RIKEN
Accelerator
Progress Report

2003
vol.

独立行政法人

理化学研究所
RIKEN

37

CONTENTS
I.

Page
PREFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1

II.

OPERATION OF ACCELERATORSIII.

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

3

RRC and AVF operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

CGS operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7

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

9

RESEARCH ACTIVITIES

1. Nuclear Physics
Spontaneous-ﬁssion half-lives for heavy and superheavy nuclei . . . . . . . . . . . . . . . . . . . . . . . . .

11

Application of the generalized two-center cluster model to 10 Be and 12 Be . . . . . . . . . . . . . .

12

Tensor correlation in neutron halo nuclei . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13

16 O + 16 O nature of the superdeformed band of 32 S and the evolution of the molecular

structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12 C + 12 C → 8 Be

g.s. +

14

16 O
g.s. resonance reaction and multicluster states of highly

excited 24 Mg nucleus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15

Eﬀect of halo structure on 11 Be + 12 C elastic scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16

A search for a uniﬁed eﬀective interaction for Monte Carlo shell model calculations(V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17

Ground states in even-even nuclei using random interactions . . . . . . . . . . . . . . . . . . . . . . . . . .

18

Triaxiality of neutron-rich Mg isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19

Charge- and parity-projected Hartree-Fock method for strong tensor correlation andits application to the alpha particle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20

Chiral sigma model with pion mean ﬁeld in ﬁnite nuclei . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21

Accurate calculations for few-nucleon systems using low-momentum interactions . . . . . .

22

Shell structure in nuclei around 16 O and 24 O described using modern
nucleon-nucleon interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23

Modiﬁed Hartree-Fock-Bogoliubov theory at ﬁnite temperature . . . . . . . . . . . . . . . . . . . . . . .

24Pairing eﬀect on the giant dipole resonance width at low temperature . . . . . . . . . . . . . . . . .

25

Three-dimensional rotation of even-even triaxial nuclei . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

Required accuracy of mass and half-life measurements planned at future RI-beamfacilities to understand the r-process nucleosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27

Comparison of prolate and oblate explosions in core-collapse supernovae . . . . . . . . . . . . . .

28

Properties of a relativistic equation of state for collapse-driven supernovae . . . . . . . . . . . .

29

Proton-nucleus elastic scattering and the equation of state of nuclear matter . . . . . . . . . .

30

A search for the eﬀect of nuclear outer surface in proton-nucleus elastic scattering . . . . .

31

The behavior of matter at high baryon density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

32

The EMC eﬀect in an eﬀective quark theory for nuclear matter . . . . . . . . . . . . . . . . . . . . . . .

33

Invariant-mass spectroscopy for condensed K̄ nuclear clusters to be formed as residues
in relativistic heavy-ion collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

34

Chiral symmetry in the light-cone ﬁeld theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35

Electron cooling by electron beam of anisotropic velocity distribution with variable
Coulomb logarithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36

Electron cooling by two-temperature electron beam with extremely cold longitudinaltemperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

37

Cooling rate of ion beam by electron cooling with ﬂat electron velocity distribution
with variable Coulomb logarithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

38

Ultimate temperature and cooling time of ion beam by electron cooling: Dependence
on Coulomb logarithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

39

Mathematical tools for electron cooling by electron beam with strongly anisotropic
velocity distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40

Superheavy hydrogen 5 H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

41

Experimental evidence for existence of 7 H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

42

Experimental evidence for a speciﬁc structure of 8 He . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

43

Measurement of the vector analyzing power for the p + 6 He, 71 MeV/nucleon elastic
scattering using spin-polarized solid proton target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

Experimental test of Bell’s inequality via the (d, 2 He) reaction . . . . . . . . . . . . . . . . . . . . . . . .

45

Spectroscopy of 13 B via 4 He(12 Be,13 Bγ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46

11 C(p,γ)12 N reaction studied by the Coulomb dissociation method....................

47

Molecular states in 12 Be and 14 Be . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

48

Isomeric 0+ state in 12 Be . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

49

Coulomb and nuclear breakup of 11 Li . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

50

Measurement of reaction cross section for 17 C and ﬁnite-range Glauber model
analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

51

Measurement of the reaction cross section for 17 B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

52

Mean lifetime of the ﬁrst excited state in 16 C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

53

In-beam gamma spectroscopy and search for isomeric states in 17,19 C . . . . . . . . . . . . . . . . . .

54

In-beam γ-ray spectroscopy of Ne isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

55

Excited states in 27 F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

56

Gamma-ray spectroscopy of 23 F with proton transfer reaction . . . . . . . . . . . . . . . . . . . . . . . . .

57

Gamma-ray spectroscopy of 22 O with α inelastic scattering . . . . . . . . . . . . . . . . . . . . . . . . . . .

58

Invariant-mass spectroscopy of 16 B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

59

Inelastic scattering of 15 B and 17 B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

60

Proton inelastic scattering of 19 C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

61

First excited state of 30 Ne studied by proton inelastic scattering in reversed
kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

62

Search for low lying dipole strength in the neutron rich nucleus 26 Ne . . . . . . . . . . . . . . . . . .

63

Direct measurement of the astrophysical reaction 14 O(α, p)17 F . . . . . . . . . . . . . . . . . . . . . . . .

64

Study of astrophysically important resonance states in 26 Si and 27 P using radioactive
ion beams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

65

Study of the resonant state in 23 Al relevant to the stellar 22 Mg(p,γ)23 Al reaction . . . . . .

66

Beta decay half-lives of neutron-rich Cr, Mn, Fe, and Co isotopes . . . . . . . . . . . . . . . . . . . . .

67

Investigation of resonant states in 23 Al and 22 Mg using RI beams . . . . . . . . . . . . . . . . . . . . .

68

Study of the 26 Si(p, γ)27 P reaction by the Coulomb dissociation method . . . . . . . . . . . . . . .

69One-neutron halo structure in 15 C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70

g-factor measurement for 19 N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

71

Development of low energy 8 Li beam at CRIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

72

Production of low-energy secondary beam for secondary reactions . . . . . . . . . . . . . . . . . . . . .

74

Development of 17 N secondary beam II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

75

Electromagnetic transition matrix elements of proton-rich 46 Cr, 50 Fe, and 54 Ni
studied by Coulomb excitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

76

Intermediate-energy Coulomb excitation of neutron-rich Ge isotopes around N = 50 . . .

77

Production cross sections of neutron-rich Ca and Ni isotopes formed by fragmentationof a 63 A MeV 86 Kr beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

78

Lifetime of a new high-spin isomer in 150 Dy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

79

Production and decay properties of 272 111 and its daughter nuclei . . . . . . . . . . . . . . . . . . . . .

80

Electron scattering from unstable nuclei by a novel SCRIT method . . . . . . . . . . . . . . . . . . .

81

Development of liquid hydrogen target for EPR experiment at SMART . . . . . . . . . . . . . . .

82

Evidence for a deeply bound kaonic system K − ppn in the 4 He (stopped K − , n)reaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

84

Experimental signature of in-medium mass modiﬁcation of vector mesons at normal
nuclear density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

85

Nuclear mass number dependence of inclusive ω and φ meson production in 12 GeV
p-A collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

86

Geant4 simulation for the KEK-PS E325 spectrometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

87

Response of the HXD-II detector to cosmic heavy ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

88

Dimuon measurement in the NA60 experiment at CERN/SPS . . . . . . . . . . . . . . . . . . . . . . . .

89

First measurement of muon transfer reactions with argon ions implanted in solid
deuterium ﬁlms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

90

Measurement of the magnetic ﬁeld eﬀect in muon catalyzed fusion . . . . . . . . . . . . . . . . . . . .

91

2. Atomic and Solid-State Physics
SF6 dielectric molecules: Electron and positron scattering dynamic properties andpossible applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

93

H+ + CH2 collisions below the 1.5 keV regime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

94

Resonant coherent excitation of 2s electron of Li-like Fe and Ni ions . . . . . . . . . . . . . . . . . . .

95

Elastic wave from fast Xe-ion irradiation on solids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

96

Eﬀect of GeV-ion irradiation on Fe-Ni invar alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

97

Evaluation of single-event eﬀect in power MOSFET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

98

Collective luminescence of extremely dense electron-hole pairs created in ion tracks ininsulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

99Comparative study on electron-hole plasma formed in heavy-ion irradiated MgO andCdS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

101

A new type of positron accumulator in UHV utilizing a high-density electron plasma
and an ion cloud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

102

Soft X-ray spectroscopy of 2.3 keV/u N6+ ions transmitted through a Ni
microcapillary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

103

Coincidence measurements of X rays and ﬁnal charge state of highly charged ionstransmitted through a microcapillary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

104

Multiple-electron processes in close single collisions of Neq+ (q = 2, 5, 7, and 9) withAr at 14 keV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

105

Photodissociation for recovery of Ca+ ions lost by chemical reactions in an ion trap . . .

106

Experimental apparatus for X-ray spectroscopy with highly charged ion beam
produced by laser ion source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

107µSR study on magnetic property of [Pd(dmit)2 ] salts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

109

A change in the Cu-spin ﬂuctuations studied by µSR in La2−x Srx CuO4 atapproximately 100 K . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

110

3. Radiochemistry and Nuclear Chemistry
99 Ru Mössbauer spectroscopic study of CaRuO (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3

111

Reactions of 57 Mn implanted in solid oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

112

Accumulation of various trace elements in Lotus japonicus using the multitracer
technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

113

Eﬀects of carnosine (β-alanyl-L-histidine) on the absorption of various trace elements
in rats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

114

Eﬀects of carnosine (β-alanyl-L-histidine) on the absorption of iron in rats . . . . . . . . . . . .

115

Multitracer screening of trace elements in brains of mice injected withlipopolysaccharide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

116

Pharmacokinetic study on gastrointestinal absorption and blood disposition of
vanadium ions in healthy rats using radiotracer method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

117

Uptake of 65 Zn in various trophoblast cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

118

Metal-binding factor responsible for variation of concentration of trace elements underZn-deﬁcient condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

119

Uptake of metals in cisplatin-resistant lung cancer cell line . . . . . . . . . . . . . . . . . . . . . . . . . . . .

120

Relationship of reactive oxygen species generation with DNA binding and DNA
cleaving activities of metallothioneins I and II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

121

Investigation of intracellular kinetics of copper in HepG2 cell lines . . . . . . . . . . . . . . . . . . . .

122Comparison of technetium and rhenium uptake rates from nutrient solution byradish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

123

Removal of technetium and other trace elements by bacteria living in surface water
covering paddy ﬁelds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

124

Improved separation of Ba and Mg ions in the alkaline earth group using thecentrifugal partition chromatograph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

125Improved extractive separability of metal ions with sulfonated crown ethers . . . . . . . . . . .

127

Study on Re and Os removal from seawater to sediments using multitracer techniqueand X-ray absorption near-edge structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

128

Anion-exchange behavior of element 104, rutherfordium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

130

Performance of a gas-jet-coupled multitarget system for multitracer production . . . . . . .

132

Development of a new target system for online multitracer preparation . . . . . . . . . . . . . . . .

134

Preliminary study on olfactory transport of a multitracer produced in Ti target . . . . . . .

135

Multitracer imaging in plants by GREI system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

136

Implementation of GREI system with DOI measurement capability . . . . . . . . . . . . . . . . . . .

137

Three-dimensional imaging by GREI system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

138

Reconstruction methods for GREI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

139

A note on the reconstruction method for GREI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

140

Image reconstruction method with compensation for scattering angular uncertainty
in MT-GEI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

141

4. Radiation Chemistry and Radiation Biology
Exposure of frozen human cells to heavy ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

143

Eﬀects of heavy-ion irradiation on DNA replication in mammalian cells . . . . . . . . . . . . . . .

144

Eﬀect of heavy ions on the activation of DNA double-strand break repair proteins . . . . .

145

High dose of heavy-ion beams cause p53 -dependent cell death . . . . . . . . . . . . . . . . . . . . . . . . .

146

Eﬀect of heavy-ion beam irradiation on mutation induction in Arabidopsis thaliana . . .

147

Isolation of light stress response mutants of Arabidopsis thaliana by heavy ion beamirradiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

148

Hormesis of heavy-ion irradiation to lettuce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

149

Mutation induction by heavy-ion beam in asparagus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

150

Eﬀect of heavy-ion beam irradiation on apple and Japanese pear . . . . . . . . . . . . . . . . . . . . . .

151

Eﬀects of heavy-ion beam irradiation on regeneration of shoots from stem segmentsin spray-type chrysanthemum (Dendranthema grandiflorum (Ramat.) Kitamura) . . . . . .

152

5. Instrumentation
Performance of strip Ge telescope for in-beam γ-ray spectroscopy . . . . . . . . . . . . . . . . . . . . .

153

Development of NaI(Tl) calorimeter for charged particles . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

155

Development of triggerable focal plane detector with particle identiﬁcation
capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

156

Development of superconducting series junction detectors for heavy ions . . . . . . . . . . . . . .

157

Performance study of the big ion chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

159

Design of 4-layer magnetic shield for spin maser experiment . . . . . . . . . . . . . . . . . . . . . . . . . . .

160

Detector R&D for the beta neutrino correlation experiment . . . . . . . . . . . . . . . . . . . . . . . . . . .

161

Performance of a multiple-reﬂection time-of-ﬂight mass spectrometer . . . . . . . . . . . . . . . . . .

163

Numerical investigation of the “fair-wind gas cell” concept for slow RI-beamproduction at RIKEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

165

FOV and angular response of the APEX onboard French-Brazilian microsatellite . . . . . .

167

Accelerator test of charge particle detectors for a satellite instrument STEP-F . . . . . . . .

168

Design of an RF beam splitter for a time-sharing beam delivery to BigRIPS and
RIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

170

Test experiment on the low-energy RI extraction system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

171On-line collection of 8 Li ions from the projectile fragment separator using an rf ion
guide system (III) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

173

Design of RI extraction system with a static electric ﬁeld . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

175

Development of slow muon beam line at the RIKEN-RAL muon facility . . . . . . . . . . . . . . .

176

Preparation of self-supporting boron ﬁlms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

177

R&D study of a self-conﬁning radioactive ion target (SCRIT) . . . . . . . . . . . . . . . . . . . . . . . . .

179

Loop-gap resonator for polarized proton target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

181

Feasibility study of monolithic SSD for measurement of low energy nuclear reaction
with GEANT4 simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

183

A fast data acquisition front-end using an FPGA device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

185

Present status of data acquisition system ‘BabarlDAQ’ for nuclear physics
experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

187

Network and computing environment for RIKEN Accelerator Research Facility . . . . . . . .

189

6. Material Analysis
Application of an in-air high-resolution PIXE system to direct speciation of Cr andFe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

191

Gamma rays from iron, aluminum and rock targets bombarded by 210 MeV protons . . .

193

7. RIKEN-BNL Collaboration
QCD and dimensional deconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

195

Single spin asymmetry in inclusive D meson production at RHIC . . . . . . . . . . . . . . . . . . . . .

196∆g(x) uncertainty from prompt photon production at RHIC Spin . . . . . . . . . . . . . . . . . . . . .

197

On a negative AπLL at moderately large p⊥ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

198

Threshold resummation for heavy-ﬂavor photo-production . . . . . . . . . . . . . . . . . . . . . . . . . . . .

199

The parton structure of the nucleon and precision determination of the Weinberg
angle in neutrino scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

200

Energy loss of leading parton in hot QGP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

201

Power counting in the high density eﬀective theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

202

Interplay between soft and hard hadronic components for identiﬁed hadrons at
RHIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

203

Hadronization at RHIC: Recombination vs. fragmentation? . . . . . . . . . . . . . . . . . . . . . . . . . . .

204

New signature of the QCD critical point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

205

Pseudogap of color superconductivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

206

Color ferromagnetic phase at ﬁnite quark density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

207

Kinetic equation for φ4 theory with generalized Kadanoﬀ-Baym ansatz . . . . . . . . . . . . . . . .

208

Charge symmetry breaking in few-nucleon systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

209

Lattice chiral symmetry with hopping interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

210

Comparison of matrix model and lattice data for the QCD Dirac operator atnonzero chemical potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

211

Calculations of correlators and spectral function and properties of QGP . . . . . . . . . . . . . . .

212

MEM analysis of the thermal glueball from SU(3) lattice QCD . . . . . . . . . . . . . . . . . . . . . . . .

213

Lattice study of pion electromagnetic form factor with domain wall fermions . . . . . . . . . .

214

Application of DWF to heavy-light mesons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

215

Static potential with dynamical domain-wall quarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

216

Kaon B parameter from two-ﬂavor dynamical domain wall fermions . . . . . . . . . . . . . . . . . . .

217

Kaon matrix elements in domain-wall QCD with DBW2 gauge action . . . . . . . . . . . . . . . . .

218

Lattice study of negative-parity baryon spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

219

Nucleon on the lattice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

220

Status of the QCDOC computer project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

221

The RHIC spin program: Where are we? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

222

The PHENIX run 2003 and early results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

223

Measurement of J/ψ with PHENIX muon arms in 2003 p+p collisions . . . . . . . . . . . . . . . .
√Single muon analysis of polarized proton-proton collision at s = 200 GeV . . . . . . . . . . . .

224
225

√
sN N = 200 GeV p+p collisions at RHIC-PHENIX . . . . . . .

226

Measurement of relative luminosity in polarized proton collision at PHENIX . . . . . . . . . .

227

Measurement of AN of inclusive particles√ by PHENIX BBC with tagged very forward
neutron in polarized pp collisions at s = 200 GeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

228

Identiﬁed hadron spectra in

Measurement√of longitudinal double spin asymmetry for π 0 ’s in proton-proton
collisions at s = 200 GeV from RHIC PHENIX Run 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
√Measurement of π 0 production in p+p and Au+Au collisions at sN N = 200 GeV . . . . .

229
231

Simulation studies
for the Si-Vertex Tracker at PHENIX photon-jet production in pp√
collisions at s = 200 GeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
√Charged hadron analysis in proton-proton collisions at s = 200 GeV . . . . . . . . . . . . . . . . .

233

Backgroundstudy of direct photon production in proton-proton collisions at√
s = 200 GeV with PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

234

Radial ﬂow study from identiﬁed hadron spectra in Au+Au collisions at√
sN N = 200 GeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
√Single electron measurement in sN N = 200 GeV Au+Au collisions . . . . . . . . . . . . . . . . . . .
√Particle composition at high pT in Au+Au collisions at sN N = 200 GeV . . . . . . . . . . . . .
√π 0 event anisotropy in sN N = 200 GeV Au+Au collisions . . . . . . . . . . . . . . . . . . . . . . . . . . . .

232

235
236
237
238

Measurement of ﬂuctuations in event-by-event Nch − Nγ balance . . . . . . . . . . . . . . . . . . . . . .
√Search for non-hadronic sources of photons in Au+Au collisions at sN N = 200 GeV
at RHIC-PHENIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

239

AGS snake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

241

Detection of very small angle proton-proton elastic scattering for absolute polarimetryat RHIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

243

Polarimetry in RHIC and AGS from Run-03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

245

PHENIX local polarimeter, RUN III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

246

Dead layer thickness measurement of Si detectors for the RHIC pC CNI polarimeter . .

247

J/Ψ production in pp and d-Au collisions in PHENIX muon arms . . . . . . . . . . . . . . . . . . . . .

248

PHENIX silicon upgrade project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

249

Development of silicon pixel detectors for the PHENIX experiment . . . . . . . . . . . . . . . . . . . .

250

Development of silicon strip detector for PHENIX silicon vertex tracker . . . . . . . . . . . . . . .

251

Development of pilot readout electronics for the PHENIX pixel detector . . . . . . . . . . . . . . .

253

Semileptonic decays of open charm and beauty in the PHENIX central arm with thesilicon vertex detector upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

254

Muon trigger upgrade with W production for PHENIX muon arms . . . . . . . . . . . . . . . . . . . .

255

eRHIC: Progress and status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

256

CCJ operation in 2002–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

257

Azimuthal asymmetries in fragmentation processes at Belle . . . . . . . . . . . . . . . . . . . . . . . . . . .

259

240

Progress on precision measurement of fragmentation functions at Belle . . . . . . . . . . . . . . . .

260

Development of trigger and DAQ system for SVD2.0 at Belle . . . . . . . . . . . . . . . . . . . . . . . . .

261

8. MiscellaneousIV.

Pumping 229m Th by hollow-cathode discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

263

Study on beam instability due to space charge oscillation during longitudinal bunch
compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

264

DEVELOPMENT OF ACCELERATOR FACILITIES

Production of intense 58 Fe and 64 Ni beams using MIVOC method . . . . . . . . . . . . . . . . . . . . .

265

Optimization of magnetic ﬁeld conﬁguration for the production of Ar ions from RIKEN
18 GHz ECR ion source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

267

Emittance measurement for intense beam of heavy-ions from RIKEN 18 GHz ECRIS . .

269

Control system for a Hyper ECR ion source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

271

Improvement of power supplies for RARF beam transport magnets . . . . . . . . . . . . . . . . . . .

273

Design of vacuum pumping unit for RIBF beam transport lines . . . . . . . . . . . . . . . . . . . . . . .

275

Longitudinal emittance measurement of the RRC beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

276

Expansion of the control system for RARF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

277

N-DIM as controller of devices for beam transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

279

HIS:The radiation safety interlock system for the RIKEN RI Beam Factory . . . . . . . . . . .

281

Charge strippers for the RIKEN RI-Beam Factory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

283

Low-power test of the IRC ﬂattop resonator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

284

Status of booster ring cyclotrons for the RIKEN RI Beam Factory . . . . . . . . . . . . . . . . . . . .

285

Magnetic ﬁeld perturbations from the injection and the extraction elements of the
RIKEN SRC and their correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

287

Cranes for RIBF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

289

Current status of the control system development at RIKEN RI-Beam Factory . . . . . . . .

291

Status of the BigRIPS separator project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

293

Design study of the high-power production target for the Big-RIPS separator . . . . . . . . .

295

Design of an air-core type superconducting quadrupole for the BigRIPS separator . . . . .

297

Gas-cooled current lead with multiple electrodes for BigRIPS superconducting
quadrupoles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

299

Design of radiation shielding for the BigRIPS separator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

301

Conceptional design of the high-power beam dumps for BigRIPS . . . . . . . . . . . . . . . . . . . . . .

303

Prototype of the high-power beam dump for BigRIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

305

Rf system with HOM damped cavity using SiC microwave absorbers for electron
storage ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

306

V.

Measurement of rf characteristics of magnetic-alloy-loaded cavity using cut-core
conﬁguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

308

Development of an HTS-SQUID DC current monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

310

Feasibility of projectile-fragment-beam separation from a secondary beam in a storage
ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

312

Numerical simulation of crystalline ion beam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

314

RADIATION MONITORING

Routine work for radiation safety in the ring cyclotron facility . . . . . . . . . . . . . . . . . . . . . . . . .

317

VI.

LIST OF PUBLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

319

VII.

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

331

VIII.

PAPERS PRESENTED AT MEETINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

333

IX.

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

352

X.

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

354

XI.

LIST OF PERSONNEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

360

AUTHOR INDEXBack to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

I. PREFACE

This issue of RIKEN Accelerator Progress Reportreports research activities of the RIKEN Accelerator
Research Facility (RARF) up to October 2003. The
research programs involve a variety of ﬁelds such as
nuclear physics, nuclear chemistry, radiation biology,
atomic physics, condensed matter physics, plant mutation, material characterization, application to spacescience, accelerator physics and engineering, laser technology, and computational technology in terms of accelerator or radiation application. These activities
involved a few hundred researchers from domestic
and foreign institutions together with laboratories andCenters in RIKEN.
Major research activities of the RARF are based on
the heavy-ion accelerator complex consisting of theK = 540 MeV RIKEN Ring Cyclotron (RRC), theenergy variable heavy-ion linear accelerator (RILAC),
and the K = 70 MeV azimuthally varying ﬁeld (AVF)
cyclotron. Heavy-ion beams of a variety of elementswith energies ranging from a few A MeV to 135 A MeV
are provided. The two-injector machines (AVF and
RILAC) are equipped with ECR heavy-ion sources.
Vector and tensor polarized deuterons are also available. The three accelerators have been used in various conﬁgurations. The RRC operates either with the
AVF or the RILAC as the injector. The AVF has been
providing beams of ions of mass numbers up to 60,
whereas the RILAC can accelerate heavier ions. An energy booster called CSM (Charge State Multiplier) has
been installed in collaboration with CNS, the University of Tokyo, so that the maximum beam energy fromthe RILAC has been raised. This enabled to deliver
high-intensity beams of intermediate mass elements
such as Kr up to 64 A MeV from RRC. In addition,
RILAC and RRC can be operated separately, when the
AVF is used to inject ions to the RRC. This allows forlong runs with RILAC beams like the experiment ofsuper-heavy element search. Two thirds of the RRC
research beam time is used for nuclear physics and nuclear astrophysics, and remaining one third is used foratomic physics, material science, nuclear chemistry, radiation biology and others. The AVF beam time wasalso used for ﬁelds other than nuclear physics.
The RARF carries many international collaborations. Among them are two large-size collaboration
programs using overseas accelerator facilities: one is
the muon science project at ISIS in collaboration with
the Rutherford-Appleton Laboratory (RAL), and theother is the spin physics program at RHIC in collaboration with the Brookhaven National Laboratory (BNL).
The pulsed muon-beam facility at ISIS has been oper-

ating steadily. At the RHIC facility, the ﬁrst data fromlongitudinally polarized proton collisions have been obtained. Other smaller collaborations using foreign facilities are underway at Lanzho (China), Dubna (Russia), CERN (Switzerland/France), GSI (Germany),
TRIUMF (Canada), and MSU (United States). We
have collaborated with the CNS for installing the lowenergy RI beam separator (CRIB) to use the lowenergy beam from the AVF. Light RI beams of a few
A MeV are now available as a CNS/RIKEN facility,
and several experiments have been performed.
Highlights of the year for the research at RARF are
as follows. (1) Experiments for super-heavy element
search have been performed. Alpha-decay chains fromresidues of the 64 Ni + 209 Bi fusion reaction have been
observed, and production of the element 272 [111] hasbeen conﬁrmed. Together with earlier results at GSI,
properties of the decays have been revealed. An experiment to search for the element 113 is underway. (2)The lifetime of the ﬁrst excited state in 16 C has beenmeasured. Its extraordinarily large value together withthe large neutron excitation component extracted fromthe 16 C + 208 Pb inelastic scattering results indicate
anomalous dynamics of 16 C excitation. (3) The 19 N
magnetic moment has been measured. (4) New techniques are being developed to accumulate slow RI ionsfrom the fragment separator. The highest eﬃciency
of around 3% was achieved for the method based on
the gas-ﬁlled rf-ion guide. (5) A novel technic of TOF
mass spectroscopy is being developed. Mass accuracyof 0.7 ppm has been achieved. (6) The reaction crosssection for C isotopes (14,15,17 C) and half lives for Cr,
Mn, Fe, and Co isotopes have been measured. (6) Behavior of neutron-rich N = 20 isotopes was studied.
The energy of the ﬁrst excited state in 30 Ne, which
was measured by a (p,p’ γ) experiment in reversed
kinematics, indicates that the neutron shell closure disappears in this nucleus. (7) The rf deﬂector, which was
installed in the last year, has been successfully used forexperiments with proton-rich RI beams.
The RI Beam Factory project is in progress. The
building for the cyclotrons and fragment separators has
been completed, and the experimental facility building
is being built. Most of the main components of thecyclotrons IRC and SRC has been fabricated, and theirinstallation in the building has been started. The ﬁrst
production of RI beams are foreseen in the year 2006.

T. Motobayashi
Leader, Accelerator-based Research GroupRIKEN Accelerator Research Facility

1Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

RILAC operation
E. Ikezawa, M. Kase, S. Kohara, O. Kamigaito, T. Nakagawa, M. Fujimaki, M. Nagase, T. Kageyama,
N. Fukunishi, N. Sakamoto, H. Okuno, N. Inabe, M. Wakasugi, M. Kobayashi-Komiyama, M. Kidera,
S. Yokouchi, A. Yoneda, H. Ryuto, M. Hemmi, I. Yokoyama, Y. Higurashi, T. Aihara,∗ T. Ohki,∗
H. Hasebe,∗ H. Yamauchi,∗ A. Uchiyama,∗ K. Oyamada,∗ A. Goto, and Y. Yano
During this reporting period, RILAC has been insteady operation and has supplied various ion beams
for various experiments. Table 1 shows the statistics for RILAC operation from January 1 through December 31, 2003. Table 2 summarizes the number ofdays allotted to diﬀerent research groups. The percentage of beam time used by the RIKEN Ring Cyclotron (RRC) was approximately 31% of the total.
The 40 Ar, 48 Ca, 58 Ni, 86 Kr, 136 Xe, and 181 Ta ions accelerated by RILAC were injected into RRC. Amongthese, the 40 Ar, 48 Ca, 86 Kr, and 136 Xe ions were accelerated by RILAC together with the charge-state multiplier (CSM) A1 and A2 cavities and injected into RRC
with a harmonic number of 8.
Research experiments on superheavy elements havebeen carried out with a gas-ﬁlled recoil isotope separator (GARIS) at the e3 beam line. The total beamservice time for the experiments was 2413.3 hours.
Tables 3 and 4 show the statistics for the numbersof days on which RILAC ion beams were delivered using the Cockcroft-Walton injector with an 8 GHz ECRion source (NEOMAFIOS) and using the RFQ linac
with an 18 GHz ECR ion source, respectively. The ion
beams of 10 elements were used for the experiments
and beam acceleration tests.

Table 3. Statistics for RILAC ion beams delivered using
the Cockcroft-Walton injector with an 8 GHz ECR ion
source (NEOMAFIOS).
Ion

Mass

Charge state

Ar
Ni
Kr
Ta

40
58
86
181

8
9
18
16
Total

No. of
Days
2
3
1
2
8

Table 4. Statistics for RILAC ion beams delivered using
the RFQ linac with an 18 GHz ECR ion source.
Ion

Mass

N
Ar
Ca
Ni
Ni
Zn
Kr
Kr
Xe
Ta

14
40
48
58
64
70
84
86
136
181

Charge state

3
8, 11
11
9
13
16
17
18
18, 20, 26, 27
20, 24Total

No. of
Days
1
14
10
6
52
82
2
17
19
5
208

Table 1. Statistics for RILAC operation from January 1
through December 31, 2003.

Beam time
Overhaul and improvement
Periodic inspection and repair
Scheduled shutdown
Total

No. of
Days
216
56
45
48
365

We carried out the following machine improvements
during this reporting period.

%
59.2
15.3
12.3
13.2
100

Table 2. Beam time allocated to diﬀerent research groups.

Atomic physics
Nuclear physics
Radiation chemistry
Material analysis and development
Accelerator research
Beam transport to RRC
Total∗

SHI Accelerator Service, Ltd.

No. of
Days
4
134
7
2
3
66
216

%
1.9
62.0
3.2
0.9
1.4
30.6
100

(1) The power supplies for the drift tube magnets
used in the No. 1, No. 2 and No. 3 cavities and forthe quadrupole magnets installed after each cavity were replaced with new ones, because they
were worn out from many years of operation.
Each new magnet power supply is of the switching type and has a network IO (NIO) interface.
(2) In the beam transport line between the No. 1
and No. 6 cavities, the Faraday cups, the beam
proﬁle monitors and the phase probes were replaced with new ones in order to improve theirstrengths against the high beam intensity extractable from an 18 GHz ECR ion source. They
were mounted on a new diagnostic chamber.
(3) The vacuum system using the turbomolecular
pumps of 150 l/s was newly installed in the beamtransport line between the No. 1 and No. 6 cavities. In the experimental room, the vacuum3

system for the beam transport line was also replaced with a new one.
(4) The power supplies for the dipole magnets (ADM2, A-DM-3 and GARIS-D) were remodeledby replacing the current shunt with the DC current transformer.1)
We experienced the following machine problems during this reporting period.
(1) In the rf power ampliﬁer of the RFQ linac, therf contact ﬁnger was melted due to the excessive
rf current. The rf power ampliﬁer was improved
this summer.
(2) The 18 GHz ECR ion source was splashed withwater due to the presence of a small hole in thecooling pipe of the water jacket for the hexapole
magnet.
(3) In the No. 2, No. 5, and No. 6 cavities, a thin

4

copper sheet (10 cm wide, 7 cm long, and 0.3 mm
thick) used for electric contact melted because of
the excessive rf current with parasitic oscillation.
The beam transport line of the RFQ linac withthe 18 GHz ECR ion source will be modiﬁed for
the RIKEN RI beam factory project during January
through February, 2004. Another 18 GHz ECR ion
source will be installed in parallel with the existing
18 GHz ECR ion source in the near future. Thus thebeam transport line of the Cockcroft-Walton injector
with the 8 GHz ECR ion source (NEOMAFIOS), which
has been used for many years, will be dismantled.
References
1) M. Nagase et al.: RIKEN Accel. Prog. Rep. 37, 273(2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

RRC and AVF operation
M. Kase, T. Kageyama, M. Nagase, S. Kohara, T. Nakagawa, E. Ikezawa, M. Fujimaki, N. Inabe, H. Okuno,
O. Kamigaito, M. Kidera, H. Ryuto, M. Kobayashi-Komiyama, N. Fukunishi, N. Sakamoto, M. Wakasugi,
Y. Ohshiro,∗1 A. Yoneda, Y. Higurashi, I. Yokoyama, S. Yokouchi, H. Isshiki,∗2 N. Tsukiori,∗2
K. Takahashi,∗2 T. Maie,∗2 R. Ohta,∗2 K. Kobayashi,∗2 M. Nishida,∗2
Y. Kotaka,∗2 S. Fukuzawa,∗2 A. Goto, and Y. Yano
The RARF accelerators (RRC, AVF and RILAC)
were operated under special budgetary conditions in
2003. To keep the RIBF construction schedule, theoperation budget was reduced by 30%. Moreover, on
the operation budget, the energy source for the accelerators was switched from electricity to gas fuel dueto the introduction of a new power-generation scheme
described below.
The co-generation system (CGS) of the RI Beam
Factory was installed in the spring of 2003 and the gas
turbine in the CGS has started to generate a powerof 6300 kW routinely since April. To reduce the power
cost, the accelerators use electricity from the CGS onlyin the daytime of weekdays and Saturday, and use
commercial power during the other periods when the
charge is quite low. The accelerators had a scheduledlong shutdown (more than 40 days) in the summer andwill have another two-month shutdown in the winterof 2004.
In November and December, experiments using
beams of the RILAC-RRC combination were postponed, and the experiment to search for a superheavy element (Z = 113) exclusively used beams fromRILAC.

For the above reasons, the operation hours of the
RIKEN Ring Cyclotron (RRC) in 2003 was slightly
shorter than the previous years, as shown in Table 1.
Figure 1 shows the history of the RRC operation from1996 to 2003. The RRC routinely provided a beamtime of 3789 hr throughout 2003.
Table 2 shows the statistics of beam time used foreach beam course. Ninety-six experiments were carried out in 2003 using the RRC beams. Among them,

Table 1. Statistics of RRC and AVF operation from Jan.
to Dec. 2003.
Operation time of RRC
Beam Service Time
Machine troubles

5684 hr
3739 hr
239 hrNuclear Physics ExperimentNon-nuclear Physics Experiment

74%
26%

RILAC-RRC Operation
AVF-RRC Operation

11%
89%

Operation time of AVF standalone
Beam Service Time

1582 hr1192 hrFig. 1. Statistics of RRC operation from 1996 to 2003.
∗1∗2

Center for Nuclear Study, University of Tokyo
SHI Accelerator Service, Ltd.

5

Table 2. RRC and AVF beam time for each course in 2003.
Target room

Total time (hr)No. of experiments

E1

100 (257)

6 (6)

E2

117 (157)

3 (4)

E3

342 (275)

13 (15)E4 (SMART)

538 (327)

9 (5)

E5

286 (273)

40 (29)E6 (RIPS)

2342 (3114)

25 (31)

AVF (CO3)158§

E7 (CRIB)
§

§

5§
§

1034 (467 )§

16 (8)

AVF stand-alone only, and used for CNS of the University of Tokyo. Figures in parentheses are data in 2002.

twenty-five experiments using RI beams from RIPS
were carried out in the E6 room and they used a total
beam time of 2342 hr, that is, 63% of the total beamtime.
A total beam time of 1034 hr is used by the Center
for Nuclear Study (CNS) of the University of Tokyo. It
was the second year since the physics experiments foruniversity students started based on the RIKEN-CNS
collaboration agreement. In autumn, four days werespent for these experiments.
The hyper-ECR ion source has been used routinely
for injection of the AVF in collaboration with the CNS,
university of Tokyo. It took charge of the productionof beams such as 12 C, 14 N, 16 O, and 20 Ne, being used
for 60% of the total beam time of the AVF. The performance of the 10 GHz ECR ion source has not been as

6good as before for the production of high-charge-stateions, since it has problems on the hexa-pole magnet
and extraction system.
The high-intensity nature of RRC beams enables us
to provide experimental opportunities like the use ofa parallel beam with an angular divergence less than
10 microradians. These parallel beams were used in
ion-channeling experiments performed in the E2 experimental vault. The typical intensity of the parallel
beam is several hundreds of particles per second. The
power supplies of beam transport magnets were modified to improve the long-time stability of these highprecision beams. Their current detectors were converted from a Zeranin shunts into DCCT (DC current
transformer).
We upgraded the EPICS base programs running on
the server computer for accelerator operation from version R3.13.1 to R3.13.8 in the summer of 2003. It is
expected that we can add new convenient applications
supported by the EPICS community such as an operation archiver to our control system.
It was determined that the use of SMART in the E4
target room will be terminated in the summer of 2005
to install one of the cyclotrons (fRC) of RIBF.
The beam chamber of RRC is being evacuated with
fourteen sets of 10000 l/s cryogenics vacuum pumps.
Five of them had been out of order after more than
10000 hr use. The helium compressors for these pumps
were renewed in the summer of 2003. At the sametime, careful maintenance was carried out for the cryopumps in RARF.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

CGS operation
H. Hasebe,∗ K. Yamaguchi, T. Fujinawa, T. Maie,∗ K. Oyamada,∗ E. Ikezawa, M. Kase, and Y. Yano
The RI Beam Factory (RIBF) requires a gas turbine
co-generation system (CGS)1) to increase the reliability of the power supply, the He-cryogenic system, vacuum system and super-conducting magnets perform
poorly with any interruption of the power supply. The
gas turbine generates electric power from fuel energy
and supplies it to the above systems with top priority. By utilizing gas heat exhaustion from the gas turbine, the CGS will also supply cooled water to thecooling system of the RIBF accelerators as well as tothe building air-conditioning system. The whole system is schematically shown in Fig. 1. Photographs ofthe gas turbine and the overview of the CGS are shownin Fig. 2 and Fig. 3, respectively.
The contract for the CGS construction was signedwith Mitsubishi Electric Co. in Jan. 2002. The installation of the CGS was started in July 2002 on the open
space of the ﬁrst ﬂoor of the RIBF accelerator building, and was completed in Feb. 2003. After inspections and tests had been conducted, the generation of
maximum power (6.3 MW) was achieved at the end of
March 2003. The opening ceremony was held at the
beginning of April with the chairman of the board of
Directors in attendance, and routine operation started
after that.
Until the RIBF is completed in 2005, the CGS will
supply electric power mainly to the RARF accelerators (RRC, AVF and RILAC) during the daytime on
weekdays including Saturday. At night and on holidays and Sundays, the CGS is out of service, because
the rates for commercial electric power are very low
during these periods. On the other hand, this year the

Fig. 2. Photograph of the gas turbine. Air flows from theleft-hand side to the right hand side. Three sets of gas
inlets and igniters are seen in the middle. The turbine
is usually mounted inside the heavy container, whichfunctions as a silencer.

Fig. 3. Over view of the CGS.

Fig. 1. Schematic diagram of the 6300-kW-power class gas turbine cogeneration system with variable
thermal and electrical power.
∗

SHI Accelerator Service, Ltd.

7

use of the exhausted heat is limited to dehumidifying
the accelerator building.
The daily operation schedule of the CGS is as follows. An operator pushes the start button at 7:45
am in the CGS control room in the Nishina Memorial
Building. The gas turbine is ignited at 7:50 am and,after the rotation of turbine reaches up to 14,000 rpm,
the generator is started and synchronized to commercial electric power line at 8:00 am. The full power of
6.3 MW is achieved around 8:45 am by using as muchoutput steam as possible. The stop button of the CGS
is pushed at 9:40 pm and the generator is cut oﬀ fromcommercial electric power line at 10:00 pm. The CGS
is totally stopped at 10:30 pm. The operation statistics
from April to the end of October are shown in Table 1.
We have encountered some premature failures andthe operation was occasionally interrupted. The biannual inspection was carried out in Sept. 2003, and anannual one is scheduled for Feb. 2004. Self-dependence
operations were accidentally initiated on Sept. 3. andOct. 2. The ﬁst operation was triggered by an interruption of the power supply due to a lightning strikeand the second, by an instant voltage reduction. In
both cases, the fully automatic system for providing
non-stop power supply worked successfully in the RIBF
accelerator building.
RIKEN signed a new electric power contract withTEPCO in Oct. 2003. The contract peak power was
reduced from 23.4 MW to 18 MW. This downsizing

8

Table 1. Statistics of CGS operation from April to the endof October, 2003.
Operation time
Scheduled shutdown
Overhaul and improvement
Total

No. of Days
176
29
9
214

%
82.2
13.6
4.2
100

Cost
Electric out put power 13,877,360 KWh 151,981,901 yen
Used gas of the CGS
3,544,958 Nm3 136,423,900 yen
Profit15,558,001 yen

Electrical output only
Inc heat recovery (200 kW)

Unit rate
10.12 yen/kWh9.85 yen/kWh

has resulted in savings of more than 60 million yen
per year. However a full day of operation of what will
be required during the summer in 2004 to keep thiscontract. In Feb. 2004, the CGS will starts to supply
cooled water to the Nishina Memorial Bldg. and the
Linac Bldg. mainly for the air-conditioning systems of
the existing accelerator vaults. It is expected that the
proﬁts of the CGS will grow somewhat in 2004.
References
1) T. Fujinawa et al.: RIKEN Accel. Prog. Rep. 36, 310(2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Operation of the tandem accelerator
T. Kobayashi and K. Ogiwara
The 1.7 MeV tandem accelerator (pelletron) was operated for a total of 119 days for experiments, except
for the time required for machine inspection and beam
test (36 days), during the annual reporting period from
Nov. 1, 2002 to Oct. 31, 2003.
Experimental studies on the following subjects were
performed, and are still in progress.
(1) Nuclear reaction analysis (NRA) (61 days)(a) Lattice location of hydrogen in Nb-based alloys by means of the channeling method(2) Particle-induced X-ray emission (PIXE) (38days)(a) Development of a highly sensitive highresolution in-air PIXE system for chemical
state analysis(b) Trace element analysis of biological and environmental samples using energy dispersive
X-ray spectrometry(c) Characterization of the II-VI ternary semiconducting crystals(3) Rutherford backscattering spectroscopy (RBS)and Elastic recoil detection (ERD) analysis (20days)(a) RBS analysis of polymers and carbon materials containing metallic nanoparticles(b) ERD analysis of diamond-like carbon (DLC)
thin films determining hydrogen contents
The total time in days, which was spent for eachexperiment, is shown in parentheses.

9Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Spontaneous-fission half-lives for heavy and superheavy nuclei
H. Koura∗[Spontaneous ﬁssion, Lifetimes]
Our group has constructed and is developinga method of estimating the potential energy surface
for spontaneous ﬁssion1) using a method of calculating shell energies in a nuclear mass formula.2,3) In thisformula, the shell energy of a deformed nucleus is expressed as a sum of an appropriate mixture of spherical shell energies and an average deformation energy.
The potential energy surface for spontaneous ﬁssion
can be obtained by considering not only the equilibrium shapes but also the intermediated ones. With theabove energy surfaces, we estimate the spontaneousﬁssion half-lives. We take the one-dimensional WKB
method as a virtual particle with an even-odd hindrance factor. That is,
Tsf
s 


2
+ log10 (NColl ) − 0.159= log10 1 + exp K(1)+ hδoddZ + hδoddN − ∆oo δoddZ δoddN ,log10

Fig. 1. Experimental and calculated log10 (Tsf /(s)).

with

 
K=
2kµ(V (ξ) − Egs ) dξ.

(2)Here, µ is a reduced mass of the symmetric ﬁssion fragments. The path ξ is described by the diﬀerential ofthe deformation parameters α as1dξ = r0 A 3 dα,(3)and taken to proceed to the lowest energy towards theprolate shapes. In this study, we take the α2 , α4 , α6deformations in the range −0.2 < α2 < 0.5.
Among the above parameters, we take r0 = 1.2 fm,
and NColl = 1020.38 . The value of k in Eq. (2) is adjusted to reproduce the experimental Tsf for even-evennuclei. The values of h and ∆oo in Eq. (1) are adjusted for odd-A and odd-odd nuclei after ﬁxed k. The
results are k = 6.90, h = 3.54, and ∆oo = 3.0. Figure 1 shows experimental and calculated log10 (Tsf /(s))
for even-even nuclei. The root-mean-square deviationfrom experimental ones is 3.33.
Figure 2 shows the most dominant decay modes calculated from the above estimation. We can ﬁnd thatthe region of ﬁssioning nuclei is located in three areas:
the nuclei near the proton-drip line with 130  N 150, the nuclei with Z ≈ 106 and N ≈ 168, and thenuclei with N  184 and N/Z  1.9.
∗

Advanced Research Institute for Science and Engineering,
Waseda University

Fig. 2. Shortest partial half-lives among α-decay (α),β-decay (β) and spontaneous fission (sf). α: Calculated
from formula (B) in Ref. 4. β: Calculated from thegross theory.5) sf: This work. The Q values of KUTY’s
formula are used for the first two calculations.

References
1) H. Koura et al.: RIKEN Accel. Prog. Rep. 35, 26(2002).
2) H. Koura et al.: Nucl. Phys. A 674, 44 (2000).
3) H. Koura et al.: RIKEN Accel. Prog. Rep. 36, 9 (2003).
4) H. Koura: J. Nucl. Radiochem. Sci. 3, 201 (2002).
5) T. Tachibana et al.: Proc. Int. Conf. on Exotic Nuclei
and Atomic Masses, Arles, France, 1995-6, edited by
M. de Saint Simon et al. (Editions Frontueres, Gif-surYvette, 1995) p. 763.

11

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Application of the generalized two-center cluster model to 10 Be and 12 Be
M. Ito,∗1 K. Katō,∗2 and K. Ikeda[NUCLEAR STRUCTURE, cluster model, Unstable nuclei]
Recent experiments strongly indicate the existenceof the resonant states which dominantly decay to the6
He+ 6 He and α+ 8 He channels in the excited states of
12Be.1) In 10 Be and 14 Be, similar resonances, decaying
to 4 He + 6 He and 6 He + 8 He, respectively, have also
been reported in recent experiments.1,2) These experiments strongly suggest the existence of exotic cluster
states consisting of the respective He-isotope clusters.
Furthermore, the molecular orbital has been shown toprovide a good description of the low-lying states of
Be isotopes as emphasized by recent studies.3) Therefore, it is important to understand both the molecularorbital formations and the possible appearance of the6
He and 8 He cluster states consistently.
In order to understand the formation of these diﬀerent conﬁgurations equally, we proposed a “generalized
two-center cluster model” (GTCM)4) and applied it to10
Be = α + α + 2n. In this model, the total wave function is expressed in terms of a linear combination of the“atomic-orbitals states” having the (α+n)+(α+n) andα + (α + 2n) structures. The α particle is described bythe (0s)4 conﬁguration in the harmonic oscillator potential (HO) and the valence neutrons are speciﬁed by
the atomic orbitals in which the neutrons are localized
at one of α cores with 0pi orbitals (i = x, y, z) in thesame HO potential. The constructed atomic-orbitals
states are fully antisymmetrized and projected to theeigenstates of the total spin and the parity. The superposition of the atomic-orbital states can generate themolecular orbitals at a small α–α distance as well as
the asymptotic cluster states of α + 6 He and 5 He + 5 He
at a large α–α distance.
The calculated energy surfaces are shown in Fig. 1.4)
We have found that at a short α–α distance (S ≤4.5 fm), the valence neutrons form the molecular orbitals (MO), while in an asymptotic region (S ≥ 6 fm),the valence neutrons are localized at one of α coresleading to the formation of the dinuclear states withthe α + 6 He or 5 He + 5 He conﬁguration. In thesestates, 6 He or 5 He has an intrinsic spin and couples toeach other with relative spin L, which just corresponds
to the so-called “weak-coupling states” (WS). In addition, at S = 4.5–6 fm, we have found that the system has an intermediate coupling scheme between MO
and WS. We also solved the α–α relative motions andconﬁrmed that the energy gains for the three local minimums in the surfaces of A, B and C amount to approximately 1–2 MeV.
∗1
∗2

12

Institute of Physics, University of Tsukuba
Division of Physics, Graduate School of Science, Hokkaido
University

Fig. 1. Adiabatic energy surfaces in 10 Be. The solid surfaces of A, B, C, D, E and F have a dominant compo−
+
−
+
+
+
nent of (π3/2)2 , (σ1/2)2 , (π1/2)2 , (π3/2)2 , (π1/2
σ1/2
) and
+
2
(π1/2 ) , respectively, while the dotted and thin surfaces
−
−
−
σ1/2
) and (σ1/2)2 ,have a dominant component of (π1/2respectively.

Therefore, this model naturally describes the formation of the MO at a short α–α distance as well as thatof WS at an asymptotic region, which was generated
by the change of the orbitals for the valence neutrons
around two α cores. This model also predicts the appearance of the pure α+6 Heg.s. and α+6 He(2+1 ) cluster
states in the J π = 1− and J π = 6+ states, respectively,
which were not discussed in previous studies. The adiabatic energy surfaces of 12 Be with J π = 0+ was also
calculated. We have found that the 6 Heg.s. + 6 Heg.s.
cluster conﬁguration is enhanced in the third excitedsurface. This result suggests that the 0+
3 state will
be interpreted in terms of the molecular state of thisconﬁguration. The extension of GTCM to high spins
where the resonances are observed is now under way.
References
1) M. Freer et al.: Phys. Rev. C 63, 034301 (2001).
2) A. Saito et al.: Prog. Theor. Phys. Suppl. 146, 615(2002).
3) Itagaki et al.: Phys. Rev. C 61, 044306 (2000).
4) M. Ito, K. Kato, and K. Ikeda: Phys. Lett. B, in press.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Tensor correlation in neutron halo nuclei
T. Myo,∗1 K. Katō,∗2 and K. Ikeda[NUCLEAR STRUCTURE, Unstable nuclei, Cluster model, Tensor force]Tensor force is an important component in nuclear
force and plays an important role in the nuclear structure. For example, the contribution of the tensor force
in the binding energy of 4 He is comparable to that of
the central force,1) and triplet-even part is dominant.
In this report, we investigate the role of tensor force
in the structures of the two neutron halo nuclei 6 He
and 11 Li. In most theoretical studies of these nuclei,
the core+n + n model is often used, where the core
nucleus is treated as inert, such as the (0s)4 conﬁguration of 4 He for 6 He. However, under this assumption,
tensor force cannot be incorporated in the core nucleus or in the coupling to the core and valence parts.
Therefore, the eﬀects of tensor force in the two neutron halo nuclei have not been realized yet. For 11 Li
and 10 Li, the lowering of the 1s orbit near the 0p orbit
has been discussed, however, the essential mechanismof this phenomenon is still unclear. It is of interest to
examine the eﬀect of the correlation induced by tensor
force on this problem.
We examine what kind of correlation tensor force(tensor correlation) produces. Tensor force tends tochange the parity of the nucleon single particle orbit
due to the operator of (σ · r). This originates fromthe nature of the pion (pseudoscalar meson) because
tensor force mostly comes from the one-pion-exchange
potential. Then, in 4 He, the 0s and 0p orbits can becoupled by tensor force and the description of 4 He is
extended to (0s)4 + (0s)2 (0p)2 . The amount of dissolution of 4 He can be estimated to be about 10% of the
D-state probability by the exact four-body calculation.
The 2p-2h excitation from 0s to 0p orbits is also
applicable in 9 Li. In 11 Li and 10 Li, the mixing ofsuch conﬁgurations in 9 Li couples to the motion of
the p-wave valence neutron. This produces the Pauliblocking eﬀect, and the total energies of p-wave conﬁgurations of 10 Li and 11 Li are lost, which may be
suﬃcient to cause the energy to degenerate to thatof s-wave conﬁgurations. Then, we expect that tensor correlation can be important to produce the halo
structure.
We show the eﬀect of tensor correlation in the calculation of 4 He, where we use the harmonic oscillator
wave function, and set the length parameter of the 0s
orbit as 1.4 fm to ﬁt the charge radius with the (0s)4
conﬁguration. The length parameter of the 0p orbit isfree to include the higher shell component eﬀectively.
For eﬀective N N interactions, we use the Minnesota,∗1∗2

Research Center for Nuclear Physics, Osaka University
Division of Physics, Graduate School of Science, Hokkaido
University

Furutani2) and G3RS forces for the central, tensor, andLS parts, respectively. These are used in the clustermodel calculation. Since the Minnesota force includes
the eﬀect of tensor force, we adjust the triplet-evenpart of this force to ﬁt the binding energy of 4 He.
In Table 1, we show the results of 4 He with threelength parameters of 0p orbit. It is found that whenthe 0p orbit shrinks, the contribution of tensor force
and the 2p-2h probability become large. In particular,
the 0p1/2 orbit is well mixed via 0− coupling to the0s1/2 orbit. This is related to the pion nature.
We also analyze the p-wave resonances of 5 He bysolving the coupled channel problem of 4 He+n, where
the length parameter of 0p orbit of 4 He is 1.0 fm. Since
Pauli blocking mainly occurs in the 1/2− state dueto the 0p1/2 component in 4 He, doublet splitting of
1/2− − 3/2− is induced in 5 He. A folding potential
is used between 4 He and n without an LS interaction.
The results of resonant poles are shown in Table 2,
where KKNN is the phenomenological 4 He-n potentialthat ﬁts the observed phase shifts.3) Our model produces half of the observed splitting, which is consistent
with other studies.4) From the results, the LS interaction of 4 He-n should be reexamined, and the structuresof 6 He related to the 0p1/2 orbit can be improved.
Tensor correlation and Pauli principle strongly aﬀect
the properties of the 0p1/2 orbit. This is crucial in the
inversion problem in 11 Li and 10 Li.
Table 1. Results of 4 He wave functions.
length of 0p orbit [fm]
Vtensor  [MeV]
2p-2h [%]
(0p1/2 )2(0p3/2 )2(0p3/2 )(0p1/2 )

1.8
−1.6
1.8
0.7
0.3
0.8

1.4
−6.4
5.2
3.5
0.1
1.6

1.0
−33.1
18.6
14.8
0.2
3.6

Table 2. Splitting energies in 5 He from two models.
3/2−
1/2−

Present(0.74, 0.45)(1.45, 0.94)

KKNN(0.74, 0.60)(2.13, 5.84)

References
1) Y. Akaishi et al.: Int. Rev. Nucl. Phys. 4, 259 (1988).
2) H. Furutani et al.: Prog. Theor. Phys. 62, 981 (1979).
3) H. Kanada et al.: Prog. Theor. Phys. 61, 1327 (1979).
4) T. Terasawa: Prog. Theor. Phys. 23, 87 (1960).

13

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

16

O + 16 O nature of the superdeformed band of 32 S
and the evolution of the molecular structure
M. Kimura and H. Horiuchi∗[Nuclear structure, Cluster structure]

Recently, a rather conclusive result of the properties of 16 O + 16 O molecular resonance was obtainedby macroscopic models1) using the unique potential.
These studies gave the following results for the lowest three rotational bands whose principal quantum
numbers are N = 24, 26 and 28. The lowest Pauliallowed rotational band (N = 24) starts from the 0+
state located at approximately 9 MeV in the excitationenergy, and the energy gap between the N = 24 andN = 26 bands and that between N = 26 and N = 28
bands are both approximately 10 MeV. In Ref. 1, itis proposed that the observed 16 O + 16 O molecularstates correspond to the third band (N = 28). Asidefrom the molecular bands, the superdeformed state of32
S has also been studied by many authors using themean-ﬁeld theories,2,3) and one of their interests is therelationship between the superdeformed state of 32 S
and the 16 O + 16 O molecular structure. It is notablethat these calculations predict that the superdeformed
band starts from the 0+ located at approximately 8 to
10 MeV which agrees with the energy of the N = 24band head obtained from the unique optical potential.
Therefore, it is suﬃciently conceivable and has been
pointed out by some authors1) that the superdeformed
band and the lowest Pauli-allowed 16 O+ 16 O molecularband (N = 24) are identical.
In the present study, we aim at clarifying the relationship between the superdeformed state and the16
O + 16 O molecular structure. The objectives of thepresent study are summarised as follows. (1) To what
extent are the superdeformed state and the 16 O + 16 O
molecular structure related? In the unique optical potential analysis, the factors which distort the 16 O+ 16 O
cluster structure, such as the eﬀect of the spin-orbit
force and the formation of the deformed mean-ﬁeld,
are renormalised into the optical potential. Therefore,
when we treat these factors accurately using the fullmicroscopic model, the pure 16 O + 16 O structure will
be distorted and can be understood as the superdeformed state of 32 S. (2) Do the excited states exist inwhich the excitation energy is spent to excite the relative motion between the clusters? Do they correspondto the N = 26 and 28 bands obtained from the unique
optical potential? When we consider that the superdeformed states of 32 S have a considerable amount of the16
O + 16 O component, we can expect the excitation
mode in which the excitation energy is used to excite
the relative motion between clusters.
∗

14

Department of Physics, Kyoto University

To investigate these points, we need to apply theframework which can deal with the superdeformed
state (largely deformed one-body ﬁeld) and the molecular structure (two-center structure with the sphericalsubunits) at the same time. We have studied thesepoints with the deformed-base AMD+GCM framework4) which are appropriate for studying the interplayof the deformed mean-ﬁeld structure and the cluster
structure.
In this report, we mention the prominent featureof our results, and readers are directed to Ref. 5
for more detailed discussions. The obtained superdeformed wave function shows the large eﬀect of the distortion of the 16 O + 16 O cluster structure. Namely, thesuperdeformed state obtained by the deformed-base
AMD is more deeply bound than the pure 16 O + 16 O
state by about 10 MeV because of the energy gain in
the density-dependent force and spin-orbit force. The
non vanishing expectation value of the spin-orbit force
at the superdeformed minimum directly indicates the
distortion of the 16 O+ 16 O structure and the formationof the deformed one-body ﬁeld. However, the obtained
superdeformed wave function still has a considerable
16
O+ 16 O component which amounts to approximately
50%. By superposing the obtained wave functions, wehave obtained three rotational bands which correspondto the N = 24, 26 and 28 bands. The lowest band
(N = 24) has a mixed character of the 16 O + 16 O
structure and deformed mean-ﬁeld structure and its
excitation energy agrees well with the superdeformed
state obtained by the mean-ﬁeld calculations. In the
N = 26 and N = 28 bands, we have found that theamount of the 16 O+16 O component increases markedly
and these two bands have an almost pure 16 O + 16 O
structure. At the same time, these band members are
fragmented into several states and the assignment of
the N = 28 band members to the observed 16 O + 16 O
molecular resonances appears plausible.
References
1) S. Ohkubo and K. Yamashita: Phys. Rev. C 66,
021301(R) (2002).
2) M. Yamagami and K. Matsuyanagi: Nucl. Phys. A 672,
123 (2000).
3) R. R. Rodrı́guez-Guzmán, J. L. Egido, and L. M.
Robledo: Phys. Rev. C 62, 054308 (2000).
4) M. Kimura: Phys. Rev. C 69, 052404 (2004).
5) M. Kimura and H. Horiuchi: nucl-th/0311061.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)12

C+12 C → 8 Beg.s. +16 Og.s. resonance reaction and multicluster
states of highly excited 24 Mg nucleus
M. Takashina, M. Ito,∗1 and Y. Sakuragi∗2[nuclear reaction, α-transfer reaction, cluster structure]

In this decade, interesting resonance-like structures
have been observed in the excitation functions of12
C +12 C collisions leading to multicluster exit channels (3α+3α, 3α+12 C, 2α+16 O, etc.),1) particularlyaround Ec.m. = 32.5 MeV. These experimental datasuggest the existence of a new multicluster state ofa highly excited 24 Mg nucleus. In the present study,
we investigate resonance-like structures observed ina 12 C +12 C → 8 Beg.s. +16 Og.s. α-transfer reaction bycoupled-channel Born approximation (CCBA). The
distorted waves are given by coupled-channel (CC) calculations of the 12 C+12 C and 8 Be+16 O systems, using double-folding interactions based on microscopic
cluster-model wave functions2) for 12 C, 8 Be and 16 O.
The T-matrix element of the transfer reaction process
is calculated by Born approximation.
Figure 1 compares the calculated angle-averaged differential cross section for the 12 C+12 C→8 Beg.s. +16 Og.s.
reaction with experimental data.1) The calculation well
reproduces the resonance structures, particularly inhigher excitation energies. The characteristic enhancement at 90 degrees in the angular distributions (inset)
at Ec.m. = 32.5 and 28.7 MeV on-resonance energy (indicated by arrows) is also well reproduced. Figure 2
shows the same cross section (solid line) as that shown
on Fig. 1 divided into contributions from individual
reaction paths. It is observed that the channels withan (α–α)+(α–12 C)-type four-cluster structure have adominant contribution in reproducing the resonancestructures, and by further analysis, it is found thatthe peak at Ec.m. = 32.5 MeV is attributed to the fourcluster resonance state produced in the 8 Be+16 O in-

Fig. 2. Contribution from each transfer process. The solid
curve is the same as that in Fig. 1.

elastic scattering. These results strongly suggest that(α–α)+(α–12 C)-type four-cluster resonance structures
are produced in this α-transfer reaction.
We also investigate the rotational band formed in the
final 8 Be+16 O system. The result is shown in Fig. 3.
We observe many resonance states with three-cluster(open circles) and four-cluster structures (solid circles),although most of them cannot be observed clearly in
Fig. 1. The resonance peaks at Ec.m. = 32.5 MeV and
28.7 MeV in the α-transfer reaction (Fig. 1) are found
to reflect the resonances indicated by arrows in Fig. 3.

Fig. 3. Rotational band of the 8 Be+16 O system.

References
Fig. 1. Excitation function of the 12 C + 12 C → 8 Beg.s. +16
Og.s. α-transfer reaction, and angular distributions(inset) at the energies indicated by arrows.
∗1∗2

Institute of Physics, Tsukuba University
Department of Physics, Osaka City University

1) A. H. Wuosmaa et al.: Phys. Rev. Lett. 68, 1295 (1992);
R. A. Le Marechal et al.: Phys. Rev. C 55, 1881 (1997);
M. Aliotta et al.: Z. Phys. A 354, 119 (1996).
2) M. Kamimura: Nucl. Phys. A 351, 456 (1981); S.
Okabe: unpublished; M. Takashina: Ph. D. Thesis,
Osaka City University (2003).

15

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀect of halo structure on 11 Be+12 C elastic scattering
M. Takashina and Y. Sakuragi∗[NUCLEAR REACTION, Unstable nuclei]
Nuclear reactions involving neutron-rich nuclei havebeen important subjects in nuclear physics. Particularly, in light halo-nucleus-induced reactions, it is very
interesting to study how the halo structure aﬀects thereaction mechanisms. In the present study, we analyze the typical one-neutron halo nucleus 11 Be elastic
scattering on 12 C at E/A = 49.3 MeV.
Because of the weakly bound feature, the breakup
process of the incident halo nucleus 11 Be into 10 Be+n
is expected to be important. To describe its dynamical breakup eﬀect accurately, one needs to treat the11
Be+12 C scattering as, at least, a three-body problem. Therefore, we apply the continuum-discretizedcoupled-channels (CDCC) method,1) which is one ofthe practical and reliable methods for studying thethree-body reaction process.
In the CDCC method, the continuum-energy twobody breakup states of the projectile nucleus are approximately represented in terms of a ﬁnite number of
discretized states in the prescription called the methodof momentum bins. The discretized breakup states
can be treated in the same manner as conventional
discrete-excited states, and coupled-channel equations
are numerically solved in the standard manner to obtain the transition matrix elements for elastic scattering and breakup reactions.
The result of the CDCC calculation is shown in
Ref. 2, and is found to reproduce well the experimental data. The results of further investigation2) indicatethat the breakup eﬀect is dominated by the coupling
to the p- and d-wave breakup states. Among the pwave breakup states, the second bin (Êx = 0.954 MeV,
where Êx represents the mean energy of the bin) has
the largest contribution, while in the d-wave, the bin
containing the resonance state at Ex = 1.778 MeV has
the largest contribution. The large eﬀect of resonancebreakup can be understood from the good overlappingof localized-resonance wave function with the groundstate one. However, the overlap integral of the continuum wave function with the ground state one is not solarge.
To clarify the reason why the second bin of the pwave continuum breakup state has a large contribution, we investigate the coupling potential. First, we
λ=1(r, R) as
deﬁne a function Fp2,gs
λ=1
Fp2,gs(r, R) = Φp2 (r) V1 (r, R) Φgs (r),(1)

where V1 (r, R) represents the potential between core
(10 Be) and target (c-T), or that between neutron and∗

16

Department of Physics, Osaka City University

target (n-T) with multipolarity λ = 1. r and R represent the separation between core and neutron, andthat between the center-of-mass of 11 Be and target nucleus, respectively. Φα (r) is the 10 Be+n wave function
λ=1(r, R) over r and summingin state α. Integrating Fp2,gs
the c-T and n-T components, we obtain the coupling
potential between the ground state and the second binof p-wave continuum state as a function of R.
λ=2(r, R) as a function of r. R
Figure 1 shows Fp2,gs
is ﬁxed at 5.0 fm. It is found that the c-T component represented by a solid curve has a large amplitude in the long-range region, while the n-T components represented by the dotted curve is localized in
the short-range region. Since these two components
are summed when calculating the coupling potential,
the short-range parts cancel each other. However, thelong-range part of the c-T component survives, resulting in comparable magnitude of coupling potential
with the d-wave resonance breakup. This large amplitude of the c-T component is due to the long-range
tail of the valence neutron wave function of the groundstate. Namely, the large contribution from the p-wave
breakup state is a notable property characteristic of
the halo-nucleus-induced reaction.

λ=1
Fig. 1. Fp2,gs(r, R) defined in Eq. (1) as a function of theseparation r between neutron and core nucleus. R represents the separation between the center-of-mass of
11
Be and target nucleus, and is fixed at 5.0 fm. The
solid and dotted curves represent the core-target (c-T)
and neutron-target (n-T) components, respectively.

References
1) Y. Sakuragi, M. Yahiro, and M. Kamimura: Prog.
Theor. Phys. Suppl. 89, 136 (1986).
2) M. Takashina, S. Takagi, Y. Sakuragi, and Y. Iseri:
Phys. Rev. C 67, 037601 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

A search for a uniﬁed eﬀective interaction for Monte Carlo shellmodel calculations (V)M. Honma,∗1 T. Otsuka,∗2,∗3 B. A. Brown,∗4 and T. Mizusaki∗5[Shell model, Eﬀective interaction]
The Monte Carlo shell model (MCSM)1) has enabled us to study various nuclear structure in a hugeshell-model space. For this purpose, we have developed an eﬀective interaction GXPF12,3) for the fullpf -shell calculations. We have tested GXPF1 in detail from various viewpoints such as binding energies,
electro-magnetic moments and transitions, and excitation spectra. The semi-magic structure has beensuccessfully described for N or Z = 28 nuclei, suggesting the existence of signiﬁcant core-excitations in
low-lying non-yrast states as well as in high-spin yrast
states. The results of N = Z odd-odd nuclei havealso conﬁrmed the reliability of GXPF1 in the isospin
dependent properties.
In this report, as an example, we show the resultsfor 56 Ni. Most of shell-model calculations were carriedout in a conventional way by using the shell-model code
MSHELL,4) which enables calculations with M -scheme
dimensions of up to ∼ 108 on recent powerful computers. We can handle essentially all low-lying states in
the pf -shell nuclei with a minimal truncation of themodel space. We took t = 7 truncated subspace, where
the truncation order t denotes the maximum numberof nucleons which are allowed to be excited from thef7/2 orbit to higher three orbits p3/2 , f5/2 and p1/2 .
The agreement between the experiment and the calculation is rather good. The results are consistent withthose of MCSM shown in Fig. 2 of Ref. 2, conﬁrming
the reliability of the MCSM calculations.
GXPF1 predicts2) the deformed 4p-4h band5) as 0+
3,+
22 , · · ·. Special care should be taken concerning theconvergence of the calculation for such a deformed 4p4h band, since the present truncation scheme is obviously not suitable for describing strongly deformed
states, as discussed in Ref. 6 for the case of the FPD67)
interaction. Figure 1 shows the calculated energies andquadrupole moments of the lowest two 2+ states as afunction of the truncation order t. It can be seen thatthe 4p-4h state 2+
2 is not completely converged evenin the t = 7 subspace, which corresponds to the M scheme dimension of 89285264. In the same ﬁgure, the
MCSM results are also shown, where 25 bases weresearched for each eigenstate. The MCSM energy of
∗1
∗2
∗3
∗4

∗5

Center for Mathematical Sciences, University of Aizu
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, USA
Institute of Natural Sciences, Senshu University

Fig. 1. Convergence of the calculated energies (lower panel)and quadrupole moments (upper panel) as functions of
the truncation order t for the lowest two 2+ states of56
Ni. Horizontal lines show the corresponding MCSM
results.

the yrast 2+ state is almost the same as that of thet = 7 calculation, which shows reasonable convergence.
On the other hand, for 2+
2 states, the MCSM energy
is lower than the t = 7 result by about 0.2 MeV, andshould be more accurate. The electric quadrupole mo2
ment is Q(2+2 ) = −41.2 efm in the MCSM calculation,
while it is −33.6 in the present t = 7 result. Similar
results are obtained for the 4p-4h 0+
3 state. Thus, forthe description of such deformed states where a lot of
mixing among various spherical conﬁgurations occurs,
the MCSM calculation is more eﬃcient and suitable,
because certain basis states can be sampled from andaround local minima.
References
1) T. Otsuka et al.: Phys. Rev. Lett. 81, 1588 (1998).
2) M. Honma et al.: Phys. Rev. C 65, 061301(R) (2002).
3) M. Honma et al.: RIKEN Accel. Prog. Rep. 33, 16(2000); RIKEN Accel. Prog. Rep. 34, 15 (2001); RIKEN
Accel. Prog. Rep. 35, 12 (2002); RIKEN Accel. Prog.
Rep. 36, 21 (2003).
4) T. Mizusaki: RIKEN Accel. Prog. Rep. 33, 14 (2000).
5) D. Rudolph et al.: Phys. Rev. Lett. 82, 3763 (1999).
6) T. Mizusaki et al.: Nucl. Phys. A 704, 190c (2002).
7) W. A. Richter et al.: Nucl. Phys. A 523, 325 (1991).

17

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Ground states in even-even nuclei using random interactions
N. Shimizu and T. Otsuka∗1,∗2[Nuclear Shell Model, Quantum Chaos]
The random matrix theory has been investigatedto study the quantum chaos and nuclear physics, theobject of which is the quantum many-body system.
In the 1950s, Wigner introduced the random Hamiltonian matrix, whose elements are random numbers
obeying a Gaussian distribution in order to describe
the level distribution of highly excited nuclear states.1)
The level distribution had been the main topic of therandom matrix theory, until Johnson et al. discovered
the “J = 0 dominance” of the ground state provided
by a random Hamiltonian matrix.2)
The J = 0 dominance means that the angular momentum, J, of the ground state of even-even nuclei
obtained by a random Hamiltonian matrix favors zero,
although the subspace having J = 0 is very small incomparison with the entire Hilbert space. All the realistic even-even nuclei are known to have J = 0 groundstates experimentally, and the origin of the J = 0 dominance is considered to be the pairing correlation andtime reversal symmetry. However, the random interaction without time reversal symmetry was shown toreproduce the J = 0 dominance,3) and its investigation is still of interest. We discuss some properties of
the J = 0 dominance in this report.
Table 1 shows the ground state probability of the
sd-shell nuclei with N valence particles having angularmomentum zero (P (J = 0)). The Hamiltonian is taken

Table 1. Probability that the angular momentum ofground states will be zero (middle row) as comparedto the ratio of the dimension of the J = 0 subspace tothat of the entire Hilbert space (lower row). The system
consists of N identical particles in the sd-shell. The sdshell consists of 1d3/2 , 1d5/2 , and 2s1/2 . The probabilities are obtained by 1000 runs of TBRE Hamiltonians.
N
P (J = 0)
model space

∗1
∗2

18

2
14.0%
21.4%

4
56.6%
11.1%

6
71.3%
9.9%

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

as the two-body random ensemble, or TBRE.2) P (J =0) increases markedly with increasing N , while the J =0 ratio of all states decreases. P (J = 0) generally
increases with increasing dimension of the entire model
space, while the ratio of the J = 0 subspace decreases.
Then, P (J = 0) of a half-filled system tends to be thehighest probability.
Table 2 shows the P (J = 0) and the ratio of theJ = 0 subspace of pf -shell nuclei. Whereas they show
a similar behavior to sd-shell nuclei for the values of
N = 0, 2, 4, 6, and 8, the P (J = 0) of N = 10 suddenly
decreases. This is mainly caused by the f7/2 single
particle orbit, which does not favor the J = 0 groundstate. For example, P (J = 0) of N = 4 in f7/2 is17.7%, which is far smaller than those of other single-jshell systems.4) The occupation probability of the f7/2
orbit of the N = 10 system is larger than that of theN = 8 system, thus the P (J = 0) of N = 10 is suppressed. The result that the pf -shell without f7/2 does
not show such suppression supports this consideration.
This study is part of the RIKEN-CNS collaboration
project on large-scale nuclear structure calculation.
Table 2. Same as Table 1 except that this is for the pf shell. The pf -shell consists of 1f7/2 , 1f5/2 , 2p1/2 and2p3/2 .
NP (J = 0)
model space

2
11.3%
13.3%

4
42.6%
5.0%

6
55.7%
3.5%

8
60.3%
2.9%

10
50.6%
2.7%

References
1) E. P. Wigner: Ann. Math. 67, 325 (1958).
2) C. W. Johnson, G. F. Bertsch, and D. J. Dean: Phys.
Rev. Lett. 80, 2749 (1998).
3) R. Bijker, A. Frank, and S. Pittel: Phys. Rev. C 60,
021302 (1999).
4) Y. M. Zhao and A. Arima: Phys. Rev. C 64, 041301(2001).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Triaxiality of neutron-rich Mg isotopes
Y. Utsuno,∗1 T. Otsuka,∗2,∗3 T. Mizusaki,∗4 and M. Honma∗5[NUCLEAR STRUCTURE, Shell model, Unstable nuclei]
Owing to recent experiments of in-beam γ-ray spectroscopy for neutron-rich Mg isotopes 32,34 Mg,1,2) the
structure of these nuclei can be discussed in more detail apart from the disappearance of the N = 20 magic
structure. Although both of them are regarded as welldeformed nuclei from the measured low 2+
1 energy lev+
)
to
E
(2
)
are
ratherdiﬀerent,
els, the ratios of Ex (4+x1
1i.e., 2.6 and 3.2 for 32,34 Mg, respectively.1,2) The latteris very close to the value of the rigid axially symmetricrotor, whereas the former is not. In this study, we investigate how this diﬀerence occurs by large-scale shellmodel calculation using the Monte Carlo shell model(MCSM). The numerical computations have been carried out with the Alphleet and Alphleet-2 parallel computer systems as a RIKEN-CNS collaboration projecton large-scale nuclear structure calculation.
The shell-model Hamiltonian used in this study isthe same as that of our previous works.3) Figure 1
compares the energy levels and B(E2) values between
the experiment and MCSM. The observed diﬀerence

Fig. 1. Experimental energy levels and B(E2) values of32,34
Mg (Exp.) compared with those of the MCSM calculation (MCSM). The numbers near the arrows denotethe B(E2) in e2 fm4 .
∗1
∗2
∗3
∗4
∗5

Japan Atomic Energy Research InstituteDepartment 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+
in Ex (4+1 )/Ex (21 ) is well reproduced, similarly to theexcitation energies and the B(E2) values. We also calculate the non-yrast states, and ﬁnd a diﬀerence be32
Mg drops closely
tween those nuclei: the 2+
2 level of+to the 41 level, and is connected to the 2+
1 level witha moderately large B(E2) value.
In order to examine the deviation from the rigid
axially symmetric rotor, the potential energy surface(PES) is calculated within the shell-model space andusing the same Hamiltonian as illustrated in Fig. 2.
The PES of 32 Mg is more γ unstable than that of34
Mg, and after the angular-momentum projection, theenergy minimum moves to γ ∼ 20◦ . This γ value accounts for the shell-model result in Fig. 1, comparing
to the asymmetric rigid rotor model. On the other
hand, 34 Mg appears to be a rather good symmetricrotor. The present result demonstrates that our shellmodel calculation is capable of describing not only theshell structure but also the deformation giving rise to
more detailed properties.

Fig. 2. Comparison of the potential energy surfaces of32,34
Mg (a) without and (b) with the angular momentum projection onto I = 0. The thin and thick lines are
drawn at intervals of 0.3 and 1.5 MeV, respectively.

References
1) K. Yoneda et al.: Phys. Lett. B 499, 233 (2001).
2) F. Azaiez et al.: AIP Conf. Proc. 481, 243 (1998).
3) Y. Utsuno, T. Otsuka, T. Mizusaki, and M. Honma:
Phys. Rev. C 60, 054315 (1999); Phys. Rev. C 64,
011301(R) (2001).

19

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RIKEN Accel. Prog. Rep. 37 (2004)

Charge- and parity-projected Hartree-Fock method for strong tensor
correlation and its application to the alpha particle
S. Sugimoto, K. Ikeda, and H. Toki∗

NUCLEAR STRUCTURE, Mean field model, 4 He
We propose a mean-field framework in which the
charge and the parity symmetries of single-particle
states are broken. We break these symmetries to incorporate the correlation induced by the tensor force into
the nuclear mean field. The tensor force is mediatedby the pion. Recently, we proposed a new method oftreating the pion in the relativistic mean field (RMF)
theory by breaking the parity symmetry of the nuclear
mean field.1) In the previous paper,1) we applied thisidea to the RMF theory and showed that the correlation induced by the pion is obtained by this method.
Because the pion is an isovector meson, a singleparticle state in the mean field changes its charge state
when it emits or absorbs a charged pion. This feature indicates that the isovector nature of the pion canbe treated by introducing charge-mixed single-particle
states. The dominant part of the tensor force is ofthe τ 1 · τ 2 -type, and therefore, the charge mixing isimportant when we treat the tensor force in a nuclear
mean-field model.
The total wave function consisting of charge- andparity-mixed single-particle states does not have a definite parity and charge number, and therefore, thecharge and parity projections need to be performed.
For an A-nucleon system, we assume the total wave
function to be a Slater determinant of A particles. We
perform the charge and the parity projections on the
charge- and parity-mixed total wave function and takethe variation of each single-particle state. As a result,the charge- and parity-projected Hartree-Fock (CPPHF) equation, which is a Hartree-Fock-like equation,for each single-particle state is obtained. We solve it
self-consistently.
We show the results for the alpha particle in Table 1.
We take as the nucleon-nucleon potential the Volkov
No. 1 force2) for the central part, and the G3RS force3)
for the noncentral part. Here, we reduce the attractive
part of the Volkov No. 1 force in the 3 E channel bymultiplying it by the factor xTE . We also multiply
the τ1 · τ2 part of the tensor force by the factor xT .
The factors, xTE and xT , are determined to reproduce
the binding energy of the alpha particle in the CPPHF method. In the table, we show three cases. The
first one is the result of the simple Hartree-Fock (HF)
method, the second one is that of the parity-projected
Hartree-Fock (PPHF) method, and the third one isthat of the charge- and parity-projected Hartree-Fock(CPPHF) method. In the PPHF case, only the parity∗

20

Research Center for Nuclear Physics, Osaka University

Table 1. Results for the 0+ state of the alpha particle
for various cases. The potential energy (v̂(+;2) ),the kinetic energy (T̂ (+;2) ), and the total energy(E (+;2) ) are given. v̂C (+;2) , v̂T (+;2) , v̂LS (+;2) , andv̂Coul (+;2) are the expectation values for the central,tensor, LS, and Coulomb potentials, respectively.
xT
xTE

HF
1.0
1.0

HF
1.5
0.81

PPHF CPPHF
1.5
1.5
0.81
0.81

v̂C (+;2) (MeV)−76.67 −56.85 −61.31
0.00
0.00 −10.91
v̂T (+;2) (MeV)
0.00
0.00
0.67
v̂LS (+;2) (MeV)
0.83
0.76
0.78
v̂Coul (+;2) (MeV)−75.84 −56.10 −70.76
v̂(+;2) (MeV)
48.54
39.98
49.67
T̂ (+;2) (MeV)−27.30 −16.12 −21.09
E (+;2) (MeV)−64.75−30.591.91
0.85−92.5864.39−28.19projection is performed, but in the CPPHF case, boththe charge and the parity projections are performed. In
the simple HF case, the expectation value of the tensor
force becomes zero. However, in the PPHF case, thetensor correlation becomes finite. If we perform thecharge projection further, we can obtain much more
attractive energy from the tensor force. The energy
from the tensor force in the CPPHF case is about threetimes larger than that in the PPHF case. In the PPHF
case, only the τ0 τ0 part of the tensor force is active, but
in the CPPHF case, all the τ+ τ− , τ− τ+ , and τ0 τ0 termsof the tensor force can contribute to the nuclear mean
field.
From these results, we can see that, by combining
the mixing of parities and charges and the projections,
we are able to treat the tensor force in a mean-field
framework. Here, we note that the projections need tobe performed before the variation, because even if we
assume the charge and the parity mixings in the simple HF method, we do not obtain a charge- and paritymixed wave function as a result of a self-consistent calculation.
We are now trying to apply our method to heavier
systems and we can show the result in the near future.
References
1) H. Toki, S. Sugimoto, and K. Ikeda: Prog. Theor. Phys.
108, 903 (2002).
2) A.B. Volkov: Nucl. Phys. 74, 33 (1965).
3) R. Tamagaki: Prog. Theor. Phys. 39, 91 (1968).

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RIKEN Accel. Prog. Rep. 37 (2004)

Chiral sigma model with pion mean field in finite nuclei†
Y. Ogawa,∗1 H. Toki, S. Tamenaga,∗1 H. Shen,∗2 A. Hosaka,∗1 S. Sugimoto, and K. Ikeda

Chiral symmetry, Linear sigma model, Finite pion mean ﬁeld, Relativistic mean ﬁeld theory,
Magic number, Extended chiral sigma model

A theoretical framework to treat explicitly the pionmean ﬁeld in ﬁnite nuclei has been developed by introducing parity mixed intrinsic single particle states.1)
The purpose of this study is to investigate the properties of ﬁnite nuclei and the role of the pion using a chiral sigma model within the relativistic mean ﬁeld theory. Chiral symmetry is known to be the most important symmetry in hadron physics, which is described
well in a linear sigma model.2) The pion, which wasintroduced by Yukawa as the mediator of the nuclear
force,3) received its foundation through spontaneouschiral symmetry breaking.4) We then attempted to understand the nuclei based on the fundamental symmetry in hadron physics. We reconstructed an extendedchiral sigma (ECS) model Lagrangian in non-linear
realization, in which the nucleon and omega meson
masses are generated dynamically by sigma condensation in vacuum.5) All the parameters of the chiralsigma model are essentially ﬁxed from hadron properties in free space.
This model gives good saturation properties, which
are the density ρ = 0.141 fm−3 and the energy per
particle E/A = −16.1 MeV. The incompressibility inthis case, however, is determined to be very large,
K = 650 MeV. Furthermore, both scalar and vector potentials, which are related to the strength ofspin-orbit interaction, are approximately one-half ofthe phenomenological6) ones.
We have applied this model to ﬁnite nuclei (N = Z
even-even mass from N = 16 up to 34). We have
solved the coupled equations for nucleon and mesons
by iterative calculations.1) The ECS model without thepion mean ﬁeld indicates that the magic number appears at N = 18 instead of N = 20. This is due tothe large incompressibility in the nuclear matter. This
property leads to the 1s-orbit pushed up anomalously.
We note that this problem originates from the ECS
model treated in the present framework. We expect toeliminate this problem in our future work.
Another result obtained is that the magic number
does not appear at N = 28. This is due to anothercharacteristic property of this model, which leads tothe small spin-orbit interaction. Energy splittings between spin-orbit partners are small and have a negligible role in producing the magic eﬀect at N = 28.
†∗1∗2

On the basis of this point, it is very important to introduce the pion mean ﬁeld. Pionic correlations dueto the ﬁnite pion mean ﬁeld are expressed by coherent
0− particle-hole excitations,1) by which the coupling of
diﬀerent parity levels, l and l = l ± 1, with the same
total spin j in the shell model language is induced. In
this mechanism, only the highest j spin level does notﬁnd a partner in lower major shells. Once nucleons
start to occupy this level, these nucleons are able toﬁnd partners in higher major shells. The highest spinlevel is f7/2 in this mass region and the nucleons inthis level are used for the 0− particle-hole excitations
into g7/2 . The number of particles to be used in thepionic correlation increases as the nucleon number inthe f7/2 level increases until 56 Ni, where the f7/2 stateis completely occupied. For the nuclei above 56 Ni, theupper shells of f5/2 are to be occupied and those states
are not used from the d5/2 state due to Pauli blocking. Hence, the pionic correlation becomes maximum
at 56 Ni. This is the reason why 56 Ni obtains the largest
pionic correlation energy, which leads to the appearance of the magic eﬀect at N = 28. Due to the pioniccorrelation, parity partners, (s1/2 and p1/2 ), (p3/2 andd3/2 ) and (d5/2 and f5/2 ), are pushed out, and consequently, spin-orbit partners are split largely similar to
those of ordinary spin-orbit splittings.
The chiral sigma model determines the nuclear property with only a small adjustment of the parametersin the Lagrangian. The energy splitting between spinorbit partners is caused by the pionic correlation whichis completely a diﬀerent mechanism from the case of
the spin-orbit interaction introduced phenomenologically.
References
1) H. Toki, S. Sugimoto, and K. Ikeda: Prog. Theor. Phys.
108, 903 (2002).
2) M. Gell-Mann and M. Levy: Nuovo Cimento 16, 705(1960).
3) H. Yukawa: Proc. Phys.-Math. Soc. Jpn. 17, 48 (1935).
4) Y. Nambu and G. Jona-Lasinio: Phys. Rev. 122, 345(1961); Phys. Rev. 124, 246 (1961).
5) J. Boguta: Phys. Lett. B 120, 34 (1983); Phys. Lett. B
128, 19 (1983).
6) Y. Sugahara and H. Toki: Nucl. Phys. A 579, 557(1994).

Condensed from the article in Prog. Theor. Phys. 111, 75(2004).
Research Center for Nuclear Physics, Osaka University
Department of Physics, Nankai University, China

21

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Accurate calculations for few-nucleon systems using
low-momentum interactions
S. Fujii,∗1 H. Kamada,∗2 R. Okamoto,∗2 and K. Suzuki∗2[Low-momentum interaction, G matrix, Faddeev equation]
One of the fundamental objectives in nuclear structure calculations is to describe nuclear properties,
starting with realistic nucleon-nucleon interactions.
Since this kind of interaction has a repulsive core ata short distance, one has been forced to derive an effective interaction or G matrix in a model space for anucleus from the realistic interaction, except for precise few-nucleon structure calculations.
Recently, Bogner et al. has proposed a lowmomentum interaction which is constructed in momentum space for a two-nucleon system from a realistic nucleon-nucleon interaction, using conventionaleﬀective interaction theory or a renormalization group
technique.1) They have shown that the low-momentum
interaction conserves the properties of the original interaction, such as the half-on-shell T matrix and thephase shift within a cutoﬀ momentum Λ which limits the low-momentum region. The low-momentum
interactions for the typical Λ = 2.1 fm−1 corresponding to Elab  350 MeV are almost the same and are
not dependent on the realistic interactions employed.
Thus, as a unique low-momentum interaction, the lowmomentum interaction at approximately Λ = 2.1 fm−1
has been employed directly in nuclear structure calculations, such as the shell-model and Hartree-Fockcalculations. The calculated results are similar to thecase of the G matrix taking account of the short-range
correlation, Pauli-blocking eﬀect, and the state dependence for each nucleus.
Since the low-momentum interaction can be commonly used in various structure calculations in contrast
to the G matrix case, there has been increasing application of the low-momentum interaction. However,
Bogner et al.’s results of structure calculations using
the low-momentum interaction show the dependence
on the cutoﬀ momentum at around Λ = 2.1 fm−1 .
One of the central aims of the present work is toinvestigate the Λ dependence in structure calculations
for few-nucleon systems for which precise calculations
can be performed, and conﬁrm the validity of the lowmomentum interaction in the structure calculation bycomparing the obtained results with exact values. Asan accurate method for the structure calculation, we
use the Faddeev and Yakubovsky equations.

∗1
∗2

22

Department of Physics, University of Tokyo
Department of Physics, Kyushu Institute of Technology

In Fig. 1, the dependence of the calculated groundstate energies of 3 H on the cutoﬀ momentum Λ isshown as one of the calculated results. The lowmomentum interaction for each Λ constructed from the
CD-Bonn potential is employed in the Faddeev calculation. For simplicity, only the np interaction is used for
all the channels, and the S-wave approximation is employed. The result for “exact line” denotes the exact
solution for the Faddeev equation under the above assumptions. We see that the calculated result of approximately Λ = 2.1 fm−1 proposed by Bogner et al.
cannot reproduce the exact value. In order to reachthe exact value within an accuracy of 50 keV, we needvalues larger than Λ  5 fm−1 . More detailed results
concerning the validity of the low-momentum interaction will be reported in a separate paper.2)

Fig. 1. Dependence of calculated ground-state energies of3
H on the cutoﬀ momentum Λ for the CD-Bonn potential, exact line: the exact solution for the Faddeev
equation.

References
1) S. K. Bogner, T. T. S. Kuo, and A. Schwenk: Phys.
Rep. 386, 1 (2003).
2) S. Fujii, E. Epelbaum, R. Okamoto, K. Suzuki, H.
Kamada, and W. Glöckle: in preparation.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Shell structure in nuclei around 16 O and 24 O described using modern
nucleon-nucleon interactions
S. Fujii,∗1 R. Okamoto,∗2 and K. Suzuki∗2[Shell structure, Single-particle level, Eﬀective interaction]
The shell structure which is closely related to thesingle-particle level is one of the fundamental properties in nuclei. When we calculate the energies ofsingle-particle levels in neutron- or proton-rich nuclei,
it would be desirable that the calculation formalism
is based on the particle basis. The advantages of theparticle-basis formalism are that the Coulomb force
can be treated accurately for the proton-proton channel and eﬀects of charge dependence of realistic nuclear
forces are taken into account in structure calculations.
In the particle-basis formalism, one can obtain the energy diﬀerences between proton and neutron levels for
not only N  Z nuclei but also neutron- or proton-richnuclei in the same manner.
As one of the methods for solving nuclear manybody problems, we have developed the unitary-modeloperator approach (UMOA). Recently, we have extended the formulation of the UMOA from the isospin
basis to the particle one,1) and applied it to the calculations of binding energies and single-particle energies
in nuclei near the N = Z nucleus 16 O and the neutronrich nucleus 24 O.
We have employed modern nucleon-nucleon interactions such as the CD-Bonn potential based on
the meson-exchange model which have high accuracy to reproduce nucleon-nucleon scattering data anddeuteron properties. In addition, we have also used
the next-to-next-to-next-to-leading order (N3 LO) potential based on chiral perturbation theory which has
recently been constructed by Entem and Machleidt.2)
Although nucleon-nucleon interactions based on chiralperturbation theory are deﬁned essentially in a lowmomentum region compared with the meson-exchange
potentials, the N3 LO potential can accurately reproduce the nucleon-nucleon data below Elab  300 MeV.
Therefore, the N3 LO potential as well as other highprecision nucleon-nucleon interactions can be used innuclear structure calculations.
In Fig. 1, the calculated results of single-particle energies for the ground states of 17 O, 23 O, and 25 O using
the CD-Bonn potential are illustrated. The results areshown separately for the cases with and without thethree-body cluster (3BC) eﬀect which is one of thehigher-order many-body contributions to the single-∗1∗2

Fig. 1. Calculated single-particle energies for the groundstates of 17 O, 23 O, and 25 O with the CD-Bonn potential.

particle energy. The present study is the ﬁrst attempt
at clarifying the 3BC eﬀect on the single-particle energy in neutron-rich nuclei.
It can be seen that the 3BC eﬀect makes signiﬁcant repulsive contributions to the single-particle energies and increases as the mass number increases. The
strong repulsive eﬀect is favorable for the neutron-richnuclei 23 O and 25 O to reproduce the experimental values. On the contrary, the result for 17 O becomes worse
in comparison with the experimental value when the
3BC eﬀect is taken into account. We have conﬁrmedthat the results for the N3 LO potential show the sametendency as those for the CD-Bonn potential.
It is notable that a genuine three-body force is notincluded in the present calculation. The genuine threebody force would show attractive eﬀects on the singleparticle energies, and would have diﬀerent contributions between the N  Z and neutron-rich nuclei because of the isospin and density dependences. In orderto obtain deﬁnite conclusions, large-scale structure calculations are in progress.
References
1) S. Fujii, R. Okamoto, and K. Suzuki: nucl-th/0311053.
2) D. R. Entem and R. Machleidt: Phys. Rev. C 68,
041001 (2003).

Department of Physics, University of Tokyo
Department of Physics, Kyushu Institute of Technology

23

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Modified Hartree-Fock-Bogoliubov theory at finite temperature†
N. Dinh Dang and A. Arima[NUCLEAR STRUCTURE, Hartree-Fock-Bogoliubov theory, ﬁnite temperature]
This work has derived the modiﬁed Hartree-FockBogoliubov (MHFB) theory at ﬁnite temperature,
which conserves the unitarity relation of the generalized particle-density matrix. This has been doneby including the thermal ﬂuctuation of the quasiparticle number microscopically in the quasiparticledensity matrix. It has been shown that the latter
can also be obtained by applying the secondary Bogoliubov transformation discussed in Refs. 1 and 2.
The MHFB equations at ﬁnite temperature have beenthen derived following the standard variational procedure. Its Bardeen-Cooper-Schrieﬀer (BCS) limit
yields the modiﬁed BCS (MBCS) equations, whichhave been derived previously in Refs. 1 and 2 using
the above-mentioned secondary Bololiubov transformation. Apart from being able to restore the unitarity transformation, this secondary transformation
helps the modiﬁed quasiparticle random-phase approximation (QRPA) to completely restore the Ikeda sum
rule for Fermi and Gamow-Teller transitions, which has
been violated within the renormalized QRPA.
The illustration of the MHFB theory has been presented within the MBCS theory by calculating theneutron pairing gap and thermodynamic quantities for120
Sn. Detailed analyses of the results obtained showthat the calculations for open-shell nuclei within the
MBCS theory need to be carried out using the entire
single-particle spectrum, which includes both boundand quasibound levels in a large conﬁguration spaceof about 7 major shells up to 126–184 one. Whenthe use of a reduced spectrum is unavoidable, the reduction should be done symmetrically from both sideof the chemical potential µ̄ so that the distributionof quasiparticle-occupation number can be properly
taken into account as it is symmetric with respect toµ̄. The MBCS gap decreases monotonously with in-†24

Condensed from the article in Phys. Rev. C 68, 014318(2003)

creasing T and does not vanish even at T ∼ 5 MeV.
The discontinuity in the BCS heat capacity at thecritical temperature Tc is also competely washed out,
showing no signature of superﬂuid-normal phase transition. The temperature dependences of level density
and level-density parameter are also smooth.
The behavior of the MBCS gap as a function of T
is found in qualitative agreement with that given by
the macroscopic treatment using the Landau theoryof phase transitions in the sense that both gaps do
not collapse at the critical temperature of the BCS
superﬂuid-normal phase transition. However, quantitative discrepancies between microscopic and mascroscopic approaches are evident. In the low-temperature
region, due to the microscopic interplay between quantal and thermal components, the MBCS gap starts todecrease at a higher T with increasing T as comparedto the macroscopically averaged gap ∆. At high temperatures T > 2 MeV, the MBCS gap continues to decrease, while ∆ remains nearly constant and evenstart to increases with increasing T .
The MBCS equations also show that thermal ﬂuctuations can induce a pairing gap even for closed-shell
nuclei. Results obtained using a single-particle space
restricted to hole orbitals have shown that such a thermally induced gap increases with increasing temperature. However, its magnitude is negligible comparedwith the gap in open-shell nuclei. Therefore, it can besafely put to be equal to zero at T ≤ 5–6 MeV.
References
1) N. Dinh Dang and V. Zelevinsky: Phys. Rev. C 64,
064319 (2001).
2) N. Dinh Dang and A. Arima: Phys. Rev. C 67, 014304(2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Pairing eﬀect on the giant dipole resonance width
at low temperature†
N. Dinh Dang and A. Arima[NUCLEAR STRUCTURE, Hartree-Fock-Bogoliubov theory, ﬁnite temperature]
Intensive experimental studies of highly-excited nuclei during the last two decades have shown that thewidth of the giant dipole resonance (GDR) increases
sharply with increasing the temperature T from T >1 MeV up to  3 MeV. At higher T a width saturation
has been reported. The increase of the GDR widthwith T is described reasonably well within the thermal
shape-ﬂuctuation model1) and the phonon damping
model (PDM).2) The thermal shape-ﬂuctuation model
assumes an adiabatic coupling of GDR to quadrupole
degrees of freedom with deformation parameters β andγ induced by thermal ﬂuctuations and high spins in
the intrinsic frame of reference. The PDM considers
the coupling of the GDR to particle-particle and holehole conﬁgurations at T = 0 as the mechanism of thewidth increase and saturation. The PDM calculates
the GDR width and strength function directly in thelaboratory frame without any need for an explicit inclusion of thermal ﬂuctuation of shapes.
In general, pairing was neglected in the calculations
for hot GDR as it was believed that the gap vanishes
at T = Tc < 1 MeV according to the temperature
Bardeen-Cooper-Schrieﬀer (BCS) theory. However, it
has been shown in Ref. 3 that thermal ﬂuctuations
smear out the superﬂuid-normal phase transition in ﬁnite systems so that the pairing gap survives up toT  1 MeV. This has been conﬁrmed microscopicallyin the recent modiﬁed Hartree-Fock-Bogoliubov theory
at ﬁnite T ,4) whose limit is the modiﬁed-BCS theory.5)
Very recently the γ decays were measured in coincidence with 17 O particles scattered inelastically from120Sn.6) A GDR width of around 4 MeV has been extracted at T = 1 MeV, which is smaller than the valueof ∼ 4.9 MeV for the GDR width at T = 0. This result and the existing systematic for the GDR widthin 120 Sn up to T  2 MeV are signiﬁcantly lower thanthe prediction by the thermal shape-ﬂuctuation model.
Based on this, Ref. 6 concluded that the narrow widthobserved in 120 Sn at low T is not understood. The
aim of the present work is to show that it is thermal
pairing that causes the narrow GDR width in 120 Sn at
low T . For this purpose we include the thermal pairing
gap obtained from the modiﬁed-BCS theory4,5) in the
PDM,2) and carry out the calculations for the GDR
width in 120 Sn at T ≤ 5 MeV. In diﬀerence with thegap given within the conventional BCS theory, whichcollapses at Tc  0.79 MeV, the modiﬁed-BCS gap†

never vanishes, but monotonously decreases with increasing T up to T  5 MeV. The results obtained
show that thermal pairing indeed plays an importantrole in lowering the width at T ≤ 2 MeV as comparedto the value obtained without pairing. This improves
signiﬁcantly the overall agreement between theory andexperiment, including the width at T = 1 MeV extracted in the latest experiment6) (See Fig. 1).

Fig. 1. GDR width ΓGDR as functions of T for 120 Sn. The
thin and thick solid lines show the PDM results obtained without and including the thermal pairing gap,
respectively. Solid circles are the low-T data from
Ref. 6. The predictions by two versions of the thermal
shape-ﬂuctuation model1) are shown as the dash-dotted
and thin dotted lines.

References
1) W. E. Ormand, P. F. Bortignon, and R. A. Broglia:
Phys. Rev. Lett. 77, 607 (1966); W. E. Ormand et al.:Nucl. Phys. A 614, 217 (1997); D. Kusnezov, Y. Alhassid, and K.A. Snover: Phys. Rev. Lett. 81, 542 (1998).
2) N. D. Dang and A. Arima: Phys. Rev. Lett. 80, 4145
(1998); N. D. Dang and A. Arima: Nucl. Phys. A 636,
427 (1998).
3) L. G. Moretto: Phys. Lett. B 40, 1 (1972).
4) N. Dinh Dang and A. Arima: Phys. Rev. C 68, 014318(2003).
5) N. Dinh Dang and V. Zelevinsky: Phys. Rev. C 64,
064319 (2001); N. Dinh Dang and A. Arima: Phys. Rev.
C 67, 014304 (2003).
6) P. Heckman et al.: Phys. Lett. B 555, 43 (2003).

Condensed from the article in Phys. Rev. C 68, 044303(2003)

25

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RIKEN Accel. Prog. Rep. 37 (2004)

Three-dimensional rotation of even-even triaxial nuclei†
M. Oi∗ and P. M. Walker∗[NUCLEAR STRUCTURE, 3d-cranking model, Rapidly rotating nuclei]
Nuclei in the A  130 region are now of special
interest because it is suggested that a new form of
nuclear rotation can be expected: a chiral rotation.1)
This three-dimensional rotation was predicted at ﬁrst
in odd-odd systems, such as 134
59 Pr75 , whose total angular momentum is built by a particle and a hole invalence orbitals in addition to a triaxial rotor, under
an assumption of the irrotational-ﬂow moment of inertia. Their angular momentum vectors point along
the shortest (s), longest (l) and intermediate (i) axesof the triaxially deformed nucleus (γ  30◦ ),a) respectively. When the collective angular momentum
is absent, the total angular momentum consists onlyof the single-particle spins. The corresponding state iscalled “planar” because the total angular momentumis in the s − l plane. The planar states correspond to“bandheads” of the chiral rotational bands. Rotational
members built upon the planar state are classiﬁed as“aplanar” states because these states have the genuine
chiral conﬁguration. Possible experimental evidence ofthe nuclear chirality was reported in N = 75 odd-odd
isotones in the same mass region,2) through ﬁndingsof pairs of near-degenerate ∆I = 1 bands (so-called“chiral doublets”).
It is an interesting question whether or not even-evennuclei can have the chiral conﬁguration after breaking (Cooper) pairs. To realise the nuclear chirality ineven-even systems, at least four quasi-particles must
be excited; two neutrons and two protons. This multiquasiparticle excited state is expected at high spin
where rotation-alignment occurs due to the Coriolis
force. It is likely that such a “simultaneous” aligned
state would be seen at higher spin, compared withthe odd-odd chiral systems. Experimentally, a candidate for chiral doublets in even-even nuclei is suggested
3)
but there is as yet no detailed theoretiin 136
60 Nd76 ,cal analysis about the possibility of chiral solutions ineven-even nuclei, except a brief conference report.4)
The original model of the nuclear chirality is basedon the particle(hole)-plus-rotor model which admits
the presence of a macroscopic rotor with solid triaxial
deformation (γ  30◦ ). Although there is no conceptof a rotor in fully microscopic models like the HFBapproach, the rotor spin can be treated as the collective part of angular momentum in the cranking model,
which can handle the collective and single-particle angular momentum on the same footing. An analysis of
the chiral conﬁguration in odd-odd systems was carriedout through the Tilted-Axis Cranking model (TAC).1)
Although each microscopic calculation (TAC) is madefor given parameters of shape and pairing gaps as wellas rotational frequency, these parameters are carefully
determined by a macroscopic + microscopic approach(the Strutinski method) in terms of the energy minimisation.
If nuclear chirality is produced in even-even systems
by four or more quasiparticle excitations, where thequasiparticles occupy orbitals with very diﬀerent orientation, it is expected that the collective and individual (quasi-)particle motions would be strongly coupledthrough the Coriolis force. Besides, the degree of triaxial deformation can be susceptible to the inﬂuence
coming from rotation-alignments at high spin, especially in those nuclei whose Fermi level is in the upper
shell (i.e., high-Ω Nilsson orbits).5) Therefore, if we attempt to describe the above physical situations, purely
microscopic and self-consistent treatments should bemade with respect to nuclear shape and pairing. In
other words, for the aim of demonstrating the chirality
in even-even systems, it is necessary to show the emergence of a genuine three-dimensional rotation together
with the presence of substantial triaxial deformation.
Furthermore, compared to odd-odd systems, it is numerically advantageous for us to study even-even systems because the treatment of pairing is more straightforward.
In this work, we performed a fully microscopic andself-consistent study of three-dimensional nuclear rotations in even-even nuclei in the A  130 mass region
near the yrast line, by means of the three-dimensional
cranked Hartree-Fock-Bogoliubov method.6)
References
1) S. Frauendorf and J. Meng: Nucl. Phys. A 617, 131(1997); V. I. Dimitrov, S. Frauendorf, and F. Dönau:
Phys. Rev. Lett. 84, 5732 (2000).
2) K. Starosta et al.: Phys. Rev. Lett. 86, 971 (2001).
3) E. Mergel et al.: Eur. Phys. J. A 15, 417 (2002).
4) V. Dimitrov, F. Dönau, and S. Frauendorf: nucl-th/
0211063.
5) R. R. Hilton, H. J. Mang, and P. Ring: Phys. Rev. Lett.
43, 1979 (1979).
6) T. Horibata and N. Onishi: Nucl. Phys. A 596, 251(1996).
7) P. Ring and P. Schuck: in Nuclear Many-body Problem,
edited by W. Beiglbock et al. (Springer-Verlarg, Berlin,1980), p. 8.
a)

†
∗

26

Condensed from the article in Phys. Lett. B 576, 75 (2003)
Department of Physics, University of Surrey, UK

The Hill-Wheeler parameterization7) is employed for thequadrupole deformation parameters, β and γ, where the signof γ is opposite to the Lund convention.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Required accuracy of mass and half-life measurements planned atfuture RI-beam facilities to understand the r-process nucleosynthesis
Y. Motizuki, T. Tachibana,∗1 and S. Goriely∗2[Nucleosynthesis, Nuclear mass formulae, Unstable nuclei]
To understand the r-process nucleosynthesis, we estimate the required accuracy for mass and half-life
measurements planned at future RI-beam facilities, including the RI-Beam Factory. As a ﬁrst rough guidefor detector developments, we consider a simple requirement from a theoretical point of view as follows:
The mass and halﬂife measurements should distinguishphysical quantities predicted from semi-empirical andmicroscopic mass formulae, KUTY and HFB-2, respectively, within 3σ errors at the neutron-richest nucleus
on the r-process path at the N = 82 shell closure. The
above is the minimum requirement because r-process
studies would not beneﬁt if future experiments could
not tell what type of mass model is appropriate forabundance calculations.
The above two mass formulae were employed because they were derived from completely opposite leading principles: the KUTY mass formula1) has anempirical gross term for macroscopic properties andspherical-basis shell terms for microscopic propertiesof nuclear masses. Allowing many parameters to describe the single-particle potential and nuclear structure, the KUTY model aims at explaining the nuclear masses as well as the single-particle energy-levelstructure as much as possible. On the other hand,
HFB-2 masses2,3) were derived with the Hartree-FockBogoliubov method, aiming at explaining the nuclear
masses with a speciﬁc nuclear force and with much
fewer number of parameters. Both models attain agood root-mean-square deviation, ∼680 keV, from themeasured masses of 2135 nuclei at and close to thestability line. However, most importantly, they predict very diﬀerent masses and hence give very diﬀerent half-lives for nuclei relevant to the r-process whichhave not yet been measured.
To determine the polestar neutron-richest isotope
on the r-process path among N = 82 isotones, weapply an r-process path obtained under the so-called
waiting-point-approximation with the KUTY masses
and their half-lives calculated by the second version of
the gross theory.4,5) The r-process path, simulated witha temperature of 1.5 × 109 K and a neutron density of1024 cm−3 , determines the nuclide 123 Nb as the polestar
neutron-richest isotope. We note that the path mentioned above should be taken as a typical example.
We accordingly analyze the mass diﬀerence between∗1∗2

the KUTY and HFB-2 predictions for the N = 82
isotones up to 123 Nb. We conclude that the detectors
for the mass measurements must have an accuracy ofat least 1σ = 250 keV at the neutron richness of A/Z =3.0 to satisfy the above requirement. This is illustrated
in Fig. 1.
The half-lives can be calculated with various methods using a set of nuclear masses. We also analyze
the half-life diﬀerences derived from KUTY and HFB-2
masses and conclude that 1σ = 0.15 ms is the minimum
requirement for the half-life measurements at the neutron richness of A/Z = 3.0. Note that not only statistical but also systematic errors should be included in theabove discussion. Future measurements with smaller
errors than the obtained ones here are strongly encouraged in order to develop theories of nuclear masses andhalf-lives: By updating the parameter values includedin each model, the predictions would tend to be converged. This will highly beneﬁt r-process studies which
we do not know anything conclusive yet.

Fig. 1. Mass diﬀerence between the HFB-2 and KUTY predictions for N = 82 isotones.

References
1) H. Koura et al.: Nucl. Phys. A 674, 47 (2000).
2) S. Goriely et al.: Phys. Rev. C 66, 24326-1 (2002).
3) M. Samyn et al.: Nucl. Phys. A 700, 142 (2001).
4) T. Tachibana et al.: Prog. Theor. Phys. 84, 641 (1990).
5) T. Tachibana and M. Yamada: in Proc. Int. Conf. on
Exotic Nuclei and Atomic Masses, edited by M. de Saint
Simon et al. (Editions Frontieres, 1995), p. 763.

Senior High School of Waseda University
Institut d’Astronomie et d’Astrophysique, Universite Librede Bruxelles, Belgium

27

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Comparison of prolate and oblate explosions
in core-collapse supernovae
H. Madokoro, T. Shimizu, and Y. Motizuki[shock waves, hydrodynamics, stars: neutron, supernova: general]
Shimizu et al.1) studied the eﬀects of anisotropic
neutrino radiation on the mechanism of core-collapse
supernova explosions. They considered only the casein which the maximum value in the neutrino ﬂux distribution was located at the axis of symmetry (polaraxis). Janka and Keil,2) however, pointed out thatthe neutrino ﬂux can have its peak on the equatorial
plane. In this paper, we study the eﬀects of the oblate
neutrino heating on the explosion dynamics.
We solved hydrodynamical equations in the spherical coordinate (r, θ).1,3) The local neutrino ﬂux is assumed to be3)
 1
7
σTν4 c1 1 + c2 cos2 θ 2 ,lν (r, θ) =(1)
16r
where σ is the Stefen-Boltzmann constant, Tν =4.70 MeV is the temperature on the neutrinosphere,
and c2 is a parameter which is related to the degreeof anisotropy in the neutrino radiation. The value of
c1 is calculated from the given c2 in such a way thatthe total neutrino luminosity is adjusted to that of thespherical model at the same Tν . The ratio of the neutrino ﬂux along the polar axis (θ = 0◦ ), lz , to that on
the equatorial plane (θ = 90◦ ), lx , is represented bylz /lx = 1 + c2 .
We studied two models: the prolate model (pro100)
and the oblate model (obl091). The values of c2 forthese models are chosen in such a way that the value oflz /lx becomes 1.1 (c2 = +0.100) for the prolate modeland 1/1.1 = 0.909 (c2 = −0.091) for the oblate model.
Figure 1 shows the contour maps of the dimensionless entropy distribution with the velocity ﬁelds for thetwo models. Due to anisotropic neutrino heating, theshock front becomes prolate and largely distorted inmodel pro100, while it is elongated in an oblate shapein model obl091. The evolution of the explosion energy
is shown in Fig. 2. It is found that the energy gain inmodel pro100 is much larger than that in model obl091.
The diﬀerence between the two models is attributed
to the importance of the locally intense neutrino heating. In contrast to the prolate explosion, the neutrino radiation is anisotropic but its peak is not locatedpoint-like in the case of the oblate one; the heated region is distributed in a disk-like form over the equatorial plane. The eﬃciency of anisotropic neutrino heat-28

Fig. 1. Contour maps of the dimensionless entropy distribution and the velocity fields for two models, pro100(left) and obl091 (right) at t ∼ 280 ms.

Fig. 2. Evolution of the explosion energy for model pro100(solid line) and model obl091 (dashed line). The resultof the spherical explosion (dotted line) for the same Tν
is also shown for comparison.

ing for the oblate model is therefore considerably reduced, resulting in less energetic explosion. Our results
support the statement made by Shimizu et al.,1) thatis, locally intense neutrino heating is of great importance in producing a successful explosion.
References
1) T. M. Shimizu et al.: Astrophys. J. 552, 756 (2001).
2) H.-Th. Janka and W. Keil: Astro-ph/9709012 (1997).
3) H. Madokoro, T. Shimizu, and Y. Motizuki: Astrophys.
J. 592, 1035 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Properties of a relativistic equation of state
for collapse-driven supernovae
K. Sumiyoshi,∗1 H. Suzuki,∗2 S. Yamada,∗3 and H. Toki,∗4[Dense matter, Equation of state, Supernova]
Clarifying the mechanism of core-collapse supernova
explosion is fascinating. An important microphysics
ingredient for supernova simulations is the equationof state (EOS) of dense matter. It determines thestellar structure, the hydrodynamics and the reaction
rates through the determination of pressure, entropy
and chemical compositions. Recently, a new complete EOS for supernova simulations has become available.1,2) The relativistic mean ﬁeld (RMF) theory witha Thomas-Fermi approach has been applied to thederivation of the supernova EOS. The RMF theory
based on the RBHF theory has been successful for reproducing the masses and radii of unstable nuclei aswell as stable ones.3)
We study the characteristics of the relativistic EOS
in collapse-driven supernovae4) using the general relativistic hydrodynamics5) of the gravitational collapse
and bounce of supernova cores. In order to study dense
matter in a dynamical situation, we perform simpliﬁed
calculations of core collapse and bounce by following
adiabatic collapse with a ﬁxed electron fraction. We
investigate the proﬁles of thermodynamical quantities
and the compositions during collapse and bounce. We
also perform the calculations with the Lattimer-SwestyEOS6) to compare the properties of dense matter.
The compositions during collapse at the times (1)and (2) (central densities: 1011 and 1012 g/cm3 ) are
shown for the case of 15 M model of WW957) inFig. 1. It can be seen that the mass fractions are substantially diﬀerent between the relativistic EOS andthe Lattimer-Swesty EOS. The mass fractions of alpha particles and neutrons in the relativistic EOS arelarger than those in the Lattimer-Swesty EOS. The
free-proton fraction is almost one order of magnitude
smaller than that obtained with the Lattimer-Swesty
EOS. Having a smaller fraction of free protons is favorable for the explosion since electron capture is largely
reduced, leading to a stronger prompt shock.
The reduction in the free-proton fraction comes froman eﬀect of the large symmetry energy in the RMF theory, which is constrained by systematic measurementsof the masses and radii of neutron-rich nuclei. These
diﬀerences of compositions should be examined further in numerical simulations of hydrodynamics withneutrino transfer by switching the two sets of EOS to
∗1
∗2
∗3
∗4

Numazu College of Technology
Faculty of Science and Technology, Tokyo University of Science
School of Science and Engineering, Waseda University
Research Center for Nuclear Physics, Osaka University

Fig. 1. The mass fractions of protons, neutrons, nuclei andalpha particles are shown as functions of baryon mass
coordinates denoted by solid, dashed, dotted and dotdashed lines, respectively. The results obtained withthe relativistic EOS are shown by thick lines and theLattimer-Swesty EOS by thin lines.

examine the role of the nuclear interaction and EOS in
the mechanism of supernova explosions.
References
1) H. Shen, H. Toki, K. Oyamatsu, and K. Sumiyoshi:
Nucl. Phys. A 637, 435 (1998).
2) H. Shen, H. Toki, K. Oyamatsu, and K. Sumiyoshi:
Prog. Theor. Phys. 100, 1013 (1998).
3) Y. Sugahara and H. Toki: Nucl. Phys. A 579, 557(1994).
4) K. Sumiyoshi, H. Suzuki, S. Yamada, and H. Toki:
Nucl. Phys. A 730, 227 (2004).
5) S. Yamada: Astrophys. J. 475, 720 (1997).
6) F. D. Swesty, J. M. Lattimer, and E. S. Myra: Astrophys. J. 425, 195 (1994).
7) S. E. Woosley and T. Weaver: Astrophys. J. Suppl. Ser.
101, 181 (1995).

29

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RIKEN Accel. Prog. Rep. 37 (2004)

Proton-nucleus elastic scattering and the equation of stateof nuclear matter†
K. Iida, K. Oyamatsu,∗1 and B. Abu-Ibrahim∗2[Dense matter, Proton elastic scattering, Unstable nuclei]
We calculate diﬀerential cross sections for protonnucleus elastic scattering by using a Glauber theory
in the optical limit approximation and nucleon distributions that can be obtained in the framework ofmacroscopic nuclear models1) in a way dependent on
the equation of state of uniform nuclear matter near
the saturation density. These nuclear models reasonably reproduce empirical data for masses and radii ofstable nuclei and allow for uncertainties in the values ofthe symmetry energy density-derivative coeﬃcient, L,
and the incompressibility of symmetric nuclear matter,
K0 .
Figure 1 exhibits the results calculated for the angular distribution for proton elastic scattering oﬀ heavy
stable nuclei. We can see, from comparison with theFig. 1. Proton-nucleus elastic diﬀerential cross sections for58
Ni (Tp = 1047, 400 MeV), 124 Sn (Tp = 800 MeV)
and 208 Pb (Tp = 800 MeV). The solid, dotted, shortdashed, long-dashed and dot-dashed lines are the results
calculated for (L, K0 ) = (50, 230), (50, 180), (50, 360),(5, 230), (80, 230) in MeV. For comparison, we also plotted the results (thin lines) calculated from the Fermitype nucleon distributions derived in Ref. 2. The experimental data (dots) are taken from Refs. 2–4.
†
∗1
∗2

30

Condensed from the article in Phys. Lett. B 576, 273 (2003)
Department of Media Theories and Production, Aichi
Shukutoku University
Department of Physics, Cairo University, Egypt

empirical values, that the Glauber model is satisfactory for suﬃciently high proton incident energy, Tp ,and small scattering angle, θc.m. . We thus focus on
the angle and height of the ﬁrst scattering peak; thevalues calculated for Ni isotopes are plotted in Fig. 2.
We ﬁnd that the peak angle decreases with L more
remarkably for larger neutron excess, while the peakheight increases with K0 almost independently of neutron excess. We suggest the possibility that comparison of the calculations with experimental data for the
peak angle may be useful for determination of L.

Fig. 2. The angles and heights of the scattering peakin the small angle regime, calculated as functions of
L and K0 for p-58 Ni and p-80 Ni elastic scattering at
Tp = 800 MeV. The experimental angle and height including errors (from Ref. 2) are denoted by the horizontal lines (thick lines: central values, thin lines: upperand lower bounds).

References
1) K. Oyamatsu and K. Iida: Prog. Theor. Phys. 109, 631(2003).
2) L. Ray, W. Rory Coker, and G. W. Hoﬀmann: Phys.
Rev. C 18, 2641 (1978).
3) R. M. Lombard, G. D. Alkhazov, and O. A.
Domchenkov: Nucl. Phys. A 360, 233 (1981).
4) H. Sakaguchi et al.: Phys. Rev. C 57, 1749 (1998).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

A search for the eﬀect of nuclear outer surface
in proton-nucleus elastic scattering
A. Kohama[NUCLEAR REACTION, unstable nuclei]
The unstable nuclei on the neutron-rich side
(neutron-rich nuclei) are often characterized as thosewith a large surface region generated by loosely boundvalence nucleons. We have been focusing on the determination of the matter density distributions in thesurface and outer regions to clarify the feature. In
our previous work,1) we discussed how much we could
determine the nuclear matter density distributions ofneutron-rich nuclei from the proton elastic scatterings.
We demonstrated that the matter density distribution
in the surface region is determined well using relatively
low-intensity beams, such as 10 [1/s].1)
For an extension of the above work, we have discussed how the density distributions in the outer surface region aﬀect the diﬀerential cross section of the
proton-nucleus elastic scattering in this work. Thisconsideration would be useful for the analysis of nuclei
whose surface structure does not change considerably
when we approach the neutron drip line. This may
occur for medium-heavy nuclei, such as Ni or Sn.
We have applied the Glauber approximation with
the Coulomb interaction of the ﬁnite extension of thepoint-proton density distribution,2) and have concentrated on the observation of the behavior of the crosssection. Since the proton of small momentum transfer mostly probes the nuclear periphery, the eﬀect of
the outer surface is expected to appear in the forward
direction. We have mimicked the halo structure of
the neutron-rich nuclei, by artiﬁcially varying the oneneutron separation energy, Sn , from the original one,but kept the surface shape unchanged (Fig. 1). The
normalization is also kept ﬁxed.
In Fig. 2 one can see that in the forward direction
where the nuclear and the Coulomb interactions compete with each other, the cross section of the halolike
neutron density (the solid curve) oscillates around theone determined by the original Sn of 58 Ni (the dashedcurve), which is due to Coulomb-nuclear interference.
The smaller Sn becomes, the larger the eﬀect becomes,
although the net eﬀect is rather small. The precise
measurements in the forward direction, which could
be possible due to the large cross sections, will assist
the minute (model-independent) determination of thedensity distributions of the neutron-rich nuclei.

Fig. 2. Eﬀect of the outer surface of the neutron density
distribution on the proton-“mock” 58 Ni elastic scattering cross section in the linear scale. The curves correspond to those in Fig. 1. The dot-dashed and thedashed curves are very close to each other, and cannot
be identiﬁed separately by eye.
Fig. 1. Dependence of the neutron density distribution of
the “mock” 58 Ni on the variation of Sn . The dashedcurve is a linear combination of the two two-parameter
Fermi distributions (2pFs) with the asymptotic behavior determined by the Sn of the actual 58 Ni. The dotdashed curve is determined by 50% of the original Sn ,and the solid curve is by 10% of the same Sn . As a reference, the one 2 pF of the same surface shape is plottedby the dotted curve.

References
1) A. Kohama, R. Seki, A. Arima, and S. Yamaji: J. Phys.
Soc. Jpn. 72, 2766 (2003).
2) R. J. Glauber: in High-Energy Physics and Nuclear
Structure, edited by S. Devons (Plenum Press, New
York, 1970), p. 207.

31

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RIKEN Accel. Prog. Rep. 37 (2004)

The behavior of matter at high baryon density†
W. Bentz,∗1 T. Horikawa,∗1 N. Ishii, and A. W. Thomas∗2[MATTER AT HIGH DENSITY, Nuclear Matter, Quark Matter]
The possibility of a phase transition from nuclear
matter (NM) to quark matter (QM) at high baryon
densities is of great interest in connection with neutron stars and the possible existence of quark stars. In
recent works we have shown that one can consistently
describe the nucleon as a quark-scalar diquark boundstate,1) the equation of state (EOS) of nuclear matter(NM),2) and the transition to color superconducting
quark matter (QM)3) in the framework of the NambuJona-Lasinio model, which is an eﬀective quark theory
based on QCD.
The solution of the quark-diquark bound state equation gives nucleon mass MN (M ) as a function of constituent quark mass M . The eﬀective potential for
NM in the mean ﬁeld approximation has the form2)
V (N M ) = Vvac + VN + Vω , where Vvac denotes the polarization of the Dirac sea of quarks, VN arises fromthe Fermi motion of nucleons, and Vω is the contribution of the mean vector ﬁeld (ω0 ). M and ω0 are
determined so as to minimize V (N M ) . The eﬀects of
conﬁnement are simulated by introducing an infrared
cutoﬀ in the proper time regularization scheme, which
eliminates unphysical thresholds for the decay of thenucleon into quarks, which is very important for thestability of NM.
The eﬀective potential for QM in the mean ﬁeld approximation has the form3) V (QM ) = Vvac + VQ + V∆ ,where VQ denotes the Fermi motion of quarks, and V∆
arises from quark pairing and depends on the color
superconducting gap (∆). M and ∆ are determinedso as to minimize V (QM ) . As argued in Ref. 3, there
should be no mean vector ﬁeld in QM. Since QM corresponds to the deconﬁned phase, we do not introduce
an infrared cutoﬀ here.
Figure 1 shows the pressures for NM (solid line) andQM for several strengths of the pairing interaction (rs ).
Curve 1 corresponds to normal (non color superconducting) QM. It is clear from Fig. 1 that there is nophase transition from NM to normal QM in our model,
but the scalar diquark condensation softens the EOS
of QM and leads to a phase transition at a density
which depends on rs . In Fig. 2 we set rs = 0.2, andshow the pressure of the ground state as a function of
baryon density. We obtain ﬁrst-order transitions fromvacuum (VAC) to NM, where chiral symmetry is broken and color symmetry is intact, and from NM tocolor superconducting QM, where chiral symmetry is
†
∗1
∗2

32

Condensed from the article in Nucl. Phys. A 720, 95 (2003)
Department of Physics, Tokai University
Department of Physics, University of Adelaide, Australia

Fig. 1. Pressure as a function of chemical potential for
NM (solid line) and QM at several pairing interaction
strengths rs .

Fig. 2. Pressure of the ground state of the system as afunction of baryon density for rs = 0.2.

largely restored and color symmetry is broken.
References
1) N. Ishii, W. Bentz, and K. Yazaki: Nucl. Phys. A 578,
617 (1995).
2) W. Bentz and A. W. Thomas: Nucl. Phys. A 696, 138(2001).
3) W. Bentz, T. Horikawa, N. Ishii, and A. W. Thomas:
Nucl. Phys. A 720, 95 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

The EMC eﬀect in an eﬀective quark theory for nuclear matter†
W. Bentz,∗1 H. Mineo,∗2 N. Ishii, A. W. Thomas,∗3 and K. Yazaki∗4[NUCLEAR STRUCTURE FUNCTIONS, EMC Eﬀect, Eﬀective Quark Theories]
In this work we will be concerned with the medium
modiﬁcations of the spin-independent nuclear structure functions measured in deep inelastic scatteringof leptons, that is, the EMC eﬀect. In recent works
we have shown that the quark-scalar diquark description of the single nucleon, which is based on the relativistic Faddeev approach to the Nambu-Jona-Lasiniomodel,1) can be combined successfully with the meanﬁeld description of the nuclear matter equation of state(NMEOS).2) This framework oﬀers a powerful tool forinvestigating the origin of the EMC eﬀect in terms ofbinding on the level of quarks. Here we will consider
the case of inﬁnite nuclear matter as a ﬁrst step, andlimit ourselves to a valence quark description.
By using the solution to the quark-diquark boundstate equation, we calculate the light-cone momentum distributions (LCMDs) of quarks in a single nucleon. The LCMDs in nuclear matter are then obtained by using familiar convolution formalism. Besides the Fermi motion of nucleons, this description takes into account the eﬀect of the mean scalarﬁeld via the density-dependent masses according to
the NMEOS, and also the eﬀect of the mean vector ﬁeld (V0 ). We found that the direct eﬀect of V0
on the LCMDs in nuclear matter can be expressed
F
FV0
fq/A0 (xA =xA −), whereas3) fq/A (xA ) =
EF
EF
EF

fq/A0 (xA ) is the LCMD for V0 = 0, and F = EF + 3V0

2 + p2 ) is the nucleon Fermi energy with
(EF = MNF
MN the eﬀective nucleon mass. The actual calculations are carried out in the proper time regularization
scheme which avoids unphysical quark decay thresholds for the nucleon.
The medium modiﬁcations of the isoscalar valencequark distribution at the saturation density of our
NMEOS are shown in Fig. 1 for the low energy scale
Q0 = 0.4 GeV. The dotted line shows the distribution
in a free nucleon, the dashed line shows the result including the mean scalar ﬁeld, the dotted-dashed line
shows the result including the Fermi motion of nucleons, and the solid line also includes the mean vector
ﬁeld. It is clear from Fig. 1, and also from the scaletransformation given above, that the eﬀect of the mean
vector ﬁeld is to narrow the LCMD, leading to a de†
∗1
∗2
∗3
∗4

Condensed from an article by H. Mineo, W. Bentz, N. Ishii,
A. W. Thomas, and K. Yazaki, Nucl. Phys. A, in press.
Department of Physics, Tokai University
Department of Physics, National Taiwan University, Taiwan
Department of Physics, University of Adelaide, Australia
Department of Physics, Tokyo Woman’s Christian University

Fig. 1. Isoscalar LCMD of quarks. For explanation of thelines, see text.

pletion in the valence quark region and to an enhancement at smaller values of the Bjorken variable. Figure 2 shows the resulting EMC ratio in comparison to
nuclear data extrapolated to the nuclear matter case.
We see that the calculation can reproduce the mainfeatures of the EMC eﬀect, namely the suppression atlarge x and the enhancement at smaller x.

Fig. 2. EMC ratio in isospin symmetric nuclear matter.

References
1) N. Ishii, W. Bentz, and K. Yazaki: Nucl. Phys. A 578,
617 (1995).
2) W. Bentz and A. W. Thomas: Nucl. Phys. A 696, 138(2001).
3) H. Mineo, W. Bentz, N. Ishii, A. W. Thomas, and K.
Yazaki: Nucl. Phys. A, in press.

33

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RIKEN Accel. Prog. Rep. 37 (2004)

Invariant-mass spectroscopy for condensed K̄ nuclear clusters
to be formed as residues in relativistic heavy-ion collisions
T. Yamazaki, A. Doté,∗ and Y. Akaishi∗[kaonic nuclei, dense nuclei, heavy-ion reactions, quark-gluon plasma]
Recently, exotic nuclear systems involving a K̄ (K−or K̄0 ) as a constituent have been studied theoretically by Akaishi and Yamazaki (AY).1,2) Using aphenomenological K̄N interaction combined with themethod of Antisymmetrized Molecular Dynamics, asdeveloped by Doté et al.,3) we predict that few-bodydouble-K̄ nuclei, such as ppK− K− and ppnK− K− , aswell as single-K̄ nuclei, are tightly bound compact systems with large binding energies and ultrahigh nucleon
densities. The results are summarized in Table 1.
We point out that such dense K̄ nuclear clusters canbe produced as residual fragments in relativistic heavyion collisions,4) since the K̄ clusters are by themselves
dense. They are likely to be in a deconﬁned quarkgluon phase, as in QGP, and thus, they will be spontaneously formed, like clusterized islands, remaining
in an expanding hadron gas medium throughout thefreeze-out phase (see Fig. 1) and that their invariant
masses can be reconstructed from their decay particles.4) The decay modes which can be kinematicallyreconstructed are as follows:(i)ppK − → Λ + p,

Table 1. Summary of predicted K̄ clusters. M : total mass
[MeV]. EK : total binding energy [MeV]. ΓK : decay
width [MeV]. ρ(0): nucleon density at the center of thesystem [fm−3 ]. Rrms : root-mean-square radius of thenucleon system [fm].
K̄ cluster
pK −
ppK −
pppK −
ppnK −
ppppK −
pppnK −
ppnnK −
ppK − K −ppnK − K −pppnK − K −

∗

34

2

Mc
[MeV]
1407
2322
3211
3192
4171
4135
4135
2747
3582
4511

EK
[MeV]
27
48
97
118
75
113
114
117
221
230

ΓK
[MeV]
40
61
13
21
162
26
34
35
37
61

ρ(0)
[fm−3 ]
0.59
0.52
1.56
1.50
1.68
1.29

Rrms
[fm]
0.45
0.99
0.81
0.72
0.95
0.97
1.12

2.97
2.33

0.69
0.73

Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)

Fig. 1. Quark gluon plasma and its transition to evaporating hadron gases with heavy and dense residues of K̄
clusters. Dense K̄ can be identiﬁed by their decays.

(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)

ppnK − → Λ + d,
pppK − → Λ + p + p,
ppnnK − → Λ + t,
pppnK − → Λ + 3 He,
ppK − K − → Λ + Λ,
pppK − K − → Λ + Λ + p,
pppnK − K − → Λ + Λ + d.

The condition for observing the free decay of a K̄cluster with a decay width ΓK isτK = h̄/ΓK > τf ,(1)

where τf is the freeze-out time. For ΓK = 20 MeV,
τK ∼ 10 fm/c, which is marginally longer than the estimated freeze-out time, τf ∼ 5 fm/c.
References
1) Y. Akaishi and T. Yamazaki: Phys. Rev. C 65, 044005(2002).
2) T. Yamazaki and Y. Akaishi: Phys. Lett. B 535, 70(2002).
3) A. Doté, H. Horiuchi, Y. Akaishi, and T. Yamazaki:
arXiv:nucl-th/0207085.
4) T. Yamazaki, A. Doté, and Y. Akaishi: arXiv:nucl-th/
0310085.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Chiral symmetry in the light-cone field theory
F. Lenz,∗1 M. Thies,∗1 K. Ohta,∗2 and K. Yazaki∗3[HADRON PHYSICS, Chiral Symmetry, Light-Cone, Ward-Takahashi Identity]
As a continuation and generalization of the work
reported last year,1) chiral symmetry and its spontaneous breakdown in light-cone ﬁelf theory are studied
with a Lagrangian of the following structure,i †
L = iϕ D+ ϕ + iχ D− χ + √ χ† Dm ϕ − ϕ† Dm
χ2(1)+ Lint (ϕ, χ),
†

†

where
Dm = σ3 D1 + iD2 − iσ1 m.

(2)The covariant derivative, D, couples the fermions toan external gauge ﬁeld, which can be made dynamical
by an obvious generalization. Only the spinor ϕ is
dynamical since no time derivative of χ is present. We
start our investigations with the generating functional 
Z[η, γ] = D[ϕ, χ] i d4 x



†
†
†
†
· L+η ϕ+ϕ η+γ χ+χ γ .
(3)
We use the form in which four-fermion interactions are
eliminated in favor of two auxiliary bosonic ﬁelds, σand π. By integrating the constrained variable χ anddeﬁning D⊥ as
D⊥ = σ3 D1 + iD2 − ig(σσ1 + πσ2 ) − imσ1 ,(4)

the generating functional becomesZ[η, γ] = D[ϕ, σ, π] exp {iS[ϕ, σ, π] + is[η, γ]} ,(5)with action and source terms given respectively byHere, the composite ﬁeld χ is deﬁned as

∗1
∗2
∗3

σ =

M
,
g

π = 0 ,(7)

implying a nonvanishing chiral condensate 0|ψ̄ψ|0.
To study the consequences of this assumed breakdown of the chiral symmetry, we consider the following
inﬁnitesimal nonlocal transformation of the fundamental ﬁelds ϕ(x) with x⊥ -independent α.
δϕ(x) = iα(x+ , x− )Σ3 ϕ(x)

(8)

with
−1
[σ3 , DM ] =Σ3 = DM

2M 2 σ3 − 2iMσ⊥ ∂⊥.
−∆⊥ + M 2

(9)

The operator Σ3 coincides with the pion operator atzero transverse momentum which can be derived in
the NJL model by solving the light-cone BS equation
explicitly in ladder approximation.2) If we neglect theﬂuctuations of the auxiliary ﬁelds σ and π, χ transforms only in the presence of a nonvanishing bare quark
mass,
√
2m
δχ = iα(x+ , x− )σ2 ϕ .
(10)
D−With the above transformation, we obtain a chiralWard-Takahashi identity, which leads to the GellMann-Oakes-Renner(GOR) relation.

d2 x⊥ ϕ† σ2 χ + χ† σ2 ϕ (y)0 = D[ϕ]eiS[ϕ,σ,π]· ∂+ (ϕ† Σ3 ϕ)(x) +S[ϕ, σ, π]
1= d4 x iϕ† D+ ϕ + iχ† D− χ − (σ 2 + π 2 ) ,2s[η, γ]



4
†
†
†
†
† i
γ .
= d x η ϕ+ϕ η+γ χ+χ γ +γD−1
χ = χ[ϕ] = − √D⊥ ϕ .
2D−

The spontaneous break down of the chiral symmetry
is deﬁned by the expectation values of the auxiliaryﬁelds,√2m(χ† σ2 ϕ + ϕ† σ2 χ)(x)−δ(x+ − y + )δ(x− − y − ) ϕ† Σ3 σ2 χ − χ† σ2 Σ3 ϕ (y) .
We have succeeded in connecting the meson ﬁeld operator to the generator of a unitary x± -dependenttransformation.
Further analyses in the Fouriertransformed forms conﬁrm that the pion dominancedoes hold in the chiral limit and the GOR relation iscorrectly obtained.

(6)

Institute for Theoretical Physics, University of Erlangen,Germany
Institute of Physics, University of Tokyo
College of Arts and Sciences, Tokyo Woman’s Christian University

References
1) F. Lenz, M. Thies, K. Ohta, and K. Yazaki: RIKEN
Accel. Prog. Rep. 36, 44 (2003).
2) W. Bentz, T. Hama, T. Matsuki, and K. Yazaki: Nucl.
Phys. A 651, 143 (1999).

35

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Electron cooling by electron beam of anisotropic velocity distribution
with variable Coulomb logarithm
H. Amemiya, H. Tsutsui, and T. Katayama[Electron cooling, Anisotropic velocity distribution, Coulomb logarithm]
The aim of the present paper is to obtain the cooling rate of an ion beam by an electron beam with thelongitudinal electron temperature being very low dueto the beam acceleration.
For an ion traveling with a velocity V in electrons
with a velocity distribution f (v), the loss rate of kinetic
energy dEp /dt and the rate of energy increment dEt /dt
become in the beam frame

4πQ
dEp
1 U → →
(1)=−V
Lc · 2 f ( v )dv ,
dt
m
U U

dEt
4πQ
1 → →
(2)
=
Lc · f ( v )dv ,dtMUwhere Q = Ne Z 2 e4 /(4πεo )2 , Ne is the electron density,
M is the ion mass, m is the reduced mass me M /(M +me ), Z is the charge state of the ion, and U is therelative velocity between the ion and electrons. Lc
is the Coulomb logarithm given by ln(λeﬀ /ρm ), whereρm is the minimum impact parameter Ze2 /(4πεo mU 2 )which depends on U and λeﬀ is the eﬀective Debye
length which varies with the angle θ of the ion velocity
vector to the beam axis due to the anisotropic velocity
distribution of electrons. Therefore, contrary to theprevious cases,1,2) Lc is variable and placed inside theintegrals.
With the acceleration of electrons to the energy Eo ,the longitudinal electron temperature To becomesκTo = (κTe )2 /2(γ + 1)Eo ,(3)

where Te is the electron temperature in the transverse
direction and near the cathode temperature, ∼103 K.
For the case of Eo = 100 keV, Te = 103 K, Eq. (3) gives
To = 2 × 10−4 K. However, due to the plasma eﬀect,
it is heated toκTo = mωp2 d2 /4π = e2 Ne1/3 /4πεo ,(4)where ωp is the angular plasma frequency and d theaverage distance. For a typical case of Ne = 108 cm−3 ,Eq. (4) gives To ∼ 0.78 K The noise of the power supply
is neglected.
The Debye length λeﬀ becomes anisotropic as
λeﬀ = λ[cos2 θ + η 2 sin2 θ]1/2 ; tan θ = β/α.

(5)where λ = (εo κTe /Ne e2 )1/2 and η 2 = To /Te . α are β
are velocities of the ion in the longitudinal and transverse directions normalized by st = (2κTe /me )1/2 , respectively. Hence, the Coulomb logarithm Lc can bedivided as

36

Lc = Lo + (3/2)L(θ) + ln(U/st )2 ,L(θ) = ln[cos2 θ + η 2 sin2 θ],

(6)
(7)

where Lo = ln(6ND /Z) + ln(m/me ) and ND =Ne (4π/3)λ3 are constants.
Next, the dimensionless potentials φ1 and φ2 deﬁned
previously3,4) to obtain the cooling and heating rates
for ions with ρ2 = α2 + β 2 are calculated. Namely,

1
→ →
(8)
f ( v )dv ,φ1 (ρ) = −(U/s)
ln(U/s)2 → →φ2 (ρ) = −(9)f ( v )dv .
(U/s)
Substituting Eqs. (8) and (9) into Eqs. (1) and (2),
we obtain the rates of energy change in the θ directionasdEp (θ)dt
3= −C (Lo + 2)ρ∇φ1 + L(θ)ρ∇φ1 + ρ∇φ2
2
(10)


dEt (θ)
m
3
= −C
(11)
Lo φ1 + L(θ)φ1 + φ2 .
dt
M
2
where C = 4πQ/ms, s = (2κTe /m)1/2 , φ1 = φ1 (ρ, θ),
φ2 = φ2 (ρ, θ), ρ∇φ1 = α∇α φ1 + β∇β φ1 , and ρ∇
φ2 = α∇α φ2 + β∇β φ2 .
Equations (10) and (11) indicate cooling and heating rates of an ion for any form of f (v). L(θ) and φ2
denote corrections to previous theories1,2) which consider only the eﬀects of φ1 and Lo . If f (v) is isotropic,
our previous result3,4) is recovered by putting ρ = α
and L(θ) = 0.
It should be noted that the electron-cooling theory isvalid only for Lc > 0. Applying this to L(θ) in Eq. (7)for a small η (∼ 0), we have the requisite condition assin θ < [1 − exp(−Lo )]1/2 . The allowable upper limit
angle θc becomes θc = 82.2◦ for Lo = 2 and θc = 89.6◦
for Lo = 5. As Lo is larger, the theory almost covers
θc up to π/2.
The present theory accounts for the velocity and angle dependences of dEp /dt and dEt /dt for a given electron beam of f (v), Ne and Eo .
References
1) H. Poth: Phys. Rep. 196, 135 (1990).
2) I. N. Meshkov: Phys. Part. Nucl. 25, 631 (1994).
3) H. Amemiya, T. Tanabe, and T. Katayama: J. Phys.
Soc. Jpn. 73, 617 (2004).
4) H. Amemiya, T. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 36, 45 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Electron cooling by two-temperature electron beamwith extremely cold longitudinal temperature
H. Amemiya, H. Tsutsui, and T. Katayama[Electron cooling, Two-temperature velocity distribution, Coulomb logarithm]
In a previous study, the cooling and heating rates ofan ion by an electron beam with a general anisotropic
velocity distribution have been obtained.1) This study
is intended to meet the experimental requirements forelectron cooling. As a typical electron velocity distribution f (v), the two-temperature Maxwellian type isconsidered.
2πt(1)f (u, t)dudt = 3/2 exp(−u2 ) exp(−t2 )dudt.
πHere, u = vp /sp , t = vt /st , sp = (2κTo /m)1/2 , st =(2κTt /m)1/2 ∼ (2κTe /m)1/2 , vp and vt are electron
velocities in the longitudinal (beam direction, x) andtransverse (on the y-z surface) directions, Te is theelectron temperature in the source, and To and Tt are
the electron temperatures in the beam in the directionsof u and t, respectively.
Normalizing the ion velocities Vp and Vt in the x andy directions as α = Vp /st and β = Vt /st , we have therelative velocity U between the ion and electrons.

1/2= (α − uη)2 + (β + t)2 − 4βt sin2 ψ,(2)DHere, η = sp /st = (To /Tt )1/2 and ψ = (π − χ)/2,
χ being the angle between Vt and vt . The functions
φn (α, β; η) for the cooling and heating rates2) become
as follows (n = 1, 2).
224[ln(U/st )2 ]n−1 e−u te−tdudtdψ, (3)φn = − 3/2
π
D1/2

2
2
(α − uη)e−u te−t4
∇α φ1 = 3/2
dudtdψ,
(4)
π
D3/2
∇β φ1

2
2
[(β + t) − 2βt sin2 ψ]e−u te−t
4
= 3/2
dudtdψ,π
D3/2(5)where integrals are triple for u = −∞ to ∞, t = 0 to
∞ and ψ = 0 to π/2. For ∇α φ2 and ∇β φ2 , integrands
are multiplied by −(2 − ln D) to those of ∇α φ1 and∇β φ1 .
Usually η is small, ∼1/40. In the case of η = 0,
the integral on u is decoupled and using K(k) and logelliptic integral L(k) deﬁned before,1) we obtain2
4 ∞ te−tφ1 = −
K(k)dt,(6)
π 0 ∆1/22∞ln ∆ · te−t4φ2 = −
K(k)dt
(7)
π
∆1/2
0

 ∞
+
0


2
te−t
L(k)dt ,∆1/2

2

where k = 4βt/∆, ∆ = α2 + (β + t)2 . For the ion
moving parallel to the beam axis (β = 0), k = 0, K =π/2 and L = 0. Then,√(8)
φ1 = − π exp(α2 )[1 − erf(α)],
2∇α φ1 = 2(1 + αφ1 ), ∇α φ2 = 2(ln(α ) + αφ2 ), (9)and ∇β φ1,2 = 0. φ2 are numerically obtained.
Figure 1 shows −φ1 and −φ2 related to the heating
rate vs. ρ = (α2 + β 2 )1/2 for some θ = tan−1 (β/α)
compared with the isotropic case,1) η = 1.
Figure 2 shows −ρ ∗ ∇φ1,2 = α∇α φ1,2 + β∇β φ1,2
related to the cooling rate vs. ρ for some θ comparedwith the case of η = 1.

Fig. 1. −φ1 and −φ2 vs. ρ for some θ.

Fig. 2. −ρ ∗ ∇φ1,2 = α∇α φ1,2 + β∇β φ1,2 vs. ρ for some θ.

References
1) H. Amemiya, H. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 36, 45 (2003).
2) H. Amemiya, H. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 37, 36 (2004).

37

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Cooling rate of ion beam by electron cooling with flat electron
velocity distribution with variable Coulomb logarithm
H. Amemiya, H. Tsutsui, and T. Katayama[Electron cooling, Cooling rate, Flat distribution, Ion beam, Coulomb logarithm]
In previous studies on electron cooling (EC),1,2) therate of energy change of a single ion by an electron
beam of anisotropic velocity distribution f (v) has beenobtained. Using this, the cooling and heating rates ofan ion beam can be obtained through integration overan ion velocity distribution F (V ). Here, F (V ) is taken
typically as Maxwellian with a temperature Ti . In the
beam frame, F (V ) is expressed in the reduced form as
F (σ, θ)dσdθ =4√ σ 2 exp(−σ 2 )dσ sin θdθ,
π π

(1)

where σ = V /si , si = (2κTi /M )1/2 , M is ion mass andθ (= 0 to π/2) is the angle of ion velocity to the beamaxis.
The cooling and heating rates lead to1,2)dĒp (θ)
dt




3
= −C
F (σ) Lo + 2 + L(θ) ρ∇φ1
20
+ ρ∇φ2 dσ,

dĒt (θ)
dt
= −C

m
M

and Wp1 and Wt1 lead toξ2
Wp1 = − √,2
π (ξ + 1)3/2

ξ2
Wt1 = √.
2
π (ξ + 1)1/2(8a, b)Figure 1 shows Wp1 and Wp2 vs. ξ = se /si for θ = 0
to π/2 in the case of completely flat distribution η = 0.
Figure 2 shows Wt1 and Wt2 vs. ξ = se /si for θ = 0
to π/2 for η = 0. It is seen that except in the range
of very small ξ, Wp2 and Wt2 are opposite in sign toWp1 and Wt1 , respectively. In the storage ring, theion beam broadens by the intrabeam scattering (IB).5)
An equilibrium ion temperature will be reached after
numerous repetitions of EC and IB.

∞

 ∞
F (σ)
0

(2)




3
Lo + L(θ) φ1 + φ2 dσ.
2(3)Fig. 1. Wp1 and Wp2 vs. ξ = se /si for some θ.

where φ1 and φ2 are functions of ρ and θ, and C =4πQ/ms, s = (2κTe /m)1/2 , Q = Ne Z 2 e4 /(4πεo )2 ,Lo = ln(6mND /me Z), ND = Ne (4π/3)λ3 , λ =εo κTe /Ne e2 )1/2 , and m−1 = me −1 + M −1 .
We define cooling and heating functions as ∞F (σ)[ρ∇φ1,2 (ρ, θ)]dσ,(4)
Wp1,2 (ρ, θ) ≡ − 0∞
F (σ)φ1,2 (ρ, θ)dσ.
(5)
Wt1,2 (ρ, θ) ≡ −0Therefore, Eqs. (2) and (3) can be reduced to
3 L(θ)
dĒp (θ)= Wp1 (θ) 1 +CLo dt2 Lo+ [2Wp1 (θ) + Wp2 (θ)]/Lo ,
(6)




m
dĒt (θ)
3 L(θ)=+ Wt2 (θ)/Lo .
Wt1 (θ) 1 +CLo dtM
2 Lo(7)
In the conventional case (η = 1),3,4) Wp2 = Wt2 = 0

38

Fig. 2. Wt1 and Wt2 vs. ξ = se /si for some θ.

References
1) H. Amemiya, H. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 36, 45–47 (2003).
2) H. Amemiya, H. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 37, 36, 37 (2004).
3) H. Poth: Phys. Rep. 196, 135 (1990).
4) I. N. Meshkov: Phys. Part. Nucl. 25, 631 (1994).
5) J. D. Bjorken and S. K. Mtingwa: Part. Accel., 13, 115(1983).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Ultimate temperature and cooling time of ion beam by electron
cooling: Dependence on Coulomb logarithm
H. Amemiya, H. Tsutsui, and T. Katayama[Electron cooling, Cooling rate, Flat distribution, Ion beam, Coulomb logarithm]
Using the cooling and heating functions of an ion
beam,1,2) the eﬀective cooling rate R(θ, ξ) of an ion
beam with a temperature Ti is given bydκTi= R(ξ, θ),(CLo )dt


3L(θ)
R(ξ, θ) = (Wp1 + εWt1 ) 1 +2Lo
2Wp1 + Wp2 + εWt2
.
+
Lo

(1)

(2)

Here θ is the angle of the ion velocity to the beamaxis, Lo is the constant part of Coulomb logarithm,
C = 4πQ/ms where s = (2κTe /m)1/2 and Q =Ne Z 2 e4 /(4πεo )2 , L(θ) = ln[cos2 θ + η 2 sin2 θ] whereη 2 = To /Te , To (∼1 K) and Te (∼103 K) being longitudinal and lateral electron temperatures, ε = me /M ,m−1 = me −1 + M −1 and Wp1,2 and Wt1,2 are the cooling and heating functions of ion beam obtained.1,2)
Figure 1 shows R(θ, ξ) vs. ξ = se /si , where se =(2κTe /me )1/2 and si = (2κTi /M )1/2 , in the case of
a ﬂattened electron velocity distribution f (v) (η = 0)
for 238 U together with isotropic f (v) (η = 1) with Lo
as a parameter. R < 0 corresponds to the coolingof ions. In typical experiments, η 2 is ∼ 10−3 (η 2 =To /Te , longitudinal and lateral electron temperatures
To ∼1 K and Te ∼ 103 K). Therefore, the assumptionof η = 0 is a good approximation. The eﬀects of Wt1,2
are smaller than those of Wp1,2 and appear only nearthermal equilibrium: R = 0.
Due to the angular dependence of cooling, the temperature of the ion beam becomes anisotropic. The
critical ξ at R = 0 corresponds to the ultimate ion
temperature Ti∞ . When Lo is not large, ions withlarge θ are cooled only to a certain limit.

Figure 2 shows ultimate Ti∞ vs. Lo for 238 U. Abovea certain Lo , a marked decrease in Ti∞ is observed
and then Ti∞ reaches a very small value. A marked
contrast from the case of η = 1 (dotted curve) is observed, suggesting the importance of the eﬀects of ﬂat
f (v) and L(θ). It is favorable to choose large Lo toachieve eﬀective cooling for all θ values.
For large Lo , the ﬁrst term of the right-hand side ofEq. (2) becomes predominant. Ti∞ can be estimatedfrom the balance
Wp1 + εWt1 ∼ 0.

(3)
1/2

1/2

− (4/π ) cos θ/ξ andSubstituting Wt1 ∼ π
Wp1 ∼ −(4/π 1/2 ) cos θ/ξ, we obtain, from Eq. (3),πcos θ= ε or
ξ
4

Ti∞
me
π2
.
=
Te
16 cos2 θ M(4)Then, the minimum Ti∞ is 0.62(me /M )Te at θ = 0
and decreases with θ. Near θ = π/2, Ti decreases
slowly but its value is smaller than in the isotropic caseup to θ = cos−1 (ε1/2 π/4) as long as L(θ) > −2Lo /3.
Deﬁning τ = t(CLo /κTe )me /M , we obtain
 ξ
1
2dξ
dξ(θ)
= − ξ 3 R(ξ, θ) or τ = −
. (5)
3
dτ
2
ξo ξ R(ξ, θ)
Here, ξo corresponds to the initial ion beam temperature. The cooling time scale is proportional to
Ne Z 2 /M and the integral gives a modiﬁcation factor
that depends on the angle.

Fig. 2. Ultimate ion temperature Ti∞ vs. Lo for 238 U.

References

Fig. 1. Cooling rate R(ξ, θ) vs. ξ for some Lo values.

1) H. Amemiya, H. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 36, 45–47 (2003).
2) H. Amemiya, H. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 37, 36–38 (2004).

39

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Mathematical tools for electron cooling by electron beam withstrongly anisotropic velocity distribution
H. Amemiya, H. Tsutsui, and T. Katayama[Mathematical tool, Electron cooling, Electron beam, Ion beam, Magnetic ﬁeld]
The present note is concerned with new functions
and integrals associated with electron cooling (EC),particularly the anisotropic velocity distribution, andthe eﬀects of magnetic ﬁeld are treated.
Due to acceleration, the electron beam is strongly
anisotropic. A parameter η = sp /st = (To /Te )1/2 hasbeen introduced to represent the anisotropy, where sp
and st are electron thermal velocities in the longitudinal and lateral directions, respectively, and To and Te
respective electron temperatures. The results of thecase To = 0 or η = 0 have already been given.1) The
cooling functions φ1 and φ2 and the gradients ∇α,β φ1,2
for small η can be given by Taylor expansion.
Optimum cooling occurs when the ion velocity isparallel to the beam axis (α > 0, β = 0), α and β being
the longitudinal and lateral velocities normalized by se .
In this ideal case, we can put k = 0 (k2 = 4βt/∆,∆ = α2 + (β + t)2 ). In a previous note,2) the logelliptic integrals L and M and their derivatives Ln
and LSn were introduced. Those without log are theelliptic integrals K and E and their derivatives Kn
and KSn .3) It follows for k = 0 that E = K = K3 =K5 = π/2, KS3 = KS5 = π/4, and M = L = L3 = L5 =LS = LS3 = LS5 = 0. φ1,2 and ∇α,β φ1,2 become
φ1 (α, 0; η)
 ∞


=−
exp −u2 + (α − uη)2 erfc(|α − uη|)du,−∞(1)
φ2 (α, 0; η)
 ∞


= −2
exp −u2 + (α − uη)2 Lx(|α − uη|)du.
−∞(2)
Here, we deﬁne new integrals as ∞ln t · exp(−t2 ) dt.
(A)
Lx(x) ≡x ∞exp(−x)I2n−1 =
n = 1, 2, 3, . . .
√2n−1 dx,0
α2 + x(B) ∞ln[α2 + x] exp(−x)
J2n−1 =
dx,
√
2n−1
0
α2 + xn = 1, 2, 3, . . .
(C)Then, we have −φ1 = I1 , −φ2 = J1 , and for α  uη
∇α φ1 = αI3 , ∇α φ2 = α(−2I3 + J3 ), and their derivatives (denoted as prime) over η are

40



η
J3

. (3)
φ1 (α, 0; 0) = I3 , φ2 (α, 0; 0) = η −I3 +2
2∇α φ1  (α, 0; 0) = 3αηI5 ,∇α φ2  (α, 0; 0) = αη[8I5 − 3J5 ],(4)
∇β φ1,2 (α, 0; η) = ∇β φ1,2 (α, 0; η) = 0.
(5)
The opposite case α  uη occurs near the temperature equilibrium where the expansion is not applied.
Due to the oscillatory motion of electrons in themagnetic ﬁeld, the Coulomb logarithm is modiﬁed as4)
 1/ωpdτ
cos ωτ,(6)ln Λ =
ρm /ve τ
where ve = (κTe /me )1/2 , ω and ωp are the angularelectron cyclotron and plasma frequencies, and ρm theminimum impact parameter. Equation (6) becomes λD (v/ve ) λD
1
sin2 (r/2rL )dr − 2dr, (7)ln Λ =r
ρm r
ρm (v/ve )where r = vτ , v being the velocity of individual electron, rL = v/ω and λD = ve /ωp .
We deﬁne a new function Σ(x) as x
sin2 ξdξ,(D)
Σ(x) =
ξ
0which is 0 at x = 0 and increases with x and approaches to (ln(2x) + γ)/2 − sin(2x)/4x at large x.
Inﬂections appear at points 2x = tan x. Then, 
λDln Λ = ln(8)− 2[Σ(ξ2 ) − Σ(ξ1 )].
ρmwhere ξ1 = ωρm /2ve and ξ2 = ωλD /2ve = ω/2ωp . The
ﬁrst term of RHS is the Coulomb logarithm Lc withoutmagnetic ﬁeld, while the second term gives the gyration eﬀect.
References
1) H. Amemiya, H. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 37, 36–39 (2004).
2) H. Amemiya, H. Tsutsui, and T. Katayama: RIKEN
Accel. Prog. Rep. 36, 47 (2003).
3) M. Abramovitz and I. A. Stegun: Handbook of Mathematical Functions with Formulas, Graphs and Mathematical Tables, 9th ed. (Dover, New York, 1970).
4) I. P. Shkalovsky, T. W. Johnston, and M. P. Bachinsky:
The Particle Kinetics of Plasmas (Addison-Wesley,
London, etc., 1966).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Superheavy hydrogen 5 H†
A. A. Korsheninnikov, M. S. Golovkov, I. Tanihata, A. M. Rodin,∗1 A. S. Fomichev,∗1 S. I. Sidorchuk,∗1
S. V. Stepantsov,∗1 M. L. Chelnokov,∗1 V. A. Gorshkov,∗1 D. D. Bogdanov,∗1 R. Wolski,∗1
G. M. Ter-Akopian,∗1 Yu. Ts. Oganessian,∗1 W. Mittig,∗2 P. Roussel-Chomaz,∗2
H. Savajols,∗2 E. A. Kuzmin,∗3 E. Yu. Nikolskii,∗3 and A. A. Ogloblin∗3
NUCLEAR REACTION, p(6 He,2 He)5 H, E = 36A MeV, Nuclear structure
The very neutron-rich nucleus 5 H having an extreme
fraction of neutrons, N/Z = 4, has been the objectof research for more than 40 years. Numerous earlyexperiments attempted to observe a particle-stable 5 H,
either by its beta activity or by direct detection of 5 H,
thus ﬁnally proving its instability. Later experiments
focused on unbound 5 H. However, the existence of 5 H
resonance remained unclear.
In the present paper, we report on an experimental
study of 5 H. We applied a technique that resembles themissing-mass method, but with detection of an unstable recoil nucleus. In conventional missing-mass experiments, the binary reaction A(b, c)D is studied, and by
detecting nucleus c, one obtains the excitation energy
spectrum of the residual system D. Generally speaking, the more neutron-rich system D we want to study,
the more proton-rich nucleus c has to be detected. As
a result, nucleus c can even be unstable, e.g., 6 Be, thatdecays into p+p+α, or singlet-state 2 He, that decays
into p+p. Nevertheless, we can deal with the unstable
nucleus c, if all particles from its decay are detected.
Having kinematically complete information on the unstable system c, we can reconstruct the excitation energy in the residual nucleus D and can perform its
spectroscopy.
The reaction p(6 He,2 He)5 H was chosen for the
search for 5 H. It is reasonable to expect that neutrons
in the ground state of 5 H occupy the same orbitals as
those in 6 He. Hence, by removing one proton from6
He, we should selectively populate the ground state
1/2+ of 5 H. In other interesting reactions, such ast(t,p)5 H and t(6 He,4 He)5 H, the two-neutron transfer
is expected to populate also excited states 5/2+ and3/2+ , which are predicted by theoretical calculations.
These broad excited states will render more diﬃcult, if
not impossible, the identiﬁcation of the ground state.
To detect all particles from the decay of the unstable recoil system c in the reaction A(b, c)D, we built
the RIKEN telescope, which is a stack of solid-state

†
∗1
∗2
∗3

strip detectors. This telescope enables the measurement of angles, energy losses and energies of several
particles detected in coincidence. The detectors havean annular hole for the beam. With this geometry, decay products of the system c can be detected at small
angles in the laboratory system in inverse kinematics
typical for many experiments with secondary beams.
The secondary beam of 6 He at 36 A MeV was obtained using the fragment separator ACCULINA at
JINR (Dubna). Two plastic scintillators were used
for the identiﬁcation of each particle of the secondary
beam and for the measurement of its energy by timeof-ﬂight. The trajectory of 6 He was measured by two
multiwire proportional chambers. We used a cryogenic
target from GANIL (France), which was ﬁlled with hydrogen gas at a temperature of 35 K and pressure of
10 atm. The two protons originating from the decay of2
He were detected in coincidence by the RIKEN telescope. Besides protons, we also detected tritons fromthe decay 5 H→t+n+n, using a downstream telescope
which consisted of a large-area SSD detector and a
BGO crystal.
The key of this experiment was the combination of
the exotic 6 He beam provided by the fragment separator ACCULINA (Dubna, Russia), the hydrogen cryogenic target from GANIL (France), and the detection
system based on the telescope of ringlike solid-state
strip detectors (RIKEN).
The excitation energy spectrum obtained for this reaction shows a peak corresponding to a resonance 5 H
at 1.7 ± 0.3 MeV above the n+n+t threshold with awidth of 1.9 ± 0.4 MeV. The angular distribution of
the p(6 He,2 He)5 H reaction was measured as well as
the energy correlation of two protons. The former hasa shape consistent with the angular momentum transfer l = 0 expected for the population of 5 Hg.s (1/2+ ),while the latter conﬁrms the emission of the 2 He virtual state in the reaction studied.

Condensed from Phys. Rev. Lett. 87, 092501 (2001)
Joint Institute for Nuclear Research, Russia
Grand Accelerateur National D’Ions Lourds, France
Kurchatov Institute, Russia

41

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Experimental evidence for existence of 7 H†
A. A. Korsheninnikov, E. Yu. Nikolskii, E. A. Kuzmin, A. Ozawa, K. Morimoto, F. Tokanai,
R. Kanungo, I. Tanihata, N. K. Timofeyuk,∗1 M. S. Golovkov,∗2 A. S. Fomichev,∗2 A. M. Rodin,∗2
M. L. Chelnokov,∗2 G. M. Ter-Akopian,∗2 W. Mittig,∗3 P. Roussel-Chomaz,∗3 H. Savajols,∗3
E. Pollacco,∗4 A. A. Ogloblin,∗5 and M. V. Zhukov∗6
NUCLEAR REACTION, p(8 He, pp)7 H, E = 61.3 A MeV, Nuclear structure
Progress in experimental technique including usage of secondary beams of short-lived radioactive nuclei has enabled studies of exotic nuclear systems inthe vicinity and beyond the neutron drip line. Recently, experimental studies of 5 H have been performed in the reactions p(6 He, 2 He)5 H,1) t(t, p)5 H,2)and d(6 He, 3 He)5 H.3) These three measurements show
a peak of 5 H at ∼ 1.8 MeV above the decay threshold into t + 2n. Another recent experiment4) devoted
to 5 H show a 5 H peak at relatively higher energy. Dueto the known systematics of helium isotopes, where8
He having two more neutrons than 6 He is more boundrelative to the separation of two neutrons than 6 He,
and where 7 He is less unbound than 5 He, the resultsfor 5 H allow us to speculate that 7 H may exist asa state in the vicinity of the t + 4n decay threshold.
Hardly 7 H exists as a bound state. In numerous
measurements performed previously using the ∆E-E
method, the region of hydrogen and helium isotopes
was studied in detail and no hyperbole of the bound 7 H
in two-dimensional ∆E-E plots was observed. However, 7 H may exist as an unstable state. Being close
to the threshold, 7 H could be a particularly interesting system. It should undergo the unique ﬁve-particle
decay into the t + 4n channel and its width may bevery narrow. An extreme fraction of neutrons in 7 H,
N/Z = 6, is comparable with that in neutron stars.
The experimental search for unstable 7 H presents
a diﬃcult task, and this resonance has never been observed. Recent theoretical calculation of 7 H within theseven-body hyperspherical functions method suggeststhat 7 H can be unbound with respect to the t + 4n
decay by 840 keV.5)
We carried out an additional attempt to estimate theenergy range for 7 H to be measured. In the present
calculations, we used the K-harmonics approach andcalculated 3,5,7 H and 4,6,8 He as A-body systems trying
to reproduce the binding energies of 3,5 H and 4,6,8 He
simultaneously. As a result, we obtained for the 7 H
†
∗1
∗2
∗3
∗4

∗5
∗6

42

Condensed from the article in Phys. Rev. Lett. 90, 082501(2003)
University of Surrey, UK
Joint Institute for Nuclear Research, Russia
Grand Accelerateur National D’Ions Lourds, FranceDépartement D’Astrophysique, de Physique des Particules,
de Physique Nucléaire et de L’Instrumentation Associée,FranceKurchatov Institute, Russia
Chalmers University of Technology and Göteborg University, Swedenenergy relative to the t + 4n threshold an estimate ofabout 3 MeV as an upper limit.
Considering the experimental search for 7 H, we considered the following. It is reasonable to suppose thatneutrons in the ground state of 7 H occupy the same orbitals as those in 8 He. Hence, by removing one proton
from 8 He, we should obtain a good chance of populating the ground state 1/2+ of 7 H. Consequently, we
have chosen the reaction p(8 He, pp)7 H for the experimental search for 7 H.
The experiment was performed at RIKEN using
a secondary beam of 8 He produced by the fragment
separator RIPS from the fragmentation of a primarybeam of 18 O. The obtained secondary 8 He beam hada very high intensity of ∼ 300000 particles per secondand an energy of 61.3 A MeV with an energy spread of
2.6 A MeV. (The beam energy and parameters of themeasuring system were optimized in computer simulations preceding the experiment.)
As a proton target, we used a cryogenic target fromGANIL (France), which was ﬁlled with hydrogen gas
at a temperature of 35 K and a pressure of 10 atm. The
target thickness was 6 × 1021 protons/cm2 .
The two protons originating from the reactionp(8 He, pp)7 H were detected in coincidence by the
RIKEN telescope which is a stack of Si strip detectors.
This telescope enables for the detection of several particles in coincidence, identiﬁcation of each particle andmeasurement of their energies and angles.
Experimental results obtained in the pp-coincidences
show a very interesting feature: a very rapid increasein the 7 H spectrum near the t + 4n threshold. The experimental spectrum increases near the threshold evenmore sharply than a two-body phase-space. This provides a strong indication of the possible existence ofthe 7 H state near the t + 4n threshold. For further
studies of 7 H, apart from the p(8 He, pp)7 H reaction,
reactions d(8 He, 3 He)7 H and t(8 He, 4 He)7 H also seemto be promising.
References
1) A. A. Korsheninnikov et al.: Phys. Rev. Lett. 87,
092501 (2001).
2) M. S. Golovkov et al.: Phys. Lett. B 556, 70 (2003).
3) G. M. Ter-Akopian et al.: under preparation for publication.
4) M. Meister et al.: Nucl. Phys. A 723, 13 (2003).
5) N. K. Timofeyuk: Phys. Rev. C 65, 064306 (2002).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Experimental evidence for a specific structure of 8 He†
A. A. Korsheninnikov, E. Yu. Nikolskii, E. A. Kuzmin, A. Ozawa, K. Morimoto, F. Tokanai,
R. Kanungo, I. Tanihata, N. K. Timofeyuk,∗1 M. S. Golovkov,∗2 A. S. Fomichev,∗2 A. M. Rodin,∗2
M. L. Chelnokov,∗2 G. M. Ter-Akopian,∗2 W. Mittig,∗3 P. Roussel-Chomaz,∗3 H. Savajols,∗3
E. Pollacco,∗4 A. A. Ogloblin,∗5 and M. V. Zhukov∗6
NUCLEAR REACTION, p(8 He, t)6 Heg.s. , p(8 He, t)6 He∗ (2+ ), E = 61.3 A MeV, Nuclear
structure
We investigated the two-neutron transfer reactionp( He, t) populating the ground and excited 2+ stateof 6 He. The experiment was performed at RIKEN
using a secondary beam of 8 He produced by thefragment separator RIPS from the fragmentation ofa primary beam of 18 O. The obtained secondary
8
He beam had an intensity of ∼ 300000 pps and an
energy of 61.3 A MeV. As a proton target we useda cryogenic target from GANIL (France), which was
filled with a hydrogen gas at a temperature of 35 K
and a pressure of 10 atm. The target thickness was
6 × 1021 protons/cm2 . The recoil triton from thep(8 He, t) reaction was detected using the RIKEN telescope which is a stack of Si strip detectors. In addition
we detected 6 He nuclei and α particles from the decayof 6 He∗ (2+ ) into α + 2n using a downstream detection
system consisting of a dipole magnet and plastic scintillators.
Let us first consider the simplest assumption on the
structure of 8 He (below we will see that in reality another configuration is realized in 8 He). If the groundstate of 8 He would contain subsystem 6 He mainly inthe state 0+ , then the 8 He(p, t) reaction would populate preferentially 6 Heg.s. (0+ ). The cross section forthe population of 6 He∗ (2+ ) would be some order ofmagnitude lower, because the latter would be the second order process. It requires a two-neutron peak-up
from 8 He, such as in p(8 He, t)6 Heg.s. , but in addition,in this case, the 6 He(0+ ) subsystem should be excited
to the 2+ state. As a result, the cross section of thep(8 He, t)6 He∗ (2+ ) reaction would be suppressed.
The obtained experimental data show that in reality,
the situation is just the opposite: the cross section of
8

†
∗1
∗2
∗3
∗4

∗5
∗6

the p(8 He, t)6 He∗ (2+ ) reaction is higher than that ofp(8 He, t)6 Heg.s. . It denotes that the ground state of8
He contains the subsystem 6 He in the 2+ state witha large weight.
Qualitatively, it is consistent with the consideration of 8 He in a simple model shown in Ref. 1, wherea five-body (α + 4n) wave function of 8 He was constructed with the four antisymmetrized neutrons in the
p3/2 states relative to the α core. Within this model,
one can strictly investigate the spin-parity of the 6 He
subsystem in 8 He. As a result we obtained weights
for various J π in the 6 He subsystem: P (0+ ) = 16 ,P (1+ ) = 0, P (2+ ) = 56 , P (3+ ) = 0. That is, the excited 2+ state of 6 He is predominant in the 8 He groundstate wave function.
Finally, note that recently in Dubna (Russia) the(p, t) reaction was investigated at a lower energy of the8
He beam, 26 A MeV, and also, a cross section for the
6He∗ (2+ ) channel higher than that for 6 Heg.s. was observed. Also, an indication on the 6 He(2+ ) + 2n configuration in the ground state of 8 He was previously
obtained in fragmentation of 8 He in the C target.2)
In summary, the p(8 He, t) reaction populating the
ground and excited 2+ state of 6 He was investigated.
The obtained results suggest a specific structure of theground state of 8 He containing the subsystem 6 He in
the 2+ state with a large weight.
References
1) M. V. Zhukov, A. A. Korsheninnikov, and M. H.
Smedberg: Phys. Rev. C 50, R1 (1994).
2) K. Markenroth, M. Meister, B. Eberlein et al.: Nucl.
Phys. A 679, 462 (2001).

Condensed from the article in Phys. Rev. Lett. 90, 082501(2003)
University of Surrey, UK
Joint Institute for Nuclear Research, Russia
Grand Accelerateur National D’Ions Lourds, FranceDépartement D’Astrophysique, de Physique des Particules,
de Physique Nucléaire et de L’Instrumentation Associée,FranceKurchatov Institute, Russia
Chalmers University of Technology and Göteborg University, Sweden

43

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of the vector analyzing power for the p + 6 He,
71 MeV/nucleon elastic scattering using
spin-polarized solid proton target
M. Hatano,∗1 T. Wakui,∗2 H. Sakai,∗1,∗2 T. Uesaka,∗2 A. Tamii,∗3 T. Kawabata,∗2 N. Aoi, H. Iwasaki,∗1
Y. Yanagisawa, T. Ohnishi, K. Sekiguchi, K. Yako,∗1 H. Okamura,∗4 N. Sakamoto, Y. Satou,∗5
K. Suda,∗6 Y. Maeda,∗1 T. Saito,∗1 H. Kuboki,∗1 K. Itoh,∗6 T. Ikeda,∗6 T. K. Onishi,∗1
M. Sasano,∗1 Y. Ichikawa,∗1 N. Matsui,∗5 and D. Suzuki∗1[polarized solid proton target, RI-beam experiment]
For our RI-beam experiments, we have constructed
a new spin-polarized solid proton target system. The
most signiﬁcant advantage of our target is its applicability in a low magnetic ﬁeld of 100 mT and at liquid N2 temperature. In July 2003, the ﬁrst experiment using the RI-beam, that is, a vector analyzing
power (Ay ) measurement in p + 6 He elastic scattering
at 71 MeV/nucleon, was carried out. The measured
angular region was 40◦ to 75◦ in the center-of-masssystem. The aim was to determine the spin-orbit potential between protons and 6 He. In this paper, an
overview of the experiment is reported.
As a target material, we used a single crystal ofnaphthalene (C10 H8 ). Protons in the naphthalene
crystal were polarized by means of a pulsed dynamic
nuclear polarization method.1,2) For details regarding
the proton polarizing system see Refs. 3 and 4.
The experiment was performed using RIPS at the
RIKEN Ring Cyclotron Facility. The 6 He beam
was produced by a fragmentation reaction of a 12 C
beam with an energy of 92 MeV/nucleon penetrating
a 1.39 g/cm2 Be target. The energy of the 6 He beam
was degraded by an aluminum degrader with a thickness of 0.32 g/cm2 to an energy of 71 MeV/nucleon.
The purity of the secondary beam was 95%, and theintensity was 170 kcps on average.
The secondary beam bombarded the polarized proton target with a thickness of 113 mg/cm2 . The target
was placed approximately 1 m downstream of the F3
focal point.
To detect leading particles (mainly 6 He), we used
a forward-counter placed approximately 1 m downstream of the target. The forward-counter consisted ofa multiwired drift chamber (MWDC) and three layersof plastic scintillator hodoscopes placed downstream of
the MWDC. The MWDC was used to measure the trajectory of the leading particles. The plastic scintillator
hodoscopes were used to identify the leading particle
with the standard ∆E-E method.
∗1
∗2
∗3
∗4
∗5
∗6

44

University of Tokyo
Center for Nuclear Study, University of Tokyo
Research Center for Nuclear Physics, Osaka University
Tohoku University
Tokyo Institute of Technology
Saitama University

To detect recoil protons, a pair of backward-counters
was used. One was for the left-hand event and theother was for the right-hand event. Each counter consisted of two 5-mm strip silicon detectors (X-PSD, YPSD) and plastic scintillators. The PSDs were set
perpendicular to each other and used to obtain twodimensional-position information on recoiled particles.
The particle identiﬁcation of recoiled particles were
performed with the ∆E information from the PSDs
and E information from plastic scintillators. To discriminate background events scattered, 6 He particles
and recoiled protons were detected in coincidence. In
such a coincidence detection, one can select the elastic scattering events only by identifying the 6 He particles at the forward-counter, since 6 He does not have abound excited state.
Figure 1 shows the asymmetry of p + 6 He elastic
scattering events measured at 40◦ in the center-of-masssystem. The horizontal axis corresponds to the angleof scattered 6 He particles. Figure 1 (a) and (b) showsummaries of the data when the proton polarization
was “UP” and “DOWN” respectively. The data analysis to deduce Ay and the diﬀerential cross section is
now in progress.
(a)

(b)

Fig. 1. Asymmetry measured at 40◦ in the center-of-masssystem. (a) when the proton polarization was “UP”.
(b) when the proton polarization was “DOWN”.

References
1) A. Henstra et al.: Phys. Lett. A 134, 134 (1988).
2) M. Iinuma et al.: Phys. Rev. Lett. 84, 171 (2000).
3) M. Hatano et al.: RIKEN Accel. Prog. Rep. 36, 48(2003).
4) T. Wakui et al.: RIKEN Accel. Prog. Rep. 37, 181(2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Experimental test of Bell’s inequality via the (d, 2 He) reaction
T. Saito,∗1 H. Sakai,∗1,∗2 T. Ikeda,∗3 K. Itoh,∗3 T. Kawabata,∗2 H. Kuboki,∗1 Y. Maeda,∗1 N. Matsui,∗4
M. Sasano,∗1 Y. Satou,∗4 K. Sekiguchi, K. Suda,∗3 A. Tamii,∗5 T. Uesaka,∗2 and K. Yako∗1Bell’s inequality, (d, 2 He) reaction
Since the discovery of Bell’s inequality (BI),1) many
experiments have been performed up to now to verify the violation of BI and to establish the correctness of the quantum mechanical description of nature.
It should be noted that, even though BI was originally derived from a consideration on correlation of
two spin 12 particles in a spin singlet (1 S0 ) state, mostof the experiments performed so far have employedpolarization-correlation of two photons.
The only one exception using spin 12 particles isthe experiment by Lamehi-Rachti and Mittig (LRM).2)
LRM measured spin-correlations of proton pairs produced by 13.5 MeV pp-elastic S-wave scattering. Although their results agreed with quantum mechanics
and violated the classical limits of BI, There are someproblems in their estimation of the systematic errors.
The incident proton energy is so high that their estimation of eﬀects by the mixture of the spin triplet
states in the ﬁnal two protons is not suﬃcient.
We are planning to test BI by measuring spincorrelation of proton pairs produced by the (d, 2 He)
reaction. Here we deﬁne a 2 He as a pair of protons
coupled in the 1 S0 state by the ﬁnal state interaction.
Use of (d, 2 He) reaction has following advantages: (1)In the case of LRM’s experiment, the relative energyof the two protons was ﬁxed kinematically, while the(d, 2 He) reaction enables us to select as small relative
energy as possible. Hence we can produce high purityof 1 S0 -state proton pairs. (2) Since the kinetic energyof the protons in the laboratory frame is high, the proton polarizations can be measured easily.
We have performed experiments at RIKEN in 2003.
We measured the 1 H(d, 2 He)n reaction at 270 MeV.
The beam was injected into a liquid hydrogen target3)of 70 mg/cm2 thick. 2 He scattered at 0◦ were momentum analyzed by a spectrometer SMART and detectedwith a proton polarimeter EPOL placed at the second focal plane of SMART. Typical beam intensity was
0.3 nA and we detected 2 He at the rate of 1–1.5 kcps.
An example of the energy spectrum is shown in Fig. 1.
A schematic view of EPOL is presented in Fig. 2.
EPOL consists of three multi-wire drift chambers(MWDCs), two sets of plastic scintillator hodoscopes
and an analyzer target (5.0 cm thick carbon block).
∗1
∗2
∗3
∗4
∗5

Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
Department of Physics, Saitama University
Course of Fundamental Physics, Tokyo Institute of Technology
Research Center for Nuclear Physics, Osaka University

Fig. 1. Typical excitation energy spectrum of 1 H(d, 2 He)nreaction at Ed = 270 MeV.

Fig. 2. Schematic view of the proton polarimeter EPOL.

The incident pairs of protons are simultaneously scattered from the analyzer target. By measuring theleft-right asymmetry of the scattering for each proton,spin-correlation function Π(a, b) = < σ1 · a σ2 · b >can be derived, where a and b are the direction of thereference axes of the spin measurement, and σ1 and σ2
are the Pauli matrices of each proton. If the angle between the two axes a and b is 45◦ , quantum mechanicalprediction is |ΠQM (45◦ )| = √12 , whereas the classicallimit by BI is |ΠBI (45◦ )| ≤ 12 . Thus, the violation ofBell’s inequality can be tested.
We have obtained data enough to verify the violationof Bell’s inequality by ﬁve standard deviations. Data
analysis is now in progress.
References
1) J. S. Bell: Physics 1, 195 (1964).
2) M. Lamehi-Rachti and W. Mittig: Phys. Rev. D 14,2543 (1976).
3) T. Ikeda et al.: RIKEN Accel. Prog. Rep. 37, 82 (2004).

45

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Spectroscopy of 13 B via 4 He(12 Be,13 Bγ)
S. Ota,∗1 S. Shimoura,∗2 H. Iwasaki,∗3 M. Kurokawa, S. Michimasa,∗2 S. Kubono,∗2 T. Teranishi,∗2
M. Notani,∗2 M. Tamaki,∗2 T. Murakami,∗1 N. Iwasa,∗4 T. Motobayashi, Y. Yanagisawa, T. Minemura,
S. Takeuchi, T. Gomi,∗5 K. Yamada,∗5 A. Saito,∗5 H. Baba,∗5 Y. U. Matsuyama,∗5 S. Kanno,∗5
E. Takeshita,∗5 K. Demichi,∗5 K. Hasegawa,∗5 K. Kurita,∗5 H. Sakurai,∗3 N. Aoi, E. Ideguchi,∗2
A. Odahara,∗6 T. Fukuchi,∗2 K. Miller,∗7 Z. Elekes, and M. Ishihara

NUCLEAR REACTION, 4 He(12 Be,13 Bγ), transfer reaction, in-beam γ-ray spectroscopy
The disappearance of regular magic numbers inneutron-rich nuclei has been one of the most interesting phenomena. Focusing on the N = 8 magicity, we
have studied 13 B, where the spins even for low-lying
states have not been assigned.1–4)
We measured the diﬀerential cross section of the
proton transfer reaction 4 He(12 Be,13 Bγ), which is expected to populate the proton single particle state. We
assigned the spin and parity of the highest bound excited state for the ﬁrst time.
The experiment was performed at RIPS beam line in
RIKEN. A primary beam of 18 O at 100 MeV/nucleon
bombarded a 1.85 g/cm2 -thick 9 Be target. A secondary beam of 12 Be was produced as the fragment
and separated by the RIPS. Its intensity and energy were 2 × 105 particles/s and 50 MeV/nucleon,
respectively. The 12 Be was identiﬁed event-by-event
via a TOF-∆E method with two plastic scintilatorsand bombarded a 120 mg/cm2 -thick liquid helium target. Outgoing particles were measured by a hodoscope
which consists of 13-∆E and 16-E plastic scintillatorsand identiﬁed by the TOF-∆E-E method. The TOF
was the ﬂight time between the target and a ∆E plastic scintillator.
Excited states in 13 B were identiﬁed by de-excitation
γ rays, which were detected by an array of segmentedGe detectors5) and the DALI (II) system.6) The array of segmented-Ge consists of six segmented-Ge detectors located 140 degrees to the beam direction.
The DALI (II) system consists of 75 NaI (Tl) detectors at forward angles. The detection eﬃciencyof Ge detectors was 0.17% for the 1.332-MeV γ rayfrom 60 Co source and that of DALI (II) was 9.8%
for the 661.6-keV γ ray from 137 Cs source. The energy resolutions of Ge detectors and the DALI (II)system, were 16 keV (σ) and 55 keV (σ) respectively,
for the Doppler-corrected 2.1-MeV γ ray from moving(β ∼ 0.3) 12 Be.
The diﬀerential cross section of the 4 He(12 Be,13 Bγ)
reaction for the 4.8-MeV excited state of 13 B is indi∗1
∗2
∗3
∗4
∗5
∗6
∗7

46

Department of Physics, Kyoto University
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Department of Physics, Tohoku University
Department of Physics, Rikkyo University
Nishinihon Institute of Technology
Michigan State University, USA

cated by closed circles in Fig. 1. Three curves wereobtained by zero-range DWBA calculations with assumptions of transfer angular momenta l = 0, 1, and
2. The set of optical potentials7,8) used in the calculation is listed in Table 1. The experimental angular
distribution is ﬁtted with the DWBA calculation withl = 0, which indicates that the transfered angular momentum was l = 0. Since the ground state of 12 Be
is 0+ , we assigned J π = 1/2+ to the 4.8-MeV excitedstate. Further analysis is in progress.

Fig. 1. Diﬀerential cross section of 4 He(12 Be,13 Bγ) reaction.
Table 1. Optical potentials used in DWBA calculations.
(a: 4 He+12 C7) , b: 3 He+12 C8) )

a
b

V0
(MeV)
75.680108.47

rV
(fm)
1.277
1.020

aV
(fm)
0.728
0.828

W0
(MeV)
13.88018.483

rW
(fm)
1.885
1.171

aW
(fm)
0.425
0.594

References
1) F. Ajzenberg-Selove et al.: Phys. Rev. C 17, 1283
(1978).
2) V. Guimarães et al.: Phys. Rev. C 61, 064609 (2000).
3) N. Aoi et al.: Phys. Rev. C 66, 014301 (2002).
4) R. Kalpakcieva et al.: Eur. Phys. J. A 7, 451 (2000).
5) S. Shimoura et al.: CNS Annu. Rep. 2001, 5.
6) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 36, 148(2003).
7) A. Ingemarsson et al.: Nucl. Phys. A 676, 3 (2000).
8) A. Ingemarsson et al.: Nucl. Phys. A 696, 3 (2001).

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RIKEN Accel. Prog. Rep. 37 (2004)

11

C(p,γ)12 N reaction studied
by the Coulomb dissociation method
T. Minemura, T. Motobayashi, S. Shimoura,∗1 H. Murakami,∗2 Y. Ando,∗2 Y. Yanagisawa, Y. Iwata,∗3
S. Ozawa, S. Takeuchi, Y. Higurashi, K. Yamada,∗2 T. Gomi,∗2 M. Serata,∗2 H. Kobayashi,∗2 T. Teranishi,∗1
N. Aoi, M. Hirai,∗4 H. Iwasaki,∗4 N. Imai, N. Iwasa,∗5 M. Uesaka, H. Akiyoshi, Zs. Fülöp,∗6 H. Sakurai,∗4
K. Yoshida, Z. Liu,∗7 and M. Ishihara

NUCLEAR REACTIONS: 208 Pb(12 N,11 C p)208 Pb, Coulomb dissociation
The importance of the radiative capture reaction,
C(p,γ)12 N, at low energies has been discussed in connection with an astrophysical nuclear burning process
called the hot pp chain.
There are two resonant states in 12 N of astrophysical interest: the ﬁrst excited state with J π = 2+
at Eex = 0.960 MeV, and the second one with 2− at
1.19 MeV. In terms of astrophysical implications, themost important property is the radiative width (Γγ ) of
the 1.19 MeV state.
Experiments have been performed at RIKEN using
the secondary beam line, RIPS. A 77.0 MeV/nucleon
12
N radioactive beam was produced through a fragmentation reaction of a primary 135 MeV/nucleon 16 O
beam. A 30 mg/cm2 208 Pb target was bombarded by asecondary 12 N beam. Protons and 11 C produced in the12
N dissociation were detected by a plastic-scintillator
hodoscope with an active area of 1×1 m2 located 5.1 m
downstream of the target. The energy of the fragment
was determined by its measured mass and the velocity obtained from the TOF. The complete kinematicsof the reaction products, the total energy and relative
momentum vector of the p+11 C system were thus fully
determined. To measure γ rays emitted from excitedstates of 11 C in the channel of 12 N → p+11 C∗ , a γray detector system called DALI (Detector Assemblyfor Low Intensity radiation), consisting of 64 NaI(Tl)scintillators, was placed around the target.
Figure 1 (a) shows the comparison between theexperimental relative energy spectrum for the
11
C(p,γ)12 N reaction and the calculation considered
E1 interference eﬀect. The two resonants and nonresonant contributions are plotted separately. The direct
capture cross section for the E1 transition has been
calculated using the direct capture component of the
ANC measurement result.1) The bump observed ataround 0.6 MeV by the experimental relative-energy
spectrum is mainly due to the E1 excitation of 12 N
from the 1+ ground state to the 2− state at Eex =
11

∗1
∗2
∗3
∗4
∗5
∗6
∗7

Fig. 1. (a) Comparison between relative energy and E1 interference eﬀect. (b) Reaction rate for the 12 N(p,γ)11 C
reaction.

1.19 MeV. The present result (Γγ = 13.0 ± 0.5 meV)considered E1 interference eﬀect is consistent with thatof the Coulomb dissociation experiment at GANIL2)(Γγ = 6+7
−3.5 meV), but the accuracy is markedly improved. Also, the E1 interference eﬀect was not considered in the GANIL result. The radiative width measured in the present experiment is in between the two
diﬀerent predictions by Wiescher et al.3) (Γγ = 2 meV)and Descouvemont and Baraﬀe4) (Γγ = 45 or 49 meV).
The 11 C(p,γ)12 N reaction rate is shown in Fig. 1 (b).
The solid curve is our updated reaction rate summed
for direct capture and second resonance. The dottedcurve is from Tang et al.,1) and the dash-dotted line is
the result treated as noninterfering in Ref. 2.
References
1) X. Tang et al.: Phys. Rev. C 67, 015804 (2003).
2) A. Lefebvre et al.: Nucl. Phys. A 592, 69 (1995).
3) M. Wiescher et al.: Astrophys. J. 343, 352 (1989).
4) P. Descouvemont et al.: Nucl. Phys. A 646, 261 (1999).

Center for Nuclear Study, University of Tokyo
Rikkyo University
National Institute of Radiological Sciences
University of Tokyo
Tohoku University
ATOMKI, Hungary
Institute of Modern Physics, China

47

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RIKEN Accel. Prog. Rep. 37 (2004)

Molecular states in 12 Be and 14 Be
A. Saito,∗1 S. Shimoura,∗2 S. Takeuchi, T. Motobayashi, T. Minemura, Y. U. Matsuyama,∗1 H. Baba,∗1
H. Akiyoshi, Y. Ando,∗1 N. Aoi, Zs. Fülöp,∗3 T. Gomi,∗1 Y. Higurashi, M. Hirai,∗4 K. Ieki,∗1 N. Imai,
N. Iwasa,∗5 H. Iwasaki,∗6 Y. Iwata,∗4 S. Kanno,∗1 H. Kobayashi,∗1 S. Kubono,∗2 M. Kunibu,∗1 M. Kurokawa,
Z. Liu, S. Michimasa,∗2 T. Nakamura,∗7 S. Ozawa, H. K. Sakai,∗1 H. Sakurai,∗6 M. Serata,∗1 E. Takeshita,∗1
T. Teranishi,∗2 K. Ue,∗2 K. Yamada,∗1 Y. Yanagisawa, and M. Ishihara

NUCLEAR REACTIONS: 12 C(14 Be, 6 He+6,8 He)X, 4 He(12 Be, 6 He+6 He)4 He
Excited states in neutron-rich beryllium isotopes
were investigated using radioactive beams of 14 Be
and 12 Be to bombard carbon and liquid helium targets, respectively. The invariant-mass method and theangular-correlation techniques were employed to measure the excitation energies and spins of excited states
above the 6 He+6 He and 6 He+8 He thresholds in 12 Be
and 14 Be, respectively. The details of the 14 Be+12 C
experiment are described in Ref. 1.
Figure 1 (a) shows the decay energy spectrum of6
He+6 He in the two-neutron removal reaction of the
14
Be beam on the 12 C target. Two peaks were observed at 1.7 MeV and 2.7 MeV, which correspond to
11.8 MeV and 12.8 MeV, respectively, in addition to
known levels at 14.9 MeV and 16.1 MeV.2) The spectrum was considered to include a large contributionof the continuum background. Therefore it is diﬃcult to apply the angular correlation techniques for theobserved peaks to determine the spins of the excitedstates. Inelastic scattering of the 12 Be beam on the liquid helium target was performed to obtain more precise
information on the highly excited states in 12 Be.
The experiment was carried out at RIPS in the
RIKEN Accelerator Research Facility. The secondary
beam of 12 Be at 60 A MeV was produced by a fragmentation reaction of the 18 O beam at 100 A MeV
on a beryllium target. The average intensity of thesecondary beam was 3 × 104 particles per second. The
thickness of the secondary target was 250 mg/cm2 . Reaction products of helium isotopes were measured andidentiﬁed using a hodoscope of a plastic scintillator array with an active area of 1 × 1 m2 placed 3.9 m downstream of the secondary target.
Figure 1 (b) shows the decay energy spectrum of6
He+6 He in the 12 Be+4 He reaction. Two strong peaks
are seen at 0.8 MeV and 1.2 MeV, which were not identiﬁed in Fig. 1 (a), in addition to the weak bump

∗1
∗2
∗3
∗4
∗5
∗6
∗7

48

Department of Physics, Rikkyo University
Center for Nuclear Study, University of TokyoATOMKI, Hungary
National Institute of Radiological Science
Department of Physics, Tohoku University
Department of Physics, University of Tokyo
Department of Physics, Tokyo Institute of Technology

Fig. 1. Decay energy spectra of 12 Be∗ → 6 He+6 He in the(a) 14 Be+12 C and (b) 12 Be+4 He reactions.

at approximately 1.7 MeV. The peak at 2.7 MeV in
Fig. 1 (a) is not seen in Fig. 1 (b). To determine thespins of these levels, the analyses of angular distribution of the excited 12 Be are in progress.
References
1) A. Saito et al.: RIKEN Accel. Prog. Rep. 35, 55 (2002);
RIKEN Accel. Prog. Rep. 36, 62 (2003).
2) M. Freer et al.: Phys. Rev. Lett. 82, 1383 (1999).

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RIKEN Accel. Prog. Rep. 37 (2004)

Isomeric 0+ state in 12 Be†
S. Shimoura,∗1 A. Saito,∗2 T. Minemura, Y. U. Matsuyama,∗2 H. Baba,∗2 H. Akiyoshi, N. Aoi, T. Gomi,∗2
Y. Higurashi, K. Ieki,∗2 N. Imai, N. Iwasa,∗3 H. Iwasaki,∗1 S. Kanno,∗2 S. Kubono,∗1 M. Kunibu,∗2
S. Michimasa,∗1 T. Motobayashi, T. Nakamura,∗4 H. Sakurai,∗5 M. Serata,∗2 E. Takeshita,∗2
S. Takeuchi, T. Teranishi,∗1 K. Ue,∗1 K. Yamada,∗2 Y. Yanagisawa,
M. Ishihara, and N. Itagaki∗5[Isomeric state, γ-γ correlation, Radioactive beam experiment]
An isomeric 0+ state in 12 Be was found at Ex =2.24 MeV. The isomer was identiﬁed by measuring two
coincident γ-rays from an in-ﬂight 12 Be nucleus, produced by the projectile fragmentation of 18 O on a Be
target at 100 A MeV. Its spin was determined to be 0+
by the angular correlation of the two γ-rays.
The experiment was performed at the RIKEN Accelerator Research Facility. A primary beam of 18 O
projectiles at 100 A MeV bombarded a 2-g/cm2 -thick
Be target. The 12 Be(∗) nuclides at 60 A MeV were selected by the RIKEN Projectile Fragment Separator(RIPS).1) Two plastic scintillators at the second (F2)and third (F3) focal points of the RIPS were used for
identifying the 12 Be event by event using the timeof-ﬂight (TOF) between the two scintillators and thepulse heights. Gamma rays were detected by an arrayof 68 NaI(Tl) scintillators (DALI) about 70 cm downstream of the F3 scintillator. Timing signals of NaI(Tl)were used to discriminate the true coincidence from theaccidental one, and to evaluate the vertex point fromwhich the γ-ray was emitted. The vertex point wasused for Doppler-shift corrections event by event. The
12
Be nucleus after decay was detected by a plastic scintillator hodoscope with a 1 × 1 m2 active area located
4 m downstream of DALI. The hodoscope consisted ofa 5-mm-thick ∆E plane and a 60-mm-thick E plane.
We analyzed events where two NaI(Tl) scintillators made signals from in-ﬂight 12 Be particles. After the Doppler-shift correction, we found a new
0.14 MeV transition coincident with the 2.1 MeV transition (2+ → 0+
1 ), resulting in a new state at about
0.14 MeV above the 2+ state, i.e., an isomeric state at
Ex = 2.24 MeV.
In order to determine the spin of the new state,
we have examined an azimuthal angular correlation

†
∗1
∗2
∗3
∗4
∗5

of these two γ’s with respect to the direction of the
12
Be momentum. Figure 1 shows the observed angular correlation together with a theoretical prediction++
assuming a cascade decay of 0+
2 → 21 → 01 . We
conclude the isomeric state has spin 0+ based on the
excellent ﬁt.
We also observed coincident 0.51 MeV γ-rays originated from the annihilation of positrons, which are to+
be produced in the e+ e− pair decay of the 0+
2 → 01transition. From the relative yields of the 0.14 MeV
and 0.51 MeV γ-rays, the branching ratio of the
+
+
+
+
0+
2 → 2 → 01 and 02 → 01 transitions are deduced
to be (83 ± 2)% and (17 ± 2)%, respectively.

Fig. 1. Azimuthal angular correlation pattern of 2.1 MeV
and 0.14 MeV γ-rays. The solid line denotes the theoretical prediction assuming the 0+ → 2+ → 0+ transition.

References
1) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).

Condensed from the article in Phys. Lett. B 560, 31 (2003)
Center for Nuclear Study, University of Tokyo
Department of Physics, Rikkyo University
Faculty of Science, Tohoku University
Department of Applied Physics, Tokyo Institute of Technology
Department of Physics, University of Tokyo

49

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RIKEN Accel. Prog. Rep. 37 (2004)

Coulomb and nuclear breakup of 11 Li
A. M. Vinodkumar,∗1 T. Nakamura,∗1 N. Fukuda, T. Sugimoto,∗1 M. Miura,∗1 Y. Kondo,∗1 T. Kobayashi,∗2
N. Aoi, N. Imai, T. Kubo, T. Gomi,∗3 A. Saito,∗3 H. Sakurai,∗4 S. Shimoura,∗5 D. Bazin,∗6
H. Hasegawa,∗3 H. Baba,∗3 T. Motobayashi, T. Yakushiji,∗2 Y. Yanagisawa,
K. Yoneda,∗6 K. Watanabe,∗2 Y. X. Watanabe,∗7 and M. Ishihara

NUCLEAR REACTIONS: 12 C(11 Li, 9 Li nX), Nuclear breakup
11

Li is one of the two neutron halo nuclei extensively studied for Coulomb dissociation experimentally and theoretically.1–6) However, these measurements and theories were not able to provide a conclusive picture regarding the structure of 11 Li as wellas the reaction mechanism involved. 11 Li Coulomb
and nuclear dissociation has been investigated by Ieki
et al.1,2) (MSU data), Shimoura et al.3) (RIKEN data),
and Zinser et al.4) (GSI data), at 28 A MeV, 43 A MeV
and 280 A MeV, respectively. The B(E1) distributions
derived from these three measurements shows discrepancies among each other. The GSI data shows a secondbump at approximately 2.5 MeV in the B(E1) distribution. However, RIKEN data do not show such a bump.
In this preliminary report, we present the analysis of
9
Li in coincidence with one neutron produced in the
breakup on a carbon target.
We have carried out a kinematically complete experiment using the RIPS spectrometer at RIKEN. A 11 Li
secondary beam of 70.34 A MeV energy bombarded
lead and carbon targets of 347 mg/cm2 thickness and377 mg/cm2 thickness respectively. The time of ﬂightof the beam was measured using a thin plastic detector at the achromatic focus and the RF signal. The
fragment was bent by a large acceptance dipole magnet and traced using a drift chamber and hodoscopes(7 numbers). The momentum vectors of the fragment
were reconstructed from the time of ﬂight and tracking
information. The neutrons were detected using 4 wallsof plastic scintillators. The intrinsic eﬃciency and conditions for eliminating crosstalk events were obtained
from a separate experiment in which we used a proton
beam (7 Li(p, n) reaction). The experimental details
are presented in a previous report.7)
The invariant mass spectrum of the 10 Li is reconstructed from the momenta of the charged particle andneutron. In Fig. 1, the relative energy between 9 Li and

∗1
∗2
∗3
∗4
∗5
∗6
∗7

50

Tokyo Institute of Technology
Department of Physics, Tohoku University
Department of Physics, Rikkyo University
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
Michigan State University, USA
High Energy Accelerator Research Organization (KEK)

Fig. 1. The two body relative energy spectra obtained in
the 11 Li + C → 9 Li + n + X reaction.

one neutron (invariant mass spectra of 10 Li) obtainedusing a carbon target is shown. In the relative energy
spectra, at close to zero relative energy, more strength
was observed compared with the GSI measurement.
Presently we are investigating the physical signiﬁcanceof this low-energy strength. Also the analysis of the 9 Liin coincidence with two neutrons is in progress.
References
1) K. Ieki et al.: Phys. Rev. Lett. 70, 730 (1993).
2) D. Sackett et al.: Phys. Rev. C 48, 118 (1993).
3) S. Shimoura et al.: Phys. Lett. B 348, 29 (1995).
4) M. Zinser et al.: Nucl. Phys. A 619, 151 (1997).
5) T. Kobayashi et al.: Phys. Lett. B 232, 51 (1989).
6) I. J. Thompson and M. V. Zhukov: Phys. Rev. C 49,
1904 (1994).
7) T. Nakamura et al.: RIKEN Accel. Prog. Rep. 35, 57(2002).

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RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of reaction cross section for 17 C and finite-range
Glauber model analysis
C. Wu,∗1 Y. Yamaguchi,∗2 A. Ozawa,∗3 R. Kanungo, T. Suzuki,∗4 D. Q. Fang,
T. Suda, T. Ohnishi, M. Fukuda,∗5 N. Iwasa,∗6 T. Ohtsubo,∗2 T. Izumikawa,∗2
R. Koyama,∗2 W. Shinozaki,∗2 M. Takahashi,∗2 and I. Tanihata
17
C, reaction cross section σR , density distribution, ﬁnite-range Glauber Model

The reaction cross sections σR at low energies havebeen proved to be more sensitive to the nuclear density
at the surface because of large neucleon-neucleon total
cross sections. Like 8 B, although measurements of theinteraction cross section σI at relativistic energies did
not show signiﬁcant enhancement, measurements of σR
at low energies revealed the necessity of a long proton
tail.1) Motivated by this, we measured σR of 17 C at
79 A MeV by the transmission method. The density
distribution of 17 C has been investigated by ﬁtting thepresent result of σR and previous experimental data ofσI 2) using the Glauber model.
The experiment was performed at RIPS of RIKEN.
Secondary 17 C beam was produced by projectile fragmentation of primary-beam 22 Ne at 110 A MeV on production target Be. Before the reaction target (carbon)
at F2, particle identiﬁcation was achieved by the standard Bρ − ∆E − TOF method, in which B was themagnetic ﬁeld of D2 , ∆E was the energy loss in F2SSD
and TOF was the time of ﬂight between F1PPAC and
F2Plastic. After the reaction target, the TOF−∆E−E
method was used to identify particles. TOF was thetime of ﬂight between F2Plastic and F3Plastic. ∆E
and E were energy loss in the IC (ion chamber) andtotal energy deposit in NaI(Tl), respectively. In addition, we used a set of veto detectors around NaI(Tl) to
detect the emitted charged particles or neutrons fromreactions in NaI(Tl).
To measure σR by the transmission method, thequantities of incident 17 C, Nin , and outgoing nonreacted 17 C, Nout , should be determined. In our work,
Nin was determined by particle identiﬁcation before
the reaction target. To determine Nout , the number ofother fragments, Nfrag (like 16 C, 15 C, 14 C), and that of
inelastic 17 C, Ninel , from reactions in the target weresubtracted from the total number of outgoing particles
with Z = 6. The present result of σR for 17 C is shownin Fig. 1(b) by the closed square.
The ﬁnite-range Glauber Model (FRGM)3) has been
employed to probe the density distribution of 17 C. All
results are shown in Fig. 1. We assumed that the density of 17 C was (1) HO density, the size parameter
∗1
∗2
∗3
∗4
∗5
∗6

Peking University, China
Niigata University
Tsukuba University
Saitama University
Osaka University
Tohoku University

(a)

(b)

Fig. 1. (a) Density distribution of 17 C. (b) Results of σR
and FRGM calculation.

αHO of which was obtained by ﬁtting σI at high energy, as shown by the dotted line; (2) a HO core anda Yukawa tail, in which αHO and the crossing radius
were the same as those of 16 C,3) as shown by the solidline; (3) core (16 C) plus single-particle density, assuming a mixture of s- and d-waves of the valence neutron.
A dominant d-wave (77 ± 21%) was found from thebest ﬁt shown by the dash line.
In conclusion, the existence of a tail in the density
distribution of 17 C is suggested to explain the large
reaction cross section data. Based on the assumptionof a core plus single-particle density, d-wave dominanceis favored in the best ﬁt, which is in agreement withother measurements.4,5)
References
1) M. Fukuda et al.: Nucl. Phys. A 656, 209 (1999).
2) A. Ozawa et al.: Nucl. Phys. A 691, 599 (2001).
3) T. Zheng et al.: Nucl. Phys. A 709, 103 (2002).
4) V. Maddalena et al.: Phys. Rev. C 63, 024613 (2001).
5) U. Datta Pramanik et al.: Phys. Lett. B 551, 63 (2003).

51

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RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of the reaction cross section for 17 B
Y. Yamaguchi,∗1 C. Wu,∗2 A. Ozawa,∗3 T. Suzuki,∗4 T. Ohnishi, T. Suda, M. Fukuda,∗5 D. Q. Fang,
R. Kanungo, N. Iwasa,∗6 T. Ohtsubo,∗1 T. Izumikawa,∗1 W. Shinozaki,∗1 R. Koyama,∗1
M. Takahashi,∗1 S. Watanabe,∗1 and I. Tanihata

NUCLEAR REACTIONS, 17 B, measured reaction cross section
The neutron-rich nucleus 17 B has been consideredas the two-neutron halo nucleus due to its weak binding energy of valence two-neutron,1) large r.m.s matterradius2) and narrow momentum distribution for 15 B
fragment from the breakup of 17 B.3) Therefore it isinteresting to study the nucleon density distributionof 17 B. In order to deduce the nucleon density distribution, we have measured the reaction cross section at
77A MeV by using a transmission method.
The experiment was performed at RIken Projectile
fragment Separator (RIPS).4) The primary beam of
22
Ne with 110 A MeV, accelerated by the RIKEN Ring
Cyclotron (RRC), was used to impinge on Be or Ta
targets to produce 17 B as the secondary beam throughthe projectile fragmentation reaction. The RIPS was
operated in an achromatic mode with an Al wedge degrader and the momentum acceptance of 1.0%. The
Particle IDentiﬁcation (PID) before the carbon reaction target (377 mg/cm2 ), which was placed at F2 of
RIPS, was performed by the Bρ-∆E-TOF standard
method for each of the fragments. Magnetic rigidity(Bρ) was determined by using the position informationof PPACs. The magnetic ﬁelds at the two dipoles weremonitored by NMR probes. The energy loss (∆E) was
measured by a silicon detector (50 × 50 × 0.15 mm3 )placed at F2. The Time-Of-Flight (TOF) information
before the reaction target was determined from therf -signal and the timing signal of the plastic scintillator (0.5 mm thickness) placed at F2. The backgroundcontamination of other particles was estimated to be10−4 in the oﬄine analysis. After the reaction target,a quadropole-triplet was used to transport and focus
the beam onto F3. The PID after the reaction target
was performed by the TOF-∆E-E method. The TOF
information was determined between the two plastic
scintillators at F2 and F3. The ∆E was measured by
the ion chamber5) which was placed at F3. The totalenergy (E) was measured by the 3 φ × 6 cm NaI(Tl)detector placed at the end of the beam line with a reaction suppressor.6)
The reaction cross section (σR ) for 17 B was calculated using the following equation,
∗1
∗2
∗3
∗4
∗5
∗6

52

Niigata University
Peking University, China
Tsukuba University
Saitama University
Osaka University
Tohoku University

1
σR = − ln
t



Rin
Rout


(1)

where t is the thickness of the reaction target in theunit of atom/cm2 , Rin and Rout are the ratios of thenumber of outgoing particles to that of the incident
particles with and without the reaction target, respectively. We did ﬁnd a large enhancement of σR for 17 B,
compared with that of the expected value by Kox’s formula calculation. Kox’s formula can reproduce the σRfor stable nuclei well.7) The ratios of the experimental
σR for 17 B to the expected value from Kox’s formula
are shown in Fig. 1. At low energy, the enhancement of
σR is much larger than that at high energy. This eﬀectsuggests the existence of a low-density tail at a large
distance from the center of the nucleus.
The nucleon density distribution of 17 B will be deduced by using the energy dependence of the measured
cross sections. The data analysis is still in progresswith Glauber-model calculation.

Fig. 1. The ratios of the experimental σR to the expectedvalue from Kox’s formula calculation for 17 B are plotted
as a function of the incident beam energy. The closed
circle denotes the data point obtained in this work. The
open square is obtained from Ref. 2.

References
1) G. Audi et al.: Nucl. Phys. A 624, 1 (1997).
2) T. Suzuki et al.: Nucl. Phys. A 658, 313 (1999).
3) T. Suzuki et al.: Phys. Rev. Lett. 89, 12501-1 (2002).
4) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).
5) Y. Yamaguchi et al.: RIKEN Accel. Prog. Rep. 36, 161(2003).
6) T. Suda et al.: RIKEN Accel. Prog. Rep. 35, 171 (2002).
7) S. Kox et al.: Phys. Rev. C 35, 35 (1987).

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RIKEN Accel. Prog. Rep. 37 (2004)

Mean lifetime of the first excited state in 16 C
N. Imai, H. J. Ong,∗1 N. Aoi, H. Sakurai,∗1 K. Demichi,∗2 H. Kawasaki,∗2 H. Baba,∗2 Zs. Dombrádi,∗3
Z. Elekes,∗3 N. Fukuda, Zs. Fülöp,∗3 A. Gelberg,∗4 T. Gomi,∗2 H. Hasegawa,∗2 K. Ishikawa,∗6 H. Iwasaki,∗5
E. Kaneko,∗2 S. Kanno,∗2 T. Kishida, Y. Kondo,∗6 T. Kubo, K. Kurita,∗2 S. Michimasa,∗5 T. Minemura,
M. Miura,∗6 T. Motobayashi, T. Nakamura,∗6 M. Notani,∗3 T. K. Onishi,∗1 A. Saito,∗2 S. Shimoura,∗5
T. Sugimoto,∗6 M. K. Suzuki,∗1 E. Takeshita,∗2 S. Takeuchi, M. Tamaki,∗5 K. Yoneda,∗7
H. Watanabe, and M. Ishihara

NUCLEAR REACTIONS: 9 Be(16 C, 16 C∗ )9 Be E = 34.6 MeV/u, RSM
We measured the mean lifetime of the ﬁrst excitedstate of 16 C using a new experimental technique. The
mean lifetime is directly related to the B(E2) value ofthe nucleus, which reﬂects the quadrupole collectivityof charge distribution in the nucleus.
The new technique essentially follows the concept of
the recoil shadow method (RSM),1) in which the emission point of the de-excitation γ-ray is located andthe γ-ray intensity is recorded as a function of theﬂight distance of the de-exciting nucleus. By utilizing an intermediate-energy radioactive-isotope beam,
the ﬂight velocity of the de-exciting nucleus is close
to half the light velocity even after the secondary reaction. With such a high velocity, the ﬂight distance over
100 ps corresponds to a macroscopic length of about
1.7 cm. The present shadow method provides a wide
range of applicability, extending to lifetimes of around
20 ps.
The beam of 16 C was produced by projectile fragmentation of a 100 MeV/u 18 O beam with a thick1850 mg/cm2 Be target. The 16 C beam was separated
by the RIPS beam line and bombarded onto a thick
370 mg/cm2 Be target. In the middle of the target,
the energy of the beam was 34.6 MeV/u. The typicalsecondary beam intensity was 200 kHz.
The de-excitation γ-rays from the inelastically excited 16 C nuclei were detected by an array of thirtytwo NaI(Tl) detectors. The array was divided into tworings, R1 and R2. R1 (R2) was composed of 14 (18)
NaI(Tl) detectors and was placed at 121 (102) degrees
from the center of the target position with respect tothe beam axis. In order to implement the RSM concept, we placed a lead slab of 5 cm-thickness just downstream of R2. The upstream surface of the lead slab
was deﬁned as z = 0.0 cm for later description. Dueto the screening eﬀect of this slab, eﬀective γ-ray eﬃciencies of R1 and R2 are diﬀerent. The magnitude ofthe diﬀerence depends on the point of γ-ray emission
∗1
∗2
∗3
∗4
∗5
∗6
∗7

University of Tokyo
Rikkyo University
ATOMKI, Hungary
University of Koeln, Germany
Center for Nuclear Study, University of Tokyo
Tokyo Institute of Technology
National Superconducting Cyclotoron Laboratory at Michigan State University, USA

along the beam axis. Thus, the mean lifetime can be
deduced from the γ-ray yield ratio (R1/R2).
The measurements were performed with two target
positions, z = 0.0 and 1.0 cm, to verify the deduced
mean lifetime. The R1/R2 ratios as a function of mean
lifetime τ are shown as solid lines in Fig. 1. These
functions were obtained by the Monte Carlo simulation. The simulation includes the measured emittanceof the beams and scattering angles, and the calculated
angular distribution of de-excitation γ-rays. The measured R1/R2 ratios are also presented in Fig. 1. From
the overlapped areas, the values of τ were determined
to be 92 ± 22 ps and 63 ± 17 ps, respectively, for dataobtained at the two target positions. As the ﬁnal value,
we adopted a weighted average of these two values.
The uncertainty mentioned above is attributed to statistical error. By adding systematic error quadratically, we determined τ = 77 ± 24 ps. The present mean
lifetime is anomalously long by an order of magnitude
compared with any predicted value. A paper whichsummarizes the present results has been submitted toPhysical Review Letters.

Fig. 1. Gamma-ray yield ratio of R1 to R2 as a functionof mean lifetime of 16 C(2+1 ). Hatched boxes indicate
the measured R1/R2 ratios for the two target positions,z = 0.0 and 1.0 cm. Dashed line indicates the meanvalue of the adopted τ , while dotted lines represent the
1-sigma error region.

References
1) H. Backe et al.: Z. Phys. A 285, 159 (1978).

53

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RIKEN Accel. Prog. Rep. 37 (2004)

In-beam gamma spectroscopy and search for isomeric states in 17,19 C
R. Kanungo, Z. Elekes,∗1 H. Baba,∗2 Zs. Dombrádi,∗3 Zs. Fülöp,∗3 J. Gibelin,∗2 A. Horvath,∗4 Y. Ichikawa,∗5
E. Ideguchi,∗6 N. Iwasa,∗7 H. Iwasaki,∗5 S. Kawai,∗2 Y. Kondo,∗8 T. Motobayashi, M. Notani,∗6 T. Ohnishi,
A. Ozawa,∗9 H. Sakurai,∗5 S. Shimoura,∗6 E. Takeshita,∗2 S. Takeuchi, I. Tanihata, Y. Togano,∗2 C. Wu,∗10
Y. Yamaguchi,∗11 Y. Yanagisawa, A. Yoshida, and K. Yoshida[gamma spectrocopy, proton inelastic scattering, isomer]
The study of unstable nuclei has become indispensible in recent times for nuclear structure studies. The
p-sd shell neutron-rich nuclei exhibit interesting features such as enhanced interaction cross section, whichsuggests the presence of some exotic structures.
It has been interesting to note that although the reaction observables such as the interaction cross section
and the longitudinal momentum distribution for one
neutron removal have been well understood for the pshell nuclei such as 11 Li and 11 Be, there exists someanomaly in understanding the ground state spin of thenucleus 19 C.1) Several experimental studies suggest anabnormal spin of 1/2+2,3) for this nucleus. However,
several attempts to measure the magnetic moment forthis nucleus has not yet yielded any conﬁrmation on
this spin assignment.4)
Recent investigations at GANIL showed an interesting observation of a prompt gamma transition at∼200 keV for 19 C.5) This triggered considerable interest since it corresponds to the de-excitation of a very
short-lived state. According to shell model calculations and single particle excitation estimates, a longlived state is expected as the ﬁrst excited state for 19 C
having a ground state spin 1/2+ . It thus became interesting to look for the existence of a low-lying isomericstate in 19 C. For a comparative study, we also investigated the nuclei 17 C and 17 B.
It was also necessary to have a re-conﬁrmation for
the existence of the 200 keV gamma transition througha diﬀerent method of excitation. Since the threshold in the GANIL measurement was quite close to
200 keV, it was interesting to investigate the possibilities of prompt gamma transitions of lower energy.
Our experiment was directed towards these goals.
The experiment was designed to search for both theprompt gamma transition and gamma decay from theisomeric state simultaneously. The prompt gamma
detection was carried out by in-beam gamma spec-

troscopy where a secondary beam of 19,17 C was excitedthrough proton inelastic scattering (p,p ) from liquid
H2 target.
The experimental setup is schematically shown in
Fig. 1. The secondary beam of 19,17 C was producedby fragmentation of a 22 Ne primary beam with a
1.864 gm/cm2 Be target. 17 B was retained as a contaminant fragment in the 19 C setting. The secondary
beam after scattering from a liquid H2 target was identiﬁed and stopped in a stack of silicon detectors. The
prompt gamma transitions from the excited states ofthe secondary beam, populated by inelastic (p,p ) scattering, were detected by an array of NaI(Tl) detectors surrounding the H2 target. The threshold was
20–40 keV.
To detect gamma rays from the possible isomerictransition, germanium clover detectors were placedoutside the plastic scintillators. For the same purpose, NaI(Tl) crystals were placed at 0o to the beam.
Beta rays from decay of 17,19 C ground state were detected by plastic scintillators surrounding the silicon
stack for reducing the background in the gamma-ray
detectors. The time gate for detection of isomeric transition was 500 µsec. The gamma energy threshold wasset ∼30 keV to focus on low-lying excited states.
A discussion on some preliminary observations for(p,p ) is reported in Ref. 6. Further analysis of experimental results is in progress.

Fig. 1. Schematic figure of the experimental setup.

∗1

References∗21) R. Kanungo et al.: Nucl. Phys. A 677, 171 (1998).
2) V. Maddalena et al.: Phys. Rev. C 63, 024613 (2001).
3) T. Nakamura et al.: Phys. Rev. Lett. 83, 1112 (1999).
4) K. Asahi et al.: private communication.
5) M. Lewitowicz: Nucl. Phys. A 722, 67c (2003).
6) Z. Elekes et al.: RIKEN Accel. Prog. Rep. 37, 61 (2004).

On leave from ATOMKI, Hungary
Department of Physics, Rikkyo University∗3 Institute of Nuclear Research, ATOMKI, Hungary∗4 Eotvos Lorand University, Hungary∗5 Department of Physics, University of Tokyo∗6 Center for Nuclear Study, University of Tokyo∗7 Department of Physics, Tohoku University∗8 Department of Physics, Tokyo Institute of Technology∗9 Institute of Physics, University of Tsukuba∗10 Peking University, China∗11 Niigata University

54

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RIKEN Accel. Prog. Rep. 37 (2004)

In-beam γ-ray spectroscopy of Ne isotopes
K. Ishikawa,∗1 J. Gibelin,∗2 K. Yoshida, T. Nakamura,∗1 D. Beaumel,∗2 N. Aoi, H. Baba,∗3 Y. Blumenfeld,∗2
Z. Elekes, N. Fukuda, T. Gomi,∗3 Y. Kondo,∗1 A. Saito,∗3 Y. Satou,∗1 E. Takeshita,∗3 S. Takeuchi,
T. Teranishi,∗4 Y. Togano,∗3 V. Lima,∗2 Y. Yanagisawa, A. M. Vinodkumar,∗1
T. Kubo, and T. Motobayashi

NUCLEAR REACTIONS, Al(26 Ne, 26−x Ne∗ ), Pb(26 Ne, 26−x Ne∗ ), in-beam γ-ray spectroscopy, Coulomb dissociation
We performed the study of the low-lying E1 strengthof the neutron-rich 26 Ne nucleus by using the Coulomb
dissociation and excitation reactions. The dipole
strength is expected to be much more fragmented below the giant dipole resonance region.1) In the caseof 26 Ne, the low-lying excitation is suggested to bea pygmy of the giant dipole resonance. In this report,
we present a preliminary result of the Coulomb excitation part in which we search for such resonance below
the one-neutron emission threshold.
The experiment was performed at RIKEN Projectilefragment Separator RIPS. The primary beam of 40 Ar
at 95 MeV/nucleon bombarded a 2-mm-thick Be target to produce the secondary beam of 26 Ne. The average intensity and purity of the 26 Ne beam were about
6 kcps and 80%, respectively, with 58 MeV/nucleon
just before the reaction target. The secondary beam
was identiﬁed through energy loss and time-of-ﬂight
measurements. The scattering angles of incoming particles were determined by two PPAC’s located upstream of the reaction target. Pb and Al targets having thicknesses of 230 mg/cm2 and 130 mg/cm2 , respectively, were used for estimating the Coulomb andnuclear excitation components. Particle identiﬁcationof the fragments passing through the target was performed using four-layer Si strip detectors composed of∆E and E counters located at about 1.2 m downstreamof the target. The ﬁrst two layers were composed of
8 Si detectors which were used for position detection.
The position and intrinsic energy resolution of ∆E
counters were 5 mm and 2% (FWHM), respectively.
The last two layers were the E counter composed of
8 Si(Li) detectors with 3 mm thickness, and an intrinsic energy resolution of 3% (FWHM). The neutrons
produced in the reaction were detected by the neutronwall. The neutron wall had 4 layers located 3 m downstream of the target. Each layer had 29 plastic scintillators. The analysis of the neutrons is not used here
and is reported elsewhere. The γ-rays emitted from

∗1
∗2
∗3
∗4

outgoing nuclei were detected by 152 NaI detectors,
DALI2. For 2 MeV γ-rays, the eﬃciency is calculated
to be around 10% with an intrinsic energy resolution
of 7% (FWHM).
A preliminary γ-ray spectrum for the 26 Ne + Pb reaction is shown in Fig. 1. The Doppler shift due tothe velocity of 26 Ne is corrected for. We have observed
a peak at 2020 keV corresponding to the excitation to
the ﬁrst 2+ state. The B(E2) of this transition waspreviously measured at MSU,2) so that we can use thisexcitation as a reference. Further analysis to extract
the E1 strength below the one-neutron threshold is
now in progress.

Fig. 1. Energy spectrum of Doppler-corrected γ-rays detected in coincidence with the 26 Ne ejectile. The peakat around 2020 keV is clearly seen.

References
1) A. Leistenschneider et al.: Phys. Rev. Lett. 86, 24(2001).
2) B. V. Pritychenko et al.: Phys. Lett. B 461, 322 (2001).

Department of Physics, Tokyo Institute of Technology
Institut de Physique Nuclaire, France
Department of Physics, Rikkyo University
Center for Nuclear Study, University of Tokyo

55

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RIKEN Accel. Prog. Rep. 37 (2004)

Excited states in 27 F
Z. Elekes,∗1 Zs. Dombrádi,∗2 A. Saito,∗3 N. Aoi, H. Baba,∗3 K. Demichi,∗3 Zs. Fülöp,∗2 J. Gibelin,∗4 T. Gomi,∗3
H. Hasegawa,∗3 N. Imai,∗5 M. Ishihara, H. Iwasaki,∗5 S. Kanno,∗3 S. Kawai,∗3 T. Kishida, T. Kubo,
K. Kurita,∗3 Y. U. Matsuyama,∗3 S. Michimasa,∗5 T. Minemura, T. Motobayashi, M. Notani,∗5 T. Ohnishi,∗5
H. J. Ong,∗5 S. Ota,∗6 A. Ozawa,∗7 H. K. Sakai,∗3 H. Sakurai,∗5 S. Shimoura,∗5 E. Takeshita,∗3 S. Takeuchi,
M. Tamaki,∗5 Y. Togano,∗3 K. Yamada,∗3 Y. Yanagisawa, and K. Yoneda

NUCLEAR STRUCTURE, Unstable nuclei, 27 F excited states
It is known that the last bound oxygen neutron-richnucleus is 24 O, while adding one more proton even the31
F is bound.1) A straightforward way of understanding this phenomena is to assume that the νd3/2 neutron orbit is unbound in oxygen isotopes, while theadditional proton in the ﬂuors can make bound thisstate. This assumption is enough to explain the existence of 27,29 F, but for understanding the bound natureof 31 F additional assumptions are needed. In terms ofshell model, sudden lowering of multiparticle multihole states may be an explanation.2) If this is valid, its
traces must be seen also in the ligter F isotopes. In 27 F
the ﬁrst excited state is expected to be unbound in the
usd 3) approximation, while allowing for particle-holeexcitations to the f p shell, a bound exicted state in27
F is expected. To search for such states we studied
the 27 F(p,p γ) reaction.
In the present experiment a 94 A MeV energy primary beam of 40 Ar with 60 pnA intensity hit a 181 Ta
production target of 0.5 cm thickness. The reaction
products were momentum and mass analyzed by the
RIPS4) fragment separator. The secondary beam inlcuded neutron-rich 24 O, 25,26,27 F, 27,28,29,30 Ne and29,30,31,32
Na nuclei. The RIPS was operated at 6%
momentum acceptance. The total intesity was about
100 cps having a 27 F intensity of 4 cps on average. The
identiﬁcation of incident beam species was performedby means of energy loss, time-of-ﬂight and magnetic
rigidity (Bρ).5) 27 F particles could be fully separated
from other nuclei. The secondary beam was transmitted to a liquid hydrogen target6) at the ﬁnal focus
of RIPS. The average areal density of the hydrogenwas 210 mg/cm2 . The position of the incident particles
was determined by two PPACs placed at F3 upstream
the target. The scattered particles were detected andidentiﬁed by a PPAC and a silicon telescope. The telescope consisted of three layers with thicknesses of 0.5,
0.5 and 1 mm. The Z identiﬁcation was performed by
TOF-energy loss method. Based on ∆E-E information
∗1
∗2
∗3
∗4
∗5
∗6
∗7

56

On leave from Institute of Nuclear Research, ATOMKI,
Hungary
Institute of Nuclear Research, ATOMKI, Hungary
Rikkyo University
Institut de Physique Nucléaire, France
University of Tokyo
Kyoto University
University of Tsukuba

isotope separation was carried out among the diﬀerent ﬂuorine isotopes. 27 F nuclei represented a distinct
peak and they were well separated from other products
emerged by neutron removal reactions in the liquid hydrogen target. The new DALI2 setup including 146
NaI(Tl) scintillator detectors,7) surrounded the target
to detect de-exciting γ rays emitted by the inelasticallyscattered nuclei. Figure 1 is the Doppler-corrected γray spectra for 27 F nuclei. The plot shows three peaks
at around 450, 750 and 1200 keV. Though the statistics are low, it is straightforward that the energy sumof the ﬁrst two peaks gives the energy of the third one.
These results suggest that at least two excited states
are bound in 27 F.

Fig. 1. Doppler-corrected spectra of γ-rays emerging from
27
F(p,p )27 F reaction.

References
1) H. Sakurai et al.: Phys Lett. B 448, 1147 (1990).
2) Y. Utsuno et al.: Phys. Rev. C 64, 011301 (2001).
3) T. Otsuka et al.: Eur. Phys. J. A 15, 151 (2002).
4) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).
5) H. Sakurai et al.: Phys. Lett. B 448, 180 (1999).
6) H. Akiyoshi et al.: RIKEN Accel. Prog. Rep. 32, 167(1999).
7) H. Hasegawa et al.: RIKEN Accel. Prog. Rep. 35, 169(2002).

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RIKEN Accel. Prog. Rep. 37 (2004)

Gamma-ray spectroscopy of 23 F with proton transfer reaction
S. Michimasa,∗1 S. Shimoura,∗1 H. Iwasaki,∗2 M. Tamaki,∗1 N. Aoi, H. Baba,∗3 N. Iwasa,∗4 S. Kanno,∗3
S. Kubono,∗1 K. Kurita,∗3 M. Kurokawa, T. Minemura, T. Motobayashi, M. Notani,∗1
H. J. Ong,∗2 S. Ota,∗5 A. Saito,∗3 H. Sakurai,∗2 S. Takeuchi,
E. Takeshita,∗3 Y. Yanagisawa, and A. Yoshida
NUCLEAR REACTION: 4 He(22 O, 23 F∗ ), Transfer reaction, In-beam γ-ray spectroscopy
Neutron-rich ﬂuorine isotopes are interesting in theirfeatures. A recent discovery revealed that the stabilityof neutron-rich isotopes remarkably changes between
oxygen and ﬂuorine isotopes.1) The ﬂuorine isotopes
are extended up to 31 F with N = 22 beyond the magic
number of N = 20 while the heaviest oxygen isotope
is 24 O with N = 16. This feature may indicate thata strong attraction works between a valence proton on
the d5/2 shell and valence neutrons in ﬂuorine isotopes.
To ensure this feature, it is essential to know the proton shell structures in ﬂuorine isotopes as a functionof neutron number. One-proton transfer reactions areeﬀective tools for investigating proton shell structure.
We have, hence, measured de-excitation γ-rays fromthe excited states in 23 F via the proton transfer reaction, 4 He(22 O, 23 F).
The experiment was performed at the RIPS beamline in RIKEN. The 40 Ar ions were accelerated up
to 63 MeV/nucleon by the linear accelerator scheme of
RFQ-RILAC-CSM-RRC. The maximum intensity ofthe primary beam was achieved up to 800 pnA. The
primary target was 9 Be with a thickness of 1 mm. The
unstable 22 O beam was produced by their projectile
fragmentation reaction, and bombarded a liquid helium target2) of 100 mg/cm2 with Havor foil windows.
The mean energy of 22 O was 35 MeV/nucleon, and its
intensity was 2 × 103 particles/s on average. The 22 O
ions and contaminating beam particles were identiﬁed
event-by-event using ∆E and TOF. Reaction products were identiﬁed from TOF, ∆E, and E, whichwere measured by a telescope consisting of 9 SSDs
and 36 NaI(Tl) scintillators.3) The masses of the products were determined with the resolution of 0.3 mass
unit. Furthermore, de-excited γ-rays from the reaction products were detected by 150 NaI(Tl) scintillators4) surrounding the secondary target. The γ-ray
detector system has the energy resolution of 8% (σ)
for 3.2-MeV γ-rays from 22 O traveling with β ∼ 0.27,
and the eﬃciency of 14.5% for 1.33-MeV γ-rays froma 60 Co standard source.
A Doppler-corrected γ-ray energy spectrum obtained via the 4 He(22 O, 23 Fγ) reaction is shown in
∗1
∗2
∗3
∗4
∗5

Fig. 1. The γ-ray energies were reconstructed by summing up the energies of multiple γ-rays detected inneighboring NaI(Tl) crystals. In the present experiment, we observed ﬁve de-excited γ-rays at 0.9, 2.3,
2.9, 3.4, and 4.1 MeV. The 3.4-MeV γ-ray was observed for the ﬁrst time in the present experiment. The
2.3-MeV, 2.9-MeV, and 4.1-MeV γ-rays were expected
to be de-excitation ones to the ground state from theexcited states reported in Ref. 5. It was also conﬁrmedthat the γ-rays at 0.9 and 2.9 MeV were members of
the cascade decay reported in Ref. 6.
In further analysis, we will deduce the orbital angular momenta of these excited states from the angular
distributions for the proton transfer reaction.

Fig. 1. De-excitation γ-ray energy spectrum of 23 F obtained from the 4 He(22 O, 23 Fγ) reaction.

References
1) H. Sakurai et al.: Phys. Lett. B 448, 180 (1999).
2) H. Akiyoshi et al.: RIKEN Accel. Prog. Rep. 34, 193(2001).
3) M. Tamaki et al.: CNS-REP-59, 76 (2003).
4) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 36, 148(2003).
5) N. A. Orr et al.: Nucl Phys. A 491, 457 (1989).
6) D. Guillemaud-Mueller: Eur. Phys. J. A 13, 63 (2002).

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

57

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RIKEN Accel. Prog. Rep. 37 (2004)

Gamma-ray spectroscopy of 22 O with α inelastic scattering
M. Tamaki,∗1 S. Shimoura,∗1 H. Iwasaki,∗2 S. Michimasa,∗1 N. Aoi, H. Baba,∗3 N. Iwasa,∗4 S. Kanno,∗3
S. Kubono,∗1 K. Kurita,∗3 M. Kurokawa, T. Minemura, T. Motobayashi, M. Notani,∗1
H. J. Ong,∗2 S. Ota,∗5 A. Saito,∗3 H. Sakurai,∗2 S. Takeuchi, E. Takeshita,∗3
Y. Yanagisawa, and A. Yoshida
NUCLEAR REACTION: He(22 O, 22 Oγ), α Inelastic Scattering, In-beam γ-ray spectroscopy
The spectroscopy of neutron-rich oxygen isotopes
has attracted much attention, since information on nuclear structure such as single-particle levels and collectivities can be studied as a function of neutron numbers in proton-magic nuclei. In the few experimental studies on the 22 O nucleus so far, where measurements of de-excitation γ rays from inelastic scatteringof a Au target1) and a fragmentation reaction2) havebeen reported. In order to obtain more spectroscopic
information on the 22 O, we have performed an experiment on an α inelastic scattering in inverse kinematics
by measuring de-excitation γ rays coincident with the22
O ejectile. Here the α inelastic scattering on a spin-0
nucleus can populate several excited states having natural parities3) which can be determined by the analysis of angular distributions of diﬀerential cross sections
depending on the transferred angular momenta.
The experiment was performed at the RIKEN Accelerator Research Facility. The 22 O beam was producedby fragmentation of a 63 MeV/nucleon 40 Ar primarybeam incident on a beryllium target of 180 mg/cm2
thickness. Fragments were separated by the RIPS separator. The 22 O beam was identiﬁed event-by-event
using the TOF-∆E method. the TOF was the ﬂight
time between two plastic scintillators at the second(F2) and third (F3) focal planes of the RIPS. The∆E was measured with a 325-µm Si detector installedat F2. The average intensity of the 22 O beam was
2 × 103 cps, and its purity was 37%. The 22 O beam
bombarded a liquid helium target of 100 mg/cm2 thickness sealed using 6 µm havar foils of 30 mm diameter.4)
The energy of the 22 O beam was 35 MeV/nucleon at
the center of the secondary target. The scattering angles of outgoing particles were determined by three
PPACs. Two of them were installed upstream and theother was installed downstream of the secondary. The
particle identiﬁcation of outgoing products from thesecondary target was performed using TOF, ∆E andE information measured using a telescope consisting ofa Si array and a NaI(Tl) array.5) The excited states in22
O were identiﬁed by de-excitation γ rays which weredetected by the DALI(II) system6) which consists of
150 NaI(Tl) crystals surrounding the secondary target.
∗1
∗2
∗3
∗4
∗5

58

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

Figure 1 shows the doppler-shift-corrected energy
spectra of γ rays from the 4 He(22 O, 22 Oγ) reaction.
In Fig. 1 (a), two peaks are clearly observed at 3.2 and
1.4 MeV. The 3.2-MeV γ ray was corresponds to theγ ray which was reported in Refs. 1 and 2. In order
to identify a cascade transition, we examined a γ ray
spectrum coincident with the 3.2-MeV γ-ray which isthe strongest transition as shown in Fig. 1 (b). It isclear that the 1.4-MeV γ ray corresponds to a memberof a cascade transition through the ﬁrst excited state
as speculated in Ref. 2. These results indicate that
there are two excited state at 3.2 and 4.6 MeV. In order to assign spins to these states the analysis of theangular distributions for the inelastic scattering is now
in progress.

Fig. 1. (a) Doppler-shift-corrected energy spectrum ofγ rays from the 4 He(22 O, 22 Oγ) reaction. (b) The γ-ray
energy spectrum coincident with 3.2-MeV γ ray.

References
1) P. G. Thirolf et al.: Phys. Lett. B 485, 16 (2000).
2) F. Azaiez et al.: Nucl. Phys. A 704, 37 (2002).
3) H. Baba et al.: CNS-REP-59, 17 (2003).
4) H. Akiyoshi et al.: RIKEN Accel. Prog. Rep. 34, 193(2001).
5) M. Tamaki et al.: CNS-REP-59, 76 (2003).
6) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 36, 148(2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Invariant-mass spectroscopy of 16 B
T. Sugimoto,∗1 T. Nakamura,∗1 N. Fukuda, M. Miura,∗1 Y. Kondo,∗1 N. Aoi, H. Baba,∗2 D. Bazin,∗3
T. Gomi,∗2 H. Hasegawa,∗2 N. Imai, T. Kobayashi,∗4 T. Kubo, T. Motobayashi, A. Saito,∗2
H. Sakurai,∗5 S. Shimoura,∗6 A. M. Vinodkumar,∗1 K. Watanabe,∗4 Y. X. Watanabe,∗7
T. Yakushiji,∗4 Y. Yanagisawa, K. Yoneda,∗3 and M. Ishihara

NUCLEAR REACTIONS: C(17 B,15 BnX), Nuclear breakup
The nuclear structure of 17 B, which is a Borromean
nucleus, has been studied by investigating the unboundsubsystem1,2) of 16 B. In this report, we show the
preliminary result of the relative energy spectrum of
the 15 B + n system studied using nuclear breakup reactions. In the spectrum, we observed the possible
ground state of the 16 B nucleus.
The experiment was performed at the radioactive
beam facility RIPS. The secondary 17 B beam wasproduced by the fragmentation of 22 Ne at 110 MeV/
nucleon. The secondary beam was identiﬁed event by
event using the time-of-ﬂight (TOF)-∆E method. The
secondary carbon target (377 mg/cm2 ) was bombarded
by 17 B with a central energy of 75 MeV/nucleon. 17 B
were broken up into charged particles and neutrons,
and these fragments were measured in coincidence.3,4)
The outgoing charged fragments were measured using a magnetic spectrometer, which consists of a dipole
magnet, two drift chambers, and a hodoscope. The
downstream drift chamber contains ﬁve and four
planes for the measurement of horizontal (x) and vertical (y) positions, respectively. The average position resolutions were approximately 350 and 310 µm(FWHM), respectively. The time resolution of the hodoscope was 420 ps (FWHM). The mass number andatomic number of the fragment were identiﬁed by using the TOF information between the target and hodoscope, the energy loss signal in the hodoscope, andthe tracking information of the drift chamber. The
momentum vectors of the outgoing fragments were reconstructed from the reaction point upon the target,
the traced rays obtained from the drift chamber, andthe TOF information. The outgoing neutrons weredetected with an array of 54 plastic scintillator rods.
These rods were arranged into two walls in order toseparate events from crosstalk. The momentum vectors of neutrons were reconstructed from TOF and hit
positions of neutrons.
Figure 1 shows the preliminary result of the relative
energy spectrum of the 15 B + n system. The estimated
∗1
∗2
∗3
∗4
∗5
∗6
∗7

Fig. 1. Preliminary result of the relative energy spectrumof 15 B+n system. A narrow peak can be seen in the lowenergy part of this spectrum. This peak is a candidate
for the ground state of 16 B. The estimated relative√
energy resolution is ∆Erel = 0.32 Erel MeV.

√
relative-energy resolution is ∆Erel = 0.32 Erel MeV.
In the spectrum, a narrow peak at 70 keV is observed.
Assuming that the narrow peak is a 1d resonance andthe remaining part is a continuum 2s component, we
ﬁt the experimental result using the theoretical model
based on Ref. 5. The energy of the peak is consistent
with the result reported in Ref. 6. This peak can bea candidate of the ground state of 16 B.
References
1) M. Zinser et al.: Nucl. Phys. A 619, 151 (1997).
2) P. Santi et al.: Phys. Rev. C 67, 24606 (2003).
3) T. Nakamura et al.: RIKEN Accel. Prog. Rep. 35, 57(2002).
4) T. Sugimoto et al.: RIKEN Accel. Prog. Rep. 36, 67(2003).
5) G. F. Bertsch et al.: Phys. Rev. C 57, 1366 (1998).
6) R. Kalpakchieva et al.: Eur. Phys. J. A 7, 451 (2000).

Tokyo Institute of Technology
Rikkyo University
National Superconducting Cyclotron Laboratory, Michigan
State University, USA
Tohoku University
University of Tokyo
Center for Nuclear Study, University of Tokyo
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)59

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RIKEN Accel. Prog. Rep. 37 (2004)

Inelastic scattering of 15 B and 17 B
Y. Kondo,∗1 T. Nakamura,∗1 N. Fukuda, T. Sugimoto,∗1 M. Miura,∗1 N. Aoi, N. Imai, T. Kubo, T. Kobayashi,∗3
T. Gomi,∗4 A. Saito,∗4 H. Sakurai,∗2 S. Shimoura,∗2 D. Bazin,∗5 H. Hasegawa,∗4 H. Baba,∗4 T. Motobayashi,
T. Yakushiji,∗3 Y. Yanagisawa, K. Yoneda, K. Watanabe,∗3 Y. X. Watanabe,∗6 and M. Ishihara

NUCLEAR REACTIONS: C(15 B, 15 B∗ ), C(17 B, 17 B∗ ), in-beam gamma-ray spectroscopy
Bound excited states of 15 B and 17 B were studied by the inelastic scattering with a carbon target. We used a method of in-beam gamma-ray spectroscopy. Neutron-rich B isotopes are considered tohave a unique feature such as halo and/or cluster
structure. In a previous theoretical study, it was predicted that, with increase in a neutron number, B isotopes have clustering structure.1) The two-neutron
halo structure of 17 B was observed recently.2)
In-beam gamma-ray spectroscopy with a radioactive
ion beam is a powerful tool to study a broad range ofneutron-rich nuclei even extending to the neutron drip
line. In this method, the gamma ray from an excitedprojectile is measured with a scattered ejectile in coincidence. By correcting the Doppler shift due to a velocity of the projectile, one can determine rather precisely an excitation energy and a transition probabilityof the bound excited states. In addition, we also measured a scattering angle of a particle. This information
is useful to determine the transition multipolarity.
The experiment was performed at the radioactiveisotope beam separator, RIPS. 15 B and 17 B beams
delivered from the RIPS were bombarded on a carbon
target with a thickness of 377 mg/cm2 . The carbon
target was employed populating the excited states of15
B and 17 B. The energies of the 15 B and 17 B beam
were 72 MeV/u at the middle of the target. The experimental setup is described in Ref. 3.
The first excited states in 15 B and 17 B were observed
to be 1.35(1) MeV and 1.07(1) MeV, respectively, forthe first time. In coincidence with these gamma transitions, angular distributions of the inelastically scattered 15 B and 17 B were extracted. Figure 1 shows
angular distributions of the inelastically scattered 15 B
and 17 B in c.m. frame. We compared the data withthe calculation by using a coupled channel calculation

∗1
∗2
∗3
∗4
∗5
∗6

60

Tokyo Institute of Technology
University of Tokyo
Tohoku University
Rikkyo University
National Superconducting Cyclotron Laboratory, Michigan
State University, USA
High Energy Accelerator Research Organization (KEK)

Fig. 1. Angular distributions of the inelastically scattered
15
B and 17 B. Lines show calculated distributions using
the ECIS code with the assumption of a pure E2 transition.

code ECIS97. In this calculation, we used the optical potential parameters determined for the 16 O + 12 C
reaction.4) The calculated distribution well matchedwith the experimental data when we assumed a pureE2 transition. Further analysis is now in progress.
References
1) Y. Kanada-En’yo and H. Horiuchi: Phys. Rev. C 52,
647 (1995).
2) T. Suzuki et al.: Phys. Rev. Lett. 89, 12501 (2002).
3) Y. Kondo et al.: RIKEN Accel. Prog. Rep. 36, 65(2003).
4) M.-E. Brandan: Phys. Rev. Lett. 60, 784 (1988).

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RIKEN Accel. Prog. Rep. 37 (2004)

Proton inelastic scattering of 19 C
Z. Elekes,∗1 Zs. Dombrádi,∗2 R. Kanungo, H. Baba,∗3 Zs. Fülöp,∗2 J. Gibelin,∗4 Á. Horváth,∗5 E. Ideguchi,∗6
Y. Ichikawa,∗6 N. Iwasa,∗7 H. Iwasaki,∗6 S. Kanno,∗3 S. Kawai,∗3 Y. Kondo,∗3 T. Motobayashi, M. Notani,∗6
T. Ohnishi,∗6 A. Ozawa, H. Sakurai,∗6 S. Shimoura,∗6 T. Suzuki,∗3 E. Takeshita,∗3 S. Takeuchi, I. Tanihata,
Y. Togano,∗3 C. Wu,∗8 Y. Yamaguchi,∗3 Y. Yanagisawa, A. Yoshida, and K. Yoshida
NUCLEAR STRUCTURE, Unstable nuclei, proton inelastic scattering, 19 C, 17 B, excitedstates
The isotope 19 C is a good candidate for a one–neutron halo nucleus since it has a low binding energy and a possible spin 1/2 ground state. Several
experiments aimed at exploring the structure of 19 C
by Coulomb dissociation,1) parallel momentum distribution,2) reaction cross section3) e.g. in Ref. 1–3, forexample, have been carried out. The results suggest
the expected halo structure; however, an open question
remains regarding the conﬁguration of the unpaired
neutron. Experimental information on excited levels
might help to further understand the nuclear structureof 19 C since these levels are rarely studied.
We have studied the 19 C(p, p ) reaction, which is expected to excite possible low-lying states even if they
are diﬃcult to reach through electromagnetic interaction.
The experiment was carried out at the RIKEN radioactive isotope separator RIPS.4) A 22 Ne primarybeam of 100 pnA intensity and 110 A MeV energy hit
a 9 Be production target of 0.8 cm thickness. After
momentum and mass analysis, the secondary cocktail
beam including 19 C at 20% and 17 B at 25% was transmitted to a liquid hydrogen target of 190 mg/cm2 average thickness.5) The mean energiues of 19 C and 17 B
isotopes were calculated to be 49.4 and 43.8 A MeV,
respectively, from the incident energies and the energy loss in the target. The total beam intensity wasaround 800 cps and the momentum acceptance was set
to 6%. The incident nuclei could be fully separated
from each other by energy loss and time-of-ﬂight measurements. The beam focus was monitored by two
PPACs placed upstream of the secondary target. The
scattered isotopes were identiﬁed using a silicon telescope consisting of three layers with thicknesses of 0.5,
2.0 and 2.0 mm. The ∆E-E method was used for the
separation of the diﬀerent carbon and boron isotopes.
19
C and 17 B were well separated from other products
emerging in neutron removal reactions in the liquid
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

On leave from Insitute of Nuclear Research (ATOMKI),
Hungary
Insitute of Nuclear Research (ATOMKI), Hungary
Rikkyo University
Institut de Physique Nucléaire, FranceEötvös Lóránd University, Hungary
University of Tokyo
Tohoku University
Peking University, Chinahydrogen target. The 158 NaI(Tl) scintillator detectors of the DALI2 array6) surrounded the target anddetected the de-exciting γ rays emitted by the inelastically scattered nuclei. The threshold was set to 30 keVtaking into account the Doppler eﬀect. Figure 1 is the
Doppler-corrected γ ray spectra for 19 C and 17 B nuclei. Some peaks, including the ones reported earlier
for 19 C7) and 17 B,8) were observed. Further analysis
and assignment of these peaks is now in progress.

Fig. 1. Doppler-corrected spectra of γ rays emerging from19
C(p, p )19 C (upper panel) and 17 B(p, p )17 B (lower
panel) reactions.

References
1) T. Nakamura et al.: Phys. Rev. Lett. 83, 1112 (1999).
2) R. Kanungo et al.: Nucl. Phys. A 701, 378c (2002).
3) A. Ozawa et al.: RIKEN Accel. Prog. Rep. 32, 83(1998).
4) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).
5) H. Akiyoshi et al.: RIKEN Accel. Prog. Rep. 32, 167(1998).
6) H. Hasegawa et al.: RIKEN Accel. Prog. Rep. 35, 169(2001).
7) M. Stanoiu: Thesis, Univ. Caen, code:tel-00002775(2003).
8) Y. Kondo et al.: RIKEN Accel. Prog. Rep. 36, 65(2003).

61

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

First excited state of 30 Ne studied by proton inelastic scattering inreversed kinematics†
Y. Yanagisawa, M. Notani,∗1 H. Sakurai,∗2 M. Kunibu,∗3 H. Akiyoshi, N. Aoi, H. Baba,∗3 K. Demichi,∗3
N. Fukuda, H. Hasegawa,∗3 Y. Higurashi, M. Ishihara, N. Iwasa,∗4 H. Iwasaki,∗2 T. Gomi,∗3 S. Kanno,∗3
M. Kurokawa, Y. U. Matsuyama,∗3 S. Michimasa,∗1 T. Minemura, Y. Mizoi, T. Nakamura,∗5
A. Saito,∗3 M. Serata,∗3 S. Shimoura,∗1 T. Sugimoto,∗5 E. Takeshita,∗3 S. Takeuchi,
K. Ue,∗2 K. Yamada,∗3 K. Yoneda,∗6 and T. Motobayashi
Nuclear structure, 30 Ne, Proton inelastic scattering, Unstable nuclei
An interesting aspect of nuclei around N = 20 is
the transition from spherical to deformed shapes ina region centered at Z ∼ 11 and N ∼ 21, which isreferred to as the ‘island of inversion’.1) We report on
the ﬁrst measurement of the ﬁrst excited state of 30 Ne,
which is expected to be the last even-even N = 20
nucleus.
In-beam γ spectroscopy using fast radioactive beams
has been carried out by some methods in recent years.
We have employed it with proton inelastic scattering inreversed kinematics using a liquid-hydrogen target bydetecting de-excitation γ rays in coincidence with scattered particles. This method is advantageous becauseof the high experimental eﬃciency in determining thelocations of low-lying excited states. Compared to thehigh-Z targets used in Coulomb excitation, the number of target atoms per g/cm2 in liquid hydrogen issubstantially larger, typically by two orders of magnitude.
The experiment was performed using the RIPS.2) A
primary 40 Ar beam of 94 MeV/nucleon with a typical intensity of 60 pnA bombarded a 181 Ta target witha thickness of 641 mg/cm2 . To reduce the amountof beam impurities, an aluminum wedged degrader
having a mean thickness of 321 mg/cm2 was installedon the momentum dispersive focal plane (F1). Secondary ions were collected using the optimized magnetic rigidity setting for 30 Ne and with the full momentum acceptance of the RIPS (±3%). The intensityof the 30 Ne beam with an average incident energy of
56 MeV/nucleon was obtained to be 0.2 cps with thecontamination of 29 Ne, 31 Na and 32 Na beams. A liquid hydrogen target3) was placed at the ﬁnal focusof the RIPS to excite the projectiles. The thicknessof the hydrogen target cell was 24 mm and the entrance and exit windows were made of 6.6-µm-thickHavar foil. The resultant areal density of hydrogen was
186 mg/cm2 on average. Scattered particles were detected and identiﬁed by a PPAC and a silicon-detector
†
∗1
∗2
∗3
∗4
∗5
∗6

62

Condensed from the article in Phys. Lett. B 556, 84 (2003)
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Department of Physics, Rikkyo University
Department of Physics, Tohoku University
Department of Physics, Tokyo Institute of Technology
Department of Physics, Michigan State University, USA

telescope located about 50 cm downstream of the target. In the DALI setup, sixty-eight NaI(Tl) scintillators were placed around the target to detect the deexcitation γ rays emitted from the excited nuclei.
The energy of the de-excitation γ rays from 30 Newith the Doppler correction was obtained to be791(26) keV, by measuring the 30 Ne secondary beams
in coincidence with scattered particles. Considering
this systematic trend, the 791 keV γ ray is consistent
with the 2+ → 0+ de-excitation in 30 Ne, leading to theﬁrst 2+ energy E(2+ ) of 791 keV.
The quadrupole deformation parameter of the791 keV state was extracted by a coupled channel calculation using the ECIS79 code in the framework of
the standard symmetric rotational model. By taking
the γ-ray detection eﬃciency into account, the corresponding experimental cross section of the 791 keVtransition was calculated to be 30 ± 18 mb. By comparing the calculated and experimental cross sections,= 0.58+0.16
the deformation parameter β p,p2−0.22 was obtained. Under the assumption that electromagnetic= β emdeformation is the same as nuclear one (β p,p2 ),2
the reduced E2 transition probability B(E2) was estimated to be 460 ± 270 e2 fm4 .
In summary, the ﬁrst excited state of the very
neutron-rich nucleus 30 Ne was measured for the ﬁrst
time. In-beam γ spectroscopy was applied using proton inelastic scattering and a liquid hydrogen target.
The observed energy of 791(26) keV for 30 Ne is thelowest among the 2+ energies of even-even N = 20
isotones, suggesting a large deformation of 30 Ne, andthat the 30 Ne nucleus thus belongs to the ‘island of
inversion.’ The B(E2) value estimated from the (p, p )cross section also supports this conclusion.
References
1) E. K. Warburton et al.: Phys. Rev. C 41, 1147 (1990).
2) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).
3) H. Akiyoshi et al.: RIKEN Accel. Prog. Rep. 32, 167(1999).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Search for low lying dipole strength in the neutron rich nucleus 26 Ne
J. Gibelin,∗1,∗2 K. Yoshida, D. Beaumel,∗1 N. Fukuda, N. Aoi, H. Baba,∗2 Y. Blumenfeld,∗1 Z. Elekes,
T. Gomi,∗2 K. Ishikawa,∗3 Y. Kondo,∗3 T. Kubo, V. Lima,∗1 T. Motobayashi, T. Nakamura,∗3 A. Saito,∗2
Y. Satou,∗3 E. Takeshita,∗2 S. Takeuchi, T. Teranishi,∗4 Y. Togano,∗2 A. M. Vinodkumar,∗3 and Y. Yanagisawa
Nuclear structure, Coulomb excitation, 26 Ne
We measured Coulomb excitation in 26 Ne to investigate low lying E1 strength in 26 Ne, for which somepredictions exist,1) using the invariant mass method.
In this experiment, 26 Ne was selected by the RIKEN
Projectile fragment Separator (RIPS) after a 2-mmthick Be production target was bombarded with a
95 MeV/n 40 Ar beam. We thus required a secondary
26
Ne beam with an energy of 58 MeV/n, an averagerate of 10 kcps and a purity of 80%. The main contaminant was 29 Mg. In order to obtain information on
the contributions of E1 vs. E2 and Coulomb vs. nuclear excitations, measurements have been performed
using Pb and Al targets. The Pb target being morecharged is expected to induce more Coulomb excitation than Al, which is used to subtract the nuclear
reaction part. Hence, we used secondary targets of
230 mg/cm2 Pb and 130 mg/cm2 Al.
Secondary beam momentum vectors were obtainedby tracking with two parallel-plate avalanche counters
placed before the target and using time-of-ﬂight (TOF)
information between the production target (RF signal)
and a 5 mm plastic scintillator located downstream of
the RIPS F2 focal point. The detection setup at thelast focal point is represented on Fig. 1. The momenta
and energies of outgoing charged fragments were measured using a telescope placed at 1.2 m upstream of
the target and consisted of two layers (X and Y) of 8
silicon strip detectors (SSD) that can determine a position with a precision of 5 mm and an energy loss (dE)of 2% (FWHM). The last layer used 3-mm-thick Si(Li)(8 pieces) from the charged-particle detector, MUST,2)
which provided a 3% (FWHM) precision on the energy(E).
In-beam γ rays were detected using a 4π-γ-detector,
DALI,3) which consisted of 152 NaI detectors placedaround the target. For 2 MeV γ rays, its eﬃciency is
calculated to be approximately 10% with a precisionof 7% (FWHM). The hodosope for neutron detection
was a cross-shape array of 4 layers of 29 plastic rods
each, placed 3.5 m downstream of the target. Eachlayer was composed of 13 [2.1 m×6 cm×6 cm] and 2
times 8 [1.1 m× 6 cm× 6 cm] rods. Its total intrinsic
eﬃciency was calculated to be ∼25%. Finally, 29 plastic rods, sensitive to charged particles, covered the active hodoscope front face in order to be used as vetoes
∗1
∗2
∗3
∗4

Institut de Physique Nuclaire, France
Department of Physics, Rikkyo University
Department of Physics, Tokyo Institute of Technology
Center for Nuclear Study, University of Tokyo

Fig. 1. Overview of the whole setup.

and active beam stoppers. The position is expected to
be determined with a precision of 6 cm (FWHM) andthe energy, from TOF information, with 4% (FWHM).
26
Ne was identiﬁed using TOF, charged fragments with
dE-E method and neutron by suppressing simultaneous events in veto.
The data obtained are still under analysis but therate of triple coincidence (26 Ne beam ⊗ 25 Ne in silicons ⊗ neutron) measured during the experiment isapproximately 1 event per minute. This is compatible
with the results of simulations, assuming an excitationof 8 MeV and 10% of the energy weighted sum rule
for ECIS cross-section (∼120 mb) calculation. Shownin Fig. 2 are preliminary results for the distributionof relative energy between 25 Ne and neutron. Basedon the neutron emission threshold for 26 Ne being at
5.6 MeV, the energy of interest here should be approximately 2.5 MeV.

Fig. 2. Preliminary results for relative energy distribution
between 25 Ne and neutron: (1) using runs with Pb target and by weighted subtraction from no-target runs;(2) detection eﬃciency weighted summation from Pbtarget runs, in coincidence with γ emitted from 25 Ne∗ .

References
1) Z. Ma: Private communication.
2) Y. Blumenfeld et al.: Nucl. Instrum. Methods Phys.
Res. A 421, 471 (1999).
3) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 36, 148(2002).

63

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Direct measurement of the astrophysical reaction 14 O(α, p)17 F
M. Notani,∗1 S. Kubono,∗1 T. Teranishi,∗1 Y. Yanagisawa, S. Michimasa,∗1 K. Ue,∗1 T. Minemura,
Zs. Fülöp,∗2 J. J. He,∗1 H. Iwasaki,∗3 H. Baba,∗4 M. Tamaki,∗1 S. Shimoura,∗1 N. Hokoiwa,∗5
Y. Wakabayashi,∗5 T. Sasaki,∗5 T. Fukuchi,∗5 A. Odahara,∗6 Y. Gono,∗5 E. K. Lee,∗7
K. I. Hahn,∗7 J. Y. Moon,∗8 C. C. Yun,∗8 J. H. Lee,∗8 C. S. Lee,∗8 and S. Kato∗9
NUCLEAR REACTIONS 14 O(α, p)17 F, Unstable nuclei, Nuclear astrophysics
Explosive hydrogen burning of light nuclei occurs ina hot and dense stellar environment such as those of novae and X-ray bursts. As a starting point of the rapid
proton-capture (rp-) process, nuclear reactions in the
breakout process from the hot-CNO cycle are highly interesting in the ﬁeld of nuclear astrophysics.1) At hightemperatures, the 14 O(α, p)17 F (p, γ)18 Ne (α, p)21 Nareaction sequence can provide a path way into therp-process. Therefore, the rate of the 14 O(α, p)17 F
reaction is important for understanding the breakout
process. This reaction has been studied via only indirect methods and time-reverse reaction so far. A direct
measurement of the 14 O(α, p)17 F reaction is diﬃcult
since it requires an intense low-energy 14 O beam anda helium gas target.
The experiment was performed using the CNS radioactive ion beam separator (CRIB),2) which was recently installed by CNS, in the RIKEN accelerator research facility. A primary beam of 14 N was accelerated
up to an energy of 8.4 A MeV in the RIKEN AVF cyclotron with K = 70. The maximum intensity of thebeam was 300 pnA. The primary beam bombarded
a CH4 gas target with a thickness of 1.3 mg/cm2 .
The target gas was conﬁned in a small chamber withentrance and exit windows made of 2.2-µm Havar
foils. A secondary beam of 14 O was produced by
the 1 H(14 N, 14 O)n reaction. An energy degrader of
10-µm-thick mylar foil was installed at the momentum dispersive focal plane (F1) to remove backgroundlight ions from the secondary beam. A horizontal slit
was set to select the 14 O particles at a mean energyof 6.40 A MeV after the degrader with the momentum
acceptance of 1%.
At the achromatic focal plane (F2), a series of detectors and a secondary target were installed in a vacuum chamber. The setup consisted of two parallelplate avalanche counters (PPACs), a helium gas target
with a thickness of 3.57 mg/cm2 , and a silicon-detector
stack with thicknesses of 0.02, 0.07, 1.5 and 1.5 mm.
Particle identiﬁcation was performed for each event
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

64

Center for Nuclear Study, University of TokyoATOMKI, Hungary
University of Tokyo
Rikkyo University
Kyushu University
Nishinippon Institute of Technology
Ewha Womans University, Korea
Chun-Ang University, Korea
Yamagata University

on the basis of time of ﬂight (TOF) between the two
PPACs. The purity of the 14 O beam was 85% at F2.
A cold helium gas target was bombarded with the
14
O beam at an incident energy of 43 MeV. The helium gas was conﬁned in a 50-mm-long cell with two
windows of 2.2-µm-thick Havar foils. It was kept at
a pressure of 0.6 atm and was cooled to 30 K. The
target was chosen to be as thin as possible, but sufﬁciently thick to stop the 14 O nuclei in it. The novel
helium gas target was designed oﬀering ten times larger
density than at room temperature. This design resultsin exceedingly compactness and thus makes it possible
to eﬀectively apply the thick-target method.3) The reaction products emitted from the helium target wereidentiﬁed by the ∆E-E method, using the telescope offour silicon detectors located at 0◦ .
From the proton spectrum, the reaction cross sections were obtained in the energy range of 0.8–3.8 MeV
in the center-of-mass system of 14 O + α. Eight resonances are clearly identiﬁed in the data which correspond to previously observed states at 6.15, 6.29,
7.05, 7.12, 7.35, 7.62, 7.95 and 8.30 MeV in 18 Ne.4)
In addition, we newly observed a peak related to the14O(α, p)17 F∗ reaction leading to the 1/2+ ﬁrst-excitedstate in 17 F, which undergoes a resonance at aroundEx (18 Ne) = 7.1 MeV, as shown in Fig. 1. Further analysis is in progress.

Fig. 1. Level scheme in 18 Ne.

References
1) R. K. Wallace and S. E. Woosley: Astrophys. J. Suppl.
Ser. 45, 389 (1981).
2) Y. Yanagisawa et al.: RIKEN Accel. Prog. Rep. 34, 183(2001).
3) K. P. Artemov et al.: Sov. J. Nucl. Phys. 52, 408 (1990).
4) K. I. Hahn et al.: Phys. Rev. C 54, 1999 (1996).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Study of astrophysically important resonance states in
26
Si and 27 P using radioactive ion beams
J. Y. Moon,∗1 C.-S. Lee,∗1 J.-H. Lee,∗1 C. C. Yun,∗1 J. C. Kim,∗2 M. Youn,∗2 S. Kubono,∗3 T. Teranishi,∗3
J. J. He,∗3 M. Notani,∗3 S. Nishimura, M. Kurata-Nishimura, S. Kato,∗4
V. Guimarães,∗5 and R. F. Lihitenthaler∗5
Nucleoastrophysics, radioactive ion beam, 26 Si, 27 P
1.809 MeV gamma rays, observed by COMPTELof CGRO, are known to be produced when 26 Al(g.s)β-decays to the ﬁrst exited state in 26 Mg followed byde-exciting to its ground state. Their sources are notclearly identiﬁed yet. In thermonuclear runaway under
explosive hydrogen burning, the 25 Al(p, γ)26 Si reaction
hinders production of 26 Al(g.s.) and thus its nuclear
structural information, such as excitation energy andspin parity is needed to calculate the reaction rate andestimate its contribution. In spite of previous experimental eﬀorts, spins of some states including thoseat Ex = 6.470 MeV, 6.880 MeV and 7.019 MeV havenot been clariﬁed yet.1,2) The 26 Si(p, γ)27 P reaction
prevents production of 26m Al. It has been suggested
that high-temperature novae (T ≥ 0.4 GK) are hot sufﬁciently to establish an equilibrium between 26 Al(g.s)
and 26m Al.3) Thus, resonance states in 27 P should bestudied to determine the reaction rate of 26 Si(p, γ)27 P.
Thus far, only one state at 1.199 MeV above the proton
threshold has been reported.4)
The radioactive beams used in this experiment wereobtained by the CNS radioactive ion beam separator (CRIB). A 24 Mg8+ primary beam, accelerated by the RIKEN AVF cyclotron (K = 70), bombarded a 3 He gas target at 7.434 A MeV. The thickness of the 3 He gas target was 0.32 mg/cm2 . With3
He(24 Mg, n)26 Si∗ (p)25 Al and 3 He(24 Mg, n)26 Si, twokinds of radioactive beams were produced and used forthe measurement of elastic scattering 1 H(25 Al, p)25 Al
and 1 H(26 Si, p)26 Si. Secondary beams were identiﬁed using TOF between two PPACs on the achromatic focal plane (F2), beam energy and TOF between the production target and the PPACb on theF2 plane. With a slit on the momentum-dispersive focal plane (F1), the purities of secondary beams wereenhanced. Additionally, an energy degrader of 2.6 µm
mylar was used to achieve another particle separation.
The properties of secondary beams are shown in Table 1. The secondary beams bombarded a polyethylene(CH2 ) target of 8.24 mg/cm2 , and fully stopped in thetarget. To detect recoiled protons, two sets of siliconcounter telescopes, which consist of a 75 µm position∗1
∗2
∗3
∗4
∗5

Department of Physics, Chung-Ang University, Korea
Department of Physics, Seoul National University, Korea
Center for Nuclear Study, Graduate School of Science, University of Tokyo
Department of Physics, Yamagata University
Instituto de Fı́sica, Universidade de São Paulo, Brazil

Table 1. The properties of secondary beams on target (averaged).

25

Energy(A MeV)

Intensity (kcps)

Purity (%)

3.44

9.325

4.72

3.95

1.573

0.7

Al

26

Si

sensitive silicon detector (PSD) and 1500 µm surface
barrier silicon detector (SSD), were installed at 0◦ and17◦ . They were also used as ∆E-E telescopes to distinguish them from other recoiled particles, such as
α and heavy ions. In the second set at 17◦ , additional SSD was added to reject the proton with highenergy. In this experiment, we used the thick-target
method to examine a wide excitation energy range in
26
Si and 27 P, where the incident beam can have different energies in the target and interact with the target until its energy is fully absorbed. The secondary
beams had energies of 3.4407 A MeV for the 25 Al beamand 3.9575 A MeV for the 26 Si beam on the target.
Under these conditions, we succeeded in our investigation up to Ex = 8.8243 MeV and Ex = 4.7109 MeV
above the proton threshold. Also, a carbon target wasused to eliminate the contribution of carbon in theCH2 target from the proton spectrum of the CH2 target. The energy calibration of the detector was performed with protons whose energy was determined by
the CRIB magnetic setting. We observed some peaks
below Ex = 8.120 MeV in the 25 Al + p elastic scattering spectrum. Above 8.120 MeV, we could not identify
a resonant structure because of a large contaminant.
For the 26 Si + p elastic scattering spectrum, we also
observed several peaks even with low counting statistics. Now data analysis is in progress. R-matrix analysis will be performed to determine the spins and theexcitation energies of the resonance states.
References
1) D. W. Bardayan et al.: Phys. Rev. C 65, 032801(R)(2002).
2) J. A. Caggiano et al.: Phys. Rev. C 65, 055801 (2002).
3) A. Coc, M.-G. Porquet, and F. Nowacki: Phys. Rev. C
61, 015801 (1999).
4) J. A. Caggiano et al.: Phys. Rev. C 64, 025802 (2001).

65

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RIKEN Accel. Prog. Rep. 37 (2004)

Study of the resonant state in 23 Al relevantto the stellar 22 Mg(p,γ)23 Al reaction
T. Gomi,∗1 T. Motobayashi, Y. Ando,∗1 N. Aoi, H. Baba,∗1 K. Demichi,∗1 Z. Elekes,∗2 N. Fukuda,
Zs. Fülöp,∗2 U. Futakami,∗1 H. Hasegawa,∗1 Y. Higurashi, K. Ieki,∗1 N. Imai, M. Ishihara,
K. Ishikawa,∗3 N. Iwasa,∗4 H. Iwasaki,∗5 S. Kanno,∗1 Y. Kondo,∗3 T. Kubo, S. Kubono,∗6
M. Kunibu,∗1 K. Kurita,∗1 Y. U. Matsuyama,∗1 S. Michimasa,∗6 T. Minemura,
M. Miura,∗3 H. Murakami,∗1 T. Nakamura,∗3 M. Notani,∗6 S. Ota,∗7 A. Saito,∗1
H. Sakurai,∗5 M. Serata,∗1 S. Shimoura,∗6 T. Sugimoto,∗3 E. Takeshita,∗1
S. Takeuchi, Y. Togano,∗1 K. Ue,∗5 K. Yamada,∗1
Y. Yanagisawa, K. Yoneda, and A. Yoshida
NUCLEAR REACTIONS: 208 Pb(23 Al, 22 Mg p)208 Pb, Coulomb dissociation
We have performed an experiment to study thestellar 22 Mg(p, γ)23 Al reaction using the Coulombdissociation method. This reaction is relevant to the
nucleosynthesis of the γ-ray emitter 22 Na in Ne novae. In the energy region of astrophysical interest, theﬁrst excited state of 23 Al is known to be located at
an excitation energy of 0.528 MeV.1) However, there is
no experimental data for the strength of the resonant
capture through this ﬁrst excited state. In the present
work, we aimed at determining the radiation width of
this resonant state.
The experiment was performed at the RIPS beamline. A secondary beam of 23 Al at 50 MeV/nucleon
produced by the projectile fragmentation of 28 Si bombarded a Pb target. The products of the breakup reaction, 22 Mg and a proton, were detected respectively
using silicon counter telescopes and a plastic scintillator hodoscope located 50 cm and 3 m downstreamof the target. In order to deduce the relative energyof the breakup reaction products measured in coincidence, we measured the momentum vectors of theparticles. A stack of sixty-eight NaI(Tl) scintillators(DALI) was placed around the target to measure deexcitation γ-rays from 22 Mg in its excited states, the contribution of which should be subtracted to extract the
Coulomb dissociation cross section of interest. The details of the experimental setup can be found in Ref. 2.
The relative energy spectrum obtained for the208
Pb(23 Al, 22 Mg p)208 Pb reaction is shown in Fig. 1.
We deduced this spectrum after subtracting the contribution of the dissociation process leading to higher
states in 22 Mg using the information from the γ-ray
detector array. Therefore, this spectrum is for the process in which 23 Al disintegrates to the ground state of22
Mg through excited states in 23 Al. In this spectrum,
the ﬁrst excited state of 23 Al corresponds to the peak
∗1
∗2
∗3
∗4
∗5
∗6
∗7

66

Rikkyo University
ATOMKI, Hungary
Tokyo Institute of Technology
Tohoku University
University of Tokyo
Center for Nuclear Study, University of Tokyo
Kyoto University

Fig. 1. Relative energy spectrum obtained for the208
Pb(23 Al, 22 Mg p)208 Pb reaction. The solid curve
represents the result of a fitting with two Gaussianfunctions and a distribution assuming a nonresonant
component. The dashed curves show each component.

around 400 keV. We obtained the cross section of the
Coulomb dissociation through the ﬁrst excited state of23
Al as 4.4 mb. Supposing that the spin and parityof 23 Al are 5/2+ for the ground state and 1/2+ forthe ﬁrst excited state, the cross section corresponds toΓγ = 7.2 × 10−7 eV with an error of 20%.
In order to evaluate the inﬂuence of the22
Mg(p, γ)23 Al reaction on the network calculation forthermonuclear runaway, we consider the competition
with β decay of 22 Mg. According to the temperatureand density condition predicted by nova models,3) the
main reaction ﬂow favors the β decay rather than the
proton capture on 22 Mg.
References
1) J. A. Caggiano et al.: Phys. Rev. C 64, 025802 (2001).
2) T. Gomi et al.: RIKEN Accel. Prog. Rep. 36, 82 (2003).
3) C. Iliadis et al.: Astrophys. J. Suppl. Ser. 142, 105(2002).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Beta decay half-lives of neutron-rich Cr, Mn, Fe, and Co isotopes
S. Nishimura, Y. Nishi, M. A. Famiano,∗1 M. Kurata-Nishimura, R. N. Boyd,∗2 M. E. Howard,∗2
D. Reitzner,∗2 E. E. Smith,∗2 and I. Tanihata[Beta decay, Half-life, r-Process]
The neutron-rich nuclei far from stability are expected to play a key role in the r-process nucleosynthesis. At present, however, the study of these nuclei
in relation to their half-lives, Q values, and neutronemission probabilities is limited by their low production rates.
Our primary experiment was carried out at the
RIKEN Ring Cyclotron (RRC). The neutron-rich V,
Cr, Mn, Fe, Co, and Ni isotopes were produced by thefragmentation of a 63 MeV 86 Kr32+ beam, of mean intensity 1 eµA, onto a 9 Be target of 375 µm thickness.
Figure 1 (a) shows the nuclei identiﬁed using highresolution TOF detectors1) and a 150 µm silicon detector. The beta-ray detection system, which consistsof ion stopper plates attached on the rotating wheel
and high-eﬃciency position-sensitive detectors,2,3) was
installed at the end of the beam line. The event associations between the implanted nuclei and the beta
decays were achieved using the precise position measurement of incident nucleus and the beta-decay points
on the stopper plates. The beta-decay time spectrum
in correlation with the implantation of 65 Mn isotope
is shown in Fig. 1 (b). The cutoﬀ time after 250 ms
is determined by the acceptance of the beta-ray detectors. The half-lives of nuclei were extracted byconsidering the four parameters in the ﬁtting procedure: the half-lives of the mother and daughter nuclei,
the beta detection eﬃciency, and the background rateover the collecting time. The half-lives of daughter nuclei have been obtained from Ref. 4. The backgroundfrom the decay of long-lived nuclei is estimated by theevent-mixing method. Our preliminary results of halflives for the neutron-rich 63,64 Cr, 65,66 Mn, 67,68 Fe, and69,70

Co nuclei are summarized in Table 1. In addition,
the results from other experiments4) and theoreticalpredictions5) are listed for comparison. The discrepancy between the experimental values and the theoretical predictions support the overabundances of 64 Ni
in certain inclusions of meteorites.6)
Our ﬁrst measurement of the half-lives of massive
nuclei above 63–70 amu successfully demonstrated thepossibility of reconstructing the beta-decay spectra ofrare isotopes under high intensities of mixed beam at
the RIBF. Here, the application of the plastic material instead of the silicon detector for the isotope
implantation was aimed to avoid the potential problem of radiation damage on the detector itself together
with the minimization of the accumulated contaminants from the daughters. Further upgrade of thesystem is planned by introducing additional detectors,
CaF2 (Eu), NaI(Tl), and Ge, which enable us to measure the energies of beta and gamma rays simultaneously as well as to reduce the accidental backgrounds
in the detectors.
Table 1. Preliminary results of half-lives of 63,64 Cr,
65,66
Mn, 67,68 Fe, and 69,70 Co nuclei. Also presented
are the results from other experiments4) and theoretical predictions.5)
RI
70
69

Co
Co

68
67
66
65

Fe
Fe

Mn
Mn

64
63

Cr
Cr

R322n
T1/2
(ms)

135 (+11−9 )

197 (+80−29 )

155 (+34−18 )
597 (+209−100 )103 (+44−33 )+1085 (−9 )61 (+60−19 )
161 (+104
−91 )

Exp.
T1/2
(ms)

Theo.
T1/2
(ms)

120

47.5

216

76.6

155

767.3

470

1139

66

23.1

88

28.9

44

153.9

113

96.6

References

Fig. 1. (a) Identification of the nuclei produced in the experiment by their energy loss (dE/dx) and time of flight(TOF). (b) Preliminary beta-decay spectrum of 65 Mn.
∗1∗2National Superconducting Cyclotron Laboratory, USA
Ohio State University, USA

1) S. Nishimura et al.: Nucl. Instrum. Methods Phys. Res.
A 510, 377 (2003).
2) M. A. Famiano, Y. Nishi, S. Nishimura, and I. Tanihata:
Nucl. Instrum. Methods Phys. Res. A 496, 248 (2003).
3) S. Nishimura et al.: Nucl. Phys. A 718, 214c (2003).
4) T. Horiguchi, T. Tachibana, H. Koura, and J. Katakura:
Chart of the Nuclides, Japan Atomic Energy ResearchInstitute (2000).
5) P. Möller, J. R. Nix, and K.-L. Kratz: At. Data andNucl. Data Tables 66, 131 (1997).
6) O. Sorlin et al.: Nucl. Phys. A 719, 193c (2003).

67

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RIKEN Accel. Prog. Rep. 37 (2004)

Investigation of resonant states in 23 Al and 22 Mg using RI beams
J. J. He,∗1 S. Kubono,∗1 T. Teranishi,∗1 M. Notani,∗1 H. Baba,∗2 S. Nishimura, J. Y. Moon,∗3
M. Kurata-Nishimura, S. Michimasa,∗1 H. Iwasaki,∗4 Y. Yanagisawa, N. Hokoiwa,∗5
M. Kibe,∗5 J. H. Lee,∗3 S. Kato,∗6 Y. Gono,∗5 and C. S. Lee∗3[Proton Resonant State, Nuclear Astrophysics]
During the early stage of the rp process, boththe 22 Mg(p, γ)23 Al and 21 Na(p, γ)22 Mg reactions playa very important role.1–4) They possibly inﬂuence theproduction of γ-emitter 22 Na in Ne-rich novae.5,6) In
the present study, we aimed at directly investigating
proton resonant states in 23 Al and 22 Mg by the elastic scattering of 22 Mg and 22 Na RI beams on a thickproton target, respectively.
Previously, excited states in 23 Al were studied by
the 24 Mg(7 Li, 8 He)23 Al reaction,2) but there was nodirect measurement of proton resonant states in 23 Al
yet. Excited states in 22 Mg were investigated in many
experiments,4) including that on the elastic scattering of a 21 Na beam at 1.4 MeV/nucleon performed at
TRIUMF, and three proton resonance states at 6.332,
6.617 and 6.813 MeV were observed.5)
The experiment was carried out using the CNS radioactive ion beam separator (CRIB), as described
elsewhere.7,8) A 20 Ne8+ primary beam was accelerated up to an energy of 8.11 MeV/nucleon at the
RIKEN AVF cyclotron (K = 70) with an averageintensity of approximately 200 pnA. The primarybeam bombarded a 3 He gas target with a thickness of
0.36 mg/cm2 , where a 22 Mg secondary beam was produced by the 3 He(20 Ne, 22 Mg)n reaction. Fortunately,a 21 Na radioactive ion beam was also produced.
The radioactive beams were separated by the CRIB
with an energy degrader, 5.43-µm-thick Myler foil,
which was installed at the momentum dispersive focal
plane (F1) to eliminate light particles. Furthermore,an F1 horizontal slit was used to select 22 Mg particles
with a momentum deviation of 1%. After the energy
degradation, the energy of 22 Mg particles was determined to be 5.93 MeV/nucleon. At the same magnetic
rigidity (Bρ) setting, the energy of 21 Na particles wasdetermined to be 5.46 MeV/nucleon.
At the achromatic focal plane (F2), a setup forthe elastic scatterng measurement was installed inside a vacuum chamber.9) The setup considered of
two parallel-plate avalanche counters (PPACs), a thick
7.87 mg/cm2 (CH2 )n target and three sets of ∆E-E
silicon telescopes. The ﬁrst set of ∆E-E silicon telescopes was installed at 0◦ (covering a scattering angle
∗1
∗2
∗3
∗4
∗5
∗6

68

Center for Nuclear Study, University of Tokyo
Department of Physics, Rikkyo University
Department of Physics, Chun-Ang University, Korea
Department of Physics, University of Tokyo
Department of Physics, Kyushu University
Department of Physics, Yamagata University

from −5◦ to 5◦ ), consisting of a 75-µm-thick positionsensitive detector (PSD1) and two Si detectors witha thickness of 1.5 mm each. The second set was installed at 16◦ (covering a scattering angle from 11◦
to 21◦ ), consisting of a 75-µm-thick position-sensitive
detector (PSD2) and a Si detector with a thickness of
1.48 mm. The third set was installed at −23◦ (coveringa scattering angle from −18◦ to −28◦ ), consisting ofa 73-µm-thick position-sensitive detector (PSD3) anda Si detector with a thickness of 1.5 mm. As for PSD1,
double-sided strips (16 × 16 strips) were used to determine two-dimensional hit positions, while for PSD2and PSD3, only horizontal x strips were used.
On the secondary target, the beam spot widths were
15 mm (FWHM) horizontally and 11 mm (FWHM)
vertically. The horizontal and vertical angular widthsof the two beams were 28 mrad (FWHM) and 33 mrad
(FWHM), respectively. The energies of 22 Mg and 21 Na
beams were 4.38 MeV/nucleon and 4.00 MeV/nucleon
on the secondary target, respectively, and their width
was 0.12 MeV/nucleon (FWHM).
The protons pocoiling out of the (CH2 )n target wereaccumulated for about 53 hours. Furthermore, themeasurement was performed with an equivalent thickness of the C target to evaluate the background contribution of the reactions of beam particles with C atoms
in the (CH2 )n target. The proton energies were calibrated using secondary proton beams separated by
CRIB at several energy points.
At present, the center-of-mass energy (Ecm ) of elastic scattering was reconstructed, whose resolution isabout 30–50 keV (FWHM) with an error of 15–30 keV
as a function of the Ecm energies. Now, the R-matrix
analysis is in progress to reduce the resonance parameters of the observed resonant states.
References
1) J. A. Caggiano et al.: Phys. Rev. C 64, 025802 (2001).
2) N. Bateman et al.: Phys. Rev. C 63, 035803 (2001).
3) A. A. Chen et al.: Phys. Rev. C 63, 065807 (2001).
4) C. Ruiz et al.: Phys. Rev. C 65, 042801 (2002).
5) I. Iyudin et al.: Astron. Astrophys. 300, 422 (1995).
6) M. Wiescher et al.: J. Phys. G 25, 133 (1999).
7) S. Kubono et al.: Eur. Phys. J. A 13, 217 (2002).
8) T. Teranishi et al.: Phys. Lett. B 556, 27 (2003).
9) J. J. He et al.: CNS Ann. Rep. 2002, 1.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Study of the 26 Si(p, γ)27 P reaction by
the Coulomb dissociation method
Y. Togano,∗1 T. Gomi,∗1 T. Motobayashi, Y. Ando,∗1 N. Aoi, H. Baba,∗1 K. Demichi,∗1 Z. Elekes,
N. Fukuda, Zs. Fülöp,∗2 U. Futakami,∗1 H. Hasegawa,∗1 Y. Higurashi, K. Ieki,∗1 N. Imai, M. Ishihara,
K. Ishikawa,∗3 N. Iwasa,∗4 H. Iwasaki,∗5 S. Kanno,∗1 Y. Kondo,∗3 T. Kubo, S. Kubono,∗5 M. Kunibu,∗1
K. Kurita,∗1 Y. U. Matsuyama,∗1 S. Michimasa,∗5 T. Minemura, M. Miura,∗3 H. Murakami,∗1 T. Nakamura,∗3
M. Notani,∗5 S. Ota,∗6 A. Saito,∗1 H. Sakurai,∗7 M. Serata,∗1 S. Shimoura,∗5 T. Sugimoto,∗3 E. Takeshita,∗1
S. Takeuchi, K. Ue,∗7 K. Yamada,∗1 Y. Yanagisawa, K. Yoneda, and A. Yoshida
208Pb(27 P, p26 Si)208 Pb, Coulomb dissociation, Nuclear astrophysics
We have carried out an experiment to study theSi(p, γ)27 P reaction using the Coulomb dissociationof 27 P. The gamma decay width of the first excitedstate in 27 P was measured because of its astrophysicalinterest.
The 26 Si(p, γ)27 P reaction is one of the key reactions in the nucleosynthesis in Ne-rich novae. The rateof this reaction must be known to evaluate the amountof 26 Al (g.s.). This reaction is also important for estimating the mass evolution to heavier elements. The
27
P production in Ne-rich novae mainly depends onresonant capture via the first excited state in 27 P at
1.2 MeV, because the state is close to the Gamow window. Therefore, we aimed at determining the gamma
decay width of the first excited state in 27 P in orderto reveal the strength of the resonant capture in thisreaction.
The experiment was performed at the RIPS beamline at the RIKEN Accelerator Research Facility. The
secondary beam of 27 P at 57 MeV/nucleon was produced by the fragmentation of a 115 MeV/nucleon 36 Ar
beam on a 9 Be target. The beam of 27 P bombarded
a 125 mg/cm2 Pb target. The products of the breakup
reaction, 26 Si and proton, were detected using silicon
telescopes and a plastic scintillator hodoscope, respectively. Details of the experimental setup are describedin Ref. 1. The angle of products and the energy of 26 Si
were measured by the silicon telescopes. The time offlight of the proton was determined using the plastic
scintillator hodoscope.
The relative energy spectrum was obtained from themeasured momentum vectors of products. The preliminary spectrum is shown in Fig. 1. The peaks wereobserved at 0.34 MeV and 0.8 MeV which correspondrespectively to the first and second excited states at
1.2 MeV and 1.6 MeV in 27 P reported in Ref. 2. We
also found another peak at 1.2 MeV that did not correspond to any known state.
26

∗1
∗2
∗3
∗4
∗5
∗6
∗7

Rikkyo University
ATOMKI, Hungary
Tokyo Institute of Technology
Tohoku University
Center for Nuclear Study, University of Tokyo
Kyoto University
University of Tokyo

Fig. 1. Preliminary relative energy spectrum of the208
Pb(27 P, p26 Si)208 Pb reaction. The peak at 0.34 MeV
corresponds to the first excited state in 27 P at 1.2 MeV.

We obtained the cross section of the first excitedstate of 27 P to be 5 mb with a statistical error of
about 25%. Supposing that the spin and parity of
the first excited state in 27 P is 3/2+ , the transition
between the first excited state and the ground stateis by M1/E2 multipolarity. Since the E2 component
was strongly enhanced in the Coulomb dissociation,
the experimental cross section is exhausted via theE2 excitation. To extract the total gamma decay
width, the M1 component was estimated using themixing ratio, E2/M1 = 0.048, from the mirror transition in 27 Mg. The gamma decay width of the firstexcited state thus deduced preliminarily was determined to be 3.5 ± 0.6 (stat) meV. This result is consistent with the value estimated on the basis of a shellmodel calculation.2) It also indicates that this reaction does not contribute significantly to the amount of26
Al (g.s.).
References
1) T. Gomi et al.: RIKEN Accel. Prog. Rep. 36, 82 (2003).
2) J. A. Caggiano et al.: Phys. Rev. C 64, 025802 (2001).

69

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RIKEN Accel. Prog. Rep. 37 (2004)

One-neutron halo structure in 15 C
D. Q. Fang,∗1 T. Yamaguchi, T. Zheng,∗2 A. Ozawa, M. Chiba,∗3 R. Kanungo, T. Kato, K. Morimoto,
T. Ohnishi, T. Suda, Y. Yamaguchi,∗4 A. Yoshida, K. Yoshida, and I. TanihataMeasured reaction cross section, measured fragment momentum distribution, halo structure
Discrepancies have been found in the momentum
distribution and interaction cross section (σI ) measurements for 15 C.1) We measured the fragment momentum distribution and reaction cross section (σR ) of
14,15
C at 83 A MeV to study the halo structure in 15 C.
The experiment was performed at the Riken Projectile Fragment Separator (RIPS). The primary beamof 110 A MeV 22 Ne was used to produce the secondary
beams of 14,15 C. Before the carbon reaction target(370 mg/cm2 ) installed at F2, particle identiﬁcation
was carried out by the Bρ–∆E–TOF method. TOF
was determined from F1-PPAC and a plastic scintillator (0.5 mm thick) at F2. ∆E was measured using two
Si detectors (each 150 µm thick). After the reaction
target, the TOF–∆E–E method was used for particle
identiﬁcation. Another plastic (1.5 mm thick) at F3
gave the stop signal of the TOF from F2 to F3. Three
Si detectors (each 150 µm thick) were used to measure∆E. E was measured using a NaI(Tl) detector.
The fragment momentum distributions from 14,15 C
breakup are shown in Fig. 1. A Lorentzian function
was used to ﬁt 15 C → 14 C distributions. A Gaussianfunction was used to ﬁt 15 C → 13 C and 14 C → 13 C
distributions. The FWHMs were determined to be
71 ± 9 MeV/c (Fig. 1 (a)), 223 ± 28 MeV/c (Fig. 1 (b))
and 195 ± 21 MeV/c (Fig. 1 (c)) after unfolding theGaussian-shaped system resolution.
A few-body Glauber model analysis for the oneneutron removal process of 14,15 C was performed.2)
We assumed a core + n structure for 14,15 C. The
density distribution of the core was supposed to be
HO with its size parameter adjusted to reproduce σI
at high energies.1) The wave function of the valence
neutron was calculated by solving the eigenvalue problem in a Woods-Saxon potential. For 14 C, the calculated momentum distributions can reproduce the ex-

Fig. 1. Fragment longitudinal momentum distributions in
the projectile rest frame for 15 C → 14 C (a), 15 C → 13 C(b) and 14 C → 13 C (c).
∗1
∗2
∗3
∗4

70

Shanghai Institute of Nuclear Research, China
Department of Technical Physics, Peking University, China
Department of Physics, Tohoku University
Department of Physics, Niigata University

periment data well. For 15 C, contributions from different breakup sequences were considered. In the bestﬁtted results, the contribution of the d wave to a oneneutron removal cross section (σ1n ) was 4+10
−4 %. It isconsistent with the results from a previous experimentin which the d wave contributed only 2% to σ1n .3) Our
analysis suggests that the contribution from the 1d5/2
orbit in the ground state of 15 C is very small.
The σR values for 14 C and 15 C are determined to be1075 ± 61 mb and 1319 ± 40 mb, respectively. A strong
increase from 14,16 C is exhibited in σR measured at
83 A MeV for 15 C.4) The eﬀective density distributionof 15 C was extracted using the ﬁnite-range Glaubermodel.4) The HO plus v(p1/2 ) neutron was used forthe 14 C core with the p wave distribution obtained
from the above wave function calculation. The HO
size parameter was adjusted to reproduce the σR of
14
C at 83 A MeV. Then the depth of the potential waschanged arbitrarily in calculating the wave function of
the valence neutron so as to reproduce the σR of 15 C at
83 A MeV. The ﬁtted densities are compared with thecalculated s and d wave distributions in Fig. 2. A longtail is necessary to explain the measured σR of 15 C.
The extracted tail agrees with the s wave distribution
much better than the d wave. We can conclude thatthe s wave is dominant in the ground state of 15 C basedon the analysis of both σR and momentum distribution
data from this experiment. This is a strong evidenceof the halo structure in this nucleus.

Fig. 2. Density distribution of 15 C. The solid line is a bestfit result. The dotted and dashed lines show the calculated s and d wave distributions. The shaded area
represents the error of σR from both 15 C and 14 C.

References
1) A. Ozawa et al.: Nucl. Phys. A 691, 599 (2001).
2) T. Yamaguchi et al.: Nucl. Phys. A 724, 3 (2003).
3) V. Maddalena et al.: Nucl. Phys. A 682, 332c (2001).
4) T. Zheng et al.: Nucl. Phys. A 709, 103 (2002).

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RIKEN Accel. Prog. Rep. 37 (2004)

g-factor measurement for 19 N
D. Kameda,∗1 K. Asahi, H. Ueno, A. Yoshimi, H. Miyoshi,∗1 H. Watanabe, T. Haseyama, K. Shimada,∗1
G. Kato,∗1 S. Emori,∗1 G. Kijima,∗1 J. Murata,∗2 and Y. Kobayashi

NUCLEAR STRUCTURE, 19 N, Spin polarization, β-NMR method
In contrast to the well known observation that almost all of the measured nuclear magnetic moments
are found inside the Schmidt lines due to the core polarization eﬀect, the magnetic moment of 15 N and alsothat of 17 N1) fall outside the Schmidt lines. Considering the increased number of neutrons in the sd-shell,
the magnetic moment for 19 N should be even larger for
17
N. Shell models predict, in fact, that the magnetic
moment for 19 N is larger than that of 17 N as shown
later.
The experiment was performed at the RIKEN Accelerator Research Facility. The 19 N activity was obtained from the fragmentation of a 22 Ne projectile atan energy of 110 MeV/nucleon on a carbon target of
546 mg/cm thickness. By using the projectile-fragment
separator RIPS, the 19 N nuclide was separated fromother fragments. In order to produce spin polarization,
only those with emission angles 2.6◦ –6.0◦ and outgoing momenta 8.18–8.69 GeV/c were accepted. The
19
N fragments were implanted in a graphite stopper towhich a static ﬁeld B0 = 200.12 mT was applied andan RF ﬁeld was supplied to induce a nuclear magnetic
resonance.
In Fig. 1, the eﬀect of a spin ﬂip by the resonance is

19

Fig. 1. Observed NMR spectrum of N in a graphite stopper. Three data points are shown as filled circles. The
vertical axis is the up/down count ratio of β-rays detected by plastic scintillators which were placed aboveand below the stopper. The vertical bars on each pointshow the statistical error of the β-ray count. The horizontal bars are a sweep width over which the frequencyof the field was varied for each data point in order toflip the 19 N spin [the Adiabatic Fast Passage (AFP)
method].
∗1∗2

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

observed in the leftmost data point with a deviation of
3.2σ from the zero level, where the σ is a standard deviation. The result indicates that there is the g factor
for 19 N within the region of g = 0.58–0.64 which is derived from the sweep width of the frequency as shownin Fig. 1. The centroid of the resonance could be beyond the left side of the sweep region due to the ﬁnite
resonance width. The possible deviation mainly comesfrom the ﬁeld inhomogeneity, as shown in the Fig. 1,
and the ratio of the ﬁeld magnitude of the static ﬁeld
to that of the rf ﬁeld, of which the value is 0.25%.
These deviations are negligibly small compared withthe present accuracy of the g factor.
The present g factor for 19 N is signiﬁcantly smaller
than the shell model predictions.2) In Fig. 2, a systematic trend is observed: The shell models predict|g| factors as monotonically increasing with increasing
number of neutrons n in the sd shell. The experimental|g| certainly follows this trend up to n = 2 (i.e., 17 N).
The experimental |g| for 19 N, however, abruptly decreases. The reason for this anomalous n dependence
is not known.

Fig. 2. Experimental (circle with error bars) and theoretical (square) |g| factor for the odd-mass N isotopes. The
magnetic moment is obtained from µ = gµN I where I
and µN are the nuclear spin and nuclear magneton, respectively. The spin parity of 19 N was assumed to be
1/2− in the calculation.

References
1) H. Ueno et al.: Phys. Rev. C 53, 2142 (1996).
2) B. A. Brown, A. Etchengoyen, and W. D. Rae: Computer code OXBASH, Michigan State University Cyclotron Laboratory Report, No. 524 (1986).

71

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RIKEN Accel. Prog. Rep. 37 (2004)

Development of low energy 8 Li beam at CRIB
M. Kurata-Nishimura, S. Nishimura, T. Teranishi,∗1 M. Notani,∗1 J. J. He,∗1 H. Baba,∗2
S. Michimasa,∗1 S. Kubono,∗1 and I. Tanihata[Astrophysics, Nucleosynthesis, Unstable nuclei]
The inhomogeneous big bang model1,2) has succeeded in predicting the synthesis of heavy elements
in contrast to the standard primordial nucleosynthesis model which makes reasonably accurate predictions of the light element abundances. In the inhomogeneous big bang model, 4 He(t, γ)7 Li(n, γ)8 Li(α, n)11B(n, γ)12 B(βν)12 C is considered to be a dominant
ﬂow path to explain the synthesis of 12 C and heavy elements in the very early universe. Recently, it has also
been identiﬁed to play an important role in r-process
nucleosynthesis occurring in supernova explosions.3) In
both environments, it is claimed to determine the reaction cross section in a direct reaction with the centerof mass energy less than 1 MeV. In that sequence,the 8 Li(α, n)11 B reaction gives large ambiguity causedby the short life of 8 Li. Some previous experiments
were conducted to determine this reaction cross section4–6) ; however, the results of these experiments were
not in qualitative agreement with each other. Moreover, measurements of the low-energy cross section below 1 MeV/n, which is the most important energy region, have not been conducted yet due to diﬃculty ofhandling low-energy beams.
In RIKEN cyclotron, an in-ﬂight low-energy radioisotope beam separator7–9) (CRIB) has been constructed to study unstable nuclear structures and nuclear reactions for astrophysics, through a collaboration between RIKEN and the Center of Nuclear Study(CNS). Since the energy of the RI beam producedby the in-ﬂight method is almost equivalent that ofa primary beam which is more than a few MeV/n, it isnecessary to insert a thick degrader in the beam line to
reduce the energy to 1 MeV/n. It is expected that theenergy straggling and beam proﬁle degeneration will bea crucial problem. In this article, we will report resultsof an experiment to develop a low-energy 8 Li beam in
CRIB. In addition, the neutron background level will
be noted.
An unstable 8 Li beam is created by an inversed reaction of 7 Li(d, p)8 Li. The primary beam of 7 Li2+is accelerated to an energy of 3.14 MeV/nucleon by
the RIKEN AVF cyclotron with the beam current of
100 pnA. The primary beam is focused at the F0 planewhere deuteron gas target of 0.39 mg/cm2 is located.
A removable aluminum foil with a thickness of 40 µm
is placed upstream of the gas target cell in order toreduce the beam energy. The produced 8 Li beams are
∗1
∗2

72

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

separated from 7 Li in the D1 magnetic ﬁeld travelingto a momentum-dispersive focal plane (F1). The ionspath through an F1 slit are transported to the second focal plane (F2) where two delayed-line PPACs
and SSD are installed to identify ions and to measure the energy spread and beam proﬁle. Mylar foil
degraders with thickness of 0, 10, 29 and 50 µm areplaced on a stepping motor in front of the PPACs.
For the purpose of estimating the neutron backgroundlevel, four liquid scintillation counters are prepared;
three are placed near the F2 chamber and the other isplaced 6 m downstream from the F2 chamber.
The particle identiﬁcation without any degrader isshown in Fig. 1. The 8 Li ions are clearly separated
from 7 Li ion.
Several thicknesses of energy degrader are used inattempts to reduce 8 Li beam energy. The beam properties for each energy degrader conﬁguration are summarized in Table 1.
The maximum 8 Li beam intensity of 5.1 × 105 is
obtained for a 100 pnA 7 Li beam without any degrader. At the energy of 1.57 MeV corresponding
to Ecm = 0.52 MeV for the 8 Li(α, n)11 B reaction, the8
Li beam purity of 99.5% and the intensity of 4 × 104
is obtained. The energy straggling and beam proﬁleFig. 1. Particle identification of 8 Li. Horizontal axis andvertical axis indicate time of flight between two PPACs
and the energy deposit in the SSD, respectively. Twoclusters in the 8 Li region are known to be caused by the
problem of double timing triggers. Some ions shows
zero energy deposit on SSD due the relatively small
acceptance of SSD.

Table 1. Summary of 8 Li beam properties for several configurations.
8

Degrader

Li

Place

Material

T [µm]

Energy [MeV]

dE/E [%]

σx [mm]σy [mm]Purity [%]Intensity [cps]/100 pnA

no

no

no

15.3

1.29

16.1

12.8

78.6

5 × 105

F2

Mylar

10

13.0

1.40

17.1

14.1

98.7

4 × 104

F2

Mylar

29

9.21

2.55

19.9

17.8

99.5

4 × 104

F2

Mylar

50

1.57

21.40

29.6

24.9

99.5

4 × 104

F0

Al

40

4.22

11.3

—

26.6

57.0

3 × 104

could be improved by adapting a degrader at F1 andadjusting the slit size at F1 and F2.
Furthermore, the neutron background with the order of 1000 cps is expected from the primary target
through the 7 Li(d, n) reaction. However, it is foundto be 20 cps even at the side close to the primary target. In this case, signal to noise ratio of the neutron
can be estimated as 1/100 which is acceptable for thisexperiment.

2) N. Hata et al.: Phys. Rev. Lett. 75, 3977 (1995).
3) M. Terasawa et al.: Astrophys. J. 562, 470 (2001).
4) X. Gu et al.: Phys. Lett. B 343, 31 (1995).
5) R. N. Boyd et al.: Phys. Rev. Lett. 68, 1283 (1992).
6) Y. Mizoi et al.: Phys. Rev. C 6206, 5801 (2000).
7) S. Kubono et al.: Eur. Phys. J. A 13, 217 (2002).
8) T. Teranishi et al.: CNS-REP-39 (2001).
9) S. Watanabe et al.: CNS-REP-48 (2002).

References
1) M. J. Balbes et al.: Phys. Rev. Lett. 71, 3931 (1993).

73

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Production of low-energy secondary beam for secondary reactions
E. Ideguchi,∗1 H. Baba,∗2 T. Fukuchi,∗1 C. Ishida,∗3 H. Iwasaki,∗4 T. Komatsubara,∗5 T. Kubo,
M. Kurokawa, S. Michimasa,∗1 K. Morimoto, M. Niikura,∗1 T. Ohnishi, S. Ota,∗6 A. Ozawa,∗5
S. Shimoura,∗1 T. Suda, M. Tamaki,∗1 I. Tanihata, and K. Yoshida
NUCLEAR REACTION, 9 Be(37 P, xn)46−x K, Unstable nuclei
Studies of high-spin states in atomic nuclei byin-beam gamma-ray spectroscopy have provided detailed information on the nuclear structure. In suchstudies, high-spin states are achieved mostly througha fusion reaction using a combination of a stableisotope beam and a stable-isotope target, since large
angular momentum can be brought to the nucleus ofinterest in the reaction. However, nuclei produced in
the fusion reaction are limited, in many cases, to theproton-rich side relative to the β-stability line. In theneutron-rich nuclei, unprecedented phenomena such as
the disappearance of the shell gap1) and the onset ofa new magic number2) have recently been observed.
These phenomena are ascribable to the change of thenuclear structure on the neutron-rich side, but this region, particularly at high spin, have not been studied
well so far. It would be desirable to extend the experimental study of high-spin states and carry out a systematic investigation covering from the proton-rich to
the neutron-rich region. By utilizing a neutron-richbeam in the fusion reaction, nuclei will be producedin the neutron-rich side and the region available forhigh-spin studies will be largely expanded. In order toactualize this method, an experiment to produce a lowenergy secondary beam (∼6 MeV/nucleon), which isindispensable for inducing the fusion reaction, was performed at the RIKEN accelerator research facility.
In the experiment, a secondary 37 P beam was produced at the RIPS facility3) in RIKEN by the fragmentation reaction of an 40 Ar beam impinging on
a 9 Be target 1.5 mm thick. The primary 40 Ar beam of
63 MeV/nucleon with a typical intensity of 60 pnA wasprovided by the RIKEN Ring cyclotron. An aluminum
wedge with a mean thickness of 221 mg/cm2 placed at
the momentum-dispersive focal plane (F1) was used toachieve a clear isotope separation and to lower the energy of the fragment to 26 MeV/nucleon. The energy ofthe 37 P beam was further lowered to ∼6 MeV/nucleon
by placing an aluminum rotatable degrader 0.425 mm
thick at the achromatic focal plane (F2). The energy of the beam was optimized by adjusting the rotation angle of the degrader relative to the beam direction. By operating RIPS at the maximum values of momentum acceptance and solid angle, a typ∗1
∗2
∗3
∗4
∗5
∗6

74

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

ical intensity of 2.0 × 105 counts per second for the37
P beam was obtained at F2. Particle identiﬁcation of the secondary beam was carried out by thetime-of-ﬂight (TOF)-∆E method, and it was foundthat an almost pure 37 P beam was obtained. The
TOF and ∆E information was obtained from the timing of the plastic scintillator relative to the RF signal of the cyclotron and from the energy loss in the
0.5-mm-thick silicon detector placed at F2, respectively. The 37 P beam was transported to the ﬁnal
focal plane (F3) and irradiated on the secondary 9 Be
target 10 µm thick in order to induce the secondary fusion reaction, 9 Be(37 P, xn)46−x K. The intensity of the37
P beam at F3 was about 1.0×105 counts per second.
Two PPAC counters4) were placed up stream of thesecondary target in order to proﬁle the image and theincident angle of the beam on the target, as well as todetermine energy from TOF information relative to theplastic timing at F2, event by event. Another PPAC
counter was also placed down stream of the target todetect recoil nuclei produced in the secondary reaction
and to measure the TOF. Figure 1 shows the energy
spectrum of the 37 P beam at the secondary target position. The beam spot size (FWHM) at the target was
found to be 42 mm and 18 mm, respectively, in horizontal and vertical directions. Gamma rays emitted in
the secondary reaction were measured by the CNS Ge
detector array5) placed around the secondary target atangles between 70◦ and 110◦ . The analysis of the dataobtained for the secondary reaction is in progress.

Fig. 1. Energy spectrum of the 37 P beam at secondary target position deduced from TOF information.

References
1) T. Motobayashi et al.: Phys. Lett. B 346, 9 (1995).
2) A. Ozawa et al.: Phys. Rev. Lett. 84, 5493 (2000).
3) T. Kubo et al.: Nucl. Instrum. Methods B 461, 309(1992).
4) H. Kumagai et al.: Nucl. Instrum. Methods A 470, 562(2001).
5) S. Shimoura et al.: CNS Annu. Rep. 2001, 5.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Development of 17 N secondary beam II
A. Odahara,∗1 Y. Wakabayashi,∗2 Y. Gono,∗2 T. Fukuchi,∗3 N. Hokoiwa,∗2 M. Kibe,∗2 T. Teranishi,∗3
S. Kubono,∗3 M. Notani,∗3 Y. Yanagisawa, S. Michimasa,∗3 J. J. He,∗3 H. Iwasaki,∗4 S. Shimoura,∗3
H. Watanabe, T. Kishida, E. Ideguchi,∗3 H. Baba,∗5 S. Nishimura, M. Kurata-Nishimura,
J. Y. Moon,∗6 and S. Kato∗7[RI beam, γ-ray spectroscopy, nuclear structure]
A secondary beam of 17 N was developed using the
low-energy radioisotope beam separator (CRIB)1) of
the Center for Nuclear Study (CNS), University ofTokyo, in order to search for high-spin isomers in
N = 51 isotones. Since nuclei with Z < 40 of N = 51
isotones are close to the stability line, it is diﬃcult to
produce high-spin states of nuclei using reactions by
combinations of stable beams and targets. Therefore,
it is very eﬀective to use the radioisotope beam. Bymeans of the γ spectroscopy method, high-spin isomers
can be searched for in the nuclei 90 Y, 89 Sr and 88 Rb
produced by the α5n, αp5n and 2α3n channels of the82
Se + 17 N reaction, respectively.
High-spin isomers of N = 51 isotones are expected
to be shape isomers stemmed from a sudden shapechange from near spherical to an oblate shape. They
may also be expected to have stretch coupled conﬁgurations resulting from the breaking of a neutron
magic 50 core, as a similar type of isomerism observed in N = 83 isotones.2) The conﬁgurations ofthese isomers in N = 51 isotones are considered tobe [ν(d5/2 g7/2 h11/2 )πg9/2 2 ]39/2 − for odd nuclei and[ν(d5/2 g7/2 h11/2 )π(p1/2 g9/2 2 )]20 + for odd-odd nuclei.
A secondary 17 N beam was produced by using
the CRIB1) which consists of two dipole (D1, D2),
three quadrupole (Q1, Q2, Q3) and two small correction magnets (M1, M2). A 9 Be primary target of
2.3 mg/cm2 was bombarded by a 18 O8+ primary beamof 126.4 MeV to obtain a 17 N beam. An 18 O6+ beam
was accelerated by the AVF cyclotron in RIKEN. The
charge states of the beam particles were converted byusing C foil which was set before a bending magnet toeliminate 12 C4+ contamination in the primary beam.
The beam intensity was 0.4 pµA at the primary target.
A parallel plate avalanche counter (PPAC) was set
on a dispersive focal plane (F1) for beam monitoring.
In order to identify reaction products, a PPAC anda 1.5 mm thick Si detector were installed on an achromatic focal plane (F2). These detectors were locatedat 681 and 731 mm downstream of Q3, respectively.
Secondary target of 82 Se of 4.9 mg/cm2 was placed at1251 mm downstream of Q3. Two clover Ge detectors
∗1
∗2
∗3
∗4
∗5
∗6
∗7

Nishinippon Institute of Technology
Kyushu University
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Rikkyo University
Chung-Ang University, Korea
Yamagata University

Fig. 1. Projection spectrum of γγ coincidence.

were set at 40 mm apart from the secondary target
to measure γ-rays emitted from nuclei which were produced by the secondary fusion reaction. A plastic scintillator was placed at 597 mm downstream of the secondary target in order to detect the secondary beam.
The acceptance solid angle was set to be 5.6 msr bya slit downstream of F0. The energy of 17 N recoilingout of a primary target was 109.1 ± 0.8 MeV. A Bρvalue of D1 was set to be 0.886 Tm to select a 17 N7+beam. Momentum acceptance was restricted to 2.2%
by a rectangular slit at F1. The 18 O primary beam
was stopped by the slit at F1.
Particle identiﬁcation was performed by using energies of reaction products and time diﬀerences of RF
and F2-PPAC signals. The energy of 17 N7+ was deduced to be 104±2 MeV. As the Si detector was moved
out during the γ-ray measurement, 17 N7+ and 17 O7+
could not be separated. The intensity and fraction of
the 17 N7+ and 17 O7+ mixed beam were 1.5 × 105 particles/s and 33%, respectively.
A total number of events of 2.1 × 108 was collectedduring the measurement for 2.4 days. Data acquisition started when F2-PPAC and one Ge detector were
hit. A plastic scintillator signal was used to veto thesecondary beams passed through the target without
making a secondary reaction. Only the data with thesignals of the cocktail beam of 17 N and 17 O at F2 wereaccumulated. Although the background level originating from the thermal neutron capture γ-rays was 200
times higher than the counts of peaks coming from thesecondary fusion reaction, seven transitions belonging
to 92 Nb and 93 Nb were observed, as shown in Fig. 1.
References
1) S. Kubono et al.: Eur. Phys. J. A 13, 217 (2002).
2) Y. Gono et al.: Eur. Phys. J. A 13, 5 (2002).

75

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Electromagnetic transition matrix elements of proton-rich
46
Cr, 50 Fe, and 54 Ni studied by Coulomb excitation
K. Yamada,∗1 T. Motobayashi, N. Aoi, H. Baba,∗1 K. Demichi,∗1 Z. Elekes, J. Gibelin,∗2 T. Gomi,∗1
H. Hasegawa,∗1 N. Imai, H. Iwasaki,∗3 S. Kanno,∗1 T. Kubo, K. Kurita,∗1 Y. U. Matsuyama,∗1
S. Michimasa,∗4 T. Minemura, M. Notani,∗4 T. K. Onishi,∗3 H. J. Ong,∗3 S. Ota,∗5 A. Ozawa,∗6
A. Saito,∗1 H. Sakurai,∗3 S. Shimoura,∗4 E. Takeshita,∗1 S. Takeuchi, M. Tamaki,∗4
Y. Togano,∗1 Y. Yanagisawa, K. Yoneda,∗7 and I. Tanihata[NUCLEAR STRUCTURE, B(E2), Unstable nuclei, Coulomb excitation, Mn /Mp ]The measurement of proton as well as neutron multipole matrix elements in exotic nuclei is one of theincisive methods of studying the dynamical propertiesof nuclear states, and has received increased attention.
The proton and neutron multipole elements are deﬁned1) as
Mp(n) (Tz ) = Jf T Tz Σp(n) riλ Yλ (Ωi )Ji T Tz
1(1)
= M0 (Tz ) ± M1 (Tz ) ,2
where M0 (Tz ) and M1 (Tz ) are the matrix elements in
an isospin representation. The multipole matrix element Mp is related to the reduced electromagnetic
matrix element B(Eλ; Ji → Jf ) by
B(Eλ; Ji → Jf ) = |Mp (Tz )|2/(2Ji + 1).

(2)

Therefore, the proton multipole matrix element Mp
can be determined via the measurement of the electromagnetic transition strength. On the other hand, theneutron multipole matrix element Mn can be obtainedby comparing electromagnetic transitions in mirror nuclei.1)
As reported previously,2) we performed the ﬁrst+
measurement of B(E2; 0+g.s. → 21 ) in the proton-richnuclei of 46 Cr, 50 Fe, and 54 Ni in order to clarify the
structures around the Z = 20–28 region systematically.
The details of the experiment were described in Ref. 2.
Figure 1 shows the Doppler-corrected energy spectra of γ rays from 46 Cr, 50 Fe, and 54 Ni. A single distinct peak is observed in each spectrum of 46 Cr and50
Fe; their level energies are consistent with resultsof recent studies.3,4) In the spectrum of 54 Ni, we canﬁnd a peak at energy of around 1400 keV which corresponds to the unknown level of 54 Ni. In order to+extract B(E2; 0+g.s. → 21 ) values, these spectra wereﬁtted by the function y = af (Eγ ) + exp(−b × Eγ + c),
where f (Eγ ) is the line shape obtained by Monte-Carlocalculation. The results of ﬁtting for 46 Cr and 50 Fe
are shown by curves in Fig. 1. The matrix elements
∗1
∗2
∗3
∗4
∗5
∗6
∗7

76

Department of Physics, Rikkyo University
Institut de Physique Nucléaire, France
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
Department of Physics, Kyoto University
Institute of Physics, University of Tsukuba
National Superconducting Cyclotron Laboratory, Michigan
State University

Fig. 1. The Doppler-corrected γ spectra from Coulomb excitation of 46 Cr, 50 Fe, and 54 Ni.
+
B(E2; 0+g.s. → 21 ) were derived from the γ yield withthe help of a distorted-wave calculation, assuming pure
E2 Coulomb excitation. The preliminary results for+
B(E2; 0+g.s. → 21 ) were 19.9 ± 4.2 W.u. and 25.8 ±46
4.9 W.u. for Cr and 50 Fe, respectively. These errors
include the ambiguities associated with the ﬁtting procedure and common systematic uncertainties. In order
to examine the validity of our method, B(E2; 0+g.s. →
44
48
52
2+
)
of
Ti,
Cr,
and
Fe
in
the
secondarybeam
1
was extracted and compared with known spectroscopic
information. The present results of 21.9 ± 2.8 W.u.
and 19.2 ± 3.5 W.u. for 44 Ti and 48 Cr are considerably+
variant to their adopted B(E2; 0+g.s. → 21 ) values of
13 ± 4 W.u. and 31 ± 4 W.u., respectively.
However, the result of 16.4 ± 2.1 W.u. for 52 Fe isconsistent with a recent measurement by Yurkewicz et+al.,5) which gives B(E2; 0+g.s. → 2 ) = 14.2 ± 1.8 W.u.
+
Comparing the present results of B(E2; 0+g.s. → 21 )with those of mirror nuclei, we can obtain Mn /Mp values of 0.99 ± 0.11 and 0.88 ± 0.09 for 46 Cr and 50 Fe,
respectively. Both the Mn /Mp values are close to N/Z,
suggesting collective aspects of these nuclei. Detailed
comparisons of the present results and theoretical calculations are under way.

References
1) A. M. Bernstein et al.: Phys. Rev. Lett. 42, 425 (1979).
2) K. Yamada et al.: RIKEN Accel. Prog. Rep. 36, 85(2003).
3) P. E. Garrett et al.: Phys. Rev. Lett. 87, 132502 (2001).
4) S. M. Lenzi et al.: Phys. Rev. Lett. 87, 122501 (2001).
5) K. L. Yurkewicz et al.: Phys. Rev. to be published.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Intermediate-energy Coulomb excitation ofneutron-rich Ge isotopes around N = 50
H. Iwasaki,∗1 N. Aoi, S. Takeuchi, S. Ota,∗2 H. Sakurai,∗1 M. Tamaki,∗3 T. K. Onishi,∗1 E. Takeshita,∗4
H. J. Ong,∗1 N. Iwasa,∗5 H. Baba,∗4 Z. Elekes, T. Fukuchi,∗3 Y. Ichikawa,∗1 M. Ishihara, S. Kanno,∗4
R. Kanungo, S. Kawai,∗4 T. Kubo, K. Kurita,∗4 S. Michimasa,∗3 T. Motobayashi, M. Niikura,∗3 A. Saito,∗4
Y. Satou,∗6 S. Shimoura,∗3 H. Suzuki,∗1 M. K. Suzuki,∗1 Y. Togano,∗4 and Y. Yanagisawa

NUCLEAR REACTIONS: 76,78,80,82 Ge + Pb, Coulomb excitation
We have studied intermediate-energy Coulomb excitation of neutron-rich Ge isotopes around N = 50 using secondary beams of 76–82 Ge incident on Pb and C
targets. Among the various reactions recently appliedfor γ-ray spectroscopy with radioactive-ion beams,1–6)
Coulomb excitation aﬀords unique opportunities formeasuring both energies and transition probabilities
B(E2) for the low-lying 2+ states. The aim of thepresent experiment is to investigate such E2 properties of the neutron-rich Ge isotopes, which enable us todepict systematic trends of the collective behavior toward the neutron magic number N = 50. In addition,
two-step excitation at an intermediate energy has beenstudied to examine a possible access to higher excitedstates. Here, we report the experimental arrangement.
The experiment was performed at the RIPS beamline in RIKEN. The radioactive beams of 76–82 Ge were
produced by fragmentation of a 63 A MeV 86 Kr beam
on a 66.2-mg/cm2 -thick 9 Be target. A maximum intensity of 100 pnA was achieved for the primary 86 Kr
beam, owing to the recently developed acceleration
scheme of the RRC with the RFQ+RILAC+CSM injection system. The reaction fragments were collected
and analyzed by RIPS. As an energy degrader, weused a curved aluminum plate, which is equivalent inthickness along the beam line to a 65 mg/cm2 wedgeshaped degrader. Particle identiﬁcation of the incident beam was carried out event-by-event by measuring magnetic rigidity (Bρ), time-of-ﬂight (TOF), andenergy loss (∆E). The positions at the momentumdispersive focal plane of RIPS were measured by a parallel plate avalanche counter (PPAC) to determine theBρ value. The TOF between the production target
and the ﬁnal focal plane (F3) of RIPS was obtained
from the RF signal of the accelerator and the 0.01-mmthick plastic scintillator placed at F3. The ∆E information was provided by the 100-µm-thick silicon detector placed at the second focal plane of RIPS. The accuracy in the particle identiﬁcation of the Ge isotopes wasaround 0.9% and 0.2% (r.m.s.), respectively, for the Z
and A/Z determinations. The typical secondary-beam
∗1
∗2
∗3
∗4
∗5
∗6

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

intensities were around 6 kcps for 76 Ge, 2 kcps for 78 Ge,
1 kcps for 80 Ge, and 100 cps for 82 Ge in the separate Bρsettings optimized for each isotope. Pb targets wereplaced at F3 and were used to excite the projectiles.
The position and incident angles of the beam at F3
were measured by two sets of PPAC placed upstreamof the target. To evaluate the possible contributionsof nuclear excitations, additional measurements with
C targets were also performed.
De-excitation γ rays were detected by an array of 158
NaI(Tl) scintillators7) surrounding the target. The energy and eﬃciency calibrations of the array were madeusing standard 22 Na, 60 Co, and 137 Cs sources. The
overall photopeak eﬃciency and energy resolution were
found to be 30% and 9% (FWHM), respectively, fora 661-keV γ ray as measured with the 137 Cs source.
Scattered particles were detected by a Si telescope
and a NaI(Tl) calorimeter located 75 cm and 1.5 m
downstream of the secondary target. The Si telescopeconsisted of 16 silicon detectors placed in a 4×4 matrix.
The size of each detector was 5 cm×5 cm×325 µm. The
NaI(Tl) calorimeter, the details of which are described
elsewhere,8) comprised 132 NaI(Tl) crystals arranged
in a 12 × 12 matrix except for three crystals at each corner. Each crystal has a rectangular shape with the sizeof 31 × 31 × 50 mm3 . The Si telescope provided energyloss (∆E) information, while the NaI(Tl) calorimeter
served as an E counter. The atomic number of theoutgoing particles was thus identiﬁed by the ∆E-E
method. The whole counter was located in a vacuum
chamber to minimize the energy loss in the material between the Si and NaI(Tl) detectors. The present setup
covered a solid angle of approximately 8 degrees. The
scattering angle was determined by the hit positions in
the two PPAC at F3 and the NaI(Tl) calorimeter.
An analysis of the data is now in progress.
References
1) T. Motobayashi et al.: Phys. Lett. B 346, 9 (1994).
2) H. Iwasaki et al.: Phys. Lett. B 491, 8 (2000).
3) T. Glasmacher et al.: Nucl. Phys. A 693, 90 (2001).
4) K. Yoneda et al.: Phys. Lett. B 499, 233 (2001).
5) F. Azaiez: Nucl. Phys. A 704, 37c (2002).
6) Y. Yanagisawa et al.: Phys. Lett. B 566, 84 (2003).
7) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 36, 148(2003).
8) M. Tamaki et al.: CNS-REP-59, 76 (2003).

77

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RIKEN Accel. Prog. Rep. 37 (2004)

Production cross sections of neutron-rich Ca and Ni isotopes
formed by fragmentation of a 63 A MeV 86 Kr beam
H. Iwasaki,∗1 H. Nishino,∗1 K. Tsurusaki,∗1 H. Sakurai,∗1 T. K. Onishi,∗1 N. Aoi, E. Takeshita,∗2 Y. Ichikawa,∗1
H. Baba,∗2 Z. Elekes, T. Fukuchi,∗3 M. Ishihara, N. Iwasa,∗4 S. Kanno,∗2 R. Kanungo, S. Kawai,∗2 T. Kubo,
K. Kurita,∗2 S. Michimasa,∗3 T. Motobayashi, M. Niikura,∗3 H. J. Ong,∗1 S. Ota,∗5 A. Saito,∗2 Y. Satou,∗6
S. Shimoura,∗3 H. Suzuki,∗1 M. K. Suzuki,∗1 S. Takeuchi, M. Tamaki,∗3 Y. Togano,∗2 and Y. Yanagisawa

NUCLEAR REACTIONS: 9 Be(86 Kr, X), E(86 Kr) = 63 A MeV; Measured production crosssections of 51−53 Ca and 72−75 Ni
We have measured production cross sections ofneutron-rich nuclei formed by the fragmentation of a
63 A MeV 86 Kr beam. Previous studies1,2) have investigated 86 Kr-induced reactions with 9 Be targets at
500 A MeV1) and 66 A MeV.2) They reported production cross sections of neutron-rich nuclei along the
N = 50 line and estimated the cross section for the
doubly magic nucleus 78 Ni. The present work extends
the experimental information to neutron-rich Ca andNi isotopes, which allows us to examine the feasibilityof the secondary-beam experiments with these nuclei.
The experiment was performed using a 86 Kr primary beam accelerated up to 63 A MeV by the RIKEN
Ring Cyclotron (RRC) incident upon a 66.2-mg/cm2 thick 9 Be target. The linear accelerator complex of the
RFQ+RILAC+CSM scheme was used as an injector to
RRC, which facilitated an intense 86 Kr beam with amaximum intensity of 100 pnA.
The reaction fragments were collected and analyzed
by the RIPS spectrometer. The momentum acceptance and solid angle of RIPS were set at 0.5% and
5 msr, respectively. The fragments were transported
to the ﬁnal focal plane (F3) of RIPS and stopped infour layers of 0.5-mm-thick silicon detectors. The arrival timing at F3 was measured by a parallel plateavalanche counter (PPAC) set immediately upstreamof the silicon detectors.
Particle identiﬁcation of the fragments was performed on the basis of time-of-ﬂight (TOF), energy
loss (∆E), and total kinetic energy (TKE) measurements. The TOF was determined from the RF signalof the accelerator and the PPAC. The ∆E information was obtained by the ﬁrst silicon detector, while
the whole detectors provided the TKE measurement.
Five diﬀerent settings of magnetic rigidity in therange of 2.85–3.03 Tm were employed to obtain diﬀerential cross sections. The production cross section foreach fragment was determined by a ﬁt of the observed
momentum distribution to an asymmetric Gaussian
distribution.
∗1
∗2
∗3
∗4
∗5
∗6

78

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

Figure 1 shows the production cross sections obtained for neutron-rich Ca and Ni isotopes. The data
are also compared with the production cross sectionsin the 238 U-ﬁssion reaction3) as well as the results ofthe empirical parametrization (EPAX2).4) The 86 Krinduced cross sections are smaller than the 238 U-ﬁssion
cross sections by more than two orders of magnitude.
It is also found that the 86 Kr-induced cross sections
have large mass-number (or N/Z ratio) dependence,even stronger than that of the EPAX2 predictions.
Further investigation is of great importance for establishing a reliable prediction toward very neutron-richnuclei such as 78 Ni.

Fig. 1. Production cross sections of a) Ca and b) Ni isotopes plotted as a function of mass number (A).

References
1) M. Weber et al.: Nucl. Phys. A 578, 659 (1994).
2) N. Aoi et al.: RIKEN Accel. Prog. Rep. 35, 75 (2002).
3) M. Bernas: AIP Conf. Proc. 455, 664 (1998).
4) K. Sümmerer and B. Blank: Phys. Rev. C 61, 034607(2000).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Lifetime of a new high-spin isomer in 150 Dy
H. Watanabe, Y. Wakabayashi,∗1 Y. Gono,∗1 T. Fukuchi,∗2 H. Ueno, W. Sato,∗3 A. Yoshimi, D. Kameda,∗4
H. Miyoshi,∗4 T. Kishida, Y. Kobayashi, T. Morikawa,∗1 S. Motomura, O. Kashiyama,∗1
K. Saito,∗1 A. Odahara,∗5 and K. Asahi ∗4NUCLEAR STRUCTURE, 150 Dy, High-spin isomer, Lifetimes
High-spin states in 150 Dy have been studied using
two types of experiments. In the first experiment, thenucleus 150 Dy was produced via the 141 Pr(16 O, p6n)
reaction with an energy of 165 MeV provided by the
SF cyclotron at the Center for Nuclear Study, University of Tokyo. Five HPGe detectors with BGO
anti-Compton shields were arranged around the target. The experimental data were acquired when atleast two Compton-suppressed Ge detectors were fired
concurrently. Figure 1 shows a partial decay scheme
confirmed in this experiment. The second experiment
was carried out with a 6 mg/cm2 natural Mg target
irradiated by a 132 Xe beam accelerated up to an energy of 7.0 MeV/u by the RIKEN Ring Cyclotron. The
beam burst was pulsed with an interval of 1 µs and awidth of ≤ 1 ns. The reaction products which recoiled
out the target with a mean velocity of 0.07c were gathered on a lead stopper placed 7 cm downstream fromthe target. It took approximately 3 ns for the recoil nuclei to pass between the target and the stopper. The
production target was shielded by lead blocks so thatthe prompt γ rays were not observed by Ge detectors.
The combination of the pulsed beam and the recoilshadow method1) with the inverse-kinematic reaction
allowed us to measure only γ rays emitted via isomericstates whose half-lives ranged from a few nanoseconds
to sub microseconds. Five HPGe detectors were used
to measure the delayed γ rays from the stopper position.
Comparing the γ-γ-gated spectra for 150 Dy measured in both experiments, the γ rays deexciting thestates higher than the Eex = 10.3 MeV level could beclearly observed in the first experiment (Fig. 2 (A)),
while only the transitions below that state were detected with the recoil-shadowing setup (Fig. 2 (B)).
This indicates that the 10.3 MeV state has a half-lifeof more than a few nanoseconds. The half-life of thisisomeric state has been determined to be T1/2 = 1.6 ±0.6 ns using the conventional centroid-shift method.2)

Fig. 2. γ-γ coincidence spectra for 150 Dy measured at (A)the target position in the ﬁrst experiment, (B) the stopper position with the recoil-shadowing geometry in thesecond experiment. Both ﬁgures were created by summing up spectra gated by 742, 206, 1455, 1346 keVtransitions. The energies are noted for the γ rays
below (open triangle) and above (solid triangle) the
Eex = 10.3 MeV state in 150 Dy.
Fig. 1. Partial level scheme of 150 Dy.
∗1
∗2
∗3
∗4
∗5

References
Department of Physics, Kyushu University
Center for Nuclear Study, University of Tokyo
Graduate School of Science, Osaka University
Tokyo Institute of Technology
Nishinippon Institute of Technology

1) J. Thirion and V. L. Telegdi: Phys. Rev. 92, 1253
(1953).
2) W. Andrejtscheﬀ et al.: Nucl. Instrum. Methods 204,
123 (1982).

79

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RIKEN Accel. Prog. Rep. 37 (2004)

Production and decay properties of 272 111 and its daughter nuclei
K. Morita, K. Morimoto, D. Kaji, S. Goto, H. Haba, E. Ideguchi, J. C. Peter, R. Kanungo, K. Katori,
H. Koura, H. Kudo, T. Ohnishi, A. Ozawa, T. Suda, K. Sueki, I. Tanihata, F. Tokanai,
H. Xu, A. V. Yeremin, A. Yoneda, A. Yoshida, Y.-L. Zhao, and T. Zheng
272
111, production and decay, excitation function, gas-ﬁlled recoil separator
The search for the heaviest elements is one of themost important challenges in nuclear physics. We installed a gas-ﬁlled recoil separator (GARIS)1) for the
research on the heaviest elements at an experimental
hall of the RIKEN Linear Accelerator Facility. As theﬁrst attempt using the separator, we studied the production and decay of an isotope 271 Ds (Z = 110) using
the 208 Pb + 64 Ni → 271 Ds + n reaction in 2002.2) In
the present work, we investigated the production anddecay of 272 111 using 209 Bi + 64 Ni → 272 111 + n reaction. The synthesis of this nuclide was reported by
Hofmann et al.3,4) using the same reaction as that in
the present work. The present result presents the ﬁrst
clear conﬁrmation for the discovery of 272 111 and its
α-decay products, 264 Bh and 268 Mt.
The measurement was made at three diﬀerent
beam energies, 320, 323 and 326 MeV. The reaction
products in ﬂight were separated from the incident
beam through GARIS. The products were then implanted into the position-sensitive semiconductor detector placed at the focus of GARIS. The energy andposition signals from implantations and subsequent decays of the products were used for data analysis. Targets were prepared by vacuum evaporation of metallic
bismuth on carbon backing foils of 30 µg/cm2 thickness. The thickness of the bismuth layer was approximately 280 µg/cm2 . The targets were covered by
a 10-µg/cm2 -thick carbon to protect the target fromsputtering. Other experimental setups were almost thesame as those described in Ref. 2.
We have observed 14 α-decay chains in total, whichwere assigned, on the basis of their energies and timecorrelations, to subsequent decays from 272 111 produced in the 209 Bi(64 Ni, 1n) reaction. The decay chainsobserved in the present experiment are summarized
in Fig. 1. The numbers in parenthesis in the ﬁgure
denote the numbers of observed events. Three decay
chains ended by spontaneous ﬁssion decays. The ﬁssion events are also indicated in the ﬁgure. Half-lives
and α-decay energies measured in the present experiment for 272 111, 264 Bh, and 268 Mt are shown in theﬁgure. The observed half-life of 272 111, 3.8+1.4−0.8 ms, ismore than two times longer than the value of 1.6+1.1−0.5 ms
reported in Ref. 4, while that of 268 Mt, 21+8
ms,
is two−5msreportedintimes shorter than the value of 42+29−12
the reference.
Cross sections of the 209 Bi(64 Ni, 1n) reaction werededuced from the numbers of the observed events,

80

Fig. 1. Summary of the observed decay chains. The numbers in parenthesis denote the numbers of observed
events.

target thicknesses, beam doses, and the eﬃciency of
GARIS. Results are summarized in Table 1. The ﬁrst
three decay chains are excluded from the analysis of
excitation function because of the target deterioration
occurring for those events. The eﬃciency of GARIS
was assumed to be 80%. In Table 1, Elab denotes the
projectile energy at the middle of the target. The errors in the cross sections are only statistical ones at
68% conﬁdence level. The cross section value obtainedin the present experiment agrees well with the value
reported in Ref. 4.
Table 1. Summary of the reaction of 64 Ni on 209 Bi.
Eproj
MeV

Thickness§1µg/cm2

§2
Elab
MeV

dose
1018

Observed
events

σ
pb

320.0
323.0
326.0

250
290
300

317.5
320.3
323.2

2.0
4.9
2.5

3
8
0

2.6+2.3−1.5
2.5+1.2−0.9
0.0+1.1
−0.0

§1
§2

average target thickness
at the middle of the target

References
1) K. Morita et al.: RIKEN Accel. Prog. Rep. 36, 196(2003).
2) K. Morita et al.: RIKEN Accel. Prog. Rep. 36, 90(2003); RIKEN Accel. Prog. Rep. 36, 91 (2003).
3) S. Hofmann et al.: Z. Phys. A 350, 281 (1995).
4) S. Hofmann et al.: Eur. Phys. J. A 14, 147 (2002).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Electron scattering from unstable nuclei by a novel SCRIT method
T. Suda, M. Wakasugi, T. Koseki, T. Emoto, T. Ohnishi, H. Takeda, and K. Kurita∗[NUCLEAR STRUCTURE, Unstable nuclei, electron scattering, SCRIT]
Electron scattering is one of the most precise probes
for studing the internal structure of atomic nuclei. In
particular, elastic electron scattering provides precise
spatial charge distribution in a nucleus, which plays
an essential role in our understanding of the nuclear
structure.
We have been discussing possible ways of realizing
electron scattering oﬀ radioactive isotopes (RI) in order to study their internal structure.1–3) Recently, anovel scheme has been proposed, which employs a wellknown ion-trapping phenomenon in electron storagerings at synchrotron radiation (SR) facilities. Ion trapping is a phenomenon where ionized residual gases byan electron beam are trapped by the circulating beamitself. It is known that this ion trapping eﬀect seriously
reduces the performances of the SR facilities, such as
causing shorter beam lifetime and beam instability.
Our novel method is to produce a localized RI target
on the electron beam by the ion trapping eﬀect in astorage ring, SCRIT (Self Conﬁned RI Target).4,5) RI
ions are injected from an external ion source.
Numerical simulations have shown that the SCRIT
system may provide suﬃciently high luminosity forelastic electron scattering: 1028 /cm2 /s being achievable for 108 /s ion injection with a 500 mA electron
beam current.
The following issues, however, have to be examined
experimentally.
• Does the SCRIT concept really work?
• Can we determine the luminosity accurately?
• Does the detection system properly work near ahigh-current storaged beam such as 500 mA?
A test experiment is to be carried out at an existing electron storage ring, KSR, at Kyoto University.
A SCRIT system equipped with an electron detection
system has been recently constructed for this experiment.
The SCRIT system consists of an ion source for (stable) Sn nucleus and electrodes placed along the beamline for longitudinal ion trapping. The externally injected ions are trapped transversely by the circulating electron beam, and longitudinally by the electrodes
placed along the beam line. The electron detection system consists of a drift chamber, a set of plastic scintillators and calorimeters, as shown in Fig. 1. They
are arranged to detect elastically scattered electrons
in the angular range of 30–80 degrees from a spatially∗Fig. 1. SCRIT chamber with planned detection system.
The ion source is not shown.

extended SCRIT of approximately 15 cm.
The luminosity is monitored by detecting bremsstrahlung γ-ray downstream of the straight section, where
the SCRIT system is installed.
The momentum transfer under this kinematics with
100 MeV stored electron beam corresponds to 50–
120 MeV/c, where the elastic cross section for Sn islarger than 100 mb/sr. The maximum counting rate of
the e+Sn elastic scattering is expected to be 1/s forthe expected luminosity of 1025 /cm2 /s. The SCRIT
system is ready to be installed at one of the straightsections of KSR in the beginning of 2004.
In the future, we plan to install a recoiled-ion detection system, as shown in Fig. 1. By taking coincidences with the electron arm, the elastic scattering
events can be unambiguously identiﬁed. In addition,
the time-of-ﬂight information of recoiled ions provides
their mass, since one knows the recoil momentum simply from the electron scattering angle. The recoiledion detector, where an MCP is a candidate, must not
face the circulating beam directly in order to avoid expected backgrounds of UV lights from SR and Moeller
electrons. Instead, MCPs detect secondary electrons
emitted from a metal foil that catches the recoiled ions.
References
1) T. Suda et al.: RIKEN Accel. Prog. Rep. 33, 52 (2000).
2) T. Suda et al.: RIKEN Accel. Prog. Rep. 34, 49 (2001).
3) T. Suda: A proposal for RIKEN RI Beam Factory (F0123, 2001).
4) M. Wakasugi: to be published in Proc. Int. Workshop on
Beam Cooling and Related Topics, Yamanashi, 2003-5,
in press.
5) M. Wakasugi: Proc. 14th Symp. on Accelerator Scienceand Technology, Tsukuba, 2003-12, in press.

Rikkyo Univesity81Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Development of liquid hydrogen target for
EPR experiment at SMART
T. Ikeda,∗1 T. Saito,∗2 H. Sakai,∗2 T. Uesaka,∗3 T. Kawabata,∗3 K. Yako,∗2 and K. Itoh ∗1
Einstein Podolsky Rosen (EPR) paradox is famousas one of the problems of quantum mechanics. We
have challenged this problem by measuring the spincorrelation of a spin-singlet proton pair produced via
the (d, 2 He) reaction at intermediate energy.1)
As a production target in this investigation, a hydrogen target is most appropriate because of its simplicity
and its liability to the spin and isospin ﬂips. Thus, wehave developed a liquid hydrogen target for this measurement.
The target consisted of a cyrogenic refrigerator, atarget cell, a thermal shield, and driving gears for moving and rotating the target (Fig. 1). The target cell was
attached to the cold head of the cryogenic refrigerator
and placed in the scattering chamber of the E4 experimental area. The cell used was made of aluminum toavoid unnecessary activation and to keep the thermal
conductivity high.
From the estimated production rate of 2 He and trueto-accidental coincidence ratio under the actual experimental setup, it was determined that the thicknessof the target was 70 mg/cm2 . Aramid foils of 20 mm
diameter and 12.5 µm thickness were used as the windows of the target.
The thermal shield made of aluminum attached tothe ﬁrst stage of the refrigerator prevented the target
cell from the eﬀect of thermal radiation from surrounding materials at room temperature.
This target was used in the experiment for 270 MeV
deutron beams. The operation temperature and innerpressure of the liquid hydrogen target were 15 K and

0.4 atm, respectively.
Figure 2 shows the target inner pressure and temperature during the experiment. The peaks of this graphappeared when the target was moved. The cause ofthis phenomenon is not known yet.
This graph indicates that the ﬂuctuation of target
temperature was small for a long time; hence, the effects of beams and thermal radiation were very small.
It is possible to use this target for a long time.
Figure 3 shows the excitation energy spectrum ofFig. 1. Liquid hydrogen target system.

Fig. 3. Excitation energy spectrum of remaining neutron.
The upper line indicates the spectrum of the liquid hydrogen target, while the lower one indicates the spectrum of the empty target cell.

∗1
∗2
∗3

82

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

Fig. 2. Target temperature, inner pressure and vacuum degree in scattering chamber.

the remaining neutron of the H(d, 2 He)n reaction. The
spectra with and without liquid hydrogen in the target
cell were compared. We observe from this ﬁgure thatthe ratio of true events from liquid hydrogen to background events from the aramid foil window is morethan 100; thus, the background from the aramid foil is
suﬃciently small to be ignored in this experiment.

Hence, it is concluded that the target has a highstability and a high S/N ratio in the EPR paradox
experiment.
References
1) T. Saito et al.: RIKEN Accel. Prog. Rep. 37, 45 (2004).

83

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RIKEN Accel. Prog. Rep. 37 (2004)

Evidence for a deeply bound kaonic system K − ppn in the4
He (stopped K − , n) reaction†
H. Outa, H. Bhang,∗1 G. Flanklin,∗2 K. Gomikawa,∗3 R. S. Hayano,∗3 T. Hayashi,∗4 M. Iwasaki,
K. Ishikawa,∗4 S. Ishimoto,∗5 K. Itahashi, T. Katayama,∗4 Y. Kondo,∗4 Y. Matsuda, T. Nakamura,∗4 S. Okada,B. Quinn,∗2 M. Sato,∗4 M. Shindo,∗3 H. So,∗1 P. Strasser, T. Sugimoto,∗4 K. Suzuki,∗6 S. Suzuki,∗5 T. Suzuki,∗3
D. Tomono,∗4 A. M. Vinodkumar,∗4 E. Widmann,∗3 T. Yamazaki, and T. Yoneyama∗4[NUCLEAR STRUCTURE, Kaon-baryon interactions, Chiral symmetries]
The kaonic hydrogen X-ray measurement at KEK1)
strongly suggests the attraction of the KN interaction in the I = 0 channel. Now Λ(1405) can be interpreted as a bound state of K − and a proton. Recently, Akaishi and Yamazaki developed a phenomenological KN interaction using the KN scattering lengthand energy/width of Λ(1405) and predicted that very
deeply bound kaonic nuclear states — BK ≥ 100 MeV— are formed in light nuclei. Due to its strong binding,a major K + N → Σ + π decay channel is forbidden;
hence the state is considered to have a narrow widthof Γ ∼ 30 MeV.2) In addition, due to the K − p strong
attraction, the kaonic nuclei forms an extremely dense
system with a central density of 8–10 times the normal
nuclear density,3) where we can expect the restorationof the chiral symmetry.
In the present experiment, we measured the energy
spectrum of neuron by means of TOF from the 4 He
(stopped K − , n) reaction. If the narrow bound state ofK − ppn is formed, a mono-energetic neutron should beemitted via the K − + 4 He → K − ppn+n reaction.4) We
placed 2 m3 of plastic scintillation counter arrays at 2 mfrom the helium target for neutron TOF measurement.
Absolute timing calibration was carried out using γ
rays and an overall resolution of ∆(1/β) = 0.04(σ) was
achieved, which corresponds to σ = 6 MeV neutron energy resolution at pn ∼ 500 MeV/c. We also requiredthat a charged particle is emitted from the target region in the trigger level. Both the incoming kaon andoutgoing charged particle tracks were measured by thedrift chambers and the reaction point was determinedby the vertex between the two trajectories. By determining the distance of the closest approach (DCA) of
the two trajectories and selecting DCA = 0 events,
we can detect charged pions from the weak decay ofhyperons (Λ → N π or Σ → N π decay). Also we canroughly identify the direction of hyperon emission fromthis DCA analysis.
†
∗1
∗2
∗3
∗4
∗5
∗6

84

Condensed from the article submitted to Phys. Lett. B;
Preprint nucl-ex/0310018
Department of Physics, Seoul National University, Korea
Department of Physics, Carnegie Mellon University, USA
Department of Physics, University of Tokyo
Department of Physics, Tokyo Institute of Technology
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
GSI, Germany

In the high-momentum region of the neutron spectrum, backgrounds predominantly originate from theK − two-nucleon absorption process (K − N N → Y N ;Y → N π). Simulation shows that neutron direction from the background process does not correlate
to that of hyperon emission, whereas the Σ from theK − ppn → ΣN N decay of the kaonic nucleus tends
to go backward to the formation neutron. Figure 1
shows the comparison of 4 He (stopped K − , n) spectra in coincidence with backward/forward Σ emission.
(Charged pions from the Λ tend to have a smaller momentum, thus we eliminated them by selecting a “fast”
charged pion.) The comparison of the two spectra reveals a peak at ∼470 MeV/c in the “backward” spectrum. The excess over the background is estimated tobe 3.6σ and is statistically signiﬁcant. Hence, we havefound evidence of strongly bound kaonic nuclei, whose
major decay mode is K − ppn → ΣN N . The binding
energy and width are obtained as BK = 165 ± 4 MeV
and Γ < 25 MeV, respectively.

Fig. 1. Neutron spectra from the 4 He(stopped K − , n) reaction in coincidence with backward/forward Σ emission.
Arrow indicates the K − ppn bound state.

References
1) M. Iwasaki et al.: Phys. Rev. Lett. 78, 3067 (1997).
2) Y. Akaishi and T. Yamazaki: Phys. Rev. C 65, 044005(2002).
3) A. Dote et al.: Prog. Thoer. Phys. Suppl. 146, 508(2003).
4) M. Iwasaki et al.: Nucl. Instrum. Methods Phys. Res.
A 473, 286 (2001).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Experimental signature of in-medium mass modification ofvector mesons at normal nuclear density
R. Muto, H. En’yo, M. Naruki,∗ F. Sakuma,∗ T. Tabaru and S. Yokkaichi, for the KEK-PS E325 Collaboration[QCD, chiral symmetry, normal nuclear density, mass modification, vector meson]
We measured invariant mass spectra of e+ e− pairs
produced in 12-GeV p+A interaction to investigate thein-medium mass modification of vector mesons. Modifications of mass spectra, even at normal nuclear density, have been predicted by many theories as a precursor of the QCD chiral phase transition.
The experiment was carried out at the KEK-PS
EP1-B beam line. The data gathering ended in March
2002. We already performed event reconstruction for
all of the obtained data with refined calibration parameters for drift chambers. We also performed event generation using cascade code JAM1) and detailed detector simulation using Geant 42) to analyze the obtainedmass spectra.3) In these analyses, we used approximately 130,000 cpu·hours of the excellent cpu power of
RIKEN CC-J,4) which is originally built for the RHIC
spin physics.
The invariant mass spectra of e+ e− pairs are shownin Fig. 1 for carbon and copper targets. The gray lines
are the best-fit results of cocktails of known hadronicsources with a combinatorial background. The significant excess can be seen on the low mass side of
the clear peak from decays of ω mesons in free space,which is located at 0.78 GeV/c2 . The obtained ρ/ωratios from the fit results are statistically consistent
with zero for both targets, which is much smaller than
the known ρ/ω ratio, unity, in p+p interactions in almost the same energy.5) This fact implies that most ofthe ρ mesons are modified to the lower mass region in
nuclear matter.
Next, we examined the velocity and nuclear size dependences of this excess. We divided the data into twogroups at βγ = 2.2 of the mesons. We fitted each spectrum in the same scheme and obtained the abundancesof ω and the excess. Here, the excess was integrated in
the mass region from 0.5 to 0.8 GeV/c2 . We also considered the mass acceptance of the spectrometer byMonte Carlo calculation. Figure 2 shows the velocity
dependence of the ratio of the excess to the ω for eachtarget. The excess increases in the lower velocity region and is larger in the heavier target (copper) data
than in the lighter target (carbon) data. These tendencies are geometrically and kinematically consistent
with a picture of meson-mass modification in a nucleus,
since slowly moving mesons in a larger nucleus have alarger probability of decaying inside a nucleus.
We are setting up a model calculation on the basisof a theoretical prediction to reproduce the observed
spectrum quantitatively.

Fig. 2. Velocity and target nucleus dependences of the ratioof the excess to the ω. The vertical axis is the ratio,
while thehorizontal axis is the average βγ value.

References

Fig. 1. Invariant mass spectra of the 2002 e+ e− data. a)is for the carbon target and b) is for the copper target.
∗

Department of Physics, Kyoto University

1) http://quark.phy.bnl.gov/~ynara/jam/2) http://wwwasd.web.cern.ch/wwwasd/geant4/
geant4.html
3) F. Sakuma et al.: RIKEN Accel. Prog. Rep. 37, 87(2004).
4) S. Yokkaichi et al.: RIKEN Accel. Prog. Rep. 37, 257(2004).
5) V. Brobel et al.: Phys. Lett. B 48, 73 (1974).

85

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RIKEN Accel. Prog. Rep. 37 (2004)

Nuclear mass number dependence of inclusive ω and φ meson
production in 12 GeV p-A collisions
T. Tabaru, H. En’yo, R. Muto, M. Naruki, F. Sakuma, and S. Yokkaichi, for the KEK-PS E325 Collaboration[Mass number dependence, Vector Meson]
It has been theoretically predicted that the vector
meson masses could be modified as a consequence ofthe partial restoration of the chiral symmetry at finite
density and/or finite temperature.1) We measured the
decays of ω → e+ e− , φ → e+ e− and φ → K + K − in
12 GeV p + A interactions. At the low-mass side of theω meson mass (0.55–0.75 GeV/c2 ) we have observed
the excess of e+ e− pairs in p-Cu collisions, which could
not be explained by the known hadronic sources.2)
Since the predicted mass modification depends on
nuclear matter density, it is important to understandhow the production and decay points are distributed
inside a nucleus. We therefore studied the production
mechanism of the ω and φ mesons, by measuring thenuclear mass number dependence (α) obtained by theusual parametrization, σ(A) = σ0 Aα , where σ(A) isthe cross section and A is the target mass number.
The experiment was performed using the EP1-B
beam line of the 12 GeV proton synchrotron of
the High Energy Accelerator Research Organisation(KEK). The 12 GeV proton beam was delivered ontopolyethylene (CH2 ), carbon (C) and copper (Cu) targets, and the produced e+ e− and K + K − pairs were
measured by the newly built spectrometer. The acceptances for φ → K + K − decays covered 0.5–1.5 in
the rapidity (y) and 0.4–1.6 GeV/c in the transverse
momentum (pT ), and those for decays of ω → e+ e−and φ → e+ e− covered 0.3–1.7 in y and 0–1.1 GeV/cin pT .
The kaon ID was performed with the time of flightmeasured by three types of plastic scintillation counters, the momentum measured by drift chambers,
and the hit association by aerogel Čerenkov counters,
whose refractive index was 1.034. The electron ID was
performed by cascade operation of gas Čerenkov counters using iso-butane with a refractive index of 1.0019
and electromagnetic lead-glass calorimeters. The purity of the final K + K − samples was 89.8 ± 2.4%, andthat of the final e+ e− samples was 79.5 ± 0.2%.
The measured invariant mass spectra consisted ofcorrelated pairs from resonance decays and uncorrelated pairs of combinatorial background. We evaluated the background by mixing events. The spectral
shapes of the correlated pairs and the spectrometer acceptance were estimated by feeding the result of the nuclear cascade simulation, JAM,3) into the detector simulation. By fitting these spectral shapes to the present
data, we obtained consistent results for the φ produc-86tion cross sections between the decays of φ → e+ e−and φ → K + K − , as shown in Fig. 1. We also obtained the ω production cross section of 1.4 ± 0.6 mb
in p-p collisions by subtracting the C target data fromthe CH2 data, which was consistent with the previous
measurement of 1.80 ± 0.25 mb for ρ0 meson.4) It is
known that the productions of ρ0 and ω have almost
the same cross sections in this energy region.4)
From the data of the C and the Cu targets, we obtained the α of 0.83 ± 0.07 for the ω production andthat of 1.1 ± 0.2 for the φ production measured in the
dielectron decay. In the decay of φ → K + K − , weobtained the α of 1.01 ± 0.08.
Although JAM overestimates these measured crosssections by factors of 8.93 for ω and 2.88 for φ, it reproduced the observed α, y and pT distributions of thesemesons fairly well. By examining the cascade processes
in JAM, the large α values in the present data can be
explained by the large contributions of the secondary
and tertiary interactions in a nucleus.

Fig. 1. Meson production cross sections as functions of target mass number.

References
1) T. Hatsuda and S. H. Lee: Phys. Rev. C 46, R34 (1992).
2) K. Ozawa et al.: Phys. Rev. Lett. 86, 5019 (2001).
3) Y. Nara et al.: Phys. Rev. C 61, 024901 (1999).
4) V. Blobel et al.: Phys. Lett. B 48, 73 (1974).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Geant4 simulation for the KEK-PS E325 spectrometer
F. Sakuma,∗ H. En’yo, M. Naruki,∗ R. Muto, T. Tabaru, and S. Yokkaichi, for KEK-PS E325 Collaboration[Geant4, vector meson, in-medium modiﬁcation]
We performed an experiment at the KEK proton
synchrotoron to measure the invariant mass spectraof ρ, ω and φ mesons through their e+ e− or K + K −decays in 12 GeV p + A interactions. The data acquisition was completed in March 2002, and we haveobserved in-medium modiﬁcation of the ρ and/or
ω mesons at normal nuclear-matter density for the ﬁrst
time.1,2)
To analyze the obtained mass spectra, we have toevaluate the mass shape from known hadronic sources.
The mass shape could be deformed by the detector acceptance and the energy loss eﬀects of electrons ﬂying through the spectrometer. To evaluate
such eﬀect, we performed detailed detector simulation using the Geant4 toolkit.3) For electrons andpositrons, Geant4 provides a realistic simulation ofionization losses, Coulomb multiple scattering andBremsstrahlung. The list of materials is summarizedin Table 1.4) All wires in the drift chambers are input
one at a time (total of 20,000 wires).

We generated vector mesons from the nuclear cascade code JAM.5) Vector mesons decayed to the e+ e−
or K + K − pair, and this pair is traced in the detector simulator. We obtained the simulated hit data
smeared with the measured chamber resolution, andanalyzed them using the source code used to analyze
read data. Figure 1 shows the e+ e− pair trajectoryfrom ω meson decay in the E325 spectrometer.
The invariant mass resolution of 6.1 ± 0.3 MeV/c2
is obtained in the ω → e+ e− decay from the detector
simulation. This result reproduces the real resolutionof approximately 7.4 ± 0.5 MeV/c2 . With this realistic simulation, we have conﬁrmed the observed excess,which is expected as a consequence of in-medium modiﬁcation and which, cannot be explained by any trivial
detector eﬀects. The observed excess is at least 40%of the ω-peak yield6) while the detector eﬀect is 10%
at most.
To expedite the analysis, we have used CC-J at
RIKEN. We would like to thank the members of the
Radiation Laboratory for their support.

Table 1. List of materials input to the simulation code.
Countermaterial

radius[mm]

thickness
X [mm]

rad length
X0 [mm]

X/X0[%]

Targettarget (C)target (Cu)x4
Ar-C2 H6 (50:50)
Wire-inner (Be-Cu)§
Wire-inner (Au-W)§
Wire-outer (Be-Cu)§
Wire-outer (Au-W)§
Mylar
air
scintillator
lappingair
Mylar
Ar-C2 H6 (50:50)
Wire (Be-Cu)§
Wire (Au-W)§
Mylar
air
Mylar
isobutane
acrylic mirror
aluminum cover
air
Mylar
Ar-C2 H6 (50:50)
Wire (Be-Cu)§
Wire (Au-W)§

–
–
0.00
–
–
–
–
245.00245.05380.00385.00385.20400.00400.05––880.00880.05899.95900.001560.00
1563.00
1564.00
1569.95
1570.00––

1.00
0.08x4245.000.018
0.00040.024
0.00060.05
134.95
5.00
0.20
14.80
0.05
479.950.031
0.0005
0.05
19.90
0.05
660.00
3.00
1.00
5.95
0.05
80.00
0.010
0.0001188.5
14.4
177608.0
15.8
3.5
15.8
3.5
287.4
305225.0
424.3
287.0
305225.0
287.4
177608.0
15.8
3.5
287.4
305225.0
287.4
181801.0
382.7
88.9
305225.0
287.4
177608.0
15.8
3.5

0.531
0.556x4
0.138
0.114
0.011
0.152
0.017
0.017
0.044
1.178
0.070
0.005
0.017
0.270
0.196
0.014
0.017
0.007
0.017
0.363
0.784
1.125
0.002
0.017
0.045
0.063
0.003

VTC

STC

CDC

FGC

BDC

§

X is average of wire thickness through the flight path of particles. However,in the simulation, all wires are input one at a time.

∗

Fig. 1. e+ e− pair trajectory from ω meson decay in E325
spectrometer.

References
1) K. Ozawa et al.: Phys. Rev. Lett. 86, 5019 (2001).
2) M. Naruki et al.: Nucl. Phys. A 721, 297 (2003).
3) http://geant4.web.cern.ch/geant4/4) M. Sekimoto et al.: Nucl. Instrum. Methods Phys. Res.
A 516, 390 (2004).
5) Y. Nara et al.: Phys. Rev. C 61, 024901 (1999).
http://quark.phy.bnl.gov/ynara/jam/
6) R. Muto et al.: RIKEN Accel. Prog. Rep. 37, 85 (2004).

Department of Physics, Kyoto University

87

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RIKEN Accel. Prog. Rep. 37 (2004)

Response of the HXD-II detector to cosmic heavy ionsM. Kawaharada,∗1 M. Kokubun,∗1 K. Makishima, S. Hong, Y. Terada, H. Miyasaka,∗2 K. Yamaoka,∗3
M. Ohno,∗4 Y. Fukazawa,∗4 H. Inoue,∗5 and T. Takahashi∗5[Iron ion, BGO, HXD-II]
The Hard X-ray Detector (HXD-II) is one of the instruments onboard the Astro-E 2 satellite, scheduled
for launch in February 2005. The HXD-II probes theuniverse in the energy range of 10–600 keV with a sensitivity an order of magnitude better than those of previous missions.1) The HXD-II consists of well-type 4×4
GSO(Gd2 SiO5 : Ce)/BGO(Bi4 Ge3 O12 ) phoswich counters called ‘Well-counter units’, each of which works
independently as an extremely low background hard
X-ray detector. The counters form an anticoincidence
system, and are further surrounded by 20 pillar-shaped
BGO counters called ‘Anti-counter units’.
In orbit, the HXD-II is exposed to various cosmic
rays. The dominant components of these rays are protons and helium ions of which the count rate is ∼ 100 Hz
per unit, and the energy deposit is ∼ 100 MeV. Although heavier ions are rare, ∼ 0.01 Hz, they could
deposit up to ∼ GeV via minimun ionization. The
HXD-II has been designed and developed by fully taking these large frequent signals into account.2,3)
On November 17–18 2002, we carried out a groundexperiment at the E3 beamline of the RIKEN ring
cyclotron as shown in Fig. 1. The objectives of theexperiment were 1) examining the precise shape andamount of the BGO scintilation activated by heavyions, 2) the eﬀect of secondary particles on a Wellcounter unit when heavy ions hit surrounding units,
and 3) conﬁrming the response of the Well-counter
unit and the ﬂight-compatible analog electronics toreal heavy ions. For these purposes, we acceralated
56
Fe ions to ∼ 90 MeV/nucleon, at a rate of 3–4 Hz sothat individual pulses could be examined. The ioniza-

Fig. 1. Experimental setup in the E3 beamline.
∗1
∗2
∗3
∗4
∗5

88

University of Tokyo
University of Delaware, USA
Aoyama Gakuin University
Hiroshima University
Japan Aerospace Exploration Agency (JAXA)

tion loss of these ions in BGO is ∼ 20 GeV/cm, anda total kinetic energy of 5 GeV is deposited in  1 cm.
Therefore, we can simulate the energy delivered byminimum-ionizing heavy nuclei in the orbit.
Firstly, we attached a BGO block (2 × 2 × 2 cm3 ) on
one end of an acrylic light guide (5 cm×20 cm×5 mm),which was glued to a ﬂight-compatible PMT to prevent it from being exposed to the ion beam. The
measured pulse heights of the 56 Fe events are 0.7 V
at a high voltage of −1000 V, and 1.9 V at −1200 V.
To investigate detailed structures in the pulses, we
magniﬁed and averaged the anode output at −1200 V.
Over a time range of 2.5–7.5 µs, no particular deviation from a smooth waveform, such as ringing, wasobserved. This implies that the BGO crystal itself behaves normally for heavy ions, just like for γ rays butwith a much larger output. Referring to calibration
isotopes, we determined that the BGO scintillation for
the 90 MeV/nulceon 56 Fe ion is eqivalent to ∼ 500 MeV
in terms of γ-ray response. In other words, the quenching factor is ∼ 0.1.
Secondly, we placed a Well-counter unit behind an
Anti-counter unit, and irradiated them with the 56 Fe
beam through a plastic scintillator used for triggers.
We set an oscilloscope so that it triggered on the coincidence between the plastic scintillator output and theleading edge of the Well-counter output. We actuallyobserved simultaneous events with various anode output pulse heights, ranging from 60 to 500 mV. These
events were scintillations of secondary particles createdin the Anti-counter unit. If we assume that they areprotons and their quenching factor is the same as thatof heavy ions, namely 0.1, their typical kinetic energy
is estimated as ∼ 60 MeV. Correcting this value forthe energy loss in the ∼ 4-cm-thick BGO of the Anticounter unit, we estimate their initial energy to be∼ 170 MeV. Therefore, each ion in the beam is inferred to produce a few tens secondary particles when
hitting an Anti-counter.
Finally, we irradiated the ion beam to the Wellcounter unit at the supplied voltage of 900 V. The
anode output was observed to clamp at 3 V, while theWell ampliﬁer output saturated at 4.3 V with an overshoot level of 2.4 V. These results conﬁrm the designed
responses of the Well-counter unit to large pulses.
References
1) T. Kamae et al.: Proc. SPIE 2806, 314 (1996).
2) T. Takahashi et al.: Proc. SPIE 3445, 155 (1998).
3) C. Tanihata et al.: Proc. SPIE 3765, 645 (1999).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Dimuon measurement in the NA60 experiment at CERN/SPS
H. Ohnishi, for the NA60 Collaboration[High-energy heavy-ion collisions, Quark Gluon Plasma]
The NA60 experiment1) measures the J/ψ suppression pattern in high-energy In-In collisions at CERN
Super Proton Synchrotron (SPS). Comparing the pattern measured in this new experiment to the patternmeasured in Pb-Pb collisions,2) we should be able todetermine the critical scale for the onset of deconfined parton condensation, and distinguish between
a parton percolation transition that should occur asa function of the number of nucleons participatingin the collision, and a thermal transition that should
depend on the reached local energy density. Moreover, NA60 is designed to measure muons arising frompositions displaced with respect to the primary collision vertex, thereby identifying open charm meson
decays and allowing the first clear measurement of theopen charm production cross section in heavy-ion collisions. The complementary analysis extracts a clean
sample of prompt intermediate mass dimuons, where
thermal dimuons can be searched.3) The NA60 experiment comprises a muon spectrometer and Zero degree calorimeter (ZDC) previously used in the NA50
experiment with a new detector, a silicon pixel vertex telescope, placed in the target region. The details
can be found elsewhere.1) The silicon pixel vertex telescope consists of eight 4-chip pixel planes followed by
4 large tracking stations, which are made from two
8-chip pixel planes. The readout chips were developed
for the ALICE and LHC-B experiments4) and are radiation tolerance up to 30 Mrad. Each pixel chip is
bump-bonded to a 300 µm thick silicon sensor whichcontains a matrix of 32 × 256 pixels of 50 × 425 µm2
size.
In June 2002, NA60 was first used to collect physics
data taking using a 400 GeV/c proton beam incident
on Be, In and Pb targets. The reconstructed dimuon
mass distribution after matching the muon from themuon spectrometer with the charged tracks in the vertex telescope is shown in Fig. 1. The mass resolution is found to be approximately 25 and 30 MeV forthe ω and φ peaks, respectively. Furthermore, as seenin Fig. 1, the acceptance for the low-mass dimuon
pairs is extended down to very low pT which allows
us to explore the window of low mass dileptons where
the CERES collaboration observed a strong anomalous excess of low-mass electron pairs.5) These results
confirmed the feasibility of the experiment and gavea good outlook for the subsequent runs with protonand Indium beams.
In the physics run in October 2003, we collected thefirst data of heavy-ion collisions induced by indium

Fig. 1. Left ﬁgure shows, dimuon mass distribution for
p-Pb collisions; Right ﬁgure shows pT distributions
measured in diﬀerent mass windows.

ions on 158 GeV/c per nucleon on indium targets. Figure 2 shows a typical In-In collision event reconstructedwith the NA60 vertex telescope. This figure illustrates
that the NA60 vertex telescope was operating well during the heavy-ion data collection period. The analysis of the data is in progress, to answer the question
whether quark gluon plasma formed in the matter created by heavy-ion collisions at CERN SPS.

Fig. 2. Tracking of charged particles produced in one
Indium-Indium collision and traversing the silicon pixel
telescope.

References
1) NA60 Collaboration: CERN/SPSC 2000-010, March
2000.
2) M. C. Abreu et al.: Phys. Lett. B 447, 28 (2000).
3) R. Rapp and E. Shuryak: Phys. Lett. B 473, 13 (2000).
4) W. Snoeys et al.: Nucl. Instrum. Methods Phys. Res. A
465, 176 (2001); K. Wyllie et al.: Proc. 5th Workshop
on Electronics for LHC Experiments, Snowmass, USA,1999-9 (CERN, 1999), p. 93.
5) G. Agakishiev et al.: Phys. Lett. B 422, 405 (1998).

89

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RIKEN Accel. Prog. Rep. 37 (2004)

First measurement of muon transfer reactions with argon ions
implanted in solid deuterium films
P. Strasser, K. Nagamine,∗ T. Matsuzaki, K. Ishida, Y. Matsuda, K. Itahashi, and M. Iwasaki[Muonic atom spectroscopy, Solid hydrogen ﬁlm, Ion implantation]
Muonic atom spectroscopy1) has for many years
played an important role in establishing and reﬁning
nuclear structure models, and has been successfully
used to study stable nuclei. Muonic X-ray measurements can yield very precise and absolute values forthe charge radii and other ground-state properties. We
proposed the cold (solid) hydrogen ﬁlm method2) toextend muonic atom spectroscopy to the use of nuclear
beams, including in the future RI beams, and to produce radioactive muonic atoms. This method would
allow studies of unstable nuclei by means of the muonic
X-ray method at facilities where both intense µ− andRI beams would be available. The basic concept is tostop both beams simultaneously in a solid hydrogen(H2 /D2 ) ﬁlm, followed by the direct muon transfer reaction to higher Z nuclei to form radioactive muonicatoms. An experimental program has been initiatedat the RIKEN-RAL muon facility to experimentally
establish the feasibility of this method.3) An experimental setup (µA∗ ) was constructed to implant stableions in solid hydrogen ﬁlms.4) The ﬁrst results withimplanted argon ions have recently been obtained.
Two diﬀerent target conﬁgurations were investigated. At ﬁrst, a two-layer arrangement was used. The
primary layer made of 0.5-mm H2 /D2 is used to eﬃciently stop 27 MeV/c µ− followed by pµ formation,pµ to dµ transfer and dµ emission with the help of theRamsauer-Townsend eﬀect in the diﬀusion of the dµ
atoms, while the second layer made of pure D2 (severalµm thick) with implanted Ar ions is used to conﬁne theproduction region of muonic argon (µAr) atoms to an
optimized ﬁlm thickness. This scheme would requirea smaller amount of implanted ions. The germanium
energy spectra shown in Fig. 1 (a) very clearly indicates µAr 2p → 1s transition X-rays at 644 keV fromthe muon transfer reaction. Approximately 1016 Ar
ions per cm2 were implanted in a D2 thickness of 5 µm
using alternate implantation and D2 deposition, whichcorresponded to an average concentration of 500 ppm.
At this concentration, all dµ atoms emitted from theprimary H2 /D2 layer are expected to transfer very
rapidly. Only “short” delayed events are observed,
mainly due to the diﬀusion time of the dµ atoms before reaching the added D2 layer. The triangular peaks
observed at 596 keV and 691 keV result from inelastic
neutron excitation of the Ge isotope nuclei within thedetector itself.5) The neutrons are produced followingµ− capture on nuclei.
Later, a pure D2 layer was used, and each Ar implantation was separated from the next by depositing
about 20 µm of D2 to make a total D2 layer thicknessof 0.5 mm. Each implantation region had a thicknessof only 0.1 µm with a local concentration of 1000 ppm.
The average Ar concentration throughout the D2 layer
was around 5 ppm, corresponding to approximately thesame amount as used in the previous target. Figure 1 (b) clearly shows that even with an inhomogeneous target, very strong muon transfer events can bedetected. Due to the strong reduction of the Bragg
cross section at low dµ collision energies in solid D2 ,6)
the dµ atom mean free path is strongly increased tonearly 10–20 µm below ∼ 1 meV, resulting in a high dµ
atom mobility and a very long diﬀusion length. Preliminary analysis shows that the 644 keV X-ray disappearance rate is consistent with an average Ar concentration of 5 ppm. At this concentration, most of themuon transfer is delayed, and the S/N ratio can begreatly improved by selecting only delayed events.
This ﬁrst test experiment was performed with a large
amount of implanted Ar ions. Further measurements
are planned with reduced Ar concentrations to study
the muon transfer reaction and investigate the diﬀusion process of dµ atoms in solid. This eﬀect will limit
the minimum layer thickness that can be used in the
two-layer arrangement without being aﬀected by dµ
atom loss.
References

Fig. 1. Total energy spectra measured with (a) 0.5-mm
H2 /D2 ⊕ 7-µm D2 (Ar), and (b) 0.5-mm D2 (Ar).
∗90

Meson Science Laboratory, High Energy Accelerator Research Organization (KEK)

1) L. Schaller: Z. Phys. C 56, S48 (1992).
2) P. Strasser et al.: Hyperfine Interact. 119, 317 (1999).
3) P. Strasser et al.: Nucl. Phys. A 722, 523c (2003).
4) P. Strasser et al.: Nucl. Instrum. Methods Phys. Res. A
460, 451 (2001).
5) E. Gete et al.: Nucl. Instrum. Methods Phys. Res. A
388, 212 (1997).
6) A. Adamczak: Hyperfine Interact. 119, 23 (1999).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of the magnetic ﬁeld eﬀect in muon catalyzed fusion
K. Ishida, T. Matsuzaki, M. Iwasaki, Y. Matsuda, K. Nagamine,∗1 N. Kawamura,∗1 H. Imao,∗2
M. Kato,∗3 H. Sugai,∗3 M. Tanase,∗3 and G. H. Eaton∗4[Muon catalyzed fusion]
Muon catalyzed fusion (µCF) has been studied under a variety of D/T target conditions since the startof the RIKEN-RAL µCF experiment in 1995. One of
the main interests in the study of µCF is the improvement of energy production eﬃciency, which can beachieved by larger λc (cycling rate of µCF process) andsmaller W (muon loss per cycle). However, there aresome experimental conditions whose eﬀect on µCF has
not been studied suﬃciently, and the magnetic ﬁeld is
one of them. While µCF experiments at PSI, LAMPF
and Dubna were mostly carried out without a magnetic
ﬁeld, µCF experiments at RIKEN-RAL were all carried out under a strong magnetic ﬁeld of 2.4 T only, because this is the ﬁeld where the muon beam is best focussed to the D/T target which has a size of only 1 cm3 .
Theoretically, it is not common to presume that themagnetic ﬁeld would aﬀect the reactions of muonicatoms, since the magnetic ﬁeld eﬀect on the energy
level is very small compared with the energy scale ofthe muonic atoms. However, there were several theoretical investigations predicting the possible magnetic
ﬁeld eﬀect on the muon-to-alpha sticking, which is themain source of muon loss in µCF.
Melezhik and Schmelcher proposed1) that a magnetic ﬁeld would stimulate transitions between the lm
sublevels of a moving (αµ)+ ion formed by muon-toalpha sticking. The ﬁeld-stimulated transitions cancompete with other processes such as muon strippingfrom the (αµ)+ ion and may change the eﬀective sticking probability. Another calculation indicates the magnetic ﬁeld eﬀect on the muon-to-alpha sticking throughthe contribution of convoy muons.2) There can be,although with a small probability (∼ 0.5%), a convoy muon produced after fusion, which moves slightly
ahead of the alpha particle but is not initially captured.
The alpha particles may ﬁnally catch up with some of
the convoy muons and result in sticking. A magnetic
ﬁeld reduces the probability of recombination of muon
and alpha particles by separating the tracks of oppositely charged particles. Thus it is important to study
experimentally whether there is any indication of themagnetic ﬁeld eﬀect to test these predictions.
The experiment was performed under four magnetic
∗1

∗2
∗3
∗4

Meson Science Laboratory, Institute of Materials Structure
Science, High Energy Accelerator Research Organization(KEK)
Department of Physics, University of Tokyo
Tokai Research Establishment, Japan Atomic Energy Research Institute
Rutherford Appleton Laboratory, UK

ﬁelds (0, 1.2, 2.4 and 3.3 T) for liquid D/T with a tritium concentration of 30%. Fusion neutrons and various
muonic X-rays were detected while the number of stopping muons were determined by counting the muondecay electrons. The result is summarized in Fig. 1.
As expected, the muon stopping rate was significantly reduced at 0 and 1.2 T compared with thatat 2.4 T. Even with this large diﬀerence in measurement conditions, the cycling rate and the muon loss
probability, which is mainly due to the muon-to-alphasticking, were almost independent of the ﬁeld within±5% for the liquid D/T. Kα X-ray yield slightly increased with magnetic ﬁeld by 30% (2.5 σ). The resultis opposite to that predicted based on convoy eﬀect,2)of decerasing muon-to-alpha sticking and X-ray yieldas magnetic ﬁeld is increased. On the other hand,the stimulated transition1) enhances 2s-2p mixing in(αµ)+ and increases the Kα emission and thus it isconsistent with, or at least does not contradict, ourresult. In order to further conﬁrm the magnetic ﬁeld
eﬀect on µCF and its dependence on the target condition, measurement of the magnetic ﬁeld eﬀect in solid
D/T is in progress.

Fig. 1. Preliminary result on field dependence of the number of muons stopped in liquid D/T target, µCF cycling
rate (λc ), muon loss per cycle (W ), and the amount ofαµ Kα X-ray per fusion.

References
1) V. S. Melezhik and P. Schmelcher: Phys. Rev. A 59,
4264 (1999).
2) B. Muller, H. E. Rafelski, and J. Rafelski: Phys. Rev.
A 40, 2839 (1989).

91

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RIKEN Accel. Prog. Rep. 37 (2004)

SF6 dielectric molecules: Electron and positron scattering dynamic
properties and possible applications
C. Makochekanwa∗ and M. Kimura
SF6 , sulfur hexaﬂuoride, is a man-made gas, andis presently one of the most widely and extensively
used gases for commercial and research applications.1)
Therefore, its various physical and chemical properties, and dynamical behavior under various application conditions have been broadly studied. However,
it is also now known as one of the most serious greenhouse gases since it is an eﬃcient absorber of infrared
radiation at wavelengths near 10.5 µm, and is solidly
stable in chemical and photolytic reactions and hence,remains permanently once released in air. Hence, concerns over its environmental impact have newly generated interest for performing a more comprehensive
study of this gas. Accordingly, we have undertaken acomparative study of electron and positron scatteringfrom this molecule from 0.6 eV to 1000 eV. By investigating electron and positron scattering comparatively,
more detailed underlying physics of spectroscopic anddynamical aspects is expected to emerge and also critical evaluation of electron scattering cross-section data
becomes possible.
Earlier studies on dynamical aspects of this molecule
include, total cross-section measurements by electron
and positron impact by Dabaneh et al.,2) and swarm
experiments by Christophorou et al.1) Phelps and Van
Brunt have compiled all available data of electron impact, and published a complete set of cross-section
data for a wide range of energy from 1 meV to 1 keV.3)

Although agreement between the present results andearlier ones reported by Dabaneh et al. on both electron and positron scattering cross sections for SF6 isfound to be good, this study covers more extended impact energies, compared to those of Ref. 2.
Total cross-section measurements for 0.4–1000 eV byelectron and 0.2–1000 eV by positron impacts were performed using an absorption type time-of-ﬂight apparatus as in our previous works.4) The present results for
total cross sections (TCSs) and elastic cross sections(ECSs) are shown for electron and positron impact in
Fig. 1 (a) and (b), respectively. The result of elastic
cross section was obtained theoretically by using thecontinuum multiple-scattering (CMS) method.5)
References
1) L. G. Christophorou, J. K. Olthoﬀ, and D. S. Green:
National Institute of Standards and Technology (NIST)Technical Note 1425, 1 (1997).
2) M. S. Dabaneh, Y.-F. Hsieh, W. E. Kauppila, C. K.
Kwan, S. J. Smith, T. S. Stein, and M. N. Uddin: Phys.
Rev. A 38, 1207 (1988).
3) A. V. Phelps and R. J. Van Brunt: J. Appl. Phys. 64,
4269 (1988).
4) O. Sueoka, S. Mori, and A. Hamada: J. Phys. B 27,1453 (1994).
5) M. Kimura and H. Sato: Comments At. Mol. Phys. 26,
333 (1991).

Fig. 1. SF6 total cross sections for (a) electron and (b) positron scattering.

∗

Graduate School of Science and Engineering, Yamaguchi
University

93

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RIKEN Accel. Prog. Rep. 37 (2004)

H+ + CH2 collisions below the 1.5 keV regime
H. Suno,∗1 M. Kimura,∗1 R. J. Buenker,∗2 A. Watanabe,∗3 and I. Shimamura
Electron capture in collisions of ions with atoms in
the low-keV-energy regions is one of the most important processes in experimental and theoretical atomic
physics as well as in applications to astrophysics andfusion research. Relatively comprehensive studies havebeen carried out for a variety of atomic targets andvarious charged projectiles in a wide range of collisionenergies (meV to keV), but those for molecular targets
are still scarce, both experimentally and theoretically.
This report concerns a rigorous theoretical investigation of the electron capture process in the collisionof H+ ions with CH2 molecules in the region below
a few keV. This hydrocarbon molecule, CH2 , exist in
various atmospheric and astrophysical environments.
It also plays a key role in various molecular reactions
involving carbon atoms in the universe. We consider
four diﬀerent scattering conditions for collision dynamics: (i) the proton approaches the C atom along the bisector of the H-C-H bond angle, passing the midpointof the H-H line; (ii) it travels along the same line asin (i), but in the opposite direction; (iii) the proton
approaches the C atom in the H-C-H plane and perpendicularly to the bisector of the H-C-H bond angle;(iv) the proton approaches the C atom perpendicularly
to the H-C-H plane.
The adiabatic potential-energy curves are calculatedby the multireference single- and double-excitation
conﬁguration-interaction (MRD-CI) method,1,2) with
conﬁguration selection and energy extrapolation employing the Table-CI algorithm.3) The ab initio calculations are performed for each of the four conﬁgurations mentioned above. Scattering dynamics is studied on the basis of the fully quantum formulation ofa molecular-orbital expansion method. The total scattering wave function is described in an adiabatic representation as an expansion in products of electronic
and nuclear wave functions and the electron translation factor. Substitution of the total scattering wave
function into the stationary Schrödinger equation andtransformation to the diabatic representation4) yield
the coupled equations


1
d
I
−
V
(R)
+
EI
X d (R) = 0,
(1)
R
2µ
where k = (2µE)1/2 is the momentum of the projectile, µ the reduced mass of the system, I the identity
matrix, V d the diabatic potential-energy matrix, andX d (R) the nuclear wave function in the diabatic representation. The coupled equations (1) are solved nu∗1
∗2
∗3

94

Faculty of Engineering, Yamaguchi University
Theoretische Chemie, Bergische Universität-Gesamthoscschule Wuppertal, Germany
Faculty of Science, Ochanomizu University

merically to obtain the scattering S l matrix for eachpartial wave l.5) The diﬀerential cross section is thengiven by

2
dσ(θ)
1 
l
= 2
(2l + 1){δif − Sif }Pl (cos θ) , (2)dΩ
4klwhere θ is the scattering angle in the center of mass
coordinates.
The diﬀerential cross sections for electron capture
are shown in Fig. 1 for all four molecular conﬁgurations(i)–(iv), for scattering angles of 0◦ –180◦ at 1.5 keV. For
all cases, the diﬀerential cross sections oscillate rapidly
when θ ≤ 5◦ , while they are all relatively smooth when5◦ ≤ θ ≤ 25◦ . We noted that the magnitude of thediﬀerential cross section for case (i) is nearly the sameas that for case (ii) in the region θ ≤ 30◦ . For all cases,
oscillatory structures are present when θ ≥ 30◦ .
In conclusion, the dependences on the molecularorientation—The steric eﬀects—are conspicuous in
H+ + CH2 collisions.

Fig. 1. Diﬀerential cross sections for electron capture forthe four molecular conﬁgurations (described in the text)
at 1.5 keV.

References
1) R. J. Buenker and S. D. Peyrimhoﬀ: Theor. Chim. Acta35, 33 (1974).
2) R. J. Buenker: Int. J. Quantum Chem. 29, 435 (1986).
3) R. J. Buenker: Proc. Workshop on Quantum Chemistry
and Molecular Physics, Wollongong, Australia, editedby P. Burton (University Press, Wollongong, 1980).
4) M. Kimura and N. F. Lane: Adv. At. Mol. Opt. Phys.
26, 79 (1989).
5) B. H. Bransden: Atomic Collision Theory (Benjamin,
New York, 1983).

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RIKEN Accel. Prog. Rep. 37 (2004)

Resonant coherent excitation of 2s electron of Li-like Fe and Ni ions
T. Ikeda, Y. Nakai, Y. Kanai, T. Kambara, N. Fukunishi, T. Azuma,∗1 K. Komaki,∗2
C. Kondo,∗2 and Y. Yamazaki
When the energy diﬀerence between two levels of
ion channeling through a crystal agrees with the energy of a “virtual-photon” of the periodic crystal ﬁeld,
the ion is resonantly excited. This is referred to as
the “resonant coherent excitation (RCE)”. In the caseof ion channeling in the (22̄0) plane of a Si crystal,
the transition energy, √Etrans , is given by the equations
k cos θ/a + l sin θ/(a/ 2) = Etrans /hcγβ in the casethat θ is the angle between√ the incident beam and the[001] axis and k cos θ/(a/ 2)+l sin θ/a = Etrans /hcγβ
in the case that θ is the angle between the incident
beam and the [110] axis. Here, k and l are integers, a 
is the lattice constant, cβ is the ion velocity,
γ = 1/ 1 − β 2 , and h is the Planck constant. Many
RCE experiments have been performed but no RCE experiments on the outer-shell electrons of systems withthree or more electrons have been reported to the bestof our knowledge. Azuma and coworkers have foundthat resonances are quite sharp in a series of RCE experiments using the planar-channeling of relativistic
H-like and He-like heavy ions.1–4) Therefore, we can
expect a sharp resonance structure also for the RCEof a 2s electron of Li-like heavy ions.
We measured the 2s electron RCE at the n = 3 statesof 83 MeV/u Fe23+ and 72 MeV/u Ni25+ ions. The
experimental setup was described in other reports.5,6)
A 7-µm-thick Si (001) crystal was vertically mounted
so that the beam direction was near the [001] axis for
Fe23+ and this crystal foil was 45◦ inclined so that thebeam direction was near the [110] axis for Ni25+ . The
ions emerging from the crystal were deﬂected by ananalyzing magnet downstream of the Si target in order
to separate the ﬁnal charge states. A two-dimensional
position-sensitive detector (2D-PSD) was located 8 m
downstream of the analyzing magnet, which detected
Li-like, He-like, H-like and bare ions.
Electrons in the excited state are much more easily stripped in the crystal target than those in the
ground state. Therefore, the fraction of surviving Lilike ions, f (Li-like) = N (Li-like)/[N (Li-like)+N (Helike)+N (H-like)+N (bare)], should decrease when theLi-like ions are resonantly excited, where N is the number of Li-like, He-like, H-like and bare ions emerging
from the crystal. The survival fraction f (Li-like) was
measured as a function of rotation angle θ. Figure 1
shows f (Li-like) for Ni25+ under the resonance condition of (k, l) = (1, 1), where θ is the angle from the [110]axis. Five resonance dips can be observed. For Fe23+ ,a similar resonance dip structure was also obtained.
∗1∗2

Fig. 1. Survival fraction f (Li-like) for 72 MeV/u Ni25+ under the resonance condition of (k, l) = (1, 1). Opencircles and solid circles correspond to diﬀerent experimental runs.

By comparing the transition energy of each dip with
spectroscopic data, we assigned dip A to the transition from 2s1/2 to 3s1/2 , dip B from 2s1/2 to 3p1/2 , dip
C from 2s1/2 to 3p3/2 , dip D from 2s1/2 to 3d3/2 anddip E from 2s1/2 to 3d5/2 . Surprisingly, the resonancedips corresponding to optically forbidden transitions(dip-A, dip-D and dip-E) can be observed as well as
optically allowed transitions (dip-B and dip-C). Here,an optically allowed transition denotes the E1 transition and an optically forbidden transition is any othertransition. We are considering two possible reasons forthe observation of the optically forbidden transitions:(1) The transitions from the 2s state to the 3s and 3d
states become less and less optically forbidden as the
distance from the channel center increases, due to E1
transition via the 3p component in the Stark-mixed 3s
and 3d states. (2) In the crystal periodic ﬁeld, transitions with a large momentum transfer become more
important. It is thought that transitions with a large
momentum transfer occur far from the channel center. Therefore purely optically forbidden transitions
become more important with increasing distance fromthe channel center.
References
1) T. Azuma et al.: Phys. Rev. Lett. 83, 528 (1999).
2) T. Azuma: Phys. Scr. T 80, 79 (1999).
3) T. Azuma et al.: Phys. Scr. T 92, 61 (2001).
4) K. Komaki et al.: Nucl. Instrum. Methods Phys. Res.
B 146, 19 (1998).
5) Y. Nakai et al.: RIKEN Accel. Prog. Rep. 36, 96 (2003).
6) Y. Nakai et al.: Nucl. Instrum. Methods Phys. Res. B
205, 784 (2003).

Department of Physics, Tokyo Metropolitan University
Institute of Physics, University of Tokyo

95

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RIKEN Accel. Prog. Rep. 37 (2004)

Elastic wave from fast Xe-ion irradiation on solids
T. Kambara, Y. Kanai, T. M. Kojima, Y. Nakai, Y. Yamazaki, A. Yoneda, and K. Kageyama∗
When a fast heavy ion passes through a solid, it deposits its kinetic energy through electronic excitations
which may result in temporary or permanent atomic
displacements in the lattice. Such atomic displacements, besides thermal expansion, can generate stressand strain along the ion path inside the bulk. On theother hand, the ion irradiation might result in the ejection of atoms or molecules from the surface to vacuum,
and the recoil of the ejection stresses the surface. In
either case, the stress and strain generated by the irradiation propagate in the bulk as elastic waves, which
can be detected by ultrasonic sensors at a distance ofmore than 30 mm. The source of the stress can be located by precise measurements of the propagation timeof the elastic waves.
We have performed such seismological analyses ofirradiation eﬀects by fast heavy ions on solids at the
RIKEN Ring Cyclotron. Solid targets were irradiated with single-bunch heavy-ion beams, and waveforms from piezoelectric ultrasonic sensors were observed with an oscilloscope. Results with a 3.8 GeV
Ar beam on various solids have been reported previously,1) where the depth of the elastic wave correlatedwith the range of the ions in the material calculatedwith the TRIM code.2)
Here, we report another experiment to locate thesource of the elastic waves generated by 3.54 GeV
136
Xe ions. The experiment setup is almost the sameas that described previously: A 10-mm-thick plate ofsample material is irradiated by a single-bunch ion
beam and the generated elastic waves are detected
at the back of the plate. The present experiment requires more precision in the source-position measurement since the range of the Xe ion (approximately
0.3 mm) is much shorter than that of the Ar ion (approximately 4.2 mm). Since the uncertainty of the
propagation-time measurement is mainly due to thesignal delay of about 80 ns caused by the piezoelectric
sensors and ampliﬁers, we have performed complementary measurements with a pulse YAG laser to cancel
the delay. Since the laser is absorbed in metal within
1 µm from the surface, the laser-generated waves travel
across the sample from surface to surface. If the ion irradiation generates elastic waves inside the sample, thewaves travel in the sample to the sensor by a shorter
distance, as shown in Fig. 1. The diﬀerence in elasticwave arrival time between the ion and laser irradiations
corresponds to the depth of the ion-generated waves.
Before and after the ion irradiation on an Al sample,
we irradiate the sample using a laser with an energyof 0.3–0.5 mJ/pulse. The acquisition of the waveform∗

96

Department of Mechanical Engineering, Saitama University

Fig. 1. Schematics of beam and sensor setups for laser (left)
and ion (right) irradiations.

is triggered by the reﬂected light signals from a photodiode. In both ion and laser measurements, the setupof the sensors and the ampliﬁers are unaltered. Figure 2 shows the onset of the longitudinal waveforms by
the Xe-ion (upper) and YAG laser (lower) irradiations.
The origin of the time axis is set to the impingementwith corrections for the diﬀerences in cable length andﬂight time of the ions. The waveform by the ion beam
is normalized to 104 ions per bunch.
The onset of the ion-generated elastic wave is aheadof that of the laser-generated wave by about 45 ± 5 ns.
Since the velocity of the longitudinal wave in thissample has been determined to be 6514 m/s, this
delay time corresponds to a source depth of about
293 ± 32 µm. It is in good agreement with the range ofthe Xe ions of 288 µm calculated with the TRIM code.
The shape of the elastic wave onset pulse is diﬀerent
between the ion and laser irradiations: It is broader for
the ion than the laser irradiation. The precision of thedelay time is limited by the slow increase in the elastic
wave by the ion irradiation. In the ion irradiation, thesource region of the elastic wave should spread overthe ion range, and the analyses of the waveform could
reveal the distribution of the radiation-induced stress.

Fig. 2. Elastic waveforms at the onset of the longitudinal wave by 3.54-GeV Xe ions (upper) and YAG laser(lower).

References
1) T. Kambara et al.: Nucl. Instrum. Methods Phys. Res.
B 193, 371 (2002).
2) J. F. Ziegler, J. P. Biersack, and U. Littmark: The Stopping and Range of Ions in Solids (Pergamon Press, New
York, 1985).

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RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀect of GeV-ion irradiation on Fe-Ni invar alloys
F. Ono,∗1 A. Iwase,∗2 S. Komatsu,∗1 H. Kanamitsu,∗1 Y. Chimi,∗3 N. Ishikawa,∗3 and T. Kambara
Fe-Ni alloys with a Ni-concentration approximately
35 at% are called invar alloys that are known to exhibit various anomalies in both mechanical and magnetic properties.1) These anomalies are as follows:
very small thermal expansion coeﬃcient, anomalous
decrease in the spontaneous magnetization from the
Slater-Pauling curve, and very large pressure dependence of the Curie temperature TC . These anomalies
are associated with the instability of the ferromagnetic
condition of the 3d-electrons.2) The Curie temperatures of Fe-Ni invar alloys were reported to decrease3)
with pressure at a high rate of −36 K/GPa. Therefore,high-energy ion irradiation is expected to introduce alarge positive change in TC through the negative pressure associated with the irradiation-induced lattice expansion.
The eﬀect of high-energy ion beam irradiation on
TC of Fe-31.9 at%Ni invar alloy was investigated andreported to increase with irradiation dose.4,5) In thesereports, unfortunately, the data before irradiation are
missing. Therefore, it was not possible to check
whether the dose-dependence of TC is linear. In thisreport, we present a full curve of the dose-dependenceof TC .
Thin rectangular plates of Fe-30at%Ni Invar alloy were prepared. The irradiations were carriedout at room temperature with 3.8 GeV Ta ions to
the ion-ﬂuence of the order of 1013 /cm2 using the
RIKEN Ring Cyclotron. Observed ac-susceptibilitytemperature curves before and after the irradiations

are shown in Fig. 1. The ac susceptibility decreases
suddenly at the Curie temperature. In this ﬁgure it isevident that TC increases with irradiation dose. The
dose dependence of TC is shown in Fig. 2, where asublinear relationship is clearly seen.
This sublinear eﬀect indicates that there are at least
2 or more origins6,7) that contribute to the increasein TC . A possible mechanism is the lattice expansion
associated with the introduction of pointlike defects
and tracks along the paths of ion beams. Because thepressure dependence of TC in Fe-Ni Invar alloys is large
and negative, TC increases with the negative pressure.
Another mechanism is compositional changes inducedby irradiation.

Fig. 2. Change in Curie temperature with irradiation dosein Fe-30 at%Ni invar alloy.

References

Fig. 1. Temperature dependence of ac susceptibilities for
Fe-30 at%Ni invar alloys before and after irradiation with 3.8 GeV Ta ions to a dose of up to 1.5 ×
1013 ions/cm2 .
∗1
∗2
∗3

Department of Physics, Okayama University
Research Institute for Advanced Science and Technology,
Osaka Prefecture University
Japan Atomic Energy Research Institute1) For example, see: The Invar Eﬀect: A Centennial Symposium, edited by J. Wittenauer (The Minerals, Metals& Materials Society, Warrendale, 1997).
2) P. Entel, E. Hoﬀmann, P. Mohn, K. Schwarz, and V. L.
Moruzzi: Phys. Rev. B 47, 8706 (1993).
3) S. Endo, M. Nishino, and F. Ono: Sci. Technol. High
Pressure 2, 850 (2000).
4) F. Ono, A. Iwase, Y. Hamatani, Y. Motoshimizu, N.
Ishikawa, Y. Chimi, Y. Mukumoto, and T. Kambara:
RIKEN Accel. Prog. Rep. 35, 96 (2002).
5) A. Iwase, Y. Hamatani, Y. Mukumoto, N. Ishikawa, Y.
Chimi, T. Kambara, C. Mueller, R. Neumann, and F.
Ono: RIKEN Accel. Prog. Rep. 36, 99 (2003).
6) F. Ono, Y. Hamatani, Y. Mukumoto, S. Komatsu, N.
Ishikawa, Y. Chimi, A. Iwase, T. Kambara, C. Mueller,
and R. Neumann: Nucl. Instrum. Methods Phys. Res.
B 206, 295 (2003).
7) A. Iwase, Y. Hamatani, Y. Mukumoto, N. Ishikawa, Y.
Chimi, T. Kambara, C. Mueller, R. Neumann, and F.
Ono: Nucl. Instrum. Methods Phys. Res. B 209, 323(2003).

97

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RIKEN Accel. Prog. Rep. 37 (2004)

Evaluation of single-event eﬀect in power MOSFET
N. Ikeda,∗1 S. Kuboyama,∗1 K. Oka,∗1 H. Sato,∗1 H. Ohira,∗2 Y. Morishima,∗2
H. Otomo,∗2 O. Shimada,∗2 N. Inabe, and M. Kase
A power MOSFET (metal-oxide-semiconductor ﬁeldeﬀect transistor) is a key device in a power circuit
which achieves low ON-resistance and fast switching.
A MOSFET to be used in space is required to have radiation hardness. Protons, heavy ions and other particles in space could cause single-event eﬀects and leadto semiconductor device malfunction or failure. Singleevent burnout (SEB) is the main concern regarding
power MOSFETs. SEB is triggered by a heavy ion
passing through the device when it is oﬀ. Transientcurrent by such an ion turn on a parasitic bipolartransistor, which results in burning out of the device
and its possible destruction.1) JAXA has developed
a radiation-hardened power MOSFET for use in space.
It has SEB tolerance up to the rated voltage (drainsource voltage, VDS ). Several parameters for hardness
were determined, and their performances were veriﬁedby 58 Ni19+ irradiation tests using the RIKEN Ring Cyclotron. Energy, LET and the range of ions in a device
were 300 MeV, 26 MeV/(mg/cm2 ), and 50 µm, respectively.
The EPICS (Energetic Particle Induced Charge
Spectroscopy) system developed by JAXA, was introduced to observe SEB. It collects charges of holes andelectrons generated by the penetration of an ion. SEB
resistance is judged on the basis of the spectra of thosecollected charges with VGS (gate-source voltage) equal
to zero and several VDS values. Typically, two peaks
are observed in the spectra, which are here called the
1st peak and the 2nd peak. They have diﬀerent mechanisms of charge collection. The 2nd peak grows (shifts
to the right) with the increase of VDS and becomes
the SEB peak which has a much larger collection of
charges. Therefore, the performance of the 2nd peakis a good index of SEB resistance, and it is better tohave a 2nd peak with smaller charges.
The upper graph in Fig. 12) shows the spectrumof a MOSFET whose epi-layer parameters (resistivity
and thickness) of have been improved. The collectedcharges of the 2nd peak are less than those of a reference MOSFET (lower graph). No SEB was observed
up to the rated VDS .
Figure 22) shows the spectrum diﬀerence of otherparameter, which is the length of an n-layer protruding out from the p-layer under the gate. SEB was
observed in the longest of the three devices. The twoother devices exhibit almost the same spectrum. The
SEB threshold was determined from this result.

∗1
∗2

98

Japan Aerospace Exploration Agency
Ryoei Technica Company

Fig. 1. SEB spectra of the 150 V power MOSFET withimproved epi-layers (upper). Collected charges of 2nd
peak are smaller than those of reference (VDS = 135 V).

Fig. 2. SEB spectra of 250 V power MOSFETs with otherparameter, which is the length of an n-layer protruding
out from the p-layer under the gate. SEB occurred in
the longest device (VDS = 220 V).

There are some other parameters for SEB, and theireﬀectiveness for SEB tolerance was proved by the irradiation experiment at RIKEN.
References
1) JAERI and NASDA Joint Research Report, Vol. 2(1999), p. II-9.
2) N. Ikeda et al.: IEICE Technical Report, EE2003-40(2003) p. 43.

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RIKEN Accel. Prog. Rep. 37 (2004)

Collective luminescence of extremely dense electron-hole pairs
created in ion tracks in insulators
K. Kimura,∗1 M. Koshimizu,∗1 K. Asai,∗2 and M. Kase
We have found ultrafast luminescence (r < 100 ps)
from incipient heavy-ion track cores in insulator crystals such as alkali halides, metal oxides, and alkalineearth halides.1) This luminescence is the ﬁrst observed
collective behavior of track cores of ions, and precedesthat due to known excitons or excited states of impurity or defect centers. Such luminescence can bedetected using not only fast sensitive detection techniques but also the beam condition under which energetic electrons to eject further secondary electrons
are negligibly small and moreover the track-core eﬀects
are major. We have developed techniques for luminescence measurements with a time resolution of 85 ps.1)
To make the core eﬀect prominent and to equalize theincident ion velocity, the equal incident ion energy of2 MeV/nucleon was used so that we could compare thedependence on excitation density in the track coresreasonably for diﬀerent ions, and moreover there is
the maximum stopping power near this ion energy.
Time-resolved (TR) measurements revealed ultrafast
and broad luminescence preceding known luminescencebands. Furthermore, experimental results characterized the luminescence as follows, namely, its eﬃciency
showed the super-linear increase to excitation density,
the large dependence on the materials and the insensitiveness on temperatures; the decay-curve has no tailbeyond the exponential, and the spectral shift fromthe absorption edge was the large Stokes shift. These
results suggest the ultrafast luminescence corresponds
to the stimulated emission caused among adjacent e-hpairs.
This report exhibits the results for a single crystalof MgO. This material is known as a unique insulator that has strong free-exciton luminescence andshallow-trapped-exciton luminescence in the vacuum
ultraviolet region while it has no self-trapped excitons as are familiar in alkali halides. Under thepresent extremely high-density excitation, it is interesting whether free excitons can combine to form thestationary electron-hole plasma known in semiconductors, and also whether the ultrafast luminescence process is related to the radiation resistivity known in
MgO. Figure 1 shows a time-integrated luminescence
spectrum at 4 K obtained with cathode-ray irradiation,
TR luminescence spectra at low temperature for N,
Ar, and Xe ions, and that at room temperature for Ar
ion, from top to bottom. The spectrum obtained us∗1
∗2

Department of Quantum Engineering and Systems Science,
School of Engineering, University of Tokyo
Department of Applied Chemistry, School of Engineering,Tohoku University

Fig. 1. Excitation-density-dependent time-resolved luminescence spectra.

ing the cathode ray exhibits a sharp band at 162 nm
and a weak shallow-trapped exciton band on the rightside. The 162 nm band is due to free-excitons as reported so far. In contrast, the ion irradiated MgO revealed a new broad band at 180 nm, whereas the free
exciton band was quenched with increasing excitation
density, namely from electron to Xe irradiation, the
180 nm band appeared and increased in its intensity,
while the free exciton band increased in quenching rateand disappeared completely by Xe-ion irradiation. The
TR spectra at room temperature, given at the bottom,
show that luminescence eﬃciency of the new band does
not decrease markedly whereas that of the free excitons
disappeared completely. These results mean that the99new luminescence does not originate from the free excitons but the excited species in the earlier stage before
free excitons are created. Although the spectral shift
looks as if it is caused by the binding energy among
the free excitons, the value of 0.9 eV is too large. Otherwise, the shift associated with the trapping of thehole is reasonable. This trapping, however, is not due
to tight binding (deep trap) such as the self-trappingof the hole seen in alkali halides but due to shallow
one generated by orientation and displacement of O2−
surrounding holes (O− ) like polarons. This situation
is similar to that observed for the electron-hole plasma
in alkali halides.2) Thus, the present luminescence islargely diﬀerent from the e-h plasma known in laser
irradiated semiconductors. However, it is not the saneas that of alkali halides considering its much smaller
shift from the gap energy and smaller density of e-hpairs than the case of alkali halides. The e-h plasma
for MgO seems to a little expand in volume because ofshallow and mobile hole-trapping.

100

Lastly, the present photoemission seems to accountfor the radiation resistivity of MgO that it reduces thedefect production caused by the eﬀect of high-density
excitation. Recently, it has been reported that MgO
was the lowest in the sputtering yield on metal oxides
attributed to high-density excitation. The yields increased in the following order: MgO, A12 O3 , TiO2 ,and SiO2 .3) Contrarily, yields of the e-h plasma luminescence were reverse to this.
References
1) K. Kimura, J. Kaneko, S. Sharma, W. Hong, and N.
Itoh: Phys. Rev. B 60, 12626 (1999); K. Kimura, S.
Sharma, and A. Popov: Radiat. Meas. 34, 99 (2001);
Nucl. Instrum. Methods Phys. Res. B 191, 48 (2002).
2) K. Kimura: Nucl. Instrum. Methods Phys. Res. B 212,123 (2003).
3) N. Matsunami, M. Sataka, A. Iwase, and S. Okayasu:
Nucl. Instrum. Methods Phys. Res. B 209, 288 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Comparative study on electron-hole plasma formed inheavy-ion irradiated MgO and CdS
M. Koshimizu,∗ K. Kimura,∗ K. Asai,∗ and M. Kase
The irradiation eﬀects of swift heavy ions in semiconductors and insulators are characterized by highdensity electronic excitation along their paths. In order to understand the dynamics of high-density excitation states, we measured the time-resolved luminescence spectra using a SISP (single ion and single photon time correlation) system, with a time resolution of
80 ps. One of the authors (K. K.) observed the luminescence bands having very short lifetimes in alumina
and alkali halides.1,2) These bands can be ascribed tothe multiple interaction of the high-density excited carriers analogous to electron-hole plasma (EHP) in semiconductors.3) However, the detailed discussion is still
incomplete due to the diﬃculty in treating such an
excited state in insulators with strong electron-latticecoupling.
In this study, we aim to compare the dynamics of thehigh-density excited carriers produced by heavy ions in
MgO and CdS. In CdS, the electron-lattice couplingis very weak, and can be treated by considering thephonon scattering of the excited carriers. In contrast,in MgO, self-trapped excitons (STEs) are supposed to
be stable although self-trapped holes are not formed,
and a luminescence band due to free excitons is observed at low temperature.4)
In the time-resolved luminescence spectrum of CdS
at 15 K induced by 2 MeV/nucleon Xe ions, the spontaneous luminescence of EHP was observed, as shownin Fig. 1. We analyzed the shape of this band in accordance with Goebel,5) and we have obtained a carrier temperature and an electron-hole concentration of
15 K and 1.2 × 1019 cm−3 , respectively. In contrast,
for the case of 2 MeV/nucleon Ar irradiation, a rather
sharp luminescence band due to EHP was observed
at 12 K, and the carrier density was obtained to be
3.0 × 1018 cm−3 . This carrier density is consistent withthe results of calculation on the carrier diﬀusion dy-

namics taking into account the optical phonon scattering of the excited carriers, the method of which is
described for GaAs in Ref. 6. Therefore, the spatial
behavior of the excited carriers along the ion trajectory can be described in terms of the carrier-phonon
scattering.
For MgO, a free exciton (FE) band was observed
when the excitation density was low in the timeresolved luminescence spectra, as shown in manuscriptp. 99 in this volume of Riken Accel. Prog. Rep. As
the excitation increases, the FE band disappeared andthe intensity of a broad luminescence band at the lowenergy side of the FE band increased rapidly. The
quenching of the FE band can be analyzed quantitatively by considering the electrostatic screening of the
Coulomb force responsible for the exciton formation,
similarly to the case in semiconductors.3) By calculating the Mott density, at which excitons become unstable due to the electrostatic screening and the EHP isformed, the carrier density can be roughly estimatedfor excitation by each ion when the disappearance of
the FE band takes place. By using the values of thecarrier density, the spatial extent of the excited region,i.e., diﬀusion length, can be estimated to be about aslarge as 200 nm. This estimation may be reasonable
when one considers that a hole is not self-trapped inlattice distortion. Therefore, it is concluded that the
behavior of the high-density excited carriers along theion trajectory should be considered in terms of holelattice coupling, and the exciton-lattice interaction has
much less importance.
From the above consideration, the broad luminescence band at the low-energy side of the FE band canbe ascribed to the EHP. The Stokes shift of this bandis very large compared with the EHP band in semiconductors. This diﬀerence should be due to the lattice
distortions analogous to polarons. However, further
consideration is necessary to clarify the EHP dynamics in insulators.
References

Fig. 1. Time-resolved luminescence spectra of CdS irradiated with 2.0 MeV/n Xe (a) and Ar (b).
∗Department of Applied Chemistry, School of Engineering,Tohoku University

1) K. Kimura, S. Sharma, and A. I. Popov: Phys. Rev. B
60, 12626 (1999).
2) K. Kimura, S. Sharma, and A. I. Popov: Nucl. Instrum.
Methods Phys. Res. B 191, 48 (2002).
3) For review, see C. Klingshirn and H. Haug: Phys. Rep.
70, 315 (1981).
4) Z. A. Rachko and J. A. Valbis: Phys. Stat. Sol. (b) 98,
161 (1979).
5) E. O. Goebel: Appl. Phys. Lett. 24, 492 (1974).
6) M. Koshimizu, K. Asai, and H. Shibata: J. Lumin. 94,
407 (2001).

101

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RIKEN Accel. Prog. Rep. 37 (2004)

A new type of positron accumulator in UHV utilizing
a high-density electron plasma and an ion cloud
M. Niigaki,∗ T. M. Kojima, N. Oshima,∗ A. Mohri, M. Inoue,∗ K. Komaki,∗ and Y. Yamazaki
In the previous report,1) we have introduced a new
method which can accumulate positrons directly inultra-high vacuum (UHV) with an eﬃciency higher
than other UHV-compatible accumulators. The key ofour method is to utilize a high-density electron plasma
as an energy absorber of positron beams.
The setup of our system is shown in Fig. 1. It
consists of a slow positron source, an electron gun, aMulti-Ring Trap (the MRT —a kind of electromagnetic trap),2) a positron remoderator, a Faraday cup
and an annihilation γ-ray detector. Positrons and electrons are accomodated in electric potential wells (noted
as range (e) and (p)) which are formed by multiring
electrodes of the MRT. The γ-ray detector, the Faraday cup and the remoderator are used for diagnosesof charged particles. The total number of trapped
positrons Ne+ is measured by dumping them onto the
Faraday cup, and counting the number of annihilation
γ-rays by the γ-ray detector. The total number ofelectrons Ne− can be measured as the total amountof charges by collecting them at the Faraday cup or
remoderator.
The positron accumulation process includes four
steps: (1) formation of a high-density electron plasma
in range (e) by injecting electron beams, (2) injection of positron beams of ∼ 106 e+ /s from the slow
positron source, and remoderation by the remoderator(about 10–30% of them are reemitted), (3) energy loss
by Coulomb collision in the electron plasma, (4) trapping of decelerated positrons into range (p), and theirself-cooling via synchrotron radiation.
In this method, reinjection of positrons into the remoderator after step (3) causes a considerable decreasein the overall positron population. Hence, it is important to make the positron energy loss ∆K suﬃ-

ciently large in step (3) so that positrons can no longer
reach the remoderator. ∆K depends on the electron
column density σ = ne− · Le− , where ne− and Le−
are density and length of the electron plasma, respectively. Large ∆K can be achieved by using an electron
plasma with large σ. ∆K depends on the injectionenergy of reemitted positrons K, which is expressed
as K = e(VRM − Ve− ) + ERM , where e is elementary charge, VRM is the bias potential of the remoderator, Ve− is the electrostatic potential in the electron
plasma, ERM (∼ a few eV) is the initial energy ofpositrons reemitted from the remoderator. In orderto make ∆K suﬃciently large, a small K should beselected, because a smaller K allows longer collisiontime, and as a result, a larger momentum transfer. K
can be minimized to a few eV when VRM ≈ Ve− , andpositron trapping eﬃciency is maximized under thiscondition. Another important feature is that 108 ofH+
2 , created in range (p) by electron-beam injection at
step (1), are utilized at step (4). Positrons collide elastically with these ions, and it enhances trapping of decelerated positrons into range (p). We found these ionsenhance by 10-hold the positron trapping eﬃciency.
Figure 2 shows the measured positron trapping eﬃciency εt as a function of VRM . εt is deﬁned as the ratioof trapped positrons to those injected into the MRT.
Three results are shown here: (a) Ne− = 1.8×1010 , (b)Ne− = 1.6 × 1010 and (c) Ne− = 1.2 × 1010 . All data
were acquired with 50 s injection of 106 e+ /s beams.
Each peak corresponds to the “potential matching conditon”, i.e. VRM ≈ Ve− . It can be seen that the maxibecomes higher as Ne−
mum trapping eﬃciency εmaxt
is increased, suggesting that σ of the electron plasma∼ 1%
becomes larger together with Ne− . So far, εmaxt
has been achieved.

Fig. 2. Positron trapping eﬃciency εt as a function of remoderator bias VRM . Solid lines are guide for eyes.

Fig. 1. Setup of the system and schematic of the total procedure.
∗

102

Institute of Physics, University of Tokyo

References
1) N. Oshima et al.: RIKEN Accel. Prog. Rep. 36, 111(2003).
2) A. Mohri et al.: Jpn. J. Appl. Phys. 37, 664 (1998).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Soft X-ray spectroscopy of 2.3 keV/u N6+ ionstransmitted through a Ni microcapillary
Y. Iwai, Y. Kanai, Y. Nakai, T. Ikeda, H. Oyama, K. Ando, H. Masuda,∗1
K. Nishio,∗1 H. A. Torii,∗2 K. Komaki,∗2 and Y. Yamazaki
X-rays emitted from 2.3 keV/u N6+ ions transmitted through a thin Ni microcapillary foil were measured using a high-resolution soft X-ray spectrometerto study the formation and relaxation dynamics of ahollow atom (ion) produced by a resonant charge transfer in ion-surface collisions. This work will be compared with a previous result involving N7+ ions for the
study of incident charge dependence.1)
2.3 keV/u N6+ ions are supplied by a 14.5 GHz
Caprice electron cyclotron resonance ion source in
RIKEN.2) The microcapillary target was ∼1 mm2 inarea with a thickness of ∼1 µm and had a multitudeof straight holes ∼200 nm in diameter.3) The spectrometer consists of a concave grating and a chargecoupled device (CCD). For details of the spectrometer and methods of data analysis, see Ref. 4. X-ray
spectra were taken at five points downstream of thetarget along the ion beam. The points were immediately downstream of the target (T = 0), 0.15 mm(T = 0.22 ns), 0.35 mm (T = 0.52 ns), 1.00 mm (T =1.50 ns), and 2.75 mm (T = 4.10 ns) downstream,
where T is the time after passing through the target.
Figure 1 shows an X-ray spectrum, which was taken
immediately downstream of the target for 2.3 keV/uN6+ ions transmitted through the microcapillary. The
eight major lines are attributed to helium-like transitions, which are summarized in Table 1.5) It is expectedthat the relative intensity of each transition reflects the

Table 1. Observed transition energies and electronic configurations.
Experiment

Ref. data5) Configurations

426.1 ± 0.8 eV
430.4 ± 0.8 eV
497.8 ± 1.0 eV
521.8 ± 1.1 eV
532.7 ± 1.2 eV
538.7 ± 1.2 eV
542.2 ± 1.2 eV
544.5 ± 1.2 eV

426.3 eV430.7 eV498.0 eV521.6 eV532.6 eV538.5 eV542.1 eV544.6 eV

1s2p → 1s2
1s2p → 1s2
1s3p → 1s2
1s4p → 1s2
1s5p → 1s2
1s6p → 1s2
1s7p → 1s2
1s8p → 1s2

Terms
3

P1 → 1 S0
1
P1 → 1 S0
1
P1 → 1 S0
1
P1 → 1 S0
1
P1 → 1 S0
1
P1 → 1 S0
1
P1 → 1 S0
1
P1 → 1 S0

Cf.
552.1 eV§
§ N VI ionization potential energy

initial population and the cascade transitions of thehollow atom (ion).
Figure 2 shows the X-ray intensities for the 1s3p 1s2 , 1s2p 1 P - 1s2 , and 1s2p 3 P - 1s2 transitions as afunction of the time after the ion leaves the target. The
decay curves indicate lifetimes in nanoseconds. Since
the life of the 1s2p 1 P transition is estimated to bein picoseconds, this result provides information on the
decay process related to outer shells.6)

Fig. 2. X-ray decays of 1s3p - 1s2 , 1s2p 1 P - 1s2 , and 1s2p
3
P - 1s2 transitions.

References
Fig. 1. Spectrum of K X-rays measured using the spectrometer immediately downstream of the target (T = 0)
for 2.3 keV/u N6+ ions transmitted through a Ni microcapillary. The bars with transition terms show transition energies and N VI ionization potential energy.5)∗1∗2

Depertment of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University
Institute of Physics, Graduate School of Arts and Sciences,
University of Tokyo

1) Y. Iwai et al.: Nucl. Instrum. Methods Phys. Res. B
193, 504 (2002).
2) Y. Kanai et al.: Phys. Scr. T 92, 467 (2001).
3) H. Masuda et al.: Appl. Phys. Lett. 71, 2770 (1997).
4) Y. Iwai et al.: Nucl. Instrum. Methods Phys. Res. B
205, 762 (2003).
5) R. L. Kelly: J. Phys. Chem. Ref. Data 16, Suppl. 1(1987).
6) W. R. Johnson et al.: Adv. At. Mol. Opt. Phys. 35, 255(1995).

103

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RIKEN Accel. Prog. Rep. 37 (2004)

Coincidence measurements of X rays and final charge state of highly
charged ions transmitted through a microcapillary
Y. Kanai, Y. Nakai, Y. Iwai, T. Ikeda, K. Nishio,∗ H. Masuda,∗ and Y. Yamazaki
A slow highly charged ion (HCI) passing through a
microcapillary target captures target valence electrons
into high-n orbits while keeping inner shell vacancies.
The captured electrons are stabilized through cascading down via photon emissions and/or Auger electron
emissions. Some of the captured electrons emit X rays
at the ﬁnal stage of the stabilization. Ninomiya et al.1)
found that the lifetime of the K vacancy was as long as
10−9 s even with several electrons in the outer shells,
using N6+ ions which have a single K vacancy. It isinteresting to see how the inner shell ﬁlling processchanges when the incoming ions have multiple innershell vacancies. We have measured K (L) X rays in coincidence with the exiting charge states for 2.1 keV/u
N7+ (2.8 keV/u Ar ions) to study the ﬁlling processesof inner shell vacancies.
The experiments were carried out at the Slow Highly
Charged Ion Facility at RIKEN.2) 2.1 keV/u N7+ and2.8 keV/u Arq+ (q = 14, 13 and 9) ions were extracted
from a 14.5 GHz ECR ion source. The beams impinged
on a Ni microcapillary target along the capillary axis.
Fig. 1. Integrated delayed X-ray yields normalized by ion
A Si(Li) X-ray detector was placed at 90◦ to the beam
current as a function of the shield position for (a) Ar14+ ,axis. A shield located between the target and the(b) Ar13+ , (c) Ar9+ , and (d) N7+ incident.
BacktoContents
Si(Li) detector was movable along the beam direction,
shell) vacancy. This speculation is supported by Niand limited the detection region of the X-ray emisnomiya et al.’s results;1) they observed the same tension. The X rays emitted after t > t = z/v (v: ion vedency in the N6+ incident as we observed in the Ar9+locity, v = 0.64 mm/ns and 0.74 mm/ns for 2.1 keV/uincident as shown in Fig. 1 (c).
and 2.8 keV/u, respectively) were detected, when the
We must note that the peak positions of the X-ray
shield was located at z. The ﬁnal charge states qf ofspectrumcoincidence with the ﬁnal charge state shiftions were analyzed with an electrostatic charge state
to
a
lower
energy with decreasing ﬁnal charge state
analyzer. The diﬀerence between the initial qi and ﬁnal
and
do
not
shift
with the shield position.3) This result
qf charge states of ions gives the number s of the stamay be explained by either (1) (s-1) electrons rapidly
bilized electrons after the decay processes; s = qi − qf .
( 10−9 s) ﬁll the inner shell vacancies via photon
The X-ray spectra and yield coincident with the ﬁnal
emissions and/or Auger electron emissions and the lastcharge state were measured as a function of the shieldelectron slowly de-excites radiatively, or (2) (s-1) elecposition z.
14+trons slowly (∼ 10−9 s) ﬁlls the inner shell vacancies
inciAs shown in Fig. 1 (a) for 2.8 keV/u Ar
via Auger electron emissions and the last electron ﬁlldent,3) the X-ray yield coincidence with Ar13+ ionsthe inner shell vacancy by a radiative process.
which have only one stabilized electron s = 1, deWe do not have suﬃcient experimental and theocreases more rapidly than those with other charge state
reticalinformation on the decay schemes to explainions which have multiple stabilized electrons s > 1.
ourresults
consistently. We are planning to use (1) a
The same tendency can be seen in Fig. 1 (b) and (d) for
13+
7+
high-resolution
X-ray spectroscopy to identify the ﬁnal
and 2.1 keV/u N incident, respec2.8 keV/u Artransition
and(2)
an electron spectroscopy to detertively. On the other hand, this tendency is not ob9+
mine
the
role
of
the
Auger process in the total decay
served in Fig. 1 (c) for 2.8 keV/u Ar incident. This
process.
diﬀerence may be due to these being diﬀerent numbersof initial inner shell vacancies, because Ar14+ , Ar13+
References
and N7+ ions have multiple inner shell (L- or K-shell)
1) S. Ninomiya et al.: Phys. Rev. Lett. 78, 4557 (1997).
vacancies and Ar9+ ions have only one inner shell (K∗104

Department of Applied Chemistry, Tokyo Metropolitan University

2) Y. Kanai et al.: Physica Scr. T 92, 467 (2001).
3) Y. Kanai et al.: RIKEN Accel. Prog. Rep. 36, 109(2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Multiple-electron processes in close single collisionsof Neq+ (q = 2, 5, 7, and 9) with Ar at 14 keV
M. Hoshino,∗1 T. Kambara, Y. Kanai, S. Madzunkov,∗2 R. Schuch,∗2 and Y. Yamazaki
We study electron transfer in close single collisions ofslow highly charged ions (HCIs) with atoms, throughlarge-angle experiments. This work is motivated by
the intrinsic interest in the multiple-electron reaction
dynamics in slow and very close ion-atom collisions, inthe understanding of the neutralization in HCI-surface
interactions, and in the possible formation of the hollow atoms in HCI-atom collisions. Early experimental studies of very close collisions were performed withsingly charged ions.1) It is expected that the reaction
processes for singly and highly charged ions should bevery diﬀerent, that is, ionization in the former andmultiple-electron transfer in the latter. Only one study
on multiple-electron transfer in slow, close collisions
has been done, by Herrmann et al.,2) for a Ne9+ -Ne
symmetric system up to 4.2◦ at the collision energyof 90 keV. There is no experimental data on the projectile charge dependence of the outgoing ion charge
state in close collisions. The charge-state distributionsof recoil ions were measured for Neq+ (q = 2, 5, 7, and
9) on Ar at a ﬁxed projectile energy of 14 keV, or at avelocity of 0.17 atomic unit.
The experiment was carried out at a slow highly
charged ion facility of RIKEN. A 14-keV Neq+ (q = 2,
5, 7, and 9) beam from the 14.5 GHz Caprice-type ECR
ion source was collimated on a localized Ar gas target
from a needle. Scattered Ne ions and recoil Ar ionswere detected at 27◦ and 70◦ , which correspond to40◦ of the center of mass (CM) scattering angle, as
expected from the kinematics of elastic scattering forthis system. Each of the ion-detection systems consists of a time-of-ﬂight (TOF) drift tube which is set at
electrostatic potential, and a two-dimensional positionsensitive detector. For each coincidence event, the time
diﬀerence between the detections of the scattered andrecoil ions (∆TOF) and the positions of the both ionswere recorded. With the drift tube at electrostatic
potential one can modulate the ion velocity and determine the outgoing charge states by ∆TOF.
The recoil-ion charge state distributions were measured for Neq+ (q = 2, 5, 7, and 9) on Ar, where only
the drift tube for the recoil-ion detector was biased atabout −2.0 kV. Figure 1 shows the results for eachprojectile charge state. The recoil-ion charge increases
with the projectile charge.
For Ne2+ -Ar collision, the charge states of the recoilion (qr ) and scattered ion (qs ) were measured simultaneously by applying bias on both drift tubes. In Fig. 2,
the charge state distributions of scattered and recoil∗1∗2Fig. 1. The recoil ion distributions for each projectile
charge. (■) Ne2+ , (●) Ne5+ , (▲) Ne7+ , (◆) Ne9+ .

Fig. 2. The charge state distributions of scattered and recoil ions for Ne2+ -Ar.

ions for Ne2+ are shown. The most probable combination is (qs , qr ) = (2, 4). In such low-charge projectiles,
electron capture is not observed and ionization andelectron loss are the dominant reaction processes. For
high incoming charges, electron capture is expected to
be important.
References
1) E. Everhart and Q. C. Kessel: Phys. Rev. Lett. 14, 247(1965).
2) R. Herrmann et al.: Phys. Rev. A 46, 5631 (1992).

Department of Physics, Sophia University
Atomic Physics, Stockholm University, Sweden

105

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RIKEN Accel. Prog. Rep. 37 (2004)

Photodissociation for recovery of Ca+ ionslost by chemical reactions in an ion trap
K. Okada,∗1 M. Wada, T. Takayanagi,∗1 T. Nakamura,∗2 I. Katayama,∗2 and S. Ohtani∗3
An ion trap connected to an rf ion guide system will
be used for cooling and trapping energetic ion beams inorder to study the Bohr-Weisskopf eﬀects of unstablealkali earth ions.1,2) One of the serious problems insuch experiments is a chemical reaction of an objective
isotope ion with a water molecule during the coolingprocess. Generally, the collision-induced dissociation(CID) technique is applied to solve the problem. But,a high-pressure noble gas must be loaded to realize the
CID. Thus, photodissociation of such molecular ionswill be useful as a clean dissociation method.
In this short report, we present results of photodissociation experiments when trapped Ca+ ions are lost bychemical reactions with H2 O molecules. Details of theexperimental setup are described elsewhere.3) For detection of laser-induced ﬂuorescence from Ca+ ions, weused two laser diodes with oscillation wavelengths at
397 nm and 866 nm. In order to accelerate the reaction
with H2 O, Ca+ ions were pumped into the metastable
32 D3/2 state by turning oﬀ the 866 nm laser, and thenthe CaOH+ ions are eﬃciently produced. An important point is that the produced CaOH+ ions are still
trapped in the ion trap after the reaction. The dissociation energy of CaOH+ → Ca+ + OH was estimated by
the GAUSSIAN 03 program package.a) The photodissociation energy of CaOH+ is at least 4.6 eV, whichcorresponds to λ = 268 nm light. A deep UV lightof around 200–300 nm was extracted from a mercury
xenon lamp (200 W, Hamamatsu Photonics Co. Ltd).
The extracted UV light was focused on the center ofthe ion trap by a fused-silica lens.
In Fig. 1, we present a time spectrum of the ﬂuorescence intensity from trapped Ca+ ions during thechemical reaction and the photodissociation processes.
The wavelength distribution of the incident UV lignt
was ∼250 ± 10 nm, and the total power was ∼ 50 mW.
The clear ﬂuorescence increase, therefore the recovery of Ca+ from CaOH+ , was observed by irradiationof the UV light as shown on the right of the ﬁgure.
Since we carried out the experiment using a liquidnitrogen-cooled ion trap, the loss of reaction products
was considered negligible during the experiment. Accordingly, the ﬂuorescence intensity recovered the samelevel as in the initial state. The ﬂuorescence increase
as a function of UV exposure time is shown in the in∗1
∗2
∗3
a)

106

Department of Physics, Sophia University
Institute for Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
Institute for Laser Science, University of Electro-Communications
M. J. Frisch et al.: Gaussian Inc. (2003).

Fig. 1. A time spectum of fluorescence from trapped Ca+ions during the Ca+∗ (DJ ) + H2 O → CaOH+ + H reaction and the photodissociation process: CaOH+ + hν →Ca+ + OH. The insert shows a rise time profile of fluorescence incrase as a function of a UV exposure time.
H2 O pressure: 3×10−6 Pa.

set of Fig. 1. The rise time depends on the number of
CaOH+ ions and the eﬀective photon ﬂux for the photodissociation. The latter should vary with the peakwavelength of incident UV light. In order to roughly
estimate the wavelength dependence of the photodissociation, we inserted various UV ﬁlters with diﬀerent
transmittance properties in the optical path. Moreover, we tried to dissociate CaOH+ ions using a pulsed
266 nm laser, which was produced by 4th harmonic
generation (FHG) of a Nd: YAG pulsed laser. As a result, we could not observe any ﬂuorescence increase byirradiation of UV light with a longer wavelength than∼ 255 nm. A tunable UV laser is required for further
study of the wavelength dependence.
In summary, the photodissociation method by UV
or visible light from a high-power discharge lamp canbe applied to dissociate molecular ions or water cluster
ions containing long-lived isotope ions, such as 7,10 Be+
and 41,45,47 Ca+ even in the UHV condition.
References
1) M. Wada et al.: Nucl. Phys. A 626, 365c (1997).
2) M. Wada et al.: RIKEN Rev., No. 31, 56 (2000).
3) K. Okada et al.: J. Phys. B 36, 33 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Experimental apparatus for X-ray spectroscopy with highly
charged ion beam produced by laser ion source
S. Ozawa, M. Wakasugi, M. Okamura, M. Serata,∗ T. Koizumi,∗ and T. Katayama
In order to measure transitions of highly charged
ions, we are developing a new experimental techniquewhich uses soft X-rays instead of laser light. In thepresent situation, a high-quality X-ray beam that has
a resolution and intensity as high as those of laser lightis only available in the facility of synchrotron radiation,
thus the ion beam and the beam transport line must
be moved to the facility. The intensity of the X-ray
beam is several orders of magnitude less than that oflaser light. Therefore, a high-current ion beam is quite
important to compensate the defect.
The experimental setup is shown in Fig. 1. The Nd:
YAG laser, which has a maximum power of 450 mJ/
pulse and pulse duration (FWHM) of 6 ns, is used as
the laser ion source. The power density of the laser
radiation ﬂux on the ion source target is estimated tobe 1.2 × 1013 W/cm2 . The maximum repetition rateof the laser is 3 Hz during operation. The ion source isapplied with a maximum bias voltage of 100 kV. The
ion beam produced by the laser ion source is extracted
by an acceleration voltage and focused by the einzel
lens. Then the charge states of the ions are selected by
the dipole magnet, and the ion beam propagates to theﬂuorescence detector. The ion beam is focused in the
ﬂuorescence detector by the electrostatic quadrupolelens. In the detector, the ions excited by the X-ray
beam decay to the ground state with emitting ﬂuorescence photons. The resonance spectrum is obtained byscanning the X-ray energy, and the resonance energy
is obtained from the spectrum. The C4+ ion is chosen

for the target because this ion has an excitation energyof 300 eV which is suitable for synchrotron radiation.
The level scheme of the C4+ ion is shown in Fig. 2. The
detector has a cryopump system for achieving high vacuum (4 × 10−6 Pa) for the suppression of noise comingfrom the collisions of ions and residual gas molecules.1)
Four microchannel plates (MCPs) of 30 mm aperture(Hamamatsu 2224-21SFX) are mounted in the detector. A faraday cup of 10 mm aperture and a beam
proﬁle viewer made of ZnS are also located in the detector.
To verify the feasibility of the X-ray spectroscopy experiment, we estimated the count rate of ﬂuorescencephotons. Figure 3 shows a signal from the faraday
cup of the ﬂuorescence detector. The apertures of theslits located in the entrance and the exit of the dipole
magnet are 20 × 20 mm and 6 × 6 mm, respectively.

Fig. 2. Level scheme of C4+ ion.

Fig. 1. Layout of the experimental setup.
∗Department of Physics, Rikkyo University

107Fig. 3. Current of C4+ ion at the detector. Ions are accelarated by the voltage of 26 kV.

From the Fig. 3, the number of ions with a size of
10 mm is evaluated to be 1.3 × 108 ions/bunch. The
count rate of the ﬂuorescence (CR) is calculated by thefollowing formula. The parameters are summarized inTable 1.
ρx
· Ni · t · fi · Rlaser · εmcp · Ωd(1)
CR = B ·∆ν
Table 1. Parameters for estimation of the signal countrate.
Spontaneous transition probability (/s) A 8.873 × 1011
Power density of X ray (J/m3 )ρx 1.6 × 10−5
Repetition rate of laser (/s)
Rlaser3Band width of X ray (Hz)∆ν 7.4 × 1013
Quantum eﬃciency of MCP
εmcp
0.4
0.005
Solid angle of detectorΩd250Interaction ratefi
1.3 × 108
Number of ions (/bunch)
Ni
Interaction time (s)t
2 × 10−9108

The spontaneous transition probability (Einstein coeﬃcient) of the target transition is 8.873 × 1011 /s.2)
The induced transition coeﬃcient (B) is calculated
from the spontaneous transition probability. The CR
is estimated to be 0.3 cps. The X-ray intensity of1012 photons/s/0.1%bw is used for the estimation, because it is a realistic value for synchrotron radiation.3,4) The result indicates that the ion beam current
enables us to carry out an X-ray spectroscopy experiment with synchrotron radiation. Under the present
condition, the count rate of noise was measured to be
3 cps. As compared to the noise from the ion beam, thenoise from the X-ray beam oscillated by synchrotron
radiation is negligible. The noise from the X-ray beam
was measured at the beam line (BL-16B) of KEK Photon Factory (Proposal No.2002G023).4)
By improving of the noise level, we can increase thenumber of incident ions to the ﬂuorescence detector.
Consequently, we can use X rays with high resolution
because a high-resolution beam has an intensity lower
than the value in Table 1. If an experiment with X
rays with a resolution (E/∆E) of 10000 is possible, theexcitation energy of the target ions will be obtainedin the accuracy of more than 10−5 . In the case of the1s2 2s 2 S1/2 −1s2 2p 2 P1/2 transition of U89+ , it corresponds to 0.001 eV, and the accuracy will be one orderof magnitude higher than that in a previous experiment.5)
References
1) M. Wakasugi et al.: Nucl. Instrum. Methods Phys. Res.
A 419, 50 (1998).
2) http://physics.nist.gov/cgi-bin/AtData/main asd3) http://www.spring8.or.jp/4) http://pfwww.kek.jp/
5) J. Schweppe et al.: Phys. Rev. Lett. 66, 1434 (1991).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)µSR study on magnetic property of [Pd(dmit)2 ] salts†
S. Ohira, M. Tamura, R. Kato, I. Watanabe, and M. Iwasaki
The magnetic properties of low-dimensional quantum spin systems have been of interest in recent years.
In particular, the magnetic properties of a frustrated
two-dimensional (2D) Heisenberg triangular lattice antiferromagnet with S = 1/2 have been discussed theoretically with much attention. However, the existing substance is only few, thus the detailed magnetic
properties of these systems have not been suﬃciently
understood. [Pd(dmit)2 ] salts (dmit = 1,3-dithiol-2thione-4,5-dithiolate) have 2D distorted triangular lattice structures with spin-1/2, thus the spin frustration
operates here. Some of these salts have the antiferromagnetic (AFM) ground state.1,2) To understand themagnetic properties of such systems at ﬁnite temperatures, we carried out a muon spin relaxation (µSR)
measurement on two salts, β  -Me4 P[Pd(dmit)2 ]2 (1)and β  -Et2 Me2 P[Pd(dmit)2 ]2 (2), where Me = CH3
and Et = C2 H5 .
The experiment was carried out at the RIKEN-RAL
Muon Facility in the UK, using a 4 He cryostat down
to 1.5 K. Polycrystalline samples 1 and 2 were respectively wrapped with a silver foil to have a plate shapewith 20×20×1 mm3 , and ﬁxed onto the sample holderof the cryostat.
In the ZF-µSR measurement, an AFM transition
was observed at 40 K in 1 and at 15 K in 2 (Fig. 1). A
muon spin relaxation due to nuclear dipole ﬁelds wasobserved above TN , while muon spin precession signals
were observed below TN . The time spectra above TN2
were ﬁtted with A(t) = Ae−(σt) e−λt , where σ is the
distribution width of the random internal ﬁeld at themuon site, and λ is the muon spin relaxation rate due
to dynamically ﬂuctuating internal ﬁelds. The background has already been subtracted. The temperaturedependence of λ for the two salts is shown in Fig. 2.
We note that the AFM transition in 1 is quite sharp
compared with that in 2. The most important parameter aﬀecting TN in these salts is not the distance
between the layers but the ratio of the small transfer
integral to the large one in the layer, which shows a deviation from the regular triangular lattice. The values
for 1 and 2 are 0.6 and 0.8 respectively.3) The growthof ξ, which emerges from the intralayer anisotropy, israpidly exponential in the square lattice case, such thatit yields a 3D ordering in the presence of nonzero interlayer couplings.4) Therefore, it is expected that thegrowth of ξ in 1 is more rapid than that in 2 as a re-†Fig. 1. ZF-µSR time spectra of (a) 1 and (b) 2.

Fig. 2. Temperature dependences of relaxation rates of
Me4 P salt (1) and Et2 Me2 P salt (2).

sult of a more distorted packing. The sharp increasein λ just above TN observed for 1 is consistent withthis. Our result experimentally shows how ξ grows depending on the degree of anisotropy of the triangularlattice by observing the critical behavior for the AFM
ordering.
References
1) T. Nakamura et al.: J. Mater. Chem. 11, 2159 (2001).
2) M. Tamura and R. Kato: J. Phys.: Condens. Matter
14, L729 (2002).
3) S. Rouzière et al.: Phys. Rev. B 60, 3113 (1999).
4) M. Tamura and R. Kato: J. Physique IV-Proc., in press.

Condensed from the article in J. Physique IV-Proc., in press.

109

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RIKEN Accel. Prog. Rep. 37 (2004)

A change in the Cu-spin fluctuations studied by µSR in
La2−x Srx CuO4 at approximately 100 K
I. Watanabe, T. Adachi,∗1 Y. Koike,∗1 and K. Nagamine∗2
One of the fascinating models for describing themechanism of the high-Tc superconductivity is the socalled stripe model.1) This model assumes the microscopic segregation of spins and holes in the CuO2
plane forming stripes, which has theoretically been
discussed to be possibly important for the occurenceof the high-Tc superconductivity.2) In order to clarify
the correlation between the dynamical properties ofspins and holes, precise zero-ﬁeld muon-spin-relaxation(ZF-µSR) measurements have been carried out on
La2−x Srx CuO4 (LSCO) at the RIKEN-RAL Muon Facility over a wide range of hole concentrations fromx = 0.024 to 0.15, probing a change in Cu-spin dynamics at high temperatures of approximately 100 K
at which hole domains are expected to be formed.
Time spectra measured at high temperatures are analyzed using the function of A0 e−λt Gz (∆, t). A0 and λare the initial asymmetry at t = 0 and the dynamical
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.
Figure 1 shows the temperature dependence of λ of
LSCO with x = 0.115. λ starts to increase monotonically with decreasing temperature at aproximately
100 K, showing a change in the dynamics of the Cuspin ﬂuctuations. For convenience, the temperature atwhich λ starts to increase at a high temperature withdecreasing temperature is named Tµ , as shown by anarrow in Fig. 1. Solid lines in Fig. 1 show the bestﬁt results using a linear function. Figure 2 displays
the Tµ ’s of all samples as open circles. The superconducting transition temperatures determined from theresistivity measurements are also displayed as open triangles.
The temperature, T ρmin , at which the resistivity is
the minimum is read from ﬁgures in the literature3–5)
and plotted in Fig. 2 by closed triangles and squares.
It is found that the x dependence of Tµ is in good
agreement with that of T ρmin . This means that theorigin 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 thechange of dynamics of the Cu-spin ﬂuctuations, which
is an important feature of the stripe model.

Fig. 2. Phase diagram of La2−x Srx CuO4 . Lines are guids
for the eyes.

References

Fig. 1. Temperature dependence of the dynamical muonspin depolarization rate, λ, of La2−x Srx CuO4 with x =0.115.

∗1∗2

110

Department of Applied Physics, Tohoku University
Meson Science Laboratory, Institute of Materials Structure
Science, High Energy Accelerator Research Organization(KEK)1) J. M. Tranquada et al.: Nature 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).

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RIKEN Accel. Prog. Rep. 37 (2004)

99

Ru Mössbauer spectroscopic study of CaRuO3 (1)Y. Kobayashi, T. Okada, H. Haba, S. Jimbo,∗1 T. Taniguchi,∗1 Y. Noro,∗2 and Y. Nagata∗1
Following the discovery of unconventional superconductivity in copper-free layered perovskite
Sr2 RuO4 ,1) the electronic, magnetic, and superconducting properties of ruthenium oxides (ruthenates)
have been attracting strong interest in the past
few years.2–5) In particular, a series of ruthenates,(Ca, Sr)n+1 Run O3n+1 , have been known to showa wide variety of magnetic properties, where the electron conﬁguration of Ru ions is 4d4 in the low-spinstate. SrRuO3 and CaRuO3 , which are end members of this series, have nearly cubic and slightly distorted cubic perovskite structures, respectively. Although both ruthenates exhibit similar chemical andstructural characteristics, their magnetic properties
are quite diﬀerent. The results of static magnetic measurement, neutron diﬀraction, and Mössbauer studies
well established that SrRuO3 is an itinerant ferromagnet with a Curie temperature (Tc ) of 165 K. On theother hand, the magnetic properties of CaRuO3 at low
temperatures are not yet thoroughly understood, as
compared with those of SrRuO3 . The recent literature
contains contradictory results, for example, CaRuO3 is
a Pauli paramagnet, an exchange-enhanced paramagnet, an antiferromagnet, or spin-glass with long-rangeordering.
We have applied 99 Ru Mössbauer spectroscopy to
the series (Ca, Sr)n+1 Run O3n+1 in order to clarify themagnetic ground state of CaRuO3 as well as to understand comprehensively the origin of the magnetic
properties of this series.
As the electronic state of the ruthenates is very sensitive to the disorder around Ru ions, pure samples
are required to avoid the inﬂuences of magnetic impurities and defects. Single crystals of CaRuO3 wereprepared by the ﬂux method with powdered samples
as the starting material. Flux of a mixture of polycrystalline CaRuO3 and CaCl2 was ﬁred at 1300 C for
5 h and then cooled to 1100 C at the rate of 1 C/h. After the ﬂux was removed by washing out the crystals,
the chemical composition, the X-ray diﬀraction pattern, the magnetization, and the electrical resistivity
were measured. The above results and the characterizations were described in detail in Ref. 6.
The Mössbauer source nuclide 99 Rh (T1/2 = 15.0 d)
was produced by the 99 Ru(p, n)99 Rh reaction with
12 MeV protons accelerated by the AVF Cyclotron.
Metal powder of enriched 99 Ru was used as the target,
and the irradiated target was used as the Mössbauer
source with no prior heat or chemical treatment.7)
As the Mössbauer γ-transition of 99 Ru is as high as∗1∗2

90 keV, both the source and absorber of CaRuO3 were
kept below 5 K. 99 Ru Mössbauer spectra were obtainedusing the conventional Mössbauer spectrometer.
The temperature dependence of the magnetic susceptibility of CaRuO3 follows the Curie-Weiss law inthe high-temperature region above about 50 K, but
gradually deviates from the law upon lowering the temperature to 1.7 K. The eﬀective paramagnetic moment(peﬀ ) and the paramagnetic Curie temparature (θ) are
derived to be 2.82µB and −77 K, respectively.
The 99 Ru Mössbauer spectra on CaRuO3 were measured at 5 and 2 K. The spectrum at 5 K is shownin Fig. 1. The spectra down to 2 K apparently consist of doublets with slight asymmetry, as typically observed in the case of an electric quadrupole interaction
with no appreciable hyperﬁne magnetic interaction,
and were analyzed satisfactorily under the assumptionof a pure electric ﬁeld gradient with an axial symmetry. The derived isomer shift and quadrupole splitting are −0.31 mm/s and −0.33 mm/s, respectively.
Our Mössbauer results of CaRuO3 are consistent withthe absence of anomaly in the magnetization measurement. Thus, on the basis of the results of the present
study it is concluded that CaRuO3 has no magnetic
interactions between 2 and 300 K.

Fig. 1. A 99 Ru Mössbauer spectrum of CaRuO3 single crystals at 5 K. The isomer shift is taken relatively to ruthenium metal.

References
1) Y. Maeno et al.: Nature 372, 532 (1994).
2) K. Yoshimura et al.: Phys. Rev. Lett. 83, 4397 (1999).
3) H. Mukuda et al.: Phys. Rev. B 60, 12279 (1999).
4) I. Felner et al.: Phys. Rev. B 62, 11332 (2000).
5) I. Felner et al.: Physica B 337, 310 (2003).
6) A. Koriyama et al.: J. Alloys Compd. 171, 339 (2003).
7) Y. Kobayashi et al.: Inorg. Chem. 31, 4570 (1992).

Department of Physics, Aoyama Gakuin University
Kawazoe Future Technology

111

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RIKEN Accel. Prog. Rep. 37 (2004)

Reactions of 57 Mn implanted in solid oxygen
Y. Yamada,∗1 Y. Kobayashi, H. Ueno, K. M. Kubo,∗2 H. Watanabe, A. Yoshimi,
H. Miyoshi,∗3 D. Kameda,∗3 and K. Asahi
We are planning to perform experiments to study
the electronic structures of 57 Fe atoms decayed from57
Mn implanted in solid oxygen by in-beam Mössbauer
spectroscopy, in order to determine iron species withextraordinarily high oxidation states. Here, we brieﬂy
discuss a preliminary study on novel iron oxide species
produced by laser evaporation and matrix isolationin relation to our previous study on 57 Mn atoms implanted in KMnO4 to produce Fe(VIII) species.
Reactions of laser-evaporated iron atoms with oxygen gas, which produced various novel iron oxide
species, were studied.1) Oxidation of iron is a fundamentally and chemically interesting subject because itis related to corrosion of materials and catalytic reactions. The simplest oxidation reaction of iron is thereaction of an iron atom with oxidizing gas. Thus, weinvestigated the reactions of laser-evaporated Fe atoms
with oxygen gas by matrix isolation. Laser-evaporated
iron atoms were isolated in low-temperature Ar matrices and their chemical reactions with oxygen were
investigated by conventional Mössbauer spectroscopy.
Reactions of these iron atoms with oxygen produced
FeO, Fe(O2 ), FeO3 , (O2 )FeO2 , and OFeO. While
Fe(O2 ) maintains an O-O bond and has a side-on O2
molecule, O-Fe-O has two O atoms without an O-Obond between them. In the case of laser-evaporated
iron atoms, the highest oxidation state found among
the iron oxide species was VI: FeO3 .
The 57 Fe atoms decayed from 57 Mn have extremely
higher energy than the laser-evaporated Fe atoms upon
implantation and decay, which provides important information on chemistry under extreme conditions andon the production of novel species. We have obtained
well-resolved in-beam Mössbauer spectra of 57 Fe arising from 57 Mn implanted in KMnO4 between 11 K and
155 K.2) A manganese atom in KMnO4 is in a VII stateand forms a [MnO4 ]− tetrahedron. On the basis of theMössbauer parameters, the 57 Fe atoms in Mn sites ina [MnO4 ]− tetrahedron were found to have an unusually high valence state of Fe(VIII).
While 57 Fe implanted in KMnO4 may suﬀer geometrical hindrances of [FeO4 ]− in a solid KMnO4 crystal,57
Fe implanted in solid oxygen may have less geometrical restriction of the matrix, and may react to form
Fe(VIII) species with a stable geometrical structure.
As the highly charged 57 Mn atoms are implanted in

∗1
∗2
∗3

112

Department of Chemistry, Tokyo University of Science
College of Liberal Arts, International Christian University
Graduate School of Science and Engineering, Tokyo Institute of Technology

solid oxygen with high translational energy, Mn(VII)oxide species may be produced and trapped in a solid
oxygen matrix, followed by a decay process forming
57
Fe oxide species. The novel iron Fe(VIII) oxide
species may have diﬀerent structures from those obtained by our previous study of 57 Mn implanted insolid KMnO4 . This experiment will conﬁrm our ﬁnding of the unusually high valence state of Fe(VIII).
Furthermore, the in-beam Mössbauer technique is very
sensitive such that a very small amount of 57 Fe can bedetected. Consequently, the iron oxide species produced by implantation can be well isolated, and theirsimple Mössbauer spectra can be analyzed. Althoughvarious by-products are also expected to be produced,
the Mössbauer parameters of various iron oxide species
have been obtained by our previous experiments using
the laser-evaporated iron atoms, which makes the analysis of the Mössbaur spectra easier.
Prior to the experiments of 57 Mn implanted insolid oxygen, we performed an experiment using laserevaporated iron atoms. Laser-evaporated 57 Fe atoms
were deposited on solid oxygen (20 K), and theirMössbauer spectra were obtained. The amount of 57 Fe
deposited on solid oxygen was varied in order to determine the eﬀect of the products. The type of products on the surface of solid oxygen varied depending on
the amount of iron atoms. When the amount of ironatoms is large, the Mössbauer spectra of the products
show magnetic splitting because of the magneticallyordered iron oxide produced on the low-temperaturesolid oxygen surface. In contrast, when the amount ofiron atoms is small, magnetic splitting is not observedin the Mössbauer spectra of the products and a doublet absorption is observed, which is attributed to theisolated single Fe(O2 ). It was demonstrated that laserevaporated iron does not have suﬃcient translationalenergy for implantation in solid oxygen; rather, most of
the reactions take place on the surface of solid oxygen.
References
1) Y. Yamada, H. Sumino, Y. Okamura, H. Shimasaki, andT. Tominaga: Appl. Radiat. Isot. 52, 157 (2000).
2) Y. Kobayashi, M. K. Kubo, T. Saito, H. Ueno, H.
Miyoshi, K. Yoneda, W. Sato, and Y. Yamada: J. Radioanal. Nucl. Chem. 255, 403 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Accumulation of various trace elements in Lotus japonicus
using the multitracer technique
R. Hirunuma, K. Igarashi, H. Saito, Y. Miyazawa, H. Haba, H. Takeichi, T. Abe, and S. Enomoto
Newly discovered toxic metal hyperaccumulator
plants (Lotus japonicus) hold promise for phytoremediation of toxic-metal-polluted soil and rivers.
Lotus japonicus has been proposed as a model leguminous plant for molecular genetic study. We reporta study of uptake, distribution, and accumulation ofvarious trace elements in Lotus japonicus (Miyakojima
MG-20 and Gifu B-129) using the multitracer technique.
Forty seedlings of each variety (Miyakojima MG-20
and Gifu B-129) were grown on soil for about 2 months
in a growth chamber under a daily 16 h light/8 h darkcycle at 25◦ C. After blooming and the start of seed
growth, the plants were cultivated in a nutrient solution containing a multitracer prepared using an Agtarget. Five plants of each variety were transplanted
to a 1000 mL plastic pot containing 500 mL of themultitracer solution for 1 week. The plant samples
were in contact with the solution via their roots. After
1 week, the plants were carefully removed from thesolution and divided into roots, primary shoot (shootapex; upper part; middle part; lower part), secondary
shoots, flowers, pods, and seeds. The roots were
washed with a nutrient solution without multitracer
for one minute using an ultrasonic cleaner and dried
with filter paper. These samples were dried at 60◦ C for
3 days. The radioactivities in these samples were determined by γ-ray spectrometry using high-purity Ge
detectors.
The behaviors of Be, Na, Sc, V, Cr, Mn, Fe, Co, Zn,
As, Se, Rb, Sr, Y, Zr, Tc, Ru, and Rh were determined.
The amounts of trace elements in the whole plant andthe above-ground parts are shown in Table 1. In the
Table 1. Uptake (%) of trace elements in Lotus japonicus.

Fig. 1. Uptake ratios of Tc, Sr, Rb, and Zn into plant parts(Uptake rate (%/g) in each part/uptake rate (%/g) inwhole plant).

whole plant, uptakes of all elements except Na were
high. The uptakes of trace elements in the whole plantof Miyakojima MG-20 were the same as those of Gifu
B-129. In the above-ground parts, Cr, Ru, Sc, andZr were not detected, and Be, Fe, Rh, V, and Y were
only slightly detected. On the other hand, uptakes ofTc, Sr, Rb, and Zn were high. Thus, while Cr, Ru,
Sc, Zr, Be, Fe, Rh, V, and Y were not absorbed orabsorbed only in small amounts into plants, Tc, Sr,
Rb, and Zn were confirmed to be absorbed. Although
Fe is an essential element, the amount of Fe absorbed
into plants was nominally detectable. The uptakes ofTc, Sr, Rb, and Zn in Miyakojima MG-20 were higher
than those in Gifu B-129.
Figure 1 shows the uptake ratios of Tc, Sr, Rb, and
Zn into individual parts. Technetium was found to
be widely distributed among primary and secondary
shoots. High Tc concentration was found in primary(shoot apex and upper part) and secondary shoots.
Low Tc concentration was found in seeds, pods, andflowers. Strontium was found mainly in the primaryshoot. Rubidium was found to be widely distributed
among all parts expect the flowers. High Rb concentration was found in seeds. Zinc was found to
be widely distributed among all parts. High Zn concentration was found in seeds and the primary shoot(lower part). The accumulation of Zn into seeds of
Miyakojima MG-20 was the highest.
In the next experiment, the transport of various elements from soil to plants will be investigated and thetransfer factor of Lotus japonicus will be calculated.

113

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RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀects of carnosine (β-alanyl-L-histidine) on the absorption ofvarious trace elements in rats
K. Igarashi, R. Hirunuma, H. Haba, S. Kimura∗ , and S. Enomoto
Carnosine (β-alanyl-L-histidine) was ﬁrst identiﬁedin beef extract in 1900. It is found in millimolar concentrations in skeletal muscles and brains of animals.
Numerous studies have reported the speciﬁc propertiesof carnosine. One of the major functions of carnosine
is to act as a natural antioxidant. It is an eﬃcient oxygen scavenger and protects phage against γ-irradiation
which causes oxidative DNA damage.1) On the other
hand, carnosine has a chelating property for metals.
Carnosine-metal complexes exhibit a superoxide dismutase (SOD)-like activity.2) Furthermore, the pharmacological activity of the carosine-Zn complex has
been studied in recent years.3) However, it is possiblethat carnosine may inﬂuence the absorption of metals.
Thus, to investigate the eﬀects of carnosine on theabsorption of metals, we determined the uptake rate ofvarious trace elements in rats administered carnosineusing a multitracer technique.
A multitracer solution was prepared from an Agtarget irradiated with a heavy-ion beam of 135 MeV/
nucleon accelerated in the RIKEN Ring Cyclotron.
Rats were administered the multitracer solution withcarnosine (dose, 10 mg/rat) into the stomach througha tube. The rats were kept in cages and sacriﬁced 1, 3,
6 and 24 h after carnosine administration. Then, theliver, kidney, bone, muscle, brain and blood were collected. These samples were placed in a Ge-detector,
and the radioactivities of the multitracers were measured. In this study, the amounts of Co, Zn, As and
Se incorporated into the various tissues and blood ofrats were determined.
Figure 1 shows the uptake rates of Zn into the blood,intestine, liver, kidney, brain and muscle in rats. In
both the control and the carnosine-administered rats,
the rate of Zn uptake into the blood was maintainedat the same level after 24 h. The amount of Zn uptake into the intestine decreased in a time-dependent
manner, while those into the liver, kidney, brain andmuscle increased at 24 h. The uptake rates of Zn in
the blood and tissues of the carnosine-administeredrats were signiﬁcantly lower than those of the control rats. Similarly, the carnosine-administered rats
exhibited signiﬁcant decrease in uptake rates of Co
into the blood and tissues compared with the control∗

114

Graduate School of Human Life Sciences, Showa Women’s
University

Fig. 1. The uptake rates of Zn into the blood, intestine,
liver, kidney, brain and muscles in rats. : control
rats, : carnosine-administered rats. § Significant differences were observed between control and carnosineadministered rats (P < 0.05).

rats. Furthermore, the carnosine-administered rats exhibited slightly reduced Se uptake rates into the bloodand tissues compared with the control rats. Although,the uptake rates of As into the blood, intestine andkidney of the carnosine-administered rats were significantly lower than those of the control rats, no significant diﬀerences in As uptake rates into other tissues
were observed between the carnosine-administered andcontrol rats.
These results suggest that carnosine administration
decreased uptake rates of Zn, Co, Se and As into thebody. However, it is considered that the results ofthis study were aﬀected by a substantial diﬀerence inadministration volume between carnosine and trace elements.
References
1) T. A. Dahl et al.: Photochem. Photobiol. 47, 357(1988).
2) R. Kohen et al.: Free Radical Res. Commun. 12/13,
179 (1991).
3) M. Seiki et al.: Folia Pharmacologica Japonica, 95, 257(1990).

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RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀects of carnosine (β-alanyl-L-histidine) on the absorptionof iron in rats
K. Igarashi, R. Hirunuma, S. Kimura,∗ and S. Enomoto
Iron deﬁciency is probably the most frequent nutritional disorder in the world. One of the main causative
factors is the poor absorption of dietary iron. There
are two types of iron in food. Heme iron from meat,
poultry and ﬁsh has a high intestinal absorption eﬃciency, because heme iron directly enters the mucosal
cells. On the other hand, the intestinal absorption of
nonheme iron, the main form of dietary iron, is inﬂuenced by other food components. The bioavailability of nonheme iron has been extremely low because
inhibitors, such as phytic acid and polyphenols, bindnonheme iron in the intestinal lumen. The absorption
rate of vegetable iron is only about 1–2%.1) Therefore,
the enhancement of nonheme iron absorption is important for improving iron nutrition.
It is well established that the bioavailability of nonheme iron from foods is enhanced by vitamin, organicacid, meat, poultry and ﬁsh. Ascorbic acid and citricacid maintain iron in a more soluble and absorbableform, and prevent its binding to inhibitory ligands.2)
Although meat stimulates nonheme iron absorption,
the factor in meat responsible for enhancing nonheme
iron absorption is yet to be identiﬁed.
A number of putative roles have been ascribed to thehistidine-containing peptides. Carnosine (β-alanyl-Lhistidine) and anserine (β-alanyl-3-methyl-L-histidine)
are observed in millimolar concentrations in the skeletal muscles and brains of animals, although there
are substantial diﬀerences in their tissue distributions.
These compounds have been proposed to act as natural antioxidants in vivo.3) Furthermore, carnosine wasreported to enhance recovery from exhaustion due toits buﬀering capacity.4) A signiﬁcant eﬀect of carnosine
is its ability to prevent, or partly reverse, lens cataract.
Recently, the pharmacological activity of the carosinemetal complex has been studied.5)
Thus, to identify the factor in meat that enhancesof the nonheme iron absorption, we determined the∗eﬀects of carnosine on the absorption of iron in rats.
We used the cannulation system for investigating ironabsorption in rats that were administered with carnosine because it is eﬀective determining of the biologicalresponse to infused samples into the stomach or intestine in conscious rats.
Six-week-old male Wistar rats are purchased andhoused in stainless steel cages in a temperatureand light-controlled room. The method of cannula
preparation is as described by Taguchi et al. andSpannagel et al.6,7) That is, the rats are anesthetizedwith enﬂurane and prepared with Silastic cannula for
carnosine and iron administrations into the stomach.
They are also prepared with a jugular vein cannula forcollecting blood. Cannulas from the abdominal cavity
are placed under the skin to exit on the back. After
closure, the rats are placed in Bollman type restraint
cages modiﬁed to provide the minimum restraint possible. Three days after surgery, the rats are administered carnosine and iron into the stomach simultaneously. Then the blood is collected at regular intervals,
plasma and blood cells are separated by centrifugation(3000 rpm for 15 min). To determine the bioavailability of iron, serum iron concentration is measured using
a kit by the Nitroso-PSAP method.8)
References
1) L. Hallberg: Ann. Rev. Nutr. 1, 123 (1981).
2) I. M. Zijp et al.: Crit. Rev. Food Sci. Nutr. 40, 371(2000).
3) M. A. Babizhayev et al.: Biochem. J. 304, 509 (1994).
4) R. Harada et al.: J. Jpn. Soc. Nutr. Food Sci. 55, 209(2002).
5) M. Seiki et al.: Folia Pharmacologica Japonica 95, 257(1990).
6) S. Taguchi et al.: Jpn. J. Clin. Physiol. 24, 241 (1994).
7) A. W. Spannagel et al.: Am. J. Physiol. 270, G128
(1996).
8) M. Saito et al.: Bunseki kagaku 30, 635 (1981).

Graduate School of Human Life Sciences, Showa Women’s
University

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RIKEN Accel. Prog. Rep. 37 (2004)

Multitracer screening of trace elements in brains ofmice injected with lipopolysaccharide
M. Ono,∗ H. Yokokawa,∗ S. Enomoto, and R. Amano∗
It is well known that by injection of lipopolysaccharide (LPS) in mice, the outbreak of endotoxic shock
gives rise to impediments in the blood brain barrier(BBB), as described by Minami et al.1) However, thebehavior of trace elements in the brain has not been
elucidated under these impediments. In this work, we
examined the movement of trace elements in the brainsof mice injected with LPS using the multitracer technique.
A multitracer solution was obtained from a Ag
target irradiated for two days with a 12 C beam at
135 MeV/nucleon accelerated in RIKEN Ring Cyclotron. Then, the Ag target was removed by chemical separation and the multitracer was prepared as aphysiological saline solution. The multitracer solution
contained 8 radioisotopes, namely, 46 Sc, 54 Mn, 58 Co,
65Zn, 75 Se, 83 Rb, 88 Zr, and 88 Y.
In this screening, two mouse groups (LPS-treatedand normal groups), consisting of six 12-week-old
ICR mice each, were prepared. The treated mice
were injected intraperitoneally with LPS at a dose of
15 mg/kg1) (dissolved in the physiological saline solution). The multitracer solution was injected intravenously via the tail 24 hours after LPS treatment.
Blood and brain samples were obtained 30 min after
the multitracer injection. The blood was centrifuged
to obtain the plasma fraction. The plasma and brain
samples were then freeze-dried and assayed by γ-ray
spectroscopy using high-purity Ge detectors.
Table 1 summarizes the plasma retention rate andthe brain uptake rate of 46 Sc, 54 Mn, 58 Co, 65 Zn, 75 Se,
83
Rb, 88 Zr, and 88 Y. Except for 88 Y, no signiﬁcantdiﬀerence in plasma retention rate was observed between the LPS-treated group and the normal group.
On the other hand, the brain uptake rates of 54 Mn,
58
Co, 65 Zn, 75 Se, and 83 Rb in LPS-treated mice weremarkedly lower than those in normal mice. Moreover,54
Mn showed a very distinctive result: the brain uptake rate was clearly decreased while the plasma retention rate was increased, as shown in Fig. 1.
From this result, LPS is considered to cause impediments in the brain movement of 54 Mn. We are interested in this behavior of Mn in LPS-treated mice.
Further study is required to clarify the observed behavior of 54 Mn using the singletracer technique.

Fig. 1. 54 Mn brain uptake rate and plasma retention ratein mice 30 min after multitracer injection. The bar
represents the mean±S.D. for six mice.

References
1) T. Minami et al.: Environ. Toxicol. Pharmacol. 5, 35(1998).

Table 1. Brain uptake rate and plasma retention rate in mice 30 min after multitracer injection.

46

Sc
Mn
58
Co
65
Zn
75
Se
83
Rb
88
Zr
88
Y
54

Brain Uptake rate (%dose/g)
Normal group LPS-treated group

Plasma Retention rate (%dose/g)
Normal group LPS-treated group0.03 ± 0.006
0.24 ± 0.029
0.04 ± 0.009
0.15 ± 0.014
0.03 ± 0.003
0.07 ± 0.004
0.01 ± 0.003
0.01 ± 0.002

11.31 ± 1.08
0.41 ± 0.04
1.50 ± 0.16
0.55 ± 0.12
1.49 ± 0.18
0.07 ± 0.02
6.52 ± 0.73
3.42 ± 0.34

0.04 ± 0.011
0.03 ± 0.007§2
0.08 ± 0.010§20.04 ± 0.003§20.10 ± 0.018§1
0.04 ± 0.004§2
0.02 ± 0.003
0.02 ± 0.002

11.76 ± 3.26
0.63 ± 0.18
0.94 ± 0.18
0.39 ± 0.20
1.15 ± 0.46
0.09 ± 0.01
9.09 ± 2.82
8.60 ± 2.84§1Each value represents the mean±S.D. of data from six mice. §1 and §2 indicate
signiﬁcant diﬀerences of normal group versus LPS-treated group. §1 : P < 0.01
§2
: P < 0.005∗

116

School of Health Sciences, Faculty of Medicine, Kanazawa
University

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RIKEN Accel. Prog. Rep. 37 (2004)

Pharmacokinetic study on gastrointestinal absorption andblood disposition of vanadium ions in healthy rats
using radiotracer method
H. Yasui,∗ Y. Adachi,∗ J. Fugono,∗ H. Haba, A. Nakayama, R. Hirunuma, S. Enomoto, and H. Sakurai∗
In recent years, vanadium compounds have been
demonstrated to exhibit insulinomimetic eﬀects in in
vitro and in vivo experiments, and used to treat
both insulin-dependent type 1 and insulin-independent
type 2 diabetes mellitus. We have reported that
vanadyl complexes normalize the blood glucose level of

streptozotocin-induced type-1 diabetic rats and hereditary type-2 KK-Ay mice.1) To understand the action
mechanism of vanadium treatment, in this study, we
focused on investigating the pharmacokinetics of gastrointestinal absorption and disposition of vanadiumions in the blood of healthy rats by administration of
their radiotracers.2)
As shown in Fig. 1 (A), the clearance curves of 48 V
in the blood of healthy rats receiving intravenous injection of vanadyl (48 VO2+ ) and vanadate (48 VO4 3− )ions were not signiﬁcantly diﬀerent in spite of the administration of diﬀerent chemical species of vanadiumions with diﬀerent oxidation states,3) probably becauseof the rapid reduction of vanadate to vanadyl in the
blood and organs of rats which has been reported.4)
On the other hand, as shown in Fig. 1 (B), the absorption of 48 VO4 3− was found to be 3-fold higher
than that of 48 VO2+ , suggesting the chemical speciesdependent transport mechanism on the gastrointestinal absorption of vanadium in animals.5) The bioavailability values of 48 V after oral administration of48
VO2+ and 48 VO4 3− ions in healthy rats were estimated to be 4.9% and 14.6%, respectively, which coincides well with the results in rats given nontracer
VOSO4 and NaVO3 , strongly indicating the need fordeveloping vanadium complexes with higher bioavailability which contribute to a higher hypoglycemic activity than that of vanadium ions after oral administration.
References

Fig. 1. Clearance curves of 48 V in the blood of rats given
intravenous injection (A) and oral administration (B) of
500 µL of 48 V solution reduced with (; 48 V(IV)O2+ )or without (●; 48 V(V)O4 3− ) 100 µM sodium ascorbate.
Data are expressed as the means ± SDs for 4 rats.

∗

1) H. Sakurai: Chem. Rec. 2, 237 (2002); H. Sakurai et al.:Coord. Chem. Rev. 226, 187 (2002); H. Sakurai et al.:Expert Opin. Investig. Drugs 12, 1189 (2003).
2) K. Yamaoka, T. Nakagawa, and T. Uno: J. Pharmacokinet. Biopharm. 6, 547 (1978).
3) D. C. Crans and A. S. Tracey: ACS Symp. Ser. 711, 2(1998).
4) H. Sakurai, S. Shimomura, K. Fukuzawa, and K. Ishizu:
Biochem. Biophys. Res. Commun. 96, 293 (1980); M.
Ding et al.: J. Inorg. Biochem. 55, 101 (1994).
5) L. C. Cantley, Jr. et al.: Nature 272, 552 (1978); A.
Rolfs et al.: Curr. Opin. Gastroenterol. 17, 177 (2001).

Department of Analytical and Bioinorganic Chemistry,
Kyoto Pharmaceutical University

117

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RIKEN Accel. Prog. Rep. 37 (2004)

Uptake of 65 Zn in various trophoblast cells
N. Asano,∗ C. Ebihara,∗ M. Kondoh,∗ M. Fujii,∗ S. Enomoto, and Y. Watanabe∗
Zinc is a vital metal that plays a pivotal role in thenormal growth and development of the fetus. Deﬁciency of maternal zinc results in abnormal development of the fetus.1) During pregnancy, zinc is transferred from maternal blood to fetal blood across theplacenta, and the zinc level in fetal serum is up to
2-fold higher than that in the maternal serum at theend of pregnancy.2) However, the mechanism of zinctransport in the placenta is not clear.
Zinc is a multifunctional element involved in transcription, metalloenzyme activities and maintenance ofprotein structure. Therefore, organisms are equippedwith mechanisms for controlling intracellular zinc levels and localization. In general, intracellular zinc
homeostasis is maintained by the control of zinc eﬄux,
inﬂux and storage. Zinc is not absorbed by simple diffusion because of its hydrophilic and highly charged
properties. Zinc kinetics is regulated by speciﬁc transporters of zinc. Zinc transporters are now classiﬁed
into two categories: the ZnT family of transporters,
which controls zinc eﬄux, and the ZIP family of transporters, which controls zinc inﬂux.3,4) For example,
ZnT1 is a transporter that regulates eﬄux of zinc fromthe plasma membrane, and ZnT3 is involved in the efﬂux of zinc from the cytosol into the intracellular zincpool. ZnT5 transports zinc from the cytosol into thetrans-Golgi network, and ZIP1, located in the plasma
membrane, plays a key role in the intracellular uptakeof zinc. Deﬁciency of ZnT1 results in zinc toxicity andembryonic lethality, and ZnT3 is involved in the accumulation of zinc in neuron synapsis. ZnT5 plays roles
in osteoblast maturation in the bone and in formationof insulin crystals by the transport of zinc into secretory granules in pancreatic β cells. ZnT4 functions
as a transporter of zinc into breast milk during lactation in the mammary glands. Defects in ZIP4 areresponsible for the onset of acrodermatitis enteropathica, an inherited disease of zinc metabolism. Thus, zinctransporters are associated with various physiologicalevents.
The expression of some ZnT transporters, including ZnT1, ZnT2 and ZnT5, has been detected in theplacenta.4,5) However, their functions have not been
elucidated. Although we have investigated the expression of zinc transporters in various trophoblast celllines, we have never examined zinc uptake. Here, wedeveloped an assay system for measuring zinc uptake∗

118

Department of Pharmaceutics andShowa Pharmaceutical University

Biopharmaceutics,

in trophoblasts using 65 Zn.
We used a cell culture model of human choriocarcinoma cells, BeWo and JEG-3 cells and of rodent choriocarcinoma cells, Rcho-1 cells. BeWo cells,
JEG-3 cells (5 × 105 cells/ml), and Rcho-1 cells(1 × 105 cell/ml) were seeded on 24-well plates. Afterat least 12 hr of culture in a fetal-calf-serum-deﬁcientmedium, the cells were washed twice with HBSS solution (Ca, Mg free). Then the cells were incubated with
5 µM 65 ZnCl2 for 1 or 30 min. The cells were washedthree times with ice-cold PBS containing 1 mM EDTA,
and then 200 µl of 1% TritonX-100 was added. Radioactivity and amounts of protein in the lysate were
determined. As shown in Fig. 1, the amounts of Zn
uptake were diﬀerent among the cells under this condition. Since zinc homeostasis is achieved through various zinc transporters, the expression proﬁle of zinctransporters may be diﬀerent among cell lines. In order to clarify the functions of zinc transporters, timecourse change and dose-dependency of Zn uptake are
now under consideration for the determination of Zn
kinetics in trophoblasts.

Fig. 1. 65 Zn uptake in various trophoblast cells.

References
1) J. Apgar: Ann. Rev. Nutr. 5, 43 (1985)
2) M. Krachler et al.: Eur. J. Clin. Nutr. 53, 486 (1999).
3) R. D. Palmiter and L. Huang: Pflugers Arch. 447, 744(2004).
4) J. Dufner-Beattie et al.: J. Biol. Chem. 278, 50142(2003).
5) J. P. Liuzzi et al.: J. Nutr. 133, 342 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Metal-binding factor responsible for variation of concentration of
trace elements under Zn-deficient condition
M. Yanaga,∗1 T. Ohyama, N. Kinugawa,∗1 T. Ogi,∗1 M. Noguchi,∗2 H. Suganuma,∗1
K. Ishikawa,∗2 R. Hirunuma, K. Takahashi, and S. Enomoto
There are many kinds of trace metal elements, suchas Mn, Fe, Co, Ni, Cu and Zn, which play important roles in living organisms. Among these essential trace elements, Zn is the most important becauseof the variety of its biochemical and physiological actions. Previously, we determined the concentrationsof trace elements in the subcellular fractions of liversof Zn-deﬁcient mice by instrumental neutron activation analysis in order to investigate the inﬂuence of
Zn deﬁciency on the biological behavior of trace elements.1) In this work, the Zn concentration in the
nuclear fraction of Zn-deﬁcient mice, which were fed
with a Zn-deﬁcient diet during the growth period, waslower than that of control mice. Furthermore, in the
supernatant fraction, an increase in the concentrationsof many of the analyzed elements was recognized incomparison with those of the control mice. However,in adult mice, which were fed with a Zn-deﬁcient dietfor 3 weeks from 8 weeks of age, such trend was notobserved, although the Co concentrations in all subcellular fractions were higher than those of control as
seen in growing mice. The change in concentration of
trace elements should be related to the change in theconcentration of metal-binding proteins. Therefore, inthe present work, we attempt to analyze the aﬃnity
between trace elements and Zn-binding proteins which
induce the variation of the concentrations of trace elements under the Zn-deﬁcient condition.
Sixteen 8-week-old male mice of ICR strain were divided into two groups. Eight mice were fed with aZn-deﬁcient diet and the other eight with the control
diet. After three weeks of treatment, their livers were
removed. Eight livers of each group were altogether
homogenized with Tris-HCl buﬀer (25 mM, pH 7.4),
and then, centrifuged for 65 min at 105,000 g to remove
supernatant fractions. Then, an aliquot of the supernatant fraction of each group was divided into 35 fractions by gel ﬁltration chromatography with Sephadex
G-100 using Tris-HCl buﬀer as eluent at a ﬂow rateof 10 ml/h. The concentrations of trace elements andthe protein content in each fraction were determined
by ICP-MS and BCA protein assay method, respectively. The fractions which have high Zn to protein
ratios (marked A, B and C in Fig. 1) were poured
into centrifuge ﬁlter tubes, and then a multitracer solution was added. After centrifugation, the radioac∗1∗2Radiochemistry Research Laboratory, Faculty of Science,
Shizuoka University
Department of Biology and Geosciences, Faculty of Science,
Shizuoka University

Fig. 1. Zinc to protein ratio in each fraction separated bygel ﬁltration chromatography.

tivities in the ﬁlters and ﬁltrates were measured using
HPGe detectors. Radioactivities detected in ﬁlters indicate binding amounts and those in ﬁltrates released
amounts. The distributions of four elements (Se, Zn,
Co, and Mn) are summarized in Fig. 2. As shown in
Fig. 2, the binding amounts of three elements, namely,
Se, Co and Mn, in fraction B of Zn-deﬁcient mice werehigher than those of control mice. This may indicate
the existence of proteins which have great aﬃnity tothese elements in this fraction.

Fig. 2. Aﬃnity between trace elements and proteins in fractions A, B, C in supernatant fraction of livers of mice.
(upper: Zn-deﬁcient mice, lower: control mice)

References
1) T. Ohyama, M. Koike, T. Ogi, Y. Kawamoto, H.
Maetsu, H. Suganuma, M. Noguchi, K. Ishikawa,
R. Hirunuma, S. Enomoto, and M. Yanaga: Proc.
Int. Symp. on Bio-Trace Elements 2002, Joint Symp.
RIKEN and Yamanashi Institute of Environmental Science, Wako and Fuji-yoshida, 2002-10, (RIKEN, 2003)
p. 80.

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RIKEN Accel. Prog. Rep. 37 (2004)

Uptake of metals in cisplatin-resistant lung cancer cell line
T. Suzuki,∗1 K. Ishibashi,∗1 T. Togawa,∗1 S. Ohata,∗1 N. Sato,∗1 K. Nishio,∗2 R. Hirunuma,
H. Haba, S. Enomoto, and S. Tanabe∗1
The molecular mechanism of cisplatin resistance has
been revealed to be “multifunctional”, such as decreased accumulation, increased intracellular detoxification and increased DNA repair ability. Decreased accumulation of cisplatin was observed in non-small celllung cancer (NSCLC) cell lines resistant to cisplatin.
There was a good correlation between the intracellularamount of platinum and sensitivity to cisplatin. Thisevidence suggests that intracellular accumulation is amajor determinant of cisplatin resistance, at least in
NSCLC cell lines.1) Previously, it was reported that
cisplatin enters the cells in an ATP-dependent manner. However, the molecular mechanism of cisplatin
uptake is still unclear. In this study, to investigate thecisplatin uptake mechanisms associated with cisplatin
resistance, we determined the uptakes of various metals in cisplatin-resistant cell lines.
We modified the methods described by Yanagiya
et al.2) and used the human NSCLC cell line, PC-9
and its cisplatin-resistant subline, PC-9/CDDP. Celllines were grown in RPMI1640 supplemented with 10%
FBS. A radioactive multitracer (MT) solution was obtained from a Ag target irradiated in the RIKEN Ring
Cyclotron. Then MT solution was added to the cells
in a serum-free medium and incubated for 2 hr. Afterincubation, the cells were separated from the medium
and the radioactivities were determined using a Ge detector.
Figure 1 shows the uptakes of metals in the cisplatinresistant and parental cell lines exposed to multitracer
for 2 hr. As, Be, Co, Cr, Fe, Mn, Rb, Rh, Ru, Sc, Se,
Sr, V, Y, Zn and Zr were detected in both cell lines.

∗1
∗2

120

Department of Analytical Biochemistry, Meiji Pharmaceutical University
Project Ward, National Cancer Center HospitalFig. 1. Uptakes of metals in lung cancer cell lines.
Cisplatin-resistant cell line (closed column) andparental cell line (open column) were exposed to multitracer for 2 hr.

The uptakes of Mn and Rb in the cisplatin-resistantcell line were higher than in the parental cell line.
However, the uptakes of other metals, particularly Co
were down-regulated in the cisplatin-resistant cell line.
In conclusion, the multitracer technique gave someevidence of decreasing metal uptake in the cisplatinresistant cell line, but further studies are needed todetermine the molecular target for a metal transporter
including a cisplatin transporter.
References
1) T Suzuki et al.: Curr. Drug Metab. 2, 363 (2001).
2) T. Yanagiya et al.: Life Sci. 65, PL177 (1999).

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RIKEN Accel. Prog. Rep. 37 (2004)

Relationship of reactive oxygen species generation with DNA binding
and DNA cleaving activities of metallothioneins I and II
A. Nakayama and S. Enomoto
Copper (Cu) plays a central role in biological systems. Excess Cu, however, is cytotoxic to cells throughhydroxyl radical (•OH) generation by reacting withreactive oxygen species (ROS) such as H2 O2 .1,2) In
the case of excessive Cu accumulation, some metalbinding proteins are induced to protect organs. Amongthem, metallothionein (MT) is one of the most important proteins. Such MTs have four isoforms, MT-I,
MT-II, MT-III, and MT-IV. Among these isoforms,
MT-I and MT-II are expressed ubiquitously in living
systems. On the other hand, Cu accumulates more
highly in the tumor portion of hepatocellular carcinoma.3) Thus, Cu is considered to be associated withtumor development. In contrast, the MT concentration decreases in the tumor portion.3) However, highMT levels are found in the nuclei of malignant cells.4)
The above observations suggest that •OH generation
through the reaction between Cu-MT and ROS induces
DNA cleavage and induces cancer development. Thus,
we investigated whether Cu-MT induces DNA cleavage.
The reactivities of various metal containing MT-I
and -II to superoxide anion (•O2 − ) and H2 O2 were
estimated by the ESR-spin-trapping method and NBTassay. DNA cleaving activity was evaluated by agarose
gel electrophoresis, and interaction between MT and
DNA was estimated by immunoprecipitation.
During the investigation, our results showed that
only Cu-containing MT could react with •O2 − andH2 O2 to generate •OH. Cu-MT-II has higher reactivity to •O2 − than Cu-MT-I, while their reactivities to
H2 O2 appeared to be the same (Figs. 1 and 2). Suchobservations suggested that Cu is closely associatedwith the development and/or progression of cancer because Cu easily reacts with ROS and generates •OH.
We then investigated the DNA cleaving activity ofMTs. Cu-MTs were able to react with pBR322 plasmid DNA regardless of H2 O2 addition. In addition,
the bands containing Cu-MTs and the pBR322 reaction mixture were smeared, and the smeared band disappeared with the addition of SDS, followed by theappearance of a new band that shifted above. This
result suggested that Cu-MTs could form a complex
with pBR322 and cleave DNA strands. The formationof the Cu-MT-pBR322 complex was confirmed by animmunoprecipitation method. The result showed that
pBR322 was coprecipitated with Cu-MTs, suggestingthat Cu-MTs could form a complex with DNA.
Thus, we proposed that an increase in cellular Cu
concentration leads to the formation of Cu-MTs, which
are transported to the nuclei of cancerous cells, where

Fig. 1. Time-dependent •OH generation in the systems ofvarious MTs (225 µg/mL) and H2 O2 (225 µM) at room
temperature.

Fig. 2. Concentration-dependent •O2 − -scavenging activities of SOD and MTs. Each column represents mean
±S.D. of three experiments. Open bar, dashed bar,and closed bar represent the concentrations at 0, 5, and10, in U/mL or µg/mL of SOD or MTs, respectively.

Cu-MTs bind with and then cleave genomic DNA via•OH generation in the vicinity of the DNA. This series of reactions leads to mutation, DNA cleavage and,
finally, cancer.
References
1) H. Sakurai et al.: Biochem. Biophys. Res. Commun.
184, 1393 (1992).
2) A. Nakayama et al.: Biomed. Res. Trace Elem. 13, 78(2002).
3) A. Nakayama et al.: J. Trace Elem. Exp. Med. 15, 31(2002).
4) I. Tashiro-Ito et al.: Liver 17, 300 (1997).

121

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RIKEN Accel. Prog. Rep. 37 (2004)

Investigation of intracellular kinetics of copper in HepG2 cell lines
A. Nakayama, H. Haba, and S. Enomoto
Copper is an essential redox active metal that serves
as a cofactor in various enzymes such as cytochromec oxidase, Cu, Zn superoxide dismutase, ceruloplasmin, and lysyl oxidase.1) An excess of copper, however, induces cytotoxity due to its proclivity to participate in Fenton-like reactions that lead to the generation of highly reactive hydroxyl radicals.2) It has beenreported that copper stimulates the proliferation andmigration of human endothelial cells,3) and also thedevelopment of human cancer.4)
Recently, it has been reported that organisms havedeveloped sophisticated mechanisms of maintaining
the balance between essential and toxic copper levels. Studies of the copper uptake mechanism in human cells have shown that copper is transported by two
high-aﬃnity copper transport proteins, Ctr1 and Ctr3.
Within cells, copper is distributed to speciﬁc subcellular components or proteins by copper chaperones that
include Hah1, which delivers copper to ceruloplasmin,
Cox17, which in turn delivers copper to mitochondrial
cytochrome c oxidase, and CCS, which inserts copper
into Cu, Zn superoxide dismutase.5)
However, the molecular mechanisms underlying thealteration of intracellular copper distribution in diseased cells are poorly understood, because the utilization of radioactive copper isotope is generally diﬃcult.
Thus, we attempted to produce the 67 Cu with thelongest half-life (t1/2 = 61.7 h) among radioactive copper isotopes and to investigate the intracellular copper
kinetics using 67 Cu.
67
Cu was introduced via the 70 Zn(p, α) reaction according to the method reported by Jamriska et al.6)
In brief, an enriched 70 Zn target (80%) was irradiated with a 0.96 µA proton beam (proton energy:
12.8 MeV) for 1 h and 67 Cu was separated from theunreacted target and by-products, 67 Ga and 56 Co, byanion-exchange chromatography. The resulting solution containing 67 Cu was heated to dryness andstocked until use. The dried 67 Cu was completely dissolved in a small amount of 1 M HCl, and diluted with
Dulbecco’s modiﬁed Eagle’s medium (DMEM) supplemented with fetal bovine serum (FBS) at the time ofuse.
We used the human hepatocellular carcinoma cellline, HepG2, and its Cu chaperone knock-down mu-

122tants (Hah1− - and hCCS− -Hep G2) to investigate thekinetics of intracellular copper, because the characteristics of HepG2 cells has been well investigated. Hah1
(human ATX1 (antioxidant protein1) homolog1) is acopper-binding protein and mediates copper homeostasis by donating Cu to the P-type ATPase, ATP7A and
ATP7B which transport Cu to the secretory pathway
for incorporation into secretory proteins and cellular
export.7) hCCS (human copper chaperone for superoxide dismutase) donates Cu to the antioxidant enzyme
containing Cu and Zn, superoxide dismutase.8)
HepG2 cells were grown in DMEM supplemented
with 10% FBS. Then, 100 kBq of 67 Cu was added
to the medium and the cells were incubated for 12 h.
After incubation, the cells were disrupted with lysis
buﬀer (20 mM EDTA, 100 mM NaCl, and 1% SDS in
50 mM Tris-HCl buﬀer, pH 7.5) to obtain cytosols.
The cytosols were analyzed by sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE)
and two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) to evaluate the intracellular kinetics
of copper. By these methods, the proteins are rapidly
separated on the basis of the molecular mass in the caseof SDS-PAGE and on the basis of the isoelectric point
and molecular mass in the case of 2D-PAGE. The radioactive copper was detected using a bioimaging analyzer BAS-2500 (Fuji Photo Film Co., Ltd., Japan).
Although useful information has not yet been obtained at present, important information regarding
copper cytotoxicity as well as the development andprogression of cancer is expected to be obtained in thenear future.
References
1) M. C. Linder: Biochemistry of Copper (Plenum Publishing, New York, 1991).
2) B. Halliwell and J. M. C. Gutteridge: Biochem. J. 219,
1 (1984).
3) G. F. Hu: J. Cell. Biochem. 69, 326 (1998).
4) A. Nakayama et al.: J. Trace Elem. Exp. Med. 15, 31(2002).
5) M. Marjorette et al.: J. Biol. Chem. 275, 33244 (2000).
6) D. J. Jamriska et al.: J. Radioanal. Nucl. Chem. 195,
263 (1995).
7) I. H. Hung et al.: J. Biol. Chem. 273, 1749 (1998).
8) V. C. Cizewski et al.: J. Biol. Chem. 272, 23469 (1997).

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RIKEN Accel. Prog. Rep. 37 (2004)

Comparison of technetium and rhenium uptake rates fromnutrient solution by radish
K. Tagami,∗ S. Uchida,∗ R. Hirunuma, H. Haba, and S. Enomoto
Naturally occurring Re is mostly found in earthsurface materials in trace concentrations. Because of
the chemical similarities of Re and Tc, Re transfer factors from soil to plant can be a Tc surrogate in thenatural environment. Among Tc isotopes, 99 Tc is ofpotential long-term importance in the environment because it has a long half-life of 2.1 × 105 y and is produced in the ﬁssions of 235 U and 239 Pu at relatively
high ratios. Tc is considered to be highly mobile in biogeochemical cycles; indeed, having the highest transfer
factor (TF) in plants among nonnutrient elements1,2)
makes Tc peculiar. However, the TFs of Tc obtained
from recent ﬁeld observations3,4) have been lower thanthose obtained from laboratory studies.1,2) Technetiumchemical forms in the environment presumably play animportant role in determining the fate of Tc in soil toplant systems, although the amount of 99 Tc in the natural environment is determined to be very low.
Although the amount of Re in the environment ishigher than that of 99 Tc, no data are available for terrestrial plant samples. This is primarily due to Re
being one of the rarest elements in the earth’s crustso that its measurement is diﬃcult. We think that aterrestrial plant absorbs Re at a high rate, the same asthat found for Tc. However, the uptake behavior for
Tc and Re was not clariﬁed. Therefore, a radiotracer
experiment using the multitracer technique5) was carried out in this preliminary study. The uptake ratesof Tc and Re by plants were estimated using nutrient
solutions.
Radish seedlings were grown in a nutrient solution
culture. The plants were placed in a greenhouse at
21◦ C and exposed to normal daylight conditions for
30 d. Uniform-size plants were transplanted to 120-mL
plastic vessels each containing 40 or 60 mL of new nutrient solution with multitracers including 95m TcO4 −and 183 ReO4 − . The plants were in contact with thesolution through their ﬁne roots. After 1, 3 and 7 d ofcontact, the plants were carefully removed from the solution. The ﬁne roots were rinsed twice with 300 mL ofdeionized water and gently wiped with paper towels.
The plants were used for another study. The nutrient solutions were passed through 0.22-µm ﬁlters andradioactivities were measured using a Ge detecting system (Seiko EG&G Ortec).
The physicochemical forms of Re in plants are notknown, but there are several reports on those of
Tc.e.g.,6) Technetium is taken up by plants throughtheir roots as TcO4 − , which is the most stable chem∗

Oﬃce of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences

ical form in water under aerobic conditions, and Tc istranslocated to the leaves. Therefore, we expect that
Re could also be taken up as ReO4 − , which is also
the most stable chemical form. After the 1- and 7-dexposure periods, the volume of the nutrient solutionthat remained in the vessels decreased by 8% and 20%,
respectively. The vaporization of the nutrient solution
directly from the vessel would be negligible because it
was covered with a polystyrene foam board, thus the
reduction was due to plant transpiration. The average
concentration ratios for 95m Tc and 183 Re obtained after and before (C/C0 ) the 7-d exposure period in the
nutrient solutions were 1.03 ± 0.03 and 0.88 ± 0.12, respectively. As shown in Fig. 1, the concentration ratios
for the samples determined after the 1-d and 3-d exposure periods were the same, that is, the 95m Tc and183
Re concentrations did not change during the experimental period. In our previous study using a 24-h
exposure period, the same results were obtained forRe.7) The results suggest that Tc and Re uptake rates
by the plants are almost the same as the water uptake
rate.

Fig. 1. Relative concentrations of radionuclides in nutrient
solutions after planting radish for 1, 3 and 7 d.

References
1) R. E. Wildung, T. R. Garland, and D. A. Cataldo:
Health Phys. 32, 314 (1977).
2) F. O. Hoﬀman, C. T. Garten, Jr., J. W. Huckabee, andD. M. Lucas: J. Environ. Qual. 11, 134 (1982).
3) N. Green and B. T. Wilkins: Sci. Total. Environ. 173/
174, 385 (1995).
4) S. Uchida and K. Tagami: Appl. Radiat. Isot. 53, 69(2000).
5) F. Ambe: J. Radioanal. Nucl. Chem. 243, 21 (2000).
6) G. C. Krijger, A. V. Harms, R. Leen, T. G. Verburg,
and B. Wolterbeek: Environ. Exp. Bot. 42, 69 (1999).
7) K. Tagami and S. Uchida: J. Radioanal. Nucl. Chem.
255, 547 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Removal of technetium and other trace elements by bacteria living insurface water covering paddy fields
N. Ishii,∗ K. Tagami,∗ S. Enomoto, and S. Uchida∗
Technetium (99 Tc, half-life: 2.1 × 105 y) is a radioactive contaminant in marine1) and terrestrial environments.2) It is normally present as pertechnetate(TcO4 − ), which is both highly soluble and mobile inthese environments. In addition, this chemical form isavailable to plants. These characteristics of Tc raise
concerns about the transfer of 99 Tc from plants to human beings.
Recently, we have found the formation of insoluble
Tc in surface water covering paddy ﬁelds.3) In ﬂooded
paddy ﬁelds, therefore, the transfer amount of Tc to
paddy rice may be smaller than previously thought.
In this report, we describe the contributions of microorganisms to the insoluble Tc formation in the surface water of paddy ﬁelds. In addition to Tc, traceelements, which behave similar to the Tc, were investigated by the multitracer technique.
A typical Japanese paddy soil, gray lowland soil, wasair-dried and sieved using a 2 mm mesh. The soil sample was ﬂooded for 7 d under a light-dark condition.
After the incubation, only the surface water covering
paddy soil was collected into a new tube, and then thewater sample (pH 6.3) was used without any treatment
following radioactive tracer experiments. A part of thewater sample was treated by fungicide or bactericide
immediately after the water sample collection.3)
A carrier-free 95m Tc solution was prepared from niobium foils irradiated by 40 MeV alpha-particles from acyclotron. A multitracer solution containing radioisotopes of 14 elements (46 Sc, 58 Co, 65 Zn, 75 Se, 83 Rb,
85
Sr, 88 Y, 95 Nb, 139 Ce, 143 Pm, 153 Gd, 173 Lu, 175 Hf,
and 183 Re) was prepared from a thin gold foil irradiated by a heavy-ion beam of 135 MeV nucleon−1 fromthe RIKEN Ring Cyclotron. Both solutions were sterilized by ﬁltration through a 0.2-µm pore-size membrane. That is, all of the radioactive tracers were in
the soluble form when the experiments were started.
The radioactive tracer solutions were added to theuntreated and treated surface water samples and wereincubated for 4 d in the dark. To examine the removal
ratio of the tracers, the water samples with tracers
were passed through a 0.2-µm-pore-size ﬁlter after the
incubation, and the radioactivity of tracers in the ﬁltrate was determined with a Ge detecting system. The
tracers, which removed by the ﬁltration, were deﬁned
as insoluble form. The removal ratio of each tracer
was calculated by the diﬀerence in the radioactivity oftracers between “total” and “ﬁltrate” determinations.
The formation of insoluble Tc in the surface water∗

124

Oﬃce of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences

covering gray lowland soil was determined. After 4 dfrom the addition of soluble 95m TcO4 − , 70.4 ± 4.5% of
the 95m Tc was removed from the surface water sample by the ﬁltration. The data showed the possibility
that soluble TcO4 − changes to insoluble Tc in surface
water of paddy ﬁelds in a short time. The formationof insoluble Tc in the surface water may be one of themechanisms for the Tc accumulation in paddy soils.
In ﬂooded paddy ﬁelds, the accumulation of Tc in
the soils was experimentally demonstrated by Tagami
and Uchida.4) They reported that microorganisms indirectly contributed to the accumulation through theconsumption of molecular oxygen by their respiration.
In addition to the results for the ﬂooded paddy soil
experiments, the contributions of microorganisms on
the insoluble Tc formation in the surface water sample
were determined. When the activity of fungi was inhibited by the addition of fungicide to the surface water,
the removal ratio of Tc was 80.9 ± 0.3%. In contrast,
the addition of bactericide resulted in a decrease in
the removal ratio to 16.6 ± 3.0%. Thus bacteria living in the surface water would cause the insoluble Tc
formation.
Among the 14 elements in the multitracer, 65 Zn and95
Nb showed a similar removal pattern to that of the
95m
Tc. The behavior of both radionuclides in the surface water samples seemed to be controlled by bacteria.
65
Zn was completely removed from both the untreated and fungicide samples. The removal patternof 65 Zn may be explained by the importance of Zn forliving bacteria as a cofactor for numerous enzymes.
Approximately 65% of 95 Nb was removed from theuntreated surface water. The removal ratio increasedslightly by the addition of fungicide. For the bactericide sample, the removal ratio of 95 Nb was approximately 35% of the total 95 Nb added. The Tc insolubilizing bacteria may be used for remediation of thesolution contaminated by both Nb and Tc.
Re and Tc are in the same manganese group. Both
Tc and Re can exist in heptavalent compounds underaerobic conditions. Thus Re would be expected to behave similarly to Tc, but no similar removal patterns
were found between these two elements.
References
1) V. Smith et al.: J. Environ. Radioact. 56, 269 (2001).
2) K. Tagami and S. Uchida: J. Nucl. Radiochem. Sci. 3,
1 (2002).
3) N. Ishii and K. Tagami: Radioisotopes 52, 475 (2003).
4) K. Tagami and S. Uchida: Chemosphere 33, 217 (1996).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Improved separation of Ba and Mg ions in the alkaline earth
group using the centrifugal partition chromatograph
Y. Komatsu,∗1 M. Sekita,∗2 H. Kokusen,∗1 T. Tanemoto,∗1 M. Iiyama,∗1
H. Yamada,∗2 S. Umetani,∗3 and S. Enomoto
The ring cyclotron of the RIKEN Accelerator produces multitracers which include about 50 radioactive
elements useful in the ﬁelds of biotechnology and medical technology, and other applications. The accelerator provides us useful information and the multiple
elements; however, if all elements were to be used in
the tracer technique, some would have a negative effect to the specimen and thus it would become very
diﬃcult to analyze the results. Thus, it is necessary
to chemically separate the desirable elements from theproduced tracer elements. In order to obtain the desirable elements, we applied the centrifugal partition
chromatography (CPC) technique in the solvent extraction system.1) We have been successful in separating potassium (K) and calcium (Ca) ions, which belong
to diﬀerent groups in the periodic table, by means of
this technique, during the course of developing an automation technique for the chemical separation.1) In
this study, we report the results of the separation of
barium (Ba) and magnesium (Mg) ions, which belong
to the same alkaline earth group, by improving this
CPC technique.
In the case of the separation of K and Ca
ions,1) Ca ions can be extracted by adding thenoyltriﬂuoroacetone (TTA) as an extractant and Tri-noctylphosphine oxide (TOPO) as an adductance fromthe aqueous phase to the organic solution, although
K ions pass through the CPC device. After all of theK ions have passed through the CPC device, the Ca ionin the organic phase can be back-extracted to the aqueous phase by adding acid to the solution. Thus the K
and Ca ions can be completely separated.1) However,regarding the separation of Ba and Mg ions, they belong to the same group of the periodic table, and thus it
is expected to be much more diﬃcult to separate themcompletely than the case of K and Ca ions. In order toovercome this diﬃculty, we have focused our attention
on the diﬀerence between the distribution coeﬃcientsof Ba and Mg in the equilibrium;
M2+ + 2HA(o) + 2TOPO(o)+←−−→ MA2 (TOPO)2(o) + 2H

TOPO; however, if acid (proton) is added, the reaction
will go from the right-hand side to the left in Eq. (1).
The distribution coeﬃcients of Ba and Mg diﬀer byalmost 3 orders of magnitude, and thus it is possible
to back-extract Ba ions prior to the back-extraction of
Mg ions by adjusting the pH of the solution.
In the ﬁrst stage, TTA and TOPO were ﬁlled inorganic phase (cyclohexane) with an aqueous solution
containing no metal ions for the stationary (organic)
phase, and then the second aqueous solution containing Ba and Mg ions for the mobile phase was ﬂowed
into the CPC device. By applying centrifugal force
within the CPC device, the Ba and Mg ions in the mobile (aqueous) phase were moved into the stationary
phase by forming a metal complex with TTA-TOPO.
In the next stage, nitric acid solution with controlled
pH was ﬂowed into the mobile phase of the CPC device. Since the pH of the solution in the CPC device was changed from 5.51 to 3.77, the Ba ion forming TTA-TOPO chelates in the stationary phase were
back-extracted to the mobile phase in accordance with
Eq. (1). Due to their having a smaller distribution coeﬃcient than Mg ions, only Ba ions in the mobile phaseare directly moved (back-extracted) into the fraction
collector, while Mg ions were left in the stationary
phase within the CPC device. Every 5 minutes, each
5 cm3 solution was ﬂowed to the sampling tubes in thefraction collector in order to monitor the amount of
Ba and Mg ions during experiments. The measured
amounts of Ba and Mg ions versus the volume of eﬄuent from the CPC device are shown in Fig. 1. One cansee in Fig. 1 that only Ba ions were extracted from the28th (140 ml) to 42nd (210 ml) samplings.
Finally, nitric acid solution with lower pH, that is,stronger acid, was added to the mobile phase at the
47th sampling time (235 ml). Since the pH of the solution in the CPC device was changed to 1.06 at most,(1)

where HA means TTA and ‘o’ denotes the organic
phase. According to Eq. (1), both Ba and Mg ions will
be extracted to the organic phase by adding TTA and
∗1
∗2
∗3

Department of Environmental Systems Engineering, Kanazawa Institute of Technology
Advanced Materials Laboratory, National Institute for Materials Science
Institute for Chemical Research, Kyoto University

Fig. 1. Measured recovery rate of Mg and Ba in percent
versus the eﬄuent volume (cm3 ) from the CPC device.

125

this is a stronger acid region than the preceding stageof 3.77, the Mg ions forming TTA-TOPO chelates inthe stationary phase were then back-extracted into themobile phase similarly to the Ba ions. As can be seen in
Fig. 1, the peak of the percentage of Ba ions appeared
at about the 37th (185 ml) sampling from the beginning of sampling. The Mg ions can be back-extracted
after the extraction of Ba ions was completed from the47th (235 ml) to 55th (275 ml) samplings.

126

It can be concluded that the Ba and Mg ions werecompletely separated and recovered in this improved
method using the CPC device together with the pH
control of the mobile phase solution.
References
1) Y. Komatsu, M. Sekita, R. M. Fujii, H. Yamada,
S. Umetani, and S. Enomoto: RIKEN Accel. Prog. Rep.
36, 207 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Improved extractive separability of metal ionswith sulfonated crown ethers
S. Umetani,∗1 Y. Komatsu,∗2 H. Yamada,∗3 and S. Enomoto
A new type of water-soluble sulfonated crown ether
has been prepared. The extractive separability of lanthanide ions was found to improve by adding the sulfonated crown ethers into the aqueous phase. The
number of water molecules in the ﬁrst coordination
sphere of the central Eu3+ in the complex was determined by a laser-induced luminescence study. In
addition, ﬂuorescence spectra were measured to evaluate the structure of the complexes. The stabilizationof the complexes formed is discussed, taking into account an outer-sphere electrostatic attraction between
the sulfonic acid group and the metal ion. It can also
be expected that the unique extractability is applicable to the separation of multitracers produced by anaccelerator.
A new type of sulfonated crown ether (Fig. 1)
has been synthesized,
3 -sulfobenzo-12-crown-4
(SB12C4), 3 -sulfobenzo-15-crown-5 (SB15C5), 3 sulfobenzo-18-crown-6 (SB18C6), di(3 -sulfo)-dibenzo18-crown-6 (DSDB18C6), di(3 -sulfo)-dibenzo-21crown-7 (DSDB21C7) and di(3 -sulfo)-dibenzo-24crown-8 (DSDB24C8), and the complexation reactionof these crown ethers with lanthanide metal ions inaqueous solution have been investigated. The complex
formation constants, β, of lanthanide ions with the sulfonated crown ethers in aqueous solution were determined by analyzing the distribution of lanthanide ionsin the D2EHPA/cyclohexane solvent extraction systemin the presence and absence of the crown ether. Allof the sulfonated crown ethers show appreciable complexation with lanthanide ions. The present results are
unforeseen and would support the signiﬁcant contribution of the sulfonic acid group to the complexation.
The stability of the resulting complex increases withincreasing in the number of the sulfonic acid groups in
the following order: 18C6 < SB18C6 < DSDB18C6.
It can be considered that the outer-sphere interaction
between the sulfonic acid group and the metal ion cancontribute to the complexation stability. Moreover, formono- and disulfonated crown ether complexes, thestability varies in the order, SB18C6 < SB15C5 <SB12C4 and DSDB18C6 < DSDB21C7 < DSDB24C8.
The stability of the complexes cannot be explained
only on the basis of the concept of a “size-ﬁtting effect”, although it is known that the cavity size of 18C6
(radius, 1.34–1.43 Å) is similar to the ionic size of thelighter lanthanide ions. The log β values are plottedagainst the reciprocal of the ionic radius. It is foundthat β for all of the sulfonated crown ether complexes
with lanthanide ions decreases gradually with increasing the atomic number. This indicates that the cavity
size is not the signiﬁcant factor that governs the complexation behavior with lanthanide ions.
The separation factor between La3+ and Yb3+ in theabsence of any crown ether is 5.34, and this increases
when the crown ethers are added to the aqueous phaseas ion-size selective masking reagents. It is clear thatthe sulfonated crown ethers are much more eﬀective
ion-size selective masking reagents than 18C6. The
best value is given by SB12C4 at 6.63. It is also foundthat the sulfonated crown ethers are eﬀective for theheavier lanthanides.
The hydration number, n◦H2 O , of Eu3+ can be determined from the decay constants of the luminescentexcited state of Eu3+ in the crown ether complex.1) In
general, it could be expected that the number of hydrated water molecules around the central metal ion
decreases with the strong binding of the inner-sphereinteraction-type armed crown ethers to the metal ion.
However, the opposite tendency is seen in the results;
for the complexes of the 18-membered crown ethersand Eu3+ , n◦H2 O increases with increasing number ofsulfonic acid groups (SB18C6 < DSDB18C6); that is,n◦H2 O increases with increasing stability of the complex. The n◦H2 O value also increases in the order,
SB18C6 < SB15C5 < SB12C4, for the monosulfonatedcrown ethers, the same order in which their log β values
increase. The n◦H2 O value for the disulfonated crownether complex slightly increases with the cavity size.
The unusual stability of lanthanide ions with the sulfonated crown ethers which have one or two bindingsites is dominated by two primary factors: (1) iondipole interaction between the metal ion and thecrown ether donating oxygens and (2) the long-range
interaction between the metal ion and the sulfonic acidgroup. These synergistic eﬀects should be considered.

Fig. 1. Sulfonated crown ethers.
∗1
∗2
∗3

Institute for Chemical Research, Kyoto University
Faculty of Engineering, Kanazawa Institute of Technology
Advanced Materials Laboratory, National Institute for Material Science

References
1) T. Kimura and G. R. Choppin: J. Alloys Compd. 213/
214, 313 (1994).

127

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RIKEN Accel. Prog. Rep. 37 (2004)

Study on Re and Os removal from seawater to sediments using
multitracer technique and X-ray absorption near-edge structure
M. Ito,∗ Y. Takahashi,∗ H. Haba, S. Enomoto, and H. Shimizu∗
Rhenium and Os abundances have been reported
to be approximately 8 pg/g1) and 0.01 pg/g,2) respectively, in seawater and 20–190 ng/g and 0.2–0.7 ng/g,
respectively, in black shale,3) with 187 Re/188 Os ratios of approximately 4300 in seawater and 500–1500
in black shale. These data indicate the Re/Os fractionation during Re and Os removal from seawater toblack shale. Here, the sorption experiments of Re and
Os on sediments from seawater was conducted using
the radioactive nuclides 183 Re and 185 Os in a multitracer. Rhenium and Os species incorporated in thesediments were studied using Re LIII -edge and Os LIII edge XAFS.
The nuclides 183 Re and 185 Os were obtained from
Au targets irradiated with 12 C or 14 N ions using the
RIKEN Ring Cyclotron. The Au target was dissolved
with aqua regia, which was evaporated at 60–100◦ C for
two hours under vacuum. Most of Os was separated
into distilled solution. Rhenium mainly remained in
the residue after the evaporation for Os separation.
Gold, matrix in the residue, was extracted into ethyl
acetate. Rhenium remaining in the aqueous phase during the solvent extraction was separated from otherFig. 1. Time dependence of Eh and fraction of each element remaining in synthetic seawater in the presence ofTokyo Bay sediments under mildly oxic condition. Synthetic seawater: 12.0 g; Tokyo Bay Sediments: 3.00 g.
∗

128

Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University

Fig. 2. Time dependence of Eh and fraction of each element remaining in synthetic seawater in the presenceof Tokyo Bay sediments free from organic matter. The
organic matter was removed by burning at 980◦ C. Synthetic seawater: 12.0 g; Tokyo Bay Sediments free fromorganic matter: 3.00 g.

Fig. 3. Time dependence of Eh and fraction of each element remaining in synthetic seawater in the presenceof Tokyo Bay sediments under reducing condition. Synthetic seawater: 12.0 g; Tokyo Bay Sediments free fromorganic matter: 3.00 g.

cations using a cation-exchange resin, where Re is notadsorbed on the resin. The Os and Re fractions weremixed prior to their use in the sorption experiments.
In the sorption experiments on Tokyo Bay sediments(total organic carbon content: 2.07%) from synthetic
seawater under diﬀerent Eh conditions, the removal behavior of Os from seawater into sediments was shown
to be diﬀerent from that of Re. Osmium was removed into sediments even under mildly oxic conditions (Eh = 300 mV and pH 7.5) (Fig. 1), but not removed into sediments free from organic carbon (Fig. 2).
This suggests that Os in seawater directly interacts
with organic matter in sediments. On the other hand,Re was incorporated into the sediments only understrongly anoxic conditions produced by the addition of
glucose (Fig. 3). This suggests that removal of Re into
sediments depends on anoxic conditions rather thanthe eﬀect of organic matter.
Speciation of Re and Os added into the Tokyo Bay
sediments under anoxic conditions was conducted by

XAFS. XANES spectra suggested that the oxidation
number of Os sorbed on the sediments was trivalent,even though Os was doped into synthetic seawater as
Os(IV)Cl6 2− and Os(VIII)O4 . Since octavalent Os has
been considered as the main dissolved species in theocean,2) the reductive reaction of Os can be an important factor in the accumulation of Os in anoxic sediments. This is consistent with the labile characterof trivalent cation which is readily sorbed on various
metal oxides and complexed with natural organic polyacids.
References
1) D. Colodner, J. Sachs, G. Ravizza, K. K. Turekian, J.
Edmond, and E. Boyle: Earth Planet. Sci. Lett. 117,
205 (1993).
2) S. Levasseur, J. Birck, and C. F. Allegre: Science 282,
272 (1998).
3) G. Ravizza, K. K. Turekian, and B. J. Hay: Geochim.
Cosmochim. Acta 55, 3741 (1991).

129

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Anion-exchange behavior of element 104, rutherfordium
H. Haba, K. Tsukada,∗1 M. Asai,∗1 A. Toyoshima,∗1,∗2 K. Akiyama,∗1 I. Nishinaka,∗1 M. Hirata,∗1 T. Yaita,∗1
S. Ichikawa,∗1 Y. Nagame,∗1 K. Yasuda,∗1 Y. Miyamoto,∗1 T. Kaneko,∗1 S. Goto,∗3 S. Ono,∗3 T. Hirai,∗3
H. Kudo,∗3 M. Shigekawa,∗2 A. Shinohara,∗2 Y. Oura,∗4 H. Nakahara,∗4 K. Sueki,∗5 H. Kikunaga,∗6
N. Kinoshita,∗6 N. Tsuruga,∗6 A. Yokoyama,∗6 M. Sakama,∗7 S. Enomoto, M. Schädel,∗8
W. Brüchle,∗8 and J. V. Kratz∗9
The increasingly strong relativistic eﬀect on thevalence electrons of transactinide elements is expected to induce deviations in chemical properties
from the periodicity based on lighter homologues in
the periodic table. The ﬁrst transactinide element,
rutherfordium (Rf), is considered to be a group-4
member with the ground-state electronic conﬁguration of [Rn]5f 14 6d2 7s2 , though relativistic calculations
have predicted diﬀerent conﬁgurations such as 6d2 7s2 ,7s2 7p2 , and 6d7s2 7p.1) The nuclide 261 Rf, which has
a half-life of 78 s,2) can be used for chemical studies
of Rf. The production rate of 261 Rf is of the order of
one atom per minute under typical experimental conditions, which forces us to perform rapid and repetitive chromatographic experiments with single atoms.
Previously, we investigated the anion-exchange behavior of Rf together with those of lighter homologues ofgroup-4 elements Zr and Hf in 4.0–11.5 M HCl and
8.0 M HNO3 solutions.3) It was found that the adsorption trends of Rf in HCl and HNO3 are very similar
to those of Zr and Hf, indicating that Rf is a typicalgroup-4 member. Reported in this paper is our recent
result of the successive anion-exchange study of Rf in
1.9–13.9 M HF solutions.
The carrier-free radiotracers of 89 Zr and 175 Hf
were produced in the 89 Y(p, n) and 175 Lu(p, n) reactions, respectively, using a 14-MeV proton beamfrom the RIKEN K70 AVF Cyclotron. The anionexchange resin used was MCI GEL CA08Y, suppliedby Mitsubishi Chemical Corporation, a strongly basic quaternary-amine polymer with the particle size of
22 ± 2 µm. 10–200 mg of CA08Y and 3 mL of 0.97–
26.4 M HF solution containing 50 µL of the tracer solution were placed in a polypropylene tube and shaken
for 100 min at 20◦ C. After centrifugation, 1 mL of theaqueous phase was pipetted into a polyethylene tube
and subjected to γ-ray spectrometry using a Ge detector. As a standard sample, 50 µL of the tracer solution
was diluted to 1 mL of 0.1 M HF in another polyethylene tube. The distribution coeﬃcient Kd in unit of
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8
∗9

130

Advanced Science Research Center, Japan Atomic Energy
Research Institute
Graduate School of Science, Osaka University
Faculty of Science, Niigata University
Graduate School of Science, Tokyo Metropolitan University
Department of Chemistry, University of Tsukuba
Faculty of Science, Kanazawa University
School of Health Sciences, University of Tokushima
Gesellschaft für Schwerionenforschung, Germany
Institut für Kernchemie, Universität Mainz, GermanymL g−1 was obtained using Kd = Ar Vs /As Wr , where
Ar and As are the radioactivities in the resin and thesolution, respectively, and Vs is the volume of the acidsolution and Wr is the mass of the dry resin.
Isotope 261 Rf was produced in the 248 Cm(18 O, 5n)reaction using a 94-MeV 18 O beam delivered from the
JAERI tandem accelerator. A 248 Cm target of 610 µg
cm−2 thickness was prepared by electrodeposition onto
a 2.4 mg cm−2 thick Be foil. Beam intensity was approximately 0.3 particle µA. Reaction products recoiling out of the target were transported by a He/KCl
gas-jet system to the Automated Ion-exchange separation apparatus coupled with the Detection system for
Alpha spectroscopy (AIDA).3,4) Two diﬀerent microcolumns, 1.6 i.d. × 7.0 mm and 1.0 i.d. × 3.5 mm, were
ﬁlled with the CA08Y resin. After the deposition for
125 s, Rf was dissolved in 240 (260)a) µL of 13.9, 11.6,
7.7, 5.8, 4.8, and 3.9 (3.0, 2.4, and 1.9) M HF and fed
into the column at a ﬂow rate of 0.74 (1.0) mL min−1 .
The eﬄuent was collected on a Ta dish as Fraction 1and evaporated to dryness using hot He gas and a halogen heat lamp. The remaining Rf in the column was
eluted with 210 (200) µL of 4.0 M HCl. This eﬄuent
was collected on another Ta dish and evaporated todryness as Fraction 2. The pair of Ta dishes, Fractions 1 and 2, was automatically transferred to an
α spectrometry station equipped with eight 600 mm2
PIPS detectors. All events were registered event by
event. To investigate the on-line anion-exchange behavior of Zr and Hf, isotopes 85 Zr and 169 Hf were
simultaneously produced in the nat Ge(18 O, xn) andnat
Gd(18 O, xn) reactions, respectively. The anionexchange experiments were performed with AIDA at
3.9–17.4 M HF under the same experimental conditions
as those with 261 Rf. The eﬄuents were assayed by γray spectrometry with Ge detectors.
From ion-exchange experiments performed 849, 631,
322, 271, 179, 532, 465, 501, and 476 times at 13.9,
11.6, 7.7, 5.8, 4.8, 3.9, 3.0, 2.4, and 1.9 M HF, respectively, a total of 266 α events from 78-s 261 Rf(8.28 MeV)2) and its daughter 25-s 257 No (8.22, 8.27,
and 8.32 MeV)2) were registered in the energy range of
8.00–8.36 MeV, including 25-time-correlated α pairs.
From the activities A1 and A2 observed in Fractions 1
and 2, respectively, the percent adsorption (%ads) on
CA08Y was evaluated using %ads = 100 A2 /(A1 +A2 ).
a)

The values given in parenthesis refer to the condition whenthe 1.0 i.d. × 3.5 mm column was used.

Then, the %ads values of Rf were transformed into Kd
values based on the smooth relationship between the%ads values of 85 Zr and 169 Hf and the Kd values of89
Zr and 175 Hf.5)
In Fig. 1, the variation of the Kd value of Rf is shownby closed squares as a function of HF concentration,[HF], together with those of 89 Zr and 175 Hf shown by
open squares and open circles, respectively. As shownin Fig. 1, the Kd values of Zr and Hf are identical witheach other and both decrease with an increase of [HF].

A linear relationship with a slope of −3.0 ± 0.1 wasfound in the log Kd -log [HF] plot shown by a dashedline. As HF is a weak acid, equilibrations among HF,
H+ , F− , and HF2 − in the solution are established following the two chemical relations: H+ + F− ↔ HF and
HF + F− ↔ HF2 − .6) Above 1 M, [HF2 − ] is more than
one order of magnitude higher than [F− ], and the decrease of Kd with [HF] is explained as displacementof the metal complexes from the binding sites of theresin with HF2 − . Although the Kd values of Rf also decrease linearly with [HF], they are apparently smaller
than those of Zr and Hf. Also noted is that the slope of−2.0±0.3 of the plot of log Kd vs. log [HF] for Rf diﬀers
from that for Zr and Hf, implying that diﬀerent anionicspecies are formed. The relativistic molecular density
functional calculations on the ﬂuoride complexes of Rf,
Zr, and Hf are under study in our group to interpretthe remarkable diﬀerence in the anion-exchange behavior and to discuss the inﬂuence of relativistic eﬀects on
the ﬂuoride complexation of Rf.
References

Fig. 1. Variations of the distribution coeﬃcient values (Kd )of 261 Rf, 89 Zr, and 175 Hf on CA08Y as a function of HF
concentration, [HF]. Linear relationships with slopes−2.0 ± 0.3 for Rf and −3.0 ± 0.1 for Zr and Hf in the log
Kd -log [HF] plot are indicated by the solid and dottedlines, respectively.

1) M. Schädel (ed.): The Chemistry of Superheavy Elements (Kluwer Academic Publishers, Dordrecht, 2003).
2) R. B. Firestone and V. S. Shirley: Table of Isotopes, 8thed. (John Wiley & Sons, New York, 1996).
3) H. Haba et al.: J. Nucl. Radiochem. Sci. 3, 143 (2002).
4) Y. Nagame et al.: Czech. J. Phys. Suppl. A 53, A299
(2003).
5) H. Haba et al.: J. Am. Chem. Soc., in press.
6) P. M. Plaisance and R. Guillaumont: Radiochim. Acta
12, 32 (1969).

131

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RIKEN Accel. Prog. Rep. 37 (2004)

Performance of a gas-jet-coupled multitarget system
for multitracer production
H. Haba, K. Igarashi, D. Kaji,∗ R. Hirunuma, and S. Enomoto
Since 1991,1) the RIKEN multitracer technique has
been successfully applied in investigations of the behavior of various elements in the ﬁelds of chemistry,
biology, medicine, engineering, and environmental science. By using the falling ball system,1) radionuclides
of a large number of elements were simultaneously produced from metallic targets such as Ti, Ag, and Au irradiated with a 135 MeV/nucl. 14 N (or 12 C, 16 O) beamfrom the RIKEN Ring Cyclotron (RRC). After theirradiation, these radionuclides were chemically separated from the target material,1,2) and then carrierfree and salt-free multitracer solutions were applied tovarious experiments.
Recently, we have installed a gas-jet-coupled multitarget system on the E3b beam line of RRC as analternative to the falling ball system. A schematic of
this system is shown in Fig. 1. In the ﬁrst chamber,the 135 MeV/nucl. 14 N (or 12 C, 16 O) beam from RRC
passes through a HAVAR vacuum window of 6 µm
thickness, and enters 30 multitarget of about 1 µm inthickness with 10 mm spacings. The recoiling multitracers are stopped in He gas, attached to aerosols suchas NaCl, KCl, and C, and are continuously transported
through a Teﬂon capillary to a chemistry room, where
the multitracers are collected on a glass ﬁlter. Then,the multitracer solutions are obtained simply by wash-

ing the ﬁlter with a suitable solution. Lastly, the 14 N
beam enters the thick metallic targets such as Ti, Ag,
and Au, which are about 200 µm in thickness, in thesecond chamber. After the irradiation, the long-lived
multitracers were chemically separated using the sameprocedure as applied previously.1,2)
Advantages of the present system are as follows. (1)The multitracers are separated from the target material without chemical separation and transported tothe chemistry room within a few seconds. Thus, radionuclides with short half-lives of less than 1 min areavailable for tracer experiments. (2) The targets withvarious chemical compositions are prepared by electrodeposition or vacuum-evaporation techniques. The
composition of the radionuclides in the multitracer canbe optimized by changing the target material and its
array. (3) The radionuclides of interest can be easily
concentrated by using a liquid chromatography apparatus based on ion exchange or solvent extraction. (4)All of the targets are continuously cooled with He gas
during the irradiation. Thus, the beam intensity of〜1 pµA is acceptable, though the maximum in thefalling ball system was approximately 0.1 pµA due tothe irradiation in a vacuum chamber.
The performance of the gas-jet-coupled multitarget system was investigated using the 30 multiple

Fig. 1. Schematic of the gas-jet-coupled multitarget system for multitracer production.
∗

132

Center for Nuclear Study, University of Tokyonat

Cu target of 2 µm in thickness irradiated with the
135 MeV/nucl. 14 N beam of 50 pnA in intensity. The
multitracers recoiling out of the target were stopped
in He gas (〜80 kPa), attached to KCl aerosols generated by sublimation of the KCl powder at 640◦ C,
and continuously transported through a Teﬂon capillary (2.0 mm i.d., 10 m long) to the Hot Laboratory
just beneath the E3 irradiation room. The aerosols
were collected on a glass ﬁlter ADVANTEC GB-100R
for 15 min. The ﬂow rate of the He carrier gas was
2.0 L min−1 . In the same irradiation, one Cu foil of
2 µm thickness and 15×15 mm2 size sandwiched by one
pair of Kapton foils of 50 µm thickness and 20×20 mm2
size, which collected the recoiling nuclei from the target, was irradiated in the second chamber. After theirradiation, the glass ﬁlter, the Cu target, and the Kapton catchers were subjected to γ-ray spectrometry witha Ge detector.
The radioactivities of the 52 nuclides of 18 elements produced from nat Cu were identiﬁed in theglass ﬁlter. This number of nuclides is quite large
as compared with the 11 nuclides of 10 elements produced from nat Cu by the falling ball system.3) The
radionuclides with short half-lives (T1/2 < 〜1 min)such as 25 Na (59.1 s), 35 P (47.3 s), 40 Cl (1.35 min),and 58m Mn (65.3 s) were found to be applicable fortracer experiments. On the other hand, the 28 radionuclides varying from 61 Cu to 24 Na were identiﬁed in both the Cu target and the Kapton catchers. For these nuclides, the recoil eﬃciency εr and thegas-jet eﬃciency εg were calculated according to theequations εr = 100NKapton /(NKapton + NCu target ) andεg = 100NGlass filter /30NKapton , N being the numberof atoms, respectively. The εr and εg values are shownin Fig. 2 as a function of the mass diﬀerence (∆A)
between a product and a target (A = 65), and are
represented by open and closed circles, respectively.
The εr values increase smoothly with an increase of∆A, reﬂecting both the increasing kinetic energy andthe decreasing stopping power of Cu for the productnuclei. The εg values are about 30% for the productnuclei with ∆A = 〜5 and decrease to about 10% withan increase of ∆A. It is interesting to note that the εgFig. 2. Variation of the recoil eﬃciency εr and the gas-jet
eﬃciency εg as a function of the mass diﬀerence ∆A.

values of chlorine isotopes of 39 Cl, 38 Cl, and 34m Cl areappear to be smaller than the systematic trend fromother products. The hot chlorine atom may interact
with Cl atoms of the aerosol and form a gaseous Cl2 ,which cannot be collected on the glass ﬁlter.
In separate experiments, the long-lived multitracers were produced from 200-µm-thick nat Ag and 300µm-thick 197 Au targets using the 135 MeV/nucl. 14 N
beam with the maximum intensity of 0.6 pµA, which
was more than six times the limit of the falling ball system. Thus, the production eﬃciency of the multitracer
was markedly enhanced. The entire target chamber
was surrounded with 150-mm-thick iron and 300-mmthick concrete blocks in order to shield the neutronsand γ-rays from the targets and the beam dump. The
radiation dose in the E3 room during the multitracer
production was decreased to about one fourth of thatof the previous system.
References
1) S. Ambe et al.: Chem. Lett. 1991, 149.
2) S. Ambe: RIKEN Rev., No. 13, 3 (1996).
3) S. Ambe et al.: Anal. Sci. 7, Suppl., 317 (1991).

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RIKEN Accel. Prog. Rep. 37 (2004)

Development of a new target system for online
multitracer preparation
M. Yatsukawa,∗1 Y. Kasamatsu,∗1 H. Kikunaga,∗2 N. Kinoshita,∗2 S. Shibusawa,∗3 T. Hashimoto,∗2 M. Arai,∗3
K. Ninomiya,∗1 A. Yokoyama,∗3 W. Sato,∗1 N. Takahashi,∗1 S. Enomoto, S. Shibata,∗4 and A. Shinohara∗1
The multitracer technique enables simultaneous
tracing of a number of elements in biological and chemical systems. This technique is therefore useful in various fields such as medicine, pharmacology, biology,
chemistry, and environmental science. For the supply
of a multitracer solution, however, chemical separation must be performed after several-day cooling of
the target irradiated with high-energy heavy ions. For
the rapid preparation of a wider variety of elements,
we have developed a new target system for the online
preparation of multitracer elements.
On the basis of our previous data for the yield andrecoil property,1,2) we have designed a special irradiation apparatus shown in Fig. 1. The target foil isplaced in the chamber filled with a catcher solution.
While the target is irradiated with a heavy-ion beam,
radioactive nuclides recoil out of the foil. Then therecoils are caught in the solution to be transported tothe solution reservoir.
Test experiments with the target fragmentation reaction were performed using HIMAC (Heavy Ion Medical Accelerator in Chiba) at National Institute of Radiological Sciences with a 12 C beam (290 MeV/nucleon).
Five sheets of Nb foils of 11.3 mg/cm2 thickness were
employed as the target and spaced at intervals of
0.4 mm. Ion exchange water and pH5 and pH3 acetic
acid solutions were used as catcher solvents to investigate the pH dependence of the yield. During theirradiation for 20 minutes, each of the solvents wascirculated in the chamber for the homogenization of
the solutions. After the irradiation, we immediately
recovered the multitracer solutions and measured theradioactivities in them with a Ge detector placed awayfrom the irradiation room.

Table 1 shows the yields of detected elements, expressed in the form of relative values to those for the
stacked catcher foils.1) We found that the yields of therecoil products from the target foils tend to increase
with decreasing pH of the solution: water < pH5 <pH3 acetic acid solutions. The yields of the detected
elements are plotted in Fig. 2 as a function of the solubility of each metal-hydroxide solution.3),a) We cansee a correlation between the yields and the solubilities of the metal hydroxides. In order to achieve reproducibility, further experiments are to be carried out at
the RIKEN Accelerator Research Facility.
Table 1. Elemental yields of the recoil products recoveredby solution catchers. The average values are shown for
the elements corresponding to two or more nuclides.

Fig. 2. Correlation of the elemental yields of the recoil
products with the solubilities of the metal hydroxides.

References
Fig. 1. New target system for online multitracer production.
∗1
∗2
∗3
∗4

134

Graduate School of Science, Osaka University
Graduate School of Natural Science and Technology,
Kanazawa University
Faculty of Science, Kanazawa University
National Institute of Radiological Sciences

1) A. Yokoyama et al.: Radiochim. Acta 89, 703 (2001).
2) A. Yokoyama et al.: HIMAC-042, 95 (2001).
3) Kagaku Binran, 4th edition edited by M. Oki et al. (The
Chemical Society of Japan, Tokyo, 1993), p. II–161.
a)

For the solubility products of the metal hydroxides, the solubilities were calculated for each pH of the solutions using
literature values adopted in Ref. 3.

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RIKEN Accel. Prog. Rep. 37 (2004)

Preliminary study on olfactory transport of a multitracer
produced in Ti target
Y. Kanayama,∗ H. Haba, R. Hirunuma, S. Enomoto, and R. Amano∗
Olfactory receptor neurons are in contact with theenvironment via the olfactory epithelium, moreover,the neurons connect with the olfactory bulb via axons.
The axonal transport provides a pathway by whichsome proteins, viruses, and rarely metals directly enter
the brain. Little information is available on the transport of metal ions via the olfactory pathway, although
Mn2+ , which has a similar property to Ca2+ was reported to be accumulated in the olfactory bulb via thispathway.1)
In our previous studies, 24 hours after intranasal
administration, we noted the anomalously high accumulation of 83 Rb+ in the brain among 16 radionuclides in the multitracer produced in the Ag target.2)
Furthermore, we demonstrated that 86 Rb+ , 137 Cs+ ,and 201 Tl+ , which are K+ -mimic ions, are unilaterally accumulated and transported to the olfactory
bulb and cortices after unilateral intranasal administration.3) These ﬁndings clearly indicate that theseions are transported via the olfactory pathway. Interestingly, it seems that the speed of transport diﬀers depending on the ion, for example Rb+ transport is fasterthan Mn2+ transport. However, underlying mechanisms and physiological roles of the axonal transportof K+ and Ca2+ are poorly understood. In this research, we attempted to apply a multitracer producedin Ti target, which enables simultaneous tracing of
24
Na+ , 28 Mg2+ , 43 K+ , and 47 Ca2+ , for clarifying theirolfactory transport.
A multitracer was obtained from a Ti target of 2 µm
thickness irradiated with a 135 MeV/nucl. 14 N beamof 300 pnA for 3 hours using RIKEN Ring Cyclotron.
The multitracer solution for administration contained
radionuclides of 24 Na+ , 28 Mg2+ , 43 K+ , and 47 Ca2+ inthe physiological saline solution. Eight-week-old male
ICR mice were subjected to either intranasal (IN) or
intravenous (IV) administration of the multitracer solution. In the IN-group, the solution was administered only into the right nostril to clarify whether theroute of tracer delivery is via the olfactory pathway.
Six hours after the administration, the blood (BL),liver (LI), and brain were separately obtained. The
brain was then divided into the right and left sides,
and further divided into three regions which were theolfactory bulb (OB), the forebrain including the olfactory cortex (FB), and all the remaining brain (RB).
Activities were measured by γ-ray spectrometry using
pure Ge detectors and the uptake rates were determined in terms of the administered dose per wet weight∗

School of Health Sciences, Faculty of Medicine, Kanazawa
University(%dose/g).
Figure 1 shows the 24 Na+ , 28 Mg2+ , and 43 K+ uptake
rates. No signiﬁcant diﬀerences was observed between
the right and left sides of the three brain regions. This
indicates that the multitracer solution can penetrate
the nasal septum. The 43 K+ uptake rates in the ROB
and LOB in the IN-group seemed to be higher thanin the IV-group, and agreed with our previous dataof the K+ -mimic ions.3) Moreover, a similar tendency
was observed in the 28 Mg2+ uptake rates. The results
indicate that Mg2+ and K+ are directly transported
via the olfactory pathway. In contrast, 24 Na+ uptake
rates were low, and there was no signiﬁcant diﬀerence
between IN- and IV-groups. As for 47 Ca2+ , activities were not detected except in blood samples of the
IV-group (0.42 ± 0.09%dose/g).
Novel knowledge on the ion transportation via theolfactory pathway strongly indicates the usefulness ofthe multitracer produced in the Ti target for investigating the biobehavior of Na+ , K+ , and Mg2+ simultaneously.

Fig. 1. Uptake rates (%dose/g) of 24 Na+ , 28 Mg2+ , and43 +K in the blood, liver, and brain regions following
intranasal (IN) or intravenous (IV) administration ofa multitracer. In IN administration the multitracer was
instilled only into the right nostrils of the mice. OB: olfactory bulb; FB: forebrain; RB: remaining brain; BL:blood; LI: liver; R: right side; L: left side. The errors
are standard deviations for three samples. Significancelevels: §1 p < 0.05, §2 p < 0.01, IN vs. IV.

References
1) S. Durston et al.: NeuroImage 16, 449 (2002).
2) Y. Kanayama et al.: RIKEN Accel. Prog. Rep. 36, 123(2003).
3) Y. Kanayama et al.: Eur. J. Nucl. Med. Mol. Imaging.
30 suppl. 2, S296 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Multitracer imaging in plants by GREI system
S. Motomura, R. Hirunuma, K. Igarashi, H. Haba, H. Takeichi, M. Kibe,∗1 Y. Gono, A. Odahara,∗2
S. Enomoto, and Y. Yano
We have instrumented a prototype of the γ-ray
emission imaging1) (GREI) system. The GREI system makes it possible to visualize the distribution of
mixed radioisotopes (RIs) simultaneously and nondestructively. On the other hand, the RI Beam Factory(RIBF) project is in progress at RIKEN Accelerator
Research Facility. The RIBF provides a great variety
of RIs in the form of accelerated heavy-ion beams. The
GREI system, combined with the RIBF, will give rise
to a new methodology in biology, nuclear medicine,and so forth.
In order to prove the feasibility of the GREI system
by examples, we have performed experiments to visualize the RIs distributed in soybean samples. In thisreport, we present the results for two samples, SB-1
and SB-2 (Fig. 1), administered with the following RIs:
(1) 40-kBq 65 Zn; (2) 630-kBq 137 Cs, 140-kBq 59 Fe and
50-kBq 65 Zn. The measurements of SB-1 and SB-2
were carried out for 113 and 25 hours, respectively.
Each sample was ﬁxed on a plane 1.5 cm apart fromthe center of the front detector.
The sections of the cones deﬁned for each event wereaccumulated on the plane where the sample was ﬁxed,
in order to obtain the two-dimensional image of the
RIs. This image is called a simple back-projection(SBP). The SBP image for SB-1 is shown in Fig. 2 (a).
The smeared image in the SBP was deconvoluted assuming that the point-spread function (PSF) was shiftinvariant. We call the resultant image DABP (deconvolution after back-projection). The DABP image forSB-1 is shown in Fig. 2 (b).
The γ-ray spectrum measured by the GREI system
for SB-2 is shown in Fig. 3 (a). The peaks of the intrinsic γ rays for each RI are clearly separated in the spec-

Fig. 2. Results of imaging 65 Zn in SB-1. (a) SBP image.
(b) DABP image.

Fig. 3. Results of imaging the RIs in SB-2. (a) The
γ-ray spectrum measured by the GREI system.
(b)–(d) DABP images of each RI.

trum. By setting energy gates at each peak, DABP
images were obtained for each RI (Fig. 3 (b)–(d)). It
was successfully observed that each RI has a diﬀerent
distribution in SB-2.
The development of the GREI system is still inprogress in order to improve the position resolution
and the sensitivity, including an accurate treatment of
the PSF, which is signiﬁcantly dependent on the position in reality.
Fig. 1. Photographs of soybean plants administered with
RIs. (a) SB-1. (b) SB-2.
∗1
∗2

136

Graduate School of Science, Kyushu University
Nishinippon Institute of Technology

References
1) S. Motomura and S. Enomoto: J. Clin. Exper. Med.
205, 884 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Implementation of GREI system with DOI measurement capability
S. Motomura, M. Kibe,∗1 Y. Gono, A. Odahara,∗2 H. Takeichi, S. Enomoto, and Y. Yano
The Compton camera proposed for γ-ray emission
imaging1,2) (GREI) consists of two sets of double-sided
orthogonal-strip (DSOS) germanium (Ge) detectors
which are arranged in parallel. The dimensions of theDSOS Ge detectors are 39 mm × 39 mm × 10 mm and
39 mm × 39 mm × 20 mm for the front and rear detectors, respectively. The strip pitch is 3 mm for both detectors. The transverse position of a γ-ray interaction
point (TOI) in the DSOS Ge detector is determined by
a combination of the anode and cathode strips with theaccuracy given by the width of the strip. It is also possible to determine the depth of the γ-ray interaction
point (DOI) by taking into account the time diﬀerence
between the signals from the anode and cathode.3,4)
We have fabricated a prototype of the GREI system
which is able to utilize the DOI information. Timing
ﬁlter ampliﬁers (TFAs) and constant fraction discriminators (CFDs) were employed in order to generate thetiming pulses from each output of the preampliﬁers.
The time constants of the TFAs were 500 ns and 60 ns
for diﬀerentiation and integration, respectively. The
fraction for the CFDs was 0.5. The delay time for
the CFDs was 50 ns, which was the upper limit of themodules.
In order to check the performance of the system, we
measured γ rays from a point source of 152 Eu placed in
front of the Compton camera. Histograms of the time
diﬀerence between the signals from the anode and thecathode were constructed for some intrinsic γ rays of152
Eu by setting energy gates at each peak. A result for
the energy gate at 122 keV is shown in Fig. 1. The origin of the time diﬀerence was set where is maximum.
As shown in Fig. 1, the dependence of the count ontime diﬀerence has good agreement with the attenuation curve of 122-keV γ ray in Ge crystal assumingthat the time diﬀerences of 0 ns and 140 ns correspondto the DOI values of 0 cm and 1 cm, respectively. Thisimplies that DOI can be measured directly from thetime diﬀerence. In addition, it was found that therange of the time diﬀerence is constant even when the
γ-ray energy is changed. Because of this fact, the algorithm for DOI measurement has become very simple.
This is an advantage of using CFD.
The eﬀect of DOI measurement was investigated byobtaining simple back-projection (SBP) images of apoint source of 65 Zn, which emits 1115-keV γ rays.
The source was placed 4.9 cm away from the centerof the front detector. Two-dimensional (2D) SBP images were obtained by accumulating the sections of thecones deﬁned event by event on the plane where the∗1∗2Graduate School of Science, Kyushu University
Nishinippon Institute of Technology

Fig. 1. Histogram of the time diﬀerence between the signals
from the anode and cathode strips. The energy gate wasset at the 122-keV γ-ray peak. The time diﬀerences of
0 ns and 140 ns are assumed to correspond to the DOI
values of 0 cm and 1 cm, respectively.

source was located. The full-width at half maximum(FWHM) of the 2D-SBP was 8 mm when DOIs were
ﬁxed at the half depth of each detector. On the other
hand, the FWHM of the 2D-SBP was 6 mm when DOIs
were measured from the time diﬀerence.
The eﬀect of DOI measurement becomes more significant when TOI is measured more accurately. 2D-SBP
images of the 65 Zn point source under the same conditions as in the above experiment were obtained bysimulation using GEANT when: (1) TOIs were ﬁxed
at the center of each strip and (2) TOIs were assumed
to be measured with an accuracy of 0.2 mm in FWHM.
When the TOIs were ﬁxed, the FWHMs of the 2D-SBP
images were 8 and 6 mm for the ﬁxed and measured
DOIs, respectively. These values agreed well with theresults of the experiment. When the TOIs were assumed to be measured with an accuracy of 0.2 mm, on
the other hand, the FWHMs of the 2D-SBP images
were 6 and 2 mm for the ﬁxed and measured DOIs,
respectively. We have already developed a method of
measuring TOI more accurately than the width of the
strip. This method utilizes signals from the strips adjacent to the strip used for DOI measurement. The
implementation of this device is in progress.
References
1) S. Motomura and S. Enomoto: J. Clin. Exper. Med.
205, 884 (2003).
2) Y. F. Yang et al.: IEEE Trans. Nucl. Sci. 48, 656 (2001).
3) S. Motomura et al.: RIKEN Accel. Prog. Rep. 36, 154(2003).
4) M. Momayezi et al.: Proc. SPIE 3768, 530 (1999).

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RIKEN Accel. Prog. Rep. 37 (2004)

Three-dimensional imaging by GREI system
S. Motomura, H. Takeichi, M. Kibe,∗1 Y. Gono, A. Odahara,∗2 S. Enomoto, and Y. Yano
The Compton camera for γ-ray emission imaging1)(GREI) consists of double-sided orthogonal-strip(DSOS) germanium (Ge) detectors which are arrangedin parallel. The GREI system makes it possible toobtain three-dimensional (3D) images of radioisotopes(RIs) distributed in a sample by measuring the sample from only one direction. This is an advantage of
employing a Compton camera system.
In order to examine the feasibility of 3D imaging using the GREI system, we produced 3D simple
back-projection (3D-SBP) images by simulations using GEANT. The 3D-SBP images were obtained byaccumulating three-dimensionally the cones defined foreach event. The depth of a γ-ray interaction pointin the DSOS Ge detector was assumed to be measured with an accuracy of 1 mm in the full width at
half maximum. A point source of 1115 keV γ-rays was
positioned at the origin of the coordinate axes. The
Compton camera was located on the z-axis. The distance between the source and the center of the first
DSOS Ge was 6.9 cm. In addition, we performed simulations of 3D-SBP by employing two Compton cameras. The second Compton camera was located on thex-axis with the same distance from the source as thatof the first Compton camera.
The 3D-SBP images (the section on the y = 0 surface) produced by the above simulation are shown in
Fig. 1. One can see that their shape is distorted. Notethat these images are not the final images that we intend to obtain; they are used as point-spread functions(PSFs) when 3D images are deconvoluted.
The quality of these images was evaluated on thebasis of their Fourier power spectrum (Fig. 2). Whenthe spatial frequency is higher than fc , as indicated inFig. 2, the Fourier power is dominated by the random
noise contained in the image. Thus the component of
the image cannot be reconstructed if the frequency isFig. 2. Fourier power spectra of PSFs.

higher than fc . When only one Compton camera isused, fc in the z-direction is much lower than that inthe x-direction. When two Compton cameras are used,on the other hand, fc in the z-direction is improved tothe same level as that in the x-direction. Therefore,
it is advantageous to use two Compton cameras for
obtaining 3D images.
In addition, an example of 3D imaging using the
GREI system is shown in Fig. 3. A 3D-SBP was obtained from measured data first, then deconvoluted bya shift-invariant PSF. The image of the RI was successfully visualized three-dimensionally.

Fig. 3. 3D image of 137 Cs distributed in a soybean sample.
Photograph of the sample is also shown at the center.

Fig. 1. Slices of 3D-SBP images on y = 0 surface. (a) One
Compton camera. (b) Two Compton cameras.
∗1
∗2

138

Graduate School of Science, Kyushu University
Nishinippon Institute of Technology

References
1) S. Motomura and S. Enomoto: J. Clin. Exper. Med.
205, 884 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Reconstruction methods for GREI
H. Takeichi, S. Motomura, R. Hirunuma, K. Igarashi, S. Enomoto, and Y. Yano
Reconstruction methods for emission imaging were
examined and a version of maximum likelihood
expectation-maximization (MLEM) algorithm for γ
ray emission imaging (GREI) was implemented.
The development of computed tomography (CT) has
been one of the most remarkable achievements in medical imaging physics. The internal structure of a threedimensional sample can be reconstructed from a set oftwo-dimensional projections through computation, enabling precise and nondestructive measurement of the
shape and location of an object inside, such as an organ
or a tumor.
CT application to an imaging modality other than
X ray such as emission tomography and magnetic resonance imaging provided not only considerable diagnostic information but also problems speciﬁc to the
new technique. In the case of GREI, unlike the collimated emission imaging, views from varying viewpoints are obtained not by rotating the detector but
by accumulating data with various scattering angles
following Compton kinematics; therefore, the images
are ‘merged’ and not separated into diﬀerent projection images. The data is in a six-dimensional space
where each γ ray is represented by a set of six parameters: three for the location of the interaction, one
for the scattering angle, and two for the orientation ofthe γ ray. Each γ ray deﬁnes a cone surface on which
the source lies instead of a line in the reconstruction.
In this report, problems associated with the ‘merged
cone’ representation and the solution will be described.
The easiest reconstruction method is simple backprojection (SBP), in which the cone surface is simply‘drawn’ in the reconstruction space, representing theprobability distribution or the uncertainty of the location of the source. When all the cone surfaces are overlaid, they collectively describe the estimation of thesource distribution, namely, the reconstruction. Just
as the estimated source location is ‘smeared’ along theline of projection in the collimated emission imaging,
the estimated source is distributed uniformly over thesurface of the cone in SBP-GREI. Although this may
provide an impression that SBP-GREI is skewed in
a complicated manner, with a number of γ rays, theblur is described by a smooth point spread function(PSF), which can be either measured experimentallyor estimated by simulation. Because PSF depends onthe energy that determines the scattering angle, it isspeciﬁc to a nuclide.
An improved reconstruction method, therefore, isdeconvolution after back projection (DABP), in which

Fig. 1. Sample images obtained by SBP, DABP, andMLEM.

the blur is removed from SBP by deconvolving PSF.
Although this may appear valid as long as only aplanar-thin sample such as a slice is imaged and theestimation of z is not critical, such as astrophysics applications of the Compton camera, DABP suﬀers fromsevere distortion in three-dimensional reconstructionof a volumetric sample. This is because PSF is notshift-invariant along the z-axis, although it is roughly
shift-invariant along the x- and y-axes except at the
periphery of the detector. The radius of the circle deﬁned as a cross section of the cone increases linearlywith increasing distance from the detector, introducing diﬀerent blurs at diﬀerent depths, so that PSF isz-dependent. Note that an analytical distortion compensation is diﬃcult because the required compensation depends on the true source distribution estimated.
Therefore, we implemented an iterative MLEM algorithm for GREI. The idea of MLEM is to iteratively
update the estimated source distribution depending ona correction term. The correction term is deﬁned as
the ratio of the actual projection to the forward projection of the current estimate and back-projected into
the reconstruction space using the probability of a γ
ray being emitted from a location in the sample spaceand detected at a location in the projection. The probability can be estimated by simulation or calculated
analytically in some cases.
Figure 1 shows images obtained by diﬀerent reconstruction methods. From left to right, the SBP, DABP,
and MLEM images of a young soybean shoot administered with 65 Zn single tracer are shown. Instead ofthe exact PSF, a Butterworth ﬁlter was used in DABP
to reduce high spatial frequency noise. MLEM is theresult of > 700 iterations. The MLEM image appears
less noisy than the DABP image.
In summary, MLEM is implemented as an initial reconstruction method for GREI. Improvements in estimation accuracy and computational eﬃciency are under consideration.

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RIKEN Accel. Prog. Rep. 37 (2004)

A note on the reconstruction method for GREI
H. Takeichi
The relationship between image reconstruction andstatistical data analysis in an application of γ ray emission imaging (GREI) to functional brain imaging is
discussed and their integration, cascaded expectation
maximization (CEM), is proposed.
Estimation is always accompanied by error, whichneeds to be minimized. In its minimization, it is important to identify its characteristic property and takean appropriate strategy depending on the property. In
functional brain mapping by emission imaging, for example, the result of the statistical data analysis depends partially on the choice of the image reconstruction method. This may be because the nature as wellas the magnitude of the error depends on the reconstruction method. In other words, when the image
reconstruction is designed, the manner in which thereconstructed image is used needs to be considered. In
this report, the nature of the error in two image reconstruction methods for GREI and two data analysis
methods in functional brain imaging are described andtheir relationship is discussed.
As described elsewhere in this volume, there are
two types of reconstruction methods: analytical anditerative. The analytical method is a shift-invariant
deconvolution called deconvolution after back projection (DABP), and the iterative method involves iterative error estimation and propagation using a shiftinvariant or a shift-variant probability relating the projection and the reconstruction, called maximum likelihood expectation-maximization (MLEM). Only the effect of an error in the estimated point spread, i.e. point
spread imperfection (PSI) will be considered. PSI is
uniformly distributed over the entire image in DABP,
because it is in the shift-invariant deconvolution kernel, while PSI can be nonuniformly distributed andconﬁned to a neighborhood in MLEM, because it canbe localized to a subset of the probabilities relating the
projection and the reconstruction. Although MLEM is
more advantageous than DABP with respect to image
reconstruction itself, it is also important to examine
their relative superiority and inferiority with respect
to their application.
In functional brain imaging, the eﬀect of an experimental manipulation is evaluated by generating a mapthat represents a change in the metabolism or the regional cerebral blood ﬂow due to the manipulation ateach location in the brain. There are two methods forgenerating the map: model-based and data-driven.
In the model-based method, the eﬀect is measured
in terms of the mean signal diﬀerence between the activation state and the resting state at each location.

140

The Student’s t-test is often performed with a correction for multiple comparisons. This is called generallinear model (GLM) because it assumes that the experimental eﬀect is linear. The model is described asfollows:
X = βG + ε
where X is the data i.e. the signal at each location ateach time point, β is the coeﬃcient for the magnitudeof the eﬀect at each location, G is the time course of
the eﬀect, and ε is the residual error. In this case, G isgiven and β is estimated and compared with ε.
In the data-driven method, the eﬀect is characterized as a coherent mean signal diﬀerence between thestates at a set of locations. The most signiﬁcant diﬀerence between the model-based method and the datadriven method is that the former uses an extrinsic
model i.e. the time course of the experimental manipulation for the identiﬁcation of the eﬀect, while
the latter uses an intrinsic criterion i.e. the statistical independence between the eﬀects for their identiﬁcation. A popular deﬁnition of independence is theabsence of correlation, which is identiﬁed by analyzing
covariance. This is called principal component analysis(PCA). A revised deﬁnition is the absence of mutual
information, which can be identiﬁed by analyzing the‘co-kurtosis’ or higher order statistics. This is called
independent component analysis (ICA). In both cases,
the analysis is described as follows:
X = βG
where the residual error is omitted because it is notessential in this analysis.
A critical diﬀerence between GLM and ICA with respect to the image reconstruction method is that while
the eﬀect is evaluated for each location in GLM, it isevaluated for each set of locations in ICA. Because
GLM is a highly localized analysis, it is more susceptible to the localized PSI in MLEM than to the distributed PSI in DABP. In contrast, because ICA isless localized, the inﬂuence of localized PSI in MLEM
is less severe than GLM.
In addition, as ICA can be implemented by
an expectation maximization algorithm, there isa possibility of performing cascaded expectation
maximization (CEM) by combining the image reconstruction (MLEM) and the statistical data analysis(ICA). By establishing a direct link between the measurement and the application, CEM enables an adaptive and real-time analysis of a complex system.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Image reconstruction method with compensation for scattering
angular uncertainty in MT-GEI
M. Hirasawa,∗1 T. Tomitani,∗1 S. Shibata,∗1 S. Motomura, S. Enomoto, Y. Gono,∗2 and Y. Yano
The MT-GEI (multitracer gamma-ray emission imager) has been developed to image living-body tomograms of multitracers produced at the RIKEN Ring
Cyclotron. Multitracer imaging can be attained using
an imaging device based on the Compton camera principle. The MT-GEI consists of two three-dimensional
position-sensitive γ-ray detectors. The γ ray emitted
from the each tracer undergoes Compton scattering inthe ﬁrst detector followed by photoelectric absorption
in the second detector. The direction of the γ ray
can be conﬁned to a cone whose vertex, axis and vertex angle are determined by the scattering point, thescattering ray line and twice the Compton scattering
angle, respectively. The scattering angle is calculated
from the deposited energies using the Compton formula. However, the calculated angle includes uncertainty due to the ﬁnite energy resolution of the ﬁrst
detector and the Doppler broadening of the Compton
electron energy in the ﬁrst detector. Figure 1 shows thedependence of the angular uncertainty in the MT-GEI
on the emitted γ-ray energy for scattering angles of 10,
20 and 30 degrees. As the energy increases, the uncertainty decreases rapidly and tends to level oﬀ to 2 orless degrees in FWHM beyond 300 keV.
An image reconstruction method using the cone dataobtained by the MT-GEI was developed ﬁrst without

Fig. 1. Dependence of scattering angular uncertainty in
MT-GEI on incident γ-ray energy. Solid, dashed anddotted curves correspond to the scattering angles of 10,
20 and 30 degrees, respectively.
∗1∗2

National Institute of Radiological Sciences
Kyushu University

compensating for the above angular uncertainty.1) The
algorithm has been revised to compensate for the uncertainty as2) 1
αn (cos ω) ≡ds, tBr t (s, t; ω)Pn (s, t),(1)−1
 cos ω1Hn ≡d cos ω h(cos ω)αn (cos ω)2 ,(2)cos ω2andf (s) ≈

 cos ω1d cos ωcos ω2
n
max

×

S

dΩt

2n + 1 αn (cos ω)
Pn (t, s)g(t; ω), (3)
4π
Hn
n=0

where f (s) denotes the relative tracer density line integrated on a line with s in its direction unit vector,
and g(t; ω) represents the number density of cone datawith t in its axial (scattering)-direction unit vector
with half of its vertex (calculated scattering) angle ω.
Furthermore, Pn and h denote the Legendre functionof n-th degree and the Klein-Nishina formula, respectively, and Ωt and s, t are the solid angle with t in its
direction unit vector and the inner product of s and t,
respectively. Br describes the scattering angular uncertainty deﬁned by

Fig. 2. Reconstructed images with (left) and without(right) compensation from the simulated cone data for
MT-GEI. The top is the original phantom.

141

Br (s, t; ω) ≡ √(s, t − cos ω)2
1
exp −
,
2(σ sin ω)22π σ sin ω(4)sation has higher spatial resolution but greater noise
than that without compensation.3,4)Referenceswhere σ is the standard deviation of the scattering
angular uncertainty.
Figure 2 shows the reconstructed distribution images
with and without compensation for the angular uncertainty. The 108 cone data obtained by the MT-GEI,with 10 to 30 degrees in the calculated scattering angle, are simulated using a digital phantom emitting
364 keV γ rays. The reconstructed image with compen-

1421) T. Tomitani and M. Hirasawa: Phys. Med. Biol. 47,
2129 (2002).
2) M. Hirasawa and T. Tomitani: Phys. Med. Biol. 48,
1009 (2003).
3) T. Tomitani and M. Hirasawa: IEEE Trans. Nucl. Sci.
50, 1602 (2003).
4) M. Hirasawa and T. Tomitani: Proc. 2003 IEEE NSS/
MIC, M14-303 (2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Exposure of frozen human cells to heavy ions
F. Yatagai, H. Ryuto, N. Fukunishi, and F. Hanaoka
Exposure to ionizing radiation (IR) induces various
types of DNA lesion including base damage, crosslinking, and DNA single- and double-strand breaks(DSBs). DSBs were originally considered to be thecritical cytotoxic lesions. We have recently establisheda gene mutation assay system whose target is the autosomal heterozygous thymidine kinase (T K) locus in
the human lymphoblastoid cell line TK6.1) This assay system enables the detection of genetic alterations
at the chromosome level as loss of the functional allele (or loss of heterozygosity (LOH)). Using this assay system, we succeeded in the (10 cGy) detection of
IR-speciﬁc hemizygous LOHs (interstitial deletions).2)
The 22 keV/µm C ion beam irradiation has shownhigher induction of such an LOH event than X-ray irradiation,3) probably due to an eﬃcient production of
DSBs by C ions compared to X-rays.4)
The direct eﬀect of an accelerated heavy ion beam on
DNA can be well estimated by the irradiation of frozen
cells, because the indirect eﬀect mediated by free radicals can be suppressed under such a frozen condition.
Furthermore, the long-period preservation of cells by
freezing is convenient for detecting the genetic eﬀects
of low-dose and low-dose-rate irradiation. The above
LOH assay system appeas to be very useful for elucidating genetic changes in IR-irradiated frozen cells.
The preliminary results obtained are described below.
The viability of TK6 cells was estimated from plating eﬃciency (PE) (Table 1), which was determinedby the limiting dilution method as previously described.1–3) TK6 cells were exposed to IR under the

Table 1. Reduction in the viability of cells irradiated under
the frozen condition and preserved by freezing after theirradiation.
Radiation(Frozen§ )X-rays(1 week)
X-rays(1 month)
C ions(1 week)
C ions(1 month)§

Plating Eﬃciency (%) [Relative]
0 Gy 0.1 Gy 0.5 Gy 2.0 Gy
25
21
13
5.1
[1.0] [0.84][0.52][0.20]
6.1
5.6
3.8
4.3
[1.0] [0.92][0.63][0.70]
8.3
8.8
6.4
1.4
[1.0] [1.06][0.77][0.17]
10
8.5
8.3
5.2
[1.0] [0.85][0.83][0.52]

frozen condition (−80 C) and preserved at the same
temperature after the exposure.
The relative PE of the cells preserved for one week
after the 2 Gy X-ray exposure was 20% that of unirradiated cells, indicating a percentage higher than 8% in
our previous experiment under the suspension-culture
conditions. Such higher viability was also observed after the 2 Gy C ion irradiation, as determined by the relative PEs of 17% and 6% under the frozen and suspension conditions, respectively. These results strongly
suggest that the indirect eﬀect of irradiation on cellkilling is suppressed by the exposure to freezing condition. Similar tendency was obtained with one monthpreservation. The viability was not reduced by the
10 cGy irradiation in any case (Table 1).
The TK− mutation frequencies for the cells irradiated with C ions under the frozen condition and preserved as frozen were also determined by the method
as previously described1–3) (Table 2).
In contrast to the reduction in the cell killing eﬀect of
C ion exposure under the frozen condition as describedabove, the enhancement of mutation frequency was
similar or rather higher than that in the cell-suspension
case in our previous study.3) A higher induction of mutation was observed with a longer preservation. Our
future analyses for the LOH events detected as TK−
mutations can be expected to contribute to the basic
understanding of direct-hit DNA damage as well as theestimation of the genetic eﬀects of low-dose irradiation.
Table 2. Mutation frequencies for cells irradiated with C
ions under the frozen condition and preserved as frozen.
Frozen period
after C ion
exposure
2 days1 monthMutation Frequency (× 10−5 )“PE (%) [Relative value]”
0 Gy
0.1 Gy2.0 Gy1.4
1.6
6.0“23 [1.0])” “17 [0.74]” “18 [0.78]”
1.9
5.1
17
“21 [1.0]”“16 [0.76]” “11 [0.52]”

References
1) M. Honma et al.: Mol. Carcinog. 28, 203 (2000).
2) S. Morimoto et al.: Radiat. Res. 157, 533 (2002).
3) S. Morimoto et al.: J. Radiat. Res. 43 Suppl. 163 (2002).
4) G. Taucher-Sholtz and G. Kraft: Radiat. Res. 151, 595(1999).

Period of freezing after radiation exposure143

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀects of heavy-ion irradiation on DNA replicationin mammalian cells
M. Izumi, T. Tsukada, M. Tomita, N. Fukunishi, H. Ryuto, F. Yatagai, and F. Hanaoka
Eukaryotic cells have surveillance mechanisms, orcheckpoint pathways, which detect damaged DNA or
ongoing DNA replication and block cell cycle progression in order to allow suﬃcient time for repair of damaged DNA or to complete replication. In response
to a moderate dose of ionizing radiation, the overall
rate of DNA replication in an asynchronously growing
mammalian cell culture is reduced by ∼50% within
30 min.1) This response is mainly caused by inhibiting
subsequent initiation at origins of replication, while allowing forks already in progress to continue.1) Recent
studies have shown that mammalian cells exposed toionizing radiation such as X-rays activate the ATM
kinase, which triggers two parallel cascades that cooperate to inhibit DNA synthesis, although further studies are necessary to identify the downstream targets ofthese cascades.2) In this study, we examined the cell
cycle progression and the rate of DNA synthesis of human lymphoblastoid TK6 cells after irradiation withcarbon ions (LET: 22 keV/µm).
When TK6 cells were irradiated with 1 Gy of carbon
beam, most cells were arrested at G1 or G2 phase 16 h
after irradiation (Fig. 1). The rate of bromodeoxyuridine (BrdU) incorporation did not change after irradiation and S phase progressed without retardation.
These results indicate that TK6 cells undergoing DNA
replication did not respond to ionizing radiation levels
that were able to block cells in G1 or G2 phase. ThisS phase speciﬁc resistance against DNA damage appears to occur in budding yeast as well.3) It has beenreported that replication forks pause frequently during a normal S phase, often leading to parental strand
breakage.4,5) The threshold necessary for the checkpoint activation may be elevated during S phase sothat damage arising from normal fork progression does
not cause cell cycle arrest.
On the other hand, the rate of BrdU incorporation
was suppressed when cells were irradiated at higher
dose. Interestingly, the suppression in the late S phase
was observed even at 3 Gy (Fig. 1, white arrows),
whereas the suppression in the early S phase required
5 Gy irradiation (Fig. 1, black arrow). The diﬀerent
sensitivities between early S phase and late S phase
may be due to the diﬀerent chromatin structures,i.e., the higher levels of irradiation are necessary for

144

Fig. 1. Rate of DNA synthesis and cell cycle progression of
TK6 cells after carbon-ion irradiation (1, 3, or 5 Gy).
TK6 cells were pulse-labeled with 10 µg/ml bromodeoxyuridine (BrdU) for 30 min at indicated hours after irradiation and stained with FITC-conjugated antiBrdU antibody. Chromosomal DNA was stained withpropidium iodide. BrdU incorporation and DNA content (2N, 4N) were measured by flow cytometric analysis. White arrows indicate the suppressed DNA replication in the late S phase. The black arrow indicatesthe suppressed DNA replication in the early S phase.

suppressing DNA synthesis when the euchromatic regions are replicated. Alternatively, the diﬀerent stagesof S phase provoke diﬀerent checkpoint responses withrespect to the components or the activated levels ofcheckpoint pathways. At present, we are analyzing
the checkpoint response after heavy-ion irradiation in
more detail.
References
1) J. M. Larner, H. Lee, and J. L. Hamlin: Mol. Cell. Biol.
14, 3 (1994).
2) J. Falck, J. H. J. Petrini, B. R. Williams, J. Lukas, and
J. Bartek: Nat. Genet. 30, 290 (2002).
3) K. Shimada, P. Pasero, and S. M. Gasser: Genes Dev.
16, 3236 (2002).
4) A. M. Deshpande and C. S. Newlon: Science 272, 1030
(1996).
5) Y. Wang, M. Vujcic, and D. Kowalski: Mol. Cell. Biol.
21, 4938 (2001).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀect of heavy ions on the activation of DNA
double-strand break repair proteins
M. Tomita, A. Naruto,∗ T. Tsukada, M. Izumi, N. Fukunishi, H. Ryuto, and F. Yatagai
DNA double-strand breaks (DSBs) are the mostlethal damage induced by ionizing radiation. Accelerated heavy ions have been shown to induce DNA
clustered damage, which is two or more DNA lesions
induced within a few helical turns. The higher biological eﬀectiveness of heavy ions could be caused predominantly by the induction of complex DNA clustereddamage, leading to nonrepairable DSBs.1) In mammalian cells, DSBs are repaired by mainly two distinct and complementary mechanisms, namely, nonhomologous end-joining (NHEJ) and homologous recombination (HR).2) DNA-dependent protein kinase(DNA-PK) is composed of a catalytic subunit (DNAPKcs) and DNA-binding heterodimers (Ku70 andKu86). DNA-PK acts as a sensor of DSB for the
NHEJ, since DNA-PK is activated to bind to the ends
of double-stranded DNA.3) Cells defective in each of
the DNA-PK components are extremely radiosensitive.
It has been reported that human radiosensitive malignant glioma M059J cells do not express DNA-PKcs.4)
To elucidate the physiological role of DNA-PK in thecellular response to heavy-ion-induced DSBs, we examined the sensitivity of M059J cells and control M059K
cells, which have a normal level of DNA-PKcs expression, to accelerated heavy ions.
Figure 1 shows the clonogenic surviving fractionsof M059K and M059J cells irradiated with 250 kV Xrays, 135 MeV/u carbon ions (C ions) at 80 keV/µm,
490 MeV/u silicon ions (Si ions) at 200 keV/µm,
95 MeV/u argon ions (Ar ions) at 300 keV/µm and
90 MeV/u iron ions (Fe ions) at 1000 keV/µm. The
surviving factions were determined by a colony formation assay. DNA-PKcs-defective M059J cells weremore sensitive to both X-rays and heavy ions thancontrol M059K cells. The radiosensitivities of both
M059K and M059J cells to C, Si and Ar ions werehigher than those to X-rays and Fe ions. The lower
cell-killing eﬃciency of Fe ions than those of C, Si and
Ar ions was caused by particle energy deposition inexcess of cell killing, usually named the over-killing effect.
The relative biological eﬀectiveness (RBE) were calculated using the dose leading to 10% cell survival(D10 ) from cell survival curves. Figure 2 shows therelationship between LET and RBE. In general, theRBE increased with LET, reaching maximum, andthen decreased.5) The RBE of M059J cells, however,was signiﬁcantly lower than that of M059K cells. The
peak RBE values were 2.01 and 2.93 for M059K cells,and 1.76 and 1.84 for M059J cells at 80 keV/µm and300 keV/µm, respectively. Previously, we have reported that HR-related proteins, NBS1 and histone
H2AX, recognized heavy-ion-induced DNA clustereddamage.6) Our present and previous results suggestthat both HR and NHEJ play important roles in the
repair of the heavy-ion-induced DSBs, and that thecellular RBE is partly determined by the cellular DNA
repair capacity.

Fig. 2. Relative biological eﬀectiveness (RBE) of accelerated heavy ions in M059K and M059J cells. The RBE
values were calculated using the dose leading to 10%
cell survival (D10 ) from cell survival curves.

References

Fig. 1. Cell survival curves for M059K (A) and M059J (B)cells irradiated with X-rays (2 keV/µm, open circle), C
ions (80 keV/µm, solid box), Si ions (200 keV/µm, solid
triangle), Ar ions (300 keV/µm, solid circle) or Fe ions(1000 keV/µm, solid diamond).
∗

Laboratory of Environmental and Molecular Biology, Tokyo
University of Pharmacy and Life Science

1) E. A. Blakely and A. Kronenberg: Radiat. Res. 150,
S126 (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) S. Lees-Miller et al.: Science 267, 1183 (1995).
5) Y. Furusawa et al.: Radiat. Res. 154, 485 (2000).
6) M. Tomita et al.: RIKEN Accel. Prog. Rep. 36, 133(2003).

145

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

High dose of heavy-ion beams cause p53 -dependent cell death
T. Tsukada, M. Tomita, N. Fukunishi, H. Ryuto, and M. Izumi
It is well known that the tumor suppressor gene p53
promotes cell cycle arrest or apoptosis after DNA damage.1) P53 is one of the target substrate of activated
ATM kinase in X-ray irradiation, related to the cascade of repair of the damaged DNA. Heavy-ion beams
have been known to induce clustered DNA damage efﬁciently, and it is considered that such severe damage
is diﬃcult to repair.
To clarify the p53 functions at cellular responses after exposure to heavy-ion beams, we used two human
B-lymphoblast cell lines derived from the same donor
but diﬀering in the p53 status: TK6 (wild-type p53 ),and NH32 (p53 deﬁcient) and examine the viabilitiesof these cells after the irradiation.
In our previous report, there are no signiﬁcant diﬀerences in apoptotic rate between TK6 and NH32 at 3 Gyof C ions (22 keV/µm) or Fe ions.2) However, exposure
to heavy-ion beams, such as C ions or Fe ions, induced
p53 expression,3) suggesting that p53 may also play animportant role in cellular responses induced by heavyion beams. In this study, we examined the involvementof p53 in the cell death process in more detail.
Cells were exposed to heavy-ion beams (C ions:
22 keV/µm or 80 keV/µm, Fe ions: 1000 keV/µm, Ar
ions: 300 keV/µm) at doses of 1, 3, 5, 10 Gy (Cions: 22 keV/µm, Fe ions) and 1, 2, 3,5 Gy (C ions:
80 keV/µm) and 0.5, 1, 2, 3, 5, 10 Gy (Ar ions). Apoptosis was determined by the externalization of phosphatidylserine and was measured as annexin V-positive
cells by ﬂow cytometry.
Figure 1 shows the percentage of annexin V-positive
cells, which included apoptotic cells (annexin V+,PI−) and late phase apoptotic cells or necrotic cells(annexin V+, PI+). Lower doses of heavy-ion beams(C ions: 1, 3 Gy, Fe ions: 1, 3 Gy, Ar ions: 0.5, 1 Gy)
caused cell death in TK6 (wild-type p53 ) or NH32
(p53 deﬁcient), however, there were no signiﬁcant differences in the percentage of cell death between TK6
and NH32. On the other hand, higher doses of heavyion beams (C ions: 5, 10 Gy, Fe ions: 5, 10 Gy, Ar
ions: 2, 3, 5, 10 Gy) induced extensive cell death in
TK6. In contrast, cell death was triggered at a signiﬁcantly lower percentage in NH32. Moreover, percentages of both annexin V+, PI− cells and annexin
V+, PI+ cell increased following higher-dose irradiation in TK6. This suggests that p53 is involved in
the process of cell death, which may include not only
apoptosis but also necrosis caused by high-dose of eachhigh-LET (22, 80, 300, 1000 keV/µm). Alternatively,
it was reported that there must be a diﬀerence in DNA

146

Fig. 1. Phosphatidylserine externalization in TK6 (p53 +/+) and NH32 (p53 −/−) cells 24 hour after irradiation with C ions (22 keV/µm or 80 keV/µm), Fe ions(1000 keV/µm) or Ar ions (300 keV/µm). Cells (5×105 )were labeled with annexin V-FITC and propidium iodide (PI), and analyzed by flow cytometry. Apoptosis
is expressed as the percentage of cells positive for annexin V-FITC. The lower part of each column indicatesannexin V(+), PI(−) cells (apoptotic cells), the upper
part of each column indicates annexin V(+), PI(+) cells(late phase of apoptotic cells and necrotic cells). Eachcolumn shows the average data (except Ar ions) of bothannexin V(+), PI(−) cells and annexin V(+), PI(+)
cells.

replication damage between irradiation with a low dose
and that with a high dose of C-ion beams.4) The suppression of the late S phase was observed at both 3 Gyand 5 Gy, whereas the suppression of the early S phaserequired 5 Gy irradiation in TK6.4) Therefore, our result suggests that p53 may also be involved in speciﬁc
pathways of checkpoint or replication of euchromatic
regions.
References
1) T. Jacks et al.: Curr. Biol. 4, 1 (1994).
2) T. Tsukada et al.: RIKEN Accel. Prog. Rep. 36, 131(2003).
3) S. Morimoto et al.: RIKEN Accel. Prog. Rep. 34, 177(2001).
4) M. Izumi et al.: RIKEN Accel. Prog. Rep. 37, 144(2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀect of heavy-ion beam irradiation on mutation induction in
Arabidopsis thaliana
H. Saito, T. Matsuyama, Y. Y. Yamamoto, T. Abe, and S. Yoshida
Since high linear energy transfer (LET) heavy-ion
beams cause clustered damages including DNA doublestrand breaks,1) they seem to be more eﬀective forinducing mutations than low LET radiation such as
X-rays, γ-rays and electrons. In basic plant sciences,mutants defective in a biological process provide useful tools for genetic analysis. Arabidopsis (Arabidopsis
thaliana) is one of the model plants and often usedin such genetic analyses. To achieve eﬀective mutagenesis of arabidopsis, we evaluated the conditions ofheavy-ion beam irradiation on mutation induction.
Dry seeds of arabidopsis ecotype Columbia (about
250 µm in diameter) were packed with Hybri-Bag Hard(95 µm thickness, Cosmo Bio Co., Ltd.) to provide
a monolayer of the seeds for homogenous irradiation.
They were irradiated with 12 C, 20 Ne, 40 Ar and 56 Fe
ions with a dose range of 5 to 400 Gy. These ions wereaccelerated up to 135, 135, 95 and 90 MeV/nucleon,
and their LETs were 23, 61, 280 and 630 keV/µm, respectively. Furthermore, to determine the eﬀects of
the LETs of heavy ions on mutagenesis, the LET of
C ion beams was increased to 63 keV/µm after passing through a set of absorbers in the range shifter.
All LETs were calculated at the seed surface. The
irradiated M1 seeds were incubated on 1/2 MS agar
medium at 4◦ C in darkness for 3 days for vernalization and then at 22◦ C under continuous illumination.
The germination rate (number of germinated seeds per
total number of incubated M1 seeds) was determined
2 to 3 weeks after the initiation of incubation. Trueleaf-developed seedlings were transplanted to plastic
trays (13×9 cm) containing soil. Eleven seedlings wereplanted in each tray and cultured at 22◦ C under continuous illumination in the greenhouse. The ﬂowering
rate (number of ﬂowering plants per total number of incubated M1 seeds) was determined one month after thetransfer. M2 seeds were harvested from self-pollinatedM1 plants in each tray. M2 seeds were similarly collected and incubated under the same condition as thatfor germinating M1 seeds. The frequencies of albino
plants (number of albino plants per total number ofgerminated M2 seedlings) were measured after mostseedlings expanded cotyledons.
In the control seeds without irradiation, the germination rate was 97.1% and all seedlings ﬂowered until
one month after transfer to soil. The eﬀects of heavyion beam irradiation on mutagenesis in arabidopsis
are shown in Table 1. Germination of M1 plants was
not aﬀected by irradiation with any ions at the doses
tested. However, the decrease in the ﬂowering rateof M1 plants was observed in accordance with the in-Table 1. Eﬀect of heavy-ion beams on mutation induction
in Arabidopsis.
Ion

LET(keV/µm)

Dose
(Gy)

Control
C

–
23

C

63

Ne

61

Ar

280

Fe

640

–
50
100
150
200
400
50
100
150
200
400
50
100
150
200
400
5
10
20
50
100
150
200
5
10
20
50
100
150
200

No.
of M1
seeds§1
680
371
256
210
279
255
439
455
446
413
358
515
412
390
393
301
580
567
479
499
445
452
341
410
408
341
324
226
196
210

Germination
rate of M1
plants (%)
97.1±2.593.5±4.0
86.0±2.589.3±3.994.2±1.0
91.1±4.2
95.8±0.5
98.1±0.692.3±3.798.2±0.5
96.0±1.6
97.6±0.492.9±3.991.8±5.4
88.5±7.987.2±6.3
97.9±1.1
94.2±5.3
94.6±4.3
97.6±2.1
93.9±4.0
92.6±5.995.5±3.7
97.0±0.393.8±1.992.9±4.2
95.6±3.0
94.1±1.8
91.4±3.486.9±6.4

Floweringrate of M1
plants (%)
97.1±2.593.5±4.0
83.1±0.887.3±4.3
81.2±0.734.2±11.6
94.8±0.693.1±1.8
91.4±3.2
19.2±17.1
0.8±0.1
94.9±1.991.8±3.590.3±4.483.2±8.9
3.0±1.989.5±2.1
88.2±4.8
91.4±4.3
92.2±2.0
1.2±1.20096.6±0.293.5±2.092.9±4.2
94.4±3.174.9±4.7
5.9±5.90% of albino
M2 plants
0.07±0.07
0.16±0.1
0.48±0.4
0.34±0.1
0.53±0.1
nd§2
0.80±0.1
1.35±0.4
1.92±0.4
ndnd0.30±0.2
1.02±0.4
1.67±0.7
0.39±0.1nd
0.20±0.1
0.32±0.1
0.26±0.1
1.37±0.3
nd
ndnd
0.10±0.1
0.35±0.3
0.17±0.1
0.42±0.2
1.09±1.0
ndnd§1 Total number of irradiated M seeds from three experiments.
1§2 Data were not determined.

crease in doses. For most M1 plants after high-dose
irradiation, growth-decreased plants produced a few
seeds. Among the irradiation conditions using the different energies of C ions, LET of 63 keV/µm was more
eﬀective for inducing albino plants. Similar frequencies of albino plants were observed for both irradiation
treatments by C ions with LET of 63 keV/µm and by
Ne ions with LET of 61 keV/µm. Also, the same doses
were required for higher frequencies. It has been reported that the lethality rate after ion beam irradiation
was aﬀected by LET in arabidopsis: Ne or Ar ions with
LET higher than 350 keV/µm were more eﬀective than
113 keV/µm C ions.2) The LET of ion beams seems to
be an important factor for the eﬃcient mutagenesisof plants. More detailed studies using several ions at
diﬀerent LETs are in progress.
In the present study, not only albino plants but also
several morphologically abnormal plants, such thosewith variegation, pale green color, longer hypocotyl
and higher anthocyanin accumulation, were isolated
in the M2 generation derived from seeds irradiated by
all ion beams tested. Molecular analyses of mutatedgenes to clarify the eﬀect of ions and their LETs arealso in progress using these mutants.
References
1) D. T. Goodhead: Int. J. Radiat. Biol. 65, 7 (1994).
2) N. Shikazono et al.: Radiat. Environ. Biophys. 41, 159(2002).

147

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RIKEN Accel. Prog. Rep. 37 (2004)

Isolation of light stress response mutants of Arabidopsis thaliana
by heavy ion beam irradiation
Y. Y. Yamamoto, T. Abe, and S. Yoshida
Plants utilize sunlight for photosynthesis, and thus
light is indispensable for plant growth. On the other
hand, exposure of plants to high-intensity light, calledhigh light (HL), harms their photosynthetic apparatus. Development of a protective mechanism against
HL is one of the prerequisites for plant survival on
the land. It is known that the adaptation of higher
plants is achieved in part by the regulation of gene expression.1) However, little is known about how plants
recognize HL environments and alter their gene expression proﬁle accordingly. Our research aims to elucidate
the molecular mechanisms behind the perception of HL
environments and the subsequent signal transduction
leading to gene activation. Because the perception issuggested to occur in the chloroplast and the gene activation in the nucleus,2,3) the HL signal is considered
to be transduced in an inter organellar fashion, which
is one of the unique characteristics of this signaling
system.
Recent studies have revealed that the HL responseis mediated by at least two independent pathways, andone of which leads to the activation of ELIP genes2)
encoding antistress proteins that protect plants fromlight stress. Therefore, the activation of ELIP genes
by HL is one of the strategies for plant survival in
HL environments. To identify the components involved in HL-activated gene expression, we decided totake the genetic approach. An established transgenic
Arabidopsis line carrying a ﬁreﬂy luciferase reporter
gene, ELIP2::LUC, activates luciferase-based bioluminescence in response to HL.2) The response of the reporter can be monitored in a nondistruptive manner,
therefore, this assay system is suitable for the screeningof mutants defective in the HL response.
Because heavy ion beam irradiation tends to cause
short (1 to 10 bps) deletions in the genome,4) it isexpected to provide null mutants due to frameshift.
Such mutants would be suitable for investigating genefunction relationships. Dry seeds of the reporter line
were irradiated with a C6+ beam at a dose of 150 Gy.
The treated seeds were grown in a greenhouse to provide self-crossed M2 generation. M2 seedlings weregrown at a light intensity higher than that of the optimal growth conditions for Arabidopsis (50–70 W/m2 ),thereby causing light stress. Under this stressful condition, light-stress-sensitive lines were screened for by visual inspection as an indication of paler color of leaves
than wild type. From the screening, 69 lines were identiﬁed as light stress-sensitive mutants out of approximately 2,100 irradiated M1 lines. The identiﬁed mutants were grown, and 46 lines were fertile, providing

148

M3 seeds.
The M3 seeds of the 46 lines were subjected toluciferase-based in vivo assays for HL response.2)
Three types of responses of the mutants were predicted: normal response, as in the wild type, weak
response, and strong response. As shown in Table 1,
as much as 96% (44/46) of the mutants had a normal
HL response. This suggests that although HL-sensitive
mutants suﬀer more light stress than the wild type under HL, generally such physiological conditions do notcause an enhanced HL response. This indicates thatlight stress causing gene activation can be monitored
by a speciﬁc parameter(s) that is not inﬂuenced bymost of the analyzed mutants. As exceptions, two mutant lines showing an enhanced HL response (Table 1,
Table 2) did alter such a parameter(s). Analyses ofthese mutants are expected to provide information on
sensing mechanisms in HL environments by plants.
Table 1. Summary of the mutant screening.
Category
HL-sensitive§1
Higher transcriptional response to HL§2
Lower transcriptional response to HL§2

Line number
46
2
0

§1

Determined by visual inspection of leaves grown under continuous light at 50 W/m2 for 1 to 2 weeks. §2 Determined by the LUC-based gene expression analysis in
response to HL (light intensity of 150 W/m2 for 3 h).
Table 2. HL response of the isolated mutants.
line
Wild type
Mutant 1
Mutant 2

HL response§
1.00
5.00±2.48
3.09±1.57§

Relative value determined by the LUC-based gene expression analysis in response to HL (light intensity of
150 W/m2 for 3 h). Standard deviations are also shown.

References
1) M. Kimura, Y. Y. Yamamoto, M. Seki, T. Sakurai, M.
Sato, T. Abe, S. Yoshida, K. Shinozaki, and M. Matsui:
Photochem. Photobiol. 77, 226 (2003).
2) M. Kimura, T. Yoshizumi, K. Manabe, Y. Y.
Yamamoto, and M. Matsui: Genes Cells 6, 607 (2001).
3) M. Kimura, K. Manabe, T. Abe, S. Yoshida, M. Matsui,
and Y. Y. Yamamoto: Photochem. Photobiol. 77, 668(2003).
4) N. Shikazono, Y. Yokota, S. Kitamura, C. Suzuki, H.
Watanabe, S. Tano, and A. Tanaka: Genetics 163, 1449
(2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Hormesis of heavy-ion irradiation to lettuce
I. Honda,∗ K. Kikuchi,∗ H. Saito, Y. Miyazawa, T. Abe, and S. Yoshida
In 1980, Luchey1) described radiation hormesis as
promotive eﬀects in many living things by their exposure to low doses of X-ray, γ-ray, and radiation frommany radioactive nuclei. He presented more than one
thousand examples of hormesis and advocated its utilization for improving of all living organisms. In general, however, the eﬀects were not signiﬁcant and havethus been sometimes regarded as not holding great potential.
Miura et al.2) examined the possibility of utilizing radiation hormesis in cultivating some vegetables.
They found that lettuce seed germination at a hightemperature was promoted by low-dose γ-ray irradiation, and indicated that this eﬀect may contributeto improving the lettuce productivity, which normallyrequires the preparation of well-grown seedlings formachine transplantation in practical ﬁeld cultivation.
However, the eﬀect they demonstrated in the germination of lettuce was so small as to be considered negligible.
Recently, a heavy-ion irradiation (HII) of plants has
been frequently utilized as a new method to induce
mutation in plants. Abe extensively applied HII technology for various plants and reported that mutation
rates after HII were higher than that of γ-ray irradiation.3) On the other hand, the hormesis-like eﬀect of
HII has been never examined. In this study, we examined whether HII shows hormesis-like eﬀects or not.
Dry seeds of lettuce cv. cisco (Takii Seed Inc.) were
irradiated by 12 C- and 20 Ne-ion beams (135 MeV/u)
at a dose range of 3 to 300 Gy. Eﬀects of HII on
the growth rate were examined under normal cultivaition conditions in soil. Seeds irradiated with lessthan 30 Gy by both heavy-ions grew well, but their
growth was severely inhibited after irradiation above
100 Gy. To examine hormesis eﬀects, low-dose irradiation was conducted in a dose range from 0.1 Gy to30 Gy, and the eﬀects were examined by conducting
a seed germination test.
Fifty seeds were sown in each petri dish (9 cm) containing a two-layer ﬁlter paper and 4 ml of distilledwater, incubated at 35◦ C in the dark, and their germinations were examined daily. At least four dishes
were used in each single experiment to obtain the germination rates. As shown in Fig. 1, the germination
rates of lettuce one day after imbibition were 8–20%
even in nonirradiated (0 Gy) seeds. The germination
rates of 0.1 Gy 12 C- and 3 Gy 20 Ne-ion beam irradiated seeds were slightly higher than those of the control experiment. Incubation was continued for more
3 days, but only few seeds germinated additionally in∗

Fig. 1. Eﬀects of heavy-ion irradiation on the seed germination of lettuce one day after imbibition. Open andclosed bars indicate the eﬀects of 12 C- and 20 Ne-ion
beam irradiation, respectively. The incubation temperatures for 12 C- and 20 Ne-ion samples were 34◦ C and35◦ C, respectively. Error bar indicates standard error.

every experiment, representing slightly higher germination rates for these irradiated seeds. These seeds
were stored at 4◦ C for two days after the above examination, and re-incubated at 25◦ C for two days. This
re-incubation resulted in the germination of more than
90% of the remaining seeds. These results may indicatethat ion-beam irradiation has a certain eﬀect of breaking dormancy in lettuce seeds which is induced by hightemperature.4) As the decrease in the uniformity of lettuce seedlings growth expressed by this dormant likeeﬀect in germination sometimes leads to economic loss
in practical cultivation under high temperature conditions, as suggested by the results there is a possibility
that ion-beam irradiation may be useful for increasing
lettuce productivity. Further studies on suitable ions,doses and other HII methods are required to conclude
the existence of HII hormesis as well as to gain an understanding of its mechanisms.
References
1) T. D. Luchey: Hormesis with Ionizing Radiation (CRC
Press Inc., Boca Raton, 1980).
2) S. Miura, H. Yamazaki, and M. Hamano: Proc. 26th
Int. Horticultural Congress, Toronto, Canada, 2002-8,(International Society of Horticultural Science, 2002),
p. 550.
3) T. Abe: Breed. Res. 5 Suppl. 2, 58 (2003).
4) D. Gray: J. Hortic. Sci. 50, 349 (1975).

National Institute of Vegetable and Tea Science149

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Mutation induction by heavy-ion beam in asparagus
P.-Y. Yun,∗ S.-Y. Kim,∗ A. Kanno,∗ T. Kameya,∗ T. Abe, Y. Miyazawa, H. Saito, and S. Yoshida
It has been reported that many types of mutation can be induced by heavy-ion irradiation, such as
dwarﬁsm, chlorophyll deﬁciency, sterility, and aberrance in ﬂoral organ. Floral mutations are very important in studying the molecular genetic mechanismof ﬂower development. Asparagus (Asparagus oﬃcinalis L.) is a dioecious plant and is the economicallymost important species in the genus Asparagus due
to its edible shoots. It has sex chromosomes called
X and Y, XY in male and XX in female.1) Male andfemale ﬂowers have both stamens and carpels during
the hermaphrodite developmental stages, whereas sex
diﬀerentiation appears to be the result of the selective abortion of stamens in female ﬂowers and carpels
in male ﬂowers. In this study, we attempted to induce
dioecious asparagus ﬂoral mutation by heavy-ion beamirradiation (C, N, Ne).
Asparagus (cv Mary Washington 500 W) was used as
the plant material. The seeds of asparagus were grownon the MS medium until germination. For N- and Neion irradiation, 15 germinated seeds were selected, andfor C-ion irradiation, 33 seeds were selected per individual experiments of irradiation. One week after germination, germinated seeds were irradiated with C, N
and Ne ions within a range of 5 to 50 Gray. The linear
energy transfer of the C, N and Ne ions corresponded
to 22, 30, 63 Kev/mm, respectively. Two days after
irradiation, irradiated seedlings were sown in the soil.
Survival rates are shown in Fig. 1. From these results, we suppose that Ne-ion beam has a stronger effect on the survival of asparagus than C- and N-ion
beams. The numbers of ﬂowering plants (male, female)and plants with modiﬁed ﬂowers are shown in the Table 1. We could obtain various ﬂoral modiﬁcations ofasparagus plants following the irradiation with heavyion beam (Fig. 2). Most plants did not have the same
ﬂoral modiﬁcations and only some ﬂowers are modiﬁed
in a plant. However, mutant BN27, which was inducedby N-ion (20 Gy) irradiation, had tepals that did notdehiscence, and no pollens were released even when
the ﬂowers became mature. These characteristics werestable for 3 years and the shape of all ﬂowers was iden-

Table 1. Observation of asparagus irradiated by heavy-ion
beam.
Ion

Dose

Number of flowering plants(Gy)
Control
Ne

N

C

0
5
10
20
50
5
10
20
50
5
10
20
50

Total
15
7
7
5
0
9
7
12
5
18
16
26
11

unflowering
0
0
1
0
0
1
0
4
1
4
2
7
2

Male
9
5
4
3
0
5
3
6
2
7
10
14
6

Female
6
2
2
2
0
3
4
2
2
7
4
5
3

Number of plants withmodified flowers
Total Male
Female
0
0
0
2
2
0
3
3
0
0
0
0
0
0
0
1
1
0
0
0
0
2
2
0
0
0
0
3
1
2
2
1
1
2
2
0
0
0
0

Fig. 2. Various asparagus floral modifications were obtained following C-, N- and Ne-ion beam irradiation.
The flower of BE05 has modified filaments, BE13 andBN20 have additional tepals, BC47 has flowers in aflower, and BN27 shows no opening of tepals and theirdehiscence and no release of pollens.

tical in mutant BN27. The dehiscence program probably requires the activation of many genes, including
those that encode hydrolytic enzymes required for cell
death, such as RNase, proteases, and cellulases.2–4) In
addition to the examination of pollen sterility, we arealso studying the relationship between the ﬂoral identity gene and ﬂoral modiﬁcation in asparagus mutant
BN27.
References

Fig. 1. Survival rates of asparagus plants irradiated with
C-, N- and Ne-ion beams.
∗

150

Graduate School of Life Sciences, Tohoku University

1) H. Löptien: Zeitschrift für Pflanzenzüchtung 82, 162(1979).
2) C. J. Keijzer: New Phytol. 105, 487 (1987).
3) L. L. Bonnrer and H. G. Dickenson: New Phytol. 113,
97 (1989).
4) E. del Campillo and L. N. Lewis: Plant Physiol. 99,
1015 (1992).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀect of heavy-ion beam irradiation on apple and Japanese pear
Y. Ito,∗ T. Abe, H. Saito, Y. Miyazawa, T. Takyu,∗ H. Yamanouchi,∗ and S. Yoshida
In fruit tree crops, mutation breeding has played an
important role in providing the speciﬁc characteristics
such as host-speciﬁc toxin disease resistance and fruit
maturity. It has been diﬃcult, however, to obtain mutants having other important agricultural characteristics by artiﬁcial induction. In recent years, the eﬀects
of heavy-ion beam irradiation in mutation induction
were reported to be diﬀerent from gamma-ray irradiation in ornamental ﬂower crops. Thus, the diﬀerencein the characteristics of mutation induction between
heavy-ion beam irradiation and gamma-ray irradiation
on tree fruit crops must be studied for the improvementof their mutation breeding. In this study, the eﬀects
of heavy-ion beam irradiations on apple and Japanesepear were investigated.
The dormant scions of apple (cv. Fuji) and Japanesepear (cv. Kosui) were used as the irradiation materials. The scions were cut to a length of approximately 6 cm and packed 7 each in polyethylene bags
and irradiated with carbon (12 C6+ , 135 MeV/u) andneon (20 Ne10+ , 135 MeV/u) ions. For adjusting thelinear energy transfer (LET) of both ions to approximately 8 mm in depth from the surface of the scions,an absorber was inserted before reaching the materials.
Keeping the 8 mm penetration, the maximum LET values at the surface of the materials were 42.0 keV/µm
for carbon ions and 84.1 keV/µm for neon ions. Fortynine scions were used for each dose exposure, and weregrafted onto the rootstocks in April 2002. Aodai No.3
was used as the apple rootstock and the seedlings ofPyrus betulaefolia as the Japanese pear rootstock. The
rate of new shoot grown (survived) scions and visible
mutation were investigated in the summers of 2002 and2003.
The survival rate decreased with increasing exposure dose. From the obtained dose-response curves(Fig. 1), the lethal dose 50 (LD50 ) for apple was estimated at approximately 18 Gy of carbon-ion irradiation and approximately 8 Gy of neon-ion irradiation.
LD50 for Japanese pear was estimated to be approximately 13 Gy of carbon-ion irradiation and approximately 8 Gy of neon-ion irradiation (Fig. 2). Abnor-∗

Fig. 1. Survival rate curves for ion beam irradiation onapple (cv. Fuji).

Fig. 2. Survival rate curves for ion beam irradiation on
Japanese pear (cv. Kosui).

mal shapes in the ﬁrst leaves were observed, but the
new leaves following them showed normal shapes inmost surviving plants. One variegated leaf (partly
chlorophyll deﬁcient) mutant of apple was observed
after 7.5 Gy of neon-ion irradiation. Further observations are required to determine visible mutation rateby heavy-ion beam irradiation in fruit tree crops, due
to possible chimeric structures. Using DNA analysis
and other methods, we are now selecting the mutants
which show self-compatibility or low tree height habit.

National Institute of Agrobiological Sciences151

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Eﬀects of heavy-ion beam irradiation on regeneration of shoots fromstem segments in spray-type chrysanthemum (Dendranthemagrandiflorum (Ramat.) Kitamura)
K. Suzuki,∗ Y. Takatsu,∗ T. Gonai,∗ Y. Miyazawa, H. Saito, T. Abe, S. Yoshida, and M. Kasumi∗
Mutation breeding has been used to improve withminimum changes original cultivars of various plant
species. Recently, heavy-ion beam irradiation was reported as an excellent breeding technique for ornamental plants, such as dahlia,1) verbena2) and chrysanthemum.3) Spray-type chrysanthemum is one of the major cut ﬂowers in Japan, and its various characteristics have been improved by conventional hybridization
methods. To change one or two characteristics, suchas ﬂower color and ﬂowering time, we attempted touse heavy-ion beam irradiation as a mutation breeding
technique. In the present study, we investigated theeﬀects of heavy-ion beam irradiation on the regeneration of shoots from stem segments in several varietiesof spray-type chrysanthemum.
Eighteen varieties cultivated in Ibaraki prefecture
were used for this experiment. Stem segments, 2 mmlong and vertically cut in half, were placed on a shootregeneration medium consisting of MS basal medium
supplemented with 2 mg/l IAA, 0.2 mg/l BA and solidiﬁed 4 g/l gellum gum. Three to 7 days after theculture, stem segments were irradiated with 12 C ion
beams (135 MeV/nucleon, LET 23 keV/µm) at doses

of 3, 7, 10, and 20 Gy. Fifty to 150 segments were
irradiated in each experiment. Thirty days after theculture, the number of regenerated shoots was counted
and the rate of shoot regeneration was calculated.
The frequency of shoot regeneration decreased withincreasing irradiation dose. No regenerated shoot wasobserved after 20 Gy irradiation except for ‘Chiyo.’
The signiﬁcant diﬀerence in half lethal dose (LD50 )was observed among varieties. The number of varieties
with an LD50 value of less than 3 Gy was four, thatwith 3–7 Gy was ﬁve, that with 7–10 Gy was seven,and that with 10–20 Gy was two (Table 1).
The LD50 value in 18 varieties of chrysanthemum
has become apparent in this experiment, and we are
now further investigating the characteristics such as
ﬂower color and ﬂowering time.
References
1) M. Hamatani et al.: RIKEN Accel. Prog. Rep. 34, 169(2001).
2) K. Suzuki et al.: RIKEN Accel. Prog. Rep. 35, 129(2002).
3) S. Nagatomi et al.: Breed. Res. 48 Suppl. 1, 220 (1998).

Table 1. Eﬀects of heavy-ion beam irradiation on the regeneration of shoots from stem segments invarieties of chrysanthemum.
Dose

Shoot regeneration rate (%)1)

Sakiko
54.5
1.0
0.0
0.0
0.0

1)

Subaru1)
36.3
10.5
3.0
1.1
0.0

Tomoshibi1)
59.0
18.7
4.3
0.0
0.0

Benikomachi2)
65.0
37.8
21.6
5.5
0.0

Duet2)
52.0
37.8
9.5
1.1
0.0

(Gy)
0
3
7
10
20

Korogi
47.9
5.8
6.3
0.0
0.0

0
3
7
10
20

Okinamaru2)
63.5
56.7
23.9
2.2
0.0

Hajime2)
25.0
26.3
7.1
2.2
0.0

Nonko2)
43.0
22.7
5.1
2.2
0.0

Beachball3)
81.0
–§
44.8
2.2
0.0

Kosuzu3)
30.0
–
15.8
0.0
0.0

Nagisa3)
20.6
7.1
12.9
0.0
0.0

0
3
7
10
20

Natsuhikari3)
76.0
65.1
55.7
16.5
0.0

Sasayaki3)
95.0
68.5
67.7
1.1
0.0

Satobue3)
72.0
67.0
34.2
40.0
0.0

Shirofune3)
38.2
63.4
29.3
1.4
0.0

Chiyo4)
100.0
–
–
93.7
16.4

Haruka4)
100.0
–
–
94.4
0.0

1) The LD50 value is less than 3 Gy, 2) 3–7 Gy, 3) 7–10 Gy, 4) 10–20 Gy, respectively.
§
The symbol ‘–’ indicates no data.
∗

152

Plant Biotechnology Institute, Ibaraki Agricultural Center

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Performance of strip Ge telescope for in-beam
γ-ray spectroscopy
M. K. Suzuki,∗ T. K. Onishi,∗ H. J. Ong,∗ H. Suzuki,∗ Y. Ichikawa,∗ N. Imai, N. Aoi,
H. Iwasaki,∗ and H. Sakurai∗
We are developing a strip germanium telescope1)(SGT) for in-beam γ-ray spectroscopy using fast
RI beams (β  0.4). Improvements have been madewith emphasis on the resolution and the signal-to-noise
ratio by modifying the signal readout of the SGT andapplying a Compton active shield. In this article, we
brieﬂy describe the design of the SGT. We also report
the performance study of the SGT using a 100 A MeV
18
O beam as well as using standard γ-ray sources, andthus demonstrate the usefulness of the SGT in in-beam
γ-ray spectroscopy.
The central design concept of the SGT is the combination of a high-eﬃciency detector and a positionsensitive detector. The schematic of the SGT is shownin Fig. 1. The high-eﬃciency detector is composed ofa 70 φ × 70 mm3 coaxial crystal. The position-sensitive
detector comprises a 50 × 50 × 20 mm3 planar crystal
with 25 2-mm-wide electrodes which can read out signals individually. The reaction position can be determined on the hit patterns of signals without the needfor analysing the pulse shapes. The position information is used for the Doppler-shift correction.
The intrinsic energy resolutions of individual strips
and coaxial crystals are typically 2.5 keV (FWHM) for
1408 keV γ-rays. As discussed in a previous report,1)
the resolution of the energy sum is typically 10 keV for
multihits events where two or more strips have signals.
The poor resolution of the multihit events is mainly
due to the crosstalk between neighbouring strips. The
crosstalk is not due to the so-called mirror charge effect. We thus added the readout for the total-charge
signal from the opposite side of the planar crystal.
As a result, the energy sum resolution was improved
to 6 keV. The energy resolution is suﬃcient for the

analyses of the Doppler correction, although it cannot
compete with the intrinsic resolution.
The basic performance characteristics of the SGT
were measured with standard γ-ray sources; 60 Co,
137
Cs, 133 Ba, and 152 Eu. The data were obtained witheach source placed 63 mm distant from the SGT. The
full-energy peak eﬃciencies of the SGT are shown in
Fig. 2 for the following cases: (A) a γ-ray is absorbed
in the planar crystal, (B) a γ-ray is Compton-scatteredin the planar crystal and then absorbed in the coaxial
crystal, and (C) both of (A) and (B). The errors were
determined to be typically 5% mainly from the uncertainties of the activities of the sources. The eﬃciencies
for 1 MeV γ-rays in cases (A), (B), and (C) were respectively 2.5 × 10−3 , 1.8 × 10−3 , and 4.3 × 10−3 . Theenergy resolutions are shown in Fig. 3. In each case,the overall resolutions of the SGT were dominated by

Fig. 2. Eﬃciencies measured in the following cases:(A) a γ-ray is absorbed in the planar crystal, (B) a γ-ray
is Compton-scattered in the planar crystal and thenabsorbed in the coaxial crystal, and (C) both of (A)and (B).

Fig. 1. Schematic of the telescope.
∗

University of Tokyo

Fig. 3. The energy resolutions.

153

the energy sum resolution.
To demonstrate the performance of the SGT foran actual in-beam experiment, we tested the SGT
in an inelastic scattering experiment of 18 O (E =100 A MeV, β = 0.42) with a 0.5-mm-thick Be target at
RIPS. The SGT is located perpendicular to the beamline and 63 mm distant from the target. In this study,
we applied the Compton active shield around the SGTwith an array of 30 NaI(Tl) detectors. The γ-ray emission angle for the Doppler shift correction was determined by measuring the directions of scattered particles and γ-rays. Two parallel plate avalanche counterswere placed 524 mm and 865 mm downstream of thetarget to determine the direction of scattered particles
and the beam-hit position at the target. The γ-ray direction was obtained from the γ-ray reaction positionin the SGT and the beam-hit position.
Figure 4 shows the spectra of γ-rays measured incoincidence with 18 O beams. The upper panel shows
the spectra in the laboratory frame and the lower one
shows the spectra in the moving frame with β = 0.42.
The hatched spectra are obtained under the condition
that the Compton active shield is not ﬁred. Note thatbackground levels due to Compton scattering were re-Fig. 4. Spectra of γ-rays measured in coincidence with18
O beams. The upper panel shows the spectra in thelaboratory frame. The lower panel shows the spectrain the moving frame with β = 0.42. The hatched spectra are obtained under the condition that the Compton
active shield is not ﬁred.

duced by a factor of 3.
In the moving-frame spectra, full-energy peaks areobserved around 1370 keV, 1980 keV, and 2180 keV,−−which correspond to the transitions 32 → 12 in 17 N,−+
2+ → 0+ in 18 O, and 12 → 12 in 17 O, respectively.
The excitation energies, the energy resolutions of theobserved peaks and the observed yields are summarisedin Table 1. The resolutions for 1–2 MeV γ-rays are determined to be aproximately 1.5%.
The Compton-suppression condition causes more reduction of the 2183 keV γ-ray yield compared withother γ-rays, because the γ-ray is part of the cas−+++cade process of 12 → 12 (2183 keV) and 12 → 52 g.s.
(870 keV) in 17 O. On the other hand, the peak around
870 keV cannot be observed clearly. The reason is that+the long lifetime of the 12 state ( 180 ps) broadens
the peak.
On the basis of the equation for the Doppler-shiftcorrection,
EDc = γ(1 − β cos θlab )Elabthe resolution of EDc is approximated using
2 
2

δElab
δEDc
=
EDc
Elab
 2
2  2βγ (β − cos θlab )δβ+
1 − β cos θlabβ2β sin θlab+(δθlab )2 .
1 − β cos θlab

References
1) M. K. Suzuki et al.: RIKEN Accel. Prog. Rep. 36, 156(2003).

Counts

154

FWHM

not suppressed

(2)

lab
Each variation is evaluated as δE
Elab  0.5% at aroundδβ2000 keV, β  2.0% due to the energy loss in thetarget, and δθlab  1–6% due to the width of a strip
and the thickness of the planar crystal. With all theseterms assigned to Eq. (2), the resolution was calculated
to be 1.3%, which is consistent with the measured valueof 1.5%.

Table 1. Properties of peaks in the spectra in the moving frame with β = 0.42.

Eγ (keV)(1)

suppressed

suppression loss

Transition1374

18 keV (1.3%)

388

287

26%

−
3−
→ 12 in 17 N
2

1981

30 keV (1.5%)

829

677

18%

2+ → 0+ in 18 O

2183

32 keV (1.5%)

219

122

44%

+
1−
→ 12 in 17 O
2

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Development of NaI(Tl) calorimeter for charged particles
M. Niikura,∗1 S. Shimoura,∗1 H. Iwasaki,∗2 S. Michimasa,∗1 M. Tamaki,∗1 S. Ota,∗3 and H. Baba∗4
A new NaI(Tl) calorimeter is developed in order tomeasure charged particles produced in nuclear reactions with RI beams. This calorimeter was designed forextending studies of unstable nuclei to a heavier mass
region, A = 50–100 at RIKEN projectile-fragment separators (RIPS). The detector is also aimed at measuring a particle at higher energies of more than a few
hundred MeV/nucleon at the RI-beam factory in thenear future.
The calorimeter consists of a maximum of 132
NaI(Tl) crystals with photomultiplier tubes (PMTs),
which are arranged in a 12×12 matrix except for three
crystals at each corner. Figures 1 and 2 show schematic
views of the calorimeter and each NaI(Tl) detector
setup, respectively. A NaI(Tl) crystal has a rectangular shape of 31 × 31 × 50 mm3 . The thickness of
50 mm is adopted for detecting light particles up to
approximately 100 MeV/nucleon or heavy ions up toa few hundred MeV/nucleon. The front face is covered with thin 7-µm-thickness Haver foil to reduce theFig. 1. Schematic view of NaI(Tl) calorimeter.

energy losses of charged particles which degrade the energy resolution. For higher count rate detection, each
PMTs in the center of the calorimeter (6 × 6 matrix)
is equipped with three-stage boosters. To measure accurate energies of charged particles and to minimize
the energy loss in ﬂight, the detector is operated in
vacuum. An O-ring between the light guide and theﬂange maintains the vacuum in a chamber.
In order to measure the energy resolution of NaI(Tl)crystal for charged particles, we performed a test experiment in the CRIB facility1) using the 25-MeV
α beam and the 90-MeV 14 N beam. The observed
energy resolution of a NaI(Tl) scintillator is mainly determined by the intrinsic energy resolution of the scintillators and the position dependence of the light collection in a crystal. To deﬁne a hit position of NaI(Tl)crystal, we used a 1-mm-φ collimeter for the α beam
and a tracking detector installed upstream of the detector for the 14 N beam. The energy resolutions at thecenter of the crystal were 0.60% and 0.91% for the αand 14 N beams, respectively. We also observed a difference between output pulse height from PMTs at thecenter and the corner of the crystal. The typical differences were 1–5% for the α beam and 2–3% for the
14
N beam.
We carried out an experiment to test the performance of the NaI(Tl) detector for higher energy bythe ∆E-E method using a combination of 3 × 3 matrix Si detectors (∆E) and the 6 × 6 matrix calorimeter (E). The result of the particle identiﬁcation has
been reported in Ref. 2. In this experiment, the intrinsic energy resolution of the scintillators was estimatedto be 0.8 ± 0.1% (σ) for the 560-MeV 23 F secondary
beam, and the position dependence of pulse height wasobserved as 0.1–0.3%. In the present estimation, we
took into acount the eﬀect of energy straggling in the
Si detector which was estimated as 0.42 ± 0.06% (σ).
The intrinsic energy resolution of the NaI(Tl) scintillator is so high that the energy straggling of the ∆E
detector determines the resolution of the particle identiﬁcation. The position dependence of the light collection in the NaI(Tl) crystal decreases in a higher energy
region.
References
1) Y. Yanagisawa et al.: RIKEN Accel. Prog. Rep. 34, 183(2001).
2) M. Tamaki et al.: CNS Annu. Rep. 2002, 76.

Fig. 2. Schematic view of the setup.
∗1
∗2
∗3
∗4

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

155

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RIKEN Accel. Prog. Rep. 37 (2004)

Development of triggerable focal plane detector with particle
identification capabilities
K. Itahashi, H. Geissel,∗1 A. Gillitzer,∗2 K. Gomikawa,∗3 R. S. Hayano,∗3 M. Iwasaki, K. Lindberg,∗4
M. Shindo,∗3 P.-E. Tegner,∗4 H. Weick,∗1 and T. Yamaguchi,∗1
We have been developing a new type of selftriggering detector with particle identiﬁcation capabilities. The detector TORCH will be used as the
focal plane detector for the spectroscopy experimentof η- and ω- bound 11 B nuclei in the nuclear reaction 12 C(d, 3 He). The experiment belongs to a seriesof spectroscopy experiments of meson-bound states innuclei1–3) and will be performed at the Fragment Separator (FRS) in the SIS-18 synchrotron of the GSI, Germany. In the experiment, the proton background rate
due to the incident deuteron breakup is expected tobe higher than 100 MHz at the dispersive focal plane,
whereas the signal 3 He rate is to be of the order of
1 Hz. Since no existing detector works under these
conditions, we developed a detector system which has
the proton rejection capability of > 108 with the 3 He
detection eﬃciency of > 90%. The detector will beplaced at the focal plane and has a position resolutionof < 2 mm (FWHM).
The largest diﬃculty in this experiment is the highbackground rate of protons. Since we have to employ ahigh intensity deuteron beam of 1 × 1011 /s and a thicktarget of 1 g/cm2 , the focal plane detector is exposed to〜100 MHz of protons. Our strategy to eliminate thebackground and to ﬁnd the signal 3 He is based on thediﬀerence of the Cherenkov emission angle. Since themagnetic rigidities of the background protons and thesignal 3 He are the same, they have diﬀerent velocities〜0.94c for proton and 〜0.87c for 3 He.
The detector mainly consists of a radiator, a segmented light guide, and 16 1-inch photomultipliers.
The horizontal acceptance is about 24 cm (See Fig. 1).
We have carefully chosen the radiator material of
UV Lucite (with the refractive index of 〜1.5). The
Cherenkov photons originating in the 3 He ions distribute to 3 or 4 cells of the light guide whereas thoseoriginating in protons are almost totally reﬂected at
the inner surface of the radiator and rarely reach thephotomultipliers. About 40 photons are detected by
the photomultipliers in the case of 3 He. Taking theweighted average of the detected photons, the incident
position of 3 He is measured with a resolution of 〜2 mm(FWHM).
We made a test experiment in the realistic environment of the FRS by employing deuteron and 12 C
beams. The tested points are (1) position resolu∗1
∗2
∗3
∗4

156

Gesellschaft für Schwerionenforschung, Germany
FZ-Jülich, Institut für Kernphysik, Germany
Department of Physics, The University of Tokyo
Department of Physics, Stockholm University, Sweden

Fig. 1. Schematic design of TORCH and a photograph of
its interior.

tion, (2) proton rejection capability and helium detection eﬃciency, and (3) time resolution. We installed a set of drift chambers with 2.5 mm cell size
before the TORCH detector (TORCH-S2) at the midfocus region of the FRS and another TORCH detector(TORCH-S4) at the end-focus region.
We correlated the drift chamber measured position
to the TORCH measured position and found satisfactory linearity of the position measurement. The
overall position resolution is estimated to be about
2 mm (FWHM) however small structures due to thesegmentation are still visible. With the backgroundproton rate of 〜100 MHz, TORCH detectors provided
suﬃciently clean trigger of about 1 kHz by the coincidence of the two TORCHs. The time resolution was
about 1 ns (FWHM), and by applying a cut in the TOF
spectrum between the mid- and end-focus, 3 He is identiﬁed almost free of background.
The test result shows the TORCH detector suﬃciently fulﬁlls our requirement. We improve its capability by adding high-voltage boosters in the photomultipliers to ensure the performance under a highbackground rate. Calibration measurement of the detector is being started in November 2003 and we willcomplete the ﬁnal preparation for the main experimentscheduled in January 2004.
References
1) H. Geissel et al.: Phys. Rev. Lett. 88, 122301 (2002).
2) K. Suzuki et al.: Phys. Rev. Lett. 92, 072302 (2004).
3) M. Iwasaki et al.: submitted to Phys. Lett. B.

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RIKEN Accel. Prog. Rep. 37 (2004)

Development of superconducting series junction detectors forheavy ions
H. Sato, M. Kurakado, Y. Takizawa, S. Shiki, and H. M. Shimizu
Series arrays of superconducting tunnel junctions(STJs) have a potential to realize a better energy resolution and linearity at an energy of several tens of MeV
in experiments which use heavy ions. The STJ is a kindof Josephson junction which has a sandwich structureof superconductor-insulator-superconductor thin layers. The typical size of a single junction is 110 µmφ.
Series arrays of STJs are fabricated on a sapphire substrate.
Ions are detected in the following manner with STJs.
Ions are implanted into the substrate using a beamcollimator. The deposited energy generates phonons.
The phonons distribute in the substrate and are thenabsorbed by STJ arrays which surround the detection
area. The absorbed phonons break Cooper pairs in the
superconducting layers of the STJs and a current signal
is produced by tunneling through a barrier.1,2) Because
the mean energy to break one Cooper pair is meV (forexample, 2.6 meV for Nb), a better energy resolution
than that obtained with semiconductor detectors suchas those of Si can be realized.3,4)
One of the suitable applications of our STJs is in theexperiment which searches for superheavy elements.
Usually Si detectors are used in these experiments tomeasure the energy of α particles in order to identify
the superheavy elements.5) However, if a spontaneousﬁssion event occurs, it is diﬃcult to measure its released energy (around 100 MeV) with a good energy
resolution and linearity because of the condensationof electron-hole pairs in the Si detector within a verysmall area. On the other hand, because our STJ arrays typically consist of thousands of junctions, the energy which is detected by each single junction is small.
Therefore, STJ arrays maintain a good energy resolution and linearity. We have started to develop arraysof STJs, and in this paper, we report on the present
status of the development of the detectors.
We adopt the series array of Nb-based STJs for thesedetectors and four series arrays are fabricated on a chip
whose size is 6 mm × 6 mm (Fig. 1).6) The structure of
the STJs is shown in Fig. 2. A center area of thechip (1.5 mm × 1.5 mm) is surrounded by STJ arrays
and phonons generated by energy deposition in thisarea are absorbed by them. The energy spectra of
α particles are obtained by summing signals from thefour STJ arrays.
We evaluated the characteristics of the detector byusing the 241 Am α source (5.486 MeV). An STJ chip
was attached on a copper plate which had a hole (1 mmin diameter) at the center of it. The copper plate wasmounted in a cryostat to be cooled to 0.35 K. The

Fig. 1. Photograph of a series-array STJ chip. Each array
contains 160 junctions.

Fig. 2. Schematic view of one element of the STJ arrays.

241

Am α source was also mounted in the cryostat andthe chip was irradiated by α particles from the backsurface of the chip (Fig. 3). Each STJ array was connected to the charge preampliﬁers independently. Only
coincident signals from the four STJ arrays are acquired as true events.
The accumulation of the sum of four signals from the
STJ arrays creates an energy spectrum of α particles.
However, the obtained pulse height of the signal depends on the detected position. This position dependence of pulse height broadens the peak width if wesum all events. To prevent this eﬀect, we introduced
the position correction method in data analysis.6) By
using the signals from array-1 and array-3 in Fig. 4, thex position of an event was deﬁned by x = x2 /(x1 +x2 ),and from the signals from array-2 and array-4, the157

Fig. 3. Experimental setup of the cryostat cold stage.

Fig. 5. Energy spectra of α particles (5.486 MeV) emitted
from 241 Am. (a) is obtained by summing signals fromfour STJ arrays. (b) is obtained after applying position
correction on (a). The energy resolution of (b) is 0.5%
in FWHM.
Fig. 4. Segmentation of the eﬀective area for the position
dependence correction analysis.

y position was deﬁned as y = y1 /(y1 + y2 ), where x1 ,y1 , x2 and y2 represent the pulse heights of the signals from array-1, array-2, array-3 and array-4, respectively. Then, we obtained a two-dimensional scatteredplot. The x–y scattered plot of the irradiated area
was divided into 45 × 45 cells and a spectrum was created using events Vcell in each cell (Fig. 4). The peak
position (Vpeak , cell ) of each spectrum and the maximum value (Vmax ) among Vpeak , cell are deﬁned. Thenthe correction coeﬃcient of each cell was calculated as
R = Vmax /Vpeak ,cell and the spectrum was rebuilt as


Vcell
= R × Vcell . By summing Vcellof all cells, we
obtained the corrected energy spectrum. In this correction, actually, the data of the cells which have lessthan 10 events were not used for rejecting any inaccuracy of the deﬁnition of Vpeak , cell .
Figure 5 (a) shows the energy spectrum of the sumof the signals from the four arrays without correction.
On the other hand, Fig. 5 (b) shows the energy spectrum obtained by applying the position correction. By
comparing these two spectra, we can ﬁnd that the peakwidth was sharpened by the correction. As a result, we
obtained an energy resolution of 0.5% in full width at158

half maximum (FWHM).
We are also testing larger chips whose size is 12 mm×
12 mm and eﬀective area is 8 mm × 8 mm. With thischip, we obtained a resolution of 3.5% in FWHM for
α particles from 241 Am. Therefore, in order to improvethe energy resolution, detailed studies on the relationships among the phonon speed in the substrate, sizeof the eﬀective area, formation of STJ arrays and substrate materials are required.
References
1) M. Kurakado, A. Matsumura, T. Takahashi, S. Ito, R.
Katano, and Y. Isozumi: Rev. Sci. Instrum. 62, 351(1991).
2) M. Kurakado, D. Ohsawa, R. Katano, S. Itoh, and Y.
Isozumi: Rev. Sci. Instrum. 68, 3685 (1997).
3) M. Kurakado: Nucl. Instrum. Methods 196, 275 (1982).
4) M. Frank, C. A. Mears, S. E. Labov, F. Azgui, M. A.
Lindeman, L. J. Hiller, H. Netel, and A. Barfknecht:
Nucl. Instrum. Methods Phys. Res. A 370, 41 (1996).
5) Yu. Ts. Oganessian et al.: Phys. Rev. C 63, 011301(R)(2000).
6) M. Kurakado, S. Kamihirata, A. Kagamihata, K.
Hirota, H. Hashimoto, H. Sato, H. Hotchi, H. M.
Shimizu, and K. Taniguchi: Nucl. Instrum. Methods
Phys. Res. A 506, 134 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Performance study of the big ion chamber
K. Sugawara,∗1 K. Kimura,∗2 T. Akiyama,∗1 D. Fang, M. Hosoi,∗1 T. Izumikawa,∗3 T. Ohnishi, T. Ohtsubo,∗3
A. Ozawa, W. Shinozaki,∗3 T. Suzuki,∗1 A. Takisawa,∗3 C. Wu, Y. Yamaguchi,∗3 and I. Tanihata
We have reported the performance of the big ion
chamber (IC), which is used to identify the atomic
number (Z) of secondary beams under the high counting rate of up to 500 kHz.1,2) This IC will be used tosearch for the proton halo in 23 Al at the second focal
plane (F2) of RIPS, instead of the conventional SSD,
where the high counting rate of several tens of kHz is
predicted. To use the IC at RIPS, we enlarged the IC
size, 780 (length) × 376 (width) × 330 (height) mm3 ,and entrance window, 200 mm in diameter. In this paper, we report the result of a test experiment to study
the dependence of energy resolution on position as wellas on counting rate.
The experiment was carried out at the E1C beamline. The newly constructed big IC ﬁlled with P-10
gas at a pressure of 9.88 × 104 Pa (741 Torr) was located just behind the F2 vacuum chamber. The anode voltage was set at 500 V. A plastic scintillation
counter for the time-of-ﬂight (TOF) measurement was
put close to the IC. An SSD was used for particle identiﬁcation under the lower counting rate less of thana few kHz. In addition, a PPAC and two PPACs
were placed at F1 and F2 foci, respectively, to monitor
the beam proﬁle. We used secondary beams produced
through the fragmentation of the 40 Ar primary beam
(95 MeV/nucleon) impinging on a Be production target. The particle was identiﬁed by the conventional
method to measure the time-of-ﬂight (TOF), the energy loss (∆E) and the magnetic rigidity for each fragment. A typical Z distribution obtained by the IC isshown in Fig. 1.
The position dependence of the energy resolution(∆Z/Z, where ∆Z denotes FWHM of the peak in

Fig. 1. Z spectrum on A/Z = 2 obtained from the IC.
The horizontal axis is the atomic number (Z) of thefragment, and the vertical axis is the counting number.
The counting rate was 666 Hz.
∗1
∗2
∗3

Saitama University
Nagasaki Institute of Applied Science
Niigata University

the atomic-number spectrum) was measured by moving the big IC perpendicular to the beam axis, either by±50 mm in the horizontal or by +50 mm in the vertical direction. As seen in Fig. 2 (a), the Z-resolution at
oﬀ-centers, 50 mm shifted horizontally and vertically,
diﬀers by 0.03% and 0.06%, respectively, from the Zresolution measured at the center. Therefore, we conﬁrmed that the big IC does not have any signiﬁcant
position dependence.
The rate dependence of ∆Z/Z was also examined bychanging the beam intensity from 666 Hz to 330 kHz.
Figure 2 (b) shows the Z-resolution for Z = 8, 10, and
14 fragments as a function of counting rates. As seen in
Fig. 2 (b), the diﬀerence in ∆Z/Z obtained at 666 Hz
and that at 34 kHz is less than 0.1%. However ∆Z/Z at
330 kHz is worse by 0.5% compared to that at 666 Hz.
The behavior of ∆Z/Z against the high rate of morethan several ×104 Hz may be attributed to the properties of the counting gas, such as the drift velocity ofelectrons and ions. This result shows the same trendwith that of the previous experiment.1,2) Further studies are necessary.
(a)

(b)

Fig. 2. (a) Z resolution of IC as a function of IC position relative to the beam. The triangle, square, andcircle indicate the resolution for Z = 6, 10 and 14, respectively. Open symbols indicate resolutions obtainedwith the position setting of +50 mm vertically. The
positive value on the horizontal axis corresponds to theright-hand side of the geometry, viewing from upstreamof beam line. (b) Z resolution of IC as a function ofcounting rates. The counting rate was changed from666 Hz to 330 kHz. The closed triangle, open squareand closed circle indicate the data for Z = 8, 10 and
14, respectively.

References
1) Y. Yamaguchi et al.: RIKEN Accel. Prog. Rep. 36, 161(2002).
2) K. Kimura et al.: to be published.

159

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RIKEN Accel. Prog. Rep. 37 (2004)

Design of 4-layer magnetic shield for spin maser experiment
A. Yoshimi, K. Asahi, S. Emori,∗ and M. Tsukui∗
Nuclear spin precession sometimes serves as an exclusive tool for fundamental physics studies such as
the search for the T-violating electric dipole moment(EDM) in nuclei. The developments of laser-polarized
noble gas nuclei and the self-sustained nuclear spinmaser with the hyperpolarized nuclei are in progress.1)
The nuclear spin maser, where the spin precession iscontinued beyond the intrinsic transverse relaxation
time by the feedback system, is advantageous for detecting the small frequency shift of the spin precessionthat is required for EDM search.
In such experiments homogeneity and stability of themagnetic ﬁeld are important for observing the spin
precession phase with high accuracy. We designed a
4-layer magnetic shield for suppressing the ﬁeld penetration from the external environment. The shield iscylindrical for performing the maser experiment. The
noble gas sample conﬁned in a glass cell, an oven chamber for optical pumping, and a solenoid coil are to belocated inside the shield.
The shielding factor is mainly determined by permeability and the cylinder’s geometry. The shield wasmade of Permalloy (JIS mark: PC, 1.5 mm thickness)
which has a high initial permeability of approximately
1 × 105 . The shielding factor strongly depends on theratio between length (l) and diameter (d) of the cylinder. The shield’s geometry is shown in Fig. 1. Eachl/d ratio is chosen to be approximately 4.0. In orderto suppress the ﬁeld penetration from the open end of
the cylinder, a large value of l/d is advantageous. On
the other hand, ﬁeld penetration from the middle areaof the cylinder’s shell into the shielded area increases
when the cylinder becomes long. The l/d ratio of 4.0
is considered to be most appropriate for the maximum
axial shielding factor.2)
The existing theory for the magnetic shielding factor only describes the transverse shielding factor of
inﬁnitely long cylindrical shield. Therefore, the estimation of shielding was numerically calculated using
the two-dimensional electromagnetic ﬁeld calculation

code POISSON. The calculated ﬁeld lines are shownin Fig. 2. The calculated ﬁeld strength in the centerof the shield in the presence of an external magnetic
ﬁeld of 30 µT (equivalent to the earth’s magnetic ﬁeld
strength) is summarized in Table 1. The estimatedshielding factors reach 4 × 10−4 and 3 × 10−7 for theaxial and transverse directions, respectively.
The 4-layer shield was constructed and the shielding eﬀect was roughly measured with a ﬂux gate magnetometer. The measurement was performed for theexternally applied ﬁeld of Bext = 30 µT. Since theshielding factor is large for the constructed shield,
the residual magnetic ﬁeld inside the 4-layer shield
was below the detection limit (< 1 nT). The residualﬁelds were also separately measured for each singlelayer shield, and the measured ﬁelds for each shieldranged from 240–300 nT in the transverse direction of
the cylinder and from 900–1000 nT in the axial direction. These values agreed with those calculated by
POISSON within a factor of 2. The discrepancy between the measurements and the calculation is considered to come from ﬁnite residual magnetization in
the Permalloy and from a slight ﬁeld penetration fromjoint points of cylindrical shields. We expect that theﬁeld ﬂuctuation due to the external magnetic ﬁeld
can be suppressed to smaller than 10 pT.3) We are
now preparing the equipment combined with a highprecision magnetometry for the spin maser experiment.

Fig. 2. Calculated magnetic field flux. (a) Transverse field.
(b) Longitudinal field.

Table 1. Calculated field strength in the shield center.
direction/layer
axial (nT)transverse (nT)

1
500
200

1+2
100
5

1+2+3
30
0.2

1+2+3+410
0.01

References

Fig. 1. Geometry of the 4-layer cylindrical magnetic shield.
∗

160

Department of Physics, Tokyo Institute of Technology

1) A. Yoshimi and K. Asahi: RIKEN Accel. Prog. Rep.
36, 173 (2003).
2) E. Paperno, H. Koike, and I. Sasada: MAG-99-28, 7(1999).
3) A. Yoshimi, K. Asahi et al.: Phys. Lett. A 304, 13(2002).

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RIKEN Accel. Prog. Rep. 37 (2004)

Detector R&D for the beta neutrino correlation experimentJ. Murata,∗1 K. Asahi, T. Haseyama, D. Kameda,∗2 K. Kurita,∗1 H. Miyoshi,∗2
K. Shimada,∗2 H. Ueno, H. Watanabe, and A. Yoshimi
Next generation precision beta decay experiments
aiming test of the standard model using stopped
RI beams which is going to be produced with huge
intensity at the RIKEN-RIBF is presented. Appearance of some physics beyond the standard model is predicted at just below the current experimental sensitivities in the beta decay observables by SUSY or GUT.1)
The prime motivation of the present measurement isto reach the highest sensitivity aiming the discovery of
the physics beyond the standard model.2,3)
The present schematic design of the experimental
setup to measure beta neutrino angular correlation andto search time reversal symmetry violation, is shown in
Fig. 1. In-ﬂight beta decay from the stopped RI-atomic
beam4) is going to be observed. As shown in Fig. 1, thedetector setup consists of beta tracking detectors andposition sensitive microchannel plate (MCP) recoil ion
detectors. Another possible choice for the secondary
electron multiplier is microsphere plate, however, we
use MCP as the ﬁrst prototype device. The beta momentum vector is determined using the planar drift
chamber and scintillation counters. The decay vertex position is deﬁned using the beta-ray straight-line
track information and the atomic beam proﬁle. The
vertex position resolution is dominated by the wide
atomic beam proﬁle of around a few mm. For the recoil ions do not have suﬃcient kinetic energy to hit
the MCPs, a static electric ﬁeld is applied to accelerate the recoil ions before hitting the MCPs. Usinga cross-wire helical delay line anode, two-dimensional

hitting position information for the recoil ions on the
MCPs can be obtained. The initial ion position at the
ground-level grid, just before entering the accelerationﬁeld, can then be extracted using a particle trajectory
calculation inside the electric ﬁeld. Together with the
decay vertex information, the recoil ion track in thefree volume can be determined. The kinetic energy of
the recoil ion can be extracted by a TOF measurement
between the electron hitting timing and the MCP hitting timing.
Most of the previous and ongoing beta neutrino
angular correlation experiments are based on single
measurements of the recoil energy spectra using ion
traps.5–7) The disadvantage of the present in-ﬂight
measurement is the low statistics and the diﬃculty of
the coincident measurement with the beta particle. On
the other hand, our advantage is the high sensitivity on
the so-called a parameter (beta neutrino angular correlation coeﬃcient) thanks to the direct determinationof the beta and neutrino emission angle in the coincident experiment. In Fig. 2, event-generator-based
simulation results are shown, comparing the expected
deviation from a = 1 to a = 0.9, on the single recoil
ion energy spectra and the beta neutrino relative angular distribution with same statistics of 105 events.
Figure 2 shows that the direct measurement of the relative emission angle enables a highly sensitive angularcorrelation coeﬃcient measurement.
A prototype position-sensitive recoil ion MCP detector using a helical cross wire delay line anode has beenFig. 1. Detector setup for the beta neutrino angular correlation measurement.
∗1∗2

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

161

Fig. 2. Simulation results comparing single recoil ion measurement and direct emission angle measurement.

built without the acceleration ﬁeld, showing a position resolution of around 100 microns, which is sufﬁciently good for the current purpose. A study of
two-dimensional position detection and overall position resolution combined with the acceleration ﬁeld isunder way. The fabrication of the planar drift chamber with delay line readout is already started, and is
expected to be completed and tested within 2003. Detector and RI-atomic beam facilities will be completed
before the ﬁrst RIBF beam by utilizing the current
RIKEN accelerator, and we will start data production
at RIBF from its initial stage.

162

References
1) B. R. Holstein and S. B. Treiman: Phys. Rev. D 66,
010001 (2003); H. Abele: Nucl. Instrum. Methods Phys.
Res. A 440, 499 (2000).
2) J. Murata et al.: RIKEN Accel. Prog. Rep. 34, 246(2001) and references therein.
3) J. Murata: to be published in Czech. J. Phys. 53 (2003).
4) H. Miyoshi et al.: RIKEN Accel. Prog. Rep. 36, 193(2003) and the references therein.
5) J. S. Allen et al.: Phys. Rev. 116, 134 (1959).
6) C. H. Johnson et al.: Phys. Rev. 132, 1149 (1963).
7) E. G. Adelberger et al.: Phys. Rev. Lett. 86, 1299
(1999).

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RIKEN Accel. Prog. Rep. 37 (2004)

Performance of a multiple-reflection time-of-flight mass spectrometer
Y. Ishida, M. Wada, Y. Matsuo, I. Tanihata, A. Casares,∗ and H. Wollnik∗
In order to determine nuclear binding energies of short-lived nuclei, we have developed
a multiple-reﬂection time-of-ﬂight mass spectrometer(MR-TOF).1) In the MR-TOF, ions are repeatedly reﬂected between two coaxially arranged electrostatic ion
mirrors. These ions are passed up to 700 times between the ion mirrors. Within this system, the overall
ion ﬂight time can be 3 ms and the overall ﬂight distance more than 100 m. There are no intensity losses in
the grid-free ion mirrors. The transmission is limited
only by angle scattering of the ions by residual gas
atoms. The achieved mass resolving power exceededm/∆m ≈ 40,000.
The CO-N2 -C2 H4 mass triplet is used to check theaccuracy of the MR-TOF. This triplet contains ionsof masses mCO = 27.994915 u, mN 2 = 28.006148 u,
mC 2H 4 = 28.031300 u and thus features mass diﬀerences of mCO − mN 2 ≈ 0.011233 u ≈ 10.4638 MeV/c2
and mC 2H 4 − mN 2 ≈ 0.025152 u ≈ 23.4290 MeV/c2 .
The obtained spectrum in Fig. 1 shows a massresolving power of m/∆m ≈ 25,000 for ions that
had undergone 245 reﬂections corresponding to theﬂight time of about 905 µs. Using the masses of CO
and N2 as reference masses, the mass of C2 H4 is
28.031276(42) u which diﬀers from the correct value
by 22 keV/c2 or 0.85 ppm. Also, from the masses
of CO and C2 H4 that of N2 was determined as
28.006153(19) u which is 5.1 keV/c2 or 0.2 ppm larger
than the correct value. Naturally, the value determinedby interpolation is more accurate and precise than thatby extrapolation. It can be seen that the relative positions of the reference peaks to the unknown one in the
spectrum are important for accurate and precise mass
determination, as well as the resolving power.

Fig. 1. The mass spectrum of a mixture of CO, N2 andC2 H4 as obtained in the MR-TOF. The mass-resolving
power of m/∆m ≈ 25,000 in FWHM is achieved after
245 reﬂections in this spectrum. Assuming two of thesemasses to be known, we can determine the third one
with an accuracy of < 1 ppm.
∗

Oak Ridge National Laboratory, USA

A large variety of exotic nuclei can be produced andseparated in-ﬂight using the RIKEN projectile fragment separator (RIPS) or Big RIPS in the RIKEN
RI-beam factory project. Those energetic ions are injected into an RF ion-guide system and are thermalized.2) The ions are extracted from this system andguided to the MR-TOF for mass spectrometry. We
plan to collect the ions in a bunching device before
they are injected to the MR-TOF. In such a setup
the used electron-impact ion source will be replaced
by a small Paul trap.
Ions must be well conﬁned and well cooled before injection to the MR-TOF, otherwise the energy spread of
injecting ions becomes wider. The MR-TOF itself cancompensate such an energy spread up to the second
order when an appropriate setup is selected,3) but not
the higher order eﬀect. If the energy spread is larger
than several percent, the higher order eﬀect is not negligible, so that the mass-resolving power becomes lower
than 20,000. Also, the density of the buﬀer gas into
the Paul trap is important. If we inject ions continuously into the trap, dense buﬀer gas is necessary because ions must lose their energy within the length of
the trap. However, the dense gas causes energy lossof the extracting ions due to gas collision. Therefore,a pulsed ion beam is necessary for eﬃcient transport tothe trap. While the pressure in the MR-TOF must be
kept lower than 10−7 mbar, the cooling of ions within
the trapped period of ∼ 1 ms requires the pressure of
the buﬀer gas to be at least 10−3 mbar. As a result,the mean free path is about ten times larger than thetrapped region.
A quadratic Paul trap and a linear Paul trap are
considered for the device mentioned above. The linear
Paul trap has a greater phase-space acceptance and ismuch easier to operate. For example, the RF applied
to the ring electrode of the quadratic Paul trap results
in a time-varying force along the longitudinal axis or
the axis along which the ions are injected and subsequently extracted. Ions must be injected carefully into
the Paul trap by synchronizing the injection with the
RF applied. However, the RF applied to the rods of thelinear trap creates no such time-varying force along thelongitudinal axis, and therefore the RF-phase criterion
is not critical. Clark et al. compared the linear trapwith the quadratic trap as the collecting and coolingdevice before ions are transported to a Penning trap.4)
The typical eﬃciency with the quadratic trap was 15%,
whereas, they obtained 80% or better with the linear
trap.
We construct a linear Paul trap and investigate its
matching to the MR-TOF and the behavior of the ionsin the linear trap are calculated by SIMION 7.5) The

163

calculated ion trajectory in the linear trap is shown in
Fig. 2. Such a calculation is useful for determining theappropriate parameter. We ﬁnd that it is possible toload the pulsed ions from the RF ion-guide system effectively by switching the voltage of the endcap of the
trap. As the axial length of the trap becomes longer,
the acceptance of the pulsed ion beam becomes higher,
however, the mass-resolving power of the MR-TOF becomes lower. Therefore, we design a 2-stage linear trap
to separate the loading part and the extraction part.
References

Fig. 2. The ion trajectory in a linear Paul trap calculated
by SIMION 7. The ion was trapped by switching thevoltage of an endcap electrode (not shown).

1641) Y. Ishida et al.: RIKEN Accel. Prog. Rep. 36, 184(2003).
2) M. Wada et al.: Nucl. Instrum. Methods Phys. Res. B
204, 570 (2003).
3) H. Wollnik: J. Mass Spectrom. 34, 991 (1999).
4) J. Clark et al.: Nucl. Instrum. Methods Phys. Res. B
204, 487 (2003).
5) D. A. Dahl: Int. J. Mass Spectrom. 200, 3 (2000).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Numerical investigation of the “fair-wind gas cell” concept forslow RI-beam production at RIKEN
M. Wada and V. L. Varentsov∗
A slow-RI-beam facility is planned as one of the primary facilities in the RIKEN RI-beam factory. Developments for the eﬃcient and fast deceleration and cooling of energetic RI beams provided by a projectile fragment separator are under way using a large gas catcher
cell and an rf ion guide.1) They have achieved an overall eﬃciency of 5% for collecting a 100 MeV/nucleon
8
Li beam,2) which corresponds to an extraction eﬃciency of 40%. It is hard to increase the eﬃciency beyond 10% since the stopping capability of the present
gas cell, which is 2 m in length and ﬁlled with 133 mbar
He gas, is limited to ∼12% for such light nuclei. The
maximum gas pressure in the cell is restricted by thepossible amplitude of the rf gradient electric ﬁeld applied to the rf ion guide.
A novel concept, named the fair-wind gas cell, hasbeen recently proposed,3,4) in which the transport ofions through the stopping cell is carried out by a gas
ﬂow without using any electric ﬁelds. This is similar
to an original IGISOL scheme, but the extremely highgas ﬂow rate here enables the use of 1 bar gas pressure
and provides fast ion transport through the stoppingcell even if its length is as large as 1 m. The collectionof ions behind the exit hole of the cell, where the gaspressure is still nearly as high as that inside the stopping cell, should be performed using an rf funnel. It
is not obvious that possible rf gradient electric ﬁelds
applied to the rf-funnel will provide a suﬃcient barrier
force for transporting ions to the entrance of a miniature supersonic nozzle. That is why we have performed
detailed ion trajectory simulations, whose results arepresented in this short report.
The principle scheme of the fair-wind gas cell combined with an extraction rf funnel5) is shown in Fig. 1.
The large axial symmetric gas cell consists of a stopping chamber and an extraction chamber, which areconnected through a central hole. An energetic RI
beam enters through an entrance window into the stopping chamber, where the ions are decelerated and thermalized in a buﬀer gas. The fair-wind gas cell concept
is based on the use of an intensive compulsory buﬀer
gas ﬂow through the cell combined with an rf funnel.
For this purpose, there are annular slits on the side surfaces of the stopping and extraction chambers, which
serve as the gas inlet and outlet, respectively. An intensive compulsory gas ﬂow through the cell is maintained by the pressure diﬀerence between these slitsthat is maintained by pumping. Since the ﬂow rateof high-purity helium is extremely high (typically, it is10–30 bar l/s), the gas inlet and outlet should be con∗

Radium Institute, Russia

Fig. 1. Principle scheme of the fair-wind gas cell and extraction rf-funnel system. The gas cell sizes, which weused in simulations, are as follows: the length of the
stopping chamber is 1000 mm; the length of the extraction chamber is 100 mm; the inner cell diameteris 150 mm; the widths of the inlet and outlet slits are
20 mm; the half-angle of conical part of the stopping
chamber is 45o and the stopping chamber exit hole diameter is 16.6 mm.

nected to a closed recycling system through an oil-freepump and a gas-puriﬁcation system.
The stopped ions are transported by the gas ﬂow
through the stopping chamber into the extraction
chamber, where the rf funnel is placed on the axis
between the stopping chamber exit hole and the supersonic nozzle (see Fig. 1). Most of the buﬀer gas
ﬂowing through the cell is evacuated from the extraction chamber through the outlet slit (see Fig. 1) passing through the gaps between rf-funnel rings when therepelling force due to an rf ﬁeld gradient conﬁnes theions inside this funnel. It should be emphasized that
there is no need here for any additional DC ﬁeld todrag the ions through the buﬀer gas, as it is used inconventional gas cell techniques. Then the ions arecarried by a supersonic gas jet out of the nozzle into
the next rf funnel, where a high-speed buﬀer gas ﬂow
eﬀectively transports the ions through this second rf
funnel into a high-vacuum region.
The operation of the fair-wind gas cell + extraction
rf-funnel system was investigated by detailed numerical simulations. First, gas dynamic simulations were
performed for both the fair-wind gas cell at 1 bar helium buﬀer gas pressure and the extraction rf funnel
at 4 mbar background gas pressure (the computer codeused is described in Ref. 6. Then the results of thesegas dynamic calculations were incorporated into theMonte Carlo code1) for microscopic ion-beam trajectory simulations under the combined eﬀect of the buﬀer
gas ﬂow and electric ﬁelds of the rf funnels.
The results of the gas dynamic simulations of thehelium gas ﬂow inside the fair-wind gas cell are shown165

in Fig. 2. The rf funnel consists of 152 thin metalring electrodes separated by gaps. The thicknesses of
the rings and gaps are 0.3 mm (only every 5th ringis shown in Fig. 2). The entrance and exit rf-funnel
apertures are 16.6 mm and 1.2 mm, which correspondto the diameters of the stopping chamber exit hole andthe entrance aperture of the supersonic nozzle, respectively. For simulations, we used the same convergingdiverging nozzle geometry as that used in Refs. 3 and4. The axial gas velocity in the cylindrical part of the
stopping chamber is approximately 3.5 m/s. The gas
velocity is considerably increased in the conical partof the stopping chamber and continues to increase inside the rf funnel (approximately 160–200 m/s) down
to the supersonic nozzle entrance. The inlet gas pressure is 1.0 bar, while the outlet gas pressure is 0.96 bar.
The total gas ﬂow rate through the fair-wind gas cellis 26.5 bar l/s. At the same time, the gas ﬂow rate
through the nozzle is only 129 mbar l/s.
The results of the Monte Carlo simulation are shownin Figs. 3 and 4. Figure 3 shows typical ion trajectories in the rf funnel and Fig. 4 shows the transmission
eﬃciencies of 8 Li and 133 Cs ions, which we have cho-

Fig. 2. He gas velocity ﬂow ﬁeld inside the fair-wind gas
cell. Arrowhead lines are gas streamlines. Details arein the text.

Fig. 4. Transmission eﬃciencies of 8 Li and 133 Cs ionsthrough the rf-funnel of the fair-wind gas cell as functions of rf frequency and the rf amplitude applied to thering electrodes.

sen as representatives of light and heavy ions, throughthe rf funnel of the fair-wind gas cell as functions of
the rf frequency and the rf amplitude applied to thering electrodes. One can see that, at adequate rf voltages applied to the funnel electrodes, most of the ions
are transported through the funnel even at 1 bar buﬀer
gas pressure. This occurs because an eﬀective repelling
force due to the rf gradient electric ﬁeld in this case islarger than the dragging force of the buﬀer gas ﬂowing
out through the gaps between the funnel rings.
The presented numerical simulations support thefair-wind gas cell concept. Further investigations
should be performed to clarify some other possible
problems, such as space-charge eﬀects in the stopping
chamber at a high RI-beam intensity. A real experiment using a proof-of-principle model is also plannedat the present RIKEN facility.
References

Fig. 3. Typical ion trajectories in the rf funnel of the fairwind gas cell.

1661) M. Wada et al.: Nucl. Instrum. Methods Phys. Res. B
204, 570 (2003).
2) A. Takamine et al.: RIKEN Accel. Prog. Rep. 37, 173(2004).
3) V. L. Varentsov and D. Habs: Nucl. Instrum. Methods
Phys. Res. A 496, 286 (2003).
4) V. L. Varentsov and M. Wada: Proc. COOL03, to be
published in Nucl. Instrum. Methods Phys. Res. B.
5) V. L. Varentsov: SHIPTRAP Collaboration Workshop,
Mainz, Germany, 2001-3, unpublished.
6) V. L. Varentsov and A. A. Ignatiev: Nucl. Instrum.
Methods Phys. Res. A 413, 447 (1998).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

FOV and angular response of the APEX onboard
French-Brazilian microsatellite
H. Miyasaka,∗1 H. Kato, K. Makishima, U. B. Jayanthi,∗2 T. Tamagawa, K. Yamaoka,∗3 I. Sakurai, S. Hong,∗4
M. Nakajima,∗5 M. Kohama, Y. Terada, J. Kotoku,∗6 and Y. Uchihori∗7
We report on the angular response of the APEX onboard the French-Brazilian microsatellite with beam
calibration results. Since preliminary beam calibration results, APEX features and observation objectives
have been reported previously,1–3) we will not describe
their details here. Note that the schedule for launchinghas been postponed to mid-2006 instead of the end of
2003 because of a recent Brazilian rocket accident.
The APEX is a radiation monitor, consisting of only
four PIN diodes (D1–D4), that observes alpha, protonand electron ﬂuxes around several MeV at the altitudeof ∼750 km of the equatorial region. The APEX has a±15 degrees opening angle of view (FOV). Even witha shield to maintain this FOV, a high-energy particle
can easily penetrate the detector through the shieldfrom an unexpected direction. To avoid this, we useda multithreshold discriminator and coincident logic.
From the FOV and the energy responses, we determined the geometric factor (G-factor; cm2 ·sr) of the
APEX to be ∼0.0076 cm2 ·sr by Monte Carlo simulation. The G-factor is on important charactereistic ofthe detector for determining ﬂuxes of cosmic rays inreal observation. We examined this from accelerator
experiments. However, the particle from the accelerators has a parallel direction and not an isotropic distribution; therefore, we examined the angular energy
responses and angular particle detection eﬃciency separately. We performed beam experiments at E3A facilities in RIKEN Ring Cyclotron with 135 MeV/nucleon
H+
2 . Figures 1 and 2 show examples of the results forangular energy responses and detection eﬃciency, respectively.
Figure 1 shows a normalized deposited energy of detector 2 (D2) at each incidence angle. This has beennormalized at the deposited energy at 0◦ . Note thatthe error has been estimated from the standard deviation of the D2 output. This result can be simply expressed as 1/ cos(x) with incidence angle x by a dashline in Fig. 1. Even from this simple model, we can see
a quite good agreement with the experimental results,
however, there are some systematic deviation at large
incidence angles. This is caused by an energy increaseat the detector or Al window.
Figure 2 shows the angular eﬃciency as the count
∗1
∗2
∗3
∗4
∗5
∗6
∗7

University of Delaware, USA
Instituto Nacional de Pesquisas Espaciais, Brazil
Aoyama Gakuin University
Saitama University
Nihon University
University of Tokyo
National Institute of Radiological Sciences

Fig. 1. D2 deposited energy at each incidence angle normalized at 0 degrees. The dashed line represents the
expected deposited energy.

Fig. 2. D4 count rate relative to the input count rate ateach incidence angle. The dashed line represents the
response calculated from the APEX geometry.

rate of D4 relative to the input count rate at each
incidence angle. The dash line represents the eﬃciency
calculated from the APEX detector’s geometry. Alsofrom this result, we can see a good agreement between
our experimental and calculated results.
Finally from these results, we conﬁrm the expected
performance of the APEX. Using this G-factor, forexample, we can estimate the count rate of proton at
the edge of SAA (South Atlantic Anomaly as a wellknown radiation belt region) as ∼100 counts/sec.
References
1) U. B. Jayanthi: submitted to Adv. Space Res.
2) T. Kohno et al.: RIKEN Accel. Prog. Rep. 31, 168(1998).
3) H. Miyasaka et al.: RIKEN Accel. Prog. Rep. 36, 170(2003).

167

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Accelerator test of charge particle detectors fora satellite instrument STEP-F
O. Dudnik,∗1 T. Goka,∗2 H. Matsumoto,∗2 M. Fujii,∗3 V. Persikov,∗1 T. Malykhina,∗1 and H. KatoJapanese-Ukrainian collaboration in space research
includes the testing and calibration of detectors andanalogue electronics of the STEP-F instrument.1) It
is a satellite spectrometer-telescope for high-energy
charged particles, which was developed in Ukraine
to study the solar cosmic rays and dynamics of the
Earth’s radiation belts onboard the Russian spacecraft “Coronas-Photon”. The instrument consists ofa detector unit installed on the external surface of thespacecraft, and a digital data processing unit located ina hermetic module. The detector unit (Fig. 1) contains
two identical silicon position-sensitive matrix detectors
D1 and D2, and two CsI(Tl) scintillator crystal detectors viewed using large-area photodiodes (D3) and aphotomultiplier tube (D4). Each element of the siliconmatrix is a separate autonomous semiconductor detector, and has its own analogue signal shaping ampliﬁer.
Some operational characteristics of the instrument arepresented in Table 1.
Calibration measurements of each type of detector
were carried out by the RIKEN Ring Cyclotron by using α-particle beams of energy E = 100 MeV/nucleonand H2 ion beams of energy 70 MeV/nucleon. Aluminum absorbers of thickness 21, 25, 30, 35 and 36 mm
were used to obtain various energies of the incident
α-particles. Measurements without an absorber werealso carried out. The pulse amplitudes from detectors
D2 and D3 corresponding to the incident α-particle
energies 62.5, 84, 164, 214, 254, and 400 MeV wereobtained in the experimental energy spectra. Simultaneously, computer simulations of energy losses by the

Table 1. Operational characteristics of the instrument.
Event Logic§ Energy Range (MeV) Measurements
D1D2D3D4 Electrons: 0.2–0.45, Intensities of parProtons: 3.5–7.3,
ticles in the full
Alphas: 13.7–29.5
field of view
D1D2D3D4 Electrons: 0.45–0.55, Energy and anguProtons: 7.3–9.9,
lar distribution of
Alphas: 29.5–40.1
particles
D1D2D3D4 Electrons:1.2–16,
Energy and anguProtons: 14.5–61,
lar distribution of
Alphas: 62–249
particles in 10 differential energy
channels
D1D2D3D4 Electrons: > 16.8,
Angular distribuProtons: > 64,
tions and integral
Alphas: > 262
intensities of particles§

D1D2 means logical coincidence, D1D2 means logicalanti-coincidence .

Cern GEANT4 Toolkit in the detectors by α-particles
in the energy range 10–410 MeV were carried out for asmall number of particles (N = 10) with variable steps
of input energy. Figure 2 shows results of the simulation as well as experimental data (in volts) for detector D3, which is used as an E-detector in the dE/dxE technique. The comparison of simulation resultswith experimental data allowed us to verify the energy
ranges of α-particles recorded by the detectors. Alphaparticles with energies up to 13.7 MeV are stopped by
the shielding aluminium foil placed immediately above
the ﬁrst silicon matrix D1, while α-particles with energies in the ranges 40.5–62 MeV, and 248.5–262 MeV
are stopped in the coating materials of the scintillation

Fig. 1. Common view of detector unit and positionsensitive silicon matrices of the satellite spectrometertelescope STEP-F.
∗1
∗2
∗3

168

Kharkiv National University, Ukraine
Japan Aerospace Exploration Agency, Tsukuba Space Center
FAM Science Co., Ltd.

Fig. 2. Simulation results of deposited energies (solid
curves) compared to the experimental data (dots) ofpulse amplitudes from α-particle signals.

detectors D3 and D4. Excluding these energy gaps,
particles with energies from 13.7 MeV to 262 MeV are
stopped in the active detector materials and make contributions to the pulse amplitudes of analogue signals.
In order to study the eﬀects of secondary particles
on detector signals, the energy spectra from most of
the D1 and D2 matrix elements were obtained by using a 140 MeV H2 ion beam. The axis of the beam wasdirected in parallel to the telescope axis and was displaced to peripheral elements 7, 8, 9, and 11 of the matrices as shown in Fig. 3 (the beam is indicated by thecircle). These elements registered 58, 36, 3 and 2.5%of particles, respectively, which is consistent with thepresent beam size of 5 mm. Figure 4 shows a typical
spectrum measured from element #7 of matrix 1.
Protons of energy E = 70 MeV compose the major part of a beam as is shown in Fig. 4. In counting the number of particles detected by each elementof the matrix, either protons (crosshatched region in
Fig. 4) or secondary particles with energies less than
70 MeV were taken into account. The number of particles recorded during the calibration process by element#7 of each matrix is taken as a relative unit.
The total quantities of particles recorded in most of
the elements in both matrices are presented in Fig. 5.
Both primary beam particles and secondaries producedin the aluminium foil above D1 and in detectors D1,
D2 and D3 (albedo particles), are taken into account.
To indicate the diﬀerencies in the number of particles

detected by various elements, a logarithmic scale isused on the vertical axis. Figure 5 shows that particles were mainly recorded by elements 7, 8, 9 and 11(crosshatched columns) and in a negligible number —(< 1%) — by closely neighboring elements.
Computer simulations were also performed for thesame conﬁguration of elements in terms of both siliconmatrices and direction of the beam axis. One hundred and ﬁfty thousand primary protons at the energyof 70 MeV were simulated. The number of recorded
particles in each element of the matrices was calculated by the technique used in the experiment, andwas normalised to the number of particles in element#7, as in the experiment. Figure 5 presents simulation
results, giving the number of primary protons and secondary particles recorded in the elements of two matrices (light columns). Figure 5 shows a fairly good
agreement between the experimental data and simulation. A conclusion may also be drawn that the eﬀects
of secondary particles in detector signals are almost
negligible when operatimg at high primary particle energies. In particular, the number of secondary albedo
particles produced in the scintillation detector D3 isnegligible. Therefore, the error in the counting rateof the D2 detector due to the production of secondary
species in the D3 scintillator at high energies of charged
primary particles will be small.
This work is supported by the Science and Technology Center in Ukraine (STCU Grant N 1578).

Fig. 3. Beam projection on the elements of the silicon matrix. Spatial scale is preserved.

Fig. 5. The number of particles in each element of bothmatrices after passage of H2 beam (experimental data
and results of simulation).

References
Fig. 4. Spectrum of ions H2 and decay products from element #7 of matrix 1.

1) O. V. Dudnik, T. Goka et al.: Adv. Space Res., 32,
2367 (2003).

169

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Design of an RF beam splitter for a time-sharing
beam delivery to BigRIPS and RIPS
H. Ueno, A. Yoshimi, and K. Asahi
In the RIBF conﬁguration, medium- and heavymass beams can be accelerated up to the energy of
E = 115 AMeV with IRC. When a beam-transportline from IRC to RIPS in the existing facility is constructed, intense beams with a wide range of atomic
number can be also provided to RIPS as well as BigRIPS. The energy region around 100 AMeV is preferred in experiments utilizing the fragment-induced
spin polarization because of its mechanism, as wellas the material science with radioactive-isotope beams(RIBs).1)
We are proposing the operation in the time-sharing
scheme between BigRIPS and RIPS by using a present
RF beam splitter system, whose schematic layout isshown in Fig. 1. The extracted beam from IRC isintroduced into the RF beam splitter system. The basic structure of the system is similar to that of theexisting RF beam deﬂector system.2) A high voltage
is applied to vertically arranged parallel electrodes ata frequency of 9–22 MHz, which is adjusted to onehalf of the cyclotron frequency. The system deﬂects
each extracted particle bunch up and down at anglesof ±θdef alternately. Here, a static magnetic ﬁeld isapplied to the beam on the horizontal plane perpendicular to the incoming beam, which changes the beam
angles of −θdef and +θdef into −2θdef and 0, respectively. The required magnetic ﬁeld strength is ∼0.04 T.
Then the beam is introduced into a Lambertson-typeseptum magnet,3) which is located downstream of the
RF beam splitter.
The Lambertson magnet is a special dipole that contains two areas for a beam. One area has a magnetic
ﬁeld and bends the beam. The other area is shieldedfrom the ﬁeld and the beam simply passes through it.
The θ = 0◦ beam goes to SRC through a tunnel built
in the pole of the magnet. The single operation of
BigRIPS can be easily carried out only by turning oﬀ
the RF beam splitter system: the beam simply goes to

SRC through the tunnel of the Lambertson magnet.
In this beam-sharing scheme, the beam is delivered to
SRC at a period of 91–222 ns depending on the cyclotron frequency. This beam evolution period is very
short so that the beam loading eﬀects are considerednegligible. On the other hand, the θ = −2θdef beam
goes through the pole gap of the Lambertson magnet.
The pole gap is slanted oﬀ the horizontal plane. The
Lambertson magnet deﬂects the beam by 20 degrees.
Then the beam is introduced into the beam-transportline connected to RIPS. The maximum magnetic rigidity of the beam-transport line from IRC to RIPS is
designed to be Bρ = 4.2 Tm. This value is suﬃciently
large to accept the beam extracted from IRC except
for the very heavy ions near uranium.
The existing RF deﬂector is a type of quarterwavelength coaxial resonator with an upright ﬁxedlength cavity.2) The frequency is adjusted with the capacity tuner attached on the side. We have designed
a similar type of resonator, but the cathode cavity is
tuned with a sliding RF short plate. In this conﬁguration, the width of the system becomes narrower, thus
the system is only 1 m wide, whereas the RF deﬂector
is 2.4 m wide. Since the lateral space for the installation of the RF beam splitter is limited at the exit of
IRC, the present conﬁguration is suitable.
In our design, the maximum high voltage of 150 kV isapplied to the electrode with a length of 1000 mm anda gap of 30 mm. Based on a model calculation, where
the transmission-line model of the distributed constantcircuit is taken into account in the one-dimensional
approximation, the power loss of the cavity is expected
to be less than 50 kW.4) This power loss does not cause
serious problems to the cooling of the cavity.
At the entrance of the Lambertson magnet, whichis placed 2 m downstream the RF beam splitter, the++beams of 86 Kr35 and 136 Xe52 with an energy of
115 AMeV are deﬂected by 42 mm and 39 mm fromthe central trajectory, respectively. These values are
expected to be suﬃciently large to construct the Lambertson magnet.
References

Fig. 1. A schematic layout of the RF beam splitter system.

170

1) Y. Kobayashi et al.: Eur. Phys. J. A 13, 243 (2002); W.
Sato et al.: J. Radioanal. Nucl. Chem. 255, 183 (2003).
2) K. Yamada et al.: RIKEN Accel. Prog. Rep. 34, 201(2001); K. Yamada et al.: RIKEN Accel. Prog. Rep.
35, 147 (2002); K. Yamada et al.: RIKEN Accel. Prog.
Rep. 36, 190 (2003).
3) L. W. Olesiuk et al.: IEEE Trans. Nucl. Sci. NS-20,
428 (1973).
4) H. Miyazaki: Private communication (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Test experiment on the low-energy RI extraction system
H. Miyoshi,∗1 K. Asahi,∗1 K. Shimada,∗1 A. Yoshimi, D. Kameda,∗1 H. Ueno,
H. Watanabe, T. Haseyama, J. Murata,∗2 S. Emori,∗1 G. Kato,∗1
G. Kijima,∗1 M. Tsukui,∗1 and Y. Kobayashi
Spin polarized low-energy radioactive isotope (RI)
beams are useful not only in nuclear physics but also inmaterials and surface physics. We are developing a device that produces a spin polarized low-energy RI beam
based on the atomic beam resonance technique. A prototype, including a fragment stopping and collecting
gas chamber, a jet separator, an atomic-beam forming
nozzle and a spin-selecting sextupole magnet is almost
completed. At present, we are detailing the design ofthe fragment stopping and collecting gas chamber.1)
In the present paper, we report on test experimentson the chamber using a RI beam delivered by the fragment separator RIPS.
The schematic setup used for the test experiments
is illustrated in Fig. 1. The pressure of helium gas
in the RI stopping gas chamber was approximately
600 Torr. We chose a beam of 31 Al ions produced by
the fragmentation of an 40 Ar projectile at an energyof 95 MeV/nucleon on a 3.5-mm-thick Beryllium target. The intensity of the 40 Ar primary beam was approximately 50 pnA. The intensity of the 31 Al beam
was approximately 104 particles/sec at the entrance ofchamber. Using the rotating degrader, we adjusted theenergy of 31 Al ions at the entrance of the chamber suchthat which were safely stopped in the He gas volume.
Figure 2 illustrates the system of detectors employed
as a β-ray tracking system. The system consisted of
two layers: the ﬁrst layer had 12 plastic scintillators(45×0.5×210 mm) and the second layer had 30 plastic
scintillators (25 × 25 × 200 mm).
The stopping chamber involved 50 electrodes withwhich a static electric ﬁeld was applied in order to extract the stopped ions. The detailed arrangement is
described elsewhere.1) The experimental result is summarized in Fig. 3.

Fig. 1. Schematic view of experimental setup.
∗1∗2Department of Physics, Tokyo Institute of Technology
Department of Physics, Rikkyo University

Fig. 2. The β-ray tracking system. The beam transportand energy regions of the incident 31 Al ions were so
arranged that the region in the gas where the 31 Al
ions were stopped is distributed indicated by the shadowed cylinder. The cylindrical region was surroundedby an array of 50 ring electrodes with an inner diameter of 20 mm. After extraction using the electrodes,
ions reached the catcher in the second chamber. β-rays
emitted from the 31 Al ions were detected by the ﬁrst
and second plastic scintillator layers. From the two positions extracted from the two scintillator layers, thesource point was deduced.

Fig. 3. The left part shows a schematic view of the downstream chamber which is called a jet separator. The
right two panels show the deduced position distributionof the source points along the beam axis; the upper one
being the distributions with the electrodes voltages on
and oﬀ, and the lower one being their diﬀerence. A peak
point is observed at around the −70 mm position. Thisis consistent with the position of the catcher which isshown in the left panel.

171

Considering the chamber walls and the β-ray energy,
the β-ray emitted from the ﬁrst chamber could not becounted by the tracking system. Moreover, because of
the resolution of the tracking system, we could distinguish the position of catcher. From the result of Fig. 3and calculations, the extraction eﬃciency for the 31 Al
incident at the stopping gas chamber was determined
to be 3.8 × 10−4 . In deducing this number, the efﬁciency of the β-ray detection with the plastic scintillator telescope array and its solid angle were taken
into account. The obtained value for the extraction
eﬃciency is not large at the present test experiment.
The loss by extraction eﬃciency might come from possibly incomplete stopping in the stopping gas chamber,
irregular focusing caused by the electrodes, neutralization of ions due to contaminations in the chamber ordiﬀusion of ions in the second transportation chamber.
The second test experiment was performed in
September. The aim of the test experiment was to
exclude the above possible eﬃciency losses, for example, in this experiment, we employed 34 P ions and the172pressure of He gas was approximately 1200 Torr. We
conﬁrmed that contamination was less than 1 ppb bymeasuring gas impurity using a quadrupole mass spectrometer (PFEIFFER QMG 422). When the numberof counts of He is 107 counts at QMG 422 at approximately 10−6 Torr, the number of counts of sum of contaminations is less than 102 counts. During the ﬁllingof He gas in the chamber, other contaminations were
not increased. To improve the collection eﬃciency, wechanged the partition of the applied voltages at theelectrodes. As for the detectors, we installed a trigger
counter (210 × 800 × 5 mm) to detect β-ray from 34 P
with a high S/N ratio and a veto counter to exclude
the background. The details of the electrodes and theircharacteristics are described elsewhere.1) The analysisof the obtained data is now in progress.
References
1) K. Shimada et al.: RIKEN Accel. Prog. Rep. 37, 175(2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

On-line collection of 8 Li ions from the projectile fragment separator
using an rf ion guide system (III)A. Takamine,∗1 M. Wada, Y. Ishida, T. Nakamura,∗2 T. Kambara, H. Ohyama, Y. Kanai, T. M. Kojima,
Y. Nakai, N. Oshima,∗1 A. Yoshida, T. Kubo, Y. Matsuo, Y. Fukuyama, K. Okada,∗3 T. Sonoda,∗4 S. Ohtani,∗5K. Noda,∗6 H. Kawakami,∗2 I. Katayama,∗2 Y. Yamazaki, H. Wollnik,∗7 V. Varentsov,∗8 and P. Hosteins
The projectile fragment separator provides a wide
variety of short-lived RI ions which are partially not
restricted to their chemical properties and lifetimes.
The beam energy and quality is, however, are not adequate for low-energy beam experiments, in particular, for trapping experiments. We have been working
on technical developments for obtaining a low-energy
beam from an energetic RI beam leaving a projectile
fragment separator using the rf ion guide system.
The rf ion guide system consists of an energy degrader, a large He buﬀer gas cell and an rf ring electrode assembly. The energetic RI beams (∼100 MeV/
nucleon) coming from the fragment separator passthrough two wedged degraders of variable angle andthickness.
The medium energy beam (∼2 MeV/
nucleon) thus obtained is then injected into a large
He gas cell for stopping and thermalization. The highionization potential of He allows for keeping the RI
ions in the singly charged state. The stopped ions canbe extracted by the dc ﬁeld applied between the cellas the anode and the exit as the cathode. In the rf ion
guide, the cathode electrode consists of many ring electrodes to which rf voltages are applied in addition to
dc potentials, with the idea that the average force dueto the rf gradient ﬁeld drives the ions away from theelectrodes. The extracted ions can be transported by
SPIG1) through a number of diﬀerential pumping sections toward experimental instruments in an ultrahighvacuum.
We have tested several diﬀerent geometries of therf ion guide setup on-line with 100-MeV/nucleon 8 Li
beams provided by the RIKEN projectile fragment separator RIPS.2,3) Thus far, the maximum overall eﬃciency of 1% and the maximum yield of approximately
2,000 8 Li ions per second were obtained.3) We report
here the recent test experiment with a new gas cell geometry (Fig. 1). In the new gas cell, a linear dc ﬁeld
can be applied in the entire region of the cell in order to increase the eﬀective volume (Fig. 2) and an
extraction electrode assembly with a new rf carpet is
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Graduate School of Arts and Sciences, University of Tokyo
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
Department of Physics, Sophia University
Cyclotron and Radioisotope Center, Tohoku University
Institute for Laser Science, University of Electro-Communications
National Institute for Radiological Science
University of Giessen, Germany
Radium Institute, Russia

Fig. 1. New gas cell (40 cmφ × 2 m). The linear dc ﬁeld
is generated. Lines represent equipotential lines andthe big arrow indicates the injecting 8 Li beam whichis intentionally inclined to the cell in order to avoid
injecting fast 8 Li ions into SSD behind the exit nozzle.

Fig. 2. Cu cylinder installed in the gas cell. A linear dc
ﬁeld is produced by electrodes on printed circuit boards
mounted in the Cu cylinder. The Cu cylinder is connected to a cryogenic head to cool the cylinder.

placed at the bottom of the cell. Since the detector
for 8 Li is still mounted just behind the extraction nozzle, the cell is inclined so as to avoid injecting fast 8 Li
ions directly into the detector. The new rf carpet consists of an outer part and a central part. We apply rf
voltages with dc oﬀsets to the central part while a simple dc potential gradient is applied to the outer part.
The central part has 160 ring electrodes, the intervalof which is 0.28 mm with an exit nozzle of 0.7 mm indiameter.
Figure 3 shows the overall eﬃciency and yield as afunction of the incoming 8 Li beam intensity. The maximum overall eﬃciency of 3.6% was achieved when the
beam intensity was low at the highest dc ﬁeld. However, a decrease was observed as the beam intensity
was increased, and three lines converged to the line
whose yield was nearly proportional to the square root

173

Fig. 3. Overall eﬃciency and yield of extracted 8 Li ionsas a function of intensity of incoming 8 Li from RIPS.
The rf voltage on the rf carpet was 150 Vp.p. . “Vcp ”
is deﬁned as the potential diﬀerence between the twoedges of the cylinder, the inside of which a linear dc ﬁeld
is generated. (Even if Vcp = 0 V, penetration ﬁelds fromthe rf carpet exist inside the cylinder.) A maximum
yield of 26,000 cps was obtained when the incoming
beam intensity was highest.

of the incoming 8 Li intensity. We also obtained a time
proﬁle3) of extracted 8 Li by deconvoluting the time
spectrum of the delayed α-decay of 8 Li (Fig. 4).
Since the mobility of 8 Li at 100 Torr He gas is
152 cm2 V−1 s−1 , it should take only 600 ms for a 8 Li
ion to travel a 2 m distance when Vcp = 400 V. The
time spectrum in Fig. 4 shows the presence of slower
components, which suggests that the dc ﬁeld is weakened by the space charge eﬀect due to the presence of
charged particles (mainly He+ ) produced by injectedbeams.
The yield dependence on the intensity can be explained in two diﬀerent ways. One is that the phenomenon is due to the recombination process between
the 8 Li ions and electrons which are produced by injected ion beams. It is because such a process can be
described using the rate equationdn= −αn2 + Q
dt(1)with n is the ion density, α the eﬀective recombination coeﬃcient and Q the 
ionizing rate, and then theequilibrium density neq = Q
α . The other is that thephenomena is due to the space charge eﬀect. The factthat the yield curves in Fig. 3 converge when the beam

174

Fig. 4. Time proﬁle of the 8 Li ions when Vcp = 400 V at
two beam intensities. Each proﬁle is normalized to thesum is equal to the eﬃciency. This shows that ions canbe extracted far from the exit.

intensity is high supports this explanation. As can beseen from the time spectrum at the highest beam intensity, the fraction of slow components is small. Thus,
the extractive volume seems to be restricted to the region just in front of the rf carpet where the dc ﬁeld applied to the cylinder is less eﬀective. When the beam
intensity is low, on the other hand, the space charge
eﬀect should not be signiﬁcant, then the extractive volume can be expanded to the entire cylinder. However,extraction time which depends on the Vcp causes another loss of 8 Li ions due to their lifetime. The yielddependence on Vcp at the lowest beam intensity supports this explanation. For the moment, we could notjudge which one is the dominant eﬀect. Further investigation on this problem is required.
The absolute intensity of the low-energy 8 Li wasmore than 26,000 atoms per second, which is suﬃcient for various experiments. Since a similar intensity
is expected for 11 Be ions, we will begin the precision
spectroscopy of the hyperﬁne structure of the trapped11
Be isotope aiming at studying the Bohr-Weisskopf
eﬀect.4)
References
1) H. Xu et al.: Nucl. Instrum. Methods Phys. Res. A 333,
274 (1993).
2) M. Wada et al.: Nucl. Instrum. Methods Phys. Res. B
204, 570 (2003).
3) M. Wada et al.: RIKEN Accel. Prog. Rep. 36, 194(2003).
4) T. Nakamura et al.: Opt. Commun. 205, 329 (2002).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Design of RI extraction system with a static electric field
K. Shimada,∗1 K. Asahi, H. Miyoshi,∗1 A. Yoshimi, H. Ueno, J. Murata,∗2 Y. Kobayashi, K. Sakai,∗1
H. Watanabe, T. Haseyama, D. Kameda,∗1 S. Emori,∗1 G. Kato,∗1 G. Kijima,∗1 and M. Tsukui∗1
A method for producing slow neutral radioactive
isotope (RI) beams and for measuring their electromagnetic moments is under development, which is expected to be applied generally to the whole region of
the nuclear chart. The method is essentially based on
the atomic beam resonance technique,1) and has a few
advantages over the fragmentation-based polarization
method which has so far been employed in nuclear moment measurements in light unstable nuclei. A key issue
for the successful application of the present method to
RI produced in the projectile-fragmentation (PF) reaction is the formation of a slow neutral RI beam2) fromthe PF reaction products which have inevitably high kinetic energies.
To produce slow RI beam, the RI ions produced by
the PF reaction are introduced into a high-pressure helium volume where most of them are eventually stopped(Fig. 1). In this volume, we apply a parallel and rather
strong electric field, so that the stopped RI ions are
swiftly separated from the plasma region around thetrack of the RI ions and are drifted downstream. Closeto the end of this volume, the field lines are compressed
into a small-diameter bundle at the outlet orifice by increasing the field strength. The RI ions drift following
the field lines and are thus compressed into the orifice.
In the region close to the orifice, there exists helium gas
flowing going out of the orifice, and because of a converging corn placed upstream of the orifice, the flow velocity rapidly increases and helps the RI ions to be transported through the orifice. As soon as the RI ions andthe carrier helium gas enter the downstream chamber(jet-separator (JS) chamber), the RI ions are forced toproceed further downstream by a strong parallel electricfield, while the helium gas is evacuated using a highpower vacuum pumping system. In the section placed
after this, the neutralization is achieved by the passageof the ion beam through the charge exchange gas,3) but
the details are under investigation.
In the present work, we designed and fabricated an RI
extraction chamber. The first chamber for RI-stopping
and RI-drifting volume involves electrodes consisting of
36 stainless-steel discs and intervening ceramic spacers. The upstream 33 electrodes are 1-mm-thick discs

of 58 mm in diameter with respective inner openings of
20 mm in diameter. The remaining three (34th, 35thand 36th) electrodes have inner openings of 15 mm,
10 mm and 5 mm in diameter, respectively. The ceramic
spacers located close to the nozzle have a tapered holeand form the converging corn. This corn suppresses thedischarge between electrodes, so that we could apply
2.1 kV to the last electrode. The orifice of the nozzle
is as low as 0.2 mm in diameter. This diameter is chosen
to increase the pressure of the first chamber, so that approximately 70% of the energetically spread RI ions sentfrom RIPS stop there. The second chamber is the JS
chamber, which consists of the same electrodes as thosein the first chamber. The total voltage applied to theseelectrodes is −700 V. The pressure stays at 40 Pa whichis 2.5 × 10−4 times as low as that in the first chamber.
A static electric field calculated with POISSON
codea) and the tracks of the drift of the incident ions
simulated in a computer are shown in Fig. 2. In thissimulation, the total voltages applied to electrodes in
the first chamber and in the second chamber are 2.4 kVand −700 V, respectively. In addition, the current of
the incident beam of approximately 10−14 A is so smallthat a charge of ions attached to the ceramic spacer isignored. The electric fields in the first chamber startwith as low as 8 V/cm, and in the final electrode it
rapidly increases to 2.3 kV/cm. As a result, the driftingions converge into the nozzle. For example, ions which
stopped at a radial distance of 10 mm from the axis of
the cylindrical stopping gas volume converge at a radial
distance of 0.6 mm just before the orifice. Since the velocity of the outgoing He flow is much larger than the ion
drift velocity due to the electric field the ions converged
into such radii are expected to be transported throughthe nozzle.

Fig. 2. The electric field and the track of the drift of theincident ions near the nozzle.

References
Fig. 1. Schematic picture of the gas stopping chamber.
∗1∗2

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

1) H. Miyoshi et al.: RIKEN Accel. Prog. Rep. 34, 181 (2001).
2) H. Miyoshi et al.: RIKEN Accel. Prog. Rep. 35, 143 (2002).
3) T. M. DeTurck et al.: Nucl. Instrum. Methods Phys. Res. B
172, 293 (2000).

a)

The Los Alamos Accelerator Code Group

175

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Development of slow muon beam line at the
RIKEN-RAL muon facility
Y. Matsuda, P. Bakule, K. Nagamine, Y. Miyake, K. Shimomura, S. Makimura, P. Strasser,
T. Matsuzaki, K. Ishida, and M. Iwasaki
We have been developing a slow muon beam line
at experimental port 3 in the RIKEN-RAL muon facility. The objective of this project is to constructa beam line that provides low-energy positive muon
beam (1–10 keV) with a superior resolution of beamenergy and time structure. Such beam can extend thescope of the µSR technique to thin films, multi-layered
structures, and extremely small samples, which are allimportant both scientifically and commercially. For
example, Giant Magnetic Resistance was first reported
in multilayers consisting of ferromagnetic layers anda thin nonmagnetic metallic layer, and its discovery has
led to many industrial applications. In these systems,
the magnetisations of the layers are coupled throughelectron spin density of the spacer layer. Various measurements have been carried out to understand thisinterlayer exchange coupling, but a probe for studying
the induced spin polarisation in the nonmagnetic intermediate layer is still lacking. Using slow muons, wewould be able to carry out depth-resolved µSR measurement in order to detect magnetic field distribution
in the intermediate layer.
These potentials of slow muons are widely recognised in major muon facilities, and several methodsof generating slow muons have been proposed.1,2) We
adopted the resonance ionization method developed at
Meson Science Laboratory of High Energy Accelerator Research Organization.2) This method is based on
the observation that a few percent of muons injected
into a hot tungsten film are emitted from its surface asthermalised muonium atoms with kinematic energies ofapproximately 0.2 eV. Then we irradiated two ionizing
lasers; 122 nm Lyman-α wavelength for exciting muonium atoms from 1S state to 2P state and 355 nm wavelength for stripping electrons from 2P state to generate
free muons, which were extracted and transported tothe sample position.
This scheme is particularly suitable for pulsed muon
beam facilities, where a bunch of muons is deliveredat a repetition rate of 20–50 Hz and a timing width of
100–150 nsec. Intense short-pulsed lasers can be synchronised to muon beams to generate pulsed slow muonbunches whose timing width is much smaller than thatof the initial muon beam, thus providing an excellent
energy resolution of the beam and an excellent time
resolution on the µSR spectrum.
We reported our first observation of slow muon beamat the RIKEN-RAL muon facility in our previous reports.3,4) Since then, we have improved our laser system by introducing a phase-matching scheme for the176

generation of ionizing VUV laser and optimised transport optics to minimise loss in our beam line.4) At thelast beam time in April 2003, we observed slow muon
beam with an intensity of 5/sec, which is more than
100 times larger than our previous results. The advantage of the laser resonant ionization method is demonstrated in Fig. 1; the timing width of the beam is lessthan 10 nsec, whereas that of our initial muon beam isabout 150 nsec. The obtained width of 10 nsec is muchbetter than that obtained in another experiment5) at
the ISIS EU muon beam line using the cyrosolid moderator method,1) in which the timing width of the initial beam is conserved in the slow muon beam. Slowmuon yield dependence on laser power was measured,and no saturation was observed for both 122 nm and355 nm lasers, leading us to expect a further increasein the yield by further improvement of laser power.
A work on upgrading the 355 nm laser is currently being undertaken.
In coming beam time, our plan is to measure beam
size at the sample position and optimize beam transport optics using this information. A position sensitive
MCP (Roentdek 40DLD MCP) has been installed andtested at the sample position for such purpose. A design work for the µSR spectrometer is also currently
being carried out, and we plan to install it in the springof 2004.

Fig. 1. Typical time-of-flight spectrum of slow muon beamobtained at the RIKEN-RAL muon facility.

References
1) E. Morenzoni et al.: Phys. Rev. Lett. 72, 2794 (1994).
2) K. Nagamine et al.: Phys. Rev. Lett. 74, 4811 (1995).
3) Y. Matsuda et al.: RIKEN Accel. Prog. Rep. 35, 138(2002); Y. Matsuda et al.: J. Phys. G 29, 2039 (2003).
4) P. Bakule et al.: Spectrochim. Acta, Part B 58, 1019
(2003).
5) K. Trager et al.: Physica B 289/290, 662 (2000); K.
Trager: Ph.D. Thesis, Universitat Heidelberg (1999).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Preparation of self-supporting boron films
S. Ozawa and M. Hamagaki
In nuclear physics experiments, self-supporting
boron ﬁlms are required as targets for projectile fragmentation. We developed a new method of preparing self-supporting boron ﬁlms by sputtering with anelectron-beam-excited plasma (EBEP).1)
A schematic of the experimental setup is shown in
Fig. 1. The principle of preparing boron ﬁlms is described in Ref. 2. The boron target is heated suﬃciently to become a conductor by several minutes ofelectron beam bombardment. At this point, the target temperature is 1100◦ C, which is maintained until the end of deposition. The boron target temperature is measured using an optical pyrometer. The
substrates are placed on a copper table whose temperature is controlled from 20 to 250◦ C. The temperatureof the table is measured using a thermocouple (notshown in Fig. 1). The sputtering target is a boron
tablet (φ 40 mm × 5 mm) with a purity of 99%. The
tablet is covered with carbon in order to supply bias
voltage (see Fig. 2). The material applied with bias
voltage is sputtered by Ar+ ions which are accelerated
by the bias voltage when the material comes into contact with plasma. Hence all of the materials, except
the boron tablet, must be covered by an insulator to
prepare high-purity boron ﬁlms. As shown in Fig. 2,
the carbon support and the copper feedthrough arecovered with an insulator to prevent them from being
sputtered by Ar+ ions with the bias voltage. The insulator cover for the target, which was made of hexagonalboron nitride, has an aperture of 28 mm because thediameter of the electron beam is approximately 30 mm.
The feedthrough is covered with ceramics tubes. Threekinds of substrate, namely, tantalum, Pyrex glass, andsilicon, are used in the experiment. To stop deposition, the electron beam is stopped and the bias voltage
is turned oﬀ. Then the ﬁlms are left to cool for more

Fig. 1. Schematic of the experimental setup.

Fig. 2. Schematic of the target. Only the boron surface was
sputtered by argon ions with energy equivalent to theapplied voltage. Previously, the carbon support was notcovered by an insulator and was consequently sputteredby argon ions.

than one hour in vacuum.
In the present experiment, a boron ﬁlm of
330 µg/cm2 was obtained on a silicon substrate after
one hour of deposition at Vt = −280 V and It = 0.76 A.
The deposition rate in the present experiment was
0.4 nm/s, and the temperature of the substrate was
20◦ C. However, ﬁlms exceeding 140 µg/cm2 started
ﬂaking on Pyrex glass substrates, as was observed in
our previous study,2) even though the sputtering rateand substrate temperature were the same as in thecase of silicon substrates. Boron ﬁlms on tantalum
substrates also start ﬂaking oﬀ at approximately thisthickness in the present experiment, whereas boron
ﬁlms on silicon substrates can be much thicker. The
surface of the glass substrate is smooth, but its thermal conductivity is low. The surface of the tantalum
substrate is rough. The roughness and the thermal
conductivity of the surface are thought to be more important than the kind of material. Silicon wafers havea smooth surface and high thermal conductivity.
To prepare self-supporting boron ﬁlms, LaCl3 andNiCl2 were tested for use in the present experiment.
LaCl3 is commonly used as a water-soluble compoundin the preparation of self-supporting carbon ﬁlms.
However, it was found that LaCl3 is not useful for separating boron ﬁlms from the substrate because La forms
a compound with boron. NiCl2 was used for preparing
self-supporting boron ﬁlms.
Boron ﬁlms on the tantalum substrate were preparedfor EPMA. The boron ﬁlm thickness was 70 µg/cm2 .
In the previous experiment,2) EPMA showed that theboron ﬁlm contained carbon, nitrogen, and oxygen. In
addition, we must investigate copper which is included177

in the feedthrough, the components of the stainlesssteel (SUS304) used for the target-holding ﬂange, andthe components of the Pyrex glass vacuum chamber.
We chose ﬁve kinds of spectrum crystals in order to detect all elements contained in the boron ﬁlm. The typical EPMA spectra of the elements which were detected
as impurities in our previous experiment2) are shownin Fig. 3. The upper spectrum was obtained by diﬀraction using an LDE-1H crystal that detects carbon, nitrogen and oxygen. The LDE-2 crystal detects boron,

carbon, nitrogen and oxygen, as does the NSTE crystal. An oxygen peak can be observed in the LDE-1H
spectrum because the LDE-1H crystal has a high sensitivity that enables it to detect oxygen absorbed on
the surface of the ﬁlms. The oxygen peak cannot be
observed in other spectra. Carbon and nitrogen are
not observed in any of the spectra. By using othertwo crystals to detect other elements (copper, tantalum, and ingredients of stainless steel and Pyrex glass),
only the tantalum peak can be observed. This is because the energy of the electron beam (15 keV) fromthe EPMA apparatus is suﬃciently high for the beam
to pass through the boron ﬁlm and reach the tantalum substrate. These results show that the amount of
impurities in the boron ﬁlms is less than the EPMA
detection limit.
A boron target without insulators was used in ourprevious experiment,2) and the amount of carbon inboron ﬁlms was more than 30%. After the carbon support of the boron tablet was covered with an insulator,
the amount of carbon in boron ﬁlms was reduced to below the EPMA detection limit. In our previous experiment,2) we introduced nitrogen gas into the vacuum
chamber, and exposed the ﬁlms to atmosphere immediately after stopping deposition. As a result, nitrogenand oxygen were considered to contain the boron ﬁlms.
In the present experiment, to reduce the amounts of nitrogen and oxygen, ﬁlms were left to cool for more than
one hour after turning oﬀ the bias voltage. The purityof almost 100% was achieved as a result of the following
improvements to the method of preparing boron ﬁlms:(1) the sputtering target was covered with boron nitride and (2) the ﬁlms were left to cool for more than
one hour in vacuum after the deposition.

Fig. 3. EPMA spectrum of boron ﬁlm. Three spectra wereobtained by diﬀraction of LDE-1H, LDE-2, and NSTE.
In the spectra, the positions of boron, carbon, oxygen,and nitrogen peaks are indicated by arrows.

1) M. Hamagaki et al.: Jpn. J. Appl. Phys. 33, 4369
(1994).
2) S. Ozawa and M. Hamagaki: RIKEN Accel. Prog. Rep.
36, 186 (2003).

178

References

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

R&D study of a self-confining radioactive ion target (SCRIT)
M. Wakasugi, T. Emoto, T. Koseki, K. Kurita, T. Ohnishi, T. Suda, H. Takeda, and Y. Yano
We propose a new colliding system of electrons andradioactive (unstable nuclei) ions, in which a highenergy electron beam collides with its self-conﬁning
RI ion target (SCRIT) formed in an electron storage
ring.1,2) Ions in the SCRIT are transversely conﬁned byrepetitious transverse focusing kicks given by electron
bunches and drift back and forth with very low velocity between two electrostatic mirrors placed a certain
distance apart. The concept of the electron-RI colliding system with the SCRIT is schematically shown in
Fig. 1. In this paper, the performance of the SCRIT asa target and the achievable luminosity are estimatedby numerical simulation, and the status of the R&D
study is described.
In the numerical simulation we deal with a 500-MeV
electron scattering oﬀ intriguing double-magic 132 Sn
nuclei as an example of its practical applications. The
parameters used in the present calculation are listed
in Table 1. We take three kinds of potentials into
account in calculating the motion of ions. The ﬁrst
is the time-dependent negative potential produced byan electron bunch that comes in the SCRIT periodically. The second is an additional positive electrostatic potential (mirror potential) for conﬁning ionslongitudinally. The third is a positive potential produced by the conﬁned ion cloud itself. We numericallysolve the equations of motion of each sample ion in the
superposition of these potentials. Atomic processes in

the SCRIT, for example, charge-state multiplication byelectron beam impact, nuclear decay, and residual-gas
ion capture are considered in the calculation. Detailsof the calculation are described in Refs. 1 and 2.
Time-evolution of the number of conﬁned ions (Ni )in the SCRIT is shown in Fig. 2 for several cases of
the number of initially injected ions (Ninj ). In the
short time range ( 1 ms) immediately after the injection of ions, the Ni quickly decreases with time andapproaches to approximately 3 × 108 for the case of
Ninj > 3 × 108 , as shown in Fig. 2 (a). The line
density of ions in the SCRIT at the saturation isabout 14% of the time-averaged electron line density of
1.67 × 108 cm−1 . In longer time range (see Fig. 2 (b)),
the Ni further decreases with increasing average charge
state. We found that the time evolution of the Ni depends on the number of injected ions Ninj , and 107 –108
ions can be conﬁned in the SCRIT for a few seconds.
The time-dependent luminosity in these cases is shownin Fig. 3, which is deﬁned in this calculation as 3σer  2π  ∞ρe (r, z)dz
L (t) = frf
0

0

−∞

Fig. 1. Electron-RI colliding system with the SCRIT.

Table 1. Parameters in the present simulations.
RI ion132
Elements
Sn
Initial kinetic energy and spread (keV)
10 ± 0.1
Pulse length at injection(cm)
4.0
Initial r.m.s. emittance(π mm · mrad) 10.0
Transverse r.m.s. beam size
(mm)
1.0
σix = σiy = σirLongitudinal length of ion cloud (mm)about 130
Electron Beam
Number of electrons in a
1010
bunch Ner.m.s. beam size σex = σey = σer (mm)
1.0
(mm)
15.0
r.m.s. bunch length σez
Energy(MeV)
500.0
RF frequency
(MHz)
500.0
Vacuum at the SCRIT
(Pa)
10−10
Mirror Potential
Structure of electrodes
Register divided ring electrodes
Maximum voltage at electrode
(kV)
20.0

Fig. 2. Time-evolution of the number of confined ions inshort time range (a) and longer time range (b).

Fig. 3. Time-dependent luminosity.

179

×

 ∞
−∞


ρi (r, z, t)dz

rdrdθ,(1)

where ρe (r, z) is the density distribution of the electron
bunch, which is a Gaussian distribution, and ρi (r, z, t)
is that of the conﬁned ion cloud obtained in each time
step of the calculation. The luminosity can be kept
at more than 1027 s−1 · cm−2 for a few seconds. During the measurement of the electron-RI scattering, we
repeat the ion-injection and the release with the appropriate period (τcycle ), and the time-averaged luminosity is calculated in the unit cycle as τcycle1
L=
L (t) dt.
(2)
τcycle 0
The time-averaged luminosity depends on the Ninj andthe τcycle . The Ninj is a function of the production rate
(Nprod ), the total injection eﬃciency (εtotal ), and theτcycle asτcycleNinj = Nprod εtotal τlife 1 − exp −
, (3)
τlife
where τlife is the nuclear lifetime (τlife = 40 s for
Sn). Assuming εtotal = 0.1%, the time-averaged
luminosities are shown in Fig. 4 as a function of the
Nprod for several cases of the τcycle . When a very large
amount of ions are injected, the ions are heated up immediately after injection by a space charge eﬀect andescape out more rapidly as shown in Fig. 2 (b) and
Fig. 3. That is the reason why the luminosity curvefor each case has a peak in Fig. 4. The dashed line isa trace of the maximum values for these cases of theτcycle . This line indicates achievable luminosity under
the present conditions. If we have the production rateof more than 1010 s−1 and choose an optimum period of
the injection cycle, the SCRIT gives us the luminosityof more than 1027 s−1 · cm−2 , which is a suﬃcient value
for the measurement of the nuclear charge distributionof 132 Sn.3)
The SCRIT device has been constructed to demonstrate our idea. Photographs of the SCRIT system
are shown in Fig. 5. It consists of a pulse ion source,
an ion transport line, an ion injector electrode system, a beam position monitor (BPM) for the electron
beam, and the SCRIT electrode system. The pulse
132

Fig. 5. Photographs of the SCRIT system and the SCRIT
electrodes.

ion beam (Sn1+ ) is produced by a laser ablation process using a pulse YAG laser and accelerated up to
10 keV. The ion transport line includes four steering
electrodes, two Einzel lenses, and a Faraday cup. The
injector electrode is a 90-degree electrostatic deﬂector
and merges the ion beam to the electron beam orbit,
which is measured by the BPM. The SCRIT electrodesystem is shown in the right-hand side of the ﬁgure; it isa register-divided ring-electrode system having 40 thinelectrodes and 2 terminal electrodes. The upper andlower parts of these electrodes have a mesh structurewith 93% opening rate so that recoiled ions and scattered electrons can pass through the electrodes without
any obstacles. Every electrode is connected to a highvoltage feed-through and we can create any form of
longitudinal potential in the SCRIT region by applying an appropriate voltage to each electrode. At bothterminal electrodes, the highest voltage is applied anda potential well for ion trapping is formed between theterminals. When a pulse ion beam is injected, the potential wall at the injector side is reduced by a fastswitching system.
The vacuum condition of the SCRIT devices is important because the electron storage ring in which the
SCRIT will be installed works under the vacuum oflower than 10−7 Pa and the lifetime of the stored electron beam strongly depends on the vacuum condition.
After one-day baking at the temperature of 250◦ C, thevacuum of the SCRIT chamber was determined to be
3 × 10−8 Pa by evacuating with two ion pumps having
an evacuation velocity of 500 l/s per each.
The SCRIT devices will be installed in the electron
storage ring (KSR) at Kyoto University and the test
experiment for ion trapping will begin in 2004.
References

Fig. 4. Time-averaged luminosity for several τcycle as afunction of production rate.

1801) M. Wakasugi et al.: to be published in Proc. Int. Workshop on Beam Cooling and Related Topics, Yamanashi,
2004-5.
2) M. Wakasugi et al.: Proc. 14th Symp. on Accelerator Science and Technology, Tsukuba, 2003-11 (KEK,
Tsukuba, Japan, 2003), p. 17.
3) T. Suda et al.: RIKEN Accel. Prog. Rep. 37, 81 (2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Loop-gap resonator for polarized proton target
T. Wakui,∗1 M. Hatano,∗2 H. Sakai,∗1,∗2 A. Tamii,∗3 and T. Uesaka∗1
A polarized solid proton target using a crystal ofnaphthalene doped with pentacene has been developed.1) The target is unique among polarized solid targets in that protons in the crystal can be polarized ina magnetic ﬁeld of 0.3 T or lower and at a temperature of 77 K or above. This feature allows the target
to be used in RI beam experiments, which are usually
carried out under the inverse kinematic condition. The
ﬁrst experiment with the 6 He beam of 71 MeV/nucleon
was carried out in July 2003.2) The target system forthe experiment is described in Ref. 3.
For polarizing protons, a large population diﬀerence
which appears on the lowest triplet state in pentacene
by optical excitation is transferred to protons by atechnique based on cross-relaxation between electron
and proton spins.4) This method, which was originallycalled the integrated solid eﬀect,4) utilizes electron spinresonance (ESR) with adiabatic fast passage (AFP).
That is, an external magnetic ﬁeld is adiabaticallyswept through an ESR line during microwave irradiation. In the AFP, the eﬀective Larmor frequency, ωeﬀ ,in a coordinate system rotating with the frequency ofthe microwave, ω, is given as
2 + (ω − ω),ωeﬀ = ωR(1)swhere ωR is the Rabi frequency, ωR = γs H1 , and ωsis the Larmor frequency of electrons. At the point
where ωs = ω, the eﬀective frequency is dependent
only on the amplitude of the oscillating ﬁeld. If weadjust the amplitude of the oscillating ﬁeld so that theeﬀective frequency of electrons is equal to that of protons, we fulﬁll the Hartmann-Hahn condition for crossrelaxation. Here, the exchange of spin polarization
takes place owing to the dipolar interaction between
electron and proton spins. As a result, polarization istransferred from the electron to the proton.
For polarization transfer, a cylindrical microwave
cavity with a resonance frequency of 9.1 GHz has beenused in the prototype proton polarizing system.1) The
cylindrical cavity is enclosed by thick copper walls
which prevent low-energy recoiled protons from reaching the detectors. Thus, we introduced a copper-ﬁlm
loop-gap resonator (LGR)5) instead of the cylindricalcavity so that recoiled protons can reach the detectors. The LGR is made of a 25-µm-thick Teﬂon sheet
which is coated on both sides with copper metal withthe thickness of 4.4 µm each. The copper is etchedto create capacitive gaps due to overlapping regionsof copper, as shown in Fig. 1 (a). The etched sheet
∗1
∗2
∗3

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

Fig. 1. (a) Schematic view of the etched Teﬂon sheet. The
overlap of copper regions on the two surfaces of Teﬂon
sheet creates capacitive gaps. (b) Schematic view of the
LGR. The LGR is inductively coupled to a microwave
circuit using a coupling coil.

is formed into a cylindrical loop, which acts as an inductive element. The LGR is inductively coupled toa microwave circuit using a coupling coil, as shown in
Fig. 1 (b). Inductance, L, and capacitance, C, can becalculated using the semi-empirical equations5,6)



2r
2r
r2
L=
0.2 − 0.45
+ 1 µ0 π(2)zzz(w + t)(z + t),
(3)
C = κe ε0nt
where r is the radius, z is the length of the LGR, µ0 is
the magnetic permeability, κe is the dielectric constantof the Teﬂon sheet, ε0 is the permittivity, w is the gap
width, t is the gap thickness, and n is the number ofgaps.
To produce an oscillating magnetic ﬁeld with thesuﬃcient amplitude to fulﬁll the Hartmann-Hahn condition, the LGR should be designed so that its diameter and length are small compared with a quarterwavelength, λ/4, of the microwave. If the dimensions
are close to λ/4, the LGR will act as an antenna andemit radiation, which greatly decreases the quality factor of the LGR. Indeed, we could not ﬁnd the resonance for the LGR designed to have the resonant frequency of 9 GHz with the diameter of 8 mm. In addition, the diameter of the LGR had to be enlarged
to 16 mm for the experiment with 6 He beam. Thus,
we lowered the microwave frequency to 3 GHz, making
allowance for further enlargement of the diameter in a
future experiment.
Figure 2 shows a plan for the LGR of the designed
frequency of 2.3 GHz. The designed frequency was chosen by taking into account the large deviation reported
for frequencies lower than 3 GHz, which is up to 20%.5)
The diameter and the length were 16 mm and 20 mm,

181

Fig. 2. Plan for upper and lower sides of the LGR designed using Eqs. (2) and (3). The designed frequency
is 2.3 GHz. The solid black regions represent copperremaining on Teﬂon sheet after etching.

100 K, the resonant frequency changed to 2.73 GHz.
To prove the eﬀectiveness of the LGR in polarization transfer, we measured the polarization rate at the
beginning of buildup as a function of the incident microwave power. Figure 4 shows the result of the measurement. The polarization rate increases rapidly andreaches a maximum at 1.0 Watt. This shows that the
LGR produces an oscillating ﬁeld with the suﬃcient
amplitude to transfer the polarization from the electron to the proton.

respectively. The number of gaps was 15. When the
LGR was mounted in the target system, unwanted
resonances from other conductive components aroundthe LGR appeared. To prevent these unwanted resonances, the LGR was covered with a cylindrical shield
made of aluminum with the thickness of 12 µm. Figure 3 shows the input reﬂection coeﬃcient measured
as a function of the frequency at the temperature of
100 K. The measured resonant frequency was 2.78 GHz
at room temperature. When the LGR was cooled toFig. 4. Dependence of the polarization rate on the incident
microwave power. The most eﬃcient transfer of polarization occurs at the power of 1.0 Watt.

References

Fig. 3. Input reﬂection coeﬃcient measured at the temperature of 100 K using a vector network analyzer. The
resonant frequency is 2.73 GHz.

182

1) T. Wakui et al.: RIKEN Accel. Prog. Rep. 34, 194(2001).
2) M. Hatano et al.: RIKEN Accel. Prog. Rep. 37, 44(2004).
3) M. Hatano et al.: RIKEN Accel. Prog. Rep. 36, 48(2003).
4) A. Henstra et al.: Phys. Lett. A 134, 134 (1988).
5) B. T. Ghim et al.: J. Magn. Reson. A 120, 72 (1996).
6) G. A. Rinard et al.: J. Magn. Reson. A 105, 137 (1993).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Feasibility study of monolithic SSD for measurement of low energy
nuclear reaction with GEANT4 simulation
M. Kurata-Nishimura, S. Nishimura, S. Kubono,∗ and I. Tanihata
The inhomogeneous big bang model1,2) enabled thesuccessful prediction of the synthesis of heavy elements compared with the standard primordial nucleosynthesis model which makes reasonably accurate
predictions of light-element abundances. In the inhomogeneous big bang model, 4 He(t, γ)7 Li(n, γ)8 Li(α, n)11B(n, γ)12 B(β, ν)12 C is considered to be a dominant
ﬂow path for explaining the synthesis of 12 C and heavy
elements in the very early universe. Recently, theabove sequence of reactions has also been identiﬁed
to play an important role in r-process nucleosynthesis occurring in supernova explosion.3) In both environments, it is claimed that the reaction cross section
must be determined in the direct reaction with center of mass energy less than 1 MeV. In that sequence,the 8 Li(α, n)11 B reaction is the source of large ambiguity caused by the short decay time of 8 Li. Previously,
several experiments were conducted to determine thisreaction cross section;4–6) however, the results of thoseexperiments were not in qualitative agreement witheach other. Moreover, the measurements of the lowenergy cross section below 1 MeV/n, which is the mostimportant energy region, have not been conducted yet
due to the diﬃculty in handling low-energy beams.
In an experiment performed at TRIUMF in 2001,7)
it is concluded that the 8 Li beam trigger is necessary
for rejecting a huge amount of background in a neutron spectrum. In order to overcome this problem, we
have been developing detectors and also low-energy
8
Li beam. In May, 2003, we performed an experiment to develop low-energy 8 Li beam using an in-ﬂight
low-energy radioisotope beam separator8,9) (CRIB) in
RIKEN-CNS. The results are reported elsewhere.10)
In the present report, we propose the detection of
not only 8 Li but also 11 B produced by the reaction
through particle identiﬁcation. Because 8 Li from elastic scattering would contaminate a true event, even
if a neutron is detected by a liquid scintillator witha pulse shape discriminator which is able to identify
a neutron or γ-ray, a recommended means of identifying low-energy ions is the dE/dx-E method. However, a dE/dx detector must be as thin as possible
so as not to stop ions in the ﬁrst detector. Conventionally, a gas counter is used for such a thin detector. Recently, a monolithic SSD detector with anouter geometry is 15 × 10 mm2 has been developed.11)
This detector consists of 1 µm pad readout SSD and508 µm SSD. Signals from the ﬁrst and second layers could be used to measure dE/dx and a total energy deposit, respectively. Such a thin SSD detector∗

Center of Nuclear Study, University of Tokyo

has never been produced. In this article, a feasibility
study of the monolithic SSD detector for the measurement of 8 Li(α, n)11 B reaction using GEANT4 simulation code12) is reported.
In the above simulation code, a gas target is ﬁlledwith helium gas at a pressure of 100 Torr and a lengthof 3 cm. The 8 monolithic SSDs are placed at the end
cap of the gas target. A 8 Li beam with an energy of
0.2 MeV/u reacts with helium nuclei along the beamaxis and 11 B is emitted.
The result of this simulation is shown in Fig. 1. In
the upper part of the ﬁgure, the 11 B detected by themonolithic SSD is shown. In the GEANT4 simulation code, 11 B is generated at the same amount in the
ground state and in the ﬁrst, second and third excitedstates. 11 B in the ground and the ﬁrst excited states
are clearly separated, while those in the second andthird excited states are impossible to distinguish. At
the same time, elastic scattering is also simulated in
the code as is seen in the lower part of the ﬁgure. 8 Li
and α nuclei are also clearly identiﬁed in this plot.
From this simulation result, we conclude that monolithic SSD is capable of inclusive measurement in a lowenergy reaction. To measure branching ratio to higher
excited states, neutron detectors are necessary. We
have started testing the monolithic SSD using an
α source.

Fig. 1. dE/dx and E detected by monolithic SSD simulated
for 8 Li(α, n)11 B reaction.

References
1) M. J. Balbes et al.: Phys. Rev. Lett. 71, 3931 (1993).

183

2) N. Hata et al.: Phys. Rev. Lett. 75, 3977 (1995).
3) M. Terasawa et al.: Astrophys. J. 562, 470 (2001).
4) X. Gu et al.: Phys. Lett. B 343, 31 (1995).
5) R. N. Boyd et al.: Phys. Rev. Lett. 68, 1283 (1992).
6) Y. Mizoi et al.: Phys. Rev. C 6206, 5801 (2000).
7) M. K-Nishimura et al.: RIKEN Accel. Prog. Rep. 35,
80 (2002).
8) S. Kubono et al.: Eur. Phys. J. A 13, 217 (2002).

1849) T. Teranishi et al.: CNS-REP-39, October (2001) p. 1.
10) M. Kurata-Nishimura et al.: RIKEN Accel. Prog. Rep.
36, 168 (2003).
11) A. Musumarra et al.: Nucl. Instrum. Methods Phys.
Res. A 409, 414 (1998).
12) Geant4 collaborations: http://geant4.web.cern.ch/geant4/

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

A fast data acquisition front-end using an FPGA device
M. WadaA fast data acquisition (DAQ) front-end was developed for laser microwave spectroscopy experiments
for laser-cooled ions in an ion trap. In this experiment, laser-induced ﬂuorescence (LIF) photons are detected by a position-sensitive photon-counting camera,
Hamamatsu PIAS-TI, used for observing an image ofeach trapped ion.1) Many commercial DAQ systems orinterface cards can be used for the simple observationof such ion crystal images. However, for spectroscopy
experiments, many additional data, such as microwave
frequency, time after laser pulse, and so on, shouldbe acquired simultaneously with the photon data andrecorded event by event for correlation analyses. Thereis no such commercial DAQ, and moreover, traditional
CAMAC systems are not suﬃcient in terms of performance, in particular, in terms of the dead time. The
counting rate of the LIF measurement is often high,typically up to 40 kcps, since a laser-cooled ion frequently repeats the excitation-deexcitation cycles witha maximum rate of 108 s−1 . If the dead time for each
event is 20 µs, approximately 80% of data is be lost.
Thus, we set ∼2 µs as an allowable dead time per event,which prevents the use of any software-based acquisition front-end.
Buﬀering acquired-event data for translating random data to blocked data, the so-called derandomization, is an important concern in the DAQ
design. Usually, the buﬀer is located in the frontend, which allows the use of a standard interface tothe back-end computer, such as Ethernet, Firewire,
USB2 or SCSI. In this case, only a high throughput is required of the interface for the de-randomized
data transfer. In the present DAQ design, however,
we use a FIFO buﬀer of a commercial PCI interface
board, ADLink PCI7300A,a) as the de-randomizing
buﬀer, which simpliﬁes the architecture of the frontend. Since PCI7300A accepts a 32-bit data input every 50 ns as long as the 16 kwords FIFO buﬀer is not
yet full, the dead time due to the data transfer to thebuﬀer is negligible.
Figure 1 shows the functional diagram of the DAQ
front-end. It has eight 12-bit ADCs for analog inputs(Analog Devices, ADS-7818), four 32-bit binary counters and 8-bit auxiliary digital inputs for tag data, anda 32-bit output port for transferring the event data to
PCI7300A in the back-end computer. A data acquisition is initiated by the ‘Trig-in’ signal, then the sequencer latches counters and digital inputs and asserts‘Conv’ signal to begin AD conversion. The latched
digital data are immediately sent to PCI7300A with
‘Strobe’ signals while the AD conversions are processeda)http://www.adlinktech.com/

Fig. 1. Functional block diagram of the DAQ front-end.

concurrently. When AD conversions are completed,these data are also transferred. These functions can be
simply realized using an FPGA (Field Programmable
Gate Array) device shown in Fig. 2. All the logic circuits can be constructed in the FPGA, so that only AD
converters and electrical buﬀers are the devices aside

Fig. 2. Physical block diagram of the DAQ front-end.

185

Fig. 3. Timing chart of the DAQ front-end.

from the FPGA. The timing chart of the front-end
device is also shown in Fig. 3.
The functions of the FPGA can be conﬁgured using
HDL (Hardware Description Language), Verilog-HDL,and the source code is, then, compiled by softwaretools which are usually provided by the FPGA device
vendor free of charge. We used an ALTERA Flex series FPGA, EPF10K30ATC144-3; MAX+PLUS II Advanced Synthesis and MAX+PLUS II Baseline are therelevant tools for the FPGA device.b) The compiled
code can be written in a conﬁguration ROM using thesame tools through a JTAG port even when the system
is in operation. One can easily modify the conﬁguration when one wants to change the structure of theevent data, for instance. Its ﬂexibility is similar tothat of a software-based acquisition device, but it isindeed a hardware device.
An example data structure of an event which isused in a laser-microwave spectroscopy experiment isshown in Fig. 4. In this case, only three ADCs areused to record the position and amplitude of the detected photon. In addition, ﬁve counters and an 8bit auxiliary input data are recorded. The event size
is six 32-bit words, so that the required throughput
when the average event rate is 40 kcps is 240 kwords/s(0.96 Mbytes/s). Although PCI7300A is capable oftransferring the data in the bus-master DMA (direct
memory access) mode, the vendor provide drivers only

for Windows and a few Linux versions and any source
codes are not opened. We wrote a simple driver for
PCI7300A under a real-time extended Linux, LinuxRTAI,c) which does not yet support the bus-master
DMA mode. The total throughput including writingoverhead to a storage device is as high as 750 kwords/s(3 Mbytes/s), which is suﬃcient for the present purpose.
The back-end computer so far used is a simple dataserver. It acquires the data from the front-end device
and stores the data to a hard disk drive, while some
online analyses are performed to produce spectra formonitoring purposes. Human interfaces for controllingthe acquisition procedure and monitoring the spectra
are carried out by LabVIEW programs on the otherPCs connected to the back-end computer via ethernet.
A fast DAQ front-end for high counting rate experiments was developed with minimum eﬀort, budget,and time using an FPGA device and a commercial PCI
interface card. The dead time per event is as small as
2 µs and the total throughput of the entire system is
750 kwords/s. The dead time is mainly determined by
the relatively slow conversion time of the AD converter
chip, and one can use faster ADCs if necessary. If one
needs more AD converters, only one input per channel
should be added to the FPGA conﬁguration and oneneeds a small increase in the dead time, 62.5 ns per
extra two channels. Another extension for using multiple front-end devices is also possible. In this case, tagwords such as an event counter and an accelerator’s rf
frequency counter, should be used for identiﬁcation of
the event at the event builder. The advantages of developing our own DAQ system are the ﬂexibility andextendability. In particular, the use of an FPGA device
allows ﬂexible conﬁguration as if it were a softwarebased system, but it runs at hardware speed.

Fig. 4. Typical event data structure.

1) T. Nakamura et al.: Opt. Commun. 205, 329 (2002).

References

b)

186

http://www.altera.com/support/licensing/c)

http://www.rtai.org

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Present status of data acquisition system ‘BabarlDAQ’for nuclear physics experiments
H. Baba,∗1 S. Takeuchi, K. Yamada,∗1 Y. Sakamoto,∗1 K. Ieki,∗1 and S. Shimoura∗2
We have introduced a data acquisition system(DAQ) BabarlDAQ.1) This system has been widelyused for nuclear physics experiments with the RIKEN
projectile-fragment separator (RIPS) and the CNS RIbeam separator (CRIB) in the RIKEN Accelerator Research Facility.
Recently, we developed detector arrays: the NaI(Tl)detector array for in-beam γ-ray spectroscopy,2) the
NaI(Tl) calorimeter for charged particles,3) and thesegmented Ge detector array,4) each of which has signals of more than a few hundred channels. CAEN
VME-type ADC modules are used in order to handle plenty of signals, because the conventionally used
CAMAC-type LeCroy FERA system is out of production. Therefore we have modiﬁed BabarlDAQ to use
the hybrid system of CAMAC and VME.5)
The characteristics of BabarlDAQ are cost eﬃciency,
ﬂexibility and good performance. The features of thissystem are as follows.
• Uses standard CAMAC and VME modules only.
• Uses personal computers (PCs) with Linux OS.
• Real-Time Linux OS for driving CAMAC and
VME.
• Network distributed data processing.
• Includes useful analysis software.
This system is divided into three main components:
the CAMAC & VME driver (Driver ), the DAQ controller (Controller ), and some on-line analyzers (Analyzer ). These components can be distributed amongsome PCs that communicate with each other throughan ethernet. The typical conﬁguration is shown in
Fig. 1. The Driver-PC is working under Real-TimeLinux (RTLinux)6) which is a real-time extension ofLinux Kernel. RTLinux has been released under the
GNU General Public License and the RTLinux OpenPatent License, and can be used for free. Using a realtime OS, the system can be kept running for a longtime with stability and high eﬃciency.
The Driver-PC reads out data from CAMAC andVME modules through the bus controllers and accumulates data into a buﬀer. This system can handle
several bus controllers: TOYO CC/7700 + CC/PCI,
Kinetic systems K3922 + K2915 PCI, SBS Bit3
618/620 PCI to VME bus adapter, and Wiener
VMEMM + PCIADA. When one buﬀer becomes full,one block of data is transferred to the Controller-PC
with the TCP/IP protocol. Using the double-buﬀer
method, data read out from the CAMAC and VME
modules can be performed during the data transfer
process to the Controller-PC. Unless both the buﬀers
become full during the data transfer, dead time is not
induced.
The Controller-PC receives the data from the
Driver-PC and puts the data into storage devices.
Then, the Controller-PC distributes data to someAnalyzer-PCs with the UDP/IP protocol. This process does not aﬀect the data acquisition performance.
The Analyzer-PC writes the transfered data fromthe Controller-PC into a shared memory, and ANAPAW or some other on-line software use on-line block
data through the shared memory.
ANAPAW is a useful analysis software which runs
under Linux OS and has been developed together with
BabarlDAQ. It has been used as the on-line and oﬀline analysis software in RIPS and CRIB experiments
in recent years, and provided us with an easy and fast
analysis in both on- and oﬀ-line analyses.
ANAPAW consists of three components as shownin Fig. 2. The ﬁrst is the PAW7) component. Users
can use not only ANAPAW commands but also PAW
commands for analysis. The second is the ANAPAW library which has a main analysis routine pro-

Fig. 1. Configuration of BabarlDAQ system.
∗1∗2

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

Fig. 2. Overview of ANAPAW components.

187

Table 1. Access times of CAMAC and VME from developed device driver.
CAMAC
no data transfer
single readsingle write
quasi block read
block read

TOYO CC/7700 + CC/PCI
4.1 µs
6.3 µs
6.0 µs4.8 µs/ch + 1.6 µs

Kinetic K3922 + K2915
7.8 µs10.2 µs
9.9 µsVME
32 bit single read
32 bit single write
32 bit DMA read

Wiener VMEMM + PCIADA
1.9 µs
1.2 µsSBS Bit3 620 PCI-VME
2.4 µs2.0 µs0.4 µs/ch + 1.9 µs

viding original analysis commands and I/O routines.
Basically the I/O routines of ANAPAW are createdto adapt BabarlDAQ with a shared memory and asemaphore which are able to send and receive data
between BabarlDAQ and ANAPAW. Once the I/O
routines are modiﬁed to ﬁt another DAQ system, online analysis is available in the system. The last is theuser-source component which is modiﬁed by experimental users to match with experimental conditions.
This component consists of a main routine and analysis routines. The main routine is executed by an eventloop routine in ANAPAW to check an event size and toput detector data into analysis routines. The analysis
routines convert raw data to numerical data and calculate physical values. In addition, an NTUPLE format
is available by modifying an NTUPLE-I/O routine in
the user-source component.
For on-line use, ANAPAW reads out data from ashared memory in the Analyzer-PC, while it reads out
data from ﬁles for oﬀ-line analysis. During on/oﬀ-line
analysis, users prepare and modify histogram deﬁnition ﬁles. In those ﬁles, one-dimensional (1D) and twodimensional (2D) histograms, logical gates and 1D/2D
gates are deﬁned. Periodical displays of 1D histograms
and scatter plots are available and operation for histograms is also available using ANAPAW commands.
Since the environments of oﬀ-line analysis are the sameas those of on-line analysis, users can utilize experimental parameters and histogram deﬁnition ﬁles foroﬀ-line analysis.
We report the performance of the Driver below. The
Driver detects a CAMAC LAM signal or a VME IRQ
signal every 40 µs using the RTLinux periodic task to

188

2.6 µs/ch + 8.0 µs

determine the end of module conversion. While theperiodic task in standard Linux takes up to 600 µs
to start a handler, there could easily be a more than
20 ms latency. On the other hand, the RTLinux periodic task can run within 35 µs of its scheduled time.
Therefore, the response time of the CAMAC LAM signal or VME IRQ signal by the RTLinux periodic task
is 20 µs on average. In addition, we have developed
device drivers that run under RTLinux to access every
controller. Access times of CAMAC and VME througheach controller are shown in Table 1.
The main source of dead time in BabarlDAQ is theaccess time of CAMAC and VME modules. It increases in proportion to the number of readout channels, because only one CPU reads every channel oneby-one. To reduce the dead time, we are developing
an eventbuild-type DAQ system in which some CPUs
read out data in parallel and construct complete event
data later. The new eventbuild-type DAQ system will
be implemented during the year 2004.
References
1) H. Baba et al.: RIKEN Accel. Prog. Rep. 34, 221(2001).
2) S. Takeuchi et al.: RIKEN Accel. Prog. Rep. 36, 148(2003).
3) M. Tamaki et al.: CNS-REP-59, July (2003), p. 76.
4) S. Shimoura et al.: CNS-REP-45, July (2002), p. 5.
5) H. Baba and S. Shimoura: CNS-REP-45, July (2002),
p. 53.
6) M. Barabanov and V. Yodaiken: Linux Journal 34, 19(1997).
7) CERN Program Library : unpublished.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Network and computing environment for RIKEN Accelerator
Research Facility
T. Ichihara, Y. Watanabe, K. Yoshida, and A. Yoshida
The advanced computer network1) started operationin 2002 at the RIKEN Accelerator Research Facility(RARF). After that, RIKEN was connected to the Super Sinet (Sinet Information Network)2) at the bandwidth of 1 Gbps in July 2003. The previous bandwidthof the Wide Area Network connection was 100 Mbps.
As a result, a huge amount of data can be transfered via the Internet using the newly connected Super
Sinet.
Figure 1 shows the current conﬁguration of the
RARF advanced computer network. Between the
RARF internal network and external Internet, a ﬁrewall (PIX 525) has been installed to maintain security. The bandwidth of the RARF ﬁrewall and RIKEN
central LAN switch was increased from 100 Mbps to 1
Gbps in order to correspond to the increased bandwidth of the Super Sinet.
Figure 2 shows the current conﬁguration of theUNIX cluster servers of RARF for general users.
Nine nodes of UNIX servers, four of which are True
64 UNIX (alpha), three of which are RedHat Linuxand two of which are Solaris, are connected via
the Gigabit or 100 Mbps Ethernet. RARFAXP isthe central server for e-mail, text processing, user
home pages and general computing. RARFAX1,RARFAX2 and RARFLX1-3 are used mainly for intensive data analysis, large-scale calculations and user
terminals. RARFSUN is a gateway computer for accessing the internal private network of RARF using
SSH. RARFNFS0 is a dedicated Network File Service(NFS) server which is equipped with 2.8 TB + 1.7 TB
Raid5 work disks. The Veritas File System (VxFS),
which is a logging ﬁle system, was installed for theraid ﬁle systems in order to achieve high performancein ﬁle operation.
Secure Shell (SSH) protocol has been installed for
all the nodes. The use of SSH is requested for remotelogin and ﬁle transfer to ensure security against network packet sniﬃng. The Secure Sockets Layer (SSL)encrypted Internet Message Access Protocol (IMAPS)
service is available at the RARFAXP. In order to pre-Fig. 2. Configuration of the RARF UNIX cluster.

vent virus infections via e-mail, a virus-detecting and-eliminating system is installed in the node RARFAXP.
Most of the RARF users have e-mail addresses ofusername@rarf.riken.jp or username@riken.jp.
The ﬁrst one represents an e-mail address of the
RARF mail server (RARFAXP) and the second one
represents an e-mail address of the RIKEN mail server(postman). Note that the operation of the e-mail forwarding service to the RARF VMS system, which forwards e-mail sent to the old VMS systems (RIKVAX
and RIKAXP), was terminated in November 2003.
An anonymous ftp service is operating at RIKSUN(ftp.riken.go.jp) which archives 1 TB of useful software
for research, including Linux and TeX distributions,
GNU software and large collections of free software for
PC, Macintosh and UNIX systems.
References
1) T. Ichihara et al.: RIKEN Accel. Prog. Rep. 36, 199(2002).
2) http://www.sinet.ad.jp/

Fig. 1. Configuration of the RARF Adovanced Network.

189

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RIKEN Accel. Prog. Rep. 37 (2004)

Application of an in-air high-resolution PIXE system todirect speciation of Cr and Fe
K. Maeda, K. Hasegawa,∗1 H. Hamanaka,∗2 M. Tsuji,∗3 and S. Murao∗4
Particle-induced X-ray emission (PIXE) analysis
with high energy resolution is one of the most eﬀective tools for direct investigations of chemical bonding states of atoms in target materials. We have developed a compact spectrometer system consisting ofan analyzing crystal and a position-sensitive proportional counter (PSPC) for high-resolution PIXE measurements in air of atmospheric pressure.1) The system is most appropriate for K-X rays of third-period
elements. As for the main components, it is possible
to distinguish chemical species within ﬁve seconds. A
small quantity of the sample, 1 mg and 10 mm2 , is sufﬁcient for measurements.
This time we have examined the feasibility of thissystem for the direct speciation of 3d transition elements. We report here the preliminary results obtained
from the measurements of the Kβ spectra of Cr andFe.
The experimental setup presented in the previous
report2) is used. A target sample is placed in air andbombarded with a 2.1 MeV proton beam of 3 mm diameter, which is extracted from a vacuum beam line
through a 7-µm-thick Al exit window. X-rays are
diﬀracted by a cylindrically curved crystal of v. Hamos
geometry and detected by the PSPC. A narrow slitof 0.4 mm width is placed between the target and the
crystal, at a position very close to the proton beam
spot on the target. Third-order diﬀraction by a Ge(111) crystal of 150 mm in radius of curvature (r) wasused for the measurements of Cr Kβ, while ﬁrst-orderdiﬀraction by a LiF (420) crystal of 200 mm r was used
for the measurements of Fe Kβ. Proton beam current
was 30–60 nA. A gas mixture of Xe : CO2 (9 : 1) wasused as the counter gas.
Figure 1 shows the Cr Kβ spectra of Cr metal andCr2 O3 . A diﬀerence in chemical state between themetal and oxide Cr is observed in a relative intensity ofa low-energy satellite Kβ’. The main line Kβ1,3 resultsfrom the 3p–1s electron transition. The satellite Kβ’
is explained by the promotion of unpaired 3d electrons
to the conduction band or by the exchange interaction
between unpaired 3d electrons and 3p holes.3–5) Thus,
Kβ’ can be used as a good indicator of the bonding
states of 3d elements.
As well as the Kβ spectra of Cr, a diﬀerence in Kβ’
∗1
∗2
∗3
∗4

MIS Ltd.
Faculty of Engineering, Hosei University
Research Center for Carbon Recycling and Utilization,
Tokyo Institute of Technology
Institute for Geo-Resources and Environment, National
Institute of Advanced Industrial Science and Technology(AIST)

Fig. 1. Cr Kβ spectra. Diﬀraction angle θ is 〜74◦ . One
channel corresponds to 0.53 eV around the Kβ1,3 line
(5.95 keV).

intensity is clearly observed between the Fe Kβ spectraof the metal and oxide, as shown in Fig. 2.
The diﬀerence in intensity distribution of spectrum
between two oxides, Fe2 O3 (Fe3+ ) and FeO (Fe2+ ), issmall. In addition, a high background mainly causedby γ-rays emitted from the Al exit foil masks the difference. However, after background subtraction, nor-

Fig. 2. Fe Kβ spectra of Fe metal and Fe2 O3 , and background spectra measured with Co and Si targets andwithout a target. Diﬀraction angle θ is 〜77◦ . One
channel corresponds to 0.38 eV around the Kβ1,3 line
(7.06 keV). The accumulated beam charges are 80 µC
for Fe, 200 µC for Fe2 O3 , 200 µC for Co, 70 µC for Si,
and 20 µC for the case without a target.

191

malization and smoothing of the measured spectra, thediﬀerence became evident, as shown in Fig. 3. In accordance with the data obtained by the X-ray ﬂuorescence method,3) the Kβ’ intensity of Fe2 O3 is slightly
higher than that of FeO. The PIXE measurement wasalso carried out using a green biotite sample shown in
Fig. 3. The Kβ spectrum of the sample resembles thatof FeO, which is in consistent with the generally accepted explanation of the oxidation state (2+) of Fe in
biotite.
We have assured that the background of the Fe Kβ
spectra is markedly reduced by a factor of 4, when a

7-µm-thick Kapton foil is used as the exit window instead of the Al foil. However, Kapton is not as strongas Al against damage caused by proton impact. Probably the beam current should be maintained at less than
20 nA for the Kapton window. On the other hand, theAl window withstands the proton beam of > 100 nA.
The Kβ spectra shown in Figs. 1–3 were obtained at
the accumulated beam charge of 70–300 µC and themeasuring time of 20–80 min. The sensitivity of thespeciation of the 3d elements using this system is not
as good as that of the third-period elements. However,
it is expected that the sensitivity could be much improved if a multistacked PSPC assembly with a large
sensitive area6) is combined with a curved crystal of
Johann or Johansson geometry.
References

Fig. 3. Fe Kβ spectra of Fe2 O3 , FeO and green biotite.
The biotite was collected from the Tosham polymetallic
deposit, India.

192

1) K. Maeda et al.: Adv. X-Ray Chem. Anal. Jpn. 34, 89(2003).
2) K. Maeda et al.: RIKEN Accel. Prog. Rep. 36, 205(2003).
3) A. S. Koster and G. D. Rieck: J. Phys. Chem. Solids
31, 2505 (1970).
4) K. Tsutsumi et al.: Phys. Rev. B 13, 929 (1976).
5) H. Eba and K. Sakurai: Adv. X-Ray Chem. Anal. Jpn.
33, 253 (2002).
6) K. Hasegawa et al.: Trans. Soc. Instrum. Control Eng.,39, 11 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Gamma rays from iron, aluminum and rock targets bombarded
by 210 MeV protons
E. Shibamura,∗1 N. Hasebe,∗2 M. Kobayashi,∗2 T. Miyachi,∗2 H. Okada,∗2 T. Hiramoto,∗2 S. Murasawa,∗2
A. Nagashima,∗2 O. Okudaira,∗2 N. Yamashita,∗2 and J. Yasutani∗2
Planetary bodies bombarded by cosmic rays emit
γ rays with energies characteristic to surface materials. Measuring the γ rays determines the chemical concentration of the planetary surface. Remote sensing
γ-ray spectroscopy has been employed to study planetary bodies,1–4) for example, by Japanese lunar orbiter
SELENE. Nuclear spectroscopic analysis,5) however,requires quantitative data on major elements over awide range of concentrations. To improve the analysis, beam experiments with protons simulating thecosmic-ray exposure play an important role.
Cosmic-ray irradiation environments of planetary
surfaces are simulated using proton beams and thicktargets.6) We used four thick targets, namely, Fe andAl targets, which are 0.5 × 0.5 × 0.5 m3 in volume, andgabbro and granite targets, which are 0.7×0.7×0.7 m3
in volume. Each target was irradiated with 210 MeV
proton beams from the Riken Ring Cyclotron. γ raysfrom the targets were observed using a Ge detector
with a volume of 113 cm3 placed 25 cm away from theirradiated surface.
A typical energy spectrum of γ rays in the Fe target is shown in Fig. 1 together with that calculatedby Geant4. There were high background γ rays whose
sources include naturally radioactive materials as wellas γ rays induced by recoiled protons and neutrons
from massive materials in the experimental facility.
The ratios of major peak areas in the experiment tothose in the calculation are shown in Fig. 2. The experimental values are lower than the calculated ones
except the peak at 1238 keV. The diﬀerences are notfully understood, but are in part explained by the simpliﬁcation of material disposition in the calculation andsurrounding materials in the exposure room. The nuclear data libraries for generating neutron-induced γrays would be acceptable regarding the major peaks
from the Fe target. Some minor peaks in the calculation are not seen in the experiment. The values
employed in the libraries for other nuclides were deﬁcient, implying the necessity to improve the γ-rayand neutron-related libraries. This experiment provides fundamental data for calibrating the SELENE
GRS and nuclear library, which will be beneﬁcial tolunar and planetary γ-ray spectroscopies. Further experiments, however, are necessary to improve the accuracy of planetary γ-ray spectroscopy.

Fig. 2. Ratios of peak areas in experiment to those in calculation.

References

Fig. 1. Comparison of energy spectra of gamma rays from
Fe target between experiment (left axis) and calculation(right axis).
∗1∗21) T. M. Harrington et al.: Nucl. Instrum. Methods 118,
401 (1974).
2) W. C. Feldman et al.: Nucl. Instrum. Methods Phys.
Res. A 422, 562 (1999).
3) W. V. Boynton et al.: Science 297, 81 (2002).
4) N. Hasebe et al.: Adv. Space Res. 23, 1837 (1999).
5) R. C. Reedy: Proc. 9th Lunar Planetary Science Conf.,(1978) p. 2961.
6) N. Yamashita et al.: Adv. Space Res. 31, 2359 (2003).

College of Health Science, Saitama Prefectural University
Advanced Research Institute for Science and Engineering,
Waseda University

193

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RIKEN Accel. Prog. Rep. 37 (2004)

QCD and dimensional deconstruction
M. A. Stephanov∗In this work we consider an eﬀective theory describing pions and a tower of vector and axial vector mesons
based on a large number of hidden local symmetries.
In the limit K → ∞ this theory can be viewed asa discretization (or, deconstruction) of a classical 5 dYang-Mills theory. Several nontrivial properties of thehadronic resonances, such as, e.g., vector meson dominance have a simple explanation within the model.
The model under consideration in Ref. 1 is describedby the following Lagrangian
L=

K+1


fk2 Tr|Dµ Σk |2 −

k=1

K

1
k=1

2

 k 2Tr Fµν
.

(1)

The covariant derivatives are deﬁned askkDµ Σ = ∂µ Σ − i(gAµ )

k−1

k

k

k

Σ + iΣ (gAµ ) .

(2)

A shorthand notation is used for the product of thegauge ﬁeld Aµ = Aaµ τ a /2 and its coupling constant:= 0.
gk Akµ ≡ (gAµ )k . We assume A0µ = AK+1µ
The model contains K + 1 nonlinear sigma modelﬁelds Σk ∈ SU(2) (or, in general, SU(Nf )), interacting
via K gauge boson ﬁelds Akµ . The model has a chiralSU(2) × SU(2) symmetry and an SU(2)K local symmetry. This model is a natural generalization of modelsof hidden local symmetry.2)
Consider the limit K → ∞. In this case we canreplace the discrete variable k by a continuum
variable

a.
If
the
limit
which we shall call u: u = k − K
2
K → ∞ is performed in the following way K → ∞,and a → 0, while Ka ≡ 2u0 is ﬁxed, then u becomesa continuum replacement for k. If the fk and gk aresmooth functions of k we can also replace them byfunctions of u.
The continuum limits for important physical quantities in terms of the functions f (u) and g(u) are as
follows. The pion decay constant is given by 4fπ−2 = +u0
duf −2 (u) .
−u0
The vector/axial vector resonance masses are givenby the eigenvalues ofg(f 2 (gbn ) ) = −m2n bn .

(3)with Dirichlet boundary conditions bn (±u0 ) = 0 (since= 0).
we set A0µ = AK+1µ
The coupling of the n-th vector meson to 2 pions isgiven by
fπ2 +u0 dug(u)bn (u).
(4)
gnππ =
4 −u0 f 2 (u)From this equation it can be easily seen that the coupling of higher vector mesons are suppressed by the∗

Physics Department, University of Illinois at Chicago, USA

overlap integral of fast oscillating wave-function bn (u)and smooth g(u)/f 2 (u). This provides a natural explanation of the observed vector meson dominance ofthe pion formfactor.
The theory with K
1 can be also considered as adiscretized (or deconstructed3) ) ﬁve-dimensional continuum gauge theory in curved spacetime. The variable u plays the role of the ﬁfth dimension and Σ’s canbe interpreted as the corresponding gauge ﬁeld linkvariables, Σk ≈ 1 + iaA5 (u). The action of the model
can be written as:


1
(5)
S = − d5 x |g| 2 TrFµ̂ν̂ F µ̂ν̂ ,2gwhere µ̂, ν̂ are 5d Lorentz indices and |g| is the determinant of the metric tensor. The metric has a warped
form, with f 2 g 2 playing the role of the warp factor
ds2 = −du2 + f 2 g 2 ηµν dxµ dxν .

(6)

The correlators of conserved currents in this theory
can be computed by using a prescription essentially
identical to the AdS/CFT one. Namely, the generating
functional for the correlation functions of the currents
is equal to the action of a solution to the classical ﬁeld
equations, with the sources serving as the boundary
values for the classical ﬁelds.
For a metric which at the boundaries, u → ±∞,approaches AdS5 form, i.e., f (u) → (Λ/g5 )e|u| , withg(u) → g5 , the vector-vector current polarization operator is given by:1ΠV (Q2 ) = − 2 ln(Q2 ),
g5

Q2

Λ2 .

(7)

Matching this to QCD resultΠV (Q2 ) = −Ncln(Q2 ),
24π 2

(8)

where Nc is the number of colors, one obtains
1
Nc
=
.
2
g5
24π 2

(9)

In particular, this means that such a theory is weakly
coupled when Nc → ∞. It is natural to expect thisproperty from a theory dual to QCD.
References
1) D. T. Son and M. A. Stephanov: arXiv:hep-ph/0304182.
2) M. Bando, T. Kugo, S. Uehara, K. Yamawaki, andT. Yanagida: Phys. Rev. Lett. 54, 1215 (1985); M.
Bando, T. Fujiwara, and K. Yamawaki: Prog. Theor.
Phys. 79, 1140 (1988).
3) N. Arkani-Hamed, A. G. Cohen, and H. Georgi: Phys.
Rev. Lett. 86, 4757 (2001).

195

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RIKEN Accel. Prog. Rep. 37 (2004)

Single spin asymmetry in inclusive D meson production at RHIC
K. SudohDirect measurement of the polarized strange quark
density is crucial for the understanding of the ﬂavor
structure of the polarized parton distribution functions(PDFs) and provides a clue to resolving the proton
spin puzzle. The charged current reaction such as W ±production is eﬀective for extracting the ﬂavor decomposed PDFs, because the W ± boson changes the ﬂavor
of partons.
Here, we propose charm quark production in parityviolating processes. In s-channel W production, there¯ + d(u)¯are processes, ∆u(∆d)→ W + → s̄c, which
are similar to those of conventional W production.
Moreover, there are processes,a) ∆s(∆u) + u(s) → dc,¯ + d(s)¯ → ūc, and ∆s(∆s̄) + s̄(s) → c̄c, in the∆s(∆d)t, u-channel W exchange process, and ∆s(∆g)+g(s) →W − c in charm-associated W production, which aresensitive to the polarized strange quark distribution∆s(x, Q2 ). In the unpolarized case, there are additional parity-conserving processes which are pure QCD
processes: gg → c̄c and q q̄ → c̄c. Therefore, in order toexamine the sensitivity of ∆s(x, Q2 ), we investigatedinclusive D meson production in unpolarized protonpolarized proton collisions at RHIC.
The single spin asymmetry is deﬁned asADL ≡[dσ− − dσ+ ]/dpTd∆σ/dpT=,[dσ− + dσ+ ]/dpT
dσ/dpTparametrizations; AAC,1) BB,2) GRSV,3) LSS.4) The
unpolarized cross section is dominated by the QCD
gluon-gluon fusion process, and it rapidly decreases
with pT . On the other hand, the polarized cross sections do not strongly depend on pT . Note that thepolarized cross sections are dominated by the u quarkassociated process, since the momentum fractions forboth protons are integrated in this analysis.
√ In Fig. 2, the single spin asymmetries are shown at
s = 500 GeV with various parametrization modelsof the polarized PDFs. The expected statistical error
in Fig. 2 is estimated using the designed data of thebeam polarization (P = 70%), the integrated luminosity (L = 800 pb−1 ), and the reconstruction eﬃciency(ε = 50%), together with the value of the unpolarized cross section. We can see that the parametrization model dependence on asymmetry is measurable
in large pT regions. Therefore, it might provide another test of the parametrization model of the polarized PDFs.
However, the sensitivity of ∆s(x, Q2 ) is small, since
the valence quark contribution is dominant in the xintegrated asymmetry. Some kinematical improvements to extract ∆s(x, Q2 ) are needed.

(1)

where dσ−(+) is the spin-dependent diﬀerential crosssection with negative (positive) helicity for protons.
pT is the transverse momentum of D meson. The crosssections and asymmetry are calculated in the PHENIX
acceptance; the rapidity range |η| ≤ 0.35, and Q2 is set
as p2T .
We show√ the cross sections in Fig. 1 as a functionof pT at s = 500 GeV. The upper bold line andfour lower lines represent the unpolarized cross section and the polarized cross sections, respectively. For
the polarized PDFs, we adopted the following fourFig. 2. Single spin asymmetries with statistical error ex√
pected at s = 500 GeV and L = 800 pb−1 .

References
1) Asymmetry Analysis Collaboration, Y. Goto et al.:Phys. Rev. D 62, 034017 (2000).
2) J. Blümlein and H. Böttcher: Nucl. Phys. B 636, 225(2002).
3) M. Glück, E. Reya, M. Stratmann, and W. Vogelsang:
Phys. Rev. D 63, 094005 (2001).
4) E. Leader, A. V. Sidorov, and D. B. Stamenov: Eur.
Phys. J. C 23, 479 (2002).
a)Fig. 1. The pT distribution of cross sections for the process√p
p → DX at s = 500 GeV.

196

In the numerical calculation, all processes such as Cabbibo
corrections, neutral current interaction diagrams, and interferences among W , Z 0 , and γ are included in a leading orderof the coupling constant.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)∆g(x) uncertainty from prompt photon production at RHIC Spin
M. Hirai
Determination of polarized gluon distribution ∆g(x)from polarized deep inelastic scattering (DIS) data is
insuﬃcient, since the gluon contribution is indirect andsmall.1) One of the processes that the gluon distribution predominantly contributes to is the prompt photon production which is measured by the RHIC Spin.
This report explains the eﬀectiveness of this process
for the ∆g(x) determination in terms of uncertainties
of polarized parton distribution functions (PDFs).
In order to indicate the constraint of prompt photon
data on the gluon distribution, I compare the uncertainty of spin asymmetry AγLL with expected statistical errors. The asymmetry uncertainty indicates theaccuracy of a predicted value with polarized PDFs,
which comes from PDF uncertainties. On the other
hand, the expected statistical error can be estimatedusing well-determined unpolarized PDFs, which meansa constriction for the asymmetry uncertainty.
The spin asymmetry is deﬁned as the cress section
ratio AγLL = ∆σ/σ. By the factorization theorem, thepolarized cross section ∆σ is expressed asd∆σ̂ abd∆σ =∆fa (x1 ) ⊗ ∆fb (x2 ) ⊗
,
(1)
d pT
dpT
a,b

where ⊗ denotes the convolution integral. ∆σ ab is
the partonic cross section (a + b → γ + X), which
is precisely calculated by perturbative QCD. In orderto reduce a theoretical uncertainty, this cross section
is calculated at the next-to-leading order.2) The crosssection is integrated over the rapidity bin |η| < 0.35.
This rapidity cut corresponds to the acceptance of the
PHENIX detector. ∆fa (x) is the polarized PDF of theparton a. The uncertainty of the cross section comesfrom these polarized PDF uncertainties, which are estimated by the Hessian method.
On the other hand, the expected statistical error
δAγLL can be estimated by
1
√
,
(2)
P1 P2 Lint σ
where σ is the unpolarized cross section integrated
over each pT bin, P1,2 is the beam polarization (P1 =P2 = 0.7), and L√int is the integrated luminosity (320
and 800 pb−1 at s = 200 and 500 GeV, respectively).
These values are taken from design values of an RHIC
Spin experiment.3)
Figure 1 shows a comparison between asymmetry√
uncertainty and expected statistical errors at s = 200
and 500 GeV. The covered area with dashed curves
is obtained by current polarized PDF uncertainties,1)
and the asymmetry uncertainty is mostly composedof gluon uncertainty. In practice, the asymmetry uncertainty from quark and antiquark distributions is

Fig. 1. Comparison between the asymmetry uncertainty
and expected statistical errors.

smaller than the statistical errors. This indicates thatthe gluon uncertainty is primarily constricted by including the prompt photon data.
Furthermore, the covered area with solid curves is
estimated by the constricted gluon uncertainty withoverhaul factor 1/16 and all quark and antiquark uncertainties. This factor corresponds to the statistical√errors in the region pT = 10–20 GeV. xT (= 2pT / s)would approximate the Bjorken xBj around the central region, thus this fact means that these data constrain the gluon distribution
in the speciﬁc xBj region:√xBj = 0.1–0.2 at s = 200 GeV and 0.04–0.08 at
500 GeV.
Finally, the constricted uncertainties of the gluon
distribution and the spin asymmetry are shown in
Fig. 2. Although these factors are roughly estimated,
this ﬁgure indicates that the prompt photon production is eﬀective for reducing the gluon uncertainty.

δAγLL =

Fig. 2. Uncertainties from DIS data and prompt photon
data. Left figure shows the polarized gluon distribution with its uncertainty, and right figure is the spin
asymmetry. Shaded area is estimated with the factor
1/16.

References
1) M. Hirai, S. Kumano, and N. Saito, Asymmetry Analysis Collaboration: hep-ph/0312112.
2) L. E. Gordon and W. Vogelsang: Phys. Rev. D 48, 3136
(1993).
3) G. Bunce et al.: Ann. Rev. Nucl. Part. Sci. 50, 525(2000).

197

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RIKEN Accel. Prog. Rep. 37 (2004)

On a negative AπLL at moderately large p⊥ †W. Vogelsang
The determination of the nucleon’s polarized gluon
density is a major goal of current experiments withlongitudinally polarized protons at RHIC.1) It can beaccessed through measurement of the spin asymmetriesdσ ++ − dσ +−
d∆σ
=
,
ALL =
dσ
dσ ++ + dσ +−(1)

for high transverse momentum (p⊥ ) reactions suchas pp → πX. In Eq. (1), σ ++ (σ +− ) denotes the
cross section for scattering of two protons with same
(opposite) helicities. High p⊥ implies large momentum transfer, and the cross sections for such reactions
may be factorized into long-distance pieces that contain the desired information on the (spin) structure of
the nucleon, and short-distance parts that describe thehard interactions of the partons and are amenable to
QCD perturbation theory (pQCD). Very recently the
Phenix collaboration has presented ﬁrst preliminary
data2) for AπLL . They are consistent with a signiﬁcant(up to a few per cent) negative asymmetry in the region p⊥ ∼ 1 ÷ 4 GeV. Even though the experimental
uncertainties are still large and leave room for a different behavior of AπLL , the new data motivate us toentertain the unexpected possibility of AπLL being negative. As we will show now, within pQCD at leading
power, there is a lower bound on the asymmetry of
about −10−3 .
We consider the LO cross section integrated over all
rapidities η and take Mellin moments in x2T = 4p2⊥ /Sof the cross section:
 1
 N −1 p3⊥ d∆σ ππ∆σ (N ) ≡dx2T x2T
.
(2)
dp⊥
0
One ﬁnds:∆σ π (N ) =


a,b,c

N

Here, A represents the contributions from gg → gg
and gg → q q̄, BN the ones from qg → qg, and C N thosefrom the (anti)quark scatterings.
Being a quadratic form in ∆g N +1 , ∆σ π (N ) possesses an extremum, given by the condition
AN ∆g N +1 = −BN .

198

min

It is then straightforward to perform a numerical
Mellin inversion of this minimal cross section. The
minimal asymmetry resulting from this exercise is negative indeed, but very small: in the range p⊥ ∼1 ÷ 4 GeV its absolute value does not exceed 10−3 .
The ∆g in Eq. (5) that minimizes the asymmetry is
shown in Fig. 1, compared to ∆g of the GRSV LO“standard” set.3) One can see that it has a node andis smaller than the GRSV one, except at large x.
Even though we have made some approximations
in deriving the bound in Eq. (6), we do believe thatit exhibits the basic diﬃculty with a sizable negative
AπLL at moderate p⊥ : the fact that the cross section
is a quadratic form in ∆g eﬀectively means that it isbounded from below. Eﬀects like NLO corrections,4)
choice of scales, and realistic range of rapidity may
be thoroughly addressed in a “global” NLO analysis of
the data, taking into account the results from polarized
DIS as well. We have performed such an analysis, andit conﬁrms the ﬁndings of our simple example above.

c,N∆aN +1 ∆bN +1 ∆σ̂ab
Dcπ,2N +3 , (3)c,Nwhere the ∆σ̂ab
are the x̂2T -moments of the partonic
1cross sections and, as usual, f N ≡ 0 dx xN −1 f (x) forthe parton distribution and fragmentation functions.
Explicitly, the dependence on the moments ∆g N is2∆σ π (N ) = ∆g N +1 AN + 2∆g N +1 BN + C N . (4)†The coeﬃcient AN is positive, and Eq. (5) describes a
minimum of ∆σ π (N ), with value 2∆σ π (N )
= − BN /AN + C N .
(6)

(5)

Condensed from the article in hep-ph/0310197, accepted for
publication in Phys. Rev. Lett.

Fig. 1. ∆g (x, µ = 2.5 GeV) resulting from Eq. (5) (solid).
The dashed line shows the GRSV LO “standard” ∆g.3)

References
1) G. Bunce, N. Saito, J. Soﬀer, and W. Vogelsang: Annu.
Rev. Nucl. Part. Sci. 50, 525 (2000).
2) A. Bazilevsky: talk presented at the Xth Workshop on
High Energy Spin Physics (Spin-03), Dubna, Russia,
2003-9.
3) M. Glück et al.: Phys. Rev. D 63, 094005 (2001).
4) B. Jäger et al.: Phys. Rev. D 67, 054005 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Threshold resummation for heavy-flavor photo-production
H. Yokoya∗1 and W. Vogelsang∗2
The polarized gluon distribution function ∆g(x, Q2 )may play an important role for understanding the spin
structure of the nucleon. Data from polarized DIS, accumulated over more than two decades, constrain ∆g
only very little. There are several new experiments
now dedicated to accessing gluon polarization. One
reaction, to be studied by COMPASS at CERN, isµ p → cc̄X, polarized heavy-ﬂavor production. Hereone takes advantage of the photon-gluon fusion process which is expected to dominate the cross section.
First-order QCD corrections to γg → cc̄ were foundto be sizable.1,2) This raises questions concerning therelevance of yet higher orders. We address this issue
by considering all-order threshold resummation corrections to the reaction. The perturbative expansion forthe photon-gluon fusion cross section reads:
e2Q ααs (m2 )(0)(ρ)(∆)σ̂γg (ρ) =(∆)fγgm2(1)(ρ) + · · · ,(1)+ 4παs (m2 )(∆)fγg
where ρ = 4m2/ŝ and we have chosen the renormalization scale as the mass m of the heavy quark. f (0) is theleading order (LO) contribution, and f (1) is the nextto-leading order (NLO) coeﬃcient functions. Near partonic threshold, ρ → 1, f (1) develops large logarith√
mic terms, ∝ ln2 (8β 2 ) and ln(8β 2 ), where β = 1 − ρ.
These are associated with soft-gluon emission.
We perform resummation of these threshold corrections following the method used by Boncianiet al.3)
1
N −1
We go to Mellin moment space, fN = 0 dρρ
f (ρ),
where the threshold region corresponds to N → ∞ andthe large logarithms appear as ln2 N or ln N . The resummed coeﬃcient function is given by


(0)
res
Coul.
= (∆)fN + 4παs (m2 )(∆)fN
(∆)fN



αs (m2 )× 1+
C ∆N +1 αs (m2 ) , (2)πCoul.
corresponds to the Coulomb gluon exwhere fNchange contribution, and C is a constant. The radiative factor ∆N has an exponential form. It gives all
the threshold logs. Its explicit form is given in Ref. 3.
The unpolarized coeﬃcient functions are shown in
Fig. 1, versus η = (1 − ρ)/ρ. At small η, i.e. nearthreshold, the NLO contribution strongly increases the
cross section, compared to LO. The O(αs ) expansionof the resummed result is in good agreement with full
∗1
∗2

Fig. 1. Coeﬃcient functions for the unpolarized crosssection at LO (dotted), LO+NLO (dashed), andfor the O(αs ) expansion of the resummed result(dot-dashed).

NLO, except of course at large η.
The polarized coeﬃcient functions are shown in
Fig. 2. We ﬁnd similar features as in the unpolarizedcase.
Our results demonstrate that the NLO correction isdominated by the threshold logarithms. This justiﬁes
their all-order resummation as given by Eq. (2), forwhich we hope to publish results in the near future.

Fig. 2. Same as Fig. 1, but for the polarized case.

References
1) R. K. Ellis and P. Nason: Nucl. Phys. B 312, 551 (1989).
2) I. Bojak and M. Stratmann: Phys. Lett. B 443, 411(1998); Nucl. Phys. B 540, 345 (1999).
3) R. Bonciani et al.: Nucl. Phys. B 529, 424 (1998).

Department of Physics, Hiroshima University
Physics Department, Brookhaven National Laboratory,
USA

199

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RIKEN Accel. Prog. Rep. 37 (2004)

The parton structure of the nucleon and precision determination of
the Weinberg angle in neutrino scattering†
S. Kretzer
An important open question in particle physics inrecent years has been the significance of the “NuTeV
anomaly”—a 3σ deviation of the measured sin2 θW(0.2277 ± 0.0013 ± 0.0009) reported in Ref. 1 from the“standard model value” (0.2227 ± 0.00037), based on
the world average of other measurements. No consistent picture has yet emerged in spite of an extensive
literature on this subject.2) The measurement in Ref. 1
is closely related to measuring the Paschos-Wolfensteinratio,3) which provides the theoretical underpinning of
the analysis. For an isoscalar target, the parton model
relates the Paschos-Wolfenstein ratio R− to the Weinberg angle by
R− ≡

ν
ν̄
− σNC
σNC
1
 − sin2 θW .
ν − σ ν̄
σCC
2
CC

(1)

For the accuracy required to test the consistency of theSM, one needs a quantitative analysis based on a thorough revision of the relevant perturbative cross sections4) and non-perturbative parton distribution functions.5)
A particularly elusive source of uncertainty so far2)
has been that associated with a possible strangenessasymmetry in the parton structure of the nucleon. A
positive (negative) asymmetry, as measured by the momentum integral −S ≡ dx x [s(x) − s̄(x)] ,(2)
would reduce (increase) the NuTeV discrepancy. A
devoted global analysis of parton distribution functions5) has now indicated that this asymmetry is oforder |[S − ]|  10−3 . The sign of [S − ] cannot be determined reliably from global data: The central fit inRef. 5 prefers a positive value but for a conservative
theoretical error estimate a broad range around thebest fit value has to be considered. To quantify the
impact of these new findings on R− , we combine themwith a recently completed state-of-the-art program forcalculating neutrino cross sections in next-to-leadingorder QCD, including target mass and charm mass corrections.4) The results are summarized in Table 1. The
shift based on the central fit B can bridge up to about
1.5σ of the overall 3σ discrepancy between the NuTeV
result and the world average of other measurements of†200

Condensed from the article in RBRC-328, submitted toPhys. Rev. Lett.

Table 1. Shifts in R− , calculated with PDF sets of Ref. 5(with non-zero [S − ]) compared to the value with the
CTEQ6M set ([S − ] = 0). A positive (negative) δR−
corresponds to an increase (decrease) of the extracted
sin2 θW along Eq. (1).
fit

 −
S × 100

χ2dimuonχ2inclusiveI

δR−

0.540
0.312
0.160
0.103
−0.177

1.30
1.02
1.00
1.01
1.26

0.98
0.97
1.00
1.03
1.09

−0.0065−0.0037−0.0019−0.00120.0023

+

B
A
B
C
B−

sin2 θW . For fits with higher [S − ], such as “A”, it ispossible to reduce the discrepancy to within 1σ.
More input on [s(x)−s̄(x)] would, of course, be helpful in pinning down the contribution of the strangenessasymmetry to δR− . Measurements of associated production of charmed jets and W ± -bosons at the Tevatron, at RHIC or at the future LHC would increase
our knowledge of s(x) and s̄(x). In principle it seems
also feasible to study [s(x) − s̄(x)] on the lattice. Unfortunately, the most relevant moment [S − ] does notcorrespond to a local operator and cannot be calculated on the lattice.
The uncertainties in the QCD theory which relates
R− to sin2 θW are a comparatively large and unfortunate mismatch with the high statistical precision of the
NuTeV data.1) Within the uncertainty bounds, the results of this study suggest that the new dimuon data,
the Weinberg angle measurement, and other global
data sets used in QCD parton structure analysis can
all be consistent within the standard model of particle
physics.
References
1) NuTeV Collaboration, G. P. Zeller et al.: Phys. Rev.
Lett. 88, 091802 (2002).
2) S. Davidson, S. Forte, P. Gambino, N. Rius, and A.
Strumia: JHEP 0202, 037 (2002).
3) E. A. Paschos and L. Wolfenstein: Phys. Rev. D 7, 91(1973).
4) S. Kretzer and M. H. Reno: Phys. Rev. D 69, 034002(2004).
5) F. Olness et al.: RBRC-329.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Energy loss of leading parton in hot QGP†
S. Jeon∗In highly relativistic heavy ion collisions, productionof hard pT partons precedes most other processes, simply because the time scale of the production is short,τ ∼ 1/pT . In particular, the production of hard secondary partons precedes the formation of a quarkgluon plasma (QGP). Therefore, the produced hardpartons ﬁnd themselves in an environment far diﬀerent
from a vacuum. The interaction between the partonand the environment inﬂuences the ﬁnal spectrum ofhigh pT hadrons in a nontrivial manner. In particular,
if the QGP is very dense, we expect energy loss, leading to an energy dependent suppression of the high pT
spectrum, a phenomenon called “jet quenching.” Theextent of jet quenching can be used to learn about the
QGP. Experimentally, the CERN SPS exhibited little
evidence of jet quenching, but RHIC has revealed arather dramatic suppression of high pT pions.
Theoretically, it is well established that the mainenergy loss mechanism of a fast parton is thebremsstrahlung of gluons in the medium. The strengthof the bremsstrahlung in medium depends on a coherence eﬀect called the Landau-Pomeranchuk-Migdal(LPM) eﬀect.1–9)
The purpose of this paper is to revisit the energy loss
calculation with particular emphasis on two points. (i)Bremsstrahlung energy loss is dominated by hard emissions. Therefore, the distribution of ﬁnal energies is as
broad as the mean energy loss. To account for this, we
directly evolve the spectrum of the partons as they
undergo bremsstrahlung energy loss using a kinetic
equation. (ii) At realistic parton energies one cannot
take the LPM eﬀect to be parametrically large. Therefore, we will use the formalism developed by Arnold,
Moore and Yaﬀe (AMY),10) which correctly treats the
LPM eﬀect (up to O(gs ) corrections) at all energies
Egluon > gs T .
In Fig. 1, we show the ratio of the ﬁnal and the initial quark spectrum calculated in two ways. The solidand dashed curves are the result of directly solving thefull equation, and the dotted and dash-dot curves wereobtained by evolving particle energies according to adE/dx approximation. With the plasma temperatureof about 0.4 GeV, the energy range shown corresponds
to about 6 GeV to 20 GeV, with a time range of 0.5 fm
to 1.5 fm.
In this way, we have demonstrated that the LPMsuppressed bremsstrahlung can in fact explain thequalitative features of the high pT experimental dataobtained from RHIC. This is in contrast to previ†∗

Fig. 1. The ratios of the ﬁnal and the initial momentum
spectra for quarks. The black and red (solid) curves arecalculated by solving the full equation. The blue andgreen (dashed) curves are calculated by ﬁrst calculating
dE/dt.

ous ﬁndings. This diﬀerence is due to two features of
our treatment. First, we determine the distribution of
the ﬁnal energies that an energetic parton can end up
with, rather than using the mean. This is importantwhen the initial spectrum is steeply falling. Second,
we do not assume that the LPM eﬀect is parametrically large from the beginning, but use a treatment
which correctly handles the transition between BetheHeitler and LPM regimes. Since this transition occurs
at emitted gluon energies of ∼10 T , such a treatment
is necessary. We ﬁnd that the ratio R of the data to
the pp-based expectations initially decreases with energy, reaches a minimum at around 30 T , and then rises
slowly thereafter.
References
1) M. Gyulassy and X. Wang: Nucl. Phys. B 420, 583(1994).
2) R. Baier et al.: Nucl. Phys. B 483, 291 (1997).
3) R. Baier et al.: Nucl. Phys. B 531, 403 (1998).
4) B. G. Zakharov: JETP Lett. 63, 952 (1996).
5) M. Gyulassy, P. Levai, and I. Vitev: Nucl. Phys. B
594, 371 (2001); Phys. Rev. Lett. 85, 5535 (2000);
Phys. Lett. B 538, 282 (2002).
6) I. Vitev and M. Gyulassy: Phys. Rev. Lett. 89, 252301(2002).
7) R. Baier et al.: JHEP 0109, 033 (2001).
8) E. Wang and X. N. Wang: Phys. Rev. C 64, 034901(2001).
9) S. Jeon, J. Jalilian-Marian, and I. Sarcevic: Nucl.
Phys. A 723, 467 (2003).
10) P. Arnold, G. D. Moore, and L. G. Yaﬀe: JHEP 0111,
057 (2001); JHEP 0206, 030 (2002); JHEP 0301, 030(2003).

Condensed from the article in hep-ph/0309332. Work donewith Guy Moore in McGill University. Submitted to Phys.
Rev. Lett.
Physics Department, McGill University, Canada

201

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RIKEN Accel. Prog. Rep. 37 (2004)

Power counting in the high density eﬀective theory†
T. Schäfer∗
The study of hadronic matter in the regime of highbaryon density has led to the theoretical predictionof several new phases of strongly interacting matter,such as color superconducting quark matter and colorﬂavor locked matter. These phases may be realized innature in the cores of neutron stars. In order to study
this possibility quantitatively we would like to develop
a systematic framework that will allow us to determine
the exact nature of the phase diagram as a function of
the density, temperature, the quark masses, and thelepton chemical potentials, and to compute the low
energy properties of these phases.
Such a framework is provided by eﬀective ﬁeld theory. At high baryon density the relevant degrees of
freedom are particle and hole excitations which movewith the Fermi velocity v. Since the momentum p ∼ vµ
is large, typical soft scatterings cannot change the momentum by very much. An eﬀective ﬁeld theory ofparticles and holes in QCD1) is given by1L=ψv+ (iv · D)ψv − Gaµν Gaµν + . . . ,(1)4v
where vµ = (1, v). The ﬁeld describes particles andholes with momenta p = µv + l, where l  µ. We will
write l = l0 +l +l⊥ with l = v(l· v) and l⊥ = l− l . In
order to take into account the entire Fermi surface wehave to cover the Fermi surface with patches labeled by
the local Fermi velocity. The number of such patches
is nv ∼ (µ2 /Λ2⊥ ) where Λ⊥  µ is the cutoﬀ on thetransverse momenta l⊥ .
Higher order corrections have additional derivatives, or more powers of the ﬁelds. At O(1/µ)
2
ψv and ψv+ σ µν G⊥
we encounter terms like ψv+ D⊥µν ψv .
2
At O(1/µ ) we ﬁnd four fermion operators like(ψv1 Γψv2 )(ψv+3 Γ ψv+4 )δ( i vi ). Four fermion operators
describe large angle scatterings that are not accounted
for by the leading order, collinear, interaction given in
Eq. (1).
In the following we wish to discuss the power counting associated with the high density eﬀective theory.2,3)
We will count powers of the small momentum l. Complications arise because not all loop diagrams scale asl4 . In fermion loops sums over patches and integrals
over transverse momenta can combine to give integralsthat are proportional to the surface area of the Fermi
sphere,
 2

1 
µ2
d l⊥
dΩ
.
(2)
=
2π
(2π)2
2π 2
4π

v

†
∗

202

Condensed from the article in Nucl. Phys. A 728, 251 (2003)
North Carolina State University, USA

These loop integrals scale as l2 , not l4 . In the following
we will refer to loops that scale as l2 as “hard loops”
and loops that scale as l4 as “soft loops”. In order totake this distinction into account we deﬁne VkS and VkH
to be the number of soft and hard vertices of scaling
dimension k. A vertex is called soft if it contains nofermion lines. In order to determine the l counting ofa general diagram in the eﬀective theory we remove all
gluon lines from the graph. We denote the number ofconnected pieces of the remaining graph by NC . Using
Euler identities for both the initial and the reduced
graph we ﬁnd that the diagram scales as lδ with(k − 4)VkS + (k − 2 − fk )VkHδ=i

+ EQ + 4 − 2NC .

(3)Here, fk denotes the number of fermion ﬁelds in a hardvertex, and EQ is the number of external quark lines.
We observe that in general the scaling dimension δ
increases with the number of higher order vertices, butthere are two important exceptions.
First we observe that the number of disconnected
fermion loops, NC , reduces the power δ. Each disconnected loop contains at least one power of the coupling
constant, g, for every soft vertex. As a result, fermion
loop insertions in gluon n-point functions spoil thepower counting if the gluon momenta satisfy l ∼ gµ.
This implies that for l < gµ the high density eﬀective
theory becomes non-perturbative and fermion loops ingluon n-point functions have to be resummed. This is
the familiar hard dense loop (HDL) resummation.4)
The second observation is that the power counting
for hard vertices is modiﬁed by a factor that counts thenumber of fermion lines in the vertex. Using Eq. (3)it is easy to see that four-fermion operators without
extra derivatives are leading order (k − 2 − fk = 0),
but terms with more than four fermion ﬁelds, or extra
derivatives, are suppressed. This result is familiar fromthe eﬀective ﬁeld theory analysis of theories with shortrange interactions.5)
References
1) D. K. Hong: Phys. Lett. B 473, 118 (2000).
2) T. Schäfer: Nucl. Phys. A 728, 251 (2003).
3) T. Schäfer: Proc. 2nd Int. Workshop on Quantum Chromodynamics: Theory and Experiment, Conversano,
Italy, 2003-6 (2003), eConf C030614:038.
4) E. Braaten and R. D. Pisarski: Phys. Rev. D 45, 1827
(1992).
5) R. Shankar: Rev. Mod. Phys. 66, 129 (1994).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Interplay between soft and hard hadronic components for
identified hadrons at RHIC
T. Hirano and Y. Nara∗
A vast body of data has already been collected andanalyzed during the past few years at the Relativistic
Heavy Ion Collider (RHIC) in Brookhaven National
Laboratory for the complete understanding of dense
QCD matter.1) In the collider experiments, perturbative QCD (pQCD) processes become important inintermediate-high pT regions. One of the most important new physics in heavy ion collisions at RHIC
energies is to study the propagation of (mini-)jets
in dense QCD matter. Jet quenching has been proposed2) as a possible signal of deconﬁned nuclear matter, the quark gluon plasma (QGP). Recent data at
RHIC indicate that yields for both neutral pions3,4)
and charged hadrons5–7) at high pT in central Au + Au
collisions are suppressed relative to the pp scaled by the
number of binary collisions or large centrality spectra.
However, protons do not seem to be quenched in themoderate pT range.8)
We investigate the transverse dynamics in Au + Au√
collisions at sN N = 200 GeV by emphasizing upon
the interplay between soft and hard hadronic components through pT spectra for identiﬁed hadrons.
From hydrodynamics combined with traversing minijets which go through jet quenching in the hot medium,
we calculate the interactions of hard jets with the softhydrodynamic components (the hydro+jet model).9)
We obtain the pT spectra for pions, kaons, and protons from hydrodynamic and minijet contributions.
Both soft (hydro) and hard (minijets) components arefound to be important for the hadron spectra in thetransverse momentum of the range around 2  pT 
5 GeV/c, depending on the hadron mass. We can deﬁne the crossing point of transverse momentum pT,crossat which the yield from the soft part is identical to thatfrom the hard part. pT,cross increases with the mass ofparticles because of the eﬀect of radial ﬂow. In central
collisions, we ﬁnd pT,cross ∼ 1.8, 2.7, and 3.7 GeV/c
for pions, kaons, and protons, respectively. Figure 1
shows the nuclear modiﬁcation factors
dN A+AdN p+p
RAA =
Ncoll
,
(1)
dpT dydpT dyfor pions, kaons, and protons, respectively, in Au + Au
collisions at RHIC for impact parameters b = 2.0, 5.5,
and 7.2 fm. We ﬁnd that protons are not suppressed(RAA ∼ 1) in the momentum range of 1.5 < pT <2.5 GeV/c. Pions, on the contrary, are largely suppressed for all momentum range. Since the crossing
point pT,cross depends on the hadronic species, RAA
only for pions reﬂects the jet quenching eﬀect in this∗Fig. 1. The nuclear modification factors RAA for π − (shortdashed), K − (long dashed), and p (solid). RAA for
charged hadrons is also shown in dotted lines. Data are
obtained by the PHENIX Collaboration.4)

momentum region. pT,cross ∼ 3.7 GeV/c for protons
leads to RAA ∼ 1 due to the soft component which
is pushed from the low to high pT regions by radial
ﬂow. This does not mean the absence of jet quenchingfor protons. The interplay between radial ﬂow and jet
quenching can give an interpretation of recent puzzling
data for proton nuclear modiﬁcation factors.
References
1) Proc. 16th Int. Conf. on Ultrarelativistic NucleusNucleus Collisions, Quark Matter 2002: Nucl. Phys. A
715 (2003).
2) M. Gyulassy and M. Plümer: Phys. Lett. B 243, 432(1990); X.-N. Wang and M. Gyulassy: Phys. Rev. Lett.
68, 1480 (1992); M. Gyulassy and X.-N. Wang: Nucl.
Phys. B 420, 583 (1994); X.-N. Wang, M. Gyulassy,
and M. Plümer: Phys. Rev. D 51, 3436 (1995).
3) PHENIX Collaboration, K. Adcox et al.: Phys. Rev.
Lett. 88, 022301 (2002).
4) PHENIX Collaboration, S. S. Adler et al.: Phys. Rev.
Lett. 91, 072301 (2003).
5) STAR Collaboration, C. Adler et al.: Phys. Rev. Lett.
89, 202301 (2002).
6) STAR Collaboration, J. Adams et al.: nucl-ex/0305015.
7) PHENIX Collaboration, K. Adcox et al.: Phys. Lett. B
561, 82 (2003).
8) PHENIX Collaboration, S. S. Adler et al.: nucl-ex/
0305036.
9) T. Hirano and Y. Nara: Phys. Rev. C 66, 041901(R)(2002); Phys. Rev. Lett. 91, 082301 (2003).

Department of Physics, University of Arizona, USA

203

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RIKEN Accel. Prog. Rep. 37 (2004)

Hadronization at RHIC: Recombination vs. fragmentation?†
S. A. Bass,∗1 R. J. Fries,∗2 B. Müller,∗1 and C. Nonaka∗1
Data from the Relativistic Heavy Ion Collider(RHIC) have shown a strong nuclear suppression of thepion yield at transverse momenta larger than 2 GeV/c
in central Au+Au collisions, compared with p+p interactions.1,2) The emission of protons and antiprotons
does not appear to be similarly suppressed, and thep/π + ratio reaches or even exceeds unity for transverse
momenta above 2 GeV/c. These results lack a consistent explanation in the standard picture of hadronproduction at high transverse momentum, which assumes that hadrons are created by the fragmentationof energetic partons. Whereas the observed suppression of the pion yield is attributed to the energy loss ofpartons during their propagation through the hot anddense matter created in the nuclear collision — a phenomenon commonly referred to as jet quenching3) —the absence of a similar eﬀect in the proton spectrum
is puzzling.4)
In Ref. 5 we have shown that hadron production
at momenta of a few GeV/c in an environment witha high density of partons occurs by recombination,rather than fragmentation, of partons. Recombination
always dominates over fragmentation for an exponentially falling parton spectrum, but fragmentation winsout eventually, when the spectrum takes the form of
a power law.
Starting point of our calculation is the assumptionthat the constituent quark transverse momentum distribution at hadronization is given by the superposition of a thermal distribution for low and intermediate
momenta and a pQCD based power-law contribution
for large transverse momenta.
The normalization of the thermal part of the spectrum is adjusted to ﬁt the measured inclusive spectrumof charged hadrons from PHENIX, as shown in theupper frame of Fig. 1. The parameters of the pQCD
contribution are ﬁxed by a minijet calculation.5)
The lower frame of Fig. 1 shows our prediction forthe p/π + ratio. The rapid drop of its value in the range
4–5 GeV/c is an unambiguous prediction of our model,
due to the onset of parton fragmentation. Experiments
at RHIC have not yet been able to probe this PT range,
because the identiﬁcation of protons has not been feasible beyond 4 GeV/c. The identiﬁcation of hyperons
is possible to higher PT , and indications of a rapid dropin the Λ/Ks0 ratio have been found.2)
We ﬁnd that the competition between recombination and fragmentation of partons can explain several
†
∗1
∗2

204

Condensed from the article in Phys. Rev. Lett. 90, 202303(2003)
Department of Physics, Duke University, USA
Department of Physics, University of Minnesota, USA

Fig. 1. Top: inclusive PT spectrum of charged hadrons in√central Au + Au collisions at sN N = 200 GeV. Bottom: ratio of protons to π + as a function of PT .

of the surprising features of the published data. In particular, the proton excess at intermediate PT , the different nuclear suppression observed in pion and proton
spectra, and the diﬀerent saturation thresholds in theelliptic ﬂow, are easily explained. We predict that all
baryon spectra will exhibit a rapid transition around
5 GeV/c to a region dominated by parton fragmentation. Finally, our scenario requires the assumption ofa thermalized partonic phase characterized by an exponential momentum spectrum. Such a phase may beappropriately called a quark-gluon plasma.
References
1) PHENIX Collaboration, K. Adcox et al.: Phys. Rev.
Lett. 88, 022301 (2002); Phys. Rev. Lett. 88, 242301(2002); Phys. Rev. Lett. 89, 092302 (2002).
2) STAR Collaboration, C. Adler et al.: Phys. Rev. Lett.
86, 4778 (2001); Phys. Rev. Lett. 89, 092301 (2002);
nucl-ex/0210033.
3) M. Gyulassy and X. Wang: Nucl. Phys. B 420, 583(1994); R. Baier et al.: Nucl. Phys. B 484, 265 (1997).
4) PHENIX Collaboration, J. Velkovska: J. Phys. G 30, S
151 (2004).
5) R. J. Fries, B. Muller, C. Nonaka, and S. A. Bass: Phys.
Rev. Lett. 90, 202303 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

New signature of the QCD critical point
Y. Hatta∗1 and M. A. Stephanov∗2
Recently, there has been considerable interest, boththeoretically and experimentally, in the critical pointconsidered to exist in the phase diagram of QCD at
ﬁnite temperature and baryon chemical potential. The
ﬁrst proposal of observables for discovering the criticalpoint in experiments is given in Ref. 1. It was predictedthat enormous ﬂuctuations of the sigma meson ﬁeld
associated with the second order phase transition could
be reﬂected in the event-by-event ﬂuctuation of pion
observables through the pion-sigma coupling.
Here we propose a new observable2) for discovering
the critical point; the event-by-event ﬂuctuation of the
net proton number, i.e., the number of protons minus the number of antiprotons observed. Our starting
point is the fact that the baryon number susceptibility1 (δB)2 ,(1)
χB =VT
where V and T are the volume and the temperature,
respectively, and δB is the baryon number measured
relative to the equilibrium value, diverges at the critical point. If we could measure all the baryons in the experiments, the event-by-event ﬂuctuation of the baryon
number would be a signature of the end-point. Unfortunately, it is very diﬃcult to detect the neutrons inultrarelativistic heavy-ion collision experiments, whichmakes the measurement of the baryon number ﬂuctuation virtually impossible. However, we argue that due
to the peculiar nature of the critical point, the proton
number ﬂuctuation alone correctly reﬂects the divergence of χB .
A simple symmetry argument shows that, in thepresence of isospin symmetry, the isospin number susceptibility1 (δI)2 ,
(2)
χI =VT
is ﬁnite at the critical point. One can also show thatthe electric charge susceptibility is divergent and theratio of the singular parts of the susceptibilities isχB : χI : χQ = 4 : 0 : 1.

(3)

We wish to relate the susceptibilities χB , χI and χQ
to the observable particle number ﬂuctuations. For
simplicity, we shall limit our discussion by considering
only protons, neutrons and pions. In hadron language,
the susceptibilities may be written as

1 
2
χB =
(δNp−p̄ + δNn−n̄ ) ,
VT

2 
1
1
1
δNp−p̄ − δNn−n̄ + δNπ+ −π−
,
χI =
VT
2
2
∗1
∗2

χQ =


1 
(δNp−p̄ + δNπ+ −π− )2 ,VT

(4)where we introduced the notation Np−p̄ ≡ Np − Np̄ forthe net proton number ﬂuctuation. Similar notations
are used for neutrons and pions.
Observing that the singularity in the susceptibilities
is caused by the exchange of the sigma meson which is
an isospin singlet, one can single out the net contribution to the singular part:4
δNp−p̄ δNp−p̄  ,VT
χI = 0,1
δNp−p̄ δNp−p̄  .
χQ =
VT
χB =

(5)

Namely, the singular part of the charge ﬂuctuation
comes from the protons. The pions do not contributeto the singular part because of a cancellation. We see
also that the proton number ﬂuctuation completely reﬂects the singularity of the baryon number susceptibility, which justiﬁes its use as a sensible probe for the
QCD critical point.
A simple estimate of the net proton number ﬂuctuation is given by calculating the correlatorδnp δnk ,(6)where np is the net proton number in the momentum
bin labeled by the value p. The main feature of suchcalculations2) is that the singularity coming from theexchange of the sigma meson is enhanced by the proton loop eﬀect. Thus, if the critical density of theend-point is large, as suggested by several model calculations and lattice simulations, our eﬀect could bevery large. Experimentally, separating protons andmeasuring proton ﬂuctuations is a feasible task in the
RHIC as well as in the SPS detectors. A direct measurement of√the proton number ﬂuctuation as a function of the s of the collision is both feasible and isless aﬀected by other eﬀects. The correlation of sucha measurement with other proposed signatures (suchas pt ﬂuctuations1) ) would lead to the discovery of the
QCD critical point.
References
1) M. A. Stephanov, K. Rajagopal, and E. V. Shuryak:
Phys. Rev. Lett. 81, 4816 (1998).
2) Y. Hatta and M. A. Stephanov: Phys. Rev. Lett. 91,
102003 (2003).

Department of Physics, Kyoto University
Department of Physics, University of Illinois, USA

205

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RIKEN Accel. Prog. Rep. 37 (2004)

Pseudogap of color superconductivity†
M. Kitazawa,∗1 T. Koide,∗2 T. Kunihiro,∗3 and Y. Nemoto
Recently considerable attention has been being paid
to color superconductivity (CS) at large chemical potential (µ) but with relatively low temperature (T ) of
QCD. At relatively low density, the strong coupling
nature of QCD may make the so-called Ginzburg region so wide that precursory ﬂuctuations of a pairﬁeld may give rise to physically signiﬁcant eﬀects even
above the critical temperature (Tc ).1) The existenceof the large ﬂuctuations suggests that CS may sharesome basic properties with high-Tc superconductivity (HTSC). One of the characteristic phenomena of
HTSC is the existence of a pseudogap, i.e., the anomalous depression of the density of states (DOS) as afunction of fermion energy ω around a Fermi surface
above Tc . We show that the pseudogap of the quark
density of states is actually formed in hot quark matter as a precursory phenomenon of CS based on alow-energy eﬀective theory, the Nambu-Jona-Lasinio(NJL) model.
DOS is calculated from the spectral function of asingle quark. A ﬂuctuating diquark pair ﬁeld develops a collective mode at T above but in the vicinity of
Tc .1) Our point in this work is that the soft mode contributes to the self-energy of the quark ﬁeld, thereby
it can markedly modify the spectral function and DOS
resulting a pseudogap.
A numerical calculation of the self-energy of a quark
Σ− shows that as momentum k varies from kF , thepeak of |ImΣ− | at ω ≈ 0 moves along ω ≈ −k + µ.
This indicates that quasiparticles with this energy are
dumped modes. ImΣ− describes a decay process of aquark to a hole and a diquark, q → h + (qq), where
the hole is on-shell with free dispersion relation ωh =µ−|kh |. The essential point for pseudogap formation isthat the above process is enhanced when the diquark(qq) forms a collective mode; the diquark soft mode(qq)soft has a prominent strength at negligible energy
ωs and momentum ks near Tc . Owing to the energymomentum conservation, the energy momentum of the
decaying particle (ωp , kp ) should satisfy ωp + ωh =
ωs  0 and kp + kh = ks  0. This indicates thatwhen the decaying particle has almost the same energy
as a free quark, |ImΣ− (k, ω)| is largest.
The spectral function is shown in Fig. 1. One cansee two families of peaks around ω = ω− (k) ≈ k − µand ω = −k − µ, which correspond to the quasiparticle
peaks of the quarks and anti-quarks, respectively. A
notable point is that the quasiparticle peak has a clear
†
∗1
∗2
∗3

206

Condensed from the article in arXiv:hep-ph/0309026
Department of Physics, Kyoto University
Institut für Theoretische Physik, J. W. Goethe-Universität,Germany
Yukawa Institute for Theoretical Physics, Kyoto University

Fig. 1. Spectral function at µ = 400 MeV and ε = 0.01.

depression around ω = 0, i.e., the Fermi energy. The
mechanism of the depression is easily understood interms of the characteristic properties of the self-energy
mentioned above.
Figure 2 shows DOS at µ = 400 MeV and various reduced temperatures ε = (T − Tc )/Tc . As anticipated,
one can see a signiﬁcant depression of DOS, i.e., thepseudogap, around Fermi energy ω = 0. One sees thatthe smaller ε, the more signiﬁcant the rate of depression. The clear pseudogap structure survives even atε = 0.05. One may thus conclude that there is a pseudogap region within the QGP phase above Tc up to
T = (1.05 ∼ 1.1)Tc at µ = 400 MeV, for instance.
Our result obtained for a three-dimensional systemtells us that a considerable pseudogap can be formed
without the help of the low dimensionality as in HTSC
and that pseudogap phenomena in general may be universal in any strong coupling superconductivity.

Fig. 2. Density of states at µ = 400 MeV and various εvalues. The dotted line shows these of free quarks.

References
1) M. Kitazawa, T. Koide, T. Kunihiro, and Y. Nemoto:Phys. Rev. D 65, 091504(R) (2002).

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RIKEN Accel. Prog. Rep. 37 (2004)

Color ferromagnetic phase at finite quark density
M. Ohtani, A. Iwazaki,∗1 O. Morimatsu,∗2 and T. Nishikawa∗2
A phase diagram of quark and hadronic matter isconsidered to have a rich structure for ﬁnite temperature and density. The restoration of chiral symmetry
and deconﬁnement transition have drawn much attention for understanding systems with strong interaction.
Color superconductors are a topic of great interest andare expected to be realized for high-density and lowtemperature regions. However, using only indirect information by astronomical observations, we must speculate on color superconductors which may exist in compact stars. In heavy ion collisions, it is diﬃcult tocreate suﬃciently dense quark matter to conﬁrm its
signals. Accordingly, phases and their properties ofquark/hadrons for ﬁnite density are still open to discussion, though the deeply bound kaonic nucleus ispromising for studying high-density matter.1) In viewof the situation, we report here the realizability ofa new phase — color ferromagnetic phase — in colddense quark matter.
In non-Abelian gauge theory, a perturbative vacuum
is known to be unstable against condensation of a color
magnetic ﬁeld.2) In fact, the one-loop eﬀective potential implies spontaneous generation of the color magnetic ﬁeld. The color magnetic ﬁeld can be set to be in
the maximal Abelian subalgebra by a gauge transformation and oﬀ-diagonal components of a gluon can betreated as charged matter with spin 1. Then, the energy of the transverse motion of an oﬀ-diagonal gluon
is quantized in Landau levels. However, the energyof the gluonic state in the lowest Landau level has an
imaginary part and hence the system with a spontaneous color magnetic ﬁeld is found to be unstable.3)
Although the physical signiﬁcance of this instability
for the real nonperturbative vacuum is not understoodyet, it has been recently shown4,5) that the color ferromagnetic state becomes stable by forming a speciﬁc
conﬁguration of oﬀ-diagonal gluons in quark matter.
Here we note that this state is analogous to thequantum Hall state (QHS) of electrons because bothof them are accompanied by the magnetic ﬁeld and areeﬀectively reduced to a two-dimensional system. The
dimensional reduction of the color ferromagnetic stateis justiﬁed from the fact that the most unstable modeis spatially uniform along the color magnetic ﬁeld andonly this mode is relevant for the stability of the state.
Therefore, to analyze the color ferromagnetic state, we
adopt Chern-Simons theory which is used to study thequantum Hall system of electrons.6)
In the Chern-Simons theory, an elementary particle
is expressed by composite ﬁelds: a bosonized matter∗1∗2

Department of Physics, Nishogakusha University
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)ﬁeld and the Chern-Simons ﬁeld. The Chern-Simons
ﬁeld is introduced to carry a property of the particle
statistics: the exchange phase of particle permutationis reproduced by the Chern-Simons ﬂux. In our case,oﬀ-diagonal gluons are expressed by composite ﬁelds.
In the case of QHS of electrons, Chern-Simons ﬂux
cancels out the imposed magnetic ﬁeld, so that total
ﬂux on the bosonized electron vanishes. In the sameway, we can consider “the quantum Hall state of oﬀdiagonal gluons”, where the Chern-Simons ﬂux is set
to be equal to the color magnetic ﬁeld. We showedthat the color ferromagnetic state along with the QHS
of oﬀ-diagonal gluons is stable in cold dense quark matter. We predict that this new phase lies between the
hadronic phase and color superconducting phase forlow-temperature regions.
Furthermore, we consider a vortex excitation on the
QHS associated with the color ferromagnetic phase.7)
For the electron system, quasi-particles with fractionalcharge are excited on the QHS8) and they are describedas vortex excitations in the Chern-Simons formalism.
The excitation energy is correlated with the plateau
width of Hall resistance and the stability of the state.
Similarly, the vortex excitation in the QHS of gluons plays an important role in the color ferromagnetic
phase. We solve the equations for a vortex conﬁguration under the color magnetic ﬁeld and estimate the excitation energy of the vortex. We ﬁnd that the vortex
energy decreases as quark density is diminished. This
indicates that the color ferromagnetic state transforms
to the hadronic phase with vortex excitations for lower
density.
In summary, we emphasize the possibility of a newphase, the color ferromagnetic state along with QHS of
the oﬀ-diagonal gluon for a high-density region, which
will give a new clue for understanding the propertiesof dense quark matter.
References
1) Y. Akaishi, A. Doté, and T. Yamazaki: Prog. Theor.
Phys. Suppl. No. 149, 221 (2003); M. Iwasaki et al.:nucl-ex/0310018.
2) G. K. Savvidy: Phys. Lett. B 71, 133 (1977).
3) N. K. Nielsen and P. Olesen: Nucl. Phys. B 144, 376(1978); Phys. Lett. B 79, 304 (1978).
4) A. Iwazaki, O. Morimatsu, T. Nishikawa, and M.
Ohtani: Phys. Lett. B 579, 347 (2004).
5) A. Iwazaki and O. Morimatsu: Phys. Lett. B 571, 61(2003).
6) S. C. Zhang, T. H. Hansson, and S. Kivelson: Phys.
Rev. Lett. 62, 82 (1989).
7) A. Iwazaki, O. Morimatsu, T. Nishikawa, and M.
Ohtani: in preparation.
8) R. B. Laughlin: Phys. Rev. Lett. 50, 1395 (1983).

207

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RIKEN Accel. Prog. Rep. 37 (2004)

Kinetic equation for φ4 theory with generalized
Kadanoﬀ-Baym ansatz
T. Ikeda
Recently, quantum ﬁeld theories in and out of thermal equilibrium have been extensively studied, motivated by heavy-ion collision experiments ongoing at
RHIC and upcoming at LHC, (p)reheating in early
universe and so on. We investigate the decay of a single particle excitation of φ4 theory whose Lagrangianis (∂µ φ)2/2 − g 2 φ4 , in 3 + 1 dimensions and the spatially homogeneous case, using kinetic equations withand without memory eﬀects.
Nonequilibrium properties are often studied on thebasis of Boltzmann-like equations. Those equations,however, are not applicable to strongly correlated plasmas. Kadanoﬀ-Baym (KB) equations for two-point
Green’s functions are useful for studying correlated
plasmas, which are usually diﬃcult to solve directly
due to two-time correlation. Therefore, it is easier
to analyze kinetic equations for Wigner distributionfunction N which is derived from KB equations in theequal time limit. When deriving kinetic equations,
we encounter the reconstruction problem: How can
two-point Green’s functions be expressed as a functionof N ? While the simplest solution is the KadanoﬀBaym (KB) ansatz which cannot explain memory effects, we have a more general solution, the generalized
Kadanoﬀ-Baym (GKB) ansatz which can take into account such eﬀects properly.1) Memory eﬀects are expected to play an important role in correlated systems.
Within the 3-loop level for the two-particle irreducible (2PI) eﬀective action, we obtain two diﬀerent
self-energies.2) The leading order one contributes tothe thermal mass which is obtained by solving the gap
equation self-consistently. Self-energies in the nextto-leading order (NLO) correspond to the scattering
processes, leading to damping of a single particle excitation.
With the above self-energies and the quasiparticle
approximation for the spectral function, we obtained
kinetic equations in time representation:∂t δN (p, t) = −2γ(p, t)δN (p, t),

Figure 1 shows the numerical results of δN as a function of time. For weak coupling g = 0.1, dampings ofexcitation in KB and GKB ansatz are in good agreement, and are both exponential. In this case, there isno memory eﬀect due to the separation of scales: therelaxation time is much larger than the time scale atwhich oscillation of γ(t) ends. For moderately large
coupling g = 1.0, memory eﬀects make the relaxation
time faster, as shown in the middle panel. For thestrongest coupling g = 1.6 in our calculation, δN oscillates around zero and an amplitude of the oscillation
damps slower than the case without memory eﬀects.3)
Thus, memory eﬀects inﬂuence the decay of the excitation diﬀerently as the coupling strength changes.

(1)

for the KB ansatz and∂t δN (p, t) = −2γ(p, t)δN (p, 0) t
dz0 γ(p, z0 − t) ∂z0 δN (p, z0 ), (2)−2Fig. 1. Deviations from thermal distribution for p = 0 with
KB and generalized KB ansatz are plotted as a functionof time for three values of coupling constant.

0

for the GKB ansatz.3) Here, δN is a deviation fromthe thermal distribution function, and γ(p, t) is a timedependent damping rate which can be calculated using
the gap of NLO self-energies.

208

References
1) P. Lipavsky, V. Spicka, and B. Velicky: Phys. Rev. B
34, 6933 (1986).
2) J. Berges and J. Cox: Phys. Lett. B 517, 369 (2001).
3) T. Ikeda: hep-ph/0401045 (accepted for publication in
Phys. Rev. D).

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RIKEN Accel. Prog. Rep. 37 (2004)

Charge symmetry breaking in few-nucleon systems†
U. van Kolck∗
Two-ﬂavor QCD is nearly invariant under the SU(2)group of isospin transformations. Charge symmetry isa rotation of π around the y axis in isospin space, whichis broken by the diﬀerence in up-down quark masses
and by electromagnetic eﬀects.
These sources of CSB manifest themselves in various guises in the low-energy eﬀective theory of QCD.
One of the most important consequences is the protonneutron mass splitting ∆mN = mp − mn = −1.3 MeV,
which receives contributions from both quark-mass difference —denoted δmN — and electromagnetism —denoted δ̄mN . Although there are several estimates ofthese two contributions, there is no ﬁrm experimental
information on their sizes: at least one other suitable
CSB observable is needed to separate them.
One can show1) that the approximate chiral symmetry of QCD implies that there are two sets of pionnucleon interactions with strengths ﬁxed by δmN andδ̄mN , respectively. In Ref. 2 it was suggested thatthese interactions would give important contributions
to the front-back asymmetry in the reaction pn → dπ 0near threshold. Assuming δ̄mN > 0 as in most models,
it was predicted that these contributions would be 1–2
times larger, but in the opposite direction, than thesum of other, more conventional mechanisms. This†∗prediction has recently been conﬁrmed at TRIUMF.3)
An estimate of the contributions from these interactions to the CSB reaction dd → απ 0 near threshold suggested that it could be observed at IUCF. Indeed, for the ﬁrst time an unambiguous signal was seen
above background, resulting in a cross-section of about
10 pb.4) A group of theorists including the present author is now working on a more accurate calculation.5)
Given their importance in pion production, it is natural to investigate the eﬀect of these interactions in
nuclear forces. The corresponding two-pion exchange
two-nucleon potential is the dominant non-short-range
CSB interaction, and it has been calculated in Ref. 6.
Its eﬀects on CSB observables are small.
References
1) U. van Kolck: Few-Body Systems Suppl. 9, 444 (1995).
2) U. van Kolck, J. A. Niskanen, and G. A. Miller: Phys.
Lett. B 493, 65 (2000).
3) A. K. Opper et al.: Rhys. Rev. Lett. 91, 212302 (2003).
4) E. J. Stephenson et al.: Phys. Rev. Lett. 91, 142302(2003).
5) A. Gårdestig et al.: to appear in Phys. Rev. C, nuclth/0402021.
6) J. L. Friar, U. van Kolck, G. L. Payne, and S. A. Coon:
Phys. Rev. C 68, 024003 (2003).

This research was supported in part by the DOE and by the
Alfred P. Sloan Foundation
University of Arizona, USA

209

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RIKEN Accel. Prog. Rep. 37 (2004)

Lattice chiral symmetry with hopping interactions†T. Sugihara
In contrast with the great success of the lattice gauge
theory, lattice fermions remain a long-standing problem. Naive discretization causes the species doublingproblem.1) The situation does not change regardlessof how the lattice spacing is reduced as long as thespace-time derivative is modeled as a naive diﬀerence.
Many attempts have been made to resolve the doubling problem.1–6) Wilson removed doublers at low energy by introducing an interaction that mixes left- andright-handed fermions.1) However, unwanted degeneracy persists at high energy and chiral symmetry is explicitly broken. To ﬁx these problems, Kaplan modiﬁed Wilson’s fermion with an extra dimension4) andsucceeded in realizing approximate chiral symmetry.
However, the cost of numerical calculations based on
it is high. If we can develop a method of performing such calculations without an extra dimension, thecalculation time decreases largely and a deeper understanding of quantum ﬁeld theory becomes possible.
The lattice fermion has another serious problem.
The lattice fermion propagator deviates from the continuum one even if doublers are removed with existing
techniques such as Kaplan’s fermion. We need to modify the discretized propagator somehow so that it will

be as close as possible to the continuum propagator.
In this work, based on a Hamiltonian formalism,
we introduce ultralocal hopping interactions to remove
doublers and improve the momentum dependence offermion energy in the (1 + 1)-dimensional free Diracfermion (see Fig. 1). On the basis of the continuum
theory, we know the correct momentum dependence ofthe energy. We start from momentum space and returnto real space via discrete Fourier transform. Approximate chiral symmetry is realized at low energy (seeFig. 2). Explicit breaking of chiral symmetry has been
compressed to high energy. In future works, it should
be precisely checked whether the insertion of gauge interactions aﬀects chiral properties.

Fig. 2. The matrix elements of γ5 are plotted as functionsof momentum pl modiﬁed with the Lanczos factor. The
functions are plotted on the right-half plane of momentum space pl ≥ 0. The circles are plots of the diagonal(1,1) element of γ5 . The crosses are plots of the negativeoﬀ-diagonal (1,2) element of γ5 . The solid and dashedlines are plotted as visualguides. The Dirac fermion has
approximate chiral symmetry because γ5 almost commutes with the Hamiltonian at low energy.

References
Fig. 1. The solid line plots the correct energy ±p fromthe continuum theory. The dashed line plots the function ±s(p) modiﬁed with the Lanczos factor. The dotdashed line plots the function ±k(p) modiﬁed with the
Lanczos factor. The function ±k(p) almost agrees with±p in the fundamental region |p| ≤ π except for a small
deviation around momentum |p| ∼ 2.3. The dispersion
relation of the continuum theory has been reproduced
approximately.
†

210

Condensed from the article in Phys. Rev. D 68, 034502(2003)

1) K. G. Wilson: in New Phenomena in Subnuclear
Physics, edited by A. Zichichi (Plenum, New York,
1977) p.13.
2) J. Kogut and L. Susskind: Phys. Rev. D 11, 395 (1975).
3) S. D. Drell, M. Weinstein, and S. Yankielowicz: Phys.
Rev. D 14, 487 (1976).
4) D. B. Kaplan: Phys. Lett. B 288, 342 (1992); M. F.
Golterman, K. Jansen, and D. B. Kaplan: Phys. Lett.
B 301, 219 (1993).
5) H. Neuberger: Phys. Lett. B 417, 141 (1998); Phys.
Lett. B 427, 353 (1998).
6) M. Lüscher: Phys. Lett. B 428, 342 (1998).

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RIKEN Accel. Prog. Rep. 37 (2004)

Comparison of matrix model and lattice data for the QCD Dirac
operator at nonzero chemical potential
G. Akemann∗1 and T. Wettig∗2
QCD at nonzero density is important in a variety ofphysical situations, such as relativistic heavy-ion collisions or neutron stars. While considerable progress has
recently been made in several directions, Monte Carlosimulations at real chemical potential µ > 0 are notfeasible at large volumes because the weight function
is complex. To obtain a better theoretical understanding of this situation, we have studied the (complex)
eigenvalues of the QCD Dirac operator in a particularrandom matrix model and on the lattice. The model1)
is deﬁned by the partition functionZν (τ ; {mf })
Nf
 
N

=
dzj dzj∗ |zj |2|ν|+1(zj2 + m2f )
C j=1

×e

and β = 5.0, see Ref. 3 for the justiﬁcation of thesechoices. We eﬀectively have ν = 0 because the staggered Dirac operator does not have exact zero modes
at strong coupling. Some of our results are shown in
Figs. 1 and 2 (the histograms represent lattice data,
the solid curves the analytical predictions). Note thatthe data have been rescaled by a factor proportional tothe average level spacing in the same way as in Eqs. (2)and (3). We observe good agreement between theory
and lattice data in both regimes. This conﬁrms the existence of the two diﬀerent scaling limits and indicatesthat the model of Eq. (1) may be capable of describing
QCD. Recent calculations4) for the model of Ref. 2 atweak nonhermiticity found small numerical diﬀerences
between the two models which deserve further study.

f =1

2
2
∗2
N
τ
− 1−τ
2 [|zj | − 2 (zj +zj )]

N

 2

zk − zl2 2

(1)

k>l

given in terms of N eigenvalues zj . Here, the mf arequark masses, ν is the topological charge, and τ determines the degree of nonhermiticity. We have µ2 =1 − τ 2 by comparing Eq. (1) with the matrix model ofRef. 2. From Eq. (1) analytical results can be derived
for the distribution of the small Dirac eigenvalues. Two
regimes have to be distinguished. In the region of weak
nonhermiticity, we have µ2 N ≡ α2 ∼ O(1) and obtainfor N → ∞ and Nf = 01)√( m ξ)2πα2|ξ| exp −ρweak (ξ) =erf(α)α2 1√√2dt e−α t J|ν| ( tξ)J|ν| ( tξ ∗ ) , (2)×Fig. 1. Density of small Dirac eigenvalues in the regime of
weak nonhermiticity, cut along the real axis (left) andparallel to the imaginary axis (right).

0

where
√ the eigenvalues have been rescaled according toξ = 2N z. In the region of strong nonhermiticity, we
have µ ∼ O(1) and obtain1)
√
  

(3)
ρstrong (ξ) = 2π |ξ| exp −|ξ|2 I|ν| |ξ|2
with rescaled eigenvalues ξ = N/(1−τ 2 ) z.
The conjecture is that the model of Eq. (1) is in thesame universality class as QCD, in which case Eqs. (2)and (3) should agree with lattice data. We have tested
this conjecture by computing large ensembles of spectra for the staggered Dirac operator at several valuesof µ and lattice volume V . We worked at Nf = 0∗1∗2

Service de Physique Théorique, Commissariat de I’Energie
Atomique/Direction des Sciences de la Matiere/Service dePhysique Theorique Saclay, Unité de recherche associée au
Centre National de la Recherche Scientifique, France
Department of Physics, Yale University, USA

Fig. 2. Density of small Dirac eigenvalues in the regimeof strong nonhermiticity, cut along the real (left) andimaginary (right) axes.

References
1) G. Akemann: Phys. Rev. Lett. 89, 072002 (2002); J.
Phys. A 36, 3363 (2003).
2) M. A. Stephanov: Phys. Rev. Lett. 76, 4472 (1996).
3) G. Akemann and T. Wettig: hep-lat/0308003.
4) K. Splittorﬀ and J. J. M. Verbaarschot: hep-th/
0310271.

211

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RIKEN Accel. Prog. Rep. 37 (2004)

Calculations of correlators and spectral function
and properties of QGP
S. Datta,∗1 O. Kaczmarek,∗1 F. Karsch,∗1 P. Petreczky,∗2 K. Petrov,∗2 I. Wetzorke,∗3 and F. Zantow∗1
Properties of heavy quarkonia at ﬁnite temperature
have been a longstanding problem as it was suggested
that they can be used as a signature of Quark Gluon
Plasma (QGP) in heavy ion collisions.1) The propertiesof heavy quarkonia have been studied using potential
models.1,2) Lattice calculation of the charmonia spectral function become available only recently.3–5)
We have calculated charmonia spectral functions inquenched QCD (i.e. without dynamical quarks) in
pseudo-scalar, vector, scalar and axial-vector channels corresponding to ηc , J/ψ, χc0 and χc1 states
respectively.
Spectral function have been calculated from temporal lattice correlation function using
the Maximum Entropy Method (MEM).6) We haveused isotropic lattices with the lattice spacing a−1 =9.72 GeV7) and a−1 = 4.86 GeV8) in our calculations.
We have found that the correlation function show largechanges across the deconﬁnement temperature, Tc ,in the scalar and axial-vector channel, while in thepseudo-scalar and vector channels only small changes
were observed. Correspondingly, no peaks in the scalar
and axial-vector spectral functions due to χc0 and χc1states for T > Tc were found, while the ηc and J/ψ
peaks in the pseudo-scalar and vector spectral functions are clearly observable at least up to temperatures 1.5Tc . Moreover, it seems, that the propertiesof ground state charmonia are not strongly aﬀected bydeconﬁnement. These ﬁndings are in agreement withthe calculations done using anisotropic lattices.4,5)
Naturally the question arises how far the existenceof charmonia states well above the deconﬁnement temperature can be understood in terms of color screening. On quite general grounds it is expected that thecolor forces between static quark and antiquark areexponentially screened beyond some distance Rsc . In
perturbation theory Rsc = 1/(g(T )T ) (if dynamicalquarks are absent), with g(T ) being the temperaturedependent gauge coupling. Non-perturbatively color
screening phenomenon was studied in terms of thecolor averaged free energy Fav (R, T ) (Polyakov loop
correlator).9,10) Very small screening radius was foundin these studies, which would indicate the dissolutionof all charmonia states. However, the free energy ofstatic quark-antiquark pair depends on whether thispair is in color singlet or color octet state. Thus in order to make contact with charmonium physics at ﬁnite
∗1
∗2
∗3

212

Fakultät für Physik, Universität Bielefeld, Germany
Physics Department, Brookhaven National Laboratory,
USA
John von Neuman Institute for Computing and DESY
Zeuthen, Germany

temperature the singlet free energy need to be studied
non-perturbatively. This was done in great details in
Refs. 11 and 12. Furthermore, the singlet free energy
contains also contribution from the entropy S1 (R, T ),F1 (R, T ) = U1 (R, T ) − T S1 (R, T ).11,12) The internalenergy U1 (R, T ) is most closely related to the conceptof static potential at T = 0 and it turns out that thescreening length extracted from this quantity is larger
than those extracted from Fav or F1 . It reaches thezero temperature J/ψ radius only around 2Tc . Thus
from the analysis of U1 (R, T ) one would conclude, thatcharmonia state may exist up to temperatures 2Tc
in accordance with lattice studies of the charmonium
spectral functions.
All the studies discussed above were done inquenched QCD. In order to make connection withheavy ion phenomenology the eﬀect of dynamicalquarks need to be studied. For the charmonium spectral functions this cannot be done with present computer resources (it would require about 10 Teraﬂops
computing power). However, the eﬀect of dynamicalquarks on singlet free energy of static quark-antiquark
pair can be estimated and will serve a valuable input
for quarkonium physics at ﬁnite temperature. Somepreliminary studies in this direction have already been
done12) and more detailed study with three diﬀerent lattice spacings and variety of quark masses is inprogress.13)
In conclusion, we have studied charmonium properties at ﬁnite temperature using MEM as well as the
singlet free energy of a static quark antiquark pair.
These studies indicate quite complex color screening
phenomenon in QGP.
References
1) T. Matsui and H. Satz: Phys. Lett. B 178, 416 (1986).
2) F. Karsch et al.: Z. Phys. C 37, 617 (1988); S. Digalet al.: Phys. Rev. D 64, 094015 (2001).
3) S. Datta et al.: Nucl. Phys. B (Proc. Suppl.) 119, 487(2003).
4) T. Umeda et al.: hep-lat/0211003.
5) M. Asakawa et al.: hep-lat/0308034.
6) M. Asakawa, Y. Nakahara, and T. Hatsuda: Prog.
Part. Nucl. Phys. 46, 459 (2001).
7) P. Petreczky et al.: hep-lat/0309191.
8) P. Petreczky: hep-lat/0310059.
9) O. Kaczmarek et al.: Phys. Rev. D 62, 034021 (2000).
10) F. Karsch et al.: Nucl. Phys. B 605, 579 (2001).
11) O. Kaczmarek et al.: Phys. Lett. B 543, 41 (2002).
12) O. Kaczmarek et al.: hep-lat/0309121.
13) P. Petreczky and K. Petrov: work in progress.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

MEM analysis of the thermal glueball from SU(3) lattice QCD
N. Ishii and H. Suganuma∗
Near the critical temperature Tc , one expects various onsets of the deconﬁnement transition in the QCD
vacuum such as the reduction of the string tension
and the partial chiral restoration. As a consequence,some hadrons are expected to exhibit the pole-mass reduction near Tc , as suggested by eﬀective-model studies.1–4) Indeed, these changes are considered as important precritical phenomena of the QCD phase transition in RHIC experiments, and corresponding lattice QCD calculations were attempted at the quenchedlevel recently.5–8) In this paper, we consider 0++ glueball, whose pole-mass reduction is suggested by an effective model based on the dual Meissner picture ofcolor conﬁnement.4)
In general, to study the pole mass of a hadron inlattice QCD, one ﬁrst constructs a temporal correlatoras G(τ ) = φ(τ )φ(0), and then resorts to its spectral∞
representation as G(τ ) = 0 dωK(τ, ω)A(ω), where))K(τ, ω) ≡ cosh(ω(β/2−τ
sinh(βω/2) , β ≡ 1/T , and A(ω) is the
spectral function with its spatial momentum projected
to zero, i.e., A(ω) ≡ A(ω, p = 0). Each peak position of A(ω) corresponds to a pole mass of a hadron at
T > 0. Usually, to extract A(ω) from G(τ ), one adopts
an ansatz to perform a ﬁt analysis. The most popular ansatz is the delta function, which is justiﬁed aslong as the peak is suﬃciently narrow. At T > 0, evena bound state may acquire a thermal width throughthe interaction with the heat bath, which can be considered with an advanced Breit-Wigner ansatz.8) Although the latter is rigid at low temperature, the shapeof the spectral function may become complicated nearand beyond Tc . In this case, it may be less trivial toﬁgure out a proper ansatz. Hence, it is desirable toperform the maximum entropy analysis of the glueballcorrelator at ﬁnite temperature,9) because it provides
us with a numerical procedure to reconstruct A(ω) directly from lattice QCD Monte Carlo results.10,11)
The glueballs are known to give only negligibly weakcontributions to the ordinary plaquette-plaquette correlator. To overcome this, we adopt a spatially extended glueball operator generated by the smearing
method with a ρ of suitable size.8) Note that the smearing method has a shortcoming, that is, it may create
an unphysical bump in the spectral function. However, since the actual low-lying glueball is a deﬁnite
bound state in quenched QCD below Tc , the problem
of unphysical bump is not serious. This is because thepole position in the complex ω plane is unaﬀected bya particular choice of the operators.8)
We reconstruct A(ω) for the smeared glueball correlator normalized as G(τ = 0) = 1.
∗

We adopt the Shannon-Jaynes
entropyas S ≡


∞
A(ω)
A(ω)
−
m(ω)
−
A(ω)
log
,
where
m(ω) ism(ω)
0real and positive, referred to as the default model function. m(ω) is required to reproduce the asymptotic
0
behavior of A(ω) as ω → ∞. We adopt the O(αS )2 per
4
turbative expression as m(ω) = N ω exp −(ωρ) /4 ,where the normalization factor
 ∞ N is determined to
mimic G(τ = 0) = 1, i.e., 1 = 0 dωK(τ = 0, ω)m(ω).
In Fig. 1, we show the reconstructed spectral functions of the lowest 0++ glueball at T = 130, 253, and
275 MeV. We use 5,500 to 9,900 gauge conﬁgurations
generated by Wilson action with βlat = 6.25 and therenormalized anisotropy ξ ≡ as /at = 4. The critical temperature is estimated as Tc  280 MeV from
Polyakov loop susceptibility. Since the error bar estimated by following Ref. 11 turns out to be unreasonably small, we do not show it to avoid unnecessary
confusion. For a reasonable estimate, the jackknife error estimator should be used.12) In Fig. 1, we see thetendency that the peak becomes broader with increasing temperature below Tc , which is consistent with theBreit-Wigner analysis of the thermal glueball correlator.8)

Fig. 1. Reconstructed spectral functions of the lowest 0++
glueball at T = 130, 253, and 275 MeV.

References
1) T. Hashimoto et al.: Phys. Rev. Lett. 57, 2123 (1986).
2) T. Hatsuda et al.: Phys. Rev. Lett. 55, 158 (1985).
3) T. Hatsuda et al.: Phys. Rev. D 47, 1225 (1993).
4) H. Ichie et al.: Phys. Rev. D 52, 2944 (1995).
5) QCD-TARO Collaboration: Phys. Rev. D 63, 054501(2001).
6) T. Umeda et al.: Int. J. Mod. Phys. A 16, 2215 (2001).
7) N. Ishii et al.: Phys. Rev. D 66, 014507 (2002).
8) N. Ishii et al.: Phys. Rev. D 66, 094506 (2002).
9) N. Ishii et al.: Nucl. Phys. B (Proc. Suppl.) 129/
130C, in press (hep-lat/0309102).
10) M. Jarrell et al.: Phys. Rep. 269, 133 (1996).
11) M. Asakawa et al.: Prog. Part. Nucl. Phys. 46, 459(2001).
12) N. Ishii et al.: work in progress.

Department of Physics, Tokyo Institute of Technology

213

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Lattice study of pion electromagnetic form factor withdomain wall fermions†,††Y. Nemoto
The pion electromagnetic (EM) form factor is oneof the simplest quantities in QCD. Some new experiments on this quantity at relatively large momentum
transfers are under way.1) While there exists a few
lattice computations, none of them respect the chiral symmetry suﬃciently well. The new experimental
data with small errors might not only impose strong restrictions on some phenomenological models, but give
stringent test of lattice QCD. We calculate the pion
EM form factor in the quenched lattice QCD using
domain wall fermions (DWF) with several momentum
transfers which partially cover the above experiments.
The DWF enables us to access lighter quark masses
than ever, because it has good chiral properties which
are quite important for the Nambu-Goldstone bosons
such as the pion.
We employ the DWF action for the quark action.
The number of sites in the ﬁfth direction is Ls = 12
and the domain wall height M5 = 1.8. Quark masses
are taken to be mq a = 0.08, 0.06, 0.04 and 0.02 whose
pion masses in the physical unit are approximately
760, 660, 540 and 390 MeV, respectively. The gauge
action is a renormalization-group-improved gauge action called DBW2 with the lattice size 163 × 32. The
gauge coupling is taken to be β = 0.87, which gives thelattice spacing a−1 ∼ 1.3 GeV and a suﬃcient spatial
lattice volume V = (2.4 fm)3 for a pion. The numberof conﬁgurations is 100. The explicit chiral symmetry
breaking due to the ﬁniteness of the ﬁfth direction Ls
is characterized by the residual mass mres . Our resultof mres after the chiral extrapolation is about 1.5 MeV,
which is much smaller than the quark masses mf .
The pion EM form factor Fπ (Q2 ) is deﬁned by
Fπ (Q2 )(pµ + pµ ) = π + (p)|jµ |π + (p ), where q 2 =−Q2 = (p − p )2 and jµ is the EM current. We note
Fπ (0) is the electric charge of a pion and we employ
this relation as a numerical check. The computation
method for the three-point function is as follows. We
use an appropriate smeared source and a local sink.
The separation between the source and the sink is 24
in the lattice unit. A momentum is injected at thesink and ﬂows into the current insertion, i.e., only one
quark propagator has a non-zero momentum. Thismethod is statistically eﬃcient for small momentum
transfers. The presently calculated momentum transfers of the form factor are p = (0, 0, 0), (1, 0, 0) and
†
††

214

Condensed from the article in Nucl. Phys. (Proc. Suppl.) tobe published; hep-lat/0309173
This work was carried out under RBC Collaboration. We
thank RIKEN, Brookhaven National Laboratory and the
U.S. Department of Energy for providing the facilities essential for the completion of this work.

(1, 1, 0) in the unit of 2π/La with the spatial latticesize L. They correspond to physical values of Q2 = 0,0.26, and 0.53 GeV2 , respectively. Larger momentum
transfers will be investigated in the near future. We
employ the sequential source technique when solving
the quark propagator with the ﬁnite momentum.
The EM current used here is the local current which
is not conserved on the lattice and requires operator renormalization before comparing with the matrix
element in the continuum. We have calculated therenormalization factor of the axial vector current, ZA ,nonperturbatively using lattice QCD. ZA is equal tothe vector current factor ZV in DWF and its chiralextrapolated value is ZA = 0.7798(5).
All the ﬁtted results of the pion EM form factor after
the renormalization are summarized in Table 1. We
see excellent agreement with unity for Q2 = 0 for thenumerical check. Quark mass dependence of the form
factors with the ﬁnite momenta seems to be rather
small, although they have relatively large statisticalerrors.
We have calculated the pion electromagnetic form
factor using the quenched DWF and DBW2 gauge action. Because of the good chiral and scaling propertiesof the action, we have investigated lighter quark masses
than ever. The present results with small momentum
transfers show a rather small quark mass dependence.
Calculations at larger momentum transfers are necessary for obtaining a functional form of the form factor to be compared with experiments, or models suchas vector meson dominance. Such calculations are now
under way.
Table 1. Fitted results of the pion EM form factor for each
Q2 [GeV2 ] and quark mass (100 conﬁgurations).
mf a
0.08
0.06
0.04
0.02

Q2 = 01.003(19)1.010(22)1.013(27)1.011(34)

Q2 = 0.26
0.783(24)0.779(31)0.761(44)0.689(77)Q2 = 0.53
0.603(48)0.583(73)0.564(138)n/aReferences
1) The Jeﬀerson Lab F(pi) Collaboration, J. Volmer et al.:Phys. Rev. Lett. 86, 1713 (2001); H. P. Blok, G. M.
Huber, and D. J. Mack: arXiv:nucl-ex/0208011.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Application of DWF to heavy-light mesons†N. Yamada, for the RBC Collaboration
Domain wall fermions1,2) (DWF) are expected tohave a negligible O(a) error as well as better control
over chiral extrapolations. Simulating light quarks using DWF beneﬁts from these advantages and has beensuccessfully used in the light hadron system.3–5) It is,then, natural to consider its application to the massive
quarks. We have started the simulation of D mesons
using DWF for both heavy and light quarks. In the following we will present a progress report on this study.
The gauge conﬁgurations are generated with thequenched DBW2 gauge action6) with β = 1.22 on
243 × 48 sites. The lattice spacing a−1 = 2.86(9) GeV
is obtained using mρ = 770 MeV. We set the extensionof the ﬁfth dimension and the domain wall height to
Ls = 10 and aM5 = 1.65, respectively. The light andheavy quark masses range in 0.008 ≤ amlq ≤ 0.040 and
0.1 ≤ amhq ≤ 0.5, respectively. Data presented below
is obtained with 20 conﬁgurations. The errors given
below are statistical only, unless otherwise speciﬁed.
The pseudo-scalar meson mass mD is used to ﬁx
amcharm . After the chiral extrapolation and interpolation in heavy quark mass, we ﬁnd amcharm = 0.380(4).
The mass splitting of mDs − mD is, then, obtained as
mDs − mD = 114(6) MeV.

(1)

While this value is about 15% larger than the experimental value (mDs − mD = 99 MeV), quenching may
account for much of the discrepancy.
The lattice calculation of the 1S hyperﬁne splitting
has been a long standing problem because the lattice
results are signiﬁcantly smaller than the experimental
values, independent of the heavy quark action adopted.
In this work we obtain mD∗ − mD = 69(6) MeV
and mDs∗ − mDs = 70(4) MeV. Comparing to theexperimental results of mD∗ − mD = 142 MeV andmDs∗ − mDs = 144 MeV, we see that this problem persists when using DWF.
The leptonic decay constants fP S are obtained ina standard way. Since relevant correlation functions
are still noisy, the resulting decay constants dependon the ﬁt ranges by as much as 10% which we takeas a systematic error in the following analysis. Figure 1 shows the chiral behavior of the decay constantat amhq = 0.4. Since the data with lightest light quark
looks suspicious, we performed linear extrapolations
with and without this data point. The diﬀerence between the two extrapolations are taken as a systematic
error again. After interpolation to amhq = amcharm ,we obtainlattfD= 200(9)(+20−21 ) MeV,†

(2)

Fig. 1. The chiral extrapolation of the pseudo-scalar decay
constant at amhq = 0.4.

lattfD
= 216(7)(22) MeV,s

(3)

where the systematic errors are summed up in quadrature. At present we quote the lattice bare values since
the renormalization constant has not been available
yet.
The SU(3) ﬂavor breaking ratio of the decay constant is one of the quantities for which lattice QCD
can attain a high precision. We can anticipate thatthe on-going charm experiments make it possible tomeasure this ratio at a few % accuracy, and so this is agood quantity for which to compare the lattice resultwith the experimental one although the uncertainties
in ms , the chiral extrapolation and quenching eﬀects
must ﬁrst be under control. Our current result is
fDs /fD = 1.08(3)(+2
−0 ).

(4)

We have started an exploratory study of massive
DWF aiming at precision lattice calculations of the
D meson system. To this purpose, we need to understand scaling violations well, especially those induced
by relatively larger mass parameters. We also needmore statistics to have better control over chiral extrapolations.
References
1) D. B. Kaplan: Phys. Lett. B 288, 342 (1992).
2) Y. Shamir: Nucl. Phys. B 406, 90 (1993); V. Furman
and Y. Shamir: Nucl. Phys. B 439, 54 (1995).
3) T. Blum et al.: arXiv:hep-lat/0007038.
4) CP-PACS Collaboration, A. Ali Khan et al.: Phys. Rev.
D 63, 114504 (2001).
5) Y. Aoki et al.: arXiv:hep-lat/0211023.
6) T. Takaishi: Phys. Rev. D 54, 1050 (1996).

Condensed from the article in Proc. 21th Int. Symp. on Lattice Field Theory (Lattice2003)

215

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RIKEN Accel. Prog. Rep. 37 (2004)

Static potential with dynamical domain-wall quarks†
K. Hashimoto∗ and T. Izubuchi∗
We report our ongoing calculation for the static
quark potential1) on two-ﬂavor lattice QCD withdomain-wall quarks.2) This project with dynamicalquarks has two purposes: (i) determination of lattice spacing, a, from the Sommer’s scale r0 = R0 a ≈0.50 fm3) and (ii) observation of string breaking whichis expected at large distance between quark and antiquark due to the pair creation of dynamical quarks.
Domain-wall fermion is one of the most ideal lattice
formulation of fermions which preserves symmetry ofchiral and ﬂavor rotations even at a > 0 in a good
approximation.
 is the potential energy
The static potential, V (R),between inﬁnitely heavy quark and anti-quark sepa in spacial direction and is obtained fromrated by R T ),
the Wilson loop, W (R, T ) ∼ C0 exp −V (R)TW (R,
+ C1 exp −V  (R)T(1)
 T ) is done on conﬁguraThe calculation of W (R,tions generated using two-ﬂavor dynamical domainwall fermion with Ls = 12, M5 = 1.8. Dynamicalquark masses are mf = 0.02, 0.03 and 0.04 whichcorrespond to mπ /mρ = 0.54(1), 0.60(1) and 0.64(1)respectively. We employ the improved gauge action,
DBW2, with β = 0.80 on 163 × 32 lattices. Inverse of
the lattice spacing from rho meson mass turns out to bea−1 ∼ 1.8 GeV. We implement Bresenham algorithm 4)of Computer Graphics which allows one to obtain the = (N1 , N2 , N3 )geodesic path connecting the ends of R
on lattice, where Ni are any three integers.
 is obtained from V (R) =The static potential V (R) tmin )/W (R, tmin + 1)) by omitting the secondln(W (R,term in Eq. (1). tmin is selected as the smallest time
distance to the plateau of V (R).
We measure V (R)with |R| < 10. Then the physical parameters are obtained from ﬁtting function:
 = σ|R| − CF αS + V0 ,
V (R)

|R|

1.65 − CF αS
,
(2)
R0 =
σ
where σ is the string tension and αS is the QCD coupling constants. Our preliminary results of the ﬁts
with the number of conﬁguration used and the ﬁtranges are tabulated in (Table 1). The lack of statistics(especially for mf = 0.04) currently prevent us from
more accurate determination as well as the informationof the excited state C1 , V  in Eq. (1).
†
∗

216

Work done with the RBC Collaboration
Institute for Theoretical Physics, Kanazawa University

Table 1. Preliminary results of fits for each dynamicalquark mass (statistical error only).
mf
0.02
0.03
0.04
# of conf.
820
410
130
# of traj./conf. 5
10
10(The length of MD time per one trajectory is 0.5)
√
√
√
rmin
√2
√2
√2
rmax
62
56
56
4
4
4
tmin
σ
0.08420(153) 0.08514(202) 0.08360(430)
0.3579(60)0.3488(88)0.3629(183)CF αS
3.917(27)3.909(34)3.924(74)R0

We measured r0 × (V (r) − V (r0 )) as a function of
r/r0 on NF = 0 quenched lattice (DBW2, β = 1.04,
a−1 ∼ 2 GeV)5) and that on NF = 2 dynamical(mf = 0.02) lattice in Fig. 1. One could see a deeper
Coulomb potential for NF = 2 (blank square) thanthat of quenched (ﬁlled circle) at small r ( r0 ). Thisdiﬀerence is consistent with the milder running of thestrong coupling constant in NF = 2 theory as a consequence of the quark’s contribution to the vacuum
polarization: αS (r, NF = 0) < αS (r, NF = 2).
 and T , the static potential is poorly
At large |R|
determined as seen from statistical errors in Fig. 1.
The smearing procedure (APE and/or HYP) is under
way in order to maximize the overwrap of the QCD T ) by which one might obtain the scale
string in W (R,with better accuracy. Also by controlling the overwrap
to the states in this way one might obtain enhanced
informations about the excited state which is hoped tobring the signal of the string breaking.

Fig. 1. r0 ×(V (r)−V (r0 )) vs. (r/r0 ) on NF = 0 (quenched)and NF = 2 dynamical (mf = 0.02) lattices.

References
1) G. S. Bali: Phys. Rep. 343, 1 (2001).
2) RBC Collaboration, T. Izubuchi: Nucl. Phys. B.
(Proc. Suppl.) 119, 813 (2003); RBC Collaboration, C.
Dawson: hep-lat/0310055 (2003).
3) R. Sommer: Nucl. Phys. B 411, 839 (1994).
4) B. Bolder et al.: Phys. Rev. D 63, 074504 (2001).
5) RBC Collaboration, Y. Aoki et al.: hep-lat/0211023(2002).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Kaon B parameter from two-flavor dynamical
domain wall fermions†T. Izubuchi,∗ for the RBC Collaboration
The kaon B parameter, BK , is an essential bridge
between K0 −K0 mixing experiments and the CabibboKobayashi-Maskawa matrix. Employing domain wall
fermions (DWF) as dynamical quarks would diminish
the unphysical operator mixing and O(a) errors as wellas the systematic errors from quenched approximation.
Using an improved HMC algorithm for DWF, wehave generated three ensembles of lattices of size
163 ×32 for two-ﬂavor QCD with degenerate dynamicalmasses of mdyn = 0.02, 0.03, 0.04, which are roughly
corresponding to 60, 90, 120 MeV quark masses in MS
2 GeV respectively. a−1 = 1.81(6) GeV from the rho
mass in mdyn to the chiral limit.1)
We evaluate the bag parameter, BPS (BK = BPS
when the pseudoscalars have the kaon mass), by theconventional method, where the ratio of a three-point
Green’s function and two pseudoscalar–axial-vector
correlators is taken. In Fig. 1, we show our results
latfor degenerate valence quark masses for eachfor BPS
diﬀerent value of mdyn . The ﬁlled points in the ﬁgure
have mdyn = mval . Our simplest result to report for
BK comes from extrapolating the mval = mdyn points
in Fig. 1 to mf = ms /2 ≡ 0.018. (A pseudoscalarwith two quarks with mf = ms /2 has the mass of thekaon.) We perform this extrapolation using the partially quenched formula



2
MPS
6
2
MPS log 2
BPS (m) = b0 1 −(4πf )2
ΛχPT2,+ b1 MPS(1)ﬁtting the three points with mval = mdyn , and ﬁndlat= 0.541(9) (statistical error only), with a small
BKχ2 /d.o.f. Note that we are using the known coeﬃcientof the chiral logarithm and ΛχPT = 1 GeV. The statistical error in the lattice spacing gives an additionallat, due to the
2% systematic error in the value of BK
uncertainty in the strange quark mass.
We have also ﬁt the dependence of BPS on mval to(1) for each ﬁxed mdyn , using the ﬁve values for mval .
lat(mval = ms /2, mdyn )The interpolated values for BK
are 0.537(11), 0.557(9) and 0.568(10) for mdyn = 0.02,
0.03 and 0.04 respectively.
We calculate B̂K , the renormalization group invarilat
via the multiplicativeant (RGI) parameter, from BK
renormalization
B̂K = Z RGI,RI−MOM (µ)
∆S=2
2
lat
× (ZQ
(µa)/ZA(µa))BK
(a)

(2)

MS
A similar equation is used for BK. Using NPR
RGI,RI−MOM ∆S=2
2
ZQ
/ZA
=
at mval = mdyn we ﬁnd Z∆S=22
1.29(4) and Z MS,RI−MOM ZQ/ZA= 0.93(2) at µ =2 GeV, which agree with the one loop perturbative calculation4) very well.
The preliminary results of our initial calculation of
BK with dynamical domain wall fermions is summarized for each dynamical lattice in Table 1. We see atrend toward lower values as the dynamical quark massis reduced. We have likely underestimated our statistical error, due to the long autocorrelation times, andwe have not yet studied chiral/continuume/volume extrapolations. However, it is clear that these dynamical
DWF calculations are possible with current computersand hold promise for the next generation of computers.

Table 1. Preliminary results for renormalized BK from valence quark extrapolations. For mdyn = 0.02, 0.03 and0.04 a 2% scale error has been included in the error on
the renormalized quantities.
mdyn
0.02
0.03
0.04
∞
∞

lat
BK
0.537(11)0.557(9)0.568(10)RBC2)
CP-PACS3)MS
BK(2GeV)
0.499(22)0.518(20)0.529(21)0.536(6)0.564(14)B̂K
0.692(34)0.719(32)0.733(34)

References
lat
BPS

Fig. 1.
for diﬀerent valence and dynamical masses.
The ﬁlled symbols have mval = mdyn .
†∗Condensed from the article in hep-lat/0310058
Institute for Theoretical Physics, Kanazawa University

1) RBC Collaboration, T. Izubuchi: Nucl. Phys. B, (Proc.
Suppl.) 119, 813 (2002); RBC Collaboration, C.
Dawson: hep-lat/0310055 (2003).
2) T. Blum et al.: hep-lat/0110075 (2001).
3) A. Ali Khan et al.: Phys. Rev. D 64, 114506 (2001).
4) S. Aoki et al.: Phys. Rev. D 67, 094502 (2003).

217

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RIKEN Accel. Prog. Rep. 37 (2004)

Kaon matrix elements in domain-wall QCD with DBW2 gauge action†
J. NoakiCalculation of the weak matrix elements on the lattice is one of the important step in the theoreticaltreatment of the non-leptonic kaon decays which has
CP asymmetry. In order to examine some of systematic errors which were not controlled in previous
works,1,2) we are performing an extensive quenchednumerical simulation on lattices with rather ﬁne spacing using the combination of domain-wall fermion andthe DBW2 gauge action. This choice improves chiralsymmetry and allows us to examine the eﬀect of thecharmed quark on the lattice as well as the scaling violation.
In Table 1, simulation parameters used in this calculation and preliminary results of the basic quantities
are summarized.3) The value of residual quark mass as
small as mres  0.3 MeV demonstrates the good chiral symmetry. Therefore, it is expected that the chiral symmetry breaking eﬀects due to the ﬁnite Ls are
negligible at least as to the local operator for Kaon
B-parameter. BK can be obtained on the lattice asa ratio of the matrix elements of the local operator
Q∆S=2 = [s̄γµ (1 − γ5 )d]2 and the axial current A4 .
Fit function BK = ξ0 [1 + Cmf a ln(mf a)] + ξ1 mf a isdemonstrated to ﬁt well with χ2/dof = 0.76, where thecoeﬃcient C is obtained analytically. Taking only statistical errors into account, our preliminary results areMS
to ZBK . Our result of BK(µ = 2 GeV) is consistent4)
with CP-PACS and the previous work of RBC.2)
In ∆I = 1/2 rule, matrix element of Q2 =(s̄u)L (ūd)L dominates the decay amplitude and thecharmed operator Q2c = (s̄c)L (c̄d)L also have contribution through the GIM mechanism. For these operators, the slope of the K → π matrix element as
a function of mf a are in proportion to K → ππ matrix
elements at the lowest order of chiral perturbation theory,5) where the unphysical eﬀect must be subtracted:

π + |Qi | K + subt = π + |Qi − αi Qsubt | K + ,

(1)

In Fig. 1, K → π matrix elements of Q2 (left) andQ2c = (s̄u)L (ūd)L (right) before and after the subtraction are shown. In particular, one ﬁnds that theslope of the subtracted matrix element of Q2c is muchsmaller than that of Q2 . It might mean a minor contribution of ππ |Q2c | K to ∆I = 1/2 rule.
Another important value for the test of Standard
Model,  /, also can be obtained in this calculation.
Since it requires much more statistics than we have sofar, our calculation is still ongoing.
We thank RIKEN, BNL and the U.S. DOE for providing the facilities essential for the completion of this
work.

latt
(mf a = 0.0155) = 0.552(11),BK
RI-MOMBK(µ = 2 GeV) = 0.542(11),MS,NDR(µ = 2 GeV) = 0.549(11),
BK

B̂K = 0.764(15).
In the step of non-perturbative renormalization, we observed that all elements of the amputated four-point
function in the chirality basis were less than 0.2% of
the (V V + AA, V V + AA) element which corresponds
Table 1. Simulation parameters and preliminary results ofbasic quantities.
lattice size:
243 × 48
gauge coupling: β = 1.22,#sweeps:
5,000 (BK ), 10,000 (K → π, meson)
domain-wall parameters: M5 = 1.65, Ls = 10
light quark mass:
mf a = 0.008 – 0.040, in step of 0.008
charmed quark mass:
mc a = 0.08, 0.12, 0.16, 0.20, 0.30, 0.40, 0.50
#configs.: 77 (BK ), 23 (NPR), 42 (mres ),50 (K → π, meson)a−1 = 2.86(9) GeV (mf a = 0, mρ = 770 MeV)
mres a = 9.73(4) · 10−5 (mf a = 0)†218

Condensed from the article hep-lat/0309175(0)Fig. 1. K → π matrix elements of Q2 (left) and Q2c(right, with mc a = 0.40) as a function of mf a. Circles,
squares and diamonds are standing for unsubtracted
matrix elements, subtraction term and subtracted matrix elements, respectively.

References
1) CP-PACS Collaboration, J. Noaki et al.: Phys. Rev. D
68, 014501 (2003).
2) RBC Collaboration, T. Blum et al.: Phys. Rev. D 68,
114506 (2003).
3) RBC Collaboration, J. Noaki: Nucl. Phys. B (Proc.
Suppl.) 119, 362 (2003).
4) CP-PACS Collaboration, A. Ali Khan et al.: Phys. Rev.
D 64, 114506 (2001).
5) C. Bernard et al.: Phys. Rev. D 32, 2343 (1985).

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RIKEN Accel. Prog. Rep. 37 (2004)

Lattice study of negative-parity baryon spectrum
Y. Nemoto, N. Nakajima,∗1 H. Matsufuru,∗2 and H. Suganuma∗3
Excited state baryons are still less known than the
ground state ones both theoretically and experimentally. From a theoretical point of view, the conventional quark model reproduces the low-lying excitedstates of baryons fairly well. However, it has still notbeen resolved how the quark model is derived from theﬁrst principle of the strong interaction, QCD. To gain
deeper insight into the connection between QCD andthe quark model, it is meaningful to compute the spectra of excited baryons from lattice QCD, and comparethem with the results of the quark model.
We investigate the low-lying negative-parity baryons
in the SU (3) ﬂavor octet, decuplet and singlet withthe standard Wilson gauge action and the O(a) improved Wilson quark actions. For accurate measurements of the masses of the negative-parity baryons,
we have adopted quenched anisotropic SU(3) lattice
QCD, in which the temporal lattice spacing is ﬁner
than the spatial one.1) The simulation parameters are
as follows. The sizes of the lattices are 123 × 96
3
(β = 5.75, a−1
σ = 1.034(6) GeV), 16 × 128 (β = 5.95,−13
aσ = 1.499(9) GeV) and 20 × 160 (β = 6.10, a−1
σ =1.871(14) GeV). The scale a−1isdetermined
from
the
σ
K ∗ meson mass. The anisotropy is ξ = as /at = 4,
where at is the temporal lattice spacing. On the quark
mass, we adopt four diﬀerent values, which roughly
cover around the strange quark mass. We use thestandard baryon operators which survive in the nonrelativistic limit. The negative-parity baryons can also
be measured by these operators using the parity projection. They are simply the parity partners of theground-state baryons. In the source operator, eachquark is smeared with the Gaussian function of thewidth ∼0.4 fm. The chiral extrapolation is taken linearly from lattice data.
Particular attention is paid to Λ(1405), which is considered to be the ﬂavor singlet baryon (qqq state) in
the naive quark model, or the exotic penta-quark state(q̄q-qqq). We have calculated the ﬂavor-singlet state
as a three-quark state on the lattice. We show theresults of the various baryon masses in the physicalunit in Fig. 1 for the β = 6.10 lattice. Note here thatthe ﬂavor-singlet baryon has one strange valence quark
and therefore the ambiguity from the chiral extrapolation should be less than that of the nucleon and thedelta. Nevertheless, the discrepancy between the lattice result and the experimental value of Λ(1405) is thelargest of all. Even if we take thequenching eﬀect of
∗1
∗2
∗3

Fig. 1. Various baryon masses from the β = 6.10 lattice.

10% level into account, this large discrepancy cannot
be understood. Therefore, the numerical result for the
ﬂavor-singlet baryon exhibits diﬀerent features fromother channels, which indicates that it is unacceptably heavier than Λ(1405). Thus, our result indicatesthat the three valence quark picture fails to represent
the experimentally observed Λ(1405), i.e., the overlap with the 3Q component of Λ(1405) is small. The
other possible candidate for Λ(1405) is a ﬁve-quark
N K̄ state. Lattice simulation of the N K̄ (ﬁve-quark)state would be interesting even at the quenched level,
where the dynamical quark-loop eﬀect including thequark-antiquark pair creation is absent and thus thequark-level constitution of hadrons is deﬁnitely clear
in the simulation.
References
1) N. Nakajima, H. Matsufuru, Y. Nemoto, and H.
Suganuma:
AIP Conf. Proc. 594, 376 (2001);
Y. Nemoto, N. Nakajima, H. Matsufuru, and H.
Suganuma: Nucl. Phys. A 721, 879 (2003); Y. Nemoto,
N. Nakajima, H. Matsufuru, and H. Suganuma: Phys.
Rev. D 68, 094505 (2003).

Center of Medical Information Science, Kochi Medical
SchoolHigh Energy Accelerator Research Organization (KEK)
Faculty of Science, Tokyo Institute of Technology

219

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RIKEN Accel. Prog. Rep. 37 (2004)

Nucleon on the lattice
Y. Aoki,∗1 S. Ohta,∗2 and K. Orginos∗3
We report the nucleon structure calculations by the
RIKEN-BNL-Columbia-KEK Collaboration. We havebeen applying a combination1) of the domain wall
fermions (DWF) and the “doubly blocked Wilson 2”(DBW2) improved gauge actions to study nucleon on
the lattice. The DWF preserves the chiral symmetryeven at ﬁnite lattice cutoﬀ by introducing a ﬁfth latticedimension in which the symmetry violation is exponentially suppressed. The DBW2 improvement helps theapproach to the continuum limit.
The simplest of the electroweak matrix elements are
the isovector vector (gV ) and axial (gA ) charges which
dominate the neutron β decay.2) With DWF their ratio
is renormalized up to O(a2 ), with a being the latticespacing. In Fig. 1 we show the ratio as a functionof the pion mass squared. The full-QCD results (diamonds) are consistent with the old quenched results(circles). This theoretical ﬁrst principles calculations,which do not yet include isospin breaking eﬀects, yields
a value of gA only a little bit below the experimental one, 1.2670 ± 0.0030. And the dependence on thequark mass is very mild. We have also calculated themoments of structure functions such as the quark momentum fraction, the ﬁrst moment of the transversity,and the moment d1 of the polarized structure functions, in both quenched and full QCD.
Figure 2 shows the result of nucleon decay matrix
elements. Any matrix element of nucleon decaying topseudoscalar meson via dimension-six operator can becalculated from those shown in the ﬁgure. We have
conﬁrmed the consistency between (preferable but

Fig. 2. Relevant form factor W0 for nucleon decay.

expensive) direct calculation and indirect one. We
have performed a non-perturbative renormalization(NPR) and have shown that there are no mixing atpractical level. The scheme matching calculation isunderway to get matrix elements in MS scheme. We
are performing an indirect calculation on the Nf = 2
dynamical domain-wall fermion conﬁguration, whichtells us the size of the quenching error in our results
shown here.
To summarize, the lattice calculations with DBW2
and DWF work well for nucleon matrix elements. The
axial to vector charge ratio is well reproduced to within
5% of the experimental value even with relatively
heavy quark mass. The dependence on quark mass
is very mild. Likewise the moments of structure functions xq , d1 , and 1δq all show mild linear dependence on quark mass, though some of them are yet tobe renormalized. Good chiral behavior was observed innucleon decay calculations, both for non-perturbative
renormalization and matrix elements themselves. We
will soon be able to report MS estimates of these matrix elements.
References

Fig. 1. Nucleon isovector axial to vector charge ratio,gA /gV , quenched (circle) and full QCD (diamond).
∗1
∗2
∗3

220

Physics Department, University of Wuppertal, Germany
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
Center for Theoretical Physics and Department of Physics,
Laboratory for Nuclear Science, Massachusetts Institute ofTechnology, USA

1) Y. Aoki et al.: arXiv:hep-lat/0211023; to appear in
Phys. Rev. D, and references cited there in; RBC Collaboration, Y. Aoki: arXiv:hep-lat/0309152; RBCK
Collaboration, S. Ohta and K. Orginos: arXiv:heplat/0309113, and references therein.
2) RIKEN-BNL-Columbia-KEK Collaboration, S. Sasaki,
K. Orginos, S. Ohta, and T. Blum: Phys. Rev. D 68,
054509 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Status of the QCDOC computer project
P. A. Boyle,∗1,∗2 D. Chen,∗3 N. H. Christ,∗2 M. Clark,∗1 S. D. Cohen,∗2 C. Cristian,∗2 Z. Dong,∗2 A. Gara,∗3
B. Joó,∗1 C. Jung,∗2,∗4 C. Kim,∗2 L. Levkova,∗2 X. Liao,∗2 G. Liu,∗2 R. D. Mawhinney,∗2 S. Ohta,∗5
K. Petrov,∗2,∗4 T. Wettig,∗6 and A. Yamaguchi∗2
The QCDOC (QCD On a Chip) project was started
in 1999 as a joint eﬀort of RIKEN, Columbia University and IBM Research to design a massively parallel super computer optimized for numerical calculations in lattice quantum chromodynamics (QCD).
The architecture combines state-of-the-art system-ona-chip technology with custom-designed logic specially optimized for lattice QCD calculations to provide computing power in the tens of TFlops range
at a price/performance ratio of 1 US$ per sustained
MFlops.1–5) The British UKQCD collaboration andthe US lattice community later endorsed the project.
Let us ﬁrst repeat what we described last year. The
QCDOC computer is a multiple-instruction, multipledata (MIMD) machine with distributed memory, justlike its predecessor, the QCDSP at Columbia University and RIKEN-BNL Research Center. While a single
processing node of the QCDSP consists of seven chips
assembled on a credit-card-sized board, now it is possible to integrate the components that make up a single
node on a single chip, creating an application-speciﬁc
integrated circuit (ASIC). The QCDOC chip is suchan ASIC, consisting of a) a 500 MHz, 32-bit PowerPC
440 processor core, b) a 64-bit, 1 GFlops ﬂoatingpoint unit, c) 4 MBytes of embedded-DRAM memory,d) controllers for embedded and external memories,e) a nearest-neighbor serial communication unit (SCU)
with latencies of 350 ns (550 ns) for supervisor (regular) transfers, overlapped between the 12 independent
directions and an aggregate bandwidth of 12 Gbit/s,
and f) other components such as an Ethernet controller, etc. Two such ASICs are mounted on a daughter board, together with two double data rate (DDR)
SDRAM modules (one per ASIC, up to 2 GByte each).
Thirty-two daughter boards are mounted on a motherboard, and eight mother boards in a crate with two
backplanes. The ﬁnal machine consists of a certain
number of such crates.
There are two separate networks: the physics
network and the Ethernet-based auxiliary network.
The physics network consists of high-speed serial
links between nearest neighbors with a bandwidth of
2 × 500 Mbits/s per link. The nodes are arranged in
∗1
∗2
∗3
∗4
∗5
∗6

a six-dimensional torus which allows eﬃcient partitioning of the machine in software. The SCU in the
ASIC provides direct memory access, single-bit error
detection with automatic resend, and a low-latency
store-and-forward mode for global operations. The
Ethernet-based 100 Mbit/s auxiliary network is used
for booting, diagnostics, and I/O, with an Ethernet
controller integrated on the ASIC. Hubs on the motherboard provide a bandwidth of 0.8 Gbit/s (decreased
from 1.6 Gbit/s) oﬀ a mother board to commercial
switches and the host workstation.
Development since the last year: The ﬁrst ﬁve prototype ASICs were delivered by IBM in June, 2003.
Many more have been produced following the successful testing of these ﬁve. The daughter board design was completed around the same time and wasused extensively in testing the ASIC. We now have
96 daughter boards. The ﬁrst mother board with
32 mounted daughter boards was successfully assembled and tested. Most notably the basic operating system and Dirac operator application now work on thismother board. A second mother board is being assembled, and will join the ﬁrst one to test the intercommunication between them. After this test succeeds,
the whole design will be signed oﬀ for the construction of production machines. We expect two 2-TFlops
peak prototype conﬁgurations in early 2004, and two
10-TFlops conﬁgurations, one for RBRC and the otherfor UKQCD, in the summer of 2004. The US community is in the process of deciding the size of their
QCDOC computer.
References
1) P. A. Boyle et al.: arXiv:hep-lat/0309096.
2) QCDOC Collaboration, P. A. Boyle, C. Jung, and
T. Wettig: arXiv:hep-lat/0306023.
3) P. A. Boyle et al.: Nucl. Phys. B (Proc. Suppl.) 119,1041 (2003).
4) P. A. Boyle et al.: Nucl. Phys. B (Proc. Suppl.) 106,
177 (2002).
5) D. Chen et al.: Nucl. Phys. B (Proc. Suppl.) 94, 825(2001).

Department of Physics and Astronomy, University of Edinburgh, UK
Department of Physics, Columbia University, USA
IBM Thomas J. Watson Research Center, USA
Department of Physics, Brookhaven National Laboratory,
USA
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
Department of Physics, Yale University, USA

221

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RIKEN Accel. Prog. Rep. 37 (2004)

The RHIC spin program: Where are we?
G. Bunce∗ and H. En’yo
RHIC completed its second run with polarized proton collisions in May 2003. The first run, in 2001/2,
established the first ever polarized proton collider, andprovided first measurements of cross sections
and spin√asymmetries in this new energy range, s = 200 GeV,
an order of magnitude above previous experiments.
This first run collided transversely polarized protons.
The second run introduced new spin rotators and established collisions of longitudinally polarized protons,
providing first data for longitudinal asymmetries thatare sensitive to the gluon polarization in the proton.
In this report, we discuss what we have learned so far,where we are in our program, and the issues that weneed to solve.
In the first spin run, a new method to measure thebeam polarization was introduced, giving very fastmeasurements with excellent sensitivity. Beam polarization measurements with 3% relative polarization
error were made in one minute every two hours during stored beam.1) The polarimeter was then used tomonitor the polarization during commissioning. Special new magnets were added to RHIC for the spin
program to prevent loss of polarization during acceleration. The sets of magnets, called Siberian Snakes,
were based on a new design for RHIC, and the Siberian
Snake concept had only been tested at very low energy.
The polarized protons were accelerated from 24 GeV to
100 GeV with little polarization loss, and the polarization was maintained through 8 hour stores. Thus, thefirst run demonstrated that the key concepts and devices needed for the spin program worked and worked
well.
The first run also provided important physics results
at this new energy. From the PHENIX experiment, themeasurement of the inclusive π 0 cross section versus
transverse momentum has been accepted for publication.2) In the letter it is shown that the cross section is
described by the hard scattering of quarks and gluons
from the colliding protons, over the full range measured, from pT = 2–14 GeV/c. This is a key result,confirming the theoretical basis of the spin program,even for lower pT , where spin asymmetries can be measured at low to moderate luminosity. The result isalso very important for the heavy ion program, since
it demonstrates that the production of π 0 at moderate
pT for heavy ion collisions is largely from hard scattering of quarks and gluons in the heavy ion beams.
Spin asymmetry measurements for the run, usingtransverse spin, showed very large spin asymmetries,
for very forward neutrons,3) and for forward π 0 .4) The
neutron asymmetry was used to set up spin rotators∗

222

Brookhaven National Laboratory, USA

at PHENIX for the second RHIC run. The forward
π 0 asymmetry, observed by STAR, may lead to a newunderstanding of the transverse spin structure of the
proton.
For the 2003 spin run, new spin rotators, designed
and built for RHIC, were used for the first time. The
rotators worked perfectly, providing longitudinal polarization at PHENIX and STAR. Both experiments
collected the first spin asymmetry data ever for longitudinally polarized proton collisions. The PHENIX experiment reported a preliminary result for the longitudinal spin asymmetry for production of π 0 in September.5) The asymmetry is surprisingly slightly negative,
where predictions, depending on the degree of gluon
polarization assumed, are positive. The result, which
may indicate that the gluon polarization is small, represents an important first result, with results still tocome from STAR. Future running with higher luminosity and polarization should give decisive results on
the gluon polarization, a major focus for the RHIC
spin program.
For the 2003 run, the luminosity was 4 ×1030 cm−2 s−1 , and polarization P = 0.3. The goalsof the RHIC spin program call for 20 times higher
luminosity, and P = 0.7. These goals will be thenext focus of the program. Luminosity improvements
are expected from selection of a new focusing value
to avoid resonances and beam loss, and new vacuum
pumping. Polarization improvement is expected fromnew Siberian Snakes that are being built for the AGS
injector.
The results so far demonstrate the creation of intense beams of polarized protons, acceleration to 100
GeV with little or no polarization loss, and routine
measurement of polarization. The experiments havesuccessfully developed triggers for high luminosity collisions, and have already observed large spin asymmetries. First measurements sensitive to gluon polarization have already been reported. The next emphasisof the spin program will be to improve luminosity andpolarization.
References
1) O. Jinnouchi et al.: AIP Conf. Proc. 675, 817 (2003).
2) PHENIX Collaboration, S. S. Adler et al.: Phys. Rev.
Lett. 91, 241803 (2003).
3) A. Bazilevsky et al.: AIP Conf. Proc. 675, 584 (2003).
4) STAR Collaboration, J. Adams et al.: accepted by
Phys. Rev. Lett.; hep-ex/0310058.
5) PHENIX Collaboration, S. S. Adler et al.: submitted
to Phys. Rev. Lett.

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RIKEN Accel. Prog. Rep. 37 (2004)

The PHENIX run 2003 and early results

We summarize the PHENIX data taking during the2003 run of the Relativistic Heavy Ion Collider at
Brookhaven National Laboratory.
The run was divided in two independent segments,
colliding deuteron and gold nuclei in the ﬁrst part andpolarized protons in the second part of the run. The
integrated
luminosity for the deuteron-Gold run was
LdAu dt = 2.7 nb−1 with peak luminosities reaching
LdAu = 2.2 × 1028 cm−2 s−1 . In the polarized proton
run Lpp dt = 352 nb−1 were collected, corresponding
to about 6.6×109 events. Peak luminosities during theproton run reached Lpp = 6 × 1030 cm−2 s−1 and thebeam polarization in RHIC typically was between 30
and 35%. A detailed critique of the RHIC accelerator
performance can be found in Ref. 2.
Just in time for the data taking the PHENIX detector did reach its full design conﬁguration in January
2003. Compared to the previous data taking period
in 2002 the most notable additions were 1) the North
Muon Spectrometer with its muon tracker cathodechambers and muon identiﬁer Iarocci-tube panels, 2)
two forward hadron calorimers for the event characterization in d-Au collisions and 3) scintillator hodoscopes
inserted at the location of the shower maximum into
the Zero Degree Calorimeter (ZDC). The combinationof information from the new shower maximum detectors and the ZDC was successfully used for measurements of the beam polarization at the PHENIX collision point.
In addition to the introduction of new detector hardware an important innovation was the signiﬁcant expansion of the online PHENIX computing facilities andthe simultaneous introduction of a strong on-line analysis group. Partial data streams of rare event triggers with low bandwidth requirements — for example,
the EMC-RICH trigger selecting events with clusters
where Ecluster > 3 GeV — were established by thisgroup. The resulting data samples were used to carryout physics level analysis tasks to obtain fast feedbackon the PHENIX detector performance.
At the same time the use of small partial data samples accelerated the analysis of selected physics channels of high interest: Figure 1 shows the ﬁrst measurement of longitudinal double spin asymmetries ininclusive neutral pion production3) at RHIC. The sizeof the statistical errors does not permit to constrain
the gluon polarization in the proton from our measurement. However, it is interesting to note that large0
negative asymmetries in AπLL at low pT are not compatible with perturbative QCD.4)
Figure 2 shows the nuclear modiﬁcation factor RdA∗

ALL

M. Grosse Perdekamp,∗ for the PHENIX Collaboration

0.1

π0 A LL from pp at s =200 GeV
PHENIX Preliminary
GRSV-max

0.05

GRSV-std
0

-0.05

-0.1

-0.15
0

Polarization scaling error~30% is not included
1

2

3

4

5

6

pT (GeV/c)0Fig. 1. The longitudinal double spin asymmetry AπLL observed in polarized proton collisions at RHIC. The data0
for AπLL are compared to predictions based on gluon
polarizations compatible with existing DIS data.1)

Fig. 2. The nuclear modification factor RdA for the inclusive π 0 cross section as function of the transverse momentum pT . For comparison RAA is shown for the 10%
most central events.

for inclusive π 0 production in deuteron-gold collisions.5) The absence of any supression pattern strongly
suggests that the suppression observed in gold-gold collisions is connected to ﬁnal state eﬀects due to the formation of a novel dense opaque nuclear media in heavy
ion collisions instead of nuclear eﬀects in the nucleon
parton distributions. These are truly exciting results
and were published within 2–3 months after data taking.
References
1) M. Glück et al.: Phys. Rev. D 63, 094005 (2001).
2) F. Pilat and T. Satagota: RHIC Retreat 2003, BNL,
http://www.agsrhichome.bnl.gov/AP/RHIC2003/
Retreat
3) A. Bazilevsky: Proc. 10th Workshop on High Energy
Spin Physics (Spin-03), Dubna, Russia, 2003-9, to be
published.
4) B. Jager et al.: hep-ph/0310197.
5) M. Grosse Perdekamp: RHIC Users Meeting, 2003-5; S.
Adler et al.: Phys. Rev. Lett. 91, 072303 (2003).

University of Illinois at Urbana-Champaign, USA

223

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RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of J/ψ with PHENIX muon arms
in 2003 p+p collisions
N. Kamihara,∗1 V. Cianciolo,∗2 V. Dzordzhadze,∗3 A. Glenn,∗3 D. J. Kim,∗4 K. Read,∗2,∗3 H. D. Sato,∗5
T.-A. Shibata,∗1 and A. Taketani
The PHENIX experiment at the Relativistic Heavy
Ion Collider (RHIC) is designed to explore many aspects of relativistic heavy-ion physics and high-energy
spin physics. One of the most important probes forboth physics is a J/ψ particle. The suppression of theJ/ψ production in heavy-ion collisions is regarded as astrong indication of the formation of the quark-gluon
plasma (QGP). The double longitudinal-spin asymmetry of the J/ψ production in polarized-proton collisions
determines the helicity distribution of the gluon (δg).
The PHENIX detector system consists of two muonarms to cover the forward rapidity region and two central arms to cover the central rapidity region. The
muon arms are designed to measure di-muons from thedecay of vector mesons (e.g. J/ψ) and single-muons
from the decay of the open heavy-flavor production
and W bosons. The two muon arms cover the pseudorapidity ranges of −2.2 < η < −1.2 (south muonarm) and 1.2 < η < 2.4 (north muon arm) with 2π
azimuthal-angle coverage.
The muon arms consist of a muon-tracker (MuTr)1,2)
subsystem, which tracks trajectories of charged particles to determine the momenta of the particles, and amuon-identifier (MuID)2,3) subsystem, which identifies
muons and triggers di-muon event candidates.
The south muon arm started operation during the
2001-2002 run period. In the 2003 run period, we madethe north muon arm ready for operation and updated
the di-muon trigger to handle both the south and northmuon arms. In 2003, the PHENIX recorded a total luminosity of 0.35 √pb−1 in longitudinally polarized proton collisions at s = 200 GeV with an average polarization of 27%.
The di-muon trigger is made using the MuID subsystem as a range counter. The trigger logic is configured by CAMAC modules and called the blue-logic
trigger (BLT). The MuID subsystem is a sandwich of
five wire-chamber panels and steel plates. Each wirechamber panel has one horizontal-wire layer and one
vertical-wire layer which comprise Iarocci-type plastic
tubes, and there are ten layers in total. For the trigger

∗1
∗2
∗3
∗4
∗5

224

Tokyo Institute of Technology
Oak Ridge National Laboratory, USA
University of Tennessee, USA
Yonsei University, Korea
Kyoto University

logic, each layer is divided into four (two horizontal
and two vertical) quadrants. Two coincidence logics
are configured in each quadrant: one is called the deep
trigger, which is configured with eight layers inside andrequires coincidence hits of seven layers, and the otheris called the shallow trigger, which is configured withfour layers inside and requires coincidence hits of threelayers. The di-muon trigger requires one deep trigger
in one quadrant and one shallow trigger in anotherquadrant. More detailed information about the muon
trigger system is described in Ref. 4.
For a preliminary J/ψ measurement analysis, dimuon trigger events are filtered out from all the
PHENIX raw data, and the di-muon invariant mass isreconstructed. Figure 1 shows a clear J/ψ mass peakat the correct invariant mass. The event reconstruction of the entire PHENIX raw data will start soon at
the RHIC computing facility.

Fig. 1. Invariant mass spectrum of north muon arm. The
filtered raw data was used.

References
1) H. Kobayashi et al.: RIKEN Accel. Prog. Rep. 35, 232(2002).
2) A. Taketani et al.: RIKEN Accel. Prog. Rep. 35, 224(2002).
3) H. D. Sato et al.: RIKEN Accel. Prog. Rep. 35, 225(2002).
4) H. D. Sato et al.: RIKEN Accel. Prog. Rep. 36, 240(2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Single muon analysis of polarized proton-proton collision√
at s = 200 GeV
A. Taketani, D. S. Brown,∗ O. Jinnouchi, and H. Kobayashi
It is expected that single-spin transverse asymmetry (AN ) is zero, from naive pQCD calculation. However the Fermilab E704 experiment reported large AN
in the reactions, using transversely polarized proton√
beams, (p↑ p → π + X and p↑ p → π − X) at s =19.4 GeV.1) The origins of asymmetries are considered
to be (1) initial state radiation, (2) ﬁnal state radiation, (3) higher twist eﬀect, or their combination. It
is interesting√ to measure the AN in the RHIC energy
region at s = 200 GeV. We pay attention to the inclusive muon production which is the decay product ofcharged pion or kaon.
PHENIX collected transversely
polarized proton√
proton collision data at s = 200 GeV in Run2 from2001 to 2002. The integrated luminosity was 0.15 pb−1
and the polarizations were 14% and 17% on average.
The PHENIX muon arm mainly consists of muontracker (MuTr) and muon identiﬁer (MuId). It covers 1.2 < |η| < 2.4 over full azimuthal range.2) In the
Run2, only the south arm, which covers −2.2 < η <−1.2, was installed and operated. The MuTr measuresthe charged particle momentum with 3 layers of chambers in the magnetic ﬁeld.2) It is designed such that∆p/p ∼3% at p = 3–10 GeV/c. The MuId identiﬁes
muons by using range counter that consists of 5 layersof chamber and iron absorber sandwiches. The muon
detection eﬃciency is saturated at p ∼ 2.5 GeV/c. Theµ/π rejection factor is about 10−3 . The MuId is also
used as a trigger counter.3)
The selection criteria of muon4) are based on thequality of reconstruction, matching between MuTr and
MuId segments, and event vertex position along thebeam axis. The muon yield depending on the event
vertex position was well explained by the decay product of charged pions and kaons.4) The 230 K tracks
were selected for this analysis. Muons from open heavy
ﬂavor decay will dominate higher Pt regions.
The transverse single spin asymmetry is deﬁned as
R
AN = P1 · σσLL −σ+σR , where P and σ are beam polarizationand cross section, and indices R and L represent rightand left.
We evaluated the systematic error of AN by measuring the detector acceptance asymmetry (εΩ ), andluminosity asymmetry (εB ). AN εΩ , and εB are described by using square root formule5) asNL↑ NR↓ − NL↓ NR↑ P AN (1 + O(ε3 )),↑ ↓↓ ↑NL NR + NL NR∗NL↑ NL↓ − NR↑ NR↓
 εΩ + P AN ε + O(ε3 ),↑ ↓↑ ↓NL NL + NR NRandNL↑ NR↑ − NL↓ NR↓
 εB + P AN ε + O(ε3 ),↑ ↑↓ ↓NL NR + NL NR
where N is the number of events, indices ↑/↓ represent
up/down beam polarizations, and ε is other asymmetries, and is expected to be less than 0.1.
εΩ is 30% and 40% for µ+ and µ− , respectively. Thisis due to the dead MuTr electronics. Since detector
acceptance terms during the derivation of Eq. (1) areexactly canceled out, this will negligible on the AN
measurement unless εΩ ∼ ±1. εB is varied from −5%
to 15% by beam condition. Again, this will afect verysmall on the AN .
We also employed the bunch shuﬄe method, inwhich bunch polarization direction is randomly shufﬂed, in order to estimate systematic error. Shuﬄed
AN should be distributed with zero average. Then the
RMS of the distribution is considered to be the systematic error for AN . It was measured as 0.01 whichis comparable to statistical error.
The systematic error for AN was evaluated. We are
re-analyzing Run2 data with better reconstruction eﬃciency. It is expected to have 25% to 50% more muonsand smaller εΩ . Then error for AN of 0.015 may be obtained. We have ﬁnished reprocessing Run2 data with
better track reconstruction program and will obtain
AN .
References
1) D. L. Adams et al.: Phys. Lett. 264, 462 (1991).
2) H. Akikawa et al.: Nucl. Instrum. Methods Phys. Res.
A 499, 537 (2003).
3) H. D. Sato et al.: RIKEN Accel. Prog. Rep. 36, 242(2003).
4) A. Taketani et al.: RIKEN Accel. Prog. Rep. 36, 228(2003).
5) H. Spinka: ANL-HEP-TR99-113 (1999).

(1)

New Mexico State University, USA

225

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)√
Identified hadron spectra in sN N = 200 GeV
p+p collisions at RHIC-PHENIX
S. Kaminaga∗ and S. Esumi∗√
To investigate QGP formation, sN N = 200 GeV
Au+Au collisions are studied at BNL-RHIC. In
Au+Au collisions, QGP phase formation and its recovery to the hadronic phase are expected. Hadronmeasurement reveals the final state of Au+Au collisions, and it is important to carry out systematic comparison of heavy-ion collisions with p+p collisions at
the same energy.
The RHIC-PHENIX detector has a strong identification capability by means of time-of-flight measurements with high resolution.1,2) The start and stop signals for the time-of-flight measurements are given bybeam-beam counter (BBC) and time-of-flight (TOF)
detector. The BBC also provides the minimum-biased
events by detecting a large number of particles near
the beam line. In heavy-ion collisions, the BBC triggers nearly 100% of the Au+Au cross section. However, multiplicities for p+p collisions are much lessthan those for heavy-ion collisions, and the BBC triggers only half of the p+p collisions. Therefore a BBCtriggered p+p event sample might have an unknown
trigger bias. In order to solve this problem, a time-zerocounter (TZC) has been installed for p+p collisions in2001. The TZC covers acceptance of TOF, thus it isexpected that particle identification using TOF and
TZC has a small trigger bias.
In this report, results of hadron analysis with TOFTZC particle identification (PID) are shown, namely,
mass square plot, mass2 resolution, and pt spectra for
TOF-TZC PID.
Figure 1 shows the mass2 distribution with TOFTZC PID in p+p collisions. The mass2 distribution
was calculated from momentum p, time of flight andflight path length. The 2σ PID cut was applied to thisanalysis. The contamination correction was estimatedhere and applied to the spectra.
Figure 2 shows the mass2 resolution for TOF-TZC
PID. The σT OF is the resolution of the time of flight,
and it is consistent to that expected from the design.
Figure 3 shows single-particle pt spectra with TOFTZC PID in p+p collisions. These spectra have beencorrected by Monte Carlo single-particle simulation.
As the next step, we will study the trigger bias bycomparing the BBC-triggered event sample and TZCtriggered event sample.

Fig. 2. Momentum dependence of mass2 resolution. f.p.ldenotes flight path length.

Fig. 3. Single-particle pt spectra of identified hadrons.

References2∗

Fig. 1. Mass vs. charge momentum.
∗

226

Department of Physics, University of Tsukuba

1) J. T. Mitchell et al.: Nucl. Instrum. Methods Phys. Res.
A 482, 491 (2002).
2) M. Aizawa et al.: Nucl. Instrum. Methods Phys. Res. A
499, 508 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of relative luminosity in polarized proton
collision at PHENIX
K. Tanida, for the PHENIX Collaboration
The main purpose of the polarized proton run at
PHENIX is to obtain information on the spin structure of protons by measuring the double spin asymmetry, ALL , of various channels. ALL is deﬁned by theasymmetry of the reaction cross section of two longitudinally polarized particles asALL =σ++ − σ+−,σ++ + σ+−where σ++ (σ+− ) is the cross section of a speciﬁc reaction channel with both particles having the same (opposite) helicity. Since the cross section can be written as experimental counting yield (N ) divided byintegrated luminosity (L) and overall detection eﬃciency (), which is safely assumed to be helicity independent, we can writeLL =N++ − RN+−,
N++ + RN+−

R=

L++
,
L+−

where LL is the raw asymmetry and is relevant to ALL
through beam polarizations (PB and PY ) as ALL =LL /(PB PY ). Here, R is called “relative luminosity”.
In order to accurately measure ALL , precise determination of R is necessary, asδALL =

2N++ N+−
1
1
δR ∼
δR.
2
PB PY (N++ + RN+− )2PB PYIn Run 3, the average polarization was about 27% andour goal of ALL accuracy was 3 × 10−3 , and thus δR
must be smaller than 4 × 10−4 .
In the PHENIX experiment,1) relative luminosity
and its accuracy were estimated as follows: We counted
the number of coincidence of two Beam-Beam Counters (BBCLL1 trigger) for each bunch crossing andused it as an unnormalized luminosity for that crossing.
Since BBCLL1 was free from backgrounds (∼ 10−4 ofall triggers) and had very high statistics, it is an ideal(relative) luminosity monitor. Then we calculated R
for each ﬁll as we had all four combinations of helicities[(++), (+−), (−+), and (−−)] in one ﬁll.
To estimate the accuracy of relative luminosity, another trigger from Zero Degree Calorimeter (ZDCLL1
trigger) was used. ZDCLL1 was also free from backgrounds though its statistics was ∼ 30 times smaller
than that of BBCLL1. Ideally, the ratior(i) =NZDC (i)NBBC (i)is a constant independent of crossing number i. This
assumption was checked by χ2 of a ﬁtting to
ZDC/BBCr(i) = C[1 + LL
SB (i)SY (i)].

Here, the second term in the bracket of r.h.s. was introduced to implement the possible eﬀect of ALL in
BBCLL1 and ZDCLL1, and SB (i) and SY (i) represent the signs of helicity for crossing bunches [1(−1)
for positive (negative) helicity].
The reduced χ2 (χ˜2 ) of the ﬁtting signiﬁcantly deviated from unity for most of the ﬁlls. It was found that
this is mostly due to the crossing-by-crossing diﬀerencein collision Z-vertex distribution. Although the two
triggers selected the same region (|Zvert | < 30 cm), theZ-vertex resolution of ZDCLL1 was worse (σ ∼ 20 cm)
than that of BBCLL1 (σ ∼ 5 cm). Due to this difference, ZDCLL1/BBCLL1 ratio increases as Z-vertex
distribution broadens.
After correcting r(i) for this eﬀect, the obtained χ˜2
was consitent with unity for most of the ﬁlls, as shownin Fig. 1. As there are still ﬁlls whose reduced χ˜2 issigniﬁcantly
 larger than unity, we increased statisticalerror by χ˜2 if χ˜2 > 1.a)
BBC/ZDC

Averaging over ﬁlls, we obtained LL= (1.3 ±1.3) × 10−4 . The error corresponds to δALL = 1.8 ×
10−3 or δR = 2.5 × 10−4 and satisﬁes the Run 3 goal.
We are continuing our work to further improve thisanalysis by studying other possible eﬀects.

Fig. 1. Distribution of χ˜2 (χ2/DOF) after applying correction for Z-vertex width. The dotted curve is theideal distribution, normalized to the number of analyzed fills (47).

References
1) PHENIX Collaboration, K. Adcox et al.: Nucl. Instrum.
Methods Phys. Res. A 499, 469 (2003).

a)This correction gives conservative error estimation becauseχ˜2 can be larger than unity by statistical fluctuation alone.

227

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RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of AN of inclusive particles by PHENIX BBC withtagged very forward neutron in polarized pp collisions at√
s = 200 GeV
K. Tanida, for the PHENIX Collaboration
polarized protons at√ In the collision of transverselys = 200 GeV, it is reported1) that very forward neutron has a large single spin asymmetry (AN ) of approximately −10%. The mechanism of this asymmetry is of interest, and the measurement of AN of coincident particles provides valuable information on it.
For example, if the neutron asymmetry comes from
diﬀractive-like processes, i.e.,p + p → N ∗ (∆∗ ) + X1 ,N ∗ (∆∗ ) → n + X2 ,it is expected that AN of X2 , which is detected by forward counters, has the same sign as the neutron, andthat the sign is opposite for backward particle(s), X1 .
PHENIX Beam-Beam Counter (BBC) is suitablefor detecting these coincident particles since it covers forward and backward regions (pseudorapidity
3.0 < |η| < 3.9). Here, we describe the result on AN in
BBC with very forward neutron tagged by Zero Degree
Calorimeter (ZDC). See Ref. 2 for the descriptions of
the BBC, ZDC and other detectors in PHENIX.
Except that neutron hits were tagged, the analysis
procedure was mostly the same as that in last year’s report,3) where measurement of AN of inclusive charged
particles at BBC was described. Neutrons were selected in the following way. Because the DX magnet is
located in front of ZDC, only neutral particles (γ, n,and KL ) were detected. Since ZDC has three telescope segments of 20 cm thick tungsten each and γ’scannot penetrate the ﬁrst segment, we were able to select hadrons by requiring a hit in at least one of thesecond and third segments. Contamination of KL wasestimated to be 2–3% and was neglected. We performed a realistic detector simulation and estimatedthe purity of neutron tagging to be 86%, with the main
background being γ’s which hit the light guide of ZDC.
For reference, γ tagging was also performed by selecting a hit only in the ﬁrst segment; according to thesame detector simulation, the purity of γ tagging is
52%, with a severe contamination of neutrons (42%).
We then calculated asymmetries for each beam ﬁll,
using the bunch ﬁtting method.3) Distribution of reduced χ2 of the ﬁtting was consistent with the expected χ2 distribution so that no systematic error was
suggested here.
The preliminary results are AN = [−4.86 ±
0.54(stat.) ± 0.42(syst.)] × 10−2 for particles detectedby forward BBC and AN = [2.46 ± 0.59(stat.) ±0.21(syst.)] × 10−2 for backward particles with forward neutron tagging. The systematic errorinclude228

uncertainties in the event selection and treatmentof backgrounds in neutron tagging, but not that inbeam polarization. Consistency between physicallyequivalent measurements (i.e., AN obtained by BBCnorth and BBC-south) was checked and was ﬁne.
Parity-violating asymmetry (top-bottom asymmetry)
was also checked and conﬁrmed to be consistent withzero. When the backward neutron was tagged, theasymmetries were consistent with zero in both forward
and backward BBCs. The asymmetries were also consistent with zero for γ-tagged events after subtracting
the eﬀect of neutron contamination in the γ tagging.
The present results of AN are consistent, at least
qualitatively, with the simple picture of diﬀractivelike processes mentioned above. On the other hand,
there is another possibility for the AN of forward
neutron based on the result of FNAL E704.4) They+0observed a positive AN for√ forward π and π and−a negative AN for π at s = 20 GeV. Also, STAR
reported
that the AN for forward π 0 survives even√at s = 200 GeV,5) and that they observed positive
asymmetry at their BBC,6) where more π + is expected
than π − . Hence, a possible explanation is that the neutron asymmetry is caused by a recoil of π + which is
kicked out of a proton. However, it is quite diﬃcult
to explain the present results by this mechanism since
the π + is very likely detected by BBC so that forward BBC asymmetry becomes positive. Therefore,
the present result suggests the mechanism for AN invery forward neutron is diﬀerent from that of forward
pions observed by FNAL E704 and STAR.
We are still working on the data analysis to understand systematic errors better. Also, analysis of datataken in FY 2003 is starting to obtain higher statistics
and to measure AN using other detectors with forward
neutron tagging for better understainding of the reaction mechanism.
References
1) Y. Fukao et al.: RIKEN Accel. Prog. Rep. 36, 232(2003).
2) PHENIX Collaboration, K. Adcox et al.: Nucl. Instrum.
Methods Phys. Res. A 499, 469 (2003).
3) PHENIX Collaboration, K. Tanida et al.: RIKEN Accel. Prog. Rep. 36, 229 (2003).
4) D. L. Adams et al.: Phys. Lett. B 264, 462 (1991).
5) STAR Collaboration, G. Rakness et al.: AIP Conf.
Proc. 675, 400 (2003).
6) STAR Collaboration, J. Kiryluk et al.: AIP Conf. Proc.
675, 424 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of longitudinal double spin asymmetry for π 0 ’s in√proton-proton collisions at s = 200 GeV
from RHIC PHENIX Run 3
A. Bazilevsky, C. Aidala,∗1 F. Bauer,∗2 A. L. Deshpande, Y. Goto, Y. Fukao,∗3 B. Fox, T. Horaguchi,∗4
K. Okada, K. Tanida, and H. Torii, for the PHENIX Collaboration
Measurement of the gluon polarization in a polarized proton is a major goal of the RHIC-Spin program. It can be probed through the longitudinal double spin asymmetry (ALL ) in high pT hadron production.1) During the year 2003 run, RHIC was successfully operated for the ﬁrst time as a collider of longitudinally polarized protons at a center of mass energy
of 200 GeV. We present the ﬁrst PHENIX results on
ALL for π 0 in four pT bins in the range of 1–5 GeV/cobtained from the data corresponding to the integral
luminosity of 0.215 pb−1 , the average beam polarization being 26%.
To calculate ALL , we measured the number of π 0 ’s(N ) and integral luminosity (L) from the colliding protons with the same (++) and the opposite (+−) helicity:ALL =N++ − RN+−
1,
|PB ||PY | N++ + RN+−

R=

L++
,
L+−

(1)

where PB and PY are beam polarizations.
For the relative luminosity (R) measurements,2) weused beam-beam counters.3) The achieved relative luminosity precision was δR = 2.5 × 10−4 , which corresponded to δALL = 1.8 × 10−3 .
The PHENIX Local Polarimeter4) was used to measure the longitudinal component of the spin of thebeams as well as to conﬁrm the spin direction.
High pT π 0 ’s were collected using an electromagnetic-calorimeter-based high pT photon trigger(ERT5) ). The trigger eﬃciency for π 0 ’s varied from 6%in the 1–2 GeV/c pT bin to 95% in the 4–5 GeV/c pTbin. The number of π 0 ’s was obtained by integrating
the counts under π 0 peak in ±25 MeV/c2 mass window
in two photon invariant mass distributions. The background contribution (combinatorial+hadronic) varied
from 45% in the 1–2 GeV/c pT bin to 5% in the 4–
5 GeV/c pT bin.
ill
The spin asymmetry for each beam ﬁlla) AfLL
was
illerror evaluation,
calculated using Eq. (1). For the AfLL
we considered only the statistical error on N :σ f ill =A
LL

σN++ +N+−
1·.
|PB ||PY | N++ + N+−

The statistical error is given by σN =
∗1
∗2
∗3
∗4

Brookhaven National Laboratory, USA
University of Riverside, USA
Kyoto University
Tokyo Institute of Technology

N ev is the number of recorded events and k is countmultiplicity per√ event. In a “Poisson limit” (k is always
0 or 1) σN = N .
The resulting ALL was obtained after the ﬁttingill’s to a constant. The ﬁtting χ2 as wellof all AfLL
as “bunch shuﬄing” technique were used to conﬁrm
the errors assigned to ALL ’s. In each “bunch shufﬂing” we randomly assigned the helicity sign to everybunch crossing and did the whole procedure to calculate ALL and χ2 described above. Mean values ofχ2 /NDF (NDF is the number of degrees of freedom)
were very close to unity in all pT bins. The widths ofthe distributions of ALL values for N obtained in allbunch shuﬄes were consistent with errors assigned to
ALL ’s. It denotes that errors were properly assigned
to ALL values. In other words, all other noncorrelated bunch-to-bunch and ﬁll-to-ﬁll systematic errors
are much less than N π0 statistical errors. (Certainly,
it does not exclude correlated systematic errors for allbunches and ﬁlls, such as the error on polarization).
Figure 1 shows our ALL results after backgroundALL subtraction (points) as well as theory prediction
curves.6) The ALL of background was estimated forthe counts adjacent to the π 0 peak in two photon invariant mass distributions. The obtained sensitivity
is not yet suﬃcient to discriminate between diﬀerent
gluon polarization models. The expected statistics andbeam polarization in the next runs (in 2004–2005) will
decrease the error bars 3–7 times.

(2)√k¯2 N ev , where

0Fig. 1. The measured double spin asymmetry AπLL vs. thepT with two theoretical curves shown for diﬀerent gluon
polarizations6) .
a)Each fill is characterized by a constant polarization of thebeams.

229

References
1) A. Bazilevsky et al.: RIKEN Accel. Prog. Rep. 34, 243(2001).
2) K. Tanida: RIKEN Accel. Prog. Rep. 37, 227 (2004).
3) M. Allen et al.: Nucl. Instrum. Methods Phys. Res. A
499, 549 (2003).

2304) A. Deshpande et al.: RIKEN Accel. Prog. Rep. 37, 246(2004).
5) K Okada et al.: RIKEN Accel. Prog. Rep. 36, 248(2003).
6) B.Jäger et al.: Phys. Rev. D 67, 054005 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of π 0 production in p+p and Au+Au collisions at√
sN N = 200 GeV†
H. Torii, A. Bazilevsky, B. Fox, Y. Goto, and K. Okada for the PHENIX Collaboration
In this paper, two independent but strongly related topics are discussed. One is about a testing
ground of the perturbative quantum chromodynamics (pQCD) theory and the other is the medium eﬀect
in heavy ion collisions, the suppression of particle production at high pT which is predicted as a Quark Gluon
Plasma (QGP) signature.1) In the ﬁrst part, we will
prove that our measurements in p+p collisions can be
described by the pQCD theory. Next, we will compare
the measured medium eﬀect in Au+Au collisions withthe p+p data. This study used PHENIX electromagnetic calorimeters, which have an azimuthal coverageof 90◦ + 90◦ and a pseudorapidity coverage of ±0.35.
The data were collected during the p+p and Au+Auruns in 2001–2002 at RHIC.
In Fig. 1, our results of π 0 production in the p+p
data are compared with next-to-leading order (NLO)
pQCD calculations.2) The calculations have been performed with the same renormalization and factorization scales of pT by using the CTEQ6M3) set of parton distribution functions and two sets of fragmentation functions: “Kniehl-Kramer-Pötter” (KKP)4) and“Kretzer”.5) The calculation with the former agrees
with our data better than that with the latter. These
two sets diﬀer mainly in that the gluon-to-pion fragmentation function, Dgπ , is greater in the KKP set.
This diﬀerence is exhibited primarily at low pT becauseof the dominance of gluon-gluon interactions. We conclude that the π 0 production in p+p collisions in thisenergy region are described well by the pQCD calculation.
In Au+Au collisions, we quantify the medium ef-

fects with the nuclear modiﬁcation factor given by
the ratio of the measured Au+Au invariant yields to
the N N -collision-scaled p+p invariant yields: RAA =
◦

◦

π
π
d2 NAuAu
d2 σ pp/(Ncoll  × σinel), where Ncoll  is the
evt
NAuAu
dpT dydp
T dypp

average nucleon-nucleon collision estimated by the
Glauber model. RAA (pT ) measures the deviation of
AA data from an incoherent superposition of N N
collisions. Figure 2 shows RAA as a function of pT
measured in the 0–10% central and 80–92% peripheral Au+Au collisions. Within errors, the peripheral collisions behave similarly to a superposition of
N N collisions. The RAA values for the central collisions, however, are notably below unity, as observed
at 130 GeV,6) and in contrast to the enhanced highpT π 0 production (RAA > 1) observed at CERN-SPS
energies.7)
In summary, we have discovered signiﬁcant suppresion of the π 0 production in the central Au+Au collisions compared to an incoherent superposition of N N
collisions. This observation is consistent with the theoretical model, jet quenching, predicted as a QGP signature.1)

Fig. 2. Nuclear modiﬁcation factor RAA (pT ) in central andperipheral Au+Au collisions. Error bars include statistic and systematic errors. Shaded bands represent thequadratic sum of fractional uncertainties in Glauber calculation and π 0 yield normalization.

References

Fig. 1. a) Invariant diﬀerential cross section for inclusiveπ ◦ production in p+p collisions and the results of NLO
pQCD calculations.2–5) See the text for details. b) The
relative statistical (point) and point-to-point systematic(band) errors.
†

Condensed from the article in Phys. Rev. Lett. 91, 072301(2003); Phys. Rev. Lett. 91, 241803 (2003)

1) X. N. Wang et al.: Phys. Rev. D 44, 3501 (1991).
2) F. Aversa et al.: Nucl. Phys. B 327, 105 (1989); Private
communication with W. Vogelsang.
3) CTEQ Collaboration, J. Pumplin et al.: J. High Energy
Phys. 07(2002)012.
4) B. A. Kniehl et al.: Nucl. Phys. B 597, 337 (2001).
5) S. Kretzer: Phys. Rev. D 62, 054001 (2000).
6) PHENIX Collaboration, K. Adcox et al.: Phys. Rev.
Lett. 88, 022301 (2002).
7) WA98 Collaboration, M. M. Aggarwal et al.: Eur. Phys.
J. C 23, 225 (2002).

231

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RIKEN Accel. Prog. Rep. 37 (2004)

Simulation studies for the Si-Vertex Tracker at PHENIX√
photon-jet production in pp collisions at s = 200 GeV
M. Togawa,∗ Y. Akiba, H. En’yo, Y. Goto, K. Imai,∗ V. L. Rykov and N. Saito∗
Direct photon production is a key process of measuring the gluon distribution of nucleons and the polarization of gluons. At RHIC energies, quark-gluon
Compton scattering, q + g → q + γ, is the dominantparton-level process in high-pT direct photons. In pp
collisions, the cross section of this process is directly
proportional to the quark and gluon densities multiplied by the pQCD cross section. Thus, measuring a
direct photon together with a recoil jet is a direct andclean method of measuring the gluon density and polarization. With the present PHENIX setup, direct
photons are measured with ﬁnely segmented electromagnetic calorimeters (EMCal) in central arms. However, most of the recoil jets cannot be measured dueto the limited coverage of the central arms.
The Si-Vertex Tracker (VTX) is proposed as a
PHENIX upgrade,1,2) that works as a large solid angle
charged particle tracker and the expected momentum
resolution is approximately 10% for a 1 GeV/c track.3)
This resolution is suﬃcient to reconstruct the recoil
jets. With the knowledge of the recoil jet, we can constrain the initial kinematics (x1 and x2 ) of incoming
partons and thus determine the gluon density and polarization as a function of x.
We have studied the potential improvements due tothe VTX in a Monte Carlo simulation. In this simulation, the direct photon events are generated using
the PYTHIA event generator. The recoil jet is reconstructed from the charged tracks within the VTX
detector acceptance (|η| < 1.2), but in the opposite
azimuthal direction of the direct photon. In the ﬁrst
step of the algorithm, tracks with momenta greaterthan 1.0 GeV/c at an azimuthal angle opposite to thedirect photon (|φ − φγ | > π/2) are selected. Then, thedirection of the jet is estimated to be the momentum
weighted average of the selected tracks.
 i i
 i i
η pT
φp
jet
jet
η =  i , φ =  iT
(1)
pT
pT
Next, the tracks within the cone radius, R =(η jet − η i )2 − (φjet − φi )2 , are selected (R < 0.5).
This procedure is iterated until the direction of theaxis no longer changes.
From the measurement of ηjet and the transverse
momentum pT of the direct photon, the kinematicsof the initial partons can be determined. Under theassumption that the pT values of the direct photon andthe recoil jet are the same, the fractional momenta of
the initial partons x1 and x2 are calculated to be,∗232

Department of Physics, Kyoto UniversitypT
x1 = √ (exp(η jet ) + exp(η γ )),
(2)
s
pT
(3)
x2 = √ (exp(−η jet ) + exp(−η γ )).
s
The two panels in Fig. 1 show the correlation between the x calculated as mentioned above (reconstructed x) and its true value is from the event generator (true x). If the recoil jet direction is not known(left panel) the best estimate for x based on the photon
pT is only loosely correlated to the true x. However,with the recoil jet reconstruction (right panel) there isa narrow correlation between the reconstructed x andtrue x.
In Fig. 2, (reconstructed x − true x)/true x is shown
as a function of x1 , and the error bar shows thesewidths (RMS). In the range of x > 0.04, the x values are determined with an accuracy of ∼20%.

(a)(b)
Fig. 1. Correlation between reconstructed x and true x
from PYTHIA. These samples are chosen as γpT >4.0 GeV/c. (a) no jet information has been used (cal√culated as 2pT / s). (b) is obtained using the reconstructed jet axis in the barrel VTX.1)

Fig. 2. (reconstructed x − true x)/true x is shown as afunction of x1 , and the error bar shows these widths(RMS).1)

References
1) Y. Akiba et al.: Proposal for Silicon Vertex Tracker(VTX) for the PHENIX Experiment (BNL, upon 2003).
2) Y. Goto et al.: RIKEN Accel. Prog. Rep. 37, 249(2004).
3) Y. Goto et al.: RIKEN Accel. Prog. Rep. 36, 249(2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Charged hadron analysis in proton-proton collisions at√
s = 200 GeV

K. Okada and J. Jia,∗ for the PHENIX Collaboration
As a probe of the high-energy density matter created in relativistic heavy ion collisions, we can use
charged hadrons, which are produced through the initial parton-parton interactions. With medium eﬀects,
charged hadron transverse momentum spectra are expected to be distorted from the scaling of those frominelastic nucleon-nucleon interactions.
The√data of p + p collisions at a center of mass energy ( s) of 200 GeV collected during the 2001–2002
run period (Run2) provide the basic knowledge for
Au+Au collisions in the same energy per nucleon. In
this article, we report the analysis procedure of inclusive charged hadron production with 21 million vertex
triggered events.
We use the East central tracking spectrometer in
PHENIX.1) The key detectors in this analysis are, fromthe collision point to the outside, Beam-Beam Counters (BBC), the drift chamber (DC), the pad chamber(PC1), the ring image cherencov counter (RICH), another pad chamber (PC3), and the ElectromagneticCalorimeter (EMC). The magnetic ﬁeld ( B · dl =0.78 [T · m]) exists inside the DC radius.
Particles reconstructed in BBC, DC, and PC1 include many fake ones. At ﬁrst, PC3 hit matching isapplied. Because of the absence of a tracking system
inside the magnetic ﬁeld in PHENIX, in the case that aphoton converts to electrons in front of DC or a particle
decays in ﬂight, the kick oﬀsets the magnetic ﬁeld kick;such daughters are assigned as an incorrect momentum. Here the statistical subtraction method2) wasapplied. The conversion electron contamination was
estimated by using RICH. The decay daughter backgrounds are mostly low momentum particles which canbe bent by the residual ﬁeld outside the DC radius.
This results in the broadening of the PC3 hit matching. Its matching shape is independent of the appeared
momentum. Figure 1 shows how background subtraction works.
For the correction of the acceptance and the momentum smearing, Monte Carlo simulation is performed.
After tuning detector dead region, the correction factor deﬁned by the ratio of number of particles reconstructed to the input is approximately 13. This is consistent with the simple estimation from (∆η · ∆φ/2π ·DC+P C1 · P C3 )−1 = (0.5 · 0.25 · 0.75 · 0.82)−1 , whereDC+P C1 and P C3 are mainly determined by the livearea.
The integrated luminosity is determined from thenumber of BBC triggered events using an absolute calibration of the trigger cross section obtained via thevan der Meer scan technique. From this measurement,∗

Fig. 1. Yield.

our BBC trigger is approximately half (21.8 ± 0.9 mb)of total inelastic interactions.3) The next question isabout trigger bias. In the neutral pion analysis,3)
events with pion production tend to be triggered by
0.75/0.52 independent of the pion momentum above
1 GeV/c. For events with charged hadron production,
PC+EMC tracking is used for the BBC unbiased sample. The result is consistent with the neutral pion results, with a slight drop in the lower pT region (Fig. 2).
This analysis will be ﬁnalized by the end of 2003.

Fig. 2. BBC trigger bias study with PC track. 0.75 is theresult of π 0 . The drop in the high pT region is due tomomentum resolution of PC+EMC tracking.

References
1) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res. A
499, 469 (2003).
2) J. Jia: Ph.D. Thesis, State University of New York at
Stony Brook (2003).
3) S. S. Adler et al.: Phys. Rev. Lett. 91, 241803 (2003).

Columbia University, USA

233

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RIKEN Accel. Prog. Rep. 37 (2004)

Background study of direct photon production in proton-proton√
collisions at s = 200 GeV with PHENIX
T. Horaguchi∗ and Y. Akiba
Polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC) can provide informationon the spin structure of the nucleon. Direct photon athigh pT is produced mainly by gluon Compton scattering (gq → γq). The measurement of the direct photon
cross section is a testing ground of perturbative QCD,
and it gives us the polarized and unpolarized gluon
distributions in the nucleon.
In PHENIX,1) we have collected data with an integrated luminosity of 0.15 pb−1 for transversely polarized proton-proton collisions with 15% average polarization in the run of 2001–2002 and 0.35 pb−1 forlongitudinallypolarized data in the run of 2003 at√
s = 200 GeV with 30% average polarization.
We analyze the 2001–2002 data of PHENIX to measure the direct photon cross section in pp collisions at
RHIC. We use the electromagnetic calorimeter of central arm spectrometers for the analysis. This calorimeter consists of two subsystems, six sectors of a lead
scintillator calorimeter and two sectors of a lead glass
calorimeter. It is located at a radial distance of approximately 5 m from the beam line. Each of these sectors
covers the pseudorapidity range of |η| < 0.35 and an
azimuthal angle of ∆φ = 22.5◦ . In this analysis, we
use ﬁve lead scintillator calorimeters.
In order to measure the direct photon cross section,
we need to subtract a large background from the decayof π 0 and η (π 0 → γγ, η → γγ). We use the following method in search for the direct photon signal. We
select a high pT photon (pT ≥ 3 GeV/c) in a ﬁducial
volume in the calorimeter. If the reconstructed mass ofthe photon and any other photon in the same event isclose to the mass of π 0 or η, the photons are rejected
as “decay photons”. The remaining photons are direct photon candidates, which include some fractionof π 0 and η decay photons since the rejection method
is not perfect. Therefore the direct photon candidates
are contaminated by the background of such “fake direct photons”. We evaluate the ratio of the “fake direct
photon” relative to the “decay photon” by the detailed
GEANT Monte Carlo simulation of PHENIX. We deﬁne “fake ratio” Rfake as
MC(π 0 ) = NγM C (fake)/NγM C (π 0 ).
Rfake

(1)

Here, NγM C (π 0 ) (NγM C (fake)) is the number of π 0 decay photons in the Monte Carlo simulation for which∗

234

Department of Physics, Tokyo Institute of Technology

the other photon from the same parent π 0 is (not)detected in the calorimeter. The fake ratio for η,MC(η), is deﬁned in a similar way. We can then subRfake
tract the remaining background in the direct photon
candidate byMC(π 0 )Nγ (π 0 )Nγsig = Nγcand − Rfake
MC(η)Nγ (η) − Nγother .
− Rfake(2)Here, Nγsig is the number of direct photon signals,
Nγcand is the number of direct photon candidates inthe data, Nγ (π 0 ) (Nγ (η)) is the number of identiﬁed
π 0 (η) decay photons measured in the data, and Nγotheris the remaining small background due to photons fromhadron decays (ω → γπ 0 , η  → γγ) and mis-identiﬁed
hadrons.
The data analysis based on this method is inprogress. Figure 1 shows the “fake ratio” for π 0 as afunction of pT calculated by the Monte Carlo simulation. We are also working to determine the correction
factors (acceptance, trigger eﬃciency) and to estimate
the systematic uncertainties of the analysis. We expect that we can soon establish the signal of the direct
photon in the data and can determine its cross section.

Fig. 1. “Fake ratio” for π 0 . See the explanations in the
text.

References
1) K. Adcox et al.: Nucl Instrum. Methods Phys. Res. A
499, 469 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Radial flow study from identified hadron spectra in√
Au+Au collisions at sN N = 200 GeV
A. Kiyomichi and T. Chujo, for the PHENIX Collaboration
Heavy ion collisions at relativistic energy oﬀer the
possibility of producing highly compressed strongly interacting matter, which may form the quark gluon
plasma (QGP). Identiﬁed hadron spectroscopy is an
important tool for studying the collision dynamics.
The momentum spectra of pions, kaons, and protons
are sensitive to the dynamical evolution of the systemand carry information about the radial ﬂow velocity
and thermal freeze-out condition.
PHENIX1) is one of the major experiments performed at RHIC for measuring a variety of signals
from heavy-ion collisions. We have measured the transverse momentum spectra for π ± , K ± , p and p at mid√
rapidity in Au+Au collisions at sN N = 200 GeV overa broad momentum range with various centrality selections. The detailed analysis methods and results aredescribed in Ref. 2.
Figure 1 shows the centrality dependence of meantransverse momentum pT  for π ± , K ± , p and p̄. It isfound that pT  for all particle species increases fromthe most peripheral to the central collisions, and also
increases with particle mass. The dependence of pT 
on particle mass suggests the existence of a collectivehydrodynamical expansion.
The radial ﬂow velocity (βT ) and freeze-out temperature (Tf o ) are extracted using a phenomenologicalhydrodynamical model presented in Ref. 3. The invariant cross section can expressed as
 R
 p sinh ρ   m cosh ρ dNTT∝r dr mT I0
K1,
mT dmT
Tf o
Tf o
0


out and mT = p2T + m2 denotes the transverse massof the particle. The transverse velocity proﬁle βr (r) isparameterized as βr (r) = βT (r/R)n , with the surface
velocity βT .
To study the parameter correlations, we make agrid of combinations of Tf o and βT , and perform achi-squared minimization for each particle type. We
use a linear velocity proﬁle (n = 1) and constantparticle density distribution. The ﬁt is performed
simultaneously for all particle species in the range(mT − m0 ) < 1.0 GeV. Since the experimental data
include the decay of resonance, we add the decay ofmesonic (ρ, η, ω, K ∗ , , ,) and baryonic (∆, Λ, Σ, , ,) resonance eﬀects as follows: (1) Generate resonances withthe transverse momentum distribution determined byeach combinations of Tf o and βT . (2) Decay them using Monte Carlo simulation, and obtain π ± , K ± , p andp distribution. (3) Merge all particles, where the particle abundance is calculated with chemical parameters(Tch = 177 MeV, µB = 29 MeV).4)
Figure 2 shows the centrality dependence of thefreeze-out temperature Tf o and radial ﬂow velocity βT .
It is found that Tf o decreases and βT increases from themost peripheral to mid-central collisions, and appears
to saturate in the central collisions. The behavior ofβT is in accordance with a collective expansion picture.

where I0 , K1 are modiﬁed Bessel functions and ρ =tanh−1 βr . Here Tf o is the freeze-out temperature, R is
the maximum radius of the expanding source at freeze-Fig. 2. Freeze-out temperature (top) and average radialflow velocity (bottom) as a function of Npart .

References

Fig. 1. Mean transverse momenta pT  as a function of
Npart for π ± , K ± , p and p̄. The error bars are statisticalerrors. The systematic errors from cuts conditions areshown as shaded boxes on the right for each particle
species.

1) PHENIX Collaboration, K. Adcox et al.: Nucl. Instrum.
Methods Phys. Res. A 499, 469 (2003).
2) PHENIX Collaboration, S. S. Adler et al.: Phys. Rev.
C 69, 034909 (2004).
3) E. Schnedermann, J. Sollfrank, and U. Heinz: Phys.
Rev. C 48, 2462 (1993).
4) P. Braun-Munzinger, D. Magestro, K. Redlich, and J.
Stachel: Phys. Lett. B 518, 41 (2001).

235

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RIKEN Accel. Prog. Rep. 37 (2004)

Single electron measurement in√sN N = 200 GeV Au+Au collisions

T. Hachiya∗ and Y. Akiba
Heavy quarks (charm and beauty) are one of theimportant probes of the hot and dense matter createdin high energy heavy ion collisions. They are mainly
produced via gluon-gluon fusions in the initial stageof the collisions. Therefore, the yield of charm andbeauty is sensitive to the initial gluon density.1) In central Au+Au collisions at RHIC, high pT particles arestrongly suppressed due to energy loss in the dense
matter created in the collision. It is predicted thatthe charm quarks suﬀer smaller energy loss than lightquarks due to the “dead cone” eﬀect.2) This eﬀect canbe studied from the transverse momentum (pT ) distribution of charmed particles. In addition, the open
charm yield is the baseline of the J/ψ suppression3)
which is one of the expected signatures of the deconﬁnement of quarks and gluons.
The measurement of single electrons at high pT resulting from the semi-leptonic decays of heavy quarks(D → eX and B → eX) is a useful way to study theheavy ﬂavor production. We have studied the single√
electron production in Au+Au collisions at sN N =200 GeV. The data was recorded by the PHENIX eastarm spectrometer during the 2001 run period. The
PHENIX detector is described in detail elsewhere.4) A
set of beam-beam counters and zero degree calorimeters provides our minimum bias triggers and measures
its collision vertex positions. The charged particle
tracks are reconstructed with the drift chamber andthe pad chamber which covers |η| < 0.35 in pseudorapidity and 90 degrees in azimuthal angle. Electron
identiﬁcation is carried out by using the ring imaging
Cherenkov detector and the electromagnetic calorimeter. The raw spectrum is corrected for the geometricalacceptance and the reconstruction and identiﬁcationeﬃciencies determined by a detailed GEANT simulation.
The inclusive electron spectrum can be decomposed
into contributions from non-photonic sources (charmand beauty decays) and from photonic sources (Dalitz
decays of neutral mesons and photon conversions). In
order to separate these contributions experimentally,
we took a special data with a brass photon converter
placed around the beam pipe. The converter increases
electrons only from photonic sources by a ﬁxed factor which is determined by the radiation length of theconverter (1.7%). We analyzed 2.2 M events of converter data and 2.5 M events of no converter data. We
also simulated the eﬀect of the photon converter using
a detailed GEANT simulation of the PHENIX detector. By the comparison of the real and simulated datawith and without the converter, we extracted the non∗

236

Hiroshima University

photonic component of the electron spectrum.
Figure 1 shows the invariant pT spectrum of electrons from non-photonic sources in minimum bias√
Au+Au collisions at sN N = 200 GeV. Here, only
the statistical uncertainty is shown. The backgroundfrom kaon decays and di-electron decays of light vector
mesons (ρ, ω, φ) are also evaluated using a GEANT
simulation and a hadron decay generator, respectively.
Those contributions are small, and they are subtracted
from the non-photonic electron spectrum.
The dash and dot-dash lines in the Fig. 1 show thecontributions from charm and beauty decays calculated by PYTHIA,5) and the solid line is the combination of the two contributions. The PYTHIA calculation is scaled from pp to Au+Au collisions using thenumber of binary collisions determined by a Glaubermodel. The data is consistent with the PYTHIA charmand beauty decays. This suggests that heavy quarks
suﬀer smaller energy loss in the dense matter than lightquarks.
A preliminary result of this analysis, with large systematic uncertainties, was presented at the QM02 conference. The present analysis has signiﬁcantly reduced
the systematic uncertainties. The centrality dependence of the electron yield from non-photonic sources
and the estimation of the systematic uncertainties arein progress. We expect to publish the ﬁnal result of
the analysis soon.

Fig. 1. Invariant pT spectrum of electrons from nonphotonic sources in minimum bias Au+Au collisions at√
sN N = 200 GeV compared with the expected contributions from semi-leptonic decays of charm and beauty
calculated by PYTHIA.

References
1) B. Muller and X. N. Wang: Phys. Rev. Lett. 68, 2437
(1992).
2) Y. L. Dokshitzer and D. E. Kharzeev: Phys. Lett. B
519, 199 (2001).
3) T. Matsui and H. Satz: Phys. Lett. B 178, 416 (1986).
4) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res. A
499, 469 (2003).
5) T. Sjostrand: Comput. Phys. Commun. 82, 74 (1994).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Particle composition at high pT in Au+Au collisions√
at sN N = 200 GeV
T. Chujo and A. Kiyomichi
High pT hadron production originating in the fragmentation of partons with a large momentum transfer
is a sensitive probe of the hottest and densest stage inthe relativistic heavy-ion collisions. One of the mostsigniﬁcant results from the Relativistic Heavy Ion Collider (RHIC) runs is that the high pT hadron yields arelargely suppressed in central Au+Au collisions withrespect to the underlying number of nucleon-nucleon
collisions (Ncoll ).1) It is also found that protons andanti-protons yields near 2 GeV/c in central Au+Au
collisions are comparable to that of pions,2) which suggests that a signiﬁcant fraction of all particle yields isp and p at the intermediate pT (2–5 GeV/c) in central
Au+Au collisions. We report here the results of p andp yields and their scaling properties in Au+Au colli√
sions at sN N = 200 GeV measured by the PHENIX
experiment at RHIC.
Figure 1 shows the p/π and p/π ratios as a functionof pT measured at mid-rapidity in diﬀerent collision√centrality selections in Au+Au at sN N = 200 GeV.
We observed that there is a strong centrality dependence in p/π and p/π ratios at the intermediate pT region, i.e., the ratios in central events are a factor of ∼3larger than in peripheral events. The peripheral data
at pT > 3 GeV/c agree well with the ratios observed inp + p collisions at lower energies and the results fromgluon and quark jet fragmentation. In order to investigate the scaling behavior and yield suppression eﬀect
for p and p, the Ncoll scaled central to peripheral yieldratios (RCP ) for protons is used. As shown in Fig. 2, p
and p are not suppressed at pT = 1.5–4.5 GeV/c while
there is a factor of 2–3 suppression for π 0 . We also observe that h/π 0 ratio in central events is enhanced by

Fig. 2. Nuclear modification factor RCP for (p+p)/2 (filled
circles) and π 0 .3,4) Dashed and dotted lines indicate
Ncoll and Npart (number of participant nucleons) scaling; the shaded bars show the systematic errors on thesequantities.

as much as 50% above the p+p value3) and this relative
baryon enhancement is limited to pT < 5–6 GeV/c.
It is interesting why the suppression for p and p isabsent in central Au+Au collisions. Recently the observed abundance of protons yields relative to pions incentral collisions has been attributed to the recombination of quarks, rather than fragmentation.5) In thismodel, quark recombination for p and p is eﬀective up
to pT  5 GeV above which fragmentation dominates
for all particle species. Another explanation of the observed large baryon content invokes a hydrodynamical
radial ﬂow and the jet quenching of hard jet.6) Boththeoretical models agree with data qualitatively andpredict that the baryon/meson enhancement is limited
to pT <∼ 5 GeV/c.
References

Fig. 1. Centrality dependence of p/π and p/π ratios in√
Au+Au collisions at sN N = 200 GeV.3,4)

1) PHENIX Collaboration, K. Adcox et al.: Phys. Rev.
Lett. 88, 022301 (2002).
2) PHENIX Collaboration, K. Adcox et al.: Phys. Rev.
Lett. 88, 242301 (2002).
3) PHENIX Collaboration, S. S. Adler et al.: Phys. Rev.
Lett. 91, 172301 (2003).
4) PHENIX Collaboration, S. S. Adler et al.: Phys. Rev.
C 69, 034909 (2004).
5) R. C. Hwa et al.: Phys. Rev. C 67, 034902 (2003); R. J.
Fries et al.: nucl-th/0301087; V. Greco et al.: nucl-th/
0301093.
6) T. Hirano and Y. Nara: nucl-th/0307015.

237

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RIKEN Accel. Prog. Rep. 37 (2004)

π 0 event anisotropy in√sN N = 200 GeV Au+Au collisions

M. Kaneta and H. Torii, for the PHENIX Collaboration
Event anisotropy analysis is a powerful tool forstudying the properties of the early stage of high energy heavy ion collisions. Because it provides information on collision dynamics in the early stage after heavy
ion collisions. The recent results of event anisotropy
analysis suggest a ﬁnite v2 (second-harmonic coeﬃcient of Fourier expansion of azimuthal distributions)
up to 6 GeV/c of transverse momentum (pT ). Due tothe particle identiﬁcation method, the measurement ofcharged π, K, and p has a limit of pT (< 4 GeV/c, thusfar).1) On the other hand, π 0 measurement using an
Electro-Magnetic Calorimeter (EMC) can reach a very
high pT (> 10 GeV/c).2,3) The PHENIX is an uniqueexperiment to measure high transverse momentum π 0in relativistic heavy ion collisions at RHIC. We willreport the results of π 0 v2 analysis as a function of cen√
trality and pT from sN N = 200 GeV Au+Au collisions data.
Event anisotropy analysis involves the applicationof the Fourier expansion of particle distributions toanalyze the event anisotropy of azimuthal distributionsof particles. The distributions are described by,
E

1
d2 N
dN 3
=
3
d p
2π pT dpT dy
∞2vnm cos[n(φ − Φr )] ,× 1+

where C is a constant. Since the reaction plane is
distributed uniformly, the eﬃciency of the detector is
normalized. Hence, we can ﬁt the number of particles
as a function of φ − Φr by Eq. (2) to obtain v2m .
The π 0 v2 analysis was performed in the following
steps: (1) Invariant mass calculation from two photons measured by EMC,2,3) (2) subtracting the combinatorial background by the event mixing method, (3)counting the number of π 0 as a function of φ − Φr foreach centrality, pT bins, (4) the distribution is ﬁtted
using Eq. (2), and (5) correct v2m by resolution to obtain v2 . Figure 1 shows π 0 v2 as a function of pT from√the minimum bias data in sN N = 200 GeV Au+Au
collisions. The limit of the pT range has been deﬁned
by statistics thus far. On the other hand, a low pT(< 1 GeV/c) has much hadron contamination in EMC.
Therefore we analyzed π 0 in pT > 1 GeV/c.
The result shown in Fig. 1 is the ﬁrst measument of
an identiﬁed hadron up to pT = 10 GeV/c at RHIC.
π 0 v2 increases with pT and then saturates at pT ∼3 GeV/c. Also it has a non-zero value up to pT =8 GeV/c. PHENIX has the results of the identiﬁed
charged pion v2 .5) π 0 v2 is consistent with the charged
pion results.

(1)

n=1

where y is the rapidity and φ is the azimuthal angleof the particle, Φr is the reaction plane and vnm is thenth order of the Fourier coeﬃcient measured by detectors. The reaction plane is deﬁned using a Beam-Beamcounter (BBC) and has a resolution due to granularity of the detector. Therefore, the vnm is smeared by
the uncertainty of the reaction plane deﬁnition. The
method of vnm correction we adopted is shown in Ref. 4
and real vn will be corrected by reaction plane resolution (vn = vnm /σn , where σn is the resolution for thenth harmonic). Here we will focus on the ellipticity
of event anisotropy. Event anisotropy is rotation sysmetric to the zero rapidity axis because of momentum
conservation. Therfore the odd number of the orderof harmonics will be canceled when we add positive
and negative rapidity regions. Additionally, assuming
a higher order of harmonics is negligible, Eq. (1) becomes
1d2 N 
dN 3
1 + 2v2m cos[2(φ − Φr )]
E 3 =
d p
2π pT dpT dy
(2)= C 1 + 2v2m cos[2(φ − Φr )] ,238

Fig. 1. PHENIX preliminary result of π 0 v2 as a function ofpT for minimum bias data (92% of geometrical crosssec√
tion of sN N = 200 GeV Au+Au collisions). The error
bar shows statistical error and the systematic errors areshown by gray box.

References
1) K. Adcox et al.: nucl-ex/0307010.
2) S. S. Adler et al.: hepl-ex/0304038.
3) S. S. Adler et al.: Phys. Rev. Lett. 91, 072301 (2003).
4) A. M. Poskanzer and S. A. Voloshin: Phys. Rev. C 58,
1671 (1998).
5) S. S. Adler et al.: nucl-ex/0305013.

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RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of fluctuations in event-by-event Nch − Nγ balance
T. Nakamura∗ and K. Homma,∗ for the PHENIX Collaboration
The anomalous event-by-event ﬂuctuation of thebalance between the number of produced charged andneutral pions (Nπ± , Nπ0 ) is one of the possible signatures of the chiral phase transition followed by the creation of disoriented chiral condensates1) in high energy
heavy-ion collisions.
√
In Au+Au collisions at sN N = 200 GeV in the
PHENIX2) experiment at RHIC, we investigate thebalance between the number of charged particles andphotons (Nch , Nγ ) as a function of subdivided phasespace x ≡ (η/nη , φ/nφ ), where nη and nφ are the numbers of bins that divide the total phase space η and φ.
The balance is deﬁned as
B(x) ≡ Nπ± (x) − 2Nπ0 (x) ≈ Nch (x) − Nγ (x), (1)where Nπ± and Nπ0 are approximated to be Nch andNγ in this analysis, since we assume that most statistically dominant particles are pions. Then we introduce
δB(x), which is deﬁned as a diﬀerential balance normalized to the expected standard deviation σB(x) of
the balance at the subdivided phase space size.
δB(x) ≡

B(x + dx) − B(x),σB(x)

B(x) ≡ Nch (x) − Nγ (x),
σB(x) ≡ δNch (x)2 + δNγ (x)2 ,

(2)
(3)
(4)

where, B(x + dx) − B(x) corresponds to a diﬀerence
between two neighboring bins. The variance aroundthe expected values Nch (x) and Nγ (x) is expressedby the value of δB(x). Then ﬁnally our observable isdeﬁned as;δBmax ≡ max |δB(x)|.

(5)

where a maximum |δB(x)| is selected among all available phase spaces in all resolution levels per event.
Finding δBmax allows us to detect the most anomalous domain in a given event and to determine how
anomalous the domain is compared to baseline ﬂuctuations. Figure 1 shows δBmax distributions for eachcentrality and minimum bias events that correspondto 92.2% of the Au+Au inelastic cross section. The
ﬁlled distributions indicate the δBmax distributions ofbinomial samples produced by hit map of real charged
tracks and photon clusters to reﬂect detector conditions. We introduced thease binomial distributions as
a baseline ﬂuctuations and established the correspondence between probabilities to exclude the binomial
distribution and values of δBmax . Figure 2 shows thefraction of events above the 5% signiﬁcance level to∗

Hiroshima University

Fig. 1. Maximum diﬀerential balance (δBmax ) distributions for each centrality (solid) and binomial samples generated with exactly the same multiplicity sets
(Nch , Nγ ) (ﬁlled). The binomial distribution was normalized to the number of events in the real data.

Fig. 2. Npart dependence of the fraction of events above
the event-by-event 5% signiﬁcance level from the total
number of MB events analyzed, which is integrated in
all resolution levels after subtracting of binomial points.
The systematic errors from ithe selection criterion of
charge tracks and photon clusters and ambiguities ofthe limit value as 5% signiﬁcance level are shown as
shaded band.

exclude the binomial ﬂuctuations with respect to minimum bias events as a function of the number of participants (Npart ). It is shown that the fraction increases as
Npart increases. The analysis to investigate the sourcesof the ﬂuctuations is in progress by taking the eﬀects ofjets, ﬂow and Bose-Einstein correlation into account.
References
1) K. Rajagopal and F. Wilczek: Nucl. Phys. B 399, 395(1993).
2) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res. A
499, 469 (2003).

239

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RIKEN Accel. Prog. Rep. 37 (2004)

Search for non-hadronic sources of photons in Au+Au collisions at√
sN N = 200 GeV at RHIC-PHENIX
T. Sakaguchi,∗1 X. Camard,∗2 G. David,∗3 D. d’Enterria,∗4 H. Hamagaki,∗1 S. Kametani,∗1 K. Kato,∗5
T. Matsumoto,∗1 S. Mioduszewski,∗3 K. Oyama,∗1 K. Ozawa,∗1 M. L. Purschke,∗3 M. Tamai,∗5
H. Torii, and C. Woody,∗3 for the PHENIX Collaboration
Thermal photons have long been considered to be
an excellent probe of the early stages of the relativistic heavy ion collisions because they have a long mean
free path compared to the size of the nuclear volume
involved in the collisions. To extract the thermal photons, γ’s from known hadronic sources must be subtracted. Of the hadronic sources, π 0 and η are themajor contributors. The sum of the other sources is∼4% of the total at around pT of 2 GeV/c. Thus, π 0and η contributions must be correctly evaluated andsubtracted from measured inclusive photons.
PHENIX1) has succeeded in measuring π 0 ’s in√
Au+Au collisions at sN N = 200 GeV using theelectro-magnetic calorimeter (EMCal)2) for events
classiﬁed in accordance with the impact parameter ofthe collision. 0% corresponds to an impact parameter of 0, and 100% to that of the diameter of a gold
ion. The transverse momentum spectra of π 0 havebeen published,3) and those for central (0–10%) andperipheral (60–80%) events are used for this analysis.
The spectra are ﬁtted with a power-law function ofA(1 + pT /p0 )−n , where A, p0 and n are the ﬁtting
parameters. The systematic error due to ﬁtting wasestimated by moving data points up and/or down by
pT -correlated and pT -uncorrelated errors, ﬁtting withpower-law function, and comparing with the originalﬁt.
The mT scaled power-law ﬁt to π 0 is used as a spectrum of η. The function is similar to the one for π 0 except that pT is substituted by (p2T − m2π0 + m2η )1/2 , andA by 0.55 × A according to the result from a PYTHIA
calculation.4) The systematic uncertainty of the factor
is 50%. The total systematic error on the sum of theyield of π 0 and η is estimated to be 17–22%.
The fast Monte Carlo simulation5) was used to generate γ’s from π 0 and η, to accumulate all γ’s thatare in the acceptance, and to smear their energies
according to the intrinsic resolution of the EMCal.
The photon identiﬁcation and clustering eﬃciency aswell as the background contribution are evaluated using HIJING simulation events6) processed through a
GEANT-based simulation code. The measured EMCal
cluster energy distributions are corrected using the ef∗1
∗2
∗3
∗4
∗5

240

Center for Nuclear Study, University of Tokyo
Groupe Photons, SUBATECH, France
Brookhaven National Laboratory, USA
Columbia University, USA
Advanced Research Institute for Science and Engineering,
Waseda University

ﬁciency and the estimate of the background to obtainthe γ spectrum.
Figure 1 shows the ratios of the measured γ distributions to those calculated for both peripheral (60–√80%) and central (0–10%) events at sN N = 200 GeV.
The gray bands show the systematic errors originating from π 0 measurement, η/π 0 ratio, photon identiﬁcation and clustering eﬃciency, and the estimate of
the background contributions. In this plot, the pT correlated systematic errors are shown as bands, andthe quadrature sum of pT -uncorrelated and statisticalerrors are shown as error bars. The measured distributions are consistent with the calculated distributions
for both peripheral and central events within the current statistical and systematic errors.

Fig. 1. Ratios of measured and calculated γ distributions
for peripheral (upper) and central (lower) events.

References
1) PHENIX Collaboration: Nucl. Instrum. Methods Phys.
Res. A 499, 469 (2003).
2) L. Aphecetche et al.: Nucl. Instrum. Methods Phys.
Res. A 499, 521 (2003).
3) S. S. Adler et al.: Phys. Rev. Lett. 91, 072301 (2003).
4) T. Sjostrand: Comput. Phys. Commun. 82, 74 (1994).
5) T. Sakaguchi et al.: CNS-REP-36, 35 (2001).
6) X.-N. Wang and M. Gyulassy: Phys. Rev. D 44, 3501
(1991).

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RIKEN Accel. Prog. Rep. 37 (2004)

AGS snake
M. Okamura and J. Takano∗
A new normal-conducting helical snake magnet for
the AGS was designed and fabricated successfully andis being shipped to BNL.
The AGS synchrotron at BNL introduced a partial
snake, which helps to overcome the imperfection resonances that appear during the acceleration of polarized
protons. The existing partial snake is a solenoid magnet and its ﬁeld rises at the same rate as that of the
AGS main magnet. However, the longitudinal component of the solenoidal partial snake introduces linear
coupling of the transverse coordinates of the beam.
This linear coupling causes additional intrinsic resonances which aﬀect the ﬁnal polarization of the beam.
To achieve high polarization in the RHIC which follows the AGS, those intrinsic overcoming resonancesin the AGS is very important. In order to reduce thecoupling caused by the solenoid magnet, an alternative partial snake called helical dipole magnet has been
proposed. Unlike the helical dipole magnet used in
RHIC,1) each of which consists of four 2.4-m-long superconducting magnets, the AGS partial helical snake
is simply a single helical magnet which can be accommodated in a short straight line of the AGS.2,3)
Figure 1 shows the AGS helical dipole magnet’s input to OPERA-3D (TOSCA).a) Figure 2 shows thecoil shape of this magnet.
We adopted a square-shaped conductor of 14.5 mm×14.5 mm in cross section, with a square hollow water
passage of 10 mm × 10 mm. The coil has 10 turns (azimuthal direction) and 7 layers (radial direction). Total operational current is 187000 AT and the maximum
ﬁeld strength is 1.5 T. To meet the requirements fromthe AGS machine group in order to reduce the temperature rise of the cooling water, we employed parallelpancake winding. This doubles the number of water
passages, although the fabrication of the coil would
become complicated.

Fig. 2. Double-pitch structure of the helical coil.

In the case of the RHIC, each snake consists offour superconducting helical dipole magnets. All thesemagnets are mechanically identical but the operational
ﬁeld strengths are varied, such as 1.2 T, −4 T, 4 T,
−1.2 T. The AGS helical single magnet, on the other
hand, consists of two types of patterns as shown in
Fig. 2: one slow pitch section and two rapid pitch sections in a magnet. Figure 3 shows the cross sections ofFig. 3. Cross sections of the helical coil.

Fig. 1. Model of the helical magnet on OPERA-3D.
∗a)Tokyo Institute of Technology
Vector Fields Limited, Oxford.

Fig. 4. Beam trajectory of z vs. x, y after optimization.

241

the coil at z = constant plane in diﬀerent pitches. The
beam shift and beam deﬂection angle can be adjusted
by choosing adequate pitch values and ratios of the twopatterns. Although it is rather diﬃcult to constructthis complicated structure in a single magnet, the sizeand cost of the snake were minimized.
To minimize the beam shift and deﬂection angle, thepitches and length of each section are carefully selectedusing OPERA-3D/TOSCA. Beam trajectories after
optimization are shown in Fig. 4.
Figure 5 shows the coil alignment process in the fabrication of the helical dipole magnet. Mechanical design work and fabrication were carried out by Takano
Original Magnet Co. This magnet was completed at
the end of October, 2003.
We plan to measure the ﬁeld quality of the magnet at BNL in collaboration with the superconducting
magnet division before installation to the AGS.
References

Fig. 5. AGS helical dipole magnet under construction.

2421) W. W. MacKay et al.: AGS/RHIC/SN-80/BNL (1999).
2) M. Okamura et al.: Proc. EPAC 2002, Paris, France,
2002-6 (The European Physical Society, 2002) p. 2421.
3) M. Okamura et al.: Proc. EPAC 2000, Vienna, Austria,
2000-6 (Austrian Academy of Sciences Press, 2000)
p. 2126.

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RIKEN Accel. Prog. Rep. 37 (2004)

Detection of very small angle proton-proton elastic scattering for
absolute polarimetry at RHIC
H. Okada,∗1 A. Bravar,∗2 G. Bunce,∗2 K. Imai,∗1 O. Jinnouchi, K. Kurita,∗3 Y. I. Makdisi,∗2 and N. Saito∗1
The precision measurement of beam polarization isa crucial part of the RHIC spin program. For example,
two-spin longitudinal asymmetry is deﬁned as ALL =1
εLL , where εLL is the measured (raw) asymmetry2
Pbeam
in a particular process for the parallel and antiparallel
spin conﬁgurations of polarized proton beams. A currently obtained accuracy of ∆Pbeam /Pbeam ∼ 30%1)
would contribute to the uncertainty of asymmetry,∆ALL /ALL , by ∼60%. Since the error of asymmetry would be directly reﬂected on the uncertainty ofthe physical observables which we are trying to extract, e.g., gluon polarization, it is very important to
reduce the uncertainty in the beam polarization. We
are now constructing the RHIC Absolute Polarimeterto achieve the best possible determination of the beampolarization.
We have chosen pp elastic scattering for the RHIC
Absolute Polarimeter in the very small |t| region of
0.001–0.02 GeV2 . The reason why we have chosen pp
elastic scattering is that we can simply transfer the target polarization Ptarget to the beam polarization Pbeam
by comparing beam spin asymmetry with target spin
asymmetry. By using a polarized gas jet target anda polarized beam simultaneously, the beam polarization can be determined at its best possible precision(∆Pbeam /Pbeam ≈ ∆Ptarget /Ptarget ) with the suﬃcientnumber of pp elastic events. We also need a high target
polarization to minimize systematic errors and we havechosen the Polarized Gas Jet Target. We can expect
Ptarget to be more than 90% with ∆Ptarget /Ptarget < 2–3%. This high (“statistical” not needed) accuracy willallow us to measure the absolute beam polarization to∆ALL /ALL ∼ (“10% in ’04 and a ﬁnal goal of” notneeded) 6%.
We also want to extend the precision measurement
to smaller |t| region. Figure 1 shows the theoretical prediction of AN in the CNI (Coulomb Nuclear
Interference) region as a function of |t|. AN for pp
elastic scattering is expected to reach ∼4.5% at |t| ≈3 × 10−3 GeV2 and to change dynamically in a verysmall |t| region, 0.001–0.006 GeV2 . However, there has
been no measurement yet, since it is extremely diﬃcult
to identify elastic scattering in a very small angle. Figure 2 shows the correlation between proton recoil angle
and |t|. Line (a) corresponds to the pp elastic scattering kinetics and lines (b) and (c) correspond to kinematical boundaries for the pion-associated production
and resonance production, respectively. The shaded
∗1
∗2
∗3

Department of Physics, Kyoto University
Brookhaven National Laboratory, USA
Department of Physics, Rikkyo University

Fig. 1. Theoretical prediction for AN as a function of |t|.

Fig. 2. Kinetic limit of the recoil proton angle vs. |t|. Line(a); pp elastic. Line (b); threshold of pp → (p + π)p.
Line (c); threshold of pp → N (1440)p. Shaded region;
detectable region for Si detectors.

region shows the detectable area of our Si detector fora recoil proton. The ﬁgure shows that our data could
be signiﬁcantly contaminated by pion-associated production. We expect that we should be able to overcome
this problem by measuring the correlation between |t|and proton recoil angle.
As shown in Fig. 2, the main physics background isan inelastic event, pp → (pπ) p. The recoil angle of thisevent is quite diﬀerent from that of an elastic event:
2
MX
− m2p
elastic
elastic
 + sin θR> sin θR.
2Pbeam |t| 2− m2p = (mp + mπ )2 − m2p
If MX

Xp
=
sin θR243

> 2pbeam|t|∆θR ,we can remove inelastic events by reconstructing
MX (|t|, θR ), and the desired angle resolution is∼3 mrad. Here, mp and mπ are the masses of a protonand pion, respectively. Pbeam is the momentum of thebeam.
There are two methods of determining |t|. One isto measure the kinetic energy of the recoil proton, andthe other is to measure the TOF of the recoil proton. In the ﬁrst method, our goal in the resolution∆|t| < 1.0 × 10−4 GeV2 is reachable with the energy
resolution of ∆Tkin ∼ 50 keV, which is already established with the Si detector to be used for this measurement. In determining |t| from TOF, TOF resolution
is dominated by bunch length (= 5 ns), since the time
resolution of the Si detector is measured to be 2 ns.
The typical TOF is ∼80 ns in |t| ∼ 0.001 GeV2 . The
time resolution of 5 ns leads to ∆|t| ≈ 1.3×10−4 GeV2 ,which is suﬃcient for our measurement.

244

The resolution of the recoil angle detection is dominated by the strip width of the Si detector. The strip
width is 1 mm and the distance between the beam axis
and Si detectors is ∼0.8 m. The angle separation between the elastic and inelastic events would be in theorder of 0.01 rad, and we have a suﬃcient resolution.
The Jet Target2) has already been checked its highpolarization at one of the collision points at RHIC, andSi detectors will be installed in February – March, 2004
for the pp run in April. We will fully commission thesystem in this coming run and we will obtain AN very
precisely in the next run, when we expect to have avery long pp run.
References
1) O. Jinnouchi et al.: RIKEN Accel. Prog. Rep. 36, 237(2003).
2) A. Zelenski: Proc. 10th Workshop on High Energy Spin
Physics (SPIN2003), Dubna, Russia, 2003-9, to be published.

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RIKEN Accel. Prog. Rep. 37 (2004)

Polarimetry in RHIC and AGS from Run-03
O. Jinnouchi, I. G. Alekseev,∗1 A. Bravar,∗2 G. Bunce,∗2 S. Dhawan,∗3 H. Huang,∗2 V. Hughes,∗3 G. Igo,∗4
K. Kurita,∗5 Z. Li,∗2 W. Lozowski,∗6 W. W. Mackay,∗2 S. Rescia,∗2 T. Roser,∗2 N. Saito,∗7 H. Spinka,∗8
D. N. Svirida,∗1 D. Underwood,∗8 C. Whitten,∗4 and J. Wood∗4
In the previous polarized proton run in 2001/2
at the Relativistic Heavy Ion Collider (RHIC), two
RHIC polarimeters were successfully operated.1,2)
They use the proton-Carbon elastic scattering process in a very small momentum transfer region 0.005 <−t < 0.05 (GeV/c)2 called Coulomb Nuclear Interference (CNI).
The low polarization at the RHIC storage energy(∼11% in blue and ∼16% in yellow on average) was ofmaximum concern in RHIC-Spin Run-02. The maincause was known to be due to AGS acceleration. In
Run-03, a new polarimeter using the same pC CNI
process was installed in AGS internally to provide fast
feedback for the diagnostics in polarized proton acceleration. The setup was similar to that installed in
RHIC polarimeters except, 1) The Carbon target was
wider, ∼600 µm, to gain a higher hit rate, 2) the distance between the target and the detector was set to
be longer (25 cm) considering the longer bunch spacein AGS, 3) only two silicon strip detectors (SSDs), instead of six were installed at 90-degree locations. The
data acquisition uses the waveform digitizer module as
in RHIC. The recoil Carbon events were stored on
board memory and read out for each AGS cycle.
For the ﬁrst time, the polarization measurements
during energy ramping were carried out in AGS. The
measured raw asymmetry is shown in Fig. 1 as a function of Gγ where G is the anomalous magnetic momentcoeﬃcient of proton and γ is a Lorentz factor. Due tothe solenoidal partial snake in AGS, the beam spin direction ﬂips at imperfection resonance points, whereGγ equals integer values. Furthermore, at four strong
intrinsic resonances (i.e. Gγ = 12 + ν, 36 − ν, 48 − νand 36 + ν, where ν is the vertical betatron tune in
AGS, ν = 8.7), the depolarization is overcome by using an ac dipole (spin ﬂipper), and changes in the spin
direction are also observed.
In addition to the nominal measurements with AGS
extraction energy at 24.3 GeV/c (Gγ = 46.5), measurements were performed at the intermediate energies such as, Gγ = 7.5, 12.5, 18.5 and 41.5. These
data were collected with another internal inelastic pC
polarimeter (E880) for the normalization. The data
indicates a rapid change in the analyzing power AN in
∗1
∗2
∗3
∗4
∗5
∗6
∗7
∗8

Institute for Theoretical and Experimental Physics, Russia
Brookhaven National Laboratory, USA
Yale University, USA
University of California, Los Angeles, USA
Rikkyo University
Indiana University Cyclotron Facility, USA
Kyoto University
Argonne National Laboratory, USA

Fig. 1. A raw asymmetry measured with a new AGS CNI
polarimeter as a function of beam energy (equivalent toGγ) after averaging over many ramps for more than five
hours. The deviation between the solid curve (spin simulation without assuming the analyzing power change)
and the data points indicates that the analyzing power
is not constant.

the low beam momentum regime below 10 GeV/c, andshowed a quite diﬀerent −t dependence compared to
the nominal CNI shape. The diﬀerence of the −t dependence of AN showed a rather asymptotic behavior
in momentum above 20 GeV/c. This is consistent withthe result from other measurement (E9503) ) with the
AGS 21.7 GeV/c polarized proton. The dependence
is also conﬁrmed at the RHIC energies of 24.3 GeV
and 100 GeV, where similar results in both rings wereshown.
Polarization in RHIC was signiﬁcantly improved
from the last run. 29% and 25% in average for Blueand Yellow rings at storage energy were established.
Nevertheless, a large polarization drop was seen fromthe injection energy to storage energy. There were attempts made to measure the polarization along withthe energy ramp in RHIC as well, to determine the depolarization point during the acceleration. Because of
the lack of statistics due to technical reasons, the result
was not conclusive. We will resume this measurementin the next run.
References
1) O. Jinnouchi et al.: RIKEN Accel. Prog. Rep. 36, 237(2003).
2) O. Jinnouchi et al.: AIP Conf. Proc. 675, 817 (2003).
3) J. Tojo et al.: Phys. Rev. Lett. 89, 052302 (2002).

245

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RIKEN Accel. Prog. Rep. 37 (2004)

PHENIX local polarimeter, RUN III
A. Deshpande, B. Fox, Y. Fukao,∗ Y. Goto, K. Tanida, M. Togawa,∗ and N. Saito,∗
for the PHENIX Collaboration
The spin physics program for double longitudinal
spin measurements at the Relativistic Heavy Ion Collider (RHIC) began in 2002-3, in RUN III of the collider operation. For the ﬁrst time polarized protons
collided in PHENIX experimental area with longitudinal polarization.1) The stable direction of the polarized
protons in the collider ring is vertical. The spin rotator magnets located around the experimental area aresupposed to rotate the spin vector by 90 degrees to enable longitudinal collisions in the PHENIX Interaction
Region (IR). The phenix local polarimeter was motivated by the need to conﬁrm that the spin orientationin the IR during the run was indeed longitudinal.
A single transverse spin analyzing power in the neutron production was discovered in 2001-2 in a test
setup at IP12 in RHIC.2) This surprisingly large analyzing power was discovered using a calorimeter located 18 meters from the collision point between thetwo beam pipes. This is the same location in which
RHIC Zero Degree Calorimeters (ZDCs) are located.
Each of the RHIC ZDCs consist of 3 modules oftungsten-ﬁber hadronic calorimeters. The total radiation length of the 3 ZDCs is X0 ∼ 150 and λI ∼ 5.1.
They have no transverse segmentation. Two layers(horizontal and vertical) of plastic scintillators (Shower
Max Detectors or SMDs) were inserted between the 1st& the 2nd ZDC module to locate the position of theneutron hits on the surface of the ﬁrst ZDC. Each of
the SMD element was 1.5 cm wide. There were 7 vertical and 8 horizontal elements of these hodoscopes readby a M16 Hamamatsu photo multiplier tube.
Photons do not make it to the end of the ﬁrst ZDC
module and hardly give a signal on the SMDs. Neutrons traversing through the ZDC create electro magnetic shower which is detected by the SMDs. The energy deposits on the individual (1.5 cm wide) units of
the SMD can be used to arrive at the position of theneutron hit on the face of the ZDC. Based on thelocation of the hit, left/right and up/down asymmetries were formed. We plot the φ position of the hit
along the azimuthal angle. The maxima at φ = ±π/2
indicate transverse vertical polarization, a maxima at
φ = 0 indicate a horizontal polarization, and no asymmetry over the entire range indicates that the polarization vector is longitudinal.
Figures 1 and 2 show the transverse spin asymmetries measured by the SMD-ZDC system calculated using position of the neutrons hit in the front of theﬁrst ZDC. In Fig. 1 the spin rotator magnets wereturned oﬀ, i.e. the spin orientation of the proton was∗

246

Physics Department, Kyoto University

Fig. 1. The asymmetry divided by the polarization measured by PHENIX local polarimeter for transverse polarization (spin rotator magnets currents oﬀ).

Fig. 2. The asymmetry divided by the polarization when
the beams were longitudinally polarized.

transverse and vertical. When the spin rotators wereturned on ﬁrst we found that results consistent withradial polarization in PHENIX. Apparently, the current leads of the spin rotator magnets were switched,
as such the spin rotators turned the tranverse orientation of the proton bems to transverse (radial) in the
IR. Discovering this very quickly and decisively was
crucial to the entire RHIC Spin run last year and evenfor future. After correcting for this mistake, we obtained Fig. 2 in which we show the ﬁnal current values
at which no asymmetries were seen, while RHIC CNI
polarimeter was consistently measuring ∼35% polarization.
After the run the above asymmetries were calculated for all good ﬁlls used in the ﬁnal data analysis.1)
In blue the beam polarization projection over the en+0.000
tire RUN III was PL /P = 0.993+0.005−0.014 −0.090 while in+0.013 +0.010
the yellow ring it was PL /P = 0.974−0.032 −0.090 , bothconsistent with 1.0. Further, tracking of the spin vector precession in the magnets around the experimental
area conﬁrms that the spin orientation of the protons
in the bunches were indeed understood.
References
1) A. Bazilevsky et al.: RIKEN Accel. Prog. Rep. 37, 229(2004).
2) Y. Fukao et al.: AIP Conf. Proc. 675, 584 (2003).

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RIKEN Accel. Prog. Rep. 37 (2004)

Dead layer thickness measurement of Si detectors for
the RHIC pC CNI polarimeter
S. Saito,∗ H. Ueno,∗ O. Jinnouchi, and K. Kurita∗
We measured the dead layer thickness of the Si detector used for the RHIC pC CNI polarimeter.1) We
used the Si detector to measure recoil carbons fromproton-carbon Coulomb nuclear interference (CNI) reactions and determined the polarization of proton
beams. The energy loss in the dead layer was significant, because recoil carbons of interest had very low
energy values of 200 to 300 keV.
The Si detector was an implantation type. The detector sensitive volume was 10 mm × 25 mm × 0.4 mm
and was segmented into 12 strips which were 10 mmlong and 2 mm wide. From the experimental data of
the RHIC polarimeter, dead layer thickness was estimated to be approximately 40 µg/cm2 , which we considered as the major source of our systematic error.
To conﬁrm this result, we carried out a direct measurement of the thickness of the dead layer to reduceenergy measurement errors.
We determined the dead layer thickness by measuring the incidence angle dependence of the energy loss.
We applied alpha rays from 241 Am to the Si detector
from various angles. We assumed that the energy loss
in the dead layer is proportional to the length of thealpha ray passage through the dead layer as long as
the angle is less than 70◦ with respect to the normal
incidence.
When we apply alpha rays from various angles, theenergy loss in the dead layer ∆E(θ) can be written as∆E(θ) =

∆E0
cos θ

(1)

where θ is the incidence angle of alpha rays and ∆E0
is the energy loss at normal incidence.2) We deﬁned
the normal incidence as 0 degrees. The actual detector
signal corresponds to the alpha total energy subtracted
by the energy loss in the dead layer. The measured
energy Eθ can be written asE(θ) = E0 − ∆E(θ)

Department of Physics, Rikkyo University

Fig. 1. An energy spectrum of 241 Am.

(2)

where E0 is the alpha total energy. Therefore, fromthe formula above which describes the relationship between angles and energies detected by the Si detector,
we can determine the thickness of the dead layer.
We developed a structure to set the incidence angleof alpha rays. It allows angle adjustment in 11◦ steps
with ±1◦ error. The distance of the 241 Am source fromthe detector was kept at 7 cm. The detector and the
Am source support structure were enclosed in a vacuum chamber and the readout electronics outside thechamber were connected by a D-Sub feedthrough.
∗We utilized the same preampliﬁer used for the RHIC
polarimeter. The time constant of the shaping ampliﬁer we used was 100 ns. We used a charge-integrationtype ADC CAMAC module to obtain energy spectra.
First, we measured the energy spectra of alpha raysfrom the source by applying alpha rays vertically.
An example of the spectra is shown in Fig. 1. The
three peaks correspond to 5485.6 keV, 5442.9 kev and
5388 keV 241 Am alpha rays.
We can use the energy gaps among these three peaks
for calibration purposes. For example, the diﬀerence
between the position of the rightmost peak and thatof the second peak corresponds to 42.7 keV.
Then, we measured the peak position shift when alpha rays were applied to the detector at various angles.
The peak shifts because the eﬀective thickness of thedead layer increases as the incidence angle increases.
Therefore, by ﬁtting the data with Eq. (2), we candetermine the absolute dead layer thickness.
Figure 2 shows our preliminary results. We plotted
the relationship between the energy peak positions andthe incidence angles. The dead layer thickness we estimated was approximately 40–80 µg/cm2 . We plan tostabilize the measurement to obtain ﬁnal results.

Fig. 2. Preliminary results of the incidence angle dependence of the peak position.

References
1) O. Jinnouchi et al.:Proc. 15th Int. Spin Physics Symp.
(SPIN 2002) Upton, USA, 2002-9 (AIP, 2003), p. 817.
2) G. F. Knoll:Radiation Detection and Measurement, 3rded. (Wiley, New York, 2000).

247

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RIKEN Accel. Prog. Rep. 37 (2004)

J/Ψ production in pp and d-Au collisions in PHENIX muon arms
D. E. Fields∗
Muons are an important probe of the physics forboth the heavy ion physics program (focusing on thegeneration, detection, characterization of the quarkgluon plasma (QGP) as well as studying the gluon distribution in nuclear matter) and the spin physics program (measuring the helicity distributions of ﬂavorseparated quarks and antiquarks, as well as the ﬁrst
direct measurement of the gluon polarization in the
nucleon1) ). For these purposes, the most interesting
muons originate from vector meson (J/Ψ, Υ, etc.) decays, Drell-Yan decays, W -decay, and heavy ﬂavor (cand b) meson decays. PHENIX has implimented a
two-arm (North and South) muon spectrometer at highrapidity to suppliment the photon, electron and hadron
identiﬁcation around mid-rapidity.2) Although thesemuon arms are performing well, several upgrades areplanned to improve the trigger rejection power and to
discriminate single muons based upon coincident particles (χc → J/Ψ) or oﬀset vertices (c, b → e, µ).
In RHIC Run02, data was taken with the South
Muon Arm operational, and we have recently published the results of the J/Ψ analysis for di-muonsand di-electrons in PHENIX. The combined analysis shown in Fig. 1 and Fig. 2 is discussed in detail in
Ref. 3. The statistical accuracy available with Run02
data was insuﬃcient to discriminate between diﬀerent
competing models for the J/Ψ production mechanism,
although the Color Octet Model showed good agree-

Fig. 2. Mean transverse momentum and cross-section ofJ/Ψ shown with other previous measurements at lower√
value of s. Curves are discussed in Ref. 3.

ment with the transverse momentum spectrum andthe collision energy dependence of the cross-section. A
J/Ψ polarization measurement at PHENIX will help
to make this discrimination.
For RHIC Run03, both the North and South Muon
Arms were operational and took nominal integrated
luminosities of Lint = 2.74 nb−1 in d-Au running and
Lint = 352 nb−1 in longitudinally polarized pp running. The pp data will increase our statistics for J/Ψs
by approximately an order of magnitude over the published Run02 results. The d-Au data will allow us tohelp determine the eﬀect of the initial state gluon distribution on the suppression of high transverse momentum particles seen in the Au-Au data, as well as
determining the nuclear eﬀect on the J/Ψ production
mechanism, which is still undertermined.
The Run03 data analysis is nearing completion. Remaining tasks include a detailed study of the trigger
eﬃciency, complicated by beam backgrounds and resulting high voltage depletion on the Muon Identiﬁcation subsystem.
References

Fig. 1. Rapidity dependence of J/Ψ production in Run02
pp data. Curves are discussed in Ref. 3.

∗

248

University of New Mexico, USA

1) G. Bunce et al.: Ann. Rev. Nucl. Part. Sci. 50, 525(2000).
2) H. Akikawa et al.: Nucl. Instrum. Methods Phys. Res.
A 499, 537 (2003).
3) S. S. Adler et al.: Phys. Rev. Lett. 92, 051802 (2004).

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RIKEN Accel. Prog. Rep. 37 (2004)

PHENIX silicon upgrade project
Y. Goto, Y. Akiba, H. En’yo, K. Fujiwara,∗1 J. M. Heuser, H. Kano, T. Kawasaki,∗1 Z. Li,∗2 H. Ohnishi,
V. L. Rykov, N. Saito,∗3 T. Tabaru, A. Taketani, M. Tanaka,∗4 K. Tanida,
M. Togawa,∗3 J. Tojo, and Y. Watanabe
We have been developing silicon detectors forcharged-particle tracking and precise vertex finding. A
goal of the development is to construct a silicon vertex
tracker subsystem for the PHENIX detector upgrade.
The silicon upgrade enables us the robust measurement of heavy-flavor production. It detects charged
particles with a wide acceptance coverage and identifies them as decay products from charm- or beautycarrying particles by the displacement of their trajectories to the collision vertex. The wide-ranging precise measurements of heavy-flavor production will significantly extends the physics program of PHENIX in
both heavy-ion physics and spin physics. In heavy-ion
collisions, open charm and beauty production will help
to probe the high-density matter created early during
the reaction.
In polarized-proton collisions, the silicon upgrade
enables us to reconstruct jets over a large acceptance.
The direct photon + jet measurement, as well as theheavy-flavor measurement, is a key process for thegluon polarization measurement in the proton. Although the gluon polarization measurement can beachieved using the PHENIX baseline detector, the silicon upgrade provides significantly enhanced coverageof momentum fraction of the gluon (xgluon ) and overlap of the coverage by multiple channels. In proton(or deuteron) + nucleus collisions, the enhanced coverage of xgluon enables us to investigate shadowing of
the gluon distribution in nuclei extensively.
In order to construct a barrel detector which covers
a mid-rapidity region, two types of detectors have beendeveloped. One is a silicon strip detector1) which comprises three outer barrels with radii of 6, 8, and 10 cm.
The other is a silicon pixel detector2) which comprises
an innermost barrel with a radius of 2.5 cm.
The first prototype of the silicon strip sensor wastested with a beam at KEK-PS in December 2002.
Based on results obtained in the beam test, a second
prototype sensor has been developed. The development of readout electronics of the strip sensor is an
ongoing operation with the collaboration of the Oak
Ridge National Laboratory group. The sensor will bereadout with the SVX4 chip which was developed by
a FNAL/Berkeley collaboration. The sensor, SVX4
readout chip, and electronics are being assembled andtested. A chain test of the assembled system will be
∗1
∗2
∗3
∗4

performed with an emulated PHENIX data acquisition system on a personal computer. The basic performance of the second prototype sensor will be tested
with a newly built laser test bench.
The silicon pixel detector has been developed in collaboration with the ALICE group at CERN (RIKEN–
ALICE collaboration). Many tests on and evaluationof its hybrid (sensor + bump-bonded electronics) andthe development of a readout electronics chain, which
consists of a data bus, MCM (multichip module), and
ASICs, are ongoing.3) The PHENIX hybrid and readout electronics are based on those for the ALICE experiment. The chain for the ALICE experiment wastested with a beam at CERN-SPS in November 2003.
We are also collaborating with the NA60 experimentgroup at CERN. They have a silicon pixel detector
system using ALICE hybrids. The final physics run of
the NA60 experiment was performed in October andNovember 2003. Their silicon pixel detector worked
very well.4)
Simulation studies with the PHENIX silicon upgrade
has also been performed.5) The geometry of the upgraded detector was implemented in the PHENIX simulation program, and performance of the detector has
been studied for the heavy-flavor and photon + jet
measurements.
Aiming at approval of the PHENIX silicon upgrade
project as a construction plan, the “Proposal for a Silicon Vertex Tracker (VTX) for the PHENIX Experiment” was made and submitted to Brookhaven National Laboratory in October 2003.6) This will be reviewed by the RHIC Detector Advisory Committee in
November 2003.
References
1) J. Tojo et al.: RIKEN Accel. Prog. Rep. 37, 251 (2004).
2) J. M. Heuser et al.: RIKEN Accel. Prog. Rep. 37, 250(2004).
3) H. Kano: RIKEN Accel. Prog. Rep. 37, 253 (2004).
4) H. Ohnishi et al.: RIKEN Accel. Prog. Rep. 37, 89(2004).
5) V. L. Rykov et al.: RIKEN Accel. Prog. Rep. 37, 254(2004); M. Togawa et al.: RIKEN Accel. Prog. Rep. 37,
232 (2004).
6) Y. Akiba et al.: Proposal for a Silicon Vertex Tracker(VTX) for the PHENIX Experiment (BNL, Upton,2003).

Niigata University
Brookhaven National Laboratory, USA
Kyoto University
High Energy Accelerator Research Organization (KEK)249

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RIKEN Accel. Prog. Rep. 37 (2004)

Development of silicon pixel detectors for the PHENIX experimentJ. M. Heuser, for the ALICE-RIKEN Collaboration
The Radiation Laboratory of RIKEN and the
ALICE experiment at CERN have agreed on a collaboration on the development and production of silicon
pixel detectors for a Vertex Detector upgrade of the
PHENIX experiment at Brookhaven National Laboratory’s Relativistic Heavy Ion Collider (RHIC). The
PHENIX collaboration has started a comprehensive
programme toward an upgraded experiment. Several
new detector systems will provide extended detection
capabilities in collisions of heavy ion and polarized proton beams when RHIC reaches full running at design
luminosity in the next years. The new detector systems are essential for the access to new observables ina collider upgraded to about 20 to 40 times the design luminosity in the second half of the decade. The
main PHENIX upgrade foreseen is a new Vertex Spectrometer installed between the pole faces of the central magnet. It combines high precision tracking forjet and heavy-flavor decay vertex measurement, electron identification and charged particle tracking, in its
sub-systems Silicon Vertex Detector, Micro TPC andCompact Hadron Blind Detector. The Silicon Vertex
Detector1) (see Fig. 1) comprises pixel detectors andnovel microstrip sensors. The pixel detectors are essential in its internal layer to resolve the high track
densities in heavy ion collisions.
The RIKEN group has teamed up with the ALICE
collaboration at CERN to develop pixel detector modules suited for PHENIX. The ALICE collaboration
is currently constructing a Silicon Pixel Detector for
their Inner Tracking System.2) This application is very
similar to what PHENIX plans to build. It is based on
sophisticated pixel detector technology that was developed and applied at CERN over the last ten years.3)
The pixel detectors are hybrid devices made from asensor chip and a readout chip component, interconnected with microscopic solder balls (“bump bonds”).
With the ALICE1LHCb pixel detector, the pin structure of the sensor is segmented into 32 × 256 pixels of
50×425 µ m2 size. Every sensor pixel connects througha 20 µm diameter bump bond to a matching area ofsignal processing electronic on the radiation tolerant
readout chip. Several chips can be arranged on a common sensor substrate as a building block of pixel detector modules (“ladders”).
We participate in the ALICE production of thinpixel detector ladders, and work on PHENIX specific modifications to their pixel bus and pilot readout. Thin detectors are required to minimize multiple
scattering of particles in the material. The sensors are
directly produced in their final thickness of 200 µm.
The readout chips are initially 750 µm thick after fabrication, and then thinned to 150 µm during the bump250

Fig. 1. The Silicon Vertex Detector of PHENIX will comprise four detection layers arranged in two half-shells.
The internal layer at 2.5 cm radius just outside of a newbeam pipe of reduced diameter is built from 10 pixel
detector modules (“ladders”). A half-ladder comprises
two sensor ladders, each with four readout chips bumpbonded to a silicon sensor substrate. The chips themselves are wire-bonded to a common readout bus. A
pilot module outside of the geometrical acceptance ofthe sensors interfaces the half-ladder to the data acquisition and control systems. The figures are not toscale.

bonding process. We work with industrial partners toachieve high production yield. Among other challenges
are the development of a small-pitch pixel bus withparallel readout branches, and a parallel pilot chip that
controls this readout, in order to match the high-rate
capability of the PHENIX data acquisition system.
Since two years, several members of the Radiation
Laboratory are also active in the NA60 collaboration
at CERN which studies prompt dimuon and charm
production with proton and heavy ion beams at the
SPS.4) Utilizing pixel detector technology developed
for ALICE, we contributed to the development andproduction of NA60 specific pixel detector modules
for the Pixel Vertex Spectrometer that completes theMuon Spectrometer previously used in the NA50 experiment. The pixel detectors are working well. In
November, 2003, NA60 finished the physics run with
Indium beams of 158 GeV per nucleon colliding with
Indium targets.
References
1) J. M. Heuser: Nucl. Instrum. Methods Phys. Res. A
511, 210 (2003).
2) P. Chochula et al.: Nucl. Phys. A 715, 849 (2003).
3) E. H. M. Heijne: Nucl. Instrum. Methods Phys. Res. A
465, 1 (2001).
4) J. M. Heuser et al.: AIP Conf. Proc., 698, 713 (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Development of silicon strip detector for
PHENIX silicon vertex tracker
J. Tojo, Y. Akiba, K. Aoki,∗1 H. En’yo, V. Eremin,∗2 Y. Fukao,∗1 Y. Goto, J.M. Heuser, T. Kawabata,∗3
Z. Li,∗4 H. Ohnishi, H. Okada,∗1 V. Radeka,∗4 V.L. Rykov, N. Saito,∗1 F. Sakuma,∗1 M. Sekimoto,∗5
T. Tabaru, A. Taketani, K. Tanida, M. Togawa,∗1 and Y. Watanabe
The silicon vertex tracker (VTX) has been proposed
as one of the major upgrades of the PHENIX detector.1) An overview of the PHENIX VTX project isgiven in Refs. 2 and 3. In this article, we report thedevelopment of a new single-sided silicon strip detector
for the outer three barrel layers of the VTX.
The “stripixel” detector concept4) developed by the
BNL Instrumentation Division was applied to theﬁrst prototype sensor for the VTX. A novel feature of the stripixel concept is two-dimensional position sensitivity with single-sided processing achievedby charge sharing between two interleaved electrodes in
one pixel. Collected charges are projectively read out
by double layers of strips. The sensor has the size of
34.3 mm (rφ) × 64.6 mm (z) with a thickness of 400 µm
or 250 µm and has two left-right mirror symmetric active areas of 30.7 mm × 30.0 mm. Each active area iscomposed of 384×30 pixels with 80 µm×1000 µm pitch.
Two interleaved spiral-shaped electrodes with the line
width of 7 µm and the line gap of 6 µm are called thex-cell and the u-cell, respectively. A readout line called
the x-strip connects 30 x-cells in the z-direction, andthat called the u-strip connects 30 u-cells diagonally.
The stereo angle between the x-strip and the u-strip is
4.6◦ . There are 384 x-strips with wire-bonding pads on
the left (right) side and 384 u-strips with wire-bonding
pads on the right (left) side in the left (right) active
area. The wire-bonding pad pitch is 80 µm.
Seven detectors with three 400-µm-thick sensors andfour 250-µm-thick sensors were constructed to evaluate
the stripixel sensor performance.5) Each detector consisted of one sensor, six readout chips, a base board,
two fanout boards (pitch adaptors) and two SMT
boards to read out the right active area of the sensor.
A positive bias voltage was applied to the sensor backplane (ohmic side) through the base board. The readout chip was VA2 chip,6) an analog multiplexer chipwith 128-channel charge-sensitive preampliﬁer-shaper
circuits. Six VA2 chips (three chips for 384 x-strips
and three chips for 384 u-strips) in one detector weresequentially read out with a VME-based data acquisition system with a set of modules, CAEN V550 and
V551B, suitable for dealing with analog multiplexed
signals.
∗1
∗2
∗3
∗4
∗5

Department of Physics, Kyoto University
Ioﬀe Physico-Technical Institute of Russian Academy of Science, Russia
Center for Nuclear Study, University of Tokyo
Brookhaven National Laboratory, USA
High Energy Accelerator Research Organization (KEK)

The sensor performance of charge sharing, detection
eﬃciency and position resolution has been evaluatedwith a 90 Sr β-source (2.283 MeV) and a test beam at
KEK. In the source test, three detector telescope wasoperated with the source located upstream of the ﬁrst
detector and a plastic scintillator for the trigger locateddownstream of the third detector. The beam test was
performed at the T1 beam line in KEK-PS, which delivered a positively charged particle beam with a momentum of 0.50– 2.00 GeV/c. Seven detector telescope
was operated with trigger plastic scintillators placed
upstream and downstream of the telescope. One detector in the middle of the telescope could be rotatedwith respect to the vertical direction to change thebeam incidence angle.
The charge sharing property can be characterizedfrom the asymmetry, AQ = (Qx − Qu )/(Qx + Qu ),where Qx and Qu represent collected charges at thex- and u-strips, respectively. With good charge sharing, the AQ distribution should be a narrow peak withits mean at zero. Its width depends on the incident
particle angle, θ. The widest distribution is expected
for perpendicular crossings, θ = 0◦ , and distribution
becomes narrower as θ increases. This dependence
has been observed in the beam test measurements presented in three upper rows of Fig. 1. In the test withthe radioactive source, the AQ distribution was eﬀectively smeared with the electron incidence angle, resulting in its shape and width as for nonzero θ. The
narrow distributions for θ = 15◦ and 30◦ in the beam
test represent evidence that the stripixel principle isworking and that a good two-dimensional position sensitivity is achievable. However, the broad distributionfor θ = 0◦ with two peaks at AQ ∼ ±0.2 is clear indication that, for perpendicular crossings, quite frequently,
almost all of the charge is collected either at the x- or
u-cell with little charge sharing. Improvement of thecharge sharing property is expected by fabricating aﬁner stripixel structure with smaller center-to-center
distances between x- and u-cells.
Detection eﬃciencies and signal-to-noise (S/N ) ratios were measured in the beam test. The detection
eﬃciencies were ∼97% for the detectors with the 400µm-thick sensor and ∼60% for those with the 250-µmthick sensor. The S/N ratios were ∼17 for the 400-µmthick sensor and ∼9 for the 250-µm-thick sensor. The
poorer detection eﬃciency and the S/N ratio of the detector with the 250-µm-thick sensor, compared to the
400-µm-thick sensor, were mainly due to lower ioniza-

251

Fig. 1. The AQ distributions and correlations between Qx
and Qu measured in the beam test (three upper rows)
and with the radioactive source (bottom row).

tion and greater electronic noise. For electronic noise,
there is still room for improvement by optimizing theoperating conditions. The better charge sharing between x- and u-cells in the ﬁner structured detector
will also contribute to the improvement of the detection eﬃciency and S/N ratio.
The position resolutions were measured in the beam
test from the residuals of hits on reconstructed particle trajectories. The expected position resolutions
from the pixel√ pitch of 80 µm (rφ)× 1000 µm (z) are
σx = 80 µm/ 12 = 23 µm in the x-strip√ from the rφdirection pixel pitch, σz = 1000 µm/ 12 = 289 µm
from the z-direction pixel pitch and σu = σx cos α ⊕σz sin α = 33 µm in the u-strip, where α and ⊕ repre-

252

sent the stereo angle between the x- and u-strips andthe quadratic sum, respectively. After deconvoluting
contributions of the setup geometry and multiple scattering, the measured position resolutions of the detector were σx  23 µm for the x-strip and σu  31 µm forthe u-strip. These results are in the good agreementwith the expectations.
To study the electrical properties of the stripixel sensor and to determine the optimum operating conditions, a laser test setup was constructed at the BNL
Instrumentation Division. The study is based on thetransient charge/current technique.7) A nanosecond
pulsed laser coupled into a focuser through an opticalﬁber was operated with a pulse generator. A red laser
with the wavelength of 635 nm and the penetration
depth of 3 µm in silicon was used to study the separate
collection of electrons and holes. An infrared laser withthe wavelength of 1060 nm and the penetration depthof 800 µm in silicon was used to study the detector response to the charge deposition of a minimum ionizing
particle. The focuser was ﬁxed to an XYZ motorizedstage. The precision of laser spot positioning with the
motorized stage was 0.5 µm. The laser spot size of
approximately 10 µm in diameter was achieved in theconstructed setup. The existing setup and/or an upgraded setup which has an automatic multiaxis motor
drive control will provide the basic tool for quality control of the sensors and, later, of the assembled detector
ladders.
The second prototype stripixel sensors, which has
the ﬁner center-to-center distance between x-cell andu-cell lines, are under processing and are expected toshow the better performance on charge sharing. The
SVX4 chip8) developed for the Run IIb silicon vertex
detector upgrades of the CDF and D0 detectors at the
Fermilab Tevatron is planned to be used as the readout
chip for the silicon strip detectors in the VTX. The detector with the second prototype sensor and the SVX4
chip is under development.
References
1) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res. A
499, 469 (2003).
2) J. M. Heuser: Nucl. Instrum. Methods Phys. Res. A
511, 210 (2003).
3) Y. Goto et al.: RIKEN Accel. Prog. Rep. 37, 249(2004).
4) Z. Li: BNL Internal Report, BNL Rep., No. 67527, 1(2000); Z. Li et al.: RIKEN Accel. Prog. Rep. 36, 250(2003).
5) J. Tojo et al.: RIKEN Accel. Prog. Rep. 36, 252 (2003).
6) http://www.ideas.no/7) V. Eremin et al.: Nucl. Instrum. Methods Phys. Res. A
372, 388 (1996).
8) http://www-cdf.lbl.gov/users/mweber/svx4/

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RIKEN Accel. Prog. Rep. 37 (2004)

Development of pilot readout electronics for
the PHENIX pixel detector
H. KanoThe Radiation Laboratory in RIKEN and the CERNALICE Pixel group have established a joint program
for the development of silicon Pixel Detectors, to be
used for the upgrading of the PHENIX detector at
Brookhaven National Laboratory’s Relativistic Heavy
Ion Collider (RHIC).
The PHENIX collaboration has started a study for
an upgraded experiment. Several new detector systems
will provide extended detection capabilities in collisions of heavy ion and polarized proton beams when
RHIC reaches full operation at the design luminosity
in the next few years. These systems are essential forthe access to new observables in a collider upgraded
to about 20 to 40 times the design luminosity in thesecond half of the decade. The main PHENIX upgrade foreseen is a new Vertex Spectrometer installed
between the pole faces of the central magnet. It combines high-precision tracking for jet and heavy-flavor
decay vertex measurements, electron identification andcharged particle tracking in its subsystem Silicon Vertex Detector, Micro-TPC and Compact Hadron Blind
Detector. The Silicon Vertex Detector comprises pixel
and novel microstrip sensors. The pixel detectors in
the internal layer are essential for resolving the hightrack densities in heavy ion collisions.
The Radiation Laboratory in RIKEN has teamed
up with the ALICE collaboration at CERN to develop pixel detector and readout modules suited for
PHENIX. The ALICE collaboration is currently developing a Silicon Pixel Detector for their Inner Tracking System.1) This system is similar to what PHENIX
plans to upgrade. It is based on sophisticated pixel
detector technology that was developed and applied at
CERN over the last ten years.
The on-detector pilot readout electronics2) of the
ALICE silicon pixel detector (nearly 10 million pixels)
consists of 1200 readout chips bump-bonded to a silicon sensor and mounted on the front-end bus, andof 120 control (PILOT) chips mounted on multichip
modules (MCM), as shown in Fig. 1, together with
opto-electronic transceivers. The front-end chips are
all ASICs designed in a commercial 0.25-micron process, and are used to transmit data over an optical fiber
to the control room where the actual data processing
and event building are performed. This system can beapplied to PHENIX with minor modifications.
We joined in on component tests of the detector andthe pilot readout system (MCM), and are participatingin their integration test. The integration test setup is
shown in Fig. 2. The tests performed on the entire ondetector readout chain and the optical communication

Fig. 1. Fully functional prototype multichip module(50 mm × 15 mm, green board) with all ASICs and optical package. This MCM is mounted on an adapter
board.

Fig. 2. Test setup of detector and on-detector readout system (MCM).

between the control room and detector proved them
to be work reliable. The bidirectional optical link has
been successfully tested.
We are working on the modifications of the readout control ASIC on the MCM to optimize it to the
PHENIX experiment which requires much higher readout speed and data rates (40 µs/event in PHENIX,
256 µs/event in ALICE). The prototype ASIC has beendeveloped for testing the additional zero-suppression
circuit and wide bus to achieve higher readout speed.
We have started the development of the ASIC with fullfunctionality for the PHENIX pixel readout.
References
1) P. Chochula et al.: Nucl. Phys. A 715, 849 (2003).
2) A. Kluge et al.: Proc. 7th Workshop on Electronics for
LHC Experiments, Stockholm, Sweden, 2001-9 (CERN,
2001), p. 95.

253

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Semileptonic decays of open charm and beauty in the PHENIX
central arm with the silicon vertex detector upgrade
V. L. Rykov, Y. Akiba, M. D. Baker,∗1 Y. Goto, J. M. Heuser, C. A. Ogilvie,∗2
H. Ohnishi, K. Tanida, J. Tojo, and C. Woody∗1
The PHENIX detector1) at the Relativistic Heavy
Ion Collider (RHIC) in BNL is designed to perform
a broad study of A-A, p-A and p-p collisions. The
prime motivation for the recently proposed Silicon Vertex Tracker (VTX) upgrade2) was to enhance PHENIX
capabilities for precise measurements of heavy quark
yields, which are a sensitive probe of the early stageof heavy-ion collisions and are critical for the physics
goals of proton spin structure and for structure function studies in p-A reactions. The semileptonic decaysof charm and beauty, c → e± + X and b → e± + X, areabundant sources of electrons within the acceptanceof PHENIX Central Arm.3) However, these electrons
need to be separated from the background electrons,ﬁrst of all from Dalitz decays and γ-conversions in detector material. We plan, using the VTX, to identify
heavy ﬂavor decay vertices, which are displaced fromthe primary event vertex by about a hundred or more
microns.
The VTX (Fig. 1) represents a set of four concentric barrels of silicon detectors with a length of approximately 30 cm along the beam (z-axis). The innermost barrel at a radius of 2.5 cm consists of hybrid silicon pixel detectors4) with a pitch size of 50 × 425 µm2 .
The outer three barrels at radii 6, 8 and 10 cm arecomposed of silicon strip detectors5) with two sets ofstereo strips of dimension 80 µm × 3 cm, creating eﬀective pitches of size ∆rϕ × ∆z = 80 × 1000 µm2 . The
expected VTX resolution for the track’s distance-ofclosest approach (DCA) to the known primary vertex
is ∼20–50 µm in the xy-plane. This is well below the cτvalues of ∼100–500 µm for charm and beauty mesons.
The power of this resolution is seen by comparing the
PYTHIA+GEANT simulated DCA distributions fromcharm, beauty and Dalitz decays in Fig. 2. A DCA
cut of ∼150–200 µm removes the majority of Dalitz

Fig. 2. DCA distributions for electrons from Dalitz, charmand beauty decays simulated through four Si layers ofthickness 2% of a radiation length per layer.

contribution from the electron yield even at low electron transverse momenta, PT , just above 1 GeV/c.
Figure 3 compares signal-to-background ratios with
the DCA cut to the case of no VTX. It is apparent
that using the VTX detector will dramatically reduce
the systematic errors due to uncertainties in the background subtraction, thus opening the opportunity fortruly model independent measurements of open heavy
ﬂavor yields.

Fig. 3. Signal-to-background ratios for electrons from open
charm (left) and beauty (right) as a function of electron PTcut for DCAcut = 200 µm. Dalitz decays andγ-conversions are taken as a background. Shown simulations results are for VTX thickness of 1% and 2% ofradiation length per layer.

References

Fig. 1. The VTX schematic view.
∗1
∗2

254

Brookhaven National Laboratory, USA
Iowa State University, USA

1) K. Adcox et al.: Nucl. Instrum. Methods Phys. Res. A
499, 469 (2003).
2) Y. Goto et al.: RIKEN Accel. Prog. Rep. 37, 249(2004).
3) K. Adcox et al.: Phys. Rev. Lett. 88, 192303 (2002).
4) J. M. Heuser et al.: RIKEN Accel. Prog. Rep. 37, 250(2004).
5) J. Tojo et al.: RIKEN Accel. Prog. Rep. 37, 251 (2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Muon trigger upgrade with W production for PHENIX muon arms
A. Taketani, K. Aoki, K. Barish,∗ A. Deshpande, M. Grosse Perdekamp, N. Saito, and W. Xie∗
The intermediate weak boson W, is an excellent
probe to investigate the spin structure of proton.1) The
parity-violating nature of the weak interaction can provide the polarization of light quarks and antiquarks ina proton through measurements of longitudinal single−σ−, where P is beam pospin asymmetry, AL = P1 σσ++ +σ−
larization. If a larger rapidity of the produced W bosonis considered, it can be expressed by quark and antiquark polarizations, as well as an unpolarized parton
distribution function,+≈∆u(x1 ),u(x1 )AW
L+≈−∆d(x1 ),d(x1 )

AW
L

AW
L

−

≈

∆d(x1 ),d(x1 )

for x1  x2 ,

and
AW
L

−

≈

−∆u(x1 ),u(x1 )
for x1  x2 .

The PHENIX muon arm is designed to detectmuons, Pµ > 2 GeV/c with 1.2 < |η| < 2.4 over afull azimuthal range coverage.2) Since MW is 80 GeV,
muons from W are easily identiﬁed by requiring Pt >20 GeV/c. Muon arm has 8 times larger acceptancethan the PHENIX central arm for detecting electrons
from W decays. The muon arm will act a signiﬁcantrole in the investigation of quark ﬂavor decomposed
spin structure function. On the other hand, the production cross section of W bosons is small, which isorder of 1 nb. Thus ∼ 104 events for the muon channel√are expected with 800 pb−1 integrated luminosity
at s = 500 GeV. The design instantaneous luminosity is 2 × 1032 s−1 cm−2 . Since the total cross sectionof proton-proton collision is 60 mb, the event rate willbe 12 MHz. PHENIX DAQ system can handle maximum 12 kHz at level 1 trigger (LV1) output for several
rare event channels.3) If 2 kHz of the LV1 bandwidthis dedicated to a single muon trigger, a rejection factorof 6000 will be required. The current muon LV1 rejection√ factor is measured to be 250 with Run3 p-p data
at s = 200 GeV. So the LV1 rejection factor must be
improved by more than 24.
The muon arm consists of two major parts. One is
the muon tracker (MuTr) which determines momentum using the 3 layers of cathode readout chambers inmagnetic ﬁeld.2) The other is muon identiﬁer (MuId)
which works as a range counter to distinguish muons
from other hadrons. Also MuID is used as a trigger counter.4) The muon trigger eﬃciency rises fromzero at 1.8 GeV/c and becomes saturated at 2.5 GeV/c.
Lower momentum muons dominate trigger and reconstructed tracks.5) It is very hard to increase this momentum threshold by adding more absorber materials∗

due to the space limit of the PHENIX experimental
hall.
There are two methods for increasing momentum
threshold in order to reduce single muon trigger rate.
The one method involves using a threshold-typeČherenkov detector. Figure 1 shows the conﬁguration of the test Čherenkov counter setup we installed at PHENIX during the Run3 proton-proton
collision period and the collected data as part of the
PHENIX detector. The radiator of Čherenkov is 1 atm
CO2 and the momentum thresholds are 3.5 GeV/c and
17 MeV/c, for the muon and the electron, respectively.
The coincedences of scintillators S1 and S2, are usedas the trigger signal. Electrons, which are associatedwith the incident muon, may ﬁre Čherenkov counter,even if muon momentum is below Čherenkov threshold.
Two aliminum plates with 5 cm thickness are expected
to absorb these electron. We obtained a 3–7 rejection
factor with only the Čherenkov counter by analyzingthese data. This is much smaller than the required
rejection factor of 24.
The other method involves using fast momentum
tracking. MuTr can readout only very slowly due to its
cathode strip readout feature. We consider to put additional tracking devices in front and back of the MuTr
with a faster readout time. The incident muon is bent
in the azimuthal direction by the radial magnetic ﬁeld.
By measuring the azimuthal deviation across MuTr,
momentum is determined. Detailed detector simulations are used to investigate rejection factor, and optimize additional device conﬁguration.

Fig. 1. Configuration of test Čherenkov counter setup: S1,
S2, S3, and S4 indicate scintillation counters. Al’s
represent 5 cm alminum plates. The radius of theČherenkov cross section is 23 cm.

References
1) N. S. Craigie et al.: Phys. Rep. 99, 69 (1983); C.
Bourrely et al.: Phys. Rev. D 59, 95 (1980).
2) H. Akikawa et al.: Nucl. Instrum. Methods Phys. Res.
A 499, 537 (2003).
3) S. S. Adler et al.: Nucl. Instrum. Methods Phys. Res.
A 499, 560 (2003).
4) H. D. Sato et al.: RIKEN Accel. Prog. Rep. 36, 240(2003).
5) A. Taketani et al.: RIKEN Accel. Prog. Rep. 36, 228(2003).

University of California, Riverside, USA

255

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RIKEN Accel. Prog. Rep. 37 (2004)

eRHIC: Progress and status
A. Deshpande, for the eRHIC Collaboration
The possibility of building an intense and polarized
electron/positron beam facility adjacent to the Relativistic Heavy Ion Collider (RHIC) at BNL which could
enable lepton-hadron Deep Inelastic Scatter (DIS)
has been discussed in previous annual reports.1) We
present the status and progress on this project in thispaper.
The 10 GeV polarized lepton beam facility will collide with the 100 GeV heavy ion or the (up to)
250 GeV polarized proton beams at RHIC, resulting
in a eﬀective Center of Mass (CM) energy of 63 and100 GeV for e-A and e-p collisions, respectively. Neither lepton-nucleus nor polarized e-p/n collisions havebeen performed above 30 GeV in CM energy. Further, it would be the ﬁrst time these studies would
be performed in collider geometry, enabling a systematic study of target as well as beam fragments.
Because of RHIC’s unique ability to vary the beamspecies all the way from polarized and unpolarized
protons (p), unpolarized and (possibly) polarized helium (He), lithium (Li) to lead (Pb) or uranium (U),will allow an unprecedented study of fundamental anduniversal aspects of QCD including nucleon spin. The
eRHIC facility at BNL would also be an attractive experimental facility because of two additiona reasons:(1) All experiments could be performed with a single detector, which will enable signiﬁcant reduction in
the systematic uncertainties of measurements requiring comparison of results under diﬀerent collision circumstances, (2) The high luminosity provided by thecollider 1 × 1033 cm−2 sec−1 for e-p and a factor 100
down from that for e-A physics
Speciﬁcally, eRHIC will address the following questions related to QCD about which we presently know
very little: (1) How do we understand the momentum
distribution and spin content of protons and neutrons
in terms of fundamental quarks and gluons? (2) Whilein high energy collisions quarks and gluons are involved, only hadrons are observed in the ﬁnal states.
Can we understand this phenomenon of hadronization?
(3) What roles do quarks and gluons play in the microscopic structure of the nuclei? (4) Can we observe newphenomenon predicted by QCD involving saturationof gluons at high energies, similar to the Bose-Einsteincondensation in atoms at low temperatures?
Attracted by such unique physics possibilities a large
and diverse group of people have now formed a collaboration to ﬁnalize the design for eRHIC and its
detectors. The electron beam design is being devel-

256

oped on two fronts: 1) a ring-ring design in which one
adds a 10 GeV electron ring facility (injected in to by
a 10 GeV super-conducting linac). The electron ringin this design will be approximately 1/3 in diameterof the RHIC, and 2) a linac-ring collider facility inwhich the 10 GeV linac collides with the RHIC hadronbeams. It is assumed that collisions could take place at
two or three beam energies between 5 and 10 GeV electron beams. Presently the ﬁrst option is considered tobe more probable one, but detailed design reports on
both are awaited. The Ring-Ring option is being developed by the BNL-MIT/Bates collaboration with close
ties with the DESY accelerator physicists. The LinacRing design is being developed by the BNL-JLAB accelerator physicists. A Zeroth Design Report (ZDR)
has been requested by the BNL management by early
January 2004 which will be reviewed by an external
committee by mid-2004.
Based on the ﬁrst versions of the accelerator latticeand IR design, the eRHIC detector WG has started
studies related to the synchrotron radiation and related problems which might arise at this facility. This
work needs close communication between the accelerator and physics working groups, and is being carriedout through monthly meeting between people in both
WGs. A detailed simulation of the IR and the synchrotron radiation related background in the present
eRHIC lattice are under way and are expected to guide
us to the ﬁnal IR Design. These and such studies willthen lead to the technology selection eﬀort for diﬀerent physical variables in terms of the detector components. There is a broad interest developing amongst
the HERA-III interested physicists to do experiments
at eRHIC if HERA-III program does not realize at
DESY. They have joined the eRHIC detector design
eﬀort in recent past.
Having gone through various NSAC and its subcommittee reviews in the years 2002 and 2003, inNovember 2003, the US DoE declared2) that eRHIC
would be one of the 28 “must-do” major scientiﬁcprojects to pursued by the US oﬃce of Science andTechnology in the next 20 years.
References
1) eRHIC Collaboration, A. Deshpande: RIKEN Accel.
Prog. Rep. 35, 221, 228 (2002); RIKEN Accel. Prog.
Rep. 36, 232, 233, 236, 237, 259 (2003).
2) http://www.science.doe.gov/Sub/Facilities for future/facilities future.htm

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RIKEN Accel. Prog. Rep. 37 (2004)

CCJ operation in 2002–2003
S. Yokkaichi, Y. Goto, H. Hamagaki,∗ T. Ichihara, O. Jinnouchi, A. Kiyomichi, Y. Watanabe, and H. En’yo
CCJ,1) RIKEN Computing Center in Japan for
RHIC2) physics, started operation from June 2000 as
the largest oﬀ-site computing center for the PHENIX
3)experiment at RHIC. CCJ ﬁlls, in PHENIX computing, the three roles of (1) the simulation center, (2) Asian regional center and (3) center of spin
physics. Recently DST (Data Summary Tape) production from raw data comes more important than simulation for CCJ role. Other smaller computing centersin PHENIX can handle only relatively small simulation data, however, only CCJ can handle several tensof TB of raw data except RCF (RHIC computing facility)4) because of our HPSS (High Performance Storage
System)5) and data duplication facility built by us at
RCF to transfer the data to CCJ.
Many analysis and simulation projects are being
carried out at CCJ, including some PHENIX-oﬃcial
projects. They are shown on the web page:
http://ccjsun.riken.go.jp/ccj/proposals/.
Within the current year, the data from PHENIX
Run2 (2001/8–2002/1) and Run3 (2002/11–2003/5)
were mainly analyzed. The report from each project is
described in this volume.
About 50 TB of data were transported from BNL via
tape media (42 TB) and network (9.1 TB) within thisyear. In a typical shipment of tapes, 17 TB of data aretransferred in 33 days which includes tape transport by
airplane, uploading to CCJ-HPSS and all limited factor of troubles. It means 6 MB/s of transfer rate on average. Via network, the typical transfer rate from BNL
is 3–4 MB/s and approximately 12 MB/s was observed
as the maximum burst rate retained in 20 minutes. In
such large-scale network transfer, multi-stream transfer was mainly used with the bbftp 6) command. The
data amounts recorded at PHENIX and sent to CCJ
are summarized in Table 1. Typical ﬁle sizes of thedata are also shown.
The DST hierarchy in PHENIX is as follows. In eachstage, the data size is reduced for easier handling. An
event reconstruction process writes the DST in ‘root’7)
format from the raw data. While the typical ﬁle size ofraw data is 1.5 GB, DSTs are reduced to 0.6–1.8 GB.
The µDST is written in the ‘root tree’ format andsome information included in DST is dropped. TypicalµDST size is 0.1–0.3 GB. The nanoDST(nDST)s aresubsets of µDST which has only limited events and/or
information which is selected with special interest foreach group of users. The nDSTs have a size of 10–
80 MB typically. In principle, we transfer all DST,
µDST and nDST, etc., from RCF to CCJ. For the raw
data, all the p+p data for spin physics and a certain∗

Center for Nuclear Study, University of Tokyo

Table 1. PHENIX data amount as of Dec. 2003.
Run1 Run2
HIHI
raw data
recorded (TB)
2.3
(transferred to CCJ)
2.3
typ. file size (GB)
1.5
DST (version)v05
produced (TB)
2.6
(transferred to CCJ)
2.6
typ. file size (GB)0.3–0.6µ/nDST (version)v05
produced (TB)
(transferred to CCJ)
typ. file size (GB)
0.1–0.2
§

p+p

20
26
7
26
1.5
1.5
v03 v01/2
17.5
-§
8.2
1.8
0.6
v03 v01/2
4
6.6
0.3
0.1

Run3
HI p+p
49
-§
1.5
v03
12.4
-§
0.5

39
39
1.5
v03
4.3
0.2

-

-

transfer is on goingfraction of Heavy Ion (HI) data are also transferred.
This principle was provisionally conﬁrmed at the CCJ
users meeting in Sep. 2003. While raw data and DST
are transferred via tape solely by the CCJ administrator, µ/nDST are transferred via network with signiﬁcant cooperation from users.
The current conﬁguration of CCJ is shown in Fig. 1.
We have 176 PC nodes operated using Linux, 166 are
calculation nodes and 10 are service nodes. Each calculation node has 1 GB of memory, 2 GB of swap area,
10–31 GB of local work area and dual CPU (Pentium
III 700 MHz–1.4 GHz, Pentium 4 2.0 GHz). Red Hat
7.2/kernel 2.4.18 is operated on the calculation nodes,
the same as RCF. Upgrading to Red Hat 8 is planned
in Jan. 2004. We also have seven SUN servers oper-

Fig. 1. Current configuration of CCJ.

257

ated using Solaris, two are service nodes and ﬁve aredata servers, which are connected to large RAID systems and operated as NFS servers. Service nodes areused for various purposes, for example, login server
from WAN, database server for analysis, AFS client toshare the PHENIX computing environment, controllerof PC cluster, and monitoring of PC nodes and network.
HPSS is used as a mass storage system in CCJ, thesame as RCF. Approximately 150 TB/450000 ﬁles ofdata are stored in CCJ-HPSS as of Oct. 2003. Five
IBM RS6000/SP servers operated using AIX are used
as HPSS core server and data/tape movers.
On the calculation nodes, LSF8) 4.2 is operated
as a batch queueing system. Three general queues,
short/long/bg, are categorized by CPU time limit, 200
minutes/1 day/7 days, respectively. Special queues for
production (high priority), largedisk (dispatched to thenodes on which large disk/memory space remain) etc.
are also set temporally or perpetually for special purposes. The priority of job dispatching in the queues is
not ‘ﬁrst-in ﬁrst-served’ but is controlled by the fairshare policy of LSF, taking account of the CPU usage
history by each user. Two job slots are assigned toeach node because they have dual CPU. In the system, 20–30 job slots are kept for the short queue without being ﬁlled by longer jobs to maintain a shorter
turnaround time for small-scale jobs. The number ofrunning jobs in each queue is monitored using MRTG9)in addition to data ﬂow between PCs and data servers
or HPSS thus the state of the system is always watched
by WEB.
The jobs submitted to CCJ are roughly categorized
into two types, CPU bound and I/O bound. TypicalCPU-bound jobs are simulation jobs (detector simulation and event generation) and event reconstruction(DST production) jobs. Typical I/O bound jobs aredata reduction jobs, i.e., making µDST (or nDST)
from DST (µDST) and analysis of µ/nDST, i.e., reading the data and making small histogram ﬁles. In CCJ,
such I/O bound jobs are limited by the I/O bandwidthof HPSS and/or RAID disks in which the required data
are located. Particularly, concurrent NFS access frommany PC nodes (typically more than 20) degrades the
I/O throughput. In order to avoid such a situation, we
use the rcp command to access the RAID disk. Jobs
running on a PC have to transfer the data between
the RAID and PC-local disk by rcp, and only work on
the local disk. Actually, many concurrent rcp’s alsodegrade the throughput, hence we limit the numberof maximum rcp processes on each data server. By
the use of the limited rcp, I/O of RAID is maintained
at 30–50 MB/s in contrast with NFS access which canachieve only 10 MB/s.
Hardware upgrades in this year are as follows. No
CPUs were upgraded but several tens of motherboards were replaced to get rid of the node hanging-up

258

problem. FC RAID disks of 8 TB were newly connected to SUN Fire 880 and the total capacity was increased to approximately 33 TB. In HPSS, tape drives
were replaced from four STK 9940A (I/O 10 MB/s,
capacity 60 MB/cartridge) to six 9940B (30 MB/s,
200 MB/cartridge). All the data written in the 9940A
format have already been rewritten in the 9940B format. Since we have 3000 tape cartridges, the total tapecapacity is 600 TB currently. In the data duplication
facility at RCF, two Redwood drives were replaced by
two 9940B’s and the host machine was also replaced,from IBM RS6000 F50 to IBM p630. The connection
between RIKEN LAN to WAN was also replaced inJune 2003, from IMnet (50 Mbps) to SINET (1 Gbps).
We have encountered the hardware problems described below this year. PC nodes encounter various
hardware problems including problems of the fan, disk
(itself and SCSI I/F board), memory, CPU and power
supply. Approximately 15% of PC nodes (almost belong to older node group) suﬀered from such problems.
Data servers also encounter hardware problems in the
RAID controller, I/F PCI card between FC (ﬁbre channel) RAID and server, FC GBIC and FC hub. To
solve them, we needed to shutdown at least one dataserver per month on average. The simple break downof disks in the RAID system is not counted here because such disks are hot-swappable, i.e., they can be
replaced without stoppage of service. In spite of these
problems, data on the disks have not been lost thusfar.
We have proceeded now to a project of integrated
operation between CCJ and the new RIKEN supercomputer system. The new system includes 1024
nodes/2048 CPUs of a PC cluster system and we canuse dedicated 128 nodes/256 CPUs in the cluster. Ourdata servers and HPSS can also be accessed by the newcluster nodes the same as for our old PC nodes. HPSS
server machines will be replaced by seven IBM p630
servers and we can use eight 9940B tape drives connected to four data/tape movers and one tape robot(STK Powderhorn 9310) dedicatedly. The robot canhandle approximately 5000 tape cartridges, thus we
can extend the total tape capacity to 1 PB. The integrated system will be available in March 2004.
References
1) http://ccjsun.riken.go.jp/ccj/
Y. Watanabe et al.: RIKEN Accel. Prog. Rep. 36, 262(2003); T. Ichihara et al.: RIKEN Accel. Prog. Rep. 35,
236 (2002).
2) http://www.bnl.gov/rhic3) http://www.phenix.bnl.gov4) http://www.rhic.bnl.gov/RCF/
5) http://www.sdsc.edu/hpss/
6) http://doc.in2p3.fr/bbftp/
7) http://root.cern.ch8) http://www.platform.com/products/LSF/9) http://people.ee.ethz.ch/˜oetiker/webtools/mrtg/

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Azimuthal asymmetries in fragmentation processes at BelleK. Hasuko, M. Grosse Perdekamp,∗1 J. S. Lange,∗2 A. Ogawa,∗3 and V. Siegle∗4
In an unpolarized e+ e− annihilation, nontrivial
azimuthal asymmetries may exist, which determine
novel chiral-odd fragmentation functions, such as the
Collins-Heppelmann function, H1⊥ ,1) and the two-pion
interference fragmentation function, δ q̂ h . We are extracting these functions using e+ e− collision data fromthe Belle experiment2) at the KEK B-factory.3) Thesenovel functions are also expected to be a powerfultool for accessing the quark transversity distributionof a proton, δq.4)
The fundamental observable for measurements of
H1⊥ in e+ e− −→ π + π − X (π + and π − should be in different jets) is the angle φ0 between the “pion plane”
formed by two pion momentum vectors pπ1(2) andthe “reaction plane” formed by either of pπ1(2) andthe beam axis.5)a) The angular dependence of a differential cross section is expressed as (1 + cos2 θ ∗ )×Dqπ1 (z1 )Dq̄π2 (z2 )+sin2 θ ∗ cos(2φ0 )H1⊥ (z1 )H1⊥ (z2 ), using the spin-averaged fragmentation function Dqπ (z),the momentum fraction z1(2) , and the center-of-massangle between the incoming electron and the pion
deﬁning the reaction plane θ ∗ .
We are studying on H1⊥ using 32 million q q̄ datataken in the continuum region 60 MeV below the Υ(4S)
resonance. Details about the analysis method andevent selection were reported in Ref. 6. We observed
large background asymmetries in cos(2φ0 ) distributions. The main background sources are (1) the limitation of detector acceptance and (2) gluon radiation. The background asymmetries arising from detector acceptance can be canceled by applying ﬁducial cuts for pions (see Fig. 1). We also used anothermethod of eliminating the background by taking theratio of asymmetry distribution between pion pairs selected under two contrary conditions (e.g. unlike-signpairs and like-sign pairs); here, we can expect the samedetector eﬀects and other common systematics to becanceled while the diﬀerence in analyzing power for
H1⊥ remains.
Asymmetries arising from gluon radiation are expected to have QT dependence, where QT is the transverse momentum of a photon in the center-of-massframe of two pions (Collins-Soper frame). Althoughthese asymmetries have the same cos(2φ0 ) dependence,
they can be separated on the basis of QT dependence;the expected QT dependence on Collins and gluon radiation is illustrated in Fig. 2.
Detailed studies on background subtraction are
nearly completed and extraction of H1⊥ is in progress.
The asymmetries are expected to have sin2 θ ∗ dependence, which could help extract the relatively small
asymmetries we are aiming at. We also plan to process
on-resonance data (containing bb̄) to increase statistics
and use bb̄ decays as a control sample. This study has
been performed at RIKEN CCJ.

Fig. 2. Comparison of expected analyzing powers between
H1⊥ and gluon radiation as a function of QT .

References

Fig. 1. Comparison of cos(2φ0 ) dependences between raw(thin) and fiducial (thick) cuts.
∗1
∗2
∗3
∗4

University of Illinois, USA
University of Frankfurt, Germany
Brookhaven National Laboratory, USA
University of Heidelberg, Germany1) J. C. Collins: Nucl. Phys. B 396, 161 (1993); J. C.
Collins, S. F. Heppelmann, and G. Ladinsky: Nucl.
Phys. B 420, 563 (1994).
2) Belle Collaboration, S. Mori et al.: Nucl. Instrum.
Methods Phys. Res. A 479, 117 (2002).
3) KEK B Factory Design Report, KEK Rep. 95-7 (1995)(unpublished).
4) M. Grosse Perdekamp, A. Ogawa, K. Hasuko, J. S.
Lange, and V. Siegle: Nucl. Phys. A 711, 69 (2002).
5) D. Boer, R. Jakob, and P. J. Mulders: Phys. Lett. B
424, 143 (1998).
6) K. Hasuko et al.: RIKEN Accel. Prog. Rep. 36, 260(2003).
a)φ1(2) are also defined using jet axis. Details can be seen in
Ref. 6.

259

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RIKEN Accel. Prog. Rep. 37 (2004)

Progress on precision measurement of fragmentation functionsat Belle
V. Siegle,∗1 J. S. Lange,∗2 M. Grosse Perdekamp,∗3 K. Hasuko, and A. Ogawa∗2,∗4
The Belle experiment at the asymmetric e+ e− collider√ KEK-B at Tsukuba, Japan, is usually operating
at s = 10.58 GeV, corresponding to the mass of theΥ(4S) meson. The Υ(4S) meson decays with a branching ratio of ∼ 100% into BB pairs, providing a highstatistics B meson sample for the study of, for example, CP violation and rare decays in the B meson
system. For background√ studies, ∼ 10% of the datataking is performed at s = 10.52 GeV, 60 MeV below
the Υ(4S) resonance. Such data can be used for very
accurate QCD studies.
The fragmentation function Dqh (z, Q2 ) denotes theprobability of ﬁnding a hadron h in the fragmentation of a quark q (q = u, d, s, c, b). The variable z denotes the fraction of momentum transferedfrom the quark to the hadron. In leading order QCD,
the normalized hadronic diﬀerential cross section fora hadron h can be expressed 2 h by fragmentation func+ −e e →hX=
tions σ1h dσ dz
0eq Dq (z)

q

 2
eq

, where eq is the quarkqcharge. The available world data on the normalized
hadronic cross section1) are shown in Fig. 1. It can beseen that the precision of the available
data at high z√
is limited. In particular, at low s, precise fragmentation function data are not available. We have investigated the possibility of re-measuring fragmentation
functions at Belle utilizing the highly integrated luminosity available at KEK-B and the excellent particle
identiﬁcation capabilities of the Belle detector. Precision fragmentation functions would serve as input toa global QCD analysis of longitudinal spin asymmetries in inclusive hadron production at RHIC in polarized pp collisions.
Our preliminary results are very encouraging. As
an example, we show the fragmentation function forcharged pions in Fig. 2 on an arbitrary scale. The
plot uses 1.7 × 105 events, corresponding to 0.3% of theavailable statistics. For comparison, we have included
parametrizations of fragmentation functions, obtained
from global QCD ﬁts to existing fragmentation function data. The full data set will extend to the highest z
with good precision. The situation for kaon fragmentation functions is quite similar. At present, we areprocessing the full data sample and carrying out systematic error studies.

∗1
∗2
∗3
∗4

260

University of Heidelberg, Germany
University of Frankfurt, Germany
University of Illinois, USA
Brookhaven National Laboratory, USA

Fig. 1. World data set measurements of the normalized
hadronic cross section.1)

Fig. 2. Preliminary fragmentation function for charged
pions for a data set of 1.7 × 105 hadronic events at√
s = 10.52 GeV, compared to parametrizations fromKretzer2) and Kniehl, Krämer and Pötter.3) Only statistical errors are shown.

References
1) O. Biebel, P. Nason, and B. R. Webber: hep-ph/0109282, Phys. Rev. D 66, 010001 (2002).
2) S. Kretzer: Phys. Rev. D 62, 054001 (2000).
3) B. A. Kniehl, G. Krämer, and B. Pötter: Nucl. Phys. B
582, 514 (2000).

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RIKEN Accel. Prog. Rep. 37 (2004)

Development of trigger and DAQ system for SVD2.0 at BelleK. Hasuko
The Silicon Vertex Detector (SVD) plays an important role in the Belle experiment1) at the KEK B factory (KEKB).2) Although the basic performance of theprevious SVD was satisfactory,3) further improvements
will be achieved in the newest version of SVD, SVD2.0,
installed in the summer of 2003.
Instead of the three layers in the previous version,
SVD2.0 consists of four concentric cylindrical layerswith a closer innermost layer (2.2 < r < 8.0 cm). It
contains 216 double-sided silicon strip detectors with
two orthogonal-coordinate readouts (110K channels in
total). The polar angle coverage is extended to be thenominal angular coverage of Belle. The front-end readout (VA1TA) chips are fabricated with 0.35 µm process
technology to improve radiation hardness (0.8 µm process technology in the previous version).
Considering there are 50% more readout channels
and increasing beam currents at KEKB, the trigger
rate is expected to rise up to 1 kHz; three times the
bandwidth of the previous version is required. We developed a new DAQ system for SVD2.0. For easier
implementation, handling and maintenance, we have
employed a new scheme based on standard PCs, instead of the Motorola DSPs used in the previous version.4) The detailed setup of SVD2.0 DAQ and thetrigger system can be found in Ref. 5.
The requirements for the new DAQ system are: toprocess data at a 1 kHz or faster, less than 5% ofdead time at 1 kHz trigger rate and a data-flow rate of
10 MB/sec. To achieve these requirements, the DAQ
system consists of 12 PCs (Xeon Pentium IV 2.4 GHzwith Intel Compilera) ) using PCI interfaces (P-PCI
boardb) ). The PCs receive event data from the flash
ADC system via P-PCI boards in LVDSc) and perform
data compression based on S/N ratio calculation andclustering.
The performance of the DAQ system has been examined with various occupancy levels (trigger rates)
emulated by a random-pulse generator. The DAQ system including the event builder is confirmed to be able
to process data at a 1.3 kHz trigger rate with 5% occupancy expected in SVD2.0. The total data size ismeasured to be 10.4 kB per event, which is manageable
for the Belle data storage. The dead time is measured
to be 5% at most under the same condition.
The trigger system has also been changed. To install the additional layer of SVD2.0, the innermost
cathode strips of the Central Drift Chamber (CDC)
had to be removed. They provided z (beam direction) information in the previous Level-1 (L1) trigger
to suppress the beam-related backgrounds. Considering the expected beam backgrounds, additional trigger
capability to compensate the loss of CDC z trigger isnecessary. Matching between CDC tracks and SVD
segment hits has been employed to maintain a reasonable trigger rate for hadronic triggers.
For the SVD L1 trigger, the 128-OR’ed fast-shaped(shaping time of 75 to 300 ns) signal (TA) of the
VA1TA chip is utilized. The SVD2.0 is divided into
18 track segments on the xy plane and coincidence
conditions based on 3 out of 4 layer hits are prepared.
The SVD-L1 logic is implemented using a VME
module containing XILINX FPGA. It receives 18 SVDsegment and 64 CDC-segment information and gives
the matching results with reasonable clustering to thefinal L1 decision. It contains not only matching logic
but timing adjustment, variable masks and a VME
control interface. The trigger decision is made within
1.7 µsec, satisfying the required latency of 2.2 µsec.
Initial performance has been checked with cosmicray muons and we found that the system operates
successfully. A typical event display is shown in
Fig. 1. Physics runs have just started with the complete SVD2.0 system and detailed performance analysis is being continued.

Fig. 1. Typical event of a cosmic-ray muon. Squares (circles) indicate the cluster hit of the cosmic-ray muon in
the forward (backward) side of SVD2.0. The thick lines
associated with ladders denote TA hits in VA1TA chips.

References
1) Belle Collaboration, S. Mori et al.: Nucl. Instrum.
Methods Phys. Res. A 479, 117 (2002).
2) KEK B Factory Design Report, KEK Rep. 95-7 (1995)(unpublished).
3) R. Abe et al.: Nucl. Instrum. Methods Phys. Res. A
478, 296 (2002); T. Kawasaki: Nucl. Instrum. Methods
Phys. Res. A 494, 94 (2002).
4) E. Banas et al.: Nucl. Instrum. Methods Phys. Res. A
469, 364 (2001).
5) K. Hasuko: RIKEN Accel. Prog. Rep. 36, 261 (2003).
a)
b)
c)

version 6
manufactured by Fird Corporation
Low-Voltage Diﬀerential Signal

261

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RIKEN Accel. Prog. Rep. 37 (2004)

Pumping 229m Th by hollow-cathode discharge
H. Haba, M. Hara,∗1 T. T. Inamura, Y. Kasamatsu,∗2 H. Kikunaga,∗3 T. Mitsugashira,∗1 T. Nakanishi,∗3
T. Ohtsuki,∗4 A. Shinohara,∗2 K. Takamiya,∗5 A. Yokoyama,∗3 and H. Yuki∗4
It was in 1976 that Kroger and Reich for the ﬁrst
time postulated the 1st excited state in 229 Th at an energy of approximately 100 eV or less.1) Eighteen years
later, Helmer and Reich revised such excitation energy
to 3.5 ± 1.0 eV.2) Meanwhile, Burke et al. suggested
the existence of such an isomer by observing the angular distributions of the 230 Th(d, t) 229 Th reaction.3)
Their results are, however, not direct evidence for suchan extremely low-lying isomer in 229 Th. Several attempts have been carried out to obtain direct evidence
for the isomer 229m Th. Because of its excitation energy
comparable to the UV, mostly optical measurement
has been carried out using 233 U that decays to 229g Th(and 229m Th probably) by emission of α particles.4–7)
None of these attempts have been successful. Recently,
two diﬀerent types of attempts have been carried out
to determine the lifetime of 229m Th by avoiding thehuge background inevitably caused by the parent nucleus 233 U.8,9) Unfortunately, their measurements areinconsistent with each other, and neither of them has
provided clear evidence for the existence of 229m Th.
Here, we present a unique combination of a noble
idea and the nuclear chemists’ expertise, aiming at unprecedented achievements in studying the exotic isomer 229m Th. The noble idea is to make use of a wellestablished technique, hollow-cathode discharge tube,
in atomic spectroscopy to populate the isomer in question; it is based on the Coulomb excitation of atomic
nuclei and hyperﬁne interaction which are basically described with the same form of Hamiltonian of electromagnetic interaction.10,11) Eventually, this idea has
been combined with Karpeshin’s theoretical proposal,11,12) optical pumping with lasers, which is practically impossible because of the large experimental error
in the excitation energy of 229m Th reported so far. In
the present method, by contrast, there is no need toknow exactly the excitation energies of atomic and nuclear states concerned. Now it seems very much probable to populate 229m Th through atomic states, andeven population inversion will be realized.12)
When we designed the hollow-cathode discharge
tube, we exercised special care to handle radioactive
229m
Th and 229g Th. A schematic cross-sectional viewof the tube is shown in Fig. 1. There is an empirical golden rule in designing to produce a well-localized
plasma in the hollow:13) the ratio of the length of the
∗1
∗2
∗3
∗4
∗5

Oarai Branch, Institute for Materials Research, Tohoku University
Graduate School of Science, Osaka University
Graduate School of Science, Kanazawa University
Laboratory of Nuclear Science, Tohoku University
Research Reactor Institute, Kyoto University

Fig. 1. Schematic cross-sectional view of our hollowcathode discharge tube. Discharge Ar gas will be kept
at a pressure of about 102 Pa. The discharge current
will be about 100 mA.

hollow l to its diameter φ, l/φ  4 and the gap d between the anode surface and the cathode surface should
be considerably smaller than φ. Our present measures
are l = 25 mm, φ = 5 mm and d = 1 mm. Cooling is effective not only for safety reason but also for localizing
the plasma in the hollow.
The experiment will be made at the Oarai facilityof Tohoku University with the world’s radiochemicallypurest 229 Th sample. This will be the ﬁrst backgroundfree measurement of α particles and photons from
229m
Th.
References
1) L. A. Kroger and C. W. Reich: Nucl. Phys. A 259, 29(1976).
2) R. G. Helmer and C. W. Reich: Phys. Rev. C 29, 1845
(1994).
3) R. G. Burke et al.: Phys. Rev. C 42, R499 (1990).
4) G. M. Irwin and K. H. Kim: Phys. Rev. Lett. 79, 990(1997).
5) D. S. Richardson et al.: Phys. Rev. Lett. 80, 3206
(1998).
6) S. B. Utter et al.: Phys. Rev. Lett. 82, 505 (1999).
7) R. W. Shaw et al.: Phys. Rev. Lett. 82, 1109 (1999).
8) E. Browne et al.: Phys. Rev. C 64, 014311 (2001).
9) T. Mitsugashira et al.: J. Radioanal. Nucl. Chem. 255,
63 (2003).
10) T. T. Inamura: Hyperfine Interact. 127, 31 (2000).
11) T. T. Inamura, F. F. Karpeshin, and M. B.
Trzhaskovskaya: Czech. J. Phys. 53, B 349 (2003).
12) F. F. Karpeshin et al.: Phys. Lett. B 372, 1 (1996).
13) B. Arcimowicz at Poznan Univ. Tech.: private communication.

263

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Study on beam instability due to space charge oscillation duringlongitudinal bunch compression
T. Kikuchi,∗1 T. Katayama, M. Nakajima,∗2 and K. Horioka∗2
Inertial conﬁnement fusion is one of the energy production methods by controlled thermonuclear reactions. In the heavy ion inertial fusion (HIF), the generation and transport of intense heavy-ion beams are carried out by a particle accelerator. The Pb, Bi, Hg, andU ions of 4–10 GeV particle energy are candidates.1)
The total beam current of 100 kA consists of many
heavy-ion beams, and the pulse width of 10 ns is required for the eﬀective implosion of a fuel pellet. In
the ﬁnal stage of the HIF accelerator system, the beampulse must be longitudinally compressed from ∼100 to∼10 ns. In the ﬁnal beam bunching, the beam current
is continuously increased due to the bunch compression, and the stability condition of the beam transport is also changed with increasing space charge effect. The bunch of heavy-ion beams should be transported and compressed without emittance growth andparticle loss as much as possible for the ﬁnal focusing to the target. However, these beam parameters
have not yet been determined, because such spacecharge-dominated beam dynamics could include many
unknown behaviors. Consequently, the study of highcurrent and space-charge-dominated beam is crucial in
HIF.
The beam dynamics was investigated during the longitudinal bunch compression in the ﬁnal buncher of the
HIF accelerator system.2–5) In this study, the pulse
width of the beam bunch is compressed from 250 to
10 ns, so that the beam current increases linearly 400 A
to 10 kA during the beam transport. For the simulation of the transverse beam dynamics during the longitudinal bunch compression, the transverse particle-incell method was used with a simple model of the beam
current increase.3) The dilution of particle distribution
in phase space was implied by the multiparticle simulation during the longitudinal bunch compression.2)
Figure 1 shows the evolution of the emittance growthratio /i , which is the ratio of the transverse rms emittance to the initial one, during the ﬁnal beam bunching along a number of lattice unit of 3 m length. The
Kapchinskij-Vladimirskij (K-V), waterbag, Gaussian,semi-Gaussian, and parabolic distributions were assumed as the initial conditions of the transverse particle distribution. As shown in Fig. 1, the K-V andwaterbag beams cause an abrupt emittance growth
due to the instability induced by the space charge
eﬀect.3,4) The particle simulations showed the emittance growth accompanied by localized charge distri∗1∗2

264

Center for Nuclear Study, University of Tokyo
Department of Energy Sciences, Tokyo Institute of Technology

Fig. 1. Emittance growth ratio during the ﬁnal beam
bunching. Each line corresponds to the diﬀerent initial distributions.

bution.3–5) It was found that the emittance growthindicated by Fig. 1 corresponds to the regime of thelarge growth rates of the axisymmetric ﬂute perturbation.3,4) The comparison with the analytical estimation
for the growth rate of the perturbation conﬁrmed theimportance of the role of space charge oscillation for
the emittance growth. On the other hand, the simulation results at the other distributions indicated thegradual emittance increase without abrupt growth.
In the present paper, the transverse beam dynamics
was investigated by the multiparticle simulation during
the ﬁnal beam bunching in the HIF accelerator. The
initially K-V and waterbag distributed beams caused
abrupt emittance growth due to the collective behavior of space-charge-dominated beams. On the other
hand, it becomes clear that the initial Gaussian, semiGaussian, and parabolic beams may pass through theﬁnal beam bunching region without the inﬂuence of
the instability induced by the space charge oscillation.
References
1) J. J. Barnard et al.: Nucl. Instrum. Methods. Phys. Res.
A 415, 218 (1998).
2) T. Kikuchi, M. Nakajima, and K. Horioka: J. Plasma
Fusion Res. 79, 105 (2003).
3) T. Kikuchi, M. Nakajima, K. Horioka, and T.
Katayama: accepted by Phys. Rev. Spec. Top. Accel.
Beams.
4) T. Kikuchi, M. Nakajima, K. Horioka, and T.
Katayama: Proc. 3rd Int. Conf. on Inertial Fusion Science and Applications, Monterey, USA, 2003-9, to be
published.
5) T. Kikuchi, T. Katayama, M. Nakajima, and K.
Horioka: Proc. 14th Symp. on Accelerator Science andTechnology, Tsukuba, 2003-11 (2003), p. 398.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Production of intense 58 Fe and 64 Ni beams using MIVOC method
M. Kidera, T. Nakagawa, Y. Higurashi, T. Aihara, N. Suzuki, E. Ikezawa,O. Kamigaito, M. Kase, and Y. Yano
In RILAC, super heavy elements 108, 109, 110
and 111 were intensively researched from last summer to this summer. For these experiments, very
stable and highly intense beams of 58 Fe and 64 Ni
were required to produce these super heavy elements
by using cold fusion reaction (58 Fr+208 Pb→267 108+n, 58 Fe+209 Bi →268 109+n, 64 Ni+208 Pb→271 110+ n,1)
and 64 Ni+209 Bi→272 111+ n2) ) which has a very small
cross section of the order of picobarns.
One of the useful methods for the production of
metal ion beams from ECRIS is the MIVOC method.
Using the MIVOC method,3) it is possible to produce
metal ions in the same manner as in the case of agaseous element. Various kinds of metal ions havebeen successfully produced thus far using the MIVOC
method from the RIKEN 18 GHz ECRIS. For theabove mentioned long-term experiments, we succeededin producing intense beams of 58 Fe and 64 Ni ions using
the MIVOC method.
In the MIVOC method, volatile compounds containg
metal atoms of interest in their molecular structure
were used to release metallic gaseous elements. These
compounds were placed in a separate vacuum chamber (MIVOC chamber) connected to the ECR plasmachamber. The compound vapor was allowed to diffuse into the plasma chamber. The MIVOC chamber was connected by a gas-feeding tube via a highly
conductive regulation valve to control the flow rate of
the compound vapor. Several 100 milligrams of thecompound powder was placed at the bottom of the
MIVOC chamber. Next, air and possible moisture in
the MIVOC were evacuated until the vapor pressure in
the MIVOC chamber become stable generally. With
the compounds, gas pressure in the plasma chamberincreased from ∼1 × 10−7 to ∼5 × 10−6 mbar. No gasmixing method was applied during the experiments. In
order to minimize contamination, the plasma chamber
wall was covered with a thin aluminum tube of 1 mm
thickness which is easily replaceable.
The 58 Fe ion was produced from ferrocene
58( Fe(C5 H5 )2 ) in the following manner. Collaboratingwith the chemical analysis division in RIKEN, about
200 mg ferrocene was produced from 100 mg of 91.5%
enrichment 58 Fe oxide. Constructive crystallization
was not carried out for the ferrocene; a compound oforganic chemicals was used. The color of the powder
was dark orange and the grain size was about 0.5 mm.
The consumption rate of 58 Fe was 1.2 mg/h during thebeam time of 77 hours. The average beam intensityof 58 Fe13+ was about 15 eµA at an extraction voltageof 15.9 kV. The RF power was 500 W. The typicalgas pressure was 2.4 × 10−6 Torr. The temperatureof the MIVOC chamber was controlled by the electric desk light, when the gas pressure was lower than
1.0 × 10−6 Torr.
The 64 Ni ion was produced from nickelocene64( Ni(C5 H5 )2 ) in the following manner. About 4 g ofnickelocene was produced from 3 g of 97% enrichment
64
Ni metal. Constructive crystallization was not carried out for the nickelocene. The color of the powder
was dark green, and the grain size was about 0.5–2 mm.
The beam times of 64 Ni14+ and 64 Ni13+ were about
400 and 2000 hours, respectively. 300–800 mg of nickelocene was placed in the MIVOC chamber once. The
average consumption rate of 64 Ni was about 1.2 mg/h.
The average beam intensities of 64 Ni14+ and 64 Ni13+
were about 17 eµA and 40 eµA, respectively.
The gas pressure of the plasma chamber is very sensitive to room temperature, because the vapor pressureof nickelocene is strongly dependent on it. The change
in gas pressure causes a rapid change in beam intensity. To minimize it, a new MIVOC chamber with

Fig. 1. Cross sectional view of new MIVOC chamber withtemperature control.
Table 1. Typical main parameters of RIKEN 18 GHzECRIS for the production of 58 Fe and 64 Ni using the
MIVOC method.
58

Fe13+

Max. mirror magnetic field (T)Microwave injection side
1.4
Beam extraction side
1.0
Gas pressure (Torr)
2.4e−6
RF power (W)500
Bias voltage of electrode (V)−64
Extraction voltage (kV)15.9
Beam intensity (eµA)
17

64

Ni14+

1.4
1.1
1.7e−6
450
−50
16.9
20

64

Ni13+

1.4
1.1
1.4e−6
500
−70
17.5
40

265

temperature control was developed for the 64 Ni13+ experiment. Figure 1 shows the cross sectional view of
the chamber. The chamber can be heated using a silicon rubber heater from room temperature to 70◦ C. A
Pt resistance thermometer was placed on the heater
to monitor the temperature. Gas pressure could becontrolled by the temperature of the MIVOC chamber easily. The beam intensity of 64 Ni13+ ions could
be stably kept at more than 30 eµA for a long term

266

operation.
The typical ECR parameters for the ferrocene andthe nickelocene are listed in Table 1.
References
1) K. Morita et al.: Eur. Phys. J. A, in press.
2) K. Morita et al.: submitted to J. Phys. Soc. Jpn.
3) T. Nakagawa et al.: Nucl. Instrum. Methods Phys. Res.
A 396, 9 (1997).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Optimization of magnetic field configuration for the production of
Ar ions from RIKEN 18 GHz ECR ion source†
Y. Higurashi, T. Nakagawa, M. Kidera, T. Aihara,∗ M. Kase, T. Kageyama, and Y. Yano
At RIKEN, the intense beams of multicharged heavyions, such as Ar8+ , Kr13+ , Xe20+ and U35+ , arestrongly in demand for the radioisotope beam (RIB)
factory project.1) For this reason, we constructed the
RIKEN 18 GHz electron cyclotron resonance ion source(RIKEN 18 GHz ECR ion source) in the mid-1990s andsuccessfully produced intense beams of heavy ions.
Very recently, with respect to increasing the beam
intensity from the ECR ion source, the importance ofthe magnetic ﬁeld conﬁguration and a few experimental results obtained using the superconducting ECR
ion source have been reported.2) In 2001, we measured the beam intensities as a function of the minimum magnetic ﬁeld strength of the mirror magnetic
ﬁeld (Bmin ) and the beam extraction side (Bext ) systematically for various heavy ions using the liquid-Hefree superconducting ECR ion source (RAMSES) at
RIKEN and SHIVA at the University of Tsukuba.3–5)
From these experimental results, we recognized that
it is important not only to increase the magnetic ﬁeld
strength, but also to optimize the magnetic ﬁeld conﬁguration to increase the beam intensity. In particular, the minimum magnetic ﬁeld strength (Bmin )of the magnetic mirror ﬁeld plays an essential rolein increasing the beam intensity. In these experiments, we observed the existence of an optimum value
for Bmin to maximize the beam intensity, and notedthat this value is independent of the charge state of
the heavy ions.3,4) The optimum value for Bmin was
0.47–0.49 T for 18 GHz (RAMSES) and ∼0.39 T for
14 GHz (SHIVA) for the production of various multicharged heavy ions. We also observed that the magnetic ﬁeld strength at the beam extraction side (Bext )aﬀected the plasma conﬁnement and the beam extraction conditions.4,5)
A detailed description of the RIKEN 18 GHz ECRion source and its present performances is given in
Ref. 6. The RIKEN 18 GHz ECR ion source has only
two sets of solenoid coils to produce the mirror magnetic ﬁeld. This means that we cannot control Bmin
and Bext , independently. When choosing the optimum
value for Bmin , Bext may not be optimum for the production of Ar ions.
To overcome this problem, with respect to the experimental results described in Ref. 3, we ﬁxed Bmin
to ∼0.48 T. Then we moved the plasma electrode position to maximize the extracted beam intensity. Figure 1 a) shows the magnetic ﬁeld conﬁguration for the†∗Condensed from the article in Nucl. Instrum. Methods Phys.
Res. A 510, 206 (2003)
SHI Accelerator Service, Ltd.

Fig. 1. a) Mirror magnetic field configuration for producing multicharged Ar ion beams; b) Schematic drawingof the plasma chamber around the plasma electrode position. Upper figure shows the magnetic mirror field of
this region.

production of multicharged Ar ions. For the plasma
conﬁnement, the eﬀective Bext should not be the maximum magnetic ﬁeld at the beam extraction side, but
the magnetic ﬁeld at the plasma electrode position
shown in Fig. 1 b). This means that the optimum value
for the eﬀective Bext for maximizing the beam intensity
is strongly dependent on the plasma electrode position.
The plasma electrode position also aﬀects the plasma
density at the electrode position7) and the beam extraction conditions.
Figure 2 shows the beam intensity of Ar9+ as a function of plasma electrode position. The extraction voltage was 14 kV. The microwave power was 500 W. The
plasma electrode position is deﬁned in Fig. 1 b). The
beam intensity gradually increases when moving theplasma electrode toward the ECR zone and then decreases as shown in Fig. 2. It seems that an optimum
plasma electrode position exists to maximize the beam
intensity of the multicharged Ar ions. Figure 3 shows
the optimum plasma electrode position for maximizing

Fig. 2. Beam intensity of Ar9+ ion as a function of plasma
electrode position. The plasma electrode position L isdefined in Fig. 1 b).

267

Fig. 3. Optimum plasma electrode position for maximizing
the beam intensity as a function of Ar ions.

the beam intensity of diﬀerent Ar charge state ions.
The optimum plasma electrode position moves toward
the ECR zone when the charge state becomes lower.
Figure 4 shows the strength of the eﬀective Bext andBmin for maximizing the beam intensities of Ar ionsas a function of the charge state. The eﬀective Bext
becomes higher as the charge state becomes higher.
This tendency is the same as that in the experimental
results obtained for the SHIVA ECR ion source.4) It
may be due to the eﬀect of the plasma conﬁnement,
which is dependent on the mirror ratio of the axial
magnetic ﬁeld strength.
Figure 5 shows the beam intensity of Ar8+,9+ ionsas a function of microwave power. For the productionof Ar8+ ions, the gas pressure of the plasma chamber was 4 × 10−6 Torr. Binj , Bmin and Bext were 1.4,
0.48 and 1.05 T, respectively. For Ar9+ ion production,

Fig. 5. Beam intensities of Ar8+,9+ ion beams as a functionof microwave power. The ion source is tuned at the
microwave power of 600 W.

the gas pressure was 2.2 × 10−6 Torr. The extraction
voltage was 17 kV. The ion source was tuned at a microwave power of 600 W for both cases. In this experiment, we only changed the microwave power without changing the other parameters (gas pressure, magnetic ﬁeld strength, extraction voltage and so on). It
should be noted that the beam intensities were notsaturated at the highest microwave power of 700 W inthis experiment. This suggests that we would obtaina higher beam current at a higher microwave power.
We successfully extracted 1.9 mA of Ar8+ and 1 mA of
Ar9+ at 700–800 W microwave power. Before tuning
Bmin , Bext and the plasma electrode position, we obtained only 1 mA of Ar8+ at the microwave power of
500–600 W.6)
We successfully increased the beam intensity of
Ar8+,9+ ions by optimizing Bmin , Bext and the plasma
electrode position. The beam intensity is strongly dependent on Bext and the plasma electrode position.
The optimum plasma electrode position moves toward
the ECR zone when the charge state becomes lower.
The optimum value of Bext increases when the charge
state becomes higher. The maximum extracted beam
intensities for Ar8+,9+ ions were 1.9 and 1 mA at 17 kV
extraction and the microwave power of 700–800 W, respectively.
References

Fig. 4. Optimum Bmin and Bext for production of Ar ionsas a function of the charge state of Ar ions.

268

1) Y. Yano: Indian J. Phys. 76S, 1 (2002).
2) D. Hitz et al.: Rev. Sci. Instrum. 73, 509 (2002).
3) H. Arai et al.: Nucl. Instrum. Methods Phys. Res. A
491, 9 (2002).
4) T. Kurita et al.: Nucl. Instrum. Methods Phys. Res. B
192, 429 (2002).
5) M. Imanaka et al.: Jpn. J. Appl. Phys. 41, 3926 (2002).
6) Y. Higurashi et al.: Rev. Sci. Instrum. 73, 598 (2002).
7) T. Nakagawa et al.: Jpn. J. Appl. Phys. 35, 4077 (1996).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Emittance measurement for intense beam ofheavy-ions from RIKEN 18 GHz ECRIS†
Y. Higurashi, T. Nakagawa, M. Kidera, T. Aihara,∗ M. Kase, and Y. Yano
Over the last decade, ECR ion sources (ECRIS) havebeen widely used as external ion sources for heavy-ion
accelerators. In particular, ECRISs have become oneof the key devices for the production of radio isotope
beams (RI beams). Since the mid-1990s, RIKEN has
undertaken the construction of a new accelerator complex for the RIKEN radioisotope beam factory (RIBF)
project.1) In this project, the production of intense
heavy-ion beams is an important factor in the generation of intense RI beams using projectile-like fragmentation. For these reasons, we tried to increase the beam
intensity of medium charge-state, heavy-ions, such as
Ar8+ , Kr13+ and Xe20+ , for the RIKEN RIBF project.
The ﬁnal goal of this project was to produce at least
1 pµA on target from the p to U beams. To meetthis requirement, we had to further develop the performance of the ECRIS. To increase the beam intensityfrom the accelerator, it is evident that the emittance isalso an important physical value for the ECRIS. The
emittance of the intense beam, e.g., 2 emA of Ar8+ ,should be enlarged by the space charge eﬀect. To investigate this eﬀect on the emittance and optimize thetransmission coeﬃcient of heavy-ion beams from the
RIKEN 18 GHz ECRIS to the heavy-ion linac, we measured the emittance of the intense beam under various
conditions.
A detailed description of the RIKEN 18 GHz ECRion source and present performances are described inRef. 2. A single 18 GHz, 1.5 kW klystron supplies microwave power to the source. The axial conﬁnementof the plasma is obtained by two solenoid coils, which
provide a magnetic mirror ﬁeld. The maximum power
consumption is 140 kW. The mirror ratio has a nominal
value of ∼3.0 with Bmax ∼ 1.4 T. The ﬁeld strength at
the surface of the hexapole magnets is approximately
1.4 T. Figure 1 shows a schematic drawing of the extraction system. The diameter of the plasma electrode hole and extraction puller are 10 and 16 mm,
respectively. The distance between the two electrods
used ranges from 15 to 30 mm. The typical extraction
voltage is from 10 to 20 kV. The typical beam intensity produced from RIKEN 18 GHz ECRIS is shownin Fig. 2. We successfully produced intense beamsof heavy-ions. For example, the beam intensities of
Ar8+ .3) Kr13+ and Xe20+ are 2.0 emA, 0.6 emA and
0.3 emA, respectively.
Figure 3 shows a schematic drawing of the experimental setup for measurement of the beam emittance.
As shown in this ﬁgure, we used a movable slit (deﬁn†∗

Condensed from the article in Rev. Sci. Instrum., in press
SHI Accelerator Service, Ltd.

Fig. 1. Schematic drawing of the extraction system of the
RIKEN 18 GHz ECRIS.

Fig. 2. Beam intensity of the Ar, Kr and Xe ions produced
from the RIKEN 18 GHz ECRIS.

Fig. 3. Schematic drawing of the beam analyzing and profiling system for the RIKEN 18 GHz ECRIS.

269

ing the beam position) and a movable thin wire (measurement of the beam position and intensity). The distance between the slit and the wire is 10 cm. We also
installed a solenoid coil between the ion source and analyzing magnet for focusing the intense beam. Figure 4
shows the typical beam emittance (y-y ) of Ar11+ ionsat an extraction voltage of 13 kV and an RF powerof 510 W. The extracted current (the current of extraction voltage power supply) and beam current (thecurrent of the faraday cup after the bending magnet)of Ar11+ ions were 4.1 mA and 170 eµA, respectively.
The ion beam emittance measurements in both thehorizontal and vartical planes were performed for awide mass range of ions. Figure 5 shows the normalized 99% emittance of the Ar8+ ions beam as afunction of the extracted current of the ion source. It
is clearly seen that the beam emittance gradually in-

Fig. 4. Typical beam emmitance (y-y ) of Ar11+ ions at an
extraction voltage of 13 kV and an RF power of 510 W.
The extracted current and beam current of Ar11+ ionswere 4.1 mA and 170 eµA.

creases from 0.5 to 1.1 πmm·mrad, with increasing extracted current from few mA to 14.5 mA. At a lower
extracted current (3–4 mA), 90% of the Ar8+ beam
could be accepted and acclerated by the RFQ linac
at an extraction voltage of 20 kV. At the highest extracted current (14.5 mA), we obtained 1.5 emA of the
Ar8+ beam from the ion source at 17 kV extraction
voltage. In this case, the beam emittance of Ar8+ was
420 πmm·mrad (unnormalized 99% emittance), which
is very large compared to the acceptance of the RFQ
linac (150 πmm·mrad). In order to accelerate the full
beam of 1.5 emA Ar8+ by RIKEN RFQ linac, we surely
need the extraction voltage of higher than 60 kV.
At lower extracted current, the emittance was almost independent on it. For example, the emittance of
Xe20+ ions were 0.47, 0.45 πmm·mrad for the extracted
current of 3.5 and 1.5 mA, respectively. The voltage ofthe extraction was 13.2 kV for both cases. It may suggest that such low extracted currents (≤ 3 mA) do notaﬀect the emittance very much.
We also measured the beam emittance of Ta20+ ionsusing the insertion method. The normalized beamemittance of the Ta20+ ions was 0.85πmm·mrad at theextraction voltage of 14 kV, which is very large compared with the Xe ions at almost the same extracted
current (∼2.9 mA). It is almost twice as large as that of
Xe20+ (the normalized beam emittance of Xe20+ ions
was 0.47 πmm·mrad). Usually, we have to insert the
Ta rod into the plasma deeply to produce Ta ions. because the melting point of Ta is very high (∼2800◦ C).
Consequently the plasma and beam intensity become
unstable. This instability may cause a large emittanceof the Ta beam. To understand the eﬀect of the instability of the plasma on the beam emittance, we need asystematic experiment for measurements of the plasma
instability (or stability of beam) and beam emittancesimultaneously.
References

Fig. 5. Normalized beam emittance (99%) of Ar8+ ions as
a function of extracted current.

2701) Y. Yano: Proc. 15th Int. Conf. on Cyclotron and Their
Applications, Caen, France, 1998-6 (IOP, Bristol, 1999),
p. 696.
2) T. Nakagawa and Y. Yano: Rev. Sci. Instrum. 71, 637(2000).
3) Y. Higurashi, T. Nakagawa, M. Kidera, T. Aihara, M.
Kase, and Y. Yano: Nucl. Instrum. Methods Phys. Res.
A, in press.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Control system for a Hyper ECR ion source
Y. Ohshiro,∗ S. Watanabe,∗ S. Yamaka,∗ and T. Katayama
In 1999, a Hyper ECR ion source was moved from
Tanashi to the RIKEN AVF cyclotron. The Hyper
ECR ion source and a 10 GHz ECR ion source havebeen operated to deliver the beams of gaseous1) andmetallic ions2) alternatively. The 10 GHz ion source
has been operated under an RARF control system.
This control system provides a sequence control system and a PC-based graphical remote control panel.
To facilitate the alternative operations of the two ion
sources, we improved the control system of the Hyper
ECR ion source because it was operated under a manual control system. A schematic of the new control
system is illustrated in Fig. 1. As shown in Fig. 1, thestandard voltages of the gas supply device, the power
supply of the RF ampliﬁer, and the exciting current
source of the mirror coil are controlled by a pair of analog digital (A/D) and digital analog (D/A) converters
regulated by the computer and sequencer.3)
A photograph of the control panel is shown in Fig. 2.
The output ranges of power supplies covered by thiscontrol system are tabulated in Table 1. The main parameters such as the electric current and voltage of thepower supply can be set on the graphical control panel.
The control panel enables us the speedy operation of
the Hyper ECR ion source in the manner similar to
the 10 GHz ECR ion source.
To achieve interlocking between measuring devices
such as a thermometer, cutoﬀ relay of cooling water,
vacuum gauge, power supply, and vacuum pumping
system, a touch panel (GOT) system is introduced inTable 1. Output ranges of power supplies.

Fig. 1. Schematic of the remote control system.

Power supply name
Mirror coil
RF amplifier
Extraction electrode
Einzel lensQuadrupole magnet
Analyzing magnet

Covering range
0 ∼ 600 A
0 ∼ 2 kW0 ∼ 50 kV
0 ∼ 20 kV
0 ∼ 20 A
0 ∼ 200 A

Fig. 2. Photograph of the control panel. (in Japanese)∗

Center for Nuclear Study, Graduate School of Science, University of Tokyo

271

Fig. 3. Display of the touch panel. (in Japanese)

the Hyper ECR ion source. This GOT system is independent of the remote control system as shown in
Fig. 1. Figure 3 shows the panel conﬁguration with adisplay of a vacuum operating system. It can be operated automatically under good interlock conditions.
In 2002, we completed the installation of a remote/local control system for the Hyper ECR ion source.
It enables the integration of all operating proceduresof the Hyper ECR ion source. We have been able tospeed up the operation with this system. Then, the272

ion source as well as the 10 GHz ECR ion source has
been routinely used for the delivery of multicharged
ion beams to the AVF cyclotron.
References
1) Y. Ohshiro et al.: RIKEN Accel. Prog. Rep. 36, 279(2003).
2) T. Teranishi et al.: CNS Annu. Rep. 2001, 7 (2002).
3) FX1s hardware manual, MITSUBISHI MELSEC-F.

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RIKEN Accel. Prog. Rep. 37 (2004)

Improvement of power supplies for RARF beam transport magnets
M. Nagase, N. Fukunishi, E. Ikezawa, M. Kase, and Y. Yano
Power supplies for the bending magnets in the
RIKEN Accelerator Research Facility (RARF) were
fabricated in 1988 and had been in operation without
any serious trouble. However, unstable behavior has
sometimes arisen in recent years due to deteriorationof circuit elements. In addition, stability of the output
currents is becoming increasingly important, because
recent unique experiments1) require beams with very
high precision, e.g., a parallel beam with an angulardivergence less than 10 microradians. Output-current
stability during an experimental program is crucial forsuch high-precision experiments. A sizable change ofbeam direction (100 microradians per day) was detected during an ion-channeling experiment. We hencemeasured the long-time stability of the output currents
and found that the instabilities of several power supplies were greater than 100 ppm per 8 hours, which isthe designed value.
Our detailed analysis revealed that the feedback control systems used to generate the constant output current encountered some trouble. The original feedback
control system is illustrated in Fig. 1. The output current is detected by the shunt resistor. The temperaturedependence of the shunt resistor is less than 10 ppm
per Kelvin and the shunt resistor is directly cooled bywater (35 ± 1◦ C) controlled by a water chiller. The
shunt resistor and related elements are put in the water, and their corrosion leads to the deterioration ofcharacteristics. On the other hand, DAC and DC ampliﬁer are contained in a box and heated using a thermostat oven. The average temperature in the box was
designed to be 45◦ C. However, surface temperaturesof several elements were found to be nearly 70◦ C. The
heat had also signiﬁcantly damaged several elements,

particularly chemical condensers and trimmer potentiometers. To solve the problems mentioned here, we
decided to adopt a DC current transformer (DCCT)
and a Peltier cooler, as shown in Fig. 2. The shunt resistor is replaced by the DCCT, which does not requirecooling water and is free from the corrosion problem.
The Peltier cooler holds the temperature of the DAC
and the DC ampliﬁer at 25◦ C. It is suﬃciently low to
avoid the heat-damage problem.
Modiﬁcation of power supplies was performed by
IDX Corporation during the routine maintenance period this summer. The fourteen power supplies listed
in Table 1 were modiﬁed. The DCCT and the Peltiercooler were set on top of the power supply. The DCCTs used here are products of HITEC,2) and their
speciﬁcations are listed in Table 2. Note that thetemperature dependence of the total feedback control system is determined not only by the temperature dependence of the output current of the DCCT(< 0.15 ppm/K), but also by that of the burden resistor monitoring the output current of the DCCT.
The temperature dependence of the burden resistor is
5 ppm/K, hence we include it also in the thermostat
chamber.
Because our modiﬁcations also changed the circuit
constants, careful tuning was required, particularly tosuppress hunching oscillations of output currents. The
total cost of the present modiﬁcations is roughly thesame as that to purchase two new power supplies.
The modiﬁed power supplies show suﬃcient longtime stability as shown in Fig. 3. The stability wasbetter than 10 ppm per 8 hours for all the modiﬁed
power supplies even when room temperature changed
from 28◦ C to 25◦ C during the measurement. The measured stability corresponds to one-tenth the originalvalue. There are two additional merits. First, the wa-

Fig. 1. Schematic diagram of feedback control system of
the power supplies before modification. Trimmer potentiometer is abbreviated TP.

Fig. 2. Schematic diagram of feedback control system of
the power supplies after modification. The abbreviation‘BR’ indicates a burden resistor.

273

Table 1. List of power supplies modified in the present work. Under the “Type” column, SR and TR
indicate saturable reactor and transistor type, respectively. Values of stability listed here are designed
values before modification.

Table 2. Specifications of DCCT used in the present modification.

Fig. 3. Stability of power supplies modified here.

present success is a good example of improving thelong-time stability of old-fashioned power supplies atreasonable cost.
ter chiller that requires routine maintenance becomes
unnecessary. Secondly, power consumption was reduced by 6 kW because the shunt resistors were nolonger used.
The remaining power supplies in RARF are also oldfashioned and will suﬀer from the aging problem. Our

274

References
1) Y. Nakai et al.: RIKEN Accel. Prog. Rep. 36, 96 (2003);
Nucl. Instrum. Methods Phys. Res. B 205, 784 (2003).
2) MACCplus : http://www.ppm.co.uk/HITEC37.htm

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RIKEN Accel. Prog. Rep. 37 (2004)

Design of vacuum pumping unit for RIBF beam transport lines
S. Yokouchi, M. Fujimaki, M. Hemmi, H. Isshiki,∗ M. Nishida,∗ K. Oyamada,∗ and M. Kase
The vacuum pumping unit (VPU) for the RIBF
beam transport (BT) lines has been developed. The
VPU is composed of a turbomolecular pump (TMP),
pneumatically driven gate valves, vacuum gauges, a local controller, and other vacuum components, and isconnected to the beam diagnostic chamber of the BT
line in sections that are divided by φ63 mm gate valves(GV1, GV2) (see Figs. 1 and 2).
We selected a TMP ﬁtted with grease-lubricated ballbearings, which has net pumping speed of 210 L/s forN2 . The TMP is designed to be connected to the beamdiagnostic chamber at an installation angle of 45◦ , asshown in Fig. 2, since the grease-lubrication-type TMP
can be operated in any orientation. If the TMP isconnected to the bottom of the chamber (vertical attitude), the maintenance of the TMP would be very
inconvenient because of the limited space, and if the
TMP is connected to the side or top of the chamber(horizontal or upright attitude), it would be very diﬃcult to carry out the alignment of BT line because theFig. 1. Typical configuration of the VPU for BT lines.

TMP would interfere with the sighting of marks on thechamber.
The TMP is designed to be connected close to thebeam diagnostic chamber via a φ100 mm gate valve(VH) so that the eﬀective pumping speed at the chamber is more than 150 L/s. For example, if an aluminum alloy beam duct of φ62 mm × 10 m, whose outgassing rate after 100 hours of pumping is estimated to
be about 1 × 10−7 Pam3 /s/m2 ,1) is evacuated by this
TMP, the average pressure along this duct is calculated
to be less than 7 × 10−6 Pa. In practice, the gas loadof the chamber and diagnostic devices, which are under development, must also be considered. Even if thegas load is ﬁve times as much as that of this duct, theincrease in pressure due to it is about 6 × 10−6 Pa at
most, and therefore the actual average pressure along
this duct is expected to be less than 2 × 10−5 Pa. For
this pressure range, the beam transmission in a BT line
is expected to be more than 99%, assuming a cross section of 1×10−16 cm2 and a beam path length of 100 m.
A set of one cold cathode gauge (PE1) and two Pirani gauges (PI1, PI2) is employed for the VPU in consideration of reliability and durability. By using thesegauges, various signals of vacuum pressure for monitoring and interlocking are transmitted to the local
controller and/or the control system.
Each VPU has a local controller for itself. Everycomponent of the VPU can be locally operated andmonitored at the controller according to sequence programs. Furthermore, both operation and monitoringof VPU components can be carried out remotely fromthe control console via an N-DIM interface card.2) The
controller of one VPU is hard-wired with that of theadjacent VPU’s to interchange the vacuum conditions
for the operation of the GV1 (GV2).
We constructed a test bench of the VPU (see Fig. 2).
The programs of the local controller were checked using this test bench. The vacuum chamber in Fig. 2,
which was developed for the aluminum alloy beam diagnostic chamber for BT lines, involves two important
techniques. One is precise electron beam (EB) weldingof aluminum alloy, and the other is hardening of theseal surface of a knife edge ﬂange made of aluminumalloy by melting copper into the base material with the
EB. For the former, an accuracy within 0.2 mm was
obtained in this work. The latter is being tested forevaluation.
References

Fig. 2. Photograph of VPU test bench equipped with all
VPU components except GV1 and GV2.
∗

1) S. Yokouchi et al.: Proc. EPAC ’90 (1990), p. 1332.
2) M. Fujimaki et al.: RIKEN Accel. Prog. Rep. 37, 279(2004).

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RIKEN Accel. Prog. Rep. 37 (2004)

Longitudinal emittance measurement of the RRC beam
R. Taki,∗1 H. Okamura,∗2 N. Sakamoto, N. Fukunishi, H. Ryuto, K. Sekiguchi, and A. Goto
The correlation between kinetic energy and time
spreads, i.e., the longitudinal emittance, which is indispensable information for the operation of the RIBF,
has been measured for the 3800-MeV 40 Ar beam fromthe RIKEN Ring Cyclotron (RRC). Because of the sinusoidal radio frequency (RF) ﬁeld, the correlation is
expected to have a quadratic form, T (φ) = T0 cos φ 
T0 (1−φ2 /2), where φ = 2πfRF t. To cover the wide
range of acceleration phase, the measurements weremade by displacing the injection phase relative to theRF, ∆φinj , from −6◦ to +4◦ at a step of 2◦ (198 ps
for fRF = 28.1 MHz). Also, the eﬀect of phase compression in the RRC was observed. A radially increasing voltage distribution of the RF compresses
the beam bunch size.1) The eﬀect is formulated as∆φext = ∆φinj Vinj /Vext and Vinj /Vext = 1.6 for thepresent experiment.
The experiment was carried out in the E4 experimental area using the magnetic spectrometer
SMART.2) The beam accelerated by the AVF cyclotron and the RRC was transported to the scattering chamber. Particles were elastically scattered by a
25 µm gold target, collimated at θ = 2◦ with an angular acceptance of 12 mrad, momentum-analyzed by
the SMART and detected at the second focal planeby two plastic scintillation counters followed by a silicon position-sensitive detector (Si-PSD). The position resolution of Si-PSD was 1 mm and the time
resolution of a pair of plastic scintillators was 100 ps(FWHM). Since the momentum dispersion of the
SMART is −77 mm/%, the relative energy resolution
is estimated to be 2.5 × 10−4 . Energy spreads fromenergy-loss straggling in the target and kinematicalbroadening by the angular acceptance are negligibly
small. The momentum dependence of time-of-ﬂight
from the RRC to the detector was corrected according to δt/t0 = [−γ −2 +(∂L/L0 )/(∂p/p0 )] δp/p0 , where
L0 = 89.5 m. ∂L/(∂p/p0 ) was determined to be−355 mm/% so that the shift of time spectrum is proportional to the shift of injection time.
Figure 1 shows the result of longitudinal emittance.
The quadratic correlation is clearly seen, but smeared
by a fairly large spread of distribution. Particularly,
the time spread, 700 ps (FWHM), is much larger than
expected from both the detector resolution and acceleration mechanism. Its origin must be further studied.
The extraction phase with respect to the RF, ∆φext ,has been deduced from the centroid of the projected
time spectra. The diﬀerence, ∆φext −∆φinj , is plotted
as a function of ∆φinj in Fig. 2. The data approxi∗1∗2276

Department of Physics and Astronomy, Michigan State University, USA
Cyclotron and Radioisotope Center, Tohoku University

Fig. 1. Longitudinal emittance for various injection phases.
The parabolic curve represents the RF.

Fig. 2. Shift of time spectra relative to the injection(∆φext −∆φinj ) plotted as a function of the shift of injection (∆φinj ).

mately lie on a straight line expected from the phase
compression eﬀect, but the deviation indicates a higher
order eﬀect, the origin of which is a future problem.
References
1) W. Joho: Part. Accel. 6, 41 (1974).
2) T. Ichihara et al.: Nucl. Phys. A 569, 287c (1994).

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RIKEN Accel. Prog. Rep. 37 (2004)

Expansion of the control system for RARF
M. Kobayashi-Komiyama, I. Yokoyama, M. Fujimaki, J. Odagiri,∗ T. Tanabe, and M. Kase
The basic operations of the RIKEN Accelerator Research Facility (RARF) are currently carried out by
using the Experimental Physics and Industrial Control System (EPICS)1) without any serious problems.2)
For more stable beam operation and system expansion
gazing at the RIKEN radioisotope (RI) Beam Factory(RIBF) control, we carried out two important improvements of the EPICS control system last summer.
The ﬁrst one is the EPICS upgrade. We replaced the
EPICS base programs running on the server computerfrom R3.13.1 to R3.13.8. The reason why we selected
EPICS base R3.13.8 was that it was the latest andmost stable version at that time. By this upgrade, we
can expect more stable beam operation. This was our
ﬁrst experience at renewing the base programs since
we started using EPICS in our control system approximately four years ago. When we renewed the server
computer about two years ago, we copied only the binary codes of the base programs from the old server
computer and installed them on the new server computer. Unfortunately, it caused one problem, which
was just the reason for last summer’s EPICS upgrade.
The problem is that we could not install recent application programs supported by the EPICS community
in our system. The reason for this problem was considered to be due to some kind of mismatch between theold base programs and new application programs. By
compiling the base programs on the server computerfrom scratch, we could add new functions to our con-trol system. For example, we could install a timestamp
record in our applications, which has made it very convenient to record a history of beam operation by usinggraphs and GUIs.
The second improvement is the system expansion.
For the control of RIBF components, it was decided
to introduce two types of Ethernet-based control interfaces into the EPICS control system. One is Programmable Logic Controller (PLC), which controls theRF system of cyclotrons and so on. The other one
is Network-Device Interface Module (N-DIM), which
is our original control device, developed to substitutefor the CAMAC-CIM/DIM system.3) As shown in Table 1, N-DIM will be used for various purposes in the
RIBF control system; to control all beam diagnostic
equipment, all vacuum systems, the driving system fordeﬂectors and so on. Furthermore, it is also planned
to replace the CAMAC-CIM/DIM in the RARF with
N-DIM gradually. Thus, we need to develop an N-DIM
driver software to control them in EPICS.
We started to investigate how to develop the EPICS
driver software for N-DIM in the summer of last year.
We have already developed the EPICS driver software
to control the OMRON PLC, CS1 last year and wehave obtained data from them by using it. Thus, it isexpected that it will not be diﬃcult to develop driver
software for N-DIM because it is a network controller
as well as CS1. However, it is not a good idea todevelop the driver software for N-DIM by the same

Table 1. Interface devices in RARF/RIBF.

∗

High Energy Accelerator Research Organization (KEK)277

method as that for CS1 because our method does nothave the framework of EPICS for asynchronous I/Otransactions. It is better to have an asynchronous
driver for N-DIM because of the wait of a few moments
to receive data from a beam diagnostic device. In otherwords, it is not a good idea to wait for a few moments
in one task because it stops the ﬂow of all tasks in Input Output Controller (IOC) during data acquisition.
Thus, we decided to develop the driver software thathas an asynchronous framework from scratch.
We developed a set of device/driver support modules for the EPICS to support N-DIM with the KEK
control group. They also have an original controller
based on Ethernet and the timing was matched for development of their driver software and for our requirements. Furthermore, we had a common requirement
to control some kinds of PLCs as well as our original Ethernet-based controllers. We considered that
it is essential that the drivers share as much of theircodes as possible with suﬃcient ﬂexibility for adapting
to various proprietary communication protocols. Finally, the software consists of a common driver module, a common device support module, and a devicespeciﬁc module for each of the devices to be supported.
The common driver module encapsulates the details of
the programming for communication over the network.
The common device support module encapsulates thedetails of the framework of EPICS for asynchronous
I/O transactions. We decided to implement the common modules in such a manner that the device speciﬁc
modules can be implemented by using only standard
UNIX libraries. As a result, it turned out that the developed device speciﬁc modules were compliant withboth EPICS R3.13 on VxWorks and R3.14 on Linux.4)
We started to develop driver software for Yokogawa
PLC, FA-M3 at ﬁrst because a large amount of FAM3 would be used in the J-PARC project and we had
an FA-M3 using for a test.
The development of the driver software was completed last summer. As for N-DIM, the device-speciﬁc
module was developed from scratch, since it adopts
the ASCII code, which was not used in any other software. It is conﬁrmed that N-DIM operates in boththe EPICS R3.13 on VxWorks and R3.14 on Linux
environments. For R/D of the system, we newly introduced EPICS R3.14.1 on a Linux PC (Redhat 8)
into the EPICS control system last summer to control
nine N-DIMs installed in the new vacuum system in
RILAC. The remarkable feature of the EPICS R3.14
on Linux PC system is that the Linux PC functions
both as an operator interface and IOC in a control
system, thus we can construct an EPICS control system solely by using it instead of a server computer and
VxWorks on a VME computer. Therefore, we can de-278velop the N-DIM control system independently fromthe current control system of RARF. It was a significant advantage for us. In the current status, thoughsome drawbacks of N-DIM itself were pointed out; nocommunication problems occurred under the condition
that all N-DIMs scan all their digital and analog input(DI/AI) ports every 0.1 second. On the other hand,
the Linux server PC also controls PLCs. There is aswitch box controlled by FA-M3, and the new RF system in RILAC controlled by Omron PLC, CS1. The
software for the CS1 was prepared very easily by usingthat for FA-M3 as a template.
In the RIBF, more than one hundred N-DIMs will be
used to control the accelerator components. There are
two candidate server computers in the current status,
the HP-UX server and Linux server. Advantages anddisadvantages of both systems are as follows;
Advantage of HP-UX server with EPICS R.3.13.8:• Easy. Solely the adding of another VME to theexisting control network enables the system extension.
Disadvantage of HP-UX server with EPICS R.3.13.8:• When we add a new VME into the system, thelicense cost of the VxWorks is very high.
Advantage of Linux server with EPICS R.3.14.1:• Cost-eﬀective.
• It can be constructed independently from the current HP-UX system. In other words, multiple control networks divided into control blocks can exist
in the system independently.
Disadvantage of Linux server with EPICS R.3.14.1:• Diﬃcult to maintain due to the high frequency of
upgradation of its kernel version.
We have to select the server carefully by considering its
functions, stability and future maintenance. We will
examine the performance of both systems and choose
the server machine for N-DIMs and PLCs in the near
future.
References
1) http://www.aps.anl.gov/epics/2) M. Kobayashi-Komiyama et al.: RIKEN Accel. Prog.
Rep. 36, 281 (2002).
3) M. Fujimaki et al.: RIKEN Accel. Prog. Rep. 37, 279(2004).
4) J. Odagiri et al.: Proc. 9th Int. Conf. on Accelerator and Large Experimental Physics Control System(ICALEPCS 2003), Gyeongju, Korea, 2003-10, in printing.

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RIKEN Accel. Prog. Rep. 37 (2004)

N-DIM as controller of devices for beam transport
M. Fujimaki, M. Kobayashi-Komiyama, I. Yokoyama, and M. Kase
A new control unit of N-DIM (shown in Fig. 1) has
been developed for the devices installed in the beamtransport of the RIBF. The control objects are thebeam monitors such as Faraday cups and a beam profile monitors, and the vacuum pumping devices. A
number of control units called DIM (the device interface module) have been used for the control of theabove devices in the RARF. Because they are very old,
it is unfavorable to extend the old DIM to the controlof the new devices of the RIBF.
Considering the inconvenience associated with theold DIM, the new control unit of N-DIM was designedon the basis that the total control system would become very simple. To realize this, a communication interface between the N-DIM and an operation computeris made via an Ethernet network (general 10BASE-T/
100BASE-TX). The N-DIM can be operated directlyfrom other computers, even from other N-DIMs. thisis a why the new unit was called as N-DIM (network
DIM).
A block diagram for N-DIM is shown in Fig. 2. For
the CPU, we used the SH4 fabricated by HITACH,
which is equipped with two kinds of memories (6 MB
RAM and 1 MB ROM). The control software was produced in the µiTRON embedded on the N-DIM. We
prepared approximately 20 command words consistingof three ASCII characters to be used in the operationof N-DIM. Moreover, the system may also be operated
by logging in with telnet.
N-DIM is controlled by the socket connection ofFig. 2. Block diagram.

TCP/IP. The acquired data are sent to the control
system inside the answer sentence of TCP/IP. Whendata are acquired continuously, they are sent in two
ways. The data are stored as a file in the memory of
the N-DIM and taken by the FTP connection, or suchdata, in units of small packets, can be sent by UDP/IP

Fig. 1. N-DIM.

279

in the real-time scheme.
Whenever the N-DIM is switched on, it tries to connect to the application server, and an executive code
is downloaded from the server by FTP. Using thisfunction, new commands can be easily added to the
N-DIM.
It is supposed that the N-DIM will be used for environmental radiant rays. S-RAM and EP-ROM are
selected for the main memory. They have high tolerance to radiation in comparison with D-RAM andFlash-ROM. Besides, the clock of the CPU is used ata lower frequency than standard one, and the voltagesof the data bus and the address bus are high in order
to raise the noise margin.
The N-DIM has the following input and output specifications.
(1) 32 ch digital inputs isolated with photocoupler(2) 32 ch digital outputs isolated with photocoupler(3) 16 ch analog inputs (14 bit accuracy and 200 kS/s
sampling)

280(4) 8 ch Interrupt Inputs with photocoupler
The hardware connections of inputs and outputs arecontrolled by a logic circuit using FPGA. If necessary,
the functions of inputs and outputs can be changed by
the program on the FPGA. These functions can also
be made compatible to the DIM using this program.
The future exchange of the DIM, which will lose its
usefulness soon, with the N-DIM is kept in mind. Theinterrupt inputs in item (4) can control some of thedigital outputs directly. They can be used for interlock,for example. An additional circuit for the hardwareinterlock is unnecessary between the N-DIM and thecontrolled device.
A prototype of the N-DIM was produced in 2002
and a fundamental testing was carried out. In 2003,
twenty sets of N-DIMs were fabricated. Some of themwere installed on the beam line of RILAC to control avacuum system and a beam profile monitor and a fieldtest is now underway. About one hundred N-DIM units
will be used in the RIBF.

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RIKEN Accel. Prog. Rep. 37 (2004)

HIS:The radiation safety interlock system for the
RIKEN RI Beam Factory
H. Sakamoto, S. Ito, T. Yamaki, S. Fujita, Y. Uwamino, and M. KaseTo ensure radiation protection at the RIKEN RI
Beam Factory, two interlock systems will be installed. One is a radiation safety interlock system, HIS(Houshasen [which means “Radiation” in Japanese] Interlock System) which controls the radiation safety devices, and the other is BIS (Beam Interlock System)
which protects the accelerator and the beam-line components. Their conceptual diagram is shown in Fig. 1.
The devices for human safety are doubly monitored by
the two systems independently. The beam will be immediately stopped, within 1 second, when either system detects any abnormality.
HIS was developed in 2003. This system initializes
and controls all the devices connected to it, namely,
radiation shutters, beam stoppers, radiation area monitors, shielding doors, beam status indicator, alarmsiren, and so on.
HIS consists of five I/O stations and two personal
computers (PCs). Figure 2 shows the concept. Eachstation has a programmable logic controller (PLC)
which includes digital outputs, digital inputs and analog inputs. The concerned devices send their status
to the five PLCs and receive the control signals fromthem, which are installed nearby. Actually, these signals connect the I/O boards of PLCs through multiconnectors. The use of connectors facilitates connection and disconnection of the station when we repair
or test the system.
The stations are doubly connected between them via
optical fibers. Moreover, one of the stations is also

Fig. 2. Schematic of HIS.

Fig. 1. Conceptual diagram of two interlock systems.

281

connected to a PC through the Ethernet. The PC isable to display the status of the whole system or of
setup functions. The I/O record and the trend of theanalog signals are saved and displayed on the PC. We
can actually install the functional program ROMed on
the PLC to improve the system reliability.
At the same time, we developed a testing apparatus
that simulates the devices concerned that will be installed in the RIBF accelerator building. Due to this282

apparatus, the debugging of the system logic can be
performed before the construction of the whole system.
Henceforth, we have to verify the soundness of HIS
and prepare the expansion of this system so that we
can use it for the radiation control of the RIBF buildings. The expanded complete system will be installedin the RIBF accelerator and experiment buildings in2005 at the earliest.

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RIKEN Accel. Prog. Rep. 37 (2004)

Charge strippers for the RIKEN RI-Beam Factory
H. Ryuto, N. Inabe, N. Fukunishi, H. Hasebe,∗ S. Yokouchi, M. Kase, A. Goto, and Y. Yano
A charge stripping scheme of the RIKEN RI-Beam
Factory (RIBF) was presented in the previous report.1)
According to the design modifications of the beamtransport line from the RIKEN ring cyclotron (RRC)
to the intermediate-stage ring cyclotron (IRC) via
the fixed-frequency ring cyclotron (fRC), the stripping
scheme was slightly changed. The points of change aredescribed below. Experimental data on the chargestate distributions of 136 Xe at 39 MeV/nucleon are alsopresented and compared with calculation values.
The third stripper section in the previous stripping
scheme was planned to be used in both cases whereions are accelerated with the fRC and without the fRC.
In the modified design (Fig. 1), the beam transportline from the fRC to the IRC does not pass throughthe previous third stripper section. Accordingly, thesection previously numbered as third was renumbered
as fourth, and the third stripper section was placed
between the fRC and the IRC anew. The new third
stripper section is used in the case only with the fRC,
and the fourth stripper section is used in the case only
without the fRC. The strippers placed at the new thirdand fourth sections are mainly characterised by the
thicknesses of carbon foils and plates. As describedin the previous report, uranium and xenon ions areplanned to be stripped at the third stripper section by
14 mg/cm2 and 20 mg/cm2 thick carbon plates, respectively. On the other hand, the thickness of the stripper
at the fourth section is required to be small in order
to avoid a large energy loss aiming at the incident energy range of the IRC. Xenon ions are planned to be
stripped by a 0.3 mg/cm2 thick carbon foil (see below
for details). A rotating carbon disk stripper for thethird section is currently under development.
The charge-state distributions of 136 Xe at 39 MeV/

nucleon, which corresponds to the incident energy ofthe fourth stripper section, were measured with strippers of various thicknesses. The xenon beam was bombarded on carbon foils, aramid films, and a polyimide
film with thicknesses from 80 µg/cm2 to 7 mg/cm2 .
Figure 2 shows the measured charge-state fractions.
Solid and dashed lines indicate the GLOBAL2) andETACHA3) calculations, respectively. Comparing the
calculation values to the data, it is seen that the
GLOBAL calculation well reproduces the data compared to the ETACHA calculation. According to the
GLOBAL calculation, we can obtain 136 Xe45+ by a
0.3 mg/cm2 thick carbon foil with a 26% fraction.

Fig. 2. Charge-state fractions of 136 Xe at 39 MeV/nucleon
stripped by carbon foils, aramid films, and a polyimide
film. Horizontal and vertical axes indicate the thicknessof the strippers and the charge-state fractions, respectively. Vertical cross, diagonal crosses, open diamonds,
open squares, circles, solid diamonds, and solid squareindicate the measured charge-state fractions from 47+
to 53+. The charge-state fractions are normalised by
the area of the Gaussian fitted to the measured chargestate distribution. Solid and dashed lines indicate thecalculations by GLOBAL and ETACHA, respectively.

References
1) H. Akiyoshi, N. Inabe, N. Fukunishi, H. Hasebe, T.
Chiba, M. Kase, and Y. Yano: RIKEN Accel. Prog.
Rep. 36, 292 (2003).
2) C. Scheidenberger, Th. Stöhlker, W. E. Meyerhof, H.
Geissel, P. H. Mokler, and B. Blank: Nucl. Instrum.
Methods Phys. Res. B 142, 441 (1998).
3) J. P. Rozet, C. Stéphan, and D. Vernhet: Nucl. Instrum.
Methods Phys. Res. B 107, 67 (1996).
Fig. 1. Schematic of the RIBF.
∗

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RIKEN Accel. Prog. Rep. 37 (2004)

Low-power test of the IRC flattop resonator
N. Sakamoto, O. Kamigaito, S. Kohara, A. Goto, and Y. Yano
The flattop resonator for the IRC (Intermediatestage Ring Cyclotron)1) has been constructed and lowpower testing was carried out. The required frequency
range and the maximum gap voltage of the resonatorare from 72.0 to 121.5 MHz and 150 kVp , respectively.
A schematic of the resonator is shown in Fig. 1. The
resonator is a single-gap type whose resonant frequency
varies by two movable shoring plates. The shape ofthe resonator was designed and optimized by using thecomputer code MAFIA.
Figure 2 shows the resonant frequency of the fundamental mode. As shown in the figure, the movementof the shorting plates by a stroke of 790 mm varies theresonant frequency from 69 to 123 MHz. The resonant
frequency predicted by MAFIA is lower than the measured frequency by 2% in the entire frequency range.
The second and third higher modes appear around 120
and 190 MHz, respectively. The block tuner varies theresonant frequency by more than 0.5%.
Q-values and parallel shunt impedance (Rs) are
shown in Fig. 3. They are as large as 73% of thecalculated values. Rs values are obtained by electric-

Fig. 2. Resonant frequency of the fundamental mode.

Fig. 3. Q-values and parallel shunt impedance.

field measurement using a perturbation method. At
a frequency of 109.98 MHz, in the case of uranium
350 MeV/u acceleration, the wall loss is estimated to
be 16 kW with a gap voltage of 150 kVp .
References

Fig. 1. Schematic of the IRC flattop resonator.

284

1) N. Sakamoto et al.: Proc. 16th Int. Conf. on Cyclotrons
and Their Applications, East Lansing, USA, 2001-5(American Institute of Physics, 2001), p. 306.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Status of booster ring cyclotrons for the RIKEN RI Beam Factory
A. Goto, H. Okuno, J. Ohnishi, N. Fukunishi, T. Tominaka, S. Fujishima,∗1 K. Ikegami,
N. Sakamoto, N. Inabe, Y. Miyazawa, S. Yokouchi, T. Fujinawa, T. Mitsumoto,∗2
O. Kamigaito, H. Ryuto, H. Mikami,∗2 M. Kase, and Y. Yano
In this report, the construction of a chain of booster
ring cyclotrons consisting of the fRC, IRC and SRC for
the RIKEN RI Beam Factory is described.
For the SRC, the fabrication of almost all its main
components was completed in the spring of 2003 asscheduled. All the main coils (twelve sets) and trim
coils (twenty-four sets) were fabricated within tolerances of ±1 mm and ±2 mm, respectively, for the positions of the centers of their cross sections. The stabilityof the power supplies for the main coils and trim coils
was within 5 ppm per 8 h. The resonant frequencies
and Q-values of the rf resonators were measured at
the factory; the measured resonant frequencies were inagreement with the MAFIA calculation within 1%, andthe Q-values were 70–80% of the calculated ones in theentire frequency range. Figure 1 shows a photographof the inside of the control Dewar vessel fabricated at
the factory.
From the spring to the summer of 2003, all the completed components of the SRC, except for the coldmass such as the main coils and trim coils as wellas warm poles, were delivered to the new accelerator
building of RIKEN. More than 400 iron pieces for theyokes and magnetic shields (about 6,300 t in total) are
now laid on the floors of both the SRC vault and the
Big RIPS room. The cryostats and the control Dewar
vessel are in the Big RIPS room. The power supplies
for the sector magnets are set at the due places. The
cryogenic cooling system consisting of one He refrigerator, three compressors and four reservoir tanks for
He gas is also set in their proper places. The lower

Fig. 1. Photograph of the inside of the control Dewar vessel
being fabricated at the factory. The main coils and trim
coils for the six sector magnets are connected in series.
∗1∗2

Ishikawajima-Harima Heavy Industries Co., Ltd.
Sumitomo Heavy Industries, Ltd.

yokes and lower magnetic shield plates for one sector
magnet were assembled in their proper places in the
SRC vault. Figure 2 shows a photograph of the SRC
vault that was taken in July 2003.
The completed superconducting bending magnet(SBM) for beam injection was tested at RIKEN in theautumn of 2003. It took about 100 h to cool the coldmass down from room temperature to 4.3 K. The SBM
reached the designed field of 3.8 T in one quench. Magnetic field distributions along the beam axis were alsomeasured.
In October 2003, the plumbing of the lines for the
He refrigerator, compressors and reservoir tanks wasstarted in the accelerator building. The assembly of
the cold mass, e.g., the attachment of the trim coil vessel, the 70 K thermal shields, temperature sensors, andstrain gauges, to the main coil vessel was also started
at the factory. The lower yokes and lower magnetic
shields for the remaining five sector magnets are scheduled to be completed in the spring of 2004.
The installation and assemby of the IRC sector magnets were started in October 2003. For one and a halfmonths, the lower parts including the yokes, poles,
main coils, trim coils and beam chambers were assembled for all the four sector magnets. The sector magnets were set with an accuracy of 0.2 mm inboth the horizontal and vertical directions. Figure 3
shows a photograph of the IRC vault that was taken
in November 2003. The assembly of the remaining upper yokes and the installation of the rf resonators arescheduled to be completed by the end of 2003. The
rf characteristics of the flattop resonator were mea-

Fig. 2. Photograph of the SRC vault that was taken in July
2003. The assembled lower yokes and lower magnetic
shields for one sector magnet can be seen along withsome of other components temporarily delivered.

285

Fig. 3. Photograph of the IRC vault that was taken in
November 2003. The lower parts have been assembled
for all the four sector magnets.

sured at the factory; the measured resonant frequencies
were higher than the MAFIA calculation by 2%, andthe Q-values and shunt impedances were about 70% of
the calculated ones in the entire frequency range.
An order was given to Sumitomo Heavy Industries,
Ltd., regarding the fabrication of the fRC. As of
November 2003, the machining of the yoke and polepieces has been completed. Figure 4 shows a photo-Fig. 5. Newly designed layout of the fRC as well as theinjection and extraction beam lines.

Fig. 4. Photograph of the completed pole as well as thevacuum chamber wall for the fRC.

286

graph of the completed pole as well as the vacuum
chamber wall. The layout of the fRC as well as theinjection and extraction beam lines has been changed;
the beam transport line from the fRC to the IRC isplanned to be set in experimental rooms E4, E3, E2
and E1. The newly designed layout is shown in Fig. 5.
The construction of the cooling water system for the
new facility was started in October 2003; it is scheduled
for completion by the spring of 2004.

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Magnetic field perturbations from the injection and the extraction
elements of the RIKEN SRC and their correction
J. Ohnishi, H. Okuno, A. Goto, and Y. Yano
The magnetic elements used for the beam injectionand extraction in the superconducting ring cyclotron(SRC) generate magnetic ﬁeld perturbations on theisochronous ﬁeld required for the beam acceleration.
These magnetic ﬁeld perturbations were calculated using the three-dimensional magnetic ﬁeld calculation
code “TOSCA” and their correction by the normalconducting trim coils was simulated.
Figure 1 shows a schematic of the SRC injectionand extraction elements and trajectory of the beam.1)
The injection system consists of one superconducting bending magnet (SBM),2) two normal-conducting
magnetic inﬂection channels (MIC1 and MIC2),3) and
one electrostatic inﬂection channel (EIC). The extraction system consists of one electrostatic deﬂection channel (EDC), three normal-conducting magnetic deﬂection channels (MDC1, MDC2, and MDC3),and one normal-conducting extraction bending magnet(EBM).4)
To estimate the magnetic ﬁeld perturbation, we
carried out three-dimensional magnetic ﬁeld calculations for the SRC with and without the injection andthe extraction elements. We show the results for
a 350 MeV/nucleon uranium beam in Fig. 2. The magnetic ﬁeld perturbations on the ﬁrst circulation orbit
by the SBM and the MIC2, and on the last one by the
EBM are illustrated in the ﬁgure. These three components are large compared with the perturbations fromthe other elements.
The magnetic ﬁeld in the valley region of the cyclotron is in the direction opposite to that of the hillregion and the ﬁeld strength is approximately −74 mT

Fig. 1. Schematic of the injection and the extraction elements of the SRC.

Fig. 2. Magnetic field perturbations on the first circulation orbit from the SBM and the MIC2 and on the last
one from the EBM. Abscissa indicates azimuthal angle
from the center of the sector magnet where the MIC2
is located.

and −58 mT on the ﬁrst and the last circulation orbit,
respectively, at the center of the valley region. The direction of the error ﬁelds is the same as that of the sector ﬁeld because iron yokes of the SBM and the EBM
absorb the magnetic ﬁeld in the valley region and reduce it. On the other hand, the error magnetic ﬁelds
from the MIC2 can be corrected by the compensationcoil, but they are not corrected perfectly because it isdiﬃcult to cancel the leakage ﬁeld from both ends.
Figure 3 shows the radial distributions of the magnetic perturbations by the SBM, the MIC2, and the
EBM averaged over the azimuthal direction. Theseerror ﬁelds need to be corrected by 22 pairs of normalconducting trim coils of the sector magnets5) so thatthe deviation from the isochronous ﬁeld may be at thelevel of 1 × 10−4 . Figure 4 shows the magnetic ﬁeld
distributions generated by the normal-conducting trim
coils. The current of each coil is 600 A. From theseFig. 3. Radial distributions of the azimuth average perturbation magnetic fields from the SBM, the MIC2, andthe EBM.

287

turbation ﬁelds. Figure 5 shows the residual magnetic
ﬁeld distribution after the ﬁeld correction by the trim
coils. The residual magnetic ﬁeld strength is found tobe smaller than 1 × 10−4 of the average one on the
beam orbit (1.3–1.4 T). Figure 6 shows the current
values of the trim coils. They are within the capacity of the power supplies whose nominal currents are
600 A, 800 A, and 1200 A. Although the magnetic ﬁeld
perturbations from the injection and the extraction elements vary with the type of accelerated ions, a similarcorrection can be carried out.
Fig. 4. Radial distributions of the azimuth average magnetic fields of 22 pairs of the normal-conducting trim
coils. The current of each coil is 600 A. The magnetic
fields were calculated assuming that the trim coils are
air-core.

ﬁeld distributions, the current set of the trim coils wasdetermined by the least-square ﬁtting so that the magnetic ﬁelds by the trim coils reduce markedly the perFig. 6. Currents of the main and the normal-conducting
trim coils required for the correction of the perturbation
fields from the SBM, the MIC2, and the EBM.

References

Fig. 5. Simulated residual magnetic field after the field correction by the normal-conducting trim coils.

288

1) S. Fujishima et al.: RIKEN Accel. Prog. Rep. 34, 341(2001).
2) H. Okuno et al.: IEEE Trans. Appl. Supercond. 12, 192(2002).
3) S. Fujishima et al.: IEEE Trans. Appl. Supercond. 12,
63 (2002).
4) S. Fujishima et al.: Proc. 13th Symp. on Accelerator
Science and Technology, Suita, 2001-10 (2001), p. 274.
5) A. Goto et al.: AIP Conf. Proc. 600, 319 (2001).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Cranes for RIBF
T. Fujinawa, T. Yamashita,∗1 N. Yamasaki,∗1 K. Kawamoto,∗2 M. Kase, and Y. Yano
In the RI Beam Factory project, each facility (accelerator, magnet and other devices.) installed is considerably heavy in its weight. For instance, the SRC isestimated to be more than 8000 tons and the Big-RIPS
radiation shield approaches 5000 tons. Each component of the facility will be brought into the factoryfrom the manufacturer by a 30-ton trailer. Up to eighttrailers are used per day. We have chosen and installed
eight cranes (Table 1), for carrying, constructing, andmaintenance. These cranes1) are arranged in the RI
beam factory as shown in Fig. 1.
The common features for all cranes are as follows.
1.

2.
3.
4.

5.

The inverter operation system adopted here, alleviates potential shock caused by starting andstopping, and signiﬁcantly reduces energy consumption by 50%.2)
Usage of hoist motor reduces the size and weightof the cranes.
Both wired and wireless operations are available.
A high-resistant basket-type induction motor,
which has a large starting torque and low striking current, has been adopted to endure constant inching operations. Those enabling it tostart quickly and maintain low exothermic heat.
Such features extend the lifetime of all equipment. The thermal relay protection is not necessary.
Since the electric power is supplied by a CGS3)
bus bar, every crane can be operated even incase of a blackout.

Fig. 1. Layout of all cranes in the RI beam factory.

The feature of each crane used is as follows.
SRC Crane A: A 60-ton crane is used based on function
requirements and cost eﬀectiveness. In order to minimize its size, the following amendments were made.
(1) To minimize the clearance between the crane andthe ceiling of the building, a single shaft for hook block
was applied. (2) To reduce the height, the diameter ofthe wheels was halved but the number of e wheels was

Table 1. Crane specification.
Crane NO.

Type
Rated Load (ton)Span (m)LiftOperation
Rated Speed
Main Hoist (m/min)
Aux.Hoist (m/min)Traverse (m/min)Travel (m/min)Travel RailElectric Power

Crane A

Crane B

Crane C

Crane D
Crane E Crane F Crane G
Crane H
CarryEloctrical
Eloctrical
CarrySRC
IRC
Big-RIPS In Entrance Room 1 Cryogenic Room 2 In Entrance§1 OTC§1 OTC§1 OTC§2 BG§3 TELPH §3 TELPH §3 TELPH §3 TELPH
69/5 t35/5 t40/5 t
40 t
2.8 t
10 t
7.5 t
2t
26.3
21
18.85
6.6
—
—
—
—
12.35/13.55 12.73/13.965 10.7/12.15
18
12.42
13.2
11.21
4.515
Wireless
Wireless
Wireless
Wireless
Wireless Wireless WirelessPendant
2.5
818
18
37 kg/m

2.5
8
18
18
37 kg/m

2.5
8
18
18
37 kg/m

2.5
10
—
—
18
—
18
25
37 kg/m—
AC 200 V 50 Hz 3 ph

6
—
—
15
—

7
—
—
15
—

10
—
—
25
—

§1 OTC: Overhead travelling crane§2 BG: Bridge crane§3 TELPH: Telpherage∗1∗2

JFE Mechanical Co. Ltd. (Formerly Kawatetsu MachineryCo., Ltd.,)
Mitsubishi Electric Hoist Co.

289

doubled. (3) By separating the hoist motor unit fromthe cross travel equipment, their size was reduced 15%.
SRC Crane B: This is used for IRC erection and maintenance.
Big-RIPS Crane C: The size reduction is similar to thatof SRC Crane A. By removing a part of the building
walls, “dead space” was reduced by 65 cm.
Portal Shape Crane D: The crane is placed at the entrance and the most of the accelerator equipment isbrought into the building by this crane.
Telpherage Crane E: This crane is used mainly fortransporting electrical panels from the existing building to the RIBF building.
Cryogenic Crane F: This is used to handle Cryogenics.

290

Electric Room Crane G: This is used to transport electric panels, which were brought in by Crane D, to theelectric rooms.
Carry-In Entrance Crane H: This is arranged due tothe fact that the elevator ﬂoor was 1.1 meter higher
than the entrance ﬂoor.
References
1) T. Nomura: OASIS 2003 SPRING (Kawatetsu Machinery Co., Ltd., Sougensya, Tokyo, 2003).
2) Mitsubishi Hoist Technical Report R-4 (2000).
3) T. Fujinawa et al.: RIKEN Accel. Prog. Rep. 36, 310(2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Current status of the control system development at
RIKEN RI-Beam Factory†
T. Tanabe, T. Masuoka, K. Yoshida, K. Kumagai, M. Kobayashi-Komiyama, T. Emoto, and M. Kase
The deployment of the Common Object Request
Broker Architecture (CORBA)-based control system
for RIKEN’s RI-Beam Factory Project1) has started.
Vendor independence, software sharing and interoperability are the main aims of the design. Abeans R22)
developed at Jozef Stefan Institute (JSI) of Slovenia
has been connected to our CORBA servers running on
VMEs via plug-ins. Oracle9i running on Linux is employed to store the data, operation loggings and device
conﬁgurations. XMLs are utilized to set the conﬁguration of each device from the DB to the equipment.
The power supply (PS) controls are ﬁrstly deployed aswell as RF monitor via Programmable Logic Controller(PLC).
The overall system architecture including some future extensions is shown in Fig. 1. The Java graphical user interface (GUI) programs work as a CORBA
client only except for the alarm call-back function.
Both server and client objects are in the application
server (AS). Those in the VME are mostly servers except for the one which gets the parameter data fromthe database. The relational database management
system (RDBMS) functions as the back end of the AS
and cannot be accessed directly from other objects.
GPIB wrapper and CORBA-EPICS server are still in
the prototype stage and they will be ﬁeld- tested in the
coming months. Table 1 shows the list of hardware andsoftware used in the system.
Motorola’s VME-CPU board (MVME2400) with
512MB RAM is chosen for the ﬁeld controller. The

Table 1. List of the used hardware and software (those inbold characters are commercial software).

Fig. 1. System architecture.
†

Condensed from the article in the Proc. 9th Int. Conf. on
Accelerator and Large Experimental Physics Control System (ICALEPCS ’03), Gyeongju, Korea, 2003-10 (to be published)291

VME64x crate (HS-SY013) has 15 slots and hotswappable redundant power supplies for easy maintenance. It also has an alarm function for errors, and
5V35A, +12V4A, −12V1A; 3.3V25A of DC output canbe used.
All the equipment-CORBA-objects are running inthe VME including a poller program. There is only
one type of program running in all the VME and thediﬀerences in terms of conﬁgurations and types of objects to be activated are determined from the DB data.
Since VisiBroker-RT 4.1c does not support “wstring”
type, Japanese characters cannot be handled in thesame way as the Latin alphabet. Therefore, the unicode escape sequence was used to send Japanese via
CORBA when necessary. The features of RT-CORBA
such as “thread pool” and “server-declared CORBA
priority” are employed to control the various task priorities. The PropertyResourceBundle class in Java isused to switch languages.
The NIO system comprises of the NIO-C masterboard in the VME crate and NIO-S slave boards which
are located in the PSs.3) They can be connected toeach other by serial communication of 2 Mbps eitherwith SI ﬁbre optical (F/O) cable in a star topology
using branch boards or RS485 balanced serial cable inseries. NIO-S has its CPU with a ﬁrmware running
so it can be operated independently from the master,even if communication with it is severed. This concept
has been carried over from the CAMAC-based I/O system that our existing facility utilizes. The ﬁrmware of
NIO-S can also be downloaded from the host computerin order to ensure easy maintenance and modiﬁcation.
Linux is used for the AS and the RDBMS. For the
AS, Redhat Linux Advance Server 2.1 was chosen for
its support availability. Oracle 9i for Linux is installedin Miracle Linux which is produced by a subsidiary ofOracle, Inc. and integrated support for both DB andOS are available. PS CORBA objects on any VME canbe accessed and controlled by a CORBA client whichin our case is the Power Supply (PS) Panel program
made by JSI and modiﬁed by Cosylab. There are two
types of screens; one for monitoring, and the other for
setting-up and operating multiple PSs simultaneously.
Individual PSPanels can be opened only through either of the above-mentioned screens. Each VME has
many PS objects and it is ineﬃcient for individual objects to ask the interoperable naming service (INS) for
the interoperable object reference (IOR) every time the
PSPanel is activated. The top screens for the PS control collect all the IORs at the beginning so that eachindividual PSPanel can immediately know where theobject is. The setup information for each PS is sent
to the PS object in terms of XML generated from thedata from the RDBMS through JDBC. The UML Sequence diagram of PS Summary operation is given in

292

Fig. 2. Sequence diagram for PS summary operation.

Fig. 2.
The program for the polling runs in the VME andit sends the data to the logging object in the AS. Thisobject writes the contents in both the shared memory
and the DB. The Alarm Handler (AH) object will readthe contents of the shared memory and report errors
when the preset conditions are met. The RF monitor screen is also made of Abeans. The GUI programcommunicates with the PLC wrapper object4) which
read/writes the data in the memory area of the PLC(OMRON SYSMAC CVM1/CV) through UDP withFINS commands that are provided by the manufacturer.
In summary, the world’s ﬁrst RT-CORBA-based
accelerator control system has been implemented at
RIKEN. The fact that LHC accelerator controls at
CERN have decided to use CORBA in their middleware guarantees more extensive use of it in the accelerator community in the future.
References
1) http://ribfweb1.riken.go.jp/
2) http://www.cosylab.com/
3) http://www.ndssf.co.jp/
4) http://accelconf.web.cern.ch/AccelConf/ica01/papers/
THAT003.pdf

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Status of the BigRIPS separator project
T. Kubo, K. Kusaka, Y. Mizoi, A. Yoshida, and K. Yoshida
The in-ﬂight radioactive isotope (RI) beam separator BigRIPS1) is being built to produce RI beams in
the RI-beam factory (RIBF) project.2) The ﬁrst RIbeam production using the BigRIPS is scheduled inlate 2006. Nuclear physics experiments using RI beams
will begin in early 2007. The use of in-ﬂight ﬁssion of
uranium beams at 350 MeV/nucleon is planned for theﬁrst RI-beam production.
Figure 1 shows a schematic of the BigRIPS separator, which is followed by RI-beam delivery lines andexperimental setups. The construction of two BigRIPS separators, as shown in the ﬁgure, has beenplanned. This makes it possible to perform two different RI-beam experiments simultaneously by timesharing of primary beams. One of the separators is
a large-acceptance separator, indicated as BigRIPS-I
in the ﬁgure, for which large-aperture superconducting quadrupole triplets are employed to achieve eﬃcient collection of ﬁssion fragments. BigRIPS-I, including its RI-beam delivery lines, was funded, thus,
some components of the magnet system are alreadybeing fabricated. The other is a medium-acceptanceseparator, indicated as BigRIPS-II, whose quadrupole
magnets are room-temperature magnets. The basic design of BigRIPS-II has already been ﬁnished, including
its RI-beam delivery lines, however, the funding is get
unavailable. In this report we describe the fabrication
status of the large-acceptance superconducting sepa-

rator BigRIPS-I. The design details of the BigRIPS
separator are given in Ref. 1.
The large-acceptance BigRIPS forms a two-stage
separator. The ﬁrst stage separates and produces
RI beams, while the second stage is used to tag isotope species of RI beams in an event-by-event mode.
It consists of fourteen superconducting quadrupole
triplets (STQ)3) and six room-temperature bending
dipole magnets. The STQs and the dipole magnets
are being fabricated by Toshiba Corporation and will
be complete by early 2004. The ﬁve STQs in the ﬁrst
stage are cooled by liquid helium supplied by a largescale, integrated cryogenic system through a transfer
line,4) while the rest of the STQs are cooled by a small
cooling system which is mounted on each cryostat of
the quadrupole triplets.5) The large cryogenic system
is being fabricated by Nippon Sanso Corporation andsome of its components, such as compressors and buﬀer
tanks, have already been installed in the RIBF building. The installation of the magnet system of the ﬁrst
stage, the ﬁve STQs including the cryogenic systemand the two dipoles, will be complete by the end of
March in 2004. The rest of the STQs and dipoles will
be installed later in 2004 to 2005. A license which is required for building a large cryogenic system was issued
in October 2003 by the Saitama municipal government.
Figure 2 shows a photograph of the STQ with a small
cooling system, which is being fabricated in a Toshiba

Fig. 1. Schematic of the BigRIPS separator. The BigRIPS is followed by RI-beam delivery lines andexperimental setups.

293

The design of focal plane chambers, vacuum system,
RI-beam diagnosis devices installed in the chambers,
and beam-line detectors including the data-acquisition
system are under way. The neutron-radiation shieldingis also being designed.11) The RI-beam delivery linesthat follow the BigRIPS have already been designed.
The same superferric STQs equipped with the small
cooling system and the same dipoles will be used forthe delivery lines. The design of the BigRIPS control
system is also under way. These devices will be fabricated and installed between 2004 and 2006.
References
Fig. 2. STQs being fabricated in a Toshiba factory.

factory.
The STQs are of superferric type3) except for theﬁrst one which is placed right after the production target in the ﬁrst stage. This ﬁrst STQ is of air-core
type, aiming at reducing neutron-radiation heat loads
to the cryogenic system. Its design is also found in
this progress report.6) A special current-lead system
has been designed for the ﬁve STQs in the ﬁrst stage,aiming at stable cooling of the current leads. Its design
and testing are also found in this progress report.7)
The design study and development of a high-power
beam dump and a high-power rotating-disk production target are under way. They are crucial since theexpected beam power in the RIBF is as high as approximately 100 kW. A high-power beam dump in which
swirl tubes are employed has been designed and its
prototype for testing has been built. The developmentof the beam dump8,9) and production target10) is also
found in this progress report.

2941) T. Kubo: Nucl. Instrum. Methods Phys. Res. B 204,
97 (2003).
2) Y. Yano et al.: AIP Conf. Proc. 600, 161 (2001).
3) T. Hirumachi et al.: IEEE Trans. Appl. Supercond.
10, 236 (2000); H. Kouzu et al.: RIKEN Accel. Prog.
Rep. 34, 350 (2001).
4) T. Kubo at al.: RIKEN Accel. Prog. Rep. 36, 316(2003).
5) K. Kusaka et al.: RIKEN Accel. Prog. Rep. 36, 314(2003).
6) K. Kusaka et al.: RIKEN Accel. Prog. Rep. 37, 297(2004).
7) N. Kakutani et al.: RIKEN Accel. Prog. Rep. 37, 299(2004).
8) Y. Mizoi at al.: RIKEN Accel. Prog. Rep. 37, 303(2004).
9) Y. Mizoi at al.: RIKEN Accel. Prog. Rep. 37, 305(2004).
10) A. Yoshida et al.: Nucl. Instrum. Methods Phys. Res.
A 521, 65 (2004); A. Yoshida et al.: RIKEN Accel.
Prog. Rep. 37, 295 (2004).
11) K. Yoshida et al.: RIKEN Accel. Prog. Rep. 37, 301(2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Design study of the high-power production target
for the Big-RIPS separator
A. Yoshida, Y. Mizoi, Y. Takahashi, T. Kubo, I. Tanihata, K. Yoshida, and K. Kusaka
A water-cooled rotating target system for the projectile fragment separator (Big-RIPS) in the RI Beam
Factory (RIBF) has been developed. A prototype wasconstructed, and a test experiment using an 40 Ar9+
beam with an energy of 24 MeV/nucleon and an intensity of 1.9 particle µA was performed.1) Simulation with the ANSYS code based on the ﬁnite element
method could represent the data.2) A practical target
system has been designed using the same simulationcode.
The severest operating conditions for the production target in future Big-RIPS is a 238 U primary beamwith an energy of 350 MeV/nucleon and an intensityof 1 particle µA incoming onto a beryllium (Be) target
with a 1-g/cm2 5.4 mm thickness (thickness/range =0.36). The assumed beam-spot size of φ 1 mm in
FWHM and an estimated total heat loss of 22 kW deposit quite a high energy with a density of 28 kW/mm2
on the target surface and of 5.1 kW/mm3 in a target volume. Under these conditions, adjustable parameters for the target design are disk size, rotation
speed, and beam-spot position on the disk. A Be
disk of 260 mm diameter and 4.4 mm thickness, andwith a rotating speed of 500 rpm and a beam-spot position 10 mm from the edge of the water-cooled aluminum (Al) disk was designed as an expected parameter, because we have already constructed a prototype
target disk of similar size. The beam-spot temperature dependence on these three parameters was investigated. A transversely Gaussian-shaped beam distribution with a size of φ 1 mm in FWHM was assumed
and an energy loss function of the 238 U beam in Be material was applied. Two types of boundary condition
between the water-cooled Al disk and the cooling water
were considered. One is an ideal case in which the temperature at the boundary was ﬁxed at 25◦ C. The otheris a realistic case in which the heat transfer coeﬃcientat the boundary was 30 kW/(m2 · K). From the result,
the temperature distributions for both cases were almost the same. Thermal radiation from the surface of
the Be disk was considered and a constant emissivityof 0.57 was used. Nonlinear time-dependent analysis
was carried out taking the temperature dependence ofheat conductivity and speciﬁc heat of the materials
used into account. The typical heat conductivities andspeciﬁc heats of the Be disk are 180 W/(m · K) and1.98 J/(g · K) at room temperature, and 86 W/(m · K)
and 2.89 J/(g · K) at 700◦ C.
Beam-spot temperature as a function of rotation
speed is plotted in Fig. 1. When the rotation speed isfaster than 300–500 rpm, the beam-spot temperature

Fig. 1. Simulation result of beam-spot temperature asa function of disk rotation speed.

is suﬃciently low compared to the Be melting temperature of 1287◦ C. Rotation speed does not considerably decrease beam-spot temperature at more than
500 rpm. The disk-size dependence of temperature isplotted in Fig. 2. The disk diameter being smaller thanthe expected parameter (260 mm in diameter) is not realistic because beam-spot temperature approaches the
Be melting point. The temperature distribution in theradial direction including the beam spot is plotted inFig. 3. As the beam-spot approaches the water-cooled
Al disk, the temperature distribution of the Be disk decreases and we can get suﬃcient margin for both themelting temperatures of Be and Al.
From the result described above, the expected parameter of the rotating Be disk is acceptable even forthe severest operating conditions. This applies to otheroperating conditions for primary beams lighter thanFig. 2. Simulation result of beam-spot temperature asa function of disk diameter.

295

Fig. 3. Simulation result of temperature distribution in the radial direction of the target disk withchanging the beam-spot position in the radial direction (up). Cross-sectional temperature distributionof the target disk near the beam spot (bottom) when the beam spot is 10 mm from the edge of thetarget disk.

the U beam, because such conditions are much lesssevere than the case discussed.
References
1) A. Yoshida et al.: RIKEN Accel. Prog. Rep. 34, 188296(2001).
2) A. Yoshida et al.: RIKEN Accel. Prog. Rep. 35, 152(2002).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Design of an air-core type superconducting quadrupole for the
BigRIPS separator
K. Kusaka, T. Kubo, T. Tominaka, Y. Mizoi, K. Yoshida, A. Yoshida,
N. Kakutani,∗ T. Tsuchihashi,∗ and K. Sato∗
Superconducting quadrupole magnets are to be used
for the BigRIPS separator1) in the RI-beam factory
project.2) Two types of superconducting magnets areplanned for the BigRIPS. One is an iron-dominated(superferric) type in which quadrupole ﬁeld distribution is mainly generated by hyperbolic cold iron poles.
Superconducting coils are rigidly supported by a coldiron yoke.3) Since whole magnets are in the He vessel,
its cryostat has simple structure and is characterized
by small heat load, such that small cryocoolers are sufﬁcient to keep coils superconducting.4)
The other is an air-core type in which only coils generate magnetic ﬁeld. Since no cold iron is installedin the He vessel, its cold mass weight is much lower
than that of the superferric type. With the smaller
cold mass, the air-core magnets are adopted for thequadrupole triplet right after the production target,
since it will be exposed to high neutron radiation fromthe target. The neutron radiation gives rise to significant additional heat load to the cold mass at 4.5 K
in the He vessel. The smaller cold mass reduces theheat load to the cryogenic system. Furthermore, thequadrupoles right after the production target musthave high ﬁeld gradients in order to collect diverging
RI beams eﬃciently. The air-core quadrupole is suitable for achieving high ﬁeld gradients with good ﬁeld
quality without suﬀering magnetic saturation of ironpoles. We here report the design of the air-core superconducting quadrupole triplet for the BigRIPS.
Figure 1 shows a schematic view of the superconducting coils forming a quadrupole triplet. The eﬀective lengths and warm bore radii of three quadrupoles,
P1, P2, and P3, are 500 mm, 800 mm, and 500 mm,
and 90 mm, 120 mm, and 120 mm, respectively. The
maximum ﬁeld gradients of P1, P2, and P3 coils are

24 T/m, 20 T/m, and 20 T/m, respectively. The main
parameters of quadrupoles are listed in Table 1.
As shown in Fig. 1, our coils have a racetrack shapeand diﬀer from a “cos 2θ” type in which multistrand
Rutherford cables are wound and compressed into a
trapezoidal shape to form ideal current blocks. Since
the requirement of uniformity of the ﬁeld gradient isrelatively moderate, we adopt a simple racetrack shapefor easier coil winding. Sizes and positions of coils are
optimized to maintain a single square racetrack coilper pole. Integrated 12-pole components scaled by thequadrupole component are estimated to be −4, −2,
and −2.8 × 10−3 for P1, P2, and P3 coils, respectively.
We use a NbTi superconducting wire with apolyester-imide (PEI) insulator. PEI is chosen for the
insulation material, because it is less sensitive to radiation than polyvinyl formal enamel (PVF) which is
widely used for insulating superconducting wire. Since
the nominal currents and resulting stored energies arehigh compared with those of the superferric type magnet, we use a rectangular wire instead of round ones.
Table 2 summarizes the speciﬁcations of the superconducting wire.
Quench protection analysis is performed for the P2
coil whose stored energy is the highest. We have introduced a quench protection external resistor Rp connected in parallel in the excitation circuit. We assume
that only one of the P2 coil quenches under the operating current of 625 A and magnetic ﬁeld of 6.9 T. The
current decays in ∼5 s and the maximum voltage andthe temperature of the coil reach 897 (1361) V and 100(117) K in the case of the external register Rp = 1.0(0.01) Ω.
The winding of our ﬂat racetrack coils are es-

Table 1. Main parameters of P1, P2 and P3 quadrupoles.

Fig. 1. Schematic of racetrack coils forming a quadrupole
triplet.
∗Toshiba Corporation

P1
P2
P3
Eﬀective magnetic length [m]∼0.5 ∼0.8 ∼0.5
Warm clear bore radius [mm]90120 120
Max. ﬁeld gradient [T/m]24
20
20
Nominal current per pole [kA]552 825 825
Number of turns
750 1320 1320
Nominal current [A]
735 625 625
2Nominal current density [A/mm ] 188 159 159
Straight length of coil [mm]420 700 420
Max. ﬁeld at coil [T]
6.0
6.9
7.0
Total length of coil [mm]568 880 600
Inductance [H]1.33 6.47 4.35
Stored energy [MJ]
0.36 1.26 0.85

297

Table 2. Main parameters of superconducting wire.
Conductor

NbTi

Bare conductor size [mm]2.28 × 1.38

Insulated size [mm]2.36 × 1.46

Insulator

PEI (Polyester-imide)

Cu/super ratio

1.33

Number of ﬁlaments

54

Filament diameter [µm]1753300 at 5 T
2700 at 6 T
2100 at 7 T
1450 at 8 T

Ic [A]

sentially the same as that used for the superferricquadrupole triplets of the BigRIPS separator.1,2) Eachcoil is wound orderly on a mandrel by the wet winding method developed by Toshiba. Epoxy resin withﬁllers, which improves thermal conductivity and makes
the thermal contraction rate similar to that of wire, isapplied to coils by layer by layer.
Since the coils experience high magnetic ﬁeld of|B| = 6–7 T, electromagnetic force acting on coil ends
becomes much stronger than that of superferric magnets. Simulations based on the ﬁnite element methodsuggest that the entire outer circumference of the coilmust be supported in order for the maximum shear
stress not to exceed 10 MPa. If only the straight sections of the coil are supported, as in the case of superferric magnets, the maximum shear stress is estimatedto be 22.7 MPa.a) We then introduced the stainlesssteel nonmagnetic coil case to support coils.
Figure 2 shows a schematic view of the P2 coil case.
The coils are supported by walls of the coil case withwedge sims and thin copper liners. The round coil ends
are supported by the round stainless-steel spacers withwedge sims and liners made of glass and epoxy resin.

FRP plates are attached to the coils for insulation, andthe gap between coils and supporting materials is ﬁlled
by the epoxy resin used in coil winding. The precisionof the coil position is better than 0.5 mm. It should be
noted that no preload to the coils is necessary, since
the coils and the coil case contract almost at the samerate when they are cooled to 4.5 K.
Figure 3 shows a schematic cross sectional view of
the cryostat. P1, P2, and P3 coils in their coil cases areconnected rigidly to each other and form a quadrupole
triplet. The He vessel, tightly connected to coil cases,
is designed to be oﬀ-centered to use LHe eﬃciently.
The He vessel, surrounded by the 80 K shield madeof aluminum, is suspended by supporting rods madeof CFRP or GFRP, and its position can be adjusted
from outside the vacuum vessel. The end ﬂanges ofthe vacuum vessel made of SS400 steel, play the roleof a magnetic shield, so that stray ﬁeld at the target position is less than 20 gauss. In the current portof the cryostat, newly designed gas-He cooled current
leads are installed. Their design and R&D results arereported somewhere.5)

Fig. 3. Schematic view of cryostat.

References

Fig. 2. Schematic view of P2 coil.

a)

298

The maximum shear stress of the superferric magnet is
13 Mpa.

1) T. Kubo: Nucl. Instrum. Methods Phys. Res. B 204,
97 (2003).
2) Y. Yano et al.: AIP Conf. Proc. 600, 161 (2001).
3) T. Hirumachi et al.: IEEE Trans. Appl. Supercond. 10,
238 (2000).
4) K. Kusaka et al.: RIKEN Accel. Prog. Rep. 36, 312(2003).
5) N. Kakutani et al.: RIKEN Accel. Prog. Rep. 37, 299(2004).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Gas-cooled current lead with multiple electrodes
for BigRIPS superconducting quadrupoles
N. Kakutani,∗ K. Kusaka, Y. Mizoi, A. Yoshida, K. Yoshida, T. Kubo, K. Ohsemochi,∗T. Yazawa,∗ S. Monma,∗ T. Kuriyama,∗ and T. Tsuchihashi∗Superconducting (SC) magnets for the BigRIPS
in the RI beam factory project are used forming aquadrupole triplet with/without a superimposed sextupole coil. The three quadrupoles with/without sextupoles are installed in a single cryostat. While thecoils are cooled by liquid helium, current leads arecooled by helium gas vapor. The electric currents are,in general, diﬀerent among the coils in operation. This
type of SC magnet, namely, a cryostat which contains
more than two magnets, requires many gas channels
for each current lead and complicated cooling gas control to prevent gas ﬂow imbalance among the current
leads. Furthermore, many gas channels require a larger
current port and larger space for piping work.
We here report a new current lead for the BigRIPS
SC magnets developed by Toshiba. It is a current leadwith multiple electrodes in one cooling gas channel,
with which no complicated multi-channel gas control isrequired. It also makes removal and installation workof magnets easier because the number of gas pipes isreduced. We shall report results of our R&D studies
performed in Toshiba.
The newly developed current lead with multiple electrodes is shown in Fig. 1. The length of the lead, except
the current input ﬂange, is 816 mm and the diameterof the cylinder is 70 mm.
This current lead consists of four high-current electrodes for 800 A and a low-current electrode for 70 A
positioned circularly in a cylinder. High-current electrodes correspond to the leads for the quadrupole coils
and the low-current electrode corresponds to the leadfor the sextupole coil. Each electrode is made of a bundle of phosphorous-deoxidized copper tubes. This current lead with multiple electrodes has the feature thatcooling gas passes through spirally with disks vertically arranged across the electrodes. Therefore, coolinggas passes through all electrodes without concentrating around low-temperature electrodes, so that all theelectrodes are well cooled even if the electric currents
are diﬀerent among electrodes.
The electric current excitation test of the lead was
carried out in Toshiba. The maximum current for thetest is 800 A for high-current electrodes. This current
is suﬃcient for the BigRIPS SC magnets, whose maximum current is evaluated to be 733 A. The electric
current excitation test of this lead was carried out by
connecting the ends of the electrode in liquid helium
bath with short-circuit bars. The schematic of the experimental setup is shown in Fig. 2.
The temperature distribution on the electrode wasconverted from the voltages measured by eight taps puton the electrode. Helium gas temperature is measured
by thermo-couples and temperature sensors mounted
on the electrode. Heat load was calculated from evaporated helium vapor mass ﬂow. We measured the temperature and voltage in two kinds of excitation circuits.
One is the “two-pole excitation” in which only two of
the high-current electrodes are short-circuited and nocurrent ﬂows in the rest. The other is “four-pole excitation” in which the current ﬂows in all of the highcurrent electrodes. We show, in Fig. 3, an exampleof the temperature distribution of the electrode withthe excitation current of 800 A. Shown also are elec-

Fig. 1. Overview of gas cooled current lead with multiple
electrodes.
∗

Toshiba Corporation

Fig. 2. Schematic of experiment.

299

Fig. 4. Change of the heat leak by current.
Fig. 3. Temperature change of the direction for current
lead length (Current: 800 A).

trode and helium gas temperatures as functions of distance from the low-temperature side of the electrodes.
A small diﬀerence between electrode and helium gas
temperature is observed in both four-pole and two-pole
excitations. In Fig. 4, heat load is shown as a functionof current. The heat load for the four electrodes with acurrent of 800 A is evaluated to be 4.4 W. This value islower than the twice of the ideal value, 2×3.3 = 6.6 W,
which is our design criterion. Heat load per electric
current is then 1.3 mW/A and heat transfer eﬃciency
between helium gas and current lead is evaluated to be300

0.8.1)The gas-cooled current lead with multiple electrodes
developed in Toshiba has been successfully tested. The
multiple electrodes are eﬃciently cooled by helium vapor with a single gas channel. This newly developed
current lead is going to be used in the SC quadrupole
triplets in the BigRIPS. Five SC quadrupole triplets
including air-core-type quadrupole triplet are now being fabricated in Toshiba.
References
1) M. N. Wilson: Superconducting Magnets (Clarendon
Press, Oxford, 1983).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Design of radiation shielding for the BigRIPS separator
K. Yoshida, T. Kubo, K. Kusaka, Y. Mizoi, A. Yoshida, E. Ideguchi,∗1 and H. Kouzu∗2
Radiation shielding is one of the important issues
in the design of a radioactive beam separator sincehuge radiation is expected to arise from the production target and the beam dump of the separator. The
conceptual design of the shield has been made and was

published as a report.1) In the design, the BigRIPS separator will be placed in the big room of the east sideof the underground of the accelerator building. The
size of the room is 67.3 m long, 19.2 m wide and 14.0 m
high. In the upper half of the separator, where strong

Fig. 1. Cross-sectional view of the shield around the ﬁrst triplet Q-magnet of the BigRIPS separator.

Fig. 2. Arrangement of shield blocks in the BigRIPS room.
∗1∗2

Center for Nuclear Study, University of Tokyo
Toshiba Corporation301

radiation is expected to arise, the ﬁxed concrete wallswith a height of 3.5 m are prepared on both sides of theseparator. The concrete blocks with a maximum 5.5 m
thickness covers the top of the separator. Instead of
the 5.5 m thick concrete, the possibility of using ironblocks of 1 m thickness together with 3 m thick concrete blocks is suggested to save the necessary space.
The advanced design of the shield has been started
based on the conceptual design. The discussion withthe manufacturers shows that it is cost eﬀective if
the sizes of the blocks fulﬁll the following conditions:(1) Maximum size of the block is 7 m×2.5 m×2.0 m.
(2) Weight of the block should not exceed 30 tons.
(3) Width of the block is a minimum of 1 m if theblock is supported only at both ends.
In the original design, the typical block size was
5.5 m×2.1 m×1.5 m and, hence, the size was reduced to302

match the above condition. The protection of incidental equipments of the separator, such as the transfer
tube of liquid He and their valves, is also considered in
the design.
Figure 1 shows the cross-sectional view of the shields
at the target area. The top of the target is covered withthree layers of concrete blocks with a size of 6 m×2 m×
1 m together with four layers of iron blocks with a sizeof 6 m × 2 m × 0.25 m. The shield blocks with elaborate
shapes are placed around the magnet of the separator
and protect the transfer tubes and the valves. The
total arrangement of the blocks is shown in Fig. 2.
The further optimization of the design as well as theconstruction cost is now under way.
References
1) Radiation Safety of RI Beam Factory, RIBF ProjectOﬃce, RIKEN, Wako, (2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Conceptional design of the high-power beam dumps for BigRIPS
Y. Mizoi, T. Kubo, K. Kusaka, K. Yoshida, A. Yoshida, and T. Okuyama∗
Beam dumps for BigRIPS will be installed inside thevacuum chamber of the ﬁrst dipole magnet (D1), andbetween D1 and the second superconducting triplet
quadrupole magnet (STQ2). Figure 1 shows theschematic top view of these beam dumps and BigRIPS
magnets, and the cross-sectional view of the beam
dump inside the vacuum chamber.
Inside the vacuum chamber, vertically-tilted swirlor screw-tube beam dumps1) are set at both ends inthe horizontal plane in the vacuum chamber. Although
the available space for the beam dump is limited, thetilted angle can be chosen to magnify the projectedbeam spot area on the beam dump so that the heat-ﬂux
density is suﬃciently diluted for cooling. The promising tilted angle is approximately 9.8 degrees.
The beam dump between D1 and STQ2 is shownin Fig. 2. Its shape from the top view is that of aparallelogram with a corner angle of Φ. The opening
angle of the cross section is 2Θ. However the available
space for this beam dump is limited, we can obtain the
optimum shape to dilute the beam heat-ﬂux density
suﬃciently by contriving its geometrical shape. The
dilution factor by projection, F , is expressed as
F =

1
1
×
.
sin Θ sin Φ(1)Assuming that the available space between D1 andSTQ2 is L and the beam spot diameter is 2R, F isFig. 2. Beam dump between D1 and STQ2. Its shape isuseful for diluting the heat density not only horizontally
but also horizontally.

expressed as



2R 2
R2 + L − tan
1
Φ
×
.
F =
R
sin Φ

(2)

Fig. 1. Schematic top view of the beam dumps and BigRIPS magnets, and cross-sectional view of thebeam dump inside the vacuum chamber. The beam dumps between D1 and STQ2 move horizontallyaccording to Bρ. The available space between D1 and STQ2 is very limited.
∗Toshiba Corporation

303

Here, the maximum value of F can be derived fromthe diﬀerential equation of ∂F/∂Φ = 0 under the condition of the limited values of L and R. We choose thepreliminary values of L = 30 cm and R = 2 cm, thenΦ = 15 degrees is obtained.
A promising material for the BigRIPS beam dump
is CuCrZr which is also considered a candidate heatsink material for ITER which can be used under highheat-ﬂux and high-neutron-ﬂux conditions. Although

304

CuCrZr has suﬃcient heat-transfer coeﬃcient and radiation hardness, we need to study the manufacturing
process in relation to its mechanical hardness. We arecontinuing to research and develop high-power beam
dumps.
References
1) Y. Mizoi et al.: RIKEN Accel. Prog. Rep. 36, 318(2003).

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Prototype of the high-power beam dump for BigRIPS
Y. Mizoi, T. Kubo, K. Kusaka, K. Yoshida, A. Yoshida, and T. Okuyama∗
We constructed a prototype beam-dump system inorder to evaluate its cooling power for high-density
heat ﬂux. The prototype beam-dump system schematically shown in Fig. 1 consists of a prototype beamdump, a vacuum chamber, a high-pressure water pump(∼10 atm), and measurement devices which are for water pressure and water temperature both inlet and outlet, and water ﬂow at the outlet.
We are planning experiments using two heating
methods for evaluating the ability of the prototype
beam-dump system. One method is the laser-beamirradiation heating method and the other is the heavyion-beam-irradiation heating method. Here, the prototype beam dump is the sample.
These methods are complementary to each other. In
the former method, it is easy to control and monitor
the irradiation area on the sample, although the absorbed power on it must be estimated indirectly due
to its reﬂection. In the latter method, it is easy toestimate the deposited power on the sample, although
the irradiation area on it is ambiguous.
A YAG or a CO2 DC laser whose power is at leasta few kW will be irradiated on the sample. Before theexperiment, we will measure the surface reﬂectance ofthe sample with a low-power laser beam in order to estimate the absorbed power. It is noted that the experiment with the laser beam irradiation can be performed
in air without a vacuum chamber.
Heavy-ion beams, for example, 40 Ar with a powerof approximately 2 kW (the energy is 24 MeV/nucleon
and the intensity is 2 pµA) will be irradiated on thesample installed in the vacuum chamber.
In both experiments, the surface temperature of thesample will be monitored using an IR camera. In addition, thermocouples will be set near the irradiated area
for the reference. The surface temperature of the sample will be measured as functions of heat-ﬂux density,
water temperature, water ﬂow, and water pressure.
We will derive the cooling ability as a parameter ofthe heat-transfer coeﬃcient of the sample from these
data. Experimental results will be compared with thesimulations1) and the feasibility will be demonstrated.
References
1) Y. Mizoi et al.: RIKEN Accel. Prog. Rep. 36, 318(2003).

Fig. 1. Schematic diagram of the prototype beam-dump system. P: water pump, P.I.: pressure indicator,
T.I.: temperature indicator, F.I.: flow indicator.

∗

Toshiba Corporation

305

Back to Contents
RIKEN Accel. Prog. Rep. 37 (2004)

Rf system with HOM damped cavity using SiC microwave
absorbers for electron storage ring
T. Koseki and M. Izawa∗An intense beam current is one of the essential
characteristics for modern electron storage rings, suchas high-luminosity colliders and high-brilliance synchrotron radiation sources. Evaluation and suppression of collective beam instabilities are very important
issues in the storage rings. In particular, the solving the coupled-bunch instability due to higher ordermodes (HOMs) in rf cavity is a key task for achieving a high beam current limit. We have developed a
500 MHz rf cavity with a simple damped structure of
HOMs.1,2) The cavity has a large diameter beam duct
(140 mm) made of a silicon-carbide (SiC) microwave
absorber. The HOMs are guided out of the cavity anddissipated by the absorber. The accelerating mode is
not aﬀected by the absorber since the frequency is sufﬁciently below the cutoﬀ of the 140 mmf duct. Figure 1 shows a schematic view of the damped cavity.
The shunt impedance and the Q value for the accelerating mode are 7.7 MΩ and 44000, respectively. The
available wall loss is 150 kW at maximum.
The damped cavities have been installed in the Photon Factory storage ring in KEK and pushed up thecurrent limit of the ring to 800 mA, whereas the record
current achieved with previously used cavities was approximately 500 mA.3) The damped cavity has also
been installed and operated well in the New SUBARU
ring, a 1.5 GeV synchrotron light source at the SPring8 site. Recently, it was decided to adopt the cavity for
the SAGA light source, a 1.4 GeV storage ring underconstruction in Tosu city, Saga prefecture.
In the damped cavity, HOMs with frequency lower
than the cutoﬀ frequency of the beam-duct cannot
propagate in the beam duct. Some of the HOMs remain in the cavity with high impedance. For the reduction of impedances of the trapped modes, we havedeveloped a simple HOM coupler4) as shown in Fig. 2.

Fig. 1. Schematic view of the damped cavity.
∗

306

High Energy Accelerator Research Organization (KEK)

Fig. 2. HOM coupler.

It has a rod-shaped coupling antenna with a coaxial
waveguide. The SiC piece attached to the end of thecoaxial waveguide is made of the same material as theabsorber at the SiC beam duct and absorbs the extracted HOM power. The copper block mounted on
the ICF ﬂange is used for detuning frequencies of a
few trapped modes which are unable to couple withthe rod antenna. In the center part of the cavity, there
are two free ports at the side and bottom positions.
The HOM couplers are attached to these free ports.
The damped cavity with the HOM coupler will beapplied to the future Japanese high-brilliance synchrotron light source in the vacuum ultraviolet andsoft X-ray region.5) The light source, called the Super
SOR storage ring, is being designed by the nationwide
collaboration of scientists and engineers from KEK,
SPring-8, RIKEN, JAERI, UVSOR and universities inJapan. The circumference of the Super SOR ring is
280 m, the nominal emittance is 8 nm·rad and the required beam current is 500 mA at maximum. The ringhas two 17-m long straight sections and twelve 6.2-mstraight sections for intensive use of various kinds ofinsertion devices.
The rf system must provide suﬃcient accelerating
voltage to compensate for the electron energy loss due
to synchrotron radiation and to achieve a long beam
lifetime. For the Super SOR ring, synchrotron radiation losses at the dipole magnets and the insertion
devices are more than 100 kW with stored current of
500 mA. To replace the energy and to provide for atypical momentum acceptance of 3%, the peak accelerating voltage of 1.4 MV is required. Figure 3 shows
calculated current dependence of rf power required forthe accelerating voltage of 1.4 MV with two and threerf systems. In this calculation, the coupling coeﬃcient
between input coupler and the cavity is set to 1.7. Although stable operation with two rf systems is possi-

(a)

(b)

Fig. 3. Current dependence of rf power for (a) two rf systemand (b) three rf system.

ble, unexpected trouble on one of the components may
cause a long shutdown of the ring. Therefore, three rf
systems operated under a moderate condition with alarge safety margin are preferable.
Figure 4 shows the calculated longitudinal andtransverse HOM impedances of the cavity. The critical impedances calculated by the Wang formalism6) for
typical 1.8 GeV operation modes of the Super SOR ringare also indicated in the ﬁgure. The critical impedance
denotes the impedance above which a coupled-bunch
instability may occur at 500 mA. The HOMs with frequency higher than the cutoﬀ frequency of the duct
(1.64 GHz for TM01 and 1.26 GHz for TE11) are dissipated by the SiC duct and their impedances are reduced to the values below the critical impedances. Fortrapped modes, the impedances are damped by the
HOM couplers. As shown in this ﬁgure, there are a

few surviving modes which cannot couple with the rod
antenna of HOM coupler. The harmful ones among thesurviving trapped modes are the longitudinal TM012like mode (1312 MHz) and the transverse TM110-likemode (790 MHz). The TM110 mode, however, can be
detuned easily so as not to induce the instabilities bychoosing an approproate length of the copper block of
the HOM coupler. On the other hand, for the TM012
mode, the frequency shift by the copper block is not
so large, and the detuning method is less eﬀective. If
a strong instability due to the TM012 mode occurs at
the ring, an other method such as the bunch-by-bunch
feedback method should be applied to suppress it.
Figure 5 shows a schematic layout of the rf stationin the Super SOR ring. Three cavities are installed
in one 6.2-m straight section. Each cavity is driven
by one 200 kW klystron operating at 500.1 MHz. The
power transmission system is composed of commercially available components of the WR1500 aluminum
waveguide, a 100 kW dummy load and a circulator
with 180 kW power capability.

Fig. 5. Schematic layout of the rf station.

References

(a)

(b)

Fig. 4. Impedance of the damped cavity for (a) longitudinaland (b) transverse modes.

1) T. Koseki, M. Izawa, and Y. Kamiya: Rev. Sci. Instrum.
66, 1926 (1995).
2) T. Koseki: Proc. Shanghai Symp. on IntermediateEnergy Light Source, Shanghai, China, 2001-9,(Shanghai National Synchrotron Radiation Center(SSRC), 2001), p. 156.
3) M. Izawa et al.: J. Synchrotron Radiat. 5, 369 (1998).
4) T. Koseki et al.: Nucl. Instrum. Methods Phys. Res. A
467/468, 91 (2001).
5) Vacuume Ultraviolet and Soft X-ray Synchroton Light
Source Project, Design Report (Japanese Society for
Synchrotron Radiation Research, Tokyo, 2002).
6) J. M. Wang: BNL-Rep. No.BNL-51302 (1980).

307

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RIKEN Accel. Prog. Rep. 37 (2004)

Measurement of rf characteristics of magnetic-alloy-loaded
cavity using cut-core configuration
M. Watanabe, Y. Chiba, K. Ohtomo,∗ H. Tsutsui,∗ T. Koseki, and T. Katayama
The accumulator cooler ring (ACR), a storage ringfor the accumulation and cooling of RI beams, is being studied at RIKEN.1) In the ACR, an rf stacking
method is used to capture injected RI beam bunches
and to accumulate the beam to suﬃcient intensity.2)
The stacking cavity is required to have a variable operation frequency from 20 to 40 MHz, rapid frequency
sweep width of up to 0.4 MHz within 6 ms and maximum rf voltage of 50 kV. A combination of mechanicaltuning of the center frequency and no-tuning broadband sweep around the center frequency using a low-Q
cavity is practical for our purpose. Recently, rf cavities
using magnetic alloy (MA) cores have been developed
at frequencies below 16 MHz.3–5) They have a marked
broadband feature because of the low Q value of the
MA cores. In the previous report,6) we presented themeasured characteristics of the MA cores in the frequency range from 0.1 to 40 MHz. The Q value of MA
is too low (less than 1) for use in the ACR stacking cavity, for which the Q value of several tens is suitable. To
increase the eﬀective Q value of a MA-loaded cavity,
the use of a cut core with air gaps has been studied
at several facilities.5,7) We have studied the rf characteristics of a cut-core-loaded cavity to examine its
practicability in the frequency region of the ACR.
We fabricated a test cavity which has a coaxial
structure comprising of copper as the outer conductor (O.D. = 450 mm) and aluminum as the inner conductor (I.D. = 132 mm). Figure 1 shows a schematicof the cut core in a test cavity. The core material is

FINEMET (FT-3M) which is an iron-based nanocrystalline magnetic alloy made by Hitachi Metals, Ltd.8)
The core is made of thin tape wound into a toroidal
shape. The tapes are coated with SiO2 for insulation.
The size of the core of 140 mm I.D., 300 mm O.D. and
10 mm height is the actual size of the core to be usedin the ACR stacking cavity. We set distances between
the core and the inner walls of the cavity to be morethan 5 mm to keep the stray capacitance small. The
equivalent circuit of the cavity can be represented using a parallel LCR circuit; the admittance is given by
Y = 1/Rsh + j(ωCg − 1/ωL),(1)

where Rsh is shunt impedance, Cg is parasitic capacitance and L is inductance of the cavity. The parasitic capacitance Cg is estimated to be approximately
30 pF.
We measured the admittance of the cut-core-loaded
cavity using a network analyzer (HP4195A) with an
impedance test kit (HP41951A) in the frequency range
from 1 to 50 MHz. Figures 2 and 3 show the gap dependences of Rsh and L, respectively. As shown in
Fig. 2, a larger gap width gives a smaller Rsh value ata lower frequency. On the other hand, Rsh does not
become very small by extending the gap width in thefrequency region of ACR. As can be seen in Fig. 3,
L remains almost constant with frequency for various
gap widths. We try to explain these results using
L = (µ0 d)(Ro − Ri)/(2g) + k,(2)

where µ0 is the permeability in vacuum, g is the air

Fig. 1. Test vessel and cut core.
∗308

Sumitomo Heavy Industries, Ltd.

Fig. 2. Frequency vs. shunt impedance of the cut-coreloaded cavity.

Figure 5 shows the relationship between the Q value
and the total gap length divided by the average magnetic path length, 2g/(2πr + 2g), for the frequency
as a parameter. In this ﬁgure, the open marks indicate the regular-sized core (I.D. = 140 mm, O.D. =300 mm, height = 10 mm) and the closed marks indicate a small-sized core, (I.D. = 140 mm, O.D. =200 mm, height = 25 mm). From the ﬁtted line, we
obtain the empirical formula,
Q = a[2g/(2πr + 2g)]b ,a = 86.0f −0.182 , b = 0.30f 0.236 ,Fig. 3. Frequency vs. inductance of the cut-core-loaded
cavity.

gap width between two circular halves of the core andRi, Ro, and d are the inner diameter, outer diameterand height of the core, respectively. This equation withk = 0 is generally used for the approximate calculationof the magnetic circuit with an air gap in the lowfrequency range. The k in Eq. (2) is introduced tocorrect the eﬀect of leakage ﬂux around the air gaps.
For example, at the air gap width of 150 mm, the ﬁrst
term of Eq. (2) is calculated to be 3.4 nH, while the kis estimated to be 15 nH. We found that k = 8.75 ×
10−9 (2g)−0.45 gives the best ﬁt of the measured data.
The values calculated using Eq. (2) are plotted in Fig. 3
using double open circles.
Figure 4 shows gap dependence of the Q value, whichis calculated by Q = Rsh/ωL. As can be seen fromthe ﬁgure, it is more eﬀective to expand the gap width
at higher frequency. The Q value of approximately 20,
which is the appropriate value for the ACR cavity, canbe obtained at 30 MHz by choosing the air gap widthof approximately 120 mm.

(3)

where f is in MHz.
In these measurements, the power fed into the cavity was as low as 0.3 mW. Additional measurements
at several higher input power levels up to 30 W for
FT-3M were carried out using an rf source and an external high-power directional coupler together with the
impedance analyzer. The measured results were almost the same as those of the low-power measurements
as expected. Since the rf characteristics of FT-3M arestable up to high rf magnetic ﬂux density of 0.2 T,9) the
obtained data can be utilized for designing an actual
cavity used at a high-power level.

Fig. 5. Q value of the cut-core-loaded cavity for frequency
as a parameter.

References

Fig. 4. Frequency vs. Q value of the cut-core-loaded cavity.

1) T. Katayama et al.: MUSES Conceptual Design Report(2000).
2) K. Ohtomo et al.: Proc. EPAC2000 (2000), p. 566.
3) Y. Mori et al.: Proc. EPAC98 (1998), p. 299.
4) M. Boehnke et al.: Proc. PAC1999 (1999), p. 851.
5) M. Yoshii et al.: Proc. EPAC2000 (2000), p. 984.
6) M. Watanabe et al.: RIKEN Accel. Prog. Rep. 36, 325(2003).
7) J. Dey et al.: Proc. PAC2001 (2001), p. 882.
8) Y. Yoshizawa et al.: J. Appl. Phys. 64, 6047 (1988).
9) Y. Tanabe et al.: Proc. APAC98 (1998), p. 390.

309

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RIKEN Accel. Prog. Rep. 37 (2004)

Development of an HTS-SQUID DC current monitor
T. Watanabe, S. Watanabe,∗1 T. Ikeda, Y. Sasaki,∗2 M. Kase, T. Kawaguchi,∗3 and T. Katayama
A highly sensitive cryogenic DC current monitor forthe measurement of the intensity of faint beams, suchas a radioisotope beam, was developed for the RIKEN
RI beam factory project.1–4) This monitor is composed of a high-temperature superconducting (HTS)
magnetic shield and an HTS current sensor including
an HTS superconducting quantum interference device(SQUID), which are cooled by a low-vibration pulsetube refrigerator. Since the principles of destructive
detectors are based on the interaction between the
beam and material, the beam is distorted by scattering or energy loss. However, the HTS-SQUID DC
current monitor can measure the beam current nondestructively and avoid those problems. Both the HTS
magnetic shield and the HTS current sensor based on
Bi2 -Sr2 -Ca2 -Cu3 -Ox (Bi-2223) were fabricated by dipcoating on a 99.9% MgO ceramic substrate. Recently,
a prototype of the HTS-SQUID monitor was completed
and we carried out the ﬁrst measurements using DC
heavy ion beams.
Prior to the measurements using heavy ion beams,
we carried out an oﬀ-line test. The ﬁrst output signal was observed using a feeding sine wave of 1 µA and1 Hz into a Cu rod which was set in the beam chamber.
Next, we conﬁrmed that the measured beam current
is not dependent on the beam position or beam radius by changing the position and the radius of the
Cu rod. The dynamic range of this monitor was measured by changing the simulated beam current which
was supplied into the Cu rod. The output voltage of
the SQUID electronics as a function of the simulated
beam current was measured and the dynamic range of
100 dB (from 1 µA to 0.1 A) was obtained by changing
the feedback gain of the SQUID electronics.5,6) Furthermore, in order to investigate noise sources, notonly the vibration originating from the ground but alsothat generated by the pulse-tube refrigerator itself wasanalyzed using accelerometers and an FFT in time andfrequency domains. As a result, the amplitude of thevibration was found to be within 6 µm at the frequency
band from 0.1 Hz to 20 Hz.
After completing the oﬀ-line test, we carried out
the ﬁrst beam test of the HTS-SQUID monitor which
was installed in the beam transport line for the ECR
ion source in the CNS experimental hall. The measurement was successfully performed and the system
was removed to the beam transport line (E1 experimental hall) of the RIKEN Ring Cyclotron (RRC) tomeasure the current of a high-energy heavy ion beam
∗1
∗2
∗3

310

Center for Nuclear Study, Graduate School of Science, University of Tokyo
Matsushita Electric Industrial Co. Ltd.
KT Science Ltd.

(Fig. 1). Figure 2 shows the measured signals of the
HTS-SQUID monitor (above) and those of the Faraday cup monitor (below) where a 7 µA H+ beam (a)and a 600 nA Ar17+
40 beam (b) were used. The beams
were pulsed and the zero level of the signals indicatedthat beams were stoped.
To improve the coupling between the input coil of
the SQUID and the magnetic ﬂux induced by the beam
current, we are investigating the possibility of fabricating the HTS coil at the bridge circuit, and introducing a high permeability core in the SQUID chip. We
aim to measure several nA beams nondestructively tomake the system applicable to physics and biology experiments, and an ion implanter.

Fig. 1. Beam transport line (E1 experimental hall) of the
RIKEN Ring Cyclotron (RRC).

Fig. 2. Measured signals of the HTS-SQUID monitor(above) and those of the Faraday cup monitor (below)
where a 7 µA H+ beam (a) and a 600 nA Ar17+beam
40(b) were used.

References
1) T. Watanabe et al.: RIKEN Accel. Prog. Rep. 35, 314(2002).
2) T. Watanabe et al.: Proc. 8th European Particle Accelerator Conf., Paris, France, 2002-6, (EPS-IGA, 2003)
p. 1995.
3) T. Watanabe et al.: RIKEN Accel. Prog. Rep. 36, 331(2003).

4) T. Watanabe et al.: CNS Annu. Rep. 59, 71 (2003).
5) T. Watanabe et al.: Proc. 6th European Conf. on Applied Superconductivity 2003 (EUCAS 2003), Sorrento,
Italy, 2003-9, to be published.
6) T. Watanabe et al.: Proc. 14th Symp. on Accelerator Science and Technology, Tsukuba, 2003-11, (KEK,2003) p. 99.

311

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RIKEN Accel. Prog. Rep. 37 (2004)

Feasibility of projectile-fragment-beam separation froma secondary beam in a storage ring†
M. Takanaka†

312

Condensed from the article in Proc. 14th Symp. on Accelerator Science and Technology, Tsukuba, 2003-11 (2003) p. 407.

10 2
10
1

10 3
10 2
10
1

0
∆τ/ητ

0.1
-3
x 10

10 4

0
∆τ/ητ

10 2
10
1

10

0
∆τ/ητ

10 2
10

0.1
-3
x 10

10 4

10 2
10
1

0
∆τ/ητ

0
∆τ/ητ

0.1
-3
x 10

0
∆τ/ητ

0.1
-3
x 10

0
∆τ/ητ

0.1
-3
x 10

0
∆τ/ητ

0.1
-3
x 10

10 3
10 2
10

0.1
-3
x 10

-0.1

10

10 3
10 2
10
1

-0.1

-0.1

1
-0.1

10 4

10 3

10

10 4

3

1
-0.1

10 2

0.1
-3
x 10

10 4

3

10 3

1
-0.1

No. of particles

-0.1

10

10 4
No. of particles

10 3

No. of particles∆p∆m
γ 2 ∆v
∆m
∆τ
=
+ 2 =
+ 2 ,
(2)
ητ
p
ηγ m
v
ηγt m

where v is the velocity, γ = 1/ 1 − v 2 /c2 , γt is thetransition gamma, and η is the slippage factor. If
ion species of beams with diﬀerent ∆m are extremely
stochastically cooled, they can all be overlapped inthe ∆τ /ητ space. When they are extremely electroncooled or the velocity spread δv/v = 0, they are separated by ∆m/ηγt2 m from the beam with ∆m = 0 in the∆τ /ητ space, or they circulate at their own revolution
frequencies in the ring. Therefore, a given ion speciesof a beam can be rf-captured after electron cooling.
Using 40,000 macroparticles, particle tracking has
been simulated in order to realize the separation pro-No. of particles

impedance when the transverse charge distribution isassumed to be Gaussian, and I k the beam current.
The revolution time τ of a particle with mass deviation ∆m and momentum deviation ∆p per charge has
the following deviation ∆τ :

10 4

10 4

No. of particles

sp

No. of particles

where s is the longitudinal coordinate, k the momentmode of the charge
distribution(monopole, dipole, and
quadrupole), Zk /n
the longitudinal space-charge

No. of particles

sp

No. of particles

k=0

cess after stochastic cooling (the series of electron cooling, rf capture, and acceleration). As a pre-cooled secondary beam, a 220 MeV/u beam of 55 Ni28+ , 53 Co27+ ,and 51 Fe26+ fragments with the sixfold-rms momentum spread of 10−3 and the rms transverse emittancesof 10−6 m rad starts to be electron-cooled. Simulated
results of electron cooling in Fig. 1 show that, after
electron cooling for 80 ms, the separation into the three
ion species of beams in the ∆τ /ητ space is dependent
on the secondary-beam current. The higher the beam
current, the larger the friction among ion species ofbeams that comes from the longitudinal charge-density
ﬂuctuation. Some of one ion species of a beam circulate together with the other ion species at their own
revolution frequencies.
The ∆τ /ητ separation between two neighboring
beams is 0.5 × 10−4 after cooling. It takes 7 ms to
rf-capture the 53 Co27+ beam, with the rf voltage linearly increasing from 0 V with time, to produce the
rf-bucket area of 4πδp/p = 1.2π × 10−4 (half-spreadδp/p = 0.3 × 10−4 ). The voltage reaches 66 V fora 180 m circumference of the ring and rf harmonics
h = 40. During the capture, electron cooling is repeatedly switched oﬀ for 0.1 ms and on for 0.2 ms inorder to suppress the whirling vortex of the bunched

No. of particles

An ion species of a beam is separated from a secondary beam of nuclear projectile fragments usuallyby using a projectile fragment separator in a transport
line. At Radioisotope Beam Factory, the separated
beam is planned to be injected and cooled in a storage
ring before it is used for colliding experiments.1) The
fragment separator has the side eﬀect of enhancing thetransverse emittance on the beam.2)
The new separation method proposed here, which
does not have the side eﬀect, is as follows. A secondary
beam of nuclear projectile fragments is injected into a
storage ring. After stochastic pre-cooling is applied tothe beam, electron cooling is applied in order to separate ion species of the beams in the longitudinal phasespace. A given ion species of the beam is rf-captured
and accelerated for the sake of horizontal separation.
The space-charge eﬀects on the separation have beenstudied using the simulation code that was developed
to study bunch shortening of an electron-cooled ion
beam.3) The longitudinal ﬁeld is calculated approximately as k
2i  Z
dI k
,
(1)
2π
n
ds

4

10 3
10 2
10
1

-0.1

0
∆τ/ητ

0.1
-3
x 10

-0.1

Fig. 1. Separation into ion species of beams in the ∆τ /ητ
space after electron cooling. The upper, the middle, andthe lower panels are for the secondary-beam currents of
1 mA, 0.1 mA, and 0.01 mA, respectively.

-2

x 10

-2

0.14

0.12

0.12
∆τ/ητ=∆p/p+∆m/ηγ m

0.14

0.1

2

0.02

0.06
0.04
0.02

0

0

-0.02

-0.02

∆τ/ητ

0.0015

100
75
50
25
0
-3.2

3.2
rf phase [rad]101-0.0002∆τ/ητ

0.0015

150
100
50
0
-3.2

3.2
rf phase [rad]

10
10

2

No. of particles

1-0.0002

10 2

3

10
1
-0.0002∆τ/ητ

0.0015
No. of particles

10

10

2
No. of particles

20
rf phase [rad]3

No. of particles

10-2
No. of particles

10

3

100
50
0
-3.2

3.2
rf phase [rad]

-2

10 4
10 3
10 2
10
1
-0.0002∆τ/ητ

0.0015

80
60
40
20
0
-3.2

3.2
rf phase [rad]

10

4

10

3

0
rf phase [rad]2
No. of particles

0.04

10 2
10
1
-0.0002∆τ/ητ

0.0015400

No. of particles

0.06

0.08

No. of particles

0.08

No. of particles

0.1

No. of particles

No. of particles

No. of particles∆τ/ητ=∆p/p+∆m/ηγ2m

x 10

300
200
100
0
-3.2

3.2
rf phase [rad]

10 3
10

2

10
1
-0.0002∆τ/ητ

0.0015

80
60
40
20
0
-3.2

3.2
rf phase [rad]Fig. 2. Longitudinal phase-space distribution after pre-acceleration. The left and the right panels are forthe secondary-beam currents of 1 mA and 0.1 mA, respectively.

beam in the rf bucket. Then, since the charge line density has few local peaks other than the main peak, thelongitudinal space-charge eﬀects can be lightened.
Pre-acceleration to make the momentum gain
∆p/p = 1.4 × 10−3 takes 17 ms with the rf-bucket area
ﬁxed and the electron-cooling turned oﬀ after the capture. The maximum rf voltage and synchronous phaseare 273 V and 20 degree, respectively. Simulation results of the acceleration in Fig. 2 reveal that during
the acceleration, the beam partially spills out of the rf
bucket for the secondary-beam current of 1 mA, but
not for that of 0.1 mA. Only the 55 Ni28+ and the51
Fe26+ beam that circulated at the 53 Co27+ revolution frequency at the end of electron cooling are seen
to contaminate the separated 53 Co27+ beam. The contamination rate is 2% for the secondary-beam currentof 0.1 mA. The contamination is avoided when thesecondary-beam current is less than about 0.01 mA, as
is seen from Fig. 1.
The acceleration separates the 53 Co27+ beam fromthe remaining beams by ∆p/p = 1 × 10−3 in the∆τ /ητ space, but not in the horizontal space because
the transverse emittance is not very small (rms =0.4 × 10−6 m rad for the secondary-beam current of
1 mA). Next acceleration has to be applied to the separated beam with a larger rf bucket area corresponding

to δp/p = 1 × 10−3 in order to make the separation
greater and faster. The required rf voltage is higher
by three orders than in the case of pre-acceleration.
There is the option to use lower h for bunching again
because the rf voltage can be high enough to shorten
the acceleration time.
In conclusion, simulations using a particle-tracking
simulation code have revealed that the novel separation of an ion species of a beam from a multicomponent beam in a storage ring has the following performance. The momentum of each ion species of abeam is not made perfectly monochromatic by electron
cooling when longitudinal friction due to the chargedensity ﬂuctuation is induced in the multicomponent
beam beyond a threshold of the secondary-beam current. Then, a species of a beam cannot be rf-captured
without contamination due to the other species. The
beam can be accelerated without spilling out of the rf
bucket below about ten times the threshold.
References
1) T. Katayama et al.: Nucl. Phys. A 626, 545 (1997).
2) C. C. Yun: RIKEN-AF-AC-30 (2001).
3) M. Takanaka: Phys. Rev. Spec. Top. Accel. Beams 6,104201 (2003).

313

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RIKEN Accel. Prog. Rep. 37 (2004)

Numerical simulation of crystalline ion beam
H. Tsutsui,∗1 T. Katayama, I. Meshkov,∗2 A. Sidorin,∗2 A. Smirnov,∗2 E. Syresin,∗2 and D. Möhl∗3
After a simulation code for crystalline ion beams wasdeveloped in 2002, the code was applied to some ionrings such as the ESR ring1) and the TARN-II ring.2)
This article is a summary of the results.3)
The ESR lattice functions and nominal parameters
are shown in Fig. 1 and Table 1, respectively. There
are two dispersion-free straight sections for electron
cooling. Moreover, in order to reduce the transition
gamma, dispersion function is high in the middle of thearc sections. Hence, the lattice functions are relatively
complicated. In this ring, the 1D crystalline state of103 − 104 ions was observed.1) The simulations using
this code are in good agreement with the experiments,
which were already shown last year.4)
Since we are interested in accumulating two ordersof magnitude more (typically N = 106 ) ions in the
1D crystalline state, we carried out simulations withincreased cooling rate, expecting beam cooling technology innovation in the near future (Fig. 2). From
the ﬁgure, N = 5 × 105 or more ions in the 1D stateFig. 2. Evolution of ion beam parameters during the cooling process for diﬀerent initial emittances, momentum
spreads, and cooling strengths, in the case of the ESR
ring. The cooling strengths are η = 4 × 10−2 (a, i),
2 × 10−2 (b, e, h), 5 × 10−3 (c, g), and 2 × 10−3 (d, f).
The straight line corresponds to the criterion Γ2 = π in
Ref. 3. N = 5 × 105 . The one dimensional crystalline
state is achieved when η ≥ 2 × 10−2 , irrespective of theinitial beam emittance and momentum spread.

can be achieved using an eﬀective cooling system (a,b, e, h, i). Also, it is interesting that there is a forbidden low-momentum-spread region where the beam
parameters make a detour (a, b, c, d). This is considered to be due to heating in the longitudinal direction
by intrabeam scattering5) and longitudinal-horizontal
coupling.
The TARN-II ring is considered to be desirable formaking 2D or 3D crystalline states because the phaseadvance per cell can be lower than π/2 by changing thestrengths of the quadrupoles.6) The lattice functions of
this ring are shown in Fig. 3, which are more regularFig. 1. Lattice functions of ESR.

Table 1. Nominal ring parameters used for the simulation
study.

Circumference (m)Super-periodicity
Transition gamma
Tune (H/V)
Ion species
Energy (MeV/u)
∗1
∗2
∗3

314

ESR
TARN-II
108.36
77.76
2
6
2.59
1.88
2.27/2.27 1.67/1.81
197
Au79+
360

Sumitomo Heavy Industries, Ltd.
Joint Institute for Nuclear Research, Russia
European Organization for Nuclear Research (CERN),
Switzerland

Fig. 3. Lattice functions of TARN-II.

than those of the ESR. We carried out simulations
with nominal parameters as shown in Table 1.
The results are shown in Fig. 4. As in the ESR case,more than N = 5×105 particles can be accumulated in
the 1D crystalline state, by using an eﬀective coolingsystem. The diﬀerence between the two cases is thatthe required cooling strength for the TARN-II is relatively lower than that for the ESR. This is considered
to come from the lattice ﬂatness. Figure 5 shows thenumber of stored ions in the 1D crystalline state as

Fig. 5. Number of stored ions in the TARN-II ring asa function of longitudinal cooling strength (transverse
ones are 10 times less), with (Yes) and without (No)ordering.

a function of the longitudinal cooling strength, in thecase of the TARN-II ion ring. The number of particles
is proportional to the strength at low cooling strengthand saturates at around N = 106 . This saturation isconsidered to be due to the space charge tune shift.7)
Fig. 4. Evolution of ion beam parameters during the cooling process for diﬀerent initial emittances, momentum
spreads, and cooling strengths, in the case of the TARNII ion ring. The cooling strengths are η = 2×10−2 (a, f),
5×10−3 (b, e), and 2×10−3 (c, d). The straight line corresponds to the criterion Γ2 = π in Ref. 3. N = 5 × 105 .
The one dimensional crystalline state is achieved whenη ≥ 5 × 10−3 , irrespective of the initial beam emittanceand momentum spread.

References
1) M. Steck et al.: Phys. Rev. Lett. 77, 3803 (1996).
2) A. Noda: Proc. PAC87 (1987), p. 845.
3) I. Meshkov et al.: RIKEN-AF-AC-42 (2003).
4) H. Tsutsui et al.: RIKEN Accel. Prog. Rep. 36, 327(2003).
5) J. D. Bjorken and S. K. Mtingwa: Part. Accel. 13, 115(1983).
6) H. Okamoto: Private communication.
7) D. Möhl and T. Katayama: RIKEN-AF-AC-40 (2002).

315

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RIKEN Accel. Prog. Rep. 37 (2004)

Routine work for radiation safety in the ring cyclotron facility
Y. Uwamino, S. Fujita, S. Ito, H. Sakamoto, T. Yamaki, T. Ito,∗1 T. Nakamura,∗2
T. Iwasa,∗2 and M. Kase
We report here the residual radioactivity and leakage
radiation level at the Ring Cyclotron Facility.
Residual radioactivities in the Ring Cyclotron Facility were measured at various locations using ionizationchamber survey meters.
The measurements were performed almost after every beam experiment as well as during the routine overhaul period. The routine overhaul period started immediately after the experiment which was carried out
with the 12 C beam of 92 MeV/nucleon in the E6 experimental vault from July 22 to 31, 2003. The dose
rates at the deﬂectors in the injector AVF cyclotron
and the Ring Cyclotron were found to be 0.5 mSv/h
on Aug. 8, 2003 and 15 mSv/h on Aug. 29, 2003, respectively, during the overhaul period.
In addition to the above routine measurement, dose
rates inside the injector AVF cyclotron were measured
on March 19, 2003 after the new deﬂector had been
installed and operated for a week. The dose rates were
3.5 mSv/h at the deﬂector and 4.0 mSv/h at the magnetic channel. A minor rearrangement was done withthe deﬂector after the measurement.

During the period from Oct. 1, 2002 to Sept. 30,
2003, the dose rates were measured along the beamlines. Spots a–z, marked by bullets in Fig. 1, are theplaces where the dose rates exceeded 30 µSv/h. Table 1 summarizes the observed dose rates and gives
the dates when the measurements were performed.
The maximum dose rate was found to be 20 mSv/h(20000 µSv/h) at the beam duct in the beam distribution corridor denoted by o in Fig. 1. Whenever weobserved a high dose rate, we roped oﬀ the area andposted a sign warning that it was dangerous to remain
for a long time in that place.
We also continuously monitored the leakage radiation from the Ring Cyclotron Facility. Having analyzed the collected data of leakage neutrons, we foundthat the radiation levels in the controlled area weremuch lower than the allowable dose limit. The leakage of γ-rays and neutrons was below the detection
limit of the environmental monitors. We evaluated theradiation level at the boundary of the accelerator facility using the monitor which was installed in the computer room on the ground ﬂoor immediately above a

Fig. 1. Layout of the RIKEN Ring Cyclotron Facility as of 2003. Measured locations of residual radioactivities along the beam lines are shown by bullets a–z.
∗1
∗2

Science Service, Inc.
Tokyo University of Science317

Table 1. Summary of the dose rates measured along thebeam lines with ionization-chamber survey meters. Detection points a–z indicate the measured locations
shown in Fig. 1.

Fig. 2. Annual total number of persons who entered the
Nishina radiation controlled area.

bending magnet which guided the beams from the ring
cyclotron vault to the distribution corridor. As a result, we obtained a radiation level of approximately
5 µSv/year which was much lower than the allowable
dose limit (1 mSv/year).
The routine operation of the Ring Cyclotron wasstarted in April, 1987, and many experimenters, workers and visitors have entered the Nishina radiation con-318

Fig. 3. Annual total number of visitors to Nishina radiation controlled area. “Visitors” do not include experimenters and workers.

trolled area. The annual total numbers of persons andvisitors that entered the area are shown in Figs. 2 and3, which are about 35000 and about 1500, respectively;
their grand total numbers since 1987 are 497204 and20230.

Back to Contents

VI. LIST OF PUBLICATIONS
1. Accelerator
physics

development

andaccelerator

Y. Matsuda, K. Nagamine, T. Matsuzaki, K. Ishida, I.
Watanabe, S. Nakamura, N. Kawamura, P. Bakule,P. Strasser, F. L. Pratt, Y. Miyake, K. Simomura,
S. Makimura, and G. H. Eaton: “Upgrading the
RIKEN-RAL Muon Facility”, Hyperﬁne Interact.
138, 489–495 (2001).
S. Kohara, A. Goto, O. Kamigaito, M. Kase, N.
Sakamoto, S. Watanabe, and T. Katayama: “Construction of the ﬂat-top acceleration system in the
RIKEN AVF cyclotron”, Proc. 13th Symp. on Accelerator Science and Technology, (RCNP, Osaka University), Suita, 2001–10, RCNP, Osaka University,
Suita, pp. 235–237 (2001).
Y. Yano: “RIKEN RI beam factory project”, Ind. J.
Phys. 76S, 1–7 (2002).
H. Ueno and K. Asahi: “Production of radioactive
ion beams in the RIBF-RIPS conﬁguration”, Proc.
RIKEN Symp. on Condensed Matter Studies with
Radioactive Ion Beams, Wako, 2002–2, edited by K.
Asahi, Y. Kobayashi, and W. Sato, RIKEN, Wako,
pp. 54–58 (2002).
H. Watanabe: “High-spin isomer beams at RARF”,
Proc. RIKEN Symp. on Condensed Matter Studies
with Radioactive Ion Beams, Wako, 2002–2, editedby K. Asahi, Y. Kobayashi, and W. Sato, RIKEN,
Wako, pp. 67–70 (2002).
T. Watanabe, M. Kase, and T. Katayama: “Development of a highly sensitive beam current monitor with a SQUID and superconducting magnetic
shield”, Cryogenic Eng. 38, 509–521 (2003).
M. Kidera, T. Nakagawa, S. Enomoto, K. Takahashi,
R. Hirunuma, K. Igarashi, T. Ohyama, M. Fujimaki,
E. Ikezawa, O. Kamigaito, M. Kase, and Y. Yano:“Accelerator mass spectrometry using electron cyclotron resonance ion source and heavy ion accelerator”, Nucl. Study 48, 163–170 (2003).
M. Takanaka: “Instability during bunch shortening ofan electron-cooled beam”, Phys. Rev. Spec. Top.:
Accel. Beams 6, 104201-1–104201-10 (2003).
M. Takanaka: “Feasibility of separation of an ion
species of beam from a secondary beam in a storage ring”, Proc. 14th Symp. on Accelerator Scienceand Technology, (KEK), Tsukuba, 2003–11, KEK,
Tsukuba, pp. 407–409 (2003).
O. Kamigaito, M. Kase, N. Sakamoto, E. Ikezawa,
S. Kohara, M. Fujimaki, T. Nakagawa, M. Kidera,
Y. Higurashi, H. Ryuto, Y. Chiba, M. Hemmi, Y.
Miyazawa, T. Chiba, T. Aihara, T. Ohki, H. Hasebe,
H. Yamauchi, A. Uchiyama, K. Oyamada, A. Goto,
and Y. Yano: “Present status of the RIKEN heavyion linac”, Proc. 14th Symp. on Accelerator Scienceand Technology, (KEK), Tsukuba, 2003–11, KEK,

Tsukuba, pp. 708–710 (2003).
S. Ozawa and M. Hamagaki: “Preparation of selfsupporting boron ﬁlms by electron-beam-excitedplasma”, Proc. 20th Symp. on Plasma Processing,(Division of Plasma Electronics, The Japan Societyof Applied Physics), Nagaoka, 2003–1, The Japan
Society of Applied Physics, Tokyo, pp. 283–284(2003).
O. Kamigaito, M. Kase, E. Ikezawa, S. Kohara, N.
Sakamoto, M. Fujimaki, T. Nakagawa, M. Kidera,
Y. Higurashi, Y. Chiba, M. Hemmi, Y. Miyazawa, T.
Chiba, T. Aihara, T. Ohki, H. Hasebe, H. Yamauchi,
A. Uchiyama, K. Oyamada, and Y. Yano: “Present
status of the RIKEN heavy-ion linac”, Proc. 28th
Linear Accelerator Meet. in Japan (LAM28), (JPARC and others), Tokai-mura, 2003–7〜8, JAERI,
Tokai-mura, pp. 22–24 (2003).
T. Kikuchi, M. Nakajima, K. Horioka, and T.
Katayama: “Transverse particle distributions of intense beams after ﬁnal bunching for heavy ion inertial fusion”, J. Plasma Fusion Res. 80, 87–88 (2004).

2.

Nuclear physics and nuclear instrumentation

K. Asahi, H. Ogawa, K. Sakai, A. Yoshimi, M. Tsuda,
Y. Uchiyama, T. Suzuki, K. Suzuki, N. Kurokawa,
M. Adachi, A. Yoshida, S. Fukuda, M. Notani, T.
Kubo, H. Okuno, H. Sato, N. Fukunishi, N. Aoi,
K. Yoneda, H. Iwasaki, N. Fukuda, M. Ishihara,
H. Izumi, H. Ueno, T. Shimoda, S. Tanimoto, N.
Takahashi, H. Miyatake, W.-D. Schmidt-Ott, and
M. Schaefer: “Nuclear moments measurements withpolarized radioactive beams”, Application of Lasersin Atomic Nuclei Research: Proc. 4th Int. Workshop of Laser Spectroscopy on Beams of Radioactive Nuclei, (Joint Institute for Nuclear Research),
Poznan, Poland, 1999–5, Joint Institute for Nuclear
Research, Dubna, pp. 127–134 (2000).
H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:“Relativistic mean ﬁeld description for the shears
band mechanism in 84 Rb”, Phys. Rev. C 62,
061301(R)-1–061301(R)-5 (2000).
T. Suzuki and GSI-RIKEN-Kurchatov-Comenius Collaboration: “Measurements of interaction cross sections for nuclei far from stability at relativistic energies”, AIP Conf. Proc. 561, 259–268 (2001).
K. Asahi, K. Sakai, H. Ogawa, H. Ueno, Y. Kobayashi,
A. Yoshimi, H. Miyoshi, K. Yogo, A. Goto, T. Suga,
N. Imai, Y. Watanabe, K. Yoneda, N. Fukuda, N.
Aoi, W.-D. Schmidt-Ott, G. Neyens, S. Teughels,
A. Yoshida, T. Kubo, and M. Ishihara: “Nuclear
moment studies with polarized radioactive nuclear
beams”, AIP Conf. Proc. 570, 109–118 (2001).
H. Ogawa, K. Sakai, H. Ueno, T. Suzuki, K. Asahi, H.
Miyoshi, M. Nagakura, K. Yogo, A. Goto, T. Suga,

319

T. Honda, N. Imai, Y. Watanabe, K. Yoneda, A.
Yoshimi, N. Fukuda, N. Aoi, Y. Kobayashi, W.-D.
Schmidt-Ott, G. Neyens, S. Teughels, A. Yoshida, T.
Kubo, and M. Ishihara: “Eﬀective charge anomaly
in neutron-rich nuclei revealed from spin-polarized
RI beam experiments”, AIP Conf. Proc. 570, 679–
683 (2001).
K. Asahi, Y. Kobayashi, H. Ueno, A. Yoshimi, W.
Sato, H. Watanabe, H. Miyoshi, and D. Kameda:“Radioactive ion beams as microscopic probes into
matter”, Anal. Sci. 17, No. Suppl., i613–i616 (2001).
K. Asahi, H. Ogawa, H. Ueno, Y. Kobayashi, W.
Sato, A. Yoshimi, H. Watanabe, D. Kameda, H.
Miyoshi, K. Sakai, N. Imai, K. Yoneda, Y. Watanabe, N. Fukuda, N. Aoi, A. Yoshida, T. Kubo, and
M. Ishihara: “Nuclear moment studies with polarized radioactive nuclear beams”, Hyperﬁne Interact.
136/137, 183–187 (2001).
H. Ueno, W. Sato, H. Ogawa, N. Aoi, K. Yoneda, Y.
Kobayashi, D. Kameda, H. Miyoshi, H. Watanabe,
N. Imai, A. Yoshimi, J. Kaihara, and K. Asahi: “Development of a detector system for transient ﬁeld experiments with radioactive isotope beams and a test
experiment”, Hyperﬁne Interact. 136/137, 211–214(2001).
M. Kato, H. Sugai, T. Hayashi, M. Nishi, M. Tanase,
T. Matsuzaki, K. Ishida, and K. Nagamine: “Development of a compact tritium gas recycling system”,
Hyperﬁne Interact. 138, 397–401 (2001).
J. Schaﬀner-Bielich, D. Kharzeev, L. Mclerran, and R.
Venugopalan: “Generalized scaling of the transverge
mass spectrum at the relativistic heavy-ion collider”,
Nucl. Phys. A 705, 494–507 (2001).
R. Kanungo, I. Tanihata, and A. Ozawa: “Possibilityof enlarged core structure of N = 15 neutron richnuclei”, Phys. Lett. B 512, 261–267 (2001).
S. Sugimoto, K. Sumiyoshi, and H. Toki: “Relativistic Hartree-Bogoliubov approach for nuclear matterwith nonlinear coupling terms”, Phys. Rev. C 64,
054310-1–054310-5 (2001).
K. Asahi: “RIKEN radioactive beam facility and polarized radioactive beams”, Prog. Part. Nucl. Phys.
46, 321–333 (2001).
A. Saito, S. Takeuchi, T. Motobayashi, Y. Ando, T.
Gomi, Y. Higurashi, H. Kobayashi, M. Serata, K.
Yamada, S. Shimoura, H. Iwasaki, M. Kurokawa,
T. Teranishi, H. Ryuto, T. Minemura, S. Ozawa,
Y. Yanagisawa, M. Ishihara, N. Aoi, H. Sakurai,
Z. Fulop, M. Hirai, Y. Iwata, N. Iwasa, and Z.
Liu: “Molecular states in neutron-rich beryllium
isotopes”, Clustering Aspects of Quantum Manybody Systems: Proc. Int. Symp. on Post-Symp. of
YKIS01, Kyoto, 2001–11, edited by A. Ohonishi
and others, World Scientiﬁc, Singapore, pp. 39–42(2002).
H. Ogawa, K. Asahi, H. Ueno, K. Sakai, H. Miyoshi,
D. Kameda, T. Suzuki, H. Izumi, N. Imai, Y.

320

Watanabe, K. Yoneda, N. Fukuda, H. Watanabe, A.
Yoshimi, W. Sato, N. Aoi, M. Nagakura, T. Suga,
K. Yogo, A. Goto, T. Honda, Y. Kobayashi, W.-D.
Schmidt-Ott, G. Neyens, S. Teughels, A. Yoshida,
T. Kubo, and M. Ishihara: “Quenching of neutron
E2 eﬀective charge in neutron-rich nuclei and theground state of 17 C”, Eur. Phys. J. A 13, 81–85(2002).
A. Saito, S. Shimoura, S. Takeuchi, T. Motobayashi,
H. Ryuto, Y. Ando, N. Aoi, Z. Fulop, T. Gomi, Y.
Higurashi, M. Hirai, N. Iwasa, H. Iwasaki, Y. Iwata,
H. Kobayashi, M. Kurokawa, Z. Liu, T. Minemura,S. Ozawa, H. Sakurai, M. Serata, T. Teranishi, K.
Yamada, Y. Yanagisawa, and M. Ishihara: “Molecular states in 12 Be and 14 Be”, Exotic Nuclei andAtomic Masses: Proc. 3rd Int. Conf. on Exotic Nuclei and Atomic Masses (ENAM2001), (Departmentof Physics and Accelerator Laboratory of Universityof Jyvaskyla), Hameenlinna, Finland, 2001–7, edited
by J. Aysto and others, Springer Verlag, Heidelberg,
p. 251 (2002).
H. Koura, T. Tachibana, and M. Yamada: “Estimation of alpha-decay half-lives and ﬁssion barriersin the superheavy nuclidic region from the viewpoint of a new mass formula”, Exotic Nuclei andAtomic Masses: Proc. 3rd Int. Conf. on Exotic Nuclei and Atomic Masses (ENAM2001), (Departmentof Physics and Accelerator Laboratory of Universityof Jyvaskyla), Hameenlinna, Finland, 2001–7, edited
by J. Aysto and others, Springer-Verlag, Heidelberg,
p. 379 (2002).
H. L. Yadav, S. Sugimoto, and H. Toki: “Relativistic
mean ﬁeld plus BCS approach to drip-line nuclei”,
Mod. Phys. Lett. A 17, 2523–2533 (2002).
T. Wakasa, K. Hatanaka, T. Kawabata, T. Noro,
H. Sakaguchi, M. Yosoi, Y. Fujita, G. Berg,
T. Fujimura, H. Fujita, M. Ito, J. Kamiya, K.
Nagayama, Y. Shimbara, H. Takeda, K. Tamura, H.
Ueno, M. Uchida, and M. Uraki: “High resolution
beam line for the grand raiden spectrometer”, Nucl.
Instrum. Methods Phys. Res. A 482, 79–93 (2002).
H. Fujita, Y. Fujita, G. Berg, A. Bacher, C. Foster,K. Hara, K. Hatanaka, T. Kawabata, T. Noro, H.
Sakaguchi, Y. Shimbara, T. Shinada, E. Stephenson,
H. Ueno, and M. Yosoi: “Realization of matchingconditions for high-resolution spectrometers”, Nucl.
Instrum. Methods Phys. Res. A 484, 17–26 (2002).
K. Asahi, K. Sakai, H. Ogawa, H. Miyoshi, K. Yogo, A.
Goto, T. Suga, H. Ueno, Y. Kobayashi, A. Yoshimi,
A. Yoshida, T. Kubo, Y. Watanabe, N. Imai, K.
Yoneda, N. Fukuda, N. Aoi, M. Ishihara, W.-D.
Schmidt-Ott, G. Neyens, and S. Teughels: “Electromagnetic moments of neutron-rich nuclei measured
with polarized radioactive ion beams”, Nucl. Phys.
A 704, 88c–97c (2002).
H. Ueno, A. Yoshimi, W. Sato, H. Watanabe, K.
Yoneda, Y. Kobayashi, A. Yoshida, T. Kubo, M.

Ishihara, K. Asahi, H. Ogawa, H. Miyoshi, D.
Kameda, T. Suga, K. Ohno, K. Sakai, K. Yogo,
and N. Imai: “Magnetic moment of the groundstate of 17 C”, Perspectives in Heavy Ion Physics:
Proc. 4th Italy-Japan Symp., Wako, Tokyo, 2001–9,
edited by K. Yoshida, S. Kubono, I. Tanihata, and
C. Signorini, World Scientiﬁc, Singapore, pp. 77–84(2002).
S. Motomura, Q. Pan, Y. Gounou, Y. F. Yang,
S. Enomoto, Y. Yano, and K. Asahi: “Compton camera for multitracer”, Perspectives in Heavy
Ion Physics: Proc. 4th Italy-Japan Symp., Wako,
Tokyo, 2001–9, edited by K. Yoshida, S. Kubono, I.
Tanihata, and C. Signorini, World Scientiﬁc, Singapore, pp. 439–447 (2002).
A. Yoshimi, K. Asahi, K. Sakai, K. Yogo, H. Ogawa,
M. Tsuda, T. Suzuki, and M. Nagakura: “Nuclear
spin maser with an artiﬁcial feedback mechanism”,
Phys. Lett. A 304, 13–20 (2002).
R. Kanungo, I. Tanihata, and A. Ozawa: “Observationof new neutron and proton magic numbers”, Phys.
Lett. B 528, 58–64 (2002).
S. Fujii, R. Okamoto, and K. Suzuki: “Shell-model cal17
culations for 16
Λ O and Λ O using microscopic eﬀective
interactions with Σ degrees of freedom”, Phys. Rev.
C 66, 054301-1–054301-10 (2002).
M. Kitazawa, T. Koide, T. Kunihiro, and Y. Nemoto:“Precursor of color superconductivity in hot quark
matter”, Phys. Rev. D 65, 091504(R)-1–091504(R)5 (2002).
T. T. Takahashi, H. Suganuma, Y. Nemoto, and H.
Matsufuru: “Detailed analysis of the three-quark
potential in SU(3) lattice QCD”, Phys. Rev. D 65,
114509-1–114509-19 (2002).
R. Kanungo, T. Suda, M. Chiba, N. Iwasa, S.
Nishimura, A. Ozawa, C. Samanta, T. Suzuki, T.
Yamaguchi, T. Zheng, and I. Tanihata: “Experimental evidence of core modiﬁcation in the near
drip-line nucleus 23 O”, Phys. Rev. Lett. 88, 1425021–142502-4 (2002).
H. Miyoshi, H. Ueno, K. Asahi, H. Ogawa, J. Murata,
K. Sakai, D. Kameda, Y. Kobayashi, W. Sato, A.
Yoshimi, H. Watanabe, K. Yoneda, N. Imai, J.
Kaihara, K. Shimada, and T. Koike: “Developmentof low energy polarized atomic beam”, Proc. RIKEN
Symp. on Condensed Matter Studies with Radioactive Ion Beams, Wako, 2002–2, edited by K. Asahi,
Y. Kobayashi, and W. Sato, RIKEN, Wako, pp. 61–
66 (2002).
W. Sato, H. Ueno, H. Watanabe, H. Ogawa, H.
Miyoshi, N. Imai, A. Yoshimi, K. Yoneda, D.
Kameda, Y. Kobayashi, and K. Asahi: “On-line
TDPAC studies using the 19 O beam”, Proc. RIKEN
Symp. on Condensed Matter Studies with Radioactive Ion Beams, Wako, 2002–2, edited by K. Asahi,
Y. Kobayashi, and W. Sato, RIKEN, Wako, pp. 71–
75 (2002).

H. Toki, S. Sugimoto, and K. Ikeda: “Relativistic
mean-ﬁeld theory with the pion in ﬁnite nuclei”,
Prog. Theor. Phys. 108, 903–916 (2002).
M. Kitazawa, T. Koide, T. Kunihiro, and Y. Nemoto:“Chiral and color-superconducting phase transitions
with vector interaction in a simple model”, Prog.
Theor. Phys. 108, 929–951 (2002).
K. Iida, G. Watanabe, and K. Sato: “Formation of
nuclear “pasta” in cold neutron star matter”, Prog.
Theor. Phys. Suppl., No. 146, pp. 514–519 (2002).
A. Kohama, R. Seki, A. Arima, and S. Yamaji:“Model-independent determination of surface density distribution of unstable nuclei at radioactive
beam facilities”, Prog. Theor. Phys. Suppl., No. 146,
pp. 577–578 (2002).
H. Ogawa, K. Asahi, H. Ueno, H. Miyoshi, D. Kameda,
N. Imai, K. Yoneda, H. Watanabe, T. Suga, K.
Ohno, A. Yoshimi, W. Sato, K. Sakai, K. Yogo, Y.
Kobayashi, A. Yoshida, T. Kubo, and M. Ishihara:“Assignment of the ground-state spin-parity for 17 C
through g-factor measurement”, Prog. Theor. Phys.
Suppl., No. 146, pp. 607–608 (2002).
A. Saito, S. Shimoura, S. Takeuchi, T. Motobayashi,
H. Ryuto, Y. Ando, N. Aoi, Z. Fulop, T. Gomi, Y.
Higurashi, M. Hirai, N. Iwasa, H. Iwasaki, Y. Iwata,
H. Kobayashi, M. Kurokawa, Z. Liu, T. Minemura,S. Ozawa, H. Sakurai, M. Serata, T. Teranishi, K.
Yamada, Y. Yanagisawa, and M. Ishihara: “Molecular states in neutron-rich beryllium isotopes”, Prog.
Theor. Phys. Suppl., No. 146, pp. 615–616 (2002).
Y. Motizuki: “Description: Element genesis - Solving the mystery (Video) revised ed.”, Image Science,
Inc., Tokyo, (2002).
K. Sekiguchi, H. Sakai, H. Okamura, A. Tamii, T.
Uesaka, K. Suda, N. Sakamoto, T. Wakasa, Y.
Satou, T. Ohnishi, K. Yako, S. Sakoda, H. Kato,
Y. Maeda, J. Nishikawa, T. Saito, N. Uchigashima,
N. N. Kalantar, and K. Ermisch: “Polarizationtransfer measurement for d-p elastic scattering: aprobe for three nucleon force properties”, AIP Conf.
Proc. 675, 711–714 (2003).
H. Madokoro, T. Shimizu, and Y. Motizuki: “Global
anisotropy versus small-scale ﬂuctuations in neutrino ﬂux in core-collapse supernova explosions”, Astrophys. J. 592, 1035–1041 (2003).
N. Dinh Dang: “Energies of the ground state andﬁrst excited 0+ state in an exactly solvable pairingmode”, Eur. Phys. J. A 16, 181–191 (2003).
S. Motomura and S. Enomoto: “Development of multinuclide γ-ray emission imaging system GREI”, J.
Clin. Exp. Med. 205, 884–886 (2003).
K. Ishida, K. Nagamine, T. Matsuzaki, and N.
Kawamura: “Muon catalyzed fusion”, J. Phys. G
29, 2043–2045 (2003).
A. Kohama, R. Seki, A. Arima, and S. Yamaji: “Determination of matter surface distribution of neutronrich nuclei”, J. Phys. Soc. Jpn. 72, 2766–2780321

(2003).
W. Sato, H. Ueno, H. Watanabe, H. Ogawa, H.
Miyoshi, N. Imai, A. Yoshimi, K. Yoneda, D.
Kameda, Y. Kobayashi, and K. Asahi: “On-line
TDPAC studies with the 19 O beam”, J. Radioanal.
Nucl. Chem. 255, 183–186 (2003).
K. Sekiguchi, H. Sakai, H. Okamura, A. Tamii, T.
Uesaka, K. Suda, N. Sakamoto, T. Wakasa, Y.
Satou, T. Ohnishi, K. Yako, S. Sakoda, H. Kato,
Y. Maeda, M. Hatano, J. Nishikawa, T. Saito, N.
Uchigashima, N. N. Kalantar, and K. Ermisch: “Polarization transfer measurement for d-p elastic scattering: To search for three nucleon force eﬀects”,
Mod. Phys. Lett. A 18, 327–329 (2003).
S. Yonai, T. Kurosawa, H. Iwase, H. Yashima, Y.
Uwamino, and T. Nakamura: “Measurement of neutrons from thick Fe target bombarded by 210 MeV
protons”, Nucl. Instrum. Methods Phys. Res. A 515,
733–744 (2003).
T. Motobayashi: “RI beam factory project at
RIKEN”, Nucl. Instrum. Methods Phys. Res. B 204,
736–738 (2003).
T. Motobayashi: “Nuclear astrophysics experimentswith high energy RI beams”, Nucl. Phys. A 718,
101c–108c (2003).
K. Oyamatsu and K. Iida: “Empirical properties ofasymmetric nuclear matter to be obtained from unstable nuclei”, Nucl. Phys. A 718, 363c–366c (2003).
H. Madokoro, T. Shimizu, and Y. Motizuki: “Effects of anisotropy in neutrino radiation on the supernova explosion: More complicated patterns ofanisotropy”, Nucl. Phys. A 718, 458c–460c (2003).
K. Iida and G. Baym: “Magnetic and rotational vortices in superﬂuid quark matter”, Nucl. Phys. A
718, 697c–699c (2003).
T. Motobayashi: “Coulomb dissociation studies for explosive hydrogen burning”, Nucl. Phys. A 719, 65c–
72c (2003).
Z. Elekes, G. Kalinka, Z. Fulop, J. Gal, J. Molnar,
G. Hegyesi, D. Novak, J. Vegh, T. Motobayashi, A.
Saito, and Y. Yanagisawa: “Optimization of the performance of a CsI(Tl) scintillator + Si PIN photodiode detector for medium-energy light-charged particle hybrid array”, Nucl. Phys. A 719, 316c–321c(2003).
K. Sekiguchi, H. Sakai, H. Okamura, A. Tamii, T.
Uesaka, K. Suda, N. Sakamoto, T. Wakasa, Y.
Satou, T. Ohnishi, K. Yako, S. Sakoda, H. Kato,
Y. Maeda, J. Nishikawa, T. Saito, N. Uchigashima,
N. N. Kalantar, and K. Ermisch: “Polarizationtransfer measurement for d-p scattering and three
nucleon force eﬀects”, Nucl. Phys. A 721, 637c–640c(2003).
S. Sugimoto, H. Toki, and K. Ikeda: “Surface pion
condensation in ﬁnite nuclei”, Nucl. Phys. A 721,
669c–672c (2003).
K. Tanida, H. Akikawa, Y. Fukao, H. Hotchi, K. Imai,

322

Y. Miura, K. Miwa, K. Mizunuma, S. N. Nakamura,
M. Niiyama, S. Ota, S. K. Pranab, H. Takahashi, T.
Takahashi, H. Tamura, S. Terashima, M. Togawa,and M. Ukai: “High-resolution γ-ray spectroscopy
of hyperfragments produced by stopped κ reactios”,
Nucl. Phys. A 721, 999c–1002c (2003).
S. Sugimoto, H. Toki, K. Ikeda, and N. P. Minkov:“Relativistic mean ﬁeld theory with the pion for ﬁnite nuclei”, Nucl. Phys. A 722, 360c–365c (2003).
N. Dinh Dang and A. Arima: “Thermal quasiparticle correlations and continuum coupling in nuclei
far from stability”, Nucl. Phys. A 722, 383c–388c(2003).
T. Yamaguchi, T. Zheng, A. Ozawa, M. Chiba, R. Kanungo, T. Kato, K. Morimoto, T. Ohnishi, T. Suda,
Y. Yamaguchi, A. Yoshida, K. Yoshida, and I. Tanihata: “Momentum distributions of 14 C and 15 C fragments from 16 C breakup”, Nucl. Phys. A 724, 3–13
(2003).
G. Watanabe, K. Iida, and K. Sato: “Erratum to:I. ‘thermodynamic properties of nuclear “pasta” inneutron star crusts’ [Nucl. Phys. A 676 (2000) 455]
and II. ‘Eﬀects of neutrino trapping on thermodynamic properties of nuclear “pasta”’ [Nucl. Phys.
A 687 (2001) 512]”, Nucl. Phys. A 726, 357–365(2003).
H. Watanabe, H. Ueno, D. Kameda, W. Sato, A. .
Yoshimi, H. Miyoshi, T. Kishida, Y. Kobayashi, A.
Odahara, Y. Gounou, and K. Asahi: “g-Factor of thehigh-spin isomer in 149 Dy and a multi-quasiparticle
conﬁguration caused by the N = 82 core excitations”, Nucl. Phys. A 728, 365–378 (2003).
K. Sekiguchi, H. Sakai, H. Okamura, A. Tamii, T.
Uesaka, K. Suda, N. Sakamoto, T. Wakasa, Y.
Satou, T. Ohnishi, K. Yako, S. Sakoda, H. Kato,
Y. Maeda, J. Nishikawa, T. Saito, N. Uchigashima,
N. N. Kalantar, and K. Ermisch: “Polarizationtransfer measurement for deuteron-proton scatteringand three nucleon force eﬀects”, Nuclear Many-Body
and Medium Eﬀects in Nuclear Interactions and Reactions: Proc. Kyudai-RCNP Int. Symp., (Osaka
University RCNP and Kyushu University), Fukuoka,
2003–10, edited by K. Hatanaka, T. Noro, K. Sagara,
and others, World Scientiﬁc, Singapore, pp. 115–119(2003).
T. Matsuzaki, K. Nagamine, N. Kawamura, K. Ishida,
Y. Matsuda, S. Nakamura, M. Kato, H. Sugai, M.
Tanase, K. Kudo, N. Takeda, and G. H. Eaton: “Evidence for strong n-α correlations in the t+t reaction
proved by the neutron energy distribution of muon
catalyzed t-t fusion”, Phys. Lett. B 557, 176–183(2003).
Y. Yanagisawa, M. Notani, H. Sakurai, M. Kunibu, H.
Akiyoshi, N. Aoi, H. Baba, K. Demichi, N. Fukuda,
H. Hasegawa, Y. Higurashi, M. Ishihara, N. Iwasa,
H. Iwasaki, T. Gomi, S. Kanno, M. Kurokawa, Y.
Matsuyama, S. Michimasa, T. Minemura, Y. Mizoi,

T. Nakamura, A. Saito, M. Serata, S. Shimoura,
T. Sugimoto, E. Takeshita, S. Takeuchi, K. Ue, K.
Yamada, K. Yoneda, and T. Motobayashi: “The ﬁrst
excited state of 30 Ne studied by proton inelastic scattering in reversed kinematics”, Phys. Lett. B 566,
84–89 (2003).
K. Iida, K. Oyamatsu, and B. A. Sarhan: “Protonnucleus elastic scattering and the equation of state ofnuclear matter”, Phys. Lett. B 576, 273–280 (2003).
N. Dinh Dang and A. Arima: “Thermal quasiparticle correlations and continuum coupling in nuclei farfrom stability”, Phys. Rev. C 67, 014304-1–01430414 (2003).
H. Miyatake, H. Ueno, Y. Yamamoto, N. Aoi, K.
Asahi, E. Ideguchi, M. Ishihara, H. Izumi, T.
Kishida, T. Kubo, S. Mitsuoka, Y. Mizoi, M. Notani,
H. Ogawa, A. Ozawa, M. Sasaki, T. Shimoda,
T. Shirakura, N. Takahashi, S. Tanimoto, and K.
Yoneda: “Spin-parity assignments in 15 C∗ by a
new method: β-delayed spectroscopy for a spinpolarized nucleus”, Phys. Rev. C 67, 014306-1–
014306-9 (2003).
K. Yoneda, N. Aoi, H. Iwasaki, H. Sakurai, H. Ogawa,T. Nakamura, W.-D. Schmidt-Ott, S. Markus, M.
Notani, N. Fukuda, E. Ideguchi, T. Kishida, S.
Yamamoto, and M. Ishihara: “β-decay half-lives and
β-delayed neutron multiplicities of the neutron dripline nuclei 19 B, 22 C, and 23 N”, Phys. Rev. C 67,
014316-1–014316-7 (2003).
A. Ozawa, Y. Yamaguchi, M. Chiba, R. Kanungo,
K. Kimura, S. Momota, T. Suda, T. Suzuki, I.
Tanihata, T. Zheng, S. Watanabe, T. Yamaguchi,
and K. Yoshida: “Search for 21 B”, Phys. Rev. C 67,
014610-1–01460-5 (2003).
N. Dinh Dang, K. A. Vuong, T. Suzuki, and A. Arima:“Reply to the comment on the “authentic damping
mechanism” of the phonon damping model”, Phys.
Rev. C 67, 029802-1–029802-2 (2003).
H. Ogawa, K. Asahi, K. Sakai, T. Suzuki, H. Izumi, H.
Miyoshi, M. Nagakura, K. Yogo, A. Goto, T. Suga,
T. Honda, H. Ueno, Y. X. Watanabe, K. Yoneda, A.
Yoshimi, N. Fukuda, Y. Kobayashi, A. Yoshida, T.
Kubo, M. Ishihara, N. Imai, N. Aoi, S. Wolf-Dieter,
G. Neyens, and S. Teughels: “Electric quadrupole
moment of 17 B and anomalous E2 eﬀective charges
for neutron-rich nuclei”, Phys. Rev. C 67, 0643081–064308-9 (2003).
N. Dinh Dang and A. Arima: “Modiﬁed Hartree-FockBogoliubov theory at ﬁnite temperature”, Phys.
Rev. C 68, 014318-1–014318-18 (2003).
N. Dinh Dang and A. Arima: “Pairing eﬀect on thegiant dipole resonance width at low temperature”,
Phys. Rev. C 68, 044303-1–044303-7 (2003).
G. Watanabe and K. Iida: “Electron screening in theliquid-gas mixed phases of nuclear matter”, Phys.
Rev. C 68, 045801-1–045801-11 (2003).
T. Sugihara: “Lattice chiral symmetry with hopping

interactions”, Phys. Rev. D 68, 034502-1–034502-4(2003).
F. Schumann, F. Hammache, S. Typel, F. Uhlig, K.
Summerer, I. Bottcher, D. Cortina, A. Forester, M.
Gai, H. Geissel, U. Greife, N. Iwasa, P. Koczon, B.
Kohlmeyer, R. Kulessa, H. Kumagai, N. Kurz, M.
Menzel, T. Motobayashi, H. Oeschler, A. Ozawa, M.
Ptoskon, W. Prokopowicz, E. Schwab, P. Senger, F.
Strieder, C. Sturm, Z. Sun, G. Surowka, A. Wagner,
and W. Walus: “Coulomb dissociation of 8 B and thelow-energy cross section of the 7 Be(p,γ)8 B solarfusion reaction”, Phys. Rev. Lett. 90, 23501-1–23501-4(2003).
N. Kawamura, K. Nagamine, T. Matsuzaki, K. Ishida,
S. Nakamura, Y. Matsuda, M. Tanase, M. Kato,
H. Sugai, K. Kudo, N. Takeda, and G. H. Eaton:“Discovery of temperature-dependent phenomena of
muon-catalyzed fusion in solid deuterium and tritium mixtures”, Phys. Rev. Lett. 90, 043401-1–
043401-4 (2003).
A. A. Korsheninnikov, E. Nikolski, E. Kuzmin, A.
Ozawa, K. Morimoto, F. Tokanai, R. Kanungo, I.
Tanihata, N. Timofeyuk, M. S. Golovkov, A. S.
Fomichev, A. M. Rodin, M. L. Chelnokov, G. M.
Ter-Akopian, W. Mittig, P. Roussel-Chomaz, H.
Savajols, E. Pollacco, A. A. Ogloblin, and M. V.
Zhukov: “Expermental evidence for the existence of7
H and for a speciﬁc structure of 8 He”, Phys. Rev.
Lett. 90, 82501-1–82501-4 (2003).
A. Toyoda, K. Ishida, K. Simomura, S. Nakamura,
Y. Matsuda, W. Higemoto, T. Matsuzaki, and K.
Nagamine: “New insights in muon-catalyzed dd fusion by using ortho-para controlled solid deuterium”,
Phys. Rev. Lett. 90, 243401-1–243401-4 (2003).
H. Miyadera, K. Nagamine, K. Simomura, K.
Nishiyama, H. Tanaka, K. Fukuchi, S. Makimura,and K. Ishida: “Dai Omega, a large solid angle axial focusing superconducting surface muon channel”,
Physica B 326, 265–269 (2003).
H. Ryuto, N. Inabe, N. Fukunishi, H. Hasebe, M.
Kase, and Y. Yano: “Charge stripping scheme in the
RIKEN RI-beam factory”, Proc. 14th Symp. on Accelerator Science and Technology, (KEK), Tsukuba,
2003–11, KEK, Tsukuba, pp. 551–553 (2003).
Y. Motizuki, H. Madokoro, and T. Shimizu: “Sensitivity of core-collapse supernovae to neutrino luminosity in cases of anisotropic neutrino radiation”, Proc. 1st Yamada Symp. on Neutrinos andDark Matter in Nuclear Physics (YS1-NDM03)(Web) (http://ndm03.phys.sci.osaka-u.ac.jp/proc/
index.htm), Nara, 2003–6, edited by H. Ejiri andI. Ogawa, YS1-NDM03, pp. 281–286 (2003).
S. Ozawa and M. Hamagaki: “Preparation of boron
ﬁlms by sputtering with electron-beam-excitedplasma”, Proc. 7th Int. Symp. on Sputtering &Plasma Processes (ISSP 2003), Kanazawa, 2003–
6, edited by N. Fujiwara, ISSP 2003, Kanazawa,323

pp. 409–412 (2003).
H. Watanabe, H. Ueno, D. Kameda, W. Sato, A.
Yoshimi, H. Miyoshi, Y. Kobayashi, T. Kishida,
K. Asahi, A. Odahara, and Y. Gounou: “g factorof the high-spin isomer in 149 Dy and large oblate
deformation induced by collapse of the N = 82core”, Proc. Int. Symp. on Frontiers of Collective Motions (CM2002), (Aizu University), AizuWakamatsu, 2002–11, edited by H. Sagawa and H.
Iwasaki, World Scientiﬁc, Singapore, pp. 355–360(2003).
K. Ishida, K. Nagamine, T. Matsuzaki, and N.
Kawamura: “Highlights of muon catalyzed fusion
experiments at RIKEN-RAL”, Proc. Int. Workshop
on Exotic Atoms - Future Perspectives (EXA 2002),(Austrian Academy of Sciences), Vienna, Austria,
2002–11, Austrian Academy of Sciences Press, Vienna, pp. 175–184 (2003).
T. Izubushi: “Domain wall fermions and chiralsymmetry”, Proc. RBRC/CCAST Symp. on Spin
Physics, Lattice QCD and RHIC Physics (CCASTWL Workshop Ser., Vol. 151), (RBRC and CCAST),
Beijing, China, 2003–4, CCAST, Beijing, pp. 11–40(2003).
Y. Motizuki: “RIBF nuclear astrophysics project:toward uniﬁed understanding of the mechanisumof core-collapse supernovae and neucleosynthesis”,
Proc. Workshop on Strategy of Astrophysical Nuclear Reaction Studies, (RIKEN), Wako, 2003–3,
RIKEN, Wako, pp. 33–34 (2003).
K. Oyamatsu and K. Iida: “Saturation of nuclear matter and radii of unstable nuclei”, Prog. Theor. Phys.
109, 631–650 (2003).
K. Koori, K. Iida, and K. Sato: “Upper limit on themass of RX J1856.5-3754 as a possible quark star”,
Prog. Theor. Phys. 109, 765–780 (2003).
L. Geng, H. Toki, S. Sugimoto, and J. Meng: “Relativistic mean ﬁeld theory for deformed nuclei withpairing correlations”, Prog. Theor. Phys. 110, 921–
936 (2003).
K. Koori, K. Iida, and K. Sato: “Possible quark star
RX J1856.5-3754 and its mass”, Prog. Theor. Phys.
Suppl., No. 151, pp. 181–185 (2003).
A. Yoshida, T. Suda, T. Kubo, T. Ohtsuki, and H.
Yuki: “A test of radiation hardness of magnetic
ﬂuid”, Res. Rep. Lab. Nucl. Sci. 36, 111–114 (2003).
K. Iida: “Compact stars: from observations to dense
matter”, Soryushiron Kenkyu 106, E33–E36 (2003).
P. Bakule, Y. Matsuda, Y. Miyake, P. Strasser,
K. Shimomura, S. Makimura, and K. Nagamine:“Slow muon experiment by laser resonant ionization method at RIKEN-RAL muon facility”, Spectrochim. Acta B 58, 1019–1030 (2003).
H. Watanabe, Y. Wakabayashi, Y. Gounou, T.
Fukuchi, H. Ueno, W. Sato, A. . Yoshimi, D.
Kameda, H. Miyoshi, T. Kishida, Y. Kobayashi, T.
Morikawa, S. Motomura, O. Kashiyama, K. Saito,

324

A. Odahara, and K. Asahi: “Lifetime of a new highspin isomer in 150 Dy”, Eur. Phys. J. A 19, 163–167(2004).
Y. Motizuki and S. Kumagai: “44 Ti radioactivity inyoung supernova remnants: Cas A and SN 1987A”,
New Astron. Rev. 48, 69–73 (2004).
M. Sekimoto, J. Chiba, H. Funahashi, H. Hamagaki,
M. Ieiri, M. Ishino, M. Kitaguchi, S. Mihara, T.
Miyashita, T. Murakami, R. Mutou, M. Naruki,
M. Nomachi, K. Ozawa, F. Sakuma, O. Sasaki, T.
Tabaru, K. Tanaka, S. Yamada, S. Yokkaichi, Y.
Yoshimura, and H. Enyo: “Spectrometer for measurements of φ mesons in nuclear matter produced
through 12-GeV p+A reactions”, Nucl. Instrum.
Methods Phys. Res. A 516, 390–405 (2004).
T. Sugihara: “Chiral symmetry on a lattice with hopping interactions”, Nucl. Phys. B (Proc. Suppl.)
129-130C, 510–512 (2004).
S. Sugimoto, H. Toki, and K. Ikeda: “Relativistic
mean ﬁeld theory with the pion for ﬁnite nuclei”,
Nuclear Theory ’22: Proc. 22nd Int. Workshop on
Nuclear Theory, (The Institute of Nuclear Researchand Nuclear Energy of the Bulgarian Academy of
Sciences), Rila Mountains, Bulgaria, 2003–6, edited
by V. Nikolaev, Heron Press, Soﬁa, pp. 33–38 (2004).
K. Yamada, T. Motobayashi, H. Ryuto, N. Aoi, Z.
Fulop, T. Gomi, Y. Higurashi, N. Imai, N. Iwasa,
H. Iwasaki, Y. Iwata, H. Kobayashi, M. Kurokawa,
Z. Liu, T. Minemura, S. Ozawa, H. Sakurai, M.
Serata, S. Shimoura, S. Takeuchi, T. Teranishi, Y.
Yanagisawa, K. Yoshida, and M. Ishihara: “E1strength of the subthreshold 3/2+ state in 15 O studied by Coulomb excitation”, Phys. Lett. B 579, 265–
270 (2004).
Y. Ogawa, H. Toki, S. Tamenaga, H. Shen, A. Hosaka,
S. Sugimoto, and K. Ikeda: “Chiral sigma modelwith pion mean ﬁeld in ﬁnite nuclei”, Prog. Theor.
Phys. 111, 75–92 (2004).

3. Atomic and solid-state physics
Y. Yoshida, Y. Kobayashi, F. Ambe, E. Yagi, X. Diao,
J. Nakamura, H. Haesslein, A. Feinauer, T. Grund,
A. Roeck, and A. Seeger: “Direct observation of selfinterstitial motion in pure iron by 56Fe(d,p)57Fe inbeam Mössbauer spectroscopy”, Defect Diﬀus. Forum 194/199, 29–34 (2001).
A. Igarashi, M. P. Faifman, and I. Shimamura: “Nonadiabatically coupled hyperspherical equations applied to the collisional spin ﬂip of muonic hydrogen”,
Hyperﬁne Interact. 138, 77–83 (2001).
F. Saito, Y. Nagashima, L. Wei, Y. Itoh, A. Goto,
and T. Hyodo: “A high-eﬃciency positron moderator using electro-polished tungsten meshes”, Appl.
Surf. Sci. 194, 13–15 (2002).
Y. Yoshida, Y. Kobayashi, A. Yoshida, X. Diao, S.
Ogawa, K. Hayakawa, K. Yukihira, S. Fumio, andF. Ambe: “In-beam Mössbauer spectroscopy after GeV-ion implantation at an on-line projectilefragmentats separator”, Hyperﬁne Interact. 141/
142, 157–162 (2002).
K. Kimura, S. Sharma, and A. Popov: “Fast electronhole plasma luminescence from track-cores in heavyion irradiated wide-band-gap crystals”, Nucl. Instrum. Methods Phys. Res. B 191, 48–53 (2002).
Y. Nakai: “Production of heavy fragment ions incollisions of C60 with fast ions”, Proc. 22nd Int.
Conf. on Photonic, Electronic and Atomic Collisions(ICPEAC 2001), Santa Fe, USA, 2001–7, Rinton
Press, Princeton, pp. 665–674 (2002).
D. P. van der Werf, M. Amoretti, G. Bonomi, A.
Bouchta, P. D. Bowe, C. Carraro, C. L. Cesar, M.
Charlton, M. Doser, V. Filippini, A. Fontana, M. C.
Fujiwara, R. Funakoshi, P. Genova, J. S. Hangst,
R. S. Hayano, L. V. Jorgensen, V. Lagomarsino,
R. Landua, E. Lodi-Rizzini, M. Macri, N. Madsen,
G. Manuzio, P. Montagna, H. Pruys, C. Regenfus,
A. Rotondi, G. Testera, and A. Variola: “Transfer,
stacking and compression of positron plasmas under UHV conditions”, AIP Conf. Proc. 692, 172–177(2003).
A. Igarashi, M. Kimura, I. Shimamura, and N.
Toshima: “Positron annihilation and positronium
formation: a uniﬁed theory in terms of a complex
potential”, Butsuri 58, 528–532 (2003).
I. Shimamura:“Hyperspherical coupled-channel
method for Coulomb three-body continuum processes”, Frontiers in atomic, molecular and optical physics, edited by S. P. Sen Gupta, S. S.
Bhattacharyya, and S. C. Mukherjee, Allied Publishers PVT., New Delhi, pp. 141–170 (2003).
E. Yagi: “The state of hydrogen in Nb-based Nb-Mo
alloys analyzed by the channelling method”, ISIJ
Int. 43, 505–513 (2003).
M. Wada, Y. Ishida, T. Nakamura, Y. Yamazaki,
T. Kambara, H. Oyama, Y. Kanai, T. Kojima,
Y. Nakai, N. Oshima, A. Yoshida, T. Kubo, Y.
Matsuo, Y. Fukuyama, K. Okada, T. Sonoda, S.
Ohtani, K. Noda, H. Kawakami, and I. Katayama:“Slow RI-beams from projectile fragment separators”, Nucl. Instrum. Methods Phys. Res. B 204,
570–581 (2003).
N. Oshima, T. Kojima, M. Niigaki, A. Mohri, K.
Komaki, Y. Iwai, and Y. Yamazaki: “Development of a cold HCI source for ultra-slow collisions”,
Nucl. Instrum. Methods Phys. Res. B 205, 178–182(2003).
Y. Iwai, Y. Kanai, Y. Nakai, T. Ikeda, H. Oyama, K.
Ando, H. Masuda, K. Nishio, M. Nakao, H. Torii, K.
Komaki, and Y. Yamazaki: “High-resolution soft Xray spectroscopy of slow highly charged ions transmitted through a microcapillary target”, Nucl. Instrum. Methods Phys. Res. B 205, 762–766 (2003).
Y. Nakai, T. Ikeda, Y. Kanai, T. Kambara, N.

Fukunishi, T. Azuma, K. Komaki, Y. Takabayashi,
and Y. Yamazaki: “Resonant coherent excitation of
94 MeV/u Ar17+ ions channeling through a Si crystal”, Nucl. Instrum. Methods Phys. Res. B 205,
784–788 (2003).
A. Hida, A. Iwase, Y. Mera, T. Kambara, and K.
Maeda: “STM study of ion tracks created in GaAs
by GeV Xe ion irradiation”, Nucl. Instrum. Methods
Phys. Res. B 209, 140–144 (2003).
K. Kimura: “Ultra-fast luminescence in heavy-ion
track-cores in insulators: Electron-hole plasma”,
Nucl. Instrum. Methods Phys. Res. B 212, 123–134(2003).
M. Koshimizu, K. Asai, and K. Kimura: “Timeresolved luminescence spectra of electron-hole
plasma in ion-irradiated CdS”, Nucl. Instrum. Methods Phys. Res. B 212, 376–380 (2003).
N. Yamanaka, Y. Kino, Y. Takano, H. Kudo, and A.
Ichimura: “Enhancement of direct positron annihilation due to temporal capture by an atom”, Phys.
Rev. A 67, 052712-1–052712-4 (2003).
A. Igarashi, M. Kimura, I. Shimamura, and N.
Toshima: “Inseparable positron annihilation andpositronium formation on positron-atom collisions:
Description in terms of an absorption potential”,
Phys. Rev. A 68, 042716-1–042716-8 (2003).
N. Yamanaka and Y. Kino:“Time-dependent
coupled-channel calculation for elastic scatterringof positrons by hydrogen atoms and helium ions”,
Phys. Rev. A 68, 052715-1–052715-6 (2003).
S. Ohira, K. Awaga, W. Fujita, I. Watanabe, and K.
Nagamine: “µSR study on a metal complex having
a ferromagnetic linear chain p-NPNN·Cu(hfac)2 ”,
Physica B 326, 568–571 (2003).
M. Wada and Y. Yamazaki: “Technical developments
toward antiprotonic atoms for nuclear structurestudieds of radioactive nuclei”, Nucl. Instrum. Methods Phys. Res. B 214, 196–200 (2004).

4.

Radiochemistry, radiation chemistry, and radiation biology

T. Ozaki, S. Ambe, T. Abe, and A. J. Francis: “Adsorption of radionuclides on silica and their uptake by rice plants from silica-multitracer solutions”,
Biol. Trace Elem. Res. 90, 273–281 (2002).
K. Igarashi, Y. Nakanishi, R. Hirunuma, S. Enomoto,and S. Kimuta: “Inﬂuence of NaFeEDTA and ferrous sulfate on the absorption of trace elements ineverted intestinal segments of rats”, Biomed. Res.
Trace Elem. 13, 322–323 (2002).
T. Matsuyama, T. Abe, S. Yoshida, K. Koike, and T.
Ebisuzaki: “A DNA polymorphism detection system by simulation using the Arabidopsis genome
sequences -a virtual imaging restriction landmark
genomic scanning”, DNA Polymorphism 10, 60–63(2002).

325

M. Hirate, A. Takeda, H. Tamano, S. Enomoto, andN. Oku: “Distribution of trace elements in the brain
of EL (epilepsy) mice”, Epilepsy Res. 51, 109–116(2002).
Y. Kobayashi, Y. Yoshida, K. M. Kubo, Y. Yamada,
A. Yoshida, H. Ogawa, H. Ueno, and K. Asahi: “Inbeam Mössbauer studies of 57 Mn using a secondary57
Mn beam and ion implantation”, Eur. Phys. J. A
13, 243–246 (2002).
S. Goto, S. Morimoto, T. Kurobe, M. Izumi, N.
Fukunishi, M. Watanabe, and F. Yatagai: “Delayed
cell-cycle arrest following heavy-ion exposure”, Int.
Congr. Ser. 1236, 317–318 (2002).
T. Abe, T. Matsuyama, S. Sekido, I. Yamaguchi, S.
Yoshida, and T. Kameya: “Chlorophyll-deﬁcientmutants of rice demonstrated the deletion of a DNA
fragment by heavy-ion irradiation”, J. Radiat. Res.
43, Suppl., S157–S161 (2002).
S. Morimoto, M. Honma, and F. Yatagai: “Sensitive
detection of LOH events in a human cell line after
C-ion beam exposure”, J. Radiat. Res. 43, Suppl.,
S163–S167 (2002).
Y. Yabushita, Y. Kanayama, T. Tarohda, R. Amano,
and S. Enomoto: “Multitracer screening for in vivo
element-element interrelations - Part I: Uptake of54
Mn, 46 Sc, 59 Fe, 58 Co, 65 Zn, 75 Se, 83 Rb, 85 Sr and
88
Zr by brain and other organs of mice bred under
Mn-deﬁcient, -adequate and -excessive diets”, J. Radioanal. Nucl. Chem. 253, 93–99 (2002).
S. Enomoto and R. Hirunuma: “Multitracer technology in biology”, Perspectives in Heavy Ion Physics:
Proc. 4th Italy-Japan Symp., Wako, Tokyo, 2001–9,
edited by K. Yoshida, S. Kubono, I. Tanihata, and
C. Signorini, World Scientiﬁc, Singapore, pp. 468–
479 (2002).
Y. Kobayashi, K. M. Kubo, Y. Yamada, T. Saito,
K. Katsumata, J. Miyazaki, H. Ueno, H. Ogawa,
W. Sato, K. Yoneda, H. Watanabe, H. Miyoshi, D.
Kameda, and K. Asahi: “Study on valence statesof 57 Fe arising from 57 Mn implanted into KMnO4 ”,
Proc. Specialist Research Meet. on New Developments in Solid State Physics with Probes of Radiations and Nuclei, (Research Reactor Institute, Kyoto
University), Kumatori, 2001–11, edited by S. Nasu,
Y. Maeda, and Y. Kawase, Research Reactor Institute, Kyoto University, Osaka, pp. 20–23 (2002).
K. Igarashi, Y. Nakanishi, R. Hirunuma, S. Enomoto,and S. Kimura: “Inﬂuence of NaFeEDTA and ferrous sulfate on the absorption of trace elements inrats everted intestinal segments”, Proc. Trace Nutr.
Res. 19, 51–53 (2002).
S. Morimoto, S. Goto, T. Kato, M. Izumi, M.
Komiyama, N. Fukunishi, M. Honma, F. Hanaoka,
and F. Yatagai: “Cellular responses to low doseheavy-ion exposure in human cells”, Radiat. Prot.
Dosim. 99, 253–254 (2002).
S. Goto, M. Watanabe, and F. Yatagai: “Delayed cell

326

cycle progression in human lymphoblastoid cells after exposure to high-LET radiation correlates withextremely localized DNA damage”, Radiat. Res.
158, 678–686 (2002).
T. Matsuyama: “RLGS proﬁling by computer simulation”, Regulation of Plant Growth and Development
37, 192–197 (2002).
T. Ozaki, S. Ambe, T. Abe, and F. J. Arokiasamy:“Eﬀect of humic acid on the bioavailability of radionuclides to rice plants”, Anal. Bioanal. Chem.
375, 505–510 (2003).
S. Enomoto, H. Haba, R. Hirunuma, K. Igarashi, A.
Nakayama, and S. Motomura: “Evolution of RI production technology for bio-trace elemental researchusing RIKEN accelerator research facility”, Biomed.
Res. Trace Elem. 14, 359–361 (2003).
K. Igarashi, R. Hirunuma, H. Haba, S. Enomoto, andS. Kimura: “Eﬀects of carnosine for the absorptionof iron and various trace elements in rats”, Biomed.
Res. Trace Elem. 14, 379–380 (2003).
T. Matsuyama, H. Saito, T. Abe, S. Yoshida, H. Kato,
K. Koike, and T. Ebisuzaki: “Arabidopsis genome
analysis by the virtual RLGS system”, DNA Polymorphism, Vol.11, edited by Japanese Society for
DNA Polymorphism Research, Toyo-shoten, Tokyo,
pp. 65–67 (2003).
F. Ambe, S. Ambe, and S. Enomoto: “Chapter 11:
Tracer technique”, Handbook of Nuclear Chemistry,
Vol. 3: Chemical Application of Nuclear Reactions
and Radiations, edited by A. Vertes, S. Nagy, and Z.
Klencsar, Kluwer Academic Publishers, Dordrecht,
pp. 443–474 (2003).
T. Abe, H. Saito, and Y. Miyazawa: “Plant breeding by heavy-ion beam irradiation”, Isotope News,No. 595, pp. 9–12 (2003).
T. Takanami, Y. Zhang, H. Aoki, T. Abe, S. Yoshida,
H. Takahashi, S. Horiuchi, and A. Higashitani: “Efﬁcient repair of DNA damage induced by heavy ion
particles in meiotic prophase I nuclei of Caenorhabditis elegans”, J. Radiat. Res. 44, 271–276 (2003).
K. Matsumoto, I. Ui, R. Hirunuma, S. Enomoto, and
K. Endo: “In vivo assessment of dynamics of various
elements in living rat by using a multitracer”, J.
Radioanal. Nucl. Chem. 255, 143–147 (2003).
Y. Kobayashi, K. M. Kubo, Y. Yamada, T. Saito, H.
Ueno, H. Ogawa, W. Sato, K. Yoneda, H. Watanabe,
N. Imai, H. Miyoshi, and K. Asahi: “Valence statesof 57 Fe decayed from 57 Mn implanted into KMnO4 ”,
J. Radioanal. Nucl. Chem. 255, 403–406 (2003).
K. Matsumoto, H. Nagashima, N. Sotogaku, R.
Hirunuma, S. Enomoto, and K. Endo: “Aﬃnity ofvarious bio-trace elements to lipid membrane: Invivo and in vitro study using multitracer”, J. Radioanal. Nucl. Chem. 255, 489–493 (2003).
T. Saito, Y. Kobayashi, K. M. Kubo, and Y. Yamada:“Development and application of parallel plateavalanche counter for in-beam Mössbauer spec-

troscopy”, J. Radioanal. Nucl. Chem. 255, 519–522(2003).
Y. Yabushita, Y. Kanayama, T. Tarohda, S. Enomoto,and R. Amano: “Multitracer screening for in vivo
element-element interrelations Part II: Uptake of
65
Zn, 46 Sc, 58 Co, 54 Mn, 75 Se, 83 Rb, 85 Sr and 88 Zr
by brain and other organs of mice bred under Zndeﬁcient, -adequate and -excessive diets”, J. Radioanal. Nucl. Chem. 256, 481–488 (2003).
T. Ozaki, S. Ambe, T. Abe, and F. J. Arokiasamy:“Uptake of short half-life radionuclides, 28 Mg, 43 K
and 47 Ca, in carrot studied by the multitracer technique: Feasibility of utilization of the radionuclides
in environmental research”, J. Radioanal. Nucl.
Chem. 258, 89–92 (2003).
S. Yoshida, T. Abe, and Y. Yano: “Developmentof plant mutagenesis using ion beams irradiation”,
JAERI-Conf, No. 2003-003, pp. 26–28 (2003).
T. Soshi, S. Enomoto, and I. Yamaguchi: “Eﬀect
of microorganisms on the uptake of radionuclides
by plant, application of the plant-microorganisms
complex system to the phytoremediation”, JAERIConf., No. 2003-010, pp. 272–276 (2003).
R. Hirunuma and S. Enomoto: “Application of themultitracer technique: Transport of various elements in the pregnant rats and the fetus”, JAERIConf., No. 2003-010, pp. 326–331 (2003).
H. Haba, R. Hirunuma, and S. Enomoto: “Development of a gas-jet coupled multitarget system for multitracer production”, JAERI-Conf., No. 2003-010,
pp. 332–334 (2003).
H. Kagami and T. Abe: “Training of the new UNSHUU mandarin orange by heavy ion irradiation”,
Kongetsu no Nougyou 47, No. 10, pp. 52–55 (2003).
S. Yoshida, T. Abe, and N. Fukunishi: “Plant reseachat RIKEN Ring Cyclotron facilities”, Korekarano
Daigaku to Kenkyu Shisetsu Dai2hen: Seimeikagakuhen, Research Institute of Educational Facilities and The Science News Ltd., Tokyo, pp. 7-1–7-11(2003).
T. Morishita, H. Yamaguchi, K. Degi, N. Shikazono,
Y. Hase, A. Tanaka, and T. Abe: “Dose response
and mutation induction by ion beam irradiation inbuckwheat”, Nucl. Instrum. Methods Phys. Res. B
206, 565–569 (2003).
T. Matsuyama, M. Kimura, K. Koike, T. Abe, T.
Nakano, T. Asami, T. Ebisuzaki, W. A. Held,
S. Yoshida, and H. Nagase: “Global methylation
screening in the Arabidopsis thaliana and Mus musculus genome: Applications of virtual image restriction landmark genomic scanning (Vi-RLGS)”, Nucleic Acids Res. 31, 4490–4496 (2003).
T. Abe, Y. Miyazawa, H. Saito, S. Yoshida, N.
Fukunishi, H. Ryuto, and Y. Yano: “Utilizationof heavy ion beam as a mutagen in plants”, Proc.
14th Symp. on Accelerator Science and Technology,(KEK), Tsukuba, 2003–11, KEK, Tsukuba, pp. 578–

580 (2003).
M. Saitoh, H. Komori, H. Sakamoto, M. Hatashita, K.
Takagi, T. Abe, and S. Yoshida: “Mutation breeding
using ion beams”, Proc. 2nd 21Seiki Rengou Symp.:
Kagakugijutsu to Ningen, Tokyo, 2003–11, Ionics,
Tokyo, pp. 77–78 (2003).
H. Saito, Y. Miyazawa, Y. Yamamoto, K. Suzuki,
T. Abe, N. Fukunishi, H. Ryuto, Y. Yano, andS. Yoshida: “Mutants induced by heavy-ion beamirradiation”, Proc. 2nd 21Seiki Rengou Symp.:
Kagakugijutsu to Ningen, Tokyo, 2003–11, Ionics,
Tokyo, pp. 79–80 (2003).
T. Abe, Y. Miyazawa, K. Sakino, J. M. Wang, andS. Yoshida: “Heavy-ion beam mutagenesis for herbicide resistant plants”, Proc. 30th Ann. Conf.
on Plant Growth Regulation Soc. of America held
jointly with the Japanese Soc. for Chemical Regulation Plants, Vancouver, Canada, 2003–8, PGRSA,
LaGrange, p. 185 (2003).
S. Enomoto: “The multitarcer technology in bio-traceelements research”, Proc. Int. Symp. on Bio-Trace
Elements 2002, edited by S. Enomoto and Y. Seko,
RIKEN, Wako, pp. 27–31 (2003).
T. Nabekura, T. Minami, R. Hirunuma, S. Enomoto,and Y. Ito: “Expression of metallothionein in
cataractous rat lens”, Proc. Int. Symp. on Bio-Trace
Elements 2002, edited by S. Enomoto and Y. Seko,
RIKEN, Wako, pp. 71–73 (2003).
T. Ohyama, M. Koike, T. Ogi, Y. Kawamoto, H.
Maetsu, H. Suganuma, M. Noguchi, K. Ishikawa, R.
Hirunuma, S. Enomoto, and M. Yanaga: “Distribution of trace elements among subcellular fractions
in livers of Zn-deﬁcient mice”, Proc. Int. Symp. on
Bio-Trace Elements 2002, edited by S. Enomoto and
Y. Seko, RIKEN, Wako, pp. 80–82 (2003).
T. Ogi, Y. Kawamoto, H. Maetsu, M. Koike, T.
Ohyama, S. Enomoto, M. Noguchi, H. Suganuma,
and M. Yanaga: “Eﬀects of zinc content in a dieton concentrations of trace elements in organs andtissues of mice”, Proc. Int. Symp. on Bio-Trace Elements 2002, edited by S. Enomoto and Y. Seko,
RIKEN, Wako, pp. 83–85 (2003).
K. Igarashi, Y. Nakanishi, R. Hirunuma, S. Enomoto,and S. Kimura: “Biological interaction of various
trace elements and NaFeEDTA as a food fortiﬁcant”,
Proc. Int. Symp. on Bio-Trace Elements 2002, edited
by S. Enomoto and Y. Seko, RIKEN, Wako, pp. 86–
90 (2003).
H. Yasui, T. Takino, J. Fugono, A. Nakayama, R.
Hirunuma, S. Enomoto, and H. Sakurai: “Eﬀect of
vanadium treatment on tissue distribution of biotrace elements in normal and streptozotocin-induced
diabetic rats”, Proc. Int. Symp. on Bio-Trace Elements 2002, edited by S. Enomoto and Y. Seko,
RIKEN, Wako, pp. 134–136 (2003).
T. Soshi, S. Enomoto, and I. Yamaguchi: “Eﬀect
of microorganisms on the uptake of radionuclides327

by plant”, Proc. Int. Symp. on Bio-Trace Elements
2002, edited by S. Enomoto and Y. Seko, RIKEN,
Wako, pp. 143–146 (2003).
A. Nakayama, H. Yasui, H. Sakurai, R. Hirunuma, and
S. Enomoto: “Distribution of biotrace elements inpartially hepatectomized rats”, Proc. Int. Symp. on
Bio-Trace Elements 2002, edited by S. Enomoto and
Y. Seko, RIKEN, Wako, pp. 159–161 (2003).
Y. Kobayashi, K. Kubo, Y. Yamada, T. Saito, W. Sato,
H. Ueno, J. Murata, H. Watanabe, D. Kameda,
H. Miyoshi, and K. Asahi: “Chemical states of
Fe implanted into graphite”, Proc. Specialist Research Meet. on New Developments in Solid State
Physics with Probes of Radiations and Nuclei (IV),(Research Reactor Institute, Kyoto University),
Kumatori-cho, Osaka Pref., 2002–12, edited by S.
Nasu, Y. Maeda, and Y. Kawase, Research Reactor
Institute, Kyoto University, Kumatori-cho, Osaka
Pref., pp. 18–21 (2003).
T. Saito, Y. Kobayashi, and Y. Yamada: “Emission
Mössbauer spectroscopic studies of absorbed 57 Co
atoms on graphite”, Proc. Specialist Research Meet.
on New Developments in Solid State Physics with
Probes of Radiations and Nuclei (IV), (Research Reactor Institute, Kyoto University), Kumatori-cho,Osaka Pref., 2002–12, edited by S. Nasu, Y. Maeda,
and Y. Kawase, Research Reactor Institute, Kyoto
University, Kumatori-cho, Osaka Pref., pp. 22–25(2003).
H. Yasui, Y. Adachi, J. Fugono, H. Haba, A.
Nakayama, R. Hirunuma, S. Enomoto, and H.
Sakurai: “Pharmacokinetic study on gastrointestinal absorption and disposition in the blood of48
vanadium and 65 zinc in healthy rats using radiotracer method”, Proc. Trace Nutr. Res. 20, 5–8(2003).
K. Igarashi, Y. Nakanishi, R. Hirunuma, S. Enomoto,and S. Kimura: “Eﬃcacy of NaFeEDTA for improving iron deﬁciency”, Proc. Trace Nutr. Res. 20, 109–
112 (2003).
T. Abe: “Mutation breeding using heavy-ion irradiation”, Radiat. Ind., No. 99, pp. 17–22 (2003).
H. Haba, K. Igarashi, R. Hirunuma, and S. Enomoto:“Multitracer technology and prospects of multitracer studies on the RIKEN RIBF project”, Radiochemistry News 8, 9–13 (2003).
S. Ambe, D. Abe, T. Ozaki, and F. Ambe: “Multitracer studies on the permeation of rare earth elements through a supported liquid membrane containing 2-ethylhexyl phosphonic acid-2-ethylhexyl
ester (EHEHPA)”, Radiochim. Acta 91, 217–221(2003).
S. Enomoto: “Developments of the multitracer technology as a simultaneous multi-elemental analysis
and its evolution in RI-beam factory project”, Radioisotopes 52, 631–647 (2003).
T. Nabekura, T. Minami, R. Hirunuma, S. Enomoto,328

M. Tomohiro, Y. Ito, and S. Kitagawa: “Transportof trace elements in lenses of normal and hereditary cataract UPL rats”, Toxicology 191, 227–232(2003).

5. Material Analysis
Y. Yoshida, Y. Kobayashi, K. Hayakawa, K. Yukihira,F. Shimura, A. Yoshida, X. Diao, H. Ogawa, Y.
Yano, and F. Ambe: “In-beam Mössbauer study ofinterstitial and substitutional 57 Mn/57 Fe jumps inSi”, Defect Diﬀus. Forum 194/199, 611–616 (2001).
M. Hase, K. Ishioka, K. Ushida, and M. Kitajima:“Dephasing of coherent THz phonons in bismuth
studied by femtosecond pump-probe technique”,
Appl. Surf. Sci. 197/198, 710–714 (2002).
K. Ishioka, M. Hase, K. Ushida, and M. Kitajima:“Phonon dynamics in ion-irradiated graphite and
GaAs”, Appl. Surf. Sci. 197/198, 726–729 (2002).
K. Ishioka, M. Hase, K. Ushida, and M. Kitajima:“Coherent acoustic phonon-defect scattering ingraphite”, Physica B 316/317, 296–299 (2002).
K. Maeda, K. Hasegawa, H. Hamanaka, and M.
Maeda: “Particle induced X-ray emission (PIXE)
analysis using position-sensitive crystal spectrometers: application to chemical state analysis in air”,
Adv. X-Ray Chem. Anal. Jpn. 34, 89–113 (2003).
M. Hase, K. Ishioka, M. Kitajima, and K. Ushida:“Ultrafast carrier and plasmon-phonon dynamics in
ion-irradiated n-GaAs”, Appl. Phys. Lett. 82, 3668–
3670 (2003).
K. Ishioka, M. Hase, M. Kitajima, and K. Ushida:“Coherent phonons in semimetals and semiconductors: Eﬀects of irradiation-induced defects on relaxation dynamics”, J. Surf. Sci. Soc. Jpn. 24, 288–294(2003).
M. Kitajima, M. Hase, K. Ishioka, and K. Ushida:“Application of time-domain vibrational spectroscopy to the study of defects in ion-implantedmaterials”, Nucl. Instrum. Methods Phys. Res. B
206, 99–102 (2003).
K. Hasegawa, K. Maeda, and H. Hamanaka: “A
stacked detector system for rapid high-resolution
PIXE analysis by a crystal specteometer”, Trans.
Soc. Instrum. Control Eng. 39, 11–17 (2003).

6. RIKEN-BNL Collaboration
S. Soﬀ, S. A. Bass, and A. Dumitru: “Pion interferometry at RHIC: Probing a thermalized quark-gluon
plasma?”, Phys. Rev. Lett. 86, 3981–3984 (2001).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En’yo,
Y. Goto, M. G. Perdekamp, N. Hayashi, T. Ichihara,
K. Imai, M. Ishihara, B. V. Jacak, K. Kurita,
Z. Li, Y. Mao, J. Murata, N. Saito, T. Sakuma,
H. D. Sato, T. Shibata, M. Sugioka, A. Taketani,
E. Taniguchi, J. Tojo, H. Torii, Y. Watanabe, S.

Yokkaichi, and PHENIX Collaboration: “Measurement of the midrapidity transverse energy distri√bution from sN N = 130 GeV Au+Au collisions
at RHIC”, Phys. Rev. Lett. 87, 052301-1–0523016 (2001).
V. W. Hughes, P. M. Gross, D. Kawall, W. Liu, K.
Jungmann, and G. zu Putlitz: “Test of CPT and
Lorentz invariance from muonium spectroscopy”,
Phys. Rev. Lett. 87, 111804-1–111804-4 (2001).
Y. Goto:“First polarized proton collisions at
PHENIX”, Acta Phys. Pol. B B33, 3767–3771(2002).
L. V. Bravina, E. E. Zabrodin, S. A. Bass, A. Faessler,
C. Fuchs, M. I. Gorenstein, W. Greiner, S. Soﬀ, H.
Stocker, and H. Weber: “Chemical freeze-out parameters at RHIC from microscopic model calculation”, Nucl. Phys. A 698, 383c–386c (2002).
M. Stratmann and W. Vogelsang: “Partons and QCD
in high-energy polarized pp collisions”, Nucl. Phys.
B (Proc. Suppl.) 105, 134–139 (2002).
K. Kurita: “Proton-carbon CNI polarimeter for
RHIC”, Nucl. Phys. B (Proc. Suppl.) 105, 164–167(2002).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En’yo,
Y. Goto, M. G. Perdekamp, N. Hayashi, T. Ichihara,
K. Imai, M. Ishihara, B. V. Jacak, K. Kurita, Z. Li,
Y. Mao, J. Murata, N. Saito, T. Sakuma, H. D. Sato,T. Shibata, M. Sugioka, A. Taketani, E. Taniguchi,
J. Tojo, H. Torii, Y. Watanabe, S. Yokkaichi, and
PHENIX Collaboration: “Event-by-event ﬂuctua√
tions in mean pT and mean eT in sN N = 130 GeV
Au+Au collisions”, Phys. Rev. C 66, 024901-1–
024901-10 (2002).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En’yo,
Y. Goto, M. G. Perdekamp, N. Hayashi, T. Ichihara,
K. Imai, M. Ishihara, B. V. Jacak, K. Kurita, Z. Li,
Y. Mao, J. Murata, N. Saito, T. Sakuma, H. D. Sato,T. Shibata, M. Sugioka, A. Taketani, E. Taniguchi,
J. Tojo, H. Torii, Y. Watanabe, S. Yokkaichi, and
PHENIX Collaboration: “Transverse-mass dependence of two-pion correlations in Au+Au collisions√
at sN N = 130 GeV”, Phys. Rev. Lett. 88, 1923021–192302-6 (2002).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En’yo,
Y. Goto, M. G. Perdekamp, N. Hayashi, T. Ichihara,
K. Imai, M. Ishihara, B. V. Jacak, K. Kurita, Z. Li,
Y. Mao, J. Murata, N. Saito, T. Sakuma, H. D. Sato,T. Shibata, M. Sugioka, A. Taketani, E. Taniguchi,
J. Tojo, H. Torii, Y. Watanabe, S. Yokkaichi, and
PHENIX Collaboration: “Measurement of single
electrons and implications for charm production in√
Au+Au collisions at sN N = 130 GeV”, Phys. Rev.
Lett. 88, 192303-1–192303-6 (2002).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En’yo,
Y. Goto, M. G. Perdekamp, N. Hayashi, T. Ichihara,
K. Imai, M. Ishihara, B. V. Jacak, K. Kurita, Z. Li,
Y. Mao, J. Murata, N. Saito, T. Sakuma, H. D. Sato,T. Shibata, M. Sugioka, A. Taketani, E. Taniguchi,
J. Tojo, H. Torii, Y. Watanabe, S. Yokkaichi, and
PHENIX Collaboration: “Centrality dependence of√
π +/− , K +/− , p and p production from sN N =130 GeV Au+Au collisions at RHIC”, Phys. Rev.
Lett. 88, 242301-1–242301-6 (2002).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En’yo,
Y. Goto, M. G. Perdekamp, N. Hayashi, T. Ichihara,
K. Imai, M. Ishihara, B. V. Jacak, K. Kurita, Z. Li,
Y. Mao, J. Murata, N. Saito, T. Sakuma, H. D. Sato,T. Shibata, M. Sugioka, A. Taketani, E. Taniguchi,
J. Tojo, H. Torii, Y. Watanabe, S. Yokkaichi, and
PHENIX Collaboration: “Net charge ﬂuctuations in√
Au+Au interactions at sN N = 130 GeV”, Phys.
Rev. Lett. 89, 082301-1–082301-6 (2002).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En’yo,
Y. Goto, M. G. Perdekamp, N. Hayashi, T. Ichihara,
K. Imai, M. Ishihara, B. V. Jacak, K. Kurita, Z. Li,
Y. Mao, J. Murata, N. Saito, T. Sakuma, H. D. Sato,T. Shibata, M. Sugioka, A. Taketani, E. Taniguchi,
J. Tojo, H. Torii, Y. Watanabe, S. Yokkaichi, and
PHENIX Collaboration: “Measurement of Λ and Λ̄√particles in Au+Au collisions at sN N = 130 GeV”,
Phys. Rev. Lett. 89, 092302-1–092302-6 (2002).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En’yo,
Y. Goto, M. G. Perdekamp, N. Hayashi, T. Ichihara,
K. Imai, M. Ishihara, B. V. Jacak, K. Kurita, Z. Li,
Y. Mao, J. Murata, N. Saito, T. Sakuma, H. D. Sato,T. Shibata, M. Sugioka, A. Taketani, E. Taniguchi,
J. Tojo, H. Torii, Y. Watanabe, S. Yokkaichi, and
PHENIX Collaboration: “Flow measurements via
two-particle azimuthal correlations in Au+Au col√lisions at sN N = 130 GeV”, Phys. Rev. Lett. 89,
212301-1–212301-6 (2002).
K. Sudo: “D meson production in neutrino DIS as aprobe of polarized strange quark distribution”, AIP
Conf. Proc. 675, 370–374 (2003).
N. Ishii and H. Suganuma: “A remark on the large
diﬀerence between the glueball mass and Tc in
quenched QCD”, Eur. Phys. J. A 17, 77–82 (2003).
K. Sudo: “Polarized parton distribution in neutrino
induced heavy ﬂavour production”, J. Phys. G 29,
1955–1958 (2003).
D. Cortina-Gil, J. Fernandez-Vazquez, F. Attallah,
T. Baumann, J. Benlliure, M. J. G. Borge, L.
Chulkov, C. Forssen, L. M. Fraile, H. Geissel, J.
Gerl, K. Itahashi, R. Janik, B. Jonson, S. Karlsson,
H. Lenske, S. Mandal, K. Markenroth, M. Meister,M. Mocko, G. Munzenberg, T. Ohtsubo, A. Ozawa,
Y. Perfenova, V. Pribora, A. Richter, K. Riisager, R.
Schneider, H. Scheit, G. Schreider, N. Shulgina, H.
Simon, B. Sitar, A. Stolz, P. Strmen, K. Summerer,
I. Szarka, S. Wan, H. Weick, and M. V. Zhukov:“Nuclear and Coulomb breakup of 8 B”, Nucl. Phys.
A 720, 3–19 (2003).
K. Mawatari, T. Morii, S. Oyama, and K. Sudo: “DIS+
charged current Λ+c /Λ̄c production as a probe of ∆s329

and ∆g”, Nucl. Phys. A 721, 380c–383c (2003).
T. Izubushi and RRBC Collaboration: “Lattice QCD
with dynamical domain wall quarks”, Nucl. Phys. B(Proc. Suppl.) 119, 813–815 (2003).
K. Adcox, A. V. Bazilevsky, G. M. Bunce, A.
Deshpande, H. Enyo, Y. Goto, M. G. Perdekamp,
N. Hayashi, T. Ichihara, K. Imai, M. Ishihara, B. V.
Jacak, K. Kurita, Z. Liu, Y. Mao, J. Murata, N.
Saito, T. Sakuma, H. Sato, T. Shibata, M. Sugioka,
A. Taketani, E. Taniguchi, J. Tojo, H. Torii, Y.
Watanabe, S. Yokkaichi, and PHENIX Collaboration: “Centrality dependence of the high pT charged√
hadron suppression in Au+Au collisions at sN N =130 GeV”, Phys. Lett. B 561, 82–92 (2003).
T. Hirano and Y. Nara: “Pseudorapidity dependenceof parton energy loss in relativistic heavy ion collisions”, Phys. Rev. C 68, 064902-1–064902-5 (2003).
Y. Hatta and T. Ikeda: “Universality, the QCD critical and tricritical point, and the quark number susceptibility”, Phys. Rev. D 67, 014028-1–014028-12(2003).
S. Aoki, T. Izubushi, Y. Kuramashi, and Y. Taniguchi:“Perturbative renormalization factors in domainwall QCD with improved gauge actions”, Phys. Rev.
D 67, 094502-1–094502-26 (2003).
Y. Hidaka, O. Morimatsu, T. Nishikawa, and M.
Ohtani: “Eﬀect of the pion thermal width on
the sigma spectrum”, Phys. Rev. D 68, 111901-1–
111901-5 (2003).
S. S. Adler, Y. Akiba, A. V. Bazilevsky, G. M.
Bunce, A. Deshpande, H. Enyo, D. E. Fields, B.
Fox, Y. Goto, M. G. Perdekamp, T. Ichihara, K.
Imai, M. Ishihara, O. Jinnouchi, N. Kamihara,
H. Kobayashi, K. Kurita, Y. Mao, J. Murata, H.
Onishi, K. Okada, N. Saito, H. Sato, T. Shibata,A. Taketani, K. Tanida, J. Tojo, H. Torii, Y.
Watanabe, S. Yokkaichi, and PHENIX Collaboration: “Suppressed π 0 production at large transverse√
momentum in central Au+Au collisions at sN N =200 GeV”, Phys. Rev. Lett. 91, 072301-1–072301-6(2003).
T. Hirano and Y. Nara: “Back-to-back correlations ofhigh-pT hadrons in relativistic heavy-ion collisions”,
Phys. Rev. Lett. 91, 082301-1–082301-4 (2003).
S. S. Adler, Y. Akiba, A. V. Bazilevsky, G. M. Bunce,
A. Deshpande, H. Enyo, D. E. Fields, B. Fox, Y.

330

Goto, M. G. Perdekamp, T. Ichihara, K. Imai, M.
Ishihara, O. Jinnouchi, N. Kamihara, H. Kobayashi,
K. Kurita, Y. Mao, J. Murata, H. Onishi, K.
Okada, N. Saito, H. Sato, T. Shibata, A. Taketani,
K. Tanida, J. Tojo, H. Torii, Y. Watanabe, S.
Yokkaichi, and PHENIX Collaboration: “Elliptic
ﬂow of identiﬁed Hadrons in Au+Au collisions at√
sN N = 200 GeV”, Phys. Rev. Lett. 91, 182301-1–
182301-6 (2003).
S. S. Adler, Y. Akiba, A. V. Bazilevsky, G. M. Bunce,
A. Deshpande, H. Enyo, D. E. Fields, B. Fox, Y.
Goto, M. G. Perdekamp, T. Ichihara, K. Imai, M.
Ishihara, O. Jinnouchi, N. Kamihara, H. Kobayashi,
K. Kurita, Y. Mao, J. Murata, H. Onishi, K.
Okada, N. Saito, H. Sato, T. Shibata, A. Taketani,
K. Tanida, J. Tojo, H. Torii, Y. Watanabe, S.
Yokkaichi, and PHENIX Collaboration: “Midrapidity neutral-pion
production in proton-proton col√lisions at s = 200 GeV”, Phys. Rev. Lett. 91,
241803-1–241803-6 (2003).
S. S. Adler, Y. Akiba, A. V. Bazilevsky, G. M. Bunce,
A. Deshpande, H. Enyo, D. E. Fields, B. Fox, Y.
Goto, M. G. Perdekamp, T. Ichihara, K. Imai, M.
Ishihara, O. Jinnouchi, N. Kamihara, H. Kobayashi,
K. Kurita, Y. Mao, J. Murata, H. Onishi, K.
Okada, N. Saito, H. Sato, T. Shibata, A. Taketani,
K. Tanida, J. Tojo, H. Torii, Y. Watanabe, S.
Yokkaichi, and PHENIX Collaboration: “Scaling
properties of proton and anti-proton production in√sN N = 200 GeV Au+Au collisions”, Phys. Rev.
Lett. 92, 172301-1–172301-6 (2003).
N. Ishii, H. Suganuma, and H. Matsufuru: “Thermal
width broadening of the 0++ glueball spectrum near
T c”, Prog. Theor. Phys. Suppl., No. 151, pp. 166–
170 (2003).
Y. Akiba: “Charm measurements at SPS and RHIC”,
J. Phys. G 30, S283–S293 (2004).
Z. Li, H. Enyo, Y. Goto, V. Radeka, W. Chen, D. C.
Elliott, T. Kawabata, M. Togawa, N. Saito, V.
Rykov, K. Tanida, and J. Tojo: “Novel silicon stripixel detector for PHENIX upgrade”, Nucl. Instrum.
Methods Phys. Res. A 518, 300–304 (2004).
A. Iwazaki, O. Morimatsu, T. Nishikawa, and M.
Ohtani: “Color ferromagnetism of quark matter andquantum hall states of gluons in SU(3) gauge theory”, Phys. Lett. B 579, 347–354 (2004).

Back to Contents

VII. LIST OF PREPRINTS
2003
RIKEN-AF-NP
442 R. Kanungo, M. Chiba, S. Adhikari, D. Fang, N. Iwasa, K. Kimura, K. Maeda, S. Nishimura, Y. Ogawa,T. Ohnishi, A. Ozawa, C. Samanta, T. Suda, T. Suzuki, Q. Wang, C. Wu, Y. Yamaguchi, K. Yamada, A.
Yoshida, T. Zheng, and I. Tanihata: “Two-proton halo in 17 Ne”
443 H. Madokoro, T. Shimizu, and Y. Mochizuki: “Global anisotropy vs small-scale ﬂuctuation of neutrino ﬂux
in supernova explosions”
444 A. A. Korsheninikov, E. Yu. Nikolskii, E. A. Kuzmin, A. Ozawa, K. Morimoto, F. Tokanai, R. Kanungo,
I. Tanihata, N. K. Timofeyuk, M. S. Golovkov, A. S. Fomichev, A. M. Rodin, M. L. Chelnokov, G. M.
Ter-Akopian, W. Mittig, P. Roussel-Chomaz, H. Savajols, E. Pollacco, A. A. Ogloblin, and M. V. Zhukov:“Experimental evidences for the existence of 7 H and for a speciﬁc structure of 8 He”
445 T. Yamaguchi, T. Zheng, A. Ozawa, M. Chiba, R. Kanungo, T. Kato, K. Morimoto, T. Ohnishi, T. Suda, Y.
Yamaguchi, A. Yoshida, K. Yoshida, and I. Tanihata: “Momentum distributions of 14 C and 15 C fragmentsfrom 16 C breakup”
446 Y. Yanagisawa, M. Notani, H. Sakurai, M. Kunibu, H. Akiyoshi, N. Aoi, H. Baba, H. Demichi, N. Fukuda,
K. Hasegawa, Y. Higurashi, M. Ishihara, N. Iwasa, H. Iwasaki, T. Gomi, S. Kanno, M. Kurokawa, Y. U.
Matsuyama, S. Michimasa, T. Minemura, T. Mizoi, T. Nakamura, A. Saito, M. Serata, S. Shimoura, T.
Sugimoto, E. Takeshita, S. Takeuchi, K. Ue, K. Yamada, and Motobayashi: “The ﬁrst excited state in 30 Ne
studied by proton inelastic scattering in reversed kinematics”
447 N. Iwasa, T. Motobayashi, H. Sakurai, H. Akiyoshi, Y. Ando, N. Aoi, H. Baba, N. Fukuda, Zs. Fülöp, U.
Futakami, T. Gomi, Y. Higurashi, K. Ieki, H. Iwasaki, T. Kubo, S. Kubono, H. Kinugawa, H. Kumagai,
M. Kunibu, S. Michimasa, T. Minemura, H. Murakami, K. Sagara, A. Saito, S. Shimoura, S. Takeuchi, Y.
Yanagisawa, K. Yoneda, and M. Ishihara: “In-beam γ spectroscopy of 34 Si with deuteron inelastic scttering
in reversed kinematics”
448 H. Ogawa, K. Asahi, K. Sakai, T. Suzuki, H. Izumi, H. Miyoshi, M. Nagakura, K. Yogo, A. Goto, T. Suga,
T. Honda, H. Ueno, Y. X. Watanabe, K. Yoneda, A. Yoshimi, N. Fukuda, Y. Kobayashi, A. Yoshida, T.
Kubo, M. Ishihara, N. Imai, N. Aoi, W.-D. Schmidt-Ott, G. Neyens, and S. Teughels: “Electric quadrupole
moment of 17 B and anomalous E2 eﬀective charges for neutron-rich nuclei”
449 M. Ohtani, Y. Hidaka, O. Morimatsu, and T. Nishikawa: “Eﬀect of pion thermal width on the spectral
function of sigma meson”
450 N. Dinh Dang and A. Arima: “Modiﬁed Hartree-Fock-Bogoliubov theory at ﬁnite temperature”
451 K. Yamada, T. Motobayashi, H. Akiyoshi, N. Aoi, Zs. Fülöp, T. Gomi, Y. Higurashi, N. Imai, N. Iwasa,
H. Iwasaki, Y. Iwata, H. Kobayashi, M. Kurokawa, Z. Liu, T. Minemura, S. Ozawa, H. Sakurai, M. Serata,
S. Shimoura, S. Takeuchi, T. Teranishi, Y. Yanagisawa, K. Yoshida, and M. Ishihara: “E1 strength of thesubthreshold 3/2+ state in 15 O studied by Coulomb excitation”
452 N. Imai, H. J. Ong, N. Aoi, H. Sakurai, K. Demichi, H. Kawasaki, N. Baba, Zs. Dombrádi, Z. Elekes, N.
Fukuda, Zs. Fülöp, A. Gelberg, T. Gomi, H. Hasegawa, K. Ishikawa, H. Iwasaki, E. Kaneko, S. Kanno,
T. Kishida, Y. Kondo, T. Kubo, K. Kurita, S. Michimasa, T. Minemura, M. Miura, T. Motobayashi, T.
Nakamura, M. Notani, T. K. Ohnishi, A. Saito, S. Shimoura, T. Sugimoto, M. K. Suzuki, E. Takeshita,
S. Takeuchi, M. Tamaki, K. Yoneda, H. Watanabe, and M. Ishihara: “Anomalously hindered E2 strength+
16
C”
B(E2; 2+
1 → 0 ) in
453 N. Dinh Dang and A. Arima: “Pairing eﬀect on the giant dipole resonance width at low temperature”

331454 T. Yamazaki, A. Dote, and Y. Akaishi: “Invariant-mass spectroscopy for condensed single- and double-K̄
nuclear clusters to be formed as residues in relativistic heavy-ion collisions”
455 Z. Elekes, Zs. Dombrádi, A. Krasznahorkay, H. Baba, M. Csatlós, L. Csige, N. Fukuda, Zs. Fülöp, Z.
Gácsi, J. Gulyás, N. Iwasa, H. Kinugawa, S. Kubono, M. Kurokawa, X. Liu, S. Michimasa, T. Minemura,
T. Motobayashi, A. Ozawa, A. Saito, S. Shimoura, S. Takeuchi, I. Tanihata, P. Thirolf, Y. Yanagisawa, andK. Yoshida: “Decoupling of valence neutrons from the core in 16 C”

RIKEN-AF-AC
41 T. Ohkawa, Y. Chiba, M. Wakasugi, and T. Katayama: “Development of the kicker magnet for MUSES”
42 I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, T. Katayama, H. Tsutsui, and D. Mohl: “Simulation studyof ordered ion beams”
43 R. A. Jameson, M. Okamura, and T. Katayama: “Desing of ≥ 100 MA C4+ RFQ for laser ion source”

332

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VIII. PAPERS PRESENTED AT MEETINGS
1. Accelerator
physics

development

andaccelerator

M. Komiyama, M. Kase, T. Tanabe, M. Fujimaki,
E. Ikezawa, M. Nagase, I. Yokoyama, and R. Abe:
“New control system or the RIKEN ring cyclotron
using EPICS”, 13th Symp. on Accelerator Scienceand Technology, (RCNP and ISIR, Osaka University), Suita, Oct. (2001).
M. Kobayashi, K. Ushida, Y. Aoki, M. Mori, T.
Kuribayashi, S. Kashiwagi, R. Kuroda, Y. Hama,
and M. Washio: “Development of pulse radiolysis
system with picosecond RF-gun in Waseda Universty”, 45th Symp. on Radiation Chemistry, Kasuga,
Oct. (2002).
R. Kuroda, S. Kashiwagi, A. Nagasawa, H. Kawai,
M. Washio, Y. Hama, K. Ushida, J. Urakawa, and
H. Hayano: “Development of a soft X-ray sourcefor “water-window” region based on laser Compton scattering”, 58th Ann. Meet. of Physical Soc.
of Japan, Sendai, Mar. (2003).
H. Miyoshi, J. Murata, K. Asahi, H. Ueno, A. Yoshimi,
H. Watanabe, D. Kameda, J. Kaihara, K. Shimada,
W. Sato, S. Suda, T. Ito, and Y. Kobayashi: “Development of set-up for production of low energy spinpolarized RI beam(1)”, 58th Ann. Meet. of PhysicalSoc. of Japan, Sendai, Mar. (2003).
K. Shimada, K. Asahi, T. Ito, H. Ueno, J. Kaihara,
D. Kameda, Y. Kobayashi, W. Sato, S. Suda, J.
Murata, A. Yoshimi, and H. Watanabe: “Development of set-up for production of low energy spinpolarized RI beam(2)”, 58th Ann. Meet. of PhysicalSoc. of Japan, Sendai, Mar. (2003).
H. Ueno and K. Asahi: “Production of RIBs in the
RIBF-RIPS conﬁguration”, Workshop on RI Beam
Factory and Research Plan, Wako, Mar. (2003).
M. Kidera, T. Nakagawa, S. Enomoto, K. Takahashi,
R. Hirunuma, K. Igarashi, T. Ohyama, M. Fujimaki,
E. Ikezawa, O. Kamigaito, M. Kase, and Y. Yano:“Accelerator mass spectrometry using electron cyclotron resonance ion source and heavy ion accelerator”, Dai2kai Kogata Kasokuki Kenkyukai, (KEK),
Tsukuba, July (2003).
M. Kobayashi, K. Ushida, Y. Aoki, M. Mori, T.
Kuribayashi, S. Kashiwagi, R. Kuroda, Y. Hama,
and M. Washio: “Construction of pulse radiolysis
system with a picosecond RF-gun at Waseda University”, Joint 6th ICFA Advanced & Novel Accelerators and 29th ICFA Advanced Beam Dynamics
Workshop on Laser-Beam Interactions, Oxford, UK,
July (2003).
O. Kamigaito, M. Kase, E. Ikezawa, S. Kohara, N.
Sakamoto, M. Fujimaki, T. Nakagawa, M. Kidera,
Y. Higurashi, Y. Chiba, M. Hemmi, Y. Miyazawa, T.
Chiba, T. Aihara, T. Ohki, H. Hasebe, H. Yamauchi,

A. Uchiyama, K. Oyamada, and Y. Yano: “Present
status of the RIKEN heavy-ion linac”, 28th Linear
Accelerator Meet. in Japan (LAM28), (J-PARC andothers), Tokai, July–Aug. (2003).
M. Kidera, T. Aihara, Y. Higurashi, E. Ikezawa, O.
Kamigaito, M. Kase, T. Nakagawa, N. Suzuki, andY. Yano: “Production of intense 58 Fe, 64 Ni beams
using MIVOC method and new analyzing system of
RIKEN 18 GHz ECRISS”, 10th Int. Conf. on Ion
Sources (ICIS 2003), Dubna, Russia, Sept. (2003).
T. Kikuchi, T. Katayama, K. Horioka, and M.
Nakajima: “Dynamics and space charge eﬀect during bunching processes of intense heavy-ion beam”,
2003 Fall Meet. of the Physical Soc. of Japan,
Miyazaki and Okayama, Sept. (2003).
T. Watanabe, S. Watanabe, T. Ikeda, M. Kase, Y.
Sasaki, T. Kawaguchi, and T. Katayama: “Prototype of highly-sensitive cryogenic current comparator with HTS SQUID and HTS magnetic shield”, 6th
European Conf. on Applied Superconductivity 2003
(EUCAS 2003), (Istituto Nazionale per la Fisicadella Materia (INFM)), Napoli, Italy, Sept. (2003).
F. Nagasawa, D. Ueyama, S. Kashiwagi, R. Kuroda,
M. Washio, K. Ushida, H. Hayano, and J. Urakawa:“The development of the compact soft X-ray source
using laser Compton scattering”, 46th Symp. on Radiation Chemistry, (Japanese Society of Radiation
Chemisitry), Hakone-machi, Kanagawa Pref., Sept.
(2003).
A. Goto, H. Okuno, J. Ohnishi, T. Tominaka, S.
Fujishima, K. Ikegami, N. Fukunishi, Y. Miyazawa,T. Mitsumoto, and Y. Yano: “Sector magnets for the
RIKEN superconducting ring cyclotron”, 18th Int.
Conf. on Magnet Technology (MT-18), (National Institute for Materials Science), Morioka, Oct. (2003).
T. Tanabe, T. Masuoka, K. Yoshida, K. Kumagai, M.
Komiyama, T. Emoto, and M. Kase: “Current status of the control system development at RIKEN
RI-Beam factory”, 9th Int. Conf. on Accelerator
and Large Experimental Physics Control Systems(ICALEPCS 2003), Gyeongju, Korea, Oct. (2003).
T. Kikuchi, T. Katayama, K. Horioka, and M.
Nakajima: “Beam dynamics and instability in ﬁnal beam bunching for heavy ion inertial fusion”,
14th Symp. on Accelerator Science and Technology(SAST03), (KEK), Tsukuba, Nov. (2003).
T. Tanabe, K. Yoshida, T. Masuoka, M. Kase, K.
Kumagai, and T. Emoto: “Development of RIBF
accelerator power-supply controls using distributed
object model”, 14th Symp. on Accelerator Scienceand Technology (SAST03), (KEK), Tsukuba, Nov.
(2003).
T. Watanabe, S. Watanabe, T. Ikeda, T. Katayama,
M. Kase, T. Kawaguchi, and Y. Sasaki: “Development of a highly-sensitive and nondestructive beam333

current monitor with HTS-SQUID and superconducting magnetic shield”, 14th Symp. on Accelerator Science and Technology (SAST03), (KEK),
Tsukuba, Nov. (2003).
J. Ohnishi, T. Tominaka, H. Okuno, M. Nagase, and
A. Goto: “Power supply system for the sector magnets of RIKEN superconducting ring cyclotron”,
14th Symp. on Accelerator Science and Technology(SAST03), (KEK), Tsukuba, Nov. (2003).
O. Kamigaito, M. Kase, N. Sakamoto, E. Ikezawa,
S. Kohara, M. Fujimaki, T. Nakagawa, M. Kidera,
Y. Higurashi, H. Ryuto, Y. Chiba, M. Hemmi,
Y. Miyazawa, T. Chiba, T. Aihara, T. Ohki, H.
Hasebe, H. Yamauchi, A. Uchiyama, K. Oyamada,
A. Goto, and Y. Yano: “Present status of the
RIKEN heavy-ion linac”, 14th Symp. on Accelerator Science and Technology (SAST03), (KEK),
Tsukuba, Nov. (2003).
H. Ueno, K. Asahi, and A. Yoshimi: “Beam line for the
production of spin-polarized RI beams”, Workshop
on Experimental Apparatus Dedicated to the RIBF
Project, Wako, Dec. (2003).

2. Nuclear physics and nuclear instrumentation
H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:“Shears bands in the A = 80 mass region”, 2000
Spring Meet. of the Physical Soc. of Japan, Higashi
Osaka, Mar. (2000).
H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:“Shears bands in the A = 80 mass region II”, 55th
Ann. Meet. of Physical Soc. of Japan, Niigata, Sept.
(2000).
K. Sakai, K. Asahi, H. Ogawa, A. Goto, K. Yogo,
T. Suga, H. Miyoshi, D. Kameda, M. Utsuro, K.
Okumura, M. Hino, and A. Yoshimi: “A new
method of UCN production using a spatially alternating magnetic ﬁeld with spin ﬂips”, 14th Int. Spin
Physics Symp. (SPIN 2000), Osaka, Oct. (2000).
H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:“Relativistic tilted axis cranking model and its application to the shears bands in the A = 80 region”,
Workshop on Nuclear Structure of Unstable Nuclei,(Yukawa Institute of Theoretical Physics), Kyoto,
Feb. (2001).
H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:“Relativistic Hartree-Bogoliubov study of shears
bands in the A = 80 region”, 56th Ann. Meet. of
the Physical Soc. of Japan, Hachioji, Mar. (2001).
H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:“Magnetic rotation in the A = 80 mass region”,
RIKEN Workshop: Fuanteikakubutsuri ni mukete,
Wako, Mar. (2001).
A. Saito: “Molecular states in neutron-rich nuclei
1214
Be”, Workshop on Low-Energy Radioactive Nuclei Beams, (KEK), Tsukuba, Mar. (2001).
A. Saito, S. Shimoura, S. Takeuchi, T. Motobayashi,

334

H. Ryuto, Y. Ando, N. Aoi, Z. Fulop, T. Gomi, Y.
Higurashi, M. Hirai, N. Iwasa, H. Iwasaki, Y. Iwata,
H. Kobayashi, M. Kurokawa, Z. Liu, T. Minemura,S. Ozawa, H. Sakurai, M. Serata, T. Teranishi, K.
Yamada, Y. Yanagisawa, and M. Ishihara: “Molecular states in 12 Be and 14 Be”, 3rd Int. Conf. on Exotic
Nuclei and Atomic Masses (ENAM 2001), Hameenlinna, Finland, July (2001).
R. Kanungo: “Observation of new proton and neutron magic numbers”, Int. Nuclear Physics Conf.
(INPC2001), (University of California and Lawrence
Berkeley National Laboratory), Berkeley, USA,
July–Aug. (2001).
A. Saito: “Molecular states in neutron-rich be isotopes”, Cluster Physics and Unstable Nuclei, Wako,
Aug. (2001).
J. Noaki: “Calculation of K → ππ decay amplitudes
from K → π matrix elements in quenched domainwall QCD”, LATTICE2001: 19th Int. Symp. on Lattice Field Theory, (DESY Zeuthen and HumboldtUniversitat zu Berlin), Berlin, Germany, Aug.
(2001).
T. Blum: “ from quenched lattice QCD”, 1st Joint
Meet. of the Nuclear Physicists of the American andJapanese Physical Soc. (HAW01), (APS and JPS),
Maui, USA, Oct. (2001).
Y. Nara, A. Krasnitz, and R. Venugopalan: “Gluon
productions in classical SU(3) lattice gauge theory in high energy heavy ion collisions”, 1st Joint
Meet. of the Nuclear Physicists of the American andJapanese Physical Soc. (HAW01), (APS and JPS),
Maui, USA, Oct. (2001).
R. Venugopalan: “Initial conditions in heavy ion collisions”, 1st Joint Meet. of the Nuclear Physicists of
the American and Japanese Physical Soc. (HAW01),(APS and JPS), Maui, USA, Oct. (2001).
R. Kanungo: “Modiﬁcation of shell structure in unstable nuclei”, Yukawa Int. Seminar 2001 (YKIS01):
Physics of Unstable Nuclei, (Yukawa Institute for
Theoretical Physics, Kyoto University), Kyoto, Nov.
(2001).
S. Sugimoto: “Relativistic mean ﬁeld theory with pimeson ﬁeld for ﬁnite nuclei”, Yukawa Int. Seminar 2001 (YKIS01): Physics of Unstable Nuclei,(Yukawa Institute for Theoretical Physics, Kyoto
University), Kyoto, Nov. (2001).
R. Kanungo: “Modiﬁcation of shell structure in nuclei
far from stability”, DAE-BRNS Symp. on Nuclear
Physics, (Department of Atomic Energy, Govt. ofIndia), Kolkata, India, Dec. (2001).
H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:“Relativistic Hartree-Bogoliubov study of tilted axis
rotation”, Seminar of Microscopic Description ofCollective Motion in Nuclei, (Fukuoka University),
Fukuoka, Dec. (2001).
H. Miyoshi, H. Ueno, K. Asahi, H. Ogawa, J. Murata,
K. Sakai, D. Kameda, Y. Kobayashi, W. Sato, A.

Yoshimi, H. Watanabe, K. Yoneda, N. Imai, J.
Kaihara, K. Shimada, and T. Koike: “Developmentof low energy polarized RI atomic beam”, RIKEN
Symp. on Condensed Matter Studies with Radioactive Ion Beams, Wako, Feb. (2002).
H. Watanabe: “High-spin isomer beams at RARF”,
RIKEN Symp. on Condensed Matter Studies with
Radioactive Ion Beams, Wako, Feb. (2002).
H. Ueno: “Production of radioactive ion beams in the
RIBF-RIPS conﬁguration”, RIKEN Symp. on Condensed Matter Studies with Radioactive Ion Beams,
Wako, Feb. (2002).
J. Murata: “RI beam buﬀering and the extraction towards ABS”, RIKEN Symp. on Condensed Matter
Studies with Radioactive Ion Beams, Wako, Feb.
(2002).
R. Kanungo: “Proton scattering at RIKEN RI Beam
Factory”, Workshop on Rare Isotope Physics at
Storage Rings, (GSI and RIKEN), Hirschegg, Austria, Feb. (2002).
H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:“Relativistic Hartree-Bogoliubov study of chiraldoublet bands in the odd-odd triaxial nuclei”, 57th
Ann. Meet. of Physical Soc. of Japan, Kusatsu,
Shiga Pref., Mar. (2002).
T. Motobayashi: “RI beam factory project at
RIKEN”, 14th Int. Conf. on Electromagnetic Isotope
Separators and Techniques Related to their Applications, (TRIUMF), Victoria, Canada, May (2002).
K. Asahi, H. Ueno, Y. Kobayashi, W. Sato, A.
Yoshimi, H. Miyoshi, D. Kameda, K. Shimada,H. Ogawa, K. Sakai, H. Watanabe, N. Imai, Y.
Watanabe, K. Yoneda, N. Fukuda, N. Aoi, A.
Yoshida, T. Kubo, and M. Ishihara: “Spin polarized radioacitve nuclei as probes in nuclear and condensed matter physics”, The Multilateral Symp. between the Korean Academy of Science and Technology (KAIST) and the Foreign Academies, Seoul, Korea, May (2002).
A. Yoshimi and K. Asahi: “Nuclear spin maser withan artiﬁcial feedback for fundamental physics”, Advanced study institute on Symmetries and Spin
(Praha-SPIN-2002), (Charles University), Prague,
Czech, July (2002).
T. Ichihara:“Observation of Isovector Giant
Quadrupole Resonance (IVGQR) by the Chargeexchange reaction 60 Ni(13 C,13 N)60 Co reaction at
E/A = 100 MeV”, RCNP Workshop on Nuclear
Fouce and Nuclear Phys., (RCNP and ISIR, Osaka
University), Ibaraki, July (2002).
H. Madokoro, T. Shimizu, and Y. Motizuki: “Effects of anisotropy in neutrino radiation on the supernova explosion: More complicated patterns ofanisotropy”, 7th Int. Symp. on Nuclei in the Cosmos, Fuji-Yoshida, July (2002).
S. Fujii, R. Okamoto, and K. Suzuki: “Shellmodel description of 16
Λ O with Σ degrees of free-dom”, 16th Int. Conf. on Particles and Nuclei (PaNic02), (RCNP, Osaka University), Osaka,
Sept.–Oct. (2002).
S. Sugimoto: “Surface pion condensation in ﬁnite
nuclei”, 16th Int. Conf. on Particles and Nuclei (PaNic02), (RCNP, Osaka University), Osaka,
Sept.–Oct. (2002).
S. Fujii, R. Okamoto, and K. Suzuki: “Eﬀects of theparity-mixing intershell coupling on excited states in16
Λ ”, 2002 Fall Meet. of the Physical Soc. of Japan,
Tokyo, Sept. (2002).
K. Morimoto, K. Morita, D. Kaji, Y. Zhao, H. Xu, A.
Yoneda, T. Suda, A. Yoshida, E. Ideguchi, T. Zheng,
T. Ohnishi, H. Haba, K. Katori, H. Kudo, and I.
Tanihata: “Identiﬁcation of 234 Bk and 230 Am withRIKEN GARIS”, 2002 Fall Meet. of the PhysicalSoc. of Japan, Tokyo, Sept. (2002).
H. Ueno, W. Sato, H. Watanabe, A. Yoshimi, Y.
Kobayashi, J. Murata, K. Asahi, H. Miyoshi, K.
Shimada, and T. Saito: “Development of a detector system for the g-factor mea-surement on excitedstates of unstable nuclei”, Mini-Symp. on Nuclear
Moments, Division of Nuclear Pysics 2002 Fall Meet.
of the American Physical Soc., East Lansing, USA,
Oct. (2002).
K. Asahi, H. Ogawa, H. Miyoshi, D. Kameda, K.
Sakai, H. Ueno, A. Yoshimi, H. Watanabe, W.
Sato, Y. Kobayashi, Y. Watanabe, A. Yoshida, T.
Kubo, M. Ishihara, N. Imai, N. Aoi, K. Yoneda,
and N. Fukuda: “Electromagnetic moments of lightneutron-rich nuclei”, Mini-Symp. on Nuclear Moments, Division of Nuclear Pysics 2002 Fall Meet.
of the American Physical Soc., East Lansing, USA,
Oct. (2002).
H. Watanabe, H. Ueno, W. Sato, A. Yoshimi, T.
Kishida, Y. Kobayashi, K. Asahi, D. Kameda, H.
Miyoshi, A. Odawara, and Y. Gounou: “g factor andan oblate deformation of the Ip = 49/2− high-spin
isomer in 149 Dy”, Mini-Symp. on Nuclear Moments,
Division of Nuclear Pysics 2002 Fall Meet. of theAmerican Physical Soc., East Lansing, USA, Oct.
(2002).
A. Yoshida, K. Morita, K. Morimoto, D. Kaji, T.
Kubo, Y. Takahashi, A. Ozawa, and I. Tanihata:“High-power rotating wheel targets at RIKEN”, 21stWorld Conf. the INTDS: Accelerator Target Technology for the 21th Century, Argonne, USA, Nov.
(2002).
K. Asahi, H. Ogawa, K. Sakai, H. Ueno, T. Suzuki,
H. Izumi, H. Miyoshi, N. Imai, Y. Watanabe,
K. Yoneda, M. Nagakura, K. Yogo, A. Goto, T.
Suga, T. Honda, A. Yoshimi, N. Fukuda, N. Aoi,
Y. Kobayashi, W.-D. Schmidt-Ott, G. Neyens, S.
Teughels, A. Yoshida, T. Kubo, and M. Ishihara:“Quadrupole moments of B isotopes and anomalous
E2 eﬀective charges for neutron-rich nuclei”, Int.
Symp. on Frontiers of Collective Motions (CM2002),

335

(University of Aizu), Aizu-Wakamatsu, Nov. (2002).
H. Watanabe, H. Ueno, D. Kameda, W. Sato, A.
Yoshimi, H. Miyoshi, T. Kishida, Y. Kobayashi, A.
Odawara, Y. Gounou, and K. Asahi: “g factor of thehigh-spin isomer in 149 Dy and large oblate deformation induced by collapse of the N = 82 core”, Int.
Symp. on Frontiers of Collective Motions (CM2002),(University of Aizu), Aizu-wamakatsu, Nov. (2002).
S. Sugimoto: “Relativistic mean ﬁeld theory with pion
for ﬁnite nuclei”, Int. Symp. on Physics of Unstable
Nuclei (ISPUN02), (INST, Hanoi and IOP, Hanoi),
Halong Bay, Vietnum, Nov. (2002).
K. Iida: “Phenomenological aspects of dense quark
matter”, 7th APCTP Winter School/3rd Dense
Matter School, (APCTP), Pohang, Korea, Jan.
(2003).
K. Asahi, J. Murata, H. Miyoshi, K. Shimada, H.
Ueno, W. Sato, T. Ito, and Y. Kobayashi: “Condensed matter studies using unstable nuclei asprobe”, Materials Science Symp. on Heavy Ion Science in Tandem Energy Region, (JAERI), Tokaimura, Jan. (2003).
S. Ozawa and M. Hamagaki: “Preparation of selfsupporting boron ﬁlms by electron-beam-excitedplasma”, The 20th Symposium on Plasma Processing, (Division of Plasma Electronics, JSAP), Nagaoka, Jan. (2003).
H. Koura: “Current status of theoretical study forsyntheses of superheavy nuclei in RIKEN (nuclear
structure)”, Workshop on Synthesis of Superheavy
Nuclei, Wako, Jan. (2003).
T. Matsuzaki: “Evidence for strong (n-α) correlationsin the t+t reaction proved by the neutron energy
distribution of muon catalyzed t-t fusion”, CNSRIKEN Symp. on Continuum States of Few-Body
Systems and Unstable Nuclei, and the Future, Wako,
Feb. (2003).
K. Sekiguchi, H. Sakai, H. Okamura, A. Tamii, T.
Uesaka, K. Suda, N. Sakamoto, T. Wakasa, Y.
Satou, T. Ohnishi, K. Yako, S. Sakoda, H. Kato,
Y. Maeda, J. Nishikawa, T. Saito, N. Uchigashima,
N. N. Kalantar, and K. Ermisch: “Measurementof heavy proton-proton elastic dispersion and threephysical strength in a middle energy domain”, CNSRIKEN Symp. on Continuum States of Few-Body
Systems and Unstable Nuclei, and the Future, Wako,
Feb. (2003).
K. Iida: “Quark matter and compact stars”, Grantsin-Aid for Specially Promoted Research “New Development of Black Hole Astronomy” Workshop “Neutrinos and Supernovae”, Tokyo, Feb. (2003).
H. Koura: “R-process nucleosynthesis from a viewpoint of nuclear physics -nuclear masses and nuclear ﬁssion-”, Grants-in-Aid for Specially Promoted
Research “New Development of Black Hole Astronomy” Workshop “Neutrinos and Supernovae”,
Tokyo, Feb. (2003).

336

Y. Motizuki: “Mechanism of core-collapse supernova
explosion and importance of nuclear physics”, Special lecture at Physics dept. of Kyoto University,
Kyoto, Feb. (2003).
Y. Motizuki: “Supernova explosion and synthesis ofheavy elements”, Special lecture at Physics dept. of
Kyoto University, Kyoto, Feb. (2003).
H. Koura: “Syntheses and decays of superheavy nuclei
predicted by a nuclear mass formula”, Workshop of
Advanced Science Research Center, JAERI, Nuclear
Physics and Nuclear Chemistry of Superheavy Elements, Tokai-mura, Feb. (2003).
T. Motobayashi: “Spectroscopy of unstable nuclei
around N = 8 and N = 20 by fast RI beams”,
Workshop on Inelastic Scattering with Radioactive
Nuclei, (KVI), Groningen, The Netherlands, Feb.
(2003).
T. Inamura and F. F. Karpeshin: “Bridging atomic
and nuclear states in 229 Th”, 58th Ann. Meet. ofPhysical Soc. of Japan, Sendai, Mar. (2003).
H. Koura: “Estimation of ﬁssion barriers and half-lives
in the superheavy nuclidic region”, 58th Ann. Meet.
of Physical Soc. of Japan, Sendai, Mar. (2003).
H. Madokoro, T. Shimizu, and Y. Motizuki: “Global
anisotropy vs small-scale ﬂuctuation of neutrino ﬂux
in supernova explosion”, 58th Ann. Meet. of Physical Soc. of Japan, Sendai, Mar. (2003).
K. Sekiguchi: “Heavy proton: Veriﬁcation of the 3physical strength eﬀects by proton elastic dispersion
measurement”, 58th Ann. Meet. of Physical Soc. ofJapan, Sendai, Mar. (2003).
D. Kameda, K. Asahi, H. Ueno, A. Yoshimi, H.
Miyoshi, J. Murata, H. Watanabe, W. Sato, Y.
Kobayashi, J. Kaihara, K. Shimada, S. Suda, and
T. Ito: “Measurements of Spin Polarization of 19 C
and 19 N”, 58th Ann. Meet. of Physical Soc. of Japan,
Sendai, Mar. (2003).
K. Iida, K. Oyamatsu, and B. A. Sarhan: “Proton
elastic scattering and the equation of state of nuclear
matter”, 58th Ann. Meet. of Physical Soc. of Japan,
Sendai, Mar. (2003).
K. Yamada, T. Motobayashi, N. Aoi, H. Baba, K.
Demichi, Z. Elekes, J. D. Gibelin, T. Gomi, H.
Hasegawa, N. Imai, H. Iwasaki, S. Kanno, T.
Kubo, K. Kurita, Y. Matsuyama, S. Michimasa,
T. Minemura, M. Notani, T. Onishi, H. Ong, S.
Ota, A. Ozawa, A. Saito, H. Sakurai, S. Shimoura,
E. Takeshita, S. Takeuchi, M. Tamaki, Y. Togano,
Y. Yanagisawa, K. Yoneda, and I. Tanihata: “Reduced transition probability B(E2) in proton-rich
46
Cr, 50 Fe, and 54 Ni studied by Coulomb excitation”, 58th Ann. Meet. of Physical Soc. of Japan,
Sendai, Mar. (2003).
A. Kohama: “Reﬂection of the tail region of the density distribution to the proton-nucleus elastic scattering cross section”, 58th Ann. Meet. of PhysicalSoc. of Japan, Sendai, Mar. (2003).

S. Sugimoto, H. Toki, and K. Ikeda: “Relativistic
Hartree-Fock theory with the pion for ﬁnite nuclei”,
58th Ann. Meet. of Physical Soc. of Japan, Sendai,
Mar. (2003).
S. Fujii, R. Okamoto, and K. Suzuki: “Shell structures of neutron-rich isotopes derived from modern
nuclear forces”, 58th Ann. Meet. of Physical Soc. ofJapan, Sendai, Mar. (2003).
Y. Motizuki, T. Tachibana, and S. Goriely: “Ther-process nucleosynthesis: development of reaction
network code with speciﬁc attention to nuclear
model information”, 58th Ann. Meet. of PhysicalSoc. of Japan, Sendai, Mar. (2003).
K. Asahi, H. Miyoshi, D. Kameda, K. Shimada,
H. Ueno, J. Murata, Y. Kobayashi, W. Sato, A.
Yoshimi, and H. Watanabe: “Nuclear moments
and condensed matter studies with polarized RI
beams”, Exploratory Workshop on Polarized Radioactive Beams and Polarized Targets, (Institut
de Recherches Subatomiques), Strasbourg, France,
Mar. (2003).
Y. Motizuki: “Retarded electron capture decay of 44 Ti
in plasma of supernova remnants”, Seminar at National Institute of Fusion Science, Toki, Mar. (2003).
A. Saito: “Molecular resonances in 12 Be and 14 Be”,
Seminar of Molecular Structure from the Light
Neutron-rich Nuclei to the Medium Heavy Nuclei,(RIKEN), Wako, Mar. (2003).
Y. Motizuki: “RIBF nuclear astrophysics project: Towards understanding of supernova explosion mechanism and heavy element synthesis”, Workshop on
Nuclear Astrophysics - Strategies for Astro Nuclear
Reaction Studies, Wako, Mar. (2003).
A. Ozawa: “Reaction cross-section measurements in
RIBF”, Workshop on RI Beam Factory and Research Plan, Wako, Mar. (2003).
Y. Motizuki: “How to make a good presentation in
an international conference”, RIBF Nuclear Astrophysics Project Lecture Series 4, Wako, Apr. (2003).
Y. Motizuki: “Towards uniﬁed paradigm of corecollapse supernovae and nucleosynthesis of heavy elements”, Sendai Nuclear Science Colloq., (Tohoku
University), Sendai, Apr. (2003).
A. Ozawa: “Physics for unstable nuclei”, TAC Seminar
at University of Tsukuba, Tsukuba, Apr. (2003).
R. Mutou, J. Chiba, H. Enyo, Y. Fukao, H. Funahashi,
H. Hamagaki, M. Ieiri, M. Ishino, H. Kanda, M.
Kitaguchi, S. Mihara, K. Miwa, T. Miyashita, T.
Murakami, T. Nakura, M. Naruki, M. Nomachi,
K. Ozawa, F. Sakuma, O. Sasaki, M. Sekimoto,T. Tabaru, K. Tanaka, M. Togawa, S. Yamada,
S. Yokkaichi, and Y. Yoshimura: “Measurementof invariant mass spectra of vector meson decaying in nuclear matter at KEK-PS”, 8th Conf. on
the Intersections of Particle and Nuclear Physics(CIPANP 2003), (Brookhaven National Laboratory), New York, USA, May (2003).

Y. Motizuki: “44 Ti radioactivity in young supernova
remnants: Cas A and SN 1987A”, Int. Workshop on
Astronomy with Radioactivities 4th and Filling theSensitivity Gap in MeV Astronomy, (Max-PlanckInstitut fuer Extraterrestrische Physik), Seeon, Germany, May (2003).
A. Ozawa: “Recent progress of interaction and reaction cross-section measurements”, WE-HeraeusSeminar of Relativistic Structure Models for the
Physics of Radioactive Nuclear Beams, (WEHeraeus-Seminar), Bad Honnef, Germany, May(2003).
Y. Ishida, M. Wada, Y. Matsuo, I. Tanihata, A.
Casares, and H. Wollnik: “A multi-pass time-ofﬂight mass spectrometer of high resolving power”,
16th Int. Conf. on Ion Beam Analysis, (Bohmische
Physical Society and others), Albuquerque, USA,
June–July (2003).
K. Ishida: “Non-particle physics with intense muon
beams”, 5th Int. Workshop on Neutrino Factories& Superbeams (NuFact 03), (Columbia University),
New York, USA, June (2003).
T. Ichihara, M. Ishihara, H. Ohnuma, T. Niizeki, H.
Satou, H. Okamura, S. Kubono, M. H. Tanaka,
and Y. Fuchi: “Isoverctor quadrupole resonance observed in the 60 Ni(13 C, 13 N)60 Co reaction at E/A =100 MeV”, 8th Int. Conf. on Nucleus-Nucleus Collisions (NN 2003), (JINR), Moscow, Russia, June
(2003).
A. Ozawa: “Recent experiments for interaction andreaction cross-sections”, 8th Int. Conf. on NucleusNucleus Collisions (NN 2003), (JINR), Moscow,
Russia, June (2003).
D. Kameda, K. Asahi, H. Ueno, A. Yoshimi, H.
Watanabe, T. Haseyama, H. Miyoshi, K. Shimada,J. Murata, Y. Kobayashi, G. Kato, S. Emori, W.
Sato, and H. Ogawa: “Recent result from the nuclear
moment measurement using a spin polarized radioactive beam”, 8th Int. Conf. on Nucleus-Nucleus
Collisions (NN 2003), (Joint Institute for Nuclear
Research), Dubna, Russia, June (2003).
T. Gomi, T. Motobayashi, Y. Ando, N. Aoi, H.
Baba, K. Demichi, Z. Elekes, N. Fukuda, Z. Fulop,
U. Futakami, H. Hasegawa, Y. Higurashi, K. Ieki,
N. Imai, M. Ishihara, K. Ishikawa, N. Iwasa,
H. Iwasaki, S. Kanno, Y. Kondo, T. Kubo, S.
Kubono, M. Kunibu, K. Kurita, Y. Matsuyama, S.
Michimasa, T. Minemura, M. Miura, H. Murakami,
T. Nakamura, M. Notani, S. Ota, A. Saito, H.
Sakurai, M. Serata, S. Shimoura, T. Sugimoto,
E. Takeshita, S. Takeuchi, Y. Togano, K. Ue,
K. Yamada, Y. Yanagisawa, K. Yoneda, and A.
Yoshida: “Study of the 22 Mg(p,γ) 23 Al reaction with
the Coulomb-dissociation method”, 8th Int. Conf.
on Nucleus-Nucleus Collisions (NN 2003), (JINR),
Moscow, Russia, June (2003).
Y. Yanagisawa, M. Notani, H. Sakurai, S. Shimoura,337

H. Iwasaki, S. Michimasa, K. Ue, M. Kurokawa, N.
Iwasa, M. Kunibe, H. Baba, T. Gomi, A. Saito, T.
Minemura, Y. Matsuyama, H. Higurashi, S. Kanno,
M. Serata, E. Takeshita, S. Takeuchi, K. Yamada,H. Demichi, K. Hasegawa, H. Akiyoshi, N. Fukuda,
K. Yoneda, N. Aoi, N. Imai, T. Sugimoto, T.
Nakamura, M. Ishihara, and T. Motobayashi: “Theﬁrst excited oﬁn 30 Ne studied by proton inelastic
scattering in reversed kinematics”, 8th Int. Conf.
on Nucleus-Nucleus Collisions (NN 2003), (JINR),
Moscow, Russia, June (2003).
K. Asahi: “Measurements of nuclear moments for light
unstable nuclei”, Gordon Research Conf. on Nuclear
Chemistry, New London, USA, June (2003).
T. Ichihara, M. Ishihara, H. Ohnuma, T. Niizeki, Y.
Satou, H. Okamura, S. Kubono, M. H. Tanaka,
and Y. Fuchi: “Isoverctor quadrupole resonance observed in the 60 Ni(13 C, 13 N)60 Co reaction at E/A =100 MeV”, Int. Conf. on Collective Motion in Nuclei Under Extreme Conditions (COMEX 1), Paris,
France, June (2003).
Y. Motizuki: “Change of lifetime of 40 K orbital electron capture beta-decay under ultra-high pressures”,
Seminar at Gono Laboratory of Kyushu University,(Nishinippon Institute of Technology), Fukuoka,
June (2003).
S. Ozawa and M. Hamagaki: “Preparation of boron
ﬁlms by sputtering with electron-beam-excitedplasma”, Seventh Int. Symp. on Sputtering &Plasma Processes, (The Vacuum Society of Japan),Kanazawa, June (2003).
K. Sekiguchi, H. Sakai, H. Okamura, A. Tamii, T.
Uesaka, K. Suda, N. Sakamoto, T. Wakasa, Y.
Satou, T. Ohnishi, K. Yako, S. Sakoda, H. Kato,
Y. Maeda, J. Nishikawa, T. Saito, N. Uchigashima,
N. N. Kalantar, and K. Ermisch: “Measurement ofpolarization transfer coeﬃcients for d–p scattering
at intermediate energies and three nucleon force effects”, 17th Int. IUPAP Conf. on Few-Body Problems in Physics, Durham, USA, June (2003).
Y. Motizuki: “Sensitivity of core-collapse supernova
explosions to neutrino luminosity (invited talk)”,
1st Yamada Symp. on Neutrinos and Dark Matterin Nuclear Physics (NDM03), (Osaka University),
Nara, June (2003).
N. Dinh Dang: “Giant dipole resonance in hot nuclei”,
VIII Hispalensis Int. Summer School on Physics
of Exotic Nuclear Physics, (University of Seville),
Sevilla, Spain, June (2003).
N. Dinh Dang: “Modiﬁed Hartree-Fock-Bogoliubov
theory at ﬁnite temperature”, VIII Hispalensis
Int. Summer School on Physics of Exotic Nuclear
Physics, (University of Seville), Sevilla, Spain, June
(2003).
S. Sugimoto, H. Toki, and K. Ikeda: “Relativistic meanﬁeld theory with the pion for ﬁnite nuclei”, 22ndInt. Workshop on Nuclear Theory, (The Institute of338

Nuclear Research and Nuclear Energy of the Bulgarian Academy of Sciences), Rila Mountains, Bulgaria,
June (2003).
A. Yoshimi, K. Asahi, S. Emori, and M. Tsukui: “Nuclear spin oscillator and search for atomic EDMof 129 Xe”, Advanced Studies Institute: Symmetries
and Spin (Spin-Praha-2003), (Charles University),
Prague, Czech, July (2003).
M. Takashina: “A CDCC study of the breakup eﬀect
on 11 Be elastic acattering”, DREB 2003 Conf., (University of Surrey), Guildford, UK, July (2003).
K. Iida: “Ginzburg-Landau approach to color uperconductivity 30 min”, Finite Density QCD, (RCNP,
Osaka University), Nara, July (2003).
T. Sugihara: “Realization of lattice chiral symmetry
with hoppoing interacctions”, Int. Conf. on Color
Conﬁnement and Hadrons in Quantum Chromodynamics: Conﬁnement 2003, Wako, July (2003).
H. Ueno, K. Asahi, H. Ogawa, D. Kameda, H. Miyoshi,
A. Yoshimi, H. Watanabe, K. Shimada, W. Sato, K.
Yoneda, N. Imai, Y. Kobayashi, M. Ishihara, and
W.-D. Schmidt-Ott: “Nuclear moments of nuclei
in the neighborhood of the neutron drip line”, Int.
Conf. on the Labyrinth in Nuclear Structure, (NCSR
Demokritos), Crete, Greece, July (2003).
T. Sugihara: “Chiral symmetry on a lattice with hopping interactions”, LATTICE 2003: 21st Int. Symp.
on Lattice Field Theory, Tsukuba, July (2003).
N. Ishii and H. Suganuma: “MEM analysis of glueball correlators at T > 0”, LATTICE 2003: 21stInt. Symp. on Lattice Field Theory, Tsukuba, July
(2003).
T. Izubushi: “The Kaon B parameter from two-ﬂavor
dynamical domain wall fermions”, LATTICE 2003:
21st Int. Symp. on Lattice Field Theory, Tsukuba,
July (2003).
A. Ozawa: “Fast PID system and its applications”,
RIKEN Symp. on Advanced Signal Processing in
Nuclear Physics, Wako, July (2003).
Y. Motizuki: “Element genesis: Mystery in universe
studying with RI”, Seminar of Physics Department
at Tokyo University of Science, Noda, July (2003).
Y. Motizuki:“Core-collapse supernovae withanisotropic neutrino radiation”, Int. Conf. in
Hohour of the 60th Birthday of Marcel Arnould:
The Future Astronuclear Physics; From Microscopic
Puzzles to Macroscopic Nightmares, (University
Libre de Bruxelles), Brussels, Bergium, Aug. (2003).
Y. Motizuki: “Required accuracy of mass and halﬂife
measurements for the r-process nucleosynthesis”,
Int. Conf. in Hohour of the 60th Birthday of Marcel
Arnould: The Future Astronuclear Physics; From
Microscopic Puzzles to Macroscopic Nightmares,(University Libre de Bruxelles), Brussels, Bergium,
Aug. (2003).
K. Sekiguchi, H. Sakai, H. Okamura, A. Tamii, T.
Uesaka, K. Suda, N. Sakamoto, T. Wakasa, Y.

Satou, T. Ohnishi, K. Yako, S. Sakoda, H. Kato,
Y. Maeda, J. Nishikawa, T. Saito, N. Uchigashima,
N. N. Kalantar, and K. Ermisch: “Measurementof deuteron-proton scattering at intermediate energies”, RCNP Workshop: Few Body Systems andBaryon-Baryon Interactions, Osaka, Aug. (2003).
S. Fujii, H. Kamada, R. Okamoto, and K. Suzuki: “Application of low-momentum interaction to the calculation for few-nucleon systems”, RCNP Workshop:
Few-Nucleon Systems and Baryon-Baryon Interaction, Ibaraki, Aug. (2003).
H. Koura: “Stability and decay modes of superheavy
elements from a viewpoint of atomic mass formulas”, Summer School of Nuclear Chemistry, (TheJapan Society of Nuclear and Radiochemical Sciences), Daigo-cho, Ibaraki Pref., Aug. (2003).
H. Koura: “Ground-state properties of heavy and superheavy nuclei predicted by nuclear mass models”,
Tours Symp. on Nuclear Physics V (TOURS 2003),(Konan University), Tours, France, Aug. (2003).
Y. Motizuki: “Radioactivity of the key isotope 44 Ti
in supernovae (invited talk)”, Tours Symp. on Nuclear Physics V (TOURS 2003), (Konan University),
Tours, France, Aug. (2003).
K. Iida: “Color superconductivity in ﬁnite quark matter”, YITP Workshop on Thermal Quantum Field
Theories and Their Application, Kyoto, Aug. (2003).
Z. Elekes, G. Kalinka, Z. Fulop, J. Gal, J. Molnar, G.
Hegyesi, D. Novak, T. Motobayashi, A. Saito, andY. Yanagisawa: “Optimization of the performanceof a CsI(Tl) scintillator+Si PIN photodiode detector for medium-energy light-charged particle hybrid
array”, 17th Int. Nuclear Physics Divisional Conf.
of the European Physical Soc. (NPDC-17)): Nuclear Physics in Astrophysics, (ATOMKI), Debrecen, Hungary, Sept.–Oct. (2003).
Y. Motizuki: “Ionization and nucleosynthesis of 44 Ti
in Cassiopeia A”, 2003 Fall Ann. Meet. of Astrophysical Soc. of Japan, Matsuyama, Sept. (2003).
S. Sugimoto, H. Toki, and K. Ikeda: “Application of
charge-number- and parity-projected Hartree-Fockmethod for ﬁnite nuclei”, 2003 Fall Meet. of the
Physical Soc. of Japan, Miyazaki and Okayama,
Sept. (2003).
S. Fujii, H. Kamada, R. Okamoto, and K. Suzuki:“Calculations for three- and four-nucleon systems
using low-momentum interactions derived from realistic nucleon-nucleon forces”, 2003 Fall Meet. of
the Physical Soc. of Japan, Miyazaki and Okayama,
Sept. (2003).
K. Iida and K. Oyamatsu: “Density dependence of thesurface tension: nucleon density in the nuclear interior and neutron skin”, 2003 Fall Meet. of the Physical Soc. of Japan, Miyazaki and Okayama, Sept.
(2003).
A. Kohama: “Density shape dependence of the protonnucleus elastic scattering cross section”, 2003 Fall

Meet. of the Physical Soc. of Japan, Miyazaki andOkayama, Sept. (2003).
H. Miyadera, K. Nagamine, K. Simomura, K.
Nishiyama, H. Tanaka, Y. Ikedo, and K. Ishida:“Development of large solid angle axial focusing surface muon channel at KEK-MSL”, 2003 Fall Meet. of
the Physical Soc. of Japan, Miyazaki and Okayama,
Sept. (2003).
H. Watanabe, Y. Gounou, B. Cederwall, N. Hokoiwa,
M. Ishihara, M. Kibe, T. Kishida, K. Lagergren,
A. Odahara, Z. Podolyak, T. Sasaki, and Y. Wakabayashi: “Experimental progress in the projectof high-spin isomer beam at RIKEN”, 2003 Fall
Meet. of the Physical Soc. of Japan, Miyazaki andOkayama, Sept. (2003).
Y. Matsuda, P. Bakule, P. Strasser, Y. Miyake, K.
Nagamine, K. Simomura, S. Makimura, M. Iwasaki,
T. Matsuzaki, and K. Ishida: “Generation of slow
muon beam at the RIKEN-RAL muon facility (II)”,
2003 Fall Meet. of the Physical Soc. of Japan,
Miyazaki and Okayama, Sept. (2003).
K. Ishida, K. Nagamine, T. Matsuzaki, N. Kawamura,
Y. Matsuda, M. Iwasaki, H. Imao, M. Kato, H.
Sugai, M. Tanase, S. Nakamura, K. Kudo, N.
Takeda, and G. H. Eaton: “Muon catalyzed fusion
experiment in D-T system at RIKEN-RAL Muon
Facility: magnetic ﬁeld eﬀect”, 2003 Fall Meet. of
the Physical Soc. of Japan, Miyazaki and Okayama,
Sept. (2003).
A. Yoshimi: “Nuclear spin maser with 129 Xe and thesearch for the atomic EDM”, 2003 Fall Meet. of
the Physical Soc. of Japan, Miyazaki and Okayama,
Sept. (2003).
K. Morimoto: “Recent status of super heavy element
research at RIKEN”, 2003 Fall Meet. of the PhysicalSoc. of Japan, Miyazaki and Okayama, Sept. (2003).
S. Fujii, R. Okamoto, and K. Suzuki: “Shell structuresof neutron-rich O isotopes described with modern
nucleon-nucleon interactions II”, 2003 Fall Meet. of
the Physical Soc. of Japan, Miyazaki and Okayama,
Sept. (2003).
K. Suda, H. Okamura, T. Uesaka, H. Kumasaka, R.
Suzuki, T. Ikeda, K. Itoh, H. Sakai, A. Tamii, K.
Sekiguchi, K. Yako, Y. Maeda, M. Hatano, T. Saito,
H. Kuboki, N. Sakamoto, and Y. Satou: “Studyof spin-isospin responses in doubly magic nucleus
16O”, 2003 Fall Meet. of the Physical Soc. of Japan,
Miyazaki and Okayama, Sept. (2003).
Y. Motizuki, T. Tachibana, and S. Goriely: “The rprocess nucleosynthesis: diﬀerence produced by microscopic and semi-empirical mass formulae”, 2003
Fall Meet. of the Physical Soc. of Japan, Miyazaki
and Okayama, Sept. (2003).
T. Matsuzaki, K. Nagamine, N. Kawamura, K. Ishida,
Y. Matsuda, M. Iwasaki, H. Imao, M. Kato, H.
Sugai, M. Tanase, S. Nakamura, K. Kudo, N.
Takeda, and G. H. Eaton: “n-α particle correla-339

tions observed in the muon catalyzed t-t fusion reactions”, 2003 Fall Meet. of the Physical Soc. of Japan,
Miyazaki and Okayama, Sept. (2003).
M. Kobayashi, K. Ushida, Y. Aoki, T. Kuribayashi, M.
Kawaguchi, S. Kashiwagi, R. Kuroda, Y. Hama, andM. Washio: “Construction of pulse radiolysis systemwith a picosecond RF-gun at Waseda University”,
46th Symp. on Radiation Chemistry, (Japanese Society of Radiation Chemistry), Hakone, Sept. (2003).
H. Watanabe, K. Asahi, H. Ueno, W. Sato, A. Yoshimi,
Y. Kobayashi, J. Murata, T. Kishida, M. Ishihara,
D. Kameda, H. Miyoshi, K. Shimada, Y. Gounou,
T. Fukuchi, Y. Wakabayashi, T. Sasaki, M. Kibe, N.
Hokoiwa, A. Odahara, B. Cederwall, K. Lagergren,and Z. Podolyak: “Application of the high-spin isomer beams to secondary fusion reaction and measurement of g-factors”, 6th Int. Conf. on Radioactive
Nuclear Beams (RNB6), (Argone National Laboratory), Argonne, USA, Sept. (2003).
K. Yamada, T. Motobayashi, and I. Tanihata: “RF deﬂector system for proton-rich RI beams in RIKEN”,
6th Int. Conf. on Radioactive Nuclear Beams(RNB6), (Argonne National Laboratory), Argonne,
USA, Sept. (2003).
T. Matsuzaki, K. Nagamine, K. Ishida, N. Kawamura,
H. Imao, Y. Matsuda, M. Iwasaki, M. Kato, H.
Sugai, M. Tanase, S. Nakamura, K. Kudo, N.
Takeda, and G. H. Eaton: “Strong n-alpha correlations in the t+t fusion reactions observed in themuon catalyzed t-t fusion”, Int. Conf. on FUSION3:
From a Tunneling Nuclear Microscope to Nuclear
Processes in Matter, (Tohuku University and others), Miyagi, Nov. (2003).
H. Watanabe, K. Asahi, H. Ueno, W. Sato, A. Yoshimi,
Y. Kobayashi, J. Murata, T. Kishida, M. Ishihara,
D. Kameda, H. Miyoshi, K. Shimada, Y. Gounou,
T. Fukuchi, M. Kibe, N. Hokoiwa, T. Sasaki, B.
Cederwall, K. Lagergren, A. Odahara, Z. Podolyak,
and Y. Wakabayashi: “Application of the high-spin
isomer beams to secondary fusion reaction and measurement of g-factors”, Int. Symp. on A New Eraof Nuclear Structure Physics (NENS03), (Niigata
University), Kurokawa-mura, Niigata Pref., Nov.
(2003).
K. Iida, K. Oyamatsu, and B. A. Sarhan: “Deducing
the density dependence of the symmetry energy fromunstable nuclei”, Int. Symp. on A New Era of Nuclear Structure Physics (NENS03), (Niigata University), Kurokawa-mura, Niigata Pref., Nov. (2003).
A. Kohama: “Determination of matter surface distribution of neutron-rich nuclei”, Int. Symp. on A
New Era of Nuclear Structure Physics (NENS03),
Kurokawa-mura, Niigata Pref., Nov. (2003).
H. Miyoshi, K. Asahi, S. Emori, T. Haseyama, D.
Kameda, G. Kato, Y. Kobayashi, J. Murata, H.
Ogawa, K. Sakai, W. Sato, K. Shimada, H. Ueno, H.
Watanabe, and W.-D. Schmidt-Ott: “Low-energy

340of polarized RI atomic beam”, Int. Symp. on A
New Era of Nuclear Structure Physics (NENS03),(Niigata University), Kurokawa-mura, Niigata Pref.,Nov. (2003).
K. Sekiguchi: “Measurement of nucleon-deuteron scattering as a good probe to study three nucleon force”,
Int. Symp. on A New Era of Nuclear Structure
Physics (NENS03), (Niigata University), Kurokawamura, Niigata Pref., Nov. (2003).
S. Fujii, R. Okamoto, and K. Suzuki: “Shell structures in nuclei around 24 O described with modern nucleon-nucleon interactions”, Int. Symp. on A
New Era of Nuclear Structure Physics (NENS03),(Niigata University), Kurokawa-mura, Niigata Pref.,Nov. (2003).
D. Kameda, K. Asahi, H. Ueno, A. Yoshimi, H.
Watanabe, T. Haseyama, H. Miyoshi, K. Shimada,G. Kato, S. Emori, G. Kijima, Y. Kobayashi, J.
Murata, W. Sato, and H. Ogawa: “g-factor measurement for 19 N”, Int. Symp. on A New Era of Nuclear
Structure Physics (NENS03), (Niigata University),
Niigata, Nov. (2003).
T. Gomi, T. Motobayashi, Y. Ando, N. Aoi, H.
Baba, K. Demichi, Z. Elekes, N. Fukuda, Z. Fulop,
U. Futakami, H. Hasegawa, Y. Higurashi, K. Ieki,
N. Imai, M. Ishihara, K. Ishikawa, N. Iwasa,
H. Iwasaki, S. Kanno, Y. Kondo, T. Kubo, S.
Kubono, M. Kunibu, K. Kurita, Y. Matsuyama, S.
Michimasa, T. Minemura, M. Miura, H. Murakami,
T. Nakamura, M. Notani, S. Ota, A. Saito, H.
Sakurai, M. Serata, S. Shimoura, T. Sugimoto,
E. Takeshita, S. Takeuchi, Y. Togano, K. Ue,
K. Yamada, Y. Yanagisawa, K. Yoneda, and A.
Yoshida: “Coulomb dissociation of 23 Al: Study ofthe 22 Mg(p,γ) 23 Al reaction”, Int. Symp. on theOrigin of Matter and Evolution of Galaxies 2003
(OMEG-03), (CNS, RIKEN and others), Wako,
Nov. (2003).
Y. Motizuki: “A proposal for nuclear γ-ray astronomy
using NeXT satellite”, Science Meet. for the NeXT
Satellite, (University of Tokyo), Tokyo, Nov. (2003).
M. Takashina, M. Ito, Y. Kudo, S. Okabe, and Y.
Sakuragi: “12 C + 12 C → 8 Beg.s. + 16 Og.s. resonance reactions and multi-cluster states of highly
excited 24 Mg nucleus”, 8th Int. Conf. on Clustering Aspects of Nuclear Structure and Dynamics(CLUSTER ’03), (RIKEN and Kyoto University),
Nara, Nov. (2003).
S. Sugimoto, K. Ikeda, and H. Toki: “Charge- andparity-projected Hartree-Fock study with the tensor force of light nuclei”, 8th Int. Conf. on Clustering Aspects of Nuclear Structure and Dynamics(CLUSTER ’03), (RIKEN and Kyoto University),
Nara, Nov. (2003).
H. Ueno, K. Asahi, H. Ogawa, D. Kameda, H. Miyoshi,
A. Yoshimi, H. Watanabe, K. Shimada, W. Sato, K.
Yoneda, N. Imai, Y. Kobayashi, M. Ishihara, andW.-D. Schmidt-Ott: “Measurement of nuclear moments in the region of light neutron-rich nuclei”, 8thInt. Conf. on Clustering Aspects of Nuclear Structure and Dynamics (CLUSTER ’03), (RIKEN and
Kyoto University), Nara, Nov. (2003).
A. Kohama: “Neutron-rich nuclei and the protonnucleus elastic scattering”, 8th Int. Conf. on Clustering Aspects of Nuclear Structure and Dynamics(CLUSTER ’03), (RIKEN and Kyoto University),
Nara, Nov. (2003).
K. Ikeda: “New mean ﬁeld theory with parity andcharge mixing for ﬁnite nuclei”, 8th Int. Conf. on
Clustering Aspects of Nuclear Structure and Dynamics (CLUSTER ’03), (RIKEN and Kyoto University), Nara, Nov. (2003).
K. Morimoto: “Status of super heavy element researchusing GARIS at RIKEN”, 8th Int. Conf. on Clustering Aspects of Nuclear Structure and Dynamics(CLUSTER ’03), (RIKEN and Kyoto University),
Nara, Nov. (2003).
A. Yoshimi, H. Ueno, W. Sato, H. Watanabe, Y.
Kobayashi, J. Murata, H. Miyoshi, K. Shimada, andK. Asahi: “The g-factor measurement on excitedstates of unstable nuclei by a transient ﬁeld method:development of a detector system”, 8th Int. Conf.
on Clustering Aspects of Nuclear Structure and Dynamics (CLUSTER ’03), (RIKEN and Kyoto University), Nara, Nov. (2003).
S. Yokkaichi: “Data processing in Nuclear/Particle
Physics using Accelerator and PC cluster”, RIKEN
Symp. on New Horizon on HPC, Wako, Dec. (2003).
T. Sugihara: “Lattice representation of vector and chiral gauge theories”, YITP Workshop on Fundamental Problems and Applications of Quantum Field
Theory, Kyoto, Dec. (2003).
K. Iida, K. Oyamatsu, and B. A. Sarhan: “Deducing
the density dependence of the symmetry energy fromunstable unclei”, YITP Workshop on Nuclear Matter under Extreme Conditions (Matter03), Kyoto,
Dec. (2003).
A. Kohama: “Determination of matter surface distribution of neutron-rich nuclei and eﬀect of outer surface”, YITP Workshop on Nuclear Matter under Extreme Conditions (Matter03), Kyoto, Dec. (2003).
R. Mutou, J. Chiba, H. Enyo, Y. Fukao, H. Funahashi,
H. Hamagaki, M. Ieiri, M. Ishino, H. Kanda, M.
Kitaguchi, S. Mihara, K. Miwa, T. Miyashita, T.
Murakami, T. Nakura, M. Naruki, M. Nomachi, K.
Ozawa, F. Sakuma, O. Sasaki, H. Sato, M. Sekimoto,T. Tabaru, K. Tanaka, M. Togawa, S. Yamada,
S. Yokkaichi, and Y. Yoshimura: “Experimental
signature of in-medium mass modiﬁcation of vector mesons at normal nuclear density”, 17th Int.
Conf. on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2004), (Lawrence Berkeley National Laboratory and others), Oakland, USA, Jan.
(2004).

S. Yokkaichi, K. Ozawa, and S. Sawada: “Vector meson measurements at J-PARC 50-GeV PS”, 17th Int.
Conf. on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2004), (Lawrence Berkeley National Laboratory and others), Oakland, USA, Jan.
(2004).
A. Yoshimi, K. Asahi, S. Emori, and M. Tsukui:“Laser-polarized nuclei of 129 Xe and the precise
control of nuclear spin precession”, 2003 Conf. on
Atom-Molecular Process in Cosmic Space, (JAXA),
Sagamihara, Jan. (2004).
Y. Motizuki: “Element genesis in the universe: How
luckily we exist here”, Dai-13-Kai Housha-sen Riyou
Sougou Symp., (Osaka Nuclear Science Association),
Osaka, Jan. (2004).
K. Asahi: “Polarized 3 He gas as a polarizer and analyzer for the spin of low-energy neutron”, Int. Conf.
on Neutron Optics (NOP2004), (MEXT), Tokyo,
Jan. (2004).
K. Iida: “Color superconductivity”, KEK Large Scale
Simulation Program Workshop: Hadron Physics andLattice QCD, Tsukuba, Jan. (2004).
Y. Terada, Y. Motizuki, T. Tamagawa, K. Makishima,
T. Takahashi, K. Yamaoka, Y. Okada, and S. Hong:“New physics expanded by observing nuclear γ-rays
with the NeXT satellite”, 4th Space Science Symp.,(JAXA/ISAS), Sagamihara, Jan. (2004).
H. Miyoshi, K. Asahi, S. Emori, T. Haseyama, D.
Kameda, G. Kato, Y. Kobayashi, J. Murata, H.
Ogawa, K. Sakai, W. Sato, K. Shimada, H. Ueno,
H. Watanabe, and W.-D. Schmidt-Ott: “Atomic
beam method for the fragmentation-based radioactive beams”, 1st Tokyo Tech Physics COE Symp.
on Spin and Quantum Structure in Hadrons, Nuclei
and Atoms (SQS04), Tokyo, Feb. (2004).
D. Kameda, K. Asahi, H. Ueno, A. Yoshimi, H.
Watanabe, T. Haseyama, J. Murata, Y. Kobayashi,
W. Sato, H. Miyoshi, K. Shimada, G. Kato, S.
Emori, G. Kijima, T. Suga, H. Ogawa, K. Oono, K.
Yoneda, N. Imai, A. Yoshida, T. Kubo, M. Ishihara,
K. Yogo, and K. Sakai: “Nuclear moment studies
with spin polarized radioactive beams from fragmentation reaction”, 1st Tokyo Tech Physics COE
Symp. on Spin and Quantum Structure in Hadrons,
Nuclei and Atoms (SQS04), Tokyo, Feb. (2004).
A. Yoshimi, K. Asahi, S. Emori, and M. Tsukui: “Nuclear spin maser with a novel masing mechanism
and its application to the search for an atomic EDM
in 129 Xe”, 1st Tokyo Tech Physics COE Symp. on
Spin and Quantum Structure in Hadrons, Nuclei andAtoms (SQS04), Tokyo, Feb. (2004).
H. Watanabe, H. Ueno, A. Yoshimi, Y. Kobayashi, T.
Kishida, Y. Gounou, A. Odahara, and T. Haseyama:“g-factor measurements of high-spin isomers andcondensed matter studies using spin-aligned isomeric beams”, 1st Tokyo Tech Physics COE Symp.
on Spin and Quantum Structure in Hadrons, Nuclei

341

and Atoms (SQS04), Tokyo, Feb. (2004).
H. Madokoro, T. Shimizu, and Y. Motizuki: “2-D numerical simulation of core-collapse supernova explosions with Roe’s method in second order accuracy”,
2004 Spring Ann. Meet. of Astrophysical Soc. ofJapan, Nagoya, Mar. (2004).
Y. Motizuki and S. Kumagai: “Detectability of 44 Ti
nuclear γ-rays from SNR 1987A”, 2004 Spring Ann.
Meet. of Astrophysical Soc. of Japan, Nagoya, Mar.
(2004).
H. Madokoro, T. Shimizu, and Y. Motizuki: “2-D numerical simulation of core-collapse supernova explosions with Roe’s method”, 59th Ann. Meet. of Physical Soc. of Japan, Fukuoka, Mar. (2004).
Y. Motizuki: “Change in orbital-electron-capturebeta-decay lifetime of 40 K under ultra-high pressures”, 59th Ann. Meet. of Physical Soc. of Japan,
Fukuoka, Mar. (2004).
H. Watanabe, K. Asahi, H. Ueno, A. Yoshimi, T.
Haseyama, T. Kishida, Y. Kobayashi, D. Kameda,
H. Miyoshi, K. Shimada, Y. Gounou, and A.
Odahara: “g-factor measurements of high-spin isomers and condensed matter studies with γ-TDPAD
technique”, CNS-RIKEN Joint Symp. on Frontier ofgamma-ray spectroscopy and its application, Wako,
Mar. (2004).
H. Watanabe, K. Asahi, H. Ueno, A. Yoshimi, Y.
Kobayashi, T. Haseyama, T. Kishida, D. Kameda,
H. Miyoshi, K. Shimada, S. Emori, G. Kato, Y.
Gounou, and A. Odahara: “g-factor measurementsof high-spin isomers and condensed matter studies using spin-aligned isomeric beams”, 5th JapanChina Joint Nuclear Physics Symp., (Kyushu University), Fukuoka, Mar. (2004).

3. Atomic and solid-state physics
M. Wada: “On-line collection of energetic Li-8 ionsby RF ion-guide”, Workshop on TRIUMF-TRAP: A
facility for exotic and Highly Charged Ion Beams at
ISAC, (TRIUMF (Canada’s National Laboratory for
Particle and Nuclear Physics)), Vancouver, Canada,
Apr. (2002).
M. Wada: “Slow/trapped RI-beams from PF separators”, 14th Int. Conf. on Electromagnetic Isotope
Separators and Techniques Related to their Applications, (TRIUMF), Victoria, Canada, May (2002).
S. Ohira, K. Awaga, W. Fujita, I. Watanabe, and K.
Nagamine: “µSR study on a metal complex having
a ferromagnetic linear chain p-NPNN·Cu(hfac)2 ”,
9th Int. Conf. on Muon Spin Rotation/Relaxation/
Resonance (µSR2002), Williamsburg, USA, June
(2002).
S. Fujii: “Microscopic eﬀective YN interaction forshell-model calculation and structure of 16
Λ O”, Nuclear Theory Seminar at Chiba University, Chiba,
June (2002).

342

Y. Nagashima, F. Saito, Y. Ito, A. Goto, and T.
Hyodo: “Study of X-ray emission by positron impact”, Workshop on Studies on Reliability of Advanced Pressure Boundary Materials Used in Extremely Severe Environments on Nuclear Energy
Systems Research and Development of Advanced
Positron Beam Applications: Functional Materials
and Beam Technology, Takasaki, Aug. (2002).
T. Kambara, K. Kageyama, Y. Kanai, T. Kojima,
Y. Nakai, A. Yoneda, and Y. Yamazaki: “Elastic
wave from GeV heavy-ion irradiations on solids”,
13th Int. Conf. on Ion Beam Modiﬁcation of Materials (IBMM 2002), (The Japan Society of Applied
Physics), Kobe, Sept. (2002).
S. Ohira, K. Awaga, W. Fujita, I. Watanabe, and K.
Nagamine: “µSR study on magnetic property of pNPNN·Cu(hfac)2 ”, 2002 Fall Meet. of the PhysicalSoc. of Japan, Kasugai, Sept. (2002).
T. Kojima, N. Oshima, M. Niigaki, A. Mohri, and Y.
Yamazaki: “Creation of positron plasmas in ultrahigh vacuum environment”, 2002 Fall Meet. of the
Physical Soc. of Japan, Kasugai, Sept. (2002).
T. Kambara, Y. Kanai, Y. Nakai, T. Ikeda, N.
Fukunishi, Y. Takabayashi, T. Azuma, K. Komaki,
and Y. Yamazaki: “High-resolution spectroscopy ofhighly-charged ions utilizing a virtual-photon ﬁeld
in a single crystal”, 2002 Fall Meet. of the PhysicalSoc. of Japan, Kasugai, Sept. (2002).
Y. Nagashima, F. Saito, Y. Ito, A. Goto, and T.
Hyodo: “Measurement of inner-shell ionization crosssections by positron impact”, 2002 Fall Meet. of the
Physical Soc. of Japan, Kasugai, Sept. (2002).
M. Niigaki, T. Kojima, N. Oshima, and A. Mohri:“RIKEN HCI TRAP IV: Positron accumulation using a high-density electron plasma”, 2002 Fall Meet.
of the Physical Soc. of Japan, Kasugai, Sept. (2002).
A. Igarashi, M. Kimura, and I. Shimamura: “Positronannihilation in collisions with atoms: A solution to
the pathological problem with the conventional theory”, 5th Asian Int. Seminar on Atomic and Molecular Physics (AISAMP 5), (Advanced Photon Research Center Kansai Research, JAERI), Nara, Oct.
(2002).
T. Hirade, N. Suzuki, F. Saito, A. Goto, andT. Hyodo: “Positronium formation at low temperatures”, 45th Symp. on Radiation Chemistry,
Kasuga, Oct. (2002).
I. Shimamura, A. Igarashi, and M. Kimura: “Annihilation of low energy positorons in hydrogen”, 17th
Int. Conf. on the Application of Accelerators in Research and Industry (CAARI 2002), (University ofNorth Tecas), Denton, USA, Nov. (2002).
K. Wada, Y. Nagashima, F. Saito, Y. Ito, A. Goto,
and T. Hyodo: “Improvement of the positron spinpolarization measurement using positron lifetime”,
Specialist Research Meet. on Positron Beam Techniques and Condensed Matter, Kumatori-cho, OsakaPref., Nov. (2002).
Y. Nagashima, F. Saito, Y. Itoh, A. Goto, and T.
Hyodo: “Ionization cross sections for Cu K-shell andAg L-shell by positron impact”, Specialist Research
Meet. on Positron Beam Techniques and Condensed
Matter, Kumatori-cho, Osaka Pref., Nov. (2002).
M. Niigaki, T. Kojima, N. Oshima, A. Mohri, K.
Komaki, and Y. Yamazaki: “Production of ultraslow HCI beams sympathetically cooled by a cold
positron plasma”, 8th Japan-Russia Int. Symp. on
Interaction of Fast Charged Particles with Solids,(Quantum Science and Engineering Center andKyoto University), Kyoto, Nov. (2002).
N. Oshima, T. Kojima, M. Niigaki, A. Mohri,
K. Komaki, and Y. Yamazaki: “Development of
positron accumlator for cooling highly chargedions”, Scientiﬁc Meet. of the Research Reactor Institute, Kyoto University, Kumatori-cho, Osaka Pref.,Nov. (2002).
A. Igarashi, M. Kimura, and I. Shimamura: “Inseparable positron annihilation and positronium formation in positron-hydrogen collisions”, JSPS-NSF
and RIKEN Joint Workshop on Resonances inPhysics, Chemistry and Biology (US-Japan Workshop), Hayama, Dec. (2002).
Y. Nagashima, F. Saito, Y. Itoh, A. Goto, and T.
Hyodo: “Si(Li) detector for the measurement of Xrays by positron impact”, 17th Workshop on Radiation Detectors and Their Uses, (KEK), Tsukuba,Jan. (2003).
K. Kimura: “Ultra fast luminescence in heavy-ion
track cores in insulators: electron-hole plasma (invited talk)”, 20th Int. Conf. on Atomic Collisions
in Solids (ICACS 20), (University of Hyderabad andInstitute of Physics, Bhubaneswar), Puri, India, Jan.
(2003).
S. Ohira: “Studies on magnetic properties of organic
materials by using muon”, RIKEN Symp. on Studies
on Condensed Matter Physics, Atomic Physics, Hyperﬁne Interactions and Biomedical Sciences Using
RIKEN Accelerators, Wako, Feb. (2003).
M. Wada: “Eﬃcient collection of energetic Li-8 ionsby rf ion guide”, Workshop on Physics Applicationsof Medical Use Particle Accelerator, (National Institute of Radiological Sciences), Chiba, Feb. (2003).
E. Yagi, S. Koike, T. Matsumoto, T. Urai, N. Tajima,
and K. Ogiwara: “Change of state of hydrogen in
Nb-Mb alloys with Mo concentration”, 58th Ann.
Meet. of Physical Soc. of Japan, Sendai, Mar. (2003).
Y. Nakai, Y. Kanai, Y. Iwai, Y. Yamazaki, H. Masuda,
and K. Nishio: “Coincidence measurement of x-rays
with ﬁnal charge states of highly charged ions transmitted through a microcapillary target”, 58th Ann.
Meet. of Physical Soc. of Japan, Sendai, Mar. (2003).
Y. Iwai, Y. Kanai, Y. Nakai, T. Ikeda, H. Oyama, K.
Ando, H. Masuda, K. Nishio, M. Nakao, H. Torii,
and K. Komaki: “High resolution soft X-ray sec-

troscopy using a single photon counting method”,
58th Ann. Meet. of Physical Soc. of Japan, Sendai,
Mar. (2003).
S. Ohira, M. Tamura, R. Kato, and I. Watanabe:“Magnetic property of the [Pd(dmit)2 ] salts studied
by the µSR method”, 58th Ann. Meet. of PhysicalSoc. of Japan, Sendai, Mar. (2003).
H. Shimada, Y. Nakai, H. Oyama, K. Ando, T.
Kambara, A. Hatakeyama, and Y. Yamazaki: “Measurement of the momentum distributions of multiply charged ions produced by an intense laser”, 58th
Ann. Meet. of Physical Soc. of Japan, Sendai, Mar.
(2003).
M. Niigaki, T. Kojima, N. Ohshima, A. Mohri, andY. Yamazaki: “RIKEN HCI Trap V: Optimization of positron trapping with high-density electron
plasma”, 58th Ann. Meet. of Physical Soc. of Japan,
Sendai, Mar. (2003).
M. Hoshino, Y. Kanai, M. Yanagisawa, Y. Nakai, M.
Kitajima, h. Tanaka, and Y. Yamazaki: “The stateslective angular distributions of single- and doubleelectron capture processes for X4+ (X=C, N)-He collision in the energy range below 100 eV/q”, 58th
Ann. Meet. of Physical Soc. of Japan, Sendai, Mar.
(2003).
Y. Matsuo: “Spectroscopic behavior of atoms and ionsin liquid and cold gas He”, Chemistry in Quantum
Condensed Phases, (Morino Foundation), Kyoto,Mar. (2003).
N. Oshima, T. Kojima, M. Niigaki, A. Mohri, K.
Komaki, and Y. Yamazaki: “Eﬃcient positron
trapping in a cryogenic vacuum with an electron
plasma”, Int. Conf. on Low Energy Antiproton
Physics (LEAP ’03), (Antimatter Science Project,
University of Tokyo, RIKEN and KEK), Yokohama,Mar. (2003).
M. Wada: “Technical developments toward antiprotonic radioactive nuclear atoms for nuclear structure study”, Int. Conf. on Low Energy Antiproton
Physics (LEAP ’03), (Antimatter Science Project,
University of Tokyo, RIKEN and KEK), Yokohama,Mar. (2003).
N. Oshima: “Formation of a non-neutral positronplasma and its application”, Mini Workshop on
Generation of High-Energy Synchrotron Radiation
by Superconducting Wiggler and Its Application,(SPring-8), Harima, Mar. (2003).
E. Yagi: “State of hydrogen in Nb-based bcc alloys”,
Symp. on the Role of Hydrogen in the Embrittlement of Structural Materials in the Environmental Atmosphere, (Iron and Steel Institute of Japan),Tokyo, Mar. (2003).
M. Wada: “Deceleration and cooling of RI beams,:
from GeV to µeV”, Int. Workshop on Beam Coolingand Related Topics (COOL03), (RIKEN and CNS),
Yamanashi, May (2003).
A. Takamine: “On-line test of an rf-ion guide for col-343

lecting energetic Li-8 beams”, Workshop on Slow RIBeams and Related Topics, (RIKEN), Wako, May(2003).
M. Wada: “The slow RI-beam facility at RIKEN
RIBF”, Workshop on Slow RI-Beams and Related
Topics, (RIKEN), Wako, May (2003).
N. Nakamura: “Tokyo EBIT and possibility for highly
charged RI ion”, Workshop on Slow RI-Beams andRelated Topics, (RIKEN), Wako, May (2003).
N. Ohshima: “Positron accumulation with an electron plasma”, 12th Int. Workshop on Low Energy
Positron and Positronium Physics, (University of
Aarhus), Sandbjerg, Denmark, July (2003).
N. Yamanaka, Y. Kino, Y. Takano, H. Kudo, and A.
Ichimura: “Enhancement of direct positron annihilation due to temporal capture during a collision”,
23rd Int. Conf. on Photonic Electronic and Atomic
Collisions (ICPEAC 2003), Stockholm, Sweden, July
(2003).
H. Shimada, Y. Nakai, H. Oyama, K. Ando, T.
Kambara, A. Hatakeyama, and Y. Yamazaki: “Measurement of the momentum distribution of argon
ions produced by an intense laser light”, 23rd Int.
Conf. on Photonic Electronic and Atomic Collisions(ICPEAC 2003), Stockholm, Sweden, July (2003).
Y. Kanai, Y. Nakai, Y. Iwai, K. Nishio, H. Masuda,
and Y. Yamazaki: “Measurements of X-rays fromhighly charged ion transmitted through a Ni microcapillary”, 23rd Int. Conf. on Photonic Electronicand Atomic Collisions (ICPEAC 2003), Stockholm,
Sweden, July (2003).
A. Takamine, M. Wada, Y. Ishida, T. Nakamura,T. Kambara, H. Oyama, Y. Kanai, T. Kojima,
Y. Nakai, A. Yoshida, T. Kubo, Y. Matsuo,
Y. Fukuyama, K. Okada, T. Sonoda, K. Noda,
S. Ohtani, H. Kawakami, I. Katayama, and Y.
Yamazaki: “On-line collection of energetic 8 Li ionsfrom a projectile fragment separator using an RF
ion-guide”, 23rd Int. Conf. on Photonic Electronicand Atomic Collisions (ICPEAC 2003), Stockholm,
Sweden, July (2003).
A. Igarashi, M. Kimura, and I. Shimamura: “Positronannihilation and positronium formation: uniﬁed theory in term of a complex potential”, 23rd Int.
Conf. on Photonic Electronic and Atomic Collisions(ICPEAC 2003), Stockholm, Sweden, July (2003).
T. Nakamura, M. Wada, K. Okada, I. Katayama,
S. Ohtani, and H. A. Schuessler: “Precision spectroscopy of the zeeman splittings of the 9 Be+ 22 S1/2
hyperﬁne structure levels”, 23rd Int. Conf. on Photonic Electronic and Atomic Collisions (ICPEAC
2003), Stockholm, Sweden, July (2003).
M. Hoshino, Y. Kanai, M. Yanagisawa, Y. Nakai,
M. Kitajima, H. Tanaka, and Y. Yamazaki: “Thestate-selective angular distribution measurements ofmulti-electron caputure in X4+ (X=C, N, O)-He collisions at 50-200 eV/q”, 23rd Int. Conf. on Photonic

344

Electronic and Atomic Collisions (ICPEAC 2003),
Stockholm, Sweden, July (2003).
I. Shimamura: “Divergence of the integral cross sections for electron and positron scattering by polar
symmetric-top molecules”, Int. Symp. on ElectronMolecule Collisions and Swarms (EMS-03), (Charles
University and Academy Sciences Czech Republic),
Pruhonice, Czech, July–Aug. (2003).
I. Shimamura: “Complex potential description of
positron impact processes”, Int. Symp. on ElectronMolecule Collisions and Swarms (EMS-03), (Charles
University and Academy Sciences Czech Republic),
Pruhonice, Czech, July–Aug. (2003).
N. Ohshima, T. Kojima, M. Niigaki, K. Komaki, andY. Yamazaki: “Positron trapping with an electron
plasma under ultra high vacuum conditions”, 40th
Ann. Meet. on Radioisotopes and Radiation in the
Physical Sciences and Industries, (Japan Radioisotope Association), Tokyo, July (2003).
Y. Nagashima, F. Saito, Y. Ito, A. Goto, and T.
Hyodo: “Detection of characteristic X-rays by
positron impact”, 27th Ann. Meet. of the Soc. for
Atomic Collision Research, Kyoto, Aug. (2003).
Y. Iwai, Y. Kanai, Y. Nakai, T. Ikeda, H. Oyama, K.
Ando, H. Masuda, K. Nishio, H. Torii, K. Komaki,
and Y. Yamazaki: “High-resolution soft X-ray spectroscopy of 2.3 keV/u N6,7+ ions through microcapillary targets II”, 28th Ann. Meet. of the Soc. for
Atomic Collision Research, Hachioji, Aug. (2003).
Y. Iwai, Y. Nakai, Y. Kanai, T. Ikeda, H. Masuda, K.
Nishio, and Y. Yamazaki: “Measurement of L X-rayof highly charged Ar ions transmitted through a microcapillary target”, 28th Ann. Meet. of the Soc. for
Atomic Collision Research, Hachioji, Aug. (2003).
I. Shimamura: “Nonadiabatic transitions for theformation of unstable products: An example ofpositronium formation and annihilation”, MoscowChernogolovka Workshop on Nonadiabatic Transitions in Quantum Mechanics, (Russian ResearchCentre Kurchatov Institute and others), Moscow
and Chernogolovka, Russia, Aug. (2003).
S. Ozawa, M. Wakasugi, M. Okamura, M. Serata, T.
Koizumi, and T. Katayama: “Laser-induced ﬂuorescence spectroscopy with highly charged ion beam
produced by laser ion source”, 10th Int. Conf. on Ion
Sources (ICIS 2003), Dubna, Russia, Sept. (2003).
E. Yagi, S. Koike, T. Sugawara, T. Shishito, and K.
Ogiwara: “Change of the state of hydrogen in Nb on
alloying with Mo”, 2003 Fall Meet. of the PhysicalSoc. of Japan, Miyazaki and Okayama, Sept. (2003).
I. Shimamura: “Divergence of the integral cross sections for electron and positron scattering by polar symmetric-top molecules”, 2003 Fall Meet. of
the Physical Soc. of Japan, Miyazaki and Okayama,
Sept. (2003).
Y. Iwai, Y. Kanai, Y. Nakai, T. Ikeda, H. Oyama, K.
Ando, H. Masuda, K. Nishio, H. Torii, K. Komaki,and Y. Yamazaki: “High-resolution soft X-ray spectroscopy of 2.3 keV/u N6,7+ ions through microcapillary targets II”, 2003 Fall Meet. of the Physical Soc.
of Japan, Miyazaki and Okayama, Sept. (2003).
E. Yagi, M. Yoshii, S. Koike, H. Matsuda, Y. Okada,
K. Sakuma, K. Mori, S. Hagiwara, T. Sugawara, andT. Shishito: “Lattice location of hydrogen in NbTa alloys”, 2003 Fall Meet. of the Physical Soc. ofJapan, Miyazaki and Okayama, Sept. (2003).
M. Hoshino, T. Kambara, Y. Kanai, S. Madzunkov,
R. H. Schuch, and Y. Yamazaki: “Multi-electrontransfer in close single collisions of slow highlycharged ions with atoms”, 2003 Fall Meet. of the
Physical Soc. of Japan, Miyazaki and Okayama,
Sept. (2003).
N. Kuroda, M. Hori, H. Torii, A. Hatakeyama, N.
Oshima, Y. Morishita, A. Mohri, Y. Yamazaki, andK. Komaki: “Observation of electrostatic modes ofa mixed plasma of antiprotons and electrons”, 2003
Fall Meet. of the Physical Soc. of Japan, Miyazaki
and Okayama, Sept. (2003).
M. Wada, Y. Ishida, T. Nakamura, A. Takamine, Y.
Nakai, T. Kojima, Y. Kanai, N. Oshima, H. Oyama,
T. Kambara, A. Yoshida, T. Kubo, Y. Matsuo,
Y. Fukuyama, K. Okada, T. Sonoda, K. Noda, H.
Kawakami, S. Ohtani, I. Katayama, Y. Yamazaki,
H. Wollnik, V. Varentsov, and P. Hostein: “Slow RI
beam facility by using RF ion guide method”, 2003
Fall Meet. of the Physical Soc. of Japan, Miyazaki
and Okayama, Sept. (2003).
N. Oshima, T. Kojima, M. Niigaki, A. Mohri, K.
Komaki, and Y. Yamazaki: “Study of a positronaccumulation technique with an electron plasma”,
2003 Fall Meet. of the Physical Soc. of Japan,
Miyazaki and Okayama, Sept. (2003).
A. Takamine, M. Wada, Y. Ishida, T. Nakamura,
Y. Nakai, T. Kojima, Y. Kanai, H. Oyama, T.
Kambara, N. Oshima, A. Yoshida, T. Kubo, Y.
Matsuo, Y. Fukuyama, K. Okada, T. Sonoda,
K. Noda, H. Kawakami, S. Ohtani, I. Katayama,
Y. Yamazaki, H. Wollnik, V. Varentsov, and P.
Hostein: “The development of the system collecting energetic 8 Li ions by means of the large He gas
cell and rf ﬁeld”, 2003 Fall Meet. of the Physical Soc.
of Japan, Miyazaki and Okayama, Sept. (2003).
N. Yamanaka and Y. Kino: “Time-dependent coupled channel calculation of positron elastic scattering”, 2003 Fall Meet. of the Physical Soc. of Japan,
Miyazaki and Okayama, Sept. (2003).
N. Yamanaka, Y. Kino, Y. Takano, H. Kudo, and A.
Ichimura: “Direct positron annihilation in a densegas”, ICPA-13: 13th Int. Conf. on Positron Annihilation (KYOTO 2003), Kyoto, Sept. (2003).
N. Oshima, T. Kojima, M. Niigaki, A. Mohri, M.
Inoue, K. Komaki, and Y. Yamazaki: “Positronaccumulation eﬃciency with a combination of anelectron plasma and an ion cloud”, ICPA-13: 13th

Int. Conf. on Positron Annihilation (KYOTO 2003),
Kyoto, Sept. (2003).
Y. Yamazaki: “Antiproton-radioactive-isotope atom
formation”, Meet. of the Users Group for LowEnergy Antiproton Physics at GSI, Darmstadt, Germany, Sept. (2003).
T. Furukawa, Y. Matsuo, Y. Fukuyama, A.
Hatakeyama, T. Kobayashi, H. Izumi, Y. Arakawa,
I. Wakabayashi, K. Kawai, S. Morinobu, and T.
Shimoda: “Spin polarization and relaxation of optically pumped atoms in superﬂuid helium”, 59th
Ann. Meet. of Physical Soc. of Japan, Fukuoka, Mar.
(2004).
Y. Sakamaki, M. Hashimoto, Y. Fukai, K. Morita, J.
Yuzuhara, M. Kato, S. Koike, and E. Yagi: “Stressinduced state of hydrogen in V-H system”, 59th
Ann. Meet. of Physical Soc. of Japan, Fukuoka, Mar.
(2004).

4.

Radiochemistry, radiation chemistry, and radiation biology

Y. Kobayashi: “Valence states of 57 Fe decayed from57
Mn implanted into KMnO4 ”, RIKEN Symp. on
Condensed Matter Studies with Radioactive Ion
Beams, Wako, Feb. (2002).
T. Morishita, H. Yamaguchi, K. Degi, N. Shikazono, Y.
Hase, A. Tanaka, and T. Abe: “Dose response andmutation induction by ion beam irradiation”, 13th
Int. Conf. on Ion Beam Modiﬁcation of Materials(IBMM 2002), Kobe, Sept. (2002).
Y. Takahashi, C. Egawa, A. Hirakata, R. Hirunuma,
and S. Enomoto: “Eﬀect of surface diﬀusion on thediﬀusivity of various ions though porewater of granite”, 49th Ann. Meet. of the Geochemical Soc. ofJapan, Kagoshima, Sept. (2002).
M. Ito, Y. Takahashi, H. Mori, R. Hirunuma, S.
Enomoto, and H. Shimizu: “Experimental study
on the incorporation of Re and Os from seawater
into sediments”, 49th Ann. Meet. of the Geochemical Soc. of Japan, Kagoshima, Sept. (2002).
Y. Kanayama, S. Enomoto, and R. Amano: “Multitracer screening for RI delivery manner: Brain rubidium uptake bypassing blood-brain-barrier”, The
4th Ann. Meet./The 46th Symp. on Radiochemistry,
Sapporo, Sept. (2002).
T. Tsuji, R. Hirunuma, S. Enomoto, and R. Amano:“Radiochemical study of manganese concentrationand its uptake behavior in brain: Their changes infetal, suckling and developmental mice”, The 4th
Ann. Meet./The 46th Symp. on Radiochemistry,
Sapporo, Sept. (2002).
T. Ohyama, M. Koike, T. Ogi, Y. Kawamoto, H.
Maetsu, H. Suganuma, M. Noguchi, K. Ishikawa,
R. Hirunuma, S. Enomoto, and M. Yanaga: “Subcellular distribution of trace elements in livers ofZn-deﬁcient mice”, The 4th Ann. Meet./The 46th

345

Symp. on Radiochemistry, Sapporo, Sept. (2002).
W. Sato, H. Ueno, H. Watanabe, H. Ogawa, H.
Miyoshi, N. Imai, A. Yoshimi, K. Yoneda, D.
Kameda, Y. Kobayashi, K. Sueki, Y. Okubo, and K.
Asahi: “TDPAC studies using probes implanted in
powder C60 ”, The 4th Ann. Meet./The 46th Symp.
on Radiochemistry, Sapporo, Sept. (2002).
Y. Kanayama, T. Tsuji, S. Enomoto, and R. Amano:“Diﬀerences in delivery manner of trace elements
by some administration methods”, 6th Conf. of theInt. Soc. for Trace Element Research in Humans(ISTERH), Quebec, Canada, Sept. (2002).
T. Tsuji, T. Tarohda, Y. Kanayama, S. Enomoto, and
R. Amano: “Elemental concentration and tracer uptake distribution of manganese and other elements infetal, suckling and developmental mice”, 6th Conf.
of the Int. Soc. for Trace Element Research in Humans (ISTERH), Quebec, Canada, Sept. (2002).
T. Yanagiya, N. Imura, S. Enomoto, and S. Himeno:“Manganese can alleviate cadmium cytotoxicity”,
6th Conf. of the Int. Soc. for Trace Element Research in Humans (ISTERH), Quebec, Canada,
Sept. (2002).
S. Enomoto: “The multitracer technique: manufacturing and application to bio-trace elemental research”, 6th Conf. of the Int. Soc. for Trace Element
Research in Humans (ISTERH), Quebec, Canada,
Sept. (2002).
T. Matsuyama, T. Ebisuzaki, K. Koike, H. Kato, H.
Saito, T. Abe, and S. Yoshida: “Arabidopsis genome
analysis by the virtual RLGS system”, 11th Meet. of
the Japanese Soc. for DNA Polymorphism Research,
Asahikawa, Oct. (2002).
Y. Matsumoto, N. Umeda, H. Yin, M. Tomita, A.
Enomoto, A. Morita, T. Mizukoshi, K. Sakai, Y.
Hosoi, K. Ohtomo, and N. Suzuki: “Eﬀects of hyperthermia on DNA-PK activity and radiosensitivity”,
46th Ann. Meet. of the Japan Radiation Research
Soc., Kyoto, Oct. (2002).
T. Yanagiya, N. Imura, S. Enomoto, and S. Himeno:“Alleviation of cadmium cytotoxicity by manganese”, Int. Symp. on Bio-Trace Elements 2002
(BITREL2002): Joint Symp. of RIKEN and Yamanashi Institute of Environmental Sciences, Wako andFujiyoshida, Oct.–Nov. (2002).
R. Hirunuma and S. Enomoto: “Application of themultitracer technique: Fetoplacental transport ofvarious elements in pregnant rats”, Int. Symp. on
Bio-Trace Elements 2002 (BITREL2002): Joint
Symp. of RIKEN and Yamanashi Institute of Environmental Sciences, Wako and Fujiyoshida, Oct.–
Nov. (2002).
K. Igarashi, Y. Nakanishi, R. Hirunuma, S. Enomoto,and S. Kimura: “Biological interaction of various trace elements and NaFeEDTA as a food fortiﬁcant”, Int. Symp. on Bio-Trace Elements 2002
(BITREL2002): Joint Symp. of RIKEN and Yama-

346

nashi Institute of Environmental Sciences, Wako andFujiyoshida, Oct.–Nov. (2002).
A. Nakayama, H. Yasui, R. Hirunuma, and S.
Enomoto: “Distribution of biotrace elements inpartially hepatectomized rats”, Int. Symp. on BioTrace Elements 2002 (BITREL2002): Joint Symp. of
RIKEN and Yamanashi Institute of Environmental
Sciences, Wako and Fujiyoshida, Oct.–Nov. (2002).
T. Ohyama, M. Koike, T. Ogi, Y. Kawamoto, H.
Maetsu, H. Suganuma, M. Noguchi, K. Ishikawa, R.
Hirunuma, S. Enomoto, and M. Yanaga: “Distribution of trace elements among subcellular fractions
in livers of Zn-deﬁcient mice”, Int. Symp. on BioTrace Elements 2002 (BITREL2002): Joint Symp. of
RIKEN and Yamanashi Institute of Environmental
Sciences, Wako and Fujiyoshida, Oct.–Nov. (2002).
W. Ding, R. Hirunuma, and S. Enomoto: “Eﬀect of
insulin-enhancing action of vanadium on distribution of trace elements in the pre-diabetic stage anddiabetic stages of KK mice”, Int. Symp. on BioTrace Elements 2002 (BITREL2002): Joint Symp. of
RIKEN and Yamanashi Institute of Environmental
Sciences, Wako and Fujiyoshida, Oct.–Nov. (2002).
T. Soshi, S. Enomoto, and I. Yamaguchi: “Eﬀect
of microorganisms on the uptake of radionuclides
by plant”, Int. Symp. on Bio-Trace Elements 2002
(BITREL2002): Joint Symp. of RIKEN and Yamanashi Institute of Environmental Sciences, Wako andFujiyoshida, Oct.–Nov. (2002).
H. Yasui, T. Takino, J. Fugono, A. Nakayama, R.
Hirunuma, S. Enomoto, and H. Sakurai: “Eﬀect
of vanadium treatment on tissue distribution of
biotrace elements in normal and streptozotocininduced diabetic rats”, Int. Symp. on Bio-Trace Elements 2002 (BITREL2002): Joint Symp. of RIKEN
and Yamanashi Institute of Environmental Sciences,
Wako and Fujiyoshida, Oct.–Nov. (2002).
T. Ogi, Y. Kawamoto, H. Maetsu, M. Koike, T.
Ohyama, S. Enomoto, M. Noguchi, H. Suganuma,
and M. Yanaga: “Eﬀects of zinc content in adiet on concentrations of trace elements in organs
and tissues of mice”, Int. Symp. on Bio-Trace Elements 2002 (BITREL2002): Joint Symp. of RIKEN
and Yamanashi Institute of Environmental Sciences,
Wako and Fujiyoshida, Oct.–Nov. (2002).
T. Tsuji, R. Hirunuma, S. Enomoto, and R. Amano:“Elemental concentration and tracer uptake behavior of manganese in fetal, suckling, and developmental mice”, Int. Symp. on Bio-Trace Elements 2002
(BITREL2002): Joint Symp. of RIKEN and Yamanashi Institute of Environmental Sciences, Wako andFujiyoshida, Oct.–Nov. (2002).
T. Nabekura, T. Minami, R. Hirunuma, S. Enomoto,and Y. Ito: “Expression of metallothionein in
cataractous rat lens”, Int. Symp. on Bio-Trace Elements 2002 (BITREL2002): Joint Symp. of RIKEN
and Yamanashi Institute of Environmental Sciences,

Wako and Fujiyoshida, Oct.–Nov. (2002).
S. Enomoto: “The multitracer technology in bio-traceelements research”, Int. Symp. on Bio-Trace Elements 2002 (BITREL2002): Joint Symp. of RIKEN
and Yamanashi Institute of Environmental Sciences,
Wako and Fujiyoshida, Oct.–Nov. (2002).
H. Tamano, A. Takeda, S. Enomoto, and N. Oku:
“Zinc-65 imaging of rat brain tumors”, Int. Symp.
on Bio-Trace Elements 2002 (BITREL2002): Joint
Symp. of RIKEN and Yamanashi Institute of Environmental Sciences, Wako and Fujiyoshida, Oct.–
Nov. (2002).
K. Ushida, Y. Mizuntani, T. Kojima, Y. Yoshida, M.
Miki, T. Kozawa, and S. Tagawa: “Acetone dimer
radical cation: Reanalysis of formation dynamics”,
45th Symp. on Radiation Chemistry, Kasuga, Oct.
(2002).
T. Matsuyama, K. Koike, T. Ebisuzaki, S. Yoshida, H.
Kato, H. Saito, and T. Abe: “Arabidopsis genome
analysis by the virtual RLGS system”, 25th Ann.
Meet. of the Molecular Biology Soc. of Japan, Yokohama, Dec. (2002).
R. Hirunuma and S. Enomoto: “Application of themultitracer technique: Transport of various elements in the pregnant rats and the fetus”, Int. Symp.
on Transfer of Radionuclides in Biosphere: Prediction and Assessment, (Crossover Research Promotion Council), Mito, Dec. (2002).
H. Haba, R. Hirunuma, and S. Enomoto: “Development of a gas-jet coupled multitarget system for
multitracer production”, Int. Symp. on Transfer
of Radionuclides in Biosphere: Prediction and Assessment, (Crossover Research Promotion Council),
Mito, Dec. (2002).
T. Soshi, S. Enomoto, and I. Yamaguchi: “Eﬀect of
microorganisms on the uptake of radionuclides byplant, application of the microrganisms-plant complexsystem to the phytoremediation for radionuclides contamination”, Int. Symp. on Transfer ofRadionuclides in Biosphere: Prediction and Assessment, (Crossover Research Promotion Council),
Mito, Dec. (2002).
T. Saito, Y. Kobayashi, K. M. Kubo, and Y. Yamada:“57 CO emission Mössbauer studies of the graphite
surface”, Special Research Meet. on New Developments in Solid State Physics with Probes of Radiation and Nuclei, (Research Reactor Institute,
Kyoto University), Kumatori-cho, Osaka Pref., Dec.
(2002).
Y. Kobayashi, K. M. Kubo, Y. Yamada, T. Saito, W.
Sato, H. Ueno, J. Murata, H. Watanabe, H. Miyoshi,
D. Kameda, and K. Asahi: “Chemical states of Fe
implanted into graphite”, Special Research Meet.
on New Developments in Solid State Physics with
Probes of Radiation and Nuclei, (Research Reactor
Institute, Kyoto University), Kumatori-cho, Osaka
Pref., Dec. (2002).

M. Kibe, Y. Gounou, S. Motomura, Q. Pan, S.
Enomoto, and Y. Yano: “Characteristics of a
stripped Ge detector”, 108th Ann. Meet. of Kyusyu
Branch of The Physical Soc. of Japan, Fukuoka, Dec.
(2002).
H. Haba, K. Tsukada, M. Asai, K. Akiyama, A.
Toyoshima, I. Nishinaka, S. Ichikawa, and Y.
Nagame: “Anion exchange behavior of Nb, Ta, andPa in hydroﬂuoric acid solutions: Model experiments for chemical characterization of element 105,
dubnium”, Materials Science Symp. on Heavy Ion
Science in Tandem Energy Region, (JAERI), Tokaimura, Jan. (2003).
M. Tomita, S. Goto, F. Yatagai, and Y. Matsumoto:“A possible production of DNA clustered damage
by space radiation”, 19th Space Utilization Symp.,(The Institute of Space and Astronautical Science),
Sagamihara, Jan. (2003).
Y. Yamamoto, M. Kimura, H. Ryuto, N. Fukunishi, Y.
Yano, T. Abe, and S. Yoshida: “Multiple pathways
for light stress response of Arabidopsis thaliana”,
Keystone Symp. on Plant Response to Abiotic
Stress, Santa Fe, USA, Feb. (2003).
Y. Kobayashi: “In-beam Mössbauer spectroscopy
of Fe atoms implanted into graphite”, RIKEN
Symp. on Studies on Condensed Matter Physics,
Atomic Physics, Hyperﬁne Interactions and Biomedical Sciences Using RIKEN Accelerators, Wako, Feb.
(2003).
W. Sato, H. Ueno, H. Watanabe, H. Miyoshi, A.
Yoshimi, D. Kameda, J. Kaihara, K. Shimada, T.
Ito, S. Suda, Y. Kobayashi, and K. Asahi: “On-line
EDPAC studies using the 19 F probe (II)”, RIKEN
Symp. on Studies on Condensed Matter Physics,
Atomic Physics, Hyperﬁne Interactions and Biomedical Sciences Using RIKEN Accelerators, Wako, Feb.
(2003).
H. Haba: “Production of various radiotracers andtheir applications at the RIKEN accelerator facility”, RIKEN Symp. on Studies on Condensed Matter Physics, Atomic Physics, Hyperﬁne Interactions
and Biomedical Sciences Using RIKEN Accelerators,
Wako, Feb. (2003).
H. Haba: “Heavy element chemistry in RIKEN:
Present status and future plans”, Workshop of Advanced Science Research Center, JAERI, Nuclear
Physics and Nuclear Chemistry of Superheavy Elements, Tokai-mura, Feb. (2003).
R. Hirunuma, H. Haba, and S. Enomoto: “Development of a gas-jet coupled multitarget system and an
automatic chemical separation apparatus for multitracer production”, 123rd Ann. Meet. of the Pharmaceutical Soc. of Japan, Nagasaki, Mar. (2003).
H. Haba, K. Tsukada, M. Asai, K. Akiyama, A.
Toyoshima, I. Nishinaka, S. Ichikawa, and Y.
Nagame: “Anion exchange behavior of Nb, Ta, andPa in hydroﬂuoric acid solutions: Model experi-347

ments for chemical characterization of element 105,
dubnium”, 83rd Natl. Meet. of the Chemical Soc. ofJapan, Tokyo, Mar. (2003).
A. Toyoshima, K. Tsukada, H. Haba, M. Asai, K.
Akiyama, I. Nishinaka, S. Ichikawa, Y. Nagame,M. Shigekawa, S. Goto, T. Kaneko, S. Ono, H.
Kudo, Y. Oura, K. Sueki, M. Sakama, H. Kikunaga,
N. Kinoshita, N. Tsuruga, A. Yokoyama, and A.
Shinohara: “Anion-exchange behavior of Rf, Zr and
Hf in HF solution”, 83rd Natl. Meet. of the Chemical
Soc. of Japan, Tokyo, Mar. (2003).
Y. Kobayashi: “In-beam Mössbauer spectroscopy using RI beams”, 83rd Natl. Meet. of the Chemical
Soc. of Japan, Tokyo, Mar. (2003).
S. Enomoto: “Evolution of next-generation multitracer production technology on the RI beam factory project: Development of multitracer gammaray emission imaging and new radiopharmaceuticals”, Workshop on RI Beam Factory and ResearchPlan, (RIKEN), Wako, Mar. (2003).
Y. Kobayashi: “The applications of RI beam to materials science: In-beam Mössbauer spectroscopy”,
Workshop on RI Beam Factory and Research Plan,(RIKEN), Wako, Mar. (2003).
H. Haba, K. Tsukada, M. Asai, A. Toyoshima, K.
Akiyama, I. Nishinaka, M. Hirata, T. Yaita, S.
Ichikawa, Y. Nagame, A. Shinohara, S. Goto, T.
Kaneko, H. Kudo, Y. Oura, H. Nakahara, K. Sueki,
A. Yokoyama, M. Sakama, M. Schaedel, and J. V.
Kratz: “Chemical characterization of rutherfordiumby atom-at-a-time ion-exchange chromatography”,
6th Int. Conf. on Methods and Applications ofRadioanalytical Chemistry (MARC VI), (American
Nuclear Society), Hawaii, USA, Apr. (2003).
K. Igarashi, Y. Nakanishi, R. Hirunuma, S. Enomoto,and S. Kimura: “The eﬃcacy of NaFeEDTA for improving iron deﬁciency”, 20th Symp. on Trace Nutrients Research, Kyoto, May (2003).
M. Tomita: “Imaging analysis of heavy-ion-induced
DNA double-strand break”, RIKEN Symp. on New
Development in Radiation Biology: Molecular Imaging of the Process of DNA Damage Induction and Its
Repair, Wako, June (2003).
S. Enomoto, H. Haba, R. Hirunuma, A. Nakayama,
and K. Igarashi: “Evolution of next-generation multitracer technology: Manufacturing and application
to bio-trace elemental research”, 13th Symp. on
Roles of Metals in Biological Reactions, Biology andMedicine (SRM2003), (The Pharmaceutical Societyof Japan), Chiba, June (2003).
K. Igarashi, Y. Nakanishi, R. Hirunuma, S. Enomoto,and S. Kimura: “The eﬃcacy of NaFeEDTA asa iron fortiﬁcant”, 13th Symp. on Roles of Metals in Biological Reactions, Biology and Medicine(SRM2003), (The Pharmaceutical Society of Japan),
Chiba, June (2003).
T. Abe, Y. Miyazawa, N. Fukunishi, S. Yoshida, K.

348

Suzuki, and T. Kusumi: “A ﬂower mutant of tabacco
induced by heavy-ion beams”, Plant Biology 2003:
The Ann. Meet. of the American Soc. of Plant Biologists, Honolulu, USA, July (2003).
T. Kagawa, M. Kasahara, T. Abe, S. Yoshida, andM. Wada: “Functional analysis of Acphot2 using
mutants deﬁcient in blue light-induced chloroplast
avoidance movement of the fern Adiantum capillusveneris L”, Plant Biology 2003: The Ann. Meet.
of the American Soc. of Plant Biologists, Honolulu,
USA, July (2003).
M. Ono, H. Yokokawa, M. Matsugami, R. Amano, and
S. Enomoto: “Behavior of bio-trace elements into
the mouse brain by LPS administration”, 14th Ann.
Meet. of the Japan Soc. for Biomedical Research on
Trace Elements (JSBRTE2003), Osaka, July (2003).
K. Igarashi, R. Hirunuma, H. Haba, S. Enomoto, andS. Kimura: “Eﬀect of carnosine for the absorption ofiron and various trace elements in rats”, 14th Ann.
Meet. of the Japan Soc. for Biomedical Research on
Trace Elements (JSBRTE2003), Osaka, July (2003).
S. Enomoto, H. Haba, R. Hirunuma, K. Igarashi, A.
Nakayama, and S. Motomura: “Evolution of RI
production technology for bio-trace elemental research using RIKEN accelerator research facility”,
14th Ann. Meet. of the Japan Soc. for Biomedical
Research on Trace Elements (JSBRTE2003), Osaka,
July (2003).
Y. Kanayama, T. Yanagida, S. Toyoda, R. Amano,
and S. Enomoto: “Olfactory transport of Cs-137 byintranasal administration”, 14th Ann. Meet. of theJapan Soc. for Biomedical Research on Trace Elements (JSBRTE2003), Osaka, July (2003).
M. Honma, W. Wang, M. Sakuraba, S. Tadokoro, M.
Hayashi, M. Izumi, F. Hanaoka, and F. Yatagai:“Rapair of DNA double strand breaks in humancells induced by restriction enzyme I-SceI”, 12th Int.
Congr. of Radiation Research (ICRR 2003), (International Association for Radiation Research), Brisbane, Australia, Aug. (2003).
M. Tomita, F. Yatagai, Y. Matsumoto, N. Suzuki, andY. Hosoi: “Visualization of DNA clustered damage
induced by heavy ion exposure”, 12th Int. Congr.
of Radiation Research (ICRR 2003), (International
Association for Radiation Research), Brisbane, Australia, Aug. (2003).
Y. Matsumoto, Y. Hosoi, N. Suzuki, and M. Tomita:“XRCC4: a candidate for in vivo substrate of DNAPK”, 12th Int. Congr. of Radiation Research (ICRR
2003), (International Association for Radiation Research), Brisbane, Australia, Aug. (2003).
T. Abe, Y. Miyazawa, K. Sekino, J. Wang, and S.
Yoshida: “Heavy-ion beam mutagenesis for herbicide resistant plants”, 30th Ann. Conf. on Plant
Growth Regulation Soc. of America held jointly withThe Japanese Soc. for Chemical Regulation Plants,
Vancouver, Canada, Aug. (2003).

M. Tomita, Y. Matsumoto, Y. Hosoi, and N. Suzuki:“Heavy-ion-induced DNA damages and its repair”,
Dai4kai Monbukagakusho Tokuteiryoikikenkyu Gan
6ryoiki Wakate Workshop, Chino, Aug. (2003).
Y. Hara, T. Kitaura, T. Abe, K. Sakamoto, Y.
Miyazawa, and S. Yoshida: “Breeding of ﬂower organ mutant by heavy-ion beam radiation to buds ofrose”, 104th Ann. Congr. of the Breeding Soc. ofJapan, Kobe, Sept. (2003).
K. Suzuki, T. Takeuchi, Y. Takatsu, Y. Miyazawa, H.
Saito, T. Abe, and M. Kasumi: “Mutation breeding of spray-type Chrisanthemum I. Analysis on theshoot regeneration ability from the irradiated stem
segments”, 104th Ann. Congr. of the Breeding Soc.
of Japan, Kobe, Sept. (2003).
T. Abe: “Mutation breeding use in heavy-ion beam irradiation”, 45th Symp. in 104th Congr. of the Breeding Soc. of Japan, Kobe, Sept. (2003).
H. Yin, Y. Suzuki, Y. Matsumoto, M. Tomita, Y.
Furusawa, A. Enomoto, A. Morita, M. Aoki, F.
Yatagai, and Y. Hosoi: “Hyperthermic radiosensitization of chicken Blymphocyte DT40 and its derivatives laking NHEJ and/or HR pathways of DNA
DSB repair”, 46th Ann. Meet. of the Japan Radiation Research Soc., Kyoto, Oct. (2003).
M. Tomita, Y. Matsumoto, A. Naruto, Y. Hosoi, N.
Suzuki, and F. Yatagai: “Role of DNA-dependent
protein kinase in initial recognition of DNA doublestrand breaks”, 46th Ann. Meet. of the Japan Radiation Research Soc., Kyoto, Oct. (2003).
Y. Kobayashi, T. Okada, H. Haba, S. Jimbo, T.
Taniguchi, Y. Noro, and Y. Nagata: “99RuMössbauer spectroscopy of CaRuO3”, The 5th Ann.
Meet./The 47th Symp. on Radiochemistry, (TheJapan Society of Nuclear and Radiochemical Sciences), Izumisano, Oct. (2003).
K. Washiyama, Y. Kanayama, S. Kinuya, H. Haba, S.
Enomoto, and R. Amano: “An application of bismuth isotopes for nuclear medicine”, The 5th Ann.
Meet./The 47th Symp. on Radiochemistry, (TheJapan Society of Nuclear and Radiochemical Sciences), Izumisano, Oct. (2003).
K. Kubo, Y. Kobayashi, T. Saito, Y. Yamada, Y.
Sakai, H. Shoji, C. Yonezawa, H. Matsue, W. Sato,and M. Nakada: “Development of neutron in-beamMössbauer spectroscopy”, The 5th Ann. Meet./The
47th Symp. on Radiochemistry, (The Japan Societyof Nuclear and Radiochemical Sciences), Izumisano,Oct. (2003).
S. Enomoto, R. Hirunuma, H. Haba, K. Igarashi, andY. Yano: “Evolution of the multitracer production
technology on the RI beam factory project”, The
5th Ann. Meet./The 47th Symp. on Radiochemistry,(The Japan Society of Nuclear and Radiochemical
Sciences), Izumisano, Oct. (2003).
Y. Kanayama, T. Yanagida, R. Amano, and S.
Enomoto: “Olfactory transport of alkaline metal

ions by intranasal administration (1): Direct brain
uptake of 86Rb+ and 137Cs+ ”, The 5th Ann.
Meet./The 47th Symp. on Radiochemistry, (TheJapan Society of Nuclear and Radiochemical Sciences), Izumisano, Oct. (2003).
T. Ohyama, K. Watanabe, N. Kinugawa, M. Yanaga,
M. Noguchi, H. Suganuma, K. Ishikawa, R.
Hirunuma, K. Takahashi, and S. Enomoto: “Searching for the metal binding factor responsible for avariation of concentration of tace elements under theZn-deﬁcient condition”, The 5th Ann. Meet./The
47th Symp. on Radiochemistry, (The Japan Societyof Nuclear and Radiochemical Sciences), Izumisano,Oct. (2003).
W. Sato, H. Ueno, H. Watanabe, H. Miyoshi, A.
Yoshimi, D. Kameda, J. Kaihara, K. Shimada,T. Ito, S. Suda, Y. Kobayashi, K. Asahi, and
A. Shinohara: “c-Axis orientation dependence of
TDPAC for a single-crystalline sample”, The 5th
Ann. Meet./The 47th Symp. on Radiochemistry,(The Japan Society of Nuclear and Radiochemical
Sciences), Izumisano, Oct. (2003).
T. Abe: “Mutation breeding with using ion beam irrradiation”, 7th Workshop on HPPA Development
and Utilisation, (Korea Atomic Energy Reserach Institute), Daejeon, Korea, Oct. (2003).
T. Matsuyama, H. Saito, T. Abe, S. Yoshida, K. Koike,and T. Ebisuzaki: “Arabidopsis genome analysis
by the pattern matching system of virtual RLGS.”,
12th DNA polymorphism, Tokyo, Nov. (2003).
T. Abe, Y. Miyazawa, H. Saito, S. Yoshida, N.
Fukunishi, H. Ryuto, and Y. Yano: “Utilizationof heavy ion beams as a mutagen in plants”,
14th Symp. on Accelerator Science and Technology(SAST03), (KEK), Tsukuba, Nov. (2003).
M. Saito, H. Komori, H. Sakamoto, M. Hatashita, K.
Takagi, T. Abe, and S. Yoshida: “Mutation breeding using ion beams”, 2nd 21Seiki Rengou Symp.:
Kagakugijutsu to Ningen, Tokyo, Nov. (2003).
T. Abe, Y. Miyazawa, H. Saito, Y. Yamamoto, H.
Ryuto, and N. Fukunishi: “Mutation breeding using
ion beam irradiation”, 2nd Workshop on Application for Ion Beam Biology, (JAERI), Takasaki, Nov.
(2003).
Y. Kobayashi, T. Okada, H. Haba, T. Taniguchi,
Y. Nagata, and Y. Noro: “99Ru Mössbauer spectroscopy of CaRuO3”, Special Research Meet. on
New Developments in Solid State Physics with
Probes of Radiation and Nuclei, (Research Reactor
Institute, Kyoto Universuty), Kumatori-cho, Osaka
Pref., Nov. (2003).
T. Matsuyama, T. Ebisuzaki, K. Koike, H. Ichida, H.
Saito, T. Abe, and S. Yoshida: “Construction of thevirtual RLGS system in Arabidopsis genome analysis”, 26th Ann. Meet. of the Molecular Biology Soc.
of Japan, Kobe, Dec. (2003).
M. Tomita, Y. Matsumoto, A. Naruto, N. Suzuki, Y.

349

Hosoi, and F. Yatagai: “Imaging analysis of heavyion-induced DNA damages”, 26th Ann. Meet. of the
Molecular Biology Soc. of Japan, Kobe, Dec. (2003).
Y. Kobayashi: “Magnetism of CaRuO3 by meansof 99Ru Mössbauer spectroscopy”, RIKEN Symp.
on Studies on Condensed Matter Physics, Atomic
Physics, Nuclear Chemistry, and Biology andMedicine Using RIKEN Acccelerators, Wako, Jan.
(2004).

5. Material Analysis
A. Saeki, S. Seki, T. Sunagawa, K. Ushida, Y. Koizumi,
T. Kozawa, and S. Tagawa: “Development of microwave absorption measurement for single molecular conductivity implemented for studies of nanotechnology using accelalators”, 28th Linear Accelerator Meet. in Japan (LAM28), (JAERI), Tokaimura, July (2003).
H. Hamanaka, K. Maeda, K. Hasegawa, M. Tsuji,
and S. Murao: “Chemical state analysis of Al in
mica using a crystal spectrometer for PIXE”, 20th
PIXE Symp., (The Japan Society for Particle Induced X-ray Emission (PIXE) Research), Kouchi,
Sept. (2003).
K. Mochiki, K. Okada, T. Matsuhisa, T. Toriyama,
K. Kawasaki, K. Saneyoshi, K. Maeda, and K.
Hasegawa: “Development of an X-ray detection system for WDX-PIXE using a two-dimensional CCD”,
20th PIXE Symp., (The Japan Society for Particle
Induced X-ray Emission (PIXE) Research), Kouchi,
Sept. (2003).
K. Maeda, K. Hasegawa, M. Maeda, and H.
Hamanaka: “Extension of the feasibility of a PIXE
system using position-sensitive crystal spectrometers”, 20th PIXE Symp., (The Japan Society for
Particle Induced X-ray Emission (PIXE) Research),
Kouchi, Sept. (2003).
A. Saeki, Y. Koizumi, S. Seki, T. Kozawa, S. Tagawa,T. Sunagawa, and K. Ushida: “Development oftime-resolved microwave conductivity and light absorption spectroscopy and its application”, 46th
Symp. on Radiation Chemistry, (Japanese Societyof Radiation Chemistry), Hakone, Sept. (2003).
H. Hamanaka, K. Maeda, and K. Hasegawa: “Improvement of the precision in PIXE measurement
using a crystal spectrometer”, 22nd Symp. on Materials Science and Engineering Research Center of
Ion Beam Technology, Housei University, Koganei,
Dec. (2003).

6. RIKEN-BNL Collaboration
J. Schaﬀner-Bielich: “The role of strangeness in astrophysics”, Conf. of Strange Quarks in Matter(SQM2001), (The University of Frankfurt), Frankfurt, Germany, Sept. (2001).
K. Originos: “Flaver singlet nucleon axial charge with350

domain wall fermions”, 1st Joint Meet. of the Nuclear Physicists of the American and Japanese Physical Soc. (HAW01), (APS and JPS), Maui, USA, Oct.
(2001).
H. Abuki, T. Hatsuda, and K. Itakura: “Momentum
dependent gap in two ﬂavor color superconductivity”, 1st Joint Meet. of the Nuclear Physicists of
the American and Japanese Physical Soc. (HAW01),(APS and JPS), Maui, USA, Oct. (2001).
S. A. Bass: “Partonic reaction dynamics at RHIC”, 1st
Joint Meet. of the Nuclear Physicists of the American and Japanese Physical Soc. (HAW01), (APS and
JPS), Maui, USA, Oct. (2001).
K. Itakura, E. Iancu, and L. McLerran: “Solution to
the small-x evolution equation and saturation”, 1st
Joint Meet. of the Nuclear Physicists of the American and Japanese Physical Soc. (HAW01), (APS and
JPS), Maui, USA, Oct. (2001).
Y. Goto:“First polarized proton collisions at
PHENIX”, 10th Int. Workshop on Deep Inelastic
Scattering (DIS2002), (Institute of Nuclear Physics,
Krakow), Krakow, Poland, Apr.–May (2002).
O. Jinnouchi, K. Kurita, N. Saito, J. Tojo, H. Enyo,K. Imai, I. G. Alekseev, A. Bravar, G. Bunce, R.
Cadman, A. Deshpande, S. Dhawan, D. E. Fields,
H. Huang, V. Hughes, G. Igo, V. P. Kanavets, J.
Kiryluk, Z. Li, W. Lozowski, W. W. MacKay, Y.
Makdisi, S. Rescia, T. Roser, H. Spinka, B. Surrow,
D. N. Svirida, D. Underwood, and J. Wood: “RHIC
pC CNI polarimeter: status and performance fromthe ﬁrst collider run”, Advanced Study Institute:
Symmetries and Spin, Praha-SPIN-2002, (Charles
University), Praha, Czech, July (2002).
Y. Nagashima, F. Saito, Y. Ito, A. Goto, and T.
Hyodo: “Measurement of bremsstrahlung X ray bypositron impact”, 39th Ann. Meet. on Radioisotopes
and Radiation in the Physical Sciences and Industries, (Japan Radio Isotope Association), Tokyo,
July (2002).
Y. Goto: “Neutral pion measurements in polarized
proton collisions from PHENIX at RHIC”, 16th Int.
Conf. on Particles and Nuclei (PaNic02), (RCNP,
Osaka University), Osaka, Sept.–Oct. (2002).
H. Enyo: “Physics with RHIC spin collider”, 16th Int.
Conf. on Particles and Nuclei (PaNic02), (RCNP,
Osaka University), Osaka, Sept.–Oct. (2002).
K. Hasuko, M. Grosse-Perdekamp, A. Ogawa, J. S.
Lange, and V. Siegle: “Azimuthal asymmetries infragmentation processes at KEKB”, 15th Int. Spin
Physics Symp. (SPIN 2002), Long Island, USA,
Sept. (2002).
Y. Goto: “Prospects of the gluon polarization measurement at PHENIX”, 15th Int. Spin Physics
Symp. (SPIN 2002), Long Island, USA, Sept. (2002).
K. Okada and PHENIX Collaboration: “Single-spintransverse
asymmetry in charged hadron production√in s = 200 GeV p+p collisions at PHENIX”, 15th

Int. Spin Physics Symp. (SPIN 2002), Long Island,
USA, Sept. (2002).
K. Okada and PHENIX Collaboration: “Perfomance ofthe new EMC-RICH Level-1-Trigger in PHENIX”,
2002 Fall Meet. of the Division of Nuclear Physics
of the American Physical Soc., East Lansing, USA,
Oct. (2002).
N. Ishii: “Recent topics in lattice hadron physics”,
Asia-Paciﬁc Mini-Workshop on Lattice QCD, (Center for Computational Physics, University ofTsukuba), Tsukuba, Jan. (2003).
N. Ishii, H. Matsufuru, and H. Suganuma: “Thermal glueballs at nonzero temperature from SU(3)anisotropic lattice QCD”, Tokyo-Adelaide Joint
Workshop on Quarks, Astrophysics and Space
Physics, (University of Tokyo), Tokyo, Jan. (2003).
N. Ishii, H. Matsufuru, and H. Suganuma: “Thermal
width of glueball at non-zero temperature”, U.S.Japan Joint Workshop on Nuclear Chiral Dynamics, (Japan Society for the Promotion of Science andU.S. National Science Foundation), Honolulu, USA,
Feb. (2003).
K. Tanida: “Measurement of single transversespin asymmetry of inclusive charged particles by
PHENIX BBC in polarized pp collision at sqrt(s) =200 GeV”, 58th Ann. Meet. of Physical Soc. ofJapan, Sendai, Mar. (2003).
K. Sudo: “Nucleon spin structure in neutrino deep
inelastic scattering”, The 26th Shikoku-Seminar,(Yukawa Institute for Theoretical Physics), Takamatsu, Apr. (2003).
Y. Akiba: “Silicon vertex tracker upgrade of PHENIX
experiment at RHIC”, 8th Conf. on the Intersectionsof Particle and Nuclear Physics (CIPANP 2003),
New York, USA, May (2003).
Y. Akiba and H. Suganuma: “Experimental resultsfrom RHIC”, Int. Conf. on Color Conﬁnement andHadrons in Quantum Chromodynamics: Conﬁnement 2003, (Tokyo Institute of Technology and
RIKEN), Wako, July (2003).
M. Hirai: “∆g(x) uncertainty from prompt photon
production”, 4th Circum-Pan-Paciﬁc Symp. on HighEnergy Spin Physics (SPIN 2003), Seattle, USA,
Aug. (2003).
K. Sudo: “Single Spin Asymmetry in Inclusive D Meson Production at RHIC”, 4th Circum-Pan-Paciﬁc

Symp. on High Energy Spin Physics (SPIN 2003),
Seattle, USA, Aug. (2003).
T. Hirano: “Hydrodynamic model and hard probe”,
2003 Fall Meet. of the Physical Soc. of Japan,
Miyazaki and Okayama, Sept. (2003).
K. Sudo: “Single spin asymmetry in inclusive D meson
production at RHIC”, 2003 Fall Meet. of the Physical Soc. of Japan, Miyazaki and Okayama, Sept.
(2003).
M. Ohtani: “Vortex excitation in color ferromagnetic
phase”, 2003 Fall Meet. of the Physical Soc. ofJapan, Miyazaki and Okayama, Sept. (2003).
K. Tanida: “PHENIX upgrade”, VERTEX 2003: 12th
Int. Workshop on Vertex Detection, (Brunel University), Windermere, UK, Sept. (2003).
A. Kiyomichi and PHENIX Collaboration: “Radial
ﬂow study from
identiﬁed hadrons spectra in Au +Au collisions at sN N = 200 GeV”, 2003 Fall Meet.
of the Division of Nuclear Physics of the American
Physical Soc., Tucson, USA, Oct. (2003).
J. Tojo, K. Aoki, H. Enyo, Y. Fukao, Y. Goto, J.
Heuser, Z. Li, H. Onishi, H. Okada, V. Radeka,
V. Rykov, N. Saito, F. Sakuma, M. Sekimoto, K.
Tanida, M. Togawa, and Y. Watanabe: “Development of a novel silicon strip detector for PHICPHENIX detector upgrade”, IEEE Nuclear Science
Symp. (NSS) and Medical Imaging Conf. (MIC),
Portland, USA, Oct. (2003).
Y. Akiba: “What we have learned from RHIC”, New
Direction of Particle Physics (TEA03), (Yukawa Institute for Theoretical Physics, Kyoto University),
Kyoto, Oct. (2003).
T. Ikeda and Y. Hatta: “Quark number susceptibility
at the critical end point”, 17th Int. Conf. on UltraRelativistic Nucleus-Nucleus Collisions (Quark Matter 2004), (Lawrence Berkeley National Laboratory),
Oakland, USA, Jan. (2004).
A. Kiyomichi and PHENIX Collaboration: “Radial
ﬂow study from identiﬁed
hadron spectra in Au
+ Au collisions at sN N = 200 GeV”, 17th Int.
Conf. on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2004), Oakland, USA, Jan.
(2004).
T. Ikeda: “Memory eﬀects in kinetic equation”, 59th
Ann. Meet. of Physical Soc. of Japan, Fukuoka, Mar.
(2004).

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IX. LIST OF SYMPOSIA(Jan.–Dec. 2003)
1) Int. Workshop on Extreme Optics and Sensors
14–17 Jan., Tokyo, Image Information Div. and Materials Fabrication Lab., RIKEN and MEXT
2) The Continuum States in the Few-body Systems and the Unstable Nuclei and Their Prospects
20–22 Feb., Wako, RI Beam Science Lab., RIKEN and CNS3) Nuclear Physics at RI Beam Factory
4–5 Mar., Wako, Heavy Ion Nuclear Physics Lab., RIKEN
4) Workshop on Molecular Structure in the Region of Light Neutron-rich Nuclei to Medium Heavy Nuclei
13–15 Mar., Wako, RI Beam Science Lab., RIKEN
5) Workshop on Strategy of Nuclear Astrophysics Research
13–14 Mar., Wako, Heavy Ion Nuclear Physics Lab., RIKEN and National Astronomical Observatory, Japan6) 4th RIKEN School on QCD “Topics on the Proton”
26 Mar., Wako, Radiation Lab., RIKEN
7) Workshop on Slow RI-Beams and Related Topics
16 May, Wako, Atomic Physics Lab., RIKEN
8) Int. Workshop on Beam Cooling and Related Topics (COOL03)
19–23 May, Yamanakako, Beam Physics and Engineering Lab., RIKEN and CNS
9) New Development in Radiation Biology: Molecular Imaging of the Process of DNA Damage Induction and
Its Repair
26–27 June, Wako, Radioisotope Technology Div., RIKEN and Young Radiation Biologists’ Association inJapan10) Int. Symp. on Color Confinement and Hadrons in Quantum Chromodynamics
21–24 July, Wako, Radiation Lab., RIKEN and Tokyo Institute of Technology11) Advanced Signal Processing in Nuclear Physics
28 July, Wako, Heavy Ion Nuclear Physics Lab., RIKEN
12) RIKEN Cluster Project Workshop on Cluster Structure and Nuclear Force
27–29 Aug., Wako, RI Beam Science Lab., RIKEN
13) Spectroscopy of Unstable Nuclei and Reaction Mechanism
31 Oct.–1 Nov., Wako, Heavy Ion Nuclear Physics Lab., RIKEN
14) Collective Flow and QGP Properties
17–19 Nov., New York, USA, RBRC, RIKEN
15) Origin of Matter and Evolution of the Galaxies (OMEG03)
17–19 Nov., Wako, Heavy Ion Nuclear Physics Lab., RIKEN
16) Int. Conf. on Clustering Aspects of Nuclear Structure and Dynamics
24–29 Nov., Nara, RI Beam Science Lab., RIKEN and University of Tokyo17) High-pT Physics at RHIC
2–6 Dec., New York, USA, RBRC, RIKEN

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18) Experimental Apparatuses Being Constructed at RIBF
26 Dec., Wako, RI Beam Science Lab., RIKEN

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X. LIST OF SEMINARS(Jan.–Dec. 2003)

Radiation Lab.

RIKEN Nuclear-Physics Seminar

1) H. Abuki, University of Tokyo (Tokyo), 28 Jan.
“Color superconductivity in Schwinger-Dyson approach”

1) N. Dinh DANG, RIKEN (Wako), 18 Feb.
“Modiﬁed Hartree-Fock-Bogoliubov theory”
2) W. J. Swiatecki, LBNL (USA), 18 Mar.
“The physics of nucleus-nucleus fusion”
3) M. Takashina, RIKEN (Wako), 23 Apr.
“11 Be → 10 Be + n breakup eﬀect on 11 Be elastic
scattering”
4) C. H. Fransen, Cologne University (Germany), 14
May“Nuclear multiphonon structures with mixed
proton-neutron symmetry”
5) I. Hamamoto, University of Lund (Sweden)/NBI(Denmark), 24 July
“Shell-structure and pair-correlation in nuclei
close to the neutron drip line”
6) M. K. Gaidarov, Institute of Nuclear Researchand Nuclear Energy (Bulgaria)/Kyushu University (Fukukoka), 6 Aug.
“Nucleon-nucleon correlations and one-nucleon
removal and inclusive proton-induced reactions”
7) H. Witala, Jagellonian University (Poland), 8
Aug.
“Testing nuclear Hamiltonian with 3N hadronicand electromagnetic processes”
8) Y. M. Zhao, Southeast University (China), 30
Oct.
“Searching for the origin of spin zero groundstates of atomic nuclei”

2) T. Doi, Tokyo Institute of Technology (Tokyo), 4
Feb.
“The quark-gluon mixed condensate g<q̄σGq> inlattice QCD”
3) H. Yokoya, Hiroshima University (Higashi Hiroshima), 7 Mar.
“Lepton helicity distributions in polarized DrellYan process”
4) H. Matsufuru, Kyoto University (Kyoto), 11 Mar.
“Towards precise lattice QCD computations for
ﬂavor physics: Heavy quark on anisotropic lattice”
5) Y. Aoki, RBRC (USA), 15 Apr.
“Analyzing QCD with domain-wall fermions andan improved gauge ﬁeld on the lattice”
6) L. Frankfurt, Tel Aviv University (Israel), 30 Apr.
“Color tansparency and color opacity phenomena”
7) Y. Hatta, Kyoto University (Kyoto), 30 Apr.
“The QCD critical end-point”
8) L. Frankfurt, Tel Aviv University (Israel), 2 May“Color ﬂuctuations in lepton, hadron and nuclear
collisions”
9) J. Nagashima, Niigata University (Niigata), 20
May“Double spin asymmetries in large pT hadron production in semi-inclusive DIS”

9) M. Pfutzner, Warzawa University (Poland), 2
Dec.
“The discovery of the two-proton radioactivity”

10) Y. Koike, Niigata University (Niigata), 20 May“Single spin asymmetries in pp and ep collisions”

10) Y. Abe, YITP, Kyoto University (Kyoto), 12 Dec.
“Theoretical predictions of excitation functionsfor SHE”

11) K. Itakura, RBRC (USA), 27 May“Recent progress in the small x saturation
physics”

11) T. R. Saitoh, GSI (Germany), 22 Dec.
“Results from the RISING fast beam projects at
GSI”

12) H. Sato, KEK (Tsukuba), 27 May“Polaraized beam acceleration in the J-PARC accelerator complex”

12) A. Gelberg, Institut fur Kernphysik der Universitat zu Koln (Germany), 22 Dec.
“Gamow-Teller decay of the T = 1 nucleus 46 Cr

13) H. Kawamura, KEK (Tsukuba), 1 July
“B meson wave functions in the heavy quark
limit”

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14) K. Hasuko, RIKEN (Wako), 1 July
“Recent topics from Belle experiment”

INTEGRAL”

Applied Nuclear Physics Lab.
15) Y. Nemoto, RBRC (USA), 4 Aug.
“Pion electromagnetic form-factor with domain
wall fermions”
16) C. Sasaki, Nagoya University (Nagoya), 17 Oct.
“Vector manifestation of chiral symmetry: A newpattern for Wigner realization (with a short review on local gauge symmetry)”17) D. Drechsel, Universität Mainz (Germany), 5
Nov.
“The Gerasimov-Drell-Hearn sum rule and thenucleon spin structure in the resonance region”

1) Y. Hasegawa, Atominstitut der Oesterreichischen
Universitaeten (Austria), 17 Jan.
“Experimental test of Bell’s inequality with neutrons”

Atomic Physics Lab.
1) T. Morishita, University of Electro-Communications (Chofu), 29 Jan.
“Double ionization of He with fast proton andantiproton impacts: Theoretical treatment of ss
conﬁgulation with the hyperspherical coordinates
method”

18) G. Schnell, Tokyo Institute of Technology(Tokyo), 5 Nov.
“Measurements of generalized Gerasimov-DrellHearn integral by HERMES”

2) M. Fujiwara, RIKEN (Wako), 4 Apr.
“Production and detection of cold antihydrogenatoms”

19) O. Jinnouchi, RBRC (USA), 14 Nov.
“Polarized p-C elastic scattering in CNI region,
polarimetry at RHIC and AGS”

3) V. Varentsov, Radium Institute, St. Petersburg(Russia), 13 May“New techniques for buﬀer gas cooling and guiding of RI-beams”

20) A. Taketani, RIKEN/RBRC (Wako/USA), 14
Nov.
“Measurements of asymmetries in polarized
proton-proton collisions at RHIC”

4) V. Korobov, JINR, Dubna (Russia), 23 May“Antiprotonic helium, overview: Recent results
and future problems”

21) A. W. Thomas, Adelaide University (Australia),
9 Dec.
“Recent results in neutrino physics without oscillations”
22) L. Frankfurt, Tel Aviv University (Israel), 16 Dec.
“Ultra-peripheral collisions at LHC and RHIC”

RI Beam Science Lab.
1) Y. Motizuki, RIKEN (Wako), 11 Apr.
“How to make a good presentation in an international conference”
2) H. Sakaguchi, Kyoto University (Kyoto), 28 May“Medium eﬀects and density distributions in theintermediate energy proton elastic scattering”
3) S. Terashima, Kyoto University (Kyoto), 28 May“Neutron density distributions in Sn isotopes
deduced from the proton elastic scattering at
295 MeV”
4) R. Diehl, Max-Planck-Institut fuer Extraterrestrische (Germany), 29 Nov.
“Nucleargamma-ray
astronomywith5) J. Ullrich, Max Planck Institute fur Kernphysik(Germany), 19 June
Atoms in intense laser ﬁelds6) S. Kishimoto, KEK (Tsukuba), 3 Oct.
“Observation of NEET by synchrotron x-rays”
7) J. Sternberg, University Tennessee (USA), 7 Nov.
“Simple method for calculating three-body recombination rates in cold atoms: An adiabatic
hyperspherical approach”
8) T. Gustafsson, State University of New Jersey(USA), 10 Nov.
“Ion scattering studies of high dielectric constantmaterials”
9) L. Pichl, University of Aizu (Aizuwakamatsu), 25
Nov.
“Predissociation rates for 1 Σ+ and 3 Π states AgH
molecule”
10) M. Inokuti, Algonne National Laboratory (USA),
12 Dec.
“The charm of radiation research”

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Beam Physics and Engineering Lab.
1) M. Tamba, RIKEN (Wako), 18 Mar.
“Three dimensional ion implantation and production of DLC materials”
2) R. Jameson, LANL (USA), 25 Apr.
“RFQ design for laser ion source (LIS) 100 mA
C4+ beam”“Development and application of Compton camera: Development of multi-nuclide γ-ray emission
imaging system”
4) H. Takeichi, RIKEN (Wako), 29 May“Development and application of Compton camera: Contemporary trends and prospects in brain
research using PET and GREI”

3) I. Meshkov, JINR (Russia), 9 May“Electron cooling studies and applications at
Joint Institute for Nuclear Research”

5) T. Suzuki, Meiji Pharmaceutical University(Kiyose), 26 June
“Study of detoxiﬁcation mechanism to metals in
cisplatin resistant cell line”

4) M. Imanaka, CNS, University of Tokyo (Tokyo),
11 July“Eﬀect of magnetic ﬁeld conﬁguration on theplasma of liquid-He-free superconducting ECR
ion source”

6) T. Ishii, National Institute of Radiological Sciences (Hitachinaka), 9 Oct.
“In vivo chemical speciation of elements hyperaccumulated by marine organisms”

RIKEN BNL Research Center
5) T. Kikuchi, CNS, University of Tokyo (Tokyo), 7Aug.
“Final beam bunching for heavy ion inertial fusion”

1) Z. Xu, BNL (USA), 7 Jan.
“Characteristics of average transverse momentum
in heavy ion collisions”

6) K. Yamamoto, Tokyo Institute of Technology(Tokyo), 11 Sept.
“Study of 2 MeV/u APF-IH linac”

2) P. Kolb, Stony Brook University (USA), 17 Jan.
“Spectroscopy of resonance decays in RHIC experiments”

7) S. M. Lund, LLNL/LBNL (USA), 10 Dec.
“Bunch compression of intense heavy ion beam inrings”

3) S. Nussinov, Tel Aviv University (Israel), 22 Jan.
“Physicist’s approach to complex problems”

RIBF Project Oﬃce, Beam Dynamics Div., andBeam Tecnology Div.
1) G. Shirkov, JINR, Dubna (Russia), 19 June
“Particle in cells simulations for ion source andaccelerator”
2) G. Moritz, GSI (Germany), 17 Oct.
“Superconducting magnets for the new facility forthe rings of ions and antiprotons”

Radioisotope Technology Div.
1) S. Kojima, RIKEN (Wako), 29 May“Molecular mechanisms of various disease:
Molecular pathology of atherosclerosis, angiogenesis, and liver diseases using bioprobes”
2) A. Nakayama, RIKEN (Wako), 29 May“Molecular mechanisms of various disease: Investigation of development mechanism and new diagnostic method for chronic hepatic disorders basedon bio-trace elements and metallothionein”
3) S. Motomura, RIKEN (Wako), 29 May3564) Y. Nara, University of Arizona (USA), 24 Jan.
“Energy loss and back-to-back correlations fromhydro + jet model”
5) T. Blum, RBRC (USA), 30 Jan.
“Lattice calculation of the lowest order hadronic
contribution to the muon nomalous magnetic moment”
6) A. Accardi, Columbia University (USA), 4 Feb.
“Is the color glass condensate just glauber shadowing?”
7) J. M. Resco, Ohio State University (USA), 5 Feb.
“The electrical conductivity in hot QED”
8) P. Petreczky, BNL (USA), 7 Feb.
“Lattice calculation of the properties of hot
strongly interacting matter”
9) R. Fries, Duke University (USA), 11 Feb.
“Hadronization in heavy ion collisions”
10) C. Rebbi, Boston University (USA), 12 Feb.
“Semiclassical methods for the description of tun-neling in high-energy collisions”
11) H. Kowalski, DESY (Germany), 13 Feb.
“An impact parameter saturation model”
12) S. Weinstock, BNL (USA), 14 Feb.
“Transport equations for electroweak baryogenesis”
13) J. Ruppert, University of Frankfurt (Germany),
18 Feb.
“Chiral symmetry restoration in linear sigma
models with diﬀerent numbers of quark ﬂavors”
14) H. Neuberger, Rutgers University (Germany), 19
Feb.
“Large N reduction revisited”
15) J. Manjavidze, JINR, Dubna (Russia), 21 Feb.
“Thermalization eﬀect in hadron collisions”
16) K. Holland, UC San Diego (USA), 5 Mar.
“Lattice QCD with ﬁxed point fermions”
17) D. Zschiesche, University of Frankfurt (Germany), 11 Mar.
“Particle ratios from AGS to RHIC in an interacting hadronic model”
18) T. Baltz, BNL/RBRC (USA), 13 Mar.
“Coulomb corrections to electron positron pairs
in heavy-ion reactions”
19) I. Chiu, Columbia University (USA), 18 Mar.
“Results from photon-hadron correlations in
PHENIX”
20) D. Diakonov, NORDITA (Denmark), 19 Mar.
“Dyons in supersymmetric and ordinary YangMills theory”
21) E. Iancu, SPhT, Saclay (France), 20 Mar.
“Deep inelastic scattering oﬀ the CGC: Geometricscaling, froissart bound, and all that”
22) B. Kopeliovich, Regensburg University (Germany), 21 Mar.
“High-pT hadrons at RHIC: energy loss or absorption?”
23) D. Nomura, Durham University (UK), 26 Mar.
“The sm prediction of g-2 of the muon”
24) A. Dumitru, University of Frankfurt (Germany),
27 Mar.
“Polarized hyperons from pA collisions in the saturation regime”

25) B. L. Ioﬀe, ITEP (Russia), 1 Apr.
“Theoretical calculation of valence quark distributions in hadrons at low energy”
26) G. Moore, University of Montreal (Canada), 2
Apr.
“Transport and equilibration in ultrarelativistic
plasmas”
27) S. Jeon, McGill University (USA), 3 Apr.
“Eta-prime mesons from gluon fusion”
28) F. Zantow, University Bielefeld (Germany), 4
Apr.
“Static quark-antiquark free energy and therenormalized Polyakov loop”
29) F. Karsch, University Bielefeld (Germany), 8 Apr.
“QCD thermodynamics at non-zero baryon density”
30) D. Rainwater, DESY (Germany), 9 Apr.
“LHC Higgs news: the good, the bad, and themaybe”
31) B. Ioﬀe, ITEP (Russia), 10 Apr.
“Formation of antideuterons in heavy ion collisions”
32) M. Nardi, Turin University/INFN (Italy), 11 Apr.
“Saturation eﬀects in nuclear collisions”
33) D. Molnar, Ohio State University (USA), 15 Apr.
“Possible solution to the RHIC elliptic ﬂow puzzle”
34) I. Shovkovy, University of Frankfurt (Germany),
16 Apr.
“Color superconductivity and compact stars”
35) F. Gelis, SPhT, Saclay (France), 17 Apr.
“pA collisions in the color glass condensate
model”
36) S. Klein, LBNL (USA), 18 Apr.
“Vector meson interferometry and the EPR paradox with STAR”
37) W. Soeldner, Regensburg University (Germany),
29 Apr.
“Chiral symmetry restoration and the Z3 sectorsof QCD”
38) J. Bagger, Johns Hopkins University (USA), 8
May“TeV scale physics at a linear collider”

35739) T. Hirano, RBRC (USA), 9 May“Dynamical parton energy loss in relativistic
heavy ion collisions”
40) K. Itakura, RBRC (USA), 15 May“Gaussian eﬀective theory at small x and its application to deep inelastic scattering”
41) N. Nikolaev, Juelich (Germany), 23 May“Nonlinear kperp factorization for dijets and nuclear saturation: from DIS to nuclear collisions at
RHIC”
42) A. Vourinnen, Helsinki University (Finland), 28
May“The pressure of QCD at ﬁnite quark chemical
potential”
43) I. Vitev, Iowa State University (USA), 29 May“D+AU and Au+Au reactions at RHIC: Manifestation of multiparton dynamics in dense nuclear
matter”44) H. Kowalski, BNL/Columbia University/DESY(USA/Germany), 5 June
“An impact parameter dipole saturation model”
45) X. Wang, LBNL (USA), 19 June
“Discovery of jet quenching and beyond”46) R. Jaﬀe, MIT (USA), 11 July
“On pentaquark states”
47) D. Teaney, BNL (USA), 17 July
“Baryon number at small x”48) S. Bar-Shalom, Technion University (Israel), 30
July“Model independent analysis of Higgs Yukawa interactions via Higgs-heavy jet associated production”
49) S. Heinemeyer, University of Munich (Germany),
6 Aug.
“New results for MSSM Higgs physics at the linear collider”
50) K. Splittorﬀ, NBI (Denmark), 13 Aug.
“Elitzur’s theorem and the sign problem”
51) J. Lenaghan, University of Virginia (USA), 14
Aug.
“Instabilities in a non-equilibrium quark-gluon
plasma”
52) T. Hatsuda, University of Tokyo (Japan), 15 Aug.
“Lattice QCD study of hadrons in deconﬁned

358

plasma”
53) M. Hayakawa, RIKEN/BNL (Wako/USA), 20
Aug.
“Strong interaction eﬀect on the muon’s g-2 factor”
54) W. Roberts, Old Dominion University (USA), 21Aug.
“Aspects of pion photoproduction in the phenomenological lagrangian approach”
55) A. Stasto, DESY/Cracow (Germany/Poland), 22
Aug.
“Solution of the Balitsky-Kovchegov equation at
ﬁnite impact parameter”
56) J. Soﬀer, CPT Marseille (France), 28 Aug.
“Implications of positivity for spin physics”
57) E. Leader, Imperial College London (UK), 3 Sept.
“Can the polarization of the strange quark be positive? And why does it matter?”58) T. Kucs, YITP, Stony Brook (USA), 18 Sept.
“Beyond BFKL”
59) A. H. Hoang, “Max Plank Institute (Germany),
24 Sept.
“NRQCD and top pair production at threshold”
60) M. Braun, St. Petersburg Nuclear Physics Institute (Russia), 26 Sept.
“Nucleus-nucleus collisions in pQCD”
61) E. Shuryak, Stony Brook University (USA), 2
Oct.
“Quark-gluon plasma at critical and supercritical
coupling”
62) C. Gonzalez-Garcia, Stony Brook University(USA), 15 Oct.
“Neutrino oscillations and the sunshine”
63) Y. Nemoto, RBRC (USA), 16 Oct.
“Diquark ﬂuctuations and pseudogap in color superconductivity”
64) E. Mottola, LANL (USA), 17 Oct.
“Dark energy stars: How quantum mechanics canchange classical black holes”
65) D. Marfatia, Boston University (USA), 22 Oct.
“Physics of massive neutrinos”
66) A. Kusenko, UCLA/RBRC (USA), 23 Oct.
“Pulsar velocities, neutrinos, and dark matter”

67) G. Kribs, IAS, Princeton (USA), 29 Oct.
“Deforming supersymmetric technicolor”“Pseudorapidity distributionof charged particles√
in d+Au collisions at s N N = 200 GeV”

68) A. Starinets, University of Washington, International (USA), 4 Nov.
“String theory and kinetic coeﬃcients of YangMills plasma”

75) M. Golterman, S. F. State University (USA), 14
Nov.
“On the phase diagram of quenched QCD with
Wilson fermions”

69) R. Mohapatra, Maryland University (USA), 5
Nov.
“Neutrino mass, supersymmetry and grand uniﬁcation”76) A. Metz, Bochum University (Germany), 24 Nov.
“Universality of T-odd fragmentation functions”

70) Y. Hatta, Kyoto University/RBRC (Kyoto/USA), 6 Nov.
“Linking the chiral and deconﬁnement phasetransitions”
71) V. Guzey, Ruhr-University Bochum (Germany),
10 Nov.
“Extraction of F2 p −F2 n at small x from deuteroncollider data”
72) R. Kitano, IAS, Princeton (USA), 12 Nov.
“Higgs mediated µ-e conversion”73) A. Mueller, Columbia University (USA), 13 Nov.
“Fluctuations in high energy hard scattering in
QCD”

77) Y. Grossman, Technion/SLAC (Israel/USA), 3
Dec.
“Sleptogenesis”
78) Y. Kuramashi, KEK (Japan), 4 Dec.
“O(a) improvement for heavy quarks on the lattice”79) Y. Nomura, UC Berkeley (USA), 10 Dec.
“Grand uniﬁcation in warped space”
80) D. Soper, University of Oregon (USA), 11 Dec.
“Adding parton showers to NLO calculations”
81) K. Agashe, Johns Hopkins University (USA), 17
Dec.
“Warped compactiﬁcations: Flavor, precision
tests and grand uniﬁcation”74) R. Nouicer, BNL (USA), 14 Nov.

359

Back to Contents

XI. LIST OF PERSONNEL
Supervisor for RIKEN Accelerator Research Facility
Supervisor
Hiromichi KAMITSUBO
Deputy Supervisor
Masayasu ISHIHARA
Cyclotron Center
Director

Yasushige YANO

Accelerator-based Research Group
Director

Tohru MOTOBAYASHI

Experimental Equipment Sub-GroupSub-Group Leader
Deputy Sub-Group Leader

Masayuki KASE
Tadashi KAMBARA

LeaderGARIS
Atomic Collision ExperimentRadioisotope Production
SMART
Plant Irradiation Technology
Experimental Animal Irradiation
RIPS
Experimental Support
Computing and Networking Management
Experimental Research Sub-GroupSub-Group Leader (Non Nuclear Physics)
Deputy Sub-Group Leader (Nuclear Physics)

Kosuke MORITA
Tadashi KAMBARA
Shuichi ENOMOTO
Naruhiko SAKAMOTO
Tomoko ABE
Fumio YATAGAI
Toshiyuki KUBO
Tadashi KAMBARA
Takashi ICHIHARA

Yasunori YAMAZAKI
Koichiro ASAHI

LeaderNuclear Structure
Nuclear Reaction
Applied Nuclear Physics
Atomic Science
Animals and Cultured Cells Irradiation Research
Plant Mutation Research
Storage Ring
Analysis on Trace Elements
Detectors Development
Collaborative Research Sub-GroupSub-Group Leader
RIBF Project Group
Director
Process Management
LeaderConstruction Safety
Leader
Accelerator Sub-GroupSub-Group Leader
Deputy Sub-Group Leader

360

Tohru MOTOBAYASHI
Tohru MOTOBAYASHI
Koichiro ASAHI
Yasunori YAMAZAKI
Fumio HANAOKA
Shigeo YOSHIDA
Takeshi KATAYAMA
Yasushige YANO
Hideto EN’YO

Tohru MOTOBAYASHI

Yasushige YANO
Nobuhisa FUKUNISHI
Atsushi YAMANAKA

Akira GOTO
Nobuhisa FUKUNISHI

Leader
Project Management
Ion-source Development
RRC-system Upgrade
Frc
Irc
SRC
Cryogenics

Nobuhisa FUKUNISHI
Takahide NAKAGAWA
Osamu KAMIGAITO
Naohito INABE
Jun-ichi OHNISHI
Hiroki OKUNO
Kumio IKEGAMI

Equipment Development Sub-GroupSub-Group Leader
Deputy Sub-Group Leader

Tohru MOTOBAYASHI
Toshiyuki KUBO

LeaderCounter System Development
RIB Generator
RI Spin Probe Facility Development
SLOWRISCRITRI RingZero-degree Spectrometer
Daimajinp-RIPS
Networking and Data Processing Development
Data Acquisition Technique Development
Safety Sub-GroupSub-Group Leader

Toshimi SUDA
Toshiyuki KUBO
Koichiro ASAHI
Michiharu WADA
Masanori WAKASUGI
Tohru MOTOBAYASHI
Tohru MOTOBAYASHI
Tohru MOTOBAYASHI
Tohru MOTOBAYASHI
Takashi ICHIHARA
Yasushi WATANABE

Yoshitomo UWAMINO

Cosmic Radiation Laboratory
Head
Kazuo MAKISHIMA
Members
Hiroshi KATO
Yukikatsu TERADA
Ikuya SAKURAI∗∗

Toru TAMAGAWA
Mitsuhiro KOHAMA∗

Contract Researcher

Visiting Members
Yasushi FUKAZAWA (Dept. Phys., Hiroshima Univ.)
Tateo GOKA (JAXA)
Soojing HONG (Dept. Phys., Saitama Univ.)
Hokuto INOUE (JAXA)
Madoka KAWAHARADA (Dept. Phys., Univ. Tokyo)
Satoshi KAWASOE (Dept. Phys., Hiroshima Univ.)
Yoshihito KOBAYASHI (JAXA)
Motohide KOKUBUN (Dept. Phys., Univ. Tokyo)
Hideki KOSHIISHI (JAXA)
Jun’ichi KOTOKU (Dept. Phys., Univ. Tokyo)
Haruhisa MATSUMOTO (JAXA)
Takefumi MITANI (JAXA)
Hiromasa MIYASAKA (Univ. Delaware, Bartol Res. Inst.)
Masanori MORI (Dept. Phys., Saitama Univ.)
Mio MURAKAMI (Dept. Phys., Univ. Tokyo)
Motoki NAKAJIMA (Coll. Sci. Technol., Nihon Univ.)
Kazuhiro NAKAZAWA (JAXA)
Masanori OHNO (Dept. Phys., Hiroshima Univ.)
Yuu OKADA (Dept. Phys., Univ. Tokyo)

361

Tadayuki TAKAHASHI (JAXA)
Kazutaka YAMAOKA (Aoyama Gakuin Univ.)
Radiation Laboratory
Head
Hideto EN’YO
Members
Yasuyuki AKIBA
Yuji GOTO
Yoshie OTAKE
Kiyoshi TANIDA
Hiroaki ONISHI∗1
Junji TOJO∗1
Tatsuya CHUJO∗2Johann HEUSER∗2
Noriyoshi ISHII∗2
Akio KIYOMICHI∗2
Vladimir RYKOV∗2
Satoshi YOKKAICHI∗2∗1∗2

Takashi ICHIHARA
Masayasu OKAMURA
Atsushi TAKETANI
Yasushi WATANABE
Ryotaro MUTO∗1
Hisayuki TORII∗1
Kazumi HASUKO∗2
Masanori HIRAI∗2
Hiroyuki KANO∗2
Munehisa OTANI∗2
Kazutaka SUDO∗2

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Igor ALEKSEEV (Phys. Dept., BNL, USA)
Hiroyasu ASAMI (KEK)
Masayuki ASAKAWA (Fac. Sci., Kyoto Univ.)
Wolfgang BENTZ (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Melynda BROOKS (LANL, USA)
Muriel Jane BURWARD-HOY (Dept. Phys., State Univ. New York, Stony Brook, USA)
Gianluca COLO (Univ. Milano, Italy)
Norman CRIST (Columbia Univ., USA)
Yoshihide FUCHI (KEK)
Hirotsugu FUJII (Grad. Sch. Arts Sci., Univ. Tokyo)
Yasuyuki GONO (Fac. Sci., Kyushu Univ.)
Takashi HACHIYA (Fac. Sci., Hiroshima Univ.)
Ikuko HAMAMOTO (Lund Inst. Technol., Univ. Lund, Sweden)
Tetsuo HATSUDA (Fac. Sci., Univ. Tokyo)
Yoshitaka HATTA (Fac. Sci., Kyoto Univ.)
Naoki HAYASHI (JAERI)
Arata HAYASHIGAKI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Kensuke HOMMA (Fac. Sci., Hiroshima Univ.)
Takuma HORAGUCHI (Tokyo Inst. Technol.)Tomohiro HOTTA (Grad. Sch. Arts Sci., Univ. Tokyo)
Kenichi IMAI (Fac. Sci., Kyoto Univ.)
Michiko IMOTO (Lab. Phys., Coll. Sci. Technol., Nihon Univ.)
Genming JIN (Inst. Modern Phys., Chin. Acad. Sci., China)
Kaori KAKI (Fac. Sci., Shizuoka Univ.)
Nobuyuki KAMIHARA (Tokyo Inst. Technol.)Takeo KAWASAKI (Fac. Sci., Niigata Univ.)
Edouard KISTENEV (Phys. Dept., BNL, USA)
Yuichiro KIYO (Grad. Sch. Sci., Tohoku Univ.)
Jirou KODAIRA (Fac. Sci., Hiroshima Univ.)
Yuji KOIKE (Fac. Sci., Niigata Univ.)
Shunzo KUMANO (Fac. Sci. Eng., Saga Univ.)
Teiji KUNIHIRO (YITP, Kyoto Univ.)
Yongil KWON (Seoul Natl. Univ., Korea)
Zhong LIU (Inst. Modern Phys., Chin. Acad. Sci., China)
Earle LOMON (Massachusetts Inst. Technol., USA)362

Yajun MAO (Phys. Dept., BNL, USA)
Satoshi MATSUDA (Dept. Fund. Sci., Fac. Integr. Hum. Stud., Kyoto Univ.)
Tetsuo MATSUI (Grad. Sch. Arts Sci., Univ. Tokyo)
Yasuo MIAKE (Inst. Phys., Univ. Tsukuba)
Shoichi MIDORIKAWA (Fac. Eng., Aomori Univ.)
Toshiyuki MORII (Fac. Human Dev., Kobe Univ.)
Ludwig MUELLER (Phys. Dept., Univ. Padoba, Italy)
Tomofumi NAGAE (KEK)
Shoji NAGAMIYA (KEK)
Shogo NAKAMURA (Fac. Ed., Yokohama Natl. Univ.)
Akio OGAWA (Phys. Dept., BNL, USA)
Hiromi OKADA (Fac. Sci., Kyoto Univ.)
Kazuto OSHIMA (Gunma Natl. Coll. Technol.)
Ryutaro OOISHI (Inst. Phys., Univ. Tsukuba)
Qiangyan PAN (Inst. Modern Phys., Chin. Acad. Sci., China)
Edward PASCUZZI (Phys. Dept., BNL, USA)
Koichi SAITO (Tohoku Pharm. Univ.)
Naohito SAITO (Fac. Sci., Kyoto Univ.)
Fuminori SAKUMA (Fac. Sci., Kyoto Univ.)
Shoichi SASAKI (Fac. Sci., Univ. Tokyo)
Hikaru SATO (KEK)
Hiroki SATO (Fac. Sci., Kyoto Univ.)
Susumu SATO (Inst. Phys., Univ. Tsukuba)
Shinya SAWADA (KEK)
Markus SCHAEFER (Phys. Inst., Univ. Goettingen, Germany)
Andreas SCHAFER (Inst. Theor. Phys., Univ. Regensburg, Germany)
Wolf-Dieter SCHMIDT-OTT (Phys. Inst., Univ. Goettingen, Germany)
Bo SEDERWALL (Royal Inst. Technol., Sweden)
Michiko SEKIMOTO (KEK)Toshiaki SHIBATA (Tokyo Inst. Technol.)
Kenta SHIGAKI (KEK)
Lucian STROE (Phys. Dept., Univ. Padoba, Italy)
Toru SUGITATE (Fac. Sci., Hiroshima Univ.)
Katsuhiko SUZUKI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Tsuneo SUZUKI (Fac. Sci., Kanazawa Univ.)
Yasuhisa TAJIMA (Cycl. Radioisot. Cen., Tohoku Univ.)
Makoto TAKIZAWA (Showa Coll. Pharm. Sci.)
Manobu TANAKA (KEK)Thomas THROWE (Phys. Dept., BNL, USA)
Manabu TOGAWA (Fac. Sci., Kyoto Univ.)
Takeshi TOYAMA (KEK)
Hidenori TOYOKAWA (JASRI)
Tsuneo UEMATSU (Dept. Fund. Sci., Fac. Integr. Human Stud., Kyoto Univ.)
Masashi WAKAMATSU (Lab. Nucl. Stud., Fac. Sci., Osaka Univ.)
Tomotsugu WAKASA (RCNP, Osaka Univ.)
Sebastian WHITE (Phys. Dept., BNL, USA)
Teruya YAMANISHI (Fac. Eng., Fukui Univ. Technol.)
Yoshiki YAMASHITA (Hirosaki Univ.)
Yoshiaki YASUI (KEK)
Koichi YAZAKI (Tokyo Women’s Chr. Univ.)
Hiroshi YOKOYA (Fac. Sci. Hiroshima Univ.)
Koji YOSHIMURA (Int. Cen. Element. Part. Phys., Univ. Tokyo)
Naotaka YOSHINAGA (Fac. Sci., Saitama Univ.)
Masaru YOSOI (Fac. Sci., Kyoto Univ.)
Lihua ZHU (China Inst. Atom. Energy, China)
Trainees
Kazuya AOKI (Fac. Sci., Kyoto Univ.)
Hisato EGUCHI (Fac. Sci., Niigata Univ.)
Kouhei FUJIWARA (Fac. Sci., Niigata Univ.)363

Koichi HASHIMOTO (Fac. Sci., Kanazawa Univ.)
Hiroki KANO (Tokyo Inst. Technol.)
Masahiro KONNO (Inst. Phys., Univ. Tsukuba)
Kentarou MAWATARI (Fac. Hum. Dev., Kobe Univ.)
Takahiro NAGAI (Fac. Sci. Eng., Saga Univ.)
Junji NAGASHIMA (Fac. Sci., Niigata Univ.)
Tomoaki NAKAMURA (Fac. Sci., Hiroshima Univ.)
Kenichi NAKANO (Tokyo Inst. Technol.)Maya SHIMOMURA (Inst. Phys., Univ. Tsukuba)
Kohei SHOJI (Fac. Sci., Kyoto Univ.)
Noriyuki SUGITA (Fac. Sci., Hiroshima Univ.)
Satoshi TAKAGI (Inst. Phys., Univ. Tsukuba)
Junpei TAKANO (Tokyo Inst. Technol.)Takashi WATANABE (Tokyo Inst. Technol.)
Choong-Jae YOON (Fac. Sci., Kyoto Univ.)
RI Beam Science Laboratory
Head
Tohru MOTOBAYASHIMembers
Alexei A. KORSHENINNIKOV
Toshimi SUDA
Koichi YOSHIDA
Kouji MORIMOTO
Eiji IDEGUCHI
Yoshimitsu FUKUYAMA∗1
Masaaki KIMURA∗1
Mizuki NISHIMURA∗1
Noritaka SHIMIZU∗1
Deging FANG∗2
Yoshihisa ISHIDA∗2
Kensuke KUSAKA∗2
Toshimitsu YAMAZAKI∗2∗1∗2

Yukari MATSUO
Atsushi YOSHIDA
Akira OZAWA
Shunji NISHIMURA
Akihisa KOHAMAKei IIDA∗1
Yuji NISHI∗1
Tetsuya OHNISHI∗1
Satoshi SUGIMOTO∗1
Kiyomi IKEDA∗2
Rituparna KANUNGO∗2
Yuko MOTIZUKI∗2

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Yasuhisa ABE (Yukawa Inst. Theor. Phys., Kyoto Univ.)
Yasuo AOKI (Fac. Sci., Univ. Tsukuba)
Shigeyoshi AOYAMA (Kitami Inst. Technol.)
Yoshihiro ARITOMO (JINR, Russia)
Richard BOYD (Ohio Univ., USA)Roﬀ BROCKMANN (Inst. Phys., Univ. Mainz., Germany)
Antonio CASARES (Oak Ridge Lab., USA)
Masami CHIBA (Fac. Sci., Tohoku Univ.)
Llie CRUCCERU (Horia Inst. Eng., Romania)
Vivek DATAR (Bhabha Atom. Res. Cen., India)
Dean J. DAVID (CALTEC, USA)
Alla S. DEMIYANOVA (Kurchatov Inst. Atom. Energy, Russia)
Tadayoshi DOKE (Sci. Eng. Res Lab., Waseda Univ.)
Yoshiko ENYO (KEK)
Michael FAMIANO (Ohio Univ., USA)
Andrei FOMITCHEV (JNRF, Russia)
Takaaki FUKUOKA (Taisho Univ.)
Mamoru FUJIWARA (RCNP, Osaka Univ.)
Zsolt FÜLÖP (ATOMKI, Hungary)
Zoltan GACSI (ATOMKI, Hungary)
Yu-Cheng GE (Peking Univ., China)364

Hans GEISSEL (GSI, Germany)
Mircea GIURGIU (Inst. Phys. Nucl. Eng., Romania)
Mikheil S. GOLOVKOV (Kurchatov Inst., Russia)
Sergei A. GONCHAROV (Kurchatov Inst., Russia)
Stephanoe GORIELY (Inst. Astron., Belgium)
Alexander GORINE (IHEO, Russia)
Ranjana GOSWAMI (Variable Energy Cycl. Cen. Calcutta, India)
Syuichi GUNJI (Yamagata Univ.)
Zhenhui HAN (Fudan Univ., China)
Toru HARADA (Fac. Sci. Inf., Sapporo Gakuen Univ.)
Nobuyuki HASEBE (Sci. Eng. Res. Lab., Waseda Univ.)
Jun HASEGAWA (Fac. Eng., Tokyo Inst. Technol.)Michio HATANO (Fac. Sci., Univ. Tokyo.)Nguyen Thuc HIEN (Hanoi Univ., Vietnam)
Satoru HIRENZAKI (Fac. Sci., Nara Women’s Univ.)
Michio HONMA (Univ. Aizu)
Takatoshi HORIBATA (Fac. Sci., Aomori Univ.)
Shen HONG (Dept. Phys., Nankai Univ.)
Masakatu HORIGUCHI (Horiguchi Ironworks)
Hisashi HORIUCHI (Fac. Sci., Kyoto Univ.)
Akitsu IKEDA (Shizuoka Inst. Sci. Technol.)
Shigeru ISHIMOTO (KEK)
Naoyuki ITAGAKI (Fac. Sci., Univ. Tokyo)
Makoto ITO (Fac. Sci., Univ. Tsukuba)
Akira IWAMOTO (JAERI)
Naohisa IWASA (Fac. Sci., Tohoku Univ.)
Takuji IZUMIKAWA (Fac. Sci., Niigata Univ.)
Takeo IZUYAMA (Fac. Sci., Toho Univ.)
Dang-Xing JIANG (Peking Univ., China)
Masayasu KAMIMURA (Fac. Sci., Kyushu Univ.)
Toshiki KAJINO (Natl. Astron. Obs.)
Kiyoshi KATO (Fac. Sci., Hokkaido Univ.)
Jun KIKUCHI (Sci. Eng. Res. Lab., Waseda Univ.)
Kikuo KIMURA (Fac. Sci., Nagasaki Inst. Appl. Sci.)
Syunichi KITAHARA (Jumonji Women’s Univ.)
Masanori KOBAYASHI (Sci. Eng. Res. Lab., Waseda Univ.)
Toshio KOBAYASHI (Fac. Sci., Tohoku Univ.)
Tetsuro KOMATSUBARA (Univ. Tsukuba)
Hiroyuki KOURA (Fac. Sci. Eng., Waseda Univ.)
Evgueni KOUZMINE (Kurchatov Inst., Russia)
Attila KRASZNAHORKAY (ATOMKI, Hungary)
Hidekazu KUMAGAI
Suresh KUMARU (Bhabha Atom. Res. Cen., India)
Khiem LE HONG (Inst. Phys., Natl. Cen. Sci. Technol., Vietnam)
Xing-Qing LI (Peking Univ., China)
Zhi-Huan LI (Peking Univ., China)
Hongfeng LU (Peking Univ., China)
Takahiro MIZUSAKI (Fac. Sci., Univ. Tokyo)
Koichi MARUYAMA (Kitazato Univ.)
Tomoyuki MARUYAMA (Nihon Univ.)
Toshiki MARUYAMA (JAERI)
Nobuyuki MATSUOKA (RCNP, Osaka Univ.)
Kensaku MATSUTA (Fac. Sci., Osaka Univ.)
Yoshitaka MATSUYAMA (Inst. Nucl. Stud., Univ. Tokyo)
Kenichi MATSUYANAGI (Grad. Sch. Sci., Kyoto Univ.)
Masayuki MATSUZAKI (Fac. Ed., Fukuoka Univ.)
Jie MENG (Peking Univ., China)
Souichi MIDORIKAWA (Fac. Eng., Aomori Univ.)
Kei MINAMISONO (Fac. Sci., Osaka Univ.)
Tadanori MINAMISONO (Fac. Sci., Osaka Univ.)365

Wolfgang MITTING (GANIL, France)
Mototugu MIHARA (Fac. Sci., Osaka Univ.)
Tanu Ekanath MIRGULE (Bhabha Atom. Res. Cen., India)
Takashi MIYACHI (Fac. Sci. Eng., Waseda Univ.)
Yasuo MIYAKE (Fac. Sci., Univ. Tsukuba)
Osamu MIYAMURA (Fac. Sci., Hiroshima Univ.)
Sadao MOMOTA (Kochi Univ. Technol.)Hiroaki MORITA (Horiguchi Ironworks)
Mitsuo MURAOKA (Fac. Sci., Aomori Univ.)
Atsushi MUTA (Inst. Phys., Univ. Tsukuba)
Kazuo MUTO (Inst. Sci., Chiba Univ.)
Hitoshi NAKADA (Fac. Sci., Chiba Univ.)
Takashi NAKATSUKASA (Fac. Sci., Tohoku Univ.)
Yoichi NOJIRI (Kochi Univ. Technol.)Izumi NOMURA (Natl. Inst. Fusion Sci.)
Kengo OGAWA (Coll. Arts Sci., Chiba Univ.)
Masao OGAWA (Fac. Eng., Tokyo Inst. Technol.)
Yoko OGAWA (Fac. Sci., Osaka Univ.)
Alexei A. OGLOBLIN (Kurchatov Inst., Russia)
Akira OHNISHI (Fac. Sci., Hokkaido Univ.)
Naoki OHNISHI (Fac. Eng., Yamanashi Univ.)
Masahisa OHTA (Fac. Sci., Konan Univ.)
Hideaki OHTSU (Fac. Sci., Tohoku Univ.)
Takashi OHTSUBO (Fac. Sci., Niigata Univ.)
Narito OKABE (Fac. Sci., Hokkaido Univ.)
Hiroyuki OKADA (Sci. Eng. Res. Lab., Waseda Univ.)
Osamu OKUDAIRA (Fac. Sci. Eng., Waseda Univ.)
Kazuo OMATA (Inst. Nucl. Stud., Univ. Tokyo)
Akira ONO (Fac. Sci., Tohoku Univ.)
Makito OOI (Dept. Phys., Sch. Sci., Univ. Tokyo)
Shinsho ORYU (Fac. Sci. Technol., Tokyo Univ. Sci.)
Takaharu OTSUKA (Fac. Sci., Univ. Tokyo)
Diane REITZNER (Ohio Univ., USA)
Kazuhiro OYAMATSU (Aichi Shukutoku Univ.)
Emmanuel ROLACCO (EAC, France)
Zhou Zhang REN (Nanjing Univ., China)
Chamanz P. ROUSSEL (GANIL, France)
Hiroyuki SAGAWA (Univ. Aizu)
Harutaka SAKAGUCHI (Grad. Sch., Kyoto Univ.)
Hideyuki SAKAI (Fac. Sci., Univ. Tokyo)
Hirohisa SAKURAI (Yamagata Univ.)
Chhanda SAMANTA (Sala Inst. Nucl. Phys., Calcutta, India)
Badawy SARHAN (Cairo Univ., Egypt)
Hiromasa SASA (Horiguchi Ironworks)
Kimikazu SASA (Univ. Tsukuba)
Kenichi SATO (Dept. Phys., Tohoku Coll. Pharm)
Lee S. SCHROEDER (Laurence Berkeley Lab., USA)
Ryoichi SEKI (California Univ., USA)
Milena SERRA (Tech. Munich Univ., Germany)
Bradley M. SHERRIL (Michigan State Univ., USA)
Caiwan SHEN (Dept. Nucl. Phys., China Inst. At. Energy, China)
Michihiro SHIBATA (Nagoya Univ.)
Toru SHIBATA (Sci. Eng., Aoyama Gakuin Univ.)
Cosimo SIGNORINI (INEN, Italy)
Mickael SMITH (Inst. Oak Ridge, USA)
Koonin STEVEN (CALTEC, USA)
Masahiko SUGAWARA (Fund. Sci., Chiba Inst. Technol.)
Kohsuke SUMIYOSHI (Numazu Coll. Technol.)Summerer KLAUS (GSI, Germany)
Akihiro SUZUKI (Shinshu Univ.)366

Hideyuki SUZUKI (KEK)
Takeshi SUZUKI (Fac. Sci., Saitama Univ.)
Tsuneo SUZUKI (Fac. Sci., Kanazawa Univ.)
Toshio SUZUKI (Coll. Hum. Sci., Nihon Univ.)
Toshio SUZUKI (Fukui Univ.)
Yasuyuki SUZUKI (Fac. Sci., Niigata Univ.)
Takahiro TACHIBANA (Sen. High Sch., Waseda Univ.)
Koji TAKAHASHI (Inst. Max Plank, Germany)
Yutaka TAKAHASHI (RCNP, Osaka Univ.)
Masatoshi TAKANO (Sci. Eng. Res. Lab., Waseda Univ.)
Tadashi TAKEMASA (Kyoto Univ. Ed.)
Noboru TAKIGAWA (Fac. Sci., Tohoku Univ.)
Naoki TAJIMA (Fac. Sci., Fukui Univ.)
Kazuko TANABE (Otsuma Women’s Univ.)
Kazuhiro TANAKA (Med. Dept., Juntendo Univ.)
Takaya TANAKA (Fac. Sci., Saitama Univ.)
Kazuhiro TERASAWA (Fac. Sci. Eng., Waseda Univ.)
Hirokazu TEZUKA (Dept. Liberal Arts., Fac. Literature, Toyo Univ.)
Peter SHIROLF (Univ. Munich, Germany)
Mitsuru TOHYAMA (Kyorin Univ.)
Fuyuki TOKANAI (Fac. Sci., Yamagata Univ.)
Hiroshi TOKI (RCNP, Osaka Univ.)
Toshiaki TOMODA (Fac. Sci., Aomori Univ.)
Baeck TORBJOEN (Phys. Dept. Frescat., Sweden)
Jeﬀrey A. TOSTEVIN (Univ. Surry, India)
Yukio UCHIBORI (NIRS)
Yutaka UTSUNO (Tokai Res. Estab., JAERI)
Hiroaki UTSUNOMIYA (Fac. Sci., Konan Univ.)
Kalman VARGA (Inst. Oak Ridge, USA)
Takahiro WADA (Fac. Sci., Konan Univ.)
Masamiti WAKAI (Grad. Sch. Sci., Osaka Univ.)
Quanjin WANG (Peking Univ., China)
Martin WINKLER (GSI, Germany)
Cuie WU (Peking Univ., China)
Herman WOLLNIK (Oak Ridge. Lab., USA)
Kazuhiro YABANA (Fac. Sci., Univ. Tsukuba)
Hirosuke YAGI (Fac. Sci., Univ. Tsukuba)
Kazunari YAMADA (Fac. Sci., Rikkyo Univ.)
Syoichi YAMADA (Fac. Sci., Univ. Tokyo)
Takayuki YAMAGUCHI (Fac. Sci., Univ. Saitama)
Yoshitaka YAMAGUCHI (Fac. Sci., Niigata Univ.)
Yoshio YAMAGUCHI (Inst. Nucl. Stud., Univ. Tokyo)
Yanlin YE (Peking Univ., China)
Alhassid YORANN (Yale Univ., USA)
Nobuaki YOSHIDA (Fac. Inf., Konan Univ.)
Naotaka YOSHINAGA (Fac. Sci., Saitama Univ.)
Akira YUNOKI (Toshiba Co.)
Tao ZHENG (Peking Univ., China)
Shan-Gi ZHOU (Peking Univ., China)
Trainees
Youhei ARAKAWA (Fac. Sci., Osaka Univ.)
Masayuki ASAEDA (Fac. Sci. Eng., Waseda Univ.)
Cholsong CHONG (Fac. Sci. Eng., Waseda Univ.)
Hiroki FUJIWARA (Fac. Sci., Osaka Univ.)
Yasuro FUNAKI (Fac. Sci., Kyoto Univ.)
Takeshi FURUKAWA (Fac. Sci., Osaka Univ.)
Naoki FUKUDA (Fac. Sci. Eng., Waseda Univ.)
Tetsuhito FUSE (Fac. Sci. Eng., Waseda Univ.)
Izumi HASHIMOTO (Fac. Sci., Osaka Univ.)367

Kazuaki HASHIZUME (Fac. Sci., Konan Univ.)
Masamichi HARUKI (Fac. Sci. Eng., Waseda Univ.)
Masaru HIBINO (Fac. Sci. Eng., Waseda Univ.)
Hiroshi HIGASHI (Fac. Sci. Eng., Waseda Univ.)
Takuji HIRAMOTO (Fac. Sci. Eng., Waseda Univ.)
Takehiro HOSOJIMA (Fac. Sci. Eng., Waseda Univ.)
Tsutomu IGARASHI (Fac. Sci. Eng., Waseda Univ.)
Akifumi IHARA (Fac. Sci. Eng., Waseda Univ.)
Rinzo IIO (Fac. Sci. Eng., Waseda Univ.)
Hiroshi ITO (Fac. Sci. Eng., Waseda Univ.)
Tomomi KATO (Fac. Sci., Niigata Univ.)
Nobuhiro KAJIWARA (Fac. Sci. Eng., Waseda Univ.)
Yoshie KAWAMURA (Fac. Sci., Niigata Univ.)
Eiichi KIHIRA (Fac. Sci. Eng., Waseda Univ.)
Atushi KIYAMU (Ibaraki Univ.)
Shingo KOBAYASHI (Fac. Sci. Eng., Waseda Univ.)
Satoshi KODAIRA (Fac. Sci. Eng., Waseda Univ.)
Takayuki KOIKE (Fac. Sci. Eng., Waseda Univ.)
Ryo KOYAMA (Fac. Sci., Niigata Univ.)
Shinichi KUMASHIRO (Fac. Sci., Osaka Univ.)
Genei KURAZA (Fac. Sci. Eng., Waseda Univ.)
Yohei MATSUDA (Fac. Sci., Tohoku Univ.)
Makoto MATSUNAGA (Fac. Sci. Eng., Waseda Univ.)
Takahiro MASUMURA (Fac. Sci. Eng., Waseda Univ.)
Howard MEREDITH (Ohio Univ., USA)
Daisuke MIKI (Fac. Sci. Eng., Waseda Univ.)
Toshiya MIKI (Fac. Sci., Tohoku Univ.)
Mitsuteru MIMURA (Fac. Sci. Eng., Waseda Univ.)
Satoshi MURASAWA (Fac. Sci. Eng., Waseda Univ.)
Atsushi NAGASHIMA (Fac. Sci. Eng., Waseda Univ.)
Takashi NAGATOMO (Fac. Sci., Osaka Univ.)
Yoshiki NAKASHIMA (Fac. Sci., Osaka Univ.)
Yusuke NAKAMURA (Fac. Sci. Eng., Waseda Univ.)
Fumihiko NISHIKIDO (Fac. Sci. Eng., Waseda Univ.)
Takashi OKUDA (Fac. Sci., Tohoku Univ.)
Masako OGURA (Fac. Sci., Osaka Univ.)
Kazuki OHZEKI (Fac. Sci., Tohoku Univ.)
Akihiro OKA (Fac. Sci. Eng., Waseda Univ.)
Takashi OKUDA (Fac. Sci., Tohoku Univ.)
Osamu OKUDAIRA (Fac. Sci. Eng., Waseda Univ.)
Kiminori OZAKI (Fac. Sci. Eng., Waseda Univ.)
Hisanori SAKABA (Fac. Sci. Eng., Waseda Univ.)
Takao SAKAGUCHI (Fac. Sci. Eng., Waseda Univ.)
Makoto SASAKI (Fac. Sci., Osaka Univ.)
Kazunori SATO (Fac. Sci., Niigata Univ.)
Yoko SEKI (Fac. Sci., Tohoku Univ.)
Masatugu SEKIGUCHI (Fac. Sci., Tohoku Univ.)
Atsuhito SHIINA (Fac. Sci. Eng., Waseda Univ.)
Noritaka SHIMIZU (Fac. Sci., Univ. Tokyo)
Tokukazu SHINOHARA (Fac. Sci., Tohoku Univ.)
Wakako SHINOZAKI (Fac. Sci. Niigata Univ.)
Hirofumi SOURI (Fac. Sci. Eng., Waseda Univ.)
Edward SMITH (Ohio Univ., USA)
Masa TAKAHASHI (Fac. Sci., Niigata Univ.)
Atsushi TAKEMURA (Fac. Sci., Osaka Univ.)
Haruyuki TAKEMURA (Fac. Sci. Eng., Waseda Univ.)
Sunao TAKENAKA (Fac. Sci. Eng., Waseda Univ.)
Masatoshi TAKENOUCHI (Fac. Sci. Eng., Waseda Univ.)
Motoyuki TANAKA (Fac. Sci. Eng., Waseda Univ.)
Shinya TAZAWA (Fac. Sci., Tohoku Univ.)368

Kazuhiro TERASAWA (Fac. Sci. Eng., Waseda Univ.)
Satoru TERASAWA (Fac. Sci., Kyoto Univ.)
Mariko TERASAWA (Natl. Astron. Obs.)
Shigeru TERUHI (Fac. Sci. Eng., Waseda Univ.)
Chikara TEZUKA (Fac. Sci. Eng., Waseda Univ.)
Toru UZIIE (Fac. Sci., Tohoku Univ.)
Kiwamu WATANABE (Fac. Sci., Tohoku Univ.)
Shigeo WATANABE (Fac. Sci., Niigata Univ.)
Takashi YAKUSHIJI (Fac. Sci., Tohoku Univ.)
Hiroyuki YAMAMOTO (Fac. Sci. Eng., Waseda Univ.)
Masaki YAMASHITA (Fac. Sci. Eng., Waseda Univ.)
Naoyuki YAMASHITA (Fac. Sci. Eng., Waseda Univ.)
Junichi YASHIRO (Fac. Sci. Eng., Waseda Univ.)
Jun YASUTANI (Fac. Sci. Eng., Waseda Univ.)
Eriko YOKOYAMA (Fac. Sci. Eng., Waseda Univ.)
Hideki YOSHIOKA (Fac. Sci. Eng., Waseda Univ.)
Applied Nuclear Physics Laboratory
Head
Koichiro ASAHI
Members
Yoshio KOBAYASHI
Akihiro YOSHIMI
Hiroshi WATANABE∗2∗1∗2

Hideki UENO
Tomohito HASEYAMA∗1

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Minoru ADACHIYasuaki EINAGA (Fac. Sci. Eng., Keio Univ.)
Hideaki IZUMI (Grad. Sch. Sci. Eng., Osaka Univ.)
Kenya M. KUBO (Div. Natl. Sci., Int. Chr. Univ.)
Hisanori MIYOSHI (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)
Jiro MURATA (Fac. Sci., Rikkyo Univ.)
Yujiro NAGATA (Coll. Sci. Technol., Aoyama Gakuin Univ.)
Hiromichi NAKAHARA (Grad. Sch. Sci., Tokyo Metrop. Univ.)
Jin NAKAMURA (Dept. Appl. Phys. Chem., Univ. Electro-Commun.)
Saburo NASU (Grad. Sch. Eng. Sci., Osaka Univ.)
Hiroshi OGAWA (Natl. Inst. Adv. Ind. Sci. Technol.)
Takuya OKADA (Fac. Sci., Gakushuin Univ.)
Hiroyuki SAGAWA (Math. Sci., Univ. Aizu)
Wataru SATO (Grad. Sch. Sci., Osaka Univ.)
Kenji SAKAI (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)Kenji SHIMADA (Fac. Sci., Tokyo Inst. Technol.)Tadashi SHIMODA (Grad. Sch. Sci. Eng., Osaka Univ.)
Takashi TANIGUCHI (Coll. Sci. Technol., Aoyama Gakuin Univ.)
Masahiko UTSURO (RCNP, Osaka Univ.)
Yasuhiro YAMADA (Fac. Sci., Tokyo Univ. Sci.)
Eiichi YAGI (Sch. Sci. Eng., Waseda Univ.)
Yutaka YOSHIDA (Fac. Sci. Technol., Shizuoka Inst. Sci. Technol.)Trainees
Syoken EMORI (Fac. Sci., Tokyo Inst. Technol.)Shinya FUKAGAI (Sch. Sci. Eng., Waseda Univ.)
Shinichi HAGIWARA (Sch. Sci. Eng., Waseda Univ.)
Tatsuya HAYASHI (Sch. Sci. Eng., Waseda Univ.)
Naota HIGAMI (Sch. Sci. Eng., Waseda Univ.)369

Takashi ITO (Fac. Sci., Tokyo Inst. Technol.)Shimon JINBO (Coll. Sci. Technol., Aoyama Gakuin Univ.)
Daisuke KAMEDA (Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)Jou KAIHARA (Fac. Sci., Tokyo Inst. Technol.)Gou KATO (Fac. Sci., Tokyo Inst. Technol.)Gou KIJIMA (Fac. Sci., Tokyo Inst. Technol.)
Takaki KOIKE (Fac. Sci., Tokyo Inst. Technol.)
Akira KUMAKURA (Fac. Sci., Tokyo Univ. Sci.)
Hiroshi MATSUBA (Sch. Sci. Eng., Waseda Univ.)
Kazuya MIYAHARA (Sch. Sci. Eng., Waseda Univ.)
Jun MIYAZAKI (Grad. Sci., Tokyo Univ. Sci.)
Katsuhito MORI (Sch. Sci. Eng., Waseda Univ.)
Tetsuya NAKAGAWA (Fac. Sci., Tokyo Univ. Sci.)
Yuki NEMOTO (Fac. Sci., Tokyo Univ. Sci.)
Yoshinori OKADA (Sch. Sci. Eng., Waseda Univ.)
Takahiro OHTSUKA (Div. Natl. Sci., Int. Chr. Univ)
Atsushi SAITO (Fac. Sci., Tokyo Univ. Sci.)
Takashi SAITO (Fac. Sci., Tokyo Univ. Sci.)
Kiwamu SAKUMA (Sch. Sci. Eng., Waseda Univ.)
Jyunko SUDA (Div. Natl. Sci., Int. Chr. Univ.)
Shinichi SUDA (Fac. Sci., Tokyo Inst. Technol.)
Chika SUGI (Sch. Sci. Eng., Waseda Univ.)
Masato TSUKUI (Fac. Sci., Tokyo Inst. Technol.)Motoyasu YOSHII (Sch. Sci. Eng., Waseda Univ.)
Atomic Physics Laboratory
Head
Yasunori YAMAZAKI
Members
Tadashi KAMBARA
Hitoshi OYAMA
Takao M. KOJIMA
Takane KOBAYASHI
Masaki OURA
Nobuhiro YAMANAKA∗∗

Yasuyuki KANAI
Michiharu WADA
Yoichi NAKAI
Tokihiro IKEDA
Yoshio IWAI∗
Makoto C. FUJIWARA∗

Special Postdoctoral Researcher

Visiting Members
Kozo ANDO
Takeo ARUGA (Tokai Res. Estab., JAERI)
Yohko AWAYA (Coll. Art Design Gen. Ed., Musashino Art Univ.)
Toshiyuki AZUMA (Dept. Phys., Tokyo Metrop. Univ.)
Joachim BURGDÖRFER (Vienna Univ. Technol., Austria)
Li CHEN (LASIM, Lyon Univ., France)
Yasuhiro CHIMI (Tokai Res. Estab., JAERI)
Atsushi HATAKEYAMA (Grad. Sch. Arts Sci., Univ. Tokyo)
Hiroyuki HIGAKI (Inst. Appl. Phys., Univ. Tsukuba)
Akira HITACHI (Kochi Med. Sch.)
Jiri HORACEK (Charles Univ., Czech)
Masamitsu HOSHINO (Grad. Sch. Sci. Eng., Sophia Univ.)
Roger HUTTON (Dept. Phys., Univ. Lund, Sweden)
Atsushi ICHIMURA (Inst. Space Astro. Sci.)
Akinori IGARASHI (Fac. Eng., Miyazaki Univ.)
Mitio INOKUTI (Argonne Natl. Lab., USA)
Keishi ISHII (Fac. Sci. Eng., Ritsumeikan Univ.)
Norito ISHIKAWA (Tokai Res. Estab., JAERI)
Akio ITOH (Fac. Eng., Kyoto Univ.)
Yoh ITOH (Fac. Sci., Josai Univ.)370

Akihiro IWASE (Res. Inst. Adv. Sci. Tech., Osaka Prefec. Univ.)
Kensuke KAGEYAMA (Fac. Eng., Saitama Univ.)
Kenji KIMURA (Fac. Eng., Kyoto Univ.)
Mineo KIMURA (Fac. Eng., Yamaguchi Univ.)
Masashi KITAJIMA (Fac. Sci. Tech., Sophia Univ.)
Nobuo KOBAYASHI (Dept. Phys., Tokyo Metrop. Univ.)
Tetsuo KOIZUMI (Dept. Phys., Rikkyo Univ.)
Ken-ichiro KOMAKI (Grad. Sch. Arts Sci., Univ. Tokyo)
Kenichi KOWARI (Dept. Appl. Phys. Chem., Univ. Electro-Commun.)
Kenro KUROKI (Natl. Res. Inst. Police Sci.)
Michio MATSUZAWA (Dept. Appl. Phys. Chem., Univ. Electro-Commun.)
Koichiro MITSUKE (Inst. Mol. Sci.)
Akihiro MOHRI
Yuichiro MORISHITA (Electrotechnical Lab.)
Takeshi MUKOYAMA (Kansai Gaidai Univ.)
Kanetada NAGAMINE (Inst. Mater. Struc. Sci., KEK)
Nobuyuki NAKAMURA (Inst. Laser Sci., Univ. Electro-Commun.)Takashi NAKAMURA (KEK)
Tetsuya NAKAZAWA (Tokai Res. Estab., JAERI)
Megumi NIIGAKI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Tamio NISHIMURA (Dept. Chim., Univ. Roma, Italy)
Shunsuke OHTANI (Inst. Laser Sci., Univ. Electro-Commun.)
Nagayasu OSHIMA (Grad. Sch. Arts Sci., Univ. Tokyo)
Norio OKABAYASHI (Grad. Sch. Arts Sci., Univ. Tokyo)
Kunihiro OKADA (Fac. Sci. Technol., Sophia Univ.)
Satoru OKAYASU (Tokai Res. Estab., JAERI)
Kazuhiko OKUNO (Dept. Phys., Tokyo Metrop. Univ.)
Fumihisa ONO (Fac. Sci., Okayama Univ.)
Lukas PICHL (Found. Comput. Sci. Lab., Univ. Aizu)
Yi-Zhi QU (Univ. Sci. Technol. China, China)Frank B. ROSMEJ (GSI, Germany)
Syuiti SAKAGUTI (Fac. Eng., Yamaguchi Univ.)
Akio SAKAI (Vacuum Products Co.)
Reinhold SCHUCH (Phys. Dept., Stockholm Univ., Sweden)
Hans A. SCHUESSLER (Texas A & M Univ., USA)
Noriyuki SHIMAKURA (Fac. Sci., Niigata Univ.)
Isao SHIMAMURA
Hiroya SUNO (Fac. Eng., Yamaguchi Univ.)
Aiko TAKAMINE (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Károly TÖKÉSI (ATOMKI, Hungary)
Hiroyuki TORII (Grad. Sch. Arts Sci., Univ. Tokyo)
Nobuyuki TOSHIMA (Inst. Appl. Phys., Univ. Tsukuba)
Hidetsugu TSUCHIDA (Fac. Sci., Nara Women’s Univ.)
Kiyoshi UEDA (Res. Inst. Sci. Meas., Tohoku Univ.)
Victor VARENTSOV (V. G. Khlopin Radium Inst., Russia)
Akira YAGISHITA (KEK)
Yutaka YOSHIDA (Shizuoka Inst. Sci. Technol.)
Ken YOSHIKI FRANZÉN (Grad. Sch. Arts Sci., Univ. Tokyo)
Yaming ZOU (Shanghai Jiao Tong Univ., China)
Trainees
Pierre HOSTEINS (Univ. Paris XI-Orsay, France)
Masato INOUE (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Hiroaki KANEMITSU (Dept. Phys., Okayama Univ.)
Seiji KOMATSU (Dept. Phys., Okayama Univ.)
Chikara KONDOU (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Naofumi KURODA (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Takuya MAJIMA (Grad. Sch. Eng., Kyoto Univ.)
Saburou MASUGI (Dept. Phys., Tokyo Metrop. Univ.)
Tomoko MURANAKA (Dept. Phys., Tokyo Metrop. Univ.)371

Hiroyuki SHIMADA (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Tetsu SONODA (Grad. Sch. Sci., Tohoku Univ.)
Masashi TERADA (Inst. Laser Sci., Univ. Electro-Commun.)
Heavy Ion Nuclear Physics Laboratory
Head
Tohru MOTOBAYASHIMembers
Takashi ICHIHARA
Yasushi WATANABE
Yoshiyuki YANAGISAWA
Nobuaki IMAI∗1
Satoshi TAKEUCHI∗2∗1∗2

Takashi KISHIDA
Nori AOI
Naoki FUKUDA∗1
Masaaki TAKASHINA∗1
Meiko UESAKA-KUROKAWA∗2

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Masato ASAI (JAERI)
Daniel BAZIN (Natl. Supercond. Cycl. Lab., Michigan State Univ., USA)
Didier BEAUMEL (Paris-XI Univ., IPN-Orsay, France)
Mottelson R BEN (NORDITA, Copenhagen, Denmark)Shawn BISHOP (JSPS)
Yorick BLUMENFELD (Paris-XI Univ., IPN-Orsay, France)
Peter von BRENTANO (Inst. fur Kern Phys., Univ. zu Koeln, Germany)
Rick CASTEN (Phys. Dept., BNL, USA)
Rangacharyulu CHILAKAMARRI (Univ. Saskatchewan, Canada)
Zsolt DOMBRADI (Inst. Nucl. Res., Hung. Acad. Sci., Hungary)
Zoltan ELEKES (Inst. Nucl. Res., Hung. Acad. Sci., Hungary)Francis A. BECK (CRN, Strasbourg, France)
Mitsunori FUKUDA (Grad. Sch. Sci., Osaka Univ.)
Tomokazu FUKUDA (Osaka Electro-Commun. Univ.)
Kazuyoshi FURUTAKA (Jpn. Nucl. Cycl. Dev. Inst.)
Zsolt FÜLÖP (Inst. Nucl. Res. Hung. Acad. Sci., Hungary)
Janos GAL (Inst. Nucl. Res. Hung. Acad. Sci., Hungary)
Adrian GELBERG (Inst. Kern Phys., Univ. Koeln, Germany)
Johannes G. MESSCHENDORP (Univ. Groningen, The Netherland)
Guan-Hua LIU (Inst. Modern Phys., China)
Hisashi HORIUCHII (Fac. Sci., Kyoto Univ.)
Akos HORVATH (Dept. Atom. Phys., Eotvos Lorand Univ., Hungary)
Flocard HUBERT (CSNSM, Orsay, France)
Munetake ICHIMURA (Univ. Air)
Kazuo IEKI (Coll. Sci., Rikkyo Univ.)
Tetsurou ISHII (JAERI)
Jingbin LU (Fac. Sci., Kyushu Univ.)
Gibelin J. DIDIER (Coll. Sci., Rikkyo Univ.)
Tsuneyoshi KAMAE (Stanford Univ., USA)
Zirouta KASAGI (Lab. Nucl. Sci., Tohoku Univ.)
Seigo KATOU (Fac. Ed., Yamagata Univ.)
Kazuyoshi KURITA (Coll. Sci., Rikkyo Univ.)
Nasser KALANTAR-NAYESTANAKI (Univ. Groningen, The Netherland)
Gabor KALINKA (Inst. Nucl. Res., Hung. Acad. Sci., Hungary)
Victor LIMA (Paris-XI Univ., IPN-Orsay, France)
Ken-ichi MATSUYANAGI (Fac. Sci., Kyoto Univ.)
Shirou MITARAI (Fac. Sci., Kyushu Univ.)
Hiroari MIYATAKE (KEK)
Tsuneyasu MORIKAWA (JAERI)
Shunpei MORINOBU (Fac. Sci., Kyushu Univ.)372

Takeshi MURAKAMI (Natl. Inst. Radiol. Sci.)
Hiroyuki MURAKAMI (Coll. Sci., Rikkyo Univ.)
Vinodkumar Mayyan ATTUKALATHIL (Fac. Sci., Tokyo Inst. Technol.)
Alberto MENGONI (ENEA, Italy)Peter MOLLER (Los Alamos Natl. Lab., USA)
Yasuki NAGAI (RCNP, Osaka Univ.)
Takashi NAKAMURA (Fac. Sci., Tokyo Inst. Technol.)
Shintaro NAKAYAMA (Fac. Integr. Arts Sci., Univ. Tokushima)
Takashi NIIZEKI (Tokyo Kasei Univ.)
Tetsuo NORO (Fac. Sci., Kyushu Univ.)
Atsuko ODAHARA (Nishinippon Inst. Technol.)
Hiroyuki OKAMURA (Grad. Sch. Sci., Tohoku Univ.)
Makito OOI (Fukui Univ.)
Masumi OOSIMA (JAERI)
Hikonojou ORIHARA (Cycl. Radioisot. Cen., Tohoku Univ.)
Broglia A. RICARD (Univ. Milano, Italy)
Chilakamarri RANGACHARYULU (Univ. Saskatchewan, Canada)
Akito SAITO (Coll. Sci., Rikkyo Univ.)
Harutaka SAKAGUCHI (Fac. Sci., Kyoto Univ.)
Hiroyuki SAKURAGI (Fac. Sci., Osaka City Univ.)
Hiroyoshi SAKURAI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Yoshiteru SATOU (Fac. Sci., Tokyo Inst. Technol.)
Yoshifumi SHIMIZU (Fac. Sci., Kyushu Univ.)
Hazime SHIMIZU (Fac. Ed., Yamagata Univ.)
Shoko KANNO (Coll. Sci., Rikkyo Univ.)
Masahiko SUGAWARA (Chiba Inst. Technol.)Yasuyuki SUZUKI (Fac. Sci., Niigata Univ.)
Toshio SUZUKI (Fac. Eng., Fukui Univ.)
Shuwei XU (Inst. Modern Phys., Chin. Acad. Sci., China)
Dorottya SOHLER (Inst. Nucl. Res., Hung. Acad. Sci., Hungary)
Yasuhisa TAJIMA (Cycl. Radioisot. Cen., Tohoku Univ.)
Eiichi TAKADA (Natl. Inst. Radiol. Sci.)
Tadayuki TAKAHASHI (Inst. Space Astronaut. Sci.)
Noboru TAKIGAWA (Grad. Sch. Sci., Tohoku Univ.)
Atsushi TAMII (RCNP, Osaka Univ.)
Atsushi TANOKURA (Fac. Sci. Technol., Sophia Univ.)
Atsuki TERAKAWA (Cycl. Radioisot. Cen., Tohoku Univ.)
Masahiro UNO (MEXT)
Kentarou YAKOU (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Ken-ichirou YONEDA (Natl. Supercond. Cycl. Lab., Michigan State Univ., USA)
Naotaka YOSHINAGA (Fac. Sci., Saitama Univ.)
Masaru YOSOI (Fac. Sci., Kyoto Univ.)
Trainees
Hidetada BABA (Coll. Sci., Rikkyo Univ.)
Ryosuke HADATE (Coll. Sci., Rikkyo Univ.)
Naho HOKOIWA (Fac. Sci., Kyushu Univ.)
Hooi Jin ONG (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Yuichi ICHIKAWA (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Kazuhiro ISHIKAWA (Fac. Sci., Tokyo Inst. Technol.)Shoko KAWAI (Coll. Sci., Rikkyo Univ.)
Michiya KIBE (Fac. Sci., Kyushu Univ.)
Takayuki KINOSHITA (Coll. Sci., Rikkyo Univ.)
Yousuke KONDOU (Fac. Sci., Tokyo Inst. Technol.)
Hironori KUBOKI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Yukie MAEDA (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Nobuyuki MATSUI (Coll. Sci., Rikkyo Univ.)
Yuichi MATSUYAMA (Coll. Sci., Rikkyo Univ.)
Hiroyuki NAKAYAMA (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Haruki NISHINO (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)

373

Takeo ONISHI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Takaaki SAITO (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Shouta SAITO (Coll. Sci., Rikkyo Univ.)
Hazuki SAKAI (Coll. Sci., Rikkyo Univ.)
Tomoyuki SAKURADA (Coll. Sci., Rikkyo Univ.)
Masaki SASANO (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Junichi SATO (Coll. Sci., Rikkyo Univ.)
Takashi SUGIMOTO (Fac. Sci., Tokyo Inst. Technol.)Hiroshi SUZUKI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Masaru SUZUKI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Daisuke SUZUKI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Yoshiyuki TAKAHASHI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Yasuhiro TOGANO (Coll. Sci., Rikkyo Univ.)
Kazuma TSURUSAKI (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
Hirotaka UENO (Coll. Sci., Rikkyo Univ.)
Naori UMEZAWA (Coll. Sci., Rikkyo Univ.)
Kazuya URUSHIBARA (Coll. Sci., Rikkyo Univ.)
Yasuo WAKABAYASHI (Fac. Sci., Kyushu Univ.)
Takeshi WATANABE (Coll. Sci., Rikkyo Univ.)
Kazunari YAMADA (Coll. Sci., Rikkyo Univ.)
Magnetic Materials Laboratory
Head
Hidenori TAKAGIMembers
Masayuki HAGIWARA
Hiroki YAMAZAKI
Hiroyuki YAMASE∗1
Hiroaki UEDA∗2∗1∗2

Hiroko KATORI
Koshi TAKENAKA
Katsuya IWAYA∗1

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Hirokazu TSUNETSUGU (Yukawa Inst. Theoretical Phys.)
Masaaki MATSUDA (Natl. Inst. Mater. Sci.)
Trainees
Tomohiro TAKAYAMA (Adv. Mater. Sci., Univ. Tokyo)
Haritoki SHIMURA (Adv. Mater. Sci., Univ. Tokyo)
Muon Science Laboratory
Head
Masahiko IWASAKIMembers
Teiichiro MATSUZAKI
Haruhiko OUTA
Yasuyuki MATSUDA
Takahisa KOIKE∗1
Seiko OHIRA∗2∗1∗2

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Tadashi ADACHI (Fac. Eng., Tohoku Univ.)
Yoshitami AJIRO (Fac. Sci., Kyushu Univ.)

374

Katsuhiko ISHIDA
Isao WATANABE
Kenta ITAHASHI
Patrick STRASSER∗2
Pavel BAKULE∗2

Jun AKIMITSU (Coll. Sci. Eng., Aoyama Gakuin Univ.)
Megumi AKOSHIMA (Adv. Inst. Sci. Technol.)
Juichiro ARAI (Tokyo Univ. Sci.)
Shingo ARAKI (Fac. Sci., Osaka Univ.)
Kunio AWAGA (Grad. Sch. Arts Sci., Univ. Tokyo)
George A. BEER (Univ. Victoria, Canada)Hyoung Chan BHANG (Seoul Natl. Univ., Korea)
Ludmila Nikolaevna BOGDANOVA (Inst. Theor. Exp. Phys., Russia)
Tina M. BRIERRE (Inst. Metal Sci., Tohoku Univ.)
Tara Prasad DAS (State Univ. New York, USA)
Don FLEMING (TRIUMF, Canada)
Yutaka FUJII (Fac. Eng., Fukui Univ.)
Masaki FUJITA (Inst. Chem. Res., Kyoto Univ.)
Atsuko FUKAYA (IMR, Tohoku Univ.)
Makoto HAGIWARA (Fac. Eng. Design, Kyoto Inst. Technol.)
Wataru HIGEMOTO (KEK)
Masahiro HIRANO (JST)Emiko HIYAMA (KEK)
Susumu IKEDA (KEK)
Shigeru ISHIMOTO (KEK)
Atsuko ITO
Ryosuke KADONO (KEK)
Masayasu KAMIMURA (Fac. Sci., Kyushu Univ.)
Mineo KATO (Tokai Res. Estab., JAERI)
Naritoshi KAWAMURA (KEK)
Yasushi KINO (Fac. Sci., Tohoku Univ.)
Youji KOIKE (Fac. Eng., Tohoku Univ.)
Yoshitaka KUNO (Fac. Sci., Osaka Univ.)
Hong LI (Michigan State Univ., USA)
Roderick MACRAE (Marian Coll., Indianapolis, USA)
Syunsuke MAKIMURA (KEK)
Goro MARUTA (Fac. Sci., Hokkaido Univ.)
Yasuhiro MIYAKE (KEK)
Satoshi N. NAKAMURA (Fac. Sci., Tohoku Univ.)
Takashi NAKAMURA (Fac. Sci., Tokyo Inst. Technol.)
Takayoshi NAKAMURA (Res. Inst. Electron. Sci., Hokkaido Univ.)
Takehito NAKANO (Fac. Sci., Osaka Univ.)
Nobuhiko NISHIDA (Fac. Sci., Tokyo Inst. Technol.)Kusuo NISHIYAMA (KEK)
Yasuo NOZUE (Fac. Sci., Osaka Univ.)
Vassili V. PEREVOZCHIKOV (Russ. Fed. Nucl. Cen., Russia)
Leonid I. PONOMAREV (Kurchatov Inst., Russia)
Francis L. PRATT (RAL, UK)
Shinichi SAKAMOTO (Tokai Res. Estab., JAERI)
Ryoichi SEKI (California State Univ., USA)
Koichiro SHIMOMURA (KEK)
Vyacheslav G. STORCHAK (Kurchatov Inst., Russia)
Hiroyuki SUGAI (Tokai Res. Estab., JAERI)
Keiji TAKEDA (Fac. Sci., Hokkaido Univ.)
Masashi TAKIGAWA (Inst. Solid State Phys.)
Masakazu TANASE (Takasaki Res. Estab., JAERI)
Eiko TORIKAI (Fac. Eng., Yamanashi Univ.)
Akihisa TOYODA (KEK)
Kazuo UEDA (Inst. Solid State Phys.)
Kazuyoshi YAMADA (IMR, Tohoku Univ.)
A. A. YUKHIMCHUK (Russ. Fed. Nucl. Cen., Russia)
Johann ZMESKAL (IMEP, Austria)
Trainees
Soichiro ARIMURA (Fac. Sci., Osaka Univ.)375

Aya HINO (Fac. Sci., Tohoku Univ.)
Yutaka IKEDO (Fac. Eng., Yamanashi Univ.)
Hiroshi IMAO (Fac. Sci., Univ. Tokyo)
Mijung KIM (Seoul Natl. Univ., Korea)
Yoshihiro KUBOTA (Fac. Sci., Tohoku Univ.)
Sougo KUROIWA (Fac. Sci. Eng., Aoyama Gakuin Univ.)
Satoru MATUISHI (Fac. Sci., Tokyo Inst. Technol.)
Sadafumi NISHIHARA (Grad. Sch. Environ. Earth Sci., Hokkaido Univ.)
Naoki OKI (Fac. Eng., Tohoku Univ.)
RIADIANA (Fac. Eng., Tohoku Univ.)
Hiroki SHIBATA (Fac. Sci., Tohoku Univ.)
Hyeongryrul SO (Seoul State Univ., Korea)
Hiroyuki TANAKA (Fac. Sci., Nagoya Univ.)
Maki YAMAZAWA (Fac. Sci. Eng., Aoyama Gakuin Univ.)
Beam Physics and Engineering Laboratory
Head
Takeshi KATAYAMA
Members
Manabu HAMAGAKIMasato NAKAMURA
Shuichi OZAWA∗1
Masao TAKANAKA∗2
Masao WATANABE∗2∗1∗2

Tadashi KOSEKI
Masahiro OKAMURA
Akira SAKUMI∗1
Moritake TAMBA
Tamaki WATANABE

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Hiroshi AMEMIYA
Yoshihiko CHIBA
Yoshihide FUCHI (KEK)
Tomonori FUKUCHI(CNS, Univ. Tokyo)
Kevin Insik HAHN (Ewha Woman’s Univ., Korea)
Hideki HAMAGAKI (CNS, Univ. Tokyo)
Tamio HARA (Toyota Technol. Inst.)
Yuichi HASHIMOTO (Canon Inc.)
Toshiyuki HATTORI (Res. Lab. Nucl. React., Tokyo Inst. Technol.)
Jianjun HE (CNS, Univ. Tokyo)
Eiji IDEGUCHI (CNS, Univ. Tokyo)
Masashi IMANAKA (CNS, Univ. Tokyo)
Masahide INUZUKA (CNS, Univ. Tokyo)
Hironobu ISHIYAMA (KEK)
Hironori IWASAKI (CNS, Univ. Tokyo)
Robert A. JAMESON (Los Alamos Natl. Lab., USA)
Daiya KAJI (CNS, Univ. Tokyo)
Teruo KANEDA (Tokyo Electr. Univ.)
Seigo KATO (Univ. Yamagata)
Shigeki KATO (KEK)
Souichiro KAMETANI (Waseda Univ.)
Takahiro KAWABATA (CNS, Univ. Tokyo)
Takashi KIKUCHI (CNS, Univ. Tokyo)
Jongchan KIM (Seoul Univ., Korea)
Ka-hae KIM (CNS, Univ. Tokyo)
Yasuro KOIKE (Hosei Univ.)
Shigeru KUBONO (CNS, Univ. Tokyo)
Rubens Filho LICHTENTHALER (Sao Paulo Univ., Brazil)
Takashi MATSUMOTO (CNS, Univ. Tokyo)
Igor MESHKOV (JINR, Russia)

376

Shin’ichiro MICHIMASA (Univ. Tokyo)
Hirofumi MIYAZAKI (Sumitomo Heavy Ind. Ltd.)
Dieter MOEHL (CERN, Switzerland)
Toshihiro NISHIDA (Tokyo Inst. Technol.)
Masaki NISHIURA (Natl. Inst. Fusion Sci.)
Masahiro NOTANI (CNS, Univ. Tokyo)
Masao OGAWA (Tokyo Inst. Technol.)
Yoshiyuki OGURI (Res. Lab. Nucl. React., Tokyo Inst. Technol.)
Yukimitsu OHSHIRO (CNS, Univ. Tokyo)
Hiromi OKAMOTO (Hiroshima Univ.)
Kiyohiko OKAZAKI
Ken OYAMA (Univ. Tokyo)
Kyoichiro OZAWA (CNS, Univ. Tokyo)
Takao SAKAGUCHI (CNS, Univ. Tokyo)
Mitsuo SAKAI (CNS, Univ. Tokyo)
Takeshi SAKAKIBARA (Chuo Univ.)
Yuichi SAKAMOTO (Nichimen Co.)
Yuichiro SASAKI (Matsushita Electric Ind., Ltd.)
Masaki SERATA (Coll. Sci., Rikkyo Univ.)
Takaichi SHIMAZAKI (CNS, Univ. Tokyo)
Susumu SHIMOURA (CNS, Univ. Tokyo)
Anatoly SIDORIN (JINR, Russia)
Alexander SKRINSKY (ITEP, Russia)
Alexandre SMIRNOV (JINR, Russia)
Kazuo SUGII (Osaka Vacuum, Ltd.)
Masaharu SUZUKI (CNS, Univ. Tokyo)
Evgeny SYRESIN (JINR, Russia)
Motonobu TAKANO
Masahiko TANAKA (KEK)
Takashi TERANISHI (CNS, Univ. Tokyo)
Mariko TERASAWA (CNS, Univ. Tokyo)
Hiroshi TSUTSUI (Sumitomo Heavy Ind., Ltd.)
Meiko UESAKA (CNS, Univ. Tokyo)
Tomohiro UESAKA (CNS, Univ. Tokyo)
Guimaraes VALDIR (Sao Paulo Univ., Brazil)
Takashi WAKUI (CNS, Univ. Tokyo)
Shin-ichi WATANABE (CNS, Univ. Tokyo)
Yutaka WATANABE (KEK)
Meiqin XIAO (Fermi Natl. Accel. Lab., USA)
Kentaro YAKO (CNS, Univ. Tokyo)
Shoichi YAMAKA (CNS, Univ. Tokyo)
Kazuo YAMAMOTO (Tokyo Inst. Technol.)
Norio YAMAZAKI (CNS, Univ. Tokyo)
Katsuki YANO
Chong Cheoul YUN (Chung-Ang Univ., Korea)
Trainees
Taku GUNJI (Univ. Tokyo)
Takashi HASHIMOTO (Tokyo Univ. Sci.)
Tomoko ISHIKAWA (Tokyo Univ. Sci.)
Tadaaki ISOBE (Waseda Univ.)
Fukutaro KAJIHARA (Univ. Tokyo)
Koichi KATO (Waseda Univ.)
Tomoyuki KAWAMURA (Yamagata Univ.)
Narumi KURIHARA (Univ. Tokyo)
Eun Kyung LEE (Ewha Woman’s Univ., Korea)
Ju Hahn LEE (Chung-Ang Univ., Korea)
Jun Young MOON (Chung-Ang Univ., Korea)
Daisuke NAGAE (Tokyo Inst. Technol.)Megumi NIIKURA (Univ. Tokyo)

377

Shinya OGAWA (Tokyo Inst. Technol.)
Susumu ODA (Univ. Tokyo)
Shinsuke OTA (Kyoto Univ.)
Junpei TAKANO (Tokyo Inst. Technol.)
Hiroyuki SATO (Yamagata Univ.)
Mituru TAMAKI (Univ. Tokyo)
Yorito YAMAGUCHI (Waseda Univ.)
Cellular Physiology Laboratory
Head
Fumio HANAOKA
Members
Fumio YATAGAI
Visiting Members
Koichi ANDO (Natl. Inst. Radiol. Sci.)
Yoshiya FURUSAWA (Natl. Inst. Radiol. Sci.)
Yoshimasa HAMA (Sci. Eng. Inst., Waseda Univ.)
Nobutoshi ITOH (Fac. Sci., Univ. Tokyo)
Tatsuaki KANAI (Natl. Inst. Radiol. Sci.)
Kiyomi KASAI (Natl. Inst. Radiol. Sci.)
Yasuhiko KOBAYASHI (JAERI)
Hiroshi WATANABE (JAERI)
Masami WATANABE (Fac. Pharm. Sci., Nagasaki Univ.)
Shoji YAMASHITA (Natl. Saitama Hospital)
Plant Functions Laboratory
Head
Shigeo YOSHIDA
Members
Tomoko ABE
Yutaka MIYAZAWA∗1
Hiroyuki SAITO∗1∗1∗2

Tomoki MATSUYAMA
Koichi SAKAMOTO∗1
Yoshiharu YAMAMOTO∗2

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Chang-Hyu BAE (Sunchon Natl. Univ., Korea)
Koji FURUKAWA (Mukoyama Orchids Co. Ltd.)
Misako HAMATANI (Hiroshima City Agr. Forest. Promot. Cen.)
Yasuhide HARA (Kanagawa Inst. Agr. Sci.)
Masanori HATASHITA (Wakasa Wan Energy Res. Cen.)
Atsushi HIGASHITANI (Grad. Sch. Life Sci., Tohoku Univ.)
Ichiro HONDA (Natl. Agr. Res. Cen., Min. Agr. Forest. Fish.)Mitsugu HORITA (Hokkaido Green-bio Inst.)
Yuji ITO (Inst. Rad. Breeding, Natl. Inst. Agr. Res.)
Hiroshi KAGAMI (Shizuoka Citrus Exp. Station)
Toshiaki KAMEYA (Grad. Sch. Life Sci., Tohoku Univ.)
Takeo KITAURA (Kanagawa Inst. Agr. Sci.)
Kazumitsu MIYOSHI (Fac. Bioresource Sci., Akita Pref. Univ.)
Toshikazu MORISHITA (Inst. Rad. Breeding, Natl. Inst. Agr. Res.)Jin Heui PARK (Coll. Life Environ., Sci., Korea Univ., Korea)
Takiko SHIMADA (Res. Inst. Agr. Resources, Ishikawa Agr. Coll.)
Masao SUGIYAMA (Hokko Chemical Ind. Co., Ltd.)
Kazunori SUZUKI (Plant Biotech. Inst. Ibaraki Agr. Cen.)

378

Kenichi SUZUKI (Suntory Flowers Ltd.)Ken TOKUHARA (Dogashima Orchid Cen.)
Takuji YOSHIDA (Takii Seed Co., Ltd.)
Hisashi TSUJIMOTO (Fac. Agr., Tottori Univ.)
Masao WATANABE (Fac. Agr., Iwate Univ.)
Trainees
Sadao GUNJI (Miyazaki Agr. Exp. Station)
Tetsuji KINOSHITA (Miyazaki Agr. Exp. Station)
Tomojiro KOIDE (RIKEN Vitamin Co., Ltd.)
Eikou OOYABU (Saga Agr., Exp. Station)
Ryoko ONUMA (Fac. Sci., Tokyo Univ. Sci.)
Minoru SAITO (Fukui Agr. Exp. Station)
Kei-ichiro UENO (Kagoshima Biotech. Inst.)
Tetsuya UMEKI (Miyazaki Agr. Exp. Station)
CYCLOTRON CENTER
Chief Scientist
Yasushige YANOMembers
Noritaka SHIMIZU∗1
Nguyen DINH DANG∗2
Hideki MADOKORO∗2

Satoru SUGIMOTO∗1
Yuko MOTIZUKI∗2
Kiyomi IKEDA∗3∗1

Special Postdoctoral Researcher
Contract Researcher∗3
Temporary Employee∗2

Visiting Members
Shinichiro FUJII (Fac. Sci., Univ. Tokyo)
Hiroyuki KOURA (Fac. Sci. Eng., Waseda Univ.)
Shoushichi MOTONAGA
Shigeo NUMATA
Takaharu OTSUKA (Fac. Sci., Univ. Tokyo)
Mutsuko SASAKI
Shuhei YAMAJI (Kanagawa Inst. Technol.)Yu-Min ZHAO (South East Univ., China)
Beam Dynamics Division
Head
Akira GOTO
Members
Takashi EMOTO
Masanori WAKASUGIKoichi YOSHIDA
Nobuhisa FUKUNISHI
Naruhiko SAKAMOTO
Kimiko SEKIGUCHI∗1
Yutaka MIZOI∗2∗1∗2

Toshiyuki KUBO
Osamu KAMIGAITO
Atsushi YOSHIDA
Jun-ichi OHNISHI
Toshiyuki MINEMURA∗1
Kensuke KUSAKA∗2

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Yoshiaki CHIBA
Takashi FUJISAWA (N. I. R. S.)
Mitsuhiro FUKUDA (Takasaki Res. Estab., JAERI)

379

Toshihiro HONMA (N. I. R. S.)
Shinji MACHIDA (KEK)Toshinori MITSUMOTO (Sumitomo Heavy Ind., Ltd.)
Yoshiharu MORI (KEK)
Hiroyuki OKAMURA (Dept. Phys., Saitama Univ.)
Serguei VOROJTSOV (J. I. N. R., Dubna, Russia)
Trainees
Takahiro AKIYAMA (Dept. Phys., Saitama Univ.)
Takashi HASEGAWA (Cycl. Radioisot. Cen., Tohoku Univ.)
Motooki HOSOI (Dept. Phys., Saitama Univ.)
Takuichiro IKEDA (Dept. Phys., Saitama Univ.)
Keisuke ITOH (Dept. Phys., Saitama Univ.)
Youhei SHIMIZU (RCNP, Osaka Univ.)
Kenji SUDA (Dept. Phys., Saitama Univ.)
Kousuke SUGAWARA (Dept. Phys., Saitama Univ.)
Naoya SUGIMOTO (Cycl. Radioisot. Cen., Tohoku Univ.)
Eri TAKESHITA (Coll. Sci., Rikkyo Univ.)
Reiko TAKI (Michigan State Univ., USA)
Yuji TAMESHIGE (RCNP, Osaka Univ.)
Beam Technology Division
Head
Masayuki KASE
Members
Kosuke MORITA
Toshiya TANABE
Jiro FUJITA
Makoto NAGASE
Shigeo KOHARA
Naohito INABE
Keiko KUMAGAI
Sachiko ITO
Yoshihide HIGURASHI∗1
Akiko MASUDA∗1
Tadashi FUJINAWA∗2
Hisao SAKAMOTO∗2
Akira YONEDA∗2
Kenichi YAMAGUCHI∗3
Tsutomu YAMAKI∗3

Takahide NAKAGAWA
Kiminori USHIDA
Kiyoshi OGIWARA
Tadashi KAGEYAMA
Eiji IKEZAWA
Masaki FUJIMAKI
Shin FUJITA
Kouji MORIMOTO
Masanori KIDERA∗1
Hiromichi RYUTO∗1
Misaki KOMIYAMA∗2
Shigeru YOKOUCHI∗2
Ichiro YOKOYAMA∗3
Yoshitoshi MIYAZAWA∗3∗1

Contract Researcher
Contract Technical Scientist∗3
Temporary Employee∗2

Visiting Members
Keisuke ASAI (Grad. Sch. Eng., Univ. Tokyo)
Hiroaki ASAI (NASDA)
Shinji BABA (NASDA)
Sudeep BHATTACHARJEE (Univ. Wisconsin-Madison, USA)
Toshiya CHIBA
Alexander EREMINE (Flerov Lab. Nucle. React., Russia)
Kaoru FURUSE (NASDA)
Yasuyuki FUTAMI (N. I. R. S.)
Shin-ichi GOTO (Fac. Sci., Niigata Univ.)
Kichiji HATANAKA (RCNP, Osaka Univ.)
Yuichi HATSUKAWA (Tokai Res. Estab., JAERI)
Ryugo S. HAYANO (Fac. Sci., Univ. Tokyo)
Masatake HEMMI380

Yoshiya IIDE (NASDA)
Seiji IIO (Sumitomo Heavy Ind. Ltd.)
Naomi IKEDA (NASDA)
Hiroshi IKEZOE (Tokai Res. Estab., JAERI)
Takashi INAMURA
Masayuki ITO (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
Ichiro KATAYAMA (KEK)
Kazuie KIMURA (Dept. Eng., Univ. Tokyo)
Osamu KOYAMA (Katagiri Eng. Co. ltd.)
Satoshi KUBOYAMA (NASDA)
Hisaaki KUDO (Fac. Sci., Niigata Univ.)
Tadahiro KUROSAWA (Electrotech. Lab., Agency Ind. Sci. Tech.)Toshikatsu MASUOKA (Nichizo Electric & Control Corp.)
Sumio MATSUDA (NASDA)
Hideo MIKAMI (Sumitomo Heavy Ind., Ltd.)
Tadanori MINAMISONO (Grad. Sch. Sci., Osaka Univ.)
Hiroari MIYATAKE (KEK)
Tetsuya MURAKAMI (Grad. Sch. Sci., Kyoto Univ.)
Yuki NAGAI (NASDA)
Noriaki NAKAO (KEK)
Toru NOMURA (KEK)
Jyun-ichi ODAGIRI (KEK)
Hideharu OHIRA (NASDA)
Koji OISHI (Shimizu Construction Co., Ltd)
Katsumi OKA (NASDA)
Hiromitsu OOTOMO (NASDA)
Kenshi SAGARA (Fac. Sci., Kyushu Univ.)
Hideyuki SAKAI (Dept. Phys., Sch. Sci., Univ. Tokyo)
Hiroki SATO (NASDA)
Eido SHIBAMURA (Saitama Pref. Jr. Coll.)
Osamu SHIMADA (NASDA)
Hiroyuki SHINDO (NASDA)
Tsutomu SHINOZUKA (Cycl. Radioisot. Cen., Tohoku Univ.)
Keisuke SUEKI (Inst. Chem., Univ. Tsukuba)
Isao SUGAI (KEK)
Masami SUZUKI (Irie Koken Co. Ltd.)
Sung Chang JEONG (KEK)
Hiroaki UTSUNOMIYA (Fac. Sci., Konan Univ.)
Masakazu WASHIO (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
Yuji YAMAKAWA (Shimizu Construction Co., Ltd)Yu-liang ZHAO (Inst. High Energy Phys., Beijing, China)
Trainees
Kentaro ASAI (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
Masataka KOBAYASHI (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
Masanori KOSHIMIZU (Dept. Eng., Grad. Sch. Eng., Univ. Tokyo)
Takehiko KURIBAYASHI (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
Masakazu MORI (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
Rei UMEBAYASHI (Dept. Eng., Grad. Sch. Eng., Univ. Tokyo)
Radioisotope Technology Division
Head
Fumio YATAGAI
Members
Kuniko MAEDA
Shuichi ENOMOTO
Masako IZUMIHiromitsu HABA∗1
Rieko HIRUNUMA∗2

Kazuya TAKAHASHI
Hiroshige TAKEICHI
Teruyo TSUKADA
Takahiro YANAGIYA∗1
Kaori IGARASHI∗2

381

Shigeko MORIMOTO∗2
Akihiro NAKAYAMA∗2
Takayuki SOSHI∗2∗1∗2

Shinji MOTOMURA∗2
Qiangyan PAN∗2
Masanori TOMITA∗2Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Ryohei AMANO (Fac. Med., Kanazawa Univ.)
Sachiko AMARI (Washington Univ., USA)
Wenjun DING (Colorado State Univ., USA)
Kazutoyo ENDO (Showa Pharm. Univ., USA)
Tatsunori FUKUMAKI (Japan NUS Co., Ltd.)
Mika FUKUOKA (Tokyo Univ. Fish.)
Sachiko GOTO (Sch. Pharm. Sci., Nagasaki Univ.)
Ken-ichi HASEGAWA (Fac. Eng., Hosei Univ.)
Hiroshi HIDAKA (Fac. Sci., Hiroshima Univ.)
Seiichiro HIMENO (Fac. Pharm. Sci., Tokushima Bunri Univ.)
Eiko HIRANO (Japan NUS Co., Ltd.)
Masahiko HIRASAWA (Natl. Inst. Radiol. Sci.)
Masamitsu HONMA (Natl. Inst. Health Sci.)
Naoko IKEDA (Showa Women’s Univ.)
Hiroko INAGE (Int. Life Sci. Inst.)
Nobuyoshi ISHII (Natl. Inst. Radiol. Sci.)
Toshiaki ISHII (Natl. Inst. Radiol. Sci.)
Atsushi ITO (Sch. Eng., Tokai Univ.)
Hiroyuki KAGI (Grad. Sch. Sci., Univ. Tokyo)
Kenji KAWABE (Kyoto Pharm. Univ.)
Osamu KAWAGUCHI (Sch. Med., Keio Univ.)
Tetsuya KAWATA (Fac. Med., Chiba Univ.)
Masuo KONDOH (Showa Pharm. Univ.)
Hideaki MAEKAWA (Natl. Inst. Infect. Dis.)
Hiroshi MAEZAWA (Fac. Med. Technol., Univ. Tokushima)
Ken-ichiro MATSUMOTO (Showa Pharm. Univ.)
Yoshitaka MINAI (Cen. Art. Sci., Musashi Univ.)
Takeshi MINAMI (Dept. Life Sci., Sch. Sci. Eng., Kinki Univ.)
Tomohiro NABEKURA (Fac. Pharm. Sci., Niigata Univ. Pharm. Appl. Life Sci.)
Yuichiro NAGAME (JAERI)
Tomoko NAKANISHI (Grad. Sch. Agr. Life Sci., Univ. Tokyo)
Yukiko NAKANISHI (Int. Life Sci. Inst.)
van Chuyen NGUYEN (Jpn. Women’s Univ.)
Takehiko NOHMI (Natl. Inst. Health Sci.)
Yasumitsu OGURA (Grad. Sch. Pharm. Sci., Chiba Univ.)
Takeo OHNISHI (Fac. Biol., Nara Med. Univ.)
Toshihiro OHTA (Fac. Life Sci., Tokyo Univ. Pharm. Life Sci.)
Takuya OHYAMA (Grad. Sch. Sci. Technol., Shizuoka Univ.)
Jun SAITO (Iwatsu Test Instruments Corp.)
Tomofumi SAKURAGI (Natl. Inst. Radiol. Sci.)
Hiromu SAKURAI (Kyoto Pharm. Univ.)
Sadao SHIBATA (Natl. Inst. Radiol. Sci.)
Hiroshi SHIMIZU (Fac. Sci., Hiroshima Univ.)
Atsushi SHINOHARA (Dept. Chem., Grad. Sch. Sci., Osaka Univ.)
Hiroyuki SUZUKI (RI Res. Cen., Chiba Univ.)
Kazuo T. SUZUKI (Grad. Sch. Pharm. Sci., Chiba Univ.)
Toshihiro SUZUKI (Meiji Pharm. Univ.)
Keiko TAGAMI (Natl. Inst. Radiol. Sci.)
Akihisa TAKAHASHI (Fac. Biol., Nara Med. Univ.)
Masaaki TAKAHASHI (Grad. Sch. Agr. Biol. Sci., Osaka Pref. Univ.)
Miho TAKAHASHI (Tokyo Univ. Fish.)
Yoshio TAKAHASHI (Grad. Sch. Sci., Hiroshima Univ.)382

Kaoru TAKAKURA (Div. Natural Sci., Int. Chr. Univ.)
Atsushi TAKEDA (Sch. Pharm. Sci., Univ. Shizuoka)
Haruna TAMANO (Sch. Pharm. Sci., Univ. Shizuoka)
Tadayasu TOGAWA (Meiji Pharm. Univ.)
Takehiro TOMITANI (Natl. Inst. Radiol. Sci.)
Shigeo UCHIDA (Natl. Inst. Radiol. Sci.)
Kohshin WASHIYAMA (Fac. Med., Kanazawa Univ.)
Mineo YAMASAKI (Nara Med. Univ.)
Makoto YANAGA (Fac. Sci., Shizuoka Univ.)
Hiroyuki YASUI (Kyoto Pharm. Univ.)
Akihiko YOKOYAMA (Fac. Sci., Kanazawa Univ.)
Shigekazu YONEDA (Natl. Sci. Museum)Shozo YOSHIDA (Nara Med. Univ.)
Takashi YOSHIMURA (Grad. Sch. Sci., Osaka Univ.)
Trainees
Yusuke ADACHI (Kyoto Pharm. Univ.)
Jun FUGONO (Kyoto Pharm. Univ.)
Jun FURUKAWA (Grad. Sch. Agr. Life Sci., Univ. Tokyo)
Hiroko HASEGAWA (Grad. Sch. Sci., Osaka Univ.)
Ryoichi HIRAYAMA (Grad. Sch. Sci. Tech., Chiba Univ.)
Kenichi ISHIBASHI (Meiji Pharm. Univ.)
Yoshiharu ISOBE (Dept. Radiol. Sci., Ibaraki Pref. Univ.)
Yoshiyuki KAJITA (Fac. Sci., Shizuoka Univ.)
Yousuke KANAYANA (Grad. Sch. Med. Sci., Kanazawa Univ.)
Yoshitaka KASAMATSU (Grad. Sch. Sci., Osaka Univ.)
Nobuyuki KINUGAWA (Grad. Sch. Sci. Technol., Shizuoka Univ.)
Keiji MATSUO (Sch. Sci., Osaka Univ.)
Tsutomu MATSUO (Fac. Sci. Eng., Waseda Univ.)
Ryuji MINAYOSHI (Fac. Sci., Shizuoka Univ.)
Aiko NARUTO (Fac. Life Sci., Tokyo Univ. Pharm. Life Sci.)
Takanori OGI (Grad. Sch. Sci. Technol., Shizuoka Univ.)
Shigeki OHATA (Meiji Pharm. Univ.)
Toshitaka OKA (Fac. Sci. Eng., Waseda Univ.)
Daisuke SAIKA (Sch. Sci., Osaka Univ.)
Naoko SATOU (Meiji Pharm. Univ.)
Momoko TAKAHASHI (Div. Natural Sci., Int. Chr. Univ.)
Yuuki TANI (Grad. Sch. Sci., Osaka Univ.)
Takae TSUJI (Grad. Sch. Med. Sci., Kanazawa Univ.)
Makoto YATSUKAWA (Grad. Sch. Sci., Osaka Univ.)
Hideaki YOSHIDA (Fac. Sci. Eng., Waseda Univ.)
Liquid Helium Service Division
Head
Yasushige YANOMembers
Kumio IKEGAMI
Hiroki OKUNO
Ken-ichi KATO∗2∗1∗2

Masao OTAKE
Toshiharu TOMINAKA∗1
Kazushiro NAKANO∗2

Contract Researcher
Temporary Employee

Visiting Members
Toshiyuki MITO (Jpn. Nucl. Cycle Dev. Inst.)

383

ADVANCED DEVELOPMENT AND SUPPORTING CENTER
Planning and Promotion Team
Head
Katsumi SENOOMembers
Yuji IKEGAMI
Yoshio NOMIYA
Susumu SHIMODA
Seigo SUGAHARA
Teruo URAI
Yutaka YAMADA

Tokuji KITSUNAI
Tsunenobu SHIGA
Akira SHIRAISHI
Norio TAJIMA
Shogo YAMADA

Contract Members
Naoe KANEKO
Akira MATSUMOTO
Tetsuji SASAMOTO
Saburo TOKIWA
Tokuji WATANABE

Ushizo KUBO
Yuzo NIIOKA
Kiyoji TAKAHASHI
Sumio YAMAMOTO

Beam Application Team
Head
Masaya IWAKI
Members
Tomohiro KOBAYASHI
Kowashi WATANABE

Aiko NAKAORESEARCH UNIT
Image Information Research Unit
Head
Hirohiko M. SHIMIZU
Members
Hiromi SATO
Yoshiyuki TAKIZAWA∗2
Tomohiro ADACHI∗2
Kazuaki IKEDA∗2
Mario E. BERTAINA∗2∗1∗2

Shigetomo SHIKI∗1
Masahiko KURAKADO∗2
Takahiro MORISHIMA∗2
Takenao SHINOHARA∗2

Special Postdoctoral Researcher
Contract Researcher

Visiting Members
Seiichirou ARIYOSHI (Grad. Univ. Adv. Stud.)
Tadashi KIFUNE (Fac. Eng., Shinshu Univ.)
Hiroaki MYOREN (Fac. Eng., Saitama Univ.)
Takayuki OKU (JAERI)
Kenji SAKAI (Dept. Phys., Tokyo Inst. Technol.)
Tohru TAINO (Fac. Eng., Saitama Univ.)
Fuyuki TOKANAI (Dept. Phys., Yamagata Univ.)
Trainees
Kouichi HOSHINO (Dept. Electr. Syst., Saitama Univ.)

384

RIKEN BNL Research Center
Head
Tsung-Dao LEE (Director)
Nicholas P. SAMIOS (Deputy Director)
Hideto EN’YO (RBRC Associate Director)
Experimental
Group Leader
Hideto EN’YO
Deputy Group Leader
Gerry M. BUNCE
Members
Yuji GOTO
Atsushi TAKETANI
Kiyoshi TANIDA
Abhay DESHPANDE∗1
Matthias GROSS PERDEKAMP∗2
Hisayuki TORII∗4
Osamu JINNOUCHI∗3
Brendan FOX∗1

Takashi ICHIHARA
Yasushi WATANABE
Yasuyuki AKIBA
Douglas Edward FIELDS∗2
Masashi KANETA∗3
Tsuguchika TABARU∗4
Kensuke OKADA∗3
Hideyuki KOBAYASHI∗4

Visiting Members
Yoshinori FUKAO (Kyoto Univ.)
Takuma HORAGUCHI (Tokyo Inst. Technol.)Kazuyoshi KURITA (Rikkyo Univ.)
Naohito SAITO (Kyoto Univ.)
Zheng LEE (BNL, USA)
Vikor SIEGLE (Univ. Heidelberg, Germany)Jens S. LANGE (BNL, USA)
Akio OGAWA (BNL, USA)
TheoryGroup Leader
Tsung-Dao LEE
Deputy Group Leader
Anthony J. BALTZMembers
Steﬀen A. BASS∗2
Takashi IKEDA∗4
Yasumichi AOKI∗3
Thomas BLUM∗1
Sangyong JEON∗2
Yukio NEMOTO∗3
Stefan KRETZER∗3
Mikhail A. STEPHANOV∗2
Ubirajara van KOLCK∗2
Tilo WETTIG∗2
Norikazu YAMADA∗3

Christopher DAWSON∗1
Tetsufumi HIRANO∗4
Kazunori ITAKURA∗3
Rajagopal VENUGOPALAN∗2
Alexander KUSENKO∗2
Jun-ichi NOAKI∗3
Thomas SCHAEFER∗2
Takanori SUGIHARA∗4Peter PETRECZKY∗1
Werner VOGELSANG∗1
Taku IZUBUCHI∗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)385

Shigemi OHTA (KEK)
Hiroshi YOKOYA (Hiroshima Univ.)
Yoshitaka HATTA (Kyoto Univ.)
Konstantinos ORGINOS (Massachusetts Inst. Technol., USA)
Administration
Pamela ESPOSITO (Secretary)
Rae GREENBERG (Assistant)
Tammy Anne HEINZ (Secretary)
Taeko ITO (Secretary)
Administrative Manager
Kiyofumi TSUTSUMI
Motohide YOKOTA
Deputy Administrative Manager
Chiharu SHIMOYAMADA∗1∗3

RIKEN BNL Fellow, ∗2 RHIC Physics Fellow,
Research Associate, ∗4 Special Postdoctoral Researcher

SAFETY DIVISION
Head
Hiroshi SAWA
Deputy Director
Masayuki SHIMAGAKI
Makoto MIYAGAWA
Laboratory Safety Section
Head
Yoshitomo UWAMINO
Members
Hajime YOSHIKI
Kunio FUKASAWA

Nobuyasu YAMAGISHI

Research Ethics Section
Head
Satoru KAGAYA
Members
Akira OZAKI
Hiroko KATOU

386

Shigemi SHINOHARA
Mika SUZUKI

Back to Contents

AUTHOR INDEXABE Tomoko

113, 147, 148, 149, 150, 151, 152

BOYLE Peter A.

221

ABU-IBRAHIM Badawy

30

BRÜCHLE Willy

130

ADACHI Tadashi

足立

匡

110

BRAVAR Allessandro

ADACHI Yusuke

安達祐介

117

BROWN B. Alex

17

AIDALA Christine

229

BROWN David S.

225

阿部知子

AIHARA Toshimitsu

藍原利光

3, 265, 267, 269

BUENKER Robert J.

AKAISHI Yoshinori

赤石義紀

34

BUNCE Gerry

AKEMANN Gernot

211

AKIBA Yasuyuki

秋葉康之

94

222, 243, 245

CAMARD Xavier
232, 234, 236, 249, 251, 254

243, 245

240

CASARES Antonio

163

AKIYAMA Kazuhiko

秋山和彦

130

CHELNOKOV Maxim L.

AKIYAMA Takahiro

秋山隆宏

159

CHEN Dong

秋吉啓充

47, 48, 49, 62

AKIYOSHI Hiromichi
ALEKSEEV Igor G.
AMANO Ryohei

245

ANDO Kozo

雨宮

宏

安藤嘉章

AOI Nori

考

青井

CHIBA Masami

千葉将允

70

CHIBA Yoshiaki

千葉好明

308

CHIMI Yasuhiro

知見康弘

97

CHRIST Norman H.
CHUJO Tatsuya

47, 48, 66, 69

221
224

CLARK Michael221

57, 58, 59, 60, 62, 63, 66, 69, 76,

COHEN Sid D.

221

77, 78, 153

CRISTIAN Calin

251, 255
220

青木保道

ARAI Masato

新井理太

134

ARIMA Akito

有馬朗人

24, 25ASAHI Koichiro

旭

耕一郎

221

d’ENTERRIA DavidDATTA Saumen
DAVID Gabor

240

212
240
出道仁彦

DESHPANDE Abhay

229, 246, 255, 256

171, 175

DHAWAN Satish

245

ASAI Keisuke

浅井圭介

99, 101

DINH DANG Nguyen

浅井雅人

130

DOMBRÁDI Zsolt

ASANO Nagayoshi

浅野長祥

118

DONG Zhihua

AZUMA Toshiyuki

東 俊行

95

DOTÉ Akinobu

馬場秀忠

BAKER Mark D.
BAKULE Pavel

BAUER FrankDUDNIK Oleksiy Volodimirovich

56, 57, 58, 59, 60, 61, 62,

DZORDZHADZE Vasily

63, 64, 66, 68, 69, 72, 74,

EATON Gordon H.

91

75, 76, 77, 78, 155, 187

EBIHARA Chiaki

海老原千晶

ELEKES Zoltán

168

224
118

46, 53, 54, 55, 56, 61, 63, 66, 69, 76,
77, 78

255
204

229

BAZILEVSKY Alexander
BAZIN Daniel

34

土手昭伸

46, 48, 49, 50, 53, 54, 55,

254

BASS Steﬀen A.

24, 2553, 54, 56, 61

221

176

BARISH Kenneth

46, 53, 56, 62, 66, 69, 76

DEMICHI Kimihiko71, 79, 112, 160, 161, 170,

ASAI Masato

BABA Hidetada

235, 237

中條達也

CIANCIOLO Vince

44, 46, 47, 48, 49, 50, 53, 55, 56,

青木和也

AOKI Yasumichi

36, 37, 38, 39, 40

103

安藤剛三

ANDO Yoshiaki

AOKI Kazuya

116, 135

天野良平

AMEMIYA Hiroshi

41, 42, 43

221

EMORI Shoken

江守昭憲

71, 160, 171, 175

EMOTO Takashi

江本81, 179, 291

EN’YO Hideto

延與秀人

隆

ENOMOTO Shuichi

50, 59, 60

85, 86, 87, 222, 232, 249, 251,257

229, 231

榎本秀一

113, 114, 115, 116, 117,BEAUMEL Didier55, 63

118, 119, 120, 121, 122,

BENTZ Wolfgang

32, 33123, 124, 125, 127, 128,

BHANG Hyeon-Chang

84

BLUMENFELD Yorick55, 63

BOGDANOV Dmitri D.

41

BOYD Richard N.

67

130, 132, 134, 135, 136,
137, 138, 139, 141
EREMIN Vladimir
ESUMI Shinichi

251

江角晋一

226

i

FÜLÖP Zsolt

47, 48, 53, 54, 56, 61, 64, 66, 69

FAMIANO Michael A.
FANG Deqing

67
清

248

FOMICHEV Andrey S.
FOX Brendan

GUIMARÃES Valdir51, 52, 70, 159

方FIELDS Douglas E.

HABA Hiromitsu

41, 42, 43

135, 136, 263

84

HAHN Kevin Inskik

64

204

HAMAGAKI Hideki

浜垣秀樹

117

畚野 純

FUJII Makiko

藤井まき子

118

FUJII Masashi

藤井雅史

168

FUJII Shinichiro

22, 23

藤井新一郎

浜垣

学

177

浜中廣見

191

HANAOKA Fumio

花岡文雄

HARA Mitsuo

原

光雄

長谷部裕雄

藤巻正樹

3, 5, 275, 277, 279

HASEBE Hiroo

藤縄 雅

7, 285, 289

HASEBE Nobuyuki

藤島史郎

FUJITA Shin

新

藤田

285

240, 257

HAMANAKA Hiromi

FUJINAWA Tadashi
FUJISHIMA Shiro崇HAMAGAKI Manabu

FUJIMAKI Masaki

143, 144

263
3, 7, 283
193

長谷部信行

HASEGAWA Hirokazu

60, 62, 66, 69, 76

藤原康平

249

HASEGAWA Kenichi

FUKAO Yoshinori

深尾祥紀

229, 246, 251

HASEYAMA Tomohito

深沢泰司

88

HASHIMOTO Koichi

福地知則

46, 64, 74, 75, 77, 78, 79

HASHIMOTO Tomonori

FUKUDA Mitsunori

福田光順

51, 5250, 53, 55, 59, 60, 62, 63,

福西暢尚

FUKUYAMA Yoshimitsu

216

橋本耕一

HASUKO Kazumi

蓮子和巳

259, 260, 261

HATANO Michio

波田野道夫

44, 181

HATTA Yoshitaka

八田佳孝

205

HAYANO Ryugo S.

早野龍五

84, 156

145, 146, 273, 276,

HAYASHI Takeshi

林

84283, 285

HE Jianjun

福山祥光

173

何

HEMMI Masatake

剛史

64, 65, 68, 72, 75

建軍

3, 275

逸見政武

FUKUZAWA Seiji

福澤聖児

5

HEUSER Johann M.

FUTAKAMI Udai

二上宇内

66, 69HIGURASHI Yoshihide

249, 250, 251, 254
3, 5, 47, 48, 49, 62,

日暮祥英

221

GEISSEL Hans

66, 69, 265, 267, 269

156

GELBERG Adrian
GIBELIN Julien

53

54, 55, 56, 61, 63, 76

GILLITZER Albrecht
GLENN Andrew
GOKA Tateo

156

224

五家建夫

GOLOVKOV Mikhail S.
GOMI Tomoko

HIRAI Masaaki

平井正明

47, 48HIRAI Masanori

平井正紀

197

HIRAI Toshiyuki

平井利幸

130

HIRAMOTO Takuji

平本卓嗣

193

HIRANO Tetsufumi

平野哲文

203

168

HIRASAWA Masahiko

平澤雅彦

41, 42, 43

HIRATA Masaru

勝

46, 47, 48, 49, 50, 53, 55, 56,

五味朋子

平田

HIRUNUMA Rieko

GOMIKAWA Kenji

五味川健治

113, 114, 115, 117,

蛭沼利江子

郷内

GONO Yasuyuki

郷農靖之

武

119, 120, 123, 132,

84, 156

152

GONAI Takeru

141

130

59, 60, 62, 63, 66, 69, 76

135, 136, 139
HOKOIWA Naho

鉾岩奈穂

64, 68, 75

本間謙輔

239

64, 68, 75, 79, 136, 137,

HOMMA Kensuke

138, 141

HONDA Ichiro

本多一郎

149

HONG Soojing

洪秀徴

88, 167

GORSHKOV Vladimir A.

41

HONMA Michio

本間道雄

17, 19GOTO Akira

3, 5, 276, 283, 284, 285, 287

HORAGUCHI Takuma

洞口拓磨

HORIKAWA Tai

敦

GORIELY Stephane
後藤

GOTO Shin-ichi

ii

134

橋本知典

3, 5, 95, 143, 144,

66, 69FUKUNISHI Nobuhisa

71, 161, 171, 175

長谷山智仁

FUKUCHI Tomonori

福田直樹

191

長谷川賢一

FUKAZAWA Yasushi

GOTO Yuji

46, 50, 53, 56, 59,

長谷川浩一

281, 317

FUJIWARA Kohei

GARA Alan

236

蜂谷

FUGONO Jun

FUKUDA Naoki

80, 111, 113, 114, 117, 120,

羽場宏光

HACHIYA Takashi

FRANKLIN Gregg

223, 255, 259, 260

65122, 123, 128, 130, 132,

229, 231, 246

FRIES Rainer J.

GROSSE PERDEKAMP Matthias

27
彰

後藤真一

後藤雄二

80, 130

堀川

229, 231, 232, 246, 249, 251,

HORIOKA Kazuhiko254, 257

HORIUCHI Hisashi

229, 234

32

堀岡一彦
堀内 昶

264
14

HORVÁTH Ákos

54, 61HOSAKA Atsushi

保坂 淳

HOSHINO Masamitsu

ITO Makoto

細井基興

HOSTEINS Pierre

173

ICHIHARA Takashi

市原

ICHIKAWA Shin-ichi

市川進一

ICHIKAWA Yuichi

卓

151

伊藤祐司

44, 45, 82

伊藤圭介

103, 104

岩井良夫

46, 47, 48, 49, 51, 52, 54,

岩佐直仁

189, 257

57, 58, 61, 62, 66, 69, 77,

130

78

44, 54, 61, 77, 78, 153

IWASA Tsutomu

46, 54, 61, 74, 75, 80, 301

IWASAKI Hironori

市川雄一

井手口栄治

岩佐

317

力

44, 46, 47, 48, 49, 53, 54,

岩崎弘典

48, 49, 66, 69, 187

家城和夫

IGARASHI Kaori

317

IWASA Naohito

245

IDEGUCHI Eiji

281, 317

伊藤寿二

IWAI Yoshio

245

HUGHES Vernon

伊藤祥子

ITO Toshiji
ITOH Keisuke

67

128

伊藤正之

ITO Sachiko
ITO Yuji

HOWARD Meredith E.

IEKI Kazuo

105

159

12, 15

伊藤 誠

ITO Masayuki

星野正光

HOSOI Motooki

HUANG Haixin

21

56, 57, 58, 61, 62, 64, 66,

113, 114, 115, 132, 136,

五十嵐香織

68, 69, 74, 75, 76, 77, 78,

139
IGO George
IIDA Kei

153, 155

245

IWASAKI Masahiko
30

飯田 圭

IIYAMA Masamitsu

IWASE Akihiro
125

飯山真充

97

岩瀬彰宏

IWATA Yoshiyuki

84, 90, 91, 109, 156, 176

岩崎雅彦

47, 48岩田佳之

IKEDA Kiyomi

池田清美

12, 13, 20, 21

IWAZAKI Aiichi

岩崎愛一

207

IKEDA Naomi

池田直美

98

IZAWA Masaaki

伊澤正陽

306

IKEDA Takashi

池田

208

IKEDA Takuichiro

貴IZUBUCHI Taku
44, 45, 82

池田拓一郎

95, 103, 104, 310

IKEDA Tokihiro

池田時浩

IKEGAMI Kumio

池上九三男

285

IZUMI Masako

出渕泉

216, 217

卓雅子

144, 145, 146

IZUMIKAWA Takuji

泉川卓司

JAYANTHI Udaya B.

167
相蓉51, 52, 159

IKEZAWA Eiji

池沢英二

3, 5, 7, 265, 273

JEON Sangyong

IMAI Ken’ichi

今井憲一

232, 243

JIA Jiangyong

賈

江湧

233

IMAI Nobuaki

今井伸明

47, 48, 49, 50, 53, 56, 59, 60,

JIMBO Shimon

神保志文

111

66, 69, 76, 153

JINNOUCHI Osamu

91

JOÓ Balint

IMAO Hiroshi

今尾浩士

INABE Naohito

3, 5, 98, 283, 285

稲辺尚人

INAMURA Takashi Thomas

稲村

INOUE Hokuto

井上北斗

88

INOUE Masato

井上正人

102

卓

263

銭

201

225, 243, 245, 247, 257

陣内 修

221

JUNG Chulwoo

221

KACZMAREK Olaf

212

KAGEYAMA Kensuke

蔭山健介

96
3, 5, 267

KAGEYAMA Tadashi

影山

石橋健一

120

KAJI Daiya

80, 132

ISHIDA Katsuhiko

石田勝彦

90, 91, 176

KAMADA Hiroyuki

鎌田裕之

22

ISHIDA Yoshihisa

石田佳久

163, 173

KAMBARA Tadashi

神原95, 96, 97, 105, 173

46, 47, 48, 49, 50, 53,

KAMEDA Daisuke

亀田大輔

56, 59, 60, 62, 66, 69,

KAMETANI Soichiro77, 78KAMEYA Toshiaki

ISHIBASHI Kenichi
ISHIDA Carolina

74

KAKUTANI Nobukazu

ISHIHARA Masayasu

石原正泰

ISHII Nobuyoshi

石井伸昌

124

ISHII Noriyoshi

石井理修

32, 33, 213

ISHIKAWA Katsutoshi
ISHIKAWA Kazuhiro
ISHIKAWA Norito
ISHIMOTO Shigeru
ISSHIKI Hiroshi

加治大哉

119
53, 55, 63, 66, 69, 84

石川和宏
石川法人

97

石元 茂

84

一色 博

5, 275

正71, 79, 112, 161, 171, 175
240

亀谷聡一朗

150

亀谷壽昭

上垣外修一

KAMIHARA Nobuyuki
KAMINAGA Shigeto
KANAI Yasuyuki

297, 299

角谷暢一

KAMIGAITO Osamu

石川勝利

正

神原信幸
神長誉人

金井保之

3, 5, 265, 284, 285
224

226

95, 96, 103, 104, 105, 173

KANAMITSU Hiroaki

金光裕昭

97

KANAYAMA Yousuke

金山洋介

135

KANEKO Emi

金子恵美

53

ITAGAKI Naoyuki

板垣直之

49

KANEKO Tetsuya

金子哲也

130

ITAHASHI Kenta

板橋健太

84, 90, 156

KANETA Masashi

金田雅司

238

iii

KANNO Akira

KIMURA Mineo

季村峯生

93, 94

KANNO Shouko

菅野祥子

46, 48, 49, 53, 56, 57, 58,

KIMURA Shuichi

木村修一

114, 115

61, 62, 66, 69, 76, 77, 78

KINOSHITA Norikazu

木下哲一

130, 134

KANO Hiroyuki

狩野博之

249, 253KINUGAWA Nobuyuki

衣川信之

119

菅野

KANUNGO Rituparna
KARSCH Frithjof150

明42, 43, 51, 52, 54, 61, 70, 77, 78,

KISHIDA Takashi

80

KITAZAWA Masakiyo
KIYOMICHI Akio

212

KASAMATSU Yoshitaka
KASE Masayuki

KOBAYASHI Hiroshi

小林 寛

47, 48267, 269, 273, 275, 277,

KOBAYASHI Kiyoshi

小林清志

5

279, 281, 283, 285, 289,

KOBAYASHI Masanori

小林正規

193

291, 310, 317

KOBAYASHI Tomohiro

小林知洋

9

79

KOBAYASHI Toshio

小林俊雄

50, 59, 60

152

KOBAYASHI Yoshio

小林義男

71, 79, 111, 112, 171, 175

樫山

霞 正一

修

12, 13277,
279,

264, 271, 308, 310, 314

291

84

片山武士

KATO Go

71, 171, 175

KOHAMA Akihisa

加藤 博

167, 168

KOHARA Shigeo

KATO Koichi

加藤公一

240

KOIDE Tomoi

加藤岑生

91

KOIKE Yoji

加藤礼三

109

KOIZUMI Tetsuo

KATO Seigo

加藤静吾

64, 65, 68, 75

KOJIMA Takao M.

70

KOKUBUN Motohide

80

鹿取謙二

KAWAGUCHI Takeo

310

川口武男

88

KAWAHARADA Madoka

川原田

KAWAI Shoko

54, 56, 61, 77, 78

円

206
110

小池洋二

107

小泉哲夫

KOKUSEN Hisao
44, 45, 82, 251

川畑貴裕

3, 5, 284

小原重夫

小出知威

KATO Reizo

KAWABATA Takahiro

167

小浜光洋

KATO Mineo

KATORI Kenji

31

小濱洋央

KOHAMA Mitsuhiro

KATO Hiroshi

加藤俊幸

96, 102, 173

小島隆夫

88

国分紀秀

125

國仙久雄

KOMAKI Ken-ichiro95, 102, 103

小牧研一郎

KOMATSU Seiji

小松征史

97

KOMATSU Yu

小松125, 127

優

KOMATSUBARA Tetsuro

小松原哲郎

KAWAKAMI Hirokane

川上宏金

173

KONDO Chikara

近藤

95

KAWAMOTO Kanichi

川本完一

289

KONDO Yousuke

近藤洋介

KAWAMURA Naritoshi

河村成肇

91

河合祥子

力

63, 66, 69, 84

河崎洋章

53

KONDOH Masuo

KAWASAKI Takeo

川崎健夫

249

KORSHENINNIKOV Alexey A.

KIDERA Masanori
KIJIMA Go

68, 75, 136, 137, 138

木部道也

KIKUCHI Kaori菊地KIKUCHI Takashi

KIM DongJo

小関

KOSHIMIZU Masanori

忠41, 42, 43

81, 179, 306, 308

越水正典

99, 101149

KOTOKU Jun’ichi

古徳純一

167

KOURA Hiroyuki

小浦寛之

11, 80

郁

264

菊永英寿

130, 134, 263

金 鍾贊

5

小高康照

KOUZU Hideo

神津秀雄

301

KOYAMA Ryo

小山 亮

51, 52KRATZ Jens Von

130

65

KRETZER Stefan

200

KUBO Kenya M.

久保謙哉

112

KUBO Toshiyuki

久保敏幸

50, 53, 55, 56, 59, 60, 63,

224

KIM So-YoungKOSEKI Tadashi
KOTAKA Yasuteru

221

KIM Jong Chan

118

近藤昌夫

71, 171, 175

菊池祟志

KIKUNAGA Hidetoshi
KIM Changhoan

3, 5, 265, 267, 269

木寺正憲

木島 剛

74

50, 53, 54, 55, 59, 60, 61,

KAWASAKI Hiroaki
KIBE Michiya

3, 5,

36, 37, 38, 39, 40, 107,

KATAYAMA Takeshi

KATO Toshiyuki

小林-込山美咲

KOBAYASHI-KOMIYAMA Misaki

片山武司

加藤 剛

225

小林秀幸

106, 173片山一郎

KATAYAMA Takeshi

235, 237, 257

清道明男

3, 5, 7, 98, 99, 101, 265,

KASUMI Masakazu

加藤幾芳

206

KOBAYASHI Hideyuki

KASHIYAMA Osamu
KATŌ Kiyoshi

53, 56, 75, 79

隆

北沢正清

134, 263

笠松良崇

加瀬昌之

KATAYAMA Ichiro

岸田

150

KIMURA Kazuie

木村一宇

99, 101

KIMURA Kikuo

木村喜久雄

159

66, 69, 74, 76, 77, 78, 173,

KIMURA Masaaki

木村真明

14

293, 295, 297, 299, 301,iv

303, 305

MASUDA Hideki

103, 104

益田秀樹

KUBOKI Hironori

久保木浩功

44, 45

KUBONO Shigeru

久保野

46, 48, 49, 57, 58, 64,

MATSUDA Yasuyuki

松田恭幸

84, 90, 91, 176

65, 66, 68, 69, 72, 75,

MATSUFURU Hideo

松古栄夫

219

茂

MASUOKA Toshikatsu

MATSUI Nobuyuki

183
KUBOYAMA Satoshi
KUDO Hisaaki

80, 130

工藤久昭

KUMAGAI Keiko

98

久保山智司

291

熊谷桂子

291

益岡俊勝

44, 45

松井信行

MATSUMOTO Haruhisa

松本晴久

168

MATSUMOTO Takashi

松元貴志

240

MATSUO Yukari

163, 173松尾由賀利

KUNIBU Makoto

國分 誠

48, 49, 62, 66, 69

MATSUYAMA Tomoki

KUNIHIRO Teiji

国広悌二

206

MATSUYAMA Yuuichi U.

松山裕一

46, 48, 49, 56, 62,

65, 67,

MATSUZAKI Teiichiro

禎市郎

90, 91, 176

68, 72,MAWHINNEY Robert D.

75, 183

MESHKOV Igor

KURAKADO Masahiko

KURITA Kazuyoshi

倉田-西村美月

日下健祐

KUZMIN Evgueni A.

259, 260

LEE Chun-Sik

春植

LEE Eun Kyung

李LEE Ju-Hahn

李柱漢

LENZ Frieder

35

179, 243, 245, 247

64, 66, 68, 69,
72, 74, 75, 76,
MIKAMI Hideo

三神英夫

303, 305

MILLER Katie

46

MINEMURA Toshiyuki

64

33

峯尾浩文

MIODUSZEWSKI Saskia

240
三頭聰明

MITSUMOTO Toshinori

221

221

LINDBERG Karl

46, 47, 48, 49, 53,

峯村俊行

66, 69, 76
MINEO Hirobumi

64, 65, 68

65

55, 63

LIU Guo-Feng

285

56, 57, 58, 62, 64,

LIHITENTHALER Rubens Filho
LIMA Victor

77, 78, 155

293, 295, 297, 299, 301,

64, 65, 68

恩敬

46, 48, 49, 53,
56, 57, 58, 62,245, 249, 251

LIAO Xiaodong

道正新一郎

MITSUGASHIRA Toshiaki

LEVKOVA Ludmila
LI Zheng

MICHIMASA Shin’ichiro69, 76, 77, 78, 81, 161,

41, 42, 43

LANGE Jens Soeren
李

221

314

46, 48, 57, 58, 62, 74

黒川明子

KUSAKA Kensuke

松

299

栗山 透

KUROKAWA Meiko66, 69, 76

46, 53, 56, 57, 58, 66,

栗田和好

KURIYAMA Toru

157

倉門雅彦

KURATA-NISHIMURA Mizuki

147

松山知樹

156

221

MITTIG Wolfgang

41, 42, 43

MIURA Motooki

三浦元隆

263

285

密本俊典

50, 53, 59, 60, 66, 69

MIYACHI Takashi

宮地 孝

193

MIYAKE Yasuhiro

三宅康博

176

MIYAMOTO Yutaka

宮本ユタカ

130

MIYASAKA Hiromasa

宮坂浩正

88, 167

劉 忠

47, 48MIYAZAWA Yoshitoshi

LOZOWSKI William

245

MIYAZAWA Yutaka宮沢豊

113, 149, 150, 151, 152

MIYOSHI Hisanori

三好永哲

71, 79, 112, 161, 171, 175

LIU ZhongMÖHL Dieter

314

MÜLLER Berndt

MIZOI Yutaka

204
245

MADOKORO Hideki

間所秀樹

MADZUNKOV Stojan

105

28

MIZUSAKI Takahiro

毛利明博

102

門間茂樹

299

191

MONMA Shigeki

前田幸重

44, 45

MOON Jun Young

MAIE Takeshi

真家武士

5, 7

前田邦子

MAKIMURA Shunsuke
MAKISHIMA Kazuo

MAKOCHEKANWA Casten

森川恒安

79

207

森松

176

MORIMOTO Kouji

森本幸司

42, 43, 70, 74, 80

88, 167

MORISHIMA Yuki

森島由紀

98

93

MALYKHINA Tetyana Vasylivna

64, 65, 68, 75

俊永

MORIMATSU Osamu
牧村俊助

牧島一夫

文

MORIKAWA Tsuneyasu

243

17, 19水崎高浩

MOHRI Akihiro

MAEDA Yukie

MAKDISI Yousef I.

62, 293, 295, 297, 299, 301,

溝井 浩

303, 305

MACKAY William W.

MAEDA Kuniko

285

宮澤佳敏

168

治

MORITA Kosuke

森田浩介

80

MOTIZUKI Yuko

望月優子

27, 28v

MOTOBAYASHI Tohru

MOTOMURA Shinji

本林透

1, 46, 47, 48, 49, 50,

NODA Koji

53, 54, 55, 56, 57,

NOGUCHI Motoko

173

野田耕司

119

野口基子

58, 59, 60, 61, 62,

NONAKA Chiho

野中千穂

204

63, 66, 69, 76, 77,

NORO Yoshihiko

野呂良彦

111

78

NOTANI Masahiro

46, 53, 54, 56, 57, 58, 61,

野谷将広

79, 136, 137, 138, 139,

本村信治

62, 64, 65, 66, 68, 69, 72,

141

75, 76

MURAKAMI Hiroyuki

村上浩之

47, 66, 69

ODAGIRI Jun-ichi

小田切淳一

277

MURAKAMI Tetsuya

村上哲也

46

ODAHARA Atsuko

小田原厚子

46, 64, 75, 79, 136,

MURAO Satoshi

191

村尾 智

MURASAWA Satoshi
MURATA Jiro

OGANESSIAN Yuri Ts.

41

OGAWA Akio

259, 26085, 86, 87

OGAWA Yoko

小川洋子

21

OGI Takanori

小木貴憲

119

哲

MUTO Ryotaro

武藤亮太郎

MYO Takayuki

明

13

孝之

NAGAME Yuichiro

130

永目諭一郎

NAGAMINE Kanetada
NAGASE Makoto

90, 91, 110, 176

永嶺謙忠

3, 5, 273

長瀬 誠

NAGASHIMA Atsushi
NAGATA Yujiro

193

71, 161, 171, 175

村澤

村田次郎

137, 138

永島敦

OGILVIE Craig A.

254

OGIWARA Kiyoshi

荻原

OGLOBLIN Alexey A.

193

OHATA Shigeki
OHIRA Seiko

111

永田勇二郎

小川暁生

OHIRA Hideharu

120
98

大平秀春

中川孝秀

3, 5, 265, 267, 269

NAKAHARA Hiromichi

中原弘道

130

OHKI Tomonori

NAKAI Yoichi

95, 96, 103, 104, 173

OHNISHI Hiroaki

中井陽一

41, 42, 43

大畑茂樹

NAKAGAWA Takahide

9

清

109

大平聖子

3

大木智則

89, 249, 251, 254

大西宏明

NAKAJIMA Mitsuo

中島充夫

264

OHNISHI Jun-ichi

大西純一

285, 287

NAKAJIMA Motoki

中島基樹

167

OHNISHI Tetsuya

大西哲哉

44, 51, 52, 54, 56, 61, 70,

NAKAJIMA Noriaki

中島典昭

219
大野雅功

88

74, 80, 81, 159, 179

NAKAMURA Takashi

中村貴志

106, 173

OHNO Masanori

NAKAMURA Takashi

中村隆司

48, 49, 50, 53, 55, 59,

OHSEMOCHI Koichi

大勢持光一

299

60, 62, 63, 66, 69, 84

OHSHIRO Yukimitsu

大城幸光

5, 271NAKAMURA Takeshi

仲村武志

317

OHTA Koichi

太田浩一

35

NAKAMURA Tomoaki

中村智昭

239

OHTA Ryuichi

太田隆一

5

太田滋生

220, 221

NAKANISHI Takashi

中西 孝

263

OHTA Shigemi

NAKAYAMA Akihiro

中山明弘

117, 121, 122

OHTANI Munehisa

大谷宗久

207

NARA Yasushi

寧

OHTANI Shunsuke

大谷俊介

106, 173

OHTOMO Kiyotaka

大友清隆

308
51, 52, 159

奈良

NARUKI Megumi

成木

NARUTO Aiko

成戸愛子

203
85, 86, 87

恵145

OHTSUBO Takashi

大坪

NEMOTO Yukio

根本幸雄

206, 214, 219

OHTSUKI Tsutomu

大槻 勤

NIIGAKI Megumi

新垣

恵

102

OHYAMA Takuya

NIIKURA Megumi

新倉潤

74, 77, 78, 155

NIKOLSKII Evgueni Yu.

41, 42, 43

NINOMIYA Kazuhiko

二宮和彦

NISHI Yuji

67

西

勇二

NISHIDA Minoru

西田

NISHIKAWA Tetsuo

稔

134

OI Makito

岡OKADA Hiromi

5, 275

OKADA Kensuke

岡田謙介

229, 231, 233

207

OKADA Kunihiro

岡田邦宏

106, 173

西村俊二

65, 67, 68, 72, 75, 183

OKADA Shinji

西中一朗

130

OKADA Takuya

岡田信二

NISHINO Haruki

西野玄記

78

OKAMOTO Ryoji

西尾和人

120

OKAMURA Hiroyuki

vi103, 104
218

84
111

岡田卓也

NISHIO Kazuto

西尾和之

243, 251

岡田裕美

193

西川哲夫

野秋淳一

98

岡田宏之

NISHIMURA Shunji

NISHIO Kazuyuki

26

克己

OKADA Hiroyuki

NISHINAKA Ichiro

NOAKI Jun-Ichi

263
119

大山拓也

大井万紀人

OKA Katsumi

隆

岡本良治

OKAMURA Masahiro
OKUDAIRA Osamu

22, 23

岡村弘之
岡村昌宏
奥平

修

44, 276
107, 241
193

OKUNO Hiroki
ONG Hooi Jin

王

ONISHI Takeo K.
ONO Fumihisa
ONO Mari

惠仁

OTA Shinsuke

SAKAI Hazuki K.

酒井葉月

48, 56酒井英行

44, 45, 82, 181

SAKAI Kenji

102, 173

大島永康

46, 56, 57, 58, 66, 69, 74, 76,

大田晋輔

阪間

SAKAMOTO Hisao

220

130

稔

281, 317

坂本久雄

坂本成彦

SAKAMOTO Yasunobu

坂本泰伸

SAKUMA Fuminori

77, 78, 155

SAKURAGI Yukinori

98

SAKURAI Hiromu

OTSUKA Takaharu

大塚孝治

17, 18, 19

SAKURAI Hiroyoshi

187
85, 86, 87, 251

佐久間史典

大友洋光

15, 16

櫻木千典

117

桜井 弘

46, 47, 48, 49, 50, 53,

櫻井博儀

130

大浦泰嗣

3, 5, 44, 276, 284, 285

SAKAMOTO Naruhiko

OTOMO Hiromitsu
OURA Yasuji

175

酒井健二

SAKAMA Minoru
130

小野佐和子

240

坂口貴男

SAKAI Hideyuki

116

ORGINOS Konstantinos

79

斎藤浩司

44, 53, 76, 77, 78, 153

97

小野文久

SAITOH Kohji

SAKAGUCHI Takao

53, 56, 57, 58, 76, 77, 78, 153

大西健夫

OSHIMA Nagayasu

303, 305

奥山利久

大野真里

ONO Sawako

3, 5, 285, 287

奥野広樹

OKUYAMA Toshihisa

54, 56, 57, 58, 59, 60,

OUTA Haruhiko

應田治彦

84

61, 62, 66, 69, 76, 77,

OYAMA Hitoshi

大山 等103, 17378, 153OYAMA Ken

240

大山 健

OYAMADA Kazuyuki
OYAMATSU Kazuhiro
OZAWA Akira

小沢

SAKURAI Ikuya

小山田和幸

3, 7, 275

親松和浩

30

74, 76, 80, 159
OZAWA Kyoichiro
OZAWA Shuichi

240

小沢恭一郎
小澤修一

47, 48, 107, 177

PERSIKOV Valentin Kostyantinovich
PETER Jaen C.

168

80

64

佐々木隆文

SASAKI Yuichirou

42, 43, 51, 52, 54, 56, 61, 70,

顕

167

桜井郁也

SASAKI Takafumi

310

佐々木雄一朗SASANO Masaki

笹野匡紀

44, 45

SATO Hiroki D.

佐藤博紀

224

SATO Hiroki

佐藤裕樹

98

SATO Hiromi

佐藤広海

157

SATO Kiyokazu

佐藤潔和

297

SATO Masaharu

佐藤将春

84

PETRECZKY Peter

212

SATO Naoko

佐藤尚子

120

PETROV Konstantin

212, 221

SATO Wataru

佐藤 渉

79, 134POLLACCO Emanuel42, 43

SATOU Yoshiteru

佐藤義輝

PURSCHKE Martin L.

240

SAVAJOLS Herve41, 42, 43

SCHÄFER Thomas202

QUINN Brian84

RADEKA Veljko
READ Ken

251

224

REITZNER DianeRESCIA Sergio

67

245

RODIN Aleksander M.
ROSER Thomas

41, 42, 43

245

ROUSSEL-CHOMAZ Patricia

41, 42, 43

RYKOV Vladimir L.

232, 249, 251, 254

RYUTO Hiromichi

龍頭啓充

3, 5, 143, 144, 146, 276,

齋藤明登

130

SCHUCH Reinhold

105
44, 45, 276

SEKIGUCHI Kimiko

関口仁子

SEKIMOTO Michiko

関本美知子

125

SEKITA Masami

関田正實

SERATA Masaki

世良田真来

SHEN Hong

251

47, 48, 49, 62, 66, 69, 107

21

SHIBAMURA Eido
SHIBATA Sadao

193

柴村英道

柴田貞夫

134, 141SHIBATA Toshi-Aki

柴田利明

224

46, 48, 49, 50, 53, 55, 56, 57,

SHIBUSAWA Satoshi

渋沢

哲

134

58, 59, 60, 62, 63, 66, 69, 76,

SHIGEKAWA Mitsuru

重川

充

130

77, 78SHIKI Shigetomo

志岐成友

157

283, 285
SAITO Akito

SCHÄDEL Matthias

44, 45, 55, 63, 77, 78

SAITO Hiroyuki

斎藤宏之

149, 150SHIMADA Kenzi

島田健司

71, 161, 171, 175

SAITO Hiroyuki

斉藤宏之

113, 147, 151, 152

SHIMADA Osamu

島田

修

98

SAITO Naohito

齊藤直人

232, 243, 245, 246, 249, 251,SHIMAMURA Isao

島村 勲

94

255

SHIMIZU Hirohiko M.

SAITO Shota
SAITO Takaaki

齋藤翔太
齋藤孝明

247
44, 45, 82

清水裕彦

SHIMIZU Hiroshi

清水

洋

128

SHIMIZU Noritaka

清水則孝

18

157

vii

SHIMIZU Tetsuya

SHIMOURA Susumu

SHINDO Miki

28

清水鉄也

SHIMOMURA Koichiro

TABARU Tsuguchika

下村浩一郎
下浦

享

176

橘

46, 47, 48, 49, 50, 53,

TAGAMI Keiko54, 56, 57, 58, 59, 60,

TAKAHASHI Katsuhiko
TAKAHASHI Kazuya

75, 76, 77, 78, 155,

TAKAHASHI Masa

187

TAKAHASHI Naruto

27

孝博

123, 124

田上恵子

61, 62, 64, 66, 69, 74,

84, 156

進藤美紀

85, 86, 87, 249, 251

田原司睦

TACHIBANA Takahiro

5

高橋克彦

119

高橋和也
聖

51, 52

高橋成人

134

高橋

TAKAHASHI Tadayuki

88

高橋忠幸

SHINOHARA Atsushi

篠原厚130, 134, 263

TAKAHASHI Yoshio

高橋嘉夫

128

SHINOZAKI Wakako

篠崎和佳子

51, 52, 159

TAKAHASHI Yutaka

高橋

295

SIDORCHUK Sergey I.
SIEGLE Viktor

41

259, 260

TAKANAKA Masao

SMITH Edward E.

TAKANO Junpei

314

67

84

SONODA Tetsu

園田

SPINKA Harold

245

173

哲

195, 205

SUDA Toshimi

312

241

TAKASHINA Masaaki

高階正彰

15, 16TAKATSU Yasumasa

高津康正

152

高柳俊伸

139, 140
46, 48, 49, 53, 54, 55, 56,

竹下英里

57, 58, 61, 62, 63, 66, 69,

51, 52, 70, 74, 80, 81, 179

須藤和敬

113, 136, 137, 138,

竹市博臣

44, 45

須田利美

106

81, 179

竹田浩之

TAKESHITA Eri

84, 90, 176

須田健嗣

SUDOH Kazutaka

仲政雄

TAKEICHI Hiroshige

41

SUDA Kenji

263

高野淳平

TAKEDA Hiroyuki

STEPHANOV Mikhail A.
STRASSER Patrick

高宮幸一

TAKAYANAGI Toshinobu

STEPANTSOV Sergey V.

173

高峰愛子

TAKAMIYA Koichi

SMIRNOV Alexandre
SO Hyoungyul

TAKAMINE Aiko

314

SIDORIN Anatoly

豊76, 77, 78

196

TAKETANI Atsushi

竹谷 篤

224, 225, 249, 251, 255

TAKEUCHI Satoshi

武内46, 47, 48, 49, 53, 54,

SUEKI Keisuke

末木啓介

80, 130SUGAI Hiroyuki

須貝宏行

91

聡

55, 56, 57, 58, 61, 62,

SUGANUMA Hideo

菅沼英夫

119

63, 66, 69, 76, 77, 78,

SUGANUMA Hideo

菅沼秀夫

213, 219187

SUGAWARA Kousuke

菅原浩介

159

TAKI Reiko

SUGIHARA Takanori

杉原崇憲

210

TAKISAWA Aiko

瀧

玲子

276
159

滝沢愛子

SUGIMOTO Satoru

杉本

聡

20, 21TAKIZAWA Yoshiyuki

SUGIMOTO Takashi

杉本崇50, 53, 59, 60, 62, 66,

TAKYU Toshio

69, 84TAMAGAWA Toru

玉川

徹

167

SUMIYOSHI Kohsuke

住吉光介

29

TAMAI Munetaka

玉井宗孝

240

TAMAKI Mitsuru

玉城 充

46, 53, 56, 57, 58, 64, 74,

SUNO Hiroya

94

数納広哉

SUZUKI Daisuke

鈴木大介

44

SUZUKI Hideyuki

鈴木英之

29

SUZUKI Hiroshi

鈴木

SUZUKI Kazunori

151

76, 77, 78, 155

77, 78, 153

宏

152

鈴木一典

157

滝澤慶之

武弓利雄

TAMENAGA Setsuo
TAMII Atsushi

21

為永節雄

民井 淳

TAMURA Masafumi

44, 45, 181
109

田村雅史

SUZUKI Kenji

鈴木賢二

22, 23

TANABE Shinzo

田辺信三

120

SUZUKI Ken

鈴木 謙

84

TANABE Toshiya

田辺敏也

277, 291

TANAKA Manobu

田中真伸

249

TANASE Masakazu

棚瀬正和

91

SUZUKI Masaru K.

鈴木

SUZUKI Noriyuki

鈴木教之

SUZUKI ShojiSUZUKI Takeshi

鈴木隆敏
鈴木

SUZUKI Toshihiro
SVIRIDA Dmitry N.
SYRESIN Evageny

viii

健

鈴木俊宏

245
314

53, 77, 78, 153
265

84

鈴木祥仁

SUZUKI Takatoshi

賢

TANEMOTO Tsuyoshi
84

TANIDA Kiyoshi

種本剛士

谷田 聖

51, 52, 61, 159
120

125

227, 228, 229, 246, 249,
251, 254

TANIGUCHI Takashi
TANIHATA Isao

谷口貴士

谷畑勇夫

111

41, 42, 43, 51, 52, 54, 61,
67, 70, 72, 74, 76, 80, 159,

163, 183, 295
TEGNER Per-Erik

156

TER-AKOPIAN Gurgen M.

WAKABAYASHI Yasuo

若林泰生

64, 75, 79

WAKASUGI Masanori

若杉昌徳

3, 5, 81, 107, 179

WAKUI Takashi

41, 42, 43

44, 181涌井崇志

TERADA Yukikatsu

寺田幸功

88, 167

WALKER Philip M.

26

TERANISHI Takashi

寺西46, 47, 48, 49, 55, 63,

WATANABE Ayako

渡部亜矢子

94

64, 65, 68, 72, 75

WATANABE Hiroshi

渡邉53, 71, 75, 79, 112,THIES Michael高161, 171, 175

35

THOMAS Antony Williams
TIMOFEYUK Natalia K.

WATANABE Isao

32, 33

栂野泰宏

54, 55, 56, 61, 63, 66,

TOGAWA Manabu

外川

TOGAWA Tadayasu

兎川忠靖

東城順治

TOKANAI Fuyuki
TOKI Hiroshi

渡辺真朗

308

69, 76, 77, 78

WATANABE Shigeo

渡辺茂夫

52

232, 246, 249, 251

WATANABE Shin-ichi

渡辺伸一

271, 310

120

WATANABE Tamaki

渡邉 環

310

249, 251, 254

WATANABE Yasushi

渡邊 康189, 249, 251, 257

学

42, 43, 80

20, 21, 29

博

TOMINAKA Toshiharu
TOMITA Masanori

144, 145, 146

TOMITANI Takehiro

富谷武浩

TOMONO Dai

大TORII Hiroyuki A.
TORII Hisayuki

103

鳥居寛之

TOYOSHIMA Atsushi

141

84229, 231, 238, 240

鳥井久行

130

豊嶋厚史

TSUCHIHASHI Takahiro
TSUJI Masamichi

285, 297

冨中利治

冨田雅典

友野

土橋隆博

WATANABE Yoshiteru

渡辺善照

118

WATANABE Yutaka X.

渡辺 裕

50, 59, 60

WEICK Helmut

156

WETTIG Tilo

211, 221WETZORKE Ines212

WHITTEN Chuck

245

WIDMANN Eberhard

84

WOLLNIK Hermann

163, 173WOLSKI Roman

297, 299

191

WOOD Jeﬀery

41
245

WOODY Craig

240, 254

TSUKADA Kazuaki

塚田和明

130

WU Cuie

翠娥

TSUKADA Teruyo

塚田晃代

144, 145, 146

XIE Wei

辻 正道

TSUKIORI Noritoshi

5

月居憲俊

51, 52, 54, 61, 159

255

XU Hushan

徐

瑚珊

80
毅

TSUKUI Masato

津久井正人

160, 171, 175

YAITA Tsuyoshi

矢板

TSURUGA Naoya

釣賀直哉

130

YAKO Kentaro

矢向謙太郎

TSURUSAKI Kazuma

筒井裕士

UCHIDA Shigeo

内田滋夫

78

薬師寺

崇

山田裕久

125, 127

123, 124

YAMADA Kazunari

山田一成

46, 47, 48, 49, 56, 62,

UCHIYAMA Akito

内山暁仁

3

YAMADA Norikazu

UE Koji

48, 49, 62, 64, 66, 69

YAMADA Shoichi

UENO Hideki

66, 69, 76, 187

71, 79, 112, 161, 170, 171, 175

上野秀樹

山田憲和

YAMADA Yasuhiro

215
29

山田章一
山田康洋

112

UENO Hirotaka

上野博隆

247

YAMAGUCHI Azusa

山口あづさ

UESAKA Meiko

上坂明子

47

YAMAGUCHI Kenichi

山口建一

UESAKA Tomohiro
UMETANI Shigeo
UTSUNO Yutaka

44, 45, 82, 181

YAMAGUCHI Takayuki

山口貴之

70, 156

YAMAGUCHI Yoshitaka

山口由高

51, 52, 54, 61, 70,

19

YAMAKA Shoichi

山家捷一

YAMAKI Tsutomu

八巻 務

245

159

宇都野 穣

UWAMINO Yoshitomo

上蓑義朋

van KOLCK Ubirajara

209

VARENTSOV Victor L.

165, 173

281, 317

YAMAMOTO Yoshiharu Y.

VINODKUMAR Attukalathil Mayyan
VOGELSANG Werner
WADA Michiharu

221
7125, 127

上坂友洋
梅谷重夫

UNDERWOOD David50, 59, 60

YAKUSHIJI Takashi

167

浩二

44, 45, 82

YAMADA Hirohisa

内堀幸夫

上

130

36, 37, 38, 39, 40, 308, 314

鶴崎一磨

TSUTSUI Hiroshi
UCHIHORI Yukio

50, 59, 60

渡辺極之

WATANABE Masao

門叶冬樹

土岐

109, 110

渡邊功雄

WATANABE Kiwamu

42, 43TOGANO Yasuhiro

TOJO Junji

寛

YAMANOUCHI Hiroaki
50, 55, 59, 63, 84

198, 199

和田道治

106, 163, 165, 173, 185

271
281, 317
山本義治

山ノ内宏昭

147, 148
151

YAMAOKA Kazutaka

山岡和貴

88, 167

YAMASAKI Norichika

山崎訓史

289

YAMASHITA Naoyuki

山下直之

193

ix

YAMASHITA Takayuki

山下孝行

289

YAMAUCHI Hiromoto

山内啓資

3

YAMAZAKI Toshimitsu
YAMAZAKI Yasunori

34, 84

山崎敏光

95, 96, 102, 103, 104,

山崎泰規

105, 173YANAGA Makoto

119

矢永誠人

YANAGISAWA Yoshiyuki

44, 46, 47, 48, 49,

柳澤善行

50, 54, 55, 56, 57,
58, 59, 60, 61, 62,
63, 64, 66, 68, 69,
75, 76, 77, 78
YANO Yasushige

3, 5, 7, 136, 137, 138, 139,矢野安重

141, 179, 265, 267, 269,
273, 283, 284, 285, 287,
289
YASUDA Ken-ichiro
YASUI Hiroyuki

安井裕之

117

YASUTANI Jun

安谷 純

193

YATAGAI Fumio

谷田貝文夫

YATSUKAWA Makoto
YAZAKI Koichi

143, 144, 145

八津川

YOKKAICHI Satoshi

134

299

矢澤 孝

YEREMIN Alexander V.

誠33, 35矢崎紘一

YAZAWA Takashi

130

安田健一郎

80
85, 86, 87, 257

四日市 悟

YOKOKAWA Harumi

横川晴美

116

YOKOUCHI Shigeru

横内

3, 5, 275, 283, 285

YOKOYA Hiroshi

横谷

YOKOYAMA Akihiko
YOKOYAMA Ichiro
YONEDA Akira

茂

199

洋

3, 5, 277, 279

横山一郎

3, 5, 80, 96

米田 晃

YONEDA Ken-ichiro

130, 134, 263

横山明彦

米田健一郎

50, 53, 56, 59, 60, 62,
66, 69, 76

YONEYAMA Tetsu

米山

哲

84

YOSHIDA Atsushi

田敦54, 57, 58, 61, 66, 69, 70,
80, 173, 189, 293, 295,
297, 299, 301, 303, 305

YOSHIDA Koichi

47, 54, 55, 61, 63, 70, 74,

吉田光一

189, 291, 293, 295, 297,
299, 301, 303, 305
YOSHIDA Shigeo

吉田茂男

147, 148, 149, 150, 151, 152

YOSHIMI Akihiro

吉見彰洋

71, 79, 112, 160, 161, 170,

YOUN Minyoung

尹

65

YUKI Hideyuki

結城英行

171, 175YUN Chong Cheoul

民榮

263

尹 鍾哲

YUN Pil-Yong150

ZANTOW Felix

212

ZHAO Yu-Liang趙宇亮

ZHENG Tao

涛70, 80x

鄭80

64, 65ZHUKOV Mikhail V.

42, 43