we areplanning to perform the second physics-run, in which 10 times more data will be accumulated.
(1-B) Precision X-ray measurement of kaonic atom
Simultaneously, with the above experiment (1), we have performed an X-ray spectroscopy of atomic 3d→2p transition of negatively
charged K mesons captured by helium atoms (J-PARC E17). However, the energy resolution of the conventional semiconductor
spectrometers is insufficient to see the K- - nucleus potential observed by atomic levels at zero energy. This is closely related to the problem
on the existence of deeply bound kaonic states in nuclei, well below the atomic levels, and this is one of the biggest problems in strangeness- 365 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

nuclear physics. Aiming to provide a breakthrough from atomic level observation, we will perform high-resolution X-ray spectroscopy ofkaonic atoms at a J-PARC hadron beam line using a novel cryogenic X-ray spectrometer: an array of superconducting
transition-edge-sensor (TES) micro-calorimeters. The spectrometer offers unprecedented energy resolution, which is about two orders ofmagnitude better than that of conventional semiconductor detectors. A spectrometer array of 240 pixels will have an effective area of
about 20 mm2. Very recently, we have performed a proof-of-principle experiment by measuring pionic-atom X rays with a TES array at the
PiM1 beam line at the Paul Scherrer Institut (PSI), and successfully demonstrated the feasibility of TES-based exotic-atom x-ray
spectroscopy in a hadron-beam environment. Based on the results, we are preparing for the kaonic-atom experiment at J-PARC.
Another important X-ray measurement of kaonic atom would be 2p→1s transition of kaonic deuteron. We have measured sametransition of kaonic hydrogen, but the width and shift from electro-magnetic (EM) value reflect only isospin average of the KbarN
interaction. We can resolve isospin dependence of the strong interaction by the measurement. We submitted a proposal to J-PARC PAC
to measure kaonic deuteron X-ray and got stage-one approval.
(1-C) Deeply bound pionic atoms and η’ mesic nuclei
We have been working on precision spectroscopy of pionic atoms systematically, that leads to understanding of the origin of hadronmass. The precision data set stringent constraints on the chiral condensate at nuclear medium. We are presently preparing for the precision
measurement at RIBF. The first measurement is aiming at 121Sn as the first step for the systematic spectroscopy. A pilot experiment was
performed in 2010, and showed a very good performance of the system. We have been analyzing the data to improve experimental setup of
the pionic atom spectroscopy at the RIBF in RIKEN. We expect to achieve better experimental resolution with much reduced systematic
errors.
We are also working on spectroscopy of η’ mesic nuclei in GSI/FAIR. Theoretically, peculiarly large mass of η’ is attributed to UA(1)symmetry and chiral symmetry breaking. As a result, large binding energy is expected for η’ meson bound states in nuclei (η’-mesic
nuclei). From this measurement, we can access information about partial restoration of chiral symmetry in nuclear media via the binding
energy and decay width of η’-nuclear bound state.
(1-D) Hadron physics at SPring-8/LEPS2
Photo-production of meson in nuclei is known to be a powerful tool to investigate property of the hadron in nuclear media. For thisstudy, we started a new experimental project named LEPS2 (Laser Electron Photon at SPring-8 II) in this RIKEN Mid-term. The
experimental hutch for LEPS2 at SPring-8 was constructed in March 2011, lead by RIKEN. The Large solenoid spectrometer magnet (2.96m inner diameter x 2.22 m length) was successfully transported from BNL (US) to SPring-8 and installed into LEPS2 hutch in 2011.
One of the first physics programs is photo-production of η’ in nuclei. Especially (γ, p) is most important reaction channel, where wecan perform missing mass spectroscopy by detecting forward going proton. One of the big advantage of photo-production reaction is thatthe initial reaction is expected to be much cleaner than the hadron channel.
Detector construction for the first physics program is in progress. The 4π Electro-Magnetic calorimeter has been constructed andproton counter to detect forward going proton produced via (γ, p) reaction was installed in November 2013. Engineering run for the firstexperiment was performed in December 2013 to confirm performance of our detector system. Full set of the detector will be installed by
mid April 2014 and we are planning to perform first physics data taking run starting from mid April 2014 to end of July 2014.
(2) Muon science at RIKEN-RAL branch
The research area ranges over particle physics, condensed matter studies, chemistry and life science. Our core activities are based on
the RIKEN-RAL Muon Facility located at the Rutherford-Appleton Laboratory (UK), which provides intense pulsed-muon beams. We havevariety of important research activities such as particle / nuclear physics studies with muon's spin and condensed matter physics by muon
spin rotation / relaxation / resonance (μSR).
(2-A) Condensed matter/materials studies with μSR
We have opened the new µSR spectrometer named CHRONUS to collaborative experiments from the May-June cycle in 2014. To
have higher affinity on µSR studies with the ISIS muon facility, common data acquisition (DAQ) system with the ISIS standard DAQ(DAEIII) and the front-end control system (SECI) have been installed and optimized along with other equipment in Port-4. The same DAQ
and control systems will be installed in Port-2 as well. Thus, we can perform two independent µSR experiments in Port-2 and 4 at the sametime, switching double-pulse to share beam between the two.
Among our scientific activities on µSR studies from year 2012 to 2014, following five subjects of material sciences are most importantachievements at the RIKEN-RAL muon facility:
1) A static ordering of small Ir moments in the pyrochlore iridate, Nd 2 Ir 2 O 7 , was examined. We found that this system is locatedclose to the quantum critical point.
2) A static ordering of Yb moment in pyrochlore structure of Yb 2 Ti 2 O 7 crystal has been confirmed. This ordering can be explainedby the Higgs mechanism.
3) Spontaneous small static internal fields in the superconducting state of URu 2 Si 2 have been measured. From the data and its
crystal structure, we obtained a scenario to explain superconducting mechanism of this system.
4) The universality class of the Mott transition in EtMe 3 P[Pd(dmit) 2 ] 2 has been confirmed by pressure dependences oftransportation properties.
5) A novel coexisting state between Fe spin-glass and Cu stripe ordered states have been found in the doverdoped regime of
La 2-x Sr x Cu 1-y Fe y O 4 .

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)(2-B) Nuclear and particle physics studies via ultra cold muon beam and muonic atoms
If we can improve muon beam-emittance, beam-timing and energy-dispersion (so-called “ultra-slow muon”), then the capability ofµSR study will be drastically improved. The ultra-slow muon beam can be stopped in thin foil, multi-layered materials and artificial lattices
and we can apply the μSR techniques to surface and interface science. The development of ultra-slow muon beam is also very important as
the source of ultra-cold (pencil-like small emittance) muon beam for muon g-2 measurement. Therefore, we have been working on R&D
study.
We had been working on the “ultra-slow muon” generation based on the following technique, namely, positive muon beam withthermal energy has been produced by laser ionization of muoniums in vacuum (bound system of μ+ and electron) emitted from the hottungsten surface by stopping “surface muon beam” at Port-3. However, the muon yield and obtained emittance was far from satisfactory,
and remained to be far from any kind of realistic application.
Therefore, in this mid-term, we are developing two key components first, namely high efficiency muonium generator at room
temperature and high intensity ionization laser. The study of muonium generator has been done in collaboration with TRIUMF. In 2013, wedemonstrated tremendous increase of the muonium emission efficiency by fabricating fine laser drill-holes on the surface of silica aerogel.
We also developed a high power Lyman-α laser in collaboration with laser group at RIKEN. In this laser development, we succeeded tosynthesize novel laser crystal Nd:YGAG, which has an ideal wave-length property for laser amplification to generate Lyman-α by fourwave mixing in Kr gas cell. The developed new laser will ionize muoniums 100 times more efficiently for slow muon beam generation. In
order to fully apply these new developments to slow muon generation, we designed and manufactured a new beam line based on
microscope optics. Its installation and beam test is planned in the first half of 2015.
Concerning the muonic atom, we are planning a new precise measurement of proton radius. A large discrepancy was found recently inthe proton charge radius between the new precise value from muonic hydrogen atom and those from normal hydrogen spectroscopy and e-p
scattering. We propose a precise measurement of Zemach radius (with charge and magnetic distributions combined) using the laser
spectroscopy of hyperfine splitting energy in the muonic hydrogen atom. Preparation of the hydrogen target, mid-infrared laser and muon
spin polarization detectors is in progress.

Members
Chief Scientist (Lab. Head)
Masahiko IWASAKI
Vice Chief Scientist
Katsuhiko ISHIDA
Research & Technical Scientists
Isao WATANABE (Senior Research Scientist)
Kenta ITAHASHI (Senior Research Scientist)
Haruhiko OUTA (Senior Research Scientist)

Hiroaki OHNISHI (Senior Research Scientist)
Fuminori SAKUMA (Senior Research Scientist)
Yue MA (Research Scientist)

Contract Researchers
Yu OISHI
Shinji OKADA
Masaharu SATO

Majed ABEDL JAWAD (– Sep. 30, 2014)
Teiichiro MATSUZAKI (Main; Team Leader, Muon Data Team, Dec. 1,
2014 - )Special Postdoctoral Researchers
Tadashi HASHIMOTO (Apr. 1, 2014 - )Ikuto KAWASAKI (– Sep. 30, 2014)

Special Temporary Employees
Teiichiro MATSUZAKI (– Nov. 30, 2014)
Research Consultants
Yoshinori AKAISHI
Hironari MIYAZAWA

Masayasu KAMIMURA

Junior Research Associates
Kazuo TANAKA (Univ. of Tokyo) (Apr. 1, 2014- )Yuki NOZAWA (Kyoto Univ) ( – Mar. 31, 2015)
Sohtaro KANDA (Univ. of Tokyo) (– Mar. 31, 2014)

Takuya SHIBUKAWA (Univ. of Tokyo) (Apr. 1, 2014- )Hirotomo HAMANO (Osaka Univ.)
Nam TRAN (Osaka Univ.) (Apr. 1, 2014- )International Program Associates
Edi SUPRAYOGA (Bandung Inst. Tech.)Zhang QI (Lanzhou Univ.)

Noraina ADAM (USM, Feb. 15, 2014 –)Sungwon YOON (Catholic Univ. of Korea, Nov. 25, 2014 –)- 367 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

Senior Visiting Scientist
Kazuhiro TANAKA (KEK)
Visiting Scientists
Toshimitsu YAMAZAKI (Univ. of Tokyo)
Mototsugu MIHARA (Osaka Univ.)
Donald George FLEMING (Univ. of British Columbia/TRIUMF)
Yasuo NOZUE (Osaka Univ.)
Takehito NAKANO (Osaka Univ.)
Tadashi ADACHI (Tohoku Univ.)
Zyun Francis EZAWA (Tohoku Univ.)
Jin NAKAMURA (Univ. of Elec.-Com.)
Yasuyuki ISHII (Tokyo Med. Univ.)
Johann ZMESKAL (SMI)
Risdiana (UNPAD)
Norimichi KOJIMA (Univ. of Tokyo)
Satoshi TSUTSUI (JASRI)
Takao SUZUKI (Shibaura Inst. of Tech.)
Masami IIO (KEK)
Georg Peter BERG (Univ. of Notre Dame)
Takayuki GOTO (Sophia Univ.)
Masaya ENOMOTO (Tokyo Univ. of Sci.)
Hiroyuki FUJIOKA (Kyoto Univ.)
Takayuki KAWAMATA (Tohoku Univ.)
Lee CHOW (UCF)
Helmut WEICK (GSI)
Harry W. K. TOM (UC Riverside)
Agustinus NUGROHO (ITB)
Kawakami Kenji ROLAND (Univ. of California, Riverside)
Ichiro SHIRAKI (Univ. of Yamanashi)
Kensuke SUZUKI (Tohoku Univ.)
Kyosuke ISODA (Tokyo Univ. of Sci.)
Ken SUZUKI (SMI)
Irwan DHARMAWAN (UNPAD)
Koji YOKOYAMA (Queen Marry Univ.)
Kazuki UENO (KEK)
Lusy SAFRIANI (UNPAD)
Hiroyuki NOUMI (Osaka Univ.)
Zhuan XU (Zhejiang Univ.)
Hiroshi TANIDA (Hiroshima Univ.)
Kenji KOJIMA (KEK)
Atsushi OKAZAWA (Univ. of Tokyo)

Tobat Parasian Irianto SARAGI (Univ. of Kassel)
Katsuhiko NISHIMURA (Univ. of Toyama)
Kenji MATSUDA (Univ. of Toyama)
Hexi SHI (Univ. of Tokyo)
Mohamed Ismail MOHAMED IBRAHIM (USM)
Shukri SULAIMAN (USM)
Kenji KAWASHIMA (Aoyama Gakuin Univ.)
Ayi BAHTIAR (UNPAD)
Koichi ICHIMURA (Hokkaido Univ.)
Youichi IGARASHI (KEK)
Makoto YOKOYAMA (Ibaraki Univ.)
Ichihiro YAMAUCHI (KEK)
KwangYong CHOI (Chung-Ang Univ.)
Peklan TOH (Univ. Sains Malaysia)
Emma HAETTNER (GSI)
Andrea VACCHI (INFN)
Eiichi YAGI (Waseda Univ.)
Yoshio KOBAYASHI (Univ. of Elec.-Com.)
Naohito SAITO (KEK)
Jun MIYAZAKI (Nihon Univ.)
Kouichirou SHIMOMURA (KEK)
Eiko TORIKAI (Univ. of Yamanashi)
Wataru HIGEMOTO (JAEA)
Yoji KOIKE (Tohoku Univ.)
Kazuhiko SATO (Saitama Univ.)
Masaru YOSOI (Osaka Univ.)
Dai TOMONO (Kyoto Univ.)
Kazuki OHISHI (Comprehensive Res. Org. for Sci. and Soc.)
Yasuhiro MIYAKE (KEK)
Prasad Tara DAS (SUNY)
Yasuhiro YAMADA (Tokyo Univ. of Sci.)
Kenya KUBO (ICU)
Tsutomu MIBE (KEK)
Hiroko ARIGA (Hokkaido Univ.)
Satoru HIRENZAKI (Nara Women's Univ.)
Yasuaki EINAGA (Keio Univ.)
Ryousuke KADONO (KEK)

Visiting Technicians
Yuya FUJIWARA (Univ. of Tokyo)
Kazuo OOYAMA (JOHO com.)

Dita PUSPITA SARI (Inst. Teknologi Sepuluh Nopember)
Retno ASIH (Insti. Teknologi Sepuluh Nopember)Research Fellows
Yuta SADA (Kyoto Univ.)

Shun ENOMOTO (Osaka Univ.)

Student Trainees
Kensuke SUZUKI (Tohoku Univ.)
Tadashi HASHIMOTO (Univ. of Tokyo) (-Mar. 31, 2014)
Takahiro NISHI (Univ. of Tokyo)
Natsuki TOMIDA (Kyoto Univ.)
Ryo SHIMIZU (Tokyo Univ. of Sci.)
Sohtaro KANDA (Univ. of Tokyo) (Apr. 1, 2014- )Kentaro INOUE (Osaka Univ.)
Yoshiki TANAKA (Univ. of Tokyo)
Hanjie GUO (Zhejiang Univ.)
Yohei MURAKAMI (Univ. of Tokyo)
Hiroyuki YAMADA (Univ. of Tokyo)
Ryo MIYATANI (Tokyo Univ. oｆ Sci.)
Kazuma SHIGA (Tokyo Univ. of Sci.)
Anba Datt PANT (Yamanashi Univ.)
Yuni WATANABE (Univ. of Tokyo)
Hiroaki KOBAYASHI (Univ. of Tokyo)
Xingliang Xu (Saga Univ.)

Masato SUZUKI (Univ. of Elec.-Com.)
Yukiko SATO (Univ. of Elec.-Com.)
Shotaro TANIGAWA (Univ. of Elec.-Com.)
Daiki NATORI (Univ. of Elec.-Com.)
Kenichi TANABE (Tokyo Univ. of Sci.)
Miho SATO (Tokyo Univ. of Sci.)
Takafumi TABATA (Tokyo Univ. of Sci.)
Malik Anjelh BAQIYA (Tohoku Univ.)
Hiroki YAMAKAMI (Kyoto Univ.)
Shinji OGAWA (Univ. of Tokyo)
Shingo KAWASAKI (Osaka Univ.)
Sajjad MARI (IUT)
Ryo KITAMURA (Univ. of Tokyo)
Fuminao HOSOMI (Univ. of Tokyo)
Kenji FUJIMURA (Ibaraki Univ.)
Taehyung KIM (Tokyo Tech.)
Shingo YASADA (Aoyama Gakuin Univ.)- 368 -

Ⅵ. RNC ACTIVITIES

Wataru ITO (Aoyama Gakuin Univ.)
Kazuki MATSUI (Sophia Univ.)
Ruidong ZHU (Univ. of Tokyo)
Ainul Fauzeeha Binti ROZLAN (Univ. Saints Malaysia)
Saidah Sakinah Binti MOHD TAJUDIN (Univ. Saints Malaysia)
Sungwon YOON (Catholic Univ., Korea)(Feb. 10, 2014 – Sep. 30, 2014)
Yoshiyuki FURUYA (Tokyo Univ. of Sci.)
Go MISHIMA (Univ. of Tokyo)
Part-time Workers
Makoto TOKUDA (Tokyo Tech.)
Abdel Jawad MAJED (Oct. 1, 2014 - )Assistants
Yuri TSUBURAI(- Apr. 30, 2014)
Mitsue YAMAMOTO (May 1, 2014- )RIKEN Accel. Prog. Rep. 48 (2015)

Kazuhiro KATONO (Hokkaido Univ.)
Shu AIKAWA (Tokyo Tech.)
Takumi YAMAGA (Osaka Univ.)
Hiroshi HORII (Univ. of Tokyo)
Kenji TANIBE (Osaka Univ.)
Kien LUU (Osaka Univ.)
Kazuya KATAYAMA (Tokyo Tech.)
Koshi KURASHIMA (Tohoku Univ.)

Taehyung KIM (Tokyo Tech.)
Yuta SADA (Kyoto Univ.) (- Mar. 31, 2014)

Yoko FUJITA- 369 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESSub Nuclear System Research Division
RIKEN-BNL Research Center
1. Abstract

The RIKEN BNL Research Center was established in April 1997 at Brookhaven National Laboratory with Professor T. D. Lee ofColumbia University as its initial Director. It is funded by the Rikagaku Kenkyusho (RIKEN, The Institute of Physical and Chemical
Research) of Japan. The Center is dedicated to the study of strong interactions, including spin physics, lattice QCD and RHIC physics
through the nurturing of a new generation of young physicists. Professor Lee was succeed by BNL Distinguished Scientist, N. P. Samios,
who served until 2013. The current director is Dr. S. H. Aronson. Support for RBRC was initially for five years and has been renewed threetimes, and presently extends to 2018. The Center is located in the Physics Department. The RBRC Theory Group activities are closely andintimately related to those of the Nuclear Theory, High Energy Theory, and Lattice Gauge Theory Groups at BNL. The RBRC
Experimental Group works closely with the DOE RHIC Spin Group, the RIKEN Spin Group at BNL, and the PHENIX heavy ion groups.
BNL provides office space, management, and administrative support. In addition, the Computer Science Center (CS) and Information
Technology Division (ITD) at BNL provides support for computing, particularly the operation and technical support for the RBRC 400
Teraflop QCDCQ (QCD Chiral Quark) lattice gauge theory computer. The Deputy Director of RBRC is R. Pisarski (BNL). L. McLerran(BNL) is leader of the Theory Group. Y. Akiba (RIKEN) is Experimental Group leader with A. Deshpande (Stony Brook) deputy. T.
Izubuchi (BNL) is Computing Group leader.

2. Major Research Subjects

Major research subjects of the theory group are(1) Heavy Ion Collision(2) Perturbative QCD(3) Phenomenological QCD
Major research subjects of the computing group are(1) Search for new law of physics through tests for Standard Model of particle and nuclear physics(2) Dynamics of QCD and related theories(3) Theoretical and algorithmic development for lattice field theories, QCD machine design
Major research subject of the experimental group are(1) Experimental Studies of the Spin Structure of the Nucleon(2) Study of Quark-Gluon Plasma at RHIC
(3) PHENIX detector upgrades

3. Summary of Research Activity

Summary of Research Activities of the three groups of the Center are given in the sections of each group.

Members
Director
Samuel H. ARONSON
Deputy Director
Robert PISARSKI
Administrative Staff
Mituru KISHIMOTO (Administration Manager, Nishina Center Planning Office)Kazunori MABUCHI (Deputy Administration Manager, Nishina Center Planning Office, – Dec. 31, 2014)
Yasutaka AKAI (Deputy Administration Manager, Nishina Center Planning Office, Jan. 1, 2015 –)Colleen MICHAEL (Administrative Assistant)
Pamela ESPOSITO (Administrative Assistant)
Taeko ITO (Administrative Assistant)- 370 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Sub Nuclear System Research Division
RIKEN-BNL Research Center
Theory Group
1. Abstract

The efforts of the RBRC theory group are concentrated on the major topics of interest in High Energy Nuclear Physics. This includes:
understanding of the Quark-Gluon Plasma; the nature of dense quark matter; the initial state in high energy collisions, the Color Glass
Condensate; its evolution through a Glasma; spin physics, as is relevant for polarized hadronic collisions; physics relevant toelectron-hadron collisions.
Theory Group hosted many joint tenure track positions with universities in U.S. and Japan.

2. Major Research Subjects
(1)
(2)
(3)

Heavy Ion Collision
Perturbative QCD
Phenomenological QCD

3. Summary of Research Activity(1) Spin Physics

The experimental program at RBRC is strongly focused on determining the origin of spin in the proton and neutron. To extract the spin
content of nucleon requires both precise data and precise computation. Dr. Jianwei Qiu of the Nuclear Theory group is one of the world’s
leading theorists in perturbative QCD, and leading the effort at BNL in spin physics. Their effort will continue to concentrate on computing
perturbative QCD effects to sufficient precision that one can reliably extract information from the evolving experimental program. In
addition they are developing ideas which might be tested in an electron-hadron collider, such as the one proposed to be built by adding anelectron ring to RHIC.

(2) Matter at High Energy Density

The RHIC experimental heavy ion program is designed to study the properties of matter at energy densities much greater than that of
atomic nuclei. This includes the initial state of nucleus-nucleus collisions, the Color Glass Condensate, the intermediate state to which it
evolves, the Glasma, and lastly the thermal state to which it evolves, the Quark-Gluon Plasma. Theorists at the RBRC have madeimportant contributions to all of these subjects.
Matter at high temperature has been studied by a variety of techniques involving both numerical and analytic methods. Much of thehigh precision work on numerical simulations of lattice QCD at nonzero temperature and density such matter have been done by membersof the Lattice Gauge Theory Group at BNL, including Frithjof Karsch, Peter Petreczsky, Swagato Mukherjee, and postdoctoral assistants.
These groups, along with collaborators at Columbia University, the University of Bielefeld, and other groups, have computed numerous
properties of QCD in thermodynamic equilibrium. This includes the equation of state for physical quark masses, susceptibilies with respect
to quark chemical potentials, and transport coefficients.
Phenomenological theories of the Quark-Gluon Plasma, based upon results from lattice simulations, have been developed by R.
Pisarski of the Nuclear Theory Group, in collaboration with Dr. Y. Hidaka (previously of RBRC/BNL, and now a permanent member at
RIKEN in Waco), Shu Lin, Daisuke Sato, and other postdoctoral research assistants at RBRC/BNL.
The theory of the Color Glass Condensate and Glasma was largely developed by RBRC scientists. This theory has been successfully
applied to a wide variety of experimental results involving high energy collisions of hadrons, electrons and nuclei. There is recent data on
heavy ion collisions that are naturally explained by such matter, including data on proton (or deuteron) nucleus collisions. Much of theeffort here will be aimed towards excluding or verifying the Color Glass Condensate and Glasma hypothesis in RHIC and LHC
experiments.
Thermal matter at high temperature and baryon density has been traditionally conjectured to be of two phases: confined anddeconfined, with a direct correlation between deconfinement and the restoration of chiral symmetry. RBRC scientists have recently
conjectured a third phase, of quarkyonic matter. This is baryonic matter at energy densities very high compared to the QCD scale. It has apressure and energy density typical of quarks, yet it is confined. The name arises because it shares properties of confined baryonic matterwith unconfined quark matter. This hypothesis is new and predicts new classes of phenomena that might be observed in collisions of nucleiof relatively low energy at RHIC. There are a number of first principle theoretical issues also to be understood.
Efforts on RHIC phenomenology proceed on a broad front. Recent efforts include improving hydrodynamic computations using stateof the art equations of state derived from lattice gauge theory. Understanding the nature of matter at high baryon number density has
generated the idea of Quarkyonic Matter, that may have implications for an upcoming low energy run at RHIC and eventual experiments inthe future at FAIR and NICA. An issue being studied is the nature of mass generation and the breaking of translational invariance. A central
focus of work at RBRC, the Color Glass Condensate and the Glasma, matter that controls the high energy limit of QCD, is being realized inexperiments at RHIC. Much activity focuses on the relation between observations at LHC and the implications made at RHIC.

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESMembers
Group Leader (Lab. Head)
Larry McLERRAN
Deputy Group Leader
Robert PISARSKI (concurrent：Deputy Director, RBRC)
RHIC Physics Fellows
Fedor BEZRUKOV
Jinfeng LIAO

Ho-Ung YEEResearch Associates
Adam BZDAK (– Apr. 30, 2014)

Daniel PITONYAKSpecial Postdoctoral Researchers
Kouji KASHIWA (– Mar. 31, 2014)

Akihiko MONNAI

Foreign Postdoctoral Researchers
Shu LIN

Sergey SYRITSYNVisiting Scientists
Testufumi HIRANO (Univ. of Tokyo)
Feng YUAN (LBNL)
Edward SHURYAK (State Univ. New York, Stony Brook)
Miklos GYULASSY (Columbia Univ.)

Robert L. JAFFE (MIT)Thomas BLUM (Univ. of Connecticut)
Taku IZUBUCHI (concurrent; Computing Gr.)- 372 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Sub Nuclear System Research Division
RIKEN-BNL Research Center
Computing Group
1. Abstract

The computing group founded in 2011 as a part of the RIKEN BNL Research Center established at Brookhaven National Laboratory
in New York, USA, and dedicated to conduct researches and developments for large scale physics computations important for particle andnuclear physics. The group was forked from the RBRC Theory Group.
The main mission of the group is to provide important numerical information that is indispensable for theoretical interpretation ofexperimental data using the theories of particle and nuclear physics. Their primary area of research is lattice quantum chromodynamics(QCD), which describes the sub-atomic structures of hadrons, which allow us the ab-initio investigation for strongly interacting quantum
field theories beyond pertrubative analysis.
The RBRC group and its collaborators have emphasized the necessity and importance of precision calculations, which will precisely
check the current understandings of nature, and will have a potential to find a physics beyond the current standard model of fundamental
physics. We have therefore adopted techniques that aim to control and reduce any systematic errors. This approach has yielded many
reliable results.
The areas of the major activities are R&D for high performance computers, developments for computing algorithms, and researches ofparticle, nuclear, and lattice theories. Since the inception of RBRC, many breakthroughs and pioneering works has carried out incomputational forefronts. These are the use of the domain-wall fermions, which preserve chiral symmetry, a key symmetry forunderstanding nature of particle nuclear physics, the three generations of QCD devoted supercomputers, pioneering works for QCD
calculation for Cabibbo-Kobayashi-Maskawa theory, QCD+QED simulation for isospin breaking, novel algorithm for error reduction in
general lattice calculation. Now the chiral quark simulation is performed at the physical up, down quark mass, the precision for many basic
quantities reached to accuracy of sub-percent, and the group is aiming for further important and challenging calculations, such as the fulland complete calaution for K→ππ decay, ε’/ε, or hadronic contributions go muon’s anomalous magnetic moment, or Nucleon’s shape andstructures.

2. Major Research Subjects
(1)

(2)
(3)

Search for new law of physics through tests for Standard Model of particle and nuclear physics, especially in the framework of the
Cabibbo–Kobayashi–Maskawa (CKM), hadronic contributions to the muon's anomalous magnetic moment (g-2).
Dynamics of QCD and related theories, including study for the structures of nucleons
Theoretical and algorithmic development for lattice field theories, QCD machine design

3. Summary of Research Activity

In 2011, QCD with Chiral Quarks (QCDCQ), a third-generation lattice QCD computer that is a pre-commercial version of IBM’s Blue
Gene/Q, was installed as an in-house computing resource at the RBRC. The computer was developed by collaboration among RBRC,
Columbia University, the University of Edinburgh, and IBM. Two racks of QCDCQ having a peak computing power of 2 × 200 TFLOPS
are in operation at the RBRC. In addition to the RBRC machine, one rack of QCDCQ is owned by BNL for wider use for scientificcomputing. In 2013, 1/2 rack of Blue Gene/Q is also installed by US-wide lattice QCD collaboration, USQCD. The group has also used the
IBM Blue Gene supercomputers located at Argonne National Laboratory and BNL (NY Blue), and RICC, the cluster computers at RIKEN(Japan), Fermi National Accelerator Laboratory, the Jefferson Lab, and others.
Such computing power enables the group to perform precise calculations using up, down, and strange quark flavors with proper
handling of the important symmetry, called chiral symmetry, that quarks have. Several projects are ongoing: flavor physics in theframework of the CKM theory for kaons and B mesons; the electromagnetic properties of hadrons; hadronic contributions to the muon’s
anomalous magnetic moment; the proton’s and neutron’s electric dipole moments; proton decay; nucleon form factors, which are related tothe proton spin problem; and QCD thermodynamics in finite temperature/density systems such as those produced in heavy-ion collisions at
the Relativistic Heavy Ion Collider. Major breakthroughs on important problems such as the direct CP violation process (K → ππ, ε′/ε ) will
be attempted using this computer.
The RBRC group and its collaborators have emphasized the necessity and importance of precision calculations, which will precisely
check the current understandings of nature, and will have a potential to find physics beyond the current standard model of fundamental
physics. We have therefore adopted techniques that aim to control and reduce any systematic errors. This approach has yielded many
reliable results.
The group also delivers an algorithmic breakthrough, which speed up generic lattice gauge theory computation typically by a factor of
20 or more. In this novel technique called All Mode Averaging (AMA), the whole calculation is divided into frequent approximatedcalculations, and infrequent expensive and accurate calculation using lattice symmetries.

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESFig.

The rack, motherboard, and chips of QCDCQMembers
Group Leader (Lab. Head)
Taku IZUBUCHI
RIKEN BNL Fellow
Tomomi ISHIKAWA (concurrent; Visiting Scientist, Univ. of Connecticut)
RHIC Physics Fellows
Brian TIBURZI
Ethan NEIL

Stefan MEINEL

Foreign Postdoctoral Researcher
Christopher KELLY
Visiting Senior Scientist
Robert MAWHINNEY (Columbia Univ.)
Visiting Scientists
Shigemi OHTA (KEK)
Yasumichi AOKI (Nagoya Univ.)
Thomas BLUM (Univ. of Connecticut)
Chulwoo JUNG (BNL)
Christoph LEHNER (BNL)

Meifeng LIN (Yale Univ.)
Eigo SHINTANI (Inst. fur Kernphysik Johannes Gutenberg-Univ. at Mainz)
Takeshi YAMAZAKI (Nagoya Univ.)
Hyung-Jin KIM (BNL)- 374 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Sub Nuclear System Research Division
RIKEN-BNL Research Center
Experimental Group
1. Abstract

RIKEN BNL Research Center (RBRC) Experimental Group studies the strong interactions (QCD) using RHIC accelerator at
Brookhaven National Laboratory, the world first heavy ion collider and polarized p+p collider. We have three major activities: Spin Physics
at RHIC, Heavy ion physics at RHIC, and detector upgrades of PHENIX experiment at RHIC. We study the spin structure of the proton
using the polarized proton-proton collisions at RHIC. This program has been promoted by RIKEN’s leadership. The first focus of theresearch is to measure the gluon spin contribution to the proton spin. Our recent data analysis has shown that the proton spin carried by thegluons is small, which is a very striking finding beyond our expectations. The aim of Heavy ion physics at RHIC is to re-create Quark
Gluon Plasma (QGP), the state of Universe just after the Big Bang. Two important discoveries, jet quenching effect and strong elliptic
flows, have established that new state of dense matter is indeed produced in heavy ion collisions at RHIC. We are now studying theproperty of the matter. Recently, we have measured direct photons in Au+Au collisions for 1<pT<3 GeV/c, where thermal radiation fromhot QGP is expected to dominate. The comparison between the data and theory calculations indicates that the initial temperature of 300
MeV to 600 MeV is achieved. These values are well above the transition temperature to QGP, which is calculated to be approximately 160
MeV by lattice QCD calculations.
We have major roles in detector upgrades of PHENIX experiment, namely, the silicon vertex tracker (VTX) and muon trigger
upgrades. Both of the upgrade is now complete. VTX detector was installed in PHENIX in 2011 and we are taking data since then. Muon
trigger was complete and it was essential for W measurement in 2013.

2. Major Research Subjects(1) Experimental Studies of the Spin Structure of the Nucleon(2) Study of Quark-Gluon Plasma at RHIC
(3) PHENIX detector upgrades

3. Summary of Research Activity

We study the strong interactions (QCD) using the RHIC accelerator at Brookhaven National Laboratory, the world first heavy ion
collider and polarized p+p collider. We have three major activities: Spin Physics at RHIC, Heavy ion physics at RHIC, and detector
upgrades of PHENIX experiment.
(1) Experimental study of spin structure of proton using RHIC polarized proton collider
How is the spin of proton formed with 3 quarks and gluons? This is a very fundamental question in Quantum Chromodynamics (QCD),
the theory of the strong nuclear forces. The RHIC Spin Project has been established as an international collaboration between RIKEN and
Brookhaven National Laboratory (BNL) to solve this problem by colliding two polarized protons for the first time in history. This project
also has extended the physics capabilities of RHIC.
The first goal of the Spin Physics program at RHIC is to determine the gluon contribution to proton spin. It is known that the spin ofquark accounts for only 25% of proton spin. The remaining 75% should be carried either by the spin of gluons or the orbital angularmomentum of quarks and gluons. One of the main goals of the RHIC spin program has been to determine the gluon spin contribution.
Before the start of RHIC, there was little experimental constraint on the gluon polarization, G.
PHENIX measures the double helicity asymmetry (ALL) of 0 production to determine the gluon polarization. Our publication from2006 run has shown that the gluon polarization in the proton is small and only about half of proton spin can be accounted by gluon spin in
the measured region of gluon momentum in proton. Figure 1 shows our most recent results of 0 ALL measurement, which has justsubmitted to Physical Review D. The figure shows the combined results of RUN5, RUN6, and RUN9. The new data give even stronger
constraint on the gluon spin. RBRC exp. G led the gluon spin analysis in PHENIX. K. Bolye, a fellow of RBRC experimental group has amajor role in this paper.
RHIC achieved polarized p+p collisions at 500 GeV in 2009. The collision energy increased to 510 GeV in 2012 and 2013. We haverecorded The main goal of these high energy p+p run is to measure anti-quark polarization via single spin asymmetry AL of the W boson
production. We have published the first results on We measurement at mid-rapidty from 2009 dataset in 2011. We upgraded the muon
trigger system to measure Wm decays in the forward direction. With the measurement of W e and W, we can cover a wide
kinematic range in anti-quark polarization measurement. The 2013 run is the main spin run at 510 GeV. PHENIX has recorded more than
150/pb of data in the run. Combined with the datasets in 2009 (8.6/pb), 2011(18/pb), and 2012(~30/pb), we will have a definite
measurement of anti-quark spin.

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESFigure 1 Double spin asymmetry ALL in 0 production as function of transverse momentum pT compared withexpectations for different gluon polarization G(x). Published in Physical Review D90,012007 (2014)(2) Experimental study of Quark-Gluon Plasma using RHIC heavy-ion collider
The goal of high energy heavy ion physics at RHIC is study of QCD in extreme conditions i.e. at very high temperature and at very
high energy density. Experimental results from RHIC have established that dense partonic matter is formed in Au+Au collisions at RHIC.
The matter is very dense and opaque, and it has almost no viscosity and behaves like a perfect fluid. These conclusions areprimarily based on the following two discoveries:
Strong suppression of high transverse momentum hadrons in central Au+Au collisions (jet quenching)Strong elliptic flow
These results are summarized in PHENIX White paper, which has over 1900 citations to date.
The focus of the research in heavy ion physics at RHIC is now to investigate the properties of the matter. RBRC have played
the leading roles in some of the most important results from PHENIX in the study of the matter properties. These include (1)measurements of heavy quark production from the single electrons from heavy flavor decay (2) measurements of J/Psi production(3) measurements of di-electron continuum and (4) measurements of direct photons.
The most important recent result is the measurement of direct photons for 1<pT<5 GeV/c in p+p and Au+Au through their internalconversion to e+e- pairs. If the dense partonic matter formed at RHIC is thermalized, it should emit thermal photons. Observationof thermal photon is direct evidence of early thermalization, and we can determine the initial temperature of the matter. It is
predicted that thermal photons from QGP phase is the dominant source of direct photons for 1<pT<3 GeV/c at the RHIC energy.
We measured the direct photon in this pT region from measurements of quasi-real virtual photons that decays into low-mass e+epairs. Strong enhancement of direct photon yield in Au+Au over the scaled p+p data has been observed. Several hydrodynamical
models can reproduce the central Au+A data within a factor of two. These models assume formation of a hot system with initial
temperature of Tinit = 300 MeV to 600 MeV. This is the first measurement of initial temperature of quark gluon plasma formed at
RHIC. These results are recently published in Physical Review Letters. Y. Akiba is the leading person of the analysis and the main
author of the paper. He received 2011 Nishina memorial Prize mainly based on this work.
(3) PHENIX detector upgrade
The group has major roles in several PHENIX detector upgrades, namely, the silicon vertex tracker (VTX) and muon trigger upgrades.
VTX is a high precision charged particle tracker made of 4 layers of silicon detectors. It is jointly funded by RIKEN and the US DOE.
The inner two layers are silicon pixel detectors and the outer two layers are silicon strip detectors. Y. Akiba is the project manager and A.
Deshpande is the strip system manager. The VTX detector was completed in November 2010 and subsequently installed in PHENIX. The
detector started taking data in the 2011 run. With the new detector, we are measuring heavy quark (charm and bottom) production in p+p,
A+A collisions to study the properties of quark-gluon plasma. We have recorded 20 billion Au+Au collisions in the 2014 run. The large
dataset will produce definitive results on heavy quark production at RHIC.
Muon trigger upgrades are needed for W measurement at 500 GeV. New trigger electronics (Muon Trigger FEE) and new Muon

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trigger detectors using RPC technology were installed in PHENIX muon arms. Additional hadron absorbers were installed in front of themuon arms to reduce the background. These upgrades were essential for the high statistic W measurement in 2013 run. Over 150/pb ofdata was recorded in the run. I. Nakagawa is the leading person of the installation of the Muon Trigger FEE, and R. Seidl have major role in
the RPC project. He is also leading the W analysis.

Figure 2 Left: a picture of West half of VTX detector installed in PHENIX experiment. The interior of the detector canbe seen. Right: The VTX detector completed with all cables, cooling tubes and dry gas connections.
(4) Other data analysis in PHENIX
PHENIX experiment has a very good capability of low mass electron pair measurement. Recently we used this capability for search for“dark photon”, a hypothetical particle in Beyond Standard Model theories. Many experiments looked for this particle since it can provide asimultaneous explanation of the 3.6 deviation of the measured value of muon anomalous magnetic moment (g-2) from its theoreticallycalculated value and the positron excess observed by PAMELLA, FERMI, and AMS-2 experiments. If dark photon exists, it decays into anelectron-positron pair, and thus it can be observed as a narrow peak inmass spectrum. We looked for this signal of dark photon in alarge sample of electron pairs measured by PHENIX experiment. We observed no significant signal of dark photon and then set the upper
limit of the dark photon – ordinary photon mixing parameter as function of mass. The result is shown in Fig. 3 below. Combined with otherexperimental limits, the parameter space of dark photon as the explanation of muon g-2 anomaly was almost completely ruled out.

Figure 3 90% CL limit of photon-dark photon mixing parameter as a function of mass. The shaded band show theparameter space favored by the muon g-2 anomaly. Accepted in Physical Review C.

Members
Group Leader (Lab. Head)
Yasuyuki AKIBA (Deputy Chief Scientist)- 377 -

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Ⅵ. RNC ACTIVITIES

Deputy Group Leader
Abhay DESHPANDE
RIKEN Spin Program Researchers
Yasushi WATANABE (concurrent: Radiation Lab.)
Yuji GOTO (concurrent: Radiation Lab.)
Itaru NAKAGAWA (concurrent: Radiation Lab.)
Takashi ICHIHARA (concurrent: RI Physics Lab.)

Atsushi TAKETANI (concurrent: Neutoron Beam Technology Team,
Advanced Photonics Technology development Group, RAP)
Satoshi YOKKAICHI (concurrent: Radiation Lab.)RIKEN BNL Fellows
Josef SEELE (– Feb. 7, 2014)

Kieran BOYLE

RHIC Physics Fellows
Xiaorong WANG

Stefan BATHE (– Jan. 31, 2015)

Special Postdoctoral Researcher
Maki KUROSAWA (– Mar. 31, 2014)
Research Associates
Chin-Hao CHEN (– Aug. 29, 2014)
RBRC Collaborating Scientists
Rachid NOUICER

Ady HERSHCOVITCH (BNL)

Visiting Scientists
Akio OGAWA (BNL)
Zheng LI

Masahiro OKAMURA (concurrent: BNL)

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Sub Nuclear System Research Division
RIKEN Facility Office at RAL
1. Abstract

Our core activities are based on the RIKEN-RAL Muon Facility located at the Rutherford Appleton Laboratory (UK), which provides
intense pulsed-muon beams. Muons have their own spins with 100% polarization, and can detect very precisely local magnetic fields andtheir fluctuations at muon stopping sites. The method to study characteristic of materials by observing time-dependent changes of muon
spin polarization is called “Muon Spin Rotation, Relaxation and Resonance (µSR method), and is applied to studies of electro-magnetic
properties of insulating, metallic, magnetic, superconducting systems. Muons reveal static and dynamic properties of electronic state ofmaterials in the zero-field condition, which is the ideal magnetic condition for researches on the magnetism. µSR is applied to thosesystems. As one example of those researches, we have carried out µSR investigations on frustrated pyrochlore systems, which havevariety of exotic ground state of magnetic spins. We are approaching to achieve the first evidence of the appearance of a quasi-monopole
state in the pyrochlore system.
We have been working on producing ultra-slow muon beam, which has a momentum spread as small as thermal energy. Our methodof the beam generation is based on the laser ionization of muoniums (bound system of µ+ and electron), which emitted from hot tungsten
surface by stopping low-momentum muon beam at Port-3. The ultra-slow muon beam can be stopped in thin foils, multi-layered materials
and artificial lattices and we can apply the µSR techniques to surface and interface science. The development of ultra-slow muon beam isalso very important as the source of ultra-cold (pencil-like small emittance) muon beam for muon g-2/EDM measurement. We have beendeveloping muonium generators to create more muoniums in vacuum even at room temperature. Very recently, we demonstrated
tremendous increase of the muonium emission efficiency by fabricating fine laser drill-holes on the surface of silica aerogel. We also
developed a high power Lyman-alpha laser in collaboration with the Advanced Photonics group at RIKEN. The new laser will ionize
muoniums 100 times more efficiently for slow muon beam generation.

2. Major Research Subjects(1) Materials science by muon-spin-relaxation method(2) Hyperfine interactions at muon sites studied by the computation science(3) Nuclear and particle physics studies via muonic atoms and ultra-cold muon beam

3. Summary of Research Activity(1) Material Science at the RIKEN-RAL Muon Facility
Muons with their own spin polarization enable us to conduct (1) material studies under external zero-field condition, (2) magnetism
studies with samples without nuclear spins, and (3) measurements of muon spin relaxation changes at wide temperature range with samedetection sensitivity. The detection time range of local field fluctuations by µSR is 10-6 to 10-11 second, which is an intermediate region
between neutron scattering method (10-10-10-12 second) and Nuclear Magnetic Resonance (NMR) (longer than 10-6 second). At Port-2 and 4of the RIKEN-RAL Muon Facility, we have been performing µSR researches on newly fabricated strong correlated-electron systems,
organic molecules and biological samples to study electron structures, superconductivity, magnetism, molecular structures and crystal
structures.
In the period from 2012 to 2014, we have obtained excellent results, and the highlights are listed in the following,
1) A static ordering of small Ir moments in the pyrochlore iridate; Nd2Ir2O7 is close to a quantum critical point.
2) A static ordering of Yb moment on the corner of the pyrochlore structure of Yb2Ti2O7 can be explained by the Higgs
mechanism.
3) Spontaneous formation of small static internal fields in the superconducting state of URu2Si2 was observed, which indicate
appearance of an exotic superconducting state in this material.
4) Universality class of the Mott transition is confirmed in EtMe3P[Pd(dmit)2]2.
5) Finding new muon sites in La2CuO4, which can only be explained by taking into account the spatial distribution of Cu spin.
6) A novel coexisting state between Fe spin-glass and Cu stripe ordered states in the over-doped regime ofLa2-xSrxCu1-yFeyO4.
7) International collaborations to organize new µSR experiments and to develop a group to work on muon-site calculations by using
computational technique.
Solid observations of a static magnetically ordered state of corner-shared magnetic moments on pyrochlore systems gave us newinterpretation to understand exotic phenomena, like the quantum criticality of magnetic moments and a quasi-magnetic monopole state(result-1 and 2). We measured an increase of static internal fields at the muon site in the zero-field condition just below thesuperconducting transition temperature of URu2Si2. This could shed a light on the mechanism of the superconductivity, which has been along-standing problem of this system (result-3). We have been developing gas-pressurized high-pressure apparatus, which can be used not
only for µSR but also for other purposes. We have applied this pressure system to EtMe3P[Pd(dmit)2]2 and have found that pressure
dependent resistivity and thermoelectric coefficient measurements have shown that the Mott transition belongs to the Ising universality- 379 -

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Ⅵ. RNC ACTIVITIES

class even in two-dimensional states (result-4). Well-known and deeply investigated La2CuO4 has opened a new scheme of the Cu spin.
Taking into account the effect of the spatial distribution of Cu spin, we have succeeded to explain newly found muon sites and hyperfine
fields at those sites (result-5). Fe spins form a spin glass state through the RKKY interaction in the over-doped regime inLa2-xSrxCu1-yFeyO4. This spin glass state is expected to co-exist with the stripe ordered state at lower temperatures(result-6).
We have been very keen to develop muon activities in Asian countries. We have formed MOU with Universiti Sains Malaysia (USM)
in order to develop activities on the muon-site calculation. We have newly started to collaborate in µSR experiments on strongly correlated
systems with researchers from Taiwan and Korea including graduate students (result-7).
A new µSR spectrometer “Chronus” which has finely multi-segmented forward and backward µ-e counter arrays (304 counters each) is
now used for real µSR experiments in Port-4 in parallel with ARGUS in Port-2. Software systems, which control the data acquisition andexperimental conditions, are renewed based on the ISIS frontend so as to have common data format with the other ISIS muon facilities(DAE with SECI), so as to have more affinity with the ISIS facility and its analysis platform.
(2) Ultra Slow (low energy) Muon Beam Generation and Applications
We are performing R&D to realize efficient generation of ultra-slow muon beam having energy dispersion below thermal energy
utilizing laser ionization of muoniums at Port-3. To study magnetism at surface and interface, and to realize new high-precision muon
g-2/EDM measurement, it is essential to increase the slow muon beam production efficiency by more than 100 times. There are three key
techniques in ultra-slow muon generation: production of thermal muonium, high intensity Lyman-alpha laser and the ultra-slow muon beamline.
In the period from 2011 to 2014, we developed a high power Lyman-alpha laser in collaboration with the Advanced Photonics group at
RIKEN. The new laser will ionize muoniums 100 times more efficiently for slow muon beam generation. This development was funded
mostly by the Grant-in-Aid for Scientific Research on Innovative Areas "Frontier in Materials, Life and Particle Science Explored by Ultra
Slow Muon Microscope". This Grant-in-Aid research group is a complex of research institutions from universities together with J-PARC
muon group and RIKEN. The new laser system was installed to J-PARC slow muon beam line and is being tested. In this development,
we succeeded to synthesize novel ceramic-based Nd:YGAG crystal, and this crystal can also be applicable to the flash-lamp based
Lyman-alpha laser system of RIKEN-RAL to realize substantial improvement of the laser power at a much reduced cost based on theexperiences.
Another plan in 2011-2014 was to realize drastic improvements on the ultra-slow muon source with much reduced emittance. We havebeen developing muonium generators to create more muoniums in vacuum even at room temperature. In 2013, we demonstrated
tremendous increase of the muonium emission efficiency by fabricating fine laser drill-holes on the surface of silica aerogel. The
measurement was carried out at TRIUMF in collaboration with J-PARC muon g-2/EDM group. We believe that the better efficiency andbeam quality can be achieved in ultra-slow muon generation by using this new muonium source.
Based on these two new key components, we are planning to feed these new techniques to RIKEN-RAL ultra-slow muon beam line torealize further development of ultra-slow muon technology. The present muonium production target section, which had been designedwith hot tungsten, was rebuilt to use advantage of the new room temperature target, such as no need of thermal shielding etc. Also, we
adopted an all-cylindrical beam-transport design, because of its simpler optics and better manufacture precision, which will contribute to
the ultimate cold muon source required for muon g-2/EDM. We plan the testing with the muon beam to be started in middle 2015.
(3) Other topics
Muon catalyzed fusion has been one of the main subject of studies since the start of the RIKEN-RAL Muon Facility. It has produced
many new results by using the advantage of the high-intensity pulsed muon beam and the advanced tritium handling facility as wasreported in previous RIKEN-RAL IACs. Even though, huge increase of the catalysis rate that is enough for energy production is yet
difficult to achieve. Considering the limited budget and human resources maintaining the tritium facility, we had discussions with RAL on
the safe closure of the tritium facility. The decommissioning was completed in March 2015.
New demand is emerging on utilizing the muon beam for electronics chips radiation effect studies. Recent progress of semiconductor
devices has produced electronics chips with very fine structure. It is concerned that the single memory upset by the ionization effect of
single muon may result in malfunction or errors of advanced electronics. Muon is the main component of the cosmic ray in our ordinal lifeand difficult to be removed. We have started measurement at RIKEN-RAL in 2013 to measure such an error rate and observed an effect thatis correlated with the muon energy deposit rate. Further measurements were performed in 2014.
A new proposal was submitted to measure the proton radius by using the hyperfine splitting of the 1S states of muonic hydrogen. This
is in contrast to the recent measurement at PSI using energy splitting between 2S-2P levels. The hyperfine transition measurement needs ahigh intensity laser so it needs to be matched with pulsed muon beam. A new laser system was designed in collaboration with RIKEN's
advanced photonics group based on their experience on the commissioning of a laser of similar type. We are also preparing the target
chamber and detectors for this measurement.

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Members
Director
Philip KING
Research & Technical Scientist
Isao WATANABE (concurrent: Advanced Meson Science Lab.)
Administration Manager
Mitsuru KISHIMOTO (concurrent: Nishina Center Planning Office)- 381 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Radioactive Isotope Physics Laboratory
1. Abstract

This laboratory explores exotic nuclear structures and dynamics in exotic nuclei that have never been investigated before, such as
those with largely imbalanced proton and neutron numbers. Our aim is to develop new experimental techniques utilizing fast RI beams todiscover new phenomena and properties in exotic nuclei. Another important subject is the equation-of-state in asymmetric nuclear matter,and its association with the origin of elements and with neutron stars. For instance, we are making attempts to the better understandunderlying mechanism for exotic stability-enhancements of very neutron-rich fluorine isotopes, the large deformation of the nucleus Mg-34
with N=22 in spite of its vicinity to the N=20 magic neutron number and anomalous collectivity in C-16. We are further extending thesestudies to medium- and heavy-mass regions by developing facilities, detectors and unique methods at RIBF, thereby leading on thechallenging task to find new exotic phenomena. We also perform numerical simulations of nucleosynthesis under the environment ofcore-collapse supernovae, and moreover quest for footprints of supernovae and solar activities in the past, embedded in Antarctic ice core.

2. Major Research Subjects
(1)

(2)
(3)

Study of structure and dynamics of exotic nuclei through developments of new tools in terms of reaction- and technique-based
methodology
Research on EOS in asymmetric nuclear matter via heavy-ion induced reactions
Detector developments for spectroscopy and reaction studies

3. Summary of Research Activity(1) In-beam gamma spectroscopy
In the medium and heavy mass region explored at RIBF, collective natures of nuclei are one of important subjects, which are obtained
through production and observation of high excited and high spin states. To populate such states, heavy-ion induced reactions such as
fragmentation, fission are useful. So far, we have developed two-step fragmentation method as an efficient method to identify and populate
excited states, and lifetime measurements to deduce transition strength.
Devices utilized for the in-beam gamma spectroscopy are ZeroDegree Spectrometer (ZDS) and a NaI array DALI2. Since the end of
2008, the first spectroscopy on nuclei island-of-inversion region was performed, we have explored step-by-step new and unknown regionsin the nuclear chart. The second campaign in 2009 was organized to study background components originating from atomic processes in aheavy target. Neutron-rich nuclei at N=20 to 28 were studied in 2010. In 2011-2013, we conducted experiment programs for Ca-54, Ni-78,
neutron-rich nuclei at N=82 and neutron-deficient nuclei at Z=50.
A multitude of data obtained with inelastic, nucleon knock-out, fragmentation channels have been analyzed and published. In
2011-2013, collective natures of Mg-36, 38 and Si-42 were both published in PRL. Excited states firstly observed in Ca-54 were reported in
Nature to demonstrate a new nuclear magic number of 34. Fragmentation reaction has been found efficient for nuclei with A>100 and
low-lying excited state in Pd-126 has been successfully observed and reported in PRC.
To further strengthen the in-beam gamma spectroscopy at RIBF, we have proposed a new setup of MINOS + DALI2 to search for the
1st excited states in even-even neutron-rich nuclei with Z~20 to 40. The program was submitted to the PAC 2013 as a new category“proposal for scientific program” and was S-ranked. A dedicated collaboration “SEASTAR” has been established as a subset of in-beamgamma collaboration “SUNFLOWER”. The two campaigns were organized in 2014 and 2015 to study very neutron-rich isotopes.
Concerning a next generation detector, a construction proposal of a LaBr3 array “SHOGUN”, was submitted to the PAC 2009, and aninternational workshop was organized in Feb. 2011 to form the SHOGUN collaboration. A technical development with small sized crystals
is now in progress.
(2) Decay spectroscopy
Beta- and isomer-spectroscopy is an efficient method for studying nuclear structure, especially for non-yrast levels. We had
accumulated experimental techniques at the RIPS facility to investigate nuclear structure in light mass region via beta-gamma and beta-pcoincidence. Concerning the medium and heavy mass region available at RIBF, we have developed two position-sensitive active-stoppers,
strip-silicon detectors and a cylindrical active stopper called CAITEN, to achieve a low-background measurement by taking correlation
between heavy ion stop position and beta-ray emission position. A site of decay-spectroscopy at the new facility of RIBF is the final focal
plane of ZDS, where high precision of TOF in particle identification is obtained due to a long flight path from BigRIPS to ZDS.
At the end of 2009, the first decay spectroscopy was organized with a minimum setup of four clover gamma detectors and silicon strip
detectors, to study neutron-rich nuclei with A~110. The first campaign was found successful and efficient to publish four letter articles in
2011, two PRL’s and two PLB’s. One of the PRL papers is associated to the r-process path where half-lives for 18 neutron-rich nuclei were
determined for the first time. The other PRL paper reported a finding of deformed magic number 64 in the Zr isotopes.
The success of the first decay-spectroscopy campaign stimulated to form a new large-scale collaboration “EURICA”, where a twelve
Euroball cluster array is coupled with the silicon-strip detectors to enhance gamma efficiency by a factor of 10. A construction proposal of“EURICA” was approved in the PAC 2011, and the commissioning was successfully organized in spring 2012. Since then, physics runs
have been conducted for programs approved to survey nuclei of interest as many as possible, such as Ni-78, Pd-128, Sn-100. So far, 10
papers including 7 PRL’s were published. One of the highlights is discovery of a seniority isomer in Pd-128, of which cascade gamma
decay gives the energy of 1st excited state and robustness of N=82 magic number.
Beta-delayed neutron emission probability of medium and heavy neutron-rich nuclei is important to understand nuclear structure andthe r-process path. In 2013, a new collaboration “BRIKEN” has been established to form a He-3 detector array. A present design of the- 382 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

array has neutron efficiency as high as 70% up to 3 MeV. The array will be coupled with the AIDA silicon strip system. A construction
proposal was approved at the PAC 2013 and two physics proposals have been approved at PAC 2014.
The CAITEN detector was successfully tested with fragments produced with a Ca-48 beam in 2010.
(3) Equation-of-state via heavy-ion central collisions
Equation-of-state in asymmetric nuclear matter is one of major subjects in physics of exotic nuclei. Pi-plus and pi-minus yields incentral heavy ion collisions at the RIBF energy are considered as one of EOS sensitive observables at the RIBF energy. To observe charged
pions, a TPC for the SAMURAI spectrometer is being constructed under an international collaboration “SπRIT”. Construction proposal
was submitted at the PAC 2012, and physics proposals were approved at the PAC 2012 and 2013. Physics runs are scheduled in 2016.
An international symposium “NuSYM” on nuclear symmetry energy was organized at RIKEN July 2010 to invite researchers in threesub-fields, nuclear structure, nuclear reaction and nuclear astrophysics, and to discuss nuclear symmetry energy together. Since then, thesymposium series have been held every year and been useful to encourage theoretical works and to strengthen the collaboration.
(4) Nucleon correlation and cluster in nuclei
Nucleon correlation and cluster in nuclei are matters of central focus in a “beyond mean-field” picture. The relevant programs within-beam gamma and missing-mass techniques are to depict nucleon condensations and correlations in nuclear media as a function of density
as well as temperature. Neutron-halo and –skin nuclei are objects to study dilute neutron matter at the surface. By changing excitationenergies in neutron-rich nuclei, clustering phenomena and role of neutrons are to be investigated.
In 2013, two programs were conducted at the SAMURAI spectrometer. One is related to proton-neutron correlation in the C-12
nucleus via p-n knockout reaction with a carbon target. The other is to search for a cluster state in C-16, which was populated via inelasticalpha scattering. The data is being analyzed.
(5) Nuclear data for nuclear waste of long-lived fission products
The nuclear waste problem is an inevitable subject in nuclear physics and nuclear engineering communities. Since the Chicago Pile
was established in 1942, nuclear energy has become one of major sources of energy. However, nowadays the nuclear waste produced atnuclear power plants has caused social problems. Minor actinide components of the waste have been studied well as a fuel in fast breeder
reactors or ADS. Long-lived fission products in waste, on the other hand, have not been studied extensively. A deep geological disposal has
been a policy of several governments, but it is difficult to find out location of the disposal station in terms of security, sociology and politics.
To solve the social problem, a scientific effort is necessary for nuclear physics community to find out efficient methods for reduction of
nuclear waste radioactivity.
In 2013, we have started up a new project to take nuclear data for transmutation of long-lived fission products to obtain cross section
data needed for designing a nuclear waste treatment system. In 2014, we made the first attempt to obtain fragmentation reaction data with
Cs-137 and Sr-90 beams at 200A MeV.
Since 2014, this activity has been intensively organized as one of the ImPACT projects by the Nuclear Transmutation Data ResearchGroup.

Members
Chief Scientist (Lab. Head)
Hiroyoshi SAKURAI (Deputy Director,RNC)
Vice Chief Scientist
Takashi ICHIHARA
Research & Technical Scientists
Yoichi NAKAI (Senior Research Scientist)
Takashi KISHIDA (Senior Research Scientist)
Shunji NISHIMURA (Senior Research Scientist)
Hideaki OTSU (Senior Research Scientist)

Tadaaki ISOBE (Research Scientist)
Hiu Ching LEE (Research Scientist)
Pieter Christiaan DOORNENBAL (Research Scientist)

Contract Researchers
Satoshi TAKEUCHI

Mizuki NISHIMURA

Postdoctoral Researchers
He WANG

Paer-Anders SOEDERSTROEM (– Jan. 31, 2014)

Foreign Postdoctoral Researchers
Giuseppe LORUSSO (– Dec. 31, 2014)

Paer-Anders SOEDERSTROEM

Research Associate
Mizuki NISHIMURA (– Mar. 31, 2014)
Research Consultants
Masayasu ISHIHARA

Hiroyuki MURAKAMI- 383 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESConsultant
Takeaki TORII (– May 2014)
International Program Associates
Xiaofei YANG (Peking Univ.)
Hongna LIU (Peking Univ.)
Jin WU (Peking Univ.)

William Barry POWELL (Univ. of Liverpool)
Sidong CHEN (Peking Univ.)

Junior Research Associates
Shintaro GO (Univ. of Tokyo)
Yoshiaki SHIGA (Rikkyo Univ.)

Noritsugu NAKATSUKA (Kyoto Univ.)
Keishi MATSUI (Univ. of Tokyo)

Part-time Worker
Zhengyu XU (Univ. of Tokyo, – Mar. 31, 2014)
Visiting Researchers
Gabor KISS (JSPS)David STEPPENBECK (JSPS)

Ann-Kathrin PERREVOORT (DFG/JSPS)

Senior Visiting Scientists
Kengo OGAWA (Chiba Univ.)

Shigeru KUBONO (Univ. of Tokyo)

Visiting Scientists
Toshiyuki SUMIKAMA (Tohoku Univ.)
Hooi Jing ONG (RCNP)
Megumi NIIKURA (Univ. of Tokyo)
Silivio CHERUBINI (Univ. of Catania)
Hyo Soon JUNG (Univ. of Notre Dame)
Daiki NISHIMURA (Tokyo Univ. of Sci.)
Nobuyuki KOBAYASHI (Univ. of Tokyo)
Naohiko OTSUKA (Intl. Atomic Energy Agency, Austria)
Giuseppe LORUSSO (National Physics Lab., UK)
Hiu Ching LEE (Univ. of Hong Kong)
Zhengyu XU (Univ. of Hong Kong)
Indranil MAZUMDAR (GSI)
Alessia Pietro DI (INFN Catania)
Pierpaolo FIGUERA (INFN Catania)
Byungsik HONG (Korea Univ.)

Prabhakar PALNI (MSU)
Rebecca SHANE (MSU)
Alan MCINTOSH (Texas A & M Univ.)
Michael YOUNG (Texas A & M Univ.)
Thomas DAVINSON (Univ. of Edinburgh)
Yassid AYYAD (Osaka Univ.)
Kathrin WIMMER (Univ. of Tokyo)
Tetsuya MURAKAMI (Kyoto Univ.)
Kazuo IEKI (Rikkyo Univ.)
Mitsunori FUKUDA (Osaka Univ.)
Nori AOI (RCNP)Le Hong KHIEM (Vietnam Academy of Sci. and Tech.)
Evgueni NIKOLSKI (RRC Kurchatov Inst.)
Alexey OGLOBLIN (RRC Kurchatov Inst.)
Hiroshi WATANABE (Beihang Univ.)

Visiting Technicians
Ivan KOJOUHAROV (GSI)
Student Trainees
Kenta YOSHINAGA (Tokyo Univ. of Sci.)
Masayuki NAGASHIMA (Niigata Univ.)
Jongwon HWANG (Seoul Nat’l Univ.)
Sunji KIM (Seoul Nat’l Univ.)
Zhengyu XU (Tokyo Univ.)
Yosuke MITSUYA (Meiji Univ.)
Yusuke MORITA (Osaka Univ.)
Junichi OHNO (Osaka Univ.)
Yasuto KAMISHOU (Osaka Univ.)
Hiroki NISHIBATA (Osaka Univ.)
Yifan ZHU (Tokyo Univ. of Sci.)
Hisaya HOTAKA (Tohoku Univ.)
Kotomi MUTO (Tohoku Univ.)
Tetsuya YAMAMOTO (Osaka Univ.)
Noritsugu NAKATSUKA (Kyoto Univ.)
Ayumi YAGI (Osaka Univ.)
Kazuma KOBAYASHI (Rikkyo Univ.)
Ryo TANIUCHI (Univ. of Tokyo)
Tomomi FUJITA (Osaka Univ.)
Takamasa YOSHIDA (Rikkyo Univ.)
Takumi USUKURA (Rikkyo Univ.)
Shunpei KINNO (Tokyo Univ. of Sci.)
Daisuke WATANABE (Univ. of Tsukuba)
Yifan FANG (Osaka Univ.)
Jin-hee CHANG (Korea Univ.)

Tomoki ISHIGAKI (Osaka Univ.)
Rie DAIDO (Osaka Univ.)
Shouta MORIMOTO (Osaka Univ.)
Keisuke TASHIRO (Niigata Univ.)
Akira HOMMA (Niigata Univ.)
Daiki MUROOKA (Niigata Univ.)
Akihiro KOJIMA (Tohoku Univ.)
Tadashi TAKO (Tohoku Univ.)
Ippei NISHIZUKA (Tohoku Univ.)
Takuya MIYAZAKI (Univ. of Tokyo)
Satoru MOMIYAMA (Univ. of Tokyo)
Mana TANAKA (Osaka Univ.)
Shintaro YAMAOKA (Osaka Univ.)
Kouta WATANABE (Osaka Univ.)
Justin Brian ESTEE (MSU)
Masanori KANEKO (Kyoto Univ.)
Hideyuki MATSUZAWA (Rikkyo Univ.)
Schrock PHILIPP (TU Darmstadt)
Hirotaka SUZUKI (Osaka Univ.)
Suwat TANGWANCHAROEN (MSU)
JungWoo LEE (Korea Univ.)
Takashi ANDO (Univ. of Tokyo)
Shunpei KOYAMA (Univ. of Tokyo)
Yuki YAMAGUCHI (Rikkyo Univ.)
Hiroyasu NAGAKURA (Rikkyo Univ.)- 384 -

Ⅵ. RNC ACTIVITIESHang DU (Osaka Univ.)
Yutaro TANAKA (Osaka Univ.)
Jiro SHIMAYA (Osaka Univ.)
Jonathan BARNEY (MSU)
Hiroyuki OIKAWA (Tokyo Univ. of Sci.)
Yoshimasa TAGUCHI (Tokyo Univ. of Sci.)
Naoya KAMBARA (Tokyo Univ. of Sci.)
Toshiki YOSHINOBU (Tokyo Univ. of Sci.)
Atsushi MIZUKAMI (Tokyo Univ. of Sci.)
Yuki KANKE (Tokyo Univ. of Sci.)
Interns
Ilias AROUEL (Universite Paris Sud XI)
Yuito AWATAGUCHI (Tokyo Met. College of Ind. Tech.)

RIKEN Accel. Prog. Rep. 48 (2015)

Junya NAGUMO (Tokyo Univ. of Sci.)
Matthew CHAPMAN (Texas A&M Univ.)
Rensheng WANG (Tsinghua Univ.)
Phong VI (Hanoi Univ. of Sci.)
Jiajian LIU (Univ. of Hong Kong)
Joachim TSCHEUSCHNER (TU Darmstadt)
Shinnosuke YOSHIDA (Osaka Univ.)
Hiroshi KANAOKA (Osaka Univ.)
Shoichiro MASUOKA (Rikkyo Univ.)
Yan ZHANG (Tsinghua Univ.)
Jonathan BARNEY (MSU)- 385 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Spin isospin Laboratory
1. Abstract

The Spin Isospin Laboratory pursues research activities putting primary focus on interplay of spin and isospin in exotic nuclei.
Investigations on isospin dependences of nuclear equation of state, spin-isospin responses of exotic nuclei, occurrence of various
correlations at low-densities, evolution of spin-orbit coupling are main subjects along the line. One of our goals is to elucidate a variety of
nuclear phenomena in terms of interplay of spin and isospin.
Establishment of storage-ring science in Japan is another big goal of our laboratory. We are leading, in collaboration with the
Wakasugi group, the Rare RI Ring project to achieve precision mass measurement of r-process nuclei.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

Direct reaction studies of neutron-matter equation of state
Study of spin-isospin responses with RI-beams
Production of spin polarized protons and its application to RI-beam experiments
R-process nucleosynthesis study with heavy-ion storage ring
Development of special targets for RI-beam experiments

3. Summary of Research Activity(1) Direct reaction studies of neutron matter equation of state
Direct reactions induced by light-ions serve as powerful tools to investigate various aspects of nuclei. We are advancing experimental
programs to explore equation of state of neutron matter, via light-ion induced reactions with RI-beams.
(1-a) Determination of a neutron skin thickness by proton elastic scattering
A neutron skin thickness is known to have strong relevance to asymmetry terms of nuclear equation of state, especially to a term
proportional to density. The ESPRI project aims at determining density distributions in exotic nuclei precisely by proton elastic scattering at
200−300 MeV/nucleon. An experiment for 132Sn that is a flagship in this project is planned to be performed in 2015. Prior to the 132Sn
experiment, we have applied the ESPRI setup that consists of a solid hydrogen target and recoil proton detectors to 16C in 2012.
(1-b) Asymmetry terms in nuclear incompressibility
Nuclear incompressibility represents stiffness of nuclear matter. Incompressibility of symmetric nuclear matter is determined to be
230±20 MeV, but its isospin dependence still has a large uncertainty at present. A direct approach to the incompressibility of asymmetricnuclear matter is an experimental determination of energies of isoscalar giant monopole resonances (GMR) in heavy nuclei. We havedeveloped, in close collaboration with Center for Nuclear Study (CNS) of University of Tokyo, an active gas target for deuteron inelastic
scattering experiments to determine GMR energies. The active gas target has been already tested with oxygen and xenon beams at HIMAC
and will be applied to a 132Sn experiment in 2015.
(1-c) Multi-neutron andα-cluster correlations at low densities
Occurrences of multi-neutron andα-cluster correlations are other interesting aspects of nuclear matter and define its low-density
behavior. The multi-neutron andα-cluster correlations can be investigated with the large-acceptance SAMURAI spectrometer. The
SAMURAI has been already applied to experiments to explore light neutron-rich nuclei close to the dripline. We plan to reinforce
experimental capabilities of the SAMURAI by introducing advanced devices such as MINOS (Saclay) and NeuLAND (GSI).
(1-d) Fission barrier heights in neutron-rich heavy nuclei
The symmetry energy has a strong influence on fission barrier heights in neutron-rich nuclei. Knowledge on the fission barrier heights,
which is quite poor at present, is quite important for our proper understanding on termination of the r-process. We are planning to perform,in collaboration with the TU Munich group, (p,2p)-delayed fission experiments at the SAMURAI to determine the fission barrier heights inneutron-rich nuclei in Pb region.
(2) Study of spin-isospin responses with RI-beams
The study of spin-isospin responses in nuclei forms one of the important cores of nuclear physics. A variety of collective states, forexample isovector giant dipole resonances, isobaric analogue states, Gamow-Teller resonances, have been extensively studied by use ofelectromagnetic and hadronic reactions from stable targets.
The research opportunities can be largely enhanced with light of availabilities of radioactive isotope (RI) beams and of physics of
unstable nuclei. There are three possible directions to proceed. The first direction is studies of spin-isospin responses of unstable nuclei via
inverse-kinematics charge exchange reactions. A neutron-detector array WINDS has been constructed, under a collaboration of CNS, Tokyoand RIKEN, for inverse kinematics (p,n) experiments at the RI Beam Factory. We have already applied WINDS to the (p,n) experiments for
12Be, 132Sn and plan to extend this kind of study to other exotic nuclei.
The second direction is studies with RI-beam induced charge exchange reaction. RI-beam induced reactions have unique properties
which are missing in stable-beam induced reactions and can be used to reach the yet-to-be-discovered states. We have constructed the
SHARAQ spectrometer and the high-resolution beam-line at the RI Beam Factory to pursue the capabilities of RI-beam induced reactions
as new probes to nuclei. One of the highlights is an observation of β+ type isovector spin monopole resonances (IVSMR) in 208Pb and 90Zr
via the (t, 3He) reaction at 300 MeV/nucleon.
The third direction is studies of neutron- and proton-rich nuclei via stable-beam induced charge exchange reactions, which is
conducted under collaboration with Research Center for Nuclear Physics (RCNP), Osaka University. We have performed the double charge
exchange 12C(18O, 18Ne)12Be reaction at 80 MeV/nucleon to investigate structure of a neutron-rich 12Be nucleus. Peaks corresponding to- 386 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

ground and excited levels in 12Be have been clearly observed.
(3) Production of spin-polarized protons and its application to RI-beam experiments
Recent experimental and theoretical studies have revealed that spin degrees of freedom play a vital role in exotic nuclei. Tensor force
effects on the evolution of shell and possible occurrence of p-n pairing in the proton-rich region are good examples of manifestations ofspin degrees of freedom.
In exploring the spin effects in exotic nuclei, scattering with polarized protons should be a powerful tool. We have constructed a novel
polarized proton solid target aiming to shed light of polarization on the physics of exotic nuclei. A distinguished feature of the target systemis that it works under a low magnetic field of 0.1 T and temperature higher than 100 K, which exhibits a striking contrast to standard DNPtargets working in extreme conditions of several Tesla and sub-Kelvin. It should be noted that we have recently achieved a proton
polarization of 40% at room temperature in a pentacene-d14 doped p-terphenyl crystal.
The polarized proton target was applied, for the first time, to measurement of vector analyzing power in the proton elastic scattering of
neutron-rich 6,8He nuclei at 71 MeV/nucleon at RIPS, RIKEN. At RI Beam Factory, a hole-state spectroscopy via the (p, 2p) knockout
reaction from unstable oxygen isotopes was performed with the polarized target.
(4) R-process nucleosynthesis study with heavy-ion storage ring
Most of the r-process nuclei become within reach of experimental studies for the first time at RI Beam Factory at RIKEN. The Rare RI
Ring at RIBF is the unique facility with which we can perform mass measurements of r-process nuclei. Construction of the Rare RI Ringstarted in FY2012 in collaboration with Tsukuba and Saitama Universities. A major part of the ring has been completed and thecommissioning run is planned in FY2014.
We are planning to start precise mass measurements of r-process nuclei in 2015. A series of experiments will start with nuclei in the
A=80 region and will be extended to heavier region.
(5) Development of special targets for RI-beam experiments
For the research activities shown above, we are developing and hosting special targets for RI-beam experiments listed below:a) Polarized proton targetb) Thin solid hydrogen targetc) MINOS (developed at Saclay and hosted by the Spin Isospin Laboratory)

Members
Chief Scientist (Lab. Head)Tomohiro UESAKA
Research & Technical Scientists
Ken-ichiro YONEDA (Senior Research Scientist,
concurrent ; Team Leader, User Support Office)
Masaki SASANO (Research Scientist)

Juzo ZENIHIRO (Research Scientist)
Sarah NAIMI (Research Scientist, Apr. 1, 2014 –)Contract Researcher
Daisuke NAGAE (Jan. 1, 2015 –)Special Postdoctoral Researchers
Masami SAKO

Yuma KIKUCHI

Postdoctoral Researchers
Masanori DOZONO (– Mar. 31, 2014)
Kenichiro TATEISHI (Apr. 1, 2014 –)Valerii PANIN

Research Associate
Kenichiro TATEISHI (– Mar. 31, 2014)
Junior Research Associates
CheongSoo LEE (Univ. of Tokyo)
Fumi SUZAKI (Saitama Univ.)

Keiichi KISAMORI (Univ. of Tokyo)
Yuki KUBOTA (Univ. of Tokyo)

International Program Associates
Zhengyang TIAN (Peking Univ., Apr. 15, 2014 – Oct. 14, 2014)
Chao WEN (Peking Univ.)
Sergey CHEBOTARYOV (Kyungpook Nat’l Univ.)
Evgeniy Vladimirovich MILMAN (Kyungpook Nat’l Univ.)

Clementine Angelique Marie SANTAMARIA (Univ. Paris Sud XI, – Sep.
30, 2014)
Sebastian Benedict REICHERT (TUM, Aug. 1, 2014 – Nov 10, 2014)
Dahee KIM (Ewha Womans Univ., Oct. 1, 2014 –)Part-time Worker
Tomomi KAWAHARA (– Jul. 31, 2014)
Research Consultant
Harutaka SAKAGUCHI- 387 -

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Ⅵ. RNC ACTIVITIESVisiting Researchers
Alexandre OBERTELLI (CEA Saclay, – May 1, 2014)
Dennis MUECHER (JSPS Fellow, Apr. 1, 2014 – Jun. 6, 2014)

Stuhl LASZLO (JSPS Fellow, Apr. 15, 2014 –)Senior Visiting Scientists
Didier BEAUMEL (IPN)

Hiroyuki SAGAWA (Aizu Univ.)

Visiting Scientists
Didier BEAUMEL (IPN)
Yosuke KONDO (Tokyo Tech.)Elekes ZOLTAN (Atomki)
Hidetoshi AKIMUNE (Konan Univ.)
Yohei MATSUDA (Osaka Univ.)
Yasuhiro TOGANO (Tokyo Tech.)
Satoshi SAKAGUCHI (Kyusyu Univ.)
Kenjiro MIKI (Osaka Univ.)
Valerie LAPOUX (CEA Saclay)
Alexandre OBERTELLI (CEA Saclay)
Alain GILLIBERT (CEA Saclay)
Emanuel POLLACCO (CEA Saclay)
Anna CORSI (CEA Saclay)
Dennis MUECHER (TUM)

Yury LITVINOV (GSI)
Yuhu ZHANG (CAS)
Igor GASPARIC (Ruder Boskovic Inst. Zagreb Croatia)
Hans Toshihide TOERNQVIST (TU Darmstadt)
Christoph CAESAR (GSI)
Haik SIMON (GSI)
Matthias HOLL (TU Darmstadt)
Takayuki YAMAGUCHI (Saitama Univ.)
Takashi NAKAMURA (Tokyo Tech.)Atsushi TAMII (Osaka Univ.)
Attila KRASZNAHORKAY (ATOMKI)
Takashi WAKUI (Tohoku Univ.)
Kimiko SAKAGUCHI (Tohoku Univ.)

Visiting Technicians
Tomomi KAWAHARA (Toho Univ.)
Gilles AUTHELET (CEA Saclay)
Jean-Marc GHELLER (CEA Saclay)
Cedric PERON (CEA Saclay)
Jean-Yves ROUSSE (CEA Saclay)
Denis CALVET (CEA Saclay)

Alan PEYAUD (CEA Saclay)
Alain DELBART (CEA Saclay)
Frederic CHATEAU (CEA Saclay)
Caroline LAHONDE-HAMDOUN (CEA Saclay)
Arnaud GIGANON (CEA Saclay)
Daniel KOERPER (GSI)

Student Trainees
Shota FUKUOKA (Univ. of Tsukuba)
Zhengyang TIAN (Peking Univ.)
Ryogo MINAKATA (Tokyo Tech.)
Yasunori WADA (Tohoku Univ.)
Takahiro TAGUCHI (Tohoku Univ.)
Shun OGOSHI (Tokyo Tech.)
Tatsuya FURUNO (Kyoto Univ.)
Tatsuo BABA (Kyoto Univ.)
Miho TSUMURA (Kyoto Univ.)
Jumpei YASUDA (Kyushu Univ.)
Taku FUKUNAGA (Kyushu Univ.)
Naruki INABA (Univ. of Tsukuba)
Yuuta SHIOKAWA (Tohoku Univ.)
Shuhei GOTANDA (Univ. of Miyazaki)
Yoshihisa KANAYA (Univ. of Miyazaki)
Junpei KOUNO (Saitama Univ.)
Satoshi MATSUNAGA (Saitama Univ.)
Yuki ISHII (Kyoto Univ.)
Mizuki SHIKATA (Tokyo Tech.)
Junichi TSUBOTA (Tokyo Tech.)
Miduki ONO (Saitama Univ.)
Chihiro SHIMURA (Saitama Univ.)
Yuuki TAKEUCHI (Saitama Univ.)
Syunichirou OHMIKA (Saitama Univ.)

Hiroshi MIURA (Saitama Univ.)
Takuma NISHIMURA (Saitama Univ.)
Motoki MURATA (Kyoto Univ.)
Kazuki SAWAHATA (Tokyo Tech.)
Clementine Angelique Marie SANTAMARIA (Univ.Paris Sud XI)
Syunsuke KAWAKAMI (Miyazaki Univ.)
Daijiro ETO (Tohoku Univ.)
Junki TANAKA (Osaka Univ.)
Sebastian Benedikt REICHERT (TU Munchen)
Tomoyuki OZAKI (Tokyo Tech.)Atsumi SAITO (Tokyo Tech.)
Yasutaka NISHIO (Kyushu Univ.)
Yusuke SHINDO (Kyushu Univ.)
Munemi TABATA (Kyushu Univ.)
Atomu WATANABE (Tohoku Univ.)
Ayaka OHKURA (Kyushu Univ.)
Yukina ICHIKAWA (Univ. of Tsukuba)
Xiangcheng CHEN (Univ. of Heidelberg)
Kotaro YAMADA (Toho Univ.)
Tomoaki KANEKO (Toho Univ.)
Julian KAHLBOW (TU Darmstadt)
Robert KISSEL (TU Darmstadt)
Gregor DENTINGER (TU Darmstadt)
Taras LOKOTKO (Univ. of Hong Kong)

Interns
Raphael SAISEAU (Univ. Paris Sud XI)
Zhuang GE (IMP, CAS)

Lily SIEGENBERG (Univ. of Surrey)

Assistants
Emiko ISOGAI
Yu NAYA

Yuri TSUBURAI- 388 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Nuclear Spectroscopy Laboratory
1. Abstract

The research group has conducted nuclear-physics studies utilizing stopped/slowed-down radioactive-isotope (RI) beams mainly at
the RIBF facility. These studies are based on the technique of nuclear spectroscopy such as β-ray-detected NMR, γ-PAD (Perturbed Angular
Distribution), laser, and Mӧssbauer among other methods that takes advantage of intrinsic nuclear properties such as nuclear spins,
electromagnetic moments, and decay modes. In particular, techniques and devices for the production of spin-controlled RI beams have beendeveloped and combined to the spectroscopic studies, which enable high-sensitivity measurements of spin precessions/resonances through achange in the angular distribution of radiations. Anomalous nuclear structures and properties of far unstable nuclei are investigated fromthus determined spin-related observables. The group also aim to apply such techniques to interdisciplinary fields such as fundamental
physics and materials science by exploiting nuclear probes.

2. Major Research Subjects(1) Nuclear spectroscopy with stopped/slowed-down RI beams(2) R&D studies on the production of spin-oriented RI beam(3) Application of RI probes(4) Fundamental physics: Study of symmetry

3. Summary of Research Activity(1) Nuclear spectroscopy with stopped/slowed-down RI beams
Measurements of static electromagnetic nuclear moments over a substantial region of the nuclear chart have been conducted forstructure studies on the nuclei far from the β-decay stability. Utilizing nuclear spin orientation phenomena of RIs created in the
projectile-fragmentation reaction, ground- and excited-state nuclear moments of nuclei far from the stability have been determined bymeans of the β-ray-detected nuclear magnetic resonance (β-NMR) and the γ-ray time differential perturbed angular distribution (γ-TDPAD)
methods. To extend these observations to extremely rare RIs, a new method has been developed based on the laser spectroscopy whichmakes use of characteristic atomic properties of RIs surrounded by liquid helium.
(2) R&D studies on the production of spin-oriented RI beams
A new method has been developed for controlling spin in a system of rare RIs, taking advantage of the mechanism of the two-step
projectile fragmentation reaction combined with the momentum-dispersion matching technique. This success allows us to utilize
spin-controlled world's highest intensity rare RIBs delivered from BigRIPS for researches on the nuclear structure of species situatedoutside the traditional region of the nuclear chart. In parallel with this work, the development of a new apparatus to produce highly
spin-polarized RI beams will be conducted by extending the atomic beam resonance method to fragmentation-based RI beams.
(3) Application of RI probes
The application of RI and heavy ion beams as a probe for condensed matter studies is also conducted by the group. The microscopic
material dynamics and properties have been investigated through the deduced internal local fields and the spin relaxation of RI probes
based on various spectroscopies utilizing RI probes such as the β-NMR/nuclear quadrupole resonance (NQR) methods, in-beam Mӧssbauer
spectroscopy and the γ-ray time differential perturbed angular correlation (γ-TDPAC) spectroscopy.
(4) Fundamental physics: Study of symmetry
The nuclear spins of stable and unstable isotopes sometimes play important roles in fundamental physics research. New experimental
methods and devices have been developed for studies of the violation of time reversal symmetry (T-violation) using spin-polarized nuclei.
These experiments aim to detect the small frequency shift in the spin precession arising from new mechanisms beyond the Standard Model.

Members
Chief Scientist (Lab. Head)
Hideki UENO
Research & Technical Scientists
Aiko NAKAO (Senior Research Scientist)
Hiroki YAMAZAKI (Senior Research Scientist)

Yuichi ICHIKAWA (Research Scientist)

Research Consultant
Takuya OKADA
Junior Research Associates
Yoko ISHIBASHI (Univ. of Tsukuba, – Mar. 31, 2014)

Kei IMAMURA (Meiji Univ.)- 389 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESYuichi OHTOMO (TIT, – Feb. 28, 2015)
Part-time Worker
Yoko ISHIBASHI (Univ. of Tsukuba, Sep. 1, 2014 –)Senior Visiting Scientist
Yukari MATSUO (Hosei Univ.)
Visiting Scientists
Wataru SATO (Kanazawa Univ.)
Kensaku MATSUTA (Osaka Univ.)
Jin NAKAMURA (Univ. of Elec.-Com.)
Atsushi HATAKEYAMA (Tokyo Univ. of Agric. and Tech.)Takeshi FURUKAWA (Tokyo Met. Univ.)
Satoshi TSUTSUI (JASRI)
Takamasa MOMOSE (Kyoto Univ.)
Jean-Michel DAUGAS (CEA)
Xiaolong WANG (Kyoto Univ.)

Yoshio KOBAYASHI (Univ. of Elec.-Com.)
Jiro MURATA (Rikkyo Univ.)
Koichiro ASAHI (TIT)
Jun MIYAZAKI (Tokyo Univ. of Agric. and Tech.)
Yasuhiro YAMADA (Tokyo Univ. of Sci.)
Kenya KUBO (ICU)
Akihiro YOSHIMI (Okayama Univ.)
Yukari MATSUO (Hosei Univ.)
Yasuaki EINAGA (Keio Univ.)

Student Trainees
Yoko ISHIBASHI (Univ. of Tsukuba)
Masato TSUCHIYA (Tokyo Tech.)
Hazuki SHIRAI (Tokyo Tech.)
Miki HAYASAKA (Tokyo Gakugei Univ.)
Ryo MIYATANI (Tokyo Univ. of Sci.)
Kazuma SHIGA (Tokyo Univ. of Sci.)
Tomomi FUJITA (Osaka Univ.)
Yuichi OHTOMO (Tokyo Tech)
Takahiro SUZUKI (Tokyo Tech)
Masaomi TANAKA (Osaka Univ.)
Ryosuke KANBE (Osaka Univ.)
Yu SAKAMOTO (Tokyo Tech)
Yukiko SATO (Univ. of Elec.-Com.)
Shotaro TANIGAWA (Univ. of Elec.-Com.)
Daiki NATORI (Univ. of Elec.-Com.)
Kenichi TANABE (Tokyo Univ. of Sci.)
Miho SATO (Tokyo Univ. of Sci.)
Takafumi TABATA (Tokyo Univ. of Sci.)
Tsubasa SAGAYAMA (Tokyo Gakugei Univ.)

Shota KISHI (Tokyo Gakugei Univ.)
Yuki KANNO (Tokyo Tech.)
Shuichiro KOJIMA (Tokyo Tech.)Tomoya SATO (Tokyo Tech.)
Aleksey GLADKOV (Kyungpook Nat’l Univ.)
Yonggeun SEON (Kyungpook Nat’l Univ.)
Daiki TOMINAGA (Hosei Univ.)
Syouhei OOSIRO (Tokyo Gakugei Univ.)
Miku MATSUMOTO (Tokyo Gakugei Univ.)
Ryo OGAWA (Univ. of Elec.-Com.)
Yusuke HAMABE (Univ. of Elec.-Com.)
Ippei KUBONO (Tokyo Univ. of Sci.)
Shota AMAGASA (Tokyo Univ. of Sci.)
Chikako FUNAYAMA (Tokyo Tech)
Chika HIRAO (Tokyo Tech)
Taro KOMINE (Tokyo Tech)
Tsuyoshi EGAMI (Hosei Univ.)
Takafumi KAWAGUCHI (Hosei Univ.)

Interns
ZheWei YIN (Peking Univ.)
Hoi Io KONG (Peking Univ.)
Jing MA (Peking Univ.)
Zong Hao LI (Peking Univ.)
Bo WANG (Peking Univ.)

Hyunsuk CHOI (Seoul Nat’l Univ.)
Hangil CHOI (Seoul Nat’l Univ.)
Sangbaek LEE (Seoul Nat’l Univ.)
Honggi JEON (Seoul Nat’l Univ.)
Hakrim KIM (Seoul Nat’l Univ.)- 390 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research DivisionHigh Energy Astrophysics Laboratory
1. Abstract

In the immediate aftermath of the Big Bang, the beginning of our universe, only hydrogen and helium existed. However, nuclear
fusion in the interior of stars and the explosion of supernovae in the universe over the course of 13.8 billion years led to the evolution of aworld brimming with the many different elements we have today. By using man-made satellites to observe X-rays and gamma-rays emitted
from celestial objects, we are observing the synthesis of the elements at their actual source. Our goal is to comprehensively elucidate thescenarios for the formation of the elements in the universe, together with our research on sub-atomic physics through the use of anaccelerator.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Nucleosynthesis in Stars and Supernovae
Particle Acceleration Mechanism in Astronomical Objects
Physics in Extremely Strong Magnetism and Gravity
Research and Development of Innovative X-ray and Gamma-ray detectors

3. Summary of Research Activity

High Energy Astrophysics Laboratory started on April 2010. The goal of our research is to reveal the mechanism of nucleosynthesis in
the universe, and to observe exotic physical phenomena in extremely strong magnetic and/or gravitational field. We have observed
supernova remnants, strongly magnetized neutron stars, pulsars, black holes and galaxies with X-ray astronomical satellites.
We showed that the expansion of ejecta in Tycho's supernova remnant was consistent with a spherically symmetric shell, based on
Suzaku (Japanese X-ray observatory) measurements of the Doppler broadened X-ray emission lines. This is the first direct measurement of
the expansion velocity of the elements produced in the thermonuclear expansion supernova. This information tells us the stratified structureof the elements, implying that the heavier elements such as Fe are produced deeper interior of the explosion.
We discovered the emission line of aluminum in supernova remnant G344.7-0.1 for the first time. Aluminum is produced in theneutron rich environment of supernova explosions. We also found manganese, which is enriched in the environment of neutron excess, insome supernova remnants. A systematic study of those lines emitted from the neutron rich elements will be a good tool to explore thenucleosynthesis in the interior of star explosions.
High-energy X-rays from radioactive Ti-44, which is a direct tracer of the supernova blast, was first imaged with the focusing
telescope, NuSTAR. The map of Ti-44 in Cassiopeia A does not show spherical or axial symmetry, but asymmetry, supporting a mildly
asymmetric explosion model with low-mode convection. This is the first astronomical image with nuclear gamma-rays and newobservational evidence to understand the mechanism of supernova explosion and nucleosynthesis.
Gamma-ray emission up to 10 MeV was detected from thundercloud, suggesting that the detected gamma-rays were produced byrelativistic electrons via bremsstrahlung. Those relativistic electrons are probably accelerated through an electrical potential difference inthe thundercloud. This observation gives us a hint of the particle acceleration probably occurred near the neutron stars.
We continue to construct the Gravity and Extreme Magnetism Small Explorer (GEMS) under the collaboration with NASA Goddard
Space Flight Center (USA). GEMS is the first dedicated satellite for the X-ray polarimetry, which is opening a new field in Astrophysics
and Astronomy. The construction of an engineering model and basic performance studies of an X-ray polarimeter were carried out in
FY2010, and the semiflight model of the detector was built in FY2012 and tested in FY2013. Unfortunately, NASA stops the GEMS
project due to an expected cost overrun in 2012, but we will repropose the mission in 2014 with some modification. RIKEN will become aco-principal investigator institute and takes more responsibility on the X-ray polarimeter system and science.

Members
Associate Chief Scientist (Lab. Head)
Toru TAMAGAWA
Contract Researcher
Goro SATO (– Mar. 31, 2014)

Yuki OKURA (Jun. 1, 2014 –)Special Postdoctoral Researchers
Asami HAYATO
Satoru KATSUDA (– Mar. 31, 2014)
Shin'ya YAMADA (– Mar. 31, 2014)

Kumi ISHIKAWA
Hirofumi NODA (Apr. 1, 2014 –)Takayuki YUASA (Apr. 1, 2014 –)Postdoctoral Researcher
Takao KITAGUCHI
Part-time Workers
Fumi ASAMI (– Jul. 31, 2014)

Rie YOSHII- 391 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

Megu KUBOTA

Shigeru ENDO (– Feb. 28, 2014)

Visiting Researchers
Wataru IWAKIRI (JSPS Fellow, Saitama Univ.)

Teruaki ENOTO (JSPS Fellow, Stanford Univ.)

Visiting Scientists
Yukikatsu TERADA (Saitama Univ.)
Yujin NAKAGAWA (Waseda Univ.)
Masaki WAKABAYASHI (Jakulin Commercial Company LC)
Aya BAMBA (JAXA)
Naohisa INADA (Univ. of Tokyo)
Rohta TAKAHASHI (Tomakomai Nat'l College of Tech.)

Toru MISAWA (Shinshu Univ.)
Hiroya YAMAGUCHI (Harvard Univ.)
Satoru KATSUDA (JAXA)
Shin'ya YAMADA (Tokyo Met. Univ.)
Takao KITAGUCHI (Hiroshima Univ.)
Harufumi TSUCHIYA (JAEA)

Student Trainees
Rie YOSHII (Tokyo Univ. of Sci.)
Fumi ASAMI (Tokyo Univ. of Sci.)
Akifumi YOSHIKAWA (Tokyo Univ. of Sci.)
Yoko TAKEUCHI (Tokyo Univ. of Sci.)

Kenta KANEKO (Kogakuin Univ.)
Megu KUBOTA (Tokyo Univ. of Sci.)
Kazuki NISHIDA (Tokyo Univ. of Sci.)- 392 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Astro-Glaciology Research Unit
Our Astro-Glaciology Research Unit promotes both theoretical and experimental studies to open up a new interdisciplinary research
field between astrophysics and glaciology. On the theoretical side, we numerically simulate:(1) Changes in the chemical composition of the stratosphere induced by high-energy photons and/or particles emitted from explosive
astronomical phenomena, such as solar proton events and galactic supernovae, and(2) The explosive nucleosynthesis, including the rapid neutron capture process (the r-process) for the creation of the elements heavier
than iron, arising in the environment of core-collapse supernova explosions.
Subjects (1) and (2) themselves are very important in solar–terrestrial research and nuclear astrophysics, respectively; furthermore, theitems (1) and (2) are intended to be coupled with experimental studies described below.
On the experimental side, we analyze ice cores drilled at the Dome Fuji station in Antarctica in collaboration with National Institute ofPolar Research, Tokyo. These ice cores correspond to time capsules of the past. In particular, the ice cores obtained at Dome Fuji are known
to be unique because they contain much more information on conditions in the stratosphere than any other ice cores recovered from otherlocations in either hemisphere. This means that the Dome Fuji ice cores may have an original advantage to study astronomical phenomenaof the past, since gamma-rays and high-energy protons emitted from astronomical events affect the chemical and isotopic compositions inthe stratosphere and not those in the troposphere. Accordingly, we measure:(3) Variations in the nitrate ion (NO3-) concentrations in the ice cores, in order to seek the proxy of past solar activity and the footprints
of supernovae in our galaxy,(4) Variations in the water isotopes (18O and 2H) in the ice cores, in order to reconstruct past temperature changes on the earth, and(5) Variations in the nitrate isotope (15N) in the ice cores, in order to investigate the possibility of this isotope becoming a new and amore stable proxy for solar activity and/or galactic supernovae.
Items (3), (4), and (5) have been analyzed with Dome Fuji ice cores with a temporal resolution of about 1 year. By comparing theresults for items (3) and (4), we aim to understand the correlation between solar activity and climate changes in the past on the millennium
scale. The basis for item (4) is already established in glaciology. Item (5) will be the one of very first measurements taken in ice cores. The
theoretical studies related to items (1) and (2) will provide a background for distinguishing the characteristics of the astronomical eventsfrom meteorological noise that usually appears in the ice core data. Finally, we note that the supernova rate in our galaxy is crucial tounderstand the r-process nucleosynthesis but yet remains unknown. Our item (3) is also intended to diagnose the galactic supernova rate
ultimately.

Members
Research Unit Leader (Lab. Head)
Yuko MOTIZUKI
Research & Technical Scientists
Kazuya TAKAHASHI (Concurrent: Senior Research Scientist)

Yoichi NAKAI (Concurrent: Senior Research Scientist)

Postdoctoral Researcher
Sachiko OKAMOTO
Part-time Workers
Ai SHIMADA (TANEICHI) (– May 31, 2014)
Keiko FUKUSHIMA (WATANABE) (– Nov. 30, 2014)

Manami MARUYAMA
Yuma HASEBE (Saitama Univ., Nov. 1, 2014 –)Visiting Scientists
Akira HORI (Kitami Inst. of Tech.)
Hideharu AKIYOSHI (Nat‘l Inst. for Environ. Studies)

Hideki MADOKORO (Mitsubishi Heavy Ind., Ltd.)

Student Trainees
Yuma HASEBE (Saitama Univ.)- 393 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Research Group for Superheavy Element
1. Abstract

The elements with their atomic number Z>103 are called as trans-actinide or superheavy elements. The chemical properties of thoseelements have not yet been studied in detail. Those elements do not exist in nature. Therefore, they must be produced by artificially for thescientific study of those elements. In our laboratory, we have been studying the physical and chemical properties of the superheavy
elements utilizing the accelerators in RIKEN and various methods of efficient production of the superheavy elements.

2. Major Research Subjects
(1)
(2)
(3)
(4)

Search for new superheavy elements
Decay spectroscopy of the heaviest nuclei
Study of the chemical properties of the heaviest elements
Study of the reaction mechanism of the fusion process (theory)

3. Summary of Research Activity(1) Searching for new elements
To expand the periodic table of elements and the nuclear chart, we will search for new elements.
(2) Spectroscopic study of the nucleus of heavy elements
Using the high sensitivity system for detecting the heaviest element, we plan to perform a spectroscopic study of nuclei of the heavy
elements.
(3) Chemistry of superheavy elements
Study of chemistry of the trans-actinide (superheavy element) has just started world-wide, making it a new frontier in the field ofchemistry. Relativistic effects in chemical property are predicted by many theoretical studies. We will try to develop this new field.
(4) Study of a reaction mechanism for fusion process
Superheavy elements have been produced by complete fusion reaction of two heavy nuclei. However, the reaction mechanism of thefusion process is still not well understood theoretically. When we design an experiment to synthesize nuclei of the superheavy elements, weneed to determine a beam-target combination and the most appropriate reaction energy. This is when the theory becomes important. We will
try to develop a reaction theory useful in designing an experiment by collaborating with the theorists.
(5) Research Highlight
The discovery of a new element is one of the exciting topics both for nuclear physicists and nuclear chemists. The elements with their
atomic number Z>103 are called as trans-actinides or superheavy elements. The chemical properties of those elements have not yet beenstudied in detail. Since those elements do not exist in nature, they must be produced by artificially, by using nuclear reactions for the studyof those elements. Because the production rate of atoms of those elements is extremely small, an efficient production and collection are key
issues of the superheavy research. In our laboratory, we have been trying to produce new elements, studying the physical and chemical
properties of the superheavy elements utilizing the accelerators in RIKEN.
Although the Research Group for Superheavy element has started at April 2013, the Group is a renewal of the Superheay Element
Laboratory started at April 2006, based on a research group which belonged to the RIKEN accelerator research facility (RARF), and hadstudied the productions of the heaviest elements. The main experimental apparatus is a gas-filled recoil ion separator GARIS. The heaviest
elements with their atomic numbers, 107 (Bohrium), 108 (Hassium), 109 (Meitnerium), 110 (Darmstadtium), 111 (Roentogenium), and 112(not yet named) were discovered as new elements at Helmholtzzentrum für Schwerionenforschung GmbH (GSI), Germany by using 208Pb
or 209Bi based complete fusion reactions, so called “cold fusion” reactions. We have made independent confirmations of the productions ofisotopes of 108th, 110th, 111th, and 112th elements by using the same reactions performed at GSI. After these work, we observed an isotopeof the 113th element, 278113, in July 2004, in April, 2005, and in August 2012. The isotope, 278113, has both the largest atomic number, (Z =113) and atomic mass number (A = 278) which have determined experimentally among the isotopes which have been produced by cold
fusion reactions. We could show the world highest sensitivity for production and detection of the superheavy elements by theseobservations.
We decided to make one more recoil separator GARIS-II, which has an acceptance twice as large as existing GARIS, in order torealize higher sensitivity. The design of GARIS-II has finished in 2008. All fabrication of the separator will be finished at the end of fiscal
year 2008. It will be ready for operation in fiscal year 2009 after some commissioning works.
Preparatory work for the study of the chemical properties of the superheavy elements has started by using the gas-jet transport system
coupled to GARIS. The experiment was quite successful. The background radioactivity of unwanted reaction products has been highly
suppressed. Without using the recoil separator upstream the gas-jet transport system, large amount of unwanted radioactivity strongly
prevents the unique identification of the event of our interest. This new technique makes clean and clear studies of chemistry of the heaviest
elements promising.
The spectroscopic study of the heaviest elements has started by using alpha spectrometry. New isotope, 263Hs (Z=108), which has thesmallest atomic mass number ever observed among the Hassium isotopes, had discovered in the study. New spectroscopic information for
264Hs and its daughters have obtained also. The spectroscopic study of Rutherfordium isotope 261Rf (Z=104) has done and 1.9-s isomericstate has directly produced for the first time.
Preparatory works for the study of the new superheavy elements with atomic number 119 and 120 have started in 2013. We measured
the reaction products of the 248Cm(48Ca, xn)296-xLv(Z=116) previously studied by Frelov Laboratory of Nuclear Reaction, Russia, and GSI.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

We observed 5 isotopes in total which tentatively assigned to 293Lv, and 292Lv.

Members
Group Director
Kosuke MORITA
International Program Associate
Christian BERNER (TUM, Aug. 1, 2014 – Nov. 10, 2014)
Visiting Scientist
Kunihiro FUJITA (Kyushu Univ.)
Student Trainees
Shoya YAMAMOTO (Kyushu Univ.)
Taiki TANAKA (Kyushu Univ.)

Yoshihiro NARIKIYO (Kyushu Univ.)
Reii KAKU (Kyushu Univ.)- 395 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Research Group for Superheavy Element
Superheavy Element Production TeamFor this year, see the section of Research Group for Superheavy Element.

Members
Team Leader
Kosuke MORITA (concurrent; Group Director, Research Group for Superheavy Element)
Research & Technical Scientist
Kouji MORIMOTO (Senior Research Scientist, concurrent; Team Leader, Superheavy Element Device Development Team)
Nishina Center Technical Scientists
Akira YONEDA
Daiya KAJI (concurrent; Superheavy Element Device Development Team)Special Postdoctoral Researcher
Yasuo WAKABAYASHI (Univ. of Tokyo)
Research Consultant
Kenji KATORI
Junior Research Associate
Mirei TAKEYAMA (Yamagata Univ.)
Part-time Worker
Kengo TANAKA (Tokyo Univ. of Sci.)
Visiting Scientists
Hiroyuki KOURA (JAEA)
Benoit Jean-Paul GALL (Strasbourg Univ.)

Marc ASFARI (Institut Pluridisciplinaire Hubert Curien)Student Trainees
Yukiko KOMORI (Osaka Univ.)
Takuya YOKOKITA (Osaka Univ.)

Kengo TANAKA (Tokyo Univ. of Sci.)- 396 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Research Group for Superheavy Element
Superheavy Element Research Device Development Team
1. Abstract

A gas-filled recoil ion separator has been used as a main experimental device for the study of superheavy elements. This team is incharge of maintain, improve, develop and operate the separators and rerated devices. There are two gas-filled recoil ion separators installed
at RILAC experimental hall. One is GARIS that is designed for symmetric reaction such as cold-fusion reaction, and the other is newly
developed GARIS-II that is designed for asymmetric reaction such as hot-fusion reaction. New element 278113 were produced by 70Zn +209
Bi reaction using GARIS. Further the new element search Z > 118 are preparing by using GARIS-II.

2. Major Research Subjects
(1)
(2)
(3)

Maintenance of GARIS and development of new gas-filled recoil ion separator GARIS-II.
Maintenance and development of detector and DAQ system for GARIS and GARIS-II.
Maintenance and development of target system for GARIS and GARIS-II.

3. Summary of Research Activity

The GARIS-II is newly developed which has an acceptance twice as large as existing GARIS, in order to realize higher sensitivity. It
will be ready for operation in fiscal year 2014 after some commissioning works. We will also offer user-support if a researcher wishes to
use the devices for his/her own research program.
Members
Team Leader
Kouji MORIMOTO
Nishina Center Research Scientist
Daiya KAJI
Nishina Center Technical Scientist
Akira YONEDA (concurrent; Superheavy Element Production Team)
Junior Research Associate
Sayaka YAMAKI (Saitama Univ., Apr. 1, 2014 –)Part-time Worker
Sayaka YAMAKI (– Mar. 31, 2014)
Visiting Scientists
Fuyuki TOKANAI (Yamagata Univ.)

Sayaka YAMAKI (Saitama Univ.)- 397 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Nuclear Transmutation Data Research Group
1. Abstract

The disposal of high-level radioactive wastes from nuclear power plants is a problem considered to be one of the most important issues atboth national and international levels. As a fundamental solution to the problem, the establishment of nuclear transmutation technology
where long-lived nuclides can be changed to short-lived or stable ones will be vital. Progress in R & D in the transmutation of long-lived
fission products (LLFP) in the nuclear wastes however, has been slow. Our group aims to obtain reaction data of LLFP at RIBF and otherfacilities which may lead to a new discovery and invention for peaceful use of nuclear power and the welfare of humanity.

2. Major Research Subjects

The Group is formed by three research teams. The first two Teams, “Fast RI Data Team” and “Slow RI Data Team”, are in charge of
proton- and deuteron-induced reaction data of LLFP in inverse kinematics at RIBF. The third Team “Muon Data Team” is to obtain muon
capture data of LLFP at muon facilities. All of the teams are focusing to obtain high-quality data which are essentially necessary toestablish reliable reaction models. Each team has its own subjects and promotes LLFP reaction programs based on their large experiences,
techniques and skills.

3. Summary of Research Activity

In 2014, all the teams polished up experimental strategies, formed collaboration and prepared experiments.

Members
Group Director
Hiroyoshi SAKURAI (concurrent: Chief Scientist, RI Physics Lab.)- 398 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Nuclear Transmutation Data Research Group
Fast RI Data Team
1. Abstract

Fast RI team aims at obtaining and accumulating the cross section data for long lived fission products (LLFPs) in order to explore thepossibility of using accelerator for nuclear transmutation.
LLFPs as nuclear waste have been generated continuously in nuclear power plants for wealth for human lives, while people noticed theway of disposal has not necessarily been established, especially after the Fukushima Daiichi power plant disaster. One of the ways toreduce the amount of LLFP or to recover them as recycled resources is nuclear transmutation technique.
RIBF facility has a property to generate such LLFP as a secondary beam and the beam species are identified by event by event. Utilizing
the property, absolute values of the cross section of various reactions on LLFPs are measured and accumulated as database.

2. Major Research Subjects

1) Measurement of reaction products by the interaction of LLFPs with proton, deuteron, and photon to explore candidate reactions fortransmutation of LLFPs.
2) Evaluation of the cross section data for the neutron induced reactions from the obtained data.

3. Summary of Research Activity

1) Acting as collaboration hub on many groups which plan to take data using fast RI beam in RIBF facility.
2) Concentrating on take data for proton and deuteron induced spallation reactions with inverse kinematics.
3) Accumulating the cross section data and evaluating them as evaluated nuclear data.
4) Evaluating cross section of neutron induced reaction on LLFP by collaborating with the nuclear model calculation and evaluation group.

Members
Team Leader
Hideaki OTSU (Oct. 1, 2014−, concurrent: Team Leader, SAMURAI Team)Technical Staff I
Nobuyuki CHIGA (Jan. 1, 2015−)
Student Trainees
Shouhei ARAKI (Kyushu Univ.)

Tatsuya YAMAMOTO (Miyazaki Univ.)- 399 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Nuclear Transmutation Data Research Group
Slow RI Data Team
1. Abstract

This team is in charge of the development of low-energy RI beams of long-lived fission fragments (LLFP) from the 238U by means ofdegrading the energy of beams produced by the BigRIPS fragment separator.

2. Major Research Subjects

Studies of the energy degradation and purification of RI beams are the main subjects of the team. Developments of devices used forthe energy degradation of RI beams are also an important subject.

3. Summary of Research Activity

1) Study and development of the energy degradation methods for LLFP.
2) Development of the devices used for the energy degradation.
3) Operation of the BigRIPS separator and supply the low energy LLFP beam to the experiment in which the cross sections of LLFP aremeasured at the low energy.
Members
Team Leader
Koichi YOSHIDA (concurrent: BigRIPS Team)- 400 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Nuclear Transmutation Data Research Group
Muon Data Team
1. Abstract

Dr. Yoshio Nishina observed muons in cosmic rays in 1937. The muon is an elementary particle belonging to electron group, and is 207
times as heavy as electron. The muon has positive or negative electric charge, and the lifetime is 2.2 μsec. The negative muon is caught bya nucleus (atomic number: Z) in materials to form a muonic atom, and is then captured by the nucleus. The negative muon is combinedwith a proton to form a neutron and a neutrino to create an excited state of the nucleus with the atomic number of Z-1, followed byemissions of neutrons and gamma rays. The muon nuclear capture reaction produces the isotopes of the (Z-1) nucleus. However, thereaction mechanism is not yet well clarified. The research team aims at obtaining the experimental data to understand the mechanism ofmuon nuclear capture reactions as well as at establishing the reaction theory.

2. Major Research Subjects(1) Experimental clarification on reaction mechanism of nuclear muon-capture(2) Establishment of reaction theory on nuclear muon-capture(3) Interdisciplinary applications of nuclear muon-capture reactions

3. Summary of Research Activity

Members
Team Leader
Hiroyoshi SAKURAI (Oct. 1, 2014 – Nov. 30, 2014, concurrent: Chief Scientist, RI Physics Lab.)
Teiichiro MATSUZAKI (Dec. 1, 2014 –)- 401 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
High-Intensity Accelerator R&D Group
1. Abstract

The R&D group, consisting of two teams, develops elemental technology of high-power accelerators and high-power targets, aiming at
future applications to nuclear transmutations of long-lived fission product into short-lived nuclides. The research subjects aresuperconducting rf cavities for low-velocity ions, design of high-power accelerators, high-power target systems and related technologies.

2. Major Research Subjects(1) R&D of elemental technology of high-power accelerators and high-power targets

3. Summary of Research Activity(1) Based on the discussion with other research groups, R&D study of various accelerator components and elements is under progress.

Members
Group Director
Osamu KAMIGAITO (concurrent: Chief Scientist, Group Director, Accelerator Gr.)- 402 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
High-Intensity Accelerator R&D Group
High-Gradient Cavity R&D Team
Members
Team Leader
Naruhiko SAKAMOTO (concurrent: Cyclotron Team)
Research & Technical Scientists
Kazunari YAMADA (Senior Technical Scientist, concurrent: Beam Dynamics & Diagnostics Team)
Kazutaka OHZEKI (Technical Scientist, concurrent: Cyclotron Team)- 403 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
High-Intensity Accelerator R&D Group
High-Power Target R&D Team
Members
Team Leader
Hiroki OKUNO (concurrent: Deputy Group Director, Accelerator Gr.)- 404 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Accelerator Group
1. Abstract

The accelerator group, consisting of seven teams, pursues various upgrade programs of the world-leading heavy-ion accelerator
facility, RI-Beam Factory (RIBF), to enhance the accelerator performance and operation efficiency. The programs include the R&D of
superconducting ECR ion source, charge stripping systems, beam diagnostic devices, radiofrequency systems, control systems, and beamsimulation studies. We are also maintaining the large infrastructure to realize effective operation of the RIBF, and are actively promoting
the applications of the facility to a variety of research fields.
Our primary mission is to supply intense, stable heavy-ion beams for the users through effective operation, maintenance, and upgradeof the RIBF accelerators and related infrastructure. The director members shown below govern the development programs that are not dealt
with by a single group, such as intensity upgrade and effective operation. We also promote the future plans of the RIBF accelerators alongwith other laboratories belonging to the RIBF research division.

2. Major Research Subjects(1) Intensity upgrade of RIBF accelerators (Okuno)(2) Effective and stable operation of RIBF accelerators (Fukunishi)(3) Operation and maintenance of infrastructures for RIBF (Kase)(4) Promotion of the future plan (Kamigaito, Fukunishi, Okuno)

3. Summary of Activity(1) The maximum intensity of the calcium beam reached 530 pnA at 345 MeV/u, which corresponds to 8.8 kW.
(2) The maximum intensity of the uranium beam reached 28 pnA at 345 MeV/u.
(3) The overall beam availability for the RIBF experiments in 2014 reached 92 %.
(4) The large infrastructure was properly maintained based on a well-organized cooperation among the related sections.
(5) An intensity-upgrade plan of the RIBF has been further investigated, mainly on the design of a new superconducting linac.

Members
Group Director
Osamu KAMIGAITO
Deputy Group Directors
Hiroki OKUNO (Intensity upgrade)
Nobuhisa FUKUNISHI (Stable and efficient operation)
Masayuki KASE (Energy-efficiency management)
Research Consultant
Tadashi FUJINAWA (– Mar. 31, 2015)
International Program Associate
Vasileios TZOGANIS (Univ. of Liverpool)
Visiting Researchers
Akira GOTO (Yamagata Univ.)

Toshiyuki HATTORI (Tokyo Tech.)

Assistant
Karen SAKUMA- 405 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Accelerator Group
Accelerator R&D Team
1. Abstract

We are developing the key hardware in upgrading the RIBF accelerator complex. Our primary focus and research is charge stripper
which plays an essential role in the RIBF accelerator complex. Charge strippers remove many electrons in ions and realize efficient
acceleration of heavy ions by greatly enhancing charge state. The intensity of uranium beams is limited by the lifetime of the carbon foil
stripper conventionally installed in the acceleration chain. The improvement of stripper lifetimes is essential to increase beam power
towards the final goal of RIBF in the future. We are developing the low-Z gas stripper. In general gas stripper is free from the lifetime
related problems but gives low equilibrium charge state because of the lack of density effect. Low-Z gas stripper, however, can give as highequilibrium charge state as that in carbon foil because of the suppression of the electron capture process. Another our focus is the upgradeof the world's first superconducting ring cyclotron.

2. Major Research Subjects
(1)
(2)
(3)

Development of charge strippers for high power beams (foil, low-Z gas)
Upgrade of the superconducting ring cyclotron
Maintenance and R&D of the electrostatic deflection/inflection channels for the beam extraction/injection

3. Summary of Research Activity(1) Development of charge strippers for high power beams (foil, low-Z gas)
(Hasebe, H., Imao, H. Okuno., H.)
We are developing the charge strippers for high intensity heavy ion beams. We are focusing on the developments on carbon or
berrilium foils and gas strippers including He gas stripper.
(2) Upgrade of the superconducting ring cyclotron(Ohnishi, J., Okuno, H.)
We are focusing on the upgrade of the superconducting ring cyclotron.
(3) Maintenance and R&D of the electrostatic deflection/inflection channels for the beam extraction/injection(Ohnishi, J., Okuno, H.)
We are developing high-performance electrostatic channels for high power beam injection and extraction.

Members
Team Leader
Hiroki OKUNO (concurrent: Deputy Group Director, Accelerator Gr.)
Research & Technical Scientists
Hiroshi IMAO (Senior Research Scientist)

Jun-ichi OHNISHI (Senior Technical Scientist)

Nishina Center Technical Scientist
Hiroo HASEBE
Special Postdoctoral Researcher
Hironori KUBOKI (– Mar. 31, 2013)
Visiting Scientists
Andreas ADELMANN (PSI)
Hironori KUBOKI (KEK)

Noriyosu HAYASHIZAKI (Tokyo Tech.)- 406 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Accelerator GroupIon Source Team
1. Abstract

Our aim is to operate and develop the ECR ion sources for the accelerator-complex system of the RI Beam Factory. We focus on
further upgrading the performance of the RI Beam Factory through the design and fabrication of a superconducting ECR ion source for
production of high-intensity uranium ions.

2. Major Research Subjects(1)(2)

Operation and development of the ECR ion sources
Development of a superconducting ECR heavy-ion source for production of high-intensity uranium ion beams

3. Summary of Research Activity(1) Operation and development of ECR ion sources(T. Nakagawa, M. Kidera, Y. Higurashi, K. Ozeki, T. Nagatomo, H. Haba, and T. Kageyama)
We routinely produce and supply various kinds of heavy ions such as zinc and calcium ions for the super-heavy element searchexperiment as well as uranium ions for RIBF experiments. We also perform R&D’s to meet the requirements for stable supply ofhigh-intensity heavy ion beams.
(2) Development of a superconducting ECR ion source for use in production of a high-intensity uranium ion beam
(T. Nakagawa, J. Ohnishi, M. Kidera, Y. Higurashi, K. Ozeki and T. Nagatomo)
The RIBF is required to supply uranium ion beams with very high intensity so as to produce RI’s. We have designed and are
fabricating an ECR ion source with high magnetic field and high microwave- frequency, since the existing ECR ion sources have theirlimits in beam intensity. The coils of this ion source are designed to be superconducting for the production of high magnetic field. We arealso designing the low-energy beam transport line of the superconducting ECR ion source.

Members
Team Leader
Takahide NAKAGAWA
Research & Technical Scientist
Takashi NAGATOMO (Technical Scientist)
Nishina Center Research Scientists
Masanori KIDERA

Yoshihide HIGURASHI

Contract Researcher
Kazutaka OHZEKI (– Sept. 30, 2014)
Special Postdoctoral Researcher
Tatsuya URABE (Apr. 1, 2014 –)Postdoctoral Researcher
Tatsuya URABE (– Mar. 31, 2014)
Research Consultant
Tadashi KAGEYAMA (Apr. 1, 2014 –)Temporary Employee
Tadashi KAGEYAMA (– Mar. 31, 2014)
Part-time Worker
Yumi KURAMITSU- 407 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Accelerator GroupRILAC Team
1. Abstract

The operation and maintenance of the RIKEN Heavy-ion Linac (RILAC) have been carried out. There are two operation modes: one is
the stand-alone mode operation and the other is the injection mode operation. The RILAC has been used especially as an injector for the
RIKEN RI- Beam Factory accelerator complex. The RILAC is composed of the ECR ion source, the frequency-variable RFQ linac, six
frequency-variable main linac cavities, and six energy booster cavities (CSM).

2. Major Research Subjects(1) The long term high stability of the RILAC operation.
(2) Improvement of high efficiency of the RILAC operation.

3. Summary of Research Activity

The RILAC was started to supply ion beams for experiments in 1981. Thousands hours are spent in a year for delivering many kindsof heavy-ion beams to various experiments.
The RILAC has two operation modes: one is the stand-alone mode operation delivering low-energy beams directly to experiments andthe other is the injection mode operation injecting beams into the RRC. In the first mode, the RILAC supplies a very important beam to the
nuclear physics experiment of “the research of super heavy elements”. In the second mode, the RILAC plays a very important role as
upstream end of the RIBF accelerator complex.
The maintenance of these devices is extremely important in order to keep the log-term high stability and high efficiency of the RILAC
beams. Therefore, improvements are always carried out for the purpose of more stable and more efficient operation.

Members
Team Leader
Eiji IKEZAWA
Research & Technical Scientist
Yutaka WATANABE (Senior Technical Scientist)
Research Consultants
Masatake HEMMI

Toshiya CHIBA- 408 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Accelerator Group
Cyclotron Team
1. Abstract

Together with other teams of Nishina Center accelerator division, maintaining and improving the RIBF cyclotron complex. The
accelerator provides high intensity heavy ions. Our mission is to have stable operation of cyclotrons for high power beam operation.
Recently stabilization of the rf system is a key issue to provide 10 kW heavy ion beam.

2. Major Research Subjects(1) RF technology for Cyclotrons(2) Operation of RIBF cyclotron complex(3) Maintenance and improvement of RIBF cyclotrons(4) Single turn operation for polarized deuteron beams(5) Development of superconducting cavity

3. Summary of Research Activity

Development of the rf system for a reliable operation
Development of highly stabilized low level rf system
Development of superconducting cavity
Development of the intermediate-energy polarized deuteron beams.

Members
Team Leader
Naruhiko SAKAMOTO
Research & Technical Scientist
Kazutaka OHZEKI (Technical Scientist)
Nishina Center Research Scientist
Kenji SUDA
Research Consultant
Yoshiaki CHIBA
Visiting Technician
Yan CONG (IMP, CAS)

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Accelerator GroupBeam Dynamics & Diagnostics Team
1. Abstract

The cascaded cyclotrons used in RIKEN RI Beam Factory (RIBF) requires not only strict matching of operation parameters but alsohigh stability of all the accelerator components in order to establish stable operation of the world’s most intense heavy-ion beams. Beam
Dynamics and Diagnostics Team is responsible for power supplies, beam instrumentation, computer control and beam dynamic of the RIBF
accelerator complex and strongly contributes to the performance upgrade of the RIBF.

2. Major Research Subjects(1) Seeking the best operation method of the RIBF accelerator complex based on the beam dynamics study.
(2) Maintenance and development of the beam instrumentation, especially non-destructive monitors.
(3) Upgrade of the computer control system of the RIBF accelerator complex.
(4) Maintenance and improvements of the magnets and power supplies.
(5) Developments of beam interlock system suited to high-power cyclotron complex.

3. Summary of Research Activity(1) The world-first beam current monitor with a high-Tc current sensor and SQUID has been developed.
(2) The bending power of the fixed-frequency Ring Cyclotron has been upgraded to 700 MeV. It enables us to accelerate 238U64+ ionsobtained by the helium gas stripper and contributes to stable and high-intensity operation of RIBF.
(3) An EPICS-based control system and a homemade beam interlock system have been stably working. Replacement of the existing legacy
control system used in the old half of our facility is ongoing. Construction of the new control system for the new injector RILAC2 was
successfully completed, where the embedded EPICS system running on F3RP61-2L CPU module, developed by KEK and RIKEN
control group, was used.
(4) We replaced some dated power supplies of RIKEN Ring Cyclotron by new ones, which have better long-term stability than the old ones.
The other existing power supplies (~900) are stably operated owing to elaborate maintenance work.
(5) We have contributed to RILAC2 construction, especially in its beam diagnosis, control system, magnet power supplies, vacuum system,high-energy beam transport system etc.

Members
Team Leader
Nobuhisa FUKUNISHI (concurrent; Deputy Group Director, Accelerator Gr.)
Research & Technical Scientists
Masaki FUJIMAKI (Senior Technical Scientist)
Keiko KUMAGAI (Senior Technical Scientist)

Tamaki WATANABE (Senior Technical Scientist)
Kazunari YAMADA (Senior Technical Scientist)

Nishina Center Technical Scientists
Misaki KOMIYAMA

Akito UCHIYAMA

Special Postdoctoral Researcher
Takuya MAEYAMA
Temporary Employee
Part-time Workers
Yuki SHIRAISHI

Makoto NAGASE

Visiting Scientists
Kenichi ISHIKAWA (Univ. of Tokyo)
Shin-ichiro Hayashi (Hiroshima Int’l Univ.)

Hiromichi RYUTO (Kyoto Univ.)

Visiting Technician
Jun-ichi ODAGIRI (KEK)- 410 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Accelerator Group
Cryogenic Technology Team
1. Abstract

We are operating the cryogenic system for the superconducting ring cyclotron in RIBF. We are operating the helium cryogenic systemin the south area of RIKEN Wako campus and delivering the liquid helium to users in RIKEN. We are trying to collect efficiently gas
helium after usage of liquid helium.

2. Major Research Subjects

(1)
(2)

Operation of the cryogenic system for the superconducting ring cyclotron in RIBF
Operation of the helium cryogenic plant in the south area of Wako campus and delivering the liquid helium to users in Wako campus.

3. Summary of Research Activity(1)(2)

Operation of the cryogenic system for the superconducting ring cyclotron in RIBF
(Okuno, H., Dantsuka, T., Nakamura, M., Maie, T.,)
Operation of the helium cryogenic plant in the south area of Wako campus and delivering the liquid helium to users in Wako campus.
(Dantsuka, T., Tsuruma, S., Okuno, H.).

Members
Team Leader
Hiroki OKUNO (concurrent: Deputy Group Director, Accelerator Gr.)
Research & Technical Scientist
Masato NAKAMURA (Senior Technical Scientist)
Nishina Center Technical Scientist
Takeshi MAIE
Technical Staff I
Tomoyuki DANTSUKA
Temporary Employee
Kumio IKEGAMI (– Mar. 31, 2014)
Research Consultant
Kumio IKEGAMI (Apr. 1, 2014 –)Part-time Worker
Shizuho TSURUMA- 411 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Accelerator Group
Infrastructure Management Team
1. Abstract

The RIBF facility is consisting of many accelerators and its infrastructure is very important in order to make an efficient operation of
RIBF project. We are maintaining the infrastructure of the whole system and to support the accelerator operation with high performance.
We are also concerning the contracts of gas- and electricity-supply companies according to the annual operation plan. The contracts should
be reasonable and also flexible against a possible change of operations. And we are searching the sources of inefficiency in the operationand trying to solve them for the high-stable machine operation.

2. Major Research Subjects

(1)
(2)
(3)

Operation and maintenance of infrastructure for RIBF accelerators.
Renewal of the old equipment for the efficient operation.
Support of accelerator operations.

Members
Team Leader
Masayuki KASE (concurrent; Deputy Group Director, Accelerator Gr.)
Research & Technical Scientists
Shu WATANABE (Senior Technical Scientist)

Hideyuki YAMASAWA (Manager)

Temporary Employee
Tadashi FUJINAWA (– Mar. 31, 2014)
Research Consultant
Shin-ichi WATANABE
Visiting Scientist
Hideshi MUTO (Tokyo Univ. of Sci. Suwa)- 412 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Instrumentation Development Group
1. Abstract

This group develops core experimental installations at the RI Beam factory. Experimental installations currently under setting up
include common elements enabling multiple-use (SLOWRI), as well as others that are highly program specific (SCRIT and Rare-RI Ring).
All were designed to maximize the research potential of the world's most intense RI beams, made possible by the exclusive equipment
available at the RI Beam Factory. Beam manipulation techniques, such as a beam accumulation and a beam cooling, will be able to provide
opportunities of new experimental challenges and the foundation for future developments of RIBF.

2. Major Research Subjects(1) SCRIT Project(2) SLOWRI Project(3) Rear RI Ring Project

3. Summary of Research Activity

We are developing beam manipulation technology in carrying out above listed project. They are the high-quality slow RI beam
production (SCRIT and SLOWRI), the beam cooling and stopping (SCRIT and SLOWRI), and the beam accumulation technology (Rare RIRing). The technological knowhow accumulated in our projects will play a significant role in the next generation RIBF. Status and future
plan for each project is described in subsections. SCRIT is now under finalizing the experimental setup for electron scattering off unstable
nuclei, and the comprehensive test will be soon. The first experiment will be planed in 2015. Rare RI Ring construction has been almost
completed. Test experiments using alpha particle for evaluating the ring performance were successfully performed, and the isochronism inthe order of 10-5 was confirmed in ten-turns circulation. The first commissioning experiment is planed in June 2015. Construction of the
SLOWRI system was completed in 2014, and it is now under setting up for the first commissioning in 2015.

Members
Group Director
Masanori WAKASUGI
Senior Visiting Scientist
Akira OZAWA (Univ. of Tsukuba)Student Trainees
Mamoru TOGASAKI (Rikkyo Univ.)
Yohei SUMI (Rikkyo Univ.)

Saki MATSUO (Rikkyo Univ.)
Kohei YAMADA (Rikkyo Univ.)- 413 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Instrumentation Development GroupSLOWRI Team
1. Abstract

Construction of a next-generation stopped and low-energy radioactive ion beam facility (SLOWRI) which will provide low-energy,
high-purity and small emittance ion beams of all elements has been started in FY2013 as one of the principal facilities at the RIKEN
RI-beam factory (RIBF). High-energy radioactive ion beams from the projectile fragment separator BigRIPS are thermalized in a large He
gas catcher cell (RFC cell) or in a small Ar gas catcher cell (PALIS cell). In the RFC cell, thermalized ions in buffer gas are guided andextracted to a vacuum environment by a combination of dc electric fields and inhomogeneous rf fields (rf carpet ion guide). The PALIS cell
will be placed in the vicinity of the second focal plane slits of BigRIPS and can be used continuously during other experiments. From thesegas cells, the low-energy ion beams will be delivered via mass separators and switchyards to various devices: such as an ion trap, acollinear fast beam apparatus, and a multi-reflection time of flight mass spectrograph. In the R&D works at the present ring cyclotron
facility, an extraction efficiency of 33% for a 100A MeV 8Li ion beam from the projectile fragment separator RIPS was achieved and thedependence of the efficiency on the ion beam intensity was investigated.
First spectroscopy experiment at the prototype SLOWI was performed on Be isotopes. Energetic ions of 7,10,11Be from the RIPS weretrapped and laser cooled in a linear rf trap and precision spectroscopy was performed. The evaluated ion temperature of <10 mK
demonstrates that a reduction of more than 15 orders of magnitude for the kinetic energy of radioactive Be was achieved online. The
ground state hyperfine constants of all Be isotopes have been measured precisely by laser and microwave. These precision measurements
will be used to confirm the anomalous mean radius of the valence neutron of the so called neutron halo nucleus. Other laser spectroscopy
experiments using the slow RI-beams are also under progress in off-line setups. A collinear fast beam apparatus for nuclear charge-radiimeasurements was build and tested with stable Ar+ ion beams.
A multi-reflection time-of-flight mass spectrograph (MRTOF) has been developed and tested online for radioactive lithium isotope,
8
Li. A high mass resolving power of 170,000 has been obtained for an isobaric doublet of 40K and 40Ca with a very short flight time of 2 ms.
This performance allowed accurate mass determination of <10-7 accuracy by a single isobaric reference. Two mass measurement projects
using MRTOF mass spectrographs have been started: one is for trans uranium elements at the GARIS facility and the other is for r-process
nuclides at SLOWRI facility.
Resonance ionization spectroscopy has been tested during the offline development of PALIS gas cell. Stable isotopes of Co, Cu, Fe,
Ni, Ti, Nb, Sn, In, and Pd were resonantly ionized by excimer pumped dye lasers or Nd:YAG laser pumped Ti:Sapphire lasers with theprototype gas cell setup. The resonance spectra are in many cases sufficient to resolve the hyperfine structures. Nuclear spins and magnetic
moments will be determined for various isotopes obtained during other experiments.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)

Construction of stopped and low-energy RI-beam facility, SLOWRI.
Laser spectroscopy of trapped radioactive Beryllium isotopes.
Development of a multi-reflection time-of-flight mass spectrograph for precision mass measurements of short-lived nuclei.
Development of parasitic slow RI-beam production method using resonance laser ionization.
Development of ion-surfing gas cell.

3. Summary of Research Activity(1) Construction of stopped and low-energy RI-beam facility (SLOWRI)(WADA, Michiharu, SONODA, Tetsu, KATAYAMA, Ichiro, SCHURY, Peter, ITO, Yuta, ARAI, Fumiya, ARAI, Shigeaki, KUBO,
Toshiyuki, KUSAKA, Kensuke, FUJINAWA Tadashi, MAIE Takeshi, YAMASAWA Hideyuki, WOLLNIK, Hermann,)
Installation of SLOWRI has been started in FY2013. It consists of two gas catchers (RF Carpet gas cell and PALIS gas cell), mass
separators a 50-m beam transport line, a beam cooler-buncher, an isobar separator, and a laser system. The RFCarpet gas cell will be
installed at the exit of the D5 dipole magnet of BigRIPS. The gas catcher contains a large cryogenic He gas cell with a large traveling wave
rf-carpet. It will convert main beams of BigRIPS to low-energy, low-emittance beams without any restrictions on the chemical properties ofthe elements. The PALIS gas cell will be installed in the vicinity of the second focal plane slit of BigRIPS. It will provide parasitic
RI-beams from those ions lost in the slits during other experiments. In this gas catcher, thermalized RI ions quickly become neutral and will
be re-ionized by resonant laser radiations. These gas catchers will be tested off-line in FY2014. The 50 m beam transport line consists offour dipole magnets (SD1 to SD4), two focal plane chambers, 62 electrostatic quadrupole singlets, 11 electrostatic quadrupole quartets(EQQ1 to EQQ11) and 7 beam profile monitors (BPM). SD1 and SD2, located right after the gas catchers will be used for isotope
separation. After eliminating contaminant ions at the focal plane chamber, the low energy beam will be transported by FODO lattice
structure with phase space matching using EQQs. The EQQs have multipole elements made of 16 rods on which various potentials can beapplied to produce 6-pole and 8 pole fields, simultaneously, for compensation of ion optical aberrations. This multipole element can also
produce dipole fields for steering and scanning the beam. The BPM have a classical cross-wire beam monitor as well as a channel
electron multiplier with a pinhole collimator. Combining the scanning capability of the EQQs and the pinhole detector, we can observe abeam profile even for a very low-intensity RI-beams. Off- and on-line commissioning will take place in FY2014 and the low-energy
RI-beams will be provided for users in FY2015.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)(2) Laser spectroscopy of trapped radioactive beryllium isotope ions
(WADA, Michiharu, TAKAMINE, Aiko, SCHURY Peter, SONODA Tetsu, OKADA, Kunihiro, KANAI, Yasuyuki, YOSHIDA, Atsushi,
KUBO, Toshiyuki, WOLLNIK, Hermann, SCHUESSLER, Hans, Shunsuke, KATAYAMA Ichiro)
As a first application of the prototype SLOWRI setup, we applied hyperfine structure spectroscopy to the beryllium isotopes todetermine in particular the anomalous radius of the valence neutron of the neutron halo nucleus 11Be, and to determine the charge radii ofthese beryllium isotopes through laser-laser double resonance spectroscopy of laser-cooled ions. Laser cooling is an essential prerequisite
for these planned experiments. The first laser spectroscopy experiments for beryllium isotopes were performed to measure the resonancefrequencies of 2s 2S1/2 - 2p 2P3/2 transition of 7Be+, 9Be+, 10Be+ and 10Be+ ions and the nuclear charge radii of these isotopes were
determined. The hyperfine structures of 11Be+ and 7Be+ ions using the laser-microwave double resonance spectroscopy were also performed
and the magnetic hyperfine constants of 7Be+ and 11Be+ ions were determined with accuracies of better than10-7.
(3) Development of a multi-reflection TOF mass spectrograph for short-lived nuclei(WADA, Michiharu, SCHURY Peter, ITO, Yuta, ARAI Fumiya, SONODA Tetsu, WOLLNIK, Hermann, MORIMOTO, Koji, KAJI,
Daiya, HABA, Hiromitsu, KOURA, Hiroyuki)
The atomic mass is one of the most important quantities of a nucleus and has been studied in various methods since the early days ofphysics. Among many methods we chose a multi-reflection time-of-flight (MR-TOF) mass spectrometer. Slow RI beams extracted from the
RF ion-guide are bunch injected into the spectrometer with a repetition rate of ~100 Hz. The spectrometer consists of two electrostatic
mirrors between which the ions travel back and forth repeatedly. These mirrors are designed such that energy-isochrononicity in the flighttime is guaranteed during the multiple reflections while the flight time varies with the masses of ions. A mass-resolving power of 170,000
has been obtained with a 2 ms flight time for 40K and 40Ca isobaric doublet. This mass-resolving power should allow us to determine ion
masses with an accuracy of 10-7. An online mass measurement for radioactive lithium isotope has been carried out at the prototype
SLOWRI setup.
The MR-TOF mass spectrograph has been placed under the GARIS-II separator aiming at direct mass measurements of trans-uranium
elements. A small cryogenic gas catcher cell will be placed at the focal plane box of GARIS-II and a bunched low-energy heavy ion beam
can be transported to the trap of MR-TOF. An online commissioning experiment is planned in FY2014.
(4) Development of collinear fast beam apparatus for nuclear charge radii measurements(WADA, Michiharu, SCHUESSLER, Hans, IIMURA, Hideki, SONODA, Tetsu, SCHURY, Peter, TAKAMINE, Aiko, OKADA,
Kunihiro, WOLLNIK, Hermann)
The root-mean-square charge radii of unstable nuclei have been determined exclusively by isotope shift measurements of the opticaltransitions of singly-charged ions or neutral atoms by laser spectroscopy. Many isotopes of alkaline, alkaline-earth, noble-gases and several
other elements have been measured by collinear laser spectroscopy since these ions have all good optical transitions and are available atconventional ISOL facilities. However, isotopes of other elements especially refractory and short-lived ones have not been investigated so
far.
In SLOWRI, isotopes of all atomic elements will be provided as well collimated mono-energetic beams. This should expand the range
of applicable nuclides of laser spectroscopy. In the first years of the RIBF project, Ni and its vicinities, such as Ni, Co, Fe, Cr, Cu, Ga, Ge
are planned to be investigated. They all have possible optical transitions in the ground states of neutral atoms with presently available laser
systems. Some of them have so called recycle transitions which enhance the detection probabilities noticeably. Also the multistep resonanceionization (RIS) method can be applied to the isotopes of Ni as well as those of some other elements. The required minimum intensity forthis method can be as low as 10 atoms per second.
We have built an off-line mass separator and a collinear fast beam apparatus with a large solid-angle fluorescence detector. A 617 nm
transition of the metastable Ar+ ion at 20 keV was measured with both collinear and anti-collinear geometry that allowed us to determine
the absolute resonant frequency of the transition at rest with more than 10-8 accuracy. Such high accuracy measurements for Ti and Ni
isotopes are in progress.
(5) Development of parasitic slow RI-beam production scheme using resonance laser ionization(SONODA Tetsu, IIMURA Hideki, WADA Michiharu, KATAYAMA Ichiou, ADACHI Yoshitaka, NOTO Takuma, TAKATSUKA
Takaaki, TOMITA Hideki, WENDT Klaus, ARAI Fumiya, ITOU Yuta, SCHURY Peter, FUKUDA Naoki, INABE Naohito, KUBO
Toshiyuki, KUSAKA Kensuke, TAKEDA Hiroyuki, SUZUKI H., WAKASUGI Masanori, YOSHIDA Koichi)
More than 99.9% of RI ions produced in projectile fission or fragmentation are simply dumped in the first dipole magnet and the slits.
A new scheme, named PALIS, to rescue such dumped precious RI using a compact gas catcher cell and resonance laser ionization was
proposed as a part of SLOWRI. The thermalized RI ions in a cell filled with Ar gas can be quickly neutralized and transported to the exit of
the cell by gas flow. Irradiation of resonance lasers at the exit ionizes neutral RI atoms efficiently and selectively. The ionized RI ions canbe further selected by a magnetic mass separator and transported to SLOWRI experimental area for various experiment. The resonanceionization scheme itself can also be a useful method to perform hyperfine structure spectroscopy of RI of many elements.
A prototype setup has been tested for resonance ionization scheme of several elements, extraction from the cell, and transport to a highvacuum chamber. An online setup, which will be placed at the second focal plane (F2) of BigRIPS, has been fabricated in FY2013 andcommissioning is scheduled in FY2014.

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESMembers
Team Leader
Michiharu WADA
Research & Technical Scientist
Hideyuki YAMASAWA (concurrent; Infrastructure Management Team)
Nishina Center Research Scientists
Tetsu SONODA

Kensuke KUSAKA (concurrent; BigRIPS Team)

Nishina Center Technical Scientist
Takeshi MAIE (concurrent; Cryogenic Technology Team)
Contract ResearcherPeter Henry SCHURY
Special Postdoctoral Researcher
Yuta ITO (Apr. 1, 2014 –)Research Associate
Yuta ITO (– Mar. 31, 2014)
Temporary Employee
Tadashi FUJINAWA (concurrent, – Mar. 30, 2014)
Part-time Workers
Shigeaki ARAI

Ichiro KATAYAMA

Research Consultant
Hirokane KAWAKAMI
Visiting Researcher
Mikael REPONEN (JSPS, Aug. 4, 2014 –)Visiting Scientists
Hans A SCHUESSLER (Texas A&M Univ.)
Hermann WOLLNIK (Univ. of Giessen)
Aiko TAKAMINE (Aoyama Gakuin Univ.)
Hideki IIMURA (JAEA)

Hideki TOMITA (Nagoya Univ.)
Klaus WENDT (Johannes Gutenberg Univ. Mainz)
Kunihiro OKADA (Sophia Univ.)

Student Trainees
Takuma NOTO (Nagoya Univ.)
Takaaki TAKATSUKA (Nagoya Univ.)
Fumiya ARAI (Univ. of Tsukuba)

Yoshitaka ADACHI (Nagoya Univ.)
Takahide TAKAMATSU (Nagoya Univ.)- 416 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Instrumentation Development Group
Rare RI-ring Team
1. Abstract

Mass measurement is one of the most important contributions to a nuclear property research especially for short-lived unstable nuclei
far from the beta-stability line. In particular, a high-precision mass measurement for nuclei located around the r-process pass (rare-RI) is
required in nucleosynthesis point of view. We chose a method of isochronous mass spectrometry (IMS) to make a measurement timeshorter than 1 ms. Heavy-ion storage ring named “Rare-RI Ring (R3)” has been constructed until end of 2013 and is now under preparation
for the first commissioning experiment. Our target performance in the mass determination is to achieve accuracy of the order of 10-6 (~100keV) even if we get only one event. Since an isochronism in R3 is established over a wide range of the momentum, rare-RIs with a large
momentum spread, p/p=±0.5 %, are acceptable. Another significant feature of the R3 system is an individual injection scheme in which a
produced rare-RI itself triggers the injection kicker. Design study for R3 has been continued from more than ten years ago, and it wasconstructed in 2012 and 2013. In 2014, we demonstrated the R3 performances in test experiments using alpha particle. We are now setting
up and testing all equipments including the power supplies, the control system, the vacuum system, and so on, toward the firstcommissioning planed in 2015.

2. Major Research Subjects

Developments of isochronous storage ring to measure mass of rare RI.

3. Summary of Research Activity

Since the lattice design of R3 is based on the cyclotron motion, it can provide an isochronism in a wide range of the momentum. We
expect a great improvement in mass resolution in IMS as long as the isochronous field is precisely formed in R3. Therefore, IMS using R3
is capable of both a high-precision measurement and a fast measurement. All the devices in R3 was designed under the assumption that anincoming beam has an energy of 200 MeV/u and a charge to mass ratio, m/q, of less than 3. The ring structure was designed with a similar
concept of a separate-sector ring cyclotron. It consists of six sectors and 4.02-m straight sections, and each sector consists of four
rectangular bending magnets. A radially homogeneous magnetic field is produced in the magnet, and a magnetic rigidity is 6.5 Tm at
maximum. Main coils of all the bending magnets are connected in series, and the current of 3000 A is required for rare-RIs, for instance,
78
Ni with the magnetic rigidity of 5.96 Tm. Two magnets at both ends of each sector are additionally equipped with ten trim coils to form
an precise isochronous magnetic field. For p=0 particle, the circumference is 60.35 m and the betatron tunes are x=1.21 and y=0.84 inhorizontal and vertical directions, respectively. The momentum acceptance is p/p=±0.5 %, and the transverse acceptances are
20mmmrad and 10 mmmrad in horizontal and vertical directions, respectively. Although the transverse acceptances of the R3 itself are
actually larger than these values, they are limited by that of the injection beam line. Of special note is that the isochronism is precisely
fulfilled in a wide range of momentum (full width 1 %) due to a cyclotron-motion based lattice design.
Another performance required for R3 is to efficiently seize hold of an opportunity of the measurement for rare-RIs produced
unpredictably. We adopted an individual injection scheme in which the produced rare-RI itself triggers the injection kicker magnets. Fullactivation of the kicker magnetic field have to be completed within the flight time of the rare-RI from an originating point (F3 focal point in
BigRIPS) of the trigger signal to the kicker position in R3. Development of an ultra-fast response kicker system is a key issue forestablishing the individual injection scheme. Performances required for the kicker system are an ultra-fast response, a fast charging, and afull-time charging.
We provided ordinary beam diagnostic devices such as a screen monitor and a beam position monitor based on triangle pickup
electrodes. Although five sets of these monitors distributed along the orbit in R3 are useful in a machine tuning process using ahigh-intensity primary beam. They, however, are incapable for rare-RIs because of the poor sensitivity. Therefore, we inserted
high-sensitive monitors, which are applicable even for a single particle circulation. One of them is a cavity type of Schottky pick-up. A
resonance frequency is designed to be 171 MHz, which corresponds to the harmonic number of 56, and a measured quality factor is about
1900 and shunt impedance is 170 k. We can detect single ion circulation of 78Ni28+ with only a few ms measurement. Another is a timing
monitor, which detects secondary electrons emitted from thin carbon foil placed on the accumulation orbit. The thickness of the foil will be
50 g/cm. The rare-RI with the energy of 200 MeV/u survives only for first 1000 turns because of an energy loss at the foil.
In test experiments using alpha particles emitted from an 241Am source performed in 2014, we succeeded in the individual injection of
the single particle, beam accumulation and the beam extraction. We successfully measured the TOF for 1~10 turns circulation of alphaparticles, and the isochronism in R3 in the order of 10-5 was confirmed. R2 is now under preparation for the first commissioning experimentusing heavy ion beam from accelerators.

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESMembers
Team Leader
Masanori WAKASUGI (concurrent; Group Director, Instrumentations Development Gr.)
Research & Technical Scientists
Yoshiyuki YANAGISAWA (Senior Research Scientist, concurrent; BigRIPS Team)
Tamaki WATANABE (Senior Technical Scientist, concurrent; Beam Dynamics and Diagnostics Team)
Yutaka WATANABE (Senior Technical Scientist, concurrent; RILAC team)
Naohito INABE (Senior Technical Scientist, concurrent; BigRIPS Team)
Hideyuki YAMASAWA (concurrent; Infrastructure Management Team)
Nishina Center Research Scientist
Yoshitaka YAMAGUCHI
Nishina Center Technical Scientists
Takeshi MAIE (concurrent; Cryogenic Technology Team)
Misaki KOMIYAMA (concurrent; Beam Dynamics and Diagnostics Team)
Research Consultant
Akira NODA (– Mar. 31, 2014)
Junior Research Associate
Yasushi ABE (Univ. of Tsukuba)
Temporary Employee
Tadashi FUJINAWA (concurrent, – Mar. 30, 2014)
Visiting Scientist
Daisuke NAGAE (Univ. of Tsukuba)Student Trainees
Yuta SAITO (Univ. of Tsukuba)
Shunsuke OKADA (Univ. of Tsukuba)

Ayano ENOMOTO (Saitama Univ.)- 418 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Instrumentation Development GroupSCRIT Team
1. Abstract

The SCRIT Electron Scattering Facility is now under construction at RIKEN RIBF. This aims at investigation of internal nuclear
structure for short-lived unstable nuclei by means of electron scattering. SCRIT (Self-Confining RI Ion Target) is a novel method to form
internal targets in an electron storage ring. This technique has made electron scattering experiments for unstable nuclei possible.
Construction of the facility has been started in 2009. This facility consists of an electron accelerator (RTM), a SCRIT-equipped electron
storage ring (SR2), an electron-beam-driven RI separator (ERIS), and a detector system for scattered electrons. Operation of accelerators,
RTM and SR2, was started in 2010, performance test of the SCRIT system using stable isotopes, 133Cs and 132Xe, was successfully done in2011 and 2012. Construction of ERIS was started in 2011 and it was commissioned in 2012. The first RI beams from ERIS were suppliedin 2013, and the extraction efficiency was improved by a factor more than ten in 2014. The detector system consisting of a high-resolution
magnetic spectrometer, drift chambers, trigger scintillators, and luminosity monitors were installed. The commissioning using tungsten wire
target resulted the energy resolution of 10-3. We are going to perform the first experiment of electron scattering from unstable nuclei within
a fiscal year 2015.

2. Major Research Subjects

Development of SCRIT electron scattering technique and construction of the SCRIT electron scattering facility.

3. Summary of Research Activity

Development of an electron scattering experimental system for short-lived unstable nuclei using a novel internal target of unstable nuclei(SCRIT).
(Wakasugi, Ohnishi, Kurita, Suda, Tsukada, Tamae, Enokizono, Hori, Hara, Ichikawa)
SCRIT is novel technique to form internal target in an electron storage ring. Positive ions are confined in the electron beam axis bytransverse focusing force given by the circulating electron beam. This is well known "ion trapping" phenomenon. The created ion cloud inwhich RI ions injected from outside are confined works as a target of electron scattering.
In 2010, we successfully commissioned electron accelerators RTM and SR2. Current of electron beams stored in SR2 and its storage
lifetime have been reached to 300 mA and 2 hours, respectively, in the energy range of 150-300 MeV that is required in electron scatteringexperiments. In test experiments of the SCRIT system performed in 2011 and 2012, we used stable isotopes, 133Cs and 132Xe, and revealed
many details of the SCRIT performance. The luminosity of 1027 /(cm2s) was obtained in case of the number of injected ions of 108. The
lifetime of the ion confinement was obtained to be over 1 s. They are performances satisfactory to the electron scattering experiment. In
fact, we succeeded in measurements of angular distributions of scattered electrons from the target ions trapped in the SCRIT device.
Development of ERIS is one of the most important issue in the facility construction. RIs are generated by photo-fission process of 238U,
which is driven by the 150-MeVelectron beams from RTM. ERIS consists of a target ion source including UCx targets and a mass
separation system. ERIS was constructed in 2011 and performances such as the extraction efficiency of 21 % and the mass resolving powerof 1660 were obtained in the commissioning in 2011. We developed production method of UCx targets by ourselves. The first RI
production was succeeded in last year, and 126-132Sn and 138-141Xe isotopes were extracted. The extraction efficiency was improved in 2014,
and the overall efficiencies for 137Xe and 132Sn reached to 14% and 2%, respectively. The yield of 137Xe isotopes exceeded 107 pps with
10-W driver power. A cooler buncher system based on a RFQ linear trap connected to the ERIS beam line is indispensable, because thecontinuous beam from ERIS has to be converted to pulsed beam for ion injection to the SCRIT device. The offline test experiments resulted
more than 10% bunching efficiency for heavy ion beam, and the cooler buncher was installed in the ion beam line from ERIS.
The new detector system consists of a high-resolution magnetic spectrometer, a beam tracking system using drift chambers, trigger
scintillators, and a luminosity monitor. This has a solid angle of 100 msr, energy resolution of 10-3, and the scattering angle coverage of
30-60 degrees. A wide range of momentum transfer, 80-300 MeV/c, is covered by changing the electron beam energy from 150 to 300 MeV.
In last year, the new detector system was successfully commissioned by means of electron scattering from a tungsten wire target.

Members
Team Leader
Masanori WAKASUGI (concurrent; Group Director, Instrumentations Development Gr.)
Research & Technical Scientists
Masamitsu WATANABE (Senior Research Scientist)

Tetsuya OHNISHI (Senior Technical Scientist)

Research Consultants- 419 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

Tadaaki TAMAE
Shin-ichi ICHIKAWA

Masahiro HARA
Takashi EMOTO

Senior Visiting Scientist
Toshitada HORI (Hiroshima Univ.)
Visiting Scientists
Shuo WANG (Tohoku Univ.)
Kyo TSUKADA (Tohoku Univ.)

Toshimi SUDA (Tohoku Univ.)

Part-time Worker
Shunpei YONEYAMA
Student Trainees
Takaya MIYAMOTO (Tohoku Univ.)
Yuto SHIMAKURA (Rikkyo Univ.)
Yuji HARAGUCHI (Nagaoka Univ. of Tech.)

Shunpei YONEYAMA (Tohoku Univ.)
Teruaki TSURU (Tohoku Univ.)
Yosuke MORIYA (Tohoku Univ.)

InternRyota TOBA (Nagaoka Univ. of Tech.)- 420 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Research Instruments Group
1. Abstract

The research instruments group is the driving force at RI Beam Factory (RIBF) for continuous enhancement of activities andcompetitiveness of experimental research. Consisting of four teams, we are in charge of the construction, operation and improvement of thecore research instruments at RIBF, such as BigRIPS in-flight separator, ZeroDegree spectrometer and SAMURAI spectrometer, and therelated infrastructure and equipment. We are also in charge of the production and delivery of RI beams using the BigRIPS separator. The
group also conducts related experimental research as well as R&D studies on the research instruments.

2. Major Research Subjects

Design, construction, operation and improvement of the core research instruments at RIBF and related R&D studies.
studies on exotic nuclei.

3. Summary of Research Activity

Experimental

The current research subjects are summarized as follows:(1) Production and delivery of RI beams and related research(2) Design, construction, operation and improvement of the core research instruments at RIBF and their related infrastructure andequipment(3) R&D studies on the core research instruments and their related equipment at RIBF
(4) Experimental research on exotic nuclei using the core research instruments at RIBF

Members
Group Director
Toshiyuki KUBO
Junior Research Associates
Daichi MURAI (Rikkyo Univ.)

Momo MUKAI (Tsukuba Univ.)

Part-time Worker
Meiko UESAKA
Senior Visiting Scientist
Toshio KOBAYASHI (Tohoku Univ.)- 421 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Research Instruments GroupBigRIPS Team
1. Abstract

This team is in charge of design, construction, development and operation of BigRIPS in-flight separator and its related research
instruments at RI beam factory (RIBF). They are employed not only for the production of RI beams but also the experimental studies using
RI beams.

2. Major Research Subjects

Design, construction, development and operation of BigRIPS in-flight separator, RI-beam transport lines, and their related research
instruments

3. Summary of Research Activity

This team is in charge of design, construction, development and operation of BigRIPS in-flight separator, RI-beam transport lines,
and their related research instruments such as ZeroDegree spectrometer at RI beam factory (RIBF). They are employed not only for the
production of RI beams but also various kinds of experimental studies using RI beams.
The research subjects may be summarized as follows:(1) General studies on RI-beam production using in-flight scheme.
(2) Studies on ion-optics of in-flight separators, including particle identification of RI beams(3) Simulation and optimization of RI-beam production.
(4) Development of beam-line detectors and their data acquisition system.
(5) Experimental studies on production reactions and unstable nuclei.
(6) Experimental studies of the limits of nuclear binding.
(7) Development of superconducting magnets and their helium cryogenic systems.
(8) Development of a high-power production target system.
(9) Development of a high-power beam dump system.
(10) Development of a remote maintenance and remote handling systems.
(11) Operation, maintenance and improvement of BigRIPS separator system, RI-beam transport lines, and their related research
instruments such as ZeroDegree spectrometer and so on.
(12) Experimental research using RI beams.

Members
Team Leader
Koichi YOSHIDA
Research & Technical Scientists
Yoshiyuki YANAGISAWA (Senior Research Scientist)
Naohito INABE (Senior Technical Scientist)
Masao OHTAKE (Senior Technical Scientist)

Kanenobu TANAKA (Technical Scientist, concurrent; Deputy Group
Director, Safety Management Gr.)

Nishina Center Research Scientists
Hiroyuki TAKEDA
Kensuke KUSAKA

Naoki FUKUDA

Contract Researcher
Daisuke KAMEDA (– Aug. 31, 2014)
Postdoctoral Researchers
Hiroshi SUZUKI

Deuk Soon AHN

Part-time Worker
Hidekazu KUMAGAI (– Mar. 31, 2014)
Research Consultant
Hidekazu KUMAGAI (Apr. 1, 2014 –)- 422 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Senior Visiting Scientist
Jerry NOLEN (Argonne National Lab.)
Visiting Scientists
Daisuke KAMEDA (TOSHIBA Corp.)
Michael A. FAMIANO (Western Michigan Univ.)
Daniel Pierre BAZIN (NSCL, MSU)
Oleg Borisovich TARASOV (NSCL, MSU)
Hans GEISSEL (GSI)David Joseph MORRISSEY (NSCL, MSU)
Bradley Marc SHERRILL (NSCL, MSU)
Martin Alfred WINKLER (GSI)

Mauricio PORTILLO (NSCL, MSU)
Dogyun KIM (IBS)
Eunhee KIM (IBS)
Alan Matthew AMTHOR (Bucknell Univ.)
Yutaka MIZOI (Osaka Elec.-Com. Univ.)
Naohito IWASA (Tohoku Univ.)
Sadao MOMOTA (Kochi Univ. of Tech.)Kazuo IEKI (Rikkyo Univ.)

Student Trainees
Yohei OHKODA (Tohoku Univ.)

Kousei ASADA (Tohoku Univ.)- 423 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Research Instruments GroupSAMURAI Team
1. Abstract

In collaboration with research groups in and outside RIKEN, the team designs, develops and constructs the SAMURAI spectrometerand relevant equipment that are and will be used for reaction experiments using RI beams at RI Beam Factory. The SAMURAI
spectrometer consists of a large superconducting dipole magnet and a variety of detectors to measure charged particles and neutrons. Afterthe commissioning experiment in March 2012, the team prepared and conducted, in collaboration with researchers in individual
experimental groups, the first series of experiments with SAMURAI in May 2012. Then, several numbers of experiments were well
performed until now utilizing the property of SAMURAI. The team also provides basis for research activities by, for example, organizing
collaboration workshops by researchers who are interested in studies or plan to perform experiments with the SAMURAI spectrometer.

2. Major Research Subjects

Design, operation, maintenance and improvement of the SAMURAI spectrometer and its related research instruments. Help andmanagement for SAMURAI-based research programs.

3. Summary of Research Activity

The current research subjects are summarized as follows:(1) Operation, maintenance and improvement of a large superconducting dipole magnet that is the main component of the SAMURAI
spectrometer(2) Design, development and construction of various detectors that are used for nuclear reaction experiments using the SAMURAI
spectrometer.
(3) Preparation for planning experiments using SAMURAI spectrometer.
(4) Maintenance and improvement of the SAMURAI beam line.
(5) Formation of a collaboration platform called "SAMURAI collaboration"

Members
Team Leader
Hiromi SATO (− Mar. 31, 2014)
Hideaki OTSU (Apr. 1, 2014 −)Deputy Team Leader
Ken-ichiro YONEDA (− Mar. 31, 2014, concurrent; Team Leader, User Support Office)Research Associate
Yohei SHIMIZU(− Dec. 31, 2014)
Visiting Scientist
Bertis Charles RASCO (Louisiana State Univ.)
Visiting Technician
Nobuyuki CHIGA (Tohoku Univ.)
Student Trainee
Kunihiko HASEGAWA (Tohoku Univ.)- 424 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Research Instruments Group
Computing and Network Team
1. Abstract

This team is in charge of development, management and operation of the computing and network environment, mail and information
servers and data acquisition system and management of the information security of the RIKEN Nishina Center.

2. Major Research Subjects(1) Development, management and operation of the general computing servers(2) Development, management and operation of the mail and information servers(3) Development, management and operation of the data acquisition system(4) Development, management and operation of the network environment(5) Management of the information security

3. Summary of Research Activity

This team is in charge of development, management and operation of the computing and network environment, mail and information
servers and data acquisition system and management of the information security. The details are described elsewhere in this progress report.
(1) Development, management and operation of the general computing servers
We are operating Linux/Unix NIS/NFS cluster system for the data analysis of the experiments and general computing. This cluster
system consists of eight computing servers with 64 CPU cores and totally 200 TB RAID of highly-reliable Fibre-channel interconnection.
Approximately 600 user accounts are registered on this cluster system. We are adopting the latest version of the Scientific Linux (X86_64)
as the primary operating system, which is widely used in the accelerator research facilities, nuclear physics and high-energy physics
communities in the world. We have added a 52 TB RAID for the data analysis in the autumn of 2014 and replaced the ssh login server(RIBF00) in the winter of 2015.
(2) Development, management and operation of the mail and information servers
We are operating RIBF.RIKEN.JP server as a mail/NFS/NIS server. This server is a core server of RIBF Linux cluster system. Postfix
has been used for mail transport software and dovecot has been used for imap and pop services. These software packages enable secure andreliable mail delivery. Sophos Email Security and Control (PMX) installed on the mail front-end servers tags spam mails and isolates
virus-infected mails. The probability to identify the spam is approximately 95-99%. We are operating several information servers such as
Web servers, Integrated Digital Conference (INDICO) server, Wiki servers, Groupware servers, Windows Media and Quick Timestreaming servers, and an anonymous FTP server (FTP.RIKEN.JP). A new Web server has been installed in April 2014 as an official
Web server of RNC to replace the old Web server installed in 2005. A new 72 TB RAID was installed to replace the old RAID to theanonymous FTP server in August 2014.
(3) Development, management and operation of the data acquisition system
We have developed the standard data-acquisition system named as RIBFDAQ. This system can process up to 40 MB/s data. By using
parallel readout from front-end systems, the dead time could be small. To synchronize the independent DAQ systems, the time stamping
system has been developed. The resolution and depth of the time stamp are 10 ns and 48 bit, respectively. This time stamping system isvery useful for beta decay experiments such as EURICA and BRIKEN projects. The current main task is the DAQ coupling, because
detector systems with dedicated DAQ systems are transported to RIBF from foreign facilities. In case of SAMURAI Silicon(NSCL/TUM/WUSTL), the readout system is integrated into RIBFDAQ. The projects of MUST2 (GANIL), MINOS (CEA Saclay), andNeuLAND (GSI) cases, data taken by their DAQ systems are transferred to RIBFDAQ. For SPIRIT (RIKEN/GANIL/CEA Saclay/NSCL),RIBFDAQ data are sent to GET system that is a large-scale signal processing system for the time projection chamber. These cases, data aremerged in online. On the other hand, EURICA (GSI) and BRIKEN (GSI/Univ. Liverpool/IFIC) projects, we adopt the time stamping
system to use individual trigger for each detector system. In this case, data are merged in offline. In addition to the development DAQ
system, we are developing intelligent circuits based on FPGA. Mountable Controller (MOCO) is a very fast readout controller for VME
modules. General Trigger Operator (GTO) is an intelligent triggering NIM module. Functions of “common trigger management”, “gate anddelay generator”, “scaler” are successfully implemented on GTO.
(4) Development, management and operation of the network environment
We have been managing the network environment collaborating with Advanced Center for Computing and Communications (ACCC).
All the Ethernet ports of the information wall sockets are capable of the Gigabit Ethernet connection (10/100/1000BT). In addition, a 10
Gbps network port has been introduced to the RIBF Experimental area in for the high speed data transfer of RIBF experiment to ACCC innear future. Approximately 60 units of wireless LAN access points have been installed to cover the almost entire area of Nishina Center.
(5) Management of the information security
It is essential to take proper information security measures for information assets.

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Ⅵ. RNC ACTIVITIESWe are managing the information security of Nishina Center collaborating with ACCC.

Members
Team Leader
Takashi ICHIHARA (concurrent; Vice Chief Scientist, RI Physics Lab.)
Research & Technical Scientist
Yasushi WATANABE (concurrent; Senior Research Scientist, Radiation Lab.)
Nishina Center Research Scientist
Hidetada BABA
Student Trainee
Ryousuke TANUMA (Rikkyo Univ.)- 426 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Research Instruments Group
Detector Team
1. Abstract

This team is in charge of development, fabrication, and operation of various detectors used for nuclear physics experiments at RIBF.
Our current main mission is maintenance and improvement of beam-line detectors which are used at BigRIPS separator and its succeeding
beam lines for beam diagnosis and particle identification of RI beams. We are also engaged in research and development of new detectorsthat can be used for higher-intensity RI beams.

2. Major Research Subjects

Development, fabrication, and operation of various detectors for nuclear physics experiments, including beam-line detectors which areused for the production and delivery of RI beams (beam diagnosis and particle identification).

3. Summary of Research Activity

The current research subjects are summarized as follows:(1) Maintenance and improvement of the beam-line detectors which are used at BigRIPS separator and its succeeding beam lines.
(2) Development of new beam-line detectors with radiation hardness and tolerance for higher counting rates(3) Development of a high dynamic range preamplifier for silicon strip detectors

Members
Team Leader
Toshiyuki KUBO (concurrent; Group Director, Research Instruments Gr., – Mar. 31, 2014)
Hiromi SATO (Apr. 1, 2014 –)Special Postdoctoral Researcher
Yuki SATO
Research Consultant
Hiroyuki MURAKAMI
Visiting Scientist
Kohei FUJIWARA (Tokyo Met. Ind. Tech. Res. Inst.)- 427 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Accelerator Applications Research Group
1. Abstract

This group promotes various applications of ion beams from RI Beam Factory (RIBF). Radiation Biology Team studies various
biological effects of fast heavy ions and develops new technology to breed plants and microbials by heavy-ion irradiations. RI Applications
Team studies production and application of radioisotopes for various research fields, development of trace element analysis and its
application, and development of chemical materials for ECR ion sources of RIBF accelerators.

2. Major Research Subjects

Research and development in biology, chemistry and materials science utilizing heavy-ion beams from RI Beam Factory.

3. Summary of Research Activity
(1)
(2)
(3)
(4)
(5)

Biological effects of fast heavy ions.
Development of heavy-ion breeding.
Production and application of radioisotopes.
Developments of trace elements analyses.
Development of chemical materials for ECR ion sources of RIBF accelerators.

Members
Group Director
Tomoko ABE- 428 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Accelerator Applications Research GroupIon Beam Breeding Team
1. Abstract

Ion beam breeding team studies various biological effects of fast heavy ions. It also develops new technique to breed plants byheavy-ion irradiations. Fast heavy ions can produce dense and localized ionizations in matters along their tracks, in contrast to photons (Xrays and gamma rays) which produce randomly distributed isolated ionizations. These localized and dense ionization can cause
double-strand breaks of DNA which are not easily repaired and result in mutation more effectively than single-strand breaks. A uniquefeature of our experimental facility at the RIKEN Ring Cyclotron (RRC) is that we can irradiate living tissues in atmosphere since thedelivered heavy-ion beams have energies high enough to penetrate deep in matter. This team utilizes a dedicated beam line (E5B) of the
RRC to irradiate microbes, plants and animals with beams ranging from carbon to iron. Its research subjects cover physiological study of
DNA repair, genome analyses of mutation, and development of mutation breeding of plants by heavy-ion irradiation. Some new cultivars
have already been brought to the market.

2. Major Research Subjects
(1)
(2)
(3)

Study on the biological effects by heavy-ion irradiation
Studies on ion-beam breeding and genome analysis
Innovative application of heavy-ion beams

3. Summary of Research Activity

We study biological effects of fast heavy ions from the RIKEN Ring Cyclotron using 135A MeV C, N, Ne ions, 95A MeV Ar ions and
90A MeV Fe ions. We also develop breeding technology of microbes and plants. Main subjects are:(1) Study on the biological effects by heavy-ion irradiation
Heavy-ion beam deposits a concentrated amount of dose at just before stop with severely changing the LET. The peak of LET isachieved at the stopping point and known at the Bragg peak (BP). It is well know to be good for cancer therapy to adjust the BP to target
malignant cells. On the other hand, a uniform dose distribution is a key to the systematic study, and thus to the improvement of the mutation
efficiency. Therefore plants and microbes are treated using ions with stable LET. We investigated the effect of LET ranging from 22.5 to
640 keV/μm, on mutation induction using the model plant Arabidopsis thaliana. The most effective LET (LETmax) was 30.0 keV/μm. In
the case of microbe (Mesorhizobium lothi), the results showed a higher incidence of deletion mutations for Fe ions at 640 KeV/μm than for
C ions at 23-40 keV/μm. Thus, the LET of ion beams seems to be an important factor affecting mutagenesis.
(2) Study on ion-beam breeding and genome analysis
In contrast to X rays and gamma rays, fast heavy ions are found to be useful for plant breeding since they only cause localized damage
on DNA and can induce mutations more effectively with lower dosage. Our team utilizes beams of fast heavy ions from the RRC todevelop heavy-ion breeding techniques. LETmax is effective for breeding because of its very high mutation frequency. Since most
mutations are small deletions, these are sufficient to disrupt a single gene. Thus, irradiation can efficiently generate knockout mutants of atarget gene, and can be applied to reverse genetics. Higher LET (> 290 keV/μm) was shown to efficiently generate large deletions ranging
from several to several tens of kbp. Many genes in the Arabidopsis genome (> 10%) are composed of tandem duplicated genes that sharefunctions. Previous studies demonstrated that large deletions were required to knockout tandem arrayed genes, and the appropriate deletion
size was estimated to be approximately 5–10 kbp, based on gene density in Arabidopsis. No method is currently available to efficiently
generate deletion mutants of this size. As such, higher LET irradiation is promising as a new mutagen suitable for the functional analysis oftandem duplicated genes.
(3) Innovative application of heavy-ion beams
We have formed a consortium for ion-beam breeding. It consisted of 24 groups in 1999, in 2014, it consisted of 168 groups fromJapan and 18 from overseas. Breeding was performed previously using mainly flowers and ornamental plants. We have recently put a newJapanese barnyard millet cultivar with low amylose content and short culm, ‘Nebarikko No. 2’ on the market. Beneficial variants have beengrown for various plant species, such as high yield rice, semi-dwarf early rice, semi-dwarf buckwheat, semi-dwarf barley, hypoallergenic
peanut, spineless oranges, non-flowering Eucalyptus and lipids-hyperaccumulating unicellular alga. We also successfully isolated 4
salt-resistant lines of rice from 325 progeny lines. We collaborate with Miyagi prefecture and Tohoku University to breed salt-resistantlines in the more delicious commercial rice varieties, ‘Hitomebore’ and ‘Manamusume’, that will grow normally and retain their good taste
in saline paddy fields affected by the recent tsunami. The target of heavy-ion breeding is extended from flowers to crops like grains so that
it will contribute to solve the global problems of food and environment.

Members
Team Leader
Tomoko ABE (concurrent: Group Director, Accelerator Applications Research Gr.)- 429 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

Research & Technical Scientist
Kazuhide TSUNEIZUMI (Senior Research Scientist)
Masako IZUMI (Senior Research Scientist)
Tokihiro IKEDA (Senior Research Scientist)
Teruyo TSUKADA (Senior Research Scientist)

Katsunori ICHINOSE (Senior Technical Scientist)
Hiroshi ABE (Senior Technical Scientist)
Ryouhei MORITA (Technical Scientist)

Contract Researchers
Hiroyuki ICHIDA (Feb.,1., 2015)
Yusuke KAZAMA

Tomonari HIRANO (– Nov. 30, 2014)

Postdoctoral Researcher
Koutaro ISHIITechnical Staff I
Yoriko HAYASHI
Sachiko KOGURE (– Mar. 31, 2014)

Motoko MURAKAMI (Apr. 1, 2014 –)Technical Staff II
Sumie OHBU
Foreign Postdoctoral Researcher
Reka BERECZKY
Research Consultants
Tadashi SATO

Masahiro MII

Part-time Workers
Hideo TOKAIRIN
Yuki SHIRAKAWA
Sachiko KOGURE (Apr. 15, 2014 –)Taeko WAKANA
Sayaka NIWA (May 7, 2-14 – Nov. 30, 2014)

Mieko YAMADA
Satoko YASUDAHaruka WATANABE (Aug. 11, 2014 – Sep. 12, 2014)
Anju MATSNAGA (Aug. 4, 2014 – Sep. 30, 2014)
Honami OOHASHI (– Sep. 5, 2014)

Visiting Scientist
Makoto FUJIWARA (Univ. of Tokyo)
Masao WATANABE (Tohoku Univ.)
Hisashi TSUJIMOTO (Tottori Univ.)
Yutaka MIYAZAWA (Tohoku Univ.)
Toshinari GODO (Botanic Gardens Toyama)
Masanori TOMITA (CRIEPI)
Toshikazu MORISHITA (Nat’l. Inst. Agric. Res.)
Hiroyuki ICHIDA (Stanford Univ.)
Koji MURAI (Fukui Pref. Univ.)
Hinako TAKEHISA (Nat’l. Inst. Agric. Sci.)
Akiko HOKURA (Tokyo Denki Univ.)

Norihiro OHTSUBO (Natl. Inst. Floricult. Sci.)
Eitaro FUKATSU (Forestry and Forest Products Res. Inst.)
Tomonari HIRANO (Univ. of Miyazaki)
Yoichi SATO (Riken Food Co., Ltd.)Ali FERJANI (Tokyo Gakugei Univ.)
In-Ja SONG (Jeju Nat’l University)
Katsutomo SASAKI (Nat’l Agric. and Food Res. Org.)
Kunio SUZUKI (Technoflora, Co., Ltd.)
Kazumitsu MIYOSHI (Akita Pref. Univ.)
Makoto UBUKATA (Hokkaido Univ.)
Akihiro IWASE (Osaka Pref. Univ.)

Visiting Technicians
Takuji YOSHIDA (Takii Seed Co., Ltd.)
Tomojirou KOIDE (Riken Vitamin Co., Ltd.)

Yutaka ITOH (Riken Food Co., Ltd.)

Research Fellows
Naoji WAKITA (Wadomari Cho Agr. Exp. Station)
Kyousuke NIWA (Hyogo Pref. Res. Inst.)
Miyuki NISHI (Saga Agric. Experiment Station)
Tadahito OOTUBO (Wadomari Cho Agr. Exp. Station)

Shunsuke IMANISHI (Natl. Inst.Veg. and Tea Sci.)
Takeya ICHIKI (Wadomari Cho)
Tomihiro TAKESHITA (Wadomari Cho)
Humio SUGAMURA (Wadomari Cho)

Student Trainees
Fumitaka YAMAGISHI (Tokyo Denki Univ.)
Fumitaka TAMEZAWA (Tokyo Denki Univ.)
Kentaro FUJITA (Tokyo Denki Univ.)
Kana MIYOSHI (Tokyo Univ. of Sci.)
Takuto TAKAHASHI (Tokyo Denki Univ.)
Hiroki KAWAMOTO (Univ. of Tokyo)

Megumi UTSUGI (Toho Univ.)
Yu IMAMURA (Tokyo Denki Univ.)
Hiroki ISHIKAWA (Sophia Univ.)
Mao SUZUKI (Sophia Univ.)
Shun SASAKI (Sophia Univ.)- 430 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
Accelerator Applications Research GroupRI Applications Team
1. Abstract

The RI Applications Team develops production technologies of radioisotopes (RIs) at RIKEN RI Beam Factory (RIBF) for application
studies in the fields of physics, chemistry, biology, medicine, pharmaceutical and environmental sciences. We use the RIs mainly for
nuclear and radiochemical studies such as RI production and superheavy element chemistry. The purified RIs such as 65Zn and 109Cd aredelivered to universities and institutes through Japan Radioisotope Association. We also develop new technologies of mass spectrometry forthe trace-element analyses using accelerator technology and apply them to the research fields such as cosmochemistry, environmental
science, archaeology and so on. We also develop chemical materials for ECR ion sources of the RIBF accelerators.

2. Major Research Subjects
(1)
(2)
(3)

(4)

Research and development of RI production technology at RIBF
RI application researches
Development of trace element and isotope analyses using accelerator techniques and its applications to geoscience andenvironmental science
Development of chemical materials for ECR ion sources of RIBF accelerators

3. Summary of Research Activity

RI Applications Team utilizes RIBF heavy-ion accelerators for following research subjects:(1) Research and development of RI production technology at RIBF and RI application studies
Due to its high sensitivity, the radioactive tracer technique has been successfully applied for investigations of the behavior of elementsin the fields of chemistry, biology, medicine, engineering, and environmental sciences. We have been developing production technologies
of useful radiotracers at RIBF and conducted their application studies in collaboration with many researchers in various fields. With
14-MeV proton, 24-MeV deuteron, and 50-MeV alpha beams from the AVF cyclotron, we presently produce about 30 radiotracers from
7Be to 206Bi. Among them, 65Zn, 85Sr, 88Y, and 109Cd are delivered to Japan Radioisotope Association for fee-based distribution to thegeneral public in Japan. On the other hand, radionuclides of a large number of elements are simultaneously produced from metallic targets
such as natTi, natAg, natHf, and 197Au irradiated with a 135-MeV nucl.–1 14N beam from the RIKEN Ring Cyclotron. These multitracers arealso supplied to universities and institutes as collaborative researches.
In 2014, we developed production technologies of radioisotopes such as 28Mg, 48,51Cr, 67Cu, 95mTc, 183,184m,184gRe, and 191Pt which werestrongly demanded but lack supply sources in Japan. We also investigated the excitation functions for the natTi(α,x), natGe(α,x), natZr(α,x),natMo(d,x), natCd(α,x), 116Cd(α,x), natSm(d,x), natHo(α,x), natW(d,x), and natPt(d,x) reactions to produce useful RIs. We produced 65Zn, 109Cd,
and 88Y for our scientific researches on a regular schedule and supplied the surpluses through Japan Radioisotope Association to the generalpublic. In 2014, we have accepted 5 orders of 65Zn with a total activity of 33 MBq, 3 orders of 109Cd with 21 MBq, and 2 orders of 88Y with
2 MBq.
(2) Superheavy element chemistry
Chemical characterization of newly-discovered superheavy elements (SHEs, atomic numbers Z ≥ 104) is an extremely interesting andchallenging subject in modern nuclear and radiochemistry. We are developing SHE production systems as well as rapid single-atomchemistry apparatuses at RIBF. Using heavy-ion beams from RILAC and AVF, long-lived 261Rf (Z = 104), 262Db (Z = 105), and 265Sg (Z =106) are produced in the 248Cm(18O,5n)261Rf, 248Cm(19F,5n)262Db, and 248Cm(22Ne,5n)265Sg reactions, respectively, and their chemical
properties are investigated.
We have been developing a gas-jet transport system at the focal plane of the gas-filled recoil ion separator GARIS at RILAC. Thissystem is a promising approach for exploring new frontiers in SHE chemistry: (i) the background radioactivities of unwanted reaction
products are strongly suppressed, (ii) the intense beam is absent in the gas-jet chamber and hence high gas-jet efficiency is achieved, and(iii) the beam-free condition also allows for investigations of new chemical systems. In 2014, the isotope of element 107 266Bh was
produced in the 248Cm(23Na,5n)266Bh reaction, and its decay properties were investigated using the rotating wheel apparatus MANON for
α/SF spectrometry. Toward the SHE chemistry behind GARIS, we developed a gas-chromatograph apparatus directly coupled to GARIS,
which enabled in-situ complexation and gas-chromatographic separation of a large variety of volatile compounds of SHEs. Toward aqueous
chemistry of the heaviest elements such as Sg and Bh, we also started to develop a new rapid chemistry apparatus which consisted of acontinuous dissolution apparatus Membrane DeGasser (MDG), a flow liquid-liquid extraction apparatus, and a flow liquid scintillation
detector for α/SF-spectrometry.
At the AVF cyclotron, the distribution coefficients (Kd) of 261Rf on the Aliquat 336 resin were measured in HCl with the AutoMated
Batch-type solid-liquid Extraction apparatus for Repetitive experiments of transactinides (AMBER) in collaboration with Osaka Univ. The
extraction behavior of 89mZr and 173Hf in the Aliquat 336/HCl system was investigated for Rf chemistry with the flow-type liquid-liquid
extraction apparatus. The reversed-phase TTA extraction chromatography of 261Rf and its homologues 85Zr and 169Hf was conducted in
HF/HNO3 using the Automated Rapid Chemistry Apparatus (ARCA) in collaboration with Kanazawa Univ., Niigata Univ., and JAEA. The
reversed-phase extraction chromatography of 90gNb and 178aTa in Aliquat 336/HF and the anion-exchange chromatography of 90gNb and
178aTa in HF/HNO were also conducted with ARCA for chemical studies of Db. For Sg chemistry, we investigated the extraction behavior
3of 93mMo and 177,179mW in H2SO4 and H2C2O4 solutions with Aliquat 336.

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Ⅵ. RNC ACTIVITIES(3) Development of trace element analysis using accelerator techniques and its application to geoscience and environmental science
We developed new mass spectrometry technologies for trace element analyses as an application of accelerator technology to various
fields such as cosmochemistry, environmental science, and archaeology. ECRIS-AMS is a new type of accelerator mass spectrometry at
RILAC equipped with an ECR ion source. This system is available for measuring trace elements (10–14–10–15 level) and is expected to be
especially effective for measurements of low-electron-affinity elements such as 26Al, 41Ca, and 53Mn. In 2014, we have renovated thedetection system and examined the sensitivity and mass resolution power. We also attempted to develop another technology by customizing
a mass spectrometer equipped with a stand-alone ECR ion source for analyses of elemental and isotopic abundances. Especially, we
equipped laser-ablation system with ion source to achieve high-resolution analysis. Furthermore, we analyzed sulfur and lead isotope ratios
for cinnabar samples from ancient tombs in Japan to elucidate the origin of cinnabar. In 2014, we showed that the lead isotopes in cinnabar
ore exhibited clear local characteristics and the origin of the cinnabar ore could be distinguished from the lead isotope compositions.
(4) Development of chemical materials for ECR ion sources of RIBF
In 2014, we investigated production methods of 238U(C8H8)2 and metallic 50Ti powder for the ECR ion source of RIBF. We also
prepared metallic 238U and 238UO2 on a regular schedule.

Members
Team Leader
Hiromitsu HABA
Research & Technical Scientist
Kazuya TAKAHASHI (Senior Research Scientist)
Postdoctoral Researchers
Minghui HUANG (– Mar. 31, 2014)

Yukiko KOMORITechnical Staff I
Jumpei KANAYA
Research Consultant
Seiichi SHIBATA
Junior Research Associate
Masashi MURAKAMI (Niigata Univ.)
Part-time Workers
Michiko KITAGAWA

Yu Vin SAHOO

Visiting Scientists
Akihiko YOKOYAMA (Kanazawa Univ.)
Kazuhiko AKIYAMA (Tokyo Met. Univ. )Kazuhiro OOE (Niigata Univ.)
Hidetoshi KIKUNAGA (Tohoku Univ.)
Masayoshi TODA (Tokyo Univ. Marine Sci. and Tech.)Mayeen Uddin KHANDAKER (Univ. Malaya)
Takahiro YAMADA (Japan Rad. Assoc.)
Miho TAKAHASHI (Tokyo Univ. Marine Sci. and Tech.)
Hiroshi SHIMIZU (Rissho Univ.)

Visiting Technicians
Yuichiro WAKITANI (Japan Rad. Assoc.)

Shinya YANOU (Japan Rad. Assoc.)

Student Trainees
Junichi HIRATA (Tokyo Univ. Marine Sci. and Tech.)Yuuki SHIGEYOSHI (Kanazawa Univ.)
Yuuta KITAYAMA (Kanazawa Univ.)
Hajime KIMURA (Kanazawa Univ.)
Eita MAEDA (Kanazawa Univ.)
Keigo TOYOMURA (Osaka Univ.)
Kouhei NAKAMURA (Osaka Univ.)
Yuri OBI (Tokyo Univ. Marine Sci. and Tech.)
Yoshiki FUKUDA (Kanazawa Univ.)
Yudai SHIGEKAWA (Osaka Univ.)
Shingo UENO (Kanazawa Univ.)
Kazunori HAYASHI (Kanazawa Univ.)
Takumi TANIGUCHI (Kanazawa Univ.)
Naoya GOTO (Niigata Univ.)

Takumi KOYAMA (Niigata Univ.)
Shohei TSUTO (Niigata Univ.)
Ryuji AONO (Niigata Univ.)
Daisuke SATO (Niigata Univ.)
Akira TANAKA (Niigata Univ.)
Tetuya NAGAOKA (Niigata Univ.)
Iori CHIYONISHIO (Kanazawa Univ.)
Ahmed USMAN (Univ. of Malaya)
Kento MURAKAMI (Kanazawa Univ.)
Teruyoshi FUJISAWA (Kanazawa Univ.)
Yukari YATSU (Kanazawa Univ.)
Yuki YASUDA (Osaka Univ.)
Yoshihiko HAYASHI (Osaka Univ.)
Risa MOTOYAMA (Niigata Univ.)- 432 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
User Liaison and Industrial Cooperation Group
1. Abstract

The essential mission of the “User Liaison and Industrial Cooperation (ULIC) Group” is to maximize the research activities of RIBF
by attracting users in various fields with a wide scope.
The ULIC Group consists of two teams.
The User Support Team provides various supports to visiting RIBF users through the User’s Office. The Industrial Cooperation Teamsupports potential users in industries who use the beams for application purposes or for accelerator related technologies other than basic
research. Production of various radioisotopes by the AVF cyclotron is also one of the important mission. The produced radioisotopes are
distributed to researchers in Japan for a charge through the Japan Radioisotope Association.
In addition the ULIC Group takes care of laboratory tours for RIBF visitors from public. The numbers of visitors amounts to 2,300 per
year.

Members
Group Director
Hideyuki SAKAI
Deputy Group Director
Hideki UENO (concurrent: Chief Scientist, Nuclear Spectroscopy Lab.)
Research & Technical Scientist
Mieko KOGURE (Technical Assistant, – Mar. 31, 2014)
Special Temporary Employee
Tadashi KAMBARA
Senior Visiting Scientists
Ikuko HAMAMOTO (Lund Univ.)

Munetake ICHIMURA (Univ. of Tokyo)

Assistants
Katsura IWAI
Tomoko IWANAMI

Noriko KIYAMA- 433 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
User Liaison and Industrial Cooperation Group
User Support Office
1. Abstract

To enhance synergetic common use of the world-class accelerator facility, the Radioisotope Beam Factory (RIBF), it is necessary to
promote a broad range of applications and to maximize the facility’s importance. The facilitation and promotion of the RIBF are importantmissions charged to the team. Important operational activities of the team include: i) the organization of international Program Advisory
Committee (PAC) meetings to review experimental proposals submitted by RIBF users, ii) RIBF beam-time operation management, andiii) promotion of facility use by hosting outside users through the RIBF Independent Users program, which is a new-user registration
program begun in FY2010 at the RIKEN Nishina Center (RNC) to enhance the synergetic common use of the RIBF. The team opened the
RIBF Users Office in the RIBF building in 2010, which is the main point of contact for Independent Users and provides a wide range ofservices and information.

2. Major Research Subjects(1)(2)

Facilitation of the use of the RIBF
Promotion of the RIBF to interested researchers

3. Summary of Research Activity(1) Facilitation of the use of the RIBF
The RIBF Users Office, formed by the team in 2010, is a point of contact for user registration through the RIBF Independent User
program. This activity includes:
registration of users as RIBF Independent Users,
registration of radiation workers at the RIKEN Wako Institute,provision of an RIBF User Card (a regular entry permit) and an optically stimulated luminescence dosimeter for each RIBF
Independent User, andprovision of safety training for new registrants regarding working around radiation, accelerator use at the RIBF facility, andinformation security, which must be completed before they begin RIBF research.
The RIBF Users Office is also a point of contact for users regarding RIBF beam-time-related paperwork, which includes:contact for beam-time scheduling and safety review of experiments by the In-House Safety Committee,
preparation of annual Accelerator Progress Reports, andmaintaining the above information in a beam-time record database.
In addition, the RIBF Users Office assists RIBF Independent Users with matters related to their visit, such as invitation procedures,visa applications, and the reservation of on-campus accommodation.
(2) Promotion of the RIBF to interested researchers
The team has organized an international PAC for RIBF experiments; it consists of leading scientists worldwide and reviews
proposals in the field of nuclear physics (NP) purely on the basis of their scientific merit and feasibility. The team also assists
another PAC meeting for material and life sciences (ML) organized by the RNC Advanced Meson Laboratory. The NP and ML PAC
meetings are organized twice a year.
The team coordinates beam times for PAC-approved experiments and other development activities. It manages the operatingschedule of the RIBF accelerator complex according to the decisions arrived at by the RIBF Machine Time Committee.
To promote research activities at RIBF, proposals for User Liaison and Industrial Cooperation Group symposia/mini-workshops are
solicited broadly both inside and outside of the RNC. The RIBF Users Office assists in the related paperwork.
The team is the point of contact for the RIBF users’ association. It arranges meetings at RNC headquarters for the RIBF User
Executive Committee of the users’ association.
The Team conducts publicity activities, such as arranging for RIBF tours, development and improvement of the RNC official web
site, and delivery of RNC news via email and the web.

Members
Team Leader
Ken-ichiro YONEDA
Deputy Team Leader
Yasushi WATANABE (concurrent: Senior Research Scientist, Radiation Lab.)
Technical Staff I
Narumasa MIYAUCHI- 434 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

RIBF Research Division
User Liaison and Industrial Cooperation Group
Industrial Cooperation Team
1. Abstract

Industrial cooperation team handles non-academic activities at RIBF corresponding to industries and to general public.

2. Major Research Subjects
(1)
(2)

(3)

Fee-based distribution of radioisotopes produced at RIKEN AVF Cyclotron
Support of industrial application using the RIBF accelerator beam and its related technologies including novel industrial
applications.
Development of real-time wear diagnostics of industrial material using RI beams

3. Summary of Research Activity(1) Fee-based distribution of radioisotopes
This team handles fee-based distribution of radioisotopes Zn-65, Y-88 and Cd-109 from 2007, which are produced by the RI
application team at the AVF cyclotron, to nonaffiliated users under a Material Transfer Agreement between Japan Radioisotope Association
and RIKEN. In 2014, we delivered 3 shipments of Cd-109 with a total activity of 22 MBq, 7 shipments of Zn-65 with a total activity of 44
MBq and one shipment of Y-88 with an activity of 1 MBq. The final recipients of the RIs were five universities, one research institutes andtwo hospitals.
(2) Support of Industrial application using RIBF
In November 2009, RNC started a new project “Promotion of applications of high-energy heavy ions and RI beams” as a grant-in-aid
program of MEXT “Sharing Advanced Facilities for Common Use Program”. In this project, RNC opens the old part of the RIBF facility,
which includes the AVF cyclotron, RILAC, RIKEN Ring Cyclotron and experimental instruments like RIPS, to non-academic proposals
from users including private companies. This MEXT program was terminated in September 2010, but RNC succeed and promote thisfacility sharing program after that. The proposals are reviewed by a program advisory committee, industrial PAC. The proposals whichhave been approved by the industrial PAC are allocated with beam times and the users pay RIKEN the beam time fee. The intellectual
properties obtained by the use of RIBF belong to the users. In order to encourage the use of RIBF by those who are not familiar withutilization of ion beams, the first two beam times of each proposal can be assigned to trial uses which are free of beam time fee.
The fourth industrial PAC meeting held in August 2014 reviewed two fee-based proposals from private companies and approved them.
The first proposal of fee-based utilization was performed in October with a 70-MeV/A 84Kr beam at the E5A beamline of the RIKEN Ring
Cyclotron.
(3) Development of real-time wear diagnostics using RI beams
We are promoting a method for real-time wear diagnostics of industrial material using RI beams as tracers. For that purpose, very
intense RI beams of 7Be (T1/2=52 days) at 4.1 MeV/u and 22Na (T1/2=2.6 years) at 3.7 MeV/u were produced via the (p,n) reaction at the
CRIB separator using beams from the AVF cyclotron. As we can provide RI beams of different nuclides and control the implantation depth,
we have developed a novel method of wear diagnostics.
Under a collaborative research agreement entitled “Development and application of wear diagnosis method with RI beams" between
RIKEN, University of Tokyo and two private companies, we had two beam-times in February and in March 2014, at E7A beam-line of the
AVF cyclotron. Beams of RI nuclei 7Be and 22Na were provided by CRIB and implanted near surface of metallic machine parts, whose
wear-loss rate was evaluated through measurements of the radio-activities.
We are also developing a new method to determine the spatial distribution of positron-emitting RIs on periodically-moving objects in aclosed system, which can be used for real-time evaluation of wear loss in a running machine. This is based on the same principle as the
medical PET systems but is simpler and less expensive.

Members
Team Leader
Atsushi YOSHIDA
Research & Technical Scientist
Hiroshige TAKEICHI (Senior Research Scientist, –Jun. 30, 2014)
Visiting Technicians
Shuhei TATEMICHI (Fuji Electric Systems)

Masanori INOUE (Fuji Electric Systems)- 435 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESRIBF Research Division
Safety Management Group
1. Abstract

The RIKEN Nishina Center for Accelerator-Based Science possesses one of the largest accelerator facilities in the world, which
consists of two heavy-ion linear accelerators and five cyclotrons. This is the only site in Japan where uranium ions are accelerated. The
center also has electron accelerators of microtron and synchrotron storage ring. Our function is to keep the radiation level in and around thefacility below the allowable limit and to keep the exposure of workers as low as reasonably achievable. We are also involved in the safety
management of the Radioisotope Center, where many types of experiments are performed with sealed and unsealed radioisotopes.

2. Major Research Subjects
(1)
(2)
(3)

Safety management at radiation facilities of Nishina Center for Accelerator-Based Science
Safety management at Radioisotope Center
Radiation shielding design and development of accelerator safety systems

3. Summary of Research Activity

Our most important task is to keep the personnel exposure as low as reasonably achievable, and to prevent an accident. Therefore, wedaily patrol the facility, measure the ambient dose rates, maintain the survey meters, shield doors and facilities of exhaust air andwastewater, replenish the protective supplies, and manage the radioactive waste. Advice, supervision and assistance at major accelerator
maintenance works are also our task.
We revised the safety interlock system of RIBF building to prevent excess exposures due to unexpected high-intensity beam transport
through the BigRIPS. When the primary beam is transported through BigRIPS, rooms adjacent to and in the vicinity of the room where thebeam is transported are evacuated. If the magnetic fields of the two dipole magnets before and after the BigRIPS target position were setvery closely, the interlock system recognizes the primary beam is transported through the BigRIPS. The primary beam mode can be also set
manually. In the primary beam mode, some attenuators of accelerators cannot be taken out not to deliver a high-intensity beam to BigRIPS
by human error.

Members
Group Director
Yoshitomo UWAMINO
Deputy Group Director
Kanenobu TANAKA (Apr. 1, 2014 –)Nishina Center Technical Scientists
Rieko HIGURASHI
Hisao SAKAMOTO

Takeshi MAIE (concurrent; Cryogenic Technology Team)Technical Staff I
Atsuko AKASHIO

Tomoyuki DANTSUKA (concurrent; Cryogenic Technology Team)

Research Consultant
Masaharu OKANO (Japan Radiation Res. Soc.)
Visiting Scientists
Hee Seock LEE (POSTECH)
Joo-Hee OH (POSTECH))
Nam-Suk JUNG (POSTECH)

Takashi NAKAMURA (Shimizu Corp.)
Noriaki NAKAO (Shimizu Corp.)
Koji OHISHI (Shimizu Corp.)

Assigned Employee
Hiroki MUKAI
Temporary Staffing
Ryuji SUZUKI

Hiroyuki FUKUDA

Part-time Workers
Hiroshi KATO
Satomi IIZUKA
Kimie IGARASHI
Hiroko AISO

Naoko USUDATE
Shin FUJITA
Kazushiro NAKANOAssistant
Tomomi OKAYASU- 436 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Partner Institution

The Nishina Center established the research partnership system in 2008. This system permits an external institute to develop its own
projects at the RIKEN Wako campus in equal partnership with the Nishina Center. At present, three institutes, Center for Nuclear Study of
the University of Tokyo (CNS), Institute of Particle and Nuclear Studies of KEK (KEK), and Department of Physics, Niigata University(Niigata) are conducting research activities under the research partnership system.
CNS and the Nishina Center signed the partnership agreement in 2008. Until then, CNS had collaborated in joint programs withRIKEN under the “Research Collaboration Agreement on Heavy Ion Physics” (collaboration agreement) signed in 1998. The partnershipagreement redefines procedures related to the joint programs while keeping the spirit of the collaboration agreement. The joint programs
include experimental nuclear physics activities using CRIB, SHARAQ, GRAPE at RIBF, theoretical nuclear physics activities with
ALPHLEET, accelerator development, and activities at RHIC PHENIX.
The partnership agreement with the Niigata University was signed in 2010. The activity includes theoretical and experimental nuclear
physics, and nuclear chemistry.
KEK started low-energy nuclear physics activity at RIBF in 2011 under the research partnership system. The newly constructedisotope separator KISS will be available for the users in near future.
The activities of CNS, Niigata, and KEK are reported in the following pages.

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIESPartner Institution
Center for Nuclear Study, Graduate School of Science
The University of Tokyo
1. Abstract

The Center for Nuclear Study (CNS) aims to elucidate the nature of nuclear system by producing the characteristic states where theIsospin, Spin and Quark degrees of freedom play central roles. These researches in CNS lead to the understanding of the matter based oncommon natures of many-body systems in various phases. We also aim at elucidating the explosion phenomena and the evolution of theuniverse by the direct measurements simulating nuclear reactions in the universe. In order to advance the nuclear science with heavy-ion
reactions, we develop AVF upgrade, CRIB and SHARAQ facilities in the large-scale accelerators laboratories RIBF. We started a new
project OEDO for a new energy-degrading scheme, where a RF deflector system is introduced to obtain a good quality of low-energy beam.
We promote collaboration programs at RIBF as well as RHIC-PHENIX and ALICE-LHC with scientists in the world, and host international
meetings and conferences. We also provide educational opportunities to young scientists in the heavy-ion science through the graduate
course as a member of the department of physics in the University of Tokyo and through hosting the international summer school.

2. Major Research Subjects
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)

Accelerator Physics
Nuclear Astrophysics
Nuclear spectroscopy of exotic nuclei
Quark physics
Nuclear Theory
OEDO/SHARAQ project
Exotic Nuclear Reaction
Active Target Development

3. Summary of Research Activity(1) Accelerator Physics
One of the major tasks of the accelerator group is the AVF upgrade project that includes development of ion sources, upgrading the
AVF cyclotron of RIKEN and the beam line to CRIB. Development of ECR heavy ion sources is to provide new HI beams, higher andstable beams of metallic ions, and to improve the control system. The Hyper ECR and the Super ECR sources provide all the beams for the
AVF cyclotron and support not only CRIB experiments but also a large number of RIBF experiments. Injection beam monitoring andcontrol are being developed and studied. Detailed study of the optics from the ion sources are expected to improve transmission andqualities of beams for the RIBF facility.
(2) Nuclear Astrophysics
The nuclear astrophysics group in CNS is working for experimental researches using the low-energy RI beam separator CRIB.
The call for proposals for the NP-PAC now includes proposals for CRIB again, and 3 new proposals have been approved in the NP-PAC
meetings in the fiscal year 2014. In May 2014, a measurement of the elastic scattering of 8B+Pb was performed in collaboration with
INFN-LNL (Padova). It was made possible by the special development of intense and energy-enhanced 6Li beam. A unique beam of 8B at 50
MeV and 104 pps was produced, and the measurement was successfully completed.
(3) Nuclear structure of exotic nuclei
The NUSPEQ (NUclear SPectroscopy for Extreme Quantum system) group studies exotic structures in high-isospin and/or high-spinstates in nuclei. The CNS GRAPE (Gamma-Ray detector Array with Position and Energy sensitivity) is a major apparatus forhigh-resolution in-beam gamma-ray spectroscopy. Missing mass spectroscopy using the SHARAQ is used for another approach on exotic
nuclei. In 2014, the following progress has been made.
Experimental data taken in 2013 under the EURICA collaboration are being analyzed for studying octupole deformation in neutron-richnuclei. Gamow-Teller transitions of 8He were studied by the (p,n) reaction in inverse kinematics, where a prominent sharp peak at Ex~8
MeV was found to be the Gamow-Teller resonance. Exothemic charge exchange reactions (8He,8Li*(1+)) on 4He are being analyzed forstudying spin-dipole response of few-body system on the photon line. The tetra-neutron system was studied by the 4He(8He,8Be)4nreaction, which shows a candidate of the ground state of the tetra neutrons just above the 4n threshold as well as continuum at higher
excitation energy.
The readout system of 14 detectors of the CNS GRAPE was upgraded, where digital pulse data taken by sampling ADCs are analyzed by
FPGAs on boards.
(4) Quark Physics
Main goal of the quark physics group is to understand the properties of hot and dense nuclear matter created by colliding heavy
nuclei at relativistic energies. The group has been involved in the PHENIX experiment at Relativistic Heavy Ion Collider (RHIC) at
Brookhaven National Laboratory, and the ALICE experiment at Large Hadron Collider (LHC) at CERN.

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Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

As for PHENIX, the group has been concentrating on the physics analysis involving leptons and photons; dielectron measurement
in Au+Au collisions, dark photon searches in low mass Dalitz decays, and J/ production in ultra-peripheral Au+Au collisions.
As for ALICE, the group has involved in the data analyses, which include the neutral pion production in Pb+Pb collisions, andmeasurement of low-mass lepton pairs in Pb+Pb and p+Pb collisions. The group has involved in the ALICE-TPC upgrade using a Gas
Electron Multiplier (GEM). Performance evaluation of the MicroMegas + GEM systems for the upgrade is performed.
R&D of GEM and related techniques has been continuing. Development of Teflon GEM has been progressing in collaboration with
the Tamagawa group of RIKEN.
(5) Nuclear Theory
The nuclear theory group has been promoting the CNS-RIKEN collaboration project on large-scale nuclear structure calculations since2001 and maintaining its PC cluster. In order to review and promote this collaboration further, an international workshop"Progress in nuclear shell-model calculations in CNS-RIKEN collaboration" was held on Nov. 26-28, 2014.
This group has revealed that the 4+1 of 44S is high-K isomer, and discussed the deformation properties of the high-spin states of neutron-rich
Cr and Fe isotopes utilizing shell-model calculations. A memorandum of understanding on this collaboration has been madebetween CNS and RIKEN in March 2014. In parallel, this group participated in activities of HPCI Strategic
Programs for Innovative Research (SPIRE) Field 5 “The origin of matter and universe” since 2011.
(6) OEDO/SHARAQ project
The OEDO/SHARAQ group promoted high-resolution experimental studies of RI beams by using the high-resolution beamline and
SHARAQ spectrometer. The mass measurement by TOF-B technique was performed for very neutron-rich calcium isotopes around N=34.
For the experiment, we introduced new detector devices into the experiment. Diamond detectors, which were developed as timing counterswith extreme resolution, were installed for measuring time of flight at the first and final foci of the beam line. Clover-type Ge detectors
were installed at the final focal plane of the SHARAQ spectrometer for the first time, enabling particle identification of RI beams byprobing delayed gamma rays from known isomeric states of specific nuclei.
We have started ion optical development for achievement of high-quality RI beams with energies lower than 100 MeV/u. This project
was named OEDO (Optimized Energy-Degrading Optics for RI beam) and the basic magnet arrangement and ion optics was discussed
based on the existing high-resolution beamline and SHARAQ spectrometer.
(7) Exotic Nuclear Reaction
The Exotic Nuclear Reaction group studies various exotic reactions induced by beams of unstable nuclei.
In 2014, a parity transfer probe of the (16O, 16F(g.s)) reaction was demonstrated on 12C at SHARAQ. The proton from the subsequentinstant decay of 16F(g.s.) → 15F+p was detected by a MWDC newly introduced. The kinematical reconstruction of 16F was successful. At
SAMURAI, a measurement of knockout reactions from Borromean nuclei, 11Li and 14Be was performed to study the two-neutron
correlation. Analysis of the 22,24O(p,2p) reaction data obtained in 2012 was almost finished and the spin-orbit splitting of proton 0p orbitals
in 22O was derived.
(8) Active Target Development
In a project of active target development launched as an intergroup collaboration in 2009, two types of active target, called
GEM-MSTPC and CAT, respectively, have been developed. The (,p) reactions on 18Ne, 22Mg and 30S, and the alpha emission following thebeta decay of 16N have been measured using GEM-MSTPC and data analyses are on going. The deuteron inelastic scattering off 132Xe wasmeasured by using the CAT with 106-particles-per-spill 132Xe beam at HIMAC accelerator facility in Chiba.

Members
Director
Takaharu OTSUKA
Scientific Staff
Susumu SHIMOURA (Professor)
Hideki HAMAGAKI (Professor)
Kentaro YAKO (Associate Professor)
Nobuaki IMAI (Associate Professor, June 2014 –)Noritaka SHIMIZU (Project Associate Professor)

Hidetoshi YAMAGUCHI (Lecturer)
Shin'ichiro MICHIMASA (Assistant Professor)
Taku GUNJI (Assistant Professor)
Shinsuke OTA (Assistant Professor)

Guest Scientists
Hiroaki UTSUNOMIYA (Guest Professor)

Yutaka UTSUNO (Guest Associate Professor)

Technical Staff
Norio YAMAZAKI (–Mar. 2014)

Yukimitsu OHSHIRO

Techinical Assistants
Hiroshi KUREI
Takehiko SENOO (–Mar. 2014)

Akira YOSHINO (Jun. 2014–)- 439 -

RIKEN Accel. Prog. Rep. 48 (2015)

Shoichi YAMAKA
Kazuyuki YOSHIMURA

Ⅵ. RNC ACTIVITIESMasahiko TANAKA (Jun. 2014–)
Mamoru KATAYANAGI (Apr. 2014–)

Project Research Associates
Tooru YOSHIDA
Yoritaka IWATA
Post Doctoral Associates
Masanori DOZONO (Apr. 2014 –)Yorito YAMAGUCHI (– May 2014)
Taro NANAO (– Mar. 2014)
Reiko KOJIMA (– Mar. 2014)
David STEPPENBECK (– Oct. 2014)
Tomoaki TOGASHI

Naofumi KADOTA (Apr. 2014–)
Masafumi MATSUSHITA
Yoki ARAMAKI (– Oct. 2014)
Yosuke WATANABE (Apr. 2014–)
Seiya HAYAKAWA (Aug. 2014–)

Graduate Students
David. M KAHL
Akihisa TAKAHARA (–Mar. 2014)
Hiroyuki MIYA
Ryoji AKIMOTO (–Mar. 2014)
Hiroshi TOKIEDA
Tomoya TSUJI
Shintaro GO (–Mar. 2014)
Shoichiro KAWASE
ShinIchi HAYASHI
KeiIchi KISAMORI
Motonobu TAKAKI

Tang T. LEUNG (–Mar. 2014)
Yuko SEKIGUCHIRin YOKOYAMA
Yuki KUBOTA
CheongSoo LEE
Kohei TERASAKI
Motoki KOBAYASHI
Kentaro YUKAWA
Yuji SAKAGUCHIYu KIYOKAWA

Administration Staff
Hiroshi YOSHIMURA
Ikuko YAMAMOTO
Takako ENDO

Yukino KISHI
Toshiko ITAGAKI
Yuko SOMA- 440 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Partner Institution
Center for Radioactive Ion Beam Sciences
Institute of Natural Science and Technology, Niigata University
1. Abstract

The Center for Radioactive Ion Beam Sciences, Niigata University, aims at uncovering the properties of atomic nuclei and heavy elements
and their roles in the synthesis of elements, with use of the advanced techniques of heavy ion and radioactive ion beam experiments as wellas the theoretical methods. Main research subjects include the measurements of various reaction cross sections and moments of neutron- or
proton-rich nuclei, synthesis of super-heavy elements and radio-chemical studies of heavy nuclei, and theoretical studies of exotic nuclei
based on quantum many-body methods and various nuclear models. In addition, we promote interdisciplinary researches related to theradioactive ion beam sciences, such as applications of radioactive isotopes and radiation techniques to material sciences, nuclear
engineering and medicine. Many of them are performed in collaboration with RIKEN Nishina Center and with use of the RIBF facilities.
The center emphasizes also its function of graduate education in corporation with the Graduate School of Science and Technology, Niigata
University, which invites three researchers in RIKEN Nishina Center as visiting professors.

2. Major Research Subjects(1) Reaction cross section and radii of neutron-rich nuclei(2) Production of superheavy nuclei and radiochemistry of heavy elements(3) Nuclear theory

3. Summary of Research Activity(1) Reaction cross section and radii of neutron-rich nuclei
The experimental nuclear physics group has studied nuclear structure with the RI beam. One of our main interests is theinteraction/reaction cross section measurements. They are good probes to investigate nuclear matter radii and nuclear matter distributions
including halo or skin structure. Recently we have measured the interaction sections of Ne, Na, Mg and Al isotopes from stable region toneutron drip line with BigRIPS in RIBF. We found a large enhancement of cross section at 31Ne. It suggests that 31Ne nucleus has a neutron
halo. It is consistent with the soft E1 excitation measurement. We also found an enhancement at 37Mg. For odd-Z nuclei, Na and Al, we did
not find such a large enhancement from neighbor isotopes. The systematics of observed interaction/reaction cross sections shows thechanging of nuclear structure from stable region to neutron drip line via island of inversion.
(2) Production of superheavy nuclei and radiochemistry of heavy elements
The nuclear chemistry group has been investigating decay properties of super-heavy nuclei, measured the excitation functions ofrutherfordium isotopes, and clarified the ambiguity of the assignment of a few-second spontaneously fissioning isotope of 261Rf. The new
equipment designed for measurement of short-lived alpha emitters is under development.
For the chemistry research of super-heavy elements, preparatory experiments, such as solvent extraction for the group 4, 5, and 6thelements and gaseous phase chemistry for group-4 elements, have been performed using radioisotopes of corresponding homolog elements.
(4) Nuclear theory
One of the main activities of the nuclear theory group concerns with developments of the nuclear density functional theory and explorationof novel correlations and excitations in exotic nuclei. A fully selfconsistent scheme of the quasiparticle random phase approximation(QRPA) on top of the Skyrme-Hartree-Fock-Bogoliubov mean-field for deformed nuclei has been developed in the group. The versatility ofthis method to describe the deformation splitting of the giant resonances associated with the onset of deformation has been demonstrated
for the first time by the intensive numerical calculation performed for Nd and Sm isotopes. The same method is further extended to describe
the spin-isospin modes of excitation in deformed neutron-rich nuclei. A successful description of the Gamov-Teller beta-decay transition
rate in the neutron-rich Zr isotopes is achieved with this method. Another correlation of interest in neutron-rich nuclei is the pair correlation,
for which the spatial di-neutron correlation has been a key topic. Applying the continuum QRPA to the pairing modes of excitation in
neutron-rich Sn isotopes, we predict the emergence of an anomalous pair vibration for isotopes with A>132. Furthermore the new mode ispredicted to exhibits the di-neutron character. In addition to these studies, activities related to the proton-neutron pairing, the di-neutron
correlation in the asymptotic tail in drip-line nuclei, the quasiparticle resonances in unbound odd-N nuclei are under way. Cluster structure
and the ab initio studies of light nuclei are also important research subjects of the theory group.

Members
Director
Masayuki MATSUO (Professor)
Scientific Staff
Hisaaki KUDO (Professor)
Takashi OHTSUBO (Associate Professor)
Shin-ichi GOTO (Associate Professor)

Shigeyoshi AOYAMA (Associate Professor)
Takuji IZUMIKAWA (Associate Professor)
Kenichi YOSHIDA (Assistant Professor)- 441 -

RIKEN Accel. Prog. Rep. 48 (2015)

Kazuhiro OOE (Assistant Professor)
Jun GOTO (Assistant Professor)

Ⅵ. RNC ACTIVITIESMaya TAKECHI (Assistant Professor)

Post Doctoral Associates
Hirotaka SHIMOYAMA
Graduate Students
Kazuya HIROKAWA
Yoshihiko KOBAYASHI

Junpei ANZAISho KANESAWA- 442 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Partner Institution
Radioactive Nuclear Beam Group, IPNS (Institute for Particle and Nuclear Studies)
KEK (High Energy Accelerator Research Organization)
1. Abstract
The KEK Isotope Separation System (KISS) has been constructed to experimentally study the β-decay properties of unknown

neutron-rich nuclei with around neutron magic numbers N = 126 for astrophysical interest. In FY2014, first radioactive nuclear beam of
199Pt, which was produced by 136Xe + 198Pt reaction, collected by an Ar gas cell, selectively ionized by a resonant ionization technique andmass-separated, has been successfully extracted from KISS. The measured half-life of extracted 199Pt was good agreement with the reported
value.

2. Major Research Subjects(1) Radioactive isotope beam production and manipulation for nuclear experiments.
(2) Explosive nucleosyhnthesis (r- and rp-process).
(3) Heavy ion reaction mechanism for producing heavy neutron-rich nuclei.
(4) Single particle states of neutron-rich nuclei by isobaric analog resonances.
(5) Development of RNB probes for materials science applications.
3. Summary of Research Activity

The KISS is an element-selective isotope separator using a magnetic mass separator combined with in-gas-cell resonant laser ionization.
The gas cell filled with argon gas of 50 kPa is a central component of the KISS for extracting only the element of interest as ion beam for
subsequent mass separation. In the cell, the element primarily produced by low-energy heavy ion reactions is stopped (thermalization andneutralization), transported by buffer gas (argon gas-flow of ~50 kPa in the present case), and then re-ionized by laser irradiation just before
the exit. The gas cell was fabricated to efficiently correct the reaction products produced by the multi-nucleon transfer reaction of 136Xe +198Pt
system. For the first extraction of the reaction products, the 136Xe beam energy and 198Pt target thickness were set at 10.8 MeV/u and 6 mg/cm2,
respectively. In FY2014, for the half-life measurement, β-ray telescopes and a tape transport system were installed at the focal point of KISS.
The β-ray telescopes were composed of three double-layered thin plastic scintillators; thickness of the first layer and second one were 0.5 and 1
mm, respectively. In order to reduce the background, they were surrounded with low-activity lead blocks and a veto counter system consistingof plastic scintillator bars. The background rate of the present β-ray telescopes was measured to be 0.7 counts per second. After the installationof the detection system, we have successfully extracted laser-ionized 199Pt which mainly formed 199PtAr2+ molecular ions and was transportedwith the mass separator as the molecular ions. The measured half-life of 199Pt was t1/2 = 33(4) min. which was good agreement with the reported
value of 30.8(2) min.
Also, we investigated the extraction efficiency of ions from KISS, using 198Pt elastic scattered particles. The 198Pt was also extracted as
199PtAr + molecule. The extraction efficiency was measured to be about 0.2 % which was independent of the 136Xe primary beam intensities.
2
The obtained selectivity and purity were higher than 300 and 99.7 %, respectively, at the maximum primary beam intensity of 20 pnA. In orderto improve the extraction efficiency, we have started to install a new sextupole ion-guide (SPIG) at the exit of the gas cell with lager angular
acceptance, which is divided into two parts with different apertures of 8 and 3 mm diameters, respectively. At the off-line test for the newly
installed SPIG, we have clearly observed the dissociation of molecular ions of laser-ionized iridium, by applying DC voltage between first andsecond parts of the SPIG. We can expect to improve the extraction efficiency, at least, by a factor of 1.5. In FY2015, we will perform theon-line test for the new SPIG to measure the improved extraction efficiency.
For measurements of half-lives of unknown neutron-rich nuclei on N = 126, the present background rate of β-rays telescopes is not low
enough. We have constructed a new β-rays telescopes in which ∆E plastic scintillator would be exchanged to a smaller one. We can expect toreduce the background rate by several factors. Further, we have started to develop a gas counter as a ∆E counter to realize the background rateof our goal, several counts per hour or less.
As a continuing effort for search for effective laser ionization scheme of elements of our interest (Z<82), a reference cell was fabricated,
and is currently being used to search for auto ionizing states in Ta, W, and etc…
In order to investigate the feasibility of the multi-nucleon transfer (MNT) in the reaction system of 136Xe on 198Pt for producing
heavy neutron-rich isotopes around the mass number of 200 with the neutron magic number of 126, We performed the cross section
measurement at GANIL in 2012 and the analysis of the data has been almost completed. The cross sections of target-like fragments
around N =126 were comparable to those estimated using the GRAZING code, and they appear to be mainly contributed by the reactions with
low total energy loss with the weak N/Z equilibration and particle evaporation. This suggests the promising use of the MNT reactions with aheavy projectile at the energies above the Coulomb barrier for production of the neutron-rich isotopes around N = 126.
The diffusion coefficient of lithium in solid materials used in secondary Li-ion batteries is one of key parameters that determine how fast abattery can be charged. The reported Li diffusion coefficients in solid battery materials are largely scattered over several order of magnitudes.
We have developed an in-situ nanoscale diffusion measurement method using α-emitting radioactive 8Li tracer. In the method, while
implanting a pulsed 8Li beam of 8 keV, the alpha particles emitted at a small angle (θ = 10 ± 1◦) relative to a sample surface were detected
as a function of time. We can obtain Li diffusion coefficient from the time dependent yields of the α particles, whose energy loss can beconverted to nanometer-scale position information of diffusing 8Li. The method has been successfully applied to measure the lithium
diffusion coefficients for an amorphous Li4SiO4 - Li3VO4 (LVSO) which was used as a solid electrotype in a solid-state Li thin film battery, well

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

demonstrating that the present method has the sensitivity to the diffusion coefficients down to a value of 10-12 cm2/s, corresponding withnanoscale Li diffusion. From FY2014, we have started to measure Li diffusion coefficients in a spinel type Li compound of LiMn2O4 (LMO),
which is used as a positive electrode of a Li battery in an electric vehicle. We have observed a significant change on the time dependent yieldsof the α particles at the sample temperature of around 623 K and will continue the measurements to obtain temperature dependency of Li
diffusion coefficients in LMO.

Members
Group Leader
Hiroari MIYATAKE
Members
Yoshikazu HIRAYAMA
Nobuaki Imai
Yutaka WATANABE
Hironobu ISHIYAMA
Sunchan JEONG

Michihiro OYAIZU
Hyo-Soon Jung
Yung-Hee KIM (PhD. Student, Seoul National Univ.)
Momo MUKAI (PhD. Student, Tsukuba Univ.)
Sota KIMURA (PhD. Student, Tsukuba Univ.)- 444 -

Ⅵ. RNC ACTIVITIESRIKEN Accel. Prog. Rep. 48 (2015)

Events (April 2014 - March 2015)
RIKEN
Apr. 10 - 11

The 3rd EURICA Workshop

Apr. 19

Wako Open campus

Jun. 1 - 6
Jun. 27 - 28

The 2nd Conference on "Advances in Radioactive Isotope Science" (ARIS2014)
http://ribf.riken.jp/ARIS2014/
The 14th NP-PAC

Jul. 1 - 3

Nishina Center Advisory Council

Jul. 28– Aug. 8
Aug. 7

Nishina School

Aug. 31- Sep. 5
Oct. 1

Dec. 10The 27th International Conference of the International Nuclear Target Development Society (INTDS-2014)
http://ribf.riken.jp/intds2014/
Start of Nuclear Transmutation Data Research Group associated with following three teams
Fast RI Data Team, Slow RI Data Team and Muon Data Team
Start of High-Intensity Accelerator R&D Group associated with following two teams
High-Gradient Cavity R&D Team and High-Power Target R&D TeamThe 6th International Conference on Trapped Charged Particles and Fundamental Physics (TCP2014)
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1395
Effect of MOU between Universitas Hasanuddin, Indonesia and RNC

Dec. 12 - 13

The 15th NP-PAC

Jan. 5

Effect of MOU between RNC and Peking University

Jan. 8 - 9

The 11th ML-PAC

Mar. 31

End of Mathematical Physics Laboratory led by associate chief scientist Koji Hashimoto

Dec. 1-5

The 4th In-PAC

CNSAug. 28- Sep. 03

The 12th CNS international Summer School (CNSS13)
http://indico.cns.s.u-tokyo.ac.jp/conferenceDisplay.py?confId=81

Niigata Univ.
not held in FY2014

KEK
Aug, 21-28

KEK Summer Challenge 2014
http://www2.kek.jp/ksc/8th_2014/index.html- 445 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅵ. RNC ACTIVITIES

Press Releases (April 2014 - March 2015)
RNC
Apr. 11

Elucidation of exotic structures in very neutron-rich nuclei-a unified picture for neutron-halo, magicity-loss and large deformation-

Joint PR: Released from Tokyo Tech.

Apr. 24Hyperfine structure constant of the single neutron halo nucleus 11Be+ has been precisely
measured to be A= -2677.302988±0.000072 MHz using laser microwave double
resonance spectroscopy.

Michiharu WADA
(SLOWRI Team)

Jun. 18

Neutron Halo Appears in a Neutron-rich Magnesium Isotope---Suggesting that neutron halo is a more common feature of heavier, extremely
neutron-rich nuclei---

Joint PR: Released from Tokyo Tech.

Jul. 22

Rewriting the history of volcanic forcing during the past 2000 years ---A
year-by-year record of volcanic eruptions from a comprehensive Antarctic ice
core array---

Yuko MOTIZUKI(Astro-Glaciology Research Unit)
Joint PR with Desert Research InstituteAug. 29

Nickel-78 has been confirmed to be a 'doubly magic' isotope-- Precise beta-decay half-life measurement of 78Ni --Z. Y. Xu & Shunji Nishimura(Radioactive Isotope Physics Lab.)
Joint PR with the Univ. of Tokyo

Sep. 18

SUZAKU studies of the central engine in the typical Type I seyfert NGC 3227:
Detection of multiple primary X-ray continua with distinct properties

Hirofumi Noda
(High Energy Astrophysics Lab.)
Joint PR with the Univ. of Tokyo

Sep. 18

Efficient production of muonium at room temperature--Stringent survey of deviation from the standard model of particle physics comes closer toreality in Japan---Katsuhiko Ishida(Advanced Meson Science Lab.)
Joint PR: Released from KEK

Sep. 19

Synthesis of a carbonyl complex of element 106, seaborgium (Sg)---Sg shows chemical properties characteristic to the group-6 elements in the periodic
table---

Hiromitsu Haba (RI Applications Team)
Joint PR with JAEA

Feb. 13

Muonium in Stishovite: Implications for the Possible Existence of Neutral Atomic Hydrogen in Dai Tomono & Teiichiro MATSUZAKI
the Earth’s Deep Mantle(Muon Data Team)
Released from the University of Tokyo

Mar. 9Ensuring food safety using space technology---technology originally designed for use in outer space to create a new system, called
LANFOS, which can inexpensively and non-destructively detect radioactive cesium
contamination in food---- 446 -

Hiromitsu Haba (RI Applications Team)
Joint PR with GTEC

VII. LIST OF PUBLICATIONS& PRESENTATIONS

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

RIKEN Nishina Center for Accelerator-Based Science
Publications[Book・Proceedings]（Proceedings）
Enyo H.: “RIKEN Radio Isotope Beam Factory:Japanese
Flagship for Nuclear Science”, Proceedings of the firstinternational African Symposium on Exotic Nuclei(IASEN-2013), (iThemba LABS), Cape Town, South
Africa, pp. 43–52 (2014).
Oral Presentations(International Conference etc.)
Enyo H.: “Status and Prospect of J-PARC E16”, Hadron
Physics Symposium, (Nagoya University), Nagoya,Japan, April. (2014).
Motobayashi T.: “Coulomb dissociation for studies of astrophysical reactions - achievements and perspectives”,
Workshop on Indirect Measurement Methods of Nuclear
Astrophysics Reaction Cross Sections, (Anhui University), Hefei, China, May. (2014).
Motobayashi T.: “Nuclear astrophysics studies at RIKEN
RIBF”, Carpathian Summer School for Physics 2014,(”Horia Hulubei” National Institute for Physics and Nuclear Engineering, Bucharest), Sinaia, Romania, July.
(2014).
Motobayashi T.: “Coulomb dissociation for astrophysics
studies”, PKU-CUSTIPEN Nuclear Reaction Workshop, (Pekin University), Beijing, China, Aug. (2014).
Enyo H.: “RIKEN RI Beam Factory”, The VII International Symposium on Exotic Nuclei (EXON-2014), (Immanuel Kant Baltic Federal University), Kaliningrad,
Russia, Sep. (2014).
Motobayashi T.: “Roles of simulation in spectroscopy withRI Beams”, The International Workshop on Nuclear Science and Simulation in Fundamental and Applied Researches (IWNSS), (Ton Doc Thang University), Ho Chi
Minh City, Vietnam, Oct.-Nov. (2014).
Motobayashi T.: “Nuclear astrophysics studies with fast
RI beams at RIKEN RIBF”, The International Symposium on Physics of Unstable Nuclei 2014 (ISPUN14),(INST, Hanoi), Ho Chi Minh City, Vietnam, Nov.
(2014).
Motobayashi T.: “Experimental Studies with Magnetic
Devices at RIBF”, NUSTAR Annual Meeting, (GSI),
Darmstadt, Germany, Mar. (2015).

- 447 -

1

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Quantum Hadron Physics Laboratory
Publications[Journal]（Original Papers） *Subject to Peer Review
Tanizaki Y.: “Lefschetz-thimble techniques for path integral of zero-dimensional O(n) sigma models”, Phys.
Rev. D 91, 036002 (2015)*.
Tanizaki Y. and Koike T.: “Real-time Feynman path integral with Picard–Lefschetz theory and its applications
to quantum tunneling”, Annals of Physics 351, 250(2014)*.
Tanizaki Y.: “Many-body composite bosons from theviewpoint of functional renormalization”, Bulg. J. Phys.
41, no.2, 180 (2014)*.
Kashiwa K., and Tanizaki Y.: “Phase structure of SU (3)gauge-Higgs uniﬁcation models at ﬁnite temperature”,
Phys. Rev. D 89, 116013 (2014)*.
Naidon P., Endo S., and Ueda M. :“Physical origin of
the universal three-body parameter in atomic Eﬁmov
physics ”,Phys. Rev. A90, 022106(2014)*.
Naidon P., Endo S., and Ueda M. :“Microscopic Origin
and Universality Classes of the Eﬁmov Three-Body Parameter ”,Phys. Rev. Lett112, 105301(2014)*.
Cho S., Hattori K., Lee S. H., Morita K., and Ozaki S.:“Charmonium Spectroscopy in Strong Magnetic Fields
by QCD Sum Rules: S-Wave Ground States”, Phys.Rev.
D 91, 045025 (2015)*.
Cho S., Hattori K., Lee S. H., Morita K., and Ozaki
S.: “QCD Sum Rules for Magnetically Induced Mixing between ηc and J/ψ”, Phys.Rev. Lett. 113, 172301(2014)*.
Fejos G., Patkos A, and Szep Z: “Renormalized O(N)model at next-to-leading order of the 1/N expansion: Eﬀects of the Landau pole”, Phys.
Rev.
D90,016014(2014)*.
Fejos G.: “Fluctuation induced ﬁrst order phase transitionin U(n)xU(n) models using chiral invariant expansionof functional renormalization group ﬂows”, Phys. Rev.
D90,096011(2014)*.
Fejos G.: “Renormalization of the 2PI-Hartree approximation in a broken phase with nonzero superﬂow”, Phys.
Rev. D90,116001(2014)*.
Misumi T. and Kanazawa T. :“Adjoint QCD on R3 × S 1
with twisted fermionic boundary conditions ”, JHEP06,
181 (2014)*.
Kanazawa T. and Wettig T. :“Stressed Cooper pairing in
QCD at high isospin density: eﬀective Lagrangian andrandom matrix theory ”, JHEP10, 055(2014)*.
Kamikado K. and Kanazawa T. :“Magnetic susceptibility of a strongly interacting thermal medium with 2+1
quark ﬂavors ”, JHEP01, 129(2015)*.
Kanazawa T. and Yamamoto A. : “Asymptotically freelattice gauge theory in ﬁve dimensions ”, Phys. Rev.
D91, 074508(2015)*.

- 448 -

Kanazawa T. and Tanizaki Y. : “Structure of Lefschetz thimbles in simple fermionic systems ”, JHEP03,044(2015)*.
Tachibana Y., and Hirano T. :“Momentum transport awayfrom a jet in an expanding nuclear medium ”,Phys. Rev.
C90, 021902(R) (2014)*.
Hirono Y., Hongo M., and Hirano T. :“Estimation of
the electric conductivity of the quark gluon plasma via
asymmetric heavy-ion collisions ”,Phys. Rev. C90,
021903(R) (2014)*.
Aoyama T., Hayakawa M., Kinoshita T., and Nio M.
:“Tenth-order electron anomalous magnetic moment:
Contribution of diagrams without closed lepton loops”,Phys. Rev. D91, 033006 (2015)*.
Baym G., Hatsuda T.: “Polarization of Direct Photons
from Gluon Anisotropy in Ultrarelativistic Heavy Ion
Collisions”, PTEP2015,031D01 (2015)*.
Asakawa M., Hatsuda T., Itou E, Kitazawa M., Suzuki H.
(FlowQCD Collaboration): “Thermodynamics of SU(3)gauge theory from gradient ﬂow on the lattice”, Phys.
Rev. D90,011501(R) (2015)*.
Inoue T., Aoki S., Charron B., Doi T., Hatsuda T.,
Ikeda Y., Ishii N., Murano K., Nemura H., and Sasaki
K. (HAL QCD Collaboration) :“Medium-Heavy Nuclei from Nucleon-Nucleon Interactions in Lattice QCD”,Phys. Rev. C91,011001(R) (2015)*.
Deka M., Doi T., Yang Y.B, Chakraborty B., Dong S.J.,
Draper T., Glatzmaier M., Gong M., Lin H.W., Liu
K.F., Mankame D., Mathur N., and Streuer T. (χQCD
Collaboration) :“A Lattice Study of Quark and Glue
Momenta and Angular Momenta in the Nucleon ”,Phys.
Rev. D91,014505 (2015)*.
Etminan F., Nemura H., Aoki S., Doi T., Hatsuda T.,
Ikeda Y., Inoue T., Ishii N., Murano K., and Sasaki K.
(HAL QCD Collaboration) :“Spin-2 N Ω Dibaryon from
Lattice QCD ”,Nucl. Phys. A928,89 (2014)*.
Murano K., Ishii N., Aoki S., Doi T., Hatsuda T., Ikeda Y.,
Inoue T., Nemura H., and Sasaki K. (HAL QCD Collaboration) :“Spin-Orbit Force from Lattice QCD ”,Phys.
Lett. B735,19 (2014)*.
Gale C., Hidaka Y., Jeon S., Lin S., Paquet J. -F., Pisarski
R. D., Satow V. V., and Vujanovic G. :“Production andElliptic Flow of Dileptons and Photons in the semiQuark Gluon Plasma”, Phys. Rev. Lett.114, 072301(2015)*.
Hayata T. and Hidaka Y. :“Dispersion relations of NambuGoldstone modes at ﬁnite temperature and density”,
Phys. Rev. D91, 056006 (2015)*.
Anzaki R., Fukushima K., Hidaka Y., and Oka T. :“Restricted phase-space approximation in real-time stochastic quantization”, Ann. Phys353, 107 (2015)*.
Hayata T., Hidaka Y., and Yamamoto A.: “Temporal Chiral Spiral in Strong Magnetic Fields”, Phys. Rev. D89,
085011 (2014)*.
Hayata T. and Hidaka Y. :“Broken spacetime symmetries

1Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

and elastic variables”, Phys. Lett. B735, 195 (2014)*.
（Review）
土井琢身, “格子 QCD シミュレーションによるハドロン間相互作用の解明”, 原子核研究第 58 巻 1 号, 109 (2013)*
土井琢身, “格子 QCD シミュレーションで解き明かす核力の謎”, 日本シミュレーション学会誌第 32 巻 1 号, 16 (2013)*[Book・Proceedings]（Original Papers） *Subject to Peer Review
Tachibana Y., and Hirano T. :“Di-jet asymmetric momentum transported by QGP ﬂuid”, Nucl. Phys. A932,
387–391 (2014)*.
Krejcirik V. :“Nucleon-nucleon scattering in the large Nc
limit ”,submitted to JPS Conference Proceedings.*
Oral Presentations(International Conference etc.)
Tachibana Y., and Hirano T. : “Collective dynamics in dijet+QGP-ﬂuid system”, Fourth Joint Meeting of the Nuclear Physics Divisions of the American
Physical Society and the Physical Society of JapanWaikoloa,Hawaii,October(2014).
Tachibana Y., and Hirano T. : “Momentum Transport in Dijet+QGP-ﬂuid”, Quadrangle2014, HighEnergy Strong Interactions: A School for Young
Asian ScientistsCentral China Normal University,Wuhan,China,September(2014).
Tachibana Y., and Hirano T. : “Momentum ﬂow indijet+QGP-ﬂuid system”, ATHIC 2014,Osaka University,Osaka,August(2014).
Tachibana Y., and Hirano T. :“Collective ﬂow
induced by energetic partons in heavy-ion collisions”, The 26th Heavy Ion Cafe,The University ofTokyo,Tokyo,July(2014).
Hongo M., Hayata T., Yoshimasa H., Minami Y.,
and Noumi T. : “Derivation of anomalous hydrodynamics from quantum ﬁeld theory”, Fourth Joint Meeting of the Nuclear Physics Divisions of the American
Physical Society and the Physical Society of JapanWaikoloa,Hawaii,October(2014).
Hongo M., Hirono Y., and Hirano T. “Anomaly-induced
transport in heavy-ion collisions”, ATHIC 2014,Osaka
University,Osaka,August(2014).
Kanazawa T.: “Matrix model for high-density QCD
with mismatched chemical potentials”, Workshop on
QCD under extreme conditions (XQCD2014) New
York,USA,June(2014).
Kanazawa T.: “Matrix model for high-density QCD
with mismatched chemical potentials”, High Energy
Strong Interactions: A School for Young Asian Scientists Wuhan,China,Sep.(2014).
Fejos G.: “Finite temperature chiral symmetry restoration with functional renormalization group methods”, Theoretical physics seminar at Wigner RCPBudapest,Hungary, January( 2015).
Hidaka Y, “Magnetic Catalysis vs. Magnetic Inhibition ”,- 449 -QCD Chirality Workshop 2015, Los Angeles, USA, Jan.
(2015).
Hidaka Y, Hayata T,: Hongo M,: Minami Y,: Noumi T.:“Relativistic hydrodynamic equations and eﬀective Lagrangian from quantum ﬁeld theory”, 4th Joint Meetingof the APS Division of Nuclear Physics and the PhysicalSociety of Japan, Hawaii, USA, Oct. (2014).
Hidaka Y. “Spontaneous symmetry breaking and NambuGoldstone modes in QCD matter”, XIth Quark Conﬁnement and the Hadron Spectrum, Saint Petersburg,
Russia, Sep. (2014).
Hidaka Y. “Dispersion relation of Nambu-Goldstone
modes at ﬁnite temperature and density”, The international workshop ”Higgs Modes in Condensed Matterand Quantum Gases”, Kyoto, Japan, Jun. (2014).
Tanizaki Y.: “Lefschetz-thimble Path Integral and Spontaneous Symmetry Breaking of Matrix Models”, Frontiers of Hadron PhysicsBrookhaven National Laboratory, USA, Feb.(2015).
Tanizaki Y.: “Functional renormalization group approachfor composite-particle excitations”, Algebraic Methods
in Quantum Field Theory, Soﬁa, Bulgaria, July(2014).
Yoshida S.: “Perturbative Matching of the Quasi-PDFs inContinuum Space and Lattice Space”, The 21st International Symposium on Spin Physics, Beijing, China, Oct.
(2014).
Nio M.: “QED tenth-order contribution to the electron g-2
and a new value of the ﬁne structure constant”, Fundamental Constants Meeting 2015, Eltville, Germany, Feb.
(2015).
Krejcirik V.: “Eﬀective model for K̄N interactions including the L = 1 partial wave”, Hadrons and Hadron Interactions in QCD – Eﬀective theories and Lattice, YITP,
Japan, Mar. (2015).
Krejcirik V.: “Eﬀective model for K̄N interactions including the L = 1 partial wave”, Workshop on Progress on
J-PARC hadron physics, Tokai, Japan, Nov. (2014).
Krejcirik V.: “Nucleon-nucleon scattering in the large Nc
limit”, The 2nd International Symposium on Science at
J-PARC (J-PARC 2014), Tsukuba, Japan, Jul. (2014).
Kota Masuda,Muneto Nitta: “Eﬀects of Magnetic Field
and Rotation on 3 P2 Superﬂuidity in Neutron Stars”,
Hawaii 2014 Waikoloa, Hawaii, USA, Oct. (2014).
Kurita R.: “Entropy ﬂuctuation from Hydrodynamic
noise” The 5th Asian Triangle Heavy Ion Conference
2014 Osaka,Japan, Aug.(2014).
Kurita R.: “Fluctuation theorem in Bjoreken expansion”
4th Joint Meeting of the Nuclear Physics Divisons of the
APS and JPS Hawaii,USA Oct.(2014).
Hatsuda T.: “SU(3) Thermodynamics from Yang-Mills
Gradient Flow”, Hadrons and Hadron Interactions in
QCD – Eﬀective theories and Lattice – (HHIQCD2015),
YITP, Japan, March 2-6 (2015).
Hatsuda T.: “Zc and Tcc from Lattice QCD with HAL
QCD method”, KEK Flavor Factory Workshop / Belle

2

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONSII Theory Interface Platform Meeting, KEK, Japan, Oct.
31 (2014).
Hatsuda T.: “From QCD to Compact Stars”, Advancesand Perspectives in Computational Nuclear Physics
Hawaii, USA, Oct. 6, (2014).
Hatsuda T.: “Physics with Hadrons at J-PARC”, 2nd International Symposium on Science at J-PARC (J-PARC
2014) , Tsukuba, Japan, July 12-16, (2014).
Hatsuda T.: “New Approach to Lattice QCD Thermodynamics from Yang-Mills Gradient Flow”, Quark Matter
2014, Darmstadt, Germany, May 19-24, (2014).
Hatsuda T.: “Hadron Physics at Finite Density”, Hadron
Physics Symposium, Nagoya, Japan, April 19, (2014).
Doi T.: “Three-Nucleon Forces from Lattice QCD”,
Hadrons and Hadron Interactions in QCD – Eﬀective
theories and Lattice – (HHIQCD2015), YITP, Japan,
Feb.-Mar. (2015).
Doi T.: “HAL QCD method for hadron interactions on thelattice”, Multi-Hadron and Nonlocal Matrix Elements in
Lattice QCD (MNME 2015), BNL, USA, Feb. (2015).
Doi T.: “Charmed Tetra-quark states in Lattice QCD –Interactions from HAL QCD method–”, The International Workshop on Heavy Quarkonium 2014 (Quarkonium 2014) CERN, Switzerland, Nov., (2014).
Doi T.: “Recent development in Lattice QCD studies for
Three-Nucleon Forces”, Fourth Joint Meeting of the Nuclear Physics Divisions of the APS and JPS (Hawaii2014), Hawaii, USA, Oct., (2014).
Doi T.: “Quark mass dependence of three-nucleon forcesin lattice QCD”, The 32nd International Symposium on
Lattice Field Theory (Lattice 2014), New York, USA,
Jun., (2014).
Ogawa N.: ”Entanglement Entropy of de Sitter Space αVacua ”, YITP workshop “Holographic vistas on Gravity
and Strings ”,YITP,Kyoto,Japan,May,(2014).
Ogawa N.:, ”Entanglement Entropy of de-Sitter Space
α-Vacua ”, YITP workshop “Strings and Fields ”,
YITP,Kyoto,Japan,July,(2014).
Ogawa N.: ”Statistical Mechanics of Cell Mosaic Patternsin Fish Eyes ”, RIKEN-Osaka-OIST-Taiwan mathphys
workshop,OIST,Okinawa,Japan,March,(2015).
Ogawa N.: “Entanglement Entropy of de Sitter Space αVacua ”, Strings Conference 2014, Poster session, Princeton,USA,June(2014).
(Domestic Conference)
Hongo M., Hayata T., Yoshimasa H., Minami Y.,
and Noumi T. : “Derivation of second order relativistic hydrodynamics from quantum ﬁeld theory”, Spring
Meeting of Physical Society of Japan 2015Waseda University,Tokyo,March(2015).
Hongo M., Hirono Y., and Hirano T. “Chiral magnetic wave and charge-dependent elliptic ﬂow from
relativistic hydrodynamic model”, Autumn Meetingof Physical Society of Japan 2014,Tokai University,Kanagawa,September(2014).

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金澤拓也, “Exotic QCD on compactiﬁed spacetime”, 基研
研究会 素粒子物理学の進展 2014 京都, 日本,7 月 (2014).
金澤拓也, 山本新: “格子上の Lifshitz 型ゲージ理論の研究”,
日本物理学会 第 70 回年次大会東京, 日本,3 月 (2015).
Fejos G.: “Chiral symmetry restoration with functional
renormalization group methods”, Workshop on J-Parc
hadron physics in 2014Tokai, Japan ,December(2014).
Hattori K.: “Charmonium spectroscopy in strong magnetic ﬁelds by QCD sum rules”, Hadrons and HadronInteractions in QCD – Eﬀective theories and Lattice– (HHIQCD2015), YITP, Kyoto Univ., Japan, Mar.
(2015).
Hattori K.: “Photon propagation in strong magnetic
ﬁelds”, QCD Chirality Workshop 2015, UCLA, USA,
Jan. (2015).
Cho S., Hattori K., Lee S. H., Morita K., and Ozaki
S., “Charmonium spectroscopy in strong magnetic ﬁelds
by QCD sum rules”, Fourth Joint Meeting of the Nuclear Physics Divisions of the American Physical Society
and The Physical Society of Japan, Hawaii, USA, Oct.
(2014).
多田司, “On the inﬁnite circumference limit of CFT”, 日本物理学会年会早稲田大学, 3 月 (2015).
日高 義将: “QGP の基礎的性質概観（粘性など）”, チュー
トリアル研究会「重イオン衝突の物理：基礎から最先端まで」和光, 日本, 3 月 (2015).
日高 義将, 早田智也, 本郷優, 南佑樹, 野海俊文: “相対論的流体の有効ラグランジアンと自発的対称性の破れ”, 日本物理学会第 70 回年次大会東京, 日本, 3 月 (2015).
日高 義将: “自発的対称性と南部ゴールドストーンモード”,
理研研究会「これからの弦理論 – 橋本研 closing 研究会–」和光, 日本, 2 月 (2015).
日高 義将: “自発的対称性の破れと南部-Goldstone モード”,
理研シンポジウム・iTHES 研究会 「熱場の量子論とその応用」和光, 日本, 9 月 (2014).
谷崎 佑弥, 小池貴之: “実時間経路積分への Lefschetz thimble法の応用とトンネル効果”, 日本物理学会年会早稲田大学,
東京,3 月 (2015).
益田晃太, 新田宗土: “中性子 3 P2 超流動体における磁場と回転の効果 (I)”, 日本物理学会第 70 回年次大会 早稲田大学,
日本, 3 月 (2015).
土井 琢身: “Lattice QCD approach for Three-Nucleon
Forces”, Workshop on Nuclear many-body physics based
on QCD RCNP, 日本, 12 月 (2014).
土井 琢身: “Lattice QCD approach for Three-Nucleon
Forces”, Workshop on Nuclear many-body physics based
on QCD RCNP, 日本, 12 月 (2014).
土井琢身: “Calculation of Nucleon Spin in Lattice QCD”,
Workshop on High-energy QCD and nucleon structure
Tokyo Institute of Technology, 日本, 5 月 (2014).
小川軌明, 飯塚則浩, 野海俊文: “Entanglement Entropy ofde-Sitter Space α-Vacua”, 日本物理学会秋季大会, 佐賀大学,9 月,(2014).
小川軌明: “時間発展系のエンタングルメントとホログラ
フィー”, 理研研究会「これからの弦理論 –橋本研 closing

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

研究会–」 理化学研究所, 和光,2 月,(2015).
小川軌明, 橋本幸士, 山口康宏: “ホログラフィック模型による
重クォーコニウムのスペクトラムとスピン縮退”, 日本物理学会年次大会, 早稲田大学,3 月,(2015).

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Ⅶ. LIST OF PUBLICATIONS

Theoretical Nuclear Physics Laboratory
Publications[Journal]（Original Papers） *Subject to Peer Review
Nakatsukasa T.: “Finite amplitude method in linear response TDDFT calculations”, Journal of Physics: Conference Series 533, 012054 (2014). ＊Matsuo M., Hinohara N., Sato K., Matsuyanagi K.,
Nakatsukasa T., and Yoshida K.: “Quadrupole shape
dynamics from the viewpoint of a theory of largeamplitude collective motion”, Phys. Scr. 89, 054020(2014). ＊Inakura T., Horiuchi W., Suzuki Y., and Nakatsukasa T.:“Mean-ﬁeld analysis of ground state and low-lying electric dipole strength in 22 C”, Phys. Rev. C 89, 064316(2014). ＊Ebata S., Nakatsukasa T., and Inakura T., : “Systematic investigation of low-lying dipole modes using the canonical-basis time-dependent Hartree-FockBogoliubov theory”, Phys. Rev. C 90, 024303 (2014).
＊
Sihver L., Kohama A., Iida K., Oyamatsu K., Hashimoto
S., Iwase H., and Niita K.: “Current status of the ”Hybrid Kurotama model” for total reaction cross sections”,
Nucl. Instrum. Meth. B 334, 34–39 (2014). ＊Sihver L., Lantz M., Kohama A., “Improved parametrization of the transparency parameter in Kox and Shenmodels of total reaction cross sections”, Phys. Rev. C
89, 067602-1–067602-4 (2014). ＊Dinh Dang N.: “Thermal pairing and giant dipole resonance in highly excited nuclei”, J. Phys.: Conf. Series
580, 01205-1–01205-6 (2015). ＊Dinh Dang N.: “Viscosity: From air to hot nuclei”, Pramana - journal of physics 83, 683–693 (2014). ＊Rhine Kumar A.K., Arumugam P., Dinh Dang N.: “Pairing eﬀect in thermal shape ﬂuctuation model on thewidth of giant dipole resonance”, Phys. Rev. C 90,
044308-1 – 044308-6 (2014). ＊Washiyama K.: “Fusion and quasi-ﬁssion in heavy systems with the microscopic time-dependent energy density functional theory”, EPJ Web Conf. 86 00062-100062-4 (2015).*
Van Giai N., Liang H.Z., Gu H.-Q., Long W.H., and Meng
J.: “Treating Coulomb exchange contributions in relativistic mean ﬁeld calculations: why and how”, Phys.
Scr. 89 054008 (2014) ＊.
Liang H.Z., Nakatsukasa T., Niu Z.M., and Meng J.:“Finite-amplitude method: an extension to the covariant density functionals”, Phys. Scr. 89, 054018 (2014)＊.
Liang H.Z., Meng J., Shen S.H., Van Giai N., Zhang S.Q.,
Zhang Y., and Zhao P.W.: “Pseudospin symmetry: Recent progress with supersymmetric quantum mechanics”, Journal of Physics: Conference Series 533, 012020(2014).
Sheikh J. A., Hinohara N., Dobaczewski J., NakatsukasaT., Nazarewicz W., and Sato K.: “Isospin-invariant
Skyrme energy-density-functional approach with axial
symmetry”, Phys. Rev. C 89, 054317-1–054317-12(2014). ＊Tanabe K., and Sugawara-Tanabe K.: “Nuclear momentof inertia as an indicator of the phase transition”, Phys.
Rev. C 91, 034328 (2015). ＊Sugawara-Tanabe K., Tanabe K., and Yoshinaga N.:“Analysis of the triaxial, strongly deformed bands in
odd-odd nucleus 164Lu with the tops-on-top model”,
Progress of Theoretical and Experimental Physics 2014,
063D0 (2014). ＊（Review）
Liang H.Z., Meng J., and Zhou S.-G.: “Hidden pseudospin
and spin symmetries and their origins in atomic nuclei”,
Physics Reports 570, pp. 1–84 (2015). ＊Oral Presentations(International Conference etc.)
Nakatsukasa T.: “Mean-ﬁeld calculations for IoI”, RIBF
Discussion Plus!: Island of Inversion, (RIKEN), Wako,
Apr. (2014).
Nakatsukasa T.: “Nuclear response and equation of state”,
APCTP Workshop on the intersection of cold-atomic
and nuclear physics, (APCTP), Pohang, Korea, May(2014).
Nakatsukasa T.: “Nuclear structure studies with energy density functionals”, International workshop on
Progress in nuclear shell-model calculations in CNSRIKEN collaboration, (RIKEN/University of Tokyo),
Wako, Nov. (2014).
Nakatsukasa T.: “Isospin invariant energy density functional and isobaric analogue states”, International Symposium on Physics of Unstable Nuclei 2014, (Institutefor Nuclear Science and Technology), Ho Chi Minh City,
Vietnam, Nov. (2014).
Nakatsukasa T.: “Time-dependent density functional calculation of nuclear response functions”, International
Conference: Nuclear Theory in the Supercomputing Era- 2014, (Paciﬁc National University), Khabarovsk, Russia, June. (2014).
Nakatsukasa T.: “Time-dependent approaches to nuclear
many-body dynamics”, International Workshop on New
Frontier of Numerical Methods for Many-Body Correlations, (University of Tokyo/CMSI), Tokyo, Feb. (2015).
Makinaga A., Ebata S., Aikawa M., Furutachi N.,
Ichinkhorloo D., Kato K., Odsuren M., Devi V., Otuka
N., Kohama A., Otsu H., and Sakurai H.: “Compilationof Nuclear Reaction Data from RIBF”, 2nd Conference
on Advances in Radioactive Isotope Science (ARIS2014),(RIKEN Nishina Center, CNS), Tokyo, Jun. (2014)
Dinh Dang N.: “Recent achievements in the study ofhighly excited nuclei: Thermal pairing and giant dipole- 452 -

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

resonance”, International Symposium on Physics of Unstable Nuclei (ISPUN14), (INST and LIA), HoChiMinh
City, Nov. (2014).
Dinh Dang N.: “Eﬀect of thermal ﬂuctuations in the pairing ﬁeld on the width of giant dipole resonance”, International Workshop on Nuclear Science and Simulationin fundamental and applied researches, (TonDucThang
University), HoChiMinh City, Oct. - Nov. (2014).
Dinh Dang N.: “Recent achievements in the study ofthermal pairing and giant resonances in highly excited nuclei”, 2nd International Workshop on Theoretical and Computational Physics, (Institute of Theoretical
Physics and Vietnam Physics Society), Buon Ma Thuot,
July (2014).
Dinh Dang N.: “Thermal pairing and giant dipole resonance in highly excited nuclei”, 11th international spring
seminar on nuclear physics, (University of Napoli), Ischia, May (2014).
Washiyama K.: “Microscopic analysis of fusion hindrance
in heavy systems”, Advances in Radioactive Isotope Science, (RIKEN/University of Tokyo), Tokyo, Japan, Jun.
(2014).
Washiyama K.: “Fusion hindrance and extra push infusion reactions with heavy nuclei”, Nuba Conference
Series-1: Nuclear Physics and Astrophysics, (Akdeniz
University), Antalya, Turkey, Sep. (2014).
Washiyama K..: “Microscopic analysis of fusion hindrance
in heavy systems”, HAWAII 2014: Fourth Joint Meeting of the Nuclear Physics Divisions of the American
Physical Society and The Physical Society of Japan,(APS/JPS), Waikoloa, USA, Oct. (2014).
Washiyama K.: “Fusion hindrance in heavy systems withthe time-dependent energy density functional Theory”,
The International Symposium on Physics of Unstable
Nuclei 2014, (Institute for Nuclear Science and Technology), Ho Chi Minh City, Vietnam, Nov. (2014).
Washiyama K.: “Microscopic description of extra-pushenergy and fusion dynamics in heavy systems”, 22nd
ASRC International Workshop “Nuclear Fission and Exotic Nuclei”, (JAEA), Tokai, Japan, Dec. (2014).
Liang H.Z.: “Pseudospin symmetry in nuclear singleparticle spectra”, International Workshop: Intersectionof Cold-atomic and Nuclear Physics, (Asia Paciﬁc Center for Theoretical Physics), Pohang, South Korea, May(2014).
Liang H.Z.: “Nuclear Spin-Isospin Excitations — Towards
exotic deformed nuclei”, The 2nd Conference: Advancesin Radioactive Isotope Science, (RIKEN), Tokyo, Jun.
(2014).
Liang H.Z.: “Nuclear collective excitations in ﬁnite amplitude method”, Lectures on Covariant Density Functional Theory in Nuclear Physics, (Shandong University), Weihai, China, Jul. (2014).
Liang H.Z.: “Nuclear Spin-Isospin Excitations — Towards
exotic deformed nuclei”, The 21st International Sym-

posium on Spin Physics, (Peking University), Beijing,
China, Oct. (2014).
Liang H.Z.: “Nuclear Spin-Isospin Excitations — Towards
exotic deformed nuclei”, The 15th Chinese National
Conference on Nuclear Structure, (Guangxi Normal University), Guilin, China, Oct. (2014).
Liang H.Z.: “Solving Dirac equations in 3D coordinate
space”, International Workshop on Nuclear Science andSimulation in fundamental and applied researches, (Ton
DucThang University), Ho Chi Minh, Vietnam, Oct.
(2014).
Liang H.Z., Meng J., and Zhou S.-G.: “Hidden pseudospin
and spin symmetries in nuclei”, International Symposium on Physics of Unstable Nuclei, (Institute for Nuclear Science and Technology), Ho Chi Minh, Vietnam,
Nov. (2014).
Liang H.Z.: “Nuclear spin and isospin physics in spinisospin excitations and single-particle spectra”, Nuclear
Physics Seminar in Tsinghua University, (Tsinghua University), Beijing, China, Oct. (2014).
Liang H.Z.: “Dirac equation in 3D lattice and its application in covariant density functional theory”, Seminar in
Physics School, (Anhui University), Hefei, China, Mar.
(2015).
Liang H.Z.: “Supersymmetry and relativistic symmetry in’, Seminar in School of Physics, (Peking Univernuclei ’sity), Beijing, China, Apr. (2014).
’,
Liang H.Z.: “Solutions of Dirac equation in 3D lattice ’
Seminar in Institute of Theoretical Physics, (Chinese
Academy of Sciences), Beijing, China, Apr. (2014).
Sato K., Dobaczewski J., Nakatsukasa T., and Satu�la W.:“Isocranking calculation with proton-neutron mixed energy density functionals”, Fourth Joint Meeting of the
Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan (HAWAII 2014),(JPS, APS), Hawaii, Oct. (2014).
Sato K., Dobaczewski J., Nakatsukasa T., and Satu�laW.: “Mean-ﬁeld calculation based on proton-neutron
mixed energy density functionals”, 2nd Conference on
Advances in Radioactive Isotope Science (ARIS2014),(CNS, University of Tokyo), Tokyo, Jun. (2014).
(Domestic Conference)
中務孝: “原子核密度汎関数理論の概要”, サマースクール「クォークから超新星爆発まで」, (京都大学基礎物理学研
究所、計算基礎科学連携拠点、HPCI 戦略プログラム分野
5「物質と宇宙の起源と構造」), 京都, 7 月 (2014).
中務孝: “核励起と核反応の密度汎関数計算”, 「長寿命核分
裂核廃棄物の核変換データとその戦略」ワークショップ,(理研), 和光, 3 月 (2014).
小濱洋央, 飯田圭, 親松和浩, 小浦寛之: “変形核反応における全反応断面積の角度平均の取り方”, 日本物理学会第 70回年次大会, 東京, 3 月 (2015).
鷲山広平：“重い反応系における核融合阻害現象の微視的解析”，日本物理学会年次大会， (日本物理学会)， 東京， 3
月 (2015).

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Ⅶ. LIST OF PUBLICATIONS

Liang H.Z.: “Hidden pseudospin and spin symmetries innuclei ’’, RCNP Nuclear Physics Colloquium, (Osaka
University), Osaka, Dec. (2014).
佐藤弘一, Dobaczewski J., 中務孝, Satula W.: “陽子―中性子混合を含んだ密度汎関数計算”, 千葉大学原子核理論研究室セミナー, (千葉大学原子核理論研究室), 千葉, 5 月(2014).
佐藤 弘一, Dobaczewski J., 中務 孝, Satula W.: “Isospin
breaking term を入れた陽子―中性子混合密度汎関数計算”, 日本物理学会 第 70 回年次大会, (日本物理学会), 東
京, 3 月 (2015).

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Strangeness Nuclear Physics Laboratory
Publications[Journal](Original Papers)*Subject to Peer Review
Hiyama E., Ohnishi S., Gibson B., Rijken T.,“Three-body structure of the nn Λ system with ΛΝ- ΣΝ
coupling”, Physical Review C, 89, 061302(R) (2014). *Zhou B., Funaki Y., Tohsaki H., Horiuchi H., Ren Z.,“The container picture with two-alpha correlation for the
ground state of 12C”, Progress of Theoretical andExperimental Physics, 101D01(7pages) (2014). *Funaki Y., Yamada T., Hiyama E., Zhou B., Ikeda K.,“The container structure of alpha-alpha-Lambda
clusters in 9-Lambda-Beryrium”, Progress of Theoreticaland Experimental Physics, 113D01(16pages) (2014).	
 *Roepke G., Schuck P., Funaki Y., Horiuchi H., Ren Z.,
Tohsaki A., Yamada T., Zhou B.,“Nuclear clusters bound to doubly magic nuclei: Thecase of Po-212”. Physical Review C, 90, 034304 (2014). *Lyu M., Ren Z., Zhou B., Funaki Y., Horiuchi H., Roepke
G., Schuck P., Tohsaki A., Xu C., Yamada T.,“Investigation of 9Be from nonlocalized clustering
concept”, Physical Review C, 014313 (2015). *Homma H., Isaka M., Kimura M.,“Parity reversal of 12LambdaBe”, Physical Review C, 91,
014314 (2015). *Sakumichi N., Suganuma H.,“Perfect Abelian dominance of quark confinement in
SU(3) QCD”, Physical Review D (Rapid
communication), 90, 111501 (2014). *Ikeda T.N., Sakumichi N., Polkovnikov A.,Ueda M.,“The second law of thermodynamics under unitaryevolution and external operations”, Annals of Physics,
354, 338 (2015). *Lu BN., Hiyama E., Sagawa H., Zhou SG.,“Superdeformed Λ hypernuclei within relativistic mean
field models”, Physical Review C, 89, 044307 (2014). *Hiyama E., Kamimura M.,“Universality in Efimov-associated tetramers in 4He”,
Physical Review A, 90, 052514 (2014). *Schulze HJ., Hiyama E.,“Skyrme force for light and heavy hypernuclei”, PhysicalReview C, 90, 047301 (2014). *Hu J., Hiyama E.,Toki H.,“Effective ΛN potential from relativistic
Brueckner-Hartree-Fock theory”, Physical Review C, 90,014309 (2014). *Suno H., Esry BD.,
“Cold elastic and reactive atom-molecule collisions inhelium-helium-alkali-metal triatomic systems”, PhysicalReview A, 89, 052701 (2014). *Suno H., Suzuki Y., Descouvemont P.,“Triple-α continuum structure and Hoyle resonance of
12C using the hyperspherical slow variable
discretization”, Physical Review C, 91, 014004 (2015).
[Book · Proceedings](Others)*Subject to Peer Review
Isaka M.,
“Studies of hypernuclei with the AMD method”, Chiral
Symmetry in Hadrons and Nuclei, 53-56 (2014).
Isaka M.,
“Structure of p-sd shell Lambda hypernuclei studied
with AMD”, Journal of Physics: Conference Series, 569,
012083 (2014
Ohnishi S., Ikeda Y., Hyodo T., Hiyama E., Weise W.,“K-d ->πΣn reactions and structure of the Λ(1405)”,
Journal of Physics: Conference Series, 569, 012077(2014).	
 *Togashi H., Takehara Y., Yamamuro S., Nakazato K.,
Suzuki H., Sumiyoshi K., Takano M.,“Equation of state for nuclear matter in core-collapse
supernovae by the variational method”, Journal of
Physics: Conference Series, 569, 012058 (2014).	
 *	
 Togashi H., Takehara Y., Yamamuro S., Nakazato K.,
Suzuki H., Sumiyoshi K., Takano M.,“Nuclear equation of state for core-collapse supernovae
with realistic nuclear forces”, Proceedings of Science,
PoS (NIC XIII) 169 (2015).	
 *	
 Kikuchi Y., Myo T., Kato K., Ikeda K.,“Mechanism of Coulomb breakup reactions of
two-neutron halo nuclei 6He and 11Li”, Journal of
Physics: Conference Series, 569, 012034 (2014). *	 Oral Presentations(International Conference etc.)
Hiyama E.,“Structure of light hypernuclei”, Sixth Asia-PacificConference on Few-Body Problems in Physics APFB
2014, Hahndorf, Australia, Apr.(2014).
Hiyama E.,“Structure of light Lambda hypernuclei by (e, e’K+)
reaction”, JLab Workshop on hypernuclear physics“Perspectivesofhighresolution
hypernuclear
spectroscopy at Jlab”, Newport News, VA, USA, May(2014).
Hiyama E.,“Structure of α clustering Λ hypernuclei”, 3rdInternational Workshop on “State of the Art in Nuclear
Cluster Physics” (SOTANCP3), Yokohama, May(2014).
Hiyama E.,“Few-body aspects of hypernuclear physics”, Present
Status of the Nuclear Interaction Theory, Beijing,
China, Aug. (2014).
Hiyama E.,“Structure of neutron-rich Lambda hypernuclei”,
SPHERE MEETING 2014, Prague, Czech, Sep. (2014).
Hiyama E.,“Three- and four-body structure of 4He trimer andtetramer system”, 11th Asian International Seminar on
Atomic and Molecular Physics (AISAMP11), Sendai,
Japan, Oct. (2014).
Hiyama E.,“Structure of few-body hypernuclei”, Fourth Joint- 455 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Meeting of the Nuclear Physics Divisions of theAmerican Physical Society and The Physical Society ofJapan (HAWAII 2014), Waikoloa, Hawaii, USA, Oct.
(2014).
Hiyama E.,“Structure of neutron-rich hypernuclei”, Critical
Stability 2014, Santos, Brazil, Oct. (2014).
Hiyama E.,“Structure of neutron rich hypernuclei”, Achievements
and Perspectives in Low-Energy QCD with Strangeness,
ECT*, Trento, Italy, Oct. (2014).
Hiyama E.,“Structure of neutron-rich Lambda hypernuclei”,
FUSTIPEN Workshop “New Directions for Nuclear
Structure and Reaction Theories”, CAEN, France, Mar.
(2015).
Funaki Y.,“Alpha condensates and nonlocalized cluster structures”,
The 3rd International Workshop on “State of the Art in
Nuclear Cluster Physics (SOTANCP3)”, Yokohama,Japan, May (2014).
Funaki Y.,“Alpha condensates and nonlocalized cluster structures”,
International Workshop on “Multi facets of Eos andClustering (IWM-EC 2014)”, Catania, Italy, May (2014).
Funaki Y.,“Cluster states and container picture in light nuclei, andtriple-alpha reaction rate”, Nuba conference Series-1:
Nuclear Physics and Astrophysics, Antalya, Turkey, Sep.
(2014).
Isaka M.,
“Structure of Lambda hypernuclei with theantisymmetrized molecular dynamics method”, Sixth
Asia-Pacific Conference on Few-Body Problems in
Physics (APFB 2014), Hahndorf, Australia, Apr. (2014).
Isaka M.,
“Deformations of sd and pf shell Lambda hypernuclei
with antisymmetrized molecular dynamics”, JLabWorkshop on hypernuclear physics “Perspectives ofhigh resolution hypernuclear spectroscopy at Jlab”,
Newport News, VA, USA, May (2014).
Isaka M.,
“Structure of p-sd shell Lambda hypernuclei studied
with AMD”, 3rd International Workshop on “State of
the Art in Nuclear Cluster Physics” (SOTANCP3),
Yokohama, May(2014).
Isaka M., Homma H., Kimura M.,“Structure of single Lambda Hypernuclei”, International
workshop on 'Future prospect in nuclear physics withstrangeness at J-PARC', Wako, Japan, June(2014).
Isaka M.,
“Structure of p-sd shell Lambda hypernuclei with
antisymmetrized molecular dynamics”, The SPHERE
Meeting 2014, Prague, Czech, Sep. (2014).
Isaka M.,
“StructureofLambdaHypernuclei
withAntisymmetrized Molecular Dynamics”, Fourth Joint

Meeting of the Nuclear Physics Divisions of theAmerican Physical Society and The Physical Society ofJapan (HAWAII 2014), Waikoloa, Hawaii, USA, Oct.
(2014).
Isaka M., Kimura M., Hiyama E., Sagawa H.,“Superdeformed
statesin
hypernuclei
withantisymmetrized molecular dynamics”, Fourth Joint
Meeting of the Nuclear Physics Divisions of theAmerican Physical Society and The Physical Society ofJapan (HAWAII 2014), Waikoloa, Hawaii, USA, Oct.
(2014).
Isaka M.,
“Superdeformed
statesin
hypernuclei
withantisymmetrized molecular dynamics”, StrangenessNuclear Physics 2014, Changsha, China, Dec. (2014).
Isaka M.,
“Triaxial
deformationof
27LambdaMg
withantisymmetrized molecular dynamics”, International
workshopon'Hypernuclear
physics
withElectromagnetic Probes', Wako, Japan, Jan. (2015).
Ohnishi S., Ikeda Y., Hyodo T., Hiyama E., Weise W.,“K-d scattering and structure of Λ(1405)”, Sixth
Asia-Pacific Conference on Few-Body Problems in
Physics (APFB2014), Hahndorf, Australia, Apr. (2014).
Ohnishi S., Ikeda Y., Hyodo T., Hiyama E., Weise W.,“K- scattering on deuteron target and structure of Λ
(1405)”, 3rd International Workshop on “State of the Art
in Nuclear Cluster Physics" (SOTANCP3), Yokohama,Japan, May(2014).
Ohnishi S., Ikeda Y., Hyodo T., Hiyama E., Weise W.,“ Λ (1405) resonance in K-d scattering reaction”,
International Conference on Exotic Atoms and Related
Topics (EXA2014), Wien, Austria, Sep. (2014).
Togashi H., Takehara Y., Yamamuro S., Nakazato K.,
Suzuki H., Sumiyoshi K., Takano M.,“Equation of state for nuclear matter in core-collapse
supernovae by the variational method”, 3rdInternational Workshop on “State of the Art in Nuclear
Cluster Physics" (SOTANCP3), Yokohama, Japan,
May(2014).
Togashi H., Takehara Y., Yamamuro S., Nakazato K.,
Suzuki H., Sumiyoshi K., Takano M.,“Variational study of the supernova equation of statewith realistic nuclear forces”, Fourth Joint Meeting of
the Nuclear Physics Divisions of the American PhysicalSociety and The Physical Society of Japan (HAWAII2014), Waikoloa, Hawaii, USA, Oct. (2014).
Togashi H., Hiyama E., Takano M., Yamamoto Y.,“Cluster variational method for nuclear matter withhyperons”, Strangeness Nuclear Physics 2014,
Changsha, China, Dec. (2014).
Togashi H., Hiyama E., Takano M., Yamamoto Y.,“Equation of state for hyperonic nuclear matter with thecluster variational method”, HPCI and iTHES
workshop on "Study of Neutron stars and Core-Collapse
Supernovae", Wako, Japan, Dec. (2014).
Togashi H., Hiyama E., Takano M., Yamamoto Y.,- 456 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)“Variational study of nuclear equation of state forcore-collapse supernovae and hyperonic neutron stars”,
International Workshop on NEUTRINO PHYSICS andASTROPHYSICS, Istanbul, Turkey, March(2015).
Maeda S., Yokota A., Hiyama E., Oka M., Liu YR.,
Fukukawa K.,“Scattering length of YcN 2 body potential
andLambda_c NN 3 body calculation with angularmomentum”, Fourth Joint Meeting of the Nuclear
Physics Divisions of the American Physical Society and
The Physical Society of Japan (HAWAII 2014),
Waikoloa, Hawaii, USA, Oct. (2014).
Yoshida T., Oka M., Hosaka A., Hiyama E., Sadato K.,“P-wave heavy baryons with the constituent quark
model”, Fourth Joint Meeting of the Nuclear Physics
Divisions of the American Physical Society and The
Physical Society of Japan (HAWAII 2014), Waikoloa,
Hawaii, USA, Oct. (2014).
Yoshida T., Oka M., Hosaka A., Hiyama E., Sadato K.,“Charmed baryon with constituent quark model”,
Workshop "Charm Hadron and Nuclear Physics", Tokyo,
Japan, Nov. (2014).
Yoshida T., Oka M., Hosaka A., Hiyama E., Sadato K.,“Charmed baryon spectroscopy in a quark model”, Mini
workshop on "Structure and productions of charmed
baryonsⅡ", Ibaraki, Tokai, Japan, Aug. (2014).
(Domestic Conference)
肥山詠美子: “変分法の一般論と無限小変位ガウスローブ基
底関数展開法,	 	
 少数核子系、及び不安定核物理への応用,	
 ハドロン物理への応用,	
 	
 ハイパー核物理の応用と J-PARCを視野に入れた将来の展望”, 少数多体系物理の最前線,	
 大阪,	
 11 月(2014).	
 肥山詠美子: “ミクロな世界の 3 体・4 体問題へのいざない”,	
 理化学研究所	
 科学講演会 2014,	
 東京, 11 月 (2014).
肥山詠美子: “厳密少数多体系計算法の確立とその展開”,
第 922 回九大原子核セミナー,	
 福岡, 1 月(2015).
井坂政裕: “ＡＭＤ，ｈｙｐｅｒ核理論	
 ～ＡＭＤによるハイパー核の構造研究～”, ストレンジネスを含む原子核に関わる研究会	
 ‐‐課題と挑戦‐‐, 和光, 6 月(2014).
井坂政裕, 福川賢治,	
 木村真明,	
 肥山詠美子,	
 佐川弘幸,	
 山
本安夫: “反対称化分子動力学よるＡ～４０	
 のΛハイパー核の超変形状態”, ダブルストレンジネス核物理研究会,	
 	
 
岐阜,	
 9 月(2014).
井坂政裕: “ＡＭＤ	 による	
 ｓｄ-ｐｆ	 殻Λハイパー核の変形状態の研究”, 「ストレンジネスを含む原子核の最近の展
開」研究会, 静岡, 9 月(2014).
井坂政裕, 木村真明,	
 肥山詠美子,	
 佐川弘幸: “AMD による Ar
ハイパー核の超変形状態の研究”,	
 日本物理学会 第 70回年次大会(2015 年), 東京, 3 月(2015).
大 西 祥 太 , 池 田 陽 一 ,	  兵 藤 哲 雄 ,	  肥 山 詠 美 子 ,	  Wolfram	
 Weise: “3 体散乱方程式に基づく Lambda(1405)共鳴生成反応の研究”, ELPH	
 研究会 C009「光生成反応によるハドロン
間相互作用の研究の進展」, 仙台, 11 月(2014).
富樫甫, 肥山詠美子,	
 鷹野正利: “変分法によるハイペロン
物質状態方程式の研究”, 「ストレンジネスを含む原子核の最近の展開」研究会, 静岡, 9 月(2014).
富樫甫, 肥山詠美子,	
 鷹野正利,	
 山本安夫: “変分法によるハイペロン混合を考慮した核物質状態方程式”, 新学術
領域研究会「中性子星核物質」,	
 京都,	
 3 月(2015).
富樫甫, 肥山詠美子,	
 鷹野正利,	
 山本安夫: “一様ハイペロ
ン物質に対するクラスター変分法の研究”, 日本物理学会
第 70 回年次大会(2015 年), 東京, 3 月(2015).
数納広哉, 作道直幸, 肥山詠美子: “超球座標を用いた２次元
ヘリウム原子３体系の理論研究”, 日本物理学会 2014 年
秋季大会, 春日井, 9 月(2014).
山 中 長 閑 : “Nuclear electric dipole moment of 3-bodysystems in the Gaussian expansion method”, KEK 研究
会「Flavor of New Physics」,	
 東海村,	 3 月(2015).
山 中 長 閑 : “Nuclear electric dipole moment of 3-bodysystems in the Gaussian expansion method”, RIBF
Seminar, 和光, 3 月(2015).
山 中 長 閑 : “Nuclear electric dipole moment of 3-bodysystems in the Gaussian expansion method”, 日本物理学会 第 70 回年次大会(2015 年), 東京, 3 月(2015).
吉田哲也, 岡真,	 保坂淳,	
 肥山詠美子,	
 定藤克法: “P-wave
heavy baryons in the constituent quark model”, Hadron
Spectroscopy Café	 (東京工業大学), 東京, 5 月(2014).
吉田哲也, 岡真,	 保坂淳,	
 肥山詠美子,	
 定藤克法: “チャームバリオンのスペクトルとその構造の研究”,	
  「ストレンジネスを含む原子核の最近の展開」研究会, 静岡, 9 月(2014).

- 457 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONSMathematical Physics Laboratory
Publications[Journal]（Original Papers） *Subject to Peer Review
Kimura T., Murata M.: “Current Reﬂection and Transmission at Conformal Defects: Applying BCFT to
Transport Process”, Nucl. Phys. B885, 266-279 (2014).
＊
Shitade A., Kimura T.: “Bulk Angular Momentum andHall Viscosity in Chiral Superconductors”, Phys.Rev.
B90, 134510 (2014). ＊Kimura T.: “Note on a duality of topological branes”,
Prog. Theor. Exp. Phys. 2014, 103B04 (2014). ＊Kimura T.: “Hofstadter problem in higher dimensions”,
Prog. Theor. Exp. Phys. 2014, 103B05 (2014). ＊Kimura T.: “Duality and integrability of a supermatrix
model with an external source”, Prog. Theor. Exp.
Phys. 2014, 123A01 (2014). ＊Hashimoto K.: “Possibility of ferromagnetic neutron matter”, Phys.Rev. D91, 085013 (2015). ＊Inami T., Koyama Y., Nakayama Y., Suzuki M.: “Is cosmological constant screened in Liouville gravity withmatter? ”, Prog. Theor. Exp. Phys. 2015, 053B05(2015). ＊Hashimoto K., Kharzeev D.: “Entropic destruction ofheavy quarkonium in non-Abelian plasma from holography”, Phys. Rev. D90, 125012 (2014). ＊Hashimoto K., Kinoshita S., Murata K., Oka T.: “Turbulent meson condensation in quark deconﬁnement”, Phys.
Lett. B746, 311-314 (2015). ＊Hashimoto K., Kinoshita S., Murata K., Oka T.: “Electric
Field Quench in AdS/CFT”, JHEP 1409, 126 (2014).
＊
Mazumdar A., Noumi T., Yamaguchi M.: “Dynamical
breaking of shift-symmetry in supergravity-based inﬂation”, Phys. Rev. D90, 043519 (2014) ＊Hashimoto K., Oka T., Sonoda A.: “Magnetic instability in AdS/CFT: Schwinger eﬀect and Euler-Heisenberg
Lagrangian of supersymmetric QCD”, JHEP 1406, 085(2014). ＊Nov. (2014).
Kimura T., “Introduction to ABJM theory”, S?minairede Laboratoire de Physique Theorique d’Orsay, (Laboratoire de Physique Theorique d’Orsay, Universit? deParis-Sud), オルセー, フランス, Jan. (2015).
木村太郎 : “ランダム行列のお話”, 在仏若手研究者交流セミナー, (フランス 在仏若手研究者有志), パリ, Jan. (2015).
Kimura T.: “ゼータ関数の統計力学と深リーマン予想 ”, 2nd
Cross-disciplinary Meeting of Japanese Young Scientists
in Europe, (在欧若手日本人研究者有志), リューデスハイ
ム、ドイツ, Jul. (2014).
Hashimoto K.: “Electric quench in holography”, APCTP
focus week on holography, (APCTP), Pohang, Korea,
July (2014).
Hashimoto K.: “Turbulent meson condensation at quark
deconﬁnement”, Workshop on strong dynamics beyond
QCD from the lattice and string theory (NCTS Taiwan),
Shinchu, Taiwan, Dec. (2014).
Hashimoto K.: “Turbulent meson condensation at quark
deconﬁnement”, KEK 理 論 研 究 会 (KEK), Tsukuba,
Japan, Jan. (2015).
Hashimoto K.: “Hadron and string theory”, NEW
HADRON PHYSICS SYMPOSIUM, (Nagoya university), Nagoya, Japan, Apr. (2014).
(Domestic Conference)
木下俊一郎, 村田佳樹, 橋本幸士, 岡隆史, “ホログラフィック
QCD における時間依存電場への応答”, 日本物理学会, 佐賀大学, 9 月 (2014).
木下俊一郎, 村田佳樹, 橋本幸士, 岡隆史, “強相関絶縁体におけるシュィンガー機構の実現とゲージ重力対応による理論の比較”, 日本物理学会, 早稲田大学, 3 月 (2015).
木下俊一郎, 村田佳樹, 橋本幸士, 岡隆史, “Turbulent mesoncondensation in quark deconﬁnement”, 日本物理学会, 早稲田大学, 3 月 (2015).
山口康宏, 小川軌明, 橋本幸士, “ホログラフィック模型による
重クォーコニウム・スペクトラムとスピン縮退”, 日本物理学会, 早稲田大学, 3 月 (2015).
橋 本 幸 士, 杉 下 宗 太 郎, 寺 嶋 靖 治, “Ramond-Ramondcouplings of D-branes”, 日本物理学会, 早稲田大学, 3 月(2015).

Oral Presentations(International Conference etc.)
Kimura T., “Towards U (N |M ) knot invariant from ABJM
theory”, 6th Bethe Center Workshop: Topological
String and Applications, (Bethe Center for Theoretical Physics, Physikalisches Institut, Universität Bonn),
Bonn, Germany, Oct. (2014).
Kimura T., “Wilson loop as a source in matrix model”,
チェコ科学アカデミー物理学教室セミナー, (チェコ チェコ
科学アカデミー物理学教室), プラハ, チェコ, Oct. (2014).
Kimura T., “FQH/CFT and its deformation” Universityof Crete HEP seminar, (Crete Center for Theoretical
Physics, University of Crete), イラクリオン，ギリシャ,- 458 -

1

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)√
at sN N =200 GeV”, Phys. Rev. C 91, 014907 (2015).
*
Adare A., et al. PHENIX Collaboration, “Charged-pioncross sections and double-helicity asymmetries in polar√
ized p+p collisions at s = 200 GeV”, Phys. Rev. D
91, 032001 (2015). *Adare A., et al. PHENIX Collaboration, “Measurement of
the Upsilon(1S+2S+3S) production in p+p and Au+Au√
collisions at sN N = 200 GeV”, Phys. Rev. C 91,
024913 (2015). *Adare A., et al. PHENIX Collaboration, “Search for dark
photons from neutral meson decays in p+p and d+Au√
collisions at sN N = 200 GeV”, Phys. Rev. C 91,
031901 (2015). *Seidel R, PHENIX W to mu measurements in polarized proton-proton collisions, PoS DIS2014(2014) 205,
2014/07/16
Kanesue T, Fuwa Y, Kondo K, Okamura M, ”Laser ion
source with solenoid ﬁeld”, APPLIED PHYSICS LETTERS, 105, 193506 (2014) *Okamura M, Sekine M, Ikeda S, Kanesue T, Kumaki M, Fuwa Y, ”Preliminary result of rapid
solenoid for controlling heavy-ion beam parametersof laser ion source”, Laser and Particle Beams,
doi:10.1017/S026303461500004X (2015) *Radiation Laboratory
Publications[Journal](Original Papers) *Subject to Peer Review
Adare A., et al. PHENIX Collaboration, “Heavy-ﬂavor
electron-muon correlations in p+p and d+Au collisions√
at s = 200 GeV”, Phys. Rev. C 89, 034915 (2015). *Adler S. S., et al. PHENIX Collaboration, “Transverseenergy distributions at midrapidity in p+p, d+Au, and√
Au+Au collisions at sN N =62.4 - 200 GeV and implications for particle-production models”, Phys. Rev. C
89, 044805 (2014). *Adare A., et al. PHENIX Collaboration, “Azimuthalangle dependence of charged-pion-interferometry measurements with respect to 2nd and 3rd-order event plane√in Au+Au collisions at sN N = 200 GeV”, Phys. Rev.
Lett. 112, 222301 (2014). *Adare A., et al. PHENIX Collaboration, “Cold nuclearmatter eﬀects on heavy-quark production at forward and√backward rapidities in d+Au collisions at sN N =200
GeV”, Phys. Rev. Lett. 112, 252301 (2014). *Adare A., et al. PHENIX Collaboration, “Measurement oftransverse-single-spin asymmetries for midrapidity andforward-rapidity production of hadrons in polarized p+p√
collisions at s = 200 and 62 GeV”, Phys. Rev. D 90,
012006 (2014). *Adare A., et al. PHENIX Collaboration, “Inclusive
Double-Helicity Asymmetries in Neutral-Pion and Eta√
Meson Production in p+p Collisions at s = 200 GeV”,
Phys. Rev. D 90, 012007 (2014). *Adare A., et al. PHENIX Collaboration, “System-size dependence of open-heavy-ﬂavor production in nucleus√
nucleus collisions at sN N =200 GeV”, Phys. Rev. C
90, 034903 (2014). *Adare A., et al. PHENIX Collaboration, “Centrality Categorization for Rp (d) + A in high-energy collisions”,
Phys. Rev. C 90, 034902 (2014). *Adare A., et al. PHENIX Collaboration, “Low-Mass
Vector-Mesons Production at forward rapidity in p+p√
Collisions at s = 200 GeV”, Phys. Rev. D 90, 052002(2014). *Adare A., et al. PHENIX Collaboration, “Cross Section
and Transverse Single-Spin Asymmetry of η Mesons in√p↑ + p collisions at s = 200 GeV at Forward Rapidity”,
Phys. Rev. D 90, 072008 (2014). *Adare A., et al. PHENIX Collaboration, “Measurementof K 0S and K ∗0 in p+p, d+Au and Cu+Cu collisions at√
sN N = 200 GeV”, Phys. Rev. C 90, 054905 (2014). *Adare A., et al. PHENIX Collaboration, “Nuclear mattereﬀects on J/psi production in asymmetric Cu+Au col√lisions at sN N =200GeV”, Phys. Rev. C 90, 064908(2014). *Adare A., et al. PHENIX Collaboration, “Cross-section
for barb production via dielectrons in d+Au collisions(Review) *Subject to Peer Review
Akiba Y, ”Quest for the quark-gluon plasma — hard andelectromagnetic probles”, Progress of theoretical and experimental physics 03A105(2015), 2015/01/12 *[Book・Proceedings](Original Papers)
Kanesue T, et al. ”THE COMMISSIONING OF THE
LASER ION SOURCE FOR RHIC EBIS”, Proceedingsof IPAC 2014 (ISBN 978-3-95450-132-8), p1890-1892
Munemoto N, et al., ”LASER ABLATION ION SOURCEFOR THE KEK DIGITAL ACCELERATOR”, Proceedings of IPAC 2014 (ISBN 978-3-95450-132-8), p598600
Ikeda S, et al., ”Control of Plasma Flux with Pulsed
Solenoid for Laser Ion Source”, Proceedings of IPAC
2014, (ISBN 978-3-95450-132-8), p601-603
Fuwa Y, et al., ”Beam dynamics of multi charge state ionsin RFQ linac”, Proceedings of LINAC 2014 (ISBN 9783-95450-142-7), p317-319
Okamura M, et al., ”Low Charge Laser Ion Source for the
EBIS injector”, Proceedings of LINAC 2014 (ISBN 9783-95450-142-7), p64-66(Review)
秋葉康之, クォーク・グルーオン・プラズマの物理 (共立出版), ISBN 978-4-320-03523-2, 2014/4/15

Oral Presentations(International Conference etc.)- 459 -

1

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Yasuyuki Akiba, ”Future plan at BNL”, Hadron physics
symposium (科研費新学術領域「新ハドロン」), Nagoya,Japan, 2014/4/18
Yasuyuki Akiba, ”Electromagnetic probes and heavy ﬂavor from RHIC and LHC”, Hawaii 2014 (Fourth Joint
Meeting of the Nuclear Physics Division of the American Physical Society and the Physical Society of Japan)(APS/JPS), Waikoloa Village, HI, USA, 2014/10/7
Ralf Seidl, ”W to mu measurements at PHENIX”, Conference on Deep inelastic scattering and related topics ,Warsaw, Poland, 2014/05/29
Ralf Seidl, ”Three-Dimensional Imaging and Spin - from
Valence Quarks to the Sea”, Hawaii 2014 (Fourth Joint
Meeting of the Nuclear Physics Division of the American Physical Society and the Physical Society of Japan)(APS/JPS), Waikoloa Village, HI, USA, 2014/10/7
T. Kanesue, ”THE COMMISSIONING OF THE LASERION SOURCE FOR RHIC EBIS”, 5th International
Particle Accelerator Conference (Cockcroft Inst. and
U. Liverpool), Dresden, Germany, 2014/06/15-16
Y. Fuwa, ”Charge-State Selective Ion Beam Acceleration with RFQ Linac”, 20th International Symposium
on Heavy-Ion Inertial Fusion (IMP), Lanzhou, China,
2014/08/11-15
T. Kanesue, ”Stable operation of Laser Ion Source for low
charge state ion production”, 20th International Symposium on Heavy-Ion Inertial Fusion (IMP), Lanzhou,
China, 2014/08/11-15
Shunsuke Ikeda, ”Control of plasma ﬂux with pulsedsolenoid for laser ion source”, 5th International Particle
Accelerator Conference (Cockcroft Inst. and U. Liverpool), Dresden, Germany, 2014/06/15-16
N. Munemoto, ”LASER ABLATION ION SOURCE FOR
THE KEK DIGITAL ACCELERATOR”, 5th International Particle Accelerator Conference (Cockcroft Inst.
and U. Liverpool), Dresden Germany, 2014/06/15-20
M. Okamura, ”Preliminary result of rapid solenoid for controlling heavy-ion beam parameters of laser ion source”,
20th International Symposium on Heavy-Ion Inertial Fusion (IMP), Lanzhou, China, 2014/08/11-15
Y. Fuwa, ”Beam dynamics of multi charge state ionsin RFQ linac”, 27th Linear Accelerator Conference(CERN), Geneva, Switzerland, 2014/08/31-09/05
M. Okamura, ”Low Charge Laser Ion Source for the EBIS
injector”, 27th Linear Accelerator Conference (CERN),
Geneva, Switzerland, 2014/08/31-09/05
Shunsuke Ikeda, ”Inﬂuence of solenoidal magnetic ﬁeld on
laser ablation plasma”, 5th Euro-Asian Pulsed Power
Conference (Kumamoto Univ.), Kumamoto, Japan,
2014/09/11
Masafumi Kumaki, ”Proton beam generation using Aucoated plastic target from Laser Ion Source” 19th International Conference on Ion Beam Modiﬁcation of Materials, Leuven, Belgium, 2014/09/14-19
Yusuke Komatsu, ”Development of a Tracking and Elec-tron Identiﬁcation System Using GEM for the J-PARC
E16 Experiment”, IEEE NUCLEAR SCIENCE SYMPOSIUM 2014 (IEEE), Seattle, USA, 2014/11/08-15
Satoshi Yokkaichi, ”Measurement of vector mesons in
nuclei at J-PARC E16 experiment” , Hadrons andHadron Interactions in QCD 2015 (YITP), Kyoto, Japan
2015/03/05(Domestic Conference etc.)
Ralf Seidl, ”Experimental overview: Nucleon spin structure” , APS Division of Nuclear Physics (APS) Temple
University, Philadelphia, PA, USA 2014/9/13,
Ralf Seidl, ”Belle 実験における di-hadron の破砕関数”, 日本
物理学会第 70 回年次大会早稲田大学、東京, 2015/3/21-24
秋葉康之, ”RHIC PHENIX 実験とその将来計画”, 第１回
CiRfSE ワークショップ (筑波大学数理物質融合科学センター), 筑波大学、つくば市, 2015/3/12
Kotaro KONDO 大電流レーザーイオン源にむけた重金属
標的を用いたレーザーアブレーションプラズマの価数
分析日本原子力学会 2014 年秋の大会京都大学、京都
2014/09/08-10
池田峻輔, ” レーザーアブレーションプラズマに対するパルス磁場の影響”, 日本物理学会第 70 回年次大会, 早稲田大
学、東京, 2015/3/21-24
熊木雅史” ピコ秒レーザーを用いたレーザーイオン源開発” 日 本 物 理 学 会 第 70 回 年 次 大 会 早 稲 田 大 学 、東 京
2015/3/21-24
村 上 ひ か り, ”チェレ ン コ フ 検 出 器 用 CsI GEM の 開 発”,
第 11 回 MPGD 研 究 会 (東 北 大 学), 東 北 大 学 、仙 台,
2014/12/20
中井 恒, ”J-PARC E16 実験における GEM 検出器の開発
状況”, 第 11 回 MPGD 研究会 (東北大学), 東北大学、仙台, 2014/12/20- 460 -

2

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Advanced Meson Science Laboratory[Journal]

Publications

Abdel-Jawad M., Watanabe I., Tajima N., Ishii Y., andKato R., “Universality Class of the Mott-Hubbard
Transition”, Phys. Rev. Lett. 114, 106401-1-5 (2015).
Adam N., Suprayoga E., Adiperdana B., Guo H., Tanida K.,
Mohd-Tajudin S.S., Kobayashi R., Sera M., Nishioka T.,
Matsumura M., Sulaiman S., Mohamed Ibrahim M.I.,
and Watanabe I, "Muon sites in Ce(Ru,Rh)2Al10
investigated by using Density Functional Theory fromthe view point of electronic potential" J. Phys. Conf. Ser.
551, 012053 (2014).
Adare A., Ohnishi H. et al. (PHENIX Collaboration)“Measurement of K0S and K∗0 in p+p, d+Au, and Cu+Cu
collisions at √SNN=200 GeV”, Phys. Rev. C90 (2014) 5,054905Adare A., Ohnishi H. et al. (PHENIX Collaboration)“System-size dependence of open-heavy-flavor
production in nucleus-nucleus collisions at √SNN=200
GeV”,Phys.Rev. C90 (2014) 034903
Adiperdana B., Suprayoga E., Adam N.,
Mohm-Tajudin S.S., Rozlan A.F., Sulaiman S.,
Mohamed-Ibrahim M.I., Kawamata T., Adachi T.,
Dharmawan I.A. , Siregar R.E., Koike Y., and Watanabe
I., "An Effect of the Super-Cell Calculation on Muon
Positions and Local Deformations of Crystal Structurein La2CuO4", J. Phys. Conf. Ser. 551, 012051 (2014).
Adler S.S., Ohnishi H. et al. (PHENIX Collaboration)“Transverse-energy distributions at midrapidity in
p+p , d+Au , and Au+Au collisions at√SNN= 62.4–200
GeV and implications for particle-production models”,
Phys.Rev. C89 (2014) 044905
Agnello H., Outa H., FINUDA collaboration, "First
determination of the one-proton induced Non-Mesonic
Weak Decay width of p-shell Λ-Hypernuclei", Phys. Lett.
B738 (2014) 499-504*
Ariga H., Shimomura K., Ishida K., Pratt F., Yoshizawa,
Wataru K., Higemoto W., Torikai E., Asakura K.,“Detection of Oxygen Vacancy in Rutile TiO2 Single
Crystal by µSR Measurement”, JPS Conference
Proceedings (2014) 010307
Bakule P., Sukhorukov O., Ishida K., Pratt F., Fleming D.,
Momose T., Matsuda Y., and Torikai E., "First accurate
experimental study of Mu reactivity from astate-selected reactant in the gas phase: the Mu + H2{1}reaction rate at 300 K", J. Phys. B: At. Mol. Opt. Phys.
48 (2015) 045204
Bazzi M., Iwasaki M., SIDDHARTA collaboration,"L-series X-ray yields of kaonic 3He and 4He atoms ingaseous targets", Eur. Phys. J. A50 (2014) 91*
Beer G.A., Fujiwara Y., Hirota S., Ishida K., Iwasaki M.,
Kanda S., Kawai H., Kawamura N., Kitamura R., Lee S.,
Lee W., Marshall G.M., Mibe T., Miyake Y., Okada S.,
Olchanski K., Olin A., Ohnishi H., Oishi Y., Otani M.,
Saito N., Shimomura K., Strasser P., Tabata M., TomonoD., Ueno K., Won E., and Yokoyama K., "Enhancementof Muonium Emission Rate from Silica Aerogel with aLaser-Ablated Surface", Prog. Theor. Exp. Phys. 091C01(2014).
Cargnello M., Iwasaki M., SIDDHARTA collaboration,"X-ray spectroscopy of kaonic atoms at SIDDHARTA",
EPJ Web Conf. 73 (2014) 05008*
Chang L. –J., Lees M.R., Watanabe I., Hillier A.D., Yasui
Y., and Onoda S., “Static Magnetic Moments Revealed
by Muon Spin Relaxation and Thermodynamic
Measurements in Quantum Spin Ice Yb2Ti2O7”,
Phys. Rev. B 89, 184416-1-5 (2014)*
Curceanu C., Iwasaki M., Okada S. et al. (SIDDHARTA
Collaborarion), “ Unveiling the strangeness secrets:
low-energy kaon-nucleon/nuclei interactions studies at
DAΦNE”, EPJ Web Conf. 66 (2014) 09004
Enomoto S., Hashimoto T., Itahashi K., Iwasaki M., Ma. Y.,
Okada S., Ohnishi H., Outa H., Sakuma. F., Sato M.,
Tokuda M., Yamazaki T. (J-PARC E15 collaboration),"Search for deeply-bound Kbar-nuclear states via the
3He(inflight-K-,n) reaction at J-PARC", Proceedingsof XV International Conference on Hadron
Spectroscopy (Hadron 2013), Proceedings of Science(Hadron 2013) 182 (2014)
Funamori N., Kojima K.M., Wakabayashi D., Sato T.,
Taniguchi T,, Nishiyama N., Irifune T., Tomono D.,
Matsuzaki T., Miyazaki M., Hiraishi M., Koda A., andKadono R.,“Muonium in Stishovite: Implications for
the Possible Existence of Neutral Atomic Hydrogen in
the Earth’s Deep Mantle”, Scientific Report 5, 8437-1-5(2015).
Fujihala M., Xu-Guang Zheng, Norodomi H., Kawae T.,
Matsuo
A.,
Kindo
K.,
and
Watanabe
I.,"Unconventional Spin Freezing in the Highly
Two-Dimensional Spin-1/2 Kagome Antiferromagnet
Cd2Cu3(OH)6(SO4)2・4H2O: Evidence of Partial Orderand Coexisting Spin Singlet State on a Distorted
Kagome Lattice", Phys. Rev. B 89, 100401(R)-1-5(2014)*
Fujioka H., Brinkmann K.T., Friedrich S.,
GeisselH.,Hayano R.S., Hirenzaki S., Itahashi K., Itoh S., JidoD., Metag V., Nagahiro H., Nanova M., Nishi T., OkochiK., Outa H., Suzuki K., Suzuki T.,Tanaka Y.K.,
Watanabe Y.N., Weick H., "Spectroscopy of eta-prime
Mesic Nuclei via Semi-Exclusive Measurement at
FAIR",EPJ Web Conf. 66 (2014) 09006
Goto T., Suzuki T., Watanabe I., Manaka H., Luetkens H.,
and Amato A., "Ground State of Bond-Disordered
Quasi-One-Dimensional
Spin
System(CH3)2CHNH3Cu(ClxBr1-x)3 with x=0, 0.025 and 0.3", J.
Phys. Soc. Conf. Proc. 2, 010207-1-5 (2014).
Guo H., Xing H., Tong J., Tao Q., Watanabe I., and Zhu-an
Xu, "Possible Spin Frustration in Nd2Ti2O7 Probed by
Muon Spin Relaxation", Journal of Physics: Condens.
Matter. 26, 436002 (2014).
Hashimoto T. et al. (J-PARC E15 collaboration),- 461 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS"A search for the K-pp bound state in the 3He(K- in-f
light, n) reaction at J-PARC", Proceedings of the 25th
International Nuclear Physics Conference (INPC 2013),
EPJ Web of Conferences 66, 09008 (2014)
Iliescu M., Iwasaki M., Okada S., Tatsuno H. et al.
(SIDDHARTA,SIDDHARTA-2
and
AMADEUSCollaboration), “ Progress and perspectives in the
low-energy kaon-nucleon/nuclei interaction studies atthe DAΦNE collider”, J. Phys. Conf. Ser. 556 (2014)
012004
Ikedo Y., Miyake Y., Shimomura K., Strasser P.,
Kawamura N., Nishiyama K., Makimura S., Fujimori
H., Koda A., Nakamura J., Nagatomo T., Kobayashi Y.,
Adachi T., Pant A.D., Ogitsu T., Nakamoto T,, Sasaki
K., Ohhata H., Okada R., Yamamoto A., Makida Y.,
Yoshida M., Okamura T., Ohkubo R., Higemoto W., Ito
T.U., Nakahara K., Ishida K., "U-Line at MLF/J-PARC
for Ultra Slow Muon Microscopy", JPS Conference
Proceedings 2 (2014) 010103
Ishiwatari T., Iwasaki M., Okada S. et al. (SIDDHARTA
Collaborarion), “ Kaonic Atoms - Results of the
SIDDHARTA Experiment”, Acta Phys. Polon. B45(2014) 787
Ishiwatari T., Iwasaki M., OkadaS. et al. (SIDDHARTA
Collaborarion),“New precision era of experiments onstronginteraction
withstrangenessat
DAFNE/LNF-INFN ”, EPJ Web Conf. 66 (2014) 05016
Itahashi K., "Meson Bound States Spectroscopy in Nuclei:
Pionic Atoms at RIBF and η ’-Mesic Nuclei at
GSI/FAIR", Acta Phys. Polon. B45 (2014) 773*
Kanda S., Fujimori H., Fukao Y., Ikedo Y., Ishida K.,
Iwasaki M., Kawamura N., Kojima K.M., Lee M.,
Makimura S., Mibe T., Miyake Y., Nakamura J.,
Nagashima Y., Nagatomo T., Nagumo K., Nishimura S.,
Okada S., Saito N., Shimomura K., T. Suzuki, Strasser
P., Ueno K., Won E., "Development of High-Rate
Positron Tracker for the Muonium Production
Experiment at J-PARC", JPS Conference Proceedings
2 (2014) 010404
Kawasaki I., Watanabe I., Hillier A.D., and Aoki D.,"Evidence for Time-Reversal Symmetry Breaking in
Both the Hidden Order and Superconducting States of
URu2Si2", J. Phys. Soc. Jpn. 83, 094720-1-5 (2014)*
Kuroe H., Aoki K., Sato T., Kino R., Kuwahara H., Sekine
T., Hase M., Kawasaki I., Kawamata T., Suzuki T.,
Watanabe I., Oka K., Ito T., and Eisaki H.,"Muon spin Spectroscopy in Multiferroic (Cu,Zn)3Mo2O9"
J. Phys. Soc. Conf. Proc. 2, 010206-1-8 (2014).
Månsson M., Umegaki I., Nozaki H., Higuchi, Kawasaki I.,
Watanabe I., Sakurai H., and Sugiyama J.,"Na-Ion Dynamics in Quasi-1D Compound NaV2O4"
J. Phys. Conf. Ser. 551, 012035 (2014).
Månsson M., Nozaki H., Wikberg J.M., Prsa K., Sassa Y.,
Dahbi M., Kamazawa K., Sedlak K., Watanabe I., andSugiyama J., "Lithium Diffusion and Magnetism inBattery Cathode Material LixNi1/3Co1/3Mn1/3O2",
J. Phys. Conf. Ser. 551, 012037 (2014).

Miyazaki K., Saito N., Okamura K., Oishi Y., Louchev
O.A., Iwasaki M. and Wada S., "Tunable 820.65 nm
Light Source by Injection-Seeded Optical Parametric
Oscillator and Amplifier for Muonium Lyman-Alpha
Generation", JPS Conference Proceedings 2 (2014)
010107
Matsuzaki T., Ishida K., Iwasaki M., "High-pressure solidhydrogen target for muon catalyzed fusion", Journal ofRadioanalytical and Nuclear Chemistry,
DOI 10.1007/s10967-015-4080-y
Mohd-Tajudin S.S., Ahmad S.N.A., Hasan-Baseri D.F.,
Suprayoga E., Adam N., Rozlan A.F., Sulaiman S.,
Mohamed-Ibrahim M.I., and Watanabe I., "An
Investigation of Muon Sites in YBa2Cu3O6 by Using
Density Functional Theory", J. Phys. Conf. Ser. 551,
012052 (2014).
Moritsu M., Itahashi K., J-PARC E19 collaboration,"High-resolution search for the Θ+ pentaquark via apion-induced reaction at J-PARC ", Phys.Rev. C90(2014) 035205*
Mukai K., Aoki Y., Andreica D., Amato A., Watanabe I.,
Giblin S.R., and Sugiyama J., "Spin Fluctuation above
100K in Stoichiometric LiCoO2", J. Phys. Conf. Ser. 551,
012008 (2014).
Mukai K., Aoki Y., Andreica D., Amato A., Watanabe I.,
Giblin S.R., and Sugiyama J., "Thermally Activated
Spin Fluctuations in Stoichiometric LiCoO2 Clarified byElectron Paramagnetic Resonance and Muon-Spin
Rotation and Relaxation Measurements", Phys. Rev. B
89, 094406-1-11 (2014)*
Nakamura J., Nagatomo T., Oishi Y., Ikedo Y., Strasser P.,
Saito N., Miyazaki K., Yokoyama K., Okamura K.,
Miyake Y., Makimura S., Nishiyama K., Shimomura K.,
Kawamura N., Koda A., Higemoto W., Wada S., IwasakiM., Torikai E., "Ultra Slow Muon Microscope at MUSE /J-PARC",J.Phys.Conf.Ser. 502 (2014) 012042*
Nakamura J., Oishi Y., Saito N., Miyazaki K., YokoyamaK., Okamura K,, Makimura S., Miyake Y., Nagatomo T.,
Strasser P., Ikedo Y., Tomono D., Shimomura K., WadaS., Kawamura N., Koda A. and Nishiyama K., ,"Transportof Coherent VUV Radiation to Muon U-Line for Ultra
Slow Muon Microscope", JPS Conference Proceedings 2(2014) 010108
Nishi T., Berg G.P.A., Dozono M., Fujioka H., Fukuda M.,
Furuno T., Geissel H., Hayano R.S., Inabe N., ItahashiK., Itoh S., Kameda D., Kubo T., Matsubara H.,
Michimasa
S., Miki K., Miya H., Murakami Y.,
Nakamura M., Nakatsuka M., Noji S., Okochi K., Ota S.,
Suzuki H., Suzuki K., Takaki M., Takeda H., Tanaka
Y.K., Todoroki K.,Tsukada K., Uesaka T., Watanabe Y.N.,
Weick H., Yamada H., Yoshida K., "The first precision
measurement of deeply bound pionic states in 121Sn",
EPJ Web Conf. 66 (2014) 09014
Nishimura K., Matsuda K., Komaki Y., Nunomura N.,
Wenner S., Holmestad R., Matsuzaki T., Watanabe I.,
Pratt F.L., and Marioara C.D., "μSR Study of Al-0.67%- 462 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Mg-0.77%Si Alloy", J. Phys. Conf. Ser. 551, 012031(2014).
Nozaki H., Harada M., Ohta S., Asaoka T., Watanabe I.,
Pomjakshin V., kedo Y., Miyake Y., Jaralvo N.H.,
Mamontov E., and Sugiyama J., “Diffusive Behavior of
Li Ions in Garnet Li5+xLa3ZrxNb2-xO12 Studied with both
QENS and μ SR”, Solid State Ionics 262, 585-588(2014).
Ohnishi H., Iwasaki M., Sakuma F., Yokkaichi S., Bühler
P., Hartmann O., Ishiwatari T., Marton J., Suzuki K.,
Widmann E., Zmeskal J. Curceanu C., Guaraldo C.,
Okada S., Vidal A.R., Sirghi D., Sirghi F., Vazquez DoceO., Hicks K., Muto R., Naruki M., Sawada S., Niiyama
M., Noumi H., Sakaguchi A., Tsukada K., "A Search for
φ Meson Nucleus Bound State Using Antiproton
Annihilation on Nucleus", Acta Phys.Polon. B45 (2014)
819-826*
Oishi Y., Okamura K., Miyazaki K., Saito N., Iwasaki M.,
Wada S., ”All-solid-state laser amplifiers for intense
Lyman-α generation” Proceedings of the International
Symposium on Science Explored by Ultra Slow Muon.
Vol.2, 010105-1～5 (2014)
Okada Y., Yagi E., Matsuba H., Sugi C., Koike S.,
Nakamura S., Sugawara T., Shishido T. and Ogiwara K.,“Site occupancy of hydrogen in Ta-rich Ta-Nb alloys as
observed by the channelling method”, J. Phys. Soc. Jpn.
83 (2014) 064602-1–9.
Okamura K., Saito N., Miyazaki K., Oishi Y., Louchev O,,
Iwasaki M. and Wada S., "Temporally Resolved
Spectral Structure of 821 nm Broad-Area Laser Diode
Seeder for Muonium Lyman-Alpha Generation", JPS
Conference Proceedings 2 (2014) 010106
Pant A.D., Nagamine K., Shiraki I., Torikai E.,
Shimomura K., Pratt F.L., Ariga H., Ishida K., andSchultz J.S., “Muonium Responses to Oxygen Content
in Biological Aqueous Solutions for Cancer Research”,
J. Phys. Conf. Ser. 551, 012043 (2014)
Risdiana, Safriani L., Somantri W.A., Saragi T., Adachi T.,
Kawasaki I., Watanabe I., and Koike Y.,"Impurity-Induced
Magnetic Order in Electron-Doped Superconducting Cuprates
Eu1.85Ce0.15Cu1-yNiyO4+α-δ Studied by Muon-Spin-Relaxation",
Advanced Materials Research 896, 354-357 (2014)*
Sada Y., Hashimoto T., Itahashi K., Ma Y., Iwasaki M.,
Ohnishi H., Okada S., Outa H., Sakuma F., Sato M.,
Tokuda M., Tomono D., Yamazaki T., Zhang Q. et al.
(J-PARC E15 Collaboration),“A Search for Deeply-boundKaonic Nuclear States by In-flight 3He(K−,n) Reaction
at J-PARC”, EPJ Web Conf. 81 (2014) 02016
Safriani L., Risdiana, Bahtiar A., Aprilia A., Siregar R.E.,
Hidayat R., Saragi T.P.I, Kawasaki I., and Watanabe I.,"Charge Carrier Dynamics of Active Material Solar Cell
P3HT: ZnO Nanoparticles Studied by Muon Spin
Relaxation (μSR)", Advanced Materials Research 896,
477-480 (2014)*
Sakuma F., Hashimoto T., Itahashi K., Iwasaki M., Ma. Y.,
Okada S., Ohnishi H., Outa H., Sato M., Tokuda M.,
Yamazaki T. (J-PARC E15 collaboration), "A Search

for Deeply-bound Kaonic Nuclear States by In-flight
3He(K-,n) Reaction at J-PARC", Proceedings of theSecond International Symposium on Mesic Nuclei,
Acta Phys. Pol. B45, 767 (2014)*
Shi H., Iwasaki M., Okada S. et al. (SIDDHARTA
Collaborarion), “The yield of kaonic hydrogen X-rays in
the SIDDHARTA experiment”, EPJ Web Conf. 66(2014) 09016
Sierawski B.D., Bhuva B., Reed R., Ishida K., Tam N.,
Hillier A., Narasimham B., Trinczek M., Blackmore E.,
Wen Shi-Jie, and Wong R., "Bias Dependence ofMuon-Induced Single Event Upsets in 28 nm Static
Random Access Memories", Reliability Physics Symposium,
2014 IEEE International , vol., no., pp.2B.2.1,2B.2.5, 1-5
June 2014, doi: 10.1109/IRPS.2014.6860585
Suprayoga E., Nugroho A.A., Polyakov A,O., Palstra
T.T.M. , and Watanabe I.,"Search for Potential
Minimum Positions in Metal-Organic Hybrids,(C2H5NH3)2CuCl4 and (C6H5CH2CH2NH3)2CuCl4, byUsing Density Functional Theory", J. Phys. Conf. Ser.
551, 012054 (2014).
Suzuki T., Watanabe I., Yamada F., Ishii Y., Ohishi K.,
Goto T., and Tanaka H.,"Gradual Evolution in Spin
Dynamics of TlCu1-xMgxCl3 Probed by Mon-Spin-Relaxation(μSR) Technique", Journal of Physics: Conference Series
502, 012041-1-14 (2014).
Tanabe Y., Adachi T., Suzuki K. , Akoshima M.,
Kawamata T., Ishii Y., Suzuki T., Watanabe I., andKoike Y., “Development of Spatial Inhomogeneity ofInternal Magnetic Field above TC inBi2Sr2Ca1-xYxCu2O8
Observed by Longitudinal-Field Muon-Spin-Relaxation”
J. Phys. Soc. Jpn. 83, 074707-1-5 (2014)*
Tanaka K.S., Aoki M., Iinuma H., Ikedo Y., Ishida K.,
Iwasaki M., Ueno Y., Ohkubo R., Ogitsu T., Kadono R.,
Kamigaito O., Kawamura N., Kawall D., Kanda S.,
Kubo K., Kume T., Koda A., Kojima K., Saito N.,
Sakamoto N., Sasaki K., Shimomura K., Sugano M.,
Tomono D., Toyoda A., Torii H.A., Torikai E., Nagamine
K., Nishiyama K., Strasser P., Fukao Y., Fujiwara Y.,
Matsuda Y., Mibe T., Miyake Y., Yoshida M.,"Measurement of Muonium Hyperfine Splitting at
J-PARC", JPS Conference Proceedings 2 (2014) 010405
Tanaka Y.K., Brinkmann K.T., Friedrich S., Fujioka H.,
Geissel H.,Hayano R.S., Hirenzaki S., Itahashi K., ItohS., Jido D., Metag V., Nagahiro H., Nanova M., Nishi T.,
Okochi K., Outa H., Suzuki K., Suzuki T., Watanabe
Y.N., Weick H., "Missing Mass Spectroscopy of η′
Mesic Nuclei with the (p,d) Reaction at GSI",
EPJ Web Conf. 66 (2014) 09019
Tomida N., Niiyama M., Ohnishi H., Tran M., Hsieh C.-Y.,
Chu M.-L., Chang W.-C., Chen J.-Y., "Large strip
RPCs for the LEPS2 TOF system", Nucl. Instrum. Meth.
A766 (2014) 283-287*
Watanabe Y.N., Berg G.P.A, Dozono M., Fujioka H.,
Fukuda N., Furuno T., Geissel H., Hayano R.S., InabeN., Itahashi K., Itoh S., Kameda D., Kubo T.,
Matsubara H., Michimasa S., Miki K., Miya H.,- 463 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Murakami Y., Nakamura M., Nakatsuka N., Nishi T.,
Noji S., Okochi K., Ota S., Suzuki H., Suzuki K., TakakiM., Takeda H., Tanaka Y.K., Todoroki K., Tsukada K.,
Uesaka T., Weick H., Yamada H., Yamakami H.,
Yoshida K., "Status and future plan of the spectroscopyof pionic atoms",
J.Phys.Conf.Ser. 503 (2014) 012037

Oral Presentations(International Conference etc.)
Hashimoto T., Itahashi K., Iwasaki M., Ma. Y., Okada S.,
Ohnishi H., Outa H., Sakuma. F., Sato M., Yamazaki T.
(J-PARC E15 collaboration), "Search for the K-pp boundstate via the 3He(K-,n) reaction at 1 GeV/c", 3rdInternational Workshop on "State of the Art in Nuclear
Cluster Physics" (SOTANCP3), KGU Kannai Media
Center, Kanto Gakuin University, Yokohama, Japan.,May(2014)
Hashimoto T., Itahashi K., Iwasaki M., Ma. Y., Okada S.,
Ohnishi H., Outa H., Sakuma. F., Sato M., Yamazaki T.
(J-PARC E15 collaboration), "Search for the K-pp boundstate via the infight-kaon reaction on helium-3", 20th
Particles and Nuclei International Conference 2014
(PANIC2014), Hamburg, Germany, Aug.(2014)
Itahashi K., "Experimental spectroscopy of pionic atoms
and eta'-mesic nuclei”, HHIQCD14, Kyoto, Mar. (2015)
Itahashi K., "Precision measurement of deeply boundpionic Sn atoms in RIBF”, EXA14, Vienna, Sep. (2014)
Itahashi K., "High precision systematic measurement of
deeply bound pionic atoms”, 4th Joint Meeting of the
APS Division of Nuclear Physics and the PhysicalSociety of Japan, Hawaii, Oct. (2014)
K., Hashimoto T., Itahashi K., Iwasaki M., Ma. Y., Okada
S., Ohnishi H., Outa H., Sakuma. F., Sato M., Yamazaki
T.,(J-PARC
E15
collaboration),"A
SearchforDeeply-bound Kaonic nuclear states", The 3rd
Korea-Japan Workshop on Nuclear and Hadron Physics
at J-PARC, Inha University, Korea, Mar.(2014)
Kawasaki S.,Hashimoto T., Itahashi K., Iwasaki M., Ma.
Y., Okada S., Ohnishi H., Outa H., Sakuma. F., Sato M.,
Yamazaki T. (J-PARC E15 collaboration), "Experimental
search for K-pp deeply bound statevia in-flight
3He(K-,n) reaction at J-PARC K1.8BR", The 2nd
International Symposium on Science at J-PARC 2014,
Tsukuba, Japan, Jul.(2014)
Okada S., Bennett D. A., Doriese. W. B., Fowler. J. W.,
Irwin. K. D., Ishimoto S., Sato M., Schmidt. D. R.,
Swetz. D. S., Tatsuno H., Ullom. J. N., Yamada S.,“Study of strong interaction between anti-kaon andnucleus via high-resolution kaonic-atom x-ray
spectroscopy with superconducting transition-edge-sensor
microcalorimeters”, Suzaku-MAXI 2014 (Expanding the
Frontiers of the X-ray Universe), Matsuyama, Feb.
(2014).
Sada Y., Hashimoto T., Itahashi K., Iwasaki M., Ma. Y.,
Okada S., Ohnishi H., Outa H., Sakuma. F., Sato M.,

Yamazaki T. (J-PARC E15 collaboration), "Search for
the K-pp bound state via the in-flight 3He(K-,n)reaction", 13th International Workshop on Meson
Production, Properties and Interaction (MESON2014),
Krakow, Poland, Jun.(2014)
Sakuma F., Hashimoto T., Itahashi K., Iwasaki M., Ma. Y.,
Okada S., Ohnishi H., Outa H., Sato M., Yamazaki T.
(J-PARC E15 collaboration), "Recent results and future
prospects of the KbarNN search via the (K-,N) reaction
at J-PARC", Achievements and Perspectives in
Low-Energy QCD with Strangeness, ECT*, Italy,Oct.(2014)
Tanaka Y.K.,"Search for η' mesic nuclei with (p,d) reaction at GSI”,
4th Joint Meeting of the APS Division of Nuclear
Physics and the Physical Society of Japan, Hawaii, Oct.
(2014)
Tanaka Y.K.,"Eta' mesic nucleus spectroscopy with (p,d) reaction at
GSI" , 20th Particles and Nuclei International
Conference (PANIC2014), 25-29, August, 2014, Hamburg,
Germany
足立匡, 高橋晶, 鈴木謙介, Baqiya M.A. ,今野巧也,高松智寿,加藤雅恒, 渡邊功雄, 幸田章宏, 宮崎正範, 門野良典,
小池洋二, “Novel Coexistence of Superconductivity with
Short-Range Magnetic Order in Electron-Doped High-TC
T'-Cuprates”,The 2nd International Symposium on
Science at J-APRC, J-PARC, 東海村. 茨城県, 2014 年 7月
足立匡, 高橋晶, 鈴木謙介, Baqiya M.A.,今野巧也,高松智寿,加藤雅恒, 渡邊功雄, 幸田章宏,宮崎正範, 門野良典,
小池洋二,“Novel Coexistence of Superconductivity with
Short-Range Magnetic Order in High-TC T'-Cuprates
Observed by Muon Spin Relaxation”, Superstripes 2014,
Erice, Sicily, イタリア, 2014 年 7 月
渡邊功雄,松平和之,川崎郁斗,分島亮,日夏幸雄,Zhu-an Xu“μSR Sudies of Spin Ground States in the Pyrochlore
Iridate Nd2Ir2O7”, 2014 Collaborative Conference 3D
and Materials Researchs (CC3DMR2014) 韓国仁川, 2014年6月
渡邊功雄
“Muon Site Estimation in La2CuO4 by the Density
Functional Theory”, 2nd International Conference on
Functional Material Science 2014, Lombok, インドネシ
ア, 2014 年 11 月
Abdel-Jawad M.M., 渡邊功雄,石井康之,田嶋尚也,加藤礼
三 , “Universality Class Of The Mott Transition In
EtMe3P[Pd(dmit)2]2”,Internaional
Conferenceon
Synthetic Metals ICSM2014, Turku, フィンランド、2014
年 6月
Lees M.R., Chang L.-J.,渡邊功雄, Hillier A.D.,安井幸夫,小野田茂樹,Balakrishnan G., Lhotel E., Giblin S.R.,“Studies of Magnetic Order in Yb2Ti2O7”
International Conference on Highly Frustrated
Magnetism 2014 (HFM2014), Cambridge, 英国, 2014年7月
小池洋二, 鈴木謙介, 足立匡, 佐藤輔, 渡邊功雄

- 464 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)“Novel Fe-Induced Magnetism in the Overdoped
Regime of the La-214 High-TC Curate: Implication for
Dtripe Fluctuation”, 27th International Conference on
Low Temperature Physics(LT27), Buenos Aires, 2014
年 8 月
(Domestic Conference)
足立匡, 高橋晶, 鈴木謙介, M.A. Baqiya, 渡邊功雄, 幸田
章宏, 宮崎正範, 門野良典, 小池洋二: “μSR からみ
た電子型 T'-214 高温超伝導体における Cu スピン相関とノンドープ超伝導”, 第 2 回物構研サイエンスフェスタ,
KEK, 茨城県つくば市, 1 月(2014)
足立匡, 高橋晶, 鈴木謙介, Baqiya M.A., 今野巧也, 高松
智寿、加藤雅恒, 渡邊功雄, 幸田章宏, 宮崎正範, 門野良典小池洋二, “電子型 T'-214 高温超伝導体における超伝導と短距離磁気秩序の新奇な共存”, 日本物理学会秋の大会,中部大学,名古屋, 2014 年 9 月
足立匡, 高橋晶, 鈴木謙介, Baqiya M.A.,今野巧也,高松智寿,加藤雅恒, 渡邊功雄, 幸田章宏, 宮崎正範, 門野良典,
小池洋二, “電子型 T'高温超伝導体における超伝導と短距離磁気秩序の新奇な共存”, 新学術領域「超低速ミュオン顕微鏡」第 3 回領域会議, 東北大学、仙台市、2014 年
9月
上原友敬, 伊藤美穂, 谷口浩三, 佐藤和彦, 石井康之, 渡邊功雄, “μSR Study of κ-(h8-BEDT-TTF)2Cu[N(CN)2]Cland Discussion of Muon Site Using Relaxation Signal
from Deuterated κ-(d8-BEDT-TTF)2Cu[N(CN)2]Br”
1st RIKEN-Sophia Joint Syposium Recent Progresseson the Muon-Site Estimation, 上智大学, 四谷, 東京,
2014 年 12 月
板橋健太,
"η中間子原子核分光実験の検討”, ELPH 研究会 C009
「光生成反応によるハドロン間相互作用の研究の進展」,
仙台, 11 月 (2014)
應田治彦, 板橋健太, 岩崎雅彦, Ma Y, 岡田信二,大西宏明,
佐 久 間 史 典, 佐 藤 将 春, 山崎 敏 光 , E15 collaborator :“E15 experiment on K-pp”, KEK theory center
workshop on J-PARC hadron physics in 2014, つくば市,
2 月(2014).
應田治彦（for J-PARC E15 Collaboration）“Status of kaonic nucleus search experiment (E15) at
J-PARC”,新学術研究領域「実験と観測で解き明かす中性子星の核物質」 研究会,熱川ハイツ, 2014 年 9 月
岡田信二, 石田勝彦，岩崎雅彦，上野一樹，Eunil Won，
大石裕，Art Olin，河合秀幸，河村成肇，神田聡太郎,
北村遼，齊藤直人，下村浩一郎，Patrick Strasser，
田端誠，友野大，西村昇一郎，Pavel Bakule, George Beer，
藤原裕也，Glen Marshall，松田恭幸，三部勉，三宅康博，
横山幸司，Woodo Lee: “超低速ミュオン生成のための室温ミュオニウム真空放出源の開発” 日本物理学会第 69 回
年次大会, 平塚市, 3 月(2014).
川崎郁斗, 横山淳, 藤村健司, 渡邊功雄, 天谷健一
“ミュオンスピン緩和法からみた Sr1-xLaxRuO3 における不均一強磁性クラスターの形成”,日本物理学会秋の大会,
中部大学, 名古屋, 2014 年 9 月
北村遼，深尾祥紀，石田勝彦，河村成肇，近藤恭弘，三部勉，
三宅康博，大谷将士，Patrick Strasser，齊藤直人，下村浩一郎 他 J-PARC muon g-2/EDM コラボレーション,"J-PARC ミューオン g-2/EDM 精密測定実験のためのミューオン再加速試験に向けた低速ミューオン源開発の準備
状況", 日本物理学会第 70 回年次大会,
早稲田大学,東京, 3 月(2015)
後藤貴行, 松井一樹, 足立匡, 大槻東巳, 田邉洋一, 渡邊功雄, “トポロジカル絶縁体におけるスピンロック現象μ
SR 検出“, 新学術領域「超低速ミュオン顕微鏡」第 3 回領域会議, 東北大学、仙台市、2014 年 9 月
小林弘明, 岡澤厚, 小島憲道, 川崎郁斗, 渡邊功雄: “スピン平衡を示すスピンクロスオーバー鉄 (II) 錯体におけるメ
スバウアー分光とミュオン分光からみた動的挙動”, メス
バウアー分光研究会, 東大本郷キャンパス, 3 月(2014)
今野巧也, 足立匡, 扇太郎, 高橋晶, 加藤雅恒, 渡邊功雄, 小黒英俊, 淡路智, 小池洋二, “電子ドープ型超伝導体
Pr1.3-xLa0.7CexCuO4+ δ } (x≦0.1)単結晶における還元アニ
ール効果と電子状態”, 日本物理学会春の大会, 早稲田大学, 東京, 2015 年 3 月
佐久間史典 (for J-PARC E15 collaboration), “J-PARC E15
実験における K 中間子原子核探索の最近の進展”,新学術
研究領域「実験と観測で解き明かす中性子星の核物質」 研究会,熱川ハイツ, 2014 年 9 月
佐 久 間 史 典 (for J-PARC E15 collaboration), “Recent
results and future prospects of the KbarNN search @J-PARC E15”, 原子核媒質中のハドロン研究 II, J-PARC,
2014 年 10 月
佐田優太, 板橋健太, 岩崎雅彦, 應田治彦, 岡田信二, 大西
宏明, 佐藤将春, 佐久間史典, 徳田真, 橋本直, 山崎敏光,
Ma Yue (J-PARC E15 実験): "J-PARC K1.8BR における3He(K-,Λpn)反応を用いての K-多核子吸収の研究",日本物理学会第 69 回年次大会, 東海大学, 神奈川, 3 月(2014)
鈴木謙介, 足立匡, Hanjie Guo, 川崎郁斗, 渡邊功雄, 小池
洋二：“La2-xSrxCu1-yAlyO4 のオーバードープ領域における Al 誘起磁気秩序”,日本物理学会大 69 回年次大会, 東海大学湘南キャンパス, 神奈川県, 3 月(2014)
鈴木謙介, 足立匡, Baqiya M.A.,Guo H., 川崎郁斗、今野巧也、Jawad M.A., Yoon S., 渡邊功雄, 小池洋二, “Impurity
substitution effects on magnetic correlation in
La2-xSrxCu1-yMyO4 (M = Fe, Al)”, Research Frontier ofTransition-metal Compounds Opened by Advanced
Spectroscopies, 東北大, 仙台, 2014 年 9 月
鈴木栄男, Hanjie Guo, 川崎郁斗, 渡邊功雄, 片山和哉, 後藤貴行, 田中秀数: “ミュオンスピン緩和でみたボースグラ
ス相 Tl$_{1-x}$K$_x$CuCl$_3$ のゼロ磁場極限における磁気的基底状態”, 日本物理学会大 69 回年次大会, 東海大学湘南キャンパス, 神奈川県, 3 月(2014)
高尾健太, 劉鐘昇, 宇治克俊, 太田寛人, 和氣剛、田畑吉計,
渡邊功雄, 中村裕之, “Cr 系逆ペロフスカイト型窒化物の磁性”, 日本物理学会春の大会, 早稲田大学, 東京, 2015年3月
田中良樹, "(p,d)反応の分光によるη′中間子原子核の探索”, 日本物理学会第７０回年会、早稲田、３月(2015)
渡辺珠以, "逆運動学によるパイ中間子原子分光のための重水素ガスドリフトチェンバーの開発”, 日本物理学会第７０回年会、早稲田、３月(2015)
中野岳仁, Gayan Prasad Hettiarachchi, 石井康之, 渡邊功雄, 野末泰夫: “ゼオライト LSX 中の Na-K 合金クラス
ターが示すフェリ磁性の He による圧力効果” , 日本物理- 465 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

学会大 69 回年次大会, 東海大学湘南キャンパス, 神奈川県, 3 月(2014)
中野岳仁, Hettiarachchi G.P., 岸本亮三, 石井康之,
渡邊功雄, 野末泰夫, “ゼオライト LSX 中の Na-K 合金クラスターが示すフェリ磁性の He による圧力効果 II”,
日本物理学会秋の大会, 中部大学, 名古屋, 2014 年 9 月
中 野 岳 仁 , 谷 辺 健 志 , Kien L.M., Yoon S., Majed
Abdel-Jawad, Pratt F.L., 渡邊功雄, 野末泰夫, “ソーダライト中の K-Rb 合金および Rb クラスターの μSR“,日本物理学会春の大会, 早稲田大学, 東京, 2015 年 3 月
劉鐘昇、宇治克俊、和氣剛、田畑吉計、中村裕之、渡邊功雄“Cr3GeN の構造と磁性“, 粉体粉末冶金協会春季大会、早稲田大学、東京都、2014 年 6 月
渡邊功雄, “Applications of a DC Muon Source to the
Muon to Material Science”, RISP scientific Seminar,
RISP, 太田市, 韓国 1 月(2014)
渡邊功雄: “Applications of Pulsed Muon Beam to Material
Science at the RIKEN-RAL
Muon Facility”,
NTNU Science Seminar, NTNU, Trondheim, ノルウェー, 1 月(2014)
渡邊功雄: “μSR から見たパイロクロア酸化物 Yb2Ti2O7 のスピンダイナミクス”, 三機関連携による量子複雑現象研
究会, 理研、埼玉県和光市, 1 月(2014)
渡邉功雄, ”Applications of the Pulsed Muon Beam at the
RIKEN-RAL Muon Facility”, 3rd Workshop forLight/Quantum Beam Science Promotion, Tohoku
University New insight into materials and life sciencesusing light/quantum beams (III) ---Introduction ofoverseas facilities and cooperation with Tohoku
University---, 宮城県仙台市, 東北大学金研, 3 月(2014)
渡 邊 功 雄 , “Muon Site Estimation in La2CuO4 by theDensity Functional Theory”, RIKEN Symposium: 1st
RIKEN-Sophia Joint Syposium “Recent Progresses on
the Muon-Site Estimation”,上智大学, 四谷, 東京, 2014年 12 月
渡邊功雄, “ミュオン位置計算法の最近の進展”, 第 8 回 三機関連携「量子複雑現象」研究会, SPring-8, 西播磨, 兵庫県,
2015 年 1 月
渡辺珠以, "逆運動学によるパイ中間子原子分光のための重水素ガスドリフトチェンバーの開発”, 日本物理学会第７０回年会、早稲田、３月(2015)
Adam M., Suprayoga E., Mohd Tajudin S.S., 谷田博司,世良正文, Sulaiman S., Mohamed Ismail M.I., 渡邊功雄
“The Electronic Structures of CeRu2Al10 and Muon Sites
Studied by DFT”
日本物理学会春の大会, 早稲田大学, 東京、2015 年 3 月
Adam A., Adiperdana B., Suprayoga E., Sakinah
Mohd-Tajudin S., A. Fauzeeha Rozlan, Slaiman S.,
Mohamed-Ibraham M.I., Guo H., 谷田博司, 世良正文,
西岡孝, 松村政博, 渡邊功雄,“Ce(Ru,Rh)2Al10 におけるミュオン位置計算と磁気モーメント構造および超微細場に関する考察”, 日本物理学会大 69 回年次大会, 東海大学
湘南キャンパス, 神奈川県, 3 月(2014)
Budi Adiperdana, Edi Suprayoga, Aina Adam, Irwan A.
Dharmawan, Rustam
Siregr, Saidah Sakinah
Mohd-Tajudin, Ainul Fauzeeha Rozlan, Shukri Slaiman,
Mohamad Ismail Mohamed-Ibraham, 川股隆行, 足立匡,小 池 洋 二 , Pabitra Kumar, Alex Amato, 渡 邊 功 雄 ,“La2CuO4 におけるミュオン位置計算およびミュオンから見た Cu モーメントの状態”, 日本物理学会大 69 回年次大会, 東海大学湘南キャンパス, 神奈川県, 3 月(2014)
Rozlan A.F., Sulaiman S., Mohamed-Ibrahim M.I.,渡邊功雄, “Electronic Structure and Hyperfine Interaction of
Muonated La2CuO4”,1st RIKEN-Sophia Joint Syposium
Recent Progresses on the Muon-Site Estimation,
上智大学, 四谷, 東京, 2014 年 12 月
Mohd-Tajudin S.S., Adam M., Suprayoga E., Sulaiman S.,
Mohamed-Ibrahim M.I., 渡 邊 功 雄 ,“First-Principles
Calculation of Electronic Structure and Muon Sites in
YBa2Cu3O6”,日本物理学会春の大会, 早稲田大学, 東京,
2015 年 3 月
Suprayoga E., Adiperdana B., Adam A., Mohd-Tajudin
S.S., Rozlan A.F., Slaiman S., Mohamed-Ibraham M.I.,
Guo H., 谷 田 博 司 , 世 良 正 文 , 西 岡 孝 , 松 村 政 博 ,Nugroho A.A., 渡邊功雄, “Study on the Hyperfine Fields
and
Muon
Site
Calculationin
CeRu2Al10
Kondo-Semiconductor”, 日本物理学会大 69 回年次大会,
東海大学湘南キャンパス, 神奈川県, 3 月(2014)
Suprayoga E., Nugroho A.A., Polyakov A.O. Palstra T.T,M.,
渡邊功雄,“Electronic
Structureof(C6H5CH2CH2NH3)2CuCl4
and(C2H5NH3)2CuCl4
Organic-Inorganic Hybrid Materials”, 日本物理学会春の大会, 早稲田大学, 東京, 2015 年 3 月
Zhang Q.,
“Kalman Filter for E15 Experiment at
J-PARC”,日本物理学会春の大会, 早稲田大学, 東京, 2014年3月

- 466 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

RBRC Theory Group
Publications[Journal](Original Papers) *Subject to Peer Review
Bezrukov F, Gorbunov D, : ”Relic Gravity Waves and 7
keV Dark Matter from a GeV scale inﬂaton”, Phys.Lett.
B Volume 736 Page 494-498, 2014/09/07 *Bezrukov F, Shaposhnikov M, : ” Higgs inﬂation at thecritical point ”, Phys.Lett. B Volume 734 Page 249-254,
2014/06/27 *Cho S., Hattori K., Lee S. H., Morita K., and Ozaki S.:“Charmonium Spectroscopy in Strong Magnetic Fields
by QCD Sum Rules: S-Wave Ground States”, Phys.Rev.
D 91, 045025 (2015)*
Cho S., Hattori K., Lee S. H., Morita K., and Ozaki
S.: “QCD Sum Rules for Magnetically Induced Mixing between ηc and J/ψ”, Phys.Rev. Lett. 113, 172301(2014)*
Xu J, Liao J, Gyulassy M, : Consistency of perfect ﬂuidity and jet quenching in semi-quark-gluon monopole
plasmas”, arXiv:1411.3673[hep-ph]
Jiang Y, Huang X-G, Liao J, : ”Chiral electric separationeﬀect in the quark-gluon plasma”, Physical Review D
Volume 91 Issue 4 Article 045001, 2015 *Shi S, Liao J, Zhuang P, : Ripples on a relativistically
expanding ﬂuid”, Physical Review C Volume 90 Issue 6
Article 064912, 2014 *Huang X-G, Liao J, : Kinetic evolution of the glasma
and thermalization in heavy ion collisions”, International Journal of Modern Physics E Volume 23 Article
1430003, 2014 *Liao J, : Anomalous transport eﬀects and possible environmental symmetry violation in heavy-ion collisions”,
Pramana Volume 84 Issue 5 Article 901, 2015 *Li D, Liao J, Huang M, : Enhancement of jet quenching around phase transition: result from the dynamical
holographic model”, Physical Review D Volume 89 Issue
12 Article 126006, 2014 *Bloczynski, Huang X-G, Zhuang X, Liao J, : Chargedependent azimuthal correlations from AuAu to UU collisions”, Nuclear Physics A Volume 939 Article 85, 2015*
Lin, S, Robert D. Pisarski, Vladimir V. Skokov: ”Collisional energy loss above the critical temperature in
QCD”, Physics Letter B Volume 730, Pages 236242,
2014/03/07 *K. Kashiwa, A. Monnai: ”Quark contribution for center domain in heavy ion collisions”, Physical Review
D Rapid Communications Volume 89 Issue 1 Article
011501 Page 1-5, 2014/01/07 *A. Monnai : ”Thermal photon v2 with slow quark chemical equilibration”, Physical Review C Rapid Communications Volume 90 Issue 2 Article 021901 Page 1-5,
2014/08/11 *Gamberg L, Kang Z-B, Metz A, Pitonyak D, Prokudin A,: Left-right spin asymmetry in ℓN ↑ → hX, PhysicalReview D Volume 90 Issue 7 Article 074012 Page 1-12,
2014/10/01 *Kanazawa K, Koike Y, Metz A, Pitonyak D, : Towards
an explanation of transverse single-spin asymmetries inproton-proton collisions: the role of fragmentation incollinear factorization, Physical Review D Volume 89
Issue 11 Article 111501(R) Page 1-5, 2014/06/01 *Pitonyak D, Schlegel M, Metz A, : Polarized hadron pair
production from electron-positron annihilation, PhysicalReview D Volume 89 Issue 5 Article 054032 Page 1-20,
2014/03/01 *Yee H.-U, Yin Y, : ”Realistic Implementation of Chiral
Magnetic Wave in Heavy Ion Collisions”, Physical Review C Volume 89 Issue 4 Article 044909 Page 1-11,
2014/04/28 *Chen J, Son D, Stephanov M, Yee H.-U, Yin Y, : ”Lorentz
Invariance in Chiral Kinetic Theory”, Physical Review
Letters Volume 113 Issue 18 Article 182302 Page 1-5,
2014/10/30 *Satow D, Yee H.-U, :”Chiral Magnetic Eﬀect at
Weak Coupling with Relaxation Dynamics”, PhysicalReview D Volume 90 Issue 1 Article 014027 Page 1-12,
2014/07/17 *Yee H.-U, :”Chiral Magnetic and Vortical Eﬀects in
Higher Dimensions at Weak Coupling”, Physical Review D Volume 90 Issue 6 Article 065021 Page 1-24,
2014/09/16 *[Book, Proceedings](Books)A. Monnai : ”Relativistic Dissipative Hydrodynamic Description of the Quark-Gluon Plasma”, Springer Theses
ISBN 978-4-431-54797-6 Page 1-127, 2014/01/30 *(Original Papers)
Fedor Bezrukov: ”The Planck and LHC results and particle physics”, PoS EPS-HEP2013 (2013) 476 .
Jean-Paul Blaizot, Jinfeng Liao, Larry McLerran: Gluon
transport equation in the small angle approximationand the onset of Bose-Einstein condensation”, Nuclear
Physics A 931(2014)359 .
Jinfeng Liao: The extraordinary glow”, Nuclear Physics
A 928(2014)247 .
Lin, S, Yoshimasa Hidaka, Robert D. Pisarski, Daisuke
Satow, Vladimir D. Skokov: ”Production of dilepton/photon in semi-quark gluon plasma”, Nucl.Phys.
A931 (2014) 681-685 .
A. Monnai :”Eﬀects of quark chemical equilibrationon thermal photon elliptic ﬂow”, Journal of Physics:
Conference Series Volume 612 Article 012026 Pages 1-4
2015/05/19 *Oral Presentations(International Conference etc.)
Bezrukov F: ”Higgs Inﬂation – relating particle physics- 467 -

1

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

and cosmology”, The 4th KIAS Workshop on Particle Physics and Cosmology Seoul, South Korea,
2014/11/30.
Bezrukov F: ”Vacuum stability and the Higgs boson”,
SUSY-2014 Manchester, England, 2014/07/24.
Bezrukov F: ”Models of keV scale sterile neutrino
Dark Matter”, MIAPP workshop Munich, Germany,
2014/07/10.
Bezrukov F: ”Higgs inﬂation and large gravity waves –status and predictivity”, QUARKS-2014 Suzdal, Russia,
2014/06/05.
Hattori K.: “Charmonium spectroscopy in strong magnetic ﬁelds by QCD sum rules”, Hadrons and HadronInteractions in QCD – Eﬀective theories and Lattice– (HHIQCD2015), YITP, Kyoto Univ., Japan, Mar.
(2015).
Hattori K.: “Photon propagation in strong magnetic
ﬁelds”, QCD Chirality Workshop 2015, UCLA, USA,
Jan. (2015).
Cho S., Hattori K., Lee S. H., Morita K., and Ozaki
S., “Charmonium spectroscopy in strong magnetic ﬁelds
by QCD sum rules”, Fourth Joint Meeting of the Nuclear Physics Divisions of the American Physical Society
and The Physical Society of Japan, Hawaii, USA, Oct.
(2014).
Liao, J: Condensed Matter Physics of Strong Interaction”, Six Lectures for Advanced Summer Course
Physics Department, Fudan University, Shanghai,
China, 2014/07/28.
Liao, J: Pre-Equilibrium Physics in Heavy Ion Collisions”,
Lecture at “2014 Berkeley Summer School on Collective
Dynamics” Berkeley, California, USA, 2014/06/09.
Liao, J: Geometry & Physics of Jet Quenching, and What
We Can Learn from Heavy Flavor”, The 1st HFT+
Meeting of STAR Collaboration UIC, Chicago, Illinois,
USA, 2014/12/01.
Liao, J: Chiral Eﬀects and Anomalous Transport in the
Extreme Matter”, The 2nd Workshop on “QCD Vacuum and Matter under Strong Magnetic Field” IHEP,
Beijing, China, 2014/10/17.
Liao, J: Theoretical Summary on QGP at RHIC and LHC
and Future”, Joint JPA/APS DNP Annual Fall Meeting2014 Big Island, Hawaii, USA, 2014/10/07.
Liao, J: Chiral Eﬀects under Extreme Conditions”, BES II
Workshop 2014 Berkeley, California, USA, 2014/09/28.
Liao, J: Ripples on Relativistically Expanding Fluid”,
WPCF 2014 Gyongyos, Hungary, 2014/08/25.
Liao, J: Jet Tomography of Fluctuating Initial Conditions
and the Opaqueness Evolution from RHIC to LHC”, Plenary Talk at ATHIC 2014 Osaka, Japan, 2014/08/06.
Liao, J: Probing QCD Physics with QED Fields”, XQCD
2014 Stony Brook, New York, USA, 2014/06/21.
Liao, J: In Search of Anomalous Transport Eﬀects in
Heavy Ion Collisions”, Simons Center Workshop on“Quantum Anomaly & Hydrodynamics” Stony Brook,- 468 -New York, USA, 2014/02/18.
Liao, J: The Initial Conditions in Heavy Ion Collisions”,
Plenary Session of STAR Collaboration Meeting at Feb
2014 BNL, New York, USA, 2014/02/13.
Lin, S: ”Photon suppression and dilepton enhancement insemi-QGP”, Quark Matter 2014 Darmstadt, Germany,
2014/05/19.
Lin, S: ”Photon suppression and dilepton enhancement insemi-QGP”, RBRC workshop: Thermal Photons andDileptons in Heavy-Ion Collisions Brookhaven National
Laboratory, Upton, NY, USA, 2014/08/22.
A. Monnai, B. Mueller: ”Collinear parton splittings forearly thermal and chemical equilibration”, Frontiers ofHadronic Physics: Brains Recirculate Two Brookhaven
National Laboratory, New York, USA, 2014/03/13.
A. Monnai: ”Eﬀects of quark chemical equilibration on
thermal photon v2 ”, Extreme QCD 2014 Stony Brook
University, New York, USA, 2014/06/21.
A. Monnai: ”Thermal photons from chemically nonequilibrated QCD medium”, Strong and Electroweak
Matter 2014 EPFL, Lausanne, Switzerland, 2014/07/17.
A. Monnai: ”Quark chemical equilibration for thermal
photon elliptic ﬂow”, Thermal Photons and Dileptons in
Heavy-Ion Collisions Brookhaven National Laboratory,
New York, USA, 2014/08/21.
A. Monnai: ”Elliptic ﬂow of thermal photons in chemically non-equilibrated QCD medium”, Particles and Nuclei International Conference 2014 Hamburg University,
Hamburg, Germany, 2014/08/25.
A. Monnai: ”Quark chemical equilibration and thermal photons in heavy-ion collisions”, RIKEN Symposium/iTHES Workshop ”Thermal Quantum Field Theory and Their Applications” RIKEN, Wako, Japan,
2014/09/05.
A. Monnai: ”Eﬀects of quark chemical equilibration on
thermal photon elliptic ﬂow”, Hot Quarks 2014 Almeria,
Andalucia, Spain, 2014/09/26.
Pitonyak, D: AN in proton-proton collisions and the role oftwist-3 fragmentation, Transversity Workshop Cagliari,
Italy, 2014/06/11.
Pitonyak, D: Transverse single-spin asymmetries inproton-proton collisions within collinear factorization,
QCD Evolution Workshop Santa Fe, NM, 2014/13/05.
Pitonyak, D: Towards an understanding of transverse
single-spin asymmetries in proton-proton collisions,
RBRC Brain Workshop BNL, Upton, NY, 2014/13/03.
Yee, H.-U: ”Status of Chiral Magnetic Wave in
Heavy Ion Collisions”, RHIC & AGS Users Meeting
Brookhaven National Laboratory, Upton New York,USA, 2014/06/17
Yee, H.-U: ”Chiral Magnetic and Vortical Eﬀects at Weak
Coupling”, Extreme QCD (XQCD) Stony Brook University, New York, USA, 2014/06/19
Yee, H.-U: ”Interplay of QCD with Electromagnetism in
Heavy-ion Collisions”, QCD Long Range Plan Town

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Hall Meeting Temple University, Philadelphia, Pennsylvania USA, 2014/09/15
Yee, H.-U: ”Aspects of Chiral Magnetic and VorticalEﬀects at Weak Coupling”, BNL Nuclear Seminars
Brookhaven National Laboratory, Upton New York,USA, 2014/10/17- 469 -

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONSRBRC Computing Group
Publications[Journal](Original Papers) *Subject to Peer Review
Thomas Blum, Masashi Hayakawa, and Taku Izubuchi, :”Hadronic light-by-light scattering contribution to themuon anomalous magnetic moment from lattice QCD”,
Physical Review Letters Volume 114 Issue 1 Article
012001, 2014/07/10 *Thomas Blum P.A. Boyle, N.H. Christ, J. Frison, N. Garron, R.J. Hudspith, T. Izubuchi, T. Janowski, C. Jung,
A. Juettner, C. Kelly, R.D. Kenway, C. Lehner, M.
Marinkovic, R.D. Mawhinney, G. McGlynn, D.J. Murphy, S. Ohta, A. Portelli, C.T. Sachrajda, A. Soni: ”Domain Wall QCD with Physical Quark Mass”, submitted
for publication in Physical Review D :, 2014/11/25
Norman H. Christ, Jonathan M. Flynn, Taku Izubuchi,
Taichi Kawanai, Christoph Lehner, Amarjit Soni,
Ruth S. Van de Water, Oliver Witzel, “B-meson
decay constants from 2+1-ﬂavor lattice QCD withdomain-wall light quarks and relativistic heavy quarks”,
Phys. Rev. D91:054502, 2015 (arXiv:1404.4670 [heplat])*.
Z. Bai, N.Y. Christ, T. Izubuchi, C.T. Sachrajda, and
A. Soni and J. Yu, “KL − KS Mass Diﬀerence from
Lattice QCD”, Phys. Rev. Lett., 113, 2014, 112003(arXiv:1406.0916 [hep-lat])*.
Y. Aoki, T. Ishikawa, T. Izubuchi, C. Lehner and A. Soni,“Neutral B meson mixings and B meson decay constants
with static heavy and domain-wall light quarks,” Phys.
Rev. D 91, no. 11, 114505 (2015) [arXiv:1406.6192 [heplat]].*T. Bhattacharya, M. I. Buchoﬀ, N. H. Christ, H.-T. Ding,
R. Gupta, C. Jung, F. Karsch and Z. Lin et al., “TheQCD phase transition with physical-mass, chiral quarks”
Phys. Rev. Lett. 113, 082001 (2014) [arXiv:1402.5175[hep-lat]]*.
Jung,C et al., SWME Collaboration: ”Improved determination of BK with staggered quarks” Phys. Rev. D89,
074504 (2014) arXiv:1402.0048 [hep-lat]*.
M. I. Buchoﬀ, M. Cheng, N. H. Christ, H.-T. Ding,
C. Jung, F. Karsch, Z. Lin and R. D. Mawhinney etal., ”The QCD chiral transition, u(1)A symmetry andthe Dirac spectrum using domain wall fermions” Phys.
Rev. D 89, 054514 (2014) [arXiv:1309.4149 [hep-lat]]*.
Z. S. Brown, W. Detmold, S. Meinel, K. Orginos:”Charmed bottom baryon spectroscopy from lattice
QCD”, Physical Review D Volume 90 Issue 9 Article
094507 Page 1-31, 2014/11/19 *Ethan Neil, Thomas Appelquist et al. (LSD Collaboration): “Two-color gauge theory with novel infraredbehavior”, Physical Review Letters Vol. 112, no. 11,111601 2014/03/18 *Ethan Neil, Alexei Bazavov et al. (Fermilab Lattice and- 470 -

MILC Collaborations): “Determination of |Vus | from alattice-QCD calculation of the K → πℓν semileptonic
form factor with physical quark masses”, Physical Review Letters Vol. 112, no. 11, 112001 2014/03/17 *Ethan Neil, Thomas Appelquist et al. (LSD Collaboration): “Composite bosonic baryon dark matter on thelattice: SU(4) baryon spectrum and the eﬀective Higgs
interaction”, Physical Review D Vol. 89, no. 9, 094508
2014/05/28 *Ethan Neil, Jon A. Bailey et al. (Fermilab Lattice andMILC Collaborations): “Update of |Vcb | from the B̄ →D∗ ℓν̄ form factor at zero recoil with three-ﬂavor lattice
QCD”, Physical Review D Vol. 89, no. 11, 114504
2014/06/19 *Ethan Neil, Richard C. Brower et al. (LSD Collaboration):“Maximum-Likelihood Approach to Topological Charge
Fluctuations in Lattice Gauge Theory”, Physical Review
D Vol. 90, no. 1, 014503 2014/07/09 *Ethan Neil, Alexei Bazavov et al. (LSD Collaboration):“Charmed and light pseudoscalar meson decay constantsfrom four-ﬂavor lattice QCD with physical light quarks”,
Physical Review D Vol. 90, no. 7, 074509 2014/10/30 *Ethan Neil, Thomas Appelquist et al. (LSD Collaboration): “Lattice simulations with eight ﬂavors of domain
wall fermions in SU(3) gauge theory”, Physical Review
D Vol. 90, no. 11, 114502 2014/12/12 *E. Shintani, R. Arthur, T. Blum, T. Izubuchi, C. Jungand C. Lehner, “Covariant approximation averaging,”,arXiv:1402.0244 [hep-lat], accepted by Physical Review
D*
J. Green, S. Meinel, M. Engelhardt, S. Krieg, J. Laeuchli,
J. Negele, K. Orginos, A. Pochinsky, S. Syritsyn: “Highprecision calculation of the strange nucleon electromagnetic form factors”, submitted to Physical Review D
arXiv:1505.01803, 2015/05/07
J.R. Green, M. Engelhardt, S. Krieg, J.W. Negele, A.V.
Pochinsky, S.N. Syritsyn: “Nucleon Structure from Lattice QCD Using a Nearly Physical Pion Mass”, PhysicalLetters B Volume 734 Pages 290-295, 2012/06/27 *J.R. Green, J.W. Negele, A.V. Pochinsky, S.N. Syritsyn,
M. Engelhardt, S. Krieg: “Nucleon electromagnetic form
factors from lattice QCD using a nearly physical pionmass”, Physical Review D Volume 90 Article 074507,
2014/04/15 *Lee, J-W, Tiburzi, B: ”Background electromagnetic ﬁelds
and nonrelativistic QED matching: Scalar case”, Physical Review D Volume 89 Issue 5 Article 054017 Page
1-15, 2014/03/17 *Tiburzi, B, : ”Neutron in a strong magnetic ﬁeld: Finite
volume eﬀects”, Physical Review D Volume 89 Issue 7
Article 074019 Page 1-22, 2014/04/08 *Tiburzi, B, : ”Finite volume eﬀects on the extraction ofform factors at zero momentum”, Physical Review D
Volume 90 Issue 5 Article 054508 Page 1-15, 2014/09/23*

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Lee, J-W, Tiburzi, B: ”Reconciling the lattice backgroundﬁeld method with nonrelativistic QED: Spinor case”,
Physical Review D Volume 90 Issue 7 Article 074036
Page 1-16, 2014/10/29 *Beane, S, Change, E, Cohen, S, Detmold, W, Lin, H-W,
Orginos, K, Parreno, A, Savage, M, Tiburzi, B: ”Magnetic moments of light nuclei from lattice quantum chromodynamics”, Physical Review Letters Volume 113 Issue 25 Article 252001 Page 1-5, 2014/12/16 *[Book, Proceedings](Original Papers)
Tom Blum, et al.: ”Hadronic contributions to the muon
anomalous magnetic moment Workshop. (g − 2)µ : Quovadis? Workshop. Mini proceedings”, arXiv:1407.4021.
N. Christ et al. [RBC and UKQCD Collaborations], “Calculating the KL − KS mass diﬀerence and ϵK to subpercent accuracy,” PoS LATTICE 2013, 397 (2014)
Norman H. Christ, “Weak interactions of kaons fromlattice QCD”, Proceedings, 11th International Conference on Hyperons, Charm and Beauty Hadrons(BEACH 2014) Birmingham, UK, July 21-26, 2014,
J.Phys.Conf.Ser. 556, 012005, 2014.
Tomomi Ishikawa, Yasumichi Aoki, Taku Izubuchi,
Christoph Lehner, Amarjit Soni: ”Neutral B meson mixing with static heavy and domain-wall light quarks”,
PoS LATTICE2013 (2014) 410 .
E. Shintani, H. J. Kim, T. Blum and T. Izubuchi, “Vacuum polarization function in Nf = 2 + 1 domain-wall
fermion,” PoS LATTICE 2013, 487 (2014).
T. Blum, M. Hayakawa and T. Izubuchi, “Update on the
hadronic light-by-light contribution to the muon g − 2
and inclusion of dynamically charged sea quarks,” PoS
LATTICE 2013, 439 (2014).
T. Blum et al. [RBC and UKQCD Collaborations], “WeakDecay Measurements from 2+1 ﬂavor DWF Ensembles,”
PoS LATTICE 2013, 404 (2014).
E. Shintani, T. Blum, A. Soni and T. Izubuchi, “Neutron
and proton EDM with Nf = 2+1 domain-wall fermion,”
PoS LATTICE 2013, 298 (2014).
H. J. Kim and T. Izubuchi, “Möbius domain wall fermion
method on QUDA,” PoS LATTICE 2013, 033 (2014).
S. Drury, T. Blum, M. Hayakawa, T. Izubuchi, C. Sachrajda, R. Zhou ”Non-degenerate light quark masses from
2+1f lattice QCD+QED “, PoS LATTICE2013 (2014)
268 .
Christopher Kelly, Daiqian Zhang: ”Lattice Measurementof the Delta I=1/2 Contribution to Standard Model Direct CP-Violation in K→pi pi Decays at Physical Kinematics: Part I ”, PoS(LATTICE2014)365 .
Christopher Kelly, Daiqian Zhang: ”Lattice Measurementof the Delta I=1/2 Contribution to Standard Model Direct CP-Violation in K→pi pi Decays at Physical Kinematics: Part II ”, PoS(LATTICE2014)366 .
Lin,M: ”Nucleon Form Factors with 2+1 Flavors of Domain Wall Fermions and All-Mode-Averaging” PoS- 471 -LATTICE2013 (2014) 275.
Lin,M et. al: ”Accelerating Ab Initio Nucleon Structure Calculations with All-Mode-Averaging on Gordon”
XSEDE2014 proceedings
R. R. Horgan, Z. Liu, S. Meinel, M. Wingate: ”Rare
B decays using lattice QCD form factors”, PoS LATTICE2014, 372 (2014).
Ethan Neil, Alexei Bazavov et al. (Fermilab Lattice andMILC Collaborations): “The Ds , D+ , Bs and B decay
constants from 2+1 ﬂavor lattice QCD”, PoS LATTICE
2013, 394 (2014) .
Ethan Neil, Elvira Gamiz et al. (Fermilab Lattice andMILC Collaborations): “Kaon semileptonic form factors
with Nf = 2 + 1 + 1 HISQ fermions and physical lightquark masses”, PoS LATTICE 2013, 395 (2014) .
Ethan Neil, Alexei Bazavov et al. (Fermilab Lattice andMILC Collaborations): “Charmed and strange pseudoscalar meson decay constants from HISQ simulations”, PoS LATTICE 2013, 405 (2014) .
Ethan Neil, Yuzhi Liu et al. (Fermilab Lattice and MILC
Collaborations): “Heavy-meson semileptonic decays for
the Standard Model and beyond”, PoS LATTICE 2013,
386 (2014) .
Ethan Neil, George Fleming: “From Lattice Strong Dynamics to Phenomenology”, Proceedings of the KMIGCOE Workshop on Strong Coupling Gauge Theories
in the LHC Perspective (SCGT 12), p. 58 (2014) .
Ethan Neil, Alexei Bazavov et al. (Fermilab Latticeand MILC Collaborations): “Charmed and light pseudoscalar meson decay constants from HISQ simulations”, PoS LATTICE 2014, 382 (2014) .
Ethan Neil, Jon A. Bailey et al. (Fermilab Lattice andMILC Collaborations): “B → πℓν semileptonic form
factors from unquenched lattice QCD and determinationof |Vub |”, PoS LATTICE 2014, 385 (2014) .
Ethan Neil, Thomas DeGrand, Yuzhi Liu, Yigal Shamir,
Benjamin Svetitsky: “Spectroscopy of SU(4) latticegauge theory with fermions in the two index antisymmetric representation”, PoS LATTICE 2014, 275(2014) .
Ohta, S, ”Systematics analyses on nucleon isovector observables in 2+1-ﬂavor dynamical domain-wall lattice
QCD near physical mass”, PoS LATTICE2014 (2015)
149
M. Engelhardt, Bernhard Musch, T. Bhattacharya, R.
Gupta, Ph.
Hagler, J. Negele, A. Pochinsky, A.
Schafer, S. Syritsyn, B. Yoon: “Nucleon transverse
momentum-dependent parton distributions from domain
wall fermion calculations at 297 MeV pion mass”, PoS
LATTICE2014 (2014) 167 .
S. Syritsyn, T. Blum, M. Engelhardt, J. Green, T.
Izubuchi, C. Jung, S. Krieg, M. Lin, S. Meinel, J. Negele:“Initial nucleon structure results with chiral quarks at
the physical point”, PoS LATTICE2014 (2015) 134 .

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONSSergey Syritsyn: “Review of Hadron Structure Calculations on a Lattice”, PoS LATTICE2013 (2014) 009 .
Tiburzi, B, : ”Volume eﬀects on the method of extracting
form factors at zero momentum”, PoS LATTICE2014(2015) 132
Lee, J-W, Tiburzi, B: ”Background ﬁeld method and nonrelativistic QED matching”, PoS LATTICE2014 (2015)
155
Oral Presentations(International Conference etc.)
Blum, T: ”Hadronic contributions to the muon g-2”, Conﬁnement XI (St. Petersburg) St. Petersburg, Russia,
2014/09/13.
Blum, T: ”Lattice calculation on the nucleon EDM”, BNL
HET lunch seminar BNL, USA, 2014/08/8.
Blum, T: ”Lattice calculations of the Hadronic contributions to the muon g-2”, 5th International Symposium on LEPTON MOMENTS Cape Cod, MA, USA,
2014/07/24.
Blum, T: ”Fundamental Parameters I: Quark Masses”,
FLAG-Mad, Instituto de Fı́sica Teórica UAM/CSIC
Madrid, Spain, 2014/05/24.
Blum, T: ”Summary and Perspectives of Lattice QCD”,
Hadronic contributions to the muon anomalous magnetic moment: strategies for improvements of the accuracy of the theoretical prediction UITP, Walthhausen
Castle, Mainz, Germany, 2014/04/05.
Christ, N: ”Chiral fermions and precision lattice ﬁeld theory”, PPCM 2014, Boston University, May 8-10, 2014
http://blogs.bu.edu/ppcm/
Christ, N: ”Computing K → pipi decay and the KL KS
mass diﬀerence using lattice QCD”, Southampton University, July 18, 2014.
Christ, N: “Computing K → pipi decay and the KL KS
mass diﬀerence using lattice QCD, the University of
Maryland, May 12, 2014.
Ishikawa, T: ”B meson decay constants and Delta B=2
matrix elements with static heavy and doma in-wall lightquarks”, 32nd International Symposium on Lattice Field
Theory (Lattice 2014) New York, USA, 2014/06/23-28.
Izubuchi, T: “Supercomputing Fundamental Particle &Nuclear Physics” BNL Lecture BNL, Upton, NY
September 2014
Izubuchi, T: “Lattice QCD calculations for particle
physics” XXVI IUPAP Conference on Computational
Physics Boston University,Boston, MA 2014/08/11-14.
Izubuchi, T: “Hadronic Light-by-Light: What can lattice
QCD achieve?”
Hadronic contributions to the muon anomalous magnetic moment: strategies for improvements of the accuracy of the theoretical prediction Waldthausen Castle
near Mainz, Germany 2014/04/02.
Izubuchi, T: “Hadronic Vacuum Polarization for muon g2” Lattice QCD Meets Experiment 2014 Fermi National- 472 -

Laboratory, Batavia, IL 2014/03/08.
Christopher Kelly: ”Light hadronic physics from lattice
QCD at the physical point”, RBRC lunch seminar BNL,
Upton, NY, USA, 2014/01/31.
Christopher Kelly: ”New horizons in kaon physics on thelattice”, USQCD all-hands meeting presentation JLAB,
Newport News, VA, USA, 2014/04/18.
Christopher Kelly: ”Lattice Measurement of the Delta
I=1/2 Contribution to Standard Model Direct CPViolation in K→pi pi Decays at Physical Kinematics:
Part I”, Lattice 2014 parallel talk Columbia University,
NY, USA, 2014/06/23.
Christopher Kelly: ”Lattice Measurement of the Delta
I=1/2 Contribution to Standard Model Direct CPViolation in K→pi pi Decays at Physical Kinematics”, Seminar University of Edinburgh, Edinburgh, UK,
2014/09/29.
Lehner, C ”Perspectives in lattice B physics”
HET/RIKEN Lunch Seminar BNL, Upton, NY
2014/02/07
Lehner, C ”Towards the large volume limit” Lattice 2014
New York, NY 2014/06/27
Lehner, C ”Analytic Methods for Precise Predictions” Lattice Meets Continuum Siegen, Germany 2014/10/01
Lehner, C ”Bloch’s theorem and QCD+QED simulations”
HET lunch seminar BNL,Upton, NY 2014/11/21
Lin, M ”Nucleon structure on the lattice: Approaching
the physical limit” High Energy Theory/RIKEN Lunch
Seminar BNL,Upton,NY 2014/03/28
Lin, M ”Computational Issues in BSM Theories Past,
Present and Future” Field Theoretic Computer Simulations for Particle Physics and Condensed Matter Boston
University Center for Computational Science Boston,
MA 2014/05/08
Lin, M Multigrid HMC” The Eighth International Workshop on Numerical Analysis and Lattice QFT Yale University, Yale, CT. 2014/06/20
Lin, M ”Application of Adaptive Multigrid Algorithm
in Hybrid Monte Carlo Simulations” The 32nd International Symposium on Lattice Field TheoryColumbia
University, NY 2014/06/23
S. Meinel: ”Lattice QCD and the search for new physics
using beauty quarks”, APS Four Corners Section Meeting, Utah Valley University, Utah, 2014/10/18.
Ethan Neil: ”Bayesian Methods for Parameter Estimationfrom LAttice Simulations”, Eighth International Workshop on Numerical Analysis and Lattice QFT, Yale University, New Haven, CT 2014/06/21
Ethan Neil: ”Leptonic B and D decay constants with 2+1
ﬂavor asqtad fermions”, XXXII International Symposium on Lattice Field Theory, Columbia University, New
York, NY 2014/06/25
Shintani,E ”Accurate calulation of nucleon form factor inlattice QCD” the 4th Joint Meeting of the APS Division3

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)of Nuclear Physics and the Physical Society of JapanOctober 7-11, 2014 Waikoloa, Hawaii.
Shintani,E ”Symmetry on honeycomb lattice formulation”, 11th Quark conﬁnement and Hadron spectrum
XI, 7-12 September 2014, St. Petersburg.
Shintani,E ”Progress of lattice calculation of light-by-lightcontribution to muon g-2”, 37th international conferenceon high energy physics, 2 - 9 July 2014, Valencia, Spain.
Shintani,E ”Hadronic contributions to the muon anomalous magnetic moment: strategies for improvements of
the accuracy of the theoretical prediction”, Working
group in lattice QCD, MITP workshop, 1-5 April 2014,
Waldthausen Castle near Mainz.
Shintani,E ”αs from the lattice”, High precision fundamental constants at the TeV scale, March 10-21, 2014,
JGU Campus Mainz.
Shintani,E”Lattice calculation of nucleon EDM”,
Hirschegg 2014, Hadrons from Quarks and Gluons, International Workshop XLII on Gross Properties of Nuclei and Nuclear Excitations, Hirschegg, Kleinwalsertal,
Austria, January 12 - 18, 2014.
S. Syritsyn: “Nucleon Matrix Elements From Lattice
QCD”, INT Workshop INT-14-57W “Nuclear Aspectsof Dark Matter Searches” USA, Seattle, University ofWashington, 2014/12/10-12.
S. Syritsyn: “Nucleon Structure and Spin From Lattice
QCD: Review”, 4th Joint Meeting APS & JPS Nuclear
Physics Divisions USA, Hawaii, 2014/10/7-11.
S. Syritsyn: “Nucleon Structure on a Lattice at the Physical Point”, CCP 2014 USA, Boston, Boston University,
2014/08/11-14.
S. Syritsyn: “Initial Nucleon Structure Results with Chiral
Quarks at the Physical Point”, Lattice 2014 USA, New
York, Columbia University, 2014/06/23-28.
S. Syritsyn: “Nucleon Structure on a Lattice : Present andFuture Computing Requirements”, Large Scale Computing and Storage Requirements for Nuclear Physics : Target 2017 USA, Bethesda, MD, 2014/04/29.
S. Syritsyn: “QCD on a Lattice : Nucleon Structure
and Beyond”, High Energy/Nuclear Seminar USA, East
Lansing, Michigan State University, 2014/04/30.
Tiburzi, B:, ”Neutron in a strong magnetic ﬁeld and eﬀects
from ﬁnite volume”, Theory seminar Maryland Center
for Fundamental Physics, College Park, Maryland USA
2014/03/13
Tiburzi, B:, ”Neutron in a strong magnetic ﬁeld and eﬀects
from ﬁnite volume”, Theory seminar College of William
and Mary, Williamsburg, Virginial USA 2014/03/13
Tiburzi, B:, ”A smaller size for the proton?”, Physics department colloquium Amherst College, Amherst, Massachusetts USA 2014/04/03
Tiburzi, B:, ”Four lectures on eﬀective ﬁeld theories”, National nuclear physics summer school College of William
and Mary, Williamsburg, Virginia USA 2014/06/09

Tiburzi, B:, ”Towards exploring parity violation with lattice QCD”, Workshop on Bound states and resonances in
eﬀective ﬁeld theories and lattice QCD calculations Centro de Ciencias de Benasque Pedro Pascual, Benasque,
Spain 2014/07/30
Tiburzi, B:, ”The prospects for two-photon physics withlattice QCD”, Town Hall Meeting, American PhysicalSociety, Division of Nuclear Physics Temple University,
Philadelphia, Pennsylvania USA 2014/09/14(Domestic Conference etc.)
Izubuchi, T: “Study of the nucleon structure by lattice QCD” Physical Society of Japan Joint symposium
among experimental nuclear, theoretical nuclear , experimental particle, and theoretical particle physics, Latest
results and future programs on the nucleon structure Toward an understanding of the nucleon spin - JPS Symposium Tokai University, Kanagawa, Japan 2014/03/30
Poster Presentations(International Conference etc.)
Shintani, E ”Precise lattice calculation of nucleon form
factor with all-mode-averaging”, 11th Quark conﬁnement and Hadron spectrum XI, 7-12 September 2014,
St. Petersburg.
Shintani, E ”Improved statistics of proton decay matrix
element”, the 32st International Symposium on Lattice
Field Theory 23-28 June 2014, Columbia University, NY
Shintani, E ”Error reduction with all-mode-averaging in
Wilson fermion”, the 32st International Symposium on
Lattice Field Theory, 23-28 June 2014, Columbia University, NY.
T.Blum T. Izubuchi (for USQCD Collaboration), “Allmode averaging and calculations of the muon anomalous magnetic moment, (g − 2)µ ”, SciDAC PI meeting,
September 2014, Washington D.C., MD- 473 -

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS√
at sN N =200 GeV”, Phys. Rev. C 91, 014907 (2015).
*
Adare A., et al. PHENIX Collaboration, “Charged-pioncross sections and double-helicity asymmetries in polar√
ized p+p collisions at s = 200 GeV”, Phys. Rev. D
91, 032001 (2015). *Adare A., et al. PHENIX Collaboration, “Measurement of
the Upsilon(1S+2S+3S) production in p+p and Au+Au√
collisions at sN N = 200 GeV”, Phys. Rev. C 91,
024913 (2015). *Adare A., et al. PHENIX Collaboration, “Search for dark
photons from neutral meson decays in p+p and d+Au√
collisions at sN N = 200 GeV”, Phys. Rev. C 91,
031901 (2015). *E.C Aschenauer, K. Boyle, et al. “eRHIC Design Study:
An Electron-Ion Collider at BNL”, arXiv:1409.1633.
Chin-Hao Chen “Studying the Early Universe via QuarkGluon Plasma”, Nucl. Phys. Proc. Suppl. 246-247(2014) 38-41.
A.Bzdak, V. Sokov and S. Bathe “Centrality dependenceof high energy jets in p+Pb collisions at the LHC”,
arXiv:1408.3156.
C.Aidala, et al. “The PHENIX Forward Silicon Vertex
Detector”, Nucl. Instrum. Meth. A755 (2014) 44.*
Seidel R, PHENIX W to mu measurements in polarized proton-proton collisions, PoS DIS2014(2014) 205,
2014/07/16
Kanesue T, Fuwa Y, Kondo K, Okamura M, ”Laser ion
source with solenoid ﬁeld”, APPLIED PHYSICS LETTERS, 105, 193506 (2014) *Okamura M, Sekine M, Ikeda S, Kanesue T, Kumaki M, Fuwa Y, ”Preliminary result of rapid
solenoid for controlling heavy-ion beam parametersof laser ion source”, Laser and Particle Beams,
doi:10.1017/S026303461500004X (2015) *RBRC Experimental Group
Publications[Journal](Original Papers) *Subject to Peer Review
Adare A., et al. PHENIX Collaboration, “Heavy-ﬂavor
electron-muon correlations in p+p and d+Au collisions√
at s = 200 GeV”, Phys. Rev. C 89, 034915 (2015). *Adler S. S., et al. PHENIX Collaboration, “Transverseenergy distributions at midrapidity in p+p, d+Au, and√
Au+Au collisions at sN N =62.4 - 200 GeV and implications for particle-production models”, Phys. Rev. C
89, 044805 (2014). *Adare A., et al. PHENIX Collaboration, “Azimuthalangle dependence of charged-pion-interferometry measurements with respect to 2nd and 3rd-order event plane√in Au+Au collisions at sN N = 200 GeV”, Phys. Rev.
Lett. 112, 222301 (2014). *Adare A., et al. PHENIX Collaboration, “Cold nuclearmatter eﬀects on heavy-quark production at forward and√backward rapidities in d+Au collisions at sN N =200
GeV”, Phys. Rev. Lett. 112, 252301 (2014). *Adare A., et al. PHENIX Collaboration, “Measurement oftransverse-single-spin asymmetries for midrapidity andforward-rapidity production of hadrons in polarized p+p√
collisions at s = 200 and 62 GeV”, Phys. Rev. D 90,
012006 (2014). *Adare A., et al. PHENIX Collaboration, “Inclusive
Double-Helicity Asymmetries in Neutral-Pion and Eta√
Meson Production in p+p Collisions at s = 200 GeV”,
Phys. Rev. D 90, 012007 (2014). *Adare A., et al. PHENIX Collaboration, “System-size dependence of open-heavy-ﬂavor production in nucleus√
nucleus collisions at sN N =200 GeV”, Phys. Rev. C
90, 034903 (2014). *Adare A., et al. PHENIX Collaboration, “Centrality Categorization for Rp (d) + A in high-energy collisions”,
Phys. Rev. C 90, 034902 (2014). *Adare A., et al. PHENIX Collaboration, “Low-Mass
Vector-Mesons Production at forward rapidity in p+p√
Collisions at s = 200 GeV”, Phys. Rev. D 90, 052002(2014). *Adare A., et al. PHENIX Collaboration, “Cross Section
and Transverse Single-Spin Asymmetry of η Mesons in√p↑ + p collisions at s = 200 GeV at Forward Rapidity”,
Phys. Rev. D 90, 072008 (2014). *Adare A., et al. PHENIX Collaboration, “Measurementof K 0S and K ∗0 in p+p, d+Au and Cu+Cu collisions at√
sN N = 200 GeV”, Phys. Rev. C 90, 054905 (2014). *Adare A., et al. PHENIX Collaboration, “Nuclear mattereﬀects on J/psi production in asymmetric Cu+Au col√lisions at sN N =200GeV”, Phys. Rev. C 90, 064908(2014). *Adare A., et al. PHENIX Collaboration, “Cross-section
for barb production via dielectrons in d+Au collisions(Review) *Subject to Peer Review
Akiba Y, ”Quest for the quark-gluon plasma — hard andelectromagnetic probles”, Progress of theoretical and experimental physics 03A105(2015), 2015/01/12 *[Book・Proceedings](Original Papers)
Kanesue T, et al. ”THE COMMISSIONING OF THE
LASER ION SOURCE FOR RHIC EBIS”, Proceedingsof IPAC 2014 (ISBN 978-3-95450-132-8), p1890-1892
Ikeda S, et al., ”Control of Plasma Flux with Pulsed
Solenoid for Laser Ion Source”, Proceedings of IPAC
2014, (ISBN 978-3-95450-132-8), p601-603
Fuwa Y, et al., ”Beam dynamics of multi charge state ionsin RFQ linac”, Proceedings of LINAC 2014 (ISBN 9783-95450-142-7), p317-319
Okamura M, et al., ”Low Charge Laser Ion Source for the
EBIS injector”, Proceedings of LINAC 2014 (ISBN 9783-95450-142-7), p64-66- 474 -

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)(Review)
秋葉康之, クォーク・グルーオン・プラズマの物理 (共立出版), ISBN 978-4-320-03523-2, 2014/4/15

Oral Presentations(International Conference etc.)
Yasuyuki Akiba, ”Future plan at BNL”, Hadron physics
symposium (科研費新学術領域「新ハドロン」), Nagoya,Japan, 2014/4/18
Yasuyuki Akiba, ”Electromagnetic probes and heavy flavor from RHIC and LHC”, Hawaii 2014 (Fourth Joint
Meeting of the Nuclear Physics Division of the American Physical Society and the Physical Society of Japan)(APS/JPS), Waikoloa Village, HI, USA, 2014/10/7
Ralf Seidl, ”W to mu measurements at PHENIX”, Conference on Deep inelastic scattering and related topics ,Warsaw, Poland, 2014/05/29
T. Kanesue, ”THE COMMISSIONING OF THE LASERION SOURCE FOR RHIC EBIS”, 5th International
Particle Accelerator Conference (Cockcroft Inst. and
U. Liverpool), Dresden, Germany, 2014/06/15-16
Y. Fuwa, ”Charge-State Selective Ion Beam Acceleration with RFQ Linac”, 20th International Symposium
on Heavy-Ion Inertial Fusion (IMP), Lanzhou, China,
2014/08/11-15
T. Kanesue, ”Stable operation of Laser Ion Source for low
charge state ion production”, 20th International Symposium on Heavy-Ion Inertial Fusion (IMP), Lanzhou,
China, 2014/08/11-15
Shunsuke Ikeda, ”Control of plasma flux with pulsedsolenoid for laser ion source”, 5th International Particle
Accelerator Conference (Cockcroft Inst. and U. Liverpool), Dresden, Germany, 2014/06/15-16
M. Okamura, ”Preliminary result of rapid solenoid for controlling heavy-ion beam parameters of laser ion source”,
20th International Symposium on Heavy-Ion Inertial Fusion (IMP), Lanzhou, China, 2014/08/11-15
Y. Fuwa, ”Beam dynamics of multi charge state ionsin RFQ linac”, 27th Linear Accelerator Conference(CERN), Geneva, Switzerland, 2014/08/31-09/05
M. Okamura, ”Low Charge Laser Ion Source for the EBIS
injector”, 27th Linear Accelerator Conference (CERN),
Geneva, Switzerland, 2014/08/31-09/05
Shunsuke Ikeda, ”Influence of solenoidal magnetic field on
laser ablation plasma”, 5th Euro-Asian Pulsed Power
Conference (Kumamoto Univ.), Kumamoto, Japan,
2014/09/11
Masafumi Kumaki, ”Proton beam generation using Aucoated plastic target from Laser Ion Source” 19th International Conference on Ion Beam Modification of Materials, Leuven, Belgium, 2014/09/14-19
Yusuke Komatsu, ”Development of a Tracking and Electron Identification System Using GEM for the J-PARC

E16 Experiment”, IEEE NUCLEAR SCIENCE SYMPOSIUM 2014 (IEEE), Seattle, USA, 2014/11/08-15(Domestic Conference etc.)
秋葉康之, ”RHIC PHENIX 実験とその将来計画”, 第１回
CiRfSE ワークショップ (筑波大学数理物質融合科学センター), 筑波大学、つくば市, 2015/3/12
池田峻輔, ” レーザーアブレーションプラズマに対するパルス磁場の影響”, 日本物理学会第 70 回年次大会, 早稲田大
学、東京, 2015/3/21-24
熊木雅史” ピコ秒レーザーを用いたレーザーイオン源開発” 日 本 物 理 学 会 第 70 回 年 次 大 会 早 稲 田 大 学 、東 京
2015/3/21-24- 475 -

2

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONSRadioactive Isotope Physics Laboratory
Publications[Journal](Original Papers)*Subject to Peer Review
Takechi M., Suzuki S., Nishimura D., Fukuda M., OhtsuboT., Nagashima M., Suzuki T., Yamaguchi T., Ozawa A.,
Moriguchi T., Ohishi H., Sumikama T., Geissel H., Aoi
N., Chen Rui-Jiu Fang De-Qing Fukuda N., Fukuoka S.,
Furuki H., Inabe N., Ishibashi Y., Itoh T., Izumikawa T.,
Kameda D., Kubo T., Lantz M., Lee C., S., Ma Yu-Gang
Matsuta K., Mihara M., Momota S., Nagae D., NishikioriR., Niwa T., Ohnishi T., Okumura K., Ohtake M., Ogura
T., Sakurai H., Sato K., Shimbara Y., Suzuki H., Takeda
H., Takeuchi S., Tanaka K., Tanaka M., Uenishi H.,
Winkler M., Yanagisawa Y., Watanabe S., Minomo K.,
Tagami S., Shimada M., Kimura M., Matsumoto T.,
Shimizu Y., R., Yahiro M.: “Evidence of halo structure in
Mg-37 observed via reaction cross sections and intruder
orbitals beyond the island of inversion”, Phys. Rev. C 90.
61305 (2014).
Patel Z., Soederstroem P.-A., Podolyak Zs., Regan P. H.,
Walker P. M., Watanabe H., Ideguchi E., Simpson G. S.,
Liu H. L., Nishimura S., Wu Q., Xu F. R., Browne F.,
Doornenbal P., Lorusso G., Rice S., Sinclair L.,
Sumikama T., Wu J., Xu Z. Y., Aoi N., Baba H., Garrote
F. L., Bello Benzoni G., Daido R., Fang Y., Fukuda N.,
Gey G., Go S., Gottardo A., Inabe N., Isobe T., Kameda
D., Kobayashi K., Kobayashi M., Komatsubara T.,
Kojouharov I., Kubo T., Kurz N., Kuti I., Li Z.,
Matsushita M., Michimasa S., Moon C. -B., Nishibata H.,
Nishizuka I., Odahara A., Sahin E., Sakurai H.,
Schaffner H., Suzuki H., Takeda H., Tanaka M.,
Taprogge J., Vajta Zs., Yagi A., Yokoyama R.: “Isomer
Decay Spectroscopy of Sm-164 and Gd-166: Midshell
Collectivity Around N=100”, Phys. Rev. Lett. 113,262502 (2014).
Doornenbal P., Takeuchi S., Aoi N., Matsushita M.,
Obertelli A., Steppenbeck D., Wang H., Audirac L., Baba
H., Bednarczyk P., Boissinot S., Ciemala M., Corsi A.,
Furumoto T., Isobe T., Jungclaus A., Lapoux V., Lee J.,
Matsui K., Motobayashi T., Nishimura D., Ota S.,
Pollacco E. C., Sakurai H., Santamaria C., Shiga Y.,
Sohler D., Taniuchi R.: “Intermediate-energy Coulomb
excitation of Sn-104: Moderate E2 strength decrease
approaching Sn-100”, Phys. Rev. C. 90, 61302 (2014).
Tshoo K., Satou Y., Bertulani C. A., Bhang H., Choi S.,
Nakamura T., Kondo Y., Deguchi S., Kawada Y.,
Nakayama Y., Tanaka K. N., Tanaka N., Togano Y.,
Kobayashi N., Aoi N., Ishihara M., Motobayashi T., Otsu
H., Sakurai H., Takeuchi S., Yoneda K., Delaunay F.,
Gibelin J., Marques F., M., Orr N., A., Honda T.,
Kobayashi T., Sumikama T., Miyashita Y., Yoshinaga K.,
Matsushita M., Shimoura S., Sohler D., Hwang J. W.,
Zheng T., Li Z. H., Cao Z. X. :“Neutron occupancy of the 0d(5/2) orbital and the N=16
shell closure in O-24”, Phys. Lett.B 739, 19-22 (2014).

Yang Xiaofei, Furukawa Takeshi, Wakui Takashi, Fujita
Tomomi, Imamura Kei, Mitsuya Yosuke, Hayasaka Miki,
Ichikawa Yuichi, Ishibashi Yoko, Shirai Hazuki, Suzuki
Takahiro, Ebara Yuta, Hatakeyama Atsushi, Wada
Michiharu, Sonoda Tetsu, Ito Yuta, Kobayashi Tohr,uNishimura Shunji, Kurata-Nishimura Mizuki, Kondo
Yosuke, Yoneda Ken-Ichiro, Kubono Shigeru, Ohshiro
Yoshimitsu, Ueno Hideki, Shinozuka Tsutomu, Shimoda
Tadashi, Asahi Koichiro, Matsuo Yukari: “Laser-radiofrequency double-resonance spectroscopy of Rb84-87
isotopes trapped in superfluid helium”, Phys. Rev. A 90
52516 (2014).
Taprogge J., Jungclaus A., Grawe H., Nishimura S., Xu Z.,
Y., Doornenbal P., Lorusso G., Nacher E., Simpson G. S.,
Soederstroem P. -A., Sumikama T., Baba H., Browne F.,
Fukuda N., Gernhauser R., Gey G., Inabe N., Isobe T.,
Jung H. S., Kameda D., Kim G. D., Kim Y. -K.,
Kojouharov I., Kubo T., Kurz N., Kwon Y. K., Lin Z.,
Sakurai H., Schaffner H., Steiger K., Suzuki H., Takeda
H., Vajta Zs., Watanabe H., Wu J., Yagi A., Yoshinaga
K., Benzoni G., Boenig S., Chae K. Y., Coraggio L.,
Covello A., Daugas J. -M., Drouet F., Gadea A., Gargano
A., Ilieva S., Kondev F. G., Kroell T., Lane G. J.,
Montaner-Piza A., Moschner K., Muecher D., Naqvi F.,
Niikura M., Nishibata H., Odahara A., Orlandi R., PatelZ., Podolyak Zs., Wendt A.: “Identification of amillisecond isomeric state in Cd-129(81) via thedetection of internal conversion and Compton electrons”,
Phys. Lett.B 738 223-227 (2014).
Wendt A., Taprogge J., Reiter P., Golubev P., Grawe H.,
Pietri S., Boutachkov P., Algora A., Ameil F., Bentley M.
A., Blazhev A., Bloor D., Bondili N. S., Bowry M., BraccoA., Braun N., Camera F., Cederkall J., Crespi F., de la
Salle A., DiJulio D., Doornenbal P., Geibel K., GellankiJ., Gerl J., Grebosz J., Guastalla G., Habermann T.,
Hackstein M., Hoischen R., Jungclaus A., Merchan E.,
Million B., Morales A., Moschner K., Podolyak Zs.,
Pietralla N., Ralet D., Reese M., Rudolph D., Scruton L.,
Siebeck B., Warr N., Wieland O., Wollersheim H. J.:,
“Isospin symmetry in the sd shell: Transition strengths
in the neutron-deficient sd shell nucleus Ar-33”, Phys.
Rev. C 90 54301 (2014).
Simpson G. S., Gey G., Jungclaus A., Taprogge J.,
Nishimura S., Sieja K., Doornenbal P., Lorusso G.,
Soederstroem P. -A., Sumikama T., Xu Z.Y., Baba H.,
Browne F., Fukuda N., Inabe N., Isobe T., Jung H.S.,
Kameda D., Kim G. D., Kim Y. -K., Kojouharov I., Kubo
T., Kurz N., Kwon Y. K., Li Z., Sakurai H., Schaffner
H., Shimizu Y., Suzuki H., Takeda H., Vajta Z.,
Watanabe H., Wu J., Yagi A., Yoshinaga K., Boenig S.,
Daugas J. -M., Drouet F., Gernhaeuser R., Ilieva S.,
Kroell T., Montaner-Piza A., Moschner K., Muecher D.,
Naidja H., Nishibata H., Nowacki F., Odahara A.,
Orlandi R., Steiger K., Wendt A.: “Yrast 6(+) Seniority
Isomers of Sn-136,Sn-138”, Phys. Rev. Lett. 113, 132502(2014).
Jung H. S., Lee C. S., Kwon Y. K., Moon J. Y., Lee J. H.,- 476 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Yun C. C., Kim M. J., Hashimoto T., Yamaguchi H., Kahl
D., Kubono S., Wakabayashi Y., Togano Y., Choi Seonho,
Kim Y. H., Kim Y. K., Park J. S., Kim E. J., Moon C. -B.,
Teranishi T., Iwasa N., Yamada T., Kato S., CherubiniS., Hayakawa S., Rapisarda G. G.: “Elastic scattering of
Al-25 + p to explore the resonance structure in Si-26”,
Phys. Rev. C 90, 35805 (2014).
Lee Jenny, Pang Dan-Yang, Han Yin-Lu, Tsang, M. B.:“Proton Spectroscopic Factors Deduced from Helium-3
Global Phenomenological and Microscopic Optical Model
Potentials”, Chin. Phys. Lett. 31, 92103 (2014).
Watanabe H., Lorusso G., Nishimura S., Otsuka T., Ogawa
K., Xu Z.Y., Sumikama T., Soederstroem P. -A.,
Doornenbal P., Li Z., Browne F., Gey G., Jung H. S.,
Taprogge J., Vajta Zs., Wu J., Yagi A., Baba H., BenzoniG., Chae K. Y., Crespi F. C. L., Fukuda N., Gernhaeuser
R., Inabe N., Isobe T., Jungclaus A., Kameda D., Kim G.
D., Kim Y. K., Kojouharov I., Kondev F. G., Kubo T.,
Kurz N., Kwon Y. K., Lane G. J., Moon C. -B., MontanerPiza A., Moschner K., Naqvi F., Niikura M., Nishibata
H., Nishimura D., Odahara A., Orlandi R., Patel Z.,
Podolyak Zs., Sakurai H., Schaffner H., Simpson G. S.,
Steiger K., Suzuki H., Takeda H., Wendt A., Yoshinaga
K.: Monopole-Driven Shell Evolution below the Doubly
Magic Nucleus Sn-132 Explored with the Long-Lived
Isomer in Pd-126”, Phys. Rev. Lett. 113 042502 (2014).
Xu Z. Y., Nishimura S., Lorusso G., Browne F., Doornenbal
P., Gey G., Jung, H. -S., Li Z., Niikura M., Soederstroem
P. -A., Sumikama T., Taprogge J., Vajta Zs., Watanabe
H., Wu J., Yagi A., Yoshinaga K., Baba H., Franchoo S.,
Isobe T., John P. R., Kojouharov I., Kubono S., Kurz N.,
Matea I., Matsui K., Mengoni D., Morfouace P., Napoli
D. R., Naqvi F., Nishibata H., Odahara A., Sahin E.,
Sakurai H., Schaffner H., Stefan I. G., Suzuki D.,
Taniuchi R., Werner V.: “beta-Decay Half-Lives of Co76,Co-77, Ni-79,Ni- 80, and Cu-81: Experimental
Indication of a Doubly Magic Ni-78”, Phys. Rev. Lett. 113
32505 (2014).
Kobayashi N., Nakamura T., Kondo Y., Tostevin J. A.,
Utsuno Y., Aoi N., Baba H., Barthelemy R., Famiano M.
A., Fukuda N., Inabe N., Ishihara M., Kanungo R., Kim
S., Kubo T., Lee G. S., Lee H. S., Matsushita M.,
Motobayashi T., Ohnishi T., Orr N. A., Otsu H., OtsukaT., Sako T., Sakurai H., Satou Y., Sumikama T., Takeda
H., Takeuchi S., Tanaka R., Togano Y., Yoneda K.:“Observation of a p-Wave One-Neutron Halo
Configuration in Mg-37”, Phys. Rev. Lett. 112, 242501(2014).
Michimasa S., Yanagisawa Y., Inafuku K., Aoi N., Elekes
Z., Fueloep Zs., Ichikawa Y., Iwasa N., Kurita K.,
Kurokawa M., Machida T., Motobayashi T., Nakamura
T., Nakabayashi T., Notani M., Ong H., J., Onishi T., K.,
Otsu H., Sakurai H., Shinohara M., Sumikama T.,
Takeuchi S., Tanaka K., Togano Y., Yamada K.,
Yamaguchi M., Yoneda K.: “Quadrupole collectivity inisland-of-inversion nuclei Ne-28,Ne-30 and Mg-34,Mg36”, Phys. Rev. C 89, 54307 (2014).

Doornenbal P., Scheit H., Takeuchi S., Utsuno Y., Aoi N.,
Li K., Matsushita M., Steppenbeck D., Wang H., Baba
H., Ideguchi E., Kobayashi N., Kondo Y., Lee J.,
Michimasa S., Motobayashi T., Otsuka T., Sakurai H.,
Takechi M., Togano Y., Yoneda K.: “Rotational levelstructure of sodium isotopes inside the island of
inversion”, Progr. Theor. Exp. Phys. 053D01 (2014).
Crawford H. L., Fallon P., Macchiavelli A. O., Clark R. M.,
Brown B. A., Tostevin J. A., Bazin D., Aoi N., Doornenbal
P., Matsushita M., Scheit H., Steppenbeck D., Takeuchi
S., Baba H., Campbell C. M., Cromaz M., Ideguchi E.,
Kobayashi N., Kondo Y., Lee G., Lee I. Y., Lee J., Li K.,
Michimasa S., Motobayashi T., Nakamura T., Ota S.,
Paschalis S., Petri M., Sako T., Sakurai H., Shimoura S.,
Takechi M., Togano Y., Wang H., Yoneda K.: “Shell andshape evolution at N=28: The Mg-40 ground state”, Phys.
Rev. C 89, 41303 (2014).
Yang Z. H., Ye Y. L., Li Z. H., Lou J. L., Wang J. S.,
Jiang D. X., Ge Y. C., Li Q. T., Hua H., Li X. Q., Xu F.
R., Pei J. C., Qiao R., You H. B., Wang H., Tian Z. Y., Li
K. A., Sun Y. L., Liu H. N., Chen J., Wu J., Li J., Jiang
W., Wen C., Yang B., Yang Y. Y., Ma P., Ma J. B., Jin
S. L., Han J. L., Lee J.: “ Observation of Enhanced
Monopole Strength and Clustering in Be-12 ”,
Phys. Rev. Lett. 112, 162501 (2014).
Nakamura T., Kobayashi N., Kondo Y., Satou Y., TostevinJ., A., Utsuno Y., Aoi N., Baba H., Fukuda N., Gibelin J.,
Inabe N., Ishihara M., Kameda D., Kubo T.,
Motobayashi T., Ohnishi T., Orr N., A., Otsu H., OtsukaT., Sakurai H., Sumikama T., Takeda H., Takeshita E.,
Takechi M., Takeuchi S., Togano Y., Yoneda K.:“Deformation-Driven p-Wave Halos at the Drip Line:
Ne-31”, Phys. Rev. Lett. 112, 142501 (2014)
Taprogge J., Jungclaus A., Grawe H., Nishimura S.,
Doornenbal P., Lorusso G., Simpson G., S.,
Soederstroem P., -A., Sumikama T., Xu Z., Y., Baba H.,
Browne F., Fukuda N., Gernhaeuser R., Gey G., InabeN., Isobe T., Jung H., S., Kameda D., Kim G., D., Kim Y.,-K., Kojouharov I., Kubo T., Kurz N., Kwon Y., K., Li Z.,
Sakurai H., Schaffner H., Steiger K., Suzuki H., Takeda
H., Vajta Zs., Watanabe H., Wu J., Yagi A., Yoshinaga
K., Benzoni G., Boenig S., Chae K., Y., Coraggio L.,
Covello A., Daugas J., -M., Drouet F., Gadea A., Gargano
A., Ilieva S., Kondev F., G., Kroell T., Lane G., J.,
Montaner-Piza A., Moschner K., Muecher D., Naqvi F.,
Niikura M., Nishibata H., Odahara A., Orlandi R., PatelZ., Podolyak Zs., Wendt A.: “1p(3/2) Proton-Hole State in
Sn-132 and the Shell Structure Along N=82”, Phys. Rev.
Lett.112, 132501 (2014).
Wang He, Aoi Nori, Takeuchi Satoshi, Matsushita
Masafumi, Doornenbal Pieter, Motobayashi Tohru,
Steppenbeck David, Yoneda Kenichiro, Baba Hidetada,
Dombradi Zsolt, Kobayashi Kota, Kondo Yosuke, Lee
Jenny, Liu Hong-Na, Minakata Ryogo, Nishimura Daiki,
Otsu Hideaki, Sakurai Hiroyoshi, Sohler Dora, Sun YeLei, Tian Zheng-Yang, Tanaka Ryuki, Vajta Zsolt, Yang
Zai-Hong, Yamamoto Tetsuya, Ye Yan-Lin, Yokoyama- 477 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Rin: “ Structure of Sn-136 and the Z=50 magicity ”, Progr.
Theor. Exp. Phys., 023D02 (2014).
Danielewicz Pawel, Lee Jenny : “Symmetry energy II:
Isobaric analog states”, Nucl. Phys. A 922, 1-70 (2014).
Obertelli A., Delbart A., Anvar S., Audirac L., Authelet G.,
Baba H., Bruyneel B., Calvet D., Chateau F., Corsi A.,
Doornenbal P., Gheller J. -M., Giganon A., LahondeHamdoun C., Leboeuf D., Loiseau D., Mohamed A., Mols
J. -Ph., Otsu H., Peron C., Peyaud A., Pollacco E. C.,
Prono G., Rousse J. -Y., Santamaria C., Uesaka T.:“MINOS: A vertex tracker coupled to a thick liquidhydrogen target for in-beam spectroscopy of exotic
nuclei”, Eur. Phys. J. A 50 8 (2014).
Satou Y., Hwang J. W., Kim S., Tshoo K., Choi S.,
Nakamura T., Kondo Y., Matsui N., Hashimoto Y.,
Nakabayashi T., Okumura T., Shinohara M., Fukuda N.,
Sugimoto T., Otsu H., Togano Y., Motobayashi T.,
Sakurai H., Yanagisawa Y., Aoi N., Takeuchi S., Gomi
T., Ishihara M., Kawai S., Ong H. J., Onishi T. K.,
Shimoura S., Tamaki M., Kobayashi T., Matsuda Y.,
Endo N., Kitayama M.: “One-neutron knockout reactionof C-17 on a hydrogen target at 70 MeV/nucleon”,
Phys. Lett. B 728 462-466 (2014).
Patel Z., Browne F., Bruce A.M., Chiga N., Daido R., et al.:"Commissioning of a LaBr3(Ce) array with EURICA at
RIBF" RIKEN Accel. Prog. Rep. 47, 13 (2014)
Yagi A. et al.:"Search for isomers in neutron-rich Cs isotopes"
RIKEN Accel. Prog. Rep. 47 in print (2014)
M. Kurata-Nishimura, H. Otsu and T. Isobe:“Development of Multiple-Particle Tracking Algorithm
for Forward Drift Chamber in SAMURAI"
RIKEN Accel. Prog. Rep. 47 (2014)[Book · Proceedings](Original Papers)*Subject to Peer Review
Wu J., Nishimura S., Lorusso G., Xu Z.Y., Ideguchi E. etal.: "Beta-decay of neutron-rich nuclei with Z~60: The
origin of rare-earth elements" In Proceedings of XIII
Nuclei in the Cosmos, PoS (NIC XIII), page 016. Sissa,(2014).
Jungclaus A., Taprogge J., Simpson G. S., Gey G.,
Nishimura S. et al.: "Beta decay and isomer spectroscopy
in the 132Sn region: New results from EURICA"
J. Phys. Conf. Ser. 533, 012045 (2014)
Shunji Nishimura:"β-decay spectroscopy for the r-process nucleosynthesis"
AIP Conf. Proc. 1595, 144 (2014)
Wu J., Nishimura S., Lorusso G., Xu Z. Y., Baba H., et al.:"β-decay of neutron-rich Z ∼ 60 nuclei and the origin of
Rare Earth Elements" AIP Conf. Proc. 1594, 388 (2014)
Lorusso G., Nishimura S., Baba H., Browne F., Daido R.,
et al.: "β-decay spectroscopy at RIBF: the EURICA
project" AIP Conf. Proc. 1594, 370 (2014)
Jungclaus A., Simpson G.S., Gey G., Taprogge J.,
Nishimura S., et al.:"Isomer and beta decay spectroscopy in the 132Sn region
with EURICA" EPJ Web Conf. 66, 02040 (2014)

Söderström P.-A, Nishimura S., Baba H., Browne F., Daido
R. , et al.: "Status of the EURICA Project After One Year
at RIKEN" JPS Conf. Proc. 1, 013046 (2014)
Xu Z. Y, Nishimura S., Lorusso G., Doornenbal P.,
Sumikama T., et al.: "Systematic Study of β-Decay HalfLives in the Vicinity of 78Ni" JPS Conf. Proc. 1, 013035(2014)
Warr N., Blazhev A. and Moschner K.: "Simulations of
the SIMBA array towards the determination of Qβ
values" EPJ Web Conf. 93, 07008 (2015)
Söderström P.-A., Nishimura S., Doornenbal P., Lorusso G.,
Sumikama T., et al.: “Installation and Commissioning of
EURICA -- Euroball-RIKEN Cluster Array”
Nucl. Inst. Meth. B, 317, 649 (2013)
Wang H. et al., “Structural Evolution of the Pd Isotopes
Towards N = 82”, Proceedings of the 12th Asia PacificPhysics Conference (APPC12), JPS Conf. Proc. Volume
1 (2015)
Wang H. et al., “Collectivity in the neutron-rich Pd isotopes
toward N = 82”, Proceedings of 2nd conference on
Advances in Radioactive Isotope Science (ARIS2014),
JPS Conf. Proc. Volume 6 (2015)
Wang H., “In-beam gamma-ray spectroscopy and crosssection measurement strategy for long-lived fission
products at RIBF”, Proceedings of the 2014 Symposium
on Nuclear Data(*Subject to Peer Review)
M. Kurata-Nishimura, H. Otsu and T. Isobe“Development of Multiple-Particle Tracking Algorithm for
Forward Drift Chamber in SAMURAI"
RIKEN Accel. Prog. Rep. 47 (2014)
Oral Presentations(International Conference etc.)
H. Sakurai : "Emergence of Exotic Phenomena in Unstable
Nuclei -how to observe them", International School of
Nuclear Physics in Eriche, Sicily, Italy, September (2014)
Invited Talk

H. Sakurai : "Physics of Exotic Nuclei at RIBF", APS-JPS
Joint Nuclear Physics Meeting, Hawaii, USA, October(2014) Invited Talk
H. Sakurai : "Physics Programs at RIBF"
International Symposium on Physics of Unstable Nuclei
2014, Ho Chi Minh City, Vietnam, November (2014)
Invited Talk

Nishimura S.: “Survey of decay properties nad perspective
at RIBF”, Workshop on Nuclear Astrophysics, Beihang
Univ., China January 21-23 (2015) Invited Talk
Nishimura S.: “Decay properties of exotic nuclei relevant
to r-process nucleosynthesis”, APS-JPS Meeting 2014,
Hawaii, USA, October 7-11 (2014).
Nishimura S.: “Study of R-process Nucleosynthesis via
Decay Spectroscopy at RIBF”, International nuclear
physics conference (NUBA2014), Adrasan-Antalya,
Turkey, September 15-22 (2014). Invited Talk
Nishimura S.: Decay spectroscopy of exotic nuclei withEURICA spectrometer at RIBF”, Fifteenth International- 478 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Symposium on Capture Gamma-Ray Spectroscopy and
Related Topics (CGS2014), Dresden, Germany, August25-29 (2014). Invited Talk
Nishimura S.: “Decay Properties of Exotic Nuclei with the
EURICA”, 4th European Gamma and Ancillarydetectors network (EGAN2014), Darmstadt, Germany,
June 23-26 (2014). Invited Talk
Nishimura S.: “Decay Properties of Exotic Nuclei and their
Impacts to the r-process Nucleosynthesis” International
Conference for Advances in Radioactive Isotope Science(ARIS2014), Tokyo, Japan, June 1-6 (2014). Invited Talk
Nishimura S.: “Decay spectroscopy of EURICA at RIBF”,
11th International Spring Seminar on Nuclear Physics,
Ischia, Italy, May 12-16 (2014). Invited Talk
Nishimura S.: “Decay spectroscopy of Ni isotopes”, The
structure of 68Ni: Current knowledge and open
questions, Leuven, Belgium, April 23-24 (2014).
Invited Talk

Pieter Doornenbal: "Perspectives for In-Beam Gamma-Ray
Spectroscopy at the RIBF", Invited talk at the JPS
Spring Meeting, Waseda Univ., Japan, March (2015)
Pieter Doornenbal: "Overview of SUNFLOWER", Invited
talk at the Progress in Nuclear Shell-Model Calculations
Workshop, Wako, Japan, November 26-28 (2014)
Pieter Doornenbal: "In-Beam Gamma-Ray Spectroscopy
with Fast Beams Around the `Island of Inversion`'',Invited talk at ISPUN14, Ho Chi Minh City, Vietnam,
November 3th -- 8th (2014)
Pieter Doornenbal: "In-Beam Gamma-Ray Spectroscopy ofFast Exotic Beams at the RIBF", Invited talk at the 4th
Joint APS--JPS Meeting, Hawaii, USA, October 7th -11th (2014)
Pieter Doornenbal: "Overview of In-Beam Gamma-Ray
Spectroscopy at the RIBF", Invited talk at CGS15,
Dresden, Germany, August 25th -- 29th (2014)
Pieter Doornenbal: " Overview of In-Beam Gamma-Ray
Spectroscopy at the RIBF", Invited talk at the Zakopane
Conference on Nuclear Physics, Poland, August 31st -September 7th (2014)
Pieter Doornenbal: "Spectroscopy of Exotic Nuclei withEURICA", Invited talk at Nuclear Structure 2014,
Vancouver, Canada, July 21st -- 25th (2014)
Pieter Doornenbal: "AGATA@RIBF",Oral Presentation at
the 4th EGAN Workshop, Darmstadt, Germany, June
23rd -- 26th (2014)
Par-Anders Soderstrom, “Recent work of decay
spectroscopy at RIBF”, Fourth Joint Meeting of the
Nuclear Physics Divisions of the American PhysicalSociety and The Physical Society of Japan, Waikoloa,
Hawai’i, USA, 8 Oct 2014.
Isobe T., “SPiRIT project for the study of density
dependent symmetry energy of high dense matter with
Heavy RI collisions at RIBF”, 4th International
Symposium on the Nuclear Symmetry Energy
NuSYM14, University of Liverpool, UK, 7-9 July 2014.
Isobe T., “Readout System for SPiRIT experiment”,
SAMURAI International Collaboration Workshop 2014,

Tohoku University, 2014 8th -9th Sep. 2014
Isobe T., “GET for SPiRIT project”, GET collaboration
meeting 2014, Saint Avit Loisirs, France, 22-25 Sep.
2014.
Isobe T., “Development of SPYBOX for the calibration of
GET clock synchronization”, GET collaboration meeting
2014, Saint Avit Loisirs, France, 22-25 Sep. 2014.
Isobe T., “SPiRIT-TPC with GET readout electronics forthe study of density dependent symmetry energy of highdense matter with Heavy RI collisions”, APS/DNP 4th
joint meeting @HAWAII, Hawaii, USA, 7-11 Oct. 2014.
Shiga Y., K. Yoneda, D. Steppenbeck, N. Aoi, P. Doornenbal,
J. Lee, H. Liu, M. Matushita, S. Takeuchi, H. Wang, H.
Baba, P. Bednarczyk, Zs. Dombradi, Zs. Fulop, S. Go, T.
Hashimoto, E. Ideguchi, K. Ieki, K. Kobayashi, Y. Kondo ,et al., “Shell structure studies in the vicinity of the
doubly-magic ^78 Ni by in-beam γ-ray spectroscopy”,
FOURTH JOINT MEETING OF THE NUCLEAR
PHYSICSDIVISIONSOF
THEAMERICANPHYSICAL SOCIETY and The PHYSICAL SOCIETY
OF JAPAN , HAWAII ISLAND, 7th-11th Oct. 2014.
Nakai Y., Hidaka H., Watanabe N., Kojima T. M., “Ionic
cluster formation using an ion drift-tube with selectedion injection - Measurement of thermodynamic
quantities for H3O+ Hydrate”, The 17th International
Symposium on Small Particles and Inorganic Clusters,
Fukuoka, Sep. (2014).
Hidaka H., Nakai Y., Kojima T. M., Watanabe N., “Drift
time measurements of H3O+ hydrate formed by NO+
injection into drift tube filled with H2O/buffer gas at low
temperatures”, The 17th International Symposium on
Small Particles and Inorganic Clusters, Fukuoka, Sep.
(2014).
Nakai Y., Hidaka H., Watanabe N., Kojima T. M.:“Experiments for ionic cluster formation using an ion
drift-tube with selected-ion injection”, Workshop on
interstellar Matter 2014, Sapporo, Oct. (2014).
Hidaka H., Nakai Y., Kojima T. M., Watanabe N.,“Formation of H3O+ hydrate by NO+ injection into drift
tube filled with H2O/buffer gases: separation between
the contributions of two formation pathways by the drift
time measurements”, Workshop on interstellar Matter
2014, Sapporo, Oct. (2014).
(Domestic Conference)
H. Sakurai, "Current Status and Future of RIBF My Very
Personal Perspectives" (招待講演),
RIBF Theory Forum Workshop, Wako, August (2014)
H. Sakurai, "Status of RIBF and Strategy of Operation"(招待講演),
SAMURAI International Collaboration Workshop,
Tohoku University, Sendai, September (2014)
櫻井博儀,"長寿命核分裂廃棄物の核変換データとその戦略"(招待講演)、原子力学会、京都、2014 年 9 月
H. Sakurai, "Nuclear Transmutation Programs at
SAMURAI", SAMURAI International Collaboration
Workshop, Sendai, Japan, Sept., 2014
櫻井博儀,"長寿命核分裂廃棄物の核変換データとその戦略"- 479 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

原子力システム成果報告会、東京、2015 年 1 月
M. Kurata-Nishimura: “Status Of the SPiRIT Time
Projection Chamber”
SAMURAI International Collaboration Workshop 2014 ,Tohoku Univ., Sendai Japan, September (2014)
Par-Anders Soderstrom, “Gamma-ray spectroscopy resultsfrom the EURICA experiment”, Progress in nuclear
shell-model calculations in CNS-RIKEN collaboration,
RIKEN, Wako, Japan, 28th Nov 2014.
磯部忠昭, “理研 RIBF における重 RI 衝突を用いた対称エネ
ルギー密度依存性の研究”, 「宇宙核物理実験の現状と将来」
研究会, 大阪大学核物理研究センター,7th-8th Aug. 2014
磯部忠昭, “理研 RIBF での低エネルギー非対称重イオン衝突を用いた原子核状態方程式の研究”, 「J-PARC における重イオン衝突実験が拓く新しい物理」研究会, KEK,
26th-27th Nov. 2014
磯部忠昭, “ビームタイム一週間の加速器実験に求められる
フレキシブルな計算機環境～RIKEN-RIBF でのコンピューティング ～”, 第 70 回年次大会、シンポジウム「実験のための最先端コンピューティング」, 早稲田大, 21st-24th
Mar. 2015
磯部忠昭, “自由自在にモノ（物質）を変えられるとしたら、何を何に変えたいですか？”, 日本科学未来館 サイエン
ティスト・クエスト, 日本科学未来館, 27 Mar. 2015
http://www.miraikan.jst.go.jp/event/1503031418003.ht
ml
Y. Shiga, K. Yoneda, D. Steppenbeck, N. Aoi, P. Doornenbal,
J. Lee, H. Liu, M. Matushita,S. Takeuchi, H. Wang, H.
Baba, P. Bednarczyk, Zs. Dombradi, Zs. Fulop, S. Go, T.
Hashimoto, E. Ideguchi, K. Ieki, K. Kobayashi, Y. Kondo,
et al., “Persistence of /N/ = 50 shell closure in thevicinity of ^78 Ni studied by in-beam γ -rayspectroscopy”, The 2nd Conference on "Advances inRadioactive
Isotope
Science(ARIS2014)",
Tokyo
University, 1st-6th Jun. 2014,
岸田隆, “核変換技術の科学コミュニケーション”, 第一回「長寿命核分裂核廃棄物の核変換データとその戦略」ワー
クショップ, 和光, 3 月(2014)
岸田隆, “３つの循環と文明論の科学”, 西宮サイエンス談
話会, 西宮, 12 月(2014)
岸田隆, “静かな革命へ向かう覚悟 -- 文明論的視座からのバックキャスティング –“, 自由民主党「国家戦略本部」
講演会, 東京, 3 月(2015)
岸田隆, “３つの循環と文明論の科学”, 鳥居薬品外部講師
講演会, 東京, 3 月(2015)
中井陽一，日高宏，渡部直樹，小島隆夫, “イオン打ち込み
移動管を用いた水和クラスターイオンの生成実験の現状
4”, 日本物理学会第 69 回年次大会, (日本物理学会), 平塚,
3 月(2014)
日高宏，中井陽一，小島隆夫, 渡部直樹,“NO+による水クラスターイオン生成：準安定 NO+による影響”, 日本物理学会第 69 回年次大会, (日本物理学会), 平塚, 3 月(2014)
渡部直樹，日高宏，中井陽一，小島隆夫,“イオン誘起微粒子
核生成 I：装置開発とねらい”，日本地球惑星科学連合大会
2014 年大会，横浜，5 月(2014)
日高宏，中井陽一，小島隆夫, 渡部直樹, “イオン誘起微粒子
核生成 II：水クラスターイオンの自由エネルギー”，日本

地球惑星科学連合大会 2014 年大会，横浜，5 月(2014)
Wang H., “Total kinetic energy detector” (invited talk),
BigRIPS data analysis workshop, RIKEN Nishina
Center, 11th Sep., 2014
Wang H., “Status of RIBF-31 experiment: Structure
study of the neutron-rich nuclei beyond 132Sn” (invitedtalk), 3rd SUNFLOWER workshop, University of Tokyo,
15th -16th Sep., 2014
Wang H., “Cross section measurement strategy for longlived fission product and in-beam gamma-ray
spectroscopy at RIBF” (invited talk), 2014 Symposium
on Nuclear Data, Hokkaido University Conference hall,
Nov. 27-28, 2014
(Other Seminars)
櫻井博儀："科学するこころ -対象、思索、実行-"
不動岡高校、加須市、2014 年 6 月
櫻井博儀："経験、知識、知恵 -実生活から研究活動までの三つのキーワード-", 大宮高校、さいたま市、2014 年 11 月

- 480 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Spin Isospin Laboratory
Publications[Journal]（Original Papers） *Subject to Peer Review
Bai, C. L. and Sagawa, H. and Colo, G. and Fujita, Y. andZhang, H. Q. and Zhang, X. Z. and Xu, F. R.: “Lowenergy collective Gamow-Teller states and isoscalar pairing interaction”, Physical Review C 90, 054335 (2014).*
Bohm, C. and Borgmann, C. and Audi, G. and Beck,
D. and Blaum, K. and Breitenfeldt, M. and Cakirli,
R. B. and Cocolios, T. E. and Eliseev, S. and George,
S. and Herfurth, F. and Herlert, A. and Kowalska, M.
and Kreim, S. and Lunney, D. and Manea, V. andRamirez, E. M. and Naimi, S. and Neidherr, D. andRosenbusch, M. and Schweikhard, L. and Stanja, J. andWang, M. and Wolf, R. N. and Zuber, K.: “Evolution of
nuclear ground-state properties of neutron-deﬁcient isotopes around Z=82 from precision mass measurements”,
Physical Review C 90, 044307 (2014).*
Cao, L. G. and Colo, G. and Sagawa, H. and Bortignon,
P. F.: “Properties of single-particle states in a fully selfconsistent particle-vibration coupling approach”, Physical Review C 89, 044314(2014).*
Colo, G. and Garg, U. and Sagawa, H.: “Symmetry energy from the nuclear collective motion: constraints
from dipole, quadrupole, monopole and spin-dipole resonances”, European Physical Journal A 50, 26(2014).*
Fujita, Y. and Fujita, H. and Adachi, T. and Bai, C. L.
and Algora, A. and Berg, G. P. A. and von Brentano,P. and Colo, G. and Csatlos, M. and Deaven, J. M. andEstevez-Aguado, E. and Fransen, C. and De Frenne, D.
and Fujita, K. and Ganioglu, E. and Guess, C. J. andGulyas, J. and Hatanaka, K. and Hirota, K. and Honma,
M. and Ishikawa, D. and Jacobs, E. and Krasznahorkay,
A. and Matsubara, H. and Matsuyanagi, K. and Meharchand, R. and Molina, F. and Muto, K. and Nakanishi,
K. and Negret, A. and Okamura, H. and Ong, H. J.
and Otsuka, T. and Pietralla, N. and Perdikakis, G. andPopescu, L. and Rubio, B. and Sagawa, H. and Sarriguren, P. and Scholl, C. and Shimbara, Y. and Shimizu,
Y. and Susoy, G. and Suzuki, T. and Tameshige, Y. andTamii, A. and Thies, J. H. and Uchida, M. and Wakasa,
T. and Yosoi, M. and Zegers, R. G. T. and Zell, K. O.
and Zenihiro, J.: “Observation of Low- and High-Energy
Gamow-Teller Phonon Excitations in Nuclei”, PhysicalReview Letters, 112, 112502(2014).*
Hagino, K. and Sagawa, H.: “Three-body model calculation of the 2(+) state in O-26”, Physical Review C, 90,027303(2014).*
Hagino, K. and Sagawa, H.: “Correlated two-neutron
emission in the decay of the unbound nucleus O-26”,
Physical Review C, 89, 014331(2014).*
Hamamoto, I. and Sagawa, H.: “Self-consistent HartreeFock and RPA Green’s function method indicate no- 481 -

pygmy resonance in the monopole response of neutronrich Ni isotopes”, Physical Review C, 90, 031302(2014).*Isaka, M. and Fukukawa, K. and Kimura, M. and Hiyama,
E. and Sagawa, H. and Yamamoto, Y.: “Superdeformed
Lambda hypernuclei with antisymmetrized molecular
dynamics”, Physical Review C, 89, 024310(2014).*
Karakoc, M. and Zegers, R. G. T. and Brown, B. A. andFujita, Y. and Adachi, T. and Boztosun, I. and Fujita,
H. and Csatlos, M. and Deaven, J. M. and Guess, C.
J. and Gulyas, J. and Hatanaka, K. and Hirota, K.
and Ishikawa, D. and Krasznahorkay, A. and Matsubara, H. and Meharchand, R. and Molina, F. and Okamura, H. and Ong, H. J. and Perdikakis, G. and Scholl,
C. and Shimbara, Y. and Susoy, G. and Suzuki, T. andTamii, A. and Thies, J. H. and Zenihiro, J.: “GamowTeller transitions in the A=40 isoquintet of relevancefor neutrino captures in Ar-40”, Physical Review C, 89,064313(2014).*
Kreim, S. and Beck, D. and Blaum, K. and Borgmann, C.
and Breitenfeldt, M. and Cocolios, T. E. and Gottberg,
A. and Herfurth, F. and Kowalska, M. and Litvinov, Y.
A. and Lunney, D. and Manea, V. and Mendonca, T.
M. and Naimi, S. and Neidherr, D. and Rosenbusch, M.
and Schweikhard, L. and Stora, T. and Wienholtz, F.
and Wolf, R. N. and Zuber, K.: “Competition between
pairing correlations and deformation from the odd-evenmass staggering of francium and radium isotopes”, Physical Review C, 90, 024301(2014).*
Ladygin, V. P. and Uesaka, T. and Glagolev, V. V. andGurchin, Y. V. and Isupov, A. Y. and Itoh, K. andJanek, M. and Karachuk, J. T. and Kawabata, T. andKhrenov, A. N. and Kiselev, A. S. and Krasnov, V. A.
and Kurepin, A. B. and Kurilkin, A. K. and Kurilkin,
P. K. and Ladygina, N. B. and Lipchinski, D. and
Maeda, Y. and Malakhov, A. I. and Martinska, G. and
Nedev, S. and Piyadin, S. M. and Popovichi, J. andRangelov, S. and Reznikov, S. G. and Rukoyatkin, P.
A. and Sakaguchi, S. and Sakai, H. and Sekiguchi, K.
and Shikhalev, M. A. and Suda, K. and Terekhin, A. A.
and Trpisova, B. and Urban, J. and Vasiliev, T. A. andVnukov, I. E. and Witala, H.: “Spin physics in few bodysystems at Nuclotron”, Physics of Particles and Nuclei,
45, 327-329(2014).*
Lu, B. N. and Hiyama, E. and Sagawa, H. and Zhou,
S. G.: “Superdeformed Lambda hypernuclei within relativistic mean ﬁeld models”, Physical Review C, 89,044307(2014).*Maeda, Y. and Saito, T. and Miyasako, H. and Uesaka, T.
and Ota, S. and Kawase, S. and Kikuchi, T. and Tokieda, H. and Kawabata, T. and Yako, K. and Wakasa, T.
and Sakaguchi, S. and Chen, R. and Sakaguchi, H. andShima, T. and Suzuki, T. and Tamii, A.: “Measurementof the H-2(p, n) Breakup Reaction at 170 MeV and theThree-Nucleon Force Eﬀects”, Few-Body Systems, 55,
729-732(2014).*

1

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Myo, T. and Kikuchi, Y. and Mosui, H. and Kato, K.: “Recent development of complex scaling method for manybody resonances and continua in light nuclei”, Progress
in Particle and Nuclear Physics, 79, 1-56(2014).*
Obertelli, A. and Delbart, A. and Anvar, S. and Audirac,
L. and Authelet, G. and Baba, H. and Bruyneel, B. andCalvet, D. and Chateau, F. and Corsi, A. and Doornenbal, P. and Gheller, J. M. and Giganon, A. and LahondeHamdoun, C. and Leboeuf, D. and Loiseau, D. and Mohamed, A. and Mols, J. P. and Otsu, H. and Peron,C. and Peyaud, A. and Pollacco, E. C. and Prono, G.
and Rousse, J. Y. and Santamaria, C. and Uesaka, T.:“MINOS: A vertex tracker coupled to a thick liquidhydrogen target for in-beam spectroscopy of exotic nuclei”, European Physical Journal A, 50, 8(2014).*
Oishi, T. and Hagino, K. and Sagawa, H.: “Role of diproton correlation in two-proton-emission decay of the Be-6
nucleus”, Physical Review C, 90, 034303(2014).*
Sagawa, H. and Colo, G.: “Tensor interaction in meanﬁeld and density functional theory approaches to nuclear
structure”, Progress in Particle and Nuclear Physics, 76,
76-115(2014).*
Schury, P. and Wada, M. and Ito, Y. and Arai, F.
and Naimi, S. and Sonoda, T. and Wollnik, H.
and Shchepunov, V. A. and Smorra, C. and Yuan,
C.: “A high-resolution multi-reﬂection time-of-ﬂight
mass spectrograph for precision mass measurements at
RIKEN/SLOWRI”, Nuclear Instruments and Methods
in Physics Research Section B-Beam Interactions with
Materials and Atoms, 335, 39-53(2014).*
Scott, M. and Shimbara, Y. and Austin, S. M. and Bazin,
D. and Brown, B. A. and Deaven, J. M. and Fujita,
Y. and Guess, C. J. and Gupta, S. and Hitt, G. W.
and Koeppe, D. and Meharchand, R. and Nagashima,
M. and Perdikakis, G. and Prinke, A. and Sasano, M.
and Sullivan, C. and Valdez, L. and Zegers, R. G.
T.: “Gamow-Teller transition strengths from Fe-56 extracted from the Fe-56(t,He-3) reaction”, Physical Review C, 90, 025801(2014).*
Sekiguchi, K. and Okamura, H. and Wada, Y. andMiyazaki, J. and Taguchi, T. and Gebauer, U. and Dozono, M. and Kawase, S. and Kubota, Y. and Lee, C. S.
and Maeda, Y. and Mashiko, T. and Miki, K. and Sakaguchi, S. and Sakai, H. and Sakamoto, N. and Sasano,
M. and Shimizu, Y. and Takahashi, K. and Tang, R.
and Uesaka, T. and Wakasa, T. and Yako, K.: “Complete Set of Deuteron Analyzing Powers for dp Elastic
Scattering at Intermediate Energies and Three Nucleon
Forces” Few-Body Systems, 55, 717-719(2014).*
Sekiguchi, K. and Okamura, H. and Wada, Y. andMiyazaki, J. and Taguchi, T. and Gebauer, U. and Dozono, M. and Kawase, S. and Kubota, Y. and Lee, C. S.
and Maeda, Y. and Mashiko, T. and Miki, K. and Sakaguchi, S. and Sakai, H. and Sakamoto, N. and Sasano,
M. and Shimizu, Y. and Takahashi, K. and Tang, R. and- 482 -

Uesaka, T. and Wakasa, T. and Yako, K.: “Complete setof deuteron analyzing powers for dp elastic scattering at
intermediate energies”, Physics of Particles and Nuclei,
45, 190-192(2014).*
Sekiguchi, K. and Wada, Y. and Miyazaki, J. and Witala,H. and Dozono, M. and Gebauer, U. and Golak, J. and
Kamada, H. and Kawase, S. and Kubota, Y. and Lee,
C. S. and Maeda, Y. and Mashiko, T. and Miki, K. andNogga, A. and Okamura, H. and Saito, T. and Sakai,
H. and Sakaguchi, S. and Sakamoto, N. and Sasano, M.
and Shimizu, Y. and Skibinski, R. and Suzuki, H. andTaguchi, T. and Takahashi, K. and Tang, T. L. and Uesaka, T. and Wakasa, T. and Yako, K.: “Complete setof deuteron analyzing powers for dp elastic scattering
at 250-294 MeV/nucleon and the three-nucleon force”,
Physical Review C, 89, 064007(2014).*
Stuhl, L. and Krasznahorkay, A. and Csatlos, M. and Algora, A. and Gulyas, J. and Kalinka, G. and Timar,
J. and Kalantar-Nayestanaki, N. and Rigollet, C. and
Bagchi, S. and Najaﬁ, M. A.: “A neutron spectrometerfor studying giant resonances with (p,n) reactions in inverse kinematics”, Nuclear Instruments and Methods inPhysics Research Section a-Accelerators Spectrometers
Detectors and Associated Equipment, 736, 1-9(2014).*
Tanimura, Y. and Sagawa, H. and Hagino, K.: “Threebody model calculations for N = Z odd-odd nuclei with
T=0 and T=1 pairing correlations” Progress of Theoretical and Experimental Physics, 5, 053D02(2014).*
Wen, P. W. and Cao, L. G. and Margueron, J. and Sagawa,H.: “Spin-isospin response in ﬁnite nuclei from an extended Skyrme interaction”, Physical Review C, 89,044311(2014).*2

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Nuclear Spectroscopy Laboratory
Publications[Journal]（Original Papers） *Subject to Peer Review
Asahi K., Ichikawa Y., Chikamori M., Ohtomo Y., Hikota
E., Suzuki T., Inoue T., Furukawa T., Yoshimi A.,
Suzuki K., Nanao T., Miyatake H., Tsuchiya M.,
Yoshida N., Shirai H., Ino T., Ueno H., Matsuo Y.,
and Fukuyama T.: “Search for Electric Dipole Momentin 129 Xe Atom Using a Nuclear Spin Oscillator” Phys.
Part. Nucl. 45, 199–201 (2014). ＊Yang X. F., Furukawa T., Wakui T., Fujita T., Imamura
K., Mitsuya Y., Hayasaka M., Ichikawa Y., Ishibashi
Y., Shirai H., Suzuki T., Ebara Y., Hatakeyama A.,
Wada M., Sonoda T., Ito Y., Kobayashi T., Nishimura
S., Nishimura M., Kondo Y., Yoneda K., Kubono S.,
Ohshiro Y., Ueno H., Shinozuka T., Shimoda T., Asahi
K., and Matsuo Y.: “Laser-radio-frequency double resonance spectroscopy of 84−87 Rb isotopes trapped in superflid helium”, Phys. Rev. A 90, 052516 (2014). ＊Michimasa S., Yanagisawa Y., Inafuku K., Aoi N., Elekes
Z., Fulop Zs., Ichikawa Y., Iwasa N., Kurita K.,
Kurokawa M., Machida T., Motobayashi T., Nakamura
T., Nakabayashi T., Notani M., Ong H. J., Onishi
T. K., Otsu H., Sakurai H., Shinohara M., SumikamaT., Takeuchi S., Tanaka K., Togano Y., Yamada K.,
Yamaguchi M., and Yoneda K.: “Quadrupole collectivity in island-of-inversion nuclei 28,30 Ne and 34,36 Mg”,
Phys. Rev. C 89, 054307 (2014). ＊（Review）
上野秀樹 : “理研 RI ビームファクトリー施設と利用研究”,
応用物理学会放射線分科会会誌 放射線 40, 85–91 (2014).
市川雄一 : “スピン操作した RI ビームの生成”, 原子核研究
59, 29–39 (2014).
[Book・Proceedings]（Original Papers） *Subject to Peer Review
Kubo M. K., Kobayashi Y., Yamada Y., Mihara
M., Nagatomo T., Sato W., Miyazaki J., Sato S.,
and Kitagawa A.: “In-beam Mössbauer spectroscopy of57
Fe/57 Mn in MgO and NaF at Heavy-Ion Medical Accelerator in Chiba” Rev. Sci. Instrum. 85 02C310(2014).
Ichikawa Y., Sato T., Ohtomo Y., Sakamoto Y., KojimaS., Suzuki T., Chikamori M., Hikota E., Miyatake H.,
Nanao T., Suzuki K., Tsuchiya M., Inoue T., Furukawa
T., Yoshimi A., Bidinosti C. P., Ino T., Ueno H., Matsuo
Y., Fukuyama T., and Asahi K.: “Search for EDM in
129
Xe using active spin maser”, Proceedings of 7th International Workshop on Fundamental Physics Using
Atoms (FPUA2014), Tokyo, 2014–3, pp. 37–44 (2015).
Sato T., Ichikawa Y., Ohtomo Y., Sakamoto Y., KojimaS., Suzuki T., Chikamori M., Hikota E., Miyatake H.,
Nanao T., Suzuki K., Tsuchiya M., Inoue T., Furukawa
T., Yoshimi A., Bidinosti C. P., Ino T., Ueno H., Matsuo

Y., Fukuyama T., and Asahi K.: “Co-magnetometry
with 129 Xe/3 He dual active spin maser technique”, Proceedings of 7th International Workshop on Fundamental
Physics Using Atoms (FPUA2014), Tokyo, 2014–3, pp.
80–83 (2015).
Sakamoto Y., Bidinosti C. P., Ichikawa Y., Sato T.,
Ohtomo Y., Kojima S., Suzuki T., Chikamori M., Hikota
E., Miyatake H., Nanao T., Suzuki K., Tsuchiya M.,
Inoue T., Furukawa T., Yoshimi A., Ino T., Ueno
H., Matsuo Y., Fukuyama T., and Asahi K.: “Performance test of improved magnetic-field system for
129
Xe EDM measurement”, Proceedings of 7th International Workshop on Fundamental Physics Using Atoms(FPUA2014), Tokyo, 2014–3, pp. 84–87 (2015).
Ohtomo Y., Ichikawa Y., Sato T., Sakamoto Y., KojimaS., Suzuki T., Chikamori M., Hikota E., Miyatake H.,
Nanao T., Suzuki K., Tsuchiya M., Inoue T., Furukawa
T., Yoshimi A., Bidinosti C. P., Ino T., Ueno H., Matsuo
Y., Fukuyama T., and Asahi K.: “Study of EDM cellwith coexisting 129 Xe/3 He”, Proceedings of 7th International Workshop on Fundamental Physics Using Atoms(FPUA2014), Tokyo, 2014–3, pp. 88–91 (2015).
Kojima S., Sato T., Ichikawa Y., Ohtomo Y., SakamotoY., Suzuki T., Chikamori M., Hikota E., Miyatake H.,
Nanao T., Suzuki K., Tsuchiya M., Inoue T., Furukawa
T., Yoshimi A., Bidinosti C. P., Ino T., Ueno H., Matsuo
Y., Fukuyama T., and Asahi K.: “Digital feedback system for active spin maser”, Proceedings of 7th International Workshop on Fundamental Physics Using Atoms(FPUA2014), Tokyo, 2014–3, pp. 92–95 (2015).
Oral Presentations(International Conference etc.)
Ueno H.: “Polarized beams?”, 3rd EURICA Workshop, (RIKEN Nishina Center ), Wako, Japan, Apr. (2014).
Ueno H.: “Ground state structure study around the island of inversion”, RIBF Discussion Plus! –Island of inversion, ( RIKEN Nishina Center ), Wako, Japan, Apr.
(2014).
Ueno H.: “Nuclear Moments and Structure of Unstable
Nuclei”, The 2nd Conference on advances in Radioactive Isotope Science (ARIS2014), ( RIKEN Nishina Center and the Center for Nuclear Study, the University ofTokyo), Tokyo, Japan, Jun. (2014).
Yang X. F., Furukawa T., Wakui T., Fujita T., Imamura
K., Mitsuya Y., Hayasaka M., Ichikawa Y., Ishibashi
Y., Shirai H., Suzuki T., Ebara Y., Hatakeyama A.,
Wada M., Sonoda T., Ito Y., Kobayashi T., Nishimura
S., Nishimura M., Kondo Y., Yoneda K., Kubono S.,
Ohshiro Y., Ueno H., Shinozuka T., Shimoda T., Asahi
K., and Matsuo Y.: “A laser spectroscopy method using superfluid helium for measurements of spins andelectromagnetic moments in exotuc nuclei”, The 2nd
Conference on advances in Radioactive Isotope Science(ARIS2014), ( RIKEN Nishina Center and the Center for- 483 -

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Ⅶ. LIST OF PUBLICATIONS

Nuclear Study, the University of Tokyo), Tokyo, Japan,
Jun. (2014).
Sato T., Ichikawa Y., Ohtomo Y., Sakamoto Y., KojimaS., Suzuki T., Shirai H., Chikamori M., Hikota E.,
Miyatake H., Nanao T., Suzuki K., Tsuchiya M., Inoue
T., Furukawa T., Yoshimi A., Bidinosti C. P., Ino
T., Ueno H., Matsuo Y., Fukuyama T., and Asahi K.:“129 Xe EDM Search Experiment Using Active Nuclear
Spin Maser”, The 2nd Conference on advances in Radioactive Isotope Science (ARIS2014), ( RIKEN Nishina
Center and the Center for Nuclear Study, the Universityof Tokyo), Tokyo, Japan, Jun. (2014).
Imamura K., Furukawa T., Yang X. F., Mitsuya Y., Fujita
T., Hayasaka M., Kobayashi T., Hatakeyama A., Ueno
H., and Asahi K.: “Measurement of the hyperﬁne splitting of 133 Cs atoms in superﬂuid helium”, The 5th
Joint International Conference on Hyperﬁne Interactions
and Symposium on Nuclear Quadrupole Interactions(HFI/NQI 2014), (University of New South Wales andAustralian National University), Canberra, Australia,
Sep. (2014).
Sato T., Ichikawa Y., Ohtomo Y., Sakamoto Y., Kojima
S., Funayama C., Suzuki T., Chikamori M., Hikota E.,
Tsuchiya M., Furukawa T., Yoshimi A., Bidinosti C. P.,
Ino T., Ueno H., Matsuo Y., Fukuyama T., and Asahi
K.: “EDM measmrement in 129 Xe atom using dual active feedback nuclear spin maser”, The 5th Joint International Conference on Hyperﬁne Interactions and Symposium on Nuclear Quadrupole Interactions (HFI/NQI2014), (University of New South Wales and Australian
National University), Canberra, Australia, Sep. (2014).
Sakamoto Y., Bidinosti C. P., Ichikawa Y., Sato T.,
Ohtomo Y., Kojima S., Funayama C., Suzuki T.,
Tsuchiya M., Furukawa T., Yoshimi A., Ueno H.,
Matsuo Y., Fukuyama T., and Asahi K.: “Developmentof high-homogeneity magnetic ﬁeld coil for 129 Xe EDM
experiment”, The 5th Joint International Conference
on Hyperﬁne Interactions and Symposium on Nuclear
Quadrupole Interactions (HFI/NQI 2014), (Universityof New South Wales and Australian National University), Canberra, Australia, Sep. (2014).
Ueno H.: “Scientiﬁc opportunities and plans for RIBF”,
4th Joint Meeting of the Nuclear Physics Division of theAmerican Physical Society and The Physical Society ofJapan (HAWAII 2014), (the American Physical Society
and The Physical Society of Japan), Waikoloa, Hawaii,
USA, Oct. (2014).
Furukawa T., “OROCHI experiment: Laser spectroscopyof RI atoms in superﬂuid helium for measurements ofnuclear spins and electromagnetic moments”, 4th Joint
Meeting of the Nuclear Physics Division of the American Physical Society and The Physical Society of Japan(HAWAII 2014), (the American Physical Society and
The Physical Society of Japan), Waikoloa, Hawaii, USA,
Oct. (2014).

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Ichikawa Y., Sato T., Ohtomo Y., Sakamoto Y., Kojima
S., Funayama C., Hirao C., Suzuki T., Chikamori M.,
Hikota E., Miyatake H., Nanao T., Suzuki K., TsuchiyaM., Inoue T., Furukawa T., Yoshimi A., Bidinosti C. P.,
Ino T., Ueno H., Matsuo Y., Fukuyama T., and Asahi
K.: “Experimental search for EDM in diamagnetic atom
129
Xe using active nuclear spin maser” 4th Joint Meetingof the Nuclear Physics Division of the American PhysicalSociety and The Physical Society of Japan (HAWAII2014), (the American Physical Society and The PhysicalSociety of Japan), Waikoloa, Hawaii, USA, Oct. (2014).
Sato T., Ichikawa Y., Ohtomo Y., Sakamoto Y., Kojima
S., Funayama C., Suzuki T., Chikamori M., Hikota E.,
Tsuchiya M., Furukawa T., Yoshimi A., Bidinosti C. P.,
Ino T., Ueno H., Matsuo Y., Fukuyama T., and Asahi
K.: “Progress of the 129 Xe EDM search using active
feedback nuclear spin maser”, 4th Joint Meeting of the
Nuclear Physics Division of the American Physical Society and The Physical Society of Japan (HAWAII 2014),(the American Physical Society and The Physical Society of Japan), Waikoloa, Hawaii, USA, Oct. (2014).
Kojima S., Sato T., Ichikawa Y., Ohtomo Y., SakamotoY., Funayama C., Suzuki T., Chikamori M., Hikota E.,
Tsuchiya M., Furukawa T., Yoshimi A., Bidinosti C. P.,
Ino T., Ueno H., Matsuo Y., Fukuyama T., and Asahi
K.: “Performance of active nuclear spin maser withdouble-cell geometry”, 4th Joint Meeting of the Nuclear Physics Division of the American Physical Society
and The Physical Society of Japan (HAWAII 2014), (theAmerican Physical Society and The Physical Society ofJapan), Waikoloa, Hawaii, USA, Oct. (2014).
Sakamoto Y., Bidinosti C. P., Ichikawa Y., Sato T.,
Ohtomo Y., Kojima S., Funayama C., Suzuki T.,
Tsuchiya M., Furukawa T., Yoshimi A., Ino T., Ueno
H., Matsuo Y., Fukuyama T., and Asahi K.: “Performance check of cell with newly designed electrode for129
Xe EDM measurement”, 4th Joint Meeting of the Nuclear Physics Division of the American Physical Society
and The Physical Society of Japan (HAWAII 2014), (theAmerican Physical Society and The Physical Society ofJapan), Waikoloa, Hawaii, USA, Oct. (2014).
Funayama C., Furukawa T., Sato T., Ichikawa Y., Ohtomo
Y., Sakamoto Y., Kojima S., Suzuki T., Chikamori M.,
Hikota E., Tsuchiya M., Yoshimi A., Bidinosti C. P.,
Ino T., Ueno H., Matsuo Y., Fukuyama T., and Asahi
K.: “Development of a high intensity laser for eﬀecient
spin exchange optical pumping in a spin maser measurement of the 129 Xe EDM”, 4th Joint Meeting of the Nuclear Physics Division of the American Physical Society
and The Physical Society of Japan (HAWAII 2014), (theAmerican Physical Society and The Physical Society ofJapan), Waikoloa, Hawaii, USA, Oct. (2014).
Ohtomo Y., Ichikawa Y., Shirai H., Ueno H., Ishibashi
Y., Suzuki T., Furukawa T., Yoshimi A., Abe Y., Asahi
K., Daugas J. M., Fujita T., Hayasaka M., Imamura K.,

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Kishi S., Kojima S., Nagae D., Nakao A., Sagayama T.,
Sakamoto Y., Sato Y.: “Ground-state nuclear-momentmeasurement of neutron-rich sulfur isotopes”, 4th Joint
Meeting of the Nuclear Physics Division of the American Physical Society and The Physical Society of Japan(HAWAII 2014), (the American Physical Society and
The Physical Society of Japan), Waikoloa, Hawaii, USA,
Oct. (2014).
Imamura K., Furukawa T., Yang X. F., Fujita T., Wakui
T., Mitsuya Y., Hayasaka M., Ichikawa Y., HatakeyamaA., Kobayashi T., Odashima H., Ueno H., and Matsuo
Y.: “Hyperﬁne structure measurement of 87 Rb atoms
injected into superﬂuid helium as highly energetic ionbeam”, 4th Joint Meeting of the Nuclear Physics Division of the American Physical Society and The Physical Society of Japan (HAWAII 2014), (the American
Physical Society and The Physical Society of Japan),
Waikoloa, Hawaii, USA, Oct. (2014).
Hayasaka M., Furukawa T., Tomita H., Takamatsu T.,
Imamura K., Fujita T., Kobayashi T., Uematsu H., Ueno
H., and Matsuo Y.: “Eﬀective production of spin polarization of atoms in superﬂuid helium using pulsed
lasers”, 4th Joint Meeting of the Nuclear Physics Division of the American Physical Society and The Physical Society of Japan (HAWAII 2014), (the American
Physical Society and The Physical Society of Japan),
Waikoloa, Hawaii, USA, Oct. (2014).
Fujita T., Furukawa T., Imamura K., Yang X. F., Mitsuya
Y., Hayasaka M., Sagayama T., Kishi S., Kobayashi T.,
Ueno H., Shimoda T., and Matsuo Y.: “Sublevel laser
spectroscopy of 197 Au atom in superﬂuid helium”, 4thJoint Meeting of the Nuclear Physics Division of theAmerican Physical Society and The Physical Society ofJapan (HAWAII 2014), (the American Physical Society
and The Physical Society of Japan), Waikoloa, Hawaii,
USA, Oct. (2014).
Kinbara S., Nakazawa K., Ichikawa Y., Ueno H., YoshidaJ., Khin T. T., Myint K. S., Mishina A., Ito H., EndoY., and Kobayashi H.: “Isotope Identiﬁcation in Nuclear Emulsion Plate”, 4th Joint Meeting of the Nuclear Physics Division of the American Physical Society
and The Physical Society of Japan (HAWAII 2014), (theAmerican Physical Society and The Physical Society ofJapan), Waikoloa, Hawaii, USA, Oct. (2014).
Ueno H.: “Production of High Nuclear Spin Alignment ofRadioactive Ion Beams”, The 21st International Symposium on Spin Physics (SPIN2014), (Peking University),
Beijing, China, Oct. (2014).
Furukawa T., Yang X. F., Imamura K., Fujita T., Wakui
T., Mitsuya Y., Hayasaka M., Ichikawa Y., Ishibashi Y.,
Shirai H., Suzuki T., Sato T., Ohtomo Y., Kojima S.,
Ebara Y., Kishi S., Sagayama T., Wada M., Sonoda
T., Ito Y., Kobayashi T., Nishimura S., Nishimura
M., Kondo Y., Yoneda K., Kubono S., Ohshiro Y.,
Hatakeyama A., Ueno H., Shinozuka T., Shimoda T.,

Asahi K., and Matsuo Y.: “Spin polarization of radioisotope atoms with optical pumping in superﬂuid helium
for the measurement of nuclear spins and electromagnetic moments”, The 21st International Symposium on
Spin Physics (SPIN2014), (Peking University), Beijing,
China, Oct. (2014).
Ueno H.: “Research Activities at RIBF”, Internaional
Workshop on Progress in nuclear shell-model calculations in CNS-RIKEN collaboration, (Center for Nuclear
Study, the University of Tokyo and RIKEN Nishina Center), Wako, Japan, nov. (2014).
Yamazaki H., and Shannon N.: “Superconducting Proximity Eﬀects in Nb/rare-earth Bilayers”, The 9th International Symposium on Intrinsic Josephson Eﬀects and
THz Plasma Oscillations in High-Tc Superconductors(THz-Plasma 2014), Kyoto, Japan, Nov.–Dec. (2014).
Fujita T., Furukawa T., Imamura K., Yang X. F., Wakui
T., Mitsuya Y., Hayasaka M., Ichikawa Y., Ishibashi
Y., Shirai H., Suzuki T., Sato T., Ohtomo Y., Kojima
S., Ebara Y., Kishi S., Sagayama T., HatakeyamaA., Kobayashi T., Ueno H., Asahi K., Shimoda T.,
and Matsuo Y.: “Leaser spectroscopy of atoms in superﬂuid helium for the measurement of nuclear spins andelectromagnetic moments of radioisotope atoms”, 6thInternational Conference on Trapped Charged Particles
and Fundamental Physics (TCP2014), (RIKEN Nishina
Center), Takamatsu, Japan, Dec. (2014).
(Domestic Conference)
上野秀樹 : “理研 RI ビームファクトリーと最近の研究成果”,
明治大学 科学技術研究所講師招聘講演会物理学系セミナー, (明治大学), 神奈川県川崎市, 7 月 (2014).
今村慧 , 古川武 , YangXiaofei , 三津谷洋助 , 藤田朋美 , 早坂
美希 , 小林徹 , 畠山温 , 上野秀樹 , 松尾由賀利 : “超流動ヘリウム中に植えこまれた Cs 原始の超微細構造間隔”, 日
本物理学会 2014 年秋季大会, (日本物理学会), 愛知県春日井市, 9 月 (2014).
市川雄一 : “RI を用いた原子 EDM 探索に向けて”, RCNP 研究
会 “CP violation in elementary particles and composite
systems”, (大阪大学核物理研究センター), 大阪府吹田市,
11 月 (2014).
佐藤 智哉 : “能 動 帰 還 型 ス ピ ン メ ー ザ ー に よ る 129 Xe
原 子 EDM 探 索 実 験”, RCNP 研 究 会 “CP violation inelementary particles and composite systems”, (大阪大学
核物理研究センター), 大阪府吹田市, 11 月 (2014).
旭耕一郎 : “EDM の実験的探索の現状”, 日本物理学会第 70回年次大会, (日本物理学会), 東京都新宿区, 3 月 (2015).
舟山智歌子 , 古川武 , 佐藤智哉 , 市川雄一 , 大友祐一 , 坂本雄, 小島修一郎 , 平尾千佳 , 菅野雄揮 , 小峰太郎 , 鈴木貴大 ,近森正敏 , 彦田絵里 , 土屋真人 , 吉見彰洋 , Bidinosti C.
P., 猪野隆 , 上野秀樹 , 松尾由賀利 , 福山武志 , 旭耕一郎
: “129 Xe/3 He 同時メーザー発振のためのポンピングレー
ザーシステムの開発”, 日本物理学会第 70 回年次大会, (日本物理学会), 東京都新宿区, 3 月 (2015).
坂本雄 , Bidinosti C. P., 市川雄一 , 佐藤智哉 , 大友祐一 ,小島修一郎 , 舟山智歌子 , 平尾千佳 , 菅野雄揮 , 小峰太郎

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS, 鈴木 貴大 , 近森 正敏 , 彦田 絵里 , 土屋 真人 , 古川 武 ,吉見彰洋 , 猪野隆 , 上野秀樹 , 松尾由賀利 , 福山武志 , 旭
耕一郎 : “一様磁場環境下での 129 Xe/3 He 同時メーザー発振”, 日本物理学会第 70 回年次大会, (日本物理学会), 東京
都新宿区, 3 月 (2015).
小島修一郎 , 佐藤智哉 , 市川雄一 , 大友祐一 , 坂本雄 , 舟山
智歌子 , 平尾千佳 , 菅野雄揮 , 小峰太郎 , 鈴木貴大 , 近森
正敏 , 彦田絵里 , 土屋真人 , 古川武 , 吉見彰洋 , Bidinosti
C. P., 猪野 隆 , 上野 秀樹 , 松尾 由賀利 , 福山 武志 , 旭
耕一郎 : “ダブルセルにおける 129 Xe/3 He 核スピンメー
ザーの周波数特性”, 日本物理学会第 70 回年次大会, (日本物理学会), 東京都新宿区, 3 月 (2015).
佐藤智哉 , 市川雄一 , 大友祐一 , 坂本雄 , 小島修一郎 , 舟山
智歌子 , 平尾千佳 , 菅野雄揮 , 小峰太郎 , 鈴木貴大 , 近森
正敏 , 彦田絵里 , 土屋真人 , 古川武 , 吉見彰洋 , Bidinosti
C. P., 猪野 隆 , 上野 秀樹 , 松尾 由賀利 , 福山 武志 , 旭
耕一郎 : “3 He 共存磁力計の導入による 129 Xe 原子 EDM
測定実験 IV”, 日本物理学会第 70 回年次大会, (日本物理学会), 東京都新宿区, 3 月 (2015).
西村太樹 , 金野峻平 , 田口義眞 , 千葉順成 , 藤田佳孝 , 阿部康介 , 馬場秀忠 , 福田茂一 , 本間彰 , 保高寿也 , 市川雄一
, 泉川卓司 , 神戸峻輔 , 菊川直樹 , 北川淳志 , 小島拓実 ,小島和佳 , 古浦新司 , 劉斌 , 松多健策 , 三原基嗣 , 水上淳 , 森田祐介 , 室岡大樹 , 長島正幸 , 大野淳一 , 大坪隆 ,鈴木伸司 , 佐藤眞司 , 田中聖臣 , 田代圭佑 , 若林優 , 渡邉
大 , 吉永健太 , 朱易帆 : “超許容ベータ崩壊核 34 Ar の精
密分岐比測定 III”, 日本物理学会第 70 回年次大会, (日本物理学会), 東京都新宿区, 3 月 (2015).
大友祐一 , 市川雄一 , 石橋陽子 , 鈴木貴大 , 上野秀樹 , 今村
慧 , 藤田朋美 , 早坂美希 , 富永大樹 , 松本未来 , 江上魁, 古川武 , 佐藤智哉 , 坂本雄 , 小島修一郎 , 舟山智歌子 ,平尾千佳 , 菅野雄揮 , 小峰太郎 , 旭耕一郎 : “中性子過剰
核 S 同位体の偏極度および磁気モーメント測定”, 日本物理学会第 70 回年次大会, (日本物理学会), 東京都新宿区, 3 月(2015).
今村慧 , 古川武 , 涌井崇志 , 藤田朋美 , 早坂美希 , 松本未来
, 江上魁 , 富永大樹 , 小田島仁司 , 上野秀樹 , 松尾由賀利: “低収量原子核の核構造研究へ向けたレーザー・RF/MW
二重共鳴信号の高強度化”, 日本物理学会第 70 回年次大会,(日本物理学会), 東京都新宿区, 3 月 (2015).
金原 慎二 , 仲澤 和馬 , 上野 秀樹 , 市川 雄一 , 吉田 純也 ,KhinThanTint , MyintKyawSoe , AyeMohMohTheint ,三品旭弘 , 伊藤宏紀 , 遠藤陽子 , 小林秀隆 : “原子核乾板を用いた荷電粒子識別法の開発”, 日本物理学会第 70 回年次大会, (日本物理学会), 東京都新宿区, 3 月 (2015).

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

High Energy Astrophysics Laboratory
Publications[Journal]（Original Papers） *Subject to Peer Review
Noda, Hirofumi; Makishima, Kazuo; Yamada, Shin’ya;
Nakazawa, Kazuhiro; Sakurai, Soki; Miyake, Katsuma:“Suzaku Studies of the Central Engine in the TypicalType I Seyfert NGC 3227: Detection of Multiple Primary X-Ray Continua with Distinct Properties” The
Astrophysical Journal, 794, 2 (2014). *Yoshikawa, A., Yamada, S., Nakahira, S., Matsuoka, M.,
Negoro, H., Mihara, T., Tamagawa, T.: “Repeatedshort-term spectral softening in the low/hard state of
the Galactic black hole candidate Swift J1753.5-0127”
Publications of the Astronomical Society of Japan, 67,
11 (2015). *Asami, Fumi; Enoto, Teruaki; Iwakiri, Wataru; Yamada,Shin’ya; Tamagawa, Toru; Mihara, Tatehiro; Nagase,
Fumiaki: “Broad-band spectroscopy of Hercules X-1
with Suzaku” Publications of the Astronomical Societyof Japan, 66, 44 (2014). *Hamaguchi, Kenji; Corcoran, Michael F.; Takahashi,
Hiromitsu; Yuasa, Takayuki; Ishida, Manabu; Gull,
Theodore R.; Pittard, Julian M.; Russell, Christopher
M. P.; Madura, Thomas I.: “Suzaku Monitoring ofHard X-Ray Emission from η Carinae over a Single Binary Orbital Cycle” The Astrophysical Journal, 795, 119(2014). *Suwa, Y., Enoto, T.: “Anisotropic neutrino eﬀect on magnetar spin: constraint on inner toroidal ﬁeld” Monthly
Notices of the Royal Astronomical Society 443, 3586
(2014). *Makishima, K., Enoto, T., Hiraga, J. S., Nakano, T.,
Nakazawa, K., Sakurai, S., Sasano, M., Murakami, H.:“Possible Evidence for Free Precession of a Strongly
Magnetized Neutron Star in the Magnetar 4U 0142+61”
Physical Review Letters 112, 171102 (2014). *Konami, S., Matsushita, K., Nagino, R., Tamagawa, T.:“Abundance Patterns in the Interstellar Medium of
Early-type Galaxies Observed with Suzaku” Astrophysical Journal 783, 8 (2014). *Sasano, M., Makishima, K., Sakurai, S., Zhang, Z., Enoto,
T.: “Suzaku view of the neutron star in the dipping
source 4U 1822-37” Publications of the Astronomical Society of Japan 66, 35 (2014) *Yamaguchi, H., Badenes, C., Petre, R., Nakano, T., Castro, D., Enoto, T., Hiraga, J. S., Hughes, J. P., Maeda,
Y., Nobukawa, M., Saﬁ-Harb, S., Slane, P. O., Smith,
R. K., Uchida, H.: “Discriminating the Progenitor Typeof Supernova Remnants with Iron K-shell Emission” Astrophysical Journal Letter 785, L27 (2014). *Wik, D. R., Hornstrup, A., Molendi, S., Madejski, G.,
Harrison, F. A., Zoglauer, A., Grefenstette, B. W.,
Gastaldello, F., Madsen, K. K., Westergaard, N. J., Fer-

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reira, D. D. M., Kitaguchi, T., Pedersen, K., Boggs,
S. E., Christensen, F. E., Craig, W. W., Hailey, C. J.,
Stern, D., Zhang, W. W.: “NuSTAR Observations of theBullet Cluster: Constraints on Inverse Compton Emission” Astrophysical Journal 792, 48 (2014). *Grefenstette, B. W., Harrison, F. A., Boggs, S. E.,
Reynolds, S. P., Fryer, C. L., Madsen, K. K., Wik, D.
R., Zoglauer, A., Ellinger, C. I., Alexander, D. M., An,
H., Barret, D., Christensen, F. E, Craig, W. W., Forster,K., Giommi, P., Hailey, C. J., Hornstrup, A., Kaspi, V.
M., Kitaguchi, T., Koglin, J. E., Mao, P. H., Miyasaka,
H., Mori, K., Perri, M., Pivovaroﬀ, M. J., Puccetti, S.,
Rana, V., Stern, D., Westergaard, N. J., Zhang, W. W.:“Asymmetries in core-collapse supernovae from maps ofradioactive 44 Ti in Cassiopeia A” Nature 506, 339-342(2014). *Kitaguchi, T., An, H., Beloborodov, A. M., Gotthelf, E.
V., Hayashi, T., Kaspi, V. M., Rana, V. R., Boggs, S.
E., Christensen, F. E., Craig, W. W., Hailey, C. J.,
Harrison, F. A., Stern, D., Zhang, W. W.: “NuSTAR
and Swift Observations of the Fast Rotating Magnetized
White Dwarf AE Aquarii” Astrophysical Journal 782, 3(2014). *Grefenstette, Brian W.; Reynolds, Stephen P.; Harrison, Fiona A.; Humensky, T. Brian; Boggs, Steven E.;
Fryer, Chris L.; DeLaney, Tracey; Madsen, Kristin K.;
Miyasaka, Hiromasa; Wik, Daniel R.; Zoglauer, Andreas; Forster, Karl; Kitaguchi, Takao; Lopez, Laura;
Nynka, Melania; Christensen, Finn E.; Craig, William
W.; Hailey, Charles J.; Stern, Daniel; Zhang, William
W.: “Locating the Most Energetic Electrons in Cassiopeia A” The Astrophysical Journal, 802, 15 (2015).
*
Wik, Daniel R.; Hornstrup, A.; Molendi, S.; Madejski,G.; Harrison, F. A.; Zoglauer, A.; Grefenstette, B. W.;
Gastaldello, F.; Madsen, K. K.; Westergaard, N. J.; Ferreira, D. D. M.; Kitaguchi, T.; Pedersen, K.; Boggs,
S. E.; Christensen, F. E.; Craig, W. W.; Hailey, C. J.;
Stern, D.; Zhang, W. W. “NuSTAR Observations of theBullet Cluster: Constraints on Inverse Compton Emission” The Astrophysical Journal,792,48(2014). *Maeda, Keiichi; Katsuda, Satoru; Bamba, Aya; Terada,
Yukikatsu; Fukazawa, Yasushi: “Long-lasting X-Ray
Emission from Type IIb Supernova 2011dh and Massloss History of the Yellow Supergiant Progenitor” The
Astrophysical Journal, 785, 95 (2014). *Serino, Motoko; Sakamoto, Takanori; Kawai, Nobuyuki;
Yoshida, Atsumasa; Ohno, Masanori; Ogawa, Yuji;
Nishimura, Yasunori; Fukushima, Kosuke; Higa,
Masaya; Ishikawa, Kazuto; Ishikawa, Masaki; Kawamuro, Taiki; Kimura, Masashi; Matsuoka, Masaru; Mihara, Tatehiro; Morii, Mikio; Nakagawa, Yujin E.;
Nakahira, Satoshi; Nakajima, Motoki; Nakano, Yuki;
Negoro, Hitoshi; Onodera, Takuya; Sasaki, Masayuki;
Shidatsu, Megumi; Sugimoto, Juri; Sugizaki, Mutsumi;

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Suwa, Fumitoshi; Suzuki, Kazuhiko; Tachibana, Yutaro; Takagi, Toshihiro; Toizumi, Takahiro; Tomida, Hiroshi; Tsuboi, Yohko; Tsunemi, Hiroshi; Ueda, Yoshihiro; Ueno, Shiro; Usui, Ryuichi; Yamada, Hisaki; Yamamoto, Takayuki; Yamaoka, Kazutaka; Yamauchi,
Makoto; Yoshidome, Koshiro; Yoshii, Taketoshi:“MAXI observations of gamma-ray bursts” Publicationsof the Astronomical Society of Japan,66,8714(2014) *Broersen, Sjors; Chiotellis, Alexandros; Vink, Jacco;Bamba, Aya: “The many sides of RCW 86: a TypeIa supernova remnant evolving in its progenitor’s windbubble” Monthly Notices of the Royal Astronomical Society,441,3040(2014) *Tanaka, Y. T.; Stawarz, .; Finke, J.; Cheung, C. C.; Dermer, C. D.; Kataoka, J.; Bamba, A.; Dubus, G.; De Naurois, M.; Wagner, S. J.; Fukazawa, Y.; Thompson, D. J.:“Extreme Blazars Studied with Fermi-LAT and Suzaku:
1ES 0347-121 and Blazar Candidate HESS J1943+213”
The Astrophysical Journal,787,155(2014). *Misawa, Toru; Inada, Naohisa; Oguri, Masamune;
Gandhi, Poshak; Horiuchi, Takashi; Koyamada, Suzuka;
Okamoto, Rina: “Resolving the Clumpy Structure of theOutﬂow Winds in the Gravitationally Lensed Quasar
SDSS J1029+2623” The Astrophysical Journal Letters,794,L20(2014). *“Discovery of Four Doubly Imaged Quasar Lenses fromthe Sloan Digital Sky Survey” Inada, Naohisa; Oguri,
Masamune; Rusu, Cristian E.; Kayo, Issha; Morokuma,
Tomoki: The Astronomical Journal,147,153(2014). *Tsuchiya, Harufumi: “Surrounding material eﬀect on measurement of thunderstorm-related neutrons” Astroparticle Physics,57,33(2014). *[Book・Proceedings]（Original Papers） *Subject to Peer Review
Wakabayashi, M., Komiya, K., Tamagawa, T., Takeuchi,
Y., Aoki, K., Taketani, A., Hamagaki, H.: “Development of a Diehard GEM using PTFE insulator substrate” Journal of Instrumentation 9, C3043 (2014). *Takeuchi, Y., Tamagawa, T., Kitagushi, T., Yamada, S.,
Iwakiri, W., Asami, F., Yoshikawa, A., Kaneko, K.,
Enoto, T., Hayato, A., Kohmura, T.: “Property of LCPGEM in Pure Dimethl Ether at Low Pressure” Journalof Instrumentation C01002 (2014). *Hill, Joanne E.; Black, J. Kevin; Emmett, Thomas J.;
Enoto, Teruaki; Jahoda, Keith M.; Kaaret, Philip;
Nolan, David S.; Tamagawa, Toru: “Design improvements and x-ray performance of a time projection chamber polarimeter for persistent astronomical sources”
Proceedings of the SPIE, 9144, 91441N (2014).
Jahoda, Keith M.; Black, J. Kevin; Hill, Joanne E.; Kallman, Timothy R.; Kaaret, Philip E.; Markwardt, Craig
B.; Okajima, Takashi; Petre, Robert; Soong, Yang;
Strohmayer, Tod E.; Tamagawa, Toru; Tawara, Yuzuru:“X-ray polarization capabilities of a small explorer mission” Proceedings of the SPIE, 9144, 91440N (2014).

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Hayashida, Kiyoshi; Yonetoku, Daisuke; Gunji, Shuichi;
Tamagawa, Toru; Mihara, Tatehiro; Mizuno, Tsunefumi; Takahashi, Hiromitsu; Dotani, Tadayasu; Kubo,
Hidetoshi; Yatsu, Yoichi; Tokanai, Fuyuku; Nakamori,Takeshi; Shibata, Shinpei; Hayato, Asami; Furuzawa,
Akihiro; Kishimoto, Yuji; Kitamoto, Shunji; Toma,
Kenji; Sadamoto, Masaaki; Yoshinaga, Keigo; Kim, Juyong; Ide, Shunichiro; Kamitsukasa, Fumiyoshi; Anabuki,
Naohisa; Tsunemi, Hiroshi; Katagiri, Jun; Sugimoto,
Juri: “X-ray gamma-ray polarimetry small satellite PolariS” Proceedings of the SPIE, 9144, 91440K (2014).
Nakazawa, Kazuhiro; Takahashi, Tadayuki; Watanabe,
Shin; Ichinohe, Yuto; Takeda, Shin’ichiro; Enoto, Teruaki; Fukazawa, Yasushi; Kamae, Tuneyoshi; Kokubun,
Motohide; Makishima, Kazuo; Mitani, Takefumi;
Mizuno, Tsunefumi; Nomachi, Masaharu; Tajima, Hiroyasu; Takashima, Takeshi; Tamagawa, Toru; Terada, Yukikatsu; Tashiro, Makoto; Uchiyama, Yasunobu;
Yoshimitsu, Tetsuo: “Sub-MeV all sky survey with acompact Si/CdTe Compton telescope” Proceedings of
the SPIE, 9144, 91440J (2014).
Kitaguchi, T., Tamagawa, T., Hayato, A., Enoto, T.,
Yoshikawa, A., Kaneko, K., Takeuchi, Y., Black, K.,
Hill, J., Jahoda, K., Krizmanic, J., Sturner, S., Griﬃths,S., Kaaret, P., Marlowe, H.: “Monte-Carlo estimationof the inﬂight performance of the GEMS satellite x-ray
polarimeter” Society of Photo-Optical Instrumentation
Engineers (SPIE) Conference Series, p.91444L (2014)
Takeuchi, Y., Kitaguchi, T., Hayato, A., Tamagawa, T.,
Iwakiri, W., Asami, F., Yoshikawa, A., Kaneko, K.,
Enoto, T., Black, K., Hill, J., Jahoda, K.: “Propertiesof the ﬂight model gas electron multiplier for the GEMS
mission” Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, p.91444N (2014)
Enoto, T., Black, J. K., Kitaguchi, T., Hayato, A., Hill, J.
E., Jahoda, K., Tamagawa, T., Kaneko, K., Takeuchi,
Y., Yoshikawa, A., Marlowe, H., Griﬃths, S., Kaaret,
P. E., Kenward, D., Khalid, S.: “Performance veriﬁcation of the Gravity and Extreme Magnetism Small
explorer (GEMS) x-ray polarimeter” Society of PhotoOptical Instrumentation Engineers (SPIE) Conference
Series, p.91444M (2014)
Hill, J. E., Black, J. K., Emmett, T. J., Enoto, T., Jahoda, K. M., Kaaret, P., Nolan, D. S., Tamagawa, T.:“Design improvements and x-ray performance of a time
projection chamber polarimeter for persistent astronomical sources” Society of Photo-Optical Instrumentation
Engineers (SPIE) Conference Series, p.91441N (2014)
Jahoda, K. M., Black, J. K., Hill, J. E., Kallman, T. R.,
Kaaret, P. E., Markwardt, C. B., Okajima, T., Petre, R.,
Soong, Y., Strohmayer, T. E., Tamagawa, T., Tawara,
Y.: “X-ray polarization capabilities of a small explorer
mission” Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, p.91440N (2014)2

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Oral Presentations(International Conference etc.)
Takayuki Yuasa, “A SPACEWIRE ROUTER ARCHITECTURE WITH NON-BLOCKING PACKET
TRANSFER MECHANISM”, International Space Wire
Conference, Athens, Greece, September (2014).
Takayuki Yuasa, “The origin of the Galactic Ridge X-ray
Emission”, East Asian Core Observatories Association
2015, Taipei, Taiwan, February (2015).
Hirofumi Noda, “Understanding X-ray Spectral and Timing Characteristics of Active Galactic Nuclei by Novel
Picture with Multiple Primary Emission” The X-ray
Universe 2014, Dublin, Ireland, June (2014).
Hirofumi Noda, “A Novel Picture of the AGN Central
Engine Derived with X-ray and Optical Simultaneous
Observations” COSPAR 2014, Moscow, Russia, August(2014).
Hirofumi Noda, “Novel Picuture of the AGN Central Engine Established by X-ray and Optical Simultaneous
Stuies” APRIM 2014, Deajeon, Koria, August (2014).
Toru Tamagawa, “GEM Production in Japan”, Invited
seminar, (National institute of nuclear and particle
physics (IN2P3)), Paris, France, August (2014).
Wataru B. Iwakiri, “Cosmic X-ray Study of the Physics
in Strong Magnetic Field and Expectation for GroundExperiments”, PLASMA 2014 (invited), Niigata, Japan,
November (2014).
Teruaki Enoto, “Astrophysical Observations and Future
Projects of Neutron Stars and Magnetars” 4th Joint
Meeting of the Nuclear Physics Divisions of the American Physical Society and the Physical Society of Japan,
Hawaii, USA, October (2014).
Teruaki Enoto, “Status Report Spectral Analysis Cookbook” ASTRO-H Science Meeting 12, Paris, France,
July (2014).
Teruaki Enoto, “Are Magnetars in X-ray Binaries? The
Slowest Rotating Accreting Neutron Star 4U 1954+319”
EWASS2014, Geneva, Switzerland, June (2014).
(Domestic Conference)吉川瑛文, 山田真也, 野田博文, 玉川徹: “「すざく」衛星を用いたブラックホール連星 Cygnus X-1 の high/soft 状態のハード成分の詳細解析” 日本天文学会 2014 年秋季年会,(日本天文学会), 山形, 9 月 (2014).
榎戸輝揚, 笹野理, 山田真也, 玉川徹, 牧島一夫ほか: “自転周期のきわめて遅いＸ線パルサー 4U 1954+319 のすざく観測” 日本天文学会 2014 年秋季年会, (日本天文学会), 山形,
9 月 (2014).
勝田哲, 森浩二, 大平豊, 常深博, 小山勝二, 中嶋大, 内田裕之, 上司文善, 馬場彩, 山崎了, 澤田真理, 坪根義雄, Petre
Robert, 玉川徹: “「チャンドラ」衛星による超新星残骸
RCW 86 南西端の再観測” 日本天文学会 2014 年秋季年会,(日本天文学会), 山形, 9 月 (2014).
山崎典子, 満田和久, 竹井洋, 辻本匡弘, 小川美奈, 杉田寛之, 佐 藤 洋 一, 篠 崎 慶 亮, 岡 本 篤, 藤 本 龍 一, 大 橋 隆 哉,
石 崎 欣 尚, 江 副 祐 一 郎, 山 田 真 也, 小 波 さ お り, 田 代 信,

- 489 -

寺田幸功, 瀬田裕美, 北本俊二, 星野晶夫, 玉川徹, 石川
久美, 野田博文, 佐藤浩介, 太田直美, 澤田真理, 三石郁之, 村上正秀, 村上弘志, 伊豫本直子, R.L. Kelley, C.A.
Kilbourne, F.S. Porter, K.R. Boyce, M. E. Eckart, M. P.
Chiao, M. A. Leutenegger, G.V. Brown, D. McCammon,
A. Szymkowiak, J.-W. den Herder, D. Haas, C. de Vries,
E. Costantini, H. Akamatsu, S.Paltani, 他 ASTRO-H
SXS チーム: “ASTRO-H 搭載精密軟 X 線分光装置 SXSの開発の現状 XII” 日本天文学会 2014 年秋季年会, (日本天文学会), 山形, 9 月 (2014).
岩切渉, 早藤麻美, 武内陽子, 玉川徹, 北口貴雄, 榎戸輝揚,
吉川瑛文, 金子健太, 窪田恵, 西田和樹, Keith Gendreau:“小 型 か つ 変 調 型 の X 線 発 生 装 置 Modulated X-ray
Source(MXS) の製作と性能評価” 日本天文学会 2014 年秋
季年会, (日本天文学会), 山形, 9 月 (2014).
林田清, 吉永圭吾, キムジュヨン, 井出舜一郎, 上司文善, 穴
吹直久, 常深博, 郡司修一, 柴田晋平, 片桐惇, 中森健之,
米徳大輔, 三原建弘, 玉川徹, 早藤麻美, 杉本樹梨, 高木利紘, 水野恒史, 高橋弘充, 谷津陽一, 堂谷忠靖, 斎藤芳隆, 古澤彰浩, 窪秀利, 當真賢二, 岸本祐二, Keith Jahoda, Joe
Hill, ほか PolariS-WG: “X 線ガンマ線偏光観測小型衛星
PolariS：開発の現状 2014” 日本天文学会 2014 年秋季年会, (日本天文学会), 山形, 9 月 (2014).
武内陽子, 玉川徹, 北口貴雄, 早藤麻美, 榎戸輝揚, 岩切渉, 吉川瑛文, 金子健太, 窪田恵, 西田和樹: “光電子追跡型 X 線
偏光計の製作および基礎性能評価” 日本天文学会 2014 年
秋季年会, (日本天文学会), 山形, 9 月 (2014).
湯浅孝行, 林多佳由, 石田学, 寺田幸功: “強磁場激変星 V1223
Sgr の鉄 Kα 輝線構造の時間変動解析” 日本天文学会 2014
年秋季年会, (日本天文学会), 山形, 9 月 (2014).
桑原啓介, 山田真也, 大橋隆哉, 野田博文: “狭輝線１型セイファート銀河 PG1244+026 の X 線時間変動解析” 日本天文学会 2014 年秋季年会, (日本天文学会), 山形, 9 月(2014).
河口賢至, 深沢泰司, 田中康之, 伊藤亮介, 川端弘治, 植村誠,
秋田谷洋, 神田優花, 峰崎岳夫, 野田博文, かなたチーム: “
かなた望遠鏡による活動銀河核の可視光・X 線・ガンマ線での相関の探査” 日本天文学会 2014 年秋季年会, (日本天文学会), 山形, 9 月 (2014).
野田博文, 牧島一夫, 山田真也, 中澤知洋, 三宅克馬: “セイファート NGC 3227 が示す巨大ブラックホールへの降着流の状態遷移” 日本天文学会 2014 年秋季年会, (日本天文学会), 山形, 9 月 (2014).
笹野理, 榎戸輝揚, 牧島一夫, 堂谷忠靖, 岩井將親: “「すざく」
による特異な低質量星と中性子星の連星 GRO J1744-28の観測” 日本天文学会 2014 年秋季年会, (日本天文学会),
山形, 9 月 (2014).
牧島一夫, 榎戸輝揚, 中澤知洋, 平賀純子, 中野俊男, 笹野理,
櫻井壮希, 村上浩章: “マグネター 4U 0142+61 における自由歳差運動の徴候 II” 日本天文学会 2014 年秋季年会, (日本天文学会), 山形, 9 月 (2014).
安田哲也, 田代信, 寺田幸功, 神頭知美, 岩切渉, 榎戸輝揚,
中川友進, 馬場彩, 浦田裕次, 柴田晋平, 牧島一夫, すざくWAM チーム: “すざく衛星搭載 WAM 検出器による AXP
1E1547.0-5408 の硬 X 線バーストの観測 (II)” 日本天文学

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS会 2014 年秋季年会, (日本天文学会), 山形, 9 月 (2014).
寺田幸功, 前田啓一, 玉川徹, 馬場彩, 高橋忠幸, 深沢泰司, 榎戸輝揚, 勝田哲: “「すざく」を用いた Ia 型超新星 SN2014Jの硬エックス線観測” 日本天文学会 2015 年春季年会, (日本天文学会), 大阪, 3 月 (2015).
辻本匡弘, 満田和久, 山崎典子, 竹井洋, 小川美奈, 杉田寛之, 佐 藤 洋 一, 篠 崎 慶 亮, 岡 本 篤, 藤 本 龍 一, 大 橋 隆 哉,
石 崎 欣 尚, 江 副 祐 一 郎, 山 田 真 也, 小 波 さ お り, 田 代 信,
寺田幸功, 瀬田裕美, 北本俊二, 星野晶夫, 玉川徹, 石川
久美, 野田博文, 佐藤浩介, 太田直美, 澤田真理, 三石郁之, 村上正秀, 村上弘志, 伊豫本直子, R. L. Kelley, C. A.
Kilbourne, F. S. Porter, K. R. Boyce, M. E. Eckart, M. P.
Chiao, M. A. Leutenegger, G.V. Brown, D. McCammon,
A. Szymkowiak, J.-W. den Herder, D. Haas, C. de Vries,
E. Costantini, H. Akamatsu, S.Paltani, ほか ASTRO-H
SXS チーム: “ASTRO-H 搭載精密軟 X 線分光装置 SXSの開発の現状 XIII” 日本天文学会 2015 年春季年会, (日本天文学会), 大阪, 3 月 (2015).
玉川徹, 早藤麻美, 北口貴雄, 榎戸輝揚, 岩切渉, 吉川瑛文, 武
内陽子, 窪田恵, 西田和樹, 田原譲, 幅良統, 林田清, 水野恒史, Keith Jahoda, Joanne Hill, ほか PRAXyS 衛星チー
ム: “X 線偏光観測衛星 PRAXyS” 日本天文学会 2015 年
春季年会, (日本天文学会), 大阪, 3 月 (2015).
窪田めぐ, 武内陽子, 西田和樹, 吉川瑛文, 金子健太, 榎戸輝揚,
早藤麻美, 北口貴雄, 岩切渉, 玉川徹, Keith M. Jahoda,
Joanne E. Hill, Kevin Black: “PRAXyS 衛星搭載に向けた光電効果型ガス偏光計の性能評価” 日本天文学会 2015
年春季年会, (日本天文学会), 大阪, 3 月 (2015).
北口貴雄, 玉川徹, 早藤麻美, 岩切渉, 窪田恵, 西田和樹, 武内
陽子, 榎戸輝揚, 武井大, 高山裕貴: “SPring-8 によるマイクロパターンガス偏光計の詳細な性能評価” 日本天文学会
2015 年春季年会, (日本天文学会), 大阪, 3 月 (2015).
中澤知洋, 国分紀秀, 佐藤悟朗, 川原田円, 佐藤理江, 渡辺伸,
高橋忠幸, 太田方之, 小高裕和, 武田伸一郎, 原山淳, 斉藤
新也, 湯浅孝行, 谷津陽一, 内山秀樹, 田島宏康, 山岡和貴,
深沢泰司, 水野恒史, 大野雅功, 高橋弘充, 勝田隼一郎, 寺
田幸功, 牧島一夫, 片岡淳, 野田博文, 榎戸輝揚, 田中孝明,
内山泰伸, 中森健之, Olivier Limousin, Philippe Laurent,
Francois Lebrun, 櫻井壮希, 笹野理, 中野俊男, 小林翔悟,
村上浩章, 小野光, 加藤佑一, 三宅克馬, 古田禄大, 室田優紀, 萩野浩一, 桂川美穂, 古井俊也, 枝廣育実: “ASTRO-H
衛星搭載硬 X 線撮像検出器 (HXI) の現状 FM の完成” 日本天文学会 2015 年春季年会, (日本天文学会), 大阪, 3 月(2015).
桑原啓介, 山田真也, 大橋隆哉, 野田博文: “狭輝線 1 型セイ
ファート銀河の X 線時間変動に対する特徴付けとその比較” 日本天文学会 2015 年春季年会, (日本天文学会), 大阪,
3 月 (2015).
野田博文, 峰崎岳夫, 牧島一夫, 中澤知洋, 諸隈智貴, 小久保充, 土居守, 河口賢至, 伊藤亮介, 川端弘治, 深沢泰司, 中尾
光, 渡辺誠, 森鼻久美子, 伊藤洋一, 斉藤嘉彦, 山田真也: “セイファート NGC 3516 の X 線と可視光の間に見られた光度変動の遅延” 日本天文学会 2015 年春季年会, (日本天文学会), 大阪, 3 月 (2015).
宮崎直人, 山田真也, 榎戸輝揚, 大橋隆哉: “「すざく」データ- 490 -を用いた微弱な輝線や吸収線の統計的評価方法” 日本天文学会 2015 年春季年会, (日本天文学会), 大阪, 3 月 (2015).
村上浩章, 牧島一夫, 榎戸輝揚, 古田禄大, 笹野理, 中野俊男,
櫻井壮希, 中澤知洋: “マグネター 4U 0142+61 における
自由歳差運動の徴候 IV” 日本天文学会 2015 年春季年会,(日本天文学会), 大阪, 3 月 (2015).
牧島一夫, 榎戸輝揚, 村上浩章, 古田禄大, 笹野理, 中野俊男,
中澤知洋: “マグネター歳差運動の二例目：「すざく」による 1E1547.0 － 5408 の結果” 日本天文学会 2015 年春季年
会, (日本天文学会), 大阪, 3 月 (2015).
中野俊男, 村上浩章, 古田禄大, 平賀純子, 牧島一夫, 金田英宏,
内山秀樹, 榎戸輝揚: “マグネター 1E 2259+586 と付随する超新星残骸 CTB109 の親星質量” 日本天文学会 2015 年
春季年会, (日本天文学会), 大阪, 3 月 (2015).
宮 武 広 直, Steve Bickerton, Alexie Leauthaud, Surhud
More, 岡 部 信 広, 高 田 昌 広, 大 栗 真 宗, 浜 名 崇, 宮 崎聡, Bob Armstrong, Jim Bosch, Robert Lupton, Paul
Price, 梅津敬一, Rachel Mandelbaum, Melanie Simet, 内海洋輔, 西澤淳, 大倉悠貴, ほか HSC weak lensing analysis
team: “Hyper Suprime-Cam における銀河形状測定の系
統誤差の評価” 日本天文学会 2015 年春季年会, (日本天文学会), 大阪, 3 月 (2015).
北口貴雄，玉川徹，早藤麻美，榎戸輝揚，岩切渉，吉川瑛文，
金子健太，武内陽子，窪田恵，西田和樹: “X 線の直線偏
光・分光・到達時間を測定できるマイクロパターンガス検出器の開発”, 日本物理学会 2014 年秋季大会, (日本物理学会), 佐賀, 9 月 (2014).
窪田恵, 早藤麻美, 北口貴雄, 武内陽子, 榎戸輝揚, 岩切渉, 金子健太, 西田和樹, 吉川瑛文, 玉川徹: “変調型 X 線源を用いたジメチルエーテル中での電子輸送特性の測定” 日本物理学会 2014 年秋季大会, (日本物理学会), 佐賀, 9 月 (2014).
小宮一毅, 藤原康平, 小林丈士, 若林正毅, 玉川徹, 武内陽子, 浜垣秀樹: “新しい絶縁材料を用いた GEM の開発” 日本物理学会 2014 年秋季大会, (日本物理学会), 佐賀, 9 月(2014).
牧島一夫, 榎戸輝揚, 村上浩章, 平賀純子, 中野俊男, 中澤知洋, 櫻井壮希, 笹野理: “「すざく」で探るマグネター 4U
0142+61 における中性子星の自由歳差運動と磁気変形 II”
日本物理学会 2014 年秋季大会, (日本物理学会), 佐賀, 9 月(2014).
楳本大悟, 土屋晴文, 榎戸輝揚, 湯浅孝行, 山田真也, 中澤知洋, 牧島一夫: “GROWTH 実験で 2012 年に検出された北陸冬季雷雲からの対消滅線” 日本物理学会 2014 年秋季大会, (日本物理学会), 佐賀, 9 月 (2014).
早藤麻美, 北口貴雄, 岩切渉, 玉川徹, 武内陽子, 窪田恵, 西田
和樹, 榎戸輝揚: “宇宙観測を目的とした TPC 型 X 線偏光計の性能評価試験” 日本物理学会第 70 回年次大会, (日本物理学会), 早稲田, 3 月 (2015).
岩切渉, 北口貴雄, 早藤麻美, 玉川徹, 武内陽子, 窪田恵, 西田和樹, 榎戸輝揚, Keith M. Jahoda, Joanne E. Hill, J.
Kevin Black: “PRAXYS 衛星搭載 X 線偏光計のシンクロ
トロン放射光を用いた性能評価” 日本物理学会第 70 回年次大会, (日本物理学会), 早稲田, 3 月 (2015).
石崎欣尚, 満田和久, 山崎典子, 竹井洋, 辻本匡弘, 小川美奈 , 杉 田 寛 之, 佐 藤 洋 一 , 篠 崎 慶 亮, 岡 本 篤 , 藤 本 龍 一,

4

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

大 橋 隆 哉, 江 副 祐 一 郎, 山 田 真 也, 小 波 さ お り, 田 代 信,
寺田幸功, 瀬田裕美, 北本俊二, 星野晶夫, 玉川徹, 石川
久美, 野田博文, 佐藤浩介, 太田直美, 澤田真理, 三石郁之, 村上正秀, 村上弘志, 伊豫本直子, R.L. Kelley, C.A.
Kilbourne, F.S. Porter, K.R. Boyce, M. E. Eckart, M. P.
Chiao, M. A. Leutenegger, G.V. Brown, D. McCammon,
A. Szymkowiak, J.-W. den Herder, D. Haas, C. de Vries,
E. Costantini, H. Akamatsu, S.Paltani, 他 ASTRO-H
SXS チーム: “ASTRO-H 搭載 精密軟 X 線分光装置 SXSの開発の現状 (VI)” 日本物理学会第 70 回年次大会, (日本物理学会), 早稲田, 3 月 (2015).
楳本大悟, 土屋晴文, 湯浅孝行, 中澤知洋, 榎戸輝揚, 古田録大, 山田真也, 牧島一夫: “GROWTH 実験 1：2014 年末に新規設置した雷雲ガンマ線検出器と初期成果” 日本物理学会第 70 回年次大会, (日本物理学会), 早稲田, 3 月 (2015).
古田禄大, 楳本大悟, 土屋晴文, 湯浅孝行, 中澤知洋, 榎戸輝
揚, 山田真也, 牧島一夫: “GROWTH 実験 2：2014-2015
冬に観測された雷由来ガンマ線の詳細解析” 日本物理学会
第 70 回年次大会, (日本物理学会), 早稲田, 3 月 (2015).
橋 本 直, D.A. Bennett, C. Curceanu, W.B Doriese, J.W.
Fowler, J. Gard, F.P. Gustafsson, 早 野 龍 五, 施 赫 將,
M. Iliescu, 石 元 茂, 板 橋 健 太, 岩 崎 雅 彦, 桑 原 啓 介, J.
Marton, 野 田 博 文, G.C. O ’Neil, 岡 田 信 二, 應 田 治 彦,
C.D. Reintsema, 佐藤将春, D.R. Schmidt, 鈴木謙, 鈴木
隆敏, D.S. Swetz, 竜野秀行, F，J. Uhlig, J.N. Ullom, E.
Widmann, 山田真也, J. ZmeskalH: “K 中間子原子 X 線分
光に向けた超伝導遷移端マイクロカロリメータのπ-ビーム
試験” 日本物理学会第 70 回年次大会, (日本物理学会), 早稲田, 3 月 (2015).
竜野秀行, D.A. Bennett, C. Curceanu, W.B Doriese, J.W.
Fowler, J. Gard, F.P. Gustafsson, 橋本直, 早野龍五, 施
赫將, M. Iliescu, 石元茂, 板橋健太, 岩崎雅彦, 桑原啓介,
J. Marton, 野 田 博 文, G.C. O ’Neil, 岡 田 信 二, 應 田 治
彦, C.D. Reintsema, 佐藤将春, D.R. Schmidt, A. Scordo,
鈴木謙, 鈴木隆敏, D.S. Swetz, J. Uhlig, J.N. Ullom, E.
Widmann, 山田真也, J. Zmeskal: “荷電粒子ビーム環境における超伝導遷移端マイクロカロリメータ X 線検出器の性能評価” 日本物理学会第 70 回年次大会, (日本物理学会),
早稲田, 3 月 (2015).
岡田信二, D.A. Bennett, C. Curceanu, W.B Doriese, J.W.
Fowler, J. Gard, F.P. Gustafsson, 橋本直, 早野龍五, 施赫 將, M. Iliescu, 石 元 茂, 板 橋 健 太, 岩 崎 雅 彦, 桑 原 啓介, J. Marton, 野田博文, G.C. O ’Neil, 應田治彦, C.D.
Reintsema, 佐 藤 将 春, D.R. Schmidt, 鈴 木 謙, 鈴 木 隆
敏, D.S. Swetz, 竜 野 秀 行, F，J. Uhlig, J.N. Ullom, E.
Widmann, 山田真也, J. Zmeskal: “超伝導遷移端マイクロ
カロリメータを用いた K 中間子原子 X 線精密分光実験”
日本物理学会第 70 回年次大会, (日本物理学会), 早稲田, 3
月 (2015).
田島宏康, 深沢泰司, 渡辺伸, 内山秀樹, 内山泰伸, 榎戸輝揚,
太田方之, 大野雅功, 小高裕和, 片岡淳, 川原田円, 国分紀秀,
佐藤悟朗, 佐藤理江, 高橋忠幸, 高橋弘充, 武田伸一郎, 田
代信, 田中孝明, 寺田幸功, 中澤知洋, 中森健之, 林克洋, 原
山淳, Roger Blandford, 牧島一夫, Grzegorz Madejski, 水野恒史, 森國城, 谷津陽一, 山岡和貴, 山田真也, 湯浅孝行,- 491 -

米徳大輔, Philippe Laurent, Olivier Limousin, Fran ois
Lebrun, ほか ASTRO-H SGD チーム: “ASTRO-H 衛星搭載軟ガンマ線検出器の衛星搭載器試験結果” 日本物理学会第 70 回年次大会, (日本物理学会), 早稲田, 3 月 (2015).
玉川 徹, 早藤麻美, 北口貴雄, 榎戸輝揚, 岩切渉, 林田 清,
水野恒史, 吉川瑛文, 武内陽子, 窪田恵, 西田和樹, Keith
Jahoda, Joanne Hill, 田原譲, 幅良統, ほか PRAXyS チー
ム: “X 線偏光観測衛星 PRAXYS の提案” 宇宙科学シンポジウム, (宇宙航空研究開発機構 宇宙科学研究所), 相模
原, 1 月 (2015).
石川久美, “瞳再配置法高コントラスト干渉計イメージング”
地球型惑星観測装置ワークショップ, 定山渓, 2 月 (2014).
石川久美, “「すざく」XIS による地球外圏からの軟 X 線放射の系統探査” 全天軟 X 線放射研究会, (理化学研究所), 和
光市, 5 月 (2014).
石川久美, “X 線観測レビュー” 地球磁気圏 X 線可視化に関する研究会, (首都大学東京), 東京, 11 月 (2014)
榎戸輝揚, “マグネターの時期活動と X 線観測” 第二回 DTA
シンポジウム (招待講演), (国立天文台), 三鷹, 10 月 (2014)
榎戸輝揚, “マグネターと将来の突発天体観測” 高宇連将来計
画シンポジウム, (宇宙科学研究所), 淵野辺, 8 月 (2014)
榎 戸 輝 揚, “中 性 子 星・バ イ ナ リ ー 等 の MeV 放 射: 100
keV–100 MeV の話題” 高宇連将来計画シンポジウム, (宇宙科学研究所), 淵野辺, 8 月 (2014)
玉川 徹, “今後 20 年間の X 線・ガンマ線偏光観測ミッショ
ンと準備状況” 高宇連将来計画シンポジウム, (宇宙科学研究所), 淵野辺, 8 月 (2014)

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Astro-Glaciology Research Unit
Publications[Journal](Original Papers)*Subject to Peer Review
Sigl M., McConnell J., Toohey M., Curran M., Das S.,
Edwards R., Isaksson E., Kawamura K., Kipfstuhl S.,
Krüger K., Layman L., Maselli O., Motizuki Y.,
Motoyama H., Pasteris D., Severi M.: “Insights from
Antarctica on volcanic forcing during the Common Era”,
Nature Climate Change, 4, 693–697,(2014). *Okamoto S., Takahashi K., Nakai Y., Motizuki Y., Makabe
A., Koba K., Motoyama H.: “Measurement of nitrogenand oxygen isotope ratios in considerably low nitrateconcentration ice core samples”, RIKEN Accel. Prog. Rep.
47, 139, (2014).*
Miyake F., Suzuki A., Masuda K., Horiuchi K., Motoyama
H., Matsuzaki H., Motizuki Y., Takahashi K., Nakai Y.:“Cosmic ray event of AD 774-775 shown in quasi-annual
10Be data from the Antarctic Dome Fuji ice core”,
Geophysical Research Letters, 42, 84-89, (2015).*
Oral Presentations(International Conference etc.)
Motizuki Y., Motoyama H., Nakai Y., Suzuki K., Iizuka Y.,
Takahashi
K.:“Chemical
composition
anduniquecharacteristics of shallow ice core samples from a
Dome Fuji core (Antarctica) drilled in 2001” (A poster
presentation), The 38th International Symposium on
Environmental Analytical Chemistry, Lausannne,
Switzerland, June.(2014).
(Domestic Conference)
田邊健茲, 望月優子 : “共生星 R Aquarii の 1073/1074 年新星爆発に対する地質学的痕跡”, 日本天文学会 2014 年秋季
年会, 山形, 9 月(2014).
三宅芙沙, 鈴木麻未, 増田公明, 堀内一穂, 本山秀明, 松崎
浩之, 望月優子, 高橋和也, 中井陽一.: ”南極アイスコア中
10Be 濃度を用いた西暦 774-775 年宇宙線イベントの調査”,
日本物理学会 2014 年秋季大会, 佐賀, 9 月(2014).
藤田秀二, 東久美子, 飯塚芳徳, 平林幹啓, 堀 彰, 望月優子,
本山秀明.: ”東南極ドームふじ近傍で掘削された複数の浅層コアのフィルンの生成・変態・変形”, 雪氷研究大会, 八戸, 9 月(2014).
望月優子 : ”アイスコアと宇宙からのシグナル”, 総研大・学
融合「生命概念の普遍化ー宇宙の生命」第６回研究会, 三浦郡, 12 月(2014).
望月優子: “DF01 浅層コアの硝酸イオンプロファイルと宇宙からのシグナル”, ドームふじアイスコアコンソーシアム
ICC 研究集会, 立川, 3 月(2014).
高橋和也, 望月優子, 中井陽一.: “ドームふじ浅層コアのイオ
ン及び硝酸同位体の詳細解析の現状と今後について”, ドームふじアイスコアコンソーシアム ICC 研究集会, 立川,
3 月(2014).

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Superheavy Element Production Team
Publications[Journal](Original Papers)*Subject to Peer Review
J. Even, A. Yakushev, Ch. E. Düllmann, H. Haba, M. Asai,
T. K. Sato, H. Brand, A. Di Nitto, R. Eichler, F. L. Fan,
W. Hartmann, M. Huang, E. Jäger, D. Kaji, J. Kanaya,
Y. Kaneya, J. Khuyagbaatar, B. Kindler, J. V. Kratz, J.
Krier, Y. Kudou, N. Kurz, B. Lommel, S. Miyashita, K.
Morimoto, K. Morita, M. Murakami, Y. Nagame, H.
Nitsche, K. Ooe, Z. Qin, M. Schädel, J. Steiner, T.
Sumita, M. Takeyama, K. Tanaka, A. Toyoshima, K.
Tsukada, A. Türler, I. Usoltsev, Y. Wakabayashi, Y.
Wang, N. Wiehl, S. Yamaki, ”Synthesis and detection ofa seaborgium carbonyl complex”,Science 345, 1491
(2014).
D. Kaji, K. Morimoto, F. Tokanai“Beam intensity monitor based on gas scintillation
emitted from helium gas molecules in a gas-filled recoil
ion separator”, Nucl. Instr. and Meth. B317, 311 (2014),
M. Huang, H. Haba, M. Murakami, M. Asai, D. Kaji, J.
Kanaya, Y. Kasamatsu, H. Kikunaga, Y. Kikutani, Y.
Komori, H. Kudo, Y. Kudou, K. Morimoto, K. Morita, K.
Nakamura, K. Ozeki, R. Sakai, A. Shinohara, T. Sumita,
K. Tanaka, A. Toyoshima, K. Tsukada, Y. Wakabayashi,and A. Yoneda ， ”Production of 88Nb and 170Ta forchemical studies of element 105, Db, using the GARIS
gas-jet system”，J. Radioanal. Nucl. Chem.，304 845-849，(2015).
H. Haba, M. Huang, D. Kaji, J. Kanaya, Y. Kudou, K.
Morimoto, K. Morita, M. Murakami, K. Ozeki, R. Sakai,T. Sumita, Y. Wakabayashi, A. Yoneda, Y. Kasamatsu,
Y. Kikutani, Y. Komori, K. Nakamura, A. Shinohara, H.
Kikunaga, H. Kudo, K. Nishio, A. Toyoshima, and T.
Tsukada，“Production of 262Db in the 248Cm(19F,5n)262Db
reaction and decay properties of 262Db and 258Lr”, Phys.
Rev. C，89, 024618/1-11，2014[Book · Proceedings](Original Papers)*Subject to Peer Review
D. Kaji, K. Morimoto, H. Haba, Y. Wakabayashi, Y. Kudou,
M. Huang, S. Goto, M. Murakami, N. Goto, T. Koyama,
N. Tamura, S. Tsuto, T. Sumita, K. Tanaka, M.
Takeyama, S. Yamaki, K. Morita, “Startup of a new gasfilled recoil separator GARIS-II”, J. Radioanal. Nucl.
Chem., (2014) 303: 1523-1525
Daiya KAJI, Kouji MORIMOTO, Hiromitsu HABA, Yasuo
WAKABAYASHI, Yuki KUDOU, Minghui HUANG,
Shin-ichi GOTO, Masashi MURAKAMI, Naoya GOTO,
Takumi KOYAMA, Nobuyuki TAMURA, Shouhei
TSUTO, Takayuki SUMITA, Kengo TANAKA, Mirei
TAKEYAMA, Sayaka YAMAKI, and Kosuke MORITA“Research and development of a new gas-filled recoil
separator GARIS-II”, JPS Conf. Proc., 013051 (2014)
Oral Presentations(International Conference etc.)

D. Kaji, NUSTAR meeting 2014, “SHE experiments withGARIS-I/-II at RIKEN”, (Invited talk)
K. Morita, 2nd Conference on Advances in Redioactive
Isotope Science (ARIS2014), (Invited talk), June 4, 2014,
Tokyo, Japan, ‘Research of Superheavy Elements at
RIKEN - Present Status and Perspective –’K. Morita, Zakopane Conference on Nuclear Physics,
Invited talk Sep. 3, 2014, Zakopane, Poland, ‘Researchon Superheavy Element at RIKEN
K. Morita, K. Morimoto, D. Kaji, H. Haba, K. Ozeki, Y.
Kudou, Y. Wakabayashi, A. Yoneda, A. Yoshida, T.
Ohnishi, Y. Kasamatsu, H. Hasebe, M.-H. Huang, J.
Kanaya, R. Kanungo, K. Katori, T. Sumita, K. Tanaka,
T. Yamaguchi, T. Akiyama, R. Sakai, S. Yamaki, H.
Kudo, S. Goto, M. Murakami, Y. Kariya, H.-S. Xu , T. H.
Huang, Z. Gan, L. Ma, E. Ideguchi, T. Suda, H.
Kikunaga, N. Sato, H. Koura, S. Mitsuoka, M. Asai, F.
Tokanai, T. Moritani, K. Mayama, M. Takeyama, S.
Namai, A. Mashiko, A. Ozawa, K. Sueki, Y.-L. Zhao, H.
Geissel, S. Hofmann, Y. Maurer, K. Fujita, Y. Narikiyo,
T. Tanaka, and S. Yamamoto, JPS-APS Joint meeting on
Nuclear Physics Division, Oct. 9, 2014, Hawaii, U.S.A.
D. Kaji, ”Performance of New Gas-filled Recoil Ion
Separator GARIS-II for Asymmetric Fusion Reaction”,
Tokyo, June, 2014, ARIS2014
D. Kaji, ”The first α -γ spectroscopic study by using a Si-Ge
detector array installed at the focal plane of GARIS”,
Tokyo, June, 2014, ARIS 2014,
D. Kaji, ”Present status of superheavy element production
target for gas-filled recoil separators GARIS and GARISII”, Tokyo, Aug. 2014, INTD2014
Yamaki S., Morimoto K., Kaji D., Wakabayashi Y., et al.,“Pulse Shape Analysis Using Flash-ADC for Short-lived
Decay of Super Heavy Elements”, ARIS2014, Tokyo,
June (2014).
(Domestic Conference)
山木さやか: “Flash-ADC により取得したプリアンプ波形のための解析アルゴリズムの開発”, 日本物理学会第 69 回
年次大会, (日本物理学会), 平塚市、東海大学, 3 月(2014)
加治大哉, “GARIS-II commissioning #3”、 平塚市、東海大学, 3 月(2014),第 69 回 日本物理学会
新井郁也，和田道治，Peter Schury，伊藤由太，片山一郎，園田哲，Mikael Reponen，高峰愛子，加治大哉，森本幸司，羽場宏光，森田浩介，Hermann Wollnik, “理研GARIS-IIにおけるイオンサーフィン型RFカーペットガス
セルの性能評価”,第70回年次大回 日本物理学会 早稲
田大学 2015年3月
加治大哉, ”GARISを用いたホットフュージョン反応
248
Cm+48Ca→296Lv* に関する研究”, 名古屋、2014 年 9 月,
第 58 回放射化学討論会,
加治大哉, ”気体充填型反跳分離装置 GARIS-II の非対称系反応に対する性能試験”, 名古屋、2014 年 9 月,第 58 回
放射化学討論会,
加治大哉, ”GARIS を用いた 113 番元素研究の総括”,名古屋、2014 年 9 月, 第 58 回放射化学討論会,
加治大哉,”超重核研究のための焦点面検出器の開発”, 名
古屋、2014 年 9 月,第 58 回放射化学討論会,- 493 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

森本幸司: ”加速器を用いた新元素探索の最前線”, 第 23
理化学研究所里庄セミナー、岡山県、８月(2014)
一般向け講演会
森田浩介、大阪大学理学部物理学科セミナー 2014 年 7 月
25 日 豊中市‘新元素の探索－現代の錬金術－’森田浩介、日本耳鼻咽喉科学会学術講演会 2014 年 5 月 16
日 福岡市 ‘113 番元素発見への道のり’
森田浩介、福岡県高校理科部会夏季研修会講演会 2014 年 8
月 20 日福岡市‘113 番新元素の探索’
森田浩介、科学を語る会講演会 2014 年 11 月 8 日 福岡市‘新元素の探索－現代の錬金術－’森田浩介、理化学研究所、研究員幹事会総会講演会 2015 年
3 月 6 日 和光市 ‘113 番新元素の探索- 494 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Superheavy Element Research Device Development Team
Publications[Journal](Original Papers)*Subject to Peer Review
J. Even, A. Yakushev, Ch. E. Düllmann, H. Haba, M. Asai,
T. K. Sato, H. Brand, A. Di Nitto, R. Eichler, F. L. Fan,
W. Hartmann, M. Huang, E. Jäger, D. Kaji, J. Kanaya,
Y. Kaneya, J. Khuyagbaatar, B. Kindler, J. V. Kratz, J.
Krier, Y. Kudou, N. Kurz, B. Lommel, S. Miyashita, K.
Morimoto, K. Morita, M. Murakami, Y. Nagame, H.
Nitsche, K. Ooe, Z. Qin, M. Schädel, J. Steiner, T.
Sumita, M. Takeyama, K. Tanaka, A. Toyoshima, K.
Tsukada, A. Türler, I. Usoltsev, Y. Wakabayashi, Y.
Wang, N. Wiehl, S. Yamaki, ”Synthesis and detection ofa seaborgium carbonyl complex”,Science 345, 1491
(2014).
D. Kaji, K. Morimoto, F. Tokanai“Beam intensity monitor based on gas scintillation
emitted from helium gas molecules in a gas-filled recoil
ion separator”, Nucl. Instr. and Meth. B317, 311 (2014),
M. Huang, H. Haba, M. Murakami, M. Asai, D. Kaji, J.
Kanaya, Y. Kasamatsu, H. Kikunaga, Y. Kikutani, Y.
Komori, H. Kudo, Y. Kudou, K. Morimoto, K. Morita, K.
Nakamura, K. Ozeki, R. Sakai, A. Shinohara, T. Sumita,
K. Tanaka, A. Toyoshima, K. Tsukada, Y. Wakabayashi,and A. Yoneda ， ”Production of 88Nb and 170Ta forchemical studies of element 105, Db, using the GARIS
gas-jet system”，J. Radioanal. Nucl. Chem.，304 845-849，(2015).
H. Haba, M. Huang, D. Kaji, J. Kanaya, Y. Kudou, K.
Morimoto, K. Morita, M. Murakami, K. Ozeki, R. Sakai,T. Sumita, Y. Wakabayashi, A. Yoneda, Y. Kasamatsu,
Y. Kikutani, Y. Komori, K. Nakamura, A. Shinohara, H.
Kikunaga, H. Kudo, K. Nishio, A. Toyoshima, and T.
Tsukada，“Production of 262Db in the 248Cm(19F,5n)262Db
reaction and decay properties of 262Db and 258Lr”, Phys.
Rev. C，89, 024618/1-11，2014[Book · Proceedings](Original Papers)*Subject to Peer Review
D. Kaji, K. Morimoto, H. Haba, Y. Wakabayashi, Y. Kudou,
M. Huang, S. Goto, M. Murakami, N. Goto, T. Koyama,
N. Tamura, S. Tsuto, T. Sumita, K. Tanaka, M.
Takeyama, S. Yamaki, K. Morita, “Startup of a newgas-filled recoil separator GARIS-II”, J. Radioanal.
Nucl. Chem., (2014) 303: 1523-1525
Daiya KAJI, Kouji MORIMOTO, Hiromitsu HABA, Yasuo
WAKABAYASHI, Yuki KUDOU, Minghui HUANG,
Shin-ichi GOTO, Masashi MURAKAMI, Naoya GOTO,
Takumi KOYAMA, Nobuyuki TAMURA, Shouhei
TSUTO, Takayuki SUMITA, Kengo TANAKA, Mirei
TAKEYAMA, Sayaka YAMAKI, and Kosuke MORITA“Research and development of a new gas-filled recoil
separator GARIS-II”, JPS Conf. Proc., 013051 (2014)

D. Kaji, NUSTAR meeting 2014, “SHE experiments withGARIS-I/-II at RIKEN”, (Invited talk)
K. Morita, K. Morimoto, D. Kaji, H. Haba, K. Ozeki, Y.
Kudou, Y. Wakabayashi, A. Yoneda, A. Yoshida, T.
Ohnishi, Y. Kasamatsu, H. Hasebe, M.-H. Huang, J.
Kanaya, R. Kanungo, K. Katori, T. Sumita, K. Tanaka,
T. Yamaguchi, T. Akiyama, R. Sakai, S. Yamaki, H.
Kudo, S. Goto, M. Murakami, Y. Kariya, H.-S. Xu , T. H.
Huang, Z. Gan, L. Ma, E. Ideguchi, T. Suda, H.
Kikunaga, N. Sato, H. Koura, S. Mitsuoka, M. Asai, F.
Tokanai, T. Moritani, K. Mayama, M. Takeyama, S.
Namai, A. Mashiko, A. Ozawa, K. Sueki, Y.-L. Zhao, H.
Geissel, S. Hofmann, Y. Maurer, K. Fujita, Y. Narikiyo,
T. Tanaka, and S. Yamamoto, JPS-APS Joint meetingon Nuclear Physics Division, Oct. 9, 2014, Hawaii,
U.S.A.
D. Kaji, ”Performance of New Gas-filled Recoil Ion
Separator GARIS-II for Asymmetric Fusion Reaction”,
Tokyo, June, 2014, ARIS2014
D. Kaji, ”The first α -γ spectroscopic study by using a
Si-Ge detector array installed at the focal plane of
GARIS”, Tokyo, June, 2014, ARIS 2014,
D. Kaji, ”Present status of superheavy element production
target for gas-filled recoil separators GARIS andGARIS-II”, Tokyo, Aug. 2014, INTD2014
S. Yamaki, K. Morimoto, D. Kaji,Y. Wakabayashi, et al.,“Pulse Shape Analysis Using Flash-ADC for Short-lived
Decay of Super Heavy Elements”, ARIS2014, Tokyo,
June (2014).
(Domestic Conference)
山木さやか: “Flash-ADC により取得したプリアンプ波形のための解析アルゴリズムの開発”, 日本物理学会第 69 回
年次大会, (日本物理学会), 平塚市、東海大学, 3 月(2014)
加治大哉, “GARIS-II commissioning #3”、 平塚市、東海大学, 3 月(2014),第 69 回 日本物理学会
新井郁也，和田道治，Peter Schury，伊藤由太，片山一郎，
園田哲，Mikael Reponen，高峰愛子，加治大哉，森本幸司，
羽場宏光，森田浩介，Hermann Wollnik, “理研GARIS-IIにおけるイオンサーフィン型RFカーペットガスセルの性能評価”,第70回年次大回 日本物理学会 早稲田大学
2015年3月
加治大哉, ”GARISを用いたホットフュージョン反応
248
Cm+48Ca→296Lv* に関する研究”, 名古屋、2014 年 9 月,
第 58 回放射化学討論会,
加治大哉, ”気体充填型反跳分離装置 GARIS-II の非対称系反応に対する性能試験”, 名古屋、2014 年 9 月,第 58 回放射化学討論会,
加治大哉, ”GARIS を用いた 113 番元素研究の総括”,名古屋、2014 年 9 月, 第 58 回放射化学討論会,
加治大哉,”超重核研究のための焦点面検出器の開発”, 名
古屋、2014 年 9 月,第 58 回放射化学討論会,
森本幸司: ”加速器を用いた新元素探索の最前線”, 第 23
理化学研究所里庄セミナー、岡山県、８月(2014)

Oral Presentations(International Conference etc.)- 495 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Accelerator Group
Publications[Journal]（Original Papers） *Subject to Peer Review
Kuboki H., Okuno H., Hasebe H., Fukunishi N., Ikezawa
E., Imao H., Kamigaito O., and Kase M.: “Charge state
distribution of 86 Kr in hydrogen and helium gas charge
strippers at 2.7 MeV/nucleon”, Phys. Rev. ST Accel.
Beams 17, 123501 (2014). ＊Ohnishi J., Okuno H., Nakamura M.: “Support Structure of Cold-Mass for Superconducting Ring Cyclotron
and Electromagnetic Force Measurements with Strain
Gauges”, IEEE Trans. Applied Superconductivity 24,
4000504 (2014). ＊Ozeki K., Higurashi Y., Kidera M., and Nakagawa T.:“Note: Eﬀect of hot liner in producing 40,48 Ca beamfrom RIKEN 18-GHz electron cyclotron resonance ionssource”, Rev. Sci. Instrum. 86, 016114 (2015). ＊Maeyama T., Fukunishi N., Ishikawa K.L., Furuta
T., Fukasaku K., Takagi S., Noda S., Himeno R.,
and Fukuda S.: “Radiological characteristics of MRIbased VIP polymer gel under carbon beam irradiation”,
Radiation Physics and Chemistry 107, p. 7–11 (2015).
（Others） *Subject to Peer Review
前山拓哉, 福西暢尚, 石川顕一, 古田琢哉, 深作和明, 高木周,野田茂穂, 姫野龍太郎, 福田茂一: “VIP ポリマーゲル線量計による炭素線線量分布評価手法の検討”, 放射線化学 98,
p. 11–15 (2014).
[Book・Proceedings]（Original Papers） *Subject to Peer Review
Lu L., Kamigaito O., Sakamoto N., Suda K., Yamada
K.: “Design of a Triple-Spoke Cavity as a Rebuncher
for RIKEN RI-Beam Factory”, Proceedings of the
16th International Conference on RF Superconductivity(SRF2013), p. 988–990 (2014).
Ohnishi J., Okuno H., Nakamura M.: “Design of New Superconducting Ring Cyclotron for the RIBF”, Proceedings of the 20th International Conference on Cyclotrons
and their Applications (Cyclotrons’13), p. 79 (2014).
Sakamoto N., Fujimaki M., Fukunishi N., Higurashi Y.,
Kamigaito O., Okuno H., Suda K., Watanabe T.,
Watanabe Y., Yamada K., Koyama R.: “Performanceof New Injector RILAC2 for RIKEN RI-Beam Factory”,
Proceedings of the 27th Linear Accelerator Conference(LINAC14), p. 1123–1126 (2015).
Suda K., Ikezawa E., Kamigaito O., Sakamoto N., Yamada
K., Touchi Y.: “Construction of the New Ampliﬁers for
the RIKEN-LINAC”, Proceedings of the 27th Linear Accelerator Conference (LINAC14), p. 339–341 (2015).
Watanabe T., Fukunishi N., Kase M., Kamigaito O.,
Inamori S., Kon K.: “Improvements of Beam Current
Monitor by using a High Tc Current Sensor and SQUID
at the RIBF”, Journal of Physics: Conf. Series 507,
042047 (2014).

- 496 -

Yamada K., Kamigaito O., Sakamoto N., Suda K.: “Conceptual Design of SC Linac for RIBF-Upgrade Plan”,
Proceedings of the 16th International Conference on RF
Superconductivity (SRF2013), p. 137–139 (2014).
Yamada K., Suda K., Sakamoto N., Kamigaito O.: “Design of a New Superconducting Linac for the RIBF Upgrade”, Proceedings of the 27th Linear Accelerator Conference (LINAC14), p. 1127–1130 (2015).
池沢英二, 小山田和幸, 大木智則, 山内啓資, 田村匡史,
遊佐陽, 金子健太, 渡邉裕, 坂本成彦, 須田健嗣, 山田一成,
加瀬昌之, 上垣外修一: “理研重イオンリニアックの現状報
告”, Proceedings of the 11th Annual Meeting of Particle
Accelerator Society of Japan, p. 398–400 (2014).
内山暁仁, 込山美咲, 福西暢尚: “RIBF におけるビームサー
ビ ス 時 間 可 視 化 シ ス テ ム の 実 装”, Proceedings of the
11th Annual Meeting of Particle Accelerator Society ofJapan, p. 767–770 (2014).
大関和貴, 日暮祥英, 中川孝秀: “理研 RILAC のための新しい 18-GHz ECR イ オ ン 源 の 導 入”, Proceedings of the
11th Annual Meeting of Particle Accelerator Society ofJapan, p. 544–547 (2014).
小高康照, 石川盛, 小林清志, 小山亮, 柴田順翔, 月居憲俊,
仲村武志, 西田稔, 西村誠, 濱仲誠, 福沢聖児, 矢冨一慎,
坂本成彦, 内山暁仁, 奥野広樹, 影山正, 加瀬昌之,
上垣外修一, 熊谷桂子, 込山美咲, 須田健嗣, 中川孝秀,
長瀬誠, 長友傑, 福西暢尚, 藤巻正樹, 真家武士, 山田一成,
渡邉環, 渡邉裕, 山家捷一, 大城幸光: “理研 AVF サイクロ
トロン運転の現状報告”, Proceedings of the 11th Annual
Meeting of Particle Accelerator Society of Japan, p.
364–368 (2014).
福沢聖児, 濱仲誠, 石川盛, 小高康照, 小林清志, 小山亮,
仲村武志, 西田稔, 西村誠, 柴田順翔, 月居憲俊, 矢冨一慎,
須田健嗣, 段塚知志, 藤巻正樹, 福西暢尚, 藤縄雅,長谷部裕雄, 日暮祥英, 池沢英二, 今尾浩士, 加瀬昌之,
影山正, 上垣外修一, 木寺正憲, 熊谷桂子, 久保木浩功,
込山美咲, 真家武士, 長瀬誠, 中川孝秀, 中村仁音,
大西純一, 奥野広樹, 大関和貴, 坂本成彦, 内山暁仁,
渡邉環, 渡邉裕, 渡部秀, 山田一成, 山澤秀行: “理研 RIBF
におけるリングサイクロトロンの運転報告”, Proceedingsof the 11th Annual Meeting of Particle Accelerator
Society of Japan, p. 401–405 (2014).
山口由高, 若杉昌徳, 阿部康志, 洲嵜ふみ, 藤縄雅, 加瀬昌之,
込山美咲, 熊谷桂子, 眞家武士, 長江大輔, 大西純一,
小沢顕, 上坂友洋, 渡邉裕, 山口貴之, 山澤秀行, 柳澤善行,
銭廣十三, 矢野安重: “理 研 RIBF に お け る 稀 少 RI リ
ン グ の 現 状”, Proceedings of the 11th Annual Meetingof Particle Accelerator Society of Japan, p. 1381–1385(2014).
山田一成, 須田健嗣, 坂本成彦, 奥野広樹, 上垣外修一:“RIBF 大 強 度 化 計 画 用 重 イ オ ン 超 伝 導 線 形 加 速 器の 概 念 設 計”, Proceedings of the 11th Annual Meetingof Particle Accelerator Society of Japan, pp. 457–462(2014).
渡邉環, 福西暢尚, 加瀬昌之, 稲森聡, 今康一: “HTc-SQUID
ビ ー ム 電 流 モ ニ タ ー の 実 用 化”, Proceedings of the1

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

11th Annual Meeting of Particle Accelerator Society ofJapan, p. 292–295 (2014).
Oral Presentations(International Conference etc.)
Fukunishi N.: “Heavy-ion Cyclotron Gymnastics and Associated Beam Dynamics Issues”, 54th ICFA Advanced
Beam Dynamics Workshop on High Intensity, High
Brightness and High Power Hadron Beams (HB2014),
Michigan State University, East Lansing, USA, Nov.
(2014).
Higurashi Y., Nakagawa T., Ohnishi J., Ozeki K.: “Emittance Measurements for RIKEN 28 GHz SC-ECRIS”,
The 21st international workshop on ECR Ion Sources(ECRIS2014), Nizhny Novgorod, Russia, Aug. (2014).
Maeyama T., Fukunishi N., Ishikawa K.L., Furuta
T., Fukasaku K., Takagi S., Noda S., Himeno R.,
and Fukuda S.: “Preliminary Result of Nanocomposite
Fricke Gel Dosimeter”, The 5th Asia Pacific Symposiumon Radiation Chemistry, Tokyo, Japan, Sep. (2014).
Okuno H.: “Experience with Stripping of Heavy Ion
Beams”, 54th ICFA Advanced Beam Dynamics Workshop on High Intensity, High Brightness and High Power
Hadron Beams (HB2014), Michigan State University,
East Lansing, USA, Nov. (2014).
Sakamoto N.: “Present Performance of the RF System
for the RIBF Accelerator Complex and their UpgradePlan”, Science with Rare Ion Beams (SCRIBE-2014),(Variable Energy Cyclotron Centre and TRIUMF), Variable Energy Cyclotron Centre, Kolkata, India, Nov.
(2014).
Uchiyama A.: “Current Status of Web Application for
RIBF Accelerator Operations”, Workshop on Accelerator Operations (WAO2014), Mainz, Germany, Oct.
(2014).
(Domestic Conference)
前山拓哉, 福西暢尚, 石川顕一, 古田琢哉, 深作和明, 高木周,野田茂穂, 姫野龍太郎, 福田茂一: “LET 依存性のないナノ
クレイ添加フリッケゲル線量計の開発”, 第 107 回日本医学物理学会学術大会, 日本医学物理学会横浜, 4 月 (2014).
前山拓哉, 福西暢尚, 石川顕一, 深作和明, 古田琢哉, 高木周,野田茂穂, 姫野龍太郎, 福田茂一: “LET に依存しない三次元線量計”, 第 15 回放射線プロセスシンポジウム, 東京, 6
月 (2014).
前山拓哉, 福西暢尚, 石川顕一, 深作和明, 福田茂一: “LET
依存性のないゲル線量計の開発”, 先端放射線化学シンポジ
ウム, 日本放射線化学会東京, 3 月 (2015).
渡邉環, 福西暢尚, 加瀬昌之, 稲森聡, 今康一: “HTc-SQUID
ビーム電流モニターの実用化”, 第 11 回日本加速器学会年会, 青森, 8 月 (2014).
渡邉環: “理研 RIBF における高温超伝導 SQUID ビーム電流モニターの実用化”, 日本物理学会第 70 回年次大会, 東京, 3 月 (2015).
（Others）
Watanabe T.: “Development of beam current monitor- 497 -

with High-Tc SQUID at RIBF”, Institute of Modern
Physics Colloquium, Lanzhou, China, (2015).
前山拓哉, 福西暢尚, 石川顕一, 深作和明, 古田琢哉, 高木周,野田茂穂, 姫野龍太郎, 福田茂一: “LET 依存性のないゲル線量計の開発”, 平成 25 年度 HIMAC 共同利用研究成果発表会, 放射線医学総合研究所千葉, 4 月 (2014).
前山拓哉: “粒子線治療計画の三次元検証ツールとしてのナノ
コンポジットゲル線量計”, 平成 26 年度第 3 回重粒子線医工学連携セミナー, 群馬大学群馬, 6 月 (2014).
前山拓哉: “粒子線治療計画の三次元検証ツールとしてのナノ
コンポジットゲル線量計”, 理化学研究所新技術説明会, 理
化学研究所, 埼玉, 6 月 (2014).
前山拓哉, 福西暢尚, 石川顕一, 深作和明, 福田茂一: “ナノコンポジットフリッケゲル線量計の組成条件の検討”, 第 3 回
3D ゲル線量計研究会, 名古屋, 11 月 (2014).
渡邉環: “理研 AVF サイクロトロンのエネルギー測定”, 第10 回 AVF 合同打合せ, 高崎, 7 月 (2014).
渡邉環: “HTc-SQUID ビーム電流計”, 日新イオン機器株式会社講演会, 京都, 11 月 (2014).

2

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONSSLOWRI Team
Publications[Journal]（Original Papers） *Subject to Peer Review
Schury P., Ito Y., Wada M., and Wollnik H.: “Wide-band
mass measurements with a multi-reflection time-of-flightmass spectrograph”, Int. J. Mass Spectrom. 359, 19–25(2014). ＊Arai F., Ito Y., Wada M., Schury P., Sonoda T., and Mita
H.: “Investigation of the ion surfing transport methodwith a circular rf carpet”, Int. J. Mass Spectrom. 362,
56–58 (2014). ＊Schury P., Wada M., Ito Y., Arai F., Naimi S., Sonoda
T., Wollnik H., Shchepunov V.A., Smorra C., and Yuan
C.: “A high-resolution multi-reflection time-of-flightmass spectrograph for precision mass measurements at
RIKEN/SLOWRI”, Inst. Meth. In Phys. Res. B 335,
39–53 (2014). ＊Hirayama Y., Mukai M., Watanabe Y., Imai N., Ishiyama
H., Jeong S., Miyatake H., Oyaizu M., Matsuo Y.,
Sonoda T., and Wada M.: “Ionization cross section measurements for autoionizing states of iridium and rhenium”, J. Phys. B: At. Mol. Opt. Phys. 47, 075201(2014). ＊Yang X., Furukawa T., Wakui T., Fujita T., Imamura
K., Mitsuya Y., Hayasaka M., Ichikawa Y., Ishibashi
Y., Shirai H., Suzuki T., Ebara Y., HatakeyamaA., Wada M., Sonoda T., Ito Y., Kobayashi T.,
Nishimura S., Kurata-Nishimura M., Kondo Y., Yoneda
K.I., Kubono S., Ohshiro Y., Ueno H., Shinozuka T.,
Shimada T., Asahi K., and Matsuo Y.: “Laser-radiofrequency double-resonance spectroscopy of 84−87 Rb isotopes trapped in superfluid helium”, Phys. Rev. A 90,
052516 (2014). ＊Takamine A., Wada M., Okada K., Sonoda T., SchuryP., Nakamura T., Yamazaki Y., Kanai Y., Kojima
T.M., Kubo T., Katayama I., Ohtani S., Wollnik H.,
and Schuessler H.A.: “The hyperfine structure constantof Neutron Halo Nucleus 11 Be+ ”, Phys. Rev. Lett. 112,
162502 (2014). ＊Okada K., Suganuma T., Furukawa T., TakayanagiT., Wada M., and Schuessler H.A.: “Cold ion-polarmolecule reactions studied with a combined Starkvelocity-filter-ion-trap apparatus”, Phys. Rev. A 87,
043427 (2013). ＊of Nuclear Physics and the Physical Society of Japan,
Hawaii, US, Oct. (2014).
Ito Y.:“A windowless gas-cell cooler-buncher at
RIKEN/SLOWRI”, 4th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society ofJapan, Hawaii, US, Oct. (2014).
Ito Y.: “MRTOF for high-precision mass measurements at
RIKEN”, 4th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan, Hawaii,
US, Oct. (2014).
Schury P.: “Towards Identification of Super Heavy Elements by Means of Mass Spectroscopy”, 4th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan, Hawaii, US, Oct. (2014).
Wada M.: “SLOWRI: a Universal Low-Energy RI-Beam
Facility at RIKEN RIBF”, 2nd Conference on Advancesin Radioactive Isotope Science (ARIS2014), Tokyo,
Japan, June (2014).
(Domestic Conference)
Tomita H., Takamatsu T., Furuta Y., Noto T., Wendt
K., Sonnenschein V., Nakamura A., Iguchi T., Kron
T., Sonoda T., and Wada M.: “Development of High
Resolution Resonance Ionization Spectroscopy for radionuclide analysis”, The 75th Japan Society of Applied
Physics, Sapporo, Japan, Sept. (2014).

Oral Presentations(International Conference etc.)
Ito Y.: “Gas-cell beam cooler-buncher for low-energy experiments at SLOWRI”, 6th international conference on
Trapped Charged Particles and Fundamental Physics(TCP2014), Takamatsu, Japan, Dec. (2014).
Arai F.: “Performance of ion surfing rf-carpets for RI beamgas catcher”, 4th Joint Meeting of the APS Division- 498 -

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Rare RI-ring Team
Oral Presentations(International Conference etc.)
Wakasugi M., and rare-RI ring collaboration: “The RareRI Ring Facility at RIKEN RI Beam Factory”, 2nd
Conference on Advances in Radioactive Isotope Science(ARIS2014), Tokyo, Japan, June (2014).
Yamaguchi Y., and rare-RI ring collaboration: “Rare-RI
Ring at RIKEN RI Beam Factory”, The sixth international conference on Trapped Charged Particles andFundamental Physics (TCP2014), Takamatsu, Japan,
Desember (2014).
Abe Y., Yamaguchi Y., Wakasugi M., Uesaka T., Ozawa
A., Suzaki F., Miura H., Yamaguchi T., and Yano Y.:“Isochronous study of the Rare-RI Ring”, 9th International Conference on Nuclear Physics at Storage Rings(STORI2014), St. Goar, Germany, September (2014).
Ozawa A.: “Mass measurement with Rare-RI Ring”, Science and Next Generation Experiments at FRIB and
RIBF, Hawaii, USA, October (2014).
Abe Y.: “Mass measurement of RI with Rare-RI Ringat RIKEN”, Post-TCP PMM Workshop, Wako, Japan,
December (2014).
Suzaki F., Zenihiro J., Ozawa A., Suzuki T., UesakaT., Wakasugi M., Yamada K., Yamaguchi T., Abe Y.,
and Yamaguchi Y.: “Performance of a resonant Schottky pick-up for Rare-RI Ring project”, 2nd Conference
on Advances in Radioactive Isotope Science (ARIS2014),
Tokyo, Japan, June (2014).
Yamaguchi Y., Miura H., Wakasugi M., Abe Y., Ozawa
A., Suzaki F., Tokuchi A., Uesaka T., Yamaguchi T.,
and Yano Y.: “Fast-kicker system for Rare-RI Ring”,
9th International Conference on Nuclear Physics at Storage Rings (STORI2014), St. Goar, Germany, September(2014).
Suzaki F., Zenihiro J., Ozawa A., Suzuki T., UesakaT., Wakasugi M., Yamada K., Yamaguchi T., Abe Y.,
and Yamaguchi Y.: “A resonant Schottky pick-up for
Rare-RI Ring at RIKEN”, 9th International Conferenceon Nuclear Physics at Storage Rings (STORI2014), St.
Goar, Germany, September (2014).
(Domestic Conference)洲嵜ふみ, 阿部康志, NaimiSarah, 三浦宙, 小沢顕, 鈴木健,
上坂友洋, 若杉昌徳, 山田一成, 山口貴之, 山口由高, 銭廣十三, ChenXiangcheng: “稀少 RI リングの共鳴ショット
キーピックアップのオフライン性能試験”, 日本物理学会
第 70 回年次大会, (日本物理学会), 東京, 3 月 (2015).
三浦 宙, 山口 由高, 若杉 昌徳, 阿部 康志, 小沢 顕, 洲嵜 ふみ,
徳地明, 上坂友洋, 山口貴之, 長江大輔, 柳澤善行, 鈴木健:
“稀少 RI リングのためのキッカーマグネットの開発”, 日
本物理学会 第 70 回年次大会, (日本物理学会), 東京, 3 月(2015).
山口由高, 若杉昌徳, 阿部康志, 洲嵜ふみ, 藤縄雅, 加瀬昌之,
込山美咲, 熊谷桂子, 眞家武士, 長江大輔, 大西純一, 小沢- 499 -顕, 上坂 友洋, 山口 貴之, 山澤 秀行, 柳澤 善行, 銭廣 十三,
矢野安重: “理研 RIBF における稀少 RI リングの現状”, 第11 回日本加速器学会年会, (日本加速器学会), 青森市, 8 月(2014).

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

シティモニタ”, 第 70 回日本物理学会年次大会, (日本物理学会), 新宿, 日本, 3 月 (2015).

SCRIT Team
Oral Presentations(International Conference etc.)
Wakasugi M., and SCRIT collaboration : “The SCRIT
electron scattering facility at the RIKEN RI Beam Factory”, 5th EURISOL Topical Meeting, (York University), York, UK, Jul. (2014).
Suda T. : “SCRIT Electron Scattering Facility”, 59th
Annual Conference of the SA Institute of Physics,(South African Institute of Physics), Johannesburg,
South Africa, Jul. (2014).
Ohnishi T., and SCRIT collaboration : “The SCRIT electron scattering facility project at RIKEN RI Beam Factory”, 9th International conference on Nuclear Physics
at Storage Rings (STORI14), (GSI Helmholtz Centre for
Heavy Ion Research), St Goar, Germany, Oct. (2014).
Wakasugi M., and SCRIT collaboration : “The SCRIT
electron scattering facility”, 6th Trapped Charged Particleand Fundamental Physics, (RIKEN), Takamatsu, Kagawa, Japan, Dec. (2014).
Suda T. : “Electron Scattering for Exotic Nuclei”, 38th
Symposium on Nuclear Physics, (Universidad Nacional
Autónoma de México), Cocoyoc, Mexico, Jan. (2015).
(Domestic Conference)
榎園昭智, 市川進一, 大西哲哉, 栗田和好, 須田利美, 玉江忠明,
塚田暁, 水流輝明, 戸ヶ崎衛, 原雅弘, 原口祐司, 堀利匡, 松尾
咲希, 米山俊平, 若杉昌徳,WANG Shou : “Development of
the electron spectrometer for the SCRIT experiment”,
4th Joint Meeting of the Nuclear Physics Divisions of
the American Physics Society and the Physical Societyof Japan , (日本物理学会, アメリカ物理学会), Hawaii,
USA, 10 月 (2014).
塚 田 暁, 宮 本 嵩 也, 須 田 利 美, 玉 江 忠 明, 水 流 輝 明, 米 山
俊 平 , 原 雅 弘, 市 川 進 一 , 大 西 哲 哉 , 若 杉 昌 徳 , 榎 園 昭 智 ,栗 田 和 好, 松 尾 咲 希, 戸 ケ 崎 衛, 原 口 祐 司,Wang Shuo :“SCRIT electron scattering facility”, 4th Joint Meetingof the Nuclear Physics Divisions of the American Physics
Society and the Physical Society of Japan , (日本物理学会, アメリカ物理学会), Hawaii, USA, 10 月 (2014).
松尾咲希, 市川進一, 榎園昭智, 大西哲哉, 栗田和好, 須田利美,
玉江忠明, 塚田暁, 水流輝明, 戸ヶ崎衛, 原雅弘, 原口祐司,
堀利匡, 米山俊平, 若杉昌徳,WANG Shou : “Developmentof the scattererd electron spectrometer for the SCRIT
experiment”, 第 70 回日本物理学会年次大会, (日本物理学会), 新宿, 日本, 3 月 (2015).
塚田暁, 須田利美, 玉江忠明, 水流輝明, 米山俊平, 松田一衛,
森谷洋祐, 原雅弘, 市川進一, 大西哲哉, 若杉昌徳, 榎園昭智,
栗田和好, 松尾咲希, 戸ケ崎衛, 堀利匡 : “SCRIT 電子スペ
クトロメータの運動量分解能とアクセプタンス評価”, 第70 回日本物理学会年次大会, (日本物理学会), 新宿, 日本, 3
月 (2015).
米山俊平, 須田利美, 玉江忠明, 塚田暁, 水流輝明, 松田一衛,
森谷洋祐, 大西哲哉, 若杉昌徳, 榎園昭智, 栗田和好, 戸ヶ崎衛, 松尾咲希 : “制動輻射を利用した SCRIT 実験用ルミノ- 500 -

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

BigRIPS Team
Publications[Journal]（Original Papers） *Subject to Peer Review
Watanabe H., Lorusso G., Nishimura S., Otsuka T.,
Ogawa K., Xu Z.Y., Sumikama T., Söderström P.-A.,
Doornenbal P., Li Z., Browne F., Gey G. Jung H. S..
Taprogge J., Vajta Zs., Wu J., Yagi A., Baba H., BenzoniG., Chae K. Y.. Crespi F.C. L., Fukuda N., Gernhäuser
R., Inabe N., Isobe T., Jungclaus A., Kameda D.,
Kim J. D., Kim Y. K., Kojouharov I., Kondev F. G.,
Kubo T., Kurz N., Kwon Y. K., Lane G. J., Moon C.B., Montaner-Pizá A., Moschner K., Naqvi F., Niikura
M., Nishibata H., Nishimura D., Odahara A., OrlandiR., Patel Z., Podolyák Zs., Sakurai H., Schaﬀner H.,
Simpson G. S., Steiger K., Suzuki H., Takeda H., Wendt
A., and Yoshinaga K.: “Monopole-Driven Shell Evolution below the Doubly Magic Nucleus 132 Sn Exploredwith the Long-Lived Isomer in 126 Pd”, Phys. Rev. Lett.
113, 042502 (2014). ＊Taprogge J., Jungclaus A., Grawe H., Nishimura3 S.,
Doornenbal P., Lorusso G., Simpson G. S., Söderström
P.-A., Sumikama T., Xu Z. Y., Baba H., Browne F.,
Fukuda N., Gernhäuser R., Gey G., Inabe N., IsobeT., Jung H. S., Kameda D., Kim G. D., Kim Y.-K.,
Kojouharov I., Kubo T., Kurz N., Kwon Y. K., Li Z.,
Sakurai H., Schaﬀner H., Steiger K., Suzuki H., Takeda
H., Vajta Zs., Watanabe H., Wu J., Yagi A., Yoshinaga
K., Benzoni G., Bönig S., Chae K. Y., Coraggio L.,
Covello A., Daugas J.-M., Drouet F., Gadea A., Gargano
A., Ilieva S., Kondev F. G., Kröll T., Lane G. J.,
Montaner-Pizá A., Moschner K., Mücher D., Naqvi F.,
Niikura M., Nishibata H., Odahara A., Orlandi R., PatelZ., Podolyák Zs., and Wendt A.: “1p3/2 Proton-HoleState in 132 Sn and the Shell Structure Along N = 82”,
Phys. Rev. Lett. 112, 132501 (2014). ＊Taprogge J., Jungclaus A., Grawed H., Nishimura S., Xu
Z.Y., Doornenbal P., Lorusso G., Nácher E., Simpson G.
S., Söderström P.-A., Sumikama T., Baba H., BrowneF., Fukuda N., Gernhäuser R., Gey G., Inabe N., IsobeT., Jung H. S., Kameda D., Kim G. D., Kim Y.-K.,
Kojouharov I., Kubo T., Kurz N., Kwon Y. K., Li Z.,
Sakurai H., Schaﬀner H., Steiger K., Suzuki H., Takeda
H., Vajta Zs., Watanabe H., Wu J., Yagi A., Yoshinaga
K., Benzoni G., Bönig S., Chae K. Y., Coraggio L.,
Covello A., Daugas J.-M., Drouet F., Gadea A., Gargano
A., Ilieva S., Kondev F. G., Kröll T., Lane G. J.,
Montaner-Pizá A., Moschner K., Mücher D., Naqvi F.,
Niikura M., Nishibata H., Odahara A., Orlandi R., PatelZ., Podolyák Zs., and Wendt A.: “Identiﬁcation of a millisecond isomeric state in 129 Cd81 via the detection of internal conversion and Compton electrons”, Phys. Lett.
B 738, 223–227 (2014). ＊Simpson G. S., Gey G., Jungclaus A., Taprogge J.,

Nishimura S., Sieja K., Doornenbal P., Lorusso G.,
Söderström P.-A., Sumikama T., Xu Z. Y., Baba H.,
Browne F., Fukuda N., Inabe N., Isobe T., Jung H.
S., Kameda D., Kim G. D., Kim Y.-K., Kojouharov
I., Kubo T., Kurz N., Kwon Y. K., Li Z., Sakurai
H., Schaﬀner H., Shimizu Y., Suzuki H., Takeda H.,
Vajta Z., Watanabe H., Wu J., Yagi A., Yoshinaga K.,
Bönig S., Daugas J.-M., Drouet F., Gernhäuser R., Ilieva
S., Kröll T., Montaner-Pizá A., Moschner K., Mücher
D., Naı̈dja H., Nishibata H., Nowacki F., Odahara A.,
Orlandi R., Steiger K., and Wendt A.: “Yrast 6+ Seniority Isomers of 136,138 Sn”, Phys. Rev. Lett. 113,132502 (2014). ＊Kobayashi N., Nakamura T., Kondo Y., Tostevin J. A.,
Utsuno Y., Aoi N., Baba H., Barthelemy R., Famiano
M. A., Fukuda N., Inabe N., Ishihara M., Kanungo R .,Kim S., Kubo T., Lee G. S., Lee H. S., Matsushita M.,
Motobayashi T., Ohnishi T., Orr N. A., Otsu H., OtsukaT., Sako T., Sakurai H., Satou Y., Sumikama T., Takeda
H., Takeuchi S., Tanaka R., Togano Y., and Yoneda K.:“Observation of a p-Wave One-Neutron Halo Conﬁguration in 37 Mg”, Phys. Rev. Lett. 112, 242501 (2014).
＊
Nakamura T., Kobayashi N., Kondo Y., Satou Y., Tostevin
J. A., Utsuno Y., Aoi N., Baba H., Fukuda N., Gibelin
J., Inabe N., Ishihara M., Kameda D., Kubo T.,
Motobayashi T., Ohnishi T., Orr N. A., Otsu H., OtsukaT., Sakurai H., Sumikama T., Takeda H., TakeshitaE., Takechi M., Takeuchi S., Togano Y., and Yoneda
K.: “Monopole-Driven Shell Evolution below the Doubly Magic Nucleus 132 Sn Explored with the Long-Lived
Isomer in 126 Pd”, Phys. Rev. Lett. 113, 042502 (2014).
＊
Ozawa A., Moriguchi T., Ohtsubo T., Aoi N., Fang D. Q.,
Fukuda N., Fukuda M., Geissel H., Hachiuma I., InabeN., Ishibashi Y., Ishimoto S., Ito Y., Izumikawa T.,
Kameda D., Kubo T., Kuboki T., Kusaka K., Lantz M.,
Ma Y. G., Mihara M., Miyashita Y., Momota S., Nagae
D., Namihira K., Nishimura D., Ooishi H., Ohkuma
Y., Ohnishi T., Ohtake M., Ogawa K., Shimbara Y.,
Suda T., Sumikama T., Suzuki H., Suzuki S., SuzukiT., Takechi M., Takeda H., Tanaka K., Watanabe R.,
Winkler M., Yamaguchi T., Yanagisawa Y., Yasuda Y.,
Yoshinaga K., Yoshida A., and Yoshida K.: “Chargechanging cross sections of 30 Ne, 32,33 Na with a proton
target”, Phys. Rev. C 89, 044602 (2014). ＊Oral Presentations(International Conference etc.)
Fukuda N., Kameda D., Takeda H., Suzuki H., Ahn D.
S., Shimizu Y., Inabe N., and Kubo T.: “Performanceof the Fragment Separator BigRIPS and Perspectives on
In-ﬂight RI Beam Production”, Advances in Radioactive
Isotope Science (ARIS2014), (RIKEN and University ofTokyo), Tokyo, Japan, June (2014).

- 501 -

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONSSato Y., Fukuda N., Takeda H., Kameda D., Suzuki H.,
Shimizu Y., Ahn D.S., Murai D., Inabe N., Shimaoka
T., Tsubota M., Kaneko J., Chayahara A., Umezawa
H., Shikata S., Kumagai H., Murakami H., Yoshida K.,
Kubo T.: “Status of Beam Line Detectors for the BigRIPS Fragment Separator at RIKEN RI Beam Factory:
Issues on High Rates and Resolution”, The 2nd Conference on ”Advances in Radioactive Isotope Science 2014”(ARIS 2014), (RIKEN and University of Tokyo), Tokyo,
Japan, June (2014).
Fukuda N., Kameda D., Takeda H., Suzuki H., Ahn D.
S., Shimizu Y., Murai D., Inabe N., and Kubo T. “Production of rare isotopes at RIKEN RI Beam Factory:summary of search for neutron-rich new isotopes”, Forthjoint meeting of the nuclear physics divisions of theAmerican Physical Society and the Physical Society ofJapan, ( American Physical Society and the PhysicalSociety of Japan ), Hawaii, USA, Oct. (2014).
Shimizu Y., Kubo T., Fukuda N., Ahn D. S., Inabe N.,
Kameda D., Sato H., Suzuki H., Takeda H., Yoshida K.,
and EURICA collaboration: “Identiﬁcation of 25 newneutron-rich isotopes produced in the EURICA uranium
beam campaign at RIKEN RIBF”, 4th Joint Meetingof the APS Division of Nuclear Physics and the Physical Society of Japan, ( American Physical Society and
the Physical Society of Japan ), Hawaii, USA, October(2014).
Kameda D., Kubo T., and the BigRIPS new isotope
collaboration: “Observation of new K isomers among
neutron-rich rare earth nuclei produced by in-ﬂight ﬁssion of 345 MeV/nucleon 238 U”, Forth joint meeting of
the nuclear physics divisions of the American PhysicalSociety and the Physical Society of Japan, ( American
Physical Society and the Physical Society of Japan ),Hawaii, USA, Oct. (2014).
Murai D. Ieki K., Kubo T., Inabe N., Kameda D.,
Fukuda N., Takeda H., Suzuki H., Yoshida K.,
and BigRIPS collabration: “Measurement of production
yield for neutron-rich nuclei around Z=60 from in-ﬂight
ﬁssion of a 238 U beam at 345 MeV/nucleon”, Forth joint
meeting of the nuclear physics divisions of the American
Physical Society and the Physical Society of Japan, (The American Physical Society and the Physical Society of Japan ), Hawaii, USA, Oct.
Suzuki H., Kubo T., Fukuda N., Inabe N., Kameda D.,
Takeda H., Sato H., Shimizu Y., Ahn D. S., Ohkoda Y.,
Iwasa N., Murai D., and BigRIPS collaboration: “Production cross section of radioactive isotopes produced
from a 124 Xe beam at 345 MeV/u by the BigRIPS separator at RIKEN RI Beam Factory”, Forth joint meetingof the nuclear physics divisions of the American PhysicalSociety and the Physical Society of Japan, ( The American Physical Society and the Physical Society of Japan), Hawaii, USA, Oct. (2014).
(Domestic Conference)- 502 -

木佐森慶一, 下浦享, 李清秀, 井手口栄治, 稲辺尚人,
伊藤正俊, 上坂友洋, 大田晋輔, 亀田大輔, 川畑貴裕,
川瀬頌一郎, 菊地陽介, 久保敏幸, 久保田悠樹, 郷慎太郎,
小林幹, 近藤洋介, 坂口聡志, 酒井英行, 笹本良子,
笹野匡紀, 佐藤広海, 清水陽平, 鈴木宏, 高木基伸, 民井淳,
竹田浩之, 武内聡, 津村美保, 時枝紘史, 西隆博, 西村美月,
野地俊平, 馬場秀忠, 馬場辰彦, 堂園昌伯, 福田直樹,
藤井俊彦, 前田幸重, 松原礼明, 三木謙二郎, 道正新一郎,
宮裕之, 柳沢善行, 矢向謙太郎, 横山輪, 吉田光一,
M. Assie, D. Beaumel, F. Hammache, A. Stolz: “発熱型
二重荷電交換反応 4 He(8 He,8 Be)4n による 4 中性子系の研究”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京, 3
月 (2015).
小山俊平, 大津秀暁, 清水陽平, 米田健一郎, 佐藤広海,
本林透, 西村美月, 銭廣十三, 櫻井博儀, 武内聡, 磯部忠昭,
馬場秀忠, 日下健祐, 大西純一, 笹野匡紀, P. Doornenbal,
福田直樹, 小林俊雄, 炭竈聡之, 松田洋平, 佐藤義輝,
J. Hwang, 近藤洋介, 中村隆司, 栂野泰宏, 南方亮吾,
生越駿, 村上哲也, 中塚徳継, J. Gibelin, L. Sylvain,
新倉潤, 小林信之, H. Liu, J. Lee, E. Nikolskii, 坂口聡志,
D. Beaumel: “16 C クラスター準位探索実験”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京, 3 月 (2015).
齊藤敦美, 近藤洋介, 中村隆司, Nadia Lynda Achouri,
馬場秀忠,
Franck Delaunay,
Thomas Aumann,
福田直樹,
Julien Gibelin,
Pieter Doornenbal,
Jongwon Huang,
稲辺尚人,
磯部忠昭,
亀田大輔,
簡野大輝, Sunji Kim, 小林信之, 小林俊雄, 久保敏幸,
Sylvain Leblond,
Jenny Lee,
Miguel Marques,
南方亮吾, 本林透, 村井大地, 村上哲也, 武藤琴美,
中嶋丈嘉, 中塚徳継, Alahari Navin, 西征爾郎, 生越駿,
Nigel Andrew Orr, 大津秀暁, 佐藤広海, 佐藤義輝,
清水陽平, 鈴木宏, 高橋賢人, 竹田浩之, 武内聡, 田中隆己,
栂野泰宏,
Adam Garry Tuﬀ
Marine Vandebrouck,
米田健一郎: “中性子過剰 19 B の相互作用断面積”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京, 3 月 (2015).
栂野泰宏, 南方亮吾, 生越駿, 中村隆司, 磯部忠昭, 稲辺尚人,
大津秀暁, 亀田大輔, 簡野大輝, 久保敏幸, 小林俊雄,
小林信之, 近藤洋介, 佐藤広海, 佐藤義輝, 清水陽平,
鈴木宏, 高橋賢人, 武内聡, 竹田浩之, 田中隆己, 中嶋丈嘉,
中塚徳継, 西征爾郎, 福田直樹, 馬場秀忠, 武藤琴美,
村井大地, 村上哲也, 本林透, 米田健一郎, N. L. Achouri,
A. G. Tuﬀ, T. Aumann, F. Delaunay, J. Gibelin,
J. Hwangy, S. Kim, J. Lee, M. Marques, A.Navin,
N. A. Orr, P. Doornenbal, S. Leblond, M. Vandebrouck:“19,20,22 C の反応断面積”, 日本物理学会第 70 回年次大会,(早稲田大学), 東京, 3 月 (2015).

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SAMURAI Team
Publications[Journal]（Original Papers） *Subject to Peer Review
N. Kobayashi, T. Nakamura, Y. Kondo, J. A. Tostevin,Y. Utsuno, N. Aoi, H. Baba, R. Barthelemy, M. A. Famiano, N. Fukuda, N. Inabe, M. Ishihara, R. Kanungo,
S. Kim, T. Kubo, G. S. Lee, H. S. Lee, M. Matsushita, T. Motobayashi, T. Ohnishi, N. A. Orr,
H. Otsu, T. Otsuka, T. Sako, H. Sakurai, Y. Satou,
T. Sumikama, H. Takeda, S. Takeuchi, R. Tanaka,
Y. Togano, K. Yoneda.:“Observation of a p-Wave One-Neutron Halo Conﬁguration in 37 Mg”, Phys.Rev.Lett. 112, 242501 (2014).
S. Michimasa, Y. Yanagisawa, K. Inafuku, N. Aoi,
Z. Elekes, Zs. Fulop, Y. Ichikawa, N. Iwasa, K. Kurita,
M. Kurokawa, T. Machida, T. Motobayashi, T. Nakamura, T. Nakabayashi, M. Notani, H. J. Ong, T. K. Onishi, H. Otsu, H. Sakurai, M. Shinohara, T. Sumikama,
S. Takeuchi, K. Tanaka, Y. Togano, K. Yamada, M. Yamaguchi, K. Yoneda.:“Quadrupole collectivity in island-of-inversion nuclei
28,30
Ne and 34,36 Mg”, Phys.Rev. C 89, 054307 (2014).
T. Nakamura, N. Kobayashi, Y. Kondo, Y. Satou,
J. A. Tostevin, Y. Utsuno, N. Aoi, H. Baba, N. Fukuda,
J. Gibelin, N. Inabe, M. Ishihara, D. Kameda, T. Kubo,
T. Motobayashi, T. Ohnishi, N. A. Orr, H. Otsu,
T. Otsuka, H. Sakurai, T. Sumikama, H. Takeda,
E. Takeshita, M. Takechi, S. Takeuchi, Y. Togano,
K. Yoneda.:“Deformation-Driven p-Wave Halos at the Drip Line:
31Ne”, Phys.Rev.Lett. 112, 142501 (2014).
A. Obertelli, A. Delbart, S. Anvar, L. Audirac, G. Authelet, H. Baba, B. Bruyneel, D. Calvet, F. Chateau,
A. Corsi, P. Doornenbal, J.-M. Gheller, A. Giganon,
C. Lahonde-Hamdoun, D. Leboeuf, D. Loiseau, A. Mohamed, J.-Ph. Mols, H. Otsu, C. Peron, A. Peyaud,
E. C. Pollacco, G. Prono, J.-Y. Rousse, C. Santamaria,
T. Uesaka.:“MINOS: A vertex tracker coupled to a thick liquidhydrogen target for in-beam spectroscopy of exotic nuclei”, Eur.Phys.J. A 50, 8 (2014).
Y. Satou, J.W. Hwang, S. Kim, K. Tshoo, S. Choi,
T. Nakamura, Y. Kondo, N. Matsui, Y. Hashimoto,
T. Nakabayashi, T. Okumura, M. Shinohara, N. Fukuda,
T. Sugimoto, H. Otsu, Y. Togano, T. Motobayashi,
H. Sakurai, Y. Yanagisawa, N. Aoi, S. Takeuchi,
T. Gomi, M. Ishihara, S. Kawai, H. J. Ong, T. K. Onishi, S. Shimoura, M. Tamaki, T. Kobayashi, Y. Matsuda, N. Endo, M. Kitayama.:“One-neutron knockout reaction of 17 C on a hydrogentarget at 70 MeV/nucleon”, Phys. Lett. B 728, 462(2014).
K. Tshoo, Y. Satou, C. A. Bertulani, H. Bhang, S. Choi,

T. Nakamura, Y. Kondo, S. Deguchi, Y. Kawada,
Y. Nakayama, K. N. Tanaka, N. Tanaka, Y. Togano,
N. Kobayashi, N. Aoi, M. Ishihara, T. Motobayashi,
H. Otsu, H. Sakurai, S. Takeuchi, K. Yoneda, F. Delaunay, J. Gibelin, F. M. Marques, N. A. Orr,
T. Honda, T. Kobayashi, T. Sumikama, Y. Miyashita,
K. Yoshinaga, M. Matsushita, S. Shimoura, D. Sohler,
J. W. Hwang, T. Zheng, Z. H. Li, Z. X. Cao.:“Neutron occupancy of the 0d5/2 orbital and the N=16
shell closure in 24 O”, Phys.Lett. B 739, 19 (2014).
R. Shane, A.B. McIntosh, T. Isobe, W.G. Lynch, H. Baba,
J. Barney, Z. Chajecki, M. Chartier, J. Estee, M. Famiano, B. Hong, K. Ieki, G. Jhang, R. Lemmon, F. Lu,
T. Murakami, N. Nakatsuka, M. Nishimura, R. Olsen,
W. Powell, H. Sakurai, A. Taketani, S. Tangwancharoen, M.B. Tsang, T. Usukura, R. Wang,S.J. Yennello, J. Yurkona.:“SπRIT: A time-projection chamber for symmetryenergy studies”, Nuclear Instruments and Methods inPhysics Research A 784 (2015) 513–517.
[Book · Proceedings]（Original Papers）
K. Tshoo, Y. Satou, H. Bhang, S. Choi, T. Nakamura,
Y. Kondo, S. Deguchi, Y. Kawada, N. Kobayashi,
Y. Nakayama, K. N. Tanaka, N. Tanaka, Y. Togano,
N. Aoi, M. Ishihara, T. Motobayashi, H. Otsu, H. Sakurai, S. Takeuchi, K. Yoneda, F. Delaunay, J. Gibelin,
F. M. Marques, N. A. Orr, T. Honda, M. Matsushita,
T. Kobayashi, Y. Miyashita, T. Sumikama, K. Yoshinaga, S. Shimoura, D. Sohler, T. Zheng, Z. X. Cao,Z. H. Li.:
“Neutron occupancy of 0d5/2 orbital in 24 O”,
Int.Nuclear Physics Conf. 2013, (IUPAP), Firenze,
Italy, June 2-7, 2013, S.Lunardi, P.G.Bizzeti,
W.S.Kabana, C.Bucci, et al.Eds.p.02103 (2014);
EPJ web of Conf.v.66, (2014).
Oral Presentations(International Conference, etc.)
Y. Kondo.: “Experimental study of neutron-rich nuclei
near and beyond drip line with SAMURAI at RIBF”,
3rd International Workshop on “State of the Art in Nuclear Cluster Physics”(SOTANCP3), KGU Kannai Media Center, Kanto Gakuin University, Yokohama, Japan.
May 26-30, 2014.
Y. Kondo.: “Invariant-mass spectroscopy of extremely
neutron-rich nuclei with SAMURAI at RIBF”, Advancesin Radioactive Isotope Science (ARIS2014), ITO International Research Center, University of Tokyo, Japan,
June 1-6, 2014
T. Nakamura.: “Weakly bound and unbound few-bodynucleonic systems”, Workshop“ Few-body universality
in atomic and nuclear physics: Recent Experimental andTheoretical Advances, INT, University of Washington,
Seattle, USA, May 12–16, 2014.

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Ⅶ. LIST OF PUBLICATIONS

H. Otsu.: “SAMURAI at RIBF”, Workshop on the HighRigidity Spectrometer for FRIB, (Michigan State University), East Lansing, July (2014).
T. Nakamura.: “Coulomb and nuclear breakup of exotic
nuclei near the neutron drip line”. ECT* Workshop“Breakup Reactions of Exotic Nuclei and Related Topics”, ECT*, Trento, Italy , July 16–18, 2014,
Y. Kondo.: “Experimental studies related to di-neutron
correlations”, One-day intensive workshop on “dineutron and alpha-cluster correlations in exotic nuclei”,
RIKEN, Japan. July 10, 2014.
T. Nakamura.: “Island of Inversion Studied by Coulomb
and Nuclear Breakup”, PKU-CUSTIPEN Nuclear Reaction Workshop, “ Reactions and Spectroscopy of Unstable Nuclei ” , Peking Univ., Beijing, China, 10–14,
Aug. (2014).
Y. Kondo.: “Recent experimental results on unbound oxygen isotopes beyond the drip line”, PKU-CUSTIPEN
Nuclear Reaction Workshop ”Reactions and Spectroscopy of Unstable Nuclei”, Peking University, Beijing,
China, August 10-14, 2014.
T. Nakamura.: “Nuclear Structure near and beyond theneutron drip line probed by breakup reactions”, Int.
Symposium on Physics of Unstable Nuclei, Ho Chi Minh
City, Vietnam, 3–8, Nov. (2014).
T. Nakamura.: “Study of nuclei near and beyond the neutron drip line at SAMURAI at RIBF”, International
Workshop on “Critical Stability in Few-body Systems”,
RIKEN, Wako, 26-30, Jan. (2015).
V. Panin for the HI-p collaboration.: “Investigation of
proton-unbound states in neutron-deﬁcient isotopes relevant to the astrophysical rp-process”, SAMURAI International Collaboration Workshop 2014, (Tohoku University), Sendai, Sep. (2014).
Y. Kondo, T. Nakamura, N. L. Achouri, T. Aumann, H. Baba, F. Delaunay, P. Doornenbal, N. Fukuda, J. Gibelin, J. Hwang, N. Inabe, T. Isobe, D. Kameda, D. Kanno, S. Kim,
N. Kobayashi,T. Kobayashi,T. Kubo,S. Leblond,J. Lee, F. M. Marques, R. Minakata, T. Motobayashi,
T. Murakami, K. Muto, T. Nakashima, N. Nakatsuka,
A. Navin, S. Nishi, S. Ogoshi, N. A. Orr, H. Otsu,
H. Sato,Y. Satou,Y. Shimizu, H. Suzuki, K. Takahashi, H. Takeda, S. Takeuchi, R. Tanaka, Y. Togano,A. G. Tuﬀ, M. Vandebrouck, K. Yoneda.:“Experimental study of 25 O and 26 O by using SAMURAI at RIBF”, 4th Joint Meeting of the APS Divisionof Nuclear Physics and the Physical Society of Japan,
Waikokoa, Hawaii, USA, Oct. 7-11 (2014).
Y. Togano for SAMURAI collaboration, “Reaction crosssection of 22 C”, 4th Joint Meeting of the APS Divisionof Nuclear Physics and the Physical Society of Japan,
Waikokoa, Hawaii, USA, Oct. 7-11 (2014).
M. Shikata, T. Nakamura, Y. Togano, Y. Kondo.: “Development of the new gamma–ray calorimeter for themeasurement of Pigmy Dipole Resonance”, 4th Joint
Meeting of the APS Division of Nuclear Physics andthe Physical Society of Japan, Waikokoa, Hawaii, USA,
Oct. 7-11 (2014).
J. Tsubota.: “Simulation of two neutron detection for invariant mass spectroscopy of unstable nuclei”, 4th Joint
Meeting of the APS Division of Nuclear Physics and the
Physical Society of Japan, Waikokoa, Hawaii, USA, Oct.
7-11 (2014).
Y. Kubota.: “Probing multi-neutron correlation via
knockout reaction”, Critical Stability in Few-Body Systems, Saitama, Japan, January 26–30, 2015.
T. Nakamura: “Nuclear Matter in Neutron Stars by Experimental and Astronomical Observations” Hadrons
and Hadron Interactions in QCD 2015 (symposium),
YITP, Kyoto University, 2–6, March (2015).
(Domestic Conference)栂野泰宏, “中性子過剰核の電気双極子応答を用いた対称エネ
ルギーの研究”, 実験と観測で解き明かす中性子星の核物質
第 3 回研究会, 静岡県熱川ハイツ, 2015 年 8 月.
栂野泰宏, “中性子過剰核の電気双極子応答と核物質の状態方程式”, 宇宙核物理実験の現状と将来, 大阪大学 RCNP,
2014 年 8 月.
近藤洋介: “中性子ドリップライン近傍核における２中性子相関”, RCNP 研究会 “QCD を基礎とする核子多体系物理の理解”, (大阪大学 RCNP), 大阪 12 月 (2014)
小山俊平, 大津秀暁, 清水陽平, 米田健一郎, 佐藤広海, 本林透, 西村美月, 銭廣十三, 櫻井博儀, 武内 聡, 磯部忠昭, 馬場秀忠, 日下健祐, 大西純一, 笹野匡紀, Doornenbal P., 福田直樹, 小林俊雄, 炭竈聡之, 松田洋平, 佐藤義輝, Hwang
J., 近藤洋介, 中村隆司, 栂野泰宏, 南方亮吾, 生越駿, 村上
哲也, 中塚徳継, Gibelin J., Sylvain L., 新倉潤, 小林信之,
Liu H., Lee J., Nikolskii E., 坂口聡志, Beaumel D.:“16 C クラスター準位探索実験”, 日本物理学会 70 年次大会, (早稲田大学), 東京, 3 月 (2015).
宮崎卓也, 大津秀暁, Nikolskii E.Y., 志賀慶明, 西村美月,
武 内 聡, 佐 藤 義 輝, 黒 川 明 子, 馬 場 秀 忠, Lorusso G.,
磯部忠昭, 新倉 潤, Kuzmin E.A., Korsheninnikov A.A.,
Ogloblin A.A., Krupko S.A., Golovkov M.S., Bezbakh
A.A, Slepnev R.S., Fomichev A.S., Sidorchuk S.I., Gorshkov A.V., Knyazev A.G., Papka P., JinØ.H., Kim S.
Hwang J., Choi S., Chae H., Kim E., Kim Y., Lubos
D., Beaumel D., Soederstroem P.A., 坂口 聡志, 久保野茂, Perrevoort A.K., Milman E., Chebotaryov S., PowellW., 本林透, 米田健一郎, 櫻井博儀.:“欠損質量核分光による陽子ドリップライン炭素原子核の構造研究”, 日本物理学会第 70 回年次大会, (早稲田大学),
東京, 3 月 (2015).
V. Panin and K. Yoneda for the HI-p collaboration.: “Investigation of key nuclear reactions in the astrophysicalrp-process using SAMURAI”, 日本物理学会第 70 回年次
大会, (早稲田大学), 東京, 3 月 (2015).
Stuhl L., Krasznahorkay A., Csatlós A., Algora A., GulyásJ., Kalinka G., Timár J., Kalantar-Nayestanaki N.,
Rigollet C., Bagchi S., Najaﬁ M.A., Sasano M., Yasuda- 504 -

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J.: “Neutron spectrometer for studying giant resonanceswith (p,n) reactions in inverse kinematics”, 日本物理学会第 70 会年次大会, (早稲田大学), 東京, 3 月 (2015).
久 保 田 悠 樹, Corsi A., 笹 野 匡 紀, 上 坂 友 洋, Obertelli A.,
Santamaria C., Pollacco E. C., 銭廣十三, 堂園昌伯, 大田
晋輔, 時枝紘史, 川瀬頌一郎, Tang T. L., 高木基伸, 木佐
森慶一, 李清秀, 矢向謙太郎, 小林幹, 小林俊雄, 長谷川邦彦, 中村隆司, 近藤洋介, 栂野泰宏, 四方瑞紀, 坪田潤一, 齊藤敦美, 米田健一郎, 佐藤広海, 大津秀暁, 清水陽平, 本林
透, Doornenbal P., 馬場秀忠, 磯部忠昭, 松下昌史, 安田淳平, 坂口聡, 小林信之, Lapoux V., Gillibert A., 酒向正己,
進藤佑輔, 田端心海, 大倉綾華, Stuhl L., Korkulu Z., 清川裕, Flavigny F., Gibelin J., Orr N. A., Marques F. M.,
Yang Z., 金谷佳尚, 川上駿介.: “ボロミアン核 (p,pn) 反応を用いた二中性子運動量相関の研究”, 日本物理学会第 70
会年次大会, (早稲田大学), 東京, 3 月 (2015).
四方瑞紀，中村隆司，栂野泰宏，近藤洋介.: “ガンマ線カロ
リメータ CATANA のシミュレーション”, 日本物理学会第70 回年次大会, (早稲田大学), 東京, 3 月 (2015).
齊 藤 敦 美 ，近 藤 洋 介 ，中 村 隆 司 ，Nadia Lynda Achouri，Thomas Aumann，馬場秀忠，Franck Delaunay，Pieter
Doornenbal，福田直樹，Julien Gibelin，Jongwon Huang，
稲辺尚人，磯部忠昭，亀田大輔，簡野大輝，Sunji Kim，
小林信之，小林俊雄，久保敏幸，Sylvain Leblond，Jenny
Lee，Miguel Marques，南方亮吾，本林透，村井大地，村上哲也，武藤琴美，中嶋丈嘉，中塚徳継，Alahari Navin，
西征爾郎，生越駿，Nigel AndrewOrr，大津秀暁，佐藤広海，佐藤義輝，清水陽平，鈴木宏，高橋賢人，竹田浩之，武内聡，田中隆己，栂野泰宏 I，Adam Garry Tuﬀ，Marine
Vandebrouck，米田健一郎.: “中性子過剰 19 B の相互作用断面積”, 日本物理学会第 70 回年次大会, (早稲田大学), 東
京, 3 月 (2015).
栂野泰宏，南方亮吾，生越駿，中村隆司，磯部忠昭，稲辺尚人，
大津秀暁，亀田大輔，簡野大輝，久保敏幸，小林俊雄，小林
信之，近藤洋介，佐藤広海，佐藤義輝，清水陽平，鈴木宏，
高橋賢人，武内聡，竹田浩之，田中隆己，中嶋丈嘉，中塚徳継，西征爾郎，福田直樹，馬場秀忠，武藤琴美，村井大地，
村上哲也，本林透，米田健一郎，N. L. Achouri，A. G.
Tuﬀ，T. Aumann，F. Delaunay，J. Gibelin，J. Hwang，
S. Kim，J. Lee，M. Marques，A.Navin，N. A. Orr，P.
Doornenbal，S. Leblond，M. Vandebrouck.: “19,20,22 Cの反応断面積”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京, 3 月 (2015).
尾 崎 友 志 ，中 村 隆 司 ，栂 野 泰 宏 ，馬 場 秀 忠 ，中 塚 徳 継 ，Oliver Wieland，Thomas Aumann，他 RIBF 51/56/61
collaboration, “ピグミー共鳴測定用 LaBr3 検出器のエネ
ルギー較正”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京, 3 月 (2015).
栂野 泰宏:, “Symmetry energy and electric dipole responseof neutron-rich nuclei”, 新学術領域研究会「中性子星核物質」 2015 年 3 月, 京都大学.
近藤洋介.: “Island of Inversion の南側”, 九大研究会 –中性子過剰領域における弱束縛系の物理– , (九州大学箱崎キャンパス), 福岡 3 月 (2015).

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Ⅶ. LIST OF PUBLICATIONS

Computing and network Team
Publications[Journal]（Original Papers） *Subject to Peer Review
Baba H., Ichihara T., Ohnishi T., Takeuchi S., YoshidaK., Watanabe Y., Ota S., Shimoura S., Yoshinaga K.:“Time-stamping system for nuclear physics experiments
at RIKEN RIBF”, Nucl. Instr. Meth. A 777, 75–79(2015). ＊Oral Presentations(International Conference etc.)
Baba H., Ichihara T., Isobe T., Houarner C., Maugeais C.,
Raine B., Saillant F., Wittwer G., Kurz N., Schaﬀner
H., Gernhäuser R., Anvar S., Calvet D., Château
F., Pollacco E.: “DAQ Coupling in RIKEN RIBF”,
19th REAL TIME CONFERENCE (RT2014) , (RCNP,RIKEN, KEK), Nara, Japan, May (2014).
Baba H.: “Development of FPGA-based NIM logic circuits”, 4th Joint Meeting of the APS Division of Nuclear
Physics and the Physical Society of Japan , Waikoloa,
Hawaii, October (2014).
(Domestic Conference)
馬場秀忠, 市原卓, 大西哲哉, 武内聡, 渡邊康, 吉田光一, 大田晋介, 下浦享: “モジュールマウント型 VME コントローラの開発”, 日本物理学会, (日本物理学会), 平塚, 3 月 (2014).

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Detector Team
Publications[Journal]（Original Papers） *Subject to Peer Review
Sato Y., Shimaoka T., Kaneko J.H., Murakami H., Isobe
M., Osakabe M., Tsubota M., Ochiai K., Chayahara A.,
Umezawa H., Shikata S.: “Radiation hardness of a single
crystal CVD diamond detector for MeV energy protons”,
Nucl. Instr. and Meth. A 784, 147-150 (2014). ＊Sato Y., Murakami H., Shimaoka T., Tsubota M., Kaneko
J.H.: “Single-crystal CVD diamond detector for highresolution particle spectrometry”, Euro. Phys. Let.
108, 42001 (2014). ＊Sato Y., Shimaoka T., Kaneko J.H., Murakami H.,
Miyazaki D., Tsubota M., Chayahara A., Umezawa H.,
Shikata S.: “Pulse shape distortion of output signals
from single-crystal CVD diamond detector in few-GHz
broadband amplifiers”, Euro. Phys. Let. 106, 22001(2014). ＊Oral Presentations(International Conference etc.)
Sato Y., Fukuda N., Takeda H., Kameda D., Suzuki H.,
Shimizu Y., Ahn D.S., Murai D., Inabe N., Shimaoka
T., Tsubota M., Kaneko J.H., Chayahara A., Umezawa
H., Shikata S., Kumagai H., Murakami H., Yoshida K.,
Kubo T.: “Status of Beam Line Detectors for the BigRIPS Fragment Separator at RIKEN RI Beam Factory:
Issues on High Rates and Resolution”, The 2nd Conference on ”Advances in Radioactive Isotope Science 2014”(ARIS 2014), (RIKEN, U. Tokyo), Bunkyo, Japan, June(2014).
Sato Y., Shimaoka T., Kaneko J.H., Murakami H., Isobe
M., Nagakabe M., Tsubota M., Ochiai K., Chayahara
A., Umezawa H., Shikata S.: “Radiation hardness of
single crystal CVD diamond detector for MeV energy
protons”, SORMA XV - 2014 Symposium on Radiation
Measurements and Applications, (U. Michigan), Michigan, USA, June (2014).
Shimaoka T., Kaneko J.H., Arikawa Y., Isobe M., SatoY., Tsubota M., Nagai T., Kojima S., Abe Y., Sakata
T., Fujioka S., Nakai M., Shirakami H., Azechi H.,
Chayahara A., Umezawa H., Shikata S.: “Response measurement of single crystal CVD diamond radiation detector for intense X-rays aiming at burn-history measurement on an inertial confinement fusion with fast ignition”, SORMA XV - 2014 Symposium on Radiation
Measurements and Applications, (U. Michigan), Michigan, USA, June (2014).
Shimizu Y., Kubo T., Fukuda N., Ahn D.S., Inabe N.,
Kameda D., Sato H., Suzuki H., Takeda H., Yoshida K.:“Identification of 25 new neutron-rich isotopes producedin the EURICA uranium beam campaign at RIKEN
RIBF”, 4th Joint Meeting of the APS Division of Nu-

clear Physics and the Physical Society of Japan, (APS,
PSJ), Hawai, USA, October (2014).
Suzuki H., Kubo T., Fukuda N., Inabe N., Kameda D.,
Takeda H., Sato H., Shimizu Y., Ahn D.S., Ohkoda
Y., Iwasa N., Murai D.: “Production cross section ofneutron-deficient radioactive isotopes produced from a124
Xe beam at 345 MeV/u by the BigRIPS separator
at RIKEN RI Beam Factory”, 4th Joint Meeting of the
APS Division of Nuclear Physics and the Physical Society of Japan, (APS, PSJ), Hawai, USA, October (2014).
(Domestic Conference)
木佐森慶一, 下浦享, 李清秀, 井手口栄治, 稲辺尚人,
伊藤正俊, 上坂友洋, 大田晋輔, 亀田大輔, 川畑貴裕,
川瀬頌一郎, 菊地陽介, 久保敏幸, 久保田悠樹, 郷慎太郎,
小林幹, 近藤洋介, 坂口聡志, 酒井英行, 笹本良子,
笹野匡紀, 佐藤広海, 清水陽平, 鈴木宏, 高木基伸, 民井淳,
竹田浩之, 武内聡, 津村美保, 時枝紘史, 西隆博, 西村美月,
野地俊平, 馬場秀忠, 馬場辰彦, 堂園昌伯, 福田直樹,
藤井俊彦, 前田幸重, 松原礼明, 三木謙二郎, 道正新一郎,
宮裕之, 柳沢善行, 矢向謙太郎, 横山輪, 吉田光一,
M. Assie, D. Beaumel, F. Hammache, A. Stolz: “発熱型
二重荷電交換反応 4 He(8 He,8 Be)4n による 4 中性子系の研究”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京, 3
月 (2015).
小山俊平, 大津秀暁, 清水陽平, 米田健一郎, 佐藤広海,
本林透, 西村美月, 銭廣十三, 櫻井博儀, 武内聡, 磯部忠昭,
馬場秀忠, 日下健祐, 大西純一, 笹野匡紀, P. Doornenbal,
福田直樹, 小林俊雄, 炭竈聡之, 松田洋平, 佐藤義輝,
J. Hwang, 近藤洋介, 中村隆司, 栂野泰宏, 南方亮吾,
生越駿, 村上哲也, 中塚徳継, J. Gibelin, L. Sylvain,
新倉潤, 小林信之, H. Liu, J. Lee, E. Nikolskii, 坂口聡志,
D. Beaumel: “16 C クラスター準位探索実験”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京, 3 月 (2015).
久保田悠樹,
Anna Corsi,
笹野匡紀,
上坂友洋,
Alexandre Obertelli,
Clementine Santamaria,
Emanuel Pollacco, 銭廣十三, 堂園昌伯, 大田晋輔,
時枝紘史, 川瀬頌一郎, Tang Tsz Leung, 高木基伸,
木佐森慶一, 李清秀, 矢向謙太郎, 小林幹, 小林俊雄,
長谷川邦彦, 中村隆司, 近藤洋介, 栂野泰宏, 四方瑞紀,
坪田潤一, 齊藤敦美, 米田健一郎, 佐藤広海, 大津秀暁,
清水陽平,
本林透,
Pieter Doornenbal,
馬場秀忠,
磯部忠昭, 松下昌史, 安田淳平, 坂口聡, 小林信之,
Valerie Lapoux, Alain Gillibert, 酒向正己, 進藤佑輔,
田端心海, 大倉綾華, Laszlo Stuhl, Zeren Korkulu,
清川裕, Freddy Flavigny, Julien Gibelin, Nigel Orr,
Marques Miguel, Zaihong Yang, 金谷佳尚, 川上駿介: “ボロミアン核 (p,pn) 反応を用いた二中性子運動量相関の研究”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京,
3 月 (2015).
齊藤敦美, 近藤洋介, 中村隆司, Nadia Lynda Achouri,
馬場秀忠,
Franck Delaunay,
Thomas Aumann,
福田直樹,
Julien Gibelin,
Pieter Doornenbal,
Jongwon Huang,
稲辺尚人,
磯部忠昭,
亀田大輔,
簡野大輝, Sunji Kim, 小林信之, 小林俊雄, 久保敏幸,
Sylvain Leblond,
Jenny Lee,
Miguel Marques,- 507 -

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

南方亮吾, 本林透, 村井大地, 村上哲也, 武藤琴美,
中嶋丈嘉, 中塚徳継, Alahari Navin, 西征爾郎, 生越駿,
Nigel Andrew Orr, 大津秀暁, 佐藤広海, 佐藤義輝,
清水陽平, 鈴木宏, 高橋賢人, 竹田浩之, 武内聡, 田中隆己,
栂野泰宏,
Adam Garry Tuﬀ
Marine Vandebrouck,19
米田健一郎: “中性子過剰 B の相互作用断面積”, 日本物理学会第 70 回年次大会, (早稲田大学), 東京, 3 月 (2015).
栂野泰宏, 南方亮吾, 生越駿, 中村隆司, 磯部忠昭, 稲辺尚人,
大津秀暁, 亀田大輔, 簡野大輝, 久保敏幸, 小林俊雄,
小林信之, 近藤洋介, 佐藤広海, 佐藤義輝, 清水陽平,
鈴木宏, 高橋賢人, 武内聡, 竹田浩之, 田中隆己, 中嶋丈嘉,
中塚徳継, 西征爾郎, 福田直樹, 馬場秀忠, 武藤琴美,
村井大地, 村上哲也, 本林透, 米田健一郎, N. L. Achouri,
A. G. Tuﬀ, T. Aumann, F. Delaunay, J. Gibelin,
J. Hwangy, S. Kim, J. Lee, M. Marques, A.Navin,
N. A. Orr, P. Doornenbal, S. Leblond, M. Vandebrouck:“19,20,22 C の反応断面積”, 日本物理学会第 70 回年次大会,(早稲田大学), 東京, 3 月 (2015).

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Germany. (2015).

Ion Beam Breeding Team
Publications[Journal](Original Papers)*Subject to Peer Review
Inthima P., Otani M., Hirano T., Hayashi Y., Abe T.,
Nakano M., and Supaibulwatana K.: “Mutagenic effectsof heavy-ion beam irradiation on in vitro nodal
segments of Artemisia annua L.”, Plant Cell Tiss. Organ
Cult. 119, 131-139 (2014). *Nakano M., Yamada T., Masuda Y., Sato Y., Kobayashi H.,
Ueda H., Morita R., Nishimura M., Kitamura K., andKusaba M.: “A Green-Cotyledon/Stay-Green Mutant
Exemplifies the Ancient Whole-Genome Duplications inSoybean”, Plant Cell Physiol. 55(10), 1763-1771 (2014).
*
Nishiura A., Kazama Y., Abe T., Mizuno N., Nasuda S.,
and Murai K.: “Level of VERNALIZATION 1 expression
is correlated with earliness in extra early-floweringmutant wheat lines”, Breed Sci. 64(3), 213-221 (2014). *Maeda S., Gunji S., Hanai K., Hirano T., Kazama Y.,
Ohbayashi I., Abe T., Sawa S., Tsukaya S., and A.
Ferjani.: “The Conflict between cell proliferation andexpansion primarily affects stem organogenesis in
Arabidopsis”, Plant Cell Physiol. 55, 1994-2007 (2014). *Hara T., Kobayashi E., Ohtsubo K., Kumada S.,
Kanazawa M., Abe T., Itoh R. D., and Fujiwara M. T.:“Organ-level analysis of idioblast patterning in Egeria
densa Planch. leaves”, PLoS ONE 10, e0118965 (2015).*
Hirano T., Kazama Y., Ishii K., Ohbu S., Shirakawa Y.,
and Abe T.: “Comprehensive identification of mutations
induced by heavy-ion beam irradiation in Arabidopsis
thaliana”, Plant J. 82, 93-104 (2015). *(Review)
阿部知子, 風間裕介, 西美友紀, 永吉実孝: “九州ブランドを
世 界 に ！ ― 突 然 変 異 育 種 の 挑 戦 ― ”, 育 種 学 研 究 16,
67-71 (2014).
阿部知子, 福西暢尚: “重イオンビーム照射による農作物の品
種改良”, 電気評論 99, 51-55 (2014).
松田尚大, 竹下毅, 大田修平, 山﨑誠和, 風間裕介, 阿部知子, 平田愛子, 河野重行: “微細藻類への重イオンビーム照射によるバイオ燃料増産株の作出”, 生物工学会誌 92,602-606 (2014).
平野智也: “重イオンビームを利用した花卉園芸植物の育種”,
花葉 33(通巻第 34 号), 2-5 (2014).
[Book・Proceedings](Book)
池田時浩: “ガラスキャピラリーオプティクスによる収束と偏向”, マイクロビームアナリシス・ハンドブック, 第 I 編
基礎編 第 1 章 分析機器の主要構成 1.2.1 (5) P.71-73 オ
ーム社 (2014).
Shibata F., Kazama Y., Kawano S., Hizume M.:“Chromosome painting and FISH of distal end satellite
DNAs in dioecious plants with sex chromosomes” In:
Atlas of Plant Cell Structure. Noguchi T., Kawano S.,
Tsukaya H., Matsunaga S., Sakai A., Karahara I.,
Hayashi Y. (Eds.), pp14-15, Springer, Berlin/Heidelberg,

Oral Presentations(International Conference etc.)
Ikeda T.: “Cell irradiation with microbeams of MeV heavy
ions using glass capillaries”, Workshop on Applicationsof Highly Charged Ions (HCI App), East Lansing, MI,
USA, May (2014).
Abe T., Hayashi Y., Endo T., Saeki K., Sato H., Sakai M.,
and Sato T.: “DEVELOPMENT OF SALT-RESISTANT
RICE IN MIYAGI PREFECTURE”, 4th International
Rice Congress (IRC2014), Bangkok, Thailand, Oct.
(2014).
Ishii K., Hirano T., Kazama Y., Hamada M., Ono Y., and
Abe T.: “Pipeline for whole-genome analysis ofheavy-ion-induced mutants”, International Symposium
on Genome Science 2015 Expanding Frontiers ofGenome Science II, Tokyo, Japan, Jan. (2015).
(Domestic Conference)
常泉和秀, 阿部知子: “重イオンビーム照射によるキイロショ
ウジョウバエ変異系統の樹立系構築”, 日本農芸化学会
2014 年度大会, 川崎, 3 月 (2014).
平野智也: “重イオンビーム誘発変異の全ゲノム解析”, 植物
生存システム 春期研究成果発表会, 千葉, 4 月 (2014).
風間裕介: “ヒロハノマンテマ雄性決定領域の重イオン欠失マッピング”, 植物生存システム 春期研究成果発表会, 千葉, 4 月 (2014).
池田時浩: “ガラスキャピラリーによる細胞内組織 3 次元選択的破壊のためのマイクロイオンビーム照射”, 植物生存シ
ステム 臨時セミナー, 千葉, 5 月 (2014).
石井公太郎: “巡回セールスマン問題に帰着したヒロハノマ
ンテマ組換え抑制領域のマッピング”, 植物生存システム
臨時セミナー, 千葉, 5 月 (2014).
阿部知子: “イオンビームはすごいのだ！～いろんな植物で実証されるイオンビームの威力～”, 福井県立大学 コムギ
イオンビーム変異体観察会, 福井, 6 月 (2014).
宇都木萌, 池田時浩, 泉雅子, 平野智也, 小林知洋, 阿部知子, 酒井康弘: “ガラスキャピラリーを使ったマイクロビー
ム細胞照射法の開発、出射ビーム特性”, 第 15 回放射線プ
ロセスシンポジウム, 東京, 6 月 (2014).
阿部知子, 風間裕介, 平野智也: “イオンビーム育種の最近の展開”, 第 15 回放射線プロセスシンポジウム, 東京, 6 月(2014).
池田時浩, 小林知洋, Mäckel V., 泉雅子, 荻原清, 浜垣学,
平野智也, 小島隆夫, Puttaraksa N., 宇都木萌, 酒井康弘,
山崎泰規, 阿部知子: “ガラスキャピラリーを使ったマイク
ロビーム細胞照射法”, 第 15 回放射線プロセスシンポジウ
ム, 東京, 6 月 (2014).
泉雅子: “放射線による DNA 損傷修復機構と細胞応答”, 第51 回アイソトープ・放射線研究発表会, 東京, 7 月 (2014).
阿部知子: “イオンビーム育種研究会 10 年の歩み ―理化学研究所仁科加速器研究センターRI ビームファクトリー
（RIBF）―”, 第 10 回イオンビーム育種研究会, 水戸, 7
月 (2014).
竹下毅, 太田修平, 山崎誠和, 大島健志朗, 服部正平, 風間裕介, 阿部知子, 河野重行: “重イオンビーム照射によるク
ロレラの突然変異誘導率と屋外大量培養株の作出”, 第 10- 509 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

回イオンビーム育種研究会, 水戸, 7 月 (2014).
風間裕介, 石井公太郎, 池田時浩, 川元寛章, 河野重行, 阿部知子: “巡回セールスマン問題を応用した重イオンビー
ム欠失マッピング”, 第 10 回イオンビーム育種研究会, 水戸, 7 月 (2014).
阿部知子: “巨大加速器で発生する重イオンビームで黄色のサクラ、咲きました。”, 第 32 回日本植物細胞分子生物学会(盛岡)大会・シンポジウム, 盛岡, 8 月 (2014).
風間裕介, 平野智也, 阿部知子: “重イオンビーム育種の開発と品種改良ユーザー会”, 平成 26 年度 非破壊検査に関する研究発表会, 大阪, 8 月 (2014).
Ali F., 前田沙織理, 郡司玄, 花井研哉, 平野智也, 風間裕介,
大林祝, 阿部知子, 塚谷裕一: “細胞増殖と細胞伸長の異常
が茎の形態形成に及ぼす影響”, 日本植物形態学会第 26 回
総会・大会, 川崎, 9 月 (2014).
川元寬章, 石井公太郎, 風間裕介, 阿部知子, 河野重行: “ヒロハノマンテマへの黒穂菌を感染によって生じる葯に Y
染色体の関与はあるか”, 日本植物形態学会第 26 回総会・大会, 川崎, 9 月 (2014).
風間裕介, 石井公太郎, 池田時浩, 川元寛章, 河野重行, 阿部知子: “巡回セールスマン問題を応用したヒロハノマン
テマ雄性決定領域の欠失マッピング”, 日本植物学会第 78回大会, 川崎, 9 月 (2014).
石井公太郎, 風間裕介, 川元寛章, 河野重行, 阿部知子: “Y
染色体遺伝子アレイを用いたヒロハノマンテマ性分化ス
テージの発現プロファイリング”, 日本植物学会第 78 回大会, 川崎, 9 月 (2014).
川元寛章, 石井公太郎, 風間裕介, 阿部知子, 河野重行: “雌蕊も雄蕊もないヒロハノマンテマの無性花変異体に黒穂菌を感染させると起きる変化”, 日本植物学会第 78 回大会,
川崎, 9 月 (2014).
仁田坂英二, 星野敦, 阿部知子, 中野完: “宇宙種子実験によって得られたアサガオの変異体”, 日本宇宙生物科学会第28 回大会, 堺, 9 月 (2014).
二羽恭介, 阿部知子, 小檜山篤志: “養殖ノリにおける倍数性
育種の可能性 ―スサビノリと隠蔽種の種間交雑実験―”,
平成 26 年日本水産学会秋季大会, 福岡, 9 月 (2014).
風間裕介, 平野智也, 石井公太郎, 森田竜平, 村井耕二, 阿部知子: “Mutagenesis から Mutagenomics へ：重イオンビームを用いたオンデマンド変異誘発”, 第七回 TRS 研究会,
宮崎, 9 月 (2014).
風間裕介, 石井公太郎, 池田時浩, 川元寛章, 河野重行, 阿部知子: “巨大 Y 染色体との格闘～ヒロハノマンテマの性決定遺伝子の探索～”, 日本育種学会第 126 回講演会, 宮崎, 9 月 (2014).
高原学, 蝦名真澄, 森田竜平, 風間裕介, 阿部知子, 高溝正,中川仁: “イオンビーム変異体によるアポミクシス遺伝子
座乗領域の絞り込み”, 日本育種学会第 126 回講演会, 宮崎, 9 月 (2014).
西浦愛子, 風間裕介, 阿部知子, 水野信之, 那須田周平, 村
井耕二: “時計関連遺伝子 Wheat PHYTOCLOCK 1 の欠失コムギ変異体は短日応答が消失して極早生となる”, 日
本育種学会第 126 回講演会, 宮崎, 9 月 (2014).
阿部知子: “突然変異誘発研究は形態変異体の選抜からはじまる”, 第 19 回バイオテンプレート研究懇談会, 東京, 10
月 (2014).
金澤美加子, 小林永実, 原拓也, 大坪昴平, 熊田翔吾, 阿部知子, 伊藤竜一, 藤原誠: “オオカナダモにおける異型細胞形成パターンの解析”, 日本農芸化学会関東支部 2014 年度
支部大会, 埼玉, 10 月, (2014).
森田竜平, 石井公太郎, 林依子, 佐藤雅志, 阿部知子: “イネExome 解析による重イオンビーム誘発突然変異遺伝子の迅速決定”, 第 12 回先端農学研究センター・サテライトセ
ミナー, 仙台, 10 月 (2014).
佐藤陽一, 平野智也, 鈴木健, 伊藤泰, 阿部知子, 河野重行:“全国６産地の養殖ワカメの形態と生理学的特性の比較”,
平成 26 年度日本水産学会東北支部大会, 秋田, 11 月
(2014).
泉 雅 子 , 水 野 武 , 今 本 尚 子 , 阿 部 知 子 , 花 岡 文 雄 : “ヒ トMcm10 と Mcm2-7 複合体の相互作用の解析”, 第 37 回分子生物学会年会, 横浜, 11 月 (2014).
阿部知子: “放射線を用いた品種改良から変異遺伝子同定へ”,
東北エネルギー懇談会
第 59 回技術委員会, 仙台, 3 月(2015).
村井耕二, 西浦愛子, 水野信之, 那須田周平, 風間裕介, 阿部知子: “コムギにおける生物時計機能は短日応答性に必須である”, 第 56 回日本植物生理学会年会, 東京, 3 月(2015).
竹下毅, 山下雄一, 大田修平, 山﨑誠和, 大島健志朗, 服部
正平, 風間裕介, 阿部知子, 河野重行: “クロレラの重イオ
ンビーム照射による突然変異誘導と屋外大量培養株の作
出”, 第 39 回日本藻類学会, 福岡, 3 月 (2015).
佐藤陽一, 平野智也, 二羽恭介, 村上素子, 鈴木健, 伊藤泰,
阿部知子, 河野重行: “全国６産地の養殖ワカメの形態と栄養塩吸収特性の比較”, 第 39 回日本藻類学会, 福岡, 3 月(2015).
石井公太郎, 平野智也, 風間裕介, 浜田道昭, 小野幸輝, 阿部知子: “全ゲノム変異解析のためのパイプラインの構築”,
日本育種学会第 127 回講演会, 町田, 3 月 (2015).
道坂怜生, 増岡千裕, 津山睦, 阿部知子, 田中朋之: “イネ突然変異系統 13-45 における白未熟粒発生機構の解析 第 2
報：原因候補遺伝子の同定と発現量の比較”, 日本作物学会
第 239 回講演会, 藤沢, 3 月 (2015).
小玉雅晴, 田邊雄太, 平野智也, 阿部知子: “重イオンビーム
照射によるアジサイの花色変異体の作出”, 園芸学会 平成
27 年度春季大会, 千葉, 3 月 (2015).
加藤雅博, 正村典也, 正野仁慈, 岡本大作, 阿部知子, 今井
真介: “涙の出ない，辛みのないタマネギの作出と特性解析”,
園芸学会 平成 27 年度春季大会, 千葉, 3 月 (2015).
小林永実, 金澤美加子, 平野智也, 阿部知子, 伊藤竜一, 藤
原誠: “オオカナダモ葉緑体欠失細胞における細胞生物学的解析”, 日本農芸化学会 2015 年度大会, 岡山, 3 月,
(2015).
石川浩樹, 佐々木駿, 鈴木麻央, 平野智也, 風間裕介, 阿部知子, 伊藤竜一, 藤原誠: “シロイヌナズナ花粉発生過程における色素体増殖の解析”, 日本農芸化学会 2015 年度大会,
岡山, 3 月, (2015).
佐々木駿, 石川浩樹, 加賀谷奨, 風間裕介, 阿部知子, 伊藤
竜一, 藤原誠: “シロイヌナズナ葉緑体分裂異常変異体における花粉色素体の解析”, 日本農芸化学会 2015 年度大会,
岡山, 3 月, (2015).

- 510 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

RI Applications Team
Publications[Journal](Original Papers)*Subject to Peer Review
Haba H., Huang M., Kaji D., Kanaya J., Kudou Y.,
Morimoto K., Morita K., Murakami M., Ozeki K., SakaiR., Sumita T., Wakabayashi Y., Yoneda A., KasamatsuY., Kikutani Y., Komori Y., Nakamura K., Shinohara A.
Kikunaga H., Kudo H., Nishio K., Toyoshima A., and262Db
TsukadaK.,“Production
of
in
the
248Cm(19F,5n)262Db Reaction and Decay Properties of
262Db and 258Lr”, Phys. Rev. C 89, 024618 (2014).*
Sato N., Sato T. K., Asai M., Toyoshima A., Tsukada K., Li
Z. J., Nishio K., Nagame Y., Schädel M., Haba H.,
Ichikawa S., and Kikunaga H., “Production of 256Lr inthe 249,250,251Cf + 11B, 243Am + 18O, and 248Cm + 14N
Reactions”, Radiochim. Acta 102, 211 (2014).*
Murakami M., Haba H., Goto S., Kanaya J., and Kudo H.,“Production Cross Sections of Niobium and Tantalum
Isotopes in Proton-Induced Reactions on natZr and natHf
up to14 MeV”, Appl. Radiat. Isot. 90, 149 (2014).*
Khandaker M. U., Haba H., Otuka N., and Usman A. R.,“Investigation of (d,x) Nuclear Reactions on Natural
Ytterbium up to 24 MeV”, Nucl. Instr. and Meth. B 335,
8 (2014).*
Kasamatsu Y., Toyomura K., Shiohara N., Yokokita T.,
Komori Y., Kino A., Yoshimura T., Takahashi N., Haba
H., Kudou Y., Kikunaga H., Mitsugashira T., Ohtsuki T.,
Takamiya K., and Shinohara A., “Coprecipitation
Behaviors of Zr, Hf, and Th with Sm Hydroxide for
Chemical Study of Element 104, Rf”, J. Nucl. Radiochem.
Sci. 14, 7 (2014).*
Khandaker M. U., Haba H., Murakami M., Otuka N., andKassim H. A., “Deuteron-Induced Activation CrossSections on Natural Copper up to 24 MeV”, J. Radioanal.
Nucl. Chem. 302, 759 (2014).*
Even J., Yakushev A., Düllmann Ch. E., Haba H., Asai M.,
Sato T. K., Brand H., Di Nitto A., Eichler R., Fan F.L.,
Hartmann W., Huang M., Jäger E., Kaji D., Kanaya J.,
Kaneya Y., Khuyagbaatar J., Kindler B., Kratz J. V.,
Krier J., Kudou Y., Kurz N., Lommel B., Miyashita S.,
Morimoto K., Morita K., Murakami M., Nagame Y.,
Nitsche H., Ooe K., Qin Z., Schädel M., Steiner J.,
Sumita T., Takeyama M., Tanaka K., Toyoshima A.,
Tsukada K., Türler A., Usoltsev I., Wakabayashi Y.,
Wang Y., Wiehl N., and Yamaki S., “Synthesis andDetection of a Seaborgium Carbonyl Complex”, Science
345, 1491 (2014).*
Kawano M., Takeuchi A., Takahashi K., Imazu S., andMinami T., “Determination of Sources of Vermillion Usedin Japanese Burial Mound of Yayoi and Kofun Periods”,
ISIJ International, 54, 1155 (2014).*
Urabe T., Takahashi K., Kitagawa M., Sato T., Kondo T.,
Enomoto S., Kidera M., and Seto Y., “Development ofPortable Mass Spectrometer with Electron Cyclotron
Resonance Ion Source for Detection of Chemical Warfare

Agents in Air”, Spectrochim. Acta A: Molec. Biomolec.
Spectr., 120, 437 (2014).*
Toyoshima A., Miyashita S., Ooe K., Lerum H. V.,
Kitayama Y., Wada A., Asai M., Sato T. K., Kaneya Y.,
Komori Y., Yokokita T., Kasamatsu Y., Tsukada K.,
Kitatsuji Y., Nagame Y., Schädel M., Omtvedt J. P.,
Yokoyama A., Haba H., Shinohara A., and Kratz J. V.,“Preparatory On-Line Extraction Experiment of Group6 Elements Mo and W for a Reduction Study of Sg”,
JAEA-Review 2013-057, 33 (2014).
Toyoshima A., Ooe K., Miyashita S., Asai M., Attallah M.
F., Goto N., Gupta N. S., Haba H., Huang M., Kanaya J.,
Kaneya Y., Kasamatsu Y., Kitatsuji Y., Kitayama Y.,
Koga K., Komori Y., Koyama T., Kratz J. V., Lerum H.
V., Oshimi Y., Pershina V., Sato D., Sato T. K.,
Shigekawa Y., Shinohara A., Tanaka A., Tsukada K.,
Tsuto S., Yokokita T., Yokoyama A., Omtvedt J. P.,
Nagame Y., and Schädel M., “Chemical Studies of Mo
and W in Preparation of a Seaborgium (Sg) Reduction
Experiment Using MDG, FEC, and SISAK”, J.
Radioanal. Nucl. Chem. 303, 1169 (2015).*
Ooe K., Attallah M. F., Asai M., Goto N., Gupta N. S., Haba
H., Huang M., Kanaya J., Kaneya Y., Kasamatsu Y.,
Kitatsuji Y., Kitayama Y., Koga K., Komori Y., KoyamaT., Kratz J. V., Lerum H. V., Miyashita S., Oshimi Y.,
Pershina V., Sato D., Sato T. K., Shigekawa Y.,
Shinohara A., Tanaka A., Toyoshima A., Tsukada K.,
Tsuto S., Yokokita T., Yokoyama A., Omtvedt J. P.,
Nagame Y., and Schädel M., “Development of a New
Continuous Dissolution Apparatus with a Hydrophobic
Membrane for Superheavy Element Chemistry”, J.
Radioanal. Nucl. Chem. 303, 1317 (2015).*
Komori Y., Yokokita T., Kasamatsu Y., Haba H.,
Toyoshima A., Toyomura K., Nakamura K., Kanaya J.,
Huang M., Kudou Y., Takahashi N., and Shinohara A.,“Solid-liquid Extraction of Mo and W by Aliquat 336
from HCl Solutions toward Extraction Chromatography
Experiments of Sg”, J. Radioanal. Nucl. Chem. 303, 1385
(2015).*Kaji D., Morimoto K., Haba H., Wakabayashi Y., Kudou Y.,
Huang M., Goto S., Murakami M., Goto N., Koyama T.,
Tamura N., Tsuto S., Sumita T., Tanaka K., TakeyamaM., Yamaki S., and Morita K., “Startup of a New GasFilled Recoil Separator GARIS-II”, J. Radioanal. Nucl.
Chem. 303, 1523 (2015).*
Miyake F., Suzuki A., Masuda K., Horiuchi K., Motoyama
H., Matsuzaki H., Motizuki Y., Takahashi K., and Nakai
Y., “Cosmic Ray Event of A.D. 774–775 Shown in QuasiAnnual 10Be Data from the Antarctic Dome Fuji Ice
Core”, Geophys. Res. Lett., 42, 84 (2015).*
Even J., Ackermann D., Asai M., Block M., Brand H., Di
Nitto A., Düllmann Ch. E., Eichler R., Fan F., Haba H.,
Hartmann W., Hübner A., Heßberger F. P., Huang M.,
Jäger E., Kaji D., Kanaya J., Kaneya Y., Khuyagbaatar
J., Kindler B., Kratz J. V., Krier J., Kudou Y., Kurz N.,
Laatiaoui M., Lommel B., Maurer J., Miyashita S.,
Morimoto K., Morita K., Murakami M., Nagame Y.,- 511 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Nitsche H., Ooe K., Qin Z., Sato T. K., Schädel M.,
Steiner J., Sumita T., Takeyama M., Tanaka K.,
Toyoshima A., Tsukada K., Türler A., Usoltsev I.,
Wakabayashi Y., Wang Y., Wiehl N., Yakushev A., andYamaki S., “In-Situ Synthesis of Volatile Carbonyl
Complexes with Short-Lived Nuclides”, J. Radioanal.
Nucl. Chem. 303, 2457 (2015).*
Khandaker M. U., Haba H., Murakami M., and Otuka N.,“Production Cross-Sections of Long-Lived Radionuclides
in Deuteron-Induced Reactions on Natural Zinc up to 23
MeV”, Nucl. Instr. and Meth. B 346, 8 (2015).*Huang M., Haba H., Murakami M., Asai M., Kaji D.,
Kanaya J., Kasamatsu Y., Kikunaga H., Kikutani Y.,
Komori Y., Kudo H., Kudou Y., Morimoto K., Morita K.,
Nakamura K., Ozeki K., Sakai R., Shinohara A., SumitaT., Tanaka K., Toyoshima A., Tsukada K., Wakabayashi
Y., and Yoneda A., “Production of 88Nb and 170Ta for
Chemical Studies of Element 105, Db, Using the GARIS
Gas-Jet System”, J. Radioanal. Nucl. Chem. (in press).*
Wang Y., Qin Z., Fan F.L., Haba H., Komori Y., Cao S.W.,
Wu X.-L., and Tan C.-M., “Gas-Phase Chemistry ofTechnetium Carbonyl Complexes”, Phys. Chem. Chem.
Phys. (in press).*(Review)
羽場宏光, “GARIS が拓く新元素の化学”, 放射化学 30, 7(2014).*[Book · Proceedings](Original Papers)*Subject to Peer Review
Kaji D., Morimoto K., Haba H., Wakabayashi Y., Kudou Y.,
Huang M., Goto S., Murakami M., Goto N., Koyama T.,
Tamura N., Tsuto S., Sumita T., Tanaka K., TakeyamaM., Yamaki S., and Morita K., “Research andDevelopment of a New Gas-Filled Recoil Separator
GARIS-II”, Proceedings of the 12th Asia Pacific Physics
Conference, JPS Conf. Proc. 1, 013051 (2014).*
Oral Presentations(International Conference etc.)
Usoltsev I., Eichler R., Di Nitto A., Düllmann C., Fan F.L.,
Hartmann W., Huang M., Jäger E., Kaji D., Kanaya J.,
Kaneya Y., Khuyagbaatar J., Türler A., Kindler B.,
Kratz J., Krier J., Kudou Y., Kurz N., Lommel B.,
Miyashita S., Morimoto K., Morita K., Murakami M.,
Wang Y., Nagame Y., Nitsche H., Ooe K., Schädel M.,
Steiner J., Sumita T., Takeyama M., Tanaka K.,
Toyoshima A., Tsukada K., Even J., Wakabayashi Y.,
Wiehl N., Yamaki S., Qin Z., Yakushev A., Haba H., Asai
M., Sato T., Brand H., “Decomposition Studies of W andMo Carbonyl Complexes and Their Implications for
Future Experiments with Sg(CO)6”, 17th Radiochemical
Conference, (Division of Nuclear and Radiochemistry,
European Association for Chemical and Molecular
Sciences), Marianske Lazne, Czech Republic, May (2014).
Haba H., Kaji D., Kasamatsu Y., Kikunaga H., Komori Y.,
Kudo H., Morimoto K., Morita K., Murakami M., NishioK., Ooe K., Shinohara A., Toyoshima A., Tsukada K., andWakabayashi Y., “Production of 261Rf, 262Db, and 265Sg for

Chemical Studies Using GARIS at RIKEN”, 17th
Radiochemical Conference, (Division of Nuclear andRadiochemistry, European Association for Chemical andMolecular Sciences), Marianske Lazne, Czech Republic,
May (2014).
Murakami M., Goto S., Murayama H., Kojima T., Kaji D.,
Morimoto K., Haba H., Kudou Y., Sumita T., Sakai R.,
Yoneda A., Morita K., Kasamatsu Y., Kikunaga H., SatoT., and Kudo H., “Excitation Functions for Production of
Rutherfordium Isotopes in the 248Cm + 18O Reaction”,
17th Radiochemical Conference, (Division of Nuclear
and Radiochemistry, European Association for Chemicaland Molecular Sciences), Marianske Lazne, Czech
Republic, May (2014).
Attallah M. F., Lerum H. V., Toyoshima A., Ooe K.,
Miyashita S., Asai M., Goto N., Gupta N. S., Haba H.,
Huang M., Kanaya J., Kaneya Y., Kasamatsu Y.,
Kitatsuji Y., Kitayama Y., Koga K., Komori Y., KoyamaT., Kratz J. V., Oshimi Y., Pershina V., Sato D., Sato T.
K., Shigekawa Y., Shinohara A., Tanaka A., Tsukada K.,
Tsuto S., Yokokita T., Yokoyama A., Nagame Y., Schädel
M., and Omtvedt J. P., “Preliminary Investigations
towards the Separation of Hexavalent and Tetravalent
Seaborgium - Extraction of Homologs”, 17th
Radiochemical Conference, (Division of Nuclear andRadiochemistry, European Association for Chemical andMolecular Sciences), Marianske Lazne, Czech Republic,
May (2014).
Toyoshima A., Asai M., Attallah M. F., Goto N., Gupta N.
S., Haba H., Huang M., Kanaya J., Kaneya Y.,
Kasamatsu Y., Kitatsuji Y., Kitayama Y., Koga K.,
Komori Y., Koyama T., Kratz J. V., Lerum H. V.,
Miyashita S., Ooe K., Oshimi Y., Pershina V., Sato D.,
Sato T. K., Shigekawa Y., Shinohara A., Tanaka A.,
Tsukada K., Tsuto S., Yokokita T., Yokoyama A.,
Omtvedt J. P., Nagame Y., and Schändel M., “Electrolytic
Reduction Studies of Mo and W towards the Reductionof Seaborgium”, 17th Radiochemical Conference,(Division of Nuclear and Radiochemistry, European
Association for Chemical and Molecular Sciences),
Marianske Lazne, Czech Republic, May (2014).
Murakami M., Haba H., Goto S., and Kudo H., “Production
Cross Sections of Nb and Ta Isotopes in the (p,x) and(d,x) Reactions on natZr and natHf”, 17th Radiochemical
Conference, (Division of Nuclear and Radiochemistry,
European Association for Chemical and Molecular
Sciences), Marianske Lazne, Czech Republic, May (2014).
Omtvedt J. P., Koga K., Komori Y., Koyama T., Kratz J. V.,
Lerum H. V., Miyashita S., Ooe K., Oshimi Y., Pershina
V., Sato D., Sato T. K., Shigekawa Y., Shinohara A.,
Tanaka A., Toyoshima A., Tsukada K., Tsuto S., Yokokita
T., Yokoyama A., Nagame Y., Schädel M., Asai M.,
Attallah M. F., Goto N., Gupta N. S., Haba H., Huang M.,
Kanaya J., Kaneya Y., Kasamatsu Y., Kitatsuji Y., andKitayama Y., “Preparations for Redox Studies of
Seaborgium with SISAK Coupled to the Flow
Electrolytic Column FEC”, 17th Radiochemical- 512 -

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Conference, (Division of Nuclear and Radiochemistry,
European Association for Chemical and Molecular
Sciences), Marianske Lazne, Czech Republic, May (2014).
Haba H., “Production of Radioisotopes for Application
Studies at RIKEN”, The 27th World Conference of theInternational Nuclear Target Development Society(INTDS-2014), (RIKEN Nishina Center), Odaiba, Japan,
Sep. (2014).
Haba H., “Present Status and Future Plans of SHE
Researches at RIKEN”, 13th Workshop on Recoil
Separator for Superheavy Element Chemistry(TASCA14), Darmstadt, Germany, Oct. (2014).
Haba H., “Productions and Decay Studies of Transactinide
Elements for Superheavy Element Chemistry”, DAEBRNS 12th National Symposium on Nuclear andRadiochemistry (NUCAR-2015), (Board of Research in
Nuclear Sciences, Department of Atomic Energy;
Indian Association of Nuclear Chemists and Allied
Scientists), Mumbai, India, Feb. (2015).
Haba H., “Production and Decay Studies of 265Sg for
Chemical Studies of Seaborgium Using the Gas-Filled
Recoil Ion Separator GARIS at RIKEN”, 249th American
Chemical Society National Meeting & Exposition,(American Chemical Society), Denver, USA, Mar. (2015).
Takahashi K., Obi Y., and Tanaka M., “The Lead Isotopesof Aeolian Dust Observed at Saitama Area (Japan) and
Their Genetic Implications”, China-Japan-Korea
Symposium for Analytical Chemistry, (Research Center
for Analytical Sciences, Northeastern University),
Shenyang, China, Aug. (2014).
(Domestic Conference)
羽場宏光, “理研 RIBF における RI 製造応用”, 第 24 回金属の関与する生体関連反応シンポジウム（SRM2014），特別講演（兼市民講演会），(日本薬学会 物理系薬学部会), 京都市, 6 月 (2014).
加治大哉, 森本幸司, 羽場宏光, 若林泰生, 武山美麗, 山木
さやか, 田中謙吾, 長谷部裕雄, M. Huang, 金谷淳平, 村上昌史, 米田 晃 , 吉田 敦, 山口貴之, 門叶冬樹, 吉田友
美, Gan Z., Ma L., Geissel H., Hofmann S., Maurer Y., 藤田訓裕, 成清義博, 田中泰貴, 山本翔也, 浅井雅人, 鹿取
健二, 森田浩介, “GARIS を用いたホットフュージョン反応 248Cm+48Ca→296Lv*に関する研究”, 2014 日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋市, 9 月 (2014).
村上昌史, 羽場宏光, 黄 明輝, “natZr(d,x), natHf(d,x)反応による Nb, Ta 同位体の励起関数測定”, 2014 日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋市,
9 月 (2014).
笠松良崇, 豊村恵悟, 横北卓也, 重河優大, 高橋成人, 羽場
宏光, 小森有希子, 金谷淳平, 黄 明輝, 森田浩介, 村上昌史, 菊永英寿, 三頭聰明, 吉村 崇, 大槻勤, 高宮幸一, 篠
原 厚, “104 番元素 Rf の水酸化サマリウム共沈挙動”, 2014
日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋市, 9 月 (2014).
佐藤大輔, 村上昌史, 羽場宏光, 菊永英寿, 大江一弘, 後藤
真一, 工藤久昭, “Aliquat 336 を用いた Nb, Ta のフッ化水
素酸溶液からの溶媒抽出挙動”, 2014 日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋市, 9 月(2014).
津藤翔平, 村上昌史, 大江一弘, 後藤真一, 佐藤大輔, 後藤
尚哉, 長岡哲也, 羽場宏光, 豊嶋厚史, 工藤久昭, 小山 巧,
本山李沙, 小森有希子, 北山雄太, 福田芳樹, “Db の化学実験に向けた 5 族元素 Nb, Ta のオンライン逆相クロマトグ
ラフィー”, 2014 日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋市, 9 月 (2014).
北山雄太, 福田芳樹, 塚田和明, 豊嶋厚史, 羽場宏光, 菊永
英寿, 村上昌史, Huang M.H., 谷口拓海, 上野慎吾, 林 和憲, 横山明彦, “TTA 逆相クロマトグラフィーによる超重元素ラザホージウム(Rf)の吸着挙動”, 2014 日本放射化学会
年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋
市, 9 月 (2014).
加治大哉, 森本幸司, 羽場宏光, 若林泰生, 武山美麗, 山木
さやか, 田中謙吾, Huang M., 金谷淳平, 村上昌史, 浅井
雅人, 森田浩介, “気体充填型反跳分離装置 GARIS-II の非対称系反応に対する性能試験”, 2014 日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋市, 9 月(2014).
豊嶋厚史, 大江一弘, 宮下 直, 北山雄太, 小森有希子, 金谷佑亮, 後藤尚哉, 津藤翔平, 浅井雅人, 佐藤哲也, 塚田和明, 北辻章浩, Vascon A., 永目諭一郎, Schaedel M., 佐藤大輔, 押見吉成, 小山 巧, 田中 彰, 横山明彦, 羽場宏光,
Huang M., 笠松良崇, 重河優大, 横北卓也, 篠原 厚, 水
飼秋菜, 古賀和樹, 金子政志, Lerum H. V., Attallah M. F.,
Gupta N. S., Omtvedt J. P., Kratz J. V., Pershina V., “超アクチノイド元素シーボーギウム(Sg)の還元に向けた同族
元素 Mo と W の電解還元”, 2014 日本放射化学会年会・第58 回放射化学討論会, (日本放射化学会), 名古屋市, 9 月(2014).
横北卓也, 木野愛子, 重河優大, 豊村恵悟, 中村宏平, 笠松
良崇, 高橋成人, 安田勇輝, 吉村 崇, 小森有希子, 羽場宏
光, 金谷淳平, 黄 明輝, 村上昌史, 篠原 厚, “104 番元素
Rf 実験に向けた自動抽出装置を用いた Zr と Hf の固液抽出”, 2014 日本放射化学会年会・第 58 回放射化学討論会,(日本放射化学会), 名古屋市, 9 月 (2014).
加治大哉, 森本幸司, 羽場宏光, 森田浩介, “GARIS を用いた
113 番元素研究の総括”, 2014 日本放射化学会年会・第 58回放射化学討論会, (日本放射化学会), 名古屋市, 9 月(2014).
村上昌史, 羽場宏光, 柴田誠一, 工藤久昭, “natHf(α,x)反応の励起関数測定”, 2014 日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋市, 9 月 (2014).
小森有希子, 村上昌史, 羽場宏光, 柴田誠一, “natMo(d,x)反応による Tc 同位体の生成断面積測定”, 2014 日本放射化学会
年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋
市, 9 月 (2014).
後藤尚哉, 大江一弘, 村上昌史, 後藤真一, 工藤久昭, 塚田
和明, 豊嶋厚史, 浅井雅人, 佐藤哲也, 宮下 直, 金谷佑亮,
北山雄太, 羽場宏光, 小森有希子, “Sg の同族元素 Mo, Wのシュウ酸水溶液からのイオン対抽出挙動”, 2014 日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会),
名古屋市, 9 月 (2014).
福田芳樹, 北山雄太, 羽場宏光, 塚田和明, 豊嶋厚史, 菊永
英寿, Huang M.H., 村上昌史, 小森有希子, 千代西尾伊織,
後藤尚哉, 津藤翔平, 長岡哲也, 大江一弘, 谷口拓海, 上- 513 -

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Ⅶ. LIST OF PUBLICATIONS

野慎吾, 林 和憲, 横山明彦, “超重元素ラザホージウム(Rf)の溶液化学実験のための TTA 逆相クロマトグラフィーによる Zr, Hf の吸着挙動”, 2014 日本放射化学会年会・第 58回放射化学討論会, (日本放射化学会), 名古屋市, 9 月(2014).
脇谷雄一郎, 矢納慎也, 山田崇裕, 羽場宏光, 柴田誠一, 高
橋和也, “理研 AVF サイクロトロンを用いた頒布用 RI の調製(I)109Cd”, 2014 日本放射化学会年会・第 58 回放射化学討論会, (日本放射化学会), 名古屋市, 9 月 (2014).
矢納慎也, 脇谷雄一郎, 山田崇裕, 羽場宏光, 金谷淳平, 柴田誠一, 高橋和也, “理研 AVF サイクロトロンを用いた頒
布用 RI の調製(II)85Sr”, 2014 日本放射化学会年会・第 58回放射化学討論会, (日本放射化学会), 名古屋市, 9 月(2014).
羽場宏光, “理研における RI 製造応用”, 東北大学電子光理学
研究センター研究会「大強度電子ビームとその応用利用」,(東北大学電子光理学研究センター), 仙台市, 3 月 (2015)．
横北卓也，中村宏平，重河優大，安田勇輝，笠松良崇，高橋
成人，吉村 崇，羽場宏光，小森有希子，村上昌史，篠原 厚,“104 番元素 Rf の抽出挙動の時間依存性： バッチ型固液抽出装置を用いた Rf の Aliquat336/HCl 系の固液抽出”,
日本化学会第 95 春季年会, (日本化学会), 船橋市, 3 月(2015).
北山雄太，福田芳樹，羽場宏光，塚田和明，豊嶋厚史，菊永
英寿，小森有希子，村上昌史，上野慎吾，谷口拓海，林 和
憲，谷津由香里，千代西尾伊織，村上拳冬，横山明彦, “TTA
逆相クロマトグラフィーによる超重元素ラザホージウム(Rf)フッ化物錯体逐次形成の評価”, 日本化学会第 95 春季
年会, (日本化学会), 船橋市, 3 月 (2015).

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Industrial Cooperation Team
[Book · Proceedings]

Publications

吉田敦、神原正、上本龍二, ”RI ビーム打込み法を用いた摩耗検 査 法 の 開 発 ”, 月 刊 ト ラ イ ボ ロ ジ ー 2014-08 No324
pg.16-18,新樹社
吉田敦、神原正, ”研究室紹介 No.43 理化学研究所仁科加速器研究センター産業連携チーム”, 月刊トライボロジー
2015-02 No330 pg.66,新樹社

Oral Presentations(Domestic Conference)
吉田敦: “理研 RI ビームバラエティ（産業利用まで）”, 第54 回放射線科学研究会(エキゾチックビームシリーズ<12>), 大阪ニュークリアサイエンス協会, 大阪, 7 月(2014).

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RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Safety Management Group
Publications[Journal](Original Papers)
Mikami S., Maeyama T., Hoshide Y., Sakamoto R., Sato S.,
Okuda N., Demongeot S., Gurriaran R., Uwamino Y.,
Kato H., Fujiwara M., Sato T., Takemiya H., Saito K.:“Spatial Distributions of Radionuclides Deposited onto
Ground Soil Around the Fukushima Dai-Ichi Nuclear
Power Plant and their Temporal Change until
December 2012”, J. Environmental Radioactivity 139,
320 (2015).*[Book · Proceedings](Original Papers)
Tanaka K., Inabe N., Yoshida K., Kubo T.: " Evaluation ofradiation levels and comparison with PHITS
calculations for the BigRIPS separator in Radioactive
Isotope Beam Factory", Progress in Nuclear Science andTechnology 4, 201 (2014).*(Others)
上蓑義朋, 他 日本原子力学会「遮蔽」ハンドブック研究専門委員会,: “放射線遮蔽ハンドブック ―基礎編―”, 日本原子力学会 (2015).
Oral Presentations(International Conference etc.)
Nakao N., Uwamino Y., Tanaka K.: “Measurement of
Neutrons Generated by 345 MeV/u 238U Beam at
RIKEN RIBF”, 5th International Particle Accelerator
Conference (IPAC2014), Dresden, June (2014).
(Domestic Conference)
岡野眞治, 加藤博: “スペクトロメトリー解析”, 第 51 回ア
イソトープ・放射線研究発表会, (日本アイソトープ協会),
東京, 7 月(2014).
上蓑義朋, 岡野眞治, 加藤博, 向井弘樹、七沢潔、大森淳郎:“福島原発事故直後ならびに 3 年後の環境放射能推移”,
第 51 回アイソトープ・放射線研究発表会, (日本アイソトープ協会), 東京, 7 月(2014).
田中鐘信, 稲辺尚人, 吉田光一, 久保敏幸: "理化学研究所 RI
ビームファクトリー重イオン加速器施設における線量評
価", 日本原子力学会 2014 年秋の大会(日本原子力学会),
京都, 9 月, (2014).

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Center for Nuclear Study (CNS)
Graduate School of Science, the University of Tokyo

Publications[Journal]（Original Papers） *Subject to Peer Review
Tshoo K., Satou Y., Bertulani C.A., Bhang H., Choi
S., Nakamura T., Kondo Y., Deguchi S., Kawada Y.,
Nakayama Y., Tanaka K.N., Tanaka N., Togano Y.,
Kobayashi N., Aoi N., Ishihara M., Motobayashi T.,
Otsu H., Sakurai H., Takeuchi S., Yoneda K., DelaunayF., Gibelin J., Marques F.M., Orr N.A., Honda T.,
Kobayashi T., Sumikama T., Miyashita Y., Yoshinaga
K., Matsushita M., Shimoura S., Sohler D., Hwang J.W.,
Zheng T., Li Z.H., and Cao Z.X.: “Neutron occupancyof the 0d5/2 orbital and the N = 16 shell closure in 24 O”,
Phys. Lett. B 739, 19–22 (2014)
Muto H., Ohshiro Y., Yamaka S., Watanabe S., Oyaizu
M., Yamaguchi H., Kobayashi K., Kotaka Y., Nishimura
M., Kubono S., Kase M., Hattori T., and Shimoura S.:“Note: 6 Li III light intensity observation for 6 Li3+ ion
beam operation at Hyper-Electron Cyclotron Resonanceion source”, Rev. Sci. Instrum 85, 126107 (2014)
Crawford H.L., Fallon P., Macchiavelli A.O., Clark
R.M., Brown B.A., Tostevin J.A., Bazin D., Aoi N.,
Doornenbal P., Matsushita M., Scheit H., SteppenbeckD., Takeuchi S., Baba H., Campbell C.M., Cromaz M.,
Ideguchi E., Kobayashi N., Kondo Y., Lee G., Lee I.Y.,
Lee J., Li K., Michimasa S., Motobayashi T., Nakamura
T., Ota S., Paschalis S., Petri M., Sako T., Sakurai
H., Shimoura S., Takechi M., Togano Y., Wang H.,
and Yoneda K.: “Shell and shape evolution at N=28:
The 40Mg ground state”, Phys. Rev. C 89, 41303 (2014)
Patel Z., Soderstrom P.A., Podolyak Zs., Regan P.H.,
Walker P.M., Watanabe H., Ideguchi E., Simpson G.S.,
Liu H.L., Nishimura S., Wu Q., Xu F.R., BrowneF., Doornenbal P., Lorusso G., Rice S., Sinclair L.,
Sumikama T., Wu J., Xu Z.Y., Aoi N., Baba H.,
Bello Garrote F.L., Benzoni G., Daido R., Fang Y.,
Fukuda N., Gey G., Go S., Gottardo A., Inabe N.,
Isobe T., Kameda D., Kobayashi K., Kobayashi M.,
Komatsubara T., Kojouharov I., Kubo T., Kurz N.,
Kuti I., Li Z., Matsushita M., Michimasa S., Moon
C.B., Nishibata H., Nishizuka I., Odahara A., SahinE., Sakurai H., Schaﬀner H., Suzuki H., Takeda
H., Tanaka M., Taprogge J., Vajta Zs., Yagi A.,
and Yokoyama R.: “Isomer Decay Spectroscopy of164
Sm and166 Gd: Midshell Collectivity Around N =100”, Phys. Rev.Lett. 113 262502 (2014)
Michimasa S., Yanagisawa Y., Inafuku K., Aoi N., Elekes
Z., Fülöp Zs., Ichikawa Y., Iwasa N., Kurita K.,
Kurokawa M., Machida T., Motobayashi T., Nakamura
T., Nakabayashi T., Notani M., Ong H.J., OnishiT., Otsu H., Sakurai H., Shinohara M., SumikamaT., Takeuchi S., Tanaka K., Togano Y., Yamada K.,
Yamaguchi M., and Yoneda K.: “Quadrupole collectivity in island-of-inversion nuclei 28,30 Ne and 34,36 Mg”,
Phys. Rev. C 89, 054307 (2014)
Doornenbal P., Scheit H., Takeuchi S., Utsuno Y., Aoi
N., Li K., Matsushita M., Steppenbeck D., Wang H.,
Baba H., Ideguchi E., Kobayashi N., Kondo Y., Lee
J., Michimasa S., Motobayashi T., Otsuka T., Sakurai
H., Takechi M., Togano Y., and Yoneda K.: “Rotational
level structure of sodium isotopes inside the “island of inversion”, Prog. Theor. Exp. Phys. 2014, 053D01 (2014)
Kobayashi N., Nakamura T., Kondo Y., Tostevin J.A.,
Utsuno Y., Aoi N., Baba H., Barthelemy R., Famiano
M.A., Fukuda N., Inabe N., Ishihara M., Kanungo R.,
Kim S., Kubo T., Lee G.S., Lee H.S., Matsushita M.,
Motobayashi T., Ohnishi T., Orr N.A., Otsu H., OtsukaT., Sako T., Sakurai H., Satou Y., Sumikama T., Takeda
H., Takeuchi S., Tanaka R., Togano Y., and Yoneda K.:“Observation of a p-Wave One-Neutron Halo Conﬁguration in 3 7Mg”, Phys. Rev.Lett. 112 242501 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Productionof charged pions, kaons and protons at large transverse√
momenta in pp and PbPb collisions at sNN =2.76 TeV”,
Phys. Lett. B 736, 196 (2014)
Adare A. et al. [PHENIX Collaboration]: “Azimuthalangle dependence of charged-pion-interferometry measurements with respect to second- and third-order event√
planes in Au+Au collisions at sN N = 200 GeV”, Phys.
Rev. Lett. 112, no. 22, 222301 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Performanceof the ALICE Experiment at the CERN LHC”, Int. J.
Mod. Phys. A 29, 1430044 (2014)
Adare A. et al. [PHENIX Collaboration]: “Inclusive
double-helicity asymmetries in neutral-pion and eta√
meson production in p⃗+p
⃗ collisions at s = 200 GeV”,
Phys. Rev. D 90, no. 1, 012007 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Measurementof quarkonium production at forward rapidity in pp col√lisions at s = 7 TeV”, Eur. Phys. J. C 74, no. 8, 2974
(2014)
Abelev B.B. et al. [ALICE Collaboration]: “Freeze-out
radii extracted from three-pion cumulants in pp, pPb
and PbPb collisions at the LHC”, Phys. Lett. B 739,
139 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Measurement√of visible cross sections in proton-lead collisions at sNN= 5.02 TeV in van der Meer scans with the ALICE detector”, JINST 9, no. 11, P11003 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Azimuthal
anisotropy of D meson production in Pb-Pb collisions√
at sNN = 2.76 TeV”, Phys. Rev. C 90, no. 3, 034904(2014)
Abelev B.B. et al. [ALICE Collaboration]: “Transverse
momentum dependence of inclusive primary charged√sNN =particle production in p-Pb collisions at- 517 -

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Ⅶ. LIST OF PUBLICATIONS

5.02 TeV”, Eur. Phys. J. C 74, no. 9, 3054 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Measurementof prompt D-meson production in p − P b collisions at√
sN N = 5.02 TeV”, Phys. Rev. Lett. 113, no. 23,232301 (2014)
Adare A. et al. [PHENIX Collaboration]: “Measurementof KS0 and K ∗0 in p + p, d + Au, and Cu + Cu collisions√
at sN N = 200 GeV”, Phys. Rev. C 90, no. 5, 054905(2014)
Abelev B.B. et al. [ALICE Collaboration]: “Neutral pion
production at midrapidity in pp and Pb-Pb collisions at√
sNN = 2.76 TeV”, Eur. Phys. J. C 74, no. 10, 3108
(2014)
Abelev B.B. et al. [ALICE Collaboration]: “Suppression√of ψ(2S) production in p-Pb collisions at sN N = 5.02
TeV”, JHEP 1412, 073 (2014)
Adare A. et al. [PHENIX Collaboration]: “Low-mass
vector-meson production at forward rapidity in p+p col√lisions at s = 200 GeV”, Phys. Rev. D 90, no. 5,052002 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Beauty pro√duction in pp collisions at s = 2.76 TeV measured via
semi-electronic decays”, Phys. Lett. B 738, 97 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Suppression of Υ(1S) at forward rapidity in Pb-Pb collisions√
at sNN = 2.76 TeV”, Phys. Lett. B 738, 361 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Multiparticle
azimuthal correlations in p -Pb and Pb-Pb collisions at
the CERN Large Hadron Collider”, Phys. Rev. C 90,
no. 5, 054901 (2014)
Adare A. et al. [PHENIX Collaboration]: “Cross section
and transverse single-spin asymmetry of η mesons in p↑ +√p collisions at s = 200 GeV at forward rapidity”, Phys.
Rev. D 90, no. 7, 072008 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “ExclusiveJ/ψ photoproduction oﬀ protons in ultra-peripheral p√
Pb collisions at sNN = 5.02 TeV”, Phys. Rev. Lett.
113, no. 23, 232504 (2014)
Abelev B. et al. [ALICE Collaboration]: “Upgrade of the
ALICE Experiment: Letter Of Intent”, J. Phys. G 41,
087001 (2014)
Abelev B. et al. [ALICE Collaboration]: “Technical Design Report for the Upgrade of the ALICE Inner Tracking System”, J. Phys. G 41, 087002 (2014)
Abelev B.B. et al. [ALICE Collaboration]: “Event-byevent mean pT ﬂuctuations in pp and Pb-Pb collisions
at the LHC”, Eur. Phys. J. C 74, no. 10, 3077 (2014)
Doornenbal P., Takeuchi S., Aoi N., Matsushita M.,
Obertelli A., Steppenbeck D., Wang H., Audirac L.,
Baba H., Bednarczyk P., Boissinot S., Ciemala M., Corsi
A., Furumoto T., Isobe T., Jungclaus A., Lapoux V.,
Lee J., Matsui K., Motobayashi T., Nishimura D., Ota
S., Pollacco E.C., Sakurai H., Santamaria C., ShigaY., Sohler D., and Taniuchi R.: “Intermediate-energy
Coulomb excitation of Sn-104: Moderate E2 strength- 518 -

decrease approaching Sn-100”, Phys. Rev. C 90, 061302(2014)
Satou .Y, Hwang. JW, Kim S., Tshoo K., Choi S.,
Nakamura T., Kondo Y., Matsui M., Hashimoto Y.,
Nakabayashi T., Okumura T., Shinohara M., FukudaN., Sugimoto T., Otsu H., Togano Y., Motobayashi T.,
Sakurai H., Yanagisawa Y., Aoi N., Takeuchi S., Gomi
T., Ishihara M., Kawai S., Ong H.J., Onishi T.K., Shimoura S., Tamaki N., Kobayashi T., Matsuda Y., EndoN., Kitayama N.; “One-neutron knockout reaction of
17C on a hydrogen target at 70 MeV/nucleon ”, Phys.
Lett. B 728 (2014) 462–466.
Muto H., Ohshiro Y., Yamaka S., Watanabe S., Oyaizu
M., Kubono S., Yamaguchi H., Kase M., Hattori T.,
Shimoura S.: “Plasma spectroscopy of metal ions for
hyper-electron cyclotron resonance ion source”, Rev. Sci.
Instrum. 85 (2014) 02A905.
Zhang L.Y., He J.J., Parikh A., Xu S.W., Yamaguchi H.,
Kahl D., Kubono S., Mohr R., Hu J., Ma P., Chen S.Z.,
Wakabayashi Y., Wang H.W., Tian W.D., Chen R.F.,
Guo B., Hashimoto T., Togano Y., Hayakawa S., Teranishi T., Iwasa M., Yamada T., Komatsubara T., Zhang
Y.H., Zhou X.H., “Investigation of the thermonuclear
18
Ne(α,p)21 Na reaction rate via resonant elastic scattering of 21 Na+p”, Phys. Rev. C 89 (2014) 015804.
Hu J., He J.J., Parikh A., W. S., Yamaguchi H.,
Kahl D., Ma P., Su J., Wang H.W., Nakao T.,
Wakabayashi Y., Teranishi T., Hahn K.I., Moon J.Y.,
Jung H.S., Hashimoto T., Chen A.A., Irvine D., Lee
C.S., and Kubono S.: “Examination of the role of the
14O(alpha, p)17F reaction rate in type-I x-ray bursts”,
Phys. Rev. C 90, 025803 (2014)
Mcneice E., Setoodehnia K., Singh B., Abe Y., Binh
D., Chen A., Chen J., Cherubini S., Fukuoka S.,
Hashimoto T., Hayakawa T., Ishibashi Y., Ito Y., Kahl
D., Komatsubara T., Kubono S., Moriguchi T., Nagae
D., Nishikiori R., Niwa T., Ozawa A., Shizuma T.,
Suzuki H., Yamaguchi H., and Yuasa T.: “In-beam γray spectroscopy of 30 P via the 28 Si(3He,pγ)30 P reaction”, Nuclear Data Sheets 120, 88–90 (2014)
Imai N., Mukai M., Cederkall J., Aghai H., Golubev
P., Johansson H.T., Kahl D., Kurcewics J., TeranishiT., and Watanabe Y.X.: “Isobaric analog resonances of31
Mg and the border of the island of inversion”, Phys.
Rev. C 90, 011302 (2014)
Komatsubara T., Kubono S., Hayakawa T., Shizuma T.,
Ozawa A., Ito Y., Ishibashi Y., Moriguchi T., Yamaguchi
H., Kahl D., Hayakawa S., Binh D.N., Chen A.A., ChenJ., Setoodehnia K., and Kajino T.: “Excited states
above the proton threshold in 26 Si”, Eur. Phys. J. A
50, 136 (2014)
Spitaleri C., Lamia L., Puglia S.M.R.., Romano S.,
La Cognata M., Crucilla V., Pizzone R.G., Rapisarda
G.G., Sergi M.L., Del Santo M.G., Carlin N., Munhoz
M.G., Souza F.A., Szanto de A., Tumino A., Irgaziev

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Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

B., Mukhamedzhanov A., Tabacaru G., Burjan V.,
Kroha V., Hons Z., Mrazek J., Zhou S.H., Li C.,
Wen Q., Wakabayashi Y., Yamaguchi H., and Somorjai
E.: “Measurement of the 10 keV resonance in the
10
B(p,α0 )7 Be reaction via the trojan horse method”,
Phys. Rev. C 90, 035801 (2014)
Jung H.S., Lee C.S., Kwon Y.K., Moon J.Y., Lee J.H., Yun
C.C., Kim M.J., Hashimoto T., Yamaguchi H., Kahl
D., Kubono S., Wakabayashi Y., Togano Y., Choi S.,
Kim Y.H., Kim Y.K., Park J.S., Kim E.J., Moon C.B.,
Teranishi T., Iwasa N., Yamada T., Kato S., CherubiniS., Hayakawa S., and Rapisarda: G.: “Elastic scatteringof 25 Al+p to explore the resonance structure in 26 Si”,
Phys. Rev. C 90 035805 (2014)
Y. Tsunoda, T. Otsuka, N. Shimizu, M. Honma, andY. Utsuno, “Novel shape evolution in exotic Ni isotopes
and conﬁguration-dependent shell structure”, PhysicalReview C 89 (2014) 031301(R).
Yuan C., Qi C., Xu F., Suzuki T., and Otsuka T.: “Mirror energy diﬀerence and the structure of loosely boundproton-rich nuclei”, Phys. Rev. C 89, 044327 (2014)
Watanabe H. , Lorusso G., Nishimura S., Otsuka T.,
Ogawa K., Xu Z.Y., Sumikama T., Sderstrm P.A.,
Doornenbal P., Li Z., Browne F., Gey G., Jung H.S.,
Taprogge J., Vajta Zs., Wu J., Yagi A., Baba H., Benzoni G., Chae K.Y., Crespi F.C.L., Fukuda N., Gernhuser R., Inabe N., Isobe T., Jungclaus A., Kameda
D., Kim G.D., Kim Y.K., Kojouharov I., Kondev F.G.,
Kubo T., Kurz N., Kwon Y.K., Lane G.J., Moon C.-B.,
Montaner-Piz A., Moschner K., Naqvi F., Niikura M.,
Nishibata H., Nishimura D., Odahara A., Orlandi R.,
Patel Z., Podolyk Zs., Sakurai H., Schaﬀner H., Simpson G.S., Steiger K., Suzuki H., Takeda H., Wendt A.,
and Yoshinaga K. : “Monopole-Driven Shell Evolution
below the Doubly Magic Nucleus Sn 132 Explored with
the Long-Lived Isomer in Pd 126 ”. Physical review
letters, 113 (4), 042502.
Doornenbal P., Scheit H., Takeuchi S., Utsuno Y., Aoi
N., Li K., Matsushita M., Steppenbeck D., Wang H.,
Baba H., Ideguchi E., Kobayashi N., Kondo Y., Lee J.,
Michimasa S., Motobayashi T., Otsuka T., Sakurai H.,
Takechi M., Togano Y., and Yoneda K.: “Rotational
level structure of sodium isotopes inside the ”island of
inversion”, Prog. Theor. Exp. Phys. 2014, 053D01(2014)
Kobayashi N., Nakamura T., Kondo Y., Tostevin J.A.,
Utsuno Y., Aoi N., Baba H., Barthelemy R., Famiano
M.A., Fukuda N., Inabe N., Ishihara M., Kanungo R.,
Kim S., Kubo T., Lee G.S., Lee H.S., Matsushita M.,
Motobayashi T., Ohnishi T., Orr N.A., Otsu H., OtsukaT., Sako T., Sakurai H., Satou Y., Sumikama T., Takeda
H., Takeuchi S., Tanaka R., Togano Y., and Yoneda K.:“Observation of a p-Wave One-Neutron Halo Conﬁguration in 37Mg ”, Phys. Rev. Lett. 112, 242501 (2014)
Nakamura T., Kobayashi N., Kondo Y., Satou Y., Tostevin

J.A., Utsuno Y., Aoi N., Baba H., Fukuda N., Gibelin
J., Inabe N., Ishihara M., Kameda D., Kubo T., Motobayashi T., Ohnishi T., Orr N.A., Otsu H., OtsukaT., Sakurai H., Sumikama T., Takeda H., Takeshita E.,
Takechi M., Takeuchi S., Togano Y., and Yoneda K.:“Deformation-Driven p-Wave Halos at the Drip Line:
31Ne ”, Phys. Rev. Lett. 112, 142501 (2014)
Sanetullaev A., Tsang M.B., Lynch W.G., Lee Jenny,Bazin D., Chan K.P., Coupland D., Henzl V., Henzlova D., Kilburn M., Rogers A.M., Sun Z.Y., Youngs
M., Charity R.J., Sobotka L.G., Famiano M., Hudan
S., Shapira D., Peters W.A., Barbieri C., Hjorth-Jensen
M., Horoi M., Otsuka T., Suzuki T., Utsuno Y. : “Neutron spectroscopic factors of 55Ni hole-states from imagetransfer reactions”, Phys. Lett. B 736, 137 (2014)[Book・Proceedings]（Original Papers） *Subject to Peer Review
Ajitanand N.N. et al. [PHENIX Collaboration]: “Comparison of the space-time extent of the emission source√in d+Au and Au+Au collisions at sN N = 200 GeV”,
Nucl. Phys. A 931, 1082 (2014)
Ball M. et al. [ALICE TPC Collaboration]: “Ion backﬂow studies for the ALICE TPC upgrade with GEMs”,
JINST 9, C04025 (2014)
Gunji T. [ALICE Collaboration]: “Future Upgrade andPhysics Perspectives of the ALICE TPC”, Nucl. Phys.
A 931, 1152 (2014)
Sako H., Chujo T., Gunji T., Harada H., Imai K., Kaneta
M., Kinsho M. and Liu. Y et al.: “Towards the heavyion program at J-PARC”, Nucl. Phys. A 931, 1158
(2014)
Maeda Y., Saito T., Miyasako H., Uesaka T., Ota S.,
Kawase S., Kikuchi T., Tokieda H., Kawabata T., YakoK., Wakasa T., Sakaguchi S., Chen R., Sakaguchi H.,
Shima T., Suzuki T., and Tamii A.: “Measurement of
the H-2(p,n) Breakup Reaction at 170 MeV and theThree-Nucleon Force Eﬀects”, Few-Body Systems, 55,
729-732 (2014)
Yamaguchi H., Kahl D., Nakao T., Wakabayashi Y.,
Kubono S., Hashimoto T., Hayakawa S., Kawabata T.,
Iwasa N., Teranishi T., Kwon Y.K., Lee P.S., Binh D.N.,
Khiem L.H., and Duy N.N.: “Studies on alpha-induced
astrophysical reactions using the low-energy RI beam
separator CRIB” EPJ Web of Conferences 66, 07027(2014).
Kobayashi M., Yako K., Shimoura S., Dozono M., Kawase
S., Kisamori K., Kubota Y., Lee C.S., Michimasa S.,
Miya H., Ota S., Sakai H., Sasano M., Takaki M., “Measurement of the 8 He(p, n)8 Li reaction at intermediate
energy in inverse kinematics”, Proceedings of the 12th
Asia Paciﬁc Physics Conference (APPC12), Jul. 14–19,
2013, Makuhari, Japan, JPS Conf. Proc. 1, 013034(2014)
Kubota Y., Sasano M., Uesaka T., Dozono M., Itoh M.,
Kawase S., Kobayashi M., Lee C.S., Matsubara H., Miya

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Ⅶ. LIST OF PUBLICATIONS

H., Ota S., Sekiguchi K., Taguchi T., Tang T.L., Tokieda
H., and Wakui T.; “A new neutron detector with a highposition resolution for the study of the (p,pn) reaction
on rare isotopes”, EPJ Web of Conferences Vol. 66, No.
11022 (2014).
Kahl D., Hashimoto T., Duy N.N., Kubono S., Yamaguchi
H., Binh D.N., Chen A.A., Cherubini S., Hayakawa S.,
He J.J., Ishiyama H., Iwasa N., Khiem L.H., Kwon Y.K.,
Michimasa S., Nakao T., Ota S., Teranishi T., Tokieda
H., Wakabayashi Y., Yamada T., and Zhang L.Y.: “Active target studies of the αp-process at CRIB”, AIP Conference Proceedings 1594, 163–170 (2014)
He J.J., Hu J., Zhang L.Y., Xu S.W., Parikh A.,
Yamaguchi H., Kahl D., Ma P., Chen S.Z., Su J.,
Wakabayashi Y., Togano Y., Hayakawa S., Wang H.W.,
Tian W.D., Chen R.F., Guo B., Nakao T., Teranishi T.,
Moon J.Y., Jung H.S., Hashimoto T., Chen A.A., Irvine
D., Hahn K.I., Iwasa N., Yamada T., Komatsubara T.,
Lee C.S., Kubono S.: “Astrophysics studies relevant
to stellar X-ray bursts”, AIP Conference Proceedings
1594, 176–183 (2014)
Cherubini S., Gulino M., Spitaleri C., La Cognata M.,
Lamia L., Puglia S., Rapisarda G., Romano S., Kubono
S., Yamaguchi H., Binh D., Hayakawa S., Kurihara Y.,
Wakabayashi Y., Bishop S., Coc A., De Sereville N.,
and Hammache F.: “First results of trojan horse method
using radioactive ion beams: 18 F(p,α) at astrophysicalenergies”, AIP Conference Proceedings 1594, 184–189(2014)
Yamaguchi H., Kahl D., Nakao T., Wakabayashi Y.,
Kubano S., Hashimoto T., Hayakawa S., Kawabata T.,
Iwasa N., Teranishi T., Kwon Y.K., Binh D.N., Khiem
L.H., and Duy N.G.: “Alpha resonant scattering for astrophysical reaction studies”, AIP Conference Proceedings 1594, 220–225 (2014)
Yamaguchi H., Kahl D., Nakao T., Wakabayashi Y.,
Hashimoto T., Hayakawa S., Kawabata T., TeranishiT., Kwon Y.K., Binh D.N., Khiem L.H., Duy N.N.,
Kubono S., Suhara T., Kanada-En’yo Y., Moon J.Y.,
Kim A., Iwasa N., Lee P.S., Chae K.Y., Cha S.M.,
Gwak M.S., Kim D.H., and Milman E.: “Nuclear clusters studied with alpha resonant scatterings using RI
beams at CRIB”, Journal of Physics: Conference Series
569, 012019 (2014)
Shimizu N., Abe T., Honma M., Otsuka T., Tsunoda Y.,
Utsuno Y., and Yoshida T. : “Frontier of nuclear shellmodel calculations and high performance computing”,
accepted, JPS conference proceedings, ARIS2014
Utsuno Y., Otsuka T., Tsunoda Y., Shimizu N., Honma
M., Togashi T., and Mizusaki T.: “Recent Advances in Shell Evolution with Shell-Model calculations”, arXiv:1409.4506[nucl-th], accepted, JPS conference proceedings, ARIS2014
Togashi T., Shimizu N., Utsuno Y., Abe T., and Otsuka T. : “GPGPU Application to the Computation ofHamiltonian Matrix Elements between Non-orthogonal
Slater Determinants in Monte Carlo Shell Model”, Proc.
Comp. Sci. 29, 1711 (2014)
Abe T., Maris P., Otsuka T., Shimizu N., Utsuno Y.,and
Vary J.P.: “Monte Carlo Shell Model for ab initio nuclear structure”, EPJ Web Conf. 66, 02001 (2014)
Tsunoda Y., Otsuka T., Shimizu N., Honma M., and Utsuno Y. : “Study of nuclei around Z = 28 by large-scale
shell model calculations”, EPJ Web Conf. 66, 02105(2014)
Utsuno Y., Otsuka T., Shimizu N., Honma M., MizusakiT., Tsunoda Y., and Abe T. : “Recent shell-model results for exotic nuclei”, EPJ Web Conf. 66, 02106 (2014)
Yoshida T., Shimizu N., Abe T., and Otsuka T. : “Density profiles of light nuclei in Monte Carlo shell-model
calculation”, EPJ Web Conf. 66, 02113 (2014)
Iwata Y.: “Co-existence of states in quantum systems”, J.
Phys. Conf. Ser. 569 (2014) 012029
Iwata Y.: “Present Status of Fission Research Based on
TDDFT”, The proceedings of the 2014 symposium on
nuclear data, to appear.
Iwata Y., Shimizu N., Utsuno Y., Honma M., Abe T.,
and Otsuka T. : “Ingredients of nuclear matrix element
for two-neutrino double-beta decay of 48Ca”, JPS Conf.
Proc. Volume 6 (2015), to appear.
Yoshida T., Shimizu N., Abe T., and Otsuka T. : “Appearance of -cluster structure in Be isotopes based onMonte Carlo shell model”, Journal of Physics: Conference Series, 569, 012063 (2014)（Others）
大塚孝治 : “「テンソル力とエキゾチック核の構造進化」”,
原子核研究, 59 巻, pp86-100, (2014).
大塚孝治 : “「54 Ca で発見した新しい魔法数」”, Isotope
News, No.720, 4 月号, 2014 年.
Oral Presentations(International Conference etc.)
Shimoura S. (invited): “Nuclear responses via inelastic
scatterings of exotic nuclei”, Advances in Nuclear Structure at Extreme Conditions, Bormio, Italy, Feb. 19–22,
2014
Takaki M.(oral): “New type of spectroscopy via Heavy-Ion
Double Charge eXchange reaction”, Advances in Nuclear Structure at Extreme Conditions, Bormio, Italy,
Feb. 19–22, 2014
Michimasa S., Yanagisawa Y., Inafuku K., Aoi N., Elekes
Z., Fulop Zs., Ichikawa Y., Iwasa N., Kurita K.,
Kurokawa M., Machida T., Motobayashi T., Nakamura
T., Nakabayashi T., Notani M., Ong H.J., OnishiT., Otsu H., Sakurai H., Shinohara M., SumikamaT., Takeuchi S., Tanaka K., Togano Y., Yamada K.,
Yamaguchi M., Yoneda K. (oral): “Proton inelastic scattering on Island-of-inversion nuclei”, The 2nd
Conference on “Advances in Radioactive Isotope Science”(ARIS2014), Tokyo, Japan, June 1–6, 2014

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Kisamori K., Shimoura S., Assie M., Baba H., Baba T.,
Beaumel D., Dozono M., Fujii T., Fukuda N., Go S.,
Hammache F., Ideguchi E., Inabe N., Itoh M., Kameda
D., Kawase S., Kawabata T., Kobayashi M., Kondo Y.,
Kubo T., Kubota Y., Kurata-Nishimura M., S. Lee C.,
Maeda Y., Matsubara H., Michimasa S., Miki K., Miya
H., Nishi T., Noji S., Ota S., Sakaguchi S., Sakai H.,
Sasamoto Y., Sasano M., Sato H., Shimizu Y., Stolz A.,
Suzuki H., Takaki M., Takeda H., Takeuchi S., Tamii A.,
Tang L., Tokieda H., Tsumura M., Uesaka T., Yako K.,
Yanagisawa Y., Yokoyama R. (poster): “Missing-mass
Spectroscopy of the 4n System by Exothermic Doublecharge Exchange Reaction 4 He(8 He, 8 Be)4n”, The 2nd
Conference on “Advances in Radioactive Isotope Science”(ARIS2014), Tokyo, Japan, June 1–6, 2014
Yokoyama R., Ideguchi E., Simpson G., Tanaka Mn.,
Nishimura S., Doornenbal P., Sderstrm P.-A., LorussoG., Y. Xu Z., Wu J., Sumikama T., Aoi N., Baba H.,
Bello F., Brown F., Daido R., Fang Y., Fukuda N., Gey
G., Go S., Inabe N., Isobe T., Kameda D., Kobayashi
K., Kobayashi M., Komatsubara T., Kubo T., Kuti I., Li
Z., Matsushita M., Michimasa S., Moon C.B., Nishibata
H., Nishizuka I., Odahara A., Patel Z., Rice S., Sahin E.,
Sinclair L., Suzuki H., Takeda H., Taprogge J., Vajta Zs.,
Watanabe H., Yagi A. (oral): “Isomers in Pm isotopes
on the neutron-rich frontier of largely deformed Z ∼ 60
region”, at the 2nd Conference on Advances in Radioactive Isotope Science, Tokyo, Japan, June 1-6, 2014,
Kisamori K., Shimoura S., Michimasa S., Miya H., Assie
M., Baba H., Baba T., Beaumel D., Dozono M., Fujii
T., Fukuda N., Go S., Hammache F., Ideguchi E.,
Inabe N., Itoh M., Kameda D., Kawase S., KawabataT., Kobayashi M., Kondo Y., Kubo T., Kubota Y.,
Kurata-Nishimura M., S. Lee C., Maeda Y., Matsubara
H., Miki K., Nishi T., Noji S., Ota S., Sakaguchi S., Sakai
H., Sasamoto Y., Sasano M., Sato H., Shimizu Y., Stolz
A., Suzuki H., Takaki M., Takeda H., Takeuchi S., Tamii
A., Tang L., Tokieda H., Tsumura M., Uesaka T., YakoK., Yanagisawa Y., Yokoyama R. (oral): “Missin- mass
spectroscopy of the 4n system by exothermic doublecharge exchange reaction 4 He(8 He, 8 Be)4n”, at the 8thInternational Workshop on “Direct Reactions with Exotic Beams - DREB2014”, Darmstadt, Germany, June
30–July 4, 2014
Kisamori K., Sasano M., Uesaka T., Kikuchi Y. (oral):“Tetra-neutron study via four neutron decay of superheavy hydrogen 7 H” SAMURAI international collaboration workshop 2014, Sendai, Japan, September 8–9,
2014
Michimasa S. (oral): “Quadrupole Colletivity in Island-ofInversion Nuclei ”, The 3rd SUNFLOWER Workshop,
Tokyo, Japan, September 15–16, 2014
Matsushita M.(oral): “New Energy-Degrading Beamline
for Low-Energy Reaction Measurements of RI beam”,
The 3rd SUNFLOWER Workshop, Tokyo, Japan,- 521 -

September 15–16, 2014
Shimoura S.(invited): “Charge exchange reactions of RIbeams using SHARAQ spectrometer”, NUBA Conference Series-1: Nuclear Physics and Astrophysics in Antalya, Adrasan, Turkey, September 15–21, 2014
Dozono M. (oral) : “The (16 O,416 F) reaction as a novel
probe for studying the spin-dipole excitations in nuclei”,
Neutrino Nuclear Reponses for Neutrino Studies in Nuclei (NNR14), RCNP, Osaka University, Japan, Nov. 56, 2014
Shimoura S. (invited): “Nucleon transfer reactions at intermediate energy to exotic nuclei using inverse kinematics”, ECT* Workshop on ‘From nuclear structure
to particle-transfer reactions and back II’, Trento, Italy,
November 10–14, 2014
Michimasa M. (invited): “In-beam gamma spectroscopyusing direct reactions for probing shell evolution”,
Progress in nucler shell-model calculations in CNSRIKEN collaboration, Wako, Saitama, Japan, Nov. 26–
28, 2014
Kisamori K., Shimoura S., Assie M., Baba H., Baba T.,
Beaumel D., Dozono M., Fujii T., Fukuda N., Go S.,
Hammache F., Ideguchi E., Inabe N., Itoh M., Kameda
D., Kawase S., Kawabata T., Kobayashi M., Kondo Y.,
Kubo T., Kubota Y., Kurata-Nishimura M., Lee C.S.,
Maeda Y., Matsubara H., Michimasa S., Miki K., Miya
H., Nishi T., Noji S., Ota S., Sakaguchi S., Sakai H.,
Sasamoto Y., Sasano M., Sato H., Shimizu Y., Stolz A.,
Suzuki H., Takaki M., Takeda H., Takeuchi S., Tamii A.,
Tang L., Tokieda H., Tsumura M., Uesaka T., Yako K.,
Yanagisawa Y., Yokoyama R. (oral): “Study of tetraneutron system via the exothermic double-charge exchange reaction 4He(8He, 8Be)4n” International Workshop on “Critical Stability in Few-Body System”, Wako,
Saitama, Japan, January 26–30, 2015
Gunji T. for the ALICE Collaboration (oral): “Future upgrade and physics perspectives of the ALICE
TPC”, XXIV International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (QM2014), Darmstat, Germany, May 19 - 24, 2014
Gunji T. for the ALICE Collaboration (invited): “Dark
Photon searches in ALICE for the ALICE Collaboration”, International workshop on Dark Interactions:
Perspectives from Theory and Experiment, Brookhaven
National Laboratory, New York, USA, June 11-13, 2014,
Watanabe Y.(oral): “Measurements of di-electron production in Au+Au collisions at RHIC-PHENIX”, The 5th
Asian Triangle Heavy Ion Conference (ATHIC2014), Osaka, Japan, August 5-8, 2014
Hayashi S. on behalf of the ALICE Collaboration (poster):“Study of dielectron production in p-Pb collisions at√
sN N = 5.02 TeV using Transition Radiation Detector triggers with the ALICE detector”, XXIV International Conference on Ultrarelativistic Nucleus-Nucleus
Collisions (QM2014), Darmstat, Germany, May 19 - 24,

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Ⅶ. LIST OF PUBLICATIONS

2014
Hayashi S. on behalf of the ALICE Collaboration (oral):√“Dielectron measurement in p-Pb collisions at sNN =5.02 TeV with the ALICE detector”, The 5th Asian
Triangle Heavy Ion Conference (ATHIC2014), Osaka,
Japan, August 5-8, 2014
Hayashi S. on behalf of the ALICE Collaboration (oral):“Dielectrons production from heavy quark decays in√
p-Pb collisions at sNN = 5.02 TeV”, High Energy
Strong Interactions: A School for Young Asian Scientists, Wuhan, Chaina, September 22-26, 2014
Ota S., Tokieda T., Lee C.S., Watanabe Y.N., for CAT
collaboration (invited): “CNS Active Target (CAT) for
Missing Mass Spectroscopy with Intense Beams”, 27th
International Conference of the International Nuclear
Target Development Society (INTDS-2014), Tokyo,
Japan, Aug. 31 - Sep. 5, 2014
Ota S., Tokieda H., Lee C.S., Kojima R., Watanabe
Y.N., Corsi A., Dozono M., Gibelin J., Hashimoto T.,
Kawabata T., Kawase S., Kubono S., Kubota Y., Maeda
Y., Matsubara H., Matsuda Y., Michimasa S., Nakao T.,
Nishi T., Obertelli A., Otsu H., Santamaria C., Sasano
M., Takaki M., Tanaka Y., Leung T., Uesaka T., YakoK., Yamaguchi H., Zenihiro J., Takada E. (poster): ”Development of CNS Active Target for Deuteron Induced
Reactions with High Intensity Exotic Beam”, The 2nd
conference on “Advances in Radioactive Isotope Science” (ARIS2014), Tokyo, Japan, Jun. 1-6, 2014
LEE C. OTA S., TOKIEDA H., KOJIMA R., WATANABE Y., SAISEAU R., UESAKA T.(poster): “Property of THGEM in Low-Pressure Deuterium for a LowPressure Gaseous Active Target”, The 2nd conference on“Advances in Radioactive Isotope Science” (ARIS2014),
Tokyo, Japan, Jun. 1-6, 2014
Yamaguchi H. (invited): “Studying alpha-cluster structure using low-energy RI beam”, 3rd International
Workshop on State of the Art in Nuclear Cluster
Physics (SOTANCP3) KGU Kannai Media Center,
Kanto Gakuin University, Yokohama, Japan, May 2630, 2014
Yamaguchi H.(oral): “Proton resonance elastic scattering of 7Be at CRIB”, RIBF-ULIC mini workshop: ‘The
way to evaluate the inelastic channel in the proton resonance elastic scattering’, RIKEN Nishina Center, Wako,
Saitama, Japan, May 31, 2014,
Yamaguchi H.(invited): “Studies on Nuclear Astrophysics
and Exotic Structure at the Low-Energy RI beam Facility CRIB”, The 2nd Conference on Advances in Radioactive Isotope Science (ARIS2014) Ito International
Center, Tokyo, Japan, June 2-6, 2014
Kahl D.(poster): “30 S+alpha Resonant Elastic Scatteringwith an Active Target”, The 2nd Conference on Advances in Radioactive Isotope Science (ARIS2014) Ito
International Center, Tokyo, Japan, June 2-6, 2014
Yamaguchi H.(oral): “Studies on Nuclear Astrophysics

and Exotic Structure at the Low-Energy RI Beam Facility CRIB”, Sicily-East Asia Workshop for Low-energy
Nuclear Physics, Catania University, Ortygia island, Siracusa, July 28–31, 2014
Kahl D.(oral): “30 S+alpha Resonant Elastic Scatteringwith an Active Target”, Sicily-East Asia Workshop for
Low-energy Nuclear Physics, Catania University, Ortygia island, Siracusa, July 28–31, 2014
Yamaguchi H.(oral): “Search for cluster states by measurements of alpha resonant scattering”, The 10th RIBF Discussion ‘Cluster states probed by reaction experiments’,
Yukawa institute for theoretical physics, Kyoto Univ.,
Sep. 25, 2014
H. Yamaguchi (oral), “Recent status and technical aspects
of RI Beam separator CRIB”, Nuclear physics seminar
at RISP, Feb. 28, 2014, IBS, Daejeon, Korea.
Yamaguchi H.(invited): “Nuclear astrophysics, reaction,and structure studies at the low-energy RI beam separator CRIB”, The International Symposium on Physics
of Unstable Nuclei 2014 (ISPUN14) Hotel New World
Saigon, Ho Chi Minh City, Vietnam, November 3–8,
2014
Otsuka T. (invited): “Dual Fermi liquid, critical point and68Ni”, Workshop on “The structure of 68Ni: current
knowledge and open questions”, Leuven, Belgium, April
23-24, 2014
Otsuka T. (invited): “Shape evolution, shape coexistence
and shell evolution in exotic nuclei”, 11th INT. SPRINGSEMINAR ON NUCLEAR PHYSICS, Ischia, Italy, May
12-16, 2014
Otsuka T. (invited): “Shell model and nuclear shapes”,
French-US Theory Institute for Physics with Exotic
Nuclei (FUSTIPEN) Topical Meeting, GANIL, France,
July 19-20, 2014
Otsuka T. (invited): “Shapes of exotic nuclei and quantum liquid picture”, Fourth Workshop of the European
Gamma and Ancillary Detectors Network, GSI, Germany, July 23-25, 2014
Otsuka T. (invited): “Shapes of exotic nuclei and shell evolution”, Fifteenth International Symposium on Capture
Gamma-Ray Spectroscopy and Related Topics (CGS15),
Dresden, Germany, August 25-29, 2014
Otsuka T. (invited): “Dual quantum liquids and shell evolutions in exotic nuclei”, INTERNATIONAL SCHOOLOF NUCLEAR PHYSICS 36th Course, Erice, Italy,
September 16-24, 2014
Otsuka T. (invited): “Dual quantum liquids and shellevolution in exotic nuclei”, International Symposium on
Physics of Unstable Nuclei, Ho Chiming, Vietnam, November 2-8, 2014
Otsuka T. (invited): “Two-neutrino Double Beta Decay
from 48Ca calculated with sd and pf shells”, EMMI
Rapid Reaction Task Force on matrix elements of neutrinoless double beta decay, Darmstadt, Germany, November 10-21, 2014

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Shimizu N. (invited), Abe T., Honma M., Mizusaki T.,
Otsuka T., Togashi T., Tsunoda Y., Utsuno Y., andYoshida T.: “Frontier of nuclear shell-model calculations
and high performance computing”, Advances in Radioactive Isotope Science (ARIS2014), Univ. of Tokyo,
Tokyo, Japan, Jun. 05, 2014
Utsuno Y. (invited), Otsuka T., Tsunoda Y., Shimizu N.,
Honma M., Togashi T., Mizusaki T.: “Recent Advancesin shell evolution with shell-model calculations”, 2ndInternational Conference “Advances in Radioactive Isotope Science”, Tokyo, Japan, Jun. 2-6, 2014
Utsuno Y. (invited), Otsuka T., Shimizu N., Tsunoda Y.,
Honma M., Abe T., Mizusaki T., Togashi T. and Brown
B.A. : “Large-scale shell-model studies for exotic nuclei:
probing shell evolution”, International Conference “Nuclear Theory in the Supercomputing Era 2014 (NTSE2014)”, Khabarovsk, Russia, Jun. 23-27, 2014
Iwata Y. (invited) : “Present status of fission researchbased on TDDFT”, Symposium on Nuclear Data,
Hokkaido University, Japan, Nov 2014
Iwata Y. (invited) : “Nuclear matrix element of 48Ca”,
NNR14, RCNP, Osaka University, Japan, Nov 2014
Iwata Y. (Poster), Shimizu N., Utsuno Y., Honma M.,
Abe T., and Otsuka T. : “Large-scale shell model calculations for double beta decay of 48Ca”, ARIS 2014,
Tokyo, Japan, Jun. 2014
Iwata Y. : “Shape transition induced by rotation”, 3rdInternational Workshop on“ State of the Art in Nuclear
Cluster Physics ”(SOTANCP3), Yokohama, Japan, May
2014
Yoshida T. (Poster), Shimizu N., Abe T., Otsuka T. :“Cluster Structure of Be Isotopes based on Monte Carlo
Shell Model”, The 2nd Conference on “Advances in Radioactive Isotope Science” (ARIS2014), Tokyo, Japan.
Jun. 1-6, 2014
Yoshida T., Shimizu N., Abe T., and Otsuka T. : “Cluster structure of Be isotopes based on Monte Carlo shellmodel”, ICNT workshop “Physics of exotic nuclei: Theoretical advances and challenges”, RIKEN Wako Campus, Japan, Jun. 9-13, 2014
Togashi T., Shimizu N., Utsuno Y., Abe T. and Otsuka T.: “GPGPU Application to the Computation ofHamiltonian Matrix Elements between Non-orthogonal
Slater Determinants in the Monte Carlo Shell Model”, ,ICCS2014, Pullman Cairns International, Cairns, Australia, Jun. 11, 2014
Togashi T. (Poster), Shimizu N., Utsuno Y., Otsuka T.
and Honma M. : “Shell-model calculation of high-spinstates in neutron-rich Cr and Fe isotopes”, Advancesin Radioactive Isotope Science (ARIS2014), Univ. ofTokyo, Tokyo, Japan, Jun. 05, 2014
Yoshida T., Shimizu N., Abe T., Otsuka T. : “Appearance of alpha-cluster structure in Be isotopes basedon Monte Carlo shell model”, 3rd International Workshop on“ State of the Art in Nuclear Cluster Physics ”(SOTANCP3), KGU Kannai Media Center, Kanto
Gakuin University, Yokohama, Japan, May 26-30, 2014
Iwata Y. : “Large-scale shell model calculation project for
double-beta decay”, Workshop on “Progress in nuclear
shell-model calculations in CNS-RIKEN collaboration”,
RIKEN, Japan, Nov. 2014
Tsunoda N. (invited) : “Microscopic description ofneutron-rich nuclei from the nuclear force”, Progress innuclear shell-model calculation in CNS-RIKEN collaboration, RIKEN, Wako, Nov. 26-28, 2014
Utsuno Y. (invited) : “Exploring shell evolution withalphleet collaborations”, Workshop “Progress in nuclear
shell-model calculations in CNS-RIKEN collaboration”,
Wako, Japan, Nov. 26-28, 2014
Shimizu N. : “Overview of Alphleet collaboration projectand Monte Carlo shell model”, International workshop
on “Progress in nuclear shell-model calculations in CNSRIKEN collaboration”, RIKEN Nishina hall, Wako,
Japan, November 26, 2014
Shimizu N. :“Introduction to shell-model code,
KSHELL”, International workshop on “Progress in nuclear shell-model calculations in CNS-RIKEN collaboration”, RIKEN Nishina hall, Wako, Japan, November 27,
2014(Domestic Conference)
Lee C.S., Ota S., Tokieda H., Kojima R., Watanabe Y.,
and T. Uesaka: “重水素アクティブ標的の大強度重イオ
ンビーム照射に向けた開発”, JPS Spring meeting, Tokai
University, Japan, Mar. 27–30, 2014
Kawase S., Uesaka T., Shimoura S., Yako K., Ota
S., Michimasa S., Tokieda H., Miya H., Leung T.T.,
Kisamori K., Takaki M., Kubota Y., Lee C.S., YokoyamaR., Fujii T., Kobayashi M., Sasano M., Zenihiro J.,
Matsubara H., Dozono M., Lee J., Sakai H., Kubo
T., Yoshida K., Inabe N., Yanagisawa Y., Takeda H.,
Kusaka K., Fukuda N., Kameda D., Suzuki H., Kawahara T., Wakui T., Sakaguchi S., Noro T., Wakasa T.,
Yasuda J., Fukunaga T., Maeda Y., Kim W., Hwang S.,
Stepanyan S., Obertelli A., Galind-Uribarri A., PadillaRodal E., and Beaumel D.: “準弾性 AO(p,2p) 反応による窒素同位体の陽子一空孔状態の核分光”, JPS Spring
meeting, Tokai University, Japan, Mar. 27–30, 2014
Ota S., Corsi A., Dozono M., Garg U., Hashimoto T.,
Ito M., Kawabata T., Kawase S., Kojima R., Kubota
Y., Lee C.S., Maeda Y., Matta J., Matsuda Y., Michimasa S., Obertelli A., Otsu H., Patel D., SantamariaC., Sasano M., Takaki M., Terashima T., Tokieda H.,
Uesaka T., Yamaguchi H., Zenihiro J., and H307 collaboration, “重水素ガスアクティブ標的を用いた錫領域不安定核における巨大単極共鳴の測定計画”, JPS Spring
meeting, Tokai University, Japan, Mar. 27–30, 2014
Tokieda H., Ota S., Dozono M., Gunji T., Hamagaki H.,
Hashimoto T., Kawabata T., Kawase S., Kojima R.,
Kubono S., Kubota Y., Lee C.S., Maeda Y., Matsubara H., Michimasa S., Otsu H., Sako M., Uesaka T.,- 523 -

7

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Yamaguchi H., and Watanabe Y.: “重水素ガスアクティ
ブ標的の反跳粒子飛跡再構成と性能評価”, JPS Spring
meeting, Tokai University, Japan, Mar. 27–30, 2014
Yako K., “Study of nuclear matrix element of the doublebeta decay by charge-exchange reactions”, JPS Spring
meeting, Tokai University, Japan, Mar. 27–30, 2014
Kubota Y., Sasano M., Uesaka T., Dozono M., Itoh M.,
Kawase S., Kobayashi M., Lee C.S., Matsubara H., Miki
K., Miya H., Ota S., Sekiguchi K., Shima T., TaguchiT., Tamii A., Tang T.L., Tokieda H., Wakasa T., Wakui
T., Yasuda J., and Zenihiro J.: “不安定核研究のための高位置分解能ファイバーシンチ中性子検出器の開発”, JPS
Spring meeting, Tokai University, Japan, Mar. 27–30,
2014
Gunji. T for the ALICE Collaboration, “R&D status of
the ALICE GEM-TPC upgrade”, JPS Spring meeting,Tokai University, Japan, Mar. 27–30, 2014
Yukawa K., Gunji T., Hamagaki H., Terasaki K., “GEMTPC におけるイオンバックフローの空間電荷依存性の研究”, JPS Spring meeting, Tokai University, Japan, Mar.
27–30, 2014
Kisamori K., Shimoura S., Assie M., Baba H., Baba T.,
Beaumel D., Dozono M., Fujii T., Fukuda N., Go S.,
Hammache F., Ideguchi E., Inabe N., Itoh M., Kameda
D., Kawase S., Kawabata T., Kobayashi M., Kondo Y.,
Kubo T., Kubota Y., Kurata-Nishimura M., Lee C.S.,
Maeda Y., Matsubara H., Michimasa S., Miki K., Miya
H., Nishi T., Noji S., Ota S., Sakaguchi S., Sakai H.,
Sasamoto Y., Sasano M., Sato H., Shimizu Y., Stolz A.,
Suzuki H., Takaki M., Takeda H., Takeuchi S., Tamii
A., Tang L., Tokieda H., Tsumura M., Uesaka T., YakoK., Yanagisawa Y., Yokoyama R. (poster): “Study oftetra-neutron system by the exothermic double-charge
exchange reaction 4 He(8 He, 8 Be)4n”, 実験と観測で解き明かす中性子星の核物質第三回研究会, Atagawa, Shizuoka,
Japan, September 23-25, 2014
Shimoura S.(invited): “New energy degraded beam
project at RIBF OEDO project ”, Fourth Joint Meetingof the Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan, Waikoloa,
Hawaii, USA, October 7–11, 2014
Michimasa S.(invited): “RI-induced reaction studies by
new energy-degrading beam line, OEDO”, Fourth Joint
Meeting of the Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan,
Waikoloa, Hawaii, USA, October 7–11, 2014
Dozono M.(oral) : “The parity-transfer reaction (16 O,16 F)
for studies of pionic 0− mode”, 4th Joint Meeting of
the APS Division of Nuclear Physics and the PhysicalSociety of Japan, Waikoloa, Hawaii, USA, Oct. 7-11,
2014
Kisamori K., Shimoura S., Assie M., Baba H., Baba T.,
Beaumel D., Dozono M., Fujii T., Fukuda N., Go S.,
Hammache F., Ideguchi E., Inabe N., Itoh M., Kameda
D., Kawase S., Kawabata T., Kobayashi M., Kondo Y.,- 524 -

Kubo T., Kubota Y., Kurata-Nishimura M., Lee C.S.,
Maeda Y., Matsubara H., Michimasa S., Miki K., Miya
H., Nishi T., Noji S., Ota S., Sakaguchi S., Sakai H.,
Sasamoto Y., Sasano M., Sato H., Shimizu Y., Stolz A.,
Suzuki H., Takaki M., Takeda H., Takeuchi S., Tamii
A., Tang L., Tokieda H., Tsumura M., Uesaka T., YakoK., Yanagisawa Y., Yokoyama R. (oral): “Tetra-neutron
system studied by exothermic double-charge exchange
reaction 4 He(8 He, 8 Be)4n”, The 4th Joint Meeting of the
Nuclear Physics Devisions of the APS and JPS, Hawaii,
USA, October 7–11, 2014
Kobayashi M., Yako K., Shimoura S., Dozono M., Kawase
S., Kisamori K., Kubota Y., Lee C.S., Michimasa S.,
Miya H., Ota S., Sakai H., Sasano M., and Takaki M.
(oral): “Spin-isospin response of neutron-rich nuclei 8 He
via (p, n) reaction in inverse kinematics”, Fourth Joint
Meeting of the Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan(Hawaii2014), Waikoloa, Hawaii, US, Oct. 7–11, 2014,
Miya H., Shimoura S., Kisamori K., Baba H., Baba T.,
Dozono M., Fukuda N., Fujii T., Go S., Ideguchi E.,
Inabe N., Ito M., Kameda D., Kawabata T., Kawase
S., Kikuchi Y., Kubo T., Kubota Y., Kobayashi M.,
Kondo Y., Lee C.S., Maeda Y., Matsubara H., Miki K.,
Michimasa S., Nishi T., Nishimura M., Ota S., Sakaguchi
S., Sakai H., Sasano M., Sato H., Shimizu Y., Suzuki H.,
Takaki M., Takeda H., Takeuchi S., Tamii A., Tokieda
H., Tsumura M., Uesaka T., Yanagisawa Y., YakoK., Yokoyama R., Yoshida K., Assie M., Beaumel D.,
Fariouz H., and Stolz A.: ”Missing mass spectroscopyof 4 H via exothermic charge exchange reaction (8 He,
8Liγ)”, The 4th Joint Meeting of the Nuclear Physics
Devisions of the APS and JPS, Hawaii, USA, October
7–11, 2014
Lee C.S., Ota S., Aramaki Y., Saiseau R., Tokieda H.,
and Watanabe Y.: ”Development of a dual-gain multiplication in CNS Active Target for high-intensity heavyion beam injection”, The 4th Joint Meeting of the Nuclear Physics Devisions of the APS and JPS, Hawaii,
USA, October 7–11, 2014
Ota S.(oral): ”CNS Active Target for deuteron induced reactions with high intensity beams”, The 4th Joint Meeting of the Nuclear Physics Devisions of the APS and
JPS, Hawaii, USA, October 7–11, 2014
Imai N., Mukai M., Cederkall J., Aghai H., Golubev P.,
Johansson H., Kahl D., Kurcewics J., Teranishi T.,
and Watanabe Y.: ”Small spectroscopic factors of lowlying positive parity states in 31 Mg”, The 4th Joint
Meeting of the Nuclear Physics Devisions of the APS
and JPS, Hawaii, USA, October 7–11, 2014
Gunji T.(invited): “Experimental upgrades at RHIC and
LHC”, JPS-DNP at Hawaii2014 Workshop on ”Quark
Gluon Plasma and Future Directions in Heavy Ion
Physics at RHIC and LHC”, Hawaii 2014, Hawaii, USA,
October 7–11

8

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Gunji T. (oral): “LHC-ALICE 実 験 用 MPGD を 用 い た
TPC 検出器開発の現状”, MicroPattern Gas Detector 研究会, 東北大学, Dec. 19 - 20, 2014
Yukawa K.(oral): “GEM と MICROMEGAS におけるイオ
ンバックフローの研究”, MicroPattern Gas Detector 研究会, 東北大学, Dec. 19 - 20, 2014
Gunji T.(poster): “Future Upgrade and Physics Perspectives of the LHC-ALICE Experiment”, Hadron Physics
Symposium, Nagoya University, Japan, April 17-19,
2014
Watanabe Y.(oral): “Measurements of di-electron produc√tion in Au+Au collisions at sN N = 200 GeV by RHICPHENIX using Hadron Blind Detector”, 4th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan, Hawaii, USA, Oct. 7 – 11, 2014
Hayashi S. on behalf of the ALICE Collaboration (oral):“Dielectrons from Charm and Bottom meson decays in√
p-Pb collisions at sNN = 5.02 TeV measured with the
ALICE detector”, Fourth Joint Meeting of the Nuclear
Physics Divisions of the American Physical Society and
The Phsical Society of Japan, Hawaii, USA, Octorber
7-11
Hayshi S.(invited): “Review of Quark Matter 2014(Heavy
Flavor)”, Heavy Ion Pub and Heavy Ion Cafe 合同研究会, Nagoya, Japan, June 6
Hayashi S. (invited): ”LHC での p-Pb 衝突における粒子相関”, Heavy Ion Pub, Osaka, Japan, December 5
Sekiguchi Y. for ALICE collaboration (oral): “Long range√
correlation in p-Pb collisions at sN N = 5.02 TeV with
the ALICE detector”, at 4th Joint Meeting of the APS
Division of Nuclear Physics and the Physical Society ofJapan, Waikoloa, Hawaii, USA, Oct. 7-11, 2014
Terasaki K., Hamagaki H., Gunji T., Yamaguchi Y.(oral):“Performance Evaluation of the COBRA GEM for the
Application of the TPC”, at 4th Joint Meeting of the
APS Division of Nuclear Physics and the Physical Society of Japan, Waikoloa, Hawaii, USA, Oct. 7-11, 2014
Otsuka T. (invited): “What can we learn from large-scale
MCSM calculations?”, Fourth Joint Meeting of the Nuclear Physics Divisions of the American Physical Society
and The Physical Society of Japan, Waikoloa, USA, Oct.
(2014).
Utsuno Y. (invited): “Shells and shapes in exotic nuclei”,
Fourth Joint Meeting of the Nuclear Physics Divisions of
the American Physical Society and The Physical Societyof Japan, Waikoloa, USA, Oct. (2014).
Shimizu N., Utsuno Y., Togashi T., Otsuka T., and Honma
M. : “Shell-model description of E1 excitation”, Fourth
Joint Meeting of the Nuclear Physics Divisions of theAmerican Physical Society and The Physical Society ofJapan, Waikoloa, USA, Oct. (2014).
Iwata T., Shimizu N., Utsuno Y., Honma M., Abe T., andOtsuka T. : “Large-scale shell model calculations for
two-neutrino double-beta decay of 48Ca”, Fourth Joint
Meeting of the Nuclear Physics Divisions of the Ameri-- 525 -

can Physical Society and The Physical Society of Japan,
Waikoloa, USA, Oct. (2014).
Yoshida T., Shimizu N., Abe T., and Otsuka T. : “Structure of Be isotopes based on Monte Carlo shell model”,
Fourth Joint Meeting of the Nuclear Physics Divisions of
the American Physical Society and The Physical Societyof Japan, Waikoloa, USA, Oct. (2014).
Tsunoda N.: “Neutron-rich nuclei from the nuclear force a
new Many-body perturbation theory with 3N force andits first application”, Fourth Joint Meeting of the Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan, Waikoloa, USA,
Oct. (2014).
Togashi T., Shimizu N., Utsuno Y., Otsuka T. and Honma
M. : “Large-scale shell-model calculation of unnaturalparity high-spin states in neutron-rich Cr and Fe isotopes”, Fourth Joint Meeting of the Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan, Waikoloa, USA, Oct. (2014).
富樫智章, 清水則孝, 吉田亨, 宇都野穣, 阿部喬, 大塚孝治 : “モンテカルロ殻模型計算のマルチ GPGPU への適用と開発状況”, 第 6 回「学際計算科学による新たな知の発見・統合・創出」シンポジウム.
(Colloquium) Y. Iwata : “Fission Dynamics of A=240 Nuclei Based on Time-Dependent Density Functional Calculations”, Colloquium at Tokyo Institute of Technology, Sep. (2014).
下浦 享: 「エキゾチック原子核の世界」, Konan University,
Kobe, Japan, June 9–11, July 8–9, 2014

9

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

Niigata University
Publications[Journal]（Original Papers） *Subject to Peer Review
Matsuo M., Hinohara N., Sato K., Matsuyanagi K.,
Nakatsukasa T., and Yoshida K.: “Quadrupole shape
dynamics from the viewpoint of a theory of large amplitude collective motion”, Phys. Scr. 89, 054020(6)(2014). ＊Zhang Y., Matsuo M., and Meng J.: “Asymptotic formof neutron Cooper pairs in weakly bound nuclei”, Phys.
Rev. C 90, 034313 (2014). ＊Takechi M., Suzuki S., Nishimura D., Fukuda M., OhtsuboT., Nagashima M., Suzuki T., Yamaguchi T., Ozawa A.,
Moriguchi T., Ohishi H., Sumikama T., Geissel H., Aoi
N., Chen Rui-Jiu, Fang De-Qing, Fukuda N., Fukuoka
S., Furuki H., Inabe N., Ishibashi Y., Itoh T., Izumikawa
T., Kameda D., Kubo T., Lantz M., Lee C. S., Ma
Yu-Gang, Matsuta K., Mihara M., Momota S., Nagae
D., Nishikiori R., Niwa T., Ohnishi T., Okumura K.,
Ohtake M., Ogura T., Sakurai H., Sato K., Shimbara Y.,
Suzuki H., Takeda H., Takeuchi S., Tanaka K., Tanaka
M., Uenishi H., Winkler M., Yanagisawa Y., WatanabeS., Minomo K., Tagami S., Shimada M., Kimura M.,
Matsumoto T., Shimizu Y. R., and Yahiro M.: “Evidence of halo structure in Mg-37 observed via reaction
cross sections and intruder orbitals beyond the island of
inversion”, Phys. Rev. C 90, 061305 (2014). ＊Fan G. W., Fukuda M., Nishimura D., Cai X. L., Fukuda
S., Hachiuma I., Ichikawa C., Izumikawa T., Kanazawa
M., Kitagawa A., Kuboki T., Lantz M., Mihara M.,
Nagashima M., Namihira K., Ohkuma Y., Ohtsubo T.,
Ren Zhongzhou, Sato S., Shen Z. Q., Sugiyama M.,
Suzuki S., Suzuki T., Takechi M., Yamaguchi T., Xu
B. J., and Xu W.: “Structure of Li-8 from a reaction
cross-section measurement”, Phys. Rev. C 90, 044321(2014). ＊Moriguchi T., Ozawa A., Ishimoto S., Abe Y., Fukuda
M., Hachiuma I., Ishibashi Y., Ito Y., Kuboki T., Lantz
M., Nagae D., Namihira K., Nishimura D., Ohtsubo T.,
Ooishi H., Suda T., Suzuki H., Suzuki T., Takechi M.,
Tanaka K., and Yamaguchi T.: “Density distribution of
Be-14 from reaction cross-section measurements”, Nucl.
Phys. A 929, 83–93 (2014). ＊Muto S., Stone N. J., Bingham C. R., Stone J. R., Walker
P. M., Audi G., Gaulard C., Koester U., Nikolov J.,
Nishimura K., Ohtsubo T., Podolyak Z., Risegari L.,
Simpson G. S., Veskovic M., and Walters W. B.: “Magnetic properties of Hf-177 and Hf-180 in the strongcoupling deformed model”, Phys. Rev. C 89, 044309(2014). ＊Ozawa A., Moriguchi T., Ohtsubo T., Aoi N., Fang D. Q.,
Fukuda N., Fukuda M., Geissel H., Hachiuma I., InabeN., Ishibashi Y., Ishimoto S., Ito Y., Izumikawa T.,- 526 -

Kameda D., Kubo T., Kuboki T., Kusaka K., Lantz M.,
Ma Y. G., Mihara M., Miyashita Y., Momota S., Nagae
D., Namihira K., Nishimura D., Ooishi H., Ohkuma
Y., Ohnishi T., Ohtake M., Ogawa K., Shimbara Y.,
Suda T., Sumikama T., Suzuki H., Suzuki S., SuzukiT., Takechi M., Takeda H., Tanaka K., Watanabe R.,
Winkler M., Yamaguchi T., Yanagisawa Y., Yasuda Y.,
and Yoshinaga K.: “Charge-changing cross sections of
Ne-30, Na-32,Na-33 with a proton target”, Phys. Rev.
C 89, 044602 (2014). ＊Estradé A., Kanungo R., Horiuchi W., Ameil F., Atkinson
J., Ayyad Y., Cortina-Gil D., Dillmann I., Evdokimov
A., Farinon F., Geissel, H., Guastalla G., Janik, R.,
Kimura M., Knöbel R., Kurcewicz J., Litvinov Yu. A.,
Marta M., Mostazo M., Mukha I., Nociforo C., Ong H.
J., Pietri S., Prochazka A., Scheidenberger C., Sitar B.,
Strmen P., Suzuki Y., Takechi M., Tanaka J., Tanihata
I., Terashima S., Vargas J., Weick H., and Winfield J.
S.: “Proton Radii of B12–17 Define a Thick Neutron
Surface in B17”, Phys. Rev. Lett. 113, 132501 (2014).
＊
Crawford H. L., Fallon P., Macchiavelli A. O., Clark R.
M., Brown B. A., Tostevin J. A., Bazin D., Aoi N.,
Doornenbal P., Matsushita M., Scheit H., SteppenbeckD., Takeuchi S., Baba H., Campbell C. M., Cromaz M.,
Ideguchi E., Kobayashi N., Kondo Y., Lee G., Lee I. Y.,
Lee J., Li K., Michimasa S., Motobayashi T., Nakamura
T., Ota S., Paschalis S., Petri M., Sako T., Sakurai
H., Shimoura, S., Takechi M., Togano Y., Wang, H.,
and Yoneda K.: “Shell and shape evolution at N = 28:
The Mg40 ground state”, Phys. Rev. C 89, 041303(2014). ＊Watanabe S., Minomo K., Shimada M., Tagami S.,
Kimura M., Takechi M., Fukuda M., Nishimura D.,
Suzuki T., Matsumoto T., Shimizu Y. R., and Yahiro
M.: “Ground-state properties of neutron-rich Mg isotopes”, Phys. Rev. C 89, 044610 (2014). ＊Nakamura T., Kobayashi N., Kondo Y., Satou Y., Tostevin
J. A., Utsuno Y., Aoi N., Baba H., Fukuda N., Gibelin
J., Inabe N., Ishihara M., Kameda D., Kubo T.,
Motobayashi T., Ohnishi T., Orr, N. A., Otsu H., OtsukaT., Sakurai H., Sumikama T., Takeda H., Takeshita E.,
Takechi M., Takeuchi S., Togano Y., and Yoneda K.:“Deformation-Driven p-Wave Halos at the Drip Line:
Ne31”, Phys. Rev. Lett. 112, 142501 (2014). ＊Caballero-Folch R., Domingo-Pardo C., Cortès G.,
Taı́n J. L., Agramunt J., Algora A., Ameil F.,
Ayyad Y., Benlliure J., Bowry M., Calviño F.,
Cano-Ott D., Davinson T., Dillmann I., Estrade A.,
Evdokimov A., Faestermann T., Farinon F., Galaviz D.,
Garcı́a-Rı́os A., Geissel H., Gelletly W., Gernhäuser R.,
Gómez-Hornillos M. B., Guerrero C., Heil M., Hinke
C., Knöbel R., Kojouharov I., Kurcewicz J., Kurz N.,
Litvinov Y., Maier L., Marganiec J., Marta M., Martı́nezT., Montes F., Mukha I., Napoli D. R., Nociforo C.,

1

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Paradela C., Pietri S., Podolyák Zs., Prochazka A., RiceS., Riego A., Rubio, B., Schaﬀner H., ScheidenbergerC., Smithr K., Sokol E., Steiger K., Sun B., Takechi
M., Testov D., Weick H., Wilson E., Winﬁeld J. S.,
Wood R., Woods P. J., and Yeremin A.: “β-decay and
β-delayed Neutron Emission Measurements at GSI-FRS
Beyond N = 126, for r-process Nucleosynthesis’, Nucl.
Data Sheets 120, 81–83 (2014). ＊Shibata Y., Matsuzaki T., Abe K., Fujita Y., Goto J., ItohT., Kikukawa N., Nagashima M., Nakamura Y., Ogura
T., Ohtsubo T., Ohya S., Sakai T., Sera D., Suzuki S.,
Takeda K., Yajima A., and Yoshikawa T.: “Observationof Muonic X-rays of Cosmic-Ray Muons Stopped in Al
and Fe Targets”, J. Phys. Soc. Jpn. 84, 034301 (2015).
＊
Yoshida K.: “Proton-neutron pairing vibrations in N = Z
nuclei: Precursory soft mode of isoscalar pairing condensation”, Phys. Rev. C 90, 031303(R) (2014). ＊Even J., Yakushev A., Düllmann Ch. E., Haba H., Asai M.,
Sato T. K., Brand H., Nitto A. Di, Eichler R., Fan F.
L., Hartmann W., Huang M., Jäger E., Kaji D., Kanaya
J., Kaneya Y., Khuyagbaatar J., Kindler B., Kratz J.
V., Krier J., Kudou Y., Kurz N., Lommel B., MiyashitaS., Morimoto K., Morita K., Murakami M., Nagame
Y., Nitsche H., Ooe K., Qin Z., Schädel M., Steiner J.,
Sumita T., Takeyama M., Tanaka K., Toyoshima A.,
Tsukada K., Türler A., Usoltsev I., Wakabayashi Y.,
Wang Y., Wiehl N., and Yamaki S.: “Synthesis and detection of a seaborgium carbonyl complex”, Science 345,
1491–1493 (2014). ＊Yokokita T., Kasamatsu Y., Ooe K., Yoshimura T.,
Takahashi N., Komori Y., and Shinohara A.: “Solvent
extraction of Mo(V) and Mo(VI) from hydrochloric acidinto Aliquat 336 chloroform solution”, J. Radioanal.
Nucl. Chem. 301, 751–756 (2014). ＊Haba H., Huang M., Kaji D., Kanaya J., Kudou Y.,
Morimoto K., Morita K., Murakami M., Ozeki K.,
Sakai R., Sumita T., Wakabayashi Y., Yoneda A.,
Kasamatsu Y., Kikutani Y., Komori Y., Nakamura
K., Shinohara A., Kikunaga H., Kudo H., Nishio K.,
Toyoshima A., and Tsukada K.: “Production of 262 Db
in the 248 Cm(19 F, 5n)262 Db reaction and decay properties of 262 Db and 258 Lr”, Phys. Rev. C 89, 024618(11)(2014). ＊Murakami M., Haba H., Goto S., Kanaya J., and Kudo
H.: “Production corss section of niobium and tantalum
isotopes in proton-induced reactions on nat Zr and nat Hf
up to 14 MeV”, Appl. Radiat. Isot. 90, 149–157 (2014).
＊
Khandaker M. U., Haba H., Murakami M., Otuka N.,
and Kassim H. A.: “Deuteron-induced activation crosssections on natural copper up to 24 MeV”, J. Radioanal.
Nucl. Chem. 302, 759–764 (2014). ＊Fan G. W., Fukuda M., Nishimura D., Cai X. L., Fukuda
S., Hachiuma I., Ichikawa C., Izumikawa T., Kanazawa

M., Kitagawa A., Kuboki T., Lantz M., Mihara M.,
Nagashima M., Namihira K., Ohkuma Y., Ohtsubo T.,
Ren Z. Z., Sato S., Sheng Z. Q., Sugiyama M., SuzukiS., Takechi M., Yamaguchi T., and Xu W.: “Density
distribution of Li-8 and B-8 and capture reaction at low
energy”, Phys. Rev. C 91, 014614 (2015). ＊Takechi M., Suzuki S., Nishimura D., Fukuda M., OhtsuboT., Nagashima M., Suzuki T., Yamaguchi T., Ozawa A.,
Moriguchi T., Ohishi H., Sumikama T., Geissel H., Aoi
N., Chen R. J., Fang D. Q., Fukuda N., Fukuoka S.,
Furuki H., Inabe N., Ishibashi Y., Itoh T., Izumikawa
T., Kameda D., Kubo T., Lantz M., Lee C. S., Ma
Y. G, Matsuta K., Mihara M., Momota S., Nagae
D., Nishikiori R., Niwa T., Ohnishi T., Okumura K.,
Ohtake M., Ogura T., Sakurai H., Sato K., Shimbara Y.,
Suzuki H., Takeda H., Takeuchi S., Tanaka K., Tanaka
M., Uenishi H., Winkler M., Yanagisawa Y., WatanabeS., Minomo K., Tagami S., Shimada M., Kimura M.,
Matsumoto T., Shimizu Y. R., and Yahiro M.: “Evidence of halo structure in Mg-37 observed via reaction
cross sections and intruder orbitals beyond the island of
inversion”, Phys. Rev. C 90, 061305 (2014). ＊（Review）
菖蒲川由郷, 後藤淳: “チーム毘沙門の南相馬市支援活動記録”, 新潟県医師会報, 771, (2014).
[Book・Proceedings]（Original Papers） *Subject to Peer Review
Ooe K., Attallah M. F., Asai M., Goto N., Gupta N. S.,
Haba H., Huang M., Kanaya J., Kaneya Y., KasamatsuY., Kitatsuji Y., Kitayama Y., Koga K., Komori— Y.,
Koyama T., Kratz J. V., Lerum H. V., Miyashita S.,
Oshimi Y., Pershina V., Sato D., Sato T. K., Shigekawa
Y., Shinohara A., Tanaka A., Toyoshima A., Tsukada
K., Tsuto S., Yokokita T., Yokoyama A., Omtvedt J.
P., Nagame Y., and Schädel M.: “Development of a
new continuous dissolution apparatus with a hydrophobic membrane for superheavy element chemistry”, J. Radioanal. Nucl. Chem., 303, 1317–1320 (2015). ＊Oral Presentations(International Conference etc.)
Yoshida K.: “Low-lying Gamow-Teller Excitations andBeta-Decay Properties of Neutron-Rich Zr Nuclei”, The
second international Conference on Advances in Radioactive Isotope Science, (University of Tokyo), Tokyo,
Japan, Jun. (2014).
Yoshida K.: “Skyrme-EDF for charge-changing excitation
modes”, ICNT Workshop “Physicics of exotic nuclei:
Theoretical advances and challenges”, (RIKEN), Wako,
Japan, Jun. (2014).
Yoshida K.: “Gamow-Teller excitations and beta-decay
properties of deformed neutron-rich Zr isotopes”, Nuclear Structure 2014, (TRIUMF, the University of
British Columbia), Vancouver, Canada, Jun. (2014).
Yoshida K.: “Giant multi-pole resonances in rare-earth- 527 -

2

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅶ. LIST OF PUBLICATIONS

nuclei with shape changes”, International Workshop on
Nuclear Science and Simulation in fundamental and applied researchesv, (Ton Duc Thang University), Ho Chi
Minh City, Vietnam, Oct. (2014).
Yoshida K.: “Proton-neutron pairing vibrations in N =Z nuclei”, The International Symposium on Physics of
Unstable Nuclei 2014, Ho Chi Minh City, Vietnam, Nov.
(2014).
Takechi M., Suzuki S., Nishimura D., Fukuda M., OhtsuboT., Nagashima M., Suzuki T., Yamaguchi T., Ozawa
A., Moriguchi T., Ooishi H., Sumikawa T., Geissel H.,
Ishihara M., Aoi N., Chen R. J., Fang D. Q., Fukuda
N., Fukuoka S., Furuki H., Inabe N., Ishibashi Y., Ito
T., Izumikawa T., Kameda D., Kubo T., Lee C. S., Lantz
M., MA Yu-Gang, Matsuta K., Mihara M., Momota S.,
Nagae D., Nishikiori R., Niwa T., Ohnishi T., Okumura
K., Ogura T., Sakurai H., Sato K., Shimbara Y., Suzuki
H., Takeda H., Takeuchi S., Tanaka K., Uenishi H.,
Winkler M., Yanagisawa Y., Watanabe S., Minomo K.,
Tagami S., Shimada M., Kimura M., Matsumoto T.,
Shimizu Y., and Yahiro M.: “Deformed halo nuclei observed thorough the reaction cross sections measurements for Ne and Mg isotopes to the vicinity of neutrondrip line”, DREB2014 Direct Reactions with Exotic
Beams, Darmstadt, Germany, Jun. (2014).
Murakami M., Goto S., Murayama H., Kojima T., Kaji
D., Morimoto K., Haba H., Kudou Y., Sumita T., SakaiR., Yoneda A., Morita K., Kasamatsu Y., Kikunaga H.,
Sato T., and Kudo H.: “Excitation functions for production of rutherfordium isotopes in the 248 Cm +18 O
reaction”, 17th Radiochemical Conferencec, Mariánské
Lázně, Czech Republic, May (2014).
Murakami M., Haba H., Goto S., and Kudo H.: “Production cross sections of Nb and Ta isotopes in the (p, x) and(d, x) reactions on nat Zr and nat Hf”, 17th Radiochemical Conferencec, Mariánské Lázně, Czech Republic, May(2014).
Kudo H., Goto S., and Murakami M. (Poster): “Gasphase chemistry of the volatile chloride compound of Hf
isotopes”, 17th Radiochemical Conferencec, Mariánské
Lázně, Czech Republic, May (2014).
Murakami M.: “Cross section measurements of useful radiotracers for application studies at RIKEN”, Seminarat International Atomic Energy Agency, (IAEA), Vienna, Austria, May (2014).
(Domestic Conference)
Goto J., Amaya Y., Hirayama S., Shiiya T., Shobugawa Y.,
Kawano Y., Izumukawa T., Uematsu K., Katsuragi Y.,
Takahashi T., Yoshida H., and Naito M. (Oral): “Development of a car-borne directional gamma-ray survey
system”, 日本原子力学会 2015 年春の年会, (日本原子力学会), 茨城大学 (日立キャンパス), 3 月 (2015).
Yoshida K. (Oral): “中性子ドリップ線近傍核における集団
モード”, 九大研究会「中性子過剰領域における弱束縛系の物理」, (九州大学), 九州大学 (福岡), 3 月 (2015).

- 528 -

Yoshida K. (Oral): “Proton-neutron pairing vibrations in
N = Z nuclei”, 日本物理学会 第 70 回年次大会, (日本物理学会), 早稲田大学 (東京), 3 月 (2015).
Murakami M., Haba H., Huang M., Goto S., and Kudo H.
(Oral): “nat Zr(d, x), nat Hf(d, x) 反応による Nb，Ta 同位体の励起関数測定”, 第 58 回放射化学討論会, (日本放射化学会), 名古屋大学 (東山キャンパス), 9 月 (2014).
Sato D., Murakami M., Haba H., Kikunaga H., Ooe K.,
Goto S., and Kudo H. (Oral): “Aliquat 336 を 用 い た
Nb，Ta のフッ化水素酸溶液からの溶媒抽出挙動”, 第 58回放射化学討論会, (日本放射化学会), 名古屋大学 (東山キャンパス), 9 月 (2014).
Tsuto S., Murakami M., Ooe K., Goto S., Sato D., Goto
N., Nagaoka T., Haba H., Toyoshima A., Kudo H.,
Koyama T., Motoyama R., Komori Y., Kitayama Y.,
and Fukuda Y. (Oral): “Db の化学実験に向けた 5 族元素
Nb，Ta のオンライン逆相クロマトグラフィー”, 第 58 回
放射化学討論会, (日本放射化学会), 名古屋大学 (東山キャンパス), 9 月 (2014).
Tanaka A., Ooe K., Kikunaga H., Goto S., and Kudo H.
(Poster): “104 番元素 Rf の同族元素 Zr、Hf のキレート
配位子を用いた溶媒抽出挙動の研究”, 第 58 回放射化学討論会, (日本放射化学会), 名古屋大学 (東山キャンパス), 9
月 (2014).
Goto N., Ooe K., Murakami M., Goto S., Tsukada
K., Toyoshima A., Asai M., Sato T. K., Miyashita
S., Kaneya Y., Kitayama Y., Haba H., Komori Y.,
and Kudo H. (Poster): “Sg の同族元素 Mo, W のシュウ酸水溶液からのイオン対抽出挙動”, 第 58 回放射化学討論会, (日本放射化学会), 名古屋大学 (東山キャンパス), 9 月(2014).
Asai T., Goto S., Ooe K., and Kudo H. (Poster): “BiCl3の等温ガスクロマトグラフィ挙動に関する研究”, 第 58 回
放射化学討論会, (日本放射化学会), 名古屋大学 (東山キャンパス), 9 月 (2014).
Murakami M., Haba H., Shibata S., and Kudo H. (Poster):“nat Hf(α, x) 反応の励起関数測定”, 第 58 回放射化学討論会, (日本放射化学会), 名古屋大学 (東山キャンパス), 9 月(2014).
Oshimi Y., Goto S., Ooe K., and Kudo H. (Poster): “Oﬀline 実験における Zr，Hf 塩化物の等温くガスクロマトグ
ラフィ挙動”, 第 58 回放射化学討論会, (日本放射化学会),
名古屋大学 (東山キャンパス), 9 月 (2014).
Tamura N., Nishio K., Hirose K., Nishinaka I., Makii
H., Kimura A., Ota S., Andreyev A., Vermeulen M.,
Gilespire S., Bentley M., Nagayama T., Ooe K., GotoS., and Kudo H. (Poster): “マイナーアクチノイドの中性
子誘起核反応断面積の測定法の開発”, 第 58 回放射化学討論会, (日本放射化学会), 名古屋大学 (東山キャンパス), 9
月 (2014).

3

Ⅶ. LIST OF PUBLICATIONSRIKEN Accel. Prog. Rep. 48 (2015)

Radioactive nuclear beam group
IPNS (Institute for Particle and Nuclear Studies)
KEK (High Energy Accelerator Research Organization)of multinucleon transfer reactions of 136 Xe + 198 Pt for
production of exotic heavy nuclei”, EPJ Web of Conference 66 (2014) 03044,*

Publications

Oral Presentations(International Conference etc.)
Watanabe Y.X., Hirayama Y., Imai N., Ishiyama H., Jeong
S.C., Miyatake H., Oyaizu M., Kimura S., Mukai M.,
Choi S.H., Kim Y.H., Song J.S., Clement E., De FranceG., Navin A., Rejmund M., Schmitt C., Pollarolo G.,
Corradi L., Fioretto E., Montanari D., Niikura M.,
Suzuki D., Nishibata H., Takatsu J., “Study of multinucleon transfer reactions of 136 Xe+ 198 Pt for production of
exotic nuclei”, VI International Conference FUSION14
February, 2014, New Delhi, India[Journal](Original Papers) *Subject to Peer Review
Hirayama Y., Mukai M., Watanabe Y.X., Imai N.,
Ishiyama H., Jeong S.C., Miyatake H., Oyaizu M.,
Matsuo Y., Sonoda T., Wada M., “Ionization cross section measurements for autoionizing states of iridium andrhenium”, J. Phys. B: At. Mol. Opt. Phys. 47 (2014)
075201, *Ishiyama H., Jeong S.C., Watanabe Y.X., Hirayama Y.,
Imai N., Hiroari M., Oyaizu M., Katayama I., Osa A.,
Otokawa Y., Matsuda M., Nishio K., Makii H., Sato
T.K.., Kuwata N., Kawamura J., Nakao A., Ueno H.,
Kim Y.H., Kimura S., Mukai M., “Nanoscale diﬀusion
tracing by radioactive 8 Li tracer”, Jpn. J. Appl. Phys
53 (2014) 110303, *Das S.K., Ishiyama H., Watanabe Y.X., Miyatake H.,
Hirayama Y., Jeong S.C., Yamaguchi K., “Energy resolution and gas gain of an active-target type Gas counterof GEM-MSTPC”, J. Bangla. Aca. Sci. 37 (2014) 139144, *Ishiyama H., Jeong S.C., Watanabe Y.X., Hirayama Y.,
Imai N., Hiroari M., Oyaizu M., Katayama I., Osa A.,
Otokawa Y., Matsuda M., Nishio K., Makii H., Sato
T.K.., Kuwata N., Kawamura J., Nakao A., Ueno H.,
Kim Y.H., Kimura S., Mukai M., “In situ lithium diﬀusion measurement in solid ionic conductors using shortlived radiotracer beam of 8 Li”, Nucl. Instrum. Method
B XX (2014) XXXXX, *Mukai M., Hirayama Y., Jeong S.C., Imai N., Ishiyama
H., Miyatake H., Oyaizu M., Watanabe Y.X., Kim Y.H.,“In-gas-cell laser ion source for KEK isotope separation
system”, Rev. Sci. Instrum. 85 (2014) 02B906, *[Book • Proceedings ](Original Papers) *Subject to Peer Review
Hirayama Y., Jeong S.C., Watanabe Y.X., Imai N.,
Ishiyama H., Miyatake H., Oyaizu M., Kim Y.H., Mukai
M., Sonoda T., Wada M., Huyse M., Kudryavtsev Yu.,
Van Duppen P., “Present Status of KEK Isotope Separation System”, EPJ Web of Conference 66 (2014) 11017,*
Hirayama Y., Watanabe Y.X., Imai N., Ishiyama H., Jeong
S.C., Miyatake H., Oyaizu M., Kim Y.H., Mukai M.,
Kimura S., “β-deacy spectroscopy of r-process nuclei
with N = 126 at KISS”, AIP Conf. Proc. 1594 (2014)
380-387,*
Kim Y.H., Watanabe Y.X., Hirayama Y., Imai N.,
Ishiyama H., Jeong S.C., Miyatake H., Oyaizu M.,
Kimura S., Mukai M., Choi S.H., Song J.S., Clement
E., De France G., Navin A., Rejmund M., Schmitt C.,
Pollarolo G., Corradi L., Fioretto E., Montanari D.,
Niikura M., Suzuki D., Nishibata H., Takatsu J., “Study- 529 -

1

VIII. LIST OF PREPRINTSⅧ. LIST OF PREPRINTS

RIKEN Accel. Prog. Rep. 48 (2015)

List of Preprints (April 2014 - March 2015)
RIKEN NC-NP
132

Quadrupole shape dynamics in view from a theory of large amplitude collective motion

M. Matsuo, N. Hinohara, K. Sato, K.
Matsuyanagi, T. Nakatsukasa, K. Yoshida133

Isospin-invariant Skyrme energy-density-functional approach with axial symmetry

J.A. Sheikh, N. Hinohara, J. Dobaczewski,
T. Nakatsukasa, W. Nazarewicz, K. Sato

134

Systematic investigation of low-lying dipole modes using the canonical-basis time-dependent
Haratree-Fock-Bogoliubov theory

S. Ebata, T. Nakatsukasa, T. Inakura

135

Mean-field analysis of ground state and low-lying electric dipole strength in 22C

T. Inakura, W. Horiuchi, Y. Suzuki, T.
Nakatsukasa

136

Thermal pairing and giant dipole resonance in highly excited nuclei

N.D. Dang

137

Hidden pseudospin and spin symmetries and their origins in atomic nuclei

H. Liang, J. Meng et al.

138

Pairing effect in thermal shape fluctuation model on the width of giant dipole resonance

A.K. Rhine Kumar, P. Arumugam, N. Dinh
Dang

139

Viscosity: From air to hot nuclei

N.D. Dang

140

Possible presence and properties of multi chiral pair-bands in odd-odd nuclei with the same
intrinsic

I. Hamamoto

141

Oblate deformation of light neutron-rich even-even nuclei

I. Hamamoto

142

Pigmy resonance in monopole response of neutron-rich Ni isotopes ?

I. Hamamoto, H. Sagawa

143

Energy and mass-number dependence of hadron-nucleus total reaction cross sections

A. Kohama, K. Iida, K. Oyamatsu

144

Microscopic analysis of fusion hindrance in heavy systems

K. Washiyama

145

Repulsive aspects of pairing correlation in nuclear fusion reaction

S. Ebata, T. Nakatsukasa

146

Finite amplitude method in linear response TDDFT calculations

T. Nakatsukasa

147

Mean-field calculation based on proton-neutron mixed energy density functionals

K. Sato, J. Dobaczewski, T. Nakatsukasa,
W. Satula

148

Multiple period states of the superfluid fermi gas in an optical lattice

S. Yoon, F. Dalfovo, T. Nakatsukasa, G.
Watanabe

149

Hidden pseudospin and spin symmetries and their origins in atomic nuclei

H. Liang, J. Meng, S.G. Zhou

150

Three-dimensional mesh calculations for covariant density functional theory

Y. Tanimura, K. Hagino, H. Z. Liang

RIKEN NC- AC
Not Applicable

RIKEN MP88

Entanglement Entropy of de Sitter Space α-Vacua

N. Iizuka, T. Noumi, N. Ogawa

89

Dynamical breaking of shift-symmetry and super-Planckian inflation

A. Mazumdar, T. Noumi, and M. Yamaguchi

90

Towards U(N|M) knot invariant from ABJM theory

B. Eynard, T. Kimura

91

Electric field quench in QdS/CFT

K. Hashimoto, S. Kinoshita, K. Murata, andT. Oka- 531 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅷ. LIST OF PREPRINTS

92

Bulk Angular Momentum and Hall Viscosity in Chiral Superconductors

A. Shitade and T. Kimura

93

Turbulent Meson Condensation as Quark Deconfinement

K. Hashimoto, S. Kinoshita, K. Murata, andT. Oka94

Duality and integrability of a supermatrix model with an external source

T. Kimura

95

Entropic destruction of heavy quarkonium in non-Abelian plasma from the holographic
correspondence

K. Hashimoto, D.E. Kharzeev

96

Effective field theory for spacetime symmetry breaking

Y. Hidaka, T. Noumi, and G. Shiu

97

Is cosmological constant screened in Liouville gravity with matter?

T. Inami, Y. Koyama, Y. Nakayama, M.
Suzuki98

Meson turbulence at quark deconfinement from AdS/CFT

K. Hashimoto, S. Kinoshita, K. Murata, andT. Oka99

Electromagnetic instability in holographic QCD

K. Hashimoto, A. Sonoda, T. Oka

100

Holographic heavy quark symmetry

K. Hashimoto, N. Ogawa, and Y. Yamaguchi

101$h^0 ¥to c ¥bar{c}$ as a test case for quark flavor violation in the MSSM

A. Bartl, H. Eberl, E. Ginina, K. Hidaka, W.
Majerotto

102

Higgs boson decay to charm pair at full one-loop level in the MSSM with flavour violation

H. Eberl, A. Bartl, E. Ginina, K. Hidaka, W.
Majerotto

103

Ramond-Ramond Couplings of D-branes

K. Hashimoto, S. Sugishita, S. Terashima

104

Possibility of QCD ferromagnetism at high density

K. Hashimoto

105

Holographic Entanglement and Causal Shadow in Time-Dependent Janus Black HoleY. Nakaguchi, N. Ogawa, T. Ugajin

106

Conditionally valid uncertainty relations

K. Fujikawa

107

Quantum Discord, CHSH Inequality and Hidden Variables -- Critical reassessment of
hidden-variables

K. Fujikawa

108

Aharonov-Bohm effect and geometric phases -- Exact and approximate topology

K. Fujikawa

109

Eigenvalues of the Breit equation

Y. Yoshio, H. Kasari

110

Linking loops in ABJM and refined theory

T. Kimura

111

Relativistic hydrodynamics from quantum field theory on the basis of the generalized Gibbs
ensemble method

T. Hayata, Y. Hidaka, M. Hongo, T. Noumi

RIKEN QHP
146

Di-jet asymmetric momentum transported by QGP fluid

Y. Tachibana, T. Hirano

147

Sine-Square Deformation and its Relevance to String Theory

T. Tada148

Renormalized O(N) model at next-to-leading order of the 1/N expansion: effects of the Landau
pole

G. Fejos, A. Patkos, Zs. Szep

149

Entanglement Entropy of de Sitter Space α-Vacua

N. Iizuka, T. Noumi, N. Ogawa

150

Restricted phase-space approximation in real-time stochastic quantization

R. Anzaki, K. Fukushima, Y. Hidaka, and T.
Oka

151

Production and Elliptic Flow of Dileptons and Photons in the semi-Quark Gluon Plasma

152

Adjoint QCD on $R^3 ¥times S^1$ with twisted fermionic boundary conditions

C. Gale, Y. Hidaka, S. Jeon, S. Lin, J.-F.
Paquet, R.D. Pisarski, D. Satow, B.
Schenke, V.V. Skokov, G. Vujanovic
T. Misumi, T. Kanazawa

153

Polarization of Direct Photons from Gluon Anisotropy in Ultrarelativistic Heavy Ion Collisions

G. Baym and T. Hatsuda,

154

Nonlinear electromagnetic response in quark-gluon plasma

D. Satow- 532 -

Ⅷ. LIST OF PREPRINTS

RIKEN Accel. Prog. Rep. 48 (2015)

155

Production of dileptons and photons in the semi-quark gluon plasma

Y. Hidaka, S. Lin, R.D. Pisarski, D. Satow156

Real-time Feynman path integral with Picard--Lefschetz theory and its applications to quantum
tunneling

Y. Tanizaki, T. Koike

157

Stressed Cooper pairing in dense QCD: effective Lagrangian and random matrix theory

T. Kanazawa, T. Wettig

158

QCD sum rules for magnetically induced mixing between ¥eta_c and J/¥psi

S. Cho, K. Hattori, S.H. Lee, K. Morita andS. Ozaki

159

Dispersion relations of Nambu-Goldstone modes at finite temperature and density

T. Hayata, Y. Hidaka

160

Inhomogeneous Polyakov loop induced by inhomogeneous chiral condensates

T. Hayata, A. Yamamoto

161

Fluctuation induced first order phase transition in U(n)xU(n) models using chiral invariant
expansion of FRG

G. Fejos

162

Medium-Heavy Nuclei from Nucleon-Nucleon Interactions in Lattice QCD

T. Inoue, T. Hatsuda et al. (HAL QCD
Collaboration)

163

Magnetic susceptibility of strongly interacting matter with $2+1$ quark flavors

K. Kamikado, T. Kanazawa

164

Many-body composite bosons from the viewpoint of functional renormalization

Y. Tanizaki

165

On the origin of the narrow peak and the isospin symmetry breaking of the X(3872)

S. Takeuchi, K. Shimizu, M. Takizawa

166

Lefschetz-thimble techniques for path integral of zero-dimensional O(n) sigma models

Y. Tanizaki

167

Renormalization of the 2PI-Hartree approximation in a broken phase with nonzero superflow

G. Fejos

168

Quasi-instantons in QCD with chiral symmetry restoration

T. Kanazawa, N. Yamamoto

169

Asymptotically free lattice gauge theory in five dimensions

T. Kanazawa, A. Yamamoto

170

Complex Langevin simulation of quantum vortex nucleation in the Bose-Einstein condensate

T. Hayata, A. Yamamoto

171

Effective field theory for spacetime symmetry breaking

Y. Hidaka, T. Noumi, G. Shiu

172

Charmonium Spectroscopy in Strong Magnetic Fields by QCD Sum Rules: (I) S-Wave Ground
StatesS. Cho, K. Hattori, S.H. Lee, K. Morita, andS. Ozaki

173

Coupled channel approach to strangeness S = -2 baryon-baryon interactions in Lattice QCD

174

Structure of Lefschetz thimbles in simple fermionic systems

K. Sasaki, S. Aoki, T. Doi, T. Hatsuda, Y.
Ikeda, T. Inoue, N. Ishii, K. Murano, H.
Nemura (HAL QCD Collaboration)
T. Kanazawa, Y. Tanizaki

175

Holographic heavy quark symmetry

K. Hashimoto, N. Ogawa, Y. Yamaguchi

176

Holographic Entanglement and Causal Shadow in Time-Dependent Janus Black HoleY. Nakaguchi, N. Ogawa, T. Ugajin

178

Tenth-Order Electron Anomalous Magnetic Moment: Contribution of Diagrams without Closed
Lepton Loops

T. Aoyama, M. Hayakawa, T. Kinoshita, andM. Nio179

Omega-Omega interaction from 2+1 flavor lattice QCD

180

Relativistic hydrodynamics from quantum field theory on the basis of the generalized Gibbs
ensemble method

M. Yamada, K. Sasaki, S. Aoki, T. Doi, T.
Hatsuda, Y. Ikeda, T. Inoue, N. Ishii, K.
Murano and H. Nemura (HAL QCD
Collaboration)
T. Hayata, Y. Hidaka, M. Hongo, T. Noumi

181

From quantum to classical dynamics: Dynamic crossover in the relativistic $O(N)$ model at finite D. Mesterhazy, Y. Tanizaki

182

Jarzynski-type equalities in gambling: role of information in capital growth

Y. Hirono, Y. Hidaka

183

Evading the sign problem through Lefschetz-thimble path integral

Y. Tanizaki, H. Nishimura, K. Kashiwa

184

Accurate Determination of Reference Scales for Wilson Gauge Action from Yang{Mills GradientFlow

M. Asakawa, T. Hatsuda, T. Iritani, E. Itou,
M. Kitazawa, H. Suzuki

185

Phonons, Pions and Quasi-Long-Range Order in Spatially Modulated Chiral Condensates

Y. Hidaka, K. Kamikado, T. Kanazawa and T.
Noumi

186

Infinite circumference limit of conformal field theory

N. Ishibashi, T. Tada

- 533 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅷ. LIST OF PREPRINTS

CNS-REP93

CNS Annual Report 2013

T. Gunji, S.Ota, Y. Kishi

Nishina Center Preprint server (not including Partner Institution) can be found at
http://nishina-preprints.riken.jp/- 534 -

IX. LIST OF SYMPOSIA& WORKSHOPSⅨ. LIST OF SYMPOSIA & WORKSHOPS

RIKEN Accel. Prog. Rep. 48 (2015)

List of Symposia & Workshops (April 2014 - March 2015)
RNC
1

The Approach to Equilibrium in Strongly Interacting Matter
http://www.bnl.gov/aesim2014/index.php

BNL

Apr. 2-4

2

4rd Joint ISIS/RIKEN Muon Facility Development Workshop（ISIS/UK）

RAL

Apr. 4

3

The 3rd EURICA workshop
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1429

RIBF Conference
Hall

Apr.

10

4

RIBF Discussion Plus! -Island of Inversion
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1462

RIBF Conference
Hall

Apr.

25

5

The 3rd International Workshop on “State of the Art in Nuclear Cluster Physics” (SOTANCP3)
http://kguramo.kanto-gakuin.ac.jp/sotancp3/

KGU Kannai Media
CenterMay 26-30

6ICNT workshop "Physics of exotic nuclei: Theoretical advances and challenges"
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1450

RIKEN Main
Research Bldg.

Jun. 9

7

PALIS strategy meeting 2014

RIBF ConferenceHall

Jun. 98

One-day intensive workshop on “di-neutron and alpha-cluster correlations in exotic nuclei”
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1565

RIBF Bldg. 203

Jul. 109

The 9th RIBF Discussion meeting on the spin-isospin excitations in neutron rich nuclei
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1553

Okouchi Hall

Jul. 3110

RIKEN BNL Research Center Workshop: Thermal Protons & Dilepton in Heavy-Ion Collisions
http://www.bnl.gov/tpd2014/

BNL

Aug. 20-22

11

HET-RBRC Symposium: Creutz Fest 2014
-A Celebration of the Career and Accomplishments of Michael Creutzhttp://www.bnl.gov/creutzfest/

BNL

Sep. 4-5

12

SAMURAI International Collaboration Workshop 2014
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1593

Tohoku U.

Sep. 8-9

13

BigRIPS analysis workshop
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1562

RIBF Conference Hall

Sep. 11

14

The 3rd SUNFLOWER Workshop
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1560

U. TokyoSep. 15-16

15

The 10th RIBF discussion meeting on Cluster states probed by reaction experiments
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1577

Kyoto U.

Sep. 25

16

Advances and perspectives in computational nuclear physics
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1534

Hilton Waikoloa
Village

Oct. 6

17

The 3rd Japan-Korea PHENIX Collaboration Meeting
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1683

Okouchi Hall

Nov. 27-28

18

The 2nd RIBF Discussion Plus! -basic course of mean field theory
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1722

Nishina Hall

Dec. 24

19

Workshop for development of beam line detectors with high rate capabilities
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1745

RIBF ConferenceHall

Jan. 19

21

Workshop on Multi-Hadron and Nonnlocal Matrix Elements in Lattice QCD
https://indico.bnl.gov/conferenceDisplay.py?confId=934

BNL

Feb. 5-922

理研研究会『これからの弦理論 ～ 橋本研 closing 研究会 ～』http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1774

Okouchi Hall

Feb. 21-22- 535 -

RIKEN Accel. Prog. Rep. 48 (2015)
23

Ⅸ. LIST OF SYMPOSIA & WORKSHOPS

The 11th RIBF Discussion on Heavy-ion reaction and multi-nucleon transfer
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1754

U. TsukubaMar. 2CNS
1Advances in Radioactive Isotope Science (Jointly organized by the RIKEN Nishina Center and the CNS)
https://ribf.riken.jp/ARIS2014/index.html

U. TokyoJune 1-6

2

The first Sicily-East Asia Workshop for Low-energy Nuclear Physics
https://agenda.infn.it/conferenceDisplay.py?confId=8300

Sicily, Italy

July 28 - 31

3

Progress in nuclear shell-model calculations in CNS-RIKEN collaboration
http://indico.cns.s.u-tokyo.ac.jp/conferenceDisplay.py?confId=180

Nishina Hall,
RIBF ConferenceHall

Nov. 26-28

4

第一回放射線によるイメージングの展望
http://indico.cns.s.u-tokyo.ac.jp/conferenceDisplay.py?confId=195

U. TokyoNov. 295

第二回放射線によるイメージングの展望
http://indico.cns.s.u-tokyo.ac.jp/conferenceDisplay.py?confId=204

U. TokyoJan. 24

RCNP

Aug. 7-8KEK
1「宇宙核物理実験の現状と将来」研究会- 536 -

X. LIST OF SEMINARS

Ⅹ. LIST OF SEMINARSRIKEN Accel. Prog. Rep. 48 (2015)

List of Seminars (April 2014 - March 2015)
Nuclear Physics Monthly Colloquium
1

Yasuhiro Okada (KEK),
Sachio Komamiya (U. Tokyo)& Kaoru Yokoya (KEK)International Linear Collider: From Design to Reality
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1651

Nov. 102

Koji Hashimoto (RNC)

Quark and superstring
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1711

Dec. 26

RIBF Nuclear Physics Seminar
1

Takehito Hayakawa (JAEA)

Nuclear physics for nuclear security and nonproliferation
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1488

Apr. 222

Newcomers to Nishina Centerin 2014

New-Comers Seminar in 2014
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1504

May 14

3

Zhengyu Xu(RNC/U. Hong Kong)

β-Decay properties in the vicinity of 78Ni and their implications on nuclear shell structure far
off the b-stability line
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1505

May 30

4

Yuma Kikuchi (RNC)

Two-neutron correlations in the ground and excited states of 6He
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1545

Jul. 8

5

Shinya Wanajo(RIKEN iTHES)

Origin of the r-process elements
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1546

Jul. 15

6

Giuseppe Lorusso (RNC)

Beta-decay half-lives of N~82 nuclei on the r-process path
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1618

Sep. 30

7

Aiko Takamine(Aoyama Gakuin U.)

Measurement of the hyperfine structure constant for laser-cooled Be-11 ions
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1639

Oct. 28

8

Karl-Ludwig Kratz (U. Mainz)

One-day Workshop Program “Recent progress on r-process and nucleosynthesis”
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1650

Nov. 25

9

Wataru Horiuchi(Hokkaido U.)

Correlated basis approach to nuclear five- and six-body problems
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1688

Nov. 25

10

Jean-Michel Daugas (CEA)
et al.

Workshop on "Progress in nuclear shell-model calculations in CNS-RIKEN collaboration"
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1684

Nov.
26-28

11

Kathrin Wimmer(U. Tokyo/CNS/RIKEN)

CNS & Nuclear Physics Seminar :In-beam gamma-ray spectroscopy with GRETINA at the NSCL
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1698

Dec. 1

12

Shuichiro Ebata (Hokkaido U.)

Developments of the Canonical-basis Time-dependent Hartree-Fock-Bogoliubov Theory
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1729

Jan. 13

13

Nobuaki Imai (CNS)

Low-energy nuclear physics program at CNS 201
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1735

Jan. 20

14

Shinsho Oryu
(Tokyo U. of Sci.)

A Possibility of the Long Range Nuclear Potential by the NNp Three Body Approach and thePion-Deuteron Scattering Length
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1769

Feb. 10

15

Yutaka Watanabe (KEK, IPNS)

Present status of KEK isotope separation system (KISS)
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1747

Feb. 17

16

Makoto Ito (Kansai U.)

Studies of the reaction size with the method of the scattering radius
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1748

Feb. 24

17

Nodoka Yamanaka(RIKEN iTHES)

Nuclear electric dipole moment of 3-body systems in the Gaussian expansion method
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1770

Mar. 3- 537 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅹ. LIST OF SEMINARS

18John L. Wood
(Georgia Inst. of Tech.)Coexistence in Nuclei
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1777

Mar. 1019

Takeyasu Ito (LANL)

Development of neutron electric dipole moment experiments at Los Alamos
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1791

Mar. 13

20

Tatsushi Shima (RCNP)GLOBAL - ultra-low background experiment on the Earth's surface
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1782

Mar. 17

21

Wenlong Zhang (CAS)

ADANES: accelarator driven advance nuclear energy system
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1813

Mar. 27

22

Lei Yang (IMP)Development of high flux neutron source and ADANES
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1814

Mar. 27

Lecture Series on Nuclear Physics
not held in FY2014

Special Seminar
not held in FY2014

Seminar by Each Laboratory
Theoretical Research Division
1

Daisuke Sato
(RIKEN Low Temperature
Physics Lab.)

Strangeness Nuclear Physics Seminar:
2 次元ヘリウム 3 の基底状態

Apr. 18

2

Shunji Matsuura (McGil U.)

Math Phys Seminar:
Charged quantum entanglement

Apr. 21

3

Vojtech Krejcirik (RNC)

QHP Seminar:
Model-independent form factor relations at large $N_c$

Apr. 21

4

Akihisa Kohama (RNC)

TNP Internal Seminar:
Deformed nuclei in the black-sphere approximation
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1496

Apr. 22

5

Noriaki Ogawa (RNC)

QHP Seminar: Applications of AdS/CFT Correspondence to Real Physics

Apr. 28

6

Xiang Liu (Lanzhou U.)

QHP Seminar:
Interpretation of some exotic hadrons via the initial single chiral particle emission mechanism

May 12

7

Shinya Wanajo (RIKEN iTHES)& Yuto Teraki (RIKEN ABBLab.)ABB & TNP Joint Group Seminar: The r-process and nuclear physics
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1503

May 198

Yuma Kikuchi (RNC)

ABB & TNP Joint Group Seminar:
The r-process and nuclear physics

May 20

9

Kazuki Maeda (RNC)

QHP Seminar:
Orthogonal polynomials and solutions to the discrete Toda lattice

May 26

10

Sho Ozaki (KEK)

QHP Seminar:
QCD vacuum and hadron properties in strong magnetic fields

Jun. 2- 538 -

Ⅹ. LIST OF SEMINARSRIKEN Accel. Prog. Rep. 48 (2015)

11

Kazuya Mameda (U. Tokyo)

QHP Seminar:
QCD theta-vacua from the chial limit to the quenched limit

Jun. 912

Daisuke Takahashi (RIKEN)

Math Phys Seminar:
南部ゴールドストーンモードの分類と数え上げ：ボゴリューボフ理論による定式化

Jun. 13

13

Takashi Nakatsukasa (RNC)

TNP Internal Seminar:
Constraint or cranking?

Jun. 30

14

Yukinao Akamatsu (KMI)

QHP Seminar:
Heavy quark master equations in the Lindblad form

Jun. 30

15

Takahiro Nishi (U. Tokyo)

QHP Seminar:
Deeply bound-pionic atom and partial restoration of chiral symmetry in nucler medium

Jul. 1016

Masahiro Nozaki (YITP)

Math Phys Seminar:
Quantum Entanglement of Local Operators
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1568

Jul. 11

17

Pablo Morales (U. Tokyo)

QHP Seminar:
Spontaneous symmetry breaking and particle production in curved spaces

Jul. 14

18

Koukei Washiyama (RNC)

TNP Internal Seminar:
Microscopic analysis of fusion hindrance in heavy systems
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1570

Jul. 15

19

Pablo Soler Gomis(Hong Kong U. of Sci. & Tech.)Math Phys Seminar:U(1) portals into hidden sectors
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1574

Jul. 18

20

Toshiyuki Gogami (Kyoto U.)

Strangeness Nuclear Physics Seminar:
Spectroscopic research of ¥Lambda hypernuclei with high quality electron beam at Jefferson
Lab

Jul. 18

21

Yuma Kikuchi (RNC)

ABB & TNP Joint Group Seminar:
Search for exotic n-n correlations in weakly-bound nuclei
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1572

Jul. 28

22

Don Warren(North Carolina State U.)

ABB & TNP Joint Group Seminar: Cosmic-Ray Acceleration and Photon Production during theAfterglow Phase of Gamma-ray Bursts
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1572

Jul. 28

23

Alexander Karpov (FLNR)

Nuclear Theory Seminar:
Superheavy nuclei: Which regions of nuclear map are accessible in nearest future?
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1573

Jul. 28

24

Takahiro Sasaki (U. Tokyo)

QHP Seminar:
Studying the QCD phase diagram with PNJL type effective model

Jul. 28

25

Shin Nakamura (Chuo U.)

Strangeness Nuclear Physics Seminar:
AdS/CFT 対応を用いた非平衡統計物理学への挑戦

Aug. 126

Pengwei Zhao (Kyoto U.)

Nuclear Theory Seminar:
Novel Nuclear Structure from Covariant Density Functional
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1606

Sep. 127

Masako Bando (Inst.
Fundamental Sci., NPO Sci.
Edu. Exchange: EINSTEIN）

放射線の生物影響の統一的考察: 動物から植物まで
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1614

Sep. 1028

Di-Lun Yang
(National Taiwan U.)

Math Phys Seminar:
Electromagnetic-induced Effects in Strongly Coupled Plasmas
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1620

Sep. 1229

Daisuke Satow (RIKEN)QHP Seminar:
Nonlinear Electromagnetic Response in Quark-Gluon Plasma

Sep. 1730

Sho Nagao (Tohoku U.)

Strangeness Nuclear Physics Seminar:
Spectroscopy of electro-produced hypernuclei at Mainz Microtron
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1626

Sep. 29

31

Yoshitomo Kamiya(RIKEN iTHES/CMT Lab.)QHP Seminar:
Magnetic Vortex Crystals in Frustrated Mott Insulator

Oct. 15

32

Tomoya Takiwaki(RIKEN ABB Lab.)ABB-TNP Joing Lunch Time Seminar:
Impact of electron capture rate and equation of state on the supernovae explosions
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1640

Oct. 20- 539 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅹ. LIST OF SEMINARS

33

Hajime Togashi (RNC)

ABB-TNP Joing Lunch Time Seminar:
Supernova equation of state with the cluster variational method
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1640

Oct. 20

34

Koichiro Asahi (Tokyo Tech.)

Pioneer project seminar :Search for a Permanent Electric Dipole Moment in Diamagnetic Atom 129Xe
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1645

Oct. 31

35

Guido Cossu (KEK)

QHP Seminar:
Magnetic Vortex Crystals in Frustrated Mott Insulator

Nov. 436

Akira Shimizu (U. Tokyo)

Math Phys Seminar:
Pure state quantum statistical mechanics
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1676

Nov. 1037

Alexander G. Magner(Inst. for Nuclear Research)

Nuclear Theory Seminar:
Semiclassical approaches to the macroscopic and microscopic nuclear dynamics
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1677

Nov. 14

38

Hyun-Chul Kim (Inha U.)

Strangeness Nuclear Physics Seminar:
The charge and spin structure of the nucleon and the pion

Nov. 14

39

Seiji Terashima (YITP)

Math Phys Seminar:
A Localization Computation in Confining Phase
http://ribf.riken.jp/MP/Seminar_semina.html

Nov. 17

40

Sahin Kaya Ozdemir(Washington U., St. Louis)

QHP Seminar:Controlling light at the exceptional points with whispering gallery microresonators

Nov. 1741

Nguyen Dinh Dang (RNC)

TNP Internal Seminar: Recent achievements in the study of highly excited nuclei: Thermal
pairing and giant dipole resonance in not rotating nuclei
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1692

Nov. 18

42

Gordon Baym
(U. Illinois – Urbana
Champaign)

QHP Seminar:
The Superfluid Mass Density and the Landau Criterion for Superfluidity
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1691

Nov. 20

43

Masaki Murata(Academy of Sci. of the Czech
Republic)

Math Phys Seminar:
境界のある共形場理論による透過率

Nov. 28

44

Kantaro Ohmori (U. Tokyo)

Math Phys Seminar:
Anomaly polynomial of general 6d SCFTs

Dec. 15

45

Yuji Tachikawa (U. Tokyo)

QHP Seminar:
Magnetic discrete gauge field in the confining vacua and the supersymmetric index

Dec. 2246

Hiromichi Nishimura(Bielefeld U.)

QHP Seminar:
Complex saddle points in finite-density QCD

Dec. 2247

Yu Maezawa (Bielefeld U.)

QHP Seminar:
Thermal modification of in-medium mesons from screening properties on latticeDec. 22

48

Koichi Sato (RNC)

TNP Internal Seminar:
Proton-neutron mixing calculation with isospin breaking term

Dec. 24

49

Kazunobu Maruyoshi(Imperial College London)

Math Phys Seminar:
4d N=1 SCFTs from M5-branes

Jan. 1650

Masafumi Fukuma (Kyoto U.)

QHP Seminar:
Entropic formulation of (relativistic) continuum mechanics and a causal completion ofrelativistic fluid mechanics

Jan. 19

51

Akinori Tanaka (Osaka U.)

Math Phys Seminar:
RP2 超共形指数とミラー対称性

Jan. 26

52

Shu Lin (RBRC)QHP Seminar:
Axial charge dynamics in quark gluon plasma

Feb. 553

Annop Wongwathanarat(RIKEN ABB Lab.)ABB-TNP Joint Lunch Time Seminar:
Supernova 1987A: neutrino-driven explosions in three dimensions and light curves
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1768

Feb. 954

Tohru Motobayashi (RNC)

ABB-TNP Joint Lunch Time Seminar: First access to the r-process path
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1768

Feb. 9- 540 -

Ⅹ. LIST OF SEMINARSRIKEN Accel. Prog. Rep. 48 (2015)

55

Osamu Morimatsu (KEK)

QHP Seminar:
Dynamic Critical Exponent from One and Two-Particle Irreducible 1/N Expansion of Effectiveand Microscopic Theories

Feb. 956

Sanjin Benić (U. Tokyo)

QHP Seminar:
An effective model for the QCD phase transitions at finite baryon density

Mar. 257

Hironori Hoshino (Nagoya U.)

Math Phys Seminar:
ホログラフィーによる非平衡密度物質の有限温度の解析

Mar. 958

Koji Hashimoto (RNC)

The Associate Chief Scientist Final Report
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1794

Mar. 1059

Luca Delacretaz (Stanford U.)

Math Phys Seminar:
Wess-Zumino terms in theories with spontaneously broken space-time symmetries

Mar. 26

60

Hiroshi Isono(National Tsing Hua U.)

Math Phys Seminar:
Note on the self-duality of gauge fields in topologically nontrivial spacetime

Mar. 30

Sub Nuclear System Research Division
1

Kaustubh Agashe(U. Maryland)

Joint HET/YITP/RIKEN Seminar:
Using energy-peaks to measure particle (new and old) masses

Apr. 92Adam Ritz (U. Victoria)

High-Energy Physics & RIKEN Theory Seminar:
Light dark matter and neutrino beams

Apr. 163

Adam Bzdak (RBRC)

RIKEN/BNL Lunch Time Talk

Apr. 17

4

Hong Liu (MIT)

Nuclear Physics & RIKEN Theory Seminar:
Renormalized entanglement entropy and RG flows

Apr. 18

5

Michael Endres (MIT)High-Energy Physics & RIKEN Theory Seminar:
Signal/noise enhancement strategies for stochastically estimated correlation functions

Apr. 23

6

Roy Lacey (Stony Brook U.)

RIKEN/BNL Lunch Time Talk

Apr. 24

7

Thomas Mehen (Duke U.)

Nuclear Physics & RIKEN Theory Seminar:
Fragmentation Functions and Fragmenting Jet Functions in Quarkonium Production

Apr. 25

8

Daniel Litim (U. Sussex)

Nuclear Physics & RIKEN Theory Seminar:
Aspects of functional renormalization

May 2

9

Toru Kojo (U. Illinois –Urbana-Champaign)

Nuclear Physics & RIKEN Theory Seminar:
The quark mass gap in strong magnetic fields

May 9

10

Shu Lin (RBRC)

RIKEN/BNL Lunch Time Talk:
On the axial charge dynamics at strong couplingMay 15

11

J.D. Vergados (U. Ioannina)

High-Energy Physics & RIKEN Theory Seminar:
Relic Neutrinos in Cosmology-The prospects of detecting relic antineutrinos by capturing
them in nuclei

May 28

12

Martin Hentschinski (BNL)

RIKEN/BNL Lunch Time Talk

May 29

13

Takumi Doi (RNC) et al.

第 2 回 高エネルギーQCD・核子構造 勉強会
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1515

May 3014

Naoto Tanji (RIKEN/BNL)RIKEN/BNL Lunch Time Talk:
Real-time lattice simulations of fermion fields and Quark production in heavy-ion collisions

Jun. 5

15

Ron Longacre (BNL)

Nuclear Physics & RIKEN Theory Seminar:
Flow or Flux Tubes or both

Jun. 6- 541 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅹ. LIST OF SEMINARS

16

Masanori Hanada (YITP)

Nuclear Physics & RIKEN Theory Seminar:
Why does black hole describe deconfinement phase?

Jun. 13

17

Thomas Hambye(UCL, Brussel)

High-Energy Physics & RIKEN Theory Seminar:On the possibilities of probing a hidden sector dark matter particle

Jun. 18

18

Sean Bartz (U. Minnesota)

Nuclear Physics & RIKEN Theory Seminar:
A Dynamical Three-Field AdS/QCD Model

Jun. 23

19

Masakiyo Kitazawa (Osaka U.)

Nuclear Physics & RIKEN Theory SeminarJun. 30

20

Philipp Scior (TU Darmstadt)

RIKEN/BNL Lunch Time Talk:
Effective Theories with heavy quarks on the latticeJul. 321

Ahmed Ismail (ANL & UIC)

High-Energy Physics & RIKEN Theory Seminar:
When is a top quark a parton?

Jul. 922

Juchien Xu (Columbia U.)

Nuclear Physics & RIKEN Theory Seminar

Jul. 1123

Yuki Yokokura (Kyoto U.)

素核宇宙融合レクチャーシリーズ第 12 回: ブラックホールの蒸発と情報問題

Jul.
15-16

24

Al Mueller (Columbia U.)

Nuclear Physics & RIKEN Theory Seminar:
Fluctuations and geometric scaling in statistical and particle physics

Jul. 18

25

Tigran Kalaydzhyan(Stony Brook U.)

Nuclear Physics & RIKEN Theory Seminar:
Interaction of QCD strings and collective phenomena

Jul. 25

26

Masashi Hayakawa(Nagoya U.)

Nuclear Physics & RIKEN Theory Seminar:
Upgrade of QED contribution to lepton $g-2$

Aug. 1

27

Terukazu Ichihara (Kyoto U.)

RIKEN/BNL Lunch Time Talk:
QCD phase diagram with both fluctuation and finite coupling effects in the strong couplinglattice QCD

Aug. 728

Adrian Dumitru(Baruch College)

Nuclear Physics & RIKEN Theory Seminar

Aug. 829

Tom Blum(Univ of Connecticut)

High-Energy Physics & RIKEN Theory Seminar:
Nucleon Electric Dipole Moments

Aug. 830

Koichi Hattori (RIKEN/RBRC)

RIKEN/BNL Lunch Time Talk:
Photon propagations and charmonium spectroscopy in strong magnetic fields

Aug. 1431

Gabriel Denicol (McGill U.)

Nuclear Physics & RIKEN Theory Seminar

Aug. 15

32

Ralf Seidl, Yasuyuki Akiba(RNC) et al.

第 3 回 高エネルギーQCD・核子構造 勉強会
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1563

33

Shoichiro Tsutsui (Kyoto U.)

RIKEN/BNL Lunch Time Talk:
Parametric instabilities of color magnetic field

Aug. 28

34

Qun Wang

Nuclear Physics & RIKEN Theory Seminar

Aug. 29

35

Chris Korthals Altes(NIKHEF & Centre Physique
Theorique au CNRS)

RIKEN/BNL Lunch Time Talk:
What causes the instability of the Stefan-Boltzmann plasma?

Sep. 1136

Bjoern Schenke

Nuclear Physics & RIKEN Theory Seminar

Sep. 1237

Zhen Liu (U. Pittsburgh)

High-Energy Physics & RIKEN Theory Seminar:
Neutralino Dark Matter in the (N)MSSM: Direct/Indirect Detection and Collider Searches

Sep. 1738

Matthew Buckley(Rutgers, The State U. New
Jersey)High-Energy Physics & RIKEN Theory Seminar:
Searching for new scalars and dark matter at the LHC

Sep. 24- 542 -

Ⅹ. LIST OF SEMINARSRIKEN Accel. Prog. Rep. 48 (2015)39

Stefan Meinel(U. Arizona/RBRC)

RIKEN/BNL Lunch Time Talk:
Heavy baryons in lattice QCD

Oct. 240

Ayres Freitas (U. Pittsburgh)

High-Energy Physics & RIKEN Theory Seminar:
Opening the loops: The muon g-2 at the LHC

Oct. 841

Steffen Bass

RHIC & Users' Group Open Forum Meeting

Oct. 942

Isao Watanabe, Noraina
Adam, Siadah Sakinah, Edi
Suprayoga (RNC)

DFT 法によるミュオン位置計算セミナー

Oct. 16

43

Piotr Korcyl (Columbia U.)

RIKEN/BNL Lunch Time Talk:
A non-perturbative renormalization scheme in position space: A non-perturbative
renormalization scheme in position space

Oct. 16

44

Ho-Ung Yee(U. Illinois – Chicago)

Nuclear Physics & RIKEN Theory Seminar:
Aspects of Chiral Magnetic and Vortical Effects at Weak Coupling

Oct. 1745

Majed Jawad (RNC)

Advanced Meson Science Lab. seminar

Oct. 2346

David Mesterhazy(U. Illinois – Chicago)

Nuclear Physics & RIKEN Theory Seminar:
Dynamics of the chiral phase transition ‒ Universal fluctuations near criticality –Oct. 2447

Eugene Levin(Tel Aviv U. & UTFSM)

RIKEN/BNL Lunch Time Talk:
Large $b$ behaviour and CGC/saturation approach: the BFKL equation with massive gluon

Oct. 30

48

Yuji Hirono (Stony Brook U.)

Nuclear Physics & RIKEN Theory Seminar:
Charge-dependent correlations from event-by-event anomalous hydrodynamics

Oct. 3149

Itaru Nakagawa (RNC) et al.

第 4 回 高エネルギーQCD・核子構造 勉強会
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1653

Nov. 1

50

Simone Marzani (MIT)High-Energy Physics & RIKEN Theory Seminar:
The Higgs Cross Section from Analyticity

Nov. 551

Alfonso Sastre(Bergische U. Wuppertal)

Joint Riken Lunch/Nuclear Theory/RIKEN Seminar:
Some results on Lattice QCD at the physical point: SU(2) chiral perturbation theory and somewords about hadron vacuum polarization

Nov. 652

Yuta Kikuchi (Kyoto U.)

Nuclear Physics & RIKEN Theory Seminar:
Derivation of the Hydrodynamic Equation from the Quantum Transport Equation

Nov. 753

Zackaria Chacko (Maryland)

Joint HET/YITP/RIKEN Seminar:
Colorless Top Partners, a 125 GeV Higgs and the Limits on Naturalness

Nov. 1254

Kirill Boguslavski(U. Heidelberg)

RIKEN/BNL Lunch Time Talk

Nov. 1355

Ismail Zahed (Stony Brook U.)

Nuclear Physics & RIKEN Theory Seminar:
Holographic Strings in ep, pp and pA

Nov. 14

56

Kim Maltman (York U.)

High-Energy Physics & RIKEN Theory Seminar:
A Hybrid Strategy for the Lattice Evaluation of the LO HVP Contribution to the Muon
Anomalous Magnetic Moment

Nov. 19

57

Jacquelyn Noronha-Hostler(Columbia U.)

RIKEN/BNL Lunch Time Talk:
Bulk viscosity-driven suppression of shear viscosity effects on the flow harmonics at RHIC

Nov. 20

58

Anna Stasto (Penn State U.)

Nuclear Physics & RIKEN Theory Seminar:
Scattering amplitudes and recursion relations in light-front perturbation theory

Nov. 21

59

Nils Strodthoff (Heidelberg U.)

RIKEN/BNL Lunch Time Talk:
Exploring the phase structure and the dynamics of QCD

Dec. 460

Yachao Qian (Stonybrook U.)

Nuclear Physics & RIKEN Theory Seminar:
Spin Asymmetries and P-odd effects through QCD instantons

Dec. 5

61

Sanjay Reddy(U. Washington)

High-Energy Physics & RIKEN Theory Seminar:
The transport properties of cold dense matter

Dec. 10- 543 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅹ. LIST OF SEMINARS

62

Yuki Okura (BNL)

RIKEN/BNL Lunch Time Talk:
LSST sensor effect in constraining the cosmological parameterDec. 1163

Sean Fleming (U. Arizona)

Nuclear Physics & RIKEN Theory Seminar:
Forward scattering in SCET: Glauber exchange and the BFKL equation

Dec. 1264

Isao Watanabe, Noraina
Adam、Siadah Sakinah、Edi
Suprayoga、Sungwan Yoon

RIKEN Seminar:
USM-Sophia-Riken International Workshop on Frontiers of Muon Physics Program

Dec.
15-16

65

Toh Pek Lan(U. Sains Malaysia）

Indonesia/Malaysia Seminar:
Penyiasatan Teori Fungsi Ketumpatan untuk Struktur Elektronik dan Interaksi Hiperhalus
bagi Muonium dalam Terbitan Imidazole

Dec. 1766

Peter Lepage (Cornell)

High-Energy Physics & RIKEN Theory Seminar:
High-Precision QCD Parameters from Lattice QCD

Dec. 17

67

Satri Zulkarnaen Bisri (CEMS)

Indonesia/Malaysia Seminar:
Electronic Transport in Nanomaterials

Dec. 18

68

Hans-Peter Schadler (U. Graz)

RIKEN/BNL Lunch Time Talk:
Generalized quark number susceptibilities at finite chemical potential from fugacity
expansion on the latticeDec. 18

69

Toru Kojo(U. Illinois –Urbana-Champaign)

Nuclear Physics & RIKEN Theory Seminar:
Phenomenological QCD equation of state for massive neutron stars

Dec. 1970

Arun Madhav thalapilili(Rutgers)

High-Energy Physics & RIKEN Theory Seminar:
The Higgs as a Probe for New Physics : Higgs Portals, Soft Yukawas and Extended Gauge
Mediation

Jan. 771

Vladimir Skokov(Western Michigan U.)

Nuclear Physics & RIKEN Theory Seminar:
Anisotropy of the semi-classical gluon field of a large nucleus at high energy

Jan. 972

Yue Zhang (Caltech)

High-Energy Physics & RIKEN Theory Seminar:
Exploring Dark Matter and Baryon Asymmetry: Higgs is the Key

Jan. 14

73

Sayantan Sharma (BNL)

RIKEN/BNL Lunch Time Talk:
The origin of axial anomaly and the high temperature phase of QCD

Jan. 1574

Mauricio Martinez Guerrero(Ohio State U.)

Nuclear Physics & RIKEN Theory Seminar:
A new exact solution to the Boltzmann equation and its hydrodynamical limit

Jan. 1675

Julia Angel (Saitama U.)

Indonesia/Malaysia Seminar:
Crystal Growth and Magnetism of Layered Antiferromagnet Deuterated κ-(BEDT-TTF)2Cu[N(CN)2]Br

Jan. 2376

Wilke van der Schee (MIT)

Nuclear Physics & RIKEN Theory Seminar:
Strong coupling QGP thermalization with longitudinal dynamics

Jan. 23

77

Grigory Ovanesyan(U. Massachusetts Amherst)

Nuclear Physics & RIKEN Theory Seminar:
Regge behavior in effective field theory

Jan. 30

78

Antonin Portelli(U. Southampton)

High-Energy Physics & RIKEN Theory Seminar:
Ab initio calculation of the neutron-proton mass difference

Feb. 479

Vincenzo Cirigliano(Los Alamos)High-Energy Physics & RIKEN Theory Seminar:
Electric Dipole Moments, New Physics, and (lattice) QCD

Feb. 1180

Tigran Kalaydzhyan(Stony Brook U.)

Nuclear Physics & RIKEN Theory Seminar:
Gravity waves generated by sounds from cosmological phase transitions

Feb. 1381

Mariengela Lisanti (Princeton)

High-Energy Physics & RIKEN Theory Seminar:
The Search for Relic Neutrinos

Feb. 2582

Marlene Nahrgang

Theory and Modeling for the beam energy scan: From Exploration to Discovery

Feb.
26-27

83

Samuel MacDermott

High-Energy Physics & RIKEN Theory Seminar:
The Galactic Center Gamma-ray Excess: Have We Started to See Dark Matter?

Mar. 4- 544 -

Ⅹ. LIST OF SEMINARSRIKEN Accel. Prog. Rep. 48 (2015)84

Constantin Loizides

Collectivity in small colliding systems with high multiplicity

Mar. 4-6

85

Jorge Noronha (Sao Paulo U.)

Nuclear Physics & RIKEN Theory Seminar:
Hydrodynamic transport coefficients for the non-conformal quark-gluon plasma from
holography

Mar. 13

86

Luca Vecchi (U. Maryland)

HET/RIKEN Seminar:
Spontaneous CP violation and the strong CP problem

Mar. 1887

Antonio Ortiz Velasquez(National Autonomous U.
Mexico)Nuclear Physics & RIKEN Theory Seminar:
Flow like behavior in small systems -- Multi-parton interactions and color reconnection effects
at LHC energies

Mar. 2088

Can Kilic (U. Texas – Austin)

HET/RIKEN Seminar:
Flavored Dark Matter with Weak Scale Mediators

Mar. 25

RIBF Research Division1

Hermann Wollnik (Giessen)

A mass spectrometer for the ROSETTA space-mission to a comet
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1479

Apr. 92

Toshiro Shigaki (Papua New
Guinea National Agricultural
Research Inst.)

パプアニューギニアおよびソロモン諸島におけるサツマイモ並びにアイビカ（トロロアオイ）の遺伝資
源管理と品種改良

May 14

3

Hirofumi Noda (RNC)

High Energy Astrophysics Lab. Seminar:
X-ray studies of Central Engine in Active Galactic Nuclei
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1525

Jun. 5

4

Claudio Ricci (Kyoto U.)

High Energy Astrophysics Lab. Seminar: X-ray reflection features as a probe of the structureand evolution of circumnuclear material in Active Galactic Nuclei
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1554

Jul. 4

5

Takayuki Yuasa (RNC)

High Energy Astrophysics Lab. Seminar:
White dwarf mass estimation method based on X-ray spectral modeling
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1569

Jul. 17

6

Ken Takayama (KEK)

RIBF Accelerator Seminar:
Induction microtron and its application
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1580

Jul. 31

7

Renata S. Cumbee(U. Georgia)

Charge Exchange in the Cygnus Loop?
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1586

Aug. 88Hiroyoshi Sakurai &Tomohiro Uesaka (RNC)

Lectures for theory researchers:
Current status and future of RIBF experiments (I)
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1600

Aug. 18

9

Yoichi Nagashima(Copenhagen U.) &Hiroshi Ezawa (Gakushuin U.)

Bohr's 8mm film in 1937
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1643

Oct. 24

10

Yukari Matsuo (Hosei U.)

Nuclear Spectroscopy Laboratory Seminar:
超流動ヘリウム中原子の精密レーザー分光 -OROCHIhttp://indico2.riken.jp/indico/conferenceDisplay.py?confId=1657

Oct. 31

11

Tomoko Abe (RNC)

戦略的オミクス育種技術体系の構築

Nov. 21

12

Benoit Gall (Strasbourg U)

How did Earth generate and operate more than 15 Natural Nuclear Reactors?
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1695

Dec. 15

13

Chris Done (Durham U.)

High Energy Astrophysics Lab. Seminar:
The disc-spin-jet connection in stellar and supermassive black holes
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1766

Feb. 24

14

Yoshio Kobayashi(U. Electro-Communications)

Nuclear Spectroscopy Laboratory Seminar:
短寿命不安定核を用いたインビーム・メスバウアー分光法の物質科学への応用
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1797

Mar. 11

15

Shinsuke Fujioka (Osaka U.)

High Energy Astrophysics Laboratory Seminar:
Application of laser-generated strong magnetic field to plasma physics research
http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1796

Mar. 12

16

Hideki Ueno (RNC)

Lectures for theory researchers:
Current status and future of RIBF experiments (II)http://indico2.riken.jp/indico/conferenceDisplay.py?confId=1795

Mar. 20- 545 -

RIKEN Accel. Prog. Rep. 48 (2015)

Ⅹ. LIST OF SEMINARS

CNS
1Kathrin Wimmer(U. Tokyo/CNS)In-beam gamma-ray spectroscopy with GRETINA at the NSCL

Dec. 1

2

Javier Menendez(U. Tokyo)

From nuclear structure to neutrinos and dark matterDec.163

Tetsuya Sakurai (U. Tsukuba)

A Scalable Parallel Eigensolver for Large-scale Simulations on Petascale Computing
EnvironmentJan. 19

Two-neutron correlations in the ground and excited states of 6He

Sep. 18

Niigata Univ.
1

Yuma Kikuchi (RNC)

2

A. G. Magner
Semiclassical shell-structure moment of inertia within the phase-space approach(Institute for Nuclear Research,
Kyiv)
Yoshihumi Shimizu
角運動量射影法によるエキゾチックな変形・回転状態の研究(Kyushu U.)

3

4

Takayuki Yamaguchi(Saitama U.)

重イオンビーム荷電変化反応による不安定核の陽子分布半径- 546 -

Nov. 11

Nov. 27

Jan. 22

AUTHOR INDEXRIKEN Accel. Prog. Rep. 48 (2015)

AUTHOR INDEXAABDEL-JAWAD Majed
ABE Hiroshi
ABE Tomoko
ABE Yasushi
ABE Yugo
ACHOURI N.Lynda
ADACHI Shintaro
ADACHI Tadashi
ADAM Noraina
ADARE Andrew
ADIPERDANA Budi
AGRAWAL Bijay Kumar
AHMAD Siti Nur Afifi
AHN Deuk Soon
AIHARA Toshimitsu
AIKAWA Masayuki
AIKAWA Shu
AISO Hiroko
AKAISHI Yoshinori
AKASHIO Atsuko
AKIBA Yasuyuki
AKIMITSU Jun
AKIYOSHI Hideharu
ALAGU Manickavelu
ALHARBI Thamer
ANDREYEV Andrei
AOI Nori
AOKI Yasumichi
AONO Ryuji
APRILIA Annisa
ARAI Fumiya
ARIGA Hiroko
ARUMUGAM Paramasivan
ASAHI Koichiro
ASAI Masato
ASAKURA Kiyotaka
ASAMI Fumi
ASANO Hidemitsu
ASSIÉ Mariène
AUDIRAC Laurent
AUMANN Thomas
AUTHELET Gilles
AVIGO Riccardo
AYYAD Yassid

258, 273
313
301, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312,
313, 314, 315, 316
24, 76, 231, 232
154
42, 44, 45
257
257, 258
268, 269
112, 113, 114
269
90
268
6, 9, 11, 31, 32, 39, 54, 71, 72, 73, 74, 75, 235
326
6, 97, 98, 99
125323
140, 141, 142
238, 323
111, 112, 113, 114, 122, 245
265
168
314
35
47, 48, 49, 202
4, 33, 34, 36, 37, 38, 40, 61, 209, 210
144
292, 293272
22, 216, 226
275, 276
88
8, 64, 65
26, 70, 282, 283
275
179
111, 112, 113, 114, 245
7, 55
4
38, 39, 41, 42, 44, 45, 47, 48, 49, 202
5, 52
38, 39, 40, 41
204

B
BABA Hidetada
BABA Tatsuo
BAHTIAR Ayi
BAN Tomohiro
BANERJEE Kaushik
BANERJEE Sudhee
BAQIYA Malik A.
BARNEY JonBARTL Alfred
BATHE Stefan
BAUER Christopher
BAZIN Daniel
BEANE Silas
BEAUMEL Didier
BEDNARCZYK Piotr
BELLO GARROTE Frank L.
BENERJEE Sudhee Ranjan
BENNETT Douglas
BENTZ Wolfgang
BENZONI Giovanna
BERECZKY Réka Judit
BERG Georg
BERNER Christian
BEZBAKH Andrei A.
BHATTACHARYA Srijit
BLACK Kevin
BLANK Bertram
BLASI Nives
BLAZHEV Andrey
BÖHMER Michael
BOIANO Alfonso
BOIANO Ciro
BOISSINOT Simon

3, 4, 5, 6, 7, 21, 25, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39,
40, 41, 42, 44, 45, 47, 48, 49, 50, 51, 52, 54, 55, 59, 60,
62, 72, 202, 203, 204, 210, 215, 230, 246, 249
7, 55
272
314
77
38
257, 258
204, 206
143
112, 113, 114
40
21, 51, 203
128
7, 55, 56, 57, 62
4
31, 32, 33, 34
77
12
132
41
315, 316
59, 60, 235
69
62
77
175
29
41
29
47, 48, 49, 202
66
66
4

BORETZKY Konstanze
BOUTACHKOV Plamen
BOYLE Kieran
BRACCO Angela
BRAGA Davide
BRAMBILLA Sergio
BRAND Holger
BROWNE FrankBRUCE Alison
BRYSLAWSKYJ Jason
BRZYCHCZYK Janusz
BURROWS Ian

39, 4129
105
38, 39, 41247
41
26, 282
3, 5, 29, 31, 32, 33, 34, 35
35
111, 112, 113, 114
205
247

C
CAESAR Christoph
CALVET Denis
CAMERA Franco
CARROLL Robert
CAUSSIN SarahCELIKOVIC Igor
CERUTI Simone
CHAE Hyunwoo
CHAE Kyungyuk
CHAKRABARTY Dipak R
CHANG Emmanuel
CHANG Wen-Chen
CHAO Wen
CHATEAU Frederic
CHEBOTARYOV Sergey
CHEN Sidong
CHIBA Masaki
CHIGA Nobuyuki
CHIYONISHIO Iori
CHOI Seonho
CHU Minh Lee
CHUJO Tatsuya
CHUNG Le Xuan
CIEMALA Michal
CLOET Ian
COHEN Saul
COLE Ryan
COLEMAN-SMITH Patrick
CORSI Anna
CRESPI Fabio Celsio Luigi
CSATLÓS Margit
CURCEANU Catalina
CURRAN Mark38, 39, 52
5, 52
38, 39, 41
35
101, 10329
38, 41
62
35
90
128
244
21, 51, 54, 203, 211
562, 218, 224
38, 39, 41
97
50
281
62
244
120
5
4
132
128
175
247
4, 5, 52
41
54
12
167

D
DAIDO RieDANTSUKA Tomoyuki
DAS Sarah
DATAR Vivek M
DAUGAS Jean-Michel
DAVINSON Thomas
DE Aloklrurnar
DE FRANCE Gilles
DELAUNAY Franck
DELBART Alain
DEMICHI Kimihiko
DERYA Vera
DETMOLD William
DEY Balaram
DI NITTO Antonio
DIDIERJEAN Francois
DINH DANG Nguyen
DOBACZEWSKI Jacek
DOMBRADI Zsolt
DOORNENBAL Pieter
DORIESE William
DOZONO MasanoriDÜLLMANN Christoph E.

31, 32, 33, 34
328, 329, 331
167
90
31, 32247
77
2942, 44, 45
5, 52
209
38, 39128
77
26, 28231
32
77, 88, 90, 91
81
5, 35, 40, 54
1, 3, 4, 5, 6, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
40, 41, 42, 44, 45, 50
12
7, 21, 47, 48, 49, 51, 52, 54, 55, 56, 57, 58, 59, 60, 202,
203, 235
26, 282

E
EBARA Yuta
EBATA Shuichiro
EBERL Helmut
EDWARDS Ross
EGAMI Tsuyoshi
EICHLER Robert

8
97, 98, 99
143
167
64, 6526, 282

RIKEN Accel. Prog. Rep. 48 (2015)

ELEKES Zoltan
ENDRES Janis
ENOKIZONO Akitomo
ENOMOTO Masaya
ENOMOTO Shuichi
ENOTO Teruaki
EN'YO Hideto
ESTEE Justin
ESTRADE Alfredo
ETOH Daijiro
EVEN Julia
EYNARD Bertrand

40, 53, 61
39
23, 227, 228, 230
271
289, 290
17, 172, 175, 176, 177, 179, 180248
204, 20635, 247
235
26, 282
163

F
FAESTERMANN Thomas
FAN Fangli
FANG Yifan
FENG Jun
FLAVIGNY Freddy
FOMICHEV Andrey Sergeevich
FOWLER Joseph
FRANCHOO Serge
FUJII Toshihiko
FUJIKAWA Kazuo
FUJIMAKI Masaki
FUJIMURA Kenji
FUJINAWA Tadashi
FUJIOKA Hiroyuki
FUJITA Kunihiro
FUJITA Masaki
FUJITA Shin
FUJITA Tomomi
FUJIWARA Masashi
FUKAHORI Tokio
FUKASAKU Kazuaki
FUKUCHI Tomonori
FUKUDA Naoki
FUKUDA Shigekazu
FUKUDA Yoshiki
FUKUNAGA Taku
FUKUNISHI Nobuhisa
FUKUSHIMA Yomei
FUKUZAWA Seiji
FULOP Zsolt
FUNAKI Yasuro
FUNAYAMA Chikako
FURUKAWA Takeshi
FURUMOTO Takenori
FURUNO Tatsuya
FURUTACHI Naoya
FURUYA Yoshiyuki
FUWA Yasuhiro

29
26, 282
29, 31, 32, 33, 34
52
52
62
12
3, 5
7, 55, 56, 57
160, 161
19, 193, 194, 326, 327, 331
259
327, 331
235, 23658
257
323
8, 64, 65, 223, 251
263
6
317
289, 2906, 7, 9, 11, 21, 31, 32, 33, 34, 35, 39, 41, 42, 44, 45, 47,
48, 49, 50, 51, 54, 55, 56, 57, 58, 59, 60, 71, 72, 73, 74,
75, 202, 203, 208, 225, 235
317
279, 281, 285
56, 5719, 189, 190, 193, 194, 195, 235, 317, 326, 327, 331
115
19, 189, 327, 331
61
79
64, 658, 64, 65, 223, 251
459, 60
99
271
198

G
GALINDO-URIBARRI Alfredo
GAMBERG Leonard
GARD Johnathon
GARG Umesh
GEISSEL Hans
GENDREAU KeithGERNHÄUSER RomanGEY Guillaume
GHELLER Jean-Marc
GIACOPPO Franciesca
GIAZ Agnese
GIBELIN Julien
GILLIBERT Alain
GININA Elena
GIORDANO Francesca
GO Shintaro
GOEL Namita
GOLOVKOV Michail Sergeevich
GORSHKOV Vlarmir Alexandrovich
GORSKA Magdalena
GOTO Naoya
GOTO Shin-ichi
GOTO Takayuki
GOTO Yuji
GOTTARDO Andrea
GRAHN Tuomas
GRANT AlanGRAWE Hubert
GRIFFIN ChrisGROSSE-PERDEKAMP Matthias
GUNJI Taku
GUO Hanjie

56, 57138
12
39
11, 72, 208, 235
178
29, 47, 48, 49, 202
3, 28, 33, 34
5, 52
5
38, 39, 41
42, 44, 45, 50, 52
5, 52
143
108
7, 33, 34, 37, 55
29
62
62
29
279, 283, 284, 285, 292
279, 284, 285, 286, 288, 292
260, 263
103, 107, 123
5
247
247
1, 30
35, 247
108
117, 118, 119, 121
261, 262, 263, 266, 269, 274

AUTHOR INDEXGUSTAFSSON Fredrik

12

H
HABA Hiromitsu
HACHIYA Takashi
HADYNSKA-KLEK Katarzyna
HAETTNER Emma
HAGINO Koichi
HAKI Yosuke
HAMAGAKI Hideki
HAMAMOTO Ikuko
HAMANAKA Makoto
HAMMACHE Fariouz
HAN Seyoung
HANEDA Masatoshi
HARAKEH Muhsin N.
HARKNESS-BRENNAN Laura
HARTMANN Willi
HASAN BASERI Dang Fatihah
HASE Masashi
HASEBE Hiroo
HASEGAWA Hirokazu
HASEGAWA Kunihiko
HASEGAWA Shoichi
HASHIMOTO Koji
HASHIMOTO Tadashi
HASSANVAND Maryam
HATAKEYAMA Atsushi
HAYAKAWA Seiya
HAYANO Ryugo
HAYASAKA Miki
HAYASHI Kazunori
HAYASHI Shinichi
HAYASHI Tatuya
HAYASHI Yoriko
HAYATO Asami
HAYS-WEHLE James
HAZAMA Hitoshi
HEIL Michael
HENNING Walter
HIDAKA Keisho
HIDAKA Yoshimasa
HIGAMI Naota
HIGASHIKAWA Kei
HIGASHIYAMA Koji
HIGEMOTO Wataru
HIGURASHI Yoshihide
HILL Joanne
HILTON GeneHIRABAYASHI Kazuhiro
HIRAI Hajime
HIRANO Tomonari
HIRAO Chika
HIRAYAMA Yoshikazu
HIRENZAKI Satoru
HIROSE Kentaro
HIRUNUMA-HIGURASHI Rieko
HJORTH-JENSEN Morten
HONG Byungsik
HONG KHIEM Le
HONMA Michio
HORII Hiroshi
HORIOKA Kazuhiko
HORVAT Andrea
HOSHINO Tomoya
HOSOMI Kenji
HSIEH Chia-Yu
HUANG Minghui
HUYSE MarkHWANG Jongwon
HWANG Sanghoon

22, 26, 69, 70, 214, 279, 280, 281, 282, 283, 284, 285,
286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296,
297, 298, 299, 321
111, 112, 113, 114, 245
5235
82, 83
230
117, 118, 119, 121
86
19, 194, 327, 331
7, 55
101, 103
329, 330
39
247
26, 282268
264
190, 191, 326, 327, 331
209
52115, 205
130, 131, 147, 148, 149, 150, 151, 152
12, 124, 235
141, 142
8, 251
67
12, 235, 236
8, 64, 65, 223, 251
281
117
252
305, 311, 313
172, 175, 176, 177, 178, 179, 180
12328, 329, 330
39
47, 48, 49, 202
143
157
252
289, 290
92
275
20, 183, 184, 186, 326, 327, 331
175
12
252
328, 329, 330
307, 315, 316
64, 6566, 71, 233, 234
235
47, 48, 49, 202
323
89
54, 205
68
89
235
199
38
39
116
205
244
26, 281, 282, 292
233
42, 44, 45, 50, 62
56, 57, 205

I
ICHIHARA Takashi
ICHIKAWA Shinichi
ICHIKAWA Yuichi
ICHIKAWA Yukina
ICHIMURA Koichi
ICHIMURA Munetake
ICHINKHORLOO Dagvadorj
ICHINOSE Katsunori
IDEGUCHI Eiji
IEKI Kazuo
IGARASHI Kimie
IGARASHI Suguru

25, 248, 249
229
8, 61, 64, 65, 71, 255
76
270
58
99
311, 312, 313
2, 7, 31, 32, 33, 34, 35, 36, 40, 55, 59, 60
38, 39, 41, 212
323
265

AUTHOR INDEXIIDA Kei
IIMURA Hideki
IIZUKA Norihiro
IIZUKA Satomi
IKEDA Keiji
IKEDA Shunsuke
IKEDA Tokihiro
IKENO Natsumi
IKEZAWA EijiILIESCU Mihai
ILIEVA Stoyanka
IMAI Nobuaki
IMAI Nobuyuki
IMAI Shotaro
IMAMURA Kei
IMAMURA Takashi
IMAO Hiroshi
INABE Naohito
INAFUKU Kiyohiko
INAMI Takeo
ISAKSSON Elisabeth
ISHIBASHI Yoko
ISHIDA Katsuhiko
ISHIGAKI Tomoki
ISHII Kotaro
ISHIKAWA Kenichi
ISHIKAWA Shigeru
ISHIKAWA Tomomi
ISHIMOTO Shigeru
ISHIYAMA Hironobu
ISOBE Tadaaki
ISODA Kyosuke
ITAHASHI Kenta
ITO Masahiko
ITO Wataru
ITO Yuta
IWAKIRI Wataru
IWASA Naohito
IWASAKI Masahiko
IWASHITA Yoshihisa
IZUBUCHI Taku
IZUMI Masako

RIKEN Accel. Prog. Rep. 48 (2015)

80
225
15
323
310
198, 199
315, 316
235
188, 197, 322, 326, 327, 331
122938, 39, 66, 71, 72, 233, 234, 319
73
97, 98, 99
8, 64, 65, 223, 251
168
190, 191, 192, 193, 238, 326, 327, 331
7, 9, 11, 21, 31, 32, 33, 34, 35, 39, 42, 44, 45, 47, 48, 49,
51, 54, 55, 56, 57, 58, 59, 60, 71, 72, 73, 74, 75, 202, 203,
208, 225, 235
61
154, 155
167
8, 64, 65, 76, 255
125, 274, 275, 276, 319
31, 32
307, 308, 311
317
19, 187, 327, 331
144
1266, 233, 234
3, 4, 5, 6, 21, 29, 31, 32, 33, 34, 35, 40, 42, 44, 45, 50, 51,
52, 54, 62, 71, 72, 203, 204, 205, 206, 212
271
12, 124, 235, 236
7, 55
265
8, 22, 213, 216, 226
172, 173, 175, 176, 177, 178, 179, 180
11, 61, 66, 71, 72, 73
12, 124, 125, 235
198
144301, 302, 315

J
JACOBS WilliamJÄGER Egon
JAHODA Keith
JEONG Sun Chan
JHANG GenieJIA Hui Ming
JOHN Philipp
JUNG Hyo-Soon
JUNGCLAUS Andrea

108
26, 282
175
66, 71, 233, 234
21, 51, 54, 203, 204, 205, 206
66
3
3, 31, 32
1, 4, 28, 29, 30, 40

K
KAGEYAMA Tadashi
KAHL Daid
KAJI Daiya
KALANTARI Seyed Zafarollah
KALANTAR-NAYESTANAKI Nasser
KAMBARA Tadashi
KAMEDA Daisuke
KAMIGAITO Osamu
KANAOKA Hiroshi
KANASAKI Masato
KANAYA Jumpei
KANAYA Yoshihisa
KANAZAWA Koichi
KANDA Sohtaro
KANEKO Junichi
KANEKO Kenta
KANEKO Masaki
KANEKO Masanori
KANESUE Takeshi
KANEYA Yusuke
KANG Zhong-Bo
KANNO Daiki
KANNO Koki
KANNO Ryoji
KASAMATSU Yoshitaka
KASE Masayuki
KATAYAMA Ichiro
KATAYAMA Kazuya
KATO Minoru

185, 327, 331
66, 67, 68, 240
22, 26, 69, 70, 214, 215, 282, 29314239239, 240, 254, 321
7, 9, 21, 31, 32, 33, 34, 42, 44, 45, 47, 48, 49, 51, 55, 56,
57, 72, 74, 75, 202, 203, 235
185, 186, 188, 190, 191, 193, 326, 327, 331
35254
26, 28252
14, 137, 139
125, 278
220
179, 188, 326
54
21, 51, 203
196, 198
26, 282, 283
138
42, 44, 45
243
274
280, 287, 293
190, 191, 193, 197, 237, 322, 326, 327, 328, 331
22, 216, 225, 226
260
322

KATO ReizoKATŌ Kiyoshi
KATONO Kazuhiro
KAWABATA Takahiro
KAWAHARA Tomomi
KAWAKAMI Shunsuke
KAWAMURA Kenji
KAWAMURA Yoshiharu
KAWANO Shigeyuki
KAWASAKI Ikuto
KAWASE Shoichiro
KAWASHIMA Kenji
KAYA Kunimitsu
KAZAMA Yusuke
KELLY Christopher
KHANDAKER Mayeen Uddin
KHARZEEV Dmitri
KHUYAGBAATAR Jadambaa
KIDERA Masanori
KIEN Luu ManhKIKUNAGA Hidetoshi
KIM Chong
KIM Dahee
KIM Dogyun
KIM Eunhee
KIM Gi Dong
KIM Minjung
KIM Sunji
KIM Wooyoung
KIM Yong Kyun
KIM Yung Hee
KIM UYEN Nguyen
KIMURA Sota
KIMURA TaroKINDLER Birgit
KINO AikoKINOSHITA Shunichiro
KIPFSTUHL Sepp
KISAMORI Keiichi
KITAGUCHI Takao
KITAYAMA Yuta
KIYOKAWA Yu
KNYAZEV A. G.
KOBA Keisuke
KOBAYASHI Genki
KOBAYASHI Kazuma
KOBAYASHI Kiyoshi
KOBAYASHI Motoki
KOBAYASHI Nobuyuki
KOBAYASHI Noriaki
KOBAYASHI Riki
KOBAYASHI Tohru
KOBAYASHI Tomohiro
KOBAYASHI Toshio
KOBAYASHI Yoshio
KOBLESKY Theodore
KODAIRA Satoshi
KOGIMTZIS Moschos
KOGURE Sachiko
KOHAMA Akihisa
KOHMURA Takayoshi
KOIKE Shigetoshi
KOIKE Yoji
KOIKE Yuji
KOJIMA Shuichiro
KOJOUHAROV Ivan
KOMATSUBARA Tetsuro
KOMINE Taro
KOMIYAMA Misaki
KOMORI Yukiko
KOMOTO Shota
KONDEV Filip
KONDO Yosuke
KORKULU Zeren
KORSHENINNIKOV Alexei A.
KOSE Ryoji
KOTAKA Yasuteru
KOWALSKA Magdalena
KOYAMA Ryo
KOYAMA Shunpei
KOYAMA Takumi
KOYAMA Yoji
KRASZNAHORKAY Attila
KRATZ Jens V.
KRIER Jörg

255
97, 99270
7, 38, 50, 55, 59, 60
56, 57, 219, 224
6, 52
167
154
309
259, 264, 265, 266
7, 21, 51, 54, 55, 56, 57, 58, 59, 60, 203, 235
265
310
304, 307, 308, 309, 310, 314
145
295
147
26, 282
20, 327, 331273
281, 286, 287, 288, 293, 297
103
52
71
62, 71
29
102, 10342, 44, 45, 62
56, 57, 218, 224
29, 3262, 66, 233, 234
68
66, 72, 73, 233, 234
16, 163, 164, 165
26, 282287
149, 150, 152
167
7, 21, 51, 54, 55, 56, 57, 58, 59, 60, 203, 235
172, 175, 176, 177, 179, 180
279, 281, 285
52, 58, 59, 60, 217, 235
62
169
274
33, 34, 58, 59, 60
19, 185, 197, 327, 331
7, 21, 33, 34, 51, 52, 54, 55, 56, 57, 58, 59, 60, 203, 220
21, 36, 38, 39, 41, 42, 44, 45, 47, 48, 49, 50, 51, 52, 54,
202, 203108
269
8, 223, 251
315, 316
21, 42, 44, 45, 47, 48, 49, 50, 51, 52, 54, 202, 203291112, 113, 114254
247
311, 313
80
179
252
257, 258
14, 137
64, 653, 29, 35
31, 32, 33, 34
64, 6519, 193, 194, 195, 326, 327, 331
69, 70, 279, 280, 281, 283, 284, 285, 287, 288, 293, 296,
297
289
35
7, 8, 21, 36, 38, 39, 41, 42, 44, 45, 47, 48, 49, 50, 51, 52,
54, 55, 202, 203, 207
5, 35, 52, 54
62
310
19, 185, 327, 331
29
19, 191, 192, 327, 331
5, 6, 21, 38, 39, 41, 46, 51, 52, 54, 203, 210
279, 285, 292
154, 155
21, 51, 54, 203
26, 282
26, 282

RIKEN Accel. Prog. Rep. 48 (2015)

KRÜCKEN Reiner
KRÜGER Kirstin
KRUPKO Sergey Anatolievich
KUBO Toshiyuki
KUBOKI Hironori
KUBONO Shigeru
KUBOTA Masahiro
KUBOTA Masato
KUBOTA Megu
KUBOTA Yuki
KUDO Hisaaki
KUDOU Yuki
KUDRYAVTSEV Yuri
KUMAGAI Keiko
KURATA-NISHIMURA Mizuki
KURITA Kazuyoshi
KUROE Haruhiko
KUROKAWA Meiko
KUROSAWA Maki
KURZ Nikolaus
KUSAKA Kensuke
KUSUMOTO Tamon
KUTI Istvan
KUWABARA Keisuke
KUZMIN Evgeny A.
KWON Young Kwan

29
167
62
7, 9, 11, 21, 31, 32, 33, 34, 35, 39, 41, 42, 44, 45, 47, 48,
49, 51, 54, 55, 56, 57, 58, 59, 60, 71, 72, 73, 74, 75, 201,
202, 203, 208, 220, 225, 235, 330
190, 191, 326, 327, 331
3, 6, 35, 62, 66, 68
329, 330
253
172, 175, 176, 177, 178, 180
5, 7, 21, 47, 48, 49, 51, 52, 54, 55, 56, 57, 58, 59, 60, 202,
203, 246
279, 284, 285, 286, 288, 292, 293, 294
26, 282, 287
233
19, 189, 194, 327, 331
7, 8, 21, 38, 39, 41, 50, 51, 54, 55, 62, 203, 204, 205, 206,
212
23, 61, 227, 228, 229, 230
264
53, 61, 62, 210
111, 112, 113, 114, 245
3, 26, 29, 35, 282
9, 11, 50, 56, 57, 71, 72, 73, 74, 75, 197, 201, 225, 235,
330
254
33, 34, 35
1262
31, 32L
LA COMMARA Marco
LALKOVSKI Stefan
LANE Gregory
LANG Ralf
LAPOUX Valérie
LASKO Pawel
LAYMAN Lawrence
LAZARUS Ian
LEBLOND Sylvain
LEE Cheongsoo
LEE Chun Sik
LEE Eunji
LEE Jenny
LEE Jung Woo
LEE Pilsoo
LEHNER Christoph
LEITGAB Martin
LENTZ Michael
LEONI Silvia
LETTMANN MarkLETTS Simon
LEWITOWICZ Marek
LI Hairong
LI Kouang
LI Zhihuan
LIANG Haozhao
LIAO Jinfeng
LIN Cheng Jian
LIN Huey-Wen
LIN Shu
LIU Hongliang
LIU Hongna
LIU Jiajian
LIU Zhengyu
LOMMEL Bettina
LORUSSO Giuseppe
LOTAY Gavin
LOUCHART Corinne
LOZEVA Radomira
LUBOS Daniel
LUKASIK Jerzy
LUO Yongkang
LYNCH William G.

66
35
35
47, 48, 49, 202
4, 5, 52
205
167
247
42, 44, 45, 50
7, 21, 51, 54, 55, 56, 57, 58, 59, 60, 203, 217
31, 3235
4, 5, 36, 37, 40, 42, 44, 45, 50
21, 51, 203
31, 32, 35
144
108
111
41
5
247
29
108
36
3, 29, 33, 34
94
127
66
128
146
2
40, 5035
247
26, 282
1, 3, 6, 28, 29, 30, 31, 32, 33, 34, 35, 62, 72, 212, 247
35
5
5, 31, 32
29, 62205
261
204, 205, 206

M
MA YueMACHIDA TomohiroMÄCKEL Volkhard
MAEDA Shuji
MAEDA Yukie
MAEYAMA Takuya
MAIE Takeshi
MAIER Ludwig
MAJEROTTO Walter
MAKABE Akiko

12, 124, 125
61
315
140
6, 7, 52, 55, 56, 57
317
19, 197, 326, 327, 331
48, 202
143
169

AUTHOR INDEXMAKINAGA Ayano
MAKISHIMA Kazuo
MANEA ChristianMÅNSSON Martin
MARLOWE Hannah
MARQUÉS Miguel F.
MARTEL Ismael
MARTON Johann
MARUYAMA Manami
MASELLI Olivia
MASUOKA Shoichiro
MATEA Iolanda
MATSUBA Hiroshi
MATSUBARA Hiroaki
MATSUDA Yasuyuki
MATSUDA Yohei
MATSUI Kazuki
MATSUI Keishi
MATSUKAWA Kenya
MATSUMOTO Miku
MATSUMURA Masahiro
MATSUO Saki
MATSUO Yukari
MATSUOKA Masaru
MATSUSHITA Masafumi
MATSUYANAGI Kenichi
MATSUZAKI Teiichiro
MATSUZAWA Hideyuki
MAY Morgan
MAZUMDAR Anupam
MAZZOCCO Marco
MCCONNELL Joseph
MCGLINCHEY Darren
MCINTOSH Alan
MEIER Ludwig
MENG Jie
MENGONI Daniele
METZ Andreas
MICHIMASA Shin'ichiro
MIDORIKAWA Katsumi
MIHARA Tatehiro
MIKAMI Akihiko
MIKI Kenjiro
MILJKO Bobrek
MILLION Bénédicte
MILMAN Evgeniy
MINAKATA Ryogo
MINEZAKI Takeo
MISHIMA Go
MITRA Arunodoy
MITSUGASHIRA Toshiaki
MITSUKAI Akina
MITSUOKA Shin-ichi
MITSUYA Yosuke
MIURA Hiroshi
MIYA Hiroyuki
MIYACHI Yoshiyuki
MIYASAKA ShouMIYASHITA Sunao
MIYATA Noboru
MIYATAKE Hiroari
MIYAZAKI Takuya
MIZUKAMI Atsushi
MIZUNO Nobuyuki
MIZUNO Sanshiro
MIZUSAKI Takahiro
MOHAMED IBRAHIM Mohamed Ismail
MOHD TAJUDIN Saidah Sakinah
MOMIYAMA Satoru
MONDAL Debasish
MONNAI Akihiko
MOON Chang Bum
MOON Taebong
MORALES Anna Isabel
MORFOUACE Pierre
MORI Yutaka
MORIMOTO Kouji
MORIMOTO Shota
MORIOKA Asami
MORISHITA Toshikazu
MORITA Kosuke
MORITA Ryouhei
MORIYA Yosuke
MORRISSEY DavidMOSCHNER Kevin
MOTIZUKI Yuko

6, 99
17
66
274
175
42, 44, 45, 52
39
12
168
167
38
3
252
7, 55, 56, 57
125
21, 47, 48, 49, 50, 51, 54, 202, 203, 211
263
3, 4, 5, 37, 247
254
64, 65266, 269
23, 227, 228, 230
8, 223, 251
184, 5, 33, 34, 36, 37, 38, 39, 40, 41, 50, 58, 59, 60, 209,
210, 220, 235
85
125
212
174
158
66
167
112, 113, 114
206
47, 4994
3
14, 137, 138, 139
7, 21, 33, 34, 36, 37, 38, 51, 54, 55, 56, 57, 58, 59, 60, 61,
203, 220, 235
125
18329, 330
7, 55
111
38, 39, 41
21, 51, 54, 62, 203, 218, 224
42, 44, 45, 50
170
235
90
287
279, 283, 285
47, 48, 49, 202
8, 251
24, 231, 328, 329, 330
7, 55, 56, 57, 58, 59, 60, 220, 235
123
123
26, 282253
66, 71, 72, 73, 233, 234
5, 52, 62, 63
59, 60304
109
89268, 269
268, 269
5, 6, 40, 210
77134, 135, 136
31, 32, 33, 34, 35
103, 111, 112, 113, 114, 245
413
254
22, 26, 69, 70, 214, 215, 255, 282, 293
31, 32290
305
26, 69, 70, 214, 215, 282, 293
311, 312, 313
23, 227, 228, 230
1129167, 168, 169

AUTHOR INDEXMOTOBAYASHI Tohru
MOTOMURA Shinji
MOTOYAMA Hideaki
MOTOYAMA Risa
MÜCHER Dennis
MUELLER Berndt
MUKAI Hiroki
MUKAI MomoMUKHOPADHYAY Supriya
MUNEKANE Masayuki
MURAI Daichi
MURAI Koji
MURAKAMI Hiroyuki
MURAKAMI Kento
MURAKAMI Masashi
MURAKAMI Tetsuya
MURATA Jiro
MURATA Keiju
MURATA Masaki
MUTO Kotomi

RIKEN Accel. Prog. Rep. 48 (2015)

4, 5, 21, 36, 37, 38, 39, 40, 41, 42, 44, 45, 47, 48, 49, 50,
51, 52, 53, 54, 61, 62, 202, 203, 209
289
167, 169
279, 285
21, 47, 48, 49, 51, 202, 203
134323
66, 71, 72, 73, 233, 234
77
289
9, 11, 31, 32, 42, 44, 45, 71, 72, 73, 74, 75, 235
304
209, 220281
26, 69, 70, 279, 280, 281, 282, 283, 284, 285, 286, 288,
292, 293, 294, 296, 297
21, 38, 42, 44, 45, 50, 51, 54, 103, 203, 204, 205, 206
103
149, 150, 152
16
42, 44, 45, 50

N
NACHER KikeNÁCHER EnriQue
NAGAE Daisuke
NAGAHIRO Hideko
NAGAI Junichi
NAGAI Kei
NAGAKURA Hiroyasu
NAGAME Yuichiro
NAGAMINE Kanetada
NAGAOKA Tetsuya
NAGASE Makoto
NAGASHIMA Toru
NAGATOMO Takashi
NAGAYOSHI Sanetaka
NAIMI Sarah
NAKABAYASHI Takumi
NAKAGAWA Itaru
NAKAGAWA Takahide
NAKAGOMI Hiroshi
NAKAGUCHI Yuki
NAKAHIRA Satoshi
NAKAI Wataru
NAKAI Yoichi
NAKAMURA Kouhei
NAKAMURA Masato
NAKAMURA Takashi
NAKAMURA Takeshi
NAKANO Kenichi
NAKANO Takehito
NAKAO Taro
NAKASHIMA Tomohiro
NAKATSUKA Noritsugu
NAKATSUKASA Takashi
NAKAYAMA Yu
NAM Tran
NAPOLI Daniel
NAQVI Farheen
NARA Shunpei
NARIKIYO Yoshihiro
NASUDA Shuhei
NAVIN Alahari
NEGORO Hitoshi
NEIL Ethan
NGOC DUY Nguyen
NIIKURA Megumi
NIIYAMA Masayuki
NIKOLSKII Evgenii Yu.
NINOMIYA Yu
NISHI Seijiro
NISHI Takahiro
NISHIBATA Hiroki
NISHIDA Kazuki
NISHIDA Minoru
NISHIMURA Daiki
NISHIMURA Makoto
NISHIMURA Shunji
NISHINAKA Ichiro
NISHIO Katsuhisa
NISHIO Yasutaka
NISHIOKA Takashi
NISHIURA Aiko

40
30
24, 76
235306
123
59, 6026, 282, 283
275, 276
279, 285
326, 327, 331
103, 115
185, 186, 326, 327, 331
306
54, 232
61
101, 103, 115
20, 183, 184, 185, 326, 327, 331
110, 111, 112, 113, 114, 245
153
18
241
168, 169
280
237, 327, 328, 331
11, 21, 38, 39, 41, 42, 44, 45, 47, 48, 49, 50, 51, 52, 54,
61, 202, 203, 207
19, 187, 194, 327, 331
123273
66, 67, 240
42, 44, 45
21, 38, 39, 41, 42, 44, 45, 47, 48, 49, 50, 51, 52, 54, 202,
203, 204, 211
81
155
244
3
3
123
69
304
42, 44, 45, 50
18
156
68
3, 5, 6, 31, 32, 40, 54, 62, 63, 210, 235
244
62
132
42, 44, 45
7, 55, 235, 236
3, 31, 32, 33, 34
172, 175, 176, 177, 178, 180
19, 187, 327, 331
4, 37, 59, 60
19, 185, 327, 331
1, 2, 3, 5, 8, 28, 29, 30, 31, 32, 33, 34, 35, 39, 40, 41, 47,
48, 49, 202, 212, 247
47, 48, 49, 202
47, 48, 49, 70, 202, 293
52
266, 269
304

NISHIZUKA Ippei
NITA Cristina
NITSCHE Heino
NIWA Sayaka
NODA Hirofumi
NOGUCHI Masato
NOJI Shumpei
NORO Tetsuo
NOTANI Masahiro
NOUICER Rachid
NOUMI Toshifumi
NOZAKI Hiroshi
NOZUE Yasuo
NUGROHO Agung29, 31, 32, 33, 34, 35
35
26, 282314
12, 170, 172, 181
330
756, 57
61
111, 112, 113, 114
15, 157, 158, 159
274
273
267

O
OBERTELLI Alexandre
ODA Keiji
ODAHARA Atsuko
ODASIHMA Hitoshi
ODSUREN Myagmarjav
OGAWA Akio
OGAWA Noriaki
OGIWARA Kiyoshi
OGLOBLIN Alexei A.
OGOSHI Shun
OH Choo HiapOHBU Sumie
OHKI Tomonori
OHKURA Ayaka
OHNISHI Hiroaki
OHNISHI Jun-ichi
OHNISHI Tetsuya
OHSHIMA Masaya
OHSHIRO Yukimitsu
OHTA Shigemi
OHTAKE Masao
OHTANI Bunsho
OHTOMO Yuichi
OHTSUKI Tsutomu
OIKAWA Hiroyuki
OISHI Yu
OKA Takashi
OKADA Shinji
OKAMOTO Sachiko
OKAMURA Masahiro
OKAYASU Tomomi
OKUBO Masashi
OKUDA Toshiro
OKUNO Hiroki
OKURA Yuki
OLIVIER LouisO'NEIL GalenONG Hooi Jin
ONISHI Takeo
OOE Kazuhiro
OOSAWA Akira
ORGINOS Kostas
ORLANDI Riccardo
ORR Nigel
OTA Shinsuke
OTA Shuhei
OTSU Hideaki
OTSUKA Takaharu
OTUKA Naohiko
OUTA Haruhiko
OYAIZU Michihiro
OYAMADA Kazuyuki
OYAMATSU Kazuhiro
OZAKI Tomoyuki
OZAWA Akira
OZEKI Kazutaka

4, 5, 40, 52, 56, 57
254
3, 31, 32, 33, 34, 35
251
99
108
15, 130, 153
252
6242, 44, 45, 50
160, 161
307, 308
188, 326
52, 54, 58
124, 244
50, 183, 327, 331
23, 25, 38, 227, 229
197, 328, 329, 330
185, 327, 331
129
9, 11, 71, 72, 73, 74, 75, 197, 201, 330
275
64, 65, 255
287
59, 60125148, 149, 150, 151, 152
12, 124, 125
169
196, 198, 199
323
291
310
187, 190, 191, 237, 326, 327, 328, 329, 331
174
5
1238, 61, 62
61
26, 279, 282, 283, 284, 285, 286, 288, 292
263
128
47, 48, 49, 202
42, 44, 45, 52
4, 5, 7, 21, 25, 38, 39, 51, 52, 54, 55, 56, 57, 58, 59, 60,
203, 217, 235
309
5, 6, 11, 21, 38, 39, 40, 41, 42, 44, 45, 46, 47, 48, 49, 50,
51, 52, 53, 54, 61, 62, 63, 71, 72, 202, 203, 246
36, 89, 96
97, 9912, 124
233, 234
188, 326
80
38, 39, 41, 52, 207
24, 76, 232, 234
20, 183, 184, 186, 326, 327, 331

P
PADILLA-RODAL Elizabeth
PAGE Robert
PAL Surajit
PALSTRA Thomas
PANCAKE Charles
PANDIT Deepak
PANIN Valerii
PANT Amba D.
PAPKA PaulPARASCANDOLO Concetta
PARK Jason
PARK Sanghwa

56, 57247
77
267
111, 245
77
21, 47, 48, 49, 51, 52, 53, 54, 202, 203
275, 276
62
66
29
103

RIKEN Accel. Prog. Rep. 48 (2015)

PARRENO Assumpta
PASCHALIS Stefanos
PASTERIS Daniel
PATEL Zena
PAWLOWSKI Piotr
PELLEGRI LunaPERON Cedric
PERREVOORT Ann-Kathrin
PETRI Marina
PEYAUD Alan
PIERROUTSAKOU Dimitra
PISARSKI Robert
PITONYAK Daniel
PLATT Francis
PLAZAS Andres A
PODOLYAK Zsolt
POLLACCO Emmanuel
POLYAKOV Alexey
POWELL William
PRATT Francis L.
PROKUDIN Alexei
PRYDDERCH Micheal
PUCKNELL Victor

128
52
167
2, 5, 29, 31, 32, 33, 34, 35
205
41
5
62
39
5
66
146
14, 137, 138, 139
275
174
2, 35
4, 5, 52267
21, 51, 62, 203, 204, 206
273, 276
138
247
247

Q
QIN ZhiQUANG HUNG Nguyen

26, 282
77, 90R
RAJABALI Mustafa Moiz
29
RASCO Charlie
53
REGAN Patrick
2, 35
REICHERT Sebastian21, 47, 48, 49, 51, 52, 54, 202, 203
REIFARTH Rene
39
REINTSEMA Carl
12
REPONEN Mikael
22, 216, 225, 226
RHINE KUMAR Arayakkandi Keechipprath 88
RICE Simon29, 31, 32, 33, 34
RINN Thimothy
112, 113, 114
RINTA-ANTILA Sami
247
RISDIANA
272
ROBERTS Oliver35, 247ROSSI Dominic
39
ROUSSÉ Jean-Yves5, 52
ROWAN Zack
112, 113, 114
ROZLAN Ainul Fauzeeha
268
S
SAASTAMOINEN Antti
SAFRIANI Lusi
SAGAWA Hiroyuki
SAHIN Eda
SAITO Atsumi
SAITO Norihito
SAITO Wataru
SAKAGUCHI Harutaka
SAKAGUCHI Satoshi
SAKAGUCHI Yuji
SAKAI Hideyuki
SAKAI Yasuhiro
SAKAKURA Yoshio
SAKAMOTO Hisao
SAKAMOTO Naruhiko
SAKAMOTO Yu
SAKO Hiroyuki
SAKO Masami
SAKUMA Fuminori
SAKURAI HiroyoshiSÁNCHEZ-BENÍTEZ Angel Miguel
SANTAMARIA Clémentine
SARSEMBAYEVA Aiganym
SASAMOTO Yoshiko
SASANO Makoto
SASANO Masaki
SATO Daisuke
SATO Hiromi
SATO Koichi
SATO Masaharu
SATO Susumu
SATO Tetsuya K.
SATO Tomoya
SATO Yuki
SATOU Yoshiteru
SATULA Wojciech
SAVAGE Martin

53
272
58, 82, 83, 86
3, 5, 33, 34
38, 39, 41, 52
125
103, 115
211
7, 21, 47, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 62, 202,
203, 218, 219, 224
66, 67
7, 21, 51, 54, 55, 56, 57, 58, 59, 60, 203, 319, 320
316
310
323
188, 193, 235, 326, 327, 331
64, 65245
21, 47, 48, 49, 51, 52, 54, 73, 202, 203
124
1, 2, 3, 4, 5, 6, 28, 29, 30, 31, 32, 35, 36, 37, 38, 39, 40,
41, 50, 54, 61, 62
66
4, 5, 40, 52
97, 997
175, 7, 21, 47, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 202, 203
279, 283, 285, 286, 292
7, 9, 11, 21, 42, 44, 45, 47, 48, 49, 50, 51, 52, 54, 55, 71,
72, 73, 74, 75, 201, 202, 203, 220
81
12, 124, 125245
26, 282, 283
64, 659, 11, 72, 73, 74, 75, 220
42, 44, 45, 50, 54, 62
81
128

AUTHOR INDEXSAVRAN Deniz
SAWADA Shin'ya
SAWAHATA KazukiSCHÄDEL Matthias
SCHAFFNER Henning
SCHEIT HeikoSCHINDLER Fabia
SCHLEGEL Marc
SCHMIDT Dan
SCHNELL Gunar
SCHROCK Philipp
SCHULTZ Jerome
SCHURY PeterSEDDON DavidSEIDL Ralf
SEKIGUCHI Kimiko
SEKIGUCHI Yuko
SEKINE Tomoyuki
SEMMLER Diego
SERA Masafumi
SEVERI Mirko
SHAND Callum
SHANE Rebecca
SHERRILL Brad
SHI Hexi
SHIBA Hideyuki
SHIBATA Junsho
SHIBATA Seiichi
SHIBATA Toshi-Aki
SHIGA Yoshiaki
SHIGAKI Kenta
SHIGEKAWA Yudai
SHIKATA Mizuki
SHIMAOKA Takehiro
SHIMIZU Noritaka
SHIMIZU Yohei
SHIMODA Tadashi
SHIMOMURA Koichiro
SHIMOURA Susumu
SHINDO Yusuke
SHINOHARA Atsushi
SHINOHARA Mayuko
SHINOZUKA Tsutomu
SHIOHARA Naoya
SHIRAI Hazuki
SHIRAKAWA Yuki
SHIRAKI Hidekazu
SHIRAKI Ichiro
SHITADE Atsuo
SHIU Gary
SIDORCHUK Sergey Ivanovich
SIEJA Kamila
SIGL Michael
SIGNORINI Cosimo
SIMON HaikSIMPSON Gary
SIMPSON John
SINCLAIR LauraSKOKOV Vladimir
SLEPNEV Roman Stanislavovich
SÖDERSTRÖM Pär-Anders
SOHLER DoraSONI Amarjit
SONODA Akihiko
SONODA Tetsu
SOSIN Zbigniew
STANKUS PaulSTEFAN Gheorghe
STEIGER Konrad
STEINEGGER Patrick
STEINER Jutta
STEPANYAN Samvel
STEPPENBECK DavidSTOLZ Andreas
STRACHAN JonSTRANO Emanuele
STUHL LászlóSUDA Kenji
SUDA Toshimi
SUGAWARA-TANABE Kazuko
SUGIMURA Hitoshi
SUGIYAMA Jun
SULAIMAN Shukri
SUMIKAMA Toshiyuki
SUMITA Takayuki
SUPRAYOGA Edi

39
123
76
26, 282, 283
3, 29, 35
36, 38, 39, 41
38, 39139
1210838, 39, 41276
22, 213, 216, 226
247
103, 104, 108
50, 235119264
39266, 269
167
5, 35
206
11
12
328, 329, 330
19, 197, 327, 331
298, 299, 321
123
4, 5, 6, 37, 38, 39, 40, 41, 62, 210
13280
21, 38, 39, 41, 51, 52, 54, 203, 207
220
89, 967, 9, 11, 21, 39, 42, 44, 45, 47, 48, 49, 50, 51, 52, 54, 55,
71, 72, 73, 74, 75, 202, 203
8, 31, 32
275, 276
7, 21, 25, 38, 51, 54, 55, 56, 57, 58, 59, 60, 203, 220
52, 54, 58
280, 287, 293
61
8
287
8
307, 308, 312
197, 328, 329, 330
276
165
157
62
28
167
66
39
1, 2, 28, 30, 33, 34
247
29, 31, 32, 33, 34
146
62
1, 2, 3, 5, 6, 28, 29, 30, 31, 32, 33, 34, 35, 37, 40, 62, 72
3, 4
144
148, 151
8, 22, 71, 216, 225, 226, 233
205
111
3, 5
29
282
26, 282
56, 574, 5, 36, 37, 38, 39, 40, 41
7, 55, 59, 60
247
66
21, 47, 48, 49, 51, 52, 54, 58, 202, 203
188, 193, 326, 327, 331
23, 227, 228, 230
93, 95205
274
268, 269
1, 3, 5, 21, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40,
41, 47, 48, 49, 50, 51, 52, 61, 202, 203
26, 111, 112, 113, 114, 245, 282
267, 268, 269

AUTHOR INDEXSUWAT Tangwancharoen
SUZAKI Fumi
SUZUKI Daisuke
SUZUKI Hiroshi
SUZUKI Ken
SUZUKI Kensuke M.
SUZUKI Mariko
SUZUKI NorioSUZUKI Ryuji
SUZUKI Takahiro
SUZUKI Takao
SUZUKI Takatoshi
SUZUKI Takeshi
SWETZ Daniel
SYMOCHKO Dmytro
SYNDIKUS Ina

RIKEN Accel. Prog. Rep. 48 (2015)

21, 51, 203
24, 232
3, 5
6, 7, 9, 11, 21, 31, 32, 33, 34, 35, 39, 42, 44, 45, 47, 48,
49, 51, 54, 55, 56, 57, 58, 59, 60, 71, 72, 73, 74, 75, 202,
203, 208, 225, 235
12, 235
257, 258
155
330
323
8, 64, 65, 255
260, 263
12
215, 23212
39
38, 39T
TABATA Hiromi
TABATA Munemi
TADA Tsukasa
TADOKORO Makoto
TAKAHASHI Kazuya
TAKAHASHI Kento
TAKAHASHI Naruto
TAKAHASHI Nobuaki
TAKAKI Motonobu
TAKAMATSU Takahide
TAKAMINE Aiko
TAKAMIYA Koichi
TAKEBAYASHI Akiko
TAKECHI Maya
TAKEDA Hiroki
TAKEDA Hiroyuki
TAKEDA Masayasu
TAKEICHI Hiroshige
TAKEKOSHI Mamoru
TAKESHITA Takeshi
TAKETANI Atsushi
TAKEUCHI Satoshi
TAKEUCHI Yoko
TAKEYAMA Mirei
TAKO Tadashi
TAMAE Tadaaki
TAMAGAWA Toru
TAMII Atsushi
TAMURA Masashi
TANABE Kosai
TANAKA Akira
TANAKA Hidekazu
TANAKA Junki
TANAKA Kanenobu
TANAKA Kazuo
TANAKA Kengo
TANAKA Mana
TANAKA Ryuki
TANAKA Taiki
TANAKA Yoshiki
TANG Leung
TANG Tsz Leung
TANGWANCHAROEN Suwat
TANIBE Kenji
TANIDA Hiroshi
TANIDA Kiyoshi
TANIGUCHI Takumi
TANIUCHI Ryo
TANOKASHIRA Yuki
TAPROGGE JanTARASOV Oleg
TATEISHI Kenichiro
TATSUNO Hideyuki
TERANISHI Takashi
TERASAKI Kohei
TERASHIMA Satoru
TERUYA Eri
THOMAS Stephen
TIBURZI BrianTIMÁR János
TOBA Ryota
TOGANO Yasuhiro
TOGASAKI Mamoru
TOGASHI Tomoaki

58
52, 54162
271
169, 298, 299, 321
42, 44, 45287
240
7, 21, 51, 54, 55, 56, 57, 58, 59, 60, 203, 217, 220, 235
223
64, 65, 125
287
252
36
265
6, 7, 9, 11, 21, 31, 32, 33, 34, 35, 38, 39, 42, 44, 45, 47,
48, 49, 51, 54, 55, 56, 57, 58, 59, 60, 71, 72, 73, 74, 75,
202, 203, 208, 225, 235
253
240, 321
323
309
111, 112, 113, 114, 245
4, 5, 6, 7, 25, 36, 37, 38, 39, 40, 41, 42, 44, 45, 50, 55, 59,
60, 61, 62, 209, 210
172, 175, 176, 177, 178, 179, 180
26, 69, 70, 214, 215, 282, 293
21, 51, 203
23, 227, 228, 230
17, 18, 172, 174, 175, 176, 177, 178, 179, 180, 181
7, 38, 55
188, 326
93, 95288
260, 263
211
61, 238, 323
125, 277
26, 69, 70, 214, 215, 282
33, 3442, 44, 45
69, 70, 293
235, 236
7
56, 57, 219
204, 205, 206
273
266, 269103
281
3, 4, 5, 6, 37, 38, 39, 40, 41, 210
306
1, 3, 28, 30, 33, 34, 40
11, 72
218, 219, 221, 222, 224
12
66
121
35
92
247
128
54
23, 227
21, 36, 38, 39, 41, 42, 44, 45, 47, 48, 49, 50, 51, 52, 54,
61, 202, 203, 207, 209, 246
23, 227, 229
96

TOKIEDA Hiroshi
TOKUDA Makoto
TOMIDA Natsuki
TOMINAGA Daiki
TOMITA Hideki
TOMITA Masanori
TOOHEY Matthew
TORIKAI EikoTORRESI Domenico
TOUCHI Yutaka
TOYOMURA Keigo
TOYOSHIMA Atsushi
TSANG Manyee Betty
TSCHEUSCHNER Joachim
TSHOO Kyoungho
TSUBOTA Junichi
TSUBOTA Masakatsu
TSUJI Tomoya
TSUKADA Kazuaki
TSUKADA Kyo
TSUKADA Teruyo
TSUKIHANA Tomohiro
TSUKIORI Noritoshi
TSUMURA Miho
TSUNEIZUMI Kazuhide
TSUNODA Naofumi
TSURU Teruaki
TSURUMA Shizuho
TSUTO Shohei
TSUTSUMI Kenji
TUFF Adam GarryTÜRLER Andreas
TZOGANIS Vasileios

7, 21, 51, 54, 55, 56, 57, 58, 59, 60, 203, 217
124
244
64, 65223302
167275, 276
66
188
287
26, 279, 281, 282, 283, 284, 285
205, 206
38, 39, 41
31, 3221, 38, 39, 41, 51, 52, 54, 203
220
118
26, 281, 282, 283
23, 227, 228, 230
302
221, 222
19, 327, 331
7, 55, 211
303
9623, 227, 228, 230
328
279, 285, 292, 293
257
42, 44, 45
26, 282
185

U
UCHIYAMA Akito
UEDA Masashi
UEMATSU Haruko
UEMOTO Ryuji
UENO Hideki
UENO Shingo
UESAKA Tomohiro
UGAJIN Tomonori
UHLIG Jens
ULLOM Joel
UMEGAKI Izumi
URATA Yoshiharu
USOLTSEV IlyaUSUDATE Naoko
UTSUGI Megumi
UTSUNO Yutaka
UWAMINO Yoshitomo

194, 195, 237, 326, 327, 331
289, 290
223
240
8, 64, 65, 76, 125, 223, 251, 255, 319, 320
281
5, 7, 21, 24, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59,
60, 202, 203, 218, 219, 221, 222, 224, 232, 235
153
12
12
274
221, 222
26, 282323
316
36, 89, 96
323

V
VAJTA Zsolt
VALIENTE-DOBÓN Jose Javier
VAN DUPPEN PietVAN HULSE Charlotte
VANDEBROUCK Marine
VASCON Alessio
VI Phong
VOSSEN Anselm

3, 5, 33, 34, 35, 40, 54
35, 37233
108
42, 44, 45
283
35
108

W
WADA Michiharu
WADA Satoshi
WADA Yasumori
WADA Yasutaka
WAKABAYASHI Yasuo
WAKASA Tomotsugu
WAKASUGI Masanori
WAKITANI Yuichiro
WAKUI Takashi
WALKER Philip
WANG HeWANG Yang
WANG Zhimin
WASHIYAMA Kouhei
WATANABE Daisuke
WATANABE Hiroshi
WATANABE Isao
WATANABE Shu
WATANABE Takao
WATANABE Tamaki
WATANABE Yasushi
WATANABE Yukinobu

8, 22, 213, 216, 225, 226, 233
125, 221, 222
235
50
26, 66, 69, 70, 214, 215, 282, 293
21, 51, 54, 56, 57, 58, 203
23, 24, 193, 225, 227, 229, 231, 232
298, 299, 321
8, 56, 57
2, 35
4, 5, 6, 36, 37, 38, 39, 40, 41, 210
26, 28229
87
120
1, 2, 3, 27, 29, 30, 31, 32, 33, 34, 35
257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267,
268, 269, 270, 271, 272, 273, 274
326, 331
257
193, 326, 327, 331
6, 25, 248, 249
6

RIKEN Accel. Prog. Rep. 48 (2015)

WATANABE Yuni
WATANABE Yutaka
WATANABE Yutaka X.
WEICK Helmut
WERNER Volker
WIDMANN Eberhard
WIEHL Norbert
WIELAND Oliver
WIMMER Kathrin
WOLLNIK Hermann
WOODS Philip
WU JinWU Qiang
WYSOCKI Matt

217, 235, 236
19, 197, 233, 326, 327, 331
66, 234
235
3, 5
12
26, 282
38, 39, 41
38
22, 216, 226
247
3, 5, 29, 31, 32, 33, 34, 35, 40
2111

X
XU Furong
XU Xing-Liang
XU Zhengyu
XU Zhuan2262
1, 3, 5, 28, 29, 30, 31, 32, 33, 34, 35, 40
261, 266YYADOMI Kazuyoshi
YAGI Ayumi
YAGI Eiichi
YAKO Kentaro
YAKUSHEV Alexander
YAMADA Atsuo
YAMADA Kazunari
YAMADA Kohei
YAMADA Mieko
YAMADA Shinya
YAMADA Takahiro
YAMAGAMI Masayuki
YAMAGUCHI Hidetoshi
YAMAGUCHI Masahide
YAMAGUCHI Mitsutaka
YAMAGUCHI Takayuki
YAMAGUCHI Yasuhiro
YAMAGUCHI Yorito
YAMAGUCHI Yoshitaka
YAMAGUCHI Yuki
YAMAKA Shoichi
YAMAKAMI Hiroki
YAMAKI Sayaka
YAMAMOTO Hiroshi
YAMAMOTO Tetsuya
YAMASAWA Hideyuki
YAMASHITA Yuuichi
YAMAUCHI Hiromoto
YAMAUCHI Tomoya
YAMAUCHI Yoshiyuki
YAMAZAKI Hiroki
YAMAZAKI Tomokazu
YAMAZAKI Toshimitsu
YAMAZAKI Yasunori
YAMAZAWA Hisayuki
YANAGISAWA Yoshiyuki
YANG Lei
YANG Xiaofei
YANG Yan Yun
YANG Zaihong
YANO Satoshi
YANO Shinya
YASUDA Jumpei
YASUDA Shingo
YASUDA Yuki
YATSU Yukari
YEE Ho-Ung
YENNELLO Sherry J.
YOKKAICHI Satoshi
YOKOKITA Takuya
YOKOYAMA Akihiko
YOKOYAMA Koji
YOKOYAMA Makoto
YOKOYAMA Rin
YONEDA Akira
YONEDA Ken-ichiro
YONEYAMA Shunpei
YOON Inseok
YOON Sungwon
YOSHIDA Atsushi
YOSHIDA Kenichi
YOSHIDA Koichi
YOSHIDA Shinnosuke

19, 327, 331
3, 31, 32, 33, 34, 35, 71, 72
252
7, 21, 51, 54, 55, 56, 57, 58, 59, 60, 203, 220, 319
26, 282291
61, 187, 188, 193, 232, 237, 326, 327, 331
23, 227307
12, 17, 18, 179
298, 299
58, 8566, 67, 68, 240
158, 159
61
24, 215, 232
13012224, 231, 232
38, 59, 60
327, 331
235
26, 69, 70, 214, 215, 282, 293
255
40
19, 331309
188, 326254
323
64, 65, 253, 319
309
140, 141, 142
315
322
7, 9, 11, 55, 56, 57, 58, 59, 60, 61, 71, 72, 73, 74, 75, 235,
254
66
8, 25166
52
13298, 299, 321
21, 47, 48, 49, 51, 52, 54, 56, 57, 58, 202, 203
265
280
281
133
206
242, 248
280, 287, 293
281
275
259
7, 31, 32, 33, 34, 55, 56, 57, 58, 59, 60, 72
70
5, 8, 21, 36, 37, 38, 39, 40, 41, 42, 44, 45, 47, 48, 49, 50,
51, 52, 53, 54, 61, 62, 202, 203, 319, 320
23, 227, 228, 230
103, 106258, 273
239, 240, 254, 321
84
9, 11, 25, 56, 57, 58, 59, 60, 71, 72, 73, 74, 75, 220, 225,
235, 254, 330
35

AUTHOR INDEXYOSHIDA Toru
YOSHIKAWA Akifumi
YOSHIMI Akihiro
YOSHIMURA Takashi
YOSHINAGA Kenta
YOSHINAGA Naotaka
YUASA Takayuki
YUSA Akira

252
18, 172, 177, 179, 180
255
287
3, 25
92, 93
171, 172
188, 326

Z
ZEGERS Remco
ZENIHIRO Juzo
ZHANG Chengjie
ZHANG Guangxin
ZHANG QiZHENG Xu-GuangZHOU BoZHOU Shan-Gui
ZILGES AndreasZMESKAL Johann

21, 51, 203
21, 38, 39, 47, 48, 49, 50, 51, 52, 54, 56, 57, 58, 202, 203,
211, 217, 232
160, 161
35
124
262
99
94
39
12

国立研究開発法人理化学研究所

埼玉県 和光市 広沢
RIKEN 2015-047