RIKEN
Accelerator
Progress Report

2006
vol.

40

BOOK & CD−ROM
独立行政法人理化学研究所 仁科加速器研究センター
RIKEN Nishina Center for Accelerator-Based Science

CONTENTS
Page
FRONTISPIECERIBF project passes a critical milestone: the extraction of the ﬁrst beam from SRC
Status of BigRIPS separator project
HIGHLIGHTS OF THE YEAR

Role of the tensor correlation on the halo formation in 11 Li . . . . . . . . . . . . . . . . . . . . . . . . . . .

iProton inelastic scattering on neutron-rich nuclei 60 Cr and 62 Cr . . . . . . . . . . . . . . . . . . . . . . .

ii

Small electric quadrupole moment of neutron-rich 32 Al . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iiiMedium modi cation for ρ, ω mesons in 12 GeV p+A reactions . . . . . . . . . . . . . . . . . . . . . . . .

iv

Ferromagnetic and charge transfer phase transitions in [FeII FeIII (dto)3 ] (dto = C2 O2 S2 )complexes examined by muon spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

v

I.

PREFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1

II.

RESEARCH ACTIVITIES I (Nuclear-Particle Physics)

1. Nuclear Physics
Diﬀerential cross sections of the proton inelastic scattering on 32 Mg . . . . . . . . . . . . . . . . . . .

5Lifetime measurement of the ﬁrst 2+ state of 32 Mg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6

Proton inelastic scattering studies at the borders of the “island of inversion”:
The 30,31 Na and 33,34 Mg case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7

Proton inelastic scattering on very neutron-rich 36 Mg nucleus . . . . . . . . . . . . . . . . . . . . . . . . .

8Study of ﬁrst excited state in 30 Ne by proton inelastic scattering in reverse
kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9Proton single-particle states in neutron-rich 23 F nucleus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10

Vanishing N = 20 shell gap: study of excited states in 27,28 Ne . . . . . . . . . . . . . . . . . . . . . . . . .

11Electric quadrupole moment of 31 Al . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12

Test experiment on 32m Al isomeric moment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13

Direct capture component in 26 Si(p, γ)27 P reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14Study of astrophysically important resonant states in 26 Si by 28 Si(4 He,6 He)26 Si
reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15

Cluster structures of even-even oxygen isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16

Search for neutron decoupling in 22 O via (d, d’γ) reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17

Proton elastic scattering from light unstable nuclei at intermediate energies . . . . . . . . . . .

18β-decay study of C, N, O isotopes near neutron drip line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19

Reaction cross sections for 19 C, 20 C and 22 C on proton target . . . . . . . . . . . . . . . . . . . . . . . . .

20

Search for extremely neutron-rich systems 7 H, 6 H and 4 n in the 2 H + 8 He collisions . . .

21

Research on correlated two-nucleon system in 6 Li and 6 He nuclei . . . . . . . . . . . . . . . . . . . . . .

22

Coulomb dissociation of 6 He . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23

Analyzing Power Measurement for the Proton Elastic Scattering on 6 He at
71 A MeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24

Elastic Scattering of 8 B on Pb, Liquid H2 and Liquid He Targets . . . . . . . . . . . . . . . . . . . . . .

25

14 Be(p, n)14 B(1+ ; 1.28 MeV) reaction at 70 MeV/nucleon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

Invariant-mass spectroscopy of 13 Be and 14 Be . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27

Resonance levels in 14 O near the 13 N + p threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28

Proton resonance scattering of 7 Be . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29

In-beam γ-ray measurement using 20 Ne + 96 Zr reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

Study of high-spin states in 49–51 Ti by secondary fusion reaction . . . . . . . . . . . . . . . . . . . . . . .

31

Low-energy 46 Ar beam for secondary reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

32

Development of secondary beams produced by fusion reactions for β-decay
measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

33

Production of low-energy polarized radioactive beams using CRIB . . . . . . . . . . . . . . . . . . . .

34

Electron scattering from unstable nuclei by the SCRIT method (III) . . . . . . . . . . . . . . . . . .

35

Electron scattering oﬀ wire targets in SCRIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36

Laser spectroscopy of 7,10 Be+ in an online ion trap at SLOWRI . . . . . . . . . . . . . . . . . . . . . . .

37

Pumping 229m Th by hollow-cathode discharge [IV] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

38

Dependence on ortho-para D2 ratio of ddµ formation rate in muon-catalyzed fusion . . .

39

Temperature dependence of muon transfer reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40Muon Transfer Reaction Studies in Solid Deuterium Films with Implanted Ions . . . . . . .

41

2. Nuclear Physics (Theory)
Coulomb breakup eﬀects on elastic cross section of 6 He + 209 Bi scattering near
Coulomb barrier energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

43

Nonadiabatic dynamics in 10 Be with α + α + N + N model . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

α + 12 C inelastic angular distribution and nuclear size of 12 C(02 + ) . . . . . . . . . . . . . . . . . . . .

45

Cluster states in 13 C(1/23 − ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46

Fusion reaction of 15 C + 144 Sm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47

An s-wave halo structure of 22 C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

48

Systematic analysis of reaction cross sections of carbon isotopes . . . . . . . . . . . . . . . . . . . . . . .

49

Study of the tensor correlation in 17 O using the shell model . . . . . . . . . . . . . . . . . . . . . . . . . . .

50

Exotic structure of unstable nuclei around N = 28 due to tensor force . . . . . . . . . . . . . . . . .

51

Eﬀective interaction for f5pg9-shell nuclei and two-neutrino double-beta-decay
matrix elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

52

Rotational motion in weakly bound superﬂuid nuclei . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

53

Conﬁguration mixing calculation for complete low-lying spectra with themean-ﬁeld Hamiltonian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

54

Quadrupole-coupling model for doublet bands in doubly odd nuclei . . . . . . . . . . . . . . . . . . .

55

Tilted-axis rotation and wobbling motion on 3D-CHFB states . . . . . . . . . . . . . . . . . . . . . . . . .

56

Thermal pairing in Richardson model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

57

Consistency of particle-particle random-phase approximation and renormalization . . . . .

58

Self-Consistent Quasiparticle RPA for Multi-Level Pairing Model . . . . . . . . . . . . . . . . . . . . . .

59

Formula for proton-nucleus reaction cross section at intermediate energies andits application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

60

More Accurate Estimation of Ground-State Energy and Spin-Zero Dominance . . . . . . . . .

61

Fusion Hindrance Due to One-Body Penetration at Deep Sub-Barrier Energies for
64 Ni + 64 Ni . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

62

Late-time supernova evolution induced by anisotropic neutrino radiation andr-process environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

63

3. Hadron Physics
Estimation of the in-medium modiﬁcation parameters for φ meson . . . . . . . . . . . . . . . . . . . .

65

Nuclear mass number dependence of φ-meson production in the e+ e− and K+ K−
decay channels studied in 12 GeV p + A reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

66

Proposed spectrometer for electron pair measurement at J-PARC 50-GeV PS . . . . . . . . .

67

Search for Θ+ via K+ p → π + X reaction at KEK-PS E559 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

68

Measurement√of high-pT Single Electrons from Heavy-Flavor Decays in p + pCollisions at s = 200 GeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

69

Heavy Quark Measurement by Single Electrons in Au + Au Collisions . . . . . . . . . . . . . . . . .
√J/ψ → e+ e− Measurements in Au + Au Collisions at S NN = 200 GeV by
RHIC-PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
√PHENIX measurements on J/ψ production in s = 200 GeV p + p collisions . . . . . . . . . .
√Measurement of High-pT Direct Photons in S NN = 200 GeV Au + Au Collisions
at RHIC-PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
√Elliptic ﬂow of electrons from heavy ﬂavor decay in S NN = 200 GeV Au + Au
collisions at RHIC-PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Measurement of Double-Helicity Asymmetry in Multiparticle Production from
Polarized Proton-Proton Collision at PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
√Direct photon production in p + p at s = 200 GeV, and its double spin
asymmetry measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70
71
72
73
74
75
76

Measurement√of the mid-rapidity double helicity asymmetry of η mesons in p + p
collisions at s = 200 GeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

77

Accessing the Gluon Polarization through π ± ALL at PHENIX . . . . . . . . . . . . . . . . . . . . . . . . .

78

0
Double√ Helicity Asymmetry of Inclusive π Production in Polarized pp Collisions
at s = 62.4 GeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

79

Measurement of Double Helicity Asymmetry in π 0 Production in Polarized Proton
Collisions at PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

80

Measurement of Double Transverse Spin Asymmetry in π 0 Production in Transversely
Polarized Proton Collisions at PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

81

kT Asymmetry in Longitudinally Polarized pp Collisions at PHENIX . . . . . . . . . . . . . . . . .

82

Measurement√of Transverse Single-spin Asymmetries with J/ψ in Polarized p + pCollisions at s = 200 GeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

83

Measurement of cross section and single transverse spin asymmetry of forward neutrons
from pp collisions at RHIC-PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

84

Spin-dependent fragmentation function measurements at Belle experiment . . . . . . . . . . . .

85

Measurement of AN and ANN in pp Elastic Scattering in the CNI Region with a
Polarized Atomic Hydrogen Gas Jet Target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

86

Absolute beam polarization measurements at RHIC in 2005 . . . . . . . . . . . . . . . . . . . . . . . . . . .

87

Stability for Run05 Operation of pC-Polarimeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

88

Absolute luminosity determination using vernier scan technique at PHENIX . . . . . . . . . .

89

Data production for RHIC-PHENIX experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

90Development of Nose Cone Calorimeter in PHENIX Forward Region . . . . . . . . . . . . . . . . . .

91

Development of a Trigger for High-pT Charged Pions for the PHENIX Detector at
RHIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

92

4. Hadron Physics (Theory)
Spin dependent structure functions of ﬁnite nuclei . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

93

Color superconductivity and neutron star structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

94

Isospin breaking on baryons with Nf = 2 domain wall fermions . . . . . . . . . . . . . . . . . . . . . . . .

95

Initial Singularity in the Little Bang . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

96

Heavy Quarkonium States in a Gluon Plasma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

97

Nucleon structure in lattice QCD with dynamical domain-wall fermions . . . . . . . . . . . . . . .

98

Finite temperature transition in three ﬂavor QCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

99

5. Particle Physics
Automatic O(a) improvement for twisted-mass QCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

101

Proton decay matrix elements with Nf = 0 and 2 domain-wall QCD . . . . . . . . . . . . . . . . . . .

102

Lattice QCD with dynamical overlap fermions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

103

Overlap lattice fermion in a gravitational ﬁeld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

104

Gauge anomaly associated with the Majorana fermion in 8k + 1 dimensions . . . . . . . . . . .

105

Note on massless bosonic states in two-dimensional ﬁeld theories . . . . . . . . . . . . . . . . . . . . . .

106

Hermiticity and Majorana condition for two-dimensional super Yang-Mills model on alattice with Dirac-Kähler twist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

107

Nonlocal Matching Condition and Scale-invariant Spectrum in Bouncing Cosmology . . .

108

Field Equations of Massless Fields Based on the New Interpretation of Matrix
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

109

Improved perturbation method and its application to matrix models . . . . . . . . . . . . . . . . . .

110

Non-Abelian duality from vortex moduli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

111

QCD Eﬀects in the Decays of TeV Black Holes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

112

Towards Full Automation of the Lepton g − 2 Calculation in QED . . . . . . . . . . . . . . . . . . . .

113

Transverse double spin asymmetries in dimuon production at small QT in pp and pp̄
collision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

114

Towards a global analysis of polarized parton densities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

115

6. Development of Accelerator Facility
Production of U beam from RIKEN 18 GHz ECRIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

117

Design of superconducting magnet system for RIKEN 28 GHz SC-ECR ion source . . . . .

118

Control System for RIKEN Accelerator Research Facility and RIKEN RI-Beam
Factory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

120

Development of Beam Phase Measurement System using Lock-In Ampliﬁer for
RARF/RIBF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

122

Study of New Flat-Top Resonator for RRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

124Construction of Rebuncher for fRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

126

Preparation of polymer coating carbon stripper foils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

128

Rotating cylinder charge stripper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

130

Measurements of beam energy and longitudinal beam proﬁle using plastic scintillation
monitors for RIBF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

131

Development of new HTS current sensor and HTS magnetic shields for HTS-SQUID
monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

133

Construction of vacuum pumping system for RIBF beam transport line . . . . . . . . . . . . . . .

135

Status of the SRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

137

Present Status of Liquid-Helium Supply and Recovery System . . . . . . . . . . . . . . . . . . . . . . . .

138

New Energy Establishment Committee of Wako City District and RIBF . . . . . . . . . . . . . .

139

Spin mismatch of the AGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

140

Laser based heavy ion production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

141

Aluminum beam acceleration with DPIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

142

7. Instrumentation
Development of ion-guiding system for RIABR experiments . . . . . . . . . . . . . . . . . . . . . . . . . . .

145

Improvement of slow RI beam transport using carbon-OPIG . . . . . . . . . . . . . . . . . . . . . . . . . .

147

Status of Rare RI–Ring project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

148

A multireﬂection time-of-ﬂight mass spectrometer using cryogenic linear ion trap for
injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

150

Calibration Test of Space Radiation Measurement Instruments . . . . . . . . . . . . . . . . . . . . . . . .

152

High-Resolution Beam Line for SHARAQ Spectrometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

153

High-resolution SHARAQ spectrometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

155

Developments of multiwire drift chambers for SHARAQ beamline . . . . . . . . . . . . . . . . . . . . .

157

Preparation of the self-supporting boron target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

159

Development of solid hydrogen target for ESPRI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

161

Development of the recoil ion detector for SCRIT experiment . . . . . . . . . . . . . . . . . . . . . . . . .

162

New method of polarization reversal using 180-deg pulse nuclear magnetic resonance . .

163

Scintillation ﬁber detector for momentum analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

165

A collinear fast beam laser spectroscopy apparatus for Ni isotopes . . . . . . . . . . . . . . . . . . . .

166

Development of a Mott polarimeter for T-violation experiment . . . . . . . . . . . . . . . . . . . . . . . .

167

PHENIX silicon vertex tracker project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

168

Status overview status of Silicon Pixel detector for PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . .

170

Silicon pixel detector assembly procedure for PHENIX upgrade . . . . . . . . . . . . . . . . . . . . . . .

171

Phenix VTX Tracker Upgrade: Stripixel Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

173

Radiation Damage Study of Silicon Stripixel Sensor at the PHENIX Interaction
Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

174

Development of PHENIX Silicon Pixel Interface ReadOut (SPIRO) Module . . . . . . . . . . .

176

Quality assurance test of readout chips and pixel sensor hybrids for PHENIX . . . . . . . . .

178

Cosmic-ray experiment with PHENIX silicon pixel sensor hybrids . . . . . . . . . . . . . . . . . . . . .

180

Overview of the Readout Electronics for the Silicon Vertex Tracker for the PHENIX
Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

182

Development of ampliﬁer-discriminator readout system of cathode strip chamber formuon trigger upgrade at RHIC PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

184

Development of pixel readout bus for PHENIX upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

186

Beam Test of Stripixel Si Sensor for Radiation Damage Study . . . . . . . . . . . . . . . . . . . . . . . . .

188

Fluence Measurement for Radiation Damage Study of Silicon Stripixel Sensor . . . . . . . . .

190

PHENIX reaction plane detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

192

Ubiquitous detector system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

193

Development of FADC unit for UBIQUITOUS detector system . . . . . . . . . . . . . . . . . . . . . . . .

195

CCJ operation in 2005–2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

197

Network and Computing Enviroment for RIKEN Nishina Center . . . . . . . . . . . . . . . . . . . . . .

199

III.

RESEARCH ACTIVITIES II (Material Science and Biology)

1. Atomic and Solid State Physics (ions)Comparison of Single-Event Burnout tolerance of space-use power MOSFETs . . . . . . . . .

201

Synthesis of Pd-Au nanoparticles by GeV ion irradiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

202

57 Fe diﬀusion in Si after GeV – implantation of 57 Mn.................................

203...................................

204

Continuum luminescence of α-alumina under heavy-ion irradiation . . . . . . . . . . . . . . . . . . . .

205

Ultra-short-pulse continuum of ion track: Release of spectral missing in alkali halides . .

206

Displaced-T site occupancy of hydrogen in Nb alloyed with a high concentration of
Mo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

207

Production of microbeam of slow highly charged ions with tapered glass capillary . . . . .

209

Auger electrons from excited N ions after passing through Ni microcapillaries . . . . . . . . .

211

Hyperﬁne structure of Rb and Cs atoms in superﬂuid helium . . . . . . . . . . . . . . . . . . . . . . . . . .

212

Precise measurement of the hyperﬁne splitting of Cs atoms in superﬂuid helium . . . . . . .

213

Properties of laser ablation plasma generated by high power Nd:YAG laser . . . . . . . . . . . .

214

Time-delay matrix analaysis of several overlapping resonances . . . . . . . . . . . . . . . . . . . . . . . . .

215

99 Ru Mössbauer spectroscopic studies of SmRu P
4 12

2. Atomic and Solid State Physics (muon)µSR study of the impurity eﬀects on the Cu-spin ﬂuctuations in the overdoped
La2 –x Srx Cu1–y Zny O4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

217µSR study of the impurity eﬀects on Cu-spin ﬂuctuations in electron-doped high-Tc
superconductor Pr0.86 LaCe0.14 Cu1–y Zny O4+α−δ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

218µSR study of impurity eﬀects on Cu-spin dynamics and superconductivity in
La2 -x Srx Cu1 -y (Zn,Ni)y O4 with x = 0.15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

219

Cu-Spin Dynamics Studied by µSR in La2–x Srx CuO4 at about 100 K . . . . . . . . . . . . . . . . . .

220

Magnetism of lightly doped Ca2–x Nax CuO2 Br2 probed by µSR . . . . . . . . . . . . . . . . . . . . . . . .

221µSR study of the localized spin triplets in TI1–x Kx CuCl3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

222µSR study of the randomness-induced new magnetic phase in Tl(Cu1–x Mgx )Cl3 . . . . . . .

223

Magnetic ordering in solid solution of two spin gap systems (CH3 )2 CHNH3 CuCl3 and(CH3 )2 CHNH3 CuBr3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

224µSR studies of sulfospinel CuCrZrS4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

225

Magnetic preperties of S = 1/2 quantum spin system on a Kagomé lattice
Cu-titmb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

226µSR study on spin dynamics of Mn2 lll -Nill Single-Chain Magnet . . . . . . . . . . . . . . . . . . . . . . .

227µSR studies of the ground state of a new spin-ladder material . . . . . . . . . . . . . . . . . . . . . . . . .

228µSR study of ferromagnetic ﬁlled skutterudite compound SmFe4 P12 . . . . . . . . . . . . . . . . . . .

229

Possible octupolar order in ﬁlled skutterudite SmRu4 P12 probed by muon spin
relaxation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

230

µSR study of ferrimagnetism on K clusters in low-silica X zeolite . . . . . . . . . . . . . . . . . . . . . .

231µSR study on nano sized cage material, 12CaO·7Al2 O3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

232

Eﬀects of molecular adsorption on magnetism of edge state spins in nanographite . . . . .

233µSR Study of CDW in Potassium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

234

Muon spin resonance study of shallow muonium in ZnO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

235

Positive muons in calcium phosphate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

236

RF-µ− SR on Si . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

237µSR studies on a thin Nd0.5 Sr0.5 MnO3 ﬁlm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

238

Deveropment of Gas-Pressurized Cell for Higt-Pressure µSR Experiments at the
RIKEN-RAL Muon Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

239

3. Radiochemistry and Nuclear Chemistry
Performance of Gas-Jet Transport System Coupled to GARIS . . . . . . . . . . . . . . . . . . . . . . . . .

241

Heavy element production for chemical characterization of seaborgium . . . . . . . . . . . . . . . .

242

Preparation of 83 Rb for 83 Kr Mössbauer Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

243

Reactions of 57 Mn Implanted into Solid Oxygen at γ-Phase . . . . . . . . . . . . . . . . . . . . . . . . . . .

244

The Distribution and Metabolism of 14 C–labelled Carnosine in Mice . . . . . . . . . . . . . . . . . .

245

Eﬀect of carnosine on gastric secretion in rats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

246

Rapid solvent extraction of No2+ with multitrack microchips . . . . . . . . . . . . . . . . . . . . . . . . . .

248

4. Radiation Chemistry and Biology
Lack of phosphorylated histone H2AX in the pericentric heterochromatin . . . . . . . . . . . . .

249

Eﬀect of DNA-PK inhibitors on the cellular sensitivity to heavy ions . . . . . . . . . . . . . . . . . .

250

Heavy ion irradiation of human cultured cells: The irradiated medium can reduce therate of spontaneously induced mutations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

251

Mutation induction by heavy-ion irradiation in Cyanidioschyzon merolae 10D . . . . . . . . .

252

Isolation of salt-tolerant mutants of rice induced by heavy-ion irradiation . . . . . . . . . . . . .

253

Isolation of inﬂorescence mutants induced by heavy-ion radiation in barley (Hordeum
vulgare L.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

254

Mutation induction by heavy-ion beam irradiation in tartary buckwheat . . . . . . . . . . . . . .

255

Eﬀects of carbon-ion beam irradiation on plant growth and mutation induction in
Nicotiana tabacum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

256

Establishment of sex identiﬁcation method and eﬀect of N-ion beam irradiation in
dioecious plant Carica papaya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

257

Floral and sexual mutants yielded by C-ion beam irradiation on the dioecious plant
Silene latifolia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

258

Eﬀect of ion beam irradiation in Chinese chive (Allium ramosum L.) . . . . . . . . . . . . . . . . . .

259

Floral Color Mutations Derived from Heavy-Ion Beam irradiation in a Torenia
Cultivar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

260

Induction of ﬂower mutant by heavy-ion beam irradiation of cyclamen . . . . . . . . . . . . . . . .

261

5. Material Analysis

IV.

V.

Proton conducting polymer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

263

Muon diﬀusion in lithium battery materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

264

Operation Records

RILAC operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

265

RRC operation and beam line construction for RIBF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

267

AVF operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

268

Routine Work for Radiation Safety in Ring Cyclotron Facility . . . . . . . . . . . . . . . . . . . . . . . . .

269

Operation of the tandem accelerator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

271

RECORDS OF LABORATORIES, GROUPS, AND TEAMS(Acitivity summaries and lists of personnel)
Events in Nishina Center in Fiscal 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

273

Accelerator Division
Accelerator Development Group
Accelerator Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

274

Ion Source Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

276

Accelerator Operation GroupRILAC Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

277

Cyclotron Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

278

Beam Technology Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

279

Cryogenic Technology Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

280

Nuclear Physics Research Division
Heavy Ion Nuclear Physics Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

281

Applied Nuclear Physics Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

289

Radioactive Isotope Physics Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

293

Superheavy Element Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

296

Experimental Installations Development GroupSLOWRI Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

298

R&D team for multipartical spectrometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

300

Polarized RI Beam Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

301

Rare RI-ring Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

303

SCRIT Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

304

Experimental Installations Operation GroupGARIS Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

305

BigRIPS Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

306

Computing and Network Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

307

Detector Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

308

User Liaison and Support Division
User Liaison and Support Group
User Support Oﬃce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

309

Experiment Support Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

310

Industrial Cooperation Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

311

Sub Nuclear System Research Division
Radiation Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

312

Advanced Meson Science Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

317

Theoretical Physics Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

322

Accelerator Applications Research Division
Accelerator Applications Research Group
Radiation Biology Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

325

RI Applications Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

328

RIKEN BNL Research Center
Experimental Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

331

Theory Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

333

VI.

LIST OF PUBLICATIONS & PRESENTATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

337

VII.

LIST OF PREPRINTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

379

VIII.

LIST OF SYMPOSIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

381

IX.

LIST OF SEMINARS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

383

X.

AUTHOR INDEXRIKEN Accel. Prog. Rep. 40 (2007)

Role of the tensor correlation on the halo formation in 11 Li
T. Myo,∗1 K. Katō,∗2 H. Toki,∗1 and K. Ikeda

A pioneering secondary-beam experiment found thatthe size of 11 Li was surprisingly large, which was outside of the common sense of Nuclear Physics1) . Thislarge size was interpreted as the halo structure of two
neutrons around 9 Li. Many experimental findings wereshown later for 11 Li: a) The halo neutrons have almost
equal amount of the s-wave component with respect
to the p-wave one2) . b) The E1 strength distribution
has a large enhancement near the threshold3) . c) The
charge radius is larger than that of 9 Li4) .
The biggest puzzle from the theory side is the larges-wave component for the halo neutrons. If we interpret this fact in the shell model, the shell gap at N = 8
has to disappear. However, the mean field treatment ofa central force is not able to provide the disappearanceof the N = 8 shell gap. Essentially all the theoreticalworks of 11 Li had to accept that the 1s1/2 single particle state is brought down to the 0p1/2 state without
knowing its reason. It is the real challenge for theoretician to understand this disappearance of the N = 8
shell gap, which is worked out in this report by developing a framework to treat the tensor force explicitly
in the nucleon-nucleon interaction.
The tensor correlation was demonstrated importantin the 4 He+n system5) . We treated there the tensor force in the shell model basis with 2p2h excitations, and found that the (0s1/2 )−2 (0p1/2 )2 of protonneutron pair is important to describe the tensor correlation in 4 He5) . This 2p2h excitation causes the Pauliblocking in the 4 He+n system for the p1/2 -orbit, which
contributes to the p-wave splitting5) . Hence, it is important to study the effect of the tensor correlationon the N = 8 shell gap problem in 11 Li. This is the
purpose of this study. We shall perform the configuration mixing with the shell model framework for 9 Li todescribe the tensor correlation explicitly. For 11 Li, we
solve the coupled 9 Li+n+n problem.
We base on the effective interaction GA0 for 9 Li,
which has explicitly the tensor force applying the AV80
potential from the G-matrix theory5,6) . For 9 Li+n+n
system, the 9 Li-n potential is given by folding potential
7), which strength is determined to reproduce the twoneutron-separation energy of 11 Li as 0.31 MeV. For thelast two neutrons, we take an AV80 potential.
For 9 Li, in addition to the 0p0h state, (0s1/2 )−2 (0p1/2 )22p2h excitation of proton-neutron pair caused by thetensor correlations are strongly mixed with 8.2%.
Here, let us add two neutrons more to 9 Li. When two∗1∗2

Research Center for Nuclear Physics, Osaka University
Graduate School of Science, Hokkaido University-i-dσ/dE [b/MeV][Nuclear structure, Unstable nuclei, Tensor force, Cluster model]
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0

Present
RIKEN

0

1

2

3

4

Energy [MeV]Fig. 1. Calculated Coulomb breakup cross section measured from the 9 Li+n+n threshold energy.

neutrons occupy the 0p1/2 -orbit the 2p2h excitationsof the tensor correlation in 9 Li are Pauli-blocked5,7) .
Accordingly, the correlation energy of 9 Li is lost inside
11
Li. For the (1s)2 case of two neutrons, the Pauliblocking does not occur and 9 Li gains its correlationenergy fully with the 2p2h excitations. Hence, the energy distance between (0p)2 and (1s)2 configurationsof 11 Li is expected to become small.
We perform the coupled three-body calculation of
11
Li with tensor correlations. Our solutions give alarge (1s)2 probability of 46.9% for the last two neutrons and a large matter radius, 3.41 fm for 11 Li,
which are enough to explain the observations. Thismeans that the blocking effect from the tensor correlation is essential to break the magicity and make thehalo structure for 11 Li. The probabilities of (p1/2 )2 ,(d5/2 )2 and (d3/2 )2 for the last two neutrons are given
as 42.7%, 4.1% and 1.9%, respectively.
We calculate the Coulomb breakup strength of 11 Li
into 9 Li+n+n system in comparison with the newdata3) . In Fig. 1, it is found that the present model reproduces the experiment, in particular, for low energy
enhancement and its magnitude. The charge radius of11
Li was measured recently and its value is 2.467(37)fm, enhanced from the one of 9 Li, 2.217(35) fm4) . The
present model provide 2.44fm and 2.23fm, respectively,
which are in good agreement with the experimental
values. This enhancement is caused by the large distance between 9 Li and the paired 2n as 5.69 fm.
References
1) I. Tanihata et al.: Phys. Rev. Lett. 55, 2676 (1985).
2) H. Simon et al.: Phys. Rev. Lett. 83, 496 (1999).
3) T. Nakamura et al.: Phys. Rev. Lett. 96, 252502 (2006).
4) R. Sánchez et al.: Phys. Rev. Lett. 96 033002 (2006).
5) T. Myo et al.: Prog. Theor. Phys. 113, 763 (2005).
6) Y. Akaishi : Nucl. Phys. A 738, 80 (2004).
7) T. Myo et al.: Prog. Theor. Phys. 108, 133 (2002).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Proton inelastic scattering on neutron-rich nuclei 60 Cr and 62 Cr
E. Takeshita,∗1 N. Aoi, S. Ota,∗2 S. Takeuchi, H. Suzuki,∗3 H. Baba,∗4 S. Bishop, T. Fukui,∗2 Y. Hashimoto,∗5
E. Ideguchi,∗4 K. Ieki,∗1 N. Imai,∗6 H. Iwasaki,∗3 S. Kanno,∗1 Y. Kondo,∗5 T. Kubo, K. Kurita,∗1 K. Kusaka,
T. Minemura,∗6 T. Motobayashi, T. Nakabayashi,∗5 T. Nakamura,∗5 T. Nakao,∗3 M. Niikura,∗4 T. Okumura,∗5
H. J. Ong,∗3 T. K. Onishi,∗3 H. Sakurai,∗3 S. Shimoura,∗4 R. Sugo,∗1 D. Suzuki,∗3 M. K. Suzuki,∗3
M. Tamaki,∗4 K. Tanaka, Y. Togano,∗1 and K. Yamada£¤
NUCLEAR STRUCTURE, 60,62 Cr(p,p0 γ), Inelastic scattering, Unstable nuclei
62
Neutron-rich nuclei 60
24 Cr36 and 24 Cr38 are suggested
to have a large deformation, because their first 2+ energies are significantly lower than those of the neighboring isotopes.1) In the present work, the nature of collectivity in 60 Cr and 62 Cr was further studied through+their 2+
1 and 41 states using proton inelastic scattering.
The experiment was performed using secondary 60 Cr
and 62 Cr beams produced at RIPS.2) Proton inelastic
scattering was observed in inverse kinematics by γspectroscopy. The experimental details are describedin Ref.3) . Figure 1(a) shows a γ-ray spectrum measured in coincidence with inelastically scattered 60 Cr.
Two peaks are seen at approximately 650 keV and+
820 keV, which are consistent with the 2+
1 →0g.s. and++41 →21 transitions observed in a previous work.4)
From the γ-ray yield, the angle-integrated cross section+
for the 0+
g.s. →21 transition was obtained. The deformation parameter β2 for 60 Cr was then deduced from
DWBA analysis to be 0.37(5). A similar analysis was
performed for 62 Cr and β2 was obtained to be 0.38(3).
These values are significantly larger than those ofneighboring 56 Cr and 58 Cr obtained by Coulomb excitation (0.195(34), 0.254(36), respectively).5) The large
β2 values observed indicate that the collectivity in theneutron-rich Cr isotopes is enhanced as the neutron
number increases toward N ∼ 40, which is consistent
with the rapid drop in the 2+
1 energy systematics.
The cascade relation of γ rays at 820 keV and 650
keV was examined by γ-γ coincidence analysis. The γray spectrum for 60 Cr obtained in coincidence with a
646-keV γ ray is shown in Fig. 1(b). The γ-ray peak at
820 keV is clearly seen showing that the 820-keV transition coincides with the 650-keV transition. A peakat approximately 650 keV is seen due to contaminationof the compton scattering component of the 820-keV γ
ray in the 650-keV γ-ray gate. The coincidence of two
transitions indicates that the 820-keV transition populates the 2+
1 state. This interpretation supports the+4+→2
assignment
to the 817-keV transition obtained
1
1+
in Ref.4) . The energy ratio Ex (4+1 )/Ex (21 ) = 2.3 sug∗1
∗2
∗3
∗4
∗5
∗6

gests that the surface vibration picture is more appropriate for the collectivity of 60 Cr rather than therotation of a well-deformed nucleus.
The result exhibits the feasibility of the experimental
study of the 4+
1 state by proton inelastic scattering
using fast secondary beams. The determination of the62
4+
Cr is in progress to explore the region
1 energy inof large collectivity.

Fig. 1. (a) Gamma-ray energy spectrum obtained in coincidence with 60 Cr. (b) γ-γ spectrum in coincidence with+2+
1 →0g.s. γ rays.

References
1) O. Sorlin et al.: Eur. Phys. J. A 16, 55 (2003).
2) T. Kubo et al.: Nucl. Inst. Meth. B 70, 309 (1992).
3) E. Takeshita et al.: RIKEN Accel. Prog. Rep. 39, 71(2006).
4) N. Mărginean et al.: Phys. Lett. B 633, 696 (2006).
5) A. Bürger et al.: Phys. Lett. B 622, 29 (2005).

Department of Physics, Rikkyo University
Department of Physics, Kyoto University
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
Department of Physics, Tokyo Institute of Technology
KEK- ii -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Small electric quadrupole moment of neutron-rich 32 Al
D. Kameda, H. Ueno, K. Asahi, M. Takemura,∗1 A. Yoshimi, T. Haseyama,∗1 M. Uchida,∗1 K. Shimada,∗1
D. Nagae,∗1 G. Kijima,∗1 T. Arai,∗1 K. Takase,∗1 S. Suda,∗1 T. Inoue,∗1 J. Murata,∗2 H. Kawamura,∗2
Y. Kobayashi, H. Watanabe,∗3 and M. Ishihara[Nuclear structure, polarized RI beam, nuclear moments]

∗1
∗2
∗3

Department of Physics, Tokyo Institute of Technology
Department of Physics, Rikkyo University
Department of Nuclear Physics, The Australian National
University- iii -

clearly indicates the spherical sd-shell nature of theground state of 32 Al. The small Q moment probably
stemmed from a major part of the configurations ofπ+
32
Al, |(πd5/2 )−1 ⊗ (νd3/2 )−1 iI =1 , which possesses asmall Q moment. The result is in sharp contrast to
the large degree of deformation of 31 Mg due to the
pf -intruder structure5) , suggesting a sudden change inshell structures between the adjacent N = 19 isotones.

β-ray asymmetry change (%)

3.2

(a)
∆ = 137 kHz

2.4
1.6
0.8
0
-0.8
3.2

(b)
∆ = 103 kHz

2.4
1.6
0.8
0
-0.8
0

100 200 300 400 500 600 700 800

ν (= e qQ/h) (kHz)Q

2

Fig. 1. β-Detected quadrupole resonance spectra obtained32
Al implanted in an α-Al2 O3 stopper with its c-axis
parallel to an external field B0 . See text for more details.
|Q| moments (mb)The electric quadrupole (Q) moment for the groundstate of 32 Al(I π = 1+ , T1/2 = 33 ms) has been determined utilizing the β-NMR technique. 32 Al fragments were produced in RIPS using the fragmentationof 95 MeV/nucleon 40 Ar projectiles on a 0.37 g/cm2 thick Nb target. In order to extract spin-polarized
32
Al, the off-center emission angles θ = 1.3◦ − 5.7◦
were selected1) and the momentum was selected in the
maximum-yield region with an acceptance of 3 %. The
32
Al was implanted in a single-crystal α-Al2 O3 stopper to which a static magnetic field, B0 ∼ 0.5 T, wasapplied. To detect the quadrupole resonance, oscillating magnetic fields were supplied to 32 Al by the adiabatic fast passage (AFP) method and the resulting
β-ray asymmetry change was monitored using plastic
scintillator telescopes located around the stopper2) .
Figure 1 shows the obtained β-ray asymmetry
changes as a function of the AFP-searched regions
for the quadrupole coupling constant νQ . The sweep
widths, ∆, were taken to be 137 kHz and 103 kHz in
Figs. 1(a) and 1(b), respectively. The vertical bars
denote the statistical uncertainties. Resonance was
detected in the region of νQ ∼ 400 kHz. The solid
curves indicate the fitting functions, which were determined by the least χ2 method to reproduce the spectra(a) and (b) at the same time. The quadrupole coupling constant thus obtained was νQ = 407 ± 32 kHz.
The error had two sources, the fitting error of 22 kHz
and the error in the g-factor |g| = 1.951(5), which
was measured in this work using a single-crystal Si
stopper. The Q moment was deduced from the relation |Q(32 Al)| = |Q(27 Al) · νQ (32 Al)/νQ (27 Al)|, where
Q(27 Al) and νQ (27 Al) denote the Q moment for 27 Al
and the quadrupole coupling constant for 27 Al in αAl2 O3 , respectively. Thus, by inserting |Q(27 Al)| =140.2(10) mb3) and νQ (27 Al) = 2389(2) kHz4) , theQ moment was determined to be |Q(32 Alg.s. )| =24(2) mb. The sign of the Q moment was not determined.
In Fig. 2, the known Q moments of the Al isotopes are plotted as a function of the neutron numbers. The Q moment of 32 Al was found to be markedly
smaller than those of the other Al isotopes, but waswell reproduced by the conventional sd-shell model calculation as shown by the open squares. This result300

Al isotopes (Z=13)200

ExperimentCalc. (USD)(e p ,e n )=(1.3, 0.5)
Radial part :H.O.

100
Present work0

13 14 15 16 17 18 19 20
Neutron number

Fig. 2. Comparison of the known Q moments (solid circles)
and the USD shell model calculations (open squares).

References
1) K. Asahi et al.,: Phys. Lett. B 251, 488 (1990).
2) D. Kameda et al.,: Phys. Lett. B (2007) in press.
3) D. Sundholm et al.,: Phys. Rev. Lett. 68, 927 (1992).
4) S. J. Gravina et al.,: J. Magn. Reson. 89, 515 (1990).
5) G. Neyens et al.: Phys. Rev. Lett. 94, 022501 (2005).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Medium modification for ρ, ω mesons in 12 GeV p+A reactions†
M. Naruki, H. En’yo, R. Muto, F. Sakuma,∗2 and S. Yokkaichi for the KEK-PS E325 collaboration[meson, mass modification, chiral symmetry]
It is well established that most of hadron masses
are generated due to the spontaneous breaking of chiral symmetry, which is a crucial aspect of the strong
interaction. The modification of hadron mass and decay width in hot and/or dense matter is theoretically
predicted as a consequence of the restoration of thebroken symmetry. Experimental observations of suchphenomena have become one of the most interesting
topics in hadron physics today.
The experiment E325 has been performed at
the KEK 12-GeV Proton Synchrotron to measure
the invariant mass spectra of ρ, ω, φ → e+ e− andφ →K + K − decay modes simultaneously. Our main
goal is to detect the modification of the spectral shapeof vector mesons in nuclear media.
Figure 1 shows the invariant mass spectra of e+ e−pairs using all of the data taken in 2002. The invariant mass spectra were fitted with the combinatorial
background and known hadronic sources: ρ → e+ e− ,
ω → e+ e− , φ → e+ e− , η → e+ e− γ, and ω → e+ e− π 0 .
The combinatorial background was evaluated by theevent-mixing method. The relativistic Breit-Wigner
distributions, which were smeared by detector effects
using Geant4?) , were used to describe the spectral
shapes of resonances. The relative abundances of thesecomponents were determined by the fitting, except for
the ratio of ω → e+ e− π 0 to ω → e+ e− decay which
was fixed to their branching ratios, 59/6.95 given by
PDG. The fit results are indicated by the solid lines
shown in Fig.1. The region from 0.6 to 0.76 GeV/c2
was excluded from the fit, because the fit including thisregion resulted in failure at C.L. 99.9%.
A significant excess can be seen on the low-mass sideof the ω peak, whereas the high-mass tail of ω can be
reproduced with the expected shapes. This procedure
determines the ratio of ρ to ω, provided that ρ and ω
follow the relativistic Breit-Wigner distribution without any mass modification. After the acceptance correction, the 95% C.L. allowed parameter regions are
obtained as ρ/ω < 0.15 and ρ/ω < 0.31 for C and Cu
targets, respectively. The systematic errors arises fromthe uncertainty of the background estimation, whichamount to 0.09 and 0.21 for the C and Cu targets, respectively. The obtained ρ/ω ratios are much smaller
than unity, as was previously measured in pp interactions at the same energy?) . A possible explanation isthat most of the ρ are decaying inside the nuclei due totheir short lifetime; their mass is modified in nuclear†∗2

2

events[/ 10MeV/c ](a) C

fit result+ ω ee+ ρ e e+ φ ee+ η e eγ
+ - 0
ω e eπbackground(b) Cufit result+ ω ee+ ρ e e+ φ ee+ η e eγ
+ - 0
ω e eπbackgroundinvariant mass
Fig. 1. Invariant mass spectra of e+ e− for the (a) C and(b) Cu targets. The solid lines show the best-fit results, which is the sum of known hadronic decays,
ω → e+ e− (dashed), φ → e+ e− (thick dash-dotted),η → e+ e− γ (dash-dotted), and ω → e+ e− π 0 (dotted) together with the combinatorial background (longdashed). ρ → e+ e− is not visible (see text).

media and contribute to the excess.
The observed excess is understood by the model inwhich the mass of ρ/ω meson decreases by 9% at thenormal nuclear density. This study experimentally verified the spectral-shape modification of ρ/ω mesons in
nuclear matter.
This work was partly funded by the RIKEN Special Postdoctoral Researchers Program. We thank thestaff members of the RIKEN Super Combined Cluster
system and RIKEN-CCJ.
References
1) S. Agostinelli et al.: Nucl. Instr. and Meth. A 506, 250303 (2003).
2) V. Blobel et al.: Phys. Lett. B 48, 73 (1974).

Condensed from the article in Phys. Rev. Lett. 96, 092301(2006)
Department of Physics, Kyoto University- iv -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Ferromagnetic and charge transfer phase transitions in [FeIIFeIII(dto)3] (dto =C2O2S2) complexes examined by muon spectroscopy
N. Kojima＊1, M. Enomoto＊1, N. Kida＊1, I. Watanabe, and T. Suzuki

The
iron
mixed-valencecomplex(n-C3H7)4N[FeIIFeIII(dto)3] shows a charge transfer phasetransition (CTPT) with wide thermal hysteresis at around120 K and a ferromagnetic transition at 7 K.1, 2) 57Fe
Mössbauer spectroscopy measurement has shown that the
FeII and FeIII sites in (n-C3H7)4N[FeIIFeIII(dto)3] are clearly
distinguishable around the CTPT, which indicates that thetime scale of the valence fluctuation due to the chargetransfer between FeII and FeIII is slower than that of 57Fe
Mössbauer spectroscopy measurement ( ～ 10-7 sec).
Taking account of the wide characteristic time window (10-6
to 10-11 sec) of muon spectroscopy, we have investigated the
dynamical property of the CTPT by muon spectroscopy.
Polycrystalline samples of (n-CnH2n+1)4N[FeIIFeIII(dto)3](n = 3 and 5) were wrapped in aluminum foil and stuck to asilver plate with Scotch tape. We used a VARIOX cryostat
and a mini-cryostat with temperature ranging from 1.9 to 30
K and from 40 to 200 K, respectively. The μSR time
spectrum was measured in zero field (ZF) and longitudinal
field (LF). The LF was applied along the direction of initial
muon-spin polarization.
Figure 1 shows the ZF-μSR time spectra for n = 3. The
ZF-μSR is analyzed using

A(t) = A0exp(-λ0t)×GZ(Δ, HLF, t) + A1exp(-λ1t),slowing down due to the magnetic ordering. In the case of n
= 3, λ0 shows an anomalous enhancement with thermal
hysteresis at around 80 K. Taking account of the fact that
the CTPT is not observed in the case of n = 5,3) the
anomalous enhancement of λ0 with thermal hysteresis ataround 80 K observed for n = 3 is attributed to the
dynamically fluctuating internal field due to the CTPT. In
order to elucidate the origin of the relaxation, we measured
LF-μSR. The tails of the time spectra for both n = 3 and 5
are almost quenched by the application of a LF of 100 G.
There is substantial difference between each value of λ0 in
the vicinity of 80 K, so we can estimate the muon spin
depolarization rate corresponding to the dynamicallyfluctuating internal field at the muon sites from thedifference, i.e., λCT ≡ λ0(n = 3) - λ0(n = 5). As a result, λCT
shows a convex shape as a function of HLF in a log-log plot
and can be described by Redfield’s equation.4) Values of thecorrelation time of muon spins, τc, obtained from the fitting
are 5.7 and 10.6 μs at 80 and 110 K, respectively.
In conclusion, the CTPT and the ferromagnetic phasetransition were observed in the iron mixed-valence complex,(n-C3H7)4N[FeIIFeIII(dto)3], by means of muon spectroscopy.
The frequency of the valence fluctuation driven by theelectron transfer between FeII and FeIII sites in(n-C3H7)4N[FeIIFeIII(dto)3] is on the order of 0.1 MHz.

(1)

where A0 and A1 are the initial asymmetries of the slow andfast relaxation components, λ0 and λ1 are the respective
muon-spin relaxation rates, respectively. The GZ(Δ, HLF, t)
is the static Kubo-Toyabe function. The Δ/γμ is the
distribution width of nuclear-dipole fields at the muon sites
and γμ is the gyromagnetic ratio of the muon spin. The HLF
is LF. The first term was applied to spectra obtained above
30 K putting A1 = 0. In this case, λ0 describes effects ofdynamically fluctuating internal fields at the muon site.
Figure 2 shows the temperature dependences of λ0 for n = 3
and 5. λ0 shows the divergent peaks at 15 K and 22.5 K forn = 3 and 5, respectively, which are attributed to the critical

0.6
0.4

-1

0.2

0.3

0.3
0.2
0.2
0.1
0.1
0.0
0.0
50

100

150

200

T (K)
Fig. 2. Temperature dependences of the dynamic muon-spin
depolarization rate, λ0, for (n-C3H7)4N[FeIIFeIII(dto)3] (leftaxis) and (n-C5H11)4N[FeIIFeIII(dto)3] (right axis).

References

0.0
0

2

4

Time (μs )681) N. Kojima et al.: Solid State Commun. 120, 165 (2001).
2) M. Itoi et al.: Eur. J. Inorg. Chem. 6, 1198 (2006).
3) N. Kojima et al.: Hyperfine Interact. 156/157, 175 (2004).
4) C. P. Slichter: Principles of Magnetic Resonance (SpringerVerlag, Berlin, Heidelberg, 1978, 1990).

10

Fig. 1. ZF-μSR time spectra of (n-C3H7)4N[FeIIFeIII(dto)3].
Solid lines show the best fits of Equation (1).
＊1

0.4

0.4

-1

0.8

III

(n-CnH2n+1)4N[Fe Fe (dto)3]n = 3 heatingn = 3 cooling
n=5

Depolarization Rate (μs )Depolarization Rate (μs )

II

200 K
110 K , heating
110 K , cooling
80 K , heating
80 K , cooling
30 K
20 K
7K
1.9 K

1.0
Normalized Asymmetry

0.5

Graduate School of Arts & Sciences, The University of Tokyo

-v-

AVF

RRC

fRC

SRC

IRC

RILAC

BigRIPSRI Beam Factory

RIBF project passes a critical milestone: the successful extraction of the firstbeam from SRC
Akira Goto and the accelerator group

On December 28, 2006 at 4 pm, the first beam was
extracted from the Superconducting Ring Cyclotron (SRC)of the RI Beam Factory (RIBF). The ion type and theenergy of the beam were 27Al10+ and 345 MeV/nucleon,
respectively. This signifies that we have actually completed
the world’s first and most powerful cyclotron with K=2,500
MeV and have passed a critical milestone in the history of
cyclotrons.
Figure 1 shows the history of construction of the three
new ring cyclotrons: the fixed-frequency Ring Cyclotron(fRC), the Intermediate-stage Ring Cyclotron (IRC) and the
SRC. The sector magnets of the SRC were completed in theautumn of 2005 after a construction period of more than ten
years, and were successfully excited at the maximum fieldlevel for the first time on November 7 of that year. However,the following morning, a serious problem occurred; theliquid helium in the coil vessels and the control dewar
instantly evaporated and was released into the atmosphere.
This was because one of the feedthroughs of thesuperconducting trim coils on the liquid-helium vessel ofthe control dewar had cracked, allowing helium gas into theinsulation vacuum. This trouble resulted in the construction
falling about four months behind schedule. The field mapsof the sector magnets were measured for about two months
in April-June 2006, and the rf resonators and vacuum
chambers were then installed. Compared with the SRC, theFiscal year

1996

1997

1998

1999

2000

2001

fRC and IRC, which are room-temperature ring cyclotrons,
were constructed in a shorter period; the IRC wascompleted in September 2005 and the fRC was completed
in June 2006. Photographs of the fRC, IRC and SRC areshown in Figs. 2, 3 and 4, respectively.
At the start of the commissioning, we set the ion type forthe first beam to be uranium; the acceleration mode used isshown in Fig. 5. The commissioning of the fRC started inJuly 2006 with the acceleration of a uranium beam. The
238 73+
U ion beam passed through the electrostatic deflectorof the fRC for the first time on July 21. From September toNovember, acceleration tests of the fRC using a uranium
beam continued to be performed, in between which
experiments using the existing facility were conducted. The
commissioning of the IRC started after the rooms for the
IRC and SRC were designated to be a radiation-controlledarea on November 22. For the tuning of the IRC, it was
decided that a krypton beam would be used, taking the low
intensity of the uranium beam into account. The 84Kr31+ ion
beam, the charge-to-mass ratio of which is close to that of
238 88+U , was accelerated and extracted from the IRC for the
first time on November 25; it took as little as about 2 hours
for the tuning from the injection and extraction. The
acceleration of the krypton beam was performed bybypassing the fRC. For the commissioning of the SRC, thebeam was switched to an aluminum beam (27Al10+) on

2002

2003

2004

2005

2006

2007

Accelerator building
completed

Building

Experimental building
completed

Installation and assembling (RF, vacuum)
Installation and assembling
Model sector magnets(sector magnets)

Design and fabrication (whole SRC)

completedAug. 25, 2005

Cooldown and excitation

First beam (Al)Dec. 28, 2006
Re-cooldown and magnetic
field measurement

SRC
Excited at the maximum field level
Nov. 7, 2005
Vacuum leak in the control dewar
Nov. 8, 2005

IRC

Design and fabrication

Installation and assembling

Design and fabrication

fRC

First beam (Kr)Nov. 25, 2006

Installation and assembling
First beam (U)July 21, 2006

Fig. 1. History of construction of the three new ring cyclotrons: fRC, IRC and SRC.

December 13, which also has a charge-to-mass ratio close
to that of the uranium beam and was expected to havehigher intensity than the krypton beam. The acceleration of
the aluminum beam was also performed by bypassing thefRC; the acceleration mode used is shown in Fig. 6. The
beam injection into the SRC became possible on December
21 when the conditioning of two of the four rf resonators
was complete. At this time, during the acceleration, an
unexpected phenomenon occurred; a beam suddenly
stopped at a position about 1,000 mm from the injection
radius and did not proceed further. It was found that thiswas due to a quadrupole mass analyzer that had been placedby mistake at that position, obstructing the beam passage.
On December 28 at 6 am, after its removal, the evacuationof the vacuum chamber and the necessary reconditioning of
the rf resonators, the beam injection and acceleration wererestarted. This time, the beam was accelerated up to theoutermost radius immediately, but it took more time than
expected for the extraction. However, by tuning themachine carefully, for instance using a radiation survey
monitor temporarily set at the exit of the SRC, the extracted
beam was finally detected at 4 pm using a beam profile
monitor and a Faraday cup placed 5 m downstream of the
SRC. The data obtained using these monitors are shown in
Figs. 7 and 8, respectively. Some photographs of the scenes
in the control room at the time the first beam was detected
are shown in Figs. 9-14. A press conference was held from
8 pm in the 2F conference hall of the RIBF building.
We achieved our goal by the end of 2006 as scheduled.
We plan to extract the first beam of uranium ions from the
SRC by the end of March 2007.

Fig. 2. Photograph of the fRC.

Fig. 3. Photograph of the IRC.

Fig. 4. Photograph of the SRC. People gathered on the top of the SRC just before themagnetic field measurement started in April 2006.

stripper2
stripper3

stripper1

ECRIS

RILAC

RRC

238

238

238

14+

U

U

14+

0.67

35+

U

11

fRC
238

U

73+

50

BigRIPS

IRC

SRC

238

238

U

88+

114

U

88+

345 MeV/nucleon

Fig. 5. Acceleration mode of the uranium beam planned in the initial commissioning. Note that we have decided from theacceleration tests performed so far that the uranium beam will be accelerated with 71+ ions instead of 73+ ions in thefRC, 86+ ions instead of 88+ ions in the IRC and SRC, and that 35+ ions instead of 14+ ions will be provided from the
ECRIS.

stripper

ECRIS
27

Al

6+

BigRIPS

RILAC

RRC

IRC

SRC

27

27

27

27

Al

10+

2.7

Al

10+

45

Al

10+

114

Al

10+

345 MeV/nucleon

Fig. 6. Acceleration mode of the first aluminum beam used. The fRC is bypassed in this mode.

beam off

beam onFig. 8. Trend graph of beam current of the first beam.
Fig. 7. Profile of the first beam.

Fig. 9. Photograph of the staff members operating theaccelerators in the control room.

Fig. 12. Same as Fig. 9.

Fig. 10. Same as Fig. 9.

Fig. 13. Photograph of people cheering upon thedetection of the first beam.

Fig. 11. Same as Fig. 9.

Fig. 14. Same as Fig. 13.

㻃㻃

Status of BigR IPS se parator pro ject
T. Kubo, K. Kusaka, K. Yoshida, A. Yoshida, T. Ohnishi, N. Fukuda, M. Ohtake, Y. Yanagisawa, T. Haseyama, H. Sakurai,
T. Motobayashi, and Y. Yano
The BigRIPS separator1,2) and its RI-beam delivery line3)
are being constructed as a major experimental installation in
the RI beam factory (RIBF). The construction is currently inthe final stage of the 5-year construction period, whichbegan in the fiscal year 2002.
Figure 1 shows a schematic layout of the BigRIPS
separator and RI-beam delivery line along with RIBF
cyclotrons. The BigRIPS separator is a superconducting
in-flight separator, which is characterized by large
acceptances and a two-stage separator scheme. The large
acceptances were achieved by using large-aperture
superconducting quadrupoles, enabling the efficient
production of RI beams using the in-flight fission of
uranium beams as well as the projectile fragmentation. The
two-stage separator scheme makes it possible to deliver
tagged RI beams as well as to realize two-stage isotopic
separation. In the RI-beam tagging mode, the first stage of
the BigRIPS separator serves to produce and separate RI
beams, while the second stage is employed to identify
RI-beam species in an event-by-event mode.
The
BigRIPS separator leads into the RI-beam delivery line,
which was designed to serve as a zero-degree forward
spectrometer, called ZeroDegree, as well as to transport RI
beams to experimental setups placed downstream. When
it is employed as a spectrometer, Zerodegree analyzes andidentifies projectile reaction residues in secondary-reaction
studies of the RI beams.

Fig. 1. Schematic layout of RI beam factory in 2007.
The BigRIPS magnets consist of fourteen superconducting triplet quadrupoles (STQs) and six roomtemperature dipoles. Their installation in the beam line wascompleted in April 2006, and all the magnets have beensuccessfully tested online. Coil quenching did not occur
up to maximum operational currents for most of the STQs,
even though they were once warmed up before theinstallation. Figure 2 shows photographs of the BigRIPS
separator.
b)

a)
c)

Fig. 2. Photographs of BigRIPS separator: a) the left
photograph shows the first stage of the BigRIPS separator,and b and c) the right photographs show the second stage.
The five STQs on the BigRIPS first stage are cooled by alarge liquid helium cryogenic plant using a 50-m-longtransfer line. A cooling test was carried out several times tocheck the design and performance of the cryogenic plant,
and the 4-K cooling capacity and total 4-K heat load were
measured to be about 510 and 190 W, respectively. The
excess cooling capacity of the plant amounts to about 320
W, which will be employed to cope with the head loads
caused by the neutron radiation from the production target
and beam dump (neutron heating). The gas-cooled current
leads for the first-stage STQs have also been tested toensure that they are cooled properly with design values ofhelium-gas flow rate. It took the plant about three weeks
to cool the five STQs with a total cold-mass weight of about
42 tons down to the temperature of liquid helium (16 days)
and then to fill the cryostats with liquid helium. Continuous
operation of the cryogenic plant started in October 2006.
When a high level of neutron heating exists, thecryogenic plant has to supply much more liquid helium to
the STQs by exploiting the excess cooling capacity. The
heat load due to neutron heating often changes during theoperation, causing instability of the liquid-helium level ofthe cryostat. We employ a heater installed in the helium
vessel of the cryostat in order to compensate the change ofneutron heating. This operation mode of the plant hasbeen tested, in which neutron heating was simulated using
another heater. We were able to control the liquid-helium
level, although further testing is needed to make theliquid-helium level more stable. By using the PHITS
simulation code, the heat load due to neutron heating has
been estimated to be about 200 W (mainly to the first STQ
right after the production target) for the most serious case:uranium beams at 350 MeV/nucleon and 1 pµA. This iswell within the measured excess cooling capacity of thecryogenic plant.
The rest of STQs on the BigRIPS second stage are cooled
by a small stand-alone refrigeration system, which ismounted on the cryostat of each STQ and consists of a GM
cryocooler and a GM/JT cryocooler. The GM crycooler hasa cooling capacity of 100 W at 80 K, being employed tocool high-Tc current leads as well as 80-K thermal shields.
The GM/JT cryocooler is used to recondense evaporating
helium gas in the helium vessel of the STQs. The cooling
capacity of the GM/JT cryocooler is as low as about 2.5 W
at 4.3 K. Because the cryoccoler can only reliquefy
evaporating helium, it is necessary to precool the cold massusing liquid nitrogen as well as liquid helium, in order tomake the GM/JT cryocooler operational. About two weeks
are needed to precool each STQ, which was carried out
again at RIKEN since they were warmed up in a factory
before shipping. All of the second-stage STQs have been
kept at the temperature of liquid helium for more than one
year by continuously operating the cryocoolers.
Field-map measurements have been carried out for someof the STQs and dipoles. The measured data are currently
being analyzed. They will be employed for a ray-tracing
calculation of the BigRIPS ion optics.
b)
a)

c)

Fig. 3. a) Photograph of the focal-plane chamber at the final
focus of BigRIPS separator, and b and c) photographs ofhigh-power beam dump: beam-dump chamber to beinstalled at first dipole of BigRIPS separator (upper) andinside view of beam dump (lower).
Focal-plane chambers have been installed at the eight
focuses of the BigRIPS beam line along with their vacuum
pump system. The focal-plane chambers are equipped withfocal-plane devices, such as the slit system, the energy-

degrader system, the foil/target ladder system, and thedetector stand system. They are employed for isotopic
separation, RI-beam tagging and beam diagnoses, in
combination with beam-line detectors mounted on thedetector stands. Figure 3-a shows a photograph of one of
the focal-plane chambers. The control systems for the
focal-plane devices and the vacuum pump system have beensuccessfully tested online.
Beam-line detectors, such as a delay-line parallel-plateavalanche counter (DL-PPAC) for position measurement
and a multisampling ion chamber (MUSIC) for energy-loss
measurement, have been fabricated and are presently being
tested online. The data acquisition system for the beam-line
detectors is also being assembled along with thearrangement of a data-acquisition room.
A high-power production target and a high-power beam
dump have been fabricated and installed in the beam line.
They have been designed to cope with beam powers as highas 83 kW, which corresponds to the case of a 238U beam at
350 MeV/nucleon and 1 pµA. The production target is awater-cooled rotating-disk target system, and the beam
dump is a water-cooled system for which a Cu screw tube
and a Cu swirl tube are employed. Figures 3-b and 3-cshow some photographs of the high-power beam dump.
a)b)Fig. 4. a) Photograph of radiation shields being installed,
and b) photograph of RI-beam delivery line being
assembled.
The radiation shields for the BigRIPS first stage, which
consist of approximately 200 concrete blocks and ironblocks and weigh approximately 4000 t in total, have been
fabricated, and are currently being installed. Figure 4-ashows a photograph of the radiation shields after the firstlayer had been installed.
The RI-beam delivery line consists of ten STQs and two
dipoles that have the same designs as the second-stage
magnets of the BigRIPS separator. The fabrication andinstallation of these magnets along with the focal-planechambers are almost complete. Figure 4-b shows aphotograph of the delivery line.
The commissioning of the BigRIPS separator and thedelivery line is scheduled in 2007.
References
1) T. Kubo: Nucl. Instr. and Meth., B 204, 97 (2003).
2) T. Kubo et al.: IEEE Trans. Appl., Supercond., in press.
3) Y. Mizoi et al.: RIKEN Accel. Prog. Rep., 38, 297 (2005).

RIKEN Accel. Prog. Rep. 40 (2007)

PrefaceOn April 1, 2006, the RIKEN Nishina Center (RNC) for
Accelerator Based Science was inaugurated as a completely
new research center, integrating RIKEN’s existing accelerator
related laboratory and groups including RIKEN Brookhaven
National Laboratory (BNL) Research Center (RBRC) in the
USA and RIKEN Rutherford- Appleton Laboratory (RAL)
Facility Office in the UK Presently, the RNC is organized
into the following five divisions, one group and two affiliatedresearch centers abroad: the Accelerator Division (comprising
Accelerator Development Group and Accelerator Operation
Group), Nuclear Physics Research Division (Heavy Ion
Nuclear Physics Laboratory, Applied Nuclear Physics
Laboratory , Radioactive Isotope Physics
Laboratory,
Superheavy Element Laboratory, Experimental Installations
Development Group and Experimental Installations Operation
Group), User Liaison and Support Division (User Liaison andSupport Group), Sub Nuclear System Research Division(Radiation Laboratory , Advanced Meson Science Laboratory
and Theoretical Physics Laboratory), Accelerator Applications
Research Division (Accelerator Applications Research Group),
Safety Management Group, RBRC (Theory Group andExperimental Group) and RAL Facility Office. The RNC
oversees the extensive utilization of the RI Beam Factory(RIBF) and RAL muon facility by users worldwide, andpromotes theoretical and experimental research in particle andnuclear physics. The promotion of accelerator applications
research is another important mission.

system and their experimental installations in the Wako-city
campus as RI Beam Factory or simply RIBF.
The existing facility commenced the regular operation forusers in 1990. A K540-MeV ring cyclotron (RRC) properly
uses a couple of pre-accelerators: a 16-MV variable-frequency
linac (RILAC) following an 8-MV fixed-frequency booster
linac (CSM), and a K70-MeV AVF cyclotron (AVF). The
RILAC has an injector of a variable-frequency RFQ linac(FCRFQ) equipped with two 18 GHz ECR ion sources ofnormal conducting and superconducting (SCECR) types. The
AVF is equipped with two ECR ion sources of 10 GHz and14.5 GHz (installed by the University of Tokyo), and apolarized deuteron source of an atomic-beam type (DPOL).
Various experimental apparatus are installed not only for theapplication to nuclear physics, but also to nuclear chemistry,
bio and medical science, and materials science. Among them, aprojectile-fragment separator (RIPS) is well known to produce
very intense light-atomic-mass (less than nearly 60) RI beams.
The RIBF adds new dimensions to the existing facility’s
capabilities: a new high-power heavy-ion booster system
consisting of three ring cyclotrons with K-values of 570 MeV(fixed frequency, fRC), 980 MeV (Intermediate stage, IRC)
and 2500 MeV (superconducting, SRC), respectively, boosts
energies of the output beams from the RRC up to 440
MeV/nucleon for light ions and 350 MeV/nucleon for very
heavy ions. An 880 MeV polarized deuteron beam is alsoavailable. These primary heavy-ion beams is converted into
intense RI beams via the projectile fragmentation of stable
isotopes or the in-flight fission of uranium isotopes by asuperconducting fragment separator, BigRIPS. The
primary-beam intensity is targeted to be 1 particle micro
ampere. The combination of the SRC and the BigRIPS will
greatly expand our knowledge of nuclear world into presently
inaccessible region on the nuclear chart.

Nishina center is RIKEN’s first research center named after
our pioneering scientist, Dr. Yoshio Nishina. He was amulti-faced scientist who exhibited expertise in the following
fields: theoretical physics, experimental particle, nuclear andcosmic-ray physics, accelerator building, and accelerator
applications such as radiation biology and nuclear chemistry.
Nowadays it is quite rare to find out such multi-faced scientist.
Thus, Nishina center, as a collective of experts, covers eachand all of these fields.

RI beam transport lines downstream of the BigRIPS
composing a zero-degree forward spectrometer (ZDS) which
is one of major experimental installations is being assembled.
Its regular operation for the users will commence in October,2007.

In the context of the organizational change, starting thisvolume No. 40, RIKEN Accelerator Progress Report will beedited to report yearly progress of researches and projects
conducted by RNC’s laboratories and groups and by users of
the RIBF and the RAL muon facility. It also records annually
the RNC’s administrative activities such as Scientific Policy
Committee meetings and Program Advisory Committee
meetings etc. as well as domestic and international
collaborations and workshops.

Major other experimental installations planned to beconstructed are: a large acceptance superconducting
spectrometer (SAMURAI), a facility utilizing very slow RI
beams (SLOWRI), a low-to-medium energy polarized RI
beam facility at the RIPS (RI Spin Lab), a high-resolution RI
beam spectrometer (SHARAQ) constructed by the Universityof Tokyo, a rare RI precision mass measurement apparatus(Rare RI mass ring), and an electron-RI scatteringexperimental apparatus (e-RI ring). A new additional injector

Until now, we have called the existing accelerator facility as
RIKEN Accelerator Research Facility (RARF), but hereafter
we will address the existing and new heavy-ion accelerator-1-

RIKEN Accel. Prog. Rep. 40 (2007)

linac (New injector) to the RRC is also planned. An extensive
R&D of each installation is under way as well.

experiment which started in 1993, and the results experimentally
verified in-medium vector meson mass modification as predicted
as a signature of partially restored chiral symmetry in dense
matter. The results were released to the press and the paper was
highlighted in Physical Review Focus. In addition study of matrix
models as the non-perturbative formulation of string theory is
being pursued. In particular, a novel technique was introduced,
by which one can incorporate space-time curvature into matrix
models. A novel lattice Dirac operator of overlap type has been
constructed which describes the propagation of a Dirac fermion
in an external gravitational field. A new value for the finestructure constant was set with an uncertainty of 0.7 parts per
billion. It was done by the high precision calculation of QED,
together with the new high precision measurement of theelectron's magnetic moment performed at Harvard University.
The result was published in Physical Review Letters. Along withthe other paper reporting the measurement, this development ispraised as the physics story of the year 2006 by Physics News
Update.

I would like to summarize highlights of this year 2006 as
follows:
Most remarkable achievement of accelerator researchdivision is that they succeeded in the first beam extraction fromthe superconducting ring cyclotron, at 4 pm on December 28 in
2006, which was one hour and 20 minutes before the official
end of RIKEN’s working day in 2006. It was really amazing,
because we had been declaring for many years to theinternational community that our first beam would be extracted
in 2006, and actually we did it. The beam was aluminum
27 10+
Al with 345 MeV per nucleon. This means that the world’s
first ring cyclotron with superconducting sector magnets with
K2500 MeV, strongest bending power ever in the cyclotron
history, was born. On December 29, major Japanesenewspapers and TV reported this event. Science magazine
reported the completion of the new facility with the article
entitled “Japan gets head start in race to build exotic isotope
accelerators”, while Nature magazine featured the article“Japan speeds up nuclear physics”.
In nuclear physics research division, a problem withcorrelation of two halo-neutrons in 11Li, which was unsolved
for a few decades, has been experimentally resolved via a
newly developed Coulomb break-up setup realized at RIPS. In
this experiment, two-neutron detection efficiency at low
excitation energy of 11Li has been highly improved to observe
low-lying E1 strength. The paper of this work was highlighted
in Physical Review Focus. The other achievement was to
examine the Einstein-Podolsky-Rosen paradox, theobservation problem in quantum mechanics. In this work, anuclear reaction of (d,2He) was employed to realize a purequantum state, and spin-correlation of two protons wasmeasured at SMART. This result is in agreement with
non-local quantum mechanical prediction. Concerning
in-beam gamma-ray spectroscopy on light and neutron-richnuclei at RIPS, a new method, "multi-channel direct reaction
method", was developed to measure a proton-shell gap in theneutron-rich nucleus 23F. Electric quadrupole moments of 31,
32
Al, neutron-rich isotopes located on the borderline of theisland of inversion, have been measured by taking advantageof spin-polarized radioactive beams. New program has beenlaunched this year to develop low-energy spin-polarizedradioactive beams using inversed-kinematics reactions, and abeam of polarized 17N has been successfully produced.
In-beam Moessbauer studies with radioactive beams havepresented evidence for the synthesis of novel chemical speciesof Fe, (O2)-Fe-(O2), via a reaction between a solid oxygen andenergetic 57Mn nuclei.

In accelerator applications research division, irradiation ofheavy-ion beam has become a new method for mutation breedingof ornamental plants to produce new cultivars valuable in themarket. The phenotypes related with sterility, variegation, andfloral color were evaluated in the screening for new cultivars ofgarden flowers. This year, new mutants of the wheat, rice,
Chrysanthemum, Dianthus, begonia, Tricyrtis and a red algawere established. The gas-jet transport system coupled with thegas-filled recoil ion separator GARIS was developed to startsuperheavy element chemistry in RIKEN in collaboration with
Superheavy Element Laboratory. The performance of the system
was appraised using 206Fr and 245Fm produced in the169
208
Tm(40Ar,3n)206Fr
andPb(40Ar,3n)245Fm
reactions,206
245
respectively. The Fr and Fm separated with GARIS weretransported to a rotating wheel system for a spectrometry under
extremely low background condition. The gas-jet efficiency wasalmost 100% for the beam intensity up to 2 particle micro
amperes.
As for safety management group, they applied for thepermission of the IRC and the SRC operation to the Ministry of
Education, Culture, Sports, Science and Technology in April, andobtained the authorization in May. Since the acceleration of theuranium beam has begun, they have been acquiring more
knowledge on the safe handling of uranium. The construction ofa new radiation interlock system, HIS was finished in November.

In sub nuclear system research division, the paper entitled"Evidence for in Medium Modification of the Phi Meson at
Normal Nuclear Density" was published in Physical Review
Letters. This paper describes the final goal of KEK-PS E325

-2-With regard to RBRC, due to the budgetary constraint ofUSA, there was concern that they may have to cancel the beamtime. However the problem was cleared by a large sum of
personal donation. Amongst many publications this year,
followings are worth noting: 1) heavy quark production crosssection and its flow in Au+Au collisions, 2) direct photon
production in p+p and 3) J/psi production in Au+Au and p+p.
They are essential measurements both in the proton
spin-structure studies and in the QGP studies.

RIKEN Accel. Prog. Rep. 40 (2007)

In RAL mon facility, the most intense pulsed muon beam in
the world is produced, and a variety of muon experiments havebeen performed by applying unique characters of muon. Using
positive muons, basic properties of various condensed matters,such as high temperature superconductors, quantum spin
systems, molecular conductors and chemical complexes, were
investigated by employing Muon Spin Relaxation (mSR)
methods. One of interesting results is that muon detected theelectron dynamics around charge-transfer phase transition
associated with spin-state change in the iron mixed-valencecomplexes. In order to apply the mSR method tosurface/interface science, an ultra low-energy muon beam has
been developed, and the first application experiment with athin foil of high temperature superconductor was performed.
Negative muons generate spontaneously chain-reacting d-t
fusions in D2 + T2 systems (muon catalyzed fusion).
Experiments using ortho and para deuterium were conductedto observe a difference in the muon catalyzed fusion processes.
By observing muonic X-rays produced in muonic atom
formations of nuclei implanted in solid hydrogen, afundamental experiment on nuclear charge density distribution
was carried out to measure an isotope shift of muonic X-ray
energies between 88Sr and 86Sr.

crops.
On October 3, the Japanese Emperor and Empress visited
RIKEN and toured RIKEN’s No.9 cyclotron, SRC. The
Emperor first toured RIKEN’s No.5 cyclotron, RRC on March
12, 1992. In 2007, RIKEN will commemorate the 70th year
since Dr. Nishina’s cyclotron, RIKEN’s No.1 cyclotron, began
operation in1937.
Yasushige Yano
Director,
RIKEN Nishina Center for Accelerator-Based Science

The Memorandum of Understanding on the Creation of theCouncil for China-Japan Research Collaboration on Nuclear
Physics was signed by W. Shen, director of the Chinese Nuclear
Physics Society and Y. Yano, director of the RNC on November
10 in Beijing. The council is created to promote and advance thecollaborative activities between the Japanese and Chineseorganizations in nuclear physics and related fields.
The Japan-US Theory Institute for Physics with Exotic
Nuclei (JUSTIPEN) was established in July. The “institue” islocated in the RNC Wako-city site, and collaborative activities
are made in the area of low-energy nuclear structure, reactions,and nuclear astrophysics. JUSTIPEN is based on a programsupported by the US Department of Energy, and operated
jointly by the University of Tokyo and RIKEN under thecomprehensive agreement among them.
(The actual
operatives are the Center for Nuclear Study (CNS), theUniversity of Tokyo and the RNC.)
The Todai-RIKEN Joint International Program for Nuclear
Physics research was established on June 30. The program is
aimed at enhancing collaboration between the University ofTokyo and RNC on experimental studies, with equipments
built by University of Tokyo in the RIBF and related
theoretical studies on the international basis.
Supplementary Agreement for Implementation of Joint
Research between RIKEN and National Innovation Center for
Plant Biotechnology, South Africa was signed by S. G.
Mundree, Chief Executive Officer of PlantBio Trust and Y.
Yano, director of the RNC on June 21, at RIKEN. This isresearch cooperation for ion-beam mutagenesis on African-3-

RIKEN Accel. Prog. Rep. 40 (2007)
RIKEN Accel. Prog. Rep. 40 (2007)

Differential cross sections of the proton inelastic scattering on 32 Mg
S. Takeuchi, N. Aoi, H. Baba,∗1 T. Fukui,∗2 Y. Hashimoto,∗3 K. Ieki,∗4 N. Imai,∗5 H. Iwasaki,∗6 S. Kanno,∗4
Y. Kondo,∗3 T. Kubo, K. Kurita,∗4 T. Minemura,∗5 T. Motobayashi, T. Nakabayashi,∗3 T. Nakamura,∗3
T. Okumura,∗3 T. K. Onishi,∗6 S. Ota,∗2 H. Sakurai,∗6 S. Shimoura,∗1 R. Sugou,∗4 D. Suzuki,∗6 H. Suzuki,∗6
M. K. Suzuki,∗6 E. Takeshita,∗4 M. Tamaki,∗1 K. Tanaka, Y. Togano,∗4 and K. Yamada[nuclear structure, in-beam γ-ray spectroscopy]
Large collectivity in 32 Mg has been found from alarge B(E2) for the 2+ state.1) For further understanding of the structure of 32 Mg, the location of the first
4+ state is crucial. The 2321-keV state is suggested
to have a spin and parity (J π ) of 3− or 4+ ,1,2) but nodecisive evidence has been given. In the present experiment, proton inelastic scattering was applied to 32 Mg
in inverse kinematics and the J π of the 2321-keV state
was studied by angular distribution of its differential
cross sections.3)
Figure 1 shows the Doppler-corrected γ-ray spectrum associated with the 32 Mg(p, p0 ) reaction. The
two peaks at 885 keV and 1436 keV are clearly seencorresponding to the transitions from the 885-keV (2+ )state to the ground state and that from the 2321-keV
state to the 885-keV state. Differential cross sections
were obtained from the measured γ-ray yields in the
0.2◦ step for the laboratory scattering angle of 32 Mg.
Figure 2 shows the angular distributions for excitation to the 885-keV and 2321-keV states. The experimental data are compared with distorted-wave calculations assuming the possible angular momentum transfers ∆L of 3 and 4. The calculations were performed
with CH89 optical potential parameters4) using thecoupled channel calculation code ECIS97.5) For ∆L= 4, where the J π of the 2321-keV state is assumed to
be 4+ , the excitations to these two states were calculated by assuming a symmetric rotational model (solid
curves). Multistep excitation processes are included in
the calculation. For ∆L = 3 or J π = 3− for the 2321keV state, the excitations to the 885-keV and 2321-keV
states were calculated respectively using the symmetric rotational model and harmonic vibrational model(dashed curves). The angular distribution for the transition to the 2+ state was well reproduced by the calculation for both cases. Comparisons between the data
and the calculated distributions for the 2321-keV state
indicate that the ∆L = 4 transition is favored over the∆L = 3 transition.

Fig. 1. Doppler-corrected γ-ray spectrum measured by32
Mg(p, p0 ) reaction.

Fig. 2. Angular distributions of scattered 32 Mg particle
for γ rays from the 885-keV(filled circles) and 2321keV(open circles) states. Solid curves show the calculated distributions for the ∆L = 2 and 4 transitions.
Dashed curves show the calculated distributions for the∆L = 2 and ∆L = 3.

References
∗1
∗2
∗3
∗4
∗5
∗6

Center for Nuclear Study, University of Tokyo
Department of Physics, Kyoto University
Department of Physics, Tokyo Institute of Technology
Department of Physics, Rikkyo University
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
Department of Physics, University of Tokyo-5-1) J. A. Church et al.: Phys. Rev. C 72 054320 (2005) andreferences therein.
2) W. Mittig et al.: Eur. Phys. J. A 15, 157 (2002).
3) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 39, 63(2006).
4) R. L. Varner et al.: Phys. Rep. 201 57 (1991).
5) J. Raynal: unpublished coupled-channel code ECIS97.

1

RIKEN Accel. Prog. Rep. 40 (2007)

Lifetime measurement of the ﬁrst 2+ state of 32 Mg
M. K. Suzuki,∗1 H. Iwasaki,∗1 H. Sakurai, A. Dewald,∗2 T. Fukuchi,∗3 T. Fukui,∗4 Y. Ichikawa,∗1 E. Ideguchi,∗5
M. Liu,∗5 T. Nakao,∗1 M. Niikura,∗5 H. J. Ong,∗1 T. K. Onishi,∗1 H. Otsu, T. Sumikama, D. Suzuki,∗1
H. Suzuki,∗1 Y. Zheng,∗5 and S. Shimoura,∗5[]
Nuclear reactions: 197 Au(32 Mg,32 Mg∗ )197 Au E=26MeV/u; RDM
We applied the recoil distance method (RDM) at anintermediate energy to measure the mean lifetime of32
32
Mg is a typical nucleus of the ‘island of inMg(2+1 ).
+version’ where the experimental B(E2;2+
1 → 0 ) value
implies the break of closed-shell structures. Unfortunately the measured B(E2) values of 454±78[e2 fm4 ]1) ,333±70[e2 fm4 ]2) , and 622±90[e2 fm4 ]3) by the interme2
4 4)diate Coulomb scattering, 325+109
by the β-γ−65 [e fm ]fast-electronic-timing technique reported so far are notconsistent and have large experimental errors. Thus,
high-precision measurement of B(E2) with an accuracyof 10% is desirable.
The RDM is an alternative technique to the ones+
used so far to extract the B(E2;2+
1 → 0 ) value in32
Mg. Here, RI beams, excited by a reaction at the secondary target, ﬂy to a degrader foil, which is mounted
at a deﬁnite separation (∼ 1 mm) downstream of thetarget. γ rays emitted before and after the degrader
foil show diﬀerent Doppler shifts according to the different ion velocities. As a consequence, in the γ ray
spectra, two components of a γ transition are observed,
from which the lifetime of the level can be determined.
The experiment was performed in the RIKEN accelerator facility. A radioactive beam of 32 Mg was
produced via the fragmentation of a 95 MeV/nucleon
40
Ar beam using a 277-mg/cm2 -thick 9 Be target. The
secondary beam was separated using the RIPS5) by
the Bρ-∆E-Bρ method. Particle identiﬁcation of thesecondary beams was carried out using the energy deposited in a 0.1-mm thick Si detector placed in F2 andthe TOF between a 0.1-mm-thick plastic scintillator
placed in F2 and PPACs placed 5.3 m apart along thebeam line. The 32 Mg beam had an intensity of 103
ions per second and a purity of about 21%. A reaction target system composed of a secondary targetand degrader foil was placed at the ﬁnal focal planeof RIPS. Two diﬀerent systems were used, one witha 1353-mg/cm2 -thick Au target and the other witha 189.9-mg/cm2 -thick Au degrader separated by 1200
µm (target system 1) and a 1339-mg/cm2 -thick Au target with a 190.7-mg/cm2 -thick Au degrader separated
by 5000 µm (target system 2). The mean energies of32
Mg nuclei between the target and the degrader were
∗1
∗2
∗3
∗4
∗5

calculated to be 26 MeV/nucleon for both systems.
Scattered particles were detected using two PPACs
located 200 mm and 383 mm downstream from thetarget to measure the emission angle of the scatteredparticles. Moreover, the scattered particles were identiﬁed using a telescope comprised of three layers of Si
detectors with thicknesses of 200 µm, 500 µm, and 500µm. The telescope was located 458 mm downstream
from the target and covered an area of 150 × 150 mm2 ,corresponding to laboratory scattering angles of up to
12 degrees.
γ rays were detected using the position-sensitive Ge
detector array GRAPE6,7) , which is composed of 12 Ge
crystals surrounding the target at an angle of 120 degrees with respect to the beam axis. Each crystal wasplaced at a distance of 135 mm from the target. To decrease the γ background, an active shield was installed
upstream and downstream of the GRAPE consisting ofseven BGO crystals with a size of 80 × 250 × 25 mm3 .
As shown in Fig. 1, we obtained γ-spectra using
both target system 1 and 2, which were Doppler corrected to take account of the ion velocity between thetarget and the degrader under the condition of no BGO
signals. As expected, the system 2 spectrum has asingle-peak structure. On the basis of analysis of thesystem 2 spectrum, a double-peak structure is observedin the system 1 spectrum.

Fig. 1. Doppler-corrected γ-ray energy spectra using thetarget system 1 and the target system 2.

References
1) T. Motobayashi et al.; Phys. Lett. B 346 (1995) 9.
2) B. V. Pritychenko et al.; Phys. Lett. B 461 (1999) 322.
3) V. Chisté et al.; Phys. Lett. B 514 (2001) 233.
4) H. Mach et al.; J. Phys. G: Nucl. Part. Phys. 31 (2005)
1421.
5) T. Kubo et al.; Nucl. Instrum. Methods B 70 (1992)
309.
6) S. Shimoura; Nucl. Instrum. Methods A 470 (2004) 188.
7) M. Kurokawa et al.; IEEE Trans. Nucl. Sci. 50 (2003)
1309.

Department of Physics, University of Tokyo
Institut für Kernphysik Universität zu Köln
Department of Physics, Osaka University
Department of Physics, Kyoto University
Center for Nuclear Study, Graduate School of Science, University of Tokyo-6-

1

RIKEN Accel. Prog. Rep. 40 (2007)
RIKEN Accel. Prog. Rep. 39 (2006)

Proton inelastic scattering studies at the borders of the “island of
inversion”: The 30,31 Na and 33,34 Mg case
Z. Elekes,∗1 Zs. Dombrádi,∗1 A. Saito,∗2 N. Aoi, H. Baba,∗2 K. Demichi,∗2 Zs. Fülöp,∗1 J. Gibelin,∗3 T. Gomi,∗2
H. Hasegawa,∗2 N. Imai,∗4 M. Ishihara, H. Iwasaki,∗4 S. Kanno,∗2 S. Kawai,∗2 T. Kishida, T. Kubo, K.
Kurita,∗2 Y. Matsuyama,∗2 S. Michimasa,∗4 T. Minemura, T. Motobayashi, M. Notani,∗4 T. Ohnishi,∗4 H.J.
Ong,∗4 S. Ota,∗5 A. Ozawa,∗6 H.K. Sakai,∗2 H. Sakurai, S. Shimoura,∗4 E. Takeshita,∗2 S. Takeuchi, M.
Tamaki,∗4 Y. Togano,∗2 K. Yamada,∗2 Y. Yanagisawa and K. Yoneda[NUCLEAR STRUCTURE, Unstable nuclei, gamma-ray spectroscopy]
A 40 Ar primary beam of 94 MeV/nucleon energy
with 60 pnA intensity was transported to a 181 Ta production target of 0.5 mm thickness. The RIPS fragment separator analyzed the momentum and mass of
the reaction products. The 30,31 Na and 33,34 Mg beams
were produced in two individual runs at diﬀerent Bρ
values. An aluminum wedged degrader of 221 mg/cm2
was placed at the momentum dispersive focal plane(F1) to purify the constituents. In the ﬁrst run of
30,31
Na, the secondary beam included neutron–rich O,
F, Ne and Na nuclei with A/Z ≈ 3 whereas mainly
Mg and Al isotopes were mixed in the second run of33,34
Mg. The fragment separator was set to its full 6%
momentum acceptance to achieve as high beam intensities as possible. The total intensity was about 100 particle/s (pps) for both runs, while the 30,31 Na/33,34 Mg
intensities reached 8, 6, 3 and 2 pps, respectively, on
average. The incident beam species was identiﬁed onan event–by–event basis from energy loss, time–of–
ﬂight (TOF), and magnetic rigidity (Bρ).
The secondary beam hit a liquid hydrogen 30–mm–
diameter target the thickness of which was 24 mm andits entrance and exit windows were made of 6.6 µm
Aramid foil. The average areal density of hydrogencooled to lower than 20 K was 210 mg/cm2 . The meanenergy of the isotopes in the target was approximately
50 MeV/nucleon. Two PPACs at F3 upstream of
the target monitored the position of incident particles.

The reaction products and scattered particles were detected and identiﬁed by a PPAC and a silicon telescopeof three layers with thicknesses of 0.5, 0.5, and 1 mm
located about 80 cm downstream of the target. Z was
identiﬁed by the TOF–energy loss method in which
TOF was measured between the PPACs upstream anddownstream of the secondary target. The isotopes was
separated by the ∆E–E method. The de–exciting γ
rays emitted by the inelastically scattered nuclei weredetected by the DALI2 setup consisting of 146 NaI(Tl)scintillators surrounding the target. To determine thecross sections of the produced γ rays in proton inelastic
scattering, the peak positions determined were fed into
the detector simulation software GEANT4 and the resultant response curves plus smooth polynomial backgrounds were used to analyze the obtained experimental spectra. From a distorted wave analysis of the crosssections, we derived the “matter” deformation parameter (βM ) values, which are consistent with the charge
deformations determined from Coulomb excitation experiments. On the basis of the “matter” and charge
deformation parameter values, the neutron deformation parameter values were also extracted. The results(see Table 1) show that all of these nuclei are largely
deformed; the deformations of the proton and neutron
distributions are similar and cannot be distinguishedat the present experimental uncertainties.

Isotope (peak)
Cross sectionβM+
Na (370 keV)
24±4 mb
0.56±0.05 (5/2+
1 → 3/2gs )+30+
Na (403 keV)
18±4 mb
0.32±0.04 (31 → 2gs )34+
Mg (685 keV)
111±37 mb
0.68±0.16 (2+1 → 0gs )+33
Mg (483 keV)
33±10 mb
0.47±0.08 (7/21 → 5/2+
gs )Table 1. Angle–integrated cross sections of the (p,p’) process corrected for detection eﬃciency and deformationsfor 30,31 Na and 33,34 Mg nuclei.
31

†
∗1
∗2
∗3
∗4
∗5
∗6

βC
0.66±0.16
0.41±0.10
0.58±0.06
0.52±0.12βn0.54±0.07
0.30±0.05
0.70±0.13
0.46±0.10

Condensed from article in Phys. Rev. C73, 044314 (2006)
Insitute of Nuclear Research (ATOMKI)
Rikkyo University
Institut de Physique Nucléaire
University of Tokyo
Kyoto University
University of Tsukuba-71

RIKEN Accel. Prog. Rep. 40 (2007)

Proton inelastic scattering on very neutron-rich 36 Mg nucleus
S. Michimasa,∗1 Y. Yanagisawa, K. Inafuku,∗2 N. Aoi, Z. Elekes,∗3 Zs. Fülöp,∗3 Y. Ichikawa, N. Iwasa,∗2
K. Kurita,∗4 M. Kurokawa, T. Machida,∗4 T. Motobayashi, T. Nakamura,∗5 T. Nakabayashi,∗5 M. Notani,∗6
H. J. Ong,∗7 T. K. Onishi,∗7 H. Otsu, H. Sakurai, M. Shinohara,∗5 T. Sumikama, S. Takeuchi, K. Tanaka,
Y. Togano,∗4 K. Yamada, M. Yamaguchi,∗8 and K. Yoneda
Nuclear reactions: 1 H(36 Mg,36 Mgγ)
60

We report here on the in-beam γ-ray spectroscopyof the very neutron-rich 36 Mg nucleus using proton inelastic scattering. The 36 Mg nucleus is located in the
middle of the shell closures of N = 20 and 28, and iscloser to the neutron drip line than nuclei belonging to
the so-called ‘island of inversion’. In previous experimental studies on neutron-rich magnesium isotopes,
32
Mg was reported to be a well-deformed nucleus1) andthe disappearance of the magicity at N = 20 was indicated. For 34 Mg, the deformation was reported tobe larger than that of 32 Mg2) . The present study isthe first experiment to investigate the low-lying excited states in 36 Mg.
The experiment was performed at the unstable nuclear beam line RIPS at RIKEN. Ions of 48 Ca wereaccelerated up to 63 MeV/nucleon using the acceleration scheme of RFQ-RILAC-CSM-RRC. The averageintensity of the primary beam was ∼80 particle nA.
The primary target was a 181 Ta plate with a thicknessof 150 µm. A radioactive 36 Mg beam was isotopicallyseparated by RIPS. The momentum acceptance was
set to be 6%. Particle identification of the secondary
beam was performed by a standard method based on
the energy deposit (∆E), time of flight (TOF), andmagnetic rigidity (Bρ). The magnetic rigidity of thefragments was deduced from the position on the first
momentum-dispersive focal plane (F1) measured using
a parallel-plate avalanche counter (PPAC). ∆E was obtained from the silicon detector arranged at the first
achromatic focus (F2), and the TOF was measured between plastic scintillators arranged at F2 and the second achromatic focus (F3). The secondary beam bombarded a liquid hydrogen target3) of 105 mg/cm2 withhavar foil windows, which was placed at F3. To obtain a sufficient mass resolution for the reaction products, the TOF spectrometer4) was placed downstreamof the secondary target. The scattered particles weredetected using a telescope arranged at the end of thebeam line, which consisted of a 100-µm silicon detector and two NaI(Tl) scintillators. The identification
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

F2-SSD ∆E [a.u]

50

A/Z=3

40

Si
36

Mg

Al

30
Mg
Na

20
Ne
F

10

0
45

O
N
C

50

55
60
F2-F3 TOF [a.u]6570Fig. 1. Identification of the particles involved in the secondary beam. The horizontal and vertical axes correspond to the TOF between F2 and F3, and to theenergy deposited in the F2 Si detector, respectively.

of the scattered particles was performed by the TOF∆E-E method. The scattering angle of the particle
was measured using three PPACs placed before andafter the secondary target. The de-excitation γ rayfrom the inelastically scattered particle was detectedusing 160 NaI(Tl) scintillators (DALI2)5) surrounding
the secondary target.
Figure 1 shows the identification of the particles
involved in the secondary beam. The 36 Mg ion was
clearly identified, and its intensity was approximately
0.3 counts per second. Data analysis is now in progress
to deduce the excitation energy of the first 2+ state andthe deformation length of 36 Mg.
References

Center for Nuclear Study, University of Tokyo
Department of Physics, Tohoku University
ATOMKI, Hungary
Department of Physics, Rikkyo University
Department of Physics, Tokyo Institute of Technology
Argonne National Laboratory, USA
Department of Physics, University of Tokyo
National Institute of Advanced Industrial Science and Technology

1) T. Motobayashi et al.: Phys. Lett. B 346, 9 (1995).
2) H. Iwasaki et al.: Phys. Lett. B 522, 227 (2001).
3) H. Ryuto et al.: Nucl. Instrum. Methods Phys. Res. A
555, 1 (2005).
4) N. Aoi et al.: RIKEN Accel. Prog. Rep. 38, 176 (2005).
5) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 36, 148(2003).

-8-

1

RIKEN Accel. Prog. Rep. 40 (2007)

Study of first excited state in 30 Ne by proton inelastic scattering
in reverse kinematics
K. Inafuku,∗1 N. Iwasa,∗1 S. Michimasa,∗2 N. Aoi, Y. Ichikawa,∗3 K. Kurita,∗4 M. Kurokawa,T. Machida,∗4 T. Motobayashi, T. Nakabayashi,∗5 T. Nakamura,∗5 M. Notani,∗6 H.J. Ong,∗3
T.K. Onishi,∗3 H. Otsu, H. Sakurai, M. Shinohara,∗5 T. Sumikama, S. Takeuchi, K. Tanaka,
Y. Togano,∗4 K. Yamada, M. Yamaguchi, Y. Yanagisawa, K. Yoneda, Z. Elekes,∗7 and Zs. Fülöp∗7
NUCLEAR REACTIONS: 1 H(30 Ne,30 Neγ)1 H

∗1
∗2
∗3
∗4
∗5
∗6
∗7

preliminary

Counts / 20 keV

The neutron-rich nucleus 30 Ne is an attractive nucleus because of its location in the region of the ‘islandof inversion’1) where the N = 20 magicity disappears
and enhanced quadrupole collectivity appears. Theenergy of the first excited state, most probably 2+ , in30
Ne has been measured by proton inelastic scattering
in reverse kinematics2) , suggesting the enhancement of
deformation. In order to improve the accuracy of theexcitation energy and transition strength, we have remeasured the proton inelastic scattering with higher
statistics and better energy resolution using a higherintensity beam and high-resolution detectors.
A radioactive 30 Ne beam was produced by the fragmentation of a 48 Ca beam at 63 MeV/nucleon witha typical intensity of 80 pnA on a 181 Ta target witha thickness of 250 mg/cm2 , and was isotopically separated by the RIKEN projectile fragment separator(RIPS). Particle identification of the secondary beam
was performed by the Bρ-TOF-∆E method using aparallel-plate avalanche counter (PPAC) placed at thedispersive focus (F1), two 100-µm-thick plastic scintillators placed at the first and last achromatic foci (F2and F3) and a 100-µm-thick silicon detector at F2. A
typical intensity of the 30 Ne beam was 1.4 cps, which
was about seven times larger than that of the previous
experiment2) .
A liquid-hydrogen target with a thickness of 105
mg/cm2 at F3 was bombarded by the 30 Ne beam.
The energy of the 30 Ne beam was 44 MeV/nucleon
at the center of the target. The de-excitation γ-rays
were detected by an array of 160 NaI(Tl) scintillators(DALI-II) that surrounded the target. The energy resolution of the Doppler-shift-corrected γ-rays at 1 MeV
from a source moving with a velocity of β ∼0.3 was
8%, which was better than the resolution of the previous experiment (12%). The reaction products werecollected by the superconducting triplet quadrupole
magnet (STQ)3) and their charge (Z) and mass (A)were identified by the TOF-∆E-E method. TOF was

Energy [keV]

Fig. 1. Doppler-shift-corrected γ-ray spectra measured incoincidence with scattered 30 Ne particle.

measured using two 100-µm-thick plastic scintillatorsplaced 3.8 m apart. ∆E and E were measured using
a 320-µm-thick silicon detector and two 120-mm-thick
NaI(Tl) detectors placed at the focus of STQ. The resolution of the charge and mass were measured to be
0.16 and 0.37 in σ, respectively.
Figure 1 shows the Doppler-shift-corrected γ-ray energy spectrum measured under the condition that bothbeam particles and reaction products were identified to
be 30 Ne. Only the events with the γ detection multiplicity = 1 were employed in the spectrum. In the
spectrum, a prominent γ peak was clearly observed.
The energy was preliminarily deduced to be 799±12keV, which is consistent with the result of the previous experiment (791±26 keV) but with much better
accuracy. Further analysis is now in progress for accurate determination of the transition strength.
References
1) E. K. Warburton et al.: Phys. Rev. C 41, 1147 (1990).
2) Y. Yanagisawa et al.: Phys. Lett. B 566, 84 (2003).
3) K. Kusaka et al.: IEEE Trans. Appl. Supercond. 14,
310 (2004).

Department of Physics, Tohoku University
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Department of Physics, Rikkyo University
Department of Physics, Tokyo Institute of Technology
Argonne National Laboratory
Institute of Nuclear Research of the Hungarian Academy of
Science-91

RIKEN Accel. Prog. Rep. 40 (2007)

Proton single-particle states in neutron-rich 23F nucleus
S. Michimasa,∗1 S. Shimoura,∗1 H. Iwasaki,∗2 M. Tamaki,∗1 S. Ota,∗1 N. Aoi, H. Baba, N. Iwasa,∗3 S. Kanno,
S. Kubono,∗1 K. Kurita,∗4 M. Kurokawa, T. Minemura,∗5 T. Motobayashi, M. Notani,∗6 H. J. Ong,∗2
A. Saito,∗2 H. Sakurai, S. Takeuchi, E. Takeshita, Y. Yanagisawa, and A. Yoshida
Nuclear reactions: 4 He(22 O,23 F∗ ), 4 He(23 F,23 F∗ ), 4 He(24 F,23 F∗ ), 4 He(25 Ne,23 F∗ ), Singleparticle state, In-beam γ-ray spectroscopy

†
∗1
∗2
∗3
∗4
∗5
∗6

Condensed from the article in Phys. Lett. B 638, 146 (2006)
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Department of Physics, Tohoku University
Department of Physics, Rikkyo University
National Cancer Center
Argonne National Laboratory, USA

1706(21)

Ex [keV] Cross-section

6905(41)6629(24)6365(54)2644(49)

1711(8)1240(12)3858(24)4059(11)4732(59)

2003(12)3378(11)1696(25)913(7)

2920(3)(3/2+)

Relative3445(54)3985(41)Jπ2268(12)We have reported in-beam γ-ray spectroscopy of23
F using the proton transfer 4 He(22 O,23 F∗ ), theα inelastic scattering 4 He(23 F,23 F∗ ), the neutronknockout 4 He(24 F,23 F∗ ), and the two-nucleon knockout 4 He(25 Ne,23 F∗ ) reactions1) . In this paper, we discuss the proton shell structure in a neutron-rich 23 F
nucleus on the basis of the cross sections of these reactions for each excited state. This study is the first
application of the proton transfer reaction on an unstable nucleus to in-beam γ-ray spectroscopy.
The experiment was performed at the RIPS beamline in RIKEN. The ions of 40 Ar were accelerated up
to 63 MeV/nucleon using the acceleration scheme of
RFQ-RILAC-CSM-RRC. The average intensity of the
primary beam was ∼500 particle nA. The primary target was a 1-mm-thick 9 Be plate. The secondary beam
was a cocktail of 22 O, 23 F, 24 F and 25 Ne, and it bombarded a 100-mg/cm2-thick liquid helium target2) withhavar foil windows. The reaction products were identified using a telescope consisting of 9 SSDs and 36
NaI(Tl) scintillators.3) The scattering angles of the reaction products were measured using three PPACs.
De-excitation γ rays from the reaction products weredetected using 150 NaI(Tl) scintillators (DALI2)4) surrounding the secondary target.
In the analysis, we examined the coincidences ofmultiple γ rays in these reactions and reconstructedthe γ-decay scheme in 23 F, as shown in Fig. 1. The
level energies with underlines show newly observed excited states in the present experiment. The bar graphson the right side of the excitation energies show the relative cross sections for populating these excited states.
In these relative cross sections, one can observe thatthe 2268- and 4059-keV states are strongly populatedby the proton transfer reaction, but negligibly populated by the neutron knockout reaction. This strongly
suggests that these states have a proton single-particle
nature. Furthermore, the cross sections for these statesin α inelastic scattering may indicate that the 2268 and4059 keV states have the proton single-particle configurations of s1/2 and d3/2 , respectively. These con-

(1/2+)

5564(49)5544(11)4923(12)4732(59)4618(16)4059(11)3964(28)3858(24)3833(8)3378(11)2920(3)2268(12)(22O,23F)(23F,23F)(24F,23F)(25Ne,23F)

5/2+

F

23

0

Fig. 1. Proposed level and γ-decay scheme in 23 F. The
level energies with underlines show excited states newly
observed in the present experiment. The spin-parities
with underlines were assigned by the angular distributions from the proton transfer reaction. The bars on
the right side of excitation energies show the relative
cross sections to populate these states.

figurations are consistent with the angular momenta
for these states deduced from angular distributions of
scattered 23 F ions.
The excitation energies of these proton singleparticle states are compared with the shell-model calculations on the basis of the USD5) and SDPF-M6) effective interactions. These states are located at higher
energies than the predictions by ∼ 500 keV, althoughother states correspond to the predictions within 100
keV. This may indicate that the shell gaps of d5/2 -d3/2
and d5/2 -s1/2 in 23 F are wider than those in stable nuclei.
References
1) S. Michimasa et al.: Phys. Lett. B 638, 146 (2006).
2) H. Ryuto et al.: Nucl. Instrum. Methods Phys. Res. A
555, 1 (2005).
3) M. Tamaki et al.: CNS-REP-59, 76 (2003).
4) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 36, 148(2003).
5) B. H. Wildenthal et al.: Prog. Part. Nucl. Phys. 11, 5(1984).
6) Y. Utsuno et al.: Phys. Rev. C 60, 054315 (1999).

- 10 -

1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

Vanishing N =20 shell gap: study of excited states in 27,28 Ne
Z. Elekes,∗1 Zs. Dombrádi,∗1 A. Saito,∗2 N. Aoi, H. Baba,∗2 K. Demichi,∗2 Zs. Fülöp,∗1 J. Gibelin,∗3 T. Gomi,∗2
H. Hasegawa,∗2 N. Imai,∗4 M. Ishihara, H. Iwasaki,∗4 S. Kanno,∗2 S. Kawai,∗2 T. Kishida, T. Kubo, K.
Kurita,∗2 Y. Matsuyama,∗2 S. Michimasa,∗4 T. Minemura, T. Motobayashi, M. Notani,∗4 T. Ohnishi,∗4 H.J.
Ong,∗4 S. Ota,∗5 A. Ozawa,∗6 H.K. Sakai,∗2 H. Sakurai, S. Shimoura,∗4 E. Takeshita,∗2 S. Takeuchi, M.
Tamaki,∗4 Y. Togano,∗2 K. Yamada,∗2 Y. Yanagisawa, and K. Yoneda,[NUCLEAR STRUCTURE, Unstable nuclei, γ-ray spectroscopy]
The aim of this work was to investigate the N =20
shell gap by studying the 27 Ne and 28 Ne nuclear structures. By detecting their low–lying bound excitedstates, we intended to answer whether N =20 is a magic
number far from stability by comparing the experimental results with theoretical calculations. In this experiment, a 94 A·MeV energy primary beam of 40 Ar withan intensity of 60 pnA hit a 181 Ta production target of
0.5 cm thickness. Reaction products were momentum
and mass analyzed using the RIPS fragment separator. The secondary beam included neutron-rich 24 O,
25,26,27
F, 27,28,29,30 Ne and 29,30,31,32 Na nuclei. The
RIPS was operated at a momentum acceptance of 6%. The total intesity was approximately 100 cps. Incident beam species were identified on the basis of energy
loss, time of flight and magnetic rigidity (Bρ). The
secondary beam was transmitted to a liquid hydrogentarget at the final focus of the RIPS. The average areal
density of the hydrogen target was 210 mg/cm2 . The
position of the incident particles was determined using
two PPACs placed at F3 upstream of the target. The
scattered particles were detected and identified using a
PPAC and a silicon telescope. The telescope consistedof three layers with thicknesses of 0.5, 0.5 and 1 mm.
Z identification was performed by a TOF-energy loss
method. On the basis of ∆E-E information, isotope
separation was carried out among the different neon
isotopes. The DALI2 setup, including 146 NaI(Tl)scintillator detectors, was used to surround the target
to detect de–exciting γ rays emitted by the inelastically scattered nuclei. In Fig. 1, the resulting γ–ray
spectra can be observed. Determining the cross sections of γ-rays in 28 Ne, and using the previously measured B(E2), the neutron and proton transition matrix
elements were deduced by DWBA analysis. The neutron transition probability was found to be more or lessenhanced compared with pure sd shell model calculations depending on the effective charge. The numberof bound excited states observed in 27 Ne by knocking
†
∗1
∗2
∗3
∗4
∗5
∗6

Condensed from article in Phys. Rev. Lett. 96, 182501(2006)
Insitute of Nuclear Research (ATOMKI)
Rikkyo University
Institut de Physique Nucléaire
University of Tokyo
Kyoto University
University of Tsukuba

Fig. 1. Doppler-corrected spectra of γ rays emerging from1
H(28 Ne,28 Ne) (a) and 1 H(28 Ne,27 Ne) (b) reactions.
The solid line is the final fit including the spectrum curves from GEANT4 simulation and additionalsmooth polynomial backgrounds plotted as dotted lines
for each nucleus.

out a neutron from 28 Ne was observed to be larger thanthat predicted using the sd shell model. The presenceof a low-lying extra state intruding from the upper f p
shell can be considered as an indication of a strongly
reduced N =20 shell gap.

- 11 1

RIKEN Accel. Prog. Rep. 40 (2007)

Electric quadrupole moment of 31Al
D. Nagae,∗1 H. Ueno, D. Kameda, M. Takemura,∗1 K. Asahi,∗1 K. Takase,∗1 A. Yoshimi, T. Sugimoto,
T. Nagatomo, M. Uchida,∗1 K. Shimada,∗1 T. Arai,∗1 T. Inoue,∗1 S. Kagami,∗1 N. Hatakeyama,∗1
H. Kawamura,∗2 and K. Narita∗2[Nuclear structure, spin-polarized RI beam, electric quadrupole moment, β-NQR method]

∗1
∗2

1.000
0.998

R’/R

In a region of island of inversion, nuclei are known tohave a deformed shape. Neutron-rich Al isotopes, located near the borderline of the island of inversion, areimportant nuclei in investigating the mechanism of inversion. The electric quadrupole moment (Q moment)is sensitive to nuclear deformation. We have measured the Q moment of 31 Al by a β-detected nuclearquadrupole resonance (β-NQR) method.
An 31 Al beam was obtained from the fragmentation of 40 Ar projectiles at an energy of E =95 MeV/nucleon on a 93 Nb target of 0.37 g/cm2 thickness. To obtain a spin-polarized 31 Al beam, the emission angle and outgoing momentum were selected1) .
Thus, fragments emitted at angles θ = 1.3◦ – 5.7◦ were
accepted by RIPS using a beam swinger installed upstream of the target. A range of momentum 0.99p0 –1.05p0 , where p0 = 12.4 GeV/c is a peak position in
the momentum distribution, was selected by a slit at
the momentum-dispersive focal plane. Spin-polarizedfragments were introduced into the NQR apparatus
located at the ﬁnal focus. The experimental setup
around a stopper was almost similar to that used ina µ-moment experiment2) . 31 Al ions were implanted
in an α-Al2 O3 single-crystal stopper to which the static
magnetic ﬁeld B0 ∼ 500 mT was applied from bottom
to top to maintain spin polarization. The angle θc-axis
between the crystal c-axis and the B0 direction was set
at θc-axis = 0◦ .
In the β-NQR method, β-rays emitted from the implanted fragments were detected with plastic scintillator telescopes located above and below the stopper. The up/down ratio R of β-ray counting rates
was expressed as R ≈ a(1 + 2Aβ P ) when Aβ P was
small (Aβ P  1), where a is a constant factor representing asymmetries in counter solid angles and efﬁciencies. The spin reversal P to −P was detected
through a corresponding change, R ≈ a(1 + 2Aβ P ) toR ≈ a(1 − 2Aβ P ). When the polarization was alteredby a resonant spin change, a change appeared at theratio R /R ≈ 1 − 4Aβ P . Thus, the resonant frequency
νQ = eqQ/h was derived from the observed peak or
dip in a β-NQR spectrum, where eq, Q, and h denotethe electric ﬁeld gradient, the Q moment, and Planck’s
constant, respectively.
The Q moment was obtained using the electric ﬁeld
gradient eq = 70.9(5) × 1019 V/m2 at an Al site in an

0.996
0.994
0.992
0.990
0.988

500 1000 1500 2000 2500 3000 3500

νQ [kHz]

Fig. 1. NQR spectra obtained for 31 Al implanted in a αAl2 O3 stopper. The R /R values are plotted as a function of the parameter ν Q .

α-Al2 O3 sample3) . Figure 1 shows the β-NQR spectra
obtained for the ground states of 31 Al with the sweep
width ν Q = 411 kHz.The vertical and horizontal
axes denote the R /R ratio and νQ , respectively. Here,the horizontal bar indicates ν Q , whereas the verticalbar shows a statistical error in the R /R ratio. The
quadrupole coupling constant of 31 Al in α-Al2 O3 wasmeasured to be νQ = 1786(98) kHz. The Q moment of
31
Al was determined to be |Q(31 Al)| = 104(7) e·mb.
The obtained |Q(31 Al)| is smaller than that of obtained by shell model calculation performed using thecode OXBASH4) with USD interaction5) . The protonand neutron eﬀective charges ep = 1.3 and en = 0.5
were used. The theoretical Q moment of 31 Al is
151 e·mb. A notable diﬀerence between the theoretical and experimental Q moments is observed. The
sd-space shell model calculation is known to underestimate the Q moments of the nuclei in the region ofisland of inversion, since the N = 20 shell closure does
not occur in these nuclei. The observed Q moment
is even smaller than that obtained by sd-shell calculation. This ﬁnding indicates that 31 Al is located outside the island of inversion. Further analyses are now
in progress.
References

Department of Physics, Tokyo Institute of Technology
Department of Physics, Rikkyo University- 12 -

1) K. Asahi et al.: Phys. Lett. B 251, 488 (1990).
2) H. Ueno et al.: Phys. Lett. B 615, 186 (2005).
3) D. Sundholm et al.: Phys. Rev. Lett. 68, 927 (1992).
4) B.A. Brown, A. Etchegoyen, and W.D.M. Rae :OXBASH, MSU Cyclotron Laboratory Report No.
524, 1986.
5) B.H. Wildenthal: Prog. Part. Nucl. Phys. 11, 5 (1984).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Test experiment on 32m Al isomeric moment

Al beam

aI

2

10

5

10

4

10

3

10

2





125
100
75
50
25
00

)G
100

200

time (ns)

0C+



)G

10
0

500

300



1000

1500




2000

Energy (keV)
Fig. 2. Energy spectrum for Ge2 and NaI2, and 222 keV
decay spectrum for Ge2.

nium detectors beside and behind the stopper to obtain γ-ray energies, in particular, for the background
events. The thin plastic scintillator (F3PL in Fig. 1)
located 20 cm upstream of the stopper was used in order to provide t = 0 signals, “32 Al coming”, for thesubsequent γ-decay. We collected only γ events in coincidence with a 1.5 µs time window of t = 0 signals.
Each photomultiplier connected to the NaI scintillator
was housed in a 2 mm-thick µ-metal magnetic shield,
and its head was set about 100 cm from the center ofthe magnet pole to eliminate the influence of the magnetic field.
Energy spectra for Ge2 and NaI2 are shown in
Fig. 2. 222 keV and 735 keV γ-rays can clearly beseen. Also, several other peaks were assigned: 511 keV
as the positron-electron annihilation, 846.8 keV as theprompt γ-ray from the 56 Fe 2+
1 state, and 1572.3 keV,
1847.0 keV and 1941.4 keV for the β-delayed γ fromthe beam contaminations (35 P,33 Si and 32 Al), respectively. The decay spectrum of Ge2 obtained with agate of 222 keV is also shown in Fig. 2. We derived
T1/2 = 196(16) ns, which is in good agreement with
200(20) ns5) . The high background levels of the NaI
scintillators prevented us from determining a precise
half life. Background elimination and other analyses
are now in progress.

1) H. Ueno et al.: Phys. Lett. B 615, 186 (2005).
2) K. Kameda et al.: Phys. Lett. B 647, 93 (2007).
3) G. Neyens. et al.: Phys. Rev. Lett. 94, 022501 (2005).
4) T. Motobayashi et al.: Phys. Lett. B 346, 9 (1995).
5) M. Robinson et al.: Phys. Rev. C 53, R1465 (1996).
6) G. Goldring et al.: in Treatise in Heavy Ion Sciences,edited by D. E. Bromley (Plenum Press, New York,
1985), Vol. 3, p. 539.

Ge1
Magnet pole

3

aI
Ge2

6

References

Magnetic shield
Glass

q
q

N

F3PL
Si stopper

q
q

N

1

F2PL

aI

32

N

Collimeter
Degrader4

Department of Physics, Tokyo Institute of Technology
Department of Nuclear Physics, The Australian National
University, Australia

aI

∗2

N

∗1

10

countsIn previous β-NMR studies, the magnetic1) and electric quadrupole moments2) of 32 Al were found to bewell described by the normal sd-shell structure, in contrast to the neighbors, namely, 31 Mg and 32 Mg, which
are reported to be strongly deformed nuclei3,4) . However, the spacing and ordering of the low-lying excitedlevels of 32 Al including the 957 keV isomeric state of
T1/2 = 200(20) ns5) were not reproduced well by theconventional sd-shell models, suggesting the presenceof a pf -intruder structure with low excitation energies.
To obtain further information on the wave functionsof the low-lying excited levels of 32 Al, we introduce
a measurement of the g-factor of the isomeric stateusing the time differential perturbed angular distribution (TDPAD) method6) . We have thus constructeda prototype setup for this purpose, and obtained theγ-decay spectrum of 32m Al.
The experiment was performed at the RIKEN Ring
Cyclotron. 32 Al nuclei were produced through the
projectile fragmentation reaction of a 95 MeV/nucleon
40
Ar primary beam with a 369 mg/cm2 -thick Nb target and were selected in RIPS. We restricted theemission angles of 32 Al fragments in the region µ =¡1.0– ¡ +3.4 – , and their momenta were apporoximately pc =12.5 GeV/c with an acceptance of ±3 %,in which pc corresponded to the peak of the fragment yield. The 32 Al nuclei were implanted into asingle-crystal-Si stopper placed between the poles ofan electromagnet that provided a static magnetic fieldB0 ∼0.5 T in the reaction normal. A schematic drawing of the setup is shown in Fig. 1. The two γ-raylines, namely, 222 keV and 735 keV, cascading from the957 keV isomeric state via the intermediate energy levelof 735 keV were detected using four 5.500 ×5.500 NaI(Tl)scintillators located around the stopper as shown in
Fig. 1. We also used two coaxial high-purity germa-countsK. Takase,∗1 D. Kameda, H. Ueno, Y. Kobayashi, A. Yoshimi, T. Sugimoto, T. Nagatomo, K. Shimada,∗1 D.
Nagae,∗1 M. Takemura,∗1 T. Inoue,∗1 T. Arai,∗1 M. Uchida,∗1 H. Watanabe∗2 , and K. Asahi£¤
nuclear structure, TDPAD, isomer, 32 Al, neutron-rich nuclei

Fig. 1. Setup and geometry of detectors.

- 13 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Direct capture component in 26 Si(p,γ)27 P reaction
Y. Togano,∗1 T. Gomi,∗2 T. Motobayashi, Y. Ando,∗1 N. Aoi, H. Baba, K. Demichi,∗1 Z. Elekes,∗3
N. Fukuda, Zs. Fülöp,∗3 U. Futakami,∗1 H. Hasegawa,∗1 Y. Higurashi, K. Ieki,∗1 N. Imai,∗4 M. Ishihara,
K. Ishikawa,∗5 N. Iwasa,∗6 H. Iwasaki,∗7 S. Kanno, Y. Kondo,∗5 T. Kubo, S. Kubono,∗8 M. Kunibu,∗1
K. Kurita,∗1 Y. U. Matsuyama,∗1 S. Michimasa, ∗8 T. Minemura, ∗9 M. Miura,∗5 H. Murakami,∗1
T. Nakamura,∗5 M. Notani,∗10 S. Ota,∗8 A. Saito,∗8 H. Sakurai, M. Serata,∗1 S. Shimoura,∗8 T. Sugimoto,
E. Takeshita, S. Takeuchi, K. Ue,∗7 K. Yamada, Y. Yanagisawa, K. Yoneda, and A. Yoshida£ 208¤
Pb(27 P,p26 Si)208 Pb, Coulomb dissociation, Nuclear astrophysics
The stellar 26 Si(p,γ)27 P reaction has been investigated by analyzing the Coulomb dissociation of 27 P.
The galactic γ line at 1.8 MeV associated with 26 Al
β decay is observed using satellite telescopes1) . This
reaction is suggested to affect the synthesis of 26 Al innovae and X-ray bursts. Direct proton capture is particularly important at stellar temperatures lower than
0.1 GK. The astrophysical S-factor was deduced by
Guo et al. from the asymptotic normalization coefficients (ANCs) of the mirror nucleus 27 Mg2) . Caggiano
et al. estimated the S-factor using a shell model calculation3) . In this report, these estimates are compared with the result experimentally obtained by the
Coulomb dissociation of 27 P.
The experiment was performed using RIPS at the
RIKEN Accelerator Research Facility. Details of theexperimental setup are described in Ref. 4. The relative p-26 Si energy spectrum is shown in Fig. 1. The
filled circles represent the experimental data. The solid
curve shows the best fit with five components shownby the dotted and dashed curves. The detector responses were obtained using a Monte-Carlo simulation.
Four resonant breakup components are represented by
the dotted curves. The peak at 0.31 MeV corresponds
to the known first excited state at 1.2 MeV in 27 P3) .
The bump at around 1 MeV is due to the known second excited state at 1.6 MeV and an unknown one at
2.0 MeV. The peak at 2.1 MeV is also due to an unknown one at around 3 MeV. The results of the resonant state are described in Ref. 4. The direct breakup
component, which is shown by the dashed curve, corresponds to the direct proton capture process in the26
Si(p,γ)27 P reaction.
An energy-independent E1 S-factor is assumed in
the calculation of the direct breakup component. The∗1

Department of Physics, Rikkyo University
National Institute of Radiological Sciences∗3 Institute of Nuclear Research of the Hungarian Academy of
Sciences (ATOMKI), Hungary∗4 Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)∗5 Department of Physics, Tokyo Institute of Technology∗6 Department of Physics, Tohoku University∗7 Department of Physics, University of Tokyo∗8 Center for Nuclear Study, University of Tokyo∗9 National Cancer Center∗10 Argonne National Laboratory, USA∗2- 14 -

dot-dashed curve shows the calculated results using the
S-factors deduced by Guo et al.2) (8.7 ×10−2 MeV b)
and Caggiano et al.3) (3.6 ×10−2 MeV b), respectively.
Both calculated results are significantly larger than thepresent result of direct breakup component, suggestinga lower reaction rate at T < 0.1 GK. The preliminarily
extracted S-factor is 1.2 ×10−2 MeV b. In this analysis, we cannot resolve possible resonances in higher
relative energies; thus, this result is regarded as an
upper bound of the direct component. Therefore, theambiguity in this result cannot explain the difference
among the three results shown in Fig. 1, suggesting
uncertainties in the shell model calculation or in theprocedure used to extract the S factor from the ANCof the mirror nucleus.

Fig. 1. Relative energy spectrum of 27 P breakup on Pb(filled circles). The data were fitted by taking into
account the detector responses. The solid and dotted curves represent the best fit and individual components, respectively. The dashed curve denotes the direct breakup component. The dot-dashed curves show
the calculated direct breakup component using the Sfactors derived by Guo et al. and Caggiano et al.

References
1) R. Diehl et al.: Astron. Astrophys. Suppl. 97, 181(1993).
2) B. Guo et al.: Phys. Rev. C 73, 048801 (2006).
3) J. A. Caggiano et al.: Phys. Rev. C 64, 025802 (2001).
4) Y. Togano et al.: Eur. Phys. J. A 27, s01, 233 (2006).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Study of astrophysically important resonant states in 26 Si by
28
Si(4 He,6 He)26 Si reaction†
Y. K. Kwon,∗1 C. S. Lee,∗1 J. Y. Moon,∗1 J. H. Lee,∗1 J. Y. Lee,∗1 S. Kubono,∗2 N. Iwasa,∗3 K. Inafuku,∗3 H.
Yamaguchi,∗2 J. J. He,∗2 A. Saito,∗2 Y. Wakabayashi,∗2 H. Fujikawa,∗2 G. Amadio,∗2 L. H. Khiem,∗4 M.
Tanaka,∗5 A. Chen,∗6 S. Kato, ∗7 Y. Fuchi, ∗5 and N. Fukunishi ∗8[Nuclear astrophysics, Two-nucleon transfer reaction, Magnetic spectrograph]
The emission of 1.809 MeV gamma ray from the firstexcited state of 26 Mg followed by the β decay of 26 Al
in its ground state (denoted as 26 Alg.s. ) has been identified by gamma-ray telescopes such as those in theCompton Gamma-Ray Observatory (CGRO)1) . To resolve the controversy over the possible sources of theobserved 1.809 MeV gamma rays, one needs knowledgeof the production rate of 26 Al. One possible source ofthe production of 26 Alg.s. is nova explosion2) . Under
the explosive hydrogen burning conditions in a nova
site, production proceeds via the reaction sequence25

Al(β + ν)25 M g(p, γ)26 Alg.s. (β + ν)26 M g ∗ (γ)26 M g g.s. .

However, if the proton capture rate on 25 Al is fasterthan the β-decay rate of 25 Al, the above reaction sequence is bypassed by the25

Al(p, γ)26 Si(β + ν)26 Alm (β + ν)26 M g g.s.

reaction sequence. By shell model calculations andmirror nucleus consideration using past data, Illiadis etal.3) suggested that the 25 Al(p, γ)26 Si reaction should
be predominated by the 3+ unnatural parity state(Ex =5970(100) keV). Recent studies of 28 Si(p,t)26 Si4) ,24
Mg(3 He,nγ)26 Si5) , and 29 Si(3 He,6 He)26 Si6) reduced
the uncertainties in the 26 Si levels above the proton
threshold and identified new states as candidates forthe unnatural parity states. However, for such candidates, they4–6) could not make any spin assignment directly using angular distribution measurement. In thiswork, we decided to study the astrophysically important resonant states in 26 Si via the 28 Si(4 He,6 He)26 Si
reaction, which could excite an unnatural parity state
directly, in contrast with the (p,t) reaction, which cannot excite an unnatural parity state.
The 28 Si(4 He,6 He)26 Si reaction was studied using a high-resolution QDD(quadrupole-dipole-dipole)type magnetic spectrograph (PA) at the Center for
Nuclear Study (CNS), University of Tokyo. A beam
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Department of Physics, Chung-Ang University, Korea
CNS, Graduate School of Science, University of Tokyo
Department of Physics, Tohoku University
Institute of Physics and Electronics, Vietnam
KEK (The High Energy Accelerator Organization)
Department of Physics and Astronomy, McMaster University, Canada
Department of Physics, Yamagata University
RIKEN

Table 1. Candidates for 3+ resonant state with previous
results.
(p, t) [4](3 He, nγ) [5] (3 He,6 He) [6] This work
Ex (keV ) J π Ex (keV ) J π Ex (keV ) J π Ex (keV )5916(2) 0+ 5912(4) 3+
5918(8)5946(4) 0+ 5945(8) 3+

of 4 He at 120 MeV was extracted from RIKEN linear
accelerator (RILAC) + RIKEN ring cyclotron (RRC).
The beam intensity was typically 70 enA at the target position. A self-supporting natural silicon target(thickness ∼ 1 mg/cm2 ) was used to populate states in
26
Si. The focal plane detection system consisted of a
hybrid gas counter and plastic scintillators. Four proportional gas counters, namely, two position counters(X1 and X2) and two energy loss counters (∆E1 and∆E2) were installed in the hybrid drift chamber.
To obtain information on the level structure in 26 Si,
we have measured the angular distribution at θlab =8◦ , 11◦ , 15◦ , and 20◦ . The overall energy resolution
was 100 keV (FWHM). The excitation energies below Ex = 5.5 MeV are well in agreement with thosefrom previous experimental results4–6) . For the 3+ resonant state, the study of the (3 He,6 He) reaction6) suggested the spin-parity assignment of 3+ for the 5945
keV state by Coulomb shift calculation. The study ofthe (3 He,nγ) reaction5) suggested 5912 keV as a 3+
resonant state from the comparison of the measured
differential cross section with the Hauser-Feshbach calculations. However, in the (p, t) reaction study4) , a
5916 keV was assigned directly as a 0+ state by the
distorted-wave Born approximation (DWBA) analysis.
We observed a 5918 keV state in our measurement. To
clarify this level of information clearly, spin-parity assignment by DWBA calculation is in progress. We also
observed several candidates for unnatural parity states
at 5612 keV, 5825 keV, 6004 keV, and 6107(8) keV.
References
1) N. Prantzo and R. Diehl; Phys. Rep. 267, 1 (1996).
2) R. D. Gerhz, J. W. Truran, R. E. Williams, and S. Starrfield; Publ. Astron. Soc. Pac. 110, 3 (1998).
3) C. Illiadis et al.; Phys. Rev. C 53, 475 (1996).
4) D. Bardayan et al.; Phys. Rev. C 65, 032801(R)(2002).
5) Y. Parpottas et al.; Phys. Rev. C 70, 065805 (2004).
6) J. A. Caggiano et al.; Phys. Rev. C 65, 055801 (2002).

- 15 1

RIKEN Accel. Prog. Rep. 40 (2007)

Cluster structures of even-even oxygen isotopes
N. Furutachi,∗1 M. Kimura,∗2 and S. Oryu ∗1[Nuclear structure, cluster structure, unstable nuclei]

∗1
∗2

18

+

18

-

20

+

20

-

O K =0

excitation energy [MeV]O K =0Exp.

24

O K =0O K =018

O K =0

+

20
16
12
8
4
0

10

20

30

40

50

J(J+1)
4

4

2

2

Y [fm]

Y [fm]The importance of the cluster structure in unstable nuclei has been revealed through the studies of the
2α-clustering of neutron-rich Be isotopes. Oxygen isotopes are interesting targets for investigating the clustering systematics in unstable and N̸=Z stable nuclei,
because 16 O has the well-established 12 C+α structure
in its excited state.
It has been known for a long time that the deformed
4p-2h conﬁguration coexists with the ordinary (sd)2shell model space in the low-lying states of 18 O. There
have been many investigations on the 14 C+α structure of 18 O both in theory1) and in experiment2) , andthe importance of the 14 C+α structure of 18 O has been
revealed. The next question is whether or not the cluster correlation survives in 20 O. The cluster correlation
may survive as in the case of 12 Be. However, there has
been no investigation on the cluster structure of 20 O,
although the coexistence of the 6p-2h conﬁguration in
the low-lying states of 20 O is suggested3) .
We have investigated the cluster structures of 18 O
and 20 O, using the AMD+GCM framework. The AMD
can describe the cluster structure together with theshell-like structure without any assumption on nuclear
structure. Therefore, this framework is appropriate forinvestigating the cluster structure in unstable nuclei.
We have obtained excited rotational bands that havethe cluster structures in 18 O and 20 O. The obtained
rotational bands are shown in Fig. 1, and the density distributions of the intrinsic wave functions, which
dominantly construct the bands, are also shown. We
have found the 14 C+α cluster structure in 18 O. The
Kπ =0+ band dominantly has the 14 C+α cluster structure, and the moment of inertia approximately agrees
with that of the experimental candidates. Although
the cluster state is fragmented into several states, theKπ =0− band also has the 14 C+α cluster structure.
The Kπ =0− band can be regarded as the parity doublet partner of the Kπ =0+ band. We have found more
complicated structures in 20 O. The Kπ =0+ rotationalband is obtained from the mixing of the 12 C+α+4nlike and 14 C+6 He-like cluster structures. The excitation energy of this state is much smaller than the
14
C+6 He threshold energy. The 14 C+6 He-like cluster
structure also contributes to the Kπ =0− band. Although mixing with the 12 C+α+4n-like structure isnot seen in the Kπ =0− band, this band can be regarded as the parity doublet partner of the Kπ =0+band. Furthermore, the 16 C+α cluster structure has

0

-2

-2

-4
-6 -4 -20-4
02
Z [fm]

4

6

8-6 -4 -2

0
2
Z [fm]

4

6

8

Fig. 1. Excited rotational bands of 18 O and 20 O. The matter density distributions of the intrinsic states that contribute to the Kπ =0+ band of 18 O (left side) and 20 O
(right side) are also shown. The centers of the singleparticle wave packet are plotted with density distributions using squares.

been obtained. The 16 C+α cluster structure also constructs the parity doublet Kπ =0+ and 0− bands.
References
1) P. Descouvemont and D. Baye: Phys. Rev. C 31, 2274
(1985).
2) D. R. Tilley, H. R. Weller, C. M. Cheves, and R. M.
Chasteler: Nucl. Phys. A 595, 1 (1995).
3) S. LaFrance, H. T. Fortune, S. Mordechai, M. E.
Cobern, G. E. Moore, R. Middleton, W. Chung, andB. H. Wildenthal: Phys. Rev. C 20, 1673 (1979).

Department of Physics, Tokyo University of Science
Institute of Physics, Tsukuba University- 16 1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

Search for neutron decoupling in 22 O via (d,d’γ) reaction
Z. Elekes,∗1 Zs. Dombrádi,∗1 S. Bishop, Zs. Fülöp,∗1 J. Gibelin,∗2 T. Gomi, Y. Hashimoto,∗3 N. Imai, N.
Iwasa,∗4 H. Iwasaki,∗5 G. Kalinka,∗1 Y. Kondo,∗3 A.A. Korsheninnikov,∗8 K. Kurita,∗6 M. Kurokawa, N.
Matsui,∗3 T. Motobayashi, T. Nakamura,∗3 T. Nakao,∗5 E.Yu. Nikolskii,∗8 T.K. Ohnishi,∗5 T. Okumura,∗3 S.
Ota,∗7 A. Perera, A. Saito,∗5 H. Sakurai,∗5 Y. Satou,∗3 D. Sohler,∗1 T. Sumikama, D. Suzuki,∗5 M. Suzuki,∗5 H.
Takeda,∗7 S. Takeuchi, Y. Togano∗6 and Y. Yanagisawa[NUCLEAR STRUCTURE, Unstable nuclei, gamma-ray spectroscopy]
The experiment was performed in RIKEN where a
94 A·MeV energy primary beam of 40 Ar with 60 pnA
intensity hits a 9 Be production target of 0.3 cm thickness. The reaction products were momentum and mass
analyzed by the RIPS fragment separator. The total
intensity was approximately 1500 cps having an average 22 O intensity of 600 cps. The identification ofincident beam species was performed by energy loss
and time-of-flight. The secondary beam was transmitted to a secondary CD2 target of 30 mg/cm2 at the
final focus of RIPS. The reaction occurred at an energy of 34 A·MeV. The position of the incident particles was determined by two PPACs placed at F3 upstream of the target. The scattered particles were detected and identified by a 2 x 2 matrix silicon telescope
placed 96 cm downstream of the target. 80 NaI(Tl)scintillator detectors surrounded the target to detectde–exciting γ rays emitted by the inelastically scattered nuclei. In Fig. 1. the Doppler–corrected γ–ray
spectra of 22 O nucleus is presented. The position of
the single peak was determined at 3185(15) keV. The
above energy for 22 O is in a good agreement with the3199(8) keV determined earlier1) . After the peak position has been determined, we calculated the cross sec+tion for the 22 O+2 H reaction to be σ(0+1 → 21 )=19±3
mb. From a distorted wave analysis, we derived the“matter” deformation length to be δM =0.77±0.07 fm,
which corresponds to a moderate mass deformation ofβM =0.23±0.02. We can compare this result with thedata from the 22 O+197 Au reaction2) where the proton
deformation βp was derived to be between 0.2 and 0.24.
This means that the neutron deformation of 22 O isvery similar to the proton deformation taking into account the mass deformation determined in this study.
This result is in contrast with the expectations thatthe increasing neutron number may lead to a stronger
neutron decoupling. In reality, the Mn /Mp ∼ βn /βpratios are 2, 3 and 1 for 18 O, 20 O and 22 O, respectively.
The increasing trend is suppressed by the N =14 sub†
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Fig. 1. Doppler-corrected spectra of γ rays emerging from22
O+CD2 reaction. The solid line is the final fit including the spectrum curve from GEANT4 simulation andan additional smooth polynomial background is plotted
as a separate dotted line.

shell closure, which makes both the proton and neutron
distributions nearly spherical in 22 O.
References
1) M. Stanoiu et al.: Phys. Rev. C69, 034312 (2004).
2) P. G. Thirolf et al.: Phys. Lett. B485, 16 (2000).

Condensed from article in Phys. Rev. C71, 017306 (2006)
Institute of Nuclear Research (ATOMKI)
Institut de Physique NucléaireTokyo Institute of Technology
Tohoku University
University of Tokyo
Rikkyo University
Kyoto University
Kurchatov Institute- 17 1

RIKEN Accel. Prog. Rep. 40 (2007)

Proton elastic scattering from light unstable nuclei at intermediate
energies
S. Terashima, H. Takeda, H. Otsu, K. Yoneda, T. Ichihara, T. Suda, H. Sakaguchi,∗1 J. Zenihiro, ∗2 Y. Iwao, ∗2
A. Yoshida, ∗2 T. Murakami, ∗2 Y. Matsuda, ∗3 T. Kobayashi,∗3 Y. Satou, ∗4 and K. Ozeki5[Nuclear structure, elastic scattering, unstable nuclei]
Proton elastic scattering at intermediate energies(200-400MeV) is a useful method of exploring matter density distributions in a nucleus. Due to the longmean free path in a nuclear medium, we can extract amore precise information of matter distribution. RIBF
will provide a wide variety of unstable nucleus beams
at intermediate energies. By measuring energies andscattering angles of recoil protons in inverse kinematics, we can distinguish between elastic and inelastic
scattering. For this purpose, we have been developinga detector system including incident beam detectors.1)
This year, we performed two experiments at the
Heavy-Ion Medical Accelerator in Chiba (HIMAC) facility in the National Institute of Radiological Science(NIRS). First, we performed a pilot experiment using
a 20 O beam with a thin solid hydrogen target (SHT)2)
to study matter distributions. The secondary beamof 20 O at 300 MeV/nucleon was produced by bombarding a 390MeV/nucleon 22 Ne beam on a 9 Be target. The intensity of 20 O was 105 particles/spill on
the SHT. The momentum bite of the incident beam
was ±1%, which was determined event-by-event using a 2 mm segmented fiber scintillator on the dispersive focal plane (F1)3) . The beam was achromaticallytransported to the SHT. The thickness of the SHT was
1 mm, which was covered with 9 µm aramid windows
on both sides. We have not yet established a methodof fabricating a SHT that is uniformly a 1 mm thick,the thickness of the SHT we used was not uniform.
The position and angle of the incident beam on the
SHT were determined using a set of beam line multiwire drift chambers (BDCs). The distance between the
BDCs was 1 m, the position resolution of each plane
was estimated to be about 200 µm[σ]. The energies
and angles of recoil protons from the SHT were measured using two sets of recoil detector arrays, which
consisted of recoil multiwire drift chambers (RDCs),
thin (2 mm) plastic scintillators, and NaI(Tl) scintillators. A recoil detector array covered a range between
67 and 84 degrees in the laboratory frame. Recoil protons were identified by the ∆E-E method using theplastic scintillator and the NaI(Tl) scintillators. Scattering angle was extracted from the angles of the incident beam and recoil protons.
∗1
∗2
∗3
∗4
∗5

Department of Applied Physics, Miyazaki university
Department of Physics, Kyoto university
Department of Physics, Tohoku university
Department of Physics, Tokyo Institute of Technology
Cyclotron and Radioisotope Center, Tohoku university

Fig. 1. Energy spectrum of scattered 20 O. The three arrows indicate 0+ (g.s.),2+ (1.64MeV), and 3− (5.61MeV)
4). Hatched area is the background from mainly aramid
window of the SHT estimated without SHT runs.

Figure 1 shows the preliminary energy spectrum of
scattered 20 O. The energy resolution obtained in thisstudy was 4-5 times worse than the design value. The
resolution was mainly limited by the angular resolution of recoil protons. Further analysis including theimprovement of tracking recoil protons and gain correction against position dependence of NaI(Tl) is now
in progress. In the next run, we are going to improveangular resolution by adding anode planes to RDCs,
and also to establish the method of fabricating a 1
mm-thick SHT to determine absolute cross sections.
Next, we developed low-energy recoil proton measurement. By measuring low-energy protons, we cancover an additional low-momentum transfer region.
Because we need to use a thinner target, we used a(CH2 )n target instead of the SHT. Low-energy recoil
protons were measured using three sets of silicon telescope arrays, which consisted of a 325 µm-thick Si strip
detector and two 3 mm-thick Si(Li) detectors. Recoil
protons were identified by the ∆E-E method using the
Si strip and Si(Li). The determination of the angular
distribution of differential cross sections is in progress
References
1) H. Takeda et al: RIKEN Accel. Prog. Rep. 39,
146(2006).
2) T. Ohnishi et al: RIKEN Accel. Prog. Rep. 38,
150(2005).
3) Y. Matsuda et al: RIKEN Accel. Prog. Rep. 40(2007).
4) R.B. Firestone, Table of Isotopes, 8th edn., (1996).

- 18 1

RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)
RIKEN
Accel.

β-decay study of C, N, O isotopes near neutron drip line
T. K. Onishi,∗1 H. Sakurai, H. Iwasaki,∗1 N. Aoi, T. Fukuchi,∗2 T. Fukui,∗3 A. Gelberg,∗4 Y. Ichikawa,∗1 E.
Ideguchi,∗5 T. Kishida, M. Liu,∗5 T. Nakao,∗1 M. Niikura,∗5 S. Nishimura, H. J. Ong,∗1 H. Otsu, S. Shimoura,∗5
T. Sumikama, D. Suzuki,∗1 H. Suzuki,∗1 M. K. Suzuki,∗1 N. Yamada, and Y. Zheng∗5[Nuclear structure, unstable nuclei, β decay]
One of the most interesting phenomena in nuclei farfrom the stability line is a variation in magic number.
The magic number N = 20 is broken in the region of“island of inversion”?) and the new magic number N =16 is suggested in oxygen isotopes?) . In this region, theproton-neutron ratio becomes imbalance and residualinteractions are modified from those in stable nuclei.
This causes the modification of the shell structure.
The nuclei with Z ≈ 8 provide an opportunity toinvestigate the effects of neutron excess on the p-sd
shell gap of the proton side. In particular, the β decayof the neutron-rich C and N isotopes is an excellent
probe. In these nuclei, valence neutrons occupy the sd
shell, while valence protons occupy the p shell. Therefore, intruder states are populated selectively throughan allowed transition because of the selectivity of theβ decay.
The present study was performed using the RIKEN
projectile fragment separator (RIPS) in the RIKEN
accelerator research facility. Radioactive ions were
produced by the projectile fragmentation of a 63
MeV/nucleon 40 Ar primary beam with an intensity of
500 pnA. The production target was Ta with a thickness of 333 mg/cm2 . Reaction fragments were collected
and analyzed using RIPS and transported to the final focal plane (F3) of RIPS. Several RIPS settings
were used depending on the nuclei of interest. The
beam was pulsed for measuring the half-lives of thenuclei. The durations of the beam-on and beam-off
periods were tuned to the nuclei of interest. However,if the secondary-beam intensity was lower than 1/τ ,the beam was not pulsed. In this situation, a β-decay
event can be related to a parent nucleus. Therefore,
the half-lives were measured using the difference intime between the beam and β decay.
The radioactive ions were implanted into a plastic
scintillator with a thickness of 5 mm at F3. This active
stopper enables us to count the number of implantedions.
The active stopper was also used as a β-ray detector.
This stopper had two photomultiplier tubes at bothends for rejecting a single photon noise for the efficient
detection of β rays.
∗1
∗2
∗3
∗4
∗5

Beam

Fig. 1. Experimental setup for observation of β-delayed γ
rays

The γ-ray detection system used consisted of two
clover-type Ge detectors and a CNS Ge array (GRAPE?)). Figure ?? shows a schematic view of this system.
The photopeak efficiency of this system was 4.3 % for
1 MeV γ rays. Each clover-type Ge detector was surrounded by an anti-Compton shield consisting of eight
BGO scintillators. Each BGO scintillator was 80 ×
250 × 25 mm3 . Rejecting β ray backgrounds of the Ge
detectors, each Ge detector had a plastic scintillator
at the front end. Plastic scintillators with a thicknessof 1 mm were used for the clover-type Ge detectors
and plastic scintillators with a thickness of 5 mm for
GRAPE.
We have carried out an experiment involving β-γ
measurements for C, N and O isotopes near a neutrondrip line. We observed β-delayed γ rays originatingfrom these nuclei. The analysis of the obtained data is
now in progress.
References
1) E. K. Warburton et al.: Phys. Rev. C 41 1147 (1990).
2) B. A. Brown and W. A. Richier: Phys. Rev. C 72
057301 (2005).
3) S. Shimoura: Nucl. Instr. and Meth. A 525 188 (2004).

Department of Physics, University of Tokyo
Department of Physics, Osaka University
Department of Physics, Kyoto University
Institut für Kernphysik dei Universität zu Köln
Center for Nuclear Study, Graduate School of Science, University of Tokyo- 19 1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

Reaction cross sections for 19 C, 20 C and 22 C on proton target
K. Tanaka, T. Yamaguchi,∗1 T. Suzuki,∗1 A. Ozawa,∗2 T. Aiba,∗3 N. Aoi, H. Baba, M. Fukuda,∗4
Y. Hashizume,∗2 K. Inafuku,∗5 N. Iwasa,∗5 T. Izumikawa,∗6 K. Kobayashi,∗1 M. Komuro,∗1 Y. Kondo,∗7
M. Kurokawa, T. Matsuyama,∗3 S. Michimasa,∗8 T. Nakabayashi,∗7 S. Nakajima,∗1 T. Ohtsubo,∗3
R. Shinoda,∗1 M. Shinohara,∗7 H. Suzuki,∗9 M. Takechi,∗4 E. Takeshita, S. Takeuchi, Y. Togano,∗10 K. Yamada,T. Yasuno,∗2 M. Yoshitake,∗1 T. Kubo, T. Nakamura,∗7 Y. Sakurai, and T. Motobayashi[]
Reaction cross section, unstable nuclei, 19 C, 20 C, 22 C

∗1

Department of Physics, Saitama University
Institute of Physics, University of Tsukuba∗3 Department of Physics, Niigata University∗4 Department of Physics, Osaka University∗5 Department of Physics, Tohoku University∗6 RI Center, Niigata University∗7 Department of Physics, Tokyo Institute of Technology∗8 Center of Nuclear Study, University of Tokyo∗9 Department of Physics, University of Tokyo∗10 Department of Physics, Rikkyo University
∗2

F3
F2

Liq. H2target

F4

TOF

∆E

NaI

Si

STQ
NaI array(DALI2)

Plastic

∆E

PPAC

Si
Plastic

PPAC

Beam
Plastic
scintillator

Reaction cross sections (σR ) for 19 C, 20 C and 22 C
in the vicinity of the neutron drip line have been measured on a proton target at around 40 MeV /nucleon.
22
C has 16 neutrons, which has been found to be anew ”magic number” for neutron-rich nuclei.1) In thatcase, the energies of the 1d3/2 and 2s1/2 orbitals arewell separated and the two-valence neutrons of 22 C are
expected to mainly occupy the 2s1/2 orbital. The separation energy of the two-valence neutrons is predicted
as 0.42 ± 0.94 MeV.2) These conditions lead to the formation of a large neutron halo; thus a large σR would
be observed. Because of low beam intensity, σR for
22
C has never previously been measured. σR for 19 C
and 20 C were measured at around 1000 MeV/nucleon
and their root-mean-square radii were deduced.3) If σR
for these nuclides are measured at lower energy, theirdensity distributions can be deduced from their energy
dependences.
The experiment was carried out at RIPS by thetransmission method. Figure 1 shows the experimental setup. An 40 Ar primary beam of 100-particle nA
was provided from the RIKEN ring cyclotron and bombarded a 333 mg/cm2 Ta production target. The nuclides in the secondary beams were identiﬁed event by
event using the time of ﬂight (TOF) between two plastic scintillators located at F2 and F3 focal planes, and∆E signal obtained from two silicon detectors (Si) of
100 µm thickness at F3. With all of the beam slits
fully opened, the intensities were 5 cps for 19 C, 0.5 cps
for 20 C and 0.003 cps for 22 C.
We modiﬁed the setup from the previous one4) bytaking into account the low-intensity beam. We applied liquid hydrogen5) (liq. H2 ) as a reaction target
installed at F3 to obtain a higher reaction rate thanthat using a carbon target which has often been usedin previous experiments. To achieve a high accuracy ofaround 1% for the target thickness over the whole area
(40 mmφ), we improved the liq. H2 system.5) We con-

E

TOF

Fig. 1. Setup for this experiment.

trolled the temperature to 15.9 ± 0.2 K which corresponds to 0.3% accuracy of the density, using a heatersystem5) during the measurement. The target thickness was measured by using a laser displacement sensor
to within 0.3 mm accuracy. The thickness of the target was estimated to be 205 mg/cm2 . The acceptanceafter the target was also improved by using a TOF
spectrometer6) of which the bore radius was twice ofthat of the previous setup.4)
Outgoing particles were identiﬁed by the TOF-∆EE method. The TOF between F3 and F4 was measured using two plastic scintillators, one immediately
before F3 and another at F4. The ∆E signal was obtained by using two Si detectors of 320 µm thickness
and 123 mmφ diameter installed at F4. The E signal
was obtained via a 5-inchφ NaI(Tl) detector.
As a preliminary result, σR for 19 C and 20 C wereobtained to be around 750 mb with a 10% error, andthat of 22 C was around 1100 mb with a 20 % error.
Although σR for 22 C has a large error, this result might
indicate that 22 C has a large halo structure.
References
1) A. Ozawa et al.: Phys. Rev. Lett. 84, 5493 (2000).
2) G. Audi et al.: Nucl. Phys. A 729, 337 (2003).
3) A. Ozawa et al.: Nucl. Phys. A 693, 32 (2001).
4) Y. Yamaguchi et al.: Phys. Rev. C 70, 054320 (2004).
5) K. Tanaka et al.: RIKEN Accel. Prog. Rep. 39, 151(2006), and references therein.
6) N. Aoi et al.: RIKEN Accel. Prog. Rep. 38, 176 (2005).

- 20 1

RIKEN Accel. Prog. Rep. 40 (2007)

Search for extremely neutron-rich systems 7H, 6H and 4n in the 2H + 8He collisions
E. Nikolskii,*1 A. Korsheninnikov, H. Otsu, H. Suzuki,*2 K. Yoneda, H. Baba, K. Yamada, Y. Kondo,*3 N. Aoi,
M. Golovkov,*4 A. Fomichev,*4 S. Krupko,*4 M. Kurokawa, E. Kuzmin,*5 I. Martel,*6 W. Mittig,*7 T. Motobayashi,
T. Nakamura,*3 M. Niikura,*8 S. Nishimura, A. Ogloblin,*5 P. Roussel-Chomaz,*7 A. Sanchez-Benitez,*6 Y. Satou,*3
S. Sidorchuk,*4 T. Suda, S. Takeuchi, K. Tanaka, G. Ter-Akopian,*4 Y. Togano,*9 M. Yamaguchi[Nuclear reactions, d(8He,3He)7H, d(8He,t)7He, unstable nuclei]
The existence of nuclear systems beyond the neutron
drip-line is one of the most fascinating problems of nuclear
physics. In our previous experiment we obtained
experimental evidence for the formation of the 7H state in
the p(8He,pp)7H reaction.1) An announcement of theobservation of stable tetra-neutron 4n was made by the
GANIL group.2) The first indication on possible existenceof the 6H resonance was obtained in the 7Li(7Li,8B)6H
reaction about 20 years ago.3) We carried out a newexperiment aimed to search for 7H, 6H and 4n using 8He
secondary beam and deuteron target.
The experiment was performed at the fragment separator
RIPS in RIKEN. The primary 18O beam with an energy of
100 A MeV and intensity of ~ 500 particle nA bombarded a
9Be target with a thickness of 12 mm. The secondary beam
was a cocktail of 8He and 12Be with the average energies of
42 A MeV and 71 A MeV, and intensities of 1.4 × 105 and2.6 × 105 pps, respectively. As a deuteron target, we used agas cryogenic target filled with deuterium gas at atemperature of 30 K and a pressure of 0.5 atm resulting in atarget thickness of 2.4 × 1020 deuterons/cm2. The beamenergy and parameters of the detection system were
optimized in complete Monte-Carlo simulations preceding
the experiment.
The experimental setup is shown in Fig.1. Two plastic
scintillators (at F2 and F3) were used to identify eachparticle of the secondary beam and to measure its energy bytime of flight. Trajectories of individual projectiles were
measured by a pair of MWPCs. Recoiling particles like d, t,
3
He, 4He and 6Li were detected by the RIKEN telescope ofsolid-state position-sensitive (strip) Si-detectors with anadditional dE-layer, which was an assembly of six thin (∼40 µ) Si counters. The beam passes through the central holein the telescope. This telescope allows to identify detectedparticles and to measure their energies and angles.
__________________________________________________________*1 On leave from Kurchatov Institute, Russia*2 Department of Physics, University of Tokyo*3 Department of Physics, Tokyo Institute of Technology*4 Joint Institute for Nuclear Research, Russia*5 Kurchatov Institute, Russia*6 Departamento de Fsica Aplicada, Universidad de Huelva, Spain*7 GANIL, Caen Cedex, France*8 Center for Nuclear Study, University of Tokyo

Projectile-like particles from breakup channels (e.g. tritonsand neutrons from the 7H → t + 4n decay) were measured
by a downstream detection system consisting of a dipole
magnet, a ΔE(1 cm) – E(6 cm) hodoscope of plastic
scintillators and a four-layer neutron hodoscope array. In
front of the neutron array a thin layer of plastic scintillators
was installed to reject events from charged particles.
Fig. 1. Setup of the experiment (the d(8He,3He)7H channel isshown).
dE-E HodoscopedE
RIKEN Detectors Beam
scintillators
Telescope

3 He

8 He

3H
n

Target D2
Dipole magnet

Neutron walls

MWPCs

Veto plastics

The following reaction channels are involved in theanalysis:- d(8He,3He)7H; d(8He,4He)6H;- d(8He,6Li)4n; d(8He,d4He)4n;- d(8He,t)7He- d(12Be,3He)11Li- d(12Be,6Li)8He; d(12Be,d4He)8He;- d(12Be,t) 11Be
The first experimental results showed a pronounced peakin the 7He excitation energy spectrum obtained in thed(8He,t)7He reaction. The peak is also clearly seen incoincidences with 6He in hodoscope and represents the 7He
ground state. This reaction will be a good reference tool tocontrol the experimental conditions. Detailed analysis of theexperimental data is in progress.
References
1) A.A. Korsheninnikov et al.: Phys. Rev. Lett. 90, 082501(2003).
2) F.M. Marques et al.: Phys. Rev. C 65, 044006 (2002).
3) D.V. Aleksandrov et al.: Yad. Fiz., 39, 513 (1984).

*9 Department of Physics, Rikkyo University                                    - 21 -

RIKEN Accel. Prog. Rep. 40 (2007)

Research on correlated two-nucleon system in 6Li and 6He nuclei
N.T. Khai *1,2, T. Suda, A. Yoshida, T. Ohnishi, H. Takeda, A. Ozawa*3, T. Suzuki*4, T. Sugawara*4, S. Nakajima*4,
K. Ogata*4, K. Kobayashi*4, S. Ishimoto, Y. Suzuki*4, Y. Takahashi, L.H. Khiem*1,2 and P.Q. Hung*2[One-nucleon exchange reaction, strong di-neutron correlation, solid-H2 target, backward scattering]
The 6Li and 6He nuclei are the typical six-nucleon
systems consisting of α-core and two loosely boundnucleons. 6He is the lightest halo nucleus showing
Borromean binding mechanism, which suggests a
strong di-neutron correlation for the formation of thetwo neutron halo (2n-halo) in this nucleus1-3). 6Li is astable nucleus whose cluster properties have been wellinvestigated through the (e, e’d) experiment, in which
the neutron-proton pair in the nucleus is found to havea similar wave function as that of a free deuteron4).
For the 6He nucleus, correlation between two
neutrons is still an open problem. Recently, theexperimental studies on 1n- and 2n-transfer reactionsin the 6He + p system, and 2n exchange in the 6He +4
He reaction have revealed the “di-neutron” and “cigar
like” configurations for the ground state structure2,3).
These predictions await further experimental
verification.
The (d, p) elastic scattering experiment showed anincrease in cross section at very backward scattering
angles in the center of mass (CM) system5). This
characteristic is mainly attributed to the nucleon
exchange mechanism. This suggests that if a similar
reaction can be observed for the 2n system in 6He, themeasurement will then provide a direct verification of
the existence of the correlated two-neutron structure inthis nucleus, because the exchange mechanism
requires a rather high relative momentum between
neutrons in the 2n system, typically 150 MeV/c.
We report on an experimental research in which wesearch for the 2n correlation in the 6He nucleus via the
one-nucleon exchange (ONE) reaction p(6He, 4He+n)din inverse kinematics using an incident 6He beam at anenergy of 70 AMeV delivered by the RIKEN
Accelerator Research Facility (RARF) and a newly
developed solid-H2 target (SHT)6). For reference, asimilar reaction was also measured for the 6Li + p
system. The reaction products, which are an α-particle,
a slow deuteron and a high-energy neutron for the 6He+ p system (and high-energy proton for the 6Li + p
system) have been measured in coincidence. The
detector systems were designed to determine thekinematical characteristics of the particles at backward
scattering angles in the CM system. The kinetic energy
and scattering angle of the deuteron were measured bya two-strip-array system consisting of semi circular
plastic strips. A thick plastic wall was used to measure
the neutron (and proton). In addition, a thin plastic
layer, called charge veto, was placed in front of thewall to identify charged particles. These detector
systems were placed on two sides of the reaction planeand covered the same range of angles from 5o to 30o in

the laboratory system. Located at the beam direction isthe detector for α-particle measurement, which
consists of three plastic layers coverings4o. A multiwire proportional chamber (MWPC) is in front of thisdetector for position measurement.
As shown in Fig. 1, the ONE reaction was identified
using energy correlation between α-particles andprotons for the 6Li + p system and between α-particles
and neutrons for the 6He + p system after particle
identificationinadditiontoslow-deuteron
identification. This allowed us to confirm theappearance of another competitive reaction.
Kinematically, it is consistent with the 1n-transfer
process (“two-step”), although the beam energies arequite high.
At present, detailed data analysis is under way, andtheoretical considerations are also being carried out toreach the conclusions from the physics viewpoint.
References
1) T. Kobayashi et al.: Phys. Rev. Lett. 60, 2599
(1988).
2) G. M. Ter-Akopian et al.: Physics Letters B 426,251 (1998).
3) Yu Oganessian et al.: Phys. Rev. Lett., Vol. 82, No.
5, 4996 (1999).
4) R. Ent et al.: Nuclear Physics A 578, 93 (1994).
5) K. Sekiguchi et al.: Phys. Rev. C, Vol. 65, 034003,
1 (2002).
6) S. Ishimoto et al.: Nucl. Instr. and Meth. A 480,
304 (2002).

Fig. 1. Identification of the ONE reaction channel
based on energy correlation between α-particles andprotons for 6Li + p system.
*1

Hanoi Institute of Physics and Electronics
Hanoi University of Science*3
Tsukuba University*4
Saitama University*2

1- 22 -

RIKEN Accel. Prog. Rep. 40 (2007)

Coulomb dissociation of 6 He
M. Shinohara,∗1 T. Nakamura,∗1 Y. Satou,∗1 Y. Kondo,∗1 T. Nannichi,∗1 T. Shimamura,∗1 Y. Nakayama,∗1
K. Yoneda, N. Aoi, H. Baba, Y. Ichikawa,∗2 K. Ieki,∗3 H. Kimura,∗2 T. Kobayashi,∗4 T. Machida,∗3
T. Motobayashi, H. Otsu, H. Sakurai, S. Shimoura,∗5 A. Shiraki,∗2 T. Sugimoto, S. Takeuchi, Y. Togano,∗3
K. Yamada, M. Yamaguchi, Y. Yauchi,∗3 and M. Ishihara
Nuclear Reaction: Pb(6 He,4 He2n), Coulomb dissociation, Invariant mass method
We have studied the Coulomb dissociation of the
two-neutron halo nucleus 6 He on a lead target at 69
MeV/nucleon. 6 He is a suitable nucleus for studying
the two-neutron halo and Borromean properties since
the interactions of the constituent subsystems, 4 He-n
and n-n, are well known. In addition, the ground stateof 6 He is rather well understood as having a hard core
(α particle) surrounded by the two valence neutrons
predominantly in the p3/2 orbital.
Recently, the electric dipole (E1) excitation strength
B(E1) of the two-neutron halo nucleus 11 Li has beenmeasured using the Coulomb dissociation.1) The observed B(E1) strength was well reproduced by a threebody model with a strong two-neutron correlation.
From this experiment, it was proved that the Coulomb
dissociation is a useful tool for investigating a twoneutron correlation and a three-body property. In thisexperiment, we have studied 6 He to further clarify how
the two-neutron correlation and three-body property
can be observed in the B(E1) distribution of this nucleus, whose structure and interactions between theconstituent particles are established. The previous
Coulomb dissociation data for 6 He reported from GSI2)
and MSU3) are inconsistent with each other. Furthermore, there may be a similar loss of eﬃciency at low
relative energies in these experiments as for 11 Li. Here,
we used an identical experimental setup and techniqueto exclude the cross-talk events in the two-neutron
detection, thereby enabling us to measure B(E1) at
low relative energies down to Erel =0 MeV. This study
would also provide a good test of the three-body calculations, which have been intensively performed recently. The comparison between the B(E1) distributions of 6 He and 11 Li would be useful to understandthe property of 11 Li, which has a more complicatedstructure than 6 He.
The experiment was performed at the RIKEN projectile fragment separator RIPS at the RIKEN Accelerator Research Facility. A secondary 6 He beam
was produced by the fragmentation reaction of a 100
MeV/nucleon primary 18 O beam incident on a Be target with a thickness of 1.48 g/cm2 . The secondary
beam was identiﬁed event-by-event using the time-of∗1
∗2
∗3
∗4
∗5

ﬂight (TOF) between a cyclotron RF timing and atiming from a 1-mm-thick plastic scintillator placed at
the second focal plane of RIPS. The 6 He particle bombarded a lead target with a thickness of 783 mg/cm2
and was broken up into 4 He and two neutrons. The
beam energy was 69 MeV/nucleon in the middle of thelead target. To measure the incident momentum vectorof the small Z at a high 6 He beam rate (40 kcps), we
used two multiwire drift chambers (MWDCs) placed
upstream of the lead target. The eﬃciency and position resolution were 95% and 130 µm, respectively.
The outgoing neutrons were detected by a fourlayered neutron hodoscope array (NEUT), which consists of 54 bars with a dimension of 6 cm × 6 cm ×
2.1 m. Upstream of NEUT, a thin layer of plastic scintillators (VETO) was installed to reject the charged
particle background. The momentum vectors of thetwo neutrons were reconstructed from the hit position
and TOF information.
The 4 He fragment produced in the breakup reaction
was bent by a large-gap dipole magnet and was traced
by two MWDCs located at the entrance and exit of
the magnet. The 4 He particles penetrated a hodoscope(HOD), which consists of seven plastic scintillator slatsof 1 cm thickness. Particle identiﬁcation of the charged
fragment was performed using the information of ∆E
and TOF obtained from HOD in combination with themagnetic rigidity information obtained by the tracking
with MWDCs. The momentum vector of 4 He was deduced by the combination of TOF and tracking information.
Data analysis is now in progress. By using the momentum vectors of 4 He and two neutrons, the relative
energy of 4 He+n+n will be reconstructed. By comparing the observed B(E1) distribution with theoretical
calculations, the behavior of the halo neutrons in 6 He,
such as the two-neutron correlation, will be discussed.
References
1) T. Nakamura et al.: Phys. Rev. Lett. 96, 252502 (2006).
2) T. Aumann et al.: Phys. Rev. C 59, 1252 (1999).
3) J. Wang et al.: Phys. Rev. C 65, 034306 (2002).

Department of Physics, Tokyo Institute of Technology
Department of Physics, University of Tokyo
Department of Physics, Rikkyo University
Department of Physics, Tohoku University
Center for Nuclear Study, University of Tokyo- 23 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Analyzing Power Measurement for the Proton
Elastic Scattering on 6 He at 71 A MeV
S. Sakaguchi,∗1 T. Uesaka,∗1 T. Wakui,∗6 N. Aoi, Y. Hashimoto,∗5 M. Ichikawa,∗7 Y. Ichikawa,∗2 K. Itoh,∗3
M. Itoh,∗6 H. Iwasaki,∗2 T. Kawabata,∗1 T. Kawahara,∗4 H. Kuboki,∗2 Y. Maeda,∗1 R. Matsuo,∗7 T. Nakao,∗2
H. Okamura,∗6 H. Sakai,∗2 N. Sakamoto, Y. Sasamoto,∗1 M. Sasano,∗2 Y. Satou,∗5 K. Sekiguchi, M. Shinohara,∗5
K. Suda,∗1 D. Suzuki,∗2 Y. Takahashi,∗2 A. Tamii,∗8 K. Yako,∗2 and M. Yamaguchi[nuclear structure, polarized target, unstable nuclei]
Spin-dependent interactions in unstable nuclei haverecently attracted much interest. One of the most powerful tools to study these interactions is direct reactions induced by polarized light ions. To investigate
the behavior of spin-orbit interaction in weakly boundsystems, we have measured the vector analyzing power
for the proton elastic scattering on 6 He at 71 A MeV.
A solid polarized proton target, which was speciallyconstructed for RI-beam experiments1,2) , was used.
The experiment was carried out at RIKEN Accelerator Research Facility with a 92 A MeV 12 C primary beam. A 71 A MeV 6 He beam was separated
by the RIKEN projectile fragment separator (RIPS)
with a purity of 95%. The typical beam intensity was
300 kcps. The 6 He beam bombarded a solid polarized
proton target with a size of 14 mmφ × 1 mmt . The
target material was a single crystal of naphthalene.
the average polarization of the target was 13.5%. For
the elimination of spurious asymmetry, polarization
direction was reversed three times by the 180-degree
NMR pulse method3) during the beam irradiation. A
schemetic view of the detecter setup is shown in Fig. 1.
Leading particles were detected by a multiwire drift
chamber (MWDC) and ∆E − E plastic scintillator hodoscopes with thicknesses of 5 and 100 mm. Recoiled
particles were detected by single-wire drift chambers
and CsI(Tl) scintillators placed on the left and rightsides of the beam line.
6
He particles were identified by ∆E − E correlation
measured by the plastic scintillator hodoscopes. Protons were identified by the correlation of the energy
measured by CsI scintillators and the scattering angle determined by SWDCs. p~+6 He elastic scattering
events were selected by requiring a kinematical consistency for protons and identified 6 He particles. Analyzing power was deduced from the spin-dependent
asymmetry of scattering and target polarization.
Preliminary results are shown as closed circles inFig. 2. Previously measured differential cross sec∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Department of Physics, Saitama University
Department of Physics, Toho University
Department of Physics, Tokyo Institute of Technology
Cyclotron and Radioisotope Center, Tohoku University
Department of Physics, Tohoku University
Research Center for Nuclear Physics, Osaka University- 24 -.&   (*  ,     & & 5 -$&%'&   ()(*&+  "!$#, &  )) 2
4 &  5 -$& 
6'7 899;:< = > :?
, &  )* 2  3&  ) (*  ) & & , "!/#0#  1                          Fig. 1. Experimental setup. A secondary 6 He beam fromRIPS bombarded the solid polarized proton target.
Leading and recoil particles were detected.

tion data are also plotted as open circles4) and open
squares5) . The solid and dashed lines show the resultsof the calculation by phenomenological optical model
analysis and a prediction using a microscopic model6) ,respectively. Further analysis is now in progress.

Fig. 2. Differential cross section and analyzing power areplotted. Details are in the text.

References
1) T. Wakui et al., Nucl. Instrum. and Methods. A 550(2005) 521.
2) T. Uesaka et al., Nucl. Instrum. and Methods. A 526(2004) 186.
3) T. Kawahara et al., CNS Ann. Rep. 2005 (2006).
4) M. Hatano et al., Eur. Phys. J. A 25 (2005) 255.
5) A. Korsheninnikov et al., Nucl. Phys. A 617 (1997) 45.
6) K. Amos, private communication.

1

RIKEN Accel. Prog. Rep. 40 (2007)

Elastic Scattering of 8 B on Pb, Liquid H2 and Liquid He Targets
S. Bishop, T. Motobayashi, N. Aoi, H. Baba, T. Gomi, Y. Ichikawa, ∗1 N. Imai, ∗1 N. Iwasa, ∗2 H. Iwasaki, ∗1 S.
Kawai, ∗3 Y. Kondo, ∗4 T. Nakamura, ∗4 T. Nakao, ∗1 S. Nishimura, T. Ohnishi, T. K. Onishi, ∗1 H. J. Ong, ∗1
S. Ota, ∗4,5 A. Perera, S. Shimoura, ∗4 T. Sumikama, D. Suzuki,∗1 H. Suzuki, ∗1 M. K. Suzuki,∗1 S. Takeuchi,
M. Tamaki, ∗4 K. Tanaka, Y. Togano,∗3 and Y. Yanagisawa
The 7 Be(p,γ)8 B reaction, occurring in the solar
PPIII reaction chain, has been under intense experimental and theoretical study for many years now. The
subsequent β-decay of 8 B gives rise to the solar neutrino flux and the famous “solar neutrino problem”,
which has now been resolved?) .
Studies of this reaction employing the Coulomb dissociation (CD) method have been performed in thepast, but some questions still remain regarding thecontribution of the target nuclear field to the 8 B dissociation cross section. Sophisticated continuum discretized coupled channel approaches are now used toanalyze such 8 B CD reaction studies, but the validityof the nuclear models employed (folding models employing NN interactions, for example) have never beenchecked against 8 B elastic scattering data because suchdata has not existed until now.
In an effort to resolve this issue for 8 B CD, as well
as future experiments employing the CD technique, wehave performed a 8 B dissociation experiment utilizing
targets comprising 57 mg/cm2 Pb, 61.5 mg/cm2 liquid
H2 and 116 mg/cm2 liquid He. The experiment was
performed using the RIKEN RIPS facility?) . Further
experimental details can be found elsewhere?) . 8 B elastic scattering data were acquired concurrently, for all
three targets. The resulting elastic angular distributions have been fit within the framework of a WoodsSaxon (WS) optical potential approach and these fits
have been tested against the data by way of a GEANT
simulation of the experiment. Figure ?? shows, in theform of laboratory frame dσ/dθ plots, our 8 B elastic
data (black circles) for the three targets along withthe resulting optical model predictions of the GEANT
simulation (histograms). Table ?? summarizes the WS
parameters obtained from our fits; note that the spinorbit potential depth was held fixed at 6.2 MeV. Theseelastic data represent the first time 8 B elastic scattering has been measured and the first time WS optical model parameters have been obtained for 8 B elastic scattering. For the upcoming dissociation/breakup
data analysis, these data will provide the basis for testing and constraining the nuclear models we will employ; any nuclear model constructed, in addition to reproducing the dissociation/breakup data, should also
∗1
∗2
∗3
∗4
∗4
∗5

Table 1. Optical Parameter Results
H2
He
Pb

VR
28.00
24.95
65.80
55.81
50.00

Wv
24.30
13.32
30.32
34.32
57.90

aR
0.750
0.750
0.801
0.801
0.800

aso
0.750
0.750
–
–
–

av
0.320
0.335
0.545
0.567
0.800

RR
1.20
1.17
1.345
1.245
1.067

Rso
1.01
1.01
–
–
–

be able to reproduce these elastic distributions. Moreover, because the dissociation channel arises within thefolding models from the imaginary component of thepotential, successful reproduction of these elastic distributions will self-consistently constrain the dissociation channel within the nuclear model employed.

Fig. 1. Laboratory frame elastic angular distributions,dσ/dθ, of 8 B. Top left: 8 B + p. Top right: 8 B + 4 He.
Bottom: 8 B + Pb. Circles are the data, and the histograms are the GEANT simulation results.

References

Department of Physics, University of Tokyo
Department of Physics, Tohoku University
Department of Physics, Rikkyo University
Department of Physics, Tokyo Institute of Technology
Center for Nuclear Study, University of Tokyo
Department of Physics, Kyoto University

1) Q. R. Ahmad et al.: Phys. Rev. Lett. 87, 071301,(2001).
2) T. Kubo et al.: Nucl. Inst. Meth. B 70, 309, (1992).
3) S. Bishop et al.: RIKEN Accel. Prog. Rep. 39, 44,(2006).

- 25 1

Rv
1.16
1.32
1.56
1.57
1.067

RIKEN Accel. Prog. Rep. 40 (2007)

14

Be(p, n)14 B(1+ ; 1.28 MeV) reaction at 70 MeV/nucleon

Y. Satou,∗1 T. Nakamura,∗1 N. Fukuda, T. Sugimoto, Y. Kondo,∗1 N. Matsui,∗1 Y. Hashimoto,∗1
T. Nakabayashi,∗1 T. Okumura,∗1 M. Shinohara,∗1 T. Motobayashi, Y. Yanagisawa, N. Aoi, S. Takeuchi,
T. Gomi, Y. Togano,∗2 S. Kawai,∗2 H. Sakurai, H. J. Ong,∗3 T. K. Onishi,∗3 S. Shimoura,∗4 M. Tamaki,∗4
T. Kobayashi,∗5 H. Otsu, Y. Matsuda,∗5 N. Endo,∗5 M. Kitayama,∗5 and M. Ishihara[](p, n) reaction, 14 Be
The (p, n) reaction has been one of the major probes
of a nuclear structure; it can provide essentially thesame information as the nuclear beta decay without
limitation due to an available energy window, and thephase space factor that scales as E05 for allowed transitions with E0 À 1 MeV (E0 is the decay energy). In recent years, the (p, n) reaction has been successfully applied to the spectroscopic studies of unstable nuclei1,2) .
In this study, we have investigated the Gamow-Tellertransition from 14 Beg.s. leading to the 1+ state at 1.28
MeV in 14 B. It is of interest to see if consistent interpretation of data can be made between the (p, n) andbeta-decay studies3,4) . Because the 1+ state is locatedabove the neutron decay threshold of 0.97 MeV in 14 B,
we made use of the invariant mass method in inverse
kinematics.
The experiment was performed at the RIKEN accelerator research facility. A 14 Be beam with an energy of
70 MeV/nucleon was produced using RIPS from a 100
MeV/nucleon 18 O primary beam with an intensity of
400 pnA. The production target was a 6-mm-thick Be
plate; the aluminum energy degrader had a thicknessof 4.63 mm. The typical beam intensity at F3 was 7
kcps for a momentum setting of ∆P/P = ±2%. The
layout of the experimental setup is the same as thatof the 19 C(p, p0 ) measurement5) , except for the thickness of the secondary cryogenic hydrogen target (229mg/cm3 ).
Figure 1 shows a two-dimensional particle identiﬁcation diagram of beamlike charged particles measured
in coincidence with forward emitted neutrons. Among
various beryllium isotopes with Z=4, we can clearlyobserve loci due to boron isotopes with Z=5. Such isotopes cannot be produced via ordinary fragmentation
processes; instead charge exchange processes must be
involved.
By selecting 13 B with a gate as shown in the ﬁgure,
we can construct an invariant mass event-by-event forthe decaying 13 B + n system. Figure 2 shows the invariant mass (relative energy) spectrum thus obtained.
A prominent peak at Erel ≈ 0.3 MeV corresponds to
the known 1+ state4) . The forward peak nature in the
angular distribution of 14 B (not shown) supports the
∗1
∗2
∗3
∗4
∗5

Department of Physics, Tokyo Institute of Technology
Department of Physics, Rikkyo University
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
Department of Physics, Tohoku University

1+ assignment for this state. Strength at Erel ≈1 MeV
may correspond to the known 2− 1.86 MeV state. A
comparison of the observed diﬀerential cross sections
with DWBA calculations using shell model wave functions is in progress to clarify structures related to 14 Be
and 14 B.

<

$

#<
Fig. 1. Two-dimensional particle identiﬁcation diagram of
beamlike charged particles.

Fig. 2. Relative energy spectrum of 13 B + n system.

References
1) T. Teranishi et al.: Phys. Lett. B 407, 110 (1997).
2) S. Takeuchi et al.: Phys. Lett. B 515, 255 (2001).
3) M. D. Belbot et al.: Phys. Rev. C 56, 3038 (1997).
4) N. Aoi et al.: Phys. Rev. C 66, 014301 (2002).
5) Y. Satou et al.: RIKEN Accel. Prog. Rep. 39, 51 (2006).

- 26 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Invariant-mass spectroscopy of 13 Be and 14 Be
Y. Kondo,∗1 T. Nakamura,∗1 Y. Satou,∗1 T. Sugimoto, N. Matsui,∗1 Y. Hashimoto,∗1 T. Okumura,∗1
T. Nakabayashi,∗1 M. Shinohara,∗1 N. Aoi, N. Endo,∗2 N. Fukuda, T. Gomi, M. Ishihara, S. Kawai,∗3
M. Kitayama,∗2 T. Kobayashi,∗2 Y. Matsuda,∗2 T. Motobayashi, H. J. Ong,∗4 T. K. Onishi,∗4 H. Otsu,
H. Sakurai, S. Shimoura,∗5 S. Takeuchi, M. Tamaki,∗5 Y. Togano,∗3 and Y. Yanagisawa£¤
NUCLEAR REACTIONS: 14 Be+p, Invariant mass method
Unbound states in the neutron-rich nuclei 13 Be andBe have been studied by applying the invariant mass
method to the inelastic scattering and one-neutron
knockout reaction of 14 Be on a proton target. Shellmelting at the magic number N = 8 in the neutronrich beryllium isotopes has been established by several
experimental studies on 11 Be and 12 Be, while the shellevolution in the N > 8 region is still unknown. Recently, the first 2+ state in 14 Be was observed in theunbound region by the inelastic scattering on a carbon
target, and a lower excitation energy and smaller deformation than those for 12 Be were found.1) The mechanism of lowering of the 2+ energy and the smaller deformation of 14 Be have not yet been well understood.
For 13 Be, no decisive measurements for the groundstate have been reported so far. In the present study,
we aim at clarifying the shell evolution by studying thenuclear structure not only in the drip-line nucleus 14 Be
but also in the unbound nucleus 13 Be. The structural
information of 13 Be is also important in understanding the structure of 14 Be as a Borromean three-bodysystem (12 Be+n+n).
In the present study, the inelastic scattering and oneneutron knockout reaction of 14 Be were measured by
the same setup. For the inelastic scattering, the collectivity of 14 Be has been investigated. By comparing thedeformation measured on the proton target with thaton the carbon target, the collectivities of the neutronsand protons in 14 Be can be deduced independently. For
the one-neutron knockout reaction, the low-lying resonant states in 13 Be are populated and its level structure was studied. The spectroscopic factor of 14 Be canalso be deduced.
The experiment was performed using the RIPS beamline. A radioactive 14 Be beam was produced byprojectile fragmentation of a primary 18 O beam at
100 MeV/nucleon and separated by RIPS. The secondary 14 Be beam at 69 MeV/nucleon bombarded aliquid hydrogen target, which then broke up into 12 Be
and neutron(s). The outgoing 12 Be and neutron(s)were detected and analyzed in order to obtain their
momentum vectors that are used to reconstruct theinvariant mass of unbound states in 13 Be and 14 Be.
14

∗1
∗2
∗3
∗4
∗5

Department of Physics, Tokyo Tech
Department of Physics, Tohoku University
Department of Physics, Rikkyo University
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo

Details of the detector setup are described in the previous report.2)
Figure 1(a) presents the decay energy spectrum forthe 12 Be+n+n system in the inelastic channel obtained
from the Mn = 2 (neutron multiplicity) events by removing the neutron crosstalk events. A narrow peakat around 0.3 MeV, corresponding to the first excited
2+ state in 14 Be, has been observed. Figure 1(b)shows the spectrum for the 12 Be+n system in the oneneutron knockout channel obtained from the Mn = 1
events after subtracting the inelastic contribution. The
peak observed at around 0.5 MeV may correspondto the ground state in 13 Be and the peak at 2 MeV
corresponds to the d-wave resonance, as reported inprevious experiments.3–5) Further analysis is now inprogress.

Fig. 1. Decay energy spectra for the 12 Be+2n (a) and12
Be+n (b) systems obtained from the inelastic scattering and one-neutron knockout reaction of 14 Be, respectively.

References
1) T. Sugimoto: PhD thesis (2006).
2) Y. Kondo et al.: RIKEN Accel. Prog. Rep. 39, 45(2006).
3) A. A. Korsheninnikov et al.: Phys. Lett. B 343, 53(1995).
4) A. V. Belozyorov et al.: Nucl. Phys. A 636, 419 (1998).
5) J. L. Lecouey: Few-Body Syst. 34, 21 (2004).

- 27 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Resonance levels in 14 O near the 13 N+p threshold
T. Teranishi,∗1 S. Kubono,∗2 H. Yamaguchi,∗2 J.J. He,∗2 A. Saito,∗2 H. Fujikawa,∗2 G. Amadio,∗2 M. Niikura,∗2
S. Shimoura,∗2 Y. Wakabayashi,∗2 S. Nishimura, M. Nishimura, J.Y. Moon,∗3 C.S. Lee,∗3 A. Odahara,∗4
D. Sohler,∗5 L.H. Khiem,∗6 Z.H. Li,∗7 G. Lian,∗7 and W.P. Liu∗7[Nuclear structure, unstable nuclei]
A set of T = 1 triplets in A = 14 nuclei (14 C, 14 N,
and 14 O) is a good example of isobaric analog multiplets that has been studied for many years. However,knowledge of the 14 O levels is still poor compared withthat of 14 C and 14 N.1) The J π value of the 6.8-MeV
level is unknown. The 0− level, which is supposed
to be several hundreds of keV above the 1− level at
5.2 MeV, is yet to be identiﬁed. The Ex , Γ, and J πvalues for the low-lying 14 O levels should be further
investigated to determine their correspondence to theanalog levels and to study the wave functions. We haveinvestigated resonance levels in 14 O populated in the
13
N+p elastic scattering, which was measured in inverse kinematics with a secondary beam of 13 N and a
proton target. The secondary 13 N beam was produced
by CRIB2) of CNS in the RIKEN facility. We utilized
the thick target method3) to eﬃciently measure the excitation functions of 13 N+p elastic scattering withoutchanging the 13 N beam energy. The proton target wasa sheet of (CH2 )n with a thickness of 8.3 mg/cm2 anda diameter of 3 cm. The secondary 13 N beam energy
before the target was 48.6 MeV with a width of 1.6
MeV (FWHM). The 13 N intensity was approximately
2 × 105 particles/sec, which was 98% of the total secondary beam intensity. Recoil protons emitted fromthe proton target were detected using a silicon detector∆E-E telescope at the laboratory angle of θLAB = 0◦ .
Figure 1 shows the 13 N+p excitation function measured using the silicon detector telescope. The spectrum covers ECM = 0.4–3.3 MeV (Ex = 5.0–7.9 MeV).
Four resonance-like signatures are seen at ECM ∼ 0.5,
1.6, 2.1, and 3.1 MeV in the spectrum. They may be
attributed to the known 14 O levels at Ex = 5.2, 6.3,
6.8, and 7.7 MeV with J π = 1− , 3− , (unknown), and
2+ , respectively. To determine J π for the 6.8-MeV
level, the experimental spectrum was ﬁtted with an Rmatrix-based calculation4) . The result for the J π = 2−case is shown by the solid line in Fig. 1 and is consistent with the experimental spectrum. Therefore, weassigned J π = 2− to the 6.8-MeV level.
The 0− level, which has never been observed intransfer reactions, is expected to be observed as an
∗1
∗2
∗3
∗4
∗5
∗6
∗7

Department of Physics, Kyushu University
Center for Nuclear Study, the University of Tokyo
Chung-Ang University, Republic of Korea
Department of Physics, Osaka University
ATOMKI, Hungary
Institute of Physics and Electronics, Vietnam
China Institute of Atomic Energy, P.R. China

Fig. 1. Experimental excitation function for the 13 N+p
scattering measured at around θLAB = 0◦ . The solidline shows the result of the ﬁtting calculation. The
dashed line represents the result when J π for the 6.8MeV level is changed to 3− . The dotted line shows theresult without a contribution of the 0− level at Ex ∼ 5.7
MeV. The gap at ECM ∼ 0.8 MeV is due to the deadlayers of the ∆E-E telescope.

s-wave resonance in the 13 N+p spectrum. Therefore,
we included the 0− level in the ﬁtting. The Ex and Γ
values for the 0− level were preliminarily determined
to be 5.72 MeV and 0.4 MeV, respectively. This result
is roughly consistent with the calculated Ex and Γ values using the s-wave resonance phase shift in a proton
scattering model with a Woods-Saxon potential5) .
The widths of the 1− , 3− , and 2− levels were preliminarily determined to be 42, 42, and 90 keV, respectively, by the ﬁtting. These widths are comparable
to the single-particle widths estimated by the WoodsSaxon potential model, where the resonance proton orbital was assumed to be 2s1/2 for the 1− level and 1d5/2
for the 3− and 2− levels.
References
1) F. Ajzenberg-Selove: Nucl. Phys. A523, 1 (1991).
2) Y. Yanagisawa et al.: Nucl. Instrum. and Methods
A539, 74 (2005).
3) K.P. Artemov et al.: Sov. J. Nucl. Phys. 52, 408 (1990).
4) T. Teranishi et al.: Phys. Lett. B556, 27 (2003).
5) R. Sherr: Phys. Rev. C73, 037310 (2006), and references
therein.

- 28 1

RIKEN Accel. Prog. Rep. 40 (2007)

Proton resonance scattering of 7 Be
H. Yamaguchi,∗1 Y. Wakabayashi,∗1 G. Amadio,∗1 H. Fujikawa,∗1 S. Kubono,∗1 A. Saito∗2 J.J. He∗3 T.
Terahishi∗4 Y.K. Kwon∗5 S. Nishimura Y. Togano∗6 N. Iwasa∗7 K. Inafuku∗7 M. Niikura∗1 and L.H. Khiem∗8[Nuclear structure, nuclear astrophysics]

∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Center for Nuclear Study, Graduate School of Science, University of Tokyo
Department of Physics, Graduate School of Science, University of Tokyo
School of Physics, The University of Edinburgh
Department of Physics, Kyushu University
Department of Physics, Chung-Ang University
Department of Physics, Rikkyo University
Department of Physics, Tohoku University
Institute of Physics and Electronics, Vietnam Academy of
Science and Technology

160

Cross section (mb/sr)

S17 (E) is regarded as an important factor for thesolar neutrino problem in the standard solar model.
Although great eﬀorts were spent by many experimental groups1), the experimental precision remains stillaround 10 %, because of the small reaction cross section. It is claimed that the determination of the S17
below 300 keV with a precision better than 5 % may
make a major contribution to our knowledge for thesolar model2) .
Besides the small cross section of the reaction, theexistence of excited levels of 8 B can also be a problem on the determination of S17 . However, we do nothave suﬃcient knowledge of the nuclear structure of8
B. Only the lowest two excited states at 0.77 MeV
and 2.32 MeV were clearly observed in past experiments. Another excited state around 3.5 MeV wasobserved as an unexpectedly wide resonance, and thiswas explained as a low-lying 2s state3,4) . This kind ofwide states may aﬀect the measurement of 7 Be(p,γ)8 B
cross section even at very low energies (much less than
1 MeV). Thus we intended to measure the resonancesof 8 B, to evidently observe the 3.5 MeV resonance reported in the past measurements, and also to explore
the totally unknown region E >3.5 MeV, where we
may ﬁnd new resonances.
The measurement was performed at CRIB8,9) . The
primary beam used in this measurement was 7 Li3+ of
8.76 MeV/nucleon, with the beam current of about 100
particle nA. The RI-beam production target was purehydrogen gas, which was enclosed in an 8 cm-long cell,at 760 Torr and room temperature (∼ 300 K). The 7 Be
beam energy used in this measurement was 53.8 MeV,of which the corresponding center-of-mass energy is 6.7
MeV. The intensity of the produced 7 Be4+ beam was
3 × 105 particles per second at the resonance scatteringtarget. We used a standard experimental method forthe proton elastic resonance scattering (thick target
method), well-established at CRIB10) .
Excitation functions were obtained by calculating
the cross section from the numbers of the proton

140
120
100
80
60
40
20
0
-20
0

1

2

3

4

5

6

7

Ecm (MeV)

Fig. 1. Preliminary analysis result on the proton excitation
function of 7 Be measured at 0 degrees. The excitationenergy of 8 B, Eex equals to Ecm +0.1375 MeV.

events, Figure 1 shows an excitation function at zero
degree. The analysis is still going on, and this specturm should be regarded as a preliminary one. The
cross section agree well with the past measurements3,4)
in the energy region around the known 2.2 MeV resonance. The 3.5 MeV resonance, which was reported asa wide resonance, is not clearly seen in this spectrum,
possibly due to its large width. Some part of the continuum in the spectrum is considered as contributions
from inelastic scatterings and three-body decays of 8 B.
In a near future, we will make a more detailed analysis
including these eﬀects.
We are grateful to the accelerator staﬀ in RIKEN
and CNS for their help. This work was supported by
the Grant-in-Aid for Young Scientists (B) (Grant No.
17740135) of JSPS.
References
1) C. Angulo, et al.: Nucl. Phys. A 656 (1999) 3.
2) E. Adelberger, et al.: Rev. of Mod. Phys. 70 (1998)
1265.
3) V. Gol’dberg et al.: JETP Lett. 67, (1998) 1013.
4) G. Rogachev et al.: Phys. Rev. C 64 (2001) 061601(R).
5) A. van Hees and P. Glaudemans: Z. Phys. A 314(1983) 323.
6) A. van Hees and P. Glaudemans: Z. Phys. A 315(1984) 223.
7) F. Barker, and A. Mukhamedzhanov: Nucl. Phys. A
673 (2000) 526.
8) S. Kubono et al.: Eur. Phys. J. A 13 217 (2002).
9) Y. Yanagisawa et al.: Nucl. Instrum. Methods Phys.
Res., Sect. A 539 74 (2005).
10) T. Teranishi et al.: Phys. Lett. B 556 27 (2003).

- 29 1

RIKEN Accel. Prog. Rep. 40 (2007)

In-beam γ-ray measurement using 20 Ne + 96 Zr reaction
Y. Zheng,∗1 E. Ideguchi,∗1 S. Ota,∗1 M. Niikura,∗1 M. Liu,∗1 H. Baba,∗2 D. Suzuki,∗3 S. Shimoura,∗1 and H.
Yamaguchi∗1£¤
NUCLEAR REACTION: 20 Ne + 96 Zr at Elab =130 MeV; in-beam γ-ray measurement
Nuclei in the A∼110, Z∼50 mass region are of greatinterest for providing clear images of a nuclear structure. Single-particle motions are expected to predominate the excitation scheme in these nuclei due to theZ = 50 shell closure. However, other excitation mechanisms such as collective rotations exhibiting smoothband terminations, where terminating configurations
involve proton particle-hole excitations across the Z =50 gap1) , and magnetic rotations (M1 bands)2) are alsopresented to generate angular momentum in this mass
region. Recent theoretical calculations have been used
to predict that a region of shape minima at deformations with 2:1 axis ratios (or larger) exists at a high angular momentum in A∼110 nuclei3) . A superdeformed(SD) band was observed in 108 Cd4) and it was suggested to be among the most deformed structures everobserved. Its deformation corresponds to an axis ratio larger than 2:1 as predicted by the calculations. In
this region, 109 In is also expected to have M1 band,SD band, and smooth band terminations at high-spinstates. To find such a nuclear structure, we have investigated high-spin states in 109 In. In this report,
in-beam γ-ray measurement of A ∼ 110 nuclei using
the 20 Ne + 96 Zr reaction is presented.
The experiment was performed at RIKEN accelerator research facility. High-spin states of A∼110 nuclei
were populated using the 20 Ne + 96 Zr reaction at 6.5
MeV/A beam energy, which was chosen so that thecross section to produce 109 In becomes predominant.
The 20 Ne beam was provided by AVF cyclotron. The
96
Zr target had a thickness of 1 mg/cm2 . To check the
production cross sections of evaporation residues, thebeam current was measured using a Faraday cup during the measurement. γ rays from fusion-evaporation
residues were detected by a coaxial Ge detector placedat an angle of 90◦ relative to the beam direction.
The production cross sections of evaporation
residues as a function of beam energies for the 20 Ne+ 96 Zr reaction were estimated using the statisticalmodel code CASCADE5) . In the measured energy region, nuclei in the evaporation channels of 1p5n-1p7n(108−110 In) and 1α4n-1α6n (106−108 Cd) will be mainly
produced. Figure 1 shows the γ-ray energy spectrum
obtained in this work. γ-Ray assignments were performed using previously reported peak energies. In
the spectrum, the most intense γ peaks originate from
∗1
∗2
∗3

Center for Nuclear Study, Graduate School of Science, University of Tokyo
RIKEN (The Institute of Physical and Chemical Research)
Department of Physics, University of Tokyo( x 10 4)
107

109

7

Cd
In 204 110In

90

Single gamma spectrum

169 210243 109In
336
110

Sn

280

3

109

108

In 511

106

20

Cd
Cd

96

Ne + Zr

633 107Cd
362 109In
109
391
640 In 106Cd
108
492 Cd110
In 861556
107
108
674 Cd809
Cd110
798
Sn
876
985

400

800

109

In

1428

1200

1600

Fig. 1. γ-ray energy spectrum at 6.5 MeV/A.

108−110

In and 106−108 Cd as predicted by CASCADE
calculation.
The production cross sections of these nuclei havebeen extracted in the 6.5 MeV/A data from the γ-ray
peak intensities, beam current and the detection efficiency of the Ge detector. The results are shown in
Table 1. Although there is a discrepancy in the production cross sections between the experimental result
and the CASCADE calculation, the relative yields ofthe nuclei are consistent with those of the calculation(see Table 1) and 109 In has the largest production crosssection (∼129 mb) among the residual nuclei obtainedwith the measured energy.
Further analysis of the experimental data is inprogress.
Table 1. Production cross sections
Nuclei(channel)
109
In (1p6n)107
Cd (2p7n)
106
Cd (2p8n)
110
In (1p5n)
108
Cd (2p6n)
108
In (1p7n)

Production cross section (mb)theoretical
215.3
192.7
152.3
107.8
72.9
63.9

experimental
129(3)
111(3)
90(8)
73(3)
69(3)
37(2)

References
1) I. Ragnarsson et al.: Phys. Rev. Lett. 74, 3935 (1995).
2) A. Gadea et al.: Phys. Rev. C 55, R1 (1997).
3) R. R. Chasman: Phys. Rev. C 64, 024311 (2001).
4) R. M. Clark et al.: Phys. Rev. Lett. 87, 202502 (2001).
5) F. Fühlhofer: Nucl. Phys. A 280, 267 (1977).

- 30 1

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)

Study of high-spin states in 49−51 Ti by secondary fusion reaction
M. Niikura,∗1 E. Ideguchi,∗1 N. Aoi, H. Baba, T. Fukuchi,∗2 Y. Ichikawa,∗3 H. Iwasaki,∗3 T. Kubo,
M. Kurokawa, M. Liu,∗1 S. Michimasa,∗1 T. Ohnishi, T. K. Onishi,∗3 S. Ota,∗1 S. Shimoura,∗1 H. Suzuki,∗3
D. Suzuki,∗3 Y. Wakabayashi,∗1 K. Yoshida, and Y. Zheng,∗1

NUCLEAR REACTION, 9 Be(46 Ar, xn)55−x Ti, unstable nuclei, fusion reaction
In-beam γ-ray spectroscopy by fusion-evaporation
reactions is one of the most efficient methods ofstudying nuclear structure at high spin, because large
amounts of angular momentum can be brought into
the system. However, nuclei produced via fusionevaporation reactions using stable isotope beams arelimited, in many cases, to the proton-rich side relative
to the β-stability line. To investigate the high-spinstates of neutron-rich nuclei by the fusion-evaporation
reaction, it is necessary to use neutron-rich secondary
beams. In the doubly magic nuclei 48 Ca, the onset
of deformed collective states due to the presence of deformed shell gaps in Z = 20, 22 and N = 28 is expected
at high spin. In this report, the in-beam γ-ray measurements in 49−51 Ti by secondary fusion reaction, i.e.,
46
Ar +9 Be, are described.
The experiment was performed at the RIPS beamline in RIKEN1) . A low-energy secondary 46 Ar beam
was produced by projectile fragmentation and its energy was lowered using aluminum degraders placed at
the first and second focal planes of RIPS. The secondary beam bombarded a 10-µm-thick 9 Be target
placed at the third focal plane to induce secondary fusion reactions, i.e., 9 Be 46 Ar, xn 55−x Ti. Details on
the production of a secondary beam are reported in
ref.2) .
Gamma rays emitted from the high-spin statesof evaporation residues were detected by the CNS
Gamma-Ray detector Array with Position and Energy
sensitivity (GRAPE)3) together with two clover andone coaxial germanium detectors. These γ-ray detectors were placed around the secondary target to cover
the angular range between 30◦ and 120◦ relative to thebeam direction.
We have obtained the γ-ray spectra of 49 Ti, 50 Ti and51
Ti, wherein we reconfirmed known cascade γ transitions from the spin (19/2)−, (11+ ) and (13/2,17/2)
states in 49 Ti, 49 Ti and 49 Ti4–6) , respectively.
To identify cascade γ transitions, we performed a γγ coincidence analysis. Figure 1 shows the total projected γ-γ spectrum gated by known γ rays of 51 Ti.
We reconfirmed coincidence relations between known
γ rays and found new γ transitions at 761 and 678 keV.
The left panel of Fig. 2 shows the relative γ-ray
yield as a function of detected γ-ray multiplicities.
∗1
∗2
∗3

Center for Nuclear Study, University of Tokyo
Department of Physics, Osaka University
Department of Physics, University of Tokyo

Fig. 1. Total projected γ-γ coincidence spectrum gated by
known γ rays of 51 Ti.

Fig. 2. Relative γ ray intensity normalized to that of lowest transition at 1437 keV as function of detected γray multiplicity (left) and proposed level scheme of 51 Ti(right).

The γ-ray yields are normalized to the intensity of
the lowest transition at 1437 keV. Because the newly
observed γ rays at 761 and 678 keV are enhanced in
the high-multiplicity spectrum, these γ-rays are placed
above the known 3644 keV state (see the right panelof Fig. 2).
Further analysis to assign spins for the newly observed states using angular distribution is now inprogress.
References
1) T. Kubo et al.: Nucl. Instrum. and Methods B 461, 309(1992).
2) E. Ideguchi. et al.: in this report.
3) S. Shimoura: Nucl. Instrum. and Methods A 525, 188(2004).
4) M. Behar et al.: Nucl. Phys. A366, 61 (1981).
5) B. Gass et al.: Phys. Rev. Lett. 40, 1313 (1978).
6) S. E. Arnell et al.: Phys. Scr. 6, 222 (1972).

- 31 1

RIKEN Accel. Prog. Rep. 40 (2007)

Low-energy 46 Ar beam for secondary reaction
E. Ideguchi,∗1 M. Niikura,∗1 N. Aoi, H. Baba, T. Fukuchi,∗2 Y. Ichikawa,∗3 H. Iwasaki,∗3 T. Kubo,
M. Kurokawa, M. Liu,∗1 S. Michimasa,∗1 T. Ohnishi, T.K. Onishi,∗3 S. Ota,∗1 S. Shimoura,∗1 H. Suzuki,∗3
D. Suzuki,∗3 Y. Wakabayashi,∗1 K. Yoshida, and Y. Zheng∗1
NUCLEAR REACTION, 46 Ar+9 Be, unstable nuclei, fusion-evaporation reaction
In 48 Ca and 50 Ti, a highly deformed band structureis expected to be present at high-spin states as in thecase of 40 Ca1) due to the deformed shell gaps of Z=20,
22 and N=28. To investigate high-spin states in these
nuclei, we employ a fusion-evaporation reaction withan RI beam, 46 Ar+9 Be. In order to realize such a
low-energy nuclear reaction, we have developed a lowenergy 46 Ar beam.
An experiment was performed at the RIPS2) facility
in RIKEN. A secondary 46 Ar beam was produced by
the fragmentation reaction of a 48 Ca beam impinging
on a 9 Be target of 1.625 mm thickness. The primary48
Ca beam of 63 MeV/nucleon with a typical intensity of 100 pnA was provided by the RIKEN Ring Cyclotron. The energy of the 46 Ar beam right after the
primary target was ∼40 MeV/nucleon. An aluminum
curved degrader with a mean thickness of 0.6 mm
placed at the momentum-dispersive focal plane (F1)
was used to achieve a clear isotope separation and tolower the energy of the fragment to ∼23 MeV/nucleon.
The energy of the 46 Ar beam was further lowered by aplastic scintillator of 0.1 mm thickness and an Al rotatable degrader of 0.3 mm thickness at the achromatic focal plane (F2). It was adjusted to be ∼4 MeV/nucleon
at the center of the secondary 9 Be target of 0.01 mm
thickness (Fig. 1). After passing through the rotatable
degrader, the 46 Ar beam had a broad charge state distribution and the dominant charge state was estimatedto be 16+ . The typical intensity of the 46 Ar beam at
F2 was 1.5×106 pps.

Fig. 1. Energy spectrum of the 46 Ar beam at secondary
target.

Particle identification of the beam was carried out
by the TOF-∆E method. TOF and ∆E data were
∗1
∗2
∗3

Center for Nuclear Study, the University of Tokyo
Department of Physics, Osaka University
Department of Physics, University of Tokyoobtained from the timing of the plastic scintillator relative to the RF signal of the cyclotron and Si detector
at F2, respectively. The purity of the beam was measured to be 98%, and the main contaminant was 44 Cl.
The 46 Ar beam was transported to the third focal plane (F3) and irradiated on the secondary target
to make a fusion-evaporation reaction, 46 Ar + 9 Be.
The typical intensity of the 46 Ar beam at F3 was
1.2×106 pps. Two PPAC counters3) were placed upstream of the secondary target in order to profile theimage and the incident angle of the beam on the target. The beam spot sizes (σ) at the target were foundto be 13.1 mm and 11.8 mm, respectively, in horizontal
and vertical directions as shown in Fig. 2. The energyof the beam was determined from the TOF between
the timing of plastic at F2 and that of PPAC at F3,
event by event.

Fig. 2. Beam spot at secondary target.

After the target, another PPAC counter was placed
to detect reaction products so as to deduce their energy and angle. A TOF spectrometer4) was also placed
after the third PPAC, and reaction product and the46
Ar beam passing through the target was transported
to the final focal plane (F4). At F4, another PPAC
counter was placed to measure the position and timing of the transported particles. The TOF between F3
and F4 was used to purify the event associated withthe fusion-evaporation reaction.
Data analysis is still in progress.
References
1) E. Ideguchi et al.: Phys. Rev. Lett. 87, 222501 (2001).
2) T. Kubo et al.: Nucl. Instrum. and Methods B 461,
309 (1992).
3) H. Kumagai et al.: Nucl. Instrum. and Methods A 470,
562 (2001).
4) N. Aoi et al.: RIKEN Accel. Prog. Rep. 38, 176(2005).

- 32 1

RIKEN Accel. Prog. Rep. 40 (2007)

Development of secondary beams produced by fusion reactions for
β-decay measurement
Y. Wakabayashi,∗1 H. Yamaguchi,∗1 S. Hayakawa,∗1 G. Amadio,∗1 S. Nishimura, A. Kim,∗2 D. N. Binh,∗3
Y. Gono,∗1 and S. Kubono∗1[β-decay, unstable nuclei beam]

∗1
∗2
∗3

ing the 12 C + 40 Ar reaction, the primary beam intensity was 10 enA considering the limit of the count rateof the Ge detector. The bombarding energy was 4.1
MeV/u after installing the Havar foil. Gamma rays
emitted from 45−48 Ti, 47−49 V and 49 Cr could be identified as shown Fig. 1. Sharp peaks such as 1333 keVwere derived from the background γ-rays.
11000
48

V
46

7000

Ti

48

V

Cr

V

48

46

600

47

Ti

847 keV1333 keV

3000

49

49

Ti

e+e - 511 keV

1173 keVCount / ch

For the rapid proton capture process (rp-process)in X-ray burst and the core-collapse stage of supernova, proton-rich pf -shell nuclei far from stability play
important roles1) . Studies of the β and electron capture decays of these proton-rich pf -shell nuclei are ofgreat astrophysical interest. These decays involvedin the charged-current processes are predominated by
the Fermi and Gamow-Teller (GT) transitions. Information on the GT transitions can be derived directlyfrom β-decay measurements. However, the GT transition strengths (B(GT)’s) of these proton-rich nuclei
far from stability were measured for only a few lowlying states with large uncertainties due to the small
production cross sections and short half lives. To determine the accurate B(GT), it is important to know
the feeding ratio and half-life of the β-decay accurately.
In this study, the final purpose of the experimentis to measure i) the total half-life of the β-decay withan accuracy better than 10 %, ii) the decay branchingratios to the ground state (Fermi transition) and GT
states accurately.
Test experiments of different primary beam conditions were performed using CRIB2,3) .
A selfsupporting 12 C primary target of 0.4 mg/cm2 was installed at F0. This 12 C target was bombarded by primary beams of 40 Ar11+ of 4.5 MeV/u and 40 Ca11+ of
5.6 MeV/u to produce secondary beams. A parallelplate avalanche counter (PPAC) was set at a dispersive
focal plane (F1) for beam monitoring. Another PPAC
and a Si detector of 1.5 mm thickness were installed forparticle identification (PI) at an achromatic focal plane(F2). For PI, a monolithic Si detector4) was placed behind the PPAC at F1. This Si detector consists of 1.5µm-thick and 500-µm-thick layers that are used as ∆E
and E counters, respectively. A Ge detector was set
at 260 mm from the 12 C primary target for measuring
γ rays emitted from the fusion reaction products. A
2.2-µm-thick Havar foil was installed at the entranceof the F0 chamber to enclose helium gas and used asa gas-filled recoil isotope separator (GARIS). Heliumgas was supplied from the entrance of the F0 chamberto the exit of the F2 chamber.
Figure 1 shows the single spectrum measured by the
Ge detector placed at F0. In the measurement us-

800

1000

V
48

Ti

49

V

47

Ti

45

Ti

46

Ti

1500
49

V

46

47

Ti + Ti

1400

1600

1800

0.92 keV / ch

Fig. 1. Single spectrum of Ge detector placed at F0.

The proper gas pressure for the GARIS condition
was searched using a primary beam with a beam energy of around 4 MeV and a Z ≈ 20 region. The half
widths of the momentum distribution become narrower
from 2.7 to 1.6 % when the helium gas pressure wasincreased from 6 to 20 Torr. However, PPAC could
not be operated over 20 Torr and the proper He gaspressure was not found.
PI using the ∆E-E counter of the monolithic Si detector was performed with a helium gas pressure of 8
Torr. To confirm that the fusion products reached the∆E-E counter, the coincidence of the ∆E counter andGe detector was measured.
Further analysis is now in progress.
References
1) K. Langanke and G. Martinez-Pinedo: Rev. Mod. Phys.
75, 819 (2003).
2) S. Kubono et al.: Eur. Phys. J. A 13, 217 (2002).
3) Y. Yanagisawa et al.: Nucl. Instrum. Methods Phys.
Res. A 539, 73 (2005).
4) A. Musumarra et al.: Nucl. Instrum. Methods Phys.
Res. B 409, 414 (1998).

Center for Nuclear Study, University of Tokyo
Department of Physics, Ewha Woman University
Institute of Physics and Electronic, Vietnam Academy of
Science and Technology- 33 1

RIKEN Accel. Prog. Rep. 40 (2007)

Production of low-energy polarized radioactive beams using CRIB
K. Shimada,∗1 D. Nagae,∗1 K. Asahi, T. Arai,∗1 M. Takemura,∗1 T. Inoue,∗1 K. Takase,∗1 S. Kagami,∗1
N. Hatakeyama,∗1 Y. Kobayashi, H. Ueno, A. Yoshimi, D. Kameda, T. Nagatomo, T. Sugimoto, S. Kubono, ∗2
H. Yamaguchi,∗2 Y. Wakabayashi,∗2 G. Amadio,∗2 S. Hayakawa,∗2 J. Murata,∗3 and H. Kawamura∗3

∗1
∗2
∗3

Department of Physics, Tokyo Institute of Technology
Center for Nuclear Study, Tokyo University
Department of Physics, Rikkyo University

β counter
RF coil

M1
Dipole1

F0: Target

Primary beam

Q1

Secondarybeam

Q2
MagnetF1
F2

Dipole 2
M3 Q3

β raysstopper

Wien filter

ExB
Q4 Q5

Q6 Q7

F3

Fig. 1. Schematic view of CRIB and β-NMR apparatus.

count (arb. unit)

A beam of radioactive nuclei (RNB) with their spinspolarized has been applied to various fields. Studies of
RNBs are performed not only in nuclear physics suchas nuclear moments and β decays1), but also in condensed matter physics including magnetism in metals and insulators, impurities and electronic dynamics
in semiconductors2), and superconductivity3) . RNBs
may even be an exclusive tool for investigating surfaces, layers and nanosized structures, if the energy
and spatial distribution (spot size) of spin-polarized
RNBs are controlled with sufficient precision.
One of the most appropriate methods of obtaining such RNBs may be RNB production via inversekinematics reactions. The spin polarization of a recoil
product in the low-energy nucleon-transfer reaction depends on both the recoil angle and kinetic energy of the
product nuclei2,4) . In inverse-kinematics, the distribution in the recoil angle in normal kinematics is forward
focusing, thus facilitating a very efficient collection of
RNB particles. However, the small but finite widths of
the angular and energy distributions of RNB preserve
the memory of the recoil angle and energy. Thus, byselecting a certain region of angles and energies of RNB
emission, the RNB may be spin-polarized. In addition,
in inverse-kinematics, we could use an in-flight separator that provides the separation of the RNB particles
from other species and facilitates the formation of awell-focused RNB.
We are developing a method of producing a spinpolarized 17 N or 18 N beam via inverse-kinematics reactions using a low-energy in-flight separator for RNBs,
called CRIB5) . CRIB consists of a double achromatic
system and Wien filter, and its configuration is shownin Fig. 1. A primary beam of 18 O7+ at 7.0 MeV/u andwith an intensity of 240 pnA bombarded a thin Be
target of 2.8 mg/cm2 , which was installed in a target
chamber at F0. The 17 N (18 N) beam was produced by
nucleon transfer (exchange), and its momentum was
1.83 GeV/c (1.86 GeV/c). By limiting the emission
angle to −(0.6◦ –2.8◦ ) and the momentum dispersion
to 1.83 GeV/c –1.85 GeV/c, the yield of the 17 N (18 N)
beam was typically 105 cps (104 cps). In this scheme,
however, it is hard to exclude other impurities mixed
in the beam. In order to check the ratio of impurities
and the possibilities of excluding them in the off-line
analysis, we stopped the beam particles and observed
the time spectrum of β emitted in their β decay. The

400
300
200
100

17

N

18

0

0

N

2

4

constant background68
10 12 14time (sec)Fig. 2. Time spectrum of detected β rays. The solid curve
represents the best fit to the data with the theoretical
function consisting of two exponentials plus a constantbackground. The dashed curves show the decay curvesof 17 N (T1/2 = 4.173 s ) and 18 N (T1/2 = 624 ms ), andconstant background fitting, respectively.

time spectrum for the 17 N beam is shown in Fig. 2.
The ratios of the β rays emitted from 17 N and 18 N are
67 % and 10 %, respectively.
The measurement of spin polarization by β-NMR isbeing prepared. After the production of spin-polarized
17
N or 18 N beams is established, we plan to use themfor the study of structures formed by N impurities ina diamond crystal6) .
References
1) H. Ueno et al.: Phys. Lett. B 615, 186–192 (2005).
2) T. Izumikawa et al.: Hyp. Int. 136/137, 599 (2001).
3) J. P. Araújo et al.: Nucl. Instrum. Methods Phys. Res.
B 148, 807 (1999).
4) M. Tanaka et al.: Nucl. Phys. A 263, 1 (1976).
5) Y. Yanagisawa et al.: Nucl. Instrum. Methods Phys.
Res. A 539, 74–83 (2005)
6) T. Arai et al.: RIKEN Accel. Prog. Rep. 39, 90 (2006).

- 34 -

1

RIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)
RIKEN

Electron scattering from unstable nuclei by the SCRIT method (III)†T. Suda, T. Emoto, Y. Furukawa1 , K. Ishii2 , S. Ito, K. Kurita2 , A. Kuwajima1 , T. Tamae1 , M. Wakasugi, S.
Wang and Y. Yano[electron scattering, RI, SCRIT]
Electron scattering is one of the most precise probes
for studying the internal structure of atomic nuclei,
and will surely play an essential role in the structurestudies of radioactive isotopes (RI) when an electronRI (eRI) scattering experiment becomes possible.
We have proposed a novel scheme for an eRI scattering experiment, SCRIT (Self-Confining RI Target).
On the basis of numerical simulations, a sufficiently high luminosity for elastic electron scattering,
1027 /cm2 /s, is expected for 107 /s ion injection with a
500-mA electron beam current1) . Since 2004, we havestarted feasibility studies by installing a SCRIT prototype at an existing electron storage ring, KSR, in
Kyoto University.
This year, we have installed a set of pure CsI
calorimeters for the scattered electron detection. The
detector consists of seven optically isolated pure CsI
crystals, and each crystal has a hexagonal cross section with a diameter of 80 mm and a length of 200
mm. The detector was placed at a scattering angle of
30 deg. and the SCRIT region was viewed through adrift chamber.
The response of each crystal was measured using cosmic rays. In addition, we installed a W wire in the
SCRIT chamber, whose thickness was 50 µm. The wire
position is remotely controllable, and it can be placed
very close to the circulating electron beam. The elastically scattered electrons from the wire were clearlyobserved, and the response function of the CsI detector for a 100-MeV electron was determined.
Figure 1 shows the electron energy spectrum measured with continuous injection of Cs ion from an external ion source. The storaged electron beam current
was kept at about 50 mA.
In the figure, a bump at about 100 MeV is observed. A GEANT simulation, in which the prototype geometry is completely taken into account, showsthat the low-energy region of the spectrum is due tobackground, which originates from halo electrons that
produce the electro-magnetic showers in the materials
in the SCRIT region. The energy dependence is well
reproduced by this background simulation. The energy spectrum obtained after background subtraction
is shown together in Fig.1, in which a broad peak at
about E = 90 MeV is clearly observed. The position
and width of the peak shown in the upper figure of
Fig.1 are both consistent with the response to the 100∗1∗2

Tohoku University
Rikkyo University

MeV scattered electrons from the W-wire. Since thepeak was not observed before starting the Cs ion injection, one can conclude that the elastically scatteredelectrons are from the injected Cs ions. The achieved
luminosity is estimated to be 2 x 1025 /cm2 /s.
Measurements with and without Cs ion injection,
which is periodically repeated at a frequency of 10 Hz,
however, do not show any difference in the number ofelastic events. This observation suggests that the elastic events may not come from the externally injected
Cs ions but from Cs ions probably evaporated fromthe surface of materials such as electrodes. Since we
injected so many Cs ions in our previous measurement,
many Cs ions may have adhered on the surface of suchmaterials. We will soon start further measurements
to confirm this with efforts to reduce the contribution
from evaporated Cs ions.
References
1) M. Wakasugi, T. Suda and Y. Yano: Nucl. Instrum.
Methods A532, 216 (2004).

RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 1. Electron energy spectrum. The overlaid figure
shows the energy spectrum after background subtraction. The dashed line in the figure is an extrapolationfrom the low energy spectrum, which is consistent with
the GEANT simulation. A peak centering at about 90
MeV corresponds to elastic scattering events from Cs
ions.

- 35 1

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)

Electron scattering oﬀ wire targets in SCRIT
Y. Furukawa,∗1 A. Kuwajima,∗1 T. Tamae,∗1 T. Emoto, K. Ishii,∗2 S. Ito, K. Kurita,∗2 A. Noda,∗3 T. Shirai,∗3
T. Suda, H. Tongu,∗3 M. Wakasugi, S. Wang, and Y. Yano[electron scattering, wire targets, SCRIT]
We are testing a prototype of the SCRIT (SelfConﬁning RI Target) at KSR (Kaken Storage Ring)of Kyoto University. In the SCRIT, targets ions are
conﬁned transversely by a negative potential produced
an electron beam, and longitudinally using an electrostatic mirror potential generated by electrodes. The
longitudinal length of the trapped ions is 12 cm, andtheir density is very low. As the number of scatteredelectrons from the SCRIT is very few, it is hard to
calibrate electron detection counters and a luminosity
monitor using those electrons. We installed a wire target system for such calibrations. It is also used for
improvement of the spacial resolution of a drift chamber.
Two 105 mm-long wires of thick tungsten with 50µm in diameter, and of thin carbon with about 10µm in diameter, have been stretched on the holder asshown in Fig. 1. The lower wire is of tungsten andthe upper one is of carbon. The distance of the two
wires is 12 mm. The wires can be inserted by remotecontrol onto the storaged electron beam through thespace between two electrodes at 6.6 cm upstream fromthe center of the SCRIT.

An energy spectrum of scattered electrons oﬀ thetungsten wire measured using a pure CsI calorimeteris shown in Fig. 2 by a solid line. The calorimeterconsists of seven optically-separated crystals of pureCsI with a hexagon cross section of 80 mmφ and 200
mm long. It was set at a scattering angle of 30◦ .
The incident electron energy is 121 MeV. The energy
was calibrated by comparing the cosmic-ray spectrumwith a GEANT simulation. There is a large energy
loss of scattered electrons in the material between thewire and the CsI calorimeter, such as plastic scintillators for trigger and plastic covers for protection of thedrift chamber. The material also broadens the peak ofelastically-scattered electrons. The energy spectrum
calculated using the GEANT simulation is also shownin Fig.2 by a broken line. Overall agreement between
the calculation and measurement is seen except thehighest energy part of the spectrum; the source of thisdiscrepancy is under investigation. The material between the target and the CsI calorimeters should be
removed as much as for obtaining a more accurate
spectrum.

90
80

Counts

70
60
50
40
30
20
10
0
Fig. 1. Wire targets. The lower is 50 µm tungsten, and theupper is 10 µm carbon.
∗1
∗2
∗3

Tohoku University
Rikkyo University
Kyoto University

0

20

40

60 80 100 120 140
Energy (MeV)

Fig. 2. Energy spectrum of the scattered electrons oﬀ thetungsten wire measured with a CsI calorimeter. A solidline shows the measured spectrum, and a broken line
represents a GEANT simulation.

- 36 1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

Laser spectroscopy of 7,10 Be+ in an online ion trap at SLOWRI
T. Nakamura, M. Wada, K. Okada,∗1 A. Takamine,∗2 Y. Ishida, Y. Yamazaki, T. Kambara, Y. Kanai,
T. M. Kojima, Y. Nakai, N. Oshima, ∗3 A. Yoshida, T. Kubo, S. Ohtani,∗4 K. Noda,∗5 I. Katayama,∗6 V.
Lioubimov,∗7 H. Wollnik,∗8 V. Varentsov∗9 and H. A. Schuessler∗7[]
online ion trap, laser spectroscopy, 10 Be+ , 7 Be+ , isotope shift
600hνobs = ϵa − ϵb = hν

∞

µ
µ
−
hν ∞ +
κ,
Mn
Mn

(1)

where µ is the reduced electron mass, Mn is the nuclear
mass, ν ∞ is the transition frequency of the inﬁnite
heavy nucleus, κ = Ka −Kb 〈is the diﬀerential〉 mass po∑Nlarization parameter, K =p·pj /me is thei<j imass polarization parameter of an N -electron atomic
system, pk is the momentum of the k-th electron, andme is the electron mass. In Eq. (1), the second termis the normal mass shift (NMS) and the third term isthe speciﬁc mass shift (SMS).
The absolute transition frequencies of the 2s 2S1/2 →2p 2P3/2 transition of 7 Be+ , 9 Be+ and 10 Be+ ions were
determined to be 957 347.37(12) GHz, 957 396.515(14)GHz and 957 414.839(35) GHz, respectively. By ﬁtting with Eq. (1), we determined the transition energy of inﬁnitely heavy Be, ν ∞ = 957 569.55(28) GHz,and the diﬀerential mass polarization parameter κ/h =−1 884.5(46) THz. Figure 1 illustrates these results.
Details of these experiments are described in Ref.2) .
We plan to proceed to isotope shift measurements
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

Department of Physics, Sophia University
Graduate School of Art and Science, University of Tokyo
National Institute of Advanced Industrial Science and Technology (AIST)
Institute for Laser Science, University of Electro-Comm.
National Institute for Radiological Science
High Energy Accelerator Research Organization (KEK)
Department of Physics, Texas A&M University, USA
II. Physikalisches Institute, Giessen University, Germany
Kholopin Radium Institute, Russia

ν - 957 000 [GHz]An online ion trap for precision laser spectroscopy
has been developed at the prototype slow radioactive
ion beam facility (SLOWRI) of RIKEN. Energetic radioactive beryllium isotope ions (7 Be+ and 10 Be+ ) provided by the projectile fragment separator RIPS are
decelerated and cooled in a gas catcher cell, and thethermal ions are extracted and collected in a linear rf
trap by an rf carpet ion guide.1)
Laser spectroscopy of the 2s 2S1/2 → 2p 2P3/2 transition for trapped 7,9,10 Be+ ions had been performed andtheir absolute transition frequencies were measured
with accuracies of ∼ 10−8 . From these frequencies,
we determined the absolute isotope shifts of beryllium
isotopes for the ﬁrst time.2)
Neglecting, for the time being, the small eﬀect fromthe nuclear charge radii, the isotope shift is given by
the observable transition frequency νobs between thetwo energy levels ϵa and ϵb as,

ν

∞

NMS

(µ/me ) ν∞

500

11

(ν )
400

SMS

10

ν ν9
7

deviation [GHz]

300
0.4 0

2

4
-5
µ/M [10 ]

ν
8

6
9

n

νliterature

0.2
0
0

2

4
5
10 µ/Mn

68

Fig. 1. Transition frequencies ν A are plotted as a functionof µ/Mn to indicate the two contributions — the NMS
and the SMS — to the isotope shifts. The deviations
from the ﬁts are also indicated at the bottom. The
old value for stable 9 Be+ 3) which is an extrapolated
value from the measurement at high magnetic ﬁeld is
9indicated as νliterature.

of even higher accuracies, such as 10−10 , by utilizing
the laser-laser double-resonance spectroscopy method
3)and the frequency comb4) clockwork frequency calibration. Such measurements will enable us to determine the charge radii of the beryllium isotopes whenmore accurate theoretical atomic structure calculations are also available.
A combination of the charge radii values with theisotope shift measurements and the magnetization distribution with the hyperﬁne anomaly measurements
would allow us to perform complete measurements ofthe diﬀerent distributions of neutrons and protons ina nucleus of the beryllium isotopes obtainable with apurely electromagnetic probe.
References
1) A. Takamine et al.: Rev. Sci. Instrum. 76, 103503(2004).
2) T. Nakamura et al.: Phys. Rev. A 74, 052503 (2006).
3) J. J. Bollinger et al.: Rhys. Rev. A 31, 2711 (1985).
4) T. Udem et al.: Nature (London) 416, 233 (2002).

- 37 1

RIKEN Accel. Prog. Rep. 40 (2007)

Pumping 229mTh by hollow-cathode discharge [IV]Hiromitsu Haba, Mitsuo Hara,*1 Takashi T. Inamura, Yoshitaka Kasamatsu,*2 Hidetoshi Kikunaga, Toshiaki Mitsugashira,*1
Takashi Nakanishi,*3 Tsutomu Ohtsuki,*4 Atsushi Shinohara,*5 Yoshimitsu Suzuki,*1 Koichi Takamiya,*6 Shin Watanabe,*1
Akihiko Yokoyama,*3 and Hideyuki Yuki *4[Nuclear structure, NEET by electric discharge, alpha decay]
This is the 4th report of our series of endeavors to searchfor evidence of an extremely low-lying isomer in 229Th, theenergy of which is believed to be 3.5 ± 1.0 eV.1) Since it
was first postulated by Kroger and Reich in 1976,2) thisexotic isomer has long been sought but has yet not been
confirmed. Here, we summarize what we have learned forthe last three years and what we are going to do.
In 2002, Inamura and his international collaborators
proposed a novel method of populating the “3.5-eV isomer”
229m
Th by hollow-cathode electric discharge as follows:3)
The atomic states are excited as is the case of optical
spectroscopy and then NEET (nuclear excitation by electrontransition or inverse internal conversion)4) through a certain
excited atomic state is expected to populate 229mTh,
although its exact excitation energy is not known. Thismethod was coupled with α measurement to detect the
population of 229mTh after switching off the electric
discharge by fully making use of the high S/N ratio in αmeasurement.5,6) Schematic excitation and deexcitation
processes of 229mTh are shown in Fig. 1. First, assuming its
half-life to be 14 ± 3 hours according to a preliminary
measurement by means of the 230Th (γ,n) reaction,7) westarted measuring α decay from 229mTh after the electric
discharge. Our first measurement did not confirm thepreliminary half-life and instead suggested that it isdefinitely shorter than 20 minutes.8) Recently, we conducted
rapid chemistry of the 229Th sample,9) which was subjectedto the discharge in the hollow-cathode tube for about 20
minutes, to have high-resolution α spectra (17-keV fwhm
for 241Am 5486-keV alphas) as a function of time. The
whole process was repeated four times and eachmeasurement was started about 5 minutes after thedischarge. However, no trace of delayed α components wasfound. Not only did that confirm our previous
measurements,8,10) but it also indicated that the half-lifeshould be less than 2 minutes; otherwise, we would havedetected delayed α components.
Now, we have to deal with a small α branching from theisomer that would be some five hundred times smaller thanthe branching expected at the beginning. 5, 6) (See Fig. 1.) To
start the measurement in the hollow-cathode tube
immediately after switching off the discharge with a better*1

Oarai Branch, Institute for Materials Research, Tohoku University
Advanced Science Research Center, JAEA, Tokai
Graduate School of Natural Science and Technology, Kanazawa
University*4
Laboratory of Nuclear Science, Tohoku University*5
Graduate School of Science, Osaka University*6
Research Reactor Institute, Kyoto University

energy resolution we have removed an Al-coated Mylar
window (see Ref. 10) and set a shutter to shield the intenselight coming from the hollow cathode during the discharge.
We have tested the whole setup and confirmed that we canstart the measurement within 30 seconds after the discharge.
The next and probably last measurement with this setup will
be carried out shortly.

T1m2

m

T1g2

g

α

α
atomictransitions

nucleartransitions
229
225

Ra

Th

Fig. 1. Schematic excitation and deexcitation processes of229m
Th during hollow-cathode electric discharge. Nuclear
ground and isomeric states are denoted by g and m,
respectively; probable intermediate states produced bycoupling atomic and nuclear states are denoted by two shortlines.
References

1) R. G. Helmer and C. W. Reich: Phys. Rev. C 49, 1845 (1994).
2) L. A. Kroger and C. W. Reich: Nucl. Phys. A259, 29 (1976).
3) T. T. Inamura et al.: Annual Report 2002, Heavy Ion Laboratory,
Warsaw University, p. 42; Czech. J. Phys. 53, B349 (2003).
4) M. Morita: Prog. Theor. Phys. 49, 1574 (1973).
5) H. Haba et al.: RIKEN Accel. Prog. Rep. 37, 263 (2004).
6) T. T. Inamura, T. Mitsugashira, and the Oarai Collaboration:
Hyp. Interact. 162, 115 (2005).
7) T. Mitsugashira et al.: J. Radioanal. and Nucl. Chem. 255, 63(2003).
8) S. Enomoto et al.: RIKEN Accel. Prog. Rep. 38, 249 (2005).
9) H. Kikunaga et al.: Radiochim. Acta 93, 507 (2005).
10) H. Haba et al.: RIKEN Accel. Prog. Rep. 39, 227 (2006).

*2*3- 38 -

RIKEN Accel. Prog. Rep. 40 (2007)

Dependence on ortho-para D2 ratio of ddµ formation rate inmuon-catalyzed fusion
K. Ishida, H. Imao,∗1 T. Matsuzaki, Y. Matsuda, N. Kawamura,∗2 A. Toyoda,∗2 and K. Nagamine∗2,∗3,∗4[muon, nuclear fusion, deuterium]
In the muon-catalyzed fusion cycle, the formationof a muonic molecule is usually the slowest of all theprocesses; thus, increasing its rate is the key to improving µCF efficiency. In a previous report1) , we showed
the result of a preliminary measurement of dtµ molecular formation rate at the RIKEN-RAL Muon Facility, in which we compared the rate in an ortho-D2 /T2
mixture with that in normal-D2 /T2 . The result was
not conclusive because of the possibility of fast orthopara equilibration in the presence of radioactive tritium. Thus, we are studying a simpler system, namely,
ddµ formation in ortho D2 and normal D2 . The information on ddµ formation will be useful for elucidating
dtµ formation since both processes occur as a result ofa resonant molecular formation mechanism.
The experiment was performed2) at the TRIUMF
M9B muon channel in Canada. The timing spectrumof fusion neutron emissions relative to muon injection has two exponentially decaying components. The
faster and larger one is due to resonant ddµ formationfrom dµ in the upper hyperfine state (F = 3/2) andthe slower one is due to nonresonant formation fromdµ in F = 1/2. The resonant ddµ formation rate isdefined as the rate that a dµ (F = 3/2) reacts witha surrounding D2 to form a ddµ molecule and can be
determined from the amplitude of the faster decaying
component. The measured rates in solid and liquid D2
are shown in Fig. 1. We observed a clear decrease in
the rate for ortho D2 compared with that for normal
D2 , which was opposite of the theoretical predictions
based on the isolated gas model.
For the gas case, the timing spectrum showed a small
deviation from the two-exponential structure. Thus,
instead of fitting the spectrum with two components,
the total yields of fusion neutrons were compared inFig. 2. The ortho-para dependence for gas D2 wasfound to be the opposite of that in liquid and solid D2 .
According to a recent theory5) , the resonance condition could be modified by surrounding molecules (density effect). Thus far, the measurement with gas had
been carried out only up to 0.17-fold the liquid hydrogen density. We are planning an experiment to fill thedensity gap between liquid and gas using D2 near thecritical point.
∗1
∗2
∗3
∗4

JSPS FellowshipHigh Energy Accelerator Research Organization
Department of Physics, University of California, Riverside,
USA
RIKEN

References
1) K. Ishida et al.: RIKEN Accel. Prog. Rep. 39, 82 (2006).
2) H. Imao et al.: Phys. Lett. B 632, 192 (2006).
3) M.P. Faifman et al.: Muon Catalyzed Fusion 4, 1 (1989).
4) M.P. Faifman: private communication.
5) A. Adamczak et al.: Phys. Rev. A 64, 052705 (2001).

Fig. 1. Temperature dependence of resonant ddµ formation rate. The solid line represents a theory fit3) to thegaseous normal-D2 data and the dotted line represents
the increase for ortho-D2 predicted by the isolated gas
model4) .

Fig. 2. Relative increase in fusion neutron yield in ortho
D2 (Ynortho ) compared with that in normal D2 (Ynnorm )obtained in our two runs, E968 and E1061. Here, δYn =(Ynortho −Ynnorm )/(Ynortho +Ynnorm )/0.33. The factor 0.33
takes account of the difference of the ortho D2 fraction
in two targets. The dashed line shows a prediction forgas4) .

- 39 1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

Temperature dependence of muon transfer reaction†
N. Kawamura, K. Nagamine, T. Matsuzaki, K. Ishida, H. Imao, Y. Matsuda, S. N. Nakamura,∗1 M. Tanase,∗2
M. Kato,∗2 H. Sugai,∗2 K. Kudo,∗3 N. Takeda,∗3 and G. H. Eaton∗4[Muon catalyzed fusion, muon transfer reaction]

10

10

10

-1
-3

(a) 0-10 h(b) 10-20 h

1.2

Ct = 0.7
1

0.8

-4

(c) 20-30 h

0.6

Ct = 0.6
Ct = 0.5

0.4

0500 1000 1500 2000 2500 3000 3500 4000 4500 5000

Timing [ns]Ct = 0.3

Ct = 0.4

0.2-5

Ct = 0.1

Ct = 0.2

0
0

10

20

30

40

50

60

70

On the other hand, in the study of µCF in a solid
deuterium and tritium (D-T) mixture, we found that3
He from tritium β-decay accumulated in solid D-T2) .
Namely, 3 He increases with time after solidiﬁcation,and thus the probability for muon loss from the µCF
cycle (W ) increases, and consequently the neutron disappearance rate (λn ) also increases, as shown in Fig. 1.
From the tritium concentration dependence of the increase rate in W , the muon transfer rate from tµ to
3
He was determined to be about (4.3 ± 0.1) × 109 s−1
∗2
∗3
∗4

Fig. 2. Temperature dependence of muon transfer ratefrom muonic hydrogen to helium.

Time after solidification τ [h]Fig. 1. Typical time spectra of fusion neutrons at (a)τ = 0 − 10 h, (b) 10 − 20 h and (c) 20 − 30 h after solidiﬁcation. (left) Plot of the increase of λn , λn (τ ) − λn (0).
(right)∗1

at 16 K.
Applying this helium accumulation eﬀect, we can observe the temperature dependence of the muon transfer
rate. In order to determine the helium transfer rate,
it is required for all helium from tritium β-decay toaccumulate in the solid. However, because of sublimation due to β-ray heating3) , in some cases of formerµCF experiments, the D-T target was deformed andsome helium escaped from the solid. In a recent study,
this problem was solved using a specially prepared DT solid. Thus, at present, we are ready to take data.
The present study can be realized only at the RIKENRAL Muon Facility, where a pure (3 He free) solid D-Ttarget and an in-situ tritium gas-handling system areavailable.

1.4

λn(τ) - λn(0) [µs ]Fusion neutron / 50ns / spill

The muon transfer reaction from muonic hydrogento helium is an important problem in muon catalyzed
fusion (µCF) study as well as in mesic-atom study,
since this reaction occurs through the formation ofmuonic molecules: hµ + (He 2e− ) → [(hHeµ)e− ] + e− ,where h stands for a hydrogen isotope nucleus andHe for a helium one. An intermediate state, suchas tHeµ, is formed in an unstable excited state andthen deexcites to the dissociated ground state, i.e.,
triton and muonic helium, through a radiative processwith 6.8-keV photon emission or nonradiative process.
The transition rate from muonic hydrogen to helium
is predominately determined by the formation rate of
the intermediate muonic molecule. The formation rate
was expected to show an isotope dependence and alsostrong temperature dependence. In particular, in thecase of tµ and helium, the strongest temperature dependence was predicted1) . However, few experiments
have been conducted because of technical diﬃculties.

Department of Physics, Tohoku University
Japan Atomic Energy Agency
Advanced Industrial Science and Technology
Rutherford Appleton Laboratory

The present study was conducted at the RIKENRAL Muon Facility. An advanced tritium gas-handlingsystem, which had an in-situ 3 He-removal capability
with a palladium ﬁlter, was applied to prepare a D-T
mixture gas with the intended tritium concentration.
By controlling the cryogenic system, the target cell was
adjusted to a temperature from 5 to 16 K.
Figure 2 shows a preliminary result of the muontransfer rate that was determined by detecting fusion
neutrons. Through the present study, we found an
evidence of helium escape from solid hydrogen below
10 K. In order to gain further knowledge of the muontransfer reaction, this helium escape phenomenon must
be understood.
References
1) A. V. Kravtsov and A. I. Mikhailov; J. Exp. Theor. Phys.
90 (2000) 45.
2) N. Kawamura et al.; Phys. Lett. B 465 (1999) 74.
3) J. K. Hoﬀer and L. R. Foreman; Phys. Rev. Lett. 60(1988) 1310.

- 40 1

RIKEN Accel. Prog. Rep. 40 (2007)

Muon Transfer Reaction Studies in Solid Deuterium Films with
Implanted Ions
P. Strasser, ∗1 K. Nagamine, ∗2 T. Matsuzaki, K. Ishida, Y. Matsuda, and M. Iwasaki[Muonic atom spectroscopy, Solid hydrogen film, Ion implantation]∗1∗2

Events / 0.44 keV

800

(a)

µAr(2p→1s)µAr(2p→1s)
180

1000
600

160

900

140

800

500

120

700

100

600
300

600

650

700

500

600

Total Energy [keV]

Muon Science Laboratory, IMSS, KEK
Univ. of California Riverside, CA, USA- 41 -

700

40

200

30

150

20

100

~ 2 ppm
630

640~ 1 ppm

50
650

Delayed Energy [keV]

660

0

(f)

50

250

100

700

µAr(2p→1s)

60

300

150

650

70

µAr(2p→1s)

350

200

620

600

80

(e)

400

µAr(2p→1s)

5080

Total Energy [keV]

450

(d)

0

650

Total Energy [keV]

300
250

(c)

200

µAr(2p→1s)

1100

700

220

(b)

1200

400

Events / 0.44 keV

We proposed the cold hydrogen film method1) to expand muonic atom spectroscopy by utilizing nuclear
beams, including, in the future, radioactive isotope(RI) beams, to produce radioactive muonic atoms.
This method will enable the study of unstable nuclei
using the muonic X-ray method at facilities in which
both intense µ− and RI beams will be available. The
basic concept is to stop both µ− and nuclear beams
simultaneously in a solid hydrogen film, followed by
the application of the direct muon transfer reaction tohigher Z nuclei to form radioactive muonic atoms.
An experimental program to implant stable ions in asolid hydrogen (H2 /D2 ) film has been initiated at the
RIKEN-RAL muon facility to experimentally establish
the feasibility of this method. The first test experiments were performed with a relatively large numberof implanted argon ions, because of the relatively lowµ− beam intensity at 27 MeV/c. Future intense muon
beams will require fewer implanted ions. New measurements were performed with lower 40 Ar concentrations
to investigate the muon transfer reaction and the diffusion process of dµ atoms in pure solid D2 films withargon ions implanted non-uniformly. The advantage
of using a pure D2 film for the formation of µZ atoms,
compared with a pure H2 film, is that after ddµ muonic
molecule formation, the µ− is mostly released, while it
is lost after ppµ is formed. Since the range of 33-keV
Ar ions in solid D2 is only about 0.25 µm, with a range
straggling of 0.1 µm, it is very difficult to perform
a uniform implantation in a thick D2 layer. Consequently, each Ar implantation was separated from thenext by depositing a fixed amount of D2 to yield a total
D2 layer thickness of 1 mm. Every implantation region
was identical, with a local concentration of nearly 1000
ppm, and the distance between each implantation waschanged for each target. Figure 1 shows the total energy spectra measured by the Ge detector with 1-mm
pure D2 and (a) 20 implantations separated by 50 µm,(b) 10 implantations separated by 100 µm, and (c) 5
implantations separated by 200 µm, corresponding toaverage Ar concentrations throughout the D2 layer ofabout 2, 1, and 0.5 ppm. Even with an inhomogeneous target and only 5 implantations spaced 200 µm
apart, or a total concentration of 0.5 ppm, very strong
muon transfer µAr(2-1) X-rays at 644 keV can still be
detected. Unfortunately, owing to a trouble with thecompressor of the muon decay channel solenoid, only

620

630

640

~ 0.5 ppm

10
650

Delayed Energy [keV]

660

0

620

630

640

650

660

Delayed Energy [keV]

Fig. 1. Energy spectra with 1-mm pure D2 and about 2,
1 and 0.5 ppm of 40 Ar ions implanted non-uniformly.
Total energy spectra (top) and delayed events (bottom)
from 250 ns to 32 µ after the second muon pulse.

12 hours of data was accumulated. Because of themarked decrease in the Bragg cross section at a low
dµ collision energy in solid D2 2) , the dµ atom meanfree-path is significantly increased to nearly 10–20 µm
below ∼1 meV, resulting in a high dµ atom mobility and a very long diffusion length (similar effects are
predicted for pµ in solid H2 and tµ in solid T2 ). With
1 ppm, the number of argon ions implanted was 6 ×
1016 in an ∼4-cm-diameter and 1-mm-thick D2 film, or
6 × 1015 /cm2 . At a ppm level Ar concentration, mostof the muon transfer occurs delayed, and the S/N ratio can be greatly improved by selecting only delayed
events as shown in Figs. 1d, 1e and 1f, demonstrating
the advantage of using a pulsed muon beam.
Preliminarily, we can conclude that uniform implantation is not critical to observe a muon transfer reaction. A diffusion length of dµ atoms in solid deuteriumof approximately 20 µm can be extracted by fitting thedifferent X-ray yields as a function of the implantation
distance, which is consistent with the predicted value
based on calculated cross sections2) . This solid state
effect seriously limits the minimum layer thickness, andmakes the use of a very thin layer impossible becauseof the significant dµ loss.
References
1) P. Strasser et al.: Hyp. Int. 119, 317 (1999); Nucl.
Instr. and Meth. A 460, 451 (2001); AIP Conf. Proc.
793, 242 (2005).
2) A. Adamczak: Hyp. Int. 119, 23 (1999).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Coulomb breakup effects on elastic cross section of 6 He+209 Bi
scattering near Coulomb barrier energy
T. Matsumoto, T. Egami,∗1 K. Ogata,∗1 Y. Iseri,∗2 M. Kamimura, and M. Yahiro∗1[Nuclear reaction, unstable nuclei]

†
∗1
∗2

Condensed from the article in Phys. Rev. C 73, 051602(2006)
Department of Physics, Kyushu University
Department of Physics, Chiba-Keizai College

perimental data, whereas the dushed lines analyzed
by the CDCC based on the dineutron model of 6 He
underestimate the data at middle angles of 50◦ –100◦ .
Also, the total reaction cross sections calculated by
the four-body CDCC are in good agreement withthe experimental data. We thus conclude that then+n+4 He+209 Bi four-body reaction model is necessary for accurately describing 6 He+209 Bi scattering,and that the four-body CDCC is indispensable for analyzing low-energy 6 He scattering in which both nuclear
and Coulomb breakup processes are significant.
6

1

209

He+

Bi at 22.5 MeV

6

209

0.5

σ /σR

Recently, Keeley et al.1) have analyzed 6 He+209 Bi
scattering at 19 and 22.5 MeV near the Coulomb
barrier energy2,3) by a continuum-discretized coupledchannel method (CDCC)4) that is a fully quantummechanical method for describing the scattering of athree-body system. In the analysis, a 6 He+209 Bi system was assumed to be a 2 n+4 He+209 Bi three-bodysystem, that is, the neutron pair in 6 He was treated asa single particle, dineutron (2 n). However, their calculation did not reproduce the experimental data of theelastic and total reaction cross sections. This indicatesthat 6 He+209 Bi scattering cannot be described by thethree-body system. Since 6 He is well known as a twoneutron halo nucleus, its structure should be describedby an n+n+4 He three-body system rather than the2
n+4 He two-body system. Thus, it is necessary to analyze 6 He+209 Bi scattering using an n+n+4 He+209 Bi
four-body model.
In this work, we analyze 6 He+209 Bi scattering at
19 and 22.5 MeV using an n+n+4 He+209 Bi fourbody model that is an extension of the CDCC andis called a four-body CDCC. This is the first application of the four-body CDCC to low-energy scattering in which both nuclear and Coulomb breakup processes are significant. In the four-body CDCC, thethree-body breakup continuum of 6He is discretizedby diagonalizing the internal Hamiltonian in a spacespanned by a Gaussian basis function. Thus far, theGaussian basis function has been successfully used forsolving the bound-state problems of few-body systems.
This approach is called a Gaussian expansion method(GEM)5) .
In our previous work6) , we showed that the fourbody CDCC is successfully applied to 6 He+12 C scattering at 18 and 229.8 MeV in which only nuclear
breakup is significant. Furthermore, the applicabilityof the four-body CDCC with the GEM to Coulomb
breakup processes was also shown in Ref. 7. Thus, it
is expected that the four-body CDCC with the GEM
will accurately describe four-body breakup reactions
near the Coulomb barrier energy.
Figure 1 shows the angular distributions of the measured elastic cross sections for 6 He+209 Bi scattering
at 19 and 22.5 MeV. We found that the solid lines
analyzed by the four-body CDCC reproduce the ex-

0
1

0.5

He+

Bi at 19 MeV

Four−body CDCC
(full coupling)Three−body CDCC
(full coupling)

0
0

60

120

θc.m. [deg]180

Fig. 1. Angular distributions of elastic differential crosssection as a ratio to the Rutherford cross section for
6
He+209 Bi scattering at 19 and 22.5 MeV.

References
1) N. Keeley et al.: Phys. Rev. C 68, 054601 (2003).
2) E. F. Aguilera et al.: Phys. Rev. Lett. 84, 5058 (2000).
3) E. F. Aguilera et al.: Phys. Rev. C 63, 061603(R)(2001).
4) M. Kamimura et al.: Prog. Theor. Phys. Suppl. 89, 1(1986).
5) E. Hiyama et al.: Prog. Part. Nucl. Phys. 51, 223(2003).
6) T. Matsumoto et al.: Phys. Rev. C 70, 061601 (2004).
7) T. Egami et al.: Phys. Rev. C 70, 047604 (2004).

- 43 1

RIKENRIKENAccel.
Accel.Prog.
Prog.Rep.
Rep. 40
39(2007)(2006)

Nonadiabatic dynamics in 10 Be with α+α+N +N model†
M. Ito[NUCLEAR STRUCTURE, cluster model, unstable nuclei]†

Partial Cross Section ( mb )
−80
−40

−120

Excitation Energy ( MeV )In the last two decades, developments of experimentswith a secondary RI beam have extensively proceededin terms of studies on light neutron-rich nuclei. In
particular, much eﬀort has been devoted to the investigation of the molecular structure of Be isotopes.
Theoretically, molecular models with π and σ orbitals
along the α − α axis have been successful in making us
understand the low-lying states of this isotopes1) .
In recent experiments, the reaction cross-sections induced by the low-energy 6 He beam have been accumulated. In future experiments, it will also be possible toinvestigate the molecular states of Be isotopes throughreactions by 6 He beams. Therefore, it is very interesting to study theoretically the low-energy scattering of
6
He by an α target.
In studying the reaction processes exciting themolecular states, it is very important to construct a
uniﬁed model that is capable of describing both structure and reaction on the same footing. For this purpose, we proposed a microscopic model, the generalized
two-center cluster model (GTCM)2,3) . In this study,
we apply GTCM for 10 Be with the α+α+N +N structure.
In GTCM, the total wave function is expressed bya linear combination of the “atomic-orbitals” (AOs)
around two α cores. The α particle is described bythe (0s)4 conﬁguration and the valence neutrons are
speciﬁed by the atomic orbitals in which the neutrons
are localized at one of the α cores with 0p orbitals.
In the calculation, the α–α distance S and the mixing
weights among the AOs are treated as variational parameters. In the region where two α-cores are near, thetotal system is expected to form the molecular orbital
structure (π − , σ + ,...), whereas in the region where
two core nuclei are far apart, the molecular orbitals
smoothly change into product wave functions consisting of atomic orbitals.
We can obtain adiabatic energy surfaces (AESs) by
diagonalizing the Hamiltonian at a ﬁxed S, whereas
the energy spectra are calculated by solving the eigenvalue problem with the variation in both the S and
the AO weights. In Fig. 1, the AES and energy spectra for J π =1− are shown. We have identiﬁed two 1−
states having the (π − σ + ) conﬁguration. The lower
state is generated from the AES around the lowest local minimum, whereas the higher state originates fromthe higher AES, as indicated by the arrow in Fig. 1.
Around S=6 fm, we can clearly observe the avoided
crossing between the lowest AESs. In the asymptotic

0

10

+

-

( p 1/2 σ1/2 )

0

-

+

( p 3/2 σ1/2 )

0

a

4
a-a

8
Distance ( fm )6

+ Heg.s.

12

Fig. 1. Energy spectra (horizontal bars) and adiabatic energy surfaces (dotted curves) for J π =1− . The error
bar means the decay width of the resonance state. The
solid curve shown in the right part is the partial crosssection for the inelastic scattering [α+6 Heg.s. ]L=1 →[α+6 He(2+1 )]L=1 with a respective scale at the up-mostaxis.

region, the lowest AES and the ﬁrst excited AES cor+
6
respond to the [α+6 He(0+1 )]L=1 and [α+ He(21 )]L=1
channels, respectively.
We next discuss how the AES proﬁle appears in the
low energy reactions. We show the partial cross section for the inelastic scattering to 6 He(2+1 ) excitation.
A strong enhancement can be observed at Ec.m. ∼ 6
MeV. The energy of the enhancement is quite similar
to that of the avoided crossing at S=6 fm. We have
solved the coupled-channel problem between the lowest AESs and conﬁrmed that this peak is generated by
the coupling between the lowest two AESs. Therefore,
we can conclude that this inelastic peak is due to theLandau Zener transition at the avoided crossing.
The present calculation predicts the enhancement in
the cross section for the inelastic scattering α+6 Heg.s.
→ α+6 He(2+Therefore, an experiment on the
1 ).
α+6 He low energy scattering is strongly desired.
References
1) N. Itagaki, S. Okabe and K. Ikeda : Phys. Rev. C 62,
034301 (2000), and references therein.
2) M. Ito, K. Kato and K. Ikeda : Phys. Lett. B588, 43(2004).
3) M. Ito and K. Yabana : Prog. Theor. Phys. 113, 1047
(2005)

Condensed from the article in Phys. Lett. B636, 293 (2006)- 44 -

1

RIKENRIKENAccel.
Accel.Prog.
Prog.Rep.
Rep. 40
39(2007)(2006)†
α+12 C inelastic angular distribution and nuclear size of 12 C(0+2)
M. Takashina∗1 and Y. Sakuragi∗2[Nuclear reaction, α condensate state]
Recently, it was proposed1,2) that the 0+
2 state in
C could be interpreted as an α-particle condensate
state. One of the remarkable features of the α condensed state is a dilute density distribution, resulting
in a large nuclear radius of the state. Therefore, if thelarge nuclear radius of the candidate state is experimentally conﬁrmed, it will be strong evidence indicating the formation of the α condensed state. However,the direct measurement of the nuclear radius or nucleon density distribution of excited states is not possible at the moment. Therefore, an indirect procedureis necessary to prove the dilute density distribution of
excited states. In the present study, we investigate
how the spatial extension of the 0+
2 state is reﬂectedin the details of the angular distribution of inelastic α
scattering.
We perform the microscopic coupled-channel (MCC)
calculation based on the double-folding model using the DDM3Y interaction for the eﬀective nucleonnucleon interaction. The density distribution of 12 C isgiven by α condensate model (ACM) calculations2,3) .
We refer to the ACM wave function originally obtained2) as the original ACM, and those for which thespatial extension of the 0+
2 state is artiﬁcially modiﬁed3) as the modiﬁed ACM. We use four types of modiﬁed ACM wave functions (i) ∼ (iv), the root-meansquare (rms) radii hr2 i1/2 of which are (i) 2.97 fm, (ii)3.55 fm, (iii) 4.38 fm and (iv) 5.65 fm, while that of theoriginal ACM wave function is 3.81 fm3) . Note that the+orthogonality of the 0+
2 state and the 01 ground-state
wave functions is also satisﬁed in the modiﬁed ACM
calculation. The transition density between the groundand the 0+
2 states is calculated from the ground-state
wave function and each of these wave functions for
the 0+
2 state. The ground-state wave function is not
modiﬁed throughout the present analysis. The normalization factor NR of the real folded potential andthe parameters for the Woods-Saxon-type imaginary
potential are taken to be the same as those used inRef.4.
The result of the MCC calculation for the
α+12 C(0+2 ) channel at the incident energy of Eα =240
MeV is shown in Fig. 1. The solid curve represents
the result using the original ACM wave function. The
other curves are the results of the MCC calculations
in which the modiﬁed ACM wave functions (i) - (iv)†∗1∗2Condensed from the article in Phys. Rev. C 74, 054606(2006).
Yukawa Institute for Theoretical Physics, Kyoto University
Department of Physics, Osaka City University- 45 -

dσ/dW(mb/sr)

12

10

4

10

2

10

0

02

+

(i)
(ii)
original
(iii)
(iv)
ACM

−2

10 0

20
θcm (deg)40

Fig. 1. The inelastic angular distribution of α+12 C(0+2 )channel at the incident energy of Eα =240 MeV. The
solid curve represents the result using the original ACM,
while the other curves represent the results using themodiﬁed ACM.

are used, where we use the same Woods-Saxon-type
imaginary potential as that used in the calculations forthe solid curves. It is found that the oscillation pattern of the angular distribution is hardly changed evenwhen the density distribution of the 0+
2 state is artiﬁcially shrunk or extended, although the absolute valuechanges. This is because the change in the nuclear
radius of the excited 0+
2 state does not signiﬁcantly
aﬀect the shape of the transition density between the
ground state and the 0+
2 state, but it only changes themagnitude of the transition density, as shown in Ref.3.
In the present study, it is found that the numberof minima and their positions in the inelastic angular
distribution are almost unchanged by the modiﬁcationof the nuclear radius of the 0+
2 state. However, the nuclear radius of the excited state can be deduced fromthe absolute value of the inelastic diﬀerential cross sections, as shown in Fig. 1, through the amplitude of thetransition density calculated in a microscopic nuclear
structure model such as ACM.
References
1) A. Tohsaki et al.: Phys. Rev. Lett. 87, 192501 (2001).
2) Y. Funaki et al.: Phys. Rev. C 67, 051306 (R) (2003).
3) Y. Funaki et al.: Eur. Phys. J. A 28, 259 (2006).
4) S. Ohkubo and Y. Hirabayashi: Phys. Rev. C 70,
041602 (R) (2004).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Cluster states in 13 C(1/2−
3)
Y. Kanada-En’yo,∗1[NUCLEAR STRUCTURE, Unstable nuclei, Cluster]∗1

the lowest 12 orbits form the 3α core and the ﬁnal neutron has a nature of valence nucleon. It is expectedthat the valence neutron plays an important role toform the compact cluster structure in the 13 C(1/2−
3 ).
In conclusion, the cluster state with the 3α+n struc13
ture appears in the 1/2−
C. It is found that
3 state of
the state is not a cluster gas with a dilute density but
a compact state with the 3α core and the valence neutron.
Table 1. Excitation energies and root mean square radii ofthe 1/2− states of 13 C.

Jkπ
1/2−
1
1/2−
2
1/2−
3

exp.
Ex (MeV)
0.0
8.86
11.08

theor.
Ex (MeV) r.m.s.r.(fm)
0.0
2.5
11.3
2.6
13.8
2.7

MeV

Single particle energy

The present study has been motivated by the recent
works on three-center cluster states in excited states of
12
C and 11 C. In 12 C, it is known that 3α-cluster statesdevelop in such the excited states as the 0+
2 (7.65 MeV)
state. Recently, Tohsaki et al.1,2) proposed that the0+
2 is a dilute state which is considered to be a weaklyinteracting gas of 3 α particles. Similar states of thecluster gas have been suggested in the excited states of11
C, 11 B3) and 16 O1,4) . It leads to a question whether
such loosely bound multicluster states may appear inother nuclear systems.
In the present paper, we focus on the excited states12of 13 C. As we mentioned, the 0+
C is re2 state ofgarded as a 3α-cluster gas with a dilute density. Considering the 3α + n system, it is natural to expect apossible cluster gas state with an additional neutron in
13
C. Our aim here is to theoretically study the struc−ture of the 1/2−
2 and 1/23 states, which are the candidates of cluster gas states, and clarify their cluster
aspect.
We apply the method of antisymmetrized molecular
dynamics (AMD). We perform energy variation after
spin parity projection (VAP) within the AMD model
space, as was done in the previous studies5,6) . The
adopted interaction consists of the central force of MV1(m = 0.62, b = h = 0.20), the spin-orbit force of GSRS(uI = −uII = 3000 MeV), and Coulomb force.
In Table 1, we show the calculated excitation energies and root mean square radii(r.m.s.r.). The experimental data of the M 1 transition strengths are well
reproduced by the present calculations. Therefore, the−theoretical 1/2−
2 and 1/23 should be assigned to the−observed 1/22 at 8.86 MeV and the 1/2−
3 at 11.08
MeV, though the excitation energies are overestimatedby the theory. By analyzing the obtained wave function, we ﬁnd that the ground and the 1/2−
2 states haveno cluster structure, while the 1/2−
hasacluster state3
with the 3α+n structure. One of the interesting points
is that the spatial development of the cluster state is
not remarkable. As a result the radius of the 1/2−
3 is
not large as shown in table 1. This results indicatethat the 1/2−
3 is not a cluster gas with a dilute density
but a compact state with the 3α core. Comparing the11
dilute cluster structure in the 12 C(0+B(3/2−
2 ) and3 ),−13
the cluster aspect in the C(1/23 ) diﬀers from thoseof the cluster-gas states. In Fig.1, the single particle
energies of protons and neutrons in the 1/2−
3 are displayed. It clearly indicates 3α + n structure. Namely,

0
-10
-20
-30
-40

protonneutron-50
Fig. 1. Single particle energies of the calculated 1/2−
3 stateof 13 C.

References
1) A. Tohsaki et al., Phys. Rev. Lett. 87, 192501 (2001).
2) Y. Funaki et al., Phys. Rev. C 67, 051306 (2003).
3) T. Kawabata et al., Phys. Lett. B646, 6 (2007).
4) T. Yamada and P. Schuck, Phys. Rev. C 69, 024309(2004).
5) Y. Kanada-En’yo, Phys. Rev. Lett. 81, 5291 (1998).
6) Y. Kanada-En’yo, H. Horiuchi and A. Doté, Phys. Rev.
C 60, 064304 (1999).

Yukawa Institute for Theoretical Physics, Kyoto University,Japan- 46 -

1

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)

Fusion reaction of 15 C+144 Sm
M. Ito, K. Yabana,∗1 and T. Nakatsukasa∗1[NUCLEAR REACTION, unstable nuclei]+VnC (r) + VCT (RCT ) + VnT (rnT )} Ψ(R, r, t), (1)where the relative n-C coordinate is r and the relative
P -T coordinate is R. The reduced masses of the n-C
and P -T motions are m and µ, respectively. We prepare an initial wave packet boosted toward collision,then calculate the time evolution in real coordinate
space. Fusion is identiﬁed as the ﬂux loss due to theimaginary part of the core-target potential, VCT (RCT ).
The energy projection before and after the time evolution gives fusion probability as a function of energy. In
Fig. 1, we show the calculated fusion cross section of
15
C+144 Sm. The result of the three-body calculation∗1

Institute of Physics, University of Tsukuba- 47 -

clearly predicts a slight hindrance compared with thatin the case of the fusion cross section for the system
without a neutron halo, 14 C+144 Sm.
310

Fusion Cross Section (mb)

Nuclear reactions involving halo nuclei have been attracting the attention of many researchers since thediscovery of halo structures in a secondary beam experiment. For reactions at medium and high incident
energies, the Glauber and eikonal approximations havebeen successful. In a low-energy collision, however, thereaction mechanism of halo nuclei remains an open
question in spite of the many experimental and theoretical studies that have been performed in the last
decades.
To elucidate the reaction mechanism of a halo nuclei at low incident energies, we have been developing a time-dependent wave-packet approach using thethree-body reaction model1–4) . In our previous studies, we have applied this method to the sub-barrier
fusions of the 11 Be+209 Bi and 6 He+238 U systems andhave shown that fusion cross sections are suppressedby the presence of a neutron halo4) . In this paper, we
present our extended analyses of the 15 C+144 Sm system that will be measured in a future experiment5) .
15
C is a weak binding system (Sn =1.2MeV) and its
spectroscopic factor is close to unity for the s-wave
14
C+n conﬁguration5) in contrast to that for anothertypical one-neutron halo system, 11 Be, that has about
20% d-wave components with a deformed 10 Be core.
Therefore, 15 C is a model case for maximizing the effect of a dilute system in solving a multidimensionaltunneling problem.
We adopt a three-body model of a halo nucleon (n)and a core nucleus (C) constituting the projectile (P =C +n) colliding with a target nucleus (T ). The method
is based on the time-dependent Schrödinger equation
for the three-body model given as
{
∂
h̄2 2
h̄2
ih̄ Ψ(R, r, t) = − ∇2R −
∇
∂t
2µ
2m r

2

10

1

10

0

1040

45

50

55

60

65

Ec.m. (MeV)

Fig. 1. Fusion cross section as function of incident energy.
The solid curve shows the result of the three-body calculation, whereas the dotted one shows the cross sectionof the 14 C+144 Sm system. The dashed curve indicatesthe fusion cross section obtained by solving the singlechannel problem of 15 C+144 Sm. See text for details.

In the same ﬁgure, we also show the result of thesingle-channel calculation for 15 C+144 Sm. In this calculation, 15 C is frozen to its ground state with a halo
structure and the scattering problem is solved by employing the static potential between 15 Cg.s. and 144 Sm.
The fusion cross section of the single-channel calculation becomes much larger than that of 14 C+144 Sm.
This is due to the extended nuclear interaction generated by the halo eﬀect in 15 Cg.s. . This behavior canbe seen in many previous studies on fusion reaction using neutron-halo systems, but such enhancement completely disappears when we explicitly solve three-bodydynamics. According to our studies, we expect a slighthindrance of the fusion cross section in future experiments on 15 C+144 Sm.
References
1) K. Yabana : Prog. Theor. Phys. 97, 437 (1997).
2) K. Yabana, M. Ito, M. Kobayashi, M. Ueda, T. Nakatsukasa : Nucl. Phys. A738, 303 (2004).
3) T. Nakatsukasa, K. Yabana, M. Ito, M. Kobayashi, M.
Ueda : Prog. Theor. Phys. Suppl. 154, 85 (2004).
4) M. Ito, K. Yabana, T. Nakatsukasa, M. Ueda : Phys.
Lett. B637, 53 (2006), and references therein.
5) A. Navin, private communications.

1

RIKEN Accel. Prog. Rep. 40 (2007)

An s-wave halo structure of 22C†
W. Horiuchi∗1 and Y. Suzuki∗2[Nuclear structure, unstable nuclei]

†
∗1
∗2

Condensed from the article in Phys. Rev. C 74, 034311(2006).
Graduate School of Science and Technology, Niigata University
Department of Physics and Graduate School of Science andTechnology, Niigata Universitythat ρh /2 is, roughly speaking, the square of the single halo-neutron wave function. The two neutrons are
predominantly in (s1/2 )2 orbits more than 90 percent,and that the non-central forces play no active role inbinding this fragile system. In a separate study, we use
the density obtained this work to calculate the reaction
cross section of 22 C.
To conclude, we studied the ground state structureof 22 C in the 20 C+n+n three-body model with the orthogonality constraint. The N =14 subshell closure wasassumed for 20 C. We showed that 22 C is an almost pures-wave two-neutron halo nucleus. A measurement of
the reaction cross section of 22 C is desired to establish
the halo structure experimentally.
The authors thank A. Kohama for his interest andvaluable discussions.
References
1) A. Ozawa et al., Phys. Rev. Lett. 84, 5493 (2000).
2) P. G. Thirolf et al., Phys. Lett. B485, 16 (2000).
3) D. Cortina-Gil et al., Phys. Rev. Lett. 93, 062501(2004).
4) M. Stanoiu et al., Phys. Rev. C 69, 034312 (2004).
5) E. Becheva et al., Phys. Rev. Lett. 96, 012501 (2006).
6) T. Yamaguchi et al., Nucl. Phys. A724, 3 (2003).
7) W. Horiuchi and Y. Suzuki, Phys. Rev. C 73, 037304(2006).
8) T. Nakamura et al., Phys. Rev. Lett. 83, 1112 (1999).
9) V. Maddalena et al., Phys. Rev. C 63, 024613 (2001).
10) A. Ozawa, T. Suzuki and I. Tanihata, Nucl. Phys.
A693, 32 (2001).
11) K. Tanaka et al., private communication.

10-1

ρn
ρcn
ρh

10-2

-3

ρ(r)[fm ]The subshell closure of N =14 and N =16 is one of
the intensively discussed topics in the study of neutronrich nuclei, and the N =14 closure has been confirmed
experimentally around 22 O1–5) . This issue is closely
related to the competition of 0d5/2 and 1s1/2 neutron
orbits. In fact, they play a vital role in determining the
ground state structure of A=15–20 carbon isotopes.
For example, the ground state of 16 C is found to contain the (1s1/2 )2 and (0d5/2 )2 configurations almost
equally6,7) , whereas the last neutron in 19 C is in the
1s1/2 orbit, forming one-neutron halo structure8,9) .
No information is available to determine whether the
N =14 subshell closure occurs in 20 C. The systematicsof the interaction cross section suggests, however, thatthe radius of 20 C is smaller than that of 19 C10) , so it
is natural to assume that the ground state of 20 C predominantly consists of a (0d5/2 )6 configuration. If its
dominant component were (0d5/2 )4 (1s1/2 )2 , one moreneutron could be added to the 0d5/2 orbit to form aparticle-stable 21 C, which is in contradiction to obserbed results.
In this study, we will demonstrate that 22 C is an swave two-neutron halo nucleus on the basis of the analysis of its structure including the neutron and protondensities. For Z ≤ 8, 22 C is the only dripline nucleus
for which the interaction or reaction cross section measurement on a 12 C target has not reached yet10) , so it
is of interest for future measurement to predict the reaction cross section of 22 C. The neutron and protondensities obtained here will be useful for estimating
the reaction cross section of 22 C on a proton target,
which is being investigated experimentally11) .
Our model is that 22 C is a three-body system of
20
C+n+n, and that 20 C has the (0d5/2 )6 configuration. The valence neutrons, interacting via a realistic
potential, are constrained to be orthogonal to the occupied orbits in 20 C. We obtain ample results supporting the fact that 22 C is an ideal s-wave two-neutron
halo nucleus: The ground state is bound by 390-570
keV, the root mean square neutron and proton radii
are 4.0 and 2.4 fm, respectively. The matter radius
is 3.6 fm, which corresponds to that of a stable nucleus with A ≈ 60. These densities are displayed inFig. 1. The contribution of the halo density to ρn exceeds that of the core density beyond r = 6.1 fm. Note

10

ρp
ρcp

-3

10-4
10-5
10-6
0

5

10

15

20

r [fm]

Fig. 1. The neutron and proton densities of 22 C and 20 C.
ρh is the halo-neutron density.

- 48 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Systematic analysis of reaction cross sections of carbon isotopes
B. Abu-Ibrahim,∗1 W. Horiuchi,∗2 A. Kohama, and Y. Suzuki,∗3[Nuclear reaction, total reaction cross sections, unstable nuclei]

∗1
∗2
∗3

Department of Physics, Cairo University, Egypt
Graduate School of Science and Technology, Niigata University
Department of Physics and Graduate School of Science andTechnology, Niigata University- 49 -

other RIKEN research group.
There exist some data for the reactions of the carbon
target, and we observed that both of our two schemes
successfully reproduce low and high incident energy
data on the cross sections of 12 C, 13 C and 16 C on
12
C. The calculated reaction cross sections of 15 C arefound to be considerably smaller than the empiricalvalues observed at a low energy. We find a consistentparameterization of nucleon-nucleon scattering amplitude, which is different from that previously reported.
Finally, we predicted the total reaction cross section of
22
C on 12 C (Fig. 1).
Our framework offers a prescription for the simple,
consistent analyses of a broad range of reaction crosssection data for neutron-rich unstable nuclei. Suchdata are expected to be provided by radioactive ion
beam facilities, such as GSI and Radioactive Ion Beam
Factory at RIKEN.
References
1) N. Imai et al.: Phys. Rev. Lett. 92, 062501 (2004).
2) Z. Elekes et al.: Phys. Lett. B 586, 34 (2004).
3) W. Horiuchi and Y. Suzuki: Phys. Rev. C 74, 034311(2006).
4) R. J. Glauber: Lectures in Theoretical Physics (Interscience, New York, 1959) Vol. 1, p.315.
5) B. Abu-Ibrahim and Y. Suzuki: Phys. Rev. C 61,
051601(R) (2000).

4400

NTG

4000
3600
σR [mb]The structure of carbon isotopes has recently attracted considerable attention as experimental information accumulated toward its neutron dripline. The
topics discussed include, for example, the subshell closure of N =14 and N =16, and the anomalously small
E2 transition strength observed in 16 C.1,2) These topicss are closely related to the competition of 0d5/2 and1s1/2 neutron orbits. In fact, they play a predominant role in determining the ground state structure ofa carbon isotope with N > 8.
In this study, we systematically analyzed the total
reaction cross sections of carbon isotopes with N = 6–
16 on a proton target as well as on a 12 C target for awide incident energy range of 40 to 1000 A MeV. The
papers regarding this study are in preparation and will
be submitted soon.
The intrinsic structure of the carbon isotopes isfirstly described by a Slater determinant generated
from a phenomenological mean-field potential. WoodsSaxon-type potential depth is determined separately
for neutrons and protons to reproduce nucleon separation energies. The intrinsic density of each carbon
isotope is constructed from the single-particle statesby separating, in a good approximation, the center ofmass motion from the Slater determinant.
Our model reasonably well describes the groundstates of even N isotopes, but the mean-field potential
depth of odd N isotope tends to be too small, yielding
too large neutron and matter radii. This unrealisticfeature has been largely improved by performing separate studies which take into account the specific structure of core+n. We also utilized the core+n+n threebody model for 16 C and 22 C,3) in order to consider
the mixing of the sd orbits in 16 C and the Borromean
character of 22 C, respectively.
For the calculations of the cross sections of the carbon target, we sed two schemes: the Glauber approximation4,5) , and the eikonal model using a global optical potential. By setting the parameters of nucleonnucleon scattering amplitude, we calculated the crosssections of the proton target. Empirical data exist only
for a proton-12 C reaction, and the agreement of our numerical results with the data is fairly well. The numerical results for the other carbon isotopes are obtained
as predictions. The experimental results for some isotopes including 22 C are reported in this volume by an-

3200
2800
2400

OLA
(+800mb)

NTO
Vs=10.9

2000
1600
1200

Vs=9.46
100
incident energy [A MeV]

1000

Fig. 1. Prediction of total reaction cross section for collisionof 22 C on 12 C target as a function of incident energy.
Vs is parameter for controling the s wave strength of
the n-20 C relative motion.

1

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)

Study of the tensor correlation in 17 O using the shell model
S. Sugimoto,∗1 K. Ikeda,∗2 and H. Toki∗3[Nuclear structure, tensor correlation, shell model]
The tensor force plays important roles in a nuclear structure. The study of nuclear matter with theBrueckner theory showed that the tensor force has alarge effect on the binding mechanism and is related
to the saturation property of nuclear matter. Variational calculations with very large model spaces exhibit
a large attractive energy from the tensor force. The
tensor force seems to be responsible for about one-halfof the single-particle ls splitting in light nuclei1) .
Recently, we have developed a mean field framework(a charge- and parity-projected Hartree-Fock (CPPHF) method) that can treat the two-particle–twohole (2p-2h) correlations induced by the tensor force.
To treat the tensor correlation, we introduce singleparticle states with parity and charge mixing, inspiredby the pseudoscalar and isovector character of a pion,
which mediates the tensor force. We applied the CPPHF method to the alpha particle3) , 8 Be4) , and oxygen isotopes5) , and obtained sizable potential energies
from the tensor force for these nuclei.
Because the CPPHF method is based on a mean
field model, the correlations that can be treated by
the CPPHF method are limited. Shell model calculations with 2p-2h configurations were performed by
Myo and his collaborators1,6) . They found that a large
correlation energy from the tensor force is obtained byintroducing single-particle wave functions for particle
states with small range-parameters compared with theones of typical harmonic oscillator wave functions. The
importance of the single-particle wave functions withsmall range-parameters for the tensor correlation was
also observed in our mean field calculations3,5) . Furthermore, the shell model calculations indicate thatthe configurations that cannot be considered by the
CPPHF method are important for the tensor correlation1,6) . The shell model calculations also reveal thatthe tensor correlation is responsible for the ls-splitting
in a 4 He-n system1) . Therefore, it is interesting and important to study the tensor correlation in large-massnuclei, such as oxygen, using the shell model.
Here, we show the result of the shell model calculation for 17 O. On the basis of the paper by Myo andhis collaborators1,6) we introduce single-particle wave
functions with the Gaussian form for particle states in
addition to typical harmonic oscillator single-particle
wave functions. The range parameters for the Gaus∗1∗2∗3

Table 1. Results for 17 O. E, T , VC , VT , and VLS are thetotal energy, the kinetic energy, and the potential energies from the central, tensor, and LS forces, respectively.
These are given in MeV. In the last row, the differences
between the values of the J π = 5/2+ and J π = 3/2+
cases are shown.
5/2+
3/2+
diff

E
-132.2-127.7
-4.5

T
289.5
288.6
0.8

VC
-357.4-356.7
-0.6

VT
-57.0
-56.7
-0.2

VLS
-7.3
-2.8
-4.5

sian wave functions are about one-half of those of theharmonic oscillator wave functions (bHO =1.8fm). As
for the orbital angular momenta l of single-particle
states, we consider l values up to l=3 (f -orbit). In
Table 1, the results for the spin-orbit partners in 17 O
are shown. We consider the Volkov force No. 17) forthe central part, the G3RS force8) for the LS part, andthe Furutani force9) for the tensor part. The central
force is reduced by 10%. In this case, the total energyof 16 O is −132.5MeV. The large potential energy fromthe tensor force is about −60MeV. The ls splitting results in an energy of 4.5MeV, which is comparable tothe experimental data. The ls splitting mainly comesfrom the LS force. The contribution from the tensor
force is small. The contributions for the ls splittingfrom the kinetic energy, central force and tensor force
almost cancel out each other. The small effect on thels splitting of the tensor force compared with the 5 Hecase is probably attributed to the multiplicities of thed-orbits lager than those of the p-orbits.
References
1) T. Myo, K. Katō, and K. Ikeda, Prog. Theor. Phys.
113, 763 (2005).
2) T. Otsuka, T. Suzuki, R. Fujimoto, H. Grawe, andY. Akaishi, Phys. Rev. Lett. 95, 232502 (2005).
3) S. Sugimoto, K. Ikeda, and H. Toki, Nucl. Phys. A 740,
77 (2004).
4) S. Sugimoto, K. Ikeda, and H. Toki, nucl-th/0511087.
5) S. Sugimoto, K. Ikeda, and H. Toki, nucl-th/0607045.
6) T. Myo, S. Sugimoto, K. Katō, H. Toki, and K. Ikeda,
nucl-th/0607059.
7) A. B. Volkov, Nucl. Phys. 74, 33 (1965).
8) R. Tamagaki, Prog. Theor. Phys. 39, 91 (1968).
9) H. Furutani, Prog. Theor. Phys. Suppl. 68 193 (1980).

Department of Physics, Graduate School of Science, Kyoto
University
The Institute of Physical and Chemical Research (RIKEN)
Research Center for Nuclear Physics (RCNP), Osaka University- 50 -

1

RIKEN
Accel.
Prog.
Rep.
4039
(2007)
RIKEN
Accel.
Prog.
Rep.
(2006)

Exotic structure of unstable nuclei around N=28 due to tensor force
Y. Utsuno,∗1 T. Otsuka,∗2,∗3 T. Mizusaki,∗3,∗4 and M. Honma,∗5[NUCLEAR STRUCTURE, shell model, unstable nuclei]

∗1
∗2
∗3
∗4
∗5

Advanced Science Research Center, Japan Atomic Energy
AgencyDepartment of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
Institute of Natural Sciences, Senshu University
Center for Mathematical Sciences, University of Aizu

- 51 -(a)+Ex (MeV)

3

4

2

+

MK

2
1

GT2

0
600

(b)

2

4

B(E2) (e fm )The evolution of the shell structure in exotic nuclei isan intriguing issue and should be clarified by RIBF at
RIKEN in the near future. The disappearance of theN = 20 magic number is most likely related to a narrowing N = 20 shell gap toward smaller proton number, which has been investigated by a large-scale shellmodel calculation with the Monte Carlo shell model(MCSM)1) . It has been recently pointed out2) that thechange of the shell structure, often called shell evolution, is caused by the tensor force. It is very successfulin accounting for similar phenomena for spherical nuclei in other regions.
In the present study, we examine whether or not
this leads to an exotic nuclear structure such as an unexpected deformation using the shell model. We focus
especially on persistence or disappearance of the magic
structure around N = 28 in the very neutron-rich region, where the sd-pf cross shell interaction plays a
key role. The shell model can treat the deformationand the correlation in a proper way. This study isconducted as a RIKEN-CNS collaboration project onlarge-scale nuclear structure calculations.
To investigate the proper strength of the tensor force
as the shell-model effective interaction, we extract thetensor part from the GXPF1 interaction3) for pf -shell
nuclei. Since GXPF1 is an interaction that excellently
reproduces and predicts many nuclear properties over
the region, it should have a reasonable spin/isospin
structure. As a result, the monopole centroid of the
T = 0 tensor force in GXPF1 is very similar to that ofthe π+ρ exchange force and the GT2 interaction4) thathas been newly constructed for the mean-field calculation. Thus, the tensor force in the shell-model interaction seems similar to that of mean-field calculation
and almost independent of region.
Based on the above discussion, we construct a new
sd-pf shell Hamiltonian whose tensor force of thecross-shell part is identical to GT2 (hereafter simply
denoted by GT2). As a reference, a Hamiltonian withthis part replaced by Millener-Kurath (MK) tensor
force5) is also constructed, and we compare results between them. Note that the tensor force of MK is about
one third as weak as that of GT2.
The shell-model calculation shows that GT2 well reproduces the reduction of the Z = 16 shell gap moving

400
200
0

22

24

26

28

N
+
+
Fig. 1. (a) 2+
1 and 41 energy levels and (b) B(E2; 01 →+21 ) values of Si isotopes from N = 22 to 28 compared between experiment (circles) and shell-model calculations with different cross-shell interactions MK and
GT2.

from N = 20 to 28 such as the inversion of the or+47dering between 1/2+
K, whereas
1 and 3/21 states in
MK does not sufficiently. The tensor force affects theZ = 14 shell structure and relevant nuclear structure,
too. Figure 1 shows the low-lying structure of neutronrich Si isotopes. The present calculation predicts that
the N = 28 isotope 42 Si is not a typical magic nucleus
due to a narrower the Z = 14 shell gap by the tensor
force, which will be accessible by RIBF.
References
1) Y. Utsuno, T. Otsuka, T. Glasmacher, T. Mizusaki and
M. Honma: Phys. Rev. C 70, 044307 (2004).
2) T. Otsuka, T. Suzuki, R. Fujimoto, H. Grawe andY. Akaishi: Phys. Rev. Lett. 95, 232502 (2005).
3) M. Honma, T Otsuka, B.A. Brown and T. Mizusaki:
Phys. Rev. C 69, 034335 (2004).
4) T. Otsuka, T. Matsuo and D. Abe: Phys. Rev. Lett. 97,
162501 (2006).
5) D.J. Millener and D. Kurath: Nucl. Phys. A 255, 315(1975).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Effective interaction for f5pg9-shell nuclei and two-neutrino
double-beta-decay matrix elements†
M. Honma,∗1 T. Otsuka,∗2 T. Mizusaki,∗3 and M. Hjorth-Jensen∗4[shell model, effective interaction, double beta decay]
Effective interaction is a key ingredient for successful shell-model calculations. Owing to recent developments in computers as well as novel numerical techniques such as the Monte Carlo shell model1) , the applicability of the shell model is rapidly expanding. On
the other hand, our knowledge of the effective interaction is still insufficient, particularly for cases wheremore than one major shell should be taken as the active valence space. Such a treatment is essential for
describing neutron-rich nuclei.
We have developed a new effective interaction forshell-model calculations in the model space consistingof valence orbits 1p3/2 , 0f5/2 , 1p1/2 and 0g9/2 , assuming an inert 56 Ni core (f5pg9 shell). It can be regarded
as a first step for future extensions to the pf+sdg model
space. We have carried out the similar iterative fitting calculations as in the case of the the pf shell2) .
Starting from a microscopic interaction (renormalized
G matrix)3) based on a realistic nucleon-nucleon potential, we varied 45 linear combinations of Hamiltonian parameters (133 two-body matrix elements andfour single-particle energies) by a least-squares fit to
400 experimental binding and excitation energy dataout of 87 nuclei with masses A=63-96. In the latest
iteration, we attained an rms error of 185 keV.
As an application of this interaction, we have evaluated the nuclear matrix element of double β decay
for 76 Ge and 82 Se, focusing on the two-neutrino mode.
Shell-model calculations were carried out in the conventional way using the code MSHELL.4) For these
nuclei, the double-β-decay lifetime was measured experimentally, which is related to the nuclear matrix(2ν)
elements MGT . We can compare the experimental
values with our shell-model results, which are calculated according to the following expression:
(2ν)

MGT =

+
+
+
X h0+
f k TGT− k 1m ih1m k TGT− k 0i im+
12 Qββ + Ex (1m ) − E0

∗1
∗2
∗3
∗4

(2ν)

Table 1. Comparison of the nuclear matrix element MGT(MeV−1 ) between the experimental data and the shellmodel calculations.
76

8)

Exp.
Cal. q=0.6, Ex (1+1 )cal.
Cal. q=0.6, Ex (1+1 )exp.
Cal. q=1, Ex (1+)
1 cal.
Cal. q=1, Ex (1+1 )exp.

,where E0 stands for the mass difference between theparent and intermediate nuclei. Since this matrix element depends on both the initial- and the final-state
wave functions as well as the Gamow-Teller strength†

distribution in the intermediate 1+ states, it provides
us with a stringent test of the theoretical model.
In usual shell-model
P calculations, the Gamow-Teller
operator TGT− = k σk τk− is multiplied by a “quenching” factor q to obtain a reasonable agreement with theexperimental data. This factor depends on the adopted
model space, and one can find standard values in theliterature: q=0.82 for the p shell5) , 0.77 for the sd
shell6) and 0.74 for the pf shell.7) Thus, we first estimated a suitable quenching factor in the present f5pg9
shell by carrying out a fitting calculation to the available experimental data for the Gamow-Teller β decay
among low-lying states. As a result, we obtained thevalue q = 0.6, which is much smaller than that forother model spaces mentioned above.
(2ν)
For the evaluation of MGT , we need the excitationenergies of the intermediate 1+ states. Experimentally, the excitation energy of the lowest 1+ state is
0.044 MeV (0.075 MeV) in 76 As (82 Br), while our shellmodel gives 0.286 MeV (0.470 MeV) for this energy.
We consider two cases: (1) the shell-model excitationenergies are used as they are, and (2) the shell-modelenergies of all the intermediate states are shifted commonly so as to reproduce the experimental value ofEx (1+
1 ). The results are summarized in Table 1. It
can be seen that the shell model with the quenching
factor q = 0.6 reasonably accurately reproduces theexperimental values for both 76 Ge and 82 Se.

Condensed from the article in J. Physics: Conf. Series 49,
45 (2006).
Center for Mathematical Sciences, University of Aizu
Department of Physics and Center for Nuclear Studies, University of Tokyo
Institute of Natural Sciences, Senshu University
Department of Physics and Center of Mathematics for Applications, University of OsloGe
+0.0060.127−0.004
0.111
0.120
0.308
0.333

82

Se
+0.0020.090−0.010
0.106
0.124
0.295
0.345

References
1) T. Otsuka et al.: Phys. Rev. Lett. 81, 1588 (1998).
2) M. Honma et al.: Phys. Rev. C 65, 061301(R) (2002);
Phys. Rev. C 69, 034335 (2004).
3) M. Hjorth-Jensen et al.: Phys. Rep. 261, 125 (1995).
4) T. Mizusaki: RIKEN Accel. Prog. Rep. 33, 14 (2000).
5) W. T. Chou et al.: Phys. Rev. C 47, 163 (1993).
6) B. H. Wildenthal et al.: Phys. Rev. C 28, 1343 (1983).
7) G. Martinez-Pinedo et al.: Phys. Rev. C 53, R2602(1996).
8) H. Ejiri : Phys. Rep. 338, 265 (2000).

- 52 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Rotational motion in weakly bound superﬂuid nuclei
M. Yamagami and Y. R. Shimizu∗1[Neutron-rich nuclei, nuclear structure, collective motion]=B = 2∑ |hkk 0 |Jx | HF Bi|2
Ek + Ek0

k<k0

.

(1)

2.0

Mg
1.5

HFB
BCS

=0.3

WS

Rigid body

1.0+

E (2 )The quasi-particle (QP) energies Ek , the Hartree-FockBogoliubov (HFB) ground state |HF Bi and the twoQP states |kk 0 i are obtained by the HFB calculation in
two dimensional polar lattice space. This study is theﬁrst attempt to evaluate the moment of inertia thatfully takes into account the pairing correlation involving weakly bound and continuum states. As is wellknown for stable nuclei, strong pairing correlation reduces the value of =B 1) . On the other hand, the matrix
elements in the numerator of Eq. 1 can be large when
spatially extended weakly bound and continuum states
are involved. This eﬀect can enhance the moment ofinertia2) .
In Fig. 1, the neutron pairing gaps in 24−40 Mg obtained by HFB calculations are shown. The WoodsSaxon potential with the standard parameterization1)
and the quadrupole deformation parameter βW S = 0.3
is utilized for the Hartree-Fock mean ﬁeld. On theother hand, the pairing potential is self-consistently derived from the surface-type contact interaction. In the
HFB calculations, not only bound and resonant states
but also non-resonant continuum states are taken into
account. For comparison, the neutron pairing gaps ob-

tained by the BCS approximation are also shown. In
the BCS approach, non-resonant continuum states areomitted from the model space. Within the HFB calculations, the pairing gaps in 30−40 Mg are almost constant at around 2 MeV. On the other hand, the BCS
pairing gaps start to deviate from the HFB values at
32
Mg with the neutron chemical potential λn = ¡3.7
MeV, and they decrease while approaching the neutron drip-line nucleus 40 Mg. The role of non-resonant
continuum states is obvious. Moreover, we found that
non-resonant continuum states with unexpectedly highangular momenta of jz ≥ 13/2 must be included in thecalculations. This strong angular correlation of neutron pairs implies dineutron correlation.
The excitation energies of the rotational 2+ states in30−40
Mg are shown in Fig. 2. The energies are calculated as E(I) = h̄2 I(I + 1)/2=B . Results obtained by
HFB and BCS calculations as well as by the rigid-bodyestimation are shown. For the HFB approach, the 2+energies change smoothly approaching 40 Mg, whereas
the BCS energies decrease and approach the rigid-bodyvalues. This is due to the collapse of the pairing correlation around 40 Mg in the BCS approximation. Therefore, the systematic studies of the excitation energies
and the B(E2) values of the ﬁrst 2+ states can be agood indicator in the investigation of the pairing correlation in weakly bound nuclei. Namely, if the 2+ states
have high excitation energies in spite of large B(E2)values, it may imply dineutron pairing.

[MeV]

We studied rotational excitation in neutron-rich Mg
isotopes. Because the rotational moment of inertia
strongly reﬂects the properties of many-body correlations, particularly the pairing correlation, it is expected to be a good measure of the unique correlations
in weakly bound nuclei. The moment of inertia =B iscalculated by the Belyaev formula1) ,

3.0

Mg

[MeV]

2.5

n

0.5

0.0
32

=0.3

2.0

34

36

38

40

WS

Mass number

1.5

Fig. 2. Excitation energies of the rotational 2+ states inneutron rich Mg isotopes. Results obtained by HFB andBCS calculations as well as by the rigid-body estimation
are shown.

1.0
HFB
BCS

0.5

0.0
24

26

28

30

32

34

36

38

40

Mass number

Fig. 1. Neutron pairing gaps in neutron rich Mg isotopes.
Results obtained by the HFB and BCS calculations areshown.
∗1

References
1) A. Bohr and B. R. Mottelson: Nuclear Structure, Vol.
1 (Benjamin, New York, 1969).
2) M. Yamagami and Y. R. Shimizu: in preparation.

Department of Physics, Kyushu University- 53 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Configuration mixing calculation for complete low-lying spectra withthe mean-field Hamiltonian†
S. Shinohara,∗1 H. Ohta,∗2 T. Nakatsukasa,∗1,∗3 K. Yabana∗1,∗3[NUCLEAR STRUCTURE]

First, many SD’s are stochastically generated, thenthey are evolved in imaginary time to remove all thehigh-energy components [Step (1)]. The imaginarytime evolution eventually leads to a Hartree-Fock (HF)
state, but we store several (or a few) SD’s before reaching the HF minimum. This process is repeated until
we obtain N linearly independet SD’s (N ∼ 50).
The selected SD’s form a basis set, {|Φn i; n =1, ¢ ¢ ¢ , N }.
We then make parity and angular†
∗1
∗2
∗3

Condensed from the article submitted to Phys. Rev. C(preprint: nucl-th/0607004)
Institute of Physics, University of Tsukuba
Sumitomo Chemical Co. Ltd.
Center for Computational Sciences, University of Tsukuba- 54 -

Here, Ĥ is the many-body Hamiltonian with effective
interaction, P̂ ± is the parity projection operator, andJP̂KK
0 is the angular-momentum projection operator.
Finally, we solve the following generalized eigenvalue
problem [Step (3)].
X J(±)J(±)(HnK,n0 K 0 ¡ E J(±) NnK,n0 K 0 )gn0 K 0 = 0.
(2)
n0 K 0Single-particle wave functions in each SD are represented in the three-dimensional (3D) Cartesian coordinate space without any symmetry restriction.
To test our theory, we apply the method to light
N = Z even-even nuclei, using the simplified meanfield Hamiltonian, the so-called BKN force2) . Resultsfor 12 C are shown in Fig. 1. The calculation produces
the ground state rotational band, but its moment ofinertia is larger than the observed values. This is due
to simplicity of the BKN interaction that does not include the LS interaction. In the negative parity, ourcalculation produces 3− state in the lowest energy, also
1− and 2− states at low excitation energies. These are
qualitatively in agreement with experiments. In thepositive parity excited states, the calculation indicates
two 0+ states around 10 and 12 MeV. These may correspond to the measured states around 8 and 10 MeV.
Studies adopting a more realistic Skyrme interaction
are currently under progress.
16

16

14

14

12

12

10

Ex [MeV](1) Generation and selection of Slater determinants(SD’s) important for ground and low-lying excited states.
(2) Parity and angular-momentum projection.
(3) Configuration mixing (diagonalization of the
Hamiltonian).

momentum projection for each SD [Step (2)]. The
Hamiltonian and the norm kernels for the fixed parity (π = ±) and angular-momentum (J, K), where K
indicates its body-fixed component, are given by
(
)
½
¾
J(±)
HnK,n0 K 0
H
J
=
hΦ
|
P̂ ± P̂KK(1)
0 |Φn0 i.
nJ(±)
1
NnK,n0 K 0

Ex [MeV]One of the goals in the microscopic nuclear manybody theory is the ab-initio nuclear structure calculation starting with a fixed Hamiltonian1) . However,
the ab-initio calculations are still limited to nuclei withmass number less than around twelve and to the lowest
energy state for each parity and angular momentum.
Systematic description of ground and excited states innuclei in a wide mass region requires development of a
new computational approach.
One of difficulties of the nuclear many-body problem
is due to the strong short-range correlation. This forbids a naive mean-field approach using the bare NN interaction. In order to overcome this difficulty, effective
NN interactions have been extensively developed inhistory of the nuclear theory. Namely, the short-range
behavior of two-body correlation is effectively renormalized in the interaction. Then, nuclear many-bodywave functions should take account of long-range correlations only. Most of microscopic nuclear structure
models adopt the effective interactions; e.g., nuclear
mean-field models, shell models, cluster models, etc.
The success of these models indicates that a variety of
low-lying modes of excitation are governed by nothing
but the long-range correlations. In the present study,
we aim for developing a new method to treat the wholecorrelation of long range beyond the mean field, utilizing the effective interaction for the mean-field models.
Our method consists of three steps;

8
6
4

(2-)
+

(0 )

(2+)

8
6
4

2
0

10

(2+)

cal
- - - - - - 0+ 1+ 2+ 3+ 4+ 5+ 6+ 0 1 2 3 4 5 6
Jπ

2
0

exp
- - - - - - 0+ 1+ 2+ 3+ 4+ 5+ 6+ 0 1 2 3 4 5 6JπFig. 1. Calculated and experimental spectra for 12 C.

References
1) B. S. Pudliner, et al, Phys. Rev. Lett. 74, 4396 (1995).
2) P. Bonche, S. Koonin, and J. W. Negele, Phys. Rev. C
13, 1226 (1976).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Quadrupole-coupling model for doublet bands in doubly odd nuclei†
N. Yoshinaga∗1 and K. Higashiyama∗2[Nuclear structure, quadrupole coupling model, chopsticks conﬁgurations]|Φ(RL; I)⟩ = [|R⟩ ⊗ |jν jπ ; L⟩]

(I)

,

(1)

where I is the total spin. The model Hamiltonian
employed in the present calculation consists of the

5

21

134

La

Yrare

Yrast
20

E (MeV)

17

+

17
16

15

Yrare

11

15

14
13

expt.

+

16

+

14

17

+

11

+

10

+

18

+

16

+

+

+

14
13

12

9

19

+

+

+

+

+

+

12

+

10

+

+

12

9

QCM

+

8

11

10

+

+

8

Fig. 1. Experimental energy levels of 134 La (expt.) compared with those of QCM calculation.
†
∗1
∗2

2

10

0
11

13

15

17

19

I (h)

Fig. 2. Comparison of ratios B(M 1; I → I − 1)/B(E2; I →I − 2) in QCM with experimental data (expt.).

Hamiltonian of the collective core and the quadrupolequadrupole interactions between the collective core,neutron hole, and proton particle.
Figure 1 shows the comparison of the theoretical energy levels of the QCM with the experimental data for134
La. Concerning the yrast states, the calculated energy levels are in good agreement with the experimental levels. There is no experimental evidence for the 8+
1
state, but the QCM calculation predicts the 8+
1 statenear the 9+
1 state. For the yrare band, our theoreticalresult provides a clear description of the energy levels,
although only four levels are observed experimentally.
Figure 2 shows the comparison of the theoreticalratios B(M 1; I → I − 1)/B(E2; I → I − 2) for the
yrast states with the experimental values. The largeamplitude staggering of the B(M 1)/B(E2) ratios obtained in theory is in good agreement with experimental data, except for the 16+
1 state.
By analyzing the QCM wave functions, it turns outthat the even-odd staggering of the B(M 1)/B(E2) ratios occurs only when the coupling of the collective
core and particles is weak, and that the staggering is
caused by a chopsticks motion of two angular momentaof the neutron hole and proton particle. This result is
consistent with the previous PTSM calculations1–3) .
References

+

+

9

QCM
expt.

20

+

+

+

0

18

+

+

20
+

+

+

13

+

11

+

15

+

12

21

+

+

+

(14 )
13

+

+

+

3

1

20
19

18

2

Yrast

+

+

19

4

+

30

B ( M1 ) B ( E2 ) [( m N eb ) ]The yrast and yrare states based on the νh11/2 ⊗πh11/2 conﬁguration in doubly odd nuclei with mass
number A ∼ 130 have been studied using the pairtruncated shell model (PTSM)1–3) . The model accurately reproduces the experimental energy levels andratios B(M 1; I → I − 1)/B(E2; I → I − 2) for the
yrast states. Through the analysis of PTSM wave functions, it is found that the main structure of the yrast
and yrare states is described in terms of the weak coupling of the chopsticks conﬁgurations, which represent
two angular momenta of the unpaired neutron and unpaired proton, to the multiphonon excitations of theeven-even part of the nucleus.
To conﬁrm the structure, we have recently proposed
a quadrupole-coupling model (QCM). In the model, asystem of one-neutron hole in the orbital jν and oneproton particle in the orbital jπ is speciﬁed as the state|jν jπ ; L⟩, where L is the angular momentum of theparticle-hole state. The collective-core state is denoted
as |R⟩, where R indicates the angular momentum of thecore state. Then, the total wave function of any doubly
odd nucleus is written as a product of the collectivecore state and the particle-hole state,

1) K. Higashiyama and N. Yoshinaga: Prog. Theor. Phys.
113, 1139 (2005).
2) K. Higashiyama, N. Yoshinaga, and K. Tanabe: Phys.
Rev. C 72, 024315 (2005).
3) N. Yoshinaga and K. Higashiyama: J. Phys. G 31,
S1455 (2005).

Condensed from the article in Eur. Phys. J. A 30, 343 (2006)
Department of Physics, Saitama University
Department of Physics, Chiba Institute of Technology- 55 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Tilted-axis rotation and wobbling motion on 3D-CHFB states
Y. Hashimoto,∗1 T. Horibata∗2[3D-CHFB, tilted-axis rotation, generator coordinate method]¡∑]λτ N̂τ |Φ(ψ)i = 0,(1)

τ =p,nwhere the quantities µk , ξk and λτ are Lagrange multipliers used to satisfy the constraints with respect tothe angular momentum and number constraints. B̂kare the three oﬀ-diagonal components of the massquadrupole tensor in the Cartesian coordinate representation.5)
In Ref. [5], it was suggested that there is an extremum point along the tilt angle, which is measured
from the x-axis to the z-axis (symmetry axis). We
∗1
∗2

-10

0.3

amplitude (S)

0.25

-15
0.2

diagonal (S)

-20

0.1

0.05

-30

amplitude (G)

0

-35
-0.05

-40

-0.1

diagonal (G)-45

GCM amplitude

0.15

-25

-0.15

0

10

20

30

40

50

60

70

80

90

tilt angle (degree)

Fig. 1. Amplitude of the GCM solution with the lowest
eigenvalue (solid curve). Broken curves denote the diagonal elements of the Hamiltonian kernel.

References

3 (
[
)
∑
δhΦ(ψ)| Ĥ ¡µk Jˆk + ξk B̂kk=1

take the tilt angle ψ as the generator coordinate in the
GCM calculation. As the space of states, we take into
account the states on the g-branch and s-branch in the
3D-CHFB calculations.
In Fig. 1, we show the GCM amplitude of the solution of the GCM equation with the lowest eigenenergy
for angular momentum J = 18 in the case of osmium
182
Os. The diagonal elements (DEs) of the Hamiltonian kernel are also shown in the ﬁgure. There is awide dip along the DE of the s-branch. There is also a”well” with almost the same depth as the s-branch dip
along the DE of the g-branch7) . The strength of theamplitude is separated roughly into two parts. We expect a coupling eﬀect between the wobbling motion on
the g-branch around the point ψ = 0◦ and the TAR
motion in the dip on the s-branch around ψ = 40◦ .
Analyses of the coupling mechanism are in progress.

diagonal element (MeV)

The rotational motion of a nucleus is due to thecollective motion of the nucleons and is regarded asa macroscopic manifestation of the microscopic quantum eﬀects that prevail in the nucleus. When the axial symmetry is lost in the shape of the nuclear meanﬁeld, a general type of rotational motion occurs, inwhich the rotational axis is not parallel with the principal axis (PA) with the largest moment of inertia but
ﬂuctuates around the PA1,2) . This type of rotationalmotion is called wobbling motion. From a theoreticalpoint of view, a much more general type of rotation
is expected, where the rotational axis is located awayfrom any of the principal axes3,4) . This is called tiltedaxis rotation (TAR)5) . The three-dimensional cranking model plays a central role in the study of wobbling
motion and TAR. To clarify the relations among the
PA rotations, the wobbling motion and the TAR, wecarried out three-dimensional cranked Hartree-FockBogoliubov (3D-CHFB) calculations. Making use of
the 3D-CHFB solutions, we performed calculations by
the generator coordinate method (GCM) to include thequantum mechanical ﬂuctuations around the meanﬁeld solutions.
The model Hamiltonian used in the present calculation is the pairing plus quadrupole (P+QQ), as is used
in Ref. [5]. The parameters in the model Hamiltonian are the interaction strengths for the quadrupolequadrupole and the pairing interactions, whose values
are the same as those used in the previous calculations
in Ref. [6].
The wave function |Φ(ψ)i for the tilt angle ψ is obtained by solving the 3D-CHFB equation,

1) A. Bohr and B. R. Mottelson: Nuclear Structure, Vol.II(Benjamin, Reading, MA, 1975).
2) S. Frauendorf: Rev. Mod. Phys. 73, 463 (2001).
3) A. K. Kerman and N. Onishi: Nucl. Phys. A361, 179(1981).
4) N. Onishi: Nucl. Phys. A456, 279 (1986).
5) T. Horibata and N. Onishi: Nucl. Phys. A596, 251(1996).
6) T. Horibata, M. Oi, N. Onishi, and A. Ansari: Nucl.
Phys. A646, 277 (1999); A651, 435 (1999).
7) Y. Hashimoto and T. Horibata: Phys. Rev. C74, 017301(2006).

Graduate School of Pure and Applied Sciences,
University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
Department of Software and Information Technology,
Aomori University, Aomori, Aomori 030-0943, Japan- 56 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Thermal pairing in Richardson model∗
N. Dinh Dang][
NUCLEAR STRUCTURE, thermal ﬂuctuations, pairing, superﬂuid-normal phase transition, BCS theory, Richardson model

∗

(a)

Ω=Ν

3 4 5

10

(b)

Ω = Ν+1∆ (MeV)

1
0.8
0.6
0.4
0.2
0
0.5

1

Ν = 14

1.2∆ (MeV)Inﬁnite systems undergo a sharp phase transition
from the superﬂuid phase to the normal- ﬂuid one at
ﬁnite temperature. This phase transition is a secondorder one as it is marked by a collapse of the pairingcorrelations (pairing gap), and a near divergence of theheat capacity at a critical temperature Tc .
The application of the BCS theory and its generalization, the Hartree-Fock-Bogoliubov theory , to ﬁnite
Fermi systems paved the way to study the superﬂuidnormal (SN) phase transition in nuclei at ﬁnite temperature T . Soon it has been realized, however, thatthe BCS and HFB theories ignore a number of quantal
and thermodynamic ﬂuctuations, which become large
in small systems due to their ﬁniteness. Although it
has been shown that thermal ﬂuctuations in the pairing
ﬁeld wash out the second-order SN phase transition, it
was unclear about the origin of these ﬂuctuations. In
the recently proposed modiﬁed-BCS (MBCS) theory,and its generalization, the modiﬁed-HFB (MHFB) theory1) , it has been shown for the ﬁrst time that it is theﬂuctuations of quasiparticle number that smooth out
the sharp SN phase transition and lead to the nonvanishing thermal pairing in ﬁnite systems.
The present work tests the validity of the MBCS theory by applying it to the Richardson model for pairingwith a level distance of 1 MeV at various values forthe number of levels Ω and particles N . It is shownthat the limitation of the conﬁguration space sets a
limiting temperature TM up to which the MBCS canbe applied. Enlarging the space in the half-ﬁlled case(Ω = N ) by one valence level (Ω = N + 1) extends
TM to a much higher temperature so that the predictions by the MBCS can be compared directly withthe exact results up to T ≤ 4 - 5 MeV even for small
N . The MBCS gap does not collapse, but decreases
monotonously with increasing T [Fig. 1]. The totalenergy and heat capacity predicted by the MBCS arecloser to the exact results than those predicted by the
BCS, especially in the region of the SN phase transition. The discontinuity in the BCS heat capacity at the
BCS phase-transition temperature Tc is smoothed out
within the MBCS, especially for small N, showing thedisappearance of superﬂuid-normal phase transition invery light systems. With increasing N the peak at Tc
in the heat capacity becomes more pronounced, showing a phase-transition-like behavior in heavy systems.

12

2

20

10

0.8

8
6

0.4
0
0

0.5

1

1.5
T (MeV)

2

2.5

3

Fig. 1. (a): Pairing gaps for Ω = N as functions of temperature. The dotted line denotes the BCS gap obtainedat N = 100. The solid lines represent the MBCS gaps
obtained at N = 6, 8, 10, 12, 14, 16, 18, 20, 30, 40,
50, 60, 70, 80, 90 and 100, where a solid line, which isextended to a larger TM , corresponds to a larger a large
value of N . The dashed line at N = 6 shows the partof the MBCS gap, which increases with T due to thelimitation of the conﬁguration space. (b): Pairing gaps
within BCS (dotted lines) and MBCS (solid lines) forΩ = N + 1 as functions of temperature at N ≤ 14, asshown atop the lines (G = 0.4 MeV).

References
1)

N. Dinh Dang and V. Zelevinsky, Phys. Rev. C 64,
064319 (2001); N. Dinh Dang and A. Arima, Phys.
Rev. C 67, 014304 (2003); N. Dinh Dang and A. Arima,
Phys. Rev. C 68, 014318 (2003).

Condensed from Nucl. Phys. A 784, 147 (2007).

- 57 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Consistency of particle-particle random-phase approximation
and renormalization∗
N. Dinh Dang[]
NUCLEAR STRUCTURE, particle-particle RPA, self-consistent RPA, two-particle separation energy.
The random-phase approximation (RPA) has been
widely used in the theoretical study of nuclei within
the valley of β-stability. Its success is mainly basedon the use of the quasiboson approximation (QBA),
which considers fermion pairs as boson operators, justneglecting the Pauli principle between them. As a result, the linear equations (RPA equations), were derived, which reveal the physics of collective excitations
generated by the RPA boson-like modes. The simplicity of the RPA equations allows a feasible treatmentof a number of many-body problems. However, thisapproach breaks down at a certain critical value of theinteraction’s parameter, where the RPA yields imaginary solutions. The reason of this well-known RPA
instability is the violation of Pauli principle within the
QBA.
In β-stable medium and heavy nuclei, the QBA is agood approximation, and the RPA is a very powerfultool for the description of several important quantities
such as the ground-state and excited-state energies,
electro-magnetic transition probabilities and their distribution, transition densities, etc. However, with reducing the particle number, the concept of collective
excitations, which are described by the RPA modes,
becomes less and less ﬁrm. The ground-state correlations (GSC) which are left beyond the RPA become
stronger in light systems. This feature makes the validity of the QBA, and therefore of the RPA itself,
questionable in the systems with small particle numbers.
Several approaches were developed to take into account the GSC beyond RPA in a simple way suchas to restore the Pauli principle among the fermion
pairs, from which the RPA operators are constructed.
The popular one, known as the renormalized RPA(RRPA)1) includes the expectation value over the
ground state of the diagonal elements of the commutator between two fermion-pair operators, neglected in
the QBA. In this way the Pauli principle is approximately taken care of. The inclusion of GSC beyond
RPA within the RRPA eventually renormalizes the interaction in such a way that the collapse of RPA isavoided, and the RRPA has solutions at any value ofthe interaction’s parameter. This scheme has beentested in several exactly solvable schematic models
such as the Lipkin model for ph RRPA, the SO(8)model for the renormalized quasiparticle RPA, and the∗Condensed from Phys. Rev. C 74, 024318 (2006).

- 58 -

Richardson model for the pp RRPA and self-consistent
RPA (SCRPA)2) . The results of these studies showedthat the diﬀerence between the energies of the ﬁrst
excited state given by the pp RPA, pp RRPA, andSCRPA increases noticeably with increasing the interaction parameter and/or decreasing the particle number. The SCRPA solutions are the closest ones to theexact solutions. These results raise a serious questionof the applicability of the RPA to the calculations forrealistic light-neutron rich nuclei. As a matter of fact,a close agreement between the RPA results and theexperimental data for light neutron-rich nuclei can beconsidered really reasonable if the corrections due to
GSC beyond RPA are negligible, which justify the validity of the QBA. In the opposite case such agreement
may be even illusory.
This concern is the motivation of the present work,whose goal is to test the consistency of the pp RPA
and its renormalizations, the pp RRPA and SCRPA, at
diﬀerent particle numbers as the interaction strength
varies. The consistency condition is tested making useof the Richardson model of pairing. The two-particle
separation energy is calculated in two ways, namely
as the energy of the ﬁrst addition mode, which adds
two particles to a core with N particles, and as theenergy of the ﬁrst removal mode, which removes twoparticles from the N + 2 particle system to get back tothe same N -particle core. The consistency conditionis satisﬁed when the two ways of calculations give thesame result. It is found that the results obtained inthese two ways of calculations are close to each other
only at large values of particle number N and/or smallinteraction strength. At N ≤ 10 for a given valueof the interaction strength, the discrepancy between
the results obtained in two ways of calculations within
the SCRPA is much smaller than those given by the
RPA and RRPA. Therefore, it is quite important to include the eﬀects of GSC beyond RPA in light systems.
Among the approaches considered here, the most consistent one turns out to be the SCRPA.
References
1)

2)

K. Hara, Prog. Theor. Phys. 32, 88 (1964), K. Ikeda,
T. Udagawa, and H. Yamamura, Prof. Theor. Phys.
33, 22 (1965); D.J. Rowe, Phys. Rev. 175, 1283 (1968);
F. Catara, N.D. Dang, and M. Sambataro, Nucl. Phys.
A 579, 1 (1994).
J. Dukelsky and P. Schuck, Phys. Let. B464, 164(1999); N. Dinh Dang, Phys. Rev. C 71, 024302 (2005).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Self-Consistent Quasiparticle RPA for Multi-Level Pairing Model
N. Quang Hung and N. Dinh Dang
[Nuclear structure, random phase approximation, multi-level pairing model]
The random-phase approximation (RPA), which includes correlations in the ground state, provides asimple theory of excited states of the nucleus. However, the RPA equation breaks down at a certain
value of interaction strength where it yields imaginary
eigenvalues because it neglects the Pauli principle between fermion pairs in the quasi-boson approximation(QBA). The RPA theory therefore needs to be extended to correct this deficiency.
The self-consistent RPA (SCRPA)1) is one of theextensions of RPA. It has been applied to the exactly
solvable multi-level pairing model in the critical region and gives a good agreement with exact results forground-state energy and the low-lying part of the spectrum.
Recently, the SCRPA was developed for the superfluid region by a theory called the self-consistent quasiparticle RPA (SCQRPA). The SCQRPA was applied
for the first time for the description of superfluid Fermi
systems2) where a set of SCQRPA equations was solved
analytically within a two-level pairing model.
In this work, the SCQRPA theory is applied for
multi-level pairing model, the so-called picket-fence
model, which is an exactly solvable model extensively
employed in nuclear physics to test many-body approximations. This model consists of Ω doubly-foldequidistant levels interacting via a pairing force withparameter G. The model Hamiltonian is given as:
Ω
Ω
X
X
H=
(²j − λ)Nj − G
Pj+ Pj 0 ,

j

j

+

jj 0

jj 0

gj (j )(A+
j 0 Nj + Nj Aj 0 )+hjj 0 (A+j Aj 0 + Aj 0 Aj ) +

X

j 00

X
1

djj 00 < A+
j 00 Aj >< Dj >
j 00

X
− 2
hjj 00 < Aj 00 Aj > δjj 0−

j 00+ djj 0p

< Dj >< Dj 0 >< A+
j Aj 0 >+ 8qjj 0 p< Dj >< Dj 0 >Bjj 0 = −2 hjj 0 +

+ 2

X

(4)
,





X
1

djj 00 < Aj 00 Aj >< Dj >j 00
 δjj 0
hjj 00 < A+
j 00 Aj >< Dj >< Dj 0 >+ 2hjj 0 p< Dj >< Dj 0 >< Aj Aj 0 >+ 8qjj 0 p,< Dj >< Dj 0 >

(1)

0

jj 0

X



j 00

+
where Nj = a+j aj + a−j a−j is the particle-number op++ +erator, and Pi = aj a−j , Pj = (Pj+ )+ are pairing operators. In the SCQRPA, by using the Bogolyubovtransformation from particle operators a+
j and aj to+quasi-particle ones αj and αj , the Hamiltonian (1) istransformed into:
X
X
X
H = a+
bj Nj +
cj A+
djj 0 A+j Aj +
j Aj 0+where the SCQRPA sub-matrices are given as:
X
Ajj 0 = 2 bj + 2qjj 0 + 2
qjj 00 < (1 − Dj 00 ) >j,j 0 =1

j=1

X

vj and the single particle energies ²j .
The SCQRPA equations are given in the matrix form
as:
µ
¶µ
¶
µ
¶
A B
X
X
=ω
,
(3)
B A
Y
−Y

qjj 0 Nj Nj 0 , (2)jj 0with the quasiparticle number operator Nj =+αj+ αj + α−j
α−j and the quasiparticle pairing opera+++
tors Aj = αj+ α−j
and Aj = (A+j ) . The coefficients0a, bj , cj , djj 0 , gj (j ), hjj 0 , qjj 0 are given in terms of thecoefficients of the Bogolyubov transformation uj and(5)where < Dj >= 1− < Nj > is the ground-state correlation factor. The expectation values < A+
j Aj 0 > and< Aj Aj 0 > are given in terms of amplitudes Xjν andYjν .
The SCQRPA equations are solved numerically using the FORTRAN IMSL Library by Visual Numerics
on the RIKEN Super Combined Cluster (RSCC) System. We hope to improve the description of superfluid
Fermi systems using this SCQRPA for multi-level pairing model.
References
1) P. Schuck, Z. Phys. 241, 395 (1971); P. Schuck and S.
Ethofer, Nucl. Phys. A212, 269 (1973); J.Dukelsky and
P. Schuck, Phys. Lett. B 464, 164 (1999)
2) A. Rabhi, R. Bennaceur, G. Chanfray, and P. Schuck,
Phys. Rev. C66, 064315(2002)- 59 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Formula for proton-nucleus reaction cross section at intermediate
energies and its application†
K. Iida,∗1 A. Kohama, and K. Oyamatsu∗2[Nuclear reaction, reaction cross section, nuclear radius, unstable nuclei]
Nuclear size and mass are fundamental quantities
characterizing the bulk properties of nuclei. In fact,
the saturation of the binding energy and density deduced from systematic data for the masses and charge
radii of stable nuclei reflects the behavior of the equation of state (EoS) of nearly symmetric nuclear matternear the saturation density. The extension of such data
to a more neutron-rich regime opens up an opportunityof probing the EoS of asymmetric nuclear matter.1)
Recently, we have systematically analyzed the proton elastic scattering and reaction cross section data
for stable nuclei at a proton incident energy of Tp ∼800–1000 MeV on the basis of a “black-sphere picture”
of nuclei.2,3) This picture is originally expected to givea decent description of the reaction cross section of any
kind of incident particle that tends to be attenuatedin nuclear interiors. We showed that for proton beams
incident on stable nuclei, the cross section of the black
sphere of radius a (= πa2 ), which was determined byfitting the angle of the first elastic diffraction peak calculated for proton diffraction by a circular black diskof radius, a, to the measured value, is consistent withthe measured reaction cross section.3) This consistency
suggests that the black sphere radius corresponds to areaction radius inside which the reaction with incident
protons occurs. For real nuclei, this radius must be aradius at which the mean free path of incident protons
becomes of the order of penetration length.
In this work, we construct a formula for a protonnucleus total reaction cross section, σR , as a functionof the mass and neutron excess of the target nucleus
and Tp in a way free from any adjustable Tp -dependent
parameter. We deduce the dependence of σR on Tp
from a simple argument involving the proton “optical”
depth within the framework of a black sphere approximation of nuclei, while we describe the neutron excess dependence by introducing the density derivativeof the symmetry energy, L, on the basis of a radius
formula constructed from macroscopic nuclear models.
This parameter is still uncertain, but mainly controls
the saturation density of nuclear matter at nonzero
neutron excess.
We find that, for stable nuclei, this formula remarkably well reproduces the empirical Tp dependence of σR
at Tp = 100–1000 MeV without introducing any ad†∗1∗2

Condensed from the article in nucl-th/0601039 (J. Phys.
Soc. Japan in press).
Department of Materials Science, Kochi University
Department of Media Theories and Production, Aichi
Shukutoku University

justable energy-dependent parameter. This prescription is easily extended to nucleus-nucleus reactions,and an illustrative example is shown in Fig. 1. In addition, we consider the effects of a large neutron excess
typical of unstable nuclei and nuclear deformation on
the reaction cross section.
We thus find out a possible way of examining theeffect of the density dependence of the symmetry energy.
References
1) K. Oyamatsu and K. Iida: Prog. Theor. Phys. 109,631 (2003).
2) A. Kohama, K. Iida, and K. Oyamatsu: Phys. Rev. C
69, 064316 (2004).
3) A. Kohama, K. Iida, and K. Oyamatsu: Phys. Rev. C
72, 024602 (2005).

Fig. 1. 12 C-12 C reaction cross section as function of energy per nucleon. Filled circles indicate empirical data.
Lines indicate the results obtained using our formula inwhich a0 is set to be 2.7 fm (bold), 2.65 fm (lower, thin),2.75 fm (upper, thin), and 1.214A1/3 fm (dashed).The
choice of 2.65–2.75 fm is based on the measured diffraction peak angle in proton elastic scattering.

- 60 1

RIKEN Accel. Prog. Rep. 40 (2007)

More Accurate Estimation of Ground-State Energy and Spin-Zero
Dominance
N. Yoshinaga ∗1 and A. Arima ∗2[Nuclear shell model, Spin-zero dominance]

Ĥ =

2j−1
X

√

i(0)
h
,
2J + 1 GJ A†(J) Ã(J)where dI indicates the dimension of the Hamiltonian
matrix.
Let us estimate the ground-state energy of the
Hamiltonian Ĥ by assuming that it can be expressedin terms of average energy (ĒI ), width (σI {GJ }) andthe number of states (dI ) as(4)

where Φ(dI ) is assumed to depend only on the dimension of the Hamiltonian matrix and to take the formp(5)
Φ(dI ) = a ln dI + b.
Here, the parameters a = 0.99 and b = 0.36 are determined phenomenologically.
We further make an approximation of ground-stateenergy. Now, ground-state energy is approximated as∗1∗2

5 7 9 11 13 15 17 19 21 23 25 27 29 31 33
Fig. 1. P (0)’s of four fermions in single-j shell. The diamonds are obtained by performing 1000 runs of the
TBRE Hamiltonian. The squares are obtained using
the energies obtained by second-order approximationand the triangles, using those obtained by third-orderapproximation.

EI= ĒI −

pa ln dI + b σI − c γI

(6)

where

Then the variance of eigenenergies around the averageenergy (the width squared) is denoted as
h¡
¡
¢2
¢2 i
1
σI {GJ } ≡ Tr Ĥ − ĒI
,
(3)
dI

= ĒI − Φ(dI ) σI {GJ } ,

40
20

(1)

where GJ ’s are two-body interactions between
fermions and are assumed to follow the TBRE¡¢
1
ρ(GJ ) = √ exp −G2J /2 .
(2)
2π

(2)

TBRE
Second order
Third order

60

(3)

J=0,even

EI

80
P(I=0) (%)

The ground states of all even-even nuclei have a zerospin, I = 0, and a positive parity, π = +. The predominance of I π = 0+ ground states was discovered by
Johnson et al. using the two-body random ensemble(TBRE)1) . Since then, many studies have been devoted to understanding and solving this problem fromvarious viewpoints (see Ref. 2 for a recent review).
In our previous studies3) , we obtained a semiempirical formula for evaluating the ground-state energy interms of average energy (centroid), standard deviation(width), and the number of spin I states. On the basisof this formula, we studied the problem of the spinzero ground state (0 g.s.) dominance in the presenceof the TBRE. In this paper, we report a method for amore accurate evaluation of ground-state energy.
To simplify our argument, we take a single j n configuration for fermions. The Hamiltonian used is

·³
´3 ¸
1
.
(γI ) ≡ Tr Ĥ − ĒI
dI
3

(7)

In Fig. 1, we show the P (0)’s of four fermions insingle-j shells. The diamonds are obtained by performing 1000 runs of the TBRE Hamiltonian. The
squares are the results of the present method in termsof second-order approximation (second order). The
triangles are the results of third-order approximation(third order). It is seen that both predictions perfectly
describe the staggering behavior of P (0)’s. A small refinement is obtained using third-order approximation
for ground-state energy.
To summarize, we proposed a new analytical expression for evaluating the ground-state energy of spin I
states. With this simple formula, a remarkably successful description of the spin I ground-state probabilities was obtained in the presence of the TBRE.
References
1) C. W. Johnson, G. F. Bertsch and D. J. Dean: Phys.
Rev. Lett. 80, 2749 (1998).
2) Y. M. Zhao, A. Arima and N. Yoshinaga: Phys. Rept.
400, 1 (2004).
3) N. Yoshinaga, A. Arima and Y. M. Zhao: Phys. Rev. C
73, 017303 (2006), N. Yoshinaga, A. Arima and Y. M.
Zhao: RIKEN accel. Prog. Rep. 39, 24 (2005).

Department of Physics, Saitama University
Science Museum, Japan Science Foundation- 61 -

1

RIKENAccel.
Accel.Prog.
Prog.Rep.
Rep. 40
39(2007)(2006)
RIKEN

Fusion Hindrance Due to One-Body Penetration
at Deep Sub-Barrier Energies for 64 Ni+64 Ni
T. Ichikawa, K. Hagino,∗1 and A. Iwamoto,∗2[Fusion reactions, coupled-channel model, medium-mass nuclei]
In fusion reactions in the medium-mass region suchas 64 Ni+64 Ni, 58 Ni+58 Ni and 64 Ni+89 Y, it has beenfound that experimental fusion cross sections at extremely low incident energies become much lower thanones calculated using the coupled-channel (CC) modelusing the Wood-Saxon potential1) . This steep fall-oﬀ
of experimental fusion cross sections is known as fusion
hindrance. The physical origin of the fusion hindrance
is not yet understood well.
To explain this fusion hindrance, we propose a twostep model based on an adiabatic scheme, in which
the neck formation in a one-body system is taken into
account. This model is used to consider the ﬁssion
like adiabatic potential-energy surface with the neckshape after the colliding nuclei come into contact. This
one-body potential acts as an inner barrier that has
to be overcome to reach the compound state. Thismechanism only works when the incident energies are
below the potential energy at the conﬁguration when
the nuclei come into contact.
Our two-step model consists of the capture process in a two-body potential pocket, which is followedby the penetration of the adiabatic one-body potential to reach a compound state after the nuclei comeinto contact. We describe the former process using
the coupled-channel framework, while the latter is described using the WKB approximation by taking into
account the coordinate-dependent inertia mass. The
fusion cross section in this two-step model isσ(E) =πh̄2 ∑(2ℓ + 1)Tℓ (E)P1bd (E, ℓ),
2µE

(1)

ℓ

where µ and E denote the reduced mass and the incident energy in the center-of-mass system, respectively.
Tℓ denotes the sticking probability in the two-body system, which is calculated with the CC model using thecomputer code CCFULL2) from the inﬁnite separationof the nuclei to the conﬁguration when they come into
contact. P1bd is the penetrability of the composite
system for penetrating the adiabatic one-body barrier
to reach the compound nucleus, which is calculatedusing the WKB approximation taking account of thecoordinate-dependent inertia mass. The inertia massis calculated as the irrotational-ﬂow mass using theWerner-Wheeler approximation.
We apply this two-step model to the fusion reactionof the 64 Ni+64 Ni system. In this work, we employ∗1∗2

Fig. 1. One- and two-body potential energy for 64 Ni+64 Ni
calculated using the KNS model. We assume that theshape conﬁguration in the one-body system is describedby a lemniscatoid parametrization.

the potential energy calculated using the Krappe-NixSierk (KNS) model3) , as shown in Fig. 1. The radiusparameter is adjusted to r0 = 1.204 fm to ﬁt the experimental fusion cross section at high incident energies. In the KNS model, the saturation property is
phenomenologically taken into account. In the onebody system after the two nuclei come into contact,
we assume that the shape conﬁguration is describedby lemniscatoid parametrization4) .
By taking into account the penetration of the adiabatic one-body potential with the neck formation after
the nuclei come into contact, we ﬁnd that the fusioncross section calculated using this model accounts wellfor the experimental data. This result shows that thefusion hindrance can be explained in terms of the extra
barrier in the one-body system. The detailed calculation is now in progress.
References
1) C. L. Jiang et al.: Phys. Rev. C 73, 014613 (2006).
2) K. Hagino et al.: Phys. Commun. 123, 143 (1999).
3) H. J. Krappe et al.: Phys. Rev. C 20, 992 (1979).
4) G. Royer et al.: J. Phys. G8, L159 (1982).

Department of Physics, Tohoku University
Japan Atomic Energy Agency- 62 -

1

RIKEN
Accel.
Prog.
Rep.
(2006)
RIKEN
Accel.
Prog.
Rep.
4039
(2007)

Late-time supernova evolution induced by anisotropic neutrino
radiation and r-process environment†
H. Madokoro and Y. Motizuki[shock waves—hydrodynamics—stars:neutron—supernovae:general—nucleosynthesis]star goes through such a low-Ye region, and moves upward along the polar axis due to global convection.
Note that the expansion velocity of our 2-D model ismuch larger than that of the spherical model. Thus,
we obtained a promising environment as an r-process
site in our 2-D simulation, that is, high entropy andlow Ye values, and a rapid expansion. The r-process
network calculations based on the present supernova
simulations are now in progress.
References
1) T. M. Shimizu et al.: Astrophys. J. 552, 756 (2001).
2) H. Madokoro, T. Shimizu and Y. Motizuki: Astrophys.
J. 592, 1035 (2003).
3) H. Madokoro, T. Shimizu and Y. Motizuki: Publicationof Astronomical Society of Japan 56, 663 (2004).

Fig. 1. Contour plot of entropy distribution with velocity
fields at 2150 ms after shock stall. The maximum valueof entropy reached more than 200 in units of Boltzmann
constant per nucleon.

- 63 -

0.6

Ye

It has been found that multidimensional simulations
are necessary to understand the mechanism underlying core-collapse supernova explosions. We performed
two-dimensional (2-D) simulations with particular attention paid to the role of globally anisotropic neutrino
radiation. Our previous studies1–3) showed that a few
percent of anisotropy markedly increases explosion energy.
We now extend our calculations to the later phaseof explosions (t > 1 sec after bounce) to investigate
the r-process environment. In our previous studies, wemade several assumptions that are valid only under
the conditions of high temperature and high density,
following a common description of core-collapse supernovae. To extend our simulation to the later phase,
we have updated a number of points in our numericalcode. The most important one is that we used exact
expressions of the neutrino-matter interactions, which
can be applied to low-temperature and low-density regions. We have also included the important effect ofinternal shock heating, which is caused by the accretion of matter onto the surface of a protoneutron star.
Our calculations start when a supernova shock wave
is stalled at 150 km from the center of a protoneutronstar. The radius of the proto-neutron star was taken to
be 15 km. We assumed that the neutrino temperatureis 7.8 MeV at the beginning of our simulation, and decays with time. The anisotropy of neutrino radiation,lz /lx , is set to be 3 for the 2-D model.
Figure 1 shows a contour plot of entropy distribution with velocity fields at 2150 ms after the shockstall. We obtain very high values of entropy (morethan 200 in units of Boltzmann constant per nucleon).
This enhancement of entropy is mainly caused by an
improved neutrino heating rate and the effect of internal shock heating. The improved neutrino heating rateaffects the evolution of entropy distribution to a large
extent for late-time evolution. The internal shock heating forms new shock waves, which propagate outwards
and merge into the original shock wave. This increases
matter temperature, and subsequently the value of entropy. We estimated that entropy is enhanced morethan 50 % when the internal shock heating is included.
Figure 2 shows the evolution of the electron-baryon
fraction (Ye ). The evolution is strongly suppressed(∼ 0.02 − 0.03) just above the surface of the protoneutron star. This is because very strong electron captures
onto free protons occur in the vicinity of the surface.
Accreting matter onto the surface of the proto-neutron

0.4

0.2

0

t=0 [ms]
t=150 [ms] (pole)t=150 [ms] (equator)
t=302 [ms] (pole)t=302 [ms] (equator)

1e+02

1e+03

1e+04

r [km]

Fig. 2. Evolution of electron-baryon fraction.

1

RIKEN Accel. Prog. Rep. 40 (2007)

Estimation of the in-medium modification parameters for φ meson†
R. Muto, H. En’yo, M. Naruki, F. Sakuma,∗1 and S. Yokkaichi for the KEK-PS E325 Collaboration†∗1

Condensed from the article in Phys. Rev. Lett. 98(2007),
042501
Department of Physics, Kyoto University- 65 -

2

counts/[6.7MeV/c ]

2

60

C

βγ<1.25

40

150

Cu

50

χ =37
χ2=36

0

2

counts/[6.7MeV/c ]2counts/[6.7MeV/c ]

2

0

C

1.25<βγ<1.75

100

150

χ2=66
2
χ =74

Cu

50

2

2

χ =66
χ2=64

0

2

counts/[6.7MeV/c ]2

1.25<βγ<1.75

100

50

0

βγ<1.25100

20

counts/[6.7MeV/c ]C

1.75<βγ

200

χ =45
χ2=44

Cu

1.75<βγ

300

200

100
100

2

0

χ =45
2
χ =46
0.9

1

1.1

0

1.2
2
[GeV/c ]

χ2=58
2
χ =56
0.9

1

1.1

1.2
2
[GeV/c ]Fig. 1. Best-ﬁt results in cases (i) (solid line) and (ii) (dotted line). The shift parameter k1 and the broadening
parameters k2tot and k2ee are common for the six spectra. The values of χ2 are the sum of the squares of thedeviations over 54 data points in each panel.
(a)

0.05

k1

The KEK-PS E325 experiment was conducted at the
KEK Proton Synchrotron to detect possible in-medium
modiﬁcation of vector mesons. Invariant mass spectraof φ → e+ e− decays were measured in 12-GeV p + A
interactions. Copper and carbon targets were used to
study the nuclear-size dependence. We ﬁtted the mass
spectrum with a resonance shape of φ → e+ e− and aquadratic background curve. A signiﬁcant excess on
the low-mass side of the φ meson peak was observedin the lowest βγ region of φ mesons (βγ < 1.25) withcopper targets1) .
We attempted to reproduce the obtained mass spectra with a Monte-Carlo-type model calculation that
includes the in-medium mass modiﬁcation of the φmesons. We introduced the in-medium modiﬁcation
parameters, k1 , k2tot and k2ee as follows. We assumed the density dependence of the φ meson mass as
mφ (ρ)/mφ (0) = 1 − k1 (ρ/ρ0 ), where ρ0 is the normal
nuclear density2) . For the density dependence of thetottotal width broadening, we assumed Γtot
φ (ρ)/Γφ (0) =
tot
tot
ee
1 + k2 (ρ/ρ0 ); k2 ≥ 0. For Γφ (the partial width foreethe φ → e+ e− decay), we assumed Γeeφ (ρ)/Γφ (0) =ee
1 + k2 (ρ/ρ0 ), and examined the following two cases:
tot(i) the branching ratio Γee
φ /Γφ remains unchanged in
the medium (k2ee = k2tot ), and (ii) Γee
φ does not increasein the medium (k2ee = 0).
We modiﬁed the resonance shape of the φ mesonwith the modiﬁcation parameters k1 , k2tot and k2ee , thenﬁtted again the observed mass spectra with the sameprocedure as before. The best-ﬁt results in both cases
are shown in Fig. 1. The modiﬁcation parameters arecommon to the six spectra. Figure 2 shows the conﬁdence ellipsoids for the variation of χ2 with k1 and k2tot
in cases (i) and (ii). In case (i), the obtained best-ﬁt
tot
parameters are k1 = 0.034+0.006= 2.6+1.8−0.007 , k2
−1.2 , andthe minimum χ2 (χ2min ) is 316.4. In case (ii), the besttot
+5.6
, and
ﬁt parameters are k1 = 0.033+0.011−0.008 , k2 = 022
χmin is 320.8. In both cases, χmin was obtained withparameter k1  0.034, meaning the pole mass of the φmeson decreases by 3.4 % at normal nuclear density.
The χ2min in case (ii) (=320.8) is larger than that incase (i) (=316.4) by 4.4. When we ﬁtted only the Cu
data in the lowest βγ region, where the major discrepancy occurs, case (ii) was rejected at 99% C.L. andthe best-ﬁt parameters of k1 and k2tot do not change,
while case (i) was not rejected. The data thus favor
an increase in Γee
φ by a factor of 3.6 at normal nuclear

counts/[6.7MeV/c ][QCD, chiral symmetry, normal nuclear density, mass modiﬁcation, vector meson]

(b)

0.04
0.03
0.02

Δχ2 = 1Δχ2 = 2Δχ2 = 3

0.01
0

0

2

ee

Δχ2 = 52Δχ = 6tot

k2 = k2
4

6

k2tot

0

2

ee

k2 = 04

6

k2tot

Fig. 2. Conﬁdence ellipsoids for the modiﬁcation parameters k1 and k2tot (a) in case (i) and (b) in case (ii). The
values of Δχ2 in both panels are the diﬀerences fromthe χ2min (= 316.4) at the best-ﬁt point in case (i), whichis shown by the cross in panel (a). The best-ﬁt pointin case (ii) is shown by the closed circle in panel (b),and also in panel (a) since the ordinates are common toboth cases in the parameter space.

density.
In these analyses, we used the excellent cpu powerof CC-J and RSCC at RIKEN. We are grateful for
support from these computing facilities.
References
1) R. Muto et al.: RIKEN Accel. Prog. Rep. 39, 80 (2006).
2) T. Hatsuda and S. H. Lee: Phys. Rev. C 45, R34 (1992).

1

RIKENRIKENAccel.
Accel.Prog.
Prog.Rep.
Rep. 40
39(2007)(2006)

Nuclear mass number dependence of φ-meson production in thee e and K + K − decay channels studied in 12 GeV p + A reactions†+ −F. Sakuma,∗1 H. En’yo, M. Naruki, R. Muto, and S. Yokkaichi for KEK-PS E325 collaboration[φ meson, mass number dependence, e+ e− , K + K − ]

(a)

α

α

we show the estimated values of αφ→e+ e− (βγ) in the
kaon acceptance window as a hatched band; this canbe compared with the measured value of αφ→K + K − .
The difference ∆α in the kaon acceptance is plotted in Fig. 1(d). We expect ∆α to be zero when
Γφ→K + K − /Γφ→e+ e− does not change in the nuclear
medium. Although it is interesting to observe that∆α increases when βγ decreases, ∆α at the lowest βγ
bin is only 0.33 ± 0.17; the average value is 0.14 ±0.12. Therefore, αφ→e+ e− and αφ→K + K − are statistically the same in the measured kinematic region.
To expedite the analysis, we have used CC-J and
RSCC at RIKEN. We would like to thank the staff
members of CC-J and RSCC for their support.

(b)

e+eK+K-

(c)

∆α

βγ
α

In the experiment, KEK-PS E325, we measured
e+ e− and K + K − pairs produced in the 12 GeV p + A
reaction, in order to search for in-medium modification of vector mesons. In the present study, the nuclear mass number dependence of φ-meson production
is compared between the e+ e− and K + K − decay channels to determine whether the ratio of the partial decay width Γφ→K + K − /Γφ→e+ e− depends on the nuclear
size.
The nuclear mass number dependence of the crosssection for particle production is parameterized as
σ (A) = σ0 × Aα for a target nucleus with mass
number A. When the spectral function of the φmeson and/or kaon is modified in a medium andΓφ→K + K − /Γφ→e+ e− changes1) , the ratio of the φmeson yield measured in the e+ e− and K + K − decay
channels, R = Nφ→K + K − /Nφ→e+ e− , becomes dependent on the mass number since a larger number of φmesons are to be modified in a larger nucleus. Consequently, by using two different nuclear targets A1
and A2 , the difference in the α parameter between
φ → e+ e− (αφ→e+ e− ) and φ → K + K − (αφ→K + K − )can be related to R as follows:

rapidity(d)∆α = αφ→K + K − − αφ→e+ e−= ln [R (A1 )/R (A2 )]/ln (A1 /A2 ).
It is important that most of the experimental effects,
which include large systematic errors arising fromtracking efficiency and beam intensity, are canceled in
obtaining α.
In the present article, we report the results of theanalysis of all the data obtained in 2001/2002. In order to observe the nuclear size dependence, we accumulated data using two types of targets: carbon andcopper. A detailed description of the E325 spectrometer can be found elsewhere2) .
The observed α parameters are plotted as functionsof βγ (= p/m) in Fig. 1(a) and as functions of the rapidity (y) and transverse momentum (pT ) in (b) and(c), respectively. Since the e+ e− and K + K − decay
channels cannot be compared directly because of thedifference in the detector acceptance between the e+ e−
and K + K − decay channels, we determined αφ→e+ e−
two-dimensionally on the y-pT plane, under the assumption that αφ→e+ e− is linearly dependent on y andpT , and estimated the values of αφ→e+ e− corresponding to the kaon acceptance windows. In Fig. 1(a),
†
∗1

pT

βγ

Fig. 1. α parameters of φ → e+ e− (closed circles) and
φ → K + K − (open circles) as functions of (a) βγ, (b)rapidity, and (c) pT . The horizontal error bars are
the RMS values of the horizontal bins. The hatchedbands show corrected αφ→e+ e− to be compared with
αφ→K + K − (see text). (d) The differences between
αφ→K + K − and αφ→e+ e− in the kaon acceptance window. The average value and error are also plotted as ahatched band.

References
1) D. Lissauer and E. V. Shuryak: Phys. Lett. B253, 15(1991); P.-Z. Bi and J. Rafelski: Phys. Lett. B262, 485(1991); J. P. Blaizot and R. Mendez Galain: Phys. Lett.
B271, 32 (1991).
2) M. Sekimoto et al.: Nucl. Instrum. and Meth. A516,
390 (2004).

Condensed from the article in Phys.Rev.Lett.98,152302(2007).
Department of Physics, Kyoto University- 66 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Proposed spectrometer for electron pair measurement at J-PARC
50-GeV PS
S. Yokkaichi and K. Ozawa⁄1
We proposed to perform a next-generation experiment to explore the chiral symmetry restoration in
nuclear matter. The experiment is the successor of the
KEK-PS E325 experiment1 , which has been successfully completed recently. We intend to measure electron pairs from the decay of low-mass vector mesons(‰/ω/`) in nuclear matter at the J-PARC2 50-GeV
proton synchrotron (PS) in use of a newly constructed
spectrometer. Our proposal3 was granted a physics
approval in March 2007.
The goal of the proposed experiment is to collect1∼2 ×105 ` mesons in 30 days of operation with comparable (or improved) mass resolution to that achievedby the E325 (∼ 11 MeV/c2 ). The statistics is ∼100
times as high as that of E325. Such data enable us
to discuss whether the origin of the observed spectral
modification is the chiral symmetry restoration or not,by quantitative comparison with many theoretical predictions.
To improve the statistics by a factor of 100, we use
a larger production cross section of ` for a factor of
two, which is brought by the higher incident energy,
a larger acceptance spectrometer for a factor of five,and a beam intensity ten times as high as E325, i.e.,
1 × 1010 pps, for a remained factor of ten.
To cover a larger acceptance and to cope with thehigher interaction rate (107 Hz on target), we must use
new technologies such as a tracker with a Gas Electron Multiplier (GEM) and a Hadron Blind Detector(HBD)4 for electron identification. The schematic figure of the proposed spectrometer is shown in Fig. 1.
To achieve a 10 MeV/c2 mass resolution, 200 „mposition resolution is required, thus a 0.7 mm pitchof strip readout is used for the GEM Tracker. The

beam
return
yoke

coil
pole
piece

LeadGlassCalorimeter

trackers are placed at radii of 200, 400, and 600 mm
from the center of the spectrometer magnet.
The typical expected particle rate is 5 KHz/mm2
for the forwardmost region in the innermost layer of
the tracker, in other words, a point 12◦ apart from thebeam horizontally and 200 mm apart from the centerof the magnet where the target is located. Further, 1
KHz/mm2 is expected even at a point of 60◦ /200 mm.
These values are based on our E325 experience and thefactor of ten is multiplied due to the proposed beam
intensity. For the 4mm(W)×100mm(H) cell of a drift
chamber, the operation is marginal at 60◦ (400 KHz)
and impossible at 12◦ (2 MHz). For the GEM Tracker,
the effective cell size is 0.7 mm(W)×100 mm(H) andthe expected counting rate is 350 KHz at a point of
12◦ /200 mm; thus the tracker is operational.
HBD is a threshold type gas Čerenkov counter,
which uses the CsI photocathode to convert Čerenkov
photons to electrons and the stacked GEM foils for
gas-amplification of electrons. The radiator gas, CF4(index=1.00062), is also used as the amplification gas,thus UV-transparent window to separate an amplification zone from the radiator is not required. The
readout pads are hexagonal with a “diameter” of 32
mm, which corresponds to the size of the photon distribution area from the radiator 500 mm in length. Hit
information is also readout from the last GEM foil ofthe stack and used to trigger electron pairs. The electrode of the last foil is divided in 100 × 100 mm2 areas,
corresponding to the size of the lead glass EM calorimeter located just behind the HBD. A coincidence of the
HBD, EM calorimeter and the last layer of the GEM
Tracker composes an electron candidate. Such fine segmentation of a trigger unit is essential for dropping
accidental coincidences, which is expected as a main
trigger background. Covering such a large acceptancewith a small dead region and such fine segmentation
cannot be achieved with the conventional segmented
gas Čerenkov counter using a PMT readout.
For detector simulation for designing the new spectrometer, RIKEN-CCJ 5 is used.
References

Cherenkov
radiator

TargetCsI +GEM
GEM
Pad chambertrackerFig. 1. Schematic plan view of proposed spectrometer.
⁄11) M. Naruki et al:, Phys. Rev. Lett. 96, 092301 (2006),
and in this report
R. Muto et al:, Phys. Rev. Lett. 98, 042501 (2007), andin this report2) http://j-parc.jp/
3) http://j-parc.jp/NuclPart/Proposal 0606 e.html
4) A. Frankel et al:, Nucl. Instr. Meth. A546, 466 (2005).
5) S. Kametani et al:, in this report.

University of Tokyo- 67 -

1

RIKEN
Accel.
Prog.
Rep.4039(2006)
RIKEN
Accel.
Prog.
Rep.
(2007)

Search for Θ+ via K + p → π + X reaction at KEK-PS E559†
K. Miwa∗1 from the E559 collaboration∗1

Department of Physics, Tohoku University- 68 -in order to select K + p → π + X events and obtained approximately 17,000 and 12,000 reaction events in the
1st and 2nd runs, respectively.
Figure 2 shows the missing-mass spectrum of theK + p → π + X reaction, which is the sum of data in the
1st and 2nd runs. The hatched peak is the expected
spectrum assuming that Θ+ is produced isotropicallyin the center of mass system and the total cross section of the K + p → π + Θ+ reaction is 50 µb. We could
not observe any significant peak structure in the spectrum. Therefore, we derived the upper limit of thecross section (averaged over 0 to 20 degrees in the laboratory frame) to be a very preliminary value of 1.9µb/sr. This limit is much smaller than the theoretical
calculation, which predicts more than 30 µb/sr for thisproduction channel by taking the K 0∗ exchange into
account5) .
References

Counts1) T. Nakano et al., Phys. Rev. Lett. 91, 012002 (2003).
2) K. H. Hicks, Prog. Part. Nucl. Phys. 55, 647 (2005).
3) N. Muramatu et al., presentation at JPS meeting(2006).
4) V. V. Barmin et al., hep-ex/0603017.
5) Y. Oh et al., Phys. Rev. D 69, 074016 (2004).

1600
LH2 Target

1400

Empty Target
Subtraction

1200
1000
800
600
400
200
0
-500 -400 -300 -200 -1000

100 200 300 400 500z(mm)Fig. 1. Vertex distribution of K + p → π + X reaction.

h3

Counts/0.5MeV/c 2

Since the first report giving evidence on the existenceof an exotic baryon Θ+ by the LEPS collaboration1),
many studies from both theoretical and experimental
aspects have been conduced. Recently, however, null
results have been reported from several high-energy experiments, and some of the initial positive evidence wasdenied by the same collaboration with higher statistics2) . Therefore, the situation for the existence of Θ+is controversial. On the other hand, the LEPS and
DIANA collaborations have shown new evidence supporting its existence3)4) . Therefore, confirmation of
the existence (or nonexistence) of Θ+ is urgent andimportant.
We have performed an experiment to search for Θ+
via the K + p → π + X reaction at the K6 beam linewith high missing-mass resolution using the SKS spectrometer at the KEK 12 GeV proton synchrotron. The
experimental periods were about one month from June
2005 (1st run) and two weeks from December 2005
(2nd run). A 125-mm-long liquid hydrogen target wasused. We used a K + beam of 1.2 GeV/c. The typicalintensity was 14k counts during the 2 seconds of spill.
The momentum of each beam particle was analyzed using the K6 beam line spectrometer, of which the resolution is expected to be ∆p/p = 0.047% (FWHM).
Scattered particles were detected using the SKS spectrometer, which covered a forward angle between 0 to
20 degrees, and the acceptance in the laboratory frame
was 0.11 sr. The analysis was performed using RIKENCCJ. Since the missing-mass peak of Σ+ is clearlyreconstructed with the expected resolution using theπ + p → K + Σ+ reaction taken for the calibration, amissing-mass resolution of 2.4 MeV/c2 (FWHM) is expected for Θ+ .
The main background of the measurement is the
3-body decay of K + , such as K + → π + π + π − orK + → π + π 0 π 0 . The rejection of the decay backgroundis essential for Θ+ search. To separate hadronic reactions such as ∆ production from these decay events,
we installed a large acceptance chamber and a range
counter behind the target. The suppression factor forthe decay events by analysis using these detectors is
obtained to be about 98% from a Monte Carlo simulation. The efficiency of this analysis for signal events
is obtained to be about 70%, when we assume that
Θ+ is produced isotropically in the center of mass system. The vertex distribution after the rejection of decay events is shown in Fig. 1 with the distribution of
the empty-target data (hatched histogram) for the 1st
run. The 125 mm liquid hydrogen image is clearly observed. We selected a vertex region of the LH2 target

Entries
Mean
RMS

400 1st run + 2nd run

58955
1.547
0.0299

350
300

y

inar

elim
y Pr

250

Ver

200
150
100
50
0

1.46 1.48

1.5

1.52 1.54 1.56 1.58

1.6

1.62 1.64
2Missing Mass (GeV/c )Fig. 2. Missing-mass spectrum of K + p → π + X reaction.
The hatched spectrum shows the expected spectrum forΘ+ (see text).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Measurement of high-pT Single Electrons from Heavy-Flavor Decays√
in p + p Collisions at s = 200 GeV
Y. Akiba, R. Averbeck,∗1 A. Dion,∗1 F. Kajihara,∗2 H. Themann∗1 for the PHENIX collaboration∗1∗2

StonyBrook University, USA
University of Tokyo- 69-

References

non-photonic/photonic

1) A. Adare et al.: Phys. Rev. Lett. 97, 252002 (2006).
2) M. Cacciari et al.: Phys. Rev. Lett. 95, 122001 (2005).

10

1

converter method
cocktail method
Ke3
ρ → ee10-1

ω → eehadron
10-2

0

1

2

3

4

5

6

7

8

9
10
pT (GeV/c)3-2E d3σ/dp (mb GeV c3)

Fig. 1. Ratio of non-photonic electrons to photonic background. Error bars are statistical errors and the error bands show the cocktail systematic errors. The
curves in the plot show the remaining non-photonic
background.

10-1

(a)

+

10-2

p+p → (e + e-)/2 + X at s=200 GeV-310

PHENIX data
FONLL(total)
FONLL(c → e)
FONLL(b → e)
FONLL(b → c → e)

10-4
-5

10

-6

10

10-7
-8

10

10-9
10-10

DATA/FONLL

Heavy-ﬂavor (charm and bottom) production serves
as a testing ground of QCD. Because of the large quark
mass, it is expected that next-to-leading order perturbative QCD (NLO pQCD) can describe the production
cross section of charm and bottom at high energy, particularly at high pT . Since heavy-ﬂavor production at
RHIC energies is dominated by gluon-gluon fusion, its
production in polarized p+p collisions probes the gluon
distribution G(x) and the gluon polarization ∆G(x).
Furthermore measurements of heavy-ﬂavor production
in p + p collisions provide a baseline for studying hot
and dense matter eﬀects in heavy ion reactions.
We have measured the momentum distribution ofelectrons from decays of heavy ﬂavor (charm and bottom) for midrapidity |y| < 0.35 in p + p collisions at√
s = 200 GeV over the transverse momentum range
0.3 < pT < 9 GeV/c1) . The data were collected by the
PHENIX detector during the 2005 RHIC run using
the two central arm spectrometers. Each spectrometer covers |η| < 0.35 in pseudo-rapidity and ∆φ = π/2
in azimuth. It includes a drift chamber (DC) and padchambers (PC1) for charged particle tracking, a Ring
Imaging Čerenkov detector (RICH) for electron identiﬁcation, and an electromagnetic calorimeter (EMCal)for electron identiﬁcation and trigger. Two independent methods, the cocktail method and the converter
subtraction method, have been used to determine theheavy ﬂavor yields.
In Fig. 1, ﬁlled circles (squares) show the ratio
of non-photonic electrons relative to photonic background determined by the converter (cocktail) method.
The non-photonic electrons are dominantly heavyﬂavor decay signals. The two methods are consistent
with each other.
Figure 2 (a) shows the invariant diﬀerential crosssection of electrons from heavy-ﬂavor decays. The datafrom the two analysis methods are combined. The data
are compared with a ﬁxed-order-plus-next-to-leadinglog (FONLL) pQCD calculation2) . The top curve in
Fig. 2 (a) shows the central values of the FONLL calculation. The contributions of charm and bottom arealso shown. In Fig. 2 (b), the ratio of the data to
the FONLL calculation is shown. The ratio is nearlypT independent over the entire pT range. Fitting to a
constant for 0.3 < pT < 9.0 GeV/c yields a ratio of
1.71 ± 0.02stat ± 0.18sys . The total charm production
cross section at this energy has also been deduced tobe σcc̄ = 567 ± 57stat ± 193sys µb.

3
2.5
2
1.5
1
0.5
0

(b)

1

2

3

4

5

6

7

8

9
10
pT (GeV/c)

Fig. 2. (a) Invariant diﬀerential cross sections of electrons
from heavy-ﬂavor decays. The error bars (bands) represent the statistical (systematic) errors. The curves
are the FONLL calculations (see text). (b) Ratio of thedata and the FONLL calculation. The upper (lower)
curve shows the theoretical upper (lower) limit of the
FONLL calculation. In both panels a 10% normalization uncertainty is not shown.

1

RIKEN Accel. Prog. Rep. 40 (2007)

Heavy Quark Measurement by Single Electrons in Au+Au Collisions†
F. Kajihara,∗1 Y. Akiba, R. Averbeck,∗2 A. Dion,∗2 H. Hamagaki,∗1 K. Ozawa,∗1 and S. Sakai,∗3
for the PHENIX Collaboration[PHENIX, RHIC, QGP, QCD, Heavy quark, Single electron, Jet quenching]
Strong suppressions of π 0 and other light hadrons athigh transverse momentum (pT ) have been observedin high energy heavy ion collisions at RHIC.1–3) The
suppressions are due to significant energy loss of partons through an extremely dense matter, not conventional hadronic matter. Further insight into propertiesof the produced medium can be gained from the production and propagation of particles carrying heavy
quarks (charm and bottom). A fixed-order-plus-nextto-leading-log (FONLL) pQCD calculation describes
the cross sections of√heavy-flavor decay electrons inp + p collisions at s = 200 GeV within theoretical uncertainties.4,5) In heavy ion collisions, the total yield of heavy-flavor decay electrons was found toscale with the number of nucleon-nucleon collisions.6)
Energy loss via gluon radiation is expected to be reduced for quarks with larger mass due to suppressionof forward radiation, thus increasing the expected thermalization time.7) Consequently, a decrease of high pT
suppression is expected from light to charm to bottom
quarks, with the absolute values and their pT dependence being sensitive to the properties of the medium.
The PHENIX experiment took high statistic data√
at sNN = 200 GeV in Run-4 Au + Au collisions(2004). Electrons (e+ /e− ) in 0.3 < peT < 9.0 GeV/cwere detected by two PHENIX central arms, each covering azimuthal angle ∆φ = π/2 and pseudo-rapidity|∆η| < 0.35.8) All measured electrons can be categorized into two groups: photonic or non-photonic.
Photonic electrons mainly come from Dalitz decays ofmesons (π 0 , η, etc.) and photon conversions, while
signal electrons from open charm/bottom decays are
dominant sources of non-photonic electrons. Two
methods, cocktail and converter methods were applied
to extract non-photonic electrons.5,6) . The both methods give the consistent result. Backgrounds in the
non-photonic electrons come from mainly weak decaysof Kaon (Ke3 ), vector meson decays and Drell-Yan
processes. Kaon contributes < 10 % at peT = 0.5
GeV/c compared to photonic electron yields, while
vector mesons are very small, and Drell-Yan process
is negligible in our measurable peT range. Since Kaonand vector mesons have been already measured by
the PHENIX, backgrounds from those sources can beevaluated with simulations and subtracted from nonphotonic electrons.
†
∗1
∗2
∗3

Condensed from Phys. Rev. Lett. 98, 172301 (2007).
The University of Tokyo
Stony Brook University, NY, USA
University of Tsukuba

Invariant differential yields of heavy-flavor decay
electrons have been calculated in Au + Au collisions.†
To quantify the suppression, the nuclear modification
factor, RAA (peT ) is shown in Fig. 1.
RAA (peT ) =dNeAA /peTdNeAA /dpeT
=
.(1)
pp
e
TAA · dσe /dpT
Ncol · dNepp /dpeT

Here, TAA is the nuclear thickness function forpp
pp
Au + Au . Ncol = TAA · σin. σin
is the inelastic scattering cross section of p + p . Very strong suppression
is clearly seen at high-pT in central collisions, comparable to the suppression observed for π 0 and η 1,3) .
In conclusion, we have measured electrons fromsemileptonic decays of heavy quarks in RHIC Run-4√
Au + Au at sN N = 200 GeV. RAA shows a verystrong suppressive effect. The result suggests that evenheavy quarks lose their energy in high dense medium.
To understand it systematically, we need to separate
the contributions from charm or bottom in the future
experiment. The mass difference will provide us themore information of the energy-loss mechanism in thehigh dense matter.

Fig. 1. RAA (peT ) of heavy-flavor electrons in 0-10 % central
collisions compared with π 0 data and model calculations (curve I9) , II10) , and III11) ). The box at RAA = 1
shows the uncertainty in TAA .

References
1) S. S. Adler et al., Phys. Rev. Lett. 91, 072301, (2003).
2) J. Adams et al., Phys. Rev. Lett. 91, 172302, (2003).
3) S. S. Adler et al., Phys. Rev. Lett. 96, 202301, (2006).
4) M. Cacciari et al., Phys. Rev. Lett. 95, 122001, (2005).
5) A. Adare et al., Phys. Rev. Lett. 97, 252002, (2006).
6) S. S. Adler et al., Phys. Rev. Lett. 95, 082301, (2005).
7) Y. L. Dokshitzer, D. E. Kharzeev, Phys. Lett. B519, 199, (2001).
8) K. Adcox et al., Nucl. Instrum. Methods. A 499, 460, (2003).
9) N. Armesto et al., Phys. Lett. B637, 362 (2006)
10) H. van Hees, V. Greco, R. Rapp, Phys. Rev. C73, 034913 (2006)
11) G. D. Moore, D. Teaney, Phys. Rev. C71, 064904 (2005).

- 70 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

J/ψ → e+ e− Measurements in Au+Au Collisions at
GeV by RHIC-PHENIX†√
sN N = 200

T. Gunji,∗1 H. Hamagaki,∗1 K. Ozawa,∗2 C. D. Silva,∗3 Y. Akiba, and X. Wei∗4[J/ψ, Heavy Ion Collisions, Quark-Gluon-Plasma]

†
∗1
∗2
∗3
∗4

Condensed from the article in nucl-th/0611020, submitted
to Phys. Rev. Lett.
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Universidade de São Paulo, Instituto de Fı́sica, Brazil
RBRC, Brookhaven National Labratory

B

NJ/ψ
dN
1
=
,
dy
Nevt ∆yacc embed(1)

where B is the branching ratio of the e+ e− decay mode
(5.93% from PDG5) ), NJ/ψ and Nevt stand for thenumber of J/ψ counts and the number of analyzed
event, respectively. ∆y in Eq. (1) is the rapidity coverage. The correction factor acc is the acceptance for
e− e+ pairs from J/ψ, where the detection efficiency ofe+ e− pairs and the run-by-run fluctuation of the detector acceptance are taken into account. The correction
factor embed is the embedding efficiency, which has acentrality dependence.
Figure 1 shows the RAA of J/ψ as a function of the number of participants in Au+Au at√
sN N = 200 GeV. The bar and bracket correspondto the uncorrelated error and correlated error, respectively. The box is the systematic error of Ncol . Theband represents the global systematic errors due to theuncertainty of the J/ψ yield in p + p collisions. From
Fig. 1, the suppression of J/ψ by a factor of 3 was observed for most central collisions. This result will be
RAA

Heavy quarknoia (J/ψ, ψ 0 , χc and Υ) has beenlong considered as one of the most promisingprobes for studying the formation of Quark-GluonPlasma (QGP), where the quarks and gluons are deconfined, and its properties. In deconfined matter, theyield of heavy quarkonia is predicted to be suppressed
due to the dymanical color screening effect1) . The dissociation temperature depends on the binding energyof quarkonia and is extracted to be ∼ 2 Tc for J/ψ and∼ 1.1 Tc for ψ 0 and χc by quenched lattice QCD calculations2) . Although the primordial J/ψ is expected tobe dissolved in QGP due to the dynamical color screening effect, J/ψ yield is expected to be enhanced due tothe recombination of uncorrelated cc̄ pairs at the laterstage of collisions at the RHIC energy, where the abundant cc̄ quarks are created3) . Initial state effects (Cold
Nuclear Matter effects, CNM) such as gluon shadowing, absorption of J/ψ in a nuclear environment orColor Glass Condensate (CGC) formation would modify the J/ψ yield. Therefore, it is very important tostudy J/ψ production as a function of colision centralities, rapidity, transverse momentum pT and collision species. PHENIX4) measured J/ψ yield in p + p,
d+Au, Au+Au and Cu+Cu collisions to extract the
CNM and medium effects on J/ψ production. The
nuclear modification factor RAA is a variable widelyused for quantifying the medium effects in A+A collisions. The RAA of J/ψ is the ratio of the J/ψ yieldin Au+Au collisions to that in p + p collisions scaledby the average number of binary nucleon-nucleon collisions Ncol . The RAA of J/ψ is expected to be 1 in
the absence of medium effects and the production of
J/ψ is suppressed due to the medium effects in A+A
collisions if RAA is less than 1.
√
Au+Au collisions at sN N = 200 GeV were performed at RHIC in 2004. During the period, PHENIX
recorded an integrated luminosity of ∼ 240 µb−1 . After the quality assurance of the data, an integrated
luminosity of ∼ 160 µb−1 was used in the analysis.
J/ψ is reconstructed via the e+ e− decay mode andthe number of J/ψ reconstructed is ∼ 1000.
The formula of the J/ψ invariant yield is

1.4

p+p stat. ⊕ sys. error (12%)
sys. error of TAB

1.2
1
0.8
0.6
0.4
0.2
0
0

50

100

150

200

250
300
350
400
Number of Participants

Fig. 1. RAA as function of number of participants in
Au+Au collisions

useful for discriminating the theoretical predictions ofJ/ψ production in A+A collisions and comparison to
the theoretical models is on going.
References
1) T. Matsui and H. Satz; Phys. Lett. B 178, 416, (1986).
2) M. Asakawa and T. Hatsuda; Phys. Rev. Lett. 92,
012001, (2004).
3) L. Grandchamp et al.; Phys. Rev. Lett. 92 212301,(2004).
4) K. Adcox, et al.; (PHENIX Collaboration), Nucl. Instr.
and Meth. A 499 469, (2003).
5) K. Hagiwara et al.; Phys. Rev. D 66, 010001, (2002).

- 71 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

PHENIX measurements on J/ψ production ins = 200 GeV p+p collisions†

W. Xie* for the PHENIX collaboration
Keywords: J/ψ, rapidity, QCD, proton.
PACS: 25.75.Dw
The J/ψ production involves the production of ccbar pairsthat can be well described by perturbative QCD (pQCD)
due to its large mass and the formation of J/ψ from ccbar
pairs that belong to the non-perturbative QCD regime andtherefore provides crucial information to understand QCD.
Experimental data including the results from lower energy
fixed target experiment and especially those from the highenergy collider experiments [1] have stimulated intensive
theoreticalinterests.
However,many
unsolved
discrepancies between data and theoretical predictions
require high quality experimental results at different
collision energies. The results from RHIC with highluminosity would provide crucial constraints to different
models.
A detailed description of the PHENIX experiment isprovided in [2]. The central arm detectors are used to detect
J/ψ−>e+e- decays at midrapidity (|y|<0.35). The muon
detectors are used to measure J/ψ ->µ+µ- at forward (1.2 < y< 2.2) and backward rapidity (-2.2 < y < -1.2). The data inthe year 2005 p+p run corresponds to 2.6 pb-1 at midrapidity,
2.7 pb-1 and 3.5 pb-1 in the forward and backward rapidity,
respectively. Totally ~1500 J/ψ−>e+e- and ~8000 J/ψ−>µ+µ-were reconstructed.

Fig.1. (a) The mid and forward rapidity J/ψ differential
cross section times di-lepton branching ratio versus pT and(b) the ratio of the mid and forward pT spectra.
Fig1.a shows the transverse momentum spectra at both
mid and forward rapidity. <pT2> are extracted via fitting
the data with the function, A (1 + (pT /B)2)6. At†

Condensed from the article at hep-ex/0611020.
* Riken-BNL research center, Brookhaven National Lab- 72 -(GeV/c)2.
mid-rapidity <pT2>= 4.14 ± 0.18( stat ) +−00..30
20 ( sys )2
At forward rapidity <pT > = 3.59±0.06(stat)±0.16(sys)(GeV/c)2. The ratio of the invariant cross section at forwardand mid-rapidity is shown in Fig. 1b. The data indicates thatthe forward rapidity pT distribution is substantially softer
than mid-rapidity.
Fig.2 shows the J/ψ differential cross section vs.
rapidity. The total cross section is determined to be
J /ψBll ⋅ σ pp
= 178 ± 3 ± 53 ± 18 nb via fitting the rapidity

Fig.2. J/ψ rapidity distribution
distribution with many theoretical shapes. An empirical
double Gaussian fit (dot-dot curve) that can reproduce thedata best is used as the central value of the total crosssection. The first error is statistical, the second systematicand the third is from the uncertainty in the minimum-bias√ section. The systematic error is estimated fromtrigger crossthe maximum variation observed when shifting the
mid-rapidity and forward rapidity measurements
independently by their point-to-point correlated systematic
errors. Theoretical calculations including a NRQCD
calculation (dashed curve) [3] and a pQCD calculation(dot-dashed curve) [4] failed to describe the data
In summary, new J/ψ results for p + p collisions at
s = 200 GeV are presented that extend the reach intransverse momentum to 9 GeV/c. The rapidity distribution
can not be reproduced by the pQCD and NRQCD
calculations in [3,4]. These data not only constrain
production models for heavy quarkonia, but also provide a
critical baseline for similar studies in deuteron-nucleus andheavy-ion collisions.
References
1) F. Abe et al., Phys. Rev. Lett. 79, 572 (1997);
S. S. Adler et al., Phys.Rev.Lett. 92 (2004) 051802
2) K. Adcox et al., Nucl. Instr. Meth. A499, 469 (2003).
3) F. Cooper et al., Phys. Rev. Lett. 93, 171801 (2004);
and private communication.
4). V. A. Khoze et al. , Eur. Phys. J. C39, 163-171 (2005)

RIKEN Accel. Prog. Rep. 40 (2007)√
Measurement of High-pT Direct Photons in sNN = 200 GeV
Au+Au Collisions at RHIC-PHENIX

T. Isobe,∗1 H. Hamagaki,∗1 T. Sakaguchi,∗2 G. David,∗2 and B. Sahlmueller∗3 in collaboration with PHENIX[Relativistic Heavy-Ion Collision, Quark-Gluon Plasma, Direct Photon]

RAA (pT ) =d2 NAA /dpT dη
,
TAA (b)d2 σNN /dpT dη

(1)where the numerator is the invariant direct-photon
yield in unit rapidity and the denominator is the
expected yield from p+p collisions binary scaledby the number of underlying nucleon-nucleon collisions (TAA (b)) in Au+Au. TAA (b) is deﬁned as
TAA (b) = Ncoll (b)/σNN , where Ncoll (b) is the average number of nucleon-nucleon collisions determinedby the distance (b) between the two nucleons with aninelastic cross section σN N . Figure 2 shows the RAA of√
the direct photon in sNN = 200 GeV Au+Au central(0-10%) collisions. The RAA is in good agreement withunity within the error. This suggests that the initial
hard-scattering probability is not reduced by nuclear
eﬀect. The direct-photon RAA seems to be below unity
above 14 GeV/c. This tendency may indicate that thecompensation of jet-quenching and additional photons
by a nuclear eﬀect breaks up above 14 GeV/c. Since
the direct photons measured in a p+p system consist of the photons promptly produced directly fromthe hard scattering and the jet fragmentation photons
∗1
∗2
∗3

Center for Nuclear Study, Graduate School of Science, University of Tokyo
Brookhaven National Laboratory, USA
University of Muenster, Germany

from hard-scattered partons, the direct-photon yieldmeasured in Au+Au collisions is expected to be suppressed by the jet-quenching eﬀect. The agreementwith scaled p+p direct-photon data might simply bea coincidence caused by mutually counterbalancing effects such as energy loss and jet-photon conversion.
d2N (GeV/c)-212π p TNevt dpTdy

103
PbSc direct photon pT spectra

1

Au+Au sNN = 200GeV

10-3

PHENIX preliminary
min. bias • 10 3-610

0-10% • 10 0

10-9

10-20% • 10 -2
20-30% • 10 -4

10-12

30-40% • 10 -6

10-15

40-50% • 10 -850-60% • 10 -10

-18

10

60-70% • 10 -12

10-21

70-80% • 10 -14
80-92% • 10 -16

10-24
10-27
0

2

4

6

8 10 12 14 16 18 20 22 24
pT(GeV/c)√
Fig. 1. pT spectra of direct photons in sNN = 200 GeV
Au+Au central collisions. In addition to the statisticaland pT -uncorrelated errors, point-to-point varying systematic errors are shown on the data points as boxes.
TAA -scaled p+p direct-photon data are overlaid.
Direct Photon Au+Au sNN = 200GeV, 0-10%
2
RAA

The PHENIX experiment1) has been carried out
at RHIC to search for evidence of the phase transition from normal nuclear matter to quark-gluon
plasma (QGP). QGP is a new phase of matter consisting of deconﬁned quarks and gluons.
Since photons do not interact strongly, direct photons are a powerful probe for studying the initial stateof matter produced at RHIC. Direct photons in thisreport mean photons not originating from hadronic decays. They are emitted from all the states such as theinitial state, the QGP, and the ﬁnal hadron-gas state.
In addition, it is predicted that the contribution of photons from jet-photon conversion in the dense medium
to direct photon can be as large as the photon yieldfrom hard scattering2) .
In the 2004 run, PHENIX recorded a high-quality
Au+Au data set. The data set allows us to measure direct photons at up to 20 GeV/c as shown in Fig. 1. The
amount of nuclear eﬀect in Au+Au collisions is quantiﬁed by a nuclear modiﬁcation factor (RAA ). RAA is
the ratio of the measured yield to the expected yieldfrom the p+p result3) , and is deﬁned as

1.8
1.6

PHENIX
preliminary

1.4
1.2
1
0.8
0.6
0.4
0.2
0
0

2

4

6

8

10

12

14

16

18

20

pT (GeV/ c )Fig. 2. Nuclear modification factor of direct photons in√
sNN = 200 GeV Au+Au central (0-10%) collisions.
The overall systematic error of TAA normalization isshown at 1.

References
1) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res.
A499, 469 (2003).
2) S. Turbide et al.: Phys. Rev. C72, 014906 (2005).
3) K. Adcox et al.: hep-ex/0609031 (2006).

- 73 -

1

RIKEN
Prog. Rep.
Rep. 3940 (2006)(2007)RIKEN Accel.
Accel. Prog.

√
Elliptic ﬂow of electrons from heavy ﬂavor decay in sN N = 200
GeV Au+Au collisions at RHIC-PHENIX
S. Sakai,∗1 Y.Akiba, R. Averbeck,∗2 A. Dion,∗2 , F. Kajihara,∗3 for the PHENIX collaboration

where N0 is a normalization constant, φ is a azimuthal
angle of the particle, and ΨR.P. is the direction of thenuclear impact parameter (“reaction plane”) in a given
collision. One of the most signiﬁcant discoveries at
RHIC is that the v2 of hadrons made of u, d, s quarks
is large and consistent with a hydrodynamical model2) .
Furthermore, it was found that v2 scales with the number of constituent quarks. This result suggests that thev2 of hadrons made of u, d and s quarks develops in thepartonic phase. If charm quarks ﬂow similaery to lightquarks, an unexpectedly strong interaction of charmwith the medium is expected.
In the PHENIX experiment at RHIC, a charm quark
has been studied by measuring electrons from theirsemileptonic decays1) . An inclusive electron sample has two components: (1)“nonphotonic” - primarily semileptonic decays of mesons containing heavy(charm and bottom) quarks and (2)“photonic” - Dalitz
decays of light neutral mesons (π0 , η, η 0 , ω and φ) andphoton conversions in a detector material. The azimuthal distribution of the inclusive electron (dN e /dφ)is given as the sum of the azimuthal distributions ofphotonic electrons (dN γ /dφ) and nonphotonic electrons (dN non−γ /dφ):dNeγ
dNenon−γ
dNe
=
+
.
dφ
dφ
dφ

∗2
∗3

Univ. of Tsukuba
Univ. of Stony Brook
Univ. of Tokyo(1 + RN P )v2e − v2γe
,
RN P

(3)

where v2e is the inclusive electron v2 , v2γe is the photonic electron v2 and RN P is the ratio of the numberof nonphotonic electrons to that of photonic electrons(Nenon−γ /Neγ ). The photonic electron v2 (v2γ ) is calculated using a Monte Carlo generator that includes
π 0 , η, and direct photons. The measured v2 (pT ) of±0
π ± ,π 0 and K ± is used as input, assuming v2π = v2π ,±v2η = v2K , and v2 (directγ) = 0.

(1) c thermal(2) σp = 10 mb (AMPT)(3) c+b → e v 2 (reso)(4) pQCD

0.15

0.1

0.05

0

-0.05
0

0.5

1

1.5

2

2.5

3

3.5

4

4.5
5
pT (GeV/c)

Fig. 1. Transverse momentum dependence of heavy-ﬂavor
electron v2 . The lines in the ﬁgure represent model
calculations.

Figure 1 shows the transverse momentum dependence of the heavy-ﬂavor electron v2 . A small background due to Ke3 decays is subtracted. The lines
in the ﬁgure represent model calculations. The model(1) assumes charm quark thermalization and ﬂow3) .
The model (2) is for AMPT model calculation assuming a large cross section (10 mb)4) and (3) resonant D
and B meson correlations in the sQGP5) . The model(4) involves pQCD calculation (no interaction)6) . The
models (1), (2) and (3) well represent the measured v2 .
Therefore, the result indicates that charm quarks arestrongly coupled to the matter and ﬂow.
References(2)

From Eq. 2, the nonphotonic electron v2 (v2non−γ ) isexpressed as∗1

v2non−γ=ev2Charm quarks are believed to be produced in theinitial stage of heavy ion collisions by gluon fusion andto propagate through the hot and dense medium created in the collisions. Therefore, charm quarks canbe a good probe for studying the medium created in
Au+Au collisions at RHIC. For the medium study,
charm quark energy loss and ﬂow measurements areuseful analysis tools. A recent study of charm by electron measurement suggests the large energy loss ofcharm quarks in the medium created in the Au+Au√
collisions at sN N = 200 GeV1) .
The azimuthal anisotropy of particle emissions is a
powerful tool for studying ﬂow in ultra relativistic nuclear collisions. The azimuthal anisotropy is deﬁned
by
{
}
∑
dN
= N0 1 +2vn cos(n(φ − ΨR.P. )) ,
(1)
dφ
n

1) PHENIX Collaboration, S. S. Adler et al., Phys. Rev.
Lett. 96, 032301 (2006).
2) PHENIX Collaboration, S. S. Adler et al., Phys. Rev.
Lett. 91, 182301 (2003).
3) V. Greco et al., Phys. Lett. B 595 202-208 (2004).
4) Bin Zhang et al., Phys. Rev. C 72, 024906 (2005).
5) H. van Hendric et al., Phys. Rev. C 73, 034913 (2006).
6) N. Armesto et al., Phys. Lett. B 637, 362 (2006).

- 74 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Measurement of Double-Helicity Asymmetry in Multiparticle
Production from Polarized Proton-Proton Collision at PHENIX
K. Nakano∗1 , Y. Akiba and Y. Goto

(1)Here, N++ and N+− are the number of measured particle clusters with the same and opposite beam helicities,
respectively; R ≡ L++ /L+− is the relative luminosity;and PB and PY are the beam polarizations of the colliding beams.
We used√ proton-proton collision data obtained in2005 at s = 200 GeV with an average beam polarization of ∼46%. The integrated luminosity of theanalyzed data is 2.2 pb−1 . The PHENIX Central Arm
detector was used. Two arms are positioned almost
back-to-back, and each arm covers a pseudorapidity region |η| < 0.35 and a 90 degree azimuthal angle. Photons with pT > 0.4 GeV/c were measured using electromagnetic calorimeters, and charged particles with
0.4 < pT < 4 GeV/c were measured using drift chambers and pad chambers. For each event, a high-pT (> 2
GeV/c) photon was required to exist.
Particles that satisﬁed the experimental criteria wereclustered by a cone method with a cone radius R of0.31) . The transverse momentum of the cone, pcone,T
was deﬁned as thevectorsumofpof
particles
the
T
¯
¯
P
in cone; pcone≡ ¯ i∈cone p~T i ¯. The relation betweenTthe measured pcone
and the original pjet
T
T was evaluatedusing PYTHIA and GEANT simulations1) .
The largest systematic uncertainty in this measurement results from the pT scale diﬀerence between measurement and theory. This originates from the factthat a jet is deﬁned with a cone at the hadron level inthe measurement and at the parton level in the theory. In ALL measurement, we assigned 10% to the pT
scale uncertainty, by which the pT scale in the theory varies when a theoretical cone size is changed in a
typical range. We can check the pT scale uncertainty
by measuring cross sections because the diﬀerence inthe pT scale appears as a shift of cross-section curve.
Figure 1 shows the yield per luminosity of the particle
cluster as a function of pcone. The experimental dataT
∗1

Department of Physics, Tokyo Institute of Technology- 75 --1

1
N++ − RN+−.
|PB ||PY | N++ + RN+−

Yield of particle cluster per luminosity [1/pb ]ALL =is drawn as red points with systematic errors as a grayband. The predicted values are drawn as three solidor dashed lines, which are based on the NLO jet crossconerelation. The band aroundsection and the pjet
T -pT
the solid line shows the deviation range of the solidline caused by a ±10% pT scale variation. The experimental data and the predicted value are within therange.
Figure 2 shows the ALL of particle cluster production as a function of pcone. The predicted ALL ’s areTdrawn as solid lines, which are based on the NLO jet
ALL , the three ∆g(x) models3) and the ratio of pconeTto pjetT . The bands around the solid lines show the
10% pT scale uncertainty. This result excluded the“GRSV-max” case. A stronger constraint on ∆g(x)will be imposed by further statistics.
particle cluster with high-pT photonoin PHENIX Central Arm (|η| < 0.35, ∆φ = 90 × 2)

106

PH ENIX Preliminary
105

104

10

3

4

NLO (R=1, scale µ=pT/2, pT, 2 pT)
cone
pjet
with PYTHIA MPI
T → pT
10% pT scale difference (yellow band)
6

8

10

12

14
pcone
[GeV/c]T

Fig. 1. Yield per luminosity of particle clusters.

-1

particle cluster ALL

One of the goals of the PHENIX experiment is toobtain the polarized gluon distribution function in the
proton, ∆g(x). ∆g(x) is evaluated by measuring the
double-helicity asymmetry, ALL , of reactions in longitudinally polarized proton-proton collisions, for example, jet, π 0 or direct photon production. A jet ismeasured as a cluster of multiple particles. The particle cluster measurement gives higher statistics at hightransverse momentum (pT ) than single-particle measurements such as π 0 . ALL is deﬁned as

0.06

Run5 (2.2 pb , 46% pol.)~40% pol. scale error is not included

GRSV-max

PH ENIX Preliminary

0.04
0.02

GRSV-std0∆ g=0 input

NLO (R=1)-0.02 pT is scaled with PYTHIA MPI
10% pT scale uncertainty (yellow band)
3

4

5

6

7

8

9

10

11

12
13
pcone
[GeV/c]T

Fig. 2. Particle cluster ALL .

References
1) K. Nakano et al.; RIKEN Accel. Prog. Rep. 39, 183(2006).
2) R. Field [CDF Collaboration], Acta Phys. Pol. B 36,
167 (2005).
3) M. Gluck, E. Reya, M. Stratmann, and W. Vogelsang,
Phys. Rev. D 63, 094005 (2001).

1

RIKEN Accel. Prog. Rep. 40 (2007)√
Direct photon production in p + p at s = 200 GeV, and its double
spin asymmetry measurement
K. Okada, R. Bennett,∗1 and T. Horaguchi,∗2
As regards the RHIC-PHENIX spin program, direct
photon production is believed to be a golden channel
for accessing the gluon polarization in proton. Using
Run3(2003) data set (L = 0.24pb−1 ), we improved theprecision of measurement of direct photon cross section
1). The analysis starts from the inclusive photon in
the PHENIX detector2) , and backgrounds, mainly π 0
decay photons, are subtracted statistically. Figure 1
shows the spectra overlaied with a Next-to-LeadingOrder (NLO) calculation. The result is described wellby the theoretical calculation.
The double spin asymmetry, defined by the difference in production ratio between parallel and antiparallel helicities of the colliding bunches of protons divided by the sum of them, is sensitive to gluon
spin polarization. The statistical background subtraction for each helicity state does not provide the highest precision. Instead, we subtract the backgroundasymmetry afterward3) . The asymmetry of the signal(Asig ) is calculated from the asymmetry of all photons(Araw ) and the asymmetry pof background (ABG ) by
raw

2
2 2
σA
raw +r σ BG

BG

(a)

PHENIX Data

3-2

Ed 3σ /dp [pb GeV c-3]

−rA
A
Asig = A 1−r, σAsig =, where r
1−r
is related to the purity defined by the ratio of BG toraw, and σAsig is the statistical uncertainty.
To obtain a purer sample (=lower r), we applied an

NLO pQCD(by W.Vogelsang)
CTEQ 6M PDF
BFGII FFµ=1/2pT,pT,2pT

4

10

3

10

isolation cut on a photon sample, because direct photons are expected not to come with other jet activities.
We also determined that 80 ∼ 90% of direct photons
satisfy the isolation cut for the region of pT higher than
7 GeV/c1) .
It should be reasonable to measure the asymmetry ofbackground (ABG ) using photons associated with π 0 ’s
decay partner. On the basis of real Run5(2005) data
(L = 2.5pb−1 ), assuming the statistical uncertainty
to be the root mean square of the yield, the size ofσAsig was obtained and shown in Fig. 2. The bin sizeis large at pT higher than 10GeV/c. An advantageof the isolation cut can be noted in the figure. In thecase without the isolation cut, σAsig is underestimated,because the combinatorial background contaminationin the π 0 tagging process is not taken into account.
In summary, we proved that the theoretical√baseline
is applicable to direct photon production at s = 200
GeV p + p collisions by the cross section measurement.
For spin asymmetry measurement, the precision was
evaluated. The isolation cut improves the measurement. The√values shown in Fig. 2 are scaled by luminosity (1/ L) and beam polarization (1/P 2 ).
The machine performance is improving each year inboth luminosity and polarization. We have collected
L = 7.5pb−1 with longitudinal polarization at P =62% in Run6(2006). In the next 3 years, we plan toaccumulate L = 65pb−1 . By then, the experimental
uncertainty of this channel will be comparable to ourcurrent knowledge of gluon polarization.
References
1) S. S. Adler et al.: Phys. Rev. Lett. 98, 012002 (2007)
2) K.Adcox et al.: Nucl. Inst. Meth. A499, 469 (2003).
3) S. S. Adler et al.: Phys. Rev. Lett. 93, 202002 (2004)

2

10

PH ENIX(Data-Theory)
Theory

1

2

σA

10
0.35
0.3
0.25

(b)

Run5 statistics (L=2.5/pb)
with isolation cut
without isolation cut

1
0.2

0

-1

0

0.15

2

4

6

8

10

12

14

16

γ
pT [GeV/c]

0.1
0.05

Fig. 1. Direct photon spectra overlaied with NLO pQCD
calculation∗1∗2

SUNY, USA
Hiroshima University, Japan

0

6

8

10

12

14

16

18

pT[GeV/c]

Fig. 2. σA estimation using Run5pp statistics.

- 76 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Measurement of the mid-rapidity double helicity asymmetry of η√
mesons in p+p collisions at s = 200GeV
F. Ellinghaus∗1 and J. Seele∗1 for the PHENIX Collaboration
Measurements of double helicity asymmetries for inclusive hadron production in polarized proton-proton
collisions are sensitive to spin–dependent parton distribution functions (PDFs), in particular to the gluon distribution, ∆g. First results from the PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC)
are available for inclusive π 0 production1) . The double
helicity asymmetry ALL is given as
σ ++ − σ +−∆σ=σ ++ + σ +−σwhere the cross section σ ++ (σ +− ) describes the reaction where both protons have the same (opposite) helicity. The spin–dependent term ∆σ is a convolution of
the spin–dependent PDFs for quarks (u,d,s) and gluons, of the spin–dependent hard scattering cross sections calculable in perturbative QCD, and of the fragmentation functions (FFs). It is apparent that theextraction of the spin–dependent PDFs from data on
inclusive hadron production critically depends on theknowledge of the FFs. Therefore it is desirable to extract the spin–dependent PDFs using different channels, not only because of possibly different systematic
uncertainties involved in the ALL measurement, butalso because of the different FFs involved. An effort is under way to extract the presently unknownη FFs, mainly based on cross–section measurementsfrom e+ /e− collider data.
This study focuses on ALL in η production (~p+p~→
η + X), where the η subsequently decays into two photons with a branching ratio of about 40%. The data
was taken with the PHENIX spectrometer in 2005.
The position and energy of the photons are reconstucted using the electromagnetic calorimeter. The invariant mass is then calculated from all possible photon
pairs and is shown in Fig. 1. Besides the prominent π 0
peak between about 0.1 and 0.2 GeV/c2 , the η peak(grey region) can also be clearly seen.
Experimentally, the double helicity asymmetry is defined as1
N++ − RN+−ALL =,|PB ||PY | N++ + RN+−with

Mγγ (GeV/c2)

Fig. 1. Two photon invariant mass for pT > 2 GeV/c.

for the data from 2005 is 47% with an uncertainty of
20% per beam, leading to a 40% scale uncertainty inthe preliminary ALL result.
η+BG
Calculating the asymmetry ALL
in the grey region (see Fig. 1), consisting of signal and background,and the asymmetry ABG
LL in regions with only background (the hatched regions), the background corrected η asymmetry can be extracted by
AηLL =

0.15

with

r≡

N BG
.
N η + N BG

PHENIX Preliminary (Run 5)

p+p→η+X
0.1
0.05
0
-0.05
-0.1
-0.15

L++
R≡
,
L+−

Scaling error of 40% is not included
2

3

4

5

6

7

8

pT (GeV/c)

where N++ (N+− ) is the experimental yield for thecase where the beams have the same (opposite) helicitiy. The achieved uncertainty on the relative luminosity R is on the order of 10−4 . The polarizations of
the two colliding beams at RHIC are denoted by PB
and PY . The preliminary average polarization value
∗1

η+BG
ALL
− rABGLL,
1−r

The resulting background corrected asymmetry AηLL
as a function of pT is shown in Fig. 2.
η
ALL

ALL =

Counts

University of Colorado, Boulder, Colorado, USA- 77 -

Fig. 2. Double helicity asymmetry for the inclusive η production as a function of pT .

References
1) [PHENIX Collaboration], S.S. Adler et al., Phys. Rev.
Lett. 93 (2004) 202002. S.S. Adler et al., Phys. Rev. D
73 (2006) 091102.

1

RIKEN Accel. Prog. Rep. 40 (2007)

Accessing the Gluon Polarization through π ± ALL at PHENIX
A. Morreale,∗1 C. Aidala,∗2 K. Boyle,∗3[Proton Spin, Pi Mesons, Charged Pions]

∗1
∗2
∗3

Department of Physics, University of California at Riverside
Department of Physics, University of Massachusetts
AmherstDepartment of Physics, Stony Brook University- 78 -

0.2

ALL

The double longitudinal asymmetries (ALL )of pion
production in polarized proton proton collisions, is oneof the various probes that will form part of ∆g global
analysis that aims to disentangle all of the partonic
contributions to the proton spin1) . In proton-proton
collisions at PHENIX central rapidities, π production
proceed from quark-gluon and gluon-gluon initiatedsub processes in the measured pT range of 5-10GeV/c.
This, along with other π meson properties such as zero
spin and pseudo scalar under parity transformation,
makes the π an accessible channel whose importance
may elucidate information on the gluon’s contribution
to the proton’s spin. Preferential fragmentation of up
quarks to π + and down quarks to π − leads to dominance of up-gluon and down-gluon contributions in thesum over flavors in a factorized pQCD calculation of π
production. In addition, the polarized parton distribution functions(pdf’s) are well known to be ∆u >0 and∆d < 0 from polarized DIS experiments. This dominance of u or d combined with the different signs on
their polarized distributions translates into potentiallymeasurable differences in the asymmetries for the different π species that depend on the sign of ∆g.
The PHENIX detector at RHIC has fine-grained
calorimetry 100 times finer than previous collider detectors, making particle identification excellent, theresolution of the electromagnetic calorimeter (EMCal)is δη∗δφ = 0.01∗0.01.2). We select the π ± signal by requiring a deposition of an energy cluster in the EMCal
associated with a charged track in coincidence with thecollision trigger. Due to the hadronic response in the
EMCal, less than 23 of the π ± signal triggers an event.
We furthermore identify π ± by selecting particles that
produced Čerenkov light in our ring imaging Čerenkov
detector (RICH) but did not pass an electromagnetic
shower-shape cut in the EMCal cluster.
The measurement presented consists of 0.89 billion
events analyzed within pT range of of 5-10 GeV/c, corresponding to an analyzed sample of approximately 2.3
pb−1 with an average polarization of 47%. The primary source of potential background in this analysis
comes low energy electrons with misreconstructed momentum and charged hadron tracks firing the RICH.
We performed a series of detector cuts which include:
EMCal shower-shape cut designed to eliminate 80%of all electrons, a pT -dependent energy cut to remove
tracks with mis-reconstructed momentum and a cut of

π+

0.15

PHENIX Preliminary Run 5

π-

0.1
0.05
-0
-0.05
-0.1
Scale uncertainty of ±40% not included
-0.15

1

2

3

4

5

6

7

8

9
10
pT (GeV/c)

Fig. 1. Measurement of negative(solid circles) and positive(open circles)π ± ALL . A scale uncertainty of 40%
due to the polarization uncertainty of the beams is notincluded.

energy/momentum < 0.9 to remove the remaining electrons with nearly the correct reconstructed momentum. To estimate the remaining background fraction,
the pT region below 4 GeV/c was fit to a power law.
Above 4GeV/c an extrapolation of the fit under thesignal region was performed. The background using
this method was estimated to be < 5%.
The ALL formula used in this analysis is as follows:
ALL =
R=

N++ − RN+−1
σ++ − σ+−=(1)
σ++ + σ+−|PY ||PB | N++ + RN +−

L++
L+−

(2)

Where ++(+-)are the beams in same(opposite) helicity configuration.
The first measurement of Run-05 π ± ALL at thepT range 5-10GeV/c and the associated statistical errors are shown in Fig. 1. A scale uncertainty of 40%
due to the polarization uncertainty on the beams is
not included. The statistical uncertainty in ALL using Run-06 data currently in production is expected
to be aproximately 2.7 times smaller. While the background in this measurement is significantely lower thanπ 03) , current statistical uncertanties do not constrain∆g significantly. We expect that this analysis withthe higher statistics and the cross-section measurement
will be forthcoming and essential in pQCD interpretations and the constrain of ∆g.
References
1) B. Jäger et al: Phys. Rev. D 67, 054005 (2003).
2) K. Adcox et al.: Nucl. Inst. Meth. A 499, 469 (2003)
3) S.S. Adler et al.: Phys. Rev. Lett. 93,202002 (2004).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Double Helicity Asymmetry of Inclusive π 0 Production in Polarized√
pp Collisions at s = 62.4 GeV
K. Aoki,∗1 A. Bazilevsky,∗2 K. Boyle,∗3 A. Deshpande,∗3 Y. Goto for the PHENIX Collaboration
Despite various efforts towards the understanding of
proton spin, there remains a large uncertainty on ∆G,
the gluon spin contribution to the proton. RHIC, theworld’s first polarized pp collider, provides us with anopportunity to directly probe gluons in the proton andinvestigate ∆G. The double helicity asymmetry (ALL )of inclusive π 0 production in polarized pp collisions issensitive to ∆G because π 0 production is dominatedby quark-gluon and gluon-gluon interactions.
The PHENIX experiment at RHIC has the ability to clearly identify π 0 through its gamma decay using EMCal (electromagnetic calorimeter), which
covers the central rapidity region (|η| < 0.35) andhalf the azimuthal angle.1) PHENIX also has an excellent gamma-triggering capability (the threshold is
0.8 GeV or 1.4 GeV), which makeshigh-statistics π 0measurement feasible.2) PHENIX √has previously reported π 0 ALL in pp collisions at s = 200 GeV, 3)
which indicates that ∆G is not large.4) However, alarge uncertainty remains for large Bjorken x (> 0.1)
and more statistics are needed. During the run in
2006(Run 6), data were collected over one week at√
s = 62.4 GeV. Spin-rotator commissioning was successful and we had longitudinally polarized collisions.5)
Even in this short period of data collection with asmall integrated luminosity of 60 nb−1 and an average polarization of 48%, the lower-energy collision isadvantageous for covering a larger x region. At a fixedxT ,√the cross section is ∼ 300 times larger than thatat s = 200 GeV. Ten-times-higher statistics are ex0
pected√ compared with the previosly reported π ALL
at s = 200 GeV, which is based on an integrated luminosity of 1.8 pb−1 with an average polarization of047%.
√ In this report, the preliminary results of π ALL
at s = 62.4 GeV are presented.
ALL is calculated as1
N++ − RN+−
L++
ALL =
, R=
,
|PB ||PY | N++ + RN+−
L+−

∗2
∗3

Kyoto University, Kyoto, Japan.
Brookhaven National Laboratory (BNL), USA.
Department of Physics, Stony Brook University, USA.

ALL(π0)0.1

preliminary

0.08

GRSV-maxs
pp л62.4GeV

0.06
0.04

∆g= -gGRSV-std

0.02

∆g=0

0
-0.02
40% scale error not included

-0.04

1

1.5

2

2.5

3

3.5

4

p T (GeV/c)

Fig. 1. π 0 ALL as a function of pT . The error bar denotes
statistical uncertainty. The gray band denotes the systematic error from relative luminosity.

0.1
0.08

ALL(π0)
Run6 62GeV Preliminary
Run5 200GeV Preliminary

G

6
ax(
V-m
RS

V
2Ge

)

0.06
0.04
0.02

GR

(2
ax
-m
SV

G
00

eV)

eV)
td(200G
GRSV-s)eVtd(62GGRSV-s0-0.02 40% scale uncertainty-0.04
0

is not included

0.02

0.04

0.06

0.08

0.1

0.12

xT

(1)
Fig. 2. π 0 ALL as a function of xT .

where PB(Y ) denotes the beam polarization in the Blue
(Yellow) RHIC ring, N is the π 0 yield, L is the luminosity and ++ (+-) represents the helicity state of
the beams. We used Beam-Beam Counter1) to measure R. Its uncertainty is estimated by comparing thecount to Zero-Degree Calorimeter1) counts, and it isfound to be δR = 1.3 × 10−3 . This corresponds toδALL = 2.8 × 10−3 , which is less than the statisticaluncertainty.
∗1

The systematic uncertainty is evaluated by thebunch-shuffling technique,3) and it is found to be negligible. Figure 1 shows the Run 6 results of π 0 ALL as afunction of pT . Theoretical curves based on perturbative QCD (pQCD) using the four models for polarized
parton distribution functions are also shown.6) Figure
2 shows the Run 6 results of π 0 ALL√ as a function ofxT together with Run 5 results at s = 200 GeV. A
clear statistical improvement is in the √large-xT region.
To test the pQCD applicability at s = 62.4 GeV,
analysis on the π 0 production cross section is ongoing.
With our cross section result, we will be able to discuss
our ALL result further with pQCD calculations.

References
1) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res. A
499, 469 (2003).
2) K. Okada et al.: RIKEN Accel. Prog. Rep. 36, 248(2003).
3) Y. Fukao et al.: RIKEN Accel. Prog. Rep. 39, 175(2006).
4) M. Hirai et al.: Phys. Rev. D 74, 014015 (2006).
5) M. Togawa et al.: RIKEN Accel. Prog. Rep. 40, 84(2007).
6) B. Jäger et al.: Phys. Rev. D 67, 054005 (2003).

- 79 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Measurement of Double Helicity Asymmetry in π 0 Production in
Polarized Proton Collisions at PHENIX
K. Boyle,∗1 A. Bazilevsky,∗2 A. Despande,∗1,∗3 and Y. Fukao∗4 for the PHENIX Collaboration[Proton spin, Proton structure]
The quark spin contribution to the proton spinhas been found using fixed target polarized DIS measurement to be only about 25%. The other possible
sources, gluon spin and orbital angular momentum ofquarks and gluons, must contribute the remaining spin.
At PHENIX, we can constrain the gluon spin contribution to the proton spin through measurements ofa double helicity asymmetry, ALL , in longitudinallypolarized proton collisions.
√ In this report we focus on
ALL for π 0 production at s=200 GeV. ALL is definedasσ++ − σ+−ALL =(1)
σ++ + σ+−where σ++ (σ+− ) is the cross section with same (opposite) helicity. Experimentally, we measure
R=

L++
.
L+−

(2)

where L is the integrated luminosity, R is the relative
luminosity, P1 and P2 are beam polarizations and N
is the particle yield.
The relative luminosity measurement has been described1) . In 2005 (2006), the systematic uncertainty
in ALL due to relative luminosity was δALL |R =2.3 × 10−4 (δALL |R = 1.5 × 10−4 ).
Average beam polarization for 2005 (2006) was 47%(62%). The remaining transverse components in 2005
were 10.3±2.1% and 14.5±2.2% for the two beams2) .
The asymmetry we actually measure isAmeas = (1 − ²)ALL + ²AT T ,AT T =∗2∗3∗41) K. Boyle et al.: RIKEN Accel. Prog. Rep. 39, 197(2005).
2) M. Togawa et al.: RIKEN Accel. Prog. Rep. 39, 198(2005).
3) K. Boyle et al.: RIKEN Accel. Prog. Rep. 40, (2006).
4) S. S. Adler et al.: Phys. Rev. Lett. 91, 241803 (2001).
5) M. Glück et al.: Phys. Rev. D 63, 094005 (2001).

σ↑↑ − σ↑↓(3)σ↑↑ + σ↑↓where ² is the product of the remaining transverse components, and AT T is an azimuthally independent double transverse spin asymmetry. This was measured
in PHENIX3) and found to be consistent with zero.
Therefore, a systematic uncertainty due to the remaining transverse polarization in the proton beams for
0
AπLL of 0.075×δALL |stat is assumed.
The measurement technique has been described4) .
0
Figure 1 shows AπLL from the 2005 RHIC run (bluecircles) and the 2006 RHIC run (red triangles). The
2005 (2006) result was based on 1.8 (7.5) pb−1 and
47% (62%) polarization. Final 2005 results will include ∼30% more data. Full production for the 2006
∗1

References

Department of Physics, Stony Brook University
Brookhaven National Laboratory
RIKEN BNL Research Center
Department of Physics, Kyoto University01
N++ − RN+−,
|P1 ||P2 | N++ + RN+−

π
ALL

ALL =

data set was not completed at the time of this report,
but a filtered data set requiring a high pT photon wasavailable. Due to this high pT photon requirement,
2006 data with pT <5 is not yet available.
In Fig. 1, four NLO pQCD theory calculations5) areplotted with the data, assuming, at Q2 =0.4 GeV2 , aninput value for ∆g of +g (GRSV-max), −g, 0, and thebest fit to world data for ∆g as of5) (GRSV-std). By
calculating the χ2 /NDF for each curve with respect
to both the 2005 and 2006 results, we can estimate
how well these values agree with the data. Theoretical uncertainties are not considered in these calculations. Both ∆g = +g and ∆g = −g are strongly disfavored by the data, with a likelihood of less than 0.1%.
GRSV-std and ∆g = 0 are consistent with our data,with likelihoods of 2-9% and 11-12%, respectively. The
range in likelihoods come from including a 40% scaling uncertainty due to beam polarization measurement
uncertainty. The addition of low pT data may allow us
to differentiate between GRSV-std and ∆g=0.

PHENIX Preliminary
0.06

GRSV-max

Run5 Photon Trigger
Run6 Photon Trigger, high pT

0.04∆g = -g

0.02

GRSV-std

0

-0.02

-0.04
0

∆g = 0
Scaling error of 40%
is not included.
1

2

3

4

5

6

7

8

9
10
pT (GeV/c)0Fig. 1. AπLL from 2005 RHIC run (blue circles) and 2006
RHIC run (red triangles) plotted with four theory
curves calculated with NLO pQCD5) . Curves are calculated with results from polarized DIS, assuming four
values for gluon polarization described in the text.
Run6 result currently only includes high pT photon filtered data, with more data at lower pT expected soon.

- 80 -

1

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)

Measurement of Double Transverse Spin Asymmetry in π 0
Production in Transversely Polarized Proton Collisions at PHENIX
K. Boyle,∗1 A. Bazilevsky,∗2 A. Despande,∗1,∗3 and Y. Fukao∗4 for the PHENIX Collaboration[Proton spin, Proton structure, transversity](1)

where ǫ is the product of the remaining transverse components in the two beams, and AT T is the double transverse spin asymmetry defined as
AT T =σ↑↑ − σ↑↓.
σ↑↑ + σ↑↓(2)Here, σ↑↑ (σ↑↓ ) is the cross section for protons collisions
with the parallel (antiparallel) transverse polarization.
ALT terms have been ignored as they are parity violating.
Non-zero AT T theoretically arises from partontransversity distributions, δf (x, Q2 ), which describe
the difference in the number density of partons withthe same and different polarization in a transversely
polarized proton. As the gluon is a massless spin 1
particle, δg(x, Q2 ) = 0. Therefore, the numerator in
Eq. 2 depends only on quark transversity. As bothquarks and gluons contribute to π 0 production, the denominator includes both quark and gluon interactions.
Thus, AT T is expected to be quite small.
In 2005, a short running period was taken withtransversely polarized beams specifically to constrain0
the systematic uncertainty from AπT T in the measure0
ment of AπLL . Experimentally, we actually measure
AT T =1N↑↑ − RN↑↓,
|P1 ||P2 | N↑↑ + RN↑↓

R=

L↑↑
.
L↑↓

(3)

where L is the integrated luminosity, R is the relative
∗1
∗2
∗3
∗4

Department of Physics, Stony Brook University
Brookhaven National Laboratory
RIKEN BNL Research Center
Department of Physics, Kyoto University- 81 -

References
1) S. S. Adler et al.: Phys. Rev. Lett. 91, 241803 (2001).
2) M. Togawa et al.: RIKEN Accel. Prog. Rep. 39, 198(2005).
3) A. Mukherjee et al.: hep-ph/0507023 (2005).

0

Ameas = (1 − ǫ)ALL + ǫAT T ,luminosity, P1 and P2 are beam polarizations and N is0
the particle yield. The measurement of AπT T is similar0
to that of AπLL , which is described in1) .
0
The results for AπT T are plotted in Fig. 1. The data
sample corresponds to a luminosity of 0.15 pb−1 andaverage polarization of 47%. A scaling uncertainty of
40%, resulting from a 20% per beam polarization uncertainty, has not been included in the data in Fig. 1.
0
As AπT T is consistent with zero for the entire pT range
0
measured, we assume a systematic uncertainty in AπLL0
of 0.075×δAπLL, where 0.075 is the ratio of longitudinal
to transverse luminosity times ǫ.
The theoretical expectation for AT T for p + p →π 0 + X has been calculated3) for the measured pTrange. Assuming maximal transversity, as defined by0
the Soffer bound,3) find AπT T <0.001 in the rapidity
range covered by PHENIX. Such a precise measurement would require a transversely polarized luminosityof 320 pb−1 , which is not currently expected.

π
ATT

One of the primary goals of the RHIC spin programis to measure ∆g, the gluon contribution to the spinof the proton, by measuring a double longitudinal spin
asymmetry, ALL , in the production of different probes
in polarized proton collisions. Due to large statistics
in pion production, and the high resolution electromagnetic calorimetry at PHENIX, the asymmetry in
π 0 production has offered a significant constraint on∆g 1) .
At RHIC, the stable beam polarization direction isvertical, and so the polarization must be rotated onto
the beam momentum axis at PHENIX. Small transverse polarization components remain, and have beenmeasured2) . This remaining transverse component isa background in our measured ALL :

0.4

0.3

PHENIX Preliminary

0.2

0.1

0

-0.1

-0.2
1

Scaling error of 40%
is not included.
2

3

4

5

6
7
pT (GeV/c)

Fig. 1. Azimuthally independent double transverse spin
asymmetry, AT T , in π 0 production during 2005 RHIC
running period with transversely polarized protons.
Due to small remaining transverse beam polarizations
in longitudinally polarized beams, AT T is a contamination in our measured asymmetry. A systematic uncer0
tainty of 0.075×δALL is applied to the measured AπLL .

RIKEN Accel. Prog. Rep. 40 (2007)

kT Asymmetry in Longitudinally Polarized pp Collisions at PHENIX
D. E. Fields,∗1,∗2 I. Younus,∗1∗1∗2

was used. In bunch shuffling, we randomly flip thebeam polarization signs for each event with a 50%
probability, and then obtain the ∆φ distributions forthe two helicity combinitaions. The mixed event background is obtained from the whole data disregarding
the helicity, and is kept the same for both helicity combinations. Since the mixed event background is used
to correct the correlation function for effects of limited
PHENIX azimuthal acceptance and for the detection
efficiencies, we don’t expect it to change with helicity. The results of the bunch shuffling indicate thatthe quoted errors on the fit parameters are correct.
Since any spin dependent effect should scale withthe polarization of each beam, all helicity differences
are scaled by the run-averaged beam polarization in
the blue and yellow beams, both taken to be 0.47. A
scale uncertainty of 40% is not shown on the figure.
We look
pat the kT helicity combination differences andfind ∆ hkT i = 670 ± 390 MeV/c to be large, but withlimited statistical significance.
χ2 / ndf

1.347 / 5
0.6719 ± 0.3874

p0

4

1 ∆( x-1 〈z 〉 〈k2 〉 )×(x ⁄ 〈z 〉) [GeV/c]
t
t i
T
PBPY

The history of theoretical interest in orbital angular momentum in hadrons can be traced to a paperby Chou and Yang1) describing hadronic matter current inside a polarized hadron. Later, Meng Ta-chunget al.,2) proposed two experiments to access hadronicmatter currents, one in semi-inclusive deep inelastic
scattering of unpolarized leptons on transversely polarized protons, and the second in the measurement of
the net pair transverse momentum of Drell-Yan pairs
in collisions of longitudinally polarized protons. The
latter lays the theoretical basis for this analysis.
We propose here a method to probe the spincorrelated transverse momentum of partons involved in
hard collisions of longitudinally polarized protons leading to jet events at PHENIX. The basic picture is that
if some part of the transverse momentum of partonsis correlated to the (longitudinal) spin direction, as it
would be in the case of orbital angular momentum,
then hard collisions involving these rotating partons
may lead to jets with more or less average transverse
momentum kT , depending upon the relative orientation of the spin directions and the centrality of the collision. Since, at present, there is no good experimental
tool to determine the collision centrality in p + p collisions, one must determine if the effect remains when
the impact parameter is undetermined. In2) , with asimple picture of the transverse spatial and momentum distributions, a net overall effect is still found.
PHENIX cannot measure the true jet axis as a direct
way to measure the pair transverse momentum. An alternative method has been developed3) that examinesthe π 0 -hadron azimuthal angle correlation to extract
the average pair transverse momentum on a statisticalbasis for two subsets of the data - like helicity collisions and unlike helicity collisions. The extracted average transverse momentum kT for the two sets arecompared as a measure of the helicity dependence of
the interacting parton transverse motion.
The correlation function is obtained by measuring the distribution of the azimuthal angle difference,∆φ = φt − φa , between π ◦ (triggered particle) andcharged hadron (associated particle). Whenever a π 0 is
found in the event, the real (dNreal /d∆φ) and mixed(dNmix /d∆φ) distributions are accumulated. Mixed
events are obtained by pairing a π 0 in an event with h±from another randomly selected event. The jet fragmentation transverse momentum jT and the partonic
transverse momentum kT can be extracted from thewidths of the peaks in the correlation function.
To check systematic errors, bunch shuffling method

PHENIX Preliminary
3

2

1

0

-1

-2
2

3

4

5

6

7

8

9

10

PTt [GeV/c]

Fig. 1. ∆p

hkT2 i (like- minus unlike-helicity combinations).

References
1) Chou, T. T. and Yang, Chen Ning, Nucl. Phys. B 107
1 (1976).
2) Meng, Ta-chung and Pan, Ji-cai and Xie, Qu-bing andZhu, Wei, Phys. Rev. D 40 769 (1989).
3) Adler, S. S. et al., Phys. Rev. D 74 072002 (2006).

University of New Mexico
RIKEN-BNL Research Center- 82 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Measurement of Transverse Single-spin Asymmetries with J/Ψ in√
Polarized p+p Collisions at s=200GeV
H. Liu∗1 and M. Liu∗2 for the PHENIX Collaboration

AN =1 σ↑ − σ↓
1 N ↑ − RN ↓=,↑↓Pb σ + σ
Pb N ↑ + RN ↓(1)

where Pb is the beam polarization, σ ↑ (σ ↓ ) is the production cross section, N ↑ (N ↓ ) is the J/Ψ yield fromup(down)-polarized bunches, and R = L↑ /L↓ is therelative luminosity measured with BBC(ZDC).
The inclusive J/Ψ sample is contaminated by otherbackground (mainly come from Drell-Yan process,open charm and light hadrons decay). The measured
J/Ψ
Aincl
is related to AN by
N
BG
Aincl
N − r · AN
,
1−r
q
BG 2
2
2
(δAinclN ) + r · (δAN )
J/Ψ
,
δAN =
1−r
J/Ψ

AN

=

(2)

(3)

where r is the background fraction, and ABG
is theN∗1∗2

New Mexico State University, Las Cruces, NM, USA
Los Alamos National Laboratory, Los Alamos, NM, USA- 83 -

0.3

PHENIX Preliminary (Run6)

0.25
0.2
0.15
0.1

J/ Ψ -> µ+µ-1
1.7 pb , Pol=56%<pT>=1.6GeV/c
Sys. Err

0.05
0
-0.05
-0.1
-0.15
-0.4

scale uncertainty of 20% not included

-0.3

-0.2

-0.1

-0

0.1

Fig. 1. AN of J/Ψ vs xF at|AN|max

The measurement of transverse single-spin asymmetries (AN ) enables us to probe the quark and gluon
structures of transversely polarized nucleons. Largetransverse single-spin asymmetries of up to 20% -√40%
were found for pions produced at a large xF ands=√
20 GeV1) and have been found to persist at s = 200
GeV during the STAR2) and BRAHMS experiments,
although they were expected to vanish according to
pQCD calculations at the leading order. A number ofpQCD based models have been developed to explain
this phenomenon. Among them are the Sivers effect3) ,the Collins effect4) , and the interference between quarkand gluon fields in the initial or final state5) .
At RHIC energy, heavy flavor production is dominated by gluon-gluon interactions. Thus, Collins effect has minimum impact on AN because the gluon’stransversity is zero. Therefore, the production of heavy
flavor particles in transversely polarized p+p collisions
in the PHENIX experiment offers a good opportunity
to gain information on gluon’s Sivers effect.
In this report, we present the first measurement of
the transverse single-spin asymmetry of J/Ψ in polarized p+p collisions at RHIC. The PHENIX muon
spectrometers have measured J/Ψ production throughthe J/Ψ → µ+ µ− channel at forward rapidities (1.2 <|η| < 2.4).
The transverse single-spin asymmetry AN can be determined by:AN[Spin, J/Ψ, Asymmetry]

0.2

√

0.3

0.4
xF

s = 200 GeV.

0.3

0.25

|AN|max for D hadrons
PRD70(2004)074025

0.2

gg
0.15

qq

0.1
0.05
0
-0.05
-0.1
-0.15
-0.8

-0.6

-0.4

-0.2

-0

0.2

0.4

0.6

0.8
xF

Fig. 2. AN vs xF in D meson production at pT = 1.5GeV/c√and s = 200GeV.

averaged background asymmetry. ABG
is obtainedNusing the like (unlike) sign dimuon pairs within 2.0
GeV< Mµµ < 2.5 GeV, and the like sign dimuon pairs
within 2.8 GeV< Mµµ < 3.5 GeV.
Preliminary result of J/Ψ AN vs xF from the 2006
RHIC run is shown in fig.1. Currently, there is no theoretical calculation of J/Ψ AN . However, there is aprediction of AN in D meson production at RHIC energy, as shown in fig.26) . The solid line shows |AN |max
when the gluon Sivers function is set to its maximum
and the quark Sivers function is set to zero, and thedashed line corresponds to the opposite situation. If
the asymmetry came from the initial state, then wewould expect AN in J/Ψ and D meson production to bevery similar. The fact that there is no sizable asymmetry observed in fig.1 indicates that our results disfavor
the maximum contribution of gluon’s Sivers function.
References
1) D.L. Adams et al.: Phys. Lett. B 264, 462-466 (1991);
A. Bravar et al.: Phys. Rev. Lett. 77, 2626-2629 (1996).
2) J. Adams et al.: Phys. Rev. Lett. 92, 171801 (2004).
3) D. Sivers: Phys. Rev. D 41, 83-90 (1990).
4) J.C. Collins: Nucl. Phys. B 396, 161-182 (1993).
5) J. Qiu et al.: Phys. Rev. D 59, 014004 (1999);
Y. Kanazawa et al.: Phys. Lett. B 478, 121-126 (2000).
6) M. Anselmino et al.: Phys. Rev. D 70, 074025 (2004).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Measurement of cross section and single transverse spin asymmetryof forward neutrons from pp collisions at RHIC-PHENIX
M. Togawa∗1, K. Aoki∗1 , K. Boyle∗2 , S. Dairaku∗1 , A. Deshpande∗2 , Y. Goto, K. Imai∗1 , N. Saito∗3 , J. Seele∗4
and K. Tanida∗1 for the PHENIX collaboration

∗1
∗2
∗3
∗4

Department of Physics, Kyoto University
Department of Physics, Stony Brook University, SUNY
J-PARC Office, High Energy Accelerator Research Organization (KEK)
Department of Physics, University of Colorado- 84 -

tudinal components were 98∼100% for both beams in
the longitudinal polarized pp period at 62.4 GeV.
0.9

P HE NIX preliminarys =30.6 G eV : IS R data
0.8

s =44.9 G eV : IS R data

0.7

s =52.8 G eV : IS R dataTFdσ/dx F | 0<p <0.11x [mb]C ros s s ec tion of forward neutron produc tion ( integrated in 0<p T <0.11x F (G eV /c ) )s =62.7 G eV : IS R data
0.6

s =200 G eV : P HE NIX data

0.5
0.4
0.3
0.2
0.1
0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

xF

Fig. 1. Cross section of the forward neutron production√
from pp collisions at s=200 GeV (Circles. Systematic
errors are plotted as gray boxes). Squares show the results from ISR with various center of mass energies. No
evidence for violation of xF scaling at this high energy.
Neutron as ymmetry x F dis tribution with neutron trigger & MinB ias

AN

Forward neutron production in pp collision has beenstudied and √provide intriguing results. In the ISR experiment at s=30.6 to 62.7 GeV in pp collisions, theneutron cross section in the very forward region (pT ∼0 GeV) has a peak structure at high Feynman-x (xF )and their cross sections scaled well with xF 1) . One possible explanation for these interesting results is givenby the one pion exchange model2,3) .
The Relativistic Heavy Ion Collider (RHIC) at the
Brookhaven National Laboratory (BNL) has been
operated
with polarized proton beams colliding at√
s=200 GeV for the spin program. In RUN2 (20012002), an unexpected large single transverse spin
asymmetry (AN ) of the forward neutrons was discovered in the 12 o’clock interaction point experiment4) .
The measured asymmetry may also be explained by
the pion exchange which is a spin flip interaction. The
forward neutron asymmetry can be a new tool for understanding the production mechanism.
Through 2003-2006, in the PHENIX experimenthas measured the forward neutrons using Zero-Degree
Calorimeter (ZDC) with a position-sensitive ShowerMax Detector (SMD)5) . They cover ±2.8 mrad of theforward and backward directions with 20% energy resolution for 100 GeV neutrons. Detector performancesand signal identifications have been studied by MonteCarlo simulations based on GEANT3 with PYTHIA
and single-particle event generators to obtain the crosssections and AN of neutrons.
The√ preliminary result of the neutron cross section
at s=200 GeV is plotted with the ISR results in Fig.
1. The PHENIX result is consistent with the ISR dataand no evidence for violation of xF scaling at this highenergy. In Fig. 2, the neutron AN is shown as a function of xF . A significant asymmetry can be seen in theforward (0<xF ) and the curve is flat. The physics implications of this result are currently being discussed.
In the running period, forward neutron asymmetry
is a very useful observable quantity for evaluating thespin direction of the proton beam at the collision point.
It has been successful throughthe 2003-2006 RUN pe√
riod6) . In RUN 2006, s=62.4 GeV polarized pp col7)
lision was performed for√ the first time . A significant
finite value, similar to s=200 GeV, was obtained forthe forward neutron asymmetry and the evaluation ofspin direction was successfully accomplished. Longi-

0.1

S c aling error of 20%
is not inc luded.

P HE NIX preliminary

S tatis tic al error is c orrelated
due to unfolding.

0.05

s ys tematic error band
0

-0.05

-0.1
-1

0.03x F <pT <0.22x F (G eV /c )
-0.8

-0.6

-0.4

-0.2

-0

0.2

0.4

0.6

0.8

1

xF

Fig. 2. Single spin asymmetry of neutron production from√pp collisions at s=200 GeV. A significant asymmetry
can be seen in the forward region (0<xF ), and is flat asa function of xF .

References
1) W. Flasher et al., Nucl. Phys. B109 (1976) 347.
2) B. Kopeliovich et al., Z. Phys. C73 (1996) 125.
3) U. D’Alesio and H.J. Pier, Eur. Phys. J. A7 (2000) 109.
4) A. Bazilevsky et al., hep-ex/0610030 (to be in Phys.
Lett. B).
5) C. Adler et al., Nucl. Instr. And Meth. A470 (01) 488.
6) A. Deshpande et al., RIKEN Accel. Prog. Rep. 37 (04)246. ; M. Togawa et al., RIKEN Accel. Prog. Rep. 39(06) 198.
7) K. Aoki et al., RIKEN Accel. Prog. Rep. 40 (07).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Spin-dependent fragmentation function measurements at Belleexperiment
R. Seidl,∗1 M. Grosse-Perdekamp,∗1 K. Hasuko and A. Ogawa,∗2∗1∗2

University of Illinois
Brookhaven National Laboratory- 85 -

0.15

0.2<z1<0.3

0.3<z1<0.5

0.5<z1<0.7

0.7<z1<1

0.1
0.05
0
-0.05
A0

The Belle experiment1) at the asymmetric e+ e− collider KEKB2) at Tsukuba, Japan, is mainly dedicatedfor studying CP violation in B meson decays. It is
tuned to the Υ(4S) resonance at 10.58 GeV, whereas
background studies are performed at 10.52 GeV. The
first results on the fragmentation of polarized lightquarks into pions obtained on a data set of 29.1 fb−1have been published6) . The inclusion of the full
data set of 547 fb −1 will be presented.
The Collins effect3) occurs in the fragmentation ofa transversely polarized quark with polarization Sqtransverse to its 3-momentum k into an unpolarizedhadron of transverse momentum Ph⊥ with respect tothe original quark direction. The Collins function
CMS2h
H1⊥q (z, Ph⊥), where z = 2E
Q is the fractional energy the hadron carries in the center of mass system,
causes a sin(φ) modulation in the azimuthal distribution of the hadron yields around the original quark
momentum axis. φ is the azimuthal angle between
the transverse momentum of the hadron and the plane
defined by the quark spin and its momentum. In
e+ e− hadron production, the Collins effect can beobserved by correlating the fragmentations of quark
and anti-quark in opposing hemispheres. The combination of two hadrons from different hemispheres in
two-jetlike events, with azimuthal angles φ1 and φ2 ,results in a cos(φ1 + φ2 ) modulation of the observed
di-hadron yield. In the CMS, these azimuthal angles
are defined between the transverse component of thehadron momenta with regard to the jet axis n̂ and theplane spanned by the lepton momenta and n̂. Following Ref.4) one either computes the azimuthal angle of each pion relative to the jet axis which results
in a cos(φ1 + φ2 ) modulation or one calculates theazimuthal angle (φ0 ) relative to the axis defined by
the 2nd pion which results in a cos(2φ0 ) modulation.
We measure the normalized yields N (βα )/hN0 i, whereN (βα ) denotes the number of hadron pairs in the binsof either β0 = 2φ0 or β12 = φ1 + φ2 and hN0 i is theaverage number of hadron pairs in the whole angle interval. The main background, producing similar azimuthal asymmetries as the Collins effect, is the radiation of soft gluons. This gluonic contribution is proportional to the unpolarized FF and is independent of thecharge of the hadrons. Consequently, taking the ratioof the normalized distributions for unlike-sign over likesign pairs the gluonic distributions drop out in leading

A0[QCD, e+ e− annihilation, fragmentation, transversity]

0.15
0.1
0.05
0

-0.05
0.2

0.4

0.6

0.8 0.2
z2

0.4

0.6

0.8

z2

Fig. 1. Light quark (uds) A0 asymmetries as a function ofz2 for the 4 z1 bins. The UL data is described by thetriangles, its systematic error being the top error band
while the UC data is described by the squares and its
systematics by the lower error band.

order:Rα :=. N (β )N (βα )
αhN0 i unlikesign hN0 i likesign,(1)

A similar expression for the ratio of unlike-sign over all
charged pion pairs7) also exists. These double ratios
are then fit by the sum of a constant term and a cosine
modulation Rα = Bα +Aα cos(βα ). The reconstructionof azimuthal asymmetries was tested by a Monte Carlosimulation. The results for the A0 results are shown
as a function of the fractional energies in Fig. 1. A
significant rising asymmetry can be observed.
References
1) A. Abashian et al.(Belle): Nucl. Instrum. Meth. A479
(2002) 117.
2) S. Kurokawa, E. Kikutani: Nucl. Instrum. Meth. A499
(2003) 1.
3) J. C. Collins: Nucl. Phys. B396 (1993) 161.
4) D. Boer, R. Jakob, P. J. Mulders: Phys. Lett. B424
(1998) 143.
5) A. Airapetian et al.(Hermes) Phys. Rev. Lett.94(2005)012002.
6) R. Seidl, et al.(Belle): Phys. Rev. Lett. 96(2006):232002.
7) A. Efremov, K. Goeke and P. Schweitzer: [arXiv:hepph/0603054].

1

RIKEN Accel.
Accel. Prog.
RIKEN
Prog. Rep.
Rep.3940 (2006)(2007)

Measurement of AN and AN N in pp Elastic Scattering in the CNI
Region with a Polarized Atomic Hydrogen Gas Jet Target
H. Okada,∗1,∗2 G. Bunce,∗2,∗3 K.O. Eyser,∗4 and I. Nakagawa.∗1[Elastic scattering, spin, coulomb nuclear interference]

References
∗1
∗2
∗3
∗4
a)

1) N.H. Buttimore et al., Phys. Rev. D 59, 114010 (1999).
2) T.L. Trueman, RHIC Spin Note, September 27, (2005),
hep-ph/0604153.
3) H. Okada et al., Phys. Lett. B 638, 450 (2006);
H. Okada, Doctororal Thesis, July (2006).
4) A. Zelenski et al., Nucl. Inst. and Meth. A 536, 248(2005);
T. Wise et al., Nucl. Inst. and Meth. A 559, 1 (2006).

AN

0.07
0.06

0.04
0.03
0.02
0.01
0
10-3

- 86 -

10-2

2-t (GeV/c)√
Fig. 1. The filled and open circles are measured at s =6.7 GeV and 13.7 GeV, respectively. The errors on thedata points are statistical. The lower bands represents
the total systematic errors. The solid and dashed lines
are the function without allowing for φhadcontribution
5√
to AN for these s, respectively.

0.06
s=6.7 GeV
0.04

s=13.7 GeV

0.02
0
-0.02
-0.04
-0.06 -3
10

RIKEN, Wako, JAPANBrookhaven National Lab., Upton NY, USA
RIKEN BNL Research Center, Upton NY, USA
University of California, Riverside CA, USA
The details of experimental setup are described in3,4) .
These references contain a complete list of authors of thecollaboration.

s=6.7 GeV
s=13.7 GeV
No had. func. s = 6.7 GeV
No had. func. s = 13.7 GeV

0.05

ANN

Precise measurements of the single and double spin
asymmetries, AN and AN N , in proton-proton elastic scattering in the region of four-momentum transfer squared 0.001 < −t < 0.032 (GeV/c)2 have been
performed using a polarized atomic hydrogen gas jettarget and the RHIC proton beam in 2004 a) .√We took
data for two beam momenta
at 24 GeV/c ( s = 6.7√
GeV) and 100 GeV/c ( s = 13.7 GeV).
This −t region is known as the Coulomb Nuclear
Interference (CNI) region. The interference of theelectro-magnetic spin-flip amplitude with a hadronic
non spin-flip amplitude is predicted to generate ANof few %, peaking at −t ' 0.003 (GeV/c)21) , and thepresence of a hadronic spin-flip amplitude (φhad5 ) would
modify this calculable prediction. AN N is thought tobe sensitive to the hadronic double spin-flip amplitude2)(φhad
but there is no solid theoretical prediction for2 )its energy dependence nor magnitude.
Fig. 1 and Fig. 2 display the results of AN and AN N
in the the CNI region as a function√ of −t. The filled
and empty circles are results at s = 6.7 GeV and13.7 GeV3) , respectively. The errors on the data points
are statistical. The lower bands represent the total systematic errors. The solid and dashed lines in Fig. 1 are
the function without
allowing for φhadcontribution to5√√
AN for these s, respectively. AN at s = 13.7 GeV
are consistent with the dashed line (χ2 /ndf=13.4/14).
On the other hand, although
the accuracy is statisti√cally limited, AN at s = 6.7 GeV are not consistent
with the solid line (χ2 /ndf=35.5/9). This discrepancy√
implies the presence of φhads have5 . AN N for theseno clear −t dependence and the average values are consistent with zero within the uncertainty of 1.5 σ.
In summary, AN and AN N results provide experimental knowledge √of poorly known φhadand φhadat2
5
had
these energy. The s dependence of φ5 is provided
by AN results. The theoretical interpretation is under
way in order to have a comprehensive understanding
had
had
of
√ φ2 and φ5 . In addition, the analysis of AN at
s = 7.6 GeV which were measured
in 2005 is under√
way and will give us the third s point data.

10-2

2

-t (GeV/c)√
Fig. 2. The filled and empty circles are measured at s =6.7 and 13.7 GeV. The errors on the data points are
statistical. The lower bands represents the total systematic errors.

1

RIKEN Accel. Prog. Rep. 40 (2007)

Absolute beam polarization measurements at RHIC in 2005

Accurate knowledge of the beam polarization is essential in the spin program at the Relativistic Heavy
Ion Collider (RHIC). Measurements of beam polarizations utilize scattering processes. Fast measurements
are based on proton-carbon scattering off carbon fiber
targets1) , for which the necessary normalization is provided from elastic proton-proton scattering with a polarized hydrogen gas jet target.
The jet polarimeter is located at one of the collision
points in the RHIC accelerator. It consists of a polarized hydrogen atomic jet target with a Breit-Rabi
polarimeter2) and a set of six separate detectors eachof 16 silicon strips. The hydrogen molecular content
has been determined and is removed from the effective
polarization Ptarget = (92.4 ± 1.8)%.
The detectors are centered with respect to the interaction point of the proton beam with the target. In
this geometry, eight downstream strips on each detector can detect elastically scattered recoil protons when
one RHIC beam hits the target. In routine operation,
one of the two RHIC beams is displaced, so the respective eight non-signal strips can be used to estimate thebackground fraction below the elastic signal peak.
The silicon detectors are read out with waveform
digitizers, running at 420 MHz. Two α-sources areused for energy calibration of the ADC signal. Additional time of flight offsets are individually adjusted foreach strip using the pronounced proton signal. Particle
identification is based on time of flight and energy.
The determination of the RHIC beam polarization
is based on a set of four vertical polarization combinations of target and beam. Yields are combined toseparate beam and target asymmetries. The beam polarization Pbeam is then derived from the ratio of theasymmetries ǫbeam and ǫtarget and a known Ptarget :Pbeam = −ǫbeam (TR )· Ptarget .
ǫtarget (TR )(1)

While the kinematic correlation of the detector strip
position and the recoil energy TR suppresses the background outside of the considered energy range, Pbeam
University of California, Riverside, USA
ITEP, Moscow, Russia∗3 University of Geneva, Switzerland∗4 Brookhaven National Laboratory, USA∗5 RIKEN BNL Research Center, USA∗6 Yale University, USA∗7 University of Wisconsin, USA∗8 KEK, Japan∗9 RIKEN, Japan∗10 University of Erlangen, Germany∗11 Kyoto University, Japan∗12 Indiana University, USA∗1∗2

asymmetry ∈K.O. Eyser,∗1 I. Alekseev,∗2 A. Bravar,∗3 G. Bunce,∗4,∗5 S. Dhawan,∗6 R. Gill,∗4 W. Haeberli,∗7 H. Huang,∗4
O. Jinnouchi,∗8 Y. Makdisi,∗4 I. Nakagawa,∗9,∗5 A. Nass,∗10 H. Okada,∗11,∗9 E. Stephenson,∗12 D. Svirida,∗2
T. Wise,∗7 J. Wood,∗4 A. Zelenski,∗4
0.05
target asymmetry
beam asymmetry
0.04

0.03

0.02

0.01

0

1

2

3

4

5

6
T R (MeV)

Fig. 1. Target and beam asymmetries as functions of TR .

has been determined for different TR before averaging.
Figure 1 shows the typical peak of the asymmetries at
TR ≈ 1.5 MeV from a subset of the data. The ratio between 1.0 and 4.0 MeV is used to determine the beampolarization, lower and higher recoil energies are discarded due to asymmetric acceptance and background.
Figure 1 compares the data with the expected shapeof the analyzing power AN from a formal descriptionin terms of helicity amplitudes scaled with target andbeam polarizations.
In 2005, beam polarizations of nearly 50% have beenmeasured in RHIC with good statistical accuracy. Systematic errors were estimated from background yields
of empty target runs and subdivision with respect toseparate bunches in the accelerator. No significant polarization dependence has been observed in the background. Other checks included many thousand repetitions of random assignments to the polarization directions of bunches and calculating the resulting asymmetries. The effect on the determination of the beam polarization has been estimated by purposefully widening
the signal region on the detectors, this way increasing
the background by factors of up to four and consecutively lowering the beam and target asymmetries. The
ratio of asymmetries, on the other hand, is largely unaffected by the growing background and an upper limitof ∆P/P = 1.1% has been assigned to the beam related background. This does not include the molecular
content in the jet target.
References
1) I. Nakagawa, this publication (2006).
2) H.G. Gaul and E. Steffens, NIM A316, 297 (1992).

- 87 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Stability for Run05 Operation of pC-Polarimeter
I. Nakagawa, I. Alekseev,∗1 A. Bravar,∗2 G. Bunce,∗3∗4 S. Dhawan,∗5 K.O. Eyser,∗6 R. Gill,∗3 W. Haeberli,∗7
H. Huang,∗3 O. Jinnouchi,∗8 Y. Makdisi,∗3 A. Nass,∗3 H. Okada,∗9 E. Stephenson∗10 D.N. Svirida,∗1 T. Wise,∗7
J. Wood,∗3 and A. Zelenski∗3∗1

Institute for Theoretical and Experimental Physics, Russia
University of Geneva, 1205 Geneva, Switzerland∗3 Brookhaven National Laboratory, USA∗4 RIKEN-BNL Research Center, BNL, USA∗5 Yale University, USA∗6 University of California, Riverside, USA∗7 University of Wisconsin, USA∗8 KEK∗9 Kyoto University∗10 Indiana University Cyclotron Facility, USA∗2make the efficiency function complex.
To avoid such a complexity that cannot be sufficiently controlled, here we consider net energy correction by introducing “effective dead-layer thickness”,
which can be determined from a fit to the measured
timings and pulse height using the kinematic correlation between time-of-flight and carbon energy. A timeoffset with respect to a beam clock and the effective
thickness of the dead-layer are treated as free parameters.
Eﬀective DeadLayer µg/cm

2

DeadLayer History (Blue)

60

50
40

30

20

Flattop
6800

6900

7000

6900

7000

7100

7200

7100

7200

Fill Number

7300

2

DeadLayer History (Yellow)

Eﬀective DeadLayer µg/cm

The Relativistic Heavy Ion Collider (RHIC) at BNL
provides a unique opportunity to collide polarized protons. The decompsition of nucleon spin in terms ofthe contributions from its constituents has been studied using various observed asymmetries. The 2005 run(RUN05) was the first extended operation of the polarized RHIC-pp program. During the running period,
continuous studies were performed to improve the performance characteristics of an accelerator, for example,
intensity, emittance, and backgrounds, whereas polarization measurements were regularly executed every 2
to 3 hours for both beams using RHIC pC-polarimeters
1). The stability and reliability of the polarization
measurements under various beam/detector conditions
are the major concern in evaluating the average polarization, which provides normalization for experiments.
One of the dominant sources of uncertainties in pCpolarimetry has been the absolute energy determination for low-energy recoiling carbon ions2) .
We detect elastically recoiling carbon ions at a scattering angle of 90◦ in the kinetic energy E range of
400 keV < E < 900 keV using six silicon detectors mounted at azimuth angles of 45◦ , 90◦ and 135◦
on both sides of the beam axis. Each detector issegmented into 12 strips (72 strips in total). These
low-energy carbon ions stop at very shallow depths(< 1.3 µm) in a silicon sensor and the response of
the detector is sensitive to the surface structure of thesilicon. A 400 keV carbon ion loses about 1/3 of its
energy in a typical dead region followed by a partiallyinefficient charge collection region before it reaches afully active region. There are two main difficulties incorrecting for the unobserved energy loss. First, wehave been unable to separate the energy-dependent energy loss in the dead-layer from charge collection inefficiency near the surface region. Secondly, it is nontrivial
to model the inefficiency as a function of depth. The
charge collection efficiency is initially characterized by
the Landau distribution of the implanted Boron atoms
in the doping process. In reality, the efficiency depends
on many other conditions, such as the magnitude of radiation damage, and event rate. These dependencies

60

50
40

30

Flattop20
6800

Fill Number

7300

Fig. 1. Stability of effective dead-layer thickness averaged
over 72 strips plotted as function of fill number for blue
(top) and yellow (bottom) polarimeters.

The estimated effective dead-layer thicknesses inµg/cm2 units averaged over 72 strips are shown in
Fig. 1. Data points represent individual measurements
performed at a beam energy of 100 GeV. As illustrated
by the solid line in the figure, the effective thicknessof the dead-layer increases with time. The increase inof the inefficiency can be interpreted as the deteriorated charge collection efficiency due to the accumulated radiation damage in the surface region. Besides
the fitting error, the cause of varying effective deadlayer thickness is unknown, except for a minor averagerate dependence (data points in the figure are alreadycorrected for this). These fluctuations are thus accounted for by uncertainties in absolute energy determination. Considering 1σ of the fluctuations in effective dead-layer thickness, (∼ 3 µg/cm2 ), corresponds
to a few percent uncertainty in beam polarization.
References
1) I. Nakagawa et al.: RIKEN Accel. Prog. Rep. 39, 1862005, and references therein.
2) I. Nakagawa et al.: RHIC/CAD Accelerator Physics
Note, Vol.275 (2007).

- 88 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Absolute luminosity determination using vernier scan technique at
PHENIX
Y. Goto and R. Bennett∗1 for the PHENIX Collaboration

where vertex is the vertex selection efficiency obtainedby the vertex reconstruction analysis of the BBC detector.
In the 2001 – 2002 run of RHIC, the BBC trigger
cross section was determined to be 21.8 ± 0.9 (2.8)
mb at a 68.5% (95%) confidence level with an absolute
error of 0.7 mb on the basis of three scans. Because
this result was obtained from only three scans, the remaining issue is a better systematic understanding to∗1

Department of Physics, Stony Brook University- 89 -

References
1) S. S. Adler et al.: Phys. Rev. Lett. 91, 241803(2003): Phys. Rev. Lett. 92, 051802 (2004): arXiv:hepex/0609031: A. Adare, arXiv:hep-ex/0611020.
2) A. Drees and Z. Xu: PAC-2001-RPAH116 Presented
at IEEE Particle Accelerator Conference (PAC2001),
Chicago, Illinois, 18-22 Jun 2001.

400

horizontal scan

400

350

350

300

300

250

250

200

200

150

150

100

100

50

50

0
-1500-1000 -500 0

vertical scan

Hz

Here σxv and σyv are the transverse widths of beam overlap as measured by vernier scans in the horizontal andvertical directions respectively, and “crossings” means
pairs of colliding bunches in the PHENIX interaction
region. The BBC trigger cross section is the ratio of
BBC trigger rate when the beams are overlapping maximally (Rmax ) to the effective machine luminosity observable using the BBC trigger with the collision vertex
selection:
Rmax
σBBC =,(2)
Lmachine · vertex

achieve smaller systematic uncertainties.
Since the 2003 run, we have recorded the number of
BBC-trigger events in each bunch crossing using a special crossing-sorted scaler, the so-called GL1P scaler(Global Level-1 physics scaler), at PHENIX during
vernier scans. The live time of the BBC trigger ineach crossing is normalized by the live-time clock also
recorded in the GL1P scaler. With this crossing-sorted
data, we can use each bunch crossing as one piece ofvernier scan data, and calculate the machine luminosity with eq.(1) without the summation of crossings andthe BBC trigger cross section with eq.(2) in each bunch
crossing. Figure 1 shows measured transverse profilesof the beam overlap in each crossing obtained by horizontal and vertical scans. The distances between two
beams (abscissa of the figure) are provided by the beam
position monitors of the RHIC accelerator. The widthsof these profiles determined by the horizontal and vertical scans are σxv and σyv , respectively. In the 2005
run and the 2006 run, more than ten vernier scans
were performed. Using the crossing-sorted data, we
can study the effects of varying each bunch crossing.
Using multiple vernier-scan data, we can study othereffects from the accelerator conditions fluctuating ineach RHIC store, e.g., nonzero crossing angle, transverse and longitudinal bunch shapes, intensity, and theblow-up of the beam. The final analysis is underway.

Hz

For any absolute cross-section measurement at
PHENIX1) , we require an absolute integrated luminosity determination. Absolute luminosity (L) is determined from the number of events triggered by thebeam-beam counter (BBC) of the PHENIX detector(NBBC ) using an absolute calibration of the BBC trigger cross section (σBBC ): L = NBBC /σBBC . The
BBC trigger is a minimum-bias trigger of the PHENIX
trigger system and requires that the collision vertex iswithin 30 cm of the center of the interaction region.
The BBC consists of two detectors located on eitherside of the colliding beam along the beam line at ±1.44m from the nominal interaction point and covers thepseudorapidity range ±(3.0–3.9) and the full azimuthal
angle. The vertex is reconstructed from the differencein the arrival times of particles at two BBC detectors.
The absolute calibration of the BBC trigger crosssection is obtained via the vernier scan (or van derMeer scan) technique.2) In a scan, the transverse profile of the beam overlap is measured by sweeping one
beam across the other in steps while monitoring BBC
trigger rate. This information, the bunch intensities of
the two beams as provided by the wall current monitorsof the RHIC accelerator (Nb and Ny ), and the revolution frequency for one bunch in the beam (fbeam ) areused to compute machine luminosity:
Xf·Lmachine = beam
(Nb · Ny )i .
(1)vv
2πσx σycrossings

500 10001500 20002500
micron00500 1000 15002000 250030003500
micronFig. 1. Transverse profiles of beam overlap in each bunch
crossing by horizontal (left) and vertical (right) scans.

1

RIKEN Accel. Prog. Rep. 40 (2007)

Data produc tio n for RHIC-PHE NIX ex perime nt
Z. You䟼1, J. Seele䟼2, H. Torii䟼3, Y. Mao䟼1, S. Yokkaichi, S. Kametani, Y. Watanabe, Y. Goto for the PHENIX collaboration
1

Overview

The data production for the PHENIX experiment at
RHIC (Relativistic Heavy Ion Collider) has been
performed at CCJ1-4) (RIKEN Computing Center in Japanfor RHIC5) physics) since 2002. In 2005-2006, the
PHENIX run5 p+p data production was performed at
CCJ and run6 p+p data production began in late 2006.
2

Run5 data production

In run5, RHIC provided PHENIX with polarized p+p
collisions at √s=200GeV from April to July 2005.
During this period, the raw data was transferred fromBNL (Brookhaven National Laboratory) to CCJ
concurrently as it was taken. The transfer was completed
on June 26th, 2005. Over 260 TB raw data wastransferred in 80 days using GridFTP7), with an average
speed of 40MB/sec. HPSS8) at CCJ is used to store theraw data and also the DSTs (Data Summary Tape) whichcontain the reconstructed data made during production.
The first version of run5 p+p production was
performed from June to September in 2005 by H.Torii etal9). 16TB of nDSTs (nano Data Summary Tape) were
produced and stored in HPSS at RSCC (RIKEN Super
Combined Cluster). They were also transferred to dCacheat RCF10) (RHIC Computing Facility), a mass data
storage system.
The second version of run5 p+p production began in
April 2006 and ended in September 2006, as is shown in
Fig.1, with Linux system and the PHENIX libraries
upgraded. 128 PC nodes (dual Xeon 3.06 GHz/2GB
memory/100 GB local disk) at RSCC that are specificallyassigned to CCJ were used for this production. 904
longitudinally polarized runs with good calibrations weresuccessfully produced. The nDST files from 10 PRDFs(PHENIX Raw Data Format) are aggregated into fewer
files for analysis and are then stored at HPSS. The
production rate was maintained at approximately
50MB/s.
The second version of production is a full and final
production for run5. All 28 flavors of nDSTs withdifferent triggers were produced. The total size of the
final nDST files is 38TB; the data is stored in HPSS at
CCJ. Like the first version of production, they aretransferred to dCache at RCF at BNL using bbftp11). The
average transfer speed obtained was 6MB/s. Details of
production
are
shown
on
the
web
page:
http://ccjsun.riken.go.jp/~phnxreco
䟼1
䟼2
䟼3

School of Physics, Peking University, China
Department of Physics, University of Colorado
Hiroshima University

Fig. 1. The PHENIX run5 p+p daily data processing
speed and data accumulation.
3

Run6 data production

During the run6 running period (March 2006 throughJune 2006), RHIC provided polarized p+p collisions at√s=200GeV to the PHENIX experiment. Two modes ofcollisions were used: one where the polarizations of thebunches were transverse to the beam momentum and one
where the polarizations were longitudinal to the beam
momentum. A total luminosity of 2.7pb-1 was taken in
the transverse mode and 7.5pb-1 in the longitudinal mode.
This compares with 3.78pb-1 taken in the longitudinalrunning in run5. The size of the raw data set isapproximately 320TB. The raw data was transferred fromPHENIX to CCJ using GridFTP. The data wastransferred to CCJ in near simultaneity to the data being
taken by PHENIX.
The longitudinal data set will be produced at CCJ
and the transverse data set will be produced at RCF. The
data will be processed at CCJ in a similar manner to therun5 production though with upgraded software for boththe HPSS system and the PHENIX libraries.
The production began in late 2006 and proceeded
into 2007. The data will then be transferred back to RCF
using GridFTP.
References
1) http://ccjsun.riken.go.jp/ccj/
2) S. Yokkaichi et al.: RIKEN Accel. Prog. Rep. 37, 257 (2004).
3) Y. Watanabe et al.: RIKEN Accel. Prog. Rep. 36, 262 (2003), T.
Ichihara et al.: RIKEN Accel. Prog. Rep. 35, 236 (2002).
4) S. Yokkaichi et al.: RIKEN Accel. Prog. Rep. 38, 247 (2005).
5) http://www.bnl.gov/rhic6) http://www.phenix.bnl.gov7) http://www.globus.org/datagrid/gridftp.html
8) http://www.hpss-collaboration.org/
9) H. Torii et al.: RIKEN Accel. Prog. Rep. 39, 220 (2006).
10) http://www.phenix.bnl.gov/RCF11) http://doc.in2p3.fr/bbftp/- 90 -

RIKEN Accel. Prog. Rep. 40 (2007)

Development of Nose Cone Calorimeter in PHENIX Forward Region
I. Nakagawa, E. O’Brien,∗1 V. Dzhordzhadze,∗2 D. Karmanov,∗3 E. Kistenev,∗1 Z. Li,∗1 A. Litvinenko,∗4
M. Merkin,∗3 V. Peresedov,∗4 R. Seto,∗2 A. Taketani, A. Sukhanov,∗1 V. Volkov,∗3 A. Voronin,∗3 V. Vrba,∗5 andL. Zolin∗3
The present baseline detector of PHENIX measuresmuons in two muon spectrometers located forwardof mid-rapidity and measures hadrons, electrons, andphotons in two central spectrometer arms, each ofwhich covers 90◦ in azimuth and 0.35 units of rapidity. The nose cone calorimeter1) (NCC) will extend
the rapidity coverage for hadronic and electromagnetic
signatures by upgrading the functionality of PHENIX
muon spectrometers to include photon and jet measurement capabilities. The forward production of inclusive jets, direct photons or Drell-Yan pairs at a large
xF in nucleon-ion collisions at RHIC will provide a
new window for the observation phenomena expected
at high parton number densities. Also, in conjunction with the muon spectrometer, the NCC will enable
isolation cuts for the study of W bosons to measure
antiquark spin structure functions.
So
uth

Mu
on

Central Magnet
Ma

gn

rth
No

et

Mu

on

M

t
ne
ag

NCC

ZDC SouthZDC North

MuID

MuID
MuTr

South

Side View

calorimeter depth of ∼ 40X0 . To that effect, it is longitudinally segmented into a relatively shallow electromagnetic compartment (16 X0 , two depth segments)
and a near 1-absorption-length-deep leakage segment(hadronic compartment), as shown in Fig. 2. The energy resolution is limited by the sampling fluctuations
in silicon readout layers, which are interleaved between
the Tungsten/Lead absorber plates.
Stripixel readout

Tungstenabsorber

Pad readout

Pb absorber

Cu skinFig. 2. Longitudinal structure of NCC.

As shown in Fig. 3, the NCC has a circular geometrical coverage within a 50 cm radius corresponding to a
forwad rapidity range from 0.9 to 3.5. The calorimeteris built of 20 pad-structured silicon layers organized
into towers in readout and two strip-structured silicon layers (pixelated strips2) ) used to track individual
charged particles and resolve close showers. The padsize chosen for NCC is 1.5 × 1.5 cm2 , and the strip
size is 0.5 × 0.5 mm2 .

North

Fig. 1. Side view of PHENIX detector with nose cone
brasses, which will be replaced by NCC pairs.

The NCCs are located 40 cm from the nominal
collision point on both the north and south poles of
the PHENIX central magnet as shown in Fig. 1 The
NCCs are limited to a depth of about 20 cm, whichis the depth of the present brass nose cones (hadron
absorber), that will be replaced by this device. The
NCCs are a combination of highly segemented electromagnetic and hadronic compartments supplemented
with high-resolution position detector located downstream of the active converter (at 2X0 , preshower
detector) to count photons, and at a shower max
position to measure decay asymmetries. The NCC
distinguishes between electromagnetic and hadronic
showers, measuring shower development over a total
∗1
∗2
∗3
∗4
∗5

Fig. 3. 3-dimentional mechanical rendering of NCC.

The optimization of the deatiled design and the construction of the prototype tower with a full longitudinal structure are underway. The first NCC unit isscheduled to be installed and comissioned in 2010.
References
1) PHENIX proposal for a Nose Cone Calorimeter (2006).
2) Z. Li, Nucl. Inst. Meth. A518, 738 (2004).

Brookhaven National Laboratory, U.S.A.
University of California at Riverside, U.S.A.
D.V. Skobeltyn Institute of Nuclear Physics, Russia
Joint Institute for Nuclear Research, Russia
Institute of Physics, Academy of Sciences of the Czech Republic, Czech- 91 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Development of a Trigger for High-pT Charged Pions for the
PHENIX Detector at RHIC
D. Kawall,1,2
The determination of the polarized gluon distribution function, ∆g(x), of the proton is a major objective of the PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC)1) . Currently ∆g is sopoorly known that even its sign has not been determined conclusively.
Measurements of the beam helicity dependence inthe production of various ﬁnal states √from collisionsof like- and unlike-helicity protons at s = 200 GeV
can be analyzed to shed light on ∆g(x). Charged pions are an interesting ﬁnal state to consider since itis expected that if ∆g(x) > 0 then the double helicity asymmetry in longitudinally polarized proton col+−X
pp→π 0 X
X
lisions App→π> ALL> App→πfor pions
LL
LL
whose pT are above several GeV/c.
Charged pions above a few GeV can ﬁre some of
the level-1 triggers in the PHENIX central arms, butwith low eﬃciency. Examining these triggers has led
to a promising, but poor statistics measurement of
±
X 2)
App→π
. The reason for this is that all level-1
LL
triggers currently require a hit in the Pb-glass or Pbscintillating ﬁber electromagnetic calorimeters with aminimum energy deposit of 800 MeV. This is morethan double what a minimum ionizing particle would
leave. The calorimeters are ≈ 1 nuclear interaction
length, so the probability that a charged pion will passthrough without interacting is of the order of 40%,and the probably it leaves less than 800 MeV is evengreater. The combination of low eﬃciency and highsusceptibility to background suggests that other approaches to triggering be considered.
One such approach is to incorporate informationfrom the new Hadron Blind Detector (HBD)3) recently
installed in the PHENIX interaction region. The HBD,
which is now the ﬁrst detector outside of the beampipe, is essentially a windowless Cherenkov detector
with a 50 cm long radiator of CF4 at atmosphericpressure (n ≈ 1.00046), a CsI photocathode and threestages of Gas Electron Multipliers (GEMs). The incorporation of a mesh at high voltage above the photocathode prevents the ampliﬁcation of electrons produced by ionizing particles, rendering the detector
blind to charged pions below the Cherenkov thresholdof about 4.6 GeV/c. However, the detector is sensitiveto π ± above the threshold.
The ALL measurement of π ±2) detected π ± by looking for a hit in the calorimeter linked by a charged particle track to a hit in the the Ring Imaging Cherenkov∗1∗2

RIKEN-BNL Research Center, Brookhaven National Laboratory, USA
Department of Physics, University of Massachusetts, USA

Fig. 1. Beam’s eye view of the PHENIX, showing in red thetracks from 6 GeV/c π ± on the left, and 1 GeV/c π ±on the right. The HBD is shown in blue in the center.

(RICH)4) . The latter has a threshold for charged pions of just under 5 GeV/c, so the ALL measurement
could be made for charged pions with a pT > 5 GeV/c.
This technique suﬀers because the RICH is susceptible to electrons coming from photons converted elsewhere in the detector. Also, charged hadron tracks canbe wrongly associated with the RICH ring, leading tobackgrounds in the ALL measurement.
The proposed new trigger involves a coincidence between hits in the HBD and RICH. This trigger shouldﬁre on π ± with pT > 5 GeV/c with high eﬃciency,
and should be clean (i.e. have a large rejection factor
of unwanted events). Such high pT charged pions bend
very little in the magnetic ﬁeld of PHENIX (see simulation in Fig. 1) so a hit in the HBD at a particular
azimuthal angle can only be associated with hits in asmall range in azimuth in the RICH. Low energy electrons and other backgrounds bend much more in theﬁeld and can be rejected by incorporating a lookup table in an FPGA which links hits in the HBD with anallowed range of hits in the RICH.
Currently this triggering scheme is being analyzed
for its eﬃciency and rejection power. A large scale
simulation of 5 million high pT π + and π − events in the
PHENIX detector is underway. From this, we hope todevelop the lookup table to be incorporated at level-1.
If the trigger is too noisy, we can always form a triple
coincidence with the calorimeter, with at least a 50%
loss in eﬃciency but a substantial gain in rejection.
References
1) G. Bunce et al., Ann. Rev. Nucl. Part. Sci. 50, 525(2000).
2) See “Accessing the Gluon Polarization through π ± ALL
at PHENIX”, A. Morreale, C. Aidala, and K. Boyle inthis volume.
3) I. Ravinovichet al., Nucl. Phys. A 774, 903 (2006).
4) Y. Akiba et al., Nucl. Instrum. Meth. A 433 143 (1999).

- 92 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Spin dependent structure functions of finite nuclei†
W. Bentz,∗1 I. C. Cloet,∗2 and A. W. Thomas∗3[NUCLEAR STRUCTURE FUNCTIONS, Spin dependence, Effective Quark Theories]
The most famous effect which shows how the nucleon
structure responds to the environment inside a nucleus
is the EMC effect, which is expressed by the following
ratio:(1)

where F2A is the spin independent nuclear structure
function, and F2p , F2n are the spin independent freenucleon structure functions. In this paper, we will use
a mean field model for the nucleus, which incorporates
the quark substructure of the nucleons, to calculate
the ratio (1), and also to make predictions for the corresponding polarized EMC ratio:
JH
RAs
=

JH
g1A
.
PpJH g1p + PnJH g1n

∗1
∗2
∗3

7
1.1

JH
Here g1A
is the spin dependent structure function of a
nucleus with spin J and helicity H (along the directionof the incoming electron momentum), g1p and g1n are
the spin dependent free nucleon structure functions,and the polarization factors are defined as the expectation values of the proton and neutron spin operatorsin the polarized nucleus: PαJH =< J, H|2Szα |J, H >(α = p, n). The ratios (1) and (2) are defined so thatthey reduce to unity in the absence of medium (including Fermi motion) effects. One important difference
between the ratios (1) and (2) is that, for the latter
case, in order to pin down the medium effects we need
the polarization factors, which incorporate the nuclear
structure effects and are not known a priori. Fromthe experimental standpoint, if g1A can be measured,
one should use the most realistic polarization factors
to form the ratio (2). From the theoretical standpoint,
one should calculate both the numerator and denominator of (2) in the same framework.
In our calculations, we describe the single nucleon as
a bound state of a quark and a scalar or axial vector diquark, following the Faddeev approach to the NambuJona-Lasinio (NJL) model. This allows us to computethe single nucleon structure functions1) . The nucleus
is treated in the mean field approximation where thesources of the mean scalar and vector fields are thequarks inside the nucleons, similar in spirit to the successful quark-meson coupling model. This allows us tocompute the momentum distributions of the nucleons
†

1.2

(2)

Condensed from an article by I.C. Cloet, W. Bentz, andA.W. Thomas, Phys. Lett. B 642 (2006) 210.
Department of Physics, Tokai University, Kanagawa, Japan
Department of Physics, University of Adelaide, Australia
Jefferson Laboratories, Newport News, VA, U.S.A.

- 93 -EMC Ratios

F2A,
ZF2p + N F2n

Li

1
0.9
0.8

Experiment: 9 Be
Unpolarized EMC effect

0.7
0.6
0

(3/2 1)

Polarized EMC effect:

RAs

Polarized EMC effect:

RAs

0.2

0.4

x

3/2 3/2

0.6

Q2 = 5 GeV2
0.8

1

Fig. 1. Polarized (solid and dotted lines) and unpolarized(dashed line) EMC ratios for 7 Li.

1.2

27
1.1

EMC Ratios

RA =in the nucleus. The nuclear structure function is thenobtained by the convolution formalism2) .
In Figs. 1 and 2 we show the EMC ratios for the
proton-hole nuclei 7 Li and 27 Al. The line which tends
to have a dip for large Bjorken x refers to the ratio(2) for H = 3/2, while the other spin dependent ratio
refers to the leading multipole (K = 1) combination2)of H = 3/2 and H = 1/2. Our calculations predictthat the polarized EMC effect is stronger than the unpolarized one, with the possible exception of 7 Li atlarge x. This is related to a quenching of the spin sum
in the nucleus: Our calculated spin sums for a free nucleon, 7 Li, 27 Al and infinite nuclear matter are 0.67,
0.62, 0.59 and 0.49.

Al

1
0.9
0.8

Experiment: 27 Al
Unpolarized EMC effect

0.7
0.6
0

(5/2 1)

Polarized EMC effect:

RAs

Polarized EMC effect:

RAs

0.2

0.4

x

5/2 5/2

0.6

Q2 = 5 GeV2
0.8

1

Fig. 2. Same as Fig. 1 for 27 Al.

References
1) I.C. Cloet, W. Bentz and A.W. Thomas, Phys. Lett. B
621 (2005) 246.
2) R.L. Jaffe and A. Manohar, Nucl. Phys. B 321 (1989)
343.

31

RIKEN Accel. Prog. Rep. 40 (2007)

Color superconductivity and neutron star structure†
W. Bentz,∗1 S. Lawley, ∗2 and A. W. Thomas,∗3[MATTER AT HIGH DENSITY, Compact stars]
Effective quark theories enable us to incorporate
the quark structure of hadrons into the descriptionof nuclear matter (NM) at normal densities, and at
the same time to investigate the structure of compact
stars, where a phase transition to quark matter (QM)
may take place at high baryon densities. In this paper,
we report on our recent calculations on the equationof state (EOS) of 2-flavor matter and compact star
structure in the Nambu-Jona-Lasinio (NJL) model.
The single nucleon is constructed as a quark-diquark
bound state, where both the scalar and the axial vector diquark channels are included. We also include
the pion cloud effect on the nucleon mass, which typically leads to mass shifts (Σπ ) of 200 - 400 MeV. In
this work we will consider the following cases: (A):Σπ = 0 (no pion cloud); (B): Σπ = −200 MeV; (C):Σπ = −300 MeV; (D): Σπ = −400 MeV. For eachcase, the strengths of the scalar and axial vector diquark interactions are adjusted so as to reproduce theexperimental nucleon and delta masses.
The EOS of charge neutral NM in beta-equilibriumis then described in the mean field approximation,
where the mean scalar-isoscalar, vector-isoscalar andvector-isovector fields couple to the quarks inside thenucleons, rather than to point nucleons. The mostimportant effect of the quark substructure at normal
densities is summarized in the scalar polarizability of
the nucleon, which is very important for saturation1) .
By using the same effective quark theory, we also
calculate the EOS of QM, including the possibility ofquark pairing (color superconductivity) in the scalardiquark channel. The Gibbs conditions (equality ofpressure and chemical potentials for baryon number
and isospin) are then used to investigate the transition from NM to QM2) . The key point in our present
work is to equate the pairing strength for the color
superconducting pairs in QM with the scalar diquarkinteractions inside the nucleons in NM. From our above
discussion, it is clear that the scalar pairing strength
will decrease as we go (A) → (B) → (C) → (D). Since
for case (A) (no pion cloud) the scalar diquark pairing
is so strong that QM would become the ground stateeven at normal densities, we consider this case only forthe pure NM EOS.
In Fig.1 we show the pressure as a function of thebaryon density for the 4 cases, and in Fig.2 we show
†
∗1
∗2
∗3

Condensed from an article by S. Lawley, W. Bentz, andA.W. Thomas, J. Phys. G 32, 667 (2006).
Department of Physics, Tokai University, Japan
Department of Physics, University of Adelaide, Australia
Jefferson Lab, Newport News, VA, U.S.A.

- 94 -

the corresponding star masses vs. central baryon density. We see that decreasing the pairing strength has
2 effects: The phase transition moves to higher densities, and the EOS on the NM side becomes softer. The
phase transition to QM leads to plateaus in the starmasses, which correspond to hybrid stars with a small
region of QM in the center. For the cases (B) and (C)we also get “twin” solutions at high central densities,
which correspond to quark stars with radii of about 8km.

Fig. 1. Pressure vs. baryon density for the cases (A) (solidline), (B) (dashed line), (C) (dash-dotted line) and (D)(dotted line) discussed in the text.

Fig. 2. Star masses vs. central density for the same cases
as in Fig.1.

References
1) W. Bentz and A.W. Thomas, Nucl. Phys. A 696, 138(2001).
2) S. Lawley, W. Bentz and A.W. Thomas, Phys. Lett. B
632, 495 (2006).

35

RIKEN Accel. Prog. Rep. 40 (2007)

Isospin breaking on baryons with Nf =2 domain wall fermions†T. Doi,∗1 T. Blum,∗1,∗2 M. Hayakawa,∗3 T. Izubuchi,∗1,∗4 and N. Yamada∗5,∗6 (for the RBC collaboration)
In this work, we study the isospin breaking effect on
baryons, such as the proton-neutron (p-n) mass difference, which is one of the most fundamental quantities
in nuclear physics. In fact, this quantity governs the
β-decay of the neutron, i.e., the lifetime of the neutron, and correspondingly, the nucleosynthesis and thehistory of the universe. In the experiment, the isospin
breaking effect is observed as splitting between isomultiplets in octet/decuplet members, and also as charge
symmetry breaking in the N -N interaction.
The study of isospin breaking corresponds to thedetermination of both the u, d quark mass difference
in QCD and the electromagnetic (EM) effect in QED.
The former is interesting from the viewpoint of thestrong CP problem, i.e., we can examine whether massless quark(s) really exist or not. The latter also becomes an urgent task in the search for new physics
beyond the standard model. For example, in themuon g−2 calculation, hadronic light-by-light scattering causes large uncertainty, and the QCD + QED simulation has been proposed to resolve this problem1) .
We study the EM effect on the mass difference between baryon isomultiplets as mp − mn , mΣ+ − mΣ0 ,mΣ− − mΣ0 , mΣ+ − mΣ− , mΣ+ + mΣ− − 2mΣ0 , mΞ− −mΞ0 using the QCD + QED simulation. Our study forthe meson sector is given in Ref.2) In the QCD sector,
we use the Nf =2 unquenched QCD configurations3)
generated by the domain-wall fermion and the DBW2
gauge action with the parameters of V = 163 × 32,
Ls = 12, M5 = 1.8, β = 0.8 and msea = 0.02, 0.03, 0.04.
We pick up about 200 configurations at each sea quark
mass. In the QED sector, we employ a noncompact
formulation at the quenched level4) . The advantageof this formulation is that there is no autocorrelation between the configuration even for an arbitrarysmall coupling and that there is no need for the renormalization of QED coupling αem ≡ e2 /4π, because
the photon dynamics becomes a free theory. In order to study the QED charge dependence, we use not
only the physical QED charge but also the charges of
e = (0), 0.6, 0.85, 1.0. The baryon mass is measured
using the two-point correlator. In the Q = 0, S = −1
channel, the variational method is used to extract Σ0
as the first excited state in this channel.
Because the isospin breaking has a rather small effecton the mass (δm(breaking) ∼ 1MeV vs m ∼ 1GeV), it isnecessary to explore an effective way of improving S/N.
For this purpose, we analyze the ratio between the correlators of the isomultiplets. Considering the p-n for
instance, we can express Rp/n (t) ≡ Πpp (t)/Πnn (t) =1 + 2(λp − λn )/(λp + λn ) − (mp − mn ) · t + O(e4 ), whereλp (λn ) is the proton (neutron) overlap constant between the state and the operator. The plot of Rp/n (t)is given on the left-hand side of Fig. 1. Unfortunately,
S/N is not so good as to allow us to make a conclusive
statement.
In order to overcome the above difficulty, we examine the origin of the fluctuation in the lattice result. In
particular, we focus on the O(e) contamination in thecorrelator, which is nothing but statistical noise because the EM effect on observables appears only fromO(e2 ). In order to eliminate O(e) contamination, we
evaluate the correlator for not only e = +|e| but alsoe = −|e|, and take the average between them. This
corresponds to the use of the QED configuration of{AQED} → {AQED, −AQED} with binning. The resultµµµis shown on the right-hand side of Fig. 1. We observe a
clear negative linear slope for each QED charge, whichindicates mp > mn from the EM effect. It is foundthat O(e) contamination is the dominant source of thefluctuation, and that e = ±|e| average is the essential
procedure. We also observe that this procedure is effective for studying isospin breaking in the meson sector
as well. As a result of the marked success of S/N improvement, we can determine the EM effect precisely.
The determination of the EM effect, as well as the u, dquark mass difference effect, is in progress.
References
1) M. Hayakawa, T. Blum, T. Izubuchi and N. Yamada,
PoS LAT2005, 353 (2006), hep-lat/0509016.
2) N. Yamada, T. Blum, M. Hayakawa and T. Izubuchi(RBC), PoS LAT2005, 092 (2006), hep-lat/0509024.
3) Y. Aoki et al., (RBC), Phys. Rev. D72, 114505 (2005).
4) A. Duncan, E. Eichten and H. Thacker, Phys. Rev. Lett.
76, 3894 (1996); ibid. Phys. Lett. B409, 387 (1997).

1.04

∗1
∗2
∗3
∗4
∗5
∗6

Condensed from the article in PoS LAT2006, 174 (2007)
RIKEN BNL Research Center, Brookhaven National Lab.
Physics Department, University of Connecticut
Department of Physics, Nagoya University
Institute for Theoretical Physics, Kanazawa University
High Energy Accelerator Research Organization (KEK)
The Graduate University for Advanced Studies (Sokendai)

1

0.98
0.96

0.92
0.9
0

Rp/n(t)

1.02

1

0.94

†

1.04

Rp/n(t)

1.02

0.98
e=0
e=e(phy)e=0.6
e=0.85
e=1.0
5

0.96
0.94
0.92
10

time: t

15

0.9
0

|e|=0
|e|=e(phy)|e|=0.6|e|=0.85|e|=1.0
5

10

time: t15

Fig. 1. Ratio of correlators of proton and neutron Rp/n at
msea =0.03 against t for each QED charge e. The left
(right) figure is obtained with e = |e| (e = ±|e|).

- 95 1

RIKEN Accel. Prog. Rep. 40 (2007)

Initial Singularity in the Little Bang
K. Fukushima, F. Gelis∗1 and L. McLerran∗2[Color Glass Condensate, heavy-ion collision, instability, quantum fluctuation]
The Color Glass Condensate (CGC) provides a description of the wave function of a hadron at very smallvalues of x. The CGC is a high-density state of gluons that is controlled by a weak coupling because of thehigh gluon density. Its properties are computable fromfirst principles in Quantum Chromodynamics (QCD),
at least in the limit of extremely high density.
The CGC has also been applied to heavy-ion collisions to generate the initial conditions for the evolution of matter in the forward light cone1) . There
are boost-invariant solutions of the equations of motion supposedly appropriate for the high-energy limit.
It has recently been discovered2) , however, that the
boost-invariant solution of the equations of motion are
unstable with respect to rapidity-dependent perturbations. This instability has, in fact, close connections
with the Weibel instabilities encountered in the physics
of anisotropic plasmas, and it is speculated that suchan instability may help the system created after heavyion collisions reach a state of local equilibrium.
The evolution from the initial collision to the final
state is shown in Fig. 1. Because of the similarities
between the expansion of the universe in cosmology
and the expansion of matter in heavy-ion collisions,
we call the latter the “little bang”. The initial singularity in cosmology is replaced by the singularity in theclassical equations of motion associated with the collision. It is in the forward light cone that instabilities
develop, and there could be a Kolmogorov spectrum of
density fluctuations generated. This spectrum is similar to the spectrum of density fluctuations generated
during inflationary cosmology. After inflation, the system reheats and thermalizes, forming an electroweak
plasma. In the little bang, thermalization might also
be achieved after the expansion in the forward lightcone.
In this work, we discuss a generic approximation
scheme for calculating the quantum expectation valueof an observable that depends on field configurations atlate times. In the WKB approximation, we obtained aformula giving this expectation value from the classicalequations of motion, with an initial condition that includes fluctuations. The spectrum of these initial fluctuations is described by the Wigner transform of the
wave function, the latter being obtained as a groundstate solution of the Schrödinger equation.
An application of particular interest to heavy-ion
collisions is to calculate the Wigner function of these†∗1∗2z = -ttz=t
Quark Gluon Plasma

GlasmaPerfect Fluid
Hadronization
τ~ 1 - 10 fm/c

Topological Excitations
Density Fluctuations, Thermalization
τ~ 0.1 - 1 fm/c

Initial Singularityz

Event Horizon
Quantum Fluctuations
τ~ 0 - 0.1 fm/c

Fig. 1. A light-cone diagram illustrating the evolution ofmatter produced in heavy-ion collisions.

fluctuations immediately after the initial impact of thetwo nuclei in the weak-coupling regime. These initialquantum fluctuations provide the seeds that trigger the
instability of the rapidity-dependent modes. The precise determination of initial fluctuations or seeds is of
crucial importance for the estimate of the growth rateof the unstable modes.
By identifying the physically relevant gauge fluctuations and the singularity in the Hamiltonian density,
we derived the discontinuity between the wave functions in the backward and forward light cones. It turns
out that the initial singularity results only in a shift in
the transverse gauge fields by the classical backgroundfield.
This wave function and the resultant Wigner function describe the spectrum of initial fluctuations.
There are two noteworthy features in our results.
Firstly, both the transverse gauge fields and theircanonical momenta fluctuate with 2-point correlations
that are inversely related to one another. This meansthat if the boost invariance is significantly violated bymomentum fluctuations, then gauge-field fluctuations
are suppressed, and vice versa. Thus, the prescription,in which only momentum fluctuations are taken into
account2) , needs to be extended to include gauge-field
fluctuations also.
Secondly, the off-diagonal correlation between different transverse components does not vanish. Again,
this feature was not apparent in the preceding study2) .
References
1) T. Lappi and L. McLerran: Nucl. Phys. A772, 200(2006).
2) P. Romatschke and R. Venugopalan: Phys. Rev. Lett.
96, 062302 (2006).

Condensed from the article in hep-ph/0610416.
Service de Physique Théorique, Saclay, France
Department of Physics, Brookhaven National Lab., USA- 96 -

1

RIKEN Accel. Prog. Rep. 40 (2007)
RIKEN Accel. Prog. Rep. 00 (0)Heavy Quarkonium States in a Gluon PlasmaÁgnes Mócsy and Péter Petreczky∗1”Melting” of heavy quarkonium has been long beenthought of as an unambiguous signature of a transition to deconfined matter in finite temperature QCD1) .
This in turn would translate into the suppression of theJ/ψ peak in the dilepton spectrum, providing an experimentally detectable signal for deconfinement. Thissignature has been looked for in relativistic heavy ion
collisions at SPS-CERN and RHIC-BNL2) .
Recently available quarkonia studies performed inlattice QCD suggest however that the J/ψ not only
survives to temperatures much higher than the deconfinement transition temperature, but also that its
properties (mass, amplitude) are unchanged up to atleast 1.5Tc3) .
We investigated the source of this unexpected discrepancy by determining the spectral functions andcurrent-current correlators in the different quarkonia
channels - these being the quantities obtained on thelattice. We assumed that the interaction between
the heavy quark and antiquark is described by atemperature-dependent potential - as customarily usedin the potential model studies also yielding the original
predictions.
In our initial studies4,5) we design a spectral functionthat includes bound states, as well as the perturbative
continuum above some threshold. The temperaturedependence of the quarkonium properties is obtainedby solving the two-body Schrodinger equation witha temperature-dependent potential. While a description in terms of the Schrodinger equation is in order,
since the heavy quark mass allows for a nonrelativistic
treatment of the quarkonium, the use of a potential
description of the interaction between the quark andthe antiquark is highly questionable at finite temperature. The validity of potential models is restricted
to the case when the interaction between the heavy
quark and antiquark is instantaneous, i.e. the gluonexchange between the quarks is much faster than theinternal time-scale of the bound state. At zero temperature this condition is given by the hierarchy of energy scales which also allows for the derivation of theCornell-potential directly from QCD6) . Whether suchcondition is fulfilled at finite temperature is not at all
clear, and requires further QCD-based studies, that are
not yet available. Due to a lack of knowledge different
assumed potentials are used in the literature, such as ascreened Cornell potential, the free- and the internalenergy of a heavy quark-antiquark pair as determinedon the lattice, and also a combination of these energies. In view of these uncertainties our results are not∗1

surprising: we found that the correlators and spectral
functions in the vector and pseudoscalar quarkonium
channels as determined in our calculations show a behavior not seen in the lattice QCD results.
In a refined analysis we further investigated the behavior of the quarkonium states at finite temperature by replacing the two-body Schrodinger calculation
with a full Green’s function analysis. This is necessary
in order to take into account multi-particle effects andhave a consistent description of bound- and scattering
states, as well as threshold effects. The spectral functions obtained from the nonrelativistic Green’s function calculation together with the nonrelativistic perturbative continuum at high energies, and the correlators calculated from these, again, show disagreementwith the lattice data. We identify as the source fordisagreement the strong modification of the groundstate properties. This is an intrinsic outcome of all
the screened potentials. If however, the ground state
would stay unchanged, as suggested by the lattice spectral function data, then the behavior of lattice correlators can be recovered from the model calculations.
In this case the melting of the higher excited states
is compensated for by the decrease of the continuum
threshold with increasing temperature. This result
is consistent with our study based on a simple toymodel10) .
References
1) T. Matsui and H. Satz, Phys. Lett. B 178, 416 (1986).
2) P. Cortese et al. [NA50 Collaboration], J. Phys. G 31(2005) S809; R. Arnaldi et al. [NA60 Collaboration],
Eur. Phys. J. C 43 (2005) 167; M. Calderon de la Barca
Sanchez, arXiv:nucl-ex/0606009; R. G. de Cassagnac[the PHENIX Collaboration], arXiv:nucl-ex/0608041.
3) Most recent results: A. Jakovac, P. Petreczky,
K. Petrov and A. Velytsky, Phys. Rev. D 75, 014506(2007) [arXiv:hep-lat/0611017].
4) Á.Mócsy and P.Petreczky, Eur. Phys. J. C 43, 77(2005) [arXiv:hep-ph/0411262].
5) Á. Mócsy and P. Petreczky, Phys. Rev. D 73, 074007(2006) [arXiv:hep-ph/0512156].
6) N. Brambilla et al., arXiv:hep-ph/0412158, and references therein.
7) E. V. Shuryak and I. Zahed, Phys. Rev. C 70, 021901(2004); Phys. Rev. D 70, 054507 (2004); C. Y. Wong,
Phys. Rev. C 72, 034906 (2005); W.M.Alberico et al,
Phys. Rev. D 72, 114011 (2005); M.Mannarelli and
R.Rapp, arXiv:hep-ph/0509310.
8) Á. Mócsy and P. Petreczky, arXiv:hep-ph/0606053.
9) Á. Mócsy, P. Petreczky and J. Casalderrey-Solana,
arXiv:hep-ph/0609205.
10) Á. Mócsy, arXiv:hep-ph/0606124.

Physics Department and RIKEN-BNL Research Center,
Brookhaven National Laboratory, Upton, NY, USA- 97 -

RIKEN Accel. Prog. Rep. 40 (2007)

Nucleon structure in lattice QCD with dynamical domain-wall
fermions
S. Ohta,∗1∗2∗3[Hadron structure, Quantum Chromodynamics]
I summarize lattice quantum chromodynamics numerical calculations of nucleon structure done in thepast year using parallel supercomputers at RIKENBNL Research Center. The calculations are parts of
the RIKEN-BNL-Columbia (RBC) Collaboration and
RBC-UKQCD Intercollaboration.
The RBC collaboration have been calculating various form factors and moments of structure functionsof nucleon in numerical lattice QCD with domain-wall
fermion (DWF) quarks. In contrast to more conventional lattice fermions such as Wilson or staggered,the DWF preserves the important chiral and flavor
symmetries. With quenched calculations we demonstrated the importance of these symmetries near thechiral limit1) , in reproducing the mass of nucleon andits parity partner2) , and in calculating meson decay
constants3) and nucleon form factors4) and structure
functions5) .
Here we report two sets of calculations6) : one with
RBC ensembles with two degenerate dynamical DWF
flavors corresponding to up and down, and anotherwith RBC-UKQCD ensembles with one strange andtwo degenerate (up and down) dynamical DWF flavors. The former was completed using the QCDSP
computer and has about 200 gauge configurations at
each of the three up/down mass values7) . The latteris still on-going on the QCDOC computer and has 2030 gauge configurations at each of the three up/downmass values while the strange mass is fixed at about
the physical value8,9) .
In Figure 1 we present the ratio of the isovector axial
and vector charges, gA /gV , for both sets of calculations
plotted against the calculated pion mass squared. Thisratio is naturally renormailized when calculated with
DWF, and so is directly comparable with experiment.
The results show mild dependence on the pion masssquared which is linear in up/down quark mass near
the chiral limit. If fitted with a linear behavior, we obtain a value of gA /gV consistent with the experiment.
Also in Figure 1 we present the ratio of the first
moments of two structure functions, hxiu−d /hxi∆u−∆dor the ratio of the momentum and helicity fractionsof quarks, again for both sets of calculations plottedagainst the calculated pion mass squared. Again theratio is naturally renormailized when calculated with
DWF, and so is directly comparable with experiment.
∗1
∗2
∗3

Institute of Particle and Nuclear Studies, KEK
RIKEN-BNL Research Center, BNL, USA
Department of Physics, SOKENDAI

- 98-

1.6
1.5
1.4
1.3
1.2
1.1
1
-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0

0.1

0.2

0.3

0.4

0.5

0.6

1
0.95
0.9
0.85
0.8
0.75
0.7
0.65
0.6
0.55
0.5
-0.1

Fig. 1. Above: ratio of the isovector axial and vector
charges of nucleon, gA /gV . Below: ratio of the momentum and helicity fractions of quarks within nucleon.
Both plotted against the calculated pion mass squaredin (GeV)2 . The RBC 2-flavor results are denoted by red+ symbols while the RBC-UKQCD (2+1)-flavor results
are by blue ×. The experiments are in purple 2.

The results show mild dependence on the pion masssquared, and is in broad agreement with experiments.
I thank the members of the RBC, UKQCD and QCDOC collaborations.
References
1) Blum, T. et al. Phys. Rev. D69, 074502 (2004).
2) Sasaki, S., Blum, T., and Ohta, S. Phys. Rev. D65,
074503 (2002).
3) Blum, T. et al. Phys. Rev. D68, 114506 (2003).
4) Sasaki, S., Orginos, K., Ohta, S., and Blum, T. Phys.
Rev. D68, 054509 (2003).
5) Orginos, K., Blum, T., and Ohta, S. Phys. Rev. D73,
094503 (2006).
6) Lin, H.-W. and Ohta, S. PoS LAT2006, 118 (to be
published).
7) Aoki, Y. et al. Phys. Rev. D72, 114505 (2005).
8) Lin, M. PoS LAT2006, 185 (to be published).
9) Tweedie, R. PoS LAT2006, 096 (to be published).

1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4000(2007)(0)

Finite temperature transition in three flavor QCD
P. Petreczky,∗1
Lattice QCD has established the existence of a transition from hadron gas to a new state of strongly interacting matter where quarks and gluons are no longer
confined inside hadrons and which is usually called the
Quark Gluon Plasma1,2) . The nature of this transition
depends on the quark content and quark masses. For
infinite or very large quark masses the transition is a
1st order deconfining transition. In the opposite caseof zero quark masses one may have a 2nd order chiral phase transition for 2 flavors or a 1st order chiralphase transition for 3 flavors. For arbitrary masses thetransition is just a rapid crossover, meaning that thermodynamic quantities change very rapidly in a narrow temperature interval. The boundary of the 1storder transition region of 3-flavor QCD as a functionof mass has been studied using improved (p4)3) andstandard staggered actions4,6) . There is a significant
discrepancy regarding the value of the quark masses,
or equivalently the value of the pseudo-scalar meson
masses where the transition changes from crossover to
1st order. With an improved action it was found thatthe 1st order transition ends for pseudo-scalar meson
masses of about 70 MeV, while with the standard action it ends for pseudo-scalar meson masses of about
190 MeV4,5) or larger6) .
We investigate the finite temperature transition in
3 flavor QCD using the improved staggered p4 action and the standard R algorithm. Numerical calculations have been done on lattices with temporalextent Nτ = 4 and 6 and at several values of thequark mass. We use the Polyakov susceptibility andthe disconnected part of the chiral susceptibility to locate the pseudo-critical gauge coupling βc . To set thelattice spacing we use the Sommer scale defined fromthe static potential as r2 dV /dr|r = r0 = 1.65. Thus
we determined the transition temperature in units of
the Sommer scale, i.e. r0 Tc . The quark masses used inour study correspond for pseudo-scalar meson masses
mps r0 = 0.4−1.45 for Nτ = 4 lattices and mps r0 = 0.8
and 1.25 for Nτ = 6 lattices. We find no evidence fora 1st order phase transition for these quark masses.
Since we have the value of the transition temperature
for two different lattice spacings and quark masses weattempted a combined extrapolation to the continuum
and chiral limit. We expect that the finite lattice spacing errors should scale as O(a2 ) and thus the latticeerrors in Tc r0 should scale as 1/Nτ2 . If there is a critical point in the (T, m)-plane, then universality dictatesthat Tc (m) − Tc (me ) ∼ (m − me )1/(δβ) with β and δ
being critical exponents. In the case of three degen∗1

erate flavors the line of the 1st order transition in the
T −m plane ends in a critical end-point Tc (me ) belonging to the Z(2) universality class. For this universality
class we have δβ = 1.5654. Therefore we attempteda combined continuum and chiral extrapolation using
the following extrapolation ansatz
r0 Tc (mps , Nτ ) = r0 Tc |cont (meps ) +¡¢1/(δβ)Ar02 m2ps − m2ps,c+ B/Nτ2 .

(1)

The value of the quark mass where the transitionchanges from 1st order to crossover, i.e. the mass corresponding to the end-point, has been estimated using Nτ = 4 lattices to be me = 0.0007(4)3) . Thistranslates into the value of the pseudo-scalar masser0 meps = 0.16+3−5 . The cutoff dependence of mps is
expected to be smaller than the statistical error. It
turns out that this large uncertainty in the value ofmeps produces an uncertainty in the extrapolated valueof Tc (m2ps ) which is much smaller than the statisticalerrors. The extrapolation according to Eq. (1) yieldser0 Tc (mps
) = 0.429(8) with χ2 /dof = 0.7.
The value of Tc could be compared with the corresponding 2 + 1 flavor value Tc r0 = 0.444(6)[+12][−6]in the chiral limit7) . Thus the flavor dependence of
Tc is about or smaller than 5%. One should also notethat the difference between the transition temperature
calculated on Nτ = 4 and Nτ = 6 lattices is very
similar to that found in 2+1 flavor case7) . The results presented in this report are based on work donewith RBC-Bielefeld Collaboration. The majority of
the calculations reported here were carried out using
the QCDOC supercomputers of the RIKEN-BNL Research Center and the U.S. DOE. In addition some of
the work was done using the APE1000 supercomputerat Bielefeld University.
References

Physics Department and RIKEN-BNL Research Center,
Brookhaven National Laboratory, Upton, NY, USA- 99 -

1) F. Karsch, Lect. Notes Phys. 583, 209 (2002)
2) E. Laermann and O. Philipsen, Ann. Rev. Nucl. Part.
Sci. 53, 163 (2003)
3) F. Karsch, et al., Nucl. Phys. Proc. Suppl. 129, 614(2004)
4) C. Schmidt, C. R. Allton, S. Ejiri, S. J. Hands,
O. Kaczmarek, F. Karsch and E. Laermann, Nucl.
Phys. Proc. Suppl. 119, 517 (2003) [arXiv:heplat/0209009]. F. Karsch, E. Laermann and C. Schmidt,
Phys. Lett. B 520, 41 (2001)
5) P. de Forcrand and O. Philipsen, Nucl. Phys.
Proc. Suppl. 129, 521 (2004) P. de Forcrand andO. Philipsen, Nucl. Phys. Proc. Suppl. 129, 521 (2004)
6) N.H. Christ and X. Liao, Nucl. Phys. B (Proc. Suppl.)
119, 514 (2003)
7) M. Cheng et al., Phys. Rev. D 74, 054507 (2006)

1

RIKEN Accel. Prog. Rep. 40 (2007)

Automatic O(a) improvement for twisted-mass QCD†
S. Aoki∗1,∗2 and O. Bär∗3[Lattice QCD, twisted-mass, improvement]
It becomes more and more apparent that twisted
mass Lattice QCD (tmLQCD)1,2) is a promising
formulation to approach the chiral limit of QCD.
A twisted mass protects the Wilson-Dirac operator
against small eigenvalues and therefore solves the
problem of exceptional configurations,thus making numerical simulations with small quark masses feasible.This numerical advantage of tmLQCD is supplemented by the property of automatic O(a) improvement3) . The so-called “maximal twist” condition, required for the proof of automatic O(a) improvement3) ,however, causes some confusions4) . Therefore, in thisreport, we reconsider the proof of the automatic O(a)improvement of tmLQCD5) , by clarifying an exact condition for the maximal twist.
We give a main idea of the proof. The lattice theory can be described by an effective continuum theory, whose effective action is restricted by locality
and symmetries of the underlying lattice theory. Taking into account the symmetries such as U(1)⊗U(1)vector symmetry, the extended parity symmetry andthe standard charge conjugation symmetry, one finds
Seff = S0 + aS1 + a2 S2 + · · · for the quark part, where
Z
i
h
3
(1)
S0 =
d4 x ψ̄(x) γµ Dµ + MR eiθγ5 τ ψ(x),Z(2)
S1 = C1 d4 x ψ̄(x)σµν Fµν (x)ψ(x).
In addition to the effective action we have to specify
the direction of the chiral condensate, since chiral symmetry is spontaneously broken. From the fact that thedirection of the chiral condensate is completely controlled by the direction of the symmetry breaking external field in the continuum theory, we can takev(MR ) h −iθγ5 τ 3 ijihψ̄αi ψβj iS0 =
,
(3)
e
8
βα
where limMR →0 limV →∞ v(MR ) 6= 0. Here the vacuum
expectation value (VEV) is defined with respect to thecontinuum action S0 .
We now want to argue that the choice θ = π/2 (or−π/2) corresponds to “maximal twist”. In terms of themass parameters this is equivalent to µR = MR andmR = 0, where mR = MR cos θ and µR = MR sin θ. In
†
∗1
∗2
∗3

Condensed from the article in Phys. Rev. D74, 034511(2006)
Graduate School of Pure and Applied Sciences, Universityof Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
Riken BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973, USA
Institute of Physics, Humboldt University Berlin, Newtonstrasse 15, 12489 Berlin, Germany

this case the action and the VEVs become
Z


S0 =
d4 x ψ̄(x) γµ Dµ + iMR γ5 τ 3 ψ(x),(4)

hψ̄ψiS0 = 0, hψ̄iγ5 τ 3 ψiS0 = v(MR ) . It is easy tocheck that S0 , the continuum part of the effective ac1,2
1,2
tion is invariant under ψ → eiwγ5 τ ψ, ψ̄ → ψ̄eiwγ5 τ ,and therefore also under the Z2 subgroup T1 of thiscontinuous transformation, defined by T1 ψ = iγ5 τ 1 ψ,
T1 ψ̄ = ψ̄iγ5 τ 1 . Since T12 = 1 in the space offermion number conserving operators, which containequal numbers of ψ and ψ̄, the eigenvalues of T1 are
1 (T1 -even) or −1 (T1 -odd). The crucial observationis that the VEVs hψ̄ψi and hψ̄iγ5 τ 3 ψi are also invariant under this transformation. The T1 symmetry is not spontaneously broken, hence it is an exact
symmetry ofR the continuum theory. The O(a) term
aS1 = aC1 d4 x ψ̄(x)σµν Fµν (x)ψ(x), on the other
hand, is odd under T1 . Therefore, non-vanishing physical observables, which must be even under T1 , can nothave an O(a) contribution, since the O(a) term is odd
under T1 and therefore must vanish identically. Thisis automatic O(a) improvement at “maximal twist”.
Note that non-invariant, i.e. T1 -odd quantities, which
vanish in the continuum limit, can have O(a) contributions.
The above argument gives just the main idea of ourproof for automatic O(a) improvement, and we havealready given a detailed proof in Ref.5) . However, oneof the most important points of our analysis is thatthe condition for automatic O(a) improvement is theinvariance of theory under T1 transformation, or moregenerally its continuous version, which corresponds toa part of the exact vector symmetry in continuum QCD
at “maximal twist”. One might even say that the T1
invariance is more fundamental for automatic O(a) improvement than the notion of “maximal twist”, which
is one of the consequences of T1 invariance.
This work is supported in part by the Grants-inAid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology. (Nos.
13135204, 15204015, 15540251, 16028201), O. B. is
supported in part by the University of Tsukuba Research Project.
References
1) R. Frezzotti, S. Sint and P. Weisz, JHEP 07 (2001) 048.
2) R. Frezzotti, P. A. Grassi, S. Sint and P. Weisz, JHEP
08 (2001) 058.
3) R. Frezzotti and G. C. Rossi, JHEP 10 (2004) 070.
4) S. Aoki and O. Bär, Phys. Rev. D70 (2004) 116011.
5) S. Aoki and O. Bär, Phys. Rev. D74 (2006) 034511.

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1

RIKEN Accel. Prog. Rep. 40 (2007)

Proton decay matrix elements with Nf = 0 and 2 domain-wall QCD†
Y. Aoki, C. Dawson, J. Noaki,∗1 A. Soni,∗2[Lattice QCD, grand unified theories]

†
∗1
∗2

Condensed from the article1) .
High Energy Accelerator Research Organization (KEK)Brookhaven National Laboratory

a=0.1 fm
a=0.15 fm

30.6−(α−β) r0

Proton decay, once observed, is a smoking gun evidence of the physics beyond the standard model. It
naturally happens under (SUSY) GUT. On-going deep
mine experiments, though yet to observe an event,are pushing up the lower bound of of the proton lifetime, excluding GUT models which allow protons decay more frequently. Hadronic matrix elements of the
proton decay are essential ingredients in estimating
lifetime of proton. Lattice QCD provides the mostreliable estimate for such low energy hadronic quantities.
There are two ways to calculate the matrix elementson the lattice: the direct calculation using three point
functions and the indirect calculation which uses chiral perturbation theory with two low energy parameters (α and β) to be calculated on the lattice. The
indirect calculation is nothing but an approximation at
the lowest order in the final state pion energy, which
is order of the nucleon mass in CM frame, thus quite
large. As such, it is expected to have limited applicability on the matrix elements in the physical kinematics, though historically this approach dominates overthe direct calculation, which requires typically a factorof 10 more computation than the indirect calculation.
Until quite recent, even for the easier indirect calculation, lattice results of the low energy parametersfrom different groups have not converged to the common values. The failure could be ascribed to latticeintrinsic systematic errors.
This study aims to remove many of the systematic
errors, and it has been quite successful. We have developed a method of non-perturbative renormalization(NPR) of the proton-decay operators by the RomeSouthampton RI/MOM scheme. Using the NPR, ambiguity of the lattice perturbation has been completely
removed. The usage of domain-wall fermion reduced
the discretization error which is demonstrated in Fig. 1
for the low energy parameter. Fig. 2 summarizes our
result of the relevant form factors for each decay process in quenched approximation. Both results with thedirect and indirect calculations are shown. Any matrix element of nucleon decaying to pseudoscalar meson via four-fermion operator can be calculated fromthose shown in the figure. It is noted that the indirect
method poorly approximates the values by the direct
method. Especially for the final-pion matrix elements
the indirect method overestimates by an approximate

0.5

0.4
0

0.1

0.2

r0 mq

0.3

0.4

0.5

Fig. 1. The low energy parameter of proton decay as afunction of the quark mass in quenched approximation
with DWF. Both axes have been normalized by r0 (r0 ≃0.5 fm) to be dimension-less. Results from two different
lattice spacings are consistent.
0−<π |(ud)RuL|p>0<π |(ud)LuL|p>0<K |(us)RuL|p>0<K |(us)LuL|p>+−<K |(us)RdL|p>+<K |(us)LdL|p>+−<K |(ud)RsL|p>+<K |(ud)LsL|p>+−<K |(ds)RuL|p>+−<K |(ds)LuL|p><η|(ud)RuL|p><η|(ud)LuL|p>0

directindirect

0.05

0.1
2
W0 [GeV ]

0.15

0.2

Fig. 2. Relevant form factors W0 of the proton decay matrix elements in the quenched approximation. Operators have been matched to MS, NDR at µ = 2 GeV to
NLO, using NPR.

factor of 2, which shortens the proton lifetime by afactor of 4.
There could still be a systematic error due toquenched approximation. To remove it, we need toperform the direct calculation with the three-flavor dynamical fermions. As a first step toward this ultimate
goal, we have investigated the dynamical fermion effects on the low energy parameters using the two-flavor
dynamical DWF configurations. So far, the values are
consistent with those with the quenched approximation,1) although the statistical errors are still large.
References
1) Y. Aoki et al., Phys. Rev. D75 (2007) 014507.

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1

RIKENAccel.
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)RIKEN

Lattice QCD with dynamical overlap fermions
JLQCD Collaboration: S. Aoki,∗1 H. Fukaya,∗2 S. Hashimoto,∗3,∗4 K.-I. Ishikawa,∗5 K. Kanaya,1 T.
Kaneko,∗3,∗4 H. Matsufuru,∗3 K. Ogawa,∗6 M. Okamoto,∗3 M. Okawa,∗5 T. Onogi,∗7 A. Ukawa,∗1,∗8 N.
Yamada,∗3,∗4 and T. Yoshie,∗1,∗8[Lattice gauge theory, chiral symmetry]

∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Graduate School of Pure and Applied Sciences, Universityof Tsukuba
Theoretical Physics Laboratory, RIKENHigh Energy Accelerator Research Organization (KEK)
School of High Energy Accelerator Science, The Graduate
University for Advanced Studies(Sokendai)
Department of Physics, Hiroshima University
Department of Physics, National Taiwan University
Yukawa Institute for Theoretical Physics, Kyoto University
Center of Computational Science, University of Tsukuba

chiral perturbation theory at tree level;m2PS ∝ msea Σ/Fπ2 ,(1)

where m2PS is the pion mass, msea is the quark mass, Σdenotes the chiral condensate and Fπ is the pion decay
constant.
The exact and quantum-level chiral symmetry has
been achieved by the overlap Dirac operator and the
topology preserving determinant in the numerical simulations. Many dramatic results are expected to appear soon3–6) .

2

0.2

MPS

The lattice gauge theory has become one of the standard methods to evaluate the non-perturbative phenomena of QCD. In the previous works, many lowenergy quantities, such as hadron spectrum, matrix
elements etc. have been calculated by the numerical simulations. Their results, however, have sizable
uncertainties due to the use of Dirac operator which
breaks chiral symmetry and the diﬃculty in reaching
the chiral limit.
Although it is known that the overlap Dirac operator(the overlap fermion) can realize an exact chiral symmetry on the lattice, no numerical study with Nf 6= 0
dynamical quarks could employ it so far except for verysmall size lattices, because of the large numerical costof the overlap Dirac operator itself, and another theoretical problem that the fermion determinant is notcontinuous, which requires an extra numerical cost proportional to the volume squared.
The latter problem is due to the fact that the QCD
vacuum is a mixture of diﬀerent topological sectors.
In 1), we studied several gauge actions that automatically satisfy Lüscher’s admissibility condition which
require the lattice gauge ﬁelds to be smooth and the
topological charge to be conserved. We found the additional 2-ﬂavor Wilson fermion and ghost with a cut-oﬀ
scale mass can completely prevent the discontinuity of
the fermion determinant and their eﬀect on the lowenergy is small.
At KEK, the supercomputer was replaced by a multiple system of Hitachi SR11000 and IBM Blue Gene/Lwith a total peak speed of around 60TFLOPS. Now, we
can perform the dynamical overlap fermion simulations
with our topology preserving method. We have carriedout the large-scale simulations with 2-ﬂavor overlap
quarks with sea quark masses down to quarter of thestrange quark mass or smaller2) . The lattice size is
163 × 32 and the lattice spacing is around 0.125fm. As
one of preliminary results, the pion mass is plotted in
Fig.1, which shows the chiral behavior is really goodand consistent with the well-known prediction of the

0.1

0.0
0

0.05

msea

0.1

Fig. 1. Chiral extrapolation of the pseudo-scalar (pion)
mass.

References
1) H. Fukaya, S. Hashimoto, K. I. Ishikawa, T. Kaneko,
H. Matsufuru, T. Onogi and N. Yamada [JLQCD Collaboration], Phys. Rev. D 74, 094505 (2006) [arXiv:heplat/0607020].
2) T. Kaneko et al. [JLQCD Collaboration], arXiv:heplat/0610036.
3) N. Yamada et al. [JLQCD Collaboration], “Mobility
edge and locality of the overlap-Dirac operator with andwithout arXiv:hep-lat/0609073.
4) S. Hashimoto et al. [JLQCD Collaboration], arXiv:heplat/0610011.
5) H. Fukaya et al. [JLQCD Collaboration], arXiv:heplat/0610024.
6) H. Matsufuru et al. [JLQCD Collaboration], arXiv:heplat/0610026.

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Rep. 4039 (2007)(2006)

Overlap lattice fermion in a gravitational field†
M. Hayakawa,∗1 H. So,∗2 and H. Suzuki[Lattice gauge field theories, anomalies in field and string theories, lattice models of gravity]
In any sensible constructive definition of quantum
gravity by discretized space-time, the quantum effects
of matter fields should correctly be incorporated. In
the context of lattice gauge theory, it is known that lattice Dirac operators that satisfy the Ginsparg-Wilson(GW) relation1) can naturally incorporate the nontrivial quantum effects of fermions such as the axial
anomaly and the Dirac operator index, even with finite lattice spacings.2–4)
In the present work, as a generalization of that of
the lattice gauge theory, we constructed a lattice Dirac
operator of the overlap type3) that describes the propagation of a Dirac fermion in an external gravitational
field. The local Lorentz symmetry can be manifestly
realized on the lattice as
ψ(x) → ψ(x)g(x)−1 ,U (x, µ) → g(x)U (x, µ)g(x + µ̂)−1 ,X
γ µ (x) ≡eµa (x)γ a → g(x)γ µ (x)g(x)−1 ,ψ(x) → g(x)ψ(x),aeµa (x) →1 X
tr{γa g(x)γ b g(x)−1 }eµb (x),
2n

(1)

b

D = 1 − A(A† A)−1/2 ,A ≡ 1 − Dw ,(2)

where Dw is a Wilson-type lattice Dirac operator
1
1{6 ∇ + 6 ∇∗ − (6 ∇∗ 6 ∇ + 6 ∇6 ∇∗ )},
2
2

(3)

with covariant differences (e(x) ≡ detµ,a {eaµ (x)})
Xγ µ (x){U (x, µ)ψ(x + µ̂) − ψ(x)},6 ∇ψ(x) ≡µ∗

6 ∇ ψ(x) ≡Xe(x)−1 e(x − µ̂)× U (x − µ̂, µ)−1 γ µ (x − µ̂)U (x − µ̂, µ)× {ψ(x) − U (x − µ̂, µ)−1 ψ(x − µ̂)}.

(4)

The lattice Dirac operator D satisfies the conventional
GW relation
γ5 D + Dγ5 = Dγ5 D.
∗1
∗2

µ

a lattice analogue of the metric condition in the continuum.
Because of the above properties of D, the latticeindex theorem in the presence of a gravitational field½¾
X
1
tr Γ5 (x, x) = n+ − n− , Γ5 ≡ γ5 1 − D ,(8)2xwhere n± denote the numbers of zero eigenmodes withpositive and negative chiralities, respectively, holds.
Moreover, the classical continuum limit of the index
reproduces the Dirac genus5) asX
lim a2ntr Γ5 (x, x)
x

Z
=

det
M2n

(

iR̂/4πsinh(iR̂/4π)

)1/2
,

(9)

where R̂ denotes the curvature 2-form.
Similar results are obtained for other Lorentz representations, such as the spinor-vector and the bispinor
representations. In the paper, reduction to a single
Majorana fermion is also considered and it was observed that the reduction is possible for 8k + 2 and8k + 4 dimensions, but not for 8k dimensions, as isconsistent with the existence of Witten’s global gravitational/gauge anomalies in 8k dimensions. Matterfields with a definite chirality are also briefly considered along the lines of ref. 6).
References

µ

†

x

which is suggested by the general coordinate invariance, provided that the external vielbein and link variables satisfy the constraintX∇∗µ {e(x)γ µ (x)} = 0, for all x,
(7)

a→0

where the link variables U (x, µ) and the gauge transformations g(x) take the values in G = spin(2n), while
it is believed that the general coordinate invariance isrestored only in the continuum limit. Our doubler-freelattice Dirac operator is given by

Dw =It also possesses γ5 -hermiticity D† = γ5 Dγ5 with respect to the inner product,X(f, g) ≡e(x)f (x)T ∗ g(x),
(6)

(5)

Condensed from the article in Prog. Theor. Phys. 116, 197(2006).
Department of Physics, Nagoya University
Department of Physics, Ehime University

1) P. H. Ginsparg and K. G. Wilson: Phys. Rev. D 25,
2649 (1982).
2) P. Hasenfratz, V. Laliena and F. Niedermayer: Phys.
Lett. B 427, 125 (1998).
3) H. Neuberger: Phys. Lett. B 417, 141 (1998); Phys.
Lett. B 427, 353 (1998).
4) M. Lüscher: Phys. Lett. B 428, 342 (1998).
5) See for example, K. Fujikawa and H. Suzuki: Path Integrals and Quantum Anomalies (Oxford Univ. Press,
Oxford, 2004).
6) M. Lüscher: Nucl. Phys. B 549, 295 (1999); Nucl. Phys.
B 568, 162 (2000).

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Gauge anomaly associated with the Majorana fermion in 8k + 1
dimensions†M. Hayakawa∗1 and H. Suzuki·

Gauge field theories, symmetry and conservation laws, field theories in dimensions otherthan four

The Majorana fermion in 8k + 1-dimensional
Minkowski space-time is very peculiar. The charge
conjugation matrix is symmetric, C T = +C, in 8k + 1
dimensions and only a possible Lorentz invariant massterm for a single Majorana fermion, mψ T C −1 ψ, identically vanishes. This implies that one cannot apply thegauge invariant Pauli-Villars regularization to a single
Majorana fermion. This situation generally persists
for an odd number of Majorana fermions. A similar
phenomenon is also found with the lattice regularization.1) The most impressive example is given by the
1-dimensional (k = 0) case, i.e., quantum mechanics,
for which a lattice action of a free Majorana fermion ψein the momentum space would beZ π/aee ψ(p),
dp ψeT (−p)D(p)
(1)
−π/a

where a denotes the lattice spacing. Since ψe iseGrassmann-odd, the kernel D(p)must be odd underep ↔ −p. Also, D(p) must be periodic in the Brillouine + 2π/a) = D(p)ezone D(pfor locality. These two requirements, however, imply that the kernel inevitably
possesses a zero at p = π/a, that corresponds to thespecies doubler. Thus, one cannot write down a latticeaction of a free single Majorana fermion which is consistent with locality, at least in the form of the ansatz
Eq. (1).
These “phenomenological” observations strongly
suggest the existence of some sort of anomaly associated with the Majorana fermion in 8k + 1 dimensions. Since there is no perturbative (or local) gauge
anomaly in these odd dimensions, one expects thatsomething similar to the global gauge anomaly in evendimensional spaces2,3) occurs. This possibility has
been suggested in ref. 4) and the global gravitational
anomaly for the Majorana fermion in these dimensions has been demonstrated.5) Also, the global gauge
anomaly associated to the Majorana fermion in 1 dimension (k = 0) has been known6) . To our knowledge,
however, no examples of the global gauge anomaly associated with the Majorana fermion in higher (k ≥ 1)
dimensions have thus far been given.
In this work, using an elementary argument, wegive an example of the gauge anomaly for the Majorana fermion in 8k + 1 dimensions. Our construction†∗1

Condensed from the article in Prog. Theor. Phys. 115, 1129
(2006).
Department of Physics, Nagoya University¸

works for the Majorana fermion in the (N, 8v , . . . , 8v )representation of the gauge group SO(N ) × SO(8)k(N ≥ 3). The topology of the base space is taken
to be S 1 × S 8 × · · · × S 8 . Basically the construction
takes the following steps.
First, we explicitly solve the eigenvalue problem ofa one-dimensional Dirac operator D1 on S 1 (i.e., thek = 0 case) and show that the Majorana pfaffian
Pf{iD1 } changes the sign under a certain SO(N ) gaugetransformation. This global gauge anomaly in one dimension implies that the two-dimensional Dirac opera∂
tor D
6 2 = σ 2 ∂x
+σ 1 D1 with an appropriate gauge field0
possesses an odd number of right-handed zero modes.
Second, we consider an 8k + 2-dimensional Dirac operator D
6 8k+2 whose odd number of right-handed zeromodes implies the global gauge anomaly in 8k + 1 dimensions. We then assume an appropriate gauge-field
configuration which allows a separation of variables††
such as D
6 8k+2D
6 8k+2 = D
6 2†D
6 2 ⊗ 1 + 1 ⊗D
6 8k
D
6 8k . Thenthe number of right-handed zero modes of D
6 8k+2 is odd
if and only if the index of the 8k-dimensional Dirac operator D
6 8k is odd. Finally, through the index theoremZ1index{i6D8k } =tr{F 4k },(2)(2π)4k (4k)!
we show that index{i6D8k } is odd for a collection of kSO(8) instantons7) on S 8 × · · · × S 8 . For all the technicalities, the interested readers are referred to the original paper. We are expecting interesting applicationsof our observation in quantum mechanics (k = 0) andin string theory (k = 1).
References
1) T. Inagaki and H. Suzuki: J. High Energy Phys. 0407,
038 (2004). H. Suzuki: Prog. Theor. Phys. 112, 855(2004).
2) E. Witten: Phys. Lett. B 117, 324 (1982).
3) S. Elitzur and V. P. Nair: Nucl. Phys. B 243, 205(1984).
4) L. Alvarez-Gaumé and E. Witten: Nucl. Phys. B 234,
269 (1984).
5) E. Witten: Commun. Math. Phys. 100, 197 (1985).
6) D. Friedan and P. Windey: Nucl. Phys. B 235, 395(1984). E. Witten: “Global anomalies in string theory,” Proc. Argonne Symp. on Geometry, Anomalies
and Topology, Argonne, IL, Mar 28-30, 1985.
7) B. Grossman, T. W. Kephart and J. D. Stasheff: Commun. Math. Phys. 96, 431 (1984) [Errata, 100, 311(1985)]. D. H. Tchrakian: Phys. Lett. B 150, 360(1985).

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Note on massless bosonic states in two-dimensional ﬁeld theories†
H. Fukaya, M. Hayakawa,∗1 I. Kanamori, H. Suzuki and T. Takimi∗2[Symmetry and conservation laws, chiral symmetries, currents and their properties]
Obtaining a constructive deﬁnition of supersymmetric ﬁeld theory, which allows nonperturbative study,
has been a long-standing problem in theoretical particle physics. Our group1) is now undertaking latticeMonte-Carlo simulations of the two-dimensional (2d)N = (2, 2) supersymmetric Yang-Mills (SUSY YM)
theory, on the basis of the recent proposal in ref. 2).
For such a numerical study, any theoretical information on the property of the target theory is highly welcome. The present work is a by-product, obtained in
the process of seeking some exact statement on the 2d
N = (2, 2) SUSY YM theory.
In this work, we consider 2d super-renormalizableﬁeld theories (not necessarily supersymmetric)
1 A Aµν1
L = ¡ FµνF
+ ψiγ µ Dµ ψ + Dµ σDµ σ
421+ Dµ πDµ π ¡ Y (ψ, ψ, σ, π) ¡ V (σ, π), (1)2where Y is the Yukawa interaction and V is the scalarpotential. We assume that L is parity-invariant withthe assignment that σ is a scalar and π is a pseudoscalar. We also assume that L possesses GL × GR
global symmetry, namely, with suitable transformations on scalar ﬁelds σ and π, and that L is invariant
under (writing ψR,L = {(1 ± γ5 )/2}ψ)a a
ψL (x) → exp{iθL
T }ψL (x),a a
ψR (x) → exp{iθR T }ψR (x),(2)

where T a are hermitian generators of a compact Liegroup G in the representation R. Then we showed
that, irrespective of the details of the system, the oddparity part of the two-point function of Noether curarents associated with the GL × GR symmetry, JL,µ(x)aand JRµ (x), can be determined up to all orders of perturbation theory asaF.T.h0|T ∗ J5µ(x)Jνb (y)|0ii= ¡ (dim r)T (R)δab
2π
{
}
1
ρ
ρ
2
×
(pµ ²νρ p + pν ²µρ p ) + L(p )²µν ,
p2

(3)

a
a
a
a
a
where Jµa ≡ JR,µ+ JL,µand J5µ≡ JR,µ¡ JL,µ. In theabove expression, dim r is the dimension of the gaugegroup representation r of the fermion and T (R) is thesecond Casimir of the representation R of the ﬂavor†∗1∗2

Condensed from the article in Prog. Theor. Phys. 116, 1117
(2007).
Department of Physics, Nagoya University
Yukawa Institute for Theoretical Physics, Kyoto University

group G. L(p2 ) is an undetermined scalar function.
The proof of the statement is based on the (anomalous)
Ward-Takahashi identities and power counting.
The two-point function exhibits a massless pole, that
corresponds to massless bosonic physical states. Thus,
there is no mass gap in the above system. We notethat the massless pole in the two-point function ofconserved currents does not contradict with Coleman’s
theorem that prohibits a massless pole between a scalarﬁeld and the conserved current in two dimensions.
The above statement covers all known superrenormalizable examples, such as the multiﬂavor
Schwinger model, the 2d massless QCD, and the
Kogut-Sinclair model, in which the existence of massless bosonic states has been shown by other methods. The statement applies, in particular, to the 2d
N = (2, 2) SUSY YM theory (our original target) in
which
{
}
2
Y = g tr ψ [σ + iγ5 π, ψ] , V = ¡g 2 tr{[σ, π] },(4)and which possesses U(1)L × U(1)R symmetry. The
same is true even with matter multiplets, as long as
there is no superpotential. Similarly, the N = (4, 4)
SUSY YM theory possesses SU(2)L × SU(2)R symmetry and our statement applies. The fact that N =(2, 2) and N = (4, 4) SUSY YM theories have no
massgap has been noted3) on the basis of the ’t Hooft
anomaly matching argument.
For the 2d N = (2, 2) SUSY YM theory with thegauge group SU(Nc ), the two-point function in the (euclidean) position space is given by
hJ5µ (x)Jν (y)ii1
= ¡ 2 (Nc2 ¡ 1) 2 2 (rµ ²νρ rρ + rν ²µρ rρ ),
2π
(r )

(5)

for x 6= y, where rµ = xµ ¡ yµ . Moreover, a supersymmetric Ward-Takahashi identity shows that (ifsupersymmetry is not spontaneously broken) a twopoint function of certain fermionic operators also exhibits a power-law behavior, corresponding to a massless fermionic state. At present, we are measuring thistwo-point function in Monte-Carlo simulations to examine the restoration of supersymmetry in the continuum limit, which was suggested in ref. 2).
References
1) H. Fukaya, I. Kanamori, H. Suzuki, T. Takimi and
Y. Taniguchi: work in progress.
2) H. Suzuki and Y. Taniguchi: J. High Energy Phys.
0510, 082 (2005).
3) E. Witten: Nucl. Phys. B 460, 335 (1996).

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RIKEN Accel. Prog. Rep. 40 (2007)

Hermiticity and Majorana condition for two-dimensional superYang-Mills model on a lattice with Dirac-Kähler twist
A. D’Adda,∗1 I. Kanamori, N. Kawamoto,∗2 K. Nagata,∗3 and J. Saito∗2[supersymmetry, lattice, Hermiticity]
Supersymmetry (SUSY) provides a unified description of bosons and fermions but it lacks a regularizationthat maintains the SUSY in general. One of the mostpowerful regularizations is a lattice regularization thattreats space-time as a discrete space. Among the many
attempts to provides a lattice formulation for SUSY,
we previously proposed a lattice formulation for a super Yang-Mills model with a Dirac-Kähler twist andwith a kind of noncommutativity1) . We report ourrecent development of the Hermiticity and Majorana
condition of our model2) .
We used supercharges on lattice links and discretized
the algebra in the previous model. The essential difficulty in formulating SUSY on the lattice comes fromthe fact that the supertransformation is the square rootof an infinitesimal translation, whereas on the lattice
we have only finite translations. Geometrically, the finite translations correspond to links on the lattice, sothat it is very natural to place the supercharges onlinks. With the help of the kind of noncommutativity, which is closely related to the link structure, we
succeeded in discretizing the algebra. Our algebra is
two-dimensional N = 2 algebra with a Dirac-Kähler(or topological) twist.
In conventional lattice gauge theory, the gauge field
exists on a link as an exponentiated field (link variable). On the oppositely oriented link, its Hermitian
conjugate exists. The fact that the gauge field is realshows that the link variable is unitary. In this report,
we discuss a similar relation for the supercharges on alink.
We have four supercharges in the model, which is˜ ∇1 and ∇2 . We can locate a pairgenerated by ∇, ∇,˜(∇, ∇) on the same link but with opposite orientation
to each other (Fig. 1). The situation is the same forthe (∇1 , ∇2 ) pair as well as for the bosonic pair of linkfields (U+µ , U−µ ), where U±µ gives the forward and˜backward differences. Therefore, we identify ∇† = ∇†and ∇1 = ∇2 . These relations are exactly those of the
Majorana condition for twisted charges. This simple
identification, however, does not work easily because it
contradicts the algebra. We need to make a (counter)Wick rotation from a Euclidean to a Lorentzian signature. Eventually, we obtain the following algebra:{∇, ∇1 } = iU+1 ,
∗1
∗2
∗3

˜ ∇1 } = iU −1 = iU−1 ,{∇,INFN Torino and Torino University, Italy
Department of Physics, Hokkaido University
Department of Physics, Indiana University, USA

˜ ∇1 } = −iU −2 = iU−2 .
{∇,{∇, ∇2 } = iU+2 ,(2)

The twisted charges can be untwisted to normal
spinor charges through
˜ 5 C −1 ,∇iα = ∇C −1 + i∇µ γ µ C −1 + ∇γ
(3)iαwhere α is a SO(1,1) spinor suffix of space-time, i isa SO(1,1) spinor suffix of R-symmetry (internal symmetry) and C is a charge conjugation matrix. Since
the spinor charges are given as a linear combinationof charges on different links, they cannot be kept exact on the lattice. Note that because the twist operation mixes the space-time and internal space of the
R-symmetry, Wick rotation in the twisted space-timeleads to that of the untwisted space-time and the internal space. Using the Dirac conjugation∇jβ= (∇iα )∗ (γ 0 )i j (γ 0 )α β ,(4)we obtain the Majorana condition for the spinor
charges−1 jβ∇(5)∇iα = (γ 5 C −1 )ij Cαβ
and the algebra
jβ{∇iα , ∇ } = −2(γ 5 )i j (γ µ )α β ∇µ + 2(γ 5 γ a )i j δα β φa ,(6)
where ∇µ is a space-time covariant derivative and φa
is a scalar field in the SUSY multiplet.
Finally, a different treatment of the Hermiticity requires that the number of charges should be doubled
in general. That kind of treatment may be related to
N = 4 multiplet.
References
1) A. D’Adda, I. Kanamori, N. Kawamoto and K. Nagata:Phys. Lett. B 633, 645 (2006).
2) A talk given by I.K in Joint Meeting Pacific Region
Particle Physics Communities, Honolulu, USA, 200610. A related paper is in preparation.
˜
∇2
∇
∇

∇2
∇1

(1)

∇1
U−1
U+1
˜
∇
∇

˜ ∇2 } =Fig. 1. Link structure for {∇, ∇1 } = iU+1 and {∇,˜iU−1 . (∇, ∇), (∇1 , ∇2 ) and (U+1 , U−1 ) are located on
the same but oppositely oriented links.

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RIKEN
Accel.
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Nonlocal Matching Condition and Scale-invariant Spectrum in
Bouncing Cosmology†
C. S. Chu,∗1 K. Furuta and F. L. Lin,∗2[Models in early universe, General relativity, Noncommutative geometry]
In cosmological scenarios such as the pre-big bang or
ekpyrotic scenario1,2) , a matching condition between
the metric perturbations in the pre-big bang phaseand those in the post-big bang phase is often assumed.
Nevertheless, obtaining a scale invariant cosmic microwave background (CMB) spectrum via a concretemechanism remains impossible. We examine this problem from the point of view of local causality. We prove
the following no-go theorem: independent of the details of the matching condition, a scale-invariant spectrum is impossible as long as the local causality condition is satisfied. By considering nonlocal effects ofnoncommutative field theory, we consider the possibility of obtaining a scale-invariant spectrum.
We consider a scalar field ϕ coupled to gravity. Consider spacelike hypersurfaces S− and S+ separated by
the bounce where the former is before the bounce andthe latter is after it. Local causality requires that there
exists a finite region Ω− on S− such that the metric0, ϕ, ϕ0 } at P 0 on S+ isand the scalar field data {gij , gij
0determined only by data {gij , gij , ϕ, ϕ0 } on Ω− , modulo local spatial coordinate transformation (Fig. 1).

 

 


Fig. 1. Local causality

The matching condition takes the form¯¯
0gij ¯η=η ,P 0 = Hij (gij , gij, ϕ, ϕ0 , ∇k )¯η=η ,P .
+

−

(1)

The function Hij is a rank 2 symmetric tensor. We caneliminate extra coordinate dependence by choosing a
map from S− to S+ appropriately. We expand (1) inthe wave number k. This is in the same principle usedin the method of spatial gradient expansion3) . However, the validity of a four-dimensional effective theory
during the bounce is not assumed in our approach.
The gauge-invariant metric fluctuation is given by¶µ22H
Φ = S(k) l 2 + O(k )
a
†
∗1
∗2

Condensed from the article in Phys. Rev. D. 73, 103505(2006)
Centre for Particle Theory and Department of Mathematics,
University of Durham, UK
Department of Physics, National Taiwan Normal University,
Taiwan

Ã µ Z
!
¶0
1 1
2
2
+D(k)
dηa
+ O(k ) .
a a

(2)Here, a is the scale factor and H ≡ a0 /a is the Habble
parameter. l stands for the Planck scale. The coefficients S(k) and D(k) are time-independent.
Using the explicit form of the metric fluctuation andthe matching condition (1), the coefficients S (+) andD(+) after the bounce is given byµ (+) ¶ µ
¶ µ (−) ¶
S
CS CD
S
=
(3)
2
(+)
Ak
1
D
D(−)
with undetermined coefficients CS and CD . Thus,
we have obtained the matching condition. To obtainthe scale-invariant CMB spectrum, the constant mode
D(+) must behave as D(+) ∼ k −3/2 . For the ekpyrotic
and cyclic scenario, it is known that
S (−) ∼ k −3/2 and D(−) ∼ k −1/2 .

(4)

We conclude that nonlocal causality is necessary toobtain a scale-invariant spectrum. A similar analysis
can be carried out for the pre-big bang scenario.
In string theory, nonlocal effects such as noncommutativity of the space-time are known. For example, inthe noncommutative ϕ4 theory, the low-energy effective action provides a nonlocal term4)
Leff ∼

1
g2
ϕ(k)ϕ(−k), (5)2 96π 2 (|ki (θ2 )ij kj |/a2 + Λ12 )where θij is the noncommutative parameter. The time
evolution of ϕ has nonlocal effects if the ultraviolet
cutoff scale Λ is taken to infinity.
By modifying the time evolution of the metric fluctuation to include the 1/k term, it is possible to obtainthe scale-invariant power spectrum with the magnitudeµ ¶2l
P (k) ∼.
(6)lb
Here, lb is the noncommutative scale. Thus, the Hubble scale around which the bounce occurs should be ataround 10−5 of the Planckian energy scale.
References
1) M. Gasperini and G. Veneziano: Astropart. Phys. 1,
317 (1993).
2) J. Khoury, B. A. Ovrut, P. J. Steinhardt, and N. Turok:
Phys. Rev. D 64 (2001) 123522.
3) J. Parry, D. S. Salopek, and J. M. Stewart: Phys. Rev.
D 49, 2872 (1994).
4) S. Minwalla, M. Van Raamsdonk, and N. Seiberg:
JHEP 0002, 020 (2000).

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RIKENRIKENAccel.
Accel.Prog.
Prog. Rep.
Rep. 40
39(2007)(2006)

Field Equations of Massless Fields Based on the New Interpretationof Matrix Models †M. Hanada,∗1 K. Furuta, H. Kawai, and Y. Kimura,∗2[String theory, Matrix model, General relativity]
Recently, some of the authors have introduced a
new interpretation of matrix models in which covariant derivatives can be expressed by large-N matrices1) .
In this interpretation, the Einstein equation is derived
at the classical level. We generalize this argument tocovariant derivatives with torsion. Some componentsof the torsion field can be identified with the dilaton
and the B-field in string theory. However, the othercomponents do not seem to have string theory counterparts. We also consider the matrix model with amass term or a cubic term, in which the equation of
motion in string theory is exactly satisfied.
We consider the large-N reduced modelµ¶£ a b¤
1
S = − 2 T r [Aa , Ab ] A , A,(1)4g
which is the bosonic part of the IIB matrix model2) .
Aa are N × N Hermitian matrices and a and b run
from 1 to d. The gauge transformation is given by
δAa = i[Λ, Aa ], where Λ is an N ×N Hermitian matrix.
We consider that the matrices Aa act on the spaceof functions on the principal Spin(d) bundle over the
space-time manifold1) . The covariant derivative ∇a isshown to be mapped to a set of matrices ∇(a) by∇(a) = R(a) b (g −1 )∇b¡¢= R(a) b (g −1 )eb µ (x) ∂µ + ωµ cd (x)Ocd ,(2)where g is the coordinate of the fiber Spin(d),R(a) b (g −1 ) is the vector representation of Spin(d) andOab is the Lorentz generator of the Spin(d) group.
Aa can be expanded as a series in powers of ∇(a) andOab . By introducing contorsion Sa bc (x), we consider
the general form of the first-order differential operator
Aa = iR(a) b (g −1 )Db= iR(a) b (eb µ (x)∇µ + Sb cd (x)Ocd ).

(3)

The gauge parameter at the first-order in the differential operator Λ = iλµ (x)∇µ + iλab (x)Oab generates
the diffeomorphism and the local Lorentz transformation and fixes the unphysical modes of ea µ (x). However, no components of the contorsion Sa bc (x) can begauged away. The equation of motion reduces to thefollowing two equations:−Rbc + Da Tabc + Tab d T a dc = 0,
†
∗1
∗2

(4)

Condensed from the article hep-th/0611093
Department of Physics, Kyoto University
Department of Physics, Queen Mary, University of London,UK

Da Rab cd + T a b e Rae cd = 0.

(5)cd

where Tabc = Sabc −Sbac is the torsion and Rab is the
Riemann tensor with the contribution from the torsion.
We solve the equations of motion Eqs. (4) and (5)at the linearized level. The contorsion Sa bc can be
decomposed to irreducible tensors as
Sabc = Vb δac − Vc δab + Labc + Habc ,(6)where Habc is antisymmetric and Labc satisfies the relations L[abc] = 0 and La ac = 0. Since no componentof the contorsion Sa bc (x) can be gauged away, negative norm modes appear in Sa bc (x). For this reason,
we regard Sa bc (x) as the field strength and consider
the following form of solutions:
Va = ∂a φ,
Habc = ∂[a Bbc] ,Labc = 0.

(7)
(8)
(9)

Then, the equations of motion reduce to
Rab = (3 − d)∂a ∂b φ,∂ 2 φ = 0,
∂ a Habc = 0.

(10)
(11)
(12)

These equations are the same as the linearized equations of motion for the system of the dilaton and theantisymmetric B-field coupled to gravity, which arise
naturally from the string theory.
Although we have considered solutions that satisfy
the conditions Eqs. (7)-(9), there are many solutions
that do not satisfy these conditions. Any solution of
the linearized equations can be shown to be extended
to solutions to higher orders. None of the solutions in
the linear order can be discarded. It seems that the
space of the matrix needs to be restricted in some way
to enable a physical interpretation of the result.
We can generalize the analysis to a model with amass term and a cubic term. In those cases, the equation of motion is satisfied by the covariant derivativeon a group manifold which satisfy[Da , Db ] = αfabc Dc .

(13)

The structure constants are identified with the fieldstrength of the B-field.
References
1) M. Hanada, H. Kawai, and Y. Kimura: Prog. Theor.
Phys. 114 (2006) 1295.
2) N. Ishibashi, H. Kawai, Y. Kitazawa, and A. Tsuchiya:
Nucl. Phys. B498 (1997) 467.

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RIKEN Accel. Prog. Rep. 40 (2007)

Improved perturbation method and its application to matrix models
T. Aoyama, H. Kawai, T. Kuroki, and Y. Shibusa[String theory, Matrix model, Nonperturbative analysis]
String theory is the unique theory that contains
massless spin-two particles, i.e. gravitons, and is thus
considered to provide unified microscopic descriptionof the universe including gravity. However, it has beenrecognized that perturbative string theory fails to single out our universe as the unique vacuum of the theory. Therefore, we are forced to pursue nonperturbative formulations. The IIB matrix model (also called
the IKKT matrix model)1) has been proposed as a constructive formulation of the superstring theory, and it
has been subjected to intensive studies.
A significant feature of the IIB matrix model is thatthe space-time itself is expressed by the eigenvalue distribution of ten bosonic matrices, and thus it is treatedas a dynamical variable of the model. The origin of
our four-dimensional space-time can be argued in thisframework by a spontaneous breakdown of the Lorentz
symmetry. It is also of great importance to clarify
whether the non-Abelian gauge group of the standard
model type emerges dynamically in the context of matrix models. It is natural that this gauge group is embedded in the original U (N ) gauge group of the matrix
model. We are thus motivated to investigate the dynamical aspects of matrix models in a nonperturbative
manner.
It is generally believed that the perturbative series
expansion is asymptotic and diverges beyond some finite order. Nevertheless, for most theories, we canonly evaluate such series expansions, from which wehave to deduce as much information as possible on thetheory. Therefore, we need a method for estimating
the exact values of observables at the parameter values (coupling constants and other parameters) outside
the original radius of convergence. We employ here
an optimization technique, which we refer to as the
improved perturbation method.2)
The concrete procedure of the improved perturbation method is as follows. Assuming that we have aperturbative series F (λ, m), where λ is a coupling constant and m denotes a parameter of the model, we
perform a shift of parameters that involves an artificial parameter m0 ,λ −→ g λ,m −→ m0 + g(m − m0 ).

(1)

Then we reorganize the series in terms of g, truncate
it at a finite order of g, and set g to 1. Although g = 1
means that this manipulation is nominal, the series
turns to be dependent on m0 by the truncation at somefinite order of g. To determine the optimal value of m0 ,we adopt here the principle of minimal sensitivity. Itmeans that the exact value of F would be reproduced
when the dependence on the artificial parameter m0of the improved series becomes weakest. Thus far, theimproved perturbation method is considered as a sortof resummation of the series by a variational approach.
We have investigated this method in detail.3) In particular, we developed an efficient prescription to extract
the approximate values of observables when the model
contains many parameters.
We applied the improved perturbation method to
the IIB matrix model and examined the spontaneous
breakdown of the ten-dimensional rotational symmetry.3–5) We considered configurations in which theSO(d) subgroup of SO(10) stays intact as the ansatz.
By comparing the estimated values of the free energy
based on the perturbative series expansion up to the
8th order, we found that the SO(4)-symmetric configuration, in which the extended four-dimensional spacetime is realized, is preferred.3,4) We also examined theextended ansatz to confirm the above result.5) Thus,
we conclude that the IIB matrix model has a solution
with four-dimensional rotational symmetry, which corresponds to our universe as a nonperturbative vacuum.
To study whether a spontaneous breakdown of
U (N ) gauge symmetry occurs in the matrix models in
the large-N limit, we examined the massive Yang-Mills
Chern-Simons matrix model as a simplified bosonicmodel by the improved perturbation method.6) It has
been claimed that this model has several phases withrespect to the coupling constant of the Chern-Simons
term α and the mass parameter m2 . We studied thephase structure and confirmed in a nonperturbative
manner that a phase called the 5-brane phase, in which
the configuration consists of O(N ) coincident small
fuzzy spheres, is realized. This implies that the nonAbelian gauge group of rank N is generated dynamically.
References
1) N. Ishibashi, H. Kawai, Y. Kitazawa, and A. Tsuchiya:
Nucl. Phys. B 498, 467 (1997).
2) J. Nishimura and F. Sugino: JHEP 0205, 001 (2002);
H. Kawai, S. Kawamoto, T. Kuroki, T. Matsuo, andS. Shinohara, Nucl. Phys. B 647, 153 (2002).
3) T. Aoyama and Y. Shibusa: Nucl. Phys. B 754, 48(2006).
4) T. Aoyama and H. Kawai: Prog. Theor. Phys. 116, 405(2006).
5) T. Aoyama, H. Kawai, and Y. Shibusa: Prog. Theor.
Phys. 115, 1179 (2006).
6) T. Aoyama, T. Kuroki, and Y. Shibusa: Phys. Rev. D
74, 106004 (2006).

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RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

Non-Abelian duality from vortex moduli
M. Eto,∗1 L. Ferretti,∗2 K. Konishi,∗3,∗4 G. Marmorini,∗5,∗4 M. Nitta,∗6 K. Ohashi,∗7 W. Vinci,∗3,∗4 and N. Yokoi[Non-Abelian duality, magnetic monopole and vortex, supersymmetric gauge theory]
The mechanism of quark confinement and chiral symmetry breaking in quantum chromodynamics (QCD) still remains mysterious. Supersymmetricgauge theories provide a promising clue to understanding the problem. Actually, a non-Abelian version of thedual Meissner effect in supersymmetric gauge theories
has been proposed as a good model for quark confinement occuring in QCD1) .
An example of a non-Abelian extension of theelectric-magnetic duality is the GNOW duality conjectured by Goddard-Nuyts-Olive and Weinberg2) . Ina system where the gauge symmetry is spontaneously
broken G → H (H is a non-Abelian subgroup of G),
degenerate magnetic monopole solutions can be constructed as regular solitonic solutions. The GNOW
duality states that these monopoles form a multipletof the dual group H ∗ of unbroken H, which is genα
erated by the dual roots, α∗ ≡ α·α, where α are theroots of H. However, problems with such an interpretation are known for the simple monopole configuration, where the globally conserved charges of H cannot
be defined and the semiclassical quantization breaks
down because of non-normalizable zero modes.
In our article3) , we discuss the transformation properties of the monopole solutions in the breaking G →H by placing a low-energy system with gauge symmetry H into the Higgs phase. As a model for our idea,
we consider the softly broken N = 2 supersymmetric gauge theory, which realizes hierarchical symmetryvv
breaking, G →1 H →2 ∅ (v1  v2 ).
As a simplest example, we consider the softly broken N = 2 supersymmetric SU (N + 1) gauge theory
with Nf matter multiplets in the fundamental representation. The vacuum expectation value (VEV)
of an adjoint Higgs field, v1 breaks SU (N + 1) →SU (N ) × U (1) in a higher-energy scale and this breaking produces the solitonic monopole solutions. At
low energy, the effective theory becomes softly broken N = 2 SU (N ) × U (1) ∼ U (N ) gauge theory with
Nf fundamental matter multiplets of U (N ). Then,the VEV of the fundamental Higgs field, v2 breaks thegauge symmetry U (N ) completely. This second-stage
symmetry breaking produces the non-Abelian vortex
solutions with non-Abelian flux4) . A topological argu∗1
∗2
∗3
∗4
∗5
∗6
∗7

Institute of Physics, University of TokyoSISSA and INFN, Sezione di Trieste
Department of Physics, University of Pisa
INFN, Sezione di Pisa
Scuola Normale Superiore di Pisa
Department of Physics, Keio University
Department of Physics, Tokyo Institute of Technology

ment for the high-energy SU (N + 1) theory and thelow-energy U (N ) theory demonstrates the correspondence between the topological charges of monopoles in
π2 (SU (N + 1)/U (N )) and vortices in π1 (U (N )). As
the consequence, we are led to the monopole-vortex
coupled configuration in our full theory (see below).

M

M

It is important that our full theory has an exact
unbroken symmetry SU (N )C+F , which is the diagonal subgroup of SU (N ) gauge symmetry with SU (Nf )global symmetry for flavors. On the basis of the above
configuration, we can discuss the transformation lawof GNOW monopoles under SU (N )C+F symmetry interms of the transformation properties of non-Abelianvortices. Utilizing the moduli matrix formalism forthe vortex solutions5) , the transformation properties
of non-Abelian vortices under SU (N )C+F can be obtained. We showed that the vortices with minimum
flux transform to become the fundamental (N) representation under SU (N )C+F 6) , and determined that
GNOW monopoles with minimum magnetic charge
also transform to become the fundamental representation of SU (N )C+F . We also discussed the interpretation of SU (N )C+F symmetry as GNOW dual symmetry H ∗ ∼ U (N )∗ . Note that our analysis does notdepend on the semiclassical form of monopole solutions. Our idea SU (N )C+F ⇔ H ∗ is tested against thequantum behavior of non-Abelian monopoles in the exact low-energy effective theory à la Seiberg-Witten7) .
Generalizations to SO(N ) and U Sp(2N ) gauge theories are also discussed.
References
1) K. Konishi, G. Marmorini, and N. Yokoi: Nucl. Phys.
B741, 180 (2006).
2) P. Goddard, J. Nuyts, and D. Olive: Nucl. Phys. B125,
1 (1977); E. J. Weinberg: Nucl. Phys. B167, 500 (1980);
Nucl. Phys. B203, 445 (1982).
3) M. Eto, L. Ferretti, K. Konishi, G. Marmorini, M. Nitta,
K. Ohashi, W. Vinci, and N. Yokoi: hep-th/0611313.
4) A. Hanany and D. Tong: J. High Energy Phys. 07, 037(2003); R. Auzzi, S. Bolognesi, J. Evslin, K. Konishi,
and A. Yung: Nucl. Phys. B673, 187 (2003).
5) For a review see, M. Eto, Y. Isozumi, M. Nitta, K.
Ohashi, and N. Sakai: J. Phys. A39, R315 (2006).
6) M. Eto, K. Konishi, G. Marmorini, M. Nitta, K. Ohashi,
W. Vinci,and N. Yokoi: Phys. Rev. D74, 065021 (2006).
7) N. Seiberg and E. Witten: Nucl. Phys. B426, 19 (1994);
Nucl. Phys. B431, 484 (1994).

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RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)QCD Eﬀects in the Decays of TeV Black Holes†
C. Alig,∗1 M. Drees,∗1 and K. Oda∗2[Black hole, TeV scale gravity, Large Hadron Collider, Quark-gluon plasma]

†

∗1
∗2

Condensed from the article in arXiv:hep-ph/0610269, accepted for publication in JHEP (Journal of High Energy
Physics).
Physikalisches Institut, Universität Bonn, Germany
Theoretical Physics Laboratory, RIKEN

400

Bins

The Planck scale can be as low as TeV if we live ina four-dimensional subspace in the 4 + n dimensional
spacetime and the extra n dimensions are compactiﬁed
with a “large” radius, e.g., of the order of sub-mm forn = 2. The Randall-Sundrum scenario also predicts
that the eﬀective Planck scale is O(TeV) if we live in
the infrared (IR) brane.
In such a scenario, the CENR Large Hadron Collider(LHC), which will start taking data from the summerof 2008, will become a black hole factory—the LHC
can produce a black hole every few seconds.
The black hole is one of the most profoundly mysterious objects in theoretical physics. The black holeitself is described by the classical Einstein’s law ofgravity, yet it sits in the high-energy ultraviolet (UV)
limit to be matched with the low-energy IR stringy description according to the correspondence principle forblack holes and strings. We try to describe the production and evaporation of the black hole as precisely as
possible1) because the quantum gravitational eﬀects,
the thing which we really want to explore, will thenappear as a deviation from the black hole picture.
The black holes will decay via the Hawking radiation
mainly into the “visible” standard model ﬁelds thatare localized on our brane. The decay rate and its
energy spectrum can be computed from the greybody
factors that are calculated using the ﬁeld equations forthe brane-localized ﬁelds.1) The resulting spectrum ispeaked around the black hole temperature which isapproximately T & 100 GeV.
The Hawking radiation is proportional to the number of degrees of freedom and therefore roughly 75%of the decay products are quarks and gluons. Anchordoqui and Goldberg claimed that these quarks
and gluons will form a “chromosphere,” a quark-gluon
plasma, rather than forming distinct jets.2) The argument was that the number of the bremsstrahlung reactions, which increases the total number of partons,
makes each parton scatter O(10) times.
However, these interactions are rather soft and will
not change the energies and momenta of the participating partons very much. Such interactions would
not impede the formation of well-deﬁned hadronic jets.
Given the complexity of QCD processes, a quantitative
investigation of their eﬀect can only be performed withthe help of a QCD simulation program. For that pur-300

Scattering disabled
Scattering enabled
Chromosphere

200

1

10

100

Emax [GeV]

Fig. 1. Number of phase space cells where the depositedenergy satisﬁes E < Emax as a function of Emax , forblack hole mass M = 10 TeV. The blue, steplike curves
show the prediction from an ideal chromosphere.

pose, we wrote such a simulation code, based on the
VNI program3) . We modiﬁed it by forcing scattering
reactions to take a ﬁnite amount of time, which weestimate using the uncertainty principle.
One of our main results is shown in Fig. 1. We set
the higher dimensional Planck scale to 0.65 TeV because this maximizes the number of initial partons, andhence, the number of parton-parton interactions withina given black hole’s decay. We also consider relatively
heavy black holes with M = 10 TeV to minimize thetemperature in favor of the chromosphere formation.
We see that the number of cells with E < Emax indeed shows nontrivial dependence on Emax over a wide
range. Even for M = 10 TeV, in about 50% of thecells, almost no energy is deposited; on the other hand,about twenty cells contain more than 100 GeV. These
results are consistent with the existence of well–deﬁned
jets. Parton-parton scattering has practically no eﬀect
on the number of cells containing at least 30 GeV, again
indicating that it does not aﬀect the jet structure atall.
References
1) D. Ida, K. Oda and S. C. Park: Phys. Rev. D 67,
064025 (2003) [Erratum-ibid. D 69, 049901 (2004)][arXiv:hep-th/0212108].
2) L. Anchordoqui and H. Goldberg: Phys. Rev. D 67,
064010 (2003) [arXiv:hep-ph/0209337].
3) S. A. Bass et al.: Phys. Rev. C 60, 021901 (1999),[arXiv:nucl-th/9902055].

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RIKEN Accel. Prog. Rep. 40 (2007)

Towards Full Automation of the Lepton g −2 Calculation in QED
T. Aoyama, M. Hayakawa,∗1 T. Kinoshita,∗2 and M. Nio[QED, anomalous magnetic moment, muon, electron, automation]
The anomalous magnetic moments of leptons, calledg − 2, have been playing a central role in testing thevalidity of Quantum Electrodynamics (QED) and thestandard model. The electron g−2 was precisely measured by Harvard’s group in 2006. Their anomaly value
ae = (g − 2)/2 is1)
ae = 1 159 652 180.85(0.76) × 10−12 (0.66ppb). (1)This value has a 5.5 times smaller uncertainty than
University of Washington’s measurement in 1987.2)
The muon g−2 was measured at Brookhaven National
Laboratory and the ﬁnal results were announced in
2004.3) The average of the positive and negative muonsisaµ = 11 659 208(6) × 10−10(0.5ppm).

(2)

Theoretical calculations of g − 2 have achieved thematching precision of the measured anomaly values.
By now, the QED contributions up to the eighth order of perturbation theory are known.4,5) Using themeasured electron g−2 value in Eq. (1) and QED prediction,5) a new value of the ﬁne structure constant α
was determined:6)
α−1 = 137.035 999 710 (96)(0.70ppb),(3)

which is an order of magnitude better than other α’s.
Both Harvard and BNL plan to improve their measurements by a factor three and more. Consideringsuch a situation, we started evaluating the tenth-ordercontributions a few years ago. There are 12672 Feynman diagrams contributing to electron g −2 and 9080
to muon g−2. These numbers of diagrams are so hugeand very discouraging.
It turns out, however, that a good estimate for thetenth-order contribution to muon g−2 can be obtained
without performing gigantic calculations. The diagrams that give the leading contribution can be computed with the slightly modiﬁed computer programs
for lower-order ones. We directly calculated 2958 diagrams and obtained a new estimation of the coeﬃcientof (α/π)5 muon g−2:7)
A2 (mµ /me ) = 663 (20),(4)

which is a factor-of-8 improvement over the previous
estimation 930(170).8)
In contrast to muon g−2, none of the 12672 diagrams
dominates the electron g − 2. The most diﬃcult to∗1∗2

Present Address: Department of Physics, Nagoya University
Permanent Address: Laboratory for Elementary-Particle
Physics, Cornell University

evaluate are 6354 diagrams belonging to Set V, whichcontain no closed fermion loop. To carry out this hugecalculation without error, it is inevitable to automate
the whole process of computation.
The ﬁrst version of the automation code was completed in 2005.9) Given a one-line information of a diagram, this automatic code creates the following:(1) building blocks for the diagram,(2) g−2 amplitude,(3) ultraviolet renormalization terms,(4) outputs ready to go to numerical integration.
Among those in Set V, 2232 diagrams were generated with this version and were numerically evaluated.
The remaining 4122 diagrams suﬀer from infrared (IR)divergence. In the ﬁrst attempt, we treated IR divergence by giving a small ﬁctitious mass to the photon.
This IR cut-oﬀ method surely works for the lower-ordercases, but it seems diﬃcult to improve the numericalprecision of integration, particularly for the tenth order.
Therefore, we have further developed our automation code, which has just been completed. The newversion analyzes the IR structure of a given diagram
and automatically creates the IR subtraction terms. So
far, we have tested the new automation code for thesixth- and eighth-order cases. Both results are in good
agreement with known ones. We are now investigatingand evaluating the tenth-order diagrams on RIKEN’s
supercomputer system (RSCC). We expect to get theﬁnal result from Set V within several months.
References
1) B. Odom, D. Hanneke, B. D’Urso, and G. Gabrielse:
Phys. Rev. Lett. 97, 030801 (2006).
2) R. S. Van Dyck, Jr., P. B. Schwinberg, and H. G.
Dehmelt: Phys. Rev. Lett. 59, 26 (1987).
3) G.W. Bennett, et. al. (muon g−2 collaboration): Phys.
Rev. Lett. 92, 161802 (2004).
4) T. Kinoshita and M. Nio: Phys. Rev. D 70, 113001(2004).
5) T. Kinoshita and M. Nio: Phys. Rev. D 73, 013003(2006).
6) G. Gabrielse, D. Hanneke, T. Kinoshita, M. Nio, andB. Odom: Phys. Rev. Lett. 97, 030802 (2006).
7) T. Kinoshita and M. Nio: Phys. Rev. D 73, 053007(2006).
8) S. G. Karshenboim: Phys. Atom. Nucl. 56, 857 (1993).
9) T. Aoyama, M. Hayakawa, T. Kinoshita, and M. Nio:
Nucl. Phys. B 740, 138 (2006); Nucl. Phys. Proc.
Suppl. 157, 106 (2006); T. Kinoshita, T. Aoyama, M.
Hayakawa, and M. Nio: Nucl. Phys. Proc. Suppl. 160,
235 (2006).

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RIKEN Accel. Prog. Rep. 40 (2007)

Transverse double spin asymmetries in dimuon production at small
QT in pp and pp̄ collision
H. Kawamura, J. Kodaira,∗1 and K. Tanaka∗2[Transversity, Drell-Yan process, Soft gluon resummation]
The transversity δq(x), the distribution of transversly polarized quarks inside transversly polarized nucleon, is one of the fundamental quantities which describe the spin structure of nucleon. Tranversly polarized Drell-Yan (tDY) process: p↑ p↑↓ , p↑ p̄↑↓ → l + l̄ + X
is one of the processes where we can measure thetransversity. In fact, tDY is the simplest process toaccess δq(x) since it is inclusive for the ﬁnal state,
but whether it is actually useful to measure δq(x)or not depends on the magnitude of the asymmetry:
↑↑
−dσ↑↓
T dσ
≡ dσ
AT T ≡ ∆dσ
dσ↑↑ +dσ↑↓ . Unfortunately, AT T arelikely to be rather small at RHIC1) , because (i) pp collider probes antiquark’s distributions which is likely
to be small and (ii) the rapid growth of unpolarized
sea distributions suppresses AT T at low-x where tDY
at RHIC typically probes. On the other hand, muchlarger asymmetries are expected at the proposed spin
experiments at GSI, where polarized pp̄ collisions are
performed at lower energies2,3) . In this work, we study
the asymmetries in QT distribution of dimuon, especially at small QT where the bulk of dimuon is produced. Here we calculate the asymmetries in the crosssection which is diﬀerential in invariant mass Q, transverse momentum QT and rapidity y of dimuon, and in
the azimuthal angle φ of one of the outgoing leptons:∆T dσ/dQ2 dQ2T dydφ.
(1)
AT T =[dσ/dQ2 dQ2T dydφ]
The QT distribution of dimuon in tDY is calculated
in Ref.4) . At small QT , the resummation of large logarithmic corrections is crucial to make a reliable predictions. In Ref.4) , the resummation at the next-to
leading logarithmic (NLL) accuracy is carried out andcombined with the ﬁxed order result at the leading order (LO) in a consistent way. Using this “NLL+LO”
cross section of tDY and the corresponding one for unpolarized DY process, we calculate AT T in (1). As thenonperturbative input, we use a model of δq(x) whichsaturates the Soﬀer bound as δqi (x, µ20 ) = [qi (x, µ20 ) +∆qi (x, µ20 )]/2 at the low input scale µ0 ∼ 0.6GeV andis evolved to the higher µ2 with NLO DGLAP kernel5) . AT T in pp collision at RHIC kinematics areshown in Fig.1. In this case, AT T is about 4-8% andrather ﬂat in small QT region. We have smaller AT T
for smaller Q due to the suppression at small x. Comparing y = 0 and y = 2 cases, we obtain slightly larger∗1∗2

Theory Division, High Energy Accelerator Organization(KEK)
Department of Physics, Juntendo University

(%)

(%)

10

10

8

8

6

6

4
2
0
0

4

Q=3GeV
Q=5GeV
Q=8GeV
Q=15GeV1

0.5

Q=3GeV
Q=5GeV
Q=8GeV
Q=15GeV22
1.5
QT (GeV)

2.5

3

0
0

1

0.5

2
1.5
QT (GeV)

2.5

3√Fig. 1. AT T in pp collision at RHIC kinematics:
S =200GeV, Q = 3, 5, 8, 15GeV and φ = 0 with y = 0 (leftpanel) and y = 2 (right panel).

AT T for y = 2, but y dependence of AT T is small. On
the other hand, Fig.2 shows AT T in pp̄ collision at GSI
kinematics. Here the valence distributions of both incoming hadrons contribute, and large AT T of 15-30%
are obtained. Again the asymmetries become larger
as Q increases, and y dependence is very small. The
ﬂat shape of QT distribution at small QT is a common
feature of AT T , which shows the dominance of the soft
gluon efects, whichi is universal at NLL level in bothpolarized and unpolarized channels.
References
1) O. Martin, A. Schäfer, M. Stratmann and W. Vogelsang,
Phys. Rev. D57, 3084 (1998); ibid. D60, 117502 (1999).
2) H. Shimizu, G. Sterman, W. Vogelsang and H. Yokoya,
Phys. Rev. D71 114007 (2005);
3) V. Barone et al., Phys. Lett B639 483 (2006).
4) H. Kawamura, J. Kodaira, H. Shimizu and K. Tanaka,
Prog. Theor. Phys. 115, 667 (2006).
5) A. Hayashigaki, Y. Kanazawa and Y. Koike, Phys. Rev.
D56 7350 (1997); S. Kumano and M. Miyama, Phys.
Rev. D56 2504 (1997); W. Vogelsang, Phys. Rev. D57
1886 (1998).

(%)

(%)

40

40

30

30

20

20
Q=2GeV
Q=3GeV
Q=4GeV
Q=6GeV

10
0
0

0.5

1
QT (GeV)

Q=2GeV
Q=3GeV
Q=4GeV
Q=6GeV

10
1.5

2

0
0

0.5

1
QT (GeV)

1.5

2√Fig. 2. AT T in pp collision at GSI kinematics:
S =14.5GeV, Q = 2, 3, 4, 6GeV and φ = 0 with y = 0 (leftpanel) and y = 0.5 (right panel).

- 114 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Towards a global analysis of polarized parton densities
M. Stratmann[Perturbative QCD, spin structure of nucleons, theoretical uncertainties]
Extracting information about parton densities fromhadronic cross sections is an intricate problem, evenmore so if one is investigating the spin structure of nucleons. If applicable, the factorization theorem allows
us to study the non-perturbative hadronic spin structure, as parametrized by the polarized parton densities∆f , with the help of perturbatively calculable partonic
hard-scattering cross sections d∆σ̂. To quantify theoretical uncertainties, knowledge of the next-to-leading
order (NLO) QCD corrections is essential.
The relevant numerical expressions are often too
time-consuming to be of direct use in a “global analysis”, which usually requires thousands of evaluations of
the cross section for any given data point to determine
the set of parameters used to describe the parton distributions ∆f (x, µ0 ) at some initial momentum scaleµ0 . Therefore the prospects of learning from data depend on our ability to efficiently and reliably evaluate,
e.g., the cross section for pp → πXXd∆σ =∆fa ⊗ ∆fb ⊗ d∆σ̂ab→cX ⊗ Dcπ(1)

The complications in pinning down ∆g from pp data
are exemplified further in Fig. 1.1) Here we study therange of momentum fractions x predominantly probed
in pp → πX at RHIC energies for different assumptions
about the first moment of ∆g(µ0 ). While gluon-gluon
initiated subprocesses give a positive contribution tod∆σ, the sign of quark-gluon channels is correlatedwith the unknown sign and size of ∆g. Since bothcontributions peak at significantly different values ofx, the non-local x-distributions are readily explained.
π

ALL

∆g=g

NLO
0.05

∆g=0.7∆g=0.6∆g=0.45∆g=0.3
GRSV
∆g=-g
∆g=0

0

∆g=-1.05

abc

at NLO with ⊗ denoting a convolution. Simple approximations of (1), e.g., the assumption that NLO
corrections drop out in experimentally relevant spin
asymmetries, ALL ≡ d∆σ/dσ, or the use of some average momentum fraction hxi to get rid of the convolutions in (1), have been shown to be notoriously
unreliable for most processes in polarized pp and lp
collisions, see, e.g.,1,2) . In general, without knowing
the polarized parton densities, in particular the elusive ∆g, it is virtually impossible to assess theoreticaluncertainties and the relevance of NLO corrections.
pp → πXd∆σ / dpT dlog10x

40000∆g(µ)=1.24
30000

x≈0.03÷
0.16

20000

∆g(µ)=0.24∆g(µ)=0.60

10000

x≈0.03÷
0.19

7500
5000

10000
0

pT = 2.5 GeV

3000
x≈0.04÷0.23

2000
1000

2500
-2

-1 log x
100-2-1 log x
102000∆g(µ)=0400

x≈0.04÷
0.27

0

1500

∆g(µ)=-0.45

20000∆g(µ)=-1.24

1000

x≈0.008÷
0.08

15000

x≈0.03÷
0.13

500

10000

0

5000

0

-500

-1 log x
10-1 log x
10

0

2

4

6

8

10

pT [GeV]Fig. 2. PHENIX data for ALL compared to NLO analyses.

Since these complications are most relevant for realistic, moderate gluon polarizations the goal must be
to circumvent all approximations. This can be accomplished by transforming (1) into complex Mellin moment space.3) This allows to store all time-consuming
integrations in (1) in large grids prior to the global
analysis. The growing amount of data from RHIC has
put this technique to the test.4) Figure 2 compares
NLO calculations based on different constraints on thefirst moment of ∆g with recent Phenix data on ALL .
∆g’s with a large and positive first moment are clearly
disfavored. Upcoming data will further close in on ∆gand will eventually clarify its role in the spin sum rule.

25000

200

-2

-2

PHENIX run 5 (prel.)-2-1 log x
10

0

-2

-1

Referenceslog10xFig. 1. The shaded areas denote the x-range dominantly
contributing to d∆σ for different values of ∆g(µ0 ).

1) M. Stratmann, contribution to the proceedings of “DIS2006”, Tsukuba, Japan, World Scientific (to appear).
2) B. Jäger, M. Stratmann, W. Vogelsang, Phys. Rev. D
67, 054005 (2003); ibid. D 68, 114018 (2003); ibid. D
70, 034010 (2004); Eur. Phys. J. C 44, 533 (2005).
3) M. Stratmann and W. Vogelsang, Phys. Rev. D64,
114007 (2001).
4) M. Stratmann and W. Vogelsang, work in progress.

- 115 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Productio n of U beam fro m RIK EN 18G Hz ECRIS
Y. Higurashi, T. Nakagawa, M. Kidera, H. Haba, T. Aihara*, M. Kase, A. Goto and Y. Yano

One of the requirements of the RIKEN RI beam factory(RIBF) project is production of U ion beams1). We,
therefore, study how to produce the U ion beams. Here, wereport the detailed experimental procedure and results ofexperiments using UF6 and sputtering method.
We used UF6 for the production of U ion beams from the
ECR ion source. When using UF6, it does not require anoven nor an insertion system for solid rods to be vaporizedunder plasma sputtering. It is possible to produce U ions inthe same manner as in the case of gaseous elements. Figure
1 show a cross-sectional view of the RIKEN 18GHz ECRIS
and a schematic drawing of a UF6 bottle. Details of thedescription of the RIKEN 18GHz ECRIS and its
performance are described in ref. 2. The UF6 bottle (50 cm3
in volume) was connected to a gas-feeding tube via a
variable slow-leak valve to control the flow rate of UF6
vapor. About 10 g of UF6 was filled in the UF6 bottle. No
gas-mixing method was applied in these present
experiments. To minimize contamination, the plasmachamber wall was covered with a thin aluminum tube (of 1mm thickness), which is easily replaceable. Furthermore,
the aluminum surface emits several secondary electrons per
primary electron impact, which increases the plasma
density.3)

Fig. 1. Cross-sectional view of RIKEN 18 GHz ECRIS andschematic drawing of UF6 bottle..
Figure 2 shows the charge state distribution of U ions.
The ion source was tuned for production of the U14+ ions.
The injected microwave power was 60 W. The gaspressures of the plasma chamber and extraction stages were
4.3×10-7 and 4.0×10-8 Torr, respectively. The extraction
voltage was 14.1 kV. Using this method, we successfully
produced an intense beam of U14+ ions (~1.5 pµA)
continuously for 6 days for RIBF commissioning.
A U35+ ion beam is required from an ion source, unless we
use the first charge stripper. To produce U35+ ions, we used
the sputtering method. First, we measured the䟼Fig. 2. Charge state distribution of U ions. The ion source
was tuned for the production of U14+ ions.
beam intensity of U ions from a metal uranium rod. The
size of the rod was 6×3×25 mm. To check the effect ofionized gas (base gas for production of plasma) on beamstability and intensity, we chose N2, O2, and Ne gases as
ionized gases. In this experiment, the beam intensity of U
ions using O2 gas is more stable than that using N2, or Ne
gas. However, the beam intensity of U ions produced using
Ne gas is higher than that using N2 or O2 gas, because thesputtering effect of Ne ions is much better than that of N or
O ions. Figure 3 shows the charge state distribution of Uions. The ion source was tuned for the production of U35+
ions. The ionized gas was O2, the injected microwave
power was 500 W, the sputtering voltage was 1.9 kV, thegas pressure was 1.0*10-6 Torr, and the extraction voltage
was 12.7 kV. Using this method, we successfully produced
a beam of U35+ ions (~0.06 pµA) for 24 hours.

Fig. 3. Charge state distribution of U ions. The ion source
was tuned for the production of U35+ ions.
References1) Y. Yano: Proc. 17th Int. Conf. on Cyclotrons and Their
Applications. (Tokyo, JAPAN, 2004), p. 169.
2)T. Nakagawa, Y. Higurashi, M. Kidera, T. Aihara, M. Kase andY. Yano: Nucl. Instrum. Methods Phys. Res. Sect. B 226 (2004)
392.
3) Nakagawa, T. Kurita, M. Kidera, M. Imanaka, Y. Higurashi,
M.Tsukada, S. M. Lee, M. Kase and Y. Yano: Rev. Sci.
Instrum. 73(2002) 513.

SHI Accelerator Service, Ltd- 117 -

RIKEN Accel. Prog. Rep. 40 (2007)

Design of superconducting magnet system for RIKEN 28 GHz SC-ECR ion source
T. Nakagawa, J. Ohnishi, M. Kidera, Y. Higurashi, H. Saito and A. Goto
To meet the required beam intensity of heavy ions
(1 particle µA on target) for the RIKEN RI beam factory
project1), we constructed several high performance 18 GHz
ECR ion sources2,3). However, to achieve a 1 particle µA U
ion beam at 350 MeV/u, U35+ ion beam with the intensity
higher than 15 particle µA is required from an ion source,
unless we use a first charge stripper.1) To produce such an
intense beam of U35+ ions, we have to use a high magnetic
mirror ratio and a high microwave frequency ( > 18 GHz) toincrease plasma density and ion confinement time. For thisreason, we plan to construct a new RIKEN Superconducting
ECR ion source that has an operational frequency of 28
GHz.4)

magnetic field strength including the axial field. The
hexpole coils have iron poles with a length of 300 mm toincresae the magnetic field at the central region. The
hexapole field of 2.1 T at maximum can be produced.

Fig.3. Magnetic field strength on inner wall of plasmachamber (radius of 75 mm).

Fig.1. Arrangement of superconducting coil assembly.
Figure 1 shows the arrangement of thesuperconducting coil assembly developed. The coils arecomposed of six solenoid coils (SL1 ~ SL6) and one
hexapole coil (HX).
Figure 2 shows the mirror magnetic field strength on
axis. Magnetic fields strength was calculated using 3d-code“TOSCA”. The peak fields at the RF injection and the beam
extraction sides are 4 T and 2 T, respectively. The minimum
magnetic field can be changed from 0 T to 1 T. Foursolenoid coils (SL2~ SL5) work to produce a flat magnetic
field in the central region for increasing the size of ECR
surface.

The coil dimensions and parameters are shown in Table
1. The inside radii of the hexapole and solenoid coils are
102 mm and 170 mm, respectively. The maximum fieldstrengths in the coils for the solenoids and hexapole coils
are 7.5 T and 6.9 T, respectively. The magnetic stored
energy is 830 kJ with all coils at the design current.

Fig.4. Cross-sectional view of cryostat.
Fig.2. Mirror magnetic field strength on axis.
Figure 3 shows the magnetic field distributions on thesurface of the plasma chamber with an inside radius of 75
mm. The curve ‘By’ indicates the magnetic field producedby the hexapole coil and the curve ‘B’ indicates the

Figure 4 shows a cross-sectional view of a cryostat. The
superconducting solenoid and hexapole coils are located ina liquid-He vessel. The amount of liquidHe in the vessel isassumed to be ~500 L. The cryostat is equipped with two
small refrigerators for 4 K and 70 K stages and operated- 118 -

RIKEN Accel. Prog. Rep. 40 (2007)

without adding liquid-He after the initial pour. The heatload to 4 Kstage is estimated to be 6 W, which includes 3
W due to the estimated X-ray irradiation from the plasma.
Nine current leads made of high temperature
superconducting material are used to reduce the heat load at
4 K stage. The estimated heat load at 70 K stage is 160 W
owing to copper current leads, supports of a cold mass andradiation throughout the multi-layer insulation. A magnetic
shield with a 50 mm thickiron yoke surrounds the cryostat.

supplies. The solenoid coils are excited with seven hightemperature superconducting current leads. The current
leads between two adjacent solenoids is used to reduce theheat load. When a quench happens to any coil, all power
supplies are disconnected from the coils and the stored
energy is discharged to the dump resistors. The resistances
are 1 ohm for SL1, SL6 and HX, and 0.2 ohm for the others.
The dump resistors and diodes are placed in the liquid-He
vessel to protect the coils when any of the high-Tc current
lead breaks.
References
1) Y. Yano: Proc. of 17th Int. Conf. on Cyclotrons and theirapplications p. 169.
2)T. Nakagawa et al. : Nucl. Instrum. Methods
B226,392(2004).
3)T. Nakagawa et al. : Rev. Sci. Instrum. 75, 1394 (2004).
4)T. Nakagawa and Y. Yano: Nucl. Instrum. Methods B241,
935 (2005).

Fig.5. Diagram of electric circuit of superconducting coils.
The maximum electromagnetic force between themagnetic shields and the cold mass is estimated to be 8 tons
in the axial direction. The cold mass is supported withGFRP belts from an outer tank at room temperature.
Figure 5 shows a connection diagram of the electric circuitof the superconducting coils. The six solenoids and thehexapole coils are excited individually with seven power

Table 1. Coil dimension and parameters- 119 -

RIKEN Accel. Prog. Rep. 40 (2007)

Control Syste m for RIKE N Accelerator Research Facility and
RIKEN R I-Be am Fac tory
Misaki Kobayashi-Komiyama, Masaki Fujimaki, Akito Uchiyama *1, Makoto Nagase and Masayuki Kase
The control system of the RIKEN RI-Beam Factory(RIBF) is based on the control system of the RIKEN
Accelerator Research Facility (RARF), which is constructedusing EPICS1). We expanded a console at the control roomin the Nishina building for RIBF control and have started
the beam commissioning of RIBF since July. The latest
improvements of the system are indicated in this paper.
Figure 1 shows groups of accelerators and their interface
devices in the RARF and RIBF control system. Except
stand-alone systems, such as a system for an ion source or
rf, most parts are controlled using EPICS. We control
GP-IB devices using EPICS device support programs
supported by EPICS collaboration. On the other hand, NIO,
CC/NET, DIM, N-DIM and PLC are controlled using
device support programs developed by ourselves originally.
In particular, device support programs for CC/NET, N-DIM
and PLC were developed with the control group of KEK;
thus, we use the same programs among RIKEN, KEK and
J-PARC control systems2).
Table 1 shows the current number of interface devices
used in the RARF and RIBF control system. It includes thenumber of devices from RILAC to SRC, excluding an
injection beamline for Big-RIPS.

Table 1. Current number of interface devices
DIM (PS)80
DIM (BD)
100
GP-IB (GMACS)
4
GP-IB (IDX)
5
NIO-S
420
N-DIM (PF)90
N-DIM (RP)12
N-DIM (FC)60
N-DIM (VAC)70
PLC (Omron)
2
PLC (Melsec)
2
PLC (FA-M3)
3
Figure 2 shows the structure of RARF and RIBF control
system. A file server based on an HP-UX system and Force
VME computers placed in the Nishina building are theoldest devices in our system. We introduced the file serverin 2001 and the VME computers in 1999. Except RILAC,
most power supplies and beam diagnostic devices
composing RARF are still controlled using these computers.
Furthermore, many application programs, including GUI,graphic formulas and data taking also run on the file server.

RARF
RILAC
Ion Source
RF

RIBF

AVF/RRC

Hard wire/WE 7000

WE 7000

PLC (CVM1)

PLC(Melsec)
/DIM

BT

BT
(in RIBF)

PLC (CS1)

Magnet Power Supply GP-IB/NIO/DIM

DIM

DIM/NIO

Beam Diagnostics

DIM

DIM/N-DIM

BT(in Nishina)fRC

DIM/NIO

NIO/DIMNIO

DIM/N-DIM

N-DIM/DIM

N-DIM

N-DIM

Driving Controller

DIM

DIM

DIM

PLC (FA-M3)/N-DIM/DIM

VacuumN-DIM

PLC (CS1)

DIM/N-DIM

PLC(FA-M3)

Beam Interlock

Hard wire/PLC (Melsec)

DIM

DIM

Cooling

Local Control

Local Control

Local Control

N-DIM

Injection Linefor Big-RIPS

Big-RIPS

NIO

NIO

NIO

N-DIM

N-DIM

PLC(FA-M3)

IRC

SRC

PLC (CS1)

PLC (CS1)

NIO
N-DIM

N-DIM

PLC (CS1) PLC (Melsec)/N-DIM/N-DIM

N-DIM

PLC (CS1) PLC (Melsec)

PLC(FA-M3)
N-DIM

PLC (Melsec)
Local Control

Local Control: controlled by existing EPICS system

PLC (Melsec)* NIO: Network-I/O (NDS): monitored by existing EPICS system: will be controlled by expanded existing EPICS system: will be monitored by existing EPICS system

Fig.1. Interface devices used in RARF and RIBF control system*1 SHI Accelerator Service, Ltd.

- 120 -

PLC(FA-M3)

RIKEN Accel. Prog. Rep. 40 (2007)

The file server had functioned very stably; however, avery serious accident on two disks after the summer
maintenance of RARF occurred. We changed the two disks
and recovered the programs hardly. Now, we are attempting
at replacing the system with another system because of its
age and high-cost maintenance. There are seven CAMAC
crates in the RARF control system, and we have alreadyreplaced two of these crates with a network crate controller,
CC/NET, which is manufactured by TOYO Corporation.
We have a plan to replace the remaining five crates next
year. Furthermore, we are attempting at implementing theapplication programs on the HP-UX server to the Linuxserver. After successfully implementing the programs, wewill remove the HP-UX server and the Force VME
computers from the control system.
For replacing the system of the HP-UX server and theForce VME computers, we introduced two types of system,
namely, a system consisting of the Linux server andMotorola VME computers, and a Linux PC system, whichfunctions as both an operator interface and an I/O controller(IOC). The former controls magnet power supplies (NIO).
Although we mounted an upgraded EPICS base on theformer, almost all current and device support programs canbe used in the new system with a small change. The later
mainly controls beam diagnostic devices and vacuum
systems. Following the rearrangement of the EPICS control
network system last summer, we set up one Linux PC toeach subnet and each building. Although we introduced
them step by step and there are some versions of Linuxkernel, EPICS base and device support program, the entire
system ran smoothly. However, it will be difficult to
support many independent IOCs in the future; thus, we are
now rearranging the Linux IOC system. To achieve a highperformance, a high stability and a high security, we aregoing to introduce new file servers and small single board
computers for IOCs. To share common programs with all
IOCs, each board computer requires to obtain necessary
files from the file server by NFS to run as an IOC, forexample, EPICS base, device supports and runtime database.
We have already constructed a test system using a PC as afile server and a wireless router application platform(WRAP) 3) as an IOC. To date, it has functioned wellwithout any serious troubles. We will replace a PC for aserver machine with a RAID system as soon as possible.

Fig.2. Structure of RARF and RIBF control system
References
1) http://www.aps.anl.gov/epics/2) J. Odagiri et al.: Proc. 3 Annu. Meet. Particle Accelerator
Society of Japan and 31 Linear Accelerator Meet. in Japan, Sendai,
2006-8 (2006).
3) http://www.pcengines.ch/- 121 -

RIKEN Accel. Prog. Rep. 40 (2007)

Development of Beam Phase Measurement Systemusing Lock-In Amplifier for RARF/RIBF
R. Koyama,∗1 M. Kase, T. Watanabe, M. Fujimaki, Y. Kotaka,∗1 N. Fukunishi, and Y. Yano
In conventional tuning for an isochronous magnetic
field of cyclotrons, we have used an oscilloscope toobserve the beam bunch signal from the phase probe(PP). However, when the beam current is small, it isdifficult to observe the beam bunch signal with an oscilloscope because rf and its higher harmonics from cyclotron cavities are superimposed on the signal. Thereis also a disadvantage in that we cannot obtain tuning
results for an isochronous field as quantitative data inthis method. Hence, we have developed a new measuring system using a lock-in amplifier (LIA) for beamphase measurement. Our final goal is to apply this system to a tuning procedure for an isochronous magnetic
field of the cyclotrons of RARF/RIBF.
LIAs are used to detect and measure very small AC
signals — as small as a few nanovolts. LIAs are usedwith a technique called phase-sensitive detection to single out the specific frequency component. Noise signals
such as an rf signal and its higher harmonics from cavities at frequencies other than the reference frequency
of LIAs are neglected and do not affect the measurement. We have adopted the SR844 RF lock-in amplifier1) manufactured by Stanford Research Systems.
Its main specifications are listed in Table 1. The functional block diagram of the SR844 is shown in Fig. 1.
The block diagram for signal capturing using theSR844 is shown in Fig. 2. In our system, the accelerating rf signal from a signal generator (SG) and the beam
bunch signal from PP is used as the reference and the
input signals of the SR844 system, respectively. The
higher harmonics of the SG was also used as the reference signal of the SR844 depending on the S/N ratio.
Using these signals, we can obtain in-phase (I) and
quadrature (Q) components of the beam phase withreference to SG.
We have built a LabVIEW2) program to control theSR844 system and to obtain data continuously via the
GPIB interface (GPIB-USB-HS). The program also
provides the phase and amplitude of the beam bunch
signal from the measured IQ components, and plotsthem on the LabVIEW front panel (Fig. 3).
Thus far, we have carried out several test measurements using the SR844 system (Fig. 2) for RILAC,
AVF, and RRC. The tuning results for the isochronous
field are compared with those obtained by the conventional method using an oscilloscope for AVF and RRC.
A good agreement of results were obtained.
Recently, we have commissioned the use of the fRC3)
with 10.75 MeV/u 238 U73+ beam preaccelerated by RILAC and RRC. The injection beam current was about∗1

SHI Accelerator Service, Ltd.

Table 1. Main specifications of the SR844 system.
Signal Channel:
Input impedance
50 Ω or 1 MΩ + 30 pF
Damage threshold ±5 V (DC + AC)
Bandwidth
25 kHz to 200 MHz
Dynamic reserve
up to 80 dB
External Reference:
Input impedance
50 Ω or 10 kΩ + 40 pF
Input level
0.7 Vpp pulse or 0 dBm sine
Demodulator:
Time constants
100 µs to 30 ks with 6, 12, 18
or 24 dB/octave rolloff”No-Filter” mode
10 to 20 µs update rate
Displays:
Channel 1
I, R, I-noise, or AUX In 1
Channel 2Q, θ, Q-noise, or AUX In 2
Reference
Freq., phase, offsets, AUX out,
IF freq., or elapsed time
Channel 1 and 2 Outputs:
Voltage range± 10 V full scale proportional toI, Q or Ch.1, 2 displayed quantity
Update rate
I, Q
48 to 96 kHzR, θ, AUX inputs
12 to 24 kHz
I-noise, Q-noise
512 HzGeneral:Interfaces
IEEE-488.2 and RS-232 interfaces

Fig. 1. Functional block diagram of the SR844 system.

100 enA. In the commissioning, we had no choice but to
use the SR844 system for the tuning of the isochronous
field, because currently, the 238 U73+ injection beam
current of fRC is too small to observe the beam bunch- 122 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 2. Block diagram for signal capturing using the SR844
system.

Fig. 3. Screen capture of the front panel of the built LabVIEW program.

signal by the conventional method using an oscilloscope.
The fRC sector magnet has one main coil and 10
trim coils for the tuning of the isochronous magnetic
field. The electric current of these coils are variable individually. The 14 PPs are installed in the valley box
of fRC. Each PP consists of a pair of parallel plate pickups with a gap of 30 mm. The PP measures the beamphase by timing the beam bunch passing through the
pick-ups. The time required to pass through the beam
bunch at each PP changes when the electric current ofeach trim coil is slightly changed and can be evaluatedby the orbital calculation within a first-order approximation. On the basis of this calculation, a χ2 fitting is
performed as the fluctuation of the phase distribution
at all PPs measured by SR844 system becomes minimum. From the fitting, the electric current of eachtrim coil that makes the isochronous magnetic fieldcloser to the ideal one is evaluated. The appearance inwhich the isochronous field is iteratively made by thismethod is shown in Fig. 4. As the result of five iterations, the obtained standard deviation of the phase
distribution for all 14 PPs was 0.13 nsec. This value iscomparable to the tuning results for RRC obtained by
the conventional method using an oscilloscope. Fromthese results, our SR844 system was found feasible for2- 123 -

Fig. 4. SR844 phase output for each PP of fRC. The injection beam was 10.75 MeV/u 238 U73+ and its beam current was about 100 enA. The appearance in which theisochronous magnetic field is iteratively made is shown.

the tuning of the isochronous magnetic field with asmall beam current.
The commissioning of the IRC is currently inprogress and the SR844 system works basically well.
However, because large fluctuations of the noise levelhas been observed, we are presently modifying the LabVIEW program to solve this problem. We will also
soon have the commissioning of the SRC following the
IRC and use the SR844 system for the tuning of theisochronous magnetic field.
We have to address the following issues to makeour system applicable to the tuning of the isochronous
magnetic field of RARF/RIBF cyclotrons:(1) Search reference frequencies, harmonics of thebeam frequency, which is nearly undisturbed byaccelerating rf and its higher harmonics for each
cyclotron of RARF/RIBF.
(2) Make efforts to reduce noise level on the beam
bunch signal such as rf and its higher harmonics
from cavities of cyclotrons.
(3) Evaluate systematic errors of the measurement.
(4) Modify further the LabVIEW program (e.g. responds to noise fluctuation and communication
with N-DIM4) .).
Finally, the authors are grateful to the operation
crews of SHI Accelerator Service Ltd. for their cooperation with the measurements using the SR844 system.
References
1)

Users Manual; Model SR844 RF Lock-In Amplifier ,Revision 2.6, Stanford Research Systems Inc., (2003).
2) <http://www.ni.com/labview/>, National Instruments
Corp., (6th November 2006, Last accessed).
3) N. Inabe et al.: Proc. 17th Int. Conf. on Cyclotrons
and Their Applications, Tokyo, 2004-10 (Japan Particle
Accelerator Physics Society, 2005), p. 200.
4) M. Fujimaki et al.: RIKEN Accel. Prog. Rep. 38, 258(2004).

RIKEN Accel. Prog. Rep. 40 (2007)

Study of New Flat-Top Resonator for RRC
L. Stingelin, A. Goto, O. Kamigaito, N. Sakamoto, and Y. Yano
Our study of the flat-top resonator1,2) for the
RIKEN Ring Cyclotron (RRC) has been advanced inthree points:(1) The thermomechanical design was discussedwith the industry partner Sumitomo Heavy Industries.
(2) The rf-model was refined using ANSYS’3) threedimensional electromagnetic eigenmode solver.
Coupling and fine-tuning methods were investigated.
(3) Beam dynamics simulations were performed toanalyze the effect of the flat-top resonator on
beam quality.

Fig. 2. Side view of Dee, electrodes and stems. The power
density is shown for operation at maximum frequency.

It is expected that the flat-top resonator will minimize
the energy spread of particle bunches and hence the extraction losses of the RRC. Therefore, it might help in
the future to increase the beam intensity of the RIKEN
RI Beam Factory (RIBF).
SM SOUTH
Extr.
Beam

Gap 2
Gap 1

EBM2

Fig. 3. The current density of the shorting plate is shownfor operation at maximum frequency.

Dee
CC FT

BM1

PP
SM EAST
EBM1

Last TurnFirst Turn

Fig. 1. Top view of proposed valley box with flat-top resonator: phase probe (PP), capacitive coupler (CC), finetuner (FT), injection- and extraction-bending magnets(BM1, EBM1, EBM2) and sector magnet (SM).

The flat-top will be achieved by a third-harmonicresonator with a frequency range of 54-120 MHz anda total peak gap voltage of approximately 135 kV. It
was possible to find an rf-geometry for the flat-top resonator that might fit into the RRC and allows reliable operation. Figure 2 and 3 show the power density and current density of the proposed flat-top resonator. The highest current density in the shorting
plate of 23 A/cm was found at an operation frequencyof 113 MHz and the maximum electric field in the resonator of 3.7 MV/m at a frequency of 90 MHz. The
maximum power requirement is about 15 kW1) .
As indicated in Fig. 1, the injection- and extractionbending magnets (BM1 and EBM2) prevent the useof the standard capacitive coupling and tuning methods at the shorter resonator walls. However, simulations with ANSYS’ eigenmode solver4) predicted thatcapacitive power coupling could be achieved even if
the coupler is located at the larger sidewall of the resonator (see Fig. 1). Compared with an inductive coupling loop located near one of the shorting plates, thisdesign has the advantage of easier manufacturing andmaintenance because less movable parts are used.
For the analysis of the effect of the flat-top resonatoron the ion beam quality, the focusing properties of thesector magnets had to be known. Because the measured field map data were no longer available, the magnetic field had to be calculated from scratch. ANSYS’magnetostatic solver with hexahedral mesh (ANSYS
element types SOLID96, SOURC36 and INFIN111 )was used for this simulation. For the accurate representation of the sector magnet geometry, fine stairs(B-constant profile) and steps (Purcell gap and shims)
had to be taken into account. This made the meshgeneration very challenging; however, it was possible
to create a mesh with a total of about 717,000 elements
and 679,000 nodes. A comparison with the measured
field on the center line showed a difference of less than
0.5%.
The beam dynamics program5) was written in
C/C++. A fourth-order Runge-Kutta algorithm withthird-order interpolation of the magnetic fields waschosen for particle tracking and MayaVi 6) and PyLab 7)- 124 1

RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 4. Graphical output of beam dynamics program for
10.7M eV /u 238 U 35+ acceleration with flat-top resonator. Schematic top view of RRC in small picture.
The charge distributions for the last two turns areshown in the magnified rectangle.

were used for the visualization of the simulation data.
Figure 4 shows the charge distributions at the last
two turns for flat-top acceleration. The injected beam
had a phase width of about ±8.58◦ and the energy
spread was about ±0.187%. These parameters are actually expected to be near the injection conditions currently used. The rf-frequency is 18.25 M Hz in themain resonators and 54.75 M Hz in the flat-top resonator. Since the gap-voltage distributions are almost
constant at these frequencies, only a small phase compression can be observed. At extraction, the beamreached a phase width of about ±7.29◦ and an energy spread of ±0.017%. It can be observed that thebunches are clearly separated at extraction.
The extraction losses of the RRC could also be reduced for conventional acceleration, if the injection
beamline between RILAC and RRC is improved. A
stronger bunching of the beam could then lead to a
reduction of the energy spread at the extraction location. For example, a shorter phase width of about±2.87◦ at the RRC injection location could first lead toan increased initial energy spread of about ±0.560%,
if the longitudinal emittance is conserved. However,the shorter phase width would finally result in a reduced growth of the absolute energy spread during theacceleration in the RRC. Figure 5 shows the calculated charge distributions at the last two turns for thiscase. At extraction, the beam reached a phase width ofabout ±2.40◦ and an energy spread of ±0.080%. Compared with the case of flat-top acceleration shown in2- 125 -

Fig. 5. Case of 10.7M eV /u 238 U 35+ acceleration without
flat-top resonator.

Fig. 4, the bunches are slighly bent to a banana shapeand the trajectories of the ions are almost overlappingat the extraction location.
It can be concluded that extraction efficiency will
be higher for flat-top acceleration. The installationof a flat-top resonator therefore seems promising forthe acceleration of higher intensity beams in the RRC.
As discussed above, the injected bunches must havea smaller energy spread (at larger phase width) thanthat for conventional acceleration for optimal extraction conditions.
On the other hand, it should also be considered thatthe extracted beam must satisfy the matching condition for injection into the fRC8) and IRC.
This work was supported by the Japanese Society
for the Promotion of Science in the form of a postdoctoral fellowship. The RIKEN Computing Center isalso gratefully acknowledged for providing the necessary simulation resources.
References
1) L. Stingelin et al.: RIKEN Accel. Prog. Rep. 39, 237(2006).
2) L. Stingelin et al.: Proc. 3rd Annu. Meet. Particle Accelerator Soc. Jpn. and 31st Linear Accelerator Meet.
Jpn., Sendai, 2006-8 (2006).
3) http://www.ANSYS.com
4) P. Balleyguier: Part. Accelerators 34, 113 (1997).
5) L. Stingelin: Thesis No. 3169, Swiss Federal Institute ofTechnology Lausanne (2005).
6) http://mayavi.sourceforge.net7) http://matplotlib.sourceforge.net
8) T. Aoki et al.: RIKEN Accel. Prog. Rep. 39, 246 (2006).

RIKEN40 (2007)RIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 40(2007)

Construction of Rebuncher for fRC
T. Aoki,∗1 L. Stingelin, O. Kamigaito, N. Sakamoto, N. Fukunishi, S. Yokouchi, T. Maie, M. Kase, and A. Goto
A rebuncher between the RIKEN Ring Cyclotron(RRC) and the Fixed-frequency Ring Cyclotron (fRC)
has been constructed. It is now used for the commissioning of fRC. In the future, it will be used for reducing the phase width of the beam injected to fRC.
In this report, design studies of the resonator and test
results are described.
The rebuncher resonator is based on a new type of
H-mode structure1) , as illustrated in Fig. 1. An advantage of this structure is that the intergap voltages
are almost equal to each other, which is difficult to realize in conventional Interdigital-H (IH) and Crossedbar-H (CH) structures. In addition, we can make alarge pumping port in the lower part of the resonatorwithout increasing the rf-power losses, because the rfmagnetic field is very weak in that part.2)

Fig. 1. Schematic drawing of rebuncher resonator and detailed structure of drift tubes.

The detailed study of the rf-field was started using the MAFIA code.3) The cell length was set tobe 208 mm, which is 1/12 of the beam-bunch separation, with a gap length of 104 mm. A cylindricaltuner of 120 mm diameter is placed in the upper halfof the resonator for tuning the frequency in the rangeof ±390 kHz. The rf-power is fed through an inductive
coupler that could be rotated for matching the input
impedance. The edges of the drift tubes have beenrounded as shown in Fig. 2, to keep the surface electricfield less than 8.0 MV/m at maximum gap voltage of
150 kV. The maximum surface current was simulated
to be 29 A/cm at the roots of the horizontal stem.
It is known that the MAFIA code sometimes gives
lower resonant frequencies particularly when the number of mesh points is not sufficient in the simulations. We observed that the frequency was increased∗1

Department of Physics, School of Science, The Graduate
University of Tokyo, Japan

Fig. 2. Detailed geometry of drift tube.

Table 1. MAFIA simulations and measured results for initial shape of stem shown in Fig. 1.

MAFIA
Measurementf [MHz]Q0

109.65110.01

2.4 × 104
1.9 × 104

by 0.2 % when we changed the number mesh points
from 1.4 × 106 to 4.0 × 106 . Therefore, we made theupper stem (indicated by ”A” in Fig. 1) slightly wider
than that giving the desired frequency of 109.5 MHz.
This width has been adjusted to give the desired frequency after the fabrication, as mentioned below. The
simulated frequency and unloaded Q-value are listed
in Table 1.
The resonator was fabricated by Sumitomo Heavy
Industries, Niihama Works. The inner electrodes suchas the drift tubes and stems were made of oxygenfree copper (C1020), whereas the outer wall was madeof steel (SS400) plated with 30-75 µm copper. The
resonator is equipped with a turbomolecular pump of1100 l/s for normal operation and a rotary pump of
20 m3 /h for initial evacuation. The designed vacuum
level is 2.7 × 10−5 Pa. The required water flow is
35 l/min at a pressure loss of 0.38 MPa.
After the fabrication, the resonant frequency and Qvalue were first measured. As shown in Table 1, themeasured frequency was slightly higher than the calculated value. We have decided to cut both sides ofthe stem by 17 mm, as shown in Fig. 3, because the
MAFIA code predicted that the frequency would decrease by 965 kHz by this modification. The computercode ANSYS4) , which is known to give a better prediction, also supported this decision.
After this modification, the desired frequency of
109.5 MHz has been achieved. The measured frequencies of the fundamental and higher modes are listed
in Table 2, as well as the ANSYS results for the final
configuration. As shown in Table 2, the measured frequencies are in very good agreement with the ANSYS- 126 1

RIKEN Accel. Prog. Rep. 40 (2007)

denote the voltage at the two outer gaps and the voltage of two center gaps, respectively. This value is ingood agreement with the simulation result.
We also deduced the shunt impedance Rs of the resonator, which is defined by
2

Rs =Fig. 3. Final shape of stem. Both sides have been cut by
17 mm.
Table 2. Measured results and simulations by ANSYS for
final shape of stem shown in Fig. 3.
Measurement
Mode
(1)
(2)
(3)
(4)
(5)
(6)
(7)

f [MHz]109.50149.49172.88244.86264.28298.86358.26

ANSYS

Q0
4

1.8 × 102.0 × 104
2.1 × 104
4.4 × 104
4.5 × 104
3.2 × 104
6.8 × 104f [MHz]Q0

109.52150.21172.76245.37264.69299.71358.62

2.3 × 104
2.7 × 104
2.2 × 104
5.2 × 104
5.2 × 104
3.6 × 104
6.8 × 104

results with deviations less than 0.5 %.
As for the second step of the low power test, thedistribution of the electric field strength was measured
on the beam axis by the perturbation method5) using
Teflon balls with radii of 8 and 5 mm. The measured
results are shown in Fig. 4, along with the calculations
by MAFIA and ANSYS. The calculated results given
are scaled so that the integral of the field strength (|E|)
might become equal to that of the results of measurement. As shown in Fig. 4, the ANSYS code gives abetter prediction for the measured data; the maximum
deviation is less than 5 %.

[2 (V1 + V2 )].
2P

The measured shunt impedance reached 26.1 MΩ. The
ratio of the measured Rs to the calculated Rs and thatof the measured Q0 to the calculated Q0 are very similar.
The high-power test was started just after installation in the beamline in June 2006 (see Fig. 5). The
rf-power was fed with a solid-state amplifier of 5 kW
maximum output power. Although multipactoring effects were observed at the total voltage (2 [V1 + V2 ])range of 200-300 kV, we could achieve the maximum
voltage of 470 kV at 5 kW in 3 hours. The vacuum
stays at approximately 9.0×10−5 Pa during the normal
operation.
The rebuncher has been used for the commissioningof the acceleration of uranium ions. The first operation
has shown that the beam intensity in fRC has been
increased twice when the rebuncher was used. Further
investigation of the optimal operation conditions suchas phase and voltage is under way.

Fig. 5. Rebuncher installed in beamline.

References
1) T. Aoki et al.: RIKEN Accel. Prog. Rep. 39, 246 (2006).
2) T. Aoki et al.: ”Rebuncher resonator between RRC andfRC in RIKEN” Proc. 3rd Annual Meet. of Particle Accel. Soc. of Jpn. and 31th Linear Accel. Meet. in Jpn.
(2006).
3) http://www.cst.com
4) http://www.ansys.com
5) L. C. Maier. Jr. and J. C. Slater: J. Appl. Phys. 23(1),68 (1952).

Fig. 4. Electric field on beam path.

From the perturbation measurements, we deduced
the voltage ratio V1 /V2 to be 1.26, where V1 and V2

2- 127 -

RIKEN Accel. Prog. Rep. 40 (2007)

Preparatio n of po ly mer coating carbon stripper foils
H. Hasebe, H. Ryuto, N. Fukunishi, A. Goto, M. Kase, and Y. Yano

Thin carbon foils (C-foils) have a common problem on
handling; they are easy to break when separated from asubstrate, mounted on a holder, or placed at a stripper
changer. There is a method of strengthening the C-foilmechanically by coating it with a polymer. Although suchpolymer-coated C-foils, whose thickness range is 3 – 20
µg/cm2, were commercially available before, thicker carbon
foils are required for the acceleration of heavy ions at the
RIKEN RI Beam Factory 1). We thus searched for the
optimumpolymer
and
found
that
poly-monochloro-para-xylylene (PPX-C) could be used forthis purpose. PPX-C also has an advantage in that it isremoved by evaporation during irradiation with a beam.
The deposition of PPX-C consists of three steps, as
shown in Fig. 1. PPX-C is produced from the same
monomer by replacing one of the aromatic hydrogens witha chlorine atom. The first step is to vaporize a solid dimer atapproximately 175°C. The second step is to cleave thevapor dimer (pyrolysis) at the two methylene-methylene
bonds at approximately 690°C to yield a stable monomeric
diradical, monochloro-para-xylylene. The final step is totransport the monomers to a room-temperature depositionchamber where they simultaneously adhere and polymerize
on a substrate.

to a low molecular weight, and because thicker PPX- C
shrank due to heat stress and resulted in a shorter lifetime
for beam irradiation than the C-foil without coating. The
thickness of PPX-C is determined by measuring thedifference in the weight of the test sample placed near thesubstrate before and after the deposition. It takes
approximately an hour for one cycle of coating.

Fig. 2. Photograph of LABCOTER (PDS 2010).
Either the arc discharge method or magnetron sputtering
can be applied to the first carbon layer. The atomic force
microscope (AFM) images of ACF-40 (Arizona Carbon
Foil Co.) 3) with and without the deposition of 20 - 30
µg/cm2 PPX-C are shown in Fig. 3. It can be seen that thesurface of carbon is smoothed. We found that PPX-C of thisthickness range can make the film sufficiently strong.

Fig. 1. Deposition of PPX-C.
The vapor deposition system LABCOTER (PDS 2010 bySpecialty Coating Systems) 2) was introduced in August,2005; a photograph of the system is shown in Fig. 2. On topof the device, a deposition chamber is placed, in which
three or four substrates of 5 inches diameter are set. Carbon
is deposited on the substrates beforehand. An appropriate
amount of dimer is set in the vaporizer, and PPX-C of 20 –30 µg/cm2 thickness is coated on the C-foils. We chosethese thicknesses because thinner PPX-C became weak due(a)(b)
Fig. 3. AFM images of ACF-40: (a) without and (b) withdeposition of 20 - 30 µg/cm2 PPX-C.
We found that the second carbon layer coated on the
PPX-C layer was hard to peel off and that multilayer films
could be fabricated using this method. Magnetron sputtering
was more suitable for the second layer onward, althougheither the arc discharge method or magnetron sputtering- 128 -

RIKEN Accel. Prog. Rep. 40 (2007)

could be applied to the first layer. When the arc discharge
method was applied to the second and other layers, pinholes were easily made in the film. The most desirable
thickness of one layer of carbon was approximately 50µg/cm2; a thicker carbon lager also caused pin holes. Figure
4 shows a photograph of the film consisting of 11 layers ofcarbon and PPX-C attached on a 5-inch-diameter glass
substrate. For this film, chloride was used as a releasing
agent. The thickness of carbon is 500 µg/cm2 in total.
PPX-C becomes blue depending on its thickness, although
it is originally colorless.

40 and 80 whose thicknesses were 10, 20, 40 and 80 µg/cm2,
respectively. The measurement was carried out by
irradiating the C-foils with a 32 keV/u 136Xe9+ beam at an
intensity of 420 pnA that was delivered from a 500 kV
Cockcroft-Walton terminal. The beam was focused on the
C-foil of 5 mm diameter. The lifetime was determined bymonitoring both the beam intensity of the stripped ions andthe C-foil image on a TV display. The results of themeasurement are shown in Fig. 7, in which the lifetimes
with and without PPX-C coating are compared for the fourtypes of C-foil. It was found that the coating caused nomarked degradation in lifetime. We also measured thelifetime of a long-lived C-foil 5) that we had developed andobserved no degradation of lifetime due to coating.

Fig. 4. Multilayer of carbon and PPX-C on substrate.
A carbon foil of 10 cm diameter and 500 µg/cm2
thickness was produced by this method, separated from thesubstrate and mounted on a foil holder (see Fig. 5). The
holder with this large film will be mounted on a
“ rotating cylinder stripper” with which the holder rotates
at 1,000 rpm 4) (see Fig. 6).

Fig. 7. Measured lifetimes of C-foils with and without
PPX-C coating. No marked degradation due to coating isobserved.
References

Fig. 5. Film mounted on holder.

1) H. Ryuto, N. Fukunishi, H. Hasebe, N. Inabe, S. Yokouchi, O.
Kamigaito, A. Goto, M. Kase, and Y. Yano, Proceedings of2005 Particle Accelerator Conference, Knoxville, Tennessee,
2005, p. 3751.
2) Specialty Coating Systems (SCS).
URL: http://www.scscoatings.com/
3) ACF-Metals Arizona Carbon Foil Co., Inc.,
URL: http://www.techexpo.com/firms/acf-metl.html.
4) H. Ryuto, H. Hasebe, N. Fukunishi, S. Yokouchi, A. Goto, M.
Kase, and Y. Yano: “Rotating charge strippers for accelerationof intense heavy-ion beams at RIKEN ”, Nucl. Instrum.
Methods Phys. Res. A 569, 697 (2006).
5) H. hasebe, M. Kase, H. Ryuto, and Y. Yano: “Long-lived
carbon stripper foils for intense heavy-ion beams”, 17th
International Conference on Cyclotrons and Their Applications(Cyclotrons 2004), Tokyo, Oct. (2004).

Fig. 6. Holder installed on “ rotating cylinder stripper”.
To investigate the effect of PPX-C on the lifetime of thefilm against beam irradiation, we measured the lifetime ofsingly coated C-foils. The C-foils used were ACF-10, 20,- 129 -

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)

Rotating cylinder charge stripper†
H. Ryuto, H. Hasebe, N. Fukunishi, S. Yokouchi, A. Goto, M. Kase, and Y. Yano
Four charge stripper sections have been prepared
for the RIKEN RI-beam factory1) . Among these sections, an approximately 0.5-mg/cm2 -thick carbon foil
is planned to be used as a charge stripper placed between the RIKEN ring cyclotron (RRC) and the ﬁxedfrequency ring cyclotron (fRC). The foil is expected toreceive a 1 kW power when a 15 pµA uranium beam
passes through the foil. A conventional method of
dealing with the heat problem is to rotate the foil.
The method increases the area from which thermalradiation is emitted. To solve the heat problem of
the charge stripper between the RRC and the fRC, arotating-cylinder charge stripper was constructed. The
rotating-cylinder charge stripper rotates a relatively
thin carbon foil that cannot be rotated by the previously constructed rotating-shaft charge stripper2) .
Figure 1 shows a schematic view of the rotatingcylinder charge stripper. A carbon foil is attached to
one of the two ends of an Al cylinder. The length andinner diameter of the cylinder are 120 mm and 100 mm,
respectively. The outer surface of the cylinder shapes
air-cooling ﬁns. Both ends of the cylinder are connected to hollow-shaft ferroﬂuid-sealed rotary-motion
feedthroughs. A timing pulley is placed between thecylinder and one of the feedthroughs. The cylinderand feedthroughs form a vacuum duct for beams. The
feedthroughs are attached to the side walls of rectangular vacuum chambers. The distance between the
beam spot and the rotation axis is 30 mm. The rectangular vacuum chambers are connected with a 165mm-diameter duct to avoid a pressure diﬀerence whileevacuating the chambers. The timing pulley and a motor placed outside the vacuum chambers are connectedwith a timing belt. The maximum rotation frequency
is 1000 rpm. The thermal radiation emitted by the
foil is absorbed by water-cooled Al disks whose surfaces facing the rotating foil are coated with thermallysprayed alumina to increase emissivity. The Al disks
are stable and have holes for beams. The operation of
the rotating-cylinder charge stripper was examined byrotating a 0.5-mg/cm2 -thick carbon foil at 500 rpm.
The foil was rotated stably without breakage.
References
1) H. Ryuto et al.: Proc. 2005 Particle Accelerator Conference, Knoxville, USA, 2005, p. 3751.
2) H. Ryuto et al.: RIKEN Accel. Prog. Rep. 38, 264(2005).

DUCT FOR PREVENTINGPRESSURE DIFFERENCEROTARY-MOTIONFEEDTHROUGH

ROTATEBEAM

C FOILCYLINDER
TV CAMERA
SLIDE

MOTOR

TV CAMERASTATIONARY RADIATION ABSORBER

Fig. 1 Schematic view of rotating-cylinder charge stripper.

†

Condensed from the article in Nucl. Instrum. Methods A
569, 697 (2006).

- 130 -

1

RIKEN40 (2007)RIKENAccel.
Accel. Prog. Rep.
Rep. 39(2006)

Measurements of beam energy and longitudinal beam profile using
plastic scintillation monitors for RIBF
T. Watanabe, M. Fujimaki, M. Wakasugi, M. Kase, N. Fukunishi, K. Yamada, Y. Kotaka, R. Koyama, A. Goto,
and Y. Yano
New plastic scintillation profile monitors (scintillation monitors) have been fabricated to evaluate the energy and longitudinal profiles of heavy-ion beams for
the RIKEN RI beam factory (RIBF)1) . Four sets ofscintillation monitors (8 monitors) were installed into
the transport lines of the RIKEN heavy-ion linac (RILAC), the RIKEN ring cyclotron (RRC), the fixedfrequency ring cyclotron (fRC) and the intermediatestage ring cyclotron (IRC) to measure the accelerated
energy of heavy-ion beams. Furthermore, two scintillation monitors were also installed into the transportline upstream of the injection point of the RRC and thefRC to optimize the phases of the rebunchers. Preliminary experimental results obtained during the commissioning of the RIBF using the heavy-ion beams aredescribed in this article.
When a scintillation material is struck by a charged
particle, fluorescence photons are produced. Then,these photons are amplified by a photomultiplier thathas extremely high sensitivity. Longitudinal beamprofiles are obtained using a time-to-digital converter(TDC), which digitizes the time lag between the startpulse (deteced signal) and the stop pulse (bunch clock).
The energy of the beam can be obtained from the measured time of flight (TOF) of the beam using a longitudinal profile monitor set. A photograph of the longitudinal profile monitor installed into the transport line
between the RRC and the IRC are shown in Fig. 1.
The plastic scintillator is pneumatically inserted into
the beam transport chamber by the pneumatic rotary

Fig. 2. Time spectra (D15, D18) measured using 84 Kr26+(45.4 MeV/u) beam, which represent longitudinal beamprofile.

feeder when the measurement is started.
The energy measurements of a 84 Kr26+ (45.4
MeV/u) beam accelerated by the RRC were carriedout using the TOF method. To maintain the minimal background, the Kr beam was attenuated to between 200 s−1 and 300 s−1 , and the stop pulse wasTable 1. By fitting time spectra in Fig. 2 using Gaussian
curves, center times (TD15 , TD18 ) of spectra and thelongitudinal phase widths (1-σ) were obtained and results were tabulated.
Location
D15
D18

Center (ns)31.724 (TD15 )23.447 (TD18 )

1-σ (ns)
1.104
1.213

1-σ (deg.)
14.51
15.94

Table 2. Nominal and measured values of TOF, β (ratio ofbeam velocity to light velocity) and energy of 84 Kr26+
beam.

Fig. 1. Photograph of longitudinal profile monitor using
plastic scintillator installed into transport line between
RRC and fRC.

- 131 -

Nominal values
Measured values

TOF (ns)228.08227.56

β0.301462
0.302153

Energy (MeV/u)
45.4
45.62
∆E/E=+0.48%

1RIKEN Accel. Prog. Rep. 40 (2007)
Table 3. Measured FWHM of the longitudinal phase width
under several conditions.

6000

D18

TDC Yield

5000
4000

Stripper on
Rebuncher on

3000

Stripper off
238

238

2000

Condition
Rebuncher off
Stripper off
Rebuncher on

U +73

1000
0
5

10

15

20

25

30

Time (ns)Fig. 3. Measured time spectra of a 238 U35+ and a 238 U73+
(10.75 MeV/u) beam.

operated at an RF frequency of 36.5 MHz (a period(τRF ) of 27.3973 ns) in the measurements. The time
spectra measured at D15 and D18 using the 84 Kr26+
beam, which represent the longitudinal beam profile,
are shown in Fig. 2. By fitting the time spectra in
Fig. 2 using Gaussian curves, the center times (TD15 ,TD18 ) of the spectra and the longitudinal phase widths(1-σ) were obtained and the results are shown in Table 3. The time of flight (τtof ) between D15 and D16
is given byτtof = k × τRF + (TD15 − TD18 ),(1)

where k is a wave number. The length L between the
scintillation monitor of D15 and a scintillation monitorof D18 was measured to be 20.611 m using a laser distance meter, which has a measuring accuracy of ±1.5
mm. The kinematic energy of the beam T is given by
β = L/(τtof × c),p
T = E0 (1/ 1 − β 2 − 1),(2)

where β is the ratio of beam velocity (v) to light velocity (c) and E0 is the rest mass of the heavy ion. By
using these equations, the energy of the 84 Kr26+ beam
was obtained and the nominal and measured values
are shown in Table 2. Finally, it was found that theenergy difference (∆E/E) between the nominal value
and the measured value was +0.48%. Hence, the beam
was operated under appropriate conditions.
To optimize phases of the rebuncher2) , preliminary
measurements of the longitudinal profiles of a 238 U35+
beam and a 238 U73+ (10.75 MeV/u) beam were carriedout. For the experimental measurements, the scintillation profile monitor of D18, located relatively close
to the injector of the fRC and far from the rebuncher(11.096 m), was used. The time spectra were taken

2

1-σ (ns)
2.054
0.611
1.25

1-σ (deg.)
17.99
5.35
10.97

U +35

Stripper on
Rebuncher off

0

Center (ns)
4.60
17.83
5.45

- 132 -

under the same conditions used for the TOF measurement, and the results are shown in Fig. 3. The results show that the longitudinal phase width were 5.35
deg. in FWHM (carbon stripper off) and 17.99 deg.
in FWHM (carbon stripper on). However, it has beenfound that the rebuncher, which was operated at afrequency of 109.5 MHz (a period of 9.1324 ns), compressed the longitudinal phase width from 17.99 deg.
to 10.97 deg. according to these measurements.
The CAMAC system used for data acquisition iscontrolled by a Linux-based PC, and the PC is linked
to a laptop in the main control room located 200 m
from the RRC hall using Ethernet. The measured results are displayed by the PAW++ based on several
components of the CERN Program Library. The driving control and status monitoring of the plastic scintillator are controlled by the EPICS system3) .
The authors thank the operation crews for theirgreat help.
References
1) T. Watanabe et al.: RIKEN Accel. Rep. 39, 241 (2006).
2) T. Aoki et al.: RIKEN Accel. Rep. 39, 246 (2006).
3) M. Kobayashi-Komiyama et al.: RIKEN Accel. Rep.
37, 277 (2004).

RIKEN40 (2007)RIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 40(2007)Development of new HTS current sensor and HTS magnetic shields
for HTS-SQUID monitor
T. Watanabe, Y. Sasaki,∗1 M. Kase, S. Watanabe,∗2 T. Ikeda, T. Kawaguchi∗3 and Y. Yano
Last year, a prototype of a highly sensitive beam current monitor with a high-temperature superconducting (HTS) SQUID and an HTS magnetic shield1–8) ,that is, the HTS-SQUID monitor, was installed in the
beam transport line of the RIKEN Ring Cyclotron(RRC). As a result, a 10 µA 40 Ar15+ beam intensity (63 MeV/u) was successfully measured with a 500
nA resolution9,10) . Although the intensity of a submicroampere beam can be measured, a minimum current
resolution lower than two orders of magnitude (1nA)
is required for the measurements of fainter heavy ion
beams. Therefore, we have developed a new HTSSQUID and high-permeability cores introduced into
two input coils of the HTS-SQUID to improve sensitivity. These are very important parts for a new current
sensor of the HTS-SQUID monitor. A test using a current wire for simulating beam current shows a 50-foldimprovement in gain, because the newly installed highpermeability cores and SQUID improved the transfer
coupling efficiency of the magnetic field induced by thebeam current9,10) .
This year, both the new HTS current sensor andthe new HTS magnetic shields were developed. Their
schematic drawing is shown in Fig. 1 and a pictureof Ag substrates are shown in Fig. 2. The substrates
made of MgO ceramic tubes used for the prototype
HTS SQUID monitor were changed to substrates madeof 99.9% silver (Ag), because the new substrates mustbe fabricated precisely. Then, the surfaces of the sub-213

Current Sensor(Bridge)Fig. 2. Picture of Ag substrates of new HTS current sensor,
HTS cylindrical magnetic shield and coaxial magnetic
shields.

strates are coated by a thin layer (70 µm) of Bi2 -Sr2 Ca1 -Cu2 -Ox (Bi-2212), which is a high-temperature
superconducting material11) . Although silver has ahigh conductivity and is used as the material of thesubstrates, there are no problems encountered in its
use. Because the superconducting material has a completely zero resistance, then the current should flow
only in the superconducting material. In addition,

A

A

98

203

8

35

A'

CoaxialMagnetic ShieldA'

Cylindrical
Magnetic Shield

(a)

(b)

Fig. 1. Schematic drawing of new HTS current sensor and
HTS magnetic shields for HTS-SQUID monitor.
∗1
∗2
∗3

Matsushita Electric Industrial
Center for Nuclear Study (CNS), Graduate School of Science, University of Tokyo
KT Science Ltd.

Fig. 3. (a) Ag substrate of the coaxial magnetic shield. (b)HTS coaxial magnetic shield coated by the thin layerof Bi2212.

- 133 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

it was observed using an Electron Probe (X-ray) Micro Analyzer (EPMA) in RIKEN that the surface ofthe HTS material Bi2212 was clearly smooth and that
Bi2212 adhered strongly to the Ag substrate comparedwith Bi22238). The Ag tube used as the current sensor
is coated by a thin layer of Bi2212 on both the innerand outer walls of the tube. While a beam is passing
through the tube, a shielding current produced by the
Meissner effect flows in the opposite direction along thewall, so as to screen the magnetic field generated by
the beam. The surface of the outer wall has a narrowslit without coating Bi2212 to form a bridge circuit.
Then, the induced current concentrates in the bridge
circuit and forms an azimuthal field. The HTS SQUID
is located near the bridge circuit and can detect theazimuthal magnetic field. The HTS magnetic shields
that are used on the basis of the Meissner effect consist of coaxial magnetic shields, a cylindrical magnetic
shield and also the current sensor. The current sensor
plays an important role for not only the current detector but also the magnetic shielding. Then, the SQUID
is almost surrounded by the HTS magnetic shields toshield environmental magnetic noise strongly. Regarding the processing, we fabricated several parts: (1) two
cylinders and one disk with a hole for the substrates ofeach coaxial magnetic shield, and (2) one cylinder andthe bridge for the substrate of the current sensor. Afterthe fabrication, we welded each part by electron beam
welding. The measured processing accuracy after theelectron beam welding was within ±100 µm.
Now, we have coated the thin layer of Bi2212 on
all the substrates. Figure 3(a) shows the Ag substrate of the coaxial magnetic shield and (b) shows
the one coated by the thin layer of Bi2212. The current sensor and cylindrical magnetic shield could be
fabricated with no problems. However, some pinholes
were formed after coating the HTS material on thesubstrates of the coaxial magnetic shields. We are
now in the process of completing the coaxial magnetic shields as well as preventing the formation of
pinholes by grinding the surface of the Ag substrates,
and changing the baking temperature and thickness ofBi2212.
The authors are grateful to S. Ono, B. Mizuno, H.
Kanada, N. Murakami, S. Kojima and N. Amazaki for
their fruitful collaboration.
References
1) T. Watanabe et al.: RIKEN Accel. Rep. 35, 314 (2002).
2) T. Watanabe et al.: Proc. 8th European Particle Acc.
Conf., Paris, France, 2002-6, (EPS-IGA, 2002) p. 1995.
3) T. Watanabe et al.: RIKEN Accel. Rep. 36, 331 (2003).
4) T. Watanabe et al.: CNS Annual Rep. 59, 71 (2003).
5) T. Watanabe et al.: Proc. 14th Symp. on Acc. Sci. andTechnology, Tsukuba, 2003-11, (KEK 2003), p. 99.
6) T. Watanabe et al.: RIKEN Accel. Rep. 37, 310 (2004).
7) T. Watanabe et al.: Supercond. Sci. and Technol. 17,
S450 (2004).

2- 134 -

8) T. Watanabe et al.: RIKEN Accel. Rep. 38, 273 (2005).
9) T. Watanabe et al.: Proc. 7th Symp. on European Conf.
on Appl. Supercond., Vienna, 2005-9, (IOP publishing,2006), 43, p. 1215.
10) T. Watanabe et al.: RIKEN Accel. Rep. 39, 243(2006).
11) Y. Ishikawa et al.: Advances in Supercond. (ISS’91) 4
1992 p. 1076.

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4040(2007)(2007)

Construction of vacuum pumping system
for RIBF beam transport line
S. Yokouchi, M. Fujimaki, N. Fukunishi, M. Nishida,∗ and M. Kase
The vacuum pumping system for the injection andextraction beam transport (BT) lines of the fRC wereconstructed from June to October 2006. A part ofthe existing BT line from the RRC was modiﬁed tobe applied to the fRC injection line. The vacuum
pumping system for the BT line from the IRC to the
SRC, which was nearly completed in 2005, was connected with the SRC in November 2006, and the vacuum pumping system for all the BT lines to the SRC
was completed. Figure 1 shows a schematic layout ofthe vacuum pumping system for the BT lines from theRRC to the SRC in the RIBF.
The vacuum pumping system for the BT lines is divided into some sections by gate valves (GVs). Eachsection has one or two vacuum pumping units (VPUs).
A VPU is composed of a turbomolecular pump, GVs,
vacuum gauges, a local controller, and other vacuum
components.1) Figure 2 shows a photograph of the
VPU installed in the BT line, and Fig. 3 shows that of
the local controllers mounted on a rack. The attainableaverage pressure along the BT line was designed to be
below 2 × 10−5 Pa. The VPUs and GVs can be operated both locally using their controllers and remotelyfrom the control console.
After the installation of magnets, ﬁrst, the beamdiagnostic chambers made of aluminum alloy were installed precisely on robust frames at their ﬁxed positions. Vacuum ducts, bellows, and GVs, all of whichwere made of aluminum alloy, were constructed between those chambers. VPUs were mounted on theirﬁxed chambers, whereas their local controllers were in-Fig. 3. Local controller of VPU.

stalled at some places free from radiation. Electric
wiring and pneumatic piping works were carried out
last.
The up-to-date pressures measured at each VPU arelisted in Table 1. From these data, the actual averagepressure along the BT lines seems to be higher thanthe expected pressure. The cause of this disagreement
will be investigated later.
Table 1. Measured pressures at VPU. Measured on 30
Nov. 2006.
Unit
TP-A01
TP-A11
TP-D11
TP-D13
TP-D61
TP-D14
TP-D16
TP-D17
TP-D1A
TP-F41
TP-F01b
TP-DA1aTP-DA2TP-DA4aTP-AA6

Pressure(Pa)
1.9 × 10−5
1.3 × 10−5
5.5 × 10−5
1.6 × 10−4
9.0 × 10−6
8.4 × 10−6
2.6 × 10−6
1.1 × 10−4
1.3 × 10−5
1.5 × 10−5
1.9 × 10−5
8.9 × 10−6
1.0 × 10−5
4.1 × 10−6
1.1 × 10−4

Unit
TP-A03
TP-M04
TP-Str
TP-M11
TP-H12b
TP-H18TP-H31
TP-K51
TP-K01
TP-K02
TP-G10TP-G12TP-G21
TP-G26
TP-K40Pressure(Pa)
1.3 × 10−4
1.2 × 10−5
6.4 × 10−5
1.2 × 10−4
6.5 × 10−5
3.8 × 10−5
3.0 × 10−5
3.1 × 10−5
5.9 × 10−5
1.7 × 10−5
3.4 × 10−5
3.1 × 10−5
1.4 × 10−5
1.4 × 10−4
6.2 × 10−5

References
Fig. 2. VPU.
∗

1) S. Yokouch et al.:275(2004).

RIKEN Accel. Prog. Rep. 37,

SHI Accelerator Service, Ltd.

- 135 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 1. Schematic layout of vacuum pumping system for BT line2

- 136 -

RIKEN Accel. Prog. Rep. 40 (2007)
㻃
㻃

Status of the SRC
H. Okuno, J. Ohnishi, K. Yamada, N. Fukunishi, T. Maie, K. Ikegami, M. Hamanaka䟼1 , A. Goto, M. Kase and Y. Yano

In this paper, we report the progress of the SRC for the
first beam scheduled in 2006. The second cool-down of the
SRC started on March 16th and the superconducting magnet
was fully excited on April 15th again. Magnetic fieldmeasurements were carried out for two months to evaluate
the qualities of the generated fields and to develop a
database for various acceleration conditions. The details of
the measurements are described in reference [1]. We
performed a fast-shutdown test when all thesuperconducting coils were at full excitation on June 14th.
This test is very important to check the coil protection
system. After the fast-shutdown test, the construction of theparts other than the superconducting magnet system wasstarted. On June 25th, four acceleration resonators and one
flattop resonator were installed as shown in Fig. 1. After the
resonators were aligned carefully, they were connected withthe sector magnets to make a vacuum chamber for ion
beams. Parts used for the connections are shown in Fig. 2.
Evacuation pumps and beam diagonics were also installed.
Figure 3 shows the main radial probe (MDP) installed in thevacuum chamber. On September 29th a rough pumping of
the beam chamber was started for a leak test, which foundseveral leaks at flanges. On October 24th, the cryopump was
switched on and the vacuum reached 5.0 x 10-6 Pa, which isthe designed value. The superconducting coils were fully
excited several times to check that the AC servo motors,
flow switches and electromagnetic valves inside or near the
SRC work properly under stray fields from the sector
magnets. Local magnetic shields made of iron were applied
to the parts that did not work properly under the stray fields.
We started acceleration tests on the SRC after aging theresonators in various magnetic field levels induced by thesector magnets. Finally the first beam was extracted fromthe SRC on December 28th.

Fig. 1. Installation of acceleration resonator.

Fig. 2. Structure of the connection between the resonatorsand the sector magnets.

Fig. 3. A head of the MDP (main differential probe) for the
SRC.
䟼

1

SHI Acceleration Service Ltd.

References[1] J. Ohnishi, et. al.: in this progress report.

- 137 -

RIKEN Accel. Prog. Rep. 40 (2007)

Present Status of Liquid-Helium Supply and Recovery System
K. Ikegami, H. Okuno, T. Yoshida, K. Nakano, T. Maie, H. Hasebe, M. Nakamura, and M. Kase

The liquid-helium supply and recovery system, which
can generate liquid helium at a rate of 200 L/h from pure
helium gas, has been stably operated since the beginning ofApril 2001. The volumes of liquid helium supplied per year
are listed in Table 1. The volume supplied has gradually
increased over the years since 2001. The volume supplied
to the low-temperature physics laboratory from 2004 to 2005
markedly increased more than threefold. The reason is theextensive implemention of the nanoscience project.
A recovery helium gas observation system1) for
measuring helium of the recovered helium gas wascompleted at the beginning of May. The system
consists of eight data recorders (Daqstation DX1000)
made by Yokogawa Co., and 13 helium purity sensors
distributed in the Wako campus. The purity of thehelium gas recovered from laboratories is improved
gradually after the completion of the system. At theend of August, the control system of the liquid-helium
supply and recovery system, which is called MPICS(multiperformance
integrate
controlsystem)developed by Taiyo Nissan Co., was replaced.
The measuring and tally system for liquid helium
supplied to the researchers was completed at the endof October. The system measures the weight ofliquid helium and stores the measured weight to a
database installed in a computer. Figure 1 shows aphotograph of the liquid helium measuring and tally

system.

Fig. 1. Liquid helium measuring and tally system.

Reference
K. Ikegami et al.: RIKEN Accel. Prog. Rep. 39, 254 (2005).

Year
2001
2002
2003
2004
Laboratory and instituteAmount of supplied liquid helium (ℓ)
Magnetic materials laboratory
3392
7024
7713
11829
Low-temperature physics laboratory
1270
3090
6966
9515
Advanced device laboratory
9977
10849
9726
7401
Condensed molecular materials laboratory
1939
1615
3079
5353
Surface chemistry laboratory
1146
1676
4533
5007
Brain science institute
6277
8144
5055
6292
Etc. (others laboratories)
3535
7730
14476
9487
Total
27536
40182
51530
54884
Table 1. Volumes of liquid helium supplied to laboratories per year from 2001 to 2005.

- 138 -

2005
15672
34713
11264
5912
5370
7285
15717
95933

㻃RIKEN Accel. Prog. Rep. 40 (2007)

New Energy Establishment Committee of Wako City District and RIBF
T. Fujinawa, M. Kitano*1, M. Watanabe*2and Y. Yano
Wako city is within commuting distance of Tokyo and features
easy living. This area also experiences no gale force winds (yearly
average 1m /s) or dry spells. The area also receives 1600 hours ofsunlight per year.
The population was approximately 72,000 in 2004 and which
increases by 1400 people every year on average. The city covers
an area of 11.04 km2, is 40.71 m above sea level, and has a yearly
average ambient temperature of 15.2℃.
The new energy establishment committee of Wako city）
district1 was established on 26 August 2005. This committee is inline with the basic policy of the Rationalization of Energy Use
Law and Kyoto Protocol. This committee is also supported by the
New Energy and Industrial Technology Development
Organization (NEDO).
The committee researched potential new energy sources
available to this district. The results are as follows.
1. Solar energy, wind force power generation, andmini-hydropower among others are the supply side (natural)
potential power sources. Environmentally friendly cars andvehicles, natural gas cogeneration and fuel cells are the demandside (energy saving/efficient) aspects related to energy users.
2. The regarding situations installations of new energy
equipment are as follows.
The ratio of solar cell power generation for 10,000 people ofWako city is 37 kW. However, this is less than the national
average of 49 kW. RIKEN has a solar cell capacity of 10 kW. The
sunlight received by the Wako city district is only 1600 h/year,
which is low compared with other districts around the country.
For example Ota city in Gunma prefecture has 2000 h of 8760 h（a year） sunshine time.
The percentage of clean cars and vehicles in the Wako city withrespect to the total number of cars is 0.4%, which is the same as
the national average.
࣬ Wako city’s power generation through Natural Gas
Cogeneration (CGS) is 1 MW for 10,000 people, which is fivetimes larger than the national average of 185 kW. The generatorof the CGS of RIKEN’s RIBF produces more power than any
other single CGS within Tokyo Gas’s supply district for general
consumer use. Due to the success of RIBF’s CGS, several otherbusinesses and organizations in Wako city are also using thissystem for their power and hot water requirements. Currently,
there are nine systems in use within Wako city, which is well
above the national average for use of this system (See table 1).
3.Temperature difference energy will be the main characteristicenergy of the Wako region.
The RI Beam Factory (RIBF) is under construction asscheduled. The completion of the RIBF will be a great
achievement for RIKEN enabling further advances in nuclear
physics and other fields. However, the accelerators require ahuge amount of electricity (25 MW) and generate large amountsof heat. The accelerator will run 24h/day, totaling more than 6500
hrs/year, but this will also produce a constant supply of warm
(40°C) water.
Our plan is as follows. In the first stage, cross-linked poly
ethylene (XLPE) hot insulation piping, (known as “onsen piping”)
which is mainly used for spas, will be laid down between the
RIBF and the 4th elementary school, which is situated next to
RIKEN’s RIBF.
A pair of 95 mm-diameter pipes will transport 51 m3/h of warm
water to and from the school. At this rate of flow, the energy at
5°C temperature difference is equal to 255 Mcal, which isequivalent to 297 kW/h = 1,067.6 MJ.
In terms of petroleum oil, this is equivalent to 275 KL/h (1MJ=258 L) which means that more than a drum of petroleum oil
can be saved each hour. This is referred to as Monergy. In
winter, this water will be used for heating class rooms and otherrooms at the school with “base board heaters”. It will also supply
heat to the swimming pool in early summer and autumn.
In the second stage, heat will be supplied to the National
Saitama Medical Center via the 4th elementary school’s piping.
The hospital requires steam for sterilization, humidification, andheat. The hospital also uses large amounts of hot water. For thisreason the Wako Medical Center is using the CGS. RIBF can also
supply hot water to the hospital boilers.
The cooling water from the CGS absorption chiller isrecommended for this application because of its nonstop year
round supply and the absence of radio activity.
At the completion of this project, Wako city will have a newenergy source for parts of the local community and RIBF will
supply this energy.

- 139 -

Name

Capacity

Unit

1

RIKEN RIBF

6500kW1

2

Tax practice Academy

300kW

1

3

Legal Research and Training Institute

200kW

1

4

Wako medical center

90kW

1

5

Sports club

28kW

1

6

Chinese restaurant

6kW

1

7

Wakocity elder care facility

9.9kW

3

7154KW

9

Total

㻃

Table-1 CGS List
References
1) M. Kitano et al.: Wako city district new energy vision.
2006 Feb.
2) T.Fujinawa et al.: RIKEN Accel. Prog. Rep. 36,310(2003)*1 Department of Applied Chemistry School of Science andTechnology Meiji University.
*2 Wako City office.
RIKEN Accel. Prog. Rep. 40 (2007)

Spin mismatch of the AGS
J. Takano＊1, ＊2, ＊3
To preserve the polarization of protons in the Alternating
Gradient Synchrotron (AGS), partial Siberian snakes havebeen installed. The first partial Siberian snake is the
Solenoidal Snake (SSNK)1), which was used to overcome
all imperfection resonance. The AGS has another strong
depolarizing resonance, which is called intrinsic resonance.
Four strong intrinsic resonances can be avoided by using
the RF dipole2). With these components, 40% polarization
was achieved at the AGS extraction energy in 2003.
However, the Solenoidal Snake produces transverse
coupling resonance, which is caused by the coupling of thehorizontal-vertical betatron oscillation of the beam. To
reduce the coupling resonance and overcome allimperfection resonance, a normal conducting helical dipole
Siberian snake (Warm Snake, WSNK)3) was developed.
With the WSNK and the RF dipole, 50% polarization wasachieved in 2004 and 55% in 2005.
To overcome all intrinsic resonance and imperfection
resonance with a component, a superconducting helical
dipole partial Siberian snake (Cold Snake, CSNK)4) has
been installed. However, with only the Cold Snake, the spin
mismatch should be larger at AGS injection and extraction,
since the spin stable direction (SSD) in the synchrotron haslarge precession when using the strong partial Siberiansnake. To reduce the spin mismatch, the double-snake
scheme5) was proposed and realized in 2006. As the result,
65% polarization was achieved with the Cold Snake and theWarm Snake without using the RF dipole. In this case, thespin mismatch was reduced, but it still had small spin
mismatches. To make the mismatch be zero, the triple-snake
scheme is a good solution. If the snakes are located along
1/3 of the ring, they will work effectively for the spin tune
gap and spin mismatch. On the basis of this idea, the Cold
Snake and the Warm Snake were placed along 1/3 of thering. However, the Solenoidal Snake was not positioned at
the ideal point. If the Solenoidal Snake is relocated to asymmetrical point relative to the Warm Snake and the Cold
Snake, the Solenoidal Snake will be effective in reducing
the spin mismatch.
The strengths of the Cold Snake and Solenoidal Snakeare variable. Table 1 shows several patterns of snake
strength combinations and spin matching at AGS injection.
The percentages represent the degrees of spin direction
tilted by the snake. For example, the 10% snake can tilt thedirection by 18 degrees.

＊1
＊2
＊3

TABLE1. Spin matching with partial snakes
Case

CSNK

WSNK

SSNK

A

15%

97.2%

B

10%

98.8%

C

10%

6%

99.8%

D

6%

6%

100%

E

10%

6%

4%

Spin matching100%

On comparing cases A, B and C, the double-snake
scheme is found to reduce the spin mismatch. If the strengthof the Cold Snake is reduced, as in case D, the spin
mismatch will be cancelled completely. In this case, thespin tune gap may not be sufficient to overcome theintrinsic resonance. In the 2006 run, case D was operated
briefly and 60% polarization was achieved at the AGS
extraction energy. The experimental result indicated that the
intrinsic resonance could be overcome with a weak Cold
Snake and the Warm Snake. If the closed orbit of the AGS
beam is optimized, the polarization will be increased.
We have another choice for reducing the spin mismatchwith the combination of the three snakes: case E. If the
Solenoidal Snake is relocated to the ideal point, the spin
mismatch can be cancelled completely by adjusting thestrength of the Solenoidal Snake. With this combination, thespin tune gap is larger than that in case D. Therefore it will
be easy to overcome the depolarizing resonance. However,the coupling resonance should be considered in using case
E. To overcome the horizontal intrinsic resonance as well,the horizontal betatron tune is going to be optimized in thenext polarized proton run in the AGS. The operation withno spin mismatch, such as cases D and E, will increase thepolarization at AGS extraction.
References
1) H. Huang et al.: Phys. Rev. Lett. 73, 2982 (1994); Ph. D. thesis
Indiana University (1995)
2) M. Bai: Ph. D. thesis, Univ. of Indiana (1999)
3) J. Takano et al.: Proc. of 2005 Particle Accelerator Conference,
Knoxville, TN, 1003 (2005)
4) H. Huang et al.: Proc. of 2005 Particle Accelerator Conference,
Knoxville, TN, 1404 (2005)
5) T. Roser et al.: Proc. of SPIN2004, Trieste, 687 (2004)

RIKEN, Saitama, Japan
Brookhaven National Laboratory, Upton, NY 11973, USA
RLNR, Tokyo Institute of Technology, Tokyo, Japan- 140 -

RIKEN Accel. Prog. Rep. 40 (2007)

Laser based heavy ion production†
M. Okamura,＊1 J. Tamura,＊2 T. Kanesue,＊3 R. A. Jameson,＊4 andGenerally, laser ion source (LIS) is advantageous forproviding intense pulsed heavy ion beams with a highly
charged state. To meet a particular purpose, someparameters of the LIS must be selected carefully.
A typical LIS consists of a laser system, a target and an
extraction electrode, as shown in Fig.1. Here, we assume
that the laser pulse duration is in the range from 1 ns to 100
ns. During 1 ns of laser irradiation, the plasma expands up
to 4.5 mm, which is much longer than the focusing laser
spot size, assuming an expansion speed of 100 eV/u, which
is a typical speed of the ion energy included by a laser
plasma.
Plasm

x

PlasmaLase
Ion
Target
~ns

z

20~30
~ a fewz
Drift∼μs length

Extraction

Fig. 1 LIS scheme

This condition causes the laser power to first be mainly
absorbed by electrons in the plasma, and then, stepwise
ionization occurs. The plasma travels to an extraction
region with a very high momentum spread and becomesthinner. Then, ions can be extracted to form the initial ion
beam.
In generally solid material is used as a target. The purityof the target material is very important. It was proved that apure graphite target with less than 5 ppm of impurity did
not show even a hydrogen peak in our plasma analysis
experiment using a secondary electron multiplier detector.
The ratio of isotopes and the oxidized surface condition
should be also taken care of. For instance, it is difficult toobtain a pure beam from a Ti target without any special
treatment. Also the stability of a beam of heavier species ismore difficult to maintain.
Higher laser power generates more ions. Higher laser
power density on the target produces higher charge statesand higher velocity of the plasma expansion. We found thateach laser has its own limitation in the heaviness of thetarget element. We tested two laser systems, a Nd-Glasslaser and a Nd-YAG laser. The glass laser could ionize ironwith reasonable charge states, but could not produce highly
charged ions from materials heavier than iron. For example,
Ge and Nb were ionized up to 8+ and 9+, respectively. The
YAG laser, which has a shorter pulse duration, could ionize
up to silver ions. If we require highly charged ions fromTa or Au, a higher power density laser beam will be needed.
On the other hand, 200 ~ 300 mJ 10 ns laser is sufficient toprovide C6+. It is commonly said a shorter wavelength ofthe laser is better for†

Condensed from the proceedings of LINAC 2006.
Brookhaven National Laboratory, USA＊2Tokyo Institute of Technology＊3
Kyusyu University＊4Frankfurt University, Germany＊5
Institute for Theoretical and Physical Experiment, Russia＊1

S. Kondrashev＊5

Table 1: Limitation in heaviness of species.
Laser

Power

Width

Ions

Nd Glass-1062 nm

3.45 J

37 ns

Up to Fe17+

Nd-YAG-1064 nm

2.3 J

6 ns

Up to Ag15+

energy absorption. However the wavelength depends on thelaser medium. Usually, there are stronger constraints due tolaser availability on the market.
The emittance of the laser beam affects the achievablefocusing spot size, similarly to ion beam optics. Also, theeffect of the wavelength should be considered.
A shorter focal length of the final focusing element can
provide higher power density, and its value is determinedby the geometrical configuration in the ion source chamber.
The distance between the target and ion extraction point
determines the ion pulse duration. The laser pulse is only 1~ 100 ns and it takes the plasma 2 ~ 3 μs to travel within
this distance. If a 10 μs of ion pulse is needed, the plasma
drift length must typically be 2 ~ 4 m. In this case, a higher
power laser is needed to compensate the low ion density atthe extraction point. The ion pulse width is proportional tothe plasma drift length and the peak current amplitude isinversely proportional to the cube of this value. These
relations were verified in our experiments. Also, the solid
angle for capturing the expanding plasma is important,since the plasma starts from a pinpoint on the target.
As a result, a short plasma drift length dramatically
improves the ion capturing efficiency. However, in this case,a strong electric field is required for ion extraction, andspace-charge repulsion force becomes serious after the
extraction. The direct plasma injection scheme (DPIS) can
overcome these issues. A target can be placed
approximately 30 cm upstream of the entrance of afirst-stage linear accelerator, typically an RFQ. The induced
plasma is guided through a pipe to the inside of the RFQ
tank and then the contained ions are extracted in the tank.
All the high voltage parts can be inside the compact vacuumbox.
To obtain a beam matched with the RFQ input acceptance,
the incoming beam must be focused, in general. On thecontrary, in the DPIS scheme, the diverging beam is
injected into the RFQ. The extracted beam emittance fromthe guide pipe changes due to the density variation of theplasma in a single pulse and it is almost impossible toachieve a perfect matching condition. However, using DPIS,
the ion density is very high and only the overlapped area ofthe beam emittance and the RFQ acceptance contains asufficient number of ions. As a result, we can accelerate an
intense beam easily without the need for an LEBT that
includes a complex focusing magnet. This scheme is well
suited for providing an intense pulsed beam.
References
1) M. Okamura et al,: Radiation Effects & Defects in Solids,
160, 10-12 (2005) 445-449.
- 141 -

RIKEN Accel. Prog. Rep. 40 (2007)

Aluminum beam acceleration with DPIS†
J. Tamura,䟼1

M. Okamura, 䟼2 T. Kanesue,䟼3 R. A. Jameson,䟼4 andSince end of the last year, we have studied acceleration of
Aluminum ions with direct plasma injection scheme (DPIS).
In this experiment, the 4 rod RFQ fabricated in IAP(Institute of Applied Physics, Frankfurt University) and the
2.3 J 6 ns Nd-YAG laser, thales SAGA230, were used. The
basic parameters of the RFQ are summarized in Table 1.

Iout at 100 mA C4+ in
Injection energy
Extraction energy
Acceptance
Aperture䟼1

Tokyo Institute of Technology

䟼2

Brookhaven National Laboratory, USA䟼3

Kyusyu University

䟼4Frankfurt University, Germany

䟼5Institute for Theoretical and Physical Experiment, Russia

The charge state distribution was measured using an electro
static analyzer situated after the RFQ. Figure 2 indicatedanalyzed result. The fraction of Al9+ was about 65 % of thetotal current.
Shot-to-shot reproducibility of output RFQ current
amplitude over 150 shots was investigated. The fluctuation
was ±6% for total current. In the experiment, RF frequency
has been tuned manually. Automatic phase tuning is
expected to improve the statistics. The result is shown in
Fig. 3.

Table 1 : Basic design parameters of the RFQ
Frequency
Total length
Modulated vane lengthIntervane voltage

S. Kondrashev䟼5

100 MHz
2.0 m
1.42m
120 kV (q/A =4/12)
76 mA (pteq-H)
20 keV/u
100 keV/u0.14 cm.rad
0.655 cm

Fig. 2 Analyzed accelerated Al beam.

Fig. 1 Accelerated beam shape.
Figure 1 shows accelerated currents varying the extraction
voltage. Although the laser is capable of producing Al12+,
the laser power density was optimized to get Al9+. The
extraction voltage of 60 kV matches q/A = 9/27 condition.
Due to the changing extraction condition, a dip caused by
too high plasma density was observed at lower extraction
voltages. The longer plasma drift length will reduce thedensity at the peak position and longer ion beam pulse
might give more total number of ions. Maximum current
and pulse duration are 60 mA and 0.65 µs for extraction
potentials in the range of 70-90 kV.
†

Condensed from the proceeding of High Intensity High Brightness

Hadron Beams, Tsukuba, May 2006, THBY01.

Figure 3: Shot-to-shot fluctuations of output RFQ current
amplitude and pulse duration (extraction potential – 60 kV,
RF voltage amplitude – 120 kV).

- 142 -

RIKEN Accel. Prog. Rep. 40 (2007)

We also trying to use gas at room temperature as a LIS
target. Except He, almost all the gas can be condensed oncooled substrate. We confirmed that a surface of acryo-cooled 5 K Cu block can capture rare gases and thefrozen rare gas can provide a plasma by a laser irradiation.
In the experiment, we could obtain Ne plasma which
expected to provide mA class ion beam from the RFQ.
Analysis of the experimental result is in progress.
Reference[1] Masahiro Okamura, Hirotsugu Kashiwagi,
Kazuhiko Sakakibara, Jumpei Takano, Toshiyuki
Hattori, Noriyosu Hayashizaki, Robert A. Jameson,
and Kazuo Yamamoto, “High current carbon beam
production with direct plasma injection scheme”,
Rev. Sci. Instrum. 77, 03B303 (2006)[2] M. Kojima, K. Nishigori, M. Yoshida, A. Sakumi, J.
Hasegawa, U. Funk, U. Neuner, Y. Oguri and M. Ogawa,“laser plasma induced from solid hydrogen for
beam–plasma interaction”, Nuclear Instruments andMethods in Physics Research A 464 (2001) 262-266- 143 -

RIKENRIKENAccel.
Accel.Prog.
Prog.Rep.
Rep. 40
40(2007)(2007)Development of ion-guiding system for RIABR experiments
T. Sugimoto, A. Yoshimi, H. Ueno, J. Murata,∗1 H. Kawamura,∗1 D. Nagae,∗2 K. Shimada,∗2 and K. Asahi
The atomic-beam resonance (ABR) method is aneffective tool for determining nuclear moments.1) We
have worked on developing a new technique for applying the ABR method to the measurement of thenuclear moments of radioisotopes (RIs). In this paper,
we report the present status of the development of anion-guiding system. This ion-guiding system will be
used to produce a low-energy RI atomic beam in the
ABR system.
The test experiments were performed at the Cyclotron and Radioisotope Center of Tohoku University.
A primary 15 N5+ beam was accelerated by the 930 cyclotron at 150 MeV and transported to the experimental area. Figure 1 shows the experimental setup of thereaction target and gas degrader. The 17.6-mg/cm2 thick CD2 target was bombarded with the 15 N beam,and 16 N was produced from the d (15 N, 16 N)p reaction.
A Faraday cup and a sheet of aluminum oxide (Al2 O3 )were installed in the gas degrader to monitor the beam
current and its spot image, respectively. The Faraday
cup was also used to prevent the gas buffer cell from irradiation by the unreacted 15 N beam. The geometricalconfiguration of the collimators was chosen to give anangular range of 2.5◦ –3.0◦ . This angle was chosen bytaking into account the following three factors. 1) The
ratio of the production yield of 16 N to the amount of
the unreacted 15 N beam. 2) The measured production
rate of 16 N as a function of the emission angle normalized by the current of the primary 15 N beam, as shownin Fig. 2. 3) The typical current of the primary 15 N
beam was 10 nA; thus, the yield of secondary 16 N was
expected to be about 104 counts per second in the gas
buffer cell. The gas degrader was filled with argon gas,
and the pressure was regulated using a mass-flow controller.2) The degraded and collimated 16 N particles
entered the gas buffer cell.
Figure 3 shows a schematic view of the gas buffer
cell. The gas cell was filled with neon gas at a pressureof 170 Torr and was equipped with a DC electrode assembly, which consisted of 33 thin aluminum discs witha 5 cm bore. The gap between the discs was 1 cm andthe discs were connected by a 300 kΩ resister. The end
electrode was connected to the chamber by a 33 MΩ
resister. By applying a high voltage between the entrance of the electrode element and the chamber, aDC electric field was generated to transport the ionsin the downstream direction. The applied voltage ofthe electrodes was 450 V, which corresponds to a DC
electric field of 5 V/cm. By utilizing the β decay of
16
N, the positions of ions in the cell were measured∗1∗2

Department of Physics, Rikkyo University
Department of Physics, Tokyo Institute of Technology~ 512 mm

CD2
15

16

Argon Gas
15

N

150 MeV
CollimatorN

Faraday Cup

Gas CellN
Al2O3

Collimator

Fig. 1. Experimental setup of the reaction target and gas
degrader. The secondary 16 N beam, which is produced
from the d (15 N, 16 N)p reaction, were degraded in theargon gas. The geometrical configuration of the twocollimators was chosen to give an angular range of
2.5◦ –3.0◦ . The unreacted 15 N particles were stopped
by the Faraday cup. The effective length of the gas degrader was about 512 mm. The typical pressure of thegas was about 130 Torr.

Fig. 2. Production rate of 16 N normalized by the currentof the 15 N beam as a function of the emission angle.

using a two-layered plastic-scintillator beta telescope,
which was located beside the cell.3) The typical resolution of the telescope was 8 cm (FWHM). From thedecay-time spectrum, the purity of 16 N was about 40%.
By comparing the measurements with and without
the DC electric field, difference of about 1% in the16
N distribution was observed. However this result is
insufficiently accurate to enable quantitative comparison with calculated results; thus, further development
is required such as by improving statistics, purity, position resolution, applied voltage and moving efficiency.
References- 145 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Electrodesβ16N
Gas Cellβ Telescope

Fig. 3. Schematic view of the gas buffer cell. The incident
16
N ions are stopped by the neon gas and then transferred by the DC electric field toward the downstreamof the cell. β rays from 16 N were detected to obtain theposition distribution of 16 N.

1) I. I. Rabi et al.: Phys. Rev. 55, 526 (1939).
2) K. Shimada et al.: RIKEN Accel. Prog. Rep. 39, 156(2006).
3) H. Miyoshi et al.: RIKEN Accel. Prog. Rep. 37, 171(2004).

2- 146 -

RIKEN Accel. Prog. Rep. 40 (2007)

Improvement of slow RI beam transport using carbon-OPIG
A. Takamine∗1 , M. Wada, Y. Ishida, T. Nakamura, K. Okada∗2 , Y. Yamazaki, Y. Kanai, T. M. Kojima,
A. Yoshida, T. Kubo, S. Ohtani∗3 , K. Noda∗4 , I. Katayama∗5 , V. Lioubimov∗6 , H. A. Schuessler∗6 ,V. Varentsov∗7 , and H. Wollnik∗8[slow RI beams, rf-carpet ion guide, carbon-OPIG]
A universal facility for slow radioactive ion beams(SLOWRI) is being developed1) as part of the RI Beam
Factory. SLOWRI aims at providing universal slow RI
beams of high purity and small emittance by slowing
down and cooling energetic RI ions using an rf ion
guide. We achieved a high overall eﬃciency of ∼5%
and a maximum intensity of ∼24 kcps in slow beams(∼eV)2) for ∼100A MeV 8 Li ions from the projectile
fragment separator RIPS.
Although we succeeded in trapping several hundredsof 7,10 Be+ ions in the linear trap and measured the isotope shift of 7,10 Be+ for the 2s 2 S1/2 -2p 2 P3/2 transition3) , the intensity of the slow 10 Be+ ions was only a
few tens cps due to a problem in the SPIG4) . When weused the two-segmented SPIG made of metallic rods,
slow 8 Li+ ions was transported only at a low He buﬀer
gas pressure of 13 mbar, although a higher pressure ofabout 133 mbar was the best condition to extract slow
8 +Li ions up to the short, about 10 cm long, SPIG.
Even at such a low pressure, a relatively high dc voltage of 100 V between the 10-cm-long upstream section
and the 50-cm-long downstream section was required
to transport slow RI ions. These problems are considered to be due to the ﬁnding that the presence ofresidual He gas (1∼10−4 mbar) in the upstream regionof the SPIG blocks the stream of slow ions in the SPIG.

cross section

Fig. 1. Schematic drawing of OPIG. The OPIG consists ofeight 1-mm-dimeter rods made of CFRP with an innerdiameter of 2.5 mm.
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Graduate School of Arts and Sciences, University of Tokyo
Department of Physics, Sophia University
Institute for Laser Science, University of ElectroCommunications
National Institute for Radiological Science
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Association, KEK
Department of Physics, Texas A&M University
Kholopin Radium Institute
II. Physikalisches Institute, Justus-Liebig-Universitaet

rf carpet

gas cell

RIPS
SSD

OPIG
cylindricaldc electrodes

wedge
degraderFig. 2. Schematic of experimental setup. Ions thermalized
in the gas cell ﬁlled with 26 or 133 mbar of He are transported by dc ﬁelds and rf ﬁelds to the exit nozzle andtransported under carbon-OPIG. The intensity of slow
8 +Li beams was measured by counting delayed alphaparticles by SSD behind the OPIG.

A solution to provide continuous force to the ion
stream in such a buﬀer gas environment is to provide
a continuous dc electric ﬁeld in the axial direction. For
this purpose, we searched for a resistive material to be
used as the rods of the SPIG. We originally constructed
a new beam guide, carbon-OPIG (Fig. 1), which ismade of carbon-ﬁber-reinforced plastic (CFRP), andnow has an octopole conﬁguration due to a practicalreason. The rod has about 60 Ω resistance when the
diameter is 1 mm and the length is 60 cm, and therefore, it is quite easy to provide an axial dc potential
gradient of 2 V for a 60 cm length with a reasonably
low electric current of 0.2 A.
In a preliminary test experiment using 100A MeV
8
Li beams from RIPS, we conﬁrmed that intensitiesof 2.2 kcps and 2.7 kcps of slow 8 Li+ ions that weretransported up to the end of the carbon-OPIG at Hepressures of 26 mbar and 133 mbar in the gas cell, respectively, were obtained. Although the operation parameters were not optimized, and thus far it has beendiﬃcult to evaluate the absolute eﬃciency of the newcarbon-OPIG, this performance should be suﬃcient for
precise measurements of the hyperﬁne structure andisotope shifts of stored 7,11 Be+ ions in a trap, which is
our next goal.
References
1) M. Wada et al.: Nucl. Instrum. Methods Phys. Res. B
204, 570 (2003).
2) A. Takamine et al.: Rev. Sci. Instrum. 76, 103503(2005).
3) T. Nakamura et al.: Phys. Rev. A 74, 052503 (2006).
4) A. Takamine et al.: RIKEN Accel. Prog. Rep. 39,
157(2006).

- 147 -

1

RIKENRIKENAccel.
Accel. Prog. Rep.
Rep. 40 (2007)

Status of Rare RI–Ring project
Y. Yamaguchi, A. Ozawa,∗1 I. Arai,∗1 T. Fujinawa, N. Fukunishi, A. Goto, T. Kikuchi,∗2 T. Ohnishi, T.
Ohtsubo,∗4 H. Sakurai, T. Suzuki,∗3 M. Wakasugi, T. Yamaguchi,∗3 Y. Yasuda,∗1 and Y. Yano
To measure precisely the mass of radioisotopes (RIs)
including the r–process region, we are considering adevice similar to a storage ring. Arbitrary RIs are
generated in RIBF by projectile fragmentation and/or
uranium fission, and they are identified using the BigRIPS1) fragment separator. After their identification
at the BigRIPS, they are injected into the storage ringindividually. Then their flight time (revolution time)is measured at the storage ring.a)
The measurement is based on the following principles. According to the cyclotron principle, revolution
time is the inverse of cyclotron frequency. In addition,
when an isochronous magnetic field is formed, the revolution time (T0 ) is expressed as
T0 = 2πm0 1
m0 1
γ0 = 2π
,
q B
q B0

(1)

where B0 is a uniform magnetic
p field, γ0 is the relativistic factor defined as γ0 = 1/ (1 − β02 ) and β0 = v/c.
The isochronous magnetic field at specific momentum
spaces inside the storage ring are calibrated with 10−6
or less accuracy using an already known stable nucleus.
In such an isochronous ring, we measure the revolution
time of an unknown mass nucleus, which has the almost same m/q value as that of the stable nucleus. In
such nuclei with slightly different mass–to–charge ratios (i.e., m1 /q=m0 /q+ ∆(m0 /q)), isochronism is nolonger fulfilled. In this case, m1 /q can be expressed assm1
m0 T1 γ0m0 T1
1 − β12==,(2)
q
q T0 γ1
q T0 1 − ( TT1 β1 )20where T1 is p
the revolution time for nuclei with m1 /qand γ1 = 1/ 1 − β12 . To evaluate the mass of nuclei
with non–isochronism, correction for the velocity β1
is required. The relative differential value of m1 /q isexpressed asδ(m1 /q)δ(m0 /q) δ(T1 /T0 )
δβ1
=
+
+k
,
m1 /q
m0 /q
T1 /T0
β1

(3)

where
k=−

β12
β12
T1
+ ( )2.
2
1 − β1
T0 1 − (T1 /T0 )2 β12(4)When we require an accuracy on the order of 10−6 for
1% difference in mass, we must measure T1 with 10−6
∗1
∗2
∗3
∗4
a)

Institute of Physics, University of Tsukuba
Department of Electrical and Electronic Engineering, Utsunomiya University
Department of Physics, Niigata University
Department of Physics, Saitama University
For details please refer to ref. 2.

Fig. 1. Floor arrangement of isochronous ring and long injection line according to the design.

accuracy and β1 with 10−4 accuracy independently.
Figure 1 shows the floor arrangement of theisochronous ring and a long injection line according
to the design. The long injection line of 200 m isnecessary to measure β with the required accuracy.
It is extended from the BigRIPS to the isochronous
ring and gives more than 1 µs flight time for nuclei
of 200 MeV/nucleon. Because the time resolution ofa typical plastic scintillator is better than an order of
100 ps, the long injection line enables the measurementof the velocity of nuclei with 10−4 accuracy. To determine the arrangement of the magnets of the long injection line, we are presently examining using GIOS3)
and/or COSY INFINITY4) . Incidentally, we have already kept those magnets and power supplies, and began to check their status.
Concerning the injection method, we adopt the individual injection method5) , which is highly efficient forthe stacking of rare nuclei. A certain nucleus is identified using BigRIPS, and the trigger signal must betransmitted to a kicker system faster than the nucleus
itself. The long injection line enables this relation. Under the present conditions, it takes about 1350 ns at a
distance of 230 m (from the trigger point to the kicker
magnet) in the case of a nucleus of 200 MeV/nucleon.
On the other hand, the transmission time of the trigger signal is about 1300 ns from the signal start to astate ready for injection at the kicker system. Thatis, the above conditions satisfy the individual injection- 148 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

method.
The nucleus is brought onto the closed orbit of theisochronous ring using the combination of the septum
magnet and kicker system. After it turns about 3000
times in high–precision magnetic field regions at theisochronous ring of about 56 m in circumference, it isejected from the isochronous ring, then we can measure its revolution time with 10−6 accuracy. After thatthe ejected particle is identified again using some detectors. The ejection scheme is simply inverse of theinjection scheme (see Fig. 1).
To decide the rough specifications of the septum
magnet, the kicker system and the isochronous ringitself, we performed calculation using a transfer matrix method in hard-edge approximation. In the following estimations, the beam Bρ is assumed to be
6.43 Tm. This Bρ value corresponds to A/Z=3 in
200 MeV/nucleon.

kicker system. In relation to the transmission time of
the trigger signal, the response time of power supply
for the kicker system is a crucial issue. Because the response time of power supply accounts for about half ofthe transmission time of the trigger signal. A technicalimprovement that decreases the response time of power
supply as much as possible is needed. The kicker system must generate a high magnetic field with rapid riseand fall times, and a uniform flattop for efficient injection and ejection must be made. Because the injectednucleus passes the kicker system 330 ns after injection,
the magnetic field strength should be completely adjusted to 0 T at that time. Furthermore, the injectednucleus should be ejected from the isochronous ringusing the same kicker system about 1 ms (330 ns/turnx 3000 turns) later. Although the specifications for the
kicker system can be technically viable, we should empirically confirm them using a new model of the kicker
system as soon as possible.

Table 1. Specifications of isochronous ring
Table 3. Specifications of kicker system——RING——
Sector number
Circumference

6
56.13 m——SECTOR MAGNET——
Bending angle
Rotation angle
Magnetic pole length
Straight section length
Radius of curvature
Magnetic strength

1.047 rad0.155 rad4.5 m
4.855 m4.297 m
1.5 T

The isochronous ring specifications are summarizedin Table 1. We calculated the rotation angle for forming an isochronous magnetic field in the first order.
More higher–order isochronous magnetic fields will be
adjusted with trim coils.
Under this condition, we calculated TUNE values
and TWISS parameters using the MAD program6) .
The horizontal TUNE value is 1.26 and the vertical
TUNE value is 0.79. The phase advance between the
septum magnet and the kicker system is about 3π/2
(see Fig. 1). Regarding device spaces, each septum for
injection and ejection does not interfere with each orbit
of injection and ejection.
The septum magnet specifications are shown in Table 2. The septum magnet will be operated as a DC
magnet. The magnetomotive force is about 30000 AT.
Table 2. Specifications of septum magnet
Bending angle
Radius of curvature
Magnetic strength

30 deg.
8.573 m0.75 TThe kicker system specifications are summarized inTable 3. A traveling wave type will be used for this2

- 149 -

Kick angle
Total core length
Aperture
Rise time
Magnetic strength
Characteristic impedance
Current
PFN voltage
Total number of unit kicker
Kick angle per unit kicker
Cell number per unit kicker
Inductance per unit cell
Capacitance per unit cell29.24 mrad
2.4 m
hight; 0.05 m, width; 0.2 m
130 ns
0.079 T12.5 Ω
3120 A78 kV
12
2.437 mrad
8
126 µH
800 pF

We continuing our calculations of the beam optics
for the long injection line and the isochronous ring,
and we are going to determine the specifications of
the injection and the ejection scheme devices in detail.
Moreover, to realize a magnetic field of the isochronous
ring with 10−6 or less accuracy, we must concentrateon the design of its magnets using TOSCA.
References
1) T. Kubo: Nucl. Instrum. Methods Phys. Res. B 204,
97 (2003).
2) T. Yamaguchi et al.: Proc. of 6th International Conf.
on Nucl. Phys. at Storage Rings, (STORI’05).
3) H. Wollnik et al.: Nucl. Instrum. Methods Phys. Res.
A 258, 408 (1987).
4) M. Benz: Nucl. Instrum. Methods Phys. Res. A 298,473 (1990).
5) I. Meshkov et al.: Nucl. Instrum. Methods Phys. Res.
A 523, 262 (2004).
6) H. Grote et al.: CERN SL 90-13 (AP), (1996).

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4040 (2007)(2007)A multireflection time-of-flight mass spectrometer using cryogenic
linear ion trap for injection
Yoshihisa Ishida, Michiharu Wada, Yasunori Yamazaki, and Hermann Wollnik∗1
We have developed a multireflection time-of-flightmass spectrometer (MRTOF)1) and a linear ion trap
for the precise mass measurement of short-lived nuclei, which will be provided at the slow RI-beam facility (SLOWRI) of RIKEN-RIBF.2) Bunched slow ionsfrom SLOWRI will be transferred to the trap to becompressed in phase space. Subsequently, they will be
injected into the MRTOF, which consists of two coaxially arranged ion mirrors. Ions inside the MRTOF
will move back and forth repeatedly between the ion
mirrors in an energy-isochronous manner.
In a previous report,3) a mass resolving power,m/∆m, of more than 100,000 was reported. This resolving power is sufficient for studying the global properties of the nuclear structure and for probing theoretical models. However, further system improvements aredesirable because the small yield in the region far fromβ stability limits the number of events. Furthermore,
it would be useful to separate the ions of nuclei in the
ground state from those in the isomeric state using themass spectrometer for nuclear decay studies.
To improve the resolving power of the system, theion trap was cooled using a cryogenic refrigerator. This
reduces not only the spacial distribution of the ion but
also the average ion velocity in the trap. It is expectedthat short ion pulses will be extracted from the trap.
The ion trap was connected to the cryogenic head bysilver-coated copper wires to reduce the transmission of
acoustic noise from the cryogenic head to the trap. A
heat shield of multilayer aluminum-coated Mylar films
was placed inside a vacuum chamber. He buffer gas
was introduced into the trap to cool the trapped ionsby the buffer gas cooling. The temperature of the trap
measured using a silicon diode thermometer was about
80 K.
Figure 1 shows a mass spectrum of the CO-N2 mass
doublet after a flight time of ≈7 ms. A mass resolving
power of 200,000 has been achieved in this spectrum.
The time width of the extracted ion pulse from the ion
trap is 4 ns, which is 20% less than that from the ion
trap at room temperature. It is expected that one of
the components for the width will be reduced by thecooling effect, which is the so-called turn-around time∆t = 2m∆v0 /qE, where m, ∆v0 , q, and E are mass,
initial velocity difference in the direction of extraction,
charge of the ion, and strength of the extracting electric field in the trap, respectively. This time width
depends on the kinetic energies of the ions in the trap.
The present results indicate that other components forthe width contribute as much as the turn-around time.
∗1

To investigate the impurity ions in the trap, we
measured a wide range of masses in the single-path
TOF mode. A comparison of the mass spectra withand without cooling the trap is shown in Fig. 2. In
both measurements, the sample gas pressure in theion source and the electron current of the source of∼500 pA were held constant. The sample gas pressurein the source was estimated to be ∼10−3 Torr. The
most remarkable difference between the spectra withand without cooling the trap is the 10 times more intense ion beam at mass 28. Also, the disappearanceof the peaks at masses 18 and 19, which are derived
from water molecules was observed. There are also unchanged results such peaks at mass 29. It is thoughtthat the components of this peak are the isotopes ofthe sample, such as 14 N15 N+ and 13 C16 O+ , and protonated molecules, such as COH+ and N2 H+ . The
natural abundances of 13 C16 O+ and 14 N15 N+ are 1%
and 0.7%, respectively. In the case of cooling the trap,
the ratio of mass 28 to 29 is 2.3%, which is comparable
to the natural abundance. Therefore, it is found thatthe production of unwanted molecules was suppressedby cooling the trap.
The relative intensity of the ions as a function of timeof flight is shown in Fig. 3. Even after 10 ms of ion
flight, a transmission efficiency of about 50% has beenachieved by cooling the trap. Although the pressure in
the chamber of the trap became lower due to the adsorption of water molecules on the cryogenic head, thepressure of the chamber of the MRTOF remained almost constant. This suggests that the improvement intransmission efficiency is attributed to the small transverse emittance of the ion beam extracted from thetrap.
References
1) Y. Ishida, M. Wada, and H. Wollnik: Nucl. Instrum.
Methods Phys. Res. B 241, 983 (2005).
2) M. Wada et al.: Nucl. Instrum. Methods Phys. Res. B
204, 570 (2003).
3) Y. Ishida, M. Wada, Y. Yamazaki, and H. Wollnik:
RIKEN Accel. Prog. Rep. 39, 148 (2006).

University Giessen- 150 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 1. Mass spectrum of CO-N2 mass doublet after flighttime of ≈7 ms.

Fig. 3. Recorded ion intensity as function of ion flight time
relative to intensity after one pass. The dashed lines
are guides for the eyes.

Fig. 2. Comparison of mass spectra (a) with and (b) without cooling of trap.

2- 151 -

RIKEN Accel. Prog. Rep. 40 (2007)

Calibration Test of Space Radiation Measurement Instruments
T. Komiyama,*1 H. Matsumoto,*1 Y. Sasaki, *1 H. Kato, and T. Goka*1
1. Introduction
Some accidents involving satellites have happened withirreversible damage since a few years ago. For example, anelectrostatic discharge in a solar panel system and an upsetof an advanced microprocessor have occurred. Because thespace radiation environment is a major source of these
accidents, a space radiation environment monitoring systemshould be implemented on a satellite. In addition, an
estimation of the space radiation environment has become
increasingly important in the satellite design phase. Ourgroup has accumulated data on the space radiation
environment since 1987. On the basis of these data, aradiation model has been developed, which will be
proposed as an ISO standard.
Now, we are developing a space radiation measurement
instrument for the JASON-2 satellite, which is being
developed by the Centere National D’etudes Spatiales(CNES), the French space agency, and will be launched in2008. The monitoring instrument called the “Light Particle
Telescope” (LPT) was calibrated for the Proto-Flight Model(PFM) using RIKEN Ring Cyclotron in 2006.

We have conducted energy calibration tests on depositedenergy for APS-B using 210MeV protons. Moreover, wehave confirmed APS-B can identify incident particle species
using fragmented particles derived from the collision of
95MeV/n 40Ar particles with an aluminum target, such as
protons, deuterons, tritons, 3He, and 4He with energies in
the range of 0-90MeV/n.
Figure 1 shows typical scatter plots of energies depositedin the first SSD and the second and third SSDs we obtainedin the test for APS-B using fragmented particle irradiation.
The sensor was confirmed to be able to identify protons,
deuterons, tritons, 3He and 4He.
4. Future Plans
We will analyze the data we obtained in these calibration
tests and perform several environment tests for LPT to be
integrated to the JASON-2 satellite.
In addition, we are developing space radiation
measurement instruments for GOSAT, a Japanese satellite.
We plan to perform calibration tests of those instruments
using RIKEN Ring Cyclotron in 2007.

Energy deposited in the 1st SSD(ADC channel number)

2. Description of LPT 1) 2)
LPT is composed of two units, which are the electric unit
LPT-E and the sensor unit LPT-S. LPT-E provides anelectrical interface to the Jason-2 satellite system. LPT-S
consists of four sensors, ELS-A, ELS-B, APS-A, and
APS-B. The expected measurement range of each sensor isshown in Table 1.
ELS-A, APS-A, and APS-B consist of a stack of three orfour silicon semiconductor detectors (SSDs), and ELS-B
consists of one SSD and a crystal of Ce-added Gd2SiO5(GSO) scintillator. Each sensor can identify particle species(e.g.; electron, proton, and 4He) using energy deposited in
the first SSD, assuming that there are more electrons thanprotons or other particles on the orbit of the JASON-2
satellite. In addition, each sensor can measure the energy ofparticles by combining energies deposited in the first SSD
and in the other SSDs.

APS-B

He

4

He

t
protond

Energy deposited in the 2nd and 3rd SSD(ADC channel number)Table 1 Measurement Range of LPT sensors
Sensors
ELS-A
ELS-B
APS-A

3

Figure 1 Typical scatter plots of APS-B using fragmentation
particles derived from the collision of 95MeV/n 40Ar
particles with an aluminum target (18mm thick)Measurement Range
Electron 0.03 – 1.3MeV
Electron 0.28 – 20MeV
Proton 0.4 – 37MeV
4
He 0.75 – 40MeV/n
Proton 1.5-250MeV
4
He 2.5-100MeV/n

References
1) H. Matsumoto and T. Goka: Technical Report of theInstitute of Electronics, Information and Communication
Engineers, Vol.101 No.157, 83-87 (2001)
2) T. Komiyama, H. Matsumoto and T. Goka: Proceedingsof the 2006 IEICE General Conference, BS-6-21 (2006

3. Calibration Test
*1 Japan Aerospace Exploration Agency (JAXA)Space Environment Measurement Group- 152 -

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

High-Resolution Beam Line for SHARAQ Spectrometer
T. Kawabata,∗1 T. Kubo, H. Sakai,∗2 S. Shimoura,∗1 and T. Uesaka∗1
The construction of the SHARAQ spectrometer wasstarted in 2005 by the Center for Nuclear Study1) . The
SHARAQ spectrometer is designed to achieve a highmomentum resolution of ∆p/p ∼ 1/15000 for charged
particles with a magnetic rigidity of Bρ = 6.8 Tm. The
SHARAQ spectrometer will be used for nuclear spectroscopic studies using radioactive-isotope (RI) beams
produced by the RI beam factory (RIBF) at RIKEN.
Since the RI beams have a variety of isospins, spins,
and internal energies, RI-beam-induced reactions are
expected to be useful tools for probing nuclear manybody systems.
Since the RI beams generally have a large emittance,
the dispersion matching technique2,3) must be introduced to perform high-resolution measurements. If
the dispersions of the SHARAQ spectrometer and its
beam line are properly “matched”, the missing-massresolution can be significantly improved better thanthe momentum spread of the RI beam.
Following the notation of the computer code
TRANSPORT4) , the horizontal position x and angleµ at the focal plane of the spectrometer are related tothose at the starting point of the beam line using thetransfer matrix elements of the spectrometer (sij ) andbeam line (bij ).
x =(s11 b11 + s12 b21 )x0+ (s11 b12 + s12 b22 )µ0+ (s11 b16 + s12 b26 + s16 )δ0 ,BigRIPS

10 m

F5
F4
F3

Fig. 1. Layout of SHARAQ spectrometer and highresolution beam line at RIBF.

(2)

s11 b16 + s12 b26 + s16 = 0,(3)

s21 b16 + s22 b26 + s26 = 0,(4)

the horizontal position and angle at the focal plane
are independent of the momentum spread of the beam.
Equations 3 and 4 are commonly called as the lateraland angular-dispersion matching conditions, respectively. It is necessary for high-resolution spectroscopy
with a secondary RI beam to construct a beam line satisfying these matching conditions. From Eqs. 3 and 4,∗2

F6

Production Target (F0)The x0 , µ0 , and δ0 are the horizontal position, angle,
and fractional momentum deviation from the central
trajectory (δ ≡ ∆p/p) at the starting point of thebeam line. When the coefficients of the momentumdependent terms in Eqs. 1 and 2 are zero as∗1

SHARAQ
Target(1)µ =(s21 b11 + s22 b21 )x0+ (s21 b12 + s22 b22 )µ0+ (s21 b16 + s22 b26 + s26 )δ0 .

SHARAQ
Beam line

Center for Nuclear Study, Graduate School of Science, University of Tokyo
Department of Physics, Graduate School of Science, University of Tokyoand the SHARAQ design values of sij , the dispersion
matching conditions for the beam-line transfer matrix
elements are determined to be b16 = ¡14.76 m andb26 = 4.79 rad.
The SHARAQ spectrometer will be installed in theE20 experimental room at RIBF, as shown in Fig. 1.
Since the RI beam emitted from the production target
at F0 is achromatically focused at F3 in the normal
beam transport procedure for the BigRIPS fragment
separator5) , we determined F3 to be the starting pointof the SHARAQ beam line.
The SHARAQ beam line shares magnetic elementswith the BigRIPS fragment separator up to F6. After
F6, the SHARAQ beam line branches from BigRIPS
and bends 60– toward the SHARAQ target. Since thelayout of the magnetic elements of the BigRIPS fragment separator has already been determined, the layout between the branching point and the target can be
optimized to satisfy the dispersion matching conditions- 153 -

1

RIKEN Accel. Prog. Rep. 40 (2007)(x|x) (= b11 )−1.00(x|θ) (= b12 )0.00(θ|x) (= b21 )0.21(θ|θ) (= b22 )−1.00(x|δ) (= b16 ) −14.76(θ|δ) (= b26 )
4.79(y|y) (= b33 )1.13(y|`) (= b34 )0.00(`|y) (= b43 )0.89(`|`) (= b44 )0.89
Table 1. Beam transfer matrix of SHARAQ beam line obtained by first-order ion optical calculation by GIOS.
The units for the lengths and angles are m and radian,respectively.

TargetSTQ-S3
SQ1
SQ2

F-S2

DQ
BM-S2
STQ-S2
BM-S1

F-S1

STQ-S1
STQ13
STQ12

F6

STQ11

F5

STQ10
STQ9
STQ8

F4

Y

F3

STQ7

X

Fig. 2. Envelopes of dispersive beam transport from F3
to SHARAQ target in horizontal (right) and vertical(left) planes. Trajectories are drawn for particles withx0 = ±3 mm, y0 = ±3 mm, θ0 = ±10 and 0 mr,`0 = ±30 and 0 mr, and δ0 = ±0.3%.

using the computer code GIOS6) .
One realistic solution for the dispersive beam transport is shown in Fig. 2. Two 30– bending magnets(BM) are used with several quadrupole magnets forthe beam transport from F6 to the SHARAQ target.
Although most of the quadrupole magnets are superconducting triplet quadrupole magnets (STQ) with awarm bore radius of 12 cm7) , the doublet (DQ) andsinglet (SQ) quadrupole magnets are normal conducting magnets. To save construction cost, PQ2 and PQ3magnets that were used for the SMART spectrographwill be utilized for the DQ magnets. Additionally, theexisting 400-mm and 500-mm quadrupole magnets will
be employed for the SQ1 and SQ2 magnets. The DQ
and SQ magnets are located between BM-S2 and STQS3. The maximum magnetic rigidity of the beam lineis 8.5 Tm, which is limited by the maximum field gradient of the DQ magnets.
The magnetic-field gradients for the several couples
of STQs are constrained to be symmetric. Namely,
the field gradients of the three quadrupole magnetsof STQ9 are equal to those of STQ12. Similarly, thefield gradients of STQ10 and STQ13 are equal to thoseof STQ11 and STQ-S1, respectively. This symmetricconstraint for the field gradients is helpful to simplify
beam-line tuning and to minimize higher order aberration.
The beam is focused both horizontally and vertically2- 154 -

at SF-2 between SQ1 and SQ2 in the last straight section after BM-S2. At this point, the horizontal size ofthe beam envelope is large, whereas the vertical size isrelatively small. The horizontal beam size is predominated by the momentum spread of the beam due toa large dispersion of 21 m. Thus, SQs can change thecorrelation between the momentum and the horizontal angle of the beam trajectory, which is presented by
the b26 term in the transfer matrix, whereas the otherion optical properties such as dispersion are nearly unchanged. The b16 term is easily changed by tuning
STQ-S3. Thus, the double focusing point between SQ1and SQ2 in the last straight section is useful for realizing the dispersion matching conditions.
The transfer matrix of the SHARAQ beam line obtained by the first-order ion optical calculation is tabulated in Table 1. The dispersion matching conditions
are successfully satisfied, whereas the horizontal andvertical magnifications are almost unity. The off diagonal terms of b21 and b43 are maintained small to
reduce the angular spread caused by x0 and y0 .
In this calculation, only the first-order effects aretaken into account, however, the higher-order aberration is not negligible since the secondary RI beams
have a large emittance. The hexapole and octupole
magnets are useful for correcting such higher-order effects. To optimize the layout of these multipole magnets and their field strengths, it is necessary to perform
higher-order ion optical calculation. This higher-order
calculation is still in progress, and the calculation results will be reported elsewhere soon.
References
1) T. Uesaka et al.: in this report.
2) B. L. Cohen: Rev. Sci. Instr. 30, 415 (1959).
3) T. Wakasa et al.: Nucl. Instrum. Methods A 482, 79(2002), and references therein.
4) K. L. Brown et al.: SLAC Report No. 91 Rev. 1, 1974
(unpublished).
5) T. Kubo: Nucl. Instrum. Methods B 204, 97 (2003).
6) H. Wollnik et al.: Ion-optics code GIOS, University of
Giessen, Germany.
7) K. Kusaka et al.: IEEE Trans. Appl. Supercond. 14,
310 (2004).

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)

High-resolution SHARAQ spectrometer
T. Uesaka,∗1 S. Shimoura,∗1 H. Sakai,∗2 T. Kawabata,∗1 A. Saito,∗2 K. Nakanishi,∗1 Y. Sasamoto,∗1 T. Kubo,∗3
G. P. A. Berg,∗4 S. Kubono,∗1 E. Ideguchi,∗1 and H. Yamaguchi∗11Overview

The SHARAQ spectrometer is a high-resolution
magnetic spectrometer designed for radioactive isotope (RI) beam experiments at the RI Beam Factory(RIBF). It can be used to analyze particles with a magnetic rigidity of 1.8–6.8 Tm, corresponding to an energy of 40–440 MeV/A for A/Z = 2 particles. The
spectrometer is designed for momentum and angularresolutions of δp/p ∼1/15000 and δθ ∼ 1 mrad, respectively. The magnet system can rotate around its
target position in the range from −2◦ to 15◦ to allow0◦ and forward angle measurements. Figure 1 gives an
overview of the SHARAQ spectrometer.

Fig. 1. SHARAQ spectrometer.

RI beams, produced at the primary target positionof BigRIPS, are transported to the SHARAQ target
position through the BigRIPS beamline1) and a newly
constructed SHARAQ beamline2) . The beamline andthe spectrometer are fully dispersion-matched. Simultaneous lateral and angular dispersion matchings are
crucial to achieving the high spacial and angular resolving powers of the spectrometer in view of the large
intrinsic momentum spread of RI beams. The beamline can also operate in an achromatic mode to provide
a small beam spot at the target position for diagnostic and experimental purposes. The beamline will beequipped with tracking detectors3) both for beam tuning and for beam monitoring.
2

Configuration

The SHARAQ spectrometer consists of three
quadrupole and two dipole magnets.
The first quadrupole doublet (SDQ) consists of
two superconducting quadrupoles (Q1 and Q2) witha design adopted from the superconducting triplet
quadrupoles of BigRIPS4) . The modification is mainly
∗1
∗2
∗3
∗4

Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
RIKEN (the Institute for Physical and Chemical Research)
Department of Physics and Joint Institute for Nuclear Astrophysics, University of Notre Dame

made to the 240-mm-diameter of warm bore in theoriginal triplet quadrupoles: The warm bore of SDQ
is diamond shaped with a 340 mm (horizontal) ×
230 mm (vertical) opening to accept the horizontallyextended envelope of the reaction products. The following normal-conducting dipole (D1) and quadrupole(Q3) magnets are recycled from the decommissioned
spectrograph SMART. The D1 magnet, which wasused as a 60◦ bending magnet with a bending radius of
ρ = 2.4 m in SMART, is used as a 32.7◦ bending magnet with a bending radius of ρ = 4.4 m in SHARAQ.
Both entrance and exit axes to the magnet are titledby 13.7◦ in a horizontally focusing direction.
The second dipole magnet, D2, is a new magnet specially designed to achieve the spectrometer specifications. The D2 magnet is a 60◦ bending magnet witha pole gap of 200 mm. At the exit, an edge angle of30◦ is provided for horizontal focusing. This reduces
the distance from the D2 magnet to the focal plane.
Details of its design are described in Section 4.
The specifications of Q1, Q2, and Q3 and of D1 andD2 are listed in Tables 1 and 2, respectively. It should
be noted that the effective lengths of the quadrupoles
are dependent on the magnetic field strength and thus
the values in the table represent typical ones.
Table 1. Specifications of magnets Q1–3.

Bore [mm]Max. gradient [T/m]
Effective length [mm]Q1
Q2340W ×230H
14.1
14.1
530
1020

Q3
φ270
7.4
840

Table 2. Specifications of magnets D1 and D2.

Bending radius [m]Bending angle [deg]Gap [mm]Max. field strength [T]Weight [t]

3

D1
4.4
32.7
230
1.55
102

D2
4.4
60
200
1.55
∼280

Ion-optical calculation

First-order ion-optical calculations using GIOS7)
were performed to achieve the design specificationsof the spectrometer and to accommodate the existing magnets and other constraints. Q1 and Q2 fieldstrengths were optimized to match the beam envelops
to the acceptances of Q2 and Q3. At the same time,
the strength of Q3 was adjusted to achieve zero verticalmagnification (y|y). The vanishing vertical magnification is essential in obtaining the required vertical angular resolution. Results of the first-order ion-optical cal-- 155 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

400 mmculations are shown in Fig. 2. In the upper and lower
parts, particle trajectories in the vertical and horizontal planes are shown for ∆x = ±30 mm, ∆y = ±5 mm,∆a = ±1◦ , ∆b = ±3◦ , and ∆p/p = ±1%.
The ratio of the dispersion [(x|δ) = 5.86 m] and themagnification in the dispersive plane [(x|x) = 0.397] is
14.8 m, resulting in a resolving power of p/δp =14800
for a target spot of 1 mm in diameter. A large value of|(y|b)| = 2.3 m/rad and a vanishing vertical magnification of (y|y) = 0.0 leads to a high angular resolution of∆b <1 mrad in the vertical direction. The horizontal
angular resolution ∆a is also as small as 1 mrad. Other
first-order matrix elements can be found in Ref. 5. The
designed parameters of the SHARAQ spectrometer arepresented in Table 3.

D1

Q3

D3

800 mmQ1 Q2

19.3 mFig. 2. Results of the first-order ion-optical calculation.
Upper and lower panels represent particle trajectories
in the vertical and horizontal planes, respectively.

4

Since D2 is the largest magnet in SHARAQ providing 60◦ bending, its design is the most critical part in
the design of the spectrometer.
A pole width of 1400 mm is needed to provide agood field region of ±400 mm from the central orbit.
In addition, round fillets are introduced to both sidesof the pole pieces to achieve field homogeneity in thewide field range of 0.4–1.55 T. The radii of the fillets
are 180 mm at the low-momentum side and 200 mm at
the high-momentum side. Actual arcs of the fillets areapproximated by step functions with nine steps. Roseshims with a thickness of 1 mm are added on bothsides of the pole. Their lengths are 49 mm at the lowmomentum side and 44 mm at the high-momentum
side. Results of magnetic field calculations show thatthe field produced with the pole is as homogeneous as∆B/B ∼ 1–4×10−4 in the region of ±400 mm fromthe central orbit5,6) .
Excitation of the magnet up to B = 1.55 T requiresa magnetomotive force of ∼2.6×105 A·turns. Coils arewound using a hollow conductor with a square crosssection of 20×20 mm2 area and a water cooling channel of 14 mm diameter. The circumference of the coilwinding is about 14 m. The coil consists of five pancakes with 20 windings for each. The temperature increase is expected to be ∼20◦ C for pressure a drop of
5 atm.
5

Table 3. Design parameters of the SHARAQ spectrometer.
Dispersion (D) [m]Horizontal magnification (Mx )D/Mx [m]Resolving power (for image size of 1 mm)
Vertical magnification
Angular resolution
Vertical acceptance [mrad]
Horizontal acceptance [mrad]in dispersion matching modein achromatic beam line mode
Solid angle [msr]in dispersion matching modein achromatic beam line mode

5.86
0.40
14.8 m14800
0.0<1 mrad
±50
±17
±30
2.7
4.8

Ion optical calculations using COSY INFINITY8)
are also carried out to evaluate the effects of higherorder aberrations. It was found that major aberrations(x|aa) and (x|aaa) originate from the inhomogeneous
field distribution of Q1 and Q2 in the region of radiir > 12 cm. The entrance pole of D2 will have the shapeof a 3rd-order polynomial to minimize these aberrations. In this way, the higher-order aberrations can be
kept small enough to not effect the first order design.

2- 156 -

Design of magnet D2

Schedule

The SHARAQ spectrometer is scheduled to be operational in 2008. The construction of dipole magnet
D2 is expected to be finished in FY2006. During thefirst half of FY2007, all magnets including the rotatingstage will be installed in the experimental area E20 of
RIBF. After completing the installation, field mapping
measurements of the magnets will be made in the second half of FY2007. Design and construction of thebeamline elements and the focal plane detector system will be carried out in simultaneously in FY2007.
Testing will be conducted at the end of FY2007.
References
1) T. Kubo: Nucl. Instrum. Methods Phys. Res. B 204(2003) 97.
2) T. Kawabata et al:, RIKEN Accel. Prog. Rep. 39(2006).
3) A. Saito et al:, RIKEN Accel. Prog. Rep. 39 (2006).
4) K. Kusaka et al.: IEEE Trans. Appl. Supercond. 14(2004) 310.
5) T. Uesaka et al.: CNS Annual Report 2005.
6) G. P. Berg: “Design Study of a New Dipole Magnet
D2 for the SHARAQ Spectrometer”, unpublished.
7) H. Wollnik et al:, AIP Conf. Proc. 177 (1998) 74.
8) M. Berz et al: Phys. Rev. C 47 (1993) 537.

RIKEN Accel. Prog. Rep. 40 (2007)
RIKEN Accel. Prog. Rep. 40 (2007)

Developments of multiwire drift chambers for SHARAQ beamline
A. Saito,∗1 S. Shimoura,∗2 T. Kawabata,∗2 Y. Sasamoto,∗2 T. Uesaka,∗2 and H. Sakai∗1
We are developing beamline detectors that will be
used at the high-resolution beamline for the SHARAQ
spectrometer, which are now under construction at RI
Beam Factory (RIBF)1,2) . The spectrometer is designed to achieve a resolving power of p/δp ∼ 1.5 × 104
and an angular resolution better than 1 mrad forcharged particles with magnetic rigidity of 6.8 Tm
at the maximum. The beamline for the SHARAQ
spectrometer is designed to fulfill dispersion-matchingconditions when combined with the SHARAQ spectrometer3) . The simultaneous achievement of lateraldispersion matching and angular dispersion matchingconditions are crucially important in the use of the
SHARAQ spectrometer for RI beams, which necessarily accompany a large momentum spread. Details of
the dispersion-matched beamline is described in otherreports3) . A dispersion matching technique and/or the
event-by-event tagging of the beam momentum will be
introduced to compensate for the energy spread of the
RI beam. Figure 1 shows the calculated optics of dispersive beam transport. The event-by-event tagging
and tracking are needed at F3 for monitoring image
size and at the target position to measure the momentum vector of the RI beam. There are some requirements for the tracking detectors. The thicknessof the detectors should be as small as ∼10−4 of radiation length to reduce the effects of multiple scatteringin the detectors to ∼0.1 mrad. The efficiency should
be as large as possible even for light RI beams suchas 8 He at 300 A MeV. The position resolution is required to be less than 300 µm at FWHM. The maximum counting rate should be 1 MHz for the dispersive

Event-by-event
Tracking
Tuning + Actual DAQ

D-S1

STQ7

D-S2

STQ10
STQ9
STQ8

S2

Q-

S1

DQ
ST

Q-

}

STQ13
STQ12
STQ11

{

SQ

ST

Tune focus
Tracking
Tuning only

TargetSTQ-S3

D3

D5

D4

F4

beam transport.
In order to realize the performance described above,
low-pressure multiwire drift chambers (LP-MWDC’s)are being developed. A low-pressure operation ataround 10–20 kPa is needed to reduce multiple scattering in the detector to as small as 0.1 mrad. The
anode and potential wires are 12.5-µmφ Au-W and
75-µmφ Au-Cu, respectively. The size of one cell is
5×5 mm2 . The maximum counting rate of each cell is
104 –105 Hz for dispersive beam transport. The specifications are summarized in Table 1. The signals fromthe anode wires are amplified and discriminated by the
REPIC RPA-130 64-ch. preamplifier and discriminator card. The timing signals from RPA-130 are digitized by CAEN V1190A/B multi-hit TDC.
Table 1. Specifications of beamline detectors.

LP-MWDC<300 µm†>95%†∼0.1 mrad†∼1 MHz†12.5 µmφ
75 µmφ
5×5 mm2
2.4 mm2 µmt
i-C4 H10
10–20 kPa†

position resolution
efficiency
multiple scatteringcounting rate
anode wirepotential wire
cell size
anode-cathode pitch
cathodegas
gas pressure†
designed value.

20 µmφ75 µmφ
6×6 mm2
2.5 mm
1.5 µmt
i-C4 H10
10–20 kPa†

In addition, we are developing LP-MWDC withstripped cathodes. The structure of the detector isshown in Fig. 2. The anode and potential wires and theelectronics are the same as those for LP-MWDC described above. The cathodes are stripped with 2.5 mm
pitch and the signals are read out using the delay linesthat were developed for the PPAC4) . Since the latterreadout system has only four channels, the number ofchannels can be reduced. Their prototypes are now
being tested.

F6

Z

F3

5 mm

5 mm

Z

F5

Anode Y
2.5 mmStandart tuning
Event-by-event
Monitoring of image

5.0 mmCathode GND
Anode X

5.0 mmCathode Y

Fig. 1. Calculated optics of the dispersive beam transport.
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo

2.5 mmCathode X

Y∗2∼0.1 mrad†

F-S1

Parallel for X
Tracking
Tuning only

∗1

LP-MWDC withstripped cathodes

X

Fig. 2. Schematic view of LP-MWDC with stripped cathodes.

- 157 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 3. Low-pressure multiwire drift chamber.

Fig. 4. Low-pressure multiwire drift chamber with stripped
cathodes.

References
1) T. Uesaka et al.: Eur. Phys. J. A (RNB7 Conf. Proc.)in press.
2) T. Uesaka et al.: CNS Ann. Rep. 2005 (2006) 61.
3) T. Kawabata et al.: CNS Ann. Rep. 2005 (2006) 63.
4) H. Kumagai et al.: Nucl. Instrum. Meth. in Phys. Res.
A470 (2004) 562.

2

- 158 -

RIKENRIKENAccel.
Accel.Prog.
Prog.Rep.
Rep. 40
39(2007)(2006)

Preparation of self-supporting boron target
Y. Sasamoto,∗1 T. Kawabata,∗1 M. Hamagaki, I. Sugai,∗2 and Y. Takeda∗2
The 11 B nucleus attracts a broad interest from theviewpoint of nuclear cluster physics since a dilute-gaslike cluster state has been recently observed in 11 B1) .
For further clariﬁcation of the cluster structure of 11 B,
a precise measurement of the alpha inelastic scattering has been planned. For the precise measurements,
a self-supporting and high-quality 11 B target with athickness of about 500 µg/cm2 is needed. Althoughvapor deposition is widely used to prepare a thin boron
target, it is diﬃcult to prepare a suﬃciently thickenough self-supporting target by this method. The
pressing method is also useful for the preparation ofboron targets; however, the boron target prepared bythis method is thicker than 10 mg/cm2 . In the present
work, a 11 B target was prepared by sputtering withthe electron-beam-excited plasma (EBEP).

Boron tablet
45°

HeaterFig. 1. Schematic view of experimental setup. Electrons
are emitted from the cathode and accelerated by applying the acceleration voltage Va . Then, the electron
beam produces the argon plasma in region (3) and heats
an isotopically enriched boron tablet. The argon ions
extracted from the EBEP sputter the boron tablet. The
size of the target is ϕ40 mm × 5 mm.

A schematic view of the experimental setup for the
preparation of the boron ﬁlms is shown in Fig. 1. Electrons are emitted from the cathode and accelerated
by applying the acceleration voltage Va . Then, theelectron beam produces a high-density argon plasma
in region (3) and bombards an isotopically enrichedboron tablet. Heating of the boron tablet by the bombardment of the electron beam is necessary to apply
a negative bias voltage to the boron tablet. Althoughboron is an electrical insulator at room temperature, it∗1∗2Center for Nuclear Study, University of Tokyo
High Energy Accelerator Research Organization (KEK)

Table 1. Optimal deposition conditions in present work.
Discharge voltage (Vd )Discharge current (Id )Acceleration voltage (Va )Electron beam current (Ia )Target bias voltage (Vt )Ion current (It )Deposition rate
Substrate
Temperature of substrate
Distance between tablet
and substrate

45 V
10 A
100 V
4A
−200 V
0.4 A
0.07 nm/s
glass platewith NiCl2
200 ◦ C
4 cm

becomes a conductor around 1000 ◦ C. After the boron
tablet is heated suﬃciently, a negative bias voltage isapplied to the boron tablet. Then, the argon ions extracted from the EBEP sputter the boron tablet. In
the sputtering using the EBEP method, the electron
beam produces the argon plasma and heats the boron
tablet. Finally, the sputtered boron particles are deposited on a substrate.
To obtain a self-supporting target, a water-solublecompound is deposited on the substrate before thetablet is sputtered. After boron is deposited on thesubstrate, the substrate is placed in water. Since thewater-soluble compound dissolves in water, the boron
ﬁlm deposited on the substrate ﬂoats on water. The
ﬂoating boron ﬁlms are scooped up and self-supporting
boron ﬁlms are obtained. In the present study, NiCl2 isused as the water-soluble compound. Since large boron
ﬁlms do not have suﬃcient strength to support theirown weight, the ﬁlms are scooped up on a polyethylene
ﬁlm with a hole of 10 mm diameter. The details of theprocedure for the preparation of the boron target using
the EBEP method are described in Ref. 2.
For the preparation of self-supporting boron ﬁlms,
internal stress is an important matter. When a large
internal stress exists in the ﬁlms, the ﬁlms become
breakable. Since internal stress depends on the deposition conditions, the deposition condition should be
optimized. To ﬁnd the optimal deposition conditions,boron was deposited under various conditions. The deposition rate was changed depending on the argon ion
currents. The temperature of the substrate was controlled by a heater. The distance between the target
and the substrate was also changed. The optimal deposition conditions in the present work are summarized
Table 1.
The thickness of the obtained ﬁlms was determinedby measuring the energy loss of the alpha particles
in the ﬁlms. The energy of the alpha particles was- 159 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Thickness (µg/cm 2 )measured by a Si detector. The thickest ﬁlm obtainedin the present work is 100 µg/cm2 thick. The thickness
is smaller than our initial expectation. However, theplaned experiment for 11 B can be performed when another experimental condition is improved, i.e., beam
intensity is increased or lower statistics is accepted.
The uniformity of the ﬁlm thickness is also examined. Figure 2 shows the position dependence of the
thickness of the obtained boron ﬁlm in the horizontal
and vertical directions. The large variation in the vertical direction is caused by the variation in the distance
between the boron tablet and the substrate. Since thesubstrate is placed with an angle of about 45◦ against
the sputtering tablet (see Fig. 1), the distance between
the boron tablet and the substrate is gradually changedin the vertical direction. The diﬀerence in the distance
between the tablet and the substrate leads to the difference in the deposition rate. Therefore, the variationin the ﬁlm thickness with inclination was observed in
the vertical direction. This variation is not a serious
problem for the experiment because the beam spot size
is very small compared with the thickness variation.
The purity of the boron ﬁlms was analyzed by the

120

(a)

100

80
60
40
20
0

Thickness (µg/cm 2 )

-4

-2

2 4
Position (mm)

(b)

80
60
40
20
-4

-2

0

2 4
Position (mm)Fig. 2. Position dependence of thickness of obtained ﬁlm
in horizontal direction (upper ﬁgure) and vertical direction (lower ﬁgure).

2

6.5 %
1.2 %
1.9 %
less than 1 %electron probe microanalyzer (EPMA) method. In
the EPMA measurement, an electron beam was irradiated to a sample and the characteristic X-rays emitted
from the sample were detected. The EPMA measurement shows an unsatisfactory result in that the boron
ﬁlms are contaminated with carbon, nitrogen, oxygen,
and argon. The contaminating impurities in the ﬁlms
are summarized in Table 2. The boron ﬁlms contain
about 10 % contaminants, which is not acceptable forthe experiment. In a previous work using the EBEP
method2) , no impurities were detected in the EPMA
measurement. The possible origins of these impurities
are the carbon parts in the surrounding material, theresidual gases in the vacuum chamber, and the impurities in the boron tablet. It is expected that the surrounding material is not sputtered because the carbon
parts are surrounded by the insulator. The amountof impurities originating from the residual gases is expected to decrease when the ﬁlm is baked. A baked
ﬁlm was analyzed with the expectation of a decreasein the oxygen contamination originating from water;
however, the same amount of oxygen was found in the
baked ﬁlm. These impurities were not detected fromthe boron tablet in the EPMA measurement. The origins of these impurities are still unclear; therefore, further investigation is necessary.

1) T. Kawabata et al.: Phys. Rev. C 70, 034318 (2004).
2) S. Ozawa and M. Hamagaki: Vacuum 74, 417-421(2004).

1000carbonnitrogenoxygenargon

References

0120

Table 2. Contaminating impurities in boron ﬁlms. The
boron ﬁlms contain about 10 % contaminants.

- 160 -

RIKEN Accel. Prog. Rep. 40 (2007)

Development of solid hydrogen target for ESPRI
H. Takeda, Y. Matsuda,∗1 S. Ishimoto,∗2 T. Ohnishi, K. Ozeki,∗3 T. Suda, S. Suzuki∗2 and J. Zenihiro∗4
Proton elastic scattering at intermediate energies(200 – 400MeV) is one of the best probes for investigating the internal information of nuclei because of thelarge mean free path in the nuclear medium. With theaim of extracting the density distributions of shortlived radioactive isotopes (RI), we have carried out an
ESPRI (Elastic Scattering of Protons with RI beam)
project. The elastic scattering of RIs is measured byan inverse kinematics method. A solid hydrogen target (SHT) system has been developed for this purpose.
We have already succeeded in forming a windowless 3mm-thick SHT1) .
This year, we have developed 1-mm- and 5-mmthick SHTs with thin window ﬁlms to perform protonelastic-scattering experiments on 20 O and 9 C at HIMAC2) . The 1-mm-thick SHT was developed for the20
O experiment. A thin SHT was indispensable for the20
O measurements since the multiple scattering, energy loss and energy straggling inside the SHT madeit diﬃcult to distinguish the ground state from the ﬁrst
excited state of 20 O. On the other hand, a thick target
could be used for the 9 C measurement, since 9 C has
no bound excited states. The thick target enabled us
to obtain suﬃcient statistics even with a low-intensity
9
C beam. Since it was diﬃcult to form a 1-mm-thickwindowless SHT, we used thin 9µm aramid ﬁlms glued
onto both sides of the cell. The ﬂatness of the SHT isimportant in determining the cross sections of elastic scattering accurately. To prevent the thin window ﬁlms from swelling due to hydrogen gas, we used
an assembly developed to fabricate a windowless SHT(Fig. 1). Instead of using Teﬂon-coated stainless-steel
plates, we installed thermally isolated copper plates tocover the cell. The plates were pressed onto the cellusing stainless-steel bellows with 0.5 atm helium gas
inside. Pt-Co resistance thermometers were inserted
in the cell and the plate. The starting temperatures ofcryostatcopper cellaramid film

bellows
thermal insulator
copper plate

Fig. 1. Schematic view of the assembly to avoid the swellingof window films.
∗1
∗2
∗3
∗4

Department of Physics, Tohoku University
High Energy Accelerator Research Organization (KEK)
Cyclotron and Radioisotope Center, Tohoku University
Department of Physics, Kyoto University

Fig. 2. 1-mm- and 5-mm-thick SHTs covered with 9µm
aramid films are shown on the left and right sides, respectively. Some structures can be seen. See the text
for detail.

the cell and the plates were ∼5.4K and ∼60K, respectively. Hydrogen gas was stored in a 20L buﬀer tank at
50 ∼ 250 Torr and was introduced into the cell. At ﬁrst,
a constant ﬂow was maintained using a mass ﬂow controller, then the ﬂow was gradually decreased according to the decrease in the buﬀer tank pressure. It took
about 10 minutes until the ﬂow completely stopped.
We waited for several minutes until the cell temperature became stable. Then the plates were removed by
evacuating the helium gas in the bellows.
Figure 2 shows photographs of the SHTs used in
the HIMAC experiments. The left ﬁgure shows the 1mm-thick SHT used for the 20 O measurement, while
the right one shows the 5-mm-thick SHT used for 9 C
measurement. The SHTs were almost free of holes
when the copper plates were retracted. However, holes
formed within a few minutes at the center for bothcases, as can be seen in Fig. 2. The formation of theholes is not due to heat from the beam, since it occurred before the beam hit the SHTs. This was theﬁrst time that we observed such a phenomenon, andwe have no clear explanation for it at this moment.
We can also see a dark region above the hole of the
5-mm-thick SHT. On the basis of our experiences, thisseems to be a group of voids formed after the conﬁnement of the liquid hydrogen surrounded by the solid,
since the volume of the hydrogen shrank during the solidiﬁcation. To avoid this phenomenon, it is desirable
to form the crystal directly from hydrogen gas without passing through the liquid phase. Careful choicesof the initial conditions such as pressure and the hydrogen gas ﬂow from the inlet are necessary. It is also
important to achieve as low cell temperature as possible since the acceptable range of conditions becomes
broader. The shape of the cell should also be considered carefully.
References
1) T. Ohnishi et al.: RIKEN Acc. Prog. Rep. 38, 150 (2005).
2) S. Terashima et al.: in this RIKEN Acc. Prog. Rep.

- 161 -

1

RIKEN40 (2007)RIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 39(2006)Development of the recoil ion detector for SCRIT experiment†
K. Ishii1 , T. Emoto, Y. Furukawa2 , S. Ito, K. Kurita∗1 , A. Kuwajima2 , T. Suda, T. Tamae2 , M. Wakasugi, S.
Wang, and Y. Yano[electron scattering, RI, SCRIT]
We are developing a recoil ion detector for SCRIT(the Self-Conﬁning RI Target). SCRIT is used in anelectron scattering experiment method we are establishing. SCRIT is used to determine the behavior of
the charge density of RI. The method using SCRIT
involves the trapping of ions in electron beam potential and letting beam electrons to scatter the trapped
ions. Presently we are investigating ion trapping in
the electron beam passage using ions of a stable nucleus (i.e. Cs ions) at Kyoto University. Cs ions are
injected externally.
The trapping eﬃciency of ions is low. Thus, it isnecessary to conﬁrm that the electrons are scatteredby the target ions but not by other residual gas ions.
To this end, it is necessary to measure the coincidence
between recoiled ions and scattered electrons.
The problem in detect recoil ions is that the detector should be placed in a high-vacuum environment
and the energy of recoil ion is as low as 50keV. Therefore the choice of detectors is limited. We determine
a technical choice on the basis of the environment anddetector eﬃciency. Additionally, we should determine
the background level at which the recoil ion detector
should be placed.
We calculate ion transport as the ﬁrst step toward
recoil ion detector development. For an easy recoiled
ion detection, we change ion transport slightly. We
chose a microchannel plate(MCP) and Channeltron for
detection. The purpose of using the two types of detector is to examine the diﬀerence in eﬃciency of detecting
background particles.
The transportation of recoiled ions was calculated
and a prototype device was fabricated. The device isshown in ﬁgure 1. We install a deﬂector and an einzel

Fig. 2. Channeltron count[Hz] vs electron beam[mA]separately to change ion transport and improve acceptance. Furthermore, instead of placing detectors suchthat they face the recoil ion direction, we decided toutilize a secondary electron emitter foil, so that background particles do not hit the sensitive volume. The
two detectors were placed symmetrically with respect
to the secondary electron emitter foil to determine detection eﬃciency.
A large number of signals that originate from residual gas are detected. Some externally injected ionsare diﬀused into the recoil port directly. However,
we obtain interesting information on other backgroundparticles originates from synchrotron radiation. We
found that intensity of this background is proportional
to electron beam current, as shown in ﬁgure 2. The
counting rate is about 1kHz at 50mA electron beam
current.
The next step is to develop a method of decreasing the counting rate from background of residual gas
and improve the acceptance of recoiled ions. The main
existing problem is residual gas. It is necessary to remove inﬂuence of residual gas to establish the SCRIT
method. Our goal is to decrease the background level
to less than a few kHz to be able to measure the coincidence between recoiled ions with scattered electrons.
We decrease the number of background by deﬂecting
ions away from photons with a deﬂector, and installing
more slits. We need to optimize ion transport to improve the acceptance of recoiled ions.
References
1) T. Suda et al.: RIKEN Accel. Prog. Rep. 37, 81 (2004).
2) T. Suda et al.: RIKEN Accel. Prog. Rep. 38, 71 (2005).

Fig. 1. Schematic view of experimental setup∗1∗2

Rikkyo University
Tohoku University- 162 1

RIKEN
Prog. Rep.
Rep.4040 (2007)(2007)RIKEN Accel.
Accel. Prog.

New method of polarization reversal using 180-deg pulse nuclear
magnetic resonance
T. Kawahara,∗1 T. Wakui,∗2 T. Uesaka,∗3 and S. Sakaguchi∗3
1

Introduction

The polarized proton target for a RI beam experiment should be operated in a low magnetic field (0.01–
0.3 T) and at a high temperature (77–300 K) to detect a low–energy recoil proton. One possible method
to achieve the polarization is to make use of a population difference of electrons in Zeeman sublevels in
the photoexcited triplet state of aromatic molecules1) .
Because this population difference is independent of
temperature or magnetic field,a proton can be polarized in a low magnetic field of 0.3 T and at a hightemperature of 100 K, by transferring the populationdifference of electrons. The polarized proton target using the method has been successfully constructed andapplied to RI beam experiments2,3) .
In the measurement of polarization observables, it isindispensable to reverse the direction of polarization to
reduce systematic uncertainties. In the previous measurement3) , no efficient polarization reversal method
was available and polarization was built up in the opposite direction, which costs a time loss of more than anumerical value is suggested if possible. Surely, a new
method to flip the polarization axis is needed for more
efficient use of machine time. We have applied a pulse
NMR method for the purpose.
2

Pulse NMR method

In the pulse NMR method, the spin is flipped byapplying the transverse magnetic field B1 that is perpendicular to the static magnetic field B0 . Here, theflip angle of the spin can be written asµ = γI B1 ∆t,

∗2
∗3

3

Improvement to carry out method of 180deg pulse NMR

We improved the NMR coil as a first step.The spin
flip angle µ is directly related to the FID signal amplitude VFID , as VFID ∝ sin µ. VFID for the original NMR
coil, which is 10-turn of a 0.35-mmφ copper wire, isshown in the left panel of Fig. 1 as a function of the
RF pulse lebel of the transverse magnetic field B1. It
is clearly observed that the spin is rotated by only
90-deg(sin µ ∼ 1) even for the strongest B1 that islimited by a maximum output of a RF amplifier. Various combinations of wire diameter and turn number
were tried to produce a stronger B1 . Note that, notonly turn number but also wire diameter affects the B1
strength. This is because the wire diameter changes
the impedance of the coil and thus is related to matching between the coil and the RF circuit. Whenever a
new NMR coil was made, its impedance matching to
the circuit was adjusted using a tuner, which is madeof variable capacitances, at an appropriate frequency
that is determined by the magnetic field strength. Finally, a coil of 35-turns of a 0.35 mmφ copper wire
was found to be the best coil in the current conditions.
Using this NMR coil, we succeeded in rotating the polarization of a water sample by 180-deg. The result isshown in the right panel of Fig. 1.

(1)where γ1 = 2.68×108 s−1 T −1 is the gyromagnetic ratioof a proton, and ∆t is the pulse width. After turning
off the B1 pulse, the spin processes around the static
magnetic field B0 , which causes an induced current in
the NMR coil. The induced signal is called the “free induction decay” (FID) signal. Its amplitude, i.e., FID
amplitude, is proportional to the degree of polarization. For the reversal of the spin, the flip angle µ mustbe 180-deg. It can be easily understood that a flip
angle of 180-deg can be achieved by the long pulse duration ∆t and /or the strong perpendicular magnetic
field B1 . Long pulse duration, however, leads to a decrease in polarization due to the spin–lattice relaxation∗1

during the reversal.
To avoid the loss of polarization, we tried to makea stronger B1 field keeping the pulse duration as short
as a few a numerical value is suggested if possible. An
NMR coil was modified for this part .

Department of Physics, Toho University
Cyclotron and Radioisotope Center, Tohoku University
Center for Nuclear Study, Graduate School of Science, University of Tokyo

Fig. 1. FID signal amplitude. The left panel shows the FID
signal measured using an orignal NMR coil. The rightpanel shows the FID signal measured using the upgrade
NMR coilIn the next step, we optimized the RF pulse width.
Since spin relaxation is fast during the rotation procedure, a shorter pulse width is preferable. On the other
hand, the rotation angle can be smaller than 180-deg
when the pulse width is too short. The efficiency of- 163 -

1

RIKEN Accel. Prog. Rep. 40 (2007)
100

Polarization [arb. unit]

the polarization reversal was evaluated by measuring
the polarization loss in repeated reversals. The results
for the pulse widths between 1.0 µsec and 4.0 µsec are
shown in Fig 2. From the results, the pulse width was
optimized to 2.2 µsec.

50

2.2 µs

10 h

0

2005
2003

-50

-100
-10

-5

0

5

10

15

20

Time [hours]
Fig. 3. Time development of proton polarization. Closed
and open circles indicate data in 2005 and 2003, respectively. The polarization is reversed at T=0.

References
Fig. 2. The efficiency of polarization reversal is shown. The
polarization was reversed three times during the experiment. The RF pulse width was changed between
1.0 „sec and 4.0 „sec. An optimum pulse width was
found at ∆t = 2.2 „sec.

4

Results

We applied this polarization reversal technique tothe actual polarized proton target made of naphthalene doped with a small amount of pentacene. Since
the efficiency of the reversal depends on the line widthof the NMR spectrum, it then depends on different
materials. The result of the polarization measurement
during the p~ + 6 He scattering experiment2) is shownin Fig. 3. Closed circles denote the results taken in2005, where in our new technique was applied, where
as open circles represent data for the 2003 measurement. At t = 0 hour, the polarization was reversed inboth cases. It is found that the efficiency of the polarization reversal by the new technique is about 70%
using naphthalene.
5

Summary

Using the 180-deg pulse NMR method, we have succeeded in the reversal of the polarization direction.
The NMR coil was upgraded by inereasing the turnnumber 10 to 35 times. In addition, we optimized theRF pulse width to achieve high efficiency of the polarization reversal. The RF pulse width was determinedat 2.2 µsec. The new proton reversal methods was
actually applied during the p~ + 6 He scattering experiment. The efficiency of the polarization retversal was
about 70% using naphthalene, and the polarized timewas 2.2 µsec, which was dramatically shortened from
10 hours in the 2003 experiment3) .
-----

2

- 164 -

1) T. Wakui et al.; Nuclear Instruments and Methods inPhysics Research A 550 (2005) 521,
2) S. Sakaguchi et al.; RIKEN Accelerator Progress Report
vol. 40 (2006).
3) M. Hatano et al.; European Physical Journal A 25
(2005) 255.

RIKEN Accel. Prog. Rep. 40 (2007)

Scintillation ﬁber detector for momentum analysis
Y. Matsuda,∗1 T. Kobayashi,∗1 M. Itoh,∗2 K. Ozeki,∗2 T. Murakami,∗3 J. Zenihiro,∗3 Y. Iwao,∗3 T. Ichihara,
T. Suda, H. Otsu, H. Takeda, S. Terashima, Y. Watanabe, T. Ohnishi, K. Yoneda, and H. Sakaguchi∗4
In most RI beam experiments, the momentum of
the incident RI beam must be measured. At the
momentum-dispersive focal plane of the beam line,
position-sensitive gas detectors such as PPACs or MWPCs are often used. However, the eﬃciency of suchgas detectors tends to decrease at high beam rates.
There is also a risk of gas handling in a high vacuum, which sometimes causes a fatal problem. To
overcome these diﬃculties, we have developed a simple
one-dimensional scintillation ﬁber detector (SFD). We
have studied the performance using beams from twoaccelerators.
Figure 1 shows a schematic view of the SFD. The
SFD consists of sixty rows of scintillation ﬁbers, eachwith a cross section of 2 mm square. The eﬀective
area is 120 mm×50 mm. Scintillation light from eachﬁber is collected by a 64-channel PMT (Hamamatsu
H8500). The anode outputs are converted into LVDS
signals by four ASDs (GNomes Design GNA-180) andfed to TDCs. On the other hand, the dynode output
is ampliﬁed using a preampliﬁer, which uses the same
ASD chip,1) it is further ampliﬁed using a PM ampliﬁer, then fed to a charge ADC.
At ﬁrst, the eﬃciency of the SFD and its dependence
on the HV and beam intensity were studied at the HIMAC facility in the NIRS. The SFD was set perpendicular to the beam axis in the achromatic focal plane
and irradiated using a 390 MeV/nucleon 22 Ne primarybeam (a 300 MeV/nucleon 20 O secondary beam) withintensities of 2 × 106 (1 × 106 ) particles/pulse (ppp,
one pulse=1.2 sec) and 5 × 103 (4 × 103 ) ppp, respectively. The eﬃciency turned out to be indepen-

PM T

Cookiedent of beam intensity, and the maximum eﬃciency
obtained for a single-cluster event (C1) was 90% at the
HV plateau. The eﬃciency does not reach 100%, because the surface of each ﬁber is covered with PMMA
cladding with a ﬁnite thickness, which gives rise to
an insensitive area. With higher HV, the total eﬃciency reaches 100%, while the eﬃciency for C1 starts
to decrease because of crosstalk. Most crosstalk canbe eliminated by correlating the dynode output withthe anode outputs.
The loss of eﬃciency due to the insensitive areas
could be recovered by injecting ions obliquely. Thiseﬀect was examined at CYRIC at Tohoku University.
Elastically scattered protons obtained by bombarding
a 92.5 mg/cm2 carbon target with a 45 MeV proton beam were used to irradiate the SFD. By tilting the SFD, the eﬃciency for C1 was able to reachnearly 100% without complex analysis. For actual use
at a momentum-dispersive focal plane, beams would
be mostly injected obliquely when the SFD is placedalong the focal plane, because momentum-dispersive
focal planes are often tilted.
Finally, the SFD was installed along the tilted
momentum-dispersive focal plane of the SB course at
the HIMAC facility for testing. Figure 2 shows the eﬃciency of the SFD for 20 O beams at 300 MeV/nucleon
as a function of HV. The intensities of cocktail beams
were > 106 ppp during the experiment; nevertheless,the detection eﬃciency for Z = 8 was maintained atnearly 100%.
From these measurements, it was conﬁrmed that the
SFD is useful as a beam-momentum tagging counter.
Such a detector would be useful at the Big RIPS in the
RIBF.
References
1) O. Sasaki et al.: IEEE Trans. Nucl. Sci. 46, 1871 (1999).

Seal

Al flange
100

Scintillation
fiber
Efficiency [%]

80

60

Total
M1
M2
C1
C2
20O

300 MeV/u
60 degrees

40

50 100 mm
20

Fig. 1. Schematic view of SFD.
∗1
∗2
∗3
∗4

0

Department of Physics, Tohoku University
Cyclotron and Radioisotope Center , Tohoku University
Department of Physics, Kyoto University
Department of Applied Physics, Miyazaki University

250

300

350
400
High Voltage [V]

450

500

Fig. 2. HV dependence of eﬃciency for 20 O beams.

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1

RIKEN Accel. Prog. Rep. 40 (2007)

A collinear fast beam laser spectroscopy apparatus for Ni isotopes
V. Lioubimov,∗2 M. Wada,∗1 A. Takamine,∗1,∗3 T. Nakamura,∗4 Y. Ishida,∗1 H. Iimura,∗5 K. Okada,∗6
H. A. Schuessler,∗2 and Y. Yamazaki,∗1,∗3
Laser
light
Faradaycup

Quadrupole Quartet Lens

Ion Source

Faradaycup

Dipole Magnet

Dipole Magnet

FluorescenceregionCondenser
LensesQuadrupole
Triplet Lens

Photomultiplier

ChargeExchange
Cell
Spherical mirror

Ion
SourceQuadrupole
QuartetLens

PMT

Fig. 1. The photo and the scheme of the off-line collinear
fast beam apparatus.

+

Fluorescence Intensity, [counts/0.15 s]

Collinear fast laser spectroscopy is a powerful
method to obtain nuclear data from optical measurements. We have chosen to study the Ni isotopes as thefirst candidates to be investigated at SLOWRI since
they belong to an unexplored region of nuclear structure and due to their refractory properties have notbeen available at other accelerator facilities. We plan
to determine the nuclear charge radii via isotope shift(IS) measurements and the nuclear moments via hfs
measurements.1)
An off-line collinear fast beam apparatus is being
constructed as shown in Fig. 1. An electro-magnetic
mass separator which consists of a hollow-cathode ion
source, an electrostatic quadrupole quartet and a 90◦
magnetic deflector having the mean beam radius of 30
cm and the maximum magnetic field of 1 T was build
and being tested. The guiding principle of the ion optics design is to have wide beam in horizontal direction
inside the dipole magnet to achieve high mass dispersion with a limited size of the magnet. The mass separated ion beam is guided to the collinear fast beam
apparatus via an electrostatic qudrupole triplet withsome steering devices. All the power supplies and monitor devices are controlled by a network-based systemwith Labview software.
The interaction region with a laser beam has twomodes: one is for ionic beams whose velocity at thefluorescence detection point can be varied by an electrostatic acceleration / deceleration for ±3 kV. Otheris for neutral beams. A charge exchange cell can belocated at just upstream of the fluorescence detection
point and the velocity of the neutralized atom can bevaried by changing the potential of the cell. The fluorescence photons from the ions or atoms at the interaction region are accumulated by a spherical mirror
and two condenser lenses and focused on to a photomultiplier. The total detection efficiency for a 320 nm
photon is evaluated to be 5%.
We had tested the setup with 36,40Ar+ ion beam forthe transitions at 611.6616 nm from the metastablestate.The laser induced fluorescence spectrum for40
Ar+ is shown in Fig. 2. Our next plan is to proceed to Ni isotopes with the charge exchange and fluorescence detection scheme. The collinear resonanceionization scheme for Ni is also planned in the next

24000

Laser Induced Fluorescence for Ar at transition 611.6616 nm
Atom mass =A40(Argon), Acceleration Voltage =20 kV
Ion current = 890 nA, Sweeping Voltage = -90~1000V
Number of scans= 10 , laser tuned to λL=611.028 nm

22000
20000
18000
16000
14000
12000
10000
8000
6000
200

220

240

260

280

300

Decelerating Voltage,[V](Total Voltage=Accelerating Voltage- Sweep Starting Voltage-Decelerating Voltage)

Fig. 2. Laser induced fluorescence intensity of 40 Ar+ as afunction of the decelerating voltage. Laser wavelength
was fixed at 611.028 nm .

step to improve the sensitivity drastically.
∗1
∗2
∗3
∗4
∗5
∗6

Atomic Physics Laboratory, RIKEN
Department of Physics, Texas A&M University
Graduate School of Arts and Science, University of Tokyo
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
Japan Atomic Energy Research InstituteDepartment of Physics, Sophia University

References
1) M. Wada et al.: RIKEN Accel. Prog. Rep. 38, 168(2005).

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RIKEN Accel. Prog. Rep. 40 (2007)

Development of a Mott polarimeter for T-violation experiment
H. Kawamura∗1 , T. Arai∗2 , K. Asahi∗2 , T. Inoue∗2 , D. Kameda, J. Murata∗1 , D. Nagae∗2 , T. Nagatomo, K.
Narita∗1 , K. Shimada∗2 , T. Sugimoto, M. Takemura∗2 , K. Takase∗2 , T. Toyoda∗1 , R. Tsutsui∗1 , M. Uchida∗2 , H.
Ueno, and A. Yoshimi
A new Mott polarimeter for a time-reversal violation
experiment has been developed. A test experimentusing plastic scintillation counters was performed at
RARF E6 beamline in order to evaluate the detector
performance as a polarimeter.
According to the CP T theorem, any violation of
the combined particle-anti particle and space inversion symmetries is equal to a violation of time-reversal
symmetry. Any observation of a time-reversal symmetry violation would be a signal of new physics beyond
the standard model. The terms appear in the allowed
β-decay rate function W ; the usual parity violating
β asymmetry parameter A and the parity and timereversal violating triple correlation coefficient R1) .
W ∝1+A~~p~e hJihJi
p~e·+ R~σe ·×+ ... .
Ee J
J
Ee

Here J~ denotes the spin of the parent nucleus, whereas
p~e , Ee , and ~σe correspond to the momentum, energy,
and spin of the electron, respectively.
In this experiment, 31 Al or 32 Al were used as aparent nucleus. Spin-polarized Al nuclei were produced from the projectile fragmentation reaction from
95MeV/nucleon 40 Ar beam on a Nb target. The Al
fragments were separated using RIPS. The polarizedfragments were implanted in a single crystal stopper
to which the external static magnetic field was applied.
The polarization of the Al nucleus was deduced fromthe β-decay asymmetry detected by the plastic scintillator telescopes placed θ = 0◦ and 180◦ with respect
to the Al polarization axis.
The transverse polarization of the electrons emitted
in the β-decay is deduced from the up-down asymmetry in the Mott scattering at backward angles. At
backward scattering angles the cross-section is small
but the analyzing power is large, and the figure of
merit reaches the maximum value at ∼120◦ . A 9µmthick gold foil is used as the analyzer foil. The Mott
polarimeter was placed at 90cm from the stopper.
90cm
～～

13cm
stopping

Al beamelectronstoppertrans.
analyzer foil
vetoFig. 1. Setup of the experiments.
∗1∗2

Our detection system is based on plastic scintillators; 2mm thick transmission counter (center) and 1cm
thick stopping counters (up or down) (Fig.1). Figure 2
shows the obtained TDC spectrum between the centerand up counters. No accidental events are observedin the experimental results, guaranteeing the performance of our polarimeter. However the electrons scattered at the inactive parts of the setup, such as framesor supports, were not rejected at all. Therefore, theeffect of analyzing power was small and couldn’t beconfirmed in this test.

Department of Physics, Rikkyo University
Department of Physics, Tokyo Institute of Technology

Fig. 2. TDC spectrum of the β-decay measurement withup counter. The counts “with foil (solid line)” exceed“without foil (dotted line)”.

As a result, it is concluded that the polarimeter using plastic scintillators is susceptible to backgrounds
and have a small solid angle. A tracking detectorbased polarimeter can provide the high efficiency andreduces dominant backgrounds. In addition, the Mott
polarimeter can detect the β-decay asymmetry. By using a tracking detector between an electron source anda scattering foil, both tracks before and after scattering can effectively be detected in a test measurement
using a radiation source. From this motivation, therefore, we would apply a 3-dimensional tracking detector
to overcome the problems.
We have tested the plastic scintillation counter arrayas a Mott polarimeter. In order to obtain a sufficient
rejection power for the background events, multi-wiredrift chamber has been employed. We are testing theperformance of a polarimeter in more detail. In the
future, an experiment to study a time reversal symmetry violation will be performed with a multi-wire drift
chamber at KEK-TRIAC.
References
1) J.D. Jackson, S.B. Treiman, and H.W. Wyld: Phys.
Rev. 106, 517 (1957); Nucl. Phys. 4, 206 (1957).

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Accel.Prog.
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Rep. 40
40(2007)(2007)PHENIX silicon vertex tracker projectY. Akiba, J. Asai, E.T Atomssa,∗1 K. Boyle,∗2 S. Chollet,∗1 V. Cianciolo,∗3 A. Deshpande,∗2,∗4 A. Dion,2O. Drapier,∗1 A. Drees,∗2 H. En’yo, K. Fujiwara,∗5 F. Gastaldi,∗1 Y. Goto, R. Granier de Cassagnac,∗1
R. Ichimiya, H. Kano, M. Kawashima,∗6 K. Kurita,∗6 M. Kurosawa, Z. Li,∗7 A. Lebedev,∗8 E.J. Mannel,∗9
R. Muto, R. Nouicer∗7 M. Nguyen,∗2 C. Ogilvie∗8 H. Ohnishi, Y. Onuki, R. Pak,∗7 C. Pancake,∗2
K. Sakashita,∗10 M. Sekimoto,∗11 E. Shafto,∗2 W. Sondheim,∗12 A. Taketani, H. Themann,∗2 J. Tojo,
T. Yamamoto∗13 , and PHENIX VTX collaboration.
We have proposed a silicon vertex tracker (VTX)
for the PHENIX experiment at RHIC. The VTX will
substantially enhance the physics capabilities of the
PHENIX central arm spectrometers. Our primary aim
is to carry out precise measurements of heavy-quark
production (charm and beauty) in A + A, p(d) + A,
and polarized p + p collisions. These are key measurements that are required for future RHIC programs,
both for studies of the dense partonic matter producedin heavy-ion collisions and for the measurements of thenucleon spin-structure functions.
The main physics topics addressed by the VTX are
as follows.
• Probing high-density partonic matter

The bottom and charm decay components can be statistically separated from the DCA distribution. This
will enable us to measure the nuclear modification factor, RAA , and the elliptic flow strength, v2 , of charmand bottom. Figure 2 shows expected statistical accuracy of charm and bottom v2 measurements in the firstyear of operation of the VTX detector in Au+Au collisions. The VTX also provides charged particle tracking
in a large solid angle, which enable us to measure direct
photon plus jet in p+p as well as di-hadron correlationfrom di-jets and γ + jet in Au+Au collisions.
The VTX detector consists of two inner layers of silicon pixel detectors and two outer layers of silicon strip
detectors. The detector covers |η| < 1.2 in pseudo-◦ Energy loss of heavy quarks (charm and bottom) in dense matter◦ Elliptic flow of heavy quarks in dense matter◦ Precise measurement of open heavy-quark
production◦ Modification of jets by medium effects◦ Thermal dileptons from dense matter• Measurements of gluon spin structure of nucleon◦ ∆G/G with heavy-quark production◦ ∆G/G with γ-jet measurement• Nucleon structure in nuclei◦ Gluon shadowing over broad x-range
PHENIX has studied heavy quark production in p+p
and Au+Au collisions from heavy-flavor decay electrons1,2) . The VTX detector will improve the measurements by separating charm and bottom decay components. Figure 1 shows expected distributions of distance to the closest approach (DCA) of electrons fromheavy flavor decay measured by the VTX detector.

Fig. 1. Expected DCA distributions of electrons fromheavy flavor decay (charm and bottom) for 2 < peT < 3
GeV/c measured by the VTX detector.

∗1

LLR, Ecole Polytechnique, CNRS-IN2P3, France
StonyBrook University, USA∗3 Oak Ride National Laboratory, USA∗4 RIKEN BNL Research Center, USA∗5 Niigata University, Japan∗6 Rikkyo University, Japan∗7 Brookhaven National Laboratory, USA∗8 Iowa State University, USA∗9 Columbia University, USA∗10 Tokyo Institute of Technology, Japan∗11 High Energy Accelerator Research Organization, Japan∗12 Los Alamos National Laboratory, USA∗13 University of Electron-Communications, Japan∗2

Fig. 2. The inclusive v2 (pT ) of heavy flavor decay electrons
is separated into charm (green squares) and bottom(blue triangles) component based on the DCA distribution. The error bars are expected statistical errors.
The v2 of bottom is assumed to be zero.

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RIKEN Accel. Prog. Rep. 40 (2007)

rapidity and ∆φ ≈ 2π in azimuth. The pixel detector3)
has been developed in collaboration with the ALICE
group at CERN (RIKEN–ALICE collaboration). The
pixel chips were used and worked very well in the NA60
experiment. The silicon strip detector4) uses a novel“stripixel” sensor developed at BNL. The sensor is readout using the SVX4 chips developed at FNAL. Figure
3 and figure 4 show 3D mechanical drawings of the
VTX detector, rendered by a mechanical engineering
firm HYTEC.
The main points of progress this year are as follows.

pixel system were completed3,5) . The prototypes
includes the pixel half-ladders, the SPIRO readout modules6) , and a pixel Front End Module(FEM). A prototype pixel half-ladder consisted of
two pixel sensor modules, a 3 cm wide prototype
read-out bus7) , and a bus extender.
• A cosmic ray test of a pixel system prototype
was performed8) . The test system included threesets of the half-ladder prototypes, three prototype
SPIRO modules, and a prototype FEM. Clear cosmic ray tracks were observed in the test.
• Fabrication of the final prototype (1.5 cm) bus isunder way7) .
• Development of a pixel detector assembly system
is under way9) .
• The first Read Out Card (ROC) prototype of the
strip detector is tested at ORNL. A clear MIP
peak of cosmic rays has been observed. The second round prototype ROCs are fabricated andthey will be tested soon.
• Production of the strip sensor is under way.
• Extensive Quality Assuarance (Q/A) tests of the
pre-production strip sensor were carried out at
BNL. Q/A procedure for the sensor has been established.
• Extensive radiation damage tests of the stripixel
sensors have been performed. Prototype sensors
were exposed to neutrons and proton beams10,11) .
Sensors were also placed in PHENIX IR to measure the radiation damage in the actual environment12) . A paper describing these test experiments is in preparation.
• The mechanical and thermal engineering work of
the VTX system is under way by HYTEC.

• The US side of the project have been included in
the US FY07 budget. The total budget is 4.6 M
US dollars over three years (FY07-FY09).
• We have a successful review of the project by DOE
in May 2006, and a subsequent meeting at DOE
in October 2006. The project received approval
for starting the construction of the detector.
• First round prototypes of all components of theFig. 3. A 3D mechanical drawing of one half of the
PHENIX VTX detector. Two inner pixel layers, twoouter strip layers, and the support structure are shown.

Fig. 4. A 3D mechanical drawing of the PHENIX VTX
detector. The drawing includes the suppor structures,the 4 layers of detectors, the signal cables, the read-out
modules, and cooling tubes.

References
1) A. Adare et al.: Phys. Rev. Lett. 97, 252002 (2006).
2) A. Adare et al.: Phys. Rev. Lett. 98, 172301 (2007).
3) A. Taketani et al.: RIKEN Accel. Prog. Rep. 40, 170(2007).
4) A. Deshpande et al.: RIKEN Accel. Prog. Rep. 40,
173 (2007).
5) E. J. Mannel et al.: RIKEN Accel. Prog. Rep. 40, 182(2007).
6) R. Ichimiya et al.: RIKEN Accel. Prog. Rep. 40, 176(2007).
7) K. Fujiwara et al.: RIKEN Accel. Prog. Rep. 40, 186(2007).
8) M. Kurosawa et al.: RIKEN Accel. Prog. Rep. 40, 180(2007).
9) Y. Onuki et al.: RIKEN Accel. Prog. Rep. 40, 171(2007).
10) M. Kawashima et al.: RIKEN Accel. Prog. Rep. 40,
188 (2007).
11) K. Sakashita et al.: RIKEN Accel. Prog. Rep. 40, 190(2007).
12) J. Asai et al.: RIKEN Accel. Prog. Rep. 40, 174(2007).

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RIKEN Accel. Prog. Rep. 40 (2007)

Status overview status of Silicon Pixel detector for PHENIX
A. Taketani, Y. Akiba, J. Asai, E. T. Atomssa,∗1 S. Chollet,∗1 O. Drapier,∗1 A. Dress, ∗2 H. En’yo, M. Finger,∗3
K. Fujiwara, ∗4 F. Gastaldi, ∗1 R. Granier de Cassagnac,∗1 Y. Goto, R. Ichimiya, H. Kano, T. Kawasaki,∗4
M. Kawashima,∗5 K. Kurita,∗5 M. Kurosawa, E. J. Mannel,∗6 Y. Miyamoto,∗7 R. Muto, H. Ohnishi, Y. Onuki,
C. Pancake,∗2 P. Riedler,∗8 E. Shafto,∗2 K. Sakashita,∗9 M. Sekimoto,∗10 T-A. Shibata∗9 W. Sondheim,∗11
J. Tojo,∗9 L. Tomasek,∗12 V. Vrba,∗11 T. Wakabayashi∗7 S. Watanabe∗17 , and Y. Yamamoto∗13
The PHENIX experiment at the Brookhaven National Laboratory will be upgraded with the introduction of a silicon vertex tracker (VTX)1) in 2009 to enhance the physics capability of the PHENIX in bothspin and heavy ion programs in the Relativistic Heavy
Ion Collider. It is important to identify charm and bottom quark productions in large solid-angle coverage inboth programs. The VTX is composed of two inner
layers of pixel detector and two outer layers of stripixel detector. In this article we describe development
and construction of the pixel detector part.
The pixel detector is composed of a pixel sensor, adedicated readout chip, a readout flexible bus, theircontrol/readout board (SPIRO), and a support structure. A signal from each sensor pixel is fed into apreamplifier on the readout chip, by bump bonding.
The signal is digitized in the chip and then transferredto the SPIRO board through the bus. The SPIRO
sends all data to the PHENIX data acquisition system (DAQ) via a 1.6 GBps optical link2) . The support
structure, which is made up of a carbon-epoxy composite, holds a mechanical sensor-readout chip assembly(sensor hybrid) and the flexible bus precisely within
10µm. Also, the stucture includes a cooling pipe witha chlorofluorocarbon-based liquid to remove heat fromthe readout chip.
The sensor hybrid has been delivered to RIKEN by
VTT Inc. A probe station for ensuring the performance of the sensor hybrid was set up at RIKEN Wako
last year.3) The readout chip performance was checkedin terms of functionality electronically and then beta
rays from a checking source were irradiated on the sensor and pixel hit data was readout.4) Only the sensor
hybrid with good performance3) was assembled withthe bus and support structure. Evaluated informationis stored in a database and referred to the detailed
selection of sensor hybrids.
A trial flexible bus of 3 cm width5) was fabricated∗1

Ecole Polytechnique, CNRS-IN2P3, France
Stony Brook University, USA∗3 Charles University, Czech Republic∗4 Niigata University, Japan∗5 Rikkyo University, Japan∗6 Columbia University, USA∗7 Tokyo Metropolitan College of Industiral Technology, Japan∗8 European Organization for Nuclea Research, Switzerland∗9 Tokyo Institute of Technology, Japan∗10 High Energy Accelerator Research Organization, Japan∗11 Los Alamos National Laboratory, USA∗12 Institute of Physics, Academy of Sciences, Czech Republic∗13 University of Electro-Communications∗2and assembled with the sensor hybrid and a 45 cm longbus extender. The bus was fabricated with a design
rule of 70 µm line and 50 µm space. This assembled
stave was connected to the SPIRO board.6) . Threesets of stave and SPIROs were made. Individual combinations of a stave and a SPIRO board combination
were tested using a VME-based control/data acquisition system. Then these were stacked vertically as atelescope array. Forty eight cosmic ray events wereread out and reconstructed as straight line of pixel
hits.7)
Owing to the small space around the beam pipe region, the width of the bus should be 1.5 cm, the sameas the width of the sensor hybrid with 188 signal lines.
A 3 µm-thick Cu foil is used as a bus signal conductor
for 60 µm-pitch signal lines. The design and performance the simulation of electorical performance were
performed, and a 1.5 cm-wide bus is under fabrication
at the time of this report submission.8)
The required accuracy of assembly is less than 10µm. A dedicated assemble machine was designed andfabricated. An assembly procedure is developed9) .
For what production in 2007, a test bench for readout electronics is developed. It has many test pins on
the board for the observing real signal shape.6)
A pixel readout system was developed and tested.
The prototype system successfully read out cosmic-ray
events. A mechanical assembly procedure was developed with actual jigs. The production of such mechanical staves and electronics will start in 2007 in RIKEN,
Ecole Polytechnique, and Stony Brook University. The
entire VTX detector will be ready at the PHENIX experimental hall in 2009.
References
1) N. Baker et.al:Proposal for Silicon Vertex Tracker(VTX)
for the PHENIX Experiment. (2005)
2) E. J. Eric et. al.: RIKEN Accel. Prog. Rep. 40(2007)182
3) K. Fujiwara et al.: RIKEN Accel. Prog. Rep.39(2006)207
4) K. Kurosawa et.al.:
RIKEN Accel Prog. Rep.
40(2007)178
5) A. Taketani et.al.:
RIKEN Accel Prog. Rep.
39(2006)209
6) R. Ichimiya et.al.:
RIKEN Accel Prog. Rep.
40(2007)176
7) K. Kurosawa et.al.:
RIKEN Accel Prog. Rep.
40(2007)180
8) K. Fujiwara et.al.:
RIKEN Accel Prog. Rep.
40(2007)186
9) Y. Onuki et.al.: RIKEN Accel Prog. Rep. 40(2007)171- 170 -

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Silicon pixel detector assembly procedure for PHENIX upgrade
Y. Onuki, Y. Akiba, J. Asai, H. En’yo, K. Fujiwara,∗1 R. Ichimiya, H. Kano, M. Kurosawa, R. Muto, H. Ohnishi,
A. Taketani, Y. Yamamoto∗2 and PHENIX VTX Collaboration
The relativistic heavy-ion collider (RHIC) has been
operated at Brookhaven National Laboratory (BNL)√
to provide collisions of polarized proton-proton s up√
to 500 GeV and heavy ion sN N up to 200 GeV. The
pioneering high energy nuclear interaction experiment(PHENIX) detector has been installed at one of the 6intersection regions of RHIC.
The silicon vertex tracker (VTX) for the PHENIX
detector will be installed in summer 2009 to enhance
the physics capabilities. The upgrade will enable theprecise measurement of heavy quarks, which carry direct signals from quark gluon plasma in heavy-ion collisions and fundamental information on gluon polarization in polarized proton-proton collisions. VTX consists of two major parts: the inner two layers are pixeltype sensors and the outer two layers are strip-type
sensors. The inner two pixel layers have 10, 20-pixel
staves in the φ direction. RIKEN is responsible forfabricating all the staves. A stave is formed by 4 sensor hybrids3,4) . A stave can be separated into 4 components, two buses1) which are flexible circuit boards
made with Al/Cu and kapton, 4 sensor hybrids, a support plate2) which is made with Carbon/Carbon(C/C)
composite and a cooling structure. These components
have to be assembled to maintain high alignment precision such as 10µm.
In December 2005, we achieved a milestone: the first
prototype stave had been assembled. The prototype
was assembled manually at Hayashi-Seimitsu Co. It
takes about 1 week to assemble without the wire bonding procedure. However this manufacturing method
for stave is too expensive and time consuming for the
production phase. Next, what we should establish is
on assembly procedure for the production phase.
In this report, we describe the assembly procedure
for the production phase. In particular, we focused on
the alignment procedure.

Fig. 2. Microscope jig.
The microscope has sufficient magnification to visualize thealinment mark on the sensor hybrid. We can see the markon the monitor. The long-stroke X-stage has good precision for parallelism maintaining with less than 10 µm in therunning range. Also, the stage has a magnemeter, which isused for precise position measurement with sub-µm accuracy.

Fig. 3. Alingment jig
An alingment jig is used by putting it on the microscope
jig. sensor hybrids are placed on the jig and fixed one by
one independently by vacuum holes.

Fig. 1. Prototype half stave.

Several special jigs for assembly were fabricated lastyear by Daiya Seiki Co. The alignment procedure wasestablished using these jigs.
∗1∗2

Science and Technology, Niigata University, Japan
Uvniversity of Electro-Communications, Tokyo, Japan

Fig. 4. XY θ stage jig
The jig has X-Y-translation and rotation θ stages with micrometers for aligning a sensor hybrid. Top of a sensor hybrid is chucked by the vacuum holes of the jig and aligned
for proper position monitoring using the microscope jig.
The alignment of the sensor hybrid can be performed one
by one with the jig.

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RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 5. Turn jig
The jig is used for upside-down aligned sensor hybrids andgluing between the sensor hybrids and the support plate.
The micrometer is used to prevent from weight on the sensor hybrids and to set the gap between the sensor hybrids
and the support plate for gluing. Vacuum hole equippedon the bottom.

Fig. 6. Procedures 2 and 3.

Fig. 7. Procedure 4.

brids in a line and glue aligned ladders and a support.
Procedure 1: Set the sensor hybrids one by one ina line at the same interval with the magnescale andmicroscope on the alignment jig. Vacuum chucking
ON to fix.
Procedure 2: Place the XYθ stage jig on the alignment jig. Release the vacuum chucking of the alinment
jig for the first sensor hybrid. When the vacuum chucking of the XYθ jig is turn ON, the sensor hybrid can be
moved each direction with micrometers of the XYθ jig.
When the alignment is complete, turn ON the vacuum
chucking of the alignment jig, and release the vacuum
chucking of the XYθ jig.
Procedure 3: Take off the XYθ stage, and attachsecond sensor hybrid. The second, third and fourth
sensor hybrids are aligned one by one using the sameprocedure.
Procedure 4: Set the turn jig on the 4 aligned sensor
hybrids. Move the turn jig as close as possible to theladder with the micrometer. Chuck the up side of theladder with the vacuum hole of the turn jig. Releasethe vacuum of the alignment jig. Confirm whether thealignment is maintained with the through hole windowof the turn jig. If the ladder moved and does not satisfy
the 10µm alignment, repeat the previous procedure.
Procedure 5: Take off the turn jig from the alignment jig. The ladders are picked up on the turn jig tomaintain the alignment.
Procedure 6: Place the support plate on the alignment jig and chucking to fix. Glue on the support platewith a dispenser machine.
Procedure 7: Place the turn jig on the support plate.
Move down the turn jig as close as possible to the support with the micrometer. The thickness of the gluelayer can be controlled with the micrometer. Leave
glue until it is cured maintaining chucking.
These procedures can reduce the assembly time from
1 week to 1 day. In particular, alignment can be completed in just twenty minutes. We think the same procedures can be applied for the assembly of the bus.
In summary, the assembly of PHENIX/VTX detector has been discussed and is currently progressing with cooperation from researchers and companies.
The first round of manufacturing using the production
phase method will start in beginning of 2007.
References
1) A. Taketani: RIKEN Accel. Prog. Rep. 38, 233 (2005).
2) J. Asai: RIKEN Accel. Prog. Rep. 38, 235 (2005).
3) K. Fujiwara: RIKEN Accel. Prog. Rep. 38, 228 (2005).
4) H. Ohnishi: RIKEN Accel. Prog. Rep. 38, 230 (2005).
5) Y. Onuki: RIKEN Accel. Prog. Rep. 39, 205 (2006).

Fig. 8. Procedure 7.

In particular, we considered aligning 4 sensor hy-

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Phenix VTX Tracker Upgrade: Stripixel Layers
A. Deshpande∗1 for the PHENIX VTX Collaboration
The PHENIX silicon vertex tracker (VTX)1,2) has
four layers: the inner two layers consist of silicon pixel
detectors and the outer two of silicon strips of a novel
design. The pixel detectors are funded by RIKEN3) ,while the outer two ”stripixel layers” were recently approved for funding by the US-DOE at the cost of $4.6M
in US FY07, and will be the main focus of this contribution.
The PHENIX VTX has been primarily motivated by
the study of heavy quark (charm and beauty) production in high energy A − A, d − A and p − p collisions at
RHIC. The interaction of heavy quarks with the dense
partonic matter produced in heavy ion collisions willallow us an unprecedented study of the properties ofthat matter. We will study energy loss of the heavy
quarks as they traverse through this medium, study
their flow properties in this medium using the VTX
detector1,2) . The heavy quark production in polarizedp − p collisions also allows us to explore the nucleon
spin structure. Another advantage the VTX will afford us is the wide acceptance range −1 < η < 1 and
0 < φ < 2π, which will allow us to determine the direction of a jet produced in a pp → γjet event using the
track multiplicity in the jet production. Knowing thejet direction is crucial for determining the event kinematics with precision, leading to better understandingof the gluon’s role in proton structure.
The silicon ”stripixel” sensor is a novel design for a
detector of this kind, developed at BNL.4) . The silicon sensor is a single ended, DC-coupled, two dimensional sensitive detector. The design has distinct advantages for the fabrication and the signal processing.
The reader is referred to1) for detailed design diagramsand dimensions. The stripixel silicon sensor technology developed for the PHENIX upgrade, including themask design and the processing technology were transferred to Hammamatsu Photonics (HPK) in Japan formass production. In 2005/6 HPK delivered the firstpre-production wafers of 625, 500 µm. The dicing of
the pre-production wafers was done at BNL as wellas HPK. A preproduction stripixel sensor is shown in
Fig.1.
Initial sensor testing to learn and to develop the
QA criteria was performed at the RBRC laboratory
at BNL (BNL). Some specialized tests on mechanical dimensions were also performed at University of
New Mexico (UNM). Each sensor went through a detailed mechanical and electrical check. The 500 µm
sensors were rejected early as they showed significantly
higher leakage currents at comparable bias voltages,∗1

Department of Physics & Astronomy, Stony Brook University

Fig. 1. Photograph of the silicon stripixel sensor from thepre-production batch produced by HPK.

compared to their 625 µm counterparts (6 µA compared to 300 nA at VF D = 120V). After significant
testing and discussions a general criteria for acceptanceof a wafer was defined and delivered to HPK: That includes(1) passing of visual inspection: no scratches etc.
(2) sensor thikness 625 ± 15 µ.
(3) Si resistivity 5-19 kOhms(4) depletion voltage 50-250 V(5) junction breakdown > 350 V(6) passivated top of the active area except for bonding pads and ground ring(7) maximum of 1% bad stripixels in the whole sensor and maximum 3 bad sensors in one section
A number of graduate students and post doctoral
fellows in the group were trained to do sensor testing
and QA. The QA of the production sensors will be performed in the three QA stations planned in the project:
The RBRC Laboratory at BNL (BNL facility), the silicon QA laboratory at Stony Brook University (SBU) ,and a laboratory for specialized tests (especially of mechanical properties) at the University of New Mexico(UNM). The first batch of the silicon wafers is expected
to arrive at BNL around January’07., at which detailed
QA operations will begin. As this article goes to print,
the first efforts to design and build a prototype ladder
are being initiated.
References
1) PHENIX Silicon vertex tracker upgrade, http://www.phenix.bnl.gov/phenix/WWW/public/docs/proposals/VTX-PROPOSAL jul2004.pdf
2) Y. Akiba et al., RIKEN Accel. Prog. Rep. 40, xxx, 2007
3) A. Taketani et al., RIKEN Accel. Prog. Rep. 40, xxx,
20074) Z. Li, Nucl. Inst. and Meth. A518 (2004) 738- 173 -

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Radiation Damage Study of Silicon Stripixel Sensor at the PHENIXInteraction Region
J. Asai, R. Ichimiya, M. Kawashima,∗1 K. Kurita,∗1 K. Sakashita,∗2 and A. Taketani.
We are studying the characteristics of quark gluon
plasma (QGP) and the spin structure of protons
using the Relativistic Heavy Ion Collider (RHIC)
at Brookhaven National Laboratory (BNL). The
PHENIX is a detector for measuring particles in A +A, p(d) + A, and polarized p + p collisions. A silicon vertex tracker (VTX) will be installed to upgrade
PHENIX in 2009 for succeeding a running period of
10 years.1) The VTX can identify the decay of heavy
quarks by the precise measurement of the decay vertex
and works as a large-solid-angle detector. It consistsof a barrel detector and a forward detector. In thebarrel detector, the inner two cylindrical layers use asilicon pixel detector2) and the outer two cylindricallayers use a silicon strip detector. In this article, wereport the radiation damage study of the silicon stripixel sensor3,4) at the PHENIX Interaction Region (IR)in 2006. We estimated the radiation damage from theincrease of leakage current and extrapolate it for a running period of 10 years.
The stripixel sensor will be placed at 10 cm and14 cm away from the beam line. The expected integrated luminosity is 4000 pb−1 . Radiation damage
is mainly caused by point defects in Si. The main
damage effect is the increase of leakage current. We
will use the SVX4 readout chip produced by FERMILAB.5) The preamplifier has a 200 fC dynamic range,
and the change accumulated in the preamp needs tobe discharged periodically. This preamp reset is done
every 13 µsec, which is the beam bunch circulation
cycle around the RHIC ring. Therefore, it allows
a 15 nA/strip maximum to avoid preamp saturation
within the reset interval. The leakage current of the
non-irradiated stripixel sensor is about 0.1 nA/strip.
The biggest concern is the increase of leakage current
caused by radiation damage. The increase of leakage
current (∆I) in the volume (V ) can be written as;∆I/V = αΦeq ,(1)

where α is the radiation damage parameter constant.
It depends on the thermal history from the start of theirradiation. The typical value of α is 4 × 10−17 A/cm
after annealing. Φeq is the fluence per cm−2 of 1 MeV
neutrons which causes the equivalent radiation damage
to the detector.
We determined the increase of leakage current of theirradiated stripixel sensor in a 14.1 MeV neutron beam
experiment at the Rikkyo Univ. and a 16 MeV proton
beam experiment at the Univ. of Tsukuba6,7) . In ad∗1
∗2

Department of Physics, Rikkyo University
Department of Physics, Tokyo Institute of Technology

dition, the stripixel sensor was also irradiated at thePHENIX IR in 2006. It was placed at r = 10 cm fromthe beam line. The setup of the stripixel sensor isshown in Fig. 1. It is exactly the same in thermsof its location on the real VTX detector, which will
be installed. Two kinds of diodes were placed for theradiation reference monitor of the stripixel sensor on
the same fixture. The diode sizes were 0.1 cm2 and0.25 cm2 . The thicknesses were both 400 µm. The
stripixel sensor and the reference diodes were held inplace in the PHENIX IR for 44 days. The integrated
luminosity during the irradiation period was 12 pb−1 .
Then the stripixel sensor and diodes were shipped to
RIKEN for the measurement of their characteristicchange. The bias voltage dependences of measured
distributions of capacitance (C) and leakage current (I)are shown in Fig. 2. The full depletion voltage (VF D )was determined graphically utilizing of the flat positions of the C-V curve. The increase of leakage current
was determined before and after irradiation at VF D .
The radiation damage parameter constant α was calculated to be 3.21×10−17 A/cm by the temperature
history from the start of the irradiation. The fluencesof both the stripixel sensor and diodes estimated using
Eq. 1. are shown in Fig. 3. The fluence of the stripixel
sensor was 9.2×109 Neq /cm2 . The average fluence ofthe diodes was 10×109 Neq /cm2 . The expected fluenceof the stripixel sensor for a 10-year running period is
3.1×1012 Neq /cm2 .

Fig. 1. Stripixel sensor setup

We combine the three experimental results to draw
a conclusion on the effect of radiation on the stripixel
sensor. Results measured at 20 ◦ C are found to lie on- 174 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

circuit at 15 nA/strip crosses the expected fluenceΦeq = 3.1 × 1012 Neq /cm2 for the 10-year running period at around the 0 ◦ C line. Therefore, the required
operating temperature of the stripixel sensor is about
0 ◦ C to avoid preamp saturation due to the constantleakage current caused by radiation damage.

Fig. 2. (1): Bias voltage dependences of capacitance before
and after irradiation. (2) Bias voltage dependences ofleakage current before and after irradiation

Fig. 4. Three experimental results of increase of leakage
current as a function of fluence of reference diode. The
temperature dependence is obtained follows Eq. 1. The
vertical dashed line is the expected fluence for the 10year running period: 3.1× 1012 Neq /cm2 . The horizontal dashed line is indicates the saturation level of thecircuit: 15 nA/strip.

References

Fig. 3. Fluences of irradiated stripixel sensor and diodeson the stripixel sensor board at the PHENIX IR

a line expressed by Eq. 1 as shown in Fig. 4. Leakage
current I depends on the temperature T [K] as;
I = AT 2 exp(−Eg /2kB T ),(2)

Here, A is the sensor constant, Eg is the energy gapof silicon (Eg = 1.2 eV), and kB is the Boltzmann constant (kB = 8.6 × 10−5 eV/K), respectively, the leakage currents for various temperatures are also plotted together in Fig. 4. The saturation level of the2- 175 -

1) Y. Akiba et al.: Proposal for a Silicon Vertex Tracker(VTX) for the PHENIX Experiment (Brookhaven National Laboratory, Upton, NY, 2005); RIKEN Accel.
Prog. Rep. 40, 168 (2007).
2) A. Taketani et al.: RIKEN Accel. Prog. Rep. 40, 170(2007).
3) Z. Li et al.: Nucl. Instrum. Methods Phys. Res. 518,
300 (2004).
4) J. Tojo et al.: RIKEN Accel. Prog. Rep. 38, 231 (2005).
5) B. Krieger et al.: IEEE Trans. Nucl. Sci. 51, 1968
(2004).
6) M. Kawashima et al.: RIKEN Accel. Prog. Rep. 40, 188(2007).
7) K. Sakashita et al.: RIKEN Accel. Prog. Rep. 40, 190(2007).

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 40 (2007)(2007)Development of PHENIX Silicon Pixel Interface ReadOut (SPIRO)
ModuleR. Ichimiya, F. Gastaldi, ∗2 Y. Akiba, J. Asai, E. T. Atomssa, ∗2 R. Granier de Cassagnac, ∗2 S. Chollet, ∗2
O. Drapier, ∗2 H. E’nyo, K. Fujiwara,∗1 H. Kano, M. Kurosawa, E. J. Mannel, ∗4 H. Ohnishi, Y. Onuki,
C. Pancake, ∗3 E. Shafto, ∗3 A. Taketaniand PHENIX VTX Collaboration
As part of the upgrade program of the PHENIX
detector at RHIC, a silicon VerTeX tracker (VTX)
1,2)
is being developed for installation in 2009. This
VTX provides ∼ 2π coverage in azimuth over a rapidity range of |η| < 1.3 and will have a 50 µm resolution
in Distance of Closest Approach (DCA). It consistsof two inner pixel barrels followed by two outer strip
barrels. Each pixel barrel is formed by 10 (first barrel at 2.5 cm) and 20 (second barrel at 5 cm) ladders.
Each pixel ladder consists of two half-ladders with anactive length of 11 cm for covering the η > 0 and η < 0regions. The readout system for the pixel detector is
divided into 60 subsystems; each subsystem contains
one half-ladder, as shown in Fig. 1.

ceives data from the SPIRO board, reformats it into
the standard PHENIX data format and transmits itto the PHENIX DAQ system. In addition, it provides
clock, trigger and slow control to the SPIRO boards.
1

SPIRO board
The SPIRO board has the following functions:• Sending control signals to the half-ladder.
• Multiplexing data from the half-ladder and sending it to the FEM via optical links.
• Providing a slow control to the pixel readout chips
and SPIRO board itself.
• Data format conversion to match the PHENIX requirement.

45cm
11cm

Half-ladder

Data

AnalogPilot
ASIC

32bit
parallel

32bit

32x4bits of 10MHz

Digital Pilot
CTRL
ASIC

32bit
32bit

Digital Pilot
CTRL
ASIC
AnalogPilot
ASIC

OE/EO

F
P
G
A

GOL
CTRL

GOL
CTRL
CLK

PHENIX control room

Fig. 1. Pixel detector readout scheme.

Fig. 2. Block diagram of SPIRO.

The half-ladder consists of two pixel sensors withfour bump-bonded ALICE1LHCb readout chips3) .
Each readout chip measures 13.6 mm × 12.8 mm sensitive area and is divided into 8192 pixel cells (256 rows
× 32 columns) of 50µm × 425µm. The sensors andreadout chips used in the pixel detector were originallydeveloped for the ALICE experiment4) and LHCb experiment5) at CERN.
Data are readout through four 32-bit buses on thehalf-ladder by a SPIRO board. The SPIRO board receives data from pixel bus and sends it to a FrontEnd Module (FEM) via optical links. The FEM re-

The core component of the SPIRO board is the Digital Pilot ASIC.6) On the pixel readout chip being initialized, each of the two pixel chip pairs presents 256×2
sequential words of data on a 32-bit bus synchronously
at a beam collision clock frequency of 10 MHz as shownin Fig. 1. In order to meet the readout timing requirements of PHENIX, four readout chips need to be readout in parallel. Due to the limited space for the SPIRO
boards, a new Digital Pilot ASIC with twice the number of input channels was developed using same design
rules and radiation tolerant technology as the ALICE
Digital Pilot ASIC. The PHENIX Digital Pilot ASIC
with 2 × 32 inputs can simultaneously read a 32-bit
word from two pixel readout chip. Each 32-bit input
handles on output from a pair of chips, which represent
512 sequential words of pixel data. Thus, two Digital
Pilot ASICs are required to fully readout a pixel halfladder, meeting the PHENIX DAQ readout timing re-

∗1
∗2
∗3
∗4

Graduate School of Science and Technology, Niigata University, Japan
Laboratoire Leprince-Ringuet, École Polytechnique, CNRSIN2P3, France
Department of Physics and Astronomy, Stony Brook University, USA
Columbia University, Nevis Laboratories, USA- 176 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

quirements.
Each SPIRO board has two Analog Pilot ASICs that
supply reference voltages and currents for the pixel
readout chips and monitor voltages, currents and temperature on the pixel half-ladder.
The data transmission from a readout chip to a pilot
chip is performed as follows. A bus carries 2 × 32-bit
data at a frequency of 10 MHz to a Digital Pilot chip.
The Digital Pilot chip is designed to produce an output at 40 MHz. This allows four 25 ns transmission
cycles to be available before the next data word fromthe readout chips arrives. The first two clock cycles arereferred to as “cycle-0” and the last two clock cycles
as “cycle-1”. If no pixel data readout is performed,
only status data (slot-0) is transmitted in cycle-0. In
this case, cycle-1 contains (empty) data. During pixel
data readout, after transmission of status data (slot-0)
in cycle-0, event header information (slot-1a) is transmitted in cycle-1. This initial transmission is followedby the repeated transmissions of (slot-0) and (slot-1b)
containing the pixel hit information. The principle ofdata transmission is illustrated in Fig. 3.

3

Using Xilinx FPGAs has technical difficulties inovercoming in the PHENIX high radiation environments and may expense radiation induced effects suchas Single Event Effect (SEE) in its configuration memory (e.g. bit flips) and Total Ionizing Damage (TID)
for the flash memory used by PROM (e.g. malfunctionof write feature).8,9) Therefore, an antifuse FPGA (Axcelerator family by Actel)10) , which has no configuration memory but is a one-time programmable device,
was chosen for the final design. This FPGA (commercial grade, which is much inexpensive than the special
rad-hard grades) has already been tested by the ATLAS group8) . A Triple Module Redundancy (TMR)
library for immunization against SEE for user registers
and a FIFO library are also provided by Actel.
The final prototype was designed by the École Polytechnique group to satisfy the following criteria:• Feedback of all knowledge from the first prototype
testing.
• Use only radiation-tolerant qualified devices.
• Minimize its board size.
4

References

First Prototype

The first SPIRO prototype was designed by theÉcole Polytechnique group. In this prototype, a data
format conversion which replaced redundant “fast-or”
fields by parity fields and a protocol change from
CIMT (G-Link) to 8B/10B encoding was implemented
in a Xilinx FPGA7) . During the testing of the prototype, it was discovered that a FIFO between the
PHENIX Digital Pilot ASIC and GOL serializer was
required. The FIFO implemented in this FPGA, forms
the clock domain interface between a PHENIX global
clock (≈ 38 MHz) and a low-jitter local clock (40 MHz)for high-speed links. More specifically, the data serialization is performed by a GOL chip, which is a CERN
solution capable of serializing up to a 32-bit data input
at 40 MHz and driving high-speed serial links at a frequency of 1.6 Gbps. The GOL chip requires a 40 MHz
input clock with a peak-to-peak jitter less than 100 ps.
A quartz crystal located on the SPIRO board generates the 40 MHz clock to feed the GOL chip with therequired jitter specifications, whereas the Digital Pilot
chip works on the PHENIX global clock.

1) Y. Akiba et al.: Proposal for a Silicon Vertex Tracker(VTX) for the PHENIX Experiment, BNL-722042004, Physics Dept. BNL (2004).
2) Y. Akiba et al.: RIKEN Accel. Prog. Rep. 40 (2007).
3) K. Wyllie: ALICE1LHCB Preliminary Users Manual
Version 3/7/01,
http://kwyllie.home.cern.ch/kwyllie/ALICE1LHCB.htm
4) ALICE Experiment: http://aliceinfo.cern.ch/
5) LHCb Experiment: http://lhcb.web.cern.ch/lhcb/
6) A. Kluge: ALICE Silicon Pixel On Detector Pilot System OPS2003-The missing manual, ALICE-INT-2004030, CERN (2005).
7) Xilinx Inc.: http://www.xilinx.com/
8) R. Ichimiya et al.: IEEE Trans. Nucl. Sci., Vol.52, Issue 4, 1061-1066 (2005).
http://cdsweb.cern.ch/search.py?recid=812814&ln=en
9) T. Miyahira and G. Swift: Proc. MAPLD Conf. (1998).
http://klabs.org/richcontent/MAPLDCon98/Abstracts/c4.htm
10) Actel Corp.: http://www.actel.com/
11) M. Kurosawa et al.: RIKEN Accel. Prog. Rep. 40(2007).

- 177 2summary

The first prototype board was designed, built andtested in the 2006. The prototype was used to readout
three half-ladders in a cosmic ray test11) done in thesummer of 2006. The pre-production design (should
be a final design) work has been completed, and its
prototype boards will be delivered in February 2007.

Fig. 3. Data transmission from pixel detector.

2

Final Design

RIKEN40 (2007)RIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 40(2007)

Quality assurance test of readout chips and pixel sensor hybrids for
PHENIX
M. Kurosawa, Y. Akiba, J. Asai, H. En’yo, R. Ichimiya, K. Fujiwara,∗1 R. Muto, Y. Onuki, K. Sakashita,∗2
A. Taketani and Y. Yamamoto∗3
PHENIX at RHIC-BNL has been upgraded witha silicon vertex tracker (VTX)1) , which consists offour layers of barrel detectors, namely, two inner silicon pixel detectors (SPD) and two outer silicon strip
detectors (SSD). In the plan of upgrading PHENIX
VTX, we are developing inner SPD. SPD is made up
of 30 ladders, each of which consists of four sensor hybrids2) . A sensor hybrid is an assembly of a silicon
pixel sensor and four readout chips3) (ALICE1LHCb)
bump-bonded with 20-µm-diameter bumps to the sensor (bonded by VTTa) ). The readout chip has 8192
pixel cells arranged in 32 columns and 256 rows. The
size of pixel is 50 µm × 425 µm. Before installation in
the experiment, quality assurance (QA) is required forthe readout chips and the pixel sensor hybrids. In thisreport, we describe a recent results of the QA test.
The QA test system mainly consists of a probe station (SUSS MacroTec), a DAQ adapter board, VME
equipment for a DAQ system, and a Windows machine.
Figure 1 shows the QA test system in a clean room
at RIKEN. A readout chip wafer, which has 86 readout chips, and the sensor hybrid are tested with theprobe station. Probe data are taken and analyzed using a LabVIEW-based program running on the Windows machine.

Items to be Checked for Readout Chips(1) Measurement of current consumption.
• The current consumptions of analog and digital circuits of the readout chips are measured.
(2) Test of JTAG and DAC functionality.
• It is confirmed whether configuration settings
in the chip are readable and writable bymeans of a JTAG protocol.
• The digital-to-analog converter (DAC) linearity is calibrated.
(3) Measurement of minimum threshold and noiselevel.
• Minimum threshold in all pixel matrix is determined.
(4) Measurements of mean threshold and meannoise for the complete pixel matrix.
• The test pulse from the pulsar inside thechip is sent to each pixel cell and the mean
threshold and noise levels are determined.
Items to be Checked for Sensor Hybrids(1) The same tests as those in items 1, 3 and 4 andpart of JTAG functionality test in item2.
• The sensor is biased at 50 V during the measurements.

2TQDG5VCVKQP
575/CETQ6GE(2) Performance test of SPD with the β source(90 Sr).
• Faulty bump bonds and maximum efficiency
are checked by β source measurement.

9KPFQPU2%

At the end of the QA test, the measured and analyzed data are sent to a PostgreSQL database server located at a secure area accessible only from the internal
RIKEN network. The secure shell (SSH) connection isused to transfer the data from the Windows machine
to the database server. The data in the database canbe accessed from the web interface in the secure area.
The tested readout chips and the sensor hybrids are
categorized into three classes, Class I, II, and III. The
chips and sensor hybrids classified into Class I are used
for the experiment. The readout chips (sensor hybrids)
categorized into Class I satisfy the following criteria.

8/'Fig. 1. QA test system in a clean room at RIKEN.

A check list items for the QA test of the readoutchips and sensor hybrids is as follows.
∗1
∗2
∗3
a)

Science and Technology, Niigata University, JapanTokyo Institute of Technology, Japan
University of Electro-Communications, Tokyo, JapanVTT Electronics, Tekniikantie 17, Epsoo, P.O. Box 1101,
FIN-02044 Epsoo, Finland- 178 -• Current consumptions lower than 350 mA and 270
mA for analog and digital circuits, respectively.
• A complete JTAG and DAC functionality forreadout chips and a complete JTAG functionality for sensor hybrids.
• Mean threshold lower than 1800 electrons (30001RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 2. Typical response of a sensor hybrid, categorized into Class I, to β rays. Good and faulty bumpbonds are shown in black and white, respectively.

electrons).
• Less than 1% defect pixels in mean threshold scan(and source test).
The readout chips or sensor hybrids with a percentage of dead pixels higher than 1% are categorized into
Class II. The others are classified into Class III.
In the 22 readout chip wafers, 1892 readout chips
have been tested. Figure 3 shows typical results. In
accordance with the criteria described above, the results of the QA test are summarized in Table 1. The
average of the mean threshold and the mean noise for
the Class I readout chips are about 1400 electrons and
120 electrons, respectively.

from 90 Sr is shown in Fig. 2.
Table 2. Summary of QA test results for sensor hybrids.
Classification
Class IClass IIClass III

Number of Hybrids82
8

We have obtained 8 sensor hybrids and 692 readout chips classified into Class I. A total of 120 sensor
hybrids and 680 readout chips are required for the experiment. The required number of tested readout chips
for the experiment was satisfied. We intend to focus
on the QA test of the sensor hybrids.

Table 1. Summary of QA test results for readout chips.
Classification
Class IClass IIClass III

References

Number of Chips
692
174
1026

1) Y. Akiba et al.: RIKEN Accel. Prog. Rep. 40, 168(2007).
2) Y. Onuki et al.: RIKEN Accel. Prog. Rep. 40, 171(2007).
3) K. Fujiwara et al.: RIKEN Accel. Prog. Rep. 38, 228(2005).

Fig. 3. Typical classification map of a chip wafer. Readoutchips with a cross mark are not used for the experiment.

Eighteen sensor hybrids have been tested. Table 2
shows the summary of QA test results. We obtained
the mean threshold and mean noise of 2600 electronsand 140 electrons for Class I sensor hybrids, respectively. The average maximum efficiency of Class I sensor hybrids is about 98%. A typical response to β rays2

- 179 -

RIKENAccel.
Accel.Prog.
Prog.Rep.
Rep. 40
40(2007)(2007)
RIKEN

Cosmic-ray experiment with PHENIX silicon pixel sensor hybrids
M. Kurosawa, R. Ichimiya, Y. Akiba, J. Asai, H. En’yo, K. Fujiwara,∗1 Y. Onuki, C. Pancake,∗2 E. Shafto,∗2
A. Taketani and PHENIX VTX Collaboration
The PHENIX is an experiment aiming to study hot
and dense matter and the spin structure of nucleons at
Brookhaven National Laboratory’s Relativistic Heavy
Ion Collider (RHIC). The PHENIX is being upgradedwith the introduction of a silicon vertex tracker (VTX)
to extend it’s physics capability1) . The VTX is composed of a four-layer barrel detector, two outer silicon
strip detectors (SSD) and two inner silicon pixel detectors (SPD). The basic component of the SPD is a ladder assembled using four sensor hybrids2) . One sensor
hybrid has four readout chips bump-bonded to a silicon
pixel sensor, with pixel sizes of 50 µm in the z (row)direction and 425 µm in the φ (column)-direction3) .
To test the data taking system (DAQ) and the performance of the silicon pixel detector, a cosmic-ray experiment was performed at Stony Brook University (NY,USA) in June 2006. In this report, we show the first
tracking results of the cosmic-ray experiment with silicon pixel sensors.
The setup of the cosmic-ray experiment is shown in
Fig. 1. Three sensor hybrids with SPIRO boards, one
FEM module and two plastic scintillators as an event
trigger were used in the experiment. The SPIRO board
is an on-detector electronic that controls the sensor hybrid components, collects data from the sensor hybrid
and sends them to the FEM module via optical links.
The FEM (Front End Module) is the off-detector electronic that sends clock and command signals to the
SPIRO boards and collects data. The data will besent to the PHENIX DAQ system. The FEM has
a USB interface for connecting a PC. In this experiment, a stand-alone DAQ system was constructed using the FEM module and a Windows PC. When the
FEM module receives a trigger signal from a scintillator trigger, it generates a sequence of Trigger&DAQ
commands to take the data. The taken data are stored
in the FEM module and then read out by the Windows
PC. This data taking system has been operated successfully.
Forty-eight cosmic-ray events with hits in three sensor hybrids were collected. An event display of acosmic-ray event is shown in Fig. 2. The top three
images show the hit positions of cosmic rays on eachsensor hybrid. The bottom image represents a reconstructed track in 3D with three hit positions (crosspoints) on each layer. The track was reconstructed by
the least-squares fit method after the position alignment described below.
Three sensor hybrids were aligned manually with a∗1∗2

Science and Technology, Niigata University, Japan
Stony Brook University, USA

Fig. 1. Setup of cosmic-ray experiment. The vertical distance between the sensor hybrids was 60 mm. Sensor
hybrid B was not used in the experiment.

precision on the order of 1 mm. A much more precise alignment was performed by offline analysis. The
alignment of sensor hybrids were made for only translation not for rotation using a residual value. The residual was defined as the distance between an intersection
position of a reconstructed track and a hit position on
the sensor. The mean residual was taken as the correction horizontal plane position. The correction andfitting of what were iterated until the mean residual
for three layers was minimum. Figure 3 shows theresidual distributions of Layer 1 after the alignment.
The standard deviations of these residual distributions
were calculated to be 184 ± 27 µm and 140 ± 24 µm
in the column and row directions, respectively. Thesestandard deviations were used to obtain an intrinsic- 180 -

1

RIKEN Accel. Prog. Rep. 40 (2007)• The energy loss of the 4 GeV cosmic rays passing
through concrete with an average thickness of 6 m
is 2.5 GeV (The experiment was performed in anunderground area of a six-story building.).
• The thickness of the scattering material is estimated to be the average thickness of the material
through which the particle passed.

Fig. 2. Event display of typical cosmic ray event. (a)-(c)The square point represents the hit position on eachlayer. (d) The cross points and straight line are the hit
position and reconstructed track, respectively.

position resolution of a sensor hybrid.
χ2 /

S

14






3
3.808
/3

12.51± 2.55
Cns nt
M an-24.26± 31.25

a184.2± 27.2

L

count

count




L
1 R SID 
COL


 

1 R SI 
ROW

7

χ2 /




8.24 9/a139.6± 23.5

Cns nt 5.484± 1.170
M an-35.37± 25.92
S

6

12
5
10
4

8
6

3

4

2

2

(a)

0
-2000 -1500 -1000 -5001

0

500 1000 1500 2000

column [ µm]References(b)0-1000-800 -600 -00 -200 0

200 400 600 800 1000

row [ µm]

Fig. 3. (a) and (b) are the residual distributions in thecolumn and row directions on Layer 1.

The position resolution of the sensor hybrid is due totwo components. One is the intrinsic position resolution and the other one is the effect of multiple scattering in the support of the sensor hybrids. We obtained
the intrinsic position resolution by estimating the effect of multiple scattering.
The multiple scattering angle is given by the following equation4) .
·
µ
¶¸
r
x
x
13.6MeV
1 + 0.038ln(1)< θ 0 >2 =βp
X0
X0Here, x/X0 represents the thickness of the scattering
medium. The following conditions were used to evaluate the resolution due to multiple scattering.
• The average energy of cosmic rays at ground levelis 4 GeV.

2

From the calculation under the above conditions, themultiple scattering angle on each layer was estimatedto be θ0 = 2.5 mrad. Then, the resolution of each layer
due to the multiple scattering was calculated to be σ0= 150 µm. Thus, we obtained the intrinsic position
resolution in the column and row directions to be σcol= 160 ± 33 µm and σrow = 65 ± 30 µm, respectively.
The intrinsic position resolution depends on pixel
pitch sizes of 50 µm in the row direction and of 425µm in the column direction. Then the expected
resolu√tions of the √pixel sensor are 123 µm (425/ 12 µm) and14 µm (50/ 12 µm) in the column and row directions,
respectively. The difference between the measured andexpected intrinsic position resolutions is due to a poor
statistic of the cosmic-ray data and the ambiguity ofthe estimation of the effect of multiple scattering. In
the future, we intend to carry out a more precise estimation of multiple scattering resolution.
The first measurement of cosmic rays has been performed with silicon pixel sensor hybrids at Stony Brook
University. The data taking system was successfully
operated. Forty-eight clear tracks of cosmic rays were
measured. It was found that the sensor hybrid had
sufficient performance for the PHENIX experiment.

- 181 -

1) Y. Akiba et al.: RIKEN Accel. Prog. Rep. 40, 168(2007).
2) Y. Onuki et al.: RIKEN Accel. Prog. Rep. 40, 171(2007).
3) K. Fujiwara et al.: RIKEN Accel. Prog. Rep. 38, 228(2005).
4) Particle Data Group: Phys. Lett. B592, 245 (2004).

RIKENAccel.
Accel.Prog.
Prog.Rep.
Rep.
(2007)RIKEN
4040(2007)

Overview of the Readout Electronics for the Silicon Vertex Tracker
for the PHENIX ExperimentE.J. Mannel,∗1 Y. Akiba, E.T. Atomssa,∗2 M. Bobrek,∗3 C.L. Britton,∗3 S. Chollet,∗2 V. Cianciolo,∗3 L.G.
Clonts,∗3 A. Deshpande,∗4 O. Drapier,∗2 K. Fujiwara,∗5 R. Granier de Cassagnac,∗2 F. Gastaldi,∗3 R. Ichimiya,
H. Kano, R. Nouicer,∗6 C. Pancake,∗4 H.Pei,∗7 , A. Semenov,∗6 E. Shafto,∗4 A. Taketani, L. Tomasek,∗8 J. Tojo,
T. Yamamoto, and PHENIX VTX Collaboration[RHIC, PHENIX, Silicon Detectors, Electronics]
The PHENIX experiment at the Relativistic Heavy
Ion Collider (RHIC) at Brookhaven National Laboratory has approved the silicon vertex tracker (VTX)
upgrade to be installed in 2009. The goal of the
VTX upgrade is to provide precise measurements ofheavy-quark production (charm and beauty) in A+A,
p(d)+A and polarized p+p interactions at RHIC.
These are essential measurements for future heavy-ion
and spin-physics programs at RHIC. In addition, theprecise tracking capabilities of the VTX will provide
significant improvements to other PHENIX physics
measurements.
The VTX consists of two detector sub-systems, thepixel detector and the stripixel detector. The VTX
provides nearly full coverage in azimuth over the rapidity range of |η| < 1.2, with 50µm resolution in the
distance to closest approach. A preliminary design ofthe detector is shown in Fig. 1.
The pixel detector consists of two inner barrels approximately 22cm long. The first barrel with a radiusof 2.5cm is built from 10 pixel ladders, while the secondbarrel is built from 20 pixel ladders.1,2) Each ladder isconstructed from two half-ladders which are mounted
on a carbon composite stave which provides mechanical support and cooling for the ladder. Each halfladder consists of two sensor modules wire-bonded toa multi-layer readout bus (pixel bus) and bus-extenderand is connected to a Silicon PIxel Read-Out (SPIRO)
module. The SPIRO module provides all voltages, control and timing signals and reads out the pixel data fora half ladder. The SPIRO module is connected via optical fiber to the pixel Front End Module (FEM) whichis the interface to the PHENIX data acquisition system(DAQ).
The pixel detector uses the ALICE1LHCb readout
chip designed by the CERN EP-MIC group for the
ALICE and LHCb experiments.3) Four readout chips
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Columbia University, Nevis Laboritories, USA
Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRSIN2P3, France
Oak Ridge National Laboratory, USA
Department of Physics and Astronomy, Stony Brook University, USA
Graduate School of Science and Technology, Niigata Univeristy, Japan
Brookhaven National Laboratory, USA
Iowa State Univeristy, USA
Institute of Physics, Academy of Sciences, Czech RepublicFig. 1. A cut-away view of the proposed VTX detector
showing the two inner pixel barrels, two outer stripixel
barrels, and cooling and support structure.

are bump-bonded to a sensor module. The sensor
modules are mounted on the pixel bus, which is akapton/copper/aluminum printed circuit board (PCB)
providing power and control signals to the readoutchips and bring data out to the SPIRO module on
a 128 bit bus. Connections between the readout chipand bus are made by wire-bonds. The bus-extender,
a flexible multi-layer copper/kapton PCB, is used tothe extend the bus to the SPIRO board, allowing theSPIRO board to be located outside the acceptance of
the PHENIX detector and in a lower radiation environment. The pixel bus and bus-extender are being
designed, prototyped and built at RIKEN.
The SPIRO module is used to control and readout
the the ALICE1LHCb chips. In order to meet thereadout timing requirements for PHENIX, four ALICE1LHCb chips must be readout in parallel. Two
PHENIX Digital Pilot ASIC’s on the SPIRO board
each readout two ALICE1LHCb chips in parallel at a
rate of 10MHz, allowing a half ladder to be completely
read out in 51.2µs, achieving a maximum data rateof 25kHz. The PHENIX Digital Pilot ASIC was developed by the RIKEN group using the same design
rules and radiation tolerant technology as used for the- 182 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

ALICE pixel pilot ASIC.4) Data from the PHENIX
Digital Pilot chip is serialized with the Gigabit Optical Link (GOL) chip which is radiation tolerant andcapable of transmitting data at 1.6 Gbits/sec.5) TheSPIRO module also has two Analog Pilot chips usedfor voltage control and monitoring on the half-ladder.6)
The SPIRO modules are being designed, prototyped
and built at LLR-Ecole Polytechnique in France.
The Pixel FEM is the interface between two SPIRO
modules and the PHENIX DAQ and slow control systems. Commands, initialization parameters and clock
timing information is transmitted to the SPIRO modules and pixel data is received from the SPIRO modules, requiring three optical fibers per SPIRO module.
In addition, the FEM formats the pixel data into standard PHENIX data packages, prior to inclusion of thedata into a PHENIX data stream. The pixel FEM isbeing designed and prototyped at Stony Brook University.
Prototype pixel buses, bus-extenders, SPIRO boards
and pixel FEM’s were used to build three pixel half
ladders for a cosmic ray test stand which was successfully tested at Stony Brook University in the summerof 2006.7)
The stripixel detector consists of the two outer barrels located at a radius of 10cm and 14cm and is composed of 18 and 26 ladders respectively. Each laddercontains 5 or 6 stripixel sensor modules for the innerand outer barrels respectively. Each sensor module
consists of a sensor with x and y strips providing stereo
readout of the sensor, and a ReadOut Card (ROC) andare mounted on a carbon fiber stave providing the mechanical support and cooling for the ladder. Each ladder is readout from one end to a stripixel FEM locatednear the detector which provides the interface to the
PHENIX data acquisition system.
Readout of the stripixel sensors is controlled by the
ROC which has 12 SVX4 chips developed at Fermi
National Laboratory and Lawrence Berkeley National
Laboratory.8) Each SVX4 chip reads out 128 strips
with 8 bit ADC’s, allows for on-board zero suppression, has a 46 deep pipeline buffer and is radiation
hard. Control of the readout is done by the ROC Control Chip (RCC), a custom radiation tolerant ASIC designed at Oak Ridge National Laboratory. The RCC
serves as a de-multiplexer, directing the serial, clock
and control inputs, and the data outputs minimizing the effects of single-point failures and reducing thenumber of readout cables required for each ladder. All
RCC’s on a ladder share a common bus which is also
connected to the Pilot Module (PM). The PM passes
all data between the stripixel FEM and the ladder andprovides voltage regulation, filtering and distribution
to the ladders.
The stripixel FEM serves as the interface between
the ROC’s and the PHENIX DAQ and slow control
systems. The FEM consists of a Controls Interface2- 183 -

Board (CIB) and 11 Data Interface Boards (DIB)
housed in a single crate. The CIB receives control
and timing information from the PHENIX DAQ andslow control system and distributes the information
to the DIB’s. The DIB’s send the control and clock
information to the stripixel ladders and receive andformat accepted event data from the stripixel ladders
and transmit it to the PHENIX DAQ via fiber opticalcables. The ROC’s, PM’s and FEM’s are being designed, prototyped, and built at Oak Ridge National
Laboratory.
A prototype stripixel ROC and FEM was successfully tested with cosmic-rays at Oak Ridge National
Laboratory in the summer of 2006. The energy distribution in ADC counts for minimum ionizing particles
and noise from this test is shown in Fig. 2. A clear separation of minimum ionizing particles from the noise
is seen with a signal-to-noise ratio of ∼ 10.

Fig. 2. The Energy distribution in ADC counts from thestripixel cosmic ray test.

The design and prototyping of the electronics for the
VTX detector for PHENIX has started. Prototypesof the pixel and stripixel detectors have been successfully tested using cosmic rays in 2006. Fabrication of
the electronics will begin in 2007 and be completed
in time for testing and installation in the summer of2009. Data taking by the VTX detector at PHENIX
is scheduled to start in the fall of 2009, with the firstphysics results expected in 2010.
References
1) H. Kano, et al. : RIKEN Accel Prog. Rep. 39(2006)211
2) K. Fujiwara, et al.: RIKEN Accel Prog. Rep. 40(2007)
3) K. Wyllie: ALICE1LHCB Documentation40 (2001)
4) A. Kluge: ALICE Silicon Pixel On Detector Pilot System OPS2003-The missing manual 40 (2005)
5) P. Moreira et al.: GOL Reference Manual 40 (2005)
6) G. Anelli, R. Dinapoli, A. Kluge: Specification of thedigital control part of the ANAPIL2 40 (2004)
7) R. Ichimiyma et al.: RIKEN Accel Prog Rep. 40 (2007)8) L. Christofek et al.: SVX4 User’s Manual (2003)

RIKENAccel.
Accel.Prog.
Prog.Rep.
Rep. 40
40(2007)(2007)RIKEN

Development of amplifier-discriminator readout system ofcathode strip chamber for muon trigger upgradeat RHIC PHENIX
K. Shoji,∗ for the PHENIX Collaboration
One of the major goals of the PHENIX experiment1)
at the Relativistic Heavy Ion Collider (RHIC) is theunderstanding of the spin structure of a proton. W
boson production in proton-proton collisions is a goodprobe for investigating the sea quark spin contribution because the production depends on both quark
ﬂavor and helicity.2) Experimentally, W boson production can be measured by detecting high-momentum
muon decayed from W. The trigger upgrade for thehigh-momentum muon is proposed for studying the W
physics in the PHENIX experiment.
PHENIX can detect W via the muon decay channel
with the forward Muon Arm,3) which consists of theMuon Tracker (MuTr) and Muon IDentiﬁer (MuID).
The MuTr is a set of cathode strip chambers thatare used for momentum measurement with a magnetic
ﬁeld. The MuID is a set of ﬁve chamber layers withalternating layers of steel walls that can distinguishmuons from hadrons. The MuID also serves as a ﬁrstlevel muon trigger for each beam crossing.
Most of the muons that decayed from a W boson
have a momentum above 40 GeV/c. However, with
the MuID trigger whose momentum threshold is ∼2
GeV/c, low-momentum muons dominate, and trigger
rate will become a problem in the near future. When
the RHIC design luminosity of 2 × 1032 cm−2 s−1 at√
s = 500 GeV is achieved, the expected reaction rate
is 12 MHz. With the existing MuID trigger whose rejection factor (RF) is about 250, the trigger rate is
as high as 48 kHz. However, 2 kHz is the allowed
bandwidth in the PHENIX data acquisition system.
Therefore we need a new trigger system with an RFof 6000 to record all the W signals. By selecting highmomentum muons at the trigger level, the desired RF
can be achieved. We propose a new trigger using
MuTr cathode strip hit information. Figure 1 shows
the schematic of the new trigger. We can obtain therough track of a particle from the strip hit pattern at
the trigger level and select high-momentum muons bydetermining sagitta, which is the distance between thepassage point at Station 2 and the interpolation pointfrom Station 1 and Station 3. The simulation results
show that this new trigger can provide a maximum RFof 24000.
The current front end electronics (FEE) of the MuTr
chamber is designed to measure the amount of charge
induced on strips. This information is used to measure
the passage point of a particle by oﬄine analysis. The∗1

Department of Physics, Kyoto University%CVJQFG5VTKR/W6T5VCVKQP/W6T5VCVKQPUCIKVVC/W6T5VCVKQP$%QNNKUKQP2QKPVFig. 1. New trigger schematic

position resolution with a standard deviation of 100µm is the value desired for the design and we need toachieve 1% noise level for a typical charge on FEE.
To realize a new trigger system, we need not only
information about the amount of charge induced on
strips but also strip hit information for trigger decision. Therefore, we propose to split the raw signal
line from the chamber as shown in Fig. 2. One signal
line goes to the cathode preampliﬁer (CPA) on current
FEE as in the old system and the other signal line connects to the ampliﬁer-discriminator board (AD-board)
to provide strip hit information. This conﬁguration
has the advantages in that we need not change theentire readout system and it is cost-eﬀective.
The split ratio can be controlled by adding the capacitor Csplit as shown in Fig. 2. The ratio of thecharge ﬂowing into FEE and the AD-board equals
the ratio of the CPA’s eﬀective capacitance (∼900pF)
and the Csplit value. Very low noise level should beachieved on FEE for the required position resolution
so that stealing too much raw signal is not allowed.
Moreover, seeing from FEE, to add the Csplit meansincreasing load capacitance, which results in high noiselevel. However, we need a suﬃcient charge for the ADboard to obtain an eﬃciency as that is as good thatof the trigger. We should determine the Csplit value
with extreme caution considering these factors.
The split signal is ampliﬁed and discriminated tosend out strip hit information. The time jitter ofthis output is preferred to be within 100 nsec because
RHIC beam bunch crossing occurs at 9.4 MHz. We- 184 -

1

RIKEN Accel. Prog. Rep. 40 (2007)
ADC Distribution/W6T%JCOGDGTADC (MPV)%WTTGPV(''#&%&#6#%2##/7#&%

250

200)CKPO8H%+PVGITCVKQPVKOGWUGE
'0%

6TKIIGT150%URNKV#&$QCTF

100

5VTKR*KV+PHQTOCVKQP
2TG#OR&KUETK

50
1800

Fig. 2. New configuration of chamber readout

1820

1840

1860

1880

1900

1920
HV

Fig. 4. The Most Probable Value (MPV) of ADC counts
vs High Voltage (HV) of MuTr chamber. Results fromreadout with FEE alone is shown as open circle. Triangles come from the readout with combined system of
FEE and AD-board. Csplit is 100pF.

ADC (RMS)

Noise RMS
2.6
2.4
2.2
2
1.8
1.6
1.4

Fig. 3. Picture of prototype amplifier-discriminator board

1.2
1
0.8
0

use a cable-less constant fraction discriminator (CFD),
which is modeled after the MuID readout system andcalled pseudo-CFD, to minimize the time jitter due topulse height variations. The fact that the pseudo-CFD
technique requires no delay cable, which saves space
and we can obtain high channel density.
On the basis of these concepts, we produced an ADboard prototype (Fig. 3) that has 64 channels on a
6U size card. To estimate its performance, we performed an experiment using the duplicate of the MuTr
chamber exposed to electron beam at the Laboratoryof Nuclear Science, Tohoku University in November
2006.
Figure 4 shows the most probable values (MPVs)
of ADC counts from FEE as the function of a highvoltage applied to the MuTr chamber. In PHENIX,
the current operating voltages are usually in the rangeof 1850-1900V. The plot shows MPVs when the MuTr
chamber is read out with FEE alone or both FEE andAD-board whose Csplit is 100pF. When the AD-board
is added to the readout system, we can obtain about
10% of signals from FEE. The RMS noise is also shownin Fig. 5 with ADC value and it increases by a factorof 1.25 on average. These observations indicate that2- 185 -

5

10

15

20

25
30
Channel Number

Fig. 5. The RMS noise measurement for typical channels
in units of ADC counts. Symbols are the same as Fig.
4.

when the Csplit is 100pF, we need a signal gain of ∼1.4
to recover the noise level before the split.
The analysis of the position resolution of the MuTr
chamber and the performance study of the AD-board
as the trigger system, for example, eﬃciency, will beﬁnished soon. We obtained data with several Csplit
values and tested some patterns of the pseudo-CFD
circuit. Therefore, we will be able to ﬁnalize our studies of the parameters. We hope to ﬁnish the AD-board
development soon.
References
1) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res. A
499, 469 (2003).
2) G. Bunce et al.: Annu. Rev. Nucl. Part. Sci. 50, 525(2001).
3) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res. A
499, 537 (2003).

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4040 (2007)(2007)Development of pixel readout bus for PHENIX upgrade
K. Fujiwara∗1 , Y. Akiba, J. Asai, H. En’yo,
R. Ichimiya, H. Kano, T. Kawasaki∗1 , H. Ohnishi, Y. Onuki, K. Takano∗2 , A. Taketani and S. Watanabe∗2
The PHENIX experiment at the relativistic heavy
ion collider (RHIC) at Brookhaven National Laboratory will be upgraded by installing a four-layer silicon vertex tracker (VTX) by summer 2009. The VTX
will enhance the physics capabilities of the laboratory
to enable the investigation of new hot and dense nuclear matter in heavy-ion collisions and the structureof proton spin in polarized proton-proton collisions at
the RHIC. The VTX will directly identify heavy-quark
production by measuring displaced decay vertices, andwill reconstruct jets with the acceptance of almost fullazimuthal coverage over the rapidity of |η| < 1.2. It
has a high spatial resolution of 30 ∼ 50 µm for the
distance to the closest approach1) . We report the status of the development of the pixel readout bus of the
PHENIX silicon pixel detector.
The inner two layers are built from 30 hybrid sensor
staves with pixel sensors placed cylindrically covering
approximately 22 cm along the beam direction. The
first layer has a 2.5 cm radius consisting of 10 staves
and the second layer has a 5 cm radius consisting of 20
staves. One ladder is electrically divided into two independent half-ladders2) . Four readout chips are bumpbonded on a single sensor chip using microscopic solder
balls of 20 µm diameter. The device is called sensor
hybrid. One half-ladder has two sensor hybrids. The
sensor hybrids of one half-ladder are wire-bonded toa readout bus of a copper-aluminum-polyimide flexible printed circuit board (FPC), which is supported
by a carbon-composite beam.3) The bus is connected
to a SPIRO board2) , which controls the readout chips,
reads out the data and transfers the binary pixel data
to the PHENIX DAQ system via 1.6 Gbit/sec opticallinks.
The size of the sensor hybrid is 15.6 mm × 57 mm
and the total thickness is ∼ 350 µm. The sensor chip isbased on P+ /N/N+ silicon with a thickness of 200 µm
and is fabricated by CANBERA4) . It is partitioned
into four active areas, each of which has 32 columns(z) × 256 rows (φ) with pixels of 425 µm (z) × 50
µm (φ). For the readout chips, ALICE1LHCb readoutchips are used, which are fabricated using the IBM
0.25 µm CMOS process of incorporating radiationhardened technology. A radiation tolerance of up to 30
MRad was demonstrated by CERN EP Division, MIC
group5) . The size of the chip is 15.6 mm × 13.7 mm
with 150 µm thickness. One chip has 8,192 (32 × 256)
input channels, each of which processes an input signal∗1∗2

Graduate School of Science and Technology, Niigata University, JapanTokyo Metropolitan College of Industrial Technology

individually. A raw signal from each pixel is preamplified and discriminated using a configurable thresholdlevel. The discriminated binary signal is delayed fora programmable duration and then stored to be readout by a downstream data acquisition system. The
chip has 42 internal 8-bit digital-to-analog converters(DACs) for controlling the threshold of discriminatorsand various timings. All configurations are set via a
JTAG serial interface (IEEE Std. 1149.1-1990). The
chip is operated using a 10 MHz clock; therefore, themaximum readout speed is 25.6 µsec/chip with a 32bit line5) .
The SPIRO board includes a digital PILOT chip6) ,which multiplexes and controls the readout chips. The
multiplexed data is passed to a serializer chip (GOL).
The serialized data is transmitted via optical links at
1.6 Gbit/sec. The analog PILOT provides regulated
voltages, current and reference bias to the chips.
The silicon pixel detector has to be operated within
the constraint of the PHENIX DAQ speed of 40 µsec.
We have chosen to expand the number of parallel 32bit data width in the original design of ALICE6) to128 bits. At first, we modified the digital PILOT chip,
which has 2 × 32-bit data width. Using two digital PILOT chips for each half-ladder, the bus becomes 128
bits wide. Thus, four readout chips can be read in parallel. However, this expansion requires a circuit with afour-times-denser layout on the bus. The developmentof such a fine-pitch FPC is necessary.
Finally, by expanding the data width and adopting acopper-aluminum-polyimide FPC, the silicon pixel detector is expected to achieve a readout speed of 51.2
µsec with a total material budget as 1.44 % X0 .
We have been developing a new copper-aluminumpolyimide FPC that has 128-bit data bus width. The
advantage of the FPC is not only its ability to increase
the data bus width fourfold but also it has a reduced
material budget. Although the choice of copper for
signal layers and aluminum for the power and groundlayers is a challenge using existing technology, an aluminum conductor can have less radiation length thana copper one. For our FPC, we are aiming at lessthan 0.28 % X0 . The pixel readout FPC has six layersthat consist of copper, aluminum and polyimide layers.
It contains three signal layers, a through-halls layer, apower layer and a ground layer. Additionally, the FPC
has 188 longitudinal lines. The size of the FPC is 13.9
× 250 mm2 . 7) Therefore, one signal and control line
is 60 µm pitch, the line width is 30 µm and the spaceis 30 µm and the thickness is 3 µm.
To develop this fine-pitch FPC, we adopted the following procedure. 1) We used a HSPICE9) simulation
code for the test bus to estimate signal propagation- 186 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

behavior, crosstalk and the characteristic impedanceof lines. 2) Both a wider test bus (the width is 3 cm)
and a Cu extender for checking the electrical functionality are fabricated. The test bus has a line of 80 µm,
spaces between lines are 60 µm. The Cu extender isconnected with the test bus by wire bonding for forelectrical connection to the SPIRO board. 3) The simulation result is compared with measurement using ascope. 4) The simulation model of the FPC is fabricated. Then, the performance is verified as in step 1.
5) The FPC is fabricated, then it is tested by the sameprocedure as that used for the test bus.
Concerning the functionality of the test bus, it is evaluated as follows. The half-ladder, which contains two
wire-bonded sensor hybrids, is built. Then, the controllability of the readout chips is verified by sending acontrol signal in JTAG protocol. The supply of the reference voltage and current for the DACs, and thresholds for all the chips are confirmed. Next, the numberof and the location of hits on a hybrid sensor induced
by a β-ray source of 90 Sr is obtained. The result isshown in Fig. 1. The source is placed on chip 3 andchip 2, and number of triggers is 50,000. At the sametime, a telescope composed of three half-ladders wasable to detect cosmic ray tracks8) .
Chip3

Chip2
60

250

50

200

Chip1

250

30

0

100

0

5

10

15

20

25

30

0

5

250

1

200

0.8

100

3

10
50

0

5

0

5

10

15

20

25

30

0

2

50

0

5

10

15

20

25

30

0

Data #28

C
A

Data #29
B

Fig. 2. Simulated signal for the test bus (left), measured
signal (right)

0.7
0.6
0.5
0.4

100

0.3
0.2

50

1
0

D

0.9

150

4

15

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30

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Chip0

resistance inhibits the pulse from decreasing to the 0
V. Therefore, we choose a 220 Ω pull-up register instead of 100 Ω. The pull-up voltage is 1.8 V because
the next version of SPIRO will employ a pull-up voltage of 1.8 V. The calculated characteristic impedanceis 178 Ω ∼ 190 Ω. The simulation result is shown in
Fig. 3. Line B in Fig. 3 shows the data signal at the
input pin on a digital PILOT. The rise time is ∼ 70
nsec. The fall time is ∼ 10 nsec. The threshold voltage
is 0.8 V and the low level of line B is 0.3 V. Hence, themargin for noise is 0.5 V. Line C shows the logic levelin the digital PILOT. The duty cycle is 1:1. By selecting the value of the pull-up register, it is expected that
the FPC can send correct data from a readout chip to
the SPIRO.

0.1
0

0

5

10

15

20

25

30

0

C

D

Fig. 1. Hitmap on one hybrid sensor.

The characteristic impedance, the behavior of the
propagation signal and the crosstalk on the test bus
are estimated using the HSPICE simulator9) . The
HSPICE model includes the GTL transmitter in the
ALICE1LHCb readout chip, the FPC, the Cu extender and the GTL receiver in the digital PILOT chip.
The resistance of pull-up registers used for the test
bus is 100 Ω. The calculated characteristic impedanceis 104 Ω ∼ 151 Ω. The simulation result is shown in
Fig. 2 (left) and the measured signal is shown in Fig.
2 (right). Line A shows an input pulse in the readoutchip. Line B in the simulation result shows the data
signal at the input pin on a digital PILOT. The amplitude of the pulse is 2.5 V. The rise time is ∼ 30 nsec.
The fall time is ∼ 15 nsec. Line C shows the logic ina digital PILOT. The duty cycle is 1:1. The signal fordata #29 in Fig. 2 is measured using a scope with 300
MHz analog bandwidth. The amplitude is 2.5 V. The
rise time is ∼ 20 nsec. The fall time is ∼ 15 nsec.
The induced signal of line D is calculated. The amplitude is 0.6 Vpp , and the measured crosstalk is 0.8 Vpp .
As a result, the HSPICE simulation result is consistent
with the measured result. Consequently, this simulation is shown to be reliable.
Also, a simulation model of a 1.5 cm FPC is simulated.
The model is similar to the model of the test bus. Because of the small crosssection of signal lines on the
FPC, its resistance is higher than that of the test bus.
The resistance of the FPC is ∼ 43 Ω/line. The higher

2- 187 -A

B

Fig. 3. Simulated signal for 1.5 cm FPC.

In summary, we have established a simulation model
for a test bus. Then, we showed that the comparisonof the simulation result of the test bus and the measured result using a scope is reliable. By using theestablished simulation model for the 1.5 cm FPC, it isconfirmed that the functionality of the FPC can workwith the HSPICE simulator successfully. Currently the
FPC is under fabrication. We will fabricate a prototype ladder using the FPC and its functionality will be
evaluated.
References
1) Y. Akiba: RIKEN Accel. Prog. Rep. 40, xxx (2006).
2) R. Ichimiya: RIKEN Accel. Prog. Rep. 40, xxx (2006).
3) Y. Onuki: RIKEN Accel. Prog. Rep. 39, xxx (2005).
4) V. Manzari et al.: J. Phys. G30, S1091-S1095, (2004).
5) W. Snoeys et al.: Nucl. Instr Meth. A466, 366, (2001).
6) A. Kluge et al.: Proc PIXEL 2002 Workshop (Monterey,CA) eConfC020909.
7) K. Fujiwara, et al.: Czech. J. Phys. 55 (2005), No. 128) M. Kurosawa: RIKEN Accel. Prog. Rep. 40, xxx (2006)
9) Synopsys Inc: HSPICE Manual (2006).

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep. 40 (2007)(2007)

Beam Test of Stripixel Si Sensor for Radiation Damage Study
M. Kawashima,∗1 J. Asai, K. Kurita,∗1 K. Sakasita,∗2 R. Ichimiya and T. Komatsubara∗3
In the PHENIX experiment at the Relativistic
Heavy Ion Collider (RHIC) in Brookhaven National
Laboratory (BNL), research utilizing high-energy
heavy-ion collision and polarized proton collision is being advanced. We plan to install a silicon vertex detector to improve the vertex tracking performance withhigher resolution of the PHENIX detector system.
We are going to install the newly developed stripixel1) silicon sensor at the PHENIX interaction region(IR). It is important to confirm that the detector canbe operated in the PHENIX environment. RHIC will
deliver polarized proton and heavy-ion beams in thenext ten years, which is the foreseeable duration of
detector usage. The expected integrated luminosity
during the run period is 4 fb−1 when the beams areconverted to proton-proton collision.
Our goal of the beam test is to confirm the radiation
hardness of the silicon sensor. We irradiated the stripixel sensor with particle beams (proton and neutron)and estimated the degradation in 10 years of RHIC
operation.
The increase in leakage current is the biggest concern for us among the known radiation damage effects,
because the maximum leakage current allowed by ourreadout electronics is 15 nA/strip. The main conceptof the stripixel sensor is the two-dimensional position
sensitivity realized by charge sharing while allowing
single-sided readout. The sensitive area of the sensor
is 30.7 mm × 60.0 mm and the thickness is 625 µm.
The entire area is segmented into 80 µm × 1000 µm
rectangular pixels and there are 30 columns and 384
rows. Every pixel consists of two independent spiralelectrodes wound around each other as shown in Fig.
1. In addition to the charge collection pixel, two large
electrically isolated interconnection layers are implemented. One layer is used to interconnect 15 clockwise spirals in the x-direction and other layer is used
to interconnect 15 counterclockwise spirals in anotherdirections called the u-direction. Interconnected pixels
are considered to be strips, hence, the name ”stripixel”,
results the two-dimensional sensitivity is realized by
the combination of x and u hit information while readout electronics are mounted on one side of the sensor.
The electronic components we chose are FNAL SVX4
chips2) and they are all directly coupled to each of theindividual x and u strips on the pixel side of the sensor.
The total number of channels is 1536 (384 × 2 x-strips
and 384 × 2 u-strips).
We aimed at the irradiation test with equivalent
∗1
∗2
∗3

Rikkyo University
Tokyo Institute of Technology
University of Tsukuba

Fig. 1. Stripixel sensor

fluence φeq (particles/cm2 ) < 1013 cm−2 , where φeq
is defined as the fluence of 1 MeV neutrons, whichcauses equivalent radiation damage to the silicon sensors. The Tandem Accelerator Center at the University of Tsukuba was used for the irradiation test. The
test was performed effectively with a 20 MeV proton
beam and φeq of more than 1012 /cm2 was achieved.
The setup of the irradiation experiment at Tsukuba
is shown in Fig. 2.

Fig. 2. Setup

To simulate the uniform irradiation of the stripixel
sensor in the PHENIX environment, we chose to spreadthe proton beam using Coulomb multiple scattering.
An Al plate of 5 mm thickness was inserted 139 cm
upstream of the sensor in the 20 MeV proton beams.
The beam intensity had a Gaussian sharp but we wereable to limit the variation of the fluence over the irradiated stripixel area (3 cm × 3 cm) to be less than 10
percent. The energy loss of the proton beam in the Al
plate was considered and the hardness factor was used
for 16 MeV protons. A Faraday cup was placed at 19.5
cm downstream of the sensor. Blank and spare sensor
setups were also installed on the rotation table in theirradiation chamber.
The penetrating proton beam was monitored by a
Faraday cup, while the sensors were irradiated. The
rotation table in the chamber was used to locate each- 188 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

sensor. The sensors were irradiated in turn without
breaking the vacuum.
As a result, the fluence measured by the Faraday
cup and the monitoring diode readings agree with eachother. We found the proportionality between the fluence and the leakage current. We were able to obtainconsistent values for the amount of irradiation with thereference diode reading. We also confirmed the proton
fluence by activating the Cu foil.
The data are plotted in Fig. 3. They include theresults of experiments that have been carried out previously (experiments at Rikkyo and Kyoto).

Fig. 3. Distribution of comparison of fluence between diodeand beam information.

When experimental results of different irradiation
conditions (i.e. species of the beam particle and its
energy) are compared, it is conventional to convert
what to φeq using the already known conversion factor
κ called the hardness factor. The particle fluence isobtained from the increase in leakage current ∆I per
sensor volume according to the following equation.
∆I/V = α × φeq ,where α is the proportionality constant called thecurrent-related damage rate and has a typical valueof 4.0 × 10−17 A · cm−1 after the annealing process iscompleted. The newly obtained Tsukuba result lies on
the same straight line as that of the data obtain from
Rikkyo and Kyoto Universities.
As a result, we confirmed that the diodes and thestripixel sensor have similar respons to radiation.
References
1) Z. Li,et.al.,”Novel stripixel detector for PHENIX Upgrade”, NIMA 518 300-304 (2004).
2) B. Krieger et al.: IEEE Trans. Nucl. Sci. 51 1968-1973(2004).

2- 189 -

RIKEN Accel.
Accel. Prog.
RIKEN
Prog. Rep.
Rep.4040 (2007)(2007)

Fluence Measurement for Radiation Damage Study of Silicon
Stripixel Sensor
K. Sakashita,∗1 Y. Akiba, J. Asai, R. Ichimiya, M. Kawashima,∗2 K. Kurita,∗2 M. Sekimoto,∗3 A. Taketani, and
PHENIX VTX Collaboration
A silicon vertex detector (VTX) will be installed in
the PHENIX central arm detector in 2009 and will
be worked for 10 years1) . The VTX is composed offour layers. The inner two layers are silicon pixel
sensors2,3) and the outer two layers are silicon stripixel sensors4) , which are single-sided two-dimensional
readout sensors. The silicon stripixel sensors will beplaced at 10cm and 14cm away from the beam line.
The expected integrated luminosity irradiating the silicon stripixel sensors for 10 years is approximately
4fb−1 , and thus, the total ﬂuence is estimated to
be 3×1012 ([1MeV neutron equivalent]/cm2 )5) . Suchstrong radiation would cause signiﬁcant damage tothe silicon stripixel sensor resulting to an increasein the leakage current. The leakage current of morethan 15nA/strip will saturate the front-end electronics. Therefore, the leakage current of the silicon stripixel sensor has been studied.
We irradiated the stripixel sensor with a 16MeV proton beam, which is equivalent to 3×1012 cm−2 , using
the tandem accelerator at the University of Tsukuba6) .
It is important to accurately measure the ﬂuence tostudy radiation damage. The ﬂuence that irradiatedthe silicon stripixel sensor was measured by two methods. One is by use of a silicon diode, whose irradiation
damage characteristics are well known. The other is by
the activation method using a copper (Cu) foil, which
was irradiated simultaneously with the silicon stripixel
sensor. The measurements of the ﬂuence during thisradiation damage test will be described in this report.
The experimental setup is shown in Fig. 1. The energy of the proton beam was 20MeV. The beam size
was much smaller than the size of the silicon stripixel sensor. Therefore the proton beam was spread bya Coulomb multiple scattering through a 5mm-thickaluminum plate placed upstream of the beam. The
beam energy is degraded to about 16MeV in this process. The spread proton beam was irradiated with thesilicon stripixel sensor to measure the radiation damage using setup A, in which the silicon stripixel sensor
was mounted with a collimator to deﬁne the irradiatedarea.
The ﬂuence was ﬁrst measured using the Cu foil A,
which was placed behind the silicon stripixel sensor,
and was thus irradiated with the same amount of ﬂu∗1
∗2
∗3

Tokyo Institute of Technology
Rikkyo University
High Energy Accelerator Research Organizationence as the silicon stripixel sensor. When the Cu foil
was irradiated with the 16 MeV proton beam, 63 Zn is
produced in the Cu foil (eq. 1).
p +63 Cu → n +63 Zn(1)Then the 63 Zn decays into 63 Cu∗ with β + -decay followed by γ-ray emissions with energies of 662keV,
962keV and 1412keV. Then the ﬂuence was obtained
from the activity of the Cu foil by counting γ-rays using a germanium (Ge) detector through the following
relations.
Φ=Nγ λTr×F²BrσNCu dΩA

A = (1 − exp−λTr ){exp−λt1 − exp−λ(t1 +t2 ) }

(2)
(3)

Here, Nγ is the number of γ-rays emitted from the produced 63 Zn, λ is the decay constant of 63 Zn, Tr is irradiation time, ² is γ-ray detection eﬃciency, Br is thebranching ratio of the relevant γ-ray, NCu is the number of 63 Cu atoms, dΩ is the solid angle between theactivated Cu foil and the Ge detector, t1 is start time
for measurement of γ-rays, t2 is measurement time and
F is a conversion factor for 16MeV proton to 1MeV
neutron. The energy calibration and the detection efﬁciency measurement of the Ge detector were carriedout using 60 Co and 137 Cs standard sources. The measured ﬂuence with statistical error is shown in Fig. 2.
The ﬂuence values obtained from three γ-ray lines wereaveraged by weighting their error. It is 2.4×1012 cm−2 .
The ﬂuence was measured by an independent
method using the silicon diode to use the proportionality relation between the ﬂuence and the leakage current of the silicon diode placed by the silicon stripixel
sensor. The coeﬃcient is known from our previous experiment7) . Knowladge of the spatial intensity distribution of the spread beam to transfer the ﬂuence value
at the silicon diode to the one at the position of thesilicon stripixel sensor is necessary.
The spatial distribution and the ﬂuence were measured with a foil activation method using setup B. The
Cu foil B was placed at the same position where the silicon stripixel sensor had been located by revolving theturntable on which all the setups were mounted. The
spatial intensity distribution of the beam is obtained
through the 63 Zn distribution by measuring β + -rays
and X-rays emitted in the β + -decay of 63 Zn with animaging plate (IP).
The IP includes ﬂuorescent material. The β (+) -rays- 190 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

2700
2600
2500
2400
2300
2200
2100
2000
1900

The leakage current of the silicon stripixel sensor isclose to 15nA/strip at 0 degree operation temperature.

×10

9fluence(/cm2)

and X-rays from 63 Zn generate hole-electron pairs in
the IP. Then the pairs are trapped by the ﬂuorescentmaterial. The IP is then stimulated by the Ne-He laser
to release the trapped electrons and holes. When thereleased electrons and holes are annihilated, ultraviolet(UV) photons are generated.
From the intensity of the UV photons, the spatial
distribution of the spread beam was obtained, as shownin Fig. 3. The ratio of the intensity averaged over thesilicon stripixel sensor to that at the beam center is93%. The ratio of the intensity at the silicon diodeto that at the beam center is 73%. It agrees with ourestimation, which is based on the Coulomb multiple
scattering calculation. The ﬂuence that irradiated thesilicon stripixel sensor obtained using the silicon diodeis 2.5×1012 cm−2 . The ﬂuence values obtained by thetwo methods agree with each other and are close to
our goal ﬂuence value, which is 3×1012 cm−2 .

600

800

1000

1200

1400

1600
energy (keV)

Fig. 2. Fluece obtained from three γ-rays counts. Errorbar shows statistical error.

Fig. 1. Schematic of the irradiation setup. Setups A and
B are setup for the measurement of the spatial intensity distribution and the radiation damage study of thesilicon stripixel sensor and the ﬂuence, respectively.

References
1) Y. Akiba et al.: Proposal for a Silicon Vertex Tracker(VTX) for the PHENIX Experiment.
2) A. Taketani et al.: RIKEN Accel. Prog. Rep. 40 (2007)xxx.
3) Z. Li et al.: Nucl. Instrum. Methods Phys. Res. 518(2005) 300.
4) J. Tojyo et al.: RIKEN Accel. Prog. Rep. 38 (2005) 231.
5) J. Asai: RIKEN Accel. Prog. Rep. 40 (2007) xxx.
6) M. Kawashima: RIKEN Accel. Prog. Rep. 40 (2007)xxx.
7) Y. Inoue: Study on radiation damage of the PHENIX
Silicon Vertex Tracker (2005)

2- 191 -

Fig. 3. Spatial intensity distribution of the proton beam.

RIKEN Accel. Prog. Rep. 40 (2007)

PHENIX reaction plane detector
W. Xie for the PHENIX collaboration
Keywords: reaction plan, heavy-ion collisions, RHIC, photo-multipliers, scintillator.
PACS: 29.40.Mc
Event anisotropy is one of the most important
observables in nucleus-nucleus collisions at RHIC. The
large anisotropy amplitude, v2, provides key evidence of theformation of a hot and dense partonic matter in Au+Au
collisions at RHIC. Measurements of v2 in rare observables
such as electrons, photons, and high pT particles can provide
even richer information on the properties of partonic matter.
The measurements of the v2 of these rare probes are not
only limited by luminosities but also rely on accurate
reaction plane measurements. In PHENIX, we use the BBC
to determine the reaction plane. The statistical power of thev2 measurement is reduced by a factor of 6 to 100
compared with the ideal case in Au+Au collisions due to thepoor reaction plane resolution. The situation is even worse
for light ions such as Cu+Cu or at lower energy. This
relatively poor reaction plane resolution of the present
PHENIX detector is a major limiting factor of our v2
measurement of rare signals. Reaction plane determination
by other methods, such as central arm tracks or v1
measurement by ZDC/SMD do not provide better reaction
plane resolution
We propose a new detector for reaction planemeasurement in PHENIX. Comparing to the existing BBC
detector, the new detector will improve the statistical powerof v2 measurements in PHENIX by about a factor of three.
The reaction plane detector will be a paddle typedetector situated in front of the nosecone as shown in Fig.1.
The active area will be composed of plastic scintillating
material with a lead converter in front to increase thedetector performance.
The scintillator will have athickness of 2 cm and will be positioned at 38<|z|<40 cm.
The inner edge of the scintillator will begin at r = 5 cm andextend to r = 33 cm. This allows the detector to cover a
pseudorapidity range of 1.0<|η|<2.8. This coverage waschosen to balance the competing effects of maximum
acceptance and jet induced autocorrelations with the central
arm. The detector will be segmented into 12 sectors in phi
to minimize the impact from dead channels. Each phi sector
will be further divided into two radial sections. The innereta segment will extend from a radius of 5cm to 18cm andthe outer eta segment will continue from 18cm to a radiusof 33cm. This effectively divides the detector into two
rapidity regions, 1.0<η<1.5 and 1.5<η<2.8, which willallow the possibility to study the effect of jet induced
autocorrelations on the reaction plane determination.
Embedded fiber light guides made of BCF92 willconnect the plastic scintillator to the photomultiplier tubes.
An adapter in which the fibers can be embedded will be
used to join the fibers to the photomultiplier tube. The useof fiber light guides has several advantages for this detector
design. Most significantly, the light collection along theradial length of the scintillator is more uniform using- 192 -

embedded fibers than solid light guides. Additionally, thefibers allow for flexibility in the final positioning thephotomultiplier tubes. This is important due to thesensitivity of the tube response to the magnetic field andwill allow the tubes to be repositioned if necessary after
installation.
Mesh dynode photomultiplier tubes, Hamamatsu H6155,
will be used due to the strength of the magnetic field in theregion where the reaction plane detector will be positioned.
A 2 cm thick lead-antimony composite converter isinstalled directly in front of the scintillator. The additionof 2-3% of antimony hardens the converter material andwill improve the mechanical stability of converter when it ismounted. An LED calibration system will be used online tomonitor the stability of the detector.
Lead converter

scintillator(a)(b)
Fig.1. (a). One sector of the detector assembly; (b). One
sector of real detector in the process of assembly. Converter
is not installed yet.
(a)

(b)

Fig.2. (a). One fully assembled sector before installation of
converter.; (b) One arm of the detector in PHENIX innercenter area.
The installation of the detector has been successfully
finished and we are in the process of commissioning thedetector. The plan is to make it fully functional before thestart of RHIC year 2007 Au+Au run and provide theimproved reaction plane measurements. Beside that, thedetector has the potential of serving as the PHENIX
minimum-bias trigger during the low energy Au+Au run
and p+p run. We are currently setting up the trigger and will
also commission the trigger simultaneously.

RIKEN
Prog. Rep.
Rep.4040 (2007)(2007)RIKEN Accel.
Accel. Prog.

Ubiquitous detector system
Y. Watanabe, Y. Kawasaki, Y. Takizawa, T. Hamada, K. Hirota, H. Sato, H.M. Shimizu, T. Ebisuzaki,
H. Baba, M. Kurokawa, T. Fukuchi,∗1 S. Shimoura,∗2 S. Ota,∗2 and T. Motobayashi
We are developing a next-generation DAQ systemthat consists of autonomic data-acquisition modules
distributed over a DAQ network. Each module is attached to its partner detector and can memorize thedetector’s characteristic and history.
In these 30 years, DAQ systems for nuclear physics
experiments have been based on a modular structure,
because of their universality and flexibility. Advanced
studies require more precise measurement and more
detector channels, which cause, for example, complicated cabling and more noise. On the other hand, theinformation technology (IT) field is growing rapidly,
and fast CPUs, large memories, and network technology, among others, have become available at very low
costs. Under such circumstances, we are now developing autonomic data-acquisition modules distributed
over a DAQ network for a more universal and flexible DAQ system. The system is analogous to “ubiquitous computing”, which has widely been recognizedrecently. Thus, we call our project “ubiquitous detector system”.
1

Introduction

The word ubiquitous means “being or seeming tobe everywhere at the same time” (American Heritage
Dictionary). It is used in terms such as “ubiquitous
computing” or “ubiquitous networks”. In both cases,
many tiny computers hidden away from people work
autonomously by communicating with each other, as
shown in Figure 1. To satisfy a person in a house, a decision must be made on the basis of information fromindoor and outdoor temperatures. Two typical methods are used the decision: centralized management anddistributed management. The ubiquitous system is thelatter. Each device has a computer and communicateswith other devices to make a decision. If there weremore devices (e.g. sensors: illuminometers or hygrometers; actuators: light switches or motors for curtains),
they can make the person more comfortable. It is obvious that distributed management is easier to realize
in terms of, for example, expansion because each device is independent and only connected to the network.
The memory of each device is also important. It stores
not only the characteristics of the device but also its
history, such as temperature trends or operation logs.

Fig. 1. Each device communicates with others and makes
decisions to satisfy the person.

ments, whose style has not changed for more than 30
years now. The ubiquitous computing/network will
normally be applied to organize discrete objects. On
the other hand, our ubiquitous detector will be applied to a system that is already set up with numerous
physical cables to make it simple for us to, for example,
unravel tangled threads.
2

Ubiquitous detector“Plug & Play” is a key concept in the ubiquitous
detector system. Figure 2 shows a simple image ofa ubiquitous detector’s usage. Just plugging electricpower and network cables is enough to gather data.
To realize the “plug & play” concept, the ubiquitous
detector has autonomic functions; i.e., record, process,judge, and communicate. In other words, a bare detector must to be connected to the autonomic unit, which
consists of a digitizer, a signal processor, a network interface, and a controller, as shown in Figure 3.
In fact, the autonomic unit is divided into two units:
an autonomic digital signal processing unit (ADSP
unit) and a digitizer subunit. We are now develop-

With the ubiquitous concept, we are trying to develop a new DAQ system for nuclear physics experi∗1∗2

Research Center for Nuclear Physics, Osaka University
Center for Nuclear Study, University of Tokyo

Fig. 2. A ubiquitous detector can be used by simply plugging cables.

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RIKEN Accel. Prog. Rep. 40 (2007)
Table 1. Specifications of the ADSP unit: EP101.
CPU
Clock
MemoryNonvolatile memory
Network interface
Digital I/O to subunit
OS
Power
Size
Fig. 3. Basic idea of the autonomic unit. This block diagram is similar to that of a digital oscilloscope.

ing a FADC unit1) and multichannel photon counting
unit for the digitizer subunit as well as the ADSP unit.
3

Autonomic digital signal processing unit
(ADSP unit)

The ADSP unit is the most important unit on
the ubiquitous detector, because it functions as thebrain of each detector. Figure 4 and Table 1 show aphoto and the specifications of the ADSP unit (model:
EP101). The DAPDNA chip2) has a unique architecture of a two-dimensional array of 376 32-bit processing
elements, which is good for digital signal processing
operations, e.g., waveform analysis or making a histogram. The 512 MB of memory can hold more than 2
sec of 100 MHz 16-bit FADC waveform data. It gives
a good margin to wait for delayed trigger signals. The
2 MB of Flash-ROM is used to store the detector’s
characteristics and history, e.g., calibration data.
Now, we are testing the ADSP unit as a stand-alone
component. The following is a list of items that havebeen already confirmed:

Fig. 4. A photo of ADSP unit: EP101. The largest chip isa DAPDNA, that is the heart of a ADSP unit. 128-bit
digital I/O and 512 MB DDR-SDRAM are placed at
the back.

2- 194 -DAPDNA-2
166 MHz512 MB DDR-SDRAM
2 MB for user (FlashROM)
100BaseT
128 bits : 166 MHz SSTL 2
AxLINUX
5 V, 1 A
100 mm x 150 mm• Booting of AxLINUX• Use of Ethernet• Use of TCP/IP communication (remote login,
http, NFS)
• Running applications on AxLINUX• Reading/Writing data in SDRAM from DNA processor elements
We will start testing the ADSP unit and FADC subunit as a connected module soon.
References
1) H. Baba et al.: In this report.
2) DAPDNA chip, IPFlex Inc. http://www.ipflex.com/

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4040 (2007)(2007)Development of FADC unit for UBIQUITOUS detector system
H. Baba, M. Kurokawa, Y. Watanabe, T. Fukuchi,∗1 S. Shimoura,∗2 S. Ota,∗2 T. Ebisuzaki, T. Hamada,K. Hirota, Y. Kawasaki, H. Sato, H. M. Shimizu, Y. Takizawa, and T. Motobayashi
A FADC unit for the UBIQUITOUS detector system1) has been developed. The FADC unit is a subunit of an autonomic digital signal processing (ADSP)
unit. FADC, which stands for flash analog-to-digitalconverter, can acquire the waveforms of analog signals
because its conversion time is sufficiently short. In thiswork, a 100-MHz-sampling-rate FADC with 14-bit resolution was employed. It can digitize an analog signal
every 10 ns with 14-bit resolution. The digitized waveform signal is sent to the ADSP unit for further analysis to extract physical values, e.g., energy, timing, position, and particle identification. The detector system
will be applied to the output signals from a NaI(Tl) detector2) , a Ge detector3) , a CdTe detector 4) and a Si
detector5) . The FADC unit works without a break andcontinuously sends waveform data to the ADSP unit,
which also works continuously with pipeline processing. Therefore, by combining these units, the resulting
detector system will have the capability of dead-timefree analog to physical value conversion.
The specifications of the FADC unit are listed below.

Gain Amp. 1
Input 1
FPGA
Ramp
FADC
Input 2– 120 pin, 1/4 inch pitch, SMT plug
– Total 60 bits/sample∗ FADC: 14 bits/sample × 2∗ Clock counter: 16 bits/sample × 2– SSTL 2 Class II logic signal– 2 × LEMO connectors– 1 k / 50 Ω impedance (with the gain amplifier)– 50 Ω impedance (with the ramp circuit)• Power consumption– 5 W (+5 V, 1 A)
• Size and weight• Analog signal processing– 100 × 150 mm– 150 g– 2 × Gain amplifiers– 1 × Ramp circuit∗ Input: NIM negative logic signal∗ Output: 5 mV/ns triangular signal• Digitizer– 2 × FADCs∗ 100 MHz sampling rate
∗ 14 bit resolution∗ ±1 V input range– 2 × Clock counters∗ 16 bit resolution∗ Debugging purpose only
• Outputs∗1∗2

Research Center for Nuclear Physics, Osaka University
Center for Nuclear Study, University of Tokyo

Gain Amp. 2

Fig. 1. Photograph of FADC unit. The details of this
FADC unit are described in a text.

• Inputs∗ Programmable gain
∗ Course gain: ×1 – ×128 (8 steps)∗ Fine gain: ×0.4 – ×1 (8 steps)

DC input

Figure 1 shows a photograph of the FADC unit. The
FADC unit has two input connectors. One of them isconnected to the gain amplifier. The other is connectedto the gain amplifier or ramp circuit, which are selectedby a jumper switch. The input range of the FADC chipis ±1 V. To adjust the full-scale range, input signals
are amplified by the gain amplifier. Their amplitude iscontrolled by the ADSP unit. If we try to obtain timing information from NIM logic signals with the 100MHz FADC, the extracted timing will have the same
ambiguity as the sampling interval of 10 ns. In orderto achieve a good timing resolution on less than thenanosecond order from logic signals, the ramp circuit
is implemented. This ramp circuit generates triangular signals whose width and pulse height are proportional to the width of input NIM logic signals. Timing
information will be derived by a linear extrapolationof the digitized triangular signals. In order to implement the clock counter, field programmable gate array(FPGA) is mounted. The clock counter counts clock at
100 MHz. It will be used for debugging purposes only.

- 195 1

RIKEN Accel. Prog. Rep. 40 (2007)

Fig. 2. The operation of the ramp circuit. Ramp signal(lower triangular signal) is generated according to input
NIM logic signal (upper rectangular signal).

The power consumption of the FADC unit is about 5
W (5 V, 1 A). The FADC unit can provide power tothe ADSP unit that power consumption is also about
5 W (5 V, 1 A).
We are going to connect the FADC unit with an
ADSP unit and implement digital signal processing fordetector signals.
References
1) Y. Watanabe et al.: This report.
2) H. Baba et al.: CNS Annual Report 2004 (2005) 87.
3) T. Fukuchi et al.: CNS Annual Report 2004 (2005) 73.
4) T. Moriguchi et al.: CNS Annual Report 2005 (2006)75.
5) M. Kurokawa et al.: This report.

2- 196 -

RIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4040 (2007)(2007)RIKEN

CCJ operation in 2005-2006
S. Kametani, H. En’yo, Y. Goto, H. Hamagaki,∗1 T. Ichihara, Y. Watanabe and S. Yokkaichi
RIKEN PHENIX Computing Center in Japan(RIKEN CCJ) is a large-scale computing system
mainly dedicated to the analysis of RHIC-BNL1)
physics: the study of the spin structure of a nucleon
and the investigation of QGP. The production of Data
Summary Tape (DST) from raw data in the PHENIX2)
experiment, one of two major experiments being performed at RHIC, and the subsequent analysis are performed at CCJ. In this article, we report on the following three activities: the operation, upgrade and maintenance of CCJ.
CCJ is composed of calculation nodes, a massstorage system, a medium-scale storage system using
RAID and a networking system that connects thesecomponents to each other. CCJ owns 150 calculation
nodes. In addition, 128 nodes of the RIKEN Super
Combined Cluster (RSCC) of the Advanced Centerfor Computing and Communication3) are dedicated to
CCJ. These CPU resources are allocated to jobs byLSF4) , the batch-job system of Platform Inc.
The mass-storage system is composed of a taperobotic system and disks, and is managed by theHigh Performance Storage System (HPSS)5) . CCJ
and RSCC share the mass-storage system. As of
Dec. 2005, the mass-storage system had a total volume of 0.8 PByte using 4000 tape cartridges, each witha 200 GByte capacity, and the total capacity of themedium-scale storage system was 47 TByte. The detailed specifications can be found in the previous report6) .
During 2005-2006, CCJ experienced two major programs. The first one was the transfer of PHENIX raw
data in the PHENIX year-6 experiment. In the experiment, the recorded data are stored in buffer disks
and then transferred to a mass-storage system at BNL.
In parallel with this, data in the buffer disks are alsotransferred to RIKEN. The transferred data are not
only archived as a backup, but are also used to produce the PHENIX official DST.
In the beginning of the year-6 experiment,
700 TByte of data space was used to store the dataof the previous (year-2/3/4/5) experiments, i.e., only
100 TByte of space was left on the mass-storage system. We purchased 1000 tapes (200 TByte). We also
returned 300 tapes located at BNL back to RIKEN,
which were reserved for airplane data transfer. The
data transfer between BNL and RIKEN was carriedout using GridFTP7) , the same method at last year8) .
Figure 1 shows the amount of data transferred from
BNL to CCJ. The amount of transferred data was 4∗1

Center for Nuclear Study, Graduate School of Science, theUniversity of Tokyo

7 TByte each day. This amount corresponds to 3070 MByte/sec in transfer speed. A total of 310 TByte
of data were transferred over about 2 months during
the experiment.
The second major program was the reproduction of
DST for the year-5 experiment. DST is the first calibrated data set on which all the PHENIX collaborators
perform physics analysis. A detailed description of thisprogram can be found in this volume9) . The production began at Apr. 2006 and ended at Sep. 2006.
To support the DST production, change of the operating system of calculation nodes was performed tofollow up the PHENIX analysis framework. ScientificLinux 3.0.5 was installed to 152 hosts of CCJ computing servers including RSCC.
Figure 2 shows the amount of data stored in HPSS
over time. As a result of the raw data transfer and
DST production, the total amount of data stored in
HPSS reached 1.1 PByte.
Other analytical activities can be found on the
web page: http://ccjsun.riken.go.jp/ccj/proposals/.
Achievements of these activities are reported in thisvolume.
Our activity in the system upgrade was mainly focused on the establishment of new storage spaces. In
the mass-storage system, a new tape drive was installed in Aug. 2006 because the physical space used
to store the tape cartridges of the robotic system wasalmost full. Therefore, the tape cartridges needed tobe replaced by larger ones. We introduced a T10000
tape drive of Sun Microsystems. T10000 can handle
500 GByte tape cartridges, whereas the previous tapedrives (T9940B) could handle only 200 GByte tape cartridges. For the operation of T10000, a version upgradeof the HPSS system from 4.2 to 6.2 was also performed.
We purchased 160 of the 500 GByte tape cartridges andobtained an extra storage space of 80 TByte as a result. The installation of T10000 was executed during
Aug. 2006. The data repacking from 200 GByte tapes
to 500 GByte tapes is now ongoing. We are planningto purchase an additional drive and tape cartridges.
We decided to establish a contract with San Diego
Supercomputer Center for the maintenance of HSI and
HTAR, the advanced tools of HPSS. The standard toolof HPSS, called ”pftp”, performs random access when
multiple files are specified. The poor random access iswell-known weak point of tape media. HSI and HTAR
have an optimizing function for accessing tape media,
to mitigate this weak point.
The medium-scale storage system was also upgraded. First, an additional RAID system was installed in May 2006. The capacity of the additional- 197 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

References
1) M. Harrison, T. Ludlam and S. Ozaki: Nucl. Instrum.
Meth. A 499, 235 (2003).
2) D. P. Morrison et al.: Nucl. Phys. A 638, 565c (1998).
3) http://accc.riken.jp
4) http://www.platform.com/products/LSF/5) http://www.hpss-collaboration.org/hpss/index.jsp
6) S. Kametani et al.: RIKEN Accel. Prog. Rep. 39, 224(2006).
7) http://www.globus.org/grid software/data/gridftp.php

2- 198 -

Fig. 1. The amount of data transferred each day to CCJ are
shown by gray bars. The cumulative amount is shownby the solid line.

1.4

Stored Data (PByte)

RAID is 10 TByte. A Sun Fire V40 machine was installed as the corresponding server. Since Solaris10 forx86 does not support pftp, the server is operated by
Scientific Linux 4.2.
Moreover, a new storage system is being tested as
the successor of the RAID system. We installed a
300 GByte HDD in each of 36 CCJ calculation nodes.
The total disk space reached 10.8 TByte. There are
two merits of this system compared with the existing
network server-client systems. The first merit is thecost reduction. The second merit is the improvementof the data supply speed to the CPU. In the existing
systems, data to be analyzed on the client computer istransferred from servers via the network. The load on
the data server increases as the number of the clients
increases. This phenomenon results in a bottleneck in
our current system. In the new system, a job is allocated to the computer, which stores the data to beanalyzed. As a result, the accumulation of the loadon disk servers never occurs and the total computing
speed improves. We plan to apply the system to RSCC
nodes, which are dedicated to CCJ.
The maintenance issues during 2005-2006 are listed
below. A version upgrade was performed for LSF (5.1
to 6.0) in Dec. 2005. The RAID system had trouble on HDD and FC HUB. The replacement of brokenparts already has been carried out. Five computing
servers crashed and four of them recovered with thereplacement of the HDD. One CPU of a NFS server
broke and was replaced. Two exhausted Sun serversthat served several system services are retired. The
services served by these hosts were integrated into themain NFS server. Two air conditioners in the CCJ
server room broke and were repaired. At the sametime, the air conditioners stopped because of the dirtin the outdoor unit.
Here, we report on the security of the network. The
security policy of BNL was tightened during 2006.
First, since Oct. 2006., we can only have SSH accessto the RHIC Computing Facility (RCF)10) when using
a public key for authentication. RCF accepts only one
public key per user. Therefore, for the connection between CCJ and RCF, a user needs to put their private
key into the CCJ machine or to use agent-forwarding
method from CCJ. In each case, the responsibility of
CCJ for the management of security has become heavier.

1.2

TOTAL
Raw06

1.0

DST

0.8
0.6
0.4
0.2
0.0
Apr, Oct, Apr, Oct, Apr, Oct, Apr, Oct, Apr, Oct, Apr, Oct,
2001 2001 2002 2002 2003 2003 2004 2004 2005 2005 2006 2006

Fig. 2. The amount of data stored in HPSS over time.
Closed circles show the total amount used. Open diamonds show the amount of raw data transferred during
the year-6 experiment. Closed triangles show the cumulative amount of DST data produced from the datain the year-2/3/4/5 experiments. The total amount ofdata stored in HPSS reached 1.1 PByte.

8) Y. Watanabe et al.: RIKEN Accel. Prog. Rep. 39, 222(2006).
9) Z. You et al.: RIKEN Accel. Prog. Rep. 40 (2007).
10) http://www.rhic.bnl.gov/RCF/

RIKEN Accel. Prog. Rep. 40 (2007)

Network and Computing Environment for RIKEN Nishina Center
T. Ichihara, Y. Watanabe, K. Yoshida, and A. Yoshida
We have been operating Unix/Linux NIS/NFS cluster systems at Nishina Center so far. The central serverused for general computing and the mail service was
RARFAXP. Four sets of 64 bit Alpha EV6 CPUs with
2 GB memory are used for RARFAXP and the operating system is Tru 64 UNIX (OSF/1). However, thedevelopment of Alpha CPU was discontinued and support of the Tru 64 operating system is scheduled to bediscontinued soon. In addition, several new software
packages cannot be installed on Tru 64 UNIX because
they can no longer run on the operation system.
Therefore, we have replaced the RARFAXP serverby two servers, RIBF and RIBF00 this year 1) .
Both new servers are HP ProLiant 585 high-reliability
servers, equipped with AMD dual-core Opteron 885
CPUs of 2.6 GHz. RIBF consists of four CPUs (8cores) and 16 GB memory, while RIBF00 consists of
two CPUs (4 cores) and 8 GB memory. Power supplies and fans are duplicated for high availability. System disks are striped and mirrored (RAID0+1) by the
hardware.
RIBF is used for the mail server and the NFS server
for the user home directory. RIBF00 is a ssh login server and a general-purpose computational server.
Scientiﬁc Linux 4.4 (X86 64)2) operating system has
been adopted for these new servers. Scientiﬁc Linux isfreely available and widely used in the nuclear physics
and high-energy physics communities.
At RIBF, Postﬁx3) is used for mail transport software and Dovecot4) is used for imap and pop services. These software packages enable secure and reliable mail delivery.
A new 3.3 TB ﬁber-channel Raid was connected to
RIBF for the user home directory. Half of the RAID
is used as backup area. This RAID controller is duplicated for high availability.
Figure 1 shows the current conﬁguration of theLinux/Unix servers of Nishina Center. RARFLX1,RARFLX2, and RARFLX3, which have also been replaced in this year, are located in the 1F counting roomof Nishina Memorial Buildings, and they are used asuser terminals for experiments at the Ring cyclotron.
Dual-core AMD Athlon 64X2 CPUs are used for thesenodes.
RARFSMTP and RARFSMTP2 are mail front-end
servers used to tag spam mails and isolate virusinfected mails. Spamassassin5) software is used to
identify spam mails.
An anonymous ftp server ftp.riken.jp is managed andoperated at RIKEN Nishina Center. Recently, many
research laboratories in Nishina Center have adopted
Linux as their computer operating system. To conduct

N ishina LIN UX server (SL4.4 x86_64)
1.6TB x2 (hom e)/rarf/u/rarf/u-backup

16GB
RIBF
4 CPU (8 core)server (pop3,im ap)

O pteron 885 2.6GHz x4 M ail
8GB
RIBF002 CPU (4 core)

Internetlogin server
Generalserver

O pteron 885 2.6GHz x2

10TB FC-FC

RIBFD A TA 01 8GB
2 CPU (4 Core)

10GbpsO pteron 880 2.4GHz x2

RA RFLX10 (1U)
2 CPU (2 core)server (data disk)

Scientific Linux 4.4
X86_64 (64bit)

RA RFLX20 (1U)
2 CPU (2 core)
Gigabit
Sw itchRA RFLX1
RA RFLX2RA RFLX3
RA RFSUN
Solaris 8

Gatew ay to private LA N
Printer server

RA RFA XP/rarf/u-old

Tru 64 UN IX
RA RFA X1/2

UN IX cluster (old system )RA RFW W W w w w .nishina.riken.jp
Linux SL4.4
indicoO pteron 285x1
RA RFProxy
Linux SL4.4 BIN D server
RA RFSM TP2 M ailGatew ay
Linux SL4.4 Spam A ssassin
RA RFSM TP
Linux SL4.4
A nti-V irus
8 TB Raid
ftp.riken.jp
Linux SL4.4

A nonym ous
ftp/http server

Fig. 1. Configuration of the Linux/Unix server.

the installation and daily management of Linux easily
and eﬃciently, major Linux distributions are mirroredat the ftp servers.
Most of the users of Nishina Center have e-mail addresses of the following forms:
username@ribf.riken.jp or username@riken.jp.
The former one represents an e-mail address of
the Nishina Center mail server (RIBF) and thelatter represents an e-mail address of the RIKEN
mail server (postman). Mail to the previous Email addresses of username@rarf.riken.jp and username@rarfaxp.riken.jp are forwarded to the new mailaddress username@ribf.riken.jp automatically.
Two sets of a Dual-core Opteron 1U server and a
6TB SATA Raid system have been installed as a prototype DAQ event builder and analyzer for RIBF experiments.
References
1) http://ribf.riken.jp/
2) https://www.scientificlinux.org/
3) http://www.postfix.org/
4) http://www.dovecot.org/
5) http://spamassassin.apache.org/- 199 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Comparison of Single-Event Burnout tolerance of space-use power MOSFETs
N. Ikeda, S. Kuboyama, Y. Sato,䟼1 H. Ohira, H. Otomo, O. Shimada, H. Ozono,䟼2 N. Inabe, and M. Kase

䟼1
䟼2

VDS=100V

Counts (a.u.)

VDS=90V

VDS=80V

VDS=50V

VDS=10V

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

Collected Charge (pC)(a) MOSFET from JAXA

2nd peak
VDS=100V

VDS=90V
Counts (a.u.)

A power
metal-oxide-semiconductor
field-effecttransistor (MOSFET) is a key device in a power circuit thathas a low ON-resistance and a fast switching. A MOSFET
for use in space is required to have radiation hardness.
Protons, heavy ions and other particles in space may havesingle-event effects that may lead to semiconductor device
malfunction or failure. Single-event burnout (SEB) is themain concern for power MOSFETs. SEB is triggered by aheavy ion passing through a device when it is off. A
transient current induced by such an ion turns on a parasitic
bipolar transistor, which results in the burning out of adevice and its possible destruction1). Because commercial
power MOSFETs are not SEB-tolerant and SEB occurs at
voltages far below rated voltages, MOSFETs particularly
developed for space application must be used.
Japan Aerospace Exploration Agency (JAXA) started
developing radiation-tolerant power MOSFETs several
years ago and successfully completed the development ofseveral types of SEB-free power MOSFET with low
ON-resistance. MOSFETs with drain-source voltage (V DS)
values between 100 V and 250 V were developed andproven to be SEB-tolerant at rated voltages up to a linear
energy transfer (LET) of 48 MeV/(mg/cm2). Because there
is another organization developing space-use power
MOSFETs, an irradiation test was conducted to compare
the radiation tolerance of MOSFETs from JAXA and theorganization using RIKEN Ring Cyclotron. MOSFETs with
VDS=100V were irradiated with 373 MeV 58Ni19+ ionswhose LET and projected range in the devices were 25
MeV/(mg/cm2) and 61.3 µm, respectively. The Energetic
Particle Induced Charge Spectroscopy (EPICS) systemdeveloped by JAXA was used to observe SEB2), and thespectra of collected charges were examined in the samemanner as in a previous study3). Typically, two peaks wereobserved in the spectra, which are designated here as thefirst peak and the second peak. A large charge collection in
the second peak implies a low SEB tolerance.
Figure 1 shows the spectra of collected charges of the
MOSFETs. Although no SEB was observed for bothdevices, a difference in EPICS spectra was observed.
Whereas small second peaks with small collected charges
were observed for MOSFETs from JAXA, apparent second
peaks with large collected charges were observed for the
MOSFET from the other organization. This result suggeststhat MOSFETs from JAXA have better radiation tolerance.
Moreover 200 V and 250 V devices were irradiated under
the same conditions and the experiment showed that
MOSFETs from the other organization have a thicker active
layer, which provides a higher ON-resistance.

VDS=80V

VDS=50V

VDS=10V
1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+05

Collected Charge (pC)(b) MOSFET from another organization

Fig. 1. EPICS spectra of MOSFETs. “x”is the maximum
collected charges.

References
1) JAERI and NASDA Joint Research Report, 2 (1999), p. II-9
2) S. Kuboyama et al.: IEEE Trans. Nucl. Sci., 39 (1992), pp 1698
3) N. Ikeda et al.: RIKEN Acce. Prog. Rep., 37 (2003), pp 98

Japan Aerospace Exploration Agency
Ryoei Technica Company- 201 -㻑㻃
RIKEN Accel. Prog. Rep. 40 (2007)

Synthes is of Pd-A u nano particle s by GeV io n irradiatio n
N. Maeda*1, F. Hori*1, T. Kambara, T. Abe䚮H. Ryuto and㻃 A. Iwase*1
In a previous paper, we showed that GeV heavy ion
irradiation reduces Au ions in aqueous solutions andsynthesizes Au nanoparticles, the diameter of which was
about 10-50 nm1, 2). In this report, we show the result of 1.6
GeV carbon ion irradiation to the solutions containing Au
and Pd ions.
Samples were dilute aqueous solutions with 0.5 mM
NaAuCl4/2H2O as a precursor of Au3+ ions, 0.5 mM
PdCl/2NaCl/3H2O as a precursor of Pd2+ ions, and 8 mM
sodium dodecyl sulfate (SDS) as a surfactant. The samples
were sealed in polystyrene vessels and irradiated with 1.6
GeV full-stripped carbon ions at the E5B beam line of the
RIKEN ring cyclotron accelerator. The irradiation doses
used were 300, 1500, 5000 and 10000 Gys. After theirradiation, the optical absorption spectra of each solution
were
measuredusing
anultraviolet-visible
spectrophotometer (UV-vis).
The solution remained  yellow, indicating theexistence of Au and Pd ions at irradiation doses below 300
Gy. When the dose reached 1500 Gy, the solution turned
reddish violet. For doses higher than 1500 Gy, the solution
showed a dark brown color. Figure 1 shows the change in
UV-vis spectra with the dose of carbon ion irradiation. The
UV-vis absorption peak around 300 nm originates from Au
and Pd ions in an unreduced solution. After the irradiationof 1500Gy, an absorption peak around 530 nm, whichcorresponds to the surface plasmon peak of Au
nanoparticles, appears, and the absorption yield of Au andPd ions decreases.

With increasing carbon irradiation dose, thebackground of the absorption yield increases and theyield around 530 nm decreases. The dependence of theabsorption yield around 530 nm on the dose of carbon
irradiation can be observed more clearly in Fig. 2. As theincrease in the background of the absorption yield isconsidered to be due to the surface plasmon of Pd, thepresent result can be explained as follows: 1.6 GeV
carbon ion irradiation reduces Au ions first and Au
nanoparticles are produced. After the production of the
Au nanoparticles, Pd ions are reduced on the surfaces of
the Au nanoparticles. Since the surfaces of the Au
nanoparticles are coated with Pd atoms, the Au surface
plasmon peak intensity (around 530 nm) decreases withincreasing carbon irradiation dose. The present
experiment suggests the possibility of synthesizing
nanoparticles with Au cores and Pd shells by GeV ion
irradiation. To confirm the structure and the size of
Pd-Au nanoparticles synthesized by GeV carbon ion
irradiation, transmission electron microscopy observation
is now in progress.
40

30

20

2
0Gy
300Gy
1500Gy
5000Gy10000Gy

10

0

0

2000

4000

6000

8000

10000

Dose of carbon ion irradiation, !/Gy

1

Fig. 2 Dependence of UV-vis absorption yield around 530
nm on dose of 1.6 GeV carbon ion irradiation.
0

300

400

500

600

References

700

Wavelength, ! /nm

Fig. 1. Change in UV-vis spectra with dose of 1.6 GeV
carbon ion irradiation.
䟼11) N. Maeda, T. Hiroki, F. Hori, S. Okuda, R. Taniguchi, T.
Kojima, T. Kambara, T. Abe, and A. Iwase: Mater. Res. Soc.
Symp. Proc. Vol. 900E, 0900-O06-16. 1-6.
2) N. Maeda, F. Hori, T. Kambara, T. Abe, and A. Iwase: RIKEN
Accelerator Progress Report 2005.

Osaka Prefecture University- 202 -

RIKEN Accel. Prog. Rep. 40 (2007)
57

Fe diffusion in Si after GeV- implantation of 57Mn

Y. Yoshida＊1, Y. Kobayashi, K. Yukihira＊1, K. Hayakawa＊1, K. Suzuki＊1,
A. Yoshida, H. Ueno, A. Yoshimi, K. Shimada＊2, D. Nagae＊2, K. Asahi, and G. Langouche,＊3
The process must be related to the recovery processes
from the nonequilibrium state to the equilibrium state of
the Si lattice around the 57Fe nuclear probes.
References
1)
A. Istratov, H. Hieslmair and E. R. Weber; Appl. Phys.
A69, 13 (1999).
2)
H. P. Gunnlaugsson, G. Weyer et al.; Appl. Phys. Lett. 80,
2657 (2002).
3)
Y. Yoshida; in ALTECH 2003 Analytical and Diagonistic
Techniques for Semiconductor Materials, Devices, andProcesses, 479 (2003); Y. Kobayashi, Y. Yoshida et al.;Hyperfine Interactions, 126, 417（2000）; Y. Yoshida, K.
Kobayashi et al.; Defect and Diffusion Forum 194-199,
611 (2001).
4)
Y. Yoshida, Y. Kobayashi, K. Hayakawa, K. Yukihira, A.
Yoshida, H. Ueno, F. Shimura and F. Ambe; Physica B,
376-377, 69 (2006).
5)
Y. Yoshida, S. Ogawa and K. Arikawa; Physica B,
340-342, 605 (2003).
6)
Y. Yoshida, S. Horie, K. Niira, K. Fukui and K.
Shirasawa; Physica B, 376-377, 227 (2006).
102

1200K

×2
100
102

Normalized counts

Iron impurities are known to degrade seriously theelectronic properties of silicon-based devices and solar
cells. Dilute systems of FeSi, therefore, have been
intensively investigated for more than 50 years bydifferent experimental techniques including 57Fe
Mössbauer spectroscopy. Generally, iron atoms arethought to occupy only the interstitial sites in siliconleading to a fast diffusion.1) On the other hand,substitutional iron atoms were not found experimentallyby standard evaluation techniques, although Mössbauer
spectroscopy provided clear lines of evidence for
substitutional iron atoms not only after the implantationof 57Fe into Si matrix, 2-4) but also after the depositionand subsequent thermal diffusion of 57Fe into Si. 3,5,6)
The present investigation is carried out to clarify the
impurity diffusion of Fe atoms and the formation
processes of “substitutional Fe atoms” in Si at hightemperatures.
57
Mn nuclei were produced by the nuclear projectile
fragmentation of 58Fe21+ primary beam (E = 63
MeV/nucleon) with a Be target, and subsequently
separated by an on-line isotope separator, RIPS.
Mössbauer spectra of 57Mn/57Fe in n-type CZ-Si were
measured between 300 and 1200 K immediately after
the implantation of the radioactive isotope of 57Mn
(τ1/2=1.45m). The implantation was performed throughan aluminum foil with a thickness of 200 μm, so that the57
Mn probes stopped at approximately 200 μm from thesurface of the Si sample. The total fluence of 57Mn was
2×1012 57Mn/cm2 typically for one spectrum.
The spectra from 300 K to 700 K can be fitted by two
Lorentzians corresponding to Fe atoms at interstitial andsubstitutional sites. The interstitial fraction decreases
markedly at about 600 K. The results are in good
agreement with those of previous experiments. 3,4) On
the other hand, the spectra from 800 K to 1200 K (Fig.
1), which are successfully obtained for the first time,
can be analyzed only by a broad singlet. The total area
decreases up to 800 K with increasing temperature, as
expected from a Debye model. The area, however,suddenly decreases at 900 K and 1000 K, but increases
again at 1100 K. The center shift of the substitutional
component shows a strong deviation from thesecond-order Doppler shift in the temperature region
between 600 K and 1000 K.
The relaxation behaviors observed in the present
experiment can be interpreted in terms of adiffusion-reaction process of interstitial Fe atoms withvacancies within the time scale of 100 ns, leading to theformation of substitutional Fe atoms in the Si matrix.

1100K

×2
100
102

1000K

×2
100
102

900K

×2
100
102

800K

100
-4

-3

-2

-1

0

1

2

3

4

-1

Velocity / mms

Fig. 1. Mössbauer spectra of 57Mn/57Fe in n-type Si measured
from 800 K to 1200 K. Notice that the vertical scale for the
spectrum at 800 K is different from those for the others.

＊1

Shizuoka Institute of Science and Technology, Japan
Department of Physics, Tokyo Institute of Technology＊3
Institute for Nuclear and Radiation Physics,
Physics Department, Leuven, Belgium＊2- 203 -

RIKEN Accel. Prog. Rep. 40 (2007)
99

Ru Mössbauer spectroscopic studies of SmRu4P12 †S. Tsutsui,∗1 Y. Kobayashi, T. Okada, H. Haba, H. Onodera,∗2 Y. Yoda,∗1 C. Sekine,∗3 I. Shirotani,∗3 D. Kikuchi,∗4
H. Sugawara,∗5 and H. Sato∗4

SmRu4P12 is one of the attractive compounds among
filled skutterudites. Its electric resistivity shows ametal-insulator transition at TMI = 16 K similar to that of theisomorphous PrRu4P12. The specific heat measurement with
an applied magnetic field suggests that successive
transitions occur around TMI. The magnetic susceptibility of
SmRu4P12 shows a cusp around 14 K, suggesting anantiferromagnetic ordering. The successive transitions were
initially
ascribedtoantiferroquadrupoleandantiferromagnetic orderings, since the entropy at TMIreached Rlog 4 and the magnetic phase diagram was similar
to that of Ce1−xLaxB6. However, the recent results obtainedby macroscopic methods, such as those used in ultrasoundexperiments, have suggested the possibility of the transition
being due to magnetic octupole ordering instead of thequadrupole ordering. The clear jumps of the specific heat
and antiferromagnetic-like temperature dependences of themagnetic susceptibility in SmRu4P12 resemble those in
NpO2, which is a typical system showing the octupoleordering.
We have carried out the X-ray absorption spectroscopy,
149
Sm nuclear resonant forward scattering, and 99Ru
Mössbauer spectroscopy of SmRu4P12. X-ray absorption
spectra indicate that Sm ions are trivalent up to 14 K.
Quantum beats due to magnetic dipolar ordering are
observed at 4.5 K in the 149Sm nuclear resonant forward
scattering. The temperature dependence of time-integrated
intensity in the 149Sm nuclear resonant forward scatteringsuggests that the magnetic dipolar ordering occurs
immediately below the metal-insulator transition
temperature. We have also carried out 99Ru Mössbauer
spectroscopy. The source nuclide 99Rh (T1/2 = 15.0 d) was
prepared by the 99Ru(p,n)99Rh reaction with 12 MeV
protons accelerated by the AVF Cyclotron.
The 99Ru Mössbauer spectra of SmRu4P12 obtained at 5
and 77 K are shown in Fig. 1. The spectra could beanalyzed satisfactorily with typical doublets in the absenceof a magnetic field. This implies the absence of transferred
hyperfine interactions or the accidental cancellation oftransferred hyperfine interactions at the 99Ru nuclei. The
present result suggests a magnetic ordering accompanied bya magnetic dipole moment at the metal-insulator transition
temperature in SmRu4P12 in spite of the proposal of themagnetic ordering accompanied by a Tβ-type octupole.

Fig. 1. 99Ru Mössbauer spectra of SmRu4P12 at 77 and 5 K.

† Condensed from the article in J. Phys. Soc. Jpn., 75 (2006) 093703.
*1 Japan Synchrotron Radiation Research Institute (SPring-8)*2 Graduate School of Science, Tohoku University*3 Department of Electric and Electronic Engineering, Muroran Instituteof Technology*4 Department of Physics, Tokyo Metropolitan University*5 Faculty of Integrated Arts and Sciences, University of Tokushima.

- 204 -

RIKEN Accel. Prog. Rep. 40 (2007)

Continuum luminescence of α-alumina under heavy-ion irradiation
M. Koshimizu*, K. Kimura, H. Ryuto, K. Asai*, and M. Kase

* Department of Applied Chemistry, Graduate School ofEngineering, Tohoku University

0.08
0.07
intensity (a.u.)

0.06
0.05
0.04
0.03
0.02
0.01
0
150

160

170

180

190

200

210

220

wavelength (nm)0 ns0.15 ns

0.3 ns1.2 nsFig.1 Time-resolved luminescence spectrum of α−alumina
irradiated with Xe ions at 3.3 K.
1.00E-02

intensity (a.u.)

Fast processes occurring along an ion trajectory are known to be
characterized by high-density electronic excitation. Permanent
irradiation effects, particularly, the formation of an ion track,should be profoundly related to these processes, e.g., interaction
among excited states at a high density or that between excitedelectrons and a lattice system. We have been concerned mainly on
the involvement of the self-trapping of charge carriers or excitonsin track formation. This involvement has already been reported1);
however, there have been few experimental reports regarding this.
In this report, we present a study of α-alumina luminescence underheavy-ion irradiation, for which there have been many
experimental reports on luminescence properties in a
VUV-UV-VIS region under X-ray or electron irradiation2,3).
One of the authors (K. K.) has already reported thetime-resolved luminescence spectra of α-alumina under heavy ion
irradiation4) and found an ultrafast luminescence band in a UV
region. Also, we have reported that the decay rate of theluminescence band in the VUV region increases with increasing
excitation density5). In both cases, the ultrafast decay of theluminescence band under high-density excitation has been
ascribed to the large oscillator strength of the collective excitedstates analogous to the electron-hole plasma in semiconductors6).
In this report, we focus on the luminescence between the twoluminescence bands in the UV and VUV regions indicated above.
The measured sample was a single crystal of α-alumina. The
sample was irradiated with Xe ions at an energy of 2.0
MeV/nucleon at 3.3 K. Time-resolved luminescence spectra wereobtained by a single-photon counting method. The time resolutionof the entire measuring system was smaller than 100 ps.
The time-resolved luminescence spectrum of the α-alumina
irradiated with Xe ions is shown in Fig.#1 In addition to theprominent luminescence band at about 170 nm, luminescence
continuum exists at a longer wavelength into the UV region, where
no fast luminescence band is observed for low-density excitation.
The decay curve of the luminescence intensity at 219.4 nm is also
shown in Fig.#2. It is clearly seen that the decay curve of theluminescence continuum can be described with a single
exponential decaying function convolved with the resolutionfunction and that its lifetime is as short as about 100 ps. This
continuum prevails over the UV region toward the luminescencepeak in the UV region reported previously4).
The possible origin of the continuum is described as follows.
Because the lifetime of the continuum is similar to the fastcomponent of the UV and VUV bands, it is natural to consider thatthe origin of the continuum is the same as that of the bands, i.e.,the high-density electron-hole pair analogous to the electron-hole
plasma in semiconductors. In addition, no intrinsic luminescenceband has been observed in this wavelength region. Here, we
propose the hot luminescence of the collective excitation state as apossible origin. In the case of low-density excitation under X-ray

1.00E-03

1.00E-04

1.00E-05
1000

2000

3000

4000

5000

6000

time (ps)Fig.2 Decay curve of luminescence intensity at 219.4 nm.
or electron irradiation, luminescence occurs at the energy minima
in the configuration coordinate, which leads to the discreteluminescence bands in the UV and VUV regions. In contrast, inthe case of high-density excitation under heavy-ion irradiation,
because of the short luminescence lifetime, luminescence occurs
even at states other than the energy minima in the configuration
coordinate before relaxation to the minima, which leads to theluminescence continuum.
References
1) N. Itoh and A.M. Stoneham, Nucl. Instrum. Methods Phys. Res.
B 146, 362 (1998).
2) J. Valbis and N. Itoh, Radiat. Eff. Defects in Solids 116, 171(1991).
3) M. Kirm, G. Zimmerer, E. Feldbach, A. Lushchik, Ch. Lushchik,and F. Savikhin, Phys. Rev. B 60, 502 (1999).
4) K. Kimura, J. Kaneko, S. Sharma, W. Hong, and N. Itoh, Phys.
Rev. B 60, 12626 (1999).
5) M. Koshimizu, K. Kimura, H. Ryuto, K. Asai, and M. Kase,
RIKEN Accel. Prog. Rep. 39, 94 (2005).
6) C. Klingshirn and H. Haug, Phys. Rep. 70, 315 (1980).

- 205 -

RIKEN Accel. Prog. Rep. 40 (2007)

Ultra-short-pulse continuum of ion trac k:
Release of spec tral missing in alkali halides
Kazuie Kimura, Masanori Koshimizu*1, Hiromichi Ryuto, Keisuke Asai*1, and Masayuki Kase
Heavy-ion irradiation can deposit extremely vast anddense energy in solids. However, time integrated
luminescence spectra has not revealed so different
luminescence from those obtained by electron (or photo-)
irradiation. Otherwise, measurement of fast time-resolved
luminescence (<100ps) could observe quite newluminescence. Namely, almost all insulator crystals
irradiated by heavy ions present broad and ultra-fast(<100ps) pulsed luminescence continuum (UFLC) which
has not observed so far. Succeeding studies havecharacterized the new luminescence as follows. Since thefirst observation for alumina1), studies have been extended
to number of crystals: Almost all alkali halides except for
NaI, metal oxides as TiO2, SiO2, MgO, Al2O3, a
semiconductor like CdS, and a few kind of diamonds.
UFLC was observed universally in all the heavy-ion
irradiated insulator crystals except for diamonds. UFLC isvery broad but structured continuum from vacuum
ultraviolet region to a visible end. Its efficiency increases
largely with increasing atomic number of a projectile ion,
i.e. excitation density, moreover super linearly in manycases. This means that. the luminescence process is due tomulti orders. It is, nevertheless, significant that decay
curves are close to exponential. Also, luminescence
efficiency shows large material dependence. For examples,the luminescence efficiency for KI is about 100 times larger
than that for KCl, furthermore diamonds does not emit
UFLC. Also, it is worth noting that the continuum has
structures. The band peaks position near the luminescencepeaks of the known luminescence bands. The structure may
be explained because the continuum feels the similarpotentials to those in case of known luminescence derived
at self-trapped holes, defect-, and impurity- centers. Recent
studies shows that hole formation takes only few ps while
systems comprised of electrons like the self-trapped excitontake as long as 100 ps. On balance, the UFLC may beowing to electrons at higher levels of states quantized underpotential by holes. Such electrons are considered to be thosereleased densely by ionization and returned to thecylindrical hole of the track core1). Such electrons may exist
adjacently because of extremely high-density by heavy ion
irradiation. The UFLC is, we propose, a kind of induced
radiation which originates from the interactions among theelectrons near continuum levels. Then, UFLC would bebetter to be renamed as ion track luminescence continuum(ITLC).
In this report, we show that so-called spectral missing2)

known in alkali halides can be released in case of ITLC.
Recently, self-trapped excitons (STE) in alkali halides were
found to have three morphologies, type I, II and III2) bymeans of systematic experiments. An alkali halide however
does not have three STE luminescence bands although it
has three morphologies, but has usually two bands. One
band of the three types I, II, and III is used to be missing inluminescence. Figure 1 shows the missing for 9 alkali
halides by combinations of 3 alkalis x 3 halogens. The
slightly inclined lines show positions of the type I, II, andIII with change in alkali metals from Na to Rb, where solidlines show actual STE luminescence and dotted lines show
missing in luminescence. The triplet bands are shaded andthe singlet band not shaded. These data belongs to electronor photo-irradiation at 4.2 K. Results of ITLC for Xe-ion
irradiation are shown by broken lines. One may see that
ITLC exists at every missing position. This may beinterpreted because the potential due to dotted lines are too
shallow for electrons to stay in enough period to make STE
luminescence, but ITLC need not long stay because ofstrong radiative interaction by extremely dense
electron-hole pairs.

Fig. 1. STE luminescence spectra of nine alkali halides,with predominantly triplet bands shaded and predominantly
singlet bands not shaded. STEs are categorized into three
types I, II, and III. A dotted line means that anticipatedluminescence bands are missing. TLC, time resolved
luminescence at time 0 with Xe-ion irradiation, are shownby broken lines.

References
1) K. Kimura, J. Kaneko, S. Sharma, W. Hong, and N. Itoh: Phys.
Rev. B 60, 12626 (1999); K. Kimura: Nucl. Instr. Meth. Phys.
Res., B 212, 123 (2003).
2) K. S. Song and R. T. Williams: in Self-trapped excitons,(Springer, Berlin, 1993) p.168*1 Department of Applied Chemistry, Graduate School of Engineering
Tohoku University- 206 -

RIKEN Accel. Prog. Rep. 40 (2007)

Displaced-T site occupancy of hydrogen in Nb alloyed with a highconcentration of Mo†
E. Yagi,＊1 S. Koike,＊2 T. Sugawara,＊3 T. Shishido,＊3 T. Urai, and K. Ogiwara

An interaction of hydrogen with solute atoms
in metals is one of the fundamental problems on the
behaviour of hydrogen in metals. In order toelucidate the mechanism for the effect of soluteatoms on various properties of hydrogen, knowledgeof the state of hydrogen, especially its lattice
location is highly required. However, suchinformation has been extremely limited, because ofexperimental difficulties. To locate deuterium D,
both neutron diffraction method and channelling
method with a 3He beam are useful, and a number ofexperiments have been carried out, but for hydrogen
H there had been only a few neutron experiments
because of its experimental difficulties and nochannelling experiments despite their usefulness. As
the behaviour of H is not necessarily the same asthat of D as recognized, e.g., in a phase diagram
between metal-H and metal-D systems, experiments
on H are indispensable. Hence, to study the lattice
location of H the channelling method utilizing a
nuclear reaction 1H(11B, α)αα with a 11B beam ofabout 2 MeV has been developed.1,2) In this methodhydrogen can be detected by measuring emitted
α-particles. Yields of both 11B ions backscattered byhost metal atoms and α-particles are measured as afunction of the incident angle of a 11B beam bytilting the crystal around a channel in question. Fromsuch channelling angular profiles the lattice locationof hydrogen is determined.
We have been investigating the atomic state of
H in Nb-based Nb-Mo alloys on the basis of its
lattice location determined by the channelling
method described above. Nb is one of the group Va
metals in the periodic table and it is alloyed herewith an element smaller than itself, Mo. Regarding
the terminal solubility of hydrogen (TSH) in thegroup Va metals, it has been reported that undersized
metal solutes increase the TSH rapidly with soluteconcentration up to a certain solute concentration.
One of the objectives of the study for the Nb-Mo
alloys is to obtain information helpful to understandthe effect of undersized solutes on the TSH. In
addition, the Nb-Mo system forms a solid solution
over the entire Mo concentration (CMo) range,
keeping a bcc crystal structure with decreasing
lattice parameter from that of Nb to that of Mo. The

TSH in Nb at room temperature is about 3 % in thehydrogen-metal atom ratio (CH=[H]/[M]), whereas it
is very low in Mo. It is considered, therefore, that
this alloy system provides the stage suitable for H toshow various states in a bcc lattice. The systematic
study on the CMo dependence of the location of H is
expected to give information on the fundamental
properties of H in a bcc crystal.
The location of H has hitherto been studied up
to CMo=26 at.%. In Nb hydrogen is located at aterahedral (T ) site. At low CMo, hydrogen is trappedby a Mo atom at room temperature to be displaced
from a T site by about 0.6 Å towards its nearest
neighbour lattice point, i.e., a Mo atom (trapped site;Ttr).3) At high CMo, 20 at.%Mo, hydrogen is notobserved at such Ttr sites, but 70-80 % of H atoms
are located at T sites and 20-30 % of them are at
octahedral (O) sites for low CH.4) At 26 at.%Mo,
most of H atoms are located at T sites.5) The site
occupancy of hydrogen changes sensitively with
CMo. In the present study the location of H in a moreconcentrated 52 at.%Nb-48 at%Mo alloy has been
investigated at room temperature for CH=2.8 and
5.5 %. Figure 1 shows the channelling angularprofiles obtained for CH=5.5 %, indicating thathydrogen occupies a site different from T and Ttr.
From an analysis it is concluded that 75-85% of H
atoms are located at sites displaced from T sites by
about 0.3 Å towards their nearest neighbour O sites.
These sites are similar to the displaced-T sites whichwere observed in V under applied stress(stress-induced site change).2) The site change of H
observed on alloying with 48 at.%Mo is considered
to be due to lattice distortion introduced by alloying
with high concentration of Mo.
†

Condensed from the article in J. Phys. Soc. Jpn.
75, 034802 (2006)
1
RIKEN and The School of Sci. and Eng., Waseda
University
2
Department of Physics, Tokyo University of
Science3
Institute for Materials Research, Tohoku
University- 207 -

RIKEN Accel. Prog. Rep. 40 (2007)

References
1) E. Yagi, T. Kobayashi, S. Nakamura, Y. Fukai,
and K. Watanabe: J. Phys. Soc. Jpn. 52, 3441
(1983).
2) E. Yagi, T. Kobayashi, S. Nakamura, F. Kano,
K. Watanabe, Y. Fukai, and S. Koike: Phys.
Rev. B 33, 5121 (1986).
3) E. Yagi, S. Nakamura, F. Kano, T. Kobayashi,
K. Watanabe, Y. Fukai, and T. Matsumoto:Phys. Rev. B 39, 57 (1989).
4) E. Yagi and S. Koike: J. Phys. Soc. Jpn. 67, 340(1998).
5) E. Yagi, S. Koike, T. Matsumoto, T. Urai,and K. Ogiwara: Phys. Rev. B 66, 024206(2002).

Fig. 1. Channelling angular profiles obtained
for the 52 at.%Nb-48 at.%Mo alloy withhydrogen of CH=5.5- 208 -

RIKEN
Prog. Rep.
Rep. 3940 (2006)(2007)RIKENAccel.
Accel. Prog.

Production of microbeam of slow highly charged ionswith tapered glass capillary†
T. Ikeda, Y. Kanai, T. M. Kojima, Y. Iwai, T. Kambara, M. Hoshino∗1 ,T. Nebiki∗2 , T. Narusawa∗2 , and Y. Yamazaki∗3

†
∗1
∗2
∗3

Condensed from article in Appl. Phys. Lett. 89, 163502(2006)
Department of Physics, Sophia University
Kochi University of Technology
Also at the Institute of Physics, University of Tokyo

(a)

Glass
Capillary
inlet
outlet
φ 0.8 mm φ 24 µm

φ 4 mmAl plate

8+Ar

aperture
110 mm(b)

Deflector

Al foilA

PSD
30 - 50 mm

L=75 or 100 mm

(c)

24 µm

φ 2 mm

We have developed a method of collimating a slow
highly charged ion (HCI) beam with a single tapered
glass capillary. Even if the initial beam has a relatively
poor emittance, the glass capillary can realize a beam
size down to the micrometer range, maintaining theinitial charge state and kinetic energy. By considering the high reactivity of slow HCIs with the wall surface, one can conclude that the ions never touch theinner wall of the glass capillary during transmission.
A self-organized charge-up of the glass capillary innerwall is expected to play a vital role in these interesting
phenomena. 1–3) A similar glass capillary was used totransport a proton or He ion beam in the MeV range4) .
In this case, however, the beam touches the inner walland suﬀers from a small angle scattering with the wall
surface during the transport.
Slow HCIs have a high capability of modifying surfaces and cause eﬃcient sputtering without markedly
damaging the substrate. For example, a single HCI
induces a nanometer dot on graphite5–7) and Al2 O3
surfaces.5) It was also found that the F-Si bond direction of a Si(001)-F surface can be reconstructedfrom the three-dimensional momentum distribution of
F+ ions desorbed by slow HCIs; i.e., a stereochemical analysis can be performed with slow HCIs.8) Oncea microbeam is available, these functions speciﬁcallyfor slowing HCIs can be used to realize, e.g., the micropatterning of nanodots and element-sensitive microimaging. Note that a microbeam of slow HCIs was
not practically available because the HCI beam is relatively weak and its emittance is poor.
An ion beam of 8 keV Ar8+ was extracted froma 14.5 GHz Caprice electron cyclotron resonance ion
source at RIKEN, and then transported to an experimental chamber via an analyzing magnet. The
ion beam was then collimated by a 2 mmφ aperture(Fig. 1(a)), injected in a tapered glass capillary, andﬁnally detected by a position-sensitive detector (PSD)
via a deﬂector. The divergence of the incoming beam
after the aperture was at most ±3.3 mrad. The deﬂector was used for the charge-state analysis of thetransmitted ions. The outer and inner diameters of
the glass capillary at the inlet were 2 and 0.8 mm, and55 and 24 µm, respectively at the outlet. The typicallength of the glass capillary was 50 mm (Fig. 1(b)). To

Fig. 1. (a) Schematic view of the experimental setup, (b)image of the tapered glass capillary, and (c) microscopic
image of capillary outlet.

avoid macroscopic charge-up of the entrance surface ofthe glass capillary, it was covered by an Al foil with a
0.8 mm hole. The foil was used to monitor incoming
ion currents of 0.1 - 5 pA. The secondary electron yieldfor several keV Ar8+ ions from the Al foil is expected
to be ∼7; 9) the real current should be reduced 0.47fold. The ion current injected in the 0.8 mm hole of
the glass capillary was evaluated from the beam diameter on the Al foil and the hole diameter. The incident
currents hereafter correspond to the corrected current
mentioned above. The PSD consisted of a stack ofmultichannel plates and a wedge-and-strip-type anodeand its detection eﬃciency was ∼50 %.
The glass capillary was made of borosilicate, which
has a volume resistivity of 1015 Ωcm at 25◦ C and a softening temperature of 821◦ C. Tapered glass capillary
was prepared by heating a straight glass tube, andthen stretched by pulling both ends with a constantforce. The taper angle can be controlled by tuning
the temperature and force. Figure 1(c) shows a microscope image of such a capillary used for the present
experiment.
We observed the transmission of an ion beam asa function of time for the tapered glass capillary
injected with an 8 keV Ar8+ ion beam of 0.2 pA(∼1.5×105 Ar8+ ions/s) with a stability of ∼10 %. It- 209 1

RIKEN Accel. Prog. Rep. 40 (2007)

the PSD (L=75 mm) showed a single spot, which corresponds to the initial charge, i.e., the transmitted ionswere properly guided along the glass capillary withoutchanging the incident charge state. The angular divergence of the transmitted beam was evaluated from the
spot sizes and was found to be ∼ ±5 mrad.
Conventionally, magnetic and/or electrostatic lenses
have been employed to produce microbeams. By using such lenses, a submicron ion beam of a few tens ofkeV range was reported,10) wherein lenses with smallaberration and an ion source with good emittance were
employed. Our method presented here is not very sensitive to the initial beam with broad energy spread anddivergence, and was realized just by a tiny tapered
glass tube of ∼50 mm in length. In irradiation experiments, the beam position can be determined easily.

20

80
60

Y[mm]

Deflection angle of output beam [mrad]

100

40
20

-20
-20

X[mm]

20

0
-20
-40
-60
-80
-100
-100 -80 -60 -40 -20

0

20

40

60

80 100Tilting angle of glass capillary [mrad]Fig. 2. Tilting angle dependence of peak position for incident current of ∼0.01 pA: The horizontal axis is thetilting angle. The vertical axis corresponds to the reconstructed deﬂection angle of the beam from the peak
positions at the PSD. The horizontal and vertical error
bars show the accuracy of the tilting dial reading andthe spot size (FWHM), respectively.

was observed that the transmission current increased
slowly with a time constant of several tens of seconds,
and then became stable for more than 1200 s. The
peak count was about 1600 cps. The focusing factor,
deﬁned by the ratio of Nt /So to Ni /Si , is estimated tobe ∼10, where Nt is the number of transmitted ions,
Ni is the number of injected ions into the glass capillary, and So and Si are the geometrical outlet andinlet cross sections of the glass capillary, respectively.
This factor depends on the taper angle, outlet size, andinput current.
The upper left inset of Fig. 2 shows the position of
the transmitted beam on the PSD (L=100 mm) when
the glass capillary was tilted relative to the axis of theincident current of ∼0.01 pA. The relationship between
the tilting angle of the glass capillary and the deﬂected
angle of the beam is shown in Fig. 2, which proves thatthe beam was well guided to the direction of the glass
capillary tilted by as large as 100 mrad. Note that thedeﬂection angle is an order of magnitude larger thanthe half opening angle (∼8 mrad) of the tapered glass
capillary when the cross section of the glass capillary
along its axis is assumed to be trapezoid.
The charge-state distribution of the transmitted
HCIs for an incident current of 0.3 pA was measured
by biasing the deﬂector downstream of the glass capillary without tilting. The transmitted beam proﬁle at2- 210 -

References
1) N. Stolterfoht, J.-H. Bremer, V. Hoﬀmann, R. Hellhammer, D. Fink, A. Petrov, and B. Sulik: Phys. Rev. Lett.
88, 133201 (2002).
2) Y. Kanai, M. Hoshino, T. Kambara, Y. Yamazaki, R.
Hellhammer, and N. Stolterfoht: 24th International
Conference on Photonic Electronic and Atomic Collisions Abstract, Fr131 (2005).
3) Y. Kanai, M. Hoshino, T. Kambara, T. Ikeda, R. Hellhammer, N. Stolterfoht, and Y. Yamazaki: Nucl. Instrum. Methods Phys. Res., Sect. B 258, 155 (2007).
4) T. Nebiki, T. Yamamoto, T. Narusawa, M. B. H. Breese,
E. J. Teo, and F. Watt: J. Vac. Sci. Technol. A 21, No.5,
1671 (2003).
5) I. C. Gebeshuber, S. Cernusca, F. Aumayr, and H. Winter: Int. J. Mass Spectrometry 229, 27 (2003).
6) N. Nakamura, M. Terada, Y. Nakai, Y. Kanai, S.
Ohtani, K. Komaki, and Y. Yamazaki: Nucl. Instrum.
Methods Phys. Res., Sect. B 232, 261 (2005).
7) M. Terada, N. Nakamura, Y. Nakai, Y. Kanai, S.
Ohtani, K. Komaki, and Y. Yamazaki: Nucl. Instrum.
Methods Phys. Res., Sect. B 235, 452 (2005).
8) N. Okabayashi, K. Komaki, and Y. Yamazaki: Nucl.
Instrum. Methods Phys. Res., Sect. B 205, 725 (2003).
9) A. Arnau, F. Aumayr, P. M. Echenique, M. Grether,W. Heiland, J. Limburg, R. Morgenstern, P. Roncin, S.
Schippers, R. Schuch, N. Stolterfoht, P. Varga, T. J. M.
Zouros, and H. P. Winter: Surface Science Reports 27,
113 (1997).
10) Y. Ishii, A. Isoya, and T. Kojima: Nucl. Instrum.
Methods Phys. Res., Sect. B 210, 70 (2003).

RIKEN Accel. Prog. Rep. 40 (2007)

Auger electrons from excited N ions after passing through Ni
microcapillaries
Y. Kanai, Y. Nakai, Y. Iwai, K. Nishio,∗1 H. Masuda,∗1 and Y. Yamazaki9) R. Mann et al.: J. Phys. B 14, 1161 (1981).
10) M. H. Chen: Phys. Rev. A 31, 1449 (1985).

16+Intensity (arb. unit)

60 keV N with a Ni Microcapillary

0.6
0.4
0.2

Department of Applied Chemistry, Tokyo Metropolitan University

400

Fig. 1. Typical Auger electron spectrum for 60keV N6+
with an energy resolution of about 6eV. The higherenergy region (340-400eV) of the spectrum may be
attributed to the K-LL Auger electrons from hollow
atoms. K-LM Auger electron signals from excited statesof Li-like ions may also exist at about 380eV. The lowerenergy region (310-340eV) of the spectrum can be attributed to K-LL Auger electrons from excited states of
Li- and Be-Like ions.

2
6+

60 keV N with a Ni MicrocapillaryA

C a b Dc E

B

1

0

1) S. Ninomiya et al.: Phys. Rev. Lett. 78, 4557 (1997).
2) Y. Kanai et al.: Nucl. Instrum. Methods Phys. Res. B
233, 103 (2005).
3) Y. Iwai et al.: Nucl. Instrum. Methods Phys. Res. B
235, 468 (2005).
4) Y. Morishita et al.: Phys. Rev. A 70, 012902 (2004).
5) Y. Yamazaki: Int. J. Mass Spectro. 192, 437 (1999).
6) F. W. Meyer et al.: Phys. Rev. Lett. 67, 723 (1991).
7) J. Limburg et al.: Phys. Rev. Lett. 73, 786 (1994).
8) J. Ducrée et al.: Phys. Rev. A 58, R1649 (1998).

350

Electron Energy in Projectile Frame (eV)References

∗1

0.8

0
300

Intensity (arb. units)

When highly charged ions(HCIs) approach a metallic surface, multiple electrons from the surface transfer
to the excited states of ions and hollow atoms/ions areproduced. Previously, we measured X-rays1–3) and visible lights4) emitted from such excited ions in order tostudy hollow atom formation and its decay processes.
We used a metallic microcapillary foil as a target to
produce such excited ions, which permits us to study
the ﬁnal stage of the decay of excited ions5) . Recently,
we have started the measurements of Auger electrons
emitted from excited ions produced by the interaction
between HCIs and an inner wall of a microcapillary,which gives us information complementary to our previous X-ray measurements.
Experiments were performed at the Slow Highly
Charged Ion facility in RIKEN. N6+ (25-60keV) ionsfrom a 14.5GHz electron cyclotorn resonance ion
source were used. Auger electrons, which were emitted from excited ions, were measured using an electrostatic analyzer at an observation angle of 0◦ withrespect to the beam direction. A typical spectrum isshown in Fig. 1. Taking into account previous studies6–8) using a ﬂat metal target and theoretical calculations9,10) , the higher-energy region of the spectrum
may be attributed to the K-LL Auger electrons emitted from hollow atoms, which have one K vacancy andmany electrons in the L- and M-orbitals, and the lowerenergy region to the K-LL Auger electrons from Li- andBe-like excited states.
To identify Auger transitions, we measured an electron spectrum at approximately 310-340eV and higherenergy resolution (1.5eV). The spectrum is shown in
Fig. 2. Arrows indicate the K-LL Auger electron energies for Li- and Be-like N ions9,10) . We observed aclear, single peak at 316eV, which can be attributed to
the Auger electron from the (1s2s2p 4 P) states within
our experimental error (1.5eV). These states were predicted by previous X-ray measurements1) .

310

315

320

325

330

Electron Energy in Projectile Frame (eV)Fig. 2. High-energy-resolution spectrum for 60keV N6+ .
Reported energy positions for K-LL Auger electrons areindicated by arrows. Corresponding excited states are
A: (1s2s2 2 S), B: (1s2s2p 4 P), C: (1s2s2p 2 P), D: (1s2p2
4P), E: (1s2s2p 2 P)9) , a: (1s2s2 2p 3 P), b: (1s2s2p2 5 P),
and c: (1s2s2 2p 1 P)10) . A clear single peak at about
316eV can be attributed to the K-LL Auger electrons
from (1s2s2p 4 P) excited states. The energy resolution
was about 1.5eV.

- 211 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Hyperfine structure of Rb and Cs atoms in superfluid helium
T. Furukawa, Y. Matsuo, A. Hatakeyama,∗1 T. Ito,∗2 Y. Ota,∗2 K. Fujikake,∗2 T. Kobayashi, and T. Shimoda∗3
We have been studying the spin properties of impurity atoms in superfluid helium (He II) with the aim ofestablishing a versatile method for determining the nuclear moments of unstable nuclei1) . Recently, we havemeasured the hyperfine resonances of alkali Cs atoms
precisely using the sweep of microwave frequencies2) .
With the same system, we have also successfully measured the hyperfine resonances of alkali Rb atoms forthe first time. In this report, we describe the experimental results of a measurement of the hyperfine structures of alkali Rb and Cs atoms immersed in superfluid
helium (He II).
The experimental setup used is described in Ref. 2.
In measuring the Rb hyperfine resonances, we used
a RbCl crystal as a sample. The wavelengths of thepumping laser (cw Ti:Sapphire) and the monochromator are also tuned to the absorption (780nm) and emission (793nm) lines of Rb D1 transition in He II3) . The
other conditions are same as those described in Ref. 2.
Figure 1 shows LIF intensity as a function of microwave frequency. Considering the Zeeman effect4) ,the hyperfine coupling constant A is determined fromthe peak frequencies. The preliminary values of themeasured hyperfine coupling constants are listed in Table 1. The values are slightly different (0.5-0.6% larger)
from those in vacuum, owing to the effects of He II
pressure5) . The differences in values of the constantsof 85,87 Rb atoms are smaller than that of 133 Cs. Thisis probably due to the fact that Cs atoms are affected
more strongly by the interaction from surrounding He
atoms. The difference in the magnitude of interaction
is attributed to the differences in factors such as atomic
radius and the combined strength of valence electrons.

85Rb – σ+ pumping

87Rb – σ+ pumping

85Rb – σ- pumping

87Rb – σ- pumping∗2∗3

Dept. of Basic Sci., University of Tokyo
Inst. of Phys., Meiji University
Dept. of Phys., Meiji University

From the measured constants A of 85,87 Rb atoms in
He II, we determined the nuclear magnetic momentof 87 Rb with repspect to the nuclear moment of 85 Rb.
The hyperfine coupling constant A, nuclear spin I, andnuclear magnetic moment µ between the isotopes a X
and b X are related as
Aa Ia
Ab I b= b × (1 + a∆b ),
a
µI
µI

(1)

where a∆b is a magnetic hyperfine anomaly6) . From
Eq. (1), neglecting hyperfine anomaly, the nuclear moment of 85 Rb is deduced asµ85Rb= µ87Rb
×I
I

A85Rb I 85Rb,
A87Rb I 87Rb(2)

where the nuclear moment µ85Rb
I,HeII = 1.35784(1)µN
with the measured constants A in He II, andµ85Rb
I,vacuum = 1.357782(1)µN with the measured constants A in vacuum7) . The actual nuclear moment of
85
8)
Rb is µ85Rb
I,true = 1.3533515(8)µN . The deduced nuclear moment from the measured constants A in He
II is slightly (<1%) different from the actual nuclear
moment. This difference is attributed to the effectof hyperfine anomaly. From Eq. (1), the hyperfine
anomaly for 85 Rb and 87 Rb in He II is deduced as
85Rb 87Rb∆HeII = −0.003307 and that in vacuum is deduced as 85Rb ∆87Rb
vacuum = −0.003474.
The two hyperfine anomaly values are slightly(∼5%) different. The difference is probably due to thedeformed (compressed) wave function of a valence electron in a Rb atom. The detailed mechanism of such ashift is still under investigation. We will calculate theatomic status in He II theoretically in the future.
References

Fig. 1. Measured hyperfine transitions of 85 Rb (above) and87
Rb with σ + (left) and σ − (right) pumping.
∗1

He II (GHz) vacuum (GHz)ratio
Cs
2.31276(1)2.29815794
1.006353(4)85Rb
1.01702(2)1.01191092
1.00505(2)87
3.43517(3)3.41734131
1.005217(9)Rb
Table 1. Hyperfine coupling constants of Rb and Cs atoms
in He II (preliminary).
1331) T. Furukawa et al.: Phys. Rev. Lett. 96, 095301 (2006).
2) T. Ito et al.: RIKEN Accel. Prog. Rep. 40, to be published.
3) Y. Takahashi et al.: Phys. Rev. Lett. 71, 1035 (1993)
4) T. Furukawa et al.: RIKEN Accel. Prog. Rep. 39, 104(2006)
5) Y. Takahashi et al.: Z. Phys. 98, 391 (1995).
6) S. Büttgenbach: Hyperfine Int. 20, 1 (1984).
7) E. Arimondo et al.: Rev. of Mod. Phys. 49, 31 (1977).
8) N.J. Stone et al.: Atomic Data and Nuclear Data Tables
90, 76 (2005).

- 212 -

1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

Precise measurement of the hyperfine splitting of Cs atoms
in superfluid helium
T. Itou,∗1 T. Furukawa, Y. Matsuo, A. Hatakeyama,∗3 T. Kobayashi, Y. Ota,∗1 K. Fujikake,∗1
H. Odashima,∗1 and T. Shimoda∗2Laser spectroscopy in superfluid He (He II) is an effective method of determining the nuclear momentsof unstable nuclei from their hyperfine structure1) .
Atoms in He II show a shift and broadening of their
atomic excitation spectra that are large, whereas theshift and broadening are relatively small in the emission stage, because implanted atoms reside in bubblelike cavities (He bubble)2) . In contrast, the widths andfrequencies of hyperfine resonant lines of the atoms in
He II are very close to those in free space. Moreover,the electronic spin relaxation time of Cs atoms in He
II is particularly long because of the spinless property
of He atoms3) . These findings suggest that the hyperfine and Zeeman sublevel structures are not strongly
perturbed by surrounding He atoms. Therefore, theprecise measurement of atomic hyperfine splitting isfeasible in He II.
In this study, we measured the hyperfine transitionof Cs atoms in the ground state obtained by observing
laser-induced fluorescence (LIF)2) . The experimental
setup is shown in Fig. 1. The apparatus consistedof a cryostat chamber (Oxford) with quartz windows,
a detection system, a microwave sweeping system, andthree lasers. The bottom part of the cryostat contained
liquid He. An open-top quartz cell (70 × 70 × 70 mm3 )was placed above the liquid surface and was filled withHe II by transferring liquid He utilizing the fountaineffect of He II. A CsI sample held about 1 cm above
the quartz cell was ablated with an output of the third
harmonic generation of a Nd:YAG laser (wavelength,
355nm; pulse energy, 3mJ; repetition rate, 10Hz; pulse
width, 10ns) through one of the windows. Cs clusters produced by laser ablation and introduced into
He II were dissociated to disperse Cs atoms in theobservation region of He II by a femtosecond pulsed
Ti:Sapphire laser (wavelength, 790nm; pulse energy,
150µJ; repetition rate, 500Hz; pulse width, 200fs). The
densities of implanted Cs atoms were about 108 -1010
cm−3 in He II. The other cw Ti:Sapphire laser (wavelength, 876nm; power, 150mW) for the optical pumping of Cs atoms were irradiated continuously into theobservation region where a magnetic field of ∼ 5G wasapplied in the direction of the pumping laser. Thenthe implanted Cs atoms were optically pumped andpolarized immediately. The optically pumped atoms
∗1
∗2
∗3

Department of Physics, Graduate School of Science andTechnology, Meiji University
Department of Physics, Graduate School of Science, Osaka
University
Institute of Physics, Graduate School of Arts and Sciences,
The University of Tokyo

were subjected to microwave radiation with frequency
sweeping. The emitted photons were detected using aphotomultiplier tube (PMT) through a monochromator set at a Cs emission wavelength of 892 nm, and theobtained signals were sent to a multi-channel scaler.

Fig. 1. Experimental setup.

Figure 2 shows the hyperfine transition spectrumof Cs atoms in He II. The peak position and widthof the hyperfine resonant spectrum are 9.2580915(4)GHz and about 100 kHz, respectively. This narrow andclearly Lorentz-formed spectrum suggests the feasibility of a precise laser spectroscopic study of atoms in He
II. A detailed discussion about the hyperfine structure
in He II is described in Ref. 4

Fig. 2. Hyperfine transition spectrum of Cs atoms in He
II.

References
1) T. Furukawa et al.: RIKEN Accel. Prog. Rep. 38, 99(2005).
2) B. Tabbert, H. Günther, and G. zu Putlitz: J. Low
Temp. Phys. 109, 653 (1997).
3) T. Furukawa et al.: Phys. Rev. Lett. 96, 095301 (2006).
4) T. Furukawa et al.: RIKEN Accel. Prog. Rep. in press.

- 213 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Properties of laser ablation plasma generated by high power
Nd:YAG laser
T. Kanesue,∗1 S. Kondrashev,∗2 and M. Okamura
We have developed the Direct Plasma Injection
Scheme (DPIS) that consists of the Laser Ion Source(LIS) and RFQ linac for extracting and accelerating
highly charged intense ion beams from the laser ablation plasma. We succeeded in accelerating a 60 mA
Carbon beam using DPIS1) .
The performance of LIS strongly depends on thelaser performance and it is nessesary to investigate theproperties of the laser produced from plasma before
performing acceleration experiments.
We used a 2.3 J / 6 ns Nd:YAG laser (1064 nm wavelength), Thales SAGA230. The estimated laser power
density focused onto the solid state target with the convex lens (100 mm focal length) is 3.2 × 1012 W/cm2 .
We investigated the laser ablation plasmas of C, Al,
Fe, Ag and Ta, respectively. Charge state distribution, current density and the number of ions in theplasma were measured at a distance of 3.7 m from thetarget. The current density at an arbitrary position
can be calculated with the relationship showing thatthe plasma current is proportional to L−3 (L : drift
distance)2) . The details of the experimental procedure
are shown in ref.3) .
Table 1 shows the number of ions per shot under the

RFQ injection condition (30 cm away from the targetand φ 6 mm) and the current densities at 30 cm and 60
cm away from the target for the highest charge state.
The data for the highest yield charge state are shownin Table 2. Here, current density represents the peakvalue of one pulse.
According to these tables, ions lighter than Fe shouldbe acclerated with some mA-order using our schemewith the RFQ designed to accelerate charge to mass
ratio (Q / M) = 1 / 3 ions, even considering the losses
through injection. In contrast, Ag and Ta might not
be accelerated with high intensity because we did notobserve Q / M > 1 / 3 ions.
From these data, we succeeded in achieving 60 mA
Al beam formation at the exit RFQ4) . We are preparing for Ag +15 acceleration using the new RFQ dedicated for Q / M = 1 / 8 (0.125).
----References

1) M. Okamura, et al.: Rev. Sci. Instrum. 77, 03B303(2006)
2) B. Yu. Sharkov, S. A. Kondrashev: Proc. EPAC96, Sitges, Spain, 1996, p. 1550
3) T. Kanesue, et al.: Proc. EPAC 2006, Edinburgh, Scotland, p. 1720
4) in this progress report
Table 1. Summary of plasma properties for highest charge
state at 30 cm away from target.

Element
12

C
Al
56
Fe
107
Ag
181
Ta
27

Highestcharge state
6
11
20
20
9

Q/M
0.50
0.41
0.36
0.19
0.05

Number ofparticles
1.27 × 1011
2.50 × 1010
1.23 × 109
1.49 × 108
1.62 × 109

Current density[mA/cm2 ] at 30 cm
1458
183
29
6.1
1.4

Current density[mA/cm2 ] at 60 cm
182
23
3.7
0.8
0.2

Table 2. Summary of plasma properties for highest yield
charge state.
Element
12

C
Al
56
Fe
107
Ag
181
Ta
27

∗1
∗2

Highest yield
charge state
6
10
16
15
4

Q/M
0.50
0.37
0.29
0.14
0.02

Number ofparticles
1.27 × 1011
4.72 × 1010
1.70 × 1010
2.19 × 109
1.06 × 1010

Current density[mA/cm2 ] at 30 cm
1458
746
520
119
28

Current density[mA/cm2 ] at 60 cm
182
93
65
15
3.5

Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University
Institute of Theoretical and Experimental Physics, Moscow,
Russia- 214 -

1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)

Time-delay matrix analysis of several overlapping resonances
K. Aiba,∗1 A. Igarashi,∗1 and I. Shimamura[Overlapping resonances, time delay, atomic scattering, photoionization, nuclear reactions]
Resonance structures often occur in the cross sections σ(E) for multichannel scattering and photoionization. Such structures may be analyzed to extract
resonance parameters, i.e., the position Er , width Γ,and the shape parameter. However, the eigenphasesum δ(E) for the continuum wave function, which
increases abruptly in a narrow resonance energy region, is more useful for resonance analysis than σ(E);δ(E) satisﬁes the same Breit-Wigner formula as for the
single-channel scattering phase shift.1) An even better
technique is to detect sudden changes in dδ(E)/dE.
The time-delay matrix Q(E) (= ih̄S[dS †/dE]) introduces another perspective,2,3) S being the S matrix
and S † its Hermitian conjugate. For S(E) or δ(E) of
any E-dependence, the trace Tr Q is related to δ by∑∑2h̄dδ/dE = Tr Q(E) ≡ i Qii (E) = i qi (E),4

δ/πwhere {qi (E)} are the eigenvalues of the Q matrix.3)
When N resonances overlap each other, the analysisof S(E) or σ(E) is very complex, while δ(E) increases
rapidly by ∼N π. Also, Tr Q(E) is expressible as asuperposition of N Lorentzian proﬁles Lν (E)∑
Tr Q(E) =Lν (E) + 2h̄dδb (E)/dE,(1)tained by the hyperspherical coupled-channel method;
see Fig. 1 for E below the energy of He+ (n=5). Actually, most {qi (E)} are too small to distinguish fromthe base line, but many overlapping resonances are
seen. The highest energy region of Fig. 1 is enlarged inFig. 2. Rapid increase in δ(E) occurs twice in Fig. 2(a),suggesting two resonances. Another one emerges in
Tr Q(E) in Fig. 2(b), showing that dδ/dE is a better
probe of resonances than δ(E). An even more sensitive probe turns out to be {qi (E)} in Fig. 2(b). Obvious avoided crossings are observed, which, if diabatically connected, reveal as many as ﬁve Lorentzians. At
least two of them would have been missed by the conventional means of analysing δ(E) or dδ(E)/dE. The
detailed structure in {qi (E)} having been uncovered,Eq. (1) with ﬁve Lorentzians is now ﬁtted to the calculated Tr Q(E) of Fig. 2(b). Figure 2(c) includes all
the obtained Lorentzians, which are eﬀectively the diabatization of {qi (E)} and may be called diabatic resonances. This procedure aﬀords a transparent visual
understanding of the overlapping resonances.

νδb being the background part of δ. We proved analytically for double resonances that two eigenvalues{qi (E)} take such Lorentzian shapes avoided from eachother only near their crossing point.4) The {qi (E)}look almost like crossing Lorentzians if the avoidanceis weak, but need careful examination for recognizing
the avoided crossing if the avoidance is strong.
We examine the eigenvalues {qi (E)} for He(1Po ) ob4

2

Tr Q

7

6

3

−0.12

qi (104au)

85−0.1124

qi (10 au)

2.0

10

1.0

11

13

15

16

17

−0.100−0.0983.0
0.0−0.092−0.09622

23 24−0.094

25

27

28

26

21

−0.092
31
29 30

32

29

30

−0.08820−0.091−0.090−0.089References−0.088

Total Energy (au)Fig. 1. The eigenvalues {qi (E)} of the time-delay matrix
Q(E) for He(1Po ) and their sum, Tr Q(E).
∗1

2

32
31

Fig. 2. (a) Eigenphase sum δ(E). (b) Eigenvalues {qi (E)}and their sum, Tr Q. (c) Lorentzians Lν (E) representing diabatic resonances, the background, and their sum.

0.0
6.0

background
total

28

Total Energy (au)

19
18

12

9

(c)

4

0
−0.089−0.104
14

Tr Q

2

6

1

0.0

(b)

4

0

6

0.4

2
0

Lν (104au)

0.8

(a)

Department of Applied Physics, University of Miyazaki

1) A. U. Hazi: Phys. Rev. A 19, 920 (1979).
2) F. T. Smith: Phys. Rev. 118, 349 (1960).
3) A. Igarashi and I. Shimamura: Phys. Rev. A 70,
012706 (2004); J. Phys. B 37, 4221 (2004).
4) I. Shimamura, J. F. McCann, and A. Igarashi: J. Phys.
B 39, 1847 (2006).

- 215 -

1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)µSR study of the impurity eﬀects on the Cu-spin ﬂuctuationsin the overdoped La2−x Srx Cu1−y Zny O4
T. Adachi,∗1 Risdiana,∗1 N. Oki,∗1 S. Yairi,∗1 Y. Tanabe,∗1 K. Omori,∗1 T. Suzuki∗2 I. Watanabe∗2 A. Koda∗3
W. Higemoto∗4 and Y. Koike,∗1

∗1
∗2
∗3

∗4

Department of Applied Physics, Tohoku University
The Institute of Physical and Chemical Research (RIKEN)
Muon Science Laboratory, Institute of Materials Structure
Science, High Energy Accelerator Research Organization(KEK-IMSS)
Advanced Science Research Center, Japan Atomic Energy
Agency (JAEA)

underdoped regime. These results are consistent withthose of the inelastic neutron-scattering experiment on
La2−x Srx CuO4 with x = 0.25 − 0.30,4) in which the
maximum dynamic spin susceptibility of the incommensurate magnetic peaks, χ”(ω), decreases linearlywith increasing x and disappears at x = 0.30. The
present results also indicate that there is no quantum
critical point at x ∼ 0.19, as proposed by Panagopoulos et al.5) In addition, the phase-separation modelin the overdoped regime6) is also consistent with thepresent results, because the maximum depolarization
rate of muon spins decreases with increasing x in agreement with the decrease in superconducting volume
fraction. That is, superconducting and normal-stateregions may be phase-separated in an overdoped sample of La2−x Srx CuO4 .

Normalized Asymmetry

In the La-214 high-Tc system, the dynamical stripe
correlations of spins and holes tend to be pinned
and statically stabilized not only by the characteristic structure of the tetragonal low-temperature
structure1) but also by nonmagnetic Zn impurities.
2)
So far, impurity eﬀects on Cu-spin dynamics
and superconductivity in the underdoped regime ofLa2−x Srx Cu1−y Zny O4 with x ≤ 0.15 have been investigated by zero-ﬁeld (ZF) muon-spin-relaxation (µSR)
measurements.2,3) It has been found that the Cu-spin
ﬂuctuations around Zn exhibit a slowing down due tothe pinning of the dynamical stripe correlations by Zn,
leading to the formation of a static stripe order and thedestruction of superconductivity around Zn. It is clearthat the static stripe order competes with superconductivity, but the dynamical stripe correlations may
play an important role in the appearance of superconductivity. If this is the case, similar impurity eﬀects
must be observed not only in the underdoped regime
but also in a wide hole concentration range.
Therefore, we have investigated Zn-impurity eﬀects
on Cu-spin ﬂuctuations by µSR measurements in theoverdoped regime of La2−x Srx Cu1−y Zny O4 with x =0.18 − 0.30 and y = 0 − 0.10 to elucidate whether or
not the stripe-pinning model holds well even in theoverdoped regime of La2−x Srx CuO4 . Polycrystalline
samples prepared by the ordinary solid-state reaction
method were used in ZF-µSR measurements at the
RIKEN-RAL Muon Facility in the UK and at the
KEK-MSL in Japan.
The ZF-µSR time spectra of La2−x Srx Cu1−y Zny O4
with x = 0.18 − 0.30 and y = 0.03 at 0.3 K areshown in Fig. 1. In samples with x = 0.18 − 0.27,
an exponential-like depolarization of muon spins isobserved, indicating the Zn-induced slowing down of
Cu-spin ﬂuctuations. The rate of such depolarization
systematically decreases with increasing x and almost
no fast depolarization of muon spins is observed for
x = 0.30, at which superconductivity disappears. The
present results suggest that dynamical stripe correlations exist in a wide range of x’s where superconductivity appears and that the stripe-pinning modelholds well in the overdoped regime as well as in theLa2-xSrxCu0.97Zn0.03O4

1

x = 0.30

T = 0.3 K

0.27
0.25
0.22
0.21

0.5

0.18

0

0

2

0.20

4
Time (µsec)

6Fig. 1. Zero-ﬁeld µSR time spectra of La2−x Srx Cu0.97 Zn0.03 O4
with x = 0.18 − 0.30 at 0.3 K

References
1) J. M. Tranquada et al.: Nature 375, 561 (1995).
2) T. Adachi et al.: Phys. Rev. B 69, 184507 (2004).
3) Y. Koike et al.: Physica C 426-431, 189 (2005).
4) S. Wakimoto et al.: Phys. Rev. Lett. 92, 217004 (2004).
5) C. Panagopoulos et al.: Phys. Rev. B 69, 144510 (2004).
6) Y. Tanabe et al.: J. Phys. Soc. Jpn. 74, 2893 (2005).

- 217 -

1

RIKEN
Accel.
RIKEN
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)µSR study of the impurity eﬀects on the Cu-spin ﬂuctuations inelectron-doped high-Tc superconductor
Pr0.86 LaCe0.14 Cu1−y Zny O4+α−δ
Risdiana,∗1 T. Adachi,∗1 T. Suzuki,∗2 I. Watanabe,∗2 and Y. Koike∗1∗1∗2

Department of Applied Physics, Tohoku University
The Institute of Physical and Chemical Research (RIKEN)

samples with y up to 0.05. However, the temperaturedependences of the spectra are similar regardless ofthe y value. That is, no Zn-induced slowing of the Cuspin ﬂuctuations is observed, which is very diﬀerent
from the case for hole-doped La2−x Srx Cu1−y Zny O4 2) .
Possible reasons are as follows: (i) There may be no
dynamical stripe correlations of spins and electrons in
the electron-doped system. (ii) The eﬀect of Pr3+ moments on the µSR spectra may be stronger than thatof a small amount of Zn impurity.
To obtain conclusive results, another electron-doped
cuprates without rare-earth moments should be used
for the µSR measurements.
References
1) J. M. Trangquada et al.: Nature 375, 561 (1995).
2) T. Adachi et al.: Phys. Rev. B 69, 184507 (2004).
3) R. Kadono et al.: J. Phys. Soc. Jpn. 72, 2955 (2003).

Pr0.86LaCe0.14Cu1-yZnyO4+αα−δ
0.860.040.14<δδ<0.09<1-y0.09y 4+
0.04<
y=0

1.0

100 K
50 K
20 K
1K
0.3 K

0.5

Normalized Asymmetry

Although the mechanism of the superconductivity in high-Tc superconducting cuprates has not yet
been clariﬁed, a mechanism based upon the dynamical stripe correlations of spins and charges is a probable one1) . So far, the eﬀects of impurities on the
Cu-spin dynamics and superconductivity have been
investigated by zero-ﬁeld (ZF) muon-spin-relaxation(µSR) measurements in the underdoped regime ofLa2−x Srx Cu1−y Zny O4 with x < 0.152) . It has beenfound that the ﬂuctuations of Cu spins around Zn
exhibit slowing due to the pinning of the dynamical
stripes by Zn, leading to the formation of a static stripe
order and the destruction of superconductivity around
Zn. This is an interpretation called the stripe-pinningmodel. It is of great interest whether or not the stripepinning model holds even for the electron-doped highTc cuprates and whether or not the mechanism in theelectron-doped high-Tc cuprates is diﬀerent from thatin the hole-doped ones. The study in the electrondoped high-Tc cuprates and the following comparison
with the results of the hole-doped ones will lead to a
general understanding of the mechanism of superconductivity. Therefore, we have investigated the eﬀects
of Zn substitution on the Cu-spin dynamics in electrondoped Pr0.86 LaCe0.14 Cu1−y Zny O4+α−δ (PLCCZO) by
ZF-µSR measurements at low temperatures down to
0.3 K, and increasing y to up to 0.05 and the oxygenreduced value δ to up to 0.09.
Figure 1 shows the ZF-µSR time spectra of thesuitably oxygen-reduced PLCCZO for various y values. For y = 0, Gaussian behavior is observed athigh temperatures above ∼ 100 K due to randomly
oriented nuclear spins, and an exponential depolarization of muon spins is observed at low temperatures
below ∼ 50 K. The temperature-dependent change inthe spectra above 20 K is regarded as being due to thestatic random magnetism of small Pr3+ moments3) . It
is found that the asymmetry A(t), namely, the µSRtime spectrum in the long-time region above 5 µsec
increases with decreasing temperature at low temperatures, suggesting the possible slowing of the Cu-spin
ﬂuctuations. It is interesting that the slowing of the
Cu-spin ﬂuctuations is observed even in the impurityfree sample. This may be due to the possible enhancement of the Cu-spin correlation assisted by the Pr3+
moments. The increase in A(t) in the long-time region
at low temperatures is still observed for Zn-substituted0y(Zn)=0.01

1.0

0.5

0

y(Zn)=0.05

1.0

0.5

0
0

2

4

6

8

Time ( µ sec)
Fig. 1. ZF-µSR time spectra of the suitably oxygenreduced Pr0.86 LaCe0.14 Cu1−y Zny O4+α−δ with y = 0,0.01, and 0.05 and 0.04 ≤ δ ≤ 0.09 at temperatures
down to 0.3 K.

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RIKEN40 (2007)RIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 39(2006)µSR study of impurity eﬀects on Cu-spin dynamics andsuperconductivity in La2−x Srx Cu1−y (Zn,Ni)y O4 with x = 0.15
T. Adachi,∗1 N. Oki,∗1 Risdiana,∗1 S. Yairi,∗1 Y. Koike,∗1 and I. Watanabe∗2

Normalized Asymmetry

window decrease strongly in the presence of a small
In recent years, the eﬀects of nonmagnetic andamount of Zn and the decrease observed is stronger
magnetic impurities on the dynamical stripe correthan that observed for Ni. Moreover, both fractions
lations of spins and holes1) have attracted attencorrespond to each other. These results can be intertion. It has been proposed that the dynamical stripe
preted as follows: both Zn and Ni tend to pin the dycorrelations are pinned and stabilized by nonmagnamical stripe correlations so that superconductivity is
netic Zn, leading to the strong suppression of superdestroyed around Zn and Ni. The area of non-SC andconductivity around the hole concentration per Cu,
slowly ﬂuctuating or static region of Cu spins aroundp ∼ 1/8.2) To clarify the relationship between CuZn is larger than that around Ni, suggesting that the
spin dynamics and superconductivity, we have performed the zero-ﬁeld muon-spin-relaxation (ZF-µSR)
pinning by Zn is stronger than that by Ni.
and magnetic-susceptibility, χ, measurements in ZnReferencesor Ni-substituted La2−x Srx Cu1−y (Zn,Ni)y O4 with x =1) J. M. Tranquada et al.: Nature 375, 561 (1995).
0.13, ﬁnely changing y up to 0.10, and have found a
3–5)2) T. Adachi et al.: J. Low Temp. Phys. 117, 1151 (1999).
close relation between them.
Therefore, we have3) I. Watanabe et al.: Phys. Rev. B 65, 180516(R) (2002).
carried out ZF-µSR and χ measurements in optimally4) T. Adachi et al.: Phys. Rev. B 69, 184507 (2004).
doped La2−x Srx Cu1−y (Zn,Ni)y O4 with x = 0.15 and5) T. Adachi et al.: Phys. Rev. B 70, 060504(R) (2004).
y = 0 − 0.10, using sintered polycrystals, to clarify
6) Y. Koike et al.: Physica C 426-431, 189 (2005).
the relationship between Cu-spin dynamics and super7) T. Adachi et al.: Physica C (2007), in press.
conductivity.6,7) The ZF-µSR measurements were performed at the RIKEN-RAL Muon Facility in the UK
at temperatures down to 0.3 K.
The ZF-µSR time spectra of La2−x Srx Cu1−y (Zn,Ni)y O4
La2-xSrxCu1-y(Zn,Ni)yO4
with x = 0.15 and typical y values are shown in Fig. 1.
1.5
At high temperatures above 15 K, all the spectra showy(Zn) = 0y(Ni) = 0
1.0
Gaussian-like depolarization due to randomly oriented
3K
20 K
nuclear spins. For y = 0, the spectra are Gaussian-like
0.5
15 K
2K
down to 0.3 K, indicating that Cu spins ﬂuctuate fast
5K
0.3 K
−11
−6
0.0
beyond the µSR time window (10− 10 s). At lowy(Zn) = 0.005
y(Ni) = 0.005
temperatures, a fast depolarization of muon spins is1.0
observed for y(Zn)= 0.01, indicating the development
0.5
of a magnetic correlation between Cu spins. Moreover,
0.0
a fast depolarization and an almost ﬂat spectrum withy(Zn) = 0.01
y(Ni) = 0.01
a normalized asymmetry of ∼ 1/3 are observed for
1.0
y(Zn)= 0.02 − 0.03, indicating the formation of an in0.5
coherent magnetic order.
In the case of Ni substitution, on the other hand,
0.0y(Zn) = 0.02
y(Ni) = 0.02
the spectra are Gaussian-like for y(Ni)= 0.01 and a
1.0
fast depolarization is observed for y(Ni)≥ 0.02. These
results indicate that the formation of a magnetic order
0.5
requires a larger amount of Ni than that of Zn, which
0.0
is consistent with our previous result for x = 0.13.5)
y(Zn) = 0.03
y(Ni) = 0.03
1.0
We have estimated the volume fractions of Cu-spinstates with diﬀerent ﬂuctuation frequencies by ﬁtting
0.5
the time spectrum4,5) and the superconducting (SC)0.0state from the χ measurements on ﬁeld cooling (Meiss2 0 y(Ni) = 10.05
20 y(Zn) =10.05
ner volume fraction). It has been found that the vol1.0
Time (µµsec)
ume fractions of both the SC region and the region
0.5
in which Cu spins ﬂuctuate fast beyond the µSR time
∗1
∗2

Department of Applied Physics, Tohoku University
The Institute of Physical and Chemical Research (RIKEN)

Fig. 1. Zero-ﬁeld
0.0 µSR time spectra of La2−x Srx Cu1−y (Zn,Ni)y O4
y(Zn)y==0.10= 0.10temperatureswith x = 0.15 and0 − 0.03 aty(Ni)various1.0
down to 0.3 K.
0.5- 219 -

0.0
0

1

20

1

2

1

RIKENRIKENAccel.
Accel. Prog.
Prog. Rep.
Rep. 4039 (2007)(2006)

Cu-Spin Dynamics Studied by µSR in La2−x Srx CuO4 at about 100 K
I. Watanabe, T. Adachi∗1 and Y. Koike∗1[µSR, High-Tc , Cu-Spin Dynamics]

∗1

1.000

x=0.115x=0.024
139K
60K
21K

0.095

138K
55K
20K

0.090
0.085
1.000

x=0.04x=0.15

144K
60K
24K

0.095

Norm. Asy.

Normalized AsymmetryLa2-xSrxCuO4

0.090
0.085

0

1

2

140K
53K
16K
1.0
0.5
0

100K
0 5 10Time ( sec)

30

1

2

3

Time ( sec) )Fig. 1. Zero-ﬁeld µSR time spectra of La2−x Srx CuO4 with
x=0.024, 0.04, 0.115 and 0.15 at various temperatures.

La2-xSrxCuO4

200

Temperature (K)One of the fascinating models for describing themechanism of high-Tc superconductivity is the stripe
model1) . This model assumes the microscopic segregation of spins and holes in the CuO2 plane forming
stripes, which has theoretically been discussed to bepossibly important for the occurrence of high-Tc superconductivity2) . To clarify the correlation between the
dynamical properties of spins and holes, precise zeroﬁeld muon-spin-relaxation (ZF-µSR) measurements of
La2−x Srx CuO4 (LSCO) have been carried out at the
RIKEN-RAL Muon Facility over a wide range of holeconcentrations from x=0.024 to 0.15, probing a change
in the Cu-spin dynamics at a high temperature ofabout 100 K at which hole domains are expected to
be formed.
Figure 1 shows ZF-µSR time spectra of LSCO with
x=0.024, 0.04, 0.115 and 0.15 at various temperatures.
The inset shows the entire time spectrum of x=0.115
at 100 K. All time spectra show more or less a similar
Gaussian-type depolarization behavior. Therefore, theanalysis function A0 e−λt Gz (∆, t) was used. A0 and λare the initial asymmetry at t=0 and the dynamic depolarization rate, respectively. Gz (∆, t) is the static
Kubo-Toyabe function with a half-width of ∆ describing the distribution of the nuclear-dipole ﬁeld at themuon site.
An overall analysis has shown that changes of thetime spectrum can be parametized in terms of changesof λ. For instance, λ of LSCO with x=0.115 starts
to increase monotonically with decreasing temperature
at about 100 K, showing a change in the dynamics of
the internal ﬁeld at the muon site For convenience, thetemperature at which λ starts to increase with decreasing temperature is named Tµ and plotted in Fig. 2 asopen circles. The superconducting transition temperature determined from the resistivity measurements is
also shown and indicated by open triangles.
The temperature Tρmin at which resistivity is theminimum is taken from the literature3–5) and plottedin Fig. 2 as closed triangles and squares. It is foundthat the x dependence of Tµ is in good agreement withthat of Tρmin . This means that the origin of Tµ is related to the localization of holes in the normal state.
Therefore, the present study proves the coupling between the localization of holes and the change in the
dynamics of Cu-spin ﬂuctuations, which is an important feature of the stripe model.

TT min (0T)
Ando et al.

T min (0T and 18T)
Takeya et al.

150

T min (60T)
Boebinger et al.

100
AF

50

SG

0

0

0.05

SC Static Order

0.10

0.15

0.20

Sr Concentration, x
Fig. 2. Phase diagram of La2−x Srx CuO4 . Lines are guides
for the eyes.

References
1) J. M. Tranquada et al., Nature (London) 375, 561(1995).
2) V. J. Emery and S. A. Kivelson, Physica C 235-240,
189 (1994).
3) G. S. Boebinger et al., Phys. Rev. Lett. 77, 5417 (1996).
4) J. Takeya et al., Phys. Rev. Lett. 88, 077001 (2002).
5) Y. Ando et al., Phys. Rev. Lett. 88, 137005 (2002).

Department of Applied Physics, Graduate School of Engineering, Tohoku University- 220 -

1

RIKEN
Prog. Rep.
Rep. 3940 (2006)(2007)RIKEN Accel.
Accel. Prog.

Magnetism of lightly doped Ca2−x Nax CuO2 Br2 probed by µSR†
S. Kuroiwa,∗1 Y. Zenitani,∗1 Y. Tomita,∗1 J. Akimitsu,∗1 R. Kadono∗2,∗3 , I. Watanabe, S. Ohira∗
Ca Na CuO Br
0.18
A class of hole-doped cuprates, Ca2−x Nax CuO2 X2 (X=Cl,
x = 0.04
0.16
T=2KBr), which has the La2 CuO4 -type crystal structure
0.25
0.14
with apical halogen atoms, has been attracting much
100 K
0.12 ZF-µSR
interest as a stage for elucidating the role of apical
0.20
0
0.4
0.8
1.2
1.6
10 K
1,2)
8K
Time [ µs ]atoms over the CuO2 planes.
A peculiar doping
6K
0.15 2 K
dependence of superconductivity has been observed
5K
in oxybromide cuprate (X=Br, Na-CCOB), where Tc
0.10(a)
ZF-µSR= 19 K develops over an optimally hole-doped rex = 0.05
gion of x ∼ 0.25, which is substantially shifted fromthat of typical cuprates.2) Therefore, to investigate the
0.20
100 mTmagnetic properties in the low-doping region, we con10 mT
0.16
ducted µSR experiments on Na-CCOB with interme0 mT
diate sodium concentrations (0.03 < x < 0.15).
0.12 (b) LF-µSRµSR measurements were performed at the RIKENx = 0.05
RAL Muon Facility, UK. ZF- and LF-µSR spectra were
0
2
4
6
8
10
Time [ µs ]obtained between 2 K and ambient temperature.
Figure 1 shows ZF-µSR time spectra at several temFig. 1. (a) ZF- and (b) LF-µSR time spectra in Na-CCOB
peratures (inset: x = 0.04 at 2 K) in Na-CCOB with xwith x = 0.05 (Inset : x = 0.04).
= 0.05. The ZF-µSR time spectra exhibit no clear precession signal over a region of 0.03 < x < 0.15, which
is situated between antiferromagnetic (AF) and superconducting phases. This suggests a strongly disordered
0.4
x = 0.04
magnetic ground state dominating over the AF long0.2
range order. These∑2spectra were analyzed using the0equation Pz (t) =i=1 Ai GKT (∆dip , t) · exp(−λi t) +0.4
x = 0.05
AB , where Ai is the decay asymmetry for signals from0.2
the sample, AB is that from the sample holder, λi is the0
relaxation rates and ∆dip is the nuclear dipolar width.
x = 0.08
The second component (i = 2) is needed to ﬁt the data
0.4
only below 10 K to the strongly damped oscillation
0.2
seen in the spectra at 2 K. This suggests that a dis0
ordered magnetic ground state similar to a spin-glass
0.4
x = 0.15(SG) (or spin density wave) state is present, which is
0.2
either static or dynamically ﬂuctuating. Therefore, we
0have performed LF-µSR measurements in order to dis0
5
10
15
20
25
30
tinguish these two possibilities (see Fig. 1 (b)).
Temperature [ K ]As shown in Fig. 2, the longitudinal relaxation rateincreases at low temperatures for all Na-doped samFig. 2. Temperature dependence of longitudinal relaxation
ples. This is attributed to the slowing down of therate under LF = 100 mT for several values of x.
thermal ﬂuctuation of Cu moments. Since the enhancement of the longitudinal relaxation rate occurs
over a temperature region that is wider than that asdiagram is qualitatively similar to that of an ordinarysociated with the AF transition, such behavior in thesecuprates. However, these characteristic doping levels
samples (0.03 < x < 0.15) is attributed to the SG-likeare higher than those found in typical 2-1-4 cuprates,
magnetic state.
suggesting a positive shift of the entire phase diagram
Consequently, these results indicate that the phasefor carrier concentration x. This may be due to the†trapping of hole carriers on the energy band of apical
Condensed from the article in Physica B 374, 75 (2006)∗1 Department of Physics and Mathematics, Aoyama-Gakuin
Br rather than the O-2p orbital, because the energy
University, Japanbandof Br is located slightly closer to the Fermi level.
∗222AsymmetryxLongitudinal relaxation rate [ µs-1 ]Asymmetry

Asymmetry

2-x

∗3
∗

Muon Science Laboratory, IMSS-KEK, Japan
Department of Materials Structure Science, The Graduate
University for Advanced Studies (SOKENDAI)
Present address: Department of Physics, Ochanomizu University, Japan

References
1) Z. Hiroi et al.: Nature 371, 139 (1994).
2) Y. Zenitani et al.: Physica C 419, 32 (2005).

- 221 -

1

RIKEN Accel. Prog. Rep. 40 (2007)µSR study of localized spin triplets in Tl1−x Kx CuCl3 †T. Suzuki, I. Watanabe, A. Oosawa,∗1 T. Goto,∗1 F. Yamada,∗2 and H. Tanaka∗2[Bose-Einstein condensation, Bose glass phase, µSR]

†
∗1
∗2

Condensed from the article in J. Phys. Soc. Jpn. 75, 025001(2006) .
Department of Physics, Sophia University
Department of Physics, Tokyo Institute of Technology

Figure 2 shows the temperature dependence of theobtained relaxation rate λ of muon spins in zero field.
The solid line is a guide for the eye. With decreasing
temperature down to about 3 K, λ shows a rapid increase. This proves that the slowing down of spin fluctuations with high frequency in a paramagnetic state
occurs, and that the frequency of the spin fluctuations
comes into the µSR time window below about 3 K.
This slowing down of the spin fluctuations is possiblya precursor of the Bose glass phase at T = 0.
Tl1-xKxCuCl3 (x = 0.20)
ZF - µSR
10 K
3.0 K
1.0 K
0.3 K

19

18

17

Raw Asymmetry (%)

Raw Asymmetry (%)

20

16
0

22
0.3 K

20
18
16
14
12
0

5
10 15
Time (µsec.)

2

4
6Time (µsec.)

8

10

Fig. 1. Time spectrum of the zero-field muon-spinrelaxation (ZF-µSR) of Tl1−x Kx CuCl3 with x = 0.2
at each temperature. Solid lines are fitted results. The
inset shows the time spectrum in the entire time region
at 0.3 K.
Tl1-xKxCuCl3 (x = 0.20)

0.12

λ (µsec-1)

Field-induced magnetic ordering has been investigated extensively TlCuCl3 and KCuCl3 , and theobtained results are qualitatively well described by
the magnon Bose-Einstein condensation theory1–4) .
Recently, the bond randomness effect on the singlet ground state was reported in the mixed system
Tl1−x Kx CuCl3 5,6) . In zero field (ZF), the ground state
has no gap (magnetic) in the mixed system, althoughboth the parent materials have finite excitation gaps
(nonmagnetic). Magnetization measurement results
indicate that this system is in a paramagnetic state
down to 1.8 K5) . Shindo et al. carried out specificheat measurements in magnetic fields, and observed
field-induced phase transitions that are described by
the Bose-Einstein condensation of triplets of Cu-3d
spins5,6) . They discussed the obtained phase diagram
in connection with the appearance of a new phase, theBose glass phase, in lower magnetic fields at T = 0
as argued by Fisher et al.7) In the mixed system, as
mentioned above, a gapped phase accompanied by zeromagnetization is absent. Thus, in zero field, the Bose
glass phase at T = 0 is possible although the Bose
glass phase generally appears between the gapped andordered phases. However, whether or not the Bose
glass phase exists in the zero-field on the mixed system Tl1−x Kx CuCl3 is not yet known. The purpose ofthis study is to investigate the magnetic properties ofTl1−x Kx CuCl3 at low temperatures by the muon-spinrelaxation (µSR) technique, and to probe a glimpse of
the evidence of the existence of the Bose glass phase.
µSR measurements were carried out at the RIKENRAL Muon Facility in the U.K. using a spin-polarized
pulsed positive surface-muon beam. Single crystals
used in this study were grown from a melt by the Bridgman method.
Figure 1 shows ZF-µSR time spectra of Tl1−x Kx CuCl3
with x = 0.20 in the earlier time region from 0 to
10 µsec at each temperature. The shape of the time
spectrum tends to change with decreasing temperature. The µSR time spectra are analyzed using thesimple function A0 e−λt GZ (∆, t), where A0 is the initialasymmetry and λ is the relaxation rate of the muonspin polarization. GZ (∆, t) is the static Kubo-Toyabe
function with a half width ∆ describing the distribution of the nuclear-dipole field at the muon site. All
the time spectra are well fitted by the above function,
as shown by solid lines in Fig. 1.

ZF - µSR

0.10

0.08

0.06
0.1

0.5 1

5 10
T (K)

50 100Fig. 2. Temperature dependence of the relaxation rate λ ofmuon spins. The solid line is a guide for the eye.

References
1) T. Nikuni et al.: Phys. Rev. Lett. 84, 5868 (2000).
2) H. Tanaka et al.: J. Phys. Soc. Jpn. 70, 939 (2001).
3) Ch. Rüegg et al.: Nature (London) 423, 62 (2003).
4) M. Matsumoto et al.: Phys. Rev. B 40, 054423 (2004).
5) A. Oosawa et al.: Phys. Rev. B 65, 184437 (2002).
6) Y. Shindo et al.: J. Phys. Soc. Jpn. 73, 2642 (2004).
7) M. P. A. Fisher et al.: Phys. Rev. B 40, 546 (1989).

- 222 -

1

RIKEN Accel. Prog. Rep. 40 (2007)µSR study of the randomness-induced new magnetic phase inTl(Cu1−x Mgx )Cl3
T. Suzuki, I. Watanabe, A. Oosawa,∗1 T. Goto,∗1 F. Yamada,∗2 and H. Tanaka∗2[Bose-Einstein condensation, the impurity effect, µSR]∗1∗2

in the crystal are in the ”static” state; however, they
are not freezing. These spins are slowly fluctuating at afrequency of ∼ 1 MHz at lower temperatures, although
the neutron measurement results have suggested themagnetically ordered state.
24

TlCu1-xMgxCl3 (x = 0.0026)
LF - µSR 80 mK

Asymmetry (%)

221000 gauss

20
18

100 gauss

16

20 gauss

14

ZF

12
0

3

6
Time (µs)

912Fig. 1. Time spectrum of the longitudinal-field muon-spinrelaxation (LF - µSR) of TlCu1−x Mgx Cl3 with x =0.0026 at 80 mK. Solid lines are fitted results.
0.4
Hloc = 25 gauss
f = 1.1 MHz

λ1 (µs-1)

0.3
0.2
0.1
0

1

10

100
H (gauss)

1000

Hloc = 230 gauss
f = 1.2 MHz30
λ2 (µs-1)

In TlCuCl3 and KCuCl3 , the neighboring spin
dimers couple antifferomagnetically, and the magnetic
ground states are spin singlets with excitation gapsof 7.5 K and 31 K [1, 2]. In low magnetic fields,
the magnetization goes to zero because of the singlet ground state. In high magnetic fields, however,
the magnetization begins to increase below the temperature TN . Neutron elastic scattering experiments
have revealed that the field-induced Néel ordering occurs and that the vertical component of spins orders antiferromagnetically[3]. This field-induced magnetic order can be represented as a Bose-Einsteincondensation (BEC) of excited triplets (magnons)
theoretically[4]. Recently, Tl(Cu1−x Mgx )Cl3 single
crystals into which the randomness (impurity) was
introduced were grown, and new intriguing phenomena observed by magnetization measurements werereported [5]. The magnetic phase transition to anordered state was observed by magnetization measurements in the zero-field limit, although the noimpurity TlCuCl3 was nonmagnetic. Neutron scattering measurements identified that the ordered stateis an antifferomagnetically ordered state. The purpose of this study is to investigate the magnetic
properties of the randomness-induced ordered state inTl(Cu1−x Mgx )Cl3 at low temperatures using the µSR
technique. µSR measurements were carried out at the
RIKEN-RAL Muon Facility in the U.K. using a spinpolarized pulsed positive surface-muon beam. The single crystals used in this study were grown from a meltby the Bridgman method.
Figure 1 shows the longitudinal-field muonspin-relaxation (LF - µSR) time spectrum inTl(Cu1−x Mgx )Cl3 with x = 0.0026 at 80 mK.
Time spectra are well fitted using the the threecomponent function A(t) = A1 exp(−λ1 t)GKT (∆, t) +A2 exp(−λ2 t) + A3 exp(−λ3 t). λ is the relaxation rateof the muon-spin polarization, and the GZ (∆, t) is
the static Kubo-Toyabe function. From the fitting results, we obtained the ratio of asymmetry as A1 : A2
:A3 = 18 : 56 : 26. Figure 2 shows the magnetic
field dependences of the relaxation rates λ1 and λ2 .
Both data are well fitted using the Redfield formula of2λ(H) = γµ2 Hlocτ /(1 + γµ2 H 2 τ 2 ). Local magnetic fields
Hloc at the muon site and their frequencies of fluctuation, f , are deduced from the fitting (shown in Fig.
2). These results indicate that 74% of the Cu-3d spins

20
10
0
0.1

1

10
100
H (gauss)

1000

Fig. 2. Longitudinal magnetic field dependence of themuon spin relaxation rates λ1 and λ2 . Solid lines are
fitted results.

References

Department of Physics, Sophia University
Department of Physics, Tokyo Institute of Technology- 223 -

1) H. Tanaka et al.: J. Phys. Soc. Jpn. 70, 939 (2001).
2) A. Oosawa et al.: Phys. Rev. B 66, 104405 (2002).
3) A. Oosawa et al.: Phys. Rev. B 65, 184437 (2002).
4) T. Nikuni et al.: Phys. Rev. Lett. 84, 5868 (2000).
5) A. Oosawa et al.: Phys. Rev. B 66, 020405(R) (2002).

1

RIKEN Accel. Prog. Rep. 40 (2007)

Magnetic ordering in solid solution of two spin gap systems(CH3)2CHNH3CuCl3 and (CH3)2CHNH3CuBr3†
T. Goto*, T. Saito*, A. Oosawa*, T. Suzuki, I. Watanabe5

x=0.85
ZF

4
3
2

0.1

1
0

1

−1

1) H. Manaka et al.: Phys. Rev. B63, 104408 (2001).
2) T. Saito et al.: Phys. Rev. B74, 134423 (2006).

0.6

0.01

0.1

＊

0.4
0.3
0.2

β=0.330.1

510Temperature (K)00FIG. 1. Temperature dependence of the rotation
frequency ν and the relaxation rate λ.
†x=0.95 LF100(Oe)

0.5

0.33
0.367

1−T/T N00

References

λ(μsec−1)

ν(Τ ) /ν(0)Frequency (MHz)5λ (μsec )10

The two single crystals with x=0.85 and one with
x=0.95 were used for muon measurements. They wereattached by using Apiezon N grease on the silver platewith a purity of four nines, connected at the bottom of
the cryostat.
The sample with x=0.85 showed a clear muon spinrotation at low temperatures, demonstrating the existenceof a static long-range magnetic order. Relaxation
curves are fit to the function exp(−λt)cos(2πνt+φ), whereλ, ν, and φ are fitting parameters, corresponding to theinhomogeneity of the local field, the mean value of thelocal field, and the phase constant. Figure 1 shows thetemperature dependences of ν and λ. The inset shows ascaling function (1−T/TN)β fitted to the data to obtain thetransition temperature TN=11.65(±0.05) K and thecritical exponent β=0.33(±0.02), which agrees with the
3D-Ising model. The local field of the muon site at
0.33 K is estimated to be Hloc=360 Oe.
The sample with x=0.95 showed no rotation at low
temperatures down to 0.3 K.
However, λ showed asignificant increase, indicating the existence of a criticalinstability toward the quantum critical point and hence
the magnetic ground state of x=0.95. The characteristicfrequency and amplitude of the fluctuating local field
were estimated from the LF experiments to be 2.3 MHz
and 55 Oe respectively. These results make a clear
contrast with results of macroscopic measurements 1,
which determine that x=0.95 is in a gapped state.

Asymmetry (%) offset 1%

Quantum spin fluctuation destabilizes the magnetic
order even at absolute zero, and often brings a new
ground state completely different from what is expected
in a classical picture. In fact, many low-dimensional
spin systems with antiferromagnetic interaction have thegappedsingletstate.
Title
compounds
and(CH3)2CHNH3-CuBr3(CH3)2CHNH3-CuCl3
abbreviated as IPA-CuX3 are typical one dimensional
spin systems, which have the non magnetic ground state
The origin of thewith an energy gap at zero field1.
energy gap is quite different in the two systems of X=Br
and Cl. In the X=Br system, neighboring two spinsinteract antiferromagnetically to form a singlet dimer,while in the X=Cl system, there are a ferromagnetic(strong) and antiferromagnetic (weak) bond alternations
along the one-dimensional chain, so that each twoneighboring spins form effective S=1 spins, which
realize the Haldane state with a spin gap. The purposeof this study2 is to investigate the ground state of thesolid solution of these two nonmagnetic compounds.
Single crystals of IPA-Cu(ClxBr1−x)3 with x=0.85 and0.95 were grown by an evaporation method. The
mixing ratio x in the crystals was determined by the
inductively coupled plasma (ICP) method. The outershape of the crystals was a rectangular solid.
Measurements of μSR were carried out at the
Riken-RAL Muon Facility in the U.K. using a
spin-polarized pulsed surface-muon (μ+) with amomentum of 27 MeV/c.

2

10K
5K
4K
3K

25
20

2K
15
0

0.33K
2 4 6 8 10Time (μsec)

468Temperature (K)10

FIG. 2. Temperature dependence of λin the sample x=0.95.

Condensed from the article in Phys. Rev. B74, 134423 (2006)
Faculty of Science and Technology, Sophia University- 224 -

RIKEN
Prog. Rep.
Rep. 3940 (2006)(2007)RIKENAccel.
Accel. Prog.

µSR studies of sulfospinel CuCrZrS4
H.S. Suzuki,∗1 T. Furubayashi,∗1 Y. Kawashima,∗2 S. Nagata,∗2 T. Suzuki,∗3 I. Watanabe,∗3 and T. Matsuzaki∗3∗2∗3

National Institute for Materials Science, NIMS
Department of Materials Science and Engineering, MuroranInstitute of Technology
Advanced Meson Science Laboratory, Nishina Center for
Accelerator-based Science, RIKEN

0.15

-1

λ1 (µsec )

λ1
λ2
10

0.10

5

0.05

-1

∗1

15

λ2 (µsec )A novel spinel compound, CuCrZrS4 , is suggested toshow the ferromagnetically ordered state with a Curie
temperature of 54 K1) . An interesting feature of thiscompound is the very large negative magnetoresistance(MR)2) with the ratio reaching 80 at 16 K in a magnetic field of 90 kOe. The spin alignment of the suggested ferromagnetically ordered state has not beenclarified yet, so that the mechanism of the negative
MR is still unknown. Since the magnetization of thissystem in the ferromagnetic state is rather small, anovel unconventional magnetically ordered state may
be expected to appear at lower temperatures below
about 60 K. In addition, a spin glass behavior has
been reported below 10 K suggesting the existence of are-entrant magnetic behavior from an unconventional
magnetically ordered state.
The purpose of this work is to confirm the appearance of an unconventional magnetically ordered statein the expected ferromagnetic phase and the re-entrant
to a spin-glass state by µSR measurements under azero-field condition, obtaining information of the magnetic property from the microscopic viewpoint to argue
the mechanism of the large negative MR.
A powder sample of CuCrZrS4 was prepared by direct solid-state reaction1) . µSR measurements werecarried out using AUGUS spectrometer at RIKENRAL Muon Facility.
We have observed characteristic changes in the time
spectrum of the zero-field muon-spin relaxation at eachmagnetic phase boundary. Above 30 K, the time
spectrum was analyzed using the simple function as
A0 exp(-λt)GZ (∆,t), where A0 is the initial asymmetry, λ is the relaxation ratio and GZ (∆,t) is the static
Kubo-Toyobe function. Below 60 K, the relaxation
rate λ was increased rapidly with the decrease of thetemperature, as shown in Fig.1. In this first magnetic
phase (FM1) between 10 K and 60 K, no oscillations
were shown in the time spectrum. The enhancement of
λ at approximately 60 K without oscillation in the time
spectrum indicates a partial ferromagnetic ordering at
approximately 60 K. Below 30 K, the time spectrumof the relaxation was well reproduced by 2 componentsof the relaxation rate, i.e., fast depolarization behavior started to appear. In the second magnetic phase
below 10 K (FM2), the relaxation rate of the fast depolarization component was increased rapidly with thedecrease of the temperature, as shown in Fig.1, indicat-

04 5 6 71023

4 5 6 7

100

2

0.00

T (K)
Fig. 1. Temperature dependence of zero-field muon-spinrelaxation rate λ of muon spins.

ing that the internal exchange field is enhanced. The
ferromagnetic ordering with a long range is a candidateof the origin of the enhancement of the exchange field.
We could not, however, confirm oscillation in the time
spectrum because the relaxation of the fast component
is too fast for the pulse µSR measurement.
The longitudinal magnetic field dependence of thetime spectrum in the FM1 phase has shown interesting behavior. In the FM1 phase, the time spectrum of
the relaxation had 2 components of the relaxation rate
under the magnetic field, which were similar to those in
the FM2 phase as mentioned above. Moreover, the relaxation rate of the fast depolarization component below about 100 Oe was enhanced by the magnetic field.
This unusual response by the magnetic field implies
that the magnetic field introduces the development ofa ferromagnetic correlation in each partial ferromagnetic area, i.e., ferromagnetic domain, which seems to
be coupled antiferromagnetically to each other. This
competition between the ferromagnetic coupling in thedomain and the antiferromagnetic coupling among thedomains can be a candidate for the origin of the large
negative MR in this system.
References
1) Y. Iijima et al.: Phil. Mag. 83, 2521 (2003).
2) T. Furubayashi et al.: Solid State Commun. 131, 505(2004).

- 225 -

1

RIKENAccel.
Accel. Prog. Rep.
Rep. 39(2006)RIKEN
40 (2007)

Magnetic properties of S=1/2 quantum spin system on kagomélattice Cu-titmb
S. Ohira-Kawamura,∗1 R. Kaji,∗2 T. Itou,∗2 and S. Maegawa∗2[Quantum spin system, Kagomé lattice antiferromagnet, muon spin relaxation]
tigate its magnetic properties.
Figure 1 shows the ZF-µSR time spectra of Cutitmb. No clear change was observed at temperaturesfrom 80 K to 0.32 K. The dynamical fluctuations of
Cu spins can be extracted by fitting the spectra to therelaxation function, A(t) = AGKT (∆, t)e−λt , where
GKT (∆, t) is the Kubo-Toyabe function for describinga random static field due to nuclear dipoles and λ is themuon spin relaxation rate. The temperature dependence of the relaxation rate λ is shown in Fig. 2. The

Relaxation rate (µs−1)

The geometrical frustration of magnetic interactions
gives rise to the cooperative behavior of spin systems.
Heisenberg antiferromagnets on a kagomé lattice are
known as strongly frustrated spin systems. In particular, an S=1/2 kagomé lattice system is even attractive,
because quantum effects play important roles in sucha system. [Cu3 (titmb)2 (CH3 CO2 )6 ]·H2 O (Cu-titmb)
is an S=1/2 quantum spin system on a kagomé lattice. A theoretical study has indicated that the system has a singlet ground state and a triplet excitedstate separated by an energy gap, which is filled withmany nonmagnetic states.1) However, in a static fieldmagnetization measurement, a magnetization plateau,
which indicates the existence of the energy gap, is notobserved.2) Neither a 1 H NMR measurement nor themagnetization measurement indicates the realizationof a singlet ground state. Moreover, a magnetization plateau appears in a pulsed field magnetization
measurement depending on the sweeping rate of themagnetic field.3) Namely, the M -H curve shows a hysteresis loop. These results suggest that the complex
cooperation of the ferromagnetic (FM) and antiferromagnetic (AFM) interactions exists in this system. We
performed a µSR measurement on Cu-titmb to inves-

0.45
0.40
0.35
0.30

ZF

0.25
0.20
0.2

0.5

1

2

5

10

20

50

Temperature (K)Fig. 2. Temperature dependence of muon spin relaxation
rate λ.

λ value is nearly constant independently of temperature down to 1 K, and then it starts to increase as thetemperature decreases. The enhancement of the muon
spin relaxation is expected to be attributable to the dynamical fluctuations of Cu spins. Because it is unclear
whether this enhancement indicates a quantum fluctuation or the onset of a particular critical slow-down
effect, we cannot conclusively determine the groundstate of this system at present. Recently, a specificheat measurement has indicated an FM transition at
59 mK. Our result might reveal the critical slow-down
effect associated with the FM transition.
References
Fig. 1. ZF-µSR time spectra of Cu-titmb. Solid lines are
the best fits to the relaxation function mentioned in the
text.
∗1
∗2

1) Ch. Waldtmann et al.: Eur. Phys. J. B 2, 501 (1998).
2) S. Kawahara et al.: J. Mag. Mag. Mat. 272, e999
(2004).
3) Y. Narumi et al.: Europhys. Lett. 65, 705 (2004).

Present address: Academic & Information Board, Ochanomizu University
Graduate School of Human and Environmental Studies, Kyoto University- 226 -

1

RIKEN Accel.
Accel. Prog.
RIKEN
Prog. Rep.
Rep.3940 (2006)(2007)µSR study on spin dynamics of Mn2III-NiII Single-Chain Magnet
H. Miyasaka,∗1 A. Saitoh,∗2 and S. Ohira-Kawamura∗3[Single chain magnet, one-dimensional ferromagnetic chain, muon spin relaxation]
Single-chain magnets (SCMs) are the current focus
of many research groups, as well as single-moleculemagnets (SMMs), in the field of molecule-based magnetism. SCM is a one-dimensional (1D) spin system
consisting of high-spin units with a uniaxial anisotropy.
II
The MnIII
2 -Ni SCM forms the S = 3 trimer units ofIII
II
Mn -Ni -MnIII with antiferromagnetic (AFM) couplings, and a weak ferromagnetic (FM) interaction
exists between the units, as shown in Fig. 1. We
have performed µSR measurements on the SCM system [Mn2 (saltmen)2 Ni(pao)2 (py)2 ](PF6 )2 1,2) to understand its characteristic spin dynamics. The SMM
system [Mn2 (5-Clsaltmen)2 Ni(pao)2 (phen)](ClO4 )2 ,3)
where only the intraunit AFM interaction exists, wasalso measured for comparison.

(a)λ (µs−1)

10

5

β

1.00

(b)

0.5

0.0

0

20

40

60

80

T (K)
Fig. 2. Temperature dependences of (a) muon spin relaxation rate λ and (b) index β. The closed and open circles indicate the results of the SCM and SMM systems,
respectively.

II
Fig. 1. Structure of MnIII
single-chain magnet.
2 -Ni

The ZF-µSR time spectra (not shown) are well fitted with the stretched exponential function, A(t) =β
A0 e−(λt) , where A0 is the initial asymmetry, λ is themuon spin relaxation rate, and β is the index for describing the shape of the time spectra. The temperature dependences of λ and β are shown in Figs. 2(a)and (b), respectively, The closed and open circles indicate the results as in Fig. 2 legend. In both the SCM
and SMM systems, an enhancement of the muon spin
relaxation is observed. λ diverges at approximately 10
K, indicating that the spin fluctuation of the S = 3
units of MnIII -NiII -MnIII is suppressed across the frequency range of µSR (on the order of MHz). It is in∗1
∗2
∗3

Department of Chemistry, Tohoku University
Department of Chemistry, Tokyo Metropolitan University
Present address: Academic & Information Board, Ochanomizu University

teresting that the slope of the temperature-dependent
β for the SCM changes at ∼20 K. Because the SCM
system then behaves as a 1D FM system with S = 3
below ∼20 K, the fluctuation will be even more suppressed.
The magnetic correlation within the chain grows toachieve a finite chain length because of the strong uniaxial anisotropy, and the system exhibits a slow magnetic relaxation at low temperatures. The “spin-fliptype” relaxation is suggested for the model of this relaxation.4) We currently expect a certain complicatedrelaxation due to both the spin flip and the spin wave,
based on the longitudinal-field decoupling result.
References
1) R. Clérac et al.: J. Am. Chem. Soc. 124, 12837 (2002).
2) H. Miyasaka et al.: Inorg. Chem. 42, 8203 (2003).
3) H. Miyasaka et al.: Chem. Eur. J. 11, 1592 (2005).
4) R. J. Glauber: J. Math. Phys. 4, 294 (1963).

- 227 -

1

RIKEN Accel. Prog. Rep. 40 (2007)µSR studies of the ground state of a new spin-ladder material
A. Kikkawa,∗1 K. Katsumata,∗1 Z. Honda,∗2 I. Watanabe,∗3 T. Suzuki,∗3 and T. Matsuzaki,∗3[µSR, spin ladder, quantum phase transition]
A spin-ladder material, in which linear-chain antiferromagnets are coupled with an inter-chain exchangeinteraction, has attracted much attention in recent
years. The ground state of a two-leg antiferromagnetic spin-ladder is a singlet with an energy gap (spingap) to the lowest excited state. In a real material,
because of the presence of an inter-ladder exchange interaction, J 0 , magnetic long-range order is observed
1,2). The effect of an inter-ladder interaction on thephase transition in a spin, S = 12 two-leg Heisenberg antiferromagnetic ladder has been studied theoretically3,4) . Troyer et al.4) have shown that a quantum phase transition (QPT) from a disordered to Néelstates occurs at a critical value of J 0 /J ' 0.11, where,
J is the exchange interaction within the ladder. In aprevious paper5) , we showed that a spin ladder compound, Na2 Co2 (C2 O4 )3 (H2 O)2 (abbreviated to SCO,
hereafter) is a candidate material exhibiting this QPT.
In order to obtain direct microscopic evidence for the
QPT, we have made positive muon spin-relaxation(µ+ SR) measurements on SCO.
Muon spin-relaxation measurements were conductedat the RIKEN-RAL Muon Facility at the Rutherford
Appleton Laboratory. More than 400 single crystals
were glued on a silver plate, with their a axis parallelwith each other, using Apiezon N grease. The plate
was mounted in a 3 He cryostat.
Figure 1 shows the time spectra obtained at a longitudinal field (LF) of 3950 Oe and at the designatedtemperatures. At high temperatures, above about 80
K (not shown), the muon decay is completely suppressed by this field. At 40 K, we see a considerable
amount of muon spin relaxation and the relaxation becomes faster at 20 K. On lowering temperature further, the relaxation becomes slow and at the lowest
temperature (0.3 K) the time spectrum shows the relaxation is extremely slow. The µ+ spin relaxation atsuch a high field must come from electron spins andthe data show the fluctuation of the electron spins depends strongly on temperature. We fitted the data to
Gz (t) = B·exp[−(λt)β ], which reduces to the one obtained by Hayano et al.6) for β = 1 and to the one
given by McHenry et al.7) and by Uemura et al.8) for
β = 12 . Here, B is a constant.
From the analysis of the experimental data we draw
the following conclusions. We have successfully extracted information on the fluctuation of electron spins
by application of a strong longitudinal field. We find
∗1
∗2
∗3

Fig. 1. Temperature dependence of the µ+ spin decay of an assembly of single crystal samples of
Na2 Co2 (C2 O4 )3 (H2 O)2 measured at an LF of 3950 Oe.
The solid lines are the fit with the equation discussed
in the text.

that the µ+ spin relaxation rate, λ increases with decreasing temperature and shows a peak at Tpeak ' 18
K. Below Tpeak , λ decreases with decreasing temperature. This indicates the observation of a spin gap
formation by µ+ SR technique. The approach of the
exponent β in the longitudinal relaxation function to
0.5 with decreasing temperature indicates a freezing of
dilute Co moments. We suggest that these dilute Co
moments arise from a many-body quantum effect witha help of the uniaxial anisotropy. The Co moments are
distributed uniformly at lattice sites and fluctuate intime. Below about 5 K, we observe a sinusoidal oscillation in the time spectrum, which indicates an onsetof a long-range magnetic order. All these experimental
results give a microscopic evidence that the material
SCO is Néel ordered at low temperatures and is close
to the quantum critical point separating a spin liquid
and Néel ordered phases.
References
1) S. Matsumoto et al.: Phys. Rev. B 53, R11942 (1996).
2) R. Kadono et al.: Phys. Rev. B 54, R9628 (1996).
3) B. Normand and T. M. Rice: Phys. Rev. B 54, 7180
(1996).
4) M. Troyer et al.: Phys. Rev. B 55, R6117 (1997).
5) Z. Honda et al.: Phys. Rev. Lett. 95, 087204 (2005).
6) R. S. Hayano et al.: Phys. Rev. B 20, 850 (1979).
7) M. R. McHenry et al.: Phys. Rev. B 5, 2958 (1972).
8) Y. J. Uemura et al.: Phys. Rev. B 31, 546 (1985).

RIKEN SPring-8 Center, Harima Institute
Faculty of Engineering, Saitama University
Advanced Meson Science Laboratory, RIKEN- 228 -

1

RIKEN40 (2007)RIKENAccel.
Accel. Prog. Rep.
Rep. 39(2006)µSR study of ferromagnetic ﬁlled skutterudite compound SmFe4 P12 †Y. Kohori,∗1 K. Hachitani,∗1,∗2 H. Fukazawa,∗1 I. Watanabe,∗2 C. Sekine,∗3 and I. Shirotani,∗3[SmFe4 P12 , µSR, ferromagnetic order]
Filled skutterudite compound RT4 X12 (R: rareearth, actinide, T : Fe, Ru, and Os, X: P, As and Sb)
crystallizes in the body-centered cubic (BCC) structure of the space group Im 3̄ (No. 204). These compounds have recently attracted much attention as the
improved thermoelectric materials and for their wide
variety of the electrical and magnetic properties, suchas the magnetic ordering (ferro-/antiferro-magnetism),
the superconductivity, the metal-insulator transition,
the heavy fermion and the non-Fermi-liquid behaviors.
Among them, SmFe4 P12 was reported to exhibit theheavy fermion behavior with the ferromagnetic groundstate.1,2) The susceptibility and speciﬁc heat measurements show that Sm ions are in trivalent state andthe system has the magnetic ground state below 1.6
K. Here, we report microscopic magnetic properties
of SmFe4 P12 obtained by muon spin resonance (µSR)
measurements. The µSR technique is crucial for the
study of the magnetic property of the system in zeroexternal ﬁeld.
Figure 1 shows the temperature T dependence of the
ZF-µSR spectra between 0.31 and 10 K. With decreasing T , the depolarization of muon spins becomes very
rapid untill 1.6 K, which reﬂects the critical slowing
down phenomenon at the Curie temperature. Withfurther decreasing T , the spontaneous precession ofmuon spins was observed as shown in Fig.2. The corresponding internal ﬁeld is 650 Oe. The µSR measurment clearly shows apearence of the spontaneous
magnetic order at 1.6 K in SmFe4 P12 .

Fig. 1. ZF-µSR spectra at several temperature.

References
1) N. Takeda and M. Ishikawa: J. Phys.: Condens. Matter
15 (2003) 229.
2) K. Matsuhira, Y. Hinatsu, C. Sekine, T. Togashi, H.
Maki, I. Shirotani, H. Kitazawa, T. Takamasu and G.
Kido: J. Phys. Soc. Jpn., 71 (2002) Supple. 237.

†
∗1
∗2
∗3

Condensed from the article in J. Phy. Soc. Jpn. 75 (2006)
124717.
Graduate School of Science and Technology, Chiba University
Advanced Meson Science Laboratory, RIKEN
Department of Electrical and Engineering, Muroran Institute of Technology- 229 -

Fig. 2. ZF–µSR spectra at 0.31K.

1

RIKEN40 (2007)RIKENAccel.
Accel. Prog. Rep.
Rep. 39(2006)

Possible octupolar order in ﬁlled skutterudite SmRu4 P12probed by muon spin relaxation†
K. Hachitani,∗1∗2 H. Fukazawa,∗1∗3 Y. Kohori,∗1∗3 I. Watanabe,∗2 C. Sekine∗4 and I. Shirotani∗1,∗2
SmRu4 P12 is one of the most interesting systems inthe ﬁlled skutterudites RT4 X12 (R: rare earth, actinoid; T : Fe, Ru, Os; X: P, As, Sb), which have attracted considerable attention because of their various
remarkable phenomena.1) This system was reported to
exhibit a metal-insulator (M-I) transition at a TMI of
16.5 K.2) It has been considered that the antiferroquadrupolar (AFQ) order and the following antiferromagnetic (AFM) one successively occur below TMI anda TN of 15 K in the zero ﬁeld (ZF), respectively.3,4) The
transition temperatures show characteristic magnetic
ﬁeld dependence.4)
In order to explain the phase diagram, the octupolarorder is recently suggested as a probable candidate forthe order parameter below TMI from elastic constantmeasurements and group-theoretical considerations.5)
In this case, the time reversal symmetry (TRS) shouldbe spontaneously broken below TMI , on the contrary,TRS is not broken in the case of the AFQ order. The
31
P-NMR measurements in low magnetic ﬁelds suggest that the order is “magnetic” but not “nonmagnetic” AFQ.6) Note that a measurement in the absolutely zero ﬁeld is necessary to conﬁrm whether TRS
is spontaneously broken. However, 31 P-NMR cannot
be performed in ZF.
Thus, µSRs in ZF and in longitudinal ﬁelds (LFs)
have been carried out in order to clarify the transition at TMI . In this paper, we report the results ofmeasurements on SmRu4 P12 .
A single-phase polycrystalline SmRu4 P12 sample
was synthesized at high temperatures and high pressures.2) The sample was crushed to a powder for theexperiments. The experiments were performed by implanting pulsed surface positive muons into the sample. In the ZF-µSR experiment, the residual ﬁeld at
the sample position was suppressed to less than 0.03 Oe
using correction coils, which is suﬃciently small for our
measurement. The LF-µSR experiment was performed
by applying ﬁelds along the initial muon-spin.
In the ZF-µSR time spectra obtained, the muonspin precession was observed at low temperatures below about 5 K, which indicates that the ground state isa magnetically ordered state. The spectra above TMI
gradually decreases with time, and the decrease be†
∗1
∗2
∗3
∗4

Summarized from the article in Phys. Rev. B 73, 052408(2006)
Graduate School of Science and Technology, Chiba University
Advanced Meson Science Laboratory, RIKEN
Department of Physics, Faculty of Science, Chiba University
Department of Electrical and Electronic Engineering, Muroran Institute of Technology

Fig. 1. Temperature dependence of Hint in SmRu4 P12 estimated from LF-µSR.

comes rapid at temperatures below about TMI . Boththe initial asymmetry and the muon-spin relaxation
rate obtained by analyzing the spectra exhibit ananomaly around TMI . Since the precession was notclearly observed just below TMI , LF-µSR was also performed in order to conﬁrm whether the anomaly is dueto the appearance of a static internal ﬁeld. The LFspectra below TMI show the decoupling pattern observed in the case of a static internal ﬁeld. The magnitudes of the internal ﬁelds (Hint ) at several temperatures (T ) were estimated by analyzing the spectra. As
shown in Fig. 1, the static internal ﬁeld appears below
TMI .
These results indicate that the order below TMI is
not AFQ but magnetic. This means the spontaneous
TRS breakdown below TMI , which supports a scenario
in which the octupolar order occurs below the temperature in SmRu4 P12 .7)
References
1) W. Jeitschko and D. Braun: Acta Crystallogr. Sect. B
33, 3401 (1977).
2) C. Sekine et al.: Science and Technology of High Pressure, ed. M. H. Manghnant et al. (Universities Press,
Hyderabad, 2000) p. 826.
3) K. Matsuhira et al.: J. Phys. Soc. Jpn. 71 Suppl., 237(2002).
4) C. Sekine et al.: Acta Phys. Pol. B 34, 983 (2003).
5) M. Yoshizawa et al.: J. Phys. Soc. Jpn. 74, 2141 (2005).
6) K. Hachitani et al.: J. Phys. Soc. Jpn. 75, 124712(2006).
7) K. Hachitani et al.: Phys. Rev. B 73, 052408 (2006).

- 230 -

1

RIKEN Accel. Prog. Rep. 40 (2007)µSR study of ferrimagnetism on K clusters in low-silica X zeolite†
T. Nakano,∗1 K. Goto,∗1 J. Matsumoto,∗1 I. Watanabe, T. Suzuki, F. L. Pratt,∗2 and Y. Nozue∗1
Alkali metal clusters can be generated in the periodically arrayed nanospace of zeolite crystals. Ferromagnetism and antiferromagnetism have been found in K
clusters in zeolite A1) and Na clusters in sodalite2) , respectively. They are novel magnetic materials because
the magnetically ordered states are realized by the mutual interaction of s-electrons conﬁned in the clusters.
In the present work, ferrimagnetism is newly found in
K clusters in low-silica X (LSX) zeolite. The observed
magnetization is rather weak, but µSR study conﬁrms
the magnetic phase transition occurs in almost the fullvolume of the sample.
LSX is one of the aluminosilicate zeolites with the
FAU-type structure. The framework is constructed ofβ cages with the inside diameter of ∼ 7 Å, and supercages with the diameter of ∼ 13 Å are formed
among β cages, as shown in Fig. 1. Both types ofcages are arrayed in a diamond structure.
In this work, we used LSX with the chemical formula of Na4 K8 Al12 Si12 O48 in the structural unit of
the supercage, where Na+ and K+ ions are distributedin the space of the Al12 Si12 O48 framework (see Fig.
1). K clusters are formed by the loading of guest K
atoms into dehydrated zeolites via the sharing of the
4s-electrons among several K+ ions in the cage. The
number of guest K atoms per supercage (namely, 4selectrons per cluster), n, was changed from 0 to thesaturation value of ∼ 9.0. For the samples with 6.5 <n < 9.0, the temperature dependence of magnetization
is found to show a typical behavior of N-type ferrimagnetism. The Curie temperature, TC , varies depending
on n, and shows a maximum value of ∼ 20 K at n ∼ 7.8.
The observed spontaneous magnetization is as weak as∼ 0.1 µB per cluster. We performed µSR measure-+ments on the sample with n ∼ 6.8 and TC = 5 K at
the RIKEN-RAL Muon Facility. The zero-ﬁeld (ZF-)µSR spectra show a Gaussian-like relaxation above TC
due to the static random ﬁeld from nuclear magnetic
moments. With decreasing temperature, the spectral
shape changes to an exponential-like one. Throughout the whole temperature range, the spectra can beﬁtted by the product of the Kubo-Toyabe relaxation
function, GKT (t), and two exponential functions:
G(t) = [A1 exp(−λ1 t)+A2 exp(−λ2 t)]GKT (t)+B,(1)where B indicates the background. The exponential
terms can be assigned to the contribution of the electronic magnetic moment of K clusters. Figure 2 shows
the temperature dependence of relaxation rates, λ1 and
λ2 , which rise suddenly below TC of 5 K, indicating theappearance of an internal ﬁeld due to the magnetic
phase transition. The longitudinal-ﬁeld µSR spectra
conﬁrmed that the internal ﬁeld is almost static at 2
K. The ratio of the relaxation terms to the total asymmetry, (A1 + A2 )/(A1 + A2 + B), is estimated to be ∼0.7. This value is high enough to conclude that the internal ﬁeld under the magnetic phase transition arises
in almost the full volume of the sample.
For ferrimagnetism, we must consider nonequivalentmagnetic sublattices. We propose a model assumingthat two sublattices are formed by clusters in the βcages and supercages. We found that the internal-ﬁeld
distribution obtained from the ZF-µSR spectra is consistent with this model3) .

β cage

+
+

+
+

10
.8
Å
+

Si
Al
O
cation sites

Fig. 2. Temperature dependence of muon spin relaxation
rate obtained from ZF-µSR spectra for K clusters in
LSX zeolite with n ∼ 6.8.

Supercage of FAU

Fig. 1. Schematic illustration of the crystal structure of
low-silica X zeolite.
†∗1∗2

Condensed from the article in Physica B 374-375, 21 (2006)
Department of Physics, Osaka University
Rutherford Appleton Laboratory, UK

References
1) Y. Nozue et al.: Phys. Rev. Lett. 68, 3789 (1992).
2) V. I. Srdanov et al.: Phys. Rev. Lett. 80, 2449 (1998).
3) T. Nakano et al.: to be submitted.

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1

RIKEN Accel. Prog. Rep. 40 (2007)µSR study on nano sized cage material, 12CaO·7Al2 O3
Y. Miyake,∗1 Y. Ikedo,∗1 K. Hayashi,∗2 S. Matsuishi,∗2 M. Hirano,∗2 H. Hosono,∗2 K. Shimomura,∗1
K. Nishiyama,∗1 Y. Matsuda,∗3 and I. Watanabe∗3

We also performed LF decoupling experiments forboth samples in the range of 10 G to 4 kG at 5 K. We
observed almost identical decoupling curves for both
samples (see Fig. 2), and their hyperﬁne constants arealmost the same as that of Mu in vacuum, indicating
∗1
∗2
∗3

mSR

TF-

20 G
0.9

0.85

"Insulator""Semiconductor"
0.8
0

100

200

300

Temperature [K]Fig. 1. Temperature dependences of initial asymmetries
obtained from TF-µSR spectra. Solid circles represent
the ﬁt results for the spectra of “insulator” and open
squares show those of “semiconductor”.

yrtemmysa dezilamroN

To clarify the mechanism of the insulator-toconductor transition, we performed µSR experiments
to investigate muonium (Mu) and negative muonium
ion (Mu− ) states in C12A7. We focus on the dynamics of Mu because we can regard Mu as light isotopeof hydrogen. The experiments were carried out bothat Port 2 in RIKEN-RAL and at PiA port in KEK
using the pulsed positive surface muon beam. We prepared two samples: insulator (C12A7:H− ) and semiconductor (C12A7:H0 ); C12A7:H0 is the same crystal
as C12A7:H− but has already been irradiated with UVlight. To measure the Mu fraction for both samples,
TF-µSR experiments at 50 G have been carried out for
the temperature range of 4-300 K. We found that theasymmetry of the diamagnetic component of “insulator” was gradually decreased with decreasing temperature, while that of “semiconductor” was almost independent of T (see Fig. 1), and the missing fractions of
the asymmetries at 290 K of both samples were estimated to be 0.09 and 0.13, respectively.

0.95

yrtemmysa dezilamroN

We have been studying a mechanism of theinsulator-to-semiconductor transition of a novel material, 12CaO·7Al2 O3 (C12A7) using the µSR technique.
Crystalline C12A7 is a transparent insulating material that has twelve subnanometer-sized cages in theunit cell. Each cage has a mean eﬀective charge of+1/3 (+4 charge/12 cages), leading to the expectationthat such a positively charged cage behaves like an F +center upon capturing an electron. Hydrogen-treated
C12A7(C12A7:H− ), which encages a negative hydrogen ion in the cage, can be converted into an electricalconductor by irradiation with the ultraviolet light.1) A
possible mechanism for the photo induced conversion
is based on the idea that the ultraviolet irradiation induces an electron emission from the encaged H− ion,
(H− →H0 + e− ), and then an empty cage electrostatically captures the photo ionized electron and forms an
F+ -like center. As the electron is weakly bound in thecage, the wave function could spread spatially. Consequently, the electron may migrate throughout the
crystal by variable-range hopping.

1

mSR, 5 K

0.95

LF-

0.9

"Insulator""Semiconductor"

0.85
0

1000

2000

3000

4000

Field [G]Fig. 2. Longitudinal magnetic ﬁeld dependence of the initial asymmetries for both “insulator” (solid circle) and“semiconductor” (open square) samples.

that Mu exists in the same site in both samples. We
are trying to identify the sites of Mu and diamagnetic
muon in both samples by further analysis of LF- andZF-µSR spectra for C12A7 samples.
References
1) K. Hayashi, S. Matsuishi, T. Kamiya, M. Hirano andH. Hosono: Nature 419, 462 (2003).

Muon Science Laboratory, IMSS, KEK
Frontier Collaborative Research Center, Tokyo Institute ofTechnology
Advanced Meson Science Laboratory, RIKEN- 232 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Eﬀects of molecular adsorption on magnetism of edge state spins in
nanographite
K. Takahara,∗1 K. Takai,∗1 T. Enoki,∗1 F. L. Pratt,∗2 T. Suzuki,∗3 and I. Watanabe∗3
Nanosized systems, whose size is between thatof a molecule and that of a bulk solid, give a
new aspect in materials science. In particular, πelectron-based nanosized systems are of special interest. Nanographite is composed of a few sheets ofnanographene, which is defined as a nanosized flat πelectron system. In spite of the diamagnetic featuresof bulk graphite, nonbonding π-electron states (edgestates) due to the presence of open edges give localized
spin magnetism to nanographite. Activated carbon
fibers (ACFs), which consist of a disordered network of
nanographite domains, accommodate a large amountof guest species in nanopores between nanographite
domains. The molecular-adsorption-induced switchingeﬀect of nanomagnetism is the most interesting phenomenon among the various unconventional electronic
and magnetic properties of ACFs in connection withthe edge states. To investigate the detailed mechanism of the magnetic switching eﬀect microscopically,
we carried out μSR measurement using a specially designed vacuum-tight sample cell, in which ACFs can behandled in vacuum at temperatures up to 473 K andin a controlled atmosphere throughout a muon experiment. Here, we report the eﬀect of molecule adsorption
on the local magnetism of the nanographite network of
ACFs using argon, which is chemically inert and has
no nuclear dipole moment. These μSR measurements
were carried out at the RIKEN-RAL Muon Facility in
the Rutherford Appleton Laboratory.
To remove the adsorbed ambient gas species in thenanopores, ACFs were evacuated at a pressure of ca.
1×10−6 mbar at a temperature of 473 K for more than
48 h in advance. Subsequently, the nonadsorbed sample was kept in vacuum throughout the experiment.
For the argon-adsorbed sample, a suﬃcient amountof argon gas was introduced into the sample cell by
gradually decreasing the temperature to the boilingpoint of argon (87 K), and then the sample was valvesealed. Measurements were carried out in the temperature range from 3 K to 300 K at the magnetic fields
up to 3900 G.
For the nonadsorbed sample, ZF-μSR shows a
Lorentz-type depolarization behavior in the entire temperature range investigated. LF-μSR shows the complete decoupling of muon spins due to a local internal field of 20 G with the remaining depolarization
component, which cannot be decoupled by applying a
∗1
∗2
∗3

Department of Chemistry, Tokyo Institute of Technology
ISIS, RAL
Advanced Meson Science Laboratory, Nishina Center for
Accelerator-based Science, RIKEN

magnetic field of 3900 G. For the argon-adsorbed sample, ZF-μSR also shows the Lorentz-type depolarization behavior above at the boiling temperature of 87
K. On the other hand, a precession component clearly
appears below 80 K, as shown in Fig.1. The rotational field of the precession corresponds to 20 to 30
G depending on conditions. By applying even 1 G,
the precession component disappears and re-appears
by setting the field to 0 G. The behavior of LF-μSR
for the argon-adsorbed sample at a field higher than 1
G is the same as that for the nonadsorbed sample.
By considering the absence of the nuclear dipole moment in argon atom, the depolarization of muons injected into ACFs must have been caused by the local internal field of edge-state spins. The clear emergence of the rotational component suggests that argon adsorption induces a magnetic ordering with astatic internal field in a nanographite domain. A reduction in the inter-nanographene-sheet distance inthe nanographite domain, which is induced by argon
adsorption, is responsible for the enhancement of theexchange interaction between the edge-state spins on
nanographenes. This results in the development of thenovel magnetic order in the disordered nanographite
network. This remains an open question in comprehending the mechanism behind the disappearance of
the internal field by applying an extremely weak magnetic field.

Fig. 1. ZF- and LF-μSR time spectra of argon-adsorbed
sample. For clarity, the data at 80 K, 0 G and 80 K, 1
G are shifted up by 1.5 and 3, respectively.

- 233 -

1

RIKEN Accel. Prog. Rep. 40 (2007)µSR Study of CDW in Potassium
Haruhiko Suzuki䟼1, Yun Xue䟼1, Yoshifumi Nagasaki,

䟼1and Isao Watanabe

Since the prediction of a CDW state in alkali metals by The time spectra of asymmetry A0 were measured in theOverhauser in 19621), many groups have searched for this temperature range between 300 and 15 K, the lowest
state in these metals. However, no clear evidence has been temperature in our experiment. Unfortunately, the lowest
reported. Overhauser and coworkers claimed in many papers temperature of the specimen had a high, value probablythat they had observed CDW and electron-phason scattering owing to the large heat capacity of the sample holder.
effects2). However, these experimental results involved only
To determine the resonance between the muon spin andobserving a deviation from the isotropic Fermi sphere in nuclear quadrupole splitting of potassium due to the CDW
experiments. We attempted to observe the phase transition crystal distortion in a longitudinal field, the time spectra A0
in potassium at low temperatures. We have already were measured in various longitudinal magnetic fields. In
published our experimental results on magnetic this resonance experiment, we observed a certain anomaly,
susceptibility in potassium2). We also performed specific but it was not so clear. This should be due to the lowest
heat and X-ray diffraction analyses. All of these temperature being not low enough compared to theexperimental results show an anomalous behavior at around transition temperature. When we improve the cryogenic
20 K. The temperature dependence of the lattice constant of system and obtain lower temperatures, we expect topotassium shows the anomalous behavior, suggesting the observe clearer results.
crystal distortion from a bcc crystal at around 20 K. To
In zero field (ZF), µSR spectra did not show any marked
confirm the phase transition at 20 K, a muon spin rotation change in our measured temperature range. The time(µ+SR) experiment was performed between 15 and 300 K. spectrum of asymmetry A0 was well fitted to the
exponential damping function. However, after applying alarge magnetic field, such as 3000 Oe, a very rapid
relaxation was observed at temperatures below 19 K, as
shown in the figure. This result suggests the occurrence ofa phase transition at about 19 K, which is consistent with
our previous experimental results.
References
1) A. W. Overhauser: Phys. Rev. 128, 1437 (19621)., Review
article: A. W. Overhauser: Electron Correlation in Solids,
Molecules, and Atoms, edited by J. T. Devreese and F. Brosens( Plenum Publishing Corp., 1983) , p. 41.
2) M. Sekine, S. Abe, Y. Tanaka, S. Nakagawa, H. Suzuki, H.
Abe, K. Ohshima, and T. Nakajima: J. Low Temp. Phys. 101,
651 (1995).

䟼)HSFUWPHQWRI5K^VLHV0FQF̲F\F:QL[HUVLW^- 234 -

RIKEN Accel. Prog. Rep. 40 (2007)

Muon spin resonance study of shallow muonium in ZnO†
K. Shimomura,＊1 I. Watanabe, and T. Suzuki
Hydrogen is a ubiquitous impurity in mostsemiconductors, including elemental (e.g., Si), andcompound (e.g., GaAs) semiconductors. In these systems,
hydrogen is amphoteric, acting as an acceptor in n-type anda donor in p-type materials. In contrast, hydrogen can leadto electron conduction in some wide-gap semiconductors
such as zinc oxide (ZnO) semiconductors 1,2). The muonium
spin rotation method is now considered to be one of themost powerful techniques to experimentally investigate
these theoretical predictions. The muonium center (Mu; ananalog of isolated hydrogen whose proton is substituted
with a positive muon) is readily observed in a wide variety
of semiconductors after positive muon implantation, andhas been serving as a unique source of information on theelectronic structure of isolated hydrogen centers. Although
the dynamical aspect (e.g., diffusion property) may differ
considerably between Mu and H owing to the light mass ofMu (~1/9 that of H), the local electronic structure of Mu isvirtually equivalent to that of H after a small correction due
to the difference in the reduced mass (~0.4%). In this report,
we describe our recent studies of the isolated hydrogencenter in ZnO semiconductors using the muon spinresonance method in the RIKEN-RAL Muon Facility.
The ZnO semiconductor is one of the most promising
semiconductors for the next generation of electronic andoptoelectronic devices. It has already been applied intransducers, phosphors, and varistors, because of its uniquepiezoelectric, optical, and electrical properties. In theseapplications, polycrystalline material has mainly been used.
Moreover, recent progress in single-crystal growth has
opened up new possibilities, such as bright blue-light anduv-light emitters. Optical uv lasing has already been
observed even at room temperature.
In a previous paper 3), we reported that two species of Mu
centers with extremely small hyperfine (HF) parameters
were observed below 40 K. Both Mu centers have anaxial-symmetric HF structure along the c axis, indicatingthat they are located at the antibonding and bonding-centersites. It is inferred from their small ionization energies (~6and 50 meV) and HF parameters (~10-4-fold the vacuum
value) that these centers behave as shallow donors, strongly
suggesting that hydrogen is one of the primary origins of
n-type conductivity in as-grown ZnO semiconductors,
which was predicted in theoretical studies. However,another group reported only a single species of muonium
existing in ZnO semiconductors 4, 5). To further studiy of the†＊1existence of the second species, we performed muon spinresonance experiments, which are similar to typical NMR
methods.
The better frequency resolution, obtained by the weakradio frequency (RF) field (~1 G), allowing us todistinguish the signals from these muoniums. Figure 1
shows our preliminary results of RF measurements in ZnO,
where 50.000 MHz RF a and longitudinal magnetic_ field
were applied perpendicular and parallel to the [1120] axis,
respectively. Unfortunately, the preliminary analysis did not
distinguish two species of muonium, which might havebeen due to the inhomogenity of the applied static field.
Further improvements in what are required.

Fig. 1. Diamagnetic muon and muonium resonance spectrain ZnO at 2.0 K with_ 50 MHz RF field and 0.35 T static
field parallel to [1120] axis.
References
1)
2)
3)
4)
5)

Condensed from the article in Physisca. B 376-377, 444 (2006).
Institute of Material Structure Science, KEK- 235 -

C. G. Van de Walle, Phys. Rev.: Lett. 85, 1012 (2000).
C. G. Van de Walle et al.: Nature 423, 626 (2003).
K. Shimomura et al.: Phys Rev. Lett. 89, 255505 (2002).
S. F. J. Cox et al.: Phys Rev.Lett. 86, 2601 (2001).
J. M. Gil et al.: Phys Rev. B 64, 075205 (2001).

RIKEN Accel. Prog. Rep. 40 (2007)

Positive muons in calcium phosphate
T. Kakuyama, *1 M. K. Kubo, *1 I. Watanabe, T. Suzuki, Y. Kobayashi, A. Koda, *2 and K. Nishiyama *2
0.14

Relaxation rate / μs

–1

0.12
0.10
0.08
0.06
0.04
0

100
200
Temperature / K

300

Energy Accelerator Research Organization (KEK)

Fig. 1. Temperature dependence of relaxation rate ofdiamagnetic muon in TCP.
30
25
Asymmetry

A stable hydrogen atom was observed at room
temperature by an ESR study in X-ray-irradiated tricalcium
phosphate (β-Ca3(PO4)2, TCP).1) The authors suggested thatthe hydrogen atom occupied only one site and survived formonths. The purpose of this study is to investigate theformation and sites of muoniums and the behavior of
diamagnetic muons in TCP as analogues of neutralhydrogen atom and hydrogen ion, respectively. The μSR
method with its extremely high sensitivity is suitable forobtaining detailed information on the chemical and physicalbehaviors of trace amount of hydrogen in TCP.
The experiment was performed at port 2 of the
RIKEN-RAL Muon facility. The sample was prepared bypressing polycrystalline TCP (30 mm in diameter, 0.3
gcm-2) into a pellet and placing it in a He cryostat. A
positive muon beam was irradiated onto the sample, anddecay positrons were detected with a plastic scintillator
array. External magnetic fields perpendicular (transverse,
0.6 and 6.0 mT) or parallel (longitudinal, 0.1 to 380 mT) to
the initial muon spin direction were applied. Before
applying these fields, the geomagnetism in the sample space
was reduced to less than 1 μT. μSR measurements werecarried out at 290 K down to 8.8 K.
Precession spectra in a 6.0 mT transverse field were fitted
assuming a Gaussian spin relaxation due to the local
magnetic field originating from 31P nuclei. The yield of
diamagnetic muon was about 60% at 290 K, which
decreased to 50 % at 8.8 K. The relaxation rate of the spinpolarization of diamagnetic muon increased with decreasing
temperature from 0.06±0.01 μs-1 at 290 K to 0.12±0.01
μs-1 at 8.8 K (Fig. 1). This temperature dependence wasinterpreted to be a result of an increase in the correlation
time of the muon and 31P in TCP due to the decrease in the
hopping rate of diamagnetic muon.
Muoniums were detected by transverse field spin
precession in 0.6 mT transverse field at 290K. No clear
precession signals were observed at RIKEN-RAL; however,at KEK-MSL, muonium spin precession spectra wereobtained at 8 MHz under similar conditions. The muon
pulse width (70 ns) at RAL being larger than that (50 ns) at
KEK could obscure the fast precession signal.
Figure 2 shows μSR spectra with applied longitudinal
fields at 290 K. The initial asymmetry at t=0 increased as
the applied field increased. This increase was explained by
the decoupling of the muonium spin from the 31P dipole
moment, and the suppression of the fast spin relaxation ofparamagnetic muons.

20
15
10
5
0

0

2

4
6
Time / μs

810Fig. 2. μSR spectra of TCP during application of
longitudinal fields at 290 K ( ) 0 mT, ( ) 50 mT, and ( )380 mT.
In summary, good-quality μSR spectra of TCP can beobtained using positive muons. The formation of muoniums
in TCP was confirmed by the increase in the initialasymmetry in the longitudinal decoupling experiment. Thechanges in spin relaxation rate and asymmetry of
diamagnetic muons were understood from thetemperature-dependent muon hopping rate observed in TCP.
References
1) K. Nakashima and J. Yamauchi: J. Am. Chem. Soc. 127,
1606-1607 (2005).

*1

International Christian University*2

Meson Science Laboratory, Institute of Materials Structure Science, High- 236 -

RIKEN40 (2007)RIKENAccel.
Accel. Prog. Rep.
Rep. 39(2006)

RF-µ− SR on Si
I. Watanabe, K. Shimomura,∗1 and R. Scheuermann∗2[µSR, Hyperﬁne Interaction, RF]∗1∗2larization in an external ﬁeld around the resonancepoint. The depth of the ﬁeld dependence of muonspin polarization was observed at approxmately 3,330
G. The solid line in the ﬁgure is the best-ﬁt result of
the resonance curve using the Gaussian function. The
resonance ﬁeld obtained from the minimum of the resonance curve was 3,334±0.1 G. The resolution obtained
is about 10-fold higher than that obtained by TFµ− SR measurement1–3) . The hyperﬁne ﬁeld obtained
was less than 0.1 G. Thus, it is concluded that hyperﬁne interactions at Si-nuclear sites are almost zero at
300 K within experimental errors. Low-temperature
measurements are under way. We aim to determine achange in hyperﬁne ﬁelds at Si-nuclear sites below approximately 50 K, at which the unresolved fast electron
relaxation starts.

Sum of Asymmetry (arb. unit)

The investigation of hyperﬁne interactions at impurity centers in a semiconductor such as Si is interestingfor the fundamental science and technical applicationsof semiconductors. Accordingly, the importance of agood understanding of hyperﬁne interactions at acceptor centers is rapidly growing. However, the electron
paramagnetic resonance signal associated with acceptor centers is hardly observed because of fast electron
relaxation, and detailed investigations of hyperﬁne interactions at acceptor centers reamins one an importantance of study in the ﬁeld of semiconductors.
µSR measurement using negative muons (µ− SR)
is a powerful tool for studing hyperﬁne interactions at
nuclear sites in a material from a microscopic viewpoint. When µ− is implanted into a material, µ− sits
at a much deeper orbital than 1s because of its mass
being heavier than that of the electron (∼200 me ). Because of this deep orbital of µ− , the nuclear charge Z
is shielded to be Z-1 by the negative charge of µ− .
Therefore, the implanted spin-polarized µ− in Si is regarded as the acceptor center of Al (µAl) enabling us
to investigate hyperﬁne interactions at acceptor centers in Si. Some µ− SR measurements determine thehyperﬁne ﬁeld at the µAl site have been performed ina transverse ﬁeld (TF)1–3) . However, no agreements inthe value of the hyperﬁne ﬁeld at the µAl site and also
in the mechanism of hyperﬁne interactions at accepter
centers have been obtained yet. Thus, to resolve this,we carried out µ− -resonance measurement using radio
frequency (RF-µ− SR) at the RIKEN-RAL Muon Facility using an intense pulsed muon beam. RF-µSR
is a consderlably useful technique for determining directly hyperﬁne ﬁelds at the muon sites. Beucause anegative muon has a half-integer spin, the resonanceof the muon spin, which is the absorption of RF energy induced by the spin ﬂip of a muon, can be observed in external ﬁelds with RF. The hyperﬁne ﬁeld
at the µAl site can be calculated from this resonancefrequency. The gyromagnetic ration of a muon spinis 135.5 MHz/10kOe. This value is about four times
larger than that of a proton spin, so that the RF-µ− SRtechnique has a higher resolution rather than a normal
NMR technique.
Figure shows a resonance curve of RF-µ− SR on Si
at 45 MHz at 300 K. The external ﬁeld was applied
parallel to the muon-spin direction, and RF was applied perpendicular to the muon spin. The ”sum of
the asymmetry” means the degree of muon-spin po-

non-doped Si (un-guaranteed)from Furuya-Kinzoku in 2002
Asymmetry Sum. 2-6 usec
fixed bunching of 20
Lorentzian Fitting Impossible.
Gaussina fitting was applied.
RF: 45.000MHz, 200W

170
Si (non-doped)
250K, 45.000MHz

160
150
140
130
3290

3310

3330

3350

3370

Field (gauss)

Fig. 1. Resonance curve of RF-µ− SR on pure Si at 45 MHz
at 300 K.

References
1) M. Kock et al., Hyperﬁne Interact. 65, 1039 (1990).
2) T. N. Mamedov et al., Hyperﬁne Interact. 86, 717(1994).
3) T. N. Mamedov et al., J. Phys. Cond. Matt. 11, 2849
(1999).

Institute of Materials Structure Science, KEK, Japan
Muon Group, PSI, Switzerland- 237 1

RIKEN
Rep. 3940 (2007)RIKENAccel.
Accel. Prog. Rep.
(2006)µSR studies on a thin Nd0.5 Sr0.5 MnO3 film
Y. Matsuda, P. Bakule, I. Watanabe, Y. Miyake,∗1 Y. Murakami,∗2 M. Izumi,∗3 and K. Miyano,∗3[thin film, magnetism, perovskite]
Nd0.5 Sr0.5 MnO3 (NSMO) is one of the manganeseoxides with a perovskite-like structure, which has been
attracting interest in the last few years. The bulk crystals of NSMO are paramagnetic at room temperature,and show a ferromagnetic transition at 250K and a
successive antiferromagnetic transition at 170K witha very sharp metal-insulator transition. The groundstate of NSMO is the charge and orbital order (COO)
state, with CE-type antiferromagnetic spin texture. It
is known that when a small external field (magnetic
field, electric field, or light) is applied at the boundary
between the COO state and the ferromagnetic-metallic
state, the resistivity changes markedly, which has great
promise for device applications.
One of the obstacles preventing device application
was that it had been difficult to realize the COO statein thin films. Several attempts had been made to
grow NSMO thin films on substrates, but the properties of the obtained NSMO films appeared to be different from those of the bulk crystal, and there had
been no report of a clear metal-insulator transition until recently. Nakamura et al. succeeded in realizing
the COO state in NSMO film grown on (110)-oriented
SrTiO3 and observed a clear metal-insulator transition for the first time1) . The transition temperatureof 170K coincides with the COO transition temperature in bulk crystal. Following this, Wakabayashi et al.
conducted synchrotron x-ray diffraction measurement
on NSMO/SiTiO3 (110) and reported that there is anadditional transition at 140K, below which a novel typeof COO structure is realized2) .
Notably, Watanabe et al. presumes that the magnetic structure of the new COO state should be different from that of the ground state of the bulk crystal.
To investigate the magnetic property of NSMO thinfilm on SrTiO3 (110), particularly that of this novel orbital order structure, we carried out µSR measurement
using a newly constructed µSR spectrometer with alow-energy muon beam line at the RIKEN-RAL muon
facility3) . In contrast to conventional µSR experiments, which use polarized muons with a fixed kinetic
energy of 4MeV, our low-energy muon beam line canprovide variable implantation energy of 1-30 keV topolarized muons so that we can stop all of polarizedmuons in a thin film sample, without any penetration
into the substrates. This is a unique advantage of lowenergy muons, and this experiment is the first demon∗1∗2∗3

stration of this technique at the RIKEN-RAL muon
facility.
In the experiment, we used four NSMO films on(110)-oriented SrTiO3 . Each film was epitaxiallygrown by pulsed-laser deposition. The thickness ofthe films was about 100nm, and the size was 10mmby 10mm. Unfortunately, the available yield of lowenergy muons was only 5 ∼ 10/sec, because of the
reduced intensity of the initial muon beam due to a
failure in a beam transport magnet in the ISIS proton beam line. This severely limited the amount ofdata we were able to accumulate in the given beamtime. In spite of these circumstances, our preliminary result shows a clear paramagnetic to ferromagnetic transition at around 220K. This transition temperature is below that of bulk crystal, but is consistent
with a previous resistivity measurement of NSMO film
on SrTiO3 (110)1) . We also observed a change in theinitial asymmetry (and relaxation time) between 100K
and 155K, which may correspond to the newly discovered phase transition at 140K, but we need more data
points to form a definite conclusion. We hope to measure in detail the temperature variation of µSR time
spectra to reveal the magnetic properties in various
phases below 170K during the allocated beam time in
December 2006.
References
1) M. Nakamura, Y. Ogimoto, H. Tamaru, M. Izumi, andK. Miyano: Appl. Phys. Lett. 86, 182504 (2005).
2) Y. Wakabayashi, D. Bizen, H. Nakano, Y. Murakami,
M. Nakamura, Y. Ogimoto, K. Miyano, and H. Sawa:
Phys. Rev. Lett. 96, 017202 (2006).
3) P. Bakule, Y. Matsuda, M. Iwasaki, Y. Miyake, K.
Nagamine, Y. Ikedo, K. Shimomura, and P. Patrick:Physica B 374-375, 456 (2006).

High Energy Accelerator Research Organization
Faculty of Science, Tohoku University
Research Center for Advanced Science and Technology, theUniversity of Tokyo- 238 -

1

RIKENRIKENAccel.
Accel.Prog.
Prog.Rep.
Rep.4039(2007)(2006)Development of Gas-Pressurized Cell for High-Pressure µSR
Experiments at the RIKEN-RAL Muon Facility
I. Watanabe, and F.L. Pratt∗1[µSR, pressure]
The RIKEN-RAL Muon Facility can provide highermomentum muons of up to 120 MeV/c. One important
application of this higher-momentum muon beam isin high-pressure experiments. High-momentum muons
can be injected into a high-pressure cell to probe themagnetic properties of samples under pressure. Worldwide, only a few groups are working on high-pressureµSR experiments. However, because µSR can sense
magnetic properties of materials in the ideal zerofield condition, the demand for high-pressure µSR experiments has been growing recently to investigate
the magnetic properties of organic materials, strongly
correlated systems etc. Therefore, establishing highpressure experiments is very important and urgent toallow the further progress of scientific work at RIKENRAL and attract many users from Europe.
We have collaborated with the high-pressure groupof RAL since 2005 and have started to develop a highpressure cell that is pressurized using a gas. Such a system has been developed for neutron-scattering experiments at RAL. The RAL high-pressure group therefore
has a lot of experience using high-pressure systems.
The gas-pressurized system has an advantage in being able to change the pressure continuously without
any change in sample conditions. Also, the designed
system can be used with existing equipment at the
RIKEN-RAL Muon Facility.
¿From the upper limitation of the muon momentum
available at the RIKEN-RAL Muon Facility, we havedetermined the maximum pressure to be 7 kbar. Aftermuch discussion with the RAL high-pressure group,
we have produced the first test cell, as shown in Fig.
1. The gas is pressurized at the top of the cell andthe sample is mounted at the rear of the cell. The
inside pressure is held by a normal Bridgman clamp
and piston, which are located at the rear of the cell.
The material of the cell is CuBe. The diameter of thesample space is 18 mm and the depth is about 8 mm.
The sample volume is about 2 cc. The thickness of thewindow that muons pass through is 9 mm and the wall
can withstand pressures up to 10 kbar. The cell itself
can be cooled using an existing cryostat to about 2 K.
Any gas can be used to pressurize the samples, but weare planning to use helium.
Figure 2 shows the high-pressure compressor and intensifier set. The gas is compressed to up to 3 kbar
using the high-pressure compressor. When we needmore than 3 kbar, we use an additional intensifier. In∗1this case, the gas is compressed to up to 3 kbar using
the high-pressure compressor and the compressed gas
is finally pressurized by the intensifier to up to 7 kbar.
The pressure can easily be controlled by the numberof turns of the handle of the intensifier.
All the systems are now ready to be tested. We areplanning to carry out cooling and pressurization tests
in Feb. 2007. After the long shut down of RAL, we
will use this high-pressure system for experiments at
the RIKEN-RAL Muon Facility.

Fig. 1. Developed gas-pressurized high-pressure cell.

Fig. 2. High-pressure compressor and intensifier set used
to pressurize the cell.

Muon Group, ISIS, Rutherford Appleton Laboratory, UK- 239 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Performance of Gas-Jet Transport System Coupled to GARIS
H. Haba, D. Kaji, H. Kikunaga, N. Sato, T. Akiyama, K. Morimoto, A. Yoneda, K. Morita, T. Takabe,*1 and A. Shinohara*1＊1

The α-particle spectrum of 245Fm (4.2 s) separated using
GARIS and transported by the gas-jet is shown in Fig. 2. A
beam dose of 9.76×1016 was accumulated. The 8.15-MeV
peak of 245Fm is clearly identified under the desired low
background condition, although a large number ofbackground events are measured in SD even after the
GARIS separation. The background activities, such as thosefrom 211Bi and 211m,212mPo, which are produced in thetransfer reactions on 208Pb, are completely removed by thepresent system. The gas-jet efficiency of 245Fm isdetermined to be 83±9%.
The present results suggest that the GARIS/gas-jet
system is a promising tool for future SHE chemistry: theidentification of SHE nuclides under extremely low
background conditions, and high efficiencies of the gas-jet
transport. In the future, productions of SHE nuclides withlong half-lives for chemical experiments involving elements
such as 261Rf, 262Db, 265Sg, 269Hs, and 283112 will be
investigated using 238U and 248Cm targets.

2

Gas-jet efficiency / %

10

1

10

206

Fr with GARIS

173

W without GARIS

0

10 -3
10

-2

-1

10

0

10

10

Beam intensity / pμA

Fig. 1. Variation of gas-jet efficiency of 206Fr and 173W as
function of beam intensity.
50
8.150 245Fm

40
30
7.342 241Cf
7.730 245Es

Counts / 20 keV

We are developing a gas-jet transport system coupled to
the RIKEN gas-filled recoil ion separator GARIS to
perform superheavy element (SHE) chemistry in RIKEN.1)
In this work, the performance of the system was evaluatedusing 206Fr and 245Fm produced in the 169Tm(40Ar,3n)206Fr
and 208Pb(40Ar,3n)245Fm reactions, respectively.
The metallic 169Tm and 208Pb targets of 120 and 420 μg
cm–2 thicknesses, respectively, were prepared by vacuum
evaporation on 30 μg cm–2 carbon backing foils. The 40Ar
beam was supplied from the RIKEN linear accelerator. The
beam energies were 170 MeV for 169Tm and 199 MeV for208
Pb at the middle of the target. The typical beam intensity
was 2 particle μA (pμA). The reaction products of interest
were separated in-flight from the beam and the majority of
the nuclear transfer products by GARIS and were guided
into the gas-jet chamber of 70 mm i.d. × 60 mm length
through a Mylar vacuum window of 3.5 μm thickness. The
separator was filled with helium gas at a pressure of 88 Pa.
The magnetic rigidities of GARIS were set at 1.64 for 206Fr
and at 2.01 Tm for 245Fm.
In the gas-jet chamber, the reaction products were
stopped in helium gas, attached to KCl aerosols generated
by the sublimation of KCl powder at 620 oC, andcontinuously transported through a Teflon capillary (1.59mm i.d. × 4 m length) to a rotating wheel system for α
spectrometry (RIKEN MANON).1) The helium flow rate
was 5 L min–1, and the inner pressure of the chamber was
90 kPa. In MANON, the reaction products were deposited
onto Mylar foils of 0.68 μm thickness and 20 mm diameter
placed at the periphery of a 40-position stainless steel wheelof 420 mm diameter. After the aerosol collection, the wheel
was stepped at 30-s and 2-s intervals for 206Fr and 245Fm,
respectively, to position the foils between seven pairs of Si
PIN photodiodes (Hamamatsu S3204-09). To evaluate thenumber of 206Fr and 245Fm atoms that passed through theMylar window, the gas-jet chamber was replaced with adetector chamber equipped with a 12-strip Si detector of 60
× 60 mm2 (Hamamatsu 12CH SD).
In the α-particle spectra obtained using MANON and SD,
α peaks of 206Fr (T1/2 = 15.9 s) and 205Fr (3.85 s) and of theirdaughter nuclides, 202At (182 s; 184 s) and 201At (89 s),
were identified. In Fig. 1, the gas-jet efficiencies of 206Fr are
shown by closed circles as a function of 40Ar beam intensity.
High gas-jet efficiencies of over 90% are obtained. For acomparison, the open squares shown in Fig. 1 are the dataof 173W produced in the natGd(22Ne,xn) reaction with aconventional gas-jet system. Owing to the plasma condition
induced by the beam in the chamber, the gas-jet efficiencyof 173W decreases from 40% at 6.6 pnA to 25% at 0.5 pμA
with a 22Ne beam intensity. Since the primary beam isseparated using GARIS, such a decrease in gas-jet
efficiency is not seen for 206Fr up to 2 pμA.

20
10
0

6

7

8

9

10

Energy / MeV

11

12

Fig. 2. Sum of α-particle spectrum measured with MANONin the 208Pb(40Ar,3n)245Fm experiment (seven top detectors).
Reference
1) H. Haba et al.: RIKEN Accel. Prog. Rep. 39, 109 (2006).

Graduate School of Science, Osaka University- 241 -

RIKEN Accel. Prog. Rep. 40 (2007)

Heavy element production for chemical characterization of seaborgium
T. Takabe,*1 H. Haba, D. Kaji, H. Kikunaga, D. Saika,*1 K. Matsuo,*1 Y. Tashiro,*1 K. Ooe,*1 T. Kuribayashi,*1 T. Yoshimura,*1
A. Toyoshima,*2 H. Kudo,*3 T. Mitsugashira,*4 K. Morita and A. Shinohara*1*1Graduate School of Science, Osaka University*2

Advanced Science Research Center, Japan Atomic Energy Agency*3

Faculty of Science, Niigata University*4

Institute for Materials Research, Tohoku University

In the 261Rf experiment, a beam dose of 3.49×1016 wasaccumulated. Figure 1 shows the sum of the α-particle
spectra measured in the seven top detectors of MANON for
5 to 210 s after the 30-s aerosol collection. A total of 155
time-correlated α pairs of 261Rf (68 s, 8.28 MeV)3) and its
daughter 257No (25 s, 8.222 and 8.323 MeV)5) wereregistered in the α-energy range of interest. The gas-jet
efficiency of 261Rf in the present system was evaluated to be
74%, by referring to the cross section of 13 nb6) at 94 MeV.

60

40

20

11.650 212mPo

808.883 211mPo

7.995 211mPo
8.280 261Rf
8.222, 8.323 257No

100

Counts / 20 keV

In recent years, we have been constructing aheavy-element production system on the beam line of the
RIKEN K70 AVF Cyclotron to investigate chemical
properties of seaborgium (Sg, Z=106).1) Prior to the
production of the isotope 265Sg via the 248Cm(22Ne,5n)265Sg
reaction, the performance of the system we developed wasevaluated using 255No and 261Rf produced via the238
U(22Ne,5n)255No and 248Cm(18O,5n)261Rf reactions,
respectively, in this study.
A 238U target of 630 μg/cm2 thickness and a 248Cm targetof 480 μg/cm2 thickness were prepared by electrodeposition
onto a beryllium backing foil of 2.0 mg/cm2 thickness. The
beams first passed through a beryllium vacuum window(1.9–3.2 mg/cm2), the helium cooling gas (0.09 mg/cm2),
the beryllium target backing, and finally entered the target
material. The beam energies on target were 105.9, 107.3,
109.0, 113.4, 116.6, and 120.9 MeV for 22Ne and 94.4 MeV
for 18O. The beam intensity was approximately 350 pnA.
Reaction products recoiling out of the target were stopped
in helium gas at 130 kPa (98 kPa)2), attached to KCl
aerosols generated at 640oC (620oC)2), and transported
through a Teflon capillary of 2.0 mm i.d. and 45 m long (11m long)2) to the rotating wheel system MANON for α
spectrometry. The transported products were deposited onto
thin Myler foils of 0.68 μm thickness. The foils wereperiodically rotated to position the products between sevenpairs of Si PIN-photodiodes for α-particle detection. The
flow rate of helium gas was 2.0 L/min (5.0 L/min)2).
In the α spectrum, the α particles of 255No (T1/2 = 3.1 min,Eα = 7.620–8.312 MeV)3) were identified and theradioactivity of 255No was evaluated by the two-component
decay curve analysis of 255No and 254No (55 s, 8.093 MeV)3).
The gas-jet efficiency was determined to be 50% fromradioactivities of the daughter nuclide 255Fm by the catcher
foil method with chemical separation. It was found that the
maximum cross section of the 238U(22Ne,5n)255No reaction
is 90 nb at 113 MeV, although the excitation function
measured by Donets et al.4) shows the peak of 200 nb at 118
MeV. It is noted here that the measurements by Donets etal.4) were carried out on the basis of the α decay of thedaughter nuclide 251Fm only in ~1%. The peak cross section
corrected for the latest α-decay branch of 1.80%3) (~100 nb)
is in good agreement with the present result.

0
7

8

9

10

11

12

Energy / MeV

Fig. 1. Sum of α-particle spectra measured in the seven top
detectors of the rotating wheel system MANON for 5 to 210
s after the 30-s aerosol collection.
Reference
1) T. Takabe et al.: RIKEN Accel. Prog. Rep. 39, 113 (2006).
2) The values given in parentheses refer to the condition for the248
Cm(18O,5n)261Rf experiment.
3) R. B. Firestone and V. S. Shirley: Table of Isotopes, 8th edn.
(John Wiley and Sons, New York, 1996).
4) E. D. Donets et al.: Sov. J. Nucl. Phys. 2, 723 (1966).
5) M. Asai et al.: Phys. Rev. Lett. 95, 102502 (2005).
6) Y. Nagame et al.: J. Nucl. Radiochem. Sci. 3, 85 (2002).

- 242 -

RIKEN
Prog. Rep.
Rep. 3940 (2006)(2007)RIKEN Accel.
Accel. Prog.

Preparation of 83 Rb for 83 Kr Mössbauer Spectroscopy
M. K. Kubo,∗1 Y. Kobayashi, G. G. Pedoussaut∗1 Y. Yamada,∗2 and H. Haba
Krypton is one of the rare-gas (RG) elements. After
xenon was found to form fluorides and be not truly inert to chemical reactions, the first krypton compoundKrF2 was synthesized in 1963.1) Since then, there havebeen numerous studies on the synthesis of RG compounds and on the clarification of the nature of theirchemical bonds. On the basis of ab initio molecular orbital calculations, the nonfluorinated compound
HKrCl was prepared in 1995.2) There have been a
few attempts to prepare novel RG compounds containing RG-C bonds using the matrix-isolation-laserexcitation (MILE) technique.3) A reactant compound,e.g., hydrogen chloride is condensed onto a CsI substrate with a RG to form a reaction matrix. After condensation, the matrix is irradiated with a laser beam
to excite the reactant to form a RG compound. RG
compounds formed are confirmed by IR spectroscopy.
In such MILE experiments, there is a limitation thatone RG atom can form a chemical bond to only one
reactant molecule, since the reactant concentration is
kept low (molar ratio of RG / reactant ≥ 1000) in
order to observe clear IR spectra. Compounds withxenon and acetylene were prepared in 2003.4) Krypton compounds with a similar structure are believed
to exist on the basis of calculations, but have not been
experimentally confirmed.
Fortunately, krypton has the Mössbauer active nuclide 83 Kr. Mössbauer spectroscopy provides information on the valence state and electric field gradientat the Kr nucleus, complementary to IR spectroscopy,
which provides atom-atom bond parameters. With theaim of producing compounds consisting of one krypton and two or more reactant molecules beyond thescope of the dilute MILE condition, we have started a
new project on 83 Kr Mössbauer spectroscopy using the
RIKEN cyclotron. As the first step, we are setting up aMössbauer spectrometer for 83 Kr using a radioisotope
source, 83 Rb (T1/2 = 86.2 d).
The Mössbauer level of 83 Kr is the first excited state
at 9.396 keV. Above this level there is a metastablestate, 83m Kr, with a half-life of 1.83 h. There have been
83
Kr Mössbauer studies since the 1960s. Most of theprevious studies used 83 Rb as the radiation source embedded in solid matrices. We chose a 83m Kr source separated from 83 Rb to reduce the radiation backgroundfrom 83 Rb. Carrier-free 83m Kr deposited on a coldplate will enable us to obtain Mössbauer spectra ofgood quality.
A CaBr2 target was irradiated with an α particle∗1∗2

Department of Chemistry, International Christian University
Department of Chemistry, Tokyo University of Sciencebeam of 25 MeV energy. After the irradiation, thetarget was dissolved in water. Ammonium carbonate solution was added to precipitate and separate
most of the CaCO3 . Unfortunately, some of the aluminum cover foil merged into the target CaBr2 during
the beam irradiation. For the separation of aluminumand 83 Rb, we applied the ion exchange chromatography technique using a cation exchange resin Amberlite
IR-120B. By gradually changing the concentration ofeluent HCl, 83Rb was successfully separated from aluminum. A low-energy gamma-ray spectrum measured
with a CdZnTe detector is shown in Fig. 1. A 9.4 keV
peak from the first excited state of 83 Kr can be observed with Kr KX-ray peaks. An absorber Kr-quinone

Fig. 1. Gamma-ray spectrum of 83 Rb prepared.

clathrate was synthesized. Solid krypton was collected
in a vacuum trap cooled by liquid nitrogen. The solid
krypton was transferred to a stainless pressure vessel
with an inner teflon capsule containing concentratedhydroquinone aqueous solution and a spinner, and thecap of the vessel was tightly closed. The vessel was
slowly heated to 360 K. The increase in inner pressurecaused by the evaporation of krypton led to the formation of Kr-quinone clathrate. A small hexagonallycylindrical crystal was formed and collected by filtration.
For the next step, we will construct a gas handlingsystem for the extraction of 83m Kr and its condensation onto a cryohead, and measure 83 Kr Mössbauer
spectra.
References
1) J. J. Turner and G. C. Pimentel: Science 140, 974(1963).
2) M. Pettersson, J. Lundell, and M. Räsänen: J. Chem.
Phys. 102, 6423 (1995).
3) For example, M. Pettersson, J. Lundell, L. Khriachtchev, and M. Räsänen: J. Chem. Phys. 109, 618(1998).
4) L. Khriachtchev et al.: J. Amer. Chem. Soc. 125, 4695
(2003), V. I. Feldman et al.: J. Amer. Chem. Soc. 125,4698 (2003).

- 243 -

1

RIKEN Accel. Prog. Rep. 40 (2007)

Reactions o f 57 Mn Implanted into Solid Oxyg en at γ-Phase
Y. Kobayashi, H. Kato*1, J. Miyazaki*1, M. K. Kubo*2, H. Ueno, A. Yoshimi, K. Shimada*3, D. Nagae*3, K. Asahi,
and Y. Yamada*1
The novel chemical reactions of 57Mn atoms with oxygen
have been studied by in-beam Mössbauer spectroscopyusing a short-lived radioactive beam, 57Mn (T1/2=1.45 min).
The direct implantation of particles into an appropriate
substance produces various novel chemical species andexotic valence states unavailable under normal conditions.
In our previous study, a high valence state of Fe(VIII) was
obtained from the in-beam Mössbauer spectra of 57Fe/57Mn
implanted into KMnO4 at low temperatures.1) We havealso studied the in situ characterization of the reaction
products between Fe and oxygen by 57Fe/57 Mn implantation
Mössbauer spectroscopy, and succeeded in measuring the
Mössbauer spectra at 18 and 32 K. The spectra were fitted
to a combination of four doublets, assuming that the species
obtained by the reaction of Fe and O2 were simple ironoxide species.2) It is reported that solid O2 appears in α- (0≤ T ≤ 24 K), β- (24 ≤ T ≤ 44 K), and γ-phases (44 ≤ T ≤ 54K), and that α-O2 and β-O2 are antiferromagnetic, and γ-O2
is paramagnetic. A sextet might be observed in the spectra
if the magnetic hyperfine is produced by the
antiferromagnetism of solid α-O2 and β-O2, and it is also
possible to fit the spectra, assuming a combination of two
sextets. To confirm our previous assignments of theobserved spectra, the spectrum of 57Mn in paramagnetic
γ-O2 was measured. In this study, we measured the spectra
at a high temperature (45 K). The measured spectrum
showed similar doublet peaks and the absence of a sextet.
57
Mn particles were produced as a secondary RI beamfollowing the nuclear projectile fragmentation of 58Fe21+
beams (E = 63 MeV/nucleon, I = 40 pnA) accelerated by alinac and a ring cyclotron with a Be production target. 57Mn
was separated and focused by an in-flight isotope separator
using RIPS. Subsequently, 57Mn was implanted into a solid
O2 sample after passing through an Al plate with anappropriate thickness to reduce the beam energy to about 26
MeV/nucleon. The stopping range of 57Mn in the solid O2
sample was calculated to be 180 µm from the surface withthe straggling range of ±100 µm. The beam intensity of57
Mn was typically 5 × 106 particles/s.
The solid O2 sample was prepared on an Al plate (18 K).
The thickness of the sample was estimated to beapproximately 1 mm. To maintain the solid O2 sample at ahigh temperature without subliming, O2 gas was introduced
into a cryostat to compensate the loss of O2 solid at its
vapor pressure. The 14.4 keV γ-rays emitted from 57Mn
were detected by a parallel-plate avalanche counter (PPAC)
with an 57Fe-enriched stainless-steel foil.
The 57Fe/57Mn in-beam Mössbauer spectra were
measured at 45 K (paramagnetic γ-O2) during theimplantation of 57Mn. The counting time was 18 h. The total

implantation dose of 57 Mn was typically 5×1011 57Mn/cm2
for one spectrum. The spectra obtained at 45 K (Fig.1)
showed intense doublet peaks, which have the same
Mössbauer parameters as those observed at temperatures
lower than 45 K (18 and 35 K). Therefore, it was provedthat the Mössbauer spectra obtained in this study do notshow magnetic components. In our previous measurements,
the spectra obtained at 32 and 40 K had the components of
Fe in the Al substance, namely, a substitutional Fe atom andan interstitial Fe atom; some 57Mn particles reached the Al
substance when the thickness of solid O2 decreased as O2
molecules evaporated owing to a high vapor pressure at ahigh temperature. However, in this study, the components
of Fe in the Al substance were not observed because thethickness of solid O2 was kept constant by introducing O2
gas to the cryostat.
Our results for in-beam Mössbauer spectra indicated a
combination of Lorentzian doublets: FeO (S = 2), Fe(O2) (S= 1), (O2)FeO2 (S = 0), and Fe(O2)2 (S = 0). 2) Although anenergetic 57Mn atom certainly creates defects anddecomposes O2 molecules until it stops at a suitable final
position in solid O2, the 57Fe atom at the final position isneatly surrounded by O2 molecules, and Fe(O2)2 is obtained
as the primary 57Fe product.

Fig. 1 In-beam Mössbauer spectrum of 57Fe/57 Mn atoms
implanted into solid O2 at 45 K.
References
1) Y. Kobayashi et al.: J. Radiochem. Nucl. Chem. 255, 403(2003).
2) Y. Yamada et al.: Appl. Radiat. Isot. 52, 157 (2000).

㸟1
㸟2
㸟3

- 244 -

Department of Chemistry, Tokyo University of Science
College of Liberal Arts, International Christian University
Department of Physics, Tokyo Institute of Technology

RIKEN Accel. Prog. Rep. 40 (2007)

The Distribution and Metabolism of 14C –labelled Carnosine in MiceT. Ando,＊1 Y. Nakanishi,＊1 M. Suzuki,＊1 M. Ozaki,＊1 Y. Kanayama, S. Enomoto, and S. Kimura, ＊1＊1which did methylation, and also present in high concentrations in the muscle and brain of many animals and humans.
It has been shown that the amount of The taking % of theradioactivity that oral administered to blood and eachorganization was compared. After it had administered it, thekidney and the musculus soleus reached the highest value in
one hour, and the liver, the brain, the gastroceminal muscle,
and all bloods reached the highest value in three hours.
Afterwards, it decreased gradually and the same transition
was seen.
Liver

4500
4000
R a d io a c t iv it y ( c p m )R a d io a c t iv it y (c p m )Whole blood

1000
900
800
700
600
500
400
300
200
100
0

3500
3000
2500
2000
1500
1000
500
0

0

1

2

3

4

5

6

Time(h)780

9 10 11 123500

R a d io a v t iv it y (c p m )R a d io a c t iv it y (c p m )

4000
3000
2500
2000
1500
1000
500
0
0

1

2

3

4

5

6 7
Time(h)

1

2

3

4

5

6 7
Time(h)89 10 11 128

9 10 11 128

9 10 11 12

Brain(R)

Kidney
4500

8

1000
900
800
700
600
500
400
300
200
100
0
0

9 10 11 12

1

2

3

Soleus45

6 7
Time(h)Gastrocnemius
1000
900
800
700
600
500
400
300
200
100
0

1000
900
800
700
600
500
400
300
200
100
0

R a d io a c t iv it y (c p m )R a d io A c t iv it y (c p m )Carnosine(β-alanyl-L-histidine) is a histidine-containing
peptide particulaly abundant in exitable tissues such as
brain and skeletal muscle of humans and other mammal
animals at relatively high concentrations (up to 20 mM).
It has the potential to suppress many of the biochemicalchanges (e.g., protein oxidation, glycation, AGE formation,and cross-linking) that accompany aging and associatedpathologies. Through its distinctive combination ofantioxidant and antiglycating properties, carnosine is able toattenuate cellular oxidative stress and can inhibit the
intracellular formation of reactive oxygen species andreactive nitrogen species. Boldyrev et al. showed that
carnosine attenuated the development of senile features
when used as a supplement to a standard diet of senescenceaccelerated mice (SAM). Its effect was apparent on physicaland behavioral parameters and on average life span. In thepresent study, we show biodistribution and metabolism oforally administered radio-labelled carnosine in mice.
Carnosine, [β-alanine-3-14C, 2.4μCi/0.5ml] was orally
admiministered to fasted ddy mice (4 weeks-old, male).
After oral administration, mice were sacrificed by cutting
the cervix part at differenet time (1,3,6,12 or 24 h), andwhole blood were collected; liver, kidney, brain,
gastrocneminal muscle, and muscles soleus were removed
and weighed. Each organ and blood put in vials (PackardCo.) was solubilized by mixing with 6 ml of tissue
solubilizer (NCS-II, Amersham Pharmacia Biotech, Inc.)
with shaking whole day. Subsequently, each solubilized
sample was added 10 mL of liquid scintillation cocktail(OCS, Packard) and its radioactivity was counted in a liquid
scintillation counter (Packard Co.). The coloring liquid had
been bleached with CH3COO3 of the proper quantity before
OCS was added.
Biodistribution in organs and uptake of the radioactivity
that administered the oral into blood and each organ wereshown in Figure1.The radioactivities in organs showedsimilar transition during 24 hours.
After administering carnosine, its radioactivity reached thehighest value at 1 h in kidney and musculus soleus, while inliver, brain, Hifc muscle, and whole blood the highest
values were observed at 3 h. Then the elevated levels ofradioactivity present in the circulation at 1 h and 3 hpost-administration in musculus soleus, Hifc muscle, andwhole blood were reduced to near-background levels by 24
h post-administration. Relatively higher radioactivity wasobserved in liver and kidney, while it was lower in brain.
Uptake of its radioactivity in liver and kidney were 18% at
3 h and 16% at 1 h, respectively, although it in brain was
only 1.6% at 3 h.
Anserine(β-alanyl-L-methylhistidine) is a histidine containing dipeptides like carnosine, and carnosine and carnosine

0

1

2

3

4

5

6 7
Time(h)89 10 11 12

0

1

2

3

4

5 6 7
Time(h)Fig.1. Tissue concentration of Carnosine, [β-alanine-3-14C]
in ｄｄｙ ｍｉｃｅ at various time after injection.
References

1) K. Horisaka and A. Musashi et al.: Pharmacometrics 11(4)475-485(1976).
2) S. Furuta and S. Toyama et al.:
Medical Pharmacy .vol8.No5.1057-1063(1993)
3) J. N. A. van Balgooy and E. Roberts, Biochem.Pharmac.24
1421-1425(1975)
4) H. Joshima and M. Kashima et al.:Health Physics Instruction.
11. 97-103(1976)

Graduate School of Human Life Science, Showa Women’s University- 245 -

RIKEN Accel. Prog. Rep. 40 (2007)

Effect of carnosine on gastric secretion in rats
K. Igarashi*1, Y. Kanayama, S. Kimura*2 and S. Enomoto
Iron deficiency is the most frequently occurring

the carnosine-metal complex has been clarified recently 5).

nutritional disorder in the world. One of the main causativeThus, to investigate the effect of carnosine on thefactors of iron deficiency is the poor absorption of dietarysolubility of iron, we investigated gastric secretion iniron. Dietary iron is classified into two types, heme iron

pylorus-ligated rats administered carnosine.

Heme iron contained in red meat,

Eight-week-old male Wistar rats were purchased frompoultry and fish has a high intestinal absorption efficiency,

Japan SLC, Inc. and housed in stainless-steel cages. The

because it directly enters mucosal cells. Non-heme iron,rats were restricted food intake but they had free access tothe main form of dietary iron, should be released fromdrinking water for 18 h. The abdomen of each rat was

conjugation for absorption. Gastric secretion is necessary

opened and the pylorus was ligated under ether anesthesia.

for the optimal absorption of iron by rats, and theAfter closure, 50, 100 or 200 mg of carnosine or saline wasadministration of HCl can increase iron absorption in

immediately administered into the gut through a tube. The

and non-heme iron.

1)

However, the absorption of released ironrats were sacrificed 6 h after the carnosine administration,

is affected by the composition of other foods in the gut. The

and the gastric juice of each rat was collected and analyzed

2)

absorption rate of vegetable iron is only about 1-2 % .

for volume, acidity and pepsin activity. Acidity was

Therefore, the enhancement of non-heme iron absorption isdetermined by titrating the gastric juice against 0.1 mol/L

important for improving iron status.

NaOH to pH 7.06). Pepsin activity was determined by theachlorhydrics .

It is well established that the bioavailability of non-heme

Anson-Mirsky revised method using bovine hemoglobin as

iron from foods is enhanced by vitamin C, citric acid andin a more soluble form and prevent it from binding toa substrate5). Pepsin activity was calculated using
7.5
1
Pepsin activity=(A-B)×50××=(A-B)×75,
0.5
10
where A is the concentration of tyrosine in the sample, andinhibitors by their chelating properties3).

B is the concentration of tyrosine in the blank.

the meat factor3). Vitamin C and citric acid maintain ironOn the other

hand, red meat, poultry and fish also enhance non-heme
iron absorption.

However, the factor associated withimproving iron absorption in these foods has yet to be

Pepsin output was calculated using pepsin activity ×volume6). The statistical significance of group differences
was determined using Student’s t-test.

clarified.

The pepsin activities, pepsin outputs and volumes in the

Carnosine is a well-known neuropeptide consisting ofcontrol and carnosine-administered rats are shown in Table

alanine and histidine (β-alanyl-L-histidine), and is found1. The rats administered 50 and 200 mg of carnosine hadin millimolar concentrations in the skeletal muscle.

increased pepsin activities compared with the control rats.

Carnosinewith

The pepsin activity in the 50-mg-carnosine-administeredlipid-peroxidase

rats was significantly higher than that in the control rats.

anaturalhydroxyl-radical-scavenging

and

4)

activities .

acts

as

antioxidant

Furthermore, the pharmacological activity of*1 Department of Health and Nutrition, University of Human Arts andSciences2* Graduate School of Human Life Sciences, Showa Women’s University

However, no significant differences were observed between
the 100- and 200-mg-carnosine-administered rats and thecontrol rats, indicating that 50 mg of carnosine increases
pepsin activity.

- 246 -

RIKEN Accel. Prog. Rep. 40 (2007)

Table 1 Pepsin activities, pepsin outputs and volumes inthe volume in the 200-mg-canosine-administered rats wascontrol and carnosine-administered rats.

lower than that in the control rats, indicating that the rats
administered 50 mg of carnosine have an increased gastricjuice secretion.

Pepsine activity

Pepsine output

Volume(μg/ml/min)(trypsine μg)(ml)

These results indicate that 50 mg of carnosine increases

control1085±149

4079±1531

3.4±0.9

gastric juice volume, pepsin activity and pepsin output,

50 mg of carnosine

1913±251*

11717±1814*

5.8±1.0*

although this effect does not depend on carnosine dose. It is

100 mg of carnosine

1000±903289±514

3.3±0.3

considered that carnosine enhances iron absorption by

200 mg of carnosine

1344±243

3589±363

2.8±0.3

increasing iron solubility.

All values represent the mean±S.E. for four or five rats. *Significant differences were observed between the control

References
1) E. R. Morris: Trace Elements in Human and Animal

and carnosine-administered rats (P<0.05).

Nutrition, edited by W. Mertz (Academic Press, California,
The pepsin output in the 50-mg-carnosine-administeredrats was significantly higher than that in the control rats.
Although there were no significant differences in pepsin
output between the control rats and the 100- and 200mg-carnosine-administered rats, the pepsin outputs in the100- and 200-mg-carnosine-administered rats were lower
than that in the control rats. This indicates that 50 mg ofgastric

juice

volume

in

the

50-

mg-carnosine-administered rats was significantly higher
than

that

in

the

control

2) L. Hallberg: Ann. Rev. Nutr. 1, 123 (1981).
3) I.M. Zijp, O. Korver, and L.B. Tijburg: Crit. Rev. Food
Sci. Nutr. 40(5), 371 (2000).
4) M.A. Babizhayev, M. Seguin, J. Gueyne, R.P.
Evstigneeva, E.A. Ageyeva and G.A. Zheltukhina: Biochem.
J. 304, 509 (1994).
5) M. Seiki, S. Ueki, Y. Tanaka, M. Soeda, Y. Hori, H. Aita,

carnosine increases pepsin output.
The1987), p. 91.

rats.

The

100-

mg-carnosine-administered rats exhibited a gastric juice
volume similar to that of the control rats. On the other hand,

T. Yoneta, H. Morita, E. Tagashira and S. Okabe: Nippon
Yakurigaku Zasshi 95(5), 257 (1990).
6) I. Kanai: Kanai’s Manual of Clinical Laboratory, editedby M. Kanai (Kanahara ＆ Co., Ltd., Tokyo, 1993), p.
1320.

- 247 -

㻃 RIKEN Accel. Prog. Rep. 40 (2007)
㻃

Rapid solvent extraction of No2+ with multitrack microchips
Y. Tashiro,*1 D. Saika,*1 Y. Kitamoto,*1 K. Matsuo,*1 T. Takabe,*1 T. Kuribayashi,*1 K. Ooe,*1 T. Yoshimura,*1 W. Sato,*1
N. Takahashi,*1 A. Toyoshima,*2 H. Haba, S. Enomoto, and A. Shinohara*1

A relativistic effect markedly affects the chemical
properties of the elements at the uppermost end of theperiodic table. We have been studying the solvent
extraction behavior of actinides because the distribution
ratios of heavy actinides are related with the chemical
properties. For heavy actinide chemistry, rapid chemical
operations are required because the half-lives of heavy
actinides are very short. In previous experiments, wedeveloped a rapid solvent extraction system using a
microchip to overcome the problem, and performed theonline solvent extraction of lanthanides using this system.1)
The large specific interfacial area of the microchip makes it
possible to achieve extraction equilibrium very rapidly, but
processing rate per unit time is very low. We therefore
developed multitrack microchips comprised of two
microchips in order to increase processing rate. Here, weshow the result of the rapid solvent extraction of 255No
using the multitrack microchips.
The solvent extraction was performed for diluted
ammonia water as an aqueous phase and 0.01 M
HDEHP(di(2-ethylhexyl)phosphoric acid)-toluene solution
as an organic phase. Before the experiments, the ammonia
water and HDEHP-toluene solution were mixed and shaken
until the equilibrium was achieved. An online chemical
experiment was performed at the hot laboratory of the
RIKEN Accelerator Research Facility. A 238U target wasirradiated with 22Ne ions at an energy of 112.4
MeV/nucleon in E3b course to produce 255No by the238
U(22Ne,5n)255No reaction. During the irradiation
performed for 5 min per run, the product nuclei were
continuously transported to the hot laboratory by a gas jet
method. The transported products were dissolved in diluted
ammonia water and subsequently fed into a multitrack
microchip through a Teflon capillary. Simultaneously the
HDEHP-toluene solution was fed from the other inlet to
extract 255No from the aqueous phase. The aqueous andorganic effluents from the microchip were separately
recovered on respective tantalum plates. The effluents of
the aqueous and organic phases collected on each plate
were evaporated to dryness, and the samples were subjected
to α spectrometry. The extraction ratio D was derived fromthe equation D = Vaq㹺Aorg/Vorg㹺Aaq, where V is the volumeof the solution and A is the radioactivity of each phase. The
total chemical processing time was about 3 min.
We observed, in 34 runs, 28 events of α particle
emission from 255No, namely, 12 from the aqueous phase䟼1

Graduate School of Science, Osaka University

䟼2

Advanced Science Research Center, Japan Atomic Energy Agency

and 16 from the organic phase, as shown in Figs. 1 and 2.
This result agrees with the amount of 255No (31s6 counts)
estimated from the integrated beam currents and crosssection. The extraction ratio D was determined to be 0.8s
0.3 under the present condition. Compared with Ca2+ andSr2+, which have electronic states for the outer shellanalogous to No2+, D increases in the order Sr2+ < No2+ <Ca2+.2) This result is consistent with the ionic radii of theseelements,3) in the same manner as the result of the previous
solvent extraction of No2+ using HDEHP-octane solution.4)

Fig. 1. Alpha spectrum of 255No in aqueous phase.

Fig. 2. Alpha spectrum of 255No in organic phase.
References
1) D. Saika et al.: RIKEN Accel. Prog. Rep. 39, 111 (2005).
2) P. M. Shanbhag et al.: J. Inorg. Nucl. Chem. 41, 1033 (1979).
3) R. D. Shannon: Acta Cryst. A32, 751 (1976).
4) R.J.Silva et al.: Inorg. Chem. 13, 2235 (1974).

- 248 -

RIKEN Accel. Prog. Rep. 40 (2007)

Lack of phosphory late d histo ne H2AX in the pericentricheterochro matin
M. Izumi
In eukaryotes, DNA is packaged into nucleosomes,
which are in turn arranged in various higher-order structures
to form chromatin. The nucleosome is composed of 145
bp of DNA and histone octamers, two from each of the four
histone protein families, H2A, H2B, H3, and H4. The
histone H2A family includes three subfamilies,
H2A1-H2A2, H2AZ, and H2AX. In mammalian cells,
H2AX constitutes approximately 10% of the total H2A.
Histone H2AX becomes phosphorylated on the residue
serine 139 in cells when double-stranded breaks are
introduced into the DNA by ionizing radiation (1).
Phosphorylated H2AX directly interacts with many
components involved in DNA repair, including theMre11/Rad50/Nbs1 complex, Brca1, NFBD1, and 53BP1,
and stimulates the accumulation of these proteins aroundDNA double-strand breaks. Furthermore, phosphorylated
histone H2AX recruits cohesin and several chromatin
remodeling factors, which facilitate the homologous
recombination repair.
The
chromatin
structuresareregulatedbychromatin-associated factors and thereby contribute to theformation of domains within the genome, referred to as
euchromatin and heterochromatin.
Our previous
experiments showed that DNA double strand breaks
decreased the rate of DNA synthesis more efficiently in theheterochromatic region than in the euchromatic region (2).
However, it is unknown how repair reactions andFig. 1 Localization of phosphorylated H2AX and
PCNA in mouse FM3A cells. Cells were treated with 4mM hydroxyurea for 1 h.
The cells were then
immunostained with a rabbit anti-phosphorylated histone
H2AX antibody and a mouse anti-PCNA monoclonal
antibody and counterstained with DAPI. Arrows indicate
pericentric heterochromatin.

checkpoint responses are regulated by the chromatin
structures. It is also unknown whether H2AX proteins are
distributed on the entire genome homogeneously.
To address these questions, I focused on pericentricheterochromatin regions, which are transcriptionallyinactive and contain generally hypoacetylated histones incombination with histone H3 methylated on lysine 9.
Because pericentric heterochromatin can be easily identified
by dense DAPI staining in rodent cells, I investigatedwhether the phosphorylation of histone H2AX occurs in theheterochromatic region as well as in the euchromatic
region.
In the presence of DNA replication inhibitors, a histone
H2AX molecule that is adjacent to the DNA replication
fork is phosphorylated by ATR (ataxia telangiectasia andRad3-related) kinase. Because transcriptionally active andinactive chromatin domains generally replicate at different
times during the S-phase (3), the phosphorylation of histone
H2AX is induced in the specific chromatin regions in thepresence of DNA replication inhibitors.
The sites of DNA replication were detected by ananti-PCNA antibody as shown in figure 1. In the early S
phase, genetically active chromatin is replicated. In thisstage, several hundred PCNA foci were distributed
throughout the nucleus, except for in the nucleolus. In the
mid-S phase, PCNA was localized in the periphery of thenucleus. From the early S phase to the mid-S phase, thedistribution of phosphorylated histone H2AX was similar tothat of PCNA, and some of the foci were colocalized. In
contrast, genetically inactive chromatin is replicated in thelate S phase. In this stage, PCNA foci were observed on
the periphery of the nucleus or in the pericentricheterochromatin (indicated by arrows). Although the fociof phosphorylated histone H2AX were observed on the
periphery of the nucleus, they were not detected in theheterochromatin. These results suggest that histone H2AX
is absent from pericentric heterochromatin or that histone
H2AX is not phosphorylated in pericentric heterochromatin
efficiently.
Because homologous recombination depends on
phorphorylated histone H2AX, it is assumed that DNA
double strand breaks in pericentric heterochromatin are
repaired by non-homologous end joining. The repair
process in pericentric heterochromatin is now underinvestigation using mammalian cells irradiated with heavy
ions.
References
1) C. Thiriet and J. J. Hayes: Mol. Cell 18, 617 (2005).
2) M. Izumi et al.: RIKEN Accel. Prog. Rep. 37, 144 (2004)
3) J. Quivy et al.: EMBO J. 23, 3516 (2004).
4) A. J. McNairn and D. M. Gilbert: BioEssays 25, 647 (2003).

- 249 -

RIKEN Accel. Prog. Rep. 40 (2007)

Effect of DNA-PK inhibitors on the cellular sensitivity to heavy ionsM. Tomita,∗1 T. Tsukada, N. Fukunishi, H. Ryuto, and M. Izumi
Accelerated heavy ions with high linear energy
transfer (LET) can induce complex clustered DNA
damage involving two or more DNA double-strand
breaks (DSBs). The complexity of clustered DNA
damage shows a strong LET dependence, which makes
it a good candidate for the prime determinant of thehigher biological effectiveness of high-LET heavy ionsthan low-LET X-rays.1)
In vertebrate cells, there are two major DSB repair
pathways: non-homologous end-joining (NHEJ) andhomologous recombination (HR).2) DNA-dependent
protein kinase (DNA-PK), which is composed of a catalytic subunit (DNA-PKcs) and DNA-binding Ku70
and Ku86 heterodimer, is required for the repair of
DSBs by NHEJ.3,4) We previously reported that DNAPKcs phosphorylated on Thr2638 is recruited in thevicinity of clustered DNA damage induced by heavyions.5) In addition, the relative biological effectiveness(RBE) for cell killing in DNA-PKcs-defective cells issignificantly lower than that in normal cells.6,7) In
this study, we investigate the sensitivity to heavy ionsof human cervical cancer HeLa cells pretreated with
DNA-PK inhibitors, wortmannin and NU7026.8–10)
Figure 1 shows the clonogenic surviving fractions of
HeLa cells pretreated with 20 µM of wortmannin or
50µM of NU7026 irradiated with 250 kV X-rays (A),135 MeV/u C ions at 80 keV/µm (B), or 95 MeV/u Ar
ions at 310 keV/µm (C). The surviving fractions were
determined by a colony formation assay. The pretreatment of wortmannin or NU7026 for 1 h significantly decreased the clonogenic survival of HeLa cells irradiatedwith X-rays (Fig. 1A) as previously reported8–10) . On
the other hand, the sensitizing effect of inhibitors to
C ions (Fig. 1B) or Ar ions (Fig. 1C) was lower thanthat to X-rays. Table 1 shows the dose required for
10% cell survival (D10 ) calculated from the cell survival curve, and the RBE relative to that of X-rays.
The RBE values in the cells pretreated with inhibitors
were lower than those in the cells without inhibitors(control). Our present and previous results5–7) suggest that DNA-PK cannot efficiently react with thecomplex DSBs induced by high-LET heavy ions in thehigher-vertebrate cells.

Fig. 1. Cell survival curves for HeLa cells pretreated withor without 50 µM of NU7026 or 20 µM of wortmannin
for 1 h. Cells were irradiated with 250 kV X-rays (A),135 MeV/u C ions (80 keV/µm) (B), or 95 MeV/u Ar
ions (310 keV/µm)(C). Error bars represent standard
errors of the means (SEM), which were obtained fromtwo to three independent experiments.

References
1) D. T. Goodhead: J. Radiat. Res. 40, Suppl. 1 (1998).
2) K. K. Khanna and S. P. Jackson: Nat. Genet. 27, 247(2001).
3) G. C. M. Smith and S. P. Jackson: Genes Dev. 13, 916(1999).
4) Y. Matsumoto et al.: FEBS Lett. 478, 67 (2000).
5) M. Tomita et al.: RIKEN Accel. Prog. Rep. 38, 129(2005).
6) M. Tomita et al.: RIKEN Accel. Prog. Rep. 37, 145(2004).
7) M. Tomita et al.: RIKEN Accel. Prog. Rep. 39, 131(2006).
8) M. Tomita et al.: J. Radiat. Res. 41, 93 (2000).
9) M. Tomita et al.: Radiat. Res. 160, 467 (2003).
10) S. J. Veuger et al.: Caner Res. 63, 6008 (2003).

Table 1. D10 and RBE values
Inhibitor

D10 a (Gy)
X-raysC
Ar
Control
5.7
2.4
1.8
50 µM NU7026
1.7
0.90 0.98
20 µM wortmannin
1.3
1.2
1.2
a
The dose leading to 10% cell survival
∗1

RBE
C
Ar
2.3 3.2
1.9 1.7
1.1 1.1

Central Research Institute of Electric Power Industry- 250 -1㻃

RIKEN Accel. Prog. Rep. 40 (2007)

㻃

Heavy ion irradiation of human cultured cells: The irradiatedmedium can reduce the rate of s pontaneo usly induced mutations
F. Yatagai, Y. Umebayashi, M. Honma*1, T. Abe, and M. Iwaki
It is important to elucidate the indirect effects of ionizing
radiation at the cellular level. Here, the indirect effects
means the cellular responses induced not in the cells
directly hit by the ionizing radiation but in their neighboring
cells, generally called as “bystander effect”. The accelerated
heavy-ions are very convenient for elucidating the above
effects, because a hit or not-hit can be easily judged by theion traversal through the cell. As a beginning stage of thisline of studies, the preliminary experiments were performedby using the 135MeV/u carbon beam, as schematicallyillustrated in Fig.1.

Un-irradiatedC-ion Irradiated (2Gy)

MediumExchange

In the mutation assay1,2), the plating efficiency wasmeasured by limiting dilution methodology to determine thefraction of viable cells. The TK- mutant clones were judged
by seeding cells into 96-well micro-well plates at 4 × 104
cells per well, in RPMI medium containing 4 µg/ml
trifluorothymidine (TFT). Early TK- mutant clones (EMs)and late mutant clones (LMs) were separately selected after
two and four weeks of incubation with this selection
medium, respectively, because the radiation exposure
effects can be easily estimated by EM collection. The
results are summarized in Table1. The exchange of medium
for 2 Gy irradiated cells did not make any significant
influences on both fractions of EM and LM in TK mutation
frequency. Although the data is not shown in Table 1, this2Gy irradiation reduced the cell surviving-fraction to about
10% or less. On the other hand, the EM for the un-irradiatedcells were decreased from (1.0+0.5) X 10-6 to (0.38+0.21) X
10-6 by the medium change. However, the LM was notchanged by this procedure. In other wards, the irradiatedmedium used for the cell irradiation could reduce the rate of
spontaneous mutations induced at relatively early period.
Table 1 Measurements of TK- mutation frequencies (X10-6).
Un-irradiated Sample
Un-irradiatedmediumIncubation and Mutation Assay
Fig. 1. A schematic illustration for the irradiation of cells
and medium exchange
Human lymphoblastoid cell TK6 cells were incubated in
RPMI1640 medium supplemented with HAT to eliminate
pre-existing TK- (thymidine kinase) mutants1,2). The cells
were resuspended in fresh medium at 8 × 105 cells/ml, and
25 ml of cell suspension was dispensed into the culture
flasks (Nunc, 25 cm2). Unirradiated cells were suspended in
the same flasks at 5 × 104 cells/ml. After the C-ion
irradiation, both un-irradiated and irradiated cells were
centrifuged and resuspended in the original medium or theexchanged medium as shown in Fig. 1. The suspensions of
un-irradiated and C-ion irradiated cells were transferred to
new T75 flasks (Falcon, non-treated tissue culture) andincubated for about 60 hrs (4 doubling-time) to reach 8 ×
105 cells/ml at the end.
䟼1

National Institute of Health Sciences

Irradiated Sample(C-ion 2 Gy)

Irradiatedmedium

Un-irradiatedmediumIrradiatedmedium

EM

1.0
+0.5

EM

0.38
+0.21

EM

13.8
+2.4

EM

11.4
+4.0

LM

1.2
+0.2

LM

1.4
+0.5

LM

23.5
+1.8

LM

22.9
+4.2

Total

2.3
+0.6

Total

1.8
+0.6

Total

37.3
+1.4

Total

34.3
+7.0

Data from 3 independent experiments are shown as mean ± SD.

The bystander effect is generally believed to provide theadditional damage to the neighboring cells, for example
mutation induction. From this kind of aspect, the present
phenomenon might be classified as an adaptive response,
which is defined to reduce the toxic and mutagenic effects ofa particular stress by pre-treatment of the cells, for example,
a pre-exposure with low-dose of ionizing radiation. We are
now planning to elucidate the molecular mechanisms
underlining the new phenomenon of indirect radiation
effects.
References
1) F. Yatagai et al.: Mutat. Res. 560: 133-145 (2004).
2) Y. Umevbayashi et al.: Biol. Sci. Space 19: 237-241 (2005).

- 251 -

RIKEN Accel. Prog. Rep. 40 (2007)

Mutation induction by heavy-ion irradiation in Cyanidioschyzon merolae 10D
M. Ohnuma*1, T. Yokoyama*2, T. Inoue*2, H. Ichida, Y. Hayashi, N. Fukunishi, H. Ryuto, T. Abe, Y. Sekine*2, K. Tanaka*1
Cyanidioschyzon merolae 10D is a unicellular red alga that lives
in acidic hot springs. The C. merolae cell contains one nucleus, one
mitochondrion and one plastid, assumed to be a primitive feature ofthis eukaryotic cell. The genome sequence of the nucleus andorganelles of C. merolae have been completely determined.
Bioinformatic analyses of the genome revealed that the alga has thesimplest genome in photosynthetic eukaryotes and that many plastid
genes, which have been lost or migrated to nucleus during evolution
in higher plants, are found in the plastid genome in C. merolae.
These features suggest that C. merolae preserves characteristics ofancient origin in the plant lineage.1) To utilize genome information of
C. merolae, we are developing a transformation system for this alga.
Because few antibiotics are effective for what selection undercultivation conditions (pH 2.5, 42˚C), the UMP synthase (URA5.3,
the fusion gene of orotate phosphoribosyltransferase andorotidine-5'-phosphate decarboxylase) gene was considered theselection marker. Previously, we isolated a 5-fluoroorotic acid
(5-FOA)-resistant mutant strain, M4.2) As expected, this strain
showed uracil auxotrophy, and one base insertion mutation was
found in the URA5.3 gene. Thus, this strain was used as the host for
the transformation experiments, in which wild-type URA5.3 wasused as the selection marker.2) However, the high frequency ofreversion mutations made it difficult to discriminate truetransformants from reverted mutants. Thus, the development of ahost strain devoid of background reversion mutation is expected. In
this study, we tried to isolate a mutant with a deletion mutation in
URA5.3 induced by irradiation with heavy ions.
For the irradiation of liquid culture, C. merolae cells were grown
to about OD750=1 in MA2 medium (40 mM (NH4)2SO4, 4 mM
MgSO4·7H2O, 8 mM KH2PO4, 1 mM CaCl2·2H2O, 0.1 mM FeCl3(EDTA·2Na), twofold concentration of trace elements described in
Minoda et al. (2004), pH 2.5) containing 0.5 mg/ml uracil at 40˚Cunder illumination. They were cultured in thin tubes (outside
diameter: 5.57 mm, inside diameter: 4.29 mm) and irradiated with C(LET 23, 30, 42, 61 keV/µm), N (LET 30, 60 keV/µm) and Ne(LET 63 keV/µm) ions at a dose range of 0-200 Gy. The irradiatedcells were incubated at 37˚C in the dark for more than 10 hours. The
cells were diluted and plated onto MA2 plates containing 2 mg/ml
uracil and 0.8 mg/ml 5-FOA or spotted on a filter paper laid on theculture medium. The plates were incubated at 40˚C undercontinuous illumination. Because of the poor colony formation
efficiency of C. merolae, survival rate was calculated as follows:
After incubation at 37˚C in the dark for more than 10 hours, theirradiated cells were diluted to OD750=0.05 and incubated at 40˚Cunder illumination. After seven days, survival rate was calculated as
OD750 relative to the OD750 of the nonirradiated cells set at 100%.
The results are shown in Fig. 1. When an identical dose of C ions
was used for irradiation, survival rate decreased with an increase in
LET from 23 to 42 keV/µm. However, an increase in survival rate

*1

IMCB Univ. Tokyo*2

College of Science, Rikkyo (St. Paul’s) Univ.

was observed at LET 61 keV/µm. The survival rate of the
N-ion-irradiated cells at LET 60 keV/µm was higher than at LET 30
keV/µm. In these cases, the cells were irradiated around the stopping
point and the beams would not have had sufficient energy topenetrate tubes. When Ne ions were used for irradiation at LET 63
keV/µm, they had sufficient energy to penetrate tubes. The LD50
values of C (LET 23 keV/µm), N (LET 30 keV/µm) and Ne (LET
63 keV/µm) ions were estimated to be 50, 60 and 40 Gy,
respectively.
Eight 5-FOA-resistant strains were obtained and isolated from theplates on which cells in liquid culture were irradiated with C ions at
LET 23 keV/µm and 25 Gy, and spotted onto filter papers (total
approximately 107 cells). No 5-FOA-resistant cells arose with
irradiation at 50, 75, 100 and 200 Gy. Because the spontaneous
reversion mutation rate from M4 to the wild type wasapproxymately 2x10-7 (unpublished data), the eight 5-FOA resistantstrains obtained are expected to have been derived from heavy-ion
mutagenesis. However, sequence analyses of these 5-FOA resistantstrains revealed that the strains harbor base change or insertion
mutations in URA 5.3 (Table 1).

Fig. 1. Survival rate of C. merolae irradiated onto liquid culture.
(A) C ion, (B) N or Ne ion.
Table 1. Mutation sites of URA5.3 of 5-FOA-resistant mutants of
C. merolae obtained by C ion irradiation.
Mutation site

Mutation

No. of amino acid residues

WT

-

-

463

M4

ins-698A

Frameshift248

25 Gy-1

C1069A

Nonsense366

25 Gy-2

G962A

Nonsense320

25 Gy-3

G962A

Nonsense320

25 Gy-4

A271T

Nonsense90

25 Gy-5

ins-1034T, C1039G

Frameshift366

25 Gy-6

T437C

Miss-sense463

25 Gy-7

T437G

Miss-sense463

25 Gy-8

ins-698A

Frameshift248

ins-indicates a base was inserted at the position.

References
1) M. Matsuzaki et al.: Nature 428, 653-657 (2004).
2) A. Minoda et al.: Plant Cell Physiol. 45, 667-671 (2004).

- 252 -

RIKEN Accel. Prog. Rep. 40 (2007)

Isolation of salt-tolerant mutants of rice
induced by heav y-io n irradiatio n
Y. Hayashi,

H. Takehisa,䟼1 Y. Kazama, C. Kanba,䟼1 H. Saito, S. Ohbu, A. Tabayashi,䟼2 H. Ryuto, N. Fukunishi,
H. Tokairin, T. Sato,䟼1 and T. Abe

Heavy-ion beam irradiation is an effective mutagen forvarious plants. In our previous paper, we reported theisolation of a lesion-mimic mutant and a tall mutant of rice
by C or Ne ion irradiation1). In this report, we describe theisolation of salt-tolerant mutants of rice grown in a saline
paddy field from M2 progenies.
Rice (Oryza sativa L. cv. Nipponbare) seeds were
presoaked for 3 days in water at 28Υ without light. The
seeds that have imbibed water were then exposed to C or
Ne ions accelerated to 135MeV/nucleon by the RRC withina dose range from 10 to 160Gy. After irradiation, theseedlings were transplanted to a paddy field. M2 seeds were
harvested separately from each M1 plant approximately 6months after irradiation. The seeds of 371 M2 lines were
presoaked as described above, sown on seedbeds in April,and grown in a greenhouse for 4 weeks. The plants weretransplanted to the field at the end of May, and the paddy
field was flooded with salt water two weeks after
transplanting. The salt concentration of floodwater wasmaintained from 50 to 100mM Na+ during the experimental
period by flooding with salt water (Na+ 120mM) or fresh
water every week. Salt-tolerant mutants were observed inlate October.
We isolated four lines of salt-tolerant mutants from 371
M2 progenies examined (Table 1). All of these mutants
were obtained from populations irradiated with C ions.
Plant length was used for the evaluation of salt sensitivity.
The mutant lines 6-99, 19-59 and 19-74 grown in the saline
paddy field showed large plants height (Fig. 1). The
mutant 19-55 line did not grow so tall but was still green
when other plants were already withered up. The M2progenies of the 6-99 line as well as the 19-74 line weresegregated into salt-tolerant and salt-sensitive plants, andsalt-tolerance was fixed in M3 generation. The M2 plants of
the 19-55 line were all salt-tolerant. However the M3 plantsof the 19-59 line were still showed segregation (Table 3).

Table 1. Effect of ion-beam irradiation on the induction ofsalt-tolerant mutation in rice
Ion

㸟1

Dose

LET

(Gy)

(KeV/ȣm)No. of M2 lines

No. of salt-with salt treatment

C

20

23

82

tolerant lines
3

C

20

37. 4

77

0

C

40

23

91

1

Ne

10

60

121

0

Graduate School of Life Sciences, Tohoku University
㸟2
Mitui Nourin Co.,Ltd.

Table 2.

Height of salt-tolerant mutant plants

Control paddy field
Saline paddy field
Rate*
(cm)
(cm)
(%)
Control
94.34 ± 9.11
87.50 ± 4.94
92.7
6-99
106.96 ± 4.73
96.84 ± 9.15 102.6
19-55
88.60 ± 2.35
82.68 ± 2.61
87.6
19-59
䇭
94.50 ± 3.94
100.2
*Rate: height of plant grown in saline paddy field / control (94.34cm)

Table 3.

Frequency of salt-tolerant mutants generatedby C-ion irradiation

6-99 (M2)(M3)
19-55 (M2)19-59 (M3)19-74 (M3)

Survival rate
38/50
49/50
46/50
46/50
49/50

Sensitive
29
0
0
22
0

Tolerant
9
49
46
24
49

Fig. 1. Segregated plants from salt-tolerant mutants grownin saline paddy field

Tolerant Sensitive
6-99 (M2)Salinity is a serious problem in rice-growing countries.
Breeding for salt tolerance involving multiple genes in rice
is difficult, although the achievement of this breeding has
been highly desired. It is suggested that these mutants havemonogenic mutation in nuclear genes because of the rapid
fixation of mutant lines. They are highly expected to be newcultivars for the fields on soil salination by parental use of
these mutants. Furthermore, these mutants could be
important resources for studies of the mechanisms
controlling the salt tolerance of rice plants. Morphologicaland physiological analyses of these salt-tolerant mutants arein progress.
Control

Reference
1) T. Abe et al.: RIKEN Accel. Prog. Rep. 39, 137(2006)- 253 -

RIKEN Accel. Prog. Rep. 40 (2007)

Isolation of in florescence mu tants indu ced by heavy -ion rad ia tion
in barley ( Hordeum vulg are L.)
Eiko Hanzawa㸟1, Hiroyuki Ichida㸟2, Yoriko Hayashi, Hiromichi Ryuto, Nobuhisa Fukunishi,
Tomoko Abe, Tadashi Sato㸟1 and Atsushi Higashitani㸟1͊
vrs34), and vrs45) are related to six-rowed spikes
in barley plant. We are now attempting todetermine the locus of the two mutant lines
isolated in this study and to isolate otherreproductive mutants from the M2 pool.

To isolate reproductive mutants in barley(Hordeum vulgare L.), dry seeds of two-rowed
cultivar “Haruna Nijo” were irradiated with 30, 40
or 50 Gy of 12C6+-ion beams (135MeV/u) by Riken
Ring Cyclotron. Survival frequencies in both M1
seeds and M2 progenies did not decrease by theirradiation with less than 50 Gy of the ion beams(Table 1,2). On the other hand, the frequencies ofappearance of chlorophyll-deficient mutants(Albino) in M2 progenies increased as 0.2% at 30
Gy, 0.5% at 40 Gy and 0.6% at 50 Gy, respectively(Table 2). However, these frequencies are much
lower than that of rice seeds irradiated with 40 Gyof the 12C6+-ion beams (M2: 7.3%)1). It may be due
to larger size of chromosomes in barley plants.
We also isolated two mutant lines with six-rowed
spikes among 1,436 M2 seeds irradiated with 30 Gy.
Six-rowed mutant phenotype in both lines wasstably inherited into next generation (M3). It has
been reported that three six-rowed mutants wereselected among 5,000 M2 progenies after irradiation
with 30kR ofȚ-ray2).
The results from genetic
analyses indicate that one of them is symbolized as
vrs1 on chromosome 2H, and the rest are the same
mutant allele but different from vrs1 locus.
Lundqvist and Franckowiak have reported that atleast four recessive alleles vrs1, vrs23),

Table 1. Survival and mutational frequencies in M1 seeds.
No. ofNo. of survival
seeds
plants (%)
sowed

Dose (Gy)Albino (%)

Six-rowed
spikes (%)

024

24 (100)

0

0

30

675

667 (98.8)

0 (<0.1)

0 (<0.1)40669

621 (92.8)

1 (0.16)

0 (<0.1)50

679

664 (97.8)

1 (0.15)0 (<0.1)

Table 2. Survival and mutational frequencies in M2 progenies.
Dose (Gy)No. ofNo. of survival
seeds
plants (%)
sowedAlbino (%)

Six-rowed
spikes (%)

0110

100 (90.9)

0

0

30

1436

1268 (88.3)

3 (0.24)

2 (0.16)40

1291

1155 (89.5)

6 (0.52)0 (<0.1)50

13391246 (93.1)

7 (0.56)

0 (<0.1)

References

1) T. Abe, T. Matsuyama, S. Sekido, I. Yamaguchi,
S. Yoshida and T. Kameya: J. Radiat. Res. 43,
S157-S161 (2002)
2) T. Makino, M. Furusho and T. Fukuoka: BGN.
24, 122 (1995)
3) U. Lundqvist and J.D. Franckowiak: BGN. 26,
 263 (1997)
4) U. Lundqvist and J.D. Franckowiak: BGN. 26,
264-265 (1997)
5) U. Lundqvist and J.D. Franckowiak: BGN. 26,
159-160 (1997)*1

Graduate School of Life Sciences, Tohoku
University*2
Faculty of Horticulture, Chiba University
͊
Corresponding author:      Phone: +88-22-217-5715
     FAX: +88-22-217-5745
E-mail: ahigashi@ige.tohoku.ac.jp- 254 -

RIKEN Accel. Prog. Rep. 40 (2007)

Mutation induction by heavy-ion beam irradiation in tartary buckwheat
T. Morishita*1, Y. Miyazawa*2, H. Saito, Y. Hayashi, H. Ryuto, N. Fukunishi and T. Abe
Recently, heavy-ion beams have been regarded as a new
mutagen for plant breeding because of their high LET(linear energy transfer) and high RBE (relative biologicaleffectiveness). We previously reported the biological effectsof ion beams on buckwheat1). In this report, we describe themutation inducing effect of ion beams on tartary
buckwheat.
Dry tartary buckwheat (var: Rotundatum) seeds were
irradiated with 12C6+ (135 MeV/u), 20Ne10+ (135 MeV/u),13
N (135 MeV/u, 26.4 keV/μm), 40Ar17+ (95 MeV/u, 305
keV/μm), and 56Fe24+ (90 MeV/u, 630 keV/μm) ions. To
adjust the LET of 12C6+ and 20Ne10+-ions at the surface ofthe seeds, an absorber was placed in front of the samples.
The irradiated seeds (M1) were sown and M2 seeds were
harvested from the M1 plants. M2 seeds were sown in the
upland field in plant-to-row lines. Visible mutant traits,
such as leaf color and morphological mutations were
investigated.

＊1

National Institute of Agrobiological Sciences＊2

Grad. Sch. Life Sci., Tohoku Univ.

Table 1 shows the mutation frequencies and types ofmutants in the M2 generation. Mutation frequency increased
with an increase in dose. In particular, when irradiationdose was 100 Gy, a high mutation frequency (more than10%) was observed. Various mutants were obtained byirradiation treatments. Among the morphological mutations
observed, dwarfism was the mutation most frequently
observed. Leaf color mutants were also observed frequently.
However albino mutants were only observed for 100 Gy
carbon ions with 39 keV/μm irradiation treatment. Becausesome of these mutants were fertile, we collected M3 seeds
and will research the agronomic characteristics of themutants in the future.
Reference
1) T. Morishita et al.: RIKEN Accel. Prog. Rep. 36, 137(2003)- 255 -

RIKEN Accel. Prog. Rep. 40 (2007)

Effects of carbon-ion beam irradiation on plant growth andmutation induction in Nicotiana tabacum
H. Saito, H. Ryuto, N. Fukunishi and T. Abe
In our previous study, we successfully induced frequent
mutations in tobacco by irradiating developing embryoswith a heavy-ion beam1). However, it is difficult to apply
this method at specific stages of plant development. In
this study, therefore, we examined the effects of heavy-ion
beams on plant growth and mutation induction in seeds andin vitro leaf cultures of tobacco.
Dry seeds, imbibition seeds and in vitro leaf culturs of
tobacco (Nicotiana tabacum cv. Xanthi) were irradiatedwith 12C-ion beams (135 MeV/nucleon) at a dose ranges of
0 - 300, 10 - 20 and 0 - 20 Gy, respectively. The LET ofions corresponded to 23keV/µm. To prepare imbibition
seeds, dry seeds were incubated on 1/2MS agar medium
plates for 1 to 2 days before irradiation. For leaf cultures,intact true leaves (5-10mm in diameter) were prepared fromtwo-week-old seedlings incubated in vitro and cultured in
MS medium containing 1mg/l BA, 3% sucrose and 0.2%
gellan gum under continuous illumination for one or 14
days before irradiation.
After irradiation, dry andimbibition seeds were incubated in 1/2MS agar medium for
two weeks. On the other hand, leaf explants weretransferred to the same fresh medium to regenerateadventitious shoots. Regenerated shoots were cut fromexplants and transferred to 1/2MS agar medium for rooting.
All plantlets were grown in a green house at 25°C under a16h/8h (light/dark) illumination cycle. The frequency ofalbino plants in 20 M2 seeds of each line was measured two
weeks after sowing in 1/2MS agar medium.
Seed germination was not affected by any of theirradiation treatments tested (Table 1).
However, adecrease in the number of plants surviving after germination
was observed only in the plants from 300 Gy-irradiated dry

seeds. Although there was little difference in the growth
rates of all the plants cultivated to the seed harvest,
high-dose irradiation for each imbibition treatment
decreased the yield of M2 seeds. In the irradiation
treatments of leaf cultures, decreases in the number ofadventitious shoots regenerated and the frequency of therooting of adventitious shoots were observed with anincrease in dose (Table 2). Additionally, differences insensitivity to the C-ion beams between the one- and 14-day
precultures were observed. Although most transplanted
plants flowered, high-dose irradiation decreased the numberof plants producing seeds and the yield of seeds. In thisstudy, few M1 plants with solid morphologicalabnormalities were produced in any of the treatments.
Additionally, most M2 seeds germinated and most seedlings
developed normal true leaves. Thus, no albino plants inany of the lines (367 M2 lines) were obtained in this study.
Five M2 seedlings obtained from each irradiation treatment
were cultivated in pots, and the isolation of mutants andcharacterization of the M2 generation are in progress.
Acknowledgement
This work was supported by a grant from the Research
project for utilizing advanced technologies in agriculture,
forestry and fisheries from the Ministry of Agriculture,
Forestry and Fisheries of Japan.
References
1) T. Abe et al.: in Modification of Gene Expression andNon-Mendelian Inheritance, edited by K. Ono and F.
Takaiwa, (NIAR, 1995), p. 469.

- 256 -

RIKEN Accel. Prog. Rep. 40 (2007)

Establishment of sex identification method and e ffect o f N-ion
beam irradiatio n in dioecio us plant C arica papaya
Y. Kazama, H. Ichida, Y. Hayashi, H. Ryuto, N. Fukunishi, N. Wakita＊1, K. Yamamoto ＊1, S. Ijichi＊2 and T. Abe＊1＊2

The PSDM primer set did not produce any bands. We
conclude that the Nafp primer set is suitable for sex
identification in native papaya in Wadomari.
To ditermine the survival rate, dry papaya seeds were
exposed to N-ion beams accelerated to 135 MeV/nucleon
by the RRC within 100 to 175 Gy.
The seeds wereincubated at 70 degree of water for 15 min. One monthafter sowing on flower pots with peat moss, viable plants
were counted. The survival rate decreased with increasing
irradiation dose (Fig. 2). The LD50 of the seeds was 175
Gy. From this result, we conclude that the appropriate
irradiation dose for papaya mutagenesis is 100-125 Gy.
The mutagenesis and screening of dwarf mutants are in
progress.
This work was partly supported by a grant from
Wadomari.

Fig. 1 Sex identification by PCR using sex-specificmarkers. Nafp and GN indicate hermaphrodite-specific andsex-neutral products, respectively. M: molecular marker, 1,
2, 3, 5, and 6: females, and 4, 7, and 8: hermaphrodites.
100
Survival rate (%)

Papaya (Carica papaya L.) is a widely cultivated fruit
crop in tropical and subtropical regions worldwide. It is oneof the special products of Wadomari. Wadomari is locatedin the Okinoerabu Island, which is struck by typhoons
during the harvest time of papaya every year. A papaya tree
is so tall that it is frequently blown down by typhoons. It
is therefore desired to produce a dwarf papaya, which is
resistant to a strong wind. The aim of this study is toinduce dwarfism in papaya by heavy-ion irradiation.
Papaya is a polygamous species with three basic sex types:
female, male, and hermaphrodite. The sex in papaya isdetermined by XY-type sex chromosomes1),2). The malegenotype is XY, the female genotype, XX, and thehermaphrodite genotype, XYh, where Yh is the modified Y
chromosome. Because papaya is a fruit crop, females(XX) and hermaphrodites (XYh), which bear fruit, areprofitable. In particular, hermaphrodites (XYh) are adesirable material for mutation breeding, because they arecapable of self-pollination. However, the sex of papaya
cannot be morphologically distinguished before theflowering stage (6-9 months after the seedling satage).
The establishment of a sex-identification method in theseedling stage is required to increase the efficiency ofmutation breeding. We report here the sex-identification
method in the seedling stage and the effect of N-ion beamirradiation on the survival rate of native papaya in
Wadomari.
To establish the sex-identification method in the seedlingstage, we examined the optimum conditions of polymerase
chain reaction (PCR) with sex-specific primers. Twohermaphrodite- or male-specific primer sets, Nafp3) andPSDM4), and a sex-neutral primer set, GN3), were tested.
Seeds were harvested from a hermaphrodite fruit and grownin flower pots at 26°C until the seedling stage. Seedlings
include females and hermaphrodites. Genomic DNAs wereisolated from the seedlings and subjected to 30 cycles of
PCR amplification (94°C for 1 min, annealing temperatures
for 1 min, and 70°C for 1 min) with each primer set. The
annealing temperatures ranged from 45 to 55°C.
Amplification products were analyzed on a 1.5% agarose
gel and visualized by SYBR-Green I staining. Nafp and
GN primer sets successfully amplified their specificproducts at the annealing temperature of 45°C (Fig. 1).
The Nafp primer set of produced a single badn
corresponding to an 831-bp sex-specific fragment only inhermaphrodites, whereas the GN primer set produced asingle 600-bp band in both hermaphrodites and females.

80
60
40
20
0
0

100

125

150

175

Dose (Gy)Fig. 2 Effect of N-ion beam irradiation on survival rate ofpapaya.
References
1) S. Horovitz and H. Jimenez: Agron. Trop. 17, 323(1967).
2) Z. Liu et al.: Nature 427, 348 (2004).
3) A.S. Parasnis et al.: Mol. Breed. 6, 337 (2000).
4) N. Urasaki et al.: Theor. Appl. Genet. 104, 281 (2002).

Wadomari-Cho Agricultural Experimental Station
Mayor of Wadomari- 257 -

RIKEN Accel. Prog. Rep. 40 (2007)

Floral and sexual mutants yielded by C-ion beam irradiation on the dioecious
plant Silene latifolia
K. Nishihara,＊ Y. Kazama, A. Koizumi,＊ H. Ichida, Y. Hayashi, H. Ryuto, N. Fukunishi, S. Kawano,＊ and T. Abe
The caryophyllaceous perennial herb Silene latifolia is adioecious plant whose sex is determined genetically by thesex chromosomes. A plant with an X chromosome and a Y
chromosome has male flowers, whereas a plant with two X
chromosomes has female flowers. It is presumed that the Y
chromosome has some regions involved in the suppressionof gynoecium development, the promotion of early stamen
development, and the promotion of anther maturation1).
However, the genes responsible for sex determination havenot been identified in S. latifolia. To identify them, weplanned to produce chromosome deletion mutants,
investigate the relationship between the deletions andphenotypes, and corroborate the transmission of themutations to their progenies.
Since C-ion beam irradiation induces the local deletion ofchromosomes, this treatment can be used to develop new
cultivars in various plants. In this study, dry seeds of S.
latifolia were exposed to C-ion beams (135MeV/nucleon)
to produce floral and sexual mutants by chromosome
cleavage and fusion. To determine an appropriate
absorption dose for differential induction, the dry seeds
were irradiated with C-ion beams within a dose range of 20- 200 Gy. We counted the number of individuals thatsprouted true leaves 20 days after sowing the irradiatedseeds to plot a survival rate to dosage curve (Fig. 1). The
survival rate was 90% at 75 Gy or less but decreased withan increase in dosage from 75 Gy. Growth inhibition wasobserved in the irradiated and surviving plants. Growth

inhibition rate correlated to dosage in similarly to withsurvival rate.
By cultivating M1 generations and screening theirmorphology, we obtained six mutants that showedmorphological aberrations from the 170 individuals
irradiated at 100 and 120 Gy. Two albino mutants wereobtained. One mutant had entirely white leaves and anotherhad variegated leaves that were partially white. Of the three
numeric-aberration mutants, two had six petals (Fig. 2, a
and b) and the other mutant had six or seven carpels withnormal 5-petaled flowers, respectively (Fig. 2, c and d). A
wild-type flower has five petals and five carpels (Fig. 2, eand f). The last mutant was a bisexual-flower mutant that
had both stamens and gynoecium.
Blooming distribution showed that 10 of 54 flowers weremales and the others were the bisexual flower shown in thebisexual-flower mutant. This bisexual-flower mutant
originated from a male plant because it does not havefemale flowers except for the male and bisexual flowers.
Bisexual flowers of this mutant self-pollinate between theirown stamens and stigmas to produce seeds. The
germination percentage of these self-pollinated seeds was
25%.
We plan to screen for hermaphrodite progeny from thesegregated M2 progenies and examine the mutated regions
on the Y chromosome. We have started to irradiate C-ion
beams on 1,000 fresh dry seeds at 100 Gy and perform abroad-scale screening for more sexual mutants.

Survival (%)
100

(a)

(c)

(e)

(b)

(d)

(f)

80

60

40

20

Fig. 2. Numeric-aberration mutants produced by C-ion beamirradiation. (a) male flower with six petals. (b) female
flower with six petals. (c) female flower with seven carpels.
(d) longitudinal section of female flower with seven carpels.
(e) wild-type male flower. (f) wild-type female flower.

0
0

50

100

150

200

Dose (Gy)Fig. 1. Survival curve of dry seeds irradiated with C-ion beams in
S. latifolia.

References＊

Department of Integrated Biosciences, Graduate School of Frontier
Sciences, The University of Tokyo

1) Westergaard: Hereditas 32, 419 (1946).

- 258 -

RIKEN Accel. Prog. Rep. 40 (2007)

Effect of ion beam irradiation in Chinese chive (Allium ramosum L.)
M. Takahashi*, Y. Matsuda*, Y. Kazama, Y. Hayashi, H. Saito, H. Ryuto, N. Fukunishi, T. Abe and T. Murata*
It is difficult to improve the agronomic traits of Chinese
chive (Allium ramosum L.), by the the traditional method ofcrossing, because of its apomict nature by diprospory(parthenogenesis and chromosome doubling). We report
here the effects of subjecting Chinese chive seeds to ion
beam irradiation in order to induce mutants.
Mature seeds of two Chinese chive cultivars, ‘Wide
Green’ (for leaf use: W.G.) and‘Flower Pole’(for flower
stem use: F.P.) were irradiated by 12C6+ ions (135
MeV/nucleon, LET 22.6 keV/μm) within a dose range of
2.5 to 50 Gy. The irradiated seeds were sowed in the pots
containing commercial soil (N=2.5 g, P=11 g, K=3 g /10kg) on April 4, 2003，and cultivated under the natural
conditions．Plants were transplanted into the pots containing
new soil，in early of April of every year.
Leaf length and leaf width were measured in August,2005. Both length and width were varied in irradiated W.G..
In particular, both parameters were larger in the plants thatgrow from seeds subjected to 25 Gy irradiation than in thecontrol (Fig. 1).
Such variation may have been induced by chromosome
doubling; thus, the ploidy of the plants was estimated using
a flow cytometer (EPICS XL / XL-MCL System II). From
the results of flow cytometory, ploidy was found to have notchanged (data not shown). These results suggest thatmorphological variation is induced by ion beam irradiation.
Further estimation of the mutations will be achieved in thenext progeny derived from the irradiated generation.
Leaf width(mm)7.0control
25Gy irradiated

6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
100

125

150

175

200

225

250

275

300

325

350

375

400

Leaf length(mm)Fig.1 Morphological variation of leaves in ion-beamirradiated A.ramosum L.cv.’Wide Green’.
Variations in morphological and the number of floralorgans were observed in florets of the irradiated plants (Fig.
2).
The frequency of parthenogenesis was estimated byembryo sac analysis (Kojima and Nagato 1992a) in the
period of August to September in 2005，for the florets 4days after flowering. Abnormal ovules (swollen integument
and depauperated embryo sac: Fig. 3A and B) wereobserved in florets of irradiated plants, and the frequency ofabnormal ovule formation increased with increasing dosage(Fig. 3C). However, nonparthenogenetic plants weredetected in 4 plants. One plant each for 10Gy and 50Gy
irradiation, and two plants for 25Gy irradiation (Table 1)
were obtained. We will examine the utility of thischaracter, further.
In this study, the effect of ion beam irradiation on
Chinese chive seeds showed mutation induction in bothvegetative and sexual organs, Ion beam irradiation will be
useful for genetic magnification in this species. We will try
to cross between 4 nonparthenogenetic plants and apomict
plants to produce a hybrid seed by sexual reproduction, anddiscuss its useful as a new breeding material.

Fig. 2. Morphological variation of flower organ in ionbeam-irradiated A.ramosum L. cv.’Wide Green’. A: Floret
in control plant. B,C,D: Florets in irradiated plants. The
scale bar represents 3mm
C

Fig.3 Aberration of ovule in ion-beam-irradiatedA.ramosum L. cv. ’Flower Pole’. A:Normal ovule in nonirradiated specium. B: Abnormal ovule in irradiatedspecium. a: Integument cell. b: Embryo sac. c:Parthenogenetic embryo. The scale bar represents 200μm.
C: Effect of ion beam does on frequency of abnormal ovule
formation in A.ramosum L. cv. ’Flower Pole’. (1) Numberof ovules which has atrophy embryo sac and hypertrophic
integument cell / total number of observed ovules × 100.
Table 1 Frequency of parthenogenesis in ion beamirradiated A.ramosum L. cv. ‘Flower Pole’
Irradiationdose(Gy)

No. of observed
plantsNo. of nonparthenogenetic
plants(1)No. ofparthenogenetic
plantsPercentage ofparthenogenesis(%)

0

34

0

34

0

2.5

22

0

22

0

5

29

0

29

0

10

27

1

26

3.7

25

27

2

25

7.4

50

25

1

24

4.0

total

164

4

160

2.5

(1)：Plant ovule did not develop parthenogenic embryoSch. Agr. Kyushu Tokai U.

- 259 -

RIKEN Accel. Prog. Rep. 40 (2007)

Floral Color Mutations Derived from Heavy-Ion Beam irradiation in a Torenia Cultivar
Takeshi Kanaya*1, Kiyoshi Miyazaki*1, Kenichi Suzuki*1, Kazunari Iwaki*1, Hiroyuki Saito, Yoriko Hayashi,
Hiromichi Ryuto, Nobuhisa Fukunishi, Tomoko Abe*1
Suntory Flowers, Ltd.
differences in other characteristics, such as flowers size,
plant form, and, vigorous growth habit, from the parent
plant.
As a conclusion, it is difficult to obtain highly stable
floral color mutants of Torenia using heavy-ion beams.
However, as indicated by the present study, it is possiblethat Torenia mutants with high stability can be obtained.
For this reason, heavy-ion beams demonstrate highpotential for obtaining artificial mutants of Torenia.

Number of Developed Shoots

The heavy-ion beam is known as an effective mutagen
for various plants. Riken and Suntory Flowers, Ltd.,
have jointly developed some new ornamental varieties
of Verbena and Petunia using heavy-ion beamirradiation1). We report here a new mutant of Torenia
obtained by heavy –ion beam irradiation.
Horticultural varieties of Torenia are one of the mostimportant worldwide summer bedding plants. However,the flower color range of these varieties is limited.
Meanwhile, Miyazaki et al. (2006) reported theheavy-ion beam irradiation of Torenia2). The Torenia
hybrid ‘Summer Wave Blue’ (Suntory Flowers, Ltd.)was used as the starting material. Tissue culturematerials of leaf tissue and stem internodes without
lateral meristems were irradiated with N ions and Ne
ions. As a result, some floral color mutants including
pale blue, blue without blotches, pale pink, and pinkwere obtained. The maximum frequencies per
acclimatized plant obtained by N-ion and Ne-ion
irradiation were 1.89% for N 50Gy and 1.64% for Ne
20Gy. These mutants were maintained by cuttings.
However, some back mutations were observed on
several shoots.
In the present study, tissue culture materials of the leaf
tissue of ‘Summer Wave Blue’ were used and irradiatedwith C ions. Irradiation treatment was conducted at
dosages of 5, 10, and 20 Gy; 40 leaves were treated ateach dosage.
The number of developed shoots from the leaves isshown in Fig.1. There was no significant difference inthe number of developed shoots for different dosages.
However, some floral color mutants including light blue,
and white with pink blotches were obtained from theirradiated materials. Cuttings were made of all themutants and they were maintained. Some backmutations were observed on several shoots as well as Nions and Ne ions. However, a mutation that was whitewith pink blotches was obtained (Fig.2). This mutant
showed a high level of floral color stability. There are no

500
400
300
200
100
0
5Gy

10Gy
20Gy
C-Heavy-Ion-Beam Dosage

Fig.1. Number of shoots developed from 40 pieces ofleaves irradiated with C-ion beam.

Fig.2. Flowers of Torenia mutant.
References
1) K. Suzuki et al.: Radiation & Industries 99, P40(2003).
2) K. Miyazaki et al.: Plant Biotechnology 23,
P163-167 (2006).
- 260 -

RIKEN Accel. Prog. Rep. 40 (2007)

Induction of flower mutant by heavy-ion beam irradiation of cyclamen
M. Sugiyama,* T. Terakawa,* H. Saito, H. Ichida, Y. Hayashi, N. Fukunishi, H. Ryuto, and T. Abe
Recently, we have investigated the effect of heavy-ion beamirradiation on the cyclamen, an ornamental plant displayed in
winter, with the aim of establishing a protocol for efficiently
producing a novel mutant.1) In this study, the effect of aheavy-ion beam on the cyclamen was examined using the
tuber of this plant as a target for irradiation.
Tubers of the cyclamen (8-15 mm in diameter, cv. Hokko
mini no. 3) produced by tissue culture were placed on
hormone-free 1/3 MS medium after their leaves and roots had
been removed. Then, the tubers were irradiated with a 12C ion
beam (135 MeV/nucleon, LET 23 KeV/μm) at doses of 4, 8,
12 and 16 Gy (30 specimens/dose). The irradiated samples
were transplanted onto the aforementioned medium for plant
elongation and rooting. Three months after the irradiation, theplants were transplanted to flowerpots and were grown in agreenhouse. Ten months after the planting, the surviving rate of
the plants relative to the total number of irradiated tubers andthe mutations in flower morphology were examined.
The effects of the irradiation on the plants are shown in Table
1. The survival rate ranged from 50 to 90%. Sterile malemutants whose anthers were atrophic or deficient wereobtained at a range from 8 to 16 Gy (Figs. 1 (b), (c)). Two petal
color mutants were obtained at 12 Gy. The petals of one
mutant was reddish purple, whereas the petals of the original
was bluish purple. The petals of the other mutant exhibited a
striped pattern of white over the underlying original color (Fig.
2 (b)). All the mutated plants showed not only mutated flowers
but also normal ones, which suggests the chimeric nature ofthese mutants.
Traditionally, a new variety of cyclamen has been developed
mainly by crossbreeding, which requires many crossings andconsiderable time. Results of this report suggest that mutationinduction by heavy-ion beam irradiation is useful for changing
flower characteristics and can shorten the breeding process ofcyclamen. The sterile male mutant did not produce pollen.
Thus, the genes of such mutant never spread to the offspringthrough the pollen. Male-sterilizing a transgenic crop lowers
the risk of undesirable gene flow from the transgenic plant to
the wild type plants via pollination. The development of asterile male mutant of a transgenic cyclamen by heavy-ion
beam irradiation is in progress.
This work was supported by a grant from the Research
project for utilizing advanced technologies in agriculture,
forestry and fisheries.

anther

(a)

(b)

(c)

Fig. 1. Sterile male mutant obtained by heavy-ion beamirradiation. (a) Wild type, (b) mutant whose anther is atrophic,and (c) mutant whose anther is deficient.

(a)

(b)

Fig. 2. Petal color mutant obtained by heavy-ion beamirradiation. (a) Wild type (bluish purple) and (b) petal color
mutant (striped pattern).

References
1) M. Sugiyama et al.: RIKEN Accel. Prog. Rep. 39, 142(2006)
Table1. Number of plants surviving irradiation with heavy-ion beam and number of mutants obtained.
Dose( Ｇｙ )

Number ofplants surviving §1

Survival rate(%)

Control
27
90
4
20
67
8
26
87
12
15
50
16
19
63
§1：30 specimens were submitted for each dose
§2：Frequency of mutants (%)*Hokko Chemical Industry Co., Ltd.
- 261 -

Number of mutants
Sterile malemutants

Petal color
mutants00000
2 (13)0

1 (3.8)§22 (13)
1 (5.3)

RIKEN
Prog. Rep.
Rep.3940 (2006)(2007)RIKEN Accel.
Accel. Prog.

Proton conducting polymer
J. Sugiyama,∗1 H. Nozaki,∗1 Y. Ikedo,∗1 K. Mukai,∗1 A. Kamiya,∗1 M. Kawasumi∗1 ,T. Suzuki∗2 , and I. Watanabe∗2[Polymer, muon, diﬀusion]
1

Introduction

Among several electrolytes for fuel cells (FC), only
Naﬁon1) , perﬂuorinated sulfonic acid copolymer, iscommercially available to make an FC working at ambient temperature. Naﬁon is however ionically conductive only when it contains water, meaning a very
limited performance above 373 K, although we need
an electrolyte with high proton conductivity up to ∼423 K. In order to know information on proton conductivity without water, we have performed a µ+ SR
experiment on Naﬁon for detecting proton hopping via
muon diﬀusion.
2

reasonable to ﬁt the ZF-spectra by an exponential relaxation function3) . The ν(T −1 ) curve for the relatedmaterial CF650, in which the density of sulfonic acidis roughly twice as large as that in Naﬁon, however
exhibits a very diﬀerent behavior with that for Naﬁon
and the past result3) , for reasons currently unknown.
In order to further elucidate muon diﬀusion in polymer electrolytes, we need to continue the µ+ SR experiments systematically.
References
1) http://www.fuelcells.dupont.com/
2) K. Nishiyama et al., Physica B 326 (2003) 41.
3) J. Sugiyama et al., KEK-MSL Report 2004 (2004) 20.

Experimental

3

CORRECTED ASYMMETRY

After immersing in H2 O, Naﬁon ﬁlms with ∼180 µm
thickness were dried in vacuum at 100o C for 12 hours,
then six ﬁlms with 26 mm diameter were stacked ina sealed sample cell in an Ar-ﬁlled globe-box in Toyota CRDL, and then the cell was transferred to the
UK and was set onto the oven sample holder. Theµ+ SR experiment was carried out on the ARGUS surface muon beamline at RIKEN Muon Facility at ISISin the temperature range between 300 and 450 K.
Results

The ZF- and LF-µ+ SR spectra for dry Naﬁon are
well ﬁtted by a combination of a dynamic KuboToyabe signal and an exponential relaxation signal (seeFig. 1); the former is caused by randomly oriented 1 H
and 19 F nuclear magnetic moments, while the latter
due to the formation of F-µ+ and/or F-µ+ -F state2) .

0.3
10G
5G

0.2

0.1 Dry Nafion 117
ZF- and LF-µSR
at 300 K
00
1020
TIME (µs)

Fig. 1. ZF- and LF-µ+ SR spectra for dry Naﬁon at 300 K.
The solid lines represent the ﬁtting result using Eq. (1).

10

Nafion∆ν-1∆ or ν (10 s )

DGKT

(1)

1

6

A0 PZF (t) = AKT G(t, ∆, ν) exp(¡λKT t)+ Afast exp(¡λfast t),

0G

where A0 is the empirical maximum muon decay asymmetry, AKT and Afast are the asymmetries associatedwith the two signals. λKT , and λfast are their relaxation rates, ∆ is the static width of the local frequencies at the disordered sites, and ν is the ﬁeld ﬂuctuation
rates due to muon hopping.
The T dependence of ∆ for dry Naﬁon indicates theexistence of a thermally activated process for ν, as expected (see Fig. 2). Since ν À ∆ at high T , it is∗1∗2

Toyota Central R&D Labs., Inc.
Advanced Meson Science Laboratory, Nishina Center for
Accelerator-based Science, Riken

0.1
CF650
∆
ν

0.01

0.001

2

2.5
3
-1
1000/T (K )3.5

Fig. 2. The relationship between ∆ (ν) and T −1 for dry
Naﬁon and the related material CF650. The data wereobtained by ﬁtting of ZF- and LF-spectra using Eq. (1).

- 263 1

RIKEN Accel.
Accel. Prog.
RIKEN
Prog. Rep.
Rep.3940 (2006)(2007)

Muon diﬀusion in lithium battery materials
K. Mukai,∗1 Y. Ikedo,∗1 J. Sugiyama,∗1 T. Suzuki,∗2 I. Watanabe,∗2 K. Ariyoshi,∗3 and T. Ohuzku∗3[muon, lithium battery materials, Jahn-Teller eﬀect]6-1

ν (10 s )are no anomalies in the χ−1 (T ) curve, the ν(T ) curve
still exhibits a maximum at ∼ 270 K, and Δ decreases
with increasing T above ∼ 270 K, while both changes
are suppressed with increasing x. The weak transverse
ﬁeld (wTF-) μ+ SR measurements clearly conﬁrm theabsence of any inclusions of a phase with x=0 in thesamples with x ≥ 0.05. Therefore, the anomalies in theν(T ) and Δ(T ) curves are due to the intrinsic behaviorof the LMO samples. In other words, μ+ SR detects ashort-range cooperative JT distortion even in the samples with x=0.15, whereas no anomalies are detectedby χ and other macroscopic measurements for LMO
with x ≥ 0.05.

∗1
∗2
∗3

Toyota Central Research and Development Labs., Inc.
Muon Science Laboratory, RIKEN
Department of Applied Chemistry, Osaka City University

0.2
(a)

6

-1

Δ (10 s )

0.2
0.1

x=0
x=0.05x=0.1
x=0.15(b)

0300

A0 PZF (t) = AKT GDGKT (t, Δ, ν) exp(−λKT t), (1)H=10 kOe
FC

200

-1

where A0 is the empirical maximum muon decay asymmetry, AKT and λKT are the asymmetry and relaxation
rate of the Kubo-Toyabe signal, Δ is the static widthof the local frequencies at the disordered sites, and ν
is the ﬁeld ﬂuctuation rates.
Figure 1 shows the T dependences of ν, Δ, and χ−1
for the four LMO samples. For the sample with x=0,
as T increases from 50 K, ν decreases monotonicallyup to 100 K, then increases with an increasing slope,ﬁnally reaching a maximum at ∼270 K, and then decreases with further increase in T . The Δ(T ) curve
exhibits a sudden decrease at ∼270 K accompanying
the maximum in ν. Since the χ(T ) curve shows a small
cusp at 275 K due to the orbital ordering of Mn3+ at
the Jahn-Teller transition6) , the peak of the ν(T ) curve
and the sudden decrease in Δ are assigned to be causedby the JT transition, not by the diﬀusion of Li+ ions.
For the samples with x=0.05-0.15, although there

Li[LixMn2-x]O4
0.4 ZF- &LF-μSR00.3

χ (mol-Mn/emu)

The (Li)8a [Lix Mn2−x ]16d (O4 )32e (LMO:Fd3̄m) spinel
is extensively investigated as a positive electrode material for rechargeable lithium batteries1) . In the cubic
LMO lattice, Li+ ions are located at the both tetrahedral 8a and octahedral 16d sites, Mn ions at the
16d sites, and O2− ions at the 32e sites to form a
cubic-closed packed array. Based on the recent μSR
experiments in LMO with x ∼02,3) , the Li+ diﬀusion
is proposed to be very fast particularly above 250 K
compared with the result of 7 Li-NMR4) . Since the Li+
ions at the 16d site alter the magnetic and electrochemical properties of LMO5) , we have carried out a μSR
experiment on LMO with x=0-0.15 to clarify the interrelationship between microscopic magnetic and structural nature and x.
Powder samples of LMO with x=0, 0.05, 0.1, and0.15 were prepared from LiOH∗H2 O and MnOOH(manganite) by a conventional solid-state reaction
technique. According to an ICP-AES analysis, theLi/Mn ratios of the samples were 1.00/2.00, 1.04/1.96,
1.09/1.91, and 1.15/1.85. For the μ+ SR experiments,
powder was pressed into a disk of ∼20 mm diameter and 1 mm thickness, and subsequently placed ona silver sample holder. The μ+ SR spectra were measured in the surface muon beam line of the RIKENRAL Muon Facility at the ISIS.
The μSR spectra above 50 K of each LMO are wellﬁtted by a dynamic Kubo-Toyabe function GDGKT ;

100
0

(c)
100 200 300 400
TEMPERATURE (K)Fig. 1. Temperature dependences of (a) ﬁeld ﬂuctuation
rate (ν), (b) ﬁeld distribution width (Δ), and (c) inverse
susceptibility for powder samples of Li[Lix Mn2−x ]O4
with x=0, 0.05, 0.1, and 0.15.

References
1) G. Amatucchi and J.-M. Tarascon; J. Electrochem. Soc.
149, K31 (2002), and references cited therein.
2) C. T. Kaiser et al.; Phys. Rev. B 62, R9236 (2000).
3) M. J. Ariza et al.; J. Phys. Chem. B 107, 6003 (2003).
4) V. M. J. Verhoeven et al.; Phys. Rev. Lett. 86, 4314
(2001).
5) T. Ohzuku et al.; J. Power Sources, 68, 646 (1997).
6) J. R.-Carvajal et al.; Phys. Rev. Lett. 81, 4660 (1998).

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1

RIKEN Accel. Prog. Rep. 40 (2007)

RILAC operation
Eiji Ikezawa, Masayuki Kase, Osamu Kamigaito, Takahide Nakagawa, Naruhiko Sakamoto,
Hiroki Okuno, Naohito Inabe, Masanori Wakasugi, Nobuhisa Fukunishi,
Misaki Kobayashi-Komiyama, Masanori Kidera, Yoshihide Higurashi, Hiromichi Ryuto,
Tamaki Watanabe, Shigeo Kohara, Masaki Fujimaki, Makoto Nagase, Tadashi Kageyama,
Shigeru Yokouchi, Akira Yoneda, Toshimitsu Aihara,* Tomonori Ohki,* Hiromoto Yamauchi,*Akito Uchiyama,* Kazuyuki Oyamada,* Ryo Koyama,* Akira Goto, and Yasushige Yano

Throughout this reporting period, RILAC has been insteady operation and has supplied various ion beams invarious experiments. Table 1 shows statistics for the
RILAC operation from January 1 through December 31,
2006. In preparation for the beam commissioning of the RI
Beam Factory (RIBF), acceleration tests with RILAC andthe RIKEN Ring Cyclotron (RRC) using a 238U ion beam
were carried out in February and from May through June,
2006. The beam commissioning of RIBF started in July
2006. To achieve such purposes, 0.669 MeV/nucleon 238U,
2.675 MeV/nucleon 84Kr, and 2.653 MeV/ nucleon 27Al ion
beams accelerated by RILAC were injected intensively into
RRC. Therefore, the percentage of the beam service time
injected into RRC was approximately 43% of the total
Table 1. Statistics for RILAC operation from January 1
through December 31, 2006.

Operation time of RILAC

5886 hr

Beam service time of RILAC

4527 hr

Machine trouble

RILAC beam service time, and increased by approximately
23% compared with that one year ago. 4He, 22Ne, 40Ar, 48Ca,
58
Fe, 70Zn, and 136Xe ion beams accelerated by RILAC were
injected into RRC for the experiments. The machine
troubles encountered hardly affected the operation timeschedule throughout this reporting period.
Table 2 shows a summary of the beam service time of the
RILAC standalone allotted to each beam course (e2, e3, ande4) in the No. 1 target room of RILAC in 2006. The e2
beam course has been mainly used for the study of radiation
chemistry and accelerator mass spectrometry. The e3 and e4
beam courses have been exclusively used for researchexperiments on the heaviest elements and for various
studies in the Center for Nuclear Study (CNS), theUniversity of Tokyo, respectively. Compared with that one
year ago, the beam service time of the RILAC standalone
decreased by approximately 14% because of the beamcommissioning of RIBF.
Table 3. Operation statistics for two ion sources(18G-ECRIS and SC-ECRIS) in 2006. The
operation times using SC-ECRIS are indicated inparentheses.

0 hr

Beam service time of RILAC standalone
Beam transport to RRC

2566 hr
1961 hrTable 2. Beam service time of RILAC standalone
allocated to each beam course in No. 1 target roomof RILAC in 2006.

Beam course

Total time (hr)

%

e2

416

16.2

e3

2150

83.8

e4

0

0.0

Total

2566

100.0

Ion

Mass

He

4

1

0(

Ne

22

6

0 ( 108 )

Al

27

6

Ar

40

9, 11

Ca

48

11

404 (

0)

Fe

58

13

234 (

0)

Zn

70

16

1753 (

0)

Kr

84

18

363 (

0)

Xe

136

8, 27

U

238

14, 35
Total* Sumiju Accelerator Service Ltd.

- 265 -

Charge state

Total time (hr)

314 (

62 )
0)

50 ( 123 )0 ( 240 )
949 (

0)

4067 ( 533 )RIKEN Accel. Prog. Rep. 40 (2007)

This year, research experiments on the heaviest elements
were carried out using a gas-filled recoil isotope separator(GARIS) at the e3 beam course of RILAC for 61 days fromMarch through May and 17 days in June. A 5 MeV/nucleon
70
Zn ion beam was supplied in the experiments. The
percentage of the beam service time for the experiments
was approximately 39% of the total RILAC beam service
time, and decreased by approximately 34% compared withthat one year ago.
Table 3 shows statistics for the operation times of an 18
GHz ECR ion source (18G-ECRIS) and a superconducting
ECR ion source (SC-ECRIS) in 2006. The percentages ofthe operation time used by 18G-ECRIS and SC-ECRIS
were approximately 88% and 12% of the total ion source
operation time, respectively. The ion beams of 10 elements
were used in various experiments, beam acceleration tests,
and beam commissioning.
We carried out the following machine improvements andoverhauls during this reporting period.
(1) The vacuum control systems for the No. 5 and No. 6
RILAC cavities were replaced with new systems
using a Network Device Interface Module (N-DIM).
The interface circuits are connected to the Ethernet
and are remote-controlled by the experimental physics
and industrial control system (EPICS).
(2) A turbomolecular pump of 2400 l/s for the No. 5
RILAC cavity was replaced with a cryogenic pump of
13000 l/s. The other vacuum pumps were subjected toannual inspection.
(3) In the water cooling system, three cooling water
pumps, three air cooling fans of cooling towers, andthree heat exchangers were overhauled. The othercooling water pumps were subjected to annual
inspection.
(4) Plate power supplies as the final stages of rf systems
were subjected to annual inspection.

- 266 -

RIKEN Accel. Prog. Rep. 40 (2007)

RRC operatio n and beam line construc tion for RIBF
Masayuki Kase, Eiji Ikezawa, Tadashi Kageyama, Nobuhisa Fukunishi,
Takahide Nakagawa, Osamu Kamigaito, Hiromichi Ryuto, Hiroki Okuno, Naruhiko Sakamoto,
Masanori Kidera, Masanori Wakasugi, Misaki Kobayashi-Komiyama, Yoshihide Higurashi,
Makoto Nagase, Shigeo Kohara, Masaki Fujimaki, Shigeru Yokouchi, Yukimitsu Ohshiro*1,
Noritoshi Tsukiori*2, Ryuichi Ohta*2, Yasuteru Kotaka*2, Kiyoshi Kobayashi*2, Minoru Nishida*2,
Kunikazu Masuda*2, Seiji Fukuzawa*2, Takeshi Nakamura*2 ,Akira Goto, and Yasushige Yano
*1 The Center of Nuclear Science, the University of Tokyo.
*2 Sumiju Accelerator Service Ltd.

Table 1 shows the statistical data of the RIKEN Ring
Cyclotron (RRC) operation from Jan. to Dec. 2006.
The
total operation time for the year was about half of that in2005 and the beam service time was 40% of 2005. This
reduction was due to the following two reasons. A
three-month shutdown of RRC operation was made tomodify the beam lines of the RRC for beam delivery to new
injection lines to the RIBF. In the second half of the year,
most of the available beam time was devoted to thecommissioning of the RIBF. Thus, the regular beamservice was made only for three months from January to
March in 2006. Even for these periods, the beam time waslimited owing to a lack of electric power budget in thefiscal year of 2005.
The installation of the fixed-frequency Ring Cyclotron(fRC) in the E4 room was completed at the end of June
2006, together with the beam lines connecting RRC andfRC. That was the last construction work in the
Nishin-Memorial Building. The acceleration test of fRC
started in July using a uranium beam, with a frequency of
18.25 MHz, supplied from RRC. Developments for
improving the beam quality of RRC were performed inorder to increase the efficiency of fRC acceleration.
At the end of November 2006, the acceleration test ofIntermediate Ring Cycltoron (IRC) started after thecompletion the of the injection beam line. RRC supplied akrypton beam, with a frequency of 36.5MHz, directy to
IRC.
During the shutdown in spring, the vacuum leakage ofthe valley chamber of RRC was repaired. Long-term
irradiation of fast neutrons from the septum of electrostatic
deflection channel (EDC) in the RRC probably had caused
the hardening of the viton o-ring seal in a vacuum chamber,
triggering the crack. This leakage occurred for the first timein the 20-year-term of the RRC operation.
The beam transport line from RRC to fRC uses amajor part of the existing one in the D room. The entranceof the E4 room was shifted downstream by 10m. The
series of triplet quadrupole magnets were rearranged tomake a space for the new sixth-harmonic rebuncher. The
extraction beam line from fRC to the E1 room was newly
constructed in the D room along the south wall of the Droom, crossing twice the existing beam lines. To create
make for a dipole magnet to be installed, a large hole wasmade in the four-meter-thick concrete wall separating theRRC vault and the E1 room. The two transport lines, one
from fRC and another directly from RRC, were merged
immediately just before the stripper foil system in the E1
room.

Table 1. Operation Statistical data of RRC in 2006.
Operation time of RRC
Beam service time
RIBF commissioning
Machine troubles

2853 (5730) hr
1628 (4201) hr
496(0) hr75 (1394) hr

Nuclear physics experiments
Non-nuclear physics experiments

6535(78) %(22) %RILAC-RRC operation
AVF-RRC operation

3664(33) %(67) %

Figures in parentheses are data obtained in 2005.

- 267 -

RIKEN Accel. Prog. Rep. 40 (2007)

AV F operatio n
Masayuki Kase, Tadashi Kageyama, Yukimitsu Ohshiro*1, Nobuhisa Fukunishi,
Takahide Nakagawa, Osamu Kamigaito, Hiromichi Ryuto, Hiroki Okuno, Naruhiko Sakamoto,
Masanori Kidera, Masanori Wakasugi, Misaki Kobayashi-Komiyama, Yoshihide Higurashi,
Makoto Nagase, Shigeo Kohara, Shigeru Yokouchi,
Noritoshi Tsukiori*2, Ryuichi Ohta*2, Yasuteru Kotaka*2, Kiyoshi Kobayashi*2, Minoru Nishida*2,
Kunikazu Msuda*2, Seiji Fukuzawa*2, Takeshi Nakamura*2,
Akira Goto, and Yasushige Yano
*1
Center of Nuclear Science, the University of Tokyo.
*2
Sumiju Accelerator Service Ltd.
Table 1 shows the statistical data of the AVF
cyclotron (AVF) operation during the period from January
to December 2006 together with the data obtained during
the same period of the previous year.
The operation time,in which the AVF was used as an injector of the RRC,
decreased markedly in 2006, because the RRC operation
was suspended in spring owing to the construction of its
beam lines and because, after the construction wascompleted, the RRC was frequently operated with the
RILAC for RIBF commissioning in the second half of theyear. More than 2000 hours of AVF operation was spentfor stand-alone use in 2006. This was threefold longer
than the operation time of the previous year.
In terms of a beam course, the beam time waslargest in E7a (CRIB) at 60%, followed by C03 at 24%. In
2006, the low-energy secondary beam experiments in CRIB
were carried out very frequently, which have been managed
by CNS, the University of Tokyo.
The three types of ion source have been producing avarious ion beams since 2003.
In the case of ionsheavier than Ar, the 10 GHz ECR ion source is mainly used.
For lighter ions, both the 10 GHz ECR and the Hyper-ECR
are used alternately.
The development of production
methods for a new beam such as 7Li3+ was always carriedout in the Hyper-ECR.
The polarized ion source (PIS)
was not used at all after the shutdown of the SMART.

The upgrading of the AVF is in progress incooperation with CNS. The flattop acceleration system
was added to the AVF cavities in 2002. A ceramic part in
the rf amplifier is now improved so that high-power
operation will be possible.
The power supplies for thesector magnets were improved to increase the maximum
energy of the light ion beam at the beginning of 2005.
The maximum current of the main coil was raised from1100 A to 1200 A. The two sets of power supplies for thetrim coils were also improved. As a result, the K-value ofthe AVF increased from 70 to 78MeV. The maximum
energy of 15N5+ beam became higher than 9 MeV/nucleon,
extending the availability of RI beams by the CRIB in E7.Acceleration tests have not been performed yet, because of
the lacks of both input electric power and the capacity of
the water cooling system.
A magnetic channel in the extraction system of the
AVF was damaged in September during a tuning of ahigh-intensity beam. A serious vacuum leakage occurredin the casing of the magnetic channel. A thin stainless steel
metal melted partially owing to irradiation of a stray beam.
The second half of the Glazer lens of the injection
system of the AVF was replaced with a new one in thesummer of 2006, which had been out-of-order for many
years.

Table 1. Statistical data of AVF operation in 2005 - 2006.
Year
Total operation time
Beam tuning
Injection to RRC
AVF stand-alone
Beam course (AVF stand-alone)
E7a (CRIB)
E7b
C03

2006
3963hr2005
4858 hr

853hr (22%)
1051 hr (27%)
2059hr (52%)

1262 hr (26%)
2799 hr (58%)
715 hr (15%)

1275 hr (62%)
257 hr (12%)
527 hr (26%)

535 hr (74%)
36 hr (5%)
143 hr (20%)- 268 -

RIKEN Accel. Prog. Rep. 40 (2007)

Routine Work for Radiation Safety in Ring Cyclotron Facility
Y. Uwamino, S. Fujita, H. Sakamoto, R. Hirunuma, H. Mukai*1, A. Horigome, T. Yamaki and N. Yukawa
We report the measurement of residual radioactivity andradiation leakage at the RIKEN ring cyclotron (RRC)
facility.
Residual radioactivity in the facility was measured atvarious locations using AE133V ionization-chamber
gamma-ray survey meters from Applied Engineering, Inc.
The scheduled overhaul of the cyclotrons started 9 days
after their operation using an 40Ar beam of 63 MeV/nucleon
at RRC and a 19F beam of 6 MeV/nucleon at AVF. The dose
rates at the AVF cyclotron and RRC deflectors were foundto be 1 mSv/h and 20 mSv/h on January 6, 2006,
respectively. Figure 1 shows the variations of the dose rates
at these deflectors since 1986. The rates for 2002 and 2004
at RRC were not measured. The variations of these dose
rates have not been large since 2000.
In addition to the above measurement, the dose rate
inside the injector AVF cyclotron was measured on May 22,2006 when air leakage near the magnetic channel was
repaired. The dose rate was 90 mSv/h at the magnetic
channel.
During the period from October 1, 2005 to September 30,
2006, the dose rates were measured along the beam lines
after almost every experiment. Points a–z in Fig. 2 show theplaces where the dose rates exceeded 18 μSv/h. Table 1
summarizes the observed dose rates and gives the dates on
which the measurements were performed. The maximum
dose rate was found to be 2000 μSv/h at the RIKEN
projectile-fragment separator (RIPS) target in the beam
distribution corridor, denoted by p in Fig. 2. Whenever weobserved a high dose rate, we roped-off the area and posted
a warning sign indicating that it was dangerous to remain
for a long time at that place.

We continuously monitored the radiation leakage fromthe RRC facility using neutron and gamma-ray active area
monitors and passive monitors with a thermoluminescence
dosimeter (TLD). The passive monitor for neutrons wasdeveloped by us, and it measures the effective neutron dose.
The radiation leakages were below the detection limit of thearea monitors placed near the site boundary. We evaluatedthe radiation level at the boundary of theradiation-controlled area using an area monitor installed in
the computer room on the ground floor immediately abovea bending magnet that guides the beams from the RRC vault
to the distribution corridor, and it was approximately 6.4
μSv/y, which was much lower than the allowable dose limit(5000 μSv/y). The variation of the annual radiation leakage
measured using this area monitor for the last 8 years isshown in Fig. 3. The value increased until 2005, anddecreased in 2006 due to the shorter operation time of RRC,
which was stopped during the construction of the new fRC
beam line.

1.E+05

Fig. 2. Layout of RIKEN ring cyclotron facility as of 2006.
The measurement locations of residual radioactivity along
the beam lines are indicated by points a-z.

1.E+0312

1.E+02RRC

accumulated dose (μ Sｖ/year)

dose rate ( μ Sv/h)

1.E+04AVF

1.E+01

2006

2004

2002

2000

1998

1996

1994

1992

1990

1988

1986

1.E+00year

Japan Environment Research Corp.

8
6
4
2
0

Fig. 1. Variation of the dose rates at the RRC and AVF
deflectors since 1986.
＊1

10

1999

2000

2001

2002

2003

2004

2005

2006

year

Fig. 3. Variation of the accumulated radiation leakages atthe boundary of the radiation controlled area since 1999.
- 269 -

RIKEN Accel. Prog. Rep. 40 (2007)

The results obtained using the passive dosimeters placedaround the radiation-controlled area were below thedetection limit, which was approximately 0.2 mSv/y, andthe results obtained using them placed in the RRC facility atpoints near the entrances of E6 and E7 experimental rooms

were 4.8 mSv/y and 1.6 mSv/y, respectively. These points
are in the corridor of the 2nd basement floor, and below the
RIPS target. The legal dose limit for these positions is 50
mSv/y.

Table 1. Summary of dose rates measured along the beam lines using ionization-chamber survey meters. Detection points
a-z indicate measurement locations shown in Fig. 2.
Detection
Measured dose rate
EnergyIntensity
PeriodDate
Particlepoint(μSv/h)(MeV/u)(enA)(days)a1
90
Mar 3, '06
p
14
5800
b
1
200
Mar 3, '06
p
14
5800
c
1
130
Mar 3, '06
p
14
5800
d
11
35
Jan 4, '06
Ar-40
63
5000
5000
e
11
45
Jan 4, '06
Ar-40
63
5000
f
11
400
Jan 4, '06
Ar-40
63
3300
g
9
500
Mar 3, '06
O-18
100
3300
h
9
200
Mar 3, '06
O-18
100
3300
i
9
300
Mar 3, '06
O-18
100
5000
j
11
350
Jan 4, '06
Ar-40
63
3300
k
9
50
Mar 9, '06
O-18
100
3300
l
9
90
Mar 9, '06
O-18
100
3300
m
9
120
Mar 9, '06
O-18
100
3300
n
9
80
Mar 9, '06
O-18
100
3300
o
9
500
Mar 9, '06
O-18
100
3300
p
9
2000
Mar 9, '06
O-18
100
3300
q
9
150
Mar 9, '06
O-18
100
3300
r
9
130
Mar 9, '06
O-18
100
5000
s
11
50
Jan 4, '06
Ar-40
63
5000
t
11
50
Jan 4, '06
Ar-40
63
5000
u
11
18
Jan 4, '06
Ar-40
63
10000
v
0.5
20
Nov 4,'05
Ar-40
63.1
10000
w
0.5
150
Nov 4,'05
Ar-40
63.1
10000
x
0.5
200
Nov 4,'05
Ar-40
63.1
100
y
4.5
60
Nov 24,'05
He-4
120
2900
z
1
100
Nov 4,'05
N-14
135- 270 -

RIKEN Accel. Prog. Rep. 40 (2007)

Operation of the tande m accelerator
T. Kobayashi and K. Ogiwara
The tandem accelerator (Pelletron, 1.7MV) was
operated for a total of 113 days for experiments during
the annual reporting period from Oct.1, 2005 to Sep.30,
2006. A total of 16 days was spent for machineinspection, beam test and recovery for electric power
failure. The period for troubleshooting was only 4days for the control system and vacuum pumps whichremarkably decreased from that of previous year (18days required for repairing SF6 leakage, wear of carbon
sheaves, damage of a charge transfer chain andcontamination of quartz tube in ion source).

(b) Effect of irradiation on the state of hydrogen inmetals

The accelerated ion species in this period are H+, He+
and B+ with energies from 1.6 to 2.5 MeV summarizedin table 1.
Experimental studies on the following subjects were
performed, and are still in progress except for (3)-(b).

(3) The analysis using elastic scattering (40days)(a) Rutherford backscattering spectrometry (RBS)
analysis of polymers, carbon materials.
(b) Ion channeling RBS analysis of GaN, AlGaNand ZnO epitaxial thin films grown on Si and MgOsubstrates.
(c) Elastic recoil detection (ERD) analysis of
diamond-like carbon (DLC) thin films andion-implanted polymers for determining hydrogen
distribution.

(1) Nuclear reaction analysis (NRA) using 1H(11B,a)2areaction (57days)(a) The state of hydrogen in Nb-based and Ta-based
alloys, and V as investigated by the channeling method

Table 1
Ion
1
4

H

B

Beam current [nA]

Analysis

Operation time [days]

1.6 – 2.5

30 – 50

PIXE

16

+

1.5 – 2.3

3 – 30

RBS, ERDA

40

+

2.0

1.0 – 1.5

NRA

57

He

11

The beam conditions and the analysis techniques of the tandem accelerator

Energy [MeV]+(2) Particle-induced X-ray emission (PIXE)(16days)(a) Development and application of a highly
sensitive high-resolution in-air PIXE system forchemical state analysis(b) Trace element analysis of biological andenvironmental samples using energy dispersive
X-ray spectrometry- 271 -

V. Records (Including the contents of annual report)
Events of in Nishina Center fiscal 2006
2006
1, Apr.
Inauguration of RIKEN Nishina Center (RNC) for Accelerator-Based Science1∼2, June
The 21st RIKEN-RAL Muon Facility Program Advisory Committee
7∼9, June
RIKEN Advisory Council (RAC)
21, June
The Signing Ceremony for ‘Supplementary Agreement for Implementation of Joint Res.
between RIKEN and National Innovation Center for Plant Biotechnology, South Africa’
30, June
The 12th Meeting of the Management Steering Committee of RIKEN BNL Collaboration
30, JuneSigning Ceremony for ‘The Todai-RIKEN Joint International Program for Nuclear Physics
Research’
3∼4, Aug.
The 1st RIBF International Users Meeting
10∼11, July Establishment of JUSTIPEN (The Japan US Theory Institute for Physics with Exotic
Nuclei)25∼27 Oct. Collaboration Meeting on Experiments with the RIBF Facility
27, Sept.
The 1st Scientific Policy Committee
3, Oct.
The Emperor and Empress’s visit to RIKEN
10, Nov.
The signing ceremony for the Memorandum of Understanding on the Creation of the Council
for China-Japan Research Collaboration on Nuclear Physics, in Beijing
18, Nov.
The signing of The Agreement on Academic Exchange with Asia Pacific Center for Theoretical Physics in Pohang, Korea
22, Dec.
RIBF Nuclear Physics Collaboration Committee
28, Dec.
First successful extraction of Aluminum beam from the SRC
2007
16, Jan.
Commemorative lecture by Prof. T. D. Lee “Symmetry and Dynamical Symmetry, Commemorate the Decoration of the Order of the Rising Sun, Gold and Silver Star (KoshibaHall, Univ. of Tokyo)”
16, Jan.
A Signing Ceremony for Memorandum of Understanding for RIKEN-BNL collaboration
16, Jan.
The 14th Meeting of The Management Steering Committee of RIKEN BNL Collaboration
1, Feb.
The 1st Program Advisory Committee Meeting for Materials and Life Science
5, Feb.
The film shoot of the Hollywood movie “Jumper”
9∼10, Feb.
The 1st Program Advisory Committee Meeting for Nuclear Physics experiments
12, March
First successful extraction of Kr beam from the SRC
15, March
First successful extraction of RI beam from BigRIPS
23, March
First successful extraction of U beam from the SRC
25, March
THE RIBF Users Informal Meeting- 273 -

Accelerator Team
1. Abstract
Our aim is to commission and develop the accelerator-complex system, mainly the rf systems, of the RI Beam
Factory. We focus on further eﬃcient use of the RI Beam Factory through R&D associated with a new injector
for parallel operation of both RI beam factory experiments and the super-heavy elements experiment. Anotherobjective of our team is to carry out an upgrading project of the AVF cyclotron on the expansion of region of its
acceleration beam energies.
2. Major Research Subjects(1) Commissioning and development of the accelerator-complex system(2) R&D of a new injector for the RRC(3) Upgrading project of the AVF cyclotron
3. Summary of Research Activity(1) Commissioning and development of the accelerator system
O. Kamigaito, N. Sakamoto, S. Kohara, J. Ohnishi and A. Goto
We perform operation, maintenance and development of the RIBF accelerator system: mainly radio-frequency
acceleration system. We also perform beam commissioning of the accelerators.
(2) Development of a new injector for the RRC
O. Kamigaito, N. Sakamoto and A. Goto
We are performing design and fabrication of a new injector for the RRC in order to make the eﬃcient use of
the accelerator beam time by making it possible to simultaneously conduct both experiments using RI’s and thesuper-heavy-element search experiment. We are in charge mainly of design and development of linacs.
(3) Upgrading of the AVF cyclotron
A. GotoWe are advancing the project of modiﬁcation of the center region of the AVF cyclotron in collaboration with
CNS, Univ. of Tokyo, in order to expand the region of its available acceleration energies. We are performing orbit
simulations in detail for that purpose. We have already completed upgrade of the performance of the coil power
supplies, improvement of the radio-frequency acceleration system, etc.

Team Leader
Akira GOTO
Members
Osamu KAMIGAITO
Shigeo KOHARA
Kiyoshi OGIWARA
Jun-ichi OHNISHI
Naruhiko SAKAMOTO
Visiting Researcher
Lukas STINGELIN (JSPS Postdoctoral Fellow)
Visiting Scientists
Mitsuhiro FUKUDA (RCNP, Osaka Univ.)
Masatoshi ITO (CYRIC, Tohoku Univ.)
Yoshitaka IWASAKI (SAGA Light Source)
Satoshi KURASHIMA (JAEA, Takasaki)
Nobumasa MIYAWAKI (JAEA, Takasaki)
Hajime SAITO (SHI Accel. Serv. Ltd.)
Research Consultants
Yoshiaki CHIBA
Shoushichi MOTONAGA
Students- 274 -

Junior Research Associate
Hironori KUBOKI (Grad. Sch. of Sci., Univ. of Tokyo)
Student trainees
Takamichi AOKI (Grad. Sch. of Sci., Univ. of Tokyo)
Keisuke ITOH (Grad. Sch. Sci. Eng., Saitama Univ.)
Hiroaki MATSUBARA (Grad. Sch. Sci., Osaka Univ.)
Ryo MATSUO (Grad. Sch. of Sci., Tohoku Univ.)
Yuji TAMESHIGE (Grad. Sch. Sci., Osaka Univ.)
Tomohiro TERAZONO (Grad. Sch. of Sci., Tohoku Univ.)- 275 -

Ion Source Team
1. Abstract
Our aim is to commission 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 R&D associated witha superconducting ECR heavy-ion source for high-intensity uranium ions.
2. Major Research Subjects(1) Commissioning and development of the ECR ion sources(2) R&D of a superconducting ECR heavy-ion source for high-intensity uranium ions
3. Summary of Research Activity(1) Operation and development of ECR ion sources
T. Nakagawa, M. Kidera, Y. Higurashi, H. Haba, T. Kageyama and A. Goto
We routinely produce and supply various kinds of heavy ions such as zinc ions for the 113th-element experiment
as well as uranium ions for RIBF experiments. We also perform R&D’s to meet the requirements for stable supplyof high-intensity heavy ion beams.
(2) Development of a superconducting ECR ion source for use in production of a high-intensity uranium beam
T. Nakagawa, J. Ohnishi, M. Kidera, Y. Higurashi and A. Goto
The RIBF is required to supply uranium beams with very high intensity so as to produce RI’s. We aredeveloping an ECR ion source with high magnetic field and high microwave-frequency, since the existing ECR
ion sources have their limits in beam intensity. The coils of this ion source are designed to be superconducting
for the production of high magnetic field.

Team Leader
Akira GOTO
Members
Hiromitsu HABA
Tadashi KAGEYAMA
Takahide NAKAGAWA
Special Postdoctoral Researcher
Yoshihide HIGURASHI
Contract Researcher
Masanori KIDERA
Visiting Scientists
Takehiro MATSUSE (Fac. Text. Sci. Technol., Shinshu Univ.)
Ryouichi WADA (Texas A&M Univ., USA)
Student Trainee
Hiroyuki HIGASHIJIMA (Grad. Sch. Sci., Rikkyo Univ.)- 276 -

RILAC Team
1. Abstract
The operation and maintenace of the RIKEN Heavy-ion Linac (RILAC) have been cariied out. The maintenaceof these devices is important to keep the log-term stablitiy of RILAC beams.
2. Major Research Subjects(1) The long term stability of the RILAC operation.
(2) Improvement of eﬃciency of the RILAC operation.
3. Summary of Research Activity
RIKEN Heavy-ion Linac (RILAC) is a frequency-tunable linac. The RILAC is composed of a Heavy-ion ECR
ion source, RFQ linac, six main cavities, and six energy booster cavities. Thousands hours are spent in a year fordelivering many kinds of heavy-ion beams to various experiments.
The RILAC has two operation modes: the stand-alone operation delivering low-energy beams directly toexperiments and the injection mode operation supplying beams into the RIKEN Ring Cyclotron (RRC). In theﬁrst mode, the RILAC supplyies very important beam to the nuclear physics experiment of “the research of superheavy elements”. In the second mode, RILAC plays very important role as upstream end of the RIBF accelerators.
The maintenance is very important in order to keep the high quality performance of the RILAC. Improvements
are always carried out for the purpose of more eﬃcient operation.

Team Leader
Masayuki KASE
Member
Eiji IKEZAWA
Research Consultants
Toshiya CHIBA
Masatake HEMMI
Yoshitoshi MIYAZAWA- 277 -

Cyclotron Team
1. Abstract
We are carryng out the operation and maintenance of five cyclotorons in RIKEN (AVF cyclotron, Riken Ring
cyclotoron: RRC, fRC, IRC, and super-conducting cyclotron: SRC). We are trying to deliver stably a high-energy
and high intensity beam to experiments.
2. Major Research Subjects(1) Operation technology of cyclotrons.
(2) Maintenance of cyclotrons.
(3) Maintenance of super-conducting cyclotron.
3. Summary of Research Activity
We are carryng out the operation and maintenance of five cyclotorons in RIKEN (AVF cyclotron, Riken Ring
cyclotoron: RRC, fRC, IRC, and super-conducting cyclotron: SRC). We are trying to deliver stably a high-energy
and high intensity beam to experiments. Detailed research subjects are the following,
Operation technology of cyclotrons.
Maintenance of cyclotrons.
Maintenance of superconducting ring cyclotron..

Team Leader
Masayuki KASE
Members
Naohito INABE
Keiko KUMAGAI
Makoto NAGASE
Hiroki OKUNO
Contract Technical Scientists
Tadashi FUJINAWA
Shigeru YOKOUCHI
Visiting Scientists
Masahiko HAYASHI (JAXA)
Naomi IKEDA (JAXA)
Chihiro KAMEZAWA (JAXA)
Satoshi KUBOYAMA (JAXA)
Masahiko MIDORIKAWA (JAXA)
Hideharu OHIRA (JAXA)
Hiromitsu OOTOMO (JAXA)
Yohei SATOH (JAXA)
Osamu SHIMADA (JAXA)
Hiroyuki SHINDO (JAXA)- 278 -

Beam Technology Team
1. Abstract
In order to realize the eﬃcient acceleration in RIBF accelerators, the operation is being improved by doing
varioous computer symulations. For this purpose, related technology (beam diagnosys, computer control, andcharge stripper) was developed.
2. Major Research Subjects(1) Improvement on the beam transmission along the multi-stage accelerator system.
(2) Development of beam diagnosis.
(3) Development of computer control.
(4) Development of charge stripper for high intensity heavy ion beam.
3. Summary of Research Activity(1) Development of the beam diagnostic technology.
(2) Development of the charge-stripping foil.
(3) Development of the computer control system of accelerator.
(4) Investigation of beam behavior in accelerators.

Team Leader
Masayuki KASE
Members
Masaki FUJIMAKI
Nobuhisa FUKUNISHI
Sachiko ITOTamaki WATANABE
Contract Researcher
Hiromichi RYUTO
Contract Technical Scientist
Misaki KOBAYASHI-KOMIYAMA
Visiting Scientists
Masanori KOSHIMIZU (Grad. Sch. Eng., Tohoku Univ.)
Hideo MIKAMI (SHI Accel. Serv. Ltd.)
Dung NGUYEN (INST, Vietnam)
Research Consultants
Kazuie KIMURA
Mutsuko SASAKI- 279 -

Cryogenic Technology Team
1. Abstract
We are operating the helium cryogenic system in the south area of RIKEN Wako campus and delivering theliquid helium to users in RIKEN.
2. Major Research Subjects(1) The high eﬃciency of the liquid herium production cycle.
(2) Optimization of the large-scaled superconductinf cyclotron.
3. Summary of Research Activity
We are operating the herium cryogenic system located in the south area of Wako campass of RIKEN. We areproducing liquid helium and supplying them to RIKEN inside users. For the purpose of eﬃcient operation, weare trying to collect the gas after the use of liquid helium.

Team Leader
Masayuki KASE
Members
Kumio IKEGAMI
Masato NAKAMURA
Technical Staﬀ-I
Hiroo HASEBE
Takeshi MAIE
Part-time Staﬀ
Kazushiro NAKANO
Research Consultant
Ken-ici KATO

- 280 -

Heavy Ion Nuclear Physics Laboratory
1. Abstract
With fast RI beams provided by the RIBF cyclotron complex, we study exotic behavior of nuclei far fromthe stability valley, explosive nuclear burning in high-temperature and high-density environment in stars andearly universe, and nuclear reactions related to solar neutrino production. For that purpose, we develop various
experimental methods based on intermediate-energy inelastic scattering including Coulomb excitation, Coulomb
dissociation, transfer- and fragmentation-reactions coupled with gamma-ray and particle-decay measurements.
We perform also study of the three-nucleon forces by precise measurements of elastic scattering and breakup
reactions of few-nucleon systems, and development of new technics including new laser-spectroscopy for exotic
nuclei. Developments of radiation detectors such as semiconductor detectors and scintillation detectors, dataprocessing methods, and construction of experimental equipment, together with theoretical studies on nuclear
structure and nuclear reaction, are also made.
2. Major Reserch Subjects(1) Spectroscopy of unstable nuclei with direct reactions(2) Development of radiation detector systems with high precision and high eﬃciency(3) Study of astrophysical nuclear reactions with fast beams of unstable nuclei(4) Development of laser spectroscopy for unstable nuclei(5) Theoretical studies on nuclear structure and nuclear reactions
3. Summary of Research Activity(1) Spectroscopy of unstable nuclei by direct reactions associated with γ-ray measurements(i) Spectroscopy of neutron-rich C isotopes
Proton inelastic scattering on 17,19 C was studied. Two transitions were observed in both nuclei indicating
existing of two bound excited states in 17,19 C nuclei in agreement with certain shell-model predictions. Spinassignments to these excited states were tentatively made. From the analysis of the excitation cross sections, 17 C
was found to be strongly deformed.
(ii) Proton and neutron collectivity in neutron-rich light nuclei
Studies of proton (or deuteron) inelastic scattering on 17 B, 16 C, 22 O, 28,30 Ne, 32,34,36 Mg, and 34 Si were performed with γ-ray spectroscopy technique. Matter deformation parameters β2 for the lowest excited states were
determined from the inelastic scattering cross sections. Together with their B(E2) values, neutron and proton
multipole matrix elements (Mn , Mp ) were deduced separately. The Mn value for the 2+ excitation of 16 C is muchlarger than the Mp value, supporting the picture of neutron-proton decoupling for the 2+ excitation of 16 C drawn
by earlier results of the lifetime measurement and 208 Pb+16 C inelastic scattering experiment. On the other hand,
the Mn values for 17 B and 28 Ne are much smaller than the corresponding Mp values, while Mn and Mp takesimilar values for 22 O, 32,34 Mg and 34 Si.
(iii) Spectroscopy of neutron-rich medium-mass nuclei
Proton inelastic scattering experiments were performed for 60,62 Cr and 58 Ti. Measurements of coincident γ-rays
deduced the locations of their ﬁrst 2+ states and the matter deformation parameters.
(2) Spectroscopy of unbound states of unstable nuclei by breakup and transfer reactions(i) Invariant mass spectroscopy of nuclei in the vicinity of the neutron drip line.
(a) Strong E1 transitions at low excitation energies (soft E1 excitation) were observed for 11 Li by the new
Coulomb breakup experiment. The good statistics allow for precise analysis for the two-neutron correlation in
the “Borrmean” nucleus 11 Li.
(b) Inelastic scattering, one-neutron knockout, and charge exchange reactions of 14 Be were measured for protonand 12 C targets. The transition to the ﬁrst 2+ state of 14 Be at Ex = 1.55 MeV was measured, which showedsmaller deformation lengths compared to 12 Be. The invariant mass spectrum of 13 Be in the one-neutron knockout
channel showed two peaks. The higher energy peak around Ex = 2 MeV was found to have a d-wave property.
(c) Two resonant states were found in the invariant mass spectrum for 23 O produced by the (d,p) reaction in
inverse kinematics. Their locations imply disappearance of the N = 20 shell gap.
(d) Invariant mass spectra were obtained for 6 He, 17 C, and 19 C by the breakup and proton inelastic scattering
in inverse kinematics. New peaks were found for the neutron-rich carbon isotopes.
(e) Precise measurements of E1 transitions were performed for 6 He and 8 He by the Coulomb breakup.
(ii) Invariant mass spectroscopy of proton-rich nuclei
Coulomb dissociation of the proton-rich nuclei 23 Al, 27 P on 208 Pb was measured. Relative energy spectra for- 281 -

22

Mg+p, 26 Si+p were obtained. The extracted cross sections provide information useful for the astrophysicalnetwork calculation on the nucleosynthesis in novae.
(iii) Missing mass spectroscopy of very neutron-rich light nuclei
Search for extremely neutron-rich systems was performed by using the missing mass method in the 2 H+8 He
collision. The reaction channels d(8 He,3 He)7 H, d(8 He,4 He)6 H, and d(8 He,6 Li)4n were of major interest. The
reference peak in the d(8 He,t)7 Heg.s. channel was clearly observed.
(3) Nuclear reaction study using the high-resolution spectrograph SMART.
(i) Clear signatures of three-nucleon-force (3NF) eﬀects are observed in the cross section minima of deuteronproton elastic scattering at an intermediate energy (E/A = 135 MeV). To assess further three-nucleon-force eﬀects,
we have extended the measurement to the deuteron-proton breakup reactions. The measurements were focusedon the polarization transfer coeﬃcients and all deuteron analyzing powers for the speciﬁc coplanar conﬁgurations,where large 3NF eﬀects are theoretically predicated. We have found a model dependence of 3NFs in a polarizationtransfer coeﬃcient.
(ii) Many experiments have been performed to test experimentally the Bell’s inequality. However, tests using
hadron systems are limited. We tested Bell’s inequality in the proton-neutron system by measuring the spincorrelation between the proton-neutron pair in 1 S0 state produced by the 2 H(d,pn)pn reaction. The proton
polarization was measured by EPOL located at the second focal plane of the magnetic spectrograph SMART.
The neutron polarization was analyzed by a newly constructed neutron polarimeter SMARTNPOL.
(4) Laser spectroscopy of RI atoms in super ﬂuid helium
We are developing a new laser spectroscopy technique for RI atoms trapped in super ﬂuid helium. We havesuccessfully measured hyper ﬁne coupling constants of 133 Cs and 85,87 Rb atoms in super ﬂuid helium with lasermicrowave double resonance method for the ﬁrst time. The accuracy of the measurement is suﬃcient to reveal
anomalous feature of helium as a host matrix as well as to determine nuclear moments of isotopes whose moments
are unknown(5) SCRIT (Self-Conﬁning RI Target)
We have been performing feasibility studies of the SCRIT concept using a prototype installed at an existing
electron ring, KSR, of Kyoto, since 2004. We have observed elastically scattered electrons from Cs ions trappedby circulating electron beam. The luminosity was determined to be 2 × 1025 /cm2 /s at the electron beam currentof 50 mA. The number of trapped Cs ions was estimated to be an order of 106 .
(6) Development of experimental devices for RIBF
(i) DALI2
DALI2, a NaI(Tl) array, for in-beam γ-ray spectroscopy has been constructed. Several experiments with fast
RI beams (β = v/c = 0.3) were performed at RIPS. For the use of DALI2 with faster RI beams (β = 0.6) at
RIBF, upgraded detector conﬁguration is being considered.
(ii) SAMURAISAMURAI (Superconducting Analyzer for Multiparticle from Radio Isotope Beams) is a large acceptancemulti-particle spectrometer we proposed to construct at RIBF. The main part of SAMURAI is a large-gap
superconducting magnet with 7 Tm of bending power. SAMURAI enables momentum analysis of heavy projectile fragments and projectile-rapidity protons with large angular and momentum acceptance. SAMURAI also
aﬀords projectile-rapidity neutron measurements with large angular acceptance in coincidence with heavy projectile fragments. In this ﬁscal year, the detailed designing of the SAMURAI magnet was started. Through theinformal information exchange with major magnet companies in Japan, the speciﬁcation documents with as good
performance as possible are being prepared.
(iii) Data acquisition system for RIBF
We have been developing a data acquisition system in a network-distributed structure with event-builders.
(iv) Autonomic detector system with UBIQUITOUS concept
We have developed the UBIQUITOUS detector system consisting of a unit for the autonomic digital signal
processing and its sub-unit implementing a ﬂush analog-to-digital converters.
(7) Nuclear theory
Theoretical works are also promoted for the following subjects in strong cooperation with experimental approaches: Cluster Aspects of Nuclear Physics/ Nuclear matter density distributions and nuclear radii/ Nuclear
structure studies using nuclear reactions / Collective excitation modes in unstable nuclei/ Astronuclear Physics/
Eﬀects of the tensor force to nuclear structure/ Self-consistent studies of quantal and thermal correlations in ﬁnite
nuclei.

- 282 -

Head
Tohru MOTOBAYASHIMembers
Nori AOI
Akihisa KOHAMA
Yukari MATSUO
Toshimi SUDA
Ken-ichiro YONEDA
Special Postdoctoral Researchers
Hidetada BABA
Yasuro FUNAKI
Takeshi FURUKAWA
Shoko KANNOTakuma MATSUMOTO
Satoshi TAKEUCHI
Kazunari YAMADA
Contract Researchers
Shawn BISHOP
Nguyen Dinh DANG
Kimiko SEKIGUCHI
Meiko UESAKA
Mitsutaka YAMAGUCHI
Asia Program Associates
Nguyen Quang HUNG
T. Khai NGUYEN
Shuo WANG
Senior Visiting Scientists
Hisashi HORIUCHI (Grad. Sch. of Sci., Kyoto Univ.)
Takaharu OTSUKA (Grad. Sch. of Sci., Univ. of Tokyo,)
Hideyuki SAKAI (Grad. Sch. of Sci., Univ. of Tokyo)
Hiroyuki SAKURAGI (Grad. Sch. of Sci., Osaka City Univ.,)
Visiting Scientists
Yasuhisa ABE (RCNP, Osaka Univ.)
Yasuo AOKI (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba,)
Shigeyoshi AOYAMA (Niigata Univ. Integrated Information Processing Center)
Ichiro ARAI (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba,)
Yoshihiro ARITOMO (Flerov Lab. Nucl. Reactions, JINR, Russia)
Daniel BAMMERER (Tech. Univ. Berlin Inst., Germany)
Daniel BAZIN (MSU, NSCL, USA)
Didier BEAUMEL (Paris-XI Univ., France)
Fa BECK (Strasbourg Nucl. Inst., France)
Carlos BERTULANI (Univ. Arizona, USA)
Yorick BLOMENFELD (Paris-XI Univ., France)
Richard BOYD (Dept. of Phys., Ohio State Univ., USA)BO CEDERWALL (Royal Insti. Tech., Sweden)
Alan CHEN (McMaster Univ., Canada)
Silvio CHERUBINI (Catania Univ., Italy)
Tien Khoa DAO (Inst. Nucl. Sci. Tech., Center for Basic Res. Computation)
Mahananda DASGUPTA (Bompay Univ., India)
Zsolt DOMBRADI (ATOMKI, Hungary)
Zoltan ELEKES (ATOMKI, Hungary)Henning ESBENSE (Argonne Nat. Lab., USA)
Michael FAMIANO (MSU, NSCL, USA)
Hubert FLOCARD (Orsay Nucl. Inst., France)
Yoshihide FUCHI (KEK)- 283 -

Shinichiro FUJII (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Yoshitaka FUJITA (Grad. Sch. of Sci., Osaka Univ.)
Tomonori FUKUCHI (Fac. of Sci., Rikkyo Univ.)
Mitsunori FUKUDA (Sch. of Sci., Osaka Univ.)
Zsolt FULOP (ATOMKI, Hungary)
Ken-Ichi FUSHIMI (Fac. of Integrated Arts and Sci., Univ. of Tokushima)
Tomoko GOMI (Natl. Inst. Radiol. Sci.)
Valdir GUIMRAES (Sao Paulo Univ. Brazil)
Kevin Insik HAHN (Ewaha Womans Univ., Korea)
Hideki HAMAGAKI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Ikuko HAMAMOTO (Lund Univ., Sweden)
Jun HASEGAWA (Tokyo Inst. of Tech., Res. Lab. for Nucl. Reactors)
Jianjun HE (Edinberg Univ.)
David HINDE (Australia Nat. Univ., Australia)
Satoru HIRENZAKI (Fac. of Sci., Nara Women’s Univ.)
Michio HONMA (Univ. Aizu)
Takatoshi HORIBATA (Fac. of Software and Information Tech., Aomori Univ.)
Akos HORVATH (Eotvos Lorand Univ., Hungary)
Munetake ICHIMURA (Fac. of Computer and Information Sci., Hosei Univ.)
Eiji IDEGUCHI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Kazuo IEKI (Fac. of Sci., Rikkyo Univ.,)
Kei IIDA (Kochi Univ. of Tech., Physical Sci.)
Nobuaki IMAI (Inst. of Particle and Nucl. Studies, KEK)
Astrid IMIG (Univ. of North Carolina, USA)
Tetsuro ISHII (JAEA)
Shigeru ISHIMOTO (Inst. of Particle and Nucl. Studies, KEK)
Naoyuki ITAGAKI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Akira IWAMOTO (JAEA)
Naohito IWASA (Dept. of Phys., Tohoku Univ.)
Hironori IWASAKI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Takuji IZUMIKAWA (Niigata Univ. RI Center)
Gai JANOS (Hungarian Academy Sci., Inst. Nucl. Res., Hungary)
Toshitaka KAJINO (National Astronomical Observatory of Japan)
Nasser KALANTAR (Univ. Groningen, The Netherlands)
Gabor KALINKA (Hungarian Academy Sci., Inst. Nucl. Res., Hungary)
Yoshiko KANADA-EN’YO (Kyoto Univ., Yukawa Inst. for Theoretical Phys.)
Seigo KATO (Fac. of Sci., Yamagata Univ.)
Kiyoshi KATO (Fac. of Sci., Dept. of Phys., Nonlinear Phys., Hokkaido Univ.,)
Takahiro KAWABATA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Takeshi KIKUCHI (Fac. of Eng., Utsunomiya Univ.)
Jongchan KIM (Seoul National Univ., Korea)
Masaaki KIMURA (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba,)
Kikuo KIMURA (Nagasaki Inst. of Applied Sci.)
Adam KISS (Eotvos Lorand Univ., Hungary)Takeshi KOIKE (Dept. of Phys., Tohoku Univ.)
Tetsuro KOMATSUBARA (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba,)
Alexe KORSHENINNIKOV (Inst. Generall & Nucl. Phys., Kurchatov Inst., Russia)
Evgueni KOUZMINE (Russian Res. Center, Kurchatov Inst., Russia)
Shigeru KUBONO (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Kazuyoshi KURITA (Fac. of Sci., Rikkyo Univ.,)
Chie KUROKAWA (Meme Media Lab., Hokkaido Univ.,)
Marco LA COGRATA (Catania Univ., Italy)
Karin LAGERGREN (Royal Insti. Tech., Sweden)
Khiem LE (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Chen LI (Peking Univ., China)
Weiping LIU (China Inst. Atomic Energy, China)
Minliang LIU (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Jingbin LU (Fac. of Sci., Kyusyu Univ.,)
William LYNCH (MSU, NSCL, USA)
Yukie MAEDA (CNS, Grad. Sch. Sci., Univ. of Tokyo)- 284 -

Kazushige MAEDA (Dept. of Phys., Tohoku Univ.)
Kensaku MATSUTA (Sch. of Sci., Osaka Univ.)
Kenichi MATSUYANAGI (Fac. of Sci., Kyoto Univ.,)
Jie MENG (Sch. of Phys., Peking Univ., China)
Alberto MENGONI (Univ. of Tokyo)
Johannes MESSCHENDOR (Univ. of Groningen, Netherlands)
Yasuo MIAKE (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba)
Shin’ichiro MICHIMASA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Mototsugu MIHARA (Grad. Sch. of Sci., Osaka Univ.)
Toshiyuki MINEMURA (Inst. of Particle and Nucl. Studies, KEK)
Shiro MITARAI (Fac. of Sci., Kyusyu Univ.,)
Wolfgang MITTIG (GANIL, France)
Takashi MIYACHI (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
Hiroari MIYATAKE (Inst. of Particle and Nucl. Studies, KEK)
Yutaka MIZOI (Osaka Elec.-Commun. Univ.)
Takahiro MIZUSAKI (Sensyu Univ.)
Peter MOLLER (Los Alamos Nat. Lab., USA)
Sadao MOMOTA (Kochi Univ. of Tech., Intelligent Mechanical Systems Eng.)
Tsuneyasu MORIKAWA (Fac. of Sci., Kyusyu Univ.,)
Ben MOTTELSON (Copenhagen NORDITA, Denmark)Hiroyuki MURAKAMI (Fac. of Sci., Rikkyo Univ.,)
Takayuki MYO (Theoretical Nucl. Phys., RCNP, Osaka Univ.)
Yasuki NAGAI (RCNP, Osaka Univ.)
Takeshi NAGATA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Takashi NAKAMURA (Tokyo Inst. of Tech., Particle-, Nucl.-, and Astro-Phys.)
Kosuke NAKANISHI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Takashi NAKATSUKASA (Univ. of Tsukuba)
Shintaro NAKAYAMA (Fac. of Integrated Arts and Sci., Univ. of Tokushima)
Evgueni NIKOLSKI (Russian Res. Center, Kurchatov Inst., Russia)
Masahiro NOTANI (Argonne Nat. Lab., USA)
Atsuko ODAHARA (Grad. Sch. of Sci., Osaka Univ.)
Kazuyuki OGATA (Fac. of Sci., Kyusyu Univ.,)
Alexey OGLOBLIN (Russian Res. Center, Kurchatov Inst., Russia)
Yukimitsu OHSHIRO (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Takashi OHTSUBO (Dept. of Phys., Niigata Univ.)
Kazutaka OHZEKI (Tohoku Univ. CYRIC, Detector Group)
Hiroyuki OKAMURA (CYRIC, Tohoku Univ.)
Shinsuke OTA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Masahisa OTA (Dept. of Phys., Konan Univ.)
Kazuhiro OYAMATSU (Fac. of Studies on Contemporary Society, Aichi Shukutoku Univ.,)
Kyoichiro OZAWA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Jonathan PEARSON (McMaster Univ., Canada)
P. A. Atoy PERERA (Univ. Kelaniya, Sri Lanka)
Gianluca PIZZONE (Catania Univ., Italy)
Chilakamarri RANGACHARYULU (Univ. Saskatchewan, Canada)
Stefano ROMANO (Catania Univ., Italy)
Hiroyuki SAGAWA (The Univ. of Aizu, Center for Mathematical Sci.)
Akito SAITO (Dept. Phys., Grad. Sch. Sci., Univ. of Tokyo)
Takao SAKAGUCHI (BNL, USA)
Harutaka SAKAGUCHI (Dept. of Applied Phys., Fac. of Eng., Univ. of Miyazaki)
Mitsuo SAKAI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Badawy SARHAN (Cairo Univ., Egypt)
Kimikazu SASA (Univ. of Tsukuba)
Yoshiteru SATOU (Grad. Sch. of Sci., Tokyo Inst. of Tech.)
Ryoichi SEKI (California State Univ., Northridge, USA)
Noritaka SHIMIZU (Grad. Sch. of Sci., Univ. of Tokyo)
Youhei SHIMIZU (Theoretical Nucl. Phys., RCNP, Osaka Univ.)
Yoshifumi SHIMIZU (Fac. of Sci., Kyusyu Univ.,)
Cosimo SIGNORINI (Univ. of Padova, INFN, Italy)
Dorottya SOHLER (ATOMKI, Hungary)- 285 -

Andreas STOLZ (MSU, NSCL, USA)
Kenji SUDA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Kazuko SUGAWARA-TANABE (Otuma Women’s Univ.)
Satoru SUGIMOTO (Grad. Sch. of Sci., Kyoto Univ.)
Kohsuke SUMIYOSHI (Div. of Liberal Arts, Phys. Group, Numazu College of Tech.)
Yang SUN (Univ. of Notre Dame, USA)
Toshio SUZUKI (Univ. of Fukui, Fac. of Enginerring)Takeshi SUZUKI (Faculity of Eng., Saitama Univ.)
Shoji SUZUKI (Inst. of Particle and Nucl. Studies, KEK)
Akihiro SUZUKI (Suzuki Corp.)
Nobuyuki SUZUKI (Dept. of Phys., Niigata Univ.)
Yoshihiro TAGISHI (Univ. of Tsukuba, Inst. of Phys.,)
Naoki TAJIMA (Univ. of Fukui, Fac. of Enginerring)
Tadayuki TAKAHASHI (JAXA)
Yutaka TAKAHASHI (Sch. of Sci., Osaka Univ.)
Masatoshi TAKANO (Waseda Univ. RISE)
Masaaki TAKASHINA (Kyoto Univ., Yukawa Inst. for Theoretical Phys.)
Noboru TAKIGAWA (Fac. of Sci., Tohoku Univ.,)
Tadaaki TAMAE (Lab. of Nucl. Sci., Dept. of Phys., Tohoku Univ.)
Atsushi TAMII (RCNP, Osaka Univ.)
Masahiko TANAKA (KEK)
Gurgen TER-AKOPYAN (JINR. Flerov Lab. of Nucl. Reaction, Russia)
Takashi TERANISHI (Kyusyu Univ.)
Jun TERASAKI (Peking Univ., Dept. of Phys., China)
Mariko TERASAWA (Hogh Sch. of NHK GAKUEN)
Renju THOMAS (Australia Nat. Univ., Australia)
Wendong TIAN (Shanghai Inst. Applied Phys., China)
Manyee TSANG (MSU, NSCL, USA)
Tomohiro UESAKA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Yutaka UTSUNO (JAEA)Peter VON BRENTANO (Koln Univ., Germany)
Takahiro WADA (Fac. of Sci. and Eng., Konan Univ.)
Yasuo WAKABAYASHI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Tomotsugu WAKASA (Fac. of Sci., Kyusyu Univ.,)
Takashi WAKUI (Tohoku Univ. CYRIC)
Shin-ichi WATANABE (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Yutaka WATANABE (Inst. of Particle and Nucl. Studies, KEK)
Shuwei XU (Chinese Academy of Sci., China)
Kazuhiro YABANA (Univ. of Tsukuba, Inst. of Phys., Nucl. Theory Group)
Kentaro YAKO (Grad. Sch. of Sci., Univ. of Tokyo)
Takayuki YAMAGUCHI (Saitama Univ.)
Hidetoshi YAMAGUCHI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Shoichi YAMAKA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Norio YAMAZAKI (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Yanlin YE (Peking Univ., China)
Naotaka YOSHINAGA (Faculity of Sci., Saitama Univ.)
Akira YOSHINO (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Chongcheoul YUN (Chung-Ang Univ., Korea)
Tao ZHENG (Peking Univ., China)
Yong ZHENG (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Shan-Gui ZHOU (Peking Univ., China)
Research Consultants
Kiyomi IKEDA
Shuhei YAMAJI
Toshimitsu YAMAZAKI
Students
Junior Research Associates
Hironori KUBOKI (Dept. Phys., Grad. Sch. Sci., Univ. of Tokyo)- 286 -

Takeo ONISHI (Grad. Sch. of Sci., Univ. of Tokyo)
Masaru SUZUKI (Grad. Sch. of Sci., Univ. of Tokyo,)Student Trainees
Takeshi AIBA (Grad. Sch. of Sci. & Tech. Niigata Univ.)
Guilherme AMADIO (Grad. Sch. of Sci., Univ. of Tokyo)
Yoki ARAMAKI (Grad. Sch. of Sci., Univ. of Tokyo)
Tae-Eun CHOI (Ewaha Womans Univ., Korea)
Vincenzo CRUCILLA (Univ. of Catania, Italy)
Binh DAM (Inst. Theoretical Phys., Vietnam)
Koutaro FUJIKAKE (Sch. of Sci. and Tech., Meiji Univ.)
Yukihiro FURUKAWA (Dept. of Phys., Tohoku Univ.)
Taku GUNJI (Grad. Sch. of Sci., Univ. of Tokyo)
Seiya HAYAKAWA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Toshikazu HORI (Grad. Sch. of Sci., Osaka Univ.)
Wataru HORIUCHI (Grad. Sch. of Sci. & Tech. Niigata Univ.)
Takeshi HOYA (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba,)
Kiyohiko INAFUKU (Dept. of Phys., Tohoku Univ.)
Kenichi ISHII (Fac. of Sci., Rikkyo Univ.,)
Tatsuhiro ITO (Dept. of Sci. and Tech., Meiji Univ.)
Chen JUN (McMaster Univ., Canada)
Hyo-Soon JUNG (Chung-Ang Univ., Korea)
David KAHL (McMaster Univ., Canada)
Tomomi KAWAHARA (Grad. Sch. of Sci., Toho Univ.)
Jung-Lan KIM (Ewaha Womans Univ., Korea)
Jang Youl KIM (Chung Ang Univ., Korea)
Aram KIM (Ewaha Womans Univ., Korea)
Mituhisa KITAYAMA (Dept. of Phys., Tohoku Univ.)
Kei KOBAYASHI (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Yosuke KONDO (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech.)Takamasa KUBOKI (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Kenichiro KURA (Sch. of Sci., Osaka Univ.)
Yuzo KURIHARA (Grad. Sch. of Sci. and Eng., Tokyo Metropolitan Univ.)
Young Kwan KWON (Chung Ang Univ., Korea)
Livio LAMIA (Univ. of Catania, Italy)
Ki-Woo LEE (Chung-Ang Univ., Korea)
Juhahn LEE (Chung Ang Univ., Korea)
Tomohiro MACHIDA (Fac. of Sci., Rikkyo Univ.,)
Tetsuya MASUDA (Fac. of Sci., Rikkyo Univ.,)
Toshiyuki MASUE (Grad. Sch. of Sci., Osaka Univ.)
Yohei MATSUDA (Dept. of Phys., Tohoku Univ.)
Ryohei MATSUMIYA (Grad. Sch. of Sci., Osaka Univ.)
Yuuichi MATSUYAMA (Fac. of Sci., Rikkyo Univ.,)
Kenjiro MIKI (Grad. Sch. of Sci., Univ. of Tokyo)
Kazutaka MIYAKAWA (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba,)
JunYoung MOON (Chung Ang Univ., Korea)
Tetsuaki MORIGUCHI (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba)
Yuhei MORINO (Grad. Sch. of Sci., Univ. of Tokyo)
Takumi NAKABAYASHI (Grad. Sch. of Sci.,Tokyo Inst. of Tech.)
Shinpei NAKAJIMA (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Takashi NANNICHI (Sch. of Sci., Tokyo Inst. of Tech.)
Shumpei NOJI (Sch. of Sci., Univ. of Tokyo,)
Susumu ODA (Grad. Sch. of Sci., Univ. of Tokyo)
Naoto OKAICHI (Sch. of Sci., Tokyo Inst. of Tech.)
Hooi Jin ONG (Grad. Sch. Sci., Univ of Tokyo)
Shota SAITO (Grad. Sch. of Sci., Univ. of Tokyo)
Satoshi SAKAGUCHI (Grad. Sch. of Sci., Univ. of Tokyo)
Satoshi SANO (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Yoshiko SASAMOTO (Grad. Sch. of Sci., Univ. of Tokyo)
Masaki SASANO (Grad. Sch. of Sci., Univ. of Tokyo)
Maria SERGI (Univ. of Catania, Italy)- 287 -

KIANA SETOODEHNIA (McMaster Univ., Canada)
Tomoyuki SHIMAMURA (Sch. of Sci., Tokyo Inst. of Tech.)
Mayuko SHINOHARA (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech.)
Susumu SHIMOURA (CNS, Grad. Sch. Sci., Univ. of Tokyo)
Syota SUGAWARA (Sch. Sci. Eng., Waseda Univ.)
Tomokazu SUZUKI (Tohoku Univ. RI senter)
Hiroshi SUZUKI (Grad. Sch. of Sci., Univ. of Tokyo)
Kunihiko TAJIRI (Sch. of Sci., Osaka Univ.)
Maya TAKECHI (Grad. Sch. of Sci., Osaka Univ.)
Hidemitsu TAKEDA (Fac. of Sci., Kyusyu Univ.,)
Tasutaka TANIGUCHI (Grad. Sch. of Sci., Kyoto Univ.)
Yasuhiro TOGANO (Fac. of Sci., Rikkyo Univ.,)
Yorito YAMAGUCHI (Grad. Sch. of Sci., Univ. of Tokyo)
Yuji YAUCHI (Fac. of Sci., Dept. of Phys., Rikkyo Univ.,)
Jung-Sook YOO (Ewaha Womans Univ., Korea)
Akira YOSHIDA (Grad. Sch. of Sci., Kyoto Univ.)
Michiori YOSHITAKE (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Secretaries
Tomoko IWANAMI
Shinko ODAI
Kayoko WADA

- 288 -

Applied Nuclear Physics Laboratory
1. Abstract
The Laboratory conducts the microscopic investigation of physical and chemical processes by nuclear techniques
which take advantage of the intrinsic nuclear properties and phenomena (spins, electromagnetic moments, decay
modes etc.). In particular, the precession/resonance of a polarized/aligned nuclear spin under an external ﬁeld isobserved through change in the angular distribution of radiation, for the study of nuclear structures via nuclear
moments. The same method, as well as the Moessbauer technique, are used for the investigation of condensed
matter such as ferromagnets, fullerenes, systems with dilute magnetic impurities etc. by capitalizing radioactive
nuclei as microscopic probes into them. Also, the laser-polarization of stable/unstable nuclei and the spin maser
technique are being developed for application to fundamental interaction studies through high-precision measurement of the spin precession frequency. All these research activities are to be extended to wide variety of unstable
nuclei which the forth-coming facility, RI Beam Factory (RIBF), will provide. A method to produce beams ofhighly polarized radioactive nuclei, taking full advantage of RIBF, is being developed.
2. Major Research Subjects(1) Nuclear structure study of unstable nuclei through electromagnetic moments and γ-ray spectroscopy(2) Condensed matter studies with radioactive nuclear probes(3) Test of the standard model through β-decay and laser-nuclear spin interaction(4) Development of highly polarized slow RI beams
3. Summary of Research Activity
The Laboratory conducts studies covering nuclear physics, solid state physics/chemistry, and fundamental interactions, through the observation of nuclear spin, electromagnetic moments, and β and γ decays. Speciﬁcally,
structures and interactions in nuclei in the regions far from the β stability line are studied through the observationof ground- and excited-state properties such as the magnetic moments, electric quadrupole moments and decay
characteristics. For the determination of magnetic moments and electric quadrupole moments, the asymmetric/anisotropic emission of β or γ rays from spin-polarized/aligned nuclei are utilized to detect nuclear magnetic
resonance or spin precession. The same methods, as well as the Mössbauer technique, are also used for the investigation of condensed matter such as ferromagnets, semiconductors, systems with dilute magnetic impurities etc.
by capitalizing radioactive nuclei as microscopic probes into them. Also, the laser-polarized stable/unstable nuclei
are used for fundamental interaction studies through high-precision measurement of spin precession frequency. All
these research activities are to be extended to wide variety of unstable nuclei which the forth-coming facility, RI
Beam Factory (RIBF), will provide. A method to produce ultra-low energy beams of highly polarized radioactive
nuclei, taking full advantage of RIBF, is being developed.
(1) Nuclear structure studies with radioactive nuclear beams
Taking advantage of the β-NMR method with the spin-polarized radioactive-isotope beams (RIBs) produced
from the projectile fragmentation reaction, the ground-state electric-quadrupole moments for 32 Al was measured.
The µ-moment results presented above have provided scope for the neutron-rich aluminum isotopes viewed mainly
from nucleon occupancy in the diﬀerent single-particle orbits. The structural change would be investigated in amore straightforward way through the measurement of their Q moments because of its high sensitivity to nuclear
deformation. From the obtained nuclear quadrupole resonance spectrum, we have determined experimental Q
moment |Qexp [32 Al]| = 24(2) emb. We found that the obtained |Qexp | takes a very small value of 24(2) emb,whereas near the stability line value of |Qexp | stays almost constant at |Q| ∼ 150 emb. This observation indicatesthat the ground-states shape of the neutron-rich aluminum isotopes stays spherical when N = 19 is approached,
and the ground state of 32 Al is the normal state described by valence particles in the sd orbits. It is interesting
to note that the observed normal character of 32 Al is in contrast to that of 31 Mg, for which anomalous nuclear
structure has been reported despite that these two nuclei diﬀer only in the proton number. The |Qexp | values arecompared with shell-model calculations.
(2) Applications of Unstable RI Beams to Condensed Matter Studies(K. Asahi, Y. Kobayashi, H. Ueno, A. Yoshimi, H. Watanabe1∗ , T. Okada2∗ , M. K. Kubo2∗ , Y. Yamada2∗ ,M. Murata2∗ , Y. Einaga2∗ , Y. Nagata2∗ , T. Taniguchi2∗ , T. Kurahashi2∗ , E. Yagi2∗ , Y. Yoshida2∗ , H. Ogawa2∗ ,W. Sato2∗ , K. Asai2∗ , J. Nakamura2∗ , S. Nasu2∗ , J. Miyazaki2 *, T. Fujita3∗ , Y. Nemoto3∗ , H. Nonaka3∗ , K.
Kawaguchi3∗ , K. Taguchi3∗ , Y. Ono3∗ , Ohkubo3∗ , Nakamoto3∗ , H. Miyoshi3∗ , D. Kameda3∗ , K. Shimada3∗ , T.
Kato3∗ , Emori3∗ ；H. Haba, A. Yoshida, M. Kase, A. Goto, Y. Yano (Cyclotron Center))1* Contract Researcher, 2 * Visiting Researcher, 3 * Trainee- 289 -

In-beam Mössbauer spectroscopic studies using an unstable short-lived nuclei 57 Mn (T1/2 = 1.45 min) beam
have been performed to investigate the “exotic” chemical states and the fast atomic-jump processes in solid.
In this period, we have carried out a 57 Mn in-beam Mössbauer experiment to study the electronic structures,
especially “exotic” chemical species, of 57 Fe atoms decaying from 57 Mn implanted into a silicon wafer and solid
oxygen. In more reactive matrices, Fe species with extraordinarily higher oxidation states and “exotic” chemical
structures are expected to be produced. Reactions between localized Fe atoms and reactant O2 molecules provide
important information on chemistry under non-equilibrium conditions and on the production of novel species.
We succeed to obtain the well-deﬁned in-beam 57 Fe (←57 Mn) Mössbauer spectra of solid O2 at 18 and 30 K. The
spectrum obtained at 18 K can be analyzed by four components of doublets. They are preliminarily assigned to beFe(O2 ), FeO, (O2 )Fe(O2 ), and an exotic high oxidation state of Fe species, respectively. The 57 Mn implantation
Mössbauer experiment has been applied to the diﬀusion study of Fe impurity in Si, too. From the temperaturedependence of the area intensities and the isomer shifts in the in-beam Mössbauer spectra, it is found that a fast
diﬀusion of interstitial Fe atoms occurs over 500 K, and that there are a motional averaging between substitutional
and interstitial Fe atoms in Si.
Another type of in-beam Mössbauer study using neutron beam has been continued. The advantage of thistechnique is that it is possible to investigate non-destructively the chemical eﬀects and the dynamics of a hot
atom produced just after the nuclearreaction. The Mössbauer spectrometer using the prompt γ-rays was installed
at a neutron beam line at JRR-3M, Japan Atomic Research Institute. We succeeded to obtained the in-beamMössbauer spectra of FeS2 (pyrite- and marcasite-type) at room temperature. The spectra obtained at room
temperatures can be ﬁtted two doublets. Ones of doublets are originated from host matrix of pyrite and marcasite,
the others are suggested to be novel Fe species produced by neutron capture reaction.
We studied the magnetic stable state and the antiferromagnetic ordering mechanism of (Ca, Sr)RuO3 systemand the characterizations of a ﬁlled-skutterudite, SmRu4 P12 , by 99 Ru Mössbauer spectroscopy and magnetization
measurement. The 83 Rb source for 83 Kr Mössbauer spectroscopy was produced by a chemical separation after
the a-irradiation of CaBr2 .
57
Fe Mössbauer spectroscopy was applied to investigate the structural conversion and spin separation triggeredby proton-coupled electron transfer in p-conjugated ferrocene-quinone and ferrocene-naphthoquinone system, andthe exotic valence states of Fe atoms in salen complex as a model for active sites of mononuclear non-heme ironenzymes.
(3) Fundamental symmetry studies with spin-polarized nuclei
The development of a low-frequency nuclear spin maser with 129 Xe for application to the search for a permanentelectric dipole moment (EDM) is in progress. Key point of this project is to measure a small frequency shift ofthe spin precession by using the continuously precessing nuclear spin.
The performance of the good homogeneous solenoid coil for a low static ﬁeld and high-stability current source
for the solenoid coil was investigated. In the previous investigation the major source of the frequency ﬂuctuation
in a spin maser was traced to be a ﬂuctuation in the solenoid ﬁeld, which turned out to be originated from acurrent source in the previous setup with a nominal current stability of 10−4 . The newly developed current source
includes a low noise circuit as the voltage reference, and a stability of 10−6 has been conﬁrmed with a precisionammeter. This corresponds to a ﬁeld ﬂuctuation of a 10 nG order. The spin precession of 129 Xe nucleus wasobserved in thus stabilized magnetic ﬁeld. The χ2 -ﬁtting with a single frequency sine wave times exponential
decay function can be performed for the measured free precession signal which continued 500-600 seconds after
the 90 degree NMR pulse. The frequency error was found to be 1 µHz. In the previous setup, such a χ2 -ﬁtting
could not be performed. The measurement of the maser oscillation in this new setup is now in progress and theimprovement of the frequency stability in the long-term. We have also launched the construction of the electrodesystem to produce the electric ﬁeld for the EDM experiment. The mesh-type electrodes were made in order topath the probe laser light for magnetometry through the glass cell and the electrodes. We are now trying to
reduce the leak current in this electrode system.

Head
Koichiro ASAHI
Members
Yoshio KOBAYASHI
Akihisa SHIRAHAMAYOSHIMI
Hideki UENO

- 290 -

Special Postdoctoral Researchers
Daisuke KAMEDA
Takashi NAGATOMO
Contract Researcher
Takashi SUGIMOTO
Visiting Scientists
Hisazumi AKAI (Grad. Sch. Sci. Eng., Osaka Univ.)
Yasuaki EINAGA (Fac. Sci. Eng., Keio Univ.)
Kazuo HAYAKAWA (Shizuoka Inst. of Sci. and Tech.)
Koji HIGASHIYAMA (Grad. Sch. of Sci., Univ. of Tokyo)
Norimichi KOJIMA (Grad. Sch., College of Arts and Sci., Univ. of Tokyo)
Kenya KUBO (Div. Natl. Sci., Int. Chr. Univ.)
Takuya KURAHASHI (Inst. Mol. Sci.)
Jun MIYAZAKI (Fac. Sci., Tokyo Univ. of Sci.)
Jiro MURATA (Fac. Sci., Rikkyo Univ.)
Masaki MURATA (Grad. Sch. of Sci., Univ. of Tokyo)
Kazuo MUTO (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)Yujiro NAGATA (Coll. Sci. Technol., Aoyama Gakuin Univ.)
Hiromichi NAKAHARA (Tokyo Metropolitan Univ.)
Jin NAKAMURA (Dep. Appl. Phys. and Chem., Univ. Electro-Commun.)
Saburou NASU (Grad. Sch. Eng. Sci., Osaka Univ.)
Hiroshi OGAWA (Natl. Inst. Adv. Ind. Sci. Tech.)
Hiroyuki SAGAWA (The Univ. of Aizu, Center for Mathematical Sci.)
Wataru SATO (Grad. Sch. Sci. Eng., Osaka Univ.)
Tadashi SHIMODA (Grad. Sch. Sci. Eng., Osaka Univ.)
Satoshi TSUTSUI (JASRI)
Makoto UCHIDA (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)
Masahiko UTSURO (Kyoto Univ. Res. Reactor Inst.)
Hiroshi WATANABE (Dept. of Nucl. Phys., The Australian National Univ., Australia)
Schmidt-Ott WORF-DIETER (The Univ. of Goettingen, Germany)
Eiichi YAGI (Sch. Sci. Eng., Waseda Univ.)
Yasuhiro YAMADA (Fac. Sci., Tokyo Univ. of Sci.)
Yutaka YOSHIDA (Fac. Sci. Technol., Shizuoka Inst. Sci. Technol.)Research Consultant
Takuya OKADA
Visiting Researcher
Langouche GUIDO (Dept. of Phys. and Astronomy, Katholieke Universiteit Leuven, Belgium)
Students
Junior Research Associates
Daisuke NAGAE (JAEA)
Kenji SHIMADA (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)Student Trainees
Masahiko ADACHI (Fac. Sci. Technol., Shizuoka Inst. Sci. Technol.)Takamasa ARAI (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)
Hideki FUKASAWA (Grad. Sch. of Sci., Tokyo Univ. of Sci.)
Yuka FUNAYAMA (Div. Natl. Sci., Int. Chr. Univ.)
Yuta HASEGAWA (Grad. Sch. of Sci., Univ. of Tokyo)
Naoto HATAKEYAMA (Fac. Sci., Tokyo Inst. Technol.)Takeshi INOUE (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)
Sota KAGAMI (Fac. Sci., Tokyo Inst. Technol.)
Tomoko KAKUYAMA (Div. Natl. Sci., Int. Chr. Univ.)
Tomohiro KAMIMURA (Fac. Sci. Technol., Shizuoka Inst. Sci. Technol.)
Hirokazu KATO (Fac. Sci., Tokyo Univ. of Sci.)
Hirokazu KAWAMURA (Grad. Sch. Sci., Rikkyo Univ.)
Mio KONDO (Grad. Sch. of Sci., Univ. of Tokyo)- 291 -

Katsuhiro KOUNO (Grad. Sch. of Sci., Tokyo Univ. of Sci.)
Namiko MIURA (Fac. Sci. Technol., Shizuoka Inst. Sci. Technol.)
Keigo NARITA (Grad. Sch. Sci., Rikkyo Univ.)
GUILLAUME PEDOUSSAUT (Div. Natl. Sci., Int. Chr. Univ.)
Kazumasa SAKATA (Fac. Sci. Technol., Grad. Sch. of Shizuoka Inst. Sci. Technol.)Yutaka SUZUKI (Fac. Sci. Technol., Shizuoka Inst. Sci. Technol.)
Kunifumi SUZUKI (Fac. Sci. Technol., Grad. Sch. of Shizuoka Inst. Sci. Technol.)
Kaori TAGUCHI (Grad. Sch. of Sci. and Eng., Tokyo Metropolitan Univ.)
Kenichi TAKASE (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)
Makoto TAKEMURA (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)Takeshi TOYODA (Fac. of Sci., Rikkyo Univ.)
Yoji TSURUOKA (Div. Natl. Sci., Int. Chr. Univ.)
Ryousuke TSUTSUI (Grad. Sch. Sci., Rikkyo Univ.)
Maai UCHIKAWA (Grad. Sch. of Sci., Univ. of Tokyo)
Secretaries
Shizue UMEBAYASHI
Kayoko WADA

- 292 -

Radioactive Isotope Laboratory
1. Abstract
This laboratory explores exotic nuclear structures and dynamics in unstable 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 to discover new phenomena and properties in unstable nuclei.
Another important subject is the equation-of-state of asymmetric nuclear matter, and its association with theorigin of elements and with neutron stars. For instance, we are making attempts to the better understand underlyning mechanism for exotic stability-enhancements of very neutron-rich ﬂuorine isotopes, the large deformationof the nucleus 34Mg with N=22 in spite of its vicinity to the N=20 magic neutron number and anomalous collectivity in 16C. We are further extending these studies to medium- and heavy-mass regions by developing facilities,
detectors and unique methods at RIBF, thereby leading on the challenging task to ﬁnd new exotic phenomena.
We also perform numerical simulations of nucleosynthesis under the environment of core-collapse supernovae, andmoreover quest for footprints of supernovae and solar activities in the past, embedded in Antarctic ice core, incollaboration with Cosmic radiation laboratory and National Institute of Polar Research.
2. Major Research Subjects(1) Study of structure and dynamics of unstable nuclei through development of new methods utilizing fast RI
beamsI beams(2) Stability of exotic nuclei and exploration into limit of nuclear existence(3) Research on equation-of-state in asymmetric nuclear matter via heavy-ion induced reaction(4) Promotion of nuclear astrophysics in an interdisciplinary organization
3. Summary of Research Activity(1) Program based on missing mass method
Missing mass method is an essential tool to identify and observe both bound and unbound states. Especiallyfor highly excited states beyond particle threshold, any models of particle and gamma decay processes are notnecessary in reconstructing excitation energy. Diﬃculties stemming from inverse kinematics are low energy ofrecoiled out particles from targets and high accurate measurement necessary for emission angles. To overcome thediﬃculties, we are developing new detection systems for proton (in)elastic scattering; ESPRI(Elastic Scatteringof Proton with RI beam), and a magnetic spectrometer for particles emitted at zero degree. The two systems
have been employed for light mass nuclei for matter distributions as well as spectroscopic studies.
(2) Program based on 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 and development of in-beamgamma methods ﬁt for the reactions is necessary. So far, we have developed two-step fragmentation method as aneﬃcient method to identify and populate excited states, and lifetime measurements to deduce transition strength.
(3) beta spectroscopy
Beta-spectroscopy is a traditional and eﬃcient method for nuclear spectroscopy, especially out non-yrast levels.
In the light mass region, several light-mass nuclei in both neutron-rich and proton-rich region have been investigated at RIPS through beta-gamma and beta-p coincidence technique. Concerning the medium and heavy mass
region available at RIBF, we are developing two position-sensitive active-stoppers to achieve low-background via
position correlation; strip-silicon detectors and a cylindrical active stopper called CAITEN.
(4) Equation-of-state via heavy-ion central collisions
Eos in asymmetric nuclear matter is essentially important to understand mechanism of supernovae explosion as
well as crust structure of neutron stars. We are designing an experimental setup to detect pions and multiplicity
in central collisions with RIBs at the intermediate energy at RIBF.
(5) Interdisciplinary study for nuclear astrophysics
To understand the origin of elements beyond ion, interdisciplinary works are important in linking data from
nuclear physics program. We are promoting simulation of nucleosynthesis in the r- process path, and investigation of Antarctic ice core to search for footprints of supernovae as well as solar activity in the past via mass
spectrometer, to link data obtained from nuclear physics program.

Head- 293 -

Hiroyoshi SAKURAI
Members
Takashi ICHIHARA
Takashi KISHIDA
Yoichi NAKAI
Shunji NISHIMURA
Hideaki OTSUHeiko SCHEIT
Special Postdoctoral Researcher
Toshiyuki SUMIKAMA
Hiroyuki TAKEDAEri TAKESHITA
Kanenobu TANAKA
Satoru TERASHIMA
Masayuki YAMAGAMI
Contract Researcher
Makoto ITO
Yuko MOCHIZUKI
Hideki MADOKORO
Senior Visiting Scientist
Wolfgang MITTIG (GANIL, France)
Visiting Scientists
Sachiko AMARI (Washington Univ.,USA)
Xiangzhou CAI (Shanghai Inst. Applied Phys., China)
Alfred DEWALD (Univ. Cologna Insti. Nucl. Phys.)
DEQING FANG (Shanghai Inst. Applied Phys., China)
Adrian GELBERG (Univ. zu KoelnInst. Fur Kern Physik, Germany)
Wei GUO (Shanghai Inst. Applied Phys., China)
Hiroyuki KOURA (JAEA)YUGANG MA (Shanghai Inst. Applied Phys., China)
Masayuki MATSUO (Grad. Sch. of Sci. and Tech., Niigata Univ,)
Tetsuo NORO (Kyusyu Univ. Fac. of Sci.)
YURI PENIONZHKEVICH (Flerov Lab. Nucl. Reactions, JINR, Russia)
Ryoichi SEKI (California State Univ., Northridge, USA)
Takahiro TACHIBANA (Waseda High Sch., Waseda Univ.)
Kohji TAKAHASHI (Universite Libre de Bruxelles, Belgium)
Noboru TAKIGAWA (Fac. of Sci., Tohoku Univ.,)
OLEG TARASOV (MSU, NSCL, USA)
Ryouichi WADA (Texas A&M Univ., USA)
Juzo ZENIHIRO (Grad. Sch. of Sci., Kyoto Univ.)
Research Fellow
Lisheng GENG (Beijin Univ., CHINA)
Students
Junior Research Associates
Yuichi ICHIKAWA (Grad. Sch. of Sci., Univ. of Tokyo)
Taro NAKAO (Grad. Sch. of Sci., Univ. of Tokyo)
Megumi NIIKURA (Grad. Sch. of Sci., Univ. of Tokyo)
Takeo ONISHI (Grad. Sch.. of Sci., Univ. of Tokyo)
Masaru SUZUKI (Grad. Sch. of Sci., Univ. of Tokyo,)Student Trainees
Yuhei HASHIZUME (Grd. Sch. of Pure and Applied Sci.,Univ. of Tsukuba)
Yoshihiko IWAO (Grad. Sch. of Sci., Kyoto Univ.)
Hitomi KIMURA (Grad. Sch. of Sci., Univ. of Tokyo)- 294 -

Hiroaki MATSUMOTO (Grad. Sch. of Sci., Kyoto Univ.)
Hooi Jin ONG (Grad. Sch. Sci., Univ of Tokyo)
Akio SHIRAKI (Grad. Sch. of Sci., Univ. of Tokyo)
Daisuke SUZUKI (Grad. Sch. of Sci., Univ. of Tokyo)
Secretary
Shizuka KATO

- 295 -

Superheavy Element Laboratory
1. Abstract
The elements with their atomic number Z>103 are called as trans-actinide or superheavy elements. The
chemical properties of those elements have not yet been studied in detail. Those elements do not exist in nature
therefore, they must be produced by artiﬁcially for the scientiﬁc 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) Search for new supreheavy elements(2) Decay spectroscopy of the heaviest nuclei(3) Study of the chemical properties of the heaviest elements(4) 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 studyof 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 newfrontier in the ﬁeld of chemistry. Relativistic eﬀects in chemical property are predicted by many theoreticalstudies. 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, thereaction mechanism of the fusion process is still not well understood theoretically. When we design an experiment
to synthesize nuclei of the superheavy elements, we need to determine a beam-target combination and the mostappropriate 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.

Head
Kosuke MORITA
Members
Hiromitsu HABA
Kouji MORIMOTO
Special Postdoctoral Researcher
Takatoshi ICHIKAWA
Daiya KAJI
Contract Technical Scientist
Akira YONEDA
Research Associate
Hidetoshi KIKUNAGA
Visiting Scientists
Masato ASAI (Japan Atomic Energy Agency)
Shin-ichi GOTO (Niigata Univ.)
Kouichi HAGINO (Tohoku Univ.)
Hisaaki KUDO (Fac. Sci., Niigata Univ.)
Tetsuya MURAKAMI (Grad. Sch. Sci., Kyoto Univ.)
Keisuke SUEKI (Grad. Sch. Pure Appl. Sci., Univ. Tsukuba)
Fuyuki TOKANAI (Dept. Phys., Yamagata Univ.)- 296 -

Research Consultants
Takashi INAMURA
Kenji KATORI
Toru NOMURA
Students
Junior Research Associate
Takahiro AKIYAMA (Saitama Univ.)
Part-time Staﬀ I(Research Support)
Nozomi SATO (Grad. Sch. Sci. Eng., Tohoku Univ.)
Student Trainees
Tomohiro NANRI (Dept. Chem., Kanazawa Univ.)
Itsuro YAMAZAKI (Dept. Chem., Kanazawa Univ.)- 297 -SLOWRI Team
1. Abstract
A next-generation slow radioactive nuclear ion beam facility (SLOWRI) which provides slow, high-purity andsmall emittance ion beams of all elements is being build as one of the principal facilities at the RIKEN RIbeam factory (RIBF). High energy radioactive ion beams from the projectile fragment separator BigRIPS are
thermalized in a large gas catcher cell. The thermalized ions in the gas cell are guided and extracted to a
vacuum environment by a combination of dc electric ﬁelds and inhomogeneous rf ﬁelds (rf carpet ion guide).
From there the slow ion beam is delivered via a mass separator and a switchyard to various devices: such as an
ion trap, a collinear fast beam apparatus, and a multi-reﬂection time of ﬂight mass spectrometer. In the R&D
works at the present RIKEN facility, an overall eﬃciency of 5% for a 100 A MeV 8 Li ion beam from the present
projectile fragment separator RIPS was achieved and the dependence 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 10 Be
and 7 Be from the RIPS were trapped and laser cooled in a linear rf trap and the speciﬁc mass shifts of theseisotopes were measured for the ﬁrst time. The evaluated ion temperature of about 1 K demonstrates that a
reduction of more than 13 orders of magnitude for the kinetic energy of radioactive Be was achieved online.
Precise investigation of the hyperﬁne structure will conﬁrm the anomalous mean radius of the valence neutron of
the so called neutron halo nucleus.
Other spectroscopy experiments using the slow RI-beams are also under progress in oﬀ-line setups. A collinear
fast beam apparatus for nuclear charge radii measurements was build and tested with stable Ar+ ion beams.
A multi-reﬂection time-of-ﬂight mass spectrograph was build for precise and fast measurements of short-lived
radioactive nuclei. A high mass resolving power of 100,000 has been achieved with a 3 ms measurement period.
2. Major Research Subjects(1) Development and constraction of the next-generation slow RI-beam facility(2) Precision hyperﬁne spectroscopy of trapped ions for magnetization distribution in a halo nuclues(3) Nuclear charge radii measurements using ion trap and collinear fast beam apparatus(4) Precision mass measurements of short-lived nucei using a multi-reﬂection TOF mass spectrograph(5) Development of deceleration and cooling devices for energetic beams using gas cell and rf ﬁelds.
(6) Atomic physics and fundamental symmetry research investigating nuclear decay of an isolated atom
3. Summary of Research Activity(1) Development of universal slow RI-beam facility
WADA, Michiharu, NAKAMURA, Takashi, TAKAMINE, Aiko, ISHIDA, Yoshihisa, OKADA, Kunihiro,
LIOUBIMOV Vladimir, KANAI, Yasuyuki, YOSHIDA, Atsushi, KUBO, Toshiyuki, YAMAZAKI, Yasunri,
WOLLNIK, Hermann, SCHUESSLER, Hans, NODA, Koji, OHTANI, Shunsuke, KATAYAMA Ichiro
A next-generation slow radioactive nuclear ion beam facility (SLOWRI) which provides slow, high-purity andsmall emittance ion beams of all elements is being build as one of the principal facilities at the RIKEN RIbeam factory (RIBF). High energy radioactive ion beams from the projectile fragment separator BigRIPS are
thermalized in a large gas catcher cell. The thermalized ions in the gas cell are guided and extracted to a
vacuum environment by a combination of dc electric ﬁelds and inhomogeneous rf ﬁelds (rf carpet ion guide).
From there the slow ion beam is delivered via a mass separator and a switchyard to various devices: such as an
ion trap, a collinear fast beam apparatus, and a multi-reﬂection time of ﬂight mass spectrometer. In the R&D
works at the present RIKEN facility, an overall eﬃciency of 5% for a 100 A MeV 8 Li ion beam from the present
projectile fragment separator RIPS was achieved and the dependence of the eﬃciency on the ion beam intensity
was investigated.
(2) Laser spectroscopy of trapped radioactive beryllium isotope ions
WADA, Michiharu, NAKAMURA, Takashi, TAKAMINE, Aiko, ISHIDA, Yoshihisa, OKADA, Kunihiro,
LIOUBIMOV Vladimir, KANAI, Yasuyuki, YOSHIDA, Atsushi, KUBO, Toshiyuki, YAMAZAKI, Yasunori,
WOLLNIK, Hermann, SCHUESSLER, Hans, NODA, Koji, OHTANI, Shunsuke, KATAYAMA Ichiro
As a ﬁrst application of the prototype SLOWRI setup, we are applying hyperﬁne structure spectroscopy tothe beryllium isotopes to determine in particular the anomalous radius of the valence neutron of the neutron
halo nucleus 11 Be, and to determine the charge radii of these beryllium isotopes through laser-laser double resonance spectroscopy of laser-cooled ions. Laser cooling is an essential prerequisite for these planned experiments.
However, the exact resonance frequencies of the cooling transitions for radioactive beryllium isotopes are not- 298 -

known. In such light elements, the isotope shifts in the atomic transitions are larger than several 10 GHz andtheir dominant parts are due to complicated multi-electron correlations. Some theoretical works on the isotope
shifts of the beryllium ion exist, however the values contradict each other at the level of accuracy needed.
The laser spectroscopy experiments for beryllium isotopes were performed at the prototype SLOWRI setup of
the existing accelerator facility. The resonant frequencies of 2s 2 S1/2 - 2p 2 P3/2 transition of 7 Be+, 9 Be+ and
10
Be+ ions were determined to be 957,347.37(11) GHz, 957,396.515(14) GHz and 957,414.839(35) GHz, respectively. Then we determined the transition frequency of inﬁnitely heavy 957,569.55(28) GHz and the diﬀerential
mass polarization parameter 1,884.5(46) THz, for the ﬁrst time.
Hyperﬁne structure spectroscopy of Be isotopes using the laser-microwave double resonance method to determine the Bohr-Weisskpf eﬀect is also in progress.
(3) Development of a multi-reﬂection TOF mass spectrograph
WADA, Michiharu, ISHIDA, Yoshihisa, NAKAMURA, Takashi, TAKAMINE, Aiko, OKADA, Kunihiro,
YAMAZAKI, Yasunori, WOLLNIK, Hermann,
The atomic mass is one of the most important quantity of a nucleus and has been studied in various methods
since the early days of physics. 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 arepetition rate of ∼500 Hz. The spectrometer consists of two electrostatic mirrors between which the ions travelback and forth repeatedly. These mirrors are designed such that energy-isochrononicity in the ﬂight time isguaranteed during the multiple reﬂections while the ﬂight time varies with the masses of ions. A mass-resolving
power of > 200,000 has been obtained with ∼500 reﬂections in a 30 cm length spectrometer. This mass-resolving
power should allow us to determine ion masses with an accuracy of 10−7 . This accuracy is lower than thatobtained in a Penning trap mass spectrometer, however, it is suﬃcient to study many r-process nuclides, forinstance. The advantages of the MR-TOF spectrometer are: 1) short measurement periods, typically 2 ms, whichallows all neutron rich nuclei to be investigated, 2) the device is compact and its operation is simple, especially, it
is independent from the all upstream devices, accelerators and fragment separators, 3) ions of more than isobars
can be measured simultaneously, so that mass reference can easily be established in the mass spectra. In total,
the number of measurable nuclides within a limited beam time would be larger than that can be achieved byother methods. It should be noted here also that this method can be used even during a low-duty parasite beamtime.
(4) Development of collinear fast beam apparatus for nuclear charge radii measurements
WADA, Michiharu, LIOUBIMOV Vladimir, SCHUESSLER, Hans, IIMURA, Hideki, ISHIDA, Yoshihisa,
NAKAMURA, Takashi, TAKAMINE, Aiko, OKADA, Kunihiro, YAMAZAKI, Yasunori, WOLLNIK, Hermann,
The root-mean-square charge radii of unstable nuclei have been determined exclusively by isotope shift measurements of the optical transitions of singly-charged ions or neutral atoms by laser spectroscopy. Many isotopes ofalkaline, 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 at conventional 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. Thisshould expand the range of applicable nuclides of laser spectroscopy. In the ﬁrst years of the RIBF project, Ni
and its neighboring elements, such as Ni, Co, Fe, Cr, Cu, Ga, Ge are planned to be investigated. They all havepossible optical transitions in the ground states of neutral atoms with presently available laser systems. Some ofthem have so called recycle transitions which enhance the detection probabilities noticeably. Also the multistep
resonance ionization (RIS) method can be applied to the isotopes of Ni as well as those of some other elements.
The required minimum intensity for this method can be as low as 10 atoms per second.
We have builded 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 restwith more than 10−8 accuracy. Such high accuracy measurements for Ti and Ni isotopes are in progress.

Head
Hiroyoshi SAKURAI
Members
Michiharu Wada

- 299 -

R&D team for multiparticle spectrometer
1. Abstract
Main task of R&D team for multiparticle spectrometer is to make R&D on broad range multiparticle spectrometer SAMURAI (Superconducting Analyser for Multiparticles from RadioIsotope beams), which is planned to built
at BIBF for nuclear structure experiments using RI beams at RIBF. Design of the large superconducting magnet
is being designed helped by various companies. Various detectors necessary for large magnetic spectrometer are
being developed and tested.
2. Major Research Subjects(1) Design of large superconducting magnet system(2) R&D on High-accuracy/high-rate position detectors(3) R&D on High-accuracy velocity measuring detectors(4) R&D on High-accuracy total energy detectors
3. Summary of Research Activity(1) Design of Large Superconducting magnetic spectrometer(Kobayashi, Yoneda, Otsu, Kubo, Sekiguchi, Nakamura, Chiga, Iwasa, Murakami)
Basic design of large superconducting dipole magnet, which is central part of the SAMURAI system, is being
made in collaboration with outside companies.
(2) R&D of Various detectors for large superconducting magnetic spectrometer(Kobayashi, Otsu, Sato)As necessary detectors for large superconducting magnetic spectrometer, we have developed various dectors,
such as high-accuracy/high-rate position detectors, high-precision velocity detectors, high-precision total-energy
detectors. Their performances have been checked using heavy-ion beams at HIMAC accelerator facility.

Head
Hiroyoshi SAKURAI
Senior Visiting Scientist
Toshio Kobayashi (Grad. Sch. Sci. Fac. Sci., Tohoku Univ.)- 300 -

Polarized RI Beam Team
1. Abstract
The team conducts the research and development on production of spin-polarized/alignment RI beams, andapply it to the research on nuclear physics and material science. The microscopic investigation of physical andchemical processes is performed by nuclear techniques which take advantage of the intrinsic nuclear properties
and phenomena (spins, electromagnetic moments, decay modes etc.). In particular, the precession/resonance ofa polarized/aligned nuclear spin under an external ﬁeld is observed through change in the angular distribution ofradiation, for the study of nuclear structures via nuclear moments. The same method, as well as the Moessbauer
technique, are used for the investigation of condensed matter such as ferromagnets, fullerenes, systems with dilute
magnetic impurities etc. by capitalizing radioactive nuclei as microscopic probes into them. All these research
activities are to be extended to wide variety of unstable nuclei which the forth-coming facility, RI Beam Factory(RIBF), will provide. A method to produce beams of highly polarized radioactive nuclei, taking full advantage of
RIBF, is being developed.
2. Major Research Subjects(1) Production of spin-polarized RI beam with fragmentation reaction(2) Production of spin-alignment RI beam(3) Development of highly polarized slow RI beams(4) Development of radioactive nuclear probes for condensed matter studies
3. Summary of Research Activity(1) Production of fragment-induced spin polarization
In the production of RI beams with the projectile fragmentation reaction, spin-polarized RI beam can beproduced in the projectile-fragmentation reaction by selecting the appropriate scattering angle and outgoing
momentum. With the obtained spin-polarized nuclei, nuclear magnetic moments and electric quadrupole moments
have been determined by means of the b-NMR method through the change in the angular distribution of theemitted b rays. The nuclear structure has been investigated for the nuclei far from the stability line based on thismethod. The sub-themes are the following.
(1) Production of the spin-polarized neutron-rich Al isotopes from 40 Ar-primary beams and measurements of
the nuclear electro-magnetic moments. (Kameda, Ueno, Yoshimi, Sugimoto, Nagatomo, Shimada, Kobayashi)(2) Production of the spin-polarized 33-34 Al (N > 20) beams from 36 S-primary beams and measurements of
the nuclear electric-quadrupole moments (Nagatomo, Ueno, Yoshimi, Kameda, Sugimoto, Shimada)(3) Production of spin-polarized neutron-rich Si isotopes from 48 Ca-primary beams and measurements of thenuclear electro-magnetic moments. (Yoshimi, Ueno, Kameda, Sugimoto, Nagatomo, Shimada)(2) Production of spin-aligned RI beams(1) Production of spin-aligned nuclei is essentially important for the study on the nuclear structure through themeasurement of excited-state nuclear moments, which is also useful to material sciences. Various techniques ofthe production method for obtaining spin-aligned RI beams have been developed. Sub-themes are the following.
(2) Production of spin-aligned 32m Al beams in the projectile fragmentation and the measurement of the excitedstate nuclear moment. (Kameda, Ueno, Yoshimi, Sugimoto, Nagatomo, Shimada)
Production of spin-aligned 134m Ce beams as a probe of material science (Ueno, Kameda, Yoshimi, Shimada)(3) Development of a new method for the production of spin-aligned RI beams via the two-step fragmentation
reactions. (Ueno, Yoshimi, Kameda, Sugimoto, Nagatomo, Shimada)(4) Studies on the properties of Transient Field at the high-velocity region. (Ueno, Yoshimi, Kameda, Shimada)(5) Application of the Recoil-into-vacuum method to RI-beam experiments (Sugimoto, Yoshimi, Ueno)(3) Production of highly spin-polarized low-energy RI beams
New methods and devices have been developed for producing highly spin-polarized RI beams in low beam-energy
region to overcome diﬃculties expected in the above method 1. The high spin polarization and the low beamenergy are important not only for nuclear-moment measurements but also for spin-related subjects in nuclear
physics, fundamental physics, and material sciences. Sub-themes are the following.
(1) Development of a new atomic-beam resonance method to combine with fragmentation-based RI beams(Sugimoto, Yoshimi, Ueno)(2) Production of low-energy spin-polarized 17 N beams via the transfer reactions based on the inverse kinematics
and its application (Shimada, Sugimoto, Kameda, Yoshimi, Ueno)(4) Development of RI probes and application for the condensed matter sciences- 301 -

Utilizing RI beams as a probe, online Mössbauer spectroscopy and online perturbed angular correlation experiments have been carried out through the g-ray measurements. The microscopic structures, dynamics inferromagnets, and properties of semiconductors have been investigated from the deduced internal local ﬁelds andthe spin relaxation of the probe in materials. The methods and apparatus have been developed. Also, basic
studies on the probe nuclei have been carried out. Sub-themes are the following.
(1) Production of high quality 57 Mn beams for the online Mössbauer spectroscopy (Kobayashi, Ueno, Yoshimi,
Kameda)(2) Development of the on-line perturbed angular-correlation method with 19 O beams as a new probe(Kobayashi, Ueno, Yoshimi, Kameda, Shimada)Team Leader
Hiroyoshi SAKURAI
Members
Yoshio KOBAYASHI
Hideki UENO
Akihisa YOSHIMI- 302 -

Rare RI-ring Team
1. Abstract
We are developing the isochronous storage ring to measure the mass for rare radioactive isotopes (Rare RI ring).
It is assumed that uranium is synthesized by neutron capture process after the supernovae explosion (r-process).
To prove r-process, mass measurements for the rare RI is indispensable. It is possible to inject the rare RI one
by one to the ring (individual injection) since cyclotrons in RIBF provide continuous beams. To perform theindividual injection, we need a long injection line. The isochronous storage ring and the individual injection arevery unique system.
2. Major Research Subjects(1) Developments of isochronous storage ring to measure mass of rare RI(2) Developments of detectors for mass measurements
3. Summary of Research Activity(1) Developments of isochronous storage ring to measure mass of rare RI
We are improving conceptual designs for an isochronous storage ring, kicker magnets, and the injection line tothe storage ring. The storage ring consists of six sector magnets. The edge angles of each sector magnets compensate the first order isochronism. For the kicker magnets, we fixed rough specifications. For the injection line,
we performed the first order ion-optical calculations. Furthermore, we performed magnetic field measurements ofa present sector magnet in BigRIPS by using NMR with high accuracy on the last April.
(2) Developments of detectors for mass measurements
The group in Saitama University performed the experiment to measure the time resolution of thin plasticscintillators in HIMAC. The results show, for heavy ion beams with 200 A MeV, reasonably good timing resolution
can be achieved even in the thin scintillator with 10 micron thickness. The group in University of Tsukuba
measured a response time of Hybrid Photo Detector (HPD), which can replace with traditional Photo Multi Tube
(PMT). The results show that the response time of HPD is faster than that of PMT by about 10 ns.

Team Leader
Hiroyoshi SAKURAI
Research Associate
Yoshitaka YAMAGUCHI
Visiting Scientists
Akira OZAWA (Inst. Phys., Univ. of Tsukuba)
Yusuke YASUDA (National Inst. of Advanced Industrial Sci. and Tech.)- 303 -SCRIT Team
1. Abstract
We aim at the investigation of internal nuclear structure of short-lived radioactive nulei (RI) by means ofelectron scattering. Electron scattering for RI’s has never been performed duo to inability to make target of these
nuclei. An electron-RI collider system, which requires a huge accelerator complex, has so far been unique solition
to overcom the diﬃculty. We are developing a novel internal target system named SCRIT (Self-Conﬁning RI Ion
Target) in an electron storage ring to make the experiment easier with much compact experimental system.
2. Major Research Subjects
Developement of the SCRIT technology and electron scattering for unstable nuclei
3. Summary of Research Activity
Development of a novel internal target of unstable nuclei (SCRIT) in an electron storage ring for electron
scattering experiment(Wakasugi, Suda, Ito, Emoto, Nakamura, Kurita, Tamae, Noda, Shirai, Yano)
We are now developing a novel internal target system, which is to be used in an electron storage ring. This isnamed SCRIT (Self-Conﬁning Radioactive Ion Target). This technology can localize speciﬁc ions on the electron
beam axis using so-called “ion-trapping” phenomenon and form a ﬁxed target of unstable nuclei. This will realize
electron-scattering experiments for short-lived nuclei that have never been succeeded in. The R&D study of the
SCRIT is now under way at the KSR in Kyoto University. We conﬁrmed that 133 Cs ions, which were injectedfrom outside, were trapped in the SCRIT. The SCRIT technology will open a new application of electron rings.

Team Leader
Hiroyoshi SAKURAI
Members
Takashi EMOTO
Sachiko ITO
Masanori WAKASUGI- 304 -GARIS Team
1. Abstract
Development and maintenance of devices related to study of the superheavy elements.
2. Major Research Subjects(1) Maintenance and development of a recoil separator.
(2) Development of rapid chemistry devices.
3. Summary of Research Activity(1) Maintenance and development of recoil separator
A gas-ﬁlled recoil separator has been used as a main experimental device for the study of superheavy elements.
We will develop and maintain the related devices. We will also oﬀer user-support if a researcher wishes to use thedevices for his/her own research program.
(2) Development of devices for fast chemistry
We do research and development of devices for fast chemistry of superheavy elements. We also oﬀer user-support
for potential users.

Team Leader
Kosuke MORITA
Members
Hiromitsu HABA
Kouji MORIMOTO
Special Postdoctoral Researcher
Daiya KAJI
Contract Technical Scientist
Akira YONEDA
Research Associate
Hidetoshi KIKUNAGA
Junior Research Associate
Takahiro AKIYAMA (Grad. Sch. of Sci. & Eng., Saitama Univ.)- 305 -

BigRIPS Team
1. Abstract
This team is in charge of development, design and construction of BigRIPS separator and its related equipments,
which will be employed for not only the production of RI beams but also the experimental studies using RI beams
in the RI beam factory (RIBF) project.
2. Major Research Subjects
Development and construction of BigRIPS, RI-beam transport lines, and their related equipments
3. Summary of Research Activity
This team is in charge of development, design and construction of BigRIPS separator and its related equipments,
which will be employed for not only the production of RI beams but also the experimental studies using RI beams
in the RI beam factory (RIBF) project.
The research subjects may be summarized as follows:
Development, design and construction of BigRIPS separator and its related equipments such as ZeroDegree
spectrometer.
(1) General studies on RI-beam production using in-flight scheme.
(2) Studies on ion-optics of in-flight separators, including particle identification of (3) RI beams and simulationof RI-beam production.
(4) Development of beam-line detectors and their data acquisition system.
(5) Experimental studies on production reactions and unstable nuclei.
(6) Development of superconducting magnets and their helium cryogenic systems.
(7) Development of a high-power production target system.
(8) Development of a high-power beam dump system.
(9) Development of a remote maintenance and remote handling systems.
(10) Operation, maintenance and improvement of BigRIPS separator system and its related equipments suchas ZeroDegree spectrometer.

Team Leader
Hiroyoshi SAKURAI
Members
Toshiyuki KUBO
Masao OHTAKE
Yoshiyuki YANAGISAWA
Atsushi YOSHIDA
Kouichi YOSHIDA
Contract Researchers
Kensuke KUSAKA
Tetsuya OHNISHI
Research Associates
Naoki FUKUDA
Tomohito HASEYAMA
Part-time Staﬀ
Hidekazu KUMAGAI
Senior Visiting Scientist
Susumu SHIMOURA (CNS, Grad. Sch. Sci., Univ. of Tokyo)- 306 -

Computing and Network Team
1. Abstract
Development, management and operation of the computing and network environment, mail server and dataacquisition system and control of the information security of the Nishina Center for Accelerator-Based Science.
2. Major Research Subjects(1) Development, management and operation of the computing(2) Development, management and operation of the mail server(3) Development, management and operation of the data acquisition system(4) Development, management and operation of the network environment(5) Control of the information security
3. Summary of Research Activity
Development, management and operation of the computing and network environment, mail server and dataacquisition system and control of the information security of the Nishina Center for Accelerator-Based Science.
For more information, please refer to the document in this report entitled “Network and Computing Environment for RIKEN Nishina Center” written by T. Ichihara, Y. Watanabe, K. Yoshida and A. Yoshida as page 199
and also the URL http://ribf.riken.jp/comp/index-j.html.

Team Leader
Takashi ICHIHARA
MemberYasushi WATANABE- 307 -

Detector Team
1. Abstract
This team is to organize various detector developments performed at in-house laboratories and groups, in orderto improve mutual share of knowledge and experience.
2. Major Research Subjects(1) Development of delay-line PPAC
(2) Development of transmitter/receiver for fast signal transmission through optical ﬁbers
3. Summary of Research Activity
This team is now focusing on developments of delay-line PPAC and a pair of fast transmitter and receiver coupledwith optical ﬁbers for fast signal transmission. These two developments are essential for particle identiﬁcation at
BigRIPS.
(1) Delay-line PPACAt BigRIPS, a purity of radioactive isotope beams (RIBs) is as low as 10% or less at medium and heavy
mass region. Thus, development of detectors for high-rate use is one of goals in this team. With this respect,
we have developed a position-sensitive Parallel Plate Avalanche Counter (PPAC). Delay-line read-out techniqueappropriate for high-rate use is employed for position determination. This PPAC has two stripped-electrodes forboth horizontal and vertical positions, and this conﬁguration leads to high performance in terms of eﬃciency aswell as position resolution. More than ten PPACs are being installed at BigRIPS.
(2) Fast transmitter and receiver for optical ﬁber
In general co-axial metal wires are used for fast signal transmission. Instead, we have developed a special circuitof transmitter and receiver for optical ﬁber.
At a new facility of RIBF, circuits for detectors are located at several focal planes of the BigRIPS, and distances
between focal planes and counting room are as long as 100 m. To introduce optical ﬁbers in signal transmission,
we focus on a common ground at each focal plane, and easily isolate the ground levels. A problem in use of opticalﬁber was no fast transmitter/receiver with a low cost, which are not available in market. We have developed apair of fast transmitter and receiver for optical ﬁbers with a semiconductor laser and photo diode. This circuit
has a fast time response of more than 1 GHz. Attenuation of signal amplitudes is negligibly small even at a long
distance transmission of more than 100 m. Many sets of transmitter/receiver for detectors at BigRIPS have been
already manufactured, and optical ﬁbers will be used for standard transmission of signals.

Head
Hiroyoshi SAKURAI
Contract Researcher
Akira YONEDAPart time staﬀ I
Hidekazu KUMAGAI
Senior Visiting Scientist
Hirohiko SHIMIZU (Inst. of Materials Structure Sci., KEK)

- 308 -

User Support Office
1. Abstract
The RIKEN RI Beam Factory is the world preeminent facility providing the greatest opportunities for scientificresearches. It is our important mission to serve for a broad range of application of a large variety of researchers
so that we bring out the best performance of the RI Beam Factory. We manage to facilitate the use of RI
Beam Factory to the researchers both inside and outside of RIKEN, to support experiments using the accelerator
complex, to exploit industrial application researches, and to promote the RI Beam Factory to interested researchers
2. Major Research Subjects(1) Facilitation of the use of the RI Beam Factory(2) Support of experiments in the RI Beam Factory(3) Promotion of the RI Beam Factory to interested researchers
3. Summary of Research Activity
The RIKEN RI Beam Factory is the world preeminent facility providing the greatest opportunities for scientificresearches. It is our important mission to serve for a broad range of application of a large variety of researchers
so that we bring out the best performance of the RI Beam Factory. We manage to facilitate the use of RI
Beam Factory to the researchers both inside and outside of RIKEN, to support experiments using the accelerator
complex, to exploit industrial application researches, and to promote the RI Beam Factory to interested researchers

Team Leader
Toshimi SUDA
Members
Mieko KOGURE
Toshiko NAKAMURA
Technical Staﬀ I
Narumasa MIYAUCHI
Assistant
Tomoko IWANAMI
Yuri TSUBURAI- 309 -

Experimental Support Team
1. Abstract
We are supporting users of accelerators in the Nishina Center.
2. Major Research Subjects
No research.
3. Summary of Research Activity
Supporting activities are carried out for any experiments using accelerators of RILAC, AVF cyclotron, RRC
and/or RIBF accelerators.

Team Leader
Masayuki KASE
Members
Nobuhisa FUKUNISHI
Naohito INABE
Osamu KAMIGAITO
Takahide NAKAGAWA
Hiroki OKUNO
Naruhiko SAKAMOTO
Masanori WAKASUGITamaki WATANABE- 310 -

Industrial Coorperation Team
1. Abstract
The scope of the industrial cooperation team includes industrial application of RIBF facility and research anddevelopment for industrial application of accelerator associated technologies.
2. Major Research Subjects(1) Development of techniques for radioisotope production(2) Application of advanced data acquisition and signal processing technologies
3. Summary of Research Activity(1) Development of techniques for radioisotope production
At RIBF, various speciﬁc radioisotopes for research have been produced with the cyclotrons and the ion beams
generated thereby and used for various joint research projects. As we plan to distribute commercially a few
radioisotopes to nonaﬃliated users, the production techniques are being developed for stable supply and quality
level.
(2) Research and development of m-sequence modulation technique“M-sequence modulation (Takeichi et al., 2007)” enables eﬃcient acquisition and extraction of a continuous
brain-activation signal. The stimulus is modulated by a pattern deﬁned by an m-sequence. The measured brainactivation signal is then decoded by computing a cross-correlation function with the m-sequence and applying
independent component analysis. We are currently working on investigations of further developments and applications to medical and health sciences, information communication, and other basic and industrial researchﬁelds.

Team Leader
Tadashi KAMBARA
Members
Tomoko ABE
Shuichi ENOMOTO
Hiroshige TAKEICHI
Temporary Staﬀ
Ichiro SAKAMOTOPart time staﬀ
Taro YOSHIMI
ArbeitAya ISHIZUKA
Visiting Scientists
Makiko KAGA (National Inst. of Mental Health)Atsuko GUNJI (National Inst. of Mental Health)Michiteru KITAZAKI (Res. Center for Future Vehicle. Toyohashi Univ. of Tech.)Student Trainees
Yasuhisa FUJIKI (Fac. of Eng., Toyohashi Univ. of Tech.)
Shinichiro HARIYAMA (Dept. of Knowledge-based Information Eng., Toyohashi Univ. of Tech.)
Shinichi ONIMARU (Dept. of Knowledge-based Information Eng., Toyohashi Univ. of Tech.)- 311 -

Radiation Lab.
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 in physics of the strong force. The research goal of Radiation
Laboratory is to solve this fundamental question using the ﬁrst polarized-proton collider, realized at RHIC,
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 N. Samios carries our core team at BNL for those exciting researches. We are also doing
pioneering researches at the domestic accelerators at RIKEN and High Energy Accelerator Research Organization(KEK). We have recently discovered mass modiﬁcation of vector meson using the accelerator at KEK. We arealso performing technical developments such as novel ion sources, super conducting detectors, ﬁne pitch pixel
detectors and neutron optical devices.
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: RIKEN-BNL Research Center Experimental Group (Heavy Ion Basic Science - Study of Spin Physics
Using RHIC)](2) Experimental study of quark-gluon plasma RHIC heavy ion collider[See: RIKEN-BNL Research Center Experimental Group (Heavy Ion Basic Science - Study of Spin Physics
Using RHIC)](3) Study of nuclear medium eﬀect on vector mesons at KEK-PS
The experiment KEK-PS E325 was performed from 1997 to 2002. We measure invariant mass spectra of e+ e−
and K+ K− channels using 12-GeV proton + nucleus reactions, and investigate the spectral modiﬁcation of vector
mesons (ϕ, ρ and ω) which is theoretically expected due to the chiral symmetry restoration. Through the analyses
until this year, we have conﬁrmed that those three mesons are modiﬁed in nuclear matter. Especially the spectral
modiﬁcation of the ϕ meson is observed for the ﬁrst time and is very important. We have press-released theresults just after the acceptance of the paper by Physical Review Letters. The paper was also cited in PhysicalReview Focus.
(4) Study of Accelerator and Ion source
To achieve highly polarized beams in RHIC it is necessary to understand the AGS (RHIC injector synchrotron)
spin dynamics. The normal-conducting partial-snake magnet, which we have developed for AGS years ago, now
playing a more important role with the other super-conducting snake magnet, newly fabricated and installed in
AGS. Several combinations of ﬁeld strengths of these two magnets have been tried to achieve more sophisticatedoperation. We are also studying betatron tunes for the two snake conﬁguration and we have currently achieved the
AGS polarization of 65%. For future high-brightness heavy-ion accelerators, we are studying high current beam
production using a new strategy called direct plasma injection scheme. Our world intensity record of Carbon
beam production was followed by a record Aluminum beam which showed more than 70 mA. We have also proventhe feasibility of high intensity beam production from cryo-cooled gas target.
(5) Detector development for PHENIX experiment
To improve the physics capability of the PHENIX detector system at RHIC, we are developing the silicon vertex
detector (VTX). The VTX consists of two layers of silicon pixel detectors developed under the collaboration with
CERN, and other two layer of silicon strip detector with BNL. RIKEN Radiation Laboratory is responsible forthe ladder fabrication of the pixel detector and the sensor fabrication of strip detector. The ﬁrstly assembled
prototype ladders were tested with cosmic rays and successfully operated through the PHENIX-equivalent dataacquisition system. For the ﬁnal product we are developing high-density ultra-thin ﬂexible print board, andpreparing for the mass production assembling with 10 µm accuracy.
(6) Research and development of superconductor radiation detectors
Superconductor radiation detectors are able to measure the energies of photons with a much better resolution
than any type of conventional detectors. They are capable of detecting photons over a wide energy range and also

- 312 -

charged particles. We have been developing superconducting tunnel junctions (STJs) as high-resolution radiation
detectors. This year, an anodization method was introduced in fabricating STJs with a large area (500 µm ×
500 µm) in order to reduce leakage current. We got eight STJs with reasonable uniformity. Using these new STJs,
we have started a new experiment to measure neutron beta decays at Japan Atomic Energy Agency. New idea
to prevent phonon events in STJ was tried in collaboration with Saitama University. We made new STJs whichhave polyimide buﬀer layer and found that such layers are eﬀective to reduced phonon events.
(7) Neutron optics
Cold or thermal neutron beam is a high-sensitivity probe to study the structure of light elements such ashydrogen in any kind of material, including bio-molecules. However, its realistic applications are still limited since
the numbers of available neutron sources are small and their intensities are low. This project aims to enhancethe eﬃciency in using those precious neutron beams by improving the neutron beam optics, in order to maximize
scientiﬁc outputs within a short period of time. This year an ellipsoidal neutron mirror and a new neutron detector
with a good spatial resolution are developed for mfSANS (Mini Focusing Small Angle Neutron Scattering). We
have tested the prototype of this system at LINAC in Hokkaido University. We successfully measured the neutron
diﬀractions down to the momentum transfer region of Q < 2 × 10−3 A−1 . We also developed “one-dimensional
multi-channel neutron bender” as a neutron focusing device, whose ﬁrst test was successfully performed at Tokyo
University. To transfer these new technologies to public use, we have founded “Riken Venture Company”, Japan
Neutron Optics Inc. which has already started to distribute its products to other laboratories and universities.
(8) Theoretical study of hadron physics
We performed an analysis of fragmentation functions of mesons and baryons, which is the ﬁrst global analysis
of fragmentation functions ﬁtted to the electron-proton data at HERA as well as the electron-positron data at
LEP. The results are important for the measurement of gluon polarization in single pion productions at RHIC.
The calculations of NLO QCD corrections are on-going for di-hadron productions in polarized hadronic processes,
which provide us with an alternative way of accessing the gluon polarization.
The double transverse-spin asymmetries in transversely polarized Drell-Yan process are calculated at the smalltransverse momentum of dilepton (“peak region”). The soft gluon eﬀects, relevant in the peak region are resummed
to all orders of perturbation. We found that the asymmetries are ﬂat and larger at the peak region than theasymmetries in the integrated cross section. We derived an asymptotic formula of the asymmetries in this region
which enable us to extract the transversity easily from the experimental data of this process.
The QED structure functions of electron are calculated up to 5th order of the coupling constant. The obtained
analytic formula is useful when we estimate the initial state radiation precisely in electron-positron, or electronproton collisions.
NLO QCD corrections to Higgs boson production through vector boson fusion processes at LHC are calculated.
The corrections turned out to be about 10% of LO result, improving the scale uncertainty signiﬁcantly. Numericalstudies with various experimental cuts are also performed.

Head
Hideto EN’YO
Members
Yasuyuki AKIBA
Yuji GOTO
Itaru NAKAGAWA
Yoshie OTAKE
Hiromi SATO
Atsushi TAKETANI
Yasushi WATANABE
Special Postdoctoral Researchers
Junkichi ASAI
Yoshinori FUKAO
Kenji MISHIMA
Megumi NARUKI
Contract Researchers
Katsuya HIROTA
Ryo ICHIMIYA- 313 -

Kazuaki IKEDA
Soichiro KAMETANI
Hiroyuki KAWAMURA
Takahiro MORISHIMA
Ryotaro MUTO
Hiromi OKADA
Yoshiyuki ONUKI
Vladimir Rykov
Marco Stratmann
Tsuguchika TABARU
Satoshi YOKKAICHI
Contract Technical Scientists
Maki KUROSAWA
Part-time Staﬀ (Research support)
Hiroyuki KANO
Senior Visiting Scientists
Ken-ichi IMAI (Grad. Sch. of Sci., Kyoto Univ.)
Toshiaki SHIBATA (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech. Sch. of Sci.)
Hirohiko SHIMIZU (Inst. of Materials Structure Sci., KEK)
Koichi YAZAKI (Tokyo Woman’s Christian Univ.)
Visiting Scientists
Tomohiro ADACHI (DAI-ICHI KIDEN CO.,LTD)
Christine A. AIDALA (Univ. Massachusetts, Amherst, USA)
Hiroshi AKOH (National Inst. of Advanced Industrial Sci. and Tech.)
Masahiro AOYAGI (National Inst. of Advanced Industrial Sci. and Tech.)
Masayuki ASAKAWA (Grad. Sch. of Sci., Osaka Univ.)
Alexander Bazilevsky (BNL, USA)
Wolfgang BENTZ (Tokai Univ.)
Mickey Chiu (Univ. of Illinois at Urbana, USA)
Seishi DAIRAKU (Grad. Sch. of Sci., Kyoto Univ.)
Sanatan Digal (Grad. Sch. of Sci., Univ. of Tokyo)
Frank ELLINGHAUS (Univ. of Colorado, USA)
Waled EMAM (Univ. of California at Riverside, USA)
Hirotsugu FUJII (Grad. Sch./College of Arts and Sciences, Univ. of Tokyo)
Haruhiko FUNAHASHI (Grad. Sch. of Sci., Kyoto Univ.)
Xiaohong GUO (Inst. Modern Phys. Chinese Acad. Sci., China)
Tetsuo HATSUDA (Grad. Sch. of Sci., Univ. of Tokyo)
Toshiyuki HATTORI (Res. Lab. for Nuclear Reactors, Tokyo Inst. of Tech. Sch. of Sci.)
Noriyosu HAYASHIZAKI (Res. Lab. for Nuclear Reactors, Tokyo Inst. of Tech. Sch. of Sci.)
Masanori HIRAI (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech. Sch. of Sci.)
Kensuke HONMA (Grad. Sch. of Sci., Hiroshima Univ.)
Takuma HORAGUCHI (Grad. Sch. of Sci., Hiroshima Univ.)
Alekseev IGOR (ITEP, Russia)
Katsuya ISHIGURO (Grad. Sch. of Natural Sci. & Tech., Kanazawa Univ.)
Noriyoshi ISHII (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech. Sch. of Sci.)
Barbara Jager (Univ. Karlsruhe, Inst. Theoretical Phys., Germany)
Robert Jameson (Goethe Universitat Frankfurt, Germany)
Osamu JINNOUCHI (Inst. of Particle and Nucl. Studies, KEK)
Masashi KANETA (Grad. Sch. of Sci., Tohoku Univ.)
Hirotsugu KASHIWAGI (Takasaki Advanced Radiation Res. Inst., JAEA)
Yuji KAWABATA (Kyoto Univ. Res. Reactor Inst.)
Takeo KAWASAKI (Grad. Sch. of Sci. and Tech., Niigata Univ.)
Akio KIYOMICHI (J-PARC, JAEA)
Jiro KODAIRA (Grad. Sch. of Sci., Hiroshima Univ.)
Yuji KOIKE (Grad. Sch. of Sci. & Tech., Niigata Univ.)
Sergei KONDRASHEV (ITEP, Russia)
Dmitiri KOTCHETKOV (Univ. New Mexico, USA)- 314 -

Shunzo KUMANO (Inst. of Particle and Nuclear Studies, KEK)
Teiji KUNIHIRO (Yukawa Inst. for Theoretical Phys., Kyoto Univ.)
Masahiko KURAKADO (Academic Frontier Promotion Center, Osaka Electro-Communication
Univ.)
Ming XIONG LIU (Los Alamos Nat. Lab., USA)
Keisuke MAEHATA (Fac. of Eng., Kyushu Univ.)
Yajun MAO (Peking Univ., China)
Yasuo MIAKE (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba)
Shoichi MIDORIKAWA (Fac. of Software and Information Tech., Aomori Univ.)
Osamu MORIMATSU (Inst. of Particle and Nuclear Studies, KEK)
Hiroaki MYOREN (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Sachio NAITO (Inst. of Materials Structure Sci., KEK)
Hiroshi NAKAGAWA (National Inst. of Advanced Industrial Sci. and Tech.)
Yoshifumi NAKAMURA (DESY, Germany)
Atsushi NAKAMURA (Information Media Center, Hiroshima Univ.)
Masashi OHNO (Sch. of Eng., Univ. of Tokyo)
Munehisa OHTANI (Inst. fuer Theoretische Physik, Universitact Regensburg, Germany)
Masahiro OKAMURA (BNL, USA)
Petra RIEDLER (CERN, Switzerland)
Koichi SAITO (Tokyo Univ. of Sci.)
Takuya SAITO (RCNP, Osaka Univ.)
Naohito SAITO (J-PARC, KEK)
Kenji SASAKI (Inst. of Particle and Nuclear Studies, KEK)
Shin-ya SAWADA (Inst. of Particle and Nuclear Studies, KEK)
Michiko SEKIMOTO (Inst. of Particle and Nuclear Studies, KEK)
Kenta SHIGAKI (Grad. Sch. of Sci., Hiroshima Univ.)
Shigetomo SHIKI (Academic Frontier Promotion Center, Osaka Electro-Communication Univ.)
Tatsushi SHIMA (RCNP, Osaka Univ.)
Takenao SHINOHARA (Advanced Sci. Res. Center, JAEA)
Kazutaka SUDO (Inst. of Particle and Nuclear Studies, KEK)
Toru SUGITATE (Grad. Sch. of Sci., Hiroshima Univ.)
Tsuneo SUZUKI (Grad. Sch. of Natural Sci. & Tech., Kanazawa Univ.)
Junichi SUZUKI (Advanced Sci. Res. Center, JAEA)
Dmitry SVIRIDA (ITEP, Russia)
Toru TAINO (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Manobu TANAKA (Inst. of Particle and Nuclear Studies, KEK)
Kiyoshi TANIDA (Grad. Sch. of Sci., Kyoto Univ.)
Kazuo TANIGUCHI (Fac. of Eng., Osaka Electro-Communication Univ.)
Alexander TITOV (Flerov Lab. Nucl. Reactions, Joint Inst. Nucl. Res., Russia)
Manabu TOGAWA (Grad. Sch. of Sci., Kyoto Univ.)
Hisayuki TORII (Grad. Sch. of Sci., Hiroshima Univ.)
Xiaorong WANG (New Mexico State Univ., USA)
Satoru YAMADA (Advanced Sci. Res. Center, JAEA)
Yoshiaki YASUI (Tokyo Management College)
Imuran YOUNUS (Univ. of New Mexico, USA)
Students
Junior Research Associate
Kazuya AOKI (Grad. Sch. of Sci., Kyoto Univ.)
Kohei FUJIWARA (Grad. Sch. of Sciences & Tech., Niigata Univ.)
Tadaaki ISOBE (CNS, Grad. Sch. of Sci., Univ. of Tokyo)
Fukutaro KAJIHARA (CNS, Grad. Sch. of Sci., Univ. of Tokyo)
Kenichi NAKANO (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech. Sch. of Sci.)
Yoshichika SEKI (Grad. Sch. of Sci., Kyoto Univ.)
Kohei SHOJI (Grad. Sch. of Sci., Kyoto Univ.)
Junpei TAKANO (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech. Sch. of Sci.)
Yuji TSUCHIMOTO (Grad. Sch. of Sci., Hiroshima Univ.)
Part-time Staﬀ (Research support)
Kohichi SAKASHITA (Tokyo Inst. of Tech. Sch. of Sci.)- 315 -

Fuminori SAKUMA (Grad. Sch. of Sci., Kyoto Univ.)
Yoshihiro YAMAMOTO (The Univ. of Electro-Communications)Part-time Staﬀ (Research assistant)
Jun TAMURA (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech. Sch. of Sci.)
InternYuki MIYAMOTO (Tokyo Metropolitan College of aeronautical Eng.)
Joseph SEELE (Dept. Phys., Univ. of Colorado, USA)
Tsutomu WAKABAYASHI (Tokyo Metropolitan College of aeronautical Eng.)
Zhengyun You (Peking Univ., China)
Takeshi KANESUE (Fac. of Eng., Kyushu Univ.)
Student Trainees
Kazutaka AOKI (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Hisato EGUCHI (Grad. Sch. of Sci. & Tech., Niigata Univ.)
Yusuke FUJISAWA (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Masatoshi HAMADA (Fac. of Sci., Kyushu Univ.)
Masayasu HASEGAWA (Grad. Sch. of Natural Sci. & Tech., Kanazawa Univ.)
Hirokazu ISHII (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Taku ITO (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech. Sch. of Sci.)
Hiroki KANOH (Grad. Sch. of Sci. and Eng., Tokyo Inst. of Tech.)
Kenichi KARATSU (Grad. Sch. of Sci., Kyoto Univ.)
Motohiro KAWASHIMA (College of Sci., Rikkyo Univ.)
Kotaro KIJIMA (Grad. Sch. of Sci., Hiroshima Univ.)
Masahiro KONNO (Grad. Sch. of Pure and Applied Sciences, Univ. of Tsukuba)
Martin LEITGAB (Univ. Vienna, Austria)
Kouichi MATSUBARA (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Kentaro MIKI (Grad. Sch. of Pure and Applied Sciences, Univ. of Tsukuba)
Koji MIWA (Grad. Sch. of Sci., Kyoto Univ.)
Shinji MOTOKI (Grad. Sch. of Biosphere Sci., Hiroshima Univ.)
Takahiro NAGAI (Sch. of High Energy Accelerator Sci., The Grad. Univ. for Advanced Studies)
Yoshihide NAKAMIYA (Grad. Sch. of Sci., Hiroshima Univ.)
Tomoaki NAKAMURA (Grad. Sch. of Sci., Hiroshima Univ.)
Misaki OUCHIDA (Grad. Sch. of Sci., Hiroshima Univ.)
Akikuni SATO (Grad. Sch. of Sci., Kyoto Univ.)
Toru SEKIDO (Grad. Sch. of Natural Sci. & Tech., Kanazawa Univ.)
Katsuyuki SENZAKA (Grad. Sch. of Sci., Kyoto Univ.)
Yosuke SERITA (Grad. Sch. of Sci. & Eng., Saitama Univ.)
Maya SHIMOMURA (National Inst. of Advanced Industrial Sci. and Tech.)Jonathan Turner (Univ. of New Mexico, USA)
Satoru UEDA (Grad. Sch. of Pure and Applied Sciences, Univ. of Tsukuba)
Secretaries
Hitomi KANEHAMA
Noriko KIYAMAMichiko MUROI- 316 -

Advanced Meson Science Laboratory
1. Abstract
Particles like muon, pion, and kaon have ﬁnite life time. Implanting these particles into materials, varieties ofobjects are studied from new points of views. For instance, stopping positively charged muon in a material, we
obtain information on the magnetic properties or the local ﬁeld at the trapped site. Injecting negatively charged
muon to mixture of deuterium and tritium, muon attracts surrounding atoms and is known to cause d-t fusions.
We are also proceeding studies with other meta-stable particles other than muons. Kaon is a meson which has
strange quark as its composition, and introducing Kaons into nuclei, sizes of the nuclei are estimated to become
smaller and the density larger. We are studying this subject by performing experiments. Also, producing Lambda
particles from the Kaons and observing its decay, we obtain information on the weak interaction between two
baryons which is usually hidden. We also study properties of nuclei in detail by making spectroscopy of pions
bound to nuclei.
As is already clear, in our research we introduce diﬀerent kind of impurites into objects, and study new statesof matter, new phenomena, or the object properties.
2. Major Research Subjects(1) Nuclear physics via muon catalyzed fusion and muonic atoms(2) Condensed matter and material studies with muon(3) Study of meson property inside nuclei(4) Interaction between meson and nuclei
3. Summary of Research Activity
Meta-stable particles such as muon, pion and kaon have opened variety of scientiﬁc research areas. Especially,muon plays an important role. The research area ranges over particle physics to condensed matter studies and life
science. Our core activities are based on the RIKEN-RAL Muon Facility located at the Rutherford Appleton Laboratory (UK), which provides the most intense pulsed muon beam. We have variety of important research activities
such as muon-catalyzed fusion (µCF) and condensed matter physics by muon spin rotation/relaxation/resonance(µSR). On the other hand, pion and kaon shed a new insight to the nuclear physics. The recent discovery ofdeeply bound pionic state enables us to investigate the properties of mesons in nuclear matter. We aim to be aworld-leading scientiﬁc research group using these light meta-stable particles.
(1) Condensed matter/materials studies with high energy accelerator producing particles and nuclei
There are three topics of material sciences studied by the muon-spin relaxation method at the RIKEN-RAL
Muon facility in 2007.
1) From measurements of the muon-spin depolarization rate in magnetic ﬁelds, quantitative values of thetransition rate of electrons between iron atoms in a ironmetal complexes have been ﬁrstly obtained.
2) In a Sm-based Ru-Fe skutterudite compound, a possibility of the appearance of an ordered state of a multipole moments has been pointed out.
3) A new condensed state of excited electronic states has been suggested in Tl-K quantum-spin systems fromzero-ﬁeld muon-spin relaxation method.
(2) Nuclear physics studies with muons, such as muon catalyzed fusion and muonic atoms
1) Muon catalyzed fusion (µCF)
We are studying the muon catalyzed fusion (µCF) processes in a wide range of hydrogen target conditions suchas isotope mixtures and temperatures. This year, we studied the eﬀect of ortho-para composition of D2 molecules.
The ddµ formation rate in pure gaseous deuterium target at 35 K was increased when we used ortho-rich D2 ,while it was opposite with liquid target even at the same temperature. For the liquid D2 /T2 mixture, we achieved
the increase of dtµ formation by using ortho-D2 for the ﬁrst time.
2) Development towards muonic atom formation with unstable nuclei
Stopping negative muons in the solid hydrogen with implanted unstable atoms, muons transfer eﬃciently tothe implanted nuclei from muonic hydrogen to form the muonic atoms. By observing muonic X-rays at muonic
atom formations, fundamental experiments on the nuclear charge density distribution are in progress. The surface
ionization ion source was installed in the experimental apparatus to produce alkaline ion beams, and carried out
successfully the ﬁrst experiment to measure an isotope energy shift of muonic X-rays originated from muonic 88 Sr
and 86 Sr atoms.
3) Generation of ultra slow positive muon beam
We have constructed a new µSR spectrometer specialized for using low energy muon beam, whose kinetic- 317 -

energy is variable from a few keV to a few tens of keV. This will extend the scope of µSR technique from a bulk
material to surfaces and multi-layered materials. In order to demonstrate the new spectrometer’s capability, we
have carried out the ﬁrst µSR experiment of a thin ﬁlm of a perovskite-type manganese oxide, and successfully
observed changes in spectra’s shape which are associated to phase transitions.
(3) Study of deeply bound mesonic nuclei
1) Deeply bound kaonic nuclei
We have performed a high precision and small ambiguity spectroscopy on the mass of the strange tribaryon -S◦(3115)-at the high energy accelerator research organization (KEK). We measured the momenta of protons emitted
in the reaction between negatively charged K mesons and helium nuclei. Compared to the previous experiment,
the mass resolution was improved by a factor of 2 and the statistical accuracy by a factor of about 10. We
have newly installed detectors exclusively used for the measurement of the protons and realized small-ambiguity
experiment. As a result, no structure was observed, in the spectrum, associated to the strange tribaryon with thenatural width of 20 MeV/c2 , and the result was contradictory to the previous experiment. Statistical evaluation
tells that the previous results are rejected by a conﬁdence level of 99%. Theoretical studies are ﬁrmly predicting
the existence of the strange tribaryon or states where K meson is deeply bound to helium nucleus. We need tocontinue further analysis of the experimental data investigating the possible existence of structures with larger
widths. Especially, the experiment described below(3) is important in terms of the constraints set strongly to theexistence of the deeply bound k states.
2) Deeply bound pionic and eta- nuclei
We made a spectroscopy experiment to measure deeply bound pionic states in several tin isotopes at the GSI,
Germany, to investigate the pion-nucleus strong interaction. The results provided information on the iso-vector
part of the strong interaction between pion and nucleus. More advanced discussion leads to the origin of the massof matter, which is attributed to the quark condensation in the vacuum. Presently we are analyzing the data of
eta-mesonic nuclei, and willing to extend our study to the heavier meson.
3) Precision X-ray measurement of kaonic atom
Simultaneously with the above experiment(1), we have performed an X-ray spectroscopy of atomic 3d → 2ptransition of negatively charged K mesons captured by helium atoms. Many kaonic atoms are known to bemeasured with various elements, however, there are very large deviations in the measured energy levels for the
helium (and the oxygen) from the systematic expectations. The deviation may originate in technical issues in old
experiments, and new and high precision data have been long awaited for. Also, the wave functions of the kaonicatoms are expected to reﬂect the information on the existence of the inner structure, namely strange tribaryon
or deeply bound kaonic states. As a result of the experiment, we have succeeded in performing the spectroscopy
and achieved <10 eV (σ) in the experimental resolution, which is by far improved from older experiments. The
obtained results reject older data beyond any doubt, and the above deviation is dissolved. Presently, aiming at
higher precision, we are proceeding the data analysis.

Head
Masahiko IWASAKIMembers
Katsuhiko ISHIDA
Kenta ITAHASHI
Yasuyuki MATSUDA
Teiichiro MATSUZAKI
Hiroaki ONISHI
Haruhiko OUTA
Isao WATANABE
Special Postdoctoral Researchers
Hidekatsu NEMURA
Shinji OKADA
Takatoshi SUZUKI
Dai TOMONO
Special Contract Researchers
Masami IIO
Takahisa KOIKE- 318 -

Contract Researchers
Pavel BAKULE
Takayuki KAWAMATA
Seiko KAWAMURA
Takao SUZUKI
Visiting Scientists
Tadashi ADACHI (Grad. Sch. Eng., Tohoku Univ.)
Yoshitami AJIRO (Grad. Sch. Sci., Kyoto Univ.)
Jun AKIMITSU (Coll. Sci. Eng., Aoyama Gakuin Univ.)
Jūichirou ARAI (Fac. Sci., Tokyo Univ. Sci.)
Shingo ARAKI (Grad. Sch. Sci., Osaka Univ.)
Kunio AWAGA (Grad. Sch. Sci., Nagoya Univ.)
George BEER (Univ. of Victoria, Canada)HyoungChan BHANG (Seoul National Univ., Korea)
N. Ludmila BOGDANOVA (ITEP, Russia)
Prasad Tara DAS (SUNY at Albany, USA)
Masaya ENOMOTO (Grad. Sch. Arts and Sci., Univ of Tokyo)
Mark FAYFMAN (Kurchatov Inst., Russia)
Yutaka FUJII (Fac. Eng., Fukui Univ.)
Masaki FUJITA (IMR, Tohoku Univ.)
Hideto FUKAZAWA (Grad. Sch. Sci. & Tech., Chiba Univ.)
Takayuki GOTO (Fac. Sci. & Tech., Sophia Univ.)
Makoto HAGIWARA (Fac. Eng. Design, Kyoto Inst. Technol.)
Ryugo HAYANO (Grad. Sch. Sci., Univ. of Tokyo)
Wataru HIGEMOTO (JAEA)
Masahiro HIRANO (JST)
Kazuto HIRATA (NIMS)
Emiko HIYAMA (Fac. Sci., Nara Women’s Univ.)
Susumu IKEDA (KEK)
Yutaka IKEDO (Toyota Central R&D Labs.)
Fumihiro ISHIKAWA (Grad. Sch. Sci. & Tech., Niigata Univ.)
Shigeru ISHIMOTO (KEK)
Tomoichi ISHIWATARI (SMI, Austria)
Ryosuke KADONO (KEK)
Mineo KATO (JAEA)
Naritoshi KAWAMURA (KEK)
Jungho KIM (Seoul National Univ., Korea)
Yasushi KINO (Fac. Sci., Tohoku Univ.)
Akihiro KODA (KEK)Yoh KOHORI (Fac. Sci., Chiba Univ.)
Yoji KOIKE (Grad. Sch. Eng., Tohoku Univ.)
Yoshitaka KUNO (Grad. Sch. Sci., Osaka Univ.)
Chow LEE (UCF, USA)
Shunsuke MAKIMURA (KEK)
Goro MARUTA (Grad. Sch. Sci., Hokkaido Univ.)
Satoru MATSUISHI (FCRC, Tokyo Tech.)
Yasuhiro MIYAKE (KEK)
Hitoshi MIYASAKA (Grad. Sch. Sci., Tohoku Univ.)
Soichiro MIZUSAKI (Coll. Sci. & Eng., Aoyama Gakuin Univ.)
Kazuhiko MUKAI (Toyota Central R&D Labs.)
Kazutaka NAKAHARA (KEK)
Takashi NAKAMURA (Grad. Sch. Sci. & Eng., Tokyo Tech.)Takayoshi NAKAMURA (RIES, Hokkaido Univ.)
Satoshi NAKAMURA (Grad. Sch. Sci., Tohoku Univ.)
Takehito NAKANO (Grad. Sch. Sci., Osaka Univ.)
Nobuhiko NISHIDA (Fac. Sci., Tokyo Tech.)
Kusuo NISHIYAMA (KEK)
Hiroshi NOZAKI (Toyota Central R&D Labs.)
Yasuo NOZUE (Grad. Sch. Sci., Osaka Univ.)- 319 -

Masaaki OHBA (Grad. Sch. Eng., Kyoto Univ.)
Susumu OHYA (Fac. Sci., Niigata Univ.)
Akira OSAWA (Fac. Sci. & Tech., Sophia Univ.)
Vassili PEREVOZCHIKO (VNIEF, Russia)
Leonid PONOMAREV (Kurchatov Inst., Russia)
Francis PRATT (RAL, UK)
Shin-ichi SAKAMOTO (JAEA)
Ryoichi SEKI (California State Univ., Northridge, USA)
Kouichiro SHIMOMURA (KEK)
Vyacheslas STORCHAK (Kurchatov Inst., Russia)
Patrick STRASSER (KEK)
Hiroyuki SUGAI (JAEA)
Jun SUGIYAMA (Toyota Central R&D Labs.)
Haruhiko SUZUKI (Grad. Sch. Nat. Sic. & Tech., Kanazawa Univ.)
Hiroyuki SUZUKI (NIMS)
Kazuyuki TAKAI (Grad. Sch. Sci. & Eng., Tokyo Tech.)
Keiji TAKEDA (ISSP, Univ. of Tokyo)
Hiroyuki TAKEYA (NIMS)
Manobu TANAKA (KEK)
Akihiro TANIGUCHI (KURRI, Kyoto Univ.)
Takashi TANIGUCHI (Coll. Sci. & Eng., Aoyama Gakuin Univ.)
Eiko TORIKAI (Grad. Sch. Medicine & Eng. Sci., Univ. of Yamanashi)
Akihisa TOYODA (KEK)
Kazuo UEDA (ISSP, Univ. of Tokyo)
Yun XUE (Grad. Sch. Nat. Sic. & Tech., Kanazawa Univ.)
Kazuyoshi YAMADA (IMR, Tohoku Univ.)
Arkady YUKHINCHUK (VNIIEF, Russia)
Johann ZMESKAL (SMI, Austria)
Research Consultants
Yoshinori AKAISHI
Masayasu KAMIMURA
Atsuko ITOStudents
Junior Research Associates
Kenichi HACHITANI (Grad. Sch. Sci. & Tech., Chiba Univ.)
Masaharu SATO (Grad. Sch. Sci. & Eng., Tokyo Tech.)Student Trainees
Truong Cong DUAN (Grad. Sch. Sci., Osaka Univ.)
Hiroyuki FUJIOKA (Grad. Sch. Sci., Univ. of Tokyo)
Yoshiyuki FUKUDA (Grad. Sch. Sci. & Eng., Tokyo Tech.)Toshio HANAKI (Grad. Sch. Fac. Sci. & Tech., Tokyo Univ. Sci.)
Yuzo HIRAYAMA (Grad. Sch. Sci. & Eng., Tokyo Tech.)Takashi ITO (Grad. Sch. Sci. & Eng., Tokyo Tech.)
Satoshi ITOH (Grad. Sch. Sci., Univ. of Tokyo)
Keishi KANADA (Grad. Sch. Sci. & Tech., Sophia Univ.)
Wakako KANEKO (Grad. Sch. Eng., Kyoto Univ.)
Hirokazu KAWASHIMA (Grad. Sch. Sci. & Eng., Aoyama Gakuin Univ.)
Noriyuki KIDA (Grad. Sch. Arts and Sci., Univ. of Tokyo)
Mijung KIM (Seoul National Univ., Korea)
Yoshihiro KUBOTA (Grad. Sch. Sci., Tohoku Univ.)
Sougo KUROIWA (Grad. Sch. Sci. & Eng., Aoyama Gakuin Univ.)
Jun MATSUMOTO (Grad. Sch. Sci., Osaka Univ.)
Hayato MOCHIZUKI (Grad. Sch. Sci. & Tech., Niigata Univ.)
Yoshifumi NAGASAKI (Grad. Sch. Fac. Sci., Kanazawa Univ.)
Keisuke OMORI (Grad. Sch. Eng., Tohoku Univ.)
ROGER PINK (SUNY at Albany, USA)
Ayumi SAITO (Grad. Sch. Sci., Tokyo Metro Univ.)- 320 -

Takehiro SAITO (Grad. Sch. Sci. & Tech., Sophia Univ.)
Katsunori TAKAHARA (Inter. Grad. Sch. of Sci. & Eng., Tokyo Tech.)
Yoichi TANABE (Grad. Sch. Eng., Tohoku Univ.)
Hideyuki TATSUNO (Grad. Sch. Sci., Univ. of Tokyo)
Yoshitake TODA (Inter. Grad. Sch. of Sci. & Eng., Tokyo Tech.)
Yoko TOMITA (Grad. Sch. Sci. & Eng., Aoyama Gakuin Univ.)
Fumiko YAMADA (Grad. Sch. Sci. & Eng., Tokyo Tech.)Heejoong YIM (Seoul National Univ., Korea)
Secretaries
Yoko FUJITA
Mitsuko SUGIURA
Yuka TAKANO- 321 -

Theoretical Physics Laboratory
1. Abstract
The aim of this laboratory is to reveal the laws of nature ranging from elementary particles to the universe.
More precisely, the following three issues are pursued with their mutual relations emphasized:(1) Understanding
the microscopic fundamental law of nature. In particular, trying to give a consistent deﬁnition of superstring
and derive all the fundamental laws from one principle. (2) Understanding many-body systems. Both of thefollowing two aspects are considered. One is the universal laws such as thermodynamics and the universality ofspin systems, and the other is speciﬁc properties of individual systems such as hadrons, condensed matter, and theuniverse. (3) Computational science. Besides numerical analyses as an important tool for the above mentioned(1) and (2), aspects of fundamental mathematics are also pursued.
2. Major Research Subjects(1) Constructive Deﬁnition of String Theory as Fundamental law of Physics(2) Fundamental aspects of Quantum Field Theory and its applications(3) High precision inspection of experimental and observational data
3. Summary of Research Activity
The ability to understand nature at its most profound level is a basic human desire. Science is founded on
accumulated and tremendous eﬀorts driven by that aspiration. The objective of our laboratory is to participate
in the endeavor to better understand nature by adding our contributions to theoretical physics. The present
seems to be a particularly exciting time for this as many developments appear to be about to converge and allow
formation of the ultimate theory of everything.
We organize our research activities into three segments: the pursuit of the microscopic fundamental laws ofphysics, the study of many-body systems, and the science and technology of computation. These three aspects
have an inseparable interrelation and are investigated in an integrated manner throughout the research conductedwithin this laboratory.
(1) Understanding the fundamental law of nature through string theory.
1) Non-perturbative eﬀect for non-critical string
The analysis of the nonperturbative eﬀect in the c=0 noncritical string theory deﬁned by the one-matrix modelis extended to the case of two-matrix models which provide nonperturbative deﬁnitions of c¡1 noncritical string
theories. Then, universality of nonperturbative eﬀects including their coeﬃcients in a generic c<1 noncriticalstring theory is achieved in the sense that they are independent of details of potentials of the two-matrix models.
2) Matrix models and curved space-time
Incorporating curved space time into matrix models is pursued. In particular, a method in which larger
additional degrees of freedom is introduced to represent space-time symmetry, is proposed.
3) Domain Wall in string theory
We investigate a global structure of the moduli space of the BPS domain wall system. I particular, we areinterested in the case where the dimensions of the moduli space is greater than those expected from the index
theorem. We also study the T-duality between the vortices and domain walls from a string theoretical point ofview. We explicitly construct a vortex solution in the Higgs phase of supersymmetric gauge theory and ﬁnd an
exact correspondence between the solution and D-brane conﬁguration in the domain wall side.
4) Non BPS branes and supergravity
We investigate the correspondences between a class of classical solutions of Type II supergravity (the threeparameter solution) and D-branes in the superstring theory. In addition to the mass, the RR-charge, the solution
also carries the so-called dilaton charge, whose physical meaning was unclear. We ﬁnd that the appearance ofthe dilaton charge is a consequence of deformations of the boundary condition from that of the boundary statefor BPS D-branes. We also show that such deformed boundary states are realized as tachyonic and/or massive
excitations of the open strings on D-brane systems.
5) D-branes and instantons
We have investigated instantons of four-dimensional SUSY gauge theory from the view point of superstring
theory. A general prescription to construct the instanton solutions is known as the ADHM (Atiyah-DrinfeldHitchin-Manin) construction. In terms of superstring theory, instanton is understood as a bound state of D3branes and D (-1)-branes. We consider a system of D3-branes and anti-D3-branes to construct the bound state via
a tachyon condensation. As a result, we found that the tachyon proﬁle contains all information on the instantonand the ADHM construction can be understood as an outcome of the gauge equivalence of this system in the low- 322 -

energy limit. We also applied the same method to eight-dimensional gauge theory and showed that some solitonic
solution of the eight-dimensional theory can be constructed by this method.
6) Application of string theory to cosmology
Cosmological scenarios alternative to inﬂation motivated by string theories are known. In cyclic scenario, or
ekpyrotic scenario, the universe is considered as branes sitting in higher dimensional space time. The universe
is assumed to start out from a static Minkowskian space-time and experience the big-bang as the collision ofpair of branes (bounce). From the observational point of view, it is of importance to study the time evolutionof cosmological ﬂuctuation through the time of big bang. We studied the problem from the point of view of
local causality through the bounce. Assuming the local causality condition, we derived the most general matchingcondition for the ﬂuctuation between before and after the bounce. Especially, we found it is impossible to generate
scale invariant spectrum without introducing non-local causality throughout the bounce. This work made clear
the physical problem to obtain the scale invariant spectrum in the bouncing cosmology. We have also studied a
toy model inspired by a low-energy eﬀective action of non-commutative ﬁeld theory and estimated the range ofparameters to obtain scale invariant spectrum.
Another subject pursued was the possibility of obtaining inﬂation due to the modiﬁcation of the dispersion
relation. When non-equilibrium dynamics is taken into account, we observed that the inﬂation can be easily
realized when the energy is a decreasing function of the momentum in high-energy regime. This result provides
alternative way of realizing inﬂation in the framework of uniﬁed theory.
(2) Quantum ﬁeld theory and physics of many body systems
1) Lattice formulation of supersymmetric gauge theory
We proposed a lattice formulation of low dimensional supersymmetric gauge theories, aiming at practicalimplementation for numerical simulations.
2) Lattice formulation of fermions coupled to gravity
We formulated lattice Dirac operator of the overlap-type that describes the propagation of a Dirac fermion in a
gravitational ﬁeld. We also analyzed global gauge anomalies associated with Majorana fermions in 8k and 8k+1
dimensions.
3) Mathematical aspects of 2-dimensional gauge theories and string.
We investigate a non-perturbative correction to the N=2 supersymmetric Yang-Mills theory from the discrete
matrix model point of view. We utilize the D-brane picture in superstring theory and localization theorem inorder to derive the discrete matrix model from 2-dimensional Yang-Mills theory on a compact 2-cycles in the ALE
space. We also ﬁnd the relationship to the Dijkgraaf-Vafa theory in the continuum limit.
4) Logarithmic Confromal Field Theory
The following topics are investigated: Free ﬁeld representation for LCFT with boundary; The relation between
Minimal String theory and LCFT; The relation between statistical models and LCFT.
5) Quantum ﬁeld theory over the deformed commutation relation
A quantum theory of free scalar ﬁeld based on the deformed Heisenberg algebra which is the correction ofstringy physics is constructed.
6) Chern Simons Yang Mills Model
We have studied the Chern Simons Yang Mills Model. Non-commutative gauge theories on fuzzy spheres wereobtained in such models. Fuzzy spheres look like dbrane conﬁguration. k coincident fuzzy spheres generates theU(k) gauge group. In this direction, we are continuing eﬀort to address some of the related issues.
(3) High precision calculation of ﬁeld theory and computational science
1) High precision calculation of QED
We have announced the ﬁnal result of our calculation of the electron anomalous magnetic moment. It contains
up to the eighth-order of the perturbation theory of QED. The very reliable result was obtained by using highprecision calculation on RIKEN’s supercomputer system (RSCC). We also succeeded in automating the calculationof the tenth-order of the perturbation theory, particularly in constructing the ultra-violet subtraction terms. Thisis an important step to accelerate our calculation of the entire tenth-order contribution.
The dominant contribution from the tenth order to the muon anomalous magnetic moment was also announced
by us. In contrast to the electron, some speciﬁc Feynman diagrams give rise to the large contributions to themuon anomaly. We explicitly evaluated about 2000 Feynman diagrams which are possible to give the leading andnext-to-leading contributions.
2) Improved perturbation method and its applications
We apply improved perturbation method which is one of the variational schemes to Ising model in twodimensions. It enables us to evaluate free energy and magnetization at strong coupling regions from weak coupling
expansion even in the presence of the phase transition.
We determine approximated transition point in this scheme. In the presence of external magnetic ﬁeld we can- 323 -

see not only stable physical states but metastable one. This reserach motivated by availability of this method to
IIB matrix model which is expected to show a phase transition from 10-dimensional universe to 4-dimensional
universe.

Head
Hikaru KAWAI
Members
Hiroshi SUZUKI
Tsukasa TADA
Postdoctoral Researchers
Tsuguhiko ASAKAWA
Issaku KANAMORI
Tsunehide KUROKISo MATSUURA
Kin-ya ODA
Kazutoshi OHTA
Yuuichirou SHIBUSA
Naoto YOKOI
Contract Researchers
Tatsumi AOYAMA
Hidenori FUKAYA
Ko FURUTA
Makiko MATSUKAWA
Visiting Scientists
Hajime AOKI (Fac. of Sci. and Eng., Saga Univ.,)
Jiro ARAFUNE (National Inst. for Academic Degrees and Univ. Evaluation)
Zyun F. EZAWA (Grad. Sch. of Sci., Tohoku Univ.)
Kazuo FUJIKAWA (College of Sci. and Tech., Nihon Univ.,)
Amihay HANANY (Massachusetts Inst. of Tech., USA)
Masashi HAYAKAWA (Grad. Sch. of Sci., Nagoya Univ.,)
Takeo INAMI (Fac. of Sci. and Eng., Chuo Univ.,)
Nobuyuki ISHIBASI (Grad. Sch. of Pure and Applied Sci., Univ. of Tsukuba,)
Satoshi ISO (High Energy Accelerator Res. Organization)
Hiroshi ITOYAMA (Grad. Sch. of Sci., Osaka City Univ.,)
Toichiro KINOSHITA (Cornell Univ., USA)
Yoshihisa KITAZAWA (High Energy Accelerator Res. Organization)
Ivan KOSTOV (Service de Physique Theoreique, CNRS, FRANCE)
Jnanadeva MAHARANA (Inst. of Phys., INDIA)
Jun NISHIMURA (High Energy Accelerator Res. Organization)
Fumihiko SUGINO (Okayama Inst. for Quantum Phys.)Asato TSUCHIYA (Grad. Sch. of Sci., Osaka Univ.,)
Kensuke YOSHIDA (Univ. of Rome - La Sapienza, ITALY)
Alexei ZAMOLODCHIKOV (Universit’e Montpellier II, FRANCE)
Research Consultants
Keiji IGI
Hironari MIYAZAWA
Yoshio YAMAGUCHI
Junior Research Associate
Tomohisa TAKIMI (Kyoto Univ.)
Secretariy
Yumi KURAMITSU- 324 -

Radiiation Biology Team
1. Abstract
Radiation biology team studies various biological eﬀects of fast heavy ions. It also developes new techniqueto breed plants by heavy-ion irradiations. Fast heavy ions can produce localized dense ionizations in mattersalong their tracks, in contrast to photons (X rays and gamma rays) which produce randomly distributed isolated
ionizations. These localized and dense ionization can cause double-strand breaks of DNA in cells which are noteasily repaired and result in mutation more easily than single-strand breaks. A unique feature of our experimental
facility at the RIKEN Ring Cyclotron (RRC) is that we can irradiate living bodies in atmosphere or in bottles
since the delivered heavy-ion beams have energies high enough to penetrate deep in matter. This team utilize a
dedicated beam line (E5B) of the RRC to irradiate cultivated cells, plants and animals with beams from carbon toiron. Its research subjects cover physiological study of DNA repair, genome analyses of mutation, and developmentof mutation breeding of plants by heavy-ion irradiation. Some new cultivars have already been brought to themarket. It also studies the physical processes of radiation eﬀects in solutions.
2. Major Research Subjects(1) Study on the biological eﬀects by heavy-ion irradiation(2) Studies on ion-beam breeding and genome analysis(3) New medical application of heavy-ion beams(4) Formation of nano-particles in solutions by heavy-ion irradiations
3. Summary of Research Activity
We study biological eﬀects of fast heavy ions from the RIKEN Ring Cyclotron using 135 MeV/N C, N, Ne ions,
95 MeV/N Ar ions and 90 MeV/N Fe ions. We also develop breeding technology of plants. Main subjects are:(1) Study and application of heavy-ion induced plant mutation
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 RIKEN Ring Cyclotron to develop heavy-ion breeding techniques. Genome
analyses are performed to reveal the relation between genotype and phenotype.
(2) Study of heavy ion-induced damage of DNA and its repair processes
We study the double-strand break of DNA induced by heavy-ion irradiation and its repair processes. DNA
double strand break (DSB) is characteristic to heavy-ion irradiation and considered to be the characteristic lesion
responsible for its biological eﬀects. Cells have two pathways to repair DSB, NHEJ and HR, and it is unknown
how the two pathways are involved in repairing the damage caused by heavy-ion irradiation. To elucidate it, we
irradiate higher vertebrate cells lacking DNA repair proteins with C, Ar, or Fe ions and analyze them with colony
formation assay and molecular biology methods.

Team Leader
Tadashi KAMBARA
Members
Tomoko ABE
Masako IZUMIYusuke KAZAMA
Hiroyuki SAITO
Teruyo TSUKADATechnical Staﬀ I
Yoriko HAYASHI
Part-time Staﬀ I
Hideo TOKAIRIN
Part-time Staﬀ II
Sumie OHBU
Visiting Scientists- 325 -Ryutaro AIDA (Natl. Inst. Floricult. Sci.)
Mari AMINO (Tokai Univ. Hospital)
Chang-Hyu BAE (Sunchon Natl. Univ., Korea)
Yasuhiro CHIMI (JAEA)
Hiroyuki DAIMON (Osaka Pref. Univ.)
Makoto FUJIWARA (Grad. Sch., Col. Arts Sci., Univ. of Tokyo)
Koji FURUKAWA (Mukoyama Orchids Co., Ltd.)
Yoshiya FURUSAWA (Natl. Inst. Radiol. Sci.)
Toshinari GODO (Botanic Gardens Toyama)
Misako HAMATANI (Hiroshima City Agric. Forest. Promot. Cen.)
Yasuhide HARA (Kanagawa Inst. Agric. Sci.)
Masanori HATASHITA (Wakasa Wan Energy Res. Cen.)
Atsushi HIGASHITANI (Grad. Sch. Life Sci., Tohoku Univ.)
Ryoichi HIRAYAMA (Natl. Inst. Radiol. Sci.)
Akiko HOKURA (Fac. Sci., Tokyo Univ. of Sci.)
Ichiro HONDA (Natl. Agric. Res. Cen.)
Mitsugu HORITA (Hokuren Agri. Res. Inst.)
Yuji ITO (Natl. Agric. Res. Cen., Hokkaido Region)
Akihiro IWASE (Grad. Sch. Engin., Osaka Pref. Univ.)
Hiroshi KAGAMI (Shizuoka Citrus Exp. Station)
Kensuke KAGEYAMA (Fac. Engin., Saitama Univ.)
Takeshi KANAYA (Suntory Flowers, Ltd.)Si-Yong KANG (Dep. Rad. Plant Breed. Genet., KAERI, Korea)
Tomojirou KOIDE (Riken Vitamin Co., Ltd.)
Tsutomu KUBOYAMA (Ibaraki Univ.)
Norihiko MISHIMA (Fukuda Denshi Co., Ltd.)
Yutaka MIYAZAWA (Grad. Sch. Life Sci., Tohoku Univ.)
Kazumitsu MIYOSHI (Fac. Bioresour. Sci., Akita Pref. Univ.)
Toshikazu MORISHITA (Inst. Rad. Breeding, Natl. Inst. Agric. Res.)
Koji MURAI (Fukui Pref. Univ.)
Daisuke NAKADA (Ela Medical Japan Co. Ltd.)
Ishikawa NORITO (JAEA)
Mio OHNUMA (Inst. Mol. Cell. Biosci., Univ. Tokyo)
Norihiro OHTSUBO (Natl. Inst. Floricult. Sci.)
Fumihisa ONO (Grad. Sch. Natural Sci. & Tech., Okayama Univ.)
Tomo OOMIYA (Hokkaido Ornamental Plants Veg. Res. Cen.)
Kenji OSAWA (Nagano Agric. Res. Cen.)
Kouichi SAKAMOTO (YUKIGUNI AGURI Co.,Ltd. )Tadashi SATO (Grad. Sch. Life Sci., Tohoku Univ.)
Hiroaki SERIZAWA (Nagano Veg. Ornamental Crops Exp. Station)
Takiko SHIMADA (Res. Inst. Agric. Resour., Ishikawa Agric. Coll.)
Fumio SUGAWARA (Tokyo Univ. of Sci.)
Keita SUGIYAMA (Nat. Inst. Veg. Tea Sci.)
Masao SUGIYAMA (Hokko Chem. Ind. Co., Ltd.)
Kazunori SUZUKI (Plant Biotech. Inst. Ibaraki Agric. Cen.)
Kenichi SUZUKI (Suntory Flowers, Ltd.)
Masao SUZUKI (Natl. Inst. Radiol. Sci.)
Hinako TAKEHISA (Grad. Sch. Life Sci., Tohoku Univ.)
Teruhiko TERAKAWA (Hokko Chem. Ind. Co., Ltd.)Ken TOKUHARA (Dogashima Orchid Cen.)
Masanori TOMITA (CRIEPI)
Hisashi TSUJIMOTO (Fac. Agri., Tottori Univ.)
Kozo TSUKADA (Nippon Veterinary and Life Sci. Univ.)
Masao WATANABE (Fac. Agri., Tohoku Univ.)
Takuji YOSHIDA (Takii Seed Co., Ltd.)
Koichiro YOSHIOKA (Tokai Univ. Hospital)
Company-Sponsored Research Trainee
Ayako TABAYASHI (Mitsui Norin Co., Ltd.)
Research Fellows- 326 -

Hideki ASAUMI (Ehime Agricultural Experiment Station)
Eikou OOYABU (Saga Pref. Agr. Res. Cen.)
Takenori SAITO (Shizuoka Tea Exp. Station)
Minoru SAITOH (Fukui Agr. Exp. Sta.)
Tsukasa SHIRAO (Kagoshima Biotechnology Inst.)
Kei-ichiro UENO (Kagoshima Biotechnology Inst.)
Students
Junior Research Associate
Hiroyuki ICHIDA (Grad. Sch. Sci. Tech., Chiba Univ.)
Student trainees
Naoki FUKUDA (Fac. Sci., Tokyo Univ. of Sci.)
Takayuki INOUE (Dept. Phys. Rikkyo Univ.)
Teruhiko KASHIWABARA (Fac. Sci., Tokyo Univ. of Sci.)
Nobuhiro MAEDA (Grad. Sch. Eng., Osaka Pref. Univ.)
Yoshitaka MATSUMOTO (Grad. Sch. Medicine & Sch., Chiba Univ.)
Kiyoshi NISHIHARA (Grad. Sch. Frontier Sci., Univ. of Tokyo)
Tatsuya ONO (Nagahama Inst. Bio-Sci. and Technol.)Kazuhiro SASAKI (Grad. Sch. Life Sci., Tohoku Univ.)
Yuka TANAKA (Nagahama Inst. Bio-Sci. and Technol.)Takashi YOKOYAMA (Dept. Phys. Rikkyo Univ.)- 327 -RI Applications Team
1. Abstract
RI Applications Team performs following researches at the heavy ion accelerators of RIBF: (1) With high-energy
heavy ions from the RIKEN Ring Cyclotron, we produce multi-tracers which are mixtures of various radioactive
nuclides, and use them in research ﬁelds like chemistry, biology, medicine, pharmaceutical and environmental
sciences. (2) We study chemical properties of super-heavy elements (SHE’s) with atomic numbers above 104,
using a gas-jet transport system coupled to Gas-ﬁlled Recoil Ion Separator (GARIS) at RILAC. (3) We developes
a new technology of trace-element analyses.
2. Major Research Subjects(1) Developments and Application Studies on the Multitracer Technology(2) Chemistry of super heavy elements(3) The development of trace element analysis, using the accelerator techniques, and its application to geo andenvironmental sciences
3. Summary of Research Activity
RI applications team utilizes RIBF heavy-ion accelerators for following research subjects:(1) Production and application of multi-tracers
With high-energy heavy ions from the RIKEN Ring Cyclotron, we produces multi-tracers which are mixturesof various radioactive nuclides, and use them in research ﬁelds like chemistry, biology, medicine, pharmaceutical,
and environmental sciences.
(2) Chemistry of super-heavy elements
The electronic structure of superheavy elements (SHE’s) with atomic numbers above 104 is strongly aﬀectedby the relativistic eﬀects due to large nuclear charge. It is interesting to compare their chemical properties withthose of the lighter elements in the same group on the periodic table. However, this frontier of chemistry is
still unexplored since SHE’s can be produced on one-atom-at-a-time scale at heavy-ion accelerators. We utilize
Gas-ﬁlled Recoil Ion Separator (GARIS) at the RILAC to produce SHE atoms, and transport them by gas-jet
system with high eﬃciency to a chemistry laboratory.
(3) Trace element analyses with accelerator technologies
In order to achieve ultra-high sensitivities down to 10−15 –10−17 in multiple trace-element analysis, we develop
technique of accelerator mass spectroscopy (AMS) at the RILAC, with a combination of an ECR ion source anda linear accelerator. We also develop a compact mass spectrometer with a stand-alone ECR ion source. Theretechniques are applied in ﬁelds of cosmochemistry, geochemistry, biochemistry, pharmaceutical and environmental
sciences, archeology, analysis of bio-trace element and materials science.

Team Leader
Tadashi KAMBARA
Members
Shuichi ENOMOTO
Hiromitsu HABA
Kazuya TAKAHASHI
Postdoctoral Researcher
Shinji SHIGYO
Research Associate
Yousuke KANAYAMA
Part-time Staﬀ
Takashi NYU
Temporary Staﬀ
Atsushi ISHIZAWA
Senior Visiting Scientists
Shuichi KIMURA (Showa Women’s Univ.)- 328 -

Visiting Scientists
Kazuhiko AKIYAMA (Tokyo Metropolitan Univ.)
Ryohei AMANO (Fac. Med., Kanazawa Univ.)
Wenjun DING (Colorado State Univ., USA)
Kazutoyo ENDO (Showa Pharm. Univ.)
Kaori ENOMOTO (Univ. Human Arts & Sci.)
Hiroshi HIDAKA (Fac. Sci., Hiroshima Univ.)
Seiichiro HIMENO (Fac. Pharm. Sci., Tokushima Bunri Univ.)
Takako IKEDA (Showa Women’s Univ.)
Hiroko INAGE (Internat. Life Sci. Inst.)
Nobuyoshi ISHII (Natl. Inst. Radiol. Sci.)
Toshiaki ISHII (Natl. Inst. Radiol. Sci.)
Yuko ISHIKAWA (Kagawa Nutrition Univ.)
Shigenao KAWAI (Fac. Agri., Iwate Univ.)
Masuo KONDOH (Showa Pharm. Univ.)
Kenichiro MATSUMOTO (Natl. Inst. Health, USA)
Yoshitaka MINAI (Cen. Art. Sci., Musashi Univ.)
Takeshi MINAMI (Sch. Sci. Eng., Kinki Univ.)
Tomohiro NABEKURA (Fac. Pharm. Sci., Niigata Univ. Pharm. Appl. Life Sci.)
Yuichiro NAGAME (JAEA, Tokai)
Yukiko NAKANISHI (Grad. Sch. Hum. Life Sci., Showa Women’s Univ.)
Van Chuyen NGUYEN (Jpn. Women’s Univ.)
Yasumitsu OGURA (Grad. Sch. Pharm. Sci., Chiba Univ.)
Jun SAITO (Iwatsu Test Instrum. Corp.)
Tomofumi SAKURAGI (Natl. Inst. Radiol. Sci.)
Hiromu SAKURAI (Kyoto Pharm. Univ.)
Hiroshi SHIMIZU (Fac. Sci., Hiroshima Univ.)
Atsushi SHINOHARA (Grad. Sch. Sci., Osaka Univ.)
Hiroyuki SUZUKI (RI Res. Cen., Chiba Univ.)
Toshihiro SUZUKI (Meiji Pharm. Univ.)
Mikiko SUZUKI (Showa Women’s Univ.)
Kazuo SUZUKI (Grad. Sch. Pharm. Sci., Chiba Univ.)
Keiko TAGAMI (Natl. Inst. Radiol. Sci.)
Masaaki TAKAHASHI (Grad. Sci. Agric. Biol. Sci., Osaka Pref. Univ.)
Yoshio TAKAHASHI (Grad. Sch. Sci., Hiroshima Univ.)
Miho TAKAHASHI (Tokyo Univ. Marine Sci. and Tech.)Atsushi TAKEDA (Fac. Pharm. Sci., Univ. Shizuoka)
Haruna TAMANO (Fac. Pharm. Sci., Univ. Shizuoka)
Shinzo TANABE (Meiji Pharm. Univ.)
Tadayasu TOGAWA (Meiji Pharm. Univ.)
Takehiro TOMITANI (Chiba Univ.)
Atsushi TOYOSHIMA (JAEA)
Shigeo UCHIDA (Natl. Inst. Radiol. Sci.)
Kohshin WASHIYAMA (Fac. Med., Kanazawa Univ.)
Tokuko WATANABE (Aoyama Gakuin Women’s Junior College)
Mineo YAMASAKI (Nara Med. Univ.)
Makoto YANAGA (Fac. Sci., Shizuoka Univ.)
Hiroyuki YASUI (Kyoto Pharm. Uni.)
Akihiko YOKOYAMA (Fac. Sci., Kanazawa Univ.)
Shigekazu YONEDA (Natl. Sci. Museu.)
Shozo YOSHIDA (Nara Med. Univ.)
Takashi YOSHIMURA (Grad. Sch. Sci., Osaka Univ.)
Visiting Technician
Ichiro SAKAMOTO
Research Consultants
Yasuyuki GONO
Kuniko MAEDA
Students- 329 -

Part-time Staﬀs
Midori SASAKI (Tokyo Univ. Fish.)Tatsuya URABE (Tokyo Univ. Fish.)Student Trainees
Yusuke ADACHI (Kyoto Pharm. Univ.)
Tomoko ANDO (Showa Women’s Univ.)
Ai HOSODA (Internat. Christian Univ.)
Terumi KATORI (Showa Women’s Univ.)
Takehiko KURIBAYASHI (Grad. Sch. Sci., Osaka Univ.)
Yohei MITSUBORI (Fac. Sci. Tech., Tokyo Univ. of Sci.)
Kazuhiro OOE (Grad. Sch. Sci., Osaka Univ.)
Mizue OZAKI (Showa Women’s Univ.)
Nobuko SAJI (Showa Women’s Univ.)
Mayumi SHIBANUMA (Showa Women’s Univ.)
Tomomasa TAKABE (Grad. Sch. Sci., Osaka Univ.)
Masaki TAKAHASHI (Meiji Pharm. Univ.)
Yuki TASHIRO (Grad. Sch. Sci., Osaka Univ.)- 330 -

RIKEN-BNL Research Center
Experimental Group
1. Abstract
The RIKEN BNL Research Center (RBRC), Experiment Group studies the internal spin structure of the
proton, using the ﬁrst polarized proton collider at Brookhaven, RHIC. The group leads and participates in three
general areas: developing the world’s highest energy polarized proton beams, developing probes of the proton’s
spin content, and seeking a global understanding of all proton spin data. For the proton beam, the group has
developed a new method to measuring the proton beam polarization at high energy which is non-destructive
to the beam and robust. To study the proton structure, the group has identiﬁed very sensitive probes and isdeveloping special apparatus and methods to select the interesting data as the collisions occur. Towards a global
understanding of the internal structure of the proton, the group combines information from RHIC with earlier
studies using electron and muon beams. In a new collaboration with the BELLE experiment at High Energy
Accelerator Research Organization (KEK), we recently discovered that quark fragments can determine the spin
direction of the mother quark.
2. Major Research Subjects(1) Experimental Studies of the Spin Structure of the Nucleon(2) Study of Quark-Gluon Plasma at RHIC
(3) Global QCD Analysis of the Spin Structure of the Nucleon
3. Summary of Research Activity
How is the spin of proton formed with 3 quarks and gluons? This is a very fundamental question in QCD,
Quantum Chromo dynamics. 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 also extended the physics capability of RHIC, Relativistic Heavy Ion
Collider in BNL. At RHIC, Quark Gluon Plasma (QGP) is to be created by colliding two gold nuclei, throughwhich we can study the state of the early Universe just after the Big Bang. In December 2001, polarized protons
were successfully accelerated to 100 GeV, and collisions of transversely polarized protons were observed. Since
then the spin experiment is on going.
The RIKEN-BNL Research Center was established in 1997 to support the RIKEN activities at RHIC in BNL,
and also to promote theoretical studies related to RHIC, i.e. theories of strong interaction. The center’s ﬁrst
director was T.D. Lee (Columbia University), and in October 2003, the former director of BNL, N.P. Samios,
succeeded to the post of director. The center consists of a theory group lead by L. Mclerran (BNL) and an
experimental group lead by H. En’yo, Chief scientist of RIKEN in Wako, who also is an associate director of
RBRC.
(1) Experimental study of spin structure of proton using RHIC polarized proton collider
Although the RHIC operation in 2006 was threatened to be cancelled by the DOE budget problem in the
beginning, we could start a polarized-proton collision run partially supported by a private donation. The PHENIX
experiment collected data from March until June. The RHIC accelerator achieved 2 × 1031 /cm2 /s of the averageluminosity and 60% of the average beam polarization at the center-of-mass energy of 200 GeV. This polarizedproton was the second long run following the one in 2005. The present biggest goal is to elucidate a contributionof the gluon spin in the proton spin. From the 2005 data, we found the gluon polarization in the proton is smaller
than we have expected. By accumulating data in this year and after, we will be able to obtain necessary statistics
for determination of the gluon-spin contribution more precisely.
We are also investigating a contribution of the orbital-angular momentum of quarks and gluons in the proton
which is especially important when the contribution of the gluon spin is small. In 2006, we collected the data withtransversely-polarized proton collisions at 200 GeV to investigate the left-right asymmetry of the two-jet angularcorrelation. Theoretically this asymmetry has sensitivity for the orbital-angular momentum of quarks and gluons
in the proton.
The 200 GeV experiment was performed for three months, and the PHENIX experiment recorded the data
corresponding to 10 inverse picobarn of the integrated luminosity. After this, center-of-mass energy 62.4 GeV
operation was performed with both transversely and longitudinally polarized proton collisions. Even though it
was only a two-week operation, low-energy collisions can give us high-statistics data in the kinematic region wherequarks or gluons have a large fraction of the proton momentum. At the end of the run, there was an accelerator
development for collisions at the center-of-mass energy of 500 GeV in the future. Polarized proton beam was- 331 -

accelerated up to the maximum energy of 250 GeV successfully without signiﬁcant depolarization.
All the physics data in the 2006 run were transferred to RIKEN CC-J in almost real-time via the network
between US and Japan. The physics analysis of the data is making steady progress. In the SPIN2006 international
conference in October at Kyoto, various latest results were released by the PHENIX collaboration. From the 2006
data, preliminary results of neutral-pion double-helicity asymmetry at 62.4 GeV and 200 GeV were presented anddiscussed for the determination of the gluon-spin contribution to the proton spin. A preliminary result of crosssection measurement of direct-photon production from the 2005 data was also presented. This is an importantachievement for the double-helicity asymmetry measurement of direct-photon production in the near future, andfor discussion of the capability of the perturbative QCD to apply for the RHIC data.
(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 hightemperature 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 focus of the research program is now moving
towards measurement of the properties of the matter. The main results of PHENIX that are published are as
follows.
1) Measurement of single electrons from heavy ﬂavor decays in p+p and Au+Au collisions. In p+p collisions,a FONLL pQCD calculation reproduces the data within theoretical uncertainties, indicating that heavy ﬂavor
production at RHIC energy is well understood within pQCD framework. In Au+Au collisions, strong suppressionof electron spectrum at high transverse momentum (pT) as well as strong elliptic ﬂow of single electrons isobserved, indicating that heavy quarks strongly coupled with the dense matter produced in RHIC collisions.
Comparison with the data and theoretical calculations suggests that the viscosity to entropy density ratio h/s isvery small, close to the conjectured quantum lower bound.
2) Measurement of J/PSI in p+p and Au+Au collisions. The new data in p+p collisions has more than 10times of statistics of previously published data. The ﬁrst measurement in Au+Au shows strong suppression of
J/PSI production in Au+Au relative to p+p. The magnitude of the suppression is similar to that was observedin Pb+Pb collisions at CERN SPS. The suppression is stronger in the forward rapidity than in central rapidity.
These results are not explained by models invoking J/PSI destruction based on local energy density.
3) Modiﬁcation of jet correlations. Azimuthal angle correlation of two high transverse momentum particles in
p+p and peripheral Au+Au collisions exhibits clear back-to-back jet structure. The di-jet correlation is modiﬁed
in central Au+Au collisions, suggesting that the parton fragmentation is strongly inﬂuenced by the dense matter.
A systematic measurement of the jet correlation in Au+Au, Cu+Cu, and d+Au collisions are made.
(3) PHENIX detector upgrade
A silicon vertex tracker (VTX) is the ﬁrst of major upgrade detectors for PHENIX. The detector will be jointly
constructed with the US DOE. The VTX consisted of two inner layers of pixel detectors and two outer layersof strip detectors. The main points of progress in 2006 are as follows: 1) The US side of the project is included
in FY07 president’s budget. After a review by the US DOE, the US side of the project received approval. 2)First round prototypes of all components of the pixel detector have been complete. 3) A cosmic ray test of pixel
system prototypes was performed. Clear tracks of cosmic rays are observed by three layers of pixel detectors. 4)
Extensive radiation damage tests of the strip sensors were performed. Prototype sensors were placed in PHENIX
IR to measure the radiation damage in the actual environment. 5) Mechanical and thermal engineering and design
work of the VTX system has started.
We are participating another upgrade projects which include the muon arm upgrade, the construction of thereaction plane counter and the development of the nose cone calorimeter. Especially Perdekamp has gotten
the NSF fund for the muon, and started prototype fabrications of resistive plate chambers and other necessary
detectors.

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Theory Group
1. Abstract
The RIKEN BNL Research Center was established in April 1997 at Brookhaven National Laboratory in New
York, USA. The Center is dedicated to study of strong interactions, including hard QCD/spin physics, lattice
QCD and RHIC physics through nurturing of a new generation of young physicist. The theory group consists ofthree sub groups: numerical lattice QCD, perturbative QCD and phenomenological QCD. The numerical lattice
QCD group built a 600 GFlops QCDSP parallel supercomputer dedicated for the ﬁrst-principle non-perturbative
calculations of QCD. It pioneered the use of the domain-wall fermion method in QCD and we reported an
important calculation of neutral Kaon CP-violations. As a new generation machine, QCDOC with 10 Tﬂops ofcomputing power is completed in JFY2004. The perturbative QCD group has developed various new methods
required for studying hadron structures, especially in spin physics research. The phenomenological QCD group has
pioneered the researches of color superconductivity, isospin density, and small-x phenomena in extreme hadronicmatters.
2. Major Research Subjects(1) Perturbative QCD(2) Lattice QCD numerical research(3) Phenomenological QCD
3. Summary of Research Activity
The RIKEN-BNL Research Center was established in 1997 to support the RIKEN activities at RHIC in BNL,
and also to promote theoretical studies related to RHIC, i.e. theories of strong interaction. The center’s ﬁrst
director was T.D. Lee (Columbia University), and in October 2003, the former director of BNL, N.P. Samios,
succeeded to the post of director. The center consists of a theory group lead by L. Mclerran (BNL) and an
experimental group lead by H. En’yo, Chief scientist of RIKEN in Wako, who also is an associate director of
RBRC.
Research in the RBRC theory group focuses on a wide variety of phenomena caused by the strong interaction,
one of the four fundamental interactions in nature. The strong interaction is described theoretically by Quantum
Chromodynamics (QCD), and the research projects in the RBRC theory group aim to elucidate various phenomena
brought about by the strong interaction from the principles of QCD. Major subjects of our research include
studies (a) based on lattice QCD, (b) on spin physics based on perturbative QCD, and (c) on QCD in extreme
conditions such as high temperature, high density or high energy. RBRC oﬀers RHIC Physics Fellowships, allowing
joint appointments with universities. These Fellowships enable a talented researcher to maintain a tenure track
position at his/her university as well as a Fellow position at RBRC for a certain period of time. This system
was established in order to increase the research potential of RBRC and to disseminate its research activities andresults. At present, RBRC has cooperative agreements with BNL, Columbia University, Massachusetts Instituteof Technology, the State University of New York at Stony Brook, Texas A&M University, Purdue University, Iowa
State University, Kanazawa University, and University of Tsukuba.
(1) Lattice QCDQCDOC (QCD on chip), a second-generation lattice-QCD computer, was developed in the collaboration
amongst this group, Columbia University and IBM. Three units of such a machine with 10 TFlops computing power are in operation since 2005; two in BNL (RBRC and DOE) and one in Edinburgh (UK-QCD), andformed a world-wide strong collaboration for the lattice QCD studies. Such computing power enables us toperform precise calculations with 3 quark ﬂavors with proper handling on the chiral symmetry breaking. Several projects are on going; QCD thermodynamics in ﬁnite temperature/density systems as is produced in RHIC
heavy-ion collisions, calculations of the nucleon axial charge and form factors which relates to the proton spin
problem, and determination of meson’s properties, mass, life, mixing parameters and form factors.
(2) Perturbative QCD and spin physics
The ﬁrst few years running of RHIC spin experiment have motivated much theoretical developments in 2006.
For example, in order to interpret the double spin asymmetry measurements for various processes at RHIC,
the global analyses from several groups have been made last year, and they all found the large positive gluon
polarization is disfavored from the RHIC results. Meanwhile, a remarkable progress has also been made inunderstanding the mechanisms for the nontrivial single transverse spin asymmetries (SSAs) observed by RHIC
and other experiments. It was discovered that the two seeming quite diﬀerent mechanisms for the SSAs are uniﬁed
and describe the same physics in the overlap regions they both apply. The phenomenological application also

- 333 -

showed a successful description of the SSA data from ﬁxed target experiments to RHIC collider experiments, andthe detailed comparison between the theory and experiment have also raised a challenge for further developments.
(3) QCD under extreme conditions
To establish a microscopic picture of relativistic heavy ion collisions, QCD-based theoretical approaches are in
progress. Especially the idea of “color glass condensation (CGC)” can be a key to understand the initial conditionof heavy ion collision. We discussed a possible relation between CGC and the elliptic ﬂow of particles which was
discovered at RHIC. Other phenomenological approaches are in progress to understand the characteristics ofstrongly interacting quark gluon plasma (sQGP).

RIKEN BNL Research Center
Nicholas P. SAMIOS (Director)
Hideto EN’YO (Associate Director)
Experimental
Group Leader
Hideto EN’YO
Deputy Group Leader
Gerry M. BUNCE
Members
Yuji GOTO
Takashi ICHIHARA
Atsushi TAKETANI
Yasushi WATANABE
Yasuyuki AKIBA
Itaru NAKAGAWA
Abhay DESHPANDE∗2
Douglas Edward FIELDS∗2
Matthias GROSS PERDEKAMP∗2David KAWALL∗2
Nobuyuki KAMIHARA∗4
Kensuke OKADA∗2
Wei XIE∗2
Patricia LIEBING∗3
Visiting Members
Naohito SAITO (KEK)
Zheng LEE (BNL)
Ralf-Christian SEIDL (DESY)
Kiyoshi TANIDA (Kyoto Univ.)
Akio OGAWA (BNL)
TheoryGroup Leader
Larry McLERRAN
Deputy Group Leader
Anthony J. BALTZMembers
Christopher DAWSON∗1
Yasumichi AOKI∗2
Thomas BLUM∗1
Takeshi YAMAZAKI∗3
Denes MOLNAR∗1
Kirill TUCHIN∗1
Urs WIEDEMANN∗1- 334 -

Fries RAINER∗1
Tomomi ISHIKAWA∗3
Feng YUAN∗3
Agnes MOCSY∗3
Marquet CYRILLE∗3
Lichtl ADAM∗3
Takumi DOI∗4
Yoshitaka HATTA∗4
Kenji FUKUSHIMA∗4
Masakiyo KITAZAWA∗4
Yoshimasa HIDAKA∗4
Syoichi SASAKI∗1
Peter PETRECZKY∗1
Taku IZUBUCHI∗2
Shinya AOKI∗2
Visiting Members
Miklos GYULASSY (Columbia Univ., USA)
Robert L. JAFFE (Massachusetts Inst. Technol., USA)
Robert MAWHINNEY (Columbia Univ., USA)
Edward SHURYAK (State Univ. New York, Stony Brook, USA)
Shigemi OHTA (KEK)
Konstantinos ORGINOS (Massachusetts Instit. Technol., USA)Kei IIDA (Kochi Univ.)
Tetsufumi HIRANO (Columbia Univ.)
Lin HUEY-WEN (Columbia Univ.)
Administration
Pamela ESPOSITO (Secretary)
Rae GREENBERG (Assistant)Jane Lysik (Secretary)
Taeko ITO (Secretary)
Administrative Manager
Yoshio OKUIZUMI, Hiroshi MIYAMOTO
Deputy Administrative Manager
Ryosuke MARUYAMA∗1∗3

RIKEN BNL Fellow, ∗2 RHIC Physics Fellow,
Research Associate, ∗4 Special Postdoctoral Researcher- 335 -

VI. LIST OF PUBLICATION AND PRESENTATION
Accelerator Development Gr.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Koseki T., Watanabe M., Watanabe S., Chiba Y.,
Goto A., Noda K., and Ohshiro Y.: “Broadband
buncher cavity for beam transport line of HiECR
Ion Source”, Jpn. J. Appl. Phys. Pt.1 45, No. 5A,
pp. 4227–4231 (2006). ＊Ryuto H., Hasebe H., Fukunishi N., Yokouchi S., Goto
A., Kase M., and Yano Y.: “Rotating charge strippers for acceleration of intense heavy-ion beams
at RIKEN”, Nuclear Instruments and Methods inPhysics Research A 569, No. 3, pp. 697–700 (2006).
＊[Book・Proc.](Original Papers) ＊ Subject to Peer Review
上垣外修一, 中川孝秀, 福西暢尚, 齋藤肇, 後藤彰: “理研リングサイクロトロンへの新入射器の検討”, 第 3 回
日本加速器学会年会・第 31 回リニアック技術研究会
論文集, 仙台市, 2006–8, 東北大学，加速器学会, 仙台,
pp. 502–504 (2006).
Oral Presentations(International Conference etc.)
Baba H., Shimoura S., Minemura T., Matsuyama Y.,
Saito A., Ryuto H., Aoi N., Gomi T., Higurashi Y.,
Ieki K., Imai N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kunibu M., Michimasa S., Motobayashi
T., Nakamura T., Sakurai H., Serata M., TakeshitaE., Takeuchi S., Ue K., Teranishi T., Yamada K.,
and Yanagisawa Y.: “Isoscalar monopole and dipole
responses in unstable nucleus 14 O”, Direct Reactions
with Exotic Beams (DREB2005), (Michigan State
University), East Lansing, June (2005).
Baba H., Shimoura S., Minemura T., Matsuyama Y.,
Saito A., Ryuto H., Aoi N., Gomi T., Higurashi Y.,
Ieki K., Imai N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kunibu M., Michimasa S., Motobayashi
T., Nakamura T., Sakurai H., Serata M., TakeshitaE., Takeuchi S., Teranishi T., Ue K., Yamada K.,
and Yanagisawa Y.: “Measurement of inelastic alpha scattering on 14 O”, JINA Workshop on Nuclear
Incompressibility and the Nuclear Equation of State,(JINA), Indiana, USA, July (2005).
Baba H., Shimoura S., Minemura T., Matsuyama Y.,
Saito A., Ryuto H., Aoi N., Gomi T., Higurashi Y.,
Ieki K., Imai N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kunibu M., Michimasa S., Motobayashi
T., Nakamura T., Sakurai H., Serata M., TakeshitaE., Takeuchi S., Teranishi T., Ue K., Yamada K.,
and Yanagisawa Y.: “Isoscalar monopole and dipole
responces in 14 O”, 2nd Joint Meeting of the Nuclear
Physics Divisions of the APS and JPS (Hawaii 2005),

Maui, USA, Sept. (2005).
Baba H., Shimoura S., Saito A., Minemura T.,
Matsuyama Y., Ryuto H., Aoi N., Gomi T.,
Higurashi Y., Ieki K., Imai N., Iwasa N., Iwasaki H.,
Kanno S., Kubono S., Kunibu M., Michimasa S.,
Motobayashi T., Nakamura T., Sakurai H., Serata
M., Takeshita E., Takeuchi S., Teranishi T., Ue
K., Yamada K., and Yanagisawa Y.: “Isoscalar
compressional strengths in 14 O”, 2nd International
Conference on Collective Motion in Nuclei Under
Extreme Conditions (COMEX2), (TU Darmstadt,
GSI), Sankt Goar, Germany, June (2006).
Baba H., Shimoura S., Saito A., Minemura T.,
Matsuyama Y., Ryuto H., Aoi N., Gomi T.,
Higurashi Y., Ieki K., Imai N., Iwasa N., Iwasaki H.,
Kanno S., Kubono S., Kunibu M., Michimasa S.,
Motobayashi T., Nakamura T., Sakurai H., Serata
M., Takeshita E., Takeuchi S., Teranishi T., Ue K.,
Yamada K., and Yanagisawa Y.: “Highly excitedstates of 14 O with the (α,α’) reaction”, 2nd GermanJapanese Workshop on Nuclear Structure and Astrophysics, (RIKEN, CNS, DFG, GSI), Wako, Oct.
(2006).
(Domestic Conference)
龍頭啓充, 長谷部裕雄, 福西暢尚, 後藤彰, 加瀬昌之, 矢野
安重: “RIBF における U 加速のためのチャージスト
リッパーの開発状況”, 第 3 回日本加速器学会年会・第31 回リニアック技術研究会, 仙台, 8 月 (2006).
上垣外修一, 中川孝秀, 福西暢尚, 齋藤肇, 後藤彰: “理研リングサイクロトロンのための新入射器の検討”, 第 3回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,
木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,
後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
Accelerator Operation Gr.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Ryuto H., Abe T., Fukunishi N., Kase M., and YanoY.: “Heavy-ion beam irradiation system for biological samples in RIKEN”, Journal of Biomedical Nanotechnology 2, No. 2, pp. 88–93 (2006).
Ryuto H., Hasebe H., Fukunishi N., Yokouchi S., Goto
A., Kase M., and Yano Y.: “Rotating charge strippers for acceleration of intense heavy-ion beams
at RIKEN”, Nuclear Instruments and Methods inPhysics Research A 569, No. 3, pp. 697–700 (2006).
＊- 337 -

Oral Presentations(Domestic Conference)
龍頭啓充, 長谷部裕雄, 福西暢尚, 後藤彰, 加瀬昌之, 矢野
安重: “RIBF における U 加速のためのチャージスト
リッパーの開発状況”, 第 3 回日本加速器学会年会・第31 回リニアック技術研究会, 仙台, 8 月 (2006).
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,
木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,
後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
坂本久雄, 堀米敦子, 向井弘樹, 日暮利江子, 藤田新, 上蓑
義朋, 加瀬昌之: “理研 RIBF におけるウラン加速の安全管理”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
Accelerator Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Bandyopadhyay A., Kamigaito O., Nayak S. K.,
Pandey H. K., Mondal M., and Chakrabarti A.:“Design of LINAC post-accelerator for VECC RIB
facility using realistic ﬁeld”, Nuclear Instruments
and Methods in Physics Research A 560, 182–190(2006). ＊Kamigaito O.:“Circuit-model representation of
external-Q calculation”, Phys. Rev. Spec. Top.: Accel. Beams 9, No. 6, pp. 062003-1–062003-7 (2006).
＊
Suda K., Okamura H., Uesaka T., Nishikawa J.,
Kumasaka H., Suzuki R., Sakai H., Tamii A.,
Ohnishi T., Sekiguchi K., Yako K., Sakoda S., Kato
H., Hatano M., Maeda Y., Saito T., Ishida T.,
Sakamoto N., Sato Y., Hatanaka K., Wakasa T., andKamiya J.: “Absolute Calibration of the Deuteron
Beam Polarization at Intermediate Energies via the12 α)10 B∗ [2+ ] Reaction”, Nuclear InstrumentsC(d,and Methods in Physics Research A 572, No. Issue2, pp. 745–753 (2007). ＊(Others)
藤澤高志, 上垣外修一: “導体及び導体薄膜の高周波損失について”, HIMAC 116, (2006).
[Book・Proc.](Original Papers) ＊ Subject to Peer Review
上垣外修一, 中川孝秀, 福西暢尚, 齋藤肇, 後藤彰: “理研リングサイクロトロンへの新入射器の検討”, 第 3 回
日本加速器学会年会・第 31 回リニアック技術研究会
論文集, 仙台市, 2006–8, 東北大学，加速器学会, 仙台,
pp. 502–504 (2006).
Oral Presentations(International Conference etc.)
Yagi E., Hayashi T., Koike S., Yoshida T., Higami

N., Hirabayashi K., Takebayashi A., and Ogiwara
K.: “Lattice location of hydrogen in β -V2 H”, International Symposium on Metal-Hydrogen Systems:
Fundamentals and Applications (MH2006), Hawaii,
USA, Oct. (2006).
(Domestic Conference)
上垣外修一, 中川孝秀, 福西暢尚, 齋藤肇, 後藤彰: “理研リングサイクロトロンのための新入射器の検討”, 第 3回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,
木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,
後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
八木栄一, 平林和紘, 村上洋一, 小池茂年, 樋上直太, 林
達也, 武林昭子, 吉田徹, 飯田敬, 菅原孝昌, 宍戸統悦,
荻原清: “酸素を添加した Nb 中の水素の存在状態”,
日本物理学会 2006 年秋季大会, (日本物理学会), 千葉,
9 月 (2006).
前田邦子, 浜中廣見, 荻原清, 長谷川賢一: “結晶分光
PIXE で化学状態の深さ分布を調べる”, 第 23 回 PIXE
シンポジウム, (PIXE 研究協会), 松島, 11 月 (2006).
Ion Source Team
Publications[Book・Proc.](Original Papers) ＊ Subject to Peer Review
上垣外修一, 中川孝秀, 福西暢尚, 齋藤肇, 後藤彰: “理研リングサイクロトロンへの新入射器の検討”, 第 3 回
日本加速器学会年会・第 31 回リニアック技術研究会
論文集, 仙台市, 2006–8, 東北大学，加速器学会, 仙台,
pp. 502–504 (2006).
Oral Presentations(Domestic Conference)
上垣外修一, 中川孝秀, 福西暢尚, 齋藤肇, 後藤彰: “理研リングサイクロトロンのための新入射器の検討”, 第 3回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,
木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,
後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
RILAC Team
Oral Presentations(Domestic Conference)
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,- 338 -

木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,
後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).

Cyclotron Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Ryuto H., Hasebe H., Fukunishi N., Yokouchi S., Goto
A., Kase M., and Yano Y.: “Rotating charge strippers for acceleration of intense heavy-ion beams
at RIKEN”, Nuclear Instruments and Methods inPhysics Research A 569, No. 3, pp. 697–700 (2006).
＊
Oral Presentations(Domestic Conference)
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,
木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,
後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
藤縄雅: “理研 RI ビームファクトリーにおける電熱併給設備”, 日本大学生産工学部第 39 回学術講演会, (日本大学), 習志野, 12 月 (2006).
Beam Technology Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Honda I., Kikuchi K., Matsuo S., Fukuda M., Saito
H., Ryuto H., Fukunishi N., and Abe T.: “Heavyion-induced mutants in sweet pepper isolated by M1
plant selection”, Euphytica 152, No. 1, pp. 61–66(2006). ＊Ryuto H., Abe T., Fukunishi N., Kase M., and YanoY.: “Heavy-ion beam irradiation system for biological samples in RIKEN”, Journal of Biomedical Nanotechnology 2, No. 2, pp. 88–93 (2006).
Ryuto H., Hasebe H., Fukunishi N., Yokouchi S., Goto
A., Kase M., and Yano Y.: “Rotating charge strippers for acceleration of intense heavy-ion beams
at RIKEN”, Nuclear Instruments and Methods inPhysics Research A 569, No. 3, pp. 697–700 (2006).
＊(Review)
阿部知子, 林依子, 市田裕之, 龍頭啓充: “理研仁科加速器研究センターにおける重イオン加速器を用いた植物育種の実用化”, 加速器 3, No. 1, pp. 69–73 (2006).
[Book・Proc.](Original Papers) ＊ Subject to Peer Review

上垣外修一, 中川孝秀, 福西暢尚, 齋藤肇, 後藤彰: “理研リングサイクロトロンへの新入射器の検討”, 第 3 回
日本加速器学会年会・第 31 回リニアック技術研究会
論文集, 仙台市, 2006–8, 東北大学，加速器学会, 仙台,
pp. 502–504 (2006).
(Review)
阿部知子, 龍頭啓充: “重イオンビームを用いた植物の品種改良法の実用化”, 第 30 回放射線科学研究会資料
集, 大阪, 2006–7, 大阪ニュークリア, 大阪, pp. 17–22(2006).

Oral Presentations(International Conference etc.)
Saito H., Hayashi Y., Fukunishi N., Ryuto H., Suzuki
K., Kanaya T., Sugiyama M., Terakawa T., OhtsuboN., Aida R., and Abe T.: “Isolation of sterile mutants of ﬂoricultural plants using heavy-ion
beam irradiation”, 27th International Horticultural
Congress and Exhibition, (International Society for
Horticultural Science), Seaul, Korea, Aug. (2006).
(Domestic Conference)
阿部知子, 龍頭啓充: “重イオンビームを用いた植物の品
種改良法の実用化”, 第 30 回放射線科学研究会, (大阪ニュークリアサイエンス協会), 大阪, 7 月 (2006).
龍頭啓充, 長谷部裕雄, 福西暢尚, 後藤彰, 加瀬昌之, 矢野
安重: “RIBF における U 加速のためのチャージスト
リッパーの開発状況”, 第 3 回日本加速器学会年会・第31 回リニアック技術研究会, 仙台, 8 月 (2006).
上垣外修一, 中川孝秀, 福西暢尚, 齋藤肇, 後藤彰: “理研リングサイクロトロンのための新入射器の検討”, 第 3回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,
木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,
後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
竹久妃奈子, 阿部知子, 林依子, 神波千秋, 斉藤宏之, 市田
裕之, 小沼亮子, 龍頭啓充, 福西暢尚, 宮沢豊, 東海林英夫, 保倉明子, 福田直樹, 中井泉, 佐藤雅志: “重イオンビーム照射による塩害水田耐性イネ突然変異系
統の作出”, 日本育種学会第 110 回講演会, 松山, 9 月(2006).
阿部知子, 林依子, 竹久妃奈子, 安田美智子, 市田裕之,
斉藤宏之, 柏原輝彦, 福田直樹, 小沼亮子, 保倉明子,
寺田靖子, 龍頭啓充, 福西暢尚, 宮沢豊, 仲下英雄, 工藤
俊章, 中井泉, 佐藤雅志: “イネにおける加速器を用いた変異誘発法および変異体解析法の開発”, 日本育種学会第 110 回講演会, 松山, 9 月 (2006).
田平千香子, 漆川直希, 阿部知子, 阪本浩一, 斉藤宏之,
龍頭啓充, 福西暢尚, 村井耕二: “イオンビームによる一粒系コムギ突然変異体 fushi-darake の表現型および遺伝解析”, 日本育種学会第 110 回講演会, 松山, 9 月(2006).
市田裕之, 松山知樹, 龍頭啓充, 福西暢尚, 阿部知子, 木庭- 339 -

卓人: “根粒菌における突然変異誘発とその網羅的検出”, 植物微生物研究会 第 16 回研究交流会, 札幌, 9 月(2006).
市田裕之, 松山知樹, 龍頭啓充, 福西暢尚, 林依子, 阿部知子, 木庭卓人: “重イオンビームによって誘発された
DNA 多型の解析”, 日本 DNA 多型学会第 15 回学術集会, (日本 DNA 多型学会), 福山, 11 月 (2006).

Cryogenic Technology Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Ryuto H., Hasebe H., Fukunishi N., Yokouchi S., Goto
A., Kase M., and Yano Y.: “Rotating charge strippers for acceleration of intense heavy-ion beams
at RIKEN”, Nuclear Instruments and Methods inPhysics Research A 569, No. 3, pp. 697–700 (2006).
＊
Oral Presentations(Domestic Conference)
龍頭啓充, 長谷部裕雄, 福西暢尚, 後藤彰, 加瀬昌之, 矢野
安重: “RIBF における U 加速のためのチャージスト
リッパーの開発状況”, 第 3 回日本加速器学会年会・第31 回リニアック技術研究会, 仙台, 8 月 (2006).
Heavy Ion Nuclear Physics Lab.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Suzuki K., Fujita M., Geissel H., Gilg H., Gillitzer
A., Hayano R., Hirenzaki S., Itahashi K., Iwasaki
M., Kienle P., Matos M., Munzenberg G., OhtsuboT., Sato M., Shindo M., Suzuki T., Weick H.,
Winkler M., Yamazaki T., Sato M., and Yoneyama
T.: “Deeply bound poonic 1s in Sn isotopes”, Nucl.
Phys. A 721, 831c–834c (2003). ＊Adcox K., Bazilevsky A. V., Bunce G. M., DeshpandeA., En’yo H., Fox B., Goto Y., Grosse Perdekamp
M., Hayashi N., Ichihara T., Imai K., Ishihara
M., Jacak B. V., Kobayashi H., Kurita K., Li Z.,
Mao Y., Murata J., Saito N., Sakuma T., Sato H.,
Shibata T., Sugioka M., Taketani A., Tojo J., Torii
H., Watanabe Y., Yokkaichi S., and PHENIX C.:“PHENIX detector overview”, Nuclear Instruments
and Methods in Physics Research A 499, 469–479(2003). ＊Aizawa M., Kurita K., and PHENIX C.: “PHENIX
central arm particle ID detectors”, Nuclear Instruments and Methods in Physics Research A 499, 508–
520 (2003). ＊Akikawa H., En’yo H., Hayashi N., Ichihara T.,
Ishihara M., Kobayashi H., Kurita K., Li Z., Mao Y.,
Murata J., Saito N., Sato H., Shibata T., Sugioka
M., Taketani A., Watanabe Y., Yokkaichi S., and

PHENIX Collaboratio .: “PHENIX muon arms”,
Nuclear Instruments and Methods in Physics Research A 499, 537–548 (2003). ＊Suzuki K., Fujita M., Geissel H., Gilg H., Gillitzer A.,
Hayano R., Hirenzaki S., Itahashi K., Iwasaki M.,
Kienle P., Matos M., Muenzenberg G., Otsubo T.,
Sato M., Shindo M., Suzuki T., Weick H., Winkler
M., Yamazaki T., and Yoneyama T.: “Observattion of Pionic 1s States in Sn Nuclei and Its Implications on Chiral Symmetry Restoration”, Prog.
Theor. Phys. Suppl., No. 149, pp. 32–41 (2003). ＊Beer G. A., Bragadireanu A. M., Cargnelli M.,
Curceanu C., Egger J. -., Fuhrmann H., GierschM., Guaraldo C., Iliescu M., Ishiwatari T., ItahashiK., Iwasaki M., Kienle P., Lauss B., Lucherini V.,
Ludhova L., Marton J., Mulhauser F., Ponta T.,
Schaller L. A., Sirghi D. L., Sirghi F., and Zmeskal
J.: “Kaonic Hydrogen: Status of the DEAR Experiment”, Prog. Theor. Phys. Suppl., No. 149, pp. 240–
246 (2003).
Petrascu M., Constantinescu A., Cruceru I., Giurgiu
M., Isbasescu A., Petrascu H., Bordeanu C.,
Tanihata I., Motobayashi T., Kobayashi T.,
Morimoto K., Katori K., Ozawa A., Suda T.,
Yoshida K., Chiba M., Nishi Y., and Nishimura S.:“Pre-emission of correlated neutrons from 11 Li halo
nuclei”, Nucl. Phys. A 734, 327–330 (2004). ＊Yamada K., Motobayashi T., and Tanihata I.: “RF deﬂector system for proton-rich RI beams in RIKEN”,
Nucl. Phys. A 746, 156c–160c (2004). ＊Tanaka K., Fukuda M., Mihara M., Takechi M.,
Chinda T., Sumikama T., Kudo s., Matsuta K.,
Minamisono T., Ohtsubo T., Suzuki T., Momota
S., Izumikawa T., Yamaguchi T., Oonish T., Ozawa
A., Tanihata I., and Tao Z.: “Density Distributionof Proton Drip-Line Nucleus 17 Ne”, Nucl. Phys. A
746, 532c–535c (2004). ＊Suzuki T., Itahashi K., Iwasaki M., Matsuda Y.,
Okada S., Outa H., Sato M., Strasser P., Tomono
D., and Yamazaki T.: “A search for deeply boundkaonic nuclear states”, Nucl. Phys. A 754, 375c–
382c (2005). ＊Kimura K., Izumikawa T., Koyama R., Ohnishi T.,
Ohtsubo T., Ozawa A., Shinozaki W., SuzukiT., Takahashi M., Tanihata I., Yamaguchi T.,
and Yamaguchi Y.: “High-rate particle identiﬁcation of high-energy heavy ions using a tilted electrode gas ionization chamber”, Nuclear Instruments
and Methods in Physics Research A 538, 608–614(2005). ＊Matsuo Y., Fukuyama Y., and Moriwaki Y.: “Temperature and pressure control of cold helium gas above
liquid helium for laser spectroscopy of atoms andmolecules at 3-30 K”, AIP Conf. Proc. 850, 392–
393 (2006). ＊Funaki Y., Tohsaki A., Horiuchi H., Schuck P., andRopke G.: “Inelastic form factors to alpha-particle- 340 -

condensate states in 12 C and 16 O: what can we learn?”, Eur. Phys. J. A 28, 259–263 (2006). ＊Mazzocco M., Signorini C., Romoli M., De Francesco
A., Dipietro M., Vardaci E., Yoshida K., Yoshida A.,
Bonetti R., De Rosa A., Glodariu T., Guglielmentti
A., Inglima G., La Commara M., Martin B.,
Pierroutsakou D., Sandoli M., Soramel F., Stroe L.,
Kanungo R., Khai N., Motobayashi T., Nomura T.,
Ishikawa T., Ishiyama H., Jeong S., Miyatake H.,
Tanaka M., Sugai I., and Watanabe Y.: “Scattering of 11 Be halo nucleus from 209 Bi at the Coulomb
barrier”, Eur. Phys. J. A 28, 295–299 (2006). ＊Takeuchi S., Aoi N., Baba H., Fukui T., Hashimoto Y.,
Ieki K., Imai N., Iwasaki H., Kanno S., Kondo Y.,
Kubo T., Kurita K., Minemura T., Motobayashi T.,
Nakabayashi T., Nakamura T., Okumura T., OnishiT., Ota S., Sakurai H., Shimoura S., Sugo R., SuzukiD., Suzuki H., Suzuki M., Takeshita E., Tamaki M.,
Tanaka K., Togano Y., and Yamada K.: “Proton
inelastic scattering on 32 Mg”, J. Phys.: Conf. Series
49, 153–154 (2006). ＊Moriwaki Y., Matsuo Y., Fukuyama Y., and Morita N.:“Laser spectroscopic measurements of ﬁne structurechanging cross sections of alkali earth ions in collisions with molecular hydrogen (H2 , D2 )”, J. Phys.
B 39, 4789–4797 (2006). ＊Koseki T., Watanabe M., Watanabe S., Chiba Y.,
Goto A., Noda K., and Ohshiro Y.: “Broadband
buncher cavity for beam transport line of HiECR
Ion Source”, Jpn. J. Appl. Phys. Pt.1 45, No. 5A,
pp. 4227–4231 (2006). ＊Ishiwatari T., Beer G. A., Bragadireanu A. M.,
Cargnelli M., Curceanu P. C., Egger J. P., Fuhrmann
H., Guaraldo C., Iliescu M., Itahashi K., Iwasaki
M., Kienle P., Lauss B., Lucherini V., Ludhova L.,
Marton J., Mulhauser F., Ponta T., Schaller L. A.,
Sirghi D. L., Strasser P., and Zmeslal J.: “New analysis method for CCD X-ray data”, Nuclear Instruments and Methods in Physics Research A 556, 509–
515 (2006). ＊Michimasa S., Shimoura S., Iwasaki H., Tamaki M.,
Ota S., Aoi N., Baba H., Iwasa N., Kanno S.,
Kubono S., Kurita K., Uesaka M., Minemura T.,
Motobayashi T., Notani M., Ong H., Saito A.,
Sakurai H., Takeshita E., Takeuchi S., Yanagisawa
Y., and Yoshida A.: “Proton single-particle statesin the neutron-rich 23 F nucleus”, Phys. Lett. B 638,
146–152 (2006). ＊Dang N. D.: “Consistency of the particle-particle
random-phase approximation and renormalization”,
Phys. Rev. C 74, No. 2, pp. 024318-1–024318-7(2006). ＊Dang N. D. and Tanabe K.: “Self-consistent randomphase approximation at ﬁnite temperature within
the Richardson model”, Phys. Rev. C 74, No. 3, pp.
034326-1–034326-15 (2006). ＊Dang N. D. and Arima A.: “Comment on “Test of themodiﬁed BCS model at ﬁnite temperature””, Phys.
Rev. C 74, No. 5, pp. 509801-1–509801-2 (2006). ＊Furukawa T., Matsuo Y., Hatakeyama A., FukuyamaY., Kobayashi T., Izumi H., and Shimoda T.: “Measurement of a long electronic spin relaxation time ofcesium atoms in superﬂuid helium”, Phys. Rev. Lett.
96, No. 9, pp. 095301-1–095301-4 (2006). ＊Kobayashi T., Kato T., Matsuo Y., Nishimura M.,
Kawai J., and Hayashizaki Y.: “Ionization and Fragmentation of solid C60 by Femtosecond Laser Ablation”, J. Chem. Phys. 126, No. 6, pp. 061101-1–
061101-3 (2007). ＊Matsuo Y., Kobayashi T., Yonekura N., and Nakajima
T.: “Photoionization characteristics of Sr into 5skl
continua through the spin-resolved ion detection bylaser-induced ﬂuorescence”, Jpn. J. Appl. Phys. Pt.1
46, 1181–1185 (2007). ＊Dang N. D.: “Thermal pairing in Richardson model”,
Nucl. Phys. A 784, No. 1-4, pp. 147–160 (2007). ＊Suda K., Okamura H., Uesaka T., Nishikawa J.,
Kumasaka H., Suzuki R., Sakai H., Tamii A.,
Ohnishi T., Sekiguchi K., Yako K., Sakoda S.,
Kato H., Hatano M., Maeda Y., Saito T., IshidaT., Sakamoto N., Sato Y., Hatanaka K., Wakasa
T., and Kamiya J.: “Absolute Calibration of theDeuteron Beam Polarization at Intermediate Ener α)10 B∗ [2+ ] Reaction”, Nuclear Ingies via the 12 C(d,struments and Methods in Physics Research A 572,
No. Issue 2, pp. 745–753 (2007). ＊Oyamatsu K. and Iida K.: “Symmetry energy at subnuclear densities and nuclei in neutron star crusts”,
Phys. Rev. C 75, 015801-1–015801-10 (2007). ＊Mutou R., Chiba J., Enyo H., Fukao Y., Funahashi
H., Hamagaki H., Ieiri M., Ishino M., Kanda H.,
kitaguchi m., Mihara S., Miwa K., Miyashita T.,
Murakami T., Nakura T., Naruki M., Ozawa K.,
Sakuma F., Sasaki O., Sekimoto M., Tabaru T.,
Tanaka K., Togawa M., Yamada S., Yokkaichi S.,
and Yoshimura Y.: “Evidence for in-medium modiﬁcation of the φ meson at normal nuclear density”,
Phys. Rev. Lett. 98, No. 4, pp. 042501-1–042501-4(2007). ＊(Others)
Funaki Y., Schuck P., Horiuchi H., Ropke G., Tohsaki
A., and Yamada T.: “Alpha particle condensationin nuclear systems”, AIP Conf. Proc. 853, 140–145(2006).
Funaki Y., Tohsaki A., Horiuchi H., Schuck P., andRopke G.: “Alpha condensed state in 16 O”, Mod.
Phys. Lett. A 21, No. 31/33, pp. 2331–2340 (2006).
Dang N. D.: “Giant resonances as fundamental modesof nuclear collective excitations”, Frontiers of Basic
Science: Towards New Physics, Earth and Space Science, Mathematics, Hanoi, Vietnam, 2005–9, Osaka
University Press, Osaka, pp. 64–65 (2006).

- 341 -

Oral Presentations(International Conference etc.)
Tanaka K., Fukuda M., Mihara M., Takechi M.,
Chinda T., Sumikama T., Kudo s., Matsuta K.,
Minamisono T., Ohtsubo T., Suzuki T., Momota S.,
Izumikawa T., Yamaguchi T., Oonish T., Ozawa A.,
Tanihata I., and Zheng T.: “Nucleon Density Distribution of Proton Drip-Line Nucleus 17 Ne”, 4th International Conference on Exotic Nuclei and Atomic
Masses (ENAM 04), (Oak Ridge National Laboratory), Pine Mountain, USA, Sept. (2004).
Yamada K., Motobayashi T., Aoi N., Baba H., Demichi
K., Elekes Z., Gibelin J. D., Gomi T., Hasegawa H.,
Imai N., Iwasaki H., Kanno S., Kubo T., Kurita K.,
Matsuyama Y., Michimasa S., Minemura T., Notani
M., Onishi T., Ong H., Ota S., Ozawa A., Saito A.,
Sakurai H., Shimoura S., Takeshita E., Takeuchi S.,
Tamaki M., Togano Y., Yanagisawa Y., Yoneda K.,
and Tanihata I.: “The ﬁrst measurement of reduced
transition probabilities for ﬁrst 2+ excited state in46
Cr, 50 Fe, and 54 Ni”, 4th International Conference
on Exotic Nuclei and Atomic Masses (ENAM 04),
(Oak Ridge National Laboratory), Pine Mountain,
USA, Sept. (2004).
Baba H., Shimoura S., Minemura T., Matsuyama Y.,
Saito A., Ryuto H., Aoi N., Gomi T., Higurashi Y.,
Ieki K., Imai N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kunibu M., Michimasa S., Motobayashi
T., Nakamura T., Sakurai H., Serata M., TakeshitaE., Takeuchi S., Ue K., Teranishi T., Yamada K.,
and Yanagisawa Y.: “Isoscalar monopole and dipole
responses in unstable nucleus 14 O”, Direct Reactions
with Exotic Beams (DREB2005), (Michigan State
University), East Lansing, June (2005).
Baba H., Shimoura S., Minemura T., Matsuyama Y.,
Saito A., Ryuto H., Aoi N., Gomi T., Higurashi Y.,
Ieki K., Imai N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kunibu M., Michimasa S., Motobayashi
T., Nakamura T., Sakurai H., Serata M., TakeshitaE., Takeuchi S., Teranishi T., Ue K., Yamada K.,
and Yanagisawa Y.: “Measurement of inelastic alpha scattering on 14 O”, JINA Workshop on Nuclear
Incompressibility and the Nuclear Equation of State,(JINA), Indiana, USA, July (2005).
Togano Y., Gomi T., Motobayashi T., Ando Y., Aoi
N., Baba H., Demichi K., Elekes Z., Fukuda N.,
Fulop Z., Hasegawa H., Higurashi Y., Ieki K., ImaiN., Ishihara M., Ishikawa K., Iwasa N., Iwasaki H.,
Kanno S., Kondo Y., Kubo T., Kubono S., Kurita
K., Matsuyama Y., Michimasa S., Minemura T.,
Miura M., Murakami H., Nakamura T., Notani M.,
Ota S., Saito A., Sakurai H., Serata M., ShimouraS., Sugimoto T., Takeshita E., Takeuchi S., Ue K.,
Yamada K., Yanagisawa Y., Yoneda K., Yoshida A.,
Futakami U., and Kunibu M.: “Coulomb dissociation of 27 P for Study of 26 Si(p,γ)27 P reaction”, 2ndJoint Meeting of the Nuclear Physics Divisions of

the APS and JPS (Hawaii 2005), Maui, USA, Sept.
(2005).
Aoi N.: “Exploring the shell structure in very neutron rich pf g-shell nuclei through the γ-ray spectroscopy technique”, 2nd Joint Meeting of the Nuclear Physics Divisions of the APS and JPS (Hawaii2005), Maui, USA, Sept. (2005).
Baba H., Shimoura S., Minemura T., Matsuyama Y.,
Saito A., Ryuto H., Aoi N., Gomi T., Higurashi Y.,
Ieki K., Imai N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kunibu M., Michimasa S., Motobayashi
T., Nakamura T., Sakurai H., Serata M., TakeshitaE., Takeuchi S., Teranishi T., Ue K., Yamada K.,
and Yanagisawa Y.: “Isoscalar monopole and dipole
responces in 14 O”, 2nd Joint Meeting of the Nuclear
Physics Divisions of the APS and JPS (Hawaii 2005),
Maui, USA, Sept. (2005).
Michimasa S., Aoi N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kurita K., Minemura T., Motobayashi
T., Notani M., Ong H., Ota S., Saito A., ShimouraS., Takeshita E., Tamaki M., Uesaka M., Yanagisawa
Y., Yoshida A., Sakurai H., Takeuchi S., and Baba
H.: “Measurement of proton transfer reaction for
single-particle states in 23 F”, 2nd Joint Meeting of
the Nuclear Physics Divisions of the APS and JPS(Hawaii 2005), Maui, USA, Sept. (2005).
Yamada K., Iwasa N., Bishop S., Elekes Z., Gibelin
J. D., Hosoi M., Ieki K., Ishikawa K., Iwasaki
H., Kawai S., Kondo Y., Kubono S., Kurita K.,
Kurokawa M., Matsui N., Minemura T., Morikawa
H., Nakamura T., Niikura M., Notani M., Ota S.,
Saito A., Sakurai H., Shimoura S., Sugawara K.,
Sugimoto T., Suzuki H., Suzuki T., Takeshita E.,
Takeuchi S., Tanihata I., Teranishi T., Togano Y.,
Yamaguchi K., Yanagisawa Y., and Motobayashi T.:“New Coulomb Excitation Measurement of 18 Ne”,
2nd Joint Meeting of the Nuclear Physics Divisionsof the APS and JPS (Hawaii 2005), Maui, USA,
Sept. (2005).
Furukawa T., Matsuo Y., Hatakeyama A., FukuyamaY., Kobayashi T., Izumi H., and Shimoda T.: “Newlaser spectroscopic method for the measurement of
nuclear moments”, 2nd Joint Meeting of the Nuclear
Physics Divisions of the APS and JPS (Hawaii 2005),
Maui, USA, Sept. (2005).
Motobayashi T.: “Perspective of nuclear physics andnuclear astrophysics studies with fast exotic beams”,
2nd Joint Meeting of the Nuclear Physics Divisionsof the APS and JPS (Hawaii 2005), Maui, USA,
Sept. (2005).
Kanno S., Aoi N., Takeuchi S., Sakurai H., GlasmacherT., Mueller W. F., Bazin D., Bowen M. D., Campbell
C. M., Cook J. M., Dinca D., Gade A., Iwasaki H.,
Kubo T., Kurita K., Motobayashi T., Nakamura T.,
Suzuki H., Terry J. R., Zwahlen H., and Yoneda
K.: “Proton Inelastic scattering on 74 Ni”, 2nd Joint
Meeting of the Nuclear Physics Divisions of the APS- 342 -

and JPS (Hawaii 2005), Maui, USA, Sept. (2005).
Furukawa T., Matsuo Y., Hatakeyama A., Ito T., Ota
Y., Fukuyama Y., Kobayashi T., and Shimoda T.:“Laser-microwave double resonance method in superﬂuid helium for the measurement of nuclear moments”, 11th International Workshop on Polarized
Sources and Targets (PST05), (CNS and RIKEN),
Tokyo, Nov. (2005).
Takeuchi S., Aoi N., Baba H., Fukui T., HashimotoY., Ieki K., Imai N., Iwasaki H., Kanno S., Kondo
Y., Kurita K., Minemura T., Motobayashi T.,
Nakabayashi T., Nakamura T., Okumura T., OnishiT., Ota S., Sakurai H., Shimoura S., Sugo R., SuzukiD., Suzuki H., Suzuki M., Takeshita E., Tamaki
M., Tanaka K., Togano Y., and Yamada K.: “Proton inelastic scattering of 32 Mg”, International Symposium on Structure of Exotic Nuclei and Nuclear
Forces (SENUF06), (University of Tokyo), Tokyo,
Mar. (2006).
Takeuchi S.: “Development of hybrid array for γ-ray
spectroscopy”, International Workshop on “Nuclear
Physics with RIBF”, RIKEN, Mar. (2006).
Funaki Y., Yamada T., Horiuchi H., Tohsaki A.,
Schuck P., and Ropke G.: “Alpha condensed statein 16 O”, RCNP Osaka Spring Workshop on Cluster Condensation and Nucleon Correlation in Nuclei,
Ibaraki, Apr. (2006).
Dang N. D.: “Giant resonances under extreme conditions”, International Conference on Current problems in nuclear physics and atomice energy (NPAEKyiv2006), (Kyiv institutre for nuclear research of
National Academy of Sciences of Ukraine), Kyiv,
Ukraine, May–June (2006).
Baba H., Shimoura S., Saito A., Minemura T.,
Matsuyama Y., Ryuto H., Aoi N., Gomi T.,
Higurashi Y., Ieki K., Imai N., Iwasa N., Iwasaki H.,
Kanno S., Kubono S., Kunibu M., Michimasa S.,
Motobayashi T., Nakamura T., Sakurai H., Serata
M., Takeshita E., Takeuchi S., Teranishi T., Ue
K., Yamada K., and Yanagisawa Y.: “Isoscalar
compressional strengths in 14 O”, 2nd International
Conference on Collective Motion in Nuclei Under
Extreme Conditions (COMEX2), (TU Darmstadt,
GSI), Sankt Goar, Germany, June (2006).
Funaki Y., Yamada T., Tohsaki A., Horiuchi H.,
Schuck P., and Ropke G.: “Alpha cluster states in
12
C and 16 O”, International Conference on Nuclear
Structure ’06 (NS06), (Oak Ridge National Laboratory), Oak Ridge, USA, July (2006).
Funaki Y., Yamada T., Tohsaki A., Horiuchi H.,
Schuck P., and Ropke G.: “Alpha condensed statein 16 O”, International Workshop on Alpha Particle Condensation in Nuclear Systems, (University of
Munich), Munich, Germany, Aug. (2006).
Michimasa S., Shimoura S., Iwasaki H., Tamaki M.,
Ota S., Aoi N., Baba H., Iwasa N., Kanno S.,
Kubono S., Kurita K., Minemura T., Motobayashi

T., Notani M., Ong H., Saito A., Sakurai H.,
Takeshita E., Takeuchi S., Uesaka M., Yanagisawa
Y., and Yoshida A.: “Proton shell structure inneutron-rich 23 F”, International Conference on Nucleus Nucleus Collisions (NN2006), Rio de Janeiro,
Brazil, Aug.–Sept. (2006).
Dang N. D.: “(invited lecture) “Superﬂuid-normal
phase transition in ﬁnite systems and its eﬀect on
the damping of giant reasonances at ﬁnite temperature””, Predeal Summer School in Nuclear Physics“Collective Motion and Phase Transitions in Nuclear
Systems”, Predeal, Romania, Aug.–Sept. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., YamaguchiT., Yoneda A., Yoshida A., and YuLiang Z.: “Experiments on Synthesis of the Heaviest Elements at
RIKEN (SHE and FFD)”, Tours Symposium on Nuclear Physics VI (TOURS 2006), (Konan University), Tours, France, Sept. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., YamaguchiT., Yoneda A., Yoshida A., and YuLiang Z.: “Experiments on Synthesis of the Heaviest Elements
at RIKEN Status and Perspectives”, Workshop on
the Atomic Properties of the Heaviest Elements:
Towards the Island of Stability, (LMU-Muenchen),Germany, Chiemsee, Sept. (2006).
Funaki Y., Yamada T., Tohsaki A., Horiuchi H.,
Schuck P., and Ropke G.: “4 alpha condensed
states in 16 O”, 2nd German-Japanese Workshop on
Nuclear Structure and Astrophysics, Wako, Oct.
(2006).
Baba H., Shimoura S., Saito A., Minemura T.,
Matsuyama Y., Ryuto H., Aoi N., Gomi T.,
Higurashi Y., Ieki K., Imai N., Iwasa N., Iwasaki H.,
Kanno S., Kubono S., Kunibu M., Michimasa S.,
Motobayashi T., Nakamura T., Sakurai H., Serata
M., Takeshita E., Takeuchi S., Teranishi T., Ue K.,
Yamada K., and Yanagisawa Y.: “Highly excitedstates of 14 O with the (α,α’) reaction”, 2nd GermanJapanese Workshop on Nuclear Structure and Astrophysics, (RIKEN, CNS, DFG, GSI), Wako, Oct.
(2006).
Suzuki Y., Horiuchi W., Sarhan B. A., and Kohama
A.: “Structure of carbon isotopes studied with theanalysis of reaction cross sections”, 2nd GermanJapanese Workshop on Nuclear Structure and Astrophysics, (DFG, GSI, University of Tokyo, and
RIKEN), Wako, Oct. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., Yamaguchi T.,- 343 -

Yoneda A., Yoshida A., and YuLiang Z.: “Search for
the Heaviest Elements at RIKEN”, 6th International
Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006),(Advanced Science Research Center, Japan Atomic
Energy Agency), Tokaimura, Oct. (2006).
(Domestic Conference)
米田健一郎: “Two neutron knockout reaction of protonrich nuclei 34 Ar, 30 S, and 26 Si”, 京都大学基礎物理学
研究所研究会「弱結合系の束縛機構と新しいダイナミクス」, 京都, 12 月 (2005).
小濱洋央, 飯田圭, 親松和浩: ““黒い” 原子核描像に基づく核半径と反応断面積”, RIBF-Day1 実験を睨んだ反
応断面積実験に向けたミニワークショップ, Wako, 1
月 (2006).
須田利美: “SCRIT 開発の現状”, RIBF-Day1 実験を睨んだ反応断面積実験に向けたミニワークショップ, 和
光, 1 月 (2006).
青井考: “γ-spectroscopy experiment at BigRIPS”,
RIBF に於ける γ 線核分光, 和光, 2–2 月 (2006).
加藤俊幸, 小林徹, 松尾由賀利, 西村美月, 小山理恵子,
松村米浩, 山本浩, 河合純, 林崎良英: “基板上試料におけるフェムト秒とナノ秒レーザーアブレーションの比較”, 第 53 回応用物理学関係連合講演会, 東京, 3 月(2006).
竹下英里, 青井考, 大田晋輔, 武内聡, 鈴木宏, 馬場秀忠,
Bishop S., 福井利晃, 井手口栄治, 家城和夫, 今井伸明,
岩崎弘典, 菅野祥子, 近藤洋介, 久保敏幸, 栗田和好,
日下健祐, 峯村俊行, 本林透, 中林彩, 中村隆司, 中尾
太郎, 新倉潤, 奥村俊文, 王惠仁, 大西健夫, 櫻井博儀,
下浦享, 須合亮平, 鈴木大介, 鈴木賢, 玉城充, 田中
鐘信, 栂野泰宏, 山田一成: “中性子過剰核 Cr 同位体の陽子非弾性散乱”, 日本物理学会第 61 回年次大会,
松山, 3 月 (2006).
道正新一郎, 下浦享, 岩崎弘典, 玉城充, 大田晋輔, 青井
考, 馬場秀忠, 岩佐直仁, 菅野祥子, 久保野茂, 栗田
和好, 峯村俊行, 本林透, 野谷将広, 王惠仁, 齋藤明登,
櫻井博儀, 竹下英里, 武内聡, 上坂明子, 柳澤善行, 吉田敦: “Single-particle states in 23 F by a proton transfer reaction”, 日本物理学会第 61 回年次大会, (日本物理学会), 松山, 3 月 (2006).
米田健一郎: “Two-neutron knockout reaction to Tz =−2 nuclei 24 Si, 28 S, and 32 Ar”, 日本物理学会第 61 回
年次大会, 松山, 3 月 (2006).
赤石義紀, 山崎敏光: “ケイオン核—批判に答えて”, 日
本物理学会第 61 回年次大会, 松山, 3 月 (2006).
炭竃聡之, 長友傑, 小倉昌子, 岩越丈尚, 中島良樹, 藤原
裕樹, 松多健策, 南園忠則, 福田光順, 三原基嗣, 南園
啓, 山口貴之: “質量数 A=8 体系 β 崩壊における中間子交換効果”, 日本物理学会第 61 回年次大会, 松山, 3
月 (2006).
古川武: “レーザー分光による超流動ヘリウム中での原子・原子核スピン物理の研究”, RIBF 核物理セミナー,
和光, 4 月 (2006).
青井考: “γ-spectroscopy on neutron rich nuclei”, RI
ビーム科学シンポジウム, 新潟, 5 月 (2006).
武内聡, 青井考, 馬場秀忠, 福井利晃, 橋本佳子, 家城

和夫, 今井伸明, 岩崎弘典, 菅野祥子, 近藤洋介, 栗田
和好, 峯村俊行, 本林透, 中林彩, 中村隆司, 奥村俊文,
大西健夫, 大田晋輔, 櫻井博儀, 下浦享, 須合亮平, 鈴木
大介, 鈴木宏, 鈴木賢, 竹下英里, 玉城充, 田中鐘信,
栂野泰宏, 山田一成: “32 Mg と 34 Si の γ 線核分光”,
RIBF ミニワークショップ「Island of Inversion に関する実験・理論の現状と今後の展望–7 < Z < 20 領域
中性子過剰核の低励起状態に関する検討会–」, 和光, 5
月 (2006).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 太田嘉穂, 藤掛
浩太郎, 小林徹, 下田正: “超流動ヘリウム中に植え込まれた原子の超微細構造”, 原子・分子・光科学 (AMO)
第 3 回討論会, 東京, 6 月 (2006).
小濱洋央: “弾性散乱断面積と反応断面積”, RIBF ミニ
ワークショップ「不安定核の弾性散乱」, (理研), 和光,
6 月 (2006).
船木靖郎, 山田泰一, Schuck P., 堀内昶, 東崎昭弘,
Ropke G.: 理研 RIBF ミニワークショップ「陽子中性子の弱結合現象及び α 凝縮状態に関するミニワー
クショップ」, 和光, 7 月 (2006).
馬場秀忠: “DAQ system for RI-beam experiment at
RARF and RIBF”, Annual RI Beam Factory (RIBF)
Users Meeting 2006, 和光, 8 月 (2006).
松本琢磨: “6 He 核力クーロン力分解反応解析”, KEK 研
究会「現代の原子核物理–多様化し進化する原子核の描像–」, つくば, 8 月 (2006).
船木靖郎, 山田泰一, Schuck P., 堀内昶, 東崎昭弘,
Ropke G.: “Alpha condensed state in 16 O”, 日本
物理学会 2006 年秋季大会, 奈良, 9 月 (2006).
飯田圭, 小濱洋央, 親松和浩: “反応断面積公式：不安定核への応用”, 日本物理学会 2006 年秋季大会, 奈良, 9
月 (2006).
田中鐘信, 山口貴之, 鈴木健, 小沢顕, 相場健, 青井考,
泉川卓司, 稲福清彦, 岩佐直仁, 上坂明子, 大坪隆, 小林圭, 小室麻里, 近藤洋介, 篠田遼子, 篠原摩有子, 鈴木宏, 武内聡, 竹下英里, 武智麻耶, 栂野泰宏, 中島真平,
中林彩, 馬場秀忠, 橋爪祐平, 福田光順, 松山貴史, 道正
新一郎, 安野琢磨, 山田一成, 吉竹利織, 久保敏幸, 中村
隆司, 櫻井博儀, 本林透: “中性子過剰核 19,20,22 C の反応断面積測定”, 日本物理学会 2006 年秋季大会, 奈良, 9 月 (2006).
小濱洋央, 飯田圭, 親松和浩: “反応断面積と相互作用断面積：“黒い” 原子核描像に基づく解析”, 日本物理学会 2006 年秋季大会, 奈良, 9 月 (2006).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 太田嘉穂, 藤掛
浩太郎, 小林徹, 下田正: “超流動ヘリウム中のアルカ
リ金属原子のスピン偏極および磁気共鳴”, 日本物理学会 2006 年秋季大会, 奈良, 9 月 (2006).
野地俊平, 三木謙二郎, 矢向謙太郎, 川畑貴裕, 久保木浩功, 酒井英行, 関口仁子, 須田健嗣: “中性子偏極度
計 SMART-NPOL の最適化解析”, 日本物理学会 2006
年秋季大会, 奈良, 9 月 (2006).
松本琢磨, 緒方一介, 江上智晃, 井芹康統, 八尋正信, 上村
正康: “6 He 核力・クーロン分解反応の解析”, 日本物理学会 2006 年秋季大会, 奈良, 9–9 月 (2006).
青井考: “Status of γ-spectroscopy experiment andDay1 experiemnt at RIBF”, RIBF ミニワークショ- 344 -

ップ「RIBF に於ける γ 分光実験 (II)」, 和光, 10 月
(2006).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 太田嘉穂, 藤掛
浩太郎, 小林徹, 下田正: “超流動ヘリウム中に植え込まれた原子の超微細構造”, 第 3 回「停止・低速不安定核を用いた核分光研究」研究会, (京都大学原子炉実験所), 大阪府熊取, 11 月 (2006).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 太田嘉穂, 藤掛
浩太郎, 小林徹, 下田正: “超流動ヘリウム中におけるアルカリ金属原子の超微細構造”, RIBF ミニワーク
ショップ「レーザー光利用の次世代加速器実験：その発展と物理学への貢献」, 和光, 11 月 (2006).
田中鐘信, 山口貴之, 鈴木健, 小沢顕, 相場健, 青井考,
泉川卓司, 稲福清彦, 岩佐直仁, 上坂明子, 大坪隆, 小林圭, 小室麻里, 近藤洋介, 篠田遼子, 篠原摩有子, 鈴木宏, 武内聡, 竹下英里, 武智麻耶, 栂野泰宏, 中島真平,
中林彩, 馬場秀忠, 橋爪祐平, 福田光順, 松山貴史, 道正
新一郎, 安野琢磨, 山田一成, 吉竹利織, 久保敏幸, 中村
隆司, 櫻井博儀, 本林透: “22 C 及び炭素同位体の反応断面積実験”, RIBF ミニワークショップ「反応断面積
で探る核構造」, (RIKEN), 和光, 11 月 (2006).
飯田圭: “反応断面積の理論的解析”, RIBF ミニワー
クショップ「反応断面積で探る核構造」, 和光, 11 月
(2006).
長友傑, 南園啓, 松多健策, Levy C. D., 三原基嗣, 炭竃
聡之, 小沢顕, 田岸義宏, 小倉昌子, 松宮亮平, 福田
光順, 山口充孝, Behr J. A., Jackson K. P., 藤原弘樹,
安野琢磨, 太田寛史, 橋爪祐平, 千葉明子, 南園忠則:“ベータ NMR 法を用いた質量数 20 体系の β 線角度分布の精密測定による第二種核子流の探索”, 平成
18 年度京都大学原子炉実験所専門研究会「原子核プ
ローブ生成とそれを用いた物性研究 (II)」, 大阪府熊取, 11–11 月 (2006).
船木靖郎, 山田泰一, 東崎昭弘, 堀内昶, Schuck P.,
Ropke G.: “有限核における α 粒子凝縮状態”, 京都大学基礎物理学研究所 滞在型研究会「原子核クラスター物理の現状と展望」, (京都大学基礎物理学研究所), 京都, 12 月 (2006).
玉川徹, 岩本慎也, 早藤麻美, 福島かおり, 浜垣秀樹, 山口
頼人, 牧島一夫, 宮坂浩正, 桜井郁也, 門叶冬樹, 犬塚
将英: “理研における GEM 開発の現状と将来”, 第 3回マイクロパターンガス検出器（MPGD）研究会, (佐賀大学), 佐賀, 1 月 (2007).
松本琢磨, 江上智晃, 緒方一介, 井芹康統, 八尋正信, 上村
正康: “不安定核分解反応による di-neutron 相関の研究”, RCNP 研究会「核子多体系におけるクラスター現象」, (大阪大学核物理研究センター), 大阪, 2 月 (2007).
船木靖郎, 山田泰一, Schuck P., 堀内昶, 東崎昭弘,
Ropke G.: “16 O における 4 α 凝縮状態”, RCNP 研
究会「核子多体系におけるクラスター現象」, (大阪大学核物理研究センター), 茨木, 2 月 (2007).
小林徹, 加藤俊幸, 松尾由賀利, 西村美月, 河合純, 林崎
良英: “フェムト秒レーザーアブレーションによるフ
ラーレンのイオン化および解離”, 第 32 回フラーレ
ン・ナノチューブ総合シンポジウム, (フラーレン・ナ
ノチューブ学会), 名古屋, 2–2 月 (2007).
松尾由賀利, 小林徹, 中嶋隆: “超短レーザーパルス誘起

スピン偏極の光学的検出理研”, 第 54 回応用物理学関係連合講演会, 相模原, 3 月 (2007).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 藤掛浩太郎, 小林徹, 下田正: “超流動ヘリウム中に植え込まれた原子の超微細構造”, 日本物理学会 2007 年春季大会, 鹿児島,
3 月 (2007).
小濱洋央, 飯田圭, 親松和浩: “くろたま模型で眺めた相互作用断面積”, 日本物理学会 2007 年春季大会, 八王子, 3 月 (2007).
伊藤龍浩, 古川武, 松尾由賀利, 畠山温, 小林徹, 藤掛
浩太郎, 小田島仁司, 下田正: “超流動ヘリウム中における Al の偏極生成”, 日本物理学会 2007 年春季大会, 鹿児島, 3 月 (2007).

Applied Nuclear Physics Lab.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Adcox K., Bazilevsky A. V., Bunce G. M., DeshpandeA., En’yo H., Fox B., Goto Y., Grosse Perdekamp
M., Hayashi N., Ichihara T., Imai K., Ishihara
M., Jacak B. V., Kobayashi H., Kurita K., Li Z.,
Mao Y., Murata J., Saito N., Sakuma T., Sato H.,
Shibata T., Sugioka M., Taketani A., Tojo J., Torii
H., Watanabe Y., Yokkaichi S., and PHENIX C.:“PHENIX detector overview”, Nuclear Instruments
and Methods in Physics Research A 499, 469–479(2003). ＊Akikawa H., En’yo H., Hayashi N., Ichihara T.,
Ishihara M., Kobayashi H., Kurita K., Li Z., Mao
Y., Murata J., Saito N., Sato H., Shibata T.,
Sugioka M., Taketani A., Watanabe Y., YokkaichiS., and PHENIX Collaboratio .: “PHENIX muonarms”, Nuclear Instruments and Methods in Physics
Research A 499, 537–548 (2003). ＊Murata J., Horaguchi T., Kamihara N., Kobayashi H.,
Shibata T., and PHENIX C.: “Optical alignment
system for the PHENIX muon tracking chambers”,
Nuclear Instruments and Methods in Physics Research A 500, 309–317 (2003). ＊Yoshimi A., Asahi K., Emori S., Tsukui M., andOshima S.: “Nuclear Spin Maser Oscillation of 129 Xe
by Means of Optical-Detection Feedback”, HyperﬁneInteract. 159, No. 1/4, pp. 401–405 (2004). ＊Ishikawa D., Inui M., Matsuda K., Tamura K., BaronA., Tsutsui S., Tanaka Y., and Ishikawa T.: “Collective dynamics in dense Hg vapour”, J. Phys.: Condens. Matter 16, L45–L50 (2004). ＊Tanaka Y., Baron A., Kim Y., Thomas K. J.,
Hill J. P., Honda Z., Iga F., Tsutsui S., andIshikawa D.: “Search for orbitons in LaMnO3 ,YTiO3 and KCuF3 using high-resolution inelastic x-ray scattering”, New J. Phys. (Web)(http://www.iop.org/EJ/journal/NJP 6, 161-1–
161-13 (2004). ＊Baron A., Uchiyama H., Tanaka Y., Tsutsui S.,- 345 -

Ishikawa D., Lee S., Heid R., Bohnen K., TajimaS., and Ishikawa T.: “Kohn Anomaly in MgB2 by
Inelastic X-Ray Scattering”, Phys. Rev. Lett. 92,
197004-1–197004-4 (2004). ＊Uchiyama H., Baron A., Tsutsui S., Tanaka Y., Hu W.,
Yamamoto A., Tajima S., and Endoh Y.: “Softening of Cu-O Bond Stretching Phonons in Tetragonal HgBa2 CuO4+δ ”, Phys. Rev. Lett. 92, 197005-1–
197005-4 (2004). ＊Uchiyama H., Baron A., Tsutsui S., Tanaka Y., Hu W.,
Yamamoto A., Tajima S., and Endoh Y.: “Phonon
softening in HgBa2 CuO4+δ observed by inelastic Xray scattering”, Phys. Stat. Sol.(c) 1, No. 11, pp.
3130–3133 (2004). ＊Asahi K., Kameda D., Ueno H., Yoshimi A., UchidaM., Miyoshi H., Shimada K., Nagae D., Kijima G.,
Haseyama T., Watanabe H., Takemura M., Arai
T., Oshima S., and Umeya A.: “Study of electromagnetic moments in unstable nuclei with radioactive nuclear beams”, J. Phys.: Con. Ser. 20, 59–64(2005). ＊Kobayashi Y., Nonaka H., Miyazaki J., Kubo K., Ueno
H., Yoshimi A., Miyoshi H., Kameda D., Shimada
K., Nagae D., Asahi K., and Yamada Y.: “Reactionof 57 Mn implanted into solid oxygen”, Hyperﬁne Interact. 166, 357–361 (2006). ＊Kubo K., Kobayashi Y., Nonaka H., Yamada Y., SakaiY., Shoji H., and Matsue H.: “Neutron in-beam
Mossbauer spectroscopic study of iron disulﬁde atroom temperature”, Hyperﬁne Interact. 166, 425–
428 (2006). ＊Sugimoto T., Nakamura T., Fukuda N., Miura M.,
Kondo Y., Aoi N., Baba H., Bazin D., Gomi T.,
Hasegawa H., Hashimoto Y., Imai N., Kobayashi
T., Kubo T., Motobayashi T., Ohara M., Saito
A., Sakurai H., Shimoura S., Attukalathil V.
M., Watanabe K., Watanabe Y., Yakushiji T.,
Yanagisawa Y., Yoneda K., and Ishihara M.:“Invariant-mass spectroscopy of the neutron-drip
line nucleus 14 Be”, J. Phys.: Con. Ser. 49, 43–44(2006). ＊Asahi K., Uchida M., Shimada K., Nagae D., Kameda
D., Ueno H., Yoshimi A., Takemura M., Arai T.,
Takase K., Inoue T., Kawamura H., Murata J.,
Watanabe H., Haseyama T., Kobayashi Y., Umeya
A., and Ishihara M.: “Structure of unstable nuclei
from nuclear moments and decays”, J. Phys.: Con.
Ser. 49, 79–84 (2006). ＊Kameda D., Ueno H., Asahi K., Takemura M., Yoshimi
A., Haseyama T., Uchida M., Shimada K., Nagae D.,
Kijima G., Arai T., Takase K., Suda S., Inoue T.,
Murata J., Kawamura H., Kobayashi Y., Watanabe
H., and Ishihara M.: “Nuclear moments of neutronrich 32 Al”, J. Phys.: Con. Ser. 49, 138–139 (2006).
＊
Yagi E., Koike S., Sugawara T., Shisido T., Urai T.,
and Ogiwara K.: “Displaced-T site occupancy of hy-

drogen in Nb alloyed with a high concentration ofMo”, J. Phys. Soc. Jpn. 75, No. 3, pp. 034802-1–
034802-7 (2006). ＊Tsutsui S., Kobayashi Y., Okada T., Haba H., Onodera
H., Yoda Y., Mizumaki M., Tanida H., Uruga T.,
Sekine C., Shirotani I., Kikuchi D., Sugawara H.,
and Sato H.: “A Possible Novel Magnetic Ordering in SmRu4 P12 ”, J. Phys. Soc. Jpn. 75, 0937031–
0937034 (2006). ＊Cole A., Akimunne H., Austin S., Bazin D., vanden Berg A., Berg G., Brown J., Daito I., Fujita
Y., Fujiwara M., Gupta S., Hara K., Harakeh M.,
Janecke J., Kawabata T., Nakamura T., RobertD., Sherril B., Steiner M., Ueno H., and Zegers R.:“Measurement of the Gamow-Teller Strength Distribution in 58 Co via the 58 Ni(t, 3 He) reaction at 115
MeV/nucleon”, nucl-ex 0603019, 1–14 (2006). ＊Sato W., Ueno H., Taniguchi A., Itsuki Y., KasamatsuY., Shinohara A., Asahi K., Asai K., and Ohkubo
Y.: “Nuclear quadrupole relaxation of 140 Ce implanted in highly oriented pyrolytic graphite”, Phys.
Rev. B 74, No. 21, pp. 214302-1–214302-7 (2006). ＊Zegers R., Akimune H., Austin S., Bazin D.,
van den Berg A., Berg G., Brown J., Cole A.,
Daito I., Fujita Y., Fujiwara M., Gales S., Harakeh
M., Hashimoto H., Hayami R., Hitt G., Howard
M., Itoh M., Janecke J., Kawabata T., Kawase
K., Kinoshita M., Nakamura T., Nakanishi K.,
Nakayama S., Okumura S., Richter W., Roberts
D., Sherrill B., Shimbara Y., Steiner M., UchidaM., Ueno H., Yamagata T., and Yosoi M.: “The(t,3He) and (3He,t) reactions as probes of GamowTeller strength”, Phys. Rev. C 74, 024309-1–02430915 (2006). ＊Furukawa T., Matsuo Y., Hatakeyama A., FukuyamaY., Kobayashi T., Izumi H., and Shimoda T.: “Measurement of a long electronic spin relaxation time ofcesium atoms in superﬂuid helium”, Phys. Rev. Lett.
96, No. 9, pp. 095301-1–095301-4 (2006). ＊Yoshida Y., Kobayashi Y., Hayakawa K., Yukihira K.,
Yoshida A., Ueno H., Shimura F., and Ambe F.:“In situ observation of substitutional and interstitial Fe atoms in Si after GeV-implantation: An inbeam Mössbauer study”, Physica B 376/377, 69–72(2006). ＊(Review)
吉見彰洋: “スピン偏極した不安定核ビームの新しい生成方法を目指した装置開発”, CYRIC ニュース 40, 4–7(2006).
八木栄一: “核反応チャネリング法で見た金属・合金中の水素の存在状態”, 固体物理 41, No. 11, pp. 728–736(2006).
Oral Presentations(International Conference etc.)
Yoshimi A., Asahi K., Ueno H., Kameda D., Takemura
M., Uchida M., Shimada K., Nagae D., Arai T.,- 346 -

Takase K., Inoue T., Kawamura H., Murata J.,
Kijima G., and Haseyama T.: “Electric quadrupole
moments of neutron rich Al isotope”, International
Symposium on Exotic Nuclei (EXON 2006), (GSI,GANIL, RIKEN), Khanty-Mansiysk, Russia, July–
July (2005).
Furukawa T., Matsuo Y., Hatakeyama A., FukuyamaY., Kobayashi T., Izumi H., and Shimoda T.: “Newlaser spectroscopic method for the measurement of
nuclear moments”, 2nd Joint Meeting of the Nuclear
Physics Divisions of the APS and JPS (Hawaii 2005),
Maui, USA, Sept. (2005).
Furukawa T., Matsuo Y., Hatakeyama A., Ito T., Ota
Y., Fukuyama Y., Kobayashi T., and Shimoda T.:“Laser-microwave double resonance method in superﬂuid helium for the measurement of nuclear moments”, 11th International Workshop on Polarized
Sources and Targets (PST05), (CNS and RIKEN),
Tokyo, Nov. (2005).
Kameda D., Asahi K., Ueno H., Yoshimi A., Watanabe
H., Haseyama T., Kobayashi Y., Uchida M.,
Shimada K., Nagae D., Kato G., Emori S., KijimaG., Takemura M., Arai T., Oshima S., Tsukui M.,
Yagi E., Kubo T., Yoshida A., and Ishihara M.:“Production of spin-polarized RI beams via projectile fragmentation and the application to nuclear moment measurements”, 11th International Workshop
on Polarized Sources and Targets (PST05), (RIKEN
and The Center for Nuclear Study (CNS) ), Tokyo,
Nov. (2005).
Asahi K.: “Radioactive nuclear beams as microscopic
probes in matter”, University of California at Berkeley and Tokyo Institute of Technology Interdepartment Symposium on Nanoscience and Quantum
Physics, Berkeley, USA, Jan. (2006).
Ueno H.: “Production of RI beams with RIPS in
the RIBF conﬁguration”, Pre-Meeting “Council for
China-Japan Research Collaboration on Nuclear
Physics”, Wako, Feb. (2006).
Sugimoto T., Nakamura T., Fukuda N., Miura M.,
Kondo Y., Aoi N., Baba H., Bazin D., Gomi T.,
Hasegawa H., Hashimoto Y., Imai N., Kobayashi
T., Kubo T., Motobayashi T., Ohara M., Saito
A., Sakurai H., Shimoura S., Attukalathil V.
M., Watanabe K., Watanabe Y., Yakushiji T.,
Yanagisawa Y., Yoneda K., and Ishihara M.:“Invariant-mass spectroscopy of the neutron-drip
line nucleus 14 Be”, International Symposium on
Structure of Exotic Nuclei and Nuclear Forces(SENUF06), (CNS and RIKEN), Tokyo, Mar.
(2006).
Kameda D., Asahi K., Ueno H., Yoshimi A., HaseyamaT., Watanabe H., Uchida M., Shimada K., Nagae
D., Takemura M., Arai T., Kijima G., Takase K.,
Suda S., Inoue T., Kobayashi Y., Yagi E., Kubo T.,
Yoshida A., and Ishihara M.: “Nuclear moments ofneutron-rich 32 Al(Z = 11, N = 19)”, International

Symposium on Structure of Exotic Nuclei and Nuclear Forces (SENUF06), (The Center for Nuclear
Study (CNS)), Tokyo, Mar. (2006).
Asahi K.: “Structure of unstable nuclei from nuclear
moments and beta decays”, International Symposium on Structure of Exotic Nuclei and Nuclear
Forces (SENUF06), (CNS and RIKEN), Tokyo, Mar.
(2006).
Yoshimi A., Asahi K., Uchida M., Inoue T., andOshima S.: “Electric dipole moment induced
from nucleus”, International Workshop on “Nuclear
Physics with RIBF”, Wako, Mar. (2006).
Kameda D., Ueno H., Asahi K., Yoshimi A., HaseyamaT., Watanabe H., Uchida M., Nagae D., Shimada K.,
Takemura M., Arai T., Takase K., Inoue T., Kato G.,
Kijima G., Emori S., Suda S., Tsukui M., Murata J.,
Kawamura H., Kobayashi Y., Yagi E., Kubo T., andIshihara M.: “Nuclear moment measurements using spin-polarized RI beams via projectile fragmentation: Recent results and the prospect in RIBF”,
International Workshop on “Nuclear Physics with
RIBF”, Wako, Mar. (2006).
Ueno H.: “Present and future program driven bypolarized-RI beams”, International Workshop on“Nuclear Physics with RIBF”, Wako, Mar. (2006).
Murata J.: “T-Violation Experiment using Electron
Polarimeter”, International Workshop on “Nuclear
Physics with RIBF”, Tokyo, Mar. (2006).
Ueno H.: “Nuclear moments of neutron-rich aluminumisotopes”, 7th International Conference on Radioactive Nuclear Beams (RNB7), Cortina d’Ampezzo,
Italy, July (2006).
Ueno H.: “Nuclear-moment research in RIKEN”, 1st
Annual RI Beam Factory (RIBF) Users Meeting
2006, Wako, Aug. (2006).
Ueno H.: “Study of unstable nuclei through the measurement of nuclear moments”, 5th CNS International Summer School (CISS06), Wako, Aug. (2006).
Kameda D., Asahi K., Ueno H., Yoshimi A., HaseyamaT., Watanabe H., Uchida M., Shimada K., Nagae D.,
Kijima G., Takemura M., Takase K., Arai T., Inoue
T., Suda S., Murata J., Kawamura H., Kobayashi
Y., and Ishihara M.: “Nuclear moments of neutronrich 32 AL: Shell structure around the “Island of
Inversion””, The XI International Conference on
Nucleus Nucleus Collisions (NN2006), (Universityof Sao Paulo), Rio de Janeiro, Brazil, Aug.–Sept.
(2006).
Ueno H.: “Measurement of nuclear moments at
RIKEN”, Tours Symposium on Nuclear Physics VI(TOURS 2006), Tours, France, Sept. (2006).
Nagatomo T., Minamisono K., Matsuta K., Levy C.
D., Sumikama T., Ozawa A., Tagisi Y., Mihara M.,
Ogura M., Matsumiya R., Fukuda M., Yamaguchi
M., Behr J. A., Jackson K. P., Fujiwara H., Ohta
H., Yasuno T., Hashizume Y., and MinamisonoT.: “Alignment Correlation Terms In β-Ray An-- 347 -

gular Distributions From Spin Aligned 20 F And
20Na”, 17th International Spin Physics Symposium (SPIN2006), (Kyoto University), Kyoto, Oct.
(2006).
Murata J., Asahi K., Kameda D., Kawamura H.,
Nagae D., Narota K., Shimada K., Toyoda T.,
Uchida M., Ueno H., and Yoshimi A.: “BetaNeutrino Correlation and T-Violation Experimentin Nuclear Beta Decay”, 17th International Spin
Physics Symposium (SPIN2006), (Department of
Physics, Kyoto University), Kyoto, Oct. (2006).
Yoshimi A., Ueno H., Sugimoto T., Shimada K.,
Nagae D., Murata J., Kawamura H., Kameda D.,
and Asahi K.: “Development of Atomic Beam Resonance Method with RI beams”, 17th International
Spin Physics Symposium (SPIN2006), (Kyoto University), Kyoto, Oct. (2006).
Nagae D., Asahi K., Ueno H., Kameda D., Takemura
M., Takase K., Yoshimi A., Sugimoto T., NagatomoT., Kobayashi Y., Uchida M., Shimada K., Arai
T., Inoue T., Kagami S., and Hatakeyama N.: “Experimental technique for nuclear moment measurements by the β-NMR method using spin polarized RI
beams via projectile fragmentation reaction”, 17th
International Spin Physics Symposium (SPIN2006),(Kyoto University), Kyoto, Oct. (2006).
Kameda D., Asahi K., Ueno H., Yoshimi A., HaseyamaT., Watanabe H., Uchida M., Nagae D., Shimada
K., Takemura M., Arai T., Takase K., Inoue T.,
Suda S., Kobayashi Y., Murata J., Kawamura H.,
and Ishihara M.: “Nuclear moment measurementsof neutron-rich Al isotopes using spin-polarized RI
beams: Determination of the boundary of the “island of inversion””, 17th International Spin Physics
Symposium (SPIN2006), (Kyoto University), Kyoto,
Oct. (2006).
Ueno H.: “Nuclear-moment measurements at RIKEN
and perspectives in RIBF”, 17th International Spin
Physics Symposium (SPIN2006), (Kyoto University), Kyoto, Oct. (2006).
Shimada K., Nagae D., Asahi K., Arai T., Takemura
M., Inoue T., Takase K., Kagami S., HatakeyamaN., Kobayashi Y., Ueno H., Yoshimi A., Kameda D.,
Nagatomo T., Sugimoto T., Kubono S., Yamaguchi
H., Wakabayashi Y., Amadio G., Hayakawa S.,
Murata J., and Kawamura H.: “Production of Polarized Radioactive Beams via The Inverse-kinematics
Reactions and Their Applications”, 17th International Spin Physics Symposium (SPIN2006), (Kyoto
University), Kyoto, Oct. (2006).
Asahi K., Uchida M., Yoshimi A., Inoue T., andOshima S.: “Search for an Atomic EDM with
optical-coupling nuclear spin oscillator”, 17th International Spin Physics Symposium (SPIN2006), (Kyoto University), Kyoto, Oct. (2006).
Yagi E., Hayashi T., Koike S., Yoshida T., Higami
N., Hirabayashi K., Takebayashi A., and Ogiwara

K.: “Lattice location of hydrogen in β -V2 H”, International Symposium on Metal-Hydrogen Systems:
Fundamentals and Applications (MH2006), Hawaii,
USA, Oct. (2006).
(Domestic Conference)
上野秀樹: “停止・低速 RIB を用いた核モーメント測定”,
第 2 回「停止・低速不安定核ビームを用いた核分光研
究」研究会, (理研，KEK 他), 東海, 3 月 (2006).
亀田大輔: “中性子過剰 Al 同位体の核モーメントと周辺の殻構造”, 理研シンポジウム「電磁モーメント，低エ
ネルギー核分光から探る不安定核の構造—その現状と将来的課題—」, 和光, 3 月 (2006).
亀田大輔: “イントルーダー領域の中性子過剰核の電磁気モーメント測定”, RIBF ミニワークショップ「Islandof Inversion に関する実験・理論の現状と今後の展望–
7 < Z < 20 領域中性子過剰核の低励起状態に関する検討会–」, 和光, 5 月 (2006).
杉本崇: “中性子ドリップライン核 14 Be の不変質量核分
光”, RIBF 核物理セミナー, 和光, 5 月 (2006).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 太田嘉穂, 藤掛
浩太郎, 小林徹, 下田正: “超流動ヘリウム中に植え込まれた原子の超微細構造”, 原子・分子・光科学 (AMO)
第 3 回討論会, 東京, 6 月 (2006).
杉本崇: “Invariant-mass Spectroscopy of 14 Be”, 第 5 回
CNS 国際サマースクール (CISS06), (東京大学原子核科学研究センター (CNS)), 和光, 8 月 (2006).
八木栄一, 平林和紘, 村上洋一, 小池茂年, 樋上直太, 林
達也, 武林昭子, 吉田徹, 飯田敬, 菅原孝昌, 宍戸統悦,
荻原清: “酸素を添加した Nb 中の水素の存在状態”,
日本物理学会 2006 年秋季大会, (日本物理学会), 千葉,
9 月 (2006).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 太田嘉穂, 藤掛
浩太郎, 小林徹, 下田正: “超流動ヘリウム中のアルカ
リ金属原子のスピン偏極および磁気共鳴”, 日本物理学会 2006 年秋季大会, 奈良, 9 月 (2006).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 太田嘉穂, 藤掛
浩太郎, 小林徹, 下田正: “超流動ヘリウム中に植え込まれた原子の超微細構造”, 第 3 回「停止・低速不安定核を用いた核分光研究」研究会, (京都大学原子炉実験所), 大阪府熊取, 11 月 (2006).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 太田嘉穂, 藤掛
浩太郎, 小林徹, 下田正: “超流動ヘリウム中におけるアルカリ金属原子の超微細構造”, RIBF ミニワーク
ショップ「レーザー光利用の次世代加速器実験：その発展と物理学への貢献」, 和光, 11 月 (2006).
吉見彰洋, 上野秀樹, 杉本崇, 旭耕一郎, 島田健司, 長江
大輔, 亀田大輔, 村田次郎, 川村広和: “原子線法を用いた RI の核偏極生成のための開発研究”, 平成 18 年度
京都大学原子炉実験所専門研究会「原子核プローブ生
成とそれを用いた物性研究 (II)」, 大阪府熊取, 11–11
月 (2006).
長友傑, 南園啓, 松多健策, Levy C. D., 三原基嗣, 炭竃
聡之, 小沢顕, 田岸義宏, 小倉昌子, 松宮亮平, 福田
光順, 山口充孝, Behr J. A., Jackson K. P., 藤原弘樹,
安野琢磨, 太田寛史, 橋爪祐平, 千葉明子, 南園忠則:“ベータ NMR 法を用いた質量数 20 体系の β 線角度分布の精密測定による第二種核子流の探索”, 平成- 348 -

18 年度京都大学原子炉実験所専門研究会「原子核プ
ローブ生成とそれを用いた物性研究 (II)」, 大阪府熊取, 11–11 月 (2006).
吉見彰洋, 旭耕一郎, 内田誠, 井上壮志, 畠山直人: “低周波核スピンメーザーの開発と 129 Xe 原子 EDM 探索への応用”, RIBF ミニワークショップ「レーザー光利用の次世代加速器実験：その発展と物理学への貢献」,
和光, 11–12 月 (2006).
杉本崇, 吉見彰洋, 上野秀樹, 村田次郎, 川村広和, 長江
大輔, 島田健司, 旭耕一郎: “偏極不安定核生成のための原子線共鳴法の開発”, 日本物理学会 2007 年春季大会, 八王子, 3 月 (2007).
古川武, 松尾由賀利, 畠山温, 伊藤龍浩, 藤掛浩太郎, 小林徹, 下田正: “超流動ヘリウム中に植え込まれた原子の超微細構造”, 日本物理学会 2007 年春季大会, 鹿児島,
3 月 (2007).
伊藤龍浩, 古川武, 松尾由賀利, 畠山温, 小林徹, 藤掛
浩太郎, 小田島仁司, 下田正: “超流動ヘリウム中における Al の偏極生成”, 日本物理学会 2007 年春季大会, 鹿児島, 3 月 (2007).
Radioactive Isotope Physics Lab.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Takeuchi S., Aoi N., Baba H., Fukui T., Hashimoto Y.,
Ieki K., Imai N., Iwasaki H., Kanno S., Kondo Y.,
Kubo T., Kurita K., Minemura T., Motobayashi T.,
Nakabayashi T., Nakamura T., Okumura T., OnishiT., Ota S., Sakurai H., Shimoura S., Sugo R., SuzukiD., Suzuki H., Suzuki M., Takeshita E., Tamaki M.,
Tanaka K., Togano Y., and Yamada K.: “Proton
inelastic scattering on 32 Mg”, J. Phys.: Con. Ser.
49, 153–154 (2006). ＊Yoshida K., Yamagami M., and Matsuyanagi K.:“Pairing and continuum eﬀects on low-frequency
quadrupole vibrations in deformed Mg isotopes close
to the neutron drip line”, Nucl. Phys. A 779, 99–115(2006). ＊Michimasa S., Shimoura S., Iwasaki H., Tamaki M.,
Ota S., Aoi N., Baba H., Iwasa N., Kanno S.,
Kubono S., Kurita K., Uesaka M., Minemura T.,
Motobayashi T., Notani M., Ong H., Saito A.,
Sakurai H., Takeshita E., Takeuchi S., Yanagisawa
Y., and Yoshida A.: “Proton single-particle statesin the neutron-rich 23 F nucleus”, Phys. Lett. B 638,
146–152 (2006). ＊Majima T., Nakai Y., Mizuno T., Tsuchida H., andItoh A.: “Fragmentation processes of C60 in multiple
electron loss and capture collisions of 2-MeV Si2+ ”,
Phys. Rev. A 74, 033201-1–033201-7 (2006). ＊Nakamura T., Wada M., Okada K., Ishida Y.,
Takamine A., Yamazaki Y., Kambara T., Kanai
Y., Kojima T., Nakai Y., Oshima N., Yoshida A.,
Kubo T., Katayama I., Lioubimov V., Wollnik H.,
Varentsov V., and Schuessler H. A.: “Laser spec-

troscopy of 7,10 Be+ in an online ion trap”, Phys.
Rev. A 74, 052503-1–052503-5 (2006). ＊Hagino K., Lwin N. W., and Yamagami M.: “Deformation parameter for diﬀuse density”, Phys. Rev. C
74, 017310-1–017310-4 (2006). ＊[Book・Proc.](Review)
佐藤勝彦, 望月優子: “元素の起源”, シリーズ現代の天文学 I 人類の住む宇宙, 日本評論社, 東京, pp. 94–137(2007).
(Others)
望月優子: “Investigating the origin of the elementswith RI-Beam Factory”, 密封・非密封事業所を対象とした平成 18 年度放射線業務従事者のための教育訓
練講習会 II テキスト, 京都, 2006–10, 日本アイソトー
プ協会, 京都, pp. 17–27 (2006).
Oral Presentations(International Conference etc.)
Baba H., Shimoura S., Minemura T., Matsuyama Y.,
Saito A., Ryuto H., Aoi N., Gomi T., Higurashi Y.,
Ieki K., Imai N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kunibu M., Michimasa S., Motobayashi
T., Nakamura T., Sakurai H., Serata M., TakeshitaE., Takeuchi S., Ue K., Teranishi T., Yamada K.,
and Yanagisawa Y.: “Isoscalar monopole and dipole
responses in unstable nucleus 14 O”, Direct Reactions
with Exotic Beams (DREB2005), (Michigan State
University), East Lansing, June (2005).
Togano Y., Gomi T., Motobayashi T., Ando Y., Aoi
N., Baba H., Demichi K., Elekes Z., Fukuda N.,
Fulop Z., Hasegawa H., Higurashi Y., Ieki K., ImaiN., Ishihara M., Ishikawa K., Iwasa N., Iwasaki H.,
Kanno S., Kondo Y., Kubo T., Kubono S., Kurita
K., Matsuyama Y., Michimasa S., Minemura T.,
Miura M., Murakami H., Nakamura T., Notani M.,
Ota S., Saito A., Sakurai H., Serata M., ShimouraS., Sugimoto T., Takeshita E., Takeuchi S., Ue K.,
Yamada K., Yanagisawa Y., Yoneda K., Yoshida A.,
Futakami U., and Kunibu M.: “Coulomb dissociation of 27 P for Study of 26 Si(p,γ)27 P reaction”, 2ndJoint Meeting of the Nuclear Physics Divisions of
the APS and JPS (Hawaii 2005), Maui, USA, Sept.
(2005).
Michimasa S., Aoi N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kurita K., Minemura T., Motobayashi
T., Notani M., Ong H., Ota S., Saito A., ShimouraS., Takeshita E., Tamaki M., Uesaka M., Yanagisawa
Y., Yoshida A., Sakurai H., Takeuchi S., and Baba
H.: “Measurement of proton transfer reaction for
single-particle states in 23 F”, 2nd Joint Meeting of
the Nuclear Physics Divisions of the APS and JPS(Hawaii 2005), Maui, USA, Sept. (2005).
Kanno S., Aoi N., Takeuchi S., Sakurai H., GlasmacherT., Mueller W. F., Bazin D., Bowen M. D., Campbell
C. M., Cook J. M., Dinca D., Gade A., Iwasaki H.,
Kubo T., Kurita K., Motobayashi T., Nakamura T.,- 349 -

Suzuki H., Terry J. R., Zwahlen H., and Yoneda
K.: “Proton Inelastic scattering on 74 Ni”, 2nd Joint
Meeting of the Nuclear Physics Divisions of the APS
and JPS (Hawaii 2005), Maui, USA, Sept. (2005).
Takeuchi S., Aoi N., Baba H., Fukui T., HashimotoY., Ieki K., Imai N., Iwasaki H., Kanno S., Kondo
Y., Kurita K., Minemura T., Motobayashi T.,
Nakabayashi T., Nakamura T., Okumura T., OnishiT., Ota S., Sakurai H., Shimoura S., Sugo R., SuzukiD., Suzuki H., Suzuki M., Takeshita E., Tamaki
M., Tanaka K., Togano Y., and Yamada K.: “Proton inelastic scattering of 32 Mg”, International Symposium on Structure of Exotic Nuclei and Nuclear
Forces (SENUF06), (University of Tokyo), Tokyo,
Mar. (2006).
Yamagami M.: “New insight into collective excitations from the novel concept of single-particle motions in weakly-bound superﬂuid nuclei”, International Workshop on “Nuclear Physics with RIBF”,
Wako, Mar. (2006).
Baba H., Shimoura S., Saito A., Minemura T.,
Matsuyama Y., Ryuto H., Aoi N., Gomi T.,
Higurashi Y., Ieki K., Imai N., Iwasa N., Iwasaki H.,
Kanno S., Kubono S., Kunibu M., Michimasa S.,
Motobayashi T., Nakamura T., Sakurai H., Serata
M., Takeshita E., Takeuchi S., Teranishi T., Ue
K., Yamada K., and Yanagisawa Y.: “Isoscalar
compressional strengths in 14 O”, 2nd International
Conference on Collective Motion in Nuclei Under
Extreme Conditions (COMEX2), (TU Darmstadt,
GSI), Sankt Goar, Germany, June (2006).
Motizuki Y. and Madokoro H.: “The late-time supernova evolution induced by anisotropic neutrino radiation and the r-process environment (a poster paper)”, International Symposium on Nuclear Astrophysics: Nuclei in the Cosmos 9, Geneva, Switzerland, June (2006).
Motizuki Y.: “Activities in Nuclear Astrophysics at
Riken Nishina Center”, Opening meeting of JapanUS Theory Institute for Physics with Exotic Nuclei,
Wako, June (2006).
Azuma T., Nakano Y., Kondo C., Hatakeyama A.,
Komaki K., Nakai Y., Yamazaki Y., Takada E.,
and Murakami T.: “Autler-Townes doublet observed
through doubly resonant coherent excitation”, 22ndInternational Conference on Atomic Collisions in
Solids (ICACS 2006), Berlin, Germany, July (2006).
Yamagami M.: “Pairing and continuum eﬀects for
low-frequency vibrational excitations”, International
Conference on Nuclei at the limits “Nuclear Structure ’06”, (Oak Ridge National Laboratory), Oak
Ridge, USA, July (2006).
Azuma T., Nakano Y., Kondo C., Hatakeyama A.,
Komaki K., Nakai Y., Yamazaki Y., Takada E.,
and Murakami T.: “Crystal-dressed HCI observed
through doubly-resonant coherent excitation”, 13th
International Conference on the Physics of Highly

Charged Ions (HCI 2006), (Scool of Physics of University College Dublin and School of Physics l Science of Dublin City University), Belfast, UK, Aug.–
Sept. (2006).
Michimasa S., Shimoura S., Iwasaki H., Tamaki M.,
Ota S., Aoi N., Baba H., Iwasa N., Kanno S.,
Kubono S., Kurita K., Minemura T., Motobayashi
T., Notani M., Ong H., Saito A., Sakurai H.,
Takeshita E., Takeuchi S., Uesaka M., Yanagisawa
Y., and Yoshida A.: “Proton shell structure inneutron-rich 23 F”, International Conference on Nucleus Nucleus Collisions (NN2006), Rio de Janeiro,
Brazil, Aug.–Sept. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., YamaguchiT., Yoneda A., Yoshida A., and YuLiang Z.: “Experiments on Synthesis of the Heaviest Elements at
RIKEN (SHE and FFD)”, Tours Symposium on Nuclear Physics VI (TOURS 2006), (Konan University), Tours, France, Sept. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., YamaguchiT., Yoneda A., Yoshida A., and YuLiang Z.: “Experiments on Synthesis of the Heaviest Elements
at RIKEN Status and Perspectives”, Workshop on
the Atomic Properties of the Heaviest Elements:
Towards the Island of Stability, (LMU-Muenchen),Germany, Chiemsee, Sept. (2006).
Baba H., Shimoura S., Saito A., Minemura T.,
Matsuyama Y., Ryuto H., Aoi N., Gomi T.,
Higurashi Y., Ieki K., Imai N., Iwasa N., Iwasaki H.,
Kanno S., Kubono S., Kunibu M., Michimasa S.,
Motobayashi T., Nakamura T., Sakurai H., Serata
M., Takeshita E., Takeuchi S., Teranishi T., Ue K.,
Yamada K., and Yanagisawa Y.: “Highly excitedstates of 14 O with the (α,α’) reaction”, 2nd GermanJapanese Workshop on Nuclear Structure and Astrophysics, (RIKEN, CNS, DFG, GSI), Wako, Oct.
(2006).
Yamagami M.: “Pairing eﬀects for collective excitations in weakly-bound nuclei”, 2nd GermanJapanese Workshop on Nuclear Structure and Astrophysics, Wako, Oct. (2006).
Motizuki Y. and Madokoro H.: “The late-time supernova evolution induced by anisotropic neutrino
radiation and the r-process environment (I)”, 2ndGerman-Japanese Workshop on Nuclear Structure
and Astrophysics, Wako, Oct. (2006).
Madokoro H. and Motizuki Y.: “The late-time supernova evolution induced by anisotropic neutrino radiation and the r-process environment (II) -Eﬀect
of ν interactions”, 2nd German-Japanese Workshop
on Nuclear Structure and Astrophysics, Wako, Oct.

- 350 -

(2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., Yamaguchi T.,
Yoneda A., Yoshida A., and YuLiang Z.: “Search for
the Heaviest Elements at RIKEN”, 6th International
Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006),(Advanced Science Research Center, Japan Atomic
Energy Agency), Tokaimura, Oct. (2006).
Motizuki Y., Makishima K., Takahashi K., IgarashiM., Bamba A., Nakai Y., Yano Y., Motoyama H.,
Kamiyama K., and Suzuki K.: “Antarctic ice as aprobe of historical supernovae”, The Extreme Universe in the Suzaku Era, Kyoto, Dec. (2006).
Motizuki Y. and Madokoro H.: “High entropy feasible for the r-process nucleosynthesis in 2-D hydrodynamical simulations of core-collapse supernovae(aposter paper)”, International conference on Twenty
Years after SN1987A, Waikoloa, USA, Feb. (2007).
(Domestic Conference)
山上雅之: “弱束縛系における一粒子波動関数の空間的構造変化：対相関と変形効果の競合”, 日本物理学会第60 回年次大会, (日本物理学会), 野田, 3 月 (2005).
山上雅之: “独立粒子描像の新展開”, 小規模ワークショッ
プ「RIBF に於ける γ 線核分光」, 和光, 2 月 (2006).
竹下英里, 青井考, 大田晋輔, 武内聡, 鈴木宏, 馬場秀忠,
Bishop S., 福井利晃, 井手口栄治, 家城和夫, 今井伸明,
岩崎弘典, 菅野祥子, 近藤洋介, 久保敏幸, 栗田和好,
日下健祐, 峯村俊行, 本林透, 中林彩, 中村隆司, 中尾
太郎, 新倉潤, 奥村俊文, 王惠仁, 大西健夫, 櫻井博儀,
下浦享, 須合亮平, 鈴木大介, 鈴木賢, 玉城充, 田中
鐘信, 栂野泰宏, 山田一成: “中性子過剰核 Cr 同位体の陽子非弾性散乱”, 日本物理学会第 61 回年次大会,
松山, 3 月 (2006).
道正新一郎, 下浦享, 岩崎弘典, 玉城充, 大田晋輔, 青井
考, 馬場秀忠, 岩佐直仁, 菅野祥子, 久保野茂, 栗田
和好, 峯村俊行, 本林透, 野谷将広, 王惠仁, 齋藤明登,
櫻井博儀, 竹下英里, 武内聡, 上坂明子, 柳澤善行, 吉田敦: “Single-particle states in 23 F by a proton transfer reaction”, 日本物理学会第 61 回年次大会, (日本物理学会), 松山, 3 月 (2006).
山上雅之: “Di-neutron correlation in neutron-rich Mg
isotopes”, 日本物理学会第 61 回年次大会, (日本物理学会), 松山, 3 月 (2006).
炭竃聡之, 長友傑, 小倉昌子, 岩越丈尚, 中島良樹, 藤原
裕樹, 松多健策, 南園忠則, 福田光順, 三原基嗣, 南園
啓, 山口貴之: “質量数 A=8 体系 β 崩壊における中間子交換効果”, 日本物理学会第 61 回年次大会, 松山, 3
月 (2006).
望月優子: “Investigating the origin of the elementswith RI-Beam Factory”, 教育セミナー (放射線業務従事者再教育), (東北原子力懇談会), 仙台, 4 月 (2006).
望月優子, 高橋和也, 馬場彩, 牧島一夫, 矢野安重, 五十嵐誠, 本山秀明, 神山孝吉, 鈴木啓助, 二河久子: “Solar
cycles of 1000 years ago discovered from Antarctic

ice core”, 日本地球惑星科学連合 2006 年大会, 千葉, 5
月 (2006).
山上雅之: “不安定核における “自発的対称性の破れ”の発現機構”, RIBF ミニワークショップ「Island of
Inversion に関する実験・理論の現状と今後の展望–
7 < Z < 20 領域中性子過剰核の低励起状態に関する検討会–」, (理研), 和光, 5 月 (2006).
武内聡, 青井考, 馬場秀忠, 福井利晃, 橋本佳子, 家城
和夫, 今井伸明, 岩崎弘典, 菅野祥子, 近藤洋介, 栗田
和好, 峯村俊行, 本林透, 中林彩, 中村隆司, 奥村俊文,
大西健夫, 大田晋輔, 櫻井博儀, 下浦享, 須合亮平, 鈴木
大介, 鈴木宏, 鈴木賢, 竹下英里, 玉城充, 田中鐘信,
栂野泰宏, 山田一成: “32 Mg と 34 Si の γ 線核分光”,
RIBF ミニワークショップ「Island of Inversion に関する実験・理論の現状と今後の展望–7 < Z < 20 領域
中性子過剰核の低励起状態に関する検討会–」, 和光, 5
月 (2006).
望月優子: “Investigating history of supernove and solar
activities with Antarctice ice core (invited)”, 星間物
質ワークショップ 2006, (北海道大学), 札幌, 7–8 月(2006).
金井保之, 中井陽一, 岩井良夫, 山崎泰規, 西尾和之, 益田
秀樹: “金属キャピラリー通過後の多価イオンからのAuger 電子”, 原子衝突研究協会第 31 回研究会, (原子衝突研究協会), 岡崎, 8 月 (2006).
中野祐司, 井上岳史, 近藤力, 東俊行, 畠山温, 中井陽一,
小牧研一郎, 山崎泰規, 高田栄一, 村上健: “結晶周期
場により形成された重イオンのドレスト状態”, 原子衝突研究協会第 31 回研究会, 岡崎, 8 月 (2006).
水野智也, 尾家隆司, 中井陽一, 土田秀次, 伊藤秋男:“MeV 重イオン衝突による二原子分子電離過程の配向依存性”, 原子衝突研究協会第 31 回研究会, 岡崎市,
8 月 (2006).
近藤力, 中野祐司, 真杉三郎, 村中友子, 東俊行, 畠山温,中井陽一, 小牧研一郎, 山崎泰規, 高田栄一, 村上健:
“Resonant coherent excitation under a channelingcondition in a thin crystal”, 原子衝突研究協会第 31回研究会, 岡崎, 8 月 (2006).
山上雅之: “重い不安定核における集団運動”, KEK 研
究会「現代の原子核物理–多様化し進化する原子核の描像–」, (高エネルギー加速器研究機構), つくば, 8 月(2006).
東俊行, 中野祐司, 井上正人, 近藤力, 畠山温, 小牧
研一郎, 中井陽一, 山崎泰規, 高田栄一, 村上健: “3次元コヒーレント共鳴励起を利用した 2 重共鳴”, 日本物理学会 2006 年秋季大会, 千葉, 9 月 (2006).
田中鐘信, 山口貴之, 鈴木健, 小沢顕, 相場健, 青井考,
泉川卓司, 稲福清彦, 岩佐直仁, 上坂明子, 大坪隆, 小林圭, 小室麻里, 近藤洋介, 篠田遼子, 篠原摩有子, 鈴木宏, 武内聡, 竹下英里, 武智麻耶, 栂野泰宏, 中島真平,
中林彩, 馬場秀忠, 橋爪祐平, 福田光順, 松山貴史, 道正
新一郎, 安野琢磨, 山田一成, 吉竹利織, 久保敏幸, 中村
隆司, 櫻井博儀, 本林透: “中性子過剰核 19,20,22 C の反応断面積測定”, 日本物理学会 2006 年秋季大会, 奈良, 9 月 (2006).
水野智也, 尾家隆司, 中井陽一, 土田秀次, 伊藤秋男: “高速重イオン荷電変換衝突に伴う CO 分子電離分解過- 351 -

程の分子配向依存性”, 日本物理学会 2006 年秋季大会,
千葉, 9 月 (2006).
中野祐司, 近藤力, 東俊行, 畠山温, 小牧研一郎, 中井
陽一, 山崎泰規, 高田栄一, 村上健: “結晶周期場により形成される重イオンのドレスト状態の観測”, 日本
物理学会 2006 年秋季大会, 千葉, 9 月 (2006).
中井陽一, 中野祐司, 池田時浩, 金井保之, 神原正, 福西
暢尚, 近藤力, 東俊行, 小牧研一郎, 山崎泰規: “チャネリング条件下におけるリチウム様 Fe イオンのコヒーレント共鳴励起：エネルギー付与との同時計測”, 日本
物理学会 2006 年秋季大会, 千葉, 9 月 (2006).
山上雅之, 清水良文: “不安定核における低エネルギー
回転運動”, 日本物理学会 2006 年秋季大会, 奈良, 9 月(2006).
山上雅之: “Continuum eﬀect for collective excitations
in deformed weakly-bound nuclei”, ミニワークショッ
プ「原子核平均場模型の現代的展開」, (会津大学), 会
津若松, 10 月 (2006).
山上雅之: “重い不安定核における新しい超流動性と集団運動”, RIBF ミニワークショップ「RIBF に於けるγ 分光実験 (II)」, (理研), 和光, 10 月 (2006).
望月優子: “Investigating the origin of the elementswith RI-Beam Factory”, 放射線業務従事者のための教育訓練講習会, (日本アイソトープ協会), 京都, 10 月
(2006).
五十嵐誠: “ドームふじ浅層コアに記録されている超新星
爆発の痕跡探査経過報告”, 極域気水圏・生物合同シンポジウム 2006, (国立極地研究所), 東京, 11 月 (2006).
田中鐘信, 山口貴之, 鈴木健, 小沢顕, 相場健, 青井考,
泉川卓司, 稲福清彦, 岩佐直仁, 上坂明子, 大坪隆, 小林圭, 小室麻里, 近藤洋介, 篠田遼子, 篠原摩有子, 鈴木宏, 武内聡, 竹下英里, 武智麻耶, 栂野泰宏, 中島真平,
中林彩, 馬場秀忠, 橋爪祐平, 福田光順, 松山貴史, 道正
新一郎, 安野琢磨, 山田一成, 吉竹利織, 久保敏幸, 中村
隆司, 櫻井博儀, 本林透: “22C 及び炭素同位体の反応断面積実験”, RIBF ミニワークショップ「反応断面積
で探る核構造」, (RIKEN), 和光, 11 月 (2006).
長友傑, 南園啓, 松多健策, Levy C. D., 三原基嗣, 炭竃
聡之, 小沢顕, 田岸義宏, 小倉昌子, 松宮亮平, 福田
光順, 山口充孝, Behr J. A., Jackson K. P., 藤原弘樹,
安野琢磨, 太田寛史, 橋爪祐平, 千葉明子, 南園忠則:“ベータ NMR 法を用いた質量数 20 体系の β 線角度分布の精密測定による第二種核子流の探索”, 平成
18 年度京都大学原子炉実験所専門研究会「原子核プ
ローブ生成とそれを用いた物性研究 (II)」, 大阪府熊取, 11–11 月 (2006).
望月優子: “Investigating the origin of the elementswith RI-Beam Factory”, 埼玉大学原子核理論研究室
セミナー, さいたま, 12 月 (2006).
望月優子: “The Universe, the Earth, and we, humanbeings”, 埼玉大学理学部物理学科学術講演会, さいた
ま, 1 月 (2007).
望月優子, 間所秀樹: “The Late-time supernova evolution induced by anisotropic neutrino radiation andthe r-process environment”, 研究会「超新星を舞台とする高エネルギー物理現象」, (東京大学), 東京, 2 月(2007).

間所秀樹, 望月優子: “非等方ニュートリノ輻射を伴う重力崩壊型超新星爆発の後期時間発展と r プロセスの環境”, 日本天文学会 2007 年春季年会, 平塚, 3 月 (2007).
望月優子: “Investigating history of supernove with
Antarctice ice core (invited)”, CAWSES/IHY workshop, (日本学術会議国際対応分科会), 名古屋, 3 月(2007).
望月優子, 間所秀樹: “High entropy feasible for the
r-process nucleosynthesis in a 2-D hydrodynamical
simulation of core-collapse supernovae”, 国立天文台
ワークショップ「R プロセス元素組成の統合的理解：
量子ビームでさぐる宇宙進化の理解を目指して」, 三
鷹, 3 月 (2007).
望月優子, 間所秀樹: “The Late-time supernova evolution induced by anisotropic neutrino radiation andthe r-process environment”, 日本物理学会 2007 年春
季大会, 八王子, 3 月 (2007).

Superheavy Element Lab.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Mazzocco M., Signorini C., Romoli M., De Francesco
A., Dipietro M., Vardaci E., Yoshida K., Yoshida A.,
Bonetti R., De Rosa A., Glodariu T., Guglielmentti
A., Inglima G., La Commara M., Martin B.,
Pierroutsakou D., Sandoli M., Soramel F., Stroe L.,
Kanungo R., Khai N., Motobayashi T., Nomura T.,
Ishikawa T., Ishiyama H., Jeong S., Miyatake H.,
Tanaka M., Sugai I., and Watanabe Y.: “Scattering of 11 Be halo nucleus from 209 Bi at the Coulomb
barrier”, Eur. Phys. J. A 28, 295–299 (2006). ＊Asai M., Tsukada K., Ichikawa S., Sakama M., Haba
H., Nishinaka I., Nagame Y., Goto S., Kojima Y.,
Oura Y., and Shibata M.: “Alpha decay of 238Cm
and the new isotope 237Cm”, Phys. Rev. C 73,
067301-1–067301-4 (2006). ＊Mutou R., Chiba J., Enyo H., Fukao Y., Funahashi
H., Hamagaki H., Ieiri M., Ishino M., Kanda H.,
Kitaguchi M., Mihara S., Miwa K., Miyashita T.,
Murakami T., Nakura T., Naruki M., Ozawa K.,
Sakuma F., Sasaki O., Sekimoto M., Tabaru T.,
Tanaka K., Togawa M., Yamada S., Yokkaichi S.,
and Yoshimura Y.: “Evidence for in-medium modiﬁcation of the φ meson at normal nuclear density”,
Phys. Rev. Lett. 98, No. 4, pp. 042501-1–042501-4(2007). ＊Haba H., Tsukada K., Asai M., Toyoshima A., Ishii
Y., Toume H., Sato T., Nishinaka I., Ichikawa
T., Ichikawa S., Nagame Y., Sato W., Matsuo K.,
Kitamoto Y., Tashiro T., Shinohara A., Saito J.,
Ito M., Ikezawa T., Sakamaki M., Goto S., Kudo
H., Kikunaga H., Arai M., Kamataki S., Yokoyama
A., Akiyama K., Sueki K., Oura Y., Schaedel M.,
Bruechle W., and Kratz J. V.: “Extraction behavior of rutherfordium into tributylphosphate from hy-- 352 -

drochloric acid”, Radiochim. Acta 95, 1–6 (2007). ＊金山洋介, 羽場宏光, 榎本秀一, 天野良平: “コルヒチンによる 24 Na, 28 Mg, 43 K, 47 Ca, 48 V, 67 Cu 嗅覚輸送阻害効果の検討”, 微量栄養素研究 23, 84–88 (2006).
＊(Others)
Nagame Y., Akiyama K., Asai M., Goto S., Haba
H., Hirata M., Ishii Y., Nishinaka I., Tome H.,
Toyoshima A., and Tsukada K.: “Chemical studiesof the transactinide elements at JAEA”, AIP Conf.
Proc. 865, 165–172 (2006).
Asai M., Tsukada K., Haba H., Toyoshima A., Ishii Y.,
Nagame Y., Nishinaka I., Ichikawa T., Kojima Y.,
and Sueki K.: “Alpha-gammma coincidence spectroscopy of 255No”, JAEA-Review 2006, No. 29,
pp. 41–42 (2006).
Haba H., Tsukada K., Asai M., Toyoshima A., Ishii
Y., Tome Y., Sato T., Nishinaka I., Ichikawa T.,
Ichikawa S., Nagame Y., Sato W., Matsuo K.,
Kitamoto Y., Tashiro T., Shinohara A., Saito J.,
Ito M., Ikezawa T., Sakamaki M., Goto S., Kudo
H., Kikunaga H., Arai M., Kamataki S., Yokoyama
A., Akiyama K., Sueki K., Oura Y., Schaedel M.,
Bruechle W., and Kratz J. V.: “Extraction behaviorof Rf into tributylphosphate from hidrochloric acid”,
JAEA-Review 2006, No. 29, pp. 57–58 (2006).
Ishii Y., Miyashita S., Mori T., Suganuma H., Tashiro
T., Sakamaki M., Goto S., Tome Y., ToyoshimaA., Haba H., Akiyama K., Asai M., Nishinaka I.,
Tsukada K., Oura Y., and Nagame Y.: “Cationexchange behavior of Rf in HNO3/HF mixed solution system”, JAEA-Review 2006, No. 29, pp. 59–60(2006).
Tsukada K., Toyoshima A., Haba H., Asai M.,
Akiyama K., Ishii Y., Tome Y., Nishinaka I., SatoT., Ichikawa S., Nagame Y., Yaita T., Goto S.,
Ikezawa T., Sato W., Matsuo K., Kitamoto Y.,
Tashiro T., Yokoyama A., Arai M., Sakama M.,
Oura Y., Sueki K., Shinohara A., and Kudo H.:“Chloride complex formation of Rf in HCl and 3 OH
mixed solution”, JAEA-Review 2006, No. 29, pp.
61–62 (2006).
[Book・Proc.](Others)
Nagame Y., Haba H., Tsukada K., Asai M., Toyoshima
A., Akiyama T., Kaneko T., Hirai T., Goto
S., Hirata M., Nishinaka I., and Ichikawa S.:“Few atom chemistry of the transactinide element
rutherfordium (Rf)”, Proceedings of the International Conference on Applications of High Precision
Atomic and Nuclear Methods, 2-6 September 2002,
Neptun, Romania, Neptun, Romania, 2002–9, IFINHH, Bucharest, pp. 334–343 (2005).
Nagame Y., Asai M., Haba H., Hirata M., Ishii
Y., Nishinaka I., Toyoshima A., and Tsukada K.:“Aqueous Chemistry of the Transactinide Element,
Rutherfordium (Rf)”, Lecture Series on Computerand Computational Sciences Volume 7, Brill Academic Publishers, Leiden, pp. 927–930 (2006).
Oral Presentations(International Conference etc.)
Tsukada K., Toyoshima A., Haba H., Asai M.,
Akiyama K., Ishii Y., Kaneko T. S., Nishinaka I.,
Nagame Y., Sueki K., Ito M., Saito J., Goto S., Kudo
H., and Oura Y.: “Chloride complex formation of
Rf in HCl and CH3OH mixed solution”, Actinides
2005, (The University of Manchester), Manchester,
UK, July (2005).
Kambara T., Kanai Y., Kojima T., Nakai Y., Yoneda
A., and Yamazaki Y.: “Elastic waves from fastheavy-ion irradiation on solids”, 18th International
Acoustic Emission Symposium, Sagamihara, July
(2006).
Kikunaga H., Haba H., Kaji D., Sato N., Akiyama T.,
Morimoto K., Yoneda A., Morita K., Takabe T., Ooe
K., Shinohara A., Suzuki D., Nanri T., YamazakiI., and Yokoyama A.: “Development of a gas-jet
transport system coupled to GARIS for heavy element chemistry”, 5th Workshop on Recoil Separator
for Superheavy Element Chemistry (TASACA06),(GSI), Garching, Germany, Sept. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., YamaguchiT., Yoneda A., Yoshida A., and YuLiang Z.: “Experiments on Synthesis of the Heaviest Elements at
RIKEN (SHE and FFD)”, Tours Symposium on Nuclear Physics VI (TOURS 2006), (Konan University), Tours, France, Sept. (2006).
Haba H., Kaji D., Kikunaga H., Akiyama T., SatoN., Morimoto K., Yoneda A., Morita K., TakabeT., Tashiro Y., Kitamoto Y., Matsuo K., Saika D.,
Ooe K., Kuribayashi T., Yoshimura T., Shinohara
A., and Toyoshima A.: “Superheavy Element Chemistry at RIKEN: Present Status and Perspectives”,
Tours Symposium on Nuclear Physics VI (TOURS
2006), (Konan University), Tours, France, Sept.
(2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., YamaguchiT., Yoneda A., Yoshida A., and YuLiang Z.: “Experiments on Synthesis of the Heaviest Elements
at RIKEN Status and Perspectives”, Workshop on
the Atomic Properties of the Heaviest Elements:
Towards the Island of Stability, (LMU-Muenchen),Germany, Chiemsee, Sept. (2006).
Toyoshima A., Tsukada K., Asai M., Ishii Y.,
Nishinaka I., Sato T., Hirata M., Nagame Y., Haba
H., Sato W., Tani Y., Hasegawa H., Matsuo K.,
Saika D., Kitamoto Y., Shinohara A., Goto S.,- 353 -

Ito M., Saito J., Kudo H., Akiyama K., Sueki K.,
Yokoyama A., Oura Y., Schaedel M., Bruechle W.,
and Kratz J. V.: “Fluoride Complexation Study ofRutherfordium at JAEA”, Workshop on the Atomic
Properties of the Heaviest Elements: Towards the Island of Stability, (LMU Muenchen), Chiemsee, Germany, Sept. (2006).
Haba H., Kaji D., Kikunaga H., Akiyama T., SatoN., Morimoto K., Yoneda A., Morita K., TakabeT., Tashiro Y., Kitamoto Y., Matsuo K., Saika D.,
Ooe K., Kuribayashi T., Yoshimura T., Shinohara
A., and Toyoshima A.: “Startup of Heavy Element
Chemistry in RIKEN”, Workshop on the Atomic
Properties of the Heaviest Elements: Towards the Island of Stability, (LMU Muenchen), Chiemsee, Germany, Sept. (2006).
Ishii Y., Toume H., Toyoshima A., Asai M., Nishinaka
I., Tsukada K., Nagame Y., Tashiro T., Shinohara
A., Sakamaki M., Goto S., Kudo H., Akiyama K.,
Haba H., Oura Y., Miyashita S., Mori T., andSuganuma H.: “A cation-exchange study of ﬂuoride
complexation of rutherfordium (Rf) in HNO3/HF
mixed solution system”, 6th International Symposium on Advanced Science Research: Frontiersof Nuclear and Radiochemistry (ASR2006), (Advanced Science Research Center, Japan Atomic Energy Agency), Tokaimura, Oct. (2006).
Kasamatsu Y., Toyoshima A., Toume H., Tsukada
K., Haba H., and Nagame Y.: “Adsorption of Nb,
Ta and Pa on anion exchangers in HF/HNO3 media: Model experiments for the chemical study ofDubnium (Db)”, 6th International Symposium on
Advanced Science Research: Frontiers of Nuclear
and Radiochemistry (ASR2006), (Advanced Science
Research Center, Japan Atomic Energy Agency),
Tokaimura, Oct. (2006).
Tsukada K., Toyoshima A., Haba H., Asai M.,
Akiyama K., Ishii Y., Tome H., Nishinaka I., Kaneko
T. S., Ichikawa S., Nagame Y., Yaita T., Goto
S., Ikezawa T., Sato W., Matsuo K., KitamotoY., Tashiro T., Yokoyama A., Arai M., Sakama
M., Oura Y., Sueki K., Shinohara A., and Kudo
H.: “Chloride complex formation of Rf in HCl andCH3OH mixed solution”, 6th International Symposium on Advanced Science Research: Frontiersof Nuclear and Radiochemistry (ASR2006), (Advanced Science Research Center, Japan Atomic Energy Agency), Tokaimura, Oct. (2006).
Haba H., Kikunaga H., Kaji D., Sato N., Akiyama T.,
Morimoto K., Yoneda A., Morita K., Takabe T., Ooe
K., Shinohara A., Suzuki D., Nanri T., Yamazaki I.,
and Yokoyama A.: “Development of a gas-jet transport system coupled to the RIKEN gas-ﬁlled recoil
ion separator GARIS for superheavy element chemistry”, 6th International Symposium on Advanced
Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006), (Advanced Science ResearchCenter, Japan Atomic Energy Agency), Tokaimura,
Oct. (2006).
Toyoshima A., Kasamatsu Y., Tsukada K., Haba
H., Shinohara A., and Nagame Y.: “Developmentof an electrochemistry apparatus for an atom-at-atime chemistry”, 6th International Symposium on
Advanced Science Research: Frontiers of Nuclear
and Radiochemistry (ASR2006), (Advanced Science
Research Center, Japan Atomic Energy Agency),
Tokaimura, Oct. (2006).
Akiyama K., Haba H., Tsukada K., Asai M., Sueki
K., Toyoshima A., Nagame Y., and Katada M.:“Metallofullerenes encaging californium”, 6th International Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry(ASR2006), (Advanced Science Research Center,
Japan Atomic Energy Agency), Tokaimura, Oct.
(2006).
Kaji D., Haba H., Kikunaga H., Morimoto K., Yoneda
A., Akiyama T., Ooe K., Nanri T., Sato N.,
Shinohara A., Suzuki D., Takabe T., Yamazaki I.,
Yokoyama A., and Morita K.: “Optimazation of a
gas-ﬁlled recoil separator GARIS for the chemistry ofsuperheavy elements”, 6th International Symposium
on Advanced Science Research: Frontiers of Nuclear
and Radiochemistry (ASR2006), (Advanced Science
Research Center, Japan Atomic Energy Agency),
Tokaimura, Oct. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., Yamaguchi T.,
Yoneda A., Yoshida A., and YuLiang Z.: “Search for
the Heaviest Elements at RIKEN”, 6th International
Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006),(Advanced Science Research Center, Japan Atomic
Energy Agency), Tokaimura, Oct. (2006).
Takabe T., Saika D., Matsuo K., Tashiro T., Ooe
K., Kuribayashi T., Yoshimura T., ToyoshimaA., Kikunaga H., Kaji D., Haba H., Kudo H.,
Mitsugashira T., and Shinohara A.: “Studies on theheavy element productions at RIKEN for chemical
characterization of seaborgium”, 6th International
Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006),(Advanced Science Research Center, Japan Atomic
Energy Agency), Tokaimura, Oct. (2006).
Toyoshima A., Kasamatsu Y., Tsukada K., Haba H.,
Asai M., Ishii Y., Toume H., Kaneko T. S., Nishinaka
I., Nagame Y., Goto S., Ishiyama T., Sakamaki M.,
Kudo H., Akiyama K., Oura Y., Kikunaga H., Ooe
K., Kuribayashi T., Shinohara A., and Yokoyama
A.: “TOPO reversed-phase extraction behabior ofrutherfordium in HCl solutions”, 6th International
Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006),- 354 -

(Advanced Science Research Center, Japan Atomic
Energy Agency), Tokaimura, Oct. (2006).
(Domestic Conference)
北本優介, 雑賀大輔, 松尾啓司, 高部智正, 田代祐基, 大江一弘, 栗林隆宏, 佐藤渉, 高橋成人, 吉村崇, 羽場宏光,
榎本秀一, 三頭聰明, 篠原厚: “金属-配位子間相互作用を利用した 3 価アクチノイドのキャピラリー電気泳動分離”, 日本化学会第 86 春季年会, (日本化学会), 船橋, 3 月 (2006).
石井康雄, 菅沼英夫, 羽場宏光, 秋山和彦, 當銘勇人, 豊嶋
厚史, 浅井雅人, 塚田和明, 永目諭一郎: “超重元素ラザホージウムを模擬した同族元素 Zr，Hf の硝酸/フッ化水素酸系における陽イオン交換挙動”, 日本化学会
第 86 春季年会, (日本化学会), 船橋, 3 月 (2006).
羽場宏光, 加治大哉, 高部智正, 秋山隆宏, 森本幸司, 森田
浩介: “気体充填型反跳分離装置を前段分離装置として用いた新しい超重元素化学分析装置の開発”, 日本化学会第 86 春季年会, (日本化学会), 船橋, 3 月 (2006).
高部智正, 北本優介, 雑賀大輔, 松尾啓司, 田代祐基, 大江一弘, 栗林隆宏, 吉村崇, 羽場宏光, 加治大哉, 篠原厚:
“理研 AVF サイクロトロンにおける重元素合成シス
テムの整備と化学研究のためのノーベリウム同位体の製造”, 日本化学会第 86 春季年会, (日本化学会), 船橋,
3 月 (2006).
塚田和明, 豊嶋厚史, 羽場宏光, 浅井雅人, 秋山和彦, 石井康雄, 當銘勇人, 西中一朗, 佐藤哲也, 市川隆敏, 市川進一, 平田勝, 永目諭一郎, 矢板毅, 後藤真一, 坂牧
雅巳, 池沢孝明, 佐藤渉, 松尾啓司, 北本優介, 田代
祐基, 横山明彦, 新井理太, 鎌滝真次, 阪間稔, 大浦
泰嗣, 末木啓介, 篠原厚, 工藤久昭: “超重元素ラザホー
ジウムの塩化物錯体形成”, 日本化学会第 86 春季年会,(日本化学会), 船橋, 3 月 (2006).
加治大哉, 羽場宏光, 森本幸司, 秋山隆宏, 森田浩介, 佐藤望, 高部智正: “シーボギウム (Sg) の化学研究へ向けた 232Th+40Ar 反応による Sg 同位体の探索”, 日本
化学会第 86 春季年会, (日本化学会), 船橋, 3 月 (2006).
豊嶋厚史, 羽場宏光, 塚田和明, 浅井雅人, 秋山和彦, 石井康雄, 當銘勇人, 西中一朗, 佐藤哲也, 市川隆敏, 永目
諭一郎, 佐藤渉, 松尾啓司, 北本優介, 田代祐基, 篠原厚, 池沢孝明, 坂牧雅巳, 後藤真一, 工藤久昭, 新井理太, 鎌滝真次, 横山明彦, 大浦泰嗣, 末木啓介: “塩酸溶液系におけるラザホージウムの TBP 逆相抽出ク
ロマトグラフィー”, 日本化学会第 86 春季年会, (日本化学会), 船橋, 3 月 (2006).
金山洋介, 羽場宏光, 榎本秀一, 天野良平: “24 Na, 28 Mg,
43
K, 47 Ca, 48 V, 67 Cu 鼻腔投与におけるコルヒチンの嗅覚輸送阻害効果の検討”, 第 23 回微量栄養素研究会
シンポジウム, 京都, 6 月 (2006).
金山洋介, 榎本秀一, 羽場宏光, 天野良平: “Brain Delivery of Monovalent Metal Cations via Olfactory Pathway”, 第 16 回金属の関与する生体関連反応シンポジ
ウム (SRM 2006)「生体超分子システムと金属」, (日本薬学会), 東京, 6 月 (2006).
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,
木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,

後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
笠松良崇, 豊嶋厚史, 當銘勇人, 塚田和明, 羽場宏光, 永目
諭一郎: “希フッ化水素酸系における Nb, Ta, Pa の陰イオン交換挙動”, 2006 日本放射化学会年会・第 50 回
放射化学討論会, (日本放射化学会), 水戸，東海村, 10
月 (2006).
石井康雄, 當銘勇人, 豊嶋厚史, 浅井雅人, 西中一朗, 塚田
和明, 永目諭一郎, 宮下直, 森友隆, 菅沼英夫, 田代
祐基, 篠原厚, 坂牧雅巳, 後藤真一, 工藤久昭, 羽場
宏光, 秋山和彦, 大浦泰嗣: “Rf の HNO3/HF における陽イオン交換挙動 (II)”, 2006 日本放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月 (2006).
羽場宏光, 加治大哉, 高部智正, 秋山隆宏, 森本幸司, 米田
晃, 森田浩介: “理研気体充填型反跳分離装置 GARIS
を前段分離装置として用いた新しい重元素化学分析装
置の開発”, 2006 日本放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月
(2006).
豊嶋厚史, 笠松良崇, 塚田和明, 羽場宏光, 篠原厚, 永目
諭一郎: “単一原子の電気化学的研究に向けた電解セルの開発”, 2006 日本放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月
(2006).
秋山和彦, 羽場宏光, 塚田和明, 浅井雅人, 豊嶋厚史, 矢板毅, 末木啓介, 永目諭一郎: “EXAFS を用いた Zr，Hfの塩酸系 TBP 抽出における錯体構造に関する研究”,2006 日本放射化学会年会・第 50 回放射化学討論会,(日本放射化学会), 水戸，東海村, 10 月 (2006).
高部智正, 雑賀大輔, 松尾啓司, 田代祐基, 大江一弘, 栗林
隆宏, 吉村崇, 豊嶋厚史, 菊永英寿, 加治大哉, 羽場
宏光, 工藤久昭, 三頭聰明, 篠原厚: “理研におけるシー
ボーギウム化学研究に向けた重元素合成”, 2006 日本
放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月 (2006).
菊永英寿, 羽場宏光, 加治大哉, 佐藤望, 森本幸司, 米田
晃, 森田浩介, 高部智正, 大江一弘, 篠原厚, 鈴木大介,
南里朋洋, 山崎逸郎, 横山明彦: “238U(22Ne,5n) 反応によって製造された 255No の GARIS による分離分
析：GARIS を前段分離装置として用いた超重元素化学研究に向けて”, 2006 日本放射化学会年会・第 50 回
放射化学討論会, (日本放射化学会), 水戸，東海村, 10
月 (2006).
中嶋啓二, 笠松良崇, 佐藤渉, 菊永英寿, 高宮幸一, 三頭
聰明, 中西孝, 大槻勤, 篠原厚: “229m Th の可視・紫外・赤外領域における脱励起光測定”, 2006 日本放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月 (2006).
田代祐基, 雑賀大輔, 北本優介, 松尾啓司, 高部智正, 栗林
隆宏, 大江一弘, 吉村崇, 佐藤渉, 高橋成人, 豊嶋厚史,
羽場宏光, 篠原厚: “複線式マイクロチップを用いた
No2+迅速溶媒抽出”, 2006 日本放射化学会年会・第50 回放射化学討論会, (日本放射化学会), 水戸，東海
村, 10 月 (2006).
大江一弘, 栗林隆宏, 高部智正, 田代祐基, 北本優介, 雑賀- 355 -

大輔, 松尾啓司, 高橋成人, 吉村崇, 高宮幸一, 柴田
誠一, 羽場宏光, 榎本秀一, 篠原厚: “極低濃度タング
ステンの溶媒抽出挙動と電解酸化還元反応”, 2006 日
本放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月 (2006).
豊嶋厚史, 笠松良崇, 塚田和明, 羽場宏光, 浅井雅人,
石井康雄, 當銘勇人, 金子 (哲也) 佐藤, 西中一朗, 永目
諭一郎, 後藤真一, 石山剛, 坂牧雅巳, 工藤久昭, 秋山
和彦, 大浦泰嗣, 菊永英寿, 大江一弘, 栗林隆宏, 篠原厚, 末木啓介, 横山明彦: “塩酸溶液系におけるラザ
ホージウムの TOPO 逆相抽出クロマトグラフ挙動”,
2006 日本放射化学会年会・第 50 回放射化学討論会,(日本放射化学会), 水戸，東海村, 10 月 (2006).
羽場宏光: “理化学研究所における超重元素化学研究”,
タンデム領域の重イオン科学研究会 (2006), (JAEA，
KEK), 東海村, 12 月 (2006).

SCRIT Team
Oral Presentations(Domestic Conference)
池沢英二, 加治大哉, 加瀬昌之, 上垣外修一, 中川孝秀,
坂本成彦, 奥野広樹, 稲辺尚人, 福西暢尚, 込山美咲,
木寺正憲, 日暮祥英, 龍頭啓充, 小原重夫, 藤巻正樹,
若杉昌徳, 長瀬誠, 影山正, 横内茂, 渡邉環, 米田晃,
後藤彰, 矢野安重: “超重元素探索実験のための理研重イオンリニアック運転”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
Big RIPS Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Mazzocco M., Signorini C., Romoli M., De Francesco
A., Dipietro M., Vardaci E., Yoshida K., Yoshida A.,
Bonetti R., De Rosa A., Glodariu T., Guglielmentti
A., Inglima G., La Commara M., Martin B.,
Pierroutsakou D., Sandoli M., Soramel F., Stroe L.,
Kanungo R., Khai N., Motobayashi T., Nomura T.,
Ishikawa T., Ishiyama H., Jeong S., Miyatake H.,
Tanaka M., Sugai I., and Watanabe Y.: “Scattering of 11 Be halo nucleus from 209 Bi at the Coulomb
barrier”, Eur. Phys. J. A 28, 295–299 (2006). ＊Kameda D., Ueno H., Asahi K., Takemura M.,
Shirahama A., Haseyama T., Uchida M., Shimada
K., Nagae D., Kijima G., Arai T., Takase K., Suda
S., Inoue T., Murata J., Kawamura H., Kobayashi
Y., Watanabe H., and Ishihara M.: “Nuclear moments of neutron-rich 32 Al”, J. Phys.: Con. Ser. 49,
138–139 (2006). ＊Nakamura T., Wada M., Okada K., Ishida Y.,
Takamine A., Yamazaki Y., Kambara T., Kanai
Y., Kojima T., Nakai Y., Oshima N., Yoshida A.,
Kubo T., Katayama I., Lioubimov V., Wollnik H.,
Varentsov V., and Schuessler H. A.: “Laser spectroscopy of 7,10 Be+ in an online ion trap”, Phys.

Rev. A 74, 052503-1–052503-5 (2006). ＊Suda K., Okamura H., Uesaka T., Nishikawa J.,
Kumasaka H., Suzuki R., Sakai H., Tamii A.,
Ohnishi T., Sekiguchi K., Yako K., Sakoda S.,
Kato H., Hatano M., Maeda Y., Saito T., IshidaT., Sakamoto N., Sato Y., Hatanaka K., Wakasa
T., and Kamiya J.: “Absolute Calibration of theDeuteron Beam Polarization at Intermediate Ener α)10 B∗ [2+ ] Reaction”, Nuclear Ingies via the 12 C(d,struments and Methods in Physics Research A 572,
No. Issue 2, pp. 745–753 (2007). ＊Oral Presentations(International Conference etc.)
Kameda D., Asahi K., Ueno H., Shirahama A.,
Watanabe H., Haseyama T., Kobayashi Y., UchidaM., Shimada K., Nagae D., Kato G., Emori S.,
Kijima G., Takemura M., Arai T., Oshima S.,
Tsukui M., Yagi E., Kubo T., Yoshida A., andIshihara M.: “Production of spin-polarized RI
beams via projectile fragmentation and the application to nuclear moment measurements”, 11th International Workshop on Polarized Sources and Targets (PST05), (RIKEN and The Center for Nuclear
Study (CNS) ), Tokyo, Nov. (2005).
Kameda D., Asahi K., Ueno H., Shirahama A.,
Haseyama T., Watanabe H., Uchida M., Shimada
K., Nagae D., Takemura M., Arai T., Kijima G.,
Takase K., Suda S., Inoue T., Kobayashi Y., Yagi
E., Kubo T., Yoshida A., and Ishihara M.: “Nuclear
moments of neutron-rich 32Al(Z = 11, N = 19)”, International Symposium on Structure of Exotic Nuclei and Nuclear Forces (SENUF06), (The Center for
Nuclear Study (CNS)), Tokyo, Mar. (2006).
Kameda D., Ueno H., Asahi K., Shirahama A.,
Haseyama T., Watanabe H., Uchida M., Nagae D.,
Shimada K., Takemura M., Arai T., Takase K.,
Inoue T., Kato G., Kijima G., Emori S., Suda S.,
Tsukui M., Murata J., Kawamura H., Kobayashi Y.,
Yagi E., Kubo T., and Ishihara M.: “Nuclear moment measurements using spin-polarized RI beams
via projectile fragmentation: Recent results and theprospect in RIBF”, International Workshop on “Nuclear Physics with RIBF”, Wako, Mar. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., YamaguchiT., Yoneda A., Yoshida A., and YuLiang Z.: “Experiments on Synthesis of the Heaviest Elements at
RIKEN (SHE and FFD)”, Tours Symposium on Nuclear Physics VI (TOURS 2006), (Konan University), Tours, France, Sept. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., Yamaguchi- 356 -

T., Yoneda A., Yoshida A., and YuLiang Z.: “Experiments on Synthesis of the Heaviest Elements
at RIKEN Status and Perspectives”, Workshop on
the Atomic Properties of the Heaviest Elements:
Towards the Island of Stability, (LMU-Muenchen),Germany, Chiemsee, Sept. (2006).
Kameda D., Asahi K., Ueno H., Shirahama A.,
Haseyama T., Watanabe H., Uchida M., Nagae
D., Shimada K., Takemura M., Arai T., Takase
K., Inoue T., Suda S., Kobayashi Y., Murata J.,
Kawamura H., and Ishihara M.: “Nuclear momentmeasurements of neutron-rich Al isotopes using spinpolarized RI beams: Determination of the boundary of the “island of inversion””, 17th International
Spin Physics Symposium (SPIN2006), (Kyoto University), Kyoto, Oct. (2006).
Morita K., Morimoto K., Kaji D., Akiyama T., Goto
S., Haba H., Ideguchi E., Katori K., Kikunaga H.,
Koura H., Kudo H., Ohnishi T., Ozawa A., Suda T.,
Sato N., Sueki K., Tokanai F., Xu H., Yamaguchi T.,
Yoneda A., Yoshida A., and YuLiang Z.: “Search for
the Heaviest Elements at RIKEN”, 6th International
Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006),(Advanced Science Research Center, Japan Atomic
Energy Agency), Tokaimura, Oct. (2006).
Detector Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Ariyoshi S., Otani C., Dobroiu A., Matsuo H., Sato H.,
Taino T., Kawase K., and Shimizu H.: “Superconducting Detector Array for Terahertz Imaging Applications”, Jpn. J. Appl. Phys. Pt.2 45, No. 37, pp.
L1004–L1006 (2006). ＊Oral Presentations(International Conference etc.)
Ariyoshi S., Otani C., Dobroiu A., Matsuo H., Sato H.,
Taino T., Kawase K., and Shimizu H.: “Terahertz
Imaging with an STJ-based Linear Array Detector(Invited Oral)”, Applied Superconductivity Conference 2006 (ASC 2006), Seattle, USA, Aug.–Sept.
(2006).
Otani C., Ariyoshi S., Taino T., Dobroiu A., ShibuyaT., Sato H., Shimizu H., and Kawase K.: “Development of Terahertz Imaging Detectors using Superconducting Tunnel Junctions”, International Conference on Mesoscopic Superconductivity and Magnetism (MesoSuperMag 2006), (Argonne National
Laboratory), Chicago, USA, Aug.–Sept. (2006).
Ariyoshi S., Otani C., Dobroiu A., Matsuo H., Sato
H., Taino T., Kawase K., and Shimizu H.: “THz
Imaging with a Linear Array Detector based on Superconducting Tunnel Junctions”, 2006 Joint 31st

International Conference on Infrared and Millimeter
Waves and 14th International Conference on Terahertz Electronics (IRMMW-THz2006), (Shanghai
Institute of Technical Physics (SITP) ), Shanghai,
China, Sept. (2006).
Otani C., Ariyoshi S., Taino T., Myoren H., Sato
H., Shimizu H., Takada S., and Kawase K.: “Terahertz Detectors using Superconducting Tunnel Junctions (Invited)”, 19th International Symposium on
Superconductivity (ISS 2006), (International Superconductivity Technology Center (ISTEC)), Nagoya,
Oct.–Nov. (2006).
Taino T., Ishii H., Yoshimura S., Otani C., AriyoshiS., Myoren H., Kawase K., Shibuya T., Sato
H., Shimizu H., and Takada S.: “Terahertz
electromagnetic-waves detector using Nb-based superconducting tunnel junction on LiNb03 substrateabsorber”, 19th International Symposium on Superconductivity (ISS 2006), (ISTEC (International Superconductivity Technology Center)), Nagoya, Oct.–
Nov. (2006).
Otani C., Ariyoshi S., Taino T., Sato H., Shimizu H.,
and Kawase K.: “Radiation Detectors using Superconducting Tunnel Junctions (invited lecture)”, 14th
International Symposium on Laser Spectroscopy(SOLS 2006), (KAERI), Daejeon, Korea, Nov.
(2006).
Otani C., Ariyoshi S., Taino T., Dobroiu A., Sato H.,
Shimizu H., and Kawase K.: “Development of Terahertz Detectors using Superconducting Tunnel Junctions (invited)”, 2nd CREST Nano-Virtual-Labs
Joint Workshop on Superconductivity (NVLS2006),
Kyoto, Dec. (2006).
Ariyoshi S., Otani C., Dobroiu A., Matsuo H., Taino
T., Sato H., and Shimizu H.: “STJ-based direct detector array for terahertz imaging applications”, 7thWorkshop on Submillimeter-Wave Receiver Technologies in Eastern Asia/Workshop on the Development of Low-Noise Receiver Technology at Millimeter Waves and Terahertz Frequencies, (Nobeyama
Radio Observatory), Sakai, Jan. (2007).
(Domestic Conference)
大谷知行, 有吉誠一郎, 佐藤広海, 川瀬晃道, 田井野徹,
清水裕彦: “超伝導トンネル (STJ) 素子によるテラヘ
ルツ波アレイ検出器の開発とイメージング（招待講演）”, 応用物理学会超伝導分科会第 33 回研究会「高感度分析・分光技術のための超伝導検出器」, (超伝導工学研究所), 東京, 6 月 (2006).
有吉誠一郎, 大谷知行, Dobroiu A., 松尾宏, 田井野徹,
佐藤広海, 清水裕彦: “スペース天文応用を目指したサ
ブミリ波帯 STJ 検出器アレイの開発”, 第 7 回宇宙科
学シンポジウム, (宇宙航空研究開発機構宇宙科学研究本部), 相模原, 12 月 (2006).
有吉誠一郎, 大谷知行, Dobroiu A., 松尾宏, 佐藤広海,
田井野徹, 川瀬晃道, 清水裕彦: “超伝導検出器アレイを用いたテラヘルツイメージング”, 電子情報通信学
会電子デバイス研究会 2006 年度月間研究会（12 月）,- 357 -

東京, 12 月 (2006).

Industrial Cooperation Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Takeichi H., Koyama S., Matani A., and Cichocki
A.: “Speech comprehension assessed by electroencephalography: a new method using m-sequence
modulation”, Neurosci. Res. 57, No. 2, pp. 314–318(2007). ＊(Others)
竹市博臣, 小山幸子, 眞溪歩, Cichocki A.: “m 系列変調法による脳波計測：談話理解を例として”, 物性研究
87, No. 4, pp. 608–610 (2007).
Oral Presentations(International Conference etc.)
Takeichi H. and Koyama S.: “A study of scene perception and perceptual interaction by multiple bistability: shading-lighting”, Cognitive Neuroscience Society 2006 Annual Meeting, San Francisco, USA, Apr.
(2006).
Koyama S., Toyomaki A., Matsumoto H., Matsui M.
F., Takeichi H., and Morotomi T.: “Auditory eventrelated brain potentials elicited by short gaps embedded in a continuous sound and by brief tones: adevelopmental study”, Cognitive Neuroscience Society 2006 Annual Meeting, San Francisco, USA, Apr.
(2006).
Takeichi H., Koyama S., Kimura M., Matsumoto H.,
Inoue Y., and Morotomi T.: “Visually evoked brain
potentials associated with volumetric completion”,
36th Annual Meeting of Society for Neuroscience(Neuroscience 2006), Atlanta, USA, Oct. (2006).
Takeichi H., Koyama S., Matsumoto H., Morotomi T.,
and Cichocki A.: “Assessment of Speech Comprehension: Applications of M-Sequence Modulation
and Independent Component Analysis to Electroencephalography”, 10th Tamagawa-Riken Dynamic
Brain Forum (DBF2007), Hakuba, Mar. (2007).
(Domestic Conference)
竹市博臣, 小山幸子, 眞溪歩, Cichocki A.: “An independent component analysis of EEG response to spoken
sentence modulated by m-sequence”, 第 29 回日本神経科学大会（Neuroscience 2006）, 京都, 7 月 (2006).
竹市博臣, 小山幸子, 眞溪歩, Cichocki A.: “聴覚野におけるリアルタイム音声言語（談話）の処理の脳波を用いた検討”, 脳と心のメカニズム第 7 回夏のワーク
ショップ「感覚認知の計算理論とダイナミクス」, 札幌,
8 月 (2006).
竹市博臣, 小山幸子, 木村元洋, 松本秀彦, 井上康之, 北崎充晃, 諸冨隆: “視覚誘発電位を用いた三次元補完の検討”, 日本心理学会第 70 回大会, 福岡, 11 月 (2006).
松本秀彦, 諸冨隆, 竹市博臣, 豊巻敦人, 小山幸子: “連続
音中の短い無音部に対する中枢聴覚処理：ERP を用いた発達的変化の検討”, 日本心理学会第 70 回大会,
福岡, 11 月 (2006).
松本秀彦, 諸冨隆, 竹市博臣, 豊巻敦人, 小山幸子: “音の持続呈示中の無音部に対する中枢聴覚処理の発達的特徴”, 第 36 回日本臨床神経生理学会・学術大会, 横浜,
11–12 月 (2006).
竹市博臣, 小山幸子, 松本秀彦, 諸冨隆, Cichocki A.: “リアルタイム音声言語（談話）処理の脳波を用いた検討：
再現性の確認”, 脳と心のメカニズム第 7 回冬のワー
クショップ「Neuroeconomics」, 留寿都, 1 月 (2007).
竹市博臣, 竹内文也, 寺尾敦, 豊澤悠子, 小山幸子: “m 系列変調（劣化）音声に対する fMRI 応答”, 脳機能解析
学分野第 1 回シンポジウム, (北海道大学), 札幌, 1 月(2007).
竹市博臣: “脳情報工学と情報脳科学”, 電子情報通信学会 2007 年総合大会, 名古屋, 3 月 (2007).

Radiation Lab.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Adcox K., Bazilevsky A. V., Bunce G. M., DeshpandeA., En’yo H., Fox B., Goto Y., Grosse Perdekamp
M., Hayashi N., Ichihara T., Imai K., Ishihara
M., Jacak B. V., Kobayashi H., Kurita K., Li Z.,
Mao Y., Murata J., Saito N., Sakuma T., Sato H.,
Shibata T., Sugioka M., Taketani A., Tojo J., Torii
H., Watanabe Y., Yokkaichi S., and PHENIX C.:“PHENIX detector overview”, Nuclear Instruments
and Methods in Physics Research A 499, 469–479(2003). ＊Aronson S. H., Ichihara T., Saito N., and PHENIX
Collaboration .: “PHENIX Magnet System”, Nuclear Instruments and Methods in Physics Research
A 499, 480–488 (2003). ＊Aphecetche L., Bazilevsky A. V., Goto Y., Grosse
Perdekamp M., and PHENIX Collaboration.:“PHENIX Calorimeter”, Nuclear Instruments andMethods in Physics Research A 499, 521–536(2003). ＊Akikawa H., En’yo H., Hayashi N., Ichihara T.,
Ishihara M., Kobayashi H., Kurita K., Li Z., Mao Y.,
Murata J., Saito N., Sato H., Shibata T., Sugioka
M., Taketani A., Watanabe Y., and PHENIX
Collaboration.: “PHENIX muon arms”, Nuclear Instruments and Methods in Physics Research A 499,
537–548 (2003). ＊Adler S. S., Sato H., Taketani A., and PHENIX C.:“PHENIX on-line systems”, Nuclear Instruments
and Methods in Physics Research A 499, 560–592(2003). ＊Adler S. S., Ichihara T., Jacak B. V., WatanabeY., Yokkaichi S., and PHENIX C.: “PHENIX online and oﬀ-line computing”, Nuclear Instruments
and Methods in Physics Research A 499, 593–602(2003). ＊- 358 -

Murata J., Horaguchi T., Kamihara N., Kobayashi H.,
Shibata T., and PHENIX C.: “Optical alignment
system for the PHENIX muon tracking chambers”,
Nuclear Instruments and Methods in Physics Research A 500, 309–317 (2003). ＊Heuser J. M. and PHENIX Collaboration .: “Vertex
detector upgrade plans for the PHENIX experiment
at RHIC”, Nuclear Instruments and Methods inPhysics Research A 511, 210–214 (2003). ＊Kimura K., Izumikawa T., Koyama R., Ohnishi T.,
Ohtsubo T., Ozawa A., Shinozaki W., SuzukiT., Takahashi M., Tanihata I., Yamaguchi T.,
and Yamaguchi Y.: “High-rate particle identiﬁcation of high-energy heavy ions using a tilted electrode gas ionization chamber”, Nuclear Instruments
and Methods in Physics Research A 538, 608–614(2005). ＊Li Z., Enyo H., Eremin V., Goto Y., Li C. J., TaketaniA., and Tojo J.: “Electron beam and laser testing on
the novel stripixel detectors”, Nuclear Instruments
and Methods in Physics Research A 541, No. 1/2,
pp. 21–28 (2005). ＊Suzuki T., Ishiguro K., Mori Y., and Sekido T.: “TheDual Meissner Eﬀect and Magnetic Displacement
Current”, Phys. Rev. Lett. 94, 132001-1–132001-4(2005). ＊Ishii N., Doi T., Iida H., Oka M., Okiharu F.,
Suganuma H., and Tsumura K.: “Anisotropic lattice QCD studies of penta-quarks and tetra-quarks”,
AIP Conf. Proc. 842, 492–494 (2006). ＊Kondrashev S., Kanesue T., Okamura M., andSakakibara K.: “Features of ion generation using
Nd-glass laser”, J. Appl. Phys. 100, No. 1, pp.
103301-1–103301-8 (2006). ＊Takeuchi S., Aoi N., Baba H., Fukui T., Hashimoto Y.,
Ieki K., Imai N., Iwasaki H., Kanno S., Kondo Y.,
Kubo T., Kurita K., Minemura T., Motobayashi T.,
Nakabayashi T., Nakamura T., Okumura T., OnishiT., Ota S., Sakurai H., Shimoura S., Sugo R., SuzukiD., Suzuki H., Suzuki M., Takeshita E., Tamaki M.,
Tanaka K., Togano Y., and Yamada K.: “Proton
inelastic scattering on 32 Mg”, J. Phys.: Con. Ser.
49, 153–154 (2006). ＊Ariyoshi S., Otani C., Dobroiu A., Matsuo H., Sato H.,
Taino T., Kawase K., and Shimizu H.: “Superconducting Detector Array for Terahertz Imaging Applications”, Jpn. J. Appl. Phys. Pt.2 45, No. 37, pp.
L1004–L1006 (2006). ＊Oda S., Hamagaki H., Ozawa K., Inuzuka M.,
Sakaguchi T., Isobe T., Gunji T., Morino Y., Saito
S., Yamaguchi Y., Sawada S., and Yokkaichi S.: “Development of a time projection chamber using gas
electron multipliers (GEM-TPC)”, Nuclear Instruments and Methods in Physics Research A 566, 312–
320 (2006). ＊Michimasa S., Shimoura S., Iwasaki H., Tamaki M.,
Ota S., Aoi N., Baba H., Iwasa N., Kanno S.,

Kubono S., Kurita K., Uesaka M., Minemura T.,
Motobayashi T., Notani M., Ong H., Saito A.,
Sakurai H., Takeshita E., Takeuchi S., Yanagisawa
Y., and Yoshida A.: “Proton single-particle statesin the neutron-rich 23 F nucleus”, Phys. Lett. B 638,
146–152 (2006). ＊Tabaru T., Enyo H., Muto R., Naruki M., Yokkaichi
S., Chiba J., Sekimoto M., Tanaka K., Sasaki O.,
Ieiri M., Funahashi H., Kitaguchi M., Kanda H.,
Mihara S., Miyashita T., Murakami T., Ozawa K.,
Hamagaki H., Sakuma F., Yamada S., Togawa M.,
Fukao Y., Ishino M., Miwa K., Nakura T., andYoshimura Y.: “Nuclear mass number dependence
of inclusive production of omega and phi mesons in
12-GeV p + A collisions”, Phys. Rev. C 74, 0252011–025201-11 (2006). ＊De Vita R., CLAS Collaboration ., and Nakagawa I.:“Search for the Θ+ pentaquark in the reactions γp →00
K K + n and γp → K K 0 p”, Phys. Rev. D 74, No.
3, pp. 032001-1–032001-16 (2006). ＊Iida H., Doi T., Ishii N., Suganuma H., and Tsumura
K.: “Charmonium properties in deconﬁnement
phase in anisotropic lattice QCD”, Phys. Rev. D 74,
074502-1–074502-12 (2006). ＊Naruki M., Fukao Y., Funahashi H., Ishino M., Kanda
H., Kitaguchi M., Mihara S., Miwa K., MiyashitaT., Murakami T., Nakura T., Sakuma F., Togawa
M., Yamada S., Yoshimura Y., Enyo H., Muto R.,
Tabaru T., Yokkaichi S., Chiba J., Ieiri M., SasakiO., Sekimoto M., Tanaka K. H., Hamagaki H.,
and Ozawa K.: “Experimental signature of medium
modiﬁcations for ρ and ω mesons in 12 GeV p + A
reactions”, Phys. Rev. Lett. 96, No. 9, pp. 0923011–092301-4 (2006). ＊McKinnon B., CLAS Collaboration ., and Nakagawa
I.: “Search for Θ+ pentaquark in the reaction γp →pK − K + n”, Phys. Rev. Lett. 96, No. 21, pp. 2120011–212001-6 (2006). ＊Bai M., Roser T., Ahrens L., Alekseev I. G., Alessi J.,
Beebe-Wang J., Blaskiewicz M., Bravar A., Brennan
J. M., Bruno D., Bunce G. M., Courant E., Drees A.,
Fischer W., Gardner C., Gill R., Glenn J., HaeberliW., Huang H., Jinnouchi O., Kewisch J., Luccio A.,
Luo Y., Nakagawa I., Okada H., Pilat F., MacKay
W. W., Makdisi Y., Montag C., Ptitsyn V., Satogata
T., Stephenson E., Svirida D., Tepikian S., Trbojevic
D., Tsoupas N., Wise T., Zelenski A., Zeno K.,
and Zhang S. Y.: “Polarized Proton Collisions at
205 GeV at RHIC”, Phys. Rev. Lett. 96, 174801-1–
174801-4 (2006). ＊Mishima K., Sato H., Yamada S., Hirota K., Suzuki J.,
Oku T., Morishima T., Shimizu H., and Shinohara
T.: “Development of measurement system of neutron β decay”, Physica B 385/386, No. 2, pp. 1219–
1221 (2006). ＊Taketani K., Funahasi H., Seki Y., Hino M., Kitaguchi
M., Otake Y., and Shimizu H. M.: “Moire fringes of- 359 -

cold neutron with large divergence angle”, Physica
B 385/386, 1222–1224 (2006). ＊Kawamura S., Kaneko J. H., Fujimoto H., Otake Y.,
Fujita F., Homma A., Sawamura T., Mikula P., andFurusaka M.: “Possibility of using a PMN-PT single crystal as neutron optical device”, Physica B
385/386, 1277–1279 (2006). ＊Doi T., Blum T. C., Hayakawa M., Izubushi T., andYamada N.: “The Isospin breaking eﬀect on baryons
with N(f) = 2 domain wall fermions”, Proceedingsof Science LAT2006, 174-1–174-7 (2006). ＊Okamura M., Kashiwagi H., Sakakibara K., Takano
J., Hattori T., Hayashizaki N., Jameson R., andYamamoto K.: “High current carbon beam production with direct plasma injection scheme”, Rev. Sci.
Instrum. 77, 03B303-1–03B303-3 (2006). ＊Sakakibara K., Okamura M., Kondrashev S., HattoriT., Kashiwagi H., and Kanesue T.: “Analysis of
Laser-Produced Heavy Ions for Direct Plasma Injection Scheme”, Rev. Sci. Instrum. 77, 03B304-1–
03B304-3 (2006). ＊Kashiwagi H., Fukuda M., Okamura M., Jameson R.,
Hattori T., Hayashizaki N., Sakakibara K., TakanoJ., Yamamoto K., Iwata Y., and Fujimoto T.: “Acceleration of high current fully stripped carbon ion
beam by direct injection scheme”, Rev. Sci. Instrum.
77, 03B305-1–03B305-4 (2006). ＊Muto R., Chiba J., Enyo H., Fukao Y., Funahashi
H., Hamagaki H., Ieiri M., Ishino M., Kanda H.,
kitaguchi m., Mihara S., Miwa K., Miyashita T.,
Murakami T., Nakura T., Naruki M., Ozawa K.,
Sakuma F., Sasaki O., Sekimoto M., Tabaru T.,
Tanaka K., Togawa M., Yamada S., Yokkaichi S.,
and Yoshimura Y.: “Evidence for in-medium modiﬁcation of the φ meson at normal nuclear density”,
Phys. Rev. Lett. 98, No. 4, pp. 042501-1–042501-4(2007). ＊四日市悟, Chiba J., 延与秀人, 深尾祥紀, 舟橋春彦,
浜垣秀樹, Ieiri M., Ishino M., Kanda H., 北口雅暁,
Mihara S., Miyashita T., 三輪浩司, 村上哲也, 武藤亮太郎, Nakura T., 成木恵, 小沢恭一郎, 佐久間史典,
Sasaki O., 関本美知子, 田原司睦, Tanaka K., 外川学,
Yamada S., Yoshimura Y.: “Experimental Study of
in-medium meson modiﬁcation at the KEK 12 GeVPS”, 素粒子論研究 114, No. 2, pp. B7–B12 (2006).
[Book・Proc.](Original Papers) ＊ Subject to Peer Review
Taketani K., Funahasi H., Seki Y., Hino M., KitaguchiM., Maruyama R., Otake Y., and Shimiuzu H. M.:“Development of Mach-Zehnder Interferometer and“Coherent Beam Steering” Technique for Cold Neutrons”, Foundations of Quantum Mechanics in theLight of New Technology (ISQM-Tokyo’05) Proceedings of 8th International Symposium, Hatoyama,
2005–8, World Scientiﬁc, Hatoyama, pp. 282–285(2006). ＊Oral Presentations(International Conference etc.)
Ishii N., Doi T., Iida H., Oka M., Okiharu F.,
and Suganuma H.: “Penta-quark anti-decuplet inanisotropic lattice QCD”, LATTICE 2004: 22ndInternational Symposium on Lattice Field Theory,(Fermi National Accelerator Laboratory), Batavia,
USA, June (2004).
Doi T., Ishii N., Oka M., and Suganuma H.: “The lattice QCD simulation of the quark-gluon mixed condensate gq̄σµν Gµν q at ﬁnite temperature and thephase transition of QCD”, LATTICE 2004: 22ndInternational Symposium on Lattice Field Theory,
Batavia, USA, June (2004).
Ishii N., Doi T., Iida H., Oka M., Okiharu F., andSuganuma H.: “Anisotropic lattice QCD studies ofpenta-quark anti-decuplet”, International Workshop
on PENTAQUARK04, (RCNP and JASRI), Harima
Science Garden City, July (2004).
Doi T., Ishii N., Oka M., and Suganuma H.:“Thermal eﬀects on quark-gluon mixed condensate gq̄σµν Gµν q from lattice QCD”, 2004 Gordon Research Conference on Photonuclear Reactions, Tilton, USA, Aug. (2004).
Yamada K., Motobayashi T., Aoi N., Baba H., Demichi
K., Elekes Z., Gibelin J. D., Gomi T., Hasegawa H.,
Imai N., Iwasaki H., Kanno S., Kubo T., Kurita K.,
Matsuyama Y., Michimasa S., Minemura T., Notani
M., Onishi T., Ong H., Ota S., Ozawa A., Saito A.,
Sakurai H., Shimoura S., Takeshita E., Takeuchi S.,
Tamaki M., Togano Y., Yanagisawa Y., Yoneda K.,
and Tanihata I.: “The ﬁrst measurement of reduced
transition probabilities for ﬁrst 2+ excited state in46
Cr, 50 Fe, and 54 Ni”, 4th International Conference
on Exotic Nuclei and Atomic Masses (ENAM 04),
(Oak Ridge National Laboratory), Pine Mountain,
USA, Sept. (2004).
Ishii N., Doi T., Iida H., Oka M., Okiharu F., andSuganuma H.: “Penta-quark in anisotropic lattice
QCD”, 10th International Conference on the Structure of Baryons (Baryons 2004), Palaiseau, France,
Oct. (2004).
Togawa M. and PHENIX C.: “Study of the gluon polarization in the proton with a silicon vertex upgrade at RHIC/PHENIX”, 16th International Spin
Physics Symposium (SPIN 2004), Trieste, Italy, Oct.
(2004).
Watanabe Y.: “DAQ system for RI beam facilities:
present and future”, 5th Italy-Japan Symposium
on Recent Achievements and Perspectives in Nuclear Physics, (Istituto Nazionale di Fisica Nucleare), Naples, Italy, Nov. (2004).
Okiharu F., Doi T., Ichie H., Iida H., Ishii N., Oka M.,
Suganuma H., and Takahashi T. T.: “Tetraquarkand pentaquark systems in lattice QCD”, Quark Nuclear Physics 2005: Nuclear and Hadronic Systems
and Quark Degrees of Freedom, Pyoungchang, Ko-- 360 -

rea, Feb. (2005).
Iida H., Doi T., Ishii N., and Suganuma H.: “J/Ψ athigh temperatures in anisotropic lattice QCD”, 23rd
International Symposium on Lattice Field Theory(Lattice 2005), Dublin, Ireland, July (2005).
Doi T., Ishii N., Nemoto Y., Oka M., and Suganuma
H.: “Anisotropic lattice QCD study of pentaquark
baryons in spin 3/2 channel”, 23rd International
Symposium on Lattice Field Theory (Lattice 2005),
Dublin, Ireland, July (2005).
Ishii N., Doi T., Nemoto Y., Oka M., and Suganuma
H.: “Anisotropic lattice QCD studies of spin 3/2
penta-quark”, 2nd Joint Meeting of the Nuclear
Physics Divisions of the APS and JPS (Hawaii 2005),
Maui, USA, Sept. (2005).
Togano Y., Gomi T., Motobayashi T., Ando Y., Aoi
N., Baba H., Demichi K., Elekes Z., Fukuda N.,
Fulop Z., Hasegawa H., Higurashi Y., Ieki K., ImaiN., Ishihara M., Ishikawa K., Iwasa N., Iwasaki H.,
Kanno S., Kondo Y., Kubo T., Kubono S., Kurita
K., Matsuyama Y., Michimasa S., Minemura T.,
Miura M., Murakami H., Nakamura T., Notani M.,
Ota S., Saito A., Sakurai H., Serata M., ShimouraS., Sugimoto T., Takeshita E., Takeuchi S., Ue K.,
Yamada K., Yanagisawa Y., Yoneda K., Yoshida A.,
Futakami U., and Kunibu M.: “Coulomb dissociation of 27 P for Study of 26 Si(p,γ)27 P reaction”, 2ndJoint Meeting of the Nuclear Physics Divisions of
the APS and JPS (Hawaii 2005), Maui, USA, Sept.
(2005).
Akiba Y.: “Hadronic Probes of dense matter at RHIC:
From light to heavy ﬂavors”, 2nd Joint Meeting of
the Nuclear Physics Divisions of the APS and JPS(Hawaii 2005), Maui, USA, Sept. (2005).
Doi T., Blum T. C., Hayakawa M., Izubushi T., andYamada N.: “Isospin breaking of baryon masses
from domain-wall lattice QCD”, 2nd Joint Meetingof the Nuclear Physics Divisions of the APS and JPS(Hawaii 2005), Maui, USA, Sept. (2005).
Michimasa S., Aoi N., Iwasa N., Iwasaki H., Kanno S.,
Kubono S., Kurita K., Minemura T., Motobayashi
T., Notani M., Ong H., Ota S., Saito A., ShimouraS., Takeshita E., Tamaki M., Uesaka M., Yanagisawa
Y., Yoshida A., Sakurai H., Takeuchi S., and Baba
H.: “Measurement of proton transfer reaction for
single-particle states in 23 F”, 2nd Joint Meeting of
the Nuclear Physics Divisions of the APS and JPS(Hawaii 2005), Maui, USA, Sept. (2005).
Okada H.: “Measurement of the transverse-spin asymmetries in pp elastic scattering in the peak CNI region at RHIC”, 2nd Joint Meeting of the Nuclear
Physics Divisions of the APS and JPS (Hawaii 2005),
Maui, USA, Sept. (2005).
Yamada K., Iwasa N., Bishop S., Elekes Z., Gibelin
J. D., Hosoi M., Ieki K., Ishikawa K., Iwasaki
H., Kawai S., Kondo Y., Kubono S., Kurita K.,
Kurokawa M., Matsui N., Minemura T., Morikawa

H., Nakamura T., Niikura M., Notani M., Ota S.,
Saito A., Sakurai H., Shimoura S., Sugawara K.,
Sugimoto T., Suzuki H., Suzuki T., Takeshita E.,
Takeuchi S., Tanihata I., Teranishi T., Togano Y.,
Yamaguchi K., Yanagisawa Y., and Motobayashi T.:“New Coulomb Excitation Measurement of 18 Ne”,
2nd Joint Meeting of the Nuclear Physics Divisionsof the APS and JPS (Hawaii 2005), Maui, USA,
Sept. (2005).
Ishii N., Doi T., Iida H., Nemoto Y., Oka M., Okiharu
F., Suganuma H., and Tsumura K.: “Anisotropic
lattice QCD studies of penta-quarks and tetraquarks”, Particles and Nuclei International Conference (PANIC05), Santa Fe, USA, Oct. (2005).
Takeuchi S., Aoi N., Baba H., Fukui T., HashimotoY., Ieki K., Imai N., Iwasaki H., Kanno S., Kondo
Y., Kurita K., Minemura T., Motobayashi T.,
Nakabayashi T., Nakamura T., Okumura T., OnishiT., Ota S., Sakurai H., Shimoura S., Sugo R., SuzukiD., Suzuki H., Suzuki M., Takeshita E., Tamaki
M., Tanaka K., Togano Y., and Yamada K.: “Proton inelastic scattering of 32 Mg”, International Symposium on Structure of Exotic Nuclei and Nuclear
Forces (SENUF06), (University of Tokyo), Tokyo,
Mar. (2006).
Kondrashev S., Kashiwagi H., Kanesue T., Jameson
R., Okamura M., Sakakibara K., and Tamura J.:“Acceleration of Intense Beams of Highly-Charged
Ions using Direct Plasma Injection Scheme”, 39th
ICFA Advanced Beam Dynamics Workshop on HighIntensity High Brightness Hadron Beams (ICFA
HB2006), (KEK), Tsukuba, May–June (2006).
Huang H., Okamura M., and Takano J.: “Acceleration of Polarized protons in the AGS with Two Helical Partial Snakes”, 10th biennial European Particle
Accelerator Conference (EPAC’06), (EPAC), Edinburgh, UK, June (2006).
Kanesue T., Kondrashev S., Okamura M., andSakakibara K.: “Ag Acceleration Using Direct
Plasma Injection Method”, 10th biennial European Particle Accelerator Conference (EPAC’06),(EPAC), Edinburgh, UK, June (2006).
Kondrashev S., Kanesue T., Okamura M., andSakakibara K.: “Generation of Highly Charged Ions
Using ND-glass Laser”, 10th biennial European Particle Accelerator Conference (EPAC’06), (EPAC),
Edinburgh, UK, June (2006).
Yokkaichi S.: “Medium modiﬁcation of vector mesons
in 12 GeV p+A reactions at KEK-PS”, 9th International Workshop on Meson Production, Properties
and Interaction (MESON2006), Cracow, Poland,
June (2006).
Goto Y. and Forte S.: “Spin physics working groupsummary”, 14th International Workshop on Deep
Inelastic Scattering (DIS2006), (KEK (High Energy
Accelerator Research Organization)), Tsukuba, July
(2006).

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Goto Y.: “Spin physics of the J-PARC dimuon experiment”, Advanced Studies Institute: Symmetries
and Spin (SPIN-Praha-2006), (Charles University
in Prague, Faculty of Mathematics and Physics),
Prague, Czech, July (2006).
Goto Y.: “Spin physics results at PHENIX”, Advanced
Studies Institute: Symmetries and Spin (SPINPraha-2006), (Charles University in Prague, Facultyof Mathematics and Physics), Prague, Czech, July
(2006).
Ariyoshi S., Otani C., Dobroiu A., Matsuo H., Sato H.,
Taino T., Kawase K., and Shimizu H.: “Terahertz
Imaging with an STJ-based Linear Array Detector(Invited Oral)”, Applied Superconductivity Conference 2006 (ASC 2006), Seattle, USA, Aug.–Sept.
(2006).
Otani C., Ariyoshi S., Taino T., Dobroiu A., ShibuyaT., Sato H., Shimizu H., and Kawase K.: “Development of Terahertz Imaging Detectors using Superconducting Tunnel Junctions”, International Conference on Mesoscopic Superconductivity and Magnetism (MesoSuperMag 2006), (Argonne National
Laboratory), Chicago, USA, Aug.–Sept. (2006).
Michimasa S., Shimoura S., Iwasaki H., Tamaki M.,
Ota S., Aoi N., Baba H., Iwasa N., Kanno S.,
Kubono S., Kurita K., Minemura T., Motobayashi
T., Notani M., Ong H., Saito A., Sakurai H.,
Takeshita E., Takeuchi S., Uesaka M., Yanagisawa
Y., and Yoshida A.: “Proton shell structure inneutron-rich 23 F”, International Conference on Nucleus Nucleus Collisions (NN2006), Rio de Janeiro,
Brazil, Aug.–Sept. (2006).
Ariyoshi S., Otani C., Dobroiu A., Matsuo H., Sato
H., Taino T., Kawase K., and Shimizu H.: “THz
Imaging with a Linear Array Detector based on Superconducting Tunnel Junctions”, 2006 Joint 31st
International Conference on Infrared and Millimeter
Waves and 14th International Conference on Terahertz Electronics (IRMMW-THz2006), (Shanghai
Institute of Technical Physics (SITP)), Shanghai,
China, Sept. (2006).
Seki Y., Funahasi H., Taketani K., Kitaguchi M.,
Hino M., Otake Y., and Shimiuzu H. M.: “Development of Neutron Interferometer with Wide-Gapped
BSEs for Precision Measurements”, 17th International Spin Physics Symposium (SPIN2006), (Department of Physics, Kyoto University), Kyoto, Oct.
(2006).
Otani C., Ariyoshi S., Taino T., Myoren H., Sato
H., Shimizu H., Takada S., and Kawase K.: “Terahertz Detectors using Superconducting Tunnel Junctions (Invited)”, 19th International Symposium on
Superconductivity (ISS 2006), (International Superconductivity Technology Center (ISTEC)), Nagoya,
Oct.–Nov. (2006).
Taino T., Ishii H., Yoshimura S., Otani C., AriyoshiS., Myoren H., Kawase K., Shibuya T., Sato

H., Shimizu H., and Takada S.: “Terahertz
electromagnetic-waves detector using Nb-based superconducting tunnel junction on LiNb03 substrateabsorber”, 19th International Symposium on Superconductivity (ISS 2006), (ISTEC (International Superconductivity Technology Center)), Nagoya, Oct.–
Nov. (2006).
Otani C., Ariyoshi S., Taino T., Sato H., Shimizu H.,
and Kawase K.: “Radiation Detectors using Superconducting Tunnel Junctions (invited lecture)”, 14th
International Symposium on Laser Spectroscopy(SOLS 2006), (KAERI), Daejeon, Korea, Nov.
(2006).
Enyo H.: “Experimental signatures for vector meson
modiﬁcation in nuclear medium”, Yukawa International Seminar (YKIS) 2006 New Frontiers in QCD:
Exotic Hadrons and Hadronic Matter, (Yukawa Institute for Theoretical Physics, Kyoto University),
Kyoto, Nov.–Dec. (2006).
Otani C., Ariyoshi S., Taino T., Dobroiu A., Sato H.,
Shimizu H., and Kawase K.: “Development of Terahertz Detectors using Superconducting Tunnel Junctions (invited)”, 2nd CREST Nano-Virtual-Labs
Joint Workshop on Superconductivity (NVLS2006),
Kyoto, Dec. (2006).
Sato H. and Mishima K.: “Low energy proton detector using STJ with large area”, 2nd CREST NanoVirtual-Labs Joint Workshop on Superconductivity (NVLS2006), (Nagoya University), Kyoto, Dec.
(2006).
Ariyoshi S., Otani C., Dobroiu A., Matsuo H., Taino
T., Sato H., and Shimizu H.: “STJ-based direct detector array for terahertz imaging applications”, 7thWorkshop on Submillimeter-Wave Receiver Technologies in Eastern Asia/Workshop on the Development of Low-Noise Receiver Technology at Millimeter Waves and Terahertz Frequencies, (Nobeyama
Radio Observatory), Sakai, Jan. (2007).
(Domestic Conference)
竹下英里, 青井考, 大田晋輔, 武内聡, 鈴木宏, 馬場秀忠,
Bishop S., 福井利晃, 井手口栄治, 家城和夫, 今井伸明,
岩崎弘典, 菅野祥子, 近藤洋介, 久保敏幸, 栗田和好,
日下健祐, 峯村俊行, 本林透, 中林彩, 中村隆司, 中尾
太郎, 新倉潤, 奥村俊文, 王惠仁, 大西健夫, 櫻井博儀,
下浦享, 須合亮平, 鈴木大介, 鈴木賢, 玉城充, 田中
鐘信, 栂野泰宏, 山田一成: “中性子過剰核 Cr 同位体の陽子非弾性散乱”, 日本物理学会第 61 回年次大会,
松山, 3 月 (2006).
延與秀人: “ハドロン物理の新展開 – RHIC から J-Parc
へ –（招待講演）”, 日本物理学会第 61 回年次大会, 松山, 3 月 (2006).
道正新一郎, 下浦享, 岩崎弘典, 玉城充, 大田晋輔, 青井
考, 馬場秀忠, 岩佐直仁, 菅野祥子, 久保野茂, 栗田
和好, 峯村俊行, 本林透, 野谷将広, 王惠仁, 齋藤明登,
櫻井博儀, 竹下英里, 武内聡, 上坂明子, 柳澤善行, 吉田敦: “Single-particle states in 23 F by a proton transfer reaction”, 日本物理学会第 61 回年次大会, (日本物

- 362 -

理学会), 松山, 3 月 (2006).
三島賢二, 佐藤広海, 大野雅史, 森嶋隆裕, 山田悟, 奥隆之, 鈴木淳市, 清水裕彦: “中性子ビームラインにおける原研 3 号炉での中性子ベータ崩壊実験 (NBD)
について：超伝導検出器 (STJ) の運用”, 日本物理学会第 61 回年次大会, 松山, 3 月 (2006).
武内聡, 青井考, 馬場秀忠, 福井利晃, 橋本佳子, 家城
和夫, 今井伸明, 岩崎弘典, 菅野祥子, 近藤洋介, 栗田
和好, 峯村俊行, 本林透, 中林彩, 中村隆司, 奥村俊文,
大西健夫, 大田晋輔, 櫻井博儀, 下浦享, 須合亮平, 鈴木
大介, 鈴木宏, 鈴木賢, 竹下英里, 玉城充, 田中鐘信,
栂野泰宏, 山田一成: “32 Mg と 34 Si の γ 線核分光”,
RIBF ミニワークショップ「Island of Inversion に関する実験・理論の現状と今後の展望–7 < Z < 20 領域
中性子過剰核の低励起状態に関する検討会–」, 和光, 5
月 (2006).
大谷知行, 有吉誠一郎, 佐藤広海, 川瀬晃道, 田井野徹,
清水裕彦: “超伝導トンネル (STJ) 素子によるテラヘ
ルツ波アレイ検出器の開発とイメージング（招待講演）”, 応用物理学会超伝導分科会第 33 回研究会「高感度分析・分光技術のための超伝導検出器」, (超伝導工学研究所), 東京, 6 月 (2006).
石井宏和, 吉村正太, 田井野徹, 明連広昭, 大谷知行, 渋谷
孝幸, 有吉誠一郎, 佐藤広海, 延與秀人, 川瀬晃道, 高田進: “THz 波検出のための基板吸収型 STJ 検出器の高感度化”, 第 67 回応用物理学会学術講演会, 滋賀県草津, 8–9 月 (2006).
三島賢二, 佐藤広海, 山田悟, 森嶋隆裕, 奥隆之, 広田
克也, 鈴木淳市, 清水裕彦: “超伝導検出器 (STJ) を用いた中性子 β 崩壊の測定”, 日本物理学会 2006 年
秋季大会, 奈良, 9 月 (2006).
関義親, 舟橋春彦, 竹谷薫, 北口雅暁, 日野正裕, 大竹淑恵, 清水 (M) 裕彦: 日本中性子科学会第 6 回年会,
水戸, 12 月 (2006).
三島賢二, 佐藤広海, 山田悟, 森嶋隆裕, 広田克也, 鈴木
淳市, 奥隆之, 篠原武尚, 清水裕彦: “超伝導トンネル
接合素子を用いた中性子 β 崩壊測定実験”, 日本中性子科学会第 6 回年会, 水戸, 12 月 (2006).
有吉誠一郎, 大谷知行, Dobroiu A., 松尾宏, 田井野徹,
佐藤広海, 清水裕彦: “スペース天文応用を目指したサ
ブミリ波帯 STJ 検出器アレイの開発”, 第 7 回宇宙科
学シンポジウム, (宇宙航空研究開発機構宇宙科学研究本部), 相模原, 12 月 (2006).
有吉誠一郎, 大谷知行, Dobroiu A., 松尾宏, 佐藤広海,
田井野徹, 川瀬晃道, 清水裕彦: “超伝導検出器アレイを用いたテラヘルツイメージング”, 電子情報通信学
会電子デバイス研究会 2006 年度月間研究会（12 月）,
東京, 12 月 (2006).
成木恵: “J-PARC E19 High-resolusion Search for Θ+
Pentaquark in π − p → K − X Reaction”, 文部科学省
科学研究費補助金特定領域研究「ストレンジネスで探るクォーク多体系」研究会 2006, (KEK), 熱海, 12 月
(2006).
成木恵: “Pentaquark Θ+ Search in Hadronic Reaction”, RCNP 研究会「LEPS/SPring-8 新ビームライン」, 大阪, 1 月 (2007).
池田一昭, 広田克也, 佐藤広海, 大森整, 清水裕彦, 古坂

道弘: “中性子ビーム用デバイスのための曲面スーパーミラーの開発”, 日本物理学会 2007 年春季大会, 鹿児島, 3 月 (2007).
三島賢二, 佐藤広海, 山田悟, 広田克也, 森嶋隆裕, 鈴木
淳市, 奥隆之, 篠原武尚, 清水裕彦: “超伝導トンネル
接合素子を用いた中性子ベータ崩壊からの低エネル
ギー陽子検出器の開発”, 日本物理学会 2007 年春季大会, 八王子, 3 月 (2007).

Advanced Meson Science Lab.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Miller J. P., Carey R. M., Logashenko V., Lynch K. R.,
Roberts B. L., Silenko A., Bennett G., Lazarus D.
M., Leipuner L. B., Marciano W., Meng W., MorseW. M., Prigl R., Semertzidis Y. K., Balakin V.,
Bazhan A., Dunikov A., Khazin B., Khriplovich I.
B., Sylvestrov G., Orlov Y., Jungmann K., Debevec
P. T., Hertzog D. W., Onderwater C. J., Ozben C. S.,
Stephenson E., Auzinsh M., Cushman P., McNabb
R., Shafer-Ray N., Yoshimura K., Aoki A., Kuno
Y., Sato A., Iwasaki M., and Farley F. J.: “A New
Experiment to Measure the Muon Electric Dipole
Moment”, AIP Conf. Proc. 698, 196–199 (2003).
Suzuki K., Fujita M., Geissel H., Gilg H., Gillitzer
A., Hayano R., Hirenzaki S., Itahashi K., Iwasaki
M., Kienle P., Matos M., Munzenberg G., OhtsuboT., Sato M., Shindo M., Suzuki T., Weick H.,
Winkler M., Yamazaki T., Sato M., and Yoneyama
T.: “Deeply bound poonic 1s in sn isotopes”, Nucl.
Phys. A 721, 831c–834c (2003). ＊Suzuki K., Fujita M., Geissel H., Gilg H., Gillitzer A.,
Hayano R., Hirenzaki S., Itahashi K., Iwasaki M.,
Kienle P., Matos M., Muenzenberg G., Otsubo T.,
Sato M., Shindo M., Suzuki T., Weick H., Winkler
M., Yamazaki T., and Yoneyama T.: “Observattion of Pionic 1s States in Sn Nuclei and Its Implications on Chiral Symmetry Restoration”, Prog.
Theor. Phys. Suppl., No. 149, pp. 32–41 (2003). ＊Itahashi K., Iwasaki M., and Suzuki T.: “Experimental Search for Kaonic Nuclear Bound States in the4
He (stopped K− ,n) Reaction”, Prog. Theor. Phys.
Suppl., No. 149, pp. 233–239 (2003).
Beer G. A., Bragadireanu A. M., Cargnelli M.,
Curceanu C., Egger J. -., Fuhrmann H., GierschM., Guaraldo C., Iliescu M., Ishiwatari T., ItahashiK., Iwasaki M., Kienle P., Lauss B., Lucherini V.,
Ludhova L., Marton J., Mulhauser F., Ponta T.,
Schaller L. A., Sirghi D. L., Sirghi F., and Zmeskal
J.: “Kaonic Hydrogen: Status of the DEAR Experiment”, Prog. Theor. Phys. Suppl., No. 149, pp. 240–
246 (2003).
Curceanu C., Beer G. A., Bragadireanu A. M.,
Cargnelli M., Egger J. -., Fuhrmann H., GuaraldoC., Iliescu M., Ishiwatari T., Itahashi K., Iwasaki- 363 -

M., Lauss B., Lucherini V., Ludhova L., Marton
J., Mulhauser F., Ponta T., Schaller L. A., Seki
R., Sirghi D., Sirghi F., Strasser P., and Zmeskal
J.: “Last results from the DEAR experiment at
DAΦNE”, AIP Conf. Proc. 717, 175–179 (2004).
Suzuki T., Itahashi K., Iwasaki M., Matsuda Y.,
Okada S., Outa H., Sato M., Strasser P., Tomono
D., and Yamazaki T.: “A search for deeply boundkaonic nuclear states”, Nucl. Phys. A 754, 375c–
382c (2005). ＊Jönsson P. E., Takayama H., Aruga-Katori H., and ItoA.: “Dynamical breakdown of the Ising spin-glassorder under a magnetic ﬁeld”, Phys. Rev. B 71,
180412-1–180412-4 (2005). ＊Jonsson P. E., Aruga-Katori H., Ito A., and Takayama
H.:“Field eﬀects in the Ising spin glass
Fe0.55 Mn0.45 TiO3 —Absence of spin-glass transition
in a magnetic ﬁeld”, Prog. Theor. Phys. Suppl., No.
157, pp. 38–41 (2005). ＊Tomono D.: “Presicion measurement of the positive
muon lifetime at the RIKEN-RAL muon facility”,
AIP Conf. Proc. 842, 906–908 (2006). ＊Tonishi J., Suzuki T., and Goto T.: “Anomalous Change of Hall Coeﬃcient in Overdoped
La2−x Srx Cu1−y Zny O4 around x = 0.2”, AIP Conf.
Proc. 850, 407–408 (2006). ＊Suzuki T., Ota T., Tonishi J., and Goto T.: “Increase of the sound velocity by magnetic ﬁelds inLa2−x Srx CuO4 around x = 0.220”, AIP Conf. Proc.
850, 409–410 (2006). ＊Inoue H., Tani S., Hosoya S., Suzuki T., Goto T.,
Tanaka H., Sasaki T., and Kobayashi N.: “2 D,
35/37
Cl, 63/65 Cu-NMR Study of the Quantum Spin
System NH4 CuCl3 ”, AIP Conf. Proc. 850, 1061–
1062 (2006). ＊Suzuki T., Saito T., Sasaki T., Osawa A., Goto T.,
Awaji S., Watanabe K., Kobayashi N., and Manaka
H.: “Magnetic ﬁeld eﬀect on the magnetic torqueand the magnetostriction in (CH3 )2 CHNH3 CuCl3 ”,
J. Phys.: Con. Ser. 51, 187–190 (2006). ＊Fujiwara T., Inoue H., Osawa A., Tsunoda R., Goto
T., Suzuki T., Shindo Y., Tanaka H., Sasaki T.,
Kobayashi N., Awaji S., and Watanabe K.: “CuNMR study on the disordered quantum spin magnet
with the Bose-glass ground state”, J. Phys.: Con.
Ser. 51, 199–202 (2006). ＊Tonishi J., Ueda M., Suzuki T., Osawa A., Goto T.,
Adachi T., Koike Y., Fujita M., and Yamada K.:“Local structure in single crystals of La-based highTc cuprates”, J. Phys.: Con. Ser. 51, 275–278 (2006).
＊
Suzuki T., Fujiwara T., Osawa A., Goto T., YamadaF., Tanaka H., and Watanabe I.: “Muon-SpinRelaxation study on single crystals Tl1−x Kx CuCl3
with x = 0.2”, J. Phys. Soc. Jpn. 75, No. 2, pp.
025001-1–025001-2 (2006). ＊Hachitani K., Amanuma H., Fukazawa H., Kohori Y.,

Koyama K., Kumagai K., Sekine C., and Shirotani
I.: “Appearance of successive phase transition in
SmRu4 P12 under high magnetic ﬁelds probed by 31 P
nuclear magnetic resonance”, J. Phys. Soc. Jpn. 75,
No. 12, pp. 124712-1–124712-6 (2006). ＊Hachitani K., Fukazawa H., Kohori Y., Watanabe I.,
Yoshimitsu Y., Kumagai K., Giri R., Sekine C.,
and Shirotani I.: “31 P-NMR and µSR studies ofﬁlled skutterudite compound SmFe4 P12 :evidence forheavy fermion behavior with ferromagnetic groundstate”, J. Phys. Soc. Jpn. 75, No. 12, pp. 124717-1–
124717-5 (2006). ＊Attwood D., Bell P., Bull S., McMahon T., Wilson
J., Fernow R., Gruber P., Jamdagni A., Long K.,
McKigney E., Savage P., Curtis-Rouse M., Edgecock
T. R., Ellis M., Lidbury J., Murray W., Norton
P., Peach K., Ishida K., Matsuda Y., Nagamine K.,
Nakamura S., Marshall G. M., Benveniste S., Cline
D., Fukui Y., Lee K., Pischalnikov Y., Holmes S.,
and Bogacz A.: “The scattering of muons in lowZ materials”, Nucl. Instrum. Methods Phys. Res. B
251, 41–55 (2006). ＊Matsuda Y., Bakule P., Iwasaki M., Matsuzaki T.,
Miyake Y., Ikedo Y., Strasser P., Simomura K.,
Makimura S., and Nagamine K.: “Generation of lowenergy muons with laser resonant ionization”, Nucl.
Phys. B (Proc. Suppl.) 155, 346–348 (2006). ＊Ishiwatari T., Beer G. A., Bragadireanu A. M.,
Cargnelli M., Curceanu P. C., Egger J. P., Fuhrmann
H., Guaraldo C., Iliescu M., Itahashi K., Iwasaki
M., Kienle P., Lauss B., Lucherini V., Ludhova L.,
Marton J., Mulhauser F., Ponta T., Schaller L. A.,
Sirghi D. L., Strasser P., and Zmeslal J.: “New analysis method for CCD X-ray data”, Nuclear Instruments and Methods in Physics Research A 556, 509–
515 (2006). ＊Hachitani K., Fukazawa H., Kohori Y., Watanabe I.,
Sekine C., and Shirotani I.: “Evidence for magnetic
ordering associated with metal-insulator transitionin SmRu4 P12 studied by muon spin relaxation”,
Phys. Rev. B 73, 052408-1–052408-4 (2006). ＊Saito T., Osawa A., Goto T., Suzuki T., and Watanabe
I.: “Muon spin rotation and relaxation studies
on the solid solution of the two spin-gap systems(CH3 )2 CHNH3 -CuCl3 and (CH3 )2 CHNH3 -CuBr3 ”,
Phys. Rev. B 74, 134423-1–134423-5 (2006). ＊Torikai E., Ito A., Watanabe I., and Nagamine K.:“µSR studies on the response of spin dynamics toapplying or removing magnetic ﬁeld — Typical Ising
spin glass Fe0.05 Mn0.05 TiO3 ”, Physica B 374/375,
95–98 (2006). ＊Bakule P., Matsuda Y., Iwasaki M., Miyake Y.,
Nagamine K., Ikedo Y., Simomura K., and Strasser
P.: “Pulsed source of ultra low-energy muons at
RIKEN-RAL”, Physica B 374/375, 456–459 (2006).
＊
Miyake Y., Nishiyama K., Kawamura N., Makimura- 364 -

S., Strasser P., Simomura K., Beveridge J. L.,
Kadono R., Fukuchi K., Sato N., Ueno K.,
Higemoto W., Ishida K., Matsuzaki T., Watanabe I.,
Matsuda Y., Iwasaki M., Nakamura S., Doornbos J.,
and Nagamine K.: “Status of J-PARC muon sciencefacility at the year of 2005”, Physica B 374/375,
484–487 (2006). ＊Jonsson P. E., Takayama H., Aruga-Katori H., and ItoA.: “Absence of phase transition in a magnetic ﬁeld
in the Fe0.55 Mn0.45 TiO3 Ising spin glass”, J. Magn.
Magn. Mater. 310, 1494–1499 (2007). ＊Oral Presentations(International Conference etc.)
Matsuda Y.: “Generation of ultra slow muon beam bylaser resonant ionization of muonium atoms”, 6thInternational Workshop on Neutrino Factories andSuperbeams (NuFact 04), Osaka, July–Aug. (2004).
Iwasaki M.: “Kaonic deeply bound states, the ﬁrst
experimental results”, International Conference on
Exotic Atoms and Related Topics (EXA 05), (theAustrian Academy of Sciences ), Vienna, Austria,
Feb. (2005).
Suzuki T., Ota T., Tonishi J., and Goto T.: “Increase of the sound velocity by magnetic ﬁelds inLa2−x Srx CuO4 around x = 0.220”, 24th International Conference on Low Temperature Physics(LT24), (Department of Physics, University of
Florida), Orlando, USA, Aug. (2005).
Iwasaki M.: “Strange trybaryon and present experimental program”, 2nd Joint Meeting of the Nuclear
Physics Divisions of the APS and JPS (Hawaii 2005),
Maui, USA, Sept. (2005).
Akaishi Y.: “Kaonic nuclei in reply to recent criticisms (Theory)”, International Workshop on Exotic
hadronic atoms, deeply bound kaonic nuclear states
and antihydrogen: present results, future challenges,(European Center for Theoretical Nuclear Physics
and Related Areas), Trento, Italy, June (2006).
Iwasaki M.: “Kaonic-Helium 3d-2p X-ray experiment”, International Workshop on Exotic hadronic
atoms, deeply bound kaonic nuclear states and antihydrogen: present results, future challenges, (European Cneter for Theoretical Studies in Nuclear
Physics and Related Areas), Trento, Italy, June
(2006).
Kikkawa A., Katsumata K., Honda Z., Watanabe I.,
Suzuki T., and Matsuzaki T.: “Evolution of thespin-gap in a spin-ladder material detected by muSR
technique”, 1st International Symposium of Quantum Beam Science Directorate of JAEA (ICM2006
Satellite Conference), (JAEA), Tokai, Aug. (2006).
Ishida K.: “Muon catalyzed fusion”, 8th International Workshop on Neutrino Factories nd Superbeams (NuFact 06), (University of California,
Irvine), Irvine, USA, Aug. (2006).
Suzuki T., Watanabe I., Osawa A., Goto T., Yamada

F., and Tanaka H.: “Muon-Spin-Relaxation study
on randomness introduced Tl1−x Kx CuCl3 with x= 0.44”, An ICM2006 Satellite Conference: 1stInternational Symposium of Quantum Beam Science Directorate of JAEA, Advances in Neutron,
Synchrotron Radiation, µSR and NMR Researches(QuBS2006), (Quantum Beam Science Directorateof JAEA), Tokai, Aug. (2006).
Jonsson P. E., Takayama H., Aruga-Katori H., and ItoA.: “Absence of phase transition in a magnetic ﬁeld
in the Fe0.55 Mn0.45 TiO3 Ising spin glass”, International Conference on Magnetism (ICM 2006), Kyoto,
Aug. (2006).
Suzuki T., Saito T., Osawa A., Goto T., Sasaki T.,
Awaji S., Watanabe K., Kobayashi N., and Manaka
H.: “Magnetic ﬁeld eﬀect on the magnetic torqueand the magnetostriction in (CH3 )2 CHNH3 CuCl3 ”,
Yamada Conference LX on Research in High Magnetic Fields (RHMF2006), (High Field Laboratory
for Superconducting Materials Institute for Materials Research Tohoku University), Sendai, Aug.
(2006).
Matsuda Y.: “Progress of laser ionization methodfor LEM”, 1st Swiss Japan Workshop on the applications and on new developments in muon spectroscopy on novel materials, (High Energy Accelerator Research Organization), Tsukuba, Sept. (2006).
Bakule P.: “Laser ionization of muonium - pulsed ultra
low energy muon source for material studies”, International Conference on Laser Probing 2006 (LAP
2006), (Vienna University of Technology), Vienna,
Austria, Sept. (2006).
Akaishi Y.: “Few-body antikaon nuclear bound states- theoretical view”, 9th International Conference onHypernuclear and Strange Particle Physics, Mainz,
Germany, Oct. (2006).
Ishida K.: “RIKEN-RAL, now and in the future”,
Workshop on future developments of European
muon sources, (NMI3), Abingdon, UK, Nov. (2006).
Koike T. and Harada T.: “DWIA calculation of3
He (in-ﬂight K− ,n) reaction”, Yukawa International
Seminar (YKIS) 2006 New Frontiers in QCD: Exotic
Hadrons and Hadronic Matter, (Yukawa Institute for
Theoretical Physics), Kyoto, Nov.–Dec. (2006).
Iwasaki M.: “Search for kaonic nuclear state bystopped K− on helium target at kek”, Yukawa International Seminar (YKIS) 2006 New Frontiers
in QCD: Exotic Hadrons and Hadronic Matter,(Yukawa Institute for Theoretical Physics), Kyoto,
Nov.–Dec. (2006).
(Domestic Conference)
蜂谷健一: “充填スクッテルダイト化合物 SmRu4 P12の µSR”, 日本物理学会 2005 年秋季大会, 京都, 9 月(2005).
川股隆行, 菅原直樹, Haidar S. M., 高橋伸雄, 宮島
祐一, 野地尚, 小池洋二, 工藤一貴, 小林典男, 藤井裕, 菊池彦光, 千葉明朗, Petrakovskii G., Popov- 365 -

M., Bezmaternikh L.: “La8 Cu7 O19 ，Y2 BaNiO5 ，CuB2 O4 におけるスピン状態と熱伝導”, 科研費特定領域「異常量子物質の創製 新しい物理を生む新物
質」成果報告会, 仙台, 1 月 (2006).
大平-河村聖子, 前川覚, 鍛治亮佑, 伊藤哲明: “量子スピ
ンカゴメ格子磁性体 Cu-titmb の µSR 測定”, 日本物理学会第 61 回年次大会, 松山, 3 月 (2006).
赤石義紀, 山崎敏光: “ケイオン核−批判に答えて”, 日
本物理学会第 61 回年次大会, 松山, 3 月 (2006).
鈴木栄男, 渡邊功雄, 藤原崇雄, 大沢明, 後藤貴行, 山田
文子, 田中秀数: “量子スピン系 Tl1−x Kx CuCl3 (x =0.2) における µSR 測定”, 日本物理学会第 61 回年次大会, 愛媛大学, 3 月 (2006).
吉川明子, 勝又紘一, 本多善太郎, 渡邊功雄, 鈴木栄男,
松 崎 禎 市 郎: “ス ピ ン ラ ダ ー 物 質
Na2 Co2 (C2 O4 )3 (H2 O)2 の µSR 測定”, 日本物理学会
2006 年秋季大会, 千葉, 9 月 (2006).
大平-河村聖子, 齋藤麻優美, 宮坂等: “µSR 法でみたII
MnIII
2 -Ni 型単一次元鎖磁石のスピンダイナミクス”,
日本物理学会 2006 年秋季大会, 千葉, 9 月 (2006).
小池貴久, 原田融: “3 He 標的を用いた (in-ﬂight K− , n)反応の DWIA 計算”, 日本物理学会 2006 年秋季大会,(日本物理学会), 奈良, 9 月 (2006).
岩崎雅彦: “KpX から K 核へ”, 日本物理学会 2006 年秋
季大会, (日本物理学会), 奈良, 9 月 (2006).
松本琢磨, 緒方一介, 江上智晃, 井芹康統, 八尋正信, 上村
正康: “6He 核力・クーロン分解反応の解析”, 日本物理学会 2006 年秋季大会, 奈良, 9 月 (2006).
石田勝彦: “理研 RAL ミュオン施設での研究の現状”, 仁科加速器研究センター原子核グループ月例コロキウム,
和光, 10 月 (2006).
蜂谷健一: “充填スクッテルダイト 31 P-NMR/µSR”, ボ
トムアップ若手の会第 1 回研究会：物理・化学・生物の融合を目指して, 和光, 11 月 (2006).
川股隆行, 宮島祐一, 高橋伸雄, 野地尚, 小池洋二, 工藤
一貴, 小林典男: “5 本足スピン梯子格子系 La8 Cu7 O19とハルデンギャップ系 Y2 BaNiO5 におけるスピンによる熱伝導”, ボトムアップ若手の会第 1 回研究会：物理・化学・生物の融合を目指して, 和光, 11 月 (2006).
川股隆行, 宮島祐一, 高橋伸雄, 野地尚, 小池洋二, 工藤
一貴, 小林典男: “5 本足スピン梯子格子系 La8 Cu7 O19とハルデンギャップ系 Y2 BaNiO5 におけるスピンによる熱伝導”, 東大物性研短期研究会「量子スピン系の物理」, 柏, 11 月 (2006).
松本琢磨, 江上智晃, 緒方一介, 井芹康統, 八尋正信, 上村
正康: “不安定核分解反応による di-neutron 相関の研究”, RCNP 研究会「核子多体系におけるクラスター現象」, (大阪大学核物理研究センター), 大阪, 2 月 (2007).
小池貴久, 原田融: “3 He 標的を用いた (in-ﬂight K− ,n)反応の DWIA 計算 II”, 日本物理学会 2007 年春季大会, 八王子, 3 月 (2007).

Theoretical Physics Lab.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Ishimoto Y.: “Two-point functions and logarithmic
boundary operators in boundary logarithmic conformal ﬁeld theories”, J. High Energy Phys. 8, 039-1–
039-22 (2004). ＊Kinoshita T. and Nio M.: “Improved α4 term of themuon anomalous magnetic moment”, Phys. Rev. D
70, 113001-1–113001-27 (2004). ＊Matsuo T. and Matsuura S.: “String Theoretical Interpretation for Finite N Yang-Mills Theory in Two
Dimensions”, Mod. Phys. Lett. A 20, No. 1, pp. 29–
41 (2005). ＊Kobayashi S., Asakawa T., and Matsuura S.: “Openstring tachlon in supergravity solution”, Mod. Phys.
Lett. A 20, No. 15, pp. 1119–1134 (2005). ＊Ishimoto Y. and Yamaguchi S.: “Minimal string theory is logarithmic”, Phys. Lett. B 607, 172–179(2005). ＊Chu C., Furuta K., and Inami T.: “Locality, causality
and noncommutative geometry”, Int. J. Mod. Phys.
A 21, No. 1, pp. 67–82 (2006). ＊Asakawa T., Matsuura S., and Kobayashi S.: “Excited
D-Branes and Supergravity Solutions”, Int. J. Mod.
Phys. A 21, No. 7, pp. 1503–1527 (2006). ＊Aoyama T., Hayakawa M., Kinoshita T., and Nio M.:“Automated calculation scheme for αn contributionsof QED to lepton g −2: generating renormalized amplitudes for diagrams without lepton loops”, Nucl.
Phys. B 740, 138–180 (2006). ＊Aoyama T. and Shibusa Y.: “Improved perturbation method and its application to the IIB matrix
model”, Nucl. Phys. B 754, 48–90 (2006). ＊Aoyama T., Hayakawa M., Kinoshita T., and Nio M.:“Automated calculation scheme for αn contributionsof QED to lepton g−2”, Nucl. Phys. B (Proc. Suppl.)
157, 106–110 (2006). ＊Kinoshita T. and Nio M.: “Improved α4 term of theelectron anomalous magnetic moment”, Phys. Rev.
D 73, 013003-1–013003-28 (2006). ＊Chu C., Furuta K., and Lin F.: “Nonlocal matchingcondition and scale-invariant spectrum in bouncing
cosmology”, Phys. Rev. D 73, 103505-1–103505-14(2006). ＊Eto M., Konishi K., Marmorini G., Nitta M., OhashiK., Vinci W., and Yokoi N.: “Non-Abelian vorticesof higher winding numbers”, Phys. Rev. D 74, No.
6, pp. 065021-1–065021-19 (2006). ＊Fukaya H., Hashimoto S., Ishikawa K., Kaneko T.,
Matsufuru H., Onogi T., and Yamada N.: “Latticegauge action suppressing near-zero modes of HW ”,
Phys. Rev. D 74, 094505-1–094505-10 (2006). ＊Aoyama T., Kuroki T., and Shibusa Y.: “Dynamical generation of non-Abelian gauge group via the- 366 -

improved perturbation theory”, Phys. Rev. D 74,
106004-1–106004-14 (2006). ＊Doi T., Blum T. C., Hayakawa M., Izubushi T., andYamada N.: “The Isospin breaking eﬀect on baryons
with N(f) = 2 domain wall fermions”, Proceedingsof Science LAT2006, 174-1–174-7 (2006). ＊Shibusa Y., Aoyama T., and Matsuo T.: “Improved
Taylor Expansion Method in the Ising Model”, Prog.
Theor. Phys. 115, No. 3, pp. 473–486 (2006). ＊Hayakawa M. and Suzuki H.: “Gauge anomaly associated with the Majorana fermion in 8k + 1 dimensions”, Prog. Theor. Phys. 115, No. 6, pp. 1129–1136(2006). ＊Hanada M., Kawai H., and Kimura Y.: “Curved superspaces and local supersymmetry in supermatrix
model”, Prog. Theor. Phys. 115, 1003–1025 (2006).
＊
Hanada M., Kanai T., Kawai H., and Kubo F.: “Phase
structure of the large-N reduced gauge theory andgeneralized Weingarten model”, Prog. Theor. Phys.
115, 1167–1177 (2006). ＊Aoyama T., Kawai H., and Shibusa Y.: “Stability of
4-dimensional space-time from the IIB matrix model
via the improved mean ﬁeld approximation”, Prog.
Theor. Phys. 115, 1179–1187 (2006). ＊Hayakawa M., So H., and Suzuki H.: “Overlap lattice
fermion in a gravitational ﬁeld”, Prog. Theor. Phys.
116, No. 1, pp. 197–215 (2006). ＊Aoyama T. and Kawai H.: “Higher order terms in the
improved mean ﬁeld approximation for the IIB matrix model and the emergence of four-dimensional
space-time”, Prog. Theor. Phys. 116, No. 2, pp. 405–
415 (2006). ＊Fukaya H., Hayakawa M., Kanamori I., Suzuki H., andTakimi T.: “Note on massless bosonic states in twodimensional ﬁeld theories”, Prog. Theor. Phys. 116,
No. 6, pp. 1117–1129 (2006). ＊(Review)
鈴木博: “格子ゲージ理論におけるカイラル対称性の実現”, 日本物理学会誌 61, No. 11, pp. 807–814 (2006).
[Book・Proc.](Others)
Ishimoto Y.: “Logarithmic correlation functions andmoduli integrals in 2D minimal gravity”, Proceedings of 4th International Symposium on Quantum
Theory and Symmetries, Varna, Bulgaria, 2005–
8, The Bulgarian Journal of Physics, Heron Press,
Soﬁa, pp. 353–359 (2006).
Oral Presentations(International Conference etc.)
Ishimoto Y.: “Logarithmic correlation functions inminimal string theory”, International Workshop “Integrable Models and Applications”, (European Collaboration Linking Integrability with other Disciplines 2002 - 2006), Sozopol, Bulgaria, Aug.–Sept.
(2003).

Furuta K.: “Locality and evolution of cosmologicalperturbations”, Summer School on Strings, (National Taiwan University), Taipei, Taiwan, July
(2005).
Kuroki T. and Kawai H.: “Dijkgraaf-Vafa theory aslarge-N reduction”, 4th International Symposium on
Quantum Theory and Symmetries, (QTS), Varna,
Bulgaria, Aug. (2005).
Furuta K.: “Locality and evolution of cosmologicalﬂuctuation”, YITP workshop on String Theory and
Quantum Field Theory, (Yukawa Institute for Theoretical Physics ), Kyoto, Aug. (2005).
Doi T., Blum T. C., Hayakawa M., Izubushi T., andYamada N.: “Isospin breaking of baryon masses
from domain-wall lattice QCD”, 2nd Joint Meetingof the Nuclear Physics Divisions of the APS and JPS(Hawaii 2005), Maui, USA, Sept. (2005).
Furuta K.: “Locality and evolution of cosmologicalﬂuctuation”, 12th Vietnam School of Physics Workshop on Physics for Large and Small Scale, (Instituteof physics and electronics), Hanoi, Vietnam, Jan.
(2006).
Kanamori I., D’Adda A., Kawamoto N., Nagata K.,
and Saito J.: “Hermiticity and Majorana condition for two-dimensional super Yang-Mills on alattice with Dirac-Kähler twist”, Joint Meetingof Paciﬁc Region Particle Physics Communities(DPF2006+JPS2006), (American Physical Society
and Physical Society of Japan), Honolulu, USA,
Oct.–Nov. (2006).
Eto M., Konishi K., Marmorini G., Nitta M.,
Ohashi K., Vinci W., and Yokoi N.: “NonAbelian Duality from Vortex Moduli”, Joint Meeting of Paciﬁc Region Particle Physics Communities (DPF2006+JPS2006), (American Physical Society and Physical Society of Japan), Honolulu, USA,
Oct.–Nov. (2006).
Fukaya H.: “Approaching the chiral limit in lattice
QCD”, 2006 International Workshop SCGT 06 “Origin of Mass and Strong Coupling Gauge Theories”,(Nagoya University), Nagoya, Nov. (2006).
(Domestic Conference)
青山龍美, 早川雅司, 木下東一郎, 仁尾真紀子: “QED
Tenth-order contributions to the lepton g − 2”, 日本
物理学会第 61 回年次大会, 松山, 3 月 (2006).
澁佐雄一郎, 青山龍美, 黒木経秀: “改良された摂動論による行列模型におけるゲージ対称性の破れ”, 日本物理学会第 61 回年次大会, 松山, 3 月 (2006).
澁佐雄一郎, 青山龍美, 松尾俊寛: “改良テーラー展開法
における相転移”, 日本物理学会第 61 回年次大会, 松山, 3 月 (2006).
尾田欣也: “Black hole production at collider”, 京都大学基礎物理学研究所研究会「素粒子物理の進展」, 京
都, 7–8 月 (2006).
仁尾真紀子: “量子電気理学の最前線”, 2006 年度日本物理学会科学セミナー「朝永振一郎と 21 世紀の物理学：
量子と時空の生み出す多様性」, 東京, 8 月 (2006).

- 367 -

花田政範, 古田黄, 川合光, 木村祐介: “Matrix modeland ﬁeld equations of massless ﬁelds in bosonicstring theory”, 理研シンポジウム「行列模型と弦理論」, 和光, 9 月 (2006).
小西憲一, Marmorini G., Vinci W., 横井直人: “ZN vortices in N = 1∗ SU(N) gauge theory”, 2006 年度京都大学基礎物理学研究所研究会「弦理論と場の量子論における新たな進展」, 京都, 9 月 (2006).
尾田欣也: “Smoothing out negative tension brane”,
2006 年度京都大学基礎物理学研究所研究会「弦理論と場の量子論における新たな進展」, 京都, 9 月 (2006).
金森逸作: “Hermiticity and Majorana condition for
two-dimensional super Yang-Mills on a lattice with
Dirac-Kaehler twist”, 2006 年度基礎物理学研究所研究会「場の量子論の基礎的諸問題と応用」, (京都大学
基礎物理学研究所), 京都, 12 月 (2006).
衛藤稔, Ferretti L., 小西憲一, Marmorini G., 新田宗土,
大橋圭介, Vinci W., 横井直人: “Non-abelian duality
from vortex moduli”, 2006 年度基礎物理学研究所研究会「場の量子論の基礎的諸問題と応用」, (京都大学
基礎物理学研究所), 京都, 12 月 (2006).
深谷英則: “Topology in lattice QCD”, 2006 年度基礎物理学研究所研究会「場の量子論の基礎的諸問題と応用」, (Yukawa Institute for Theoretical Physics,
Kyoto University), Kyoto, 12 月 (2006).

Accelerator Applications Research Gr.
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Nakamura T., Wada M., Okada K., Ishida Y.,
Takamine A., Yamazaki Y., Kambara T., Kanai
Y., Kojima T., Nakai Y., Oshima N., Yoshida A.,
Kubo T., Katayama I., Lioubimov V., Wollnik H.,
Varentsov V., and Schuessler H. A.: “Laser spectroscopy of 7,10 Be+ in an online ion trap”, Phys.
Rev. A 74, 052503-1–052503-5 (2006). ＊(Review)
神原正: “重イオン照射による超音波の観測：イオンビー
ム地震学”, 日本物理学会誌 61, No. 8, pp. 594–598(2006).
Oral Presentations(International Conference etc.)
Kambara T., Kanai Y., Kojima T., Nakai Y., Yoneda
A., and Yamazaki Y.: “Elastic waves from fastheavy-ion irradiation on solids”, 18th International
Acoustic Emission Symposium, Sagamihara, July
(2006).
Radiation Biology Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Umebayashi Y., Honma M., Abe T., Ryuto H., Suzuki

H., Shimazu T., Ishioka N., Iwaki M., and YatagaiF.: “Mutation induction after low-dose carbon-ion
beam irradiation of frozen cultured cells”, Biol. Sci.
Space 19, No. 4, pp. 237–241 (2005). ＊Ikeda T., Kanai Y., Kojima T., Iwai Y., Kambara T.,
Yamazaki Y., Hoshino M., Nebiki T., and Narusawa
T.: “Production of a microbeam of slow highly
charged ions with a tapered glass capillary”, Appl.
Phys. Lett. 89, 163502-1–163502-3 (2006). ＊Takehisa H., Ueda T., Fukuta Y., Obara M., Abe T.,
Yano M., Yamaya T., Kameya T., Higashitani A.,
and Sato T.: “Epistatic interaction of QTLs controlling leaf bronzing in rice (Oryza sativa L.) groun in asaline paddy ﬁeld”, Breed. Sci. 56, 287–293 (2006).
＊
Hokura A., Onuma R., Kitajima N., Terada Y., Saito
H., Abe T., Yoshida S., and Nakai I.: “2-D X-ray
ﬂuorescence imaging of cadmium hyperaccumulating plants by using high-energy synchrotoron radiation X-ray microbeam”, Chem. Lett. 35, No. 11, pp.
1246–1247 (2006). ＊Honda I., Kikuchi K., Matsuo S., Fukuda M., Saito
H., Ryuto H., Fukunishi N., and Abe T.: “Heavyion-induced mutants in sweet pepper isolated by M1
plant selection”, Euphytica 152, No. 1, pp. 61–66(2006). ＊Kazama Y., Sugiyama R., Suto Y., Uchida W., andKawano S.: “The clustering of four subfamilies ofsatellite DNA at individual chromosome ends in Silene latifolia”, Genome 49, 520–530 (2006). ＊Ryuto H., Abe T., Fukunishi N., Kase M., and YanoY.: “Heavy-ion beam irradiation system for biological samples in RIKEN”, Journal of Biomedical Nanotechnology 2, No. 2, pp. 88–93 (2006).
Miyazaki K., Suzuki K., Iwaki K., Kusumi T., Abe T.,
Yoshida S., and Fukui H.: “Flower pigment mutations induced by heavy ion beam irradiation in aninterspeciﬁc hybrid of Torenia”, Plant Biotechnol.
23, No. 2, pp. 163–167 (2006). ＊Nakano M., Nomizu T., Mizunashi K., Suzuki M., Mori
S., Kuwayama S., Hayashi M., Umehara H., Oka E.,
Kobayashi H., Asano M., Sugawara S., Takagi H.,
Saito H., Nakata M., Godo T., Hara Y., and AmanoJ.: “Somaclonal variation in Tricyrtis hirta plants
regenerated from 1-year-old embryogenic callus cultures”, Sci. Hortic. 110, 366–371 (2006). ＊Ichida H., Matsuyama T., Abe T., and Koba T.:“DNA adenine methylation changes dramaticallyduring establishment of symbiosis”, The FEBS Journal 274, 951–962 (2007). ＊柏原輝彦, 保倉明子, 北島信行, 小沼亮子, 斉藤宏之, 阿部知子, 中井泉: “放射光蛍光 X 線分析を用いるヒ素高集積植物モエジマシダの根におけるヒ素の分布および化学形態分析”, 分析化学 55, No. 10, pp. 743–748(2006). ＊(Review)
阿部知子, 林依子, 市田裕之, 龍頭啓充: “理研仁科加速- 368 -

器研究センターにおける重イオン加速器を用いた植物育種の実用化”, 加速器 3, No. 1, pp. 69–73 (2006).
[Book・Proc.](Original Papers) ＊ Subject to Peer Review
Bae C., Lyu J., Abe T., Yano Y., Yoshida S., Lee
Y., and Lee H.: “Eﬀect of heavy-ion beam irradiation on in vitro cultured plant organisms”, Proceedings of the 3rd Asian Particle Accelerator Conference (APAC 2004), Gyeongju, Korea, 2004–3, APAC
2004, Gyeongju, pp. 444–445 (2004). ＊(Review)
Uchida W., Kazama Y., Matsunaga S., and Kawano
S.: “A Wonder Plant-Microbe Interaction between
White Campion and Anther Smut”, Floriculture,
Ornamental and Plant Biotechnology: Advances
and Topical Issues (1st Edition), London, UK, 2006–
Jaime A. Teixeira da Silva, Kagawa, pp. 236–242(2006).
松山知樹, 市田裕之, 阿部知子, 浅見忠男, 中山秀人, 小池
邦昭, 戎崎俊一: “ゲノムスキャニング多型解析によるシロイヌナズナ突然変異体の変異遺伝子迅速同定”,
DNA 多型, Vol.14, 日本 DNA 多型学会, 東京, pp.
144–146 (2006).
市田裕之, 米山勝美, 阿部知子, 松山知樹: “キャベツ萎
黄病抵抗性 DNA マーカー周辺領域の解析”, DNA 多型, Vol.14, 日本 DNA 多型学会, 東京, pp. 147–150(2006).
阿部知子, 龍頭啓充: “重イオンビームを用いた植物の品種改良法の実用化”, 第 30 回放射線科学研究会資料
集, 大阪, 2006–7, 大阪ニュークリア, 大阪, pp. 17–22(2006).
阿部知子: “各種園芸植物のイオンビームによる育種研究の成果”, 第 8 回加速器利用技術セミナー「ビーム利用による農業・工業・医療の新時代」講演テキスト, 東
海村, 2006–10, 放射線利用振興協会, 高崎, pp. 47–51(2006).
(Others)
Onuma R., Hokura A., Kitajima N., Nakai I., Terada
Y., Abe T., Saito H., and Yoshida S.: “Arsenic distribution and speciation in the arsenic hyperaccumulator fern by Micro-XRF imaging and Micro-XANES
analysis”, IPAP Conference series 7: Proceedings of
8th International Conference on X-ray Microscopy(XRM2005), Himeji, 2005–7, Institute of Pure andApplied Physics, Japan, Hyogo, pp. 326–327 (2006).

Oral Presentations(International Conference etc.)
Yatagai F., Umebayashi Y., Honma M., Abe T.,
Suzuki H., Shimazu T., Ishioka N., and Iwaki M.:“A plan for ISS experiment to detect microgravity effects on mutation induction in relation to space radiation”, 27th Annual Gravitational Physiology Meeting, (International Society for Gravitational Physiology), Osaka, Apr. (2006).
Yatagai F., Umebayashi Y., Honma M., Suzuki M.,
Abe T., Suzuki H., Shimazu T., Ishioka N., andIwaki M.: “Sensitive Mutation-Detection in Human
Cell for Space Environmental Radiation”, 4th International Workshop on Space Radiation Researchand 17th Annual NASA Space Radiation Health Investigators’ Workshop, Moscow and St. Petersburg,
Russia, June (2006).
Yatagai F., Umebayashi Y., Honma M., Abe T.,
Suzuki H., Shimazu T., Ishioka N., and Iwaki M.:“An application of LOH analysis for detecting thegenetic inﬂuences of space environmental radiation”,
36th COSPAR Scientiﬁc Assembly, Beijing, China,
July (2006).
Yatagai F., Umebayashi Y., Honma M., Suzuki M.,
Abe T., Suzuki H., Shimazu T., Ishioka N., andIwaki M.: “Inﬂuences of low-dose and low-doserate ionizing radiation on the mutation induction
in human cell”, COSPAR COLLOQUIUM on Mutagenic Consequences of the Space Environment, Xian,
China, July (2006).
Lyu J., Abe T., Han H., Jung J., Lee H., Shin D.,
and Bae C.: “Identiﬁcation of speciﬁc DNA bands invariegated orchid rhizomes induced by ion beam irradiation”, 27th International Horticultural Congress
and Exhibition, (International Society for Horticultural Science), Seoul, Korea, Aug. (2006).
Saito H., Hayashi Y., Fukunishi N., Ryuto H., Suzuki
K., Kanaya T., Sugiyama M., Terakawa T., OhtsuboN., Aida R., and Abe T.: “Isolation of sterile mutants of ﬂoricultural plants using heavy-ion
beam irradiation”, 27th International Horticultural
Congress and Exhibition, (International Society for
Horticultural Science), Seoul, Korea, Aug. (2006).
Kanai Y., Hoshino M., Ikeda T., Kambara T.,
Hellhammer R., Stolterfoht N., and Yamazaki Y.:“Two-dimensional images of slow neon ions guided
by nanocapillaries in polymer foils”, 16th International Workshop on Inelastic Ion-Surface Collisions(IISC-16), Hernstein, Austria, Sept. (2006).
(Domestic Conference)
竹久妃奈子, 上田忠正, 福田善通, 阿部知子, 矢野昌裕,
山谷知行, 佐藤雅志: “塩害水田におけるイネ葉身のBronzing の発症を支配する 2QTL 間の相互作用”, 日
本育種学会第 109 回講演会, 東京, 3 月 (2006).
金子 博, 松田 靖, Poeaim A., 阿部 知子, 村田 達郎:“Zoysia minima におけるイオンビーム照射の影響”,
日本育種学会第 109 回講演会, 東京, 3 月 (2006).
本多一郎, 菊地都, 松尾哲, 福田真知子, 林依子, 斉藤
宏之, 阿部知子: “処理当代より見出したピーマン重イオン変異体の遺伝解析”, 園芸学会平成 18 年度春季大会, 千葉, 3 月 (2006).
大沼みお, 横山敬士, 井上貴之, 市田裕之, 林依子, 阿部知子, 関根靖彦, 田中寛: “C イオンビーム照射による
Cyanidioschyzon merolae の URA5.3 遺伝子変異株の取得”, 第 3 回イオンビーム育種研究会大会, 千葉, 4
月 (2006).
大越一雄, 伊藤靖之, 関栄一, 渡邉学, 阿部知子: “重イオンビームを用いたベゴニア突然変異体の作出”, 第 3- 369 -

回イオンビーム育種研究会大会, 千葉, 4 月 (2006).
大坪憲弘, 間竜太郎, 阿部知子: “イオンビーム照射を利用した色変わり組換えトレニアの高品位化”, 第 3 回
イオンビーム育種研究会大会, 千葉, 4 月 (2006).
市田裕之, 木庭卓人, 米山勝美, 松山知樹, 阿部知子:“DNA 二次元電気泳動による植物関連細菌ゲノムの網羅的変異解析法の開発”, 平成 18 年度日本植物病理学会大会, 札幌, 6 月 (2006).
阿部知子: “重イオンビームを用いた植物育種の実用化”,
KEK セミナー, つくば, 6 月 (2006).
阿部知子, 龍頭啓充: “重イオンビームを用いた植物の品
種改良法の実用化”, 第 30 回放射線科学研究会, (大阪ニュークリアサイエンス協会), 大阪, 7 月 (2006).
大坪憲弘, 間竜太郎, 阿部知子: “遺伝子組換え花きへの重イオンビーム照射による効率的な花色・花形変異の導入”, 第 24 回日本植物細胞分子生物学会大会・シンポジウム, つくば, 7 月 (2006).
竹久妃奈子, 阿部知子, 林依子, 神波千秋, 斉藤宏之, 市田
裕之, 小沼亮子, 龍頭啓充, 福西暢尚, 宮沢豊, 東海林英夫, 保倉明子, 福田直樹, 中井泉, 佐藤雅志: “重イオンビーム照射による塩害水田耐性イネ突然変異系
統の作出”, 日本育種学会第 110 回講演会, 松山, 9 月(2006).
大坪憲弘, 山口博康, 間竜太郎, 阿部知子: “重イオンビー
ム照射を利用した色変わり組換えトレニアの効率的なバラエティ化”, 日本育種学会第 110 回講演会, 松山,
9 月 (2006).
齋藤利弥, 揚村京子, 波越啓太, 市田裕之, 林依子, 阿部
知子, 西村実, 一谷勝之, 久保山勉: “イネ雑種弱勢原因遺伝子 Hwc2 の高密度連鎖解析と弱勢抑制変異体の染色体欠損領域について”, 日本育種学会第 110 回講演会, 松山, 9 月 (2006).
白尾吏, 上野敬一郎, 松山知樹, 市田裕之, 阿部知子: “イオンビーム育種により育成した秋輪ギク品種「新神」のレトロトランスポゾン配列を利用した品種同定”, 日
本育種学会第 110 回講演会, 松山, 9 月 (2006).
阿部知子, 林依子, 竹久妃奈子, 安田美智子, 市田裕之,
斉藤宏之, 柏原輝彦, 福田直樹, 小沼亮子, 保倉明子,
寺田靖子, 龍頭啓充, 福西暢尚, 宮沢豊, 仲下英雄, 工藤
俊章, 中井泉, 佐藤雅志: “イネにおける加速器を用いた変異誘発法および変異体解析法の開発”, 日本育種学会第 110 回講演会, 松山, 9 月 (2006).
西原潔, 風間裕介, 小泉綾子, 河野重行, 阿部知子: “重イオンビームを用いた雌雄異株植物ヒロハノマンテマの性転換変異体の作出”, 日本育種学会第 110 回講演会,(日本育種学会), 松山, 9 月 (2006).
田平千香子, 漆川直希, 阿部知子, 阪本浩一, 斉藤宏之,
龍頭啓充, 福西暢尚, 村井耕二: “イオンビームによる一粒系コムギ突然変異体 fushi-darake の表現型および遺伝解析”, 日本育種学会第 110 回講演会, 松山, 9 月(2006).
高橋昌宏, 松田靖, 阿部知子, 村田達郎: “ニラ (Allium
ramosum L.) におけるイオンビーム照射の影響”, 日
本育種学会第 110 回講演会, 松山, 9 月 (2006).
市田裕之, 松山知樹, 龍頭啓充, 福西暢尚, 阿部知子, 木庭
卓人: “根粒菌における突然変異誘発とその網羅的検出”, 植物微生物研究会 第 16 回研究交流会, 札幌, 9 月(2006).
谷田貝文夫, 梅林志浩, 本間正充, 阿部知子, 鈴木ひろみ,
嶋津徹, 石岡憲昭, 岩木正哉: “ISS 利用実験計画：宇宙環境の変異誘発に及ぼす影響の推測”, 日本放射線影響学会第 49 回大会, (日本放射線影響学会), 札幌, 9
月 (2006).
小泉綾子, 西原潔, 天内康人, 石井公太郎, 風間裕介, 河野
重行: “ヒロハノマンテマの無性花変異体と黒穂菌感
染擬似雄蕊誘導体における B 機能遺伝子の発現”, 日本植物学会第 70 回大会, (日本植物学会), 熊本, 9 月(2006).
風間裕介, 西原潔, 石井公太郎, 貴舩永津子, 西山りゑ,河野重行: “ヒロハノマンテマの XY 性染色体上の対立遺伝子 SlAP3 と SlWUS の位置と構造比較”, 日本植物学会第 70 回大会, (日本植物学会), 熊本, 9 月 (2006).
西原潔, 風間裕介, 西山りゑ, 河野重行: “雌雄異株植物
ヒロハノマンテマの XY 性染色体に連鎖する AP3 と他のホモログ”, 日本遺伝学会第 78 回大会, つくば, 9
月 (2006).
天内康人, 石井公太郎, 小泉綾子, 風間裕介, 河野重行:“雌雄異株植物ヒロハノマンテマの染色体末端サテラ
イト DNA 構造の非一様性とその近傍を用いた FISH
解析”, 日本遺伝学会第 78 回大会, つくば, 9 月 (2006).
阿部知子: “各種園芸植物のイオンビームによる育種研究の成果”, 第 8 回加速器利用技術セミナー, (文部科学省), 東海村, 10 月 (2006).
阿部知子: “理化学研究所加速器を用いた植物の品種改
良法の実用化”, 第 3 回大学発シーズ発表会, (木原記
念横浜生命科学振興財団), 横浜, 11 月 (2006).
市田裕之, 松山知樹, 龍頭啓充, 福西暢尚, 林依子, 阿部知子, 木庭卓人: “重イオンビームによって誘発された
DNA 多型の解析”, 日本 DNA 多型学会第 15 回学術集会, (日本 DNA 多型学会), 福山, 11 月 (2006).
西原潔, 石井公太郎, 小泉綾子, 風間裕介, 河野重行: “雌雄異株植物ヒロハノマンテマの XY 性染色体連鎖遺伝
子と性染色体構造の比較”, 文部科学省科学研究費補
助金特定領域研究「植物の生殖過程におけるゲノム障壁」第 1 回ワークショップ/国立遺伝学研究所研究集会/「高等植物の生殖形質におけるゲノム障壁制御遺伝
子の分子遺伝学的解析」, 三島, 11 月 (2006).
風間裕介, 西原潔, 小泉綾子, 河野重行, 阿部知子: “高エネルギー重イオンビーム照射によるヒロハノマンテマ
性転換変異体の作出”, 文部科学省科学研究費補助金特定領域研究「植物の生殖過程におけるゲノム障壁」第1 回ワークショップ/国立遺伝学研究所研究集会/「高等植物の生殖形質におけるゲノム障壁制御遺伝子の分子遺伝学的解析」, 三島, 11 月 (2006).
小泉綾子, 天内康人, 石井公太郎, 西原潔, 風間裕介, 河野
重行: “ヒロハノマンテマ無性花変異体 K034 の 2 つの表現型と Y 染色体欠損”, 文部科学省科学研究費補
助金特定領域研究「植物の生殖過程におけるゲノム障壁」第 1 回ワークショップ/国立遺伝学研究所研究集会/「高等植物の生殖形質におけるゲノム障壁制御遺伝
子の分子遺伝学的解析」, 三島, 11 月 (2006).
阿部知子: “シンクロトロン光の農業利用の可能性−植物における重金属観察および突然変異育種”, 平成 18
年度技術ワークショップ事業「シンクロトロン光利活- 370 -

用勉強会」, (佐賀県立九州シンクロトロン光研究センター), 佐賀, 11 月 (2006).
阿部知子: “イオンビーム育種技術の開発”, 第 25 回法政大学イオンビーム工学研究所シンポジウム, (法政大学
イオンビーム工学研究所), 小金井, 12 月 (2006).
遠藤隆, 那須田周平, 河原太八, 安井康夫, 笹隈哲夫, 笹沼
恒男, 辻本壽, 田中裕之, 持田恵一, 川浦香奈子, 荻原
保成: “NBRP「コムギ」複雑系ゲノム科学のモデル
植物”, 第 28 回日本分子生物学会年会, 福岡, 12 月
(2006).

RI Applications Team
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Tanaka M. and Takahashi K.: “Study on the saltingout eﬀect using silica species by FAB-MS”, J. Solution Chem. 36, 27–37 (2007). ＊Haba H., Tsukada K., Asai M., Toyoshima A., Ishii
Y., Toume H., Sato T., Nishinaka I., Ichikawa
T., Ichikawa S., Nagame Y., Sato W., Matsuo K.,
Kitamoto Y., Tashiro T., Shinohara A., Saito J.,
Ito M., Ikezawa T., Sakamaki M., Goto S., Kudo
H., Kikunaga H., Arai M., Kamataki S., Yokoyama
A., Akiyama K., Sueki K., Oura Y., Schaedel M.,
Bruechle W., and Kratz J. V.: “Extraction behavior of rutherfordium into tributylphosphate from hydrochloric acid”, Radiochim. Acta 95, 1–6 (2007). ＊榎本香織, 金山洋介, 木村修一, 榎本秀一: “食肉成分が胃液分泌に及ぼす影響”, 微量栄養素研究 23, 74–76(2006). ＊金山洋介, 羽場宏光, 榎本秀一, 天野良平: “コルヒチンによる 24 Na, 28 Mg, 43 K, 47 Ca, 48 V, 67 Cu 嗅覚輸送阻害効果の検討”, 微量栄養素研究 23, 84–88 (2006).
＊(Others)
Nagame Y., Akiyama K., Asai M., Goto S., Haba
H., Hirata M., Ishii Y., Nishinaka I., Tome H.,
Toyoshima A., and Tsukada K.: “Chemical studiesof the transactinide elements at JAEA”, AIP Conf.
Proc. 865, 165–172 (2006).
Haba H., Tsukada K., Asai M., Toyoshima A., Ishii
Y., Tome Y., Sato T., Nishinaka I., Ichikawa T.,
Ichikawa S., Nagame Y., Sato W., Matsuo K.,
Kitamoto Y., Tashiro T., Shinohara A., Saito J.,
Ito M., Ikezawa T., Sakamaki M., Goto S., Kudo
H., Kikunaga H., Arai M., Kamataki S., Yokoyama
A., Akiyama K., Sueki K., Oura Y., Schaedel M.,
Bruechle W., and Kratz J. V.: “Extraction behaviorof Rf into tributylphosphate from hidrochloric acid”,
JAEA-Review 2006, No. 29, pp. 57–58 (2006).
Tsukada K., Toyoshima A., Haba H., Asai M.,
Akiyama K., Ishii Y., Tome Y., Nishinaka I., SatoT., Ichikawa S., Nagame Y., Yaita T., Goto S.,
Ikezawa T., Sato W., Matsuo K., Kitamoto Y.,
Tashiro T., Yokoyama A., Arai M., Sakama M.,

Oura Y., Sueki K., Shinohara A., and Kudo H.:“Chloride complex formation of Rf in HCl andCH3 OH mixed solution”, JAEA-Review 2006, No.
29, pp. 61–62 (2006).
[Book・Proc.](Others)
Nagame Y., Haba H., Tsukada K., Asai M., Toyoshima
A., Akiyama T., Kaneko T., Hirai T., Goto
S., Hirata M., Nishinaka I., and Ichikawa S.:“Few atom chemistry of the transactinide element
rutherfordium (Rf)”, Proceedings of the International Conference on Applications of High Precision
Atomic and Nuclear Methods, 2-6 September 2002,
Neptun, Romania, Neptun, Romania, 2002–9, IFINHH, Bucharest, pp. 334–343 (2005).
Nagame Y., Asai M., Haba H., Hirata M., Ishii
Y., Nishinaka I., Toyoshima A., and Tsukada K.:“Aqueous Chemistry of the Transactinide Element,
Rutherfordium (Rf)”, Lecture Series on Computerand Computational Sciences Volume 7, Brill Academic Publishers, Leiden, pp. 927–930 (2006).
前田邦子: “機器分析の事典：波長分散型蛍光 X 線分析装置”, 機器分析の事典, 朝倉書店, 東京, pp. 37–40(2005).
Oral Presentations(International Conference etc.)
Kikunaga H., Haba H., Kaji D., Sato N., Akiyama T.,
Morimoto K., Yoneda A., Morita K., Takabe T., Ooe
K., Shinohara A., Suzuki D., Nanri T., YamazakiI., and Yokoyama A.: “Development of a gas-jet
transport system coupled to GARIS for heavy element chemistry”, 5th Workshop on Recoil Separator
for Superheavy Element Chemistry (TASACA06),(GSI), Garching, Germany, Sept. (2006).
Haba H., Kaji D., Kikunaga H., Akiyama T., SatoN., Morimoto K., Yoneda A., Morita K., TakabeT., Tashiro Y., Kitamoto Y., Matsuo K., Saika D.,
Ooe K., Kuribayashi T., Yoshimura T., Shinohara
A., and Toyoshima A.: “Superheavy Element Chemistry at RIKEN: Present Status and Perspectives”,
Tours Symposium on Nuclear Physics VI (TOURS
2006), (Konan University), Tours, France, Sept.
(2006).
Toyoshima A., Tsukada K., Asai M., Ishii Y.,
Nishinaka I., Sato T., Hirata M., Nagame Y., Haba
H., Sato W., Tani Y., Hasegawa H., Matsuo K.,
Saika D., Kitamoto Y., Shinohara A., Goto S.,
Ito M., Saito J., Kudo H., Akiyama K., Sueki K.,
Yokoyama A., Oura Y., Schaedel M., Bruechle W.,
and Kratz J. V.: “Fluoride Complexation Study ofRutherfordium at JAEA”, Workshop on the Atomic
Properties of the Heaviest Elements: Towards the Island of Stability, (LMU Muenchen), Chiemsee, Germany, Sept. (2006).
Haba H., Kaji D., Kikunaga H., Akiyama T., SatoN., Morimoto K., Yoneda A., Morita K., Takabe- 371 -

T., Tashiro Y., Kitamoto Y., Matsuo K., Saika D.,
Ooe K., Kuribayashi T., Yoshimura T., Shinohara
A., and Toyoshima A.: “Startup of Heavy Element
Chemistry in RIKEN”, Workshop on the Atomic
Properties of the Heaviest Elements: Towards the Island of Stability, (LMU Muenchen), Chiemsee, Germany, Sept. (2006).
Ishii Y., Toume H., Toyoshima A., Asai M., Nishinaka
I., Tsukada K., Nagame Y., Tashiro T., Shinohara
A., Sakamaki M., Goto S., Kudo H., Akiyama K.,
Haba H., Oura Y., Miyashita S., Mori T., andSuganuma H.: “A cation-exchange study of ﬂuoride
complexation of rutherfordium (Rf) in HNO3/HF
mixed solution system”, 6th International Symposium on Advanced Science Research: Frontiersof Nuclear and Radiochemistry (ASR2006), (Advanced Science Research Center, Japan Atomic Energy Agency), Tokaimura, Oct. (2006).
Tsukada K., Toyoshima A., Haba H., Asai M.,
Akiyama K., Ishii Y., Tome H., Nishinaka I., Kaneko
T. S., Ichikawa S., Nagame Y., Yaita T., Goto
S., Ikezawa T., Sato W., Matsuo K., KitamotoY., Tashiro T., Yokoyama A., Arai M., Sakama
M., Oura Y., Sueki K., Shinohara A., and Kudo
H.: “Chloride complex formation of Rf in HCl andCH3OH mixed solution”, 6th International Symposium on Advanced Science Research: Frontiersof Nuclear and Radiochemistry (ASR2006), (Advanced Science Research Center, Japan Atomic Energy Agency), Tokaimura, Oct. (2006).
Haba H., Kikunaga H., Kaji D., Sato N., Akiyama T.,
Morimoto K., Yoneda A., Morita K., Takabe T., Ooe
K., Shinohara A., Suzuki D., Nanri T., Yamazaki I.,
and Yokoyama A.: “Development of a gas-jet transport system coupled to the RIKEN gas-ﬁlled recoil
ion separator GARIS for superheavy element chemistry”, 6th International Symposium on Advanced
Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006), (Advanced Science ResearchCenter, Japan Atomic Energy Agency), Tokaimura,
Oct. (2006).
Toyoshima A., Kasamatsu Y., Tsukada K., Haba H.,
Shinohara A., and Nagame Y.: “Development of
an electrochemistry apparatus for an atom-at-atime chemistry”, 6th International Symposium on
Advanced Science Research: Frontiers of Nuclear
and Radiochemistry (ASR2006), (Advanced Science
Research Center, Japan Atomic Energy Agency),
Tokaimura, Oct. (2006).
Kaji D., Haba H., Kikunaga H., Morimoto K., Yoneda
A., Akiyama T., Ooe K., Nanri T., Sato N.,
Shinohara A., Suzuki D., Takabe T., Yamazaki I.,
Yokoyama A., and Morita K.: “Optimazation of a
gas-ﬁlled recoil separator GARIS for the chemistry ofsuperheavy elements”, 6th International Symposium
on Advanced Science Research: Frontiers of Nuclear
and Radiochemistry (ASR2006), (Advanced Science

Research Center, Japan Atomic Energy Agency),
Tokaimura, Oct. (2006).
Takabe T., Saika D., Matsuo K., Tashiro T., Ooe
K., Kuribayashi T., Yoshimura T., ToyoshimaA., Kikunaga H., Kaji D., Haba H., Kudo H.,
Mitsugashira T., and Shinohara A.: “Studies on theheavy element productions at RIKEN for chemical
characterization of seaborgium”, 6th International
Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006),(Advanced Science Research Center, Japan Atomic
Energy Agency), Tokaimura, Oct. (2006).
Toyoshima A., Kasamatsu Y., Tsukada K., Haba H.,
Asai M., Ishii Y., Toume H., Kaneko T. S., Nishinaka
I., Nagame Y., Goto S., Ishiyama T., Sakamaki M.,
Kudo H., Akiyama K., Oura Y., Kikunaga H., Ooe
K., Kuribayashi T., Shinohara A., and Yokoyama
A.: “TOPO reversed-phase extraction behabior ofrutherfordium in HCl solutions”, 6th International
Symposium on Advanced Science Research: Frontiers of Nuclear and Radiochemistry (ASR2006),(Advanced Science Research Center, Japan Atomic
Energy Agency), Tokaimura, Oct. (2006).
(Domestic Conference)
北本優介, 雑賀大輔, 松尾啓司, 高部智正, 田代祐基, 大江一弘, 栗林隆宏, 佐藤渉, 高橋成人, 吉村崇, 羽場宏光,
榎本秀一, 三頭聰明, 篠原厚: “金属-配位子間相互作用を利用した 3 価アクチノイドのキャピラリー電気泳動分離”, 日本化学会第 86 春季年会, (日本化学会), 船橋, 3 月 (2006).
高部智正, 北本優介, 雑賀大輔, 松尾啓司, 田代祐基, 大江一弘, 栗林隆宏, 吉村崇, 羽場宏光, 加治大哉, 篠原厚:
“理研 AVF サイクロトロンにおける重元素合成シス
テムの整備と化学研究のためのノーベリウム同位体の製造”, 日本化学会第 86 春季年会, (日本化学会), 船橋,
3 月 (2006).
塚田和明, 豊嶋厚史, 羽場宏光, 浅井雅人, 秋山和彦, 石井康雄, 當銘勇人, 西中一朗, 佐藤哲也, 市川隆敏, 市川進一, 平田勝, 永目諭一郎, 矢板毅, 後藤真一, 坂牧
雅巳, 池沢孝明, 佐藤渉, 松尾啓司, 北本優介, 田代
祐基, 横山明彦, 新井理太, 鎌滝真次, 阪間稔, 大浦
泰嗣, 末木啓介, 篠原厚, 工藤久昭: “超重元素ラザホー
ジウムの塩化物錯体形成”, 日本化学会第 86 春季年会,(日本化学会), 船橋, 3 月 (2006).
豊嶋厚史, 羽場宏光, 塚田和明, 浅井雅人, 秋山和彦, 石井康雄, 當銘勇人, 西中一朗, 佐藤哲也, 市川隆敏, 永目
諭一郎, 佐藤渉, 松尾啓司, 北本優介, 田代祐基, 篠原厚, 池沢孝明, 坂牧雅巳, 後藤真一, 工藤久昭, 新井理太, 鎌滝真次, 横山明彦, 大浦泰嗣, 末木啓介: “塩酸溶液系におけるラザホージウムの TBP 逆相抽出ク
ロマトグラフィー”, 日本化学会第 86 春季年会, (日本化学会), 船橋, 3 月 (2006).
金山洋介, 羽場宏光, 榎本秀一, 天野良平: “24 Na, 28 Mg,
43
K, 47 Ca, 48 V, 67 Cu 鼻腔投与におけるコルヒチンの嗅覚輸送阻害効果の検討”, 第 23 回微量栄養素研究会
シンポジウム, 京都, 6 月 (2006).
金山洋介, 榎本秀一, 羽場宏光, 天野良平: “Brain Deliv-- 372 -

ery of Monovalent Metal Cations via Olfactory Pathway”, 第 16 回金属の関与する生体関連反応シンポジ
ウム (SRM 2006)「生体超分子システムと金属」, (日本薬学会), 東京, 6 月 (2006).
石井康雄, 當銘勇人, 豊嶋厚史, 浅井雅人, 西中一朗, 塚田
和明, 永目諭一郎, 宮下直, 森友隆, 菅沼英夫, 田代
祐基, 篠原厚, 坂牧雅巳, 後藤真一, 工藤久昭, 羽場
宏光, 秋山和彦, 大浦泰嗣: “Rf の HNO3/HF における陽イオン交換挙動 (II)”, 2006 日本放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月 (2006).
豊嶋厚史, 笠松良崇, 塚田和明, 羽場宏光, 篠原厚, 永目
諭一郎: “単一原子の電気化学的研究に向けた電解セルの開発”, 2006 日本放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月
(2006).
高部智正, 雑賀大輔, 松尾啓司, 田代祐基, 大江一弘, 栗林
隆宏, 吉村崇, 豊嶋厚史, 菊永英寿, 加治大哉, 羽場
宏光, 工藤久昭, 三頭聰明, 篠原厚: “理研におけるシー
ボーギウム化学研究に向けた重元素合成”, 2006 日本
放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月 (2006).
菊永英寿, 羽場宏光, 加治大哉, 佐藤望, 森本幸司, 米田
晃, 森田浩介, 高部智正, 大江一弘, 篠原厚, 鈴木大介,
南里朋洋, 山崎逸郎, 横山明彦: “238U(22Ne,5n) 反応によって製造された 255No の GARIS による分離分
析：GARIS を前段分離装置として用いた超重元素化学研究に向けて”, 2006 日本放射化学会年会・第 50 回
放射化学討論会, (日本放射化学会), 水戸，東海村, 10
月 (2006).
田代祐基, 雑賀大輔, 北本優介, 松尾啓司, 高部智正, 栗林
隆宏, 大江一弘, 吉村崇, 佐藤渉, 高橋成人, 豊嶋厚史,
羽場宏光, 篠原厚: “複線式マイクロチップを用いた
No2+迅速溶媒抽出”, 2006 日本放射化学会年会・第50 回放射化学討論会, (日本放射化学会), 水戸，東海
村, 10 月 (2006).
大江一弘, 栗林隆宏, 高部智正, 田代祐基, 北本優介, 雑賀大輔, 松尾啓司, 高橋成人, 吉村崇, 高宮幸一, 柴田
誠一, 羽場宏光, 榎本秀一, 篠原厚: “極低濃度タング
ステンの溶媒抽出挙動と電解酸化還元反応”, 2006 日
本放射化学会年会・第 50 回放射化学討論会, (日本放射化学会), 水戸，東海村, 10 月 (2006).
豊嶋厚史, 笠松良崇, 塚田和明, 羽場宏光, 浅井雅人,
石井康雄, 當銘勇人, 金子 (哲也) 佐藤, 西中一朗, 永目
諭一郎, 後藤真一, 石山剛, 坂牧雅巳, 工藤久昭, 秋山
和彦, 大浦泰嗣, 菊永英寿, 大江一弘, 栗林隆宏, 篠原厚, 末木啓介, 横山明彦: “塩酸溶液系におけるラザ
ホージウムの TOPO 逆相抽出クロマトグラフ挙動”,
2006 日本放射化学会年会・第 50 回放射化学討論会,(日本放射化学会), 水戸，東海村, 10 月 (2006).
前田邦子, 浜中廣見, 荻原清, 長谷川賢一: “結晶分光
PIXE で化学状態の深さ分布を調べる”, 第 23 回 PIXE
シンポジウム, (PIXE 研究協会), 松島, 11 月 (2006).
川畑俊明, 鳥山保, 川崎克則, 長谷川賢一, 前田邦子, 小栗
慶之: “固体高分子型燃料電池中の硫黄の分析用波長
分散型粒子線誘起 X 線分析システムの構築”, 第 23 回
PIXE シンポジウム, (PIXE 研究協会), 松島, 11 月

(2006).
Safety Management Gr.
Oral Presentations(Domestic Conference)
坂本久雄, 堀米敦子, 向井弘樹, 日暮利江子, 藤田新, 上蓑
義朋, 加瀬昌之: “理研 RIBF におけるウラン加速の安全管理”, 第 3 回日本加速器学会年会・第 31 回リニアック技術研究会, 仙台, 8 月 (2006).
RIKEN BNL Research Center
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Bazilevsky A. V. and PHENIX Collaboration .: “Event
reconstruction in the PHENIX central arm spectrometers”, Nuclear Instruments and Methods inPhysics Research A 482, 491–512 (2002). ＊Adcox K., Bazilevsky A. V., Bunce G. M., DeshpandeA., En’yo H., Fox B., Goto Y., Grosse Perdekamp
M., Hayashi N., Ichihara T., Imai K., Ishihara
M., Jacak B. V., Kobayashi H., Kurita K., Li Z.,
Mao Y., Murata J., Saito N., Sakuma T., Sato H.,
Shibata T., Sugioka M., Taketani A., Tojo J., Torii
H., Watanabe Y., Yokkaichi S., and PHENIX C.:“PHENIX detector overview”, Nuclear Instruments
and Methods in Physics Research A 499, 469–479(2003). ＊Aphecetche L., Bazilevsky A. V., Goto Y., Grosse
Perdekamp M., and PHENIX Collaboration .:“PHENIX Calorimeter”, Nuclear Instruments andMethods in Physics Research A 499, 521–536(2003). ＊Akikawa H., En’yo H., Hayashi N., Ichihara T.,
Ishihara M., Kobayashi H., Kurita K., Li Z., Mao Y.,
Murata J., Saito N., Sato H., Shibata T., Sugioka
M., Taketani A., Watanabe Y., Yokkaichi S., and
PHENIX Collaboratio .: “PHENIX muon arms”,
Nuclear Instruments and Methods in Physics Research A 499, 537–548 (2003). ＊Allen M., Deshpande A., Fox B., and PHENIX C.:“PHENIX inner detectors”, Nuclear Instruments
and Methods in Physics Research A 499, 549–559(2003). ＊Adler S. S., Ichihara T., Jacak B. V., WatanabeY., Yokkaichi S., and PHENIX C.: “PHENIX online and oﬀ-line computing”, Nuclear Instruments
and Methods in Physics Research A 499, 593–602(2003). ＊Murata J., Horaguchi T., Kamihara N., Kobayashi H.,
Shibata T., and PHENIX C.: “Optical alignment
system for the PHENIX muon tracking chambers”,
Nuclear Instruments and Methods in Physics Research A 500, 309–317 (2003). ＊Okiharu F., Suganuma H., Takahashi T. T., and Doi- 373 -

T.: “Multi-quarks and two-baryon interaction in lattice QCD”, AIP Conf. Proc. 842, 231–233 (2006). ＊Doi T., Takahashi T. T., and Suganuma H.: “Mesonmeson and meson-baryon interactions in lattice
QCD”, AIP Conf. Proc. 842, 246–248 (2006). ＊Takahashi T. T., Doi T., and Suganuma H.: “Nuclear
force in lattice QCD”, AIP Conf. Proc. 842, 249–251(2006). ＊Ishii N., Doi T., Iida H., Oka M., Okiharu F.,
Suganuma H., and Tsumura K.: “Anisotropic lattice QCD studies of penta-quarks and tetra-quarks”,
AIP Conf. Proc. 842, 492–494 (2006). ＊Aoki S., Baer O., and Takeda S.: “Vector meson
masses in 2+1 ﬂavor Wilson Chiral Perturbation
Theory”, Phys. Rev. D 73, No. 9, pp. 094501-1–
094501-11 (2006). ＊Aoki S., Baer O., Takeda S., and Ishikawa T.: “Pseudoscalar meson masses in Wilson chiral perturbation
theory for 2+1 ﬂavors”, Phys. Rev. D 73, No. 165,
pp. 014511-1–014511-15 (2006). ＊Aoki S. and Baer O.: “Automatic O(a) improvement
for twisted-mass QCD in the presence of spontaneous symmetry breaking”, Phys. Rev. D 74, No.
3, pp. 034511-1–034511-17 (2006). ＊Iida K. and Fukushima K.: “Instability of a gaplesscolor superconductor with respect to inhomogeneous
ﬂuctuations”, Phys. Rev. D 74, 074020-1–074020-13(2006). ＊Iida H., Doi T., Ishii N., Suganuma H., and Tsumura
K.: “Charmonium properties in deconﬁnement
phase in anisotropic lattice QCD”, Phys. Rev. D 74,
074502-1–074502-12 (2006). ＊Bai M., Roser T., Ahrens L., Alekseev I. G., Alessi J.,
Beebe-Wang J., Blaskiewicz M., Bravar A., Brennan
J. M., Bruno D., Bunce G. M., Courant E., Drees A.,
Fischer W., Gardner C., Gill R., Glenn J., HaeberliW., Huang H., Jinnouchi O., Kewisch J., Luccio A.,
Luo Y., Nakagawa I., Okada H., Pilat F., MacKay
W. W., Makdisi Y., Montag C., Ptitsyn V., Satogata
T., Stephenson E., Svirida D., Tepikian S., Trbojevic
D., Tsoupas N., Wise T., Zelenski A., Zeno K.,
and Zhang S. Y.: “Polarized Proton Collisions at
205 GeV at RHIC”, Phys. Rev. Lett. 96, 174801-1–
174801-4 (2006). ＊Aoki S. and Baer O.: “Automatic O(a) improvement for twisted-mass QCD”, Proceedings of Science
LAT2006, No. 165, (2006).
Doi T., Blum T. C., Hayakawa M., Izubushi T., andYamada N.: “The Isospin breaking eﬀect on baryons
with N(f) = 2 domain wall fermions”, Proceedingsof Science LAT2006, 174-1–174-7 (2006). ＊四日市悟, Chiba J., 延与秀人, 深尾祥紀, 舟橋春彦,
浜垣秀樹, Ieiri M., Ishino M., Kanda H., 北口雅暁,
Mihara S., Miyashita T., 三輪浩司, 村上哲也, 武藤亮太郎, Nakura T., 成木恵, 小沢恭一郎, 佐久間史典,
Sasaki O., 関本美知子, 田原司睦, Tanaka K., 外川学,
Yamada S., Yoshimura Y.: “Experimental Study of

in-medium meson modiﬁcation at the KEK 12 GeVPS”, 素粒子論研究 114, No. 2, pp. B7–B12 (2006).
Oral Presentations(International Conference etc.)
Ishii N., Doi T., Iida H., Oka M., Okiharu F.,
and Suganuma H.: “Penta-quark anti-decuplet inanisotropic lattice QCD”, LATTICE 2004: 22ndInternational Symposium on Lattice Field Theory,(Fermi National Accelerator Laboratory), Batavia,
USA, June (2004).
Doi T., Ishii N., Oka M., and Suganuma H.: “The lattice QCD simulation of the quark-gluon mixed condensate gq̄σµν Gµν q at ﬁnite temperature and thephase transition of QCD”, LATTICE 2004: 22ndInternational Symposium on Lattice Field Theory,
Batavia, USA, June (2004).
Ishii N., Doi T., Iida H., Oka M., Okiharu F., andSuganuma H.: “Anisotropic lattice QCD studies ofpenta-quark anti-decuplet”, International Workshop
on PENTAQUARK04, (RCNP and JASRI), Harima
Science Garden City, July (2004).
Sugiyama J., Doi T., and Oka M.: “Pentaquark baryon
from the QCD sum rule with the ideal mixing”,
International Workshop on PENTAQUARK04,(RCNP and JASRI), Harima Science Garden City,
July (2004).
Doi T., Sugiyama J., and Oka M.: “Penta-quark
baryon from the QCD sum rule”, 2004 Gordon
Research Conference on Photonuclear Reactions,
Tilton, USA, Aug. (2004).
Doi T., Ishii N., Oka M., and Suganuma H.:“Thermal eﬀects on quark-gluon mixed condensate gq̄σµν Gµν q from lattice QCD”, 2004 Gordon Research Conference on Photonuclear Reactions, Tilton, USA, Aug. (2004).
Ishii N., Doi T., Iida H., Oka M., Okiharu F., andSuganuma H.: “Penta-quark in anisotropic lattice
QCD”, 10th International Conference on the Structure of Baryons (Baryons 2004), Palaiseau, France,
Oct. (2004).
Oka M., Sugiyama J., and Doi T.: “Pentaquark
baryons in the QCD sum rule”, 10th International
Conference on the Structure of Baryons (Baryons
2004), Palaiseau, France, Oct. (2004).
Tabaru T.: “Heavy Quark and J/ψ Production at
RHIC/PHENIX”, 5th International Conference on
Physics and Astrophysics of Quark Gluon Plasma(ICPAQGP 05), Salt Lake City, India, Feb. (2005).
Okiharu F., Doi T., Ichie H., Iida H., Ishii N., Oka M.,
Suganuma H., and Takahashi T. T.: “Tetraquarkand pentaquark systems in lattice QCD”, Quark Nuclear Physics 2005: Nuclear and Hadronic Systems
and Quark Degrees of Freedom, Pyoungchang, Korea, Feb. (2005).
Iida H., Doi T., Ishii N., and Suganuma H.: “J/Ψ athigh temperatures in anisotropic lattice QCD”, 23rd

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International Symposium on Lattice Field Theory(Lattice 2005), Dublin, Ireland, July (2005).
Doi T., Ishii N., Nemoto Y., Oka M., and Suganuma
H.: “Anisotropic lattice QCD study of pentaquark
baryons in spin 3/2 channel”, 23rd International
Symposium on Lattice Field Theory (Lattice 2005),
Dublin, Ireland, July (2005).
Ishii N., Doi T., Nemoto Y., Oka M., and Suganuma
H.: “Anisotropic lattice QCD studies of spin 3/2
penta-quark”, 2nd Joint Meeting of the Nuclear
Physics Divisions of the APS and JPS (Hawaii 2005),
Maui, USA, Sept. (2005).
Fukushima K.: “Collective excitations in a superﬂuid
of color-ﬂavor locked quark matter”, 2nd Joint Meeting of the Nuclear Physics Divisions of the APS and
JPS (Hawaii 2005), Maui, USA, Sept. (2005).
Doi T., Blum T. C., Hayakawa M., Izubushi T.,
and Yamada N.: “Isospin breaking of baryon masses
from domain-wall lattice QCD”, 2nd Joint Meetingof the Nuclear Physics Divisions of the APS and JPS(Hawaii 2005), Maui, USA, Sept. (2005).
Okada K. and PHENIX C.: “Measurement of Direct
Photons in sqrt(s)=200 GeV p+p collisions”, 2ndJoint Meeting of the Nuclear Physics Divisions of
the APS and JPS (Hawaii 2005), Maui, USA, Sept.
(2005).
Sugiyama J., Doi T., and Oka M.: “QCD sum rule forspin-3/2 pentaquarks”, 2nd Joint Meeting of the Nuclear Physics Divisions of the APS and JPS (Hawaii2005), Maui, USA, Sept. (2005).
Ishii N., Doi T., Iida H., Nemoto Y., Oka M., Okiharu
F., Suganuma H., and Tsumura K.: “Anisotropic
lattice QCD studies of penta-quarks and tetraquarks”, Particles and Nuclei International Conference (PANIC05), Santa Fe, USA, Oct. (2005).
Doi T., Takahashi T. T., and Suganuma H.: “Mesonmeson and meson-baryon interactions in lattice
QCD”, Particles and Nuclei International Conference (PANIC05), Santa Fe, USA, Oct. (2005).
Okiharu F., Suganuma H., Takahashi T. T., and Doi
T.: “Multi-quarks and two-baryon interactions inlattice QCD”, Particles and Nuclei International
Conference (PANIC05), Santa Fe, USA, Oct. (2005).
Takahashi T. T., Doi T., and Suganuma H.: “Nuclear
force in lattice QCD”, Particles and Nuclei International Conference (PANIC05), Santa Fe, USA, Oct.
(2005).
Aoki S.: “Lattice QCD simulations with light
dynamical quarks”, Quark Conﬁnment and the
Hadron Spectrum 7 (Acores-2006), (Universidade
dos Azores), Ponta Delgada Azores, Portugal, Sept.
(2006).
(Domestic Conference)
小濱洋央, 飯田圭, 親松和浩: ““黒い” 原子核描像に基づく核半径と反応断面積”, RIBF-Day1 実験を睨んだ反
応断面積実験に向けたミニワークショップ, Wako, 1
月 (2006).

岡田謙介, PHENIX C.: “Measurement of Direct
Photon Production in p+p collisions at sqrt(s)=200 GeV”, 日本物理学会 2006 年秋季大会, 奈良, 9 月(2006).

RIKEN Facility Oﬃce at RAL
Publications[Journal](Original Papers) ＊ Subject to Peer Review
Suzuki T., Itahashi K., Iwasaki M., Matsuda Y.,
Okada S., Outa H., Sato M., Strasser P., Tomono
D., and Yamazaki T.: “A search for deeply boundkaonic nuclear states”, Nucl. Phys. A 754, 375c–
382c (2005). ＊Tonishi J., Suzuki T., and Goto T.: “Anomalous Change of Hall Coeﬃcient in Overdoped
La2−x Srx Cu1−y Zny O4 around x = 0.2”, AIP Conf.
Proc. 850, 407–408 (2006). ＊Suzuki T., Ota T., Tonishi J., and Goto T.: “Increase of the sound velocity by magnetic ﬁelds inLa2−x Srx CuO4 around x = 0.220”, AIP Conf. Proc.
850, 409–410 (2006). ＊Inoue H., Tani S., Hosoya S., Suzuki T., Goto T.,
Tanaka H., Sasaki T., and Kobayashi N.: “2 D,
35/37
Cl, 63/65 Cu-NMR Study of the Quantum Spin
System NH4 CuCl3 ”, AIP Conf. Proc. 850, 1061–
1062 (2006). ＊Suzuki T., Saito T., Sasaki T., Osawa A., Goto T.,
Awaji S., Watanabe K., Kobayashi N., and Manaka
H.: “Magnetic ﬁeld eﬀect on the magnetic torqueand the magnetostriction in (CH3 )2 CHNH3 CuCl3 ”,
J. Phys.: Con. Ser. 51, 187–190 (2006). ＊Fujiwara T., Inoue H., Osawa A., Tsunoda R., Goto
T., Suzuki T., Shindo Y., Tanaka H., Sasaki T.,
Kobayashi N., Awaji S., and Watanabe K.: “CuNMR study on the disordered quantum spin magnet
with the Bose-glass ground state”, J. Phys.: Con.
Ser. 51, 199–202 (2006). ＊Tonishi J., Ueda M., Suzuki T., Osawa A., Goto
T., Adachi T., Koike Y., Fujita M., and Yamada
K.: “Local structure in single crystals of La-based
high Tc cuprates”, J. Phys.: Con. Ser. 51, 275–278(2006). ＊Suzuki T., Fujiwara T., Osawa A., Goto T., YamadaF., Tanaka H., and Watanabe I.: “Muon-SpinRelaxation study on single crystals Tl1−x Kx CuCl3
with x = 0.2”, J. Phys. Soc. Jpn. 75, No. 2, pp.
025001-1–025001-2 (2006). ＊Hachitani K., Fukazawa H., Kohori Y., Watanabe I.,
Yoshimitsu Y., Kumagai K., Giri R., Sekine C.,
and Shirotani I.: “31 P-NMR and µSR studies ofﬁlled skutterudite compound SmFe4 P12 :evidence forheavy fermion behavior with ferromagnetic groundstate”, J. Phys. Soc. Jpn. 75, No. 12, pp. 124717-1–
124717-5 (2006). ＊Attwood D., Bell P., Bull S., McMahon T., Wilson- 375 -

J., Fernow R., Gruber P., Jamdagni A., Long K.,
McKigney E., Savage P., Curtis-Rouse M., Edgecock
T. R., Ellis M., Lidbury J., Murray W., Norton
P., Peach K., Ishida K., Matsuda Y., Nagamine K.,
Nakamura S., Marshall G. M., Benveniste S., Cline
D., Fukui Y., Lee K., Pischalnikov Y., Holmes S.,
and Bogacz A.: “The scattering of muons in lowZ materials”, Nucl. Instrum. Methods Phys. Res. B
251, 41–55 (2006). ＊Matsuda Y., Bakule P., Iwasaki M., Matsuzaki T.,
Miyake Y., Ikedo Y., Strasser P., Simomura K.,
Makimura S., and Nagamine K.: “Generation of lowenergy muons with laser resonant ionization”, Nucl.
Phys. B (Proc. Suppl.) 155, 346–348 (2006). ＊Hachitani K., Fukazawa H., Kohori Y., Watanabe I.,
Sekine C., and Shirotani I.: “Evidence for magnetic
ordering associated with metal-insulator transitionin SmRu4 P12 studied by muon spin relaxation”,
Phys. Rev. B 73, 052408-1–052408-4 (2006). ＊Saito T., Osawa A., Goto T., Suzuki T., and Watanabe
I.: “Muon spin rotation and relaxation studies
on the solid solution of the two spin-gap systems(CH3 )2 CHNH3 -CuCl3 and (CH3 )2 CHNH3 -CuBr3 ”,
Phys. Rev. B 74, 134423-1–134423-5 (2006). ＊Torikai E., Ito A., Watanabe I., and Nagamine K.:“µSR studies on the response of spin dynamics toapplying or removing magnetic ﬁeld — Typical Ising
spin glass Fe0.05 Mn0.05 TiO3 ”, Physica B 374/375,
95–98 (2006). ＊Bakule P., Matsuda Y., Iwasaki M., Miyake Y.,
Nagamine K., Ikedo Y., Simomura K., and Strasser
P.: “Pulsed source of ultra low-energy muons at
RIKEN-RAL”, Physica B 374/375, 456–459 (2006).
＊
Miyake Y., Nishiyama K., Kawamura N., Makimura
S., Strasser P., Simomura K., Beveridge J. L.,
Kadono R., Fukuchi K., Sato N., Ueno K.,
Higemoto W., Ishida K., Matsuzaki T., Watanabe I.,
Matsuda Y., Iwasaki M., Nakamura S., Doornbos J.,
and Nagamine K.: “Status of J-PARC muon sciencefacility at the year of 2005”, Physica B 374/375,
484–487 (2006). ＊Oral Presentations(International Conference etc.)
Matsuda Y.: “Generation of ultra slow muon beam bylaser resonant ionization of muonium atoms”, 6thInternational Workshop on Neutrino Factories andSuperbeams (NuFact 04), Osaka, July–Aug. (2004).
Suzuki T., Ota T., Tonishi J., and Goto T.: “Increase of the sound velocity by magnetic ﬁelds inLa2−x Srx CuO4 around x = 0.220”, 24th International Conference on Low Temperature Physics(LT24), (Department of Physics, University of
Florida), Orlando, USA, Aug. (2005).
Kikkawa A., Katsumata K., Honda Z., Watanabe I.,
Suzuki T., and Matsuzaki T.: “Evolution of thespin-gap in a spin-ladder material detected by muSR
technique”, 1st International Symposium of Quantum Beam Science Directorate of JAEA (ICM2006
Satellite Conference), (JAEA), Tokai, Aug. (2006).
Ishida K.: “Muon catalyzed fusion”, 8th International Workshop on Neutrino Factories nd Superbeams (NuFact 06), (University of California,
Irvine), Irvine, USA, Aug. (2006).
Suzuki T., Watanabe I., Osawa A., Goto T., Yamada
F., and Tanaka H.: “Muon-Spin-Relaxation study
on randomness introduced Tl1−x Kx CuCl3 with x= 0.44”, An ICM2006 Satellite Conference: 1stInternational Symposium of Quantum Beam Science Directorate of JAEA, Advances in Neutron,
Synchrotron Radiation, µSR and NMR Researches(QuBS2006), (Quantum Beam Science Directorateof JAEA), Tokai, Aug. (2006).
Suzuki T., Saito T., Osawa A., Goto T., Sasaki T.,
Awaji S., Watanabe K., Kobayashi N., and Manaka
H.: “Magnetic ﬁeld eﬀect on the magnetic torqueand the magnetostriction in (CH3 )2 CHNH3 CuCl3 ”,
Yamada Conference LX on Research in High Magnetic Fields (RHMF2006), (High Field Laboratory
for Superconducting Materials Institute for Materials Research Tohoku University), Sendai, Aug.
(2006).
Matsuda Y.: “Progress of laser ionization methodfor LEM”, 1st Swiss Japan Workshop on the applications and on new developments in muon spectroscopy on novel materials, (High Energy Accelerator Research Organization), Tsukuba, Sept. (2006).
Bakule P.: “Laser ionization of muonium - pulsed ultra
low energy muon source for material studies”, International Conference on Laser Probing 2006 (LAP
2006), (Vienna University of Technology), Vienna,
Austria, Sept. (2006).
Ishida K.: “RIKEN-RAL, now and in the future”,
Workshop on future developments of European
muon sources, (NMI3), Abingdon, UK, Nov. (2006).
(Domestic Conference)
川股隆行, 菅原直樹, Haidar S. M., 高橋伸雄, 宮島
祐一, 野地尚, 小池洋二, 工藤一貴, 小林典男, 藤井裕, 菊池彦光, 千葉明朗, Petrakovskii G., PopovM., Bezmaternikh L.: “La8 Cu7 O19 ，Y2 BaNiO5 ，CuB2 O4 におけるスピン状態と熱伝導”, 科研費特定領域「異常量子物質の創製 新しい物理を生む新物
質」成果報告会, 仙台, 1 月 (2006).
大平-河村聖子, 前川覚, 鍛治亮佑, 伊藤哲明: “量子スピ
ンカゴメ格子磁性体 Cu-titmb の µSR 測定”, 日本物理学会第 61 回年次大会, 松山, 3 月 (2006).
鈴木栄男, 渡邊功雄, 藤原崇雄, 大沢明, 後藤貴行, 山田
文子, 田中秀数: “量子スピン系 Tl1−x Kx CuCl3 (x =0.2) における µSR 測定”, 日本物理学会第 61 回年次大会, 愛媛大学, 3 月 (2006).
吉川明子, 勝又紘一, 本多善太郎, 渡邊功雄, 鈴木栄男,
松 崎 禎 市 郎: “ス ピ ン ラ ダ ー 物 質
Na2 Co2 (C2 O4 )3 (H2 O)2 の µSR 測定”, 日本物理学会- 376 -

2006 年秋季大会, 千葉, 9 月 (2006).
石田勝彦: “理研 RAL ミュオン施設での研究の現状”, 仁科加速器研究センター原子核グループ月例コロキウム,
和光, 10 月 (2006).
川股隆行, 宮島祐一, 高橋伸雄, 野地尚, 小池洋二, 工藤
一貴, 小林典男: “5 本足スピン梯子格子系 La8 Cu7 O19とハルデンギャップ系 Y2 BaNiO5 におけるスピンによる熱伝導”, ボトムアップ若手の会第 1 回研究会：物理・化学・生物の融合を目指して, 和光, 11 月 (2006).
川股隆行, 宮島祐一, 高橋伸雄, 野地尚, 小池洋二, 工藤
一貴, 小林典男: “5 本足スピン梯子格子系 La8 Cu7 O19とハルデンギャップ系 Y2 BaNiO5 におけるスピンによる熱伝導”, 東大物性研短期研究会「量子スピン系の物理」, 柏, 11 月 (2006).

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VII. LIST OF PREPRINTS(2006 Apr.–2007 Mar.)RIKEN-AF-NP & RIKEN-NC-NP
471 M. Yamaguchi, Y. Tagishi, Y. Aoki, T. Iizuka, T. Nagatomo, T. Shinba, N. Yoshimaru, Y. Yamato, T.
Katabuchi, and M. Tanifuji: “Analyzing power for 6Li(d, arufa)4He and 6Li(d, p)7Li reactions at a low
incident energy”
472 S. Forte and Y. Goto: “SPIN PHYSICS”
473 T. Nakamura, M. Wada, K. Okada, A. Takamine, Y. Ishida, Y. Yamazaki, T. Kambara, Y. Kanai, T. M.
Kojima, Y. Nakai, N. Oshima, A. Yoshida, T. Kubo, S. Ohyani, K. Noda, T. Katayama, V. Lioubinov, H.
Wollnik, V. Varenysov, and A. Scuessler: “Laser spectroscopy of 7,10Be+ in an online ion trap”
1 W. Horiuchi, Y. Suzuki, B. Abu-Ibrahim, and A. Kohama: “Sysematic analysis of reaction cross sections ofcarbon isotopes”
2 K. Morita, K. Morimoto, D. Kaji, T. Akiyama, S. Goto, H. Haba, E. Ideguchi, K. Katori, H. Koura, H.
Kudo, T. Onishi, A. Ozawa, T. Suda, K. Sueki, F. Tokanai, T. Yamaguchi, A. Yoneda, and A. Yoshida:“Experiments on Synthesis of an Isotope 277112 by 208Pb + 70Zn Reaction”
3 K. Morita, K. Morimoto, D. Kaji, T. Akiyama, S. Goto, H. Haba, E. Ideguchi, K. Katori, H. Koura, H.
Kudo, T. Onishi, A. Ozawa, N. Sato, T. Suda, K. Sueki, F. Tokanai, T. Yamaguchi, A. Yoneda, and A.
Yoshida: “Observation of Second Decay Chain from 273113”
4 Z. Elekes, Zs. Dombradi, N. Aoi, S. Bishop, Zs. Fulop, J. Gibelin, T. Gomi, Y. Hashimoto, N. Imai, N.
Iwasa, H. Iwasaki, G. Kalinka, Y. Kondo, A. A. Korsheninnikov, K> Kurita, M. Kurokawa, N. Matsui, T.
Motobayashi, T. Nakamura, T. Nakao, E. Yu, Nikolskii, T. K. Ohnishi, T. Okumura, S. Ota, A. Perera,
A. Saito, H. Sakurai, Y. Satou, D. Sohler, T. Sumikama, D. Suzuki, M. Suzuki, H. Takeda, S. Takeuchi,
Y. Togano, and Y. Yanagisawa: “Spectroscopic stucy of neutron shell closures via nucleon transfer in thenear-dripline nucleus 23O”
5 J. Gibelin, D. Bernnel, T. Motobayashi, N. Aoi, H. Baba, Y. Blumenfeld, Zs. Dombradi, Z. Elekes, S.
Fortier, N. Fracaria, N. Fukuda, T. Gomi, K. Ishikawa, Y. Kondo, T. Kubo, V. Lima, T. Nakamura, A.
Saito, Y. Satou, E. Takeshita, S. Takeuchi, T. Teranishi, Y. Togano, A. M. Vinodkumar, Y. Yanagisawa,
and K. Yoshida: “Measurement of the B(E2,0+1->2+1) in the N=16 nucleus 26Ne”
6 D. Kameda, H. Ueno, K. Asahi, M. Takemura, A. Yoshimi, T. Haseyama, M. Uchida, K. Shimada, D. Nagae,
G. Kijima, T. Arai, K. Takase, S. Suda, T. Inoue, J. Murata, H. Kawamura, Y. Kobayashi, H. Watanabe,
and M. Ishihara: “Measurement of the electric quadrupole moment of 23AL”

RIKEN-AF-AC
Not Applicable- 379 -

VIII. LIST OF SYMPOSIA(2006 Apr.–2007 Mar.)
1) Second expert meeting on critical issues on next-generation high-intensity fragment separators
10–13 May, Experimental Installations Operation Gr., RIKEN
2) Systematic Study of Island of Inversion Nuclei by AMD
22–23 May, User Liaison and Support Group, RIKEN
3) Experimental detail of p+6He(6Li)->n(p)+d+a (spectator) reaction
8 Jun., User Liaison and Support Group, RIKEN
4) RHIC Physics in the Context of the Standard Model
18–23 Jun., RIKEN BNL Research Center, USA
5) Folding model approach to nucleus-nucleus interactions and applications to nuclear reaction studies
23–24 Jun., User Liaison and Support Group, CNS, RIKEN
6) RIKEN Workshop on “Frontiers in the physics of quark-gluon plasma”
8–9 Jul., Enyo Radiation Lab., RIKEN
7) Simplified modeling of cluster-shell competition (SMSO) in C-isotopes
14–15 Jul., User Liaison and Support Group, RIKEN
8) QCD in Extreme Conditions
31 Jul.–2 Aug., RIKEN BNL Research Center, USA
9) Matrix models and string theory
23 Sep., Theoretical Physics Laboratory, RIKEN
10) International Workshop on RHIC Spin Physics
29–30 Sep., Enyo Radiation Lab., RIKEN
11) 2nd German-Japanese Workshop on Nuclear Structure and Astrophysics
4–7 Oct., Nuclear Physics Research Div., RIKEN
12) CNS-GRAPE collaboration for high-resolution gamma-ray spectroscopy at RIBF
16–17 Oct., User Liaison and Support Group, RIKEN
13) RIBF International Collaboration Workshop
6–9 Nov., Nuclear Physics Research Div., RIKEN
14) Present status and strategy at RIBF
17–18 Nov., User Liaison and Support Group, RIKEN
15) Hyperfine structure of alkali atoms in superfluid helium
30 Nov.–1 Dec., User Liaison and Support Group, RIKEN
16) In-beam gamma spectroscopy of the doubly magic nucleus 78Ni and its vicinity
6 Feb., User Liaison and Support Group, RIKEN
17) Large-Scale Self-Consistent Nuclear Mass Calculations
23–24 Feb., User Liaison and Support Group, RIKEN18) Analysis of 8B elastic scattering experiments
2 Mar., User Liaison and Support Group, RIKEN- 381 -

19) International Workshop: Joint JUSTIPEN-LACM Meeting
5–8 Mar., Nuclear Physics Research Div., Oak Ridge (USA)20) Channelling of hydrogen by using nuclear reactions
15 Mar., User Liaison and Support Group, RIKEN21) Domain Wall Fermions at en Years
15–17 Mar., RIKEN BNL Research Center, USA
22) Resent development and future prospect of the GEM based tracking detector
23 Mar., Advanced Meson Science Laboratory/Cosmic Radiation Laboratory, RIKEN- 382 -

IX. LIST OF SEMINARS(2006 Apr.–2007 Mar.)“Search for an isomer state of Th-229 with extremely low energy alpha-spectrometry”

Accelerator Division
1) Dr. Andrew M. Sessler (Lawrence Berkeley National Laboratory (USA)), 2 Oct.
“A Century of Particle Accelerators”

9) Dr. Takashi Sugimoto (RIKEN Nishina Center),
16 May“Invariant-mass spectroscopy of the neutron dripline nucleus 14B”

2) Dr. Takamichi Aoki (The University of Tokyo),
23 Mar.
“Design and Construction of a rebuncher for
RIKEN RI Beam Factory”

10) Dr. Claudia Hoehne (GSI, Germany), 17 May“The high baryon density CBM experiment andother QCD related research activities at the future FAIR facility in Germany”

3) Dr. Lukas Stingelin (Japan society for the Promotion of Science), 23 Mar.
“Study of new ﬂattop resonator for RRC”

11) Dr. Yasuo Funaki (RIKEN Nishina Center), 23
May“Alpha particle condensation in ﬁnite nuclei”

Nuclear Physics Research Division
1) Dr. Y. M. Zhao (Shanghai Jiao-Tong Univ.
(China)), 7 Apr.
“Dimension of the single-j shell conﬁgurations
and sum rules of angular momentum recoupling
coeﬃcients”
2) Dr. Shinya Wanajo (University of Tokyo), 13 Apr.
“The rp-process nucleosynthesis in core-collapse
supernovae”
3) Dr. Masahiko Iwasaki (RIKEN Nishina Center),
18 Apr.
“Physics developed using K-meson: from KEKPS to J-PARK”

12) Dr. Yasuhisa Abe (RCNP, Osaka University), 27
May“RIKEN Lecture Series on Nuclear Physics
Course III “Nuclear dynamics – nuclear fusion
and ﬁssion –” 1”13) Dr. Akito Saito (University of Tokyo), 30 May“Exotic cluster states in 12Be via α-inelastic scattering”
14) Dr. Makoto Ito (RIKEN Nishina Center), 30 May“Uniﬁed studies on structures and reactions inlight neutron-rich systems (Application to 10Be)”
15) Dr. Kazuo Horiuchi (Hirosaki University), 8 Jun.
“Ice core records of 10Be and solar activity in thepast”4) Dr. Koji Niita (RIST), 19 Apr.
“PHITS – a Particle and Heavy Ion Transport
code System - Models and Applications

16) Dr. Hironari Miyazawa (University of Tokyo), 13
Jun.
“Nuclear Forces and Three-Body Forces”

5) Dr. Takatoshi Ichikawa (RIKEN Nishina Center),
25 Apr.
“Barrier for cold-fusion production of superheavy
elements”

17) Dr. Kenichi Matsuyanagi (Kyoto University), 14
Jun.
“RIKEN Lecture Series on Nuclear Physics
Course II “Minimum of modern theory of nxuclear structure” 2”6) Dr. Takeshi Furukawa (RIKEN Nishina Center),
25 Apr.
“Spin physics of atoms and nuclei immersed in superﬂuid helium with laser spectroscopic method”
7) Dr. Yoichi Nakai (RIKEN Nishina Center), 9 May“Fast ion – C60 collision and resonant coherent
excitation of fast ion: examples of atomic physics
experiments using accelerators”
8) Dr. Hidetoshi Kikunaga (RIKEN Nishina Center), 16 May

18) Dr. Genji Hirata (Denken-Seiki Co., Ltd), 16 Jun.
“Foundation and practical technique of noise
trouble measures”
19) Dr. Atsushi Kitagawa (N.I.R.S.), 20 Jun.
“Research for medical applications of the secondary beam at HIMAC”
20) Dr. Yoshiya Furusawa (N.I.R.S.), 20 Jun.
“Biological eﬀect of 9C radio-active beam”- 383 -

21) Dr. Satoru Terashima (RIKEN Nishina Center),
12 Jul.
“Deduced nuclear density distributions by using
proton elastic scattering”

33) Dr. A. Nasirov (JINR, Russia), 2 Nov.
“Inﬂuence of the entrance channel dynamics on
the evaporation residue formation in reaction ofmassive nuclei”

22) Dr. Takashi Nagatomo (RIKEN Nishina Center),
12 Jul.
“Search for the second class current by the precise
measurement of the beta-ray angular distributionof the mirror pair 20F and 20Na”

34) Dr. Tetsuo Hatsuda (Univesity of Tokyo), 2 Nov.
“Quantum Chromodynamics at Extreme Conditions”

23) Dr. Koji Kaya (RIKEN), 13 Jul.
“Nanometer Scale Chemistry: from Diatomic
Molecule to Giant Cluster”
24) Prof. Alexander Titov (JINL, RUSSIA/RCNP,
Osaka Univ.), 9 Aug.
“Θ formation in inclusive γ D → pK- X reaction”
25) Dr. Takashi Nakano (RCNP, Osaka University),
9 Aug.
“Status of the pentaquark search at LEPS”
26) Dr. Yasuo Yamamoto (Tsuru University), 21 Aug.
“How to make and use G-matrix interactions”
27) Associ. Prof. Badawy Abu-Ibrahim (Cairo Unv.),
5 Sep.
“Description of reaction cross sections in a parameter free eikonal model”
28) Dr. Hikaru Kawai (RIKEN Nishina Center), 12
Sep.
“String theory for amateurs: towards the theoryof everything”
29) Dr. Katsuhiko Ishida (RIKEN Nishina Center),
17 Oct.
“Recent Progress at the RIKEN-RAL Muon Facility”
30) Dr. Matthias Schaedel (GSI, Germany), 20 Oct.
“Superheavy Element Chemistry at GSI – Past,
Present and Future”
31) Prof. Guido Langouche (Institute for Radiation
and Nuclear Physics, Katholieke Universiteit Leuven, Belgium), 26 Oct.
“Lattice site determination of Er in Si and GaN
using electron emission channeling from radioactive isotopes produced at CERN ISOLDE”
32) Dr. Kazuhiro Oyamatsu (Aichi Shukutoku University), 31 Oct.
“Various phases of nuclear matter at around thenormal nuclear density and nuclear pasta”

35) Dr. Kenichi Matsuyanagi (Kyoto University), 24
Nov.
“RIKEN Lecture Series on Nuclear Physics
Course II “Minimum of modern theory of nuclear
structure” 3”36) Prof. Toichiro Kinoshita (Lab. for ElementaryPart. Phys., Cornell, USA), 28 Nov.
“Lepton g-2 and High Precision Test of QED –From 1947 to Present –”37) Prof. Richard Boyd (National Astronomical Observatory of Japan), 12 Dec.
“Supernova Neutrinos, Neutrino Properties, andr-and n-Process Nucleosynthesis”
38) Dr. Heiko Scheit (RI Physics Lab., RIKEN), 26
Dec.
“The New Radioactive Nuclear Beam Facility REX-ISOLDE/MINIBALL: Sub-Barrier
Coulomb Excitation of 30,32Mg and the “Islandof Inversion””
39) Dr. Noriyoshi Ishii (Center for Computational
Science, Tsukuba), 9 Jan.
“Nuclear Force from Lattice QCD”
40) Prof. Th. A. Rijken (Institute for Mathematics,
Astrophysics and Particle Physics, University of
Nijmegen, The Netherland), 9 Jan.
“Soft-core Baryon-baryon Interactions (ESCmodel at Low and Intermediate Energies)”
41) Prof. Paul Mantica (NSCL, MSU, USA), 16 Jan.
“Beta-decay studies and low-energy nuclear structure near Ca-48”
42) Prof. Yoji Ohashi (Keio University), 23 Jan.
“BCS-BEC crossover in a superﬂuid Fermi gas”
43) Dr. Yasuyuki Akiba (RIKEN Nishina Center), 19
Mar.
“High Energy Heavy Ion Physics at RHIC”

Advanced Meson Science Laboratory- 384 -

1) Dr. Kozi Nakai (KEK, JAPAN), 19 Apr.
“Development of SCITIC (Scintillation Track Im-

age Camera) and measurement of spin-orbit interaction in hyperon-nuclear scattering”
2) Dr. Daisuke Kamei (Applied Nuclear Physics
Laboratory, RIKEN, JAPAN), 24 May“Introduction of the beta-NMR method and theapplication to a study of nuclear structure for unstable nuclei”
3) Dr. Takashi Taniguchi (KEK, JAPAN), 31 May“Development of front-end electronics for gas
chambers with high speed bi-polar ASIC at KEK”
4) Dr. Hazuki Furukawa (Ochanomizu University,
JAPAN), 8 Jun.
“Weakferromagnetic Superconductor ErNi2B2C
and a possibility of the spontaneous vortex phase”
5) Dr. Noriyoshi Ishii (University of Tokyo,
JAPAN), 14 Jun.
“5 quark picture of Lambda(1405) fromanisotropic lattice QCD”
6) Dr. Norimichi Kojima (University of Tokyo), 19
Jun.
“Study on the ferromagnetism and the dynamical
spin-crossover phenomenon coupled with spin andcharge for iron mixed-valence complexes, A[FeIIFeIII(dti)3](dto=C2O2S2)”

12) Dr. Takahisa Koike (Advanced Meson Science
Laboratory, RIKEN, JAPAN), 15 Nov.
“DWIA calculation of in-ﬂight (K−,n) reaction
spectra using helium 3 target”
13) Dr. Youichi Ikeda (Osaka University, JAPAN), 15
Nov.
“Study of strange dibaryon in the KNN-πΣN coupled channel equation”
14) Dr. Takayuki Kawamata (Advanced Meson Science Laboratory, RIKEN, JAPAN), 23 Jan.
“Thermal conductivity and spin state in lowdimensional quantum spin systems”
15) Dr. Yoshio Yamaguchi (Theoretical Physics Laboratory, RIKEN, JAPAN), 8 Feb.
“Genesys of Meson Physics”
16) Dr. Hikomitsu Kikuchi (University of Fukui,JAPAN), 29 Mar.
“Observation of magnetization plateau in diamond chain compound”

Theoretical Physics Laboratory

7) Dr. Hideto En’yo (Radiation Laboratory, RIKEN,
JAPAN), 26 Jul.
“Mesons in Nucleus, seen in their e+e− decays”
8) Dr. Tatsuya Chujyo (University of Tsukuba,
JAPAN), 13 Sep.
“The multigap resistive plate chamber (MRPC)
as a new generation time-of-ﬂight detector”
9) Dr. Kenichi Hachitani (Chiba University,
JAPAN), 4 Oct.
“Possibility of Multipole Order in Filled Skutterudite SmRu4P12 ∼µSR and 31P-NMR
study∼”
10) Dr. Petros Aslanyan (JINR, RUSSIA), 6 Oct.
“The review of recent results for observation ofStrangeness = +1, 0, −1, −2 exotic states with
Lambda-hyperons and Ks0-mesons systems in p
+ propane collisionsat momentum 10 GeV/c”
11) Dr. Yasuyuki Ishii (Condensed Molecular Materials Laboratory, RIKEN, JAPAN), 30 Oct.
“High pressure experimental method for precise
magnetic and transportproperty measurements oforganic conductors”- 385 -

1) Dr. Yasuhiro Abe (City College of New York
(USA)), 19 May“Construction of fuzzy S4 and its applications”
2) Dr. Yoshio Kikukawa (University of Tokyo(Japan)), 30 May“Electroweak theory on the lattice with exact
gauge invariance”
3) Dr. Asato Tsuchiya (Osaka University (Japan)),
9 Jun.
“Bubbling AdS, N = 4 SYM on RxS3 and theories
with 16 supercharges”
4) Dr. Satoshi Iso (KEK (Japan)), 16 Jun.
“Hawking radiation and Anomalies”
5) Dr. Taku Izubuchi (Kanazawa(Japan)), 7 Jul.
“Lattice QCD and QED”

University6) Dr. Toshio Nakatsu (Osaka University (Japan)),
8 Jul.
“Amoebas and Instantons”
7) Dr. Yoshitake Hashimoto (Osaka City University(Japan)), 8 Jul.
“Introduction to tropical geometry”
8) Dr. Toshiaki Maeno (Kyoto University (Japan)),
8 Jul.

“Amoebas and their ultradiscretization”

Z 2 parity and Position/Momentum Propagator”

9) Dr. Yutaka Sakamura (Osaka University(Japan)), 14 Jul.
“Scherk-Schwarz twist in 5D conformal supergravity”
10) Dr. Nobuhito Maru (University of Roma and
INFN (Italy)), 21 Jul.
“Two-loop Calculation of Higgs Mass in GaugeHiggs Uniﬁcation”
11) Dr. Takao Suyama (Kyoto University (Japan)),
25 Jul.
“CFT for Closed String Tachyon Condensation”
12) Dr. Yutaka Hosotani (Osaka University (Japan)),
28 Jul.
“Dynamical Gauge-Higgs Uniﬁcation and LHC
Physics”
13) Dr. Amihay Hanany (MIT (USA)), 11 Aug.
“Tilings, Dimers, and Quiver Gauge Theories”
14) Dr. Giacomo Marmorini (Scuola Normale Superiore and INFN (Italy)), 25 Aug.
“Non-abelian vortices of higher winding number”
15) Dr. Akinori Kawachi (Tokyo Institute of Technology (Japan)), 1 Sep.
“Introduction to Quantum Computation”
16) Dr. Hirofumi Kubo (Kyushu University (Japan)),
6 Oct.
“Determining the power counting for nuclear
EFT from Wilsonian Renormalizatin Group”
17) Dr. Shin Nakamura (Hanyang University (Korea)), 11 Oct.
“A Holographic Dual of RHIC Hydrodynamics”
18) Dr. Ho-Ung Yee (Korea Institute for Advanced
Study (Korea)), 16 Oct.
“AdS/CFT with Tri-Sasakian Manifolds”
19) Dr. Nobuyasu Ito (University of Tokyo (Japan)),
20 Oct.
“Simulation study of transport phenomena”
20) Dr. Hoang Ngoc Long (Hanoi Institute of Physics(Vietnam)), 24 Nov.
“Neutrino mass and phenomenology of the economical 3-3-1 model”
21) Dr. Shoichi Ichinose (University of Shizuoka(Japan)), 27 Nov.
“Quantization of Fields in 5D Space-Time with

22) Dr. Kazuhiro Sakai (Keio University (Japan)), 1
Dec.
“Integrability in AdS/CFT Correspondence”
23) Dr. Yasuhiro Sekino (Okayama Institute forQuantum Physics (Japan)), 22 Dec.
“A Holographic Framework for Eternal Inﬂation”
24) Dr. Yutaka Okochi (California Institute of Technology (USA)), 19 Jan.
“Meta-stable vacua in supersymmetric gauge theories”
25) Dr. Yosuke Imamura (University of Tokyo(Japan)), 26 Jan.
“Anomalies in brane tilings”
26) Dr. Yoshiharu Kawamura (Shinshu University(Japan)), 27 Jan.
“Past and Future of Orbifold GUT – Towards
Three Generation Model”
27) Dr. Yutaka Hosotani (Osaka University (Japan)),
27 Jan.
“Gauge Higgs Uniﬁcation Models in Warped
Space”
28) Dr. Tetsuya Shiromizu (Tokyo Institute of Technology (Japan)), 27 Jan.
“Possible Problems of Randall-Sundrum Gravity
Theory”
29) Dr. Kei-Ichi Kondo (Chiba University (Japan)),
9 Feb.
“Mass gap and quark conﬁnement from YangMills theory to Faddeev model”
30) Dr. Toshihiro Matsuo (National Taiwan Normal
University (Taiwan)), 16 Feb.
“Finite Temperature String in AdS3”31) Dr. Poul H. Damgaard (Niels Bohr Institute(Denmark)), 23 Feb.
“Random Matrix Theory and low-energy constants of QCD”
32) Dr. Hidenori Sonoda (Kobe University (Japan)),
26 Feb.
“Application of the exact renormalization groupto perturbation theory”
33) Dr. Kiyoshi Higashijima (Osaka University(Japan)), 2 Mar.
“Renormalizable Nonlinear Sigma Models inThree Dimensions”- 386 -

Accelerator Applications Research Group
1) Dr. Reinhard Neumann (GSI (Germany)), 16
Mar.
“Materials research at GSI: Recent results on
nanowires, ion irradiation at high pressure, andbio-experiments with heavy-ion microprobe”

JUSTIPEN Seminar
1) Prof. B. A. Brown (Michigan State Univ., USA),
17 Aug.
“New sd-shell Hamiltonians’ ”
2) Prof. C. Bertulani (Arizona Univ., USA), 1 Nov.
“New Directions in Nucl. Astrophysics”
3) Prof. Peter Moller (LANL), 11 Dec.
“New Calculations of Nucl. Structure Properties
for Simulatin Data Bases with Focus on eﬀects oftriaxial Nuclear Shapes”
4) Dr. Yang Sun (Department of Physics and Joint
Insitute for Nuclear Astrophycis, Univ. of Notre
Dame, USA), 21 Dec.
“Projedcted Shell Model for Heavy Nuclei and
Nucl. Astrophysics”- 387 -AUTHOR INDEX阿部知子

ABE Tomoko

202, 251, 252, 253, 254, 255,

BENNETT Robert

76, 8993, 94

256, 257, 258, 259, 260, 261

BENTZ Wolfgang

ABU-IBRAHIM Badawy

49

BERG Georg

足立匡

ADACHI Tadashi

217, 218, 219, 220

155, 156BISHOP Shawn

ii, 17, 25

AIBA Keisuke

相葉恵介

215

BLUM Thomas

95

AIBA Takeshi

相場20

BOBREK Miljko

182, 183

AIDALA Christine

健78

BOYLE Kieran
藍原利光

AIHARA Toshimitsu

秋葉康之

AKIBA Yasuyuki

秋光

AKIMITSU Jun

純

ALIG Christian
ANDO Tomoko
ANDO Yoshiaki
AOI Nori

青井

BUNCE Gerry

177, 178, 179, 180, 181,

CHEN Alan

182, 183, 186, 187, 190,

CHOLLET Simon

168, 169, 170, 176, 177, 182, 183

191

CHU Chong-Sun

108

221

CIANCIOLO Vince
241

CLOET Ian

168, 169, 182, 183

93, 94

CLONTS Lloyd17, 21

182, 183

7, 86, 87, 88

15182, 183

D’ADDA Alessandro
DAM Binh

15, 28, 29, 33, 34

107

大樂誠司

DAIRAKU Seishi
245

DAVID Gabor

安藤嘉章

14

73

DAWSON Christopher

102

ii, 5, 8, 9, 10, 11, 14, 19, 20, 21, 23,

DEMICHI Kimihiko

出道仁彦

24, 25, 26, 27, 31, 32

DESHPANDE Abhay

青木和也
青木慎也

183

101, 103

DEWALD Alfred

6

青木孝道

126, 127

DHAWAN Satish

7, 87, 88

AOKI Yasumichi

青木保道

102

DINH DANG Nguyen

青山龍美

ARAI Ichiro

新井一郎
有馬朗人

ARIMA Akito

ARIYOSHI Kingo

耕一郎

浅井圭介

ASAI Keisuke

ATOMSSA Ermias

DRAPIER Oliver

168, 169, 170, 176, 177, 182, 183

167

DREES Axeliii, 12, 13, 34, 145, 146,DREES Manuel167, 203DZHORDZHADZE Vasiliy

168, 169, 170
112
91

EATON Gordon

EBISUZAKI Toshikazu

181, 186, 187, 188, 189, 190,

EGAMI Tomoaki

江上智明

191

ELEKES Zoltán7, 8, 9, 11, 14, 17

205, 206

ELLINGHAUS Frank

168, 169, 170, 176, 177, 182, 183
69, 70, 74
馬場秀忠

40
戎崎俊一

193, 194, 195, 196

43

77

EMOTO Takashi

江本 隆

35, 36, 162

ENDO Natsumi

遠藤奈津美

26, 27ii, 5, 10, 11, 14, 20, 21, 23,

ENOKI Toshiaki

榎233

25, 30, 31, 32, 193, 194,

ENOMOTO Masaya

榎本真哉

v

ENOMOTO Shuichi

榎本秀一

245, 246, 247, 248

195, 196

EN’YO Hideto

101

敏明

延與秀人

iv, 65, 66, 168, 169, 170, 171,172, 176, 177, 178, 179, 180,

238

BAZILEVSKY Alexander95

11, 17

175, 176, 177, 178, 179, 180,

BABA Hidetada

BAKULE Pavel土井琢身

DOMBRÁDI Zsolt

168, 169, 170, 171, 172, 174,

AVERBECK Ralf

BAER Oliver57, 58, 59

69, 70, 74, 168, 169

DOI Takumi

61

浅井淳吉

ASAI Junkichi

DION Alaniii, 12, 13, 34, 167

有吉欽吾
旭ASAHI Koichiro

110, 113

82, 148, 149

新井崇雅

ARAI Takamasa

11, 1479, 80, 81, 84, 168, 169, 173, 182,

79, 84AOKI Takamichi
AOYAMA Tatsumi

84

33

安藤智子
考

AOKI Kazuya
AOKI Sinya

BRITTON Charles

112

AMADIO Guilherme

7, 87, 88

169, 170, 171, 172, 176,

7, 87, 88

ALEXEY Korsheninnikov

78, 79, 80, 81, 84, 168, 169

BRAVAR Alessandro

69, 70, 71, 74, 75, 92, 168,

秋山隆宏

AKIYAMA Takahiro
ALEKSEEV Igor

117, 265, 266

181, 186, 187, 197, 198

79, 80, 81-i-ETO Minoru

衛藤 稔

EYSER Kjeld

7, 86, 87, 88
111

FINGER Miroslav

170

FÜLÖP Zsolt

五味朋子

GOMI Tomoko

後藤

彰

淵

15

FUJIKAKE Kotaro

藤掛浩太郎

212, 213藤川尚志

15, 28, 29

GOTO Takayuki

FUJIMAKI Masaki

藤巻正樹

120, 121, 122, 123, 131,

後藤

GOTO Yuji

GOTO Ken

6, 82, 117, 118, 119,

健

231

後藤貴行

後藤雄二

170, 197, 198

267, 268
藤縄

藤田 新

雅

222, 223, 224

75, 79, 84, 89, 90, 92, 168, 169,

132, 135, 136, 265, 266,

FUJITA Shin

口絵 1

265, 266, 267, 268

FUJIKAWA Hisashi

GRANIER DE CASSAGNAC Raphael

176, 177, 182,

269, 270

183

168, 169, 170, 171, 172,

GROSSE-PERDEKAMP Matthias

176, 177, 178, 179, 180,

GUILLAUME Pedoussaut

181, 182, 183, 186, 187

GUNJI Taku

HABA Hiromitsu

FUKAO Yoshinori

深尾祥紀

80, 81FUKAYA Hidenori

深谷英則

103, 106

郡司

卓

243

羽場宏光

38, 117, 204, 241, 242, 243,
248

深澤英人

229, 230

HACHITANI Kenichi

FUKUCHI Tomonori

福地知則

6, 19, 32, 193, 194,

HAEBERLI Willy

7, 87, 88

195, 196

HAGINO Kouichi

萩野浩一

FUKUDA Mitsunori

福田光順

20

HAMADA Tsuyoshi

濱田

HAMAGAKI Hideki

浜垣秀樹

福田直樹

口絵 1

7, 口絵 1 8, 14, 26

27
福井利晃

FUKUI Toshiaki

福澤聖児

FUKUZAWA Seiji
FULOP Zsolt

ii, 5, 6, 19

福嶋健二

FUKUSHIMA Kenji

古田 黄

FURUTA Ko

武古立直也

FURUTACHI Naoya

159, 160

花田政範

127, 128, 129, 130,

HANS Schuessler

166

135, 136, 137, 148,

HANZAWA Eiko

半澤栄子

149, 250, 252, 253,

HARA Mitsuo

原 光雄

254, 255, 256, 257,

HASEBE Hiroo

長谷部裕雄

137
109

254

38
128, 129, 130, 138

258, 259, 260, 261,

HASEGAWA Hirokazu

長谷川浩一

11, 14265, 266, 267, 268

HASEYAMA Tomohito

長谷山智仁

口絵 1

7,

口絵 1

8, iii

橋本省二

HASHIMOTO Shoji

103

橋本佳子

ii, 5, 17, 24, 26, 27

225

HASHIMOTO Yukio

橋本幸男

56

212, 213

HASHIZUME Yuhei

橋爪祐平

20

35, 162

HASUKO Kazumi

蓮子和巳

85

16

HATAKEYAMA Atsushi

畠山108, 109HATAKEYAMA Naoto

畠山直人

二上宇内

14

温

早川一生

HAYAKAWA Kazuo

GASTALDI Franck

168, 169, 170, 176, 177, 182, 183

HAYAKAWA Masashi

GELBERG Adrian

19

HAYAKAWA Seiya

GELIS Francois

96

HAYASHI Katsuro

GIBELIN Julien

11, 17

HAYASHI Yoriko

林 克郎
林 依子

12, 34

203

早川雅司

早川勢也

212, 213

95, 104, 105, 106, 113

33, 34232
252, 253, 254, 255, 257,
258, 259, 260, 261

GILL Ronald

7, 87, 88

GOKA Tateo

五家建夫

GOLOVKOV Mikhail

70, 71, 73, 197, 198

96

古川幸弘

FURUKAWA Yukihiro

193, 194, 195, 196

濱仲 誠

HAMANAKA Makoto

HASHIMOTO Yoshiko
古川

62

浜垣 学

HANADA Masanori

267, 268

古林孝夫

FURUKAWA Takeshi

229, 230

剛

15, 82, 122, 123, 126,

8, 9

FURUBAYASHI Takao

FUTAKAMI Udai

蜂谷健一

HAMAGAKI Manabu

福西暢尚

FUKUNISHI Nobuhisa

85

71

FUKAZAWA Hideto

FUKUDA Naoki

168, 169, 170,

82, 139, 148, 149

藤原康平

FUJIWARA Kohei

3, 口絵 1 4, 口絵 1 5,

130, 131, 132, 137, 148, 149,

好秀

FUJINAWA Tadashi

33

口絵 1

124, 125, 126, 127, 128, 129,21

11, 14, 17

FUCHI Yoshihide

11, 14, 17, 25, 26, 27

郷農靖之

GONO Yasuyuki
GOTO Akira

FERRETTI Luca

FOMICHEV Andrey

111

152

建軍

15, 28, 29

HIGASHITANI Atsushi

東谷篤志

HE Jianjun

21- ii -

何

254

東山幸司

HIGASHIYAMA Koji

55

日暮（蛭沼）利江子

HIGURASHI Rieko

日暮祥英

HIGURASHI Yoshihide

269, 270

14, 117, 118, 119,265, 266, 267, 268

HIRANO Masahiro

平野正浩

232

HIROTA Katsuya

広田克也

193, 194, 195, 196

HJORTH-JENSEN Morten
HONDA Zentaroiii, 12, 13, 34, 167

ISERI Yasunori

井芹康統

43

ISHIDA Katsuhiko

石田勝彦

39, 40, 41

ISHIDA Yoshihisa

石田佳久

37, 147, 150, 151, 166

石井建一

ISHII Ken’ichi

52

35, 36, 162

石川和宏

ISHIKAWA Kazuhiro
ISHIKAWA Kenichi

石川健一

103

ISHIMOTO Shigeru

石元 茂

22, 161

堀

51, 52

ITO Keisuke

伊藤圭介

24

堀端孝俊

56

ITO Makoto

伊藤44, 47202

堀米敦子

269, 270

ITO Sachiko堀内

48, 49ITO Tatsuhiro

渉

星野正光

HOSONO Hideo

細野秀雄

HUANG Haixin

7, 87, 88

伊藤祥子

市田裕之

ICHIHARA Takashi

市原

212, 213

ITO Tetsuaki

伊藤哲明

226

IWAI Yoshio

岩井良夫

209, 210, 211

252, 254, 257, 258, 261

IWAKI Masaya

209, 210

岩城一考

卓

18, 165, 197, 198, 199

岩木正哉

24

IWAO Yoshihiko

ICHIKAWA Takatoshi

市川隆敏

62

IWASAKI Hironori

市川雄一

260
251

岩本 昭

IWAMOTO Akira

市川雅浩

岩尾快彦

岩崎弘典
岩崎雅彦

IWASAKI Masahiko

岩佐直仁

8, 9, 10, 14, 15, 17, 20, 25,

181, 182, 183, 186, 187, 188,

IWASE Akihiro

岩瀬彰宏

202

189, 190, 191

IZUBUCHI Taku

出渕

95

29

ii, 6, 19, 30, 31, 32, 155,

IIDA Kei

ii, 5, 14, 23

五十嵐明則
五十嵐香織

飯田 圭

和泉

真

泉

雅子

141, 142, 143

JINNOUCHI Osamu

陣内 修

7, 87, 88

門野良典

221

JOSEPH Seele

77

KADONO Ryosuke
KAGAMI Souta

257

各務惣太

池田清美

i, 50

KAGEYAMA Tadashi

IKEDA Naomi

池田直美

201

KAJI Daiya

IKEDA Tokihiro

池田時浩

133, 134, 209, 210

KAJIHARA Fukutaro

池戸 豊

167, 232, 263

KAJI Ryousuke

137, 138

IKEZAWA Eiji

池沢英二

265, 266, 267, 268

正

梶原福太郎
角山智子

KAKUYAMA Tomoko

今井憲一

84

KAMBARA Tadashi

神原

今井伸明

ii, 5, 11, 14, 17, 25

KAMEDA Daisuke

亀田大輔

IMAO Hiroshi

今尾浩士

39, 40201, 265, 266

INAFUKU Kiyohiko

稲福清彦

8, 9, 15, 20, 29

INAMURA Takashi

稲村 卓

38

INOUE Takayuki

井上貴之

236

17

IMAI Ken’ichi

稲辺尚人

69, 70, 74

226

IMAI Nobuaki
INABE Naohito

265, 266, 267, 268

241, 242

鍛治亮祐

KALINKA Gábor

12, 34影山

加治大哉

IKEDO Yutaka

池上九三男

249, 250

JAMESON Robert

IKEDA Kiyomi

IKEGAMI Kumio

238

215

166

伊地知実利

IJICHI Sanetoshi

IZUMI Makoto
IZUMI Masako

20, 22

246, 247

60

飯村秀紀

IIMURA Hideki

卓

泉川卓司

IZUMIKAWA Takuji

156
IGARASHI Akinori

41

IWASA Naohito

168, 169, 170, 171, 172, 174,

井手口栄治

IGARASHI Kaoriii, 5, 6, 10, 11, 14, 17, 19,
24, 25, 31, 32

175, 176, 177, 178, 179, 180,

家城和夫

62
18, 165

6, 8, 9, 19, 23, 24, 25, 31,
32

亮

35, 36, 162

232

ICHIKAWA Masahiro

一宮

24, 165

伊藤龍浩

IWAKI Kazunari

ICHIDA Hiroyuki

誠

伊藤正俊

ITO Masatoshi

HORIGOME Atsuko

ICHIKAWA Yuichi

73

76

史説

HOSHINO Masamitsu

磯部忠昭

ISOBE Tadaaki

洞口琢磨

HORIUCHI Wataru

IEKI Kazuo

14

251

HORIBATA Takatoshi

IDEGUCHI Eiji

iii, 11, 14, 23, 26, 27

228

本間道雄

ICHIMIYA Ryo

石原正泰

ISHIHARA Masayasu

本間正充

HORAGUCHI Takuma
HORI Fuminobu

井上壮志

本多善太郎

HONMA Masamitsu
HONMA Michio

INOUE Takeshi

正37, 202, 209, 210iii, 12, 13, 34, 167

KAMETANI Soichiro

亀谷聡一朗

197, 198

KAMETANI Soichiro

亀谷聡一郎

90

KAMIGAITO Osamu

上垣外修一

124, 125, 126, 127,
265, 266, 267, 268

252

KAMIMURA Masayasu- iii -

上村正康

43

神谷厚志

KAMIYA Atsushi

263
延與佳子

KANADA-EN’YO Yoshiko

木田紀行

KIDA Noriyuki
46

KANADA Keishi

金田圭史

224

KANAI Yasuyuki

金井保之

37, 147, 209, 210, 211

v

木寺正憲

KIDERA Masanori

117, 118, 119, 265, 266,
267, 268

木島 剛

KIJIMA Gou

iii

KANAMORI Issaku

金森逸作

106, 107

KIKKAWA Akiko

KANAYA Kazuyuki

金谷和至

103

KIKUCHI Daisuke

菊池大輔

204

KIKUCHI Takashi

菊池崇志

82, 148, 149

金山洋介

KANAYAMA Yousuke

金谷健至

KANAYA Takeshi

神波千秋

KANBA Chiaki

245, 246, 247

260

吉川明子

菊永英寿

KIKUNAGA Hidetoshi

253

KIM Aram

228

38, 241, 242

33

KANEKO Takashi

金児隆志

103

KIM Jang Youl

KANESUE Takeshi

金末 猛

141, 142, 143, 214

KIMURA Hitomi

金 壯

木村仁美

23

15

KANNO Shouko

菅野祥子

ii, 5, 10, 11, 14

KIMURA Kazuie

木村一宇

205, 206

KANO Hiroyuki

狩野博之

168, 169, 170, 176, 177, 182,

KIMURA Masaaki

木村真明

16

183, 186, 187
KARMANOV Dmitri

91
笠松良崇

KASAMATSU Yoshitaka
加瀬昌之

KASE Masayuki

加藤宏和

KATO Hirokazu

博

木村修一

245, 246, 247

木村祐介

109

木下東一郎

KINOSHITA Toichiro

岸田 隆

117, 120, 121, 122, 123, 126,KISHIDA Takashi

127, 128, 129, 130, 131, 132,

KISTENEV Edouard

91

133, 134, 135, 136, 137, 138,

KITAMOTO Yusuke

北本優介

北野

201, 205, 206, 265, 266, 267,

KITANO Masaru

268

KITAYAMA Mitsuhisa

片山一郎

KATAYAMA Ichiro

38

KIMURA Shuichi
KIMURA Yusuke

147

113

11, 19

大

248

139

來山益久

26, 27
小林-込山美咲

KOBAYASHI-KOMIYAMA Misaki

244

120,
121,

KATO Hiroshi

加藤

152

265,

KATO Kiyoshi

加藤幾芳

i

266,

KATO Mineo

加藤岑生

40

267,

KATO Seigo

加藤清吾

15

268

KATSUMATA Koichi

勝又紘一

228

KOBAYASHI Kei

KAWABATA Takahiro

川畑貴裕

24, 153, 154, 155,

KOBAYASHI Kiyoshi

小林 圭

小林清志

267, 268

156, 157, 158, 159,

KOBAYASHI Tohru

小林 徹

212, 213160

KOBAYASHI Tomohiro

20, 22小林知洋

271

KAWAGUCHI Takeo

川口武男

133, 134

KOBAYASHI Toshio

小林俊雄

18, 23, 26, 27, 165

KAWAHARA Tomomi

河原朋美

24, 163, 164

KOBAYASHI Yoshio

小林義男

iii, 13, 34, 203, 204,

KAWAI Hikaru

川合

KAWAI Shoko

河合祥子

光

109, 110

236, 243, 244

11, 25, 26, 27

KODA Akihiro

幸田章宏

236

小平治郎

114

KAWAMOTO Noboru

河本 昇

107

KODAIRA Jiro

KAWAMURA Hirokazu

川村広和iii, 34, 145, 146, 167

KOHAMA Akihisa

小濱洋央

49, 60

KAWAMURA Hiroyuki

川村浩之

114

KOHARA Shigeo

小原重夫

265, 266, 267, 268

河村成肇

39, 40

KAWAMURA Naritoshi

河野重行

KAWANO Shigeyuki

川崎健夫

KAWASAKI Takeo
KAWASAKI Yoshiya

KAWASHIMA Motohiro

川嶋基敬

191

KOMATSUBARA Tetsurou

KAWASUMI Masaya

川角昌弥

263

15, 28, 29

253, 257, 258, 259

258

小島憲道

KOJIMA Takao

小島隆夫

KOMIYAMA Tatsuto

207, 208

217, 218, 219, 220

小泉綾子

KOJIMA Norimichi

225

KHIEM Le Hong小池洋二

KOIZUMI Ayako

175, 188, 189, 190,
川嶋祐介

風間裕介

229, 230

168, 169, 170, 174,

KAWASHIMA Yusuke
KAZAMA Yusuke

KOIKE Yoji

193, 194, 195, 196

洋

小池茂年

KOIKE Shigetoshi

170, 186, 187

川崎賀也

小堀

KOHORI Yoh

258v

37, 147, 209, 210
小松原哲郎

込山立人

KOMURO Mari

小室麻里

20

KONDO Yosuke

近藤洋介

ii, 5, 14, 17, 20, 21, 23, 25,
26, 27- iv -

188, 189

152

KONDRASHEV Sergei

141, 142, 143, 214

小西憲一

KONISHI Kenichi

小高康照

KOTAKA Yasuteru
KOYAMA Ryo小山KRUPKO Sergei

21

亮

前田修大

MAEDA Nobuhiro
205, 206

前田幸重

MAEDA Yukie

122, 123, 131, 132, 267,

MAEGAWA Satoru

268

MAIE Takeshi

122, 123, 131, 132, 265, 266

MAKDISI Yousef

236, 243, 244

MAO Yajun

前川

覚

7, 87, 88

90

24

MARMORINI Giacomo

KUBONO Shigeru

久保野

10, 14, 15, 28, 29, 33,

MARTEL Ismael

21

34, 155, 156

MASUDA Hideki

益田秀樹

久保敏幸

工藤久昭

MASUDA Kunikazu

益田邦和

267, 268

MATSUDA Yasushi

松田

259

40

KUNIBU Makoto

國分 誠

14

栗林隆宏

栗田和好

KURITA Kazuyoshi

KUROIWA Sogo

黒岩壮吾

松田洋平

MATSUDA Yohei

242, 248

39, 40, 41, 232, 238

18, 26, 27, 161, 165

松古栄夫

MATSUFURU Hideo

工藤勝久

靖

松田恭幸

MATSUDA Yasuyuki

201

242

KUDO Katsuhisa

KURIBAYASHI Takahiro

211

11, 14, 20, 31, 32, 37, 147,
153, 154, 155, 156
KUDO Hisaaki

111

口絵 1 7, 口絵 1 8, ii, 5,

久保山智司

KUBOYAMA Satoshi

226

168, 169, 170, 176, 177, 182, 183

久保木浩功

KUBO Toshiyuki

202

126, 127, 137, 138

KUBOKI Hironori

茂

63

24

真家武士

MANNEL Eric

久保謙哉

KUBO Kenya

111

越水正典

KOSHIMIZU Masanori

間所秀樹

MADOKORO Hideki

103

MATSUI Nobuyuki

松井信行

17, 26, 27

MATSUISHI Satoru

松石 聡

232

松本晴久

MATSUMOTO Haruhisa

松本 淳ii, 5, 8, 9, 10, 11, 14, 17,

MATSUMOTO Jun

35, 36, 162, 168, 169,

MATSUMOTO Takuma

170, 174, 175, 188, 189,

MATSUO Keiji

松尾啓司

242, 248

190, 191

MATSUO Ryou

松尾 亮

24

MATSUO Yukari

松尾由賀利

221

231

松本琢磨

黒川明子

8, 9, 10, 17, 20, 21, 31,
32, 193, 194, 195, 196

MATSUYAMA Yuuichi

松山裕一

KUROKI Tsunehide

黒木経秀

110

MATSUZAKI Teiichiro

松崎禎市郎

KUROSAWA Maki

黒澤真城

168, 169, 170, 171, 172,

MCLERRAN Larry

176, 177, 178, 179, 180,

MERKIN Michael

181

MICHIMASA Shin’ichiro

日下健祐

桑島淳宏

KUWAJIMA Atsuhiro
KUZMIN Evgueni

口絵 1

43

212, 213

KUROKAWA Meiko

KUSAKA Kensuke

152

松山貴史

MATSUYAMA Takahumi

20
11, 1439, 40, 41, 225, 228

96
91
道正新一郎

7, 口絵 1 8, ii

20, 31, 32

35, 36, 162

峯村俊行

MINEMURA Toshiyuki

21
15, 29MITTIG Wolfgang

21

LANGOUCHE Guido

203

MIURA Notooki

三浦元隆

LEBEDEV Alexander

168, 169

MIWA Koji

三輪浩司

ii, 5, 10, 11, 14

三頭聰明

MITSUGASHIRA Toshiaki

KWON Young Kwan

68

15, 28MIYAKE Yasuhiro

三宅康博

232, 238

LEE Ju Hahn

15

MIYAMOTO Yuki

宮本祐貴

170

宮野健次郎

238

宮坂 等

227

LE Khiem

22

MIYANO Kenjiro

LIAN G.

28

MIYASAKA Hitoshi

宮崎

MIYAZAKI Jun

108

淳

244

LIOUBIMOV Vladimir147, 166

MIYAZAKI Kiyoshi

宮崎 潔

260

LITVINENKO Anatoliy

91

MIYAZAWA Yutaka

宮沢

255

MIZUSAKI Takahiro

水崎高浩

LIU Han83

LIU Ming

83

LIU Minliang

MOCSY Agnes
6, 19, 30, 31, 32

文俊永

15, 28

森本幸司

241

28

MORIMOTO Kouji

28, 91, 168, 169

MORISHITA Toshikazu
8, 9, 23

MORITA Kosuke-v-

51, 5297

LI Zheng

町田智大

豊

MOON Jun Young

LIU W.P.

MACHIDA Tomohiro

38, 24214LEE Chun Sik

LIN Feng-Li

8, 9, 10, 11, 14,

森下敏和

森田浩介

255

241, 242

MORREALE Astrid

78

MOTIZUKI Yuko

望月優子

向井弘樹

MUKAI Hiroki

63

NARITA Keigo

本林 透

MOTOBAYASHI Tohru

向MUKAI Kazuhiko

南日

卓

成田圭吾

167

NANNICHI Takashi
口絵 1

7,

NARUKI Megumi

口絵 1

8, ii, 5, 8, 9,

NARUSAWA Tadashi
NASS Alexander21, 23, 25, 26, 27,

NEBIKI Takuya

根引拓也

193, 194, 195, 196

NGUYEN Khai

22

167, 263

168, 169NIIKURA Megumi

新倉 潤

21

村上浩之

14

村上哲也

165

NIKOLSKII Evgenii

MURAKAMI Youichi

村上洋一

238

NIKOLSKII Yuri

MUTO Ryotaro

武藤亮太郎

MYO Takayuki

明 孝之

113

西田 稔

259

NISHIDA Minoru

iv, 65, 66, 168, 169, 170,

NISHIHARA Kiyoshi

i

長江大輔

17

仁尾真紀子

NIO Makiko

171, 172, 178, 179
NAGAE Daisukeii, 6, 19, 21, 28, 29, 30,
31, 32

iii, 34, 145, 146, 167

村田達郎

MURATA Tatsuro

135, 136, 267, 268

西原

潔

258

NISHIMURA Mizuki

西村美月

28

NISHIMURA Shunji

西村俊二

19, 21, 25, 28, 29, 33

西山樟生

232, 236

iii, 12, 13, 34, 145, 146,NISHIYAMA Kusuo

167, 203

NISHIO Hidekazu

西尾和之

211

NAGAMINE Kanetada

永嶺謙忠

39, 40, 41

NITTA Muneto

新田宗土

111

NAGASAKI Yoshifumi

長崎欣史

234

NOAKI Junichi

野秋淳一

102

長瀬

NAGASE Makoto

NOBUHISA Fukunishi

福西暢尚

268

NODA Koji

野田耕司

37, 147

107

永田正一

225

長友

傑

NAGATOMO Takashi

NAKABAYASHI Takumi

中井陽一

野谷将広

168, 169, 182, 183
野崎 洋

12, 13, 34, 167

NOZAKI Hiroshi

ii, 5, 8, 9, 20, 26,

NOZUE Yasuo

27

O’BRIEN Edward

格7, 86, 87, 88, 91

ODAHARA Atsuko

野末泰夫

8, 9, 10, 11, 14
263

231

91
小田原厚子

28

小田島仁司

213

117, 118, 119, 265,

ODASHIMA Hitoshi

266, 267, 268

OGATA Kazuyuki

緒方一介

43

OGATA Koremitsu

緒方惟光

22

37, 211

中島真平

NAKAJIMA Shinpei

NOTANI Masahiro

彩

中川孝秀

NAKAGAWA Takahide

20, 22

OGAWA Akio

小川暁生

85
103

NAKAMURA Masato

中村仁音

138

OGAWA Kenji

小川兼司

NAKAMURA Satoshi

中村

40

OGILVIE Craig

168, 169

NAKAMURA Takashi

中村貴志

37, 147, 166

OGIWARA Kiyoshi

荻原 清

NAKAMURA Takashi

中村隆司

ii, 5, 8, 9, 14, 17, 20,

OGLOBLIN Alexey

21

21, 23, 25, 26, 27

OHASHI Keisuke

大橋圭介

哲

131, 132NOUICER Rachid

中林中川NAKAGAWA Itaru

NAKAI Yoichi

120, 121, 265, 266, 267,

永田和広

NAGATA Kazuhiro
NAGATA Shoichi

誠209, 210

209, 210NGUYEN Matthew

MURAKAMI Hiroyuki

村田次郎

忠

7, 87, 88

MURAKAMI Tetsuya
MURATA Jiroiv, 65, 66

成沢

10, 11, 14, 17, 20,

269, 270

和彦

成木 恵

23

111

NAKAMURA Takeshi

仲村武志

267, 268

OHBU Sumie

NAKANISHI Kohsuke

中西康介

155, 156OHIRA-KAWAMURA Seiko

NAKANISHI Takashi

中西

38

OHIRA Hideharu

大平秀春

201

NAKANISHI Yukiko

中西由季子

245

OHKI Tomonori

大木智則

265, 266

孝

中野和城

NAKANO Kazuhiro

138

NAKANO Kenichi

中野健一

75, 92NAKANO Takehito

中野岳仁

231

NAKANO Taro
NAKAO Taro

中野太郎
中尾太郎

253
河村聖子

大西宏明

OHNISHI Hiroaki

221, 226, 227

168, 169, 170, 176, 177,
186, 187

25

OHNISHI Jun-ichi

大西純一

118, 119, 137

OHNISHI Tetsuya

大西哲哉

口絵 1

7, 口絵 1 8, 11,ii, 6, 17, 19, 24

22, 25, 31, 32, 82, 148,

中務

孝149, 161, 165

中山佳晃

23

NAKATSUKASA Takashi
NAKAYAMA Yoshiaki

大部澄江

207, 208, 271

47, 54OHNUMA Mio- vi -

大沼みお

252

大城幸光

OHSHIRO Yukimitsu

267, 268

OHTA Hirofumi

太田寛史

54

OHTAKE Masao

大竹政雄

口絵 1

182, 183

PERERA Aloy

大谷俊介

OHTANI Shunsuke

PEI Hua

7, 口絵 1 8

37, 147

17, 25PERESEDOV Valeriy

91

PETRECZKY Peter

97, 99OHTA Ryuichi

太田隆一

267, 268

PHAM Hung

OHTA Shigemi

太田滋生

98

PRATT Francis

大坪

隆

OHTSUKI Tsutomu

大槻

OHZUKU Tsutomu

OHTSUBO Takashi

22
231, 233, 239

20, 82, 148, 149

QUANG HUNG Nguyen

勤38

REIDLER Petra

170

小槻 勉

167

RISDIANA Risdi

217, 218, 219

59

OKADA Hiromi

岡田裕美

7, 86, 87, 88

ROBERT Scheuermann

OKADA kensuke

岡田謙介

76

ROUSSEL-CHOMAZ Patricia

37, 147, 166

RYUTO Hiromichi

岡田邦宏

OKADA Kunihiro

岡田卓也

OKADA Takuya

237
21

龍頭啓充

128, 129, 130, 202, 205,

204

206, 250, 252, 253, 254,

OKAMOTO Masataka

岡本昌高

103

255, 256, 257, 258, 259,

OKAMURA Hiroyuki

岡村弘之

24

260, 261, 265, 266, 267,

OKAMURA Masahiro

岡村昌宏

141, 142, 143, 214

大川正典

OKAWA Masanori

沖 直樹

OKI Naoki

ONG Hooi

156, 157, 158
SAITO Hajime

斉藤 肇ii, 5, 6, 8, 9, 17, 19, 25, 26,

SAITOH Ayumi

齋藤麻優美

27, 31, 32

SAITO Hiroyuki

斉藤宏之

小野寺秀也

大野木哲也

ONUKI Yoshiyuki

小貫良行

204

SAITO Jun

斉藤 準

107
84

168, 169, 170, 171, 172,

SAITO Takehiro

斎藤健浩

224

176, 177, 178, 179, 180,

SAKAGUCHI Harutaka
SAKAGUCHI Satoshi

坂口聡志

24, 163, 164

坂口貴男

73

大沢 明

222, 223, 224

SAKAI Hazuki

16

SAKAI Hideyuki

大島永康

酒井葉月

158

ii, 5, 10, 11, 14, 17, 25, 30, 31,

SAKAI Shingo

32, 193, 194, 195, 196

SAKAMOTO Hisao

OTA Yoshiho

太田嘉穂

212, 213

SAKAMOTO Naruhiko

大友洋光

坂井真吾

70, 74

坂本久雄

24, 124, 125, 126,
127, 265, 266, 267,

201

268
SAKASHITA Kohichi

大塚孝治

269, 270

坂本成彦

6, 8, 9, 18, 19, 21, 23, 26, 27,
165

坂下耕一

51, 52OYAMADA Kazuyuki

小山田和幸

265, 266

OYAMATSU Kazuhiro

親松和浩

60

OZAKI Mizue

尾崎瑞枝

245

OZAWA Akira

小沢

11, 20, 22, 82, 148, 149

顕

24, 153, 154, 155, 156, 157,

37

大田晋輔

OTSUKA Takaharu

11

酒井英行

OTA Shinsuke

大津秀暁

18, 165

SAKAGUCHI Takao

尾立晋祥

OTSU Hideaki

坂口治隆

242, 248

ORYU Shinsho

OTOMO Hiromitsu

227
253, 255, 256, 259, 260, 261

齊藤直人

OOSAWA Akira

OSHIMA Nagayasu

118, 119SAITO Naohito

103

181, 186, 187
大江一弘

242, 248

10, 11, 14, 15, 17, 28, 29, 155,

137, 138, 265, 266, 267, 268

ONOGI Tetsuya

OOE Kazuhiro

齋藤明登

SAITO Akito

ii, 6, 8, 9, 10, 11, 19, 25, 26, 27

大西健夫

ONODERA Hideya

ii, 5, 17, 26, 27

73

雑賀大輔

SAIKA Daisuke

奥村俊文

奥野広樹

王 恵仁

ONISHI Takeo

SAHLMUELLER Baldo

217, 219

OKUMURA Toshifumi
OKUNO Hiroki

268

103

168, 169, 170, 171,172, 174, 175, 178,
179, 188, 189, 190,
191

SAKUMA Fuminori

佐久間史典

iv, 65, 66

SAKURAGI Yukinori

櫻木千典

45

SAKURAI Hiroyoshi

櫻井博儀

口絵 1 7, 口絵 1 8, ii,

OZAWA Kyoichiro

小沢恭一郎

OZEKI Kazutaka

大関和貴

18, 161, 165

5, 6, 8, 9, 10, 11, 14,

OZONO Hironobu

大園浩之

201

17, 19, 20, 23, 26, 27,

PAK Robert

67, 70, 71

168, 16982, 148, 149

PANCAKE Charles

168, 169, 170, 176, 177, 180, 181

SANCHEZ-BENITEZ AngelPANCAKE Chuck

182, 183

SASAKI Yasutomo- vii -

21

佐々木康友

152

佐々木雄一朗

SASAKI Yuichirou

笹本良子

SASAMOTO Yoshiko

133, 134

SIDORCHUK Sergei

24, 155, 156, 157, 158,

SILVA Cesar

159, 160

SO Hiroto

21

71
宗

博人

SASANO Masaki

笹野匡紀

24

SOHLER Dóra

SATO Hideyuki

佐藤英行

204

SONDHEIM Walter

104

17, 28168, 169, 170

SATO Hiromi

佐藤広海

193, 194, 195, 196

SONI Amarjit

SATO Nozomi

佐藤 望

241

STEPHENSON Edward

SATO Tadashi

佐藤雅志

253, 254

佐藤義輝

SATOU Yoshiteru

佐藤 渉

SATO Wataru

佐藤洋平

SATO Yohei

SCHUESSLER Hans
SEELE Joseph
SEIDL Ralf

17, 18, 21, 23, 24, 26, 27

248

124, 125, 126, 127

STRASSER Patrick

41

147

115

須田健嗣

SUDA Kenji

84, 907, 87, 88

STINGELIN Lukas

STRATMANN Marco

201

24

SUDA Shinichi

須田紳一

iii

SUDA Toshimi

須田利美

18, 21, 22, 35, 36, 161, 162,
165

85

SEKIGUCHI Kimiko

関口仁子

SEKIMOTO Michiko

関本美知子

SEKINE Chihiro

関根ちひろ

SEKINE Yasuhiko

関根靖彦

SEMENOV Andrei

182, 183

SERATA Masaki

世良田真来

SETO Richard

24

菅井

勲

168, 169, 170, 190,

SUGAI Isao

191

SUGAWARA Hitoshi

40

159, 160
菅原

仁

204

菅原孝昌

204, 229, 230

SUGAWARA Takamasa

252

SUGAWARA Tousuke
SUGIMOTO Satoru

杉本

14

SUGIMOTO Takashi

杉本 崇

聡

22
50
12, 13, 14, 23, 26, 27,
34, 145, 146, 167

SUGIYAMA Jun

183

SUGIYAMA Masao

柴田利明

170

澁佐雄一郎

SHIBUSA Yuuichirou

島田健司

SHIMADA Kenji

SUGO Ryohei
110

島村

215

勲

清水裕彦

193, 194, 195, 196

SHIMIZU Yoshifumi

清水良文

53

SHIMODA Tadashi

下田 正212, 213

下村浩一郎
下浦

享

32

232, 235, 237

SUZUKI Hiroyuki

鈴木博之

225

SUZUKI Kenichi

鈴木賢一

260

鈴木都文

SUZUKI Mikiko

鈴木美季子

203
ii, 5, 6, 17, 19, 25
245

156, 157, 158, 193, 194,SUZUKI Shoji

鈴木祥二

161

195, 196

SUZUKI Takao

鈴木栄男

v, 167, 217, 218, 222, 223,

篠原摩有子

224, 225, 228, 231, 235, 236,
38, 241, 242

篠原聡始

263

8, 9, 20, 23, 24, 26,

SUZUKI Takao

27

SUZUKI Takeshi

54

23

鈴木孝男

204, 229, 230

207, 208SUZUKI Yasuyuki

184, 185SUZUKI Youji

20, 22, 82, 148, 149

鈴木宜之

48, 49鈴木吉光

鈴木祥二

SVIRIDA Dimitry

38

22

7, 87, 88

TABARU Tsuguchika- viii -

233

鈴木 健

SUZUKI Yoshimitsu

城谷一民

104, 105, 106

31, 32, 153, 154, 155,

SHINOHARA Mayuko

庄司幸平

鈴木 博

鈴木 賢

20

宍戸統悦

SUZUKI Hiroshi

234
ii, 5, 6, 19, 20, 21, 25, 31,

SUZUKI Kunifumi

厚

SHIROTANI Ichimin

鈴木 宏

SUZUKI Masaru

篠原

白木章雄

鈴木治彦

SUZUKI Hiroshi

23, 25, 26, 27, 28, 30,

篠田遼子

SHINOHARA Satoshi

6, 8, 9, 17, 19, 25

ii, 5, 6, 17, 19, 24, 25, 30,ii, 5, 6, 10, 11, 14, 19,

SHINOHARA Atsushi

SHINODA Ryouko

鈴木大介

SUZUKI Haruhiko
23

SHIMIZU Hirohiko

SHIMOURA Susumu

炭竃聡之31, 32

島村智之

SHIMOMURA Koichiro

261

ii, 5

91

SUZUKI Daisuke

SHIMAMURA Isao

SHIMAMURA Tomoyuki

SUKHANOV Andrei

167, 203201

167, 263

杉山正夫

SUMIKAMA Toshiyuki

島田 修

純

須合亮平

iii, 12, 13, 34, 145, 146,SHIMADA Osamu

SHISHIDO Toetsu

207, 208

菅原浩介

杉山168, 169, 170, 176, 177, 180, 181, 182,

SHIBATA Toshiaki

SHIRAKI Akio

須貝宏行

SUGAI Hiroyuki

91

SHAFTO Eugene

SHOJI Kohei

102

田原司睦

iv

TABAYASHI Ayako

田林綾子

253

TAKABE Tomomasa

高部智正

241, 242, 248

TAKAHARA Katsunori
TAKAHASHI Masahiro

高原克典

233

高橋昌宏

259

高橋成人

TAKAHASHI Naruto

高橋 豊

外川

TOGAWA Manabu
TOJO Junji

東城順治
土岐

TOKI Hiroshi

24

22

学

84

168, 169, 170, 182, 183

東海林英夫

TOKAIRIN Hideo

248

高橋良幸

TAKAHASHI Yoshiyuki
TAKAHASHI Yutaka

21, 23, 25, 26, 27, 29

博

253

i, 50

TOMASEK Lukas

170, 182, 183

TOMITA Masanori

冨田雅典

250

TAKAI Kazuyuki

高井和之

233

TOMITA Yoko

富田葉子

221

TAKAMINE Aiko

高峰愛子

37, 147, 166

TORII Hisayuki

鳥井久行

90

高宮幸一

TAKAMIYA Koichi

高野淳平

TAKANO Junpei

38

TOYODA Akihisa

豊田晃久

39

140

TOYODA Takeshi

豊田健司

167

TAKANO Kunihiko

高野邦彦

TAKASE Kenichi

高瀬研以智
武内

聡

武智摩耶

20

TAKAUCHI Satoshi

竹田浩之

TAKEDA Hiroyuki

武田直人

TAKEDA Naoto

筒井智嗣

204

内田

iii, 12, 13, 167

159, 160

UE Koji

竹村 真

TAKIMI Tomohisa

瀧見知久

玉城

民井

淳

TAMURA Jun

田村 潤iii, 12, 13, 34, 145, 146, 167,
203, 244

上坂友洋

UESAKA Tomohiro

24, 153, 154, 155, 156,
157, 158, 163, 164

宇川彰

172, 174, 175, 176, 177,

UKAWA Akira

178, 179, 180, 181, 182,

UMEBAYASHI Yukihiro
浦井輝夫

183, 186, 187, 190, 191

URAI Teruo

UTSUNO Yutaka

20, 21, 23, 26, 27

UWAMINO Yoshitomo

106

VARENTSOV Victor
193, 194, 195, 196

VINCI Walter

上蓑義朋

269, 270

111

ii, 5, 10, 11, 25, 26, 27

VORONIN Alexandr

91

141, 142, 143

51

147
91

VRBA Vaclav

251

207, 208

VOLKOV Vladimir

24

103
梅林志浩

宇都野穣

35, 36, 162

充

TAMII Atsushi

上野秀樹

UENO Hideki

120, 121, 265, 266

14ii, 5, 8, 9, 10, 11, 14, 17,

聡

玉江忠明

浩二

91, 168, 169, 170, 171,

滝沢慶之

TAKIZAWA Yoshiyuki

誠iii, 12, 13, 34, 167ii, 5, 10, 11, 14, 20
篤武内

TAMAKI Mitsuru

253

上

167

内山暁仁

UCHIYAMA Akito

竹久妃奈子

TAKEUCHI Satoshi

267, 268

TSUTSUI Satoshi

TAKEMURA Makoto

竹谷

筒井亮丞

UCHIDA Makoto

40

竹下英里

月居憲俊

TSUKIORI Noritoshi

242, 248

250

17, 18, 22, 161, 165

TAKEHISA Hinako

TAKETANI Atsushi

45

豊嶋厚史

塚田晃代

TSUTSUI Ryosuke

武田泰弘

TAMAE Tadaaki

TSUKADA Teruyo

25

TAKEDA Yasuhiro

TAKESHITA Eri

TOYOSHIMA Atsushi

高階正彰

TAKASHINA Masaaki
TAKECHI Maya

186, 187
iii, 12, 13, 34, 167

91, 170
和田道治

WADA Michiharu

37, 147, 150, 151, 166

TANAKA Hidekazu

田中秀数

222, 223

WAKABAYASHI Tsutomu

TANAKA Kanenobu

田中鐘信ii, 5, 8, 9, 20, 21, 25

WAKABAYASHI Yasuo

若林泰生

15, 28, 29, 31, 32,

114

WAKASUGI Masanori

若杉昌徳

35, 36, 82, 131, 132,

TANAKA Kan

田中 寛

務

252

田中和廣

TANAKA Kazuhiro

若林

170

33, 34

TANAKA Masahiko

田中雅彦

15

148, 149, 162, 265,

TANASE Masakazu

棚瀬正和

40

266, 267, 268

TANIDA Kiyoshi

谷田

TASHIRO Yuki

田代祐基

聖

84

TER-AKOPIAN Gurgen

21

TERAKAWA Teruhiko

寺川輝彦

WAKUI Takashi
WANG Shuo

261

TERANISHI Takashi

寺西 高

28, 29TERASHIMA Satoru

寺嶋

18, 165

知脇田直次

WAKITA Naotsugu

242, 248

王

涌井崇志
碩

WATANABE Hiroshi
WATANABE Isao257

24, 163, 164

35, 36, 162
渡邉

渡邊功雄

寛

13

v, 167, 217, 218, 219, 220,
221, 222, 223, 224, 225,

THEMANN Harry

69, 168, 169

228, 229, 230, 231, 232,

THOMAS Anthony

93, 94233, 234, 235, 236, 237,

TOGANO Yasuhiro栂野泰宏

ii, 5, 8, 9, 11, 14, 17, 20,

238, 239, 263- ix -

渡辺正成

WATANABE Masashige

渡部 信

WATANABE Shin

139

谷内勇仁

YAUCHI Yuji

38

依田芳卓

YODA Yoshitaka

WATANABE Shizui

渡辺静意

170, 186, 187

WATANABE Sin-ichi

渡辺伸一

133, 134

渡邉

122, 123, 131, 132,

YOKOI Naoto

133, 134, 265, 266

YOKOUCHI Shigeru

WATANABE Yasushi

渡邊 康

WOOD Jeﬀ
XIE Wei

横井直人

111

横内 茂

126, 127, 130, 135, 136,

90, 165, 193, 194, 195,

265, 266, 267, 268

7, 87, 88

WOLLNIK Hermanniv, 65, 66, 67, 90,
197, 198

196, 197, 198, 199
WISE Thomas

204

四日市 悟

YOKKAICHI Satoshi

WATANABE Tamaki

環23

YOKOYAMA Akihiko

横山明彦

38

YOKOYAMA Takashi

横山敬士

252

米田

YONEDA Akira

147, 150, 151

晃

241, 265, 266

米田健一郎

YONEDA Ken-ichiro

7, 87, 88

8, 9, 11, 14, 18, 21,
23, 165

72, 192
矢花一浩

YABANA Kazuhiro
YAGI Eiichi

八木栄一

矢入 聡

吉田

YOSHIDA Akira

207, 208

八尋正信

YAHIRO Masanobu
YAIRI Satoshi

47, 54

晃

18

吉田 敦

YOSHIDA Atsushi

口絵 1

43

7, 口絵 1 8, 10,

14, 22, 37, 147, 199, 203

217, 219

吉田光一

YOSHIDA Koichi

YAKOU Kentarou

矢向謙太郎

24

YAMADA Fumiko

山田文子

222, 223

口絵 1

7, 口絵 1 8, 31,

32, 199
吉田辰彦

YOSHIDA Tatsuhiko

吉田

豊

138

YAMADA Kazunari

山田一成

ii, 5, 8, 9, 11, 14, 19, 20,

YOSHIDA Yutaka

21, 23, 131, 132, 137

YOSHIE Tomoteru

吉江友照

103

YAMADA Norikazu

山田憲和

95, 103

YOSHIMI Akihiro

吉見彰洋

iii, 12, 13, 34, 145, 146,

YAMADA Yasuhiro

山田康洋

243

203

167, 203, 244

YAMAGAMI Masayuki

山上雅之

53

YAMAGUCHI Hidetoshi

山口英斉

15, 28, 29, 30, 33,

YOSHINAGA Naotaka

吉永尚孝

55, 6134, 155, 156

YOSHITAKE Michiori

吉竹利織

20

YAMAGUCHI Mitsutaka

山口充孝

8, 9, 21, 23, 24

YOU Zhengyun

YAMAGUCHI Takayuki

山口貴之

20, 82, 148, 149

YUKAWA Noriko

YAMAGUCHI Yoshitaka

山口由高

82, 148, 149

YUKI Hideyuki

YAMAKI Tsutomu

八巻 務269, 270

山元勝吉

YAMAMOTO Katsuyoshi

山本純大

YAMAMOTO Yoshihiro

吉村

YOSHIMURA Takashi

YUN Xue

湯川憲子
結城英行

薛

芸

269, 270
38

行平憲一

234

ZELENSKI Anatoli

7, 88172, 178, 179, 182,

ZELINSKI Anatoli

87

183

ZENIHIRO Juzo

銭廣十三18, 161, 165
221

YAMAUCHI Hiromoto

山内啓資

265, 266

ZENITANI Yuji

銭谷勇磁

山崎泰規

37, 147, 150, 151, 166,

ZHENG Yong6, 19, 30, 31, 32

209, 210, 211

ZOLIN Leonid

91

柳澤善行

口絵 1

7,

口絵 1

8, 8, 9,10, 11, 14, 17, 25,
26, 27YANO Yasushige

矢野安重

口絵 1

203

168, 169, 170, 171,

YAMAZAKI Yasunori

YANAGISAWA Yoshiyuki

242, 248

90

YUKIHIRA Ken-ichi

257

崇7, 口絵 1 8, 35,

36, 82, 117, 122, 123, 124,
125, 128, 129, 130, 131,
132, 133, 134, 137, 139,
148, 149, 162, 265, 266,
267
YASUDA Yusuke

安田祐介

82, 148, 149

YASUNO Takuma

安野琢磨

20

YATAGAI Fumio

谷田貝文夫

251

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