RIKEN
Accelerator
Progress Report
vol.

35

理化学研究所

RIKEN (The Institute of Physical and Chemical Research)

RIKEN Accelerator Progress Report
January-December

I' t

f ~ ijff :9E PITRIKEN (The Institute 01 Physical and Chemical Research)
Wako, 5aitama, 35 J -0 J 98 JAPANChairperson of the Editorial Committee

K. Asahi
Editorial Committee

T.Abe

T. Ichihara

K. Ishida

T. Kambara

O. Kamigaito

Y. Kobayashi

A. KohamaA. Ozawa

I. Shimamura

K. Yazaki

All rights reserved. This report or any part thereof may not be reproduced in any form
(including photostatic or microfilm form) without written permission from the publisher.
All reports are written on authors' responsibility and thus the editors are not liable for thecontents of the report.

CONTENTS
Page
I.

PREFACEII.

OPERATION OF ACCELERATORS

1

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

3

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

5

Operation of the tandem accelerator

7

III.

RESEARCH ACTIVITIES

1.

Nuclear Physics
Triaxially deformed states in the Monte-Carlo Shell Model

9

Extreme location of the fluorine drip line .............................................

10

Magic numbers of exotic nuclei .......................................................

11

A Search for a unified effective interaction for Monte-Carlo Shell-Modelcalculations (III) ......................................................................

12

Relativistic mean field theory with pion for finite nuclei .... ...........................

13

Parity-violating mean field theory with the pion ......................................

14

Cranked relativistic mean-field study of chiral doublet bands ........ .... ........ . .....

15

Three-dimensional TDHF calculation on reactions of unstable nuclei ..................

16

Resonance and continuum states in weakly bound systems ............................

17

Triaxial deformation in lOBe ..........................................................

18

Equilateral-triangular shape in 14C ...................................................

19

Description of the Gamow-Teller resonance within the phonon damping model ........

20

Phonon damping model using random-phase-approximation operators .................

21

Improved treatment of ground-state correlations: Modified random-phaseapproximation ......................................... .... ............ . ..............

22

Determination of the matter surface distribution of unstable nuclei. . . . . . . . . . . . . . . . . . . .

23

Observation of new neutron and proton magic numbers ...............................

24

Possibility of an enlarged core structure of N = 15 neutron-rich nuclei .................

25

Fission-barrier heights estimated by a nuclear mass formula. . . . . . . . . . . . . . . . . . . . . . . . . . .

26

Estimation of alpha-decay half-lives with phenomenological formulas ..................

27

A software supporting experimental plan for new elements synthesis ...................

28

A two-step model for fusion and synthesis of superheavy elements .....................

29

44Ti: Its initial abundance in Cassiopeia A and its detection possibility in SN 1987A
with INTEGRAL .....................................................................

30

Formation of nuclear "pasta" in cold neutron star matter .. ...........................

31

Recent developments in an experiment to measure nuclear half-lives relevant to theastrophysical r-process ............................................................. . ..

32

r-process in prompt supernova explosions .............................................

33

r-process nucleosynthesis in the type-II supernova model with a neutron star massof rv 1.4MQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

34

Neutrinos from supernova explosions and protoneutron stars ..........................

35

Shell-Model calculations for ~7 0 and ~60 with microscopic AN and L:N effective
interactions ...........................................................................

36

Nuclear K bound states in proton-rich systems to be formed by (K -, 7[ - )reactions through A* as a doorway. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

37

Coulomb logarithm in the electron-cooling process ....................................

38

Measurement of the effect of a non-equilibrium liquid D2+ T2 mixture inmuon-catalyzed dt fusion .............................................................

39

Electron-RI collider at MUSES: A possible electron spectrometer. . . . . . . . . . . . . . . . . . . . . .

40

High-spin isomeric beam line. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

41

N aI(TI) response for radioactive isotope beams ........................................

42

Absolute detection efficiency measurement of large plastic scintillators for neutrons
at 100 MeV........... ... .. . ........... .......................................... .....

43

Polarization transfer measurement for d-p elastic scattering ........... . ...............

44

Measurement of the analyzing powers for the ad ---+ 3Hp and ad ---+ 3Hen reactions
at 270 MeV........................... ... ...... ...................................... .

45

Measurement of the tensor analyzing power (T20 ) in the dd ---+ 3Hp and dd ---+ 3Hen
reactions at 0° ........................................................................

46

Measurement of single and double spin-flip probabilities in inelastic deuteronscattering on 12C at 270 MeV .........................................................

48

Measurement of Doppler-shift attenuated "y rays from the 180(2t) state. . . . . . . . . . . . . . .

49

Projectile excitation in 160+208Pb,natc at E(l60) = 100A MeV: Preliminary results ..

50

Indirect measurement of the solar-neutrino production reaction 7Be(p,"Y )8B ...........

51

Determination of the astrophysical S factor of the 8B(p, "Y)9C capture reaction fromthe 8B( d, n)9C reaction ...............................................................

52

Inelastic scattering of 12Be with 4He ..................................................

53

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

54

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

55

Isobaric analog state of 14Be ..........................................................

56

Two-neutron breakup experiments on 11 Li, 14Be and 17B ..............................

57

l1C(p ,"Y ) 12 N reaction studied by the Coulomb dissociation method .... . ...............

58

Low-energy E1 strength in 13 0 .......................................................

59

Study of proton resonance states in 130 and 12N using elastic resonance scattering ....

60

2.

Projectile fragmentation of 14 0 at 60 A Me V on 4He ................................. .

61

Coulomb dissociation of 13N and 14 0 ................................................ .

62

El strength of the subthreshold 3/2+ state in 15 0 and its influence on the CNO
reaction 14N(p,,)150 ................................................................ .

63

Measurements of the reaction cross sections of C isotopes at intermediate energy ..... .

64

Study of the spin polarization of 19C for a g-factor measurement ..................... .

65

Search for 21 B ....................................................................... .

66

Measurement of the Longitudinal Momentum Distribution of 220 .................... .

67

First experimental evidence of core modification in a near drip-line nucleus, 23 0 ...... .

68

Study of the 22Mg(p " )23 Al reaction by the Coulomb-dissociation method ............ .

69

Coulomb excitation of 24Si ............................... . ........................... .

70

Study of the first excited state in a very neutron-rich nucleus, 30Ne .................. .

71

Proton inelastic scattering by 32Mg .................................................. .

72

Large collectivity of 34Mg ............................................................ .

73.
.................. . ............ .
Spec t roscopy 0 f 34S'I WI'th'Ine1as t'IC d eu t eron scatt enng74

Production cross sections of neutron rich N = 50 nuclei in 66 A MeV 86Kr-induced
reactions ............................................................................ .

75

Coulomb excitation of 84Se .......................................................... .

76. .Isomer In. 149D y .............................................. .
· h -spIn
g- F actor 0 f a h Ig

77

Study of PHENIX Electron Trigger .................................................. .

78

Measurement of the 8Li(a,n)llB reaction cross section with 8Li beams below
1.5 MeV /n energy .................................................................... .

80

Indication of a reduced chiral order parameter from the Is 7r- states in 205Pb and lightnuclei ................................................................................ .

82

Atomic and Solid-State Physics
Bound states of a positron with molecules

83

Diabatic ionization model for capture of antiprotons by atoms ........................

84

Tunneling effect in the single ionization of N e by an intense laser field .................

85

Theoretical intensity distributions of K X-ray satellite spectra emitted from Al ........

86

Studies on electron degradation and thermalization in H2 and D2 gases ...............

87

Elastic-wave source characterization for 95 MeV /u Ar-ion irradiation on solids .........

88

Anomalous shift of the Curie temperature in Fe-Ni Invar alloys irradiated withhigh-energy ions ......................................................................

89

Final lattice sites and atomic motion of 57Fe atoms in Si immediately after GeV-ion
implantation ..........................................................................

90

On-line TDPAC studies using the 19 0 beam ..........................................

91

3.

Stopping power measurement of 84Kr in a laser-produced plasma... . .. . .. . .. . ... .. . .. .

92

TO F spectral profile of fullerene-like fragment ions in C6 + - C60 collisions ..............

93

Lattice location of hydrogen in Nb-Mo alloys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

94

High-resolution soft X-ray measurements in 2.3 ke V lu N7 + ions transmitted throughan Au micro capillary target ........................................................ . ..

95

Visible light emission from slow highly charged ions transmitted through a Ni
micro capillary ........................................................................

96

Improvement of experimental setup for Ion-atom crossed-beam measurements atenergy range below 100 eV I q ..........................................................

97

Current status of a cooling system for MCI using positron plasma. . . . . . . . . . . . . . . . . . . . .

98

Precision spectroscopy of the Zeeman splittings of the 9Be+ 2 2S 1/2 hyperfine
structure levels .......................................................................

99

A cryogenic ion trap for improving the trapping lifetime of Be+ ions ..................

100

Optical detection of atoms and ions in superfluid helium ..............................

101

Study of BaF 2 crystal by a positron annihilation technique. . . . . . . . . . . . . . . . . . . . . . . . . . . .

102

Temperature dependence of the Compton profile for BaF2 crystal .....................

103

Il,SR study of the Cu-spin dynamics in La2-xSrxCU1-yZny04 ..........................

104

Isomer effect on charge transfer from C3H4 molecules (allene and propyne) at ke V
energies ..............................................................................

105

Microwave resonances in the hyperfine structure of antiprotonic helium and deductionof the antiprotonic orbital magnetic moment ..........................................

106

Radiochemistry and Nuclear Chemistry

In-beam Mossbauer study on valence states of 57Fe decaying from 57 Mn implanted
into KMn04 (II) ......................................................................

107

Stimulation of transferrin-dependent 59Fe and 48V uptake in rat isolated adipocytes
by insulin or vanadyl treatment .......................................................

108

Abnormal metabolism of trace elements in mouse caused by Zn-deficiency during
the growth period ....................................................................

109

Brain regional uptake of trace elements in normal mice during development ...........

110

Brain regional tracer uptake and elemental concentration in mice fed Zn-deficientand -excessive diets ...................................................................

111

Subcellular distribution of trace elements in mouse brain regions using themultitracer technique ................................. , .......................... :. .. .

112

Lateral and sexual differences in concentrations of trace elements in cerebral G:ortex ofnormal mice ..........................................................................

113

Trace-element transfer from pregnant mice to the fetuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

114

Influence of sodium iron ethylenediaminetetraacetic acid and ferrous sulfate on thetransport of trace elements in everted intestinal segments of rats ......................

115

4.

5.

Metabolic studies on multitracer-injected rats and plants using a prototype multitracer
gamma-ray emission imaging system (MT-GREI): A proposal. ... . .. .. . .. .... .. . .. . .. .

116

Alleviation of Cadmium cytotoxicity by manganese (II) ...............................

117

Measurement of the binding affinity of multitracer to an apoplast protein extracted fromsoybean root. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

118

Influence of samarium on the uptake of trace elements by marigold. . . . . . . . . . . . . . . . . . . .

119

The effect of EDTA complexation on diffusion of various ions in granitic rock .........

121

Molecular design of organic ligands highly selective for lanthanide metal ions ..........

122

New multitracer production: Development of a gas-jet coupled multitarget system andan automated rapid chemistry apparatus... .. . . . .. . ..... . .. . .. ... . ..... ... ...... ... ...

123

Radiation Chemistry and Radiation Biology

Ultrafast plasma luminescence of heavy-ion tracks in insulators

125

Enhancement of 137 Cs accumulation by phytochelatine synthetase expression inrhizofungus Fusarium oxysporum .....................................................

127

Effective plant-mutation method using heavy-ion beams (VI) ..........................

128

Isolation of sterile mutants of Verbena hybrida using heavy-ion beam irradiation ......

129

Isolation of variegated mutants of Petunia hybrida using heavy-ion beam irradiation

130

Induction of mutation in Sandersonia aurantiaca Hook. by heavy-ion beamirradiation ...... . .....................................................................

131

Mutation induction in human cells after low-dose exposure to heavy ions ..............

132

Delayed cell-cycle progression following exposure to heavy ions

133

Instrumentation

Developement of the in-flight separator CRIB

135

Test of low-energy RI beam production with CRIB... . . .. . . ... .. . . . . . . . ... .. . .. . .. . .. .

137

The first observation of slow muon beam at the RIKEN-RAL Muon Facility. ..... ... ..

138

Design of a spin polarized positron beam and a spin rotator. . . . . . . . . . . . . . . . . . . . . . . . . . .

140

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

141

Development of RI atomic beam device with a Laval-type nozzle ......................

143

Development of a detector system for transient magnetic field experiments ............

145

Gas cell RI beam stopper with electric transportation system .........................

146

RF deflector system for proton-rich RI beams (II) .....................................

147

Liquid hydrogen target for SMART experiments ......................................

148

Development of polarized proton target for RI beam experiment ......................

149

Continuous spin precession of noble gas nuclei with active feedback system ............

151

Rotating target system for the Big-RIPS separator ....................................

152

6.

7.

Performance of a new gas-filled recoil separator GARIS at RILAC facility measured
using 208Pb and 209Bi recoils ..........................................................

154

Installation of a high-resolution magnetic spectrograph PA ............................

156

Development of a multiple-reflection TOF mass spectrometer .........................

157

Improving neutron detection efficiency by using passive converters ....................

159

High-efficiency positron moderator using electropolished tungsten meshes .............

160

Development of a time-of-flight detector with streak camera II ........................

161

Study of scintillator radiation hardness ...............................................

162

Development of fast timing beam line scintillator for RIPS with PMTs operated in
vacuum...............................................................................

164

Development of plastic scintillators as possible energy detectors for proton scattering
at RIBF ..............................................................................

165

Development of segmented Ge array ..................................................

167

A hybrid array for charged-particle and ry detection ...................................

169

Development of reaction-suppressed total-energy detector .............................

171

Development of a beam loss monitor ..................................................

173

Absolute calibration of deuteron beam polarization at intermediate energies via
12C(J: a)lOB*[2+] reaction ............................................................

174

Advanced network for RIKEN Accelerator Research Facility ..........................

176

RIPS control system with EPICS .....................................................

177

Trial of RTLinux for embedded control and measuring system .........................

178

Simulation of imaging using Compton camera

179

Material Analysis

Mechanical properties of polyimide films implanted with metals

181

Development of a highly sensitive high-resolution in-air particle-induced X-ray
emission (PIXE) system: II ...........................................................

182

RIKEN-BNL Collaboration on Spin Physics Program
Polarized gluon distribution for light hadron pair productions in semi-inclusive
pol-DIS ...............................................................................

185

Polarized s-Quark distribution in charmed hadron production. . . . . . . . . . . . . . . . . . . . . . . . .

186

Charmed hadron production and polarized gluon distribution .........................

187

Uncertainty of polarized gluon distribution at RHIC ..................................

188

Single-spin asymmetries and soft-gluon poles ..........................................

189

Partons and QCD in high-energy pp collisions .........................................

190

Gluon saturation from small-x evolution equation .....................................

191

Structural change of Cooper pairs in color superconductivity ..........................

192

Light Goldstone boson and domain walls in the KO -condensed phase of high density
quark matter .........................................................................

193

Non-perturbative renormalization of pion exchange ...................................

194

The flow of colored glass in heavy ion collisions .......................................

195

Soft gluon dynamics at non-zero baryon density. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

196

Neutrino cross sections and future observations of ultrahigh-energy cosmic rays

197

Scaling relations for the transverse mass spectra and the color glass condensate

198

Hadronic signals of QGP ..............................................................

199

Kaon condensation in QCD ...........................................................

200

Novel phenomena in high-density QCD ...............................................

201

Hydrodynamic analysis of elliptic flow at RHIC .......................................

202

Initial coherent gluon production from the color glass condensate in relativistic
nuclear collisions ......................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

203

Probing the QGP equation of state with two-particle interferometry. . . . . . . . . . . . . . . . . . .

204

Hadron spectrum for quenched domain-wall fermions with an improved gauge action. .

205

Calculation of K ---+ KK decay in quenched domain-wall QCD ............... . .. . .......

206

CP violation in K decay from lattice QCD ..... . ............... ........ ...............

207

Chirality and localisation of domain wall fermion eigenvectors. . . . . . . . . . . . . . . . . . . . . . . . .

208

QCDOC project ......................................................................

209

QCD phase structure with many flavors.. . .. . .. .. . ... .. . .. . .. . ... ... .. . .. ...... ... . ...

210

Nucleon axial charge on the lattice ....................................................

211

Gauge actions and chiral symmetry of domain wall fermions ................ ..........

212

Scalar glueball mass reduction at finite temperature in SU(3) anisotropic lattice
QCD .................................................................................

213

Calorons and localization of Dirac eigenvectors in lattice QCD ...... .. ....... .........

215

Overview of RIKEN/RBRC activities for RHIC spin physics 2001 ....... .... ... .......

216

Measurement of neutral pion transverse momentum distributions at
VSNN = 130 GeV Au+Au collisions. .. . . .... . .. . .. ... ... . .. . ..... ... . ... .... . . . . . . . . . .

218

Measurement of the transverse energy distributions in Au+Au collisions at
VSNN = 130 GeV .....................................................................

219

Spin monitoring for first polarized proton collisions ...................................

220

Final result of analyzing power measurement of proton-carbon elastic scattering in
CNI region at 22 Ge V / c ...............................................................

221

Asymmetry measurement of charged hadrons at PHENIX .............................

222

Parity violation at RHIC in jet production ............................................

223

Operation of the PHENIX muon identifier .................. ........ ..................

224

8.

Performance of the PHENIX muon identifier ..........................................

225

RHIC pC CNI polarimeter readout ...................................................

226

Results from RHIC polarimeter commissioning run 2000 ..............................

228

PHENIX muon tracker: Construction, year-2 operation and preliminary data
analysis ...............................................................................

229

Geometry alignment of PHENIX Muon tracker .......................................

231

First commissioning of the PHENIX south muon tracker: The gas system and theoptical alignment system ........................................................ . . . . . .

232

Analytical field calculation of helical magnets with an axially symmetric iron yoke ....

234

Computing center in Japan for RHIC physics (CC-J) .................................

236

Operation of Objectivity IDB system at CCJ ......................... . ................

238

Data Carousel/ORNL batch system for HPSS at CCJ .................................

240

Measurement of electron and photon at RHIC-PHENIX ...............................

241

Performance of PHENIX RICH for RHIC first year run ...............................

242

Performance of the PHENIX EM Calorimeter .........................................

243

Hadron measurement at RHIC/PHENIX ..............................................

244

Analysis of experiment KEK PS-E325, for the measurement of wi ¢ meson decays innuclear matter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

245

Miscellaneous

Development of new analytical system using the electron cyclotron resonance ion
source and heavy ion linear accelerator ................................................
IV.

NUCLEAR DATA

New method for calculating aggregate fission-product decay heat with full use of
macroscopic-measurement data .......................................................
V.

247

249

DEVELOPMENT OF ACCELERATOR FACILITIES

Effect of plasma electrode position on the beam intensity of heavy ions from RIKEN
18 GHz ECRIS .............................. . ........................................

251

Effect of plasma chamber surface on production of highly charged ions from ECRIS ...

253

Liquid-He-free SC-ECRIS at RIKEN ..................................................

254

Development of ECR ion sources for high-intensity heavy ion beams ..................

256

Laser plasma for direct plasma injection to RFQ Linac on RIKEN laser ion source ....

258

Carbon beam acceleration using direct injection method ..............................

260

Development of long-lived carbon foil for charge stripper in RILAC ...................

262

Low-energy beam test of liquid film charge stripper ...................................

264

Control system for RRC, AVF and RILAC ............................................

266

Measurement of an open-loop transfer function of a feedback control system of cavity
voltage ...............................................................................

268

VI.

Development of multi-injection system for the AVF cyclotron ... . .....................

270

Construction of the flat-top acceleration system in the RIKEN AVF Cyclotron ........

272

AVF -P A beam transport system .................... . .................................

274

Beam transport line from AVF to CRIB-FO target ....................................

275

Conceptual design of the fixed-frequency ring cyclotron ........... . ...................

277

Magnetic field measurement of the IRC sector magnets ................................

279

Electric field measurement of the acceleration resonator for the Intermediate-stage
Ring Cyclotron (IRC) ........... . ....................................................

281

Design study on beam transport system from IRC to RARF .. . .......................

283

Status of the SRC for the RIKEN RI Beam Factory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

285

Effect of Vr + V z = 2 resonance in the SRC ............................................

287

Superconducting bending magnet for the injection system of the RIKEN SRC .........

289

Superconducting sector magnet for the RIKEN SRC ..................................

291

Design of the extraction bending magnet for the RIKEN SRC ............ . ............

293

Quench protection of RIKEN Superconducting Ring Cyclotron.... .. . .. ... ... . .. . .. ...

295

Design study of beam transport lines from SRC to Big RIPS ..........................

297

Design study of quadrupole magnets for the beam-transport line and BigRIPS
separator .............................................................................

299

Projectile fragment separator BigRIPS for the RI-Beam Factory project ...............

301

Superconducting quadrupole magnet with small refrigerators. . . . . . . . . . . . . . . . . . . . . . . . . .

303

Design study of 2 Tesla dipole magnet by three-dimensional calculation ...............

305

Studies on MUSES control system using RT-CORBA .......... . ........... . ..........

307

Update of MUSES ACR lattice design ................................................

308

Design of MUSES electron cooler at RIKEN ..........................................

310

Instability during electron-cooling bunching, predicted from a simulation ..............

312

Design of highly-sensitive current monitor with HTS SQUID and HTS magnetic
shield. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

314

Development of the kicker magnet for MUSES (II)316

RADIATION MONITORING

Routine work for radiation safety in the Ring Cyclotron Facility

319

Shielding calculation for the CSM installation at RILAC ..............................

321

Improvement of radiation safety system for RIKEN Ring Cyclotron .... . ..............

323

VII.

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

325

VIII.

LIST OF PREPRINTS

333

IX.

PAPERS PRESENTED AT MEETINGS

336

X.

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

351

XI.

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

353

XII.

LIST OF PERSONNEL

357

AUTHOR INDEXRIKEN Accel. Prog. Rep . 35 (2002)

I. PREFACE

This issue of RIKEN Accelerator Progress Reportreports research activities of the RIKEN Accelerator
Research Facility (RARF) during the calendar year of
2001. The research programs have been coordinatedin the framework of the project entitled Multidisciplinary Researches on Heavy-Ion Science. The project
involves a variety of fields such as: nuclear physics, nuclear astrophysics, atomic physics, nuclear chemistry,
radiation biology, condensed matter physics in terms ofaccelerator or radiation application, plants mutation,material characterization, application to space science,accelerator physics and engineering, laser technology,
and computational technology.
These activities involved ten laboratories, five Centers involving seven divisions, the RIKEN-RAL Center, and the RBRC (RIKEN BNL Research Center),and more than 350 researchers from domestic and foreign institutions. Thirty-six universities and institutes
from within Japan and 33 institutes from 10 countries
are included.
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 Me V azimuthally varying field cyclotron (AVF) , which have altogether provided a beamtime (on the target) of more than 4000 hours throughthe year. This number is slightly shorter than those ofprevious years because of the planned shutdown due
to the construction-program of the RI Beam Factory.
The three accelerators deliver heavy-ion beams of avariety of elements with energies ranging from a few
A MeV to 135 A MeV. The two-injector machines(AVF and RILAC) are equipped with ECR heavyion sources. The AVF is additionally equipped witha polarized ion source for vector and tensor polarized
deuterons. The three accelerators have been used invarious configurations. The RRC operates either with
the AVF or the RILAC as the injector. The AVF has
been providing beams of ions of mass number up to 60.
The energy booster for the RILAC has been installed
so that the maximum beam energy from the RILAC
has been raised to 6 A MeV. High-intensity beams
of intermediate-mass ions will be able to be deliveredin early 2002. That also will enable to deliver highintensity beams of intermediate-mass elements such as
Ni and Kr up to 85 A MeV from RRC. In addition, theAVF and the RILAC are used separately, when they
are not used as the inj ector, for low-energy applications. In particular, the use of high-intensity RILAC
beams is expected to provide great opportunities forsuperheavy element researches. Two thirds of the RRC
research beam time ( ~ 3300 hours in total) is used fornuclear physics and nuclear astrophysics and one thirdis used by atomic physics, material science, nuclear
chemistry, radiation biology and others. While, theAVF beam time were also used for fields other than
nuclear physics. The research beam time at the AVF
is 2100 hours and 800 hours at the RILAC.
The RARF carries many international collaborations . Among them are large-size two internationalcollaboration programs using overseas accelerator facilit ies: one is the muon science project at ISIS in collaboration with the Ratherford-Appleton Laboratory(RAL), and the other is the spin physics program at
RHIC in collaboration with the Brookhaven National
Laboratory (BNL). The pulsed muon-beam facility at
ISIS has been operating steadily. At the RHIC facility, the first heavy-ion beam and the first polarized
proton beams have been successfully accelerated. The
first collision of polarized protons in the collider wasobserved in December 2001. Other smaller collaborations using foreign facilities are going on at Lanzho(China), Dubna (Russia), CERN, GSI (Germany), andTRIUMF (Canada).
The use of RI beams is the main focus of the activities at the RRC. Major subjects pursued are: (1) exotic nuclear structure and new dynamics of extremely
neutron-rich nuclei (such as those with a neutron haloor skin) , (2) nuclear astrophysics involving unstablenucleus reactions, (3) synthesis of new unstable isotopes far from the valley of stability, (4) extensive
measurements of nuclear moments. Characteristic features of intermediate-energy direct reactions are often
exploited for such studies.
We have collaborated with the CNS of the Universityof Tokyo for installing the new low-energy RI beam
separator (CRIB) to use the low-energy beam fromthe AVF. High-quality low-energy RI beams are now
available as a CNS jRIKEN facility.
Highlights of the year include: (1) The discoveryof 5H nucleus. (2) A continuation of discovery of new
magic numbers to Z = 16, N = 32 and 34. These studies show that the magic numbers are radically changing
off the stability line. (3) Observation of isobaric analog
stat es of halo nuclei. (4) Continuous developments in
Coulomb excitation and Coulomb dissociation of neutron rich nuclei . (5) Detailed study of three-body interactions with polarized deuteron beam. (6) The delivery of the first slow muon beam at the RAL facility.
(7) The development of an on-line polarimeter for the
RHIC spin project.

1

In theory, outstanding results have been obtained
and continue to emerge from Monte-Carlo Shell model
calculations. Many properties of nuclei far from thestability lines have been correctly predicted using theAlphleet parallel computer in RARF. The N = 16
magic number in oxygen isotopes has been understoodby an inclusion of the spin-isospin interactions. Also,
the study of molecular states with alpha clusters andloosely bound neutrons under covalent bonds is of special interest in the theory group. New Relativistic
Mean Field model of nuclei are under development including the pion field. This new model is expected toopen new base for nuclear structure.
Intermediate-energy heavy ions from the RRC havefound their own applicability. A strikingly efficient mutagenic effect has been observed when the embryo ofa Tobacco plant is shot by heavy ions. High-energy
heavy ions were irradiated to the plants placed in the2

air for desirable amount of LET. It has opened amethod to produce mutants that is efficient and wellcontrolled. The method is so efficient that it is expected to offer new possibilities of bioscience researchthrough comparison between normal and mutagenic
samples. The first flowers developed by this method
are now available commercially.
The RI Beam Factory project is progressing well.
The building for the cyclotrons and the separators areunder construction. The sector magnets of the IRe
has been completed. The first experiment is expected
to start in 2005.

1. Tanihata
Director, Experimental System GroupRIKEN Accelerator Research Facility

II. OPERATION OF ACCELERATORSRIKEN Accel. Prog. Rep. 35 (2002)

RILAC operation
E. Ikezawa, M. Kase, S. Kohara, O. Kamigaito, 11. Fujimaki, T. Nakagawa, M. Kidera, N. Fukunishi,
M. Nagase, M. Kobayashi-Komiyama, 1. Yokoyama, T. Aihara,* T. Ohki ,* H. Hasebe,* H. Yamauchi,*A. Uchiyama,* A. Goto, and Y. Yano
RILAC has been upgraded using accelerators of thecharge-state multiplier (CSM). Six cavities of the CSM
were installed just after the installation of the final cavity of RILAC as a booster in the summer of 2000, as
shown in Figs. 1 and 2.1) The maximum beam energy,
boosted by the CSM, became 5.8 MeV /nucleon. Highpower tests of the new cavities have been under way
since September 2000,2) and a beam test was started
in May 2001. 3 ) The 40 Ar ll + beam was successfully accelerated up to 5.8 MeV /nucleon with an intensity of
4.8 pJ-lA. The beam energy was determined by the analyzer magnet BM90 in which a NMR probe measured
the magnetic flux density precisely. The transmission
efficiency through the CSM was 98% for the Ar ll +beam. However, the maximum transmission efficiency
from the ion source to the end of the CSM was 62%
in this case, because the typical transmission efficiency
from the ion source to the end of RILAC is 50 to 70%.
To utilize the beams accelerated by RILAC or the
RILAC + CSM for various experiments, the beamtransport system was replaced with a new one, as
shown in Fig. 2.4) It has one main transport line to the
RIKEN Ring Cyclotron (RRC) and six branches (beamlines e1-e6). The e2, e3, e5 and e6 beam lines areused for radiation chemistry, for the search for superheavy elements with a gas-filled recoil isotope separator (GARIS), for the development of a new charge
stripper system and for the accelerator mass spectrometer, respectively. The e4 beam line is exclusively usedby the CNS of University of Tokyo.
One of the most important experiments proposed
here is the search for super-heavy elements via a subbarrier fusion reaction with the GARIS. The maximum energy was selected for this research. It has been
decided that for the next two years, until the RIBF isready to start, a stand-alone use of RILAC using the
CSM will be mainly used for this experiment.
We tested the beam delivery to RRC and the newexperiment course with the conventional beam energies
of RILAC. We also carried out a preliminary beam test
for the GARIS experiment with the maximum beamenergy. We did not detect a sizable beam loss in eithercase. Since May, RILAC has been in steady operationand has supplied various kinds of ion beams for an
acceleration test and test experiments.
We experienced the following machine problems during this reporting period.
(1) Two quadrupole magnets m the drift tubes(DTl-l and DT2-17) of the No. 1 and No. 2
SRI Accelerator Service, Ltd.

Fig. 1. Photograph of the CSM A1-A4 cavities.

Fig. 2. Photograph of the CSM A5- A6 cavities, the beamlines e1- e5 and t he GARIS in the No.1 target room.

RILAC cavities suffered insulation failure in
their tape coils and the beam was accelerated
without these magnets being excited during theoperation. The magnets and the drift tubes were
replaced with new ones in April 2001.
(2) An rf feeder for the No . 5 RILAC cavity had avacuum leak at the cone-shaped alumina insulator. The insulator was replaced with a newone.
(3) A contact finger in a coaxial line supplying radio
frequency power from the No.5 main amplifierto the feeder melted due to rf currents being too
high.
(4) A serious water leak has been detected in the3

CSM A4 cavity at the top of the outer conductor of the power feeder. The reason is that thebrazing around the water channel was incomplete. Since the brazing was made in the sameway in the CSM A3, A5, and A6 cavities, we
replaced the outer conductor in all of these cavities.
(5) An 18 GHz ECR ion source suffered insulation
failure between the plasma chamber and thesolenoid coil. The surface of the insulator wascleaned and was reused.
(6) All water pumps were inspected. As a result,a water pump of the deionized water circuit for
RILAC was overhauled because of a deteriora-

4tion of the mechanical seals, and a cooling towerpump for the RFQ injector was found to be worn
out, and thus we replaced it with a new one.
References
1) E. Ikezawa et al.: RIKEN Accel. Prog. Rep. 34, 3(2001).
2) O. Kamigaito et al.: Proc. 13th Symp. on Accelerator
Science and Technology, Osaka, 2001-10 (2001), p. 229.
3) E. Ikezawa et al.: Proc. 13th Symp. on Accelerator Science and Technology, Osaka, 2001-10 (2001), p. 169.
4) N. Fukunishi et al.: RIKEN Accel. Prog. Rep. 34, 327(2001).

RIKEN Accel. Prog. Rep. 35 (2002)

RRC and AVF operation
M. Kase, T. Kageyama, M. Nagase, S. Kohara, T. Nakagawa, E. Ikezawa, M. Fujimaki, N. Fukunishi,
S. Numata, O. Kamigaito, M. Kidera, A. Yoneda, M. Kobayashi-Komiyama, 1. Yokoyama, H. Isshiki,*
H. Akagi,* R. Abe,* N. Tsukiori ,* K. Takahashi,* T. Maie,* R. Ohta,* K . Kobayashi,* M. Nishida,*
A. Goto, and Y. Yano
The statistics of operation of the RIKEN Ring Cyclotron (RRC) in 2001 is shown in Table 1. The
RRC together with the AVF and the RILAC haveroutinely provided a beam time of more than 4000
hours throughout the year 2001. This value is smallest among these ten years. The RRC operation wasinterrupted frequently in 2001 due to the installationof AVF beam transport and also improvements of the
AVF. The RILAC-RRC operation has been limited
since 2000, because the RILAC had been shut down
due to the upgrade program.
More than fifty kinds of ion beams were preparedin 2001 . These beams were used in experiments ina variety of fields, such as nuclear physics, atom andsolid-state physics , radiochemistry, nuclear chemistry,and radiation biology.
With the framework of the collaboration between
RIKEN and CNS of Tokyo University, the following
projects have been carried out and almost all of theseprojects were completed this year.
(1) The 14 G Hz ECR ion source was installed in theion source room of AVF .
(2) The two 45-deg dipole magnets between the horizontal beam line from the ion source and thevertical injection line of AVF was replaced bya new horizontally rotationable 90-deg dipole
magnet. As the result, the switching of morethan one ECR ion source in a short time became possible, keeping the vertical injection line
for the polarized ion source as before.
(3) A flat top rf system was added to cavities of the
AVF. Efficient extraction of a high-quality beam
is expected at the AVF.l)(4) A new beam transport line from the AVF to thepresent beam line of the RRC was designed andTable 1. Statistics of RRC operation in 2001.
Operation time of RRC
Beam Service Time6258 hr
4084 hrNuclear Physics Experiment
Non-Nuclear Physics Experiment

92%
8%

RILAC-RRC Operation
AVF-RRC Operation

8%
92%

SRI Accelerator Service, Ltd.

was partially completed in summer 2001. It will
be connected to the beam line to the E2 target
room, where the PA appearing in the next item
is installed.
(5) Two large-scale apparatuses of the nuclear
physics experiment, CRIB and P A, were installed in the target rooms E6 and E2. An experiment involving the CRIB has been carriedout since summer 2001.
(6) The maximum energy of the RILAC was upgraded from 4 to 6 MeV /nucleon . Four linac
cavities were added to the first unit of the CSM
which was completed in 1999.
With the completion of the CSM, a new configuration of the RILAC-CSM-RRC operation became possible. It was found that it is very useful for improving
the beam intensity of some beams. The RRC was designed to operate using a harmonic number of 9 in thecase of the RILAC-RRC. Due to the energy variability of the RILAC, the RRC has been operated using
higher harmonic numbers such as 10, 11, and 12 as wellas the designed one. In the new scheme of the RILACCSM-RRC, the RRC can be operated using harmonic
numbers of 8, 7 or 6. Some beams, which had been
available only in the AVF-RRC , can be obtained witha much more intensity in this scheme, because lowercharge-state ions are acceptable for RILAC and also
because the transmission efficiency of t he RILAC isbetter than that of the AVF. Such beams, some ofwhich are very important for nuclear physics experiments , are listed in Table 2 and shown in Fig. 1. To
realize these accelerations, however, a more powerful
re-buncher is necessary for the injection of the RRC.
A test of the RILAC-CSM-RRC with h = 8 was carried out in October 2001. A beam of 64 MeV/nucleon
84Kr was accelerated with a beam intensity of 60 pnA
which is fifty times that obtained in the AVF-RRC sofar. Half of the beam was lost in the RRC , because therf power of rebuncher before the RRC was insufficient.
A superconducting ECR ion source has been developed and its beam test is now in progress.2 ) As
the method of inserting a solid element into the ECR
plasma, a micro-oven system was installed in the
18 GHz ECR at RILAC. The beam intensity of somesolid ions is expected to increase.
Charge stripping of ions after the RILAC will be avery essent ial matter for the RIBF. Recently a longlived carbon foil has been successfully produced,3) andalso, a liquid-type stripper has been developed. 4)5

Table 2. Upgrade of beam intensities with CSM.
(Expected Data)i·',iRILAC -+ CSM -+ RRC
Stripping after CSM

Ion

EMCi,(hMc)

Qj

efti.
(MeV/n) (*)(MeV/n)124 (6)

.

,

Beam

~

Qf

6+ -+ 14+.

6.5

intens.
(pnA) .,

40

1000

RILAC(3 7 .8MHz)+A 1+AZ+A3+A4+AS+A6+RRC
86 (7)

4+ .... 8+4.8

85 · 1 >1000

RILAC(37.8MHz)+A 1 +AZ+A3+A4+RRC

40Ar

86 (7)

9+ -+ 1 7+

5.7

4S

1 :> t~OO

RILAC(37 .8MHz)+A 1+A2+A3+A4+AS+(A6)+Dl +RRC

64 (8)

1 9+ -+ 17+

3.6

36 I

500

RILAC(37 .8MHz)+A 1+AZ+Dl +RRC
64 (8)

116+ .... 30+

3.6

12

I 60

RILAC(37.8MHz)+A 1 +AZ+Dl +RRC

Already r.ested

0.6
Q

200

'2 150

o
v
U

I

:

RILAC+CSM+RRC

J
~

/'

~,

c:::

~ (D)

6, 100

C!J)0]l]!)

:>v

o

>.

o.S .[;o~«m3Q,/:::l.......

h=6

Q)

h=7

C

',AVF + RRC

6

0

"

&,00 ,'(9 CB()- - ()- - -

•

10

o

18m

'3

j'

o

'i

I

I

"

o

0.4

>

~

•
0

: _~ _ -{j _~ _ ~ ____ •HeAl AI' Fe

T)

Q)

/ '

o-c:i) - - - - - - - - - - RILAC+ RRC: c9 ~
0- - - - __
I
0
- --

Kr

"

0

Xe

i

i

'!Ii

0.3

d--_

__ ~ ___<l!l
Er Ta

0.2

Bi

i" I i !

100

200

Atomic Mass Number

Fig.!. Performance of RRC. The two regions surroundedby dashed lines are the conventional acceptances for the
AVF+RRC and RILAC+RRC. The open circles denotes the beams accelerated previously. The three solidlines shows the beams obtained with the new schemeof RILAC+CSM+RRC and the solid circles are beams
shown in Table 1.

6

A previous control system has been replaced bya new one using EPICS. 5 ) The low-level interfaces(CAMAC-CIM-DIM, GPIB) were kept as before. The
new control system covers not only the entire accelerator but also experimental apparatuses such as RIPS
and SMART. A new interface, which had been developed for power supplies in RIBF, is also included III
the new system and tested in a routine operation.

C

h-8
-

yO,

RILAC(37.8MHz)+A 1+AZ+RRC

References
1) S. Kohara et al.: Proc. 13th Symp. on Accelerator Science and Their Applications, Suita, Oct. (2001) , p. 235.
2) T. Nakagawa, T. Kurita, M. Kidera, M. Imanaka, Y.
Higurashi, M. Tsukada, S. M. Lee, M. Kase, and Y.
Yano: Rev. Sci. Instrum. 73, 513 (2002).
3) H. Hasebe et al.: Proc. 13th Symp. on Accelerator Science and Their Applications, Suita, Oct. (2001), p. 369.
4) H. Akiyoshi et al.: Proc. 13th Symp. on Accelerator Science and Their Applications, Suita, Oct. (2001), p. 331.
5) M. Komiyama et al.: Proc. 13th Symp. on Accelerator Science and Their Applications, Suit a, Oct. (2001),
p. 411.

RIKEN Accel. Prog. Rep. 35 (2002)

Operation of the tandem accelerator
K. Ogiwara, T. Urai, and T. Kobayashi
The 1. 7 MeV tandem accelerator was operated for a
total of 141 days for experiments, except for the time
taken for machine inspection and a beam test, during
the annual reporting period from Nov. 1, 2000 to Oct.
31 , 200l.
Experimental studies on the following subjects were
performed, and some are still in progress.
(1) Rutherford backscattering spectroscopy (RBS)(a) Channeling analysis of dopants in semiconducting materials(b) RBS analysis of polystyrene surfaces and glassy
carbon films modified by ion implantation(2) Nuclear reaction analysis (NRA)(a) Lattice location of hydrogen in niobium alloys
by means of the channeling method(3) Particle-induced X-ray emission (PIXE)(a) Trace element analysis of biological and environmental samples using energy-dispersive X-ray spectrometry(b) Development of a highly sensitive high-resolution
in-air PIXE system for chemical state analysis(c) Characterization of the II -VI ternary semicond ucting crystals

7

III. RESEARCH ACTIVITIES1. Nuclear Physics

RIKEN Accel. Prog. Rep. 35 (2002)

Triaxially deformed states in the Monte-Carlo Shell Model
N. Shimizu, T. Otsuka, *1 T. Mizusaki, *2 and M. Honma *3[Nuclear Structure, Shell Model, Collective Motion]
For over half a century, typical collective motions
and the transitional states between them were investigated and related to the dynamical symmetries, which
the Hamiltonian originally has. In order to investigate
these states microscopically in terms of the nuclear
shell model, the Monte-Carlo Shell Model (MCSM)
was developed. 1)
In the Xe-Ba region, where the mass number isaround 130, the nuclei are well known to exhibit thequadrupole collective properties of a triaxial deformation. They are called , -unstable nuclei, because theirpotential-energy surfaces appear to be flat in the direction of" which represents the degree of freedom of
triaxial deformation. Their microscopic investigation
using the nuclear shell model, which was made possibleby the development of the MCSM, is especially important in the transitional region. On the other hand, theexistence of a new dynamical E(5) symmetry was proposed at the transitional nucleus between the spherical and triaxially deformed nuclei. 2) The microscopic
study also enables us to discuss its validity.
In order to discuss the properties of an intrinsic state schematically, we generated a triaxially deformed wave function using BCS theory in the external
quadrupole field, the strengths of which corresponded
to the deformation parameters, ((3,,). By combining
this wave function and the nuclear-shell-model Hamiltonian, which was obtained through a study using
the MCSM, we obtained a potential-energy surface
parametrized by (3 and , . The Hamiltonian comprised a single-particle potential, pairing, quadrupolepairing, and quadrupole-quadrupole interactions. Figure 1 represents the surfaces of Ba isotopes without
angular-momentum projection (upper part) and thosewith proj ection (lower part).
The even-even nuclei, 136,134,13 2Ba, span a transitional region from a nucleus having the feature of aspherical vibrator 36 Ba) to one having a triaxial deformation 32 Ba). The upper-left part of Fig. 1 showsa feature of spherical shape, because its minimal point
is located at (3 = O. O,n the other hand, the upper-rightpart shows the characteristics of a deformed rotor. We
can see that 134 Ba is a transitional nucleus, and thatits surface appears to be flat in the region 0 < (3 < 0.1.

e

*1

*2'

*3

e

<H>

Fig. 1. Potential-energy surfaces of Ba isotopes. The upper figures show the surfaces of the intrinsic states,
and the lower ones correspond to the J = 0+ states.
The solid (dashed) contour line separations are 100 ke V
(500keV).

This characteristic is consistent with the assumptionof E(5) symmetry.
When we turn our eyes to surfaces with angularmomentum projection, the situation changes drastically. The minima occur in the direction of , ~ 30°in the surfaces of 134Ba and 132Ba, although they still
appears to be flat in the direction of ",(, or , -unstable.
This suggests that the restoration of rotational symmetry plays an important role in obtaining the triaxial state. This phenomenon was also studied and discussed by Hayashi et al. in theoretical work concerning
1880s.3) We have investigated the structures of Ba isotopes more microscopically, the results of which arebeing prepared for publication.
References
1) T. Otsuka, M . Honma, T. Mizusaki, N. Shimizu, andY. Utsuno: Prog. Part. Nucl. Phys. 47, 319 (2001), andreferences therein.
2) F. Iachello: Phys. Rev. Lett. 85 , 3580 (2000); R. F.
Casten and N. V. Zamfir: Phys. Rev. Lett. 85, 3584
(2000) .
3) A. Hayashi, K . Hara, and P. Ring: Phys. Rev . Lett. 53 ,
337 (1984).

Department of Physics, University of Tokyo
Institute of Natural Science, Senshu University
Center for Mathematical Sciences, University of Aizu

9

RIKEN Accel. Prog. Rep. 35 (2002)

Extreme location of the fluorine drip line t
Y. Utsuno,*1 T. Otsuka,*2 T. Mizusaki,*3 and M. Honma*4[NUCLEAR STRUCTURE shell model, unstable nuclei]
In neutron-rich nuclei, the magic number can shift
from that of stable nuclei to another. For instance, theN = 20 magic number disappears at around Z = 12,
and a new N = 16 one appears near oxygen. 1) The
location of the drip line sensitively reflects the magic
structure. In this direction, the drip line of fluorine
isotopes with Z = 9 attracts much interest: the drip
line is located at N = 16 for Z = 6, 7, and 8, while
it extends farther to N = 22 or more for Z = 9. 2) In
this study, we investigated how the drip line suddenly
extends in fluorine isotopes based on large-scale shellmodel calculations using the Monte Carlo shell model(MCSM).3) Because the model space and the effective
interaction are the same as those used in a study ofthe yrast properties of 0, Ne, Mg, and Si isotopes,4)
the present study gives a unified picture of this region
in going from stable to unstable nuclei. Note that thiseffective interaction reproduces the 0 drip line.
The two-neutron separation energies of N = 20 isotones were calculated from Z = 9 to 14, as shown in
Fig. 1 (a). For Z = 10 to 14, the agreement between
the experiment and the calculations with full configurations is excellent. By comparing the full calculations with those in which the configuration is truncatedwithin the O-particle O-hole excitation (OpOh) from theN = 20 core, the importance of the excited configurations is clearly seen, as shown in the ground-state
probabilities in Fig. 1 (b). To be more interesting, the
4p4h configurations rather increase for smaller Z. The
N = 20 nucleus, 29F, is not bound against two-neutron
emission unless the 4p4h configurations are taken into
account . This binding mechanism of 29F , i.e., large
4p4h contribution to the ground state, which is small
for N #- 20 nuclei, is in sharp contrast to the previous
picture of the so-called "island of inversion. " 5) The "island of inversion" picture results in the ground state of
29F having the OpOh configurations, and fails to reproduce unbound 26 0 and bound 29F simultaneously.5,6)
In the present picture, 29F gains correlation energy
through mixing among the OpOh , 2p2h , and 4p4h configurations , and becomes a bound nucleus in a naturalway. By the mixing of the 4p4h , the deformation is
not so enhanced , but the pairing correlation plays asignificant role.
Large 4p4h mixing occurs due to the narrowing

*1
*2

*3
*4

10

Condensed from the a rticle in Phys . Rev . C 64, 011 30 1 (R)(2001)
Japan Atomic Energy Research InstituteDepartment of Physics, University of Tokyo
Institute of Natural Sciences, Senshu University
Center for Mathematical Sciences, University of Aizu

15
(a)

,
,,

10

>'
6 5

,

','/,
/

tl)

/

/

>:!
N
~

0

,,

x

.... .... '

....

,

.... ....

.... ....

.... ....

.... ....

OpOh

100

SO

~ 60

(b)

OpOh
2p2h

.0
0

I-<

0..

40
20

-..~p4h-..-.. -..

-.. -..

-..

--'-

Os

--12

14

Z
Fig. l. (a) Two-neutron separation energies of N = 20 isotones from F to Si compared between experiments (thetriangles and the square) and shell-model calculations
with various truncation schemes. The cross in 29F represents the OpOh + 2p2h calculat ion. (b) Probabilitiesof the npnh (n = 0,2,4) configurations in their groundstates.

N = 20 shell gap, which is defined by the differencein the effective single-particle energies 4) between the
sd shell and the pf shell: for smaller Z. The narrowing
shell gap is caused by a sharp lowering of the neutron
Od 3 / 2 orbit as protons occupy the Od 5 / 2 orbit , being
essential in both the disappearance of the N = 20
magic number and the appearance of the N = 16 one.
Direct evidence about the narrowing shell gap, suchas the negative-parity energy levels , has not yet been
observed experimentally. However, it seems that theextreme location of fluorine isotopes indicates this narrowing, because, provided that it is absent, the boundfluorine must stop at N = 18.

References
1) A. Ozawa et al.: Phys. R ev. Lett. 84, 5493 (2000).
2) H. Sakurai et al.: Phys. Lett. B 448, 180 (1999).
3) T. Otsuka et al.: Prog. Part. Nucl. Phys. 47 , 319 (2001).
4) Y. Utsuno et al.: Phys. Rev. C 60 , 054315 (1999).
5) E . K. Warburton et al.: Phys. Rev. C 41 , 1147 (1990).
6) E. Caurier et al.: Phys. Rev. C 58 , 2033 (1998).

RIKEN Accel. Prog. Rep . 35 (2002)

Magic numbers of exotic nuclei t
T. Otsuka, *l R. Fujimoto,*l Y. Utsuno,*2 B. A. Brown, *3 M. Honma,*4 and T. Mizusaki*5[NUCLEAR STRUCTURE shell model, unstable nuclei]
The magic numbers in exotic nuclei can be different
from those of stable nuclei due to a spin-isospin dependent part of the nucleon-nucleon interaction. In particular, the spin-flip isospin-flip process due to this interaction produces significant monopole shifts of energies
of single-particle states of exotic nuclei, and hence canchange their shell structure drastically.
In order to understand under lying single-particle
properties of a nucleus, we can make use of effective(spherical) single-particle energies (ESPE's), which
represent mean effects from the other nucleons on a
nucleon in a specified single-particle orbit.
Figure 1 shows neutron ESPE's for 30Si and 24 0,
both of which have N = 16. The Hamiltonian and thesingle-particle model space are the same as those used
in Ref. 1, where the structure of exotic nuclei with
N ....... 20 has been successfully described within a single framework. The valence orbits are then Od 5 / 2,3/2,
18 1/2, Oh /2 and 1P3/2 .
The nucleus 30Si has six valence protons in the 8dshell and is a stable nucleus, while 24 0 has no valence
proton and is a neutron-rich exotic nucleus. For 30Si,
the neutron Od 3 / 2 and 181/2 are rather close to eachother (see Fig. 1 (a)). For 24 0, as shown in Fig. 1 (b),the Od3 / 2 is lying much higher and is quite close to
the pf shell, giving rise to a large gap (---6 MeV) between Od3 / 2 and 181 / 2' This large gap was pointed out
in Ref. 2. On the other hand , for the stable nucleus
30Si, a considerable gap (--- 4 MeV) is created between
the Od 3 / 2 and the p f shell (See Fig. 1 (a)). Thus, theN = 20 magic structure is evident for 30Si, whereas
the N = 16 magic number arises in 24 0. In 24 0 ,the Od3 / 2 is lying higher reflecting the large spin-orbit
splitting which is basically the same as that for 170.
Although this high-lying Od3 / 2 orbit is not so relevantto the ground state of lighter 0 isotopes, it should
affect binding energies of nuclei around 24 0. Such an
anomaly was pointed out by Ozawa et al. 3) in observed
binding energy systematics.
The dramatic change of ESPE's from 24 0 to 30Si
is primarily due to the strongly attractive interaction
between a proton in Od 5 / 2 and a neutron in Od 3 / 2. A
schematic picture on this point is shown in Fig. 1 (c)for the general cases comprised of a pair of orbits

*1

*2

*3
*4
*5

Condensed from the article in Phys. R ev. Lett. 87, 082502(2001)
Department of Physics , University of TokyoJapan Atomic Energy Research Institute
NSCL, Michigan State University, USA
Center for Mathematical Sciences, University of Aizu
Institute of Natural Sciences, Senshu University>

8 - (a)

(1)

:::2E

Cl..

en
w

- ~(b)_ _ }Pfshell-~ @§) ","14

~4

--

116

oroo(c)Od3/ 2- O d3/2~- - 18 1/2- -- - 18 1/2

j<= 1-1/2

i,=I?
proton",~-'==:}Pfshell~

neutron(dl

8 0 16

nK

-

-

't<1

p

n

Fig. 1. ESPE's for (a) 30Si and (b) 240, relative to Od 5 / 2 .
(c) The major interaction producing the basic change
between (a) and (b). (d) The process relevant to theintearction in (c).

j > = l + 1/2 and j < = l - 1/2 with l being the orbital angular momentum. Note that j> and j< arenothing but spin-orbit coupling partners. The present
case corresponds to l = 2. As one moves from 24 0 to
30Si, six valence protons are put into the Od5 / 2 orbit.
Consequently, due to the strong attraction shown in
Fig. 1 (c) , a neutron in Od3 / 2 is more bound in 30Si,
and its neutron Od 3 / 2 ESPE becomes so low as compared to that in 24 0 where such attraction is absent.
The process illustrated in Fig. 1 (d) produces the attractive interaction in Fig. 1 (c). The nucleon-nucleon
interaction in this process is written as(1)
The interaction VTO" produces large matrix elements forthe spin-flip isospin-flip processes: proton in j > ~ neutron in j < and vice versa. This gives rise to the interaction in Fig. 1 (c) with a strongly attractive monopole
term for the appropriate sign of VTO"'
In neutron-rich exotic nuclei , due to this mechanism,magic numbers such as N = 8, 20, 38/40, etc. can disappear, while N = 6, 16, 34, etc. may arise, producing
a variety of intersting structures and effects. Mean
filed theories should be developed so as to incorporate
fully the above-mentioned monopole shifts.
References
1) Y. Utsuno et al.: Phys. Rev. C 60, 054315 (1999).
2) B. A. Brown: Revista Mexicana de Fisica 39 , Suppl. 2,
21 (1983).
3) A. Ozawa et al.: Phys. Rev. Lett. 84, 5493 (2000).

11RIKEN Accel. Prog. Rep. 35 (2002)

A Search for a unified effective interaction for Monte-Carlo
Shell-Model calculations (III)M. Honma, *1 T. Otsuka,*2 B. A. Brown,*3 and T. Mizusaki*4[Shell model, Effective interaction]
An effective interaction is a key ingredient of thenuclear shell model. For light nuclei , there are several"standard" effective interactions , such as the CohenKurath 1) and the USD 2) interactions for the p and sd
shells, respectively. In the next major shell, i. e., in
the pf-shell , such an effective interaction has not been
available , mainly because the conventional shell-model
calculation has been difficult due to the huge dimension of the Hamiltonian matrix. However, the Monte
Carlo Shell Model (MCSM) 3) has removed this difficulty. Thus, it is a quite challenging problem to construct a unified effective interaction which is successful
throughout the pf-shell , including both the beginningand the middle of the shell.
We have approached this problem by a "modelindependent" method , in which 195 two-body matrix
elements and 4 single-particle energies are treated asparameters, and are determined by a least-squares fit
to the experimental energy data. We carried out several series of iterative fitting calculations,4) and havepresented the GF40A interaction. 5) In this report we
introduce a much improved interaction, which is called
GXPF1 , as described below.
The fitting procedure was the same as that of the
GF40A interaction , except that the data selection wasslightly changed and the number of varied linear combinations of parameters was increased from 40 to 70.
Starting from the realistic G-matrix interaction withcore-polarization corrections based on the Bonn-C potential,6) the GXPF1 interaction was obtained with a
rms error of 168 keY within FDA * (few-dimensional
basis approximation with empirical corrections).
The GXPFl interaction was examined from various
viewpoints and was found to be quite successful overa wide mass range. As an example , in Fig. 1, various
properties of the first 2+ states are shown for even-even
N or Z = 28 nuclei. In the present calculations, constant effective charges of ep = 1.23 and en = 0.54 areused for all nuclei. It can be seen that the overall systematics is reproduced reasonably well. Recently, newexperimental data have been published for the B(E2)of 58- 64 Ni by Kenn et al.,9) which are also shown in
Fig. 1 (B) by open squares. The present results for
58Ni, 6oNi , and 64Ni are much closer to these new data.
It is worth noting that the present results successfully
*1
*2
*3
*4

12

Center for Mathematical Sciences, University of Aizu
Department of Physics , University of Tokyo
Michigan State University, USA
Department of Law , Sen shu University

4

>
Q)

~

~
x
w

3

2

0
.r- 200
E
",-

~

150

+;+t 100
C\l

N

w
CD

50
0
40

'"E
:§.
+
C\l

20
0

a -20
-40

Fig. 1. Various systematics of the first 2+ states of N or
Z = 28 semi-magic nuclei: (A) excitation energies,(B) B(E2) values to the ground state, and (C) electric quadrupole moments. The filled circles and open
squares show the experimental data. 7 - 9 ) Theoreticalvalues obtained by the FDA * are shown by the solidlines.

reprod uce the experimental systematics over the N or
Z = 28 shell gap including the doubly-magic nucleus
56Ni.
Applications to unexplored regimes of large neutron
numbers or high excitation energy are of great interest.
References
1) S. Cohen and D. Kurath: Nucl. Phys. 73, 1 (1965).
2) B. A. Brown and B. H. Wildenthal: Ann. Rev. Nucl.
Part. Sci. 38, 29 (1988).
3) T. Otsuka et al.: Phys. Rev. Lett. 81, 1588 (1998).
4) M. Honma et al.: RIKEN Accel. Prog. Rep. 33, 16(2000); RIKEN Accel. Prog. Rep. 34, 15 (2001).
5) M. Honma et al.: to be published in Nucl. Phys. A.
6) M. Hjorth-Jensen et al.: Phys. Rep. 261, 125 (1995).
7) R. B. Firestone et al.: Table of Isotopes (Wiley, New
York, 1996).
8) G. Kraus et al.: Phys. Rev. Lett. 73, 1773 (1994).
9) O. Kenn et al.: Phys. Rev. C 63, 021302 (R) (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Relativistic mean field theory with pion for finite nuclei
S. Sugimoto,* H. Toki,* and K. Ikeda[NUCLEAR STRUCTURE, relativistic mean field model, pion]
We have developed a mean-field model that incorporates the pion. It is based on the relativistic mean field(RMF) theory. We applied the new model to various
N =Z nuclei and found that the pion has a large effecton the nuclear mean field.
Recently, mean-field models, relativistic or nonrelativistic, are widely used to study nuclear structure.
They can reproduce the saturation property of nuclei
and the properly large spin-orbit splittings, and therefore give results that agree with the experimental data,
especially bulk data. In these models the tensor force
from the pion exchange is usually missing. However,
we know that the tensor force plays an important rolein nuclear structure based on many studies. Therefore, it is interesting to study nuclear structure in a
relativistic mean-field framework with the pion.
In the relativistic mean field theory, we make themean field approximation (the Hartree approximation). In this approximation, because the pion is a
pseudoscalar meson, the expectation value of the pion
field should be zero if we assume parity symmetry of
single-particle states in a mean field. This is the reason why we did not include the pion in the RMF theory. However, if we imagine that single-particle statesin the mean field are not good parity states, namely,
mixed-parity states, the situation drastically changes.
In this case, the pion can be exchanged by those states
because there exist parity partners in themselves . As aresult, the expectation value of the pion field becomes
finite. The total wave function made by the mixedparity states is not a good parity state, and therefore
we need to project out the good parity state from it. In
this way, we can obtain a wave function that includes
the correlation caused by the pion.
The Lagrangian which we use is

L = ,jj (i'y~a~-M -gau - gw'Y~w~a- ~'''l'"Y
T OJ-L 1r a) ~
m7r
J-L

1
1 2 2
1 W WJ-Ll/+ -0
2 J-L (J"oJ-L (J" - -m
2 cr a - 4 J-Ll/
1 2
1.!:"\ a.!:"\J-L a
1 2 a a+ -m
w wJ-L + -u 1r U 1r - -m 1r 1r .
2
J-L
2J-L
27r
W

In the above equation , only linear terms are written,
but in the actual calculation the non-linear terms of
the sigma and omega mesons are included. For the
coupling constants and masses for mesons, except for

10

J-J

0

L-S .....• .....

40c a

.....

............• ... . .

.....

1~....•.. ..... ·····........•...

· ·· · · · . ~~zr
100

10

A
Fig. 1. Pion energy per nucleon as a function of the mass
number in a log-log plot. 3 ) There are two groups: one isfor the jj-closed shell nuclei , denoted by the open circles,
the other is for the LS-closed shell nuclei , denoted by
the solid circles. The pion energy per nucleon for the jjclosed shell nuclei decreases monotonically and follows
a steeper curve than A - 1/3, which is shown by the solidline.

the pion , we use the TMI parameter set.!) For thepion-nucleon coupling we adopt the pseudovector typeand set the value to i7r ;: : : ; 1, which is taken from theBonn A potential. 2) Because the TMI parameter set
is determined in the absence of the pion , the effect ofthe pion is included in the other mesons. Therefore,
we should refit the parameters in the presence of thepion. This is our next task.
In Fig. 1 we show the potential energy of the pion
normalized by mass numbers.3) From this figure we cansee that the pion energies do not behave volume-likeand make a large contribution to the binding energies(about 5 MeV per nucleon for 56Ni).
We have just started a study of the pion in a relativistic mean-field model. Thus, our result is notvery quantitative. We need to significantly modify ourmodel. However, we believe that through this study
we can obtain a new understanding of how the pion
behaves in nuclei.
References
1) Y. Sugahara and H. Toki: Nucl. Phys. A 579 , 557(1994).
2) R. Brockmann and R. Machleidt: Phys. Rev. C 42 , 1965(1990).
3) H . Toki, S. Sugimoto, and K. Ikeda: nucl-th/0110017.

Research Center for Nuclear Physics, Osaka University

13

RIKEN Accel. Prog. Rep. 35 (2002)

Parity-violating mean field theory with the pion
K. Ikeda, S. Sugimoto,* and H. Toki*[NUCLEAR STRUCTURE, pion, parity-mixing mean field]
Since the establishment of the shell model, we usually solve nuclear many-body problems in model space,
where the single-particle states have good parities. On
the other hand , the parity of a nucleon changes when it
absorbs or emits a pion. As for the importance of thepion, we remind ourselves of the findings involving fewbody systems. 1) The calculated results demonstrate adominant role of the tensor force in a few-body system.
Almost half of the attraction is caused by the tensor
force. Recent variational calculations of the Argonnegroup up to the A = 8 system also demonstrate thedominant role of the pion. 2) These facts suggest that
we look into the possibility of a finite pion mean fieldin nuclear systems.
In doing this, we have to break the parity andisospin symmetries once the pion mean field becomes
finite . Starting with the relativistic meson-nucleon Lagrangian density, which includes the pion term, we canobtain the equations of motion for the nucleon andmesons. 3 ) For simplicity, we write only the equations
for the nucleon, sigma and pion using only the linear
terms:(i''-/''/3M - M - ga(J - gW'YMWM - g7r 'Y5'YM 8M7rara) 1/J
= 0,

(1)

(-~ + m;) (J = -gu (if;'IjJ) ,(2)(-~ + m;) tr a = g 8 (if;'Y5'Yi ra 1/J) .

(3)

7r

i

Here, the brackets ( ... ) denote the ground state expectation value. The pion field is generally finite when
the source term breaks the parity. When the pion field
is finite in Eq. (3), the nucleon single-particle state
breaks the parity in Eq. (I), which again makes thepion source term finite. The self-consistency solution
for the coupled equations provides a converged solution.
We consider the N =Z closed-shell nuclei. Since weassume spherical symmetry for the intrinsic state, thesingle-particle state can be expressed as(4)
where the summation over K, means parity mixing.
Since we are especially interested in the occurrenceof a finite pion mean field, we take the TM1 parameter set of the ((J, w, p) model, which guarantees thesaturation property, and take the value of the BonnA potential for the pion-nucleon coupling. Our study

Research Center for Nuclear Physics, Osaka University

14.. ....

0
-2
-4
:>
CD

~

~
~

-6

-8
- 10

jj
12
56

C-LS
_ _ _ 16 _

Ni

LS

0

> -12 100 Sn _ . - 40Ca - - -14 164 P b _ •• _ SOZr _ . -16 L----J._--'-_-'-_....l....-_.l....-----JL.---.J.._-.J
O.S 0.S5
0.9
0.95
1.05
1.1
1.15
1.2

JJ

Fig. 1. Pion potential energies for different values of thecoupling constant (ag;), within a range 0.8 ~ a ~ 1.2 .

on the pion potential energies of the self-consistent solutions have provided results for the following N =Z
closed-shell nuclei : 12C, 160, 40Ca, 56Ni, 80Zr, lOOSn,
and 16 4Pb. The results of our study along with detailed discussions are presented in Ref. 4. In Fig. I , weadditionally show the results of the pion potential energies of the self-consistent solutions for different valuesof the coupling constant. The critical value of the coupling constant (g;(cr.)) is defined such that it leads toan infinitesimal pion potential energy. We have shownthat g;( cr.) for 12C is smaller than O.80g; and for othernuclei is between 0.80g; and 0.95g;. The critical values increase gradually with an increase of the mass
number, although there is an appreciable difference inthe critical values between two groups of the jj- andLS closed-shell nuclei.
In future work we must fix the parameters of the
Lagrangian , which include the effects of the pion mean
field and the rho meson tensor term, and also take into
account the Fock term in the coupled channel equations of the nucleon and mesons.
References
1) Y. Akaishi: in Few-Body System in Realistic Interaction
in Cluster Models and Other Topics (World Scientific,
Singapore, 1986), p. 259.
2) R. B. Wirringa, S. C. Pieper, J. Carlson, and V. R.
Pandaharipande: Phys. Rev . C 62 , 014001 (2001).
3) B. D. Serot and J. D. Walecka: Advances in Nuclear
Physics, Vol. 16 (Plenum Press, New York, 1986).
4) H. Toki, S. Sugimoto, and K. Ikeda: nucl-th/Oll0017(to be submitted in Phys. Rev. Lett.) and the references
therein.

RIKEN Accel. Prog. Rep . 35 (2002)

Cranked relativistic mean-field study of chiral doublet bands
H. Madokoro and M. Matsuzaki*[NUCLEAR STRUCTURE, Tilted axis cranking]
Recently, much experimental data have been obtained which show the evidence of a tilted axis rotation. There are two topics concerning this phenomenon: one is shears bands;l ) the other is chiraldoublet bands. 2 ) Theoretically, mean-field models haveturned out to be very powerful tools for studying thesetilted axis rotations . So far, all mean-field calculations
were, however, based on a simple pairing + QQ interaction, or a phenomenological core + particle picture.
Fully microscopic and self-consistent calculation withmore sophisticated effective interactions was strongly
desired.
In our previous work,3) we for the first time extended
the relativistic mean field (RMF) model, which has
succeeded to reproduce many properties of finite nuclei, to a description of tilted axis rotation. Our result for the shears bands in 84 Rb was satisfactory. We
are now paying much attention to another interesting
topic , that is, the chiral doublet bands. As discussed
in Ref. 2, this pair of bands appears in triaxially deformed nuclei as the result of a breaking of the socalled 'chiral symmetry' in the intrinsic frame. The
rotational axis would then deviate from any of theprincipal axes . Therefore, we must perform a threedimensionally tilted calculation in the full e - 1; plane ,where and 1; represent the tilt angles. This is contrary to the shears bands in which a description assuming the two-dimensional rotation is adequate.
In this work, we show a preliminary result of the
RMF model applied to the observed tilted bands in
13 4 pr. Although we have just finished an improvement of the code so as to include pairing correlations,
we concentrate here on an investigation without pairing. The configuration is assumed to be that a proton
particle and a neutron hole exist in the 1hll/ 2 high-j
orbital. The valence particle and hole are essential forthe appearance of a tilted rotating state.
Figure 1 shows the calculated and experimental
kinematical moments of inertia. The result is shown
from n = 0.1 MeV up to n = 0.4 MeV . Above thisfrequency, the minimum suddenly moves towards the
I-axis, and we can no longer obtain any tilted rotating states. This is consistent with the experimental
observation where a band crossing occurs at a higher
frequency, as has been seen. Up to n = O.4MeV, wefind relatively good agreement with the experimental
values.
Table 1 shows how the position of the minima inthe e- 1; plane changes as the rotational frequency in-

70 r -_____---,..--- , - - - - - , - -- . . - - - - - ,
60
50

..
............

.::::.~.........•"7;:- 40~..... 30

. . . . .::;~. .... : :;:.:.!:~

20
10cal exp(bandl) ..•....
exp(band2) ......... .

o ~-~--~--~--~-~
0.1

0.2

0.3

0.4

0.5

0.6

Q(MeV)

Fig. 1. Calculated and experimental kinematical moments
of inertia in 134Pr as functions of the rotational frequency.

Table 1. Calculated tilt angles, f) and cp.

n (MeV)

f)

0.1
0.2
0.3
0.4

53°
55°
58°
60°

¢
0°
0°
0°
0°

e

creases. As can be seen from the table, we obtained
two-dimensionally tilted rotating states, but no threedimensional minimum appears (that is, e is deviatedfrom either 0° or 90° , but 1; is always 0°). This is inconsistent with the experimental observation where chiraldoublet bands are observed. The discrepancy can be
attributed to the fact that we neglected the pairingcorrelations. In order for the three-dimensionally tilted
state to appear, the angular momentum of the 'core'
part should be in the direction of the 2-axis , while neglecting the pairing would make the core rigid-like and,
therefore, a rotation around the shortest axis (I-axis)
would be favored . Including the pairing may make thecore irrotational-flow-like and the moment of inertia
around the 2-axis becomes the largest , resulting in thecore angular momentum directed in this axis. Such a
calculation with pairing is now in progress.
References
1) G. Baldsiefen et al.: Nucl. Phys. A 574, 521 (1994).
2) S. Frauendorf and J. Meng: Nucl. Phys. A 617, 131(1997).
3) H. Madokoro, J. Meng, M. Matsuzaki, and S. Yamaji:
Phys. Rev. C 62 , 61301 (R) (2000).

Fukuoka University of Education

15

RIKEN Accel. Prog. Rep . 35 (2002)

Three-dimensional TDHF calculation on reactionsof unstable nuclei t
K.-H. Kim, T. Otsuka, *1 and P. Bonche*2[NUCLEAR REACTION, Unstable nuclei]
Recent developments in experiments with radioactive nuclear beams have opened a new field in nuclear
physics, the study of nuclei far from the ,a-stability line
( i. e. unstable nuclei). Much experimental informationon the structure of such nuclei has been reported andhas exhibited several interesting phenomena, such asa neutron halo and neutron skin, which have not been
seen in stable nuclei. Such characteristic features ofthe structure of unstable nuclei have attracted muchinterest not only in themselves, but also in t heir effects
on reactions. However, studies of the reactions of unstable nuclei with neutron skin have been limited bothexperimentally and theoretically. We consider here thereactions of unstable nuclei with neutron skin.
We have applied here the time-dependent HartreeFock (TDHF) method 1) in three dimensions with thefull Skyrme interaction 2) to study unstable nuclei.
Since we completely remove symmetry constraints imposed on the wavefunction, except for the one withrespect to the reaction plane, the numerical calculations have become much larger and more difficult toperform. We mention that, at present, t he TDHF is
probably the only possible and practical means for describing massive transfer and fusion of nuclei with neutron skin where the density, mean potential and shapeof the nuclei may change much more drastically compared to stable nuclei and the core part of halo nuclei
in an unexpected way.
We discuss here the reactions of 280 and 60Ca as
examples of unstable nuclei with neutron skin. In t hecase of the 28 0+ 16 0 and 28 0 + 40Ca reactions, an enhancement of the fusion cross section is not seen compared to the reactions between stable nuclei, such as
16 0+ 16 0 and 16 0+ 40Ca. These results are consistent with the results of two-dimensional calculations. 3 )

·d

*2

16

Department of Physics, University of Tokyo
Service de Physique Theorique, CE Saclay, France

Since in the case of light nuclei, such as 280, the number of neutrons in the neutron skin is not large, forexample it is four in 280, and they are all looselybound, neutron transfer can easily occur compared tothe case with stable nuclei, although the separation ofthese neutrons from the core can easily occur comparedwith t he situation in stable nuclei. Therefore, neutrontransfer does not enhance the fusion cross section directly, and massive nucleon transfers are seen.
The situation is different in the case of reactionsof 60Ca. Similarly to the reactions of 280 , a significant difference in the fusion cross section between the
60Ca+ 40Ca and 40Ca+ 40Ca reactions is not seen. In
the case of the 60Ca+160 reaction, on the other hand,the fusion cross section becomes larger compared withthe 40Ca+160 reaction. We can also see that the crosssection of the neutron trtansfer of this reaction is notas large as that of the 60Ca+ 40Ca reaction. In thiscase, neutron flow can still easily occur due to the differnce in the neutron Fermi energies between 60Ca and160, similar to the 60Ca+40Ca reaction , although thechannels of the neutron transfer are not so favoured
energetically. The relation between neutron transfer
and fusion of these reactons is interesting. We are now
studying the mechanism of these reactions and the reactions of heavier neutron-rich nuclei in detail.
References
1) K.-H. Kim, T. Otsuka, and P. Bonche: J. Phys. G 23 ,
1267 (1997) .
2) E . Chabanat, P. Bonche, P. Hansel , J. Meyer, and R.
Schaeffer: Phys. Scr. T 56 , 31 (1995).
3) K.-H. Kim, T. Otsuka, and M . Tohyama: Phys. Rev. C
50 , R566 (1994).

RIKEN Accel. Prog. Rep . 35 (2002)

Resonance and continuum states in weakly bound systems
T. Nakatsukasa*l and K. Yabana*2[Hartree-Fock and random phase approximation]
100

Recent developments in radioactive beam techniques
enable us to access nuclei near drip-lines. The drip-line
nuclei are weakly bound finite fermion systems. One
would naturally expect that the continuum should betaken into account explicitly in any description of theirstructures and reactions.
Bound solutions of the Schrodinger equation for the
Hamiltonian, H = T + V, can be formally written as
1

W=--VW.
E-T

1

E - T + iT}

Vw.

(2)

ikr
f'V

f(n)-e - ,at r ---+ 00.

(3)r
Thus, with a complex potential of -iW(r) , the outgoing wave dampens as*1*2---:Jnper1uIbedSlf8flglh(e) aBC with r~l MeV°lLO~--~
20--===30~~~4~0~~50
E [MeV )For two-body systems, one may easily separate therelative coordinates from those of the center of mass.
Then, the OBC becomes rather trivial because this isessentially a problem involving a single degree of freedom. For many-body systems, however, it can be very
complicated to settle the OBC for many degrees of
freedom.
We present a method to simulate the OBC, which
we call the "absorbing boundary condition" (ABC) .1)
The Green's function with the OBC is written as
Eq. (2), where +iT} is an infinitesimal imaginary quanti ty (T} > 0). Now, we allow this imaginary part todepend on the coordinate and to be finite, +iW(r).
W(r) is taken to be positive far outside the system(at large r) and zero elsewhere. This means that, for
E > 0, the wave number, k, has a positive imaginarypart, +il'(r) , at large r. The outgoing wave defines its
asymptotic behavior as'ljJ(+)-APASlrenglh

50

(1)

Here, a Green's function, (E - T)-l, can be uniquely
defined, since the operator, E - T, is negative-definite.
Bound states are characterized by discrete spectra, En(n=0,1,2,"')'On the other hand , for continuum states, since E - T
has zero eigenvalues, we need to modify Eq. (1) into the
Lippmann-Schwinger equation. First, we need to add azero-eigenvalue solution of the E-T, <Po. Furthermore,in order to uniquely define the Green's function, (ET)-l, it is necessary to specify a boundary condition.
For usual physical situations, it is natural to adopt
an outgoing boundary condition (OBC) for scatteringwaves,

w=<Po+(a) BBC with r~l MeV

50

Physics Department, Tohoku University
Institute of Physics, University of Tsukuba

Fig. 1. Monopole response in 12C calculated with the BKN
interaction . Different boundary conditions are adopted;(a) BBC (Box boundary condition), (b) ABC, and (c)OBC.
ikr - "(r'ljJ(+)

f'V

f(n) er,

at r ---+ 00,(4)while the incoming wave diverges. Therefore, if we impose the vanishing boundary condition at large r, only
outgoing waves are allowed. Since the complex potential takes care of the boundary condition, we can solve
Eq. (2) with Wlbaundary = 0, instead of constructing
the OBC.
An advantage of the ABC is simplicity of its numerical calculation. We may solve scattering problems
in the same way as we do for bound states. Anotheradvantage is that the ABC easily implements a realtime calculation .2) Instead of taking an energy representation , we may calculate the time evolution of thequantum states directly. We have demonstrated thatthe real-time method with the ABC can properly takeaccount of the continuum in linear-response calculations. 2) In real-time calculations , it is very difficult tohandle the OBC explicitly. The disadvantage is that
the ABC cannot properly handle low-energy escaping
particles and a long-range Coulomb potential.
We have studied the continuum response of deformed nuclei with the OBC and ABC.3) The
monopole response in 12C is shown in Fig. 1 as an example. The results demonstrate that the ABC is able
to reproduce the same results as the OBC, except inthe vicinity of the threshold energy. See Refs. 2 and 3
for details.
References
1) R. Kosloff and D. Kosloff: J. Cornput. Phys. 63, 363(1986).
2) T. Nakatsukasa and K. Yabana: J. Chern. Phys. 114,
2550 (2001).
3) T. Nakatsukasa and K. Yabana: RIKEN Rev. , No. 39,
96 (2001).

17RIKEN Accel. Prog. Rep . 35 (2002)° 1 d £°lOB eTrlaxlae ormatoIon InoN. Itagaki,*l S. Hirose,*l T. Otsuka,*l S. Okabe,*2 and K. Ikeda[Cluster structure, Neutron-rich nuclei, Triaxial deformation]
The nucleus lOBe has been known to have a strong (3deformation due to the Q:-Q: core. However, triaxial deformat ion is also possible as a result of the dynamics ofthe two valence neutrons. This has been theoretically
discussed based on the deformed oscillator model,l) in
which a "y distortion of 34.8° has been predicted.
In our previous study of 10Be,2) all of the observed
low-lying positive- and negative-parity states could
be explained as combinations of three basic orbits(K1r = 3/2-, 1/2+, and 1/2-) of two valence neutrons around the two Q:-clusters . Here, the z-axis istaken to be the axis connecting two Q:-clusters. If we
adopt K1r = 3/2- or 1/2- orbits for the two valence
neutrons, there appear two rotational bands in low energy; one is dominated by the K = 0 intrinsic stru~
ture and the other by K = 2. The calculated two 2states of these bands can be related to the observed
first 2+ state at 3.358 MeV and the second 2+ state at
5. 958 MeV. It is therefore important to show how thetriaxial intrinsic configuration emerges in these states,
and how the orbits of the valence neutrons deviate fromaxial symmetry. Here, we d iscuss our calculat ion of theelectro-magnetic transition between these K = 0 and
K = 2 bands (B(E2 : K = 2 --+ K = 0)) as a signal ofa triaxial deformation. This transition is suppressed
when the orbitals are of pure axial symmetry. However, the orbitals may deviate from axial symmetry,when the valence neutrons are mutually more correlated and form a localized di-neutron pair due to theneutron-neutron interaction. The recoil effect of thevalence neutrons with respect to the Q:-Q: core thenplays a role to break the axial symmetry of the charge
distribution.
The total wave function is fully antisymmetrized andexpressed as a superposition of Slater determinantswith various configurations of the valence neutrons.
The Slater determinants are also superposed with respect to different relative distances between the two Q:
clusters. Projection to the eigen states of the angularmomentum (J) is numerically performed. All nucleons
are described by Gaussians with a common oscillator
set equal to 1.46 fm .
Parameter , s = v ~,2v
We estimate the degree of the triaxiality as a func. B(E2: 2i -2i) bt ion of the "y angle . The ratIO B(E2: 2i -Oi) ecomes 0.34 in our calculation, which agrees with the

*1

*2

18

Department of Physics, University of Tokyo.
Center for Information and Multimedia Studies, Hokkaldo
University

Davydov-Filippov model3 ) at around "y = 19° . Also,
B(E2: 2i -0+) calculated with the Davidov-Filippov
B(E2: 2i -Oi)model crosses with our result of 0.059 at around "y =17° and 22° . These results strongly suggest that lOBe
has a triaxial deformation of "y = 15°- 20°. Although
the Q:-Q: core is of axial symmetry and electric charge
exits only in the Q:'s, the recoil effect gives rise to achange from axial symmetry to the triaxial shape.
We can show triaxial deformation by artificiallyweakening the spin-orbit interaction. With decreasing
spin-orbit interaction, t he orbits of the valence neutrons deviate from the jj-coupling limit, and the dineutron configuration becomes important. Here, thesystem becomes 3 body-like and the B(E2 : 2t --+ 2t)
value drastically increases.
A similar di-neutron component has been discussed
in weakly bound systems with the so-called halo structure. For example , in 6He, in addit ion to t he shellmodel-like space, the model space of di-neutron+ 4He
has been shown to be important . This means t hat a
locally-correlated di-neutron wave function is important for describing the valence neutrons with smallbinding energy and a spatially extended distribution.
This is consistent with our discussion on the effectof varying the strength of the spin-orbit interaction.
Namely, when the valence neutrons with low-binding
energies have a halo structure, the contribution of thespin-orbit interaction between the core and the valence
neutrons becomes weak. Here, the valence neutrons
construct a di-neutron pair with spin singlet, by which
they can increase the spatial overlap between them andthe contribution of the attractive interaction. Therefore, it is very challenging to explore t he triaxial deformations in l2Be and l4Be, which have weakly boundneutrons as well as deformed cores.
References
1) M. Harvey and F. C. Khanna: in Nuclear Spec~ros~opy
and Reactions, Part D, Models of Light Nuclez, edlted
by J . Cerny (Academic Press, New York, 1975), p. 69 .
2) N. Itagaki and S. Okabe: Phys. Rev. C 61 , 044306(2000) .
3) A. S. Davydov and G. F. Filippov: Nuc!. Phys. 8 , 237(1958) .

RIKEN Accel. Prog. Rep. 35 (2002)

Equilateral-triangular shape in 14C
N. Itagaki,*l T. Otsuka,* l S. Okabe ,*2 and K. Ikeda[Cluster structure, Neutron-rich nuclei, Inversion doublet]
Recently, discussions of molecular states have been
extended to neutron-rich C isotopes. In our previous study,l) we applied our approach introduced for
Be isotopes to C isotopes, and the possibility of ana-a-a linear-chain configuration was pointed out. In
the present work, we investigate another kind of cluster structure in 14C, that is an equilateral-triangularshape of the 3a core. A state with this symmetry is expected to appear at a much lower in energy than thatin the linear-chain case. According to group theory,when the system has an equilateral-triangular configuration of 3a, a rotational band structure with K7r = 3appears. In 12C, the 3- state has been observed at
Ex = 9.6 MeV. From the theoretical side, it has been
analyzed based on many models that this state corresponds to the band head of the K7r = 3- rotationalband, and the triangular-symmetry of the 3a-cluster
is reflected in this band. 2) However, the presence of an
equilateral-triangular shape of 3a is not fully established for 12C, since the 4- and 5- states, which are
members of a rotational band starting from 3-, havenot been observed. Here, the 3- state is already above
the 3a threshold by about 2 MeV; therefore, large resonance widths are expected for the 4- and 5- states,
which makes any observation difficult. On the contrary, we investigate neutron-rich C isotopes and showthat this band structure is much more stabilized inenergy due to the attractive interaction among the valence neutrons around the 3a core.
A microscopic a+a+a+n+n model is introduced,
and the total wave function is fully antisymmetrized
and expressed by a superposition of basis states withdifferent relative distances between the a-clusters andvarious configurations of the valence neutrons aroundthe a-clusters. In 14C, two valence neutrons rotate
around the 3a-core symmetrically, just like covalent
electrons in molecules. To describe such a density distribution, we introduce two kinds of basis states: shellmodel-like and molecular-orbital basis states. In theshell-model-like basis state, the valence neutrons aredescribed as shell-model orbits around the center of 3a.
This basis state describes the neutron-density aroundthe center, and is valid for the describing the yrast
states with relatively small a-a distances. The lowest shell-model orbit of neutrons around 3a localizedon the xy-plain is pz (<I>(SM(pz?))' However, the twovalence neutrons are not only localized around the center of the 3a-triangle, but they also rotate around eacha-a pair. Therefore, we introduce another kind of thebasis state, the molecular-orbital basis state (<I>(MO)) ,where the orbit of the valence neutrons is described asa linear combination of orbits around each two-a pair.
This basis state is important when the a-a distance becomes larger. The model space is a+ 1oBe(a+a+2n) .
Due to mixing of the <I>(SM(pz)2) and <I>(MO) configurations , there appear two 3- states in the low energy region. From the second 3- state, a rotationalband structure comprised of the 32 , 4 1 , and 51 states
is calculated just around the loBe+a threshold. Furthermore, it is significant that the corresponding states
are experimentally observed in - 2.21 MeV (3-) and-0.34 MeV (4-) with respect to the loBe+a thresholdenergy. This situation is very different from that of

12C.
The calculation shows that the ground 0+ state,
the yrast 2+ state, and the 4+ state states (ot, 2t ,4t) around the loBe+a threshold energy fit into the
J (J + 1) rule. In this energy region, corresponding
states are also experimentally observed. The calculated electro-magnetic transition probabilities provethat these states are members of a rotational band.
The B(E2: 2t - t 4t) and the B(E2: ot - t 2t) values
are calculated to be 16.4 e2fm 4 and 38.1 e 2 fm4, respectively, and this ratio of 0.46 almost agrees with thewell-known value of 0.51 for a rigid-rotor. This result
suggests that a positive-parity rotational band withthe cluster structure also appears around the lOBe+athreshold energy.
We have shown that both of the positive-parity(band head is 0+) and the negative-parity (band headis 3-) rotational bands appear around the loBe+athreshold energy. Although the neutron configurations
are slightly different , these two rotational bands are
considered to comprise an inversion doublet structure.
References
1) N. Itagaki, S. Okabe, K . Ikeda, and 1. Tanihata: Phys.
Rev. C 64, 014301 (2001).
2) Y. Fujiwara, H. Horiuchi , K. Ikeda, M. Kamimura, K.
Kat6 , Y. Suzuki, and E. Uegaki : Prog. Theor. Phys.
Suppl. No. 68, 60 (1980).

*1 Department of Physics, University of Tokyo*2 Center for Information and Multimedia Studies, Hokkaido
University

19

RIKEN Accel. Prog. Rep. 35 (2002)

Description of the Gamow-Teller resonancewithin the phonon damping model t
N. Dinh Dang, T. Suzuki,* and A. Arima[NUCLEAR STRUCTURE, phonon damping model, Gamow-Teller resonance]
The phonon damping model (PDM) 1) has been extended to describe the damping of charge-exchange resonances. The formalism was applied to calculate thestrength distribution of the Gamow-Teller resonance in
90Nb. The obtained results in two versions PDM-l and
PMD-2 of the model, shown as the solid and dashedlines in Fig. 1, respectively, are found to be in reason-

PDM·1

3

-

PDM-2

-----

Dinh Dang et al. (1997)- •• •••••

Exp. by Wakasa at al. (1997)~

O~~----L--L~~::i..::::~~~-..i

o

10

20

30
40
E (MeV)

50

60

Fig. 1. Strength functions of the GTR in 90Nb. See text
for the notation.

Condensed from the article in Phys. Rev. C 64 , 027303(2001)
Department of Physics , College of Humanities and Sciences,
Nihon University

20

able agreement with the recent experimental data (fullcircles with error bars) 2) and with those of a previous
study with explicit microscopic coupling to 2p2h configurations using a realistic interaction (dotted line). 3)
References
1) N. Dinh Dang and A. Arima: Phys. Rev. Lett. 80,
4145 (1998); Nucl. Phys. A 636, 427 (1998); N. Dinh
Dang, K. Tanabe, and A. Arima: Phys . Rev. C 58, 3374
(1998).
2) T. Wakasa et al.: Phys. Rev. C 55 , 2909 (1997).
3) N. Dinh Dang, A. Arima, T. Suzuki, and Y. Yamaji:
Nucl. Phys. A 621 , 719 (1997).

RIKEN Accel. Prog. Rep. 35 (2002)

Phonon damping modelusing random-phase-approximation operators t
N. Dinh Dang and A. Arima[phonon damping model, random-phase approximation]
A fully microscopic interpretation of the phonon
damping model (PDM) is proposed. The phonon operator, which generates collective excitations, such as thegiant dipole resonance (CDR), is constructed from coherent particle-hole pairs. The phonon energy is determined as the solution of a dispersion equation within
the random-phase approximation (RPA). The phonon
structure is found in terms of the RPA X and Y amplitudes. The formalism has been illustrated by numer-

ical calculations wi thin a schematic model. The results of the calculations, shown in Fig. 1, demonstrate
the same feature of CDR as a function of temperature
obtained previously within PDM-l,l) which employs
structureless phonons.
References
1) N. Dinh Dang and A. Arima: Phys. Rev. Lett. 80, 4145
(1998); Nucl. Phys. A 636 , 427 (1998).

0.2-:::-<1>
6

14

r --

ro ---

120.15

r T - .......

(b)

10

Sa
<1>

0.1

6

-;::..

(......

UJ(jf 0.05

6

4

--~~

2
0

0

5

10

15

20

Ey (MeV)

25

0

0

2

-----

3

4

-------5

6

7

T (MeV)

Fig. 1. Temperature dependence of the strength functions (a) and width (b) of GDR. In (a): the solid,
short dashed , long dashed, dotted, dash-dotted and dash-double dotted lines are results at T = 0,1, 1.5, 2, 3, and 5 MeV, respectively. In (b): The thick solid, dashed , and dotted lines are the total
width r , the quantal width rQ, and the thermal width rT , respectively, as described in the text.

Condensed from the article in Phys . Rev. C 64, 024302(2001)

21

RIKEN Accel. Prog. Rep . 35 (2002)

Improved treatment of ground-state correlations:
Modified random-phase approximation t
N. Dinh Dang and V. Zelevinsky*[ground-state corrleations, random-phase approximation, superconducting pairing gap]
A method is proposed to improve the treatment of
the ground-state correlations in a finite Fermi systemcompared to the standard random-phase approximation (RPA) or earlier suggested renormalized RPA. 1- 5)
The correlations lead to nonzero quasiparticle occupancies in the ground state. The method employs
modified quasiparticles obtained by a canonical transformation of the usual quasiparticles explicitly involving the quasiparticle occupation numbers. A set of
equations is derived , which allows one to determine
these occupation numbers along with the RPA modes.
The formalism is illustrated with the Lipkin-MeshkovGlick model, and a model for superconducting pairing at finite temperature. With the new approach,
the ground-state correlations are significantly reduced,
the energy of the first excited state becomes closer

Condensed from the article in Phys. Rev. C 64, 064319(2001)
Department of Physics and Astronomy, Michigan State University, USA

22

to the exact solution around the region where the
RPA collapses, and the superconducting gap decreases
monotonously instead of having a sharp phase transition. We discuss the effective equivalence of the interaction effects and the variation of temperature for the
ground-state correlations.
References
1) K. Rara: Prog. Theor. Phys. 32, 88 (1964).
2) D. J. Rowe: Phys. Rev. 175 , 1293 (1968).
3) P. Schuck and S. Ethofer: Nucl. Phys. A 212 , 269(1973).
4) F. Catara, N. Dinh Dang, and M. Sambataro: Nucl.
Phys. A 579, 1 (1994).
5) N. Dinh Dang and A. Arima: Phys. Rev. C 62 , 024303(2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Determination of the matter surface distribution of unstable nuclei
A. Kohama, R. Seki,* A. Arima, and S. Yamaji
NUCLEAR REACTION: matter density distribution of nuclei , least-square fitting, proton-j[nucleus elastic scattering
Experimental facilities for unstable nuclei have been
receiving much attention in t he recent years. RI-Beam
Factory (RIBF) is under construction at RIKEN in
J apan, and the Rare Isotope Accelerator (RIA) facility is being proposed in the U.S. Such facilities will
provide much data for t he physics of unstable nuclei.
Among various aspects of unstable nuclei, one of interest is the one-body matter density distribution, p(r).
The distribution is a fundamental quantity of nuclei,
and will serve as an important measure to test how well
we understand nuclear structure. It is perhaps an appropriate time to make a close investigation as to how
well one could determine the one-body matter density
distributions from the various kinds of data that are
expected to emerge from the facilities.
As a concrete example, we have examined the typesof experiments that are under consideration at RIBF.
Unstable nuclei are often characterized as those with alarge surface region generated by loosely bound valance
nucleons .1) Of course , we must treat the entire regionof the distribution, but will pay particular attention
to determining the surface region, which is our maininterest.
To this end, we have demonstrated that the surface region of the matter-density distribution can be
determined well, even by the relatively low-intensity
beams expected to be available at the upcoming radioactive beam facilities. 2 ) The density distribution isdetermined in a model-independent way 3,4) by generating pseudo data and by carefully applying a statistical and systematic error analysis. We have illustrated
how the determination deteriorates in the central region of the density, as the quality of data decreases. 2 )We have applied our analysis to the determinationof the matter density distribution of a neutron-rich nucleus (Fig. 1) , in which some of the parameters in t hebasis functions are fixed to those of the neighboring
stable nucleus. This would allow a practical procedurein which one can apply the information of the density
distribution of a stable nucleus to an analysis of its
unstable isotopes. 2 )References
1) 1. Tanihata et al.: Phys. Rev. Lett. 55 , 2676 (1985).
2) A. Kohama, R. Seki , A. Arima, and S. Yamaji: RIKEN
Rev. No. 39 , 155 (2001).

104

~.c

!!

..,c
"..,
b

103

x"/DOF: 1.333

102

p + ""'Hi

10 1

Tp [GeV]: 1.0470

100

10- 1

10- 2
0

10

15

20

25

30

8em [deg]

2.0

1.5

,

!

1.0

-.:-

.'&:~

0 .5

0 .0

-0.5

4

0

r [1m]

Fig. 1. Results of the least-square fitting for the pseudodata set group C of 78Ni, which corresponds to a nuclear beam intensity of 10 [S - l] at RIBF. R (= 10 [fm])is the maximum distance to probe nuclei by the experiment , and M (= 10) is the number of basis funct ions.
We use here the Gaussian basis function.5 ) a) 25 fitted cross sections (solid curve) and all of t he pseudodata (cross with bar) . b) 25 fitted density distributions (solid curve) , and the original distribution (dottedcurve). The density distributions are drawn in the formof 1'2 p(1').

3) J. L. Friar and J. W. Negele: Adv. Nucl. Phys. 8 , 219(1975).
4) A. Kohama, S. Yamaji, R. Seki, and A. Arima: RIKEN
Accel. Prog. Rep. 34 , 19 (2000).
5) M. Kamimura: Phys. Rev. A 38 , 621 (1988).

Department of Physics and Astronomy, California State
University, Northridge , and W. K. Kellogg Radiation Laboratory, California Institute of Technology, USA

23

RIKEN Accel. Prog. Rep. 35 (2002)

Observation of new neutron and proton magic numbers t
R. Kanungo,!. Tanihata, and A . Ozawa[Magic number, separation energy, beta decay Q value, excitation energy]
Our concept of a nucleus as having a shell structure
is born out of the existence of magic nucleon numbers
where nuclei exhibit extra stability. So far, the observation of t hese magic numbers , has been based mostly
on the study of nuclei on and near the stability line ,and were found to be N = 2,8, 20 , 50, 82, 126, and likewise for Z.
Over t he past decade, however, our knowledge about
nuclei has vastly expanded with the scope of studying unstable nuclei. This reveals a considerable modification of the shell structure when one moves toa neutron-rich region. Recently, Ozawa et al. haveshown the presence of a new neutron magic number, N = 16,1) based on a systematic study of thesingle-neutron separation energy in neutron-rich nuclei. These observations suggest the possibility of achange of shell closures in a wide range of neutron-richnuclei.
A magic number can be observed as sharp discontinuites in certain observables, such as t he Q value ofbeta decay (Q{3- ), the single-neutron separation energy (Sn), and the excitation energies of the first excited state (E~~t) of even-even nuclei.
Breaks in the systematics of these three quantities
show the existence of new magic numbers at Z = 16
and N = 30 in neutron-rich regions of the nuclear
chart. Shell closure at N = 32 is also observed. The
recently reported new magic number , N = 16,1) was
also reconfirmed in this a nalysis from new view points.
After extending such systematic studies to the protonrich region of the nuclear chart, we observe breaks int he systematics at N = 16, Z = 16, a nd N = 6.
A summary of the new neutron and proton magic
numbers a nd their relevant positions in the nuclear
chart is presented in Fig. 1. It can be observed that theCondensed from the article in Phys. Lett. B 528 , 58 (2002)

24.11•••• • •

..
N

!I

20

11111

W

•• ••

I
I
I
~=tl

••

, I

10

••••
•
•••

.~

~··~6tJ

1

N=30

L-

~ break in

Qp-

III:break in Sn
L-

-

1st
~ break in Ee•

N:16~ break in Sp

-

10

=~2

disappearanceof usual magic
numbel20

30

N

Fig. 1. Summary of new magic numbers and their locationsin the nuclear chart.

magic numbers on either side of the stability line arequite identical and only differ for stable nuclei. Such asymmetrical situation is indicative of the importance of
the isospin-dependent nucleon-nucleon interaction. It
has recently been pointed out by Otsuka et al. 2 ) thatthe spin-isopin part of the nucleon-nucleon interaction
is important for explaining the N = 16 magic number. The present observations over a wide range are inconformity with such a possibility.
References
1) A. Ozawa et al.: Phys. Rev. Lett. 84, 5493 (2000).
2) T. Otsuka et al.: Phys. Rev. Lett. 87, 082502 (2001).

RIKEN Accel. Prog. Rep . 35 (2002)

Possibility of an enlarged core structureof N == 15 neutron-rich nuclei t
R. Kanungo, I. Tanihata, and A. Ozawa[Halo, Glauber model, interaction cross-section]
The recently measured interaction cross-section datafor 22N, 23 0, and 24F in a 12C target at relativistic energies have been analysed in a few-body Glauber model
approach. The conventional fixed core-plus-neutronmodel for halo nuclei is unable to explain the observed
enhanced cross section for these nuclei by any selection of the neutron orbitals. Microscopic calculations,like those in the many-body Monte-Carlo shell model,
relativistic mean field theory and cluster model, arealso shown to fail to describe the large difference in
the interaction cross section between 220 and 23 0. A
possibility of core enlargement is suggested in these
nuclei.

Condensed from the article in Phys . Lett. B 512 ,261 (2001)

25

RIKEN Accel. Prog. Rep. 35 (2002)

Fission-barrier heights estimated by a nuclear mass formula
H. Koura*[Spontaneous fission, Binding energies and masses]
Our group recently constructed a nuclear mass formula 1 ,2), which we refer to as the KUTY formula, composed of a gross part and a shell part. For the shellpart, we first calculate the proton and neutron spherical shell energies using modified Woods-Saxon typepotentials. 3) The shell energy of a deformed nucleus
is expressed as the minimum sum of an appropriate
mixture of the above-mentioned spherical shell energies and an average deformation energy with respect tothe deformation parameters. This mass formula gives
ground-state masses and shapes for nuclei ranging from
4He to superheavies. The standard deviation of thecalculated masses from the experimental masses of the
1995 Mass Evaluation4) is about 680 keV.
Although our mass formula is constructed by considering only the equilibrium nuclear shapes, the potential energy surface for spontaneous fission can becalculated by the same method as that used for obtaining the shell energies. The fission-barrier height isdefined as the highest saddle point from the groundstate shell energy towards the prolate shapes. In thisreport we limit the nuclear shape to the Q2, Q4, Q6
deformations in the range -0.2 < Q2 < 0.5.
We show the energy surfaces against the nuclear deformation for some superheavy nuclei in Figs. 1 and 2.

280 112Fig. 1. Calculated energy surface of 280 11 2. The groundstate shape of this nucleus is at about 02 = 0.11 and
04 = -0.06.
300 120

Fig. 2. Calculated energy surface of 300 120. The groundstate shape of this nucleus is at about 02 = 04 = 0.0.
Advanced Research Institute for Science and Engineering,
Waseda University

26

130 140 150 160 170 180 190 200
130

130

120

120

110

110

e 100

100

90

90

f'..J
Q;
.0

E
::J

c:
c:
0

c...

130 140 150 160 170 180 190 200
Neutron number N

Fig. 3. Fission-barrier heights for even-even nuclei. The
neutron-rich nuclei located below the solid line may
have a higher saddle point in the region 02 > 0.5.

For the nucleus 280 112, the height of the fission barrier
is only about 2 MeV and its width is relatively narrow.
The spontaneous-fission half-life is consequently expected to be rather short for this nucleus. On the contrary, for the nucleus 30°120, the fission-barrier height
is about 8 MeV, and this width is fairly wide. Therefore, the spontaneous fission of this nucleus is expected
to have a very long partial half-life, much longer thanthe Q-decay half-life.
We show the fission- barrier heights in Fig. 3 for eveneven nuclei in the 84 S Z :s; 130 and 126 :s; N :s;
200 ranges. The nuclei located below the solid line in
Fig. 3 may have a higher saddle point in the region
Q2 > 0.5 because we limited the range in the present
calculation. In this figure, the "hill" of the barrierheights of the nuclei near 304 122 is seen. The heights ofthese nuclei are about 8 MeV or more. On the contrary,the "basin" of the barrier heights of the nuclei near278 110 is also seen. These heights are about 2 MeV.
There are also other neutron-deficient nuclei having
relatively low fission-barrier heights.
References
1) H. Koura et al.: Nucl. Phys. A 674, 44 (2000) .
2) H. Koura et al.: RIKEN-AF-NP-394 (2001).
3) H. Koura and M. Yamada: Nuel. Phys. A 671 , 96
(2000).
4) G. Audi and A. H. Wapstra: Nuel. Phys. A 595 , 409(1995).

RIKEN Accel. Prog. Rep. 35 (2002)

Estimation of alpha-decay half-lives withphenomenological formulas
H. Koura,* T. Tachibana,* and M. Yamada*[Alpha decay, Binding energies and masses]
We estimate alpha-decay half-lives Ta. (s) from experimental Qa.-values (MeV) with a phenomenologicalformula. The parameter values in the formula are adjusted for the experimental Ta. and Q a. of the EvaluatedNuclear Structure Data File (ENSDF), 2000 version.1)
The alpha-decay half-life is written as

Ta. = loge 2/(Neo ll X P),(1)

where Neoll is the collision frequency of an a particle toa potential wall and P is the penetration probability.
Here, we consider two phenomenological formulas.
One is the Viola-Seaborg formula 2) with an even-odd
hindrance term h,logIO Ta. = (aZ + b)/ /Q: + (cZ - d) + h,(2)

where a, b, c, d are adjustable parameters.
Another formula is derived from the penetration
probability of an a particle for a spherical Coulomb
potential, while neglecting such higher order terms as

(3)
where

R = ToAi:e + do, TO = 1.08 fm ,(4)subscript D indicates a daughter nucleus, and Neoll anddo are adjustable parameters.
As for h, we adopt a simple expression,
(5) .

with

oeo = {!

for even-even nuclei,
for odd- A nuclei,
for odd-odd nuclei.

(6)Here, ho is an adjustable parameter.
The values of the fitted parameters for Eq. (2) area = 1.55261, b = 0.73247, c = - 0.21669, d = 31.9949,
and ho = 0.56718 for Qa. and Ta. in MeV and second, respectively. The root-mean square (RMS) deviation of log Ta. from the experimental ones is 0.3625 forAdvanced Research Institute for Science and Engineering,
Waseda University

20

even·even(120 nuclei)

E;b1O
0

o LogTa.,p+ LogTIlc. ,d.....J0-----ci.

Jl
] 0

~

'OJ) -10.....J60

80 100 120 140
Neutron number N

Fig. 1. Experimental and estimated logTo< using Eq. (3)(upper). Differences between the above two log To<(lower) . All data are for even-even nuclei.

120 even-even nuclei. The RMS deviation is 0.7708 for
151 odd-A nuclei and is 0.9845 for 63 odd-odd nuclei.
Because 10 d roughly corresponds to the collision frequency Neoll of the a particle, which should be about
10 20 - 22 Hz, the value of d is too large.
The values of the fitted parameters for Eqs. (3) and(4) are Neoll = 10 20 .05 Hz, do = 2.0 fm , and ho =0.61410. The values of Neoll and do are reasonable.
The RMS deviations for even-even nuclei, for odd-A
nuclei and for odd-odd nuclei are 0.3512, 0.7500 and
0.9802 , respectively. Figure 1 shows the differences between the experimental and estimated Ta. of Eqs. (3)and (4) for even-even nuclei. This figure shows a distinct discontinuity at N = 126 because of the magicity. At N = 102 74Hf102) a large discrepancy is seen.
This nucleus is isolated from the other eve-even nuclei, and has a relatively larger deformation than theothers.
By using these formulas we can estimate the Ta. forunknown nuclei with estimated Qa. from a mass formula. In Ref. 3 we predict the unmeasured Ta using
Eq. (2) with Qa from the mass formula. 4)eReferences
1) Evaluated Nuclear Structure Data File (ENSDF), 2000
August version, communicated through Nuclear Data
Center, Japan Atomic Energy Research Institute.
2) V. E. Viola and G. T. Seaborg, Jr.: J. Inorg. Nucl.
Chern. 28, 741 (1966).
3) T. Horiguchi et al.: Chart of the nuclides 2000 (Japan
Atomic Energy Research Institute, Tokai-mura, 2001).
4) H. Koura et al.: Nuel. Phys. A 674, 44 (2000); RIKENAF-NP-394 (2001).

27

RIKEN Accel. Prog. Rep. 35 (2002)

A software supporting experimental planfor new elements synthesis
K. Hashizume, *1 Y. Aritomo,*2,*3 and M . Ohta*1[Superheavy element, Synthesis index]
In estimating the evaporation residue cross section
for producing superheavy nuclei, there are many ambiguities. A theoretical prediction can inevitably havean error of one order of magnitude or more.
According to knowledge obtained from our recent
systematic analyses,1-5) the essential part which controls the absolute value of the evaporation residue crosssection is decomposed and classified into several components. Their sum is defined as a Synthesis Index(SI). An investigation of each term of SI gives an explanation of why a certain projectile-target mass combination is favorable or not for producing a superheavy element among various candidates of the entrance channel. SI is composed of the following terms. 2,5) Eachterm is expressed as an exponent of 10. Therefore,
for example, in term (3), if the shell correction energychanges by 1 MeV, the evaporation residue cross section changes by one order of magnitude.
In an actual calculation, when we treat a reaction in
the over-barrier energy, it is assumed that the maximum cross section is realized just above the energy of
the Bass barrier, i.e., E'B + !J.E, where !J.E (> 0) is
typically about several MeV.
(1) The index for the formation probability is given by
log1o PjOT'
3.2 + (1/ J!J.E + 5 + 0.085)(Z - 100)
1 + exp( ((X - 0.5) /0.075)
which is valid for Z ~ 102. For Z < 102, the effect of
the liquid-drop part of the fission barrier becomes more
important and the above formula should be modified .
(2) Since an increase in the shell correction energy by
one MeV results in a one order enhancement of thesurvival probability, the contribution to the index is-6 s h e ll, where 6s h e ll is the ground-state shell correctionenergy.
(3) The rotational enhancement factor as a function ofground-state deformation (!3r) is expressed by 2.0{1 +exp((0.15-!3r)/0.015)} -1, where the factor 2.0 means
the maximum contribution when the ground-state of
the compound nucleus is strongly deformed.
(4) The contribution to the cross section depends on
the neutron number of the compound nucleus (N).
The index for the neutron number dependence is(N -No )/6, where No is an arbitrary reference number.
The factor 6 appearing in the denominator is derived
*1
*2

*3

28

Department of Physics, Konan University
Department of Physics , University of Tokyo
Flerov Laboratory of Nuclear Reactions , JINR, Russia

from the result that a six-unit increase of the neutron
number in a compound nucleus enhances the survival
probability by one order of magnitude. This is because, when the neutron number of compound nucleus
increases , the neutron separation energy decreases and,as a result , the survival probability increases in competioin with the fission process.
(5) The energy dependence of the survival probability
is derived from a systematic analysis . The index for
excitation energy (EB + !J.E) is -0.3(EB +!J.E - Eo) ,where Eo is also an arbitrary reference energy.
The factor 0.3 means that, in the superheavy mass
region, when the excitation energy of a compound nucleus increases by 3- 4 IvleV, the survival probability
decreases by one order of magnitude due to the chanceof another multiplication of r n/r tot. That is to say,when the excitation energy increases, the number of
evaporation steps also increases. Since the survival
probability is proportional to rr~1 (r~) /r~~t), it decreases along with the increase of m, where m is thenumber of evaporation steps.
(6) When !J.E is negative, i.e., when the incident energy is under a barrier, the barrier penetrability (TB )should be taken into account. TB is usually calculated
by using an inverse parabola with strength nw.
The index for the penetrability is log1o T B , TB ={I + exp( - 2n!J.E /liw)} -1 . Summing up these terms ,we define the Synthesis Index for !J.E > 0 (the case ofover barrier energy) as follows:
SI = log1o PjOT'(Z, N, (x, E'B + !J.E)- 6s h ell + 2.0{1 + exp((0.15 - !3r)/0.015)}-1+ (N - N o)/6 - 0.3(E'B +!J.E - Eo).
The calculation of SI will be available on the Internet
home page of RIKEN from December, 2001.
References
1) M. Ohta: Proc. Workshop Fusion Dynamics at the Extreams, Dubna, 2000-5 (World Scientific, 2001) , p. 110.
2) M. Ohta, Y. Aritomo , V. Zagrevaev , and E .
Proc. Int . Conf. on Exotic Nuclei
Cherepanov:(EXON2001), Irkutsk, Russia, 2001-7, published fromWorld Scientific.
3) Y . Aritomo and M. Ohta: submitted to Phys. Rev. C.
4) V. 1. Zagrebaev, Y. Aritomo, M. G. Itkis, Yu. Ts.
Oganessian, and M. Ohta: Phys. Rev. C 65 , 014607(2001).
5) M.Ohta: invited talk in ND2001, Tsukuba, Oct. (2001).

RIKEN Accel. Prog. Rep. 35 (2002)

A two-step model for fusion and synthesis of superheavy elements
C. W. Shen,*l G. Kosenko,*2 and Y. Abe*3[superheavy element]
We propose a theoretical framework describing thewhole reaction process of synthesizing superheavy elements , starting from the encounter of a projectile anda target up to residues of the elements, through theformation of compound nuclei.1 ,2) Since cooling processes of compound systems are well known and established, though there are ambiguities in the parameters in statistical codes, an essentially unknown part isthe formation process of compound nuclei. In lighter
systems it is rather simple and just passing over the
Coulomb barrier, or quantum-mechanical barrier penetration; however , in massive systems it is not theend of the process, because there is a so-called conditional saddle point or a ridgeline standing outside of
the spherical ground state and inside of the Coulomb
barrier. Therefore , we have two steps: firstly, overbarrier up to the contact of two nuclear surfaces and,secondly, the evolution of a pear-shape formed by contact of the projectile and the target into the sphericalshape, overcoming the conditional saddle point.
The first step is treated by the classical trajectorymodel extended so as to include the fluctuation associated with friction. If we employ the surface friction
model proposed by Gross and Kalinowski, we obtain afully damped state at the contact point, i.e., the incident energy is completely dissipated into the internalenergy. In other words, the momentum is in the Boltzmann distribution. The orbital angular momentum isalso dissipated to form a sticking limit. A solution of
the first step, thus provides a sticking probability ofthe projectile and the target.
The second step is the shape evolution of di-nucleus
complexes, which is again to be described by a stochastic equation, i. e., a Langevin equation for shape degrees of freedom. In the framework of the two-centerparameterization, at least two parameters are neces. sary: the distance between the two centers and themass asymmetry. By solving the Langevin equation
with the so-called one-body wall-and-window formula
as friction , we obtain the formation probability of thespherical shape for various incident momenta. The
obtained formation probabilities are folded with theBoltzmann distribution of the initial momentum togive rise to the final fusion probability.
Combining the statistical decay calculations withthe code HIVAP, we obtain the residue cross sectionsof superheavy elements. 48Ca+244pu system is taken
*1
*2

*3

Department of Nuclear Physics, China Institute of Atomic
Energy, China
Department of Physics, Omsk University, Russia
Yukawa Institute for Theoretical Physics, Kyoto University

1.0
0.8
0.6
go

~ 0.4
CL

0.2
0.0

·10

0

10

20

30

40

50

60

70

80

Ec .m . - B tus ' MeV

Fig. 1. Sticking probability shown as a function of the incident c.m. energy relative to the barrier.

10'

10'

10'

IE""" = E.... (MoUer)/3 I
11

'i:i

.sc:
.~

10"

10"

Q)

C/)

'"'"0 10"

0

10"

10.10

10.11
30

40

50

60

E'(MeV)

Fig. 2. Shell correction energy of 1/3 of M011er's prediction used to reproduce the order of magnitude of theexperimental cross section.

as an example. Figure 1 shows the sticking probability
at the contact point after the first step. Figure 2 shows
the residue cross sections for xn reactions as well as thefusion excitation function. The experimental cross section to be compared is 1 - a few pb of the 4n channel at
E* ~ 35 MeV, which is apparently in good agreementwith the calculated results shown in Fig. 2.
References
1) Y. Abe, C. W. Shen, and G. Kosenko: AlP Conf. Proc.
597, 209 (2001).
2) Y. Abe, C. W. Shen, and G. Kosenko: Proc. 5th Int .
Conf. on Dynamical Aspects of Nuclear Fission, CastaPapiernicka, Slovak Republic , 2001-10, to be published.

29

RIKEN Accel. Prog. Rep . 35 (2002)

44Ti: Its initial abundance in Cassiopeia A and
its detection possibility in SN 1987A with INTEGRALt
Y. Mochizuki[electron-capture decay, supernovae , ry-ray line astrophysics]
44Ti is a pure orbital-electron capture decay isotope; in laboratories its half-life is measured for neutral
atoms. Thus, the laboratory half-life value may not bedirectly applied to astrophysical environments where
44Ti is possibly in ionized states.
Mochizuki , Takahashi, Janka, Hillebrandt, andDiehl 1) have argued that the electron-capture rate of
44Ti could be significantly reduced from its laboratory value because a high degree of ionization may becaused by reverse shock in a young supernova remnant. For the supernova remnant Cassiopeia A (hereafter, Cas A), they concluded that retardation of t hedecay increases the current 44Ti-activity by a factorof 1.5- 2.5, which yields a better compatibility between
the COMPTEL observation of the 1.16 MeV line activity associated with the 44Ti decay of t his remnant
and the supernova model predictions of the initial 44Ti
abundance . However , they pointed out that the above
possibility is strongly subject to the radial distributionof 44Ti in the ejecta.
Recently, Hughes et al. 2 ) and Hwang et al. 3 ) reported map of the X-ray emitting ejecta in Cas A ,which includes Fe and Ca. Since 44Ti is considered toexist along with Fe and it ultimately decays to 44Ca,
the distributions of Fe and Ca may be referred to as
indicators of the position of 44Ti in the ejecta. In thepresent paper I reexamined the ionization effect of 44Ti
on its initial abundance in Cas A, discussed in the paper,1) with newly obtained observational information.
It is shown that under certain conditions the ionization of 44Ti increases its current activity and accordingly removes any apparent discrepancies between
44Ti production in the supernova explosion as inferredfrom COMPTEL ry-line measurements and theoretical
expectations from the current supernova nucleosynthesis models (see Fig. 1).
On the other hand, detection of the 44Ti ry-line fromthe supernova remnant SN 1987A is the one of prime
targets for the INTEGRAL mission, a gamma-ray astronomy satllite planned to be launched in 2002. The
ionization effects of 44Ti in SN 1987 A are also briefly
discussed here.
If we assume no reduction of the ,6-decay rate the
44 Tl. amounts of 1.5 x 10- 4Me:) (Me:) shows the solar'mass), suggested from the fitt ing of the late lightcurveof SN 1987 A , would produce on Earth a ry-ray flux of
3 x 10- 6 cm- 2 S-1 . This is close to the sensitivity
limit of INTEGRAL.
f"'-.Jf"'-.J

Extracted from the article of Nucl . Phys. A 688 , 58e (2001)

30

3.5 ,----.,----.----"-T---r------.
Ionization.. -*"

~ 3.0
1"

o
T"""

'-'"'

.. -......

~=2.0........ "'Yi~d derived.-.. ..... _ - - Observed values... .... : _ - (No lonizatipn.) - .-.....: .. ~ --.-:.:.::::::- .......

3.0

.5

SchOnfelder et al. 2000

y-ray photon Flux (1 0-5cm-2 s-1 )Fig. 1. Initial yield of 44Ti at the time of the explosion of
Cas A as a function of the , -ray photon flux , by which
the observed result from the COMPTEL experiment 5 )is indicated by the arrow . WLW95 indicates a theoretical result 6 ) of the initial 44Ti yield predicted for thetype of supernova explosion like Cas A. The apparent
discrepancies are reduced by taking the history of the
44Ti ionization into account. Details are found in anarticle of Nucl. Phys. A 688, 58c (2001).

Contrary to the Cas A case, a simple linear analysis
shows that the retardation of 44 Ti decay decreases its
activity for a sup ernova remnant that is younger thant he lifetime of 44Ti, i. e., ~ 100 yr. This arises from thelinear dependence of the activity on the decay rate.
Recently, helium-like and hydrogen-like ions of 0 ,Ne, Mg, and Si have been observed in SN 1987A with
the Chandra X-ray observatory.4) If 44Ti is in thehydrogen-like ionization state, it is expected from a
linear analysis that the activity is reduced by ~ 50% in
the case that assumes no retardation of the decay rate.
This means that the expected flux from SN 1987A may
lie below the detection limit of INTEGRAL.
References
1) Y . Mochizuki et al.: Astron. Astrophys. 346 , 831(1999) .
2) J. P. Hughes et al.: Astrophys. J. 528, L109 (2000).
3) U. Hwang et al.: Astrophys . J. 537, LU9 (2000).
4) D. N. Burrows et al. : Astroph/0009265.
5) V. Schonfelder et al.: Astron. Astrophys. Suppl. 143,
145 (2000).
6) S. E. Woosley et al.: Astrophys. J. 448, 315 (1995).

RIKEN Accel. Prog. Rep. 35 (2002)

Formation of nuclear "pasta" in cold neutron star mattert
K. Iida, G. Watanabe,* and K. Sato*[Dense matter, Fission instability, Proton clustering, Neutron stars]
Nuclear matter exhibits the coexistence of a liquid
phase with a gas phase at subnuclear densities, due
to the attractive force responsible for nuclear binding. Such a coexistence is believed to be present in
the outer part of a neutron star. 1 ) Since gravitational
coupling is far smaller than Coulomb coupling, thestar's gravitational stability requires nuclear matterto be neutralized by electrons. The resulting electrically neutral matter is usually referred to as neutronstar matter. At sufficiently low temperatures, relevant
to neutron star interiors, long-range Coulomb interactions force the system to separate periodically into
liquid and gas segments of macroscopic size, adding acrystalline property to the liquid-gas coexistence. As
the electron chemical potential increases with increasing pressure, a system in /3 equilibrium has the liquid
phase neutron-enriched and leaves the gas phase almost free of protons.
At zero temperature, it is believed that the energetically favorable configuration of the mixed phase possesses interesting spatial structures; 1) the liquid (gas)phase is divided into periodically arranged parts ofroughly spherical, rod-like, or slab-like shape, embedded in the gas (liquid) phase and in a roughly uniform electron gas. Hereafter, we refer to these parts
composed of the liquid and gas phases as 'nuclei' and'bubbles,' respectively. Recent calculations, performed
within the Wigner-Seitz approximation using specificnuclear models, indicate that at a density of about
10 14 g cm- 3 , which is rather small compared withthe saturation density of symmetric nuclear matter,Ps ~ 2.7 X 10 14 g cm- 3 , the spatial structure changes
from a bcc Coulomb lattice of roughly spherical nuclei to a two-dimensional triangular lattice of rod-like
nuclei. With the density increased further , it is transformed into a layered structure composed of slab-like
nuclei and bubbles. Next, a two-dimensional triangular lattice of rod-like bubbles and a bcc Coulomb latticeof roughly spherical bubbles appear in turn. Finally,
at a density of about Ps/2, the system dissolves into
uniform nuclear matter. These changes of the spatial structure, accompanied by a reduction of the total
surface area, are governed by competition between theelectrostatic and surface energies. Since slabs and rods
look something like lasagna and spaghetti, the phaseswith positional order of one and two dimensions areoften referred to as nuclear "pasta."
In a separate study,2) we more extensively calculated

the corresponding equilibrium phase diagrams for zerotemperature neutron star matter at subnuclear densities . From a typical compressible liquid-drop model for
nuclei , we predicted that the phases with rod-like nuclei and with slab-like nuclei are energetically favoredin the density regime just below Ps and at zero temperature; it is thus important to consider how these nuclei
are formed. Such formation requires the simultaneous
migration of an infinite number of nucleons, in contrast to the case of ordinary chemical reactions. This
prevents the nuclear system from crossing the energy
barrier formed between the initial and final states in
configuration space via quantum tunneling. Instead,"pasta" formation can be driven by instabilities withrespect to fluctuations around the initial state.
In this work, we examined the kinds of instabilities
that are involved in the formation and decay of rod-likeand slab-like nuclei at zero temperature. As such, we
first note an instability with respect to quadrupolar
deformation of spherical nuclei, as originally investigated in the context of nuclear fission by Bohr and
Wheeler. We also consider an instability with respect
to proton clustering in uniform matter. This clustering is induced by the isospin symmetry energy. At
an instability point that the system reaches during decompression, the gain due to this energy compensates
for the gradient and Coulomb energies produced by
the resulting inhomogeneities, and hence a phase with
nuclei of some form appears .
We extend these considerations to other changes innuclear shapes. The possible instability with respect
to proton clustering in planar and cylindrical nuclei
tends to divide each nucleus into nuclei of lower dimension, while the possible fission-like instability ofslab-like and rod-like nuclei tends to lead to the formation of uniform matter and slab-like nuclei, respectively. Using a typical nuclear model, we find thatplanar and cylindrical nuclei are stable with respect
to deformation-induced fission and proton clustering.
This suggests the possibilities that such nuclei persist
beyond the equilibrium transition points, and that thesize of the stellar region containing them exceeds theequilibrium prediction.
References
1) C. J. Pethick and D. G. Ravenhall: Annu. Rev. Nucl.
Part. Sci. 45, 429 (1995).
2) G. Watanabe, K. Iida, and K. Sato: Nucl. Phys. A 676,
455 (2000).

Condensed from the article in Prog. Theor. Phys. 106, 551(2001)
Department of Physics, University of Tokyo

31

RIKEN Accel. Prog. Rep . 35 (2002)

Recent developments in an experiment to measure nuclear
half-lives relevant to the astrophysical r-process
M. A. Famiano, S. Nishimura, Y. Nishi, R. N. Boyd,* and 1. Tanihata[r-process, ,6-decay, Nucleosynthesis]
Many nuclei of astrophysical interest and their significant reactions have yet to be studied experimentally. In particular, astrophysical processes which produce nuclei heavier than iron are postulated to include
reactions of nuclei far from stability. In the r-process,the rate at which nuclei progress from low mass tohigher mass , and (to a lesser extent) the nuclei throughwhich they progress (the r-process path) depend on the,8-decay rates of those nuclei. These rates are expected
to be much more than 1 S-1.1) An experiment has been
constructed to measure fast ,6-decay rates, allowing one
to study nuclei further from stability, and to hopefully
push the frontier of knowledge closer towards the rprocess path. Because of the low production yields ofthe nuclei of interest, it is useful to simultaneously produce and measure as many of these nuclei as possible.
The current detector system, shown in Fig. 1, consists of five implantation target layers, each containing 11 targets. Nuclei are implanted into anyone of
the target layers (used to facilitate charge separation).
The targets are rotated out of the beam line into layers of position-sensitive detector arrays. Each array isconstructed of two orthogonal layers of plastic scintillator fiber arrays and a NaI scintillator for detecting
coincident gamma rays. A correlation will be madebetween the position of the detected ,6 particle andthe beam implantation position in the target. The
target wheel can be rotated to an accuracy of 0.05°,
corresponding to a position accuracy of about 0.2 mm,much less than the position resolution of the fiber detector arrays. The time difference between production
and detection is the decay time of the implanted ion.
The rotation of the target wheel also serves the pur-Fig. 1. Target wheel apparatus and detector array (exposedfor clarity).

pose of reducing the buildup of long-lived nuclei. Since
the target wheel has 11 positions, then the sequence of
implantation - followed by a rotation - must occur
11 times before a target returns to its original position
and is implanted again. For example, for a lifetime of
200 ms , any given target is implanted only once every
4.4 s (200 ms x 11 rotations x 2 steps per rotation).
The minimum lifetime that can be measured, limitedby the rotation speed of the wheel, is on the order of
100 ms for rotation between the beam and the detector
array.
The fiber arrays (Fig. 1) must maximize the efficiency, while minimizing the cross-talk between adjacent pixels. For this reason, multi-clad scintillatingfibers were chosen. Also, the flexibility allows for easeof installation and manipulation, because the resulting
system requires at least 20 such fiber arrays in close
proximity. Each layer is divided into 16 channels. The
overlap between an X channel and a Y channel createsa pixel, each of which is 4 mm square. One layer has
an absolute efficiency for ,6 detection of about 50%,
resulting in a total efficiency of 25%. Cross-talk andposition sensitivity tests were conducted using a collimated 90Sr source. Any cross-talk between adjacentfibers would result in events in adjacent fibers. It was
found that the cross-talk between adjacent pixels is
negligible, while most of it appears to be on the glass
surface of the photo-multiplier tubes to which the arrayis coupled, and comprises only a very small percentageof the single count rate, and is thus not expected to bea problem. The position resolution of these detectors
is a single pixel, enabling the location of the detectedparticle to be known with little uncertainty.
U sing various simulation packages, the target configuration can be optimized to stop isotopes of interest and their neighboring isotopes. Likewise, particle
identification is also done using the time-of-flight of thesecondary particles.
The second stage of this experiment is planned forearly 2002 with a heavier primary beam. An initial
data analysis, followed by improvements to the detection system, will allow measurements of new half-lives.
The possibility for determining the level structure, in
addition to the half-lives of proton-rich nuclei, exists
as well, permitting a large growth in our knowledge ofastrophysically interesting nuclei.
References
1) G. Wallerstein et al.: Rev. Mod. Phys. 69, 995 (1997).

Physics Department , Ohio State University, USA

32

RIKEN Accel. Prog. Rep. 35 (2002)

r-process In prompt supernova explosions
K. Sumiyoshi,*l M. Terasawa,*2,*3 G. Mathews,*4 T. Kajino,*2,*3 S. Yamada,*5 and H. Suzuki*6[Nucleosynthesis, r-process, Unstable nuclei, Supernova]
A recent increase of experimental data of unstable
nuclei towards the r-process path gives strong motivations to study the nature of r-process nucleosynthesis.
It is now crucial to discuss the impact of the structure
and reaction of unstable nuclei around the r-process
path on nucleosynthesis in the astrophysical environment of the r-process.
Meanwhile, the findings of r-process elements in
extremely metal-poor stars by astronomical observations provide important clues to pin down astrophysical sites for the r-process. 1 ) Those data of very oldstars strongly indicate supernova explosions of massive stars as a unique origin of the r-process. A recent
analysis further suggests more than one kind of supernova origin, which might be linked with the mass
range of presupernova stars. The abundance patternof the r-process may be different depending on the supernova mechanism: a delayed explosion and a prompt
explosion, corresponding to massive and less massive
stars, respectively. For massive stars, the r -process ina neutrino-driven wind has already been studied. 2)
To pursue whether less-massive stars contribute to
the r-process, we have studied r-process nucleosynthesis in neutron-rich ejecta from a prompt supernova explosion of a low-mass (11 M 8 ) progenitor. 3) A prompt
explosion can occur for low-mass supernova progenitors with small iron core masses and small rates of electron capture. To model a prompt explosion , we have
performed a general relativistic hydrodynamic simulation of adiabatic collapse and bounce 4) using a relativistic nuclear-matter equation of state. 5) The electron fraction (Ye ) during the collapse was fixed at theinitial-model value. The size of the inner collapsingcore was then large enough to enable a prompt explosion to occur in the hydrodynamical calculation.
While adopting the calculated trajectories ofpromptly ejected material , we explicitly computed theburst of neutronization due to electron captures on free
protons in the photodissociated ejecta after passage ofthe shock. The thermal and compositional evolutionof the neutron-rich material ejected from near the surface of nascent neutron star was obtained. These wereused in nuclear reaction network calculations to evaluate the products of r-process nucleosynthesis. We have
solved the nuclear reaction network 6) including about
*1
*2

*3
*4

*5
*6

N umazu College of Technology
Department of Astronomy, University of Tokyo
National Astronomical Observatory
Department of Physics, University of Notre Dame, USA
Institute of Laser Engineering, Osaka University
Department of Physics, Tokyo University of Science

10' (
10. 2
10. 3
<1.l

u

c:

10-4

~

"0

c:

::I

.0

«

10.5
10-6
10- 7
10-8

100

150

200

Mass number

Fig. 1. Calculated final abundance of r-process elements
ejected from a prompt supernova explosion of an 11 Me:)
star (line) compared with the solar abundance (dots).

3000 nuclei up to the neutron drip line to follow theabundance of the nucleosynthesis products. We sum
up the products from ejected materials to evaluate thetotal amount of r -process elements and their pattern.
F igure 1 shows the total abundance of the r-process elements produced in the ejected material from a prompt
explosion.
We find that, unlike in earlier studies of nucleosynthesis in prompt supernovae, t he amount of r-processmaterial ejected per supernova is quite consistent withobserved galactic r-process abundances. Furthermore,
the computed r-process abundances are in good agreement with the solar abundances of the r -process elements for A > 100. This suggests that prompt supernovae are promising r-process sites. Such events
may be responsible for the abundances of the heaviest
r-process nuclei.
References
1) C. Sneden et al.: Astrophys. J. 533 , L139 (2000).
2) K. Sumiyoshi , H. Suzuki, K. Otsuki, M. Terasawa, andS. Yamada: Pub. Astron. Soc. Jpn. 52 , 601 (2000) .
3) K. Sumiyoshi, M. Terasaw8;, G. J. Mathews, T . Kajino,
S. Yamad a, and H. Suzuki: Astrophys. J. 562 , 880(2001).
4) K. Sumiyoshi, H. Suzuki, S. Yamada, and H. Toki: submitted to Nucl. Phys. (2001).
5) H. Shen, H. Toki, K. Oyamatsu, and K. Sumiyoshi:
Prog. Theor. Phys. 100, 1013 (1998).
6) M. Terasawa, K. Sumiyoshi , T. Kajino, G . J. Mathews,
and 1. Tanihata: Astrophys. J. 562 , 470 (2001).

33

RIKEN Accel. Prog. Rep. 35 (2002)

r-process nucleosynthesis in the type-II supernova modelwith a neutron star mass of t"'V 1.4M8
M. Terasawa,*I ,*2 K. Sumiyoshi,*3 T. Kajino,*2 and G . Mathews*4[r-process, supernova, neutron star, neutron capture]
It is generally believed that the r-process occurs under explosive conditions at very high neutron density,
high temperature, and high entropy. It has been discussed that core-collapse supernovae could provide themost likely environment for the r-process. It is now
commonly accepted that a massive Fe core explodes
with the help of neutrino heating in a supernova explosion of, at least, a massive star. l ) Because of theconversions of neutrons to protons, this strong neutrino
flux, however, hinders the r-process, and the r-process
cannot occur in even a supernova model with very
high entropy, ~400 (in units of the Boltzmann constant, k B ) .1,2) Therefore , it is necessary that the dynamical timescale of the explosion is much shorter than
the timescale of the neutrino interactions not to disturb the r-process. So far, some authors showed thatthe successful r-process can occur in the fast neutrinodriven wind model, even with relatively low entropy,~200.3) However these models assumed the neutronstar mass , MNS
2.0M0 (M0 is the solar mass), although the typical MNS is considered to be ~ 1.4M0
based on observations.
The timescale of the explosion model that showsa successful r-process pattern is under 10 msec. 3) On
the other hand , the timescale of the r-process is abouta few seconds. Therefore the r-process is considered
to occur in the outer boundary region just behindthe shock wave. 4) We should study more about theouter boundary condition, which is given by the outerboundary pressure (Pout) in simulations. Thus , wesimulate the neutrino-driven wind with the typicalneutron star, MNS = 1.4M0 , and investigate the dependence of the abundance pattern on Pout.
We summarize the key quantities in Table 1. Here,
Tout , Y ex, out and Ys eed ,out stand for the temperature(in the unit of 10 9 K) and the abundances of alphaparticles and seed nuclei at the outer boundary, respectively. In each model, the dynamical timescale ofthe explosion is almost the same and sufficiently short,a few 10 msec. The r-process nuclei are synthesized by
the a-process and the r-process. At first, neutron-richseed nuclei with mass number ~ 100 are made by thea-process. After that, the r-process starts from theseseed nuclei and makes heavy r-process elements.
From Table 1, Tout becomes lower as Pout becomes

Table 1. Summary of parameters and key quantities.
P out[dynjcm 2 ]
10 22
10 21
10 20

Tout

Y Q ,ou t

Y seed , out

1.3
0.7
0.3

0.177
0.198
0.202

2.1 x 10 3
1.2 x 10- 3
3.7 x 10- 4

10- 4
OJ

() 10- 5~
co"0§ 10- 6
..0

<t:

t'V

*1

Department of Astrophysics, University of Tokyo*2 National Astronomical Observatory
*3
*4

34

Numazu College of Technology
Depa rtment of Physics, The University of Notre Dame , USA

Mass Nu mber
Fig. 1. Final abundance pattern .

lower because the matter flows farther from the neutron ~tar. When Tout is high, Yex,out is small andY seed out is large. This is because the a-capture reactio~s are sensitive to the temperature and proceed
rapidly because of the high temperature. The large
value of Yseed ,out means a decrease in the number ofneutrons per one seed. As a result, it becomes difficult to synthesize heavy elements by the r-process fora large Pout value. In Fig. 1, we show the result of nucleosynthesis calculations and the solar r-process abundance pattern. From these reasons, we find that theheavier nuclei are synthesized with decreasing the Poutvalue. By the comparison with the solar abundance,
the solid line is most likely in the case of 1.4M0 .
References
1) S. E. Woosley, J. R. Wilson , G. J. Mathews , R. D.
Hoffman, and B. S. Meyer: Astrophys. J . 433 , 229(1994).
2) B. S. Meyer: Astrophys. J. Lett. 449, 55 (1995).
3) K. Sumiyoshi , H. Suzuki , K. Otsuki, M. Terasawa, andS. Yamada: Publ. Astron. Soc. Jpn. 52, 601 (2000).
4) M. Terasawa, K. Sumiyoshi, T. Kajino, I. Tanihata, and
G . Mathews: Astrophys. J. 562, 470 (2001).

RIKEN Accel. Prog. Rep. 35 (2002)

Neutrinos from supernova explosions and protoneutron stars
H. Suzuki,*l K. Sumiyoshi,*2 s. Yamada,*3 and H. Toki*4[supernova, neutrinos, protoneutron star]
U sing a new numerical EOS (equation of state) table calculated by Shen et al.,!) we performed numericalsimulations of supernova explosions and protoneutronstar cooling. The EOS is based on the relativistic mean
field theory, and the parameters in its Lagrangian havebeen chosen to reproduce the experimental propertiesof both stable and unstable nuclei. Furthermore, thenumerical table covers such a wide range of thermodynamical quantities (temperature, 0- 100 MeV; electron
fraction, 0- 0.56; density, 105.1- 1015.4 g/cc) that it isvery useful for supernova simulations.
As a first step towards full simulations of core collapse and the subsequent explosion in massive stars,
we have studied the adiabatic collapse of stellar cores.
The initial core structures were taken from numericalstellar models of Woosley's group and Nomoto's group.
The succeeding dynamics of the cores was calculatedwith a spherically symmetric, general-relativistic hydrodynamical code developed by Yamada. 2) In order
to explore the characteristics of Shen's EOS simply,
we neglected electron capture and neutrino transport
in the cores. This approximation could be used toestimate the upper limit of the core mass, which explodes promptly. As a result, we found , in precollapse
cores, compositional differences between our models
and those with popular Lattimer & Swesty's EOS: nuclei with neutron number greater than 40 are moreabundant and free protons are less abundant in the
cores with Shen's EOS. This might result in a reduction of the electron-capture rates during the core collapse, and would be preferable for successful prompt
explosions. Hydrodynamical simulations without electron capture and neutrino transport for various initial cores show that light cores (:S l.4Me:» explodepromptly with bounce shock, while massive cores can
not explode. We thus confirmed that even with Shen's
new EOS the bounce shock wave alone cannot explodemassive cores.
Another implication of our numerical simulations
is r-process nucleosynthesis. If the core explodes
promptly, neutron-rich material would be ejected andr-process nucleosynthesis might occur in the ejecta. Although this possibility was investigated formerly byHillebrandt et al., they used an artificial distributionof electron fraction and concluded that too many rprocess nuclei are synthesised to reproduce the observational data. On the other hand, we evaluated numerically the electron fraction of each shell of ejecta whileconsidering the electron capture on free protons after
the passage of shock. In collaboration 3) with Terasawa, nucleosynthesis in each shell was studied using
the calculated trajectory in the density-temperatureplane and the electron fraction of each shell. The resultant relative abundance of heavy nuclei up to A--200 has good agreement with the observational data.
In addition, our estimation of the total abundance of
r-process nuclei ejected from past prompt supernovae
indicates that there is no inconsistency between theobservation and our numerical results. We point out a
new interesting idea that relatively light r-process elements are formed in delayed supernovae, while heavy
nuclei are synthesised in prompt supernovae.
We also investigated the quasistatic evolution of protoneutron stars with a numerical code including neutrino transfer (M G FLD scheme) . Using the new EOS
table 1) covering a very wide thermodynamic regime,
time evolution for even 50 seconds could be studied.
Compared with simulations using Wolff 's old EOS , thecentral temperature of the protoneutron star and theaverage energy of emitted neutrinos become somewhat
lower, but the qualitative feature does not change. A
lepton-rich initial model and a hot initial model werealso studied, and we obtained the result that the average energy of non-electron-type neutrinos is not muchhigher than that of electron-type antineutrinos at thelate stage of a supernova neutrino burst. This fact
might affect the implication of SN1987 A data on theneutrino oscillation parameters. More comprehensive
studies including the collapse/explosion phase and convection/ accretion effects are required.
References
1) H. Shen, H. Toki, K. Oyamatsu, and K. Sumiyoshi:
Nucl. Phys. A 637, 435 (1998).
2) S. Yamada: Astrophys. J. 475, 720 (1997).
3) K. Sumiyoshi, M . Terasawa, G. J. Mathews, T. Kajino,
S. Yamada, and H. Suzuki: Astrophys. J. 562 , 880(2001) .

* 1 Tokyo University of Science
*2
*3
*4

N umazu College of Technology
Institute of Laser Engineering, Osaka University
Research Center for Nuclear Physics , Osaka University

35

RIKEN Accel. Prog. Rep. 35 (2002)

10

160

Shell-Model calculations for 7 andwith microscopic AN andbN effective interactions
S. Fujii, R. Okamoto,* and K. Suzuki*[Hypernuclei, Shell model, Effective interaction]
One of the challenging problems in theoretical studies of A hypernuclei is to describe their properties,
starting from hyperon-nucleon (YN) and nucleonnucleon (NN) interactions given in free space. The nuclear shell-model approach would be one of the promising methods for this problem over a wide range of mass
numbers of A hypernuclei. In shell-model calculations,however, we need to introduce an effective interaction
because of a limited model space. The microscopic
derivation of an effective interaction for nuclear shellmodel calculations is a fundamental problem for a microscopic understanding of nuclei.
We have proposed a method for a microscopic
description of A hypernuclei within the frameworkof the unitary-model-operator approach (UMOA).1 ,2)
UMOA is a many-body theory that leads to an energyindependent and Hermitian effective interaction withthe property of decoupling. We have applied UMOA
to calculations of A single-particle energies in ~7 0 and~l Ca, using various YN interactions given by the Nijmegen and the Jiilich groups. Some reasonable results
have been obtained, such as small spin-orbit splittingsof A compared with those in nuclei, though the results
depend considerably on the YN interactions employed.
Lately, we have been making shell-model calculations for ~60 in addition to ~70, using the effective interaction derived in previous works. Furthermore, weare trying to introduce a L:N effective interaction into
the shell-model calculation. In the shell-model calculations of A hypernuclei made so far , the effects of the
L:N channel have been treated as renormalization intoa AN effective interaction in many cases. The degrees
of freedom of L: have not been treated explicitly in theshell-model calculations. Therefore, it is interesting toderive an effective YN interaction which includes not
only the AN channel, but also the L:N one, and to apply
such an effective interaction to shell-model calculations
for A hypernuclei.
As the first step, we have examined the effect of
the L:N channel on A single-particle energies in ~7 O.
Figure 1 shows the dependence of the A single- particle
energies for the Nijmegen soft-core (NSC) 89 and the
NSC97f YN potentials on the the model-space size of
the L:N channel. The number py for Y = A, L: in Fig. 1
is defined astheharmonic-oscillator(1)

quantum

numbers,

Department of Physics, Kyushu Institute of Technology

36(NSC971. PA- 8)

E(M.rev:.!....)_ __1:0..:.:.,,_----!:.:(N:=.:SC=89:.:.!:.PA!>..:-..:!,8)- - - 3/2
-5

-5
-10

_ _ -_'/2

-10
-15

'/i
i\N012345

i\N012345

1\

1\

(a)

(b)

r

Fig. 1. Calculated energy levels in 0 for the NSC97f (a)and the NSC89 (b) potentials as a function of PE. Theenergy levels with "AN" are the results without the I:Nchannel in the model space.

{ny, ly} and {nN , IN} , of the hyperon and the nucleon, respectively. As for the value of PA, we fix it
as PA = 8 which is a sufficiently large number to see
the pI:-dependence. We can see that the results for
the NSC97f (the left-hand side of Fig. 1) are almost
stable for the values of PI:. This suggests that therenormalization of the effects of the L:N channel into
the AN effective interaction is very good. On the other
hand , the results for the NSC89 (the right-hand side ofFig. 1) imply that we should take a number larger than
3 as PI: to obtain convergent results. This is mainly
because of the strong L:N-AN coupling effect of the
NSC89 potential.
A high-resolution gamma-ray spectroscopy experiment for ~60 is in progress at BNL. Fine structuresreflecting the properties of the underlying YN interactions should be obtained. Therefore , it is of great
importance to investigate the origin of the fine structure from a microscopic point of view. We are now
performing a shell-model calculation for ~60 , using not
only the AN effective interaction, but also the L: one.
The calculation result for ~60 will be reported elsewhere in the near future.

Referencespy = 2ny + ly + 2nN + IN ,

with

~o

1) S. Fujii, R. Okamoto, and K. Suzuki: Nucl. Phys. A
651 , 411 (1999); Nucl. Phys. A 676 , 475 (2000).
2) S. Fujii, R. Okamoto, and K. Suzuki: Prog. Theor.
Phys. 104, 123 (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Nuclear K bound states in proton-rich systems to be formed by(K- , 7r-) reactions through A * as a doorway
T . Yamazaki and Y. Akaishi *[kaon, strangeness few-body systems]
We propose to form very exotic nuclear K boundstates in proton-rich systems using (K- ,7r-) reactions.
The structure of K-pp, K-ppp and K-pppn was predicted to be deeply bound by variational calculations
based on KN interactions, which we derived previously
to predict deeply bound K-ppn and K-ppnn. 1 ) Figure 1 shows the calculated KN and K-nucleus potentials and the bound levels in A (1405), Hand H for
the K- -p, K - -pp and K- -ppn systems, respectively.

k

k

E·
[MeV)

1800

1700
E(1660)1600
A(1520)1500

A(1405)+1t-

I
I
I
I
I

___t__ .
K-p(B) +1t-

1400~
_E_1t_

1300
An
1200

Fig. 2. Energy diagram relevant to the formation of K
bound states in (K-, 1T - ) reactions through A(1520) +1T - resonance as a doorway.

Fig. 1. Calculated KN and K-nucleus potentials and boundlevels: A(1405), kH andfor K- -p, K- -pp and K-ppn systems, respectively. The nuclear contraction effect is taken into account . The shaded zones indicate
the widths. The ~1T and A1T emission thresholds area lso shown.

kH

Table 1. K nuclei produced by (K - , 1T - ) .
TargetK nucleus[B, r]

d3He

kH = K-pp[38,51]4He
9Be

kHe = K-ppp
i<He = K - pppn
kBe = K-paa

The reason for this deep binding is due to a strong attraction between K- and p, which helps to contract thenucleus (unbound without K-) to which K - is bound.
A possible formation process for K bound statesin the (K- , 7r-) reactions was proposed; that is , theelementary production of A(1405) and A(1520) inn(K-, 7T-)A * propagetes in the nucleus and serves asa doorway for the formation of K bound states (seeFig. 2).
Table 1 shows light target nuclei and K bound states
to be formed through A doorways by the (K -, 7r - ) reaction, as well as for the calculated binding energies(B in MeV) and widths (f in MeV) with nuclear contraction.
References
1) Y. Akaishi and T. Yamazaki: Nucl. Phys. A 684, 409c
(2000).
2) Y. Akaishi and T. Yamazaki: Phys. Rev. C, in press.

Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)37

RIKEN Accel. Prog. Rep. 35 (2002)

Coulomb logarithm in the electron-cooling process
H. Amemiya, T. Tanabe, and T. Katayama[Electron cooling, Coulomb collision, Coulomb logarithm, Ion beam]
In the conventional theory l,2) of electron cooling, theCoulomb logarithm is assumed to be a constant. It isconsidered to be only weakly dependent on the relative
velocity between an ion and electrons. However, thisassumption is not always accurate for ions with a velocity comparable to, or less than, the electron thermalvelocity where the most efficient cooling is expected. In
the present work, the cooling rate is calculated more
precisely by taking the Coulomb logarithm as a variable.
The loss rate of the momentum P of an ion travelling with a velocity V in electrons with a velocity
distribution f(v) is
dP =_47r Q JL V.f(v)dv .
m
e U
U2
'
dt

V
U

au
av'

(1)

where Q = NeZ2e4/(47rEo)2, Ne is the electron density,
Z is the charge of ion , U = (V2 + v 2 - 2V v cos e) 1/2 ,Le = In().1 p) is the Coulomb logarithm, ). is the Debye length, p is the minimum access distance given by
p = Z e2/(47rEomV2), m is the reduced mass given bym- 1 = m e -1 + M- 1 , M is the ion mass, and e, m e are
the electron charge and mass, respectively.
We seek a potential <l> which satisfies- -a<l> = - -47rQ J L -V . - 1 f(v)dv.
av

e U

m

U2

(2)

Using the fact that Le consists of constant and variable parts as

L c = Lo + In(~) 2; Lo '" In(6ND/Z),(3)

where ND = (47r/3)Ne).3 , s = (2K,Telm )I /2, we find<l>(V) = - 47rQ J (Lo + 2) + In(UIs)2 f(v)dv.
m
U

(4)

dEli

dt

=

dP

V· dt

-V· Vv<l>(V).

=(5)

The rate of energy broadening is given by integrating
V· (VU) over f(v) asJdE~= ~ 47rQ
L (~ U)f( )d
dt
2 MeV
v v,

(6)

where ~v is the Laplacian.
Defining another potential,

147rQ
w(V) = - 2 m

38

J

LeUf(v)dv ,dE~ = _ m [.6. V !l/(V) + 3 . 47rQ J f( v) dV ]

(7)

M

dt

47rQ
.6. v !l/(V) = <l>(V) - ----:;;;:

J

m

U

1
Uf(v)dv.

(8)
'
(9)

We also define dimensionless functions of 0: = Vis ,(PI and ¢2, as<Pl (O:) = - J(U~s)f(V)dV,(10)<P2 (0:) = -In(UIs)2(U Is) f (v) d v.

(11)

J

While <PI is a conventional function,I,2) <P2 is a function for a modification. The relations similar to theelectrostatics 3 ) for the case of constant L e, .6. y tJ! = <l>and ~ Q<P = f( v) , are modified by Eq. (9) and .6. Q<Pl =f(v) , ~ Q<P2 = In(0:2)f(v) respectively, for the case ofvariable Le.
Then , (5) and (8) become

dEli

cit = -Co: {(Lo + 2)vrQ<Pl(0:) + vr Q<P2 (0:)},dE~m

cit = -c M {L o ¢1 (0:) + ¢2 (0:)},

(12)
(13)

where C = 47rQ Ims . Note that these relations hold forany forms of f(v). If Eqs. (12) and (13) are integrated
for the ion velocity distribution F(V), we obtain thecooling and broadening rates of an ion beam. In thiscase, it is sufficient to calculate <PI and <P2, since V Q<Pl
and V Q<P2 disappear by partial integration.
As typical cases of f (v) , an isotropic Maxwellian distribution (non magnetic case) and a two-temperature
distribution (frozen case) have been dealt with, where
besides the elliptic function K (k) a logarithmic-elliptic
function L(k) is introduced, i.e.

L(k) =

Thus, the rate of energy cooling becomes-

we can express

7r/2 In (1 - k 2 sin 2 e) de

1

.
(14)
o
j1-k 2 sin 2 e
It has been found that the cooling rate of the previous theory l ,2) is overestimated for ions with velocities
larger than (2K,Telm)1/2 while the energy broadening
rate is underestimated for all ion velocities. More details on cooling and energy broadening rates using <PI
and <P2 are forthcoming.

References
1) H. Poth: Phys. Rep. 196, 135 (1990).
2) I. N. Meshkov: Phys. Part. Nucl. 25, 631 (1994) .
3) B. A. Trubnikov: in Reviews of Plasma Physics, Vol. 1,
edited by M. A. Leontovich (Consultants Bureau, NewYork , 1966), p. 105.

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of the effect of a non-equilibrium liquid D2+T2
mixture in muon-catalyzed dt fusion
K. Ishida, K . Nagamine, T. Matsuzaki, N. Kawamura,*1 S. N. Nakamura,*2 Y. Matsuda, M. Kato, *3 H. Sugai,*3
M. Tanase,*3 K. Kudo,*4 N. Takeda,*4 and G. H. Eaton*5[Muon catalyzed fusion, tritium, fusion neutron]
One of the critical steps in the muon catalysis fusion cycle (J.LCF) is the formation of muonic molecularions. The dtJ.L-formation rate (Adt/-L) has to be much
faster than the muon decay rate (AO = 0.45 x 106 S-l)for the J.LCF to catalyze many dt-fusions. Concerning
dtJ.L formation by a collision of tJ.L with D2 or DT, aresonant formation mechanism has been proposed to
explain an unexpectedly large formation rate. 1) In thisprocess, the dtJ.L-molecular binding energy resonantly
goes to the vibrational and rotational energy of the
final compound molecule ([(dtJ.L)dee]* etc.) and any
small energy difference between the initial and final
states is compensated by the kinetic energies of theparticipating atoms and molecules.
In contrast to the nonresonant (Auger) process, theresonant process depends on the temperature as wellas the states of the participating atoms and molecules.
Among various dtJ.L molecular formation rates, A~/-L- X 'tJ.L(F) + DX ~ [(dtJ.L)xee], (x = d, t, X = D, T)

where F is the hyperfine state, A~t/-L - d for a singlet tJ.L
colliding with D2 molecule was calculated to make adominant contribution at low temperature. However,so far, the temperature dependence of the dtJ.L formation rate, which was measured mostly on equilibrated
targets , is not fully explained by the calculation. Thus,
an experiment which can measure the contributions of
D2 and DT molecules separately is essential to understand the resonant mechanism correctly, and would
give us a key to improving the catalysis efficiency.
When we mix D2 and T 2, an equilibrium state isreached due to the reaction D2 + T2 ~ 2DT. It is
known that this reaction is rapid (order of 10 minutes)
in the room-temperature gas phase, while it is slow (afew days) in the low-temperature liquid. Thus , if wemix D2 and T2 in the liquid phase and observe how
the J.LCF neutron yield is affected as the equilibrium isgradually reached , we can separate the contributionsof D2 and DT molecules to dtJ.L-molecule formation.
The experiment was performed at the RIKEN-RAL
Muon Facility. D2 gas and T2 gas were separately prepared and solidified at 15 K one after another in thetarget chamber. The target was then warmed up to
*1

*2
*3

*4
*5

High Energy Accelerator Research Organization (KEK)
Tohoku University
Japan Atomin Energy Research InstituteNational Institute of Advanced Industrial Science and Technology
Rutherford Appleton Laboratory, UK

20 K to become the liquid state. Figure 1 shows themeasured neutron disappearance rate (An), neutron
yield per muon (Yn ), J.LCF cycling rate (Ac = AnYn/¢)and the muon loss per cycle (W = (An - AO)/¢A c) as afunction of time after D2 +T2 mixing. Data were taken
for the liquid state (open circles in Fig. 1) up to 110
hours after D2 +T2 mixing. The target gas was thenwarmed up to room temperature so that the equilibration would proceed completely. The gas was liquefied again to obtain data for a fully equilibrated target(filled circles in Fig. 1).
It can be seen that the cycling rate was enhanced
by 30% in the non-equilibrium state just after D2+T2
mixing, while the muon loss probability was almost
constant. These results are well explained by taking
into account the resonant mechanism and the equilibration process with a time constant of 56 hours.
A preliminary analysis shows that A~tj.t - d rv 4A~t/-L-t ,which is consistent with the theory, at least qualitatively. A detailed analysis is in progress.
~ 1.6

20

40

60

80

100

,20

140

160

~ 140
>-c

100

6O ~~~~~~~~~~~~~~~ ~t~:" ~:=::J .jj
o

~

40

60

60

100

,~

~o

gO

Time after liquefaclion [h]Fig.!. Measured neutron disappearance rate (An), neutron
yield (Yn ), cycling rate (A c) and muon loss per cycle(W) as a function of time after D2 and T2 mixing.

References
1) E. A. Vesman: Zh. Eks. Theo. Fiz. Pis. 5, 50 (1967).
(Sov. Phys. JETP Lett. 5, 91 (1967).)

39

RIKEN Accel. Prog. Rep. 35 (2002)

Electron-RI collider at MUSES:
A possible electron spectrometer
T. Suda, S. Kato,*l K. Maruyama,*2 and I. Tanihata[Electron-RI collider, charge distribution, high resolution spectormeter]
A collider of electrons and radioactive ion beams,
the eRI collider, planned for the second phase of the
RIKEN RI Beam Factory project, aims to explore thenot-yet-determined charge distribution of many unstable nuclei by elastic electron scattering, and at providing one of the most fundamental observalbles to investigate exotic nuclear structures of unstable nuclei farfrom the stability line.
As we have previously reported,1- 3) the feasibility ofthe eRI collider has been demonstrated and the accessible nuclei at the collider have been identified under the
expected luminosities. In addition to this study, therequirements for an electron spectrometer to measure
the elastic scattering cross section has already beenclarified.
Since the elastic-scattering cross section of unstable nuclei is to be measured, the excitationenergy resolution at the Nucleus-Rest (NR) frame of!:::..WNR rvO.1 MeV will be indispensable. This requirement is equivalent to the momentum resolution of 10- 4
for electron detection in the Collider (COL) frame,
which requires a high-resolution spectrometer insteadof a medium-resolution large-acceptance spectrometer,
such as CLAS at JLAB.
In this report, we present a possible electron spectrometer for the collider experiments currently underdiscussion. As shown in Fig. 1, it is a QD-type spectrometer, whose Q magnet is one of the optical elements of the collider. The collision takes place inside
the Q magnet , and scattered electrons appear from theside of the magnet. The pole shape of the Q magnet
at the exit of both sides is designed to provide a dipole
field in order to give a further kick to the scatteredelectrons. The design of this special Q magnet is also
underway with this spectrometer design.
The advantage of this 'beam-line' spectrometer isthe ability to cover a very forward scattering angle,
such as a few degrees, without any serious interferencewith the collider, where the Mott cross section rapidly
becomes large . Another advantage is to have a wide
scattering angular range which covers a wide range ofthe momentum transfer, qNR, at a time.
This spectrometer has a scattering-angle coverageof 200 mrad in the horizontal plane. The gap of thedipole is 25 cm, corresponding to a vertical angular
acceptance of 100 mrad. In addition, the expected finite interaction region in the longitudinal direction (~
*1

*2

40

Yamagata University
Kitasato University

Fig. 1. Proposed electron spectrometer for the eRI collider
of MUSES.

10 cm) is well covered by its acceptance. By adjusting
the collision point in the longitudinal direction , thisspectrometer can cover a different scattering angularrange from 100 to 700 mrad. The first-order momentum resolution is 1/7200, which is very close to therequirements mentioned above.
At electron scattering facilities, such as MAMI and
JLAB, a vertical-bending spectrometer is often employed. This is not only because one can rotate thespectrometer to a very backward angle, but also because measurements of the momentum and scattering
angle are decoupled, at least in the first-order optics.
We , however , employ a spectrometer which bends
scattered electrons horizontally, in order to realize alarge scattering-angle coverage. This configuration requires the insertion of a position detector ("detector1" ) between the Q and D magnets in addition to the
focal- plane detectors ("detector 2" and "detector 3")
for determining of the momentum and scattering angle.
To avoid multiple-scattering effects in the inserted detector, which distort the scattering-angle information ,the detector must have a sufficiently small material
thickness.
References
1) T. Suda, K. Maruyama, and 1. Tanihata: RIKEN Accel.
Prog. Rep. 33, 52 (2000).
2) T. Suda, K . Maruyama, and 1. Tanihata: RIKEN Accel.
Prog. Rep. 34, 49 (2001).
3) T. Suda: A proposal for RIKEN RI Beam Factory, F0123 (http) /rarfaxp.riken.go.jp;-suda/ eRI/ proposal. pdf,
2001).

RIKEN Accel. Prog. Rep . 35 (2002)

High-spin isomeric beam line
T. Kishida, H. Watanabe, E. Ideguchi, T . Kubo, Y. Yang, M. Ishihara, S. Yamamoto, Y. Gono,*lT. Morikawa,*l T. Tsutsumi,*l T. Fukuchi,*l S. Motomura,*l H. Tsuchida,*l O. Kashiyama,*l K. Saitoh,* l
M. Shibata,*l A. Odahara,*2 Y. Zhang,*3 X. Zhou ,*3 B. Cederwall,*4 T. Back,*4 and D. Bucurescu*5
NUCLEAR REACTIONS, 160(l36Xe,7n)145mSm, 13C(l45mSm,xn), Radioactive beams,][Isomer
A high spin isomeric beam line has been constructed
at RIKEN utilizing the inverse kinematics of fusionevaporation reactions. The secondary beams of fusion
reaction residues produced in a gas target are collectedwith a superconducting solenoid and transported tothe secondary target position through the RIPS. The
principle of separation between the secondary beams
and the primary beam is based on the magnetic rigidity
and the charge state distributions. For better separation, a charge stripper section is placed between the
superconducting solenoid and the RIPS. Rectangularslits of variable widths and positions have been placedat the dispersive focal plane F1, in order to reduce theintensity of the primary beam transported to F3.
In a recent experiment, a high spin isomeric beam of
145mSm with a spin of 49/2n and a half-life of 0.96 f.LS
was used, which was produced via the reaction 16 0
(l36Xe, 7n) 145mS m . The energy and intensity of the
projectile were 7.6 A MeV and 3 x 1011 ions/s, respectively. The thickness of the target material (C0 2 gas)
was 0.91 mg/cm 2. The stripper foil was a 0.8 p,m-thick
Al foil , and the solenoid was operated under the condition that the beam optics was a point-to-parallel setting. The obtained intensity of the 145mSm high spinisomeric beam was 1- 2 x 105 pps with a kinematic energy of 5.53 ± O.l1A MeV. The main impurities were
due to contamination of the primary beam. The ratios of all the components in the charged particles atthe experimental focal point were 10% for the 145mSm
isomer, 10% for the 145Sm ground state, 50% for theother reaction products and 30% for both direct andindirect (scattered) contaminations of the 136Xe primary beam.
However, when the first experiment concerning thesecondary fusion reaction 13C 45m Sm, xn) 158- x Er
was performed, the purity of the high spin isomeric
beam became much worse due to a change in the primary beam condition. A careful analysis of the time
structure of neutron evaporation events revealed thefraction of each background component. Fig. 1 A- C indicate the variations of the '"'(-ray intensities in N d isotopes as a function of the time difference between the

e

*1

*2
*3
*4

*5

Department of Physics, Kyushu University
Nishinippon Institute of Technology
Institute of Modern Physics, China
Royal Institute of Technology, Sweden
Horia Hulubei National Institute of Physics and Nuclear Engineering, Romania

Time [l ch=O 3 125ns)~

1~',-~~--~~--~~--~~~

":~~

:~ ~

1·~JliiJ'~1~~:
::

10000

1~880

••• .•••,•.•• : ••. .•..••• • ...••.•.••...•.

1900

1920

1940

1960

..•.••••••

1980

2000

2020

2()4{)

2060.'"
Time Difference~ 1oooo.-~~--~~--~~--~~-,

l'M'~

100L-~~--~~--~~--~~~

1880

1900

1920

1940

1960

1980

2000

2020

2040

2060

Time Difference

100L-~~--~~~--~~--~~

1880

1900

1920

1940

1960

1980

2000

2020

2040

2060

Time Difference

Fig. 1. Time structures of the ,-ray intensities in Nd's.

RF signals and the neutron counter signals. A prominent ridge around channel number 2000 in the figures
was formed by the fusion products with direct contamination by 136Xe. From these spectra, the intensity ofeach component can be roughly estimated: 0.34% for
the 145mS m isomer, 0.34% for the 145Sm ground state,
1. 7% for the other reaction products, more than 85%
for direct 136Xe and more than 12% for indirect 136Xe.
Even under such a bad condition, four peaks corresponding to the transitions in the yrast band of 154Er
were identified.
Improvements were recently made in the gas target and primary beam handling system in order to reduce both the direct and indirect components of 136Xe.
To improve the gas target , the thickness of the apertures was made thinner; 14 mm-thick brass aperturesof the gas cell were replaced by 100 f.Lm-thick tantalum,
and the 10 mm-thick aluminum apertures of the outerchambers by 100 f.Lm-thick tantalum . This improvement reduced the indirect component. For improving
the primary beam handling system, a movable collimating slit was placed on the beam axis before the gas
target system in order to limit the emittance of the primary beam and to make the downstream beam morestable and more insensitive to the operating conditionof the accelerator. This improvement reduced the indirect component by preventing irradiation of the target
cell . It also made the beam spot more stable at F1 ,thus reducing the direct component.

41

RIKEN Accel. Prog. Rep. 35 (2002)

NaI(Tl) response for radioactive isotope beams
T. Suda, M. Chiba, T. Izumikawa,* R. Kanungo, T. Kato, A. Ozawa, T. Suzuki,* 1. Tanihata, T . Yamaguchi ,and T. Zheng[Total energy detector , nuclear reaction rate, response functions]A NaI(Tl) detector has been demonstrated to be agood total-energy detector for particle identification ina heavy-ion involved reaction. For instance, an energy
resolution of 0.7% (FWHM) was obtained for a 110AMeV 22Ne beam. In spite of its excellent energy resolution, the nuclear reaction contribution inside the totalenergy detector is not negligible, which introduces aserious background for particle identification. In thecase of ,the 110A-MeV 22Ne beam, about 7% of thetotal events is found to suffer nuclear reactions.
Since the nuclear reaction rate must depend on
the reaction cross section of the incident nucleus, theNaI(Tl) response to exotic nuclei, such as a halo nucleus , is expected to differ from the others. In orderto develop a total-energy detector , which has a goodenergy resolution and a smaller nuclear reaction contribution , it is important to understand the nuclear
reaction contribution inside a total-energy detector .
The NaI(Tl) response functions have been measured
for several radioactive isotopes, whose A/Z is close to
3 at the RIPS beam line using a 22Ne beam of IIGA
MeV. No degrader has been placed at FI, and thefragments have been transported to a NaI(Tl) detector
placed at F3. The size of the NaI(Tl) crystal is 3" ¢ x
6 cm, and the position of the fragments on the NaI(TI)
crystal have been monitored by two PPACs placed at
F3. Particle identification was performed based on thestandard Bp-~E- TOF method.
Figure 1 shows the response functions for isotopes of
Z = 3, 4, 5 and 6. In Table 1, the kinetic energy of thefragments , their range in the crystal and the nuclear
rate experimentally determined are shown. The widthof the full-energy peaks shown in Fig. 1 is about 1.2%
(FWHM), which is consistent with the width of the
momentum slit at F1.
The nuclear reaction rate of the fragments (11- 28%)
are larger compared with that for the primary 22Ne
beam (7%). Especially, it reaches nearly 30% for 11 Be,
which is known to be a halo nucleus.
How can we understand this? We correct the reaction rate due to a range difference by a simulation. A longer range for smaller Z fragments may
introduce a larger nuclear reaction rate. The simulation program is coded to estimate the nuclear reaction rate in the NaI(TI) crystal by using the reaction
cross section calculated by a phenomenological formula
proposed by Kox et al. 1) The energy dependence ofthe reaction cross section is taken into account above

102

10 2

10

10

102

10 2

10

10
102

10

10

102
10

10

o

1000 2000 3000 01000 2000 3000

NaI(TI) pulse height (ch)Fig. 1. Pulse height spectra of the NaI(TI) detector forradioactive isotope beams.
Table 1. Nuclear reaction rate in the NaI(Tl) detector withthe results of a simulation.
reaction rate

(%)
BLi
9Li
IlBe
12Be
14B
15B
17C
1BC

108
87
102
85
97
83
93
82

13.9
10.6
9.5
7.7
7.3
5.9
5.5
4.7

7

6.8

28 ± 0.6
25 ± 0.4
27 ± 0.5
17 ± 0.4
22 ± 0.8
13 ± 0.6
15 ± 0.6
11 ± 0.9

18
15
15
12
12
10
10
9

10 MeV/nucleon, where the formula is believed to workreasonably well.
The results of the simulation, presented together inthe table, account for the larger fraction of the nuclear reaction contri bu tion for lower Z , which comesfrom the longer range compared with 22Ne and larger
Z isotopes.
The simulation is found to give a good estimate of
the nuclear reaction rate for 22Ne, but underestimates
the rate for radioactive spices. It also underestimatesby a factor of almost two for a halo nucleus , 11 Be,
which may indicate that the reaction cross section of
11 Be is much larger than the Kox 's prediction.
References

Niiga ta University

421) S. Kox et al.: Phys. Rev. C 35, 1678 (1987).

RIKEN Accel. Prog. Rep. 35 (2002)

Absolute detection efficiency measurementof large plastic scintillators for neutrons at 100 MeV
S. Okada,*1 T . Hayashi,*1 K. Hirai,*1 H. Ikeda,*1 K. Itahashi,*1 M. Iwasaki *1 T. Katayama *1 M Miura *1· ..
*1 T . N akamura,* 1 M. Sato,*l T. Sugimoto,*l D. Tomono *1 "T. Yoneyama *1 T Nagae.
*2 ,A . M IyaJ1ma,
H . 0 uta, *2 H. C. Bhang,* 3 B. H. Kang,*3 J. H. Kim,*3 H. J. Lim,*3 T. Suzuki,*4".
,
H. Baba,*5 and N. Fukuda[Detection efficiency, Plastic scintillators]
In our resent nuclear experiments 1,2) at KEK-PS
many large plastic scintillation counters (1- 2 [m]) hav~
been used for detecting neutrons of 10- 200 MeV so as
to achieve both a large solid angle and a sufficient TO F
length. It is indispensable to measure the absolute detection efficiency for neutrons within 10% error. We
performed a test experiment (MSI08) to measure theneutron detection efficiency for our two large plastic
counters whose sizes are 100 x 20 x 5 [cm] (x (3 x 2)
counters) and 200 x 30 x 3 [cm] (x 2 counters), respectively. Since the cross section of the 7Li(p,no,1) 7Be(g.s.+0.43 MeV) reaction was measured with less than
a 6%3) error, the quasi-monoenergetic neutrons produced via this reaction were used as a neutron source.
no and n1 denote the neutrons produced from a reaction in which the residual nuclide 7Be is produced in
the ground and first excited states, respectively. Although these two states cannot be distinguished dueto the limit of the TOF resolution, they have sufficientability to be employed as a monoenergyetic neutron
source. The Ht beam from the RIPS beamline wasused as an incident proton beam at 100 MeV.
These neutron counters were located at a distanceof 5 meters from a 7Li production target which had
2.
'
0.2 g/cm thIckness. The configuration of these counters was arranged so as to be close in the real setup of
our KEK experiments; we piled and layered these neutron counters. The same charged-particle veto counters as that of our experiments were installed in frontof the neutron counters. The number of incident protons was counted by a small counter located in frontof the production target. This counter had a thickness of 1 mm. Thus, the neutrons produced by thereactions at this small counter was one of the main
neutron background sources. The protons scatteredat the production target were prevented from hitting
the neutron counters by using a sweep magnet (13 kG).
However, because a beam dump was located at a distance of about 4 meters from the neutron counters , theneutrons caused by dumped protons could be a background source. Therefore , we made empty target runs
for estimating of these backgrounds.
*1

D epartment of Physics, Tokyo Institute of Technology*2Institute of Particle and Nuclear Studies , High Energy Accelerator Research Organization (KEK)
Department of Physics, Seoul National University, Korea
Department of Physics, University of Tokyo
Department of Physics, Rikkyo University

*3
*4

*5

~200

Threshold: 5 MeVee

8
150
100

50

(J)

o~~iJ!r;III-~:052001191<E---7.

150

after subtracting
empty run

100
50
°1lJllO l..-.....a.d.l.I15.........J~20

35

40

TOF spectra (typical counter)

25

30

ns

Fig. l. TOF spectra for a typical counter at 5 MeVee
threshold.

The TOF spectrum for a typical counter at a 5 MeV
electron-equivalent threshold is shown in the top of
Fig. 1. The dashed line shows the spectrum foran empty run. We could clearly observe a sharp
peak coming from ground and the first excited state(g.s.+0.43 MeV). Because any accidental backgroundcan be evaluated from the yield at the faster components than this peak, this background was evaluatedto be less than 6%. The spectrum after subtracting
the empty run is shown at the bottom. By gating thispeak, the number of events from ground and the firstexcited state could be accurately counted.
Now a detailed analysis of the detection efficiency isin progress. Comparing the results of this analysis withthose of Monte-Carlo simulation codes for the neutron
detection efficiencies, CECIL 4) and SCINFUL,5) wewill certify the accuracy of the absolute detection efficiency and its dependencies on the threshold . Detecting neutrons by large plastic scintillators has recently
been a key point in the field of nuclear experiments.
The results of this experiment will offer data for thisstudy.
References
1) H. Outa et al.: KEK-PS E462 proposal (2000).
2) M. Iwasaki et al.: Nucl. lnstrum. Methods Phys. Res.
A 413 , 286 (2001).
3) T. N. Taddeucci et al.: Phys. Rev. C 41, 2548 (1990).
4) R. A. Cecil, B. D. Anderson, and R. Madey: Nucl. Instrum. Methods 161, 439 (1979).
5) J . K. Dickens: ORNL-6436, Oak Ridge National Laboratory (1988).

43

RIKEN Accel. Prog. Rep. 35 (2002)

Polarization transfer measurement for d-p elastic scattering
K. Sekiguchi, *1 H. Sakai,*1 A. Tamii ,* 1 K. Yako,*1 S. Sakoda,* 1 H. Kato ,*1 Y. Maeda,*1 M. Hatano,*1
T. Saito,*1 N. Uchigashima,*1 H. Okamura,*2 T. Uesaka,*2 K. Suda,*2 J. Nishikawa,*2 N. Sakamoto,
T. Ohnishi, Y. Satou, *3 T . Wakasa,*4 N. K. Nayestanaki,*5 and K. Ermisch*5[ Kiz(B)

N~CLEAR REACTIONS , IH(d~p)2H, Ed = 270 MeV measured: K~' (B), K~~(B) , Ki~(B) 'l

We have reported precise measurements of cross sections and all deuteron analyzing powers at Ed = 140,
200, and 270 MeV, and compared the obtained datawith the Faddeev calculations with and without theTucson-Melbourne (TM) 3NF model. l ,2) For the crosssection and the vector analyzing power (A~), including
the 3NF model brings a good agreement of the data,
while for the tensor analyzing power the agreement isdeteriorated when the 3NF model is included. In order to further assess the 3NF effects, we extended themeasurement to new observables , namely polarizationtransfer measurement for the l + p ~ p + d elastic
scattering.
The experiment was performed at the RIKEN Accelerator Research Facility using tensor and vector palarized deuteron beams of 270 MeV. A liquid hydrogen(19.8 mg/cm 2) or CH 2 (93.4 mg/cm 2) target was bombarded and scattered protons were momentum analyzed by the magnetic spectrograph SMART. The
polarization of the scattered protons was measured
with the focal-plane polarimeter DPOL. The measured
observables were the deuteron to proton polarizationtransfer coefficients (K~', Ki~ , K~~, and Ki~) in the
angular range of Be .Ill . = 90° -180°. This measurement
also yielded an induced polarization (pY') of the outgoing protons. The relation between the polarizations
and the observables is expressed aswhere x, y , and z are the coordinates of the incident
deuterons; x' , y', and z' are those of the emitted protons; and (~) denotes the cross section with unpolarized beams.
Figure 1 shows the experimental results with open
squares. The errors are only statistical. The open
squares are our previous data in a test measurement. I)
The two measurement data provide a good agreement,
except for Ki~ - K~~ at Be .Ill . = 150° . The dark andlight shaded bands in Fig. 1 are the calculated results
*1
*2
*3
*4

*5

44

School of Science, University of Tokyo
Department of Physics, Saitama University
Center for Nuclear Study, University of Tokyo
Research Center for Nuclear Physics , Osaka Un iversity
KVI , The Netherlands

9, ..., [deg]9" .. , [deg]Fig. 1. K~~ - Kt~, K t' , K~:, and P y' for d-p elastic scattering at E~ab = 270 MeV. The dark and light shaded
bands in Fig. 1 are the calculated results with andwithout TM 3NF, respectively. The CDBonn, AVI8,
Nijmegen I,ll and 93 potentials are considered as N N
forces . The Coulomb force is not included . The horizontal axis (e c . m .) is defined as the angle between theincident and outgoing deuterons in the center-of-masssystem.

with and without TM 3NF by the Bochum-Cracow
group,1 ,3) respectively. The CDBonn, AVI8, Nijmegen
I,II and 93 4) potentials are taken as two nucleon (N N)
interactions. Note that the Coulomb interaction is notincluded. The horizontal axis (B e .Ill .) is defined as theangle between the incident and outgoing deuterons in
the center-of-mass system. For Ki~ - K~~, the data
support the 3N force calculations, while for the otherobservables (K( , Ki~, pY') large differences between
the data and the N N force predictions are not reproduced by including the 3NF model.
The results of the comparison for the polarizationtransfer coefficients reveal that the TM 3NF model has
deficiencies in its spin parts and that these observables
are useful to clarify the spin dependence of 3NF effects.
References
1) H. Sakai , K. Sekiguchi , H. Witala et al.: Phys . Rev.
Lett . 84, 5288 (2000).
2) K. Sekiguchi et al.: RIKEN Accel. Prog. Rep. 34 , 50
(2001); K. Sekiguchi et al.: Nucl. Phys. A 684 , 574c
(2001).
3) H. W itala et al.: Phys. Rev. C 6 3 , 024007 (200 1).
4) R. Machleidt: Phys. Rev. C 63, 024001 (2001); R. B.
Wiringa et al. : Phys. Rev. C 51 , 38 (1995); V. G . J.
Stoks et al.: Phys. Rev. C 4 9 , 2950 (1994).

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of the analyzing powers for the dd ---+ 3Hp anddd ---+ 3Hen reactions at 270 MeV
T. Saito,*l v. P. Ladygin,*2 T. Uesaka,*3 H. Sakai,*l H . Okamura,*3 A. I. Malakhov,*2 s. G. Reznikov,*2
A. Y. Isupov,*2 N. B. Ladygina,*2 N. Sakamoto, T. Ohnishi , A. Tamii,*l K. Sekiguchi,* l K. Yako ,* lS. Sakoda,*l K. Suda,*3 H. Kato,d Y. Maeda,* l M. Hatano,*l J. Nishikawa,*3 N. Uchigashima,*lH. Kumasaka,*3 R. Suzuki,*3 and Y. Satou,*4[ad ~ 3Hp eHen) reaction, Ed = 270 MeV, Analyzing powers]
The structure of 3H and 3He nuclei in the high internal momentum region has not been clear!;' understood. The tensor analyzing powers for the dd ~ 3Hp
and~ 3Hen reactions are appropriate probes tostudy the ratio of the S- and D-state wave functionsof 3HeHe) nuclei in the high-momentum region. Calculations with the One Nucleon Exchange (ONE) approximation 1 ) show that the angular distributions of
the tensor analyzing powers for these reactions are
sensitive to the structure of the 3HeHe) if 3HeHe)
is emitted in the forward hemisphere in the center-ofmass frame. On the other hand, they depend mainlyon the structure of the deuteron in the case of backward emission. Measurements of these observables
with a 270 MeV deuteron beam at BerneH or 3He) :s;
90° provide information about the 3HeHe) spin structure up to a relative momentum of a dN pair of -....
600 MeV Ie. Since 3H and 3He are mirror nuclei of eachother , the nature of charge symmetry breaking can also
be studied by measuring the analyzing powers for boththe
~ 3Hp and dd ~ 3Hen reactions.
We measured the t ensor and vector analyzing pow....
3ers (Ayy , A xx , A xz, and Ay) for the dd ~ Hp anddd ~ 3Hen reactions at Ed = 270 MeV over almost
the full angular range. A CD 2 target was bombarded
by polarized deuteron beams. Scattered particles weremomentum-analyzed by the SMART spectrograph. In
the case of the 3Hen channel , we detected 3He. In thecase of the 3Hp channel, 3H (protons) were detected if
3H were emitted in the forward (backward) angles in
the center-of-mass frame. We also measured the energy spectra with a carbon target in order to subtract
the contributions from carbon nuclei in the CD 2 target.
Beam polarizations were monitored with the beam-line
polarimeters based on the dp elastic scattering.
The preliminary results of the analyzing powers arepresented in Fig. 1. The results of the 3Hp and 3Hen
channels are plotted by filled and open circles, respectively. The solid , dot-dashed, and dashed lines are theresults of ONE calculations with different 3He wave
functions from Refs. 2, 3, and 4, respectively. The
Paris deuteron wave function was used in these cal-

ad

ad

*1
*2

*3
*4

Department of Physics , University of Tokyo
LHE-JINR, Russia
Department of Physics, Saitama University
Center for Nuclear St udy, University of Tokyo

0.50
0.25

P~~i:~T~

0.00... ... . . 9y+ ...~·....·' ... ""'oi.''~~C)C)~0.25.........

Ay

0.50 ft-~--+---~-t----""""'---I-1.0
1.0 tI-~--+-----t----""""'------j
0.5
0.0
-0.5
-1.0

-1.0 Il....-_ _ _-"--_ _ _' - - -_ _- - - '_ _ _ _-"

o

50
100
150
Scattering angle 01 "H ("He) in the c.m. frame [deg]Fig. 1. Preliminary results of the analyzing powers for thedd ---- 3Hp a nd dd ---- 3Hen reactions at Ed = 270 MeV.
The filled and open circles are for the 3Hp and 3Hen
channels, respectively. Explanations for the curves are
given in the text.

culations. The general features of the angular distributions of the analyzing powers were reproduced by
ONE calculations at the backward emission angles of
3H, while great discrepancies were found between the
ONE predictions and the experimental results at forward angles. These results indicate that there might
be some problems in the wave function of the threebody system used in the ONE' calculations. Since theresults of the 3Hp and 3Hen channels are in agreement ,the effects of charge symmetry breaking have not been
observed within the experimental uncertainty.
References
1) V. P. Ladygin , N. B. Ladygina, H. Sakai, and T. Uesaka:Part. Nucl. Lett. 3(100)-2000 , 74 (2000).
2) J. M. Laget , J. F. Lecolley, and F. Lefebvres: Nucl.
Phys. A 370, 479 (1981).
3) F . D . Santos, A. M. Eiro , and A. Barosso: Phys. Rev.
C 19, 238 (1979).
4) R. Schiavilla, V. R. Pandharipande, and R. B. Wiringa:
Nucl. Phys . A 449, 219 (1986).

45

RIKEN Accel. Prog. Rep . 35 (2002)

Measurement of the tensor analyzing power (T20) in the dd ~ 3Hp
and dd ~ 3Hen reactions at 0°
V. P . Ladygin,*l T. Uesaka,*l T . Saito,*2 M. Hatano,*2 A. Yu. Isupov,*3 H . Kato,*2 H. Kumasaka,*lN. B. Ladygina,*3 Y. Maeda,*2 A. 1. Malakhov,*3 J . Nishikawa,*l T. Ohnishi , H. Okamura,*lS. G. Reznikov ,*3 H. Sakai,*2 N. Sakamoto, S. Sakoda,*2 Y. Satou,*4 K . Sekiguchi,*2
K. Suda,*l R. Suzuki,*l A . Tamii,*2 N. Uchigashima,*2 and K . Yako*2[Three-nucleon Structure, polarized deuteron]
For the last decade, the tensor analyzing power (T20)
for one-nucleon transfer reactions, like dp and d 3He
backward elastic scattering, or d 3He - t p4He, at intermediate energies in collinear geometry has been intensively studied as an important source of information
about the spin structure of light nuclei at short distances.
The tensor analyzing power (T20 ) in the dd - t 3Hp
and dd - t 3Hen reactions at 140, 200 and 270 MeV ofthe deuteron kinetic energy and in collinear geometry
has been measured at RARF using the SMART spectrograph. 1) The beam polarization has been measured
with a polarimeter based on dp elastic scattering. It
was continuously monitored during a run. The momentum of the secondary particles was reconstructedusing the information from the drift chambers placedat the focal plane of the SMART spectrograph. I) The
identification of the p, d, 3H and 3He was done using the pulse-height and timing information from threeplastic scintillators. The CD 2 - C subtraction wasmade for each setting of the spectrograph to obtainthe contribution from deuterium.
The obtained data are shown in Fig. 1 versus theinitial deuteron momentum. The open triangles andsquares are the T 20 data in the dd - t 3Hp reaction
with 3H emission at 0° and 180° in the c.m., respectively, while the solid circles represent the data in the
dd - t 3Hen channel at 0°. The solid and dashed curves
represent the calculations 2) performed within a onenucleon exchange (ONE) approximation for the forward and backward kinematics, respectively. In thismodel the tensor analyzing power (T20) in collinear
geometry has the following form:(1)
where r is the D / S- waves ratio in 3HeHe) or in
the deuteron at the corresponding internal momentum
for t he forward and backward kinematics, respectively.
Equation (1) is also valid for T 20 in d 3He and dp backward elastic scatterings and in the d 3He - t p4He reaction. Therefore, the dependence of T 20 for these reac*1
*2

*3
*4

46

Saitama University
University of Tokyo
LHE-JINR, Russia
Center for Nuclear Study, University of Tokyo

0.5

••
DO

•
o

-0.5

-1

- 1.5

L--_--'----_o0.5-----'-_ _- ' - - _ - L -_ - - - L _ - - - - '

1.0

1.5

2.0

2 .5

3.0

Pd' GeV / c
Fig. 1. T20(O O) in the dd -7 3Hp and dd - 7 3Hen reaction
as a function of Pd. The solid and broken lines represent
the ONE calculations 2 ) with the 3He wave function of
Ref. 3.

tions versus the internal momentum must be the same
if ONE is valid.
One can see that the data obtained for both channels, dd - t 3He(00)n (solid circles) and dd - t 3H(00)p(open triangles), within the achieved experimental accuracy are in good agreement. The sign of T 20 in the
dd - t 3 HpeHen) reaction is opposite when 3HeHe) is
emitted in the forward or backward direction in thecenter-of-mass system. The sign of the T 20 data at 0°in the center-of-mass system is positive and agrees withthat obtained in the d 3He - t 3Hed reaction. 3) For the
backward kinematics , the sign of the T 20 data is negative in accordance with the signs of T 20 in dp backward
elastic scattering4) and in the d 3He - t p4He reaction. 5 )This fact is attributed to the sensitivity of the data to
the D / S- ratio in the 3H (3He) and deuteron.
Although the global feature that T 20 is negative andits magnitude increases with the projectile momentum
is consistent with the prediction of the ONE approximation, the absolute magnitude of T 20 deviates dra-

matically from the calculations at the backward angles.
In addition, the magnitudes are even different among
the dp backward elastic scattering, the d 3He -----7 p4He,
and the dd -----7 3H(1800)p reactions. Therefore, one
can conclude that a mechanism beyond ONE is necessary for a better description of the data, and thatthe mechanism gives different effects depending on thereactions. One possible theoretical approach to the
problem is to use 3N Faddeev amplitudes instead of
the ONE amplitudes. Measurements of additional polarization observables will also help us to understandthe mechanism more clearly.
References
1) T. Ichihara et al.: Nucl. Phys. A 569, 287c (1994).
2) V. P. Ladygin, N. B. Ladygina, H. Sakai, and T. Uesaka:Part. Nucl. Lett. 3(100), 74 (2000).
3) M. Tanifuji et al.: Phys. Rev. C 61, 024602 (1999).
4) V. Punjabi et al.: Phys. Lett. B 350, 178 (1995).
5) T. Uesaka et al.: Phys. Lett. B 467, 199 (1999); FewBody Systems Suppl. 12, 497 (2000).

47RIKEN Accel. Prog. Rep . 35 (2002)

Measurement of single and double spin-flip probabilities In
inelastic deuteron scattering on 12c at 270 MeV t
Y . Satou,*l s. Ishida,*2 H. Sakai,*1 ,*3 H . Okamura,*4 H. Otsu,*5 N. Sakamoto, T. Uesaka,*4 T. Wakasa,*6
T. Ohnishi, K. Sekiguchi,*3 K. Yako,*3 T. Ichihara, T. Niizeki ,*7 K. S. Itoh,*5 and N. Nishimori*8[(d, d') reaction, spin-flip probability]
A polarization transfer measurement in inelastic
deuteron scattering is one of the essential probes ofisoscalar spin excitations. The reaction is selective ofisoscalar transitions, while the spin 8 = 1 nature of thedeuteron allows spin transfer to the target. The measurement of deuteron SFPs should provide a means
to disentangle between spin and non-spin excitations .
The single and double SFPs, 8 1 and 8 2, are expressedin terms of polarization observables by the following
relations :
1

I

I

,

I

9(4 - Py y - Ayy - 2K~/ ),
1

I

I

I

(1)
I

,

18 (4 + 2PY y + 2Ayy - 9K~ + K~/ ).

(2)

The quant ities A, P and K refer to the analyzing
power, polarizing power and polarization transfer coefficient, one (two) index stands for the vector (tensor)
polarization, and the lower (upper) one for the incident(outgoing) beam. The determination of 8 1 and 8 2 thus
requires vector and tensor polarized beams and vector
and tensor polarimeters.
We have succeeded to measure the single and double
spin-flip probabilities through a direct observation ofpolarization transfer, thus by measuring all of the coefficients in Eqs. (1) and (2) in inelastic deuteron scattering on 12C at Ed = 270 MeV. The experiment was

*1

*2

*3
*4

*5

*6
*7

*8

48

Condensed from the article in Phys. Lett. B 521 , 153 (2001)
Center for Nuclear Study, University of Tokyo
Soei Corporation
Department of Physics , University of Tokyo
D epartment of Physics, Saitama University
Department of Physics, Tohoku University
Research Center for Nuclear Physics, Osaka University
Tokyo K asei Un iversity
Japan Atomic Energy Research Instituteperformed using vector and tensor polarized deuteronbeams from the RIKEN Ring Cyclotron , the magnetic
spectrometer SMART and a focal-plane deuteron polarimeter, DPOL. DPOL utilized d + C elastic scatterin~ for vector polarization measurements, and the1H( d, 2p) charge exchange reaction for tensor polarization measurements. It allowed all of the polarization
components of the scattered deuterons to be measured
simultaneously over a wide excitation energy range(4 and 24 MeV). The observed 8 1 value is large fort he spin-flip 1+ (12.71 MeV) state, while it is close tozero for other non-spin-flip states, such as the first 2+(4.44MeV) state. The 8 2 values are consistent withzero for all of the measured excitation energy range,
and no clear indication of the /).8 = 2 states has beenobtained from the present measurement . The overall
trends of the SFP angular distributions for the 1+ and2+ states are well described by the microscopic DWIA
calculations. The demonstrated feasibility of measuring the deuteron SFPs as well as the capability of the
DWIA theory to reproduce the data will add a newalternative probe of nuclear structure. Further experiments are planned in a search for the /).8 = 1 and 2transitions in a higher excitation energy region in 12C
and in other nuclei.

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of Doppler-shift attenuated , raysfrom the 180(2t) state
N. Imai ,* 1 N. Aoi,*1 H. Sakurai,*1 K. Demichi,*2 H. Kawasaki,*2 H. Baba,*2 Zs. Dombradi *3 Z. Elekes *3
N. Fukuda, Zs. Fiilop,*3 A. Gelberg,*4 T. Gomi,*2 H. Hasegawa,*2 H. Iwasaki *5 E. Kaneko' *2 S. Kann; *2
T. Kishida, Y. Kondo,*6 T . Kubo, S. Michimasa,*5 T. Minemura, M. Mi~ra,*6 T. Mot~bayashi *2 'T . Nakamura,*6 M. Notani,*3 T. Ohnishi,*1 H. J . Ong,*1 A. Saito,*2 S. Shimoura,*5 T. Sugimot~,*6
S. Takeuchi,*2 K. Yoneda, H. Watanabe, and M. Ishihara[NUCLEAR REACTIONS: 197 Aue 8 0 , 18 0*)197 Au E = 48.2 MeV lu; DSA]

0is.

The B(E2;---7 2i) values in even-even neutronrich nuclei have been successfully measured at intermediated energies by using the Coulomb excitation
method. 1,2) However, this technique is not suitable
for a nucleus with Z < 8, since the nuclear excitation competes with the Coulomb excitation for low-Z
projectiles. As an alternative, we propose a mean-life
measurement of the 2t ---7transition using the
Doppler-shift attenuation method at intermediate energy. Here, we report on the first attempt to apply thismethod to fast (13 ~ 0.3) projectiles.
In this experiment, we used a thick target and the
projectile velocity was degraded in the target. Accordingly, the Doppler shifted ')'-ray energy was spread overa certain region. The energy of the')' ray emitted inside the target was distributed continuously, while thatemitted outside the target was constant since the projectile did not change its velocity any more. The latter component became larger when the mean-life was
longer. Therefore, when we properly chose the target
thickness and the projectile energy so that the time
for the projectile to pass through the target would becomparable with the mean-life of its excited state, themean-life can be determined from the shape of the energy spectrum of 500 ')'-ray events with ± 10% uncertainty.
As a test , we applied this method to the 18 0(2+)
state, whose mean-life is precisely known to be 2.79 ±0.07 pS.3) The experiment was performed at RIKEN.
The energy of the 18 0 primary beam of 100 MeV lu
was degraded by a 9Be target of 463 mg/cm 2 and analuminum degrader of 1358 mg/cm 2 . Figure 1 shows aschematic view of the experimental setup. At the thefinal focal plane of RIPS ,4) an energy of 48 .2 MeV lu
was obtained. The 180 beam hit a 580 mg/cm 2 thick
197 Au target. In this case, the time needed to passthrough the target was 3.5 ps. The de-excitation,), raysfrom the inelastically excited 18 0 nuclei were detectedby four clover Ge detectors (Clovers). Each Clover was

O:'s.

*1

*2

*3

*4
*5
*6

University of Tokyo
Rikkyo University
ATOMKI , Hungary
University of Koeln, Germany
Center for Nuclear Study, University of Tokyo
Tokyo Institute of Technology

4 Clover detectors

Fig. 1. The layout of the detection system. See text for
details.

located 30 cm upstream from the target at 150 degrees
with respect to the beam direction.
The observed Doppler-shifted , -ray energy was
spread due to the finite angular acceptance and thechange in the velocity. The spread due to the angular acceptance was about 25 keV, while the energy
spread by the velocity change was 100 keY. We would
thus distinguish between a ')' ray from outside the target and that from inside. The scattering angle wasmeasured by three parallel plate avalanche counters,
two of which were located upstream and the third one
downstream of the target. Particle identification of thescattered particle was carried out with a silicon telescope using the t::.E-E method. A silicon telescope wasplaced 30 cm downstream from the target, covering anangular acceptance of ± 9.6 degrees . It consisted offive layers of silicon detectors with thicknesses of 0.5,
1.0, 0.5 , 1.0, and 0.5 mm, respectively. Each layer wascomposed of four silicon detectors. In order to preventthe background ')' rays from the silicon detectors, we
put a 5 cm thick lead shield between the Clovers andthe silicon telescope (See Fig. 1). Data analysis is inprogress.
References
1) T. Motobayashi et al.: Phys. Lett. B 346, 9 (1995).
2) T. Glasmacher: Ann. Rev. Nucl. Part. Sci. 48, 1 (1998).
3) G. C. Ball et al.: Nucl. Phys. A 377, 268 (1982).
4) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).

49

RIKEN Accel. Prog. Rep . 35 (2002)

Projectile excitation In 160+208Pb,natc at E( 16 0)
Preliminary resultslOOA MeV:

S. Kumar,* V. M. Datar,* D. R. Chakrabarty,* E. T. Mirgule,* R. Kanungo, K. Kusaka, K. Morimoto,A. Ozawa, 1. Tanihata, F. Tokanai, and K. Yoshida[NUCLEAR REACTION 160 +208Pb,natc at Ee 6 0) = 100A MeV; Coulomb excitation]
The giant resonance (GR) strength function in exotic nuclei is a topic of current interest . This can bemeasured from the Coulomb excitation (CEX) of highenergy exotic nuclei by a high-Z target. With a motivation to conduct such studies with radioactive ion
beams from the RIPS facility, a test run was undertaken using a stable 16 0 beam. The results of a partial
analysis of the data are presented in this report.
Targets of 208Pb (351 mg/cm 2) and natc(180 mg/cm 2) were bombarded with an 16 0 beam
(1600 MeV, ---10 5 pps) in the RIPS beam line. The
projectile-like residues (PR) were detected in two detector stacks (2° to go on either side of the beam) consisting of a pair of X and Y Si-strip detectors (450 /-Lm,
10 strips), two Si-PIN diodes (450/-Lm) , three Si(Li)s(2 mm) and two plastics (12 and 8 mm). The lightparticles (n, p and Q) were detected in t hree multilayer plastic walls at distances of between 3 and 5 mfrom the target and covering --- 2° to 20°. The layers
consisted of plastic bars of cross-section 6 cm x 6 cm,
having PMTs at both ends. Thin plastic layers (5 to
10 mm) were kept in front of two walls. The front layer
was used for identifying the light particles whose energy was derived from the time of flight. An array of
125 BaF 2 detectors (E75%) was used to detect '"'(
rays from the excited PRs. The target and detectors
were kept in air. The beam was monitored by a PPAC ,which also generated a fast reference time output.
In the present analysis, one PR-stack, one plastic
wall and only decay by light charged particles (LCP),
p and Q , are considered. The'"'( decay of the PR is ignored. The analysis included only those events whichcorrespond to the detection of one PR in the stack detector and the corresponding LCP in those parts of
the wall shadowed by the stack detectors and in the
shadow-free central zone. The energies of the LCPs
and PRs were corrected for the energy loss in air andthe stack material. From the measured energy and the
direction of the PR and the associated LCP, the excitat ion energy (Ex) of 16 0 was calculated. The contribut ion from air in the beam path , measured with a blanktarget, was significant (Fig. 1) and subtracted. A comparison of the subtracted Pb and C spectra, normalized to the number of target atoms, showed that thenuclear excitation (NEX) is significant at this beamenergy. These normalized C spectra are scaled up by

1600
,

1200

ttt

t
t

a+

0

800
~
;:)

400

n
3000

t

2000

't

0

cP°ooo

-••

10

20

t:P
0

a ir

0

o~! ...

12

C

.

p+

C
air

0

1000
0

N

0 ° 0 0 ••

a+
tt

15

Pb

~~.

0
U

p+

0'

air

0

o~.

00

C

Pb

• ooOr;oo:-.

[fJ
~

12

~ooo:·

Ooooen.. .........
30

0

10

15

N

C
air

••_.
30

20

40

Exc ita ti o n e n e r gy (M e V)

Fig. 1. Ex-spectra in 16 0 in two decay channels for 208Pb
and C targets. The contribution from air is also shown.

a+
•
[fJ

800

12

p+

C

Pb

o C (scaled)

•
o

15

N

Pb
C ( sca le d)

~

~
;:)

o
u
400

f"V

Nuclear Physics Division , Bhabha Atomic Research Centre ,
India

50

40

Fig. 2. Ex-spectra in 16 0 after subtracting air contribut ion. The C spectra are scaled for estimating the nuclear contribution in the Pb spectra.

a factor of 1.76 (ratio of the interaction radii in thetwo systems) and are compared with the Pb spectrain Fig. 2. This shows that the CEX exceeds NEX for
Ex below --- 12 MeV. Thus, the extraction of t he GR
strength can be made from CEX at this beam energy
if a significant fraction of the sum-rule strength lies
well below this Ex. This may be true for very exotic nuclei. The neglect of PR '"'( -rays in the analysis
implies that the actual Ex spectra are somewhat different from those shown. The cross section at lower
Ex will be depleted with a corresponding increase at
higher Ex. However , the conclusions regarding the relative importance of CEX and NEX is not expected tochange.

RIKEN Accel. Prog. Rep. 35 (2002)

Indirect measurement of the solar-neutrino
production reaction 7Be(p,,)8Bt
T. Motobayashi*[Solar neutrino, 8 I7 -factor , Coulomb dissociation]
Intermediate-energy Coulomb dissociation and lowenergy proton transfer (ANC determination) have been
applied to determining the astrophysical 8 factor of the7Be(p,,)8B reaction, which is of crucial importance forhigh-energy solar-neutrino production. The results are
generally in good agreement with a recent evaluationfrom direct capture measurements, as shown in Fig. 1,
where the 817(0) values from Coulomb dissociation,
ANC and direct-capture measurements are plotted together with the latest recommendation. I) This gives
a support to the recommended reaction rate of the7Be(p,,)8B reaction used in solar models. For a moreaccurate determination , however, further studies arenecessary to evaluate possible corrections due to the
mixture of E2 and nuclear components and higher order processes for the Coulomb dissociation method. A
more detailed confirmation of the AN C method should
also be made by careful investigations of multi-stepprocesses, the choice of the optical potentials, and soon. Finally, it should be pointed out that either direct or Coulomb dissociation measurements have notreached the Gamow energy of solar burning. Extrapolation is necessary to estimate 817 at lower energies
with a theoretical energy dependence. Efforts to obtain lower energy cross sections are desirable to reduce
the ambiguity of the 7Be(p,,)8B reaction rate.

+Coulomb dissociation
+ANC

50

j

':D 40I>-+ direct capture

Q)

~ 30
o
""-'"

~

(IJ

20

l_____ _r:-------!t ______________ _______~ : -t ~:::---~: J---:~:: --:--f :--Jll---- :

10

1960

1970

1980

1990

2000

YEAR
Fig. 1. Values of S17(0) extracted by the Coulomb dissociation method (solid circles) and the ANC method (solid
squares). Those obtained by direct capture measurements are also shown by the solid diamonds. The latest
recommendation, S17{O) = 19 ~~ eV-b,l) is indicated by
the dashed and dot-dashed lines.

References
1) E. G. Adelberger et al.: Rev. Mod. Phys. 70, 1265
(1998).

Condensed from the article in Nucl. Phys. A 693,258 (2001)
Department of Physics, Rikkyo University

51

RIKEN Accel. Prog. Rep . 35 (2002)

Determination of the astrophysical S factor of the 8B(p, ,)9C
capture reaction from the 8B( d, n)9C reaction
D . Beaumel,*1 T. Kubo, T. Teranishi ,*2 H. Sakurai,*3 S. Fortier,*1 A. Mengoni,*4 N. Aoi,*3 N. Fukuda,
M. Hirai ,*5 N. Imai ,*3 H. Iwasaki ,*2 H. Kumagai , H. Laurent, *1 S. M. Lukyanov,*6 J. M. Maison,*1
T. Motobayashi,*7 T . Nakamura,*8 H. Ohnuma,*9 S. Pita,*1 K. Yoneda, and M. Ishihara[Transfer reaction , Nucleosynthesis]
Radiative capture reactions playa crucial role in astrophysics , since they are involved in most basic processes, such as hydrogen burning. In the case of thecapture of charged particles, a direct measurement of
the cross sections is especially difficult due to the low
incident energies at astrophysical sites (compared to
the Coulomb barrier) . Indirect methods, for which thecapture cross section is deduced from another reaction, provide alternative approaches, particularly appropriate when radioactive nuclei are involved. Transfer reactions are a long-standing tool in this respect .
The determination of spectroscopic factors allows one
to deduce the direct radiative cross section by using
two-body potential models. When the reaction is peripheral , recent studies 1) have shown that, instead ofspectroscopic factors , the relevant quantities to be extracted from transfer reactions are asymptotic normalization coefficients (ANC) , which define the asymptotic
part of the nuclear overlap function between the initialand final nuclei. These coefficients are determined in asimilar way as spectroscopic factors (i. e. by normalizing a calculated DWBA cross section to the data), but
are much less dependent on the DWBA parameters.
In our study, we determined the ANC's corresponding to the overlap (9CI 8B , p) via the 8B( d , n)9C transfer cross section. From these ANC's the cross section(or equivalently, the S factor) of the capture reaction,
8B(p, ,)9C, can be deduced. Because the 8B nucleus
has a short half-life (0.77 s), this reaction cannot play

*1 Institut de Physique Nucleaire, France
*2
*3
*4
*5

*6
*7

*8
*9

52

Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Ente per Ie Nuove Tecnologie, l'Energia el'Ambiente , Italy
National Institute of Radiological Science
Joint Institute for Nuclear Research, Russia
Rikkyo University
Tokyo Institute of Technology
Chiba Institute of Technology

a role in stars like the sun, but it may become 2) alink between light nuclei of the proton-proton chain
and CNO nuclei (the hot p-p chain) in a very hot anddense medium. Due to the short half-life, a direct measurement of 8B(p, ,)9C is impossible at the moment.
At the RIKEN facility, we have measured the crosssection of the 8B(d, n)9C reaction at 14.4 MeV lu ininverse kinematics. A radioactive 8B beam was produced using the RIPS device. The 8B yield was roughly
10 4 pps. The 9C ejectiles were detected in coincidencewith the neutrons , allowing us to separate good eventsfrom the background, despite a very low count rate.
The deduced value for the S factor of the 8B(p, , )9C
reaction is
S18 = 45 ± 13 eV.b. 3)This result is roughly a factor of two lower thanthe calculated value already reported,4) where a microscopic cluster model was used. It is in stronger disagreement (factor 4) with the calculation of anotherreference. 2 )References
1) A. M. Mukhamedzhanov et al.: Phys. Rev C 51, 3472
(1995).
2) M. Wiescher et al.: Astrophys. J . 343, 352 (1989).
3) D. Beaumel et al.: Phys. Lett. B 514, 226 (2001).
4) P. Descouvemont: Nucl. Phys. A 646 , 26 (1999).

RIKEN Accel. Prog. Rep. 35 (2002)

Inelastic scattering of 12Be with 4He
Y. u. Matsuyama,*1 T. Motobayashi,* 1 s. Shimoura,*2 T. Minemura, A. Saito,* 1 H. Baba,* 1 H. Akiyoshi,
N. Aoi ,*3 Y. Ando ,* 1 T. Gomi,*1 Y. Higurashi,*1 K. Ieki ,*1 N. Imai ,*3 N. Iwasa,*4 H. Iwasaki,*2 S. Kanno,*1
S. Kubono,*2 M. Kunibu,* 1 S. Michimasa,*2 H. Murakami,* 1 T. Nakamura,*5 H. Sakurai,*3 M. Serata,* 1
E. Takeshita,*1 S. Takeuchi,*1 T. Teranishi,*2 K. Ue,*2 K. Yamada,* 1 and Y. Yanagisawa[NUCLEAR REACTION: 4He(12Be, 12Be*), Inelastic Scattering, Liquid helium]
We studied inelastic a + 12Be scattering by measuring the ,-decay of 12Be in its exited states. This was
the first experiment with RI beams using a liquid-He
target developed earlier. 1)
The experiment was carried out with RIPS. A primary 16 0 beam of 135 MeV/nucleon bombarded a 9Be
production target with 1480 mg/cm 2 thickness to obtain a radioactive beam of 12Be. The 12Be nuclei inthe beam were separated event by event from contaminates using time-of-flight (TOF) information between two plastic 0.5 mm thick scintillators separated
by 5.3 m from each other. The energy of the beam wasapproximately 60 MeV /nucleon, the purity of the 12Be
beam was more than 90% and the intensity was around3 x 10 4 S-1 .
A liquid-He target of 250 mg/cm 2 was placed at theforcal plane of RIPS. Liquid helium was confinedwithin a cell with a Havor foil window of 24 mm diameter. The direction and position of a beam particle
at the target were measured by two sets of parallel
plate avalanche counters (PPAC's) installed upstream
from the target.
Outgoing particles were detected and identified by aplastic scintillator array hodoscope located 4 m downstream from the target. The array consisted of threelayers (.D.E, E1, and E2) of 5 mm, 60 mm, and 60 mm
thickness, respectively. The energies and scattered angles of the particles were determined by the TOF's andhit positions in the hodoscope, respectively. Each particle was identified by using the TOF-.D.E and TOF-E
methods.
Sixty-eight NaI(Tl) scintillators surrounded the target to detect , rays emitted from excited 12Be nuclei.
Each scintillator crystal was of rectangular shape witha size of 6 x 6 x 12 cm 3 coupled with a 5.1 cm ¢ photomultiplier tube. The segmentation of the array allowed
us to correct for Doppler shifts from moving reaction
products.
Figure 1 shows the ,-ray energy spectrum associatedwith 12Be identified in the hodoscope. It was obtained
as a sum of each Doppler-corrected spectrum of all the
NaI(Tl) scintillators. As one can see in Fig. 1, twofull-energy peaks were observed. The energies were
*1
*2

*3
*4

*5

Department of Physics, Rikkyo University
Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Department of Physics, Tohoku University
Department of Physics, Tokyo Institute of Technology;;:Q.J

10000
5000

~
0
............

lfl

-'

~
;:l
0

u

1000
500
100
50
234

0

E")' (MeV)

Fig. 1. Doppler-corrected ,-ray stectrum measured in coincidence with 12Be.

determined to be 2.10 MeV and 2.68 MeV. The firstpeak is assigned to the--+transition, whereas
the second one might correspond to the 1- --+transition, which has been observed in the Coulomb
excitation experiment.2)
Figure 2 shows the experimental differential crossstate andsection for inelastic scattering exciting thethe 1- state in 12Be. A clear diference is seen between
theand 1- distributions suggesting the usefulnessof a -inelastic scattering for nuclear-structure studies.
Data analyses are now in progress.

2t O:'s.

O:'s.

2t

2t

I

103 ~ooo 0

I

I

0

r--..

h
lfl

............

..0

5
c:

'D

............

10 2

...,

,...

10 1 ,...

b

0 ...,

0'D

0

10 0 ,...
0

2+ (2.10 MeV)
- (2.68 MeV)
...,
I

2
Blab

I

I

4

6

8

(deg)

Fig. 2. Observed differential cross section for inelastic scattering the exciting 2i state and the 1- state on 12Be.

References
1) H. Akiyoshi et al.: RIKEN Accel. Prog. Rep. 34, 193(2001) .
2) H. Iwasaki et al.: Phys. Lett. B 491, 8 (2000).

53RIKEN Accel. Prog. Rep. 35 (2002)

Isomeric 0+ state in 12Be
S. Shimoura,*l A. Saito,*2 T . Minemura, Y. U. Matsuyama,*2 H. Baba,*2 H. Akiyoshi, N. Aoi,*3 T. Gomi,*2
Y. Higurashi,*2 K. Ieki ,*2 N. Imai,*3 N. Iwasa,*4 H. Iwasaki,*l S. Kanno,*2 S. Kubono,*l M. Kunibu,*2
S. Michimasa,*l T. Motobayashi,*2 T. Nakamura,*5 H. Sakurai,*3 M. Serata,*2 E. Takeshita,*2
S. Takeuchi,*2 T. Teranishi,*l K. Ue,*l K . Yamada,*2 Y. Yanagisawa, and M. Ishihara[Isomeric state, "'(-"'( correlation, Radioactive beam experiment]
An isomeric 0+ state in 12Be was searched by using the projectile fragmentation of 18 0 on a Be target.
The doppler-shift corrected energy spectra for ",(-rays
and the "'(-"'( angular correlation were analyzed for determining the excitation energy and for confirming thespin, respect ively.
The experiment was performed at the RIKEN Accelerator Research Facility. A primary beam of 18 0 projectiles at 100 A MeV bombarded on a 2-g/cm 2 thick
Be target. The 12Be(*) nuclides at 60 A MeV wereselected by the RIKEN Projectile Fragment Separator(RIPS).1) The typical intensity and the purity of the
12Be beam were 2 x 10 4 pps and more than 85%, respectively. Two plastic scintillators at the second (F2)and at third (F3) focal points of the RIPS were used
for identifying the 12Be event by event by using thetime-of-flight (TOF) between the two scintillators andthe pulse heights . Here, the TOF between the production target and F3 was about 250 ns. Gamma rays
were detected by an array of 68 NaI(Tl) scintillators(DALI) about 70 cm downstream of the F3 scintillator.
Each NaI(TI) had an active volume of 12 cm (horizontal) x 6 cm (vertical) x 6 cm (along beam line). The
array was divided into 6 layers consisting of 8, 12, 14,
14, 12, and 8 NaI(TI) scintillators, each of which surrounded the beam axis. Timing signals of NaI(Tl) wereused to discriminate the true coincidence from the accidental one, and to evaluate the vertex point fromwhich the "'(-ray was emitted. The vertex point wasused for Doppler-shift corrections event-by-event. The
12Be nucleus after decay was detected by a plastic scintillator hodoscope with a 1 x 1 m 2 active area located
4 m downstream of DALI. The hodoscope consisted ofa 5-mm thick tlE plane and a 60-mm thick E plane.
The tlE plane was divided horizontally into 13 slats
and the E plane consisted of 16 horizontal bars. Particle identification was performed by using tlE-TOF
and E -TOF information.
We analyzed events where two NaI(TI) scintillators
made signals from in-flight 12Be particles, where Ehighand El ow denote the energies of the higher and lower
pulse heights of the two NaI(TI), respectively. A broad
*1

*2
*3
*4

*5

54

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

bump was found at around Ehigh = 2 Me V and E 10w =0.15 MeV. This peak became sharp after a correction
for the Doppler effect , the energies of the two ",(-rays in
the rest frame were determined to be 2.1 and 0.14 MeV,
respectively. Since the former energy corresponds tothe excitation energy of the 2+ state, a new state atabout 0 .14 MeV above the 2+, i. e. an isomeric state
at Ex = 2.24 MeV, is indicated. It is noted that asmall peak with the same excitation energy seen in
the spectrum of 10Be(t,p) reaction 2) may correspondto the present isomeric state.
In order to determine the spin of the new state,
we have examined an azimuthal angular correlationof these two "'('s with respect to the direction of the
12Be momentum. Figure 1 shows the observed angular correlation together with a theoretical prediction
assuming a cascade decay of--t--t
We conclude that the isomeric state has spin 0+ based on the
excellent fit.

ot 2t ot.

60

CIl

50

-'
~

;J

o

U

40

30

o

50

100

150

!::.¢ (deg)Fig.!. Azimuthal angular correlation pattern of 2.1-MeV
and 0.14-MeV gamma rays. The solid line denotes thetheoretical prediction assuming the 0+ --t 2+ --t 0+transition.

References
1) T . Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).
2) H. T. Fortune et al. : Phys. Rev. C 5 0 , 1355 (1994).

RIKEN Accel. Prog. Rep. 35 (2002)

Molecular states in 12Be and 14Be
A. Saito,*l S. ~h!~oura:*2 s. T~~euchi ,*~ ~. Motobayashi,*l H. Akiyoshi , Y. Ando ,* l N. Aoi,*3 Zs. Fiilop ,*4
T. Goml, Y. Hlgurashl, 1 M. Hlral,*5 N. Iwasa,*6 H. Iwasaki ,*2 Y. Iwata,*5 H. Kobayashi,*lM. Kurokawa,*2 Z. Liu,*7 T. Minemura, S. Ozawa, H. Sakurai,*3 M. Serata,*lT. Teranishi,*2 K. Yamada,*l Y. Yanagisawa, and M. Ishihara

Excited states in 12Be and 14Be were studied bymeasuring the 6He+ 6He and 6He+ 8 He breakup channels in the two-neutron removal and the inelastic scattering of an exotic 14 Be beam, respectively.
The experiment was carried out at RIPS in the
RIKEN Accelerator Research Facility. Excited statesin 12Be and 14Be were populated in the final state of
the l4Be+ 12 C interaction at an incident energy of 75
A Me V. The reaction products were measured andidentified by a hodoscope of a plastic scintillator arraywith an active area of 1 x 1 m 2 located 4.9 m downstream of the target. The decay energies for l2Be ---t
6He+ 6He and 14Be ---t 6He+ 8 He were extracted by theinvariant-mass method.
Figure 1 shows the decay-energy spectra for the
breakup channels of (a) 12Be and (b) 14Be. The peakat 1.7MeV in Fig. 1 (a) is a new excited state at
11.8 MeV in 12Be, and the others correspond to thepeaks reported in Ref. 1. Three new levels in 14Be
were found at 10.8 MeV, 11.6 MeV, and 15.5 MeV.
Angular-correlation data of decay particles were analyzed to determine the spins of these observed states.
Figure 2 shows the result for the peak at 1.7 Me V for
12Be in Fig. 1 (a) . 'IjJ is the angle of the relative velocity of the decay particles with respect to the beam
direction. 2) The solid , dashed, and dotted curves show

80

~ 60
;::!

2
20
J=4

o l..LL.l...L.LL-'--'--.LL.i....L.I--L...l..!..LJ...J..J-1.0 -05

00

0.5

1.0

cos'"

Fig. 2. Angular correlation for the peak at 1.7 MeV in
Fig. 1 (a).

the results of Monte-Carlo simulations assuming thespins of the states to be J = 0, J = 2, and J = 4,
respectively. The geometrical acceptance of the experimental setup was taken into account. For J = 2 andJ = 4, isot ropic backgrounds were assumed in addition
to a resonance contribution. Their relative magnitude
was fixed to be 2: 1. The spin of the state was assi~ned to be by comparing the X2 values (X}=o = 1.4 ,XJ=2 = 2.9, X}=4 = 2.4). In the same way, the angular correlations for the peaks in Fig. 1 (b) were also
analyzed. However we were not able to fix the spins ofthese states because of large X2 values .
Figure 3 shows the energy-spin systematics of thelevels in 12Be. The open squares correspond to thedata of Ref. 1. The solid line is the best fit to the open
squares. The solid circle represents the new excitedstate observed in the present study. According to theenergy-spin systematics, the new level may be a member of the rotational band with the 6He- 6He cluster
structure in l2Be proposed by Freer et al. 1 )

°

::v

:::il
C\l

~ 200 1:H-1f-t-H+t++++-H+1+f.1'm~

§
o

u

20

160
120

~ 15
~

80

"," 1040
410o~~~~~~~~

Decay Energy [MeV]Fig. 1. Decay-energy spectra of (a) 12Be* - t 6 He+ 6 He and(b) 14Be* - t 6 He+ 8 He.
*1 Department of Physics, Rikkyo University*2 Center for Nuclear Study, University of Tokyo
*3

*4
*5

*6
*7

Department of Physics, University of TokyoATOMKI , Hungary
National Institute of Radiological Science
Department of Physics, Tohoku University
Institute of Modern Physics, China

o

20

40

60

80

J(J+l)

Fig. 3. Energy-spin systematics of levels in 12 Be.

References
1) M . Freer et al.: Phys. Rev . Lett. 82 , 1383 (1999); M.
Freer et al.: Phys. Rev. C 63, 034301 (2001).
2) M. Freer: Nucl. Instrum. Methods Phys. Res. A 383 ,
463 (1996) .

55

RIKEN Accel. Prog. Rep. 35 (2002)

Isobaric analog state of 14Be t
S. Takeuchi ,*l s. Shimoura,*2 T. Motobayashi,* l H. Akiyoshi, Y. Ando,*l N. Aoi, *3 Zs . Fulop,*4
T . Gomi ,*l Y. Higurashi,* l M. Hirai,*5 N. Iwasa,*6 H. Iwasaki,*2 Y. Iwata,*5 H. Kobayashi,*lM. Kurokawa, *2 z. Liu,*7 T. Minemura, S. Ozawa, H. Sakurai,*3 M. Serata, *l T. Teranishi,*2
K. Yamada,* l Y . Yanagisawa, and M. Ishihara
NUCLEAR REACTIONS: 1,2He 4Be, 14 B*), 74 A MeV; Isobaric analog state; Charge]
exchange reaction; Radioactive beam experiment; Coulomb displacement energy; Halo[ structure
The halo structure of the neutron-dripline nucleus
14Be has been investigated by various approaches, suchas the interaction cross section measurement, dissociation reaction and 14Be fragmentation. 1- 4) In the recent plausible view, the mixing of sand d-wave components in the halo wave function has been suggested.
Another aspect of the structure of 14Be may be explored by studying its Isobaric Analog State (lAS).
Since the wave function of the lAS is essentially thesame as that of its isobaric partner, possible exotic natures of 14Be may be traced in properties of the lAS
such as the Coulomb displacement energy (~Ec) andthe width of the lAS. In the present study, we havemeasured the 14Be(p,n)14B* reaction in inverse kinematics at Ein = 74 A MeV .
The experiment was performed at the RIKEN Accelerator Research Facility. A secondary beam of 14Be
was produced by using the projectile fragmentation of
a 100 A MeV 18 0 beam on a 1110 mgjcm 2 thick 9Be
target, and selected by the RIPS .5) Energy of the incident 14Be beam was 74 ± 4 A MeV in the middle of asecondary target , and a typical intensity was 10 4 cps
with a purity of around 80%. After traversing throughthe plastic-scintillator detectors, the 14Be beam was
focused on a hydrogen or deuterium target with the
thicknesses of 187 and 204 mgjcm 2, respectively.
The decay particles from 14B* were detected in coincidence by a ~E- E plastic scintillator hodoscope witha 1 x 1 m 2 active area, which was located at 4.9 m downstream from the target. Information on the particle hit
position was obtained by the segmentation and timedifference between signals from two photomultipliers
attached to the both ends of each scintillator bar. Velocities of the decay particles were determined by the
TOF over the 4.9 m flight path between the target andthe hodoscope. Charged particles were identified byusing the ~E - TOF and E - TOF methods. For
neutron detection , the ~E plane served as a chargedCondensed from the article in Phys. Lett. B 515 , 255 (2001)*1 Rikkyo University*2 Center for Nuclear Study, Un iversity of Tokyo
*3
*4
*5
*6
*7

56

University of TokyoATOMKI , Hungary
National Institute of Radiological Sciences
Tohoku University
Institute of Modern Physics , China

particle veto . The momentum vectors of the decay
particles were determined by combining their velocities and hit positions on the hodoscope, and were used
to reconstruct the decay energy of 12Be+p+n system.
A prominent peak was observed in the decay energy
spectrum of 12Be+p+n channel on a hydrogen target,
while no peak was observed in t he (d, 2n) reaction,
indicating the b..S = 0 nature. The peak observedin the (p, n) reaction was assigned to the lAS of 14Be
because of the characteristics of ~S = 0, ~L = 0
derived from the angular distribution of 14B* . The
excitation energy and the width of the observed lAS
were determined to be 17.06 ± 0.03 MeV and 0.11 ±0.05 MeV (FWHM), respectively.
Coulomb displacement energy of 1.62±0.11 MeV wasdeduced between the ground state of 14Be and its lAS.
This is smaller than the ~Ec value of 1. 97 Me V forlOBe and 1.83 MeV for 12Be. This small ~Ec value
suggests spatial extension of the wave function of theexchanged proton in the lAS , indicating the halo structure of the 14Be nucleus.
A relatively large width of r = 0.11 ± 0.05 MeV was
obtained for the lAS. Assuming that 14B* (lAS) decays to the 13Be+p system, the particle-decay widths
were calculated to be rO = 0.24 MeV and rO =0.001 MeV for pure sand d-wave, respectively. The
s-wave spectroscopic factor of 45 ± 20% is extracted
from the observed width.
These results suggest a considerable contribution of
the 2S 1 / 2 orbital in the ground state of 14Be.
References
1) 1. Tanihata et al.: Phys. Lett. B 206 , 592 (1988).
2) T. Suzuki et al.: Nucl. Phys. A 658 , 313 (1999) .
3) M. Labiche et al.: Phys. Rev. Lett. 86 , 600 (2001).
4) M. Zahar et al.: Phys . Rev. C 48, R1484 (1993).
5) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70 , 309 (1992).

RIKEN Accel. Prog. Rep. 35 (2002)

Two-neutron breakup experiments on llLi, 14Be and 17B
T. Nakamura,*1 T. Sugimoto,*1 N. Fukuda, N. Aoi, *2 H. Baba,*3 D. Bazin,*4 T. Gomi,*3 N. Imai,*2
K. Hasegawa,*3 M. Ishihara, T. Kobayashi,*5 Y. Kondo,*l T. Kubo, M. Miura,*1 T. Motobayashi,*3 A. Saito,*3
H. Sakurai,*2 T. Yakushiji ,*5 Y. Yanagisawa, K. Yoneda, K. Watanabe,*5 and Y. X. Watanabe[Neutron Halo , Coulomb dissociation, Nuclear breakup]
We have studied Coulomb and nuclear dissociationsof two-neutron halo nuclei l1Li , 14Be, and 17B by akinematically complete measurement on Pb and C targets. The momentum vectors of the outgoing core fragment and two neutrons were measured in coincidence
to reconstruct the invariant mass of the excited statesof these nuclei. The aim of the experiment is to study
low-lying E1 excitation in the Coulomb dissociation l - 5)and other multipole excitations in the nuclear dissociation 5) in terms of the halo property. In addition,
the semi-exclusive spectrum, one neutron plus the corefragment, was included in the data to extract the structure of the unbound resonances of IOLi, 13Be, and 16B.
These structures are important for understanding thesingle-particle levels of neutron halo nuclei as well as
the binding mechanism of the three-body Borromean
structure. Inclusive breakup cross sections were alsomeasured to study the reaction mechanism concerning
the three-body breakup of halo nuclei.
The experiment was performed at the radioactive
beam line RIPS. An 18 0 beam at 100 MeV lu wasused to produce 11 Li and 14Be secondary beams, and22Ne at 110 MeV lu was used to produce a 17B beam.
The typical intensities of the secondary beams were
40 k cps, 6 k cps, and 700 cps for 11 Li, 14Be and 17B,
respectively. The energy of the secondary beams was
adjusted to be about 70 MeV lu on the target.
The experimental setup is shown in Fig. 1. The momentum of the beam ion was obtained by tracing the
trajectory by the two PPAC's, and by measuring thetime of flight (TOF) between a thin plastic scintillator located about 5 m upstream of the target and the
PPAC close to the target. The outgoing charged fragment was bent by the dipole magnet, and tracked by
the two drift chambers (FDCl, FDC3) at the entrance
and exit of the magnet. The time of flight measured
by the hodoscope was combined with the tracking information to extract the momentum of the fragment.
Neutrons were measured by 54 rods of plastic scintillators, each having dimensions of 214 (W) x 6 (H) x 6(D) cm 3. These rods were arranged into two walls, as

-200

o

200

[em]

Fig. 1. Experimental setup of breakup experiments on II Li,
14Be and 17B.

shown in the figure (labeled LNEUT-A and LNEUTB). The TOF and hit position of the outgoing neutron
were measured to reconstruct the momentum. The efficiency of the neutron detector was studied by a separate experiment using the 7Li(p, nfBe reaction witha Hi molecule beam at 70 MeV lu.
Thirty-six pieces of NaI(TI) surrounding the target
were used to detect the de-excitation ry rays from thecore fragment. The ry-ray information can be used toestimate the core excitation of the parent nucleus in
the breakup reactions.
An analysis of the data is now in progress.
References
1) T. Nakamura et al.: Phys. Rev. Lett. 83, 1112 (1999).
2) K. Ieki et al.: Phys. Rev. Lett. 70 , 730 (1993) .
3) S. Shimoura et al.: Phys. Lett. B 348 , 29 (1995) .
4) M. Zinser et al.: Nuel. Phys. A 619, 151 (1997).
5) T. Aumann et al.: Phys. Rev. C 59, 1252 (1999).

*1 Tokyo Institute of Technology
*2

*3
*4
*5

University of Tokyo
Rikkyo University
National Superconducting Cyclotron Laboratory, Michigan
State University, USA
Tohoku University

57

RIKEN Accel. Prog. Rep. 35 (2002)

llC(p,,) 12 N reaction studied by
the Coulomb dissociation method
T. Minemura, T. Motobayashi, *1 S. Shimoura,*2 H. Murakami,* 1 Y. Ando,*1 Y. Yanagisawa, Y. Iwata,*3
S. Ozawa, S. Takeuchi,*1 Y. Higurashi,*1 K. Yamada,*1 T. Gomi,*1 M. Serata,*1 H. Kobayashi,*1
T. Teranishi,*2 N. Aoi,*4 NI. Hirai,*3 H. Iwasaki,*2 N. Imai,*4 N. Iwasa,*5 M. Kurokawa,*2 H. Akiyoshi,
Zs. Fiilop,*6 H. Sakurai,*4 K. Yoshida, Z. Liu , and M. Ishihara[NUCLEAR REACTIONS: 208Pbe 2N,llC p)208Pb, Coulomb dissociation]
The importance of the radiative capture reaction,llC(p,,),) 12 N, at low energies has been discussed inconnection with an astrophysical nuclear burning process, called hot pp chain. I) Hence, the cross section ofllC(p,'Y) 12 N determines the critical condition for the
production of 12C in very massive stars through (3+decay2) or for the synthesis of II B in nova. 3)
In the region of astrophysical interest, there are two
resonant states in 12N: the first excited state with
J7r = 2+ at Eex = 0.960 MeV, and the second one
with 2- at 1.19 MeV. These energies correspond to thecenter-of-mass energies (Eern) for the capture reactionor the p_ll C relative energies (Erel ) in breakup measurements of 0.359 MeV and 0.589 MeV, respectively.
Concerning astrophysical implications, the most important property is the radiative width (r'Y ) of the
1.19 MeV state.
Experiments have been performed at RIKEN using
the secondary beam line, RIPS. A 77.0 MeV /nucleon
12N radioactive beam was produced through a fragmentation reaction of a primary 135 MeV/nucleon 16 0
beam. A 30 mg/cm 2 208Pb target was bombarded by asecondary 12N beam. Protons and II C produced in the
12N dissociation were detected by a plastic-scintillator
hodoscope with an active area of 1 x 1 m 2 located 5.1 m
downstream of the target. The hodoscope was set ina vacuum chamber, and consisted of two types of layers: thirteen 5 mm thick tlE layers and sixteen 60 mm
thick E layers. The energy-loss signal from the tlEplane was combined with the time-of-flight (TOF) to
identify the atomic number (Z) of each fragment. The
mass (A) was determined from a correlation between
the TOF and the energy deposit in the E layer. Theenergy of the fragment was determined by its measured
mass and the velocity obtained from the TOF. The
complete kinematics of the reaction products , the total energy and relative momentum vector of the p+ ll C
system, were thus fully determined. To measure,), rays
emitted from excited states of llC in the channel of 12N---7 p+llC* , a ')'-ray detector system, called DALI (Detector Assembly for Low Intensity radiation), consist*1 Rikkyo University*2 Center for Nuclear Study, University of Tokyo*3 National Institute of Radiological Sciences*4 University of Tokyo*5 Tohoku University*6 ATOMKI , Hungary

58

ing of sixty-four NaI(TI) scintillators , was set aroundthe target.
The experimental relative-energy spectrum is shownin Fig. 1. The closed circles represent the data obtained in the present work. The solid curve shows theresult of a Monte-Carlo simulation assuming three contributions, two resonances at Eern = 0.359 MeV and
0.589 MeV, and direct proton capture , whose magnitudes were treated as fitting parameters. The bumpobserved at around 0.6 MeV is mainly due to the E1
excitation of 12N from the 1+ ground state to the2- state at Eex = 1.19 MeV. The radiative width,r 'Y = 13.0 ± 0.5 meV, was extracted by comparing theyield of the resonance and the result of a distortedwave calculation with corrections due to the detector
response. This is in between the two different predictions by Wiescher et al. 4 ) (2 meV) and Descouvemontand Baraffe 5 ) (140 meV). The present result is consistent with that of the Coulomb dissociation experimentat GANIL 2) (6~~.5 meV), but the accuracy is greatly
improved.
20 .03(E .. =1.19)%
e"'-;; 0 .0 2
:::71

w'
"'0
"'t:>

"'8
0.0 1

3.0

Fig. 1. Relative energy spectrum obtained for the
208Pbe 2N,l1C p)2oBpb reaction. The solid curve represents the results of a Monte-Carlo simulation, comprising the three components shown by the dashed curves.

References
1) A. Jorissen et al.: Astron. Astrophys. 221 , 161 (1989).
2) P. Descouvemont et al.: Nucl. Phys. A 514 , 66 (1990).
3) M. Arnould et al.: Astron. Astrophys. 42, 55 (1975).
4) M. Wiescher et al.: Astrophy. J. 343, 352 (1989).
5) A. Lefebvre et al.: ucl. Phys. A 592 , 69 (1995).

RIKEN Accel. Prog. Rep. 35 (2002)

Low-energy El strength in 13 0
T. Minemura, T. Motobayashi,*1 S. Shimoura,*2 H. Murakami,*1 Y. Ando,*1 Y. Yanagisawa, Y. Iwata,*3
S. Ozawa, S. Takeuchi,*1 Y. Higurashi,*1 K. Yamada,*1 T. Gomi,*1 M. Serata,*1 H. Kobayashi,*1
T. Teranishi,*2 N. Aoi,*4 M. Hirai,*3 H. Iwasaki,*2 N. Imai,*4 N. Iwasa,*5 M. Kurokawa,*2
H. Akiyoshi, Zs. Fiilop,*6 H. Sakurai,*4 K. Yoshida, Z. Liu, and M. Ishihara[NUCLEAR REACTIONS: 208Pbe 30, 12 N p)208Pb , Coulomb dissociation]
We studied the low-energy E1 strength in 13 0 by
a Coulomb dissociation measurement. The process
130---+12N+p in the field of 208Pb was measured using
radioactive 13 0 beams with 83.5 MeV /nucleon incident
energy.
Only a few levels are known for 13 0, based on thepion charge-exchange reaction data,l) which has a limited the energy resolution for precise spectroscopic
studies. The nuclear structure of 13 0 is also important for evaluating the astrophysical reaction rate of
the radiative capture process, 12N(p,,)130. This reaction is expected to playa role in the hot p-p mode
nuclear burning in hydrogen-rich massive objects. 2)
A theoretical estimate was made for the 12N(p,, )130
reaction rate by Wiescher et al. 2) in their network
calculation for the hot p-p mode. The quoted resonance corresponds to the state observed in the
13C( 7r+ ,7r -) 13 0 reaction. 1)
Experiments have been performed at RIKEN using
the secondary beam line, RIPS. A 83.5 MeV /nucleon
13 0 radioactive beam was produced through a fragmentation reaction of a primary 135 MeV /nucleon 16 0
beam. A 55 mg/cm 2 208Pb target was bombarded by
the secondary 13 0 beam. The breakup fragments, 12N
and proton, were detected in coincidence after traveling through a 5.1 m flight-path by a plastic scintillator
hodoscope. From the fragments' velocities, measured
by their time-of-flight and their hit positions in thehodoscope, we could reconstruct the p_ 12 N relative energy.
Figure 1 shows the E1 strength function for 13 0
extracted from the Coulomb dissociation yield. The
dashed curve represent the line shape expect ed for ans-wave E1 resonances assuming the full single-particle
strength calculated by the R-matrix theory.3) The contribution from quadrupole excitation was estimatedfrom data taken with a carbon target in the same
setup, and was subtracted. The sum of the B(E1)strength in the range 0.5 MeV < E rel < 2.0 MeV is0.079 ± 0.003 e 2 fm 2. This is close to a prediction by
Sagawa et al. 4 ) Their large-scale shell-model calcula-

*1
*2

*3
*4

*5
*6

2.5

4.0

0.15r---~----r----'----,----.----,(E.,.=2.75 JdeV)~::II........

~

0.10

'!

~

::::::
~

Iii'
't:I

0.05

Fig. 1. Dipole strength function for 13 0 obtained from the
Coulomb dissociation yield. The dashed curve show theline shape assuming an s-wave resonance fitted to thedata around 1.2 MeV.

tion results in a large B(E1; 1) of 0.056 e 2fm 2 at around
2.9 MeV excitation energy. This large E1 amplitude
at low excitation energies is remarkable, because thelowest E1 states in other Z = 8 nuclei are locatedat higher energies of 5.17MeV 4 0) , 5.18MeV 5 0)
and 7.12 MeV 6 0). The observed large E1 strength
should considerably increase the reaction rate of the
12N(p,,)13 0 reaction compared with that predictedby Wiescher et al. ,2) because their predicted strength(f I' = 24meV) corresponds to a lower B(E1) of 0.001
e 2 fm 2 .

e

e

e

References
1) P. A. Seidl et al.: Phys. Rev. C 30 , 1076 (1984).
2) M. Wiescher et al.: Astrophys. J. 343, 352 (1989).
3) F. C. Barker and P. B. Treacy: Nucl. Phys. 38 , 33
(1962).
4) H. Sagawa, T. Suzuki, H. Iwasaki, and M. Ishihara:
Phys. Rev. C 63 , 034310 (2001).

Department of Physics, Rikkyo University
Center for Nuclear Study, University of Tokyo
National Institute of Radiological Sciences
Department of Physics, University of Tokyo
Faculty of Science, Tohoku University
ATOMKI, Hungary

59

RIKEN Accel. Prog. Rep . 35 (2002)

Study of proton resonance states in 13 0 and 12N using elastic
resonance scattering
T. Teranishi ,* 1 S. Kubono ,*1 S. Shimoura,*1 M. Notani,*1 Y. Yanagisawa, S. Michimasa,*l K . Ue,*lH. Iwasaki ,* 1 M. Kurokawa, *l Y. Sato,*1 T. Morikawa, *2 A. Saito,*3 and Zs. Flilop*4[Unstable nuclei, Nuclear astrophysics]
We have developed an in-flight low-energy RI beam
separator , CRIB,l ) under the RIKEN-CNS jointresearch program. One of the applications of lowenergy RI beams « 10 MeV/nucleon) is a study ofresonance states in unstable nuclei , which are of greatinterest for nuclear structure and nuclear astrophysics.
This report describes the first experimental result obtained at CRIB. The experiment aimed at studying resonance states in unstable nuclei, 13 0 and 12N,
via elastic scattering 12N+p and llC+p, respectively.
Data of these resonances is important to understanda hydrogen burning process at high temperature inmetal-deficient stars.
The elastic scattering was measured in inverse kinematics with RI beams , 12N and llC, and a proton target. In this situation , the center-of-mass energy andangle can be determined by measuring the energy andangle of the recoil proton at better resolution thanby measuring those of the heavy ejectile. It is useful
to apply the thick-target method,2,3) where the target
thickness is chosen to be comparable to the range ofthe beam in the target. Due to a large energy lossof the beam, a wide range of the excitation function,
da / d0, (E), of elastic scattering can be measured at thesame time. Protons were detected at forward angles in
the laboratory frame. At a fixed angle, the protonenergy spectrum has roughly the same shape as theexcitation function. In the excitation function, a resonance can be identified as an interference pattern ofpotential scattering and resonance scattering.
Secondary beams, 12N and llC, were producedby the 3HeeOB ,12 N)n and 3HeeoB,llC+p)n reactions , respectively.
A primary beam of lOB at
7.8 MeV /nucleon from the AVF cyclotron has an intensity of 200 pnA. The production target was a cell
containing 3He gas with a thickness of 0.25 mg/cm 2.
The secondary beams were separated by CRIB withan energy degrader of 10-/-im mylar foil at the dispersive focal plane. The beam obtained was a mixtureof 12N (3%) at 3.9 MeV /nucleon and llC (15%) at
3.4 MeV /nucleon. The total secondary-beam intensity
was about 105 particles/sec. The experimental setup
was installed at the dispersive focal plane of CRIB.
The setup consisted of two PPACs for beam tagging,*1 Center for Nuclear Study, University of Tokyo*2 Department of Physics , Kyushu University*3 Department of Physics, Rikkyo University*460

ATOMKI, Hungary

(a)

30

Ei 3o) =2.75 MeV

4.21

25

~

~

---~ 20
~

~ 15

'6
"0 10

4

6

10

12

3.13

E x 2N) =3.56 MeV

1

1

6

Ep (MeV)

e

30

(b)

25

~ 20

.96 1.19

1.80

2.44

11

1

1

~

,II,

c: 15
"0
'6 10
"0

III I
1
1111110011111111111111111111
111l!
I

IIII!
I,

I

4

6

10

Ep (MeV)Fig. 1. Preliminary experimental results of the proton spectra for (a) 12N+p and (b) llC+p elastic resonance scattering.

a CH 2 target of 90/-im and a set of flE-E silicon detectors, which covered scattering angles of 0- 50 for therecoil protons.
Figure 1 (a) and (b) show preliminary results of the
proton energy spectra for 12N+p and llC+p, respectively. In the spectra, many resonance states in 13 0
and 12N were identified. The analysis of the spectra using resonance formulae is now in progress. The valuesof the width, spin and parity will be newly determined
for the resonance states at E x = 2.75 and 4.21 MeV in
13 0 and E x = 3.13 MeV in 12N.
References
1) Y. Yanagisawa et al.: RIKEN Accel. Prog. Rep. 34, 183(2001).
2) K. P; Artemov et al.: SOy. J. Nucl. Phys. 52, 408 (1990).
3) S. Kubono: Nucl. Phys. A 693, 221 (2001), and references therein.

RIKEN Accel. Prog. Rep. 35 (2002)

Projectile fragmentation of 14 0 at 60 A MeV on 4He
H. Baba,*l s. Shimoura,*2 T. Minemura, Y. u. Matsuyama,*l A. Saito,*l H. Akiyoshi, N. Aoi,*3 T. Gomi,*lY. Higurashi,*l K. Ieki,*l N. Imai,*3 N. Iwasa,*4 H. Iwasaki,*3 S. Kanno,*l S. Kubono,*2 M. Kunibu,*lS. Michimasa,*2 T. Motobayashi,*l T. Nakamura,*5 H. Sakurai,*3 M . Serata,* l E. Takeshita,*lS. Takeuchi,*l T. Teranishi,*2 K. Ue,*2 K. Yamada,*l and Y. Yanagisawa[NUCLEAR REACTIONS: 4He(14 0, X), 60 A MeV; Projectile fragmentation]
We have studied the systematics of the production
cross sections of light isotopes for the projectile fragmentation of 14 0 at 60 A MeV on a liquid-helium
target. The experiment was performed at the RIPS
(RIKEN projectile-fragment separator) beam line. A
beam of 14 0 was produced by the fragmentation ofan 16 0 beam at 135 A MeV on a 9Be target with athickness of 1295 mg/cm 2. The 14 0 nucleus and contaminants were identified using time-of-flight (TOF)
information obtained from two 0.5 mm thick plastic
scintillators separated by 5.3 m from each other. The
14 0 beam bombarded a 100 mg/cm 2 liquid-helium target. Reaction products were identified using a ~E-E
plastic hodoscope 1) 4 m downstream from the target.
The scattered angles of the particles were determinedby hit positions in the hodoscope. The hodoscope consisted of ~E and E plastic scintillators of 5 and 60 mm
thicknesses.
The production cross sections from the reaction of
4He(14 0 , X) at 60 A MeV were measured, and compared with a calculation using an empirical parameterization code, EPAX. 2) The observed cross sections
were determined by identified particle counts in thehodoscope at the target-in run and the target-out run.
The particle acceptances of the hodoscope were derived based on information of the angular distribution.
These results are shown in Fig. 1. The closed circles
indicate the measured production cross sections. Some
nuclei have not been observed due to the too-short
lifetimes or too-small cross sections. The solid histogram represents the EPAX calculations. The dotted
histogram represents the EPAX calculations, including
decay products from unbound nuclei, such as 5He ---+
4He + n , 4Li ---+ 3He + p, 5Li ---+ 4He + p, 6Be ---+
4He + p + p, 8Be ---+ 4He + 4He, 9B ---+ 4He + 4He + p.
EPAX reproduced the global tendency of the crosssections obtained in the present measurement, although considerable differences in the absolute value
was found for 8Li, lOBe and carbon isotopes. For
nuetron-rich fragments of 8Li and lOBe, the cross sections were much smaller than EPAX. Fragments of

10 2
10 1
100

:0

5
~

0

:;:1

10 2
10 1
10 0

C.l

Q)

if.!
fIl
fIl

0

s-.

u

10 2
10 1
10 0
10 2
10 1
100
5

10

5

10

Mass Number (A)Fig. 1. Cross sec to ins from the reaction 4HeC 4 0 , X) at 60
A Me V. The closed circles indicate the measured production cross sections. The histograms represent the
EPAX calculations. The statistical error is generally
smaller than the size of the data points.

6He, 8He and 9Li were not observed. This indicatesthat fragments located on the opposite side of the f3
stable line to the projectile are difficult to produce inthe fragmentation reactions.
For all carbon isotopes, the cross sections are tentimes larger than those found by EPAX calculations.
This discrepancy is possibly due to the sizeable effectof the inelastic excitation to the states above the particle emission threshold. An analysis including suchinelastic scattering is in progress.
References
1) 1. Hisanaga et al.: RIKEN Accel. Prog. Rep. 31 , 162(1998).
2) K. Siimmerer and B. Blank: Phys. Rev. C 61, 034607(2000).

*1 Department of Physics, Rikkyo University
*2

*3
*4
*5

Center for Nuclear Study, University of Tokyo
Department of Physics, University of Tokyo
Faculty of Science, Tohoku University
Department of Applied Physics, Tokyo Institute of Technology

61

RIKEN Accel. Prog. Rep. 35 (2002)

Coulomb dissociation of 13N and 14 0
M. Serata,*l T. Motobayashi,*l S. Shimoura,*2 H. Akiyoshi, Y. Ando ,*l N. Aoi ,*2 Zs. Fiilop,*3 T. Gomi,*lY . Higurashi ,*l M. Hirai ,*4 K . Ieki ,* l N. Imai,*2 N. Iwasa,*5 H. Iwasaki,*2 Y. Iwata, *4 H. Kobayashi,*lM. Kurokawa,*2 T . Minemura, H . Murakami,*l S. Ozawa, H. Sakurai,*2 S. Takeuchi ,* l T. Teranishi,*2
K. Yamada,*l Y. Yanagisawa, K. Yoshida, Z. Liu , and M. Ishihara
NUCLEAR REACTIONS: 208Pbe 3N,p 12 C)208Pb, 76 AMeV; 208Pbe 40,p13N)208Pb, 85][ AMe V; Coulomb dissociation
In order to test the Coulomb dissociation method 1)
in extracting radiative-capture cross sections ofastrophysical interest , we studied the processes
13N --+ 12 C+p and 140--+13N +p in the field of 208Pb
via the lowest E1 resonances in 13N (1/2+; Eex =2.37MeV) and 14 0 (1-; E ex = 5.17MeV), respectively. The earlier results of the 14 0 dissociation at
RIKEN 2) and GANIL 3) agreed with a direct measurement performed at Louvain-La-Neuve. 4) The RIKEN
experiment 2) also measured the 13N dissociation, andthe extracted E1 strength was consistent with that obtained from direct measurements of the 12C(p,I')13N
reaction. However, these agreements were confirmed
at accuracies of around 30%. The present experiment
was aimed at improving the experimental accuracy.
Radioactive beams of 13N and 14 0 were provided
by using the projectile fragmentation of a 135 A MeV
16 0 beam with a 1.4 g/cm 2 Be target. The 13N and
14 0 beams were separated by the RIPS facility,5) andbombarded a Pb target with a thickness of 55 mg/cm 2.
The averaged energies were 76 A Me V and 85 A Me V,
respectively, for 13N and 14 0 at the middle of the target. Outgoing charged particles were detected in coincidence by a tlE-E hodoscope ,6) and their velocities were measured by the time-of-flight. The relative energies of the breakup fragments were calculated
from their velocities and relative angle. An array of
64 NaI(TI) scintillators was placed around the target to detect l'-rays with the process 13N--+ 12C*(2+;4.44 MeV)+p, which can not be separated from the
12C(0+; g.s.)+p dissociaton by only measuring thefragments.
Figure 1 shows the angular distributions of the experimental yield together with theoritical predictions
normalized to the data. The energy resolution andthe coincidence efficiency were taken into account ina theoretical calculation based on the distorted-wave
therory, assuming pure E1 Coulomb excitation. As
seen in the figures , the experimental distribtuions canbe fairly well reproduced by the calculations, especiallyfor the 13N dissociation. The normalization factors

*1

*2

*3
*4
*5

62

R ikkyo University
University of TokyoATOMKI, Hungary
National Institute of Radiological Sciences
Tohoku University

fda / de(mb/r~g~ <=='TT"'"T'T"l",...,.-rrTTTT.,.,.-rrTTT~
20BPb(,3N.13N · (1 / 2 +»20Bpb

20Bp b( 14 0 . 14 0'( 1-»20B pb

E(13 N)=76 A MeVE(,40)=85 A MeVe(deg.)e(deg .)

Fig. 1. Experimental and calculated angular distributions
for the reactions 20Bpbe 3N, p 12 C)20Bpb (left part) and
20BPbC 4 0, p 13 N)20Bpb (right part).

elead to radiative widths of 0.52 ± 0.04eV 3 N) and
2.8 ± 0.2eV (140) . The former is in very good agreement with the adopted value, 0.50 ± 0.04 eV, basedon direct 12C(p,I') 13N measurements. Thus, the reliability of the Coulomb dissociation method has beentested to an accuracy of the order of 10% in this case.
The extracted width for 14 0 agrees within the errors
with the results by the previous Coulomb dissociation
experiments, 3.1 ±0.6 eV 2) and 2.4±0.9 eV,3) and thatby the direct capture measurment , 3.8 ± 1.2 eV. 4)
References
1) G. Baur et al.: Nucl. Phys. A 458, 188 (1986).
2) T. Motobayashi et al.: Phys. Lett. B 264, 259 (1991).
3) J . Kiener et al.: Nucl. Phys. A 552 , 66 (1993) .
4) P. Decrock et al.: Phys. Rev. Lett. 67, 808 (1991).
5) T. Kubo et al.: Nucl. lnstrum. Methods Phys. Res. B
70, 309 (1992).
6) 1. Hisanaga et al.: RlKEN Accel. Prog. Rep. 3 1 , 162(1998).

RIKEN Accel. Prog. Rep. 35 (2002)

El strength of the subthreshold 3/2+ state in 15 0 and its influenceon the eNO reaction 14N(p,,)150
K. Yamada,*l T. Motobayashi,*l H. Akiyoshi, N. Aoi,*2 Zs. Fiilop,*3 T. Gomi,*l Y. Higurashi ,*l N. Imai ,*2
N. Iwasa,*4 H. Iwasaki,*5 Y. Iwata,*6 H. Kobayashi,*l M. Kurokawa,*5 Z. Liu,*7 T. Minemura, S. Ozawa,
H. Sakurai,*2 M. Serata,*l S. Shimoura,*5 S. Takeuchi,*l T. Teranishi,*5 Y. Yanagisawa, K. Yoshida,
and M. Ishihara
NUCLEAR REACTIONS: Pbe50,150I') ,[astrophysics
The Coulomb excitation of 15 0 was studied to determine the radiative width (r'Y) of the 3/2+ state in 15 0.
The higher tail of the state may affect the low-energy
behavior of the reaction, which is important for the
astrophysical rate of the CNO reaction 14N(p,I')150.
The experiment was performed at RIPS 1) at the
RIKEN Accelerator Research Facility. A secondary
15 0 beam with an energy of 100 A MeV was focusedon a lead target and excited by the Coulomb force.
The de-excitation l'-ray was detected by a NaI(TI)scintillator array with 64 crystals. The scattered particles were detected by a plastic scintillator hodoscope 2)
consisting of a 5 mm thick ~E plane and a 60 mm thickE plane. Details of the setup are described in Ref. 3.
Figure 1 shows the Doppler-corrected l'-ray energy
spectrum measured in coincidence with inelasticallyscattered 15 0 detected by detectors at the angle () =63°. The peak observed at 3.6MeV is due to background photons originating from the target excitation,
which corresponds to the 2+ state at 4.1 MeV in 208Pb.
No distinct peak can be seen at 6.79 MeV, where theyield due to the 3/2+ --+ g.s. transition is expected.
We fitted the experimental spectrum by five components: three ground-state transitions from the 5.24,
6.18 and 6.79 MeV states in 15 0 , the l'-ray spectrum
due to the target excitation, and an exponential background . The line shapes for the transitions were obtained by a simulation which took into account thedetector response. The spectrum for the target excitation was evaluated by data taken by detectors at a
backward angle, where photons from 15 0 are greatly
reduced due to the Doppler shift. The solid curve inthe figure shows the result of the fit. The peak at
5.2 MeV is due mainly to direct excitation of the 1/2+
and 5/2+ states at 5.183 MeV and 5.241 MeV, respectively, and also the feeding of the 5/2+ state from thehigher 5/2+ state at 6.859 MeV and the 7/2+ state at
7.276 MeV. The dotted curve indicates the evaluatedspectrum for the target excitation, and the straight
*1

*2
*3
*4

*5

*6
*7

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

100 AMeV; Coulomb excitation,

NUclear]

6000

6000

Energy (keV)

Fig. 1. Doppler-corrected 1'-ray spectrum measured in coincidence with 15 0 and fitted by five components.

dashed line is the exponential background. The result of the fit for the component of the 3/2+ state at
6. 793 MeV is shown by the solid curve.
The radiative width, r 'Y = 1.44 ~g:!~ eV, for the
3/2+ state is extracted by comparing the measured
cross section and the DWBA calculation assuming E1
Coulomb excitation. Considering the possible contribution from minor gamma transitions from otherstates, a fair estimate of the 10" upper limit of the radiative width is 1.6 eV. This result is consistent witha recent lifetime measurement by the Doppler-shift attenuation method. 4) Their result corresponds to thewidth r'Y = 0.41 ~g:i~ eV. Thus only a minor effect of the 3/2+ state is expected for the low-energy
14N(p,I')150 cross section.
References
1) T. Kubo et al.: Nucl. Instrum. Methods Phys. Res. B
70, 309 (1992).
2) I. Hisanaga et al. : RIKEN Accel. Prog. Rep. 31 , 162(1998) .
3) K. Yamada et al.: RIKEN Accel. Prog. Rep. 33, 67(2000) .
4) P. F. Bertone et al.: Phys. Rev. Lett . 87, 152501 (2001) .

63

RIKEN Accel. Prog. Rep. 35 (2002)

Measurements of the reaction cross sections of
C isotopes at intermediate energy
T. Yamaguchi, T. Zheng,*1,*2 A. Ozawa, M. Chiba, *3 R. Kanungo, T. Kato , K . Katori , K. Morimoto,
T. Ohnishi, T. Suda, I. Tanihata, Y. Yamaguchi,*4 A. Yoshida, and K. Yoshida[NUCLEAR REACTION: Bee 2Ne, 16C); E = llOA MeV; Measured reaction cross sections]
The interaction and reaction cross sections of unstable nuclei have been measured so far all over theworld to investigate their radii and density distributions. Recently, interaction cross sections of carbon
isotopes were measured at high energy, ~ 960A Me V
at GSI. I ) The interaction cross section can be related
to the interaction radius. For stable nuclei, the interaction radii were found to follow TI ex A I / 3 , l) where
A is the mass number. After applying this relation
to neutron-rich carbon isotopes, however, it was foundthat the cross section at A = 16 greatly deviates fromthis property. This might suggest the anomaly of nuclear structures near I6C. Based on this result, thereaction cross sections for I2 ,14- I6C were measured atintermediate energies (50A and 80A MeV) to study thedensity distributions of these carbon isotopes.
According to Glauber theory,2) the reaction crosssection is given by the product of the nucleon densities of the projectile and the target , multiplied by the
nucleon-nucleon cross sections. Because the nucleonnucleon cross sections become larger at lower energy,
the reaction cross sections at lower energy become
more sensitive to the outer part of the density. Thus ,in principle, the density distributions of the projectiles can be studied based on the energy dependenceof the cross sections. The reaction cross sections at
both intermediate and high energyI) are analyzed todetermine the density distributions.
In the present experiment we applied a new technique to the transmission method to measure the reaction cross sections. A schematic drawing of the experimental setup is shown in Fig. l.
The experiment was performed using the RIKEN
Projectile fragment Separator (RIPS). C beams were
produced by bombarding a 22Ne beam with llOA MeV
on a Be target, which was located at FO , and transported to the dispersive focus , Fl. After B p selection
and an energy-loss analysis by a wedge degrader , they
arrived at the F2 focus achromatically, where the reaction target C (20 mm) was placed. Then , the projectiles as well as the reaction products were transported
and focused by the quadrupole triplet to the final focus, F3 , which was ~6 m downstream , as shown in
Fig. l.
*1

*2

*3
*4

64

Peking Universit y, China
Tokyo University of Science
Tohoku University
Niigata U niversity

2~eFig. 1. Schematic depiction of the experimental setup.

Particle identification before the reaction target wasdone by means of Bp-f:::.E-TOF method. The detector
system commonly used at RIPS was applied to countand identify the incident particles. One more parallel
plate avalanche counter (PPAC) was installed to define
the beam emittance at F2.
After the reaction target , the TOF-f:::.E-E method
was applied to identify the outgoing particles. Thismethod provides good mass separation due to goodtime and energy resolutions for time-of-flight (TOF)
and E counters. Thin plastic scintillation counterswere used to measure the TOF between F2 and F3,
and aNal (3" cp, 60 mm) counter was applied to E measurements. For Z identification, three silicon detectors(50 x 50 mm 2, 150/-Lm) were placed in front of the NaI
counter.
In this experiment, transmission from F2 to F3 is important to determine the cross sections precisely. For
I2C, transmission of more than 98% was obtained without the reaction target when the emittance cut wasapplied at F2 before the reaction target. The resultof the cross section of I2C is consistent with a phenomenological parameterization of the reaction crosssections given by Kox et al. 3) For I6C, a larger enhancement of the cross section at intermediate energy
has been observed compared with that of high energy
relative to the calculation. Further analysis is ongoing.
References
1) A. Ozawa et al.: Nucl. Phys. A 693 , 32 (2001) andreferences therein.
2) R. J. Glauber: in Lectures in Theoretical Physics, Vol. 1(1959) , p. 315.
3) S. Kox et al.: Phys. Rev. C 35 , 1678 (1987).

RIKEN Accel. Prog. Rep. 35 (2002)

Study of the spin polarization of 19C for a g-factor measurement
D. Kameda,*1 H. Ueno, K. Asahi, H. Miyoshi,*1 A. Yoshimi , W. Sato, H. Watanabe, N. Imai ,*2 J. Murata,
K. Shimada,d J. Kaihara,* 1 K. Yoneda, T. Koike,*1 Y . Kobayashi, and H. Ogawa*3[NUCLEAR STRUCTURE, 19C, Spin polarization, ,6-NMR method]
Based on the ,6-NMR method for spin-polarizedradioactive-isotope beams, the 9 factor of the groundstate of light unstable nuclei has been measured. 1) For
measuring 9 factors , it is important to produce spinpolarization in the projectile fragmentation reaction.
In the present work, magnitude of the spin polarizationof 19C was studied. In the case of 19C, the groundstate 9 factor is extremely sensitive to whether the
spin-parity is J7r = 1/2+,3/2+,5/2+, which are possible candidates for the ground state; the corresponding Schmidt value are g81 /2 = -3.83 , gd 3 / 2 = +0.77 ,and gd 5 / 2 = -0.77. Similar observations are gainedin more realistic shell-mode calculations.2) Owing to
the large difference , the spin-parity can be assigned bymeasuring the 9 factor as a different approach using
nuclear-reaction studies. 3)
A beam of 19C was obtained from the fragmentationof 22Ne projectiles at an energy of 110 MeV /nucleon
on a 9Be target of 736 mg/cm 2 thickness. In order toproduce spin polarization, the 19C fragments were accepted by RIPS at emission angle of eL = 0.8 0 - 6.20
and a momentum of PF = 7.95 - 8.44 GeV /c. The
19C fragments were then isotope-separated and implanted in a stopper material to which a magnetic fieldof Eo = 40.07 mT was applied. For measuring the spinpolarization (P), appropriate stopper materials should
be chosen so that they cat provide a sufficiently longrelaxation time compared with the ,6-decay lifetime of
19C (7 = 65.6ms). In the case of J7r(19C g . s .) = 1/2+,
graphite can be used for this purpose. 1) This material, however , might not be applicable for the casesof J7r(19C g .s . ) = 3/2+ and 5/2+ because of the effectof 19C quadrupole relaxation. For these cases, Pt is
known to be applicable by studying the 17 C g-factor
measurement. 1) Conversely, Pt cannot be used for the
J7r (l9C g .s .) = 1/2+ case because of the short relaxation
time expected from its large 9 factor.
The value of A,6 p(19C g .s .) were measured by meansof the adiabatic field rotation method using a similar experimental setup, described in Ref. 1, whereA,6 is the ,6-ray asymmetry factor. Based on thistechnique, the value of A,6p(19C g .s .) can be determined without any information concerning the 9 factor. In measurements with graphite and Pt stoppers,
A ,6 p(19C g .s .) = -0 .29±0.17% and -0.18±0.26% wereobserved, respectively.
Although the obtained statistics do not permit detailed discussions , it can be said that the spin polarization is very small in all cases of J7r (19 C g .s .). Three
possibilities can be considered for the observed small
polarization. Firstly, the polarization appears to bediminished because of the large background. Figure 1
shows a decay curve accumulated in the 19C ,6 decay.
The large background is due to the daughter nuclei
after 19C ,6 decay. Secondly, non-vanishing angularmomentum due to the Fermi motion in a group of nucleons in the projectile that is removed through thefragmentation process, which is essential mechanismof the spin polarization,l) can not be expected if thespin-parity of the ground state is 1/2+. Finally, it is
known from our previous studies that fragments can
not be spin-polarized using a Be target in some cases,
although it has an advantage concerning the yield. An
experiment with another target, such as 93Nb, is underconsideration.
9000.-----~----~----~------~----~-,

(f)

E
(f)

5000

background

"E::J

/

o

()

------------------------------------17 B component------(--

o~----~~~~----~------~----~~

o

10

20

30

40

50

Time (ms)Fig. 1. .8-decay curve accumulated in the present measurement. The two main components obtained from thefitting analysis are shown together with that of 19C(thick dotted curve). The thick line and the thin dottedcurve show a constant background due to the long-lived
daughter nuclei and 17B implanted as a beam contamination , respectively.

References
1) K. Asahi et al.: RIKEN Rev. , No. 39 , 142 (2001).

2) B. A. Brown et al: OXBASH, MSU eycI. Lab. Rep. ,
*1
*2

*3

Department of Physics, Tokyo Institute of Technology
Department of Physics, University of Tokyo
National Institute of Advanced Industrial Science and Technology

No. 524 , 1 (1986).
3) R. Kanungo et aI.: NucI. Phys. A 677, 171 (2000).

65RIKEN Accel. Prog. Rep. 35 (2002)

Search for 21 B
A. Ozawa, Y. Yamaguchi,*1 T . Izumikawa,*1 R. Kanungo, T. Kato,*1 Y. Kawamura,*1 K. Kimura,*2
S. Momota,*3 T. Onishi , T. Suda, T. Suzuki,*1 1. Tanihata, T . Yamaguchi, K. Yoshida, and T. Zheng*4[NUCLEAR REACTIONS: 9Be(40 Ar,X), E(40 Ar) = 94 A MeV]
A very neutron-rich nucleus , 21 B, has been searchedbased on motivation concerning the N = 16 magic
number. 1) In a previous report,2) the motivation forthis experiment and the experimental setup for the firstattempt were described in detail. In this report , we
describe the experimental setup for the second attempt
and the results of a search.
The experimental setup at RIPS for the second attempt is almost similar to the previous one. The maindifferences are the installation of a plastic scintillator
at F1 (thickness = 0.5 mm), which provides timing andanalog signals, and the use of a Ta production target instead of a Be target, as in the previous experiment. The 40 Ar beam was accelerated at the AVF
and RIKEN Ring Cyclrotron up to 94 A MeV andreacted with a 681 mg/cm 2 thick Ta target. The typical primary beam intensity was 41 pnA. The magnetic
rigidity of the first half of RIPS was set at 5.616 Tm
in order to optimize the yield of the 21 B isotopes . To
reduce the relative rates of light isotopes, a thin aluminum wedge with a mean thickness of 223 mg/cm 2
was used at F1. The magnetic rigidity of the second
part of the RIPS spectrometer was thereby adjusted
to 5.530 Tm.
Particle identification was performed by a standard
method based on the energy loss (tlE), time-of-flight(TO F) and magnetic rigidity (Bp) measured for eachfragment. The TOF of each fragment was determinedfrom the F2-Pl timing and the F1-PI timing. Two SSD
detectors at F2 provided independent energy-loss values (tlE). Additional energy-loss values were obtained
from F1-Pl. The magnetic fields at the two dipoles
were monitored by NMR probes.
The Ta production t arget was irradiated for 121.5
hours in total. Particle identification for the 21 B setting showed 16 events of the candidate. However, theidentification suffered from serious background due toscattered light particles, mainly 11 Li. In order to confirm Z = 5 as candidates, we checked the energy-loss
value from F1-Pl. The energy-loss values of all 21 B
candidates coincided with those in 11 Li. Thus, we conclude that those candidates were scattered particles of
11 Li , and. no event for 21 B was observed in this measurement.
To show the particle instability of 21 B, we measured
the production cross sections for B-isotopes with the
*1
*2

*3
*4

66

Niigata University
Nagasaki Institute of Applied Science
Kochi University of Technology
Tokyo University of Sciencesame experimental setup using Be and Ta targets. To
deduce the production cross sections, we need to know
the transmission efficiency from FO to F2 in RIPS. We
used MOCADI simulations3) to obtain the transmission. The present cross sections are shown in Fig. 1.
Previously, Momota et al. measured the production
cross section for a reaction of 40 Ar + Be with 90 A
MeV. 4) For 15B, our present data is consistent withthis value, which shows the validity of the MOCADI
simulations.
The present results of the 21 B search only gave an
upper limit of the production cross sections of 21 B,
as shown in Fig. 1. The upper limit is much smaller(factor of 12) than the production cross sections extrapolated by EPAX,5) which were normalized to ourexperimental cross sections. Thus, this large discrepancy shows the particle instability of 21 B.
10 2
0

:0-

0

E 100

0

'-'

C

0

10-2

u
Q)

10-4

0
0

'.j:i

<f

(f)
(f)

0

II
10-6

•

10-8

II

~

u
C

0

'. j:ig 10-10T"0

ea. 10-12
9

11

13

15

17

19

21

23

mass number

Fig. 1. Experimental production cross section for B isotopes produced with an 40 Ar primary beam at 94 A
MeV on Be (squares) and Ta (circles) targets. The
closed marks show the present data. The open squares
show the previous data. 4 ) The upper limit of the production cross section of 21B is shown by the arrow. The
curve shows the extrapolation of the experimental datausing EPAX parameterization. 5 )References
1) A. Ozawa et al.: Phys. Rev. Lett. 84, 5493 (2000).
2) A. Ozawa et al.: RIKEN Accel. Prog. Rep. 34, 72(2001).

3) N. Iwasa et al.: Nucl. lnstrum. Methods Phys. Res. B
126, 284 (1997).
4) S. Momota et al.: Nucl. Phys. A , in press.
5) K. Siimmerer et al.: Phys. Rev. C 61, 034607 (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of the longitudinal momentum distribution of 220
M. Chiba,*l R. Kanungo, N. Iwasa,*l S. Nishimura, A. Ozawa, C. Samanta,*2
T. Suda, T . Suzuki,*3 T. Yamaguchi, T. Zheng, and 1. Tanihata[NUCLEAR STRUCTURE; 220, Momentum distiribution, TOF]
We measured the longitudinal momentum distribution of 220 via a break-up reaction. Measuring the longitudinal momentum distribution of neutron-rich nuclei enables us to investigate nuclear structures. The
shape of the longitudinal momentum distribution ofvalence neutrons provides information about the orbits occupied by them.
Usually, the momentum distribution is measured
with a magnetic spectrometer. The present measurement was based on a time-of-flight (TOF) techniquewith nearly full acceptance. This helped to reducecomplexities arising due to a finite spectrometer acceptance.
The experiment was performed using the RIKEN
projectile fragment separator (RIPS). The experimental setup is shown in Fig. 1. A primary 40 Ar beam at
93.7 A MeV was impinged on a 280 mgjcm 2 Be target
to produce an 220 secondary beam. The RIPS was operated in an achromatic mode with a 425 mgjcm 2 aluminum wedge degrader and a momentum acceptanceof 0.8%. We installed a 0.5 mm thick plastic scintillator at the dispersive focus, F1. The typical count rateof the plastic detector at F1 was~ 106 Hz.
The 220 beam was bombarded onto a 450 mgjcm 2
carbon target installed at the first achromatic focus
F2. After the carbon target, we installed a 0.5 mm
thick plastic scintillator at F2. Another 1.5 mm thickscintillator was located 5.5 m downstream at the final
achromatic focus , F3. To monitor the beam size weinstalled parallel plate avalanche counters (PPAC) at

F3

F2~PllStiC'\ "AC
Degrader\\\Lllle \\~ \C targetSi"AC

all foci.
Particle identification (PID) before the carbon target was performed by the magnet rigidity (Bp ) - ~E­
TOF method . Bp information was obtained from position information of a PPAC in F1. .6.E and TOF
information were obtained from a 350 11m Si detector
at F2 and two plastic detectors at F1 and F2, respectively.
After the carbon target, reaction products were identified by the .6.E-TOF-E method . .6.E information was
obtained from a stack of 17 Si detectors. TOF infromation was obtained from two plastic detectors at F2
and F3. The total energy information was obtained
from a 3" ¢ x 6 cm NaI(TI) detector positioned at theend of beam line. The typical energy resolution of the
NaI(TI) detector was ~ 1% in FWHM for 65 A MeV
21 0.
A typical TOF-E plot is shown in Fig. 2. We could
identify the one neutron removal fragment , 21 0, andthe unreacted 220. The population ratio of 21 0 to 220
was ~ 1.0 x 10- 3. In addition, a few of the two-neutron
removal fargment 20 0 were observed.
The main source of the background was nuclear reaction events which occured in the NaI(TI) detector,
because the shape of the background in the TOF spectrum was the same as that of unreacted 220.
To reduce the background , we are now developing a
nuclear reaction-suppressed total-energy detector system. The data analysis is still in progress.

\1117

Nil

Plastic
PPAC

40A r

Fig. 1. Experimental setup.

*1

*2
*3

Fig. 2. Particle identification spectrum for fragments of
220 at the final achromatic focus, F3.

Tohoku University
Saha Institute of Nuclear Physics, India
Niigata University

67

RIKEN Accel. Prog. Rep. 35 (2002)

First experimental evidence of core modification
in a near drip-line nucleus, 23 0
R. Kanungo, M. Chiba, N. Iwasa,* 1 S. Nishimura, A. Ozawa, C. Samanta,*2 ,*3 T. Suda,
T. Suzuki,*4 T. Yamaguchi, T. Zheng, and I. Tanihata[Momentum distribution, Halo, time-of-flight]
The measured interaction cross sections 1) ofneutron-rich N, 0, F isotopes indicate an abrupt rise in
the cross section the N = 15 isotopes. This is expected
to be a signature of halo formation. However, ananomaly arises in understanding the observed enhancement of the cross-sections within the usual core-plusneutron halo model. Namely, in such an approach, aconsideration of the neutron occupying the 2S 1 / 2 orbital is insufficient to explain the amount of enhancement. This has led to the proposition of new form of
core-modified structure for these isotopes. 2) It shouldbe mentioned here that the usual halo model considers
the core to have same size and properties as a free nucleus. The usual halo model has successfully described
the known halo nuclei in thep-shell region. We conducted a further experimental investigation to probe
the cause for such a structure through a measurementof the longitudinal momentum distribution of 23 0.
The experimental technique adopted for this purpose was a new one based on the time-of-flight principle. The salient feature of this technique in comparison
to the usually adopted spectrometer technique is thatthe breakup fragments are transported to the final focus after the reaction target without passing throughany dipole magnet. This has helped us to obtain anearly full acceptance. The advantage of this feature
is not only that the extraction of the momentum distribution becomes relatively simple, covering a large
momentum range , but also that the measurements canbe made at the same time for multi-nucleon removal,
proton knock out and pickup reactions. Furthermore,
it allows measurements of the interaction cross sections
with the same experimental setup. The details on of
the setup are discussed in Ref. 3.
In the present experiment, the longitudinal momentum distributions of fragments from the two-neutron
removal as well as one-neutron removal from 23 0 ina reaction with a C-target at 72 A MeV were measured. The unexpectedly narrow width of 21 0 (115 ±34 MeV Ic in FWHM) from fragmentation of 23 0 is thefirst direct evidence of a change in the structure of 220*1 Department of Physics, Tohoku University*2 Present address : Physics Department, Virginia Commonwealth University, USA*3 Permanent address: Saha Institute of Nuclear Physics, India*4

68

Department of Physics , Niigata University

inside 23 0 compared to the bare 220 nucleus. A theoretical interpretation of the present data considering
neutron correlation is an involved study, no formalismof which yet exists. Therefore, at present we interpret the data by folding the momentum distributionsof 230---t220 and 220---t 21 0, which also considers thesimultaneous emission of the two neutrons. Taking
into account all possibilities of two-neutron removal
through the ground as well as excited states of 220, in
a normal shell model configuration (i. e. J7f = 1/2+ for
23 0), we obtained a distribution which is wider thanthe observed one. On the other , hand if we assume thepossibilty of two neutrons in 230 to be emitted fromthe 231 / 2 orbital (which would mean one of the neutrons in the so-called 220 core is in the 2S 1 / 2 orbital),
we obtain a consistent description of the two-neutron
removal distribution. It should be mentioned here thatboth the interaction cross section and the momentum
distribution analysis of free 220 indicate that the valence neutron is in the 1d5 / 2 orbital.
This observation indicates a strong modification of
the core structure for neutron halo-like 3d shell nuclei
near the drip-line. The probability of two neutrons
occupying the s-orbital in 23 0 may suggest the lowering of the s-orbital, thus providing a reason for the
N = 16 magic number. This also introduces a new
two-fold definition of a valence nucleon, one which determines the spin of the nucleus, and the other which
participates with greater probability in the reaction.
The 220 momentum distribution from 23 0 fragmentation shows a width of 73 ± 15 MeV Ic in FWHM. In
the same experiment we also measured the longitudinal momentum distribution of one-neutron removalfrom 220. This is reported in Ref. 3.
References
1) A. Ozawa et al.: Nucl. Phys. A 691 , 599 (2001).
2) R. Kanungo et al.: Phys. Lett. B 512 , 261 (2001).
3) M. Chiba et al.: RIKEN Accel. Prog. Rep. 35 , 67
(2002) .

RIKEN Accel. Prog. Rep. 35 (2002)

Study of the 22Mg(p,,)23 Al reaction
by the Coulomb-dissociation method
T. Gomi,*l T. Motobayashi,*l K. Yoneda, S. Kanno,* l N. Aoi,*2 Y. Ando, *l H. Baba,*l K. Demichi,* l

ZS. Fulop,*3 U. Futakami,* l H. Hasegawa,* l Y. Higurashi ,* l K. Ieki,*l N. Imai,*2 N. Iwasa,*4 H. Iwasaki,*5
T. Kubo, S. Kubono ,*5 M. Kunibu,*l Y. U. Matsuyama,* l S. Michimasa,*5 T. Minemura, H. Murakami,*lT. Nakamura,*6 A. Saito,*l H. Sakurai,*2 M. Serata,*l S. Shimoura,*5 T. Sugimoto,*6 E. Takeshita,*lS. Takeuchi,* l K. Ue,*5 K. Yamada,d Y. Yanagisawa, A. Yoshida, and M. Ishihara[NUCLEAR REACTIONS: 208Pbe 3AI ,p 22 Mg)208Pb , 50 AMeV; Coulomb dissociation]
We performed an experimental study of thestellar 22Mg(p ,1' )23 Al reaction using the Coulombdissociation method. This reaction is relevant to the
nucleosynthesis of 22Na in Ne-rich novae.1- 3) The firstexcited state of 23 AI, lying at 405 keY above the proton threshold,3) is located near the Gamow energy fornovae. Therefore, the 22Mg(p ,1')23 Al reaction in therp-process could be dominated by resonant capture
through the first excited state. In .the present study
we aimed at making a determination of the radiation
width (f, ) of the first excited state in 23AI.
The experiment was performed at the RIPS beamline. A radioactive beam of 23 Al was produced by the
projectile fragmentation reaction of a 28Si beam on a
9Be target. A beam of 23 Al at 50 MeV /nucleon bombarded a 88 mg/cm 2 208Pb target. The products of the
breakup reaction, 22Mg and a proton, were detected,
respectively, by a silicon t elescope and a plastic scintillator hodoscope located 56 cm and 4 m downstream of
the target. A stack of sixty-eight NaI(TI) scintillators
was placed around the target to measure deexcitationl'-rays when 22Mg is excited to a bound state. The
details can be found in Ref. 4.
To select the breakup events through the first excited state in 23 AI, and also to reduce the contributions of higher excited states, we analyzed the data
under the condition that the opening angle between
22Mg and a proton is smaller than go. Under thiscoincidence condition, the time-of-flight (TOF) distribution of the breakup protons is shown in Fig. 1.
The observed peaks gave a trace of the resonantstate excitation. Figure 2 shows a Doppler-correctedl'-ray spectrum obtained under the same condition.
As shown in this figure, we observed deexcitationl'-rays corresponding to the 2+ ---7 0+ transition of
22Mg. This indicates a considerable contribution of
the process 23 Al ---7 23 Al *(E x ~ 2 MeV) ---7 p +22Mg*(2+ ; E x = 1.246 MeV) , which should be subtracted to extract the breakup cross section of interest.
From the TOF distribution of protons , we obtained
*1

*2
*3
*4
*5

*6

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

C)

~ 20
~

~
o 15

~

!l 10
~

;::l

8 5
o~~~~~~~~~~

20

30

40

50

60

70

TOF [nsec]

Fig. 1. TOF distribution of the breakup protons obtained
under the condition that the opening angle between
22Mg and a proton is smaller than 9° . When the p22Mg relative energy is 405 keY, it is estimated that the
TOF of protons ranges from 38 to 48 nsec.

1000

2000

3000

Ky [keY]

Fig. 2. Doppler-corrected i-ray spectrum in coincidencewith breakup events. The 2+ ---7 0+ transition of 22Mg
can be seen.

a rough estimate of the cross section of the Coulombdissociation reaction through the first excited state of
23 Al to be 4 mb. Supposing that the spin and parity of
23 Al is 5/2+ for the ground state and 1/2+ for the firstexcited state, the cross section corresponds to f, ~ 6 X
10- 7 eV, which is compatible with the value predicted
by J. A. Caggiano et al. 3 )References
1) H. Herndl et al.: Phys. Rev. C 52, 1078 (1995).
2) H. Schatz et al.: Phys. Rev. Lett. 79, 3845 (1997).
3) J. A. Caggiano et al.: Phys. Rev. C 64, 025802 (2001).
4) T. Gomi et al.: RIKEN Accel. Prog. Rep. 34, 73 (2001).

69

RIKEN Accel. Prog. Rep . 35 (2002)

Coulomb excitation of 24Si
S. Kanno,*1 T. Gomi,*1 T. Motobayashi,*1 K. Yoneda, N. Aoi,*2 Y. Ando,*1 H. Baba *1 K. Demichi *1
Zs. Fulop,*3 U. Futakami,*1 H. Hasegawa,*1 Y. Higurashi,*1 K. Ieki,*1 N. Imai,*2 N. Iw~sa,*4 H. Iwas~ki,*5
T. Kubo, S. Kubono,*5 M. Kunibu ,* 1 Y.U. Matsuyama,*1 S. Michimasa,*5 T. Minemura, H. Murakami, *1
T. Nakamura,*6 A. Saito,*1 H. Sakurai,*2 M. Serata,*1 S. Shimoura,*5 T. Sugimoto,*6 E. Takeshita,* 1
S. Takeuchi, *1 K. Ue,*5 K. Yamada,*1 Y. Yanagisawa, A. Yoshida, and M. Ishihara

The coulomb excitation of a very proton-rich nucleus, 24Si, to its 2+ state was studied using a radioactive beam of 24Si at 57.9 MeV /nucleon bombarding a
208Pb target . The nucleus, 24Si, was produced by using
projectile fragmentation of a 28Si primary beam on a
9Be production target. The fragments were collected
and analyzed by RIPS. The extracted 24Si intensity
was typically 3.2 x 103 S-1. Particle identification of thesecondary beam was carried out event-by-event using
the time-of-flight (TOF) information between the cyclotron RF and a plastic scintillator with 500 p,m thickness set at the second focal point of RIPS. A 208Pb
target of 56.8 mg/cm 2 thickness was placed at the focal
point of RIPS, and used to excite the projectiles. The
position and incident angles of the beam at the target
were measured by two sets of parallel-plate avalanche
counters (PPAC) placed at third focal point (F3).
Scattered 24Si nuclei were detected by a counter
telescope placed 60 cm from the target in a vacuum.
The telescope consisted of four layers of eight ionimplanted silicon detectors of 50 x 50 cm 2 effective areaand 500 p,m thickness. The particles of interest were
mostly stopped in the last layer. An isotopic identification of scattered particles was achieved by the flE- E
method. A good resolving power of the detector telescope enabled us to distinguish 24Si from other reaction
products with Z = 8- 14.
Sixty-eight NaI(TI) scintillators surrounded the target to detect ')'-rays. Each scintillator crystal was ofrectangular shape with a size 6 x 6 x 12 cm 3. The energy and efficiency calibration of each NaI(TI) crystal
was made by using standard 22Na, 60Co , 88y, 137Cs
sources. The high granularity of the setup allowed us
to measure the angle of the ')'-ray emission , which was
useful in correcting large Doppler shifts of the ')' raysfrom the excited 24Si, that was moving with v / c ~ 0.3.

*1 Rikkyo University
*2
*3

*4
*5
*6

70

University of TokyoATOMKI , Hungary
Tohoku University
Center for Nuclear Study, University of Tokyo
Tokyo Institute of Technology

60

2+ ~ 0+
If)

40

-+-l

~

;j
0

u 20

1000

2000

3000

E")' [keV]
Fig. 1. The de-excitation , ray.

Excitation to the 2+ state was identified by measuring the ')'-ray de-excitation of the 2+ state in coincidence with the scattered 24Si ions. Figure 1 shows
the ')'-ray energy spectrum associated with the 24Si
+208Pb inelastic scattering. It was obtained by summing the spectra for all of the NaI(TI) scintillators
after· a Doppler-shift correction. The accidental coincidence yield was subtracted from the energy spectrum by using data obtained by setting a gate at theregion beside the true-coincidence peak in the 24Si_,
time-difference spectrum. As can be clearly seen in
the figure , only one full-energy peak was observed at
1.89 MeV 1) corresponding to the 2+ ~ 0+ transition.
Further analysis to extract the B(E2) value is now inprogress.
References
1) H . Schatz et al.: Phys. Rev. Lett. 20 , 79 (1997).

RIKEN Accel. Prog. Rep. 35 (2002)

Study of the first excited state
in a very neutron-rich nucleus, 30Ne
Y. Yanagisawa, M. Notani,*1 H. Sakurai,*2 S. Shimoura,*1 H. Iwasaki,*1 S. Michimasa,*1 K. Ue,*1
M. Kurokawa,*1 N. Iwasa,*3 M. Kunibu,*4 H. Baba,*4 T. Gomi,*4 A. Saito,*4 T. Minemura,Y. U. Matsuyama,*4 H. Higurashi,*4 S. Kanno,*4 M. Serata,*4 E. Takeshita,*4 S. Takeuchi, *4
K. Yamada,*4 K. Demichi,*4 H. Hasegawa,*4 H. Akiyoshi, N. Fukuda, K. Yoneda, N. Aoi,*2
N. Imai,*2 T. Sugimoto,*5 T . Nakamura,*5 and T. Motobayashi*4

An interesting aspect of the region around N = 20
nuclei is the transition from spherical to deformed
shapes in the so-called 'island of inversion. '1) We report on the first energy measurement of the 2i excited state in a very neutron-rich nucleus, 30Ne, with
N = 20.
In-beam, spectroscopy using radioactive beams has
been carried out by some methods in recent years.
We have performed proton inelastic scattering witha liquid-hydrogen target by detecting de-excitation,-rays in coincidence with scattered particles. Thismethod takes advantage of its high experimental efficiency, because the useful target thickness of liquid hydrogen is one or two orders thicker than that of othermethods. The method can be now applied to very
neutron-rich nuclei even with a beam intensity on theorder of 0.1 counts per second.
An experiment was performed at RIPS. A primary
40 Ar beam of 94 MeV/nucleon with a typical intensityof 60 pnA bombarded a natTa target with a thickness of
666 mg/cm 2. To maximize the beam intensity of 30Ne,
the experiment was operated with a full-momentum
acceptance of 6%. Particle identification of the secondary beam was performed by a standard method
based on the energy loss (~E), time-of-flight (TOF)
and magnetic rigidity (Bp)2) for separating 29Ne and
30Ne beams. The positions of the fragments at the
momentum-dispersive focal plane (F1) were recodedusing a parallel-plate avalanche counter (PPAC) in order to determine the Bp values. The TOF of eachfragment was measured from timing singals of a plastic scintillator placed at F2 and RF signals of the cyclotron. Two silicon detectors were located in frontof the final focal plane (F3) for measuring the energy
loss. The 30Ne beam was obtained to be 0.2 cps witha contamination of 29Ne, 31 Na and 32Na beams.
The 30Ne beams impinged on a liquid-hydrogen target 3) with a thickness of 180 mg/cm 2, which was placed
at F3 to excite the projectiles. Scattered particles weredetected and identified by a PPAC and a silicon tele*1

*2

*3
*4

*5

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

scope located about 50 cm downstream of the target.
The identification of Z was obtained by the TOF-~E
method. DALI with sixty-eight NaI(TI) scintillators
was placed around the target to detect the de-excited, rays emitted from excited fragments.
Figure 1 (a) and (b) show a preliminary result of theenergy spectra of , rays with a doppler-shift correction. They were obtained by 29Ne and 30Ne beams
in coincidence with the fragments of Ne isotopes, respectively. In Fig. 1 (a), , lines at around 440, 600,
and 1300 keY can be observed, whereas the, line at
790 ke V can clearly be observed in Fig. 1 (b), except for
the ,line in Fig. 1 (a). Note that the spectra show the, ray from 28Ne, 1320 keY. Compared to both spectra, the, rays at 790(30) keY were assigned to be the2+ --+ 0+ transition associated with 30Ne + p inelastic
scattering. Also, the remaining two peaks in Fig. 1 (a)may be from the fragments of 29Ne. A further analysis
is now in progress.
12
10
8

6

:>
Q)
~

0

4
2

~

'-...

0

...,

20

Cfl

>=l

;:j
0

U

15
10
5

500

1000

1500

Energy[keV]

Fig. 1. Doppler-corrected energy spectra of -y-rays obtainedin coincidence with 29Ne(l(a)) and 30Ne(l(b)) beams
and fragments of Ne isotopes.

References
1) E. K. Warburton et al.: Phys. Rev. C 41, 1147 (1990).
2) H. Sakurai et al.: Phys. Lett. B 448, 180 (1999).
3) H. Akiyoshi et al.: RIKEN. Accel. Prog. Rep. 32, 167(1999).

71

RIKEN Accel. Prog . Rep. 35 (2002)

Proton inelastic scattering by 32Mg
H. Hasegawa,*l T. Motobayashi, *l M. Kunibu ,* l Y. Yanagisawa, T. Nakamura,*2 M. Notani, *3 T. Gomi, *lT. Sugimoto,*2 H. Baba,*l A. Saito,*l Y. Mizoi, s. Kannno,*l H. Iwasaki,*3 E. Takeshita,* l K. Demichi,*ls. Michimasa,*3 K. Ue,*3 N. Fukuda, N. Iwasa,*4 M . Kurokawa,*3 S. Shimoura,*3 H. Sakurai,*4 and M. Ishihara[Proton inelastic scattering, nuclear deformation]
A sudden disappearance of the N = 20 shell closure
was suggested for the very neutron-rich nucleus 32Mg
based on the low excitation energy (885 ke V) of its first2+ state,1 ,2) and an enhanced B(E2) of 454 ± 78 e 2fm 4
was obtained in the 0+ --7 2+ Coulomb excitation. 3)
The present study is aimed at investigating a possible difference between the amounts of proton- andneutron-deformations for 32Mg by measuring the proton inelastic scattering, hoping that more detailed information would become possible on the nuclear structure.
The experiment was carried out at RIPS. Primarybeams of 40 Ar with a energy of 93.6 MeV / nucleon bombarded a 641 mg/cm 2 thick 181Ta target. Radioactive
32Mg beams with a energy of 59.6 MeV /nucleon wereextracted by the RIPS. The secondary beams contained 3% of 34 AI, 28% of 30Na and small amounts ofother nuclides as well as 32Mg with a fraction of 68%.
The beams bombarded a liquid-hydrogen target 4) witha thickness of 180 mg/cm 2, contained in a cooled cellwith windows made of 6.6 J.Lm havar foils. The overall beam-target luminosity was obtained by measuring
event-by-event the hit position of the beam on the target using position information provided from two setsof parallel-plate avalanche counters (PPACs) set upstream of the target. The averaged energy of 32Mg in
the middle of the target was 49.5 MeV /nucleon. The
reaction products were measured by a counter telescope placed 48 cm from the target. The telescope consisted of three identical ion-implanted silicon detectorsof 50 x 50 mm 2 effective · area and 500 J.Lm thickness.
The particles reaching the third detector were rejectedin the analysis. The scattering angle was measured
by a parallel-plate avalanche counter (PPAC) placedin front of the silicon detectors. The /,-ray deexcitation was measured in coincidence with the inelastically scattered 32Mg ions. A DALI setup consisting offifty-four identical NaI(TI) scintillators was positioned
around the target for /,-ray detection. The typical energy resolution of each 12-cm-length and 6 x 6-cm 2area scintillator was 9.1% for the 662 keY /,-ray. The
Doppler shift was corrected for by the detector angle
with respect to the beam direction.
Particle identification for magnesium ions was performed by the function atlE(E + ktlE)b, which was*1

Rikkyo Unive rsity*2 Tokyo Institute of Technology*3 Center for Nuclear Study, University of Tokyo*4 University of Tokyo72

proposed by Stokes, Northrop and Boyer 5 ) using signals from the first and second silicon detectors. Parameters k and b were adjusted so as to achieve the bestisotope separation, whereas a is an arbitrary constant.
The resultant width, 0.8 (FWHM), is a measure of themass resolution of the present measurement. Figure 1
shows the Doppler-corrected spectra of ,),-rays measured in coincidence with 32Mg. In the spectrum two
peaks have been identified. One at 0.9 MeV is due tothe transition from the first excited 2+ state at 895 ke V
to the groupd state in 32Mg. Considering the present
isotopic resolution, a peak seen at around 1.5 MeV isattributed to a transition in 32Mg. This energy may coincide with that of the peak (1430 keY) observed in the
fragmentation experiments at GANIL 6 ) and RIKEN,7)
where /'-')' correlation data indicate that the peak corresponds to a transition to the 2+ state from a higher
state, the spin of which is not established. An analysis
is now in progress.
120

885keV100:>Q).!:s::

80"""+>rn

60

;:l
0
U

40

!

0
C'J

~

1430keV

!

20
0

0

500

1000

1500

2000

Energy (keV)

2500

3000

Fig. 1. Doppler-corrected spectrum of ,-rays in coincidencewith 32Mg, produced by proton inelastic scattering by
32Mg.

References
1) C. Detraz et al.: Phys. Rev. C 19, 164 (1979).
2) D. Guillemaud-Miiller et al.: Nucl. Phys. A 426, 37(1984).
3) T. Motobayashi et al.: Phys. Lett. B 346, 9 (1995).
4) H. Akiyoshi et al.: RIKEN Accel. Prog. Rep. 32 , 167(1999).
5) R. H. Stokes, J. A. Northrop, and K. Boyer: Rev. Sci.
Instr. 29 , 61 (1958).
6) F. Azaiez et al.: AlP Conf. Proc. 481, 243 (1998).
7) K. Yoneda et al.: Phys. Lett. B 499 , 233 (2001).

RIKEN Accel. Prog. Rep . 35 (2002)

Large collectivity of 34Mgt
H. Iwasaki,*l T. Motobayashi,*2 H. Sakurai,*3 K. Yoneda, T. Gomi,*2 N. Aoi,*3 N. Fukuda, Z. Fulop,*4
U. Futakami,*2 Z. Gacsi, *4 Y. Higurashi ,*2 N. Imai,*3 N. Iwasa, *5 T. Kubo, M. Kunibu ,*2 M. Kurokawa, *l
Z. Liu,*6 T. Minemura, A. Saito,*2 M. Serata,*2 S. Shimoura,*l S. Takeuchi,*2 Y. X. Watanabe , K. Yamada, *2
Y. Yanagisawa, and M. Ishihara
NUCLEAR REACTIONS: Pb , Ce 4Mg,34Mg')'), 44.9 MeV/nucleon, Coulomb excitation, De-][ duced B(E2)
Experimental evidence for deformed nuclei in theso-called 'island of inversion ,' l) centered at Z
11and N
21 , was first obtained by a mass measurement ,2) which revealed that the neutron-rich 31,3 2 Na
isotopes are more tight ly bound than predicted theoretically. In this region, the most convincing evidence
for an anomalous deformation has been obtained in the
N = 20 nucleus 32Mg from the low E(2i) of 886 keV 3)
and the large B(E2) 4) of 454(78) e 2fm 4 as well as anenhancement of the binding energy.5) Currently, greatinterest is focused on investigating more neutron-richnuclei beyond N = 20 to elucidate how the anomaly
evolves across the region of the island.
Here, we report on the first measurement of
B(E2; 0i-s. -----t 2i) for the very neutron-rich nucleus
34Mg with N = 22, which was performed with theintermediate-energy Coulomb excitation method. 6) Avery large value of the measured B(E2), together withthe low E(2i),7) indicates that the deformation of
34Mg is even larger than in t he classical case of 32Mg.
The experiment was performed at the RIPS facility 8) in RIKEN.
A secondary 34Mg beam at
44.9 MeV /nucleon bombarded a 693 mg/cm 2 -thick Pbtarget. The typical intensity of the 34Mg beam was 4
counts per second. Scattered particles were detected
and identified by an array of silicon detectors. By using a granular array of 66 Nal(TI) detectors , we measured de-excitation')' rays in coincidence with the scattered particles. Angle-integrated cross sections wereobtained from the observed ')'-ray yields . Data werealso taken with a 339 mg/cm 2-thick C target to evaluate nuclear excitation contributions. The details of theexperimental arrangement are described elsewhere.9 )Figure 1 shows the Doppler-corrected ')'-ray energy
spectrum obtained from 34Mg + Pb scattering. In
the spectrum, a single dominant peak stands out at
656(7) keV. Since the intermediate-energy Coulomb
excitation selectively excites the 2i state of an eveneven nucleus, we conclude that the')' transition corresponds to de-excitation of the first excited 2i state of

60

f'V

f'V

*1

*2

*3
*4

*5

*6

Condensed from the article in Phys. Lett. B 522 , 227 (2001)
Center for Nuclear Study, University of Tokyo
Rikkyo University
University of TokyoATOMKI, Hunga ry
Tohoku University
Institute of Modern Physics , China

656(7) keV
2+ 1-+0+ g.s.

:>

~

a.>

~

0

...,j<...........

40

PbC4Mg,34 Mg -y)Pb

Cf.l

E-<

Z

~

0

u

E=44.9 MeV/nucleon

20

500

1000

1500

2000

E.y [keY]

Fig. 1. Doppler-corrected ,-ray energy spectrum obtainedin the inelastic scattering of 34Mg at 44.9 MeV/nucleon
with a Pb target.

34Mg located at 656(7) keV.
An experimental deformation parameter ((32 ) of0.58(6) was deduced through an ECIS calculation by
searching for the (32 value which best reproduces themeasured cross section of 286(52) mb. The error in(32 includes both experimental uncertainties and theoretical ambiguities regarding the choice of optical potentials and the nuclear contribution. We then obtain B(E2 ; 0i-s . -----t 2i) = 631(126) e2fm 4 , which is thelargest among the E2 strengths observed for nuclei inthe vicinity of the island of inversion. The very large
B(E2) value, corresponding to a quadrupole deformation parameter of (32 ~ 0.6, strongly indicates that
34Mg is a well-deformed nucleus.
References
1) E. K. Warburton et al.: Phys. Rev. C 41 , 1147 (1990).
2) C. Thibault et al.: Phys. Rev. C 12 , 644 (1975).
3) C. Detraz et al.: Phys. Rev. C 19, 164 (1979); D.
Guillemaud-Mueller et al.: Nucl. Phys. A 426 , 37
(1984) .
4) T. Motobayashi et al.: Phys. Lett. B 346, 9 (1995).
5) C. Detraz et al.: Nuel. Phys. A 394, 378 (1983).
6) T. Glasmacher: Ann. Rev. Nuel. Part. Sci. 48, 1 (1998).
7) K. Yoneda et al.: Phys. Lett. B 499 , 233 (2001).
8) T. Kubo et al.: Nuel. Instrum. Methods Phys. Res. B
70 , 309 (1992).
9) H. Iwasaki et al.: Phys. Lett. B 522, 227 (2001).

73

RIKEN Accel. Prog. Rep . 35 (2002)

Spectroscopy of 34Si with inelastic deuteron scattering
N. Iwasa,*l T. Motobayashi,*2 H. Sakurai,*3 H. Akiyoshi, Y. Ando,*2 N. Aoi,*3 H. Baba,*l N. Fukuda,*3
Zs. Fulop,*4 U. Futakami,*2 T. Gomi,*2 Y. Higurashi, K. Ieki,*2 H. Iwasaki ,*3 T. Kubo, S. Kubono,*5
H. Kinugawa,*2 H. Kumagai, M. Kunibu,*2 S. Michimasa,*5 T. Minemura,*2 H. Murakami,*2
A. Saito,*2 S. Shimoura,*5 S. Takeuchi,*2 Y. Yanagisawa, K. Yoneda, and M. Ishihara

Excited states in 34Si were studied by measuring deexcitation , rays in coincidence with 34Si ion produced
by deuteron inelastic scattering in reversed kinematics.
A radioactive ion beam of 34Si produced in the
fragmentation reaction of a primary 40 Ar beam in aberyllium target and separated by the RIKEN projectile fragment separator (RIPS) bombarded a liquiddeuterium target. The reaction products were analyzed by four silicon counter telescopes arranged in a
2 x 2 matrix. The de-excitation ,-rays were detectedby a NaI(TI) array consisting of 68 NaI(TI) crystals
surrounding the target from 40 to 138 degrees in coincidence with 34Si detected by the silicon telescopes.
A lead shield with a thickness of 5 cm surrounded theNaI(TI) array for background reduction.
Figure 1 (a) and (b) show the de-excitation, spectra
for the 2He 4Si, 34 Si ,) reaction in the projectile andlaboratory frames , respectively. Nine, lines at 591,
930, 1010, 1193, 1435, 1715, 1941, 2696 and 3328 keY
were observed in the projectile frame, whereas a 511ke V line was observed in the laboratory frame. Thelines at 1010 and 1941 ke V are known to be from
33Si and 32Si, respectively, and the lines at 930 and
3328keV are from 34Si.l) Recently, Nummela et al. discovered lines at 591, 1193, 1715 and 2696 keY by their;3-delayed , measurements, but they were not placedin the decay schemes, except for the 591-ke V line.2)
The solid curve in Fig. 1 (a) represents a fit with these
gamma lines. The line shape (dashed curve) of eachtransition was calculated by Monte-Carlo simulations .
An additional, line at 2300 keY and an exponential
background (dotted curve) were necessary to fit the
spectrum.
The above assignments of the gamma lines have been
confirmed by a careful analysis using particle identification from the silicon telescope obtained by the D.E-E
method . Exceptions are the 1435 and 2300 ke V lines.
The 2300-ke V line was not reported in previous papers. 1- 3) The 1435-keV line was tentatively assigned
as a (~-) - 7 (~+) transition of 33Si by Fornal et al.,3)
however, our analysis favors assigning the line to be

*1

*2
*3
*4
*5

74

Tohoku University
Rikkyo University
University of TokyoATOMKI , Hungary
Center for Nuclear Study, University of Tokyo

Sn=7.536(C)- -----r--

2000

6024

4000

E.):keV]

(b)

+. -

e e
o

2000

4000

E.):keV]Fig. 1. / spectra in (a) the projectile frame and (b) thelaboratory frame in coincidence with 34Si detected by
the silicon counter telescope. (c) Decay scheme of 34Si.

from 34Si.
In order to construct a decay scheme, , -, coincidence data were analyzed . The lines at 591, 930, 1193,
1715 and 2696 keY were observed in coincidence withthat at 3328 keY. The 930-keV line was not observedwith the 1193-, 1715- and 2696-keV ,lines. Fromthese facts, the 1193-, 1715- and 2696-keV lines aretentatively assigned to the transitions from states at4518 keY, 5043 keY and 6024 keY to the 2+ state, as
indicated by the dashed lines in Fig. 1 (c) .
References
1) R . B. Firestone et al.: Table of Isotopes, 8th ed. , (AWiley-Interscience Publication, New York, 1998).
2) S. Nummela et al.: Phys. Rev. C 63 , 044316 (2001).
3) B . Fornal et al.: Phys. Rev . C 49, 2413 (1994).

RIKEN Accel. Prog. Rep. 35 (2002)

Production cross sections of neutron rich N == 50 nuclei in
66 A MeV 86Kr-induced reactions
N. Aoi ,*1 A. Kobayakawa,*1 T. Matsuura,*1 H. Sakurai,*1 N. Imai ,*1 Y . Ando,*2 H. Baba,*2 K. Demichi,*2
U. Futakami,*2 T. Gomi,*2 H. Hasegawa, *2 Y. Higurashi ,*2 K. Ieki ,*2 H. Ikeda, *3 N. Iwasa,*4 H. Iwasaki,*1
S. Kanno,*2 T. Kubo , M. Kunibu ,*2 M. Kurokawa,*3 Z. Liu,*5 Y. U. Matsuyama,*2 S. Michimasa,*6
T. Minemura,*2 M. Miura,*3 T. Motobayashi,*2 H. Murakami,*2 T. Nakamura,*3 M. Notani,*6 Q. Pan,*5
A. Saito,*2 M. Serata,*2 S. Shimoura, *6 T. Sugimoto,*3 E. Takeshita, *2 S. Takeuchi,*2 K. Ue,*6
K. Yamada,*2 Y. Yanagisawa, K. Yoneda, X. Zhou ,*5 and M. Ishihara
NUCLEAR REACTIONS: 9Be(86Kr,X), E(86Kr) = 66 A MeV; Measured production cross][sections of 80 Zn , 8I Ga, 82Ge, and 83 As
The fragmentation reaction of 86Kr is profitable in
the production of neutron-rich nuclei lying along thenutron magic number 50 towards the doubly magic nucleus, 78Ni. In this work, we measured the production
cross sections of neutron-rich N = 50 nuclei in the fragmentation of 66 A MeV 86 Kr, which allowed us to makea reliable estimation of the secondary-beam intensities
available with RIPS. The obtained results were compared with the cross sections of the same reactions at
higher energy (500 A MeV)1) as well as the production
cross sections in the in-flight fission rection. 2)
A primary beam of 86 Kr was accelerated by the AVF
and RING Cyclotrons and bombarded a 97mg/cm 2
thick Be target at 66 A MeV. The typical beam intensity was 0.5 pnA. Projectile-like fragments were collected and analyzed by RIPS. The angular acceptanceof RIPS was set at the maximum value of 5 msr. The
momentum acceptance was defined using a slit at F1
and was set at 0.5%.
The fragments were transported to the final focal
plane (F3) and detected by a parallel-plate avalanche
counter (PPAC) and four layers of Si detectors (0.5 mm
thick) located behind the PPAC. The PPAC provided
detection timing and the positions of fragments. The
time-of-flight (TOF) between the production target
and F3 was determined from the time difference between the PPAC and the RF signal of the accelerator.
Particle identification was made by measuring themagnetic rigidity (B p) , time-of-flight (TO F), and energy deposit in the second and third Si detectors (!:lEand E). The atomic number was determined from thecorrelation between the TOF and !:lE. E information
was incorporated for the determination of A.
Differential cross sections were measured with eight
Bp settings ranging from 2.74 Tm to 2.83 Tm. The
cross sections were determined from a fit of the

*1
*2
*3
*4
*5
*6

observed momentum distribution to an asymmetric
Gaussian. The collection efficiency was corrected forbased on the angular acceptance calculated by the
INTENSITY code.
The obtained production cross sections are shownin Fig. 1 together with the results concerning the fragmentation of 86 Kr at 500 A MeV 1) and that of the inflight fission of uranium. 2) The present result agrees
well with that at 500 A MeV, while they are about twoorders of magnitude smaller than the in-flight fission
reaction cross sections. The prediction by EPAX2 3)(solid line) gives almost consistent values in this region , but the slope is less steep than the observed value.
A simple exponential extrapolation (dashed line) gives.--.. . 10- 12 barn for the production cross section of 78Ni.

"
a

\0 2

-

oj

.a
~

.
~

'2
M
10°

- --

.

thi, work
GSI 500J.II.V
GSI (/i ..lon)
EPAXZ
htrapolaUonc::3

10 - 2

U

,f

Q)

til
til
til

0

...U

10-·

10- 8

8.

78

A

Fig. 1. Production cross sections of N = 50 isotones as afunction of the atomic numbers.

References
1) M. Weber et al.: Nucl. Phys. A 578, 659 (1994).
2) M. Bernas: AlP Conf. Proc. 455, 664 (1998).
3) K. Siimmerer et al.: Phys. Rev. C 61, 034607 (2000).

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

75

RIKEN Accel. Prog. Rep. 35 (2002)

Coulomb excitation of 84Se
N. Aoi,*l N. Imai,*l Y. Ando,*2 H. Baba,*2 K. Demichi, *2 U. Futakami,*2 T. Gomi,*2 H. Hasegawa,*2
Y . Higurashi ,*2 K. Ieki,*2 H. Ikeda,*3 N. Iwasa,*4 H. Iwasaki ,*l S. Kanno,*2 A. Kobayakawa,*l T. Kubo,
M. Kunibu,*2 M. Kurokawa,*3 Z. Liu,*5 T. Matsuura,*l Y. U. Matsuyama,*2 S. Michimasa,*6 T. Minemura,*2
M. Miura,*3 T. Motobayashi,*2 H. Murakami,*2 T. Nakamura,*3 M. Notani,*6 Q. Pan,*5 A. Saito,*2
H. Sakurai,*l M. Serata,*2 S. Shimoura,*6 T. Sugimoto,*3 E. Takeshita,*2 S. Takeuchi,*2 K. Ue,*6
K. Yamada,*2 Y. Yanagisawa, K. Yoneda, X. Zhou ,*5 and M . Ishihara[NUCLEAR REACTION: Pb(84Se,84Swy), Coulomb excitaion]
Unstable nuclei around the N = 50 neutron magic
number have drawn our interest from the point of viewof both nuclear structure and nucleosynthesis . However, experimental information was limited, mainly
due to difficulties in the secondary-beam production.
In this work, a neutron-rich N = 50 nucleus, 84Se, wasstudied through a Coulomb excitation measurement.
The 84 Se beam was produced at RIPS l ) using the
projectile fragmentation reaction of 86Kr. The primary beam of 86Kr was accelerated by the AVF and
RING Cyclotrons and bombarded a 97 mg/cm 2 thick
Be target at 66 A MeV. The typical beam intensity was
0.5 pnA. The width of the momentum slit at F1 was
set at 1%. A flat Al plate (instead of a wedge-shapedone) was used for the energy degrader at F1, and areasonably small beam spot size of 12 mm (FWHM)
was obtained at F3 thanks to the narrow momentum
acceptance. An isotope purity of 83% was achieved
with an intensity of about 5 kcps.
The 84Se beam irradiated a 226 mg/cm 2 thick Pbtarget. The energy of the 84 Se beam was 38.6 A Me V at
the middle of the target. The position and incident angle of the secondary beam was measured with two setsof parallel-plate avalanche counters (PPAC's) locatedupstream of the secondary target. Scattered particles
were detected by a PPAC and a Si telescope locatedabout 50 cm downstream from the secondary target
covering a scattering angle of up to about 6 degrees in
the laboratory frame. This PPAC was used for determining the scattering angle of the outgoing particles.
The Si telescope consisted of two layers, each of which
had four Si detectors placed in a two-by-two matrix.
The size of each detector was 5 cm x 5 cm x 325 p,m.
The Si telescope provided flE-E information , which
was used to identify the atomic number (Z) of theoutgoing particle.
The de-excitation , -rays were detected with DALI ,which consisted of 68 NaI(Tl) scintillators. The energyof the observed , -ray was corrected for the Doppler
shift based on the position of the scintillator which
*1
*2
*3
*4

*5

*6

76

University of Tokyo
Rikkyo University .
Tokyo Institute of Technology
Tohoku University
Institute of Modern Physics, China
Center for Nuclear Study, University of Tokyodetected the , -ray.
Figure 1 shows the Doppler shift-corrected , -rayspectrum observed in coincidence with the outgoing selenium (Z = 34) isotopes. The , -ray peaks at 1455 keY
and 667keV are ascribed to the transitions between
known states in 84Se2): the transition from the firstexcited state (J 7r = 2+, Ex = 1455 keY) to the groundstate and that from the 2122 ke V state (tentatively 1-)
to the first excited state. Besides these , -ray lines ,several peaks are seen in the spectrum, such as thosearound 1 MeV, 1.3 MeV and 1.8 MeV. Assignments ofthe transitions to these lines were not made. Further
analysis, including a determination of the transition
strength and establishment of the transition assignments, is in progress.

84 Se :(1-)-+2+

,~

3000

>Q)

,

0

.....

....

~I

W\

~

"'-.....
I=:

84 Se : 2 + ->0+

2000

\

;j

t~

I

1000

11

11

~

0
U

'1

\trI;.J

~

\

500

1000

1500

2000

2500

3000

"I-ray Energy [keV]

Fig. 1. Doppler shift-corrected ),-ray spectrum observed incoincidence with the outgoing selenium.

References
1) T. Kubo et al.: Nucl. lnstrum. Methods Phys. Res. B
70 , 309 (1992).
2) R. B. Firestone et al.: Tables of Isotopes (Wiley, New
York, 1996), p. 491.

RIKEN Accel. Prog. Rep. 35 (2002)

g-Factor of a high-spin isomer in 149Dy
H. Watanabe, H. Veno, W. Sato, A. Yoshimi, D. Kameda,*l T. Kishida, Y. Kobayashi, H. Miyoshi,*lA. Odahara,*2 Y. Gono,*3 and K. Asahi[NUCLEAR REACTION 24Mg(132Xe,7n)149mDy, E = 7MeV /nucleon; measured ,(8, B, t)]Many isomeric states have been observed in nuclei
near the semi-doubly magic nucleus 146Gd (Z = 64,
N = 82). These isomers are mainly produced whenthe valence particles around the 146Gd core align on
the symmetry axis . Such a feature is most likely
maintained even at a higher spin state. That is why
high-spin isomers could be observed in N = 83 isotones with atomic numbers from 60 to 68. The excitation energies and half-lives of these high-spin isomers were systematically studied in detail. 1) However,
the g-factor and quadrupole moment have been measured only in the high-spin isomer of 147 Gd so far. The
configuration and deformation parameter ((3) of thisisomer were deduced from these experimental quantities to be [v(!7j2hg/2i13j2)7r(hi1 j2 )l;9 j22) and -0.19,3)
respectively. A deformed independent particle model(DIPM)4) well reproduces the characteristics of a highspin isomer in 147 Gd. According to this calculation,
high-spin isomer in 149Dy, whose excitation energy andhalf-life are 8.52 MeV and 28 ns,5) respectively, is expected to have the same configuration and deformation as that in 147 Gd. In this work, therefore, we attempted to measure the g-factor of the high-spin isomer in 149Dy in order to check the validity of this calculation.
Figure 1 shows a schematic diagram of the experimental setup. The high-spin isomer in 149Dy was prod uced and aligned via an inverse kinematic fusion re-

Pb stopper

3500 .-~---r--r--~-..--~---r--r--~---,

3000

5~50

1000

1050

11 00

1150

1200

1250

1300

1350

1400

1450

Energy [ke Vl

Fig. 2. ,-ray singles spectrum measured by a Ge detector.
Gamma rays emitted from 149m Dy are indicated by the
diamonds.

action, 24Mge32Xe,7n)149mDy, with a pulsed beam of
132Xe accelerated up to an energy of 7 MeV /nucleon
by the RIKEN Ring Cyclotron. The beam repetition
time was selected to be 1 /-lS. The recoil nuclei were
stopped on a lead foil placed 7 em downstream froma magnesium target. An external magnetic field of
l.5 T was applied to the stopper perpendicularly toboth the beam axis and the detection plane. The
space between the target and the stopper was filledwith Ar gas to retain alignment of the recoil nuclei
during the flight. It took about 4 ns to pass throughthe Ar gas region. This recoil- into-gas technique allows us to measure only , rays emitted via an isomericstate (t1 /2 2: 1 ns) by enclosing a production target
with lead shields. Gamma rays from the stopper position were measured with four Ge detectors locatedat ±45°, ± 135° . A , -ray singles spectrum obtained inthis experiment is shown in Fig. 2. The g-factor is extracted from the ratio of the , -ray intensities , R(t) =[1(8, t) - 1( -8 , t)]j[1(8 , t) + 1( -8, t)], where 1(8, t) indicates the normalized and background-corrected yieldof r ray deexciting the isomeric state. An analysis of
the experimental data is now in progress.
References

Fig. 1. Schematic drawing of the experimental setup.
*1

*2
*3

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

1) A. Odahara et al. : Nucl. Phys. A 620 , 363 (1997) , andreferences therein.
2) O. Hausser et al.: Phys. Rev. Lett. 42 , 1451 (1979).
3) O. Hausser et al.: Nucl. Phys. A 443, 135 (1985).
4) T. Dossing et al.: Phys. Scr. 24 , 258 (1981).
5) T. Fukuchi: Master Thesis, Kyushu University (1999).

77

RIKEN Accel. Prog. Rep. 35 (2002)

Study of PHENIX Electron Trigger
T. Matsumoto,*1 H. Hamagaki ,*1 K . Oyama,*1 K. Ozawa, *1 T. Sakaguchi,*1 S. Kametani,*2
J. Kikuchi,*2 M. Tamai,*1 and Y. Tanaka,*3[Quark Gluon Plasma, High Energy Heavy Ion Collisions, PHENIX, RHIC]
One of the major goals of the PHENIX experimentis to investigate the property of new states of matter
through electron and electron-pair measurements. 1,2)
The Electron Trigger using a Ring Imaging Cherenkov(RICH) detector and an ElectroMagnetic Calorimeter(EMCal) is dedicated to this purpose. At RHIC, thedesigned luminosity is 1.4 x 1031 cm- 2sec- 1 in p + p at
VB = 500 GeV and 6.0 x 10 26 cm- 2sec- 1 in Au + Au
at J S N N = 200 Ge V . The reaction rate with theseluminosities is 12 MHz in p+p and 1.2 kHz in Au +Au. Since the Data Collection Module (DCM) has amaximum bandwidth of 25 kHz, a rejection factor of
approximately 500 (12 MHz/25 kHz) is needed in theextreme case of p + p collisions.
As a first level hardware trigger , the PHENIX LVL-1
trigger system decides whether to accept the data or
not from the detector subsystem's LVL-1 signals within
40 Bunch Crossing (BC) after an event. The Electron Trigger is constructed from the RICH and EMCal
LVL-1 signals.
The PHENIX detector complex has two central arms
and two muon arms. Both RICH and EMCal are located in the central arms. The RICH is one of the major devices for electron identification. The Cherenkov
photons generated by electrons, positrons, and highmomentum hadrons are reflected by spherical mirrors
and detected by 5120 PMT arrays. The RICH LVL-1
signal is generated when the analog sum of 20 PMT's(4(¢) x 5(z)) output exceeds a trigger threshold. The
primary information from EMCal is the energy andspatial position of photons and electrons. One arm
comprises four sectors of lead-scintillator (PbSc) modules, the other has two sectors of PbSc and two of
lead-glass (PbGl). The EMCal LVL-1 signal is generated when the deposited energy in 4 towers exceeds athreshold value. The Electron Trigger uses the matrix
coincidence between 256 bits of RICH LVL-1 signal and172 bits of EMCal LVL-1 signal.
The study of an Electron Trigger consisted of twostages. First, the trigger algorithm, efficiency and rejection power were studied by simulations. The 60 k
single J / 'IjJ ---t e + e - events, 54 k single ¢ ---t e + eevents and 200 k minimum-bias events of p + p, Si + Si,
,>1

*2

*3

78

Center for Nuclear Study, Graduate School of Science, University of Tokyo
Advanced Research Institute for Science and Engineering,
Waseda University
Nagasaki Institute of Applied Science

Ag + Ag and Au + Au were used. The results were described briefly in the CNS annual report 1999. 3) Mainconclusion was that the RICH threshold should be 3
photo-electrons per trigger-tile under the condition of
CO 2 radiator gas, and the EMCal energy thresholdshould be 0.9 GeV for the J /'IjJ trigger and 0.3 GeV forthe ¢ trigger. The RICH LVL-1 hardware was developed based on this study.4) The trigger algorithm wasthen applied to real data and trigger performance was
evaluated. This is the main topic described in thisreport .
From the obtained data, 593000 events of Au + Au
full-field data at JSNN = 130 GeV were used in thisstudy. The electrons from the collision points, whichwere off center by 30 cm in the z direction, didn 't reach
the EMCal surface because of the pole pieces of thecentral magnet. Thus the absolute value of the zvertex reconstructed by Beam-Beam Counters (BBC)within 30 cm was required in these event samples.
Table 1 gives the centrality class and corresponding
number of binary collisions as well as the number ofparticipants in a event .
Events were sorted into 6 centrality classes, as listed
in the table. These classes were derived from the combination of Zero Degree Calorimeters (ZDC) and BBC.
The number of participants was calculated using a
Glauber model. The number of participants in mostperipheral events was around 5. These event samples
are useful to evaluate the electron trigger performancefor a p + P run.
Figure 1 shows the single electron trigger efficiency
for RICH as a function of the trigger threshold, which
has units of photo-electoron in a trigger-tile.
This simulation result shows that the trigger efficiency is almost 100% when the threshold level is below 3 photo-electrons, and declines with an increase in
the threshold level. The RI CH threshold was fixed toTable 1. Centrality classes of a Au + Au event.

I Centrality I Binary Collisions I Participants I
0-5%
5 - 15%15 - 30%
30 - 60%
60 - 80%
80 - 92%945 ± 141673 ± 100383 ± 57
123 ± 18
19 ± 113.7 ± 2.2

347 ± 52271 ± 41178 ± 2776 ± 1119 ± 11
5±3

~
c::

1

~

---.,:

E

---

~ 0.9
~ 0.8

&

'i

~

UJ

"1~

¥

...,~

QI

CD

""'-.,

0.6

~

~

,

Ii
'

,: i

,

....

1:1

' Ii

0)

~ 0.7

!,

0.4

Z

i,

E
1
....

i

0.2

:
;, :

O. 1

:

0.3

"

5

6

7

8

Fig. 1. Simulated trigger efficiency as a function of numberof photo-electrons in a trigger tile.

.8E

::>

'0

~

~o

I Trigger
Total Event
RICH Hit (3 photo-electron)
EMCal Hit (0.3 GeV)
EMCal Hit (0.9 GeV)
RICH and EMCal (0.3 GeV)
RICH and EMCal (0.9 GeV)

I Count I Ratio I
593000376418310725142288160132
74428

63 %
52%
24%
27%
13%

.....

i:
:
"- ... "\
"'
,
'\

'i.

,

D-

~

,

C

o

U
QI
a::

Table 2. Survival rate under various trigger conditions.

...

-I\.

:'

"jj)

3 photo-electrons from the simulation result.
Table 2 shows the summary of trigger rate under thevarious conditions for the last Au + Au run. Rejection
powers of around 3 (0.3 GeV) and around 8 (0.9 GeV)
were achieved. Here, the rejection power is defined by
the number of total events divided by the number oftriggered events.
Figure 2 shows the rejection power as a functionof the centrality classes , which are described in Table 1. The closed circles are for the case when the EMCal energy threshold was set to 0 GeV (corresponds
to RICH only trigger) , the open square shows the ¢trigger (0.3 GeV) and the closed square shows the J / 'I/J
trigger (0.9 GeV) , respectively. Since matrix coincidence hardware will not be ready, complete look-up(256 bits + 172 bits) can not be done in an upcoming
run. Because a feasible way is half sector matching(16 bits + 16 bits) , this matching was used as the coincidence method in this study.
The rejection power clearly moves upward as thecentrality goes down in Au + Au collision. In the mostc·· :, ;+, ,
1....

\.

I.;'\.

4

i

1

···i

:J

RICH Threshold {Photo Electronffrigger Tile]

i

z

.8

3

. ..... ;....

j'
i

~'0

0.5

2

i ....

,

1

1

,

'"
10

....

\

, 1

... ....

, ....

\

, ..

~II

\.

[',

i ~··~
h···l~·'-

10

2

Number of Participants

Fig. 2. The rejection power as a function of centrality.
The closed circle shows RICH only trigger, open squareshows ¢ trigger (EMCal threshold = 0.3 Ge V) andclosed square shows J /7./J trigger (EMCal threshold =0.9 GeV).

central case, the rejection power is approximately 1.5.
At 80- 92% centrality, rej ections of 23( ¢ trigger) and95 (J /'I/J trigger) were achieved . Although these results are not directly applicable to the coming p + P
events , simple extrapolation to the p + P case (numberof participants = 2) provides a rejection factor larger
than 200 in the J / 'I/J trigger case.
An Electron trigger algorithm has been developed
and applied to PHENIX real data. It is expected thata good rejection power to reduce the trigger rate down
to the level of DAQ capability will be achieved in an
upcoming p + P run.
References
1) PHENIX Conceptual Design Report , BNL (1993) (unpublished).
2) PHENIX Collaboration : Nucl. Phys. A 638 , 565c
(1998) .
3) T . Matsumoto et al.: C NS-REP-25 , July (2000), p. 23 .
4) T. Matsumot o et al.: C NS-REP-25 , Oct. (1998) , p. 25.

79

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of the 8Li( a,n)llB reaction cross section
with 8Li beams below 1.5 MeV In energy
M. Kurata-Nishimura, S. Nishimura, Y. Nishi, M. A. Famiano, 1. Tanihata, P. vValden,*1 P. Amaudruz,*1
R. PoutissOU,*1 J. 1. PoutissOU,*1 L. Buchmann,* 1 R. N. Boyd,*2 1. Sahin,*3 A. Murphy,*2 and B. Fulton*4[Nucleosynthesis, Inhomogeneous Big Bang models]
We have performed measurements of the cross section for the 8Li( a,n) 11 B reaction with a 8Li beam with
0.6 MeV In energy at the TRIUMF cyclotron of the
ISAC facility. This reaction is considered to be crucial
to predict the light-element abundances from big-bang
nucleosynthesis. 1)
Although some previous experiments were made to
determine this reaction cross section,2- 4) they were
not even in qualitative agreement with each other.
Measurements of the low-energy cross section, below 1 MeV In, which are important for predicting theabundances of light elements by inhomogeneous bigbang models of nucleosynthesis (IBBN), have not beenmeasured yet due to difficulty of handling low-energy
beams.
The Isotope Separator and Accelerator (ISAC)
which was constructed at TRIUMF (Canada) recently,
consists of two systems. One is a target assembly where
many different isotopes can be produced by bombarding various elements with 500 MeV protons beam fromthe TRIUMF cyclotron. The other device, a Radio
Frequency Quadrupole (RFQ), is used as the first stepfor increasing the energy of the isotopes extracted fromthe target. By using this facility, singly charged ion
beams consisting of isotopes whose mass is less than 30
atomic mass units can be accelerated . Moreover, theISAC facility at TRIUMF is designed to provide theworld's most intense beams of accelerated radioactive
isotopes for a wide range of experimental programs.
ISAC employs the ISOL (Isotope Separation On-Line)technique, where short-lived isotopes are continuously
produced, ionized and transported as a focused beam.
Hence , the most important reactions involved in the
chains of nuclear reactions occurring in explosive astrophysical sites become available for study.
For determining the 8Li( a , n) 11 B reaction cross section , t he neutron production rate is measured. Neutrons are emitted from 0 degree to 180 degrees in thelaboratory system. The identification of neutrons canbe done by measuring the energy and emission polar
angle, since the incident energy of a 8Li beam is well
fixed and momentum of the 4He gas is negligible. Because of the high beam intensity (more than 1 x 10 7
particles per sec.), any kind of beam counter is not use*1
*2
*3
*4

80

TRIUMF Cyclotron Laboratory, Canada
Ohio State University, USA
Oak Ridge National Laboratory, USA
University of York, USA

ful to be operated under such a high-current condition.
We have installed 3 neutron counter walls which consist of 16 plastic scintillator slats with 2 PMT's in the
ISAC experimental hall. The neutron counter has dimensions of 6 x 6 x 108 cm 3 and two PMT's (Hamamatsu H6410) are attached to the ends of the plastic scintillator. The neutron walls are placed at 1.6 m
away from the center of a He gas target by taking into
account the time-of-flight separation of neutrons emitted from the ground state of 11 B and ones emitted fromthe first excited state of 11 B . The neutron walls cover
the polar angle from 21 degrees to 140 degrees witharound a 6% geometrical acceptance.
The signal from the PMT's is divided into two lines:
one is used for a timing measurement after discrimination; the other is used for a charge measurement . The
hit position on the counter is determined by the t ime
difference between both side PMT 's and also the ratio of the integrated charge from them. The energy ofa neutron is determined by the time-of-flight methodby measuring the time difference between the neutron
counter signal as a start and the cyclotron-RF clock
timing as a common stop.
Sixteen signal lines from 8 counters are fed into
one discriminator module (CAMAC 3412), where thethreshold and width are adjusted to 50 m V and 80 ns,
respectively. The sum output from this discriminatoris reshaped at the level indicating 2 of any 16 PMT's
firing , and is then used in the trigger logic.
In order to trigger events indicating that 11 B or
any charged particles scattered in a target, a target
cell which includes 5 small pieces of plastic scintillators read by a multi-anode PMT (HAMAMATSU
R5900L16) is installed in the vacuum chamber. The
entrance and exit windows of the target cell are closedwith Ni foil less than 250 nm in thickness to allow 8Li
beams to pass through it. 4He gas is filled in the cellat pressures of 20 to 25 torr .
Three trigger settings are employed in this experiment. The first one, called the single trigger, requires
one of the neutron counters to fire. The second one,called the double trigger, requires two of the neutron
counters to fire within a 200 ns interval, covering slow
neutrons. This double trigger makes it possible to require adjacent hits of scattered neutrons in the counter.
The third one requires a single trigger OR double trigger AND that the target cell counter fires.
The beam spot was well-tuned at the target entrancewindow with a size of less than 3 mm¢>. Although an
intensity of 1.8 x 10 7 particles per sec was achieved
with a beam energy of 0.6 MeV In, it was 1 order ofmagnitude less than what we expected.
The analysis is still progressing. At this moment,
no clear neutron peak has been observed in any trigger
settings. The reason is due to a considerable amount of
gamma-ray background from the target area. As longas we survey the radiation around the target, almost
70% of the beam seems to be stopped at the exit window area. This value is much worse than we estimatedin a simulation. We believe that the main componentof background is gamma rays related to the beta decay of 8Li stopped at the target window area, and thatthe rest is the room background. Surely the separationof gamma signals .from the neutron signal is essential.
This result will be used to improve the experimental
setup for the next run.
References
1) M. J. Balbes et al.: Phys. Rev. Lett. 71, 3931 (1993).
2) X. Gu et al.: Phys. Lett. B 343, 31 (1995).
3) R. N. Boyd et al.: Phys. Rev. Lett. 68 , 1283 (1992).
4) Y. Mizoi et al. : Phys. Rev. C 62, 065801 (2000).

81RIKEN Accel. Prog. Rep. 35 (2002)

Indication of a reduced chiral order parameter from the Is 7r
states in 205Pb and light nuclei
H. Geissel,*1 H. Gilg,*2 A. Gillitzer,*3R. S. Hayano,*4 S. Hirenzaki, *5 K. Itahashi ,*6 M. Iwasaki,*6 P. Kienle,*2
M. Miinch,*2 G. Miinzenberg,*1 W . Schott,*2 K. Suzuki,*4 D. Tomono,*6 H . Weick,*1 ·T. Yamazaki, andT. Yoneyama*6[pion, pionic states, chiral symmetry]
It is of great importance to study the s-wave (local)
part of the pion-nucleus interaction, as emphasized recently,l,2) since not only the s-wave strength as a whole

R _ b,'rOOIb,
0.6

0.7

0.8

0.9

1.0

I

I

I

I

I

:

1

O :

+SM

L_ 0 Battytranslates into a pion mass excess in a nuclear medium,but also its isovector parameter (bd is related to thepion decay constant (fn). The isoscalar bo (including the density-quadratic term) and isovector bi parameters of the s-wave pion-nucleus interaction in the
Ericson-Ericson potential were deduced to beb~ = -0.029 ± 0.0013 m;l,bi = -0.116 ± 0.018 m;l,by using the binding energies and widths of the Is nstates in both light pionic atoms and the deeply boundn- state in 205Pb,3) in which a neutron skin effect 4) istaken into account (see Fig. 1) . The enhanced isovector
strength, Ibll , over the free-nN value (-0.090) infers
that the squared chiral order parameter is reduced in
the nuclear medium by
*2

bfree

fn

1

f = _1_ = 0 78 +0.14
R = ~
2
b
. -0.12'Fig. 1. Presentation of the isoscalar (be) and the isovector (bI) parameters in units of m;l . The Is states oflight symmetric pionic atoms give a shaded horizontal band. The bo - bi constraint by the Is state of
205Pb with a neutron skin effect is shown by anothershaded band with 10' error lines. The be - bi constraint without a neutron skin effect is shown by thebroken line. The double-scattering effect,5) when bi
is modified in the nuclear medium, is shown by threedotted curves corresponding to different nuclear densities of 0.155 , 0.165 and 0.175fm- 3 . The free-nN values("FREE") and their effective values ("EFF") after the
double scattering corrections are also indicated. The
scale for the reduction of the squared chiral order parameter, R = biree /b i ~ 1;2/ f:', is indicated in the upper part. Various potential parameters obtained fromthe global fitting of pionic atom data are also shown.

*1

Gesellschaft fur Schwerionenforschung, Germany*2 Physik-Department, Technische Universitat Munchen, Germany*3 Institut fur Kernphysik , Forschungszentrum Julich, Ger*4

*5
*6

82

many
Department of Physics, University of Tokyo
Department of Physics, Nara Women's University
Department of Physics, Tokyo Institute of Technology

This is in accordance with Weise's prediction, R rv
0.65, as an indication of a partial restoration of chiralsymmetry breaking.2)
The isoscalar part is accounted for as arising froma double-scattering effect, without invoking a large Re
Bop(r)2 term.
References
1) P. Kienle and T. Yamazaki: Phys . Lett. B 514, 1 (2001).
2) W. Weise: Acta Phys . Pol. 31 , 2715 (2000) .
3) H. Geissel et al.: Phys. Rev. Lett., in press.
4) A. Trzcinska et al.: Phys. Rev. Lett. 87, 082501 (2001).
5) N. Kaiser and W. Weise: Phys. Lett. B 512 , 283 (2001) .

2. Atomic and Solid-State Physics

RIKEN Accel. Prog. Rep. 35 (2002)

Bound states of a positron with molecules
M. Tachikawa, 1. Shimamura, R. J. Buenker,*l and M. Kimura*2
It is now known that in electron (e -)-polar molecule
systems, an infinite number of stable electron boundstates can be formed in the Born-Oppenheimer approximation if the polar molecule has a dipole moment larger than Dc = 1. 625 De bye (D).1) This is aconsequence of a long-range dipole interaction, behaving as ~r-2 at large r , regardless of the nature of
the short-range interactions. Even if the dipole moment is smaller than Dc, or there is no dipole moment at all, the formation of bound states around amolecule may still be possible, though their number
should be finite. Indeed , these considerations have furnished basic knowledge about electron attachment topolar molecules, and have also been found to be usefulfor a systematic understanding of low-energy electron
scattering by molecules.
These theoretical considerations do not depend on
the sign of the dipole interaction. Therefore, we expectthat a positron (e +) has an infinite number of boundstates around a stationary polar molecule whose dipole
moment exceeds Dc = 1.625 D at the equilibrium nuclear position, although the spatial distribution of thepositron can be expected to be opposite to that of an
attached electron. These considerations have not been
fully appreciated in studies of possible positron attachment to molecules.
Possible positron binding states with atoms havebeen studied theoretically,2) and two important mechanisms of electron binding to atoms have been proposed: (i) a positron forms a positronium within an

atom, and (ii) a positron can be trapped on the tail of along-range polarization potential. For molecular cases,
there have been some theoretical attempts 3- 5 ) to investigate a possible formation of positron bound states
based on the Hartree-Fock, quantum Monte Carlo andother approaches .
We have investigated a number of different moleculesfrom non-polar to strongly polar molecules. By using
the HF method with the inclusion of higher order corrections, we have confirmed that, indeed, OH- ionscan maintain a bound state with a positron. We havefound that the electron cloud on the H atom shifts
toward the 0 atom because of the higher electronegativity of the 0 atom. Next , we added a positron to
the OH- ion, and found that p orbitals in the 0 atom
stretch out toward the positron, and are significantly
deformed. This is because the positron is more attracted by a negative charge centered on the 0 atom,
and is eventually captured by it.
References
1) W. R. Garrett: J. Chern. Phys. 73, 5721 (1980).
2) G. Ryzhikh, J. Mitroy, and K. Varga: J. Phys. B 31 ,3965 (1998).
3) H. A. Kurtz and K. D. Jordan: J. Chern . Phys. 75, 1876
(1981) .
4) D. Bressanini, M . Mella, and G. Morosi: J. Chern. Phys.
109 , 1716 (1998).
5) M. Tachikawa, K. Mori , K. Suzuki, and K. Iguchi: Int.
J. Quantum. Chern. 70, 491 (1998).

* 1 Theoretische
C hemie,
Bergische
U niversitatGesamthochschule Wuppertal, Germany*2 Graduate School of Science and Engineering, Yamaguchi
University

83

RIKEN Accel. Prog. Rep . 35 (2002)

Diabatic ionization model for capture of antiprotons by atoms
Y. Teranishi and 1. Shimamura
Collision processes involving an antiproton have attracted much attention recently, since the Antiproton Decelerator (AD) facility at CERN is expected
to open new possibilities for related experiments. 1)
Even though the capture of antiprotons by atoms or
molecules is one of the most important processes in analyzing these experiments, accurate theoretical calculations are available only for the simplest target, i. e.,
the hydrogen atom. 2 ) In the present study, we propose a simple, diabatic ionization model for the capture cross sections for atomic targets in general, anddiscuss its validity by comparing with other theoreticalresults.
In our model, we assume that the target atom (A)is ionized with unit probability when, and only when,
an antiproton (p), following the classical trajectory,
reaches a critical distance (Rc) from the target nucleus, at which point the diabatic ionization potential
becomes zero. In other words, Rc satisfies the equationture + ionization) cross sections for He and Ne atoms
are shown in Figs. 1 and 2 and are compared with theresults of classical-trajectory Monte Carlo (CTMC)
calculations. 3 ,4) As shown in these figures, our results
agree well with the CTMC results.
100~--~----~--------~----,

§

~

(/)
(/)
(/)

e<.>

10

rnI

co

~

II
I

1 iL--__-----',---____-L,_ _ _ _ _ _ _ _ _ _" - -_ __o(1)where vatom(R) and vion(R) are diabatic potentials of
the antiproton-atom system p -A and of the antiprotonion system p-A +, respectively, defined byvatom(R) =< Watom I Vatom - p(R) I watom >,

(2)

0.2

0.4

0.6

0.8

Energy (a. u. )Fig. 1. Total cross sections for He. The solid line indicatesthe present calculation, and the open square the CTMC
calculation.

and

100 ~
i ----~--~----~----~---,(3)
We assume that the antiproton is captured by theatom if ionization occurs at collision energies E below
the ionization threshold. The capture cross section isthen given by

(4)

c
0

~

(/)

(/)
(/)

e<.>
co

~

where !J.E == vatoffi(Rc) - Vatoffi(oo). If we make afurther assumption that the angular momentum of theemitted electron is negligible , the cross section differential in the continuous classical angular momentum lof the formed antiprotonic atom pA + is given byd(7 = 27r_l_dl
2/-1E'(5)

where /-1 is the reduced mass of pA + . The maximum
angular momentum is given by(6)
The parameters R c and !J.E were calculated for various atomic targets with atomic numbers Z = 1- 54 using the Hartree-Fock wave functions. The total (cap-

84

10

1I
0

0.2

0.4

0.6

0.8

Energy (a.u. )Fig. 2. Total cross sections for Ne. The solid line indicatesthe present calculation, and the open square CTMC
calculation.

References
1) Y. Yamazaki: AlP Conf. Series 498, 48 (1999) .
2) K. Sakimoto: Phys. Rev. A 65 , 012706 (2002).
3) J. S. Cohen: Phys. Rev. A 56 , 3583 (1997).
4) J. S. Cohen: Phys. Rev. A 59 , 1160 (1999).

RIKEN Accel. Prog. Rep. 35 (2002)

Tunneling effect in the single ionization of N e byan intense laser field
Y. Teranishi and 1. Shimamura
The study of atoms and molecules in intense laser
fields has grown over the last decade. Developmentsin the laser technology have led to short-pulse lasers
with field strengths on the order of one atomic unit.
Ionization of atoms and molecules by such a strong
field takes place due to tunneling ionization or overthe-barrier ionization.
Feeler and Olson 1 ) studied the single ionization of Ne
by using the classical Monte-Carlo method to obtainthe momentum distribution of Ne+ after ionization by
800 nm lasers with various intensities of from 3 x 10 14 to
3 X 10 15 W /cm 2 . In this intensity regime, the Keldysh
parameter (,), defined by_J2EI '
OW,-

where Xl and X2 are the turning points, p(x) is the momentum of the electron parallel to the laser polarization, and the contour of the integration is also parallelto the laser polarization. Our results for a wavelengthof 800 nm and an intensity of I = 1.3 X 10 15 W /cm 2with and without the tunneling effect, are shown in
Fig. 1 along with the experimental results given in
Ref. 3. Our results show that the tunneling effect plays
an important role in the ionization process even when
the Keldysh parameter is smaller than unity (, = 0.245
in this case). The tunneling effect sharpens the momentum distribution because the pulse width is solarge that the ionization is completed before the intensity reaches its peak value.

2(1)
0.5 ,---- --where Eo, w , and I are the ionization potential of thetarget , the frequency of the laser field, and the intensity of the laser field , respectively, is smaller than unity(0.775 to 0.245) , which may imply that over-the-barrier
ionization plays a dominant role, and that classicalmechanics can describe the ionization process. Theircalculation, however , gives a rather broad momentum
distribution of Ne+ compared to the experimental results. In the present study, the momentum distributionof Ne+ was calculated by the classical Monte-Carlo
method including the tunneling effect. The role of tunneling in the ionization process was considered.
In order to treat a multi-electron target in the classical mechanical framework , we considered only one active electron subjected to the model potential proposed
by Garvey et al. 2) The initial condition for the electronis given by the micro canonical ensemble. Hamilton's
equations were solved by the Runge-Kutta method,
and when the electron reaches the potential barrier,the tunneling probability was calculated assuming onedimensional motion along the direction of the laser polarization, namely,- - - - - --

--

0.4
-::;
c

::J

0.3

.e

~

I

x

0.2 1

0....

:e

!

'U

0.1

o==~

-4

______ ____

-3

-2

-1

0

2

3

~

4

Px (a.u. )Fig. 1. Momentum distribution of the Ne+ ion after ionization by an 800 nm, I = 1.3 X 10 15 W /cm 2 laser.
The solid line indicates the present calculation, and thedashed line represents CTMC without tunneling effect.
The solid squares indicate the experimental values.

Referencesp=1
1 + exp(27rlcrl)(2)Here, cr is defined by
cr=

l

X2

p(x)dx,(3)1) C. R. Feeler and R. E. Olson: J. Phys. B 33, 1997
(2000) .
2) R. H. Garvey, C. H. Jackman, and A. E. S. Green: Phys.
Rev. A 12, 1144 (1975).
3) R. E. Olson, J. Pascale, and R. Hoekstra: J. Phys. B
25 , 4241 (1992) .

Xl

85

RIKEN Accel. Prog. Rep. 35 (2002)

Theoretical intensity distributions of K X-ray
satellite spectra emitted from Al
T. Yamamoto
Theoretical calculations were carried out to reproduce the fine structures of the K X-ray satellite spectraof Al induced by the impact of C 3+ ions. These satellites are emitted from KLn multiple ionized states, i.e.,
excited states with one K and n L vacancies. Relative
intensities of the satellites emitted from KL n multiple
ionized states are proportional to KL n multiple ionization cross sections , if we assume that the fluorescence
yields for all multiple ionized states are the same. The
KLn multiple ionization probability P K Ln is expressedby a binomial equation as

Pw =L [G) p,s'(l- P, s)2-,]a ,b2s a(l - P2S )2-a]

X [(:) PX [(~) P2p b (l - P2P )6-b] ,where PIs , P 2s and P 2p are the ionization probabilities of Is, 2s and 2p electrons, respectively. The Binary Encounter Approximation (BEA)l) and the SemiClassical Approximation (SCA)2) are often employed
to calculate the multiple ionization cross section, andare useful for light projectiles such as protons and alpha particles. However, large discrepancies appear between experiments and calculations for heavier projectiles carrying orbital electrons when we use thesemethods. Because the projectiles are treated as bareparticles, i. e., particles with no orbital electrons, theionization cross section is proportional to Z 1 2 in thesemethods , where Zl is the atomic number of the projectile. Then, we employed the Geometrical Model,3 ,4)which is a modification of BEA, in order to obtain
KL n multiple ionization cross sections. This method
is applicable under the condition , vp » v e , where vp
and V e are velocities of the projectile and the L electrons, respectively, and hydrogenic wave functions are
employed for the electrons in the target atom . In thismethod , the charge state of the projectile is assumed
to be an effective charge instead of ZI. Details of theGeometrical Model are found in the references. 3) The
multiple ionization cross section due to the shake process is not negligible for a target with a low-Z number. The shake probabilities 5 ) were also taken into
account in these calculations. Calculated results for
the K-alpha X-ray spectra of Al induced by C 3+ ionswith incident energies of 18.5, 23.6, 40.3 and 72.3 MeV
are compared with experimental results 6 ) in Fig. 1,
in which theoretical intensity distributions reproduced

86d) 72.3MeV

o 123 4 5
Number of L vacancies
Fig. 1. Comparisons of Al K-alpha X-ray satellite distributions induced by a) 18.5, b) 23.6, c) 40.3, and d)
72.3 MeV C 3 + ions between experiments and calculations. Solid bars represent experiments, and shaded
and open bars represent calculations with and without
the shake effect, respectively.

the experimental ones well. From these results, our calculation method was found to be useful for analysis of
the satellite structures induced by heavy ion impacts,
where conventional methods failed.
References
1) J. D. Garcia: Phys. Rev. A 1, 280 (1970).
2) J. M. Hansteen and O. P. Mosebekk: Nucl. Phys. A
210, 541 (1973).
3) B. Sulik et al.: J. Phys. B 17, 3239 (1984).
4) B. Sulik et al.: Nucl. Instrum. Methods Phys. Res. B
28, 509 (1987).
5) T. Mukoyama and K. Taniguchi: Phys. Rev. A 36 , 693(1987).
6) R. L. Watson et al.: Phys. Rev. A 19, 1529 (1979).

RIKEN Accel. Prog. Rep. 35 (2002)

Studies on electron degradation and thermalization
In H2 and D2 gases
K. Kowari*
The relaxation of subexcitation electrons in H2 gas
at a temperature of 300 K and the number density of
2.69 x 10 19 cm- 3 has been studied by Kowari using
the Boltzmann equation. 1) The Boltzmann equation,
which explicitly includes elastic and inelastic collisions ,is given by

8f

at = Jel(f) + Jin(f),(1)

where f = f(v , t) , and v is the velocity of an electron. In Eq. (1) , Jel(f) and Jin(f) are the elastic
and inelastic collision operators, respectively. The
elastic collision operator is the Fokker-Planck operator, and the inelastic collision operator a difference
operator.
The expansion of the electron velocity
distribution function in Legendre polynomials gives
00

f(v,t)=

1: fl(V,t)Pl(cos()).

We assume that thel=Oelectron distribution function is spatially homogeneousand isotropic in v. The electron energy distributionfunction is expressed as p(E, t) = 27r(~)~ .JEf(v , t),m; ,2where E =and the incremental degradation
spectrum as z(E, t) = vp(E, t). Inserting p and z
in Eq. (1), we obtain the equation for time evolution of z(E, t). We solve it with an initial distribution
Po = <5(E - Eo)<5(t), where Eo is an electron initial energy. Once we have obtained the electron distributionfunction p(E, t), we can calculate the electron averageenergy, the cumulative degradation spectrum, the cumulative net yields, and so on.
It deepens our understanding of electron degradation and thermalization in gases to carry out a study
on isotope effects in D2 and H2 gases. We have recently
carried out calculations for electron degradation andthermalization in D2 gas with three different electron
initial energies and complementary calculations in H 2,
in order to study isotope effects. 2) Suppose nlm is thenumber of collisions that excite a molecular state l tom, the net cumulative yield is calculated aswhere m is greater than l. Figure 1 shows cumulative
net yields for major rotational-excitation processes in
H2 and D 2. The net yield for J = 1 to 3 is the largest
in H2 because of the statistical weight, and that for
J = 2 to 4 in D 2. All net yields shown in Fig. 1 seemto reach a plateau by 6 ns.
It is shown that the electron average energy in H2 decreases more rapidly than that in D2 until some 5.5 ns,
and thereafter it decreases more slowly.2) Furthermore,
University of Electro-Communications

Fig. 1. The solid curves represent net yields for primaryrotational excitations with an initial energy of 5 eV in
H2 , and the dashed curves those in D 2 . The symbol
nJ=02 indicates the net yield for J = 0 to 2, nJ=13 for
J = 1 to 3, nJ=24 for J = 2 to 4, and nJ=35 for J = 3
to 5.
the influence of collisions casuing rotational excitationand deexcitation on the electron average energy after
6 ns is discussed for H2 and D 2·
I have given an analysis of the electron average energies in H2 and D2 with multi-term exponential fitting
by means of a fitting algorithm I have developed. 3 ) The
paper compares the calculated exponents with experimental results by Warman and Sauer 4) and by Okigaki
et at. 5)
In a series of papers l - 3 ) electron attachment is notincluded, and this is considered to be justified as the
cross section for electron attachment in H2 is muchsmaller than those for the other processes involved;
however, it is reported that if H2 molecules are vibrationally or rotationally excited, a peak at 4 eV isstrongly enhanced. 6 ) Since the present method can include electron attachment,7) we will be able to study
the negative-ion formation in H2 and D2 at high temperature if adequate information on the cross sections
for electron attachment is given.
References
1) K. Kowari: Phys. Rev. A 53 , 853 (1996).
2) K. Kowari: in preparation.
3) K. Kowari: Radiat. Phys. Chern. (2002) , in press.
4) J. M. Warman and M. C. Sauer, Jr.: J. Chern. Phys.
62 , 1971 (1975).
5) S. Okigaki, E. Suzuki, K. Hayashi, K. Kurashige, and
Y. Hatano: J. Chern. Phys. 96 , 8324 (1992).
6) H. Tawara, Y. Itikawa, H. Nishimura, and M. Yoshino:
J. Phys. Chern. Ref. Data 19, 617 (1990).
7) K. Kowari, Ki Leung, and B. D. Shizgal: J. Chern. Phys.
108, 1587 (1998) .

87

RIKEN Accel. Prog. Rep. 35 (2002)

Elastic-wave source characterization for
95 MeV lu Ar-ion irradiation on solids
T. Kambara, Y. Kanai, T. M. Kojima, Y. Nakai, Y. Yamazaki, A. Yoneda, and K. Kageyama*
We have observed elastic waves generated by irradiation of 95 MeV lu Ar ions on various solids, and measured the propagation time of the elastic wave in thematter to determine the depth of the wave source.
The experiments were performed at the RIKEN
Ring Cyclotron with a 95 MeV l u Ar beam which consisted of a single-bunch pulse with a width of 3 ns andan interval of about 60 ms. The beam preparation,
monitoring and irradiation setups were similar to thosefor the previous experiments. 1 ,2)The irradiated samples were polycrystalline metals(AI and Cu), single-crystalline alkali-halides (LiF and
KCI), polycrystalline A1 2 0 3, fused silica (Si0 2 ) , andan invar alloy. The samples were square-shaped plateswith similar dimensions of about 40 mm x 40 mm x
10 mm except for the Cu plate which was 35 mm x
35 mm x 10 mm. The beam spot size was about
4 mm x 4 mm and the beam was incident perpendicularly on the square-shaped surface (face plane). Two
KCI samples were used with different surface orientations of {100} and {Ill}. The velocities of the longitudinal and shear waves in the samples were measured
by a sing-around method.
The elastic wave was detected by piezoelectric sensors (Fuji Ceramics, M304A).3) The sensor is equippedwith a head amplifier and is sensitive to oscillation perpendicular to the surface up to about 2 MHz with thehighest sensitivity at about 300 kHz. Two sensors wereattached to a sample: one , referred to hereafter as theside sensor, was on a side plane, and the other, referred to as the back sensor, was at the center of theback plane opposite the face plane where the beam hit.
Figure 1 shows the waveforms measured by the backsensor for various samples. The waveform is averaged
over 40- 50 shots to reduce the noise, and normalized
to the same number (about 9 x 10 3) of ions. The axisof the sensor was about 1.5 mm from the beam center.
This distance was smaller than the diameter of thesensor and the beam spot size, therefore the shortest
distance from the beam spot to the sensor was equal
to the sample thickness. Since the sensor can detect
the oscillations perpendicular to the surface and was
positioned nearly opposite the beam spot , it detected
only the longitudinal wave (compression wave).
Two of the materials, invar and fused silica, yieldedmuch lower amplitudes than the others, as shown in
Fig. 1 (b). These two materials have very low coefficients of thermal expansion. The results indicate that

Department of Mechanical Engineering, Saitama University

88

Elastic wavefonn at back sensor

~0.02

(b)

:::I

C.

8 0
o

!0.02 Fused Silica-0.04Time (J,ls)0Time (J,ls)

Fig. 1. Elastic waveforms captured by a sensor attachedto the surface opposite the beam spot. The waveforms
are normalized to the beam-bunch intensity; (b) shows
those for fused silica, invar and Ab03 where the ordinate is expanded by a factor of 10.

the process that generates the longitudinal wave (compression wave) is influenced by the thermal expansionof the material. The results for invar and fused silica
are not included in the following discussions.
We have measured the delay between the irradiationand the onset of the elastic wave. From the delay time,
we have obtained the depth of the wave source fromthe beam spot. The depths are in accordance with, butslightly smaller than , the ranges calculated by a TRIM
code 4) with a relative difference of 3- 10%. There is nodifference between the two crystal orientations of KCl.
Both the back and side sensors detected the longitudinal wave with a positive output voltage at the onset which corresponds to an outward displacement of
the surfaces. This result means that the stress at thesource is compressive and propagates in all directions.
References
1) T. Kambara, Y. Kanai, T. M. Kojima, Y. Nakai, A.
Yoneda, K. Kageyama, and Y. Yamazaki: Nucl. Instrum. Methods Phys. Res. B 164/165, 415 (2000).
2) T. Kambara, Y. Kanai, T. M. Kojima, Y. Nakai , A.
Yoneda, Y. Yamazaki, and K. Kageyama: AlP Conf.
Proc. 576, 1040 (2001).
3) M. Shiwa, H. Inaba, and T. Kishi: J. JSNDI 39, 374(1990) .

4) J. F. Ziegler, J. P. Biersack, and U. Littmark: The Stopping and Range of Ions in Solids (Pergamon Press, New
York, 1985).

RIKEN Accel. Prog. Rep. 35 (2002)

Anomalous shift of the Curie temperature in Fe-Ni Invar alloys
irradiated with high-energy ions
F. Ono,*l A. Iwase,*2 Y. Hamatani, *l Y. Motoshimizu,*l N. Ishikawa,*2
Y. Chimi,*2 Y. Mukumoto ,*l and T. Kambara
Fe-Ni Invar alloys are known to exhibit various
anomalies in both mechanical and magnetic properties. 1) Anomalies in the thermal expansion coefficientwere interpreted as being due to the large positive
value of the magnetovolume effect which cancels out
the normal part of the thermal expansion. Anomalous decrease in the spontaneous magnetization fromthe Slater-Pauling curve was considered to be due tothe instability of the ferromagnetic condition of the
3d-electrons. 2 ) It is also known that Fe-Ni Invar alloys show anomalously large pressure dependence at
the Curie temperature , Te , and under the spontaneous
magnetization. 3- 5) The Curie temperatures of Fe-Ni
Invar alloys around the composition of 33.6 at%Ni werereported to decrease with pressure at a large rate of-36 K/GPa. Therefore, high-energy ion irradiation is
expected to introduce a large change in T e .
The effect of high-energy ion beam irradiation on
Te of Fe-31.9 at%Ni Invar alloy was investigated using
an ac-field method. To observe the Curie temperature for such a thermodynamically unstable specimen
as in the case of the present study, a rapid method of
observation is needed. In the present experiment weused a specially designed apparatus for instantaneous
measurements of ac-susceptibility-temperature curves.
By using the present method, it is possible to complete the measurement of the temperature dependenceof ac-susceptibility from room temperature to 500 K
within 90 sec. The irradiations were carried out atroom temperature with 3.54 GeV Xe ions at fluenciesof the order of 10 12 /cm 2, using the RIKEN Ring Cyclotron. The observed ac-susceptibility- temperature
curves after the irradiations are shown in Fig. 1. The
ac-susceptibility decreases suddenly at the Curie temperature. In this figure it is evident that Te increases
with the irradiation dose. The Curie temperatures
were determined to be 410, 414 and 417 K for 1, 3
and 5 x 10 12 ions/cm 2 irradiations , respect ively.
Considering the large negative pressure dependenceof Te in Fe-Ni Invar alloys, the present experimental

5 x 10 :~ ions/em 2
3 X 10 12 ions/em 2
1 X 10ions/em 2

360

380

400

420

TEMPERATURE ( K )Fig. 1. Temperature dependence of ac-susceptibilities for
Fe-31.9 at%Ni Invar alloys after irradiation with
3.54GeV Xe ions to a dose up to 5 X 10 12 ions/cm 2 .

result that Te increases with the irradiation dose implies that a negative pressure has been introduced tothe specimen by the high-energy ion irradiations. Sucha negative pressure may be expected to be generated
along the paths of the ion beams through high-density
electron excitations.
References
1) For example, The Invar Effect: A Centennial Symposium, edited by J. Wittenauer (The Minerals, Metals &Materials Society, USA, 1997).
2) P. Entel, E. Hoffmann , P. Mohn, K. Schwarz, and V. L.
Moruzzi: Phys. Rev. B 47, 8706 (1993).
3) J. M. Leger , C. Loriers-Susse, and B. Vodar: Phys. Rev.
B 6, 4250 (1972).
4) F. Ono, M. Asano, R. Tanaka, S. Nakamichi, and S.
Endo: Physica B 177, 127 (1992).
5) S. Endo, M. Nishino, and F. Ono: Sci. Technol. High
Pressure 2, 850 (2000).

*1 Department of Physics , Okayama University*2

Japan Atomic Energy Research Institute89

RIKEN Accel. Prog. Rep. 35 (2002)

Final lattice sites and atomic motion of 57Fe atoms in Si
immediately after GeV-ion implantation
Y. Yoshida,* S. Ogawa,* Y. Kobayashi, and A. Yoshida
The RIKEN RI-beam factory is expected to provide a wide variety of radioisotopes, many of which aresuitable for use as nuclear probes in Mossbauer spectroscopy (MS), perturbed angular distribution (PAD),
and other nuclear methods . High-energy GeV-ion implantation, however, would produce serious lattice defects along the ion tracks and near the final lattice sitesof the probes , making it very difficult to study the local surroundings and the atomic motion of the probes
deeply implanted in a bulk material. In order to determine the damage effects in the Mossbauer spectra
obtained by 2-GeV 57Mnj57Fe implantation in Si,l)we compare the in-beam spectra with those obtained
from a laboratory Mossbauer experiment on 3 nm-thick
57Fe-deposited CZ-Si under thermal equilibrium.
The absorption spectra were measured under a vacuum of 10- 6 Pa between 300 and 1273 K. The Fe concentration was estimated to be 2 x 10 17 Fe/cm 3 fromthe thickness of the Fe layer, i.e., at least two orders ofmagnitude higher than that of Fe solubility reported at1273 K ,2) and seven orders of magnitude higher thanthat of the in-beam experiment . I) When the specimen temperature was increased , ex-Fe first appeared
at 300 K and subsequently different Fe-Si compounds
were formed at higher temperatures . After measurement at 1273-K for one week, a singlet became thedominant component , corresponding to Fe on substitutional sites in Si. The spectra obtained at thermal
equilibrium are shown in Fig. 1, which are comparedwith those obtained from the former in-beam experiment 1) on 57Mnj57Fe in FZ-Si (Fig. 2). In the in-beamspectra at 418 and 625 K, Fig. 2 clearly shows both interstitial and substitutional Fe components on the leftand right- hand side, respectively. In the present experiment , on the other hand, only the substitutional
component is observed (Fig. 1) , indicating that the Featoms exist mainly on the substitutional sites. Moreover, the small interstitial component with a fraction------Df about 5% may also be seen in the spectra measured
at 573 K and 773 K. The present result , however , completely contradicts the picture generally accepted so
far for the lattice sites as well as for the solubility of
Fe atoms in Si. 2)
Furthermore , in the in-beam experiment, both thedisappearance of the interstitial component and the simultaneous relaxation effect on the centre shifts wereobserved at approximately 650 K , which could be interpreted to be the jumps of interst itial Fe atoms into vacancies. 1 ) Since the substitutional component shows noline-broadening due to diffusion and is therefore quite
Shizuoka Institute of Science and Technology

90

100.0

99.5
:l
c:

8100.0

'0

.~

iii

E 99.5
~

c:

100.0

99.5
-2

-1

o
Velocity I mms'·

Fig. 1. Mossbauer spectra at thermal equilibrium obtained
from the laboratory experiment, which shows only substitutional Fe components in Si.

100

90

<II

=
g 100
<.I

'0

.~

iii

E 90
~

c

100

90

-2

-1

Velocity I mms'·

Fig. 2. In-beam Mossbauer spectra which consist of interstitial and substitutional Fe components.

stable even at 1273 K , the dynamical behavior observedin the in-beam experiment should correspond to a recovery process from a nonequilibrium to an equilibrium
state around the nuclear probes.
References
1) Y. Yoshida and K. Kobayashi et al.: Defect Diffus. Forum 194, 611 (2001).
2) A. A. Istratov, H. Hieslmair, and E. R. Weber: Appl.
Phys. A 69 , 13 (1999); A. A. Istratov, H. Hieslmair, andE. R. Weber: Appl. Phys. A 69 , 489 (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

On-line TDPAC studies using the 19 0 beam
W. Sato, H. Deno, H. Watanabe, H . Ogawa,*1 H. Miyoshi,* 1 N . Imai,*2 A. Yoshimi,
K. Yoneda, D . Kameda,*1 Y. Kobayashi, and K. Asahi
The time-differential perturbed angular correlation(TDPAC) method has been widely applied to researchin condensed matter physics as well as nuclear physics,
and it has provided valuable information on hyperfine interactions. Applicable probe nuclei are, however, limited to those having long-lived parent nuclides
that allow chemical treatments for their introduction
into samples of interest, and this limitation could bea cause of the restriction of investigated samples. It
is hence of great importance to develop new probesthat can be applied to the TDPAC method. If it ispossible to produce short-lived nuclei and introduce
them into samples of interest immediately after theirproduction , those nuclei could be used as probes for
the TDPAC method. In the present work, we havetaken advantage of the advanced technology of particle acceleration and have developed a new short-lived
probe, 19F, disintegrated from the parent nuclide 19 0,
for a TDPAC study of fullerene C60 . 1 )The 19 0 beam was produced at the RIKEN Accelerator Research Facility. Ionized 22Ne was accelerated
by two-stage acceleration with the AVF cyclotron andring cyclotron up to 110 MeV lu at a beam intensityof 150 pnA . The secondary beam 19 0 was produced
using the RIKEN projectile-fragment separator. 2) A
well-focused pulsed 190 beam of 65 MeV lu was implanted in the sample , and on-line TDPAC measurements were performed on the (1357-197)-keV cascade
I rays emitted from 19F nuclei using sixteen BaF 2 scintillators arranged in four independent detector planes
to cover a solid angle of approximately 27T sr.
Prior to studying polycrystalline C 60 , the 19 0 beam
was implanted in distilled water for observing the magnitude of the directional anisotropy denoted by the
angular correlation coefficient A 22 . The TDPAC spectrum of 19F in the distilled water is shown in Fig. l.
As generally expected for nonviscous liquid samples,the directional anisotropy of the cascade I rays is negligibly perturbed. We accordingly fitted the spectrum
assuming the diffusion approximation for the timedifferential perturbation factor G 22 (t) . From the fit,
the angular correlation coefficient was experimentallyestimated to be A22 = -0.17 ± 0.0l.
The TDPAC spectrum for the polycrystalline
fullerene C 60 at 73 K is plotted in Fig. 2. Since thedirectional anisotropy shows a slowly relaxing damped
oscillatory structure, we interpreted the spectrum as
having two different components: one has a static electric quadrupole interaction with the extranuclear field*1*2

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

·0.3

0.1
0.2 L.........~...L........~-'--~"'""""'--"~--'
100
150
200
50
o

Time (ns)Fig. 1. TDPAC spectrum of 19F in d istilled water at room
tern perat ure.

73 K

0.05 c.........."""""'----....l~..........__...L.~o 50 100 150 200 250 300...................,

Time (ns)Fig. 2. TDPAC spectrum of 19F in polycrystalline fullerene
C 60 at 73 K.

and the other is dynamically perturbed by the field .
The electric-field-gradient (EFG) value for the firstcomponent was optimized by the least-squares fit as
IVzzl = (4.4±0.8) x 10 18 Vcm- 2. Taking into consideration reported values of the EFGs at the 19F nucleus
forming a C-F bond ,3) the estimated EFG value forthe first component would also reflect the same typeof interaction between the network carbons and fluorine atoms. In the case of the second component ,it is considered that the dynamic perturbation is attributed not to the thermally activated motion but tothe recoil effect triggered by the (3- particle emission
from the 19 0 nuclei, because litt le, if any, temperaturedependence can be observed in the TDPAC spectra.
For more detailed understanding of the interaction between the 19F probe and C60 molecules, the present
data should be compared with results of theoretical
calculations.
References
1) H. W. Kroto et al.: Nature 318 , 162 (1985).
2) T . Kubo et al.: Nucl. Instrum. Met hods Phys. Res. B
70 , 309 (1992).
3) M . G. Bossenger et al.: Hyperfine Interact. 120/121 ,
557 (1999) .

91

RIKEN Acce!. Prog. Rep. 35 (2002)

Stopping power measurement of 84Kr in a laser-produced plasma
A. Sakumi, T. Katayama, T. Nishimoto,* and Y . Oguri*
In the energy region of hundreds of keY lu, the energy dependence of the stopping power of oxygen ionsin a plasma is quite different from that in cold matter. 1- 3) Although the experimental investigation has
been conducted for a few species, the results are notsufficient to explain the physics involved in beamplasma interaction systematically. With this background, we have experimentally investigated the dependence of the stopping power in the plasma on theatomic number of various projectiles with fixed incident energy, ranging from Kr to Bi. These projectiles are available at the CNS (Center for Nuclear
Study, Univ. of Tokyo) beam line in the RILAC facility.
F igure 1 shows a schematic view of the experimental
setup. The energy loss of ions, which interact with thetarget plasma, is measured by the time-of-flight (TOF)
method. In order to filter the plasma light emission, agold foil is set in front of MCP. The laser, ion beam ,and the pulser are synchronized by the digital delay
generators.
A dense plasma is produced by irradiating a smalllithium hydride (LiH) pellet with a Q-switched Ndglass laser (,\ = 1.054 11m, 4.5J and 30ns (FWHM)).
The pellet diameter is approximately 60 11m. The irradiance of the laser on the pellet is 2 TW Icm 2 . The
target is a plasma with a density of 10 18 cm- 3 and atemperature of ~ 15 eV.
The beam consists of 1 MeV lu 84Kr17+ ions, delivered with the period of 32 MHz. Figure 2 shows thesignals from the bunch monitor behind the RILAC #3
cavity (a) and the stop detector (b). The beam duration of the (a) signal is about 2 ns in FWHM, whilethat of the (b) signal is about 5 ns in FWHM. The drift
distance from the #3 cavity and the stop detector isabout 50 m, and the momentum spread is 0.15%, sothat the spread of beam shape is observed. For good
accuracy of the experiment, we most decrease the beam
spread.

Ionsource8-1...-

LiH plasma target~-I-9. E'4K

Choppe(200!-ls pen)

Z9

.

0

••••••

Nd-glasslaser(4.5 J . 30 ns)

Storageoscilloscope
Digital delay generators

Fig. 1. Schematic view of the experimental setup.
Research Laboratory for Nuclear Reactor, Tokyo Instituteof Technology

92

oS 0

·1

time t Ins]

Fig. 2. Signals from the bunch monitor behind the RILAC#3 cavity (a) and the stop detector (b).
2 "'---~----r--~-----'~o-1Time t [nsJ

Fig. 3. Signals without (a) and with the plasma (b) .

84Kr

l'

~
.§200

Plasma:>~~OO
Cold (N_ort_h_
cli_
ffe~
) _

gf

_

~

.~

Vi

0.1

0.5
Beam energy [MeV/u]

Fig. 4. Stopping power in the LiH plasma with theoreticalestimation.

Figure 3 shows the signals without (a) and with theplasma (b). The energy loss was estimated by thetime duration between each signal. The maximal delay was 4.1 ns at t = 60 ns after the laser was fired andthe relevant energy loss was 3 Me V. The estimatedstopping power was 190 MeV I (mgl cm 2 ), as shown in
Fig. 4. Figure 4 also shows the stopping power calculated using the enhanced Bethe equation and the rate
calculation. The experimental result agrees with thecalculation.
References
1) T . Katayama: J. Plasma Fusion Res. 70, 323 (1994) .
2) A. Sakumi et al.: Nucl. Instrum. Methods Phys. Res. A
464, 231 (2001).
3) P. Nicolosi, E. Jannitti, and G. Tondello: Appl. Phys.
B 26 , 117 (1981).

RIKEN Accel. Prog. Rep. 35 (2002)

TOF spectral profile of fullerene-like fragment Ionsin C 6 + -C 60 collisions
Y. Nakai, T. Kambara, A. Itoh,*1 H. Tsuchida, *2 and Y. Yamazaki
A number of studies of C60 fragmentation havebeen performed with various excitation probes. I - 8 ) In
particular, production of fullerene-like fragment ions
(FLFI's) has been intensively studied . The time-offlight (TOF) peak profile for each product ion contains
information on fragmentation , that is, the kinetic energy release and lifetime. We have developed a highresolution TOF mass spectrometer to obtain information on the fragmentation mechanism. Using this spectrometer, we measured TOF peak profiles in the mass
range of cto to Ct8 for fragmentation by 2.5 MeV lu
He 2+ ion impact and compared them with the simulation of sequential C 2 emission based on the RiceRamsperger-Klein-Marcus (RRKM) formalism. It was
shown that the experimental results support high activation energies (9.5 eV for cto) and a very loose transition state. g ) Here, we report TOF spectral profiles ofheavy fragment ions by 2.5 MeV lu C6 + impact . The
beam of 2.5 MeV lu C6 + was accelerated by the RIkenLinear-ACcelerator (RILAC). The details of our experiment setup are described in Ref. 10.
Figure 1 (a) shows an experimental TO F spectrum
in the range of cto to Ct8 by 2.5 MeV lu C6+ impact.
Generally, the peak intensities of CtO-2n (n = 1 to5) decrease exponentially with n. These peaks havethe following features: The tail of each peak of singly
charged FLFI on the longer TOF side is found to curvemuch more gently than that on the shorter TOF side.

300.:?:iii
c:

2

.£

(a)

200

100

12800

c-

13200

13000

13400

13600

13800

14000

References

1000

'Vi
c:

2 500

.s

9000

9200

9400

9600

9800

10000

TOF (ns)Fig. 1. (a) Experimental TOF spectrum in the range ofcta to Ct8 by 2.5 MeV lu C6 + impact. (b) Experimental TOF spectrum in the range of c~t toby C 6 +impact.

c;tThis asymmetry becomes less prominent with lighter
fragment ions. The short vertical lines in Fig. 1 (a)represent the TOF peak positions of the 12ctO_2n fragment ions when they are produced promptly with zero
recoil energy. It is seen that all the TOF peaks are
not only tailed to but are also shifted to the longer
TOF side than the corresponding vertical lines. Thesefeatures strongly indicate that the fragmentat ions takeplace after C60 is ionized by a projectile ion. The features of the TOF peak shape by C 6 + impact are verygsimilar to those by 2.5 MeV lu He 2+ impact. ) Thissimilarity indicates that the production mechanism of
singly charged FLFI by 2.5 MeV lu C6 + impact is thesame as that by 2.5 MeV lu He 2+ impact.
Figure 1 (b) shows an experimental TOF spectrum
in the range of c~t to c~t by C 6 + impact. The shortvertical lines in Fig. 1 (b) represent the TOF peak positions of the I2c~t_2n fragment ions when they are
produced promptly with zero recoil energy. The TOF
spectrum of doubly charged FLFI is similar to thatof singly charged FLFI. This TOF spectral similarity between singly charged FLFI and doubly charged
FLFI indicates high activation energies of C 2 emission
from doubly charged fullerene ions as singly charged
fullerene ions because the shape of the TOF peak issensitive to the activation energy. A very recent study
using a storage ring revealed that the activation energies of C 2 emission from doubly charged fullerene ionsare close to those from singly charged fullerene ions in
the mass range of C 48 to C 70 . 11 ) The similarity of the
TOF spectra also implies that production mechanismsof doubly charged FLFI are the same as those of singly
charged FLFI. Namely, it implies that the sequential
C 2 emission from excited c~t ions is a dominant production mechanism of doubly charged FLFI.

1) Y. Nakai et al.: J. Phys. B 30, 3049 (1997).
2) M. Foltin et al.: J. Chern. Phys. 107, 6246 (1997).
3) P. Weis et al.: J. Chern. Phys. 104,6246 (1996) .
4) R. Woergoetter et al.: J . Chern. Phys. 10 1, 8674
(1994) .
5) M. Foltin et al.: J. Chern. Phys. 98, 9624 (1993).
6) R. K. Yoo et al.: J. Chern. Phys. 96, 911 (1992) .
7) J. Laskin et al.: Chern. Phys. Lett. 242, 249 (1995).
8) J. Laskin et al.: Int. J. Mass Spectrom. 177, L9 (1998).
9) Y. Nakai et al.: RIKEN Accel. Prog. Rep. 34, 102(2001).
10) Y. Nakai et al.: RIKEN Accel. Prog. Rep . 33 , 79
(2000) .
11) S. Tomita et al.: Phys. Rev. Lett. 87, 073401 (2001).

* 1 Kyoto University*2 Nara Women's University

93

RIKEN Accel. Prog. Rep. 35 (2002)

Lattice location of hydrogen in Nb-Mo alloys
E. Vagi, S. Koike,*l T. Matsumoto,*2 T. Urai, N. Tajima, and K. Ogiwara
Regarding the effect of alloying on the terminal solubility of hydrogen (TSH) in group Va metals in the
periodic table (V, Nb and Ta), it has been reported
that for undersized metal solutes, e.g., Nb in Ta andMo in Nb, the TSH increases rapidly with metal soluteconcentration up to a certain solute concentration, andfor oversized solutes, e.g., Ta in Nb and Nb in V, theTSH also increases with solute concentration but lessrapidly. 1,2) In order to understand the mechanism of
this effect, the lattice location of hydrogen in such alloy
systems is to be investigated. Previously we performed
channelling studies to locate hydrogen in Nb-based NbMo alloys with various concentrations of Mo up to 20
at. %. The result showed that, at low Mo concentrations, H atoms are trapped by Mo atoms at room temperature and are located at sites which are displaced
from tetrahedral (T) sites by about 0.6 A towards thenearest-neighbour lattice points (trapped sites T tr ). 3)
At a high Mo concentration, 20 at .%Mo, H atoms are
not observed at such T tr sites, but a major portionof them are located at T sites, and 20- 30% of them
are at octahedral (0) sites at low hydrogen concentrations. 4 ) These results indicate that the hydrogen site
occupancy changes with the Mo concentration , C Mo .
The Nb-Mo alloy system forms a solid solution overthe entire Mo concentration range. The TSH in Nb
at room temperature is about 4 percent, whereas the
TSH in Mo is very low. Therefore, systematic studies
on the C Mo dependence of hydrogen site occupancy aredesired.
In the present study, the lattice location of hydrogen in an alloy with a higher Mo concentration of 26
at. % is investigated at room temperature by a channelling method utilizing a nuclear reaction 1H(l1 B, a)a a with a 11 B beam of about 2 MeV, as in previous
studies. 5 ,6) For comparison, the lattice location of hydrogen in pure Nb is also investigated. Hydrogen wasdoped from the gas phase to a hydrogen-to- metal-atomratio CH = [Hl/[M] of 0.023 for the Nb specimen, andthree different values of C H = 0.016, 0.026 and 0.059
for the Nb- Mo alloy specimens. The channelling angular profiles obtained for the alloys are very similar to
those of the Nb specimen. Based on the comparison of
the observed angular profiles with the calculated ones,
it is concluded that, irrespective of the hydrogen concentration, more than 90% of H atoms are located at
T sites in the Nb(74 at.%)-Mo(26 at .%) alloys . Even
if H atoms are located at 0 sites, the proportion is lessthan 10%. This is different from the result for H in
Nb(80 at.%)-Mo(20 at.%) alloys , in which, at low hy*1

*2

94

Department of Physics, Tokyo University of Science
National Institute for Materials Sciencedrogen concentrations, a 20- 30% O-site occupancy by
H atoms was observed in addition to T-site occupancy.
The site change of hydrogen in the Nb-Mo alloys
containing up to 20 at. %Mo has been explained as fol10ws. 4 ) At low C Mo , the strain field induced by the undersized Mo atoms is localized and the internal strain
is relaxed by hydrogen occupation of interstitial sites
neighbouring Mo atoms; H atoms occupy well-defined
T tr sites near Mo atoms due to attractive elastic interaction between them. At high C Mo , there will bea statistical distribution of local atomic configurations
and concomitant distribution of interstitial site energy.
In addition, the interference of the strain field inducedby nearby Mo atoms influences the distribution of interstitial site energy. Correspondingly, trapping behaviour will become less well defined, and therefore,
the number of H atoms located at Ttr sites per Mo
atom becomes smaller. At much higher C Mo , i.e., 20
at. %Mo, the average separation between Mo atoms
becomes even smaller, and the effect of strain fields
of individual Mo atoms tends to be averaged out. It
would be more appropriate to regard this alloy as apure metal having a homogeneously reduced lat tice parameter. As a result, the energy difference between T
and 0 sites becomes smaller, and 0 sites become moreeasily available for occupation.
The present result for the Nb(74 at.%)-Mo(26 at.%)alloys, however , cannot be explained by such a size
effect. In the Nb(74 at.%)-Mo(26 at.%) alloys, the lattice parameter is considered to be smaller than in the
Nb(80 at.%)-Mo(20 at.%) alloys . Therefore, on the basis of the size effect, a larger fraction of the O-site occupancy would be expected in the Nb(74 at.%)-Mo(26at.%) alloys . The experimental result is incompatible
with this expectation. Therefore, other effects should
be taken into account to explain the site occupancy
of hydrogen in 26 at. %Mo alloys. The experiments on
more concentrated alloys are now in progress .
References
1) T. Matsumoto, Y. Sasaki, and M. Hihara: J. Phys.
Chern. Solids. 36 , 215 (1975) .
2) D. G . Westlake and J. F. Miller: J. Less-Common Met.
65 , 139 (1979).
3) E. Vagi, S. Nakamura, F. Kano, T. Kobayashi, K.
Watanabe , Y. Fukai, and T. Matsumoto: Phys. Rev.
B 39 , 57 (1989).
4) E. Vagi and S. Koike: J. Phys. Soc. Jpn. 67, 340 (1998).
5) E. Vagi, T. Kobayashi, S. Nakamura, Y. Fukai, and K.
Watanabe: Phys. Rev. B 31 , 1640 (1985).
6) E. Vagi , T. Kobayashi, S. Nakamura, F. Kano, K.
Watanabe, Y. Fukai, and S. Koike: Phys. Rev. B 33,
5121 (1986).

RIKEN Accel. Prog. Rep . 35 (2002)

High-resolution soft X-ray measurements in 2.3 keY lu
N + ions transmitted through an Au microcapillary target
7

Y. Iwai,* 1 Y. Kanai, H. Oyama, K. Ando, H. Masuda,*2 K. Nishio,*2
M. Nakao,*3 T. Tamamura,*3 K. Komaki,*1 and Y. Yamazaki
X-rays emitted from 2.3 keY lu 15N7+ ions transmitted through a thin Au micro capillary foil were measured with a high-resolution soft X-ray spectrometer,
to study the formation and relaxation dynamics of ahollow atom (ion)1) produced by a resonant chargetransfer in ion-surface collisions.
The present study was performed using a 14.5 GHz
Caprice type electron cyclotron resonance ion source
in RIKEN. 2) Recently, a new method of manufacturing the microcapillary foil has been developed involving a nanolithographic technique, which allows the
preparation of a highly ordered microcapillary foil. 3)
In the present experiment, an Au microcapillary foil
was used , which was ---- 1 mm 2 in area with a thicknessof ---- I j.Lm, many straight holes of ----100 nm in diameter, and a honeycomb structure with a 200 nm interval, i.e., the geometrical opening ratio was ---- 25%. It
was expected that efficiency would be good comparedwith that of a former target. 4 ) A detailed descriptionof the high-resolution soft X-ray spectrometer is given
in Ref. 4.
Figure 1 shows an X-ray spectrum, which was taken
immediately downstream of the target, for 2.3 keY lu
15N7+ ions transmitted through the microcapillary.
The eight major lines are attributed to hydrogen-likeand helium-like transitions, which are summarized inTable l.5) It is expected that the relative intensity ofeach transition refiecs the cascade transition of the hollow atom (ion). The transitions of np-1s (5 S; n S; 8)were observed with the highly ordered microcapillarytarget for the first time and the transition from nineor more n was not observed as a peak. According to
the classical over barrier model (COBm), the principal
quantum number n c in which electrons are resonantly
captured from the target is given by-0.2 L.........~_~--'-'-~..-...L~..........J.~~L......-'--'--'
400
450
500
550
600
650
700

Energy (eV)Fig. 1. Spectrum of K X-rays , measured with the spectrometer immediately downstream of the target, for
2.3 ke V lu 15N7+ ions transmitted through a highly ordered Au microcapillary. Bars with transition terms
show transition energies and 1* indicates N VII ionization potential energy.5)

Table 1. Observed transition energies and electronic configurations.
Experiment Ref. data 5) Configurations
430.4 ± 0.4 eV
500.3 ± 0.5 e V
593.1 ± 0.7 eV
626.1 ± 0.7 eV
640.3 ± 0.7 eV
648.6 ± 0.8 eV
654.2 ± 0.8 eV
657.1 ± 0.8eV

430.7 eV
500.3eV
500.2eV592.geV625.4eV
640.4 eV648.5eV653.4eV656.6eVIs2p - t Is2
2p - t Is
2p - t Is
3p - t Is
4p - t Is
5p - t Is
6p - t Is
7p - t Is
8p - t Is

9p - t Is
658.8eV667.1 eV*
* N VII ionization potential energy
Cf.

where q is the charge state of the ion and W is the work
function of the target (physical quantities are given
in atomic units).6) The principal quantum numbers of
the initially populated states can be estimated as n rv
q + 1 = 8 in the present case. It is possible that the
principal quantum number of the initially populated
states is n rv 8. The experimental result was consistent*1 Institute of Physics , Graduate School of Arts and Sciences,
University of Tokyo*2 Department of Applied Chemistry, School of Engineering,*3

Tokyo Metropolitan University
NTT Corporation

Terms
1PI - t ISO
2P 3 / 2 - t 28 1/ 2
2P 1/ 2 - t 28 1/ 2
2P 3 / 2 - t 28 1/ 2
2P 3 / 2 - t 28 1/ 2
2P 3 / 2 - t 28 1/ 2
2P 3 / 2 - t 28 1/ 2
2P 3 / 2 - t 28 1/ 2
2P 3 / 2 - t 28 1/ 2
2P 3 / 2 - t 28 1/ 2

with the prediction of the COBm.
References
1) 8 . Ninomiya et al.: Phys. Rev. Lett. 78, 4557 (1997).
2) Y. Kanai et al.: RIKEN Rev., No. 31 , 62 (2000) .
3) H. Masuda, H. Yamada, M. 8atoh, H. Asoh, M. Nakao ,and T. Tamamura: Appl. Phys. Lett. 71 , 2770 (1997) .
4) Y. Iwai et al.: RIKE R ev., No. 31, 34 (2000).
5) R. L. Kelly: J. Phys. Chern. Ref. Data 16, 8uppl. 1(1987).
6) J. Burgdoerfer, P. Lerner, and F. W. Meyer: Phys. Rev.
A 44, 5674 (1991).

95

RIKEN Acce l. Prog. Rep . 35 (2002)

Visible light emission from slow highly charged ions transmitted
through a Ni microcapillary
Y . Morishita, R. Hutton,*1 Y. Kanai, K. Ando, H. Masuda,*2 H. A. Torii,*3 K . Komaki ,*3 and Y. Yamazaki
In the study of the neutralization process of a slow
highly charged ion (HCI) above a metal surface, one of
the most difficult and unavoidable experimental problems is that the HCI collides violently with t he surface
within .:s 10- 13 sec due to its image charges inducedon the surface. Hence, observers mainly observe thefinal moment, or the integrated memory of the neutralization process. A technique of using microcapillary targets made it possible to extract such ions in
vacuum, which are in different stages of the neutralization above the surface. 1) With the aim of observing thefirst electron transfer, we have constructed a beam linewith a spectrometer in the visible light region, whichis schematically shown in Fig. 1. HCIs, supplied by a
14.5 GHz Caprice ECRIS in RIKEN, are first impinged
into a micro capillary target made of nickel which is
100 nm in diameter and 700 nm in thickness. Photons
emitted from the HCIs downstream of the capillary arethen collected with aluminum-coated two flat and one
spherical concave mirrors, and imaged onto a slit of
the spectrometer with 500 mm focal length, in which
the photons are dispersed and detected with a backilluminated CCD cooled to -120°C.
Figure 2 shows a spectrum observed with 2.0 keY lu
Ar 7 + incident ions, the wavelength region of which corresponds to l:ln = -1 transitions of the exiting ions,which have captured one electron into a state with its

Quartz windows

HCls

I
I

Apertures' fN i microcapillary

Fig. 1. Schematic drawing of the experimental setup installed in the hall for slow highly charged ions at
RIKEN .
*1
*2

*3

96

Department of Physics, Lund University, Sweden
Department of Industrial Chemistry, Tokyo Metropolitan
University
Institute of Physics, Graduate School of Arts and Sciences,
University of Tokyo

1000

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500
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380

( ((I

385

A

(8,5)-(7,4)

390

395

400

Wavelength (nm)Fig. 2. A spectrum around n = 7-8 transitions of Ar 6 +ions. Transitions with fi down to 5 can be observed, andlines show splittings due to fine structures for smallerfi transitions .

principal quantum number of ni = 8. The spectrum
consists of seven clearly separable lines, and is thought
to reflect the difference of the initial angular momentum (f i ) of the captured electron.
For the identification of each line, we calculated transition wavelengths using multi-configuration
Hartree-Fock codes, accounting for various wavefunctions for doubly excited states, i.e.,
3f 3l, 3snl f, 3pn2 f, 3dn3 f,

where nl = 4- 11 , n2 = 4- 6 and n3 = 4- 5. One oft he main reasons for this selection for wavefunctions
is based on a fact that energy levels for singly excitedstates of Ar 6 + (3snf) ions are very close to those fordoubly excited 3pn' e' states because of a small gap
between the 3s and 3p states of Ar 7 + ions. Althoughtransition wavelengths can not be predicted with sufficient accuracy, relative line positions make it possible
to identify each line. The calculated results are shownby bars in Fig. 2. Here, (1) lines with the same fi number split into some components due to fine structuresof the states involved in the transitions, i. e., two components for fi = 6 transitions and four components
for fi = 5 transitions, and (2) fi = 5 transitions have
longer wavelengths than fi = 7,6 transitions due tothe configuration interactions stated above, which isvery different from a simple hydrogenic picture of an
excited ion with a finite-sized core.
References
1) S. Ninomiya et al.: Phys. Rev. Lett. 78 , 4557 (1997).

RIKEN Accel. Prog. Rep. 35 (2002)

Improvement of experimental setup for Ion-atom crossed-beammeasurements at energy range below 100 eV /q
M. Hoshino,* M. Kitajima,* Y. Kanai, Y. Nakai, H. Tanaka,* and Y. Yamazaki
Multielectron capture processes in highly chargedion (HCI) and neutral atom collisions have become
one of the central topics of research in atomic collision physics. In the low-energy region, generally whenthe velocity is below 1 au, differential cross sections(DCSs) are very important for understanding interaction potential energy curves, which are essential in thedetailed study of HCI-atom collision dynamics. Therefore, we have produced a crossed-beam experimental
setup for DCS measurements of HCI-atom collisions
in the energy range below 100 eV /q.l) It is known thatthe oscillation structure called Stiickelberg oscillation
appears in DCS of HCI-atom collision. This resultsfrom the interference effects between the ions scattered along different paths on the interaction potential
curves. Therefore, information about the oscillation
structure in DCS is very important for understanding the interaction of HCI-atom collisions. In orderto observe this oscillation structure, sufficiently highangular resolution is needed, for example, less than
±0.5° at the collision energy of 100 eV /q. However,for the DCS measurements in the C4 + -He collision system which we have reported,2,3) the angular resolution
was not sufficiently high, so that the physical information about the interaction in these system was not
obtained. Therefore, the experimental setup has been
improved to enable us to monitor the size, the shapeand the angular divergence of the HCI beam directly.
A collision chamber is set at the BL2 of the 14.5 GHz
Caprice ECR ion source in the RIKEN Experimental Hall for slow highly charged ions. 4 ) The collisionchamber consists of a beam energy selector, an effusive nozzle and a scattered ion analyzer. Recently, we
installed a beam-profile monitor in the collision chamber. The beam-profile monitor is set at the turntablewith the scattered ion analyzer and can rotate from0° to 60°. The beam-profile monitor is a multichannel
plate (MCP) with a phosphor anode. Active diam-

Fig. 1. A typical beam profile of the N 4 + ion beam at
100eY /q obtained by the CCD camera.

eter of the MCP is 10 mm . The image of the beamon the phosphor screen is guided by two sets of plane
mirrors and is monitored from outside of the collisionchamber with a CCD camera. The beam-profile monitor can be moved away from the collision region to a
40 mm distance, so that the size and the angular divergence of the HCI beam can be estimated directly. The
beam adjustment to obtain a high quality HCI beam
can be easily carried out. A typical profile of the N4 +ion beam at 100eV /q obtained by the CCD camera isshown Fig. 1. Typical beam current is about 100 pA
in the collision volume at energy of 100 e V / q. N 4 + ion
beam with about 2 mm diameter and ±0.5° angulardivergence at 100eV /q is obtained.
References
1) M. Kitajima et al.: Phys. Scr. T 80, 377 (1999).
2) M. Hoshino et al.: RIKEN Accel. Prog. Rep. 34, 108(2001).
3) M. Hoshino et al.: Phys. Scr. T 92, 339 (2001).
4) Y. Kanai et al.: Phys. Scr. T 92 , 467 (2001).

Department of Physics, Sophia University

97

RIKEN Accel. Prog. Rep . 35 (2002)

Current status of a cooling system for MCI using positron plasma
N. Oshima, T. M. Kojima, M. Niigaki,* A. Mohri, and Y. Yamazaki
Interaction between ultralow-energy multi-charged
ions (MCls) less than 1 eV /q and atoms/surfaces has
not yet been investigated ,l) since no realistic techniqueto produce ultraslow MCls has been developed. In order to study this undeveloped field , a project to produce ultraslow MCls using a positron cooling technique
is under way. The principle of the positron coolingtechnique is the same as that of the electron coolingone, which has been successfully applied for producing
low-energy antiprotons. 2) Charged particles stored in astrong magnetic field lose their energies via cyclotron
radiat ion, the rate of which is inversely proportional
to the particle mass cubed. This fact means that if
light and heavy particles are stored in a strong magnetic field simultaneously, the light particles behave as
cooling agents of the heavy particles. Positrons are
expected to be particularly useful because the recombination of positrons with positive ions does not takeplace, i . e., the stored ions remain their initial charge
states during the cooling. The cooling time of 10 6
MCls from 10 4 eV to 10- 1 eV would be a few seconds
when 108 positrons are stored in a trap at 5T. An
ultralow-energy beam is generated if cooled MCls are
extracted slowly from the trap.
The cooling of MCls will be practically realized in
the following way3) (see Fig. 1): (1) 10 10 electrons,
which are used as cooling agents for accumulating
positrons, are trapped in a multi-ring electrode 4) at
B=5T; (2) slow positrons are guided magnetically froma 22Na-based slow positron source into the trap. In
the trap, the positrons are first re-moderated with atungsten single crystal, then they are injected into the
pre-loaded electron plasma. The slow positrons thus
prepared are eventually trapped at the bottom of thepotential valley. The positron trapping efficiency is
expected to be 20- 30%;5) (3) MCls produced at an
ECR ion source are injected into the trap and cooledwith the positron cloud; (4) the cold MCls (and thepositrons) are extracted from the trap by ramping thepotential valley. The cold MCI beam produced by sucha method would be transported via an electrostaticlens system 6 ) from the trap to a magnetic field free
region for various experiments.
To date, we have constructed the following hardware: (1) the slow positron source 5); (2) the beamline
which can guide both positrons and MCls to the trap;(3) a 50-em-long multi-ring electrode t rap3,4) which
consists of 23 electrodes. The slow positron source

Institute of Physics, Graduate School of Arts and Sciences,
University of Tokyo98(1) e- accurrulation:,~electric gate(2) e+ accurrulationov

slowe+(3) e+ cooling of HCIov(4) extraction of cold HCI beam~oV

\ : uitraooWo+&HChUL

e+ & HeI PlasllB

Fig. 1. Procedure of HCI cooling.

generates 2.5 x 106 positrons/sec using a 30mCi 22Na
radioactive source, and the beamline can transport
all of the slow positrons to the trap. The multi-ringelectrode trap successfully confined an electron plasma
with a long lifetime of about 8 hours.
Now we are studying a technique for controling theelectron plasma precisely, particularly its charge distribution, since the positron trapping rate strongly depends on this parameter. 5) We will start the positronaccumulation experiment after optimizing the parameters of the electron plasma.
References
1) Y. Kanai et al.: RIKEN Rev., No. 31, 62 (2000).
2) Y. Yamazaki et al.: Nucl. lnstrum. Methods Phys. Res.
B 154, 174 (2000).
3) T. M. Kojima et al.: RIKEN Rev., No. 31, 70 (2000).
4) A. Mohri et al.: Jpn. J. Appl. Phys. 37, 664 (1998).
5) N. Oshima et al.: RIKEN Rev., No. 31, 65 (2000).
6) M. Niigaki et al: Abst. 12th Int. Conf. Photonic, Electric and Atomic Collision, Santa Fe, New Mexico, USA,2001-7, edited by S. Datz et al. (2001) , p. 689.

RIKEN Accel. Prog. Rep. 35 (2002)

Precision spectroscopy of the Zeeman splittings of the 9Be+ 2 2S 1 /2
hyperfine structure levels
T. Nakamura, M. Wada, K. Okada,* 1 1. Katayama,*2 S. Ohtani,*3 and H. A. Schuessler*4
To date, precision measurements of the Zeeman
splittings of the ground-state hyperfine structure(HFS) of trapped ions have been performed mainlywith the aim of developing frequency standards. We
have proposed the application of this technique in the
study of the nuclear structure of the various Be isotopes. 1)
The hyperfine constant A shows a small but finite
isotope dependence. The main part of this hyperfine
anomaly stems from the finite distribution of the magnetism over the extended nucleus and is known as the
Bohr-Weisskopf effect.2) The effect is empirically described by
A = Apoint(1 + fBW),

where A and Apoint are the hyperfine constants forextended and point-like nuclei , respectively, and fBW
is the anomaly. Since Apoint cannot be obtained experimentally, we compare the ratio of A to the nuclear
gI-factor among the isotopes. The differential anomaly
Al/gl
ID.2I
1r-v 1
2= A2/ J r-v fBW - fBW ,g
can then be evaluated.
We plan to investigate the neutron halo structure of
the 11 Be nucleus by means of the measurements of the
Bohr-Weisskopf effect which is sensitive to the radial
distribution of the loosely bound valence neutron. A
recent theoretical estimate supports the importance of
the investigation of the Bohr-Weisskopf effect in connection with the nuclear structure of 11 Be. 3) We havebeen working towards the development of exact experimental techniques for this purpose. 4- 6 )In order to investigate the Bohr-Weisskopf effect of
11 Be, we must determine the hyperfine constant A andnuclear g-factor gI for all of the odd Be isotopes withan accuracy of at least 10- 6 . A combined linear trap,
which consists of a superconducting Helmholz magnet and a linear rf trap, was constructed 7) for testinga laser microwave multiple resonance method . Figure 1 shows typical microwave resonance spectra forthe nuclear spin flip resonance and the electron spin
flip resonance of 9Be+ under an external magnetic
field of 0.47T. We were able to determine the hyperfine constant A and the nuclear gI-factor in unitsof the atomic gr factor from the two sets of resonance frequencies using the Breit-Rabi formula. The
*1

*2
*3
*4

Department of Physics, Sophia University
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
Institute for Laser Science, University of ElectroCommunications
Department of Physics, Texas A&M University, USAto v 1=12245353.9(17JkHz.FWHM=8kHz
200

300
400
500
microwave frequency (+ 12 245 (00) [kHz]

~ 800

.&>

~

§ 600

~

~ 400
OIl

t

321 602 594.04 (30) [Hz)

·Vi

~ 200

o (b) Ramsey' method ( 1: =10 ms, T =22 ms)
500

550
600
650
700
uhf frequency (+321602000) [Hz]Fig. 1. Electron spin flip resonance (top) and nuclear spin
flip resonance (bottom) spectra of the ground-state hyperfine structure of 9Be+ obtained by laser microwave
multiple resonance spectroscopy under an external magnetic field .

values obtained are A = -625008835.23(75) Hz andg~ / gJ = 2.13478033(28) x 10- 4.8 ) These values areslightly inconsistent with the NIST results by about
20".9) A reason for this disagreement could be a possible quadratic dependence of the hyperfine constant A
on the strength of the external magnetic field. lO ,l1) We
plan to confirm this theory in further experiments bymeasuring the magnetic field dependence with greater
accuracy.
References
1) M. Wada et al.: Hyperfine Interact. 81, 161 (1993).
2) A. Bohr and V. F. Weisskopf: Phys. Rev. 77, 94(1950).
3) T. Fujita et al.: Phys. Rev. C 59, 210 (1999).
4) M. Wada et al.: Nucl. Phys. A 626, 365c (1997).
5) S. Fujitaka et al.: Nucl. lnstrum. Methods Phys. Res.
B 126, 386 (1997).
6) K. Okada et al.: J. Phys. Soc . Jpn. 67, 3073 (1998).
7) T. Nakamura et al.: J. Appl. Phys. 89 , 2922 (2001) .
8) T. Nakamura et al.: accepted for Opt. Commun.
9) D. J. Wineland et al.: Adv. At. Mol. Phys. 19, 135(1983).
10) N. P. Economou et al.: Phys. Rev. Lett. 38, 1394
(1977) ; S. J. Lipson et al.: Phys. Rev. Lett. 57, 567(1986); G. D. Fletcher et al.: Phys. Rev. Lett. 58, 2535
(1987).
11) N. Fortson: Phys. Rev. Lett. 59, 988 (1987).

99

RIKEN Accel. Prog. Rep. 35 (2002)

A cryogenic ion trap for improving the trapping lifetimeof Be+ ionsK. Okada,*1 M. vVada, 1. Katayama, *2 L. Boesten,*1 T. Nakamura, and S. Ohtani*3
Laser-microwave double resonance spectroscopy of
trapped ions enables us to precisely measure the hyperfine structure splitting of alkali earth ions. We haveproposed systematic measurements of the hyperfine
structures of unstable Be isotopes in order to study
the Bohr-Weisskopf effect. I) Normally, we have only
minute amounts of unstable isotopes available to us.
Thus, it is important for the laser spectroscopy of suchions to minimize the loss of the trapped ions. Moreover, buffer gas cooling is also essential for trapping
such externally injected ions. 2,3) The main causes of
the ion loss are kinematic collisions with heavy residual
background gases and chemical reactions with impurities. These problems can be solved by using a cryogenic
trap whose electrodes can work as powerful cryopumps
for such impurities in the trap region .4 ) We report thedevelopment of a cryogenic linear rf ion trap for improving the trapping lifetime of light Be+ ions.
We used an experimental setup similar to that described in our previous paper. 5 ) The modifications are
as follows. The linear rf trap was enclosed by double
cryogenic cylinders. A cylindrical radiation shield incontact with a liquid helium (LHe) reservoir (1.61) was
surrounded by an outer cylinder in contact with a liquid nitrogen (LN 2) reservoir (3.01). The coolant injection pipes were welded to the LHe reservoir and passed
through the LN2 reservoir to reduce the evaporationof LHe by thermal inflow. The residual pressure inside
the vacuum chamber was approximately 5 x 10- 8 Pa
at room temperature. The pressure in the cryogenic
region was estimated from the pumping speed of thecryogenic parts and from conductance calculations to
be lower than 1 x 10- 10 Pa.
We measured the storage time of He-gas-cooled Be+
ions (Fig. 1). Typically, it was of the order of 10
seconds at room temperature, but it was extended
to about 15 min with LHe cooling (Fig. 1 (b)). In
our experiment, we showed that laser cooling assisted
buffer-gas cooling even under the LN 2 cooled condition(Fig. 1 (c)). These results indicate that a difference inthe amount of the impurities of less than 10- 9 Pa results in a considerably improved trap lifetime, i. e., thelifetime of trapped light ions is very sensitive to thequality of He gas.
We also measured the trap lifetime of laser-cooled
9Be+ ions under cryogenic conditions. A lifetime of
*1
*2

*3

100

Department of Physics, Sophia University
Institute for Particle and Nuclear Studies, High Energy Accelerator R esearch Organization (KEK)
Institute for Laser Science, U niversity of ElectroCommunications

ion production signal

+
(a)

(b)

(c)

o

4

8

12

time[minJ

Fig. 1. Time evolution of the fluorescence signal from Hegas-cooled 9Be+ ions. Trap lifetimes Tare 2.37(5) min
for the LN 2-cooled trap (a), 14.9(1) min for the LHecooled trap (b) , and 22.9(1) min for the LN2-cooled trap
assisted by laser cooling (c). Laser power was 600 p.W
for (c) , and 40p.W for (a) and (b). The stray lightlevel lies below the axis in all figures. irf = 2.457 MHz,Vac = 120 V pp, He gas pressure p = 4 X 10- 3 Pa.

178(3) min was obtained from the dominant time constant of the fluorescence decay curve. 6) This lifetime
is approximately 18 times longer than the corresponding lifetime at room temperature. A laser-cooled ion
crystal, which was lost within 10 minutes at room temperature, was kept for approximately 30 min without
any ion loss with the cryogenic linear trap.6)
The usefulness of a cryogenic linear rf ion trap forthe minimization of ion loss and for the long-term confinement of light Be+ ions was demonstrated in our experiment. Most of the ion-loss problems, particularly
for buffer-gas-cooled light ions, can be solved by using
a cryogenic ion trap. Such a cryogenic trap should also
be useful for the accumulation of ions of an unstable
isotope.
References
1) M. Wada et al. : Nucl. Phys. A 626 , 365c (1997).
2) M. Wada et al.: RIKEN Rev. , No. 31, 56 (2000).
3) M. Wada et al.: Nucl. lnstrum. Methods Phys. Res. B
126, 386 (1997).
4) M. E. Poitzsch et al.: Rev . Sci. lnstrum. 67, 129 (1996).
5) K. Okada et al.: J. Phys. Soc. Jpn. 67, 3073 (1998).
6) K. Okada et al.: Jpn . J. Appl. Phys. 40, 4221 (2001).

RIKEN Accel. Prog. Rep. 35 (2002)

Optical detection of atoms and ions in superfluid helium
R. Saneto,*1 Y. Fukuyama, 1. Tanihata, Y . Matsuo , and Q. Hui*2
Superfiuid helium (He II) is expected to be a suitable medium to study short-lived nuclei because it can
instantly stop ions with high kinetic energy. I) Injectedions are trapped at a certain region of a He II chamber
determined by the initial energy of ions. Then, laser
spectroscopy can be applied to trapped atoms and ionsto determine the structure of these nuclei. Microwave
detection combined with the optical pumping method
will enable us to measure hyperfine splitting of alkali
and alkali-earth atoms and ions. 2,3) In order to perform
a laser spectroscopic study of unstable nuclei in He II,
it is necessary to develop a method of detecting an optical signal. In off-line experiments, laser ablation is a
useful method of implanting atoms and ions in He II.
We have reported that ions produced by laser ablation
were introduced into He II by applying an electric field
and the mobility of ions was measured. 4 ) In this report,
we describe laser-induced fluorescence (LIF) detectionof impurity atoms and ions, such as Ba, Ba+, and Sr,in He II.
The experiment was performed in a quartz con,tainer filled with He II of 1.6 K in a cryostat at saturated vapor pressure. Laser ablation with a Q-switched
Nd:YAG laser (355 nm, 10 Hz, 10 mJ) was carried out
above a liquid surface and produced ions were injected
into He II by an electric field generated at electrodes.
A detailed design of the cryostat and the electrodes is
described in Ref. 4. The schematic of optical detection
is illustrated in Fig. 1. For the excitation of implanted
atoms and ions in He II, a pulsed dye laser pumped

Optical windows

600 ,---------------------------------~
~

500

Ba

....

'§ 400

+

Ba

..ci

~ 300
~

.~ 200

....

II)

..5

100

o

~

____

480

_ L_ _ _ _ _ _~_ _ _ _~_ _ _ __ __ L_ _ _ _~

500

520

540

560

580

Wavelength [nm]Fig. 2. Emission spectra of Ba and Ba+ .

with an excimer laser was used. LIF signals were detected with a photomultiplier tube (PMT) through a
monochromator. The detected signals were amplified
and integrated by a boxcar averager.
Figure 2 shows the emission spectra of Ba and Ba + .
The wavelength of the dye laser for excitation (446 nm)
was set to the peak position of the D2 excitation lineof Ba + in He II. The lowest singlet transition line of
Ba and the D1 line of Ba+, which are in the typicalshape of lines in He II, were observed. 5 ) Furthermore,
we observed a number of lines of Sr and Ba.
The amount of ions injected into He II after the laser
ablation is estimated to be 108 from the ion current experiment. 4 ) Since the efficiency of our optical detection
system is about 10- 5 , the intensity of the Ba+ line in
Fig. 2 corresponds to emission from 10 3 ions. Therefore, in order to perform optical detection of short-lived
nuclei, 105 of ions would be required in the detection
region.
We are now constructing a new cryostat which has
a window for introducing ion beams into He II. It isnecessary to determine the position of implanted ionsfor the efficient observation of optical signals. The new
cryostat is designed to use hodoscopes that can detect
the position of unstable nuclei by observing beta-ray
emission.
References

Fig. 1. Schematic of optical detection.

*1*21) N. Takahashi et al.: Physica B 284/288, 89 (2000).
2) T. Kinoshita et al.: Phys. Rev. B 49, 3648 (1994).
3) T. Yabuzaki et al.: Z. Phys. B 98, 367 (1995).
4) R. Saneto et al.: RIKEN Accel. Prog. Rep. 34, 111(2001) .
5) B. Tabbert et al.: J. Low Temp. Phys. 109, 653 (1997).

Keio University
University of Electro-Communications

101

RIKEN Accel. Prog. Rep. 35 (2002)

Study of BaF 2 crystal by a positron annihilation technique
K. Inoue,* N. Suzuki, Y. Itoh , A. Goto, and T. Hyodo*
In the last decade, BaF 2 , which is widely used asa material for an ultra fast , -ray scintillator has attracted much interest. Its photoluminescence process
is Auger-free; the radiat ive transition of a valence electron to a hole created in the core level stimulated by
the excitation of the outermost core Ba2 + 5p level. 1 )In the present study, we measured t he positron lifetime spectra and the doppler broadening spectra in
BaF 2 in the temperature range of 14K- 295 K.
First, a two-component analysis of the lifetime spectra was performed. The results are shown in Fig. l.
The shorter lifetime component is attributed to the
mixture of para-positronium component and the component of the positron which does not form positronium. The longer lifetime is attributed to orthopositronium.
It is seen that in the temperature range below 90 K,
71, 72 and h are almost constant.
However, in the

.-,-•

•

........

t"m~.................

100

200

300

temperature (K)Fig. l. Positron lifetimes and intensities for BaF 2.

Graduate School of Arts and Sciences , Un iversity of Tokyo102

o.4'7r-----.-----r-----,...----r----.-----,
0.46~.98 0.46(~ 0.46-'

tf)

0.46~

100
200
temperature (K)300

Fig. 2. S-parameter for crystalline BaF2.

range above 100 K , 71 and 72 decrease and h increases
as temperature rises. In the temperature range between 90 K and 100 K , 71 , h and the mean lifetimechange almost step-likely, and 72 starts to decrease.
Figure 2 shows S-parameter, which is defined as thenumber of counts of the central region of the Dopplerbroadened 511 ke V annihilation , -ray energy spectrum
divided by the total number of counts. There is a
sharp drop in the temperature range 90 K- 100 K. Thischange correlates well with the result of the positron
lifetime.
Such step-like changes in the positron annihilation
parameters indicate the existence of a phase transitionof BaF 2 or a change in the state of positronium.
An interesting phenomenon possibly related to our
result is reported by Ejiri et al.!) They measured thephotoluminescence spectra in BaF 2 and found that thephotoluminescence excited at 23 K is much different
from that at room temperature, and explained that theintensity of self-trapped exciton increases with cooling.
They also found that the intensity of the photoluminescence of the self-trapped exciton becomes maximum
at around 95 K. However , they measured the photoluminescence spectra at only five temperatures; 23 K ,54 K , 95 K , 130 K and 300 K. It is not certain that the
maximum is in the range of 90 K- 100 K.
It is desirable to measure the temperature dependence of various physical parameters of BaF 2 withsmall temperature steps by various experimental techniques.
References
1) A. Ejiri et al.: J. Electron Spectrosc. Relat. Phenom.
79 , 151 (1996).

RIKEN Accel. Prog. Rep. 35 (2002)

Temperature dependence of the Compton profile for BaF 2 crystal
K. Inoue,*1 N. Suzuki, N. Hiraoka,*2 M . Itou,*2 Y. Sakurai,*2 Y . Itoh, A. Goto, and T. Hyodo*I
In the previous paper, 1) we reported that theposi tron annihilation parameters for BaF 2 showed aclear step-like change in the temperature range 90 K100 K, and that this indicated the existence of a phasetransition.
Although the positron annihilation technique ishighly sensitive to various phase transitions (e.g.,
structural phase transitions, spin crossover transitions,
glass transitions, and so on) , it is usually difficult to
identify the origin of the transition using only the
positron annihilation parameters. Thus it is useful
to combine this technique with other complementary
techniques.
In this study, we measured the temperature dependence of the electron momentum distributions in
BaF 2 using a high-resolution Compton scattering technique. The measurements of Compton profiles were
performed at the beam line BL08W of the SPring-8
facility. A monochromatized 116 keY incident X-ray
beam was scattered at an angle of 172°, dispersed bya Si[620] analyzer, and detected by a high-purity Ge
detector. The momentum resolution was 0.15 atomic
units (a.u .).
The results are shown in Fig. 1. The solid circles
in (a) represent the Compton profile for BaF 2 at 85 K
and the open triangles represent that at 110 K. Figure 1 (b) shows the difference between the two spectra.
There is a slight difference beyond the statistical error
in the central part of the spectrum (within ±2. 5 (a.u.)).
This result probably corresponds to the result of thepositron annihilation measurements and evidences theexistence of a phase transition between 85 K and 110 K.
The difference in the Compton profiles is observed
only in the central region. It suggests that this phenomenon is caused by the change of the electronic stateof the valence band (2p of F-), because the momentum
distribution of the valence electrons is narrow . For example, the covalency of the chemical bonding between
Ba and F atoms might change between 85 K and 110 K.
The change in the Compton profiles is somewhat unclear as is apparent in the positron annihilation parameters. I ) This is probably because the sensitivity to thechanges of the valence electrons differs . The amplitudeof the positron wave function is large in the intersti-

*1
*2

(a)

-4

.:
.6.:

85K
IIOK

-2
0
2
momentum (a. u.)

4

Fig. l. (a) Compton profiles for BaF 2 at 85 K (solid circles)
and 110 K (open triangles). (b) The difference between
the above spectra.

tial region because of the repulsive force between thepositron and the nuclei. Thus, positrons are sensitive
to the changes of the valence electrons. The Compton
profiles represent the momentum distributions of all of
the electrons in a material. Thus the Compton profiles
are relatively insensitive to the change of the valence
electrons.
In order to clarify this point, we are also continuing
to investigate the temperature dependence of BaF 2 byother techniques .
The measurements of Compton profiles were performed at the SPring-8 facility with the approval of
the Japan Synchrotron Radiation Institute (JASRI)(Proposal No. 2001B0231-ND-np) .
References
1) K. Inoue et al.:(2002).

RIKEN Accel. Prog. Rep . 35, 102

Graduate School of Arts and Sciences, University of TokyoJapan Sync rot ron Radiation Research Institute (JASRI) ,SPring-B

103

RIKEN Accel. Prog. Rep. 35 (2002)

J-tSR study of the Cu-spin dynamics In La2-xSrxCUl-yZny04
I. Watanabe , T. Adachi ,* K. Takahashi,* S. Yairi ,* Y. Koike, * and K. Nagamine

A magnetically ordered state of Cu spins appearing
at low temperatures in La-based high-Tc superconductors around the hole concentration of ~ ~ per Cu 1) is
now recognized to be a statically stabilized state of the
dynamical stripe correlations of spins and holes. Thisstabilized state has been argued to lead to the suppression of superconductivity.2) Meanwhile, it has been reported by Koike et al. 3 ) that the superconducting statein La2-xSrxCUl-yZny04 (LSCZO) around x = 0.115
is strongly suppressed by only 1% Zn substitution for
Cu also. These results suggest that the Zn substitution affects the stabilization of the dynamical stripe
correlations. Thus, in order to clarify the effect of thenon-magnetic impurity, Zn, on the dynamics of the dynamical stripe correlations, muon spin relaxation measurements on the Zn-substituted LSCZO with x = 0.13
were carried out at the RIKEN-RAL Muon Facility,
while changing the Zn concentration from y = 0 to
0.10.
Figure 1 shows the time dependence of the asymmetry parameter of the muon-spin polarization, A( t),(p,SR time spectrum) of LSCZO with y = 0, 0.01,
0.05 and 0.10 at various temperatures. Figure 2 shows
the detailed temperature dependence of the time spectrum of the Zn-substituted LSCZO with y = 0.01 displayed in a short time region from 0 to 2 p,sec. In the

;>,

b
v

E
E
;>,
r;/)

-<
"0
V

.~

c;
E
1-0

1.0

Z

0.5

0

0
1.0
0.5

o

'--'-~~--L-....~~---"

o

5

10

Time (p,sec)
Fig.!. Zero-field j..LSR time spectra of the Zn-substituted
La2- xSrxCUl - yZny04 with x = 0.13 andy = 0, 0.01,
0.05 and 0.10 obtained at various temperatures.
Graduate School of Engineering, Tohoku University

104

;>-,

1.5

bQ)

La2_xSrxCUI_~ny04

§

•0
{),

x=0.13 , y=O.OI

0

2K
5K
8K
15K

;>-,

f/J

-<

"0
Q)

.~

c;

0.5

E
0

z

0
0

1

2

Time (p,sec)Fig. 2. Temperature dependence of the zero-field j..LSR time
spectra of the Zn-substituted La2-xSrxCUl-yZny04
with x = 0.13 and y = 0.01 within the early time range
from 0 to 2 j..Lsec.

Zn-free sample, the time spectrum does not change
so much, showing a Gaussian-type behavior down to
2 K , indicating no influence of the Cu moments at themuon site, that is , the Cu spins are in a paramagnetic
state. In the case of the Zn-substituted LSCZO with
y = 0.01, a fast depolarizing component appears at low
temperatures below about 10 K and the time spectrum
changes to an exponential type, and finally the muonspin precession is observed at 2 K , as shown in Fig. 2.
The muon-spin precession is no longer observed evenat 2 K in the Zn-substituted LSCZO with y = 0.05.
Solid lines in figures are the best-fit results obtainedusing the analysis function of Aoe- Aot + A1e- A1t +A 2 e- A2t x cos (wt + ¢).
The observation of the muon-spin precession in the
Zn-substituted LSCZO with y = 0.01 at 2 K clearly
indicates the appearance of a long-range magneticallyordered state of Cu spins. This means that the dynamically fluctuating stripe correlations are staticallystabilized by only 1% substituted Zn, forming a longrange ordered state. In contrast, the disappearance ofthe muon-spin precession at y = 0.05 means the destabilization of the statically ordered state of the stripe
correlations, that is, the magnetic correlation among
Cu spins tends to be destroyed by the Zn substitution
for y > 0.01 .
As a result , the present p,SR study confirms that asmall amount of non-magnetic impurities tends to pin
and statically stabilize the dynamical stripe correlations but a large amount of non-magnetic impurities
destroys the stripe correlations themselves.
References
1) 1. Watanabe et al.: Hyperfine Interact. 86 , 603 (1994).
2) J. M. Tranquada et al. : Nature 375, 561 (1995).
3) Y. Koike et al.: Solid State Commun. 82, 889 (1992).

RIKEN Accel. Prog. Rep. 35 (2002)

Isomer effect on charge transfer from C 3 H4 molecules(allene and propyne) at ke V energies
T. Kusakabe,*l 1. Shimamura, and M. Kimura*2
Our understanding of charge transfer processes incollisions of ions and hydrocarbons above intermediate
collision energies has been extremely limited due to thecomplexity of the target. However, it becomes increasingly important in a number of applications such as
those in plasma, material, medical and astrophysicalsciences.
For hydrocarbon molecules, as the number of carbon atoms increases, in general, the number of isomers increases. The C 3 H4 molecule is known to possess
two stable isometric molecular structures, i. e., allene(propadiene; H 2C=C=CH 2) and propyne (methylacetylene; HC=C-CH 3 ). It has been known that isomers
always show conspicuous differences in various physical and chemical properties in stationary, or dynamical aspects in the interaction energy equivalent to thethermal energy domain. However, as a natural consensus, it has been assumed that the isomer effect rapidly
disappear as the collision energy increases above, say,
50 eV regime because of a shorter interaction time andhence, has entirely been ignored in experimental ~tud­ies in the past. Therefore, it would be interesting toinvestigate this phenomenon to determine the degreeof the effect on charge transfer depending upon themolecular structure of the isomers.
We have observed, for the first time, prominent isomer effects in charge transfer processes in collisions of
C+ ions with allene and propyne even at a collision energy as high as 1000eV.1) The present charge-transfer
cross sections of allene are found to be systematicallylarger than those of propyne in the entire energy range
studied up to 4.5 keY. In order to understand the details, we have carried out a theoretical analysis basedon the DV-Xa method 2) for molecular states and asemiclassical molecular orbital close coupling approachfor scattering dynamics.
The specific processes we have studied are collisionsof the ground-state C+ (2P) ion with the allene andpropyne (C 3 H 4) molecules:

C+ep) + C3 H4 (Vi = 0)---+ Cep)+ C3 H4 +(vf) + 0.90eV for propyne,(1)C+ep) + C 3 H 4 (Vi = 0)---+ Cep)+ C 3 H4 + (vf) + 1.57 eV for allene, (2)12,.-...
M

S

10

()

'='
x

..8=
()

<l)

CI:l
CI:l
CI:l

0

....

U

Energy (ke V)

Fig. 1. Charge transfer cross sections for C+ -C 3 H4 (allene
and propyne) collisions. 0; the present data for allene,
0 ; the present data for propyne. The experimental error bars denote the absolute total uncertainty. Theoretical results for allene and propyne are included in solidand dot lines, respectively.

quantum numbers, respectively, of a target molecule.
The present experimental charge-transfer cross sections are shown in Fig. 1 for allene and propyne from
0.2 to 4.5 keY along with the present theoretical results. Experimental charge-transfer cross sections ofallene are consistently larger than those of propyne in
the entire energy range studied, but the difference between these two sets of cross sections becomes more
pronounced with the collision energy below 0.4 keY.
The difference between these two sets of the crosssection is 32.5% and 21.7% at 0.2 keY and 0.3 keY,
respectively, and these values are much larger thanthe present total absolute experimental uncertainty of
14.6%. Therefore, the difference in the two sets ofcross sections in the isomers is confirmed at least at
the two lowest energy points. The t rend of the twocross sections of calculated results, although the absolute magnitude is somewhat larger than the measured
one, is found to be consistent with that of measured
results, and supports our observation.
References
1) T. Kusakabe et a l.: Phys. Rev. A 62, 062714 (2000).
2) M. Kimura and N. F. Lane: in Advances in Atomic
Molecular and Optical Physics, Vol. 26 (Academi~
Press, New York, 1989), p. 76.

where Vi and vf denote the initial and final vibrational*1*2

Department of Nuclear Engineering, Kinki University
Graduate School of Science and Engineering, Yamaguchi
University

105

RIKEN Accel. Prog. Rep. 35 (2002)

Microwave resonances in the hyperfine structure of antiprotonic
helium and deduction of the antiprotonic orbital magnetic moment
E. Widmann,*l J. Sakaguchi,*l H. Yamaguchi,*l T. Ishikawa,*l R. S. Hayano,d J. Eades ,*2 M. Hori,*2
H. A. Torii ,*3 B. Juhasz,*4 D. Horvath,*5 and T. Yamazaki
Following the discovery of a doublet splitting in thelaser resonance transition (n, l) = (37, 35) ---+ (38,34)
in antiprotonic helium (pHe+)l) and the theoretical study of the hyperfine structure by Bakalov andKorobov,2) an experiment to determine the quadruplet structure (see Fig. 1) using two laser pulses andone microwave was carried out during 2001 at the Antiproton Decelerator at CERN. The first laser pulse
was used to induce an asymmetric population of theF = l ± 1/2 doublet whose time evolution caused by
microwave transitions was detected by the second laser
pulse. Two microwave resonance transitions (electron
spin flipping with respect to the large orbital angularmomentum (l = 35) of p) were observed as predicted ,as shown in Fig. 2. The observed frequencies are
12.89624 ± 0.00019 and 12.92430 ± 0.00018 GHz (preliminary), in excellent agreement with the predictedfrequencies. 2) The precision achieved in this first experiment is ~ 1 X 10- 5. Since the experimental values
agree with two independent theoretical calculations recently performed,3- 5) they provide experimental proof

0.84
0.82
0.8
0.78
:i
.ti

S
+
+

0.76
0.74

II:

0.72
0.7
0.68
12.87 12.88 12.89 12.9 12.91 12.92 12.93 12.94 12.95
MW frequency (GHz)

Fig. 2. Observed microwave resonance profile in the twolaser-microwave triple resonance method.

of the fundamental relation concerning the antiprotonic orbital g-factor and the anti-nuclear magneton

F'zL'-1/2

J-+mL

tv

SHF-

to the precision of --1 x 10- 5. Note that no experimental value is known for either gl(p) or f..LN (nuclear
magneton) for the proton because no such orbiting proton exists in the matter world .

J-=L-1
V

+

HF

v~F

f+

VHFJ++= L+1
F'"-L+1/2

tVSHF+

r-L

Fig. 1. Hyperfine structure of the antiprotonic helium andvarious transitions.

*1

*2

*3
*4
*5

106

Department of Physics , University of TokyoCERN , Switzerland
Institute of Physics , University of Tokyo
Institute of Nuclear R esearch of the Hungarian Academy of
Sciences , Hungary
KFKI Research Inst itute for Particle and Nuclear Physics,
Hungary

References
1) E. Widmann et al.: Phys. Lett. B 404, 15 (1997).
2) D. D. Bakalov and V. I. Korobov: Phys. Rev. A 57,
1662 (1998).
3) V. I. Korobov and D. Bakalov: J. Phys. B 34, L519
(2001).
4) N. Yamanaka, Y. Kino, H. Kudo, and M. Kamimura:Phys. Rev. A 63, 012518 (2001).
5) Y. Kino, N. Yamanaka, H. Kudo, and M. Kamimura:
to be published.

3. Radiochemistry and Nuclear Chemistry

RIKEN Accel. Prog. Rep. 35 (2002)

In-beam Mossbauer study on valence states of 57Fe decaying from
57Mn implanted into KMn04 (II)tY. Kobayashi, M. K. Kubo,*l Y. Yamada,*2 T. Saito,*2 H. Veno, H. Ogawa,*3 W. Sato, K. Yoneda,
H. Watanabe, N . Imai,*4 D. Kameda,*5 H. Miyoshi, and K. Asahi
Applications of 57Mn, which is one of Mossbauer
source nuclides for 57Fe, are quite rare because its halflife (Tl/2 = 1.45 min) is short. Mn occurs in various
stable oxidation states up to 7+ in solids, which is not
the case for Fe and Co. Therefore, Mn is considered
to be one of the most attractive probes in solid-statechemistry to investigate the chemical states after nuclear transformations.
We have succeeded in obtaining well-resolved inbeam Mossbauer spectra of 57Fe arising from 57Mn implanted into KMn04 between 11 K and 155 K. 57Mn
particles were produced as a RI beam following thenuclear projectile fragmentation of a 59Co beam (E =80 A MeV) with a Be target using RIPS , and subsequently implanted into a sample of KMn04 , inwhich Mn ions are in a 7+ state and form symmetric [Mn04]- tetrahedra. A typical 57Fe( f - 57Mn)
Mossbauer spectrum of KMn04 at 11 K is shown in
Fig. 1. The obtained spectra below 90 K could be analyzed as having two components of a doublet and asinglet at least. The doublet was assigned to Fe 2+
ions located interstitially or substituted for K-sites in
KMn04 from the derived Mossbauer parameters.
Suppose that the anomalous singlet resulted in the
Fe atoms substituting for regular Mn-sites in symmetric tetrahedra. Molecular orbital calculations (DV-XQ

en

108

'E

:J

o

o
104
'0
Q)

.!:::!

(ij

E
o 100

z

-4

-2

o

2

4

Velocity (mm/s)

Fig. 1. A 57Fe( f-- 57Mn) Mossbauer spectrum of KMn04
at 11 K.

*1

*2
*3
*4
*5

Condensed from the article in J. Nucl. Radiochem. Sci., inpress
School of Science, University of Tokyo
Department of Chemistry, Tokyo University of Science
National Institute of Advanced Industrial Science and Technology (AIST)
Graduate School of Science, University of Tokyo
Graduate School of Science and Engineering, Tokyo Institute of Technology

en 6.2

c

o

"-

+-'

~

~ 6.0

CD

~ulliken

"'C
('I')

-o 5.8
c

o

§ 5.6
:J

a.
o

Cl..

DV-Xa

5.4
234

5

6

7

8

9

Valence of Fe
Fig. 2. Calculations for the population of 3d electrons
against the valence states of Fe.

and G98) were carried out to determine the electron
densities of Fe atoms in tetrahedral [Fe04]n-. The G98
calculation reveals that two species of [Fe04j2- (Fe 6 +)and [Fe04]O (Fe 8 +) are the most stabilized tetrahedra,and that in these species the Fe atom is located in symmetric oxygen configurations. The other Fe n + atoms
do not form stable tetrahedra of [Fe04]n - geometrically. The results of G98 calculation are consistent
with the shape of the singlet, that is , the electric field
gradient obtained in the Mossbauer spectra is zero.
The nature of the Fe-O bond tends toward covalentfrom ionic with increasing valence state of Fe, therefore , the contribution of 3d-electrons to bonding orbitals increases, while that to antibonding orbitals decreases. Although the total population of 3d-electrons
decreases as the number of antibonding electrons decreases in the region from Fe 2+ to Fe 6 +, the population of 3d-electrons increases because of the covalentcharacter in the region between Fe6 + and Fe 8 +, fromthe calculations based on the different modes (NPA,
Mulliken and DV-XQ) , as shown in Fig. 2. Therefore,
the isomer shift of [Fe04j2 - corresponding to Fe 6 + appears to have a maximum value, while that of [Fe04]O
with a higher valence state is considered to be less thanthe value corresponding to Fe 6 +. On the basis of the
Mossbauer parameters and the molecular orbital calculation, it is concluded that the singlet is assigned
to the 57Fe atoms substituting at Mn-sites in tetrahedral [Mn04]- with an unusually high valence state ofFe(VIII).

107

RIKEN Accel. Prog. Rep. 35 (2002)

Stimulation of transferrin-dependent 59Fe and 48V uptake in rat
isolated adipocytes by insulin or vanadyl treatment
H. Yasui,* K. Kawabe,* A. Nakayama,* R. Hirunuma, S. Enomoto, and H. Sakurai*
The biological actions of vanadium have been investigated by many researchers. Since vanadium ions,such as vanadyl (Y02+) and vanadate (Y0 3 -), havebeen demonstrated to normalize blood glucose levelsof diabetic animals and patients, the insulin-mimetic
mechanism of vanadium treatment has attracted muchinterest. However , a few studies on the mechanisms of
biological actions in vanadium treatments have beenreported.
Insulin has been demonstrated to stimulate thetranslocation of transferrin receptors from an intracellular compartment to the plasma membrane, and subsequently the accumulatio'n of iron (Fe) in adipocytes,
by increasing the binding and uptake of diferric transferrin. 1) This insulin-dependent stimulation is basedon an intracellular signaling mechanism similar to therecruitment of glucose transporters. Recently, theinsulin-mimetic effect of the vanadate ion on transferrin receptors and Fe uptake in rat adipocytes was
examined in order to determine its function in thetranslocation of glucose transporters as an acute biological response. 2) Thus, we first planned to study themechanisms of the vanadyl ion in a major oxidation
state in animals , which is less toxic than the vanadateion, as well as insulin in terms of stimulating uptake of
59Fe and 48y bound to transferrin in rat adipocytes.
A multitracer technique was used to investigate thevanadyl- or insulin-stimulated uptake of trace elements
in rat isolated adipocytes. A multitracer solution containing the radioisotopes of 20 elements was preparedfrom a silver target irradiated by a heavy-ion beamof 135 MeY /nucleon accelerated by the RIKEN Ring
Cyclotron. Male Wistar rats (200 g of body weight,
7 weeks old) were used in this study. Isolated rat
adipocytes (2.7 x 106 cells/mL) prepared as described 3 )were preincubated at 37°C for 0.5 hr using three different concentrations (lor 5 x 10- 4 , and 1 x 10- 3 mM) of
vanadyl sulfate or 4 nM insulin in 1 mL of KRB buffer(pH 7.4) containing 20 mg of bovine serum albumin .
The multitracer solution dissolved in a physiologicalsaline containing bovine apo-transferrin (Tf) was thenadded to the reaction mixture and the resulting solutions were incubated at 37°C for 2 hr , where a final
concentration of Tf was 2 mg/mL. The reactions were
terminated by soaking in ice water and the mixtures
were centrifuged at 12,000 rpm for 1 min. After the solution surrounding the cells was aspirated, the radioac-

Department of Analytical and Bioinorganic Chemistry,
Kyoto Pharmaceutical University

108

"V

'·Fe

**

control

InsulinV-low

V.-mldV-hlghcontrol

Insulin

Votow

V·mld

V-hlghFig. 1. Uptake ratios of 59Fe and 48y in each cell preparation at 2 hr after an addition of the multitracer solution in the cell suspension treated with insulin (4 nM)
or vanadyl sulfate (V-low; 1 x 10- 4 , V-mid; 5 x 10-4,
V-high; 1 x 10- 3 mM), and in the untreated cell suspension (control group). Data are expressed as means±SD for 3 preparations. Significance level: *p < 0.05
and **p < 0.01 vs. control group.

tivity levels in the cells were measured by ')'-ray spectrometry (Ortec GEM, ParkinElmer). The observed')'-rays were analyzed in terms of their energies andhalf-lives. In this study, we focused on the data of
59Fe and 48y . Their uptake rates (% dose/2.7 x 106
cells) were calculated.
The mean uptake ratios of 59Fe and 48y, both ofwhich were bound to apo-transferrin, were determinedin adipocytes of each group . The uptake ratios ofboth elements increased with the stimulation of insulin, however, the ratios were not significantly different between the control group and the vanadyl-treatedgroup (Fig. 1).
These results indicate that the vanadyl ion treatment nearly stimulates the translocation of transferrin
receptors from the cytosol to the plasma membrane in
rat adipocytes as well as that of glucose transporters ,suggesting the importance of roles of the vanadyl ion
other than as glucose transporters in adipocytes .
References
1) L. I. Tanner and G. E. Lienhard: J. BioI. Chern. 262 ,
8975 (1987).

2) S. Tang, B. Lu, and I. G. Fantus: Metabolism 47, 630(1998) .

3) M. Nakai , H. Watanabe, C. Fujiwara, H. Kakegawa, T.
Satoh, J. Takada, R. Matsushita, and H. Sakurai: BioI.
Pharm. Bull. 18, 719 (1995).

RIKEN Accel. Prog. Rep. 35 (2002)

Abnormal metabolism of trace elements in mouse caused byZn-deficiency during the growth period
T. Ohyama,*1 M. Yanaga,*1 H. Maetsu,*l M. Noguchi,*2 H. Suganuma,*l K. Ishikawa,*2 R. Hirunuma,
S. Enomoto, and T. Omori*lZinc is a very important element in terms of health.
More than 300 different enzymes in the body dependon Zn to work properly. Recently, loss of the taste inyoung generation caused by Zn-deficiency is increasingin Japan.
In our previous works, abnormal metabolisms of Zn
and other trace elements, such as Co, Fe and Mn, in
addition to various symptoms were observed in Zndeficient mice. 1) Furthermore, we also found a correlation between Zn and Co concentrations in the liver ofmice fed with a Zn-deficient diet during the growth
period. 1) However, details of the mechanism of thechange in metabolism of Zn and Co during the growth
period have not been clarified yet. Therefore, in thepresent work, we investigated the behavior of Zn andother trace elements in mice fed with a Zn-deficient
diet during the growth period after weaning using
the multitracer technique. We compared the resultswith those for the adult mice fed with the Zn-deficient
diet 2,3) in order to obtain more knowledge regarding
the functions and interdependencies between Zn andother trace elements in growing organisms.
Three-week old· (growing mice) and 8-week old(adult mice) male mice of the ICR strain were divided into two groups; one group was fed with theZn-deficient diet and distilled water (Zn-def. mice),and the other group was fed with the control dietand distilled water (control mice). After 3 weeks ofthis treatment, a multitracer solution, which was prepared from an Ag target, was orally administered or
intraperitoneally injected into each mouse. Six, 24 and72 hours after administration, various organs and tissues, such as the liver, kidney, pancreas, testis, bone,
and intestine were removed and subjected to gammaspectrometries. The oral administration method (oral)
is suitable for determination of the amounts of administered trace elements absorbed through the small intestine and their distribution in the organs and tissues. On the other hand, total amounts of trace elements are absorbed when the intraperitoneal injection
method (i.p.) is adopted. Therefore, results obtainedusing the second methods will reflect only the distribution of trace elements in the body after injection.
When the multitracer solution was orally administered to the growing or adult mice, Zn and Co uptake
levels in several organs and tissues of Zn-def. mice werehigher than those of control mice . This suggests that
*1
*2

~

0
"0

tfi.
~

~

0..

IO~ IOE]
~
rr

1

oral

i.p.

-1

1 .~

Q

-~

0.1

0.1

~ 0.010.01

o50Time (h)

100

o

50

100

~---

-0-

Zn-def. mice (Zn)-to-Control mice (Zn)

~ Zn-def. ffil=·~
ce=-(:>..::C:..::
o.!...
) ___-+----=-Co.::.::n~tr:..::o~l==ffil.::.::·c..::..e...o.(C~o::..c)----1

Fig. 1. Zn and Co uptake levels in bone of growing mice
after oral administration and intraperitoneal injection.

Co uptake from the small intestine increased with anincrease in the Zn uptake level. On the other hand,when injected intraperitoneally, such a significant enhancement of Zn and Co uptakes was not observed. On
the contrary, as shown in Fig. 1, the Zn uptake levelsin the bone and pancreas of Zn-def. growing mice werelower than those of control growing mice. This trend
agrees with the results for IN AA.1) The Zn concentrations in the bone and pancreas of Zn-def. growing mice
were much lower than those of control growing mice.
The INAA data indicated that Zn, which had accumulated in the bone and/or pancreas, was transported toother organs and tissues of Zn-def. growing mice which
required more Zn to support their functions.
The Mn uptake levels in the liver and all the otherinvestigated organs and tissues of growing mice weresignificantly higher than those of adult mice. Feureand Joel reported that the absorption levels of Mn inyoung animals were higher than those in adult animals, generally because of incomplete maturation of
the intestine walls in young animals. 4 ) This may be
one of the reasons for the increase in Mn uptake levels
in growing mice.
References
1) M. Yanaga et al.: J. Radioanal. Nucl. Chern. 231, 187(1998); J. Radioanal. Nucl . Chern. 243 , 661 (2000); J.
Radioanal. Nucl. Chern. 245, 255 (2000).
2) T. Ohyarna et al.: RIKEN Accel Prog. Rep. 34, 142(2001).
3) T. Ohyama et al.: J. Radioanal. Nucl. Chern. in press.
4) M. E. Le Feure and D. D. Joel: Life Sci. Stal. 28, 96(1977) .

Faculty of Science, Shizuoka University
Department of Biology and Geosciences, Faculty of Science,
Shizuoka University

109

RIKEN Accel. Prog. Rep. 35 (2002)

Brain regional uptake of trace elements In normal mice
during development
T. Tarohda,*1,*2 Y. Yabushita,*3 Y. Kanayama,*3 R. Amano,*3 and S. Enomoto
The knowledge of the function and metabolic beFigure 1 compares the regional uptake rates in thehavior of trace essential elements in a variety of brain
ST, CC, CB, HI, TH and MP of the brains of normal
regions is of great importance. Through studying the1-, 4-, 8-, and 21-day-old mice 48 hours after the i.p.
physiological and biochemical roles of essential eleinj ection. Of all the age groups examined (1-, 4-, 8-,
ments, a dramatic metabolic change can be described
21-, and 56-day-old), the regional uptake rates of Mn,
during the development of the brain. In the previous
Zn and Se were highest in 1-day-old mice. In comstudy, the brain uptake behavior of Mn, Zn and Se wasparison to the regional uptake rates of Zn and Se, theexamined. They showed that uptake rates in 1-day-old
Mn regional uptake rates were higher in 1-day-old to
mice were higher than those in 4-, 8-, 21-, and 56-day8-day-old mice for all brain regions, although the conoId mice, and the uptake of Mn was higher than that
centration of Mn is normally much lower than that of
Zn in the brain. Mn concentration in I-day-old mouseof Zn and Se for I -day-old to 8-day-old mouse brains.
In the present work we focused on the brain regional
brains is much lower than that in 21-day-old mouseuptake of Mn, Zn and Se during the developmental
brains, and Mn concentration in the brain rapidly instage, that is 1 day to 21 days.
creased with growth in 1- to 21-day-old mice. These
Twenty normal ICR mice were used for this exresults suggest that Mn is crucial during the earlier
periment. The mice were classified into four groups
stages of development. An interesting contrast is that
according to age (1-, 4-, 8-, and 21-day-old mice).
in the all regions of the 21-day-old specimen , out of theAn appropriate amount of the multitracer solution
three elements , zinc had the highest uptake rate. In thewas inj ected intraperitoneally (i.p.) into each mouse
21-day-old hippocampus, it was found that the highest(0.1 ml/5g mouse weight) . The mice were sacrificed
trace uptake had changed from Mn to Zn (called theand perfused with 0.9% N aCl solution under ether"turning point"), and moreover , the Zn uptake rates
anesthesia 48 hours after the i.p. inj ection. The samincreased in 8-day-old to 21-day-old mice . These resuIts suggest that the role of Zn is crucial in the later
pIes were divided into six regions; striatum (ST), cerebral cortex (CC), cerebellum (CB), hippocampus (HI),stages of development in the hippocampus. The turnthalamus plus hypothalamus (TH) and midbrain plus
ing point at 21 days underlines the shift in the respecpons plus medulla oblongate (MP). The uptake behavtive roles of Mn, Zn and Se elements during developior was evaluated in terms of the regional uptake rates
ment, particularly as seen in the hippocampus.
(% dose/g).
St riatum
Cerebral Cortex
H ippocam pus
10 0

100

~4Mn
10

"..

--

-

65Z n

-

=

r..

~Lr
75Se

0.1
10
20
A ge (day)1020
Age (day)30

Midbrai n. Pons . Med ulla Oblongate

100

~54Mn

-;0

~

30

Thalam us.H ypothalam us

1 00

'Q;

0.1
10
20
Age (d oy)

30

Ce r ebel lum

10

65Z n
10

_I

E

"-

j

65Z n

10

~

"""!- I--75S e

0.1

0.1
10

20

30

A g. (d a y )20

10Age (day)

30

20

10

30

Ag. (day )Fig. 1. Brain regions uptake rates of 54Mn, 65Zn, and 75Se in normal 1-, 4- , 8- , and 21-day-old mice 48
hours after i.p. injection of multitracer solution. Date is expressed as means ± S.D. (n = 5).
*1
*2
*3

110

Graduate School of Natural Science and Technology,
Kanazawa University
Asanogawa General Hospital
Faculty of Medicine, Kanazawa University

RIKEN Accel. Prog. Rep. 35 (2002)

Brain regional tracer uptake and elemental concentrationin mice fed Zn-deficient and -excessive diets
Y. Yabushita,*1 Y. Kanayama,*1 T. Tarohda,*2 R. Amano,*1 and S. Enomoto
Zinc (Zn) is a cofactor of many proteins distributed
among all enzyme classes and has diverse functions inbrain homeostasis. I) Lack of Zn was shown to resultin poor growth, alopecia, and anostosis,2) and its excess intake leads to toxicity. It is thought that these
symptoms are caused by various element (Zn)-element(others) interrelationships rather than by the influenceof the single Zn element. In this work, we examined thebrain regional tracer uptake and the elemental concentration in mice fed Zn-deficient and -excessive diets inorder to obtain some information about element (Zn)element (others) interrelationships.
Dam ICR mice were fed Zn-deficient (1) (Zn concentration: O.7ppm) , Zn-deficient (2) (3.6ppm), Znadequate (36.0 ppm) or Zn-excessive (3520 ppm) dietsand pure water from the 16th day of pregnancy. Natal mice pups were nurtured to three weeks and bredwith their dams. Three-week-old weanling male mice(n = 5) were used for the experiment. It was difficult
for the mice to survive in the Zn-deficient (1) state;
only one mouse survived. The multitracer solution was
intraperitoneally (i. p.) injected into the mice. Fortyeight hours after i. p. injection, the brain was excisedand dissected into eight regions. Each of the eight regions was weighed and freeze-dried immediately. The
dried samples were measured using l'-ray spectra witha high-purity Ge detector and evaluated in terms of"brain regional uptake rate (% dose/g)." Identicalsamples were analyzed using instrumental neutron activation analysis (INAA) and evaluated. As a result,the multitracer solution enabled the simultaneous tracing of 46Sc, 54Mn, 58CO, 65Zn, 75Se, and 83Rb in allbrain regions. Figure 1 shows the brain regional uptake
rates of 65Zn, 46Sc, 54Mn, 58CO, 75Se, and 83Rb in Zndeficient, -adequate, and -excessive mice. The 65Zn uptake rates of Zn-excessive mice were significantly lower
than those of Zn-adequate mice. However, all othertracers except for 65Zn of Zn-excessive mice were significantly higher than those of Zn-adequate mice. The
83Rb uptake rates of Zn-deficient (2) mice were significantly higher than those of Zn-adequate mice. Using
the INAA method, the concentrations of Zn in all brain
regions were determined. No significant difference inZn concentrations in each region was observed among
the four diet groups.
These findings suggest that Zn-deficient and-excessive states influence the tracer uptake rates except for 65 Zn, however, the Zn concentration in mousebrain is not influenced by the Zn concentration of diets.
References
1) J. R. Prohaska: Physiol. Rev. 67, 858 (1987).
2) R. M. Leach et al.: in Handbook of Nutritionally Essential Mineral Elements (Marchel Dekker, New York,
1997), p. 185.

o In-deficient (1) 0 In-deficient (2) • In-adequate III In-excessive
6.00 ,---,6;-;;;5---- - -- - - - - - - , 60.0 , - - - - - - - - - - - - , 6.00 , . , - - - - - - . . . . - - - - - - - - - - - ,Zn
46
54Mn _

SC~

40.0 r---- -n--r---- - - - - ---1 4.00 I--F--+---III------F-II-+-II-tlt--III--r=-,!o.f

4.00

~

o

~ 2.0020.0 I - - --.k-II-&-----,;:-n--=-l ~----1 2.00

~

0.00

0.0
CC

io

ST

III

HY MB CB PM OB.......II.J..1..L-.u..J..-w..uB..L.I.-.~1lJ 0.00

~1OLU..1--..

CC

ST

III

......I.J.J..LI..............L.U...IIUJ

L.l..1A1ILI..U.......~ILU....L-....

HY MB CB PM OB

CC ST HI HY MB CB PM OB
16.0 r=-::--- -- - -- - - --,1-----------l!I---_~---j12.0 I - - --¥-----.,.-----=-- - - : - : - - - - -..~

1.20

6.00

0.80

4.00 f---IlIt---fi---tI--D--IH 1-______--1111

0.40

2.00

'tI

';!.

0.00

0.00
CC

ST

m

HY MB CB PM OB

0.0~1SU..U...-..,c.u....iLLJ...L""""u...i1.J.L

CC

ST

m

HY MB CB

PM OB

~1IO.J.L.I"-"""""IL.I.LJ,..-..u~I.ll..LI-.u"""".L.U...ll1IIILI

CC

ST

m

HY MB CB PM OB

Fig. 1. Brain regional uptake rates of 65Zn, 46SC, 54Mn, 58CO, 75Se, and 83 Rb in Zn-deficient, -adequate,
and -excessive mice. CC: cerebral cortex; ST: corpus striatum; HI: hippocampus; HY: thalamus andhypothalamus; MB: midbrain; CB: cerebellum; PM: pons and medulla; OB: olfactory bulb. The
bar and the line represent the mean ±S.D. for five mice. Asterisks indicate significant differences(*p < 0.05 , **p < 0.01) for Zn-adequate mice.
*1*2

Faculty of Medicine, Kanazawa University
Graduate School of Natural Science and Technology,
Kanazawa University

111

RIKEN Accel. Prog. Rep. 35 (2002)

Subcellular distribution of trace elements in mouse brain regions
using the multitracer technique
Y. Kanayama,* T. Tsuji,* R. Amano,* and S. Enomoto
In our previous work, we have studied the subcellular distribution of several trace elements in the brain ,and then fundamental results regarding the distribution were used to determine biochemical or physiological functions of trace elements. I) To improve our experimental procedure, we divided the brain into smaller
regions such as the cerebral cortex (CC), hippocampus(HI), and corpus striatum (ST). In this study, we examined the subcellular distribution of several radioactive tracers in the brain regions of normal mice, particularly in the CC , HI, and ST.
Five normal male ICR mice (6 weeks old; bodyweight, 31- 34 g) were used in this experiment. A
multitracer solution obtained from RIKEN Ring Cyclotron was prepared as a physiological saline solution.
Twenty-four hours after the intraperitoneal (i.p.) injection of the multitracer solution, each mouse was perfused with a physiological saline under ether anesthesia. After excision of the brains, the CC, HI and ST
were removed from the brains and weighed immediately. Subcellular fractionation was performed according to the method of Haj6s. 2 ) Each region was homogenized in 3 ml an ice-cold 0.32 M sucrose solution containing 0.01 M Tris-HCI buffer solution at pH 7.0. The
nuclear fraction (NU) was obtained by centrifuging thehomogenates at 1,000 x g for 10 min. The remainder
was then divided into the supernatant fraction (SU)and the pellet by centrifuging at 15,000 x g for 30 min.
The pellet was resuspended in 1ml of 0.32 M sucrose
solution. The suspension was carefully layered over a
0.8 M/1.2 M sucrose concentration gradient, and thenultracentrifuged at 63 ,000 x g for 2 hr. Finally, particles were resolved into the following fractions: themyelinated axonal fraction (MY) at the 0.32 M- 0.8 M
sucrose interface, the synaptosomal fraction (SY) at
the 0.8 M- 1.2 M sucrose interface and the mi tochondrial fraction (MI) as the pellet. Each fraction was
freeze-dried, and then subjected to /,-ray spectrometry. The uptake behavior was estimated in terms of
relative subcellular fractional uptake rate (%).
As a result , the multi tracer method enabled simultaneous tracing of 46 Sc , 54Mn , 58Co , 65Zn , 75Se , 83Rb ,88Z r, I03Ru an d IOIRh . F'Igure 1 compares the rela-

School of Health Sciences, Faculty of Medicine, Kanazawa
University

112

58CO

46SC
%

1
"l°m
100%
80 %0 080% 54
•
.

60·~
40%
20%
0%

cw
cr

m

60% a M n 60-/.

40%
20%

0%
~

60%

40%

40%

':;:
ft

cr

m

~

~b

':~ II

100%
80%

60%

~

100%

m

100% a80%;§- ':

m

cr
7SSe

60%

cr

20%

0%

~

'

40%

~

65Zn

!f 100%80%

10080% c m

40%

cr

m

~

11'1
cr

m

~

m

ft

~II8Zr 100% I g 0 3 R U 100% 10lRh

80"10
60%

.

80%

60-1.

80%
60%

.

40%

40%

40%

20%

20%

20%

0%

0%

cr

m

~

cr

m

0%

ft

cr

Fig. 1. Relative subcellular fractional uptake rates (%) of
46SC , 54Mn , 58CO , 65 Zn , 75Se , 83 Rb , 88Z r, 103Ru, an d
101 Rh in the cerebral cortex, hippocampus and corpus
striatum. Abbreviations are defined as follows: SU,supernatant fraction; MY, myelinated axonal fraction;
SY, synaptosomal fraction; MI, mitochondrial fraction;
and NU, nuclear fraction.

tive subcellular fractional uptake rates in regions CC,
HI and ST. Based on the uptake rates of 54Mn 58Co
65Z nan d 75S e, It. was note d that these elements 'are ac-,cumulated in the SY from all the brain regions. 83Rb
is predominantly accumulated in the supernatant fraction. Based on the 54Mn uptake rate, the SY fractional
percentage of the HI is the highest among the brain regions studied. The subcellular distribution of 65Zn isvery similar to that of 75S e .
This subcellular fractionation technique describedhere is a useful and valuable tool for studies of chemical
speciation of trace elements in the brain.
References
1) R. Amano et al.: RIKEN Accel. Prog. Rep. 31, 126(1998).
2) F. Rajas: Brain Res. 93, 485 (1975).

RIKEN Accel. Prog. Rep. 35 (2002)

Lateral and sexual differences in concentrations of trace elements
in cerebral cortex of normal mice
Y. Kanayama,* Y. Yabushita,* R. Amano,* and S. Enomoto
There are few studies on the lateral and sexual
differences in the behavior of trace elements in thebrain. Recently, Panayi et al. examined the differencesin trace-element concentrations between normal and
Alzheimer's disease brains, and reported that there aredifferences between the right and left hemispheres ofsuch brains. 1) Diamond et al. reported that environmental enrichment induces formation of a thicker cortex in rats and sexual difference is observed as well. 2)
In the present work, we focused on the lateral and sexual differences in the concentrations of trace elementsin the cerebral cortex by a multitracer technique andinstrumental neutron activation analysis (IN AA).
A multitracer was prepared from an Ag target irradiated with 14N beam of 135 MeV /nucleon, which
was accelerated in the RIKEN Ring Cyclotron. Afterthe chemical separation of the target , the multitracer
solution for injection, which is a slightly acidic physiological saline solution (pH 2- 3), was prepared.
Six male and six female normal ICR mice (4 weeksold) were used in this experiment. Forty-eight hours after intraperitoneal injection of the multi tracer solution,
the mice were sacrificed and perfused with physiological saline under ether anesthesia. Each brain was dissected and divided into the left and right hemispheres,and then cerebral cortical sections of each hemisphere
were obtained (the obtained left and right cerebral cortical regions were in the same position). After immediate weighing and freeze-drying of the cortex samples, the radionuclides uptake behavior was evaluatedin terms of brain regional uptake rates (%dose/g).
Identical cerebral cortex samples were subjected to
INAA. The samples were irradiated for 2, 5, and40 min, using a pneumatic tube system connected tothe core Pn-3 site, the graphite thermal column TcPn site and the core Pn-2 site of the Kyoto University Reactor. The activities (24Na, 27Mg, 28AI, 38Cl,
42K , 56Mn , 65Z n , 82Br , and 86Rb) produced were measured by '"Y-ray spectrometry using detectors made ofhighly pure Ge, and then their concentrations were determined and expressed in fLg/ g wet weight.
The use of multitracer solution enabled simultaneous
tracing of the radionuclides 54Mn, 65Zn, 75Se, and 83Rb
in the cerebral cortex and accurate comparison of their
uptake behavior. Figure 1 shows the typical resultsof the uptake rates of 54Mn and 65Zn in the cerebral
cortices of the left and right hemispheres of the maleand female mice. From these results, the uptake rates
were comparable with those obtained in our previous

0.8 r - - - - - - - - : : - - ,
~
Q;

0.6

~

1.6

~t.2

~ 0.4
~

2.0

Q

~ 0.8

0.2

0.4

0.0

0.0

FL

FR

ML

MR

FL

FR

ML

MR

Fig. 1. 54Mn and 65 Zn uptake rates in the cerebral cortices
of normal mice (n = 6 for each group). Abbreviations
indicate as follows: FL, female-left cortex; FR, femaleright cortex; ML, male-left cortex; MR, male-right cortex .

0.8

24

Mn
0.6

18

~

~

~ 0.4

~ 12

0.2

6

0

0

FL

FR

ML

MR

FL

FR

ML

MR

Fig. 2. Concentrations of Mn and Zn in the cerebral COftices of normal mice (n = 6 fOf each group). Abbreviations indicate as follows: FL, female-left cortex; FR,
female-right cortex; ML, male-left cortex; MR, maleright cortex.

studies. 3) It was found that there was no significant
difference in the cerebral cortical uptake rate of Mn
and Zn between the right and left hemispheres, and/or
between the male and female mice.
On the other hand, the concentrations of Na, Mg,
AI, Cl, K, Mn, Zn, Br, and Rb are compared for identical samples; typical results for Mn and Zn are shownin Fig. 2. The Mn and Zn concentrations were also inagreement with our previously obtained values. Moreover, no significant difference was observed between theleft and right hemispheres, and/or between the maleand female mice.
In the future, studies of subjects with a neurodegenerative disease that have a notable lateralization orsexual difference, the two techniques (multitracer and
IN AA techniques) are potentially useful tools for determining abnormal metabolism in their brains.
References
1) A. E. Panayi et al.: J. Radioanal. Nucl. Chern. 244, 205(2000) .
2) M. C. Diamond et al.: Behav. BioI. 14, 163 (1975).
3) Y. Yabushita et al.: RIKEN Rev., No. 35, 64 (2001).

School of Health Sciences , Faculty of Medicine, Kanazawa
University

113

RIKEN Accel. Prog. Rep. 35 (2002)'!race-element transfer from pregnant mice to the fetuses
T. Tsuji,* A. Kanbara,* R. Amano,* E. Hirunuma, and S. Enomoto

It is interesting to study the function of the placenta
as a barrier between the maternal body and the fetus,in which passage of nutrients, oxygen and waste between the maternal body and the fetus is regulated ina constant state. The fetus can accumulate and utilize essential trace elements through the placenta fromthe maternal body before birth. Enomoto et al. havestudied the placenta function by a multitracer technique. 1) In the present study, we also examined thequantitative uptake and retention of trace elements inthe placenta, fetus, and amniotic fluid using a multitracer technique, and focused on some trace elementsin the fetus immediately before birth.
A multitracer solution containing 13 radioactive isotopes (1Be 46SC 48y 54Mn 58CO 59Fe 65Zn 75S e
83Rb, 85Sr: 88Z r : 99Rh and l03Ru)' was ~repar~d ac~
cording to the method of Ambe et al. 2 ) Two sixteenday-pregnant CD-I (ICR) dams were used for thisexperiment . Multitracer physiological saline (0.1 ml)
was injected intravenously (i.v) into the mice via theirtail. The mice were sacrificed under ether anesthesia
48 hours after i.v injection. The maternal blood, placentas and fetuses were excised and the amniotic fluids
were collected; all were weighed immediately and freeze
dried. The radioactivity of each dried sample was determined by ')'-ray spectrometry using high-purity Ge
detectors. The uptake behavior was evaluated in termsof uptake percentage of the injected multitracer (%).
The thirteen radioactive isotopes mentioned above
were observed and evaluated in the maternal blood,placentas, fetuses and amniot ic fluids in the last stageof pregnancy (I8-day-pregnant dams and fetuses), as
shown in Table 1. From results in Table 1, we canunderstand the transport, retention and excretion ofthese isotopes across the barrier system of the maternal blood- placentas- fetuses. Trace elements suchas Be, Sc, Zr, and Ru were mainly transferred, accumulated and retained in the placentas. In particular,
the Sc uptake percentage in the placentas was about
290 times that in the maternal blood and Sc hardly
passed through the placental membrane into the fetuses. On the other hand, the other nine trace elements (Y, Mn, Co, Fe, Zn, Se, Rb, Sr and Rh) weretransferred through the placenta and mostly accumulated in the fetuses. The uptake percentage of Sr was
about 130 times higher in the fetuses than in the maternal blood, and about 97 times higher in the fetuses
than in the placentas. Namely, a large amount of Sr
was transported and concentrated in fetuses. It cantherefore be presumed that the accumulation of Sr is
involved in active bone formation in fetuses and that Sr
Faculty of Medicine, Kanazawa University

114

Table 1. Uptake percentages of 13 trace elements (Be, Sc,
V, Mn, Co, Fe, Zn, Se, Rb, Sr, Zr, Rh , and Ru) in thematernal blood, placentas, fetuses and amniotic fluids
48 hours after i.v injection. (unit: %)Maternal Blood"

Piacente"

Fetus"

0.38
0.18

0.93±0.15
52.85±4.38

0.75±0.11

0.01

N.D.

"Mn

0.29
0.88

3.00±0.26
1.51±0.37

9.27±0.75
8.13±0.88

0.05
0.24

el Co

0.09

0.35±0.07

2.45±0.03

7

Be

41SC

41V

Amniotic Fluir

0.20
0.10

e'Fe

15.57

12.12±4.91

48.78±2.82

0.07

16

Zn

0.18

Se

2.50±O.28
2.59±0.31

36.74±2.12

76

0.98
1.51

I3Rb

2.89

2.11±0.1 8

14.57±0.27
14.08±0.51

0.31
0.18

·'Sr

0.07
0.33

0.09±0.01
3.54±0.88

8.55±0.52
1.07±0.11

0.08

2.03
0.42

1.78±0.22
0.85±0.23

12.97±0.28
0.59±0.60

0.13
0.12

" Zr
leRh
I03

Ru

0.05

The total blood volume calculated by multiplication of body weight by 0.07.
Each pregnant mouse had 13 placentas and fetuses on average.
The total volume of amniotic fluids used was
1.659 g as reported in the literature. 3 )N. D. indicates "not detected"; in this case, its detection limit was estimated to be 0.03%.

is one of the bone-accumulating elements. Table 1 also
shows that Y, Mn, Zn, and Se, which are considered
to be essential trace elements in fetuses, have similartypes of uptake behavior in the maternal blood, placentas, fetuses and amniotic fluids. On the other handthe uptake percentages of Fe and Rb in the maternal
blood were equal to or slightly higher than those in
the placenta. This can be explained by the fact that
Fe and Rb (analogous to K) are transported into theplacenta and easily pass across the maternal blood,placenta tissue and fetus.
In our laboratory, the examination of the distribution of some trace elements in the organ and t issue infetuses immediately before birth and in pups immediately after birth is in progress. In the future , we hope
to discuss on the involvement of some important elements in the final crucial stage of pregnancy and in theearly stage of development.
References
1) S. Enomoto et al.: RIKEN Accel. Prog. Rep. 33 , 111(2000); 34, 126 (2001); 34, 127 (2001).
2) Ambe group had developed the multitracer method in
RIKEN and reported it in: Chern. Lett. 1991 , 149;
Anal. Sci. 7 , Suppl. , 317 (1991); J. Radioanal. Nucl.
Chern. 195, 297 (1991).
3) Y. Tajima et al.: in Biological Reference Data Book on
Experiment Animals (in Japanese) (Soft Science, Tokyo,1989), p. 247.

RIKEN Accel. Prog. Rep. 35 (2002)

Influence of sodium iron ethylenediaminetetraacetic acid and ferrous
sulfate on the transport of trace elements in everted intestinal
segments of rats
K. Igarashi,* Y. Nakanishi,* R. Hirunuma, S. Enomoto, and S. Kimura*
Iron deficiency in developing countries is largely
due to the poor absorption of iron from thier foodstuffs. The staple foods, such as grains, vegetables
and legumes, contain non-heme iron, which has a low
intestinal absorption efficiency compared with heme
iron. Heme iron from meat and meat products is absorbed as an intact porphyrin structure by specific receptors in the brush border mucosa. On the other
hand, non-heme iron must be solubilized to be absorbed from intestine. Furthermore, the staple foods
also contain inhibitors of iron absorption such as phyticacid and polyphenols. The bioavailability of non-heme
iron is extremely low because these inhibitors bind ironin the intestinal lumen. The absorption rate of vegetable iron is only about 1- 2%.1) Iron is taken up fromthe lumen and retained in the mucosa, and a fraction istransferred out of the mucosa into the organism. Irontransport occurs primarily in the duodenum, jejunum
and ileum, which adapt iron absorption capacity in response to changes in body iron stores. Distal partsof intestine show no regulation and are markedly lessefficient in the transport of iron.
Since iron deficiency is attributed to poor absorptionof dietary iron, food fortification is assumed to be aneffective method for enhancing iron absorption. Foodfortification has also been recommended as a long-term
approach for improving iron deficiency. Therefore, iron
fortification programs have been implemented to prevent iron deficiency in many developing countries. 2- 6)
Sodium iron ethylenediaminetetraacetic acid
(NaFeEDTA), a metal chelate, is one of the fortificants
used in food fortification programs. It is a flavorless,inert compound. It is reported that the bioavailabilityof NaFeEDTA is nigligibly influenced by inhibitors ofiron absorption, indicating that NaFeEDTA is a suitable food additive for iron fortification. On the other
hand, it is possible that EDTA may bind to metals
other than iron and influence their absorption becauseof its strong chelating property. In a previous study, it
was shown that NaFeEDTA may possibly inhibit theincorporation of Zn and Co into rat organs becauseof its chelating property, although the results suggestthat N aFeEDTA is not affected by tannic acid in theabsorption of various elements.
Thus, to investigate the effects of NaFeEDTA andferrous sulfate (FeS04) on the transport of various
trace elements, we determined the uptake rates of trace
Graduate School of Human Life Sciences, Showa Women's
University

Table 1. Composition of Tyrode solution.

NaCl
KCl
NaH 2 P0 4
D-glucose
NaHC0 3
CaCb·2H 2 O
MgCb·6H 2 O

mmol/l137.00
2.70
12.00
15.00
0.40
0.14
0.05

elements in everted intestinal segments of rats, using
a multitracer technique. We further determined theeffect of tannic acid on the incorporation of trace elements.
Seven-week-old male Wistar rats were purchasedfrom Charles River Japan, Inc. and were housed instainless steel cages. The cages were placed in an airconditioned room with 12 h of light. They had freeaccess to diet and drinking water.
The rats were subjected to overnight fasting andthen their abdomens were opened under anesthesia. A
6-cm-Iong segment of each of the duodenum, jejunum
and ileum was removed and everted. The segments
were filled with 0.6 ml of buffer shown in Table 1 (pH7.2), and then incubated with 10 ml of buffer containing NaFeEDTA or FeS04 and Ag-derived multitracer
solution for 1 h. The perfusion was kept equilibrated
with 95% O 2 and 5% CO 2 at 37°C. After incubation,
the serosal solution were collected. These samples wereplaced in a Ge detector, and the radioactivities of themultitracers were measured.
The data on the biodistribution of samples are currently being analyzed. The experimental results obtained will indicate the mechanism of metal transport in the intestine and the effects of N aFeEDTA and
FeS04 on intestinal uptake.
References
1) L. Hallberg: Ann. Rev. Nutr. 1, 123 (1981).
2) M. Olivarez , F. Pizarro, and O. Pineda: J. Nutr. 127,
1407 (1997).
3) R. F. Florentino and M. R. A. Pedro: Food Nutr. Bull.
19, 149 (1998).
4) V. Chavasit and K. Tontisirin: Food Nutr. Bull. 19, 164(1998).
5) C. lost, J. J. Name, R. B. Jeppsen, and H. D. Ashmead:J. Am. Coll. Nutr. 17, 187 (1998).
6) M. Layrisse, J. F. Chaves, and H. Mendez-Castellano:
Am. J. Clin. Nutr. 64, 903 (1996).

115

RIKEN Accel. Prog. Rep. 35 (2002)

Metabolic studies on multitracer-injected rats and plants using a
prototype multitracer gamma-ray emission imaging system(MT-GREI): A proposal
R. Hirunuma, S. Motomura,*l Y. Gono,*l R. Amano,*2 and S. Enomoto
It was proposed in multitracer research that the uptake distribution of various elements in rats and plants
be examined using a new 'Y -ray detection system, multit racer l'-ray emission imaging (MT-GREI). A multitracer technique has been developed using the RIKEN
Ring Cyclotron. The technique has been applied forthe investigation of the behavior of various radioactive trace elements in chemistry, biology, pharmacology, medical sciences, and environmental science. The
technique has the advantage that the behavior of various elements can be determined under strictly identical conditions. However, with the present technology, a sample has to be separated into parts and tobe measured them individually. And the behavior oftracer isotopes must be confirmed. MT-GREI is proposed to identify the positions of all isotopes simultaneously. This system uses two segmented Ge detectors.
A high-energy-resolution Compton camera consistingof two segmented Ge detectors was used to measure
the positions of many isotopes in a sample simultaneously. Segmented Ge detectors were developed tofabricate Ge telescopes combined with large-sized Ge
detectors. I) Their dimensions are 50 x 50 x 20 mm 3 ,and their cathodes are divided into 25 segments oflOx 10 mm 2 area. The segmented Ge detector was
combined with a large-sized Ge detector. They wereused as a telescope and successfully corrected Doppler
shifts of energies of l'-rays emitted from rapidly recoiling reaction products. Two segmented Ge detectors
can be used for identifying the l'-ray source position
when they are used as a telescope (a Compton camera). Monte-Carlo simulation was performed to optimize the conditions for the design of this system. 2,3)
The multitracer is prepared from Ti, Ag, and Au
foils irradiated with 12C, 14N, and 16 0 beams accelerated by the RIKEN Ring Cyclotron. The first ex-

*1
*2

116

Department of Physics, Faculty of Science, Kyushu University
School of Health Sciences, Faculty of Medicine, Kanazawa
University

periment is to examine the uptake distribution of various elements in the organs of rats using a multitracer.
The multitracer solution is administered to the rats.
One to three days after administration of the multitracer, the rats are sacrificed under deep diethyl ether
anesthesia, frozen immediately, fixed with ice-cold 8%
carboxymethyl cellulose, frozen on the specimen stageat -20°C , and sliced to 100/Lm thickness at -20°C
with a microtome. The distribution of radioactivity ineach area of the selected slices is determined by l'-raymeasurement using MT-G REI.
The second experiment is to examine the uptake behavior of the multitracer in various plants (for example, komatsuna, tomato, and rice). The roots of theplants are kept for several weeks in the multitracer solution . After this uptake period, the roots are washed.
The roots, leaves, stems , flowers, and seeds are driedat 30°C, and each dried sample is determined using
MT-GREI.
The distribution of radioactivity of various nuclides
in each area of the selected slice samples of rats andplants was possible to detect using MT-GREI. It isbelieved that in medical institutions MT-GREI can beused as a substitute for autoradiography.
This system enables the measurement of a sample
without separating it, which is a great advantage whenused for living things. This system is primarily designed for multitracer applications. Imaging multiple
nuclides simultaneously becomes possible, and its application in nuclear medicine and clinical diagnosis is
expected.
References
1) Y. Gono et al.: Nuel. Phys. A 588 , 241e (1995).
2) Y. F. Yang et al.: IEEE Trans. Nuel. Sci. 48 , 656 (2001).
3) S. Motomura et al.: RIKEN Rev. , No. 35, 116 (2001).

RIKEN Accel. Prog. Rep. 35 (2002)

Alleviation of Cadmium cytotoxicity by manganese (II)T. Yanagiya, N. Imura,* S. Enomoto, and S. Himeno*
Cadmium (Cd) is a highly toxic metal that causes
adverse effects in organisms, however, little is known
as to how Cd enters cells. Metallothionein (MT) plays
an important role in Cd detoxification. Recently, weestablished a Cd-resistant cell line (Cd-rB5) from immortalized MT-null mouse fibroblasts, and found that
Cd-rB5 cells exhibited a marked decrease in Mn andCd uptake. 1 ,2 ) Kinetic analyses revealed that Cd traverses cells partly via a high-affinity Mn transport system, and that the suppression of this pathway is oneof the determinants of the reduced susceptibility to Cd
in Cd-rB5 cells. 2 ) To clarify the role of the transportsystem for Mn in the cytotoxicity of Cd, we examined
the modulation of cytotoxicity and accumulation of Cd
by Mn, using Cd-rB5 and their parental cells.
As shown in Table 1, the simultaneous addition of
MnCl 2 to a medium alleviated the cytotoxicity of Cd
in parental cells dose dependently. In addition, theaccumulation of Cd in parental cells was reduced by
the addition of MnCI 2 . In Cd-rB5 cells, however, Mn
did not modulate either the cytotoxicity or the accumulation of Cd. These results suggest that Mn may
compete with Cd in entering cells, leading to a reduction of Cd cytotoxicity.
We further examined the effect of other divalent metals such as Zn, Co, Ni, Fe and Cu, on Cd-induced cytotoxicity and Cd accumulation. The cytotoxicity andaccumulation of Cd in parental cells was attenuated by
the addition of ZnCI 2 , but not by CoCb, NiCb, FeS04
or CuCI 2 , suggesting that Zn may also have an affinity
to the transport system for Mn and Cd.
In this study, we demonstrated that the simultaneous addition of Mn reduced both the cytotoxicity andaccumulation of Cd in parental cells, but not in CdrB5 cells in which the high-affinity transport system
for Mn does not function. These results also suggestthat the transport system for Mn may be used for the
uptake of Cd. Moreover, we also demonstrated that
Zn reduced the cytotoxicity and accumulation of Cd
only in parental cells. Although Zn is known to bean efficient inducer of MT, a primary factor for Cd
detoxification, the reduction of Cd cytotoxicity by Zn
in parental cells is due not to the induction of MT,
but to the inhibition of Cd accumulation. Our findings obtained from MT-null cells suggested a new roleof Zn as a blocker of cellular Cd accumulation via thehigh-affinity Mn transport system.

Table 1. Effect of simultaneous addition of MnCb, ZnCb,
CoCb , NiCb, FeS04 or CuCb on Cd-induced cytotoxicity and Cd accumulation in Cd-rB5 and parental cells.
Parental cells
Metals added tothe medium ()1M)

Cd-rB5 cells

IC50 of Cd (flM) ,100Cd uptake(% of control) b

IC,o of Cd (flM)'

MnCI,

I09Cd uptake(% of control) •2.21

100.0 .± 3. 1

22.46

3.86

43.9± 1.4·

21.33

97.0 ± 3 .0

7.13

17.3 ± 1.4·

2l.51

95 .8 ± 4 .7

10

21.32

9.9±0.2 •20.10

95 .6 ± 2.7

20

22.17

9.0 ± 0.8 •

16.00

101.2 ±7.9

ZnCl,

100.0 ± 2.0

2.21

100.0 ± 1.2

22.46

100.0 ± 1.3

2.31

97 .1 ± 1.3

22 .36101.2±3.1

2.33

86.1 ± 3.4·

21.77

97.2 ± 9.4

10

5.64

50.0 ± 4.8·

21.96

97.6 ± 5.6

20

8.03

38.3 ± 1.8·

21.36

107.5 ± 4.1

2.21

100.0 ± 7.6

22.46

100.0± 3.9
102.0 ± 4.8

CoCl,

2.45

104.4 ± 2.1

22.52

2.51

103 .1 ±3 .3

21.09

98.7± 1.3

10

2.42

101.6 ± 6 .2

22 .6699.1 ± 2.8

20

2A6

92.5 ± 3.6

22 .9799.9±8.6

2.21

100.0 ± 6.5

22.46

100.0± 0.2

2.40

97.4 ± 2.8

23 .27100.5 ± 1.5

2.43

102.7 ± 2.9

22.91

98 .6±2,42.32

96.6 ± 3.4

21.71

100.4 ± 4.0

NiCI,

10
20
FeSO,

2.38

100. 1 ± 1.4

22 .16100.6± 3.6

2.21

100.0 ± 3.2

22.46

100.0± 3.1

2.39

101.7±6.922.45103. 1 ± 5.5

2.57

104.9 ± 2.6

22.27

100.9 ±4.6

10

2.59

101.2 ±3 .2

22 .68104.0 ± 5.0

20

2.56

92 .8 ± 2.2

22 .09103.5 ±4.3

2.21100.0 ± 2.5

22.46

100.0 ± 3.0

CuCI,

2.51

98 .3 ± 2.0

21.96

100.8 ± 3.2

2.45

98.5 ± 1.4

21.11

98.3 ± 1.7

10

2.55

90.0±2.5 •22.44

98.0± 2.5

20

2.19

84.5 ± 1.7·

22.30

98.2 ± 2.4

a Cells were exposed to CdCI, in the absence or presence of I. 3. 10 and 20 flM MnCI,. ZnCl,. CoCI,. NiCI,.
FeSO. or CuCl, for 48 h, and then the surviving cells were determined by MIT assay. The concentration of
metals required to kill 50% of the cells as calculated by MTf assay.
b Cells were exposed to 2)1M [,09Cd)-CdCI, in the absence or presence of I, 3, 10 and 20)1M MnCI,. ZnCl,.
CoCl" NiCl" FeSO. or CuCI, for 48 h. Asterisks indicate significant difTerences from the value obtained in theabsence of metal inhibitors by f lest (°P<0.01).

Utilization of MT-null cell lines enabled us to clarify
the significant role of metal transport systems as modulators of Cd cytotoxicity. Further studies are required
for the identification of Cd and Mn transporters.
References
1) T. Yanagiya et al.: Life Sci. 65, PL177 (1999).
2) T. Yanagiya et al.: J. Pharmacol. Exp. Therap. 292,
1080 (2000).

School of Pharmaceutical Sciences, Kitasato University

117

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of the binding affinity of multitracer to an
apoplast protein extracted from soybean root t
J. Furukawa,* R. Hirunuma, S. Enomoto, and T. M. Nakanishi*
More than 200 proteins were localized in plant
apoplasts and the mobility of some of these proteins
was thought to be affected by AI. It was also suggested that the inhibition of the protein mobility wasa result of the linkage of proteins and other cell wallcomponents mediated by AI. In this study, we compared the binding affinity of various metal elements toan apoplast protein in the presence and absence of Al
by means of the multitracer technique.
Root tips of two-day-old seedlings [Glycine max. (L.)
Merr. cv. Tsurunoko] were excised between 2 and 6 mmfrom the root tip, corresponding to the elongation
zone. An apoplast protein was extracted from theseexcised roots with 50 mM MgCl2 solution by meansof the infiltration method. After the extraction, protein was ultrafiltrated through a molecular membrane(10000 M.W., 8000 x g).
Multitracer solution was prepared from a silver foil
irradiated by the RIKEN ring cyclotron. From the
gamma ray spectroscopy analysis, 11 nuclides eBe,
22Na, 46S c , 52Mn, 59Fe, 56CO, 65Zn, 75Se, 84 Rb , 85Sr
and 87y) were simultaneously determined.
One p,g of the apoplast protein was mixed with
200 p,l of 50 mM MES buffer solution (pH 5.0 and 6.0)
containing the multitracer and was incubated for 30
min at 4°C and then ultrafiltrated through a molecular membrane (10000 M.W., 4500 x g). The membrane
was washed with the 200 p,l buffer solution after ultrafiltration. To determine the effect of Al on the binding
affinity of elements to the apoplast protein, buffer solutions containing AICl 3 (100 p,M or 1 mM) and themultitracer were also prepared.
Table 1 shows the binding affinity of trivalent elements. The trivalent elements, Sc, Fe and Y, showed
high binding affinity at both pH 5.0 and pH 6.0. The
high binding affinity of trivalent elements and the lowbinding affinity of monovalent and divalent elements tothe protein (data not shown) suggested that the binding affinity of elements to the protein increased in thefollowing order: monovalent < divalent « trivalent.
At pH 5.0, the amounts of both Fe and Y binding to
the protein decreased in the presence of 100 p,M AI.
When 1 mM of Al was added, the binding affinities
of Fe and Y further decreased. The decrease in thebinding affinity suggested that there was a competition between Al and either Fe or Y for binding to theapoplast protein.
We also carried out the measurement of binding
affinity using the protein that was extracted from AItreated roots (200 p,M AICI 3 , 2 h). After Al treatment,
some proteins were not extracted. Compared with thebinding affinity to the protein, the effect of Al on thebinding affinity of these two elements was observed.
The binding affinity of Fe decreased to 69.3% by theapplication of 1 mM AI. This value of binding affinity corresponded to 83.4% of that without Al treatment, whereas in the case of using protein extracted
from non-AI-treated roots, the binding affinity of Fe
decreased to 47.9%. A similar tendency was observedin Y. These results suggest that the proteins not extracted after Al treatment had a binding affinity competing between Al and either Fe or Y.

Table 1. Binding affinity of detected elements (% of incubated). The protein column, a nd Al and protein
column indicate the cases with the buffer solution containing 1 p,g of protein and 1 p,g of protein plus
AI , respectively. The numbers in brackets are the percentage of the binding affinity based on that ofthe protein column.
pH 5.0pH 6.0Protein extracted afterProtein extracted without
Protein extracted without
Al treatment
A1 treatment
Al treatment
100 11M
100 11M
100 11M
ImMAI
ImMAI
lmMAl
Element Protein
AI&
Al&
Protein
A1&
Protein& Protein& Protein& Protein
ProteinProteinProtein76.9±1.8 93.2±0.2 84.5±5.8
76.6±2.8 74.5±6.6 51.0±3.0
81.0±0.1 85.0±8.6 65.1±4.2
Sc 3+(121.1) (109.8)(100.0)(100.0)(97.3)(66.6)(100.0)(104.8)(80.3)
36.7±2.4 20.6±3.2 15.9±3.5
66.9±3.6 70.4±15.4 32.0±2.0
83.1±6.6 86.9±5.2 69.3±2.5
Fe 3+(100.0)(56.1)(43 .3)(100.0)(105.2)(47.9)(100.0)(104.5)(83.4)
93.3±2.9 74.5±7.3 17.8±5.5
94 .6±6.4 84 .6±2.0 40.8±8.4
79.4±2.9 65.2±9.5 5.9±O.7
y3+(79.8){IOO.O}{82.1}{IOO.O}{43 .1}{100.0}{7.4}{89.4}{19.l}
Values are means (%) ± S.D. for at least 3 experiments.
Condensed from the article in Anal. Sci. in press
Graduate School of Agricultural and Life Sciences, University of Tokyo

118

RIKEN Accel. Prog. Rep. 35 (2002)

Influence of samarium on the uptake of trace elements by marigold
H. Suzuki,*l H. Kumagai,*l F. Mori,*2 K. Sakamoto,*2 K. Inubushi,*2 and S. Enomoto
With the continual development of high-technology
industries , rare-earth elements (REEs) are being usedan ever widening range of materials including fluorescent substances, magnets and superconductors. With
such uses , however , REEs may cause the environmental pollution. The emission of REEs into the environment would pollute soils, which in turn would affectplants. However , the influence of REEs on plants remains almost unknown , except for La, Ce, and Yb. 1 - 3 )In the previous paper,4) we revealed that La not only
inhibits plant growth but also affects the uptake oftrace elements such as Mn, Se, Rb, and Sc. Such effects of La may be due to the impairment of the permeability of the plasma membrane. Information on theinfluence of REEs on plant growth and the uptake oftrace elements should be useful in revegetation or phytoremediation. Consequently, we studied the influenceof Sm, which is used as a magnetic material in hightechnology industries, on plant growth and the uptakeof trace elements, and report our results.
Seeds of marigold plants (Tagetes patula L. cv.
Bonanza spray) were sowed in 9-cm pots (240 mL in
vol ume) containing 400 g of river sand with 10 J.imol Sm
kg- 1 sand (Sm treatment) or without Sm(N0 3h. As
the elongation of the root from the marigold seed wasseriously affected at Sm concentrations higher than
50 J.imol Sm kg- 1 sand, the experiments were carriedout with a Sm concentration of 10 J.imol kg- 1 sand.
Plants were grown in a biotron with a 18/6 h day/night
regime, at 15,000 lux, 65% relative humidity and 25°C.
The marigold seedlings were thinned to 1 plant per pot
seven days after sowing. Throughout the experiment,
the pots were weighed twice a day and watered to 55%
of the water-holding capacity of river sand. The detailsof plant nutrient management have been described in
our previous paper. 5)
A multitracer solution was prepared from an Ag target that was irradiated with a 135 Me V /nucleon 14N

beam accelerated by the RIKEN Ring Cyclotron. The
Ag target was dissolved in HN0 3 and then the Ag was
precipitated with HCI as AgCI, leaving a multitracer
in solution. The solution was evaporated to dryness,and dissolved in a fertilizer solution. The multitracer
containing the radionuclides of 7Be, 22Na, 46S c , 51Cr,
54Mn, 59Fe, 56Co, 65 Zn , 75Se, 83Rb, 85S r , 88y, 88Z r ,and 95mTc was applied 29 days after sowing. The
chemical forms of the radionuclides on administration
were assumed to be Be 2+, Na+, Sc3+ , Cr 3+, Mn2+,
Fe 3+, Co 2 + , Zn 2 + , Se032-, Rb+ , Sr 2+, y3+ , Zr4+ ,and Tc04 - .6) The plants were sampled for analysis 21
days after the multitracer was added. The radioactivities of the plants were measured using Ge semiconductor detectors. The radioactivity applied to the pot was
taken as 100% and by comparison, the radioactivity ofthe plant was expressed as a percentage of the uptake(relative uptake, % of DOSE).
Table 1 shows the relative uptake of radionuclides
and the fresh weight of plants. The fresh weight of theaerial parts and roots of marigold decreased with Sm
application. Compared to the results for La reported
in the previous paper,4) the decrease in the growthof aerial parts was similar , but the decrease of theroot growth was not. Consequently, Sm may have astronger effect in inhibiting plant growth than La.
For the uptake of trace elements, Sm treatment resulted in lower uptake of 22Na, 54Mn, 56CO, 75Se, and
83Rb than in the control. On the other hand, Sm treatment resulted in higher uptake of 51Cr and 88Zr thanin the control. At the same time, the uptake of 7Be,
46Sc, 59Fe, 65 Zn, 85Sr, 88y, and 95mTc showed little orno difference between Sm treatment and control. In
comparison with La in the previous paper,4) Sm wasdifferent in that 22Na and 56Co uptake decreased, 51Cr
and 88 Zr uptake increased, and 46Sc uptake was not affected. While REEs are considered to have characteristics similar to each other, the present results suggest

Table 1. Fresh weight of plants and relative uptake of various radionuclides by plants. a)
Relative uptake

Fresh weight

Treatment(g plant· 1 )Control
Sm treatment

Root

7
Be

22Na

46

6.42
5 .15

3 .29
2 .78

0.1
0 .1

17.1
11 .9

1.6
1.6

Stude nt's t -testC)a) Each value is presented

n.s.

*1

SC

n.s.

5l

Cr

1.2
1.7

54

Mn

59 Fe

56CO

19.4
14 .0

1.5
1.4

9 .8
7.9

n.s.

65

Zn
9.3
9.0

n.s.

75

Se

22.4
17.6

Rb

85Sr

SSy

S8

Zr

95mTc

46.9
39 .9

6.5
5 .6

2.4
2.8

1.2
3 .5

67.2
61.7

n.s .

n.s.

83

n.s.

as the mean of data from four plants .

b) Aeria l parts: c) n.s., not significant;*2(% of DOSE)

A.p.b)* p< 0.05; ** P< 0 .01; *** P< 0.001.

Radioisotope Research Center, Chiba University
Faculty of Horticulture, Chiba University

119that each REE itself may have unique effects on the
uptake of trace elements by a plant. Further investigation is needed to elucidate which characteristics of
REEs (including fine differences in their hydrolytic pH
values) cause such differences.
References
1) E. Diatloff and F. W. Smith: J. Plant Nutr. 18, 1963
(1995).
2) S. Ishikawa, T. Wagatsuma, and T. Ikarashi: Soil Sci.

120

Plant Nutr. 42, 613 (1996).
3) E. Diatloff, C. J. Asher, and F. W. Smith: Materials
Sci. Forum 315/317, 354 (1999).
4) H. Suzuki, H. Kumagai, F. Mori, K. Sakamoto, K.
Inubushi, and S. Enomoto: RIKEN Accel. Prog. Rep.
34, 145 (2001).
5) H. Suzuki, H. Kumagai, K. Oohashi, K. Sakamoto, K.
Inubushi, S. Enomoto, and F. Ambe: Soil Sci. Plant
Nutr. 46, 283 (2000) .
6) RIKEN Rev., No. 13, (1996).

RIKEN Accel. Prog. Rep. 35 (2002)

The effect of EDTA complexation on diffusion ofvarious ions in granitic rockT. Mifune,* Y. Takahashi,* c. Egawa,* R. Hirunuma, and S. Enomoto
Diffusion of various ions through micropores of sediment and rocks has been studied in order to quantify their behavior in the diagenetic processes in sediment or their migration in groundwater-rock systems. 1 ,2) The difference in diffusion behavior among
various ions can be explained primarily by their diffusivity in water and also by the influence of surface diffusion, as evident for some ions which havestrong affinities with mineral surfaces. 2 ) However, theirdiffusion behaviors may change in the presence ofcomplexing ligands in water such as natural organics like humic substances, and other synthetic agents.
Ethylenediaminetetraacetic acid (EDTA), well-known
synthetic chelating agents forming stable complexes
with many cations, have been widely used in various industrial fields to late, which has resulted in high EDTA
concentrations in freshwater systems ranging from10- 100 ,ug/dm3 , for example, in Swiss or German
rivers. 3 ) The presence of EDTA in natural aquifers willalter the behaviors of various ions in the environment,such as their sorption and diffusion, due to the highstability of metal-EDTA complexes. In this study, weapplied a multitracer technique to deduce the EDTA
complexation effect on the diffusion behavior of various
ions migrating through granitic rocks.
The diffusion through granitic rocks was examinedby the through-diffusion method. 4 ) Weathered granite samples from drilling cores of Toki granitic rocks ,found in central Japan, were cut into 5-mm-thick and
30-mm-diameter disks. Each disk was fitted tightly
between two cells filled with water (ionic strength:0.10 mol/dm 3 by KCI). Three systems (A, B, and C)
were studied: A, pH 4 without EDTA; B, pH 4 with
1.0 mmol/dm 3 EDTA; C , pH 6 with 1.0 mmol/dm3
EDTA.
The radioactivity of each radioisotope in the diffusion cell increases with time, while that in the source
cell apparently becomes constant after its decrease during approximately the about first 10 days, mainly due
to the sorption to the rock samples. Diffusion curves
selected for some cations in systems A- C are shown in
Fig. 1, where the ratio of the concentration of each ion
in the diffusion cell at each time, CD (t) , to that in thesource cell after reaching an apparent constant value
for each ion, Cs-const, is plotted on the vertical axis.
In the absence of EDTA (system A), each ion diffuses
depending on the character of each element, regulated
mainly by the charge of the ion and the hydrated ionicradius. In the presence of EDTA (systems B and C) ,Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University

SystemC

SyslemA

10

20

30

40

Time (days)

50

0

)0

20

30

40

Time (days)

50

0

10

20

30

40

50

60

Time (days)

Fig. 1. Diffusion curves for systems A-C. System A: without EDTA, pH 4; System B: with EDTA (1.0 mmol/
dm 3 ) , pH 4; System C: with EDTA (1.0 mmol/dm 3 ),pH 6.

however , the behaviors of ions such as Mn(II), Co(II),
Y(III), and Ce(III) that form stable complexes withEDTA are similar to one another. This must be dueto the formation of the EDTA complex, where the differences among diffusion behaviors of these four ionsdisappear. In system B, the CD (t) / Cs-const ratios forMn(II), Co(II) , Y(III), and Ce(III) were quite low during our experimental period compared with those of Rb
and Na, probably due to the sorption of the EDTA
complex on oxide surfaces of the weathered granite
such as Fe- and AI- oxides. The negative charges on
the surface increase at higher pH, which inhibits thesorption of the EDTA complex. This probably allows
the diffusion of Mn(II), Co(II), Y(III), and Ce(III) as
the EDTA complex at pH 6 (system C). These results
indicate that in systems Band C, the diffusion of eachion is governed not by that ion's character but by the
behavior of EDTA. This shows that we need to identify the species dissolved in each ion in natural aquifers
in order to predict the diffusion of various ions throughrocks. However , the diffusion curves of Na+ and Rb+
for systems Band C were similar to those for system
A , since Na- and Rb- EDTA complexes do not form
under this experimental condition as calculated fromtheir stability constants. It is suggested that the diffusion behavior of Na+ and Rb+ is regulated by the
diffusivities in water in these three systems, irrespective of the presence of EDTA.
References
1) R. A. Berner: Eary Diagenesis (Princeton University
Press, Princeton, 1980).
2) K. Skagius and 1. Neretnieks: Water Resour. Res. 24,
75 (1988).
3) A. D. Satroutdinov et al.: Environ. Sci. Technol. 34,
1715 (2000).
4) T. Yamaguchi and S. Nakayama: J. Contam. Hydrol.
35 , 55 (1998).

121

RIKEN Accel. Prog. Rep. 35 (2002)

Molecular design of organic ligands highly selective
for lanthanide metal ionsS. Umetani,*1 Y. Komatsu,*2 H. Yamada,*3 and S. Enomoto
In the course of our studies on the solvent extractionof lanthanides using ,8-diketone-type acylpyrazolones
and 3-phenyl-4-benzoyl-5-isoxazolone (HPBI), we havenoticed that the acidity of the extractant and its separability are strongly related to the distance between
the two donating oxygens. This finding has been confirmed by a systematic investigation of three series of,8-diketones: the cyclic group (1) in which the 0-0
distance is governed by ring-structure geometry, theheterocyclic 4-substituted pyrazolones (2), governedby the steric effect between the 3-methyl group andbulky 4-acyl substituents,1,2) and the a-substituted ,8diketones (3), governed by the steric effect of bulky
substituents at their a -position. The structures of ,8diketones in use are shown in Fig. 1.
The introduction of a methyl group to the a position in the molecular structure of benzoyltrifluoroacetone (BFA) yielded a-methyl benzoyltrifluoroacetone (MBFA). Their 0-0 distances were estimated by the semi-empirical molecular orbital calculation, MNDO/H, to be 2.51 A and 2.42 A, respectively. 1H NMR spectrum data clearly show that the
intramolecular hydrogen bonding of MBFA is strengthened (sharp OH-peak at is = 15.8 ppm) owing to its
smaller 0-0 distance , compared to that of BFA (verybroad OH-peak at is = 15.2 ppm). Their dissociation
constants, pKa , were measured by the potentiometrictitration method in a water-dioxane solution (25: 75
v Iv) to be 8.10 for BFA and 10.35 for MBFA.
The extraction of lanthanides using BFA and MBFA
(denoted by HA) was performed into benzene. The
overall equilibrium can be written as follows:
Ln 3+ + 3HA o = LnA 3,0 + 3H+.
The validity of this equation was confirmed throughthe effects of pH and concentration of the extractant(HA) on the extraction of lanthanides. From this equation , the extraction constant Kex and the distribution
ratio D (D = [LnA 3]0/[Ln 3+]) can be deduced:
Kex = [LnA3]0 [H+] 3/[Ln 3+] [HA]3 0= D [H+ ]3 /[HA]3 0,

3Fig. 1. Modified /J-diketones.
*1 Institute for Chemical Research , Kyoto University*2 Faculty of Engineering , Kanazawa Institute of Technology*3 Advanced Materials Laboratory, National Institute for Material Science

122

Table 1. Extraction constants and pHI /2 values for lanthanides.

LA 3 +

BFA
logKex SF a )MBFA
logKex SF a )-11.70-17.61
1.80

1.38

Pr 3 +-10.32

Eu 3 +-9.00

Ho 3 +-8.34

Yb 3 +-7.80-15.811.32

1.50-1 4.310.72

0.66- 13.59

0.66

0.64-12.933.90 b )4.68 b )Extraction into benzene. [BFA]o = [MBFA]o = 0.1 M.
SF: separation factor, defined by the difference between
log Kex values of two consecutive metals. b) Separation
factor for La and Vb.
a)log Kex = log D - 3 pH - 310g[HA]0.
Table 1 shows the extraction data of BFA and
MBFA. From the data, it is clear that BFA, with
its smaller pKa and larger 0-0 distance, can extract
lanthanides more efficiently: the Kex values for BFA
are in fact 105- 106 times larger than those for MBFA.
Otherwise, as a result of the diminution of the 0-0
distance, MBFA separates lanthanides more efficiently
than BFA: the separation factor of La and Vb, foundto be 4.68 for MBFA exceeds that for BFA which is
3.90.
It should be noted that the introduction of an a substituent in the structure of ,8-diketone is often followed by a notable decrease of the % enol tautomerof the extractant, thus hindering the solvent extraction procedure. A bromo group has been introduced
to dibenzoylmethane (DBM) and BFA to obtain a BrDBM and a-BrBFA with shorter 0-0 distances.
However, due to the predomination of their keto forms ,the attempt to obtain their solvent extraction data
was failed. Our study is now being expanded further with a phenyl group as the a-substituent for enolrich ,8-diketone derivatives such as phenyl acetylacetone (PAA) and phenyl benzoylacetone (PBA).
References
1) S. Urnetani, Y. Kawase, H. Takahara, Q. T. H. Le, and
M. Matsui: J. Chern. Soc., Chern. Cornrnun. 1993 , 78.
2) Y. Kawase and S. Urnetani: Unpublished data.

RIKEN Accel. Prog. Rep. 35 (2002)

New multitracer production: Development of a gas-jet coupledmultitarget system and an automated rapid chemistry apparatus
H. Haba, *1 S. Enomoto, R. Hirunuma, Y. Nagame, *1 and A. Shinohara*2
During the last ten years, the RIKEN multitracer
has been successfully applied for investigations of the
behavior of various elements in the fields of chemistry,
biology, medicine, and geology. The multitracers were
produced from metallic targets such as Ti, Ag, and Au
irra.d iated with 135 MeV / nucleon 12C, 14N, and 160
beams using the RIKEN Ring Cyclotron. After the irradiations, the multitracers were chemically separated
from the target material. 1) Recently, a few technicaldevelopments for the preparation of the multitracer
have been reported. 2,3) Takamiya et al. 2 ) produced
multitracers using the thermal neutron fission of 235U
at the Kyoto University Reactor (KUR). They separated the fission products from the U0 2 target using
NaCl as a catcher material. Shibata et al. 3) found thatthe multitracer solution was obtained quickly and easily by amalgamating the gold target irradiated with
the RIKEN Ring Cyclotron.
We plan to develop a gas-j et coupled multitarget sys-

Chemical separation apparatus

Multitarget chamber

tnnn
ttt
o

Target0

Aerosol cluster". ..... :... .. : ... . :........................ :O

Filterextracnon column+

NaCl, KCI, C, etc, ..... i.;~~\
G

Slider~,,,,,,,-,,,--,,,-,
Ion ex~hange or~

Aerosol generator.~.~:as_ ',Gas out

Multitracer

Aerosol cluster

Fig. 1. Schematic of the gas-jet coupled multitarget systemand the automated rapid chemistry apparatus.

*1*2

tern and an automated rapid chemistry apparatus asa novel technique for the multitracer production. A
schematic of the gas-jet coupled multitarget systemand the automated rapid chemistry apparatus is shownin Fig. 1. The multitracers are produced from various
target materials irradiated with 135 MeV/nucleon 12C,
14N, and 16 0 beams from the RIKEN Ring Cyclotron.
The targets should be multiplied in order to collect
the recoiling nuclei efficiently. The recoiling products
are stopped in helium gas, attached to aerosols suchas NaCI , KCI, and C, and continuously transported
through a Teflon capillary tube to a chemistry room.
Advantages of the gas-jet coupled multitarget system
are as follows . The multitracers are separated from thetarget material without chemical separation and aretransported to a chemistry room within a few seconds.
Thus , radionuclides with short half-lives of less than 1
minute are available for experiments. In addition, targets with various chemical forms are prepared by electrodeposition or vacuum-evaporation techniques. Furthermore, the composition of the radionuclides in themultitracer is optimized by changing the target array.
The radionuclides of interest are concentrated withthe liquid chromatography apparatus based on ion exchange or solvent extraction. As shown in Fig. 1, thereaction products transported by the gas-jet system
are deposited on the collection site of the slider. Then,the multitracers are dissolved with a desired solution
and fed into the ion exchange or extraction column .
We also plan to use circulating gaseous targets such as
Ar , Kr , and Xe using the same experimental setup.
References
1) S. Ambe: RIKEN Rev., No. 13, 3 (1996).
2) K. Takamiya et al. : RIKEN Rev., No. 35, 107 (2001).
3) S. Shibata et al.: RIKEN Rev., No. 35, 115 (2001).

Advanced Science Research Center, Japan Atomic Energy
Research InstituteDepartment of Chemistry, Graduate School of Science ,Osaka University1234. Radiation Chemistry and Radiation Biology

RIKEN Accel. Prog. Rep. 35 (2002)

Ultrafast plasma luminescence of heavy-ion tracks in insulators
K. Kimura, T. Kambara, and M. Kase
We have developed techniques for luminescence measurements with a time resolution of 85 pS.l) Using thesetechniques, we observed a novel ultrafast luminescencedecay component (UFLDC) from the track core in a
number of wide-band-gap materials: NaF, LiF, NaCI,KCl, CsCl, KBr, KI, RbI , CsI, BaF 2 , MgO, and Qalumina. 2 ) The luminescence is characterized as follows. The UFLDC is a common phenomenon in wideband-gap materials except for some types of materials such as diamond and Si0 2 . The lifetimes of
UFLDC 's are less than 100 ps and their decay curves
do not have long tails. Their specific intensities increase super-linearly with increasing excitation density. Heavy-ion irradiation such as with Xe ions resulted in strong intensity whereas that with He ionsdid not produce the UFLDC. The specific intensities
showed sample dependence, but only slight temperature dependence. The time-resolved spectra (TRS) of
the UFLDC were broad bands spreading from 200 to
400 nm. These results show that the UFLDC is novel
luminescence that cannot be attributed to known excited species, and moreover suggest that it arises frommultiple interactions among dense electron-hole pairs.
Consequently, we attribute the UFLDC to electronhole plasmas. This is the first time that it has been
confirmed that the incipient ion track can emit photons as a collective behavior. Although electron-hole
plasma luminescence is known to be observed in somesemiconductors by H+ irradiation, this plasma arises
from the diffusional recombination of free excitons withmuch longer lifetimes than those of the present samples
but is not due to the incipient track.
However, for a detailed characterization of theelectron-hole plasma, many questions remain unsolved.
One of them is why the redshift from the absorption
edge is so large. The second is how the luminescencetakes place. Considering the analogy of electron-hole
plasmas in semiconductors, it may be reasonable tosuggest that the UFLDC arises from electron-hole recombination. The shift may be explained due to thedisplacements and bindings of holes in the incipient
track. In the incipient track, ejected electrons distribute densely in a space like a sheath round a corecylinder containing holes. In the core, there is theextremely strong Coulombic repulsion among a number of excess cations , and hence binding forces in the
crystal are destroyed completely and holes (halogen
atoms in case of alkali halides) can move to aggregate:
X+X- -----+ X 2 -, X+X -----+ X 2, X+X+X- -----+ X3 -, andso forth.3) These products or intermediate states become new holes along with X, and they become thecounter parts to ejected electrons when e-h plasma
is relaxed. Recombination luminescence among suchholes and electrons causes the large redshift by the
Stokes shift , as is well known for the self-trapped exciton , and the superposition of various shifts broadens
the resultant band. If this is true, the peak and structure of the TRF should be dependent on the mass ofirradiating ions and on the constituent halogen ions of
the crystal.
To ascertain this and characterize the UFLDC further, it is necessary first to measure a precise TRL.
To date, our TRLS have not been able to provide thecorrect peak maximum or the correct band structure
because of the instability of ion beams and the small
number of sampling wavelengths. In order to overcome
these problems, we intend to develop a method for
multichannel time-correlated photon counting for eachion striking, namely, a fast secondary electron detector(FASDl)) gives timing pulses of ion penetrations witha time resolution of 25 ps. Eight wavelengths of pho-

MEM

Fig. 1. System for time-correlated 8-channel photon counting for each ion striking. FASD: a fast secondary electron detector. 1)

From back

Anode pattern~C_
Unit:mm

2.304

II

I

0.20

Fig. 2. A micro channel plate-mounted PMT with 8separated anodes.

125

_ 4

0;;"-0--'--'~-'--cl!--'---'-'----'-:::'-'-~

Time (ns)Fig. 3. Wavelength-dependent decay curves in the case thata randomly triggered diode laser is used as a lightsource.

Hamamatsu Photonics. Time-correlated counting was
performed using a modified system of models SPC330
by Becker and Hickl GmbH. This system can give atleast 8-wavelength data free from beam fluctuation.
Figure 1 shows a part of the time-correlated counting. Figure 2 shows an 8-anode MCP-PMT. Figure 3
demonstrates wavelength-dependent decay curves in
the case that a randomly triggered diode laser was used
as a light source. The monochromator was a model
Spectrapro-30Oi built by Acton Research Corporation.
The figure shows that the system has sufficient resolution.
References

ton counting are correlated with a FASD timing pulse
using a time-to-amplitude converter. The 8-photon
counting was performed using a microchannel-platemounted photomultiplier with 8 anodes and an MgF 2
window (model R4110U), which was obtained from

126

1) K. Kimura, J. Kaneko , S. Sharma, W. Hong, and N.
!toh: Phys. Rev. B 60, 12626 (1999).
2) K. Kimura, S. Sharma, and A. Popov: Radiat. Meas.
34, 99 (2001).
3) K. Kimura, S. Sharma, and A. Popov: Nucl. Instrum.
Methods Phys. Res. B, to be published.

RIKEN Accel. Prog. Rep. 35 (2002)

Enhancement of 137 Cs accumulation by phytochelatine synthetase
expression in rhizofungus Fusarium oxysporum
T. Soshi and 1. Yamaguchi
Radionuclides released by nuclear power plants into
the environment pose a potential risk to human health.
Recently, significant attention has been drawn to phytoremediation as a cost-effective technology to remove
pollutants from the environment. However, the rateof radionuclide removal using conventional plants islow. To improve the removal efficiency of plants, weare studying the utilization of rhyzosphere microorganisms, which were known to affect plant growth andmetal-ion uptake. 1,2) We have shown that the nonpathogenic Fusarium spp. symbiotic to tomato can increase the uptake amount of radionuclides through infection. 3) On the other hand, it has been suggested
that metal-binding proteins or peptides can be utilized in engineering plants and microorganisms forbioremediation. 4 ) The introduction and overexpression of metal-binding peptides, such as phytochlatins(PCs), have been exploited to increase metal accumulation by plants. 5,6) We are interested in application of
the transgenic technique and the rhyzosphere system
to phytoremediation of radionuclides. In this paper,
we report that the introduction of the Schizosaccharomyces pombe phytochelatin synthase gene to rhizofungus Fusarium oxysporum is effective in increasing
radionuclide accumulation.
The
phytochelatine
synthase
(PCS)
gene,
SPAC3HllO, was cloned by a genomic polymerase
chain reaction (PCR) using PCR primers designed according to the published genomic DNA sequence data
(GenBank accession number Z68144).5 ,6) The amplified fragment was sub cloned into the expression vector, pCPXHY2, derived from pGEM4Z (Promega). In
the pCPXHY2, the constitutive Aspergillus gpd-l genepromoter was inserted at the unique EcoRI site and thehygromycin B phosphotransferase gene (hyg) upstreamof the gpd-1 promoter for selection. The resultant plasmid pPCSHY2 was used for transformation of the nonpathogenic strain of F. oxysporum. Isolated transformants and a non-transformed control strain were cultured in 50 ml of potato dextrose broth at 25°C for 2days, and then the multitracer and radioactive cesium
mixture were added to these cultures. After 3 days,
mycelia were collected and washed three times with
250 mM CaCb. Then, mycelia were harvested by filtration and dried at 50°C overnight. Radioactivity ofeach sample was measured by a hyperpure Ge detector(SEIKO EG&G).
Table 1 shows the radionuclide accumulation ability of transformants for 51Cr, 52Mn, 56CO, 65Z n , 75Se,
83Rb, 88y, and 137 Cs. The data was expressed as a

Table l. Radionuclide accumulation ability of pPCSHY2transformants.
Strain number

Tl

1'2

T4

T5

T6

T7

T8

"Co

0.92

0.24

0.77

0.61

0.87

0.87

0.95

"0

1.50

1.52

1.05

126

0.98

1.04

1.39

1J7Cs

1.48

1.35

1.35

124

0.60

1.47

1.42

" Mn

3.53

4.06

3.95

3.90

4.33

4.42

4 .62

I3Rb

0 .99

1.07

1.56

1.17

0.95

1.10

1.41

"Se

0.55

0.60

0.59

0.6\

0.61

0.68

0.66

"V

1.38

1.72

1.63

\.92

1.78

1.81

1.79

" Zn

1.81

1.66

1.03

1.03

0.98

1.09

1.08

Nuclideratio of activity relative to that of the control strain.
PCS expression reduced the accumulation of 56CO and75Se but it did not affect the accumulation of 51Cr,
83Rb and 65Zn . A moderate increase in the accumulation of 137 Cs and 88y was observed. 52Mn was accumulated about four times more than the control. 137 Cs accumulation was elevated to almost 1.5 times that of thecontrol. The tested nuclides have not been reported tohave affinity for PCs. The results suggest that PCs
have affinity for at least Cs , Y and Mn ions. Alternatively, PSC expression might activate some other pathway of Cs, Y and Mn accumulation.
137 Cs contamination has been one of a serious problem after the Chernobyl accident. 7) Generally, the rateof 137 Cs uptake by plants is very low , since Cs ions
are tightly adhere to soil materials and organic compounds, thus it is difficult to remove them. The Fusarium strain used in this study enhances the uptake ofsome radionuclides including 137 Cs by tomato throughinfection. 1) If the PSC-expressing transformant cantransfer a significant amount of Cs ions to the hostplant, the removal efficiency of Cs would be increased.
Further studies are needed to determine the effects oftransformed Fusarium on the radionuclide uptake byplants.
References
1) S. Gouthu et al.: RIKEN Accel. Prog. Rep. 31 , 146(1998) .
2) J. A. Entry: Water, Air, Soil Pollut. 88, 167 (1996).
3) T. Soshi et al.: RIKEN Accel. Prog. Rep. 34, 165(2001).
4) M. Majare and L. Bulow: Trends Biotechnol. 19-2, 67(2001).
5) S.-B. Ha et al.: Plant Cell 11, 1153 (1999).
6) O. K. Vatamaniuk et al.: Proc. Natl. Acad. Sci. USA
96 , 7110 (1999).
7) S. Dushenkov et al.: Environ. Sci. Technol. 33, 469(1999).

127

RIKEN Accel. Prog. Rep. 35 (2002)

Effective plant-mutation method using heavy-ion beams (VI)
Y. Konomi,* T. Abe , F. Sugawara,* and S. Yoshida
There is a difference in sensitivity to ion beams between the organs of plants. I) We found that tobacco
is sensitive to irradiation with ion beams during thestage of fertilization. 2 ) In this paper we report the effect of ion beams on various tissues of wild tobacco(Ni cotiana glutinosa).
Dry seeds were irradiated with ion beams (N or C at
135 MeV /u) within a dose range of 20 to 800 Gy. Imbibition seeds incubated in 1/2MS agar medium for 12
to 60 hrs before irradiation, were irradiated with C-ion
within a dose range of 10 to 50 Gy. After 28.7 to 101.7
hrs of pollination, intact embryos in flowers were irradiated with N-ion within a dose range of 10 and 20 Gy.
One month after the irradiation, MI seeds were harvested. The MI seeds were germinated in the 1/2MS
medium at 25°C under continuous light. After one
month , we determined their germination percentage
and survival rate (number of survival plants/numberof seeds). Morphological abnormalities were observed
two months after seeding.
The germination was not affected by ion-beam irradiation in the case of dry seeds. However , the germinated plants produced no leaves and died with doses
higher than 600 Gy. The morphologically abnormal
plants appeared with a dose of 400 Gy. The abnormality rates induced by the N- and C-ion exposures were
11.6 and 8.2% , respectively. A decrease in survival
rate was observed at 50 Gy in the case of the imbibition seeds. For example, no plants survived among
the irradiated seeds which were incubated over 48 hrs.
In a dose range of 20 Gy, seeds with 51 hrs of incubation was the most sensitive stage to irradiation, whichshowed the lowest survival rate (34%) and the highest
frequencies of abnormal plants (7.2%, Table 1). On thecontrary, embryos showed the high frequencies of abnormal plants. The embryo stages were 28.7, 65.7 and101. 7 hrs after pollination within 10 Gy and their fre-Faculty of Science Technology, Tokyo University of Science

128

Table 1. Frequency of morphologically abnormal plants(MAP) induced with C-ion irradiation at various imbibition stages.
Imbibition [hrs]
14
26
48
51
59

Survival [%]95.6 ± 0.9
96.9 ± 2.7
92.0 ± 2.3
33.7 ± 15.1
96.3 ± 1.3

Frequency of MAP [%]0.0 ± 1.5
0.0 ± 5.7
3.5 ± 0.0
7.2 ± 0.0
3.1 ± 0.0

•

•

•

•

•
o

o
o

o~~~----~--~

25

50

75

100

Treatment stage [hrs]Fig. 1. Effects of embryo treatment with N- ion beams
within a dose range of 10 Gy at different developmental
stages on frequency of morphologically abnormal plants(0) and germination percentage (_).

quencies of abnormal plants were approximately 30%(Fig. 1) . The sensitivity of these organs decreased in
the following order: embryos during fertilization cycle,
imbibition seeds, dry seeds.
References
1) T. Abe et al.: RIKEN Accel. Prog. Rep. 33 , 140 (2000).
2) T. Abe et al.: RIKEN Accel. Prog. Rep. 30 , 127 (1997).

RIKEN Accel. Prog. Rep. 35 (2002)

Isolation of sterile mutants of Verbena hybridausing heavy-ion beam irradiation
K. Suzuki,*l Y. Yomo,*2 T. Abe, Y. Katsumoto,*l K. Miyazaki,*2 S. Yoshida, and T . Kusumi*2
Long blooming period and a large number of flowers
are the important characteristics of floricultural crops.
Plants belonging to the genus Verbena (Verbenaceae)
are one of the most commercially used major bedding
plants. Suntory Ltd. (Osaka, Japan) has developed
a new cultivar of the verbena 'Temari' series (Verbena hybrida) , which has many characteristics superior to those of common verbena cultivars. Because
most Temari cultivars continuously bloom with a large
number of flower clusters from spring until autumn
in temperate areas, 'Coral Pink' of the Temari series
sometimes shows a decrease in the number of flower
clusters compared to other varieties. Coral Pink of theTemari series was also observed to produce self-seeds
autonomously at a high frequency. We hypothesizedthat the number of flower clusters would be increasedby the repression of autonomous self-seed setting, andisolated sterile mutants of Coral Pink of the Temari
series using heavy-ion beam irradiation.
We have successfully isolated the flower color mutant
of Petunia altiplana by irradiation of fertilized egg cells
under in vivo conditions. I) In this report, because we
expect that the characteristics of the host plant and its
mutant are identical except for sterility, in vitro plantmaterials maintained on MS solid medium were used
for all irradiation experiments. The results of preliminary irradiation of several organs from several in vitro
plant materials including Verbena suggested that irradiation of a nodal culture with an 14N heavy-ion beam
at a dose of less than 10 Gy is effective in mutational
breeding of sterile plants without undesirable mutations such as dwarfing, leaf curling and slow growth.
Sixty-four single nodes containing two lateral mer isterns at each base of two opposite leaves of Coral Pinkof the Temari series were cultured in one plastic dishand irradiated with 0, 1, 2, 5 and 10 Gy of the 14N
heavy-ion beam at 135 MeV lu. All shoots that developed from the lateral meristems after irradiation wereplanted in soil and grown in a greenhouse. About 80%
shoot formation was observed for all doses of irradiations, and most of the shoots showed normal morphology. The sterile-mutant phenotype of each flower inclusters after open pollination was easily detected, as
shown by an unenlarged ovary. Clusters with different frequencies of sterile flowers were observed. Somebranches of clusters whose flowers are all sterile wereselected, and were propagated several times by cutting. These plants were grown to flowering and thenext selection was carried out by the same methods.
*1*2Institute for Fundamental Research , Suntory Ltd.
Flower Division, Suntory Ltd.

Repeats of this selection system could concentrate thesterile phenotype , removing the fertile one from probable chimerical plants that developed from the irradiated meristems harboring mass proliferative cells. Finally, four mutant lines with stable sterility were successfully selected (Table 1) .
In order to determine the effect of seed setting on
flowering characteristics, field trials of both the hostplant and its sterile mutants were carried out fromspring until autumn. The sterile mutants continuously
grew well compared to the host plant, and in particular, at the end of the blooming season, autumn,
the host plant started senescence probably due to acontinuous reproductive state of seed setting. It wasobserved three times in the three-month pot experiment that the sterile mutants had a larger number offlower clusters than the host plant. In the field trials, it was observed that the sterile mutants of Coral
Pink of the Temari series produced a small numberof seeds, which has not been observed completely under the greenhouse condition due to lack of pollinators.
This seed setting at low frequency and the observationof almost no effect on growth are similar to those foundin other Temari series, indicating self-incompatibility;
thus, it is assumed that the pollination with genetically heterogeneous combinations between the pollen
and the pistil as a male and female, respectively, canonly produce seeds. A cross-pollination test indicatedthat the sterile mutants of Coral Pink of the Temari
series also exhibit self-incompatibility. It is noted thatthe characteristics of the host plant and its mutants
are identical except for sterility. Finally, we conclude
that heavy-ion beam irradiation is an excellent tool
for mutational breeding of sterile mutants at a highfrequency. Moreover the mutation which causes fertile
plants to produce sterile mutants leads to an increasein the number of flower clusters and good growth.
Table 1. Summary data for isolation of sterile mutants ofCoral Pink of the Temari series.
Dose of
irradiation

No. ofmaterials

OCy
ICy
2Cy
5Cy
10Cy

15
64
64
64
64

No. ofmeristems
cultured
30
128
128
128
128

No. ofshootsdeveloped
25
ll5
88
ll5
108

No. ofsterileplants00013References
1) K. Suzuki et al.: RIKEN Accel. Prog. Rep. 32 , 146(1999) .

129

RIKEN Accel. Prog. Rep. 35 (2002)

Isolation of variegated mutants of Petunia hybrida using heavy-ion
beam irradiation
K. Miyazaki,*l K. Suzuki,*2 T. Abe, Y. Katsumoto,*2 S. Yoshida, and T. Kusumi*2
Variegation with various patterns in yellow, whiteor red, at a particular part of the leaf, regularly or
irregularly, is a special and historical characteristic ofmany ornamental plants in horticulture. Petunia is
one of the most important bedding plants in the world.
Fifteen varieties of Surfinia (Petunia hybrida) , propagated by vegetative cuttings , were developed and commercialized by Suntory Ltd. and Keisei Rose NurseryLtd. Due to substantial propagation by vegetative cuttings, variegated plants were found by chance, though
the frequency was quite low. We investigated how
we could efficiently isolate those variegated plants ofSurfinia, using heavy-ion beam irradiation to induce
an artificial mutation.
In the first step , we irradiated in vitro nodal
cuttings, containing lateral meristems cultured in
MS medium, of 10 varieties of Surfinia with 14N(135 MeV lu) at a dose of 5, 10, and 20 Gy, or 20Ne
(135 MeV lu) at a dose of 1, 5, and 10 Gy. We selected variegated mutants among in vitro shoots developed from irradiated lateral meristems. Other normal
shoots were acclimated and grown, and were screened
under greenhouse conditions. From the several variegated mutants isolated, some showed chimerical phenotypes containing both variegated and normal leaves
in one plant, however they lost the variegations due tothe dominance of normal leaves which were vigorous.
We isolated independently two mutants by in vitro selection , and two mutants by greenhouse selection.
In order to rescue such chimerical mutants, we developed on alternative modified selection method using
an in vitro regeneration technique. We again irradiated in vitro nodal cuttings of 12 varieties of Surfiniawith 12C 5 Gy, 14N 5 Gy, and 20Ne 1 Gy. The frequencies of variegated mutants including pale green leaves*1

Flower Division, Suntory Ltd.

*2 Institute for Fundamental Research, Suntory Ltd.

130

Fig. 1. Variegated mutant from surfinia 'Blue Vein.'by the first in vitro selection were 18.9%, 26.8% and10.8% isolated by 12C, 14N, 20Ne irradiations, respectively. We obtained many regenerated shoots from leaf
disks of these variegated leaves in MS medium with
1 mg/l BA and 0.1 mg/l NAA. It was observed thatmost of the regenerated shoots showed normal or albino leaves , but some of them showed un-chimericalvariegated leaves with quite a low frequency. As aresult, we successfully isolated one and four mutants(Fig. 1) of variegated plants from in vitro and in vitro
regeneration selections, respectively.
These results indicate that heavy-ion beam irradiation and its related selection system using in vitro
tissue culture techniques are powerful tools for the isolation of variegated Petunia.

RIKEN Accel. Prog. Rep. 35 (2002)

Induction of mutation in Sandersonia aurantiaca Hook. by
heavy-ion beam irradiation
M. Horita,* K. Sakamoto, T. Abe, and S. Yoshida
Sandersonia (Sandersonia aurantiaca Hook.) belongs to the Liliaceae family, and is the only species in
its genus, however, less intra-specific variations can befound in this species. Thus, there is no variety in the
Sandersonia currently available on the market. Interspecific hybrids of the genus can not be made. Sandersonia is only available in orange. Mutation breeding is
considered to be an effective method to develop new
varieties in such cases. We applied the heavy-ion beamirradiation method which has been reported to be aneffective mutagen in many plant species.
Dry seeds of Sandersonia were irradiated with 14N_
ion beams at doses rates of 20, 50, and 100 Gy, respectively. Embryos were excised from irradiated dry
seeds, and cultured on a modified Murashige & Skoog
medium at 22°C . The embryos germinated within one
month and grew in culture vessels up to the two-leaf
stage. Then, they were transferred to potted soil andgrown in a green house. The influence of irradiationon the germination rate of embryos and the inductionof mutation of M1 plants was evaluated.
The germination rate of embryos was not influenced
at a dosage rate of 20 Gy. A dosage rate of 50 Gy
slightly decreased the germination frequency of embryos and a rate of 100 Gy decreased the germination
severely (Table 1). Mutation characteristics were 0 bserved in 9 out of 432 plants with 20 Gy irradiation,
which was 2.1 % of the mutant appearance frequency.
Among 9 plants, some albino plants could be seen in
the culture vessels. Although 50 Gy irradiation wasslightly inferior to that of 20 Gy in terms of the fre-quency of induction of mutants, 6 mutants out of 346
plants were obtained. A dosage rate of 100 Gy irradiation produced only one mutant from 109 plants. These
results suggest that dosage rates of 20 Gy or less are
suitable for the induction of mutant plants in the caseof dry seed treatment of Sandersonia. Mutation characteristics observed in the Ml generation were albino,
striped leaf, dwarf and deformed leaf (Fig. 1). These
results show that heavy-ion beam irradiation is effective for the induction of mutations in Sandersonia, atleast in the leaf stage. Flowering was not observed in
M1 plants , therefore mutation in flower color remains
to be evaluated. However, these mutant plants, among
other plants, formed tubers.
We are now investigating the appearance of mutant
plants particularly in terms of flower color in the M2
generation.

Fig. 1. Mutated plants of Sandersonia induced by 14N
heavy-ion beam irradiation. Albino plant (left) andplant with striped leaves (right).

Table 1. Effects of 14N heavy-ion beam irradiation on Sandersonia.
Irradiationdose (Gy)

20
50
100

No. ofculturedembryos

No. ofgerminatedembryos (%)

No. ofalbino plants

No. ofstripe-lea f plants

Others*

720
784
791
56

432 (60.0)
346 (44.1)
109 (13.8)
33 (58.9)

5
5
0
0

2
1
1
0

2
0
0
0

Cont. **
* Dwarfed plant and plant with deformed leaves* * Untreated embryo

Hokkaido Green-Bio Institute131

RIKEN Accel. Prog. Rep. 35 (2002)

Mutation induction In human cells after low-dose exposure to
heavy ionsS. Morimoto, T. Kato, M. Honma,* M. Kase, F. Hanaoka, and F . Yatagai

It is very difficult to detect biological effects of lowdose ionizing radiation, particularly those of heavy-ion
radiation. However, it is highly desired to obtain suchinformation not only for estimation of radiation risk
to human body but also for basic understanding ofcellular responses.
Our previous studies have revealed unique characteristics of cellular responses and genetic changes in
the human lymphoblastoid cell line TK6, after a relatively high-dose heavy-ion exposure. For example,
mutation induction in the hypoxanthine phosphoribosyltransferase (HPRT) gene,l) p53 induction,2) and cell
cycle arrest 3 ) were extensively examined using this cellline. We extended this line of work to low-dose radiation exposure such as 10 cGy exposure and determinedout that the number of p53-induced cells depends on
the kind of heavy ion. 4 )In this study, we applied loss-of-heterozygosity(LOH) analysis 5 ) to the mutants at the heterozygous
thymidine kinase (T K) locus to elucidate the genetic
effects of low-dose radiation exposure in more detail. We considered this analysis very attractive because the type of LOH provides information about the
LOH induction pathway, homologous recombination or
DNA nonhomologous end-joining, through which DNA
double-strand breaks (DSBs) can be repaired (Fig. 1).
TK6-20C cells were irradiated with 10 cGy of X-rays
or C ions and the observed mutation frequencies (MF)at the T K locus are summarized in Table 1. The LOH
analysis demonstrated an increase in the relative por-tion of hemizygous LOH among all the number of TK
mutants, i.e. , 10 to 42% by X-ray exposure (Fig. 2),
although there was no significant increase in MF (Table 1). Furthermore, C-ion exposure enhanced suchproportion to 58% (Fig. 2), resulting in more than
twofold increase in MF (Table 1).
These results indicate that radiation-specific induction of hemizygous LO H is more efficient after exposure to C ions than the X-ray exposure. This finding
suggests that DSBs are more frequently produced by
22 keY / f-Lm C-ion exposure than by X-ray exposure. 6 )This assumption is consistent with our previous resultthat the number of p53-induced cells after 10 cGy of
22 keY / f-Lm C-ion exposure is higher than that after Xray exposure. 4 ) Alternatively, DSBs produced by C-ion
exposure are more complicated than by X-ray exposureand the difficulty in repairing such complicated DSBs
might produce hemizygous LOH more efficiently. At
present, we are analyzing the LOH pattern in moredetail using the satellite marker on chromosome 17 tofurther clarify the radiation exposure effects.

Background

X-ray 10 cGy

C-Ion(22keV/~m)

10 cGyFig. 2. Population of non- , hemizygous, and homozygous
LOR mutants after X-ray or C-ion (22 keY / J..lm) exposure. 110 mutants were determined for Background , 92
for X-ray, and 67 for C-ion exposure.

Hemizygous LOH
Typel

Type 2]f~)j~Ji0J~
TKm: NF (Non functio nal)
TK : F (Functional)~

Shorter ChromosomeorTranslocation

Treatment

Homozygous LOH
Type-l

TV~2

NF F

NF F

JLJL

No Chromosomal
Change(Gene Conversion)

Fig. 1. A model of expected loss of heterozygosity (LOR) ,which is induced by double-strand breaks (DSBs) . DSB
repair through end-joining could produce hemizygous
LOR, while that through homologous rejoining could
produce homozygous LOR. Both types of LOR haveno functional allele.
Division of Genetic Mutagenesis, National Institute of
Health Sciences

132

Table 1. T K Mutation frequencies induced by 10 cGy of
X-ray or C-ion exposure.

Background
X-ray
C-ion (22 keY / J..lm)

Mutation Frequencya(x 10- 6 , mean ± SD)
5.7 ± 1.3
6.9 ± 2.8
17.9 ± 8.9a) Obtained from three independent experiments

References
1) Y . Kagawa et al.: Mutagenesis 14, 199 (1999).
2) A. Gordon et al.: RIKEN Accel. Prog. Rep. 33, 131(2000) .
3) S. Goto et al.: RIKEN Accel. Prog. Rep. 34 , 176 (2001).
4) S. Morimoto et al.: RIKEN Accel. Prog. Rep. 34, 177(2001) .
5) M. Ronma et al.: Mol. Carcinog. 28, 203 (2000).
6) T. Fujisaki et al.: RIMAC Rep. 110 (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Delayed cell-cycle progression following exposure to heavy ions
S. Goto,* S. Morimoto, M. Kase, and F. Yatagai
High-LET (linear ~nergy transfer) radiation is oneof the tools for tumor treatment, but it is not as popular as X-ray irradiation. Compared to X-ray irradiation, the basic mechanisms responsible for such cellulareffects are still not well understood. For better understanding of cellular effect, cellular responses after
exposure of human lymphoblastoid cell TK6 to 3 Gyof C ions (22 keY / /.Lm) or Fe ions (1000 keY / /.Lm) were
examined in this study.
Cell-cycle progression after exposure was determinedby laser scanning cytometry (LSC). G2/M-phase cells
accumulated in all cases of irradiation. Comparedto X-ray irradiation, the number of accumulated cells
was less in the G2/M-phase after Fe ion irradiation(Fig. 1 (A)). This measurement did not confirm thefollowing possibilities that a) the cell-cycle progression irradiated cells was arrested in the S-phase anddid not proceed to the G2/M-phase , and that b) they
were not accumulated in the G2/M-phase during a certain period. Therefore, we prelabeled S-phase cellswith BrdU before the exposure, and monitored thecell-cycle progression of these labeled cells. By LSC
analysis, we could visualize the pattern (Fig. 1 (B))
that indicates the position of the labeled cells in thecell-cycle. Moreover, the rate of progression of the labeled cells from the S-phase to the G2/M-phase canbe calculated as shown in Fig. 1 (C). The S-phase cells(A)

exposed to Fe ions showed delayed progression to theG2/M-phase (Fig. 1 (B) and (C)). Such delay is probably due to the difficulty in repairing the so-called clus-

1 1 (ll l ll/lll lt h.11

"1',11~~Time after irradiation (hrJ

Fig. 2. Different patterns of Rad51 focus distribution between X-ray and Fe ion irradiation. At the indicatedpost-irradiation time, the cells were stained with theRad51 rabbit polyclonal antibody. The Rad51-fociformation pattern was determined by fluorescence microscopy. The photographs show examples of two different types of fo cus formation pattern (Type A and
B). Type A is the localized formation pattern and type
B is the uniformly distributed formation pattern. The
histogram is expressed as a percentage of cells forming
Rad51 foci. Each column in the histogram consists oftypes A and B focus formation patterns.

(C)Time after irradiation (hr)Fig. 1. (A) Cell-cycle progression in TK6 after irradiation with X-ray, C ions (22 keY / /Lm), and Fe ions(1000 keY / /Lm). Following the irradiation, cells were fixed with ice-cold methanol at each postirradiation time and the nuclear region of the cells was stained with propidium iodide (PI). Cell-cycle
distributions were analyzed by laser scanning cytometry (LSC). The population of cells in the G2/Mphase is expressed as a relative percentage with respect to that in the G2/M-phase of the unirradiated sample. (B) Cell-cycle progression of prelabeled S-phase cells after irradiation with X-ray, C
ions (22 keY / /Lm), and Fe ions (1000 keY / /Lm ). Before irradiation, S-phase cells were prelabeled with
BrdU for 15 min. Nine hours after irradiation, the position of the labeled S-phase cells in the cell
cycle was determined by LSC. (C) The proportion of cells that progressed from the S-phase to theG2/M-phase 9 hours after irradiation was calculated from the results of LSC analysis.
Department of Health Science, School of Pharmaceutical
Science, Nagasaki University

133

tered DNA damage 1 ,2) caused by exposure to highLET heavy ions. We also examined the in situ distribution of the Rad51 protein, which localizes at sites of
the DNA double-strand breaks and repairs the breaks
by DNA homologous recombination. The localizationof Rad51 was visualized as a focus using the antibody
against Rad51. The majority of Rad51 foci formed
after Fe ions irradiation showed a localized formation
pattern (Fig. 2, Type B), in contrast to those induced
mainly by X-ray irradiation that showed a uniformly
distributed formation pattern (Fig. 2, Type A). Furthermore, the proportion of Rad51-foci-formed cells
was maintained at the induced level even 18 hours af-

134

ter the exposure. In contrast, such proportion after
X-ray irradiation returned to the unirradiated level.
These results obtained from the cell-staining experiments also support the possibility that the DNA damage induced by Fe ion irradiation is clustered. Suchdamage might provide a delay in the cell-cycle progression due to the difficulty in repairing the clustered
DNA damage as mentioned above.
References
1) B. Rydberg: Rad. Res. 145 , 200 (1996).
2) W. R. Holley and A. Chatterjee: Rad. Res. 145, 188(1996) .

5. Instrumentation

RIKEN Accel. Prog. Rep. 35 (2002)

Developement of the in-flight separator CRIB
Y. Yanagisawa, T . Teranishi,*l S. Kubono, *l S. Michimasa,* l M. Notani,*l Y. Ohshiro,*l S. Shimoura,*lK. Ue ,*l S. Watanabe,* l N. Yamazaki, *l S. Kato, *2 T. Morikawa,*3 Y. Mizoi, T. Kishida, H. Iwasaki,*lH. Baba,*4 A. Saito,*4 Y. Satou,*l M. Kurokawa,* l and M. Kasethe secondary target position. The particle identification for secondary beams realized by a combination oftime-of-flight (TOF) and energy loss (6.E or E) measurements. The TOF is measured between RF signals
from the AVF cyclotron and the timing signal of the
PPAC. Silicon detectors are placed at Fl and F2 tomeasure energy losses.
The first test experiment was performed for producing a l2N beam for the experiment of l2N +P elastic scattering.3) A primary beam of lOB at
7.8 MeV jnucleon with an intensity of 200 pnA bombarded a 3He gas target with 0.25mgjcm 2. The l2N
beam was produced via the eHe,n) reaction in inverse

We reported the installation of an in-flight lowenergy radioisotope (RI)-beam separator CRIB lastyear.1) In this report , the results of test experiments
for the production of t he RI beam and beam devices
installed for measuring the beams are described.
CRIB consists of seven magnets and two focal planes
with the configuration of FO-QI-MI-DI-Q2-FI-D2M2-Q3, where FO is the production target position.
The principle of RI beam separation is based on magnetic rigidity analysis and the energy loss of fragments.
RI beams produced at FO are analyzed with their momenta and transported to the dispersive focus plane
Fl. A degrader is placed at Fl to generate the energy
loss. Next, RI beams are reanalyzed and collected at
achromatic focal plane F2. With the in-flight separation method, the wedge-shaped degrader has been
widely used at the dispersive focal plane. In the caseof CRIB at low energies of a few MeV jnucleon, a suitable thickness for the degrader was a few mgjcm 2, inview of multiple scattering and energy straggling. Sucha wedge degrader is too thin to fabricate. We haveused a homogeneous degrader, an aluminized mylar
foil with a thickness of 1.7mgjcm2, for RI beam separation. The effect of the degrader is described by Ue
et al. elsewhere in this report. 2)
We have installed a beam diagnosis device at eachfocal plane. The profile of a primary beam at the
production-target position (FO) is measured with asingle-wire profile monitor and a ZnS beam viewer.
The beam profile of a secondary beam is measured
at Fl and F2 using delay-line parallel plate avalanche
counters (PPAC) with segmented horizontal and vertical cathodes. The PPAC at Fl is used for the momentum measurement, and the one at F2 is for monitoring the isotopic separation and tuning beam profile atU()(),......,(/)+-' 1100
.t:

::J

-e
.3

11 C

1000

(/)

(/)

0

800

>bD
~

Q)

t:

(IX)

LU

«XJ
30

50

60

70

8()

TOF [arb. un its]

Fig. 1. Particle identification spectrum for the result of
production of l2N. The x-axis represents a TOF between RF and PPAC signals and the y-axis represents
an energy loss of particles in the silicon detector.

Table 1. Summary of RI beams obtained by CRIB . Here, primary beam intensity was 200 pnA .
RI beamPrimary beam
Energy (per nUcleon)
ReactionTargetIntensi ty (cps)Energy (per nucleon)
*1

*2

*3
*4

lOC
lO B 4+llC

7.8 MeV(p,n)
CH 4
1.3mg/cm 2
1.6 X 105
6.1 MeV

7.8MeVeHe,pn)3He0.25mg/cm 2
1.6 X 10 4
3.4 MeVlOB 4+

l2N
lOB 4+

14 0

7.8 MeV
eHe,n)
3He
0.25 mg/cm 2
2.5 X 10 3

8.4 MeV(p,n)
CH 4
1.3mg/cm2
8 X 105
6.7MeV

3.9 MeVl4N 6 +

Center for Nuclear Study, University of Tokyo
Yamagata University
Kyushu University
Rikkyo University

135

kinematics. The RI beams produced were separated
and transported to F2. Figure 1 shows a particle identification spectrum for the 12N beam. Particles wereidentified using the technique of TOF measurement
between RF and the timing signal of the PPAC andthe energy loss signals from the silicon detector. The
12N beam of 2500 cps was obtained. The purity of 12N
beams was about 3%. The main contamination of thebeam was a scattered primary beam from the wall of
the first dipole magnet. We have also performed experiments for producing the RI beams llC, lOC and 14 0 .
The RI beams obtained are summarized in Table l.
The development of a Wien filter installed after F2

136

and a windowless gas target 4) for a production target
is now in progress , being essential for the productionof high-intensity RI-beams with high purity.
References
1) Y. Yanagisawa et al.: RIKEN Aeeel. Prog. Rep. 34, 183(2001).
2) K. Ue et al.: RIKEN Aceel. Prog. Rep. 35, 137 (2002).
3) T. Teranishi et al.: RIKEN Aeeel. Prog. Rep. 35 , 60
(2002).
4) T. Kishida et al. : Nuel. lnstrum. Methods Phys. Res. A
438, 70 (1999).

RIKEN Accel. Prog. Rep . 35 (2002)

Test of low-energy RI beam production with CRIB
K. Ue,*l S. Kubono,*l T. Teranishi,*l S. Shimoura,*l M. Notani,*l Y. Yanagisawa, S. Michimasa,*lH. Iwasaki,*l M. Kurokawa,*l Y. Satou,*l T. Morikawa,*2 A. Saito,*3 H. Baba,*3
Y. Ohshiro,*l N. Yamazaki,*l S. Watanabe,*l and M. Kase
To establish a technique of producing a low-energy
RI beam by means of the in-flight method, we haveconducted a test experiment to produce an 140 beam
at low energy (6.6 A MeV) using a homogeneously thindegrader for isotope separation. We studied the achromaticity of the RI beam at t he exit of CRIB separator. 1)
A wedge-shaped energy degrader with the thicknessof 100-1000 mg/ cm 2 has been widely used for the inflight method at intermediate energies. The use of awedge-shaped degrader allows one to achieve achromaticity easily. However, the suitable thickness is 110 mg/cm 2 for such a low beam energy. Because it
is difficult to constract a wedge-shaped degrader withsuch a small thickness, we tested a method using ahomogeneously thin degrader. The use of a homogeneous degrader breaks the achromaticity. We treatedthe effect of particle energy-loss in the degrader in theframework of the ion-optical transfer matrix and adjusted the optics of CRIB , so that the achromaticity
could be restored. 2)
A primary beam of 14N at 8.4 A MeV bombarded
a gas target of 1.5 mg/cm 2 CH 4. The target gas was
confined in a small cell with entrance and exit windows
made of Havar foils (2.4J-lm thick). An 14 0 beam produced by the 14N (p, n) 14 0 reaction in inverse kinematics was separated from other particles by CRIB.
We installed an aluminized mylar foil with thickness
1. 7 mg/ cm 2 as the homogeneous degrader at the dispersive focal plane (Fl) of CRIB. At the achromatic
focus (F2) , particle identification was performed using
timing information from two parallel plate avalanche
counters (PPAC)3) and energy information (E) from asilicon detector. The beam profile and position at F2
were measured using the PPACs.
The beam purity of 14 0 at F2 was about 60% without the degrader and about 80% with the degrader.
The main background was 14N scattered from the wallof the first dipole magnet of CRIB, the beam pipe andthe target cell.
To verify the achromaticity, the horizontal centroid
position of the 14 0 beam was measured at F2 as a function of its momentum. The momentum was selected at
Fl by using an aperture of 2 mm, which corresponds tothe momentum spread of 0.13%. The aperture position
was moved from 0 to 50 mm. Figure 1 shows the centroid position at F2 (X2) as a function of aperture posi*1 Center for Nuclear Study, University of Tokyo*2 Kyushu University*3 Rikkyo University

so

I

0

I

I

without degrader

-

20-

<>
10-

0

S

..§.

with degrader. with re-tuningwith degrader. without re-tuning
O

D-

~N
-10 -

ffi

0

8

0

0

8

8

<>

-

-

<>
-20 -

-

<>
<>

-30
-80

I

I

-40

-20

I

Xl [mm]Fig. 1. Vertical and horizontal axies show the horizontal
centroid position of the beam spot at F2 (X2) and of
the aperture at F1 (Xl ), respectively. The positions
Xl = 0, -10, - 20, - 30, -40, and -50 mm correspond
to 0, -0.63, - 1.3, -1.9, -2.5, and -3.2%, respectively,
in deviation from the central momentum.
Table 1. Properties of 14 0 beam produced by using
He 4N,140)n reaction at 8.4 AMeV. The intensity of
the 14N beam was 500 pnA.
EnergyIntensity
Momentum spread
PuritySpot size (FWHM)

6.6 AMeV
2 x 10 6 pps
5%80%¢ 14mmtion at Fl (xd. When the degrader was not used, theshift of X 2 was measured to be 8 mm at Xl = -50 mm.
When the degrader was used and the optics was adjusted, the shift was 9 mm at X l = -50 mm. Both values of shift were significantly smaller than X2 = 25 mm
at Xl = -50 mm with the degrader and without the adjustment. Therefore, the adjustment of the separator
system is important for the use of the homogeneously
thin degrader. The properties of the 14 0 beam aresummarized in Table 1. The spot size with the degrader was wider by 5 mm than that without the degrader. This is mainly due to a large energy straggling
in the degrader.
References
1) Y. Yanagisawa et al.: RIKEN Accel. Prog. Rep. 34, 183(2001) .
2) S. Mitsuoka et al.: Nucl. Instrum. Methods Phys. Res.
A 372 , 489 (1996).
3) S. Kumagai et al.: Nucl. Instrum. Methods Phys. Res.
A 470 , 562 (2001).

137

RIKEN Accel. Prog. Rep . 35 (2002)

The first observation of slow muon beamat the RIKEN-RAL Muon Facility
Y. Matsuda, P. Bakule, Y. Miyake,* K. Shimomura,* S. Makimura,* P. Strasser,
T. Matsuzaki, K. Ishida, 1. Watanabe, and K. Nagamine
We have been constructing a slow muon beam line
at the RIKEN Muon Facility at the Rutherford Appleton Laboratory,l) adopting the resonant ionization
method. The advantage of a slow muon beam over conventional muon beam is enormous. The energy of slow
muons can be varied from a few eV to a few tens of
keY , while the energy spread when they are generated
is on the order of a few e V. On the other hand, thecurrently available muon beam (surface muon beam)
has a fixed momentum of approximately 27 MeV / c (energy 3.5 MeV) and its momentum spread is as large as
10%. The nature of the slow muon beam will extend
t he application of p'sR studies to thin films, surfaces
and interfaces which have been impossible to be investigated with jLSR technique . The t ime resolution will
also be much improved compared to that of the current
beam available at the RIKEN Muon Facility, thanks to
the narrow t ime width of the laser beam which is used
to generate the slow muon beam.
The resonant ionization method was developed att he Meson Science Laboratory of the High Energy Accelerator Research Organization. 2 ) The surface muon
beam is injected into a thin tungsten foil, which isheated to approximately 2500 K. Muonium atoms withthermal kinetic energy are evaporated from the surface
after its format ion following electron capture at thesurface of the foil. Then the electrons of the muonium
atoms are removed by irradiation with VUV laser toproduce very slow muons. This process is illustrated
in Fig. 1. Generated slow muons are extracted andaccelerated by SOA lenses and transported to a microchannel plate (MCP) detector, with which they aredetected.
We ionized muonium through a series of two transitions , Is-t2p and 2p-tunbound. A sophisticatedlaser system has been developed to generate an intense
Lyman-a VUV light which matches the energy difference between the Is and 2p states, which corresponds
to the wavelength of 122.09 nm in the case of muonium.
Another 355 nm of photons from a frequency-tripled
Nd:YAG laser were used to remove electrons throughtransition from the 2p state to an unbound state. The
scheme is illustrated in Fig. 2. A detailed explanationof t he laser system is given in the previous report. 1)
We carried out the experiment in the summer of2001 for 5 days in the Port 3 experimental area at the
RIKEN Muon Facility. The first slow muon beam was
successfully observed at t he beam line. An observed
Institute for Materials Structure Science, High Energy Accelerator Research Organization (KEK)138

muonium..
••muon beam

..

..

..
tungsten film
laser light
Fig. 1. Schematic diagram of the laser ionization method
for generating slow muons.

Fig. 2. Schematic diagram of the laser system which has
been developed for the resonant ionization of muonium
atom.

time-of-flight (TOF) spectrum is shown in Fig. 3.
It is noted that the laser system is operating with a
25 Hz repetition rate, whereas the pulsed muon beam
has a 50 Hz repetition rate. We observed a clear peak
only when VUV light was introduced to the production
region. The signal was confirmed to be caused by slow
muon from the measurement of the bending magnet
field in the beam transport line, and by agreement of
the TO F difference between laser irradiation and signal
arrival time according to acceleration voltage. In orderto change the wavelength of the VUV light , the frequency of a t unable OPO laser was scanned. Figure 4
shows that the yield of slow muon peaked at 820.4 nm,
which corresponds to t he matching frequency of theI s-t 2p transition of muonium atoms.
It was observed that the yield almost linearly de-r------------------------------

40
35
30
25
20
15
10

750

1000

1250

1500

1750

2000

2500

MCP TOe with loser (nsec)

40
35
30
25
20
15
10

5 :..
0

750

500

1000

1250

1500

1750

2000

2250

2500

MCP TOC without loser (nsec)

Fig. 3. Typical slow muon signal is shown. The uppergraph shows the TOF spectrum of the MCP detector
when laser lights are introduced in to the production
region, and the lower graph shows the spectrum whenlaser lights are not introduced.
60

t

50
40

~

17

ed

peak position.....

... . ...•. • .• .'1• .•.

~ 30
0

u

1

20
10

,t

0
820

820.2

820.4

820.6

820.8

821

Wavelength (run)Fig. 4. Yield of slow muons are plotted against frequencyof tunable OPO laser . The wavelength was calibrated
by He-Ne laser and by observing hydrogen ionization
signal at 844.8 nm.

pends on both VUV laser power and 355 nm laser
power, suggesting that laser power was not saturated

in the production region.
The obtained count rate of slow muon was about
0.03 slow muons/sec , which is about 30 times smaller
than expected. We believe that this is largely due
to the smallness of the power of the VUV light and
355 nm light which ionize the muonium atoms. We
monitored the strength of the VUV light by observing an ionization signal from NO gas which is filled
in a chamber located at the end of the laser path.
The signal during the beam time was less than 10%of what we obtained during the commissioning period
in Japan. The 355 nm laser was operating at approximately one third of its maximum power because ofa fault in its power supply. The vacuum around thetarget was about 5 x 10- 8 mbar, which is also poorer
than that in our design due to the short period of baking time. although this level of vacuum will not disturb
the slow muon trajectory markedly, it will deteriorate
the cleanness of the surface of the target, which willaffect the efficiency of muonium production.
We are currently working to improve laser performance. It has been indicated that a lower intensity
of VUV light was caused by the strong focusing oflaser beams in the Kr chamber, which causes saturation of VUV generation. By slightly defocusing thelaser beams to obtain a larger generation area, we expect to obtain significantly stronger VUV light. In thelast beam experiment, we split the 212 nm laser into
two, and used only one of them to avoid damage on
a BBO crystal in the laser system. We are planning
to use the second 212 nm laser light with a new BBO
crystal to introduce another VUV light to the chamber.
The power supply of the 355 nm laser has been fixed
to yield maximum power. Improvement of the vacuum
system is also under way, including installation of acryopump, which was not available last summer.
With these improvements, we expect to obtain atleast 100 times more slow muons, which will be sufficient for j.LSR study of some samples. We are planning
to install a j.LSR spectrometer in 2002.
References
1) Y. Matsuda et al.: RIKEN Accel. Prog. Rep. 33 , 263(2000) .
2) K. Nagamine et al.: Phys. Rev. Lett. 74, 4811 (1995).

139

RIKEN Accel. Prog. Rep. 35 (2002)

Design of a spin polarized positron beam and a spin rotator
F. Saito, N. Suzuki, Y. Itoh, A. Goto, Y. Nagashima,*l T. Kurihara,*2 and T. Hyodo*lA high-intensity spin polarized slow positron beam isdeveloped in RIKEN for the researches of surface andof interface magnetism. A high-intensity beam can beattained by using an electrodeposited 18F (producedby the AVF cyclotron) positron source 1) and a highefficiency tungsten mesh moderator. 2)
The specifications of the beam transferring system
was already reported;3) the positron spin is rotated byusing a spin rotator. A polarimeter is used to measure
the positron spin polarization of the beam. The previous design ,3) however, requires some improvements.
In this paper, the simulation of beam transfer of a new
designed apparatus as well as a magnetic field and anelectric field of the spin rotator are reported. The electric and magnetic fields of the spin rotator were optimized by means of OPERA-3d/TOSCA (Vector Field,Ltd.). The beam transfer efficiency was simulated bymeans of Simion (Idaho N. E. Lab.).
A Wien filter is used as a spin rotator which has astatic electric field (E) and a magnetic field (B) perpendicular to the beam axis and to each other. Whenthe beam passes through the magnetic field, the spinrotates in the magnetic field direction due to the Larmor precession. The transverse motion of the positronis restrained by the electric field when the Wien condition e( E + v x B ) = 0 is satisfied. Thus, the adjustment of the magnetic field and the electric field
is of vital importance for the beam transfer efficiency.
The dimensions of the designed spin rotator are 50 mm
length along the beam axis, 20 mm gap between magnetic pole pieces and 16 mm gap between electrodes.
The diameter of the beam passing the rotator is about
10 mm. The schema of the spin rotator is shown in
Fig. 1. The deviation of the magnetic field and theelectric field along the transeverse direction (x-axis)
at the center (z = 0) of the spin rotator is shown in
Fig. 2. The electric field produced by the curved surface electrodes corresponds better to the magnetic fieldyx~zpole piecee+curved surface e lectro deFig. 1. Schema of spin rotator. The origin of the cordinates
is the center of the spin rotator.
*1
*2

140

Department of Basic Sciences, Graduate School of Arts andScience , University of Tokyo
Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)

1.2
en

'i:i

---

1.1

:::l

..ci

~

~ O.
~

-

::9 O.

E field (curved surface)t1j

E field (plate)

-

4
x[mm]

2

y=O, -

y=4- - - y=O, . . .. y=4

6

Fig. 2. Deviation of electric fields and magnetic fields , eachnormalized by the value at (x,y) = (0,0).

- _ - - Magnetic fieldwith field clamps.. Magnetic field
without field clamps

24z [cm]

6

Fig. 3. Fringing magnetic field and electric fields, each normalized by the value at the center of the rotator. The
end of the rotator and the field clamp are situated at
2.5 and 4 cm from the center, respectively.

than that produced by the plate electrodes at positions
along the x-axis with y = 0 and y = 4.
Figure 3 shows the simulation of the magnetic fields
with and without field clamps and the electric fieldalong the beam axis. The width of the fringe magnetic
field at the entrance and the exit of the rotator can be
reduced and adjusted to that of the electric field byemploying field clamps.
The simulation of the beam transfer efficiency shows
all the positrons emitted from a circlar area (dia.
6 mm) with an energy of 1- 3 eV and an angle of 0- 80
degrees to the beam axis can be transported to thetarget sample.
In conclusion, the design of the spin-polarized slow
positron beam apparatus has been completed and thesimulation shows that this apparatus exibits high beamtransfer efficiency.
References
1) F. Saito et al.: Nucl. lnstrum. Methods Phys. Res. A
450, 491 (2000) .
2) Y. Nagashima et al.: Jpn. J. Appl. Phys. 39, 5356
(2000).
3) J. H. Kim et al.: Rad. Phys. Chern. 52 , 759 (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

On-line collection of 8Li ions from the projectile fragment
separator using an rf-ion guide system
M. Wada, Y. Ishida, T. Nakamura, Y. Nakai, T. M. Kojima, Y. Kanai, N. Ohshima, H. Ohyama, T. Kambara,
Y. Yamazaki, A. Yoshida, T. Kubo, Y. Matsuo, Y. FUkuyama, K. Okada,*l T. Sonoda,*2 K. Noda,*3
H. Kawakami,*4 S. Ohtani,*5 and 1. Katayama*4
The projectile fragment separator (RIPS) at the
RIKEN accelerator facility (RARF) provides a wide
variety of energetic radioactive beams. However, it is
not adequate for low-energy beam experiments such as
precision spectroscopy of trapped ions . Aiming at efficient deceleration and cooling of the energetic radioactive ions, the development of an rf-ion guide systemcomprising a large He gas cell and an rf funnel structure in the cell is in progress. 1- 5 ) Energetic ion beams
from the fragment separator are stopped in the gas cell
after passing through an energy degrader. In the conventional ion guide, the transport of ions in the cell iscarried out only by the gas flow which limits the possible size of the cell. In the rf-ion guide, on the other
hand, the ions in the cell are under the control of theapplied dc and rf fields , which enables us to use a largecell. The dc field transports the ions toward the exit
aperture, while the rf gradient field at the wall of thecell repels the ions.
A proof of the principle (pop) machine has been successfully tested on-line for the collection of 70 MeV lu
8Li ions. The setup used in the test experiment isshown in Fig. 1. A compact gas cell of 70 cm in lengthand 10 cm in diameter with a He gas pressure of 30 Torr
was placed after a newly developed wedge shaped energy degrader. The degrader is made of water packed
between thin aluminium windows connected by bellows. This arrangement is capable of varying both thewedge angle and the thickness. A photograph of thewedge degrader is shown in Fig. 2.
The ions stopped in the gas were extracted orthogonaly to the beam axis by the dc field penetrating fromthe rf funnel structure. The ions follow the lines of electric force toward the surface of the electrode, although
they do not hit the electrode due to the presence ofthe rf barrier field. In this way the ions move slightly
above the surface of the funnel structure toward theexit aperture of 0.5 mm in diameter.
The transported 8Li ions were collected on a silicondetector and delayed-a decay was observed for theirdetection. The overall efficiency of the pop system was---- 10- 4 as depicted in Fig. 3. The radial acceptance ofthe cell for the extended beam after the degrader wasmeasured to be 30% using a collimated beam. The
stopping capability of the 30 Torr gas cell was 0.43%
which was deduced from a range calculation by using the TRIM code, the measured energy distribution
after the energy degrader, and the radial acceptance.
Thus the overall efficiency can be separated into thegas stopping efficiency of 0.43% and the ion-guide efficiency of 2.4%. The former is limited by the geometryof the cell and the pressure of the He gas. The latter is due to the present rf voltage limitation of 40 V.
Both components have the potential to be increased
up to the 10% range by employing a larger cell, higher
pressure, and higher rf voltage, which would yield an

Fig. 1. Diagram of the rf ion guide on-line test setup.
*1
*2

*3
*4
*5

Department of Physics , Sophia University
Cyclotron RI Center , Tohoku University
National Institute for Radiological Science
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK)
Institute for Laser Science, University of ElectroCommunications

Fig. 2. Wedge shaped energy degrader of variable angle
and thickness.

1411.210-<1
1 10""•
11

g8 10-5 E:~Kst@~~~ .",.'1 ..,.', .':... •.,..... ...... :.,.

.~==
~ 610.5~0 410 .5
210 050100 ~~~~
o

0.2

0.4

0.6

0.8

1.2

RF reference amplitudeFig. 3. Overall efficiency (= detected a/RIPS output) plotted as a function of applied rf voltage. The reference
value of 1.0 corresponds to about 40 V.

Fig. 4. New rf electrode assembly made of planar PCB.
Part of the electrode is enlarged at the bottom right.
An additional small central electrode will be attachedat the center.

expected overall efficiency of 1%.
With this in mind a new large cell of 40 cm in diameter and 2 m in length has recently been installed.
In this new cell, the rf funnel structure was replaced
by a planar Printed Circuit Board (PCB) disk withfine ring electrodes (Fig. 4). The spatial period of thering electrodes is 0.5 mm and the disk is 260 mm indiameter. In the first on-line test of the new setup,the overall efficiency already exceeded 10- 3 , although
there was a vacuum leak in the cell which resulted ina poor background pressure of 10- 5 Torr. A typicalexperimental result is shown in Fig. 5. The overall efficiency is plotted versus the applied dc gradient field

142

Fig. 5. Overall efficiency of the new setup plotted versus
the applied dc gradient field and the rf amplitude.

and the rf amplitude. Since at the time of the firsttest a central part of the electrode assembly was notinstalled, we could observe some transported 8Li ionseven when the rf field was turned off. In this case afraction of ions stopped in the cell can be transportedby the dc field only, since the central apert ure is 14 mm
in diameter. The additional central part of the electrode made of a plane PCB of 0.2 mm thick with a fineelectrode structure and a small exit aperture of 0.5 mm
in diameter is under fabrication.
Two types of downstream experimental instruments
are also in preparation. One is a linear rf trap for
precision spectroscopy of the hyperfine structure of
6
11 Be ions. ) The other is a multireflection time-of-flightmass spectrometer .7) They will be connected to thepresent rf ion guide system for future on-line experiments with unstable nuclear beams.
References
1) M. Wada et al.: Presented in Int. Workshop on Ion
Guide Isotope Separator On-Line (IGISOL-6), Dubna
1997, unpublished.
2) 1. Katayama et al.: Hyperfine Interact. 115 , 165 (1998).
3) M. Wada et al.: RIKEN Accel. Prog. Rep. 33 , 180(2000) .
4) M. Wada et al.: RIKE Rev., No. 31 , 56 (2000).
5) M. Wada et al.: AlP Conf. Proc. 606, 625 (2002).
6) T. Nakamura et al.: RIKEN Accel. Prog. Rep. 35 , 99
(2002) .
7) Y. Ishida et al.: RIKEN Accel. Prog. Rep. 35 , 157(2002).

RIKEN Accel. Prog. Rep. 35 (2002)

Development of RI atomic beam device
with a Laval-type nozzle
H. Miyoshi,*1 H. Veno, K. Asahi, H. Ogawa,*2 J. Murata, K. Sakai,*1 D. Kameda,*1 Y. Kobayashi, W. Sato,
A. Yoshimi, H. Watanabe, K. Yoneda, N. Imai,*3 J. Kaihara,*1 K. Shimada,*1 and T. Koike*1
A number of nuclear moments have been measured
at the RIKEN Ring Cyclotron during the last decade,using spin-polarized beams from the fragmentation reaction combined with nuclear magnetic resonance via
change in the angular distribution of {3 rays ({3-NMR
method). This approach, however, requires that several conditions be fulfilled.
To avoid the difficulties forecast for certain requirements when the measurement is extended to the heavier mass region, we have attempted to develop amethod which involves a low-energy spin-polarized radioactive isotope (RI) beam, which we call the RI
atomic-beam method (RIAB). The advantage of thismethod is that no special host material or {3-ray asymmetry is required, since the magnetic resonance is performed in-flight and the resonance is detected simply
by counting the radiations of the transmitted RI. A
schematic view of the total setup is shown in Ref. l.
A hexapole magnet is installed to converge the beamfrom the nozzle of the cell. In order to choose the fieldstrength of the magnet, we need to determine the range
of velocities at which the RI atoms emerge from thenozzle. As the first step toward this goal, we performed
an experiment to measure the total spout efficiency( i. e., stopping efficiency x spout efficiency) .
The experiment was carried out at RIPS. A 17N
beam was produced from the fragmentation of 18 0 projectiles on a 1.48 g/cm 2 thick 9Be target at an energyof EIA = 100 MeV lu.
First, the 17N atoms must be stopped by a noble
gas in a cell. We chose Ar for the stopping gas material. The temperature of the gas was kept as low
as 150 K. From our simulation, velocity ranges below
400 ml s are favorable for the RIAB technique. The
major factors determining this are the vacuum system
performance and the field strengths realizable with thehexapole magnet. The RI atoms are ejected from thecell together with the Ar carrier gas into vacuum. A
nozzle 2) was mounted on the exit of the cell so that thegas spouts out at forward angles. A schematic view ofthe setup including this Laval-type nozzle is shown in
Fig. 1.
In this experiment, we measured the counting rate of{3 rays from 17N with a plastic counter telescope. The
experiment was performed under two different conditions: the (3 particles were counted with and without*1 Tokyo Institute of Technology*2*3

National Institute of Advanced Industrial Science and Technology
University of Tokyo

liqN2

TMP

Fig. 1. Schematic view of the setup. The 17N beam is incident at the cell from the direction perpendicular to thefigure, and a fraction of atoms in the beam are stopped
in a gas in the cell. TMP: Thrbomolecular pump.

Table 1. Result of the experiment.
statusAr Flow
No Flow

BaF 2 (counts) Plastic (counts) R (= PlastiC)
Ba F 2

15923159
13163251

19385
15347

1.217 x 10- 3
1.166 X 10- 3

the Ar carrier gas flow. From the difference in the{3-counting rates between the two conditions, we ascertained the 17N atoms to indeed be extracted fromthe cell by the carrier gas. The experimental result isshown in Table 1.
The BaF 2 counter which counts scattering particles
such as r rays and neutrons was used as a 17N beam
monitor. The counter was located far from the RIAB
setup. From Table 1, a definite difference is observed
between the beam-normalized {3-counting rates R for
the gas flowing and non-flowing conditions. The difference , however , is not as large as expected, presumably because of a large background consisting of {3 rays
and neutrons which were emitted from 17N activities
stopped in the cell wall. The rate of 17N particles incident at the cell was counted with a beam counter (aplastic scintillator). From the observed difference in143

{3 countings, divided by the beam rate (normalized by
the BaF 2 counts) and corrected for the {3-solid angles,
we obtain a total spout efficiency (= number of extracted 17N atoms / number of incident 17N atoms) of
about 3.95 x 10- 7 . Since the momentum distribution of
the 17N beam was rather sharply cut at the RIPS momentum slit at the F1 focal plane (±3% at momentumpeak), we could estimate the fraction of the incident
17N particles that are stopped by a gas in t he cell. The
net spout efficiency, defined as the ratio of the number

144

of extracted 17N atoms to that of stopped 17N in thegas, is estimated to be 0.4%. Modification of the system (the shape of the cell, temperature, etc.) is under
way in order to improve efficiency.
References
1) H. Miyoshi et al.: RIKEN Accel. Prog. Rep. 34, 181(2001).
2) W. J. Hiller and W.-D. Schmidt-Ott: Nucl. Instrum.
Methods 139, 331 (1976).

RIKEN Accel. Prog. Rep. 35 (2002)

Development of a detector system for transient magnetic field
experiments
H. Ueno, W. Sato, H. Ogawa,*1 Y. Kobayashi, D. Kameda,*2 H. Miyoshi,*2 J. Kaihara,*2 N. Imai,*3
H. Watanabe, A. Yoshimi, K. Yoneda, and K. Asahi
For the g- factor measurement of short-lived (Tps) excited states of unstable nuclei, we are preparing
transient field experiments 1) using radioactive nuclear
beams. In this report, the annealing of thick ferromagnetic targets and development of a detector system forthe transient field 2) using a 22Ne beam are described.
For the preparation of ferromagnetic material, annealing of self-supported Gd foils with thicknesses oft = 25 and 100 p,m were employed.
After being
placed in the quartz-tube furnace, the foils were heatedat 1100 K for 10 minutes at a pressure of 1 x 10- 6
Torr. The heating power was then reduced slowly
and the foils were cooled to room temperature. Although hexagonal Gd shows magnetic anisotropy between the easy direction of magnetization and the crystallographic c-axis depending on the temperature, it
has been reported that well-annealed polycrystalline
foils show almost the same magnetization as the single
crysta1. 3) Magnetization of the Gd foils was measured
with a SQUID magnetometer as a function of the polarizing field Bext at T = 77 K. The measured magnetization as a function of temperature is shown in Fig. 1.
The obtained magnetizations of 4.5 and 4.1 in units ofP,B/atom for the samples with t = 25 and 100 p,m at
Bext0.03 T, at which the magnetization should besaturated if the sample is well-annealed, were foundto be inadequate compared with the reported value of
6.2 P,B/atom for t = 2- 4 mg/cm 2 thin foils. 3) This isdue to difficulties in the annealing of thick samples.
Thick foils , however, are needed for RI-beam experiments, so that development of another method of annealing is in progress.
The performance of the detector system, whose design is described in the previous report,1) was tested
using a 22Ne beam, in order to detect the particle-I' coincidence. The J7r = 2+ first excited state of 22Ne at
Ex = 1.275 MeV, whose magnetic moment and lifetime
are known to be p, = +0.65(2)P,N and T = 3.63(5)ps,
respectively, was populated by the scattering from a
50 mg/cm 2 thick Pb target. The average energy of the
22Ne beam was E = 12.9 MeV /nucleon, which corresponds to a beam velocity of v = 22.9va, where Va isthe Bohr velocity. Although the velocity might be excessive for the transient field experiment, the detector
system was tested in this situation, taking into accountthe fact that RI beams produced by the projectile fragt'V

5

E

!

4.8

E
Q)

4.6

E

o

E

4.4

()

~
c

4.2

Ol
01

tGd=25Jlm -~4L-__~__~__~~~=_
100~Jl~m_·_"·._·~"·~
0.025 0.03 0.035 0.04 0.045 0.05
Polarizing Field (T)Fig. 1. Measured magnetization of Gd foils with thicknesses of t = 25 and 100 11m at a temperature T = 77 K
as a function of the polarizing magnetic field.

7000

>

~

6000

.... 5000

It)

22Ne (2+ ~ 0+)1275 keY".
\" ',.

,"H++:"'.1'++

Cis,
tt ...

",C 4000

=

H.

0

(J

++ ....t++t+\...+....

3000

H~

t+tt+t+tt++.+t

2000

1000

1500

2000

Energy (keY)

t'V

*1

*2

*3

National Institute of Advanced Industrial Science and Technology
Tokyo Institute of Technology
University of Tokyo

Fig. 2. A , -ray spectrum obtained for the de-excitationfrom the 2+ first excited state of 22Ne after the Coulomb
excitation.

mentation reaction have very high velocities comparedto the Bohr velocity. In the experiment de-excitation I'
rays from the 2+ first excited state after the Coulomb
excitation were identified as a peak in the obtained I'
spectrum as shown in Fig. 2.
The observed large background, however, interferes
seriously with the determination of the photo-peakarea in the experiment with RI beams. To reduce thebackground, we are improving the detector system.
References
1) H. Veno et al.: RIKEN Accel. Prog. Rep. 33 , 190(2000).
2) R. R. Borchers, B. Herskind, J. D. Bronson, L.
Grondzins, R. Kalish, and D. E. Murnick: Phys. Rev.
Lett. 20, 424 (1968).
3) O. Hausser, H . R. Andrews , D. Ward, N. Rud, P. Taras,
R. Nicole, J. Keinonen , P. Skensved, and C. V. Stager:
Nucl. Phys. A 406, 339 (1983).

145

RIKEN Accel. Prog. Rep. 35 (2002)

Gas cell RI beam stopper with electric transportation system
J. Kaihara,*1 K. Asahi , N. Imai,*2 D. Kameda,*1 Y. Kobayashi, T. Koike,*l H. Miyoshi,*l J. Murata,
H. Ogawa,*3 K. Sakai,*1 W. Sato, K. Shimada,*1 H. Ueno, H. Watanabe, K. Yoneda, and A. Yoshimi

As part of the plan for building a radioactive atomic
beam apparatus (RIAB) with the goal of producing
highly polarized radioactive nuclei, 1) we performed
R&D of an ion-stopping gas cell, for the purposeof stopping the RI beam produced by the projectile
fragmentation reaction and separated by the RIPS
(RIKEN Proj ectile-Fragment Separator) at RIKEN.
In order to use the RI beam as an ion beam incident
to the RIAB, the beam momentum must be degraded,
and also electrically neutralized. In the year 2000, we
confirmed by a simulation study that the RIAB has
extensive potential for studies using polarized RI andwill be able to obtain nearly 100% polarization, which
gives us precise measurements of nuclear moments ina wide range of the nuclear chart, application to surface materials science, and also a test of fundamental
symmetries such as time-reversal invariance.
The most challenging technical part of the RIAB is
the ion stopper. A low-pressure gas cell ion stopper(LPGS) is located immediately in front of the RIAB
magnets, providing supersonic cold ion flows with a
Laval- type nozzle. 2 ) Because of its very low pressureof around 1 Torr, we cannot expect sufficient stopping
power and resultant transportation efficiency. The goalof the present study is to build another high-pressure
gas cell stopper (HPGS) located immediately in frontof the low-pressure gas cell in order to increase the efficiency. The incident ions are stopped inside the gas
volume (He gas , 730 Torr) , and then transported outside the gas cell through a small hole by an electricfield. We applied a unique electric field , which canlead the charged ions through a very localized output
hole with small loss. By utilizing electric transportation, we can solve the problem of severe contaminationof the carrier gas downstream. Also, the sufficiently
fast transportation time allows us to use short-lived
radioactive nuclei.
We built the first prototype chamber apparatus of
the HPGS after a simulation study, and it is shownin Fig. 1. The field pattern was optimized to achieve
maximum transportation efficiency. In order to obaina strong focusing force at the end point, a one-orderhigher field was applied there. A test using a radioactive source must be carried out as a first step . however,
because of the difficulties in achieving an ion-emitting
source and detecting the low-energy ions, we performed
a test experiment, using an ion beam at RIKEN in October 200l. We used 17N ions produced by projectile
*1

*2

*3

146

Tokyo Institute of Technology
University of Tokyo
National Institute of Advanced Industrial Science and Technology

Plastic "?--"'~II ...t1ULL~

Ri stopped
in this region

Copper Plate

Coiled Electrodet

RI-beamFig. 1. Schematic view of the setup. (The copper plates
are the shield for (3)fragmentation reaction of a 100 MeV lu 18 0 beam on
a l.48 mg/cm 2 9Be target, separated by RIPS at theE6 beam line of RIKEN Ring Cyclotron. The incident
beam energy at the HPGS is about 500 ke V lu after
degrading.
The transported ions are counted by two plastic
scintillation counters, which detect {3 particles emitted
from {3-unstable ions. By observing the field strength
dependence on the (3 counting rate, we can estimate
the transportation rate. Unfortunately, no clear evidence of the transportation was obtained in the firsttest experiment. 17N was not clearly observed. Possible reasons for this are ion neutralization due to gas
impurity, a low beam-stopping rate , a nonoptimal electric field, and charge-up of the glass cell.
Considering our experience with the test experiment , we are now attempting to change the design
drastically. For example, we will place electrodes inside a large gas volume instead of surrounding the glass
cell with electrodes. As a result , the apparatus canachieve a high vacuum level , therefore, the gas impurity problem should be significantly reduced. As regards the test procedure, a test without using an ion
beam should be performed for simplicity. Production
and detection of the helium ions using a mass separator
can advance our R&D.
Our efforts to modify the current HPGS system must
succeed within one year. The R&D of the LPGS andthe design for the magnets are successfully under way,
therefore , we can expect to see the first polarized radioactive atomic beam in the near future.
References
1) H. Miyoshi et al.: RIKE Accel. Prog. Rep . 34, 181(2001).
2) H. Miyoshi et al.: RIKEN Accel. Prog. Rep. 35 , 143(2002).

RIKEN Accel. Prog. Rep . 35 (2002)

RF deflector system for proton-rich RI beams (II)K. Yamada,* 1. Tanihata, and T. Motobayashi*
The construction of the RF deflector system reported previouslyl) is continuing to make progress.
The system is expected to be installed in the RIPS 2 )beam line to obtain high-purity proton-rich RI beams.
The secondary beam in the second stage of RIPS
passes through a vertically arranged parallel-electrode,to which a high voltage with half the frequency of thecyclotron RF signal is applied. The particles in the
beam are deflected depending on their arrival time at
the position of the electrodes, and are filtered by a
two-dimensional slit placed at the focal point.
The deflector system is shown in Fig. 1. It consistsof an electrode part, a two-dimensional slit system (2Dslit), a main amplifier, a DC power supply, and a lowlevel control system. The parallel-electrodes are set ina main vacuum chamber, and are connected electronically to a cavity resonator.
The high voltage is in the sinusoidal form with afrequency of 12- 18 MHz. The maximum peak-to-peakvoltage is slightly higher than 100 kV, depending on
the frequency. To generate the voltage, a coaxial cavity resonator with cylindrical shape is adopted. The
structure with a fixed-length cavity and two tuners attached on the sides to change the resonance frequency
enables a shorter cavity length compared with a commonly adopted design with a variable-length cavity.
The cavity is 2250 mm long and 700 mm in diameter,
and the inner shaft with 120 mm in diameter is water cooled and is directly connected to the upper electrode. Each deflector electrode is made of copper, andis 120 mm wide and 700 mm long. The electrode gap isfixed to be 40 mm. The deflector body can be moved
aside from the beam line with the help of a rail stage
when it is not being used. The main amplifier with
20 kW output power is placed beside the cavity anddirectly coupled to the feeder. The total power input
of about 70 k VA and water flow of 55 lit / min are required. The two-dimensional slit system is made of
25-mm-thick copper plates and the slit aperture is remote controlled to within ± 100 mm. The deflector will
be installed between the Q9 lens and the F2 focal planeof RIPS by replacing the switching magnet. The slit
chamber will be placed upstream of the Q10 lens. The
distance between the center of the electrode and theslit is about 1.8 m.
The performance of the deflector is evaluated according to first-order beam optics. It is assumed thatthe beam is focused on the F2 slit in the horizontal
direction and on the new slit in the vertical direction.
In the case of the 54 Ni secondary beam produced from
58Ni with the energy of 57 AMeV, its purity in the total
secondary beam was about 10- 4. With the use of thepresent RF deflector, the purity is expected to increase
by approximately 100 times.
References
1) K. Yamada et al.: RIKEN Accel. Prog. Rep. 34, 201(2001).
2) T. Kubo et al.: Nucl. Instrum. Methods. Phys. Res. B
70, 309 (1992).

top vi e ~si de vi e~"'

rna i n bodyFig. 1. The general plan for RF deflector system.
Department of Physics, Rikkyo University

147

RIKEN Accel. Prog. Rep. 35 (2002)

Liquid hydrogen target for SMART experiments
T. Uesaka,*l K. Suda,*1 M. Hatano,*2 K. Sekiguchi,*2 A. Tamii ,* 2 N. Sakamoto, T. Ohnishi , K. Yako,*2
S. Sakoda,*2 T. Saito,*2 N. Uchigashima,*2 H. Okamura,* 1 and H. Sakai*2
Polarization transfer observables are sensitive to specific spin-dependent transition amplitudes and can bea powerful tool for probing the fundamental interactions relevant to the reaction. This is also the case in
the investigation of three-nucleon (3N) force effects inthe d + p scattering. A theoretical calculation predicts
that the effects of the 3N force, which are by nature
spin dependent, manifest themselves most clearly inpolarization transfer coefficients Kty, K~x' and K~z atbackward angles. 1) We have developed a liquid hydrogen target for the polarization transfer measurement 2)of the d + p elastic scattering at SMART.
An overview of the target system is shown in Fig. 1.
The target volume is 20 mm¢ x 2 mm t and is sealed by
6-j..tm-thick Havar foils on both sides. The target cell is
attached to the second stage (-4 K) of a commercial
refrigerator and is surrounded by a radiation shield.
The radiation shield is mounted on the first stage ofthe refrigerator whose temperature is approximately
50 K. A thin heater inserted between the refrigerator
and the target cell is used to maintain the target temperature at approximately 17 K. A silicon diode sensor
on the target cell continuously monitors the temperature of the target. We employ no feedback system forcontrolling the target temperature since the temperature is found to be stable within the range of ±0.1 K
when extra heat load is absent. The temperature increases by only 0.3 K when a 270 MeV deuteron beamof 50 nA is incident on the target, where the heat load
is -100mW.
Hydrogen gas is fed to the target cell through a reservoir of a 35l volume as shown in Fig. 2. In the courseof a measurement , all the valves A- F are closed andthe inner pressure of the target, being about 1 atm
throughout the measurement , is continuously monitored by a Baratron gauge. To prevent the inner pres-lhiCk4=mm

6!lm
Havar foils
Rerrigerator
Cool Power 4.2LAB

2.8mm

gas feedtarget cellradiation shield

Reservoir
351

Fig. 2. Gas feeding system.

'>

2500

Q)

~

0
..........

....,

(/J

;,::

j \

Liquid H2

~, ..

1000

Carbon

'0

Q)

500

I'l,

,, ,
, .

1500

~

~

CH 2

2000

:J

a

d +p elastic scattering
8 cm =9 0° (8 Iab =43.4°)~"./;!f::'''' \"'"'

o~--~~~~~~~~~

105

110

115

120

125

130

135

E p [MeV]

Fig. 3. Proton energy spectra of the d + p elastic scatteringfrom polyethylene (broken line) and from liquid hydrogen target (solid line). Spectrum for a carbon target(dotted line) under the same experimental conditions is
also shown.

sure of the target from becoming too high, an electric
valve C opens in the case that the readout pressure of
the Baratron gauge exceeds 2 atm.
Figure 3 shows a proton energy spectrum for the d+p
elastic scattering at Ed = 270 Me V and Bern = 90° .
The solid line represents the spectrum obtained withthe liquid hydrogen target. A shoulder at the lower energies is due to deuteron breakup from a hydrogen target. For comparison, spectra obtained with a polyethylene target (broken line) and a carbon target (dotted line) under the same experimental conditions areshown in the figure. With the known cross-section 3 )of the d + p elastic scattering, we obtained the effecti ve thickness of the target to be 2.8 mm (20 mg/ cm 2 ) .
This indicates that the Havar foil on each side swellsby O.4mm.

lOOmrnScatt. Cham.
Fig. !. View of liquid hydrogen target.
*1

*2

148

Saitama University
University of Tokyo

References
1) H. Kamada et al.: personal communications.
2) K. Sekiguchi et al.: RIKEN Accel. Prog. Rep. 35, 44(2002).
3) H. Sakai et al.: Phys . Rev. Lett. 84, 5288 (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Development of polarized proton target for RI beam experimentT. Wakui, M. Hatano,*l H. Sakai,*l T. Uesaka, *2 and A. Tamii*lA polarized solid proton target is being developedfor experiments with RI beams. The target will be
used for the structural study of unstable nuclei throughexperiments involving inverse kinematics. In such experiments, low-energy recoiled protons (typically lessthan 10 MeV) must be detected. A conventional polarized proton target system is not suitable for such
experiments because it requires a high magnetic field(2: 2.5 T) and a very low temperature (:::; 1 K). These
conditions will create difficulties in the detection ofrecoiled protons. Therefore, a polarized proton target that can be operated in a lower magnetic field (:::;
0.3 T) at a higher temperature (2: 77 K) is desirable
for RI beam experiments. The goal of this study is toattain a polarization of more than 60% in a target witha diameter of 20 mm and a thickness of 2 mm.
Protons in a crystal of aromatic molecules such as
naphthalene or p-terphenyl doped with pentacene arepolarized by means of a microwave-induced optical nuclear polarization technique combined with the integrated solid effect (IS E) method. I) In this method,
pentacene molecules are excited to the lowest triplet
state by laser irradiation. A population difference appears in the Zeeman sublevels of the triplet state dueto the angular momentum selection rule; the electronalignment occurs spontaneously. The obtained population difference, 73%, is independent of the magnetic
field strength and the temperature. Then, the population difference is efficiently transferred to proton
polarization even in a magnetic field of 0.3 T by the
ISE method. The polarization procedure is describedin Ref. 2.
The crystals are produced by the Bridgman technique after purification of materials by the zonemelting method. A purification system and a crystallization system were constructed last year. 3 ) A proton
polarizing .system was also assembled and test experiments to polarize protons have been started. 4 )Figure 1 shows a schematic of the proton polarizing system. A target crystal, whose typical size is
4 x 5 x 3 mm 3 , is placed in a microwave cavity mounted
in the center of a C-type magnet. The laser used in thisstudy is a continuous wave Ar+ laser having a maximum power of 5 W. In order to obtain a large population difference in the triplet state, the laser beam ispulsed by an optical chopper and the resulting power
is 40 m W. The pulsed microwave irradiates the target
crystal before pentacene molecules in the triplet state
decay to the ground state. The frequency and powerof the microwave are 9.1 GHz and 2.5 W, respectively.

Chopper(1.............. 0·-I:.,~iiiiljJjji. . . ,. -..

Fig. 1. Schematic of the proton polarizing system. The system consists of a magnet, a laser system for
optical pumping, a microwave system and a magnetic field sweep system for polarization transfer,and a pulsed NMR system for polarization measurement.
*1*2

University of Tokyo
Saitama University149During the microwave irradiation, the magnetic fieldis swept by applying a triangular wave current of 53 A
(peak-to-peak) to a set of coils placed in the microwave
cavity. This current produces the maximum magnetic
field of ±35 Gauss. The proton polarization is measured with a pulsed NMR system, whose frequency is
12.7l\1Hz.
Figure 2 shows a result obtained with a crystal of pterphenyl doped with pentacene in 0.3 T at room temperature. The measured buildup time was 8.2 ± 0.5
minutes, and the extrapolated maximum proton polarization was 0.38 ± 0.02%. The polarization was enhanced by a factor of 4000 compared to that at thermal
equilibrium under the same conditions. The relaxation
time was 17.5 ± 1.3 minutes.
Recently, we have succeeded in polarizing protons up
to 18.4 ± 3.9% in 0.3 T at 100 K. Figures 3 and 4 show
the proton polarization as a function of time in thebuildup and relaxation processes, respectively. The
crystal was naphthalene doped with 0.01 mol% pentacene. The measured buildup time was 1.7±0.2 hours
and the relaxation time was 21 ± 3 hours.
The proton polarization can be improved by using
a higher power laser for the optical pumping. This isbecause a single laser pulse can excite only 0.1 % ofpentacene to the lowest triplet state. Therefore, wewill upgrade the laser to one with a maximum powerof 25 W with which proton polarization higher than

20
,--,

~ 15

c
0

'+=i
CO

N

10

'i:
CO

a. 5

"0

246

8

Time (hour)Fig. 3. Proton polarization as a function of time in thebuildup process in 0.3 T at 100 K. The target crystal isnaphthalene doped with pentacene. The proton polarization is 18.4 ± 3.9%.

1.5
1""""""1~

L.......I

C

0
'.p

1.0

«S

N

"i:
«S

o·

0.5

a.

0.0

0

2

4

6

8

10

Time (hour)

0.5
.....
~

Fig. 4. Proton polarization in the relaxation process in
0.3 T at 100 K. The relaxation time is 21 ± 3 hours.

00.4......

c

0
;;

0.3

N

0.2

co

"~

co

40% is expected.
We are also planning further improvement of the system: an increase of the repetition rate of the laser pulse
and an enlargement of the crystal size.

'0 0.1

Q.

0
0

10

20

30

40

50

Time [min]Fig. 2. Proton polarization as a function of time in thebuildup process in 0.3 T at room temperature. The target crystal is p-terphenyl doped with pentacene. The
buildup time is about 8.2 ± 0.5 minutes and the extrapolated maximum proton polarization is 0.38 ± 0.02%.

150

References
1) A. Henstra et al.: Phys. Lett. A 134 , 134 (1988).
2) M. Hatano et al.: RIKEN Accel. Prog. Rep. 33, 182(2000).
3) M. Hatano et al.: RIKEN Accel. Prog. Rep. 34, 196(2001).
4) T. Wakui et al.: RIKEN Accel. Prog. Rep. 34, 194(2001).

RIKEN Accel. Prog. Rep. 35 (2002)

Continuous spin precession of noble gas nuclei
with active feedback system
A. Yoshimi, K. Asahi, and T. Koike*We report on the study of continuous spin precessionof noble gas nuclei 1,2) where the spin-polarized nuclei
continue to precess beyond their intrinsic transverse
relaxation time with the help of a feedback system.
The aim of this study is to realize a high-precision
measurement of spin precession frequency for fundamental physics experiments. We have constructed theoptical detection system for nuclear spin precession of
129Xe instead of using a pick-up coi1. 2,3) This method
can realize the observation of continuous nuclear spin
precession at a very low spin density « 1 torr) and
low frequencies « 100 Hz), and thus can be applied
to a heavier noble gas Rn and a neutrons, which areimportant for fundamental symmetry studies.
The experimental apparatus is shown in Fig. l.
A sample cell which contains 129Xe gas and a small
amount of Rb vapor is located in a magnetic shield.
129Xe nuclear spins, which are polarized through spin
exchange interaction with optically pumped Rb atoms,
precess around a static field Bo = 28.3 mG (vo =33.5 Hz) produced by a solenoid coil. The nuclear precession at such a low frequency produces a small sinusoidal variation in the transverse polarization of Rb
atoms via the spin exchange. A probe laser beam froma narrow-frequency-bandwidth « 1 nm) diode laser,which has a wavelength of the Rh D1-absorption line
(794.7 nm) and is modulated in circular polarization bya photoelastic modulator (PEM), passes through thecell in the precession plane. Thus the nuclear precession of 129Xe is detected by observing the change in theintensity of the transmitted probe laser beam. In orderto preserve the nuclear precession, a feedback field BFB
is applied to the cell by applying a current into a pair(a)i :.: ~I/"\. /"".•\,. -/1\.\ . P\.
~./:'/0\ /1
V V V V V V V V V-----r-/I\'\.; /f'\.

\,/1\\---'----'.\;

9'(/) -0.1 '--_ _ _ _---'-_ _-'-_ _ _ _ _ _- ' - - _ - - l
3000
3005
3010
3015
3020
3025
3030
Time(s)
(b)

-25

-20

-15

-10

-5

B(deg)

Fig. 2_ (a) Observed continuous precession signal. (b) Observed frequency shift to phase error 8 of feedback signal.

of coils around the cell. The phase and amplitude of
the feedback current are tuned such that the BFB field
is kept perpendicular to the transverse component of
the spin polarization vector. The current fulfilling suchconditions is synthesized from the phase-sensitively detected signal Vs(t) (~0.3 Hz) and the reference signals
for lock-in detection Vrl (t) and Vr2(t) C---33.2 Hz). Thismethod of producing the BFB(t) can considerably decrease ( ....... 10- 3 ) the noise component in the raw signal
Vrw(t) ( . . . . 33.5 Hz).2)
A continuous precession signal was observed after
turning on the feedback system as shown in Fig. 2 (a).
The observed signal Vrnon(t) was phase-sensitively detected by the reference signal of 33.2 Hz and thus had
the frequency of 0.3 Hz. We investigated the responseof the precession frequency to a phase detuning 8 of
BFB using a phase shifter, because the sensitivity ofthe oscillation frequency to 8, if it is high, might be aserious source of error in a high-precision experiment.
As shown in Fig. 2 (b), the frequency shift due to 8 issmaller for longer transverse relaxation time T 2 .
We are currently attempting to use a smaller density
129Xe in this experiment. Thus far we have confirmedthat the 129Xe spins of a 10 torr gas pressure can realize the continuous precession. An improvement in thefrequency stability is also being prepared.
References
1) A. Yoshimi et al. : RIKEN Accel. Prog. Rep. 34, 215

Fig. 1. Experimental apparatus.

(2001) .
2) A. Yoshimi et al.: AlP ConE. Proc. 570, 353 (2001).
3) R. E. Stoner et al.: Phys. Rev. Lett. 77, 3971 (1996).

Tokyo Institute of Technology

151

RIKEN Accel. Prog. Rep . 35 (2002)

Rotating target system for the Big-RIPS separator
A. Yoshida, T. Kubo, Y. Takahashi, and 1. Tanihata
A rotating target system for the projectile fragment
separator (Big-RIPS ) in the RI Beam Factory (RIBF)
has been developed. It was reported 1) that a test experiment was performed using an 40 Ar 9 + beam at 24 A
MeV and 1.9 pJ-LA. Simulation studies were carried out
to explain the data and to estimate the beam spot temperature under future Big-RIPS operating conditions.
A thermal dynamics calculation code, ANSYS(Copyright.c, ANSYS, Inc.), was used for the simulation. A carbon target disk, 2 mm in thickness and
260 mm in diameter and sandwiched by aluminum
cooling plates, which was used in the experimental
setup, was modeled. A schematic view of the disk wasshown in our previous report. 1) Precise meshing was
required around the beam spot because the heat deposited by the beam is very much localized to a circulararea of approximately 3 mm in diameter. A Gaussian
shape beam intensity distribution was assumed at thebeam spot and an energy loss function of 40 Ar beam incarbon material was applied. The boundary temperature for t he cooling water inside the aluminum plate
was fixed at 25°C. A surface emission option was considered for the thermal radiation effect and a measured
emissivity value of 0.84 was used. Nonlinear analysis
was carried out using the temperature-dependent heat
conductivity and specific heat of the materials used. 2)This code can control the rotation of a disk by meansof a mass transport option and a transitional analysis. Because the model size is large and complex, ittakes a few hours of CPU time for one rotation, although we checked that the beam spot temperature
becomes constant after several times of rotation. On
the other hand , if there is no water cooling, the beam
spot temperature does not change considerably but thetemperatures of the other parts increase very slowly toreach a few hundreds °C. This indicates that the watercooling does not affect significantly the beam spot but
affects other parts of the target system and helps thesystem works safely.
The results of the simulation are indicated in Fig. 1.
Because there was an ambiguity for measuring the actual beam spot size in the experiment, a series of calculations were carried out for various spot sizes. The
measured beam spot size was approximately 3 mm indiameter using a ZnS foil. The simulations also supported the same beam spot size. In the low-rotationspeed region, the measured temperature is lower than
the simulated one. This may be because of the position resolution of an infrared radiation t hermoviewer
used for this measurement . Its specific resolution,
0.6 mm/pixel and O.I°C in digital image, was goodenough, but there was a slight vibration observed during the rotation . It was ± 1 mm in the radial direction

152

3000
2800
2600
2400
2200
2000
'0 1800~ 1600~ 1400.... 1200
1000
800
600
400
200
0

~Ar beam expo--~-- sim. <1>1.5II1II- -$_.

in fwhms i m. 4> 3. Omm-),( - sill. 4>6. Onn-<>-U beam sill. 4>1.0111R

0

50

100

150

200

Rotation speed [rpm]Fig. 1. Maximum temperature of the beam spot at various
rotation speeds of the carbon target disk. Experimental
data (thick straight line) and simulation results for various beam spot sizes (dotted lines) are shown for the
40 Ar beam test experiment. The estimation for 238U
beam (thick dotted line) is a lso indicated.

of the target disk, whereas the temperature gradientat 10 rpm near the beam spot was too steep, approximately 25°C/mm. This may cause t he broadening of
the beam spot temperature distribution.
The estimated beam spot temperature under theseverest operating conditions of the future Big-RIPS ,namely, a 238U primary beam at 400 A MeV with
1 pJ-LA intensity onto the carbon target of 5.3 mm thickness , is also indicated in Fig. 1. The assumed beam
spot size of ¢ 1 mm in FWHM and a total heat loss of
22kW give an energy density of 5.1kW/mm 3. A typical simulation result for the rotation speed of 100 rpm
is shown in Fig. 2. The temperature at the beam
spot exceeds 1300°C, whereas that near the aluminum
plates is approximately 150°C, because the cooling water diffuses the heat effectively.
Based on the simulation result shown in Fig. 1, if
the rotation speed is higher than 200 rpm, the beam
spot temperature is maintained sufficiently low compared to the melting point temperature of 3500° C ofcarbon. A rotation faster than 1 krpm is mechanicallypossible; thus , we can make the disk size more compact
while maintaining the velocity of the beam spot in thetangential direction. This is important in the designof the target remote handling system. More simulation studies and R&D experiments are under way to
optimize the disk size and to check the possibilities ofFig. 2. Cross-sectional view of the temperature distribution in the target disk near the 238U beam spot .

using other metal targets such as Be and Ta.
References
1) A. Yoshida et al. : RIKEN Accel. Prog. Rep. 34, 188(2001).

2) National Astronomical Observatory: Chronological Scientific Tables (in Japanese) (Maruzen, Tokyo, 2001);
A Catalogue for Aluminum and Carbon (Ibideu Co.,
Ogaki, 2001).

153

RIKEN Accel. Prog. Rep. 35 (2002)

Performance of a new gas-filled recoil separator GARIS at RILAC
facility measured using 208Pb and 209Bi recoils
K. Morita, K. Morimoto, D. Kaji,* A. Yoneda, Y.-L. Zhao, T. Suda, A. Yoshida, K. Katori, and 1. Tanihata
Last year, we transferred a gas-filled recoil separator (GARIS)l) from the E1-experimental hall of the
RIKEN Ring Cyclotron facility to the experimental
hall of the RILAC facility. 2) The separator was designed for fast (in-flight) and effective collection of nuclear reaction products, separating them from an intense primary beam. The GARIS will be used in the
search for new isotopes of the heaviest elements whose
production cross sections are extremely small.
Along with this relocation, we have made some improvements to the GARIS , as described in Ref. 2.
The original GARIS consisted of three magnets in a
D1-Q1-Q2 configuration, where D denotes the dipole
magnet and Q denotes the quadrupole magnet, as described in Ref. 1. The distance between Q1 and Q2
was 330 mm. This distance has now been increased
to 520 mm. When we designed the Q-magnet , the effect of the large bore radius (150 mm) was not suitably
taken into account. As a consequence, the focusing
power of Q2 was lacking at the highest Bp value of the
D-magnet. By changing only the distance between Ql
and Q2 , the focusing power is expected to be recovered
without changing the power supply to the Q-magnet .
Another improvement was carried out by installinga new D-magnet (D2) between Q2 and the focal plane.
In the experiment , incident beams are stopped by agraphite wall in the Dl-magnet where a large numberof light-charged particles are emitted. Although theB p values of these light-charged particles differ greatly
from the values of the reaction products of interest,
because their source points are not the same as thoseof the reaction products, they reach the focal plane bypassing through the Q-magnets . These light-charged
particles enter the focal plane detectors and create amain background signal in our detection system. The
additional D-magnet sweeps such light-charged particles from the focal point. Thus, we expect to realize a
low background condition at the highest beam intensity.
This year , we performed testing experiments formeasuring the characteristics of the new GARIS sysThe ion-optical acceptance (solid angle) oftem.
the GARIS and transmissions for low-energy stable ions 08 Pb (0.26 MeV/nucleon), 209Bi (0.11 MeV /nucleon)) were measured . Equilibrium charge states ofthese ions in helium gas were deduced. One importantcharacteristic that we wanted to study is background
reduction, in order to determine the effect of the newly
installed D2-magnet. However, the experiment could
not be carried out this year due to a radiation safetyeNiigata University

154

problem that must be resolved as soon as possible.
The ion-optical acceptance of the GARIS was measured using an 241 Am a-source. The source was set atthe target position of the separator. The a -particles
were detected in the focal plane using a position sensitive silicon detector (PSD) whose effective area was
60 mm x 60 mm . The intensity of the source was calibrated separately. A helium buffer gas was not used tofill the chamber in this measurement. The measured
value of the acceptanve was 12.2 msr. The value corresponds to an average angular acceptance of ±62 mrad(±3.6 deg.) . The effect of a change in distance between
Q 1 and Q2 magnets mentioned above on ion optics was
confirmed by this measurement. The system obtained
a double focusing condition in the focal plane at thehighest Bp value of the D1 magnet.
Transmissions of the GARIS for low-energy ions of
208Pb and 209Bi were measured. Target recoils, whichcorrespond to near 180 deg. elastic scattering of the
40 Ar incident beam from the RILAC , were used as lowenergy ions. The target recoils were detected in the
focal plane of the GARIS with the above-mentioned
detector. At the same time, 40 Ar ions elastically scattered by the target were measured by a silicon PIN
photodiode (SSD) set at 45 deg. with respect to thebeam direction in the target chamber. Under thepresent experimental conditions, the interaction energies were well below the Coulomb barriers of the reactions. Therefore, cross sections of both reactions aredescribed purely by Rutherford scatterings for all scattering angles. The change in the Rutherford cross section with a scatter angle near 180 deg. is very small.
For example, the difference between those for 180 deg.
and 170 deg. in the center of mass frame, corresponding
to target recoils for 0 deg. and 5 deg. in the laboratory
frame , is only 1.5%. Thus, we can consider an angular
distribution of the recoil is uniform in our acceptanceangle. From these experimental conditions, the ratioof the number of recoils going into acceptable solid angles of the GARIS to the number of scattered incident
particles detected by the SSD, in the same run is determined only by a geometrical factor. This means thatthe ratio does not depend on beam intensity, target
thickness, or beam energy. Then , we can determine
the absolute transmissions of the GARIS by comparing the number of detected recoils in the focal plane to
the number of scattered 40 Ar in the target chamber inthe same run.
The beam energy from the accelerator was 114 MeV.
A 208Pb metal target material was evaporated on
100 p,g/cm 2 carbon foil. The thickness of the tar-get was 640 J..lg/cm 2 . The target was irradiated fromthe carbon side by the incident beam. The incident beam energy at the half-depth of the target was
109 MeV. In the Bismuth case the metal target material was evaporated on a 3.9 mg/cm 2 aluminum foilthat was used as an energy degrader for an incident
beam as well as a mechanical support. The thicknessof 209Bi target was 300 J..lg/cm 2 . The incident beamenergy at the half-depth of the target was 52 MeV.
The central values of the kinetic energies of the 208Pb
ion and the 209Bi ion just downstream of the targets
were estimated to be 54.5 I\1eV (0.26 MeV/nucleon)and 22 .5 MeV (0.11 MeV/nucleon), respectively. Typical energy spectra measured by the PSD are shown inF ig. 1. The central values of energy in the figure arelower than those mentioned above. The difference is
explained by taking into account the following factors;
the energy loss of the ions in helium gas, that of the
1 J..lm Mylar foil set in front of the detector, and thedetector response for heavy ions. The foil was used forseparating the vacuum region where the detector was
set from the gas region.
The obtained transmissions were 0.85 for 208Pb(0.26 MeV/nucleon) and 0.33 for 209Bi (0.11 MeV /nucleon). Positional distributions of ions detected by
the PSD in the horizontal axis are depicted in Fig. 2
Energy spectra

208Pb recoils

1

20

10

I

30

40

50

Enegy (MeV)

209Bi recoils~g ~8i
15~

10

8 L-A'_t_d_~~~

u

o

10

20

__~~______~
30

40

50

Enegy (M eV)

Fig. 1. Typical energy spectra of ions measured by a PSD
set at the focal plane of GARIS .
Positional Distribution (Horizontal)

1000
800

2.~
of

600

~

1

400

()

by symbols (triangle: 208Pb, square: 209Bi) together
with the result of a simulation, shown by curves. The
PSD is divided into 16 strips in the horizontal axis.
The experimental distribution was obtained by counting the number of ions detected in each strip. Relative
intensities are normalized using the transmissions obtained experimentally as the ratio of the total number of 208Pb detected by the PSD to that of 208Bi
to become 0.85/0.33. The simulation was carried out
assuming that the ions change direction only due toRutherford scattering with helium nuclei of the buffer
gas. The simulation reproduces the relative intensities
as well as the shape of the positional distribution well.
The equilibrium charge states of the ions in heliumgas were deduced from the estimated velocities of theions at the center of the D 1 magnet and magnetic
flux densities of the D1 magnet which gave the maximum yields at the detector. The deduced values are
8.3 for 208Pb of 0.26 MeV/nucleon and 5.4 for 209Bi of
0.11 MeV/nucleon. The values agree with those calculated using an empirical formula given by Ghiorso etal. 3 ) with 10% accuracy. Knowledge of this quantity
is important for setting the apprppriate magnetic fieldstrength of the magnets, particularly for experiments
involving a search for unknown elements. We will continue measurements of the equilibrium charge states inhelium gas for heavier ions using known fusion evaporation reactions next year in order to make a precise
extrapolation of them possible for the heaviest system.
We can estimate a possible event rate for an experiment searching for a new element, for example nucleus 278[113] of the 113th element which is expected
to be produced via 209Bie OZn,n) reaction, using thenumbers obtained in the present results. 3 x 10- 37(0.3 pbarn) as an expected production cross section,
3 x 10 13 /S (5 particle - J..lA) as a beam intensity,
6 x 10 17 /cm 2 (200 J..lg/cm 2 ) as a target thickness, and0.37 as an overall efficiency estimated by the simulation. Using these numbers we obtain an event rate of
2.0 x 10- 6 /s = 1.2/week. This event rate shows thatthe experiment is feasible.
In the next experimental period (from January to
March 2002) , experiments to measure the equilibrium
charge states in helium gas for the 100th (Fm) and102nd (No) elements are scheduled.
We will continue measurements of the quantities for
greater atomic numbers up to 112 in 2002. We foresee
starting the experiments regarding the search for a newelement at the end of 2002.

200

0
-150

-100

-50

50

100

150

Position / mm

Fig. 2. Positional distribution of ions in the horizontal axis
at the focal plane of the GARIS. Experimental ones areshown in symbols: triangle 208Pb (0.26 MeV/nucleon),square 209Bi (0.11 MeV/nucleon). Curves are those produced by simulation.

References
1) K. Morita et al.: Nucl. lnstrum. Methods Phys. Res. B
70 , 220 (1992).
2) K. Morita et al.: RIKEN Accel. Prog. Rep. 34, 184(2001).
3) A. Ghiorso et al.: Nucl. lnstrum. Methods Phys. Res.
A 269, 192 (1996).

155

RIKEN Accel. Prog. Rep . 35 (2002)

Installation of a high-resolution magnetic spectrograph PA
N. Yamazaki ,* T. Teranishi,* s. Michimasa,* Y. Mizoi, M. Notani ,* Y. Ohshiro,* s. Shimoura,*
K. Ue,* s. Watanabe,* Y. Yanagisawa, and S. Kubono*
A high-resolution magnetic spectrograph, called PA,
has been installed as one of the CNS major facilities in the E2 experimental hall at the RIKEN Accelerator Research Facility. It was originally designed
and constructed at the Institute for Nuclear Study at
the Tanashi Campus of the University of Tokyo.l) It
was frequently used for high-precision spectroscopic
measurements of nuclear structures and nuclear astrophysics studies, and it will now be used primarily forhigh resolution spectroscopy at low energies.
F igure 1 shows a plane view of the P A spectrograph.
The spectrograph has the following features . It has a
QDD configuration, and has double focusing at the focal plane. Although it has a high resolving power, it isvery convenient to use; the DC current is provided in aseries for D1 and D2 , and the Q-magnet current is set
automatically following the current for the Dipole magnets. A spectrum at the focal plane can be obtained
simply by moving the focal plane detector, since the focal plane position depends on the reaction kinematics.
The specifications of the spectrograph are summarizedin Table 1.
When the spectrograph was transferred from
Tanashi to RIKEN, several modifications were applied
to the system as follows:(1) The platform at the focal plane area was rebuilt
to extend the area with a high rigidity for future development of the detector system.
(2) The gate valve at the entrance of the spectrograph was renewed.
(3) The entire controls system has been renewed using a sequencer and touch panels, which controls thetarget and the turn-table in the scattering chamber,Table 1. Specifications of PA.
Dispersion
Magnification:
Horizontal
VerticalOrbit radius
Maximum energy
Angular range
Momentum resolution
Energy range
Maximum solid angle:
Focal plane:
LengthTilted angle
Radius of curvature
Maximum field strength:
Dipole magnet
Quadrupole magnet
Total weight

2.79
-0.37

4.44
130-150cm
150 Q2/A MeV-20 - +1 36deg.
1/10000
30%

6.4msr100cm
55 deg.
600cm
11.9 kG
0.896kG/cm
55 t

the spectrograph angle, and the focal plane positioning. It also controls the vacuum system, including
the section of the beam line just before the scattering chamber.
(4) All of the control systems of the DC power supplies were renewed as they were too old and had someinstability. The oil condenser was also changed to a
dry condenser for safety reasons.
(5) The maximum angle available for measurements
is now limited to about 136 degrees, by the new triplet
Q magnets on the beaII?- line.
The setting precision was measured before moving
the spectrograph from the Tanashi Campus. Some parameters, particularly around the taget chamber, were
misaligned by nearly 2 mm. This problem was considered to come partly from a structural weakness at
the central target region , because the scattering chamber was sitting on a structure to avoid the water pipes
for the magnets. This problem has been rectified bychanging the water pipe system. All of the alignments
have been made with precision of 0.2 mm.
The spectrograph will be ready for experiments inthe spring of 2002. The focal plane detectors available
are explained in Refs. 2 and 3.
References

Fig. 1. Plane view of the high-resolution magnetic spectrograph PA.
Center for Nuclear Study, University of Tokyo

156

1) S. Kato , M. H. Tanaka, and T. Hasegawa: Nucl. Instrum. Methods 154, 19 (1978).
2) M. H. Tanaka, S. Kubono, and S. Kato: Nuel. Instrum.
Methods 195, 509 (1982).
3) X. Liu et al.: Nucl. Phys. A 432 , 66 (1999).

RIKEN Accel. Prog. Rep . 35 (2002)

Development of a multiple-reflection TOF mass spectrometer
Y. Ishida, M. Wada, Y. Matsuo, 1. Tanihata, A. Casares,* and H. Wollnik*
The masses of stable and long-lived nuclei are knownwith good accuracy, while information is scarce in theregions far from ,8-stability. However , particularly themasses of nuclei in such regions are interesting because
they play an important role in astrophysical processes,
and because the predictions of various mass models
differ from each other greatly.
We plan to measure the masses of very short-lived
nuclei far from stability using a multiple-reflection
time-of-flight mass spectrometer (MR-TOF). Via projectile fragmentation , a large variety of exotic nuclei
can be produced and separated in flight by the RIKEN
projectile fragment separator (RIPS) or Big RIPS in
the RIKEN RI-Beam Factory project. Subsequently,
energetic ions are injected into an RF ion-guide system,1) and thermalized in it. The ions are extracted
from this system and guided to the MR-TO F for mass
spectrometry.
If the width of the flight-time distribution cannot
be reduced, one must increase the overall flight time inorder to increase the mass-resolving power of a time-offlight mass spectrometer. To achieve such an increased
flight time, ions are repeatedly reflected between two
pulsed grid-free ion mirrors. In such a system the mass
resolving power m/ ~m is expected to increase linearlywith the number of reflections.
The MR-TOF has been built as a coaxial systemwith two pulsed grid-free ion mirrors. The main bodyof the MR-TOF is shown in Fig. 1. The total length isabout 40 cm. There are 15 gold-coated aluminum ringelectrodes inside a plastic tube. These electrodes act
as two ion mirrors and two einzel lenses. We coaxiallyplaced an electron impact ion source on one side andmicro channel plates on another side for an off-line test.
The ions produced in the ion source are accelerated toan energy of 1.5keV, and extracted into the MR-TOF
at 1 kHz repetition frequency. With switching the electric voltages of the ion mirrors on and off, the ions canmove back and forth between the ion mirrors repeatedly. The more energetic ions penetrate deeper into therepeller fields of the ion mirrors , thus the system canbecome energy-isochronous, that is, the flight times ofions do not depend on the ion energies although theyvary with the ion masses. 2 ) The system can operate ina low-resolution linear mode, i. e., without reflections.
In this case, a complete mass spectrum is recorded. To
achieve a higher mass-resolving power, the MR-TOF
can be operated in the multiple-reflection mode. Evenin this mode, the measuring time is less than 1 ms.
This means that the MR-TOF can be applied to very
short-lived nuclei.
Oak Ridge National Laboratory, USA

Fig.!. Main body of the MR-TOF. Inside a plastic tube
there are 15 gold-coated aluminum ring-electrodes as
ion mirrors and lenses .

600

(a)

8"Kr

Number of Reflections = I
Resolving Power = 555

500

400

.~ 300
c<J.)

E 200
100
7~

0
5000

6000

Time of Flight (ns)25

Number of Reflections = 15
Resolving Power = 4956

(b)

20

.c 15

·Cil

c<J.)

E 10

103000104000105000106000Time of Flight (ns)Fig. 2. Measured mass spectra of the krypton isotopes withnatural abundance (a) in the linear mode and (b) after 15 reflections. Peaks of the isotopes are labeledwith isotopic symbols. The mass-resolving powers ofm/ i::l.m ~ 555 and 4956 are achieved for the linear and
15-reflection modes, respectively.

In the linear mode , without reflections, the mass
spectrum for the krypton isotopes with natural abundance is shown in Fig. 2 (a). The flight-time difference

157

5000

4000

....
Q)
~

d: 3000
be
.s:c:
]

2000

Q)

e:::

•

1000

0
0

10

12

14

16

Number of Reflections

Fig. 3. Mass-resolving power as a function of the numberof reflections.

between 83Kr and 84Kr and the FWHM of the peakare 86 ns and 13 ns, respectively. We have achieved
a base resolving power of m/ tlm ~ 555. Using themulti-reflection mode after 15 reflections, the flighttime difference increases to 649 ns, while the FWHM
is as narrow as in the linear mode. As seen in Fig. 2 (b),the mass-resolving power of m/ tlm ~ 4956 has beenachieved.
Figure 3 indicates that the mass-resolving power in-158

creases almost linearly with the number of reflections.
In other words, the MR-TOF satisfies the energyisochronous conditions for any number of reflections
chosen, thus the increase of the mass-resolving power
depends only on the overall flight time of the ions.
The results are consistent with those obtained at
the Max-Planck Institute for space applications. 3) It
is possible to make the mass resolving power increase
up to 2 X 10 4 with more than 100 reflections. In orderto reach a higher resolution , it is necessary to elongate
the MR-TOF because the resolving power of the MRTOF is mainly limited by the stability of the power
supply for the electrodes. 4) For on-line measurements
using RIPS or Big RIPS , an ion-bunching device tooperate between an RF ion-guide system and the MRTOF must be developed.
References
1) M. Wada et al.: RIKEN Accel. Prog. Rep. 34, 202(2001).
2) H. Wollnik and M. Przewloka: Int. J. Mass Spectrom.
Ion Processes 96, 267 (1990) .
3) A. Casares et al.: Proc. 48th ASMS Conf. on Mass Spectrometry, Long Beach, USA, (2000) p. WPA010.
4) A . Casares, A. Kholomeev , and H. Wollnik: Int. J. Mass
Spectrom. 206 , 267 (2001).

RIKEN Accel. Prog. Rep. 35 (2002)

Improving neutron detection efficiency by using passive converters
T. Baumann,*l H. Ikeda, M. Kurokawa,*2 M. Miura,*2 T. Nakamura,*2 Y. Nishi, S. Nishimura, A. Ozawa,T. Sugimoto,*2 1. Tanihata, and M. Thoennessen*lRare isotope beam facilities that use projectile fragmentation and in-flight separation to produce neutronrich nuclei require neutron detection systems with ahigh detection efficiency at energies of approximately
50 to 400 Me V for the measurement of neutrons frombreakup reactions. Although liquid or plastic scintillators are usually well suited for large-area detectors,
the interaction length of neutrons in these materials requires a large detector volume in order to achieve highdetection efficiencies. A possible means to boost neutron detection efficiency, particularly for higher neutron energies, is to use passive converter materials thathave a much shorter interaction length for neutrons.
Here we report on measurements of relative detection efficiencies for a combination of iron converter andplastic scintillator compared to those for a pure plastic scintillator detector for neutrons of 20- 140 MeV.
The experiment was performed at the RIKEN Accelerator Research Facility. Elements of the NEUT neutron detector array (see, e.g., Ref. 1) were used for thismeasurement. Neutrons of a broad energy range were
produced using a 100 MeV jnucleon beam of 13C fromthe RIKEN Ring Cyclotron impinging on a 2-cm-thickaluminum target. The primary beam was stopped in
the target , so that only lighter fragments and neutrons
could reach the detector setup. A thin plastic startdetector was placed 10 cm in front of the production
target, while the neutron detectors were mounted at a
distance of about 5 m behind the target.
The neutron detector setup consisted of two sets
which were placed symmetrically with respect to thebeam axis. This assured the same neutron flux throughboth detector sets. Each set contained 3 blocks of
6 x 6 x 108 cm 3 BC-408 plastic scintillators stacked
vertically. The front of each set was covered by plastic
veto detectors of 5 mm thickness in order to discriminate charged reaction products. Iron converters of 2 cm
and 3 cm thickness were added to one of the two detector sets , enabling a direct comparison of the numberof detected neutrons in each of the two detector sets.
The iron converter was placed between the veto detectors and the neutron detectors. In order to account for
the asymmetries of the setup, a measurement without
an iron converter was also performed. Separation of
beam-related gamma rays and neutrons was achievedby time-of-flight measurement.
The results of these measurements are presented as
detection efficiency ratios dependent on neutron en*1

*2

1.2

(a)

....=8=.....=+=~-~~--------------~•£, with 3 em convertero £, with 2 em converter

0.8

1.2

(b)

~=i=

----------~~--------

~­
~~-

0.8

20

40

60

100
80
En (MeV)120

140

Fig. 1. Measured efficiency ratios. Open symbols correspond to the 2 em, solid symbols to the 3 em converter.
Results for a 2 MeVee (a) and a 5 MeVee (electron equivalent) cutoff threshold (b) are plotted.

ergy. The efficiency ratios were calculated by dividing
the number of neutrons per energy bin that were detected with the converter-equipped detector set by the
number of neutrons that the pure plastic scintillator
detected. Accordingly, an efficiency ratio above one
would indicate an enhancement of the detection efficiency by the passive converter. Figure 1 shows theresults for two different cutoff thresholds that were applied to data from the same measurement.
This measurement corroborates our results fromsimulations showing that passive iron converters canbe effectively used to enhance the neutron detection
efficiency at energies below 200 MeV. We found experimental evidence for a 10- 20% increase in detection efficiency at neutron energies between 100 and 140 MeV
for the combination of a 2 cm or 3 cm iron converter
and a 6 cm plastic scintillator. A more detailed discussion can be found in Ref. 2.
This work was supported by the U. S. National Science Foundation under grant PHY 95-28844.
References
1) T. Nakamura et al.: Phys. Lett. B 331, 296 (1994).
2) T. Baumann et al.: accepted for Nuel. lnstrum. Methods Phys. Res. B (2002).

National Superconciucting Cyclotron Laboratory, Michigan
State University, USA
Tokyo Institute of Technology

159

RIKEN Accel. Prog. Rep. 35 (2002)

High-efficiency positron moderator
using electropolished tungsten meshes
F. Saito, Y. Nagashima,*l L. Wei ,*2 Y. Itoh,*3 A. Goto, and T. Hyodo*lA high moderation efficiency and long-term stabilityof positron moderators have been important factors
in the development of variable energy positron beams.
The moderation efficiency is defined as the ratio of thenumber of extracted slow positrons to the number of
positrons emitted in the radioactive source per unit
time .
Recently, we reported that a six-overlapping tungsten mesh moderator has a high moderation efficiency. 1 ,2) Since the meshes have a large surface area
for the volume , high efficiency is expected when they
overlap. By reducing the diameter of the wires in themeshes , it is thought that even greater moderation efficiencies may be obtained for an optimal combinationof meshes.
In the present paper , we report high-efficiency
positron moderators with stacks of electropolishedtungsten meshes.
The meshes, as received, originally exhibited 85%
transmission with 20 {Lm wires. They were held in an
acrylic frame , 20 mm x 20 mm in size , and electropolished in NaOH solution of 0.5 N at room temperature.
First, a current of 500 rnA was passed for 60 s then
100 rnA for 15 s, and 50 rnA for 5 s. Through th'is pro~cess, the wires of the meshes were thinned to a diameter of about 10 {Lm.
The meshes were cut into rectangles, 7 mm x 18 mm
in size, and then annealed in vacuum (~6 x 10- 7torr) by passing an electric current through tungsten
foils enclosing them. The temperature was raised andmaintained at 2000°C for 2 min. After annealing, themeshes were quickly transported in air and installed in
the moderator assembly of the beam apparatus.
The moderator was placed 1 mm away from the window of a 22Na positron source of activity 1.38 x 108 Bq(3.73mCi). The moderator was held at an electrostatic
potential of +350 V with respect to the chamber walls
and 9 V below the source potential.
The experimental system used to measure the efficiency of the moderator was a magnetically guided
positron beam system with a trochoidal E x B filter.
The beam intensity was measured by counting 511 keY,),-rays using a high-purity Ge detector.
The beam intensities for 6 to 24 overlapping meshmoderators are shown in Fig. 1. The moderation efficiencies determined from the beam intensities are also
shown in Fig. 1.
Although the efficiency is expected to increase with
*1
*2

*3

160

University of Tokyo
Institute of High Energy Physics , China
Advanced Research Institute for Science and Engineering

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Fig. 1. Slow positron beam intensity plotted versus numberof overlapping tungsten meshes of the moderators. The
activity of the 22Na source is 1.38 x 10 8 Bq (3.73mCi).
The scale on the right side indicates the moderation
efficiency.

the number of overlapping meshes, the value is saturated when the number of the meshes exceeds 12.
This is probably due to the increase in the fraction of
the slow positrons trapped by the wire surfaces of themeshes.
The highest value of moderation efficiency is 7.5 x
10- 4 for 12 overlapping meshes . This value is higher
than that of the tungsten mesh moderator with 20 {Lmwires reported previously.l ,2) This value is also higher
than that obtained using a transmission moderator
with a tungsten single-crystal foil. 3) Although thevalue is lower than that of solid rare-gas moderators,4- 6) the tungsten mesh moderator has the following advantages: the treatment is easier, the cost islower, and the long-term stability is higher.
We thank the members of the Division of ResearchInstruments Development at RIKEN , in particular, S.
Nioka for expert technical assistance.
References
1) Y. Nagashima et al.: Jpn. J. Appl. Phys. 39, 5356
(2000) .

2) Y. Nagashima et al.: RIKEN Accel. Prog. Rep. 34, 115(2001).

3) E. Gramsch et al.: Appl. Phys. Lett. 51, 1862 (1987).
4) A. P . Mills, Jr. et al.: Appl. Phys. Lett. 49, 1121 (1986).
5) R. G. Greaves et al.: Can. J. Phys . 74, 445 (1996).
6) N. Oshima et al.: RIKEN Accel. Prog. Rep. 34, 114(2001).

RIKEN Accel. Prog. Rep. 35 (2002)

Development of a time-of-flight detector with streak camera II
K. Morimoto , T. Ohnishi, F. Tokanai,* and 1. Tanihata
The high-resolution time-of-flight (ToF) detector using a streak camera is under development for the highresolution particle identification system.1 ,2) It is expected to be useful for experiments using high-energy
radio isotope (RI) beams at the RI Beam Factory.
The configuration of this ToF detector is shown in
Fig. 1. This detector consists of two identical sets ofstreak cameras. These systems are tilted at 45 degrees with respect to the beam path. A thin target foil
is mounted at the center of each system to emit secondary electrons. A 300-A-thick Au layer evaporated
on both sides of a 1.5-fLm-thick mylar foil is used forthe target. Acceleration meshes are mounted on bothsides of the foil at a distance of 2.7 mm. At the streakimage detector part, the secondary electrons from themeshes are accelerated by the electric field and focusedby an electric lens. These electrons are swept by applying a 100 MHz sine wave voltage to the vertical andhorizontal diffraction plates. These swept electrons
impinge on a position-sensitive detector. In constant,at the center-image detector part, the secondary electrons are also accelerated, focused by an electric lens,and directly impinge on the position-sensitive detector. In a previous system, a phosphor screen (P-43)
and an image intensifier (II) with CCD were used forthe position-sensitive detectors. In order to improvethe event acquisition rate, the II with CCD as replacedwith a MCP with a Wedge-and-Strip anode detector
that has a capability of 20 kHz event rate and 50 fLm
Streak Image
Detector

FWHM of position resolution.
The performance test of the system was carried out
using 20Ne beams of 135 A MeV energy at the RIKEN
Ring Cyclotron E1 beam course. In this experiment,
the basic operation of the system was investigated; forexample phase-lock of sweeping electric fields between
systems 1 and 2, in particular detection efficiency wasmeasured. The test revealed that the detection efficiency was about 50% at each MCP with the Wedgeand-Strip assembly compared with the trigger signal
made by a plastic scintillator installed immediately after the streak ToF detector. This low detection efficiency was due to low secondary electron emission fromthe thin foil with evaporated Au. Although the detection efficiency was measured with a target foil evaporated with AI, the detection efficiency was almost thesame as that of an Au target. In order to improve thedetection efficiency, we are preparing a target that is
evaporated with Cs1. It is expected to increase thenumber of second electron emissions. 3 )References
1) F. Tokanai et al.: IEEE Trans. Nucl. Sci. 47, 1753
(2000).

2) F. Tokanai et al.: RIKEN Accel. Prog. Rep. 33 , 159(2000).

3) H. L. Seifert et al: Nucl. Instrum. Methods Phys. Res.
A 292, 533 (1990).

RF Signal Supply(I00MHz)M

Streak Camera
system 1
RI(Heavy Ion)
1.5mm Mylar+ 300 A Gold(Both Sidc)
6mm Cuppcr Mesh
(Opcn fraction 50%)

Fig. 1. Schematic of the ToF detector system.

Yamagata University

161

RIKEN Accel. Prog. Rep. 35 (2002)

Study of scintillator radiation hardness
S. Nishimura, M. Kurata-Nishimura, K . Morimoto, Y. Nishi, and 1. Tanihata
The RI beam factory (RIBF) ,l) which is under theconstruction at RIKEN, has the capability to explore
new isotopes for the astrophysics r-process as well as
detailed studies of nuclear structures, a skin and a halo.
Its maximum accelerator performance can be achievedby using a high-resolution time-of-flight (TOF) detector with a timing resolution of below 30 ps to separate the produced secondary nuclei, particularly forthe heavy-mass region above 130 a.u. We have reported an ultrahigh-resolution TOF scintillation detector with a timing resolution below 10 ps by optimizing
the detectors. 2 ) Our studies suggest the importance ofa larger number of photoelectrons for high-resolution
TOF scintillation detectors . It is known that a reduction of scintillation light is expected after irradiation of
charged particles. 3 ,4) Reduction of the number of photoelectron caused by such radiation damage is a criticalissue in relation to timing resolution. In this report,
we focuse on the timing resolution of an ultrafast scintillation detector as a function of the total radiationdose in order to evaluate the radiation resistance ofthe heavy-ion beam.
The test experiment was performed in the E 1b beamline at the RIKEN Ring Cyclotron (RRC) , where theprimary beam of 40 Ar was extracted at an energy of
95 MeV per nucleon. Figure 1 shows a schematic of
our experimental setup. Two identical scintillation detectors (SO and Sl) were installed in the beam line.
Each scintillation detector consists of a piece of plastic
scintillator (Bicron BC422Q) and two identical PMTs
(Hamamatsu R2083). The scintillators were wrappedwith aluminum foil , so that the light was transmitted mainly by total internal reflection. For the operation of the scintillation detector with high beam in-

c:

:c
_

tensity, we have added booster HVs to the last threedynodes of the PMTs to supply sufficient current in
the tubes. The current of the last dynode of PMT increased up to 2.5 rnA at the beam intensity of 3 x 10 6 .
The integrated number of counts on detector SO wasrecorded by a scaler. The ratio of double-beam events
to one-beam events in one RF cycle is estimated to be
below 10% under the high-beam-intensity condition.
The size of the beam spot on the scintillator was estimated to be less than 4 x 2 mm 2 . Strong reductionof pulse heights for both scintillation detectors was observed as the total dose increased. After a total hitsof 1.03 x 10 11 , the pulse height was reduced by a factor of 1/5. Figure 2 (a) shows the time-of-flight (TOF)
spectrum under the primary condition. Because detectors SO and Sl are identical, the intrinsic timing

40Ar

SO

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Fig. 1. Experimental setup for study of radiation hardnessof scintillation detector.

(a)

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TIwindow

Vacuum500

Time-ot-Flight

10 00

1500

(ps)

-1000

- 500

500

Time-ot-Flight

1000

1500

(ps)

Fig. 2. Time-of-flight (TOF) spectra between 80 and 81 (a) before and (b) after the radiation dose.

162

resolution was extracted by assuming equivalent timing resolutions . As previously reported,2) the intrinsic
timing resolution for the nonirradiated detector was
estimated to be 13 ps. Figure 2 (b) shows the TOF
spectrum after the radiation damage. The broadening of the TOF spectrum is observed with radiation
damage, where the intrinsic timing resolution was approximately 38 ps. An additional improvement in timing resolution is expected with the pulse height cor-~oo~------~------~------~----~------,

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rection, together with the position correction using an
additional position sensitive detector near the scintillation detector. In order to investigate the characteristics of the scintillator itself, the wavelength of scintillation light was measured using a monochromatic
illuminator. The results of the emission spectra fornonirradiated and irradiated scintillators are presented
in Fig. 3. The results show a greater decrease of emission intensity in the black region relative to the longer
wavelength as was observed. 3 ,4)We have observed the reduction of pulse height aswell as a wider TOF spectrum after the irradiation
with the heavy-ion beam. The poorer timing resolution after radiation damage can be explained by the
reduction of pulse height based on the statistical explanation of the number of photoelectrons. 5 ).!.

S 1500...................;..................n..... u.;.... u......................

'iij
CIJ

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o 350

400

450

500

Wavelength

550

600

(nm)

Fig. 3. Emission spectra for nonirradiated and irradiatedscintillators.

References
1) I. Tanihata: J. Phys. G: Nucl. Part. Phys. 24, 1311
(1998).
2) S. Nishimura et al.: RlKEN Accel. Prog. Rep. 34, 209(2001).
3) S. Majewski et al. : Nucl. lnstum. Methods Phys. Res.
A 281, 500 (1989).
4) M. M. Hamada et al.: Nucl. lnstrum. Methods Phys.
Res. A 422, 148 (1999).
5) M. Kurata et al.: Nucl. lnstrum. Methods Phys. Res. A
349 , 447 (1994).

163

RIKEN Accel. Prog. Rep . 35 (2002)

Development of fast timing beam line scintillator
for RIPS with PMTs operated in vacuum
R. Kanungo, 1. Tanihata, M . Chiba, and T . Suda
The present day focus of nuclear physics experiments
is concentrated primarily on studies involving unstable
nuclei. These nuclei are produced as secondary beams.
The technique for such production at RIKEN is project ile fragmentation which introduces a large momentum
spread in the secondary beams. It is t herefore, essent ial to be able to measure the momentum of these secondary beams with high precision in order to perform
further experiments with them.
The plastic scintillator detector is one of the simplest devices which can be used for moment um measurement using the t ime-of-flight (TO F) between two
such detectors. The RIKEN Projectile fragment separator (RIPS ) beam line scintillator detectors have atime resolution ~ 100- 200 ps. This requires upgradingfor high-precision experiments. During the last two
years we have constructed ultra-fast timing scintillator detectors, with the t ime resolution of 30 ps (with40 Ar beam), to meet this requirement, and they havebeen used for several experiments at RIPS.
The scintillators are large in size (70 mm x 70 mm
and 150 mm x 100 mm) to meet secondary beam requirements and are coupled to Hamamatsu 1 inch photomultiplier tube (PMT) with the help of a light guide.
The scintillator was in vacuum while the PMT had tobe operated in air. The light guide was thus used tobreak the vacuum. This makes the installation of suchdetectors quite cumbersome.
It was thus important to develop a compact detector
with the PMT being operated in vacuum. In addition
to solving the problem of the installation of such detectors, it is neccessary to have such an arrangement
in order to directly couple the scintillator to t he PMT
without any light guide. Such coupling is found toyield a better time resolution.
The primary problem associated with operating the
hybrid PMT assembly, designed by Hamamatsu, invacuum was the outgassing from the PMT. To avoid
this we used the Hamamatsu R4998 PMT and design'ed and prepared the booster circuit and its coupling to the PMT in such a way as to make it suitablefor use in vacuum. The booster circuit designed is also
expected to have a high rate stability, ~ 10 7 cps, however, at present we have only made a preliminary test
up to 10 4 cps.
We used a 70 mm x 70 mm scintillator coupled tothe prepared PMTs at both ends with a light guide,
and the entire assembly was put in vacuum. In order
to compare its timing performance with our previously
used hybrid PMT assembly, we coupled same PMTs,

164

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1500

1600 1700 1800 1900 2000
High voltage of F1 piaL and F2plaL

2100

Fig. 1. Intrinsic time resolution comparison of PMT developed for use in vacuum and PMT used in air , (a) as afunction of counting rate, and (b) as a function of PMThigh voltage.

but booster designed by Hamamatsu, with the same
size scintillator and operated it in air.
The test was performed at the E1c beam line of RRC
using a 70 A MeV 18 0 beam. The detector could be
successfully operated in vacuum ~ 10- 6 torr for a period of 24 hours. No change of the vacuum condit ionor fluctuation of the pulse height of the detector wasobserved. The results of a comparison between the
intrinsic time resolution of the newly fabricated detector operated in vacumm and the one operated in air
are shown in Fig. 1. The time resolution of the newly
fabricated detector appears to be marginally improved
compared to the usual one.
Since the succesful test of this detector , we have fabricated similar scintillator detectors for use at RIBLL ,Lanzhou, China for RIKEN-China collaboration experiments. This detector is expected to be very usefulfor the future RI Beam factory where we may expect toachieve much better time resolution using scintillators
directly coupled to PMT.

RIKEN Accel. Prog. Rep. 35 (2002)

Development of plastic scintillators as possible energy detectors
for proton scattering at RIBF
R. Kanungo, H. Sakaguchi,* 1. Tanihata, T. Onishi, T. Suda, H. Takeda,*
T. Murakami,* S. Ota,* and S. Terashima*Proton scattering at intermediate energies at the RI
Beam Factory, RIKEN requires the development ofhigh-energy-resolution detectors. NaI(TI) satisfies thisrequired criteria. However, it has some inconveniences,some of the primary ones are as follows:(1) Due to its extremely hygroscopic nature it becomes difficult to store the crystal, particularly
very large crystals, for a long period of time andretaining its original performance.
(2) The temperature of the crystal must be maintained at a constant level during very long experiments.
(3) The reaction of protons in NaI(TI) decreases detection efficiency and introduces complexities inanalysis.
(4) Extremely large crystals are quite expensive.
To overcome or minimize some of these difficulties
we considered an alternative method of energy measurement of the recoil protons. This method is basedon the time of flight between two plastic scintillators.
To test its feasibility, we performed a very preliminary
test experiment using a 12 MeV primary beam of protons available from the tandem accelerator, at Kyoto
University. After scattering on a Au target the beam
was incident on the scintillator detectors.
The first test had two primary objectives:
1. To determine the best time resolution we can obtainwith low-energy protons.
2. To observe the effect of using a light guide on time
resolution with large scintillators.
To achieve objective 1, we used small scintillators
20 mm wide and 70 mm long which were directly coupled to the photomultiplier tubes (PMT), with a photocathode 20 mm in diameter. Two PMTs were coupled on two sides of the scintillator. Two types of scintillator materials with thicknesses of, 2 mm (small sc-l)
and 3 mm (small sc-2) were used. The protons were
stopped in these detectors. The intrinsic time resolution of such a detector can be estimated from a Gaussian fit to the time difference between the left and theright PMTs after correction for position dependence,i.e., intrinsic time resolution = (7 (TI-Tr)/sqrt(2).
In a simple estimate, if we have two identical detectors and assume that each PMT used has the sametime resolution, then it can be easily shown that the
time-of-flight (TOF) resolution between such detectors
is equal to the intrinsic time resolution of each detector. Since the time difference between the two ends of
Graduate School of Physics, Kyoto University

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Fig. 1. Intrinsic time resolution of PMT directly coupled
to small scintillator.

a scintillator is strongly dependent on the position of
the incident particle, we need to correct for the position dependence in order to obtain the true time resolution. In the absence of position-sensitive detectors
for the present test , we collimated the incident protons
using a 6-mm-diameter circular collimator and also a2-mm-diameter one. The latter was found to improve
the time resolution more than the former. The estimated position resolution from the present data is
about 1.24 mm in sigma. There is a small differencein time resolution between the two different types ofscintillator materials tested and the small sc-2 type appears to be better (Fig. 1). The results show that an
intrinsic time resolution of 18 ps can be achieved withthe use of this scintillator. With a flight path of 1.6 m
the energy resolution of full-width at half maximum(FWHM) is 62 ke V fOL2D MeV protons and 1.06 MeV
for 120 MeV protons.
We also used large scintillators (70 x 70 mm) coupled
to the PMT by twisted a light guide for achieveing
objective 2 of our test. Figure 2 shows the intrinsic
time resolution obtained with such scintillators which
is clearly worse than the ones without a light guide.
In conclusion , the results of the time resolution ofplastic scintillator detectors with 12 MeV proton beamshows extremely good timing response for small-width
scintillators coupled directly to the PMT, down to18 ps in sigma. Translating this to proton energy res-165

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scintillator by a light guide.

166

olution, 62keV in FWHM with 20MeV protons canbe expected given a flight path of 1.6 m. This resolution is much better than that of NaI(TI), 280keV,
FWHM. However, NaI(TI) yields a better result at
higher proton energies such as 680 ke V (FWHM) for
120 MeV protons as compared to 1.02 MeV (FWHM)
as estimated from TOF.
Additional tests with longer and wider scintillators
coupled to wider PMTs, are being planned in order toascertain finally the feasibility of usng this detector for
proton energy measurement.

RIKEN Accel. Prog. Rep. 35 (2002)

Development of segmented Ge array
M. Kurokawa,*l S. Shimoura,*l H. Iwasaki,*l H. Murakami,*2 and H. Sakai*l
An array of Ge detectors is being developed at CNS
for the detection of '"Y rays emitted from fast recoiling
nuclei ((3 = 0.3 - 0.5). To perform accurate correction of the energy for such Doppler-shifted '"Y rays, theemitted polar angle must be measured as accurately as
possible using position sensitivity of the detector.
In the array, a ninefold-segmented Ge detector as
shown in Fig. 1 will be employed for this purpose.
The detector manufactured by Eurisys Mesures has aplanar-type structure and is cylindrical with a diameter of 3.5 cm for the crystal itself and 3.0 cm for theeffective area, in which a parallel electric field along
the depth of the detector is expected. The thicknessof the detector is 2.0 cm. The size of a segment isdetermined by the absorption length of 1 Me V '"Y rays
to avoid multihit in a segment, which will deteriorate
the timing signal from the segment and the position
resolution of the detector. This segmented surface isgrounded and the opposite surface has a high voltage
of 2000 V.
For a small dead space when the array is aligned, twocrystals are encapsulated in one cryostat so that theirhigh-voltage surfaces face each other. At present, 18
clusters of such a pair of crystals are considered to be
used for the array. To subtend the solid angle as large
as possible, the detectors should be aligned at a polar
angle of 90 degrees and as close as possible to the target
position. As one example fulfilling such requirements,
three units of six clusters are placed at 70, 90, and 110
degrees, and the distance between the target and thecenter of the detectors is approximately 10 cm. The
side surface of the detector faces the target in order
to extract an emitted angle of '"Y rays based on theposition sensitivity along the depth direction. When

~

-

200ov

E

,...u

z

Fig. 1. Illustration of a segmented Ge detector manufactured by Eurisys Mesures. Its coordinate system is alsopresented.
*1*2

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

1.00

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100

150

200

250

300

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Fig. 2. Calculated results for the output signals from thepreamplifier, when the interaction occurs at the position of p = 0.9 cm and ¢ = 0.0 0 in a cylindrical coordinate system of the detector shown in Fig. 1. Theinteraction depth z is varied from 0.0 to 2.0 cm in a
0.1 cm step. The corresponding interaction depth foreach line is explained in the text. (a) Output signals
which are connected to the segment including the interaction points. (b) Total output signals from the detector , which is equivalent to the summation of signals
from nine preamplifiers .

the recoiling velocity (3 is 0.3, the detection efficiency
for 1.0 MeV '"Y rays is estimated to be more than 5%
using the Monte-Carlo simulation code GEANT-4 1)
for the above alignment.
A position sensitivity of better than the segment size
will be provided by pulse shape analysis of output signals from preamplifiers. Examples of simulated output signals are shown in Fig. 2, where the interaction
depth z is varied from 0.0 to 2.0 cm in a 0.1 cm step,and the radius and the azimuthal angle are fixed tobe 0.9 cm and 0°, respectively, in a cylindrical coordinate system. The calculation method for the signals
was described in Ref. 2. For events with z smaller than
0.9 cm, dashed lines are used to represent the response.
Their rise times, which are determined by the drifting
time for both electrons and holes to reach their relevant electrodes , distribute between 150 ns and 300 ns.
Among them , the line with the longest rise time is related to the event with z of 0.0 cm, and that with theshortest rise time is seen when the interaction occurs

167

at z of 0.9 cm or almost at half the depth of the detector. Because both electrons and holes drift at almost
constant velocities under the present condition of electric field, a similar explanation can be applied to theevents with z from 1.0 to 2.0 cm, which are indicated bysolid lines, and to the symmetric characteristics of risetimes particularly seen in the total output (Fig. 2 (b)).
The deviation between Fig. 2 (a) for the segment andFig. 2 (b) is due to the partial charge induced by electrons , or holes can be collected in one segment depending on the charge carrier position. Hence, to obtain theinteraction position, pulse shaping has to be performed
to distinguish two signals with the same rise time but
different shapes.
As one of the methods of pulse shaping, zero crosstimings are investigated for signals obtained by differentiating twice and integrating four times with a time
constant of 50 J-LS (CR2-RC 4 shaping). The results areshown in Fig. 3. The interaction points are shown

500~~~~~~~~~-'~~~~~~~~~

(>

*
rn
5

a;
.....

400

0

E-<

". . *. .****' 0"."Q.. .. * *
~,;:)

~""'
.~ . '. ,

~

..

350

. *t.
:r

450

(P(cm). _(e» _ (0.0. 0.0)
(P(cm). _(e» _ (0.3. 0.0)(p(cm). _(e» _ (0.3. 30.0)(P(cm). _(e» _ (0.11. 0.0)
(P(cm). _(e» _ (0.11. 30.0)(p(cm). _(e» _ (0.11. 0.0)(p(cm), _(e» - (0.11. 30.0)(p(cm), _(e» _ (0.11, 46.0)(P(cm). _(e» _ (1.2, 46.0)**~$j;'**

300L-~~~~~~~~~~~~~-L~~~~~

300

350

400

450

500

Segment 4 (nS)

Fig. 3. Zero cross timings for CR2-RC 4 -shaped signals,
where a signal is generated from the preamplifier including the interaction points and the other originatesfrom the summation of output signals produced by ninepreamplifiers. Interaction points are shown in the cylindrical coordinate system for their radius p and their azimuthal angle ¢ . The interaction depth z distributes
from 0 cm to 2.0 cm in a 0.1 cm step, and corresponding
points are located counterclockwise.

168

20000r-------------------------------~

15000 f.->QJ]..!II:lO...........
III

1::::l10000 f -CIld1200[6]

D.S. Corrected

1000
800

......... 600

~ 400

0

U

0

u

200

5000 f -0980

990 1000 1010 1020

Energy (keV)

0

I

0

250

~\.
500
750
1000
Energy (keY)

I
1250

1500

Fig. 4. Doppler-corrected energy spectrum for I rays emitted from recoiling nuclei with {3 of 0.3.

in the figure for their radius p and azimuthal angle
cp. The interaction depth z distributes from 0 cm to
2.0 cm in a 0.1 cm step , and corresponding points arelocated counterclockwise. For events with the same p
and cp, the shortest distance between the points corresponds to about 3 ns. The information on p and cp
will be obtained from the transient signals generated
in neighboring segments. For example, deviation fromthe center position of a segment in a horizontal direction is expected to be evaluated from the amplitude
ratio between signals from the left and right neighboring segments. Therefore, a position resolution of 1 mm
will be achieved along the z direction.
Under the assumption that the position resolution
is 1 mm along the z direction, the effect of Doppler
correction is simulated for previously described alingnment of detectors using the code G EANT -4. Figure 4
shows the obtained Doppler-corrected energy spectrum
for, rays emitted from recoiling nuclei with (3 of 0.3.
The simulated energy resolution is about 8.0 keVin
FWHM. In the simulation, the effect of multihits is
not completely taken into acount yet. Experimental
confirmation of the simulation including the multihit
effect is now in progress.
References
1) GEANT4:
Detector Simulation Toolkit (CERN,
Geneva, 2000).
2) M. Kurokawa et al.: CNS Ann. Rep. 2000, 70.

RIKEN Accel. Prog. Rep. 35 (2002)

A hybrid array for charged-particle and f detection
H. Hasegawa,*1 T. Motobayashi,*1 S. Takeuchi,*1 H. Kawasaki,*1 K. Demichi,*1
H. Murakami ,*1 A. Saito,*1 and S. Shimoura*2
Recent development of radioactive beams has allowed extensive nuclear structure studies of unstable nuclei. We plan to construct a hybrid array forcharged-particle and I'-ray detection to be used in the
RI beam factory (RIBF) which will produce a wider
range of nuclei far from stability, than those producedby the present facility.
One method of studying structures of unstable nuclei
is to measure I'-rays from fast-moving residual nuclei,
with velocities of 30- 50% of the speed of light. It allows
one to determine the transition probability excitationenergy, and level scheme of the nuclei. However, due tothe high beam velocities, the I'-ray energy is Dopplershifted depending on the emission angle with respect
to the direction of the residual nuclei, and experiments
are performed using a very-low-intensity beam to study
very unstable nuclei. In such a case, high angular resolution and efficient detection of I'-rays are strongly
desired.
For particle transfer reactions in reversed kinematics, the angular distribution of light recoil particles provides important information on the specific reaction
process.
Thus, a system including ,-ray and charged-particle
detectors has been designed to be applied to experiments in RIBF. The , -detector is a granular array of
160 NaI(TI) scintillators which is capable of high angular resolution and efficiency. The charged-particle detector is an array of CsI(TI) scintillators which can provide good particle identification of 1,2,3H, 3,4He, heavy
ions and I'-rays . Figures 1 and 2 show schematics ofthe detectors. These systems can be combined according to the purpose of the measurement.
The complete setup of the NaI(Tl) array consistsof 160 NaI(TI) scintillators surrounding the target.
Each scintillator is of a rectangular shape with a sizeof 40 x 80 x 160 mm 3, coupled to a 38 mm-</> photomultiplier tube. Eighteen layers, each of which consists of 4- 12 scintillators, are arranged coaxially withrespect to the beam axis, and are closely packed tocover the angular range of 14- 166°. The distance fromthe target is 40 cm for the layer at 90°. The total lengthof the system along the beam axis is about 90 cm. The
angular resolution of , -ray detection is about 6° at 90°,
where the Doppler effect is at a maximum. The efficiency and the ,-ray energy resolution were simulated
by means of the GEANT code. l ) Figure 3 shows theenergy dependence of the photo peak efficiency andthe energy resolution (FWHM) from residual nuclei*1 Rikkyo University*2 Center for Nuclear Study, University of Tokyo

Fig. 1. Schematic of half of the NaI(Tl) array which consists of 80 crystals.

Fig. 2. Schematic of the CsI(Tl) array which consists of
312 crystals.

moving with vic = 0.4. The performance is enhanced
compared with the previous NaI(Tl) array consistingof 68 NaI(TI) scintillators, whose efficiency and resolution are about 20% and 100 keV at E'"Y = 1 MeV,
respectively.
The criteria for designing for the CsI(TI) ball aregood charged- particle identification capability, highangular resolution, and compact geometry.
The
CsI(Tl) scintillator is effective for light-particle identification,2,3) and its light can be collected by a silicon photo diode that provides minimal mass compared

169

300
50

.-...
~

40

'-'
~
C)

~

,,

,,

,

,
,,

,

250
200

30

Q)

C)
'+-4
'+-4

~

:I:
~

150

.-...

100

...::::

~

.1""1
.1""1

I-%j

(t)

20

r::Ll

10
0

'-'

50

0

1

2

3

4

0

Ey (MeV)Fig. 3. Calculated efficiency (solid curve) and FWHM
(dashed curve) of the Nal(Tl) array as functions ofthe , -ray energy E,,/ from residual nuclei moving with
vic = 0.4.

tals, form a hemisphere with the target at its center. The radius of the CsI(Tl) ball is 15 cm at thecenter of the crystal and 21 cm at the outer diameter
including the photodiode. The high angular resolution of 5° in full width allows for precise determination of the angular distribution of recoil particle nuclei resulting from a reaction. Furthermore, due toits compactness, one can install the CsI(Tl) ball ina vacuum chamber. Particle identification is accomplished by pulse shape discrimination based on theballistic deficit method and/or zero-crossing method. 2 )The good charged-particle identification capability of
the CsI(Tl) ball will enable selection of exit channels
for detailed spectroscopy.
The construction of the hybrid array will be carried out during the year 2002 in collaboration withATOMKI (Nuclear Research Institute of Hungarian
Academy of Science).
Referenceswith a photo multiplier. The CsI(Tl) ball consists of
312 crystals, each of which is of a rectangular shapewith a size of 16 x 16 x 50 mm 3 , directly coupled toa 10 x 10 mm 2 silicon photodiode. Assemblies, eachof which is composed of four individual CsI(Tl) crys-1701) GEANT3: Detector Description and Simulation Tool
(CER ,Geneva, 1993).
2) J. Getraz et al.: Nuel. lnstrum. Methods Phys. Res. A
399 , 407 (1997).
3) D. G. Sarantites et al.: Nuel. lnstrum. Methods Phys.
Res. A 381 , 418 (1996).

RIKEN Accel. Prog. Rep. 35 (2002)

Development of reaction-suppressed total-energy detector
T. Suda, M. Chiba, D. Courallet,* R. Kanungo , T. Kato , A. Ozawa, 1. Tanihata, T. Yamaguchi, and T . Zheng
We report here on(1) the responses of several inorganic scintillators,
such as NaI(Tl), CsI(Tl) and GSO, to an energetic ion beam of a 70A MeV 180, and(2) the development of a "nuclear-reaction-suppressed" detector to reduce the contribution of
nuclear reaction inside inorganic scintillators.
A total-energy detector, which has a good energy
resolution and small contribution of nuclear reaction
inside the detector, is very important for particle identification, for example, by the conventional !:lE-E
method, in reactions involving heavy ions. The total
kinetic energy of radioactive isotope beams provided
by the present RIPS facility normally exceeds a coupleof GeV, consequently the light output from, for example, the NaI(Tl) crystal is high enough to achieve anenergy resolution of better than 1%. Indeed, as shownin Fig. 1, a NaI(TI) detector is shown to have an excellent total-energy resolution of 0.7% (FWHM) for a
22Ne beam of 1l0A MeV measured at RIKEN.
A serious problem in particle identification using
such crystals is , however , background due to nuclear
reaction inside the crystal, which generates a long tailtowards the low-energy side (and a small tail on 'highenergy' side) in the pulse height spectrum, as clearlyobserved in Fig. 1. In the case of the 110A MeV 22Ne
beam, about 7% of the events suffer from the nuclear
reaction inside the NaI(Tl) detector.
One way to eliminate such a nuclear reaction contribution is to divide the crystal into several layers in--.. ...-22Ne (l10A MeV)

103

o

1000

2000

-0.7%
(FWHM)

3000

4000

ADC (ch)Fig. 1. Pulse height spectrum of the NaJ(Tl) detector for
22Ne beam of 110A MeV.
Ecole des Mines de Nantes, France

Fig. 2. Schematic view of the reaction suppressor.
total E detector is placed inside the suppressor.

Theorder to check the energy loss in each layer. This isbased on the fact that the energy loss in one layer
where the nuclear reaction takes place may be different
from the expected energy loss. It is, however, difficult
to construct such a detector at the RIPS experiments,
since the range is normally quite short (less than --.. . a
few cm) and a crystal such as NaI(TI) is (very) hydroscopic.
The method we take to eliminate the nuclearreaction contribution inside the crystal is to detect escaping particles from the crystal in order to tag the nuclear reaction. Since some of the beam energy become
invisible in a pulse height spectrum, neutral particles
and/or light ions are supposed to be emitted from thecrystal.
For this purpose , a "nuclear-reaction suppressor"
was constructed; the schematic drawing is shown in
Fig. 2. It consists of six plastic scintillator bars
(10 x 20 x 40 cm 3 ) , each of which is viewed by two phototubes at both ends. The NaI(TI) detector was placed
inside the suppressor; the suppressor covers about 96%
of 471' geometrically. In order to keep the detection efficiency for neutrons as high as possible, the detection
threshold was set to be lower than 100 ke Vee (electronenergy equivalent) .
We carried out a measurement of the "nuclearreaction suppression" capability of the suppressor using an 180 beam of 70A MeV at the E1C beam courseof RIKEN. In addition to the NaI(TI) crystal, we also
employed CsI(TI) and GSO crystals as the total-energy
detectors to measure their response to an energetic ion
beam, and the suppression efficiency of the suppressor. The dimensions of NaI(TI) and CsI(TI) crystals
are 3/1 ¢ x 6 cm, and those of GSO are 4 x 4 x 4 cm 3 ,respectively. All crystals were optically coupled to 3/1
phototubes (HAMAMATSU R6091).
The energy resolution and the nuclear reaction rate171

of each crystal for the 18 0 beam are summarized inTable 1. The energy resolutions of CsI(Tl) and GSO
relative to NaI(TI) are found to be consistent with therelative light output of these crystals. (Strictly speak-

Table 1. Energy resolution, nuclear reaction rate inside
crystals and the nuclear suppression efficiency of the
NaI(Tl), Csl(Tl) and GSO detectors for the 70A MeV
18
0 beam. The threshold of the suppressor is set to be
100 keVee.
.
crystaldensity(g/cm 3 )
3.67
4.53
7.13

NaI(Tl)CsI(Tl)
GSO!:::.E/ E(% (FWHM))

tail
(%)

0.95
1.5
1.8

6
5.2
4.4

rejection
(%)
64
59
81

104
1()3

102
10

10 2

-= 10
~
......

=
= 102
10
Q

e.J

1

102
10
1

0

500

1000

1500

2000

NaI(TI) ADC (cb)Fig. 3. Nal(Tl) pulse height spectra gated by the suppressor with different thresholds.

172

ing, it is the peak width relative to the peak position,and not the energy resolution. This is because thelinear relationship between the pulse height and totalenergy is not yet confirmed. It is, however, sufficientfor our purpose of particle identification.)
Figure 3 a) shows the NaI(TI) pulse height spectrum
for the 18 0 beam, where the sharp peak at around 1500
channels corresponds to total energy deposit. In thesame figure , the NaI(Tl) spectrum gated by the suppressor, whose threshold is set to be 100 keVee, is alsoplotted together. Here, at least one scintillator barof the suppressor is requested to be fired. The react ion suppressor is quite effective, and about 64% of thenuclear reaction events distributed in the tails of thepulse height spectrum can be eliminated. Figure 3 b),c), and d) show the NaI(TI) spectra gated by the suppressor with different thresholds as indicated in the
figures.
As seen in Fig. 3, the rejection efficiencies rapidly
decrease with higher thresholds becomes rapidly small,which may indicate the emission of low-energy particles including neutrons. Setting a lower threshold isessential for achieving high rejection efficiency.
Finally, let us briefly discuss the experimental results for the GSO detector. The nuclear reaction rateof GSO is found to be lower (4.4%) than those of
the other crystals, probably due to the higher average
atomic weight, which gives a smaller number of nuclei in a fixed range. In addition, the suppression rateof the GSO detector measured under the same conditions is found to be more than 80%. The facts that
GSO has very fast response (~60 ns), relatively highlight output (~30% of NaI(Tl) light output), absenceof hydroscopicity and much greater radiation hardness(10 9 rad) than, for example, NaI(Tl) (10 3 rad),!) makethe GSO crystal be a good candidate for a total-energy
detector in future radioactive beam facilities.
We plan to modify the suppressor in order to identify
the emitted charge, and then, to examine the responsesof these crystals and the reaction suppressor using ahigher-energy ion beam available at NIRS (National
Institute of Radiological Sciences).
References
1) V. V. Avdeichikov et al.: Nuc!. lnstrum. Method Phys.
Res. A 349 , 216 (1994).

RIKEN Accel. Prog. Rep . 35 (2002)

Development of a beam loss monitor
Y. Uwamino, S. Ito, K. Matsuno ,* l and T . Hirota*2
The beam loss at IRC, SRC and the beam lines of the
RI beam factory (RIBF) must be precisely controlled,because an excessive loss may cause an excessive levelof radiation in and around the facility. Conventionalradiation monitors are working at the present Nishinabuilding, and one or two devices are placed in eachexperimental room and the cyclotron vault. Similar
monitors will be placed outside the bulk shielding of
the RIBF, but a number of monitors will be necessary
inside the shielding to directly measure the radiation
produced by the beam loss. A conventional monitor
is accurate for the measurement of effective dose, but
it is expensive and not radiation-resistant. We needan inexpensive and radiation-resistant device for the
RIBF .
A simple plastic scintillator can be used as a beamloss monitor , because it is sensitive to high-energy neutrons, which are the dominant source component for
thick shielding. A prototype of the monitor was fabricated, and its response was measured at the El room of
the Nishina building. The scintillator used was 2.5 cm
in diameter and 2.5 cm in length ; the count rate of thediscriminator and the anode current can be read for
low-level and high-level radiation fields, respectively.
The test neutron fields were created by the 135MeV lu 4He and the 135-MeVlu 14N beams which
bombarded a 2.5-cm-thick copper target. The scintillator was placed at several angles from the beamline and the distance from the target was about 1 m.
A neutron rem counter (Aloka TPS-451S) was placed
behind the scintillator for comparison and another rem
counter placed at a stationary position was also used
for the beam current reference. The beam current was
dynamically changed at each angle, and the responseto the beam current was measured.
Figure 1 shows the response of the anode current
to the He beam. The ordinate is the voltage which isconverted from the anode current. The voltage is fairly
proportional to the current, and has a dynamic rangeof more than three decades. Figure 2 shows the proportional factors for He and N beams. Since the highenergy neutrons have a strong forwardness , the angulardependence of these factors shows steep curves. The
dynamic range of this monitor can be expanded when
the discriminated count is also read.

*1

*2

o
o
o

x

vo i tage@()deg •vol tage@15deg
vo 1tage@3Ddeg
vo 1tage@6Ddeg- -+ v01 tag8@90deg --Y=1D.73*X @Ddeg·········Y=(i .611*X @15deg•••••• Y=(i. 1DD*X @3Qdeg. ...

__ ·_ : .-:-:~_ Y=O.o.32MX@aDde9. - . - Y=(i. D28D*X @gDdeg~~1DJ I:-

••Li
.p" .

•. rz

--

--- ,

--.-.- .

.

~.'

•

L

·.". .7··.....~:/"

I

Q)

--c

~

.j!'

.

/~ /.~ .

. --/- - --- -;{'- -- ;r;~ - - ---'- - ----- .. -;;1....
• '.

--c......a· . •

~

:;

~ 10'

1:-

....

------- -- .••--••:/

.,#

: .~.

~.

~>:>. ·J'••.' : /,'if-

.~
.,.0

100 L -........................o.L--'---'-'----'---'--'-'u.L----'-----'-................J...................L.L-L-'-""----'-"--'---'--'u.uJ

10°

10. 1
Faraday cup current, 1D' IOC/min

Fig. 1. Anode current response to the He beam current.
The monitor was placed 1 m from the target , and theanode current was converted to voltage.

'2

~ 10.

1

- e - 4He2+ 135 MeV /u• •• -B •••14N7+ 135 MeV/u

r:";G,~g 10. 1I[i'l!j••.~ !-. ~ -- : ----••• ----:.

.. ...

....

'Q;bJ)~ 10.. 2... ---- . --- -- ...•.. ---- .. --

--,j

~

.l3. ••••••: ..........

o<,:; ~~~.::::.:..:;~:..:..

E:J. _>

10.3 '----'-----'-------"'------'-------'------'--'-...L......&.--I....--'--'---'---'--'--'--'----'---'--'-----'--'--'---'
-20.

20.

40.
angle , deg

60.

80.

100.

Fig. 2. Ratio of the voltage (m V) to the beam current(10 - 10 C j min) at various angles from the He and N
beams.

Fuji Electric Systems Co. , Ltd.
Yanagawa Engineering Co.

173

RIKEN Accel. Prog. Rep. 35 (2002)

Absolute calibration of deuteron beam polarization at intermediate
energies via 12C(d, a)loB*[2+] reaction
K. Suda,*1 H. Okamura,* 1 T. Uesaka,*1 H. Kumasaka,* 1 R. Suzuki,* 1 H . Sakai,*2 A. Tamii,*2 K. Sekiguchi,*2
K . Yako,*2 M. Hatano ,*2 Y. Maeda,*2 T. Saito,*2 T. Ishida,* 2 N. Sakamoto, Y. Satou,*3
K. Hatanaka,*4 T. Wakasa,*4 and J. Kamiya*4At the RIKE
Accelerator Research Facility(RARF), the beam polarization of the intermediate energy deuteron is measured using a polarimeter (high-energy polarimeter) , which applies the dp elastic scattering as a polarimetry. 1) We have reported the calibration of the analyzing powers for thed- p elastic scattering at 270 and 140 MeV using the
12C(d~ a)10B[2+] reaction. 2) Since the analyzing power
A zz of 12C(d~ a)10B[2+] is unity at 0°, the ambiguity ofthe beam polarization can be minimized. The results
were compared with the calibration data obtained using the 12C( d~ p ) 13 C reaction 1) or 3He( d~ p )4He reaction 3) at low energy. Although the agreement is good,
we need more angular points to compare the angular
distributions. Thus, we calibrated the d-p elastic scattering at six angles at Ed = 270, 200, and 140 MeV
as shown in Table 1. We usually measure the beampolarization at ec .m . = 86.5°, 82.5°, and 110.0° for
Ed = 270, 200, and 140 MeV, respectively. A few
other points are selected to measure the angular distribution of the d-p elastic scattering. Also the angle
c .m . ~ 120° is selected , because the tensor analyzing power T 20 (= - (Axx + Ayy) / v'2) takes nearly the
maximum value irrespective of the energy measured.
Since the cross section of the (d, a) reaction is hundreds of times smaller than that for the d-p elastic
scattering, it takes several hours to obtain sufficient
statistics of the beam polarization, even with a beam
intensity of 100 nA. Thus, in this calibration, we measured the d-p elastic scattering at six angles by one
shot. In the beam polarization measurement, we detect both deuterons and protons in kinematical coincidence. We usually use a relatively large solid angleof the plastic scintillation counters in order to obtainsufficient statistics within a relatively short time withsmall accidental events. However, the counters coverfour degrees of the scattering angle in the laboratory
system. It is too large for the purpose of this cali-eTable 1. Measured angles for d-p elastic scattering.

Ed (MeV)
270
200

140
*1
*2

*3
*4

174

Bc .m . (deg)80.6 , 83 .6, 86.6, 89.6, 92.6, 117.7
76.6, 79.5, 82.5, 85.5, 88.5, 117.4
82.0, 88.0, 94.0, 100.0, 110.0, 119.0

De partment of Physics, Saitama University
Department of Physics, University of Tokyo
Center for Nuclear Study, University of Tokyo
Research Center for Nuclear Physics, Osaka University

bration to measure the precise angular distribution of
the d-p elastic scattering. Thus, we constructed new
counters. For scattered deuterons, as the scattering angle measured is contracted in a narrow forward region
and a higher count rate is expected, one scintillation
counter is used as a fl..E counter for all of the angles except for c .m . = 120° . For recoil protons, six separate
counters are used, and the solid angles are determinedby protons. The angular spread of each proton counteris set to ,~.elab = 1.0° . One of the proton counters is
set at elab ~ 30° in order to detect both deuterons
and protons scattered to ec .m . ~ 120° . Four sets ofthese seven counters are set around the beam axis in
the directions of Left , Right, Up, and Down.
We used three polarization modes , (pz,pzz) =(0,0), (1/3, -1) , and (1/3, +1). The spin axis is directed perpendicular to the horizontal plane, which isparallel to the magnetic field of cyclotrons. These threemodes are switched every few seconds in order to reduce short-term fluctuation of the polarization. The
actual values of the beam polarization were about 70%
during the measurement.
The 12C(d~ a)10B[2+] reaction is measured using the
SMART spectrograph. A self-supporting natural carbon foil with a thickness of 8.79 mg/cm 2 is used for
Ed = 270 and 200 MeV, and a polyethylene film witha thickness of 5.8 mg/cm 2 is used as a carbon target
for Ed = 140 MeV. The beam intensity was 100 nA forall energies. The detector setup is the same as that inRef. 1. The analyzing power of this reaction is A zz = 1
at 0° due to parity conservation. Thus the tensor polarization pzz can be determined with less systematic
uncertainty. However , since this relation is valid only
at exactly 0°, it is necessary to measure the angular
distributions and extrapolate them to 0°. The extrapolation result for Ed = 270 MeV is shown in Fig. 1.
The magnitude of the vector polarization pz can be
deduced multiplying tensor polarization by one third .
This relation is fairly robust since it is not affected by
the efficiency of the RF transition at the polarized ion
source. The d-p elastic scattering is measured using
the high-energy polarimeter. A thin polyethylene filmwith a thickness of 30 p,m is used as a hydrogen target . The measurement is performed using the same
beam at the same with the (d, a) measurement . Thus,
the long-term stability of the beam polarization has noinfluence on the result.
When the beam axis is vertical as in the (d, a) measurement, there is no sensitivity to A xz . Therefore,e0.4 __-

____

0.0

b'

I

~:

0.2

a

00

Ay

,

o

~ -0.2~------~-----------~
Cb:
.,

0

.

::

e0°

'

'~ •• 00o-0.5____ 2------6

-0.4
,

o

••0".

5

o· :

BUll. (deg)Fig. 1. Angular distribution of the asymmetry of the
12C(J: a)10B[2+] reaction. The closed and open circles
represent the second and the third polarization modes,
respectively (see text). This asymmetry agrees with
pzzA zz at 0°. The results of the polynomial fit are
shown as solid and dashed lines. The fitted function is(asymmetry) = ao + a2 (p + a4 (}4 .

we also calibrated Ax z after the measurement of the(d, 0:') reaction at each energy. In order to precess thespin axis , we employed the swinger dipole magnet of
the SMART spectrograph, rotated to 90°. When thespin axis is perpendicular to the magnetic field of theswinger, the spin axis precesses by !:1/3 ::::: - 15° at theexit of the swinger, depending on the deuteron energy.
Since this precession angle is accurately calculated, theuncertainty for Axz is reduced. The d-p elastic scattering is measured simultaneously using the same beam
before and after the swinger with two polarimeters,
the high-energy polarimeter and the swinger polarimeter. The measured angles are Bc .m . = 86.5°, 82.5°, and110.0° for Ed = 270, 200, and 140 MeV, respectively.
The advantage of this method is that the spin axis(/3, ¢) before the precession can be determined even
without any information on the analyzing powers. The
result indicates that the spin axis of the deuteron beamfrom the cyclotron is inclined by 7- 10 degrees for all
measured energies.
The spin axis (/3, ¢) is necessary in order to extract
the polarization (Pz,pzz) from the (d, 0:') reaction. We
deduced the spin axis by fitting the data of d-p elastic scattering measured simultaneously with the (d, 0:')reaction, with the constraints that the ratios between
A xx , A yy , and Axz obtained from Axz measurement
are conserved. With the obtained polarization and theasymmetry of the d-p elastic scattering, all of the analyzing powers A y , A yy , A xx , and Axz for the d-p elastic
scattering are deduced. The results for Ed = 270 MeV
are shown in Fig. 2. The errors shown are statistical00.0------~-------------

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Ed = 270 MeV. The present results are indicated byclosed squares. The data indicated by open circles aretaken from Ref. 1 and those indicated by open squares
are from Ref. 4. The errors are statistical ones only.

ones only. Further analysis for Ed = 200 and 140 MeV
is in progress.
References
1) N. Sakamoto et al.: Phys. Lett. B 367, 60 (1996).
2) K. Suda et al.: RIKEN Accel. Prog. Rep. 34, 186(2001).
3) T. Uesaka et al.: RIKEN Accel. Prog. Rep. 33, 153(2000).
4) H. Sakai et al.: Phys. Rev. Lett. B 84, 5288 (2000) .

175

RIKEN Accel. Prog. Rep. 35 (2002)

Advanced network for RIKEN Accelerator Research Facility
T. Ichihara, Y . Watanabe, A. Yoshida, and K. Yoshida
The security of the computer network is a very important issue at the RIKEN Accelerator Research Facility (RARF) . Recently, many personal computers in
RARF are connected to the Internet via the RIKEN
Local Area Network (LAN). But it is not easy to maintain the security of each personal computer at a certain level, when they are managed by individual users.
Many security holes have been discovered one after another for various operating systems (OS) and it has
been necessary to update the OS or apply patches toclose the security holes each time.
The network Intrusion Detecting System (IDS) has
been installed at the boundary of the RARF LAN and
RIKEN LAN in order to monitor unauthorized access. The IDS consists of the free software SNORT, 1)
mySQL,2) ACID3) and RedHat 7.1 Linux pc. The
IDS detects IP packets of the unauthorized access to
the RARF LAN and logs them through the mySQL
database . The IDS is very helpful in improving thesecurity of RARF LAN , however , security is still not
sufficient . The IDS records security-related events but
it does not prevent unauthorized access itself.
Under these circumstances, we decided to introduce
a new advanced network to the RARF , where the security of the computers is maintained at a sufficientlevel with minimum effort.
Figure 1 shows the configuration of the RARF advanced LAN.
The RARF Advanced LAN consists of two components, RARF private LAN as shown in the lower partof the figure and the RARF global LAN as shown in
the upper part.
All the computers connected to the RARF private
LAN are assigned private addresses statically or dynamically. To access the Internet , these private addresses are translated dynamically to the global address by a firewall machine (PIX 535). There is no* Gigabit connection# Gigabit trunking VLAN*

way to access the private LAN directly via the Internet
and therefore the security of the computers connectedto the private LAN is maintained at a higher level.
We assume that most of the personal computers managed by individuals are connected to the private LAN.
Also all the printers are connected to t he private LAN.
These private LANs are divided into several groups(subnets) categorized by the buildings and laboratories. The routing of the IP and AppleTalk protocols
between these subnets is carried out for convenience.
All the computers connected to the global LAN are
assigned global addresses. We assume that the server
computers such as those with Web servers are connected to the global LAN. No address translation iscarried out when accessing the Internet. However, theglobal LAN is connected to the Internet via the firewall machine (PIX 535) . At the firewall, t he accesslimitation rules are applied to all the computers which
can be identified by port number and network addressbases one by one. By the default setting, no access into
the computers from the Internet is allowed. This minimizes the ability of unauthorized access to the computers connected to global LAN from the Internet.
In order to prevent virus infections via E-mail, avirus detecting and eliminating system has been installed to the central mail server (RARFAXP) of the
RARF in the summer of 2001. This system detects andeliminates viruses contained in incoming, outgoing andlocal E-mails.
The migration of the current LAN to the new advanced LAN was started in November 2001 and has
been completed in February 2002.
References
1) http ://www .snort.org/
2) http: //www .mysql.org/
3) http: //www.cert .org/kb/acid/

RARFAXP
UNIX cluster

~

PIX

'\V

login server...-l1li printer server

DHCP
servers(IDS: Intrusion Detecting System)

ip, appletalk routing

Fig. 1. Configuration of the RARF Advanced LAN.

176

RIKEN Accel. Prog. Rep. 35 (2002)

RIPS control system with EPICS
K. Yoshida, M. Kobayashi-Komiyama, M. Sugimoto,* and T. Kubo
The computer control system of RIPS has been
upgraded to one based on the Experimental Physics
and Industrial Control System (EPICS).1) The recentchange of the control system of the RIKEN Ring Cyclotron 2 ) has rendered the existing RIPS control system 3 ) obsolete since they shared the same control computer. To ensure the compatibility of their respective
software, a new control system of RIPS was developed with EPICS same as that of the RIKEN Ring
Cyclotron.
Most parts of the control software for magnets, slits
and actuators are taken from those developed for the
cyclotron. Specially developed is the B p-scaling mode
for all beam-line magnets in RIPS. Since RIPS is thesecondary beam separator, the setting of the magnetsof RIPS is often carried out by Bp-scaling from theprimary beam to the desired secondary beam. Therefore , a convenient method is required for the scaling.
This is carried out with the support of the EPICS
database program and the EPICS sequencer. In the
database program , the required currents of magnets
are calculated from the given Bp value and the excitation function of the magnets and then they are set

into the magnet power supply. The sequencer sets thegiven Bp value in the control program for each magnet. Parallel processing is taken into account whenever hardware permits. This reduces the setting timeof the magnet currents greatly in comparison with theold control system.
The user interface is created by using the DM2K display program. The program runs in the server machine
and we access it through the X-terminal machine. Figure 1 shows the control windows appeared in a terminal. Most controls are made by setting the numericalvalue in a value field and pressing the set button next
to the field. More stable operation is accomplished byusing EPICS.
References
1) http:/ / www.aps.anl.gov /epics/2) M. Komiyama, 1. Yokoyama, M. Nagase, E. Ikezawa, M.
Fujimaki , R. Abe , T. Tanabe, and M. Kase: Proc. 13th
Symp. on Accelerator Science and Technology, Suita,
2001-10, in press.
3) N. Inabe et al.: RIKEN Accel. Prog. Rep. 24, 100(1991) .

Fig. 1. Control windows appearing in the terminal.

Mitsubishi Electric Control Software Corporation

177

RIKEN Accel. Prog. Rep. 35 (2002)

Trial of RTLinux for embedded control and measuring system
J. Fujita
Ethernet is about to become as necessary standard
interface as RS-232C or GP-IB is usually furnished incontrol and measuring tools. Adapter units that convert these ordinary standard interfaces directly to Ethernet are already being sold as attachments to thesetools, and if the product specifications are within therange of our purpose , this combination is sufficient tobe embedded in the system. However, actual requests
are often out of range of the specifications of manufacturer's products. The conditions for the control andmeasuring tools to be embedded within an electric apparatus are as follows.
(1)
(2)
(3)
(4)
(5)

The size is as compact as possible.
Ethernet is the on-board standard port .
The operating system can treat real-time events.
Expansion of function is free and easy.
It is easy to obtain hard and soft elements inview of cost and time.

Many plans have been proposed for the embedded control system but the Silicon-Linux (Si-Linux)
project l ) seems to satisfy the above conditions and beeasy to access. A Real-Time Linux (RTLinux)2) program runs on a small single board computer (SBC) inthis project. The RTLinux system operating directlyon the PCM-5820 SBC (Advantech) is offered from the
project in the form of compressed file called Si-Linux.
The board is small in size (145 mm x 102 mm) and has
as many interfaces as an ordinary PCI AT computer,including the Ethernet interface. It also provides industry standard architecture (ISA) expansion bus for
PC/104 standard and a socket for a compact flash cardon the board. The use of the compact flash card isoutstanding and makes fabrication of the system very
simple. The kernel and modules of the RTLinux aredeveloped and written into a blank flash card in a notebook or desktop personal computer (PC) other thanthe SBC. The flash card is inserted into the socket on
the SBC and when the SBC is turned on, the RTLinux
operating system is booted from the flash card andstarts its tasks. Since the content of the flash card is
not deleted by the sudden cutoff of power, the flashcard system is more reliable and stable than the harddisk system. Application programs are developed in
the form of Linux module in the note book or desktop
PC and copied to the flash card in the SBC by the
Ethernet LAN .
The environment for development of the Si-Linuxwas built using the following procedure. Here , thefollowing systems are used: the PCM-5820 SBC,
the 420CDT note book PC (Toshiba) and an ordi-

178

nary desktop PC with motherboard of SV-1l9 ATX(ACER). A compact flash card has the capacity of
16 MB with a fully compatible IDE interface.
First, debian GNU Linux Ver. 2.2 is installed in each
PC. PCMCIA card service must be set on the notebook PC so that the compact flash card can be recognized as an IDE fixed disk. In the case of the desktop PC, the compact flash card is connected to thesecondary IDE port through an IDE cable, the endof which has been modified for direct insertion of thecard, and is also recognized as a secondary disk without the PCMCIA card service. Since the compact flashcard has much less storage capacity than a hard disk,
some directories and files must be compressed for conservation of storage capacity. Therefore, the option offile compression must be enabled when the kernel isconfigured. Server functions for LAN, telnet, ftp andnfs are required in both PCs for networking with the
SBC. When installing the Si-Linux, the archived fileof Si-Linux must be decompressed to a directory in the
PC. Since the file size of this system is larger than thatof the compact flash card, other directories, except for
directories I, Idev and Iboot, are compressed as mentioned above, and this modified fi le system is written
into the fl ash card .
Since the minimum amount of software of RTLinux
is installed in the SBC, the RTLinux system with thesame configuration as the SBC must be introduced in
the PCs for program development. The RTLinux system is distributed by the RTLinux project as a patch
file for the conventional Linux kernel. We applied the
RTLinux patch to the kernel version 2.2.14 of Linuxand reconfigured the kernel to match t he SBC.
Two test programs that use API of RTLinux including time scheduling were developed and successfully
run on the SBC. One generates square wave signalof a 30 J-lsec period in the parallel port, that is, theprinter port of the SBC. The other outputs pulses
on the PCM-3724 digital 1/0 board (Advantech) thatis connected to the PC/104 standard bus in the SBC.
The API of hardware interrupt has not been tested yet,but the RTLinux on the target and developed systems
works accurately, as expected.
If an AID converter board with the same PC/104
standard is added, this board system will become amore usable tool as a small remote embedded control
system in the Ethernet LAN.
References
1) http://www.si-linux.org/
2) http://www.rtlinux.org/

RIKEN Accel. Prog. Rep . 35 (2002)

Simulation of imaging using Compton camera
Q. Y. Pan,*1 ,*2 Y. Gono,*1 S. Motomura,*1 T. Sasaki ,* 1 Y. F. Yang,*2 M. Hirasawa, S. Enomoto,Y. Yano, and K. Asahi
In comparison with the other ')'-ray cameras (e.g.,
SPECT and PET) used for source imaging, the novel
Compton camera produces images using the kinematics of Compton scattering. Its potential advantages
are increased efficiency and multiple angular views of
the source distribution from a single position due tothe absence of the lead collimator. Three-dimensional
images can also be obtained using the Compton camera without moving detectors. If Compton cameras
are used for clinical diagnosis, these advantages may
reduce the radiation dose administered to the patientin order to produce a useful image. First , the increased
sensitivity of the Compton camera will allow the use of
isotopes with lower activity levels and/or shorter halflives. Secondly, the reduced angular motion of the detectors will result in less time wasted between angularstops.
Compton cameras have been used in many applications in the fields of X-ray and ')'-ray astronomy,1) andthe nuclear energy industry for site and environmental
surveys. The source imaging research with HPGe detectors has been carried out by us. In this report, we
present the simulation method and the results of theuse of the first HPGe camera in our laboratory. This,),-camera consists of two separate HPGe detectors. 2)
The active volume of each detector is 50 x 50 x 20 mm 3 ,which is segmented into 25 units with an equal size of
10 x 10 x 20 mm 3 . The first HPGe detector is called
the "scatter detector." Its functions are to promoteand detect the position of interactions. The second detector is referred to as the "absorption detector" andits function is to absorb scattered ')'-rays. Both of thedetectors are used to measure the ')'-ray hitting position and deposited energy. The position of the interactions, including the scatter angle, limits the photon's
possible source location to a cone surface whose axis
is in line with the positions of the two interactions
and whose opening angle is equal to the scatter angle;
however, with multiple photons , the cone surfaces will
only cross at the true source position. The intersectionof this cone with an image plane generates an ellipse
with parameters which can be determined directly by
the measured energy deposited on each detector andthe interaction positions. A succession of the detected
Compton scattered events will generate a number of
ellipses. If a single point source is considered, theseellipses cross a common point, thereby defining the image point as shown in Fig. 1. In our previous work, theentire ellipse was used to produce the image. Actually,*1 Department of Physics, Kyushu University*2 Institute of Modern Physics, Chinese Academy of Sciences ,China

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source.

only one point of each ellipse is useful for the data
reconstruction. Here, we choose the common pointof ellipses for producing images. This new method
can improve the resolution and background suppression of images greatly. The image reconstruction for
a continuous-distribution source can be obtained bydirect summation of all the common points of the produced ellipses. The detected sufficient scattered events"i::'"

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1200
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The resolution (FWHM) is 4 mm in the X-and Ydirections.

179

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50 mm 2 • Six thousand events were used for the image.

will produce a statistically stable image.
Monte-Carlo simulations of our HPGe camera using the simulation tool GEANT 3.21 3 ) were performed.
Results of the simulations are presented in Figs. 2 and180

3 for images of a point source and a uniformly distributed volume source in the form of the letter M, respectively. It is evident in Fig. 2 that this new method
is able to produce point images with the correct position in all three dimensions, and that the images are
symmetric around all three axes. The point source image has a FWHM of ::; 4 mm in X- and Y-directions.
For the continuous source image, the source position
can also be reproduced correctly. The only distortionin the simulation is that the relative intensity cannot
be reproduced precisely as shown in Fig. 3. The intensities along the two legs of the M-source are slightly
weak compared with the other parts. This shortage
will be expected to be overcomed by the calibration of
the detector efficiency with spatial position in the future work. Although some distortions take place, thegeneral success of the reconstruction method is apparent. More images will be produced soon.
References
1) V. Schonfelder, A. Hirner, and K. Schneider: Nucl. Instrum Methods Phys. Res. 107, 385 (1973).
2) Y. F. Yang , Y. Gono, S. Motomura, S. Enomoto, andY. Yano: IEEE Trans. ucl. Sci. 48, 656 (2001).
3) R. Brun et al.: GEANT3 Users ' Guide, DD/EE/84-1,(CER , Geneva, 1987).

6. Material Analysis

RIKEN Accel. Prog. Rep . 35 (2002)

Mechanical properties of polyimide films implanted with metals
T. Kobayashi, A. Nakao, and M. Iwaki
Recently, metal-doped diamond-like carbons (MeDLC) have received attention due to their favorable
characteristics, such as a low friction coefficient. One
method of producing Me-DLCs is metallic ion implantation into polymers. Polyimide (PI) is very attractive not only for its mechanical and chemical stability
and high glass transition temperature, but also for its
ability to easily change its structure into amorphous
carbon by cross-linking due to ion implantation.
In this study, we chose the tungsten ion to form
compounds with carbon. We used a MEVVA-type ion
source without a mass separation system to obtain ahigh-flux tungsten ion beam. The average energy ofions is 190 keY. The chemical states of the implanted
atoms were investigated by X-ray photoelectron spectroscopy (XPS) and the cross-sectional structure of theimplanted region was observed by transmission electron spectroscopy (TEM). Friction coefficient measurements were performed using a pin-on-disk method withan alumina ball.
The shift in XPS spectra due to the charging-up
effect was corrected using the deviation of the CIs
peak from that originating from the polyimide standard sample observation (285 e V) . We estimated thechemical state of W implanted in PI to be WC, compared with standard sample observations of W metal
and the WC compound. A small number of WO
bonds exist at the surface of the specimen implanted
at 5 x 10 17 cm- 2 .
Cross-sectional TEM micrographs of the specimens
implanted at 1 x 10 16 cm- 2 and 1 x 10 17 cm- 2 showedthat the cracks in the brittle implanted region were introduced by the microtoming process. In the case of
Ag, Cu and Pd implantation into PI, we reported thatthe formation of nanosized crystalline colloids of metal
due to diffusion of the implanted atoms during implantation was observed. In contrast, in the case of W
implantation, no aggregation of W atoms around the
projected range was observed. The formation of WC
bonds seems to suppress the migration of W atoms.
Figure 1 shows two sets of results for the friction coefficient measurement in a pin-on-disk sliding test witha load of 5 N. The friction coefficient of the specimens
implanted at less than 1 x 10 16 cm- 2 increased fromthat at the beginning of the observation. On the other
hand, in the case of specimens implanted at more than1 x 10 17 cm- 2 , it initially decreased. We assume thatthe difference is due to products related to tungsten
in the shallow region because no morphological change
due to implantation was observed in the surface by
SEM. The friction coefficient of the unimplanted specimen varied from 0.4 to 0.8 and reproducibility was
poor.

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The friction coefficient at a sliding distance of 6 m isplotted in Fig. 2_ It will be minimized at a fluence ofbetween 10 16 cm- 2 and 10 17 cm- 2 . While it is affectedby the thickness of the PI film , the minimum value ofthe friction coefficient obtained in the present study
was 0.14 in a specimen implanted at 1 x 10 16 cm- 2 ,which is comparable to that of DLC produced on ametal substrate by a plasma processing method. The
reason for the variation in the results is still being inspected; we assume that it will be due to the nonuniformity of the fluence particularly in the outer regionof the implantation area. The role of W-C bonds in
reducing the friction coefficient is still not clear. However, it is shown that tungsten implantation at a fluence of between 10 16 cm- 2 and 10 17 cm- 2 can resultin low friction and a wear-resistant surface on the PI
film.

181

RIKEN Accel. Prog, Rep, 35 (2002)

Development of a highly sensitive high-resolution in-air
particle-induced X-ray emission (PIXE) system: II
K, Maeda, K. Hasegawa,*1 H. Hamanaka,*1 M, Maeda,*2 S, Yabuki , and K. Ogiwara
Particle-induced X-ray emission (PIXE) analysis ofhigh energy-resolution is one of the most effective tools
for direct investigation of chemical bonding states ofatoms in target materials. Recently, we constructed
a compact crystal spectrometer system equipped witha position-sensitive proportional counter (PSPC) for
high-resolut ion PIXE measurements in air. 1) The utility of t he system for direct chemical state analysis wasdemonstrated by measuring Ka: 2) and Kj13) spectra ofthird period elements.
As the next step, we have developed a large-window
PSPC in order to increase the X-ray detection efficiency of the spectrometer system by one order of magnitude. A prototype of the large-window PSPC (multianode type) was reported previously.4) An improved
and practical version of the large-window PSPC, astacked-type assembly, has now been accomplished .5 )We installed a mechanism for t ime-resolved spectrum
measurements in the new spectrometer system.
The experimental setup is the same as that reported
in a previous paper 6 ) with the exception of the PSPC.
A target sample is placed in air and bombarded with a
2.1 MeV proton beam of 3 mm diameter. X-rays emitted from the target are analyzed with a flat single crystal, and detected using a large-window PSPC assembly.
The newly developed detector comprises a stacked
assembly of five PSPCs with a 512 x 5 channel analyzer.
Each PSPC employs a 7-J1m-diameter carbon fiber as
the anode. The position-to-channel conversion gains(~0.106 mm/channel) of the five PSPCs agree within±1 %. The sensitive width of each PSPC is 27 mm .
The total sensitive height is 7.4 x 5 = 37 mm, i. e. about
five t imes larger than that of the previous single-anode
PSPC. 1) Usually, we use a mixed gas of Ar+CH 4 (9: 1)
as the counter gas under a gas pressure of 1 bar. When
we use Kr+CH 4 or Kr+C0 2, the detection efficiency
is much improved, e.g, a factor of two in cases of P
and S Ka: X-rays. Thus, the sensit ivity of the present
spectrometer system is improved by five to ten times
compared to the previous one.1)
The ability of the system for carrying out rapid
chemical state analysis was examined by measuring
the chemical shift of P Ka:l ,2 line. Figure 1 (a) shows
two-dimensional data of P Ka: spectra obtained froma disc of Ca(H 2P0 4h·H 20 powder. The proton beam
current was 50 nA and the measurement time was 6 s.
After correcting the offset channel of each spectrum,
five spectra were summed and recorded on the lowest frame. Prior to the rapid measurements, t he offset
*1

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182

Faculty of Engineering , Hosei University
Tokyo University of Fisheries

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Analyzing crystal; Ge (111): O,158eV /channel.

channel values from the center PSPC were determinedwith a long measurement time (200s) using a BP powder disc as a reference material. The summed P Ka:l ,2spectrum of Ca(H2P04)2 ·H20 is compared with thatof BP in Fig. 1 (b). The spectrum of BP shown here
was also obtained with a measurement time of 6 s.
The rapid measurements were repeatedly carried out,changing the target from the sample one to the reference one alternatively. The shift of the P Ka:l,2 centroid in the spectrum of Ca(H 2P0 4h· H 20 with respect
to t hat of BP was determined to be 5.2 channels witha standard deviation (S .D. ) (reproducibility, n = 5)
of ±0.3 channels, corresponding to an energy shift of
0.82 ± 0.05 eV. The reproducibility of 0.05 eV obtainedhere is sufficient to estimate chemical bonding states.
8ince it was ascertained that the rapid chemical
shift measurement was sufficient to distinguish chemical species, we installed a mechanism to measure thetime variation of PIXE spectra due to chemical reactions. Up to twenty measurements can be carriedout repeatedly and successively. Data of (512 ch x 5anodes) x 20 recorded on a computer are converted
to 20 summed-up time-resolved spectra by software.
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8 Kal,2. The targets are (a) aerosol and (b) marine
sediment samples. The aerosol sample was collected
on a Polyfion filter for 3 weeks in May 2000 at Wakoshi. Using a core sampler, the marine sediment sample was obtained from Tokyo bay at a water depth of
20 m in November 2000. The core sample was cut into
1-cm-thick slices and kept frozen until the PIXE measurement: a portion of the defrosted sediments was
deposited on a Millipore filter. The filters loaded withsamples were used as PIXE targets without any pretreatment.
Mo8 2 was used as the reference material for 8 KCXl ,2.
The proton beam current was 30- 40 nA. The measurment time of each spectrum was 100 s. The sample targets were repeatedly moved by a programmable stage
controller in order to reduce sample damage due toproton bombardment. Along with the centroid position of 8 Kal,2 from Mo8 2 (8 2 -), that from Na2 80 4
(8 6 +) is shown in Fig. 2. As seen from Fig. 2 (a), the
8 KCXl,2 centroid positions of the aerosol sample were
almost constant during the 1100 s measurement. The
figure indicates that 8 in this aerosol sample is in astable oxidation state of 6+. On the other hand, the 8KCXl,2 centroid positions of the marine sediment sample
varied gradually over time to the higher energy side,i. e. to a higher oxidation number due to oxidation by
air . From extrapolation of the centroid positions, the8 Kal ,2 line shift of the marine sediment sample attime = 0 referring to Mo8 2 was estimated to be +0.44(8.D. ±0.23) channels, indicating that 8 in this sample was originally present as 2- to 0 oxidation state.
To our knowledge , this is the first experiment wherein
the time variations of chemical shifts of X-rays emitted
from practical samples were directly determined.
References
1) K. Maeda et al.: Nucl. lnstrum. Methods Phys. Res. B
134, 418 (1998).
2) K. Maeda et al.: Nucl. lnstrum. Methods Phys. Res. B
150, 124 (1999).
3) K. Maeda et al.: Nucl. lnstrum. Methods Phys. Res. B
136-138, 994 (1998).
4) K. Hasegawa et al.: Int. J. PIXE 8 , 47 (1998); K. Maeda
et al.: RIKEN Accel. Prog. Rep. 33 , 183 (2000).
5) K. Maeda et al.: Nucl. lnstrum. Methods Phys. Res. B
in press.
6) K. Maeda et al.: Int. J. PIXE 10, 47 (2000).

183

7. RIKEN-BNL Collaboration on Spin Physics Program

RIKEN Accel. Prog. Rep. 35 (2002)

Polarized gluon distribution for light hadron pair productions insemi-inclusive pol-DIS
Y.-B. Dong,* 1 T. Morii,*2 and T. Yamanishi*3
To solve the so-called proton spin puzzle, it is crucially important to know how the gluon polarizes ina proton. However, knowledge of the polarized gluon
distribution !::.g is still very limited because it is difficult to directly extract its information from existing
data.
Here, we propose a new formula for clearly extracting the polarized gluon distribution from the light
hadron pair production in pol-DIS. In general, alarge-PT hadron pair is produced via photon-gluon fusion (PGF) and QCD Compton at the lowest orderof QCD. The PGF gives us direct information on
the polarized gluon distribution in the nucleon, while
QCD Compton becomes background to the signal process for extracting the polarized gluon distribution. 1,2)
The cross section of the hadron pair production forsemi-inclusive process, can be calculated based on theparton model with various fragmentation functions.
Then , by using symmetry relations among fragmentation functions and taking an appropriate combination of various hadron pair production processes, we
can possibly remove the contribution of QeD Compton components from the cross section and thus, getclear information of the polarized gluon distribution
from the remaining PGF components. 3,4)
Let us consider the process of l + N ---+ l' + hI + h2 +X in polarized lepton scattering off polarized nucleon
target s, where h I and h2 denote light hadrons in a pair.
We consider the following 4 pairs of produced hadrons
hI with ZI and h2 with Z2,

(i)
(iii)

(7r+, 7r-) ,(7r + , 7r +) ,(ii )(7r - , 7r +) ,(iv)

(7r-,7r - ).

From these pair productions, we can make an interesting combination of cross sections which contains only
the PGF contribution as follows;
d!::.(J"7r+7rI"'-.J+ d!::.(J"7r-7r+ _ d!::.(J"7r+ 7r + _ d!::.(J"7r - 7r -0
19 !::.g(TJ, Q2)d!::.&PGF

x {D(ZI, Q2)D( Z2' Q2) + D( ZI, Q2)D( Z2' Q2)- D( ZI' Q2)D( Z2' Q2) - D( ZI' Q2)D(Z2, Q2)} .
Furthermore, the double spin asymmetry ALL of thiscombination is defined by
*1

*2

*3

Institute of High Energy Physics, Academia Sinica, China
Faculty of Human Development, Kobe University
Department of Managem ent Science, Fukui University ofTechnologys ll2 =18.4GeV, y=O.7S
0.8 1--- -- - - - -- - - - -.=.--=--.0:-._..-. ____l,.L'.~,.---____l~0,6 I--- - -- - -- - - -..

... . ·. . AA~w
7/---r-~---1

0.4 I - - - -- -- ..-...............,....:.:.....-

A--+j

0.2 1 - - - - - ..-"-.... /
~-/
----'
/""'...---I~/ ~ -' ...t~· · ....

z , = 0.25
·0.2 / - - - - - 8, - 40.0 [deg]-0.4 1--_ _ _ z2= 0.40

8 2= 20,0 [deg)-0.6 L -_ __ _ __ __0,01_ __ __----.J

0.1

Fig. 1. Calculated results of the double spin asymmetry forthe process proposed here and /:).g / 9 as a function of rt.

d!::.(J"7r+7r -+ d!::.(J"7r - 7r+ - d!::.(J"7r + 7r + - d!::.(J"7r - 7r -d(J"7r+7r- + d(J"7r - 7r+ - d(J"7r + 7r + - d(J"7r - 7r -!::.g(TJ, Q2)
g(TJ, Q2)d!::.apGF
d&PGF

(1)

We calculate the double spin asymmetry of Eq. (1)at the energy of CO MPASS experiments by using the
AAC 5 ) and GS96 6 ) parametrizations at LO QCD aspolarized parton distribution functions and GRY98 7 )and MRST98 8 ) as unpolarized ones.
At VB =
18.4 GeY, Y = 0.75 , Q2 2: 1 Gey2 and W 2 2: 10 Gey2
with ZI = 0.25 , 81 = 40° , Z2 = 0.40 and 82 = 20° forthe produced pion pair, the calculated ALL are shown
as a function of TJ in Fig. 1. From Fig. 1, one can see abig difference in the behavior of ALL depending on themodels of !::.g / g and hence, we can extract the behavior
of !::.g rather clearly from this analysis.
References
1) A. Bravar, D. von Harrach, and A. Kotzinian: Phys.
Lett. B 421, 349 (1998).
2) A. De Roeck, A. Deshpande, V. W. Hughes, J.
Lichtenstadt, and G. Radel: Eur. Phys. J. C 6 , 121(1999).
3) G. Grispos, A. P. Contogouris, and G. Veropoulos:
Phys. Rev. D 62 , 014023 (2000).
4) Y.-B. Dong, T . Morii, and T. Yamanishi: Phys. Lett. B
520, 99 (2001).
5) Asymmetry Analysis Collaboration, Y . Goto et al.:Phys. Rev. D 62 , 034017 (2000).
6) T. Gehrmann and W. J. Stirling: Phys. Rev. D 53, 6100
(1996).
7) M. Gluck, E. Reya , and A. Vogt: Eur. Phys. J. C 5, 461(1998).
8) A. D. Martin, R. G . Roberts, W. J. Stirling, and R. S.
Thorne: Eur. Phys. J. C 4 , 463 (1998).

185

RIKEN Accel. Prog. Rep. 35 (2002)

Polarized s-Quark distribution in charmed hadron production
K . Sudoh*
Proton spin puzzle is currently one of the most interesting and challenging topics in high-energy spin
physics. The polarized parton distribution function
plays an important role on deep understandings of thespin structure of proton. However, the polarized sea
quark distribution functions remain still poorly clarified.
Recently, the HERMES group has reported 1) that
direct measurements of the strange sea are required to
explain the violation of the Ellis-Jaffe sum rule. However, we do not have sufficient knowledge to determine
the polarized sea quark distribution. Here, I focus on
the polarized sand s quark distribution.
In order to extract the polarized sis quark density, I studied semi-inclusive D *+ I D *- production in
charged current DIS, e+ + p --+ De + D*+ + X ande- + p --+ V e + D *- + X, in unpolarized electronpolarized proton collisions which might be observed in
the forthcoming experiments at THERA or e- RHIC ,where the incident proton is longitudinally polarized.
In naive quark model, D *+ I D *- is dominantly produced by t he fragmentation of cle quark which is produced by sis quark through the t-channel Wexchange
in the leading order. Hence we can expect that measurement of the spin correlation will provide information about the polarized s quark distribution in proton.
In these processes , I calculated the single spin asymmetry AL defined by

0.4 .------,.-- , - - - - - r ------,.- - - , - - - - ,where b.s(x) and b.d(x) are polarized s quark andd quark distribution functions, respectively. Here, I
adopted the AAC 2) and GRSV01 3 ) ("standard scenario") parameterizations for the polarized parton d istribution. D P*+ (z) denotes the unpolarized fragmentation funct ion and I used the Peterson model. 4 )The PT distribution of AL in the D *+ production and t he D *- production at center-of-mass energy
Js = 300 Ge V are shown in F igs . 1 and 2, respectively.
As shown in the figures, AL in the D *- production
largely depends on the model of the polarized parton
distribution function, and significant differences can be
Graduate School of Science and Technology, Kobe University

186

GRSVOI--- AAe0 .3'<!I!.'"----------

0.2

0.1

20

40

60

[GeV]

Fig. 1. Single spin asymmetry in e+ +p --+ De+ D*+ +X as afunction of PT at VS = 300 Ge V. The solid and dashedcurves represent the "standard scenario" of GRSV01
and AAC parametrization , respectively.

0.4 r------r--,-----,------,.--,-----,--vs =300GeVGRSVOI--- AAe

0 .3////----- ---------------

~--~

--

",
",

0.1

20

A ( ) = [dCJ + - dCJ -J I dPT _ db.CJ I dPTL PT - [dCJ+ + dCJ _l/dPT dCJ ldpT .

For instance, in the D*+ production, the spindependent differential cross section generally has a
form,

-

-vs =300 GeV

40

60

[GeV)

Fig. 2. Single spin asymmetry in e- +p --+ Ve+D* - +X as
a function of PT at VS = 300 Ge V. The curves indicate
the same cases as in Fig. 1.

observed in larger PT regions. Therefore , I conclude
that measuring the single spin asymmetry in this process is quite effective not only for testing the model ofthe parton distribution function but also for extracting
the polarized strange sea distribution directly. On theother hand, for D *+ production we cannot determine
the s quark distribution clearly, since the contribution
from the valence d quark is large .
References
1) HERMES Collaboration: Phys. Lett. B 464 , 123(1999) .
2) Asymmetry Analysis Collaboration, Y. Goto et al.:Phys. Rev. D 62 , 034017 (2000).
3) M. Gluck et al.: Phys. Rev. D 63 , 094005 (2001).
4) C . Peterson et al.: Phys. Rev . D 27, 105 (1983) .

RIKEN Accel. Prog. Rep. 35 (2002)

Charmed hadron production and polarized gluon distribution
K. Ohkuma,*1 T. Morii,*2 and S. Oyama*1
The so-called proton spin puzzle is still one of themost challenging topics in nuclear and particle physics.
As is well-known, a proton is not an elementary but
compound particle composed of quarks and gluons.
Therefore, to understand the proton's spin structure,
it is very important to know how quarks and gluonspolarize in the proton.
Many experimental and theoretical studies havebeen done so far to extract information about polarized
distributions of quarks and gluons, and now we haverather good knowledge of t he polarized distributions ofvalence quarks. However, knowledge of t he polarized
gluon distribution 6.g is still very limited because it isquite difficult to directly extract its information fromexisting experimental data. To extract its information,
various processes depending on gluon interactions must
be studied.
Here we propose another process, pp ----? At X, tostudy the polarized gluon distribution in a proton. The
lowest order diagram for this process is gluon-gluon fusion and thus, its cross section is directly proportional
to the gluon distribution in the proton. To get information of 6.g , we study the two-spin correlation of
the target proton and produced At baryon,l) which isdefined as,da++ - da+_ + da __ - da_+da++ + da+_ + da __ + da_+_ d6.a/dTJ= da/dTJ '-AAC;C,,=1
GRSV01 ; C"=1
- - AAC ; C,,=z. _ . GRSVOl; CA,=z0.02.-----.---..----~--""T .....

.....

...

,,

"-

. .................... .

,

-0.04

-0.0~.3-1'-..-..-.._---------..----0.5

Fig. 1. Spin correlation Asymmetry ALL as a function of1] at VB = 500 GeV.

of a charm quark to At is necessary to do numerical calculations. Then, for the unpolarized fragmentation function, we use Peterson fragmentation function,5) D c-->A+ (z) .a) In addition, since we have no data,
at present , about the polarized fragmentation function
for the polarized At production, we take the following
ansatz:
6.D_= Cc-->A+Dc-->A+'c---+ A-+(z)
c
c
c

(1)

where da +_, for example, denotes the spin-dependent
differential cross section with the positive helicity ofthe target proton and the negative helicity of the produced At baryon. TJ means pseudo-rapidity. ALL for
this process will be measured by the forthcoming BNLRHIC experiment . Here, we are interested in the sensit ivity of the observable defined by Eq. (1).
To numerically estimate ALL, we take the GRSV01 2)
and AAC 3 ) parameterization models for the polarized
gluon distribution function and GRV98 4 ) for the unpolarized one. Though both of GSRSV01 and AAC models excellently reproduce the experimental data on t hepolarized structure funct ion of nucleons gl (x), the polarized gluon distributions for those models are quite
different. In other words, the data on polarized structure function of nucleons gl (x) are not enough to distinguish the model of gluon distributions . Since theprocess is semi-inclusive, the fragmentation function*2

0_ ._._._._._._._._.- 0.............

ALL = --~----~-------------­

*1

:.,

:\, :~.:: .. . . ......

Graduate School of Science and Technology, Kobe University
Faculty of Human Development , Kobe University

where C A+ is scale-independent spin transfer coefficient . cIne this analysis, we study two cases : (1)C c--> A+e = 1 (non-relativistic quark model) and (2)Cc-->At = z (J et fragmentation modeI 6 »):.
Numerical results of ALL are shown III FIg. 1. As
shown in Fig. 1, ALL is rather sensitive to the model oft he polarized gluon distribution functions. Therefore,t he process discussed here could provide good information about the distribution of the polarized gluons ina nucleon.
To get better knowledge of 6.g, we need more detailed information about the spin-dependent fragmentation function of a charm quark to At.
References
1) K . Ohkuma et al. : Phys. Lett . B 491, 117 (2000).
2) M. Gluck et al. : Phys . Rev . D 63 , 094005 (2001).
3) Y. Goto et al.: Phys. Rev. D 62 , 034017 (2001).
4) M. Gluck et al.: Eur. Phys. J. C 5 , 461 (1998).
5) C. Peterson et al.: Phys. Rev. D 27, 105 (1983).
6) A. Bartl et al.: Z Phys. C 6 , 335 (1980).

a)z denotes the momentum fract ion from charm quark to At
baryon.

187

RIKEN Accel. Prog. Rep. 35 (2002)

Uncertainty of polarized gluon distribution at RHIC
Y. Goto, M. Hirai, T. Horaguchi,*l H. Kobayashi, S. Kumano,*2 M. Miyama,*3 N. Saito, and T.-A. Shibata*l
In order to investigate nucleon spin structure, wehave parametrized polarized parton distribution functions (Pol-PDFs) by using polarized deep inelastic
scattering (Pol-DIS) experimental data.!) As a next
step, we investigate Pol-PDF uncertainty, which is important to provide more reliable information for predicted physical quantities. It is difficult to estimate
precise uncertainty of a nonlinear function in multidimensional parameter space. However , we could use
a Hessian method for the uncertainty estimation when
the function x2(ai) of the parameter ai is approximated to a parabolic function. The Hessian is obtained
as the second derivative term in the expansion of X 2 (ai)around the minimum point. Then, an error matrix is
given by the inverse matrix of the Hessian. Paramet er errors are obtained by the square roots of diagonal
elements, and non-diagonal elements have correlation
effects with other parameters In this way, uncertainty
of a distribution function F(x) is given by
2[oF(x)] =L -a-CijaF(x) aF(x)
-a- '
ij

a·t

a·J

where Cij is an error matrix and ai denotes a parameter. In the parametrization, the following functional form is used as initial parton distributions at
Q2 = 1 Gey2:~Ji(X) =[OiXVi - Ki(X Vi - XfLi)l!i(X),where i denotes u v , dv , ij, or gluon, Ji (x) is the corresponding unpolarized parton distribution, and Oi , Vi,
Ki, J..Li are free parameters. These parameters are constrained by the positivity condition and flavor SU(3)symmetry, and they are optimized by a X2 analysis. A
Fortran program library of our Pol-PDFs is available
from the AAC home page.2)
In order to use the Hessian method, the X2 (ai) function needs to satisfy the parabolic approximation . In
our analysis, most x2(ai) curves can be approximatedby quadratic functions. However, some parameters are
stopped at a limit which is given by the positivity condition. These parameters control the asymptotic behavior of the Pol-PDFs in the x --+ 1 (or 0) limit , whereexperimental data do not exist. Because these parameters cannot be determined by the Pol-DIS data, weshould fix them to obtain a proper error matrix.
According to our estimation, the polarized valencequark distributions have small uncertainty, so thatthese distributions are determined well by the present
experimental data. On the other hand , the polarized
*1

*2

*3

188

Tokyo Institute of Technology
Saga University
Tokyo Metropolitan University

1 . 5 . - - - - - - - - -- - - -- - - -1

DIS + Fake data
OJ)

0.5

~
0

~- -

~

-0.5

-1
0.001

'
"~~- "DIS only
0.1

0.01

x
Fig. 1. Uncertainty of the polarized gluon distribution at
Q2 = 1 Ge V 2 . The solid curves are obtained by including fake gluon data, and the dotted curves are obtained
only by the DIS data.

antiquark distribution ~ij(x) has large uncertainty inthe small x region . Its small-x behavior seriously affects the quark spin content ~L:. The polarized gluon
distribution ~g(x) has large uncertainty even in the
NLO analysis . These results indicate that it is difficult to determine ~ij(x) and ~g(x) by the Pol-DIS
data. This fact suggests that we should improve ouranalysis by including other measurements from SMC,HERMES, COMPASS, and RHIC.
In particular, prompt photon production at RHIC
is expected to play an important role in determining
the polarized gluon distribution. The spin asymmetry AI' is dominated by the contribution from the
LL
I'gluon Compton process. The statistical error of ALL
is inversely proportional to the square root of the total
number of photon. The statistic error can be estimatedby the event generator PYTHIA under the geometrical acceptance at RHIC . We assume that ~g(x) is
measured near AAC NLO-l, gluon fake data with statistical error are created at VB = 200, 500 Ge Y by fullluminosity for 1 year at RHIC. The gluon uncertainty
is estimated again by including these data. Figure 1
shows the uncertainty of the AAC (NLO-l) gluon distribution and the one with the fake gluon data. The
uncertainty becomes small if the fake gluon data are
included. We can expect to reduce polarized gluon
uncertainty by the prompt photon measurements.
References
1) Y. Goto et al.: Phys. Rev. D 62 , 034017 (2000).
2) http://spin.riken.bnl.gov/aac/RIKEN Accel. Prog. Rep. 35 (2002)

Single-spin asymmetries and soft-gluon poles
Y. Koike*
The interest in the single transverse spin asymmety
AN in the pion production, N(P, B.J..) + N(P')--+

7r(fT ) + X , and the hyperon (typically A) polarization
PA in the unpolarized N N collision, N(P) + N(P') --+A(f T' S-L) + X , resides in the fact that they pro bequark-gluon correlation in the hadrons (higher twist
effect) which is not included in the parton model.
In this note , I will discuss AN and PA in the framework of the collinear factorization. According to thegeneralized QCD factorization theorem, the cross section for AN typically consists of three kinds of twist-3
cross sections,(A)

Ga( Xl , X2) ® qb(X') ® qC-+7r( z ) ® o-~b-+ c'(B)oqa(x) ® Eb(X~ ,X~) ® qC-+7r (z ) ® a~b-+c'

(1)
(2)

(C)

oqa(X) ® qb(X') ® E c-+ 7r (Zl, Z2 ) ® a~b-+c,(3)

and PA likewise receives two contribuliQ[ls,(A')

E a(Xl,X2) ® qb(X') ® Oqc-->A (Z) ® o-!b-+c'

(4)

(C')

qa(x ) ® qb(X') ® Gc-->A(Zl, Z2 ) ® a~b-+c'(5)Here the functions with two variables (momentum fractions) G a(Xl, X2), E a(Xl ,X2 ), E c-+ 7r (Zl,Z2)
Gc-+A(Zl, Z2) are twist-3 quantities: G a and Ea are, respectively, the transversely polarized distribution andthe unpolarized distribution functions in the nucleon.
The functions with a hat, EC-+7r and Gc -+ A are, respectively, the unpolarized fragmentation function forthe pion and the transversely polarized fragmentation
function for A. a, band c stand for the parton's species.
The twist-3 fragmentation functions are definedfromM~ij (Zl' Z2)
= '"'

~

J J

X

d)"

27r

dJ.-L e-i>' /Z l e- i /.L(1 /Z2- 1 / z I)

27r

X (OI~i(O) IH X) (H XlgFa/3(J.-Ln)n/3~j()..n) 10).

(6)M~(zl, Z2) is decomposed to define twist-3 fragmentation funcitons as

M~(Zl' Z2)=- iM/4Pr5S1G}(Zl, Z2)/Z2- iM(S· n)/4 r5 (pa'Tftp - rap)HF(Zl, Z2 )/Z2

(7)

where· .. stands for the twist higher than 3. In Eq. (6),
if one shifts the gluon field strength gpa/3 (J.-Ln )n/3 into
Department of Physics, Niigata University........

........

........ 5........

E F (Z2 , zd, G}R(Zl, Z2) = -G F (Z2, zd, HFR(Zl, Z2) =-HF (Z2, zd . We assume this symmetry property in
our analysis.
With the complete set of the distribution and fragmentation functions up to twist-3, one can derive thecross section formula corresponding to Eqs. (1)- (5).
We follow the previous analyses Refs. 1- 4 and employ
the valence-quark soft-gluon approximation to analyze
the cross section. In this approximation we keep only
the terms with the derivative of the twist-3 functions
such as dEF(x, x)/dx and dEF(z, z )/dz . This approximation should be valid at large x F --+ 1, which probe
the region with large x, small x' and large Z in Eqs. (1)(5) where the relations such as IdEF(x , x)/dxl »EF(x , x) and IdEF( z, z)/dzi » EF(z, z ) hold. The(B) term for AN may cause enhancement in the asymmetry at XF --+ -1 , but it turns out that it is negligible
in all kinematic region because of the smallness of thehard cross section a2 (Ref. 3).
To get a rough idea on the behavior of (C) and(C') contribution to AN and PA, we have performed
a numerical estimate of each term. We have used thesame distribution and fragmentation functions used inRefs. 3 and 4. For the twist-3 functions, we make anextent ion of the ansatz taken in Refs. 1- 4, G}(x , x) =Kaqa(x), Ep(x, x) = K~c5qa( x ) , G}(x, x) = Kaqa(x ),Ep(x, x) = K~qa(x) , and set Ku = -Kd = 0.07,
K~ = Ka = Ka (a = u, d), and K~ = -0.11,
K~ = -0.19. This choice of K~ is simply motivated
to reproduce AN approximately at large XF. The result shows S ) that the (C) term alone can give equally
good fit to the E704 data as the (A) term studied inRef. 1. The (C') contribution also gives rise the rising
behavior of PA at large XF' S )References

M/4pEapnS.L GF(Zl, Z2)/Z2+ M/4rsPrvEvanPEF(Zl,Z2)/Z2 +"' ,the matrix element with ~ (O) and call it M~R(Zl' Z2),
similar decomposition of M~ R defines another fragmentation functions (G FR , G}R' H FR , EFR)' But
these functions are related to (G F, G}, H F, E F) by
the hermiticity. In addition if we assume naive time reversal invariance, these functions become real and obey
the relation GFR( Zl, Z2) = GF(Z2, Zl), EFR(Zl, Z2) =1) J. Qiu and G. Sterman: Phys. Rev. D 59 , 014004(1999) .
2) Y. Kanazawa and Y. Koike: Phys. Lett. B 478, 121(2000) .
3) Y. Kanazawa and Y. Koike: Phys. Lett. B 490, 99(2000).
4) Y. Kanazawa and Y. Koike: Phys. Rev. D 64, 034019(2001).
5) Y. Koike: hep-ph/ 0106260 , Proc. DIS 2001, Bologna,
Italy, 2001-4, to be published.

189

RIKEN Accel. Prog. Rep. 35 (2002)

Partons and QeD in high-energy pp collisions
W. Vogelsang
Current and future dedicated high-energy spin experiments will provide much new information on the
nucleon 's spin-dependent parton distributions. The
question arises of how to consistently determine thevarious densities from the measurements. Such a"global analysis" of the data makes use ofaX2 minimization and will usually require thousands of theory
computations of the cross section for every data point.
The computing time required for a fit easily becomes
excessive, in particular if the partonic hard-scattering
is treated at higher-orders in perturbation theory. Here
we propose a way 1) of implementing efficiently, andwithout approximations, higher-order expressions forany cross section into the fitting procedure.
A general spin-dependent cross section in longitudinally polarized PP collisions , differential in a certain
observable 0 and integrated over experimental bins inother kinematical variables T , can be wntten as

X

dflCJ~
fljb(Xb , f.1) dOdT (xa P A , XbPB, PH, T, f.1),(1)

where the flji are the spin-dependent parton distributions and f.1 the factorization/renormalization scale.
The sum is over all partonic channels ab ---t H X with
their spin-dependent partonic cross section dflCJ~.
We now express the flJi by their Mellin inverses,(2)
One subsequently interchanges integrations and finds
dfl(J"H == L
dO

a,b

1 1
dn

Cn

dm flj::(f.1) flj!:(f.1)

Cm

x flo-~(n , m , 0 , f.1) ,(3)

where the flo-~(n, m , 0 , f.1) do not depend on the parton distribution functions and can be pre-calculated
prior to the fit for a specific set of the two Mellinvariables nand m. They contain all the tediousand time-consuming integrations. The double inverse
Mellin transformation which finally links the parton
distributions with the pre-calculated flo-~ (n, m, 0 , f.1)
of course still needs to be performed in each step of
the fitting procedure, but becomes extremely fast bychoosing the values for n , m on the contours Cn, Cm
simply as the supports for a Gaussian integration.
As a specific example, we consider prompt photon
production, PfJ ---t ,X, at RHIC. We use .JS =200 GeV and consider five values of Pr which will be accessible experimentally. We average over 177 1 < 0.35 in

190. . . . . . . .... ,.(fO,J. O.B (DIS QRty)

(b)

00

g

NLO

·2
,

~I,,= 10 G~V

.....

0.05

0.1

05

Fig. 1. Variations of the polarized gluon densities obtainedin the combined fits , with respect to /::).9 of Ref. 3. See
Ref. 1 for further details.

pseudorapidity and choose f.1 = Pr . The crucial asset ofour method is the speed at which one can calculate thefull hadronic cross section, once the flo-:b(n, m,Pr, f.1)
have been pre-calculated. We found that 1000 evaluations of the full NLO prompt photon cross section takeonly about 10- 15 seconds on a standard workstation.
Figure 1 shows the results for the gluon density
found in a "toy" global analysis,l) of the available dataon polarized deep-inelastic scattering 2) and of fictitious data on prompt photon production at RHIC,
which we project by simply calculating AIL to NLO
using the set of polarized parton distributions of Ref. 3.
Ideally, thanks to the strong sensitivity of the prompt
photon reaction to flg , the gluon density in such a fit
should return close to the function we assumed whencalculating the fictitious prompt photon "data," in theregion of x mainly probed. Indeed, as shown in Fig. 1,
this happens. The shaded band illustrates the deviations of the gluon densities obtained in a large numberof global fits , from the "reference flg" 3) used in generating the pseudo-data. As is expected, the gluon
density is rather tightly constrained in the x-region
dominantly probed by the prompt photon data. Thisis true in particular at x ;:::::: 0.15 , as a result of ourmost precise "data point" for AIL at Pr = 12.5 GeV.
Our analysis clearly underlines the potential and importance of upcoming measurements of AIL at RHIC
for determining flg.
References
1) M. Stratmann and W. Vogelsang: Phys. Rev. D 64,
114007 (2001).

2) for a recent review of the data on polarized deepinelastic scattering, see: E. Hughes and R. Voss: Annu.
Rev. Nucl. Part. Sci. 49, 303 (1999).
3) M. Gliick, E. Reya, M. Stratmann, and W. Vogelsang:
Phys. Rev. D 63 , 094005 (2001).

RIKEN Accel. Prog. Rep. 35 (2002)

Gluon saturation from small-x evolution equation
E . Iancu,*l K. Itakura, and L. l\1cLerran*2
There has been significant progress in recent years
towards understanding the hadron structure in theregime of high parton density at small x, which is theregime relevant for high-energy scattering. As one goesto smaller x with the transverse resolution scale Q2
being fixed , the number of gluons per unit transverse
plane increases rapidly. This is described by a linear
evolution equation such as the BFKL or DLA (double
log approximation) equations. However, at some point ,gluons start to overlap with each other and the "gluon
recombination" is expected to occur. Obviously thisannihilation of gluons leads to slower increase of thegluon density. This is the phenomenon called "gluon
saturation." This regime is governed by a non-linear
evolution equation. The same thing can happen when
we go down to lower transverse momentum scale withx being fixed. The transverse momentum scale Qs(x)when the gluons are piled up on the transverse planeis called the saturation scale.
Study of the saturated gluons is very important for
determining the initial condition of the heavy-ion collisions. To describe physics in the saturation regime,
an effective theory was proposed based on the recognition that the matter can be in a new state, the "Color
Glass Condensate." 1,2) Let us consider a hadron or a
nucleus moving at the speed of light. We separate thedegrees of freedom of this system into two: the large
x and small x partons. The large-x partons (valence
particles) are treated as a color source Pa(X..l) which is
randomly distributed on a two dimensional transverse
plane. Its randomness is governed by a weight function
W[p]. For example, in the very original formulation,l)it was taken to be Gaussian,determined by the source p, the argument of W has
been changed into a. This is the renormalization groupequation which describes the quantum evolution of theColor Glass Condensate.
In order to know how the system evolves as wego to higher energy, we have to solve this non-linear,functional differential equation. With the complicatedx[a], we are forced to perform approximations whichmake the structure simple. 3 ,4) We tried two approximations. One is the mean field approximation (MFA)
in which we replace xla] by its "expectation value"

x[a] --+ XMFA = (x[a])T ==J

Va x[alWT[a],and the other is the random phase approximation(RPA) where we ignore the a dependence of X (which
is a function of Wilson lines of a). In both cases, theweight function becomes Gaussian. Once we determine
it , we can compute the evolution of any physical quantity Oral such as the gluon density (O[a] = F:iF:i ):T (O[a]),= XMFA ,RPA \828~~al), .

MFA leads to a non-linear evolution equation for thegluon density, which reproduces the linear DLA equation at high transverse momentum. Therefore, MFA
is expected to work well at high transverse momentum. In this region, the gluon number density is proportional to l/ki. By considering the case when nonlinear effects becomes non-negligible, we can define thesaturation scale Q;(T) = e CQsT with c being a constantand Q s = a s N c /7r. On the other hand, RPA works
well at low transverse momentum where non-linear effect in the evolution equation is really important. We
found that the gluon number density is proportional
to a;- 1 InT) / ki. This implies that as a result of
the non-linear evolution, the increase of gluon density
becomes slower in low momentum than in high momentum. Therefore, we have shown that the Color
Glass Condensate really derives the gluon saturation
at lower transverse momentum less than the saturation scale, where the transverse size of the gluon islarge and gluons overlap with each other.

Q; (where f..l is the average value of the color charge. On theother hand, small x gluons are considered as classicalfields originated from the color source. This is the basic
picture of the Color Glass Condensate.
"Evolution equation" describes the change of thiseffective theory under the variation of the energy of thesystem. It turned out that within the leading as In x,
the change can be represented as the change of theweight function W[p] .

where T = In l/x, a is a gluon field and X~b.1., y.1. isa complicated function of a. Since the gluon field is*1 Service de Physique Theorique, CE Saclay, France*2

Brookhaven National Laboratory, USA

References
1) L. McLerran and R. Venugopalan: Phys. Rev. D 49,
2233 (1994); Phys. Rev. D 49, 3352 (1994); Phys. Rev.
D 50, 2225 (1994).
2) E. Iancu, A. Leonidov, and L. McLerran: Nucl. Phys.
A 692, 583 (2001); E. Ferreiro, E. Iancu, A. Leonidov,
and L. McLerran: hep-ph/0109115 .
3) E. Iancu and L. McLerran: Phys. Lett. B 510 , 145(2001).
4) E. Iancu, K. Itakura, and L. McLerran: in preparation.

191

RIKEN Accel. Prog. Rep. 35 (2002)

Structural change of Cooper pairs In color superconductivity
H. Abuki,* T. Hatsuda,* and K. Itakura
Because of the asymptotic freedom and the Debye
screening in QCD, deconfined quark matter is expected
to be realized at very high density. This state is nota usual Fermi liquid but a superconducting state dueto the presence of attractive quark-quark interaction.
Many studies have been done so far on this "color
superconductivity" and we have observed that QCD
phase diagram has richer structure than the naive
phase structure with a single quark-hadron transition.
Our knowledge about the color superconductivity is divided into two different approaches. One is the QCDbased analysis that works well at very high density,and the other is somewhat phenomenological description for lower densities based on effective theories withfour Fermi interactions. It has not been clear how the
weak-coupling QCD description at very high densitychanges into the effective description at lower density.
We have studied the two-flavor color superconductivity with an emphasis on the spatial-momentum
dependence of the gap and on the spatial-structureof Cooper pairs. I) The gap function has the following structure (qq) = (>'2T2)(Ch5)~ where C is the
charge conjugation, T2 is the Pauli matrix in the flavor
space, A2 is an anti-symmetric Cell-Mann matrix. Ourmodel includes (i) medium effects of the gluon propagators (Landau damping and Debye screening), (ii)momentum-dependent vertex, and (iii) antiquark-polecontribution. The property (iii) is introduced so that
we can go to lower densities, otherwise the coupling
constant blows up at low momentum scale, which invalidates the calculation. Our model derives the perturbative QCD gap equation at very high density, while
it reproduces the chiral symmetry breaking at lower
density. Therefore , our model can be applied to a very
wide region of the density.
By solving the non-linear equation for the gap function numerically, we found the following results. The
gap at extremely high density has a sharp peak near
the Fermi surface due to the weak-coupling nature of
QCD. This is consistent with the usual BCS picture
in metals. On the other hand, the gap is a smoothfunction of the momentum at lower densities due tostrong color magnetic and electric interactions. Density dependence of the gap function is shown in Fig. l.
The structural change of Cooper pairs can be seen inquantities such as quark correlations in the color superconductor. Especially, we have found that the size of
the Cooper pair becomes comparable to the averaged
inter-quark distance at low densities, while the ratio

Department of Physics , University of Tokyo

192

25~-------,--------~--------,
1- - 2 1\_____ 22/\20_. - 231\
- -

>' 15
~

ll2A

<J+ 105
OL-------~----~~==~~~

o

2

1

3

k/J.L
Fig. 1. 6.+ (k) as a function of momentum (in unit of the
Fermi momentum kF = J.L) at various densities J.L = 2n A
with n = 1, 2,3,12 and A = 400 MeV.

l~~~~~UllL-~LL~~~~~~~
4
6
3

10

10

lOS

10

J.'[MeV]Fig. 2. Ratio of the Cooper pair size ~c and the averageinter quark distance d q as a function of the chemical
potential J.L.

is very large at high density (Fig. 2). These features
are highly contrasted to the standard BCS superconductivity in metals. They rather suggest that quark
matter at lower density could be a "strong coupling"superconductivity where Bose-Einstein condensate will
be a more suitable description.
References
1) H. Abuki , T. Hatsuda, and K. Itakura:
0109013; Phys. Rev. D, to be published.

hep-ph/RIKEN Accel. Prog. Rep. 35 (2002)

Light Goldstone boson and domain walls in the KO-condensed
phase of high density quark matter
D. T. Son*
Recently, many authors l - 3 ) emphasize the likelihoodof kaon condensation in matter at high baryon densities. The crucial observation is that kaons havesmall masses 4) in the color-flavor locked phase (CFL)5)of high-density QCD. A relatively small strangenesschemical potential is thus sufficient to drive kaon condensation. Moreover, it was argued that the mass ofthe strange quark also works in favor of kaon condensation. 2 )In contrast to the conventional charged kaon condensation in nuclear matter, 6) in the CFL phase it is
the neutral kaons which are more likely to condense.
This is due to the inverse mass ordering4) of mesons in
the CFL phase, which makes the neutral kaons lighter
than the charged kaons, at least at very high densities.
The fact that neutral kaons rather than charged kaonscondense might have important astrophysical consequences, since it implies that the kaon-condensed phase
does not require electrons to be electrically neutral,
which is one of the properties of the pure CFL phasewithout kaon condensation. 7 )In a recent paper 8 ) we show that the KO -condensed
phase possesses another distinct feature: it has inits spectrum an extremely light bosonic particle,
whose presence implies the existence of non-topologicalmetastable domain walls.
This feature can be understood easily from symmetry arguments. Like most Bose-Einstein condensates,
the KO condensate spontaneously breaks a global U(l)symmetry: the strangeness. From Goldstone's theorem, one expects a Goldstone boson to appear in the
spectrum. This boson is the U(l)s phase of the condensate, which will be denoted as <p o It might appear
that the KO-condensed phase is a two-component superfluid, the dynamics of which is determined by twoU(l) phases.
A closer examination reveals that the particle arising from the U(l)s breaking is in fact only a pseudoGoldstone boson. Although strangeness is an exact
symmetry of QCD , it is violated by weak processes,
hence the would-be Goldstone boson acquires a mass.
Since symmetry breaking is due entirely to weak interactions, the mass must be a small value proportionall/2

t OGF ·The existence of a light Goldstone boson in the spectrum leads to the appearance of metastable domain
walls. Indeed , at very low energies, the effective Lagrangian for cp must have the formL =~2 [(80 c.p)2 _ U 2(Oicp)2] - V(c.p) ,where f is the decay constant of the boson (which oforder J.L), u is its velocity, and V (cp) comes entirely fromthe explicit violation of strangeness by weak interactions. Due to the nature of cp as a phase variable, V (cp)is required to be a periodic function of cp. Moreover, toleading order in G F, V( cp) rv cos cp. The simplest way
to see that is to express the superfluid ground statewith a definite value of cp as a superposition of stateswith definite values of strangeness,Icp) =

L eiS<f'IS) .

(2)s
To leading order in perturbation theory, the energy
shift of the state I <p) caused by an interaction Hamiltonian Hint is (cp IHint I<p). To order G F, the effective
Hamiltonian of weak interactions has only !:::.S = 1
matrix elements , so V(<p) is proportional to coscp. The
Lagrangian (1) is that of the sine-Gordon theory, which
possesses domain wall solutions interpolating between<p = 0 and <p = 27r.
If baryon number is violated, the superfluid Goldstone mode also acquires a mass. Since the superfluid order parameter is a dibaryon, the mass squareof the superfluid Goldstone boson is proportional tothe amplitudes of the !:::.B = 2 transitions, but not the!:::.B = 1 ones. Using the experimental bound on nfi
oscillations, Tn+-+ii > 10 8 s, we find m < 10- 7 eV. The
thickness of the corresponding domain wall is larger
than about 1 m, and still might be less than the radiusof neutron stars. However, unless the neutron star under consideration rotates very slowly, a domain wallthat thick is unlikely to exist because of the high density of vortices, which are separated by distances oforder 10- 2 cm.
References
1) T. Schafer: Phys. Rev. Lett. 85 , 5531 (2000).
2) P. F. Bedaque and T. Schafer: hep-ph/0105150.
3) D. B. Kaplan and S. Reddy: hep-ph/0107265.
4) D. T. Son and M. A. Stephanov: Phys. Rev. D 61 ,
074012 (2000); Phys. R ev. D 62 , 059902(E) (2000) .
5) D. B. Kaplan and A. E. Nelson: Phys. Lett. B 175 , 57
(1986) .
6) K. Rajagopal and F. Wilczek: Phys. Rev. Lett . 86, 3492
(2001) .
7) K. Rajagopal and F. Wilczek: Phys. Rev. Lett. 86 , 3492
(2001).
8) D. T. Son: hep-ph/0108260.

(1)

Columbia University, USA

193

RIKEN Accel. Prog. Rep . 35 (2002)

Non-perturbative renormalization of pion exchange t
U. van Kolck*
For the last few years Effective Field Theory (EFT)
has emerged as a useful framework in which to describe
few-nucleon dynamics consistently with QCD. The
most general Lagrangian involving low-energy degrees
of freedom (such as low-momentum nucleons) and thesymmetries of QCD (in particular, chiral symmetry) is
constructed, and interactions are ordered according to
an expansion in powers of momenta.
A critical issue has been 1 ) the power counting ofpion interactions in the EFT for momenta Q r-v mn «MQCD r-v mp . Naive dimensional analysis suggeststhat one-pion exchange should be iterated to all orders in the nuclear amplitudes together with two
momentum-independent contact interactions. However, arguments from perturbation theory apparently
indicate t hat this procedure introduces spurious cutoff
dependence, which could be avoided only by treatingpion interactions as perturbative corrections to shortrange effects. On the other hand, it has been recently discovered that the renormalization of a nonperturbative problem can be dramatically different
from the renormalization of its perturbative series. 2 )In the chirallimit (mn ---+ 0) , the relevant interactionis the 1/r 3 tensor potential, so the problem boils down
to the old , unresolved issue of t he renormalization ofThis research was supported in part by a DOE OJI Award.
Un iversity of Arizona, USA

194

singular potentials. Using EFT techniques, we have recently shown that a central l/r n potential can indeed
be renormalized by a short-range interaction containing a single parameter. 3 ) The extension to the relevantcase of pion interactions in the 1 So and 3 Sl- 3 D 1 twonucleon channels has also been carried out. 4) We wereable to show that the two momentum-independent contact parameters can be varied in such a way that theremaining cutoff dependence can be taken care of bysmaller, higher-order operators. Away from the chirallimit , we confirmed perturbative results that impliedthat explicit chiral-symmetry-breaking terms should,
and can, be treated in perturbation theory.4) Ot her
channels are currently under investigation.
References
1) U. van Kolek: Proc. 3rd Int. Conf. on Perspectives in
Hadronic Physics, Nucl. Phys. A, to be published.
2) P. F . Bedaque, H. W . Hammer, and U. van Kolek: Nucl.
Phys. A 646 , 444 (1999).
3) S. R. Beane, P. F. Bedaque, L. Childress, A. Kryjevski,
J. McGuire, and U . van Kolek: Phys. Rev. A 64, 042103(2001) .
4) S. R. Beane, P. F. Bedaque, M. J. Savage, and U. van
Kolek: Nucl. Phys. A 700 , 377 (2002).

RIKEN Accel. Prog. Rep . 35 (2002)

The flow of colored glass in heavy ion collisions
R. Venugopalan*
At high energies, parton densities in nuclei saturate
at a value nl/as(As) » 1, where As (» A QcD ) is
the saturation scale. I) Matter in this state, in a manner
analogous to a spin glass, forms a Color Glass Condensate 2 ) (CGC). In a heavy ion collision, the CGC melts
producing a large number of partons. Since the occupation number of partons is large, classical methods can be used to study the initial conditions forparticle production in heavy ion collisions. 3 ) Krasnitz
and I have developed non-perturbative numerical (lattice) techniques to study the real time gluodynamics
of matter produced in heavy ion collisions. 4 ) Our results depend on two external parameters; these are thesaturation scale As and the radius R of the nucleus .
All dimensionful quantities can therefore be expressedin terms of appropriate powers of the saturation scale
times a non-perturbative function of the dimensionlessproduct AsR.
We have applied these non-perturbative t echniques
to compute several quantities of interest in heavy
ion collisions. These include the energy and number distributions of produced gluons,5) the topological charge generated by fluctuations 6 ) and the momentum anisotropy (usually characterized by the elliptic flow parameter v2) generated in non-central collisions. 7 ) These results were made possible by a coupleof important technical developments in the last year.
The first of these was the extension of the SU(2) gauge
theory results to the physical SU(3) case. 5) The second
was the replacement of the periodic boundary conditions used previously with open boundary conditions. 7 )The latter is essential in computing elliptic and radial
flow. Both of these technical improvements were accomplished in collaboration with Yasushi Nara of the
RIKEN-BNL Research Center.
We now describe our results.
I"V• We find that gluon number distributions can be fit
by the form 1/,rr R2 dN/ dry / d 2k t = in (kt/ A s ) / g2 .
For kt/ As < 3, we find that the form is in =adexp(Jk; +m 2 /Te ff) - 1]-1, namely, a massive Bose- Einstein distribution in two dimensions.
For kt/As > 3, in = a2A:;/ktln(47l'kt/As), whichis the result one expects from perturbative QCD.
We have argued that this scaling of the number
distributions (which manifests itself as mt scalingfor hadrons) is seen in the RHIC data. 8 )• The Yang-Mills equations at high energies areboost invariant. Note that rapidity distributions
in high energy collisions (including RHIC) are

known to be boost invariant. We have demonstrated that the boost invariance of the Yang-Mills
equations forbids sphaleron transitions. 6 ) ChernSimons number and topological charge can be generated only by fluctuations. We have computed
this contribution to the topological charge. It issmall-one unit of topological charge for two unitsof rapidity at RHIC and one unit of topologicalcharge per unit of rapidity at LHC.
• We have very recently computed the second
Fourier component of the momentum anisotropy,
the elliptic flow parameter v2 and studied its dependence on impact parameter as well as its momentum dependence v2(pt). Our conclusion isthat elliptic flow is generated very early in thecollision and that a significant contribution to thisflow is from edge effects. At late times, the sumof the two transverse components of the pressure
equals the energy density confirming that the system has achieved free streaming. 7 )A systematic study of the RHIC data within themodel is still lacking. For instance, it would be very interesting to study two particle (Hanbury-Brown Twiss)correlations since the RHIC data on these disagreewith most models . Further technical improvements
such as fully three dimensional simulations are also
feasible. An interesting problem to investigate further
is the matching of the classical field computations totransport theory in the late stages of the collision.
References
1) L. V. Gribov, E. M. Levin, and M. G. Ryskin: Phys.
Rep. 100, 1 (1983).
2) L. D. McLerran and R. Venugopalan: Phys. Rev. D
49 , 2233 (1994); E. Iancu, A. Leonidov, and L. D.
McLerran; Phys. Lett. B 510, 133 (2001).
3) A. Kovner, L. D. McLerran, and H. Weigert: Phys. Rev .
D 52 , 6231 (1995); Phys. Rev. D 52, 3809 (1995).
4) A. Krasnitz and R. Venugopalan: Phys. Rev. Lett. 86,
1717 (2001); Phys. Rev. Lett. 84, 4309 (2000); Nucl.
Phys. B 557, 237 (1999).
5) A. Krasnitz, Y. Nara, and R. Venugopalan: Phys. Rev.
Lett. 87, 192302 (2001).
6) D. Kharzeev, A. Krasnitz, and R. Venugopalan:arXiv:hep-ph/0109253; submitted to Phys. Lett. B.
7) A. Krasnitz, Y. Nara, and R. Venugopalan: to be submitted to Phys. Rev. Lett.
8) J. Schaffner-Bielich, D. Kharzeev, L. D. McLerran, and
R. Venugopalan: arXiv:nucl-th/0108048; submitted toPhys. Lett . B.

Brookhaven National Laboratory, USA

195

RIKEN Accel. Prog. Rep. 35 (2002)

Soft gluon dynamics at non-zero baryon density
D. Bodeker and M. Laine*
The properties of QCD at a finite temperature T
and chemical potential j1 play an important role for thephysics of the early universe, heavy ion collision experiments , and neutron stars. Despite the presence of apotentially large scale, say T » AQCD , QCD however
remains sensitive to non-perturbative infrared physics.
Various effective theories may be derived in perturbation theory, but the rich phenomena encoded in them
may have to be addressed non-perturbatively.
Quite generically, effective theories tend to possess
extra symmetries, only broken by higher dimensional
operators. A familiar example is weak interaction induced strangeness violation in zero temperature QCD.
Similar phenomena take place also in high temperature physics. For instance, the dimensionally reduced
effective field theory describing the thermodynamics ofthe electroweak sector of the Standard Model has extra symmetries: parity (P) and charge conjugation (C)are only broken by higher dimensional operators. 1)
In QCD, perturbative interactions break neither P
nor C, but the latter can be broken by the thermal
ensemble, if there is a finite baryon density (/-L "# 0).
Indeed , in the dimensionally reduced effective field theory for the thermodynamics of QCD , there is again a
new C-odd operator, of higher order than the leading
C even operator. 2)
Here we will discuss the same phenomenon for dynamical quantities, that is in real time. We show thata purely gluonic C-odd operator is induced by quark
loops. Thus C-odd observables may be directly sensitive to non-perturbative bosonic dynamics.
The environment in which we may envisage ourresults to have significance is mainly that of heavy
ion collision experiments. Precision studies of dimensional reduction show that effective theories of the typeconsidered may be quantitatively accurate down toT rv 2Tc . At the same time, the infrared dynamics
described by the effective theories is completely nonperturbative at any reasonable t emperature. Directfour-dimensional (4d) lattice simulations are not available either for real time quantities (for a review, see
Ref. 3). Thus effective theories appear presently to be
the only way of studying quantitatively some interesting non-perturbative processes for phenomenologically
relevant temperatures.
We have calculated the I-loop contribution of hard
(p rv T) quarks to the effective action for soft gluons
to all orders in the gluon field and to first subleading
order in the high temperature expansion,4)fC -odd= - - 12 g 3 j1Nf
27r

J 1
d4 x

,

v

CERN Theory Division , Switzerland196

Tr( v .1D va PaM ) (v.1D Vf3 Pf3M) (v.1D DO" v.1D v' F yO" ).
(1)
Here P MV = P:vTa is the gluon field strength tensor,
DM is the covariant derivative, and v M = (1, v). The
integral is over the orientations of the unit vector v
which represents the 3-velocity of hard quarks.
N ow consider the kinetic equations--

v . af - gv

Mpa afa
Mi api '(v. D)ab fb = fldabcvM p b afc + LvM pa 8f.
2
Mt apt2N
Mt apt(2)

These are solved in expansion in Ikl/T were k is a typical wave vector of the gauge fields. At lowest orderf(p) = NnFermi(P±j1) for quarks and antiquarks, respectively. Then the equation j = 6T / 8A is integrated
for the current(3)
where the sum runs over all quark species i . At first
non-trivial order one obtains the well known hard thermal loop effective action. We found that at the nextorder f is indeed equal to f C-odd in Eq. (1). This opens
the possibility to use Eq. (2) for simulating the softgauge field dynamics to account for C-odd effects (forlattice simulations of the hard thermal loop effective
theory see Ref. 5).
As a further check that Eq. (2) reproduces thephysics of the soft gauge fields we have considered thestatic field limit of Eq. (1). This is non-trivial considering the non-local nature of f C-odd. One finds(SC-odd)stat ic =

g3Nf

3

-j1 37r 2 TrAo·(4)

This is precisely the leading C-odd contribution in dimensionally reduced action. 2 ) A word of caution is inorder, however. Very recently it was found that at thenext order in the high temperature expansion Eq. (2)does not give the correct static limit. 6 )References
1) K. Kajantie, M. Laine, K. Rummukainen, and M.
Shaposhnikov: Phys. Lett. B 423 , 137 (1998).
2) A. Hart, M. Laine, and O. Philipsen: Nuel. Phys. B
586, 443 (2000) .
3) D. Bodeker: Nuel. Phys. B (Proe. Suppl.) 94, 61 (2001).
4) D. Bodeker and M. Laine: J. High Energy Phys. 0109 ,
029 (2001).
5) D. Bodeker, G. D. Moore, and K. Rummukainen: Phys.
Rev. D 61 , 056003 (2000) .
6) M. Laine and C. Manuel: arXiv:hep-ph/0111113.

RIKEN Accel. Prog. Rep. 35 (2002)

Neutrino cross sections and future observations ofultrahigh-energy cosmic rays
A. Kusenko*
Detection of ultrahigh-energy (UHE) neutrinos is
one of the important challenges of the next generation of cosmic ray detectors. Their discovery will markthe advent of UHE neutrino astronomy, allowing the
mapping on the sky of the most energetic, and most
distant, sources in the Universe. In addition, detectionof UHE neutrinos may help resolve the puzzle of cosmic rays with energies beyond the Greisen-ZatsepinKuzmin cutoffl) by validating Z-bursts,2) topologicaldefects ,3) superheavy relic particles,4) etc.
Several approved and proposed experiments haveadopted a strategy for detection of UHE neutrinos byobservation of the nearly horizontal air showers (HAS)in the Earth's atmosphere resulting from v-air interactions. The expected rates are proportional to the neutrino cross section. Calculations of this cross section
at 10 20 eV necessarily use an extrapolation of parton
distribution functions and Standard Model (SM) parameters far beyond the reach of experimental data.
The uncertainty in the cross section allows for smaller
values of the neutrino-nucleon cross section. The corresponding rates of HAS are proportional to this crosssection and may also be lower. Hence, a lower valueof the corss section could compromise the main detection signal that has been proposed for UHE neutrino
experiments.
It was shown, however, that regardless of possible
theoretical uncertainties in the cross section, the future experiments can observe the UHE neutrinos ifthey adopt a new strategy.5) In fact, a smaller crosssection, for which the rate of HAS is low, would offera double advantage for the planned experiments because, in addition to doing neutrino astronomy, future
detectors can also measure the neutrino cross section atenergies far beyond those achievable in collider experiments. This study was motivated in part by a recent
analysis of upward events by Feng et al. 6 )In addition to HAS, proposed cosmic ray experiments can also observe up-going charged muon and tau
leptons (UCL) produced by neutrinos interacting justbelow the surface of the Earth, and the up-going air
showers (UAS) initiated by these leptons. A smaller
value of this cross section reduces the shadowing of
UHE neutrinos by the Earth. Therefore, the neutrino
angles with respect to horizon need not be so "skimming." More importantly, the expected rate of UCLs
and UASs may (1) be larger, and (2) depend on the
cross section.

-3

10

-4

10

UAS
2

-5

10

HAS

-33

10

-32

10

-3\

10

(J,Crrf

Fig. 1. The air shower probability per incident tau neutrino as a function of the neutrino cross section. Theenergy threshold for detection of U AS was assumed
18
Eth = 10eV for curve 1 and 10 19 eV fqr curve 2.

The relative rates of horizontal and up-going events
are shown in Fig. 1.
In addition, the neutrino cross section may be determinable from the angular distribution of UCL events
alone, independent of the neutrino flux. One expects the angular distribution of UCL to peak nearcos 8peak rv Av /2R(JJ, where Av is the mean freepath of neutrino in the Earth. This implies CJvN rv(2 (p) R(JJ cos 8p eak )-1.
References
1) K. Greisen: Phys. Rev. Lett. 16, 748 (1966); G. T.
Zatsepin and V. A. Kuzmin: Pisma Zh. Eksp. Teor.
Fiz. 4, 114 (1966).
2) T. Weiler: Phys. Rev. Lett. 49, 234 (1982); Astropart.
Phys. 11 , 303 (1999).
3) For reviews, see, e.g., A. Vilenkin and E. P. S. Shellard:
Cosmic Strings and Other Topological Defects (Cambridge University Press, Cambridge, 1994); M. B.
Hindmarsh and T. W. B. Kibble: Rep. Prog. Phys. 58 ,
477 (1995); V. A. Kuzmin and I. I. Tkachev: Phys.
Rept. 320, 199 (1999).
4) V. Berezinsky, M. Kachelriess, and A. Vilenkin: Phys.
Rev. Lett. 79, 4302 (1997); V. A. Kuzmin and V. A.
Rubakov: Phys. Atom. Nucl. 61 , 1028 (1998); M. Birkel
and S. Sarkar: Astropart. Phys. 9 , 297 (1998); P.
Blasi: Phys. Rev . D 60, 023514 (1999); S. Sarkar: hepph/0005256.
5) A. Kusenko and T. Weiler: arXiv:hep-ph/0106071.
6) J. L. Feng, P. Fisher, F. Wilczek, and T. M. Yu:ar Xiv:hep-ph/Ol 05067.

Department of Physics and Astronomy, University of California , Los Angels, USA

197

RIKEN Accel. Prog. Rep. 35 (2002)

Scaling relations for the transverse mass spectra
and the color glass condensate
J. Schaffner-Bielich,*l D. Kharzeev,*2 L. McLerran,*2 and R. Venugopalan*2
In recent works,1,2) we demonstrated that the transverse mass distribution of produced hadrons as recently measured at the Relativistic Heavy-Ion Collider(RHIC)3) can be described by generalized scaling relations. These relations are motivated from scaling
properties of the color glass condensate, the initial saturated gluon state which scales as 4 )10'

PHENIX

min. bias

(1)

10-4

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

ml (GeV)

Here, f9 is a universal, dimensionless function for the
produced gluons which depends only on the ratio of thetransverse momentum Pt and the saturation momentum Qs. Different energies or scales are described by
the same function with a correspondingly changed saturation momentum. This picture has been successfully
applied for the charged multiplicity data at RHIC. 5 )Therefore, we argue that a corresponding relation of
the form~ d:;~t = a)p,)"h .

f ( :' ) ,Fig. 1. Minimum bias data rescaled as a function of transverse mass (preliminary data taken from PHENIX collaboration 3) ).

.0-5%.5-15%. 15-30%430-60%60-92%

10'

(2)
1[-

holds for the recently measured transverse mass spectra at RHIC. Here, the function f stands for an universal, dimensionless function. The parameters are (J for
the transverse area, and Ps for the hadronic saturation
momentum which are changing according to centrality,
system size and bombarding energy. The saturation
momentum Ps should follow the same dependence as
one expects for the corresponding saturation momentum for gluons, Qs.
The predictions of the above relation are twofold:
first, it predicts that the transverse mass spectra canbe described by one universal function which depends
only on the transverse mass mt and the saturation momentum Ps. Corrections to that behavior are due tothe parameter ""h which controls the particle abundance for high Pt and is of order one. Indeed , wehave checked that this generalized scaling works fordescribing the recent preliminary data from RHIC 2(see Fig. 1). Second, the relation predicts that thetransverse mass spectra for different centralities canbe rescaled into one universal curve by properly readjusting the transverse area and the saturation momentum Ps. Also this remarkable feature was confirmed byus using the recent preliminary data from RHIC 2 (seeFig. 2).
We extracted the parameters (J / CXs and Ps from thedata as a function of centrality. It turns out that
*1
*2

198

Columbia University, USA
Brookhaven National Laboratory, USA

andp

10-3
PHENIX

10-4

•

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

ml(GeV)

Fig. 2. Spectra for different centralities rescaled as a function of transverse mass (preliminary data taken fromPHENIX collaboration 3)).

both parameters are changing as expected, (J / CXs (Ps) rv
1 3
2/ 3 II
N part.
For companson,.
/
N partnps / Jl. an d P2s rv c + c,
the saturation momentum for gluons is expected tochange as
rv N~~:t.
The additional constant c in
the centrality dependence of Ps stands for the finite
mean transverse momentum as measured in PP and pp
collisions.

Q;

References
1) L. McLerran and J. Schaffner-Bielich: Phys. Lett. B
514, 29 (2001).
2) J. Schaffner-Bielich, D. Kharzeev , L. McLerran, and R.
Venugopalan: nucl-th/0108048 .
3) J. Velkovska, PHENIX Collaboration: nucl-ex/0105012 ;W. A. Zajc et al., PHENIX Collaboration: nucl-ex/
0106001.
4) A. Krasnitz and R. Venugopalan: Phys. Rev. Lett. 86,
1717 (2001); Phys. Rev. Lett. 84, 4309 (2000).
5) D. Kharzeev and M. Nardi: Phys. Lett. B 507, 121(2001); D. Kharzeev and E. Levin: nucl-th/0108006.

RIKEN Accel. Prog. Rep. 35 (2002)

Hadronic signals of QGP
S. Jeon*At temperatures exceeding AQCD , the quarks andgluons bound inside hadrons are supposed to be freed
and form a Quark-Gluon Plasma (QGP). This 'new'state of matter was in existence briefly in the very
early universe, but few microseconds after big-bang,
the temperature became low enough to bind them into
ordinary hadrons we see today.
One of the expressed goals of the heavy ion collision experiments is to re-create this state of matterand study it. At the Relativistic Heavy Ion Collider,
we are quite certain that the collision energy is highenough to produce such a state. The question is then,once created, how do we observe it? The answer is
not simple because even though we create liberated
quarks and gluons, ultimately what we observe in our
detectors are the ordinary mesons and baryons. If a
QGP was indeed created, it must leave foot-marks inthe properties of the hadronic system created from the
QGP. In this brief report, I report my research on answering this question, namely, how to see the QGP in
the fluctuations of hadrons.
One of the distinguishing properties about quarks
from hadrons is that the quarks carry fractionalcharges. This difference clearly shows up in the charge
fluctuation per charged degree of freedomof grand-canonical ensemble is not applicable. Rather,
one should apply the concept of micro-canonical ensemble where the conserved quantites (except the energy and momentum) are fixed absolutely instead ofon average. As the system size gets larger, this difference disappears. However, for small systems, the twoensembles give a markedly different results. In a paper written by V. Koch, K. Redlich, X.-N. Wang andthe present author,2) we derived a master equation for
production of particle pairs under a strict conservation
law. An important result is that by measuring the second factorial moment of such pairs, for instance kaons,
we can determine if the system started out with anover-population or under-population.
While V. Koch and the author advocated the charge
fluctuation as the QGP signal, Scott Pratt has advocated the changes in the balance functions as thesignal. Recently, Scott and the author joined forces
and clarified the relationship between these two approaches. 3 ) In terms of correlation functions , a chargebalance function can be defined in the following way:(1)

where Gij is the correlation of the species i and j as afunction of rapidity differences. Y is the size of the rapidi ty bin in which the balance function is being calculated. The relationship between the charge fluctuationand the balance function is simply

In a pion gas, the charge fluctuation simply equals
the pion number fluctuation since the pions carry unit
charges. If one assumes a thermal equilibrium, then
the number fluctuation in turn is approximately thesame as the average number. Hence in this case 'D ~ 1.
In a QGP, a u quark carries a charge of 2/3 and a dquark carries a charge of -1/3. Hence the charge fluctuation is (1/3)2 + (2/3)2 = 5/9 of the quark number
fluctuation. This alone would reduce the charge fluctuation by almost a factor of 2 compared to the pioncase. Furthermore, the final state charged degree of
freedom include contribution from the neutral gluons.
Combining the two effects, we can conclude that if a
QGP is formed, then the hadronic system arising fromit should have 'DQGP = 1/3 - 1/4 which is a factor of
3 to 4 smaller compared to that of the pion gas. 1)
When the system created by a collision is small, suchas the one created in a peripheral collision, the concept

1 {dn+dn_
B(~yIY) = 2 dy G++(~y) + dy G__ (~y)_ (d;y+ + d;y_) C+_ (L'.y)} .

(2)

(3)
in the limit (Nch) » (Q). The information coded in
the balance function is therefore more local whereas
the charge fluctuation encodes more global information.
References
1) S. Jeon and V. Koch: Phys. Rev. Lett. 85 , 2076 (2000).
2) S. Jean , V. Koch, K. Redlich, and X. N. Wang: Nucl.
Phys. A 697, 546 (2002).
3) S. Jean and S. Pratt: arXiv:hep-phjOl10043, to be published in Phys. Rev. C.

McGill University, USA

199

RIKEN Accel. Prog. Rep. 35 (2002)

Kaon condensation in QeD
T. Schafer*
Quark matter at very high baryon density is expected to behave as a color superconductor. 1 ,2) Color
superconductivity implies that the local gauge symmetry is broken by a Higgs mechanism. There is a gap in
the fermion excitation spectrum and gauge fields arescreened by the Meissner effect. In addition to that,color superconductivity can lead to the breakdown ofglobal symmetries, such as the U(l) of baryon number or the SU(Nf)L x SU(Nf)R chiral symmetry. The
symmetry breaking pattern depends on the number ofcolors N c , the number of flavors Nf, and the quark
masses.
A particularly symmetric phase is the color-flavorlocked (CFL) phase of three flavor quark matter. This
phase is believed to be the true ground state of strange
quark matter at very large density. The CFL phase ischaracterized by the order parameter

masses cannot be neglected. We have studied thisproblem using the effective chiral theory of the CFL
phase. 3 ) The ground state and its low energy excitations can be described by a chiral field ~ = Xyt which
depends on the relative flavor direction of the left andright handed diquark condensates X and y . If thequark masses are equal we find that the ground statecorresponds to ~ = 1. However, if the strange quark
mass ms exceeds some critical value then it becomesenergetically favorable to rotate ~ in the neutral or
charged kaon direction. At very large baryon density
the critical ms can be computed in perturbative QCD.
We find mslcrit = 3.03.m~/3 1::::. 2 / 3 . This result suggeststhat for values of the strange quark mass and the gap
that are relevant to compact stars CFL matter is likely
to support a kaon condensate.
References

In the CFL phase the chiral SU(3)L x SU(3)R symmetry is broken to SU(3)v , which is identical to the chiral symmetry breaking pattern of QCD at zero baryon
density.
At baryon densities relevant to astrophysical objects
distortions of the pure CFL state due to non-zero quark

Department of Physics, State University of New York, Stony
Brook, USA2001) D. Bailin and A. Love: Phys. Rep. 107, 325 (1984).
2) R . Rapp , T. Schafer, E. V. Shuryak, and M. Velkovsky:
Phys. Rev. Lett. 81, 53 (1998) ; M. Alford, K.
Rajagopal, and F. Wilczek; Phys. Lett. B 422 , 247(1998).
3) P . F . Bedaque and T. SchaJer: hep-ph/0105150.

RIKEN Accel. Prog. Rep. 35 (2002)

Novel phenomena in high-density QeD
M. A. Stephanov*This paper is a summary of Refs. 1 and 2. The aim of
this work is to understand the physics of QCD at large
baryon density. This regime is of relevance primarily
to the neutron star physics, but may also shed lighton properties of high-density QCD relevant to heavyion collision experiements. Theoretically, the regime ofvery, asymptotically, large baryon chemical potential j.lis attractive because the asymptotic freedom of QeD
allows controllable calculations.
In this work we describe the physics of the lowest excitations of the high density QCD. The number of lightquark flavors Nj turns out to playa crucial role. The
simplest case is N f = 2 where up and down quarks aremassless and other quarks are neglected . This model isa rather good approximation to realistic quark matterat moderate densities, such as in the neutron star interiors. The ground state of this model at high baryon
densities is the two-flavor color-superconducting (2SC)
state, characterized by the condensation of diquark
Cooper pairs. These pairs are antisymmetric in spin
(CY., f3), flavor (i, j) and color (a, b) indices :qjb)* = E EijEabc xc
(q ia
La L~
a~
,

We also find that, at scales much shorter than the confinement radius, the dynamics of the SU(2) gluons issimilar to electrodynamics in a dielectric medium witha large refraction index
g2j.l2

E=I+187r2~2'This can be interpreted as a consequence of the factthat the Cooper pairs have large size (of order 1/ ~ )and so are easy to polarize.
In perturbation theory, there is a degeneracy of theground state with respect to the relative U(I) phasebetween x a and ya . This is due to the U(l)A symmetry of the QCD Lagrangian at the classical level. The
U (1) A symmetry is spontaneously broken by the colorsuperconducting condensate. Since this is a global
symmetry, its breaking gives rise to a Goldstone boson- pseudoscalar TJ. Due to the well-known anomalous
breaking of the U(l)A symmetry the TJ boson acquiresa small mass, which is much smaller than ~ .

whereia qjb )* = E Eij Eabc yc
(q Ra
R~
a~
.

The condensates XC and yc are complex color 3vectors . . In the ground state, XC and yc are aligned
along the same direction in the color space, and they
break the color SU(3)c group down to SU(2)c. Thus,
five of the original eight QCD gluons acquire "masses"
by the Meissner effect, similar to the Higgs mechanism.
The remaining three gluons are massless (perturbatively). Due to the pairing, the spectrum of quarks
carrying SU(2) color charge has a gap ~where g(j.l) is the gauge coupling at the scale j.l, and b
is some numerical constant.
In order to understand the physics below the energy
scale ~ we must examine the pure gluodynamics inthe remaining unbroken SU(2) sector. We find thatthe process of high-density "deconfinement" is quite
nontrivial in this case: the quarks are always confined(assuming that SU(2) Yang-Mills theory confines), but,the confinement radius, Rc == 1/ AQCD grows exponentially with increasing density:a = 5 x 10 4 ( In A:

CD )

7(

A~CD )29/3

The effective action for the TJ field admits a classicalconfiguration corresponding to a domain wall with thewidth of the order of l/mTJ. The tension of the domain
wall isThis wall is metastable. The decay proceeds throughnucleation of a critical hole in the wall, similarly to the
decay of a false vacuum. A more detailed and quantitative discussion of the wall's decay can be found in
Ref. 2. Here we note that the wall's lifetime is exponentially large at large j.l .
Although we discussed 2-flavor QCD, a light pseudoscalar and domain walls also occur in QCD with 3
light flavors. These phenomena as well as asymptotic
deconfinement are present in QCD at finite isospin density, a theory which can be studied by a lattice Monte
Carlo simulation at any value of isospin chemical potential.
References

We term this phenomenon asymptotic deconfinement.

1) D. H. Rischke, D . T. Son, and M. A. Stephanov: Phys.
Rev. Lett . 87, 062001 (2001).
2) D. T. Son, M. A. Stephanov, and A. R. Zhitnitsky:
Phys. Rev. Lett. 8 6, 3955 (2001) .

University of Illinois at Chicago, USA

201

RIKEN Accel. Prog. Rep. 35 (2002)

Hydrodynamic analysis of elliptic flow at RHIc t
T. Hirano*
Nucleus-nucleus collisions at the Relativistic Heavy
Ion Collider (RHIC) give us an opportunity to study
a new state of deconfined nuclear matter, the quarkgluon plasma (QGP). The main goals in the physics ofrelativistic heavy-ion collisions are not only the discovery of the QG P, but also the investigation of thermodynamical aspects of its new phase, i.e., the equationof state (EOS), the order of phase transition between
the QGP phase and the hadron phase, or the criticaltemperature. It is very important to check whether
the thermalization of the nuclear matter produced atthe very early stage of collisions is really achieved, before discussing the thermodynamics of the QGP. Elliptic flow in non-central collisions is suited for this purpose.I) If produced particles frequently rescatter witheach other , we naively expect that thermalization of
the system is achieved and that the large pressure isbuilt in the reaction zone. The pressure produces themomentum anisotropy of observed particles from thespatial deformation in the transverse plane. The coefficients of second harmonics in the azimuthal distribution, not only its magnitude V2 but also its transverse momentum dependence V2(Pt) and its centrality
dependence V2 (b) , seem to be good indicators for thermalization of nuclear matter. Hydrodynamic simulations , in which full local thermalization is assumed,
give us excellent agreement with the first result ofV2(Pt) from Au+Au 130 A GeV collisions at the RHIC
up to Pt rv 1.5 GeV Ie near midrapidity.2) Their results are based on a (2+1)-dimensional hydrodynamic
model with the Bjorken's scaling solution. One cannot , however, discuss the rapidity dependence of observables by exploiting the Bjorken's model. Since thismodel is assumed to give a good description of spacetime evolution of nuclear matter near the midrapidity
region, the agreement between the model calculationand experimental data means that early thermalization
at the RHIC is achieved at least only at midrapidity.
We investigate how far from midrapidity thermalization in the early stage is achieved through comparisonof the pseudorapidity dependence of elliptic flow from agenuine three-dimensional hydrodynamic model 3 ) with

Condensed from the article in Phys. Rev. C 65, 011901(2002).
Physics Department , University of Tokyo

202

0.08
preliminary PHOBOS data ~ICAIe B - - .

0.07
0.06
0.05
;:ot'O.04

0.03

""

"

!

0.02

!!

0.01
0_ 6

!

-4

-2

o

2

4

6

11

Fig. 1. Pseudorapidity dependence of elliptic flow V2(T)).

experimental data recently measured by the PHOBOS
Collaboration. 4 )Figure 1 shows the pseudorapidity dependence of
elliptic flow V2 (TJ) for charged particles. Preliminary
experimental data is obtained by the PHOBOS Collaboration. 4 ) Two lines correspond to two different
parametrization for initial energy density which havealready been so tuned as to reproduce single particle
spectra of hadrons, such as pseudorapidity distribution
and transverse momentum distribution in Au + Au 130
A GeV collisions. 3 ) Although we reproduce the pseudorapidity distribution of charged particles in whole rapidity region, our results for V2 (TJ) are consistent withthe experimental data only near mid (pseudo )rapidity.
This suggests thermalization of the system producedin Au + Au collisions at RHIC is achieved only near
midrapidity. On the other hand , only partial thermalization is achieved in forward and backward rapidity
regions .
References
1) J.-Y. Ollitrault: Phys. Rev. D 46 , 229 (1992).
2) P. F. Kolb, P. Huovinen, U. Heinz, and H. Heiselberg:
Phys. Lett. B 500 , 232 (2001).
3) T. Hirano: Phys. Rev. C 65 , 011901 (2002).
4) PHOBOS Collaboration, 1. Park et al.: Nucl. Phys. A
698, 564 (2002).

RIKEN Accel. Prog. Rep . 35 (2002)

Initial coherent gluon production from the color glass condensate
in relativistic nuclear collisions
A. Krasnitz,* l Y. Nara,*2 and R. Venugopalan*2
The Relativistic Heavy Ion Collider (RHIC) is currently colliding beams of gold nuclei at t he highest center of mass energies per nucleon, J S N N = 200 Ge V.
The goal of these experiments is to explore strongly interacting matter, in particular the quark gluon plasma(QGP) predicted by lattice QCD.
The possible formation and dynamics of the QGP
depends crucially on the initial conditions, namely, thedistribution of partons in each of the nuclei before thecollision. At high energies and for large nuclei, parton
distributions saturate and form a color glass condensate (CGC).l)
The early stages of a relativistic heavy-ion collision
are examined in the framework of an effective classicalYang-Mills theory in the transverse plane. We compute the initial energy and number distributions, perunit rapidity, at mid-rapidity, of gluons produced inhigh energy heavy ion collisions. 2- 4 ) In the theory, thescale As and the size of the nucleus R are the only physically relevant dimensional parameters. 2- 4 ) In Fig. 1,
we plot the normalized gluon transverse momentum
distributions versus kT / As with the value AsR = 83.7,
together with SU(2) result. Clearly, we see that thenormalized result for SU(3) is suppressed relative to
the SU(2) result in the low momentum region. At largetransverse momentum, we see that the distributions
scale exactly as
1, t he number of color degrees
of freedom. This is as expected since at large trans-

N; -0.07.---- - - - - - - - - - - - - - .

A s R=83.7

SU3
"SU2
-fit
a

*
•

L.f

A.R=74.2
A.R=37£
A.R:::18.5• STAR charged

t'

i

• i

1

0.1

0.2

0.3

0.4

0.5

0.6

0.7

O.B

0.9

"ctlnm••Fig. 2. Calculated results with AsR = 74 (diamonds), 37(triangles) , and 18.5 (squares) are compared to theSTAR data6 ) (circles) on the centrality dependence ofthe elliptic flow parameter V2 defined by the second
Fourier coefficient.

verse momentum, the modes are nearly t hose of noninteracting harmonic oscillators. At smaller momenta,
the suppression is due to non-linearities, whose effects,
we have confirmed, are greater for larger values of theeffective coupling AsR.
We calculate anisotropy in momentum space in
Fig. 2 by solving classical SU(2) Yang-Mills equationsof motion on the lattice. It is shown that initial gluons
are produced with anisotropy in momentum space inthe typical time scale T '" 0.3 fm/c. 5 ) This anisotropy
in the momentum flow originates from the spatial
anisotropy of the strongly interacting gauge field in
the almond-shape overlap region of a collision.
References

0.02
0.01
00

0.2

0.4 Ir I

0.6

0.8"'l"AS

Fig. 1. Transverse momentum distribution of gluons perunit area, normalized to the color degrees of freedom,n (kr) = dnd 2 k t /(N; - 1) as a function of AsR for
SU(3) (squares) and SU(2) (diamonds). Solid lines correspond to the fit with the Bose-Einstein form.

1) L. McLerran and R. Venugopalan : Phys. Rev. D 49,
2233 (1994); Phys. Rev. D 49, 3352 (1994); Phys. Rev.
D 50 , 2225 (1994).
2) A . Krasnitz and R. Venugopalan: Phys. Rev. Lett. 84,4309 (2000).
3) A . Krasnitz and R. Venugopalan: Phys. Rev. Lett . 86 ,
1717 (2001).
4) A. Krasnitz, Y. Nara, and R. Venugopalan : Phys. Rev.
Lett . 87, 192302 (2001) .
5) A. Krasnitz, Y . Nara, and R. Venugopalan: in preparation.
6) STAR Collaboration: Phys. Rev. Lett. 86 , 402 (2000).

* 1 CENTRA and Faculdade de Ciencias e Tecnologia, U niversidade do Algarve, Campus de Gambelas, Portugal*2 Physics Department , Brookhaven National Laboratory,
USA

203

RIKEN Accel. Prog. Rep. 35 (2002)

Probing the QGP equation of state with two-particle
interferometry
S. A. Bass, S. SOff,*l D. H. Hardtke,*2 and S. Y. Panitkin*2
Bose-Einstein correlations in multiparticle production processes l ) provide valuable information on thespace-time dynamics of fundamental interactions. 2) In
particular, lattice QeD calculations predict the occurrence of a phase transition at high temperature.
A first order phase transition leads to a prolonged
hadronization time as compared to a cross-over or ideal
hadron gas with no phase transition, and has been related to unusually large Hanbury-Brown-Twiss (HBT)
radii. 3 ) The phase of coexisting hadrons and QGP reduces the "explosivity" of the high-density matter before hadronization , extending the emission duration ofpions. 3 ) This phenomenon should then depend on the
hadronization (critical) temperature Tc and the latent
heat of the transition.
In our study, we have calculated the Gaussian radius parameters of the pion-emitting source in highenergy heavy ion collisions,4) assuming a first orderphase transition from a thermalized Quark-GluonPlasma (QGP) to a gas of hadrons. Our calculations
have been performed in the framework of a hybrid
macro/micro transport approach , utilizing hydrodynamics for the early, dense, QGP phase of the reaction and microscopic transport theory for the later,
dilute, hadronic reaction phase. 5 ) Such a model leads
to a very long-lived dissipative hadronic rescattering
phase which dominates the properties of the two-pioncorrelation functions. Figure 1 shows that if the dissipative hadronic phase is taken into account, the radii
as well as the Rout! Rsid e ratio are found to depend only
weakly on the thermalization time Ti, the critical temperature Tc (and thus the latent heat) , and the specificentropy of the QGP. The dissipative hadronic stage
enforces large variations of the pion emission times
2 ••

•••

2.2

2.0

U

2.4
2.2
2.0

• RJR. T.I60RHlC~ ~~~:~:c

0 RJR. T=lOOSPS

~ 1.8
~1.6

~1.4

ri 1.21.0
0.8
0.6~------------------~

0.0

0.2

0.4
0.6
KT (GeVlc)

0.8

1.0

Fig. 2. Rout! Rsid e for kaons at RHIC (full symbols) andat SPS (open symbols), as a function of K T for critical temperatures Tc ~ 160 MeV and Tc ~ 200 MeV,
respectively. The lines are to guide the eye.

around the mean. Therefore, the model calculations
suggest a rapid increase of Rout / Rside as a function of
KT if a thermalized QGP were formed.
Extending our analysis from pions to kaons 6 ) we findthat the kaon radii as well depend only weakly on
the thermalization time Ti, the critical temperature T c(and thus the latent heat), and the specific entropy of
the QGP. However, kaons are less distorted by decaysof (long-living) resonances. The predicted increase in
the R out / R s ide ratio with KT is rather moderate compared to pions.
At high transverse momenta KT rv 1 GeV /c, however, direct emission from the phase boundary becomes
important (approx. 30% of the kaons are then emitted
directly from the phase-boundary). The emission duration signal, i. e., the Rout! Rside ratio, and its sensitivity to T c (and thus to the latent heat of the phasetransition) are enlarged (see Fig. 2). Moreover, theQGP + hadronic rescattering transport model calculations do not yield unusual large radii (3 ::; Ri ::; 9 fm).
Finite momentum resolution effects have a strong impact on the extracted HBT parameters (Ri and A) as
well as on the ratio Rout! Rside .

-I

rl 1 .6......

References

JI.4
t.2

1.0

•

0

0.'
0.1i
OJ!

T("'200M.V,.t~
T c.2OG M.V. wbII hadronlc ....,.,ttn..
" ..... Tc=l60M.V••t~aunduy0
Tc.. UOM.V,wl&hhadtonlc_netina
•

0.1

0.2

0.3

0.4

0.5

KT(GeV)

Fig. 1. Rout! R side for pions at RHIC initial conditions,as a function of KT at freeze-out (symbols) and at
hadronization (lines).
*1

*2

204

Lawrence Berkeley National Laboratory, USA
Brookhaven ational Laboratory, USA

1) G. Goldhaber, S. Goldhaber , W. Lee, and A. Pais:
Phys. Rev. 120, 300 (1960).
2) E. Shuryak: Phys. Lett. B 44, 387 (1973).
3) S. Pratt: Phys. Rev. D 33, 1314 (1986).
4) S. Soff, S. A. Bass, and A. Dumitru: Phys. Rev. Lett.
86, 3981 (2001).
5) S. A. Bass and A. Dumitru: Phys. Rev. C 61, 064909(2000).
6) S. Soff, S. A. Bass, D. H. Hardtke, and S. Y. Panitkin:e-Print archive, nucl-th/0109055.

RIKEN Accel. Prog. Rep. 35 (2002)

Hadron spectrum for quenched domain-wall fermions
with an improved gauge action t
Y. AokiNumerical simulation with use of lattice gauge theory is a powerful tool to analyze QCD nonperturbatively. It provides method to calculate quantities fromthe first principle. However, in the restricted amountof computational resources there are always systematic
uncertainties to be carefully considered.
To define the lattice field theory, one needs as muchsymmetries as the continuum theory has. While it isexpected that the all symmetries are recovered in thecontinuum limit, breaking the symmetries in the finite
lattice generally could give rise the scaling violation
which becomes the major source of the systemati~
error.
Domain-wall fermion (DWF) action provides thegood control of the chiral symmetry and has exact flavor symmetry, which conventional fermion actions do
not have. It is useful for the calculation where thechiral symmetry is important. Moreover the scaling
properties appear to be excellent, which could be understood by the good symmetries it has. Contrary tothese good properties, there is a problem of increasing amount of computation from the existence of theextra-dimensional degree of freedom.
Studies 2 ,3) for quenched DWF have shown that if
the lattice spacing is small a < 0.1 fm the breakingof chiral symmetry is small m res ~ mu d with modest
size of fifth dimension Ls with wilsod gauge action.
And if one employs a renormalization-group improved
gauge action of Iwasaki,4) m res gets 1/10 times smaller
than that for Wilson. However, these studies also haveshown that for a > 0.1 GeV, in order to get the smallm r es. as for a ~ 0.1 GeV one needs extremely large L s,
whIch makes people avoid using it for application.
Motivated by the success of the improved gauge
action, we have investigated further improvement ofgauge action. We found that the DBW2 action 5)
which is a non-perturbative version of Iwasaki acti~nprovides a better chiral symmetry for the DWF. 6),
The measure of goodness of chiral symmetry is residual quark mass m res which is the additive renormalization to the quark mass , defined through the chiral Ward-Takahashi identity. The residual quark mass
vanishes in the limit of L s - t 00, realizing exact chiralsymmetry. We obtain for L s = 16m r es ~ 0.7MeV;a ~ 0.15fm,
m res ~ 0.03MeV 6 ); a ~ 0.1 fm.

(1)
(2)

m res for the DBW2 action at a ~ 0.1 fm is about 1/10
This work has been done in the RBC Collaboration. See
Ref. 1 for the more detailed article

experiment
1.'

I1

~.u

lee

(a)

I

i

K'

0

I

.....

"

I

, NlWilson
eK'IOBW2

o'(aIr/OO

~ 130

-"
_ NlDBW2

I
0,1

0.12

0 .1£

if

I

l.,l.

I

,

>140

N

(b)

K

e..tDBW2-KIOBW2

1I/W'iI!!onKlWil90nexperment

1100

Oa2"004-'-O:~};;;'

0,1

0 .12

0 .1.

Fig. 1. Nucleon and K*-to-rho mass ratios (a) and decay
constants (b) as functions of lattice spacing squared.

of that for the Iwasaki action at the same lattice spacing. We note that m res for the DBW2 action even ata ~ 0.15 fm is smaller than that for Wilson gauge action at a ~ 0.1 fm. This is a great advantage of using
the DBW2 action, as one can do the precise calculation
at a ~ 0.15 fm , where the simulation is much cheaper
than the finer lattice and the other action do not givesuch a small m res .
The next step is to test DBW2 gauge action whether
the basic physical spectrum is obtained without any
peculiarity. The main interest is how good the scaling property is for the spectrum. Figure 1 (a) shows
the nucleon-to-rho mass ratio and the K * -to-rho mass
ratio as functions of lattice spacing a normalized byconventional scale parameter ro calculated from theheavy quark potential.
Both nucleon and K* masses show good scaling andnucleon mass for DBW2 is fairly consistent with thatfor DWF /Wilson gauge data. 3 ) Figure 1 (b) shows thescaling of pseudoscalar decay constant. Both f1r andfK show the good scaling. f7T is consistent with theexperimental value but fK is not, which is expectedfrom the quenched chiral perturbation theory. 7)
In summary, the combination of quenched DWF and
DBW2 gauge action make chiral symmetry breaking
sufficiently small even for a coarse lattice a ~ 0.15 fm.
The hadron masses and decay constants show goodscaling. These indicate that one can use results obtained at a ~ 0.15 fm for the reliable continuum extrapolation.
References
1) Y. Aoki, RBC-Collaboration: hep-lat/Ol10143.
2) CP-PACS Collaboration, A. Ali Khan et al.: Phys. Rev.
D 63 , 114504 (2001).
3) T. Blum et al.: hep-lat/ 0007038.
4) Y. Iwasaki: UTHEP-1l8 (1983).
5) T. Takaishi: Phys. Rev. D 54, 1050 (1996).
6) K. Orginos: RIKEN Accel. Prog. Rep. 35, 212 (2002);
hep-lat/Ol10074.
7) C. Bernard and M. Golterman: Phys. Rev. D 46, 853(1992).

205

RIKEN Accel. Prog. Rep. 35 (2002)

Calculation of K----+ 7r7r decay in quenched domain-wall QCD
J. Noaki

One of the long-standing issue in lattice QCD isquantitative understanding of the K ~ 7r7r decay including the /:)..1 = 1/2 rule and the value of t:' /t:. This
article is a summary of our calculation of these decay amplitudes. I) We used the relations between theK ~ 7r7r and K ~ 7r matrix elements derived in chiralperturbation theory at the lowest order. 2 ) This method
avoids the serious problem in the direct calculation ofK ~ 7r7r, but requires the chiral symmetry on the lattice.
Our numerical simulations were carried out inquenched QCD with the domain-wall fermion action
and the renormalization group improved gluon action.
This choice is known to have advantage in the pointof chiral properties,3) compared to the other conventional actions. In this calculation, the gauge couplingcorresponds to the scale 1/ a = 1.94 Ge V. We usedthe domain wall height M = 1.8 and the fifth dimensional size Ns = 16. Gauge configurations are generated independently for each value of the degenerate
u-d and s quark mass , m j. Our statistics are summarized in Table 1 for the two lattice volumes andm j used in the calculation. The numerical task is tocalculate the K ~ 7r and K ~ 0 matrix elements of
the local 4-quark operators that appear in the effective
weak Hamiltonian. Each operator is divided into thecontributions to /:)..1 = 1/2 and 3/2 channels. Afterchecking the required chiral properties of the K ~ 7r
matrix elements, we estimated physical quantities in
the following way:
(1) We construct the K ~ 7r7r decay amplitudes fromthe K ~ 7r and K ~ 0 matrix elements.
(2) Renormalization of these matrix elements is madeperturbatively at one-loop level 4 ) at the scale 1/ a.
(3) The renormalization group running to me (=1.3 GeV) is carried out for the N j = 3. 5 )(4) Combining these results with the Wilson coefficients, we obtain the decay amplitudes AI, where1 = 0,2 is the isospin of final state.
In Fig. 1, we present the ratio w- I = Re Ao/Re A2
as a function of squared pion mass on the lattice,
We observe that the data from the volumes 163 (opensymbols) and 24 3 (filled symbols) are consistent . Lines
drawn are the fit curves with the quadratic function(solid) in m'iI or a form including chiral logarithm

m'iI.

~

20

experiment15

3o 16 x32
3.24 x32- - - - - chirallog.
quadratic

10

0.1

0.2

0.3

2

0.4

0.5

0.6

0.7

0.8

m", [GeV]

Fig. 1. The ratio w- 1 = Re Ao/Re A2 as a function of[Gey2]. See the text for the explanation.

mL

25
20
15

I

e'/e [10j

KTeV

I

NA48

10

*

-5

-10 '---'"--'---'-~....I...-'--'~--'-.~-'-~-'--'----'
o
0.1
0.2
0.3 2 0.4 2 0.5
0.6
0.7
0.8

mM [GeV]Fig. 2. E'IE, with symbols meaning same as in Fig. 1.

(dashed). The /:)..1 = 1/2 rule, i. e., w- I ~ 22, is reproduced only by about 50% in the chirallimit. Thissituation comes from the fact that whereas the 1 = 2
amplitude is reasonably consistent with experiment,
the 1 = 0 amplitude is sizably smaller.
Using our results for only 1m Ao,2' we obtain thevalues of t:' /t: seen in Fig. 2. In contrast to the experiments, our results are negative because the contributions from 1 = are smaller than those from 1 = 2.
These insufficient results come from the poor enhancement of /:)..1 = 1/2 channel that are regarded asa pathology of this method.

°

References
Table 1. Numbers of configurations generated in our calculation for each combination of m f and volume.
mf

16 3 x 32
24 3 x 32

206

0.02
407
432

0.03
406
200

0.04
406
200

0.05
432
200

0.06
435
200

1) CP-PACS Collaboration, J. Noaki et al.: hep-Iatl
0108013.
2) C. Bernard et al.: Phys. Rev. D 32, 2343 (1985).
3) CP-PACS Collaboration, A. Ali Kahn et al.: Phys. Rev.
D 63 , 114504 (2001).
4) S. Aoki et al.: Phys. Rev. D 60 , 114504 (1999).
5) A. J. Buras et al.: Rev. Mod. Phys. 68 , 1125 (1996).

RIKEN Accel. Prog. Rep . 35 (2002)

CP violation in K decay from lattice QCDt
T. Blum
Last year we reported on progress towards the determination of matrix elements of the effective weak
Hamiltonian describing strangeness changing nonleptonic weak decays of kaons from first principles using lattice QCD.I) This year we summarize the complete results of that calculation. 2) Such matrix elements are necessary to determine the ratio of C P violation parameters E' / E in the Standard Model (seeFig. 1) which have been measured in experiments at
Fermilab and CERN. We have also computed the realparts of these K --+ 7r7r decay amplitudes which yieldthe /j.I = 1/2 rule for kaon decays. The enhancement
observed in the isospin zero decay channel has beena long standing t heoretical puzzle in particle physics.
Our results are summarized in Table 1.
Defining decay amplitudes asA(Ko --+ 7r7r(I)) = AI ei8 ! ,A(KO --+ 7r7r(I)) = -A; e i8 ! ,(1)

where I = 0, 2 is the isospin of the final state pions
and 61 the corresponding s-wave phase shift, it can beshown that~ = ie - i (8o - 82 ) ReA 2 (ImA2 _ ImA o )E
J2E ReA o ReA 2 ReAo'(2)

where we have neglected isospin breaking effects (theseare expected to decrease the value of E'). The factors
outside of the parentheses are well known experimen-

0 . . . . .......... . . . . . . . . . . . ---------------------.. ------.-.. . ----.. -------

~~
~

tl;<:
-20
p..
'-'

~ -40

1~-60

F ig. 1. The ratio of CP violation parameters E' /E . Totals
are shown for lowest order (upper) and one-loop (lower)chiral perturbation theory. The I = 0 and 2 contributions are shown for the one-loop case only.

Table 1. Summary of the calculation and comparison withexperiment. The amplitudes are in units of Ge V. The
experimental results for E'/E are from the NA48 (firstentry) and KTEV experiments.
Quantity
Re Ao
Re A2
w- 1

Re (E'/E)

Experiment3.33 X 10- 7
1.50 X 10- 8
22.2
15.3(26) x 10- 4
20.7(28) X 10- 4This calculation
2.96(17) X 10- 7
1.172(53) X 10- 8
25.3(18)- 4.0(23) x 10- 4

tally, so we quote values of E' / E using these known values. Thus , the calculation of E' I E boils down to determining the difference of ratios PI ::::: 1m AI IRe AI'
The /j.I = 1/2 rule is simply given by the ratio of
the real parts of the I = 0 and 2 amplitudes, w - 1 ==ReA o/ReA 2.
In Fig. 1 we show E' / E as a function of a fictitious
mass parameter ((m; , mk) --+ ~ x (m;, mk) in A O,2)
which allows us to study the chiral behavior of our result. At the physical point ~ = lour result is small andslightly negative in contrast to the experimental one.
This happened because of a nearly complete cancellation between the two channels which are dominated by
the QCD penguin operators Q6 and Q4 and the electroweak penguin Q8 , respectively. On the other-hand,
our result for the /j.I = 1/2 rule is consistent withexperiment. At the renormalization scales used in ourstudy, we find a large enhancement of the I = 0 matrix
element of the progenitor weak operator Q2 over theI = 2 one which along with the perturbative enhancement of roughly a factor of two is enough to explain
most of the /j.I = 1/2 rule. The contributions fromthe QeD penguin operators are small.
Our calculation which represents a significant milestone in the calculation of non-Ieptonic kaon decays has
significant approximations including quenching, useof perturbation theory below mcharm , and incomplete
next-to-Ieading order calculations in chiral perturbation theory which will be addressed in future calculations. The road ahead will be interesting, especially if
we must turn away from the Standard Model.
References
1) T. Blum: RIKEN Accel. Prog. Rep. 34, 277 (2001) .
2) T. Blum, et al.: (RBC), hep-Iat/Ol10075; J-1. Noaki,
et al.: (CP-PACS), hep-Iat/0l08013.

This work was done in collaboration with N. C hrist , C.
Cristian, C. Dawson , G. Fleming, X. Liao, G. Liu, S. Ohta,
A . Soni , P. Vranas, R. Mawhinney, M. Wingate, L. Wu, andY. Zhestkov. We t hank RIKEN, Brookhaven National Laboratory and the U. S. Department of Energy for providing
the facilities essential for this work .

207

RIKEN Accel. Prog. Rep . 35 (2002)

Chirality and localisation of domain wall fermion eigenvectors t
C. Dawson, for the RBC Collaboration
The spectrum of a Euclidean-space, anti-hermitian,chirally symmetric Dirac operator, D, may be split up
into either zero-modes with eigenvector chirality ±1 or
paired modes, 'l/J±i>.., with imaginary eigenvalues ±iA,
"Y5'l/Ji>.. = 'l/J-i>.. and zero chirality. Lattice QCD provides
a technique to study both the eigenvalue spectrum andthe structure of the corresponding eigenvectors.
In particular while the global chirality of the paired
modes must be zero the mechanism behind this is ofinterest. One possibility is that locally the eigenvectors have a definite ±1 chirality (cf. Instanton Liquid
Model) which adds to zero over all space-time, or the
local chirality could be random, averaging to zero overa much smaller volume. Since being introduced in thecontext of Wilson fermions in Ref. 1 which favoured
the latter picture this question has been addressed bymany groups .2- 5) Here we will summarise the resultsof our study6) using domain wall fermions (DWF). 7)
This fermion action has , at the expense of introducing a fifth dimension, chiral properties at finite latticespacing that are greatly improved over standard actions and so is well suited to this problem.
To study this question we solved for the low-lying
eigenvectors of the hermitian DWF Dirac operator"Y5 RD DWF
where DDWF is the DWF Dirac operator using the conventions given in Ref. 8 and R is reflection about the
middle of the fifth dimension. From these we construct
4d vectors , W4d, by summing the left-hand half of the
5th dimension to form the left-hand part of the 4deigenvector and similarly with the right-hand piece. As
we are only looking at the low-lying modes, which arevery well localised to the domain wall,6,8) this should
be a good representation of eigenvectors of a hermitian
4d Dirac operator "Y5( D + m), with a finite mass arising from both the bare input mass and residual chiralsymmetry breaking effects from DWF. For our study
the mass will be very small, and for simplicity it will be
neglected in the following. See Ref. 6 for a treatmentof these corrections.
We studied a quenched gauge field ensemble of 55
configurations generated using the Iwasaki gauge action with a 16 4 lattice volume and an inverse latticespacing of approximately 2 Ge V. For each configura-This work was done in collaboration wit h T . Blum, N .
Christ, C. Cristian, G. Liu, R. Mawhinney, L. Wu, and Y.
Zhestkov. We thank RIKEN, Brookhaven National Laboratory and the U. S. Department of Energy for providing thefaci lities essential for this work.

208

Fig. 1. L (x) for the Iwasaki ensemble.

tion we solved for the lowest 18 eigenvalues and thecorresponding eigenvectors using a fifth dimension ofsize 16 and a bare quark masses of 5 x 10- 4 .
To study the localisation of chirality we fist separate t he eigenvectors into paired and non-paired bymaking a cut on the absolute value of the global chirality with anything above 0.8 being considered a zeromode. We then construct the local norm of each vector nH(x) = Wld(x)w4d( x) and t he local chirality
XH( x) = wld(x)"Y5 W4d( x) . We pick out the points
in the lattice that contribute most by making cuts
nH > nmin and for the admitted points we histogram
the local chirality,

If the eigenvectors are locally chiral this will clusteraround ±1, whereas a fiat distribution would be expected if the chirality were random. Figure 1 shows
this histogram for nmin > 3 . 105 and nmin > 8 . 10 5This corresponds to admission of 6% and 29% of t hetotal norm respectively. As can be seen it is clear t hat
using DWF the paired modes of the low-lying eigenvectors are locally chiral.

References
1) 1. Horvath et al.: hep- latj0102003.
2) 1. Hip et al.: hep-lat j 0105001.
3) C. Gattringer et al.: hep-latj0107016.
4) R. G . Edwards and U . ~ . Heller: hep-latj0105004 .
5) T . DeGrand and A . Hasenfratz: hep-latj0103002.
6) T. Blum et al.: hep-latj0105006.
7) Y . Shamir: Nucl. Phys . B 406 , 90 (1993).
8) T . Blum et al.: hep-latj0007038.

RIKEN Accel. Prog. Rep. 35 (2002)

QCDOC project t
P. A. Boyle,*1,*2 D. Chen,*3 N. H. Christ,*2 c. Cristian,*2 Z. Dong,*2 A. Gara,*3 B. JOO,*1,*2 C . Kim,*2
L. Levkova,*2 X. Liao,*2 R. D. Mawhinney,*2 S. Ohta,*4 T. Wettig,*5 and A. Yamaguchi*2
The QCDOC (QCD On a Chip) project started in
1999 as a joint effort of RIKEN, Columbia University and IBM Research to design a massively parallel computer optimized for lattice quantum chromodynamics (QCD). The architecture combines stateof-the-art system-on-a-chip technology with customdesigned 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) The British UKQCD collaboration and the US lattice gauge theory community
later endorsed the project.
For physically relevant lattice QCD numerical calculations to be completed within a reasonable amountof time, it is essential to distribute the total volume
onto as many nodes as possible. This implies small local lattice volumes, as small as 24, and hence requires
communications between neighboring nodes with extremely low latencies that cannot be achieved using
off-the-shelf networking components used in PC clusters such as Myrinet. Massively parallel machineswith custom-designed communications hardware (withlatencies 10- 100 times smaller than in the case of
Myrinet) appear to be the only viable alternative.
The QCDOC architecture is capable of delivering computing power in the tens of TFlops range
at a price/performance ratio of 1 US$ per sustained MFlops. QCDOC is a multiple-instruction,
multiple-data (MIMD) machine with distributed memory. Nowadays it is possible to integrate the components that make up a single processing node on a single
chip, creating an application-specific integrated circuit(ASIC). The QCDOC chip is such an ASIC, consistingof (a) a 500 MHz , 32-bit PowerPC 440 processor core,(b) a 64-bit , 1 GFlops floating-point unit, (c) 4 MBytes
embedded-DRAM memory, (d) controllers for embedded and external memory, (e) nearest-neighbor serial
communications unit (SCU) with latencies of 120 ns(300 ns) for send (receive) , overlapped between the 12
independent directions and an aggregate bandwidth of
12 Gbit/s, and (f) other components such as Ethernet
controller, etc. The power consumption of the chip
will be in the range of 1- 2 Vi. Two such ASICs will
be mounted on a daughterboard, together with two

*1

*2

*3

*4
*5

industry-standard double data rate (DDR) SDRAM
modules (one per ASIC). 32 daughterboards will bemounted on a motherboard, and 8 motherboards in a
crate with a single backplane. The final machine consists of a certain number of such crates.
There are two separate networks: the physics network and an Ethernet-based auxiliary network. The
physics network consists of high-speed serial links between nearest neighbors with a bandwidth of 2 x
500 Mbits/s per link. The nodes are arranged in a
6-dimensional torus which allows for an 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 over Ethernet, with
an Ethernet controller integrated on the ASIC. Hubsor switches on the motherboard will provide a bandwidth of 1.6 Gbit/s off a motherboard to commercial
switches and the host workstation.
The ASIC functional design is nearly finished.
Single-node physics code is running on the VHDL simulator , and from these simulations we obtained the performance figures of about 50% efficiency maintained
for lattice QCD calculations. In another test environment two nodes have successfully communicated in the
VHDL simulator over their Ethernet interfaces and/or
the HSSLs. The operating system is being developedon a system with seven PowerPC boards, five EthernetJTAG boards, and a RISCWatch probe. The current
design has been successfully synthesized, and an analysis net list has been provided to IBM for floorplanningpurposes. Anticipating a few iterations to satisfy timing constraints the complete design should be transferred to IBM by the end of 2001. Production of thechi p can start after that .
References
1) D. Chen et al.: Lattice 2000, Bangalore, India, 2000-8;
hep-lat / 00l1004, Nucl. Phys. B (Proc. Suppl.) 94, 825(2001); P. A. Boyle et al.: Lattice 2001, Berlin, Germany, 2001-8 ; hep-Iat/0110124, Nucl. Phys. B (Proc.
Suppl.) 106, 177 (2002).

We thank RIKEN and the US Department of Energy
University of Edinburgh, UK
Columbia University, USA
IBM Research, USA
Institute for Particle and Nuclear Studies, High-Energy Accelerator Research Organization (KEK)
Yale University, USA

209

RIKEN Accel. Prog. Rep. 35 (2002)

QeD phase structure with many flavors
S. Kim*l and S. Ohta*2
In the perturbative expansion of Callan-Symanzik
iJ-function of quantum chromo dynamics (QCD),ogiJ(g) = f.L Of.L = bOg3 + b1 g5 + O(g7),the first two coefficients, bo and b1 , are dependent on
the number of light flavors, Nj. Since they changesigns at different Nj, a non-trivial zero may develop
in iJ(g). It was argued that such a zero may change
the long or short distance behavior of QCD.!) Within
this perturbation analysis this can only happen for
N j > 8, and the zero resides in a region in the coupling where the perturbation cannot be valid. Hence
this interesting problem is left to be investigated nonperturbatively. Indeed there have been several lattice studies with multi-flavored QCD 2- 4 ) which suggest
such rich phase structures.
For eight light staggered quark flavors, there is astrong first order phase transition which separates thestrong coupling region from the weak coupling region.
For a given lattice spatial volume, this transition appears to be Nt-independent bulk transition where Nt is
the number of sites along the time direction. The weakcoupling phase is divided into two region: in one regionof weak coupling space chiral condensates shows linear
behavior in quark mass, and in the other region theyshow non-linearity.3) It has been speculated that there
may be a normal finite temperature phase transition
between these two different weak coupling phases. On
the other hand, using simulation results with Wilson
quark formulation in the strong coupling limit, the authors of Ref. 4 argue that lattice QCD for Nj 2:: 7 has
an interesting limit without quark confinement. Even
if the color confinement and the spontaneous chiralsymmetry breaking is rigorously proven in the infinite
coupling limit (in quenched approximation to QCD), it
is claimed that copious addition of light quark flavors
modifies the string-like vacuum structure of a theory
with gluon only.
Although the existence of a strong first order bulk
phase transition which separates the strong couplingregion and the weak coupling one is well established,

*1

*2

210

Sejong University, Korea
Institute for Particle and Nuclear Studies, High-Energy Accelerator Research Organization (KEK)the continuum limit of lattice theories for multi-flavor
QCD is much less clear. For staggered quark simulations, investigation of the weak coupling phase by useof hadron spectroscopy calculation was hampered bysmall spatial lattice volumes. 3) Simulation result with
Wilson dynamical quark in the strong coupling limit isdifficult to make a contact with the continuum limit.
Further study in the weak coupling phases of multiflavor QCD using light dynamical quarks is needed.
Here, we would like to endeavor toward this direction.
Our efforts will be concentrated on various susceptibilities such as chiral susceptibility and finite size scalingof them. 5 )We use the R-algorithm 6) to simulate QCD with arbitrary number of quark flavors and employ staggered
fermion method for the dynamical quarks. Target platform for our project is the 128-node Fujitsu VPP-700
at RIKEN. As a first step, the weak coupling phaseswith Nj = 6 and 8 are investigated. There exist a linear relation between the chiral condensate and the light
dynamical quark mass, which is in agreement with theearlier results. For the planned more detailed investigation of the weak coupling phase, several aspectsof the current lattice calculation need to be refined:
First, we need to test whether the systematic error
arising from finite step size of the current algorithm
is small enough. Second, we need to add more observables: various susceptibilities such as chiral susceptibility calculation and specific heat calculation are
currently being implemented.
References
1) T. Banks and A. Zaks: Nuel. Phys. B 196, 173 (1982).
2) J. B. Kogut et al. : Phys. Rev. Lett. 54, 1475 (1985);
M. Fukugita, et al.: Phys. Rev. Lett. 60, 178 (1988).
3) F. R. Brown et al.: Phys. Rev. D 46, 5655 (1992).
4) Y . Iwasaki et al.: Prog. Theor. Phys. Suppl. 131, 415(1998); Nuel. Phys. B (Proe. Suppl.) 42, 502 (1995);
Nucl. Phys. B (Proe. Suppl.) 53,449 (1997); Phys. Rev.
Lett. 69 , 21 (1992).
5) S. Kim and S. Ohta: Lattice 2001, hep-Iat/Oll1040,
Nuel. Phys. B (Proe. Suppl.) 106, 873 (2002).
6) S. Gottlieb et al.: Phys. Rev. D 35, 2531 (1987).

RIKEN Accel. Prog. Rep. 35 (2002)

Nucleon axial charge on the latticeT. Blum, S. Ohta,*l K. Orginos, and S. Sasaki*2
The domain-wall fermion (DWF) method in lattice quantum chromo dynamics (QCD), practical useof which has been pioneered by the RIKEN-BNLColumbia-KEK QCD collaboration, preserves the important chiral symmetry almost exactly1) the violation
is exponentially suppressed by adjusting parameters
associated with the extra fifth lattice dimension. The
nucleon (iso-vector) axial charge g A poses an interesting challenge for this method. From neutron j3 decay
we know its experimental value gA = 1.2670(35) inunits of the conserved vector charge, gv = cos BCabibbo.
Deviation of the ratio g A/ gv from unity, in contrast to
the conservation of the vector charge, gv itself, reflects
the fact that the axial current is only partially conserved in the strong interaction because of the spontaneous breakdown of the chiral symmetry. Thus, thecalculation of g A is an especially relevant test of thechiral properties of the DWF method in the baryon
sector. It is also an important first step in studying polarized nucleon structure functions. An important advantage of the DWF method, in contrast to
the conventional met hods , is that we can maintaina relation Z A = Z v between the lattice renormalizations of the axial and vector currents so that thelattice value (g A/ gv ) lattice directly yields the continuum value (gA / gv )con. Our first DWF calculation with
Wilson's single-plaquette gauge action found the ratio
gA/gv with a strong quark-mass dependence , and asimple linear extrapolation to the chiral limit yieldeda value about a factor of two smaller than the experiment. This deviation might be caused by such systematic effects as finite lattice volume and quenching(for example quenched chiral logarithms , zero modes ,and the absence of the full pion cloud). In the present
work we focus on the former: while the first calculation employed a rather small physical volume of about(1.6 fm)3 , the present work employs about (2.4 fm)3.
Given the current capabilities of the QCDSP supercomputer, this large volume would result in an unacceptably large chiral symmetry breaking if we kept
using the Wilson's gauge action because one would beforced to use coarser lattices. Fortunately, however,recent studies from the RBCK collaboration 2) haveshown that renormalization-group inspired improved
gauge actions, such as the DBW2 action,3) suppresses*1*2

2.0r----~----------,

1.5 -

~

1.0~

0.5 -

•

DBW2 (1SSx 32 lattice)o DBW2 (S3X 24 lattice))( Wilson
O.O~~I_~~
1_~I~_..a...._......&.'_ _..I-I

0.0

0.2

0.4

0.6

0.8

1.0

Fig. 1. 9 A j 9v plotted against pion mass squared, scaledwith p-meson mass squared. DBW2 (filled and open
circles) and Wilson (cross) actions.

the symmetry breaking by two orders of magnitude,
enabling the current study. As shown in Fig. 1, ourpreliminary results using DBW2 gauge action represented by filled (larger volume of '" (2.4 fm)3) and open
(smaller volume of '" (1.2 fm)3) circles, prove a clear
finite volume effect, which seems to become large inthe lighter quark mass region. In addition, the larger
volume results have a milder quark mass dependence
except for the two lightest points, which still have large
statistical errors. On the other hand, the smaller volume results seem to be in rough agreement with ourprevious results using the Wilson gauge action (x)with the strong mass dependence.
References
1) RBCK Collaboration, T. Blum et al.: hep-latj0007038,
to appear in Phys. Rev. D; hep-latj0102005, submitted for publication in Phys. Rev. D; hep-latjOl10075,
submitted for publication in Phys. Rev. D; T. Blum,
S. Ohta, and S. Sasaki: Lattice 2000, Nucl. Phys. B(Proc. Suppl.) 94, 295 (2001); and references cited inthese works.
2) RBCK Collaboration, K. Orginos et al., in preparation;
RBCK Collaboration, Y . Aoki et al., in preparation.
3) QCD-TARO Collaboration: Nucl. Phys. B 577, 263(2000).

Institute for Particle and Nuclear Studies, The High-Energy
Accelerator Research Organization (KEK)
D epartment of Physics , University of Tokyo

211

RIKEN Accel. Prog. Rep. 35 (2002)

Gauge actions and chiral symmetry of domain wall fermions
K. Orginos, and RBC Collaboration
We report here our results from our studies of
the residual chiral symmetry breaking of domain wall
fermions for the I-loop Symanzik, Iwasaki,1) and
DBW2 actions. The DBW2 action was introduced inRef. 2 and it was shown by QCD-TARO in Ref. 3 that
it is a good approximation of the RG flow on the twodimensional plane of the plaquette and rectangle couplings.
All the above gauge actions can be written as

Be =

~

(co

L

PJ-LV

+ CI L

X;J-L<V+C2

L

Table 1. The simulation parameters for all the actions.
ActionWilson 5)
Symanzik
Iwasaki
DBW2

f3

Mp

6.00
8.40
2.60
1.04

0.404(8)0.411(14)0.415(13)0.399(11)

M5
1.8
1.8
1.8
1.7

Ls
12- 24
16
16
8- 16

RJ-Lv

x;w:PVCJ-Lva) ,X;J-L<v<awhere PJ-LV is the standard plaquette in the /-l, v plane,
and RJ-Lv and C J-Lva denote the real part of the traceof the ordered product of SU(3) link matrices along
1 x 2 rectangles and 1 x 1 x 1 paths, respectively. For
the I-loop Symanzik action the coefficients Co, CI, andC2 are computed in tadpole improved one loop perturbation theory.4) While C2 = 0 and Co = 1 - 8CI for
both Iwasaki and DBW2, CI = -0.331 and -1.4069
respecti vely.
As a measure of the chiral symmetry breaking we
use the so called residual mass ,

m

res

=

5
(Jg(0)J (t)) I(J5(0)J5(t)) t~tmin 'where Jg is the mid-point chiral symmetry breaking
term which appears in the axial Ward identity of domain wall fermions , and trnin is sufficiently large to
avoid short-distance lattice art ifacts.
We present the simulation parameters we used inTable 1. In Fig. 1 we show the Ls dependence of theresidual mass. All data are for a-I = 2 GeV and barequark mass mq = 0.02. The value of ~p is within 10%of .55. Since we are interested in differences by factors of ten, and since we know that the m res depends
mildly on the quark mass,5 ,6) the data can be directlycompared as is. For completeness we also present the
CP-PACS residual mass results. 6) We have confirmed
their results for Ls = 16 (diamond in Fig. 1). For the
Symanzik action we ran at Ls = 16 only; the residual mass turns out to be smaller by a factor of three
than the Wilson residual mass at the same L s , and it
is larger by a factor of two than that of the Iwasaki
action. The DBW2 action not only gives the smallest residual mass, but also has the steepest decrease
as a function of Ls. Since we have only three points,
we cannot claim that we know the asymptotic behav-

212

10

20

Fig. 1. L s dependence of m r es at a-I rv 2 GeV. The octagons correspond to the DBW2 action, the squares(CP-PACS 6 )) and diamond (RBC) to Iwasaki, the burst
to Symanzik, and the fancy squares to Wilson.

ior; it is interesting to note however, that a simple fit
gives us mres(s) rv qS with q rv 0.6. Shamir's one loop
perturbative result 7) is q = 0.5.
Using the DBW2 action, we have essentially eliminated the problem of residual chiral symmetry breaking for domain wall fermions at 2 GeV with Ls = 16.
Assuming a 440 MeV string tension, the bare DBW2
residual mass is about 30 KeV. Our results also suggest that the DBW2 action should also be useful foroverlap fermions , since it probably makes the approximation to the sign function converge faster by eliminating the small eigenvalues of the Hermitian Wilson
Dirac operator.
References
1) Y. Iwasaki: unpublished UTHEP- 118 (1983).
2) T. Takaishi: Phys. Rev. D 54, 1050 (1996).
3) P. de Forcrand et al.: ucl. Phys. B 577, 263 (2000).
4) M. G. Alford et al.: Phys. Lett. B 361 , 87 (1995).
5) T. Blum et al.: hep-lat j 0007038 (2000).
6) A. Ali Khan et al.: Phys. Rev. D 63, 114504 (2001)
7) Y. Shamir: Phys. Rev. D 62 , 054513 (2000).

RIKEN Accel. Prog. Rep . 35 (2002)

Scalar glueball mass reduction at finite temperature
in SU(3) anisotropic lattice QeD
N. Ishii, H. Suganuma,*1 and H. Matsufuru*2
Finite temperature QCD is one of the most interesting subjects in the quark hadron physics. At high temperature, QCD undergoes the deconfinement and/or
chiral phase transition at the critical t emperature T eto the quark gluon plasma (QGP) phase, and significant changes are expected such as the existence of isolated quarks and gluons. However , even below T e , a lotof phenomenological effective models predict changes
in the hadronic properties. Although the lattice QCD
Monte Carlo simulation provides a model independent
method to study the nonperturbative natures of QCD,
the lattice QCD studies of the thermal hadron properties had been inadequate until quite recent. This is dueto the difficulty in measuring hadronic two-point correlators on the lattice at finite t emperature. At finite
temperature, owing to the shrink of the physical temporal size of the lattice and the consequent reduction of
the number of lattice points in the temporal direction,
the accurate mass measurement from the temporal correlations is quite difficult. Hence, the finite temperaure mass shift had been studied through the spatial
correlations, i.e., the screening mass , which, however ,is afflicted with the mixture of the large Matsubara
frequencies. I ) Recently, the use of the anisotropic lattice has been established,2) which makes it possible tostudy the mass shift directly from the temporal correlations. Here, we report the thermal glueball properties
below Te using quenched SU(3) lattice QCD. 3- 5 )To study the thermal glueball properties, at finite
temperatute, we need the smearing method 6 ) in addition to the anisotropic lattice. The smearing method
is a method to enhance the ground state contribution in the two-point correlator. The simplest interpolating field for the glueball is the plaquette operator¢, which, however, has only a weak overlap with theground state glueball, i. e., I(GI¢IO) 12 is rather small.
Instead , the correlator receives sizable contributions
from excited states, which makes the accurate massmeasurement difficult , especially at high temperature
where the physical temporal size of the lattice is limited. It is known that this is due to the fact thatthe "size" of the plaquette operator is O(a), which
is much smaller than the physical size of the glueball. 6) The smearing method is used to generate thespatially extended operator with a definite "size" very
systematically. By choosing the smearing parameters
so that the extended operator has the same "size" asthe physical size of the glueball, we can maximize theground state overlap, which is the original usage of*1*2

Faculty of Science, Tokyo Institute of Technology
Yukawa Institute of Theoretical Physics, Kyoto University

the smearing method. 6 ) However , it can be also used
to give a rough estimate of the glueball size by numerically seeking for the best smearing parameters
to achieve the maximum ground state overlap. The
physical size of the glueball is then estimated by the"size" of the corresponding extended glueball operator. 3 ,4) In this way, we can simultaneously study boththe mass and the size of the glueball at finite temperature based on the two-point correlators in quenchedSU(3) lattice QCD. In Fig. 1, thus obtained thermal
glueball masses are plotted against the temperature. 4 )The solid circle denotes the 0++ glueball mass, and theopen circle the 2++ glueball mass for reference. We
see that, at low temperature (T = 126 MeV), we haveme ~ 1.54 Ge V for the 0++ glue ball , which is consistent with me ~ 1.5 rv 1.7GeV. 7 ,8) In comparison tothis, we observe about 20% mass reduction of the 0++
glueball mass at higher temperature (0.8Te < T < Te)
as me(T) ~ 1.25 ± 0.1 GeV. As for the glueball size,
we find no significant change for the 0++ glueball, andthe estimated 0++ glueball size is R ~ 0.5 rv 0.6 fm
both at low and high temperature.
2.5
:0

>'o

2

Q
h

(:5
~

1.5

:e:

:.:

:.:

:.:

150

200

250

T [MeV]
Fig. 1. The thermal glueball masses plotted against temperature. The solid circle denotes the 0+ + glueballmass, and the open circle the 2+ + glueball mass. The
vertical dotted line indicates the critical temperature
T c ::= 260 Me V for the deconfinement transition.

References
1) C. DeTar and J. B. Kogut: Phys. Rev. Lett. 59 , 399(1987).
2) T. R. Klassen: Nucl. Phys. B 533, 557 (1988).
3) N. Ishii, H. Suganuma, and H. Matsufuru: hep-Iat/
0109011.
4) N. Ishii, H. Suganuma, and H. Matsufuru: Proc. Leptop Scattering, Hadrons and QCD, Adelaide, Australia,

213

2001-3 (World Scientific, 2001), p. 252.
5) N. Ishii , H. Suganuma, and H. Matsufuru: Proc. Lattice2001 , Berlin, Germany, 2001-8, Nucl. Phys. B (Proc.
Suppl.) , 106-101, 516 (2002).
6) APE Collaboration: Phys. Lett. B 192, 163 (1987).

2147) C . J. Morningstar and M. Peardon: Phys. Rev. D 60,
034509 (1999).
8) J. Sexton, A. Vaccarino, and D . Weingarten: Phys. Rev.
Lett. 15 , 4563 (1995).

RIKEN Accel. Prog. Rep. 35 (2002)

Calorons and localization of Dirac eigenvectors in lattice QCD
T. Wettig*
One of the many interesting features of QCD is thefinite-temperature chiral phase transition, (;j;'!jJ) -+ 0
as T -+ Te. It can be understood in terms of theei~envalue spectrum of the QCD Dirac operator, since('!jJ'!jJ) = -7rp(O)/V, where p('\) is the eigenvalue density. In the instanton liquid model, the nonvanishingvalue of p(O)/V originates from the quasi-zero modes
that result from the shift of the exact zero modes ofnoninteracting instantons to values of order O(l/V)
after interactions are turned on. As T -+ T e , instantons and anti-instantons combine to form molecules ,and the associated eigenvalues are no longer of orderl/V so that (;j;'!jJ) -+ O.
We are interested in relating this picture to the localization properties of the Dirac eigenfunctions. If chiralsymmetry is broken, they must be extended. (Proof bycontradiction: Because of the fermion determinant and
the Jacobian resulting from diagonalization , the eigenvalues are repelled from the origin. The mechanism
to compensate for this and to ensure that p(O) /V #- 0
is repulsion between the eigenvalues. However, if theeigenfunctions were localized, the eigenvalues would be
uncorrel~ted so that there is no eigenvalue repulsion,
hence ('!jJ'!jJ) = 0.) The question now is whether thechiral phase transition is reflected in a change of thelocalization properties of the Dirac eigenfunctions.
In the quenched case, attention must be paid tothe phase of the Polyakov loop which clusters around() p = 0, ±27r /3 because of a Z3 symmetry of the gauge
action. For T > 0, the classical solutions of the field
equations are called calorons, which are periodic instanton configurations that are localized in space but
not in time. We find that the corresponding zeromodes fall off like

1'!jJ12 rv e- 2(11"-If) p l) rT /r2

for large r,i. e. the localization length depends on the Z3 sector.
As a measure of localization, we define the gaugeinvariant probability density p)..(x) = L, :~ l 1'!jJ~(x)12and the ('5)-density \/5)(X) = L:~l '!jJ~(X)t'5'!jJ~(X).
These quantities were computed in lattice simulations
using staggered fermions and the Wilson l ) as well as
the Liischer-Weisz 2 ) gauge action. We expect, and indeed find in the lattice simulations, characteristic differences in the localization patterns between the Z3
sectors if (and only if) T > Te. Only the real sector(()p ~ 0) shows localization in space, which means thatthe eigenstates must be extended in time since a localized state would be unaffected by a Z3 transformation.
To see whether the difference in the localization
properties is due to the presence of calorons, we test

0.01

0.005

0.00150.001

0.0005oFig.!. A "caloron" state on a 12 3 x 6 lattice for (3 = 6.1
in the () p ~ 0 sector. The gauge-invariant density isplotted above, the expectation value of,5 below. Bothshow localization in space but not in time.

the localization pattern in 4-d on a 123 x 6 lattice bydefining
i = x + 12t
j = y + 12z

withx, y, z = 0, ... , 11

t = 0, . . . ,5.
The quantities p).. (x) and \/5)(X) are plotted in Fig. 1
for a mode corresponding to a very small eigenvalue.
This mode is also an approximate chiral eigenstate
within the limitations of staggered fermions.
The advantage of our method is that it allows us tocharacterize the semiclassical properties of the gauge
field without any cooling. For T > Tc we find isolatedmodes with definite handedness that are localized inspace but not in time and thus show essential properties of quark states associated with calorons.
I would like to thank M. Gockeler , P. E. L. Rakow,
A. Schafer, and W. Soldner for fruitful collaborations.
References
1) M. Gockeler et al.: Phys. Rev. Lett. 87, 042001 (2001).
2) M. Gockeler et al.: hep-Iat/ Ol10182.

Yale University, USA

215

RIKEN Accel. Prog. Rep. 35 (2002)

Overview of RIKEN jRBRC activities for RHIC spin physics 2001
H. En'yo and G. Bunce*
We succeeded in storing and accelerating polarized
proton beams for the first time at RHIC last year. 1)
We are going to start a physics run this year using
polarized proton-proton collisions at JS = 200 Ge V.
The goal of the machine commissioning is to provide beam polarization of 50% or more and luminosity of 5 x 1030 cm- 2 sec- 1 . If these goals are met, weshould be able to carry out significant measurementsof single transverse-spin asymmetries AN and double
longitudinal-spin asymmetries ALL for hadron and lepton production at the highest energy ever achieved.
The RHIC has achieved its designed values inenergy (= J S N N = 200 Ge V) and luminosity (=2 X 10 26 cm- 2 sec- 1 ) . The PHENIX experiment has
accumulated 42 p,b- 1 on tape, which is about 10 times
the integrated luminosity of last year. We have juststarted to inj ect polarized proton beams to RHIC
rings at the injection energy of 24.5 GeV Ie. Both
RHIC rings have a proton-carbon CNI polarimeter 2 )and complete sets of snake magnets thus we should be
able to accelerate polarized proton beams to 100 GeV,
where we observed zero polarization with single snake
operation 1 ) last year. The beam polarization will be
determined using the final results from AGS E-950. 3 )This year we are going to use a newly made waveform digitizer to manage the pile-up of events 2 ) due tothe anticipated high beam currents. The analysis code
has been developed based on the results from detailed
analysis of last year's data. 4 )For PHENIX, we have significantly extended the active volume this year with an additional read-out electronics for the electromagnetic calorimeter, and withcompletion of the South Muon Arm. 5 ,6) The Muon
Identifier has been operated successfully in the highestenergy gold-gold collisions 7) and its performance has
been greatly improved by shielding the area close to
the beam pipe with steel blocks. 8 ) For the polarized
pp run, which is to start soon, we have added a normalization trigger counter, trigger boards for EMCaland RICH and a TO counter for trigger-bias studies.
The expected reaction rate with this year's luminosity(£ = 5 x 10 30 cm- 2 sec- 1 ) is 250 kHz. Possible bottlenecks this year are event builder data processing (~1.2 kHz) and the total bandwidth (~30 Mbyteslsec ~700 Hz). Extensive studies on trigger performance are
ongoing and will be fully ready for the physics run.
For example, a sample of hadron with large transverse
momentum, which is sensitive to gluonic contributions
such as gluon polarization ~g( x), can be enhanced byboth level-1 and level-2 triggers. g )In calculating the asymmetries , which are actually
Brookhaven National Laboratory, USA216

asymmetries in reaction cross sections, stable luminosity and polarization monitoring are irreducible. Since
we are searching for asymmetries of the order of ~ 1%,
the luminosity monitoring must be precise and stable.
Towards this end, scaler boards for 120 bunches havebeen developed and commissioned in gold-gold collisions. This special monitoring program 10 ) has beendeveloped especially to show zero asymmetry measurements using gold beams.
In addition, we are preparing for the exploratory
measurements at the 12 o'clock intersection to search
for nonzero AN in inclusive photon production in theextremely forward direction, where sizable asymmetry
is predicted based on the large asymmetries observedin the Fermi lab. If AN is nonzero, we can use it tocommission the operation of the spin rotators, which
are to be fully installed next year. With spin rotators, the spin direction at collision points is going to
be completely transparent to the rest of the rings . We
should be able to confirm full longitudinal polarization
by observing the nonexistence of transverse asymmetry, AN.
The data analyses are in progress at the RHIC Computing Facility (RCF) and the PHENIX Computing
Center in Japan (CC-J) .ll) A database management
system has been carefully chosen to ensure identicalreferences of calibration constants at both RCF and
CC-J. 12 ) Duplication facilities for the data tapes arewell established at RCF , and weekly shipments of datatapes have been arranged . Detailed descriptions of the
progress of CC-J and the results from both RCF and
CC-J can be found in this volume.
Towards more precise know ledge of the hadron reactions using perturbative quantum chromodynamics, wehave been continuing global analysis of data from polarized lepton scattering especially in the area of error
estimation for the obtained parton distributions. 13 ) We
also started an involvement in BELLE collaboration in
KEK to determine any spin dependence in quark fragmentation functions .
References
1) M. Ishihara and G. Bunce: RIKEN Accel. Prog. Rep.
34, 227 (2001) .
2) K . Kurita et al.: RIKEN Accel. Prog. Rep. 35 , 226(2002) .
3) J. Tojo et al.: RIKEN Accel. Prog. Rep. 35 , 221 (2002).
4) O. Jinnouchi et al.: RIKEN Accel. Prog. Rep . 35 , 228(2002).
5) D. E . Fields: RIKEN Accel. Prog. Rep. 35 , 229 (2002).
6) H. Kobayashi et al.: RIKEN Accel. Prog. Rep. 35 , 232(2002) .
7) A. Taketani et al. : RIKEN Accel. Prog. Rep. 35 , 224(2002).

8) H . D. Sato et al.: RIKEN Accel. Prog. Rep. 35, 225(2002).
9) K. Okada et al. : RIKEN Accel. Prog. Rep . 35, 222(2002).
10) Y. Goto et al.: RIKEN Accel. Prog. Rep. 35 , 220(2002).

11) T. Ichihara et al.: RIKEN Accel. Prog. Rep. 35 , 236(2002).
12) S. Yokkaichi et al.: RIKEN Accel. Prog. Rep. 35, 238(2002).
13) Y. Goto et al.: RIKEN Accel. Prog. Rep. 35 , 188(2002).

217

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of neutral pion transverse momentum distributions
at yiSNN == 130 GeV Au+Au collisions
H. Torii,* A. Bazilevsky, H. En'yo, Y. Goto, K. Imai,* and N. Saito, for the PHENIX Collaboration
One of the proposed QGP signatures is the jetquenching effect. I) In the Quantum Chromo Dynamic(QCD) calculation, the scattered partons arising fromcollisions are predicted to lose greater energy in the
QGP matter than in the hadron matter. The hard
71"0 fragmented from the jet can be used as a probe
to detect the energy loss in the QGP matter. Below,
we present the result of 7[0 measurement at VS N N =130 GeV Au+Au collisions.
The PHENIX 2 ) experiment is one of four experiments being conducted at RHIC. In 2000, RHIC produced collisions of gold ions at beam energies of up
to 65 GeV per nucleon with 5 x 10 25 cm- 2 sec- 1 luminosity. The two photons decayed from 71"0 were measured by the PHENIX EMCa1 3 ) with -0.35 to 0.35
rapidity coverage. To identify photons, we applied
time-of-flight and shower profile cuts, which helped reduce the nonphoton background by a factor of 2 to 20
depending on the energy region. After combinatorial
background subtraction, and acceptance and efficiency
corrections,4) the 7[0 yields were obtained in different
centrality collisions.
Figure 1 shows the yield per event as a function of
PT for 60- 80% and 0- 10% centrality event data. In the
Peripheral (60-60%) and central (10%) nO data
•

I

.

. ,

-~··t--·+--·-·+-~···-!-·--·f·-·-t
!

!

1

t

i

i

I

I

i

i

. ---.-+. -.- ··-t-·-·~!···-·-·

I t ;

!,
i ! j
pHE~IX ~relhrlnaty_.

'-!-'' ~j---"1"~'-l -'- '1--~
1

i

;

'

Au+Au " SNN= 130 GeV•(h++h-)12• 11°

binary scaling----_.=._------_.":._. __':".. - --- --~- . -- .. -.--..-.--.--..-.--..--.-.-----.--,..-....
. ---- - .+ - -

• +

....

t
2

3

4

5

Pr- (GeV/c)
Fig. 2. 7r°(square) and (h + +h-) / 2(circle) ratio of yield per
event in the central to that in the peripheral Au+Au
collisions as a function of PT , with divided by (Nbinary)
for that class. The surrounding bands (shaded for 7r° 'S,
brackets for (h+ + h-)/2) are the quadrature sums of(i) the parts of the systematic errors on the spectra that
do not cancel in the ratio , and (ii ) the uncertainty in(Nb inary).

peripheral, the data shows consistency with the P + P
data scaled by the number of binary collisions (= 20),
which is determined using the Glauber model. Figure 2
shows the ratio of yield per collision in the central tothat in the peripheral, each divided by (Nbinary) . The
ratio in the PT lower than 2 GeV, which is dominatedby soft 71"0, obeys (Npartic ipant) scaling, so that the ratio
is obviously smaller than 1. In higher PT, the 7[0 ratioshows a significant suppression from (Nbinary) scaling.
The square shown in the figure is the ratio for charged
hadrons 5 ) which also indicates suppression.
In conclusion , we observed a significant suppressionof the 71"0 yield in central collisions relative to out expectation from binary scaling in higher PT, where thehard 71"0 from the jet dominates.
References

10-5u.u..LJ...LI.Ju.LL1.u..LJ..u..u.1..I..U..u...uJu.LL1.J.UJ..u..u.J..U.J..JLJ.1.U

o 0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

pT{GeVIcJ

Fig. 1. The yields per collision for 7r 0 as a function of PT
for 60- 80% (lower squares) and 0- 10% (upper squares)
centrality event samples with references (line) to theyield per collision in N+N collisions of 7r 0 scaled upby (Nb inary). The error bars indicate the quadraturesums of systematic and statistical errors, and bands ofreference indicate the uncertainty in the N + N reference
and in the determination of (Nbinary) .
Kyoto University

2181) X. N. Wang and M. Gyulassy: Phys. Rev. D 44 , 3501
(1991).
2) G. P. Morrison et al.: Nucl. Phys. A 638 , 565c (1998).
3) E. Kistenev et al.: Proc. 5th Int. Conf. Calorimetryin High Energy Physics, New York, USA, 199 4-9 ~ 10
(World Scientific, 1994) , p. 211 ; H. Torii et al. : RIKEN
Accel. Prog. Rep. 33, 168 (2000); H. Torii et al.: RIKEN
Accel. Prog. Rep. 35, 243 (2002).
4) T. Sakaguchi et al.: RIKEN Accel. Prog. Rep. 34, 261(2001).
5) K. Adcox et al.: nucl-ex/0109003, accepted to Phys.
Rev. Lett. 88 , 022301 (2002); G. David et al.: nucl-ex/
0105014.

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of the transverse energy distributions in Au+Au
collisions at y'SNN == 130 GeV
A. Bazilevsky, for the PHENIX Collaboration
The PHENIX detector l ) at the Relativistic Heavy
Ion Collider (RHIC) at Brookhaven National Laboratory, is designed to measure the properties of nuclear matter at very high temperatures and energy
densities and to search for new phenomena. Many interesting results were obtained from PHENIX experiment in the first RHIC run with Au-Au collisions at
2
y'SNN = 130 GeV. )Transverse energy (ET ) measurements enable excellent characterization of the nuclear geometry of a reaction on an event-by-event basis and are sensitive tothe underlying reaction dynamics. 3 )The present measurements of ET are made using
a part of the electromagnetic lead/scintillating tile
calorimeter 4 ) (EMCal). For ET measurements at midrapidity in the collider, the EMCal acts as a thin but
effective hadronic calorimeter. For example, charged
pions with PT ~ 0.35 GeV /c , kaons (PT ~ 0.64 GeV /c)and protons (PT :::; 0.94 GeV /C) - PT values which arenear or above (PT) for all 3 cases- stop (i. e., deposit
all their kinetic energy) in the EM Cal.
The raw spectrum of measured transverse energy,
E TEMC , in the fiducial aperture of the PHENIX EMCal for Au+Au collisions at y'S NN = 130 GeV isshown in Fig. 1 (upper scale). The lower scale cor-

'0

:! 10
-

4

e.> 1.5
1:~'4. 1~~:::-:;~~-;-;-~; •• U

~y.

"~0.5
~

Go)

~0.8

~

TT:r

T T

T

T

~i1~Y!Y!Y !H

~0.6

ii

.-PHENIX

~ 0.4
~

~0.2

0- WA98

3t
w

a)
0
0

> 1

100 200 300
Npart

~

0
0

b)
100 200 300
Npart

Fig. 2. (a) Transverse energy density per participantdET / dTJ 117=0 / N p a rt for Au + Au collisions at v'S N N =130 GeV as a function of N p a r t , the number of participants , compared to data from WA9S 7) for Pb+Pb collisions at v'S NN = 17.2 GeV. (b) PHENIX dET/dTJI17=o/
dNc h/dTJI17=o versus N p a r t , compared to WA9S.

responds to the hadronic dET / drJl17=o in the full azimuth. 5 ) For the most central 5% of the inelastic crosssection (dET / drJ 17 =0) = 503 ± 23 GeV.
Figure 2 (a) shows the transverse energy density
per participating nucleon. It grows faster with thenumber of participants Npart 6) than at SPS 7) keeping (ET ) / (Nc h ) at a constant value of approximately
0.8 GeV (Fig. 2 (b)). This indicates that the additionalenergy density is achieved mainly by an increase in particle production rather than by an increase in transverse energy per particle.
1

3

10

References
10
10

20

30

40 50 60 70
ET(EMC) (GeV)I,

o 100 200 300 400 500 600
dEr/dlll11 =o (GeV)
Fig. 1. The raw E T EMC distribution (upper scale) and total
hadronic dET / dTJ 117=0 (lower scale). The solid line is theminimum bias distribution; the dashed lines correspondto the distributions for the four centermost bins,6) 0- 5%
to 15- 20%.

1) D. Morrison for the PHENIX Collaboration: Nucl.
Phys. A 638 , 565 (199S).
2) W. A. Zajc et al.: nucl-ex/0106001; Nucl. Phys. A 698,
39 (2002).
3) For example, Proc. Quark Matter 19S4, edited by K.
Kajantie (Springer, Berlin 19S5); Proc. Quark Matter
19S7, edited by H. Satz, H. J. Specht, and R. Stock.
4) G. David et al.: IEEE Trans. Nucl. Sci. 43, 1491 (1996) ;IEEE Trans. Nucl. Sci. 45, 692 (199S).
5) PHENIX Collaboration , K. Adcox et al.: Phys. Rev.
Lett. 87, 052301 (2001).
6) PHENIX Collaboration, K. Adcox et al. : Phys. Rev.
Lett . 86 , 3500 (2001 ) .
7) WA9S Collaboration, M. M. Aggarwal et al.: Eur. Phys.
J. C 18, 651 (2001).

219

RIKEN Accel. Prog. Rep. 35 (2002)

Spin monitoring for first polarized proton collisions
Y. Goto, A. Bazilevsky, G. Bunce, H. En'yo, M. Grosse Perdekamp , O. Jinnouchi , H. Kobayashi,
K. Kurita, N. Saito, H. D. Sato,* A. Taketani , J. Tojo,* and S. Yokkaichi
In 2001 we start asymmetry measurements with polarized proton collisions at RHIC. By using transversely polarized beams, the left-right asymmetry (single transverse-spin asymmetry), AN = (O'L-O'R)/(O'L+
O'R) , is measured , and by using longitudinally polarized beams, the asymmetry of parallel and anti-parallel
cross sections (double longitudinal-spin asymmetry),
ALL = (0'++ - 0'+_) /( 0'++ + 0'+_), is measured. Although one advantage of the asymmetry measurements
is the cancellation of the detector and beam asymmetry, this leaves systematic uncertainty in final error
evaluation.
In the RHI C polarized proton collider, each bunchin the RHIC rings is filled independently so that thepattern of polarization direction for the bunches can bearranged to yield all possible spin combinations for thecolliding bunches. This enables successive measurements of parallel and anti-parallel cross sections in the
ALL measurement, and of angular distribution in the
AN measurement. It greatly reduces time-dependent
uncertainty.
In these measurements, bunch-by.,.bunch monitoringof beam conditions and crossing-by-crossing monitoring of collisions are indispensable. This is a new development which is not required in the heavy-ion collisions. First, by determining the bunch number of
each bunch, we can compare bunch-by-bunch information provided by the RHIC accelerator and the RHIC
polarimeter. 1) Polarization information from the polarimeter is one of the most primitive elements of theasymmetry measurements. The polarization direction
must be confirmed by comparing the intended polarization pattern provided by the accelerator and thepolarization values from the polarimeter. Another oneof the most primitive elements is the luminosity information. One method of the luminosity measurement isgiven as a product of the bunch currents of two rings,

Kyoto U niversity

220

the blue ring and the yellow ring, provided by the accelerator. This is an appropriate reference to comparewith the crossing-by-crossing scalers for the luminosity
measurement implemented on the global trigger board( "GL1-P board") of the PHENIX detector.
The GL1-P scalers are four types of 32-bit scalers foreach of the 120 crossings. The beam-beam counter,
the normalization trigger counter, the zero degreecalorimeter , and the electromagnetic calorimeter areplanned to be used for these four types of scalers. For
the luminosity measurement, these scalers should nothave asymmetry, because they are used to normalize
the number of events for the asymmetry measurement.
To confirm that these scalers have no asymmetry, orto determine the upper limit of the asymmetry, it isnecessary to compare four types of scalers with eachother.
In the luminosity measurement , we investigate theGL1-P scalers, level-1 and level-2 trigger 2 ) rates, bunch
current products , and the ratios of these values. Allof these are monitored crossing-by-crossing, and theirtime evolutions are tracked. We need to investigate
their stability, and define their acceptable range. One
useful data for these purposes is the crossing vertex
distribution.
All of these monitoring functions are implemented
in the PHENIX-standard on-line monitor program. It
checks whether all necessary information is ready, that
all of the functions are consistent, and how stable they
are, in order to maximize the given beam time of the
RHIC polarized proton collisions.
References
1) K. Kurita et al.: RIKEN Accel. Prog. Rep. 34, 229(2001); RIKEN Accel. Prog. Rep. 34, 234 (2001).
2) K. Okada et al.: RIKEN Accel. Prog. Rep. 35 , 222(2002).

RIKEN Accel. Prog. Rep. 35 (2002)

Final result of analyzing power measurement of proton-carbon
elastic scattering in eNI region at 22 Ge V / c
J. Tojo,*l I. Alekseev,*2 M. Bai,*3 B. Bassalleck,*4 G. Bunce,*3 A. Deshpande, J. Doskow,*5 S. Eilerts,*4
D. E. Fields,*4 Y. Goto, H. Huang,*3 V. Hughes,*6 K. Imai,*l M. Ishihara, V. Kanavets,*2 K. Kurita,
K. Kwiatkowski,*5 B. Lewis,*4 W. Lozowski,*5 Y. Makdisi,*3 H.-O. Meyer,*5 B. V. Morozov,*2 M. Nakamura,*lB. Przewoski,*5 T. Rinkel,*5 T. Roser,*3 A. Rusek,*3 N. Saito, B. Smith,*4 D . N. Svirida,*2 M. Syphers,*3
A. Taketani, T. L. Thomas,*4 D. Underwood,*7 D. Wolfe,*4 K. Yamamoto,*l and L. ZhU*lAnalyzing power, AN, for hadronic elastic scattering in the coulomb-nuclear interference (CNI) region
has been studied in order to probe the hadronic spinflip amplitude T5. 1 ) Recent theoretical developments in2T5 ) and requirements for high-energy proton polarimetry at BNL-RHIC3) motivated us to measure the AN
for proton-carbon (pC) elastic scattering in the CNI
region at 22 GeV j c. We carried out the experiment
BNL-AGS E950 in March 1999. The preliminary result is presented in Ref. 4. In this article, we report
the final result of the AN measurement.
Our method of identifying pC elastic scattering in
the CNI region detects only recoil carbons which havea very low energy ranging from 100 keY to a few MeV.
We developed the detector system consisting of twosymmetric left and right arms to measure the energy
and the time-of-flight (TOF) of recoil carbons. Eachdetector arm consisted of a silicon strip detector (SSD)
and a micro channel plate (MCP) assembly with a thincarbon foil. ' Details of the detector system, its performance and the experimental conditions are describedin Ref. 5.
Recoil carbon events detected using the SSD wereidentified by the mass reconstructed from both theenergy and the TOF. Recoil carbon events were selected with the 2.5-0' mass resolution cut dependent on
momentum transfer to determine the analyzing power.
Momentum transfer t (GeV jc)2 was determined fromboth the energy and the TOF, taking into account theweights of detector resolutions. The backgrounds ofa prompt event, target fragment and excited statesin the selected recoil carbon sample were estimatedto be 1- 13% dependent on momentum transfer. We
recorded 2.2 x 10 7 events of pC elastic scattering in
0.009 < -t < 0.041 (GeV jC)2 to determine the AN.
Beam polarization was independently measured
with the polarimeter of the experiment BNL-AGS
E925,6) based on the analyzing power of pp elastic
scattering at momentum transfer -t = 0.15 (GeVjc)2,
A}Y = 0.0400 ± 0.0048 (sys). The pp elastic scatter*1

Department of Physics, Kyoto University*2 Institute of Theoretical and Experimental Physics, Russia
*3
*4

*5
*6
*7

Brookhaven National Laboratory, USA
Department of Physics and Astronomy, University of New
Mexico, USA
Indiana University Cyclotron Facility, USA
Department of Physics , Yale University, USA
Argonne National Laboratory, USA

0.04

0.03

0.01

-0.01

0w........,0L...J...OO:'-:-':5,...",0L..l.0:-'-:-1L...J..O:-'-:-.0W.1-'::-5'"::'0-'::-.0":-'2-:-0"':'.0-:-25":-'0-:'-.-'::-'03-:'-0~.'='"03~5':-':0::'-.04':-'-:-'-:0~.04~5:-'::0L.J.0·5-t ((GeV/c)2)
Fig. 1. Analyzing power for pC elastic scattering in the CNI
region at 22 Ge V / c. Bars indicate statistical errors only.

ing was identified by detecting both scattered protons
and recoil protons. The beam polarization during theexperiment was PB = 0.407±0.036 (stat)±0.049 (sys).
The AN was determined as a function of t, using
the "square-root formula." The final result with thetheoretically fitted curve 2) is shown in Fig. 1. The
solid curve represents the fitted result including thestatistical and systematic errors. The dotted curvesindicate the I-sigma error band of the fitted result.
In summary, the AN for pC elastic scattering in the
CNI region at 22 Ge V j c was measured successfully. We
established the principle of the polarimetry at RHIC
using the CNI.
References
1) N. H. Buttimore et al.: Phys. Rev. D 59, 114010 (1999).
2) B. Z. Kopeliovich and T. L. Trueman: Phys. Rev. D 64 ,
34004 (2000).
3) Proc. Workshop on Hadron Spin-Flip at RHIC Energies, Vol. 3, edited by T. D. Lee (RIKEN BNL ResearchCenter, New York, 1997).
4) J. Tojo et al.: RIKEN Accel. Prog. Rep. 34, 236 (2001).,
J. Tojo et al. : AlP ConL Proc. 570 , 790 (2001).
5) I. Alekseev et al.: RIKEN Accel. Prog. Rep. 33, 170(2000) .
6) K. Krueger et al.: Phys. Lett. B 459, 412 (1999); C. E.
Allgower et al.: submitted to Phys. Rev. D.

221

RIKEN Accel. Prog. Rep. 35 (2002)

Asymmetry measurement of charged hadrons at PHENIX
K. Okada, Y. Goto, N. Saito, H. En'yo, M. Grosse Perdekamp, K. Barish,* W. Xie,* and B. K. Nandi,*
The first collisions of polarized proton beams will occur at RHIC in December 2001. Using these collisions,longitudinal spin asymmetry, ALL, of charged hadrons
will be measured in order to investigate gluon polarization. As shown in Fig. 1, ALL is expected to be nonzero in the high-transverse-momentum region. 1) This
report describes the trigger scheme of the PHENIX
detector system for selecting charged hadrons.
There are two levels of trigger, level-1 and level-2,
in the PHENIX detector system. The level-1 trigger
comprises signals of "fast" detectors which have fast
response. The charged hadron trigger uses signals of
an electromagnetic calorimeter (EM Cal) . Due to therequirement of a certain threshold value of deposit energy in the EMCal, not only charged hadrons but also
electrons, photons, and anti-neutrons are selected. The
level-2 trigger 2 ) analyzes events in the event builder,and select events by using both "fast" and "slow" detectors. One of the functions of the level-2 trigger is analyzing the drift chamber (DC) data. Low-momentum
charged particles which have a large curved trajectoryand neutral particles (,)" fi) are rejected.
By assuming a beam luminosity of 5 x 1030 cm- 2 sec- I ,the proton-proton collision rate is 250 kHz for a total cross section of 50 mb. According to the experience of heavy-ion collisions, the bandwidth of the event
builder in the proton collisions will be limited to 3 kHz
by performance of the sub-event buffer (SEB). Since
we expect that a 1 kHz bandwidth will be allocated tocharged-hadron events, a rejection power of 250 needs
to be achieved in the level-1 trigger. From a detector simulation based on GEANT 3 ) with a PYTHIA 4)<t: 0.04•••••.........

00: ._-0 .02 0

GS95-NLO-A
GS9,)-NLO-8.~;- ~::;~!~~~:::~~~~;-:""T:=- r
2

3

4

PT (GeV/c)

Fig. 1. Asymmetry of charged hadrons estimated by theuse of various gluon polarization models. Statisticalerrors are shown by assuming an integrated luminosityof 5 p b - 1 and a polarization of 50%.

222

pip yield

IlJ·- -----.---.:.· ....-.... -e .. miriimum-bia~··- ..·.. ····---..·--.. ··~--- .. -... _-

~10'0

'1:1

t

109'--+,......./-1..r-l:~ thr.=O.75Ge\(,#prescaIe=3-----------.-!......--.---. .. -thr~=O.25Ge¥y#pr~i • mililimum bi~s,#presc~Ie=1

10' Fe'=t::=*==I~- ........... ~ ........... -,1---0;15GeV·~af8=3··1i'9·--b

____

:

~

7

10

itself* O.$ev,#pre.cale=1,tr9-by itself: ~ : =~~~~~f~~~-:
~

10

o

2

6

10
pT[GeV/c)

Fig. 2. Thansverse momentum (PT) spectrum of 1T+ yield inthis period of polarized-proton collisions. Stars indicate
final-number evaluation of 1T+.

event generator, the rejection powers of the level-1 trigger are estimated to be 189, 89, and 5 by requiring deposit energies in the EMCal of 0.9 , 0.75 and 0.25 GeV ,respectively. A rejection power of 250 will be achievedby setting the threshold value at slightly higher than
0.9 GeV. The next hurdle comes from the speed of data
strage which is limited to 800 Hz. The level-2 trigger
is required to decrease the event rate to 200 Hz as anallocation of charged-hadron events. The required rejection power is 5. This is estimated by simulation
with single muons. For the events that survived thelevel-1 trigger with a threshold value of 0.9 GeV, therejection power is 5.9, which satisfies the requirementof the level-2 trigger.
Figure 2 shows yield estimation of 7r+ 's in this periodof polarized-proton collisions, where "trg_by _itself"means further event selection by off-line analysis to remove trigger bias after the trigger selection describedabove. These show a final-number evaluation of 7r+ inthis period. Statistical errors in Fig. 1 reflect the final
numbers. Many sufficiently charged hadrons should
be collected to distinguish various models of the gluon
polarization with 5 pb- I total luminosity.

567

h+ Asymmetry

University of California, USA

I

References
1) A. Bazilevsky et al.: RlKEN Accel. Prog. Rep. 34, 243(2001).
2) PHENIX Collaboration: submitted to Nucl. lnstrum.
Methods Phys. Res.
3) CERN Program Library Long Writeup W5013 (1993).
4) T. Sjostrand: Comput. Phys. Commun. 82, 74 (1994).

RIKEN Accel. Prog. Rep . 35 (2002)

Parity violation at RHIC in jet production
J. Murata
The author developed a simulation tool POLBY as
a plug-in program for PYTHIA in the year 2000, aiming at studies of parity violation via new interaction beyond the standard mode1. 1 ,2) Using PYTHIA+ POLBY, the Drell-Van process was studied as afirst step. Although the Drell-Van process is simple
and clean, we need to examine the jet production process, which has a large production cross-section because of the small yield in the Drell-Van process. In
case of the Drell-Van process, all the interactions weneed to consider are the standard model ry* / ZO, thecontact interaction, and their interference terms. In
contrast, we need to take into consideration QeD '\1*
o
±
..
' I ,
Z , W , the contact mteractIOn, and their complex
interference terms for the jet production process. In
PYTHIA, above processes must be generated as independent subprocesses. This restriction causes a severe
problem when we consider the interference terms between different subprocesses in PYTHIA because interference effects cannot exist interference if we distinguish the subprocesses. In case of the Drell-Van
process, we can use single subprocess, therefore, theinterference effects can be automatically included.
Recently, POLBY was modified in order to restore
quantum mechanics in the PYTHIA simulation for thejet production. In the modified POLBY, a hadronic
spin asymmetry, A, is estimated using event-by-event
asymmetry weight factor W(A); A = Li-event Wi(A)""Li=event
H ere, th e events are generated by PYTHIA subprocesses. The "interference correction" can be performedby Wi(A) ~ Wi(A) x Lprocess=QCD, Wec:,k,EM,CT uprocess
u QCD

•

Then, if we use pure QCD subprocesses for the
PYTHIA event generation, contributions from otherprocesses on the asymmetry can be taken into accountby summing up all of the processes. The mean valueof the W(A) distribution gives us the final hadronic
spin asymmetry. Due to the correction, the W (A) distribution is distorted and we can obtain the corrected
asymmetry from the distorted distribution. As an example, parity violation around the Jacobean peak is
examined. In Fig. 1, we can confirm the large contribution from the interference term on the parity violation
around the Jacobean peak. The subprocess-separated
plot in Fig. 1 shows that the qq' ~ qq' subprocess
dominates the parity violation at the W peak.
The simulation results can be compared with theoretical calculations (Fig. 2). The results from thepresent study and those of Virey l,3) are roughly
The small differin agreement with each other.
ences can be understood by the difference in the
choice of the polarized PDFs. Regarding the disagreement at the Jacobean peak, it can be under-

ITotal PV Asymmetry •iProcel. separated PV Asymmetry •

0.005

0.05

Jl.jJ;
-.J-=
W

0.003

Z

"weighted~ ~~ "unwelghted

0.002~: ~~:;;~,(~)
0.01

0.001

Around Jacobean Peak~qq'--+ qq'
qq'--+(ZW)
qq--+qq(Z)qq'

qq'--+ qq'(W)
40

42

44

46

48

50
52
54
JelptlGeVJcl.0,01""::3:-"."':!:38~40'-'-'-!:-'2"":',L44~'-'-'-6~.L..,8'""'""SO-'-'--'--'-S2............L..
S•

JeIPt{GeV/e)Fig. 1. Fine structure of the Jacobean peak on parity violating spin asymmetries.

PV Asymmetry A :' for Inclusive Jet

Fig. 2. Comparison with other theoretical calculations.

stood to be a binning effect. Virey estimated theasymmetry as A
(Et = 40 Ge V), while we estit'
r40GeV+.6. A PV ( )r40GeV+.6.
ma e It as J40GeV
LL .x dx/ J40GeV
dx, where~ = 2 Ge V. There can also be a difference regarding
the treatment of the interference terms . If we compare the present results and Ellis' NLO calculation(JS = 300 GeV),4) we find that they show similar results at the Jacobean peak. Ellis uses the same GSA
pol-PDF as that used the present study.
In order to use PYTHIA + POLBY as a standard
model reference,the NLO calculation is indispensable.
The NLO effect is difficult to take into account in an
event generator. The situation is similar to the treatment of the interference. One large assumption for
the interference correction is that, pure QCD process(generated events) and other processes must have thesame final states. In principle, NLO correction using
similar cross-section correction should be applicable.
Theoretical calculations in NLO are now under way. 4)
We should and will be ready to examine experimental
data from RHIC in the near future.

ry

References
1) J. Murata: RIKEN Accel. Prog. Rep. 34, 246 (2001)
and references therein.
2) J. Murata: in press in Czech. J. Phys. 52, Suppl. A(2002); hep-ex/Oll0069 .
3) P. Taxil and J .-M. Virey: hep-ph/0109094.
4) J. Ellis, S. Moretti, and D. A. Ross: hep-ph/0102340.

223

RI KEN Accel. Prog. Rep. 35 (2002)

Operation of the PHENIX muon identifier
A. Taketani, V. Cianciolo,*1 H. En'yo, G. Gogiberidze,*2 A. Glenn,*2 K . Imai ,*3 M. Ishihara,
L. Kotchenda,*4 Y. Mao,*5 J. Newby,*2 K. Read, *I,*2 N. Saito, H. D. Sato,*3
S. Sorensen,*2 L. Villatte,*2 G. Young,*1 for the PHENIX Collaboration
The muon identifier (M uID) of the PHENIX experiment has been installed. 1 ) We commissioned a part ofthe south MuID in 2000. 2) The full south muon arm
has been commissioned with Au-Au VSNN = 200 GeV
as well as other PHENIX subsystems. This article describes the gas system and high-voltage (HV) system
operations. We have been correcting data from thesouth arm which consists of the MuID and the Muon
Tracking detector.
The muon arm is expected to measure the gluon polarization by identifying J /'I! as a part of this year's
RHIC spin program. 3) The major role of the MuID
detector is to identify the muon in the trigger and reconstruction programs. 4) The JVluID covers 10 to 35
degrees in () and 360 degrees in ¢ at 7 meters from theinteraction point with the sandwiching of five absorbersteel plates and proportional tubes. 5) The detectors arelocated in the forward and backward regions, so-calledsouth and north arms.
Each chamber of the MuID panels is separated into
two gas volumes. 1) One is the primary volume that include anode wires. The CO 2/i-C 4H lO (92.5/7.5 percent) gas flows into it. The south arm has a volumeof 25 m 3 as the primary volume. The flow rate is one
exchange volume per day and half of the gas is recirculated after being checked for the O 2 and H 20 contamination. The another volume is the secondary volume
which surrounds the primary volume. It is filled with
the N2 to keep the electronics clean and dry. Also, it
is useful to dilute the flammable gas component in thecase of leakage from the primary volume. The N2 flowrate is 40 l/minute for the south arm. No N2 are flowed
into the north arm secondary volume . The north arm
primary volume has been flowed with N2 to maintainthe chamber in good condition during this year. The
flow rate, recirculation rate, chamber head pressureand outlet pressure are monitored by a computer controlled system. If a readout value exceeds a certain
threshold, appropriate action(s) will be initiated automatically, as well as warning issued to the PHENIX
shift crews . For example, if the chamber head pressure is too high , then the gas flow into the primaryvolume will be shut off. The gas system is checked by
the shift crew every four hours. The gas system has
been in the stable operation since May 2001. A few
parts have failed during the operation, but they were
*1
*2

*3
*4

*5

224

Oak Ridge National Laboratory, USA
University of Tennessee, USA
Kyoto University
State InterPhysica, Russia
Beijin University, China

Fig. 1. Monitor display.

replaced or recalibrated within the minimum shutdown
period. All readout values are logged in the database,which is useful for monitoring and diagnostic.
There are 300 HV channels for the south arm. Eachchannel can be controlled individually. Parameters to
be controlled are target voltage, trip current limit, andramp up/ down rate. It is difficult to control these300 HV channels manually, therefore we use a semiautomatic control system. The system consists of a
GUI part and a control program part which receives
the setting parameters from the G UI and communicates with the HV power supply. Also , the GUI part
ontains the status of the each channels, and displaysthem. Figure 1 shows the monitor display. Each squarebox corresponds to an individual HV channel and indicates the measured voltage and current by values andstate such as stable, trip, ramp, and high current bycolor. The control program has five major functions .
(1) Turn on/off the power supply. (2) Recover fromtrip. (3) Log HV status for offline study. (4) Protect from frequent trips and sparks . (5) Protect fromsteady high current due to the beam condition. Functions (4) and (5) can be adjusted according to the datafrom (3) for stable operation. The HV system has been
operated since July 2001.
References
1) A. Taketani et al.: RIKEN Accel. Prog. Rep. 33 , 166(2000) .

2) A. Taketani et al.: RIKEN Accel. Prog. Rep. 34, 230(2001).
3) H . D. Sato et al.: RIKEN Accel. Prog. Rep. 34, 244(2001).
4) Y . Mao et al.: RIKEN Accel. Prog. Rep. 34 , 242 (2001) .
5) Y. Mao et al.: RIKE Accel. Prog. Rep. 3 0 , 36 (1997).

RIKEN Accel. Prog. Rep. 35 (2002)

Performance of the PHENIX muon identifier
H. D. Sato,*l V. Cianciolo,*2 H. En 'yo , A. Glenn,*3 G. Gogiberidze,*3 T. Ichihara, K. Imai,*l K. Kurita,
Y . Mao,*4 J. Newby,*3 K. Read,*2,*3 N. Saito, S. Sorensen,*3 A. Taketani, L. Villatte,*3 Y. Watanabe,
S. Yokkaichi, and G. Young,*2 for the PHENIX Collaboration
A part of the South Muon Identifier (MuID) in
the PHENIX Muon Spectrometer l ) was operated lastyear. 2) This year the entire South MuID has been operated successfully for Au + Au nucleus collisions at
VSNN = 200 GeV.3)
We have implemented the so-called NIM-Iogictrigger 4) to obtain cosmic ray data for calibration purposes. Using the cosmic ray data, the chamber efficiency was found to be approximately 95% for eachplane. HV excitation curves for efficiencies were measured and goo~ plateaus were found between 4300 V
to 4500 V, in which range the actual operation voltages are set. Discriminator-threshold curves were alsomeasured which show no threshold dependence for efficiencies between 70 m V and 120 m V. The operationthreshold is set to 90 m V. Below 70 m V , noise becomessignificant. Using cosmic rays, we have also confirmedthat the chamber geometry is as we expected, by considering the residual distributions for all channels.
The entire South MuID has successfully been operated for Au + Au collisions at VS N N = 200 Ge V since
July 200l. There have been no major problems in
the gas system, high-voltage supplies or online-monitor
software. 5 ) Figure 1 shows the correlation between thenumber of hits in MuID and the charge sum in the

beam-beam counter which covers 3.1 < 1'1]1 < 4, where'1] is the pseudo-rapidity of a charged particle. This
good correlation indicates that MuID is finding collisions.
Figure 2 shows the comparison of hit rates for eachchannel on the one-panel plane between real data andthe simulation. A part of the simulation data was produced using the large LINUX farm in the RIKEN Computer Center in Japan (CCJ). They agree reasonably
well. The numbers of reconstructed roads were also
compared and again real data and the simulation agree
well, which indicates that we understand the detector
satisfactory and there is no major concern regarding
either hardware or software.

...c 10

-1

CD

>

~
...

-..
:f
0

·2

10

CD

.a

E
::::I

Z

10-3

100

§2000

<I)

200

300

400

Channel Vertical Position (cm)...&1800
as
i5 1600

Fig. 2. Number of hits per event for each channel on the
4th horizontal plane, upper West panel. Lines indicate
simulation and points indicate real data with statisticalerrors.

g1400
III

1200
1000
800

References

600

50

100

150

200

250

300

350

MulD Total Hits

Fig. 1. Correlation between the total number of hits in
M uID and the charge sum in the beam- beam counter(BBC).
*1
*2
*3

*4

Kyoto University
Oak Ridge National Laboratory, USA
University of Tennessee, USA
China Institute of Atomic Energy, China

1) http://www.phenix.bnl.gov /2) A. Taketani et al.: RIKEN Accel. Prog. Rep. 34, 230(2001).
3) H. D. Sato for the PHENIX Collaboration: 1st Joint
Meet. of the Nuclear Physics Divisions of APS and JPS ,Hawaii, USA , Oct. (2001).
4) K. Read for the PHENIX Collaboration: 1st Joint
Meet. of the Nuclear Physics Divisions of APS and JPS ,Hawaii, USA , Oct. (2001).
5) Detailed description of MuID infrastructure can befound in A. Taketani et al.: RIKEN Accel. Prog. Rep .
35 , 224 (2002) .

225

RIKEN Accel. Prog. Rep. 35 (2002)

RHIC pC CNI polarimeter readout
K. Kurita, H. Spinka,*l D. Underwood,*l H. Huang,*2 Z. Li,*2 W. MacKay,*2 G. Mahler,*2 Y. Makdisi,*2
W. McGahern,*2 S. Rescia,*2 T. Roser,*2 G. Bunce,*2 G. Igo,*3 W. Lozowski,*4 1. Alekseev,*5 V. Kanavets,*5
D. N. Svirida,*5 H. En'yo, K. Imai, *6 J. Tojo,*6 N. Saito, D. E. Fields,*7 S. Dhawan ,*8 and V. Hughes*8
Polarized proton acceleration commissioning is under way at the Relativistic Heavy Ion Collider (RHIC)
in Brookhaven National Laboratory. Polarimetry was
one of the biggest issues in polarized acceleration sinceno technique was available when the polarized proton
collision was planned at RHIC. We have led an R&D
effort to achieve polarimetry and established a technique of monitoring the RHIC proton beams utilizing
proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region. 1)
The CNI polarimeter determines the left-right asymmetry of the number of carbons scattered from anultrathin microribbon carbon target 2) by the protonbeam. This target allows low-energy recoil carbons (aslow as 100 ke V) to come out of it and also minimizes
the increase in beam emittance during the measurement. Although our target is the thinnest available,
the carbon counting rate estimated for the full luminosity of the RHIC proton beam is of the order of
10 MHz. The CAMAC FERA-based data acquisition
system that was used to confirm the feasibility of the
CNI polarimeter in the RHIC ring with a much reduced number of beam bunches and intensity is notapplicable since the dead time of the system is excessive and the system takes too long to accumulate sufficient statistics. To be able to measure the polarization
at full luminosity without disturbing the beam, a newreadout scheme is necessary. The statistics we needfor one polarization measurement typically comprises
twenty million events.
The requirements of the RHIC pC CNI polarimeterreadout are the following.
• dead-time-Iess system operating at a 10 MHz
event rate
• capability either to store or process 20 M events
per measurement• capability to reject overlapping events which may
give rise to false asymmetry

successfully confirmed using actual CNI recoil carbon
signals. Figure 1 shows a typical waveform from thecarbons.
The next step is how to deal with the huge amountof data flow in the order of 100 MB/sec. We have beendeveloping two ways to deal with this issue. One way
is to select carbons using memory look up table created to cut out the carbon kinematics (pulse height
and the arrival time with respect to the RHIC RF
clock) realized on Xilinx Vertex100 FPGA. During
the last commissioning, we found that we can extract
background-free carbons by applying only kinematicconstraint. After the carbon identification is carriedout, the number of carbons is counted with appropriate scalers programmed in the FPGA. WFD works
as a selective scaler, thus it is not necessary to store
large amounts of data (waveforms). The schematic diagram of the FPGA program is shown in Fig. 2. It isan elegant way to handle large amounts of data, butsystematic errors must be evaluated using other methods.
The other way to deal with the data flow is to store
all waveforms utilizing on-board random access memory (RAM). Xilinx provides a RAM driver library witha FPGA chip and the same software tools can be used
to configure it. In the new version of the WFD, 128 MB
DRAM is implemented on each module which takes
care of four channels. Each waveform takes approximately 25 bytes and 20 million events with a total of 12
WFD modules (48 Si channels), which correspond toa total of 500 MB and approximately 40 MB per WFD
board. Therefore, 128 MB DRAM on each module ismore than sufficient for our application. We take advantage of the fact that the event rate is very highbut the total amount of data to be buffered per measurement is sufficiently small to handle with the current RAM technology. This is the only method which

It was found that the 8 bit and 420 MHz waveform
digitizer developed at Yale University satisfies all theabove requirements. Therefore , a prototype was fabricated for the last polarized proton commissioning andthe functionality of the waveform digitizing part was
*1
*2
*3
*4
*5

*6

*7
*8

226

Argonne National Laboratory, USA
Brookhaven National Laboratory, USA
University of California , Los Angeles, USA
Indiana University, USA
Institute for Theoretical and Experimental Physics, Russia
Kyoto University
University of New Mexico, USA
Yale University, USA

Fig. 1. A typical waveform from eNI recoil carbons.

Fig. 2. Schematic diagram of the FPGA program.

allows us to analyze the waveforms and extract theasymmetry from them offline.
Thus far , the online processing FPGA program has
been run and confirmed to extract the correct amplitude and the timing from waveforms. A memoery lookup table will be created and tested at the beginning of
the commissioning which will start in December, 200l.
On the other hand, the RAM is incorporated in thecurrent WFD hardware design but is still to be configured softwarewise. Therefore, we plan to debug the
FPGA program with a limited number of waveforms
which are available in the FPGA buffer. We can perform all necessary checking of the system except extraction of asymmetry directly from the full data set(waveforms) offline.
The commissioning of the full-configuration RHICpolarized proton acceleration starts from December,2001 and the WFD performance will be thoroughly
investigated. Upon successful commissioning, the firstpolarized proton collider experiments will be started
at RHIC.
References
1) K . Kurita et al.: RIKEN Accel. Prog. Rep. 34, 229(2001).
2) W. R. Lozowski and J . D. Hudson: Nucl. Instrum.
Methods Phys. Res . A 303, 34 (1991).

227

RIKEN Accel. Prog. Rep . 35 (2002)

Results from RHIC polarimeter commissioning run 2000
O. Jinnouchi, K. Kurita, J. Tojo,*l N. Saito, I. Alekseev,*2 D. N. Svirida,*2 D. E. Fields,*3 C. Bunce,*4
T. Roser,*4 H. Huang,*4 W. Clenn,*4 H. Spinka,*5 Z. Li ,*4 W. Mackay,*4 C. Mahler,*4 Y. Makdisi,*4W. McCahern ,*4 S. Rescia,*4 T. RUSSO ,*4 C. Igo ,*6 W. Lozowski,*7 V. Kanavets,*2 D. Koehler, *3
D. Brown,*8 S. Dhawan,*9 V. Hughes ,*9 R. Krisst ,*9 H. En'yo, K. Imai ,*l A. Deshpande,
Y. Coto, M. Ishihara, T. Ichihara, A. Taketani, and Y. Watanabe
In September 2000 , spin commisioning using the polarized proton beam was carried out at the Relativistic
Heavy Ion Collider (RHIC).l) The aim of this commissioning was to assess the feasibility of polarized proton
acceleration and its polarization measurement for thep-p runs which are going to start from this year.
In order to accelerate the polarized proton, one setof helical dipole magnets called Siberian snakes 2) was
installed in the RHIC blue ring. In this case , the stablespin direction would be horizontal when a single snake
turned on adiabatically after injection. The pC CNI
polarimeter 3) was also installed in the same ring (atthe 12 o'clock position). A very thin carbon target
was placed at the beam position. The recoiled carbons
from pC elastic scatterings can be identified by the
relation between their energies and the t ime of flight(TOF). Four Si detectors each equipped with 8 strips
were installed obliquely, 15 em from the target.
The fast analysis yielded the following results ,(1) A vertical spin direction was observed with thesnake off, with significant size.
(2) A horizontal spin direction was observed when
the snake was turned on.
(3) Horizontal spin rotation was observed throughthe acceleration from injection energy.
(4) No asymmetry at Cry ~ 61.3 was observed.
In the upcoming spin run, the quick polarization measurement is required. The fast data acquisition with ascaler (counter) is our solution. It is realized with thewave form digitizer (WFD) which counts the selectedcarbon signals on board. Developing on the accurate
and reliable algorithm for asymmetry calculation is urgent and indispensable, therefore further detailed analysis of the commissioning data is strongly needed.
Our analysis is based on mass particle identification.
The simultaneous kinematic fit to Q and carbon loci in
the ADC vs TOF distribution yields energy scale andTO parameters for each Si strip. Carbon and Q masses ,slewing effect, the distance between the target and theSi, and the dead layer depth on the Si surface have
*1

*2
*3
*4
*5

*6
*7

*8
*9

228

Kyoto University
Institute of Theoretical a nd Experimental Physics, Russia
University of New Mexico, USA
Brookhaven National Laboratory, USA
Argonne National Laboratory, USA
University of California, USA
Indiana University, USA
New Mexico State University, USA
Yale University, USA

RHIC Spin C omm is.lo ....dnQ 2000 p,.. limi naryFig. 1. -t dependence of the asymmetries, being normalized with the analizing power from E950 result.

been measured and constrained. The energy and TOF
values are converted into the mass. Mass distribution
shows a clear separation of carbon from Q implyingthat extremely small Q contamination is expected.
It is also important to confirm that the measured
carbons are elastically scattered-off. We investigate
this from two aspects. The first is to see the slope parameter of the differential cross section as a function of
the transferred momentum squared, -to The obtained
value is consistent with the elastic value from the otherexperiments. The second is to observe the energy dependencies of the recoiled carbon angles. The energy
vs angle distribution well fits with the kinematic curveof the elastic one; inelastic scattering (4.4 MeV excitation state) has been clearly excluded. From the detector resolution study, the energy resolution is at most
10% for the whole energy range , so that it is reasonable
to define the -t value only from energy. This is a profitable discovery as the WFD defines the asymmetry as
a function of the energy this year. The raw asymmetry is obtained as a function of - t (Fig. 1). With theanalyzing power determined from the E950 result,4)
the polarization during the spin commisioning is extracted. The preliminary result using the typical run
set yields P = A(t)/AN(t) = 0.181 ± 0.029 , which has
been depolarized after the ACS extraction (P = 33%) .
From these experiences and results, we are sure to
be successful in the upcoming spin run this year.
References
1) K. Kurita et al. : RIKEN Accel. Prog. Rep. 34 , 229(2001).
2) W . W . Mackay et al.: DESY-PROC-1999-03, p. 163.
3) K. Kurita et al.: RIKEN Accel. Prog. Rep. 34, 234(2001).
4) J. Tojo et al.: RIKEN Accel. Prog. Rep. 34 , 236 (2001).

RIKEN Accel. Prog. Rep. 35 (2002)

PHENIX muon tracker: Construction, year-2 operation andpreliminary data analysis
D . E. Fields*
The design of the PHENIX detectors has been optimized for a broad dynamic range from central A-A
collisions (focusing on the generation , detection, andsubsequent characterization of the quark-gluon plasma(QGP)) to p-p collisions (measuring the helicity distributions of flavor-separated quarks and antiquarks,
as well as the first direct measurement of the gluon
polarization in the nucleon). In particular, the experiment will be able to identify exclusive leptons , photons,
and high-PT hadrons with good momentum and energy
resolution, as well as very accurate particle identification. In A-A collisions, rare probes are particularly
intriguing, since they address some of the most pressing questions in heavy-ion physics, such as charmonium production and suppression and direct photon
production. More details and current information on
the PHENIX experiment can be found in Ref. 1, anda concise recent summary of the planned RHIC spin
program can be found in Ref. 2.
Muons are an important probe of the physics forboth the heavy ion and the spin program. The mostinteresting muons originate from the following sources :vector meson (J /"iJ!, Y, etc.) decays, Drell-Yan decays,
W -decay, and heavy flavor (c and b) meson decays.
The muon tracking system (see Fig. 1) will enablemeasurement of the momentum and direction of flightof muons . This information will be used to reconstruct
the invariant mass of dimuon pairs originating fromthe vertex. Mass resolution for the decay pairs fromthe Upsilon dictates a position measurement precisionof 100 microns at each tracking station. In order toachieve this , cathode strip chambers (CSCs) with ahoneycomb structure were chosen as the baseline design for the PHENIX muon tracker stations 1 and 3.
Because of lower scattering length restrictions at station 2, the honeycomb structure was replaced by mylar foils , held taut by aluminum frames. The basic
mechanical structure of a CSC is that of a conventional proportional wire chamber. However, rather
than reading out the anode wires to obtain position
resolution, a precise position coordinate is determinedfrom the induced signal on cathode strips perpendicular to the anode wires. A detailed description of the
final chamber design can be found in Ref. 3.
The South Muon tracking chambers were completed
in the spring of 2000. Figure 2 shows the completed
station one detectors being surveyed on a test wall after completion. The chambers were installed into themagnet succesfully, integrated into the entire PHENIX
system and are operating well as the first 200 Ge V
University of New Mexico, USA

STATION 3
MUON-IDENTIFIERREGIONSTATION 2

STATION 1

SOUTH MUON MAGNETAND TRACKING DETECTORS

Fig. 1. The South Muon ARM tracking spectrometer.
Muons from the intersection region, to the right, intercept the station 1, 2, and 3 detectors and proceed tothe muon identifier detectors to the left (not shown).

Fig. 2. Station 1 is built in four quadrants but is electricallydivided into octants to match the oct ants of stations 2
and 3.

Au-Au data are being recorded . The operation of
the detectors includes monitoring of the gas system,
the high voltage systems, the low voltage system (forthe front-end electronics (FEE)), the alignment system (for precise positioning) and finally the gain andpedestal calibrations, taken and recorded on a daily basis. This complex task including the monitoring of theperformance of over 20,000 cathode readout channels
has been developed in phases to achieve the smoothrunning operation mode now in place.
Early test results from the chambers are very en-

229

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Arm.
South Muon
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Fig. 3. COsm

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References
ix.bnl.gov
WWW'Phen.
1) http: //h / 00 07 21 8
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et
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Published

IX3) P H E N

N IM , to be

RIKEN Accel. Prog. Rep. 35 (2002)

Geometry alignment of PHENIX Muon tracker
N. Kamihara,*l H. Kobayashi, S. Batsouli,*2 M. L. Brooks,*3 N. Bruner,*4 D. E. Fields,*4 D. M. Lee,*3
M. X. Liu,*3 J. Murata, N. Saito, T.-A. Shibata,*l W. Sondheim,*3 and A. Taketani
The PHENIX Muon arm has an important role inboth spin and heavy-ion physics at RHIC. We canmeasure several features of the proton spin structureusing the muon probe. For example, gluon polarization
can be measured by the J / 'lj; and open heavy flavor
decay. Quark polarization can be measured by the
Drell-Van process and W boson production. The Muonarm has capabilities to identify muons and measure
their momentum. It covers the forward and backward
region, which is 1.1::; I rJ I ::; 2.4, the so-called south
and north arm.
The PHENIX Muon consists of muon a identifier(MuID), muon magnets and a muon tracker (MuTr).
A MuTr detector is located on the muon magnet.
The muon magnet has a radial field and the incident
charged particle bends on the plane which is perpendicular to the beam pipe. The MuTr detector consists of acathode strip chamber. There are three layers of chambers which are separated 116 cm and 163 cm along thebeam. Thus good alignment of each chamber positionis essential for obtaining proper momentum resolution
as well as calibration of each cathode strip.
One of the major goals of muon arm physics is to
identify the quarkonium decaying into the J.l+ J.l-, suchas J / 'lj; and Y. Particularly for Y , it is interesting todistinguish between the different mass states (Y(lS)(9.46 GeV) from Y(2S+3S) (10.36 GeV)) to investigate
Quark-Gluon Plasma. Thus, the required momentum
resolution is 1 percent. The typical muon momentum
from Y is 10 GeV. The displacement of the muon trackin the middle layer in the MuTr detector due to themagnetic field is 1 cm. Thus, we need 100 J.lm positioning accuracy relative to the other MuTr layers. Multiple scattering dominates the mass resolution of the
J /'lj;. The required position resolution is 300 J.lm forseparating J / 'lj; from 'lj;'.

*1

MuTr mechanical installation in the PHENIX experimental hall was completed by the end of last year.1)
The accuracy of the mechanical installation between
stations is of 1 mm order. Alignment is important forhigh position resolution. Test chamber resolution using a prototype front-end electronics (FEE) at LANL
in 1999 was (]" = 165 J.lm; the position resolution wasdetermined by a simple center-of-gravity method. 1 ,2)
An Optical Alignment System (OASys) monitors thesecond-layer position relative to the first and third layers every hour. 3) The relative accuracy of the The
OASys is about 20 J.lm. The OASys can be used forshort-term correction. The straight-track method will
give us the reference alignment based on the tracking
information.
We obtained many zero-magnetic field run data inbeam collision time. Tracks of the charged particles are
expected to be straight lines. The straight line is fitted
to hits in single layers which have four to six cathodeplanes depending on the layer. The width of the residual distribution reflects the chamber spatial resolutionof each hit and the average value corresponds to thegeometrical accuracy of each layer construction. Afterobtaining a straight track segment in each layer , threesegments are fitted in one track. The average of the
fit residual reflects the relative position of the layers.
Calibration and analysis are under way and a position
resolution of 100 J.lm is expected for the chamber.
References
1) J. Murata et al.: RIKEN Accel. Prog. Rep. 34, 237(2001).
2) J. Murata et al. : RIKEN Accel. Prog. Rep . 33 , 165(2000) .
3) H. Kobayashi et al.: RIKEN Accel. Prog. Rep. 35 , 232(2002).

Tokyo Institute of Technology*2 Columbia University, USA*3 Los Alamos National Laboratory, USA*4 University of New Mexico, USA

231

RIKEN Accel. Prog. Rep . 35 (2002)

First commissioning of the PHENIX south muon tracker:
The gas system and the optical alignment system
H. Kobayashi, M. L. Brooks,*l D. S. Brown,*2 N. Bruner,*3 D. E. Fields,*3 A. Hoover,*2 N. Kamihara,*4
D. Kim,*5 D. M. Lee,*l M. Leitch ,* l M. X. Liu,* l S. Pate,*2 N. Saito, T.-A. Shibata,*4
W. Sondheim,* 1 J. Murata, R. Towell,*l and K. Yongil*5
The PHENIX south muon tracker is a subsystem inthe south muon arm which consists of a muon identifier
and a muon tracker. The muon tracker consists of threestations of cathode strip chambers aligned in the radial
field magnet.
Following the mechanical installation of the chambers and electronics support structures, which was finalized in December 2000 , the installation of the frontend electronics and the high-voltage system was carried out. Finally, in May 2001 the south muon magnet
was installed in the interaction region of the PHENIX
experimental hall. Figure 1 shows a picture taken when
the south muon tracker was installed in the interaction
region with full integration of chambers and electronics
for the first time. The RIKEN team has taken responsibility for the design and construction of the chamber
gas supply system and the optical alignment system.
Both systems were installed during the period whenthe electronics were installed.
The muon tracker gas system uses a nonflammablegas mixture, Ar: CO 2 : CF 4 = 50: 30: 20, with recirculation of the return gas. The requirements and structure of the gas system are described in a previous ar-

Fig. 1. Three stations of cathode strip chambers and theirfront-end electronics for the south muon tracker havebeen installed in the south muon magnet (left in the
picture). The north muon tracker (right) will be installed in the summer of 2001.
*1
*2

*3
*4

*5

232

Los Alamos National Laboratory, USA
New Mexico State University, USA
University of New Mex ico, USA
Tokyo Institute of Technology
Yonsei University, Korea

ticle. I ) The electronic read-out system of pressure andflow measurements was constructed using the ADAM
5000 system. This system is used for an alarm system and the values are collected by a Windows-based
server and logged to the database. Oxygen contamination in the supply gas is monitored by an oxygen
analyzer and proved to be less than 300 ppm in the
non-recirculation mode, while it is at a maximum of
5 ppm in the fresh gas. There was a minor problem
in the compressor which was used for the recirculationof the return gas. The compressor was replaced witha new one which has a smaller volume than the original. Since the replacement, t he gas system has beenrunning very stably.
The optical alignment system was designed 1) forthe purpose of real-time monitoring of the relativealignment between the three stations. Each opticalalignment system unit consists of an optical fiber asa light source at station 1, a convex lens at station
2 and a video camera at station 3. A metal halide
high-intensity discharge lamp was chosen for the baselight source to meet the requirements for high-intensity
white light, low infrared intensity and long lifetime ofmore than 6000 hours. There are 56 optical alignment
system units mounted in the south muon tracker. Images from each CCD camera are captured once perhour, processed online and saved in a database. Figure 2 shows a three day history of focal image position
measured by the optical alignment system. We observed a 60 p,m shift when the magnetic field of thespectrometer was switched on. Systematic analysis toclarify the alignment change detected in all 56 cameras
is under way.
Deviation of the initial geometry alignment from thedesign value was expected to be less than a millimeter,
because each chamber is constructed within a 25 p,mtolerance and the survey data after installation shows
less than 1 mm of misalignment between stations. The
correction of the misalignment can be achieved using
straight tracks taken by field-off collision runs or fieldoff cosmic runs. The correction of the misalignment
between the three stations is under way2) using themuon tracker reconstruction software.
We have been recording Au-Au collision data withthe muon tracker since July 2001. Figure 3 shows
the coincidence between the multiplicity of clusters inmuon tracker station 1 and the total charge detected in
the beam-beam counter measured for the Au-Au collisions at .jSN N = 200 GeV. There is a clear positive

jStation 1 multiplicity va. Total BBC charge*;'-"-100 Ji m;c.'::~:~:~. i

t

-

.'

"

"

"

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"

..

"

~ ~ ro"' •• ..

... :. ' f

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'II

lOa.'

-·r ..·..··.. ·l00 Jim-+_._. ~ ...
t-..._.. f •-.~~~~~cq~~~~~~~~~~.u~. -~-~"-' .~1

3 [day]Fig. 2. History of focal image position for azimuthal direction (upper) and radial direction (lower). In the middleof the measured period in the plot, a 60 f.Lm position
shift caused by the spectrometer magnet ON / OFF was
detected.

correlation as expected since the beam-beam counter
covers the rapidity range of 3 < 1'171 < 4 while the muontracker covers 1.1 < 1'171 < 2.4.

Fig. 3. Coincidence between multiplicity of clusters inmuon tracker station 1 and total charge detected in the
beam-beam counter measured in the Au-Au collisions
at ..JSNN = 200 GeV.

References
1) J. Murata et al. : RIKEN Accel. Prog. Rep. 34, 237(2001).
2) N. Kamihara et al.: RIKEN Accel. Prog. Rep. 35, 231(2002) .

233

RIKEN Accel. Prog. Rep. 35 (2002)

Analytical field calculation of helical magnets
with an axially symmetric iron yoke
T. Tominaka,* M. Okamura, and T. Katayama
Helical conductor

The contribution of an axially symmetric iron yoke
to the helical magnets is studied, as a basic studyof the helical dipoles for the Relativistic Heavy Ion
Collider (RHIC), with consideration of the analytical expressions of the magnetic fields due to a single
helical current. 1) In order to obtain rigorous expressions for the contribution of an axially symmetric ironyoke without saturation to the interior field of helical magnets, a three-dimensional potential problem issolved. 2 ,3) Then, the calculation of the interior fieldof the helical dipole magnet is compared with othernumerical calculations.4 )In this paper, SI (MKS) units are used. The magnetic induction B , the magnetic scalar potential ¢mand the vector potential A are defined as follows,

B = -/1 V ¢m = V x A.

(1)

Fig. 1. Schematic view of a single helical coil placed inside
a cylindrical hole in iron.

Similarly, the relation between the magnetic induction B and the magnetic field intensity H is defined asfollows ,y

B = /1o(H + M) = /10(1 + Xm)H = /1o Km H = /1 H ,(2)where /1 is the absolute permeability, Xm is the magnetic susceptibility, and Km is the relative permeability.
In the case that a single helical current carrying conductor is located at a point (r = b, e = 0) in thez = 0 plane placed inside a cylindrical hole in iron of/l-2 = Km/1o, as shown in Figs. 1 and 2, the generalform for the magnetic scalar potential ¢1 of region 1(r < a) is expressed as a sum of the contribution ¢l,coilof a single helical current conductor and the contribution ¢ 1,iron of an axially symmetric iron yoke. Since
the terms of the modified Bessel function of the second
kind , Kn(nkr) , are excluded by the condition that theorigin be a regular point for the contribution of iron,the general solutions at z = 0 for the magnetic scalarpotential ¢1 and ¢2 of both regions can be written in
the following forms with the unknown constants of An,
B o, and B n ,for b < r < a,aFig. 2. Cross section of a single helical coil placed inside acylindrical hole in iron (z = 0).

¢2(r, e, Z = 0)¢l(r, e, z = 0)
I

=

I
I

- - e - -kb ' " I~(nkb)Kn(nkr) sin ne
27r

7r

6

(3)

Hitachi, Ltd.

234

CXl

(4)

n=l

n=l

Similarly, for r > a,I

= --Boe - - """ B nKn(nkr) sin ne.
27r
7r ~

CXl

The constants may be determined by the use of theboundary conditions at the interface, r = a, between
regions 1, (r < a) and 2, (r > a).
As a result , for the general case that a single helicalcurrent carrying conductor is located at a point (r =b,= rp) on the z = 0 plane , the magnetic scalare""'300.0

potential ¢l,iron due to an axially symmetric iron yoke
in region 1 is expressed as follows,

1'200.0¢l,iron(r, B, z )If {= :; n=l

Km -Kn(nka)J-Z•300 .0

Km -

1

I~(nka)Kn(nka)/In(nka)K~(nka),}{x In(nka) kb1n(nkb)In(nkr) sin n(B - i.p - kz)}.

(5)
For the simple case that a single helical current carrying conductor with radius b = 0.2 m, angle of helical line current at the z = 0 plane, i.p = 0, current,
I = 105 A, pitch length , L = 2 m, and k = 27r / L =7r rad/m, is placed inside a cylindrical hole with radiusa = 0.3 m, in iron of relative permeability, Km = 10 3 ,as shown in Fig. 3, the above-mentioned analytical calculation is compared with a numerical calculation by
TOSCA.5)
In TOSCA calculation, the cross-section of the helical conductor is set to be small (~ 1 mm 2 ) so that the
conductor can be treated as a helical thin line current.
In addition, the length of the conductor is finite as
shown in Fig. 3, and the partial thin layer of the yoke
is replaced with the reduced potential region definedby means of TOSCA analysis. The periodic boundary
condition is utilized so that the length of iron can betreated as infinity.
On the other hand, for simplicity, in this analytical calculation, the iron is treated with the approximation of infinite permeability (K = (0) . The comparisons between the analytical and numerical calculations for the distributions of Bx(z), By(z), and Bz(z)of the magnetic field due to only iron along a line ofx = 0.15 m are shown in Fig. 4. The calculated results
based on the analytical expressions up to n = 20 in
Eq. (5) are shown by the solid lines, and the numerically calculated results by TOSCA are shown by dots.
As a result, the good agreement between the analyticaland numerical calculations is obtained. It seems that
this difference of two calculated results comes from thecoarseness of the elements of finite element method in
TOSCA. Therefore , it is expected that the analytical
calculation can be utilized to check the soundness ofthe numerical calculation.
For the fundamental field calculation for the helicalmagnets with an axially symmetric iron yoke, the analytical expression of the magnetic field is obtained asa rigorous solution of the three-dimensoinal potential~300.0Fig. 3. Schematic drawing in the case of a single helical coilplaced inside a cylindrical hole in iron.

E-!
'd
r-i
Q)

0.03
0.02
0.01

'rl
4-l

0

.~

- 0.01~ -0.02s::

tn -0.03

cu
::E

-0.04

~-~2-------~1------~
0-------1~------w
2

z

(m)

Fig. 4. B x(z), By(z), and B z(z) due to iron, along a lineof x = 0.15 m and y = O.

problem for the case that a single helical current carrying conductor is placed inside a cylindrical hole iniron. In addition, this analytical expression is compared with a numerical calculation by TOSCA withgood agreement.
References
1) T. Tominaka et al.: Nucl. Instrum. Methods, Phys. Res.
A 459 , 398 (2001).
2) T. Tominaka et al.: BNL Internal Report C-A/ AP /55(2001).
3) T. Tominaka et al. : Nucl. Instrum. Methods, Phys. Res.
A to be published.
4) T. Tominaka et al.: IEEE Trans. Appl. Supercond., tobe published.
5) OPERA-3d/TOSCA, Vector Field, Ltd., Oxford, UK.

235

RIKEN Accel. Prog . Rep . 35 (2002)

Computing center In Japan for RHIC physics (CC-J)
T. Ichihara, Y. Watanabe , S. Yokkaichi, N. Hayashi, O. Jinnouchi , Y. Goto , S. Sawada,* 1 N. Saito,
H. En'yo, H. Hamagaki , *2 and M. Ishihara
The RIKEN CC-J ,1) which serves as the computing
center in Japan for RHIC physics, started operation inJune 2000 . The CC-J is aimed at being the principalsite of computing for PHENIX 2) simulation, a regional
PHENIX Asian computing center, and a center for the
analysis of RHIC 3 ) spin physics. The size of the CC-J
almost reached 80% of the planned full scale in November 2001 .
The first PHENIX experiment at RHIC for Au + Au
collision was carried out in the summer of 2000. The
raw data of approximately 1 TB was transferred fromthe RHIC Computing Facility (RCF) at BNL to the
CC-J over the Wide Area Network (WAN). The official
Data Summary Tapes (DST) were produced at the CCJ and they were used by all PHENIX Collaborators.
The Quark Mater 2001 conference was held in J anuary
2001 at BNL. Among 33 PHENIX contributed papers,
21 papers were using the DST produced at the CC-J.
The other applications for the CC-J are described indetail elsewhere. 4 - S ) The year-2 experiment at RHIC
PHENIX started in August 2001. The DST production
for the year-2 experiment is now in preparation at the
RCF .
The following table shows the size of the componentsof the CC-J system.

I 2000 I 2001 I 2002
CPU (SPECint95)9)
Tape Storage (TB)
Disk Storage (TB)
Tape I/O (MB / s)

5900
110
9
45

13000
110
21
45

High Energy Accelerator Research Organization (KEK)*2 Center for Nuclear Study, University of Tokyo

236

512 MB Memo ry IC PU
Alia C luster)~' -,-,1
4C-"'b ",,x _ _----,

3.2 TBLVD RAID

21.2 TB RAID

1000BaseSX(9kB MTU)

2F

supe rco mputer

RIKEN LAN
ACSLS

WAN

Fig. 1. Configuration of the CC-J system.

18000
1400
21
300

Figure 1 shows the configuration of the current CCJ system. The main components of the CC-J are (1)a High-Performance Storage System (HPSS), (2) dataservers and (3) CPU farms. Since the CC-J handles
approximately 250 TB of data per year , the HPSS was
adopted as a hierarchical storage system. 10 )F igure 2 shows the photograph of the CPU farms.
In 2001 , the number of CPUs was increased from 160
to 224. Current CPU farms consist of 14 boxes of theAlta cluster. The current CPUs are Pentium III 7001000 MHz. The linux kernel was updated from 2.2.14
to 2.2.19. Evaluation for the Pentium 4 of 2 GHz has
begun. Load Sharing Facility (LSF 4.1 ) is used for thebatch queueing system.
Four sets of 1 TB Fiber Channel (FC) Redundant
Arrays of Independent Disks (RAID ) were added to the
HPSS server as cache disks. The total file transfer rateof 100 MB/s was observed between the HPSS servers
and Linux CPU farms, which is close to the limit of*1

CPU Farms (224 CPU)
32 Pentiu m 111 (700 MH z)+
96 Penti um 11 1 (8 50 MH z)+
96 Pe ntium III ( 1000 MH z)

Fig. 2. Linux CPU farms .

line speed (1 Gbps) of the current Local Area Network(LAN) . An upgrade plan for the LAN is now underconsideration.
Two SUN Enterprise 450 servers and 12 sets of FC
RAID of 1 TB (total 12 TB RAID) were added as dataservers. A Bonnie benchmark test showed that theread and write performance for one FC RAID for the
2 GB file is 45 MB/s. The total transfer rate for thesenew 12 TB RAID is approximately 540 MB/s.
We are currently using half of the StorageTek PowderHorn silo and four units of the SD-3 Redwood tapedrives for the tape library system as a part of HPSS.
The capacity of the SD-3 tape cartridge is 50 GB per
volume and the transfer rate of the Redwood drive is
11 MB/s. The current total capacity of the tape library for the CC-J is 110 TB, while the expected dataamount for the nominal year at the CC-J is 250 TB.
Therefore, we decided to install a new tape silo, which
can store 5000 tape cartridges.
We are also planning to upgrade the tape drives from
Redwood to 9950B in 2002, which is expected to havethe capacity of 200 GB per volume using the same sizeof tape cartridge. As a result, the total tape-storage
capacity is estimated to be 1400 TB (1.4 Peta Byte) in
2002.
The objectivity/DB had been adopted and commonly used for the detector calibration databases for
PHENIX. The daily mirroring scripts for the objectivity /DB were developed to synchronize the DB at CC-J
and RCF. ID )To optimize data access at the HPSS, data carousel
software l l ) was installed at the CC-J, which was originally developed at the Oak Ridge National Laboratory(ORNL) and modified at the BNL for the RHIC experiment.
Regardubg the WAN connectivity between RIKEN
and BNL, the bandwidth of the RIKEN connection to
the internet was increased from 15 Mbps to 50 Mbps

m January 2001. The bandwidth of the APAN I2 )US-Japan link was also upgraded from 120 Mbps to
1.2 Gbps in October 2001. We are considering a possible entire data transfer by the Network in the near
future. The spin experiment at RHIC is scheduled tostart in December 2002 , and we are planning to transfer the entire data from BNL to CCJ for extensive
analyses.
The authors are grateful to Professor Bruce Gibbard
and the staff of the RCF for their earnest cooperationand discussions.
References
1) T. Ichihara et al.: RIKEN Accel. Prog. Rep. 34, 252(2001), see also http://ccjsun.riken.go.jp/ccj/
2) http:/ / www.rhic.bnl.gov /phenix/3) http:/ /www.rhic.bnl.gov /4) T. Hachiya et al.: RIKEN Accel. Prog. Rep. 35, 241(2002) .
5) S. Kametani et al.: RIKEN Accel. Prog. Rep. 35, 242(2002).
6) H. Torii et al.: RIKEN Accel. Prog. Rep. 35, 243(2002).
7) A. Kiyomichi et al.: RIKEN Accel. Prog. Rep. 35 , 244(2002).
8) M. Naruki et al.: RIKEN Accel. Prog. Rep. 35, 245(2002).
9) http: //www.spec.org/
10) S. Yokkaichi et al.: RIKEN Accel. Prog. Rep. 35, 238(2002).
11) O. Jinnouchi et al.: RIKEN Accel. Prog. Rep. 35, 240(2002).
12) http)/www.jp.apan.net/

237

RIKEN Accel. Prog. Rep. 35 (2002)

Operation of Objectivity/DB system at CCJ
S. Yokkaichi, H. En'yo, Y. Goto, H. Hamagaki ,* l O. Jinnouchi , N. Hayashi,
T. Ichihara, S. Sawada,*2 and Y . Watanabe
Obj ectivity /DBl) is a commercial Object-Oriented
Database Management System (ODBMS) and is
widely tested and used in the field of high energy /nuclear physics. It has been studied through the
CERN RD45 project 2) and the ATLAS experiment.
It was used in the Zeus experiment for the tag DB
in offline analysis. In the Babar experiment, it wasused for online data storage and DST (data summary
tapes) storage. However , in some experiments, such as
the STAR experiment, gave up to use Objectivity/DB,
due to difficulty in maintaining the system.
In the PHENIX experiment, we also use Objectivity / DB as a calibration DB and a run DB in online/offline computing. Single Federation DB (FDB)
is being operated on a dedicated Linux machine in the
PHENIX counting house. FDB in Objectivity meansa set of database files managed under a single namespace. Almost all online programs in the counting houseand almost all offline analysis programs on the machines in RCF (RHIC Computing Facility at BNL) access the single FD B.
In RIKEN CCJ,3) we also require the data in Objectivity /DB to run the PHENIX analysis program, particularly for the 'reconstruction' process in the data
analysis flow. In this process, the raw data and simulation data are converted to the DST, which has 'reconstructed' particle track information, shower cluster
information in calorimeters, Cerenkov ring image in
RICH and so on. Then we have to access and read thePHENIX official FDB. Some methods were discussed
and we now operate a 'snap-shot ' copy method 4 ) to
duplicate the official FDB and deploy it in CCJ. Using the copied FDB , official PHENIX DST production
for the data taken in 2000 was performed at CCJ lastDecember and about 40% of the available raw data isprocessed in CCJ. The remainder was processed at
RCF.
For such production, the calibration DB can be usedwith fixed - - 'snap-shot' - - data which is copied
by hand at the appropriate time. However, during
preproduction, calibration works are ongoing and there
are frequent updates of the official DB. In this case,frequent updating of the DB in CCJ is also expected.
The automatic daily copying is now being tested fortwo month. Current size of the PHENIX FDB is about
2.4 GB. The two main causes of failure of automatic
duplicate processes were as follows.
(1) Failure of the DB backup process in RCF using
built-in command 'oobackup. ' This is caused by the
*1

*2

238

Center for Nuclear Study, University of Tokyo
High Energy Accelerator Research Organization (KEK)

remaining DB locking, mainly from some dead or forgotten processes. (2) Network failure between RIKEN
and BNL. Instability of WAN broke or delayed the filetransfer using the 'scp' command. These two facts convinced us that the 'replication' function of Objectivity /DB, which is a real-time data duplication method
via a network which we did not adopt , could cause
many problems in the operation of the official FDB in
our current network environment.
A dedicated Linux host for DB in CCJ has dual
1 GHz Pentium III CPUs, 1 GB memory and a 16 GBSCSI local disk. 1000Base-SX ethernet connects the
DB host machine to the 1000Base-SX/100Base-T ethernet switches. Linux machines as CPU farms on
which the reconstruction jobs run are connected withthe switches using 100Base-T. In fact the DB hostis one of the farm machines but the network interface has been upgraded. SUN E450 as NFS servers
with Fibre Channel RAID disks are also connectedwith the switches using 1000Base-SX. The RAID disks
are served to both the DB host and CPU farm hosts.
These configurations are shown in Fig. 1. In this environment , the network bandwidth was measured using
a benchmark program 'net perf. ' 5 ) Over 100 MB / s wasachieved using multiple sessions from the DB host to
30 CPU farm nodes, while 12 MB/s was achieved fromthe DB host to typical single CPU farm node. The
DISK I/O bandwidth of the DB host was 26 MB/s for

14 Alta Cluster boxes=112node/224cpu(SUNB4S0)

LOGIN

NFS

NFS

SERVERSERVERSERVER

Fig. 1. Current CCJ system configurations.

block read, which was measured using a benchmark
program 'bonnie. '6)
We measured the data reading performance of the
Objectivity /DB using the PHENIX reconstruction
program for 2001 data (Oct. 28 version). This program reads about 300 MB of calibration data and runinformation data from the DB at the initialization
stage. Multiple jobs running on multiple CPU farmnodes read the Objectivity/DB data simultaneously(differences in starting times of jobs are less than 60
seconds). Two read methods are tested. One uses
the Objectivity Advanced Multi Thread Server (AMS).
AMS runs on the DB host, reading the DB data fromthe local disk and transferring it to the client processes.
The other uses ordinary NFS. Client processes readthe data from the NFS disk on which the DB data isplaced. In both cases, the Objectivity Lock Server also
runs on the DB host and processes the read lock of DB.
In the AMS case, about 4MB/s was achieved for asingle job, 40 MB/s for 10 jobs, 35 MB/s for 100 jobs
and 28 MB/s for 200 jobs. The saturation effect wasobserved. CPU usage was 95% for over 40 jobs. Local disk I/O does not seem to limit the performance.
A cache effect may be effective for such multiple access to the same data at the same time. These were
measured using the UNIX command 'netstat -i.' The
number of the AMS thread had no clear effect between
8 (default), 4 and 16 with respect to the data output
flow.

In the NFS case, about 50 MB/s was achieved for
200 jobs, for the DB data placed on the SUN NFS
server. This was measured using SNMP (simple network monitoring protocol) at a port of the ethernet
switch connected with the NFS server. CPU usage of
the NFS server host was about 50% for kernel and 50%
was idle.
It seems that the latter is more efficient than theformer . However, the NFS method with the Linuxdisk will be compared with the AMS method on Linux,
because the SUN NFS server is more expensive andmay not be available in such dedicated way.
We would like to thank our collaborators at
PHENIX. Dr M. Purschke advised us regarding akernel configuration of the DB host machine. Dr T.
Chujo and A. Kiyomichi explained the behavior of
AMS from their experience of production job management at RCF.
References
1) http://www.objectivity.com/
2) http://wwwinfo.cern.ch/asd/rd45/index.html
3) T. Ichihara et al.: RIKEN Accel. Prog. Rep. 35 , 236(2002); RIKEN Accel. Prog. Rep. 34, 252 (2001).
4) S. Yokkaichi et al.: RIKEN Accel. Prog. Rep. 34, 256(2000).
5) http://www .netperf.org/ netperf/N etperfPage.html
6) http:/ /www .textuality.com/bonnie/

239

RIKEN Accel. Prog. Rep. 35 (2002 )Data CarouseljORNL batch system for HPSS at CCJ
O. Jinnouchi , T. Ichihara, Y. Watanabe, S. Yokkaichi, Y. Goto, N. Saito, M . Ishihara, H. Hamagaki,*lS. Sawada,*2 J. Lauret,*3 T. G. Throwe ,*4 and H. En'yo
The huge amount of data (of petaByte order) fromthe PHENIX experiment l ) at the Brookhaven National
Laboratory (BNL) 2) is stored in the HPSS (High Performance Storage System) ,3) which consists of a large
tape library system.
As the PHENIX experiment being the large groupcollaboration, a large number of simultaneous data retrieval requests from different users and at different
submission times are expected. In order to deal withsuch conditions and to achieve the optimum file transferring performance, the Data CarouseljORNL batch
system has been introduced at the RHIC Computing
Facility (RCF).4)
In RIKEN CCJ ,5) the complete data summary tape(DST) and raw data produced by the PHENIX detector are · stored in HPSS in exactly the same manneras in RCF. Therefore, in order to provide a highperformance data retrieval facility to regional users, itis necessary to install the Data CarouseljORNL system at CCJ as well.
This system consists of two parts, namely, the
ORNL batch system and the Data Carousel. The
ORNL batch system was designed such that HPSS
could receive file-list oriented requests rather than requiring a per file restoration basis. This feature wasbelieved to have eliminated the inefficiency which exists due to the fact that HPSS itself physically consists of tapes and not of disks. However, the ORNL
batch system alone could not solve this problem because of the characteristics of the means of requesting
the data. Data requests were carried out in the following, (1) multiple users and different groups are notaware of each other 's activities. (2) The users submit
the file-list at the time when the data is required fortheir analysis. Thus, requests are received intermittently rather than consecutively. To optimize theseoverlapping requests by multiple users , there should
be one layer on the top of the ORNL batch system;
this is the Data Carousel.
Figure 1 shows how the ORNLjData Carousel
works. The Data Carousel consists of a server anda client base system. The user only interacts with theclient side of the carousel using the script /usr/local/
carousel/hpss_user.pl, either from ccjsun or from linux
nodes. A detailed description has been given by theauthor who designed this scripts. 6 ) For a new user at
CCJ, a simple usage guide for this script can be foundon the web.7)
*1

*2
*3
*4

240

Center for Nuclear Study, University of Tokyo
High Energy Accelerator Research Organization (KEK)
Dept. Chern. , State University of New York, USA
Brookhaven National Laboratory, USA

HPSS tllpe Ubnlry

nfa 01" 101:81
disk

Fig. 1. Schematic diagram of the ORNL/Data Crouselfunction.

The file lists from several users are gathered in the
MySQL database 8 ) which resides in ccjsun.
On the server end , the Data Carousel inspects the
MySQL database and generates comprehensive filelists using the script hpss_server.pl. Then the file lists
are submitted to the ORNL batch system. This script
is currently invoked every twelve minutes by a cron job.
HPSS then stages the fi les on cache disks, and issues
data transfer to local disks through the pftp command.
Users are also able to check the current status of requests through MySQL queries .
The latest version of the Data Carousel currently
used in RCF has several new features . One is a groupaccount with which users are categorized according totheir sub-detectors, the physics working group they bolong to, and so on. The other is a faci lity for realtime queries through web browsing. CCJ also plans to
upgrade the carousel scripts in order to realize thesefeatures.
The data carouseljORNL batch system will surely
contribute to the RIKEN Spin Physics project whichis going to produce a huge amount of data from thisyear onwards.
References
1) http) /www.phenix.bnl.gov2) http://www.bnl.gov3) http://www.sdsc.edu/hpss/
4) http://www.rhic.bnl.gov /RCF /5) http://www.ccjsun.riken.go.jp/ccj/
6) http://nucwww.chem.sunysb.edu/pad/offline / carousel/ carousel. html7) http://www.ccjsun.riken.go.jp/ ccj/doc/carousel/ carouseLuguide.html
8) for more information see,
http://www.mysql.com/documentation/index.html

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of electron and photon at RHIC-PHENIX
T. Hachiya*l and Y. Akiba, *2 for the PHENIX Collaboration
One of the unique characteristics of the PHENIX 1)
experiment among all the RHIC experiments is its
ability to identify and to measure electrons and electron pairs at central rapidity region. During thefirst physics run of RHIC in 2000, PHENIX recorded
more than five million Au+Au collisions at VSNN =130 GeV.
Electron measurement is important in studying all
stages of time-space evolution of heavy ion collisions.
There are many interesting processes such as open
charm semi-Ieptonic decays, thermal radiation, and dilepton decay of vector mesons, while background electron sources include Dalitz decays and photon conversions in the detector.
Photon measurement is also important in investigating the characteristics of hot and dense matter created in heavy ion collisions. Photons can be measured
by e+ e- pairs from internal and external conversions.
The conversion method is a powerful tool in the low
Pt region because the method provides a clean measurement of identified photons from the collision vertex
with a better momentum resolution than the calorimeter method.
For the electron measurement ,2) charged particle
tracks are reconstructed by a tracking device (the DC
and the PC) and are confirmed by an associated hit in
EMCal. We use the number of hits and the shape of
the Cerenkov ring measured in the RICH, and the E Ip
ratio in order to select electron tracks. Energy(E) andmomentum(p) are measured by the EMCal and theDC, respectively. Electron detection efficiency is estimated by using a PHENIX detector simulator (PISA)
based on GEANT. The detector's response in the
PISA is well tuned so that real data can be reproduced.
For the photon measurement 3 ) by the conversion
method, similar e+ (e-) selection criterion is applied.
After the selection, the invariant mass of e+ and eis calculated. Then, we select the pairs with mass lessthan 80 MeV as conversion photon. The photon detection efficiency is also estimated by using PISA with 7r 0
as the photon source.
Figures 1 and 2 show the transverse momentum
spectra of inclusive e+, e- and photon with minimum
bias Au+Au collisions. Those spectra are corrected forthe electron and photon detection efficiencies, respectively. The work to determine which particles are thesource of electron and photon is in progress.
We used the PHENIX Computing Center in Japan(RIKEN CC-J)4) for the electron and photon analysis.
The large computing power of the facility was very
*1

*2

IAu+Au ~s NN= 130 GeV min. bias I~~

1 ~-------------------------,u

PHENIX Preliminary

"';..
~10'1

M~

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Z

teo
t e+

·2

~ 10

.......

+·5

10

10.6 L.L.Ll..L..L.L.L.L..L...l..J....L.L.L...L..J...j...I..L..JL...L.L.L.L.Ll..L..L.L.L.L...........- ' - ' - ' - ' - ' - '
1.5
2
2.5
o 0.5
3
as 4
P t (C3eVlc)

Fig. 1. Transverse momentum spectra of inclusive electron(black) and positron (white).

PHENIX PRELIMINARY
Min.Bias Au+Au~=130GeV+++.+-;-

T-t·3

10 ::-

I

0.5

I

I

I

1

1.5

2

I

2.5

3

3.5

Photon PI (GeVlc)

Fig. 2. Transverse momentum spectrum of inclusive photon.

helpful in the simulation and the efficiency study. We
would like to thank the members of the Radiation Laboratory for their support of our project.
References
1) PHENIX Conceptual Design Report, BNL (1993) (unpu blished) .
2) Y. Akiba et al.: PHENIX Analysis Note No. 90 (2001).
3) Y. Akiba for the PHENIX Collaboration: Nucl. Phys.
A 698, 269c (2002).
4) T. Ichihara et al.: RIKEN Accel. Prog. Rep. 34, 252(2000).

Hiroshima University
High Energy Accelerator Research Organization (KEK)241

RIKEN Accel. Prog. Rep. 35 (2002)

Performance of PHENIX RICH for RHIC first year run
S. Kametani ,*1 H. Hamagaki,*1 K. Ozawa,*1 T. Sakaguchi,*1 K. Oyama, *1
T. Matsumoto,*l J. Kikuchi,*2 M. Hibino,*2 and M. Tamai*2
To investigate the properties of hadrons and QCD
physics in hot and dense matter, electrons are useful
because they have no strong interaction with matter.
In PHENIX experiment, 1) electron identification is
performed by a Ring Image CHerenkov (RICH) detector,2) In RICH , electrons are identified by Cherenkov
lights which are generated in the gas volume of RICH
and focused on PMTs with a mirror.
RI CH detector provides e I 7r discrimination below
the 7r Cherenkov threshold, which is set at about
4 GeV I e. In combination with the electromagnetic
calorimeter (EMCAL) in each PHENIX arm and thetime expansion chamber (TEC) in one arm, the goal
is to limit the false identification of hadrons as e+ ande- to less than 1 per 10 4 , for momenta below theCherenkov threshold. The EMCAL is capable of rejecting about 90% of hadrons at momenta> 1 Ge V I e,
and the TEC (present in only one arm of PHENIX)
enables dE I dx separation of electrons from pions for
momenta below about 1 Ge V I e.
The PHENIX RICH detector was successfully operated in the first RHIC run, designated run 1, which
took place in 2000. The results have been used to evaluate the performance of the RICH.
The occupancy of the RICH was low, only about
3.4% even for the most central Au + Au collisions, due
to the very high granularity of the detector. The mean
number of photo electrons per ring is ~ 10.8, which
agrees very well with simulation results and the design
goal. Figure 1 shows a contour plot of RICH hits associated with tracks. The ring can be clearly observed.
Figure 2 illustrates electron identification using the
RICH detector. In this figure , the ratio of the energy(measured by the calorimeter) and the momentum of
the charged tracks in the transverse momentum rangeof 1.1 < PT < 1.2 GeV Ie is plotted.
For all charged tracks, the E Ip ratio has a mip peakat E Ip
0.3 superimposed on a broad distribution
caused by hadronic interactions. When RICH hits are
required , a clear peak appears at E Ip = 1.0, which isthe electron signal. The background due to random
associations of RICH hits and tracks is estimated, andalso is shown in Fig 2.

RICH ring associated with Drift Chamber track.cCCClOOC

•

..

o

0

000 0

0

0

0

0

c

Oo
c

DOD 0

•

•

'00000000000 0.. oDDDDDDDDDDO
ac;:ocDoDDDoDDDDC

acODDDDDDDDDc
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..

oODDDoDCloDD OD O c .
..

0

0

0000

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0

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. COD

0

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0

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cODoDDDDODODa..

-O O DDDDClDDDcc-1 ---: •'00000000000'
0 0 0 0 DO 0
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[] C

-21-3 ~~
1~~1~~1~~1~~1~~1~~~1~

-20

-15

-10

-5

0

5

10

15

20

Z[cm]

Fig. 1. Contour plot of RICH hits relative to the projectedring centroid from tracking, summed over many tracks.

IElp ratio: 1.1GeV/c < p< 1.2GeV/c I

0.2 0.4 0.6 0.8

1 1.2 1.4 1.6 1.8
E/p2

Fig. 2. Ratio of energy and momentum for all Drift Chamber (DC) tracks.

i".J

*1

*2

242

Center for Nuclear Study, Graduate School of Science, University of Tokyo
Advanced Research Institute for Science and Engineering ,Waseda University

References
1) Y. Akiba et al.: Nucl. lnstrum. Methods Phys. Res. A
453 , 279 (2000).
2) T. Sakaguchi et al.: Nucl. lnstrum . Methods Phys. Res.
A 453 , 382 (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Performance of the PHENIX EMCalorimeter
H. Torii,* A. Bazilevsky, H. En'yo, Y. Goto, K . Imai,* and N. Saito, for the PHENIX Collaboration
In the early summer of 2000, the PHENIX experiment for heavy-ion physics at RHIC began, andthat for spin physics was started in 2001. In thisexperiment, the electromagnetic calorimeter (EMCal)
plays an important role in detecting photons and electrons/positrons. In order to cover topics in both areas of physics, e.g., thermal photon measurements inheavy-ion physics, and prompt photon, nO and weakboson measurements in spin physics, the EMCal mustcover a wide energy range from a few hundred Me V to
80 GeV. Spin physics also requires the energy measurement to be within 2% accuracy for measuring cross sections of prompt photons and nO production with 10%
errors, because the cross sections have steep transverse
momentum (PT) slopes. The PHENIX EMCal consistsof a lead scintillator (PbSc) and lead glass (PbGI). In
this paper, we will report only the performance of the
PbSc and the achievement of 2% accuracy.
The PbSc is a Shashlik-type sampling calorimeter
made of alternating tiles of lead and scintillator. The
basic block is a module consisting of four towers which
are optically isolated and are read out individually. 1)
The module has a 5.52 x 5.52 cm 2 cross section and37.5 cm length. From several beam tests at BNL 2 )and CERN, 3,4) the PbSc was found to have a nominal energy resolution of (YE/E = 2.1% EEl 8.1%/.JE
from 0.5 GeV /c to 80 GeV /c, where EEl represents thequadratic sum.
Figure 1 depicts the comparison of energy deposits
by 1.0 GeV /c n+ at the BNL beam test and 0.91.1 GeV /c n+ at PHENIX Au+Au collision VSNN =130 GeV with a 0.27 GeV minimum ionization peak.

o 0.1 0.2 0.3 0.4 O.S 0.6 0.7 0.8 0.9

1

GeV

Fig. 1. Comparison of 1.0 GeV Ic 7r+ energy spectrum (dotted line) at AGS beam test and 0.9-1.1 GeV Ic 7r+
energy spectrum (line) at PHENIX Au+Au collisionJs = 130A GeV.
Kyoto University

..

..

;:

;:

0.2

0.4

0.6

0.8

1

1.2

1.4
E/p

0.1

0.2

0.3

0.4

0.5 ·

",•• o(GeV)

Fig. 2. (Left) Ratio of measured energy and momentum forelectron sample at PHENIX Au+Au Collision JSNN =130 GeV. (Right) Two-photon invariant mass spectrumat PHENIX Au+Au Collision JSNN = 130 GeV.

The n+ is identified by the momentum measured by
the tracking system and the time of flight measured
by the EMCal itself. The relative energy scale 5 ) for
all towers during Au+Au collision is already calibrated using the minimum ionization energy of a cosmic muon traversing laterally and that of a charged n
traversing lengthwise. The minimum ionization peakof 1.1 GeV /c (0.9 GeV /c) n+ is predicted to be higher(lower) than that of 1.0 GeV /c n+ by 2%. The above
comparisons are consistent within 2% accuracy.
Figure 2 shows the E / P spectrum for the electron
sample, which has a peak at 1.02, and the two-photon
invariant-mass spectrum with a nO peak. The electron
sample required a hit in Ring Image Cerenkov counter(RICH). The background in the E/p spectrum is already subtracted. Because of the 2% error in the momentum measurement of the tracking system, the E /p
spectrum indicates that the energy measurement has
a 1.02 ± 0.02 accuracy. The nO mass is evaluated after
background subtraction by the event mixing method
and is consistent with a nominal 7r 0 mass within a 2%
statistical error.
From these three indipendent measurements,
1.0 Ge V / c n+ minimum ionization peak, E / p spectrum, and nO mass, we can conclude that the absoluteenergy scale has 2% accuracy and our physics requirement is satisfied.
References
1) G. David et al.: IEEE Trans. Nucl. Sci. 42 , 306 (1995).
2) E. Kistenev et al.: Proc. 5th Int. Conf. Calorimetryin High Energy Physics, New York, USA, 1994-9 . . . . 10
(World Scientific, 1994), p. 211.
3) Y. Goto et al.: RIKEN Accel. Prog. Rep. 32, 47 (1999).
4) H. Torii et al.: RIKEN Accel. Prog. Rep. 33,168 (2000).
5) H. Torii et al.: RIKEN Accel. Prog. Rep. 34, 238 (2001).

243

RIKEN Accel. Prog. Rep. 35 (2002)

Hadron measurement at RHICjPHENIX
A. Kiyomichi,*l T. Chujo,*2 A. Danmura,*l S. Esumi,*l S. Kato,*l Y. Kuroki,*l H. Masui,*l Y. Miake,*lH. Ohnishi,*2 M. Ono,*l S. Sakai,* l S. Sato,*2,*3 M. Suzuki-Nara,*l and H. Tsuruoka*lHeavy ion collisions at relativistic energy offer the
possibility of producing highly compressed strongly interacting matter, which may form the quark gluon
plasma (QGP). The production of hadrons is one of theimportant probes of the QGP, since hadrons containbasic information about collision dynamics. Hadron
momentum spectra and rapidity densities are affectedby thermal freeze-out and collective flow. The particle ratios are sensitive to the chemical propertiesof the system and particle production mechanism.
These measurements will be a first step in investigating
whether the QGP is formed or not.
The highest energy heavy ion collisions at J S N N =130 Ge V began in the summer of 2000 at the relativistic heavy-ion collider (RHIC) at B L. PHENIX is oneof the major experiments at RHIC to measure a variety
of signals from the heavy-ion collisions. Particle identification for charged hadrons is performed by timeof-flight measurement using the beam-beam counters(BBC) and the time-of-flight counters (TOF), while
the drift chamber (DC) and pad chamber 1 (PC1) provide the momentum measurement. The designed timeof-flight resolution is about 100 ps. This allows us toachieve a PID capability for high-momentum particles,a 4(J 1f IK separation at momenta up to 2.4 Ge V Ie anda K/proton separation up to 4.0 GeV Ie.
Figure 1 shows a contour plot of the time-of-flight
versus the inverse momentum multiplied with the signof the charge. The time-of-flight is measured as the
TOF minus collision time zero given by BBC in minimum bias Au+Au collisions at the energy of JSNN =130 GeV. A clear separation between particles is seenin the figure. This clearly demonstrates the particle
identification capability using the TOF in the year
2000 run period.
The detector calibration of both BBC and TOF set
performed at CC-J. The calibration of TOF was performed after track reconstruction and momentum calculation. By selecting high momentum pion, the timing offsets for each of the counters are adjusted . The
time-of-flight resolution of 96 ps is achieved at central
Au + Au collisions (Fig. 2).
In the summer of 2001, RHIC achieved the full energy collision, and the second year data are collecteduntil the end of 2001 with Au+Au ions at JSNN =

*1

*2

*3

244

University of Tsukuba
Brookhaven National Laboratory, USA
Japan Society for the Promotion of Science

PHENIX Hi h Resolution TOF
Au+Au~ SNN = 130 A GeV~- 8.-~--~~----~--~~~~~~--

-

~

"

::::;

E
:::l

C

~ 2
o

::l:
;:: 0
-2

-4
-6
~~~~~~~~~LULU~~~ULULULU

10

15

20

25

30

35

40

45

50

55

60

Time of Flight [ns]Fig. 1. Contour plot ofthe time-of-flight versus inverse momentum.

TOF • TOFexpected I
70

1.'< p <1.8GeV/c

1t

60
50

(j -

K

-1

96ps
p

3

4

TOF - Uclbeta [nl]Fig. 2. The time-of-flight distribution in the momentumis 1.4 < p < 1.8 Ge V / c for positively charged pions.
The overall time-of-flight resolution of less than 100 ps
is achieved.

200 GeV. The detector calibration for the second year
run will be performed at CC-J.
We would like to thank the members of the Radiation Laboratory for their support of our project,
especially Dr. T. Ichihara, Dr. Y. Watanabe, Dr. S.
Yokkaichi, and other CC-J staffs.

RIKEN Accel. Prog. Rep . 35 (2002)

Analysis of experiment KEK PS-E325, for the measurement ofw / ¢ meson decays in nuclear matter
M. Naruki,*1 J. Chiba,*2 H. En'yo, H. Funahashi,*1 H. Hamagaki, M. Ieiri,*2 M. Ishino,*3 H. Kanda,*4
M. Kitaguchi, S. Mihara,*3 T. Miyashita,*5 T. Murakami, R. Muto ,*1 M. Nomachi,*6 K. Ozawa,*7 F. Sakuma,
O. Sasaki,*2 H. D. Sato, M. Sekimoto, T . Tabaru, K . H. Tanaka,*2 S. Yadama,*1
S. Yokkaichi, and Y. Yoshimura*8

It is generally believed that 99% of hadron massis generated due to the spontaneous breaking of thesymmetry in the strong force. However, only few experimental evidences exist to support this idea. Since
the modification of hadron mass and decay width in a
nuclear medium is theoretically predicted as a consequence of the restoration of the broken symmetry, experimental observation of such phenomena has become
one of the most interesting topics in hadron physics today.
We are currently performing an experiment at theKEK proton synchrotron to observe the decay of ¢ meson from nuclear targets, to inspect the modificationof hadron properties at normal nuclear density. The
experiment is to measure the invariant mass spectraof ¢ --7 e+e - and ¢ --7 K+ K- decay modes simultaneously. We also measure branching ratios in the two
decay modes, which are sensitive to the mass shift of¢ mesons and kaons.
In the analysis of the 1998- 1999 data, we have ob-[events /50MeV/c 2 )100served the significant enhancement below the w mass
peak of e+ e- pairs for the copper target, which is attributed to the mass modification effect in nuclear matter (Fig. 1).1) The ¢ meson peak is also visible in t hee+ e- spectra, but further analysis is indispensable toconfirm the modification of ¢ .
In year 2000, we newly installed a forward lead glass
calorimeter and a vertex chamber to improve the tracking and the particle identification performance for t hefurther study of such modification of meson property.
To expedite the analysis, we have recently started
to use CC-J at RIKEN. Thanks to the excellent cpu
power of CC-J , our most time-consuming step, thetrack reconstruction, can be achieved 10 times faster
simply by using the surplus time of CC-J . The statistics of our results will thus be improved very soon.
References
1) K. Ozawa et al. : Phys. Rev. Lett. 86, 22 (2001) .

[events /50MeV/c 2 )
30

a)

b)

25

80
--

60

fit result.......... w,p,cp -+e"'e- - - w-+1t°e-+e_. - . - combinatorial

20

--

15

.......... w,p,cp -+ e"'e- - - W-+1t°e-+e-

fitresult- . _ . - combinatorial

40
10

20

5

°0~~~~~~~~~~1~.6~1.8~2

ete- invariant mass

[GeV/c 2)

ete- invariant mass

Fig.!. Invariant mass spectrum of 1998 e+ e- data.

*1 Kyoto University*2 Institute for Particle and Nuclear Studies, High Energy Ac*3
*4
*5

*6

*7

*8

celerator Research Organization (KEK)International Center for Elementary Particle Physics, University of Tokyo
Tohoku University
Fujitsu Corporation
Research Center for Nuclear Physics, Osaka University
Center for Nuclear Study, University of Tokyo
Xaxon Corporation

245

8. Miscellaneous

RIKEN Accel. Prog . Rep . 35 (2002)

Development of new analytical system using the electron
cyclotron resonance ion source and heavy ion linear accelerator
M. Kidera, T. Nakagawa, S. Enomoto, K. Takahashi, H. Baba,* l R. Hirunuma, T. Ohyama,*2 K. Igarashi,*3
M. Fujimaki, E. Ikezawa, O. Kamigaito, M. Kase, A. Goto, and Y. Yano
As an extension of accelerator mass spectrometry(AMS) for detecting trace elements in various materials and for overcoming the disadvantages of the present
AMS, we propose a novel method using the ECRIS
and heavy ion linear accelerator l ) (ECRIS-AMS) . The
production of positive ions in ECR plasma does nothave problems such as the difficulty in production ofnegative ions , which is because of the electron affinity, because the electrons in ECR plasma have a highkinetic energy and easily ionize any atom. Furthermore, when using this system, the acceleration as wellas transport depends only on the mass-to-charge ratio(A/q) of heavy ions. This indicates that many traceelements can be analyzed simultaneously. Thus, thismethod allows us to analyze about 80% of the elements
when choosing only ions of A/q = 3,4, and 5. It is possible to carry out a very low background experiment,
because the effect of molecules will be minimized using t he accelerator. Part of the results and method aredescribed in Refs. 2 and 3.
To ionize the t race elements in a sample, we inserted
it directly into the plasma of the ion source. For example, a solid rod is inserted into the plasma and thenheated to obtain sufficient vapor pressure. For production of intense beams of highly charged ions with
A/q = 3, 4, and 5, we need a high-performance ion
source. For this purpose, we used the RIKEN 18 GHzECRIS which is highly suitable for producing intense
beams of highly charged heavy ions. The performanceof this ECRIS is described in Ref. 4.
To demonstrate the sensitivity of the method, we analyzed a Ah03 rod which is difficult to analyze in conventional AMS. The A1 20 3 rod was inserted into theplasma and heated to obtain sufficient vapor pressure.
The particles with A/q = 5 as analyzed using the first
analyzer magnet were accelerated to 2.0 MeV / u withRILAC and the RFQ linear accelerator. For beam tuning, the parameters of each of the magnets were fixed
to A/ q = 5 for beam transport after the acceleration.
The elements with same A/q = 5 were selected using
two dipole magnets for analysis. We detected elementswith mass numbers which were multiples of 5.
Figure 1 shows the absolute concentrat ions of traceelements in the Ah03 rod (purity of 99.5%). Openand closed circles are the results obtained by using inductive coupled plasma-atomic emission spectrometry(ICP-AES) and ECRIS-AMS . For obtaining the ab*1
*2

*3

Rikkyo University
Shizuoka University
Showa Women 's University

lxl0"
lxl0"
l xl 0 · 4~ lxl0 "a. • •o•~ lxl0"~ lx l 0 "• •~ lxl0 "~ lx10 · g...:: lx l0 · '·•1xl0'"
lxl0 ' "•1xl0 ' " L --''--'-............- - ' - - ' - -.L...L.._ _- - - - ' - - _ - - - ' - _Zr
MgSi CI Ca Sc Cr Ni Cu
Cd

Elements

Fig. 1. Relative abundances of trace elements for Ab03
rod of 99.5% purity are compared in results of ECRlSAMS with lCP-AES.

lxl0 "
lx l 0"OJ) l xl0"

~ l xl0 ".a" lxl0 · 7

aO

•

•

,.

ECRIS· 1W6

o ICP.AES~~ lx l0 ".a~ lxl0 "JO...:: l xl0" ·lxlO ' "lxl0 - 12

••

•

ZrMo

Sn

lxl0 · 13

Mg Si CI

Cu

Elements

Fig. 2. Relative abundances of trace elements for Ab03
rod of 99 .99% purityare compared in results of ECRlSAMS with l CP-AES.

solute value of the concentration in the case of using
ECRIS-AMS, the relative concentration of trace elements was normalized using the value of Mg, which
was obtained by ICP-AES. In Fig. 1, it is clearly seent hat 10 trace elements could be detected and ident ified
by ECRIS-AMS with a short term experiment (about
20 minutes). In particular, the detection limit of theelement in the mass region of ",100 was 10- 12 in thisexperiment. The consumption rate of the sample wasless than 1 mg/ h. Figure 2 shows the same tendency
as Fig. 1 for the Ah03 rod (purity of 99.99%)
References
1) M. Odera et a l.: Nucl. lnstrum. Methods Phys. Res.
227, 187 (1984).
2) T. Nakagawa and M. Kidera: J. Mass Spectrom . Soc.
Jpn. 48 , 169 (2000).
3) M. Kidera et a l.: Nucl. lnstrum. Methods Phys. Res. B
172 , 316 (2000).
4) T. Nakagawa et al.: Nucl. lnstrum. Methods Phys. Res .
A 396, 9 (1997) .

247

IV. NUCLEAR DATARIKEN Accel. Prog. Rep. 35 (2002)

New method for calculating aggregate fission-product decay heatwith full use of macroscopic-measurement data
K. Oyamatsu,*! H. Takeuchi,*2 M. Sagisaka,*3 and J. Katakura*4
We propose a new "hybrid" method for calculating
the aggregate decay heat from fission product nuclides
after a fission burst.!) The decay heat should be evaluated not only in the operation of nuclear reactors but
also in the reprocessing, transportation and disposalof radioactive materials produced in the reactors. It
should be noted that the evaluations should not belimited to fissile nuclides in the initial inventory sinceother fissile nuclides are produced through transmutation processes in nuclear reactors.
In the present method, the decay heat from a given
fissioning system is expressed as a linear combinationof macroscopic-measurement data for other fissioning
systems with a small residual term. This method isbased on t he linearity of the decay heat to the fission yield. The coefficients in the linear combination
are obtained from fitting the fission yield of the given
fissioning system with a linear combination of fission
yields of other fissioning systems.
To demonstrate usefulness of this method, it is applied to examining the consistency among measured
decay heat powers of five fast and three thermal neutron induced fissions. The hybrid-method calculations
agree well with the measurements and conventional
summation calculations at cooling times of less than
4000 s, except for a '"'I component measurement of the
235U thermal fission at about 2000 s (see Fig. 1).
These results indicate the consistency and reliabilityof the decay heat evaluation for these systems, with theabove exception. Furthermore, they also imply usefulness of the present method in predicting the decay heatof other fissioning systems, for which no measurements
have been performed so far.
Lastly, it is remarked that the present method could

*1

0.7
0.6

~

~ 0.5

~
X

0 .4
0.3

-

hybrid method...... (hybrid method)-PRo ORNL measurement- - - summation calculationt (5)Fig. 1. Decay heat power from a pulse thermal fission of
235U. The solid (dotted) line shows the decay heat
power calculated using the hybrid method with (without) a correction term. Also shown for comparison are
the results of ORNL measurements (open circles witherror bars) and summation calculations with ENDF IBVI (dash-dotted line).

also be used to identify incorrect decay data values ofindividual fission product nuclides, which deteriorate
the decay heat evaluation. For these values, precise
experimental determination can be realized easily in
the RI Beam Factory due to its capability of supplying
a high-purity intense RI beam.
References
1) K. Oyamatsu et al.:J. Nucl. Sci. Technol. 38, 477(2001).

Aichi Shukutoku University*2 Nihon Unisys, Ltd.
*3 Nuclear Fuel Industries, Ltd.
*4 Japan Atomic Energy Research Institute249

V. DEVELOPMENT OF ACCELERATOR FACILITIESRIKEN Accel. Prog. Rep. 35 (2002)

Effect of plasma electrode position on the beam intensity ofheavy ions from RIKEN 18 GHz ECRIS
Y. Higurashi,*1 T. Nakagawa, M. Kidera, T. Aihara,*2 M. Kase, and Y. Yano
To investigate the effect of plasma electrode position
on beam intensity, we measured the beam intensity of
Ar ions with various charge states as a function of theelectrode position. In this experiment, we observedthat the beam intensity of highly charged Ar ions isstrongly dependent on the electrode position and that
there is an optimum position for maximizing the beam
intensity. The optimum position varies with the charge
state of the ions. A beam intensity of 1.3 mA for Ar 8 +was obtained at the optimum plasma electrode postion. In the last decade, we have applied various kindsof techniques to improve the performance of ECR ion
sources. I ) Through a series of improvements, we haveobtained the essential points for effective beam production from ECRISs in hand. That is, we need to increase the magnetic field and the microwave frequency
of ECRIS, and to optimize the boundary conditions of
ECR plasma, i.e., for the Al cylinder method,2) andthe negatively biased electrode method 3 ) and so forth.
Obviously, the cylinder and electrode form part of theboundary of ECR plasma, and consequently they affect its condition. Therefore, it is not far from realitythat the beam intensity would be enhanced if we could
find the most suitable condition of ECR plasma. From
this point of view, we performed experiments involving
changing the position of the plasma electrode for eachcharge state to find the correlation between the electrode position and the beam intensity. In this paper,
we report the experimental results of Ar ions produced
from RIKEN 18 GHz ECRIS when we change the electrode position, and discuss the role of the electrode.
Figure 1 shows the cross-sectional view of RIKEN
18 GHz ECRIS and its plasma chamber. An Al cylinder covered the inner wall of the plasma chamber. The
thickness of the Al cylinder was 1 mm. We also used
the negatively biased electrode method to increase thebeam intensity. Further details of the design and performance of the RIKEN 18 GHz ECRIS are describedin Ref. 3.
We have chosen three positions of the plasma electrode (positions A, B and C) to investigate the effectof its position on the beam intensity. Other parameters (gas pressure, magnetic field, microwave power
and negative voltage of the biased electrode) were set
so as to maximize the beam intensity at each position.
Figure 2 shows the beam intensities of Ar 8 + as a function of extraction voltage. The open and closed circles
are the results obtained at electrode positions A and B,
respectively. It is clearly evident that the beam inten*1*2

Rikkyo University
SHI Accelerator Service, Ltd.

Plasma Electrode1

Hexapole
magnet

14
1
1
1
1

:4

Position C
141mm

1

~I

Fig. 1. Cross-sectional view of RIKEN 18 GHz ECRIS and
its plasma chamber.

Electrode position B

1.411.21-/'OSilionA

Ci".§. 1.0 c-//~.~ 0.8cCD

E
E
0.6cI'llCD

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Ar

0.2--

I
11

I

I

I

12

13

14

I
15

Extraction Voltage (kV)Fig. 2. Beam intensity of Ar 8 + as a function of extraction
voltage at electrode positions A and B.

251

sity increases with increasing extraction voltage. At
electrode position A, the best result of 1 rnA was obtained at an extraction voltage of 15 kV. On the other
hand, at electrode position B, we obtained 1.3 rnA at
an extraction voltage of 13.5 kV. At position B, we
could obtain a higher beam current at a lower extraction voltage compared to that at position A. At thesame extraction voltage, the beam intensity of Ar 8 +at position B is almost 50% higher than that that at
position A.
Figure 3 shows the beam intensity of Ar ions as afunction of the plasma electrode position. It is clearly
evident that the beam intensity is strongly dependent
on the position. The maximum beam intensity of Ar 8 +is obtained at position C. In the case of 9+, however,the beam intensity gradually increases and becomesalmost maximum at position B, and then decreases
with movement of the electrode toward the ECR zone,
which is the same tendency as described in Refs. 4 and5. From these experimental results, it seems that the
optimum electrode position for maximizing the beam
intensity of multicharged Ar ions exists , and that thisposition varies with the charge state. The plasma electrode placed near the ECR zone is suitable for producing lower charge state Ar ions (8+, 7+). At the edgeof the hexapole magnet, the beam intensity of higher
charge state Ar ions (11+) is strongly enhanced.

252

Position A!

Position B!

Position C

!

1.25

~
E 1.00~'u; 0.75
t::S.: 0.50Ens~ 0.25['r-----....::...:.:.-:..._-......_~~

0.00 01015
5Position of Plasma Electrode [mmJ

Fig. 3. Beam intensity of various charge states of Ar ionsas a function of plasma electrode position.

References
1) R. Geller: Electron Cyclotron Resonance Ion Sources
and ECR Plasma (lOP, Bristol, 1996) and references
therein.
2) T. Nakagawa et al.: Jpn. J. Appl. Phys. 35 , 4077 (1996).
3) For example, S. Biri et al.: Nucl. lnstrum. Methods
Phys. Res. B 152 , 386 (1999).
4) P. Yuan et al.: Proc. 15th Int. Conf. on Cyclotrons andTheir Applications (lOP, Bristol, 1999), p. 402.
5) Private communication with D. Ritz.

RIKEN Accel. Prog. Rep. 35 (2002)

Effect of plasma chamber surface on production of highly charged
ions from ECRIS
Y. Higurashi,*l M. Kidera, T. Nakagawa, T. Aihara,*2 M. Kase, and Y. Yano
To increase the beam intensity of highly charged
heavy ions from ECRIS, it is important not only toincrease the magnetic field and microwave frequency,
but also to optimize the boundary condition of ECR
plasma. Since we observed the strong enhancement ofhighly charged heavy ion beam intensity after coating
Al 2 0 3 on the surface of the plasma chamber, 1) manylaboratories have used it to increase the beam intensities of highly charged heavy ions. Recently it wasreported that the emissive dielectric layer on the surface of the plasma chamber helps to increase the beam
intensity of highly charged Ar ions. 2) All of these experiments suggest that the surface of plasma chamberis quite important to optimize the ECRIS performance.
To investigate the effect of the Ab 0 3 surface directly, we plated with the Al 20 3 on the surface ofAl cylinder (A1203 plating method) and compared thebeam intensity when using the Ab03 plating method
and Al cylinder. As the surface of cylinder becomecompletely Ab03 when using Al 2 0 3 plating method,
we can check its effect clearly.
For investigating the effect of A1 20 3, we used two
different cylinders; 1 mm-thick Al cylinder, and an Al
cylinder of 1 mm thickness plated with Al 2 0 3 of about
20 p,m thickness. New plating cylinder was fabricatedby DIPSOL CHEMICALS Co., Ltd. These cylinders
were inserted into the plasma chamber and covered theinner wall of the plasma chamber of RIKEN 18 GHzECRIS.
Figure 1 shows the beam intensity of Ar l1 + as afunction of RF power at the extraction voltage of
13 kV when using the Al cylinder (open circles) andthe Ab03-plated cylinder (closed circles). The beam
intensity increased with increasing RF power up to
700 W. The beam intensity of Ar l1 + for Ab03-plated
cylinder was always higher than that by using the Al
cylinder. It should be stressed that the beam intensity
was not saturated and we may obtain higher intensity
at higher RF power.
Figure 2 shows the beam intensity of Ar ions as afunction of extraction voltage. For both cases (Ab03plated cylinder and Al cylinder), the beam intensity increased with increasing extraction voltage. The beam
intensity for the Ab03-plated cylinder was always
higher than that for the Al cylinder. The beam intensity when using Al 2 0 3 plating method was almost
50% higher. The best result of 290 ep,A was obtainedat an extraction voltage of 13 kV in this test experiment.
To investigate the effect above in the case of Al 2 0 3
plating method for RIKEN 18 GHz ECRIS , we carefully measured the beam intensity of Ar l1 + with andwithout using gas mixing method. At the extraction
voltage of 12 kV, we obtained 200 ep,A of Ar l1 + without using the gas mixing method. At the same extraction voltage, the best result of 250 ep,A was obtainedusing gas mixing method (we used O 2 gas as a mixing gas). When using the Ab03 plating method, gas
mixing is still effective to increase the beam intensity
in the case of RIKEN 18 GHz ECRIS.

300

<'
:::l

~ 250

.~
c::

300

]

-0- Al Cylinder,-.. 250-<:::l

~ 150

~ 200

.~
I:::

£

200

E

.....- Alp) Plating

100 '--~-'--~-'--~....I..-~....L-~---'-~--'-~---'
15
16
11
12
13
14
9
10

150

.:

Extraction Voltage (kV)

100
E
«l

~

50
0
100

200

300

400

500

600

700

RF Power (W)Fig. 1. Beam intensity of Arll+ as a function of RF power.
Open and closed circles are the results by using Ai cylinder method and Ab03 plating method, respectively.
*1*2-0- AI Cylinder.....- AI 2 0 3 Plating

Rikkyo University
SHI Accelerator Service, Ltd.

Fig. 2. Beam intensity of Arll+ as a function of extraction voltage. Open and closed circles are the results byusing Ai cylinder method and Ab03 plating method,respectively.

References
1) T. Nakagawa et al.: Jpn. J. Appl. Phys. 30, L930
(1991) .
2) L. E. Stiebing et al.: R ev. Sci. lnstrum. 71, 918 (2000).

253

RIKEN Accel. Prog. Rep . 35 (2002)

Liquid-He-free SC-ECRIS at RIKEN
T. Nakagawa, M. Kidera, Y . Higurashi,*l T. Kageyama, T. Aihara,*2 M . Kase, and Y. Yano
Since 1998, we have constructed a new superconducting ECR ion source (SC-ECRIS) as an external
ion source for the AVF cyclotron. The main purpose is
to increase the beam intensity of highly charged heavy
ions (e.g ., Arll+ and Kr 20 + ions) extracted from the
AVF cyclotron.
The main feature of the ECRIS is to use the small
refrigerator for cooling the solenoid coils to 4.2 K.
Figure 1 shows the cross-sectional view of this ECR
ion source. The solenoid coils are cooled by a small
Gifford-McMahon refrigerator. The refrigerator maintains the superconductivity of the solenoid coils without using liquid He. The hexapole magnet consistsof 24 segments of permanent magnet. The maximum
strength of the mirror magnetic field are 2 and 3 T at
the beam extraction and microwave injection side, respectively. The minimum magnetic field strength ofmirror magnetic field (Bmin) is approximately 0.3 T .
The maximum magnetic field strength at the inner surface of the plasma chamber is 1.2 T. The injected microwave frequency is 18 GHz. The maximum power ofmicrowave is 1. 5 k W. The plasma chamber length anddiameter are 35 and 7.2 cm, respectively. Details of thestructure of this ECIS are described in Ref. 1.
This past summer, we successfully produced the firstbeam from this ECRIS . Figure 2 shows t he beam intensities for various charge states of Kr ions. The typical magnetic field configuration is shown in Fig. 3. The~

Kr ion~>;t: 100
III

c:

~

.E
E

m 10

m

20

22

24

26

28

30

Charge State (q)F ig. 2. Beam intensities of highly charged Kr ions. Closed
and open circles are the beam intensities produced from
SC-ECRIS and RIKEN 18 GHz ECRIS , respectively.

EJ:C, 2.0-c~

en 1.5'CCii

u: 1.0.~a;§, 0.5as~oFig. 3. Typical magnetic configuration for producing the
Kr ions.

G-M refrigerators

First stage

j~~~::~~~~~3IGas
Solenoid colis IV III
side

Inlet

Microwave Injection'---_ _ _ _ _ _--'slde

1mFig. 1. Cross-sectional view of liquid-He-free SC-ECRIS at
RIKEN.
*1*2

254

Rikkyo University
SRI Accelerator Service, Ltd.

typical power of the microwave was about 600 W. The
gas pressure of the plasma chamber was 4 x 10- 7 Torr.
The extraction voltage was 12 kV .
To evaluate the performance of this ECRIS, we compared our results with the beam intensities of Kr ionsproduced from RIKEN 18 GHz ECRIS (open circles
in Fig. 2). It is clearly evident that the beam intensity of highly charged Kr ions produced from liquidHe-free SC-ECRIS is much higher than that of ionsproduced from RIKEN 18 GHz ECRIS . For producing these ions, the typical magnetic field strength of
RIKEN 18 GHz ECRIS is about 1.4 T. The plasmachamber length is about 25 cm . As described in Ref. 2,
the ion confinement time is T eof = Bmax/ Bmin(L/Vi) ,where Bmin and Bmax are the minimum a nd maximum magnetic field strengths of t he mirror magnetic
field. L and Vi are the length of plasma and velocity ofions in plasma, respectively. This equation shows thatthe longer plasma chamber and stronger magnetic field

~100 ~

Kr ion

::1.

III

~ 80

~

'0
c:
~
III 60

-

.E
E 40

~

co

III

m 20

/\

~o+

~

1

I

I

I

0.3

0.4

0.5

0.6

sons why the liquid-He-free SC-ECRIS can produce thehigher intensity of highly charged Kr ions compared tothat produced from RIKEN 18 GHz ECRIS .
To test the effect of Bmin on the beam intensityof highly charged Kr ions, we only changed the B min
without changing B inj and B ext . Figure 4 shows thebeam intensities of Kr ions as a function of B min . The
beam intensities gradually increase up to 0.5 T andthen gradually decrease. We found that t he optimized
magnetic field of Bmin is not dependent on charge stateof Kr ions under this experimental condition.

Bmin(T)

References
Fig. 4. Beam intensities of Kr ions as a function of B min .

1) T . Kurita et al. : Rev. Sci . lnstrum. 11 , 909 (2000).
2) R. Geller: Electron Cyclotron Resonance Ion Source and

ECR Plasma (lPO, Bristol, 1996).

cause better ion confinement. This is one of the rea-

255

RIKEN Accel. Prog. Rep. 35 (2002)

Development of ECR ion sources for high-intensity
heavy ion beams
Y . Ohshiro,* s. Watanabe,* T. Kageyama, T. Nakagawa, M. Kidera, M. Kase,
S. Kubono, and T. Katayama
A CRIB separator l ) was installed in the RIKEN accelerator facility and used for nuclear experiments in
2000- 2001. Ion beams produced by the K70 AVF cyclotron with the RIKEN 10 GHz ECR ion source weredelivered to the CRIB separator. Because the users of
this separator have requested intense beams of highly
charged heavy ions, we have made two developments:a method of feeding solid materials into the ECR ion
source and a new beam transport system for installation of a 14 GHz ECR ion source (named a Hyper ECR
ion source).
A beam of metallic ions such as lOB 4+ was used forthe first experiment with the CRIB separator. The
ion beams were produced by two methods: rod insertion for feeding the vapor from a natural boron crystal
into the ECR plasma and introduction of the BF3 gas
containing enriched lOB atoms. Thus far, the beam intensities extracted from the ECR ion source and thoseof ions from the AVF cyclotron are about 1 ef.-LA and
100 enA for the boron crystal, and 5 ef.-LA and 1 ef.-LA
for the BF3 gas, respectively. To produce more intense
beams of lOB 4+, we have prepared a volatile materialof BlOH14 for the MIVOC technique. 2 )A new beam transport system has been installed at
the RIKEN AVF cyclotron in order to utilize the Hyper ECR ion source as a second external multicharge
ion source in addition to the conventional 10 GHz ion
source. Because the Hyper ECR ion source works witha higher microwave frequency and stronger magnetic
field than the conventional ECR ion source, the production of more intense beams of highly charged ion
beams was expected.
We installed the Hyper ECR ion source in the ion
source room of the AVF cyclotron in 2001. This
source had been previously developed, and was used
for atomic physics experiments at CNS Tanashi until 1998. We succeeded in producing intense beams
of highly charged ion beams (e.g. , 300 ef.-LA of l4N5+
and 60 e.uA of l4N 6 +) from this source. The source
was designed to operate at 14.25 GHz microwave frequency. The axial confinement of plasma was obtainedwith two solenoid coils that provide the magnetic mirror field. The solenoid coils are fully enclosed with an
ion yoke to reduce the coil current. Electrical power
consumption is nearly 60 kW. The mirror ratio is
about 2.6 (Bmax rv 11 kG and Bmin rv 4.2 kG). To confine the plasma radially, we used a sextuple magnet
constructed using Nd-Fe-B permanent magnets. The
Center for Nuclear Study, Graduate School of Science, University of Tokyo

256

field strength at the surface of the magnets was about
11 kG. Details of the design of the Hyper ECR ion
source have already been described. 3)
The beam transport system of the Hyper ECR ion
source were designed and placed in the ion source roomin 2000- 2001. The system consists of four elements:
one pair of quadruple magnets for optical matching between the source and the beam line, a double-focusing
analyzer with the bending angle of 90 and the bending radius of 50 cm, a solenoid magnet for focusing,and a rotatable 90 0 bending magnet for switching thetwo ECR sources. A schematic drawing of the final
setup is shown in Fig. 1 and a list of the elements with
their specifications is given in Table 1.
A rotatable bending magnet has been installed upstream of the axial injection line of the cyclotron. Thismagnet is used to deflect the beams by 90 0 from thehorizontal line to the vertical axial injection line. It
can rotate the beam direction with respect to the center axis of the cyclotron and the entrance side can beconnected to each ECR beam transport line. The magnet has been used with good transmission efficiency of
the 10 GHz ECR ion beam.
To reduce the losses of the beams transported fromthe ion source to the cyclotron, we have made three improvements in this system, as follows. (1) To increase
the beam extraction voltage of the source to 20 kV, the
new transport system was designed with a maximum
magnet rigidity of approximately 118.5 kGcm. (2) The
source was set close to the beam analyzer by putting
0

QI ,Q2
BM
ST
S
Fe
PM
SOL
RBM

Quadrupole Magnet
Analyzing Magnet
Steering Magnet
Slit
Faraday Cup
Beam Profile Monitor
Solenoid Lens
Rotatable Bending MagnetomFig. 1. Top view of the Hyper ECR ion source and thebeam transport line to the rotatable bending magnet.
The beam line was set to have a 20° deviation angle
from that of the conventional ECR.

Table 1. Summary of beam analysis system and beamtransport elements.
Drift to analyzing magnet
Quadrupole magnets

Analyzing magnet

Drift to image slits
Solenoid

Bending magnet

108.5cm
G = 0.24kG/cm (I = 20A)
pole length = 10 cm
pole gap = 12.1 cm
bending angle = 90°
radius = 50 cm
gap = 8cm
Bmax = 2.37 kG (I = 220 A)edge angle = 29.6° both
entrance and exit
magnification = 1
108.5 cm
length = 20 cm
bore radius = 12.4 cm
Bmax = 2.5 kG (I = 100 A)
bending angle = 90°
radius = 50 cm
gap = 8cm
Bmax = 1.5 kG (I = 102 A)edge angle = 29.6° both
entrance and exit
magnification = 1

together the extraction point of the source and the 0 bject point of the analyzer. (3) A pair of quadruple
magnets was set between the source and the analyzer
to focus emitted beams from the source. In addition,
another coil was attached to each pole of the quadruple
magnet to correct the beam deflection caused by theuncontrollable leakage field from the cyclotron main
magnet.
The design parameters of the beam injection line of
the cyclotron were optimized by using the emittancematching calculations for the beam injection throughthe axial hole (hole lens) to the inflector entrance.
The assumed beam emittance was 1387rmmmrad in
the horizontal plane and 917rmmmrad in the vertical plane. This emittance was the measured value
with the beams from the Hyper ECR ion source at
eNS Tanashi. Figure 2 shows the envelopes of the

Horizontal beam envelope 1m] versus distance 1m]

Vertical beam envelope 1m] versus distance 1m]

Betatron envelope _ _Momentum envelope

Note: Linear optics

Fig. 2. First-order beam envelope along the injection line
calculated for the 14N5+ beam: Bp = 30 kGcm.

beam in both transverse planes calculated with the
WINAGIL.4)
We have installed the Hyper ECR ion source and thebeam transport system at the RIKEN AVF cyclotron.
We can deliver a beam of highly charged ions to the cyclotron by operating two ECR ion sources. When one
source supplies the beam to the cyclotron, the othermay be used to test the next beam shift and develop
a new beam in order to enhance the beam intensities
of highly charged heavy ion beams. The beam test of
the new system is under way.
References
1) Y. Yanagisawa et al.: CNS Ann. Rep. 2000 , 11 (2001).
2) H. Koivisto et al.: Nucl. lnstrum. Methods Phys. Res.
B 94, 291 (1994).
3) Y. Yamashita et al.: Proc. 8th Symp. Accelerator Science and Technology, Wako (1991), p. 84.
4) P. Bryant, AC Division, CERN: private communication.

257

RIKEN Accel. Prog. Rep. 35 (2002)

Laser plasma for direct plasma injection to RFQ Linac
on RIKEN laser ion source
S. Ozawa, T. Takeuchi,*l T. Katayama, T. Nakagawa, M. Okamura, K. Yano, S. Kondrashev,*2
N. Mescheryakov,*2 and B. Sharkov*2
Recently, through a CNS-RIKEN-TIT collaboration, a new type of heavy-ion source that consists of alaser plasma source and a radio-frequency quadrupole
Linac (RFQ Linac) have been developed. In order todetermine the parameters of the ion beams injected
into the RFQ Linac by the direct plasma injection
method, measurement of the laser plasma properties
was carried out at the RIKEN laser ion source (RIKEN
LIS) .1)
A schematic view of the experimental set up is shownin Fig. 1. A 4 J TEA CO 2 laser with 100 ns pulse duration was used to produce the ablation plasma. The
feed gas mixture ratio was CO 2 : N 2 : He = 2 : 1 : 4. As
shown in the figure, the laser beam was transported by
two plain mirrors and injected into the target chamber that was designed and fabricated at the ITEP.2)
A NaCI window was used to create a vacuum in thechamber , typically 7 x 10- 4 Pa. The laser light wasreflected by another plain mirror which was placed in
front of the target. The reflected light was focused
onto the surface of the target using a focusing mirror. Subsequently, induced plasma passed through the
openings of the mirrors to the beam line. The target
itself was a bulk of carbon material which could be
rotated by a ratchet which coincided with the shot-byshot operation of the laser. The target chamber was
grounded and the produced plasma had very slow velocity. The plasma in the target chamber expanded
through a drift space to the electric analyzer system(see Fig. 2). At the entrance to the analyzer, ions wereextracted and guided to a detector. This electrostatic
analyzer was fabricated at the ITEP and was installed

F ig. 1. Experimental setup.
*1
*2

258

Center fo r Nuclear Study, University of Tokyo
Institute of Theoretical and Experimental Physics, Russia

1

TargetFig. 2. Structure of the electric analyzer.

Table 1. Design parameters of t he electric analyzer.
Geometry of plates:
Deflection angle:
Mean radius of the plates, RO:
Gap between the plates , Ro:
Geometric factor of the analyzer:
Maximum potential of electrodes:
Energy dynamic range:
Input slit: accuracy of control:
width range :Output slit: accuracy of control:
width range:
Detector (electron multiplier):
coefficient of multiplication:
applied voltage:

cylindrical90deg.
100mm
5mm
k = 2~oR = 10
U = ±20kV~ = 4 X 10 4
Emin
Db in = 2.5mm
bin = 5mm
Db out = 2.5 mm
bout = 5mm
Ceratronup to 10 8
Up to 4 kVin the RIKEN LIS. The main parameters of the analyzer are summarized in Table 1. The analyzed ionswere detected by Ceratron, EMT-6081B.
The current amplification coefficient of the Ceratrondetector is reported to be 108 at bias voltage = 4 kV.
Unfortunately, the reference gave no data for the electron amplification to low-energy carbon ions in eachcharge state. Therefore , we had to determine the dependence of the secondary electron emission coefficientof carbon ions on energy and charge states. We carriedout the calibration measurement using a Faraday cup.
The Faraday cup had an aperture of 50 mm diameterand a length of 250 mm, and was located at a distanceof 2.92 m from the target. From the measured current
signal and the Ceratron signal under the same experimental conditions, the ratio of the calibrated value(CR/FC value) to the real current was obtained.

A typical spectrum measured with Ceratron at a
distance of 4.43 m from the carbon target is shown in
Fig. 3. To clearly separate the peaks for each charge
state, the flight distance was set at 4.43 m. The signal
shape was averaged for 32 shots. The potentials of theelectrodes were set to ±8 V.
We can determine the velocities and beam energiesof the ions corresponding to each peak. Then, using
the ratio of the calibration value to the current value,
we can obtain the charge distribution and time variation of the ions contained in the laser plasma at a
distance of 264 mm from the target to the entrance of
the RFQ Linac, as described in Fig. 4. The fractionof the current value for each charge state of the ions isshown in Table 2.
The absolute values of the beam currents were estimated from the total current. In this measurement, aFaraday cup , with an aperture of 10 mm diameter located at a distance of 1.25 m from the target, detecteda current of 6.45 rnA. Using the formula 3) j ex: (¥) 3,
we can estimate the total carbon ion current under theconditions of the direct plasma injection method (a dis-

55

Tl

r'

'Ir

r '"

95
'I

11'1

135

~,...

H+

C J+

f'

6.0

Time (Jls)
Fig. 4. Pulse time structure for each charge state of the
carbon ions.

Table 2. Fraction in laser plasma and the current for eachcharge state of the carbon ions.

Fraction
Estimated
Current

Time (l1s)15

r- - - - - - - - - - - · - - - - - - - - - - - - - -+Fig. 3. Typical Ceratron signal.

47%

31 %

14%

8%

44.1 rnA

29.1 rnA

13.1 rnA

7.5 rnA

175"'1'll'I~'"

tance of 264 mm from the target , 4 mm aperture slit).
Land Lo are the distances between the target and thedetector with estimated current and measured current ,respectively. Estimated current values are summarizedin Table 2.
References
1) T. Takeuchi et al.: Proc. EPAC2000 (2000), p. 1622.
2) S. Kondrashev: RIKEN-AF-AC-15 (1999).
3) B. Sharkov et al.: Proc. EPAC96 (1996), p. 1550.

259

RIKEN Accel. Prog. Rep . 35 (2002)

Carbon beam acceleration using direct injection method
M. Okamura, T. Takeuchi,*l T. Hattori,*2 R . A. Jameson, and T. Katayama
For MUSES l ) the project at RIKEN, we studied the
RFQ linac to determine its ability to accept beams
from a laser ion source. 2) Generally, this type of pulsed
ion source can provide high-intensity heavy-ion beams
with highly charged states and is well suited for injection to synchrotrons. However, the beams from thelaser ion source have a broad energy spread, strong
space charge effect, and time variation of current,
which consists of various charge states. Also, the beamprofile changes dynamically.3) Due to the complex features mentioned above, it is extremely complicated todesign a low-energy transport line between the source
and the first-stage accelerator which usually consists ofan extraction system and specially fabricated focusing
devices. 4 ) In order for the RFQ linac to accept pulsed
intense beams from the laser ion source, special attention should be paid to the design of the injection
scheme of the RFQ.5) In this paper, a completly new
injection method will be introduced and the results ofthe verification experiment will also be reported .
Using a 4 J TEA CO 2 laser with 70 ns pulse duration,
the basic parameters of an expanding plasma have beenmeasured. The irradiated power density was estimatedto be lOll W /cm 2 and the measured divergence of an
expanding ablation plasma was less than 20 degrees. 6 )In the case of a carbon target, we obtained several tensmA of C 4 + beam at a distance of 3 m from the target.
An efficient method of injecting a high-current beam
into an RFQ must be investigated.
The beam emittance from the laser source is mainly
determined by emittance growth due to the strong
space charge effect. If we consider only the expanding
shape of plasma which has a 0.3 mm radius laser spot
on the target and 20 degrees of divergence, the normalized beam emittance of ions in the plasma would
be only about 0.0577r mm mrad.
In order to reduce the space charge effect in the initial beam from the source, a direct injection method
has been proposed. A 's chematic view of the injection
system is shown in Fig. 1. The laser target is locatedin a vacuum chamber which is directly connected to an
RFQ but electrically isolated. After the laser hits thetarget, ablated plasma expands in the target vacuum
chamber under the high-voltage power supply, and theplasma enters directly the RFQ channel. At the entrance of the RFQ , the electrons in the plasma will bedeflected and only the ion beams will be trapped by
the RFQ focusing force. Finally, the injected intense
beam will be accelerated to the designed energy.

RFQ

Target Chamber~--------------------~

Fig. 1. Schematic view of the direct injection method .

In order to verify the feasibility of this scheme,an acceleration test was carried out using TITech
RFQ.7) This heavy-ion RFQ was originally designed
for medium-current beams and is not appropriate
for accommodating the intense beam from the laser
source. In this experiment, it was utilized in orderto prove the principle of the direct injection method.
The main design parameters of the RFQ are listed inTable 1.
A conceptual layout of the experimental set up isindicated in Fig. 2. The laser beam, emitted from the
TEA CO 2 cavity, was guided by two planer mirrors
and then focused onto the carbon target by a concave

Table 1. Main parameters of the TITech RFQ.
Designed Values
Charge-to-mass ratio
Operating frequency (MHz)Input energy (keV jamu)
Output energy (keV jamu)
Normalized emittance (100%)(cm . mrad)
Vane length (cm)
Total number of cells
Characteristic bore radius, TO (cm)Synchronous phase, cPs
Transmission
for q/A = 1/16 beam lOrnA input~ 1/1680

52140.057r

422
273

0.466
-90 0 ---+ -20 0
6 .84 rnA

RFQ

Target Chamber

TEA C02 Laser
*1

*2

260

Graduate School of Science, University of Tokyo
Research Laboratory for Nuclear Reactors, Tokyo Instituteof Technology

Laser beam

Fig. 2. Layout of the experimental setup.

donut-shaped mirror , which is installed between thetarget and the RFQ cavity. The ablation plasma is
induced from the target surface and expands, passing through the hole of the concave mirror and then asmall slit. This slit, ¢ = 4 mm, is aimed at scraping
the excess plasma that cannot fit into the beam channel of the RFQ , and is placed very close, 6 mm fromthe electrodes, to the RFQ. Only a small portion of
the ablated plasma, estimated to be about several hundreds rnA of the beam current, can enter the RFQ. In
order to adjust the velocity of the carbon ions to thedesigned value of the RFQ , high voltage was supplied
to the target chamber.
The accelerated carbon beam was observed successfully at the Faraday cup located next to the RFQ.
The measured peak current reached 25 rnA, as shownin Fig. 3. The observed ion current clearly reflects
the bunch structure of the accelerated beam due tothe short distance between the RFQ and the Faraday
Cup. This means that the beam current shape shownin Fig. 3 represents the envelope of the peaks whichappear at RF cycles of 80 MHz. The observed peakcurrent of 25 rnA can be converted into the averaged
peak current of 8 rnA. For this measurement, the target was at 20 kV. It is expected that the current measured at Faraday cup (FC) 1 contains C3 +, C4 +, andC5+ which have injection ion velocities greater thanthe design value. The analyzed beam current at FC 2
is shown in Fig. 4.

rnA

I
I

rnA

I

I

I

,

I

,

I

,

I

,

I

I

I

,

I

,

__ L_.1 __'__ L_

4_.1 __'__ L _3-+-~-+---~-+-~-+-

2_.1 __I__ L ___ L_.1 __'-_L_

I
I

,
,

,
I

I

I

I

I
I

I
I

I
I

I

I

I

-~-~-T-

,
,

,
I

,
I

I

I

I
I

I
I

I

I

-r-~

,
I

,
I

I

I

I
I

I
I

I

I

~-T-

8 IlS

Fig. 4. Analyzed C 4 + beam.

The triplet of quadrupole magnets was optimized toobtain the highest current. The distance between the
FC 2 and the RFQ is sufficient to de bunch the beam.
The effect of the bunch structure on the current is notnecessary to take into account. The measured peakcurrents were 3.9 rnA and 1.6 rnA for C 4 + and C 3 +,respectively. The TITech RFQ was optimized to get
6.8 rnA of a q/ A = 1/16 beam. In the case of C 4 +,q/ A = 4/12 , the space charge effect was behave morethan twenty times stronger. The numerically predictedvalue was 1.85 rnA, which is much lower than the experimentally achieved current of 3.9 rnA. It was foundthat the direct injection method is effective for the laser
ion source.
In order to capture the intense ion beams from alaser ion source, the direct injection method has been
proposed. The first accelerated carbon beam was successfully observed and the obtained current was muchhigher than expected. This method is useful for utilizing the intense beam from a laser ion source.

24---~--i---~--i---~---

20---~--~---~--~---~---

References---~--1---~--1---~---

1) T. Katayama et al.: Proc. EPAC2000 (2000), p. 68.
2) B. Wolf: in Handbook of Ion Source (CRC Press, Boca
Raton , 1995) , p. 147.
3) P. Fournier et al.: Rev. Sci. Instrum. 71, 924 (2000).
4) P. Fournier et al.: Proc. Particle Accelerator Conf., NewYork , USA , 1999-3 (1999), p. 103.
5) M. Okamura et al.: Proc. EPAC2000 (2000), p. 848.
6) T. Takeuchi et al.: Proc. EPAC2000 (2000), p. 1622.
7) M. Okamura et al.: Nucl. Instrum. Methods Phys. Res.
B 99 , 694 (1995).

I
I

I
I

I
I

I
I

I
I

I
I

I
I

I
I

I
I

I
I

I

I

I

I

I

I

I

I

I

I

--~--~---~--~---~---

I
I
I
I
I
I __ I ___ IL __ I ___ IL __ _
_L
~

I
I

I
I
I

--,
I

~

I
I
I

I
I
I

I
I
I

I
I

I
I

,---r--!!S

Fig. 3. Measured current at at FC 1.

261

RIKEN Accel. Prog. Rep . 35 (2002)

Development of long-lived carbon foil for charge stripper
in RILAC
H. Hasebe,*l 1. Sugai,*2 H. Akiyoshi, and M. Kase
Carbon foils (C-foils) are extensively used as charge
strippers for heavy-ion beams. However, C-foils havethe serious disadvantage of having a short lifetime witha high-intensity heavy-ion beam. The C-foillifetime isvery short in the RIKEN RI Beam Factory (RIBF).
Therefore, the production of long-lived C-foils is urgently required for the RIBF project. A large amountof progress has been made in developing long-lived Cfoil product ion techniques . We are planning to produce
a self-sufficient number of long-lived C-foils according
to the techniques presented in Ref. 1.
C-foils with a thickness of 10 f.Lg/cm 2 were producedby the arc discharge evaporation method. The arc discharges were generated by AC voltage as well as by
DC voltage. Figure 1 shows the interior view of thevacuum chamber. The AC and DC arc discharge evaporation sources are placed in the middle of the vacuum
chamber. The angle between the direction of the arc
discharge and the horizontal plane was varied from 0
to 45 degrees. The discharge currents used were 300 A,
350 A, 400 A, 450 A, and 500 A. The thickness of the
C-foil was continuously measured by a quartz crystal
thickness gauge . The gauge was calibrated by measuring the mass and the area of the C-foil. Two resistanceheated sources for releasing the agent were placed inboth sides of the vacuum chamber. A substrate rotation mechanism was used in order to make the film
t hickness uniform. The angle between the substrates
and the horizontal plane was varied according to theposition of the evaporation source.
The durability of C-foils under beam irradiat ion wasFig. 2. Photograph of C-foil folder in vacuum chamber. A
10 f,-Lg/ cm 2 C-foil was mounted on the folder.

Fig. 1. Interior of the vacuum chamber.

o AC
•

l5
~

.'l

~

(,
o

35
30
25

~

20

&1

15

~

DC

10

300A

350A

400A

450A

500A

Discharge current(A)Fig. 3. Dependence of C-foil lifetime on the discharge current .
*1
*2

262

SHI Accelerator Service, Ltd.
High Energy Accelerator Research Organization (KEK)measured. A 32 keY lu 136Xe9+ beam with an intensityof 1.1 pf.1A from a 500 kV terminal was focused on a Cfoil. The beam spot is rectangular with a size of 5 mm x
5 mm. The beam spot was carefully made to form a
uniform beam. The break of the C-foil was detected by
the beam current measured downstream of the foil andalso by observing the foil using a TV camera. Figure 2
shows a C-foil mounted on an aluminum folder in thevacuum chamber. This chamber was set on the beamline. The C-Foil folders of 40 sheets moved within thechamber automatically. The lifetime of commerciallyavailable C-foils (Arizona Carbon Foil Co.) with thesame thickness was measured to be 60 s on average .
This lifet ime is taken as the standard in this work.
Figure 3 shows the dependence of the C- foil lifetimeon the discharge current. The longest lifetimes were
measured when the current was 450 A in the case of
the AC discharge, and 300 A in the case of the DC

discharge. We successfully produced a C-foil whose
lifetime was 40 times longer than the commercial foil
when the discharge current was AC 450 A, there was 0
degrees between the direction of the arc discharge andthe horizontal plane, and OT-5200N(S) graphite rods
and a releasing agent of NiCh were used.
The conditions for production of a long-lived C-foil
have been determined. The preparation of C-foils withan increased thickness of 80 f.1g/cm 2 is now in progress.
We will soon test this C-foil with a few Mev l u intense heavy-ion beam in the realistic case for the RIBF
project.
References
1) 1. Sugai , M. Oyaizu, H. Kawakami, C. Ohmori, T.
Hattori, K. Kawasaki , M . J. Borden, and R. J. Macek:
Nuel. lnstrum. Methods Phys. Res. A 362, 70 (1995).

263

RIKEN Accel. Prog. Rep . 35 (2002)

Low-energy beam test of liquid film charge stripper
H. Akiyoshi , T. Chiba, H. Hasebe,* M. Kase, and Y . Yano
A charge stripper plays an essential role in heavy
ion accelerators. With the higher intensity and highmass beams of the RIKEN RI Beam Factory (RIBF),
commonly used carbon stripper foils are expected tobreak within short lifetimes. In order to overcome thestripper foil lifetime problem , a charge stripper systemusing a thin oil film has been developed.
A liquid film with a large area was produced by arotating disc touching the surface of silicone oil , asdescribed in the last report .1) The motor of a t urbomolecular pump which rotated the disc was replacedby an AC servo motor which was placed outside thevacuum chamber. The motor rotates the disc througha ferrofluid sealed rotary motion feedthrough. The replacement of the motor allowed beams to pass through,enabling us to perform the beam test. Figure 1 shows aphotograph of the liquid film. The slanting dim whiteline from the middle to the upper left of the photograph shows the upper edge of the liquid film.
A low-energy beam test of the liquid film stripper
was performed using a Cockcroft-Walton inj ector of
the RIKEN heavy ion linac (RILAC).
Figure 2 shows a schematic layout of the experimental setup. 4He+ ions at 500 keY were focused on thethinnest area of a liquid film by observing the fluorescent image of the beam on a quartz plate in front of
the liquid film. The thickness distribution of the liquidfilm was observed by means of an optical interference
pattern of visible rays . The beam spot had a nearlyround shape, and the diameter was about 6 mm. A
blue fluorescent image of the beam was also observedon the liquid film itself when a high-intensity beam
was bombarded. It is probable that a certain number of 4He+ ions pass by the liquid film because thebeam was focused nearly on the upper edge of the film.
When beam intensity was increased , the upper edge ofthe film was broken like a waterfall into which a log
was thrust . This increases the numbers of helium ionswhich pass by the liquid film. Some of the helium ionsare likely to be charge-exchanged by oil mist or otherresidual gases without passing through the liquid film.
The energy of these helium ions is 500 ke V , the sameas that of incident helium ions, while the energy ofthe helium ions which passed through the liquid film
is somewhat lower than 500 keY because of the energy
loss in the liquid film. Therefore, roughly speaking,
4He+ and 4He 2 + ions with two energies emerge fromthe stripper system.
The helium ions that emerged from the stripper
were inj ected into a parallel-plate electrostatic deflector, and split according to their energy and charge
state. A beam stopper was placed behind the electrostatic deflector. The beam stopper was divided intonine blocks in each two degree as plotted in Fig. 2,
and the current of incident helium ions on each block
was extracted separately. The currents were measured
by varying the voltage of the deflector.
Figure 3 shows the differences in the deflector volt-

30

0

2S

20

>

'"

15

0
0

>
10

10

Fig. 1. Photograph of liquid film.

12Angle (deg r ee)

4 He+' 2+

4He------~~=-------I-LIQUID FILM

-HV

:::1

BEAM STOPPER

Fig. 2. Schematic layout of experimental setup.
SHI Accelerator Service, Ltd .
ACF-Metals, The Arizona Carbon Foil Co ., Inc.

264

Fig. 3. Sorted helium ions by electrostatic deflector according to their energy and charge states . The horizontal
axis indicates the deflection angle, and the vertical axis
indicates the voltage of the deflector . Squares and d iamonds indicate the data measured with a liquid film
produced by 1600 rpm disc rotation and a 80 f.Lg /cm 2
carbon foil,a respectively. Circles indicate the data obtained without any stripper.

ages according to the energy and the charge states of
the helium ions coming to each block of the beam stopper. The data points roughly form four lines. It is
probable that these lines correspond to, from the upper line to the lower line, the 4He+ ions which passedby the liquid film (first line), the 4He+ ions which
passed through the liquid film (second line), the 4He 2 +ions which passed by the liquid film (third line), andthe 4He 2 + ions which passed through the liquid film
(fourth line). Therefore, one can estimate the thickness of the liquid film at the beam position from thedifference between the first and second lines. The interpretation of the lines was checked by observing thedata points of 80/-Lg/cm2 carbon foU a that lay closelyon the second and fourth lines which had been fitted tothe data points of the liquid film produced by 1600 rpm
disc rotation.
The thickness of the liquid film varies as a functionof the rotating frequency of the disc. Derived thicknesses are plotted in Fig. 4 as a function of the rotating frequency of the disc. When the disc is rotated
at 1500- 1800 rpm, the thickness of the liquid film at
the thinnest area is such that it is suitable for use asa charge stripper for ions with energies of about 46 MeV /nucleon. 2 )

I

N~

I

I

175 f--

150 f--

125 f--

100 f--.......

E
c

~

-

75 f-

I
1200

I
1400

1
1600

I
1800

f (rpm)Fig. 4. Thickness of the liquid film as a function of rotating
frequency of the disc.

10

'

10 0

I

I

I

I

I

I

I
10

I

I

20

50

I

r-

IO - I b0c

10 - 2 b-

10- 3 b-10- 4

Beam Intens i ty

100

(1lA)

Fig. 5. The current of 4He 2 + ions which passed through theliquid film divided by the current of 4He+ ions which
passed by the liquid film as a function of beam intensity measured by a Faraday cup placed upstream of the
stripper. The disc was rotated at 1500 rpm.

Figure 5 shows ratios of the current of the 4He 2 + ionswhich passed through the liquid film to the current of
the 4He+ ions which passed by the liquid film in thecase of 1500 rpm disc rotation. As beam intensity wasincreased, the upper edge of the film was broken. Thissignificantly decreases the ratio as is seen in Fig. 5.
The limit of beam intensity is estimated preliminarily
to be about 10/-LA , which corresponds to a power density of 8 W /cm 2 . If a 5.85 MeV/nucleon 13 6 Xe beam
has the same beam spot size, this limit value corresponds to the beam current of 300 pnA. In the case of
0.9 MeV /nucleon 238U , the limit value corresponds to200pnA.
We are presently preparing for a higher energy
beam test at RILAC in order to measure the equilibrium charge state distribution and obtain more practical information about durability against high-intensity
heavy ion beams.
References
1) H. Akiyoshi , T. Chiba, M. Kase, and Y. Yano: RIKEN
Accel. Prog. Rep. 34, 315 (2001).
2) E. Baron: IEEE Trans. Nucl . Sci. 26, 2411 (1979).

265

RIKEN Accel. Prog. Rep. 35 (2002)

Control system for RRC, AVF and RILAC
M. Kobayashi-Komiyama, 1. Yokoyama, M. Nagase, E. Ikezawa, M. Fujimaki , R. Abe,*T. Tanabe, and M. Kase
The control system of the RIKEN Ring Cyclotron(RRC) and one of its injectors, AVF Cyclotron, hasbeen replaced in the new system using the Experimental Physics and Industrial Control System (EPICS) 1)
and has been used since April, 2001. The details oft his project and the system development are shown in
Ref. 2. By this system renewing, the M60/ AR Mitsubishi minicomputer , which was a host computer in theprevious system, has been used no longer for the beam
operation. However, the previous system has anotherM60 minicomputer for the operation of the RIKEN
Heavy Ion Linac (RILAC), the other inj ector of theRRC, which also needs to be replaced.
The M60/500 used for the RILAC operation controls
the CAMAC-CIM/DIM system 3 ) and the GP-IB system. The CAMAC-CIMjDIM system controls somemagnet power supplies and some beam diagnostic devices. It is able to control the CAMAC-CIM/DIM
system only by adding the operational data into theexisting Oracle database. On the other hand , GP-IB ,which is a new device of our EPICS for RRC and AVF
control, controls some power supplies for the magnets
and for the RF system from the first tank to the fourthtank of the RILAC. Thus, we need to develop anotherjillUU~TVSW I

device support for GP-IB. There are no significant
differences in the construction of the EPICS databasebetween a CAMAC-CIM/DIM system and a GP-IB
system. Therefore , the device support for the GPIB device was developed in the same way as the device supports for the CIM/DIM. Their operation wastested using the same kind of GUIs as the CAMAC
system and it was succeeded last summer. We are to
replace the M60/500 system in the EPICS within thisyear.
Furthermore, a part of the new introduced system of
the RILAC facility has also been controlled by EPICS
since April, 2001. The project on energy upgradingof RILAC has started several years before, and thebeam transport system of the RILAC facility has been
replaced in the new system in summer of 2000. 4 ) In thissystem, a network I/O (NIO) systemS) was introduced
to control the new power supplies. The device supports
for NIO were also developed by ourselves.
Figure 1 shows the structure of the control systemof the RIKEN Accelerator Research Facility (RARF)
using EPICS. In our control system, one HP-UX 11.0
machine works as a server and several PCs work as
clients. This server machine was introduced to ourSony CCD-G100ST
Camera (Fixed)

J1Wlill' SGSW I

Canon VC-C4
Camera (Move):', "1
[II
IEmII

0-10V
(Beam Current)-_.. .,= --~ Video Out=;:> ~~

Video Carcr- - - - - - - - - - - - - - - - 'AID Board ATI RADEON

Video Signal

100Base-TX(Beam Spot)EPICS LANDELL Dimension 8100
DELL Dimension 8100
Pentium 4 1.7GHz
MEMORY 512MB
Pentium 41 .8GHz
MEMORY 512MB, Windows 2000 Windows 2000

Mon itor Changeover Switch
DELL Dimension 8100
Pentium 4 1.8GHz
MEMORY 512MB
Windows 2000
Video Card ATI RADEONRRC Control Area

AVF Cyclotron Control Area

Fig. 1. Structure of the RARF control system using EPICS.
SHI Accelerator Service, Ltd.

266

RARF Control System Using EPICS
on OS/Nov/2001

rarfsrv

Linac build.

Nishina build.

rarf-lin1• PC (LiNUX)• Pentium 3

PC (Windows2000)

Media Converter

I Air Blown Fiber• System Mon~orFig. 2. Client PC configuration for EPICS at the RRC control room.

system last October instead of the HP-UX 10.20 workstation to make the control system more stable. All
EPICS databases and EPICS sequencers, which are
written in the state notation language for sequential
operations, are loaded on several VME computers fromthe server computer. An operator connects his PC
to the HP- UX server machine, and controls accelerator devices by communication with objected EPICS
records on the VME computer. There are five VME
computers in our system as shown in Fig. 1. The vxTargetl controls all CAMAC-CIMjDIM devices in the
AVF and the RRC system. The vxTarget2 controls
all CAMAC-CIMjDIM devices and GP-IB devices in
the RILAC system. The vxTarget3 controls the RRC
users' system, SMART (E4) and RIPS (E6), and thevxTarget5 controls all the magnet power supplies controlled by NIO in the RILAC system. The vxTarget4 isused only for the system development. Currently, there
are more than 20,000 EPICS records on the vxTarget1.
This number is too big. However, it is difficult to separate these records into two and to load them to plural
VME computers, because it is difficult to divide the
CAMAC control loop in two. Therefore, we are using
the VME CPU module which mounts 128 MByte memory for vxTargetl for operation without resource troubles. Approximately 50% of the memory is used in constant, and we can continue beam operation smoothly.
The vxTargetl and the vxTarget2 have CPU modules
which mount 128 MByte memory, and the others have

CPU modules which mount 64 MByte memory. Since
the amounts of EPICS records in the vxTarget2, vxTarget3, vxTarget4 and vxTarget5 are smaller thanthat in the vxTargetl , our system has sufficient capacity.
Figure 2 shows the client PC configuration for
EPICS at the control room in the Nishina building.
At the present, almost all RRC devices connected to
the CAMAC-CIMjDIM system can be controlled by
EPICS. Beam operation is carried out by using each
GUI and the condition of the magnet power supplies ismonitored every 10 s using one of the standard EPICS
host tools , Alarm Handler (ALH). It tells us unexpected malfunctioning of the power supplies by beeping. Furthermore, the beam intensity is measured bya Faraday cup every 200 ms and always shown on thetrend graph on PC at the control desk.
We are to control all beam devices which compose
the RRC and the RILAC system using EPICS in thenear future.
References
1) http://www.aps.anlgov /epics/2) M. Kobayashi-Komiyama et al.: RIKEN Accel. Prog.
Rep. 34, 318 (2001).
3) T. Wada et al.: Sci. Papers LP.C.R. 79, 28 (1985).
4) E. Ikezawa et al.: Proc. 13th Symp. Accelerator Scienceand Technology, Suita (2001), p. 169.
5) http://elc.aska.or.jp/denshi/system/kasokuki/

267

RIKEN Accel. Prog. Rep. 35 (2002)

Measurement of an open-loop transfer function ofa feedback control system of cavity voltage
Y. Chiba, O. Kamigaito , and N. Sakamoto
An open-loop transfer function of rf-amplitude modulation was measured for an rf system of the booster
linac in the charge-state multiplier (CSM), 1) using a
network analyzer along with a simple circuit based ona conventional op-amp. The measurement, which was
performed under t he high-power operation in cw mode ,has shown that the feed back control system meets therequirements of the stability condition over a wide
range of gap voltage.
F igure 1 shows a simplified block diagram of the
feedback control system of the cavity voltage. The
voltage is detected by a pickup electrode and transferred to a level controller through a 50-ohm cable.
The level controller first demodulates the pickup signal, and then compares it with a reference voltage
which is set according to the required voltage of thecavity. The resultant error voltage passes through aloop amplifier. The rf signal from t he signal generator is attenuated according to the amplified error ,and transmitted to the cavity through the rf-amplifier
chain. This loop is represented by a solid line in Fig. 1.
There are two main components that characterize
the open-loop transfer function; t he cavity and theloop amplifiers. The cavity response to the amplitude
modulation has the property of a simple low-pass filter. Using the loaded Q-value QL, it is written in thefollowing form;(1)
where f and f e are the modulation frequency and the

LEVEL CONTROLLER (Thamway AOSl-l067)~~--------------------------~

RF75.5 MHz

G=RIT

Loop
Amplifier- lRTrf frequency, respectively. The loop amplifiers are designed to stabilize t he cavity voltage as much as possible while keeping the feedback loop in a stable condition. In the level controllers of the CSM, two loop amplifiers, denoted by Loop Amplifier-1 and -2 in F ig. 1,
are dominant in the low modulation frequencies. The
former is based on a low-pass filter with phase lag compensations, as shown in Fig. 2. The latter is a singlepole low-pass filter whose time constant is lOl1s.
In the real system, however , other factors such ast he characteristics of the modulator, demodulator andt he op-amps used in t he level controller contribute thefeedback performance, particularly at the high modulation frequencies. These effects cannot be estimatedeasily, since they are sometimes dependent on the cavity voltage and the circuit environments. Therefore, it
is important to measure the transfer function directly
during cavity operation.
The method we used in the measurement is ill ustrated in Fig. 1. A measurement circuit is inserted
into the feedback loop. Through this circuit, amplit ude modulation of frequency f is added with a network analyzer (Hewlett-Packard HP4195A) to t he rf
signal. The network analyzer also det ects the signals
on t he loop at two points, denoted in Fig. 1 by T andR, respectively. It finally calculates the ratio of thesignals, yielding the open-loop transfer function G(f)by G(f) = R (f)/T(f), where T(f) and R(f) are thetransferred and the detected amplitudes, respectively.
Figure 3 shows the measurement circuit in detail.
It is based on a conventional op-amp (National Semiconductor TL082). The voltage gain from the positive
input to the output is chosen to be 1.0, while that fromthe negative input to the output is - 0.1. The input
impedance of the positive input is adjusted to that of

Loop
Amplifier-2

0. 111
470

0.111

4.7 k

0 .1 11

47 k

0.111

470k

+

Fig. 1. Simplified block diagram of t he feedback control
system of cavity voltage of the CSM.

268

Fig. 2. Schematic drawing of a loop amplifier in the CSM
level controller ,2) denoted by Loop Amplifier-l in Fig. 1.

HP4195A
port "R"100

HP4195A
port "T"

-=-

-=-

IO.1~

- - - ---

so

High-Z probe
HP85024A~~""""'1""'

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BNC

0

c:l

~~

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previous
stage

next
stage

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- - - - - A xG cav xG/. a. 1xG/' a.2---Vg=140kV-sor- ----- Vg = 180 kV

910
HP4195A
port "S"--Vg=300kV

-15V

9.1k

1111 11111 1III11111 11111 1111

-100

10
100
1000
Modulation Frequency (Hz)0.1
10 Hz - 100 kHz

6 dBm: 10 - 500 Hz

10

5

51
200

-3 dBm : 500 Hz - 100 kHz

-.
-'-

100

Fig. 3. Schematic drawing of the measurement circuit.

14

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,.

Lt.
I~

-.~

o

~

s

\ [\

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the following op-amp in order not to change the feedback loop with the insertion.
The frequency range of the measurements is set to be
10 Hz to 100 kHz; 10 Hz is the lowest frequency available with the network analyzer. First, it was confirmedthat the amplitude and the phase of the voltage gainsof the measurement circuit are constant within 0.01 dB
and 1 degree, respectively, in this frequency range.
The measurement was performed in the A3 cavity of the CSM booster whose resonant frequency
is 75.5 MHz, at three voltage levels; 140, 180 and
300 kV. The measured transfer functions are given in
Fig. 4. Although they are affected by noise in the lowfrequency region, almost the same curves have beenobtained for the three voltage levels. It is also remarkable to see that the values of the phase margin remainaround 30 degrees, which means that the stability conditions are well satisfied.
In Fig. 4, the calculated transfer function is also illustrated, which was obtained by multiplying the cavity response (1) and the transfer functions of the twoloop amplifiers shown in Fig. 1. In the calculationof the gain, a constant factor has been introduced sothat the calculated value can fit the measured results
at the lowest frequency (10 Hz). The predicted value
reproduces the phase and the slope of the gain in the
low-frequency region well. The differences in the highfrequency region can be attributed to various factors,some of which are mentioned above.
The procedure described above is applicable to all~'" -1 00-200

r- - - - - - GcavxGI.a.lxG/.a.2- - -Vg= 140kV-----Vg= 180kV- - V g = 300 kVt-111111111

-300
0.1

111111111

111111111

10

100

1000

Modulation Frequency (Hz)Fig. 4. Bode diagrams of the open-loop transfer functionsof the rf-amplitude modulation. Solid and dashedcurves are the measured ones. The dotted curve is thecalculated transfer function , which is given by the cavity and the two loop amplifiers in Fig. 1. In the calculation, the loaded Q-value of the cavity response was set
for the measured value of 12 ,500.

rf-control systems of this kind. It provides real transfer functions directly during high-power operation. If
an rf-control system is equipped with the above circuit
for a small expense, it would be useful for the optimization of the feed back performance as well as forthe diagnostics of the system.
References
1) O. Kamigaito et al.: Proc. 13th Symp. on Accelerator
Science and Technology, Suita (2001) , p. 229.
2) Thamway Co., Ltd.: Circuit Drawing, No. T20C99A30182A, April 2001.

269

RIKEN Accel. Prog. Rep. 35 (2002)

Development of multi-injection system for the AVF cyclotron
T. Kageyama, Y. Ohshiro,* M. Kidera, T. Nakagawa, and M. Kase
The AVF cyclotron was constructed for use in experiments using a beam with a few MeV lu of energy
or as an injector of the ring cyclotron (RRC) in 1988.1)
Through collaboration between RIKEN and the Center for Nuclear Study (CNS) of University of Tokyo,
the Hyper ECRIS 2) of CNS was installed in an injection room for the AVF cyclotron in 2001. Three ion
sources, Hyper ECRIS, RIKEN 10 GHz ECRIS and
RIKEN polarized ion source (PIS), could be used as
the injection source for the AVF cyclotron. The newmulti-injection system was constructed to allow compatibility between the development of a new ion beamand easy operation for operator.
The old system, consisting of two 45 0 bending magnets and three quadrupole singlets, is achromatic andbends the beam vertically down to the AVF cyclotron.
The new system consists of a dipole magnet, a steering
magnet and a beam monitoring chamber. This system

can be rotated 290 0 to give vertical axis of the cyclotron in order to bend two beams injected from the
10 GHz ECRIS and Hyper ECRIS. The performance of

Ion Source
Room 2F

Ion Source
Room IF~

ProfileSlit
monitor

Attenuator+-&om lOGHz ECRISNew Dipole Magnet

Table 1. Performance and parameters of the dipole magnet.
Rotation angle of magnet
Max. magnetic field
Radius of curvature
Bending angle
Width of coil gap
Max. operation current
Number of coil turns

290

0

0.15T
500mm
90

0

80mm
102.2 A
112

Fig. 2. Side view of the multi-injection system and polarized ion source (PIS) .

New Dipole Magnet

100Hz ECRIS

Fig. 1. Plan view of the RIKEN 10 GHz ECRIS , Hyper ECRIS and multi-injection system.
Center for Nuclear Study, University of Tokyo

270

the dipole magnet is shown in Table 1. Figure 1 shows
the plan view of Hyper ECRIS, RIKEN 10 GHz ECRIS
and the new multi-injection system. The two ECRISs
each have a beam monitoring chamber, and they areused for the development of a new ion beam. Figure 2
shows the side view of the PIS and the multi-injection
system. The new system can be rotated without breaking the vacuum in the vacuum chamber of the dipole

magnet and the monitoring chamber.
References
1) A. Goto et al.: RIKEN Accel. Prog. Rep. 22 , 202(1989).
2) Y. Yamashita et al.: Proc. 8th Symp. on Accelerator
Science and Technology, Wako (1991), p. 84.

271

RIKEN Accel. Prog. Rep. 35 (2002)

Construction of the flat-top acceleration system in the RIKENAVF Cyclotron
S. Kohara, A. Goto, O. Kamigaito , M. Kase, N. Sakamoto, S. Watanabe,* T. Katayama, and Y. Yano
The fiat-top acceleration system in the RIKEN AVF
Cyclotron was constructed and installed in August
2001 in order to improve the extraction efficiency
and energy spread of the beam. 1) The fiat-top accelerating voltage is generated by a superposition of
the fundamental and 3rd-harmonic frequencies. The
fund amental-frequency range is from 12 to 24 MHz, t he
3rd-harmonic-frequency range is from 36 to 72 MHz.
Fifth harmonics instead of 3rd harmonics can also be
used for this purpose. However , we decided to adopt
t he 3rd-harmonics mode instead of the 5th-harmonics
one for the following reason. In general, the power
loss can be less for the 5th-harmonics than for the 3rdharmonics, since the required amplitude of the 5thharmonics for fiat topping is about 1/ 25 of the fundamental frequency, while that of the 3rd-harmonics
is about 1/9 of t he fundamental frequency. Thus acold model test using superposition of the 5th harmonics was carried out three years ago. 2 ) Generationof fiat-top voltage over the entire frequency range wasconfirmed but the power loss of the resonator was notmeasured at that time. Prior to designing the real system, we again measured the rf characteristics in detailusing the model and found that the power loss for the
3rd harmonics was actually less than that for the 5th
harmonics.
Cross-sectional views of the system are shown in
Fig. 1. The newly added fiat-top resonator is coupled to the original main resonator with a coupling
Movable shoning plate

Flat-top resonator
Main resonatorcapacitor (Cc). It makes t he combined system resonate at both fundamental and 3rd-harmonic frequencies simultaneously.3) Rf power of the 3rd harmonics is
fed through a variable capacitor (Cf) , which matches
the input impedance of the fiat-top resonator to theimpedance of the feeder (50 0). The amplitude andphase of the 3rd harmonics are adj usted to produce
a voltage proportional to cos(wt)- 1/ 9 cos(3wt ) acrossthe dee gap . Tuning for the fundamental frequency
is performed in the main resonator and then that forthe 3rd harmonics is carried out with both a shorting
plate (L3) and coupling capacitor (Cc). These tunings
interfere with each other. The resonance of the 3rd
harmonics is kept constant automatically with a capacitive tuner of the 3rd harmonics by detecting theincident and refiected waves on the feeder line. The
stroke of t he capacitive tuner is 50 mm. A ceramics
insulator is used for support of the inner conductor of
the coaxial resonator as well as for achieving a vacuum seal. The fiow rate of cooling water for each of
the two fiat-top resonators is 9 1/min. A photographof the fiat-top resonator installed on the existing main
resonator is shown in Fig. 2.
Positions of the tuning elements t hat satisfy simultaneous resonance are measured with a network analyzer
for each resonant frequency. The measured positions of
the movable shorting plate and the movable coupling
capacitor of the fiat-top resonator are shown in Fig. 3
as a function of the 3rd-harmonic frequency. The optimum values for a combination of these two parameters
were researched in such a way that the transmission
efficiency (the ratio Q mentioned below) became thelargest. It was found that the 3rd-harmonic resonance
was limited below 63.3 MHz and did not reach the required highest frequency. For the frequencies higher
than 63.3 MHz , we plan to retest wit h a reduction in
the size of the coupling capacitor (Cc). Let v f be ther)I::L;:::~~.~
St'roke 40
L3

Vacuum capacIlor
4CW50.000E~

I

I Movable electrode Cc

I 15 X 15 stroke 5

I

A Feederfo~3rd h-;;~o~c;dIstroke 3

Insulator/
1-----,.-==...-.,~Hylr/')~~W~~'~':::::lIi::1~

tuner
Dee-voltage pickup

Unit; cm

o

50

100

Fig. 1. Cross-sectional view of the flat-top acceleration system for the RIKEN AVF Cyclotron.
Center for Nuclear Study, Graduate School of Science, University of Tokyo272

Fig_ 2. Photograph of the fiat-top resonator installed on
the existing main resonator.

1000

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800

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Third-harmonic frequency (MHz)Third-harmonic frequency (MHz)Fig. 3. Positions of the movable shorting plate and the coupling capacitor of the fiat-top resonator as a functionof the 3rd-harmonics frequency. Squares and circles
represent the positions of the shorting plate and thecoupling capacitor of the No.1 resonator, respectively.
Diamonds and triangles represent the positions of theshorting plate and the coupling capacitor of the No.2
resonator , respectively.

Fig. 5. Estimated power and the required maximum voltage of the 3rd harmonics. Circles represent the estimated power of the No.1 resonator and triangles represent that of the No.2 resonator. Solid line represents
1/9 of the required maximum fundamental acceleration
voltage.

-40

6
6

6

-42

Cii'

-44

/

J

0

0

0

~

n \J (
\

I

0

<:I
0

~

-46

Fig. 6. Typical waveform of the fiat-top voltage measured
by the dee-voltage pickup. The fundamental frequency
was 16.3 MHz and the 3rd-harmonic frequency was
48.9 MHz. The fundamental voltage was 50 kV.

6
-48

0

-50
35

40

45

50

55

60

65

Third-harmonic frequency (MHz)Fig. 4_ Ratio of the amplitude at the dee voltage pickup
to that at the feeder of the fiat-top resonator. Circles
represent the ratio of the No_ 1 resonator and triangles
represent that of the No.2 resonator.

voltage on the feeder of the flat-top resonator and Vm
be the output voltage of the dee voltage pickup. The
ratio a = vm/vf is measured at the 3rd-harmonicfrequency in simultaneous resonance. If impedance
matching at the feeder is made correctly, the necessary power of the 3rd harmonics for a dee voltage Pd
is given by (k·Vd)2/(2·z o ·a 2); here, Vd : peak voltage ofthe 3rd harmonics, k = Vm/Vd: pre-calibrated dividing
factor of the dee voltage pickup, and Zo : characteristic
im pedance of the feeder. Figure 4 shows the measured
ratio a. The estimated powers for the required maximum voltages of the 3rd harmonics are shown in Fig. 5.
The required voltage of the 3rd harmonics is definedas 1/9 of the required maximum fundamental acceleration voltage, which is determined mainly by the condition of the coupled operation with the ring cyclotron(RRC). The measured a and thus the required power

are different for the No.1 and No.2 resonators; thecauses of this difference are under investigation. The
measured frequency change covered by the capacitive
tuner of the 3rd harmonics was about 1%. The frequency change of the fundamentals was negligible inthis measurement.
The power test was carried out to generate a flattop voltage on the dee. Each power of the fundamental and the 3rd-harmonic frequencies were fed into theresonator at the same time. The parameters of the flattop resonator were set at their own optimum positions
as shown in Fig. 3. A typical waveform of the flat-top
voltage of the No.2 resonator is shown in Fig. 6.
A beam test using the flat-top acceleration system
will be performed in the near future.
References
1) S. Kohara et al.: Proc. 13th Symp. on Accelerator Science and Technology, Suita (2001), p. 235.
2) S. Kohara et al.: Proc. 12th Symp. on Accelerator Science and Technology, Wako (1999), p. 227.
3) J. L. Conradie et al.: Proc. 14th lnt. Conf. on Cyclotrons and Their Applications, Cape Town, South
Africa (1995) , p. 249.

273

RIKEN Accel. Prog. Rep. 35 (2002)

AVF-PA beam transport system
N. Fukunishi, M. Nagase, M. Kase, Y. Yano, T. Teranishi,* N. Yamazaki,* S. Watanabe, * and S. Kubono*
A high-resolution magnetic spectrograph, called PA,
has been installed in the E2 experimental vault as amajor facility of the Center for Nuclear Study (CNS)
at the RIKEN Accelerator Research Facility (RARF).
It was moved from CNS in the Tanashi campus where
it was frequently used for high-precision spectroscopic
measurements of nuclear structure and nuclear astrophysics studies. The spectrograph will be ready forexperiments by the fall of 2001. Construction of the
AVF -P A beam transport system has started to provide the beams accelerated by the K -70 Me V AVF cyclotron to PA. The schematic layout is provided inFig. 1. The beam transport system will be used asa momentum analyzer of AVF beams. Its use in thedispersion-matching mode is also planned. The maximum magnetic rigidity is 1.2 Tm. Last year, the firstsection of the AVF-PA beam line, which is shown withbold lines in Fig. 1, was constructed. The first section
mainly consists of two dipole magnets and five sets ofquadrupole magnets. This section shifts beams downby 4 meters to match the level of the AVF beam line
to PA and also shifts beams horizontally by 8.3 meters
to avoid interference with the RIKEN Ring Cyclotron(RRC). The unique feature of the section from the QDSTO to the QD-A21 is that the section is a skew beamline, which means that the horizontal beam shifting
section is rotated by 25.73 degrees in a vertical direction. The original horizontal beam shifting section consists of two dipole magnets and four sets of quadrupole
magnets , which form a doubly achromatic and doubly
telescopic section with negative unity magnifications.
Hence, we are free from complicated coupling between
the horizontal and vertical motions when we rotate thebeam lines vertically.
Specifications of the newly fabricated magnets are

summarized in Tables 1 and 2. The shape of thequadrupole magnet is the same as that used in RARF
(Q170 type). The dipole magnets are newly designed
based on magnetic-field calculations with OPERA-2Dand OPERA-3D. The cross-sectional shape and the radial distribution of magnetic fields are shown in Fig. 2.
We find that the uniformity of radial field distributions is very good. These magnets are fabricated by
Sumitomo Heavy Industry. In addition, steering magnets , power supplies for the magnets, vacuum systemand chambers for beam-monitoring devices were alsofabricated. The construction of the first section was
finished within the last fiscal year and we will proceedwith the construction of the remaining section.

Table 1. Specifications of dipole magnets.
Type

DM90

Deflection angle (degree)
Curvature radius (m)Maximum field (T)Pole gap (rom)Pole face rotation (degree)
Size of hollow conductor (mm)

90
0.8
1.5
60
013.5-$8

Total number of coil windings
Maximum excitation current (A)Maximum voltage (V)

280
300
47.7

25/25

Table 2. Specifications of quadrupole magnets.
T~pe

Q170

Aperture (rom)Length (rom)
Effective length (mm)Maximum field gradient (Tim)
Size of hollow conductor (rom)

70
170
200
15.5
06-$3

Number of coil windings (lpole)
Maximum excitation current (A)Maximum volta8e (V)

30
260
17.3

1.001 l--;:::======:::;:~----'

1.000~o 0.999

0.998

: ~1

___

1_18____~~ ~.

0.997 L-7......
60--7..J..80-~8~00---~82~0-""""":"84~0~

Fig. 1. Layout of AVF-PA beam line. A vertical view ofthe skew beam line is shown in the rectangular box.
Center for274

uclear Study, University of Tokyo

R(mm)Fig. 2. Cross-sectional view of the dipole magnet and theradial distributions of magnetic fields are shown.

RIKEN Accel. Prog. Rep. 35 (2002)

Beam transport line from AVF to CRIB-FO target
S. Watanabe,* T. Teranishi,* Y. Yanagisawa, s. Michimasa,* M. Notani,* K. Ue,* s. Kubono,* Y. Ohshiro,*
N. Yamazaki,* T. Katayama, and M. Kase
A new beam line has been constructed in the experimental hall 7, called E7, of the RIKEN Accelerator
Research Facility (RARF) for a low- energy secondary
beam separator, the CRIB.l) The newly constructedbeam line is downstream of the vertical bending magnet, called DMC1, as shown in Fig. 1. The designed
beam optics and constructed system are summarized
in the literature. 2 ,3) An overview of the E7 beam linefrom the AVF cyclotron to the CRIB target is presented in this report.
Table 1 shows a list of magnets in the E7 beam line.
Components are listed in order along the beam linefrom the AVF cyclotron to the CRIB target chamber, called FO. In Table 1, the magnet name refers
to the abbreviation listed in the control table of the
K70-AVF cyclotron. Steering magnets are located ateach straight section. The Q-doublet, called QDCll,

Fig. 1. The E7 beam line. The K70-AVF cyclotron beam istransmitted from the upper floor and is bent by DM7C
in the E7. The quartet-Q magnets and CRIB-FO target
are seen in front sight. Vacuum isolation between theE7 beam line and the K70-AVF cyclotron can be realized with a rotary shutter RC-CE7 with the gate valvefunction.
Center for Nuclear Study, Graduate School of Science, University of Tokyo

Table 1. List of magnets in the AVF-E7 BT.
Mag. Name
QTCOlaQTC01b
QTC01cQTC02aQTC02bDMC1
QDClla*l
QDCllb*l
DM7C*2
QT7A1aQT7A1b
QT7A1cQT7A1dGap or Bore
70¢
70¢
70¢
70¢
70¢
60h
70¢
70¢
60h
90¢
90¢
90¢
90¢

EFB
0.25m
0.45m
0.25m
0.20m
0.20m
1.256 m0.20m
0.20m
1.256 m
0.23m
0.23m
0.23m
0.23m

*1 Rotation angle is set at +10 degrees (right)
when the CRIB beam line is selected.
*2 Rotation angle is fixed at +10 degrees in x-y
coordinates when the CRIB beam line is selected. The measured EFB of a steering magnet equipped in the E7 beam line is 0.18 m.

in the vertical beam line is equipped with a rotatablesupporting frame. The vertical bending magnet, called
DM7C, is also equipped with a rotatable supporting
frame. The DM7C utilizes the different beam courses
in the E7. The DM7C has been rotated by 10 degrees in the clockwise direction to guide the beam to
the CRIB . The upstream QDC11 can generate a skew
component in order to compensate for a beam rotation down stream of the DM7C. A quartet-Q (QT7 A)
is located in the E7 to focus the pin-spot beam on the
CRIB-FO target .
The magnet power supplies for the E7 beam line aresummarized in Table 2, and the newly constructed ones
are indicated. All of the power supplies are controlled
by the RARF computer control system. The interface
system named DIM is used to communicate with the
upstream control system. The interlock system is also
monitored by the same control system.
Four sets of beam profile monitors are equipped in
the E7 beam line. The first, called PF8, and the third,
called PF9, of the beam profile monitors using 3-wiresensors are located at the exit of the vertical bending magnet (DM7C) and immediately in front of the
CRIB-FO target, respectively. The second, a hybridbeam profile monitor named HBPFM, has been installed. 4 ) The HBPFM provide the both sensors, the3-wire tungsten sensor and a fluorescence screen. The
fluorescence screen is made of AI 2 0 3 +Cr. It is locateddownstream of the quartet-quadrupole magnets named275

Table 2. List of magnet power supplies.
Mag. Name
QTCOlaQTCOlb
QTCOlcQTC02aQTC02bDMC1
QDClla*1
QDCllb*1
DM7C
QT7A1a*2
QT7A1b*2
QT7A1c*2
QT7 A1d *2

V p (V coil)
15V
22V
15V
16V
16V
76V
18 (16.4) V
18 (16.4) V
76V
40 (29.32) V
30 (21.99) V
30 (21.99) V
40 (29.32) V

Current
150A
150A
150A
260A
260A
300A
400A
400A
300A
40A
30A
30A
40A

*1 Moved from the Tanashi SF-Cyclotron faci lity.
*2 Newly constructed by IDX Corp. Ltd.

QT7 A as shown in Fig. 2. The fourth , a fluorescencescreen coated with ZnS, is installed in the CRIB-FO
target chamber.
The Faraday cup monitor, called COl , is equipped
at the exit of AVF. Identical monitors , called 7AO
and 7AI, are equipped downstream of the DM7C , respectively. The CRIB-FO target chamber provides the
Faraday cup monitor behind the nuclear target.
A test of the E7 beam line has been carried using
the primary beam of 7 MeV /nucleon 14N5+. The testof the beam line aims to confirm the beam sizes, transmission efficiency, and the center of the beam line. In
this beam test, acquired beam properties were confirmed by comparing the findings with the calculated
beam optics, taking into account the assumed emittances and momentum spread at the exit of the AVF
cyclotron. The twice parameters f3x, ax, f3z, a z , 'Tlx,
and full-momentum spread are assumed 4.56 m , -2.97,
0.985 m, -2.98 , 0.859 m , and 0.1 %, respectively. The
measured beam properties agree well with the calculated results. The obtained transmission efficiency is
88% at the CRIB-FO target .
A beam alignment system in the E7 horizontal beamline has been constructed to align the beam center
along the centerline of the FO target. The details of
the beam alignment system using the HBPFM are de-276

Fig. 2. The HBPFM located downstream of the QT7 Ald.
The fluorescence screen is monitored by a TV camera
through the glass window located at the opposite sideof the HBPFM.

scribed in the elsewhere.5)
The AVF -E7 beam transport line was constructed
to guide the beam to the CRIB. A first beam of
7 MeV /nucleon 14N5+ was transported to the CRIBFO target on Nov. 25, 2000. The constructed beamtransport line has worked as designed.
The authors express their thanks to the RIKEN accelerator group for their support in constructing thedeveloped system as well as in the operation of the
AVF cyclotron and beam transport line.
References
1) T. Teranishi et al.: CNS-REP-39, Oct. (2001).
2) S. Watanabe et al.: CNS Ann. Rep. 1999, 44.
3) S. Watanabe et al.: CNS Ann . Rep. 2000, 9.
4) S. Watanabe: CNS Ann. Rep. 2000, 58.
5) S. Watanabe et al.: CNS Ann . Rep. 2000 , 60.

RIKEN Accel. Prog. Rep. 35 (2002)

Conceptual design of the fixed-frequency ring cyclotron
T. Mitsumoto,* A. Goto, N. Sakamoto, K. Uno,* and Y. Yano
A fixed-frequency ring cyclotron (ERC) is proposed
for the RIKEN RI Beam Factory Project. 1) The ERC isused between the Riken Ring Cyclotron (RRC) and theIntermediate-stage ring cyclotron (IRC). 2) The ERC
will enable us to obtain a 350 MeV/nucleon uranium
beam at the exit of the Superconducting Ring Cyclotron (SRC).
The main parameters of the iRe are listed in Table 1. The iRC will be installed in an experimentalroom of the existing Riken Accelerator Research Facility (RARF).3) The size of the ERC is restricted by thesize of the room. One of the more severe conditions forthe sector magnet is the limited height. The position of
the beam line is 1. 7 m above the floor level. Thus, theheight of the sector magnet must be less than 3.4 m.
This height is about 65% of the height of the RRC,
which is almost the same size as the ERC in terms of
the k-value of 540. Even under this condition, the distance between the top of the magnet and the bottomof the crane gutter of the room is 1.5 m. We should
pay attention to this distance when the magnets will
be assembled in the room.
The ERC is a fixed-frequency cyclotron, so the injection and extraction energies are fixed. The major ions
to be accelerated are 238U72+ and 136Xe48+. Table 2
shows the field parameters for the ions.
Because of the different field levels among the ions,a conventional structure of the sector magnet does notrealize isochronous conditions for all ions in spite ofthere being the same energy conditions. Figure 1 shows

Table 1. Main parameters of the fRe.
K-b value
N umber of sectors
Harmonics
Mean radiusInjection energy
Extraction energy
Velocity gain factor
Number of cavities
RF frequency

510 MeV48Injection
1.58m
extraction
3.16 m
10.95 MeV /nucleon
46 .28 MeV /nucleon
2.0
236.66 MHzb048

0. 2 - -- - -..........-_"T"'''T''''''T'"'''T'"..,....,..-r-r-r''"''"'1
0.1

-0.1

238tl2+

1.5

238U72+

136Xe48+

16 0 8+

0.303

0.353

0.5

0.855T
0.887T

Sumitomo Heavy Industries, Ltd.

3.0

Fig. 1. Isochronism of three ions for a conventional sector
magnets.

the isochronism of each of the ions for the conventional
sector magnet. The pole shape of the magnet is optimized for 13 6Xe 48 +. Errors in the isochronism of
238U72+ ions reach 0.5%. The errors originate fromiron saturation of the magnet.
In order to compensate the errors, it is common to
use trimcoils. This method is straightforward and flexible. However, by adopting trimcoils, the structure of
the magnet becomes very complicated and numbers of
power supplies are required. Another method of compensation is pole shape optimization. This method
use that the lack of the iron inside the pole affects thefield distribution at a high field level. Figure 2 'showsa schematic of the method. At the side of the pole,an intentional lack was created. This method can re.
C. ns 238U72+
d uce t h e error .
III .ISOC h rOlllsm
lor b 0 th 10
and 136Xe 48 + to less than 0.05%.

Yoke

intentional lack

Pole

LO

C\I

0.998 T
1.035 T

2.5
Mean radius (m)Table 2. Field parameters for the ions.

q/A
Mean field
Injection
Extraction

2.0

Beam

0.604T
0.626T
Fig. 2. Schematic cross-sectional view of the pole.

277

Figure 3 shows the conceptual plane view of the sector magnet. The sector magnets, resonators, injectionand extraction devices are shown. The main components of the cyclotron are installed in an area 9.6 m
square. The total weight of the cyclotron is approximately 1300 tons .
Table 3 shows the main parameters of the sector

9600

Table 3. Main parameters of the sector magnets .
Pole gap
Sector angle
Total height
WeightMaximum magnetic field
Main coil
Maximum current
Maximum excitation current
Power consumption

50mm
58.4 degree
3.34m
300 toni sector
1.65T
600A
84 kA/sector

50 k W I sector

magnets. The sector angle is chosen to be as large as
possible such that the sector field becomes low. Otherwise the design of the injection devices become moredifficult. Even in the present design, the magnetic fieldin the MIC is 2.1 Tesla, including the sector field of 1.6
Tesla. The MIC for the fRC should create 0.5 Tesla at
maximum, which is twice the value of the MIC for the
IRC.
Further optimization of the design of the fRC is being carried out. The RF system of the fRC is being
studied in order to obtain high efficiency in the total
system of the RI beam factory, i.e., its phase stability,
the requirement of bunchers, the possibility of flat top
resonators , and so on.
References

Fig. 3. Conceptual plan view of the fRC.

2781) Y. Yano et al.: RIKEN Accel. Prog. Rep. 3 4, 301(2001) .
2) T. Mitsumoto et al.: RIKEN Accel. Prog. Rep. 34, 331(2001).
3) http: //www .rarf.riken.go.jp/

RIKEN Accel. Prog. Rep. 35 (2002)

Magnetic field measurement of the IRe sector magnets
J. Ohnishi, T. Mitsumoto,* A. Goto, and Y. Yano
All elements of the intermediate-stage ring cyclotron(IRC) were completed at Niihama factory, Sumitomo
Heavy Industries, Ltd., in spring 2001. Some of theirmagnetic elements such as four sector magnets were assembled at the factory and excitation tests and magnetic measurements were carried out. Following themeasurement of the E-sector magnet performed in2000 , the magnetic field mapping measurements of all
four sector magnets (E, N, W , and S sectors) were performed. These sector magnets were arranged as shownin Fig. 1. Due to space limitation in the factory building, two sets of the sector magnets were separated,unlike their actual arrangement. The measuring apparatus of the magnetic field mapping were designed andfabricated exclusively for the IRC sector magnets. I)
The mapping measurements were performed.at magnetic field levels of 0.6, 1.0, 1.4,1.6, 1.7, 1.8 and 1.9T.
The number of measurement points is about 34000
in the region of 180 degrees for two sector magnets,
and the measurements took about 15 hours including
3 hours for setting the magnetic field. Figure 2 shows
the magnetic field distributions along the sector centerline of the four sector magnets at 1.6 T. The difference of the magnetic field among the four sectors
was largest at this magnetic field level. The differenceis about 70 gauss at a maximum and the differenceof the field slope in the radial direction is about 20
gauss. These differences will be corrected by adjusting
the main and the trim coil currents among the sector
magnets in order to reduce the first-harmonic field.
Each sector magnet has 20 pairs of the trim coils
wound by one turn on the upper and the lower polefaces. Each pair of trim coils was excited with an individual power supply and the magnetic fields were
measured. An example of the magnetic field distributions produced by the trim coils is shown in Fig. 3.

D

D

D

D
3.84m

r

Dmm

Fig. 1. Arrangement of the IRe sector magnets whenthe magnetic field measurements were carried out at
Niihama factory.
Sumitomo Heavy Indust ries, Ltd.

1605 , - , . - - - - - - , - - - - - - , - - - - . , . - - - - . , . - - ,

1600

1595
>-

-5

1590

CD

.. .. ---e-- E-sector

1585---b-- N-secot_ _ W-sector

1580

..

!...... ~ $-0"", ············r·.............................................

1575 ' - - - ' - - - - - - ' - - - - - - - ' - - - - - - ' - - - - - - ' - - - '
2500
3500
4000
4500
3000

R(nm)

Fig. 2. Difference of the magnetic field distributions amongfour sector magnets at the main coil current of 290 A.

'E
'a;'

1-...:.. ........... ....... ..... ; ................... ....

!. I.f..I..f.·-/-·I: ····f··J··r· r·r·~ "U" .. / ..... '1".

0

-2'i"JIlltMIIIITf................. .

2500

3000

3500

4000

4500

R(nm)

Fig. 3. Trim coil field distributions along the sector centerline at the base field of 1.6 T. The current values are- 200 A for the inner 8 coils and 250 A for the outer 12
coils, which are half of the nominal currents. The minus
sign of the current indicates that the current directionis the reverse of that of the main coil.

Since these magnetic field distributions depend on themagnetic field strength, they were measured at fivemagnetic field levels. By using these magnetic field
data, the current values of the main and the trim coils
can be calculated to generate the isochronous magnetic
fields required for beam acceleration. 2 )Poles of the sector magnets consist of two pieces ofpure iron plate with a thickness of 26 cm. When the
beam chambers are evacuated, atmospheric pressure
is applied to one piece of the iron plate and deforms
it. The influence of the deformation was measured.
Seven Hall probes were placed in a pipe inserted along
the sector centerline and the beam chamber was evacuated. Figure 4 shows the change of the magnetic field

279

0.6

---:-

0.2
~

.5-

0. 0

:

.,~;~?T?~;r

0.4

~\

..,I,.•...'.1. '.................... :,. • • ••••••••••••••••••' • :\.,"-\ •••••••• ••••••••....... ~1/-0.2. . . ~. . ;ir." . . . ~ . . . . . . . . . . . . . . . . . . . . .L:!,. . . . . .

-0.4.................. - e - E-sector (1. 9T) .. ..... .. .... ... ... !............\ .... .

al
~

:}'"

:

E-sector (1. OT)j__ - S-sector (1. 9T). . . ... . . • .. S-sector (1. OT)
-&-

'/

-0.6

.

··T·· .

\

:
\
.
..
......... ..... , ..... ... ........... .

-0.8
2500

3000

3500

4000

4500

R(IIII1)

Fig. 4. Change of the magnetic fields along the sector centerline when the beam chamber was evacuated.

before and after evacuation. The maximum change isabout ±6 gauss, which corresponds to the deformationof about 35 j.lm. This effect is not negligibly small and280

must be corrected in the calculation to generate theisochronous field.
The MICI and the MDCl, the magnetic elements
for beam injection and extraction,3) were installed into
the W-sector and the S-sector, respectively, and theirmagnetic fields were measured. In the future, we plan
to make the magnetic field measurements of all the injection and extraction elements (MIC2, MDC2, BMl,
EBMl, and EBM2) and obtain the magnetic field datanecessary for cyclotron operation. Thus, the magnetic
field measurements will be performed for a short period
after assembling the IRe at RIKEN.
References
1) J. Ohnishi et al.: RIKEN Accel. Prog. Rep. 34, 333(2001).
2) J. Ohnishi et al.: Proc. 16th Int. Conf. Cyclotrons andTheir Applications (2001), p. 351.
3) T. Mitsumoto et al.: RIKEN Accel. Prog. Rep. 33 , 208(2000) ·RIKEN Accel. Prog. Rep. 35 (2002)

Electric field measurement of the acceleration resonator for theIntermediate-stage Ring Cyclotron (IRC)
N. Sakamoto, O. Kamigaito, T. Mitsumoto, Y. Miyazawa, S. Kohara, H. Okuno, A. Goto, and Y. Yano
We carried out an electric field measurement of thesingle-gap acceleration resonator for the IRe whose
operational frequency range is 18- 40.5 MHz.l) The
strength of the electric field was measured by a perturbation method. A schematic view of the setup of
the measurement is shown in Fig. 1. The phase variation of the signal from pickup A was measured moving
a perturbator from Xl to X17 along the beam orbit
step-by-step (Fig. 2). The measured C1¢ was less than
45 degrees. The perturbator used was a spherical one
made of Ti 0 3 (E* = 31) with a diameter of 30 mm. The
radial distribution of gap voltage V(R) was obtained
from the phase variation as

The parallel shunt resistance (Rs) were also evaluatedasRs(E* + 2) . 36000
3(E*-I)~V=

i=l~ V: Volume of the perturbator [m 3 ]fo: Resonant frequency [Hz],and shown in Fig. 4 with unloaded Q values.

The

1.0

17

V(Rn) ex(fl: jtan C1¢(xd [arb.units]

i=l
Rn: Radial position (n = 1- 10) ,

Zl

0.9

'2
::>

.D

~

for the frequencies of 18, 28 , 36, and 41 MHz (Fig. 3).

0 .8

Q)

t>IJ

!l
'0
::-

p..

Network Analyzer

I~
I

1

0.7

III

0

8753E
0.6

2

son
Raverage

Feeder
IRC Resonator[mm]

Fig. 3. Voltage distributions as a function of averaged radius of the beam orbit for (1) 18 MHz, (2) 28 MHz, (3)36 MHz, and (4) 41 MHz. The gap voltage is maximum
at the extraction radius.

Fig. 1. Schematic view of an electric field measurement by
a perturbation method.

30000

3

20000

2

~

::0

"l:l

Pickup A

~
~

C/J

Rs

S2
2

;:l

0'

10000

PickupBo~~~~~~~~~~~~~~~o

15

20

30
25
35
Frequency [MHz]40

IRC ResonatorFig. 2. Setup of the phase-shift measurement.

Fig. 4. Rs and unloaded Q-values as a function of frequency.

281

measured Rs values are as large as about 75% of thecalculated values using t he MAFIA code. Q-values
are also 74- 79% of the calculated ones. At the frequency of the 38 MHz, 400 MeV /nucleon acceleration,
the required peak voltage of 600 kV is expected to beobtained with 100 kW rf power while the maximum

282

output power of the final amplifier is 150 kW.
References
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.

RIKEN Accel. Prog. Rep. 35 (2002)

Design study on beam transport system from IRe to RARF
N. Fukunishi, M. Kase, and Y. Yano
In the RIKEN RI Beam Factory (RIBF) project,
a two-stage acceleration scheme and simultaneous
utilization of heavy-ion beams in both the existing
RIKEN Accelerator Research Facility (RARF) and the
RIBF facility were proposed. 1) A cascade of two cyclotrons, a K = 9S0-Me V Intermediate-Stage Ring Cyclotron (IRC) and a K = 2500-MeV Superconducting
Ring Cyclotron (SRC) were chosen to be the postaccelerators of the existing RIKEN Ring Cyclotron(RRC). A part of the IRC beam will be transferredback to the existing facility. Recently, insertion of a
K = 5l0-MeV fixed rf-frequency Ring Cyclotron (fRC)
between RRC and IRC was proposed. 2 ) The new cyclotron cascade is designed to accelerate a uranium
beam up to 350 MeV/nucleon in order to produce RI
beams efficiently via the projectile-fission reaction. In
the new scheme, IRC is capable of producing heavy-ion
beams with an energy of more than 100 MeV /nucleon
over the entire range of atomic masses. The beams
accelerated by IRC have sufficient energy to produce
RI beams and the ranges in materials for IRC beams
are shorter than those for SRC beams. Hence, uniqueexperiments with IRC beams in RARF have been proposed. One example is to use RI beams as a probe toinvestigate the properties of materials.
In simultaneous utilization of both the existing facility and the RIBF, it is important to determine how
to share an IRC beam. Many users of RARF seriously
discussed this problem and two schemes were proposed.
One is the conventional time-sharing method in whicha pulsing magnet is used. This is a very simple method
but DC beams are not obtainable. The other is to use acharge stripper. A part of an IRC beam will be chargestripped and the charge-stripped beam will be transferred back to the existing facility. By this method,
DC beams are obtainable but a sizeable beam loss ispredicted for ions with Z > 60. Moreover, a complex
system consisting of one analyzing magnet and two
additional bending magnets is necessary. The analyzing magnet will separate the beam into two parts by
utilizing the difference in magnetic rigidity. The additional two bending magnets are necessary to matchthe trajectories of various ions to the beam line from
IRC to RARF. The time-sharing method was finallyadopted to avoid the use of a complex system. The
maximum magnetic rigidity was chosen to be 4.2 Tm.
It is based on the estimation 3 ) of the magnetic rigidityof the beams with Z < SO. For heavier ions, separation of RI beams is difficult with the existing RIKEN
Pro jectile-Fragment Separator (RIPS) .
The new beam transport system from IRC to RARF
was designed to perform RI-beam experiments using
the RIPS. The beam transport system is illustrated inFig. 1. The beams accelerated by IRC will be doubly
achromatic at PI shown in Fig. 1. The section from PI
to P2 will shift the beams upwards by 3 meters. Doubly achromatic transformation will occur for the section from P2 to P3. The quadrupole quartet between
P3 and P4 is introduced to obtain an erect ellipse at
P4. The section from P4 to P5 is doubly achromaticand telescopic. The beam will be expanded once andstrongly focused by the quadrupole doublet placed below the RIPS target.
All magnets and power supplies will be newly fabricated except for the power supply of the pulsing magnet. We plan to use the existing power supply developed by Kouzu et al. 4 ) for the pulsing magnet, which
was designed by K usaka et al. 5) The specifications of
the dipole magnets are summarized in Table 1. The
newly designed dipole magnets will be compact and aredesigned to have wide regions where magnetic fields are

to Big-RIPS------------------------~ "'''o'- - - -1'----------,

Fig. 1. The beam line from IRe to RARF is shown in bold.
The PM indicates the pulsing magnet introduced for thetime-sharing of beams.

283

Table l. Parameters of dipole magnets.
T~eeDeflection angle (degree)
Curvature radius (m)Maximum field (T)Pole gap (mm)Pole face rotation (degree)
Size of hollow conductor (mm)DM90

Total number of coil windings
Maximum excitation current (A)Maximum voltage (V)Number of ma~nets

uniform. The quadrupole magnets will have the same
shape as those developed for the beam transport system of the RIBF. 6) Construction of the magnets andpower supplies has already started and will be finishedin March 2002.
References
1) Y . Yano et al.: Proc. 1997 Particle Accelerator Conf.,
Vol. 1, Vancouver, Canada (1997), p. 930.
2) Y. Yano et al.: Proc. 16th Int . Conf. on Cyclotrons and

284

DM72

DM45

DM25

45
25
90
72.5
2.7
2.7
2.7
2.7
1.56
1.56
1.56
1.56
60
60
60
60
25/25
25/25
15115
12.5/12.5
013.5-$8 013 .5-$8 013.5-$8 013.5-$8
288
330
133.7
2

288
330
108.2
2

288
330
70.4
2

288
330
45.1
2

Their Applications, 2001-5, East Lansing, USA (2001),
p. 16l.
3) H. Ueno et al.: private communication.
4) H. Kouzu et al.: RIKEN Accel. Prog. Rep. 34, 355(2001) .
5) K. Kusaka et al.: RIKEN Accel. Prog. Rep. 35, 297(2002).
6) N. Fukunishi et al.: RIKEN Accel. Prog. Rep. 34 , 329(2001) .

RIKEN Accel. Prog. Rep. 35 (2002)

Status of the SRC for the RIKEN RI Beam Factory
A. Goto , H. Okuno, J. Ohnishi, N. Fukunishi, S. Fujishima,*1 T. Tominaka,*2 K. Ikegami, N. Sakamoto,Y. Miyazawa, T. Mitsumoto,*3 O. Kamigaito, S. Yokouchi , H. Akiyoshi, T. Morikawa, M. Kase,and Y. Yano
In this report, we give a general description of thestatus of construction of the Superconducting Ring Cyclotron (SRC); detailed reports on the main components are given elsewhere in this Progress Report.
One of the tasks on which we have concentrated ourefforts for the sector magnet is a detailed structural
analysis of the superconducting main and trim coil vessels, pole, yoke, cryostat vacuum chamber and beamchamber, etc. Detailed design explorations examining how to electrically insulate and fix the indirectly
cooled superconducting trim coils in their coil vessel
were also carried out. To confirm the design, the heattransfer coefficient and strength and voltage resistanceof the epoxy resin that is to be used for insulation were
measured. Detailed quench analyses to protect the superconducting main and trim coils have been carriedout. 1) At present the specifications of the power supplies for the superconducting main and trim coils andthe normal-conducting trim coils are being finalized.
The design of the cryogenic cooling system and arrangement of its components such as the refrigerator
and the compressors in their respective rooms is also
being finalized. Both Hitachi and Mitsubishi are fabricating the sector magnets. The first vessel of the main
coil before winding has already been machined at eachfactory, and the winding is scheduled to start in midDecember, 2001. Details of the design of the sector
magnet are given in Ref. 2.
The superconducting bending magnet (SBM), whichis uniquely superconducting among the injection andextraction elements, is halfway to its completion;3)
winding of the superconducting coils around the pole
has been completed. Fundamental and mechanical designs of the other injection and extraction magnetic
elements, which are normal-conducting and similar to
those of the RIKEN Ring Cyclotron (RRC) and theIntermediate-stage Ring Cyclotron (IRC), are being
made. 4 ) Design mechanisms for installing and fixing
the magnetic channels and electrostatic channels in thecomplicated structure of the beam chambers and thevalley chamber, respectively, have been finalized.
The mechanical design of the main rf resonators ,which are of a similar type to those of the IRC, has already been completed;5) that of the flat-top resonatoris currently being made. Amplifiers are designed to be
set immediately outside the magnetic shield of the sector magnet on the same level as the resonators. As of
November 2001 , the outer boxes of two out of the four
*1

Ishikawajima-Harima Heavy Industries Co., Ltd.

*2 Hitachi , Ltd.
*3

Sumitomo Heavy Industries, Ltd.

main resonators have been fabricated. The amplifiersystems for the four main resonators have already been
completed.
The fundamental design of the vacuum system has
been finalized as reported in Ref. 6. The mechanicaldesign of the rf resonators and valley chambers withrespect to how and where the cryopumps should be set
has been made. The effect of oscillation of a cryopumpon the rf characteristics is being investigated.
Beam diagnostic devices are designed to be similar
to those of the IRe. They consist mainly of a main differential radial probe, two differential radial probes inthe extraction region and twenty pairs of phase probes.
The main differential radial probe, which is too long

Fig. 1. Photograph of the SRC vault along with the IRC
vault in April 2001. The bases for the sector magnetsof both cyclotrons can be seen.

Fig. 2. Photograph of the SRC vault in April 2001. The
bases for the sector magnets can be clearly seen.

285

to be set inside the magnetic shield, has been designed
so as to penetrate the side door of the magnetic shield.
The design of the plumbing of the helium transfer tubes and emergency He-discharge line has almost
been finalized , while that of the water cooling pipes
for the cyclotron itself and its power supplies is being
made.
Construction of the building including the SRC vault
is proceeding according to schedule. As for the SRC
vault , cranes are scheduled to be installed at the end of
2001 and ceiling concrete slabs to be set at the beginning of 2002. Figure 1 shows the SRC vault along with
the IRC vault, and Fig. 2 shows a close-up of the SRC
vault; both photographs were taken in April 2001.

286

References
1) T. Tominaka et al.: Proc. 17th Int. Conf. on Magnet
Technology, Geneve, 2001-9, to be published.
2) A. Goto et al.: Proc. 16th Int. Conf. on Cyclotrons andTheir Applications, East Lansing, 2001-5 (2001), p. 319.
3) H. Okuno et al.: Proc. 17th Int. Conf. on Magnet Technology, Geneve, 2001-9, to be published.
4) S. Fujishima et al.: Proc. 17th Int. Conf. on Magnet
Technology, Geneve, 2001-9, to be published.
5) N. Sakamoto et al.: Proc. 16th Int . Conf. on Cyclotrons
and Their Applications, East Lansing, 2001-5 (2001),
p.306.
6) K. Sugii et al.: RIKEN Accel Prog. Rep. 33, 226 (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Effect of Vr + V z == 2 resonance In the SRC
T. Mitsumoto,* A. Goto, N. Fukunishi, and Y. Yano
The SRC for the RIKEN RI-Beam factory project 1)
is designed to accelerate various kinds of heavy ions
up to 400 MeV/nucleon. In the case of an ion with an
extraction energy of 400 MeV /nucleon and A/q = 2,
betatron frequencies lie very near a resonance line of
Vr + Vz = 2. In this report, the effect of the resonanceis studied.
Resonances in coupled oscillations in a cyclotron
were studied by Joho.2) A Hamiltonian and the equations of motion in (x, y) cartesian coordinate are:

For the SRC, we focus on the Vr + Vz = 2 resonance,
i.e. , n = m = 1, p = 2. The equations of motion (1),(2) and (5) become:p~ =i Cx1vJ ~,HI = apxnym cosp(() - ()o),

a 2 = a2·x" + v;x = _napxn-lym cosp(() - ()o),
y" + v;y = _mapxnym-I cos p( () - ()o).
The resonance condition is satisfied if

nvx ± mvy - p ~ O.
In this report, for simplicity, we do not consider theeffect of the radius of the cyclotron.
Employing a canonical transformation and neglecting the fast oscillating part, the final HamiltonianK(px, <p) and the equations of motion are given by:m

K = -fi,qpx - fi,pI pJ cos <P ,J x - J y = -Jo
py = Px - 1

(1)

(2)

where

Hoy
mHox
J o = J y =t= mJx = - - ± - - = const,
Vx
nvx
_ mix
mJx
mvx 2
Px = To = n lJol = 2nlJo xo,
_ Jy
Vy 2
py = 1101 = 2I J oI YO ,!:lv
q=-fi, ,!:lv =- nvx ± mvy - p,

(3)

(4)

(5)

In Eqs. (3) and (4), Xo and Yo represent the amplitudes
of betatron oscillation.
Sumitomo Heavy Industries, Ltd.

( J o < 0 ),

(9)
(10)

( Px 2:: 1 ).

1.

1

1.

1

Px = -fi,p];(Px -1)2 sin<P leqfi,p];(px -1)2 < fi,Px,p~
2 dxo- = - - <fi,.
(11)
Px
Xo d()
Thus, the growth rate of the radial amplitude of theoscillation Xo per turn (27r) is:

27r dxo- - <7rfi,.
Xo d()ifi, = ma; (_n_) ~I!!! IJol m+; - 2 .
2mvx(2vy) 2

(8)

Under the condition t hat the axial oscillation is muchsmaller than the radial oscillation, Px is nearly l.
We can roughly estimate the maximum growth rate
analytically from the equations of motion (6) and (3).
Iand

~ ( np;-;2 pJ ± npJ p;:;2) cos <P,

cos 1',

We assume that x represents radial motion and yrepresents axial motion. Under normal acceleration
conditions in a cyclotron, radial motion should havesome amplitude of the oscillation around an equilibrium orbit. Axial motion, however, idally has no oscillation. We can apply the dominating x-oscillation
condition of the sum-resonance defined by Joho.

and<p' = -fi,q -c:: 1) ~]

where
K=

p~ = -fi,pJ pJ sin <P,[(PxP: 1)~ +

(6)

(7)

Ho = 2(P~ + v;X2 + p; + v~y2),

n

1

I
fi,
<P = -qfi, - 2

H=Ho+Hl ,11-fi,pl (Px - 1) 2 sin <P,(12)

Using Eqs. (3), (4) and (10) , we can determine theaxial amplitude of oscillation Yo from Xo2
Vx 2 21J o
Yo = - Xo - - - .
Vy
Vy
l

(13)

Using a numerical integration method, we can obtain precise information from the equation of motion.
Figure 1 shows results obtained by numerical integration of the equations of motion (6) and (7) with theRunge-Kutta algorithm. Consecutive points are plotted at intervals of !:l() = 27r. In this figure, polar coordinates ..;p;; and <P are used, since ..;p;; is proportional .
to the amplitude Xo . If the beam is above the threshold of resonance, i.e., Iql > 1, the equations of motion

287

1.

·1'

K =0.02, q=O.O

K=0.02, q=0.5

K=O.02, q=1.0.. - .....

(

.~

'1

U

K=0.02, q=1.2

1

~

::

··0·:·······..•

.

·2

·1

U

1

~

K=0.02, q=2.0

K=O.005, q=2.0

Fig. 1. Phase-space plots for the Vr + V z = 2 resonance with polar coordinates ffx ~nd <P. Cons~cut.ive
points are plotted at intervals of .t::.() = 27r. If Iql > 1, the equations of motlOn have oscIllatmg
solutions.

have oscillating solutions.
When we consider the construction and installationof the sector magnets of the SRC, the tilt angle aroundazimuthal axis can be easily suppressed by less than
1 mrad. In this case, the value of a2 in Eq. (8) isapproximately 1 x 10- 3 . Thus the maximum of /"i, is
5 X 10- 4 from Eq. (8). Using Eq. (12), we can calculate
turn number n when the radial amplitude increases by
10%.

n = 0.1

dxo> 0.1/7r/"i, ~ 60.
j -27r
Xo de

.,

2.02

N

>
+
>. .

2.00

_.'

~1

2.01

.-

oJ' . , .

vI'.

•..I.•..·••::::::-r::::::::·:::·:····;...;.::-:~ ::~:,.. ::::::::::::::::::::::-::::::::::_.......

1.99
1.98

I.J
:,'"

.

-

.-:'

.~

1.97 L............---................L..............................--'---'-_ _ _""--................___.......
3.5
4.0
4.5
5.0

(14)

We assume that the radial amplitude is 6 mm, whichis the case when large off-centering is introduced foracceleration , and the axial amplitude is almost zero.
The increase of 10% radial amplitude corresponds to
0.6 mm, while the vertical amplitude is calculated to
be 4 mm from Eq. (13).
From these studies, we can estimate the effect of theVr + V z = 2 resonance in the SRC. Figure 2 shows thecalculated Vr + V z value of the SRC for an ion withan extraction energy of 400 MeV /nucleon and A/q =2. One dot corresponds to 4 or 5 turns. If /"i, = 5 X
10- 4 , the resonance band is 1 x 10- 3 (2/"i,). When the
beam crosses the resonance during acceleration, theamplitude of oscillation may increase at the outside of
the bandwidth. Taking the safety factor of 2, we obtaina the bandwidth of 2 x 10- 3 (4/"i,) . Even in this case,the turn number inside the band is about 30. This
number is a half-turn number estimated by Eq. (14).
Therefore, the effect of the resonance is not fatal for
the SRC.
In conclusion, we consider the following points as being effective in minimizing the effect of the resonance.

288

2.03

Mean radius (m)Fig. 2. Dots represent calculated Vr + V z values for the SRC
with an ion of 400 MeV/nucleon and A/q = 2. One dot
corresponds to 4 or 5 turns. The area between the solidlines shows resonance band (21'\,). The area between thedashed lines is the area where the amplitude of oscillation may increase due to the resonance (41'\,).

• First, the coupling factor should be small whichmeans that good alignment is important.
• In the initial condition of the beam, the axial oscillation should be smalL If the axial oscillationis zero, growth of the amplitude due to resonancedoes not appear.
• The radial oscillation of the beam should be small.
In this sense, large off-centering is not favorable
when the effect of the resonance is considered.
References
1) Y. Yano et al.: RIKEN Accel. Prog. Rep. 34, 301(2001).
2) W. Joho: SIN-Report TM-1l-8, Appendix (1970).

RIKEN Accel. Prog. Rep. 35 (2002)

Superconducting bending magnet for the injection systemof the RIKEN SRC
H. Okuno, S. Fujishima,* l T. Tominaka,*2 A. Goto, and Y. Yano
A bending magnet for the beam injection system of
the SRC 1 ,2) should be superconducting since the required fields are about 4 T and the curvature of thecoils is about 1.2 m. The design of the bending magnet was finalized for real production based on successful results of the R&D coils. 3 ) In this paper the final
design will be described , along with the status of thefabrication.
Figure 1 shows a cross section and plan view of thesuperconducting bending magnet (SBM). The two fiat
coils, the iron poles and the yokes generate the required fields. The yoke is divided into two parts: cold
yoke and warm yoke. The cold yoke, which about half
the fiux passes through, is H-type. This configuration
makes the shifting forces and unbalanced forces on thecold mass small, while the weight of the cold mass is
not too large (about 3 ton). C-type is adopted for thewarm yoke because the available space for the warm
yoke in the side of the sector magnet is very narrow.
A warm duct is installed for the ion beams. Iron shims
and water-cooled baffle slits are attached to the duct.
Two-dimensional analysis was carried out to optimize the geometry of the coils, yokes and iron shims.
The results are summarized in Table 1. The overall
current density must be about 150 Ajmm2 to achieve
the required field. The value of current density is selected on the basis of the results of the test coil described in the next section. Magnetic forces on thecold mass were calculated for the mechanical designs.
The geometry of the yokes is optimized so that theshifting forces and unbalanced forces on the cold mass
are minimized.
Three-dimensional field analysis was carried out toFy support

study the maximum fields at the coil end and the effective field lengths. Coupling of the field of the SBM
with fields from the sector magnets is studied usinga model that includes the SBM and two sector magnets. The generated field of the SBM decreases by
5% compared to the stand alone excitation. Shifting
forces on the cold mass are estimated to be less thanabout 4 kN. This force is comparable with but has the
opposite sign to that from the two dimensional analysis. These results indicate that the cold mass is wellshielded from the sector magnet system by the warm
yoke of the SBM.
Rectangular monolithic NbTi wire of 0.8 mm x
2.4 mm in size was adopted so as to be wound with

Table 1. Summary of the magnetic design.
2D analysis
Field(overall current density)
Forces on coil(Horizontal)(Vertical)
Shifting forces on the cold
mass
Unbalanced force(Horizontal)(Vertical)
3D analysis
BL value(overall current density)
Field at plateau
Effective length

4.1 T(155.5 A/mm 2 )731.9kN/m (expansive)
75.9kN/m (repulsive)
4.23kN/m

5kN/mm
6kN/mm
3.47Tm
150A/mm 2
4.0T
1.74m

Fx support

Set-screw Bolt(a)Warm yoke(b)Fig. 1. (a) Plan view and (b) cross-sectional view of the SBM.
*1
*2

Ishikawajima-Harima Heavy Industries Co., Ltd.
Hitachi Ltd.

289

good alignment . The conductor was coated with polyimide of 50 J-Lm in thickness for electrical insulation.
Polyimide was adopted because of its strength against
radiation. The operation point is less than 30% of thecritical current .
Coil winding is one of the key issues in SBM production because the coils of the SBM have negative
curvature, and thus cannot be wound with any tension. The following method was adopted. In the firststep the coil is wound with tension to a shape which
has no negative curvature. The circumference of thecoil should be the same as that of the final shape of the
SBM coil. After winding of a few layers, the layers arepushed to the mandrel to form the coil into its proper
shape. The merit of the method is that the time forwinding can be reduced without a decrease in performance. This method was successfully applied to thereal coil. After completion of the winding, the coil is
im pregnated in the vacuum vessel. F igure 1 shows the
cross section of the coil casing. The radial and verticalpre-compressions required to maintain the coil compression when the magnet is excited are provided by
set-screw bolts and vertical bolts, respectively. This
support structure was successfully applied to the test
coil. Iron, which shrinks less from 300 K to 4.5 K thanstainless steel, will be used for the inner mandrel of thecenter coil to decrease the degradation of the stress ofthe coil. The coil casing is partially covered by seal
covers for He tightness. The two coil casings are attached to the cold yoke.
The cold mass of the SBM is installed in the vacuum
vessel made of structural iron of 20 mm thickness. It
functions as a part of the yoke which makes shifting
forces and unbalanced forces small. The duct for the
beam bore is connected to the vessel at its ends . The

290

Fig. 2. A coil after vacuum impregnation.

cold mass was supported by three types of t hermal
insulating supports from room temperature as shownin Fig. 1. They are designed to support the cold mass
stably against the shifting and unbalanced forces aswell as against large earthquakes (1 g and 0.5 g in thehorizontal and vertical directions, respectively).
The fabrication of the SBM has started . Two coils
are successfully wound and impregnated as shown in
Fig. 2. The difference of the real coil shape from thedesigned one is less than 1 mm, which is acceptable
for maintain the flattness of the field along the trajectory. The fabrication of the SBM will be completed by
NIarch of 2002.
References
1) Y. Yano et al.: Proc. 16th Int. Conf. on Cyclotrons andTheir Applications, Michigan (2001) p. 161.
2) A. Goto et al.: Proc. 16th Int . Conf. on Cyclotrons andTheir Applications, Michigan (2001) p. 319.
3) H. Okuno et al.: Proc. 16th Int. Conf. on Magnet Technology, Tallahassee, USA, 1999-10 (2000), p. 228 .

RIKEN Accel. Prog. Rep. 35 (2002)

Superconducting sector magnet for the RIKEN SRC
H. Okuno, J. Ohnishi, N. Fukunishi, T. Mitsumoto,d S. Fujishima,*2 T. Tominaka,*3
K. Ikegami, Y. Miyazawa, A. Goto, and Y. Yano
In previous reports , the significant changes to thedesign of the sector magnets of the SRC 1 ,2) were described. In this report, we will describe the details of
the design which we are concentrating on finalizing in
2002.
Cross-sectional and plan views of the designed sector magnet are shown in Fig. 1, excluding the magnetic
shields. The sector magnet is 7.2 m long and 6 m high.
The weight is about 800 tons each. The sector angle is
25 deg. The maximum sector field is 3.8 T, which is required to accelerate 350 MeV /nucleon U 88 + ions. The
main components of the sector magnet are: a pair ofsuperconducting main coils, four sets of superconducting trim coils and, their cryostats, thermal insulation
support links, twenty-two pairs of normal conducting
trim coils, warm-poles and a yoke.
The superconductor for the sector magnet has a rectangular shape consisting of a Rutherford-type NbTi
cable located at the center of theconductor and a stabilizer housing. 3) The conductors' cross-sectional area
measures 8 mm by 15 mm. The stabilizer material
is aluminum alloy with 1000 ppm Ni , which gives ahigh 0.2%-yield strength of approximately 60 MPa at

Fz supportI-i----I

Cryostat wall
(upper abd lower)
Main coil_J~e.9i~my~.n_e+_ t-,f'-- ' - - I
Iii 80 K

i
i
i
i
I
I

i
i

Fig. 1. Cross-sectional and plan views of the SRC sector
magnet.
*1*2*3

Sumitomo Heavy Industries, Ltd.
Ishikawajima-Harima Heavy Industries Co., Ltd.
Hitachi , Ltd.

room temperature, keeping the residual resistivity ratio greater than 800. The total length of the conductors for the six sector magnets is 51 km.
For the main coils, 396 (22 x 18) turns are wound,giving the maximum magneto-motive force per sector of 3.96 MA. The maximum current is 5000 A. A
solenoid winding is adopted for the main coil withcooling gaps of 0.8 mm and 1.5 mm horizontally andvertically, respectively. Spacers made of FRP (fiber
reinforced plastic) are placed in both gaps between
the conductors; about 50% of the vertical conductor
surface is exposed to liquid helium, while the horizontal surface is not exposed. The main coil is designed based on Maddock 's partial stabilization criterion. The main coil vessel, made of stainless steel of 50
or 60 mm thick covers the cross section of the main coilblock (208 mm x 284 mm). It was designed to be sufficiently rigid to support the electromagnetic force on
the coil. The horizontal electromagnetic force of about
260 ton/m is exerted on the long section of the vessel
covering the beam area. In order to support this force ,a pair of connecting plates is attached to both sidesof this section. The plate is 1 m in width and 25 mm
in thickness. One of these plates crosses through therectangular hole (1.5 m in width and 160 mm in height)of the warm iron pole.
Two types of trim coils are used to help generate different isochronous fields for various kinds of ions: superconducting trim coils and normal-conducting trim
coils. Superconducting trim coils which consist of four
sets are attached to the main coil vessels and the connecting plates. A double-pancake winding of the same
conductor as that for the main coil is adopted , in which
the coils are indirectly cooled by forcing two-phase helium through tubes engraved on t he coil case made ofaluminum alloy plates of 18 mm thickness . The four
sets of trim coils consist of 2 (layers) x 4 (turns) x 2(blocks), 2 x 5 x 5, 2 x 7 x 2 and 2 x 8 x 2, respectively.
The maximum current is 3,000 A. Twenty-two pairs ofnormal-conducting trim coils are attached to the surface of the beam chamber that is part of the cryostat,as shown in Fig. 1. The maximum current is 600 A.
The side walls of the cryostat are made of stainlesssteel. The upper and lower walls, which constitute partof the yoke, are made of steel. The upper warm pole iswelded to the upper wall, forming a part of the cryostat chamber. The lower pole is welded to the lower
wall in the same way. The side walls and the upperand lower walls are welded to each other. The gap
distance between the connecting plate and the surfaceof the hole of the warm pole is 70 mm. These gaps
are sufficiently wide to incorporate 70 K thermal radi-291

ation shields. The area of the radiation shields is about
85 m 2 . The thickness of the beam chamber wall madeof stainless steel is 45 mm, and the gap of the chamber, to which the injection and extraction elements areplaced, is 90 mm.
The cold mass is supported with a total of 17
thermal-insulation support links. A multicylinder typeof support link is used for the radial support . The multicylinder , made of stainless steel with an outermost diameter of 320 mm and a length of 850 mm , is designed
to sustain the radial shifting force of 90 ton. It is fixed
onto the surface of the back yoke. The vertical support
is achieved with four support links at the inner-radiuspart and four at the outer-radius part. The azimuthal
support is also achieved with four support links at the
inner-radius part and four at the outer-radius part.
The support links are made of titanium-alloy rod andare designed to have a spring constant larger than
140/190 (100/85) kN/mm to sustain the vertical (azimuthal) unbalanced force. The vertical support links
are fixed at the upper and lower yokes. The azimuthal
links are fixed onto the surface of the upper and lower
walls of the cryostat. The entire system of support
links is designed to sustain additional forces due to an
earthquake of 980 cm/s 2 and 490 cm/s 2 in the horizontal and vertical directions, respectively.
The pole is divided into two pieces in order to generate a hole that allows the connecting plate of themain coil vessel to cross through it. These poles, together with the upper and lower walls of the cryostat
chamber, are fixed onto the surface of the upper/lower
yoke with long screws through the yoke, because a total force of 760 ton due to electromagnetic force andatmospheric pressure is exerted on the pair of poles
toward the median plane. The slabs of the upper andlower yokes are stacked in the horizontal direction inorder to keep the deformation due to electromagnetic
forces as small as possible.
In order to protect the superconducting main and

292

Fig. 2. Photograph of machining a main coil vessel.

trim coils, the quench characteristics were simulatedwith respect to current decay, temperature rise, andvoltage development. The simulation shows that the
optimal resistance of the dump resistor should be 0.3 n
and 0.1 n for the main coil and the trim coil, respectively. The temperature of the main coil rises to about
140 K with this dump resistor. The maximum voltage
generated between the main coil and the coil vessel
can be up to half of 1,500 V, by taking the earth at the
middle point of the dump resistor.
The first two vessels of the main coils are being machined as shown in Fig. 2. The winding will start in
mid-Dec. 2001. The fabrication of all of the parts will
be completed at the end of March 2002.
References
1) Y. Yano et al.: Proc. 16th Int. Conf. on Cyclotrons andTheir Applications, East Lansing (2001), p. 161.
2) A. Goto et al.: Proc. 16th Int. Conf. on Cyclotrons andTheir Applications, East Lansing (2001), p. 319.
3) M. Sugimoto et al.: Proc. 2000 Meet. of the Cryogenic
Society of Japan , Tsukuba (2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Design of the extraction bending magnet for the RIKEN SRC
S. Fujishima,*1 H. Okuno, N. Fukunishi, T. Tominaka,*2 A. Goto, and Y. Yano
The RIKEN Superconducting Ring Cyclotron(SRC) 1) is one of the main accelerators for the RIKEN
RI Beam Factory. 2) The basic design of the injectionand extraction systems for the SRC has been completed. 3 )Figure 1 shows a schematic layout of the injectionand extraction elements, and shows the trajectory of
the beam.
The extraction system consists of one electrostatic
deflection channel (EDC), three normal-conducting
magnetic deflection channels (MDC1, MDC2 andMDC3), and one normal-conducting extraction bending magnet (EBM). Maximum magnetic rigidity of theextraction beams is 7.94 Tm.
Table 1 lists the design conditions of EBM. The design magnetic fields of EBM include the margin of 5%.
Figure 2 shows the cross-sectional plan of EBM.
The turn separation at the entrance of EBM is about
350 mm. EBM is placed in the background stray fields
from the sector magnets, and the stray fields rise to theorder of -450 Gauss at the maximum excitation. The
iron of EBM gathers and disturbs the magnetic fieldin the acceleration region of the SRC, thus compensation coils are indispensable to suppress the field disturbance. The required field uniformity in the central
region of EBM is in the order of 10- 3 . Built-in vertical and horizontal steerers are also required to generate additional steering fields of 200 Gauss and 600

y-t-- -- + -x

Fig. 1. Schematic layout of the injection and extraction
elements and trajectory of the beam.
*1*2

Table 1. Design conditions of EBM.
Design magnetic field
Background magnetic field
Bending radius
Bending angle
Arc length
Iron pole gap
Bore of beam pipe

from -1.26 to -2.14 Tfrom +0.005 to -0.045 T
3800mm55.0deg.
3648mm
46mm<t>40mmTable 2. Hollow conductors used in EBM.
Coil IAC
HVFunction
I Size [mm] I Current [A]main coil
13 x 13690
compensation coil
9 x 14-960
horizontal steerer
13 x 13±1000
vertical steerer
6x 6
±640

Gauss, respectively. The spaces on both the up-and
downstream sides of EBM are small, and thus bothend-structures of EBM should be compact.
Table 2 lists the hollow conductors used in EBM.
Coil-A and Coil-C are wound flatly without bending up
at the ends, to shorten the end-parts. Coil-H consistsof one set of bipolar coils. The arc length of Coil-H is
one-half of the arc of EBM, and Coil-H is built into thedownstream side of EBM. Coil-V consists of two setsof independent-current bipolar coils. The arc length ofeach Coil-Vis one-third of the arc of EBM, and each
Coil-V is built into the both up-and downstream sides
of EBM.
The quantity of the iron yoke should be the minimum necessary, because the iron gathers and disturbs
the magnetic field in the acceleration region of the
SRC. Outer-arc side return yoke is necessary to restrain coil-C from decreasing the magnetic field in thecentral region of EBM. The iron poles were tapered
to concentrate magnetic flux into the central region of
EBM, and the shapes of the pole faces were optimized
to maintain good field uniformity for all excitation levels. Figure 3 shows the field uniformity in the central
region. With the bore of ¢40 mm, field uniformity is
about 2 x 10- 3 .
The efficiency of field generation with respect to themagnetomotive force of coil-A is estimated to be 82%.
Total power consumption of coil-A and coil-C is estimated roughly 175 kW at the maximum excitation.
The basic design of the extraction bending magnet
for the SRC has been studied. The detail design is inprogress in consideration of the fabrication process.

Ishikawajima-Harima Heavy Industries Co., Ltd.
Hitachi , Ltd.

293

500

L

130

136

L

~

16

74

~6

260

···...···...··....... ~~···...···...··.......
I···...···...···.........
····...····....····........ ~~//···...···...···...... ~~···...···...·..... ~rtTil/l
f?§ /
T
r
J
~r
···...···...···...... ;/ Iff~~···...···....··....
~~::: ~ ~····....···...····........
~~_+_~HHHHHc

H

It It A ,., A It

C
C
C
C

H

H

HTH

c

II

C
C

c

c

Wall of the valley-<:hamber

C

C
C
C
C
C
C
C
C

C
C
C
C
C
C

c

~I<--

--- ~

~

~

--'k--

c~'~rOO"t"'~,,:~

C~~ ,.J. ~IN
~I

I

I

C
C
C
C

1:::::

~l

"'__.

38 14

c
c
c

,

~~

It It A A A

It It

A A A It It

It~

Last acceleration equilibrium orbft

A A A A A A

A A It It It It A

c
c

:~:

·.

C
C
C

c

..

5~ ~ H H H ~ -I/- ~ +-~I~HH..'!

~ 2.5

it

~

A It It A It It A
A A A A It It A

dr-

- -

f

u~

3.5

if

Fig. 2. Cross-sectional plan of EBM.

0.003

References

0.00251) H. Okuno et al.: Proc. 13th Symp . on Accelerator Science and Technology, Suita (2001) p. 65.
2) Y. Yano et al.: Proc. 13th Symp. on Accelerator Scienceand Technology, Suita (2001), p. 20.
3) S. Fujishima et al.: Proc. 16th Int. Conf. on Cyclotrons
and Their Applications, East Lansing, USA (2001),

0.002

0-

~

0.0015~0.0005

~

'E

,
"'

0.001

.......

/.....

at the Minimum excitation........

0.0

-.-.

---- ~ -.

.E'c -0.0005
:J
"C

Q)

u::

-0.001

p.449.

-0.0015-0.002at the Maximum excitation-0.0025-0.003
-20.0

-16.0

-12.0

-8.0

-4.0

0.0

6.0

10.0

14.0

Horizontal position [mm)Fig. 3. Field uniformity in the central region.

294

18.0

RIKEN Accel. Prog. Rep. 35 (2002)

Quench protection of RIKEN Superconducting Ring Cyclotron
T. Tominaka,* J. Ohnishi , H. Okuno, N . Fukunishi, A. Goto, and Y. Yano
For the design of the protection system of the superconducting main coils of the RIKEN Superconducting
Ring Cyclotron (SRC),l) the quench characteristics arecalculated with respect to various parameters, suchas current decay, temperature rise, and voltage development , using the computer program "QUENCHM" .2) The AC losses and pressure rise pertaining to
the quench are also estimated .
The principal circuit diagram for the superconducting main coils of all six sectors of the SRC is shown in
Fig. 1. There are subsidiary power supplies with dump
resistors for use in the adjustment of the magnetic fieldof each sector. As the effects of the subsidiary power
supplies and the dump resistors are minor, the quench
analysis is performed for the simplified principal circuit
diagram shown in Fig. 1.
The calculated results for two cases for the dump
resistor, Rm of 0.3 and 0.4 n with different quench velocities and different switching off times of the power
supply, are listed in Table 1. The quench velocityof 4.1 m/ s is estimated under the adiabatic condition. In order to confirm the calculations with program "QUENCH-M ," the calculated results for the low
quench velocity of 0.04 m/s are compared with thoseof the hot-spot temperature. 3 ) It was found that theyagree with each other.
According to the calculation of the voltage development pertaining to the quench detection, the switching
off of the power supply can be made about .1 s after aquench. In addition, the effect of the delay time from 1
to 2 s is not large for the maximum temperature after
a quench due to the long current decay time.
We chose the value of 0.3 n as the dump resistance,
R m , considering the following requirements: (1) the
maximum temperature must not exceed 300 K (roomtemperature) even in the case of very low quench velocity which is the worst possible case; (2) in the caseof normal quench velocity, the maximum temperaturemust be approximately 100 K , which is the allowabletemperature for thermal expansion; and (3) the maximum voltage must be lower than 1.5 kV to facilitate
coil fabrication.
Current decay, temperature rise and voltage development of the superconducting main coil of SRC during a quench in the case of Rm = 0.3 n (Run# 1 inTable 1) are plotted in Fig. 2. As shown in Fig. 2
as well as in Table 1, the main coils of SRC are well
protected against the quench.
For the estimation of eddy current effects, the ACloss is calculated during the quench, as well as during the charge and disharge processes of the main
coils. Analytical expressions 4,5) were used for the calculation of hysteresis and coupling losses, while the
ELEKTRA a code was used for that of AC loss in the

Table 1. Results calculated by "QUENCH-M" program.
Run #

1
2
3
4
5
6

Vad,i

Tm ax

V max

VL

E in

(m/s)
4.1
0.04
4.1
4.1
0.04
4.1

(K)
131
185
136
98
109
102

(kV)
1.5
1.5
1.5
2.0
2.0
2.0

(V)
25

(MJ)
37
0
40
18
0
20

11

28
15
15
15

250

5

200 ;;Z:;; 2.0
8

150

1.5

;:l

OJ

.j.J

'"

---

100

1.0

50

~

Q)

E-<

0.0

Sectortt3 Sectortt4 Sectortt 5 Sectortt6

Fig. 1. Principal electric circuit for all superconducting
main coils of all six sectors of SRC.
a

'"

I-t
Q)

0

::- 0.5
50

Sectorttl Sectortt2

Q)

I-t

Q)

~

Ip-I

tsw
(s)
1.0
1.0
2.0
1.0
1.0
2.0

I: Operating current, 5000 A
L: Inductance, 18.8 H
Rrn: Dump resistance of main coil
Vad.i: Initial (adiabatic) quench velocity
Tm ax: Maximum temperature
V max : Maximum voltage in the circuit
VL: Maximum voltage between layers
Ern: Initial stored energy of 6 sectors, 235 MJ
E in : Dissipated energy in the superconducting coils
t sw : Time of switching-off of power supply

2.5
Ip

Rrn
(0)
0.3
0.3
0.3
0.4
0.4
0.4

Hitachi, Ltd.
ELEKTRA, Vector Field, Ltd., Oxford , UK

100
Time

150

200

0
250

(5)

Fig. 2. Current, I, maximum temperature, T max , the maximum voltage difference inside the coil, V max and voltage
drop across the dump resistor, RrnI of the superconducting main coil of SRC during quench, in the case of
Rrn = 0.3 n (Run#l in Table 1).

295

Al casing of trim coils . We adopted 100 s as a typicaltime of the current decay during the quench, as shownin Fig. 1, and 3600 s as a typical time of the charge ordischarge. The calculated results of AC loss of one-halfsector (upper or lower unit within one sector) for the
charge or discharge process as well as for the quench
process are listed in Table 2, in which the AC losses indifferent parts of the sector magnet are given as wellas in the entire magnet.
Figure 3 shows the distribution of the eddy current
for only one-half of the AI-alloy trim coil casing which
has a total thickness of 48 mm. In the contour plot ofFig. 3, the white region in the peripheral part of thecasing corresponds to the high-density of the induced
eddy current, while the dark region of the central part
corresponds to the low-density. It seems that this distribution of the eddy current results from the fact thatthe magnetic field component perpendicular (z direction) to the Al casing has a rather uniform distribution.
The total AC loss for the coil parts at 4.5 K during
the quench is about 1% of the stored energy (235 MJ).
In addition, there are AC losses in the iron pole andyoke at room temperature, which are not yet determined at present. The calculation of the quench protection was carried out on the assumption that all
stored energy is consumed by joule heating in the coil

Table 2. AC loss for the coil parts at 4.5 K of one-half sector.
Charge or discharge time1) Loss in coil
Hysteresis loss
Coupling loss within strand
Coupling loss in cable
Loss in Al matrix
2) Loss in vessel of main coil
3) Loss in casing of trim coils
Total Loss per half sector
Total Loss of all six sectors

3600 (s)1.8
1.70.0017
0.011
0.039
1.8
4.3
7.9
95

100 (s)
3.6
1.7
0.061
0.39
1.4
64
160
230
2700

or dump resistor, neglecting the eddy current effect.
However, it is expected that the maximum temperature is slightly bit lower than the calculated value
shown in Table 1 or Fig. 2, due to the eddy current
effect. The cooling scheme with two-phase helium for
the Al trim coil casing is designed on the basis of theheat input due to AC loss during the charge or discharge process, the radiation, etc.1 ) Currently, a slow
discharge with the small dump resistance (0.015 n) forsome accidents without quench is being planned, inorder to reduce the eddy current losses.
Following a quench, approximately 24 kg (0.2 m 3 ) of
heli um is expelled from the coil vessel through an exhaust pipe of 70 mm diameter and 10 m length. The
maximum pressure induced during a quench must be
estimated to ensure the structural integrity. The pressure rise and the mass flow from the vessel are calculated utilizing the Benedict-Webb-Rubin equation ofstate. The calculations are carried out for the worst
case, in which it is assumed that the state of the helium released is gaseous. Figure 4 shows the results
in which the pressure rise and the residual He mass inthe coil vessel and the mass flow rate in the pipe after a quench are plotted as functions of elapsed time.
On the other hand , if the state of the helium released
is liquid, the pressure drop along the exhaust pipe is
expected to decrease to about one tenth that in thecase of gas . It is expected that the maximum pressure within the He vessel will not reach the maximum
permissible pressure, 4 atm, because the actual helium
released is a mixture of liquid and gas.

en

60

0.6

50

~
0.5
p..
::;:
- 0.4

" '"

:

~

\ Mass flow rate

5

2-

40

<Jl
<Jl

30

3

20

2

oj

e

Q)

::r:

"
~

0

....
0
10

Time

Q)
;.J
oj

.--I

Pressure

10

OJ

2-

<Jl
<Jl
oj

::;:

(s)

Unit: kJ
Fig. 4. Pressure rise and residual He mass in the coil vessel ,and mass flow rate in pipe after a quench.
1000
500

~
;>.,

-500
-1000

4000

3000

x

5000
(mm)

6000

Fig. 3. Contour of Ij and vector plots of (jx, jy) for eddy
current density in the Al casing of trim coils.
1296

References
1) A. Goto et al.: Proc. 16th Int. Conf. on Cyclotrons andTheir Applications (Cyclotrons '01, 2001), to be published.
2) T. Tominaka et al.: IEEE Trans. Magn. 28 , 727 (1992).
3) T. Tominaka et al.: Proc. 17th Int, Conf. on Magnet
Technology (MT-17, 2001); IEEE Trans. Magn., to be
published.
4) Y. Iwasa: in Case Studies in Superconducting Magnets(Plenum Press, New York, 1994), p. 264.
5) K. Mess et al.: in Superconducting Accelerator Magnets(World Scientific, Singapore, 1996) , p. 104.

RIKEN Accel. Prog. Rep. 35 (2002)

Design study of beam transport lines from SRC to Big RIPS
K. Kusaka, T. Kubo, and Y. Mizoi
In the RI-Beam Factory (RIBF) project , energetic
heavy-ion beams from SRC will be delivered to projectile fragment separators, called Big RIPS ,l) to produce RI beams. Two Big RIPS separators will be
constructed, so that two different RI-beam experiments can be conducted at the same time. Big RIPSI is characterized by large-aperture superconducting
quadrupoles. Even projectile fragments produced byin-flight fission of uranium beams can be collected efficiently. On the other hand, Big RIPS II consists ofnormal conducting magnets whose apertures are similar to those of the present RIPS. These two separators
share primary beams from SRC by means of time sharing so that users of two separators can control beam
intensity independently. A design study of beam transport lines from SRC to two Big RIPS 's has been carried out , taking the constraints of building layout anddesign of magnets into account.
In this design study, we consider a fast pulsing magnet (PM) system with a ramping time of about 10 ms
for time sharing between Big RIPS I and II. The PM
will be operated in both DC and pulsing modes. An
example of the pulsing operation pattern for time sharing between Big RIPS I and Big RIPS II is shown in
Fig. 1.
A layout of beam lines, together with SRC and Big
RIPS separators , is schematically shown in Fig. 2. A
primary beam extracted from SRC by EBM, together
with other extraction elements, is t ransferred from the
SRC room to the IRC room by the quadrupole quartet (QQ). The dipole magnet D1 changes the direction of the beam by 20° and directs the beam to the
PM together with the quadrupole multiplet TQ and
DQ. While the PM is turned off, an unkicked beam istransported to the beam line to target T1 for Big RIPS
I. The beam line for Big RIPS I consists of two 50°
dipole magnets (R1-D1 and R1-D2) , a quadrupole doublet (R1-DQ) , and two quadrupole triplets (R1-TQ1
and R1-TQ2) , as shown in Fig. 2. The dipoles R1-D1
and R1-D2 are a 2-Tesla normal conducting bending
magnet (2TBM).2) While the PM is excited, on theother hand, the beam is delivered to a branch line
to target T2 for Big RIPS II, which consists of four
bending magnets , a quadrupole doublet (R2-QD) , andtwo quadrupole triplets (R2-TQ1 and R2-TQ2). The
bending magnets are a 17°-C-type Dipole magnet (R2D1) , a 50° 2TBM (R2-D2) and two 30 0 -2TBMs (R2D3 and R2- D4). We should note that the apertureof the last quadrupole triplets , R1-TQ2 and R2- TQ2 ,must be large in order to focus the beam to targets
T1 and T2 with small spot sizes. The bore radiusof the quadrupoles, except for R1-TQ2 and R2-TQ2 ,is 35 mm and the maximum field gradient is 22 T jm.

BigRIPS I

BigRIPS II

Pulsing
Magnet

,I
I

I

II

tOms

tOms

Fig. 1. Operation pattern of the pulsing mode.

Fig. 2. Schematic layout of the beam transport line from
SRC to Big RIPS separators.

On the other hand , the bore radius and the maximum
field gradient of R1- TQ2 and R2-TQ2 are 55 mm and17.5 T jm , respectively.3) Specifications of the bending
magnets are listed in Table 1.
The pulsing magnet power supply has been fabricated and tested for R&D studies. 4 ) The circuit of
the power supply consists of two parts. One is a forcing circuit which quickly energizes and de-energizes themagnet with a high voltage. The other is the main circuit to control the excitation current using a transistor dropper. The maximum output current is 1600 A.
The maximum output voltage in the pulse mode is2170 V and that in the DC mode is 65 V. The designed
switching time was shorter than 50 ms with a load magnet having inductance and resistance of 25.9 mH and297

Table 1. Specifications of the bending magnets.
SymbolType

Bending
Angle [deg]Bending
Radius [mm]Full Gap [mm]Maximum
Field [T]

Dl
RI-Dl
RI-D2
PM
R2-Dl
R2-D2
R2-D3
R2-D4

H
H
H
C
C
H
H
H

20
50
50
7
13
50
30
30

5000
4020
4020
9000
5300
4020
4020
4020

60
60
60
60
60
60
60
60

1.6
2.0
2.0
0.89
1.51
2.0
2.0
2.0

~

EBM

TQ

QQ

DI DQ PM

~
~

~

b
I:)

b

RI-TQ2

;:0

b
N

~

TI

(off)

l

(on)
± 30mm
W all

~~ 6
N

~

N

I:)

;:0

6- I:)
6

~

~

8

;:0

T2

N

6

.j:>.

R2-TQ2

Big RIPS II branch

Fig. 3. First-order beam envelopes for the beam line from SRC to BigRIPS I and II. Solid (dashed) lines
represent the horizontal (vertical) envelops .

33.3 mn , respectively. The rise time of 35 ms and thedescending time of 17 ms are achieved in test operations with a test load.
We are aiming at a switching time of ~ 10 ms withsmall modifications of the power supply by changing
the parameters of the load PM. The PM in the design is a C-type dipole magnet with a bending angleof 7° and an orbit radius of 9 m. Design values of its
inductance and resistance are 6.94 mR and 15.7 mn,
respectively. With these PM parameters, the expectedvoltage drop for a 5 msec rise time is 1675 V, which is
sufficiently smaller than the maximum output voltageof the power supply. Precise timing control of gate
turn-off thyristors that switch the forcing circuit on
andj or off and modification of the dropper transistor
control are planned to improve the power supply for~ 10 ms switching.
The same PM system is planned to be used in
the beam transport line from IRC, which is a preaccelerator for SRC. The beam extracted from IRC
is delivered simultaneously to both SRC and an existing experimental room in the RIKEN Accelerator
Research Facility (RARF).5) Two PM 's under consideration are designed such that the same power supply
can be used in common. The PM for the beam linefrom IRC is now being fabricated by Toshiba.
Figure 3 shows an example of calculated first-orderbeam envelopes of the beam lines from EBM to Tl
and T2. The assumed beam is 238U88+ with an energy298

of 350 MeV ju, which has the highest magnetic rigidity of 7.94 [Tm]. The beam shape at EBM is basedon calculated beam trajectories traced in SRC. 6 ) The
emittance of Ex = Ey = 31T" mm mrad and momentum
spread of b.pjp = ±0.05% are assumed. We have madethe ion-optical design so that the beam spot size on
the target Tl and T2 is 1 mm and the beam lines for
BigRIPS I and II are ion-optically identical, in otherwords, their transfer matrices are identical. The maximum value of the quadrupole-filling factor is designed
to be 50%. The beams on Tl and T2 are achromatized by tuning the quadrupole triplets Rl-TQl and
R2-TQl. FUrther optimization of the layout and magnet design is now in progress.
References
1) T. Kubo et al.: RIKEN Accel. Prog. Rep. 35 , 301(2002) .
2) T. Nagafuchi et al.: RIKEN Accel. Prog. Rep. 33 , 234(2000); Y. Mizoi et al. : RIKEN Accel. Prog. Rep. 35 ,
305 (2002).
3) Y. Mizoi et al.: RIKEN Accel. Prog. Rep. 35, 299(2002) .
4) H . Kouzu et al.: RIKEN Accel. Prog. Rep. 34 , 355(2001).
5) N. Fukunishi et al.: RIKEN Accel. Prog. Rep. 35, 283(2002) .
6) S. Fujishima et al. : RIKEN Accel. Prog. Rep. 35 , 293(2002).

RIKEN Accel. Prog. Rep. 35 (2002)

Design study of quadrupole magnets for the beam-transport line
and BigRIPS separator
Y. Mizoi, K. Kusaka, and T. Kubo
We designed 3 normal-conducting quadrupole magnets with high magnetic field gradients and large
Bore radii for the beam-transport line and normalconducting BigRIPS separator. 1)
Their types and specifications are summarized in Ta-

ble 1.
In order to obtain the excitation function of the
field gradient with a reasonably small saturation, andgood uniformity of the field gradient, we designed themagnets using OPERA-2d and -3d, for the 2- and 3-

Table 1. Specifications of the quadrupole magnets. Currents and power consumptions are the typicalvalues at the maximum field gradients.
Magnet nameField gradient (T /m)Bore radius (mm¢)
Pole length (mm)Current (A)Power consumption (kW)
Hollow conductor
Turn number
Water-circuit number

Q110
17.5
110
400, 800
325, 290
20, 239 x 9 mm 2 -¢6 mm
84
4/pole

Q160
12.5
160
800
485
53
10 x 10mm 2 -¢7mm
76
4/pole

Q200
9.0
200
800
406
49
10 x lOmm 2 -¢7mm
100
4/poleH;.-:-a-1-60-----/,-,,-,/-/-",-:J',(Y/800mm

A (0.80)
B (80, 113 14)
C(83. 54, 116. 68)0(130, 240)
E (130, 300)
F (300, 300)
G(460,460)
H(0, 460)
, '
II

I

,"'"

"

'-

\

I'

\

~--¢J160--J
\
,'
\

,

/

"

'

Q200
A(0, 100)
B (1 00, 141. 42)
C(103. 54, 144. 96)0(140, 250)
E(140, 340)
F (340, 340)
G(500, 500)
H(0, 500)

Fig. 1. Cross-sectional view of the quadrupole magnets, Q110, Q160 and Q200. Half of the poles and thecoils are drawn. Letters correspond to the points on the Cartesian coordinates located at the origin
in the center of the Bore radius. The shapes of pole end are also drawn.

299

20

30

15

QllO

Q200

Q160

25
15

~ 20

8'
t,

E
<U
;a 15

810

t,
E
<U
;a

E

a

:BIO
'"5b

~

~

"0

a

"0

i.i: 10

"0

11
5
Ll..

i.i:

5

--2D
--3D

0

0

0

100

0

200

300

400

--Ideal5--2D-- 3D(800mm)-- 3D(400mm)
500

100 200 300 400 500 600

0Current (A)0

100 200 300 400 500 600
Current (A)Current (A)Fig. 2. Excitation curve of the field gradient for Q110, Q160 and Q200. Q110 has two pole lengths,
400 mm and 800 mm.

0.00010.0001
Qll0

8'

0

8'

Q200
0

0

Q

Q

s -D.OOOIQ
8

8 -D.OOOI

8 -D.OOOI

9'

9'>< -D.0002
Q:>< -D.0002
Q:--6.95T/mC---- 1O.4T/m--- 13.9T/m'§ -D.0003
..2
'2

;:J

0 .0001
Q160--17.0T/m-D.0004

C'§ -D.0003
..2
'2

;:J

-D.0004

9' -D.0002--2.97T/m---- S.94T/m'§--12.63T/m..2 -D.0004'2

10 20 30 40 50 60
X (mm)---- S.OT/m---7.5T/m--9.1T/m;:J-D.00050--2.5T/m-;:: -D.0003--- 11.04T/m--lS.9T/m-D.0005><<5-D.0005
0 10 20 30 40 50 60 70 80 90
X (mm)

020

40 60 80 100
X (mm)

Fig. 3. Uniformity of the field gradient for Q110, Q160 and Q200 . The horizontal axis indicates the
distance from the center of the Bore radius.

dimensional field calculations. We used the B-H curveof SUYPO in the present calculations.
The cross-sectional view of the magnets are shownin Fig. 1.
Figure 2 shows their excitation curves . The resultsof 2-dimensional and 3-dimensional calculations areshown, and in addition , the ideal excitation curves arealso depicted . Although 3-dimensional effects of saturation are observed , comparing the calculated values
with the ideal ones reveals that the saturation of theexcitation curve is reasonably small in the region of

300

interest. Figure 3 shows the uniformities of the field
gradients of the magnets. The uniformity is very good
within the Bore radius.
We obtained a reasonable design of quadrupole magnets. In future studies, we will perform a multipole
analysis of these magnet.
References
1) T. Kubo et al.:(2000) .

RIKEN Accel. Prog. Rep. 33 , 236

RIKEN Accel. Prog. Rep. 35 (2002)

Projectile fragment separator BigRIPS for the RI-Beam
Factory project
T. Kubo, Y. Mizoi, and K. Kusaka
In this report we outline the projectile fragment separator BigRIPS, which is to be used for the productionof RI beams in the RIKEN RI Beam Factory project.
In the project, heavy-ion beams can be accelerated
up to 400 MeV/nucleon in the case of relatively lightelements and 350 MeV/nucleon in the case of heavy elements. 1) The maximum beam intensity is expected to
be as high as 1 pJ.LA, even for very heavy elements suchas uranium. Such high performance encourages us to
use in-flight fission of uranium beams as a production
reaction, in addition to the projectile fragmentation
reaction that has been commonly used to date. The
in-flight fission of uranium beams is very powerful forthe production of neutron-rich RI beams with mediumheavy mass, because it has much a larger production
cross section for this mass region. The BigRIPS separator has been designed taking into consideration theuse of in-flight fission, so that intensity of RI beams
can be significantly increased. The design goal of theseparator was that it could produce RI beams with ashigh an intensity as possible and that it could produce
RI beams as far from the stability line as possible.
We plan to build two projectile fragment separators,
which are named BigRIPS I and BigRIPS II. Figure 1 shows a schematic layout of the system. The
SRC is followed by a beam transport line,2) and thenby the two BigRIPS separators. These two separators
can share primary heavy-ion beams from the SRC bymeans of time sharing, which is achieved by placing
a pulsing magnet (PM) in the beam transport line. 2)This scheme allows us to conduct two different RIbeam experiments simultaneously.
The BigRIPS separators have been designed to bewhat we call a tandem fragment separator or a cascadeof two fragment separators. Each stage of the tandem
fragment separator forms an achromatic spectrometerwith intermediate focuses. The first stage serves to
produce and separate RI beams, while the second stage
serves to identify RI-beam species as well as to measure their momentum in an event-by-event mode. This
scheme allows us to deliver tagged RI beams to experimental setups placed downstream. RI-beam experiments would be significantly facilitated by this scheme
as emittance and purity of RI beams are expected to
be poor in our energy domain.
The main parameters of BigRIPS separators arelisted in Table 1. The BigRIPS I separator has been
designed taking into consideration the use of in-flight
Table 1. BigRIPS parameters .
BigRIPS I BigRIPS II
NormalQuadrupolesSuper
Angular acceptance [mr]20
Horizontal
80
Vertical100
30
3Momentum acceptance [%]6
Maximum magnetic rigidity [Tm]99Total length [m]7754
Momentum dispersion [cm/%]First stage-2.31 (F1) -2.1 (F1)Second stage
3.30 (F5) 0.57 (F3)
Momentum resolution *First stage
1300 (F1) 2000 (F1)Second stage
600 (F3)
3300 (F5)* First-order momentum resolution, for which object size

is assumed to be 1 mm.

Fig. 1. A schematic layout of the BigRIPS separator. Quadrupole magnets are indicated by STQn, TQn
and DQn, while dipole magnets are indicated by Dn. Fn denotes focuses.

301

fission of uranium beams. According to their reaction
kinematics at 350 Me V /nucleon, angular and momentum spreads of fission fragments amount to approximately 100 mr and 10%, respectively, when symmetricfission is assumed. The BigRIPS I separator has large
acceptances comparable to these values , so that it cancollect as many fission fragments as possible. Superconducting quadrupoles with large apertures and highfields are to be used for the BigRIPS I separator toachieve the high acceptances. The dipoles to be usedalso have a large gap , although they are normal conducting magnets. In the case of using projectile fragmentation reactions, the large acceptances can increase
the intensity of RI beams significantly, if the RI beams
are very far from the projectile or if the RI beams arelight isotopes. In these cases, the angular and momentum spreads of fragments are expected to becomelarger, according to the reaction kinematics of projectile fragmentation reactions.
On the other hand, the BigRIPS II separator has
been designed to have relatively small acceptances.
The acceptances were determined taking into consideration only the use of projectile fragmentation reactionsof medium-heavy projectiles, in which the angular andmomentum spreads of projectile fragments are muchsmaller than those of the fission fragments. Normalconducting quadrupoles with a small aperture are to
be used in this case. Dipoles are also normal conducting magnets. The acceptances of the BigRIPS II separator are sufficiently large to produce medium-heavy
and heavy RI beams using projectile fragmentation reactions.
The BigRIPS I separator is to be mainly used forexperiments using RI beams very far from the stability line, a subject which has never been studied before and is of great interest. Such experiments may becalled frontier experiments. On the other hand, theBigRIPS II separator is to be mainly used for what wecall factory experiments, in which systematic studies
are conducted by using a long beam-time.
As shown in Fig. 1, the first stage of the BigRIPS I
separator forms a two-bend achromatic spectrometer,
consisting of four superconducting quadrupole triplets(STQ1 to STQ4),3) each of which is installed in a single
cryostat, and two dipoles with a 30-degree bend (D1and D2). An energy degrader is placed at the intermediate focus F1 for isotope separation. A telescopic system consisting of two quadrupole triplets (STQ5 andSTQ6) placed after focus F2 transport RI beams to
the second stage. Thick concrete shielding surrounds
the first stage to prevent neutron radiation. The second stage, starting from focus F3, forms a four-bend
achromatic spectrometer, which consists of eight su-

302

perconducting quadrupole triplets (STQ7 to STQ14)
and four dipoles with a 30-degree bend (D3 to D6) .
The four bends allow a higher momentum resolution inthis stage, where the tagging of RI beams is achieved.
Tagging detectors are to be placed at focuses such as
F3, F5 and F7 to measure angles, positions, energy
loss, and time-of-flight of RI beams. The BigRIPS II
separator has a relatively simple configuration becauseof the constraints of the building layout. Both stages
are designed to form a two-bend achromatic spectrometer. The bends in the first stage are not symmetric:
30 degrees and 20 degrees. The momentum resolution
in the second stage is poor because of a small bending
angle (10 degrees). Tagging of RI beams may not bevery useful in the case of the BigRIPS II separator.
The superconducting quadrupole triplets in the concrete shielding (STQ1 to STQ5) are to be cooled bya large refrigeration system through a liquid-heliumtransfer line. Its cooling capacity is around 250 W at
4.5 K. This is because the quadrupole triplets, particularly the first two triplets, are exposed to high neutron radiation which causes significant heat loads onthe cryostat. The heat loads from the neutron radiation are estimated to be around 100 W .4 ) On theother hand the superconducting quadrupole triplets
downstream (STQ6 to STQ14) are cooled by a small
refrigeration system whose details are reported elsewhere .5 ) The small refrigeration system is mounted on
the cryostat of each quadrupole triplet . We adopted
this scheme because the neutron radiation is expected
to be low in the second stage. This scheme reduces the
fabrication cost significantly.
Each BigRIPS separator is to be followed by RIbeam delivery lines, which transport the tagged RI
beams to different experimental setups placed downstream. The building is to be extended at the left-handside shown in Fig. 1 to accommodate the RI-beam delivery lines and the experimental setups.
The fabrication of the BigRIPS separators begins
next year .
References
1) Y. Yano: RIKEN Accel. Prog. Rep. 34, 301 (2001) .
2) K. Kusaka et al.: RIKEN Accel. Prog. Rep. 35, 297(2002).
3) T. Hirumachi et al.: IEEE Trans. Appl. Supercond. 10,
236 (2000); T. Kubo et al.: RIKEN Accel. Prog. Rep.
33, 238 (2000); H. Kouzu et al.: RIKEN Accel. Prog.
Rep. 34, 350 (2001); T. Tominaka et al.: RIKEN Accel.
Prog. Rep. 34, 353 (2001).
4) T. Mukhopadhyay et al.: RIKEN Accel. Prog. Rep. 33,
241 (2000).
5) K. Kusaka et al.: RIKEN Accel. Prog. Rep. 35, 303(2002) .

RIKEN Accel. Prog. Rep. 35 (2002)

Superconducting quadrupole magnet with small refrigerators
K. Kusaka, T. Kubo, T. Tominaka,*l Y. Mizoi, Y. Yano,N. Kakutani,*2 T. Tsuchihashi,*2 and O. Ohsaki*2
Superconducting quadrupole magnets are to be used
for the BigRIPS separator in order to efficiently produce RI beams.1,2) Two types of cryogenic system forthe quadrupoles are planned .
The cryogenic system for the quadrupoles locatedclose to the production targets and beam dumps isan integrated system with a large cooling capacity, inwhich a single refrigerator supplies liquid He (LHe) toa number of magnets through transfer lines. Since themagnets are exposed to high neutron radiation, a large
cooling power for the refrigerator system is required
due to large heat load of neutron radiation.
Another system is a stand-alone-type superconducting magnet equipped with small refrigerators on its
cryostat. The stand-alone type magnet is financially
preferable, since no big cryogenic plant is necessary.
The stand-alone-type magnets are to be used in theanalyzing section of the BigRIPS where the possible
radiation level is reasonably low. In this report, wesummarize the design of a superconducting quadrupole
magnet with small refrigerators.
A prototype of the superferric quadrupole triplet has
been fabricated and tested for R&D studies. 1 ,2) The
main parameters of the magnet are listed in Table 1.
The magnets are installed in a dewar-type cryostat andcooled by the LHe bath cooling method. We designed
a new cryostat with small refrigerators based on the
prototype cryostat by reducing heat load as much as
possible. A cross-sectional view of the cryostat withsmall refrigerators is shown in Fig. 1.
We show, in Table 2, the estimated values of the heatloss of the superconducting quadrupole magnet with
Table 1. Main parameters of Q500 and Q800 quadrupoles.
Effective magnetic length [m]Pole tip radius [mm]Warm clear bore radius [mm]Max field gradient [T jm]
Winding of coil
Nominal current per pole [kA]
Nominal current [A]Nominal current density [Ajmm 2 ]Straight length of coil [mm]Total length of coil [mm]Length of iron [mm]Outer radius of yoke [mm]Inductance [H]Stored energy [MJ]*1

Hitachi, Ltd.

*2 Toshiba Corporation

Q500

Q800

~0.54

~ 0.84

170
140
14.1
orderly
199
142
115
440
640
440
480

170
140
14.1
orderly
190
136
110
740
940
740
480

12 ~ 2018 ~ 28

0.13

0.19

Fig. 1. Quadrupole triplet with small refrigerators.

small refrigerators. Those of the prototype cryostat
are also listed for comparison. A key to reducing heatloss in the He vessel is new current leads. The numberof the current leads for three quadrupole magnets is
reduced from 6 to 4 and a high-Tc superconducting
material is used to reduce Joule heat.
A Gifford-McMahon/Joule-Thomson (GM/JT)
cooler , mounted on the 4 K port , is used to cool the
He vessel. It liquifies He gas that evaporates in the
He vessel with the recondensing heat exchanger unit.
The cooling capacity of the GM/ JT cooler is 2.5 W at
4.3 K. When the magnets are operated under a constant current , the margin of cooling capacity over theheat load is expected to be 0.58 W.
A Gifford-McMahon (GM) cooler is mounted on thecurrent port of the cryostat. It cools the 80K shield andthe high-Tc superconducting current leads (HTCL) byheat conduction. The cooling capacity of the GM
cooler is 90 W at 80 K and is sufficient to cool HTCL
and the 80 K shield at all times. Both refrigerators
operate using separate water-cooled compressors.
Since the cold mass of the magnet is too large forsmall refrigerators to cool from room temperature to
4 K , precooling with liquid N2 and LHe is necessary.
The service port is used to transfer LHe and liquid
N2 from an external storage. A pressure release valve(0.05 MPa) , a bursting disk (0.1 MPa) , and t erminals
for sensors are also installed on the service port.
The excitation circuit for the quadrupole triplet isshown in Fig. 2. If an abnormal voltage drop of HTCL
is detected or HTCL is broken, the current lead protection switch cuts the power supply output and the303

Table 2. Expected heat loss (unit [W]) of two cryostats.

He Vessel

80 K Shield

Type of Heat Load
Parts
Thermal Shield
Radiation
SupportConduction
C urrent Lead Conduction+Joule heatGas H e Port
Conduction
Bellows
Conduction
Coil (Triplet)
AC loss ( 1 A/s ramp.)
Total
Vacuum Vessel
SupportCurrent LeadGas He Port
Bellows

Radiation
Residual Gas
Conduction
Conduction+Joule h eat
Conduction
Conduction
Total

Power Supply Unit

with small refrigerators
magnet status(de- )energizing energized de-energized
ff0.18
ff0.65f0.2/4P
0.49/4P..f0.58
ff0.17
f11.4
0
13.32
1.82
1.92
GM/ JT capacity 2.5 W at 4.3 K
7.11

Cryostat

HTc

Current
Lead

Current Lead
Protection Switch

Fig. 2. Excitation circuit of the quadrupole triplet.

stored energy of the magnet is dissipated in the diodes
in the He vessel. On the other hand, if quenching of acoil occurs, the power supply is switched off due to the
output overvoltage, so that the current is discharged
through the diode in the power supply unit and thestored energy is dissipated in the coil. In other abnormal cases, e.g. , a failure of a refrigerator, the stored
energy is transferred outside of the cryostat and is dissipated by the diode in the power supply. The current
is discharged with the speed of 1 A/s in this case.
Since the heat loss of the He vessel exceeds the capacity of the GM/ JT cooler when the power supply
sweeps the excitation current, we estimated the pressure increase. If the He vessel is fully filled with ~600 L of LHe, the pressure of the He vessel reaches its
relief pressure after 8.5 minutes of continuous changeof the current at a rate of 1 A/s. If the magnets are

304

..-

f-

ff0.55
ff12.34
f28.9/4P
18.4/4P
ffN/A
ff1.31
f50.2139.71
GM capacity 90 W at 80 K

prototype cryostat (dewar type)magnet status(de- )energizing e nergized de-energized
ff0.1 8
ff0.65..0.49/6P
0.97/6P..f0.69
ff0.82f11.4
02.87
14 .75
3.35
7.11
0.55
12.34
N/A
4.71
5.13
29.84

f-

f-

f-

f-

f-

f-

f-

f-

f-

f-

..-

f-

f-

+-

kept energized (de-energized), the excess cooling capacity of the GM/ JT cooler reduces the pressure fromits limit to atmospheric pressure within 1.7 hours (1.4
hours). In a standard operation of the fragment separator, the current ramping rate is expected to be -0.3 A/s, when the current is changed to a large extent.
Al though a rapid change (close to 1 A / s) may be required for fine adjustments, the period is expected to
be several seconds in this case. We thus expect thatthe pressure of the He vessel seldom exceeds its relief
pressure.
If water and/or electric supply is suspended for along time, LHe in the He vessel will evaporate and willthen be lost as a relief gas. About 84 L of LHe will belost if the refrigerator stops functioning for 24 hours.
The entire amount of LHe (~600 L) in the He vessel
will be lost if the refrigerator stops functioning for 3
days. A backup for the electric and water supplies of
the refrigerators is important.
To test the cryogenic system of the superconducting quadrupole magnet with small refrigerators, a new
cryostat is currently being fabricated in Toshiba. The
cryostat of the prototype has been disassembled andthe magnets in it are ready for reinstallation in the
new cryostat. Cooling and excitation tests will be performed in the near future.
References
1) T. Hirumachi et al.: IEEE Trans . Appl. Supercond. 10,
238 (2000).
2) H. Kouzu et al.: RIKEN Accel. Prog. Rep. 34, 350(2001); T. Tominaka et al.: RIKEN Accel. Prog. Rep.
34, 353 (2001).

RIKEN Accel. Prog. Rep. 35 (2002)

Design study of 2 Tesla dipole magnet by three-dimensional
calculation
Y. Mizoi, N. Kakutani,* K. Kusaka, and T. Kubo
We are studying the design of a 2 T dipole magnet (2 T) with normal-conducting coils for the beamtransport line from SRC l ) to BigRIPS 2 ) separators.
Two-dimensional magnetic-field calculations were performed by Nagafuchi et al. 3 ) and the 2 T cross section was determined.
In order to estimate thethree-dimensional effects, we are performing threedimensional calculations by means of OPERA-3d.
Figure 1 shows the schematic view of 2 T. Although
the radius of 2 T presented by Nagafuchi et al. 3 ) was
3.75 m, the present radius is 4 m, because the magnetic
rigidity of SRC has been upgraded. In addition, thebending angles of 2 T are also changed to 30 and 50
degrees from 30 and 70 degrees, respectively, according
to the results of a beam-optics study. Figure 2 shows

the cross-sectional view of 2 T, which is the same as
the previous one.
In the present calculations, we use the B-H curve of
SUYPO, and the ends of the poles are cut with C30
for the first trial. Figure 3 shows the excitation function of 2 T in the case of a bending angle of 30 degrees. Compared with the ideal excitation curve, the2 T saturation is sufficiently small for satisfactory operation. Figure 4 shows the uniformity of the magnetic
field at the center of 2 T. The uniformity of the magnetic field is reasonably good in the region of ±50 mm
within 10- 4 . This is consistent with the results of twodimensional calculations. 3 ) The present specificationsof 2 T are summarized in Table 1.
For subsequent trails, we will perform multipole

3
Fig. 1. Schematic view of 2 T.

12,00

668

- - - - - - - - - - - - - - - -'1<---' ....""""""

1immmmPrl-_- - - - -- - - - - - - - -Fig. 2. Cross-sectional view of 2 T.
Toshiba Corporation305

3.5 , - - - - - - - - - - - - -- - - - -- - - - - - - ,

E 2.5
"U

V

<.::

-+-Ideal-ill-

2

20 (axial symmetry)...... 3D calculation()'t 1.5
~

~

1

0.5

o ~-~-~-~-~-~-~-~-~-~--~~o 100 200 300 400 500 600 700 800 900 1000 1100
Current (A)Fig. 3. Excitation curves of the magnetic field by the 3D calculation. The ideal excitation curve and theresults of 2D calculation are also plotted.

0.0005Preliminary

0.00040.00030.00020.0001

o

o

~
CD

~ -60

fg

-0.0001-00002-0.0003-0.0004-0.0005

X (mm)

Fig. 4. Uniformity of the magnetic field.

Table l. Specifications of 2 T.
Main parameter
Magnetic rigidity
Bending radius
Bending angle
Field strength
Pole gap
Good field region
Nominal current at 2 T
Nominal power consumption at 2 T
Coil parameter
Turn number
Hollow conductor of inner coil
Hollow conductor of outer coil
Water-cooling-circuit number

analysis around the pole ends with Rogowski shape.
References
1) Y. Yano et al. : Proc. 15th Int. Conf. on Cyclotrons andTheir Applications , Caen, France (1998), p . 696.

306

8.0Tm
4.0m
30, 50 degrees
up to 2.0T
60mm
±50 mm within 10- 4
723A
66 kW for 30 degrees, 95 kW for 50 degrees
70/pole, (inner 10 + outer 60)
W15.5 mm (W) x Hll.5 mm - ¢8 mm
W2 turn x H5 turn
W16mm x HI6mm-¢lOmm
WI0 turn x H6 turn
8/pole (inner 2 + outer 6)2) T. Kubo et al.: RIKEN Accel. Prog. Rep . 33, 236(2000).
3) T. Nagafuchi et al. : RIKEN Accel. Prog. Rep. 33, 234(2000).

RIKEN Accel. Prog. Rep. 35 (2002)

Studies on MUSES control system using RT-CORBA
T. Tanabe, T. Masuoka, M. Takano, and T. Katayama
Common Object Request Broker Architecture(CORBA)l) is the standard distributed object architecture for an open software bus, which allows programs created by different operating systems (OSs)and languages to communicate with each other . In ourprevious R&D efforts ,2) we confirmed interoperability
through nop among different ORBs. It has also beenshown that the performance degradation compared tothat of pure socket communication is insignificant.
The recent introduction of RT-CORBA specifications allows us to utilize the full capability of RTOS
such as VxWorks. 3 ) RT-CORBA augments the shortcomings of regular CORBA 2.x specs, namely, the lackof quality of service (QoS) controls, real-time programming features and performance optimizations. Amongthe various features of RT-CORBA , we have mainly
examined processor resources control such as threadpools, priority mechanism and intra-process mutexes.
VisiBroker 4.1a for Tornado 4 ) and ORBexpress-RT
2.3.25) were chosen for comparison.
RT-CORBA mutex operations would conceal thedifference in the thread-synchronizing mechanism inthe underlying OS. We have compared the elapsed
times of lock() /unlock() operations that are repeated1000 times for (a) VxWorks native semTakeO, semGiveO , (b) rtMutex -> lockO , rtMutex -> unlockO for
VisiBroker, (c) the same for ORBexpress . The elapsed
time was measured by "WindView" tool. 3 ) The results(average time for 1000 operations in msec and standard deviation) are shown in Table 1. It appears thatthe latency caused by RT-CORBA abstraction is lessthan 1 J-Lsec and considered to be negligible for mostaccelerator applications.
Thread pools can be defined and associated using
the Portable Object Adaptor in an RT-CORBA server.
They can have both a fixed number of static threads,
and dynamic threads whose maximum number shouldbe specified. With a proper priority mapping, RTCORBA priorities can also conceal the variations of native priority mechanism of RTOSs. For example, VxWorks has the highest priority of 0 and pSOSystem has
255 as its highest. The highest RT-CORBA priority isalways 32767. There are two types of Priority Model
policies, "server declared" and "client propagated."
We have set ORB's priority at 25 and that of VxWorks
at 155, and measured the connection time for boththe server-declared model and the client-propagatedmodel. For both static and dynamic threads, twothreads can be created in the test program. Since
ORBexpress-RT 2.3.2 lacks create_threadpool() API,
this test was conducted only in VisiBroker.
First, with the help of WindView, it was confirmed that VxWorks tasks could be switched basedon CORBA priorities. Then , the time required to establish the connection b etween a client and a servant
for the server-declared model was measured (Table 2).
For dynamic threads, the default timeout to destroy
them is 300 seconds. Measurement was carried out
for both cases, one with existing threads and one after
their disappearance. The same type of measurement
was done for the client-propagated model and the results are summarized in Table 3.
The results indicate that the initial connection always takes longer because the POA manager has to be
activated. However, from the second time and therafter, there is not much difference among the various
cases we tested . Even though there are still more functionalities to be tested in RT-CORBA, the processor
resource controls appear to be satisfactory.
Table 2. Connection time for server-declared model.
Static Thread
Init. Connection From 2 nd Connection
Ave (ms) 4.623
3.308
St. Dev.
0.143
0.008
Dynamic Thread
Init. Conn. From 2 n d
From 2 nd
w. threads
w.o.threads
Ave (ms) 4.800
3.326
3.581
St. Dev.
0.012
0.125
0.152
Table 3. Connection time for client-propagated model.
Static Thread
Init. Connection From 2 nd Connection
Ave (ms) 4.621
3.491
St . Dev.
0.175
0.016
Dynamic Thread
Init. Conn. From 2 nd
From 2nd
w. threads
w.o.threads
3.545
3.801
Ave (ms) 4.801
St. Dev .
0.010
0.190
0.195

References
Table 1. Comparison between VxWorks semaphore andrtMutex.
Ave. (ms)
St. Dev.

Semaphore
2.092
0.00625

VisiBroker
2.334
0.00833

ORB express
2.742
0.005

1) http: //www .omg.org/
2) http: //accelconf.web.cern.ch /accelconf/eOO/ PAPERS/
TUP 4B 15. pdf3) http: //www .windriver.com/
4) http: //www.borland.com/
5) http: //www.ois.com/

307

RIKEN Accel. Prog. Rep. 35 (2002)

Update of MUSES ACR lattice design
H. Tsutsui,* K. Ohtomo,* and T. Katayama
After two of the authors had completed the designfor the lattice of the Accumulator Cooler Ring (ACR)of Multi-USe Experimental Storage rings (MUSES)
last year,!) the required transition gamma '"'iT for thecooling mode was lowered 2 ) ('"'iT = 2.6 -7 1.6- 1.7) inorder to optimize the longitudinal stochastic coolingefficiency by the notch filter technique. Consequently,
this report describes a new ACR lattice design study
with lower transition gamma.
Theoretically, in order to decrease '"'iT one should increase the horizontal dispersion function D x in bending
magnets (BMs) and/or decrease the circumference C:

Table 1. Lattice parameters of the ACR.

C (m)Ring size (m)Max. Bp (T m)
Tune Q x,yMax. /3x,y (m)Max. Dx (m)Natural ~x , yIT,pk,'kp.6.Q (x, y) ,pk/3x,y at SC (m)2.. ='"'i; -Q=c -~ fds D x = 27r(D x )BM,
C

P

C

(1)

L se (m)/3x,y at EC (m)LEe (m)where Qc, p, (Dx ) BM are the momentum compaction
factor, the curvature radius of the reference orbit, andthe average of the dispersion function in BMs, respectively. Since the circumference should be sufficiently
long to incorporate all accelerator elements, we choseC = 134.8 m, which is four times the extraction orbit
length of the Superconducting Ring Cyclotron (SRC).
By applying Eq. (1), the average of the dispersion function should be (Dx)BM = 8.4m. Another requirement
is that the dispersion function should be free in thecooling section, thus, the maximum dispersion function in the arc section should be around 20 m or more,which results in a large horizontal beam size in the
middle of the arc section.
We used two methods to decrease '"'iT without greatly
increasing the maximum D x . First, we replaced thelow dispersion arc (B-arc) with a high dispersion arc(A-arc). In the case of the lattice in the previous report , the replacement changed '"'iT from 2.56 to 1.95.
Second, we moved a portion of the BMs to a higher
dispersion function region. In the previous report , theratio of the BMs in the low dispersion region to thosein the high dispersion region was 2: 2, and the total
number of BMs was (2 + 2) x 4 = 16, as shown in Table 1. We tried 1: 3 and 2: 3 schemes, and adopted the2 : 3 scheme because in the 1 : 3 scheme only one BM
in the low dispersion region could not generate a large
dispersion function in the high dispersion region. The
ratio 1: 2 or 2: 4 may be another solution. However,the bending angle in the 1 : 2 scheme is 30° which may
be too large to fabricate a BM, and we require manyBMs in the 2: 4 scheme, which results in a larger circumference.
In order to cool the beam efficiently by Stochastic
Cooling (SC) , there are two other requirements forthe lattice; that the local transition gamma from theSumitomo Heavy Industries, Ltd.

308

(3x,y at inj. pt.

(m)ax ,y at inj. pt. (m)D x at inj. pt. (m)D~ at inj. pt. (m)No. of BMs
ratio of BMs*
No. of Quadrupoles
No. of Sextupoles

prev. report 1)
134.8
50.7/29.8
8
3.23/2.58
28.6/31.6
15.3- 3.1/ - 3.0
2.562
1.688/5.489
0.75/0.75
15/10
6
4.0/14.3
9.5
12.5/5.0
0.0/0.0
4.4
0.0
16
2:2
33
16

this report
134.8
53.7/25.4
8
2.27/3.81
74.0/31.3
20.0-4.0/2.0
1.611
1.342/1.841
0.75/1.75
25.2/14.8
6
3.3/29.9
10
5.8/7.0-1.3/ - 0.11
3.2
-0.99
20
2:3
38
20

*) Ratio of the bending magnets in the low dispersion
function region to those in the high dispersion function
region.

pickup to the kicker '"'ipk which is defined as_1_ = _1_1kicker dsDx = 7r(D X )BM,2'"'ipk-Lpk

pickup

P

L

pk

(2)

where Lpk is the orbit length from the pickup to the
kicker, should be small, and that the horizontal andvertical betatron phase advances from the pickup to
the kicker ~Q x,pk' ~Qy ,pk' should be quarter of odd
integers. From Eq. (2), Lpk should be small.
We used MAD8 3 ) and WinAGILE 4 ) to find a latticewhich satisfies the above requirements. The resultant
layout and Twiss parameters of an updated ACR are
shown in Fig. 1 and Fig. 2, respectively. One finds large
rises and falls of the beta functions in the arc section,
which may be inevitable in this type of extremely low'"'iT lattice with long dispersion-free regions.
We estimated the dynamic aperture and injection
efficiency for the present low '"'iT lattice. After the horizontal and the vertical chromaticities were correctedby applying the sextupole fields, the dynamic aperture
was calculated as shown in Fig. 3. It indicates that the
dynamic aperture is sufficiently large compared to thebeam acceptance . The multiturn injection efficiency
was calculated as a function of the injection turn number for various injection beam sizes and septum thick-SCpiC~EC~

Parameters of ACR cooling mode

Hlgb Dlsperston
RegIon~~;~ispersion ~Crrcwnference
134.788 m
Magnel1C ngldity
4-8 TmMax acceptance
125/40 mnm-mrad HIgh DIspersIOn
Max momentum acceptance ± I %RegIOnInjechon emtttance
5/40 mnm-mradBetatron tune QxJQy
22713 81
TranSll10n gamma
1 611

Low DIspersion
Region

1000

on

.,.
on

M

i

OJ

soo

Low Dispersion
Region ,......--~ RF cavityr". ~O'x=2mmi/ / ' ,

"'r
i

'/

"

,~eptum: Smm. ,. . '.., . .

G;2mm

, .;..~>~

0'.11 -

SC kicker

4mm '

40

..... - -. ...
50

Fig. 4. Multiturn injection efficiency of the ACR for several
septum thicknesses (2 mm , 4 mm, 6 mm) and horizontal
sizes of the injection beam ((J"x = 1 mm, 2 mm, 4 mm).

Fig. 1. Layout of updated ACR.

80.

" ..............

eptum: 6mm" ..... ,...

20
30
Injection Turn Number

53716

!

Septum : 4mmi141111fJ1 17.23.45 25.0

!

22.5

ci

70.

20.0

60.
17.5
50.

15.0
12.5

40.

10.0

]0.

7.5
20.
5.0
10.

2.5

0.0

70.

0.0

80.

0.0

sCm}

Fig. 2. Twiss parameters of the ACR.
Fig. 5. The concept of an insertion device to lower the transition gamma.

IO

e

€

&

<u

'0'

S

E
E
E

.~

~

'5

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'0

~

~

§

Z

e
6

Io!
0

if>- 4

~:

2

;>.,

°_6

°

-4
-2
2
Normalized Horizontal Dynamic Aperture(xl ~x,Ax=125 1t mrn mrad)Fig. 3. Dynamic aperture of the ACR at the center of theelectron cooling (EC) section with ~p/p = ±1 %. The
particles were tracked by MAD8 3 ) for various initialtransverse positions (x , y) normalized by the beam size.

sertion devices. 6 ) Direct application of the method
shown in the reference to our case is not efficient because the dispersion function has a large amplitude
variation in the device. In our case, an insertion device of the kind shown in Fig. 5 may be more efficient. By using a device of 'YT,ins, the new 'YT will be
1/ 'Y~ new = (C / 'Y~ + L / 'Y~ ins) / ( C + L), where L is theorbit' length of the device.' This may be studied in the
future.
The RF stacking process should be simulated, andthe isochronous mode operation should also be studied
carefully in the future.
References

nesses, as shown in Fig. 4. In the calculation, the bumpfields decay linearly during injection. Emittances andthe momentum spread of the beam from the Big-RIPS
are assumed to be 5 (horizontal) /40 (vertical) 7rmmmrad and 0.15%,5) respectively. The efficiency reachedaround 1000% using a thin septum. The lower efficiency than in the previous report may be due to lower(3x at the injection point.
Another possible way to decrease 'YT is to use in-1) K. Ohtomo et al.: RIKEN Accel. Prog. Rep. 34, 357(2001).
2) M. Wakasugi: private communication.
3) H. Grote and F. C. Iselin: CERN/SL/90-13 (AP) Rev. 5(1996).
4) P. J. Bryant: Proc. European Particle Accelerator Conf.
2000 (2000), p. 1357.
5) C. C. Yung: 138th MUSES Meet. (Beam Physics andEngineering Laboratory, RIKEN), Wako, Sep. (2001).
6) M. Giovannozzi et al.: Proc. European Particle Accelerator Conf. 2000 (2000), p. 1030.

309

RIKEN Accel. Prog. Rep. 35 (2002)

Design of MUSES electron cooler at RIKEN
M. Nishiura, T . Tanabe, T. Katayama, E. Syresin,*l and 1. Watanabe*2
The Radioisotope Beam Factory (RIBF) is underconstruction at RIKEN. 1) In the RIBF, multi-use experimental storage rings (MUSES)2) consists of an accumulator cooler ring (ACR) and an electron-RI beamcollider (e-RI Collider). The ACR is equipped with anelectron cooler (EC).
The design of the EC for the ACR has recently
been proposed and discussed. 3) It was found that it
is not necessary to use the high magnetic field of afew Tesla in the gun section,4) because the ion lifetime
is reduced due to the fast recombination of ions with
low-temperature electrons. Moreover, the reduction of
the electron transverse temperature from the cathodetemperature of T cath = 100 meV to T e = 5 meV produced by the magnetic expansion of the electron beam
does not provide a significant advantage in terms ofcooling time during the injection. Syresin et al. 5 ) reported that the magnetic expansion factor Bd B coolfrom 1 to 8 is sufficient to cool the 92U 238 coasting
beam with E = 100 MeV ju, t6.pjp = ±1.5 X 10- 3,
and Cv = 407r·mm·mrad. Here Bi and B cool are themagnetic field in the gun and in the cooling section,
respectively.
On the basis of the previous ACR-EC design ,3) werefined the design of the electron gun, the collector
and the magnetic field strength with the help of thecomputer simulation codes SAM6) and EGUN.7) In Table 1 the new parameters of the ACR-EC are listed; themaximum Bi is reduced from 4 T to 4 kG, and therefore the ratio of Bd B cool is decreased to be 2.5 times
smaller than the previous one.
The electron gun proposed for the ACR-EC consistsof three electrodes: a flat cathode, a Pierce electrode,and an anode. The electron beam is finally acceler-ated up to 220 keY , and introduced into the cooling
section through a toroidal section. For simplicity, thetoroidal section is assumed to be a linear section in thissimulation.
The magnetic field on the beam axis is calculated inr- z coordinates. The input parameters used here areshown in Table 2. Figure 1 shows the dependence ofthe transverse temperature E tra on B cool calculated by
SAM and EG UN. The transverse temperature calculated by SAM tends to be lower than that calculatedby EGUN at the beam edge. In both cases E tra becomes less than 1 eV at the beam edge, and less than
100 meV at r = 5.436 mm, and depends on the cathodetemperature at the center of the electron beams.
It is desirable that electron beams for an EC havea low transverse temperature. Since the initial velocity of electrons emitted from the cathode determines
the final transverse temperature , the electric field infront of the cathode should be vertical to the cathodesurface. Two anode shapes are proposed as shown in
Fig. 2 for the comparisons of the transverse temperature. Figure 3 shows the dependence of the transverse
temperature in the cases of Al (previous anode shape)

Table 2. Input parameters for EGUN.
Electron beam current, A
Electron energy, ke V
Cathode-anode voltage, k V
Cathode diameter, cm
Magnetic field in gun section, kG
Magnetic field in cooling section, kG

4
220
30
2.57
4
0.5- 2

Table 1. ACR parameters. 4 )Circumference, m
Ion energy, Me V / u
Beam acceptance, caee p , 7r·mm·mm
Maximum momentum spread, %Emittance of injected beam, Cinj, 7r·mm·mm
Initial momentum spread, %Beta function in cooler (hor. / vert.), m
Length of EC solenoid , m
Magnetic field in cooling section, kG
Magnetic field in gun section , kG
Magnetic expansion factor
Electron beam current , A
Electron energy, ke V
*1
*2

310

JINR, Russia
Toshiba Corporation

134.788
60- 400
125/40
±1
5/40
±0.15
4/14.34
3.6
0.5- 22- 4
1-8
4
30-25010 ~----~----~~----~----~----~
1.0
0.0
0.5
1.5
2.0
2.5
Beaal [kG]

Fig. 1. Transverse electron temperature in the cooling section calculated by SAM (dotted lines) and EGUN (solidlines). The value of r indicates the radial beam positionat the dispenser cathode.

Fig. 2. Cross-sectional view of previous anode shape (AI)and modified anode shape (A2).

$'
Q)

oS

BCOOI [kG]

Fig. 3. Dependence of the transverse temperature on themagnetic field in the cooling section. Open and solid
circles indicate the cases of Al and A2, respectively.
Dotted lines for E tm show the results calculated by
SAM in the case of A2.

and A2 (proposed anode shape). The electron beams
in the case of the new A2 shape have a lower transverse
temperature than those in the case of the previous one,and yield a 20% improvement of E tra by SAM and a50- 90% improvement by EGUN near the beam edge.
A higher uniformity of E tra is also achieved.
In the collector section of the ACR-EC, the beam
trajectory calculations have been carried out. The initial beam parameters are taken from the final beam
parameters calculated above in the case of Bd B eool =4 kG / (2- 0.5 kG). When the expansion factor is higher,
the beam radius is very close to the deceleration tube
radius. In order to prevent beams from hitting the walland the electrodes, the focus lens should be placed in
front of the entrance of the collector.
The feasibility study on triode and cooling sections
for the ACR-EC will be carried out using a threedimensional simulation code.
References
1) Y. Yano et al.: Proc. PAC '97 (1998), p. 930.
2) T. Katayama et al.: Proc. EPAC '98 (1998), p. 529.
3) T. Tanabe et al.: Nucl. Instrum. Methods Phys. Res. A
441, 104 (2000).
4) T. Tanabe et al.: to be published in Proc. CoolingWorkshop 2001, Germany.
5) E. Syresin et al.: to be published in Proc. Cooling Workshop 2001, Germany.
6) M. Tiunov, B. Fomel, and V. Yakovlev: Preprint Budker Institute of Nuclear Physics 1, 159 (1985).
7) W. H. Herrmannsfeldt: SLAC-226, 1 (1979).

311

RIKEN Accel. P rog. Rep. 35 (2002)

Instability during electron-cooling bunching,predicted from a simulation
M. Takanaka
The Radioisotope Beam Factory (RIBF)l) will havean electron-RI beam collider (e-RI Collider). In previous works, using a multiparticle tracking simulation where the three-dimensional space-charge force
is taken into account, we studied ion-beam electroncooling bunching to prepare the required ion beam at
the e-RI collider, and described the characteristics ofthe bunched beam. 2 ) Here we review only the instability of the beam.
In order to simulate the electron-cooling bunching of
an ion beam, we have used a model where the following
sources of forces acting on ions are taken into account:• Longitudinal monopole space-charge impedanceon the assumption of a transverse Gaussian beamcharge distribution and a cylindrical vacuum
chamber.
• Transverse space-charge field including the influence of the chamber wall, calculated from a transverse charge distribution .
• Transverse dipole broad-band impedance based on
the broad-band impedance model, corresponding
to a horizontal broad-band impedance ~of 50 n.
p
• Electron-cooling (EC) force.
• Solenoid field Bo at the EC section.
• Beam twist due to the toroid field at both ends ofthe EC section.
• A constantly focusing section and a drift EC section which the ring lattice is let to consist of.
• RF field for beam bunching.
Using 40,000 macroparticles, we simulated the EC
bunching of 238U92+ ion beams of 4 rnA, or of 5.4 x 10 6ions per bunch at 150 MeV lu.
One of the simulation results is the time evolution
shown in Fig. 1. First, the coasting beam is cooled tothe sixfold-rms momentum spread of 5 x 10- 4 . Then,the fundamental RF voltage is increased in such a waythat the momentum spread at the EC section is maintained at 5 x 10- 4 . The RF voltage increase stops
when the sixfold-rms bunch length reaches 1 m. Whenthe momentum spread reaches 1.9 x 10- 4 or most of
the beam stays within the one-third bunch spacing,
the third-harmonic RF voltage is increased to 290 kV
while maintaining the momentum spread.
Around 30 ms, the increase in the beam line density
due to bunch shortening turns the transverse emittances to increase in spite of the EC . At 33 ms, thebeam starts a transverse coherent oscillation with an
instantaneous current at the bunch center of 80 rnA.
It meets a transverse instability with increases inthe transverse-coherent-oscillation amplitude and the

312

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al

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-4

0

10

20

30

40

50

60

Time (ms)Fig. 1. Time evolution of the EC bunching of a 238U92+
ion beam of 4 rnA at 150 MeV lu.

transverse emittances, while the bunch shortening
stops at 45 ms. After 45 ms, the instantaneous current becomes about 120 rnA. Beam loss due to hitting
the chamber wall starts at 60 ms.
The transverse phase-space distribution of the unstable beam at 49 ms shown in Fig. 2 indicates thata dipole mode of transverse instability starts at thebunch center.
If we neglect the beam twist due to the toroid fieldI...... ". .' • . I! Jl".',,' '.. , ' Jl!u-±(.'
I_ fg0

.'
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l

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,,

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2

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0

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1
0

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-----*--~_+----~~------------~~--7 X
XI

o

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-3

-3

-4

-4

Fig. 2. Transverse phase-space distribution of the unstablebunched beam at 49 ms.

Fig. 3. Toroid structure idealized for calculation of the
field.

in the simulation, we obtain another result wherein
the beam is very stable and the transverse rms emittances remain about 3 x 10- 7 m x rad under the thirdharmonic RF voltage of 290 kV.
For the case where an EC device is aligned horizontally, the toroid section is shown in Fig. 3 where thetoroid structure is idealized for calculation of the field.
The horizontal field integrated along the s axis whichions experience in the toroid section is approximately
described bysider twist forces at both ends of the EC section. In
the current case, the emittance-increasing resonances
have half a resonance width tli of 0.01 near the operation point. Even if ions are trapped in the resonances,
they can not stay within the resonance widths because
the increases in the betatron amplitudes make the betatron tunes shift upwards. After the EC decreases
the amplitudes, the ions are trapped in the resonances
again. The repetition of the increases and decreases in
the amplitudes eventually produces the coherent oscillation and the instability described above when the instantaneous beam current is beyond a threshold which
depends on the strength of EC, the operation point,
and the beam energy.
Since the instability is not induced through any realpart of beam coupling impedance, it is not controlled
by adjusting the chromaticities; it can be cured using
a transverse feedback system.
In conclusion, we predict from the simulation analysis that the source of the transverse instability during
EC bunching is the toroid field that twists the beam.

Boxt(log Tt - log Xt) + BoX.
The first term expresses the effect of bending beams
vertically and the second term the effect of twisting thebeams. We can describe the thin-lens approximationof the twist force as a kicker of a delta function interms of a Fourier series of azimuthal functions. The
ion equation of motion due to the twist force is

2Eo = Ei

(i =I- 0),

where i is 0 or a positive integer. The equation meansthat there are an emittance-increasing resonance at
Vh + Vv = i and an emittance-beating resonance at
Vh - Vv = ±i. This holds true, as well, when we con-

References
1) Y. Yano et al.: Proc, PAC2001, ROPA007 (2001).
2) M. Takanaka: Proc. PAC2001, FPAH093 (2001); M.
Takanaka: RIKEN-AF-AC-29 (2001); M. Takanaka:
Proc. 13th Symp. on Accelerator Science and Technology (2001), p. 89.

313

RIKEN Accel. Prog. Rep. 35 (2002)

Design of highly-sensitive current monitor with HTS SQUID and
HTS magnetic shield
T. Watanabe, S. Watanabe , T. Ikeda, M. Kase, and T. Katayama
A high-temperature superconducting (HTS) magnetic shield based on Bi(Pb h -Sr2-Ca2-Cu3-0x (Bi2223) was fabricated by plasma spraying for the purpose of observing a somatosensory-evoked magnetic
field generated from the human brain. 1) Recently, aBi-2223 cylindrical magnetic shield was developed by
dip-coating on a 99.9% MgO ceramic substrate. A
highly-sensitive current monitor using this HTS magnetic shield in combination with a HTS Superconducting QUantum Interference Device (SQUID) is being
developed in the RIKEN RI beam factory for highaccuracy nondestructive measurement of faint beams
such as a radioisotope beam.
A DC current transformer (DCCT) based on thesecond-harmonic modulator-demodulator has beenused in a circular ring, the sensitivity of which isabout 1 f..LA. 2 ) In order to measure a beam intensity less than 0.1 f..LA, current transformers using theprinciple of a low temperature superconducting (LTS)
cryogenic current comparator (CCC) had been developed. 3,4 ) On the other hand, a prototype HTS CCC
with an HTS gradiometer SQUID has been successfully demonstrated as a means of nondestructive sensing of argon beams in the current range of 1- 20 J-lA. 5 )The HTS technology enables us to develop a systemequipped with a highly-sensitive current monitor withHTC SQUID and a HTS magnetic shield in the rangeof 1 nA- 10 f..LA.
The principle of superconductive CCC is based on
the property of the Meissner effect of superconducting
materials. A schematic drawing of the superconductive
CCC that we are designing is shown in Fig. 1 (a). The
MgO ceramic tube as a substrate of the HTS magnetic
shield is coated on both sides, inside and outside, witha thin HTS material. The sketch (Fig. 1 (b)) represents
the structure of the SQUID gradiometer and the magnetic core near the bridge. When the charged particle(ion or electron) beam is being passed along the axis ofa HTS tube, a shielding current produced by the Meissner effect flows in the opposite direction along the wallof the HTS tube so as to screen the magnetic field generated by the beam. Since the outer surface is designed
to have a bridge circuit (Fig. 1), the current generated by the charged particle beam concentrates on thebridge circuit and forms an azimuthal magnetic field <Paround the bridge circuit. Moreover, the HTS SQUID
is close to the bridge circuit and the HTS SQUID candetect the azimuthal magnetic field with a high S / N
ratio. In particular, since the SQUID gradiometer has
two pickup coils that are wound in opposite directions
and connected in series , the signellevel is expected to

314

Superconductive

Fig. 1. (a) Schematic drawing of the superconductive CCC
that we are designing. (b) Structure of the SQUID gradiometer and the magnetic core near the bridge.

Fig. 2. Characteristics of SQUID; (a) current (x-axis) VS.
voltage (y-axis) appears across the Josepson junctionsof HTS SQUID, (b) relationship of the magnetic field
B (x-axis) at the input coil with voltage (y-axis).

be improved by a factor 2, while an background noise
can then be greatly reduced. Furthermore, to obtaina higher coupling efficiency, we consider the possibilityof introducing the high-permeability magnetic core in
the HTS CCC.
Figure 2 shows the characteristics of HTS SQUID;(a) current (x-axis) VS. voltage (y-axis) appears across
the Josepson junctions of the HTS SQUID , (b) the relationship of the magnetic field B (x-axis) at the input
coil with voltage (y-axis). A flux-locked loop method isusually used in the HTS SQUID circuit because a wide
dynamic range and a high resolution of the flux sensitivity are required. Figure 3 shows the circuit diagramof the HTS SQUID and flux-locked loop. The magnetic flux density B induced by the charged particle

Pickup Coi I

H

Input

Feedback
Coi I

Fig. 3. Circuit diagram of a SQUID and flux-locked loop.

beam is transferred to the HTS SQUID with the aid of
the pickup coil and the input coil, which are built-in in
the HTS SQUID itself. The flux-locked loop can makea linear operation with respect to the HTS SQUID
circuit because it cancels the external magnetic flux
density B , with the aid of the bias current flowing in
the feedback coil as shown in Fig. 3. The voltage appearing in the resistance, if it appears in the figure, ismeasured in order to obtain the calibrated shield current, namely, the beam current passing through the
HTS tube.
The development of HTS CCC is currently inprogress. In particular, the examination of the HTS
magnetic shield coated on the l'v1g0 substrate is proceeding step by step. The critical current (Ie) and critical temperature (Te) of the Bi-2223 cylindrical HTS
shield should be confirmed to obtain a stable HTS
CCC. In order to confirm the Ie and Te, the DC fourprobe method has been examined using a small pieceof Bi-2223. X-ray diffraction analysis has been used to
identify the formation of the Bi-2223 phase. After theabove-mentioned tests, we intend to test the model ofthe HTS CCC. This is a combination of two cylindrical
HTS shields that are reinforced by a mu-metal shieldand HTS CCC. The diameters (D) are 148 mm and
98 mm, and the length (L) is 250 mm for both shields.
We are afraid that the unexpected external magnetic
field appeared on the associated measurement device.
The attenuation of the external magnetic field is calculated using the followin equation;

S= ~ = (-aL~2) ,exp

where S, B, Bo and a are the attenuation factor , theexternal magnetic field density, the attenuated magnetic field density measured at the center of the insideof the HTS shield and the shielding coefficient, respectively.
In order to measure the field distribution inside the
HTS magnetic shield and to obtain the attenuation factor S , we constructed the X-Y stage; which is moved
by four stepping motors in the X-V plane (Fig. 4).

Fig. 4. The X-Z stage which is moved by four stepping
motors in the X-Y plane. The X-Y stage is remotely
controlled by a personal computer (PC). The X-Y stage
is equipped with a Helmholtz coil, which can produce
a uniform magnetic field of 1 mT.

The X-Y stage is remotely controlled by a personal
computer (PC). The X-Y stage is equipped with aHelmholtz coil, which can produce a uniform magnetic
field of 1 mT. Furthermore, we have scheduled the following measurements in the domain of time and frequency:(1) Noise level and stability of the HTS SQUID system,(2) Signal level of HTS SQUID using a simulated
signal,(3) Noise level caused by trapped an environmental
magnetic field in the HTS SQUID.
We have a plan to construct a prototype of highlysensitive current monitor with a HTS SQUID and a
HTS magnetic shield aimed of measuring the beam
current in the beam transport line of the RIKEN Ring
Cyclotron (RRC) by the end of the fiscal year of 2001.
References
1) H. Ohta et al.: IEEE Trans. Appl. Supercond. 9 , 4073
(1999).
2) T. Watanabe, S. Watanabe, and A. Iatano: Proc. 6th
Symp. on Accelerator and Technology, Tokyo, 1987-10,(IONICS Publishing, 1987), p . 216.
3) A. Peters et al.: Proc. 5th European Particle Accelerator Conf., Barcelona, Spain, 1996-6, (Institute ofPhysics Publishing, 1996) , p. 1627.
4) T . Tanabe et al.: Proc. 6th European Particle Accelerator Conf., Stockholm, Sweden, 1998-6, (Institute ofPhysics Publishing, 1998), p. 1610.
5) L. Hao et al.: IEEE Trans. Appl. Supercond. 11 , 635(2001).

315

RIKEN Accel. Prog. Rep. 35 (2002)

Development of the kicker magnet for MUSES (II)T. Ohkawa,* Y. Chiba, M. Wakasugi, and T. Katayama
In the MUSES project, kicker magnets are used forion-beam injection and fast extraction. The injection
kicker field must fall from approximately 99% to 10%
of full strength and the extraction kicker field mustrise from approximately 10% to 99% of full strength
during the time interval between bunches. The highperformance of the kicker magnet is important for theefficiency of beam injection and extraction. In thispaper, the development of kicker magnets for MUSES
is presented.
We have designed , fabricated and tested the kicker
magnet and the power supply. 1) The design parameters of the kicker magnet are listed in Table 1. The
kicker magnet and the power supply are connected bya transmission cable. In order to minimize the loss inthe cable, the length of the cable should be as short as
possible. Thus, the length of the cable was set at 7 m.
A single-turn long search coil is used for the measurement of the magnetic field. Output voltages aremeasured with a high-voltage probe and digital oscilloscope. The waveform of the magnetic field is obtainedby integrating the induced voltage at the ends of thesearch coil. Here the effective length of the magnet isassumed to be 240 mm for the calculation.
Figure 1 shows the waveforms of induced voltage andmagnetic field in the core gap at 100 kV and Fig. 2
shows the waveform of magnetic field at the flat-top.
The rise time of the waveform is approximately 206 ns,
the flat-top (field stability is ±1 %) time is 774 ns. The
rise time of the field is longer than the design value(95 ns). This is due to the mismatch of impedance between the kicker magnet and feedthrough. Therefore,
matching capacitors were inserted between the kicker
magnet and feedthrough to improve matching. We use
a high-voltage probe in the measurement. When thisprobe tip is connected to the search coil, additional re-Table 1. Parameters of the kicker magnet.
ITEM

DESIGN VALUE

Gap heightGap width
Total core length
Cell number
Inductance of unit cell
Capacitance of unit cell
Characteristic impedance
Gap field
Coil current
PFN voltage
Field rise time

30mm
130mm
225mm

Mitsubishi Heavy Industries , Ltd .

316

90.136 J.LH
108.9 pF
250
0.084 T
2000 A
100kV
95 ns

>

3000

0.15 ,-,.

2000

0.10 :0-

~

if

0)

bl)

£3
"0
;>

\
0.05 lH~ 0.001\ l-0.05~
v
~

1000
0

"0
Q.)

.~

(1;[

d)

I:::

bl)
~

u

;:j

"0

I:::

-1000

rise

.

-2000
0

....

flat-top
1000

500

...
1500

-0.10
2000

Time (ns)Fig. 1. Magnetic field and induced voltage.

~

0.093

"0

0.092

lH

0.091

~

·15
Q.)

I:::

0.090

bl)
~

~ 0.089

0.088
0

500

1000

1500

2000

Time (ns)Fig. 2. Magnetic field at the fiat-top.

sistance, capacitance, and inductance are introduced
into the measurement circuit and this is expected toresult in a resonant circuit. This circuit causes parasitic ringing visible within the bandwidth of the oscilloscope. The error of the measurement with a highvoltage probe is too large to accurately estimate thefield stability. Therefore, to avoid the parasitic ringing, we have decided to use attenuators with a coaxial
structure whose characteristic impedance is 50 D instead of a high-voltage probe. Because the maximum
induced voltage at the ends of the search coil is larger
than the allowable input voltage of the attenuator, wechange the width of the search coil from 5 mm to 2 mmin order to reduce it. In order to improve the signal tonoise ratio of the measured voltage, two signals measured by switching the polarity of the search coil are
averaged upon changing the sign.
Figures 3 and 4 show the improved waveforms at
100 kV. The optimum values of the capacitance are
122 pF at the inlet and 295 pF at the outlet of the
kicker magnet. The rise time of the waveform is approximately 83 ns , while the flat-top time is 888 ns.
These results satisfy the specifications.

0.10

800

i~

>
<I)

400

JI

OJ)

~

"0
;>

1\

1

--------------

0

....

"'d
11)
C,)

~

1\ f

::s -400

"'d

rise

..5

...

....

"'d
Q)

lH

0.00

.~

d)
;:::::
OJ)

ro-0.05 ~

IVflat-top

0.05

r-

0.1

r"'d
Q)

lH
.~

"0
;:::::

OJ)

ro
~

po

-0.10

-800
500

0

1000

1500

.....0

0.08

J ~

0.06

./

0.04
0.02
0

o

2000

.,.-

20

40

60

80

100

Voltage of the power supply (k V)Time (ns)Fig. 3. Magnetic field and induced voltage with the capacitors.

r- 0.08~\:--------1~ 0.087 t--t
" ~-- -l-~-o----*I~-----,J-7-~-----=----::..... --=---- --".,---- -.....
.~

0.086

___________________ .. ______________ _ _________.. _._~ . ___ _;:::::
OJ)~ 0.085

0.084

o

500

1000 1500
Time (ns)2000

Fig. 4. Magnetic field at the flat-top with the capacitors.

Fig. 5. Dependence of the magnetic field strength on thevoltage of the power supply.

We have also measured the absolute value of themagnetic field with a short search coil. The result of
the measurement shows that the effective length of thelong search coil is 242 mm. The dependence of themagnetic field at the fiat-top on the voltage of thepower supply is shown in Fig. 5. The measurement
is in good agreement with the calculation within ±1 %.
We intend to perform further tests to study the field
distri bu tion.
References
1) T. Ohkawa et al.: Proc. EPA2000 , Vienna, Austria,
2000-6 (The European Physical Society Interdivisional
Group on Accelerators, 2000) , p. 2113.

317

VI. RADIATION MONITORINGRIKEN Accel. Prog. Rep . 35 (2002)

Routine work for radiation safety In the Ring Cyclotron Facility
Y. Uwamino, S. Fujita, S. Ito, H. Sakamoto, *l N. Hirao,*2 T. Nakamura,*2 and M. Kase
We report here on the residual radioactivity andleakage 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 after almost every beam experiment as well as during the routine overhaul period. The routine overhaul started immediately
after the experiment which was carried out with thelOB beam of 7.8 MeV /nucleon in the E7 experimental vault from Aug. 6 to 11, 200l. The dose rates att he deflectors in the inj ector AVF cyclotron and theRing Cyclotron were found to be 0.85 mSv /h on Aug.
22,2001 and 14mSv/h on Aug. 24, 2001, respectively,
during the overhaul period.
In addition to the above routine measurement , dose
rates inside the inj ector AVF cyclotron were measured
when its acceleration chamber was opened on Mar.
13, 2001 because of an insulation failure of the deflector. The dose rate at the AVF cyclotron deflector was
l.3 mSv /h . The Ring Cyclotron was opened as well on
Jun. 1, 2001 for the same reason and the dose rate at

the Ring Cyclotron deflector was 30 mSv /h.
During the period from Oct. 1, 2000 to Sept. 30,
2001, dose rates were measured along the beam lines.
The spots a -y, marked by bullets in Fig. 1, are theplaces where the dose rates exceeded 10 p,Sv /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 3.5 mSv /h(3500 p,Sv /h) at the target chambers in the E3 and t heE4 experimental vaults denoted by u and y in Fig. 1,
respectively. Whenever we observed a high dose rate,
we roped off the area and posted a sign warning that it
was dangerous to remain for a long time in that place.
We also continuously monitor the leakage radiationfrom the Ring Cyclotron Facility.
Having analyzed the collected data of leakage neutrons, we found that the radiation levels in the controlled area were much lower than the allowable dose
limit. The leakage of I'-rays and neutrons was below
the detection limit of the environmental monitors. We
evaluated the radiation level at the boundary of the accelerator facility using the monitor which was installed

Fig. 1. Layout of the RIKEN Ring Cyclotron Facility as of 2001. Measured locations of residual radioactivities along the beam lines are shown by bullets a - yo
*1

*2

SRI Accelerator Service, Ltd.
Faculty of Science, Tokyo University of Science319

Table 1. Summary of the dose rates measured along the beam lines with ionization-chamber survey
meters. The detection points a- y indicate the measured locations shown in Fig. 1.
Detection
point
a

b
c
d
e
f
g

h
j
k
I
m
n
0

P
q
r

s
t

u
v

w
x
y

Measured dose rate(/LSv Ih)
60
90
35
45
650
500
500
55
250
200
250
1400
2000
80
30
25
17
35
19
70
3500
3200
120
150
3500

Date

Particle

Apr 2, '01
Dec 18, '00
Dec 18, '00
Dec 18, '00
Apr 20, '01
Dec 18, '00
Aug 6, '01
Dec 18, '00
Aug 6, '01
Jun 13, '01
Nov 14, '00
Nov 14, '00
Dec 18, '00
Jun 13, '01
Apr 25, '01
Aug 6, '01
Dec 18, '00
Jul 11, '01
Feb 15, '01
Aug 6, '01
Aug 6, '01
Aug 6, '01
Jun 8, '01
Dec 12, '00
Dec 12, '00

Fe-56
C-12
C-12
C-12
p
C-12
N-14
C-12
N-14
p
Ar-40
Ar-40
C-12
p
C-12
N-14
C-12
0-18

in the computer room on the ground floor immediately
above a bending magnet which guided the beams fromthe ring cyclotron vault to the distribution corridor. As

320

P

N-14
N-14
N-14
d
d
d

Energy(MeV lu)
90
117
117
117
210
117
135
117
135
210
95
95
117
210
135
135
117
70
150
135
135
135
140
270
270

Intensity
(enA)
1
1
1
1
10
1
800
1
800
100
1200
1200
1
100
1000
800
1
1350
1
800
800
800
100
70
70

P eriod(days)
3
1
1
1
1
1
5
1
5
3
1
1
1
3
1
5
1
1
1
5
5
5
2
1
1

a result , we obtained a radiation level of approximately
5 p,Sv /year which was much lower than the allowable
dose limit (1 mSv /year).

RIKEN Accel. Prog. Rep . 35 (2002)

Shielding calculation for the CSM installation at RILAC
Y. Uwamino, S. Ito, S. Fujita, and N. Fukunishi
The Charge State Multiplier (CSM) was installed
after the RIKEN Linear Accelerator (RILAC), andthe maximum energy was nominally upgraded to
6.5 MeV /nucleon for all elements. Since the buildingof RILAC had been designed to meet the maximum
energy of 4 MeV/nucleon, some local shielding became
necessary. Here we briefly report the shielding calculations and their results.
Shin et al. 1 ) measured the thick-target neutron yieldfor charged particles, and the results were fitt ed byusing the moving-source model. The fitted data of
6.25-MeV /nucleon 12C beam bombardment on copper
are given in their paper, 1) and the spectra are shownin Fig. 1. The ANISN 2) transport code was used forshielding calculations, along with their source data andthe HIL086R group constants.3 )The results for the 90-deg bending magnet, whose
yoke is made of 17-cm-thick iron, are shown in Fig. 2.
The calculation geometry is a multilayer slab (17-cmthick iron and 183-cm-thick ordinary concrete) which
is normally irradiated by the neutrons of Fig. 1. The
ordinate is r2 H , where r [cm] is the distance from theloss point and H [Sv /h] is the dose rate due to theneutrons and the secondary gammas. Calculations ofsimilar geometries with 30-cm-thick iron and without
iron were also performed , and the attenuation curvesin the concrete part were fitted by the following exponential formula:~....en
I

.;.

0>

:IE

,-,

c

e

",
...

+-'

10-7

....

.,

',~

-..

..." ..'., .. .......-.
..

II.

':-, ... ., ........

,'..

~

O. deg45. deg
90 . deg
135. deg180. deg

+-'
C

~

10-8

"
~

..c
:::l

0

"

>

10 2

~
+-'

c

0>

10 1

a!

>

:::l

00>

10°

0>

en

0
1
" 10-

10-2
10-3 l.......J.---,---,---,--1--'---'---'--.L..-l.......J.--L-'---'---'--'--'---'---'---'

o

50

100
depth (em)

150

10-9
0

5

200

Fig. 2. Dose equivalent distribution in a 17-cm-thick-iron+183-cm-thick-ordinary-concrete slab. The irradiating
neutrons are produced by 6.25-MeV / nucleon 12C beam
bombardment on copper .

(1)

where x [cm] is the shield thickness including the ironslab, and A [cm] is the attenuation length. The Hovalues can be fitted by the following formula:(2)

Table 1. A, A and B values in Eqs. (1) and (2) for 6.5MeV / nucleon 10-pp,A 12C beam.

..

>-

0>

Q
~

.........

"'-..::....'.,.......
'''', ..
-.
'~: '., .......
':..... , .....

" 10-6
a;

'r
'r

103
"'E

':..... .... .'. .....a.
. ':....
..
-......
" ....
..

., ....

':~.. II, .......

SC- - Fe- 17em,0-deg......... Fe-17em, 45-deg._ . - Fe-17em,90-deg------ Fe-17em,135-deg- - - - - Fe-17em, 180-deg

where A and B are t he fitting parameters, and they
are listed in Table 1 with the attenuation lengths .
The additional local shield is necessary for the 90deg bending magnet and the GARIS magnet . The
effect of the polyethylene local shield for the 90-deg
magnet is shown in F ig. 3, that is , 10-cm- to 70-cmthick polyethylene shields are inserted behind the 17cm iron slab. Polyethylene is an efficient moderator forneutrons making the thermal neutron flux high, but almost ineffective for capture gammas. The penetrativeiron-capture gammas of 7.6 MeV raise the dose ratein the concrete part particularly in the case of thick-::::.:.....
..... , .....

10-5

:>

:::l
0>

104

Ho = Aexp(BcosB),

10-4
I

10 5

10
neutron energy (MeV)" ".. ....
" ".. ....
" ".. ......
" " ....
" ..

15

20

Fig. 1. Neutron spectra of 6.25-MeV /nucleon 12C beam
bombardment on a full-stop copper target .

iron slab thickness
A [cm]A [Sv/ h cm 2 ]

B

Ocm
0.079
25800
0.619

17cm
0.079
8200
0.660

30cm
0.077
5720
0.592

321

10 5

polyethylene. It was on the basis of these data thatthe local shielding at RILAC was designed.

10 4--poly=Ocm......... poly=10cm. - . - pol y=20cm- - - - - pol y=30cm--- _.. pol y=40cm. '-- poly=50cm- - pO 1y=60cm- poly=70cm

103
"'E
(;)

.c
>

102

.f-I

10 1

.........

References
1) K. Shin et al.: Nucl. Sci. Eng. 120, 40 (1995).
2) W. W. Engle, Jr.: K-1963, Oak Ridge Gaseous Diffusion
Plant, Oak Ridge (1967).
3) H. Kotegawa et al.: JAERI-M 93-020 (1993).

~

c:
el>

co

>

:::J

0el>

10°

el>

III

0

"'C

10-1
10-2
10-3
0

100
150
50
depth (em), including Fe and polyethylene

200

Fig. 3. Dose equivalent distribution in a 17-cm-thickiron+polyethylene+ordinary-concrete slab. The irradiating neutrons are produced by 6.25-MeV /nucleon 12C
beam bombardment on copper.

322

RIKEN Accel. Prog. Rep. 35 (2002)

Improvement of radiation safety system for RIKEN Ring Cyclotron
Y. Uwamino, S. Fujita, S. Ito, H. Sakamoto,*l N. Hirao ,*2 T. Nakamura,*l and M. Kase
The first radiation safety system for the Nishina
Building which started operation in 1986 was replaced by the second network dispersed system 1 ) in
1999. Now the RI Beam Factory (RIBF) project isin progress and its accelerator building is under construction next to the Nishina Building. As a part of
the RIBF project, a charge state multiplier was installed at the RIKEN Linear Accelerator (RILAC),
and the maximum energy was upgraded to approximately 6 Me V /nucleon. Experiments on radioisotope
production can be performed with this upgraded beam.
At the same time, the classification of the radiation controlled area in the RILAC facility has beenchanged from 2nd grade (contamination free) to 1st
grade (contamination possible). To compensate forthese changes, the radiation safety system was upgraded as follows.
(1) Installation of a third hand-foot-clothes monitor at
the Nishina Building
Because the RIBF accelerator facility will be accessed through the Nishina Building for the time being,a new hand-foot-clothes monitor, which can be seen on
the extreme right in Fig. 1, was installed in the Nishina
contamination control room. Three hand-foot-clothes
monitors are presently connected to the host computer,and the box-type monitor seen in the middle of Fig. 1
is a spare unit. Another monitor will be installed in the
future to cope with the expected increase of workers
accessing the facilities.
(2) Expansion of the radiation monitoring system tocover all of the facilities including RILAC
The radiation monitoring system, which forms a partof the Nishina Building's radiation safety system, consists of a central supervisory console and radiation
monitors. This monitoring system was recently expanded to cover a larger area including RILAC, with
the installation of new neutron and gamma-ray monitor sets (4 sets for RILAC and 8 sets for the Nishina
Building). Most sets are of the conventional stationary type, but several sets are of the movable-head type,shown in Fig. 2 (the round case on the left is the movable detector head that is connected to the controller- the box on the right - with a 20-m-Iong cable). Allof the monitors are connected to the radiation safetysystem of the Nishina Building, and the data can also
be accessed from the RILAC control room.
(3) Improvement of the access control system at the
RILAC facility
With the classification of the RILAC radiation control area being changed to 1st grade, the access control at the contamination control room was tightened.
Two hand-foot-clothes monitors were introduced, theprevious door was replaced by an automatic one with
an electric locking system, and a barcode reader was
installed so that workers entering or leaving the facility
could be identified from their dosimeter barcodes. The
automatic door and the barcode reader are shown in
Fig. 3. A central supervisory console that is describedin the next section controls these instruments.
(4) Installation of a central supervisory console at
RILAC
A central supervisory console for the radiation safetysystem was installed in the RILAC control room tocentralize all of the data from the radiation monitors,
the entry and exit control system and the interlock control system. Because this console is connected to all

Fig. 1. The hand-foot-clothes monitors installed in the contamination test room of the Nishina Building.
*1*2

SRI Accelerator Service, Ltd.
Faculty of Science, Tokyo University of ScienceFig. 2. The movable-head type radiation monitor in the
2nd basement corridor of the Nishina Building.

323

of the radiation monitors, the hand-foot-clothes monitors, the automatic door and the barcode reader at
RILAC , it allows us to access and monitor all data concerning radiation levels and workers entering or leaving
the controlled area. The same data can be accessed in
the Radiation Safety Office of the Nishina Building.
References
1) S. Fujita, S. Nakajima, S. Ito, H. Sakamoto, A.
Fujiwara, A. Uchiyama, M. Kase , and Y. Uwamino:
RIKEN Accel. Prog. Rep. 33, 265 (2000).

Fig. 3. The automatic door and the barcode reader in the
RILAC contamination test room. The door on the left
with a glass window is the automatic door , and thebarcode reader is to the left of the door.

324

VII. LIST OF PUBLICATIONS
1.

Accelerator
physics

development

andaccelerator

T. Tanabe, T. Rizawa, K. Ohtomo, T. Katayama,
A. Yamashita, E. Syresin, and 1. Meshkov: "Design of an electron cooling device for the Accumulator Cooler Ring in MUSES proj ect", Nucl. Instrum.
Methods Phys . Res. A 441 , 104- 109 (2000).
T. Tominaka: "Two-dimensional magnetic fields ofpolygonal conductors", Nucl. Instrum. Methods
Phys. Res . A 458 , 619- 626 (2001).
T. Nunomiya, N. Nakao, P. Wright, S. Nakamura,E . Kim ,' T. Kurosawa, S. Taniguchi, M. Sasaki, H.
Iwase, Y. Uwamino, T. Shibata, S. Ito, and D. Perry:"Measurement of deep penetration of neutrons produced by 800-MeV proton beam through concrete
and iron at ISIS", N ucl. Instrum. Methods Phys.
Res. B 179,89- 102 (2001).
Y. Yano, A. Goto, M. Kase, and T . Katayama:"Progress report of RIKEN RI Beam Factory",
Proc. 13th Symp. on Accelerator Science and Technology, Suita, 2001- 10, RCNP, Osaka University,
Osaka, pp. 20- 24 (2001) .
O. Kamigaito , N. Sakamoto, M. Kase, E . Ikezawa,
S. Kohara, Y. Miyazawa, T. Chiba, M. Hemmi ,Y. Chiba, A. Goto , and Y. Yano: "Rf cavities of the RIKEN charge-state multiplier", Proc.
13th Symp. on Accelerator Science and Technology,
Osaka, 2001- 10, RCNP, Osaka University, Osaka,
pp. 229- 231 (2001).
H. Akiyoshi, T. Chiba, H. Hasebe, M. Kase, and Y.
Yano: "Liquid film stripper for RIKEN RI Beam
Factory", Proc. 13th Symp. on Accelerator Scienceand Technology, Suit a , 2001- 10, RCNP, Osaka University, Osaka, pp. 331- 333 (2001).
Y. Yano, T. Katayama, A. Goto, and M. Kase:"RIKEN RI Beam Factory Project", Proc. 16th Int.
Conf. on Application of Accelerators in Researchand Industry, Texas, USA, 2000- 11 , edited by J. L.
Duggan and 1. L. Morgan, AlP, New York, pp. 679682 (2001).
O. Kamigaito, M. Kase, E. Ikezawa, M. Fujimaki, S.
Kohara, N. Fukunishi, N. Sakamoto, M. Hemmi, Y.
Miyazawa, Y. Chiba, T. Chiba, A. Goto, and Y.
Yano: "Upgrade of RIKEN heavy-ion linac for nuclear physics experiments", Proc. 26th Linear Accelerator Meet. in Japan, Tsukuba, 2001- 8, KEK ,Tsukuba, pp. 43- 45 (2001).
2.

Nuclear physics and nuclear instrumentation

H. Izumi, K. Asahi , H. Ueno, H. Okuno , H. Sato, K.
Nagata, Y . Hori, M. Adachi, N. Aoi, A. Yoshida,
G. Liu , N. Fukunishi, and M. Ishihara: "Electric
quadrupole moments of neutron-rich nuclei 14B and

15B", Phys. Lett. B 366, 51- 55 (1996).
Y. Mizoi, T. Miyachi, Y. Matsuyama, T. Fukuda,
Y. Watanabe, N. Fukuda, N. Aoi, M. Notani, Y.
Watanabe, A. Yoshida, and H. Sakurai: "Study ofthe bf 8Li( a,n)b f 11 B reaction by using new MUSIC
detector", Inst. Nucl. Study, Univ. Tokyo, Ann.
Rept. 1996, 36- 37 (1997).
T. Kishida: "RI Beam Factory Project at RIKEN" ,Proc. 3rd Japan-Italy Joint Symp. '97 on Perspectives in Heavy Ion Physics , Padova, Italy, 1997- 10,edited by C. Signorini, F. Soramel, and T. Kishida,
World Scientific, Singapore, pp. 274- 281 (1997).
T. Suzuki and T. Otsuka: "Effects of halo on the
Coulomb displacement energy of the isobaric analog state of 11 Li", Nucl. Phys. A 635 , 86- 96 (1998).
K. Asahi, A. Yoshimi, K. Sakai, H. Ogawa, T. Suzuki,
and M. N agakura: "Fundamental physics with polarized nuclear spins: Spin maser for the neutron
EDM measurements", Czech. J. Phys. 50, Suppl. 1,
pp. 176-186 (2000).
T. Kurosawa, N. Nakao, T. Nakamura, H. Iwase ,H. Sato, Y. Uwamino, and A. Fukumura: "Neutron yields from thick C, AI, Cu, and Pb targets bombarded by 400 MeV /nucleon Ar, Fe, Xe
and 800 MeV /nucleon Si ions", Phys. Rev. C 62 ,044615-1- 044615-11 (2000).
H. Kurasawa and T. Suzuki: "Role of the Dirac sea
in relativistic nuclear models", Soryushiron Kenkyu
102, A110- A115 (2000).
T. Fujita, K. Sagara, K. Shigenaga, K. Tsuruta, T.
Yagita, T. Nakashima, N. Nishimori , H. Nakamura,and H. Akiyoshi: "Difference between nd Ay and pd
Ay below 16 MeV", AlP Conf. Proc. 570, 709- 713(2001).
K. Sekiguchi, H. Sakai, H. Okamura, N. Sakamoto, A.
Tamii, T. Uesaka, T. Wakasa, Y. Sato, T. Ohnishi,
K . Yakou, K. Suda, S. Sakoda, H. Kato, Y. Maeda,
M. Hatano, and J. Nishikawa: "Measurement ofcross section and analyzing powers for dp scattering at intermediate energies and three-nucleon force
effect", AlP Conf. Proc. 570, 714- 718 (2001).
Y. Mochizuki and T. Izuyama: "New phase of theories
for pulsar glitches: Relation between nuclear structure and superfluidity inside neutron stars", J. Phys.
Soc. Jpn. 56, 316- 325 (2001).
T. Kato, T. Doke, J. Kikuchi, F. Nishikido, H. Okada,
1. Tanihata, and K. Morimoto: "Time and energy
responses of liquid-xenon scintillation chamber for
20Ne ion beam at 135A MeV", Jpn. J. Appl. Phys.
40 , 3377- 3381 (2001) .
N. Nakao, T. Kurosawa, S. Nakamura, and Y.
Uwamino: "Absolute measurements of the response
function of an NE213 organic liquid scintillator forthe neutron energy range up to 206 MeV", Nucl. Instrum. Methods Phys. Res. A 463 , 275- 287 (2001).

325

M. Takada, S. Taniguchi, S. Nakamura, N. Nakao , Y.
Uwamino, T. Shibata, and K. Fujitaka: "Neutron
spectrometry in a mixed field of neutrons and protons with a phoswich neutron detector: Part 1: response functions for photons and neutrons of thephoswich neutron det ector", Nucl. Instrum. Methods Phys. Res. A 465 , 498- 511 (2001).
H. Kumagai , A. Ozawa, N. Fukuda, K. Summerer, and
I. Tanihata: "Delay-line PPAC for high-energy lightions", Nucl. Instrum. Methods Phys. Res. A 470 ,
562- 570 (2001).
K. Yasuda, T. Hotta, M. Kato , M. Kawabata, Y.
Maeda, N. Matsuoka, T. Matsuzuka, Y. Mizuno ,M. Nomachi, T. Noro, Y. Sugaya, K. Takahisa, K.
Tamura, H. Yoshida, M. Yoshimura, Y. Yokota,
Y. Yuasa, K. Imai, T. Murakami , J. Murata, I.
Nakagawa, T. Tamae, H. Tsubota, and H. Akiyoshi:"Measurement of proton-proton bremsstrahlung at
389 MeV", Nucl. Phys. A 684, 400- 402 (2001).
K. Sekiguchi, H. Sakai, H. Okamura, N. Sakamoto, A.
Tamii, T. Uesaka, Y. Sato, T. Ohnishi, T. Wakasa,
K. Yakou, K. Suda, S. Sakoda, H. Kato, Y. Maeda,
M. Hatano , and J. Nishikawa: "Measurement ofcross sections and analyzing powers for the d-p elastic scattering at intermediate energies", N ucl. Phys.
A 684, 574c- 576c (2001).
N. Dinh Dang: "Description of single- and multiplephonon giant dipole resonances within the phonon
damping model", Nucl. Phys. A 687, 253c- 261c
(2001).
Y. Mochizuki: ,,44 Ti: its initial abundance in Cas
A and its detection possibility in SN 1987 A withINTEGRAL" , Nucl. Phys. A 688, 58c- 61c (2001).
T. Yamazaki: "Strangeness nuclear physics toward
the new millennium: A personal summary of
HYP2000" , Nucl. Phys. A 691 , 515c- 530c (2001).
A. Ozawa, T. Suzuki, and 1. Tanihata: "Nuclear
size and related topics", Nucl. Phys. A 693 , 32- 62(2001).
T. Kato: "The response of scintillation light producedby heavy ion beams in liquid xenon and its application to particle identification", Nucl. Study 46,
No.3, pp. 51- 59 (2001).
K. Yoneda, H. Sakurai, T. Gomi , T. Motobayashi,
N. Aoi, N. Fukuda, U. Futakami, Z. Gacsi , Y.
Higurashi , N. Imai, N. Iwasa, H. Iwasaki, T. Kubo ,M. Kunibu , M. Kurokawa, Z. Liu, T. Minemura,
A. Saito, M. Serata, S. Shimoura, S. Takeuchi , Y.
Watanabe , K. Yamada, Y. Yanagisawa, K. Yogo ,A. Yoshida, and M. Ishihara: "Deformation of
34Mg studied via in-beam , -ray spectroscopy using radioactive-ion projectile fragmentation", Phys.
Lett. B 499, 233- 237 (2001).
A. Toyoda, K. Ishida, K. Shimomura, Y. Matsuda,
W. Higemoto, S. Nakamura, T. Matsuzaki, and K.
Nagamine: "Measurements of an ortho-para effectin muon-catalyzed fusion in solid deuterium", Phys.

326

Lett. B 509, 30-36 (2001).
P. Kienle and T. Yamazaki: "Empirical deduction ofa medium-modified quark condensate from Is 7[states in heavy nuclei", Phys. Lett. B 514, 1- 6
(2001).
A. Ansari , N. Dinh Dang, and A. Arima: "Thermal
shape and orientation fluctuation corrections for the
hot giant dipole resonance within the static path approximation" , Phys. Rev. C 63 , 024310-1- 024310-5(2001) .
N. Dinh Dang, V. Kim Au , T. Suzuki, and A.
Arima: "Pygmy and giant dipole resonances inneutron-rich nuclei within quasiparticle representation of phonon damping model" , Phys. Rev. C 63 ,
044302-1- 044302-10 (2001).
H. Akiyoshi, K. Sagara, S. Ueno, N. Nishimori , T.
Fujita, K. Maeda, H. Nakamura, and T. Nakashima:"Measurement of analyzing powers of the 1 (d ,3He),
reaction at 17.5MeV", Phys. Rev. C 64, 034001-1034001-6 (2001).
A. Arima and N. Dinh Dang: "Phonon damping
model using random-phase-approximation operators", Phys. Rev. C 64 , 024302-1- 024302-4 (2001).
H. Sato, T. Kurosawa, H. Iwase, S. Nakamura, Y.
Uwamino, and N. Nakao: "Measurements of double differential neutron production cross sections by
135 MeV/nucleon He, C, Ne and 95 MeV /nucleon Ar
ions", Phys. Rev. C 64 , 034607-1- 034607-12 (2001).
T. Suzuki, N. Dinh Dang, and A. Arima: "Descriptionof the Gamow-Teller resonance within the phonon
damping model", Phys. Rev. C 64 , 027303-1027303-3 (2001).
A. Krasnitz, Y. Nara, and R. Venugopalan: "Coherent gluon production in very-high-energy heavy-ion
collisions", Phys. Rev. Lett. 87, 192302-1- 192302-4(2001).
K. !ida, G. Watanabe, and K. Sato : "Formation of
nuclear "Pasta" in cold neutron star matter", Prog.
Theor. Phys. 106, 551- 559 (2001).
K. Asahi, H. Ogawa, H. Ueno, D. Kameda, H.
Miyoshi, Y. Kobayashi , A. Yoshimi , K. Yogo, A.
Goto, T. Suga, K. Sakai, N. Imai, Y. Watanabe,
K. Yoneda, N. Fukuda, N. Aoi , A. Yoshida, T.
Kubo, M. Ishihara, W. Schmidt-Ott, G. Neyens , and
S. Teughels: "Quadrupole moments and magnetic
moments in exotic nuclei" , RIKEN Rev. No . 39 ,pp. 142- 147 (2001) .
A. Kohama, R. Seki , A. Arima, and S. Yamaji: "Feasibility of determining surface of matter density dist ributions of nuclei at RIBF", RIKEN Rev. No. 39,
pp. 155- 160 (2001).
3.

Atomic and solid-state physics

M. Takekawa and Y. Itikawa: "Theoretical study ofelectron collision by OCS molecule: elastic process" ,At. Collision Res. Jpn. No . 26 , pp. 12- 13 (2000).

D. Murakoshi, N. Okabayashi, Y. Iwai, H. Torii, Y.
Morishita, K. Nishio, H. Masuda, K. Komaki, andY. Yamazaki: "Charge state and scattering angle measurements of 800 eV I q Xe q+ ions transmitted through Ni-microcapillaries for multiple electron transfer study" , At. Collision Res. Jpn. No. 26,
pp. 14-15 (2000).
M. Hoshino, M. Kitajima, H. Tanaka, Y. Nakai, Y.
Kanai, and Y. Yamazaki: "Angular distribution
measurements of double electron capture processes
in very slow C4 + -He collision", At. Collision Res.
Jpn. No. 26, pp. 32- 33 (2000).
A. Itoh, T. Majima, H. Tsuchida, Y. Nakai, and T.
Kambara: "Anomalous q-dependence of fragment
ions from C60 bombarded by 30 Me V Neq + ions" ,At. Collision Res. Jpn. No. 26, p. 44 (2000).
Y. Iwai, S. Thuriez, Y. Kanai, H. Oyama, K. Ando, R.
Hutton, H. Masuda, K. Nishio, K. Komaki, and Y.
Yamazaki: "High-resolution soft X-ray spectroscopyof 2.3 keY lu Ne 9 + ions through Ni microcapillarytarget", At. Collision Res. Jpn. No. 26, pp. 50- 51(2000).
T. Ikeda, Y. Iwai, T. Oku, C. Otani, H. Kato, K.
Kawai, H. Sato, H. Shimizu, Y. Takizawa, Y. Nakai ,H. Miyasaka, Y. Morishita, H. Watanabe, and Y.
Yamazaki: "X-ray spectroscopy of highly charged
ions using superconducting tunnel junctions" , At.
Collision Res. Jpn. No. 26, pp. 62- 63 (2000).
D. Dumitriu, Y. Kanai, Y. Iwai, Y. Morishita, H.
Oyama, and Y. Yamazaki: "Charge state distribution of highly charged ions passing through microcapillaries", At. Collision Res. Jpn. No. 26, pp. 64- 65(2000).
T. Kambara, Y. Kanai , T. Kojima, Y. Nakai, A.
Yoneda, Y. Yamazaki, and K. Kageyama: "Shortultrasonic pulse from fast heavy-ion impact on metals", At. Collision Res. Jpn. No . 26, pp. 103- 105(2000).
M. Wada, 1. Katayama, S. Okada, Y. Ishida, T.
Nakamura, T. Sonoda, T. Oshima, Y. Nakai, T.
Kojima, Y . Kanai, T. Kambara, Y. Yamazaki ,A. Yoshida, T. Kubo, K. Okada, K. Noda, H.
Kawakami, and S. Ohtani: "RF ion-guide system
for trapping energetic radioactive nuclear ions", At.
Collision Res. Jpn. No. 26, pp. 106- 108 (2000).
N. Oshima, T. Kojima, D. Dumitriu, A. Mohri, H.
Oyama, T. Kambara, Y. Kanai, Y. Nakai, M. Wada,and Y. Yamazaki: "Development of a slow-positronsource" , At. Collision Res. Jpn. No. 26, pp. 109- 110(2000).
E. Vagi: "The study on the state of hydrogen dissolved
in metals by means of the channeling method", Corros. Eng. 49 , 417-426 (2000).
Y. Kobayashi, Y. Yoshida, A. Yoshida, Y. Watanabe,
K. Hayakawa, K. Yukihira, F. Shimura, and F.
Ambe: "In-beam M6ssbauer study of 5 7 Mn/ 57 Fe in
Si following projectile fragmentation and implanta-tion", Hyperfine Interact. 126, 417- 420 (2000).
T. Maruyama, H. Yamada, T. Mochizuki, K. Akimoto,and E. Vagi: "Quenching mechanism of luminescence in Sm-doped ZnS", J. Cryst. Growth 214/
215 , 954- 957 (2000).
N. Kuroda, N. Ishikawa, Y. Chimi, A. Iwase, S.
Okayasu, H. Ikeda, R. Yoshizaki, and T. Kambara:"Effect of damage morphology on the pinning andvortex dynamics in Bi2Sr2CaCu208+8 irradiatedwith GeV heavy ions" , Physica B 284/288 , 847848 (2000).
H. Ikeda, N. Kuroda, T. Kambara, K. Yoshikawa,and R. Yoshizaki: "Heavy-ion irradiation effects in
Ag-Cu alloy sheathed Bi-2223 tapes", Physica B
284/288 , 871- 872 (2000).
T. Kambara, Y. Kanai, T. Kojima, Y. Nakai, A.
Yoneda, Y. Yamazaki, and K. Kageyama: "Ultrasonic pulse from fast heavy-ion irradiation on
solids", 16th Int. Conf. on Application of Accelerators in Research and Industry, Denton, USA , 200011, edited by J. L. Duggan and 1. L. Morgan, American Institute of Physics, New York, pp. 1040- 1043
(2001).
C. Zhu, Y. Teranishi, and H. Nakamura: "Nonadiabatic transitions due to curve crossings: Complete
solutions of the landau-zener-stueckelberg problems
and their applications", Adv. Chern. Phys. 117,
127- 233 (2001).
Y. Teranishi, K. Nagaya, and H. Nakamura: "Newway of controlling molecular processes by lasers",
Advances in Multi-Photon Processes and Spectroscopy, Honolulu, USA, 1999- 12, edited by R. J.
Gordon and Y. Fujimura, World Scientific, Singapore, pp. 215- 227 (2001) .
F. Saito, Y. Nagashima, T. Kurihara, N. Suzuki, J.
Kim, 1. Wei, Y. Ito, A. Goto , and T. Hyoudo: "Recovery of 18F from [180] water by electrochemical
method", Appl. Radiat. Isot. 55 , 755- 758 (2001).
T. Nakatsukasa and K. Yabana: "Photoabsorption
spectra in the continuum of molecules and atomic
clusters", J. Chern. Phys. 114,2550-2561 (2001).
S. Kitazawa, H. Ida, N. Matsui, T. Takayanagi, K.
Wakiya, K. Iemura, S. Ohtani, H. Suzuki, Y. Kanai,
and U. Safronova: "Electron spectra from singlet
and triplet states of Ne 6 +** produced by low energy
Ne 8+ + He, Ne and Ar collisions", J. Phys. B 34,
3205- 3220 (2001).
L. Wei, N. Suzuki, J. Kim , F. Saito, Y. Ito, A. Goto,
T. Kurihara, Y. Nagashima, and T. Hyoudo: "Slowpositron yields from some porous materials", Mater.
Sci. Forum 363/365 , 643- 645 (2001).
F. Saito, N. Suzuki, J. Kim, 1. Wei , Y. Ito, A. Goto ,T. Kurihara, Y. Nagashima, and T. Hyoudo: ,, 18 F
source for a slow positron beam" , Mater. Sci. Forum
363/365 , 679- 681 (2001).
M. Hasegawa and E. Vagi: "Positron annihilation andion channelling methods", Met. Technol. 71, 962-

327

967 (2001).
F. Saito, T. Hyoudo , Y. Nagashima, T. Kurihara, N.
Suzuki, Y . Ito, and A. Goto: "Intense radioisotope
sources for spin polarized positron beams" , New
Directions in Antimatter Chemistry and Physics,
edited by C. M. Surko and F. A. Gianturco, Kluwer
Academic Publishers, Amsterdam, pp. 35- 45 (2001).
M. Tachikawa, 1. Shimamura, R. Buenker, and M.
Kimura: "Bound states of positron with molecules" ,New Directions in Antimatter Chemistry andPhysics, edited by C. M. Surko and F. A. Gianturco,
Kluwer Academic Publishers, Dordrecht, pp. 437450 (2001).
Y. Kanai, K. Ando , T. Azuma, R. Hutton, K. Ishii, T.
Ikeda, Y. Iwai, K. Komaki, T. Kuroki, H. Masuda,
Y. Morishita, K. Nishio, H. Oyama, M. Sekiguchi,
and Y. Yamazaki: "Metastable states produced withbeam-capillary interaction", NucI. Instrum. Methods Phys. Res . B 182, 174- 179 (2001).
Y. Nakai, T. Kambara, A. Ito, H. Tsuchida, and Y.
Yamazaki: "Production of singly charged fullerenelike fragment ions a fast He 2+ -C 60 collision", Phys.
Rev. A 64 ,043205-1- 043205-6 (2001) .
R. Whitehead, J. l\1cCann, and 1. Shimamura: "Laserassisted formation of antihydrogen", Phys. Rev . A
64,023401-1- 023401-6 (2001).
N. Suzuki, Y. Nagai, Y. Itoh, A. Goto, Y. Yano, andT. Hyodo: "Vacancy formation energy for indium
determined by a positron annihilation technique",Phys. Rev. B 63 , 180101-1- 180101-3 (2001).
N. Kuroda, N. Ishikawa, Y. Chimi, A. Iwase, H. Ikeda,
R. Yoshizaki, and T. Kambara: "Effect of defectmorphology on the properties of the vortex system
in Bi2Sr2CaCu208+a irradiated with heavy ions",
Phys. Rev. B 63 , 224502-1- 224502-5 (2001).
M. Hori , J. Eades , R. S. Hayano, T. Ishikawa, J.
Sakaguchi, E. Widmann, H. A. Torii, B. Juhasz, D.
Hoevath, and T. Yamazaki: "Sub-ppm laser spectroscopy of antiprotonic helium and a CPT-violation
limit on the antiprotonic charge and mass", Phys.
Rev. Lett. 87, 093401-1- 093401-4 (2001).
T. Azuma, T. Ito, Y. Takabayashi, K. Komaki, Y.
Yamazaki, E. Takada, and K. Murakami: "Resonant
coherent excitation of hydrogen-like Ar ions to then = 3 states", Phys. Scr. T 92 , 61- 64 (2001).
A. Ito , T. Majima, H. Tsuchida, Y. Nakai, and T.
Kambara: "Charge-state dependence of C 60 - multifragmentation in collisions of 30 MeV Ne 2- 9 + ions",
Phys. Scr. T 92 ,176-178 (2001).
Y. Zou, R. Hutton, S. Huldt, K. Ando, and H. Oyama:"Effects of foil aging properties on the intensities
of atomic transition lines following ion-foil interaction", Phys. Scr. T 92 , 253- 255 (2001).
R. Hutton, Y. Zou , S. Huldt, K. Ando, and H. Oyama:"The spectroscopy of high spin states for highly
charged Mg-like ions" , Phys. Scr. T 92 , 325- 326(2001) .

328

M. Hoshino, M. Kitajima, Y. Kanai, Y. Nakai, H.
Tanaka, and Y. Yamazaki: "Angular resolved energy
gain spectroscopy to study double electron-capture
processes in very slow c4 + -He collisions" , Phys. Scr.
T 92 , 339- 340 (2001) .
Y. Kanai, D. Dumitriu, Y. Iwai, T. Kambara, T.
Kojima, A. Mouri, Y. Morishita, Y. Nakai, H.
Oyama, N. Ohshima, and Y. Yamazaki: "Slowhighly charged ion facility at RIKEN", Phys. Scr.
T 92 , 467- 470 (2001).
H. Ikeda, N. Ishikawa, A. Iwase, T. Kambara, K.
Yoshikawa, and R. Yoshizaki: "Flux pinning potential in Bi-2223 tapes irradiated by Xe ion", Physica
C 357/360 , 494- 496 (2001).
S. Okayasu, M. Sasase, N. Kuroda, A. Iwase, Y.
Kazumata, and T. Kambara: "Pinning propertiesof quenched and melt growth method-YBCO bulk
samples", Physica C 357/360, 501- 504 (2001).
T. Nakatsukasa and K. Yabana: "Real-space calculation of the continuum response: Photoabsorption inmolecules", Proc. 3rd Japan-Korea Joint Workshop
on 1st-Principles Electronic Structure Calculaions,(NRIM), Tsukuba, 2000- 10~1l , edited by T. Ohno ,NRIM, Tsukuba, pp. 112- 115 (2001) .
S. Kaneko, Y. Ono, N. Nishida, and T. Kambara:"Columnar defect-induced strain and superconductivity in Bi2Sr2CaCu20x observed by LT-STS/
STM", Surf. Sci. 493 , 692- 696 (2001).
4.

Radiochemistry, radiation chemistry, and radiation biology

S. Enomoto: "Development of the multitracer technique by using RIKEN Ring Cyclotron", Proc.
12th Symp. on Acccelerator Science and Technology,
Wako, 1999- 10, Wako, pp. 130- 131 (1999) .
R. Hirunuma and S. Enomoto: "Behavior of various
elements in selenium-deficient rats using the multitracer technique", Proc. 12th Symp. on Acccelerator Science and Technology, Wako, 1999- 10, Wako,
pp. 358- 360 (1999).
T. Yanagiya, N. Imura, S. Enomoto, and S. Himeno:"Screening for metals exhibiting altered accumulation in Cd-resistant metallothionein null cells using
a multitracer technique", Proc. 12th Symp. on Acccelerator Science and Technology, Wako, 1999- 10,
Wako, pp. 361- 363 (1999).
R. Hirunuma, S. Enomoto, F. Ambe, and H. Sakurai:"Behavior of various trace elements in Se-deficientrats", Proc. 16th Symp. on Trace Nutrients Research, Japan Trace Nutrients Research Society,No. 16, pp. 17- 24 (1999).
T. Ozaki, S. Enomoto, Y. Minai, S. Ambe, and Y.
Makide: "A survey of trace elements in pteridophytes", BioI. Trace Elem. Res. 74, 259- 273 (2000).
H. Sakurai, H. Yasui, T. Takino, A. Tamura, Y.
Kojima, K. Kawabe, S. Enomoto, and R. Hirunuma:

"Treatment of diabetes by vanadium", Biomed. Res.
Trace Elements II , 311-312 (2000).
K. Matsumoto, R. Hirunuma, S. Enomoto, and K .
Endo: "Contents and uptake rates of bio-traceelements in Se-deficient rat liver cell fractions" ,Biomed. Res. Trace Elements 11 , 403-404 (2000).
S. Enomoto , R. Hirunuma, and H. Tamano: "Transport and accumulation of trace elements in the pregnantrats - fetus", Biomed. Res. Trace Elements 11,439- 440 (2000).
F. Yatagai , S. Morimoto, A. Gordon, T. Nohmi , M.
Kusakabe, N. Fukunishi, T. Kurobe, T. Kato, T.
Mizuno, F. Hanaoka, and Y. Yano: "Biological effect of p53 after heavy-ion exposure" , Exploring Future Research Strategies in Space Radiation Sciences: Proc. 2nd Int. Space Workshop 2000 , (NIRS,
NASDA) , Chiba, 2000- 2, edited by H. J. Majima
and K. Fujitaka, Iryokagakusha, Chiba, pp. 92- 98(2000) .
T. Ozaki, S. Enomoto, Y. Minai , S. Ambe, F. Ambe,and Y. Makide: "Beneficial effect of rare earth elements on the growth of Dryopteris erythrosora", J.
Plant Physiol. 156, 330- 334 (2000).
Y. Furusawa, K. Fukutsu, M. Aoki , H. Itsukaichi, K.
Eguchi-Kasai, H. Ohara, F. Yatagai , T. Kanai, and
K. Ando: "Inactivation of aerobic and hipoxic cells
from three different cell lines by accelerated 3He- ,12C_ and 2oNe-ion beams", Radiat. Res. 154, 485496 (2000).
S. Enomoto: "Trace elements in man and animals",
SClaS 66 , 86- 90 (2000).
R. Hirunuma, S. Enomoto, S. Ambe, and F. Ambe:"Distribution of selenium, arsenic, iron, and scandium in selenium-deficient rats using the multitracer
technique", Trace Elements in Man and Animals 10,edited by A. M. Roussel, R. A. Anderson, and A. E.
Favier, Kluwer Academic/Plenum Publishers , New
York, pp. 1099- 1102 (2000).
S. Morimoto, A. Gordon, N. Fukunishi, and F.
Yatagai: "Cellular responses by exposure to heavyions", Adv. Space Res. 27, 401- 409 (2001) .
K. Matsumoto, T. Inagaki , R. Hirunuma, S. Enomoto,and K. Endo: "Contents and uptake rates of Mn, Fe,
Co , Zn, and Se in Se-deficient rat liver cell fractions" ,Anal. Sci. 17, 587- 591 (2001) .
C. Bae, T. Abe , T. Matsuyama, N. Fukunishi, N.
Nagata, T. Nakano , Y. Kaneko, K. Miyoshi, H.
Matsushima, and S. Yoshida: "Regulation of chloroplast gene expression is affected in ali, a novel
tobacco albino mutant ", Ann. Bot. 88, 545- 553(2001).
K. Ishioka, M. Hase, M. Kitajima, and K. Ushida:"Ultrafast carrier and phonon dynamics in ionirradiated graphite", Appl. Phys. Lett . 78, 39653967 (2001).
S. Enomoto: "The multitracer technique: Manufacturing and application on the bio-trace elemental

research", Biomed. Res. Trace Elements 12, 71- 84(2001) .
H. Tamano, B. Liu, S. Enomoto , and A. Takeda: "Tumor accumulation of radioact ive trace elements: A
multi tracer study", Biomed. Res. Trace Elements
12, 96- 101 (2001).
P. Mehnati, F. Yatagai, T. Tsuzuki , F. Hanaoka, and
H. Sasaki: "Judgement on "hit or non-hit" of CHO
cells exposed to accelerated heavy-ions (Fe- or Arions) using division delay and CR-39 plastics as anindicator", Fukuoka Acta Medica 92 , No.3 , pp. 4658 (2001).
Y. F. Yang, Y. Gono , S. Motomura, S. Enomoto, andY. Yano: "A compton camera for multitracer imaging", IEEE Trans. Nucl. Sci. 48 , 656- 661 (2001).
R. Amano and S. Enomoto: "Brain regional uptakeof radioactive Sc, Mn , Zn , Se, Rb and Zr tracers
into normal mice during aging" , J. Radioanal. N ucl.
Chern. 247, 507- 511 (2001).
T. Abe and S. Yoshida: "New method of plant mutagenesis using the RIKEN Ring Cyclotron", Radiat.
Chern. 71 , 28- 32 (2001).
S. Ambe, T. Ozaki, R. Weginwar, S. Enomoto, and F.
Ambe: "Simultaneous production of 28Mg and 47 Ca
by high-energy heavy-ion irradiation for applications
in biology", Radiochim. Acta 89 , 63- 66 (2001).
H. Wang, S. Ambe, N. Takematsu, and F. Ambe:"Multitracer studies on the effects of model acid rainon the adsorption of trace elements on soils", Radiochim. Acta 89, 101- 107 (2001).
K. Matsumoto , R. Hirunuma, S. Enomoto , and K.
Endo: "Evaluation of in vivo oxidative stress inliver of selenium-deficient rat", RIKEN Rev. No . 35,
pp. 14- 18 (2001 ).
S. Enomoto and R. Hirunuma: "Fetoplacental transport of various trace elements in pregnant rat using the multitracer technique", RIKEN Rev. No. 35 ,pp. 31- 34 (2001).
R. Hirunuma, K. Endo, S. Enomoto, and F. Ambe:"Study on the distribution of radioactive trace elements in vitamin D-overloaded and deficient rats using the multiracer technique", RIKEN Rev. No. 3Q ,pp. 35- 39 (2001).
R. Hirunuma, T. Ozaki, K. Endo, H. Yasui , H. Sakurai,
and S. Enomoto: "Uptake of various elements inselenium-deficient rats: Application of the multitracer technique", RIKEN Rev. No. 35, pp. 40-44(2001).
H. Yasui , T. Takino, J. Fugono, R. Hirunuma, S.
Enomoto , and H. Sakurai: "Effect of vanadium
treatment on tissue distribution of biotrace elements
in normal and streptozotocin-induced diabetic rats:
Simultaneous analysis of V and Zn using radioactive
multitracer", RIKEN Rev. No. 35, pp. 45- 47 (2001) .
A. Nakayama, H. Yasui , R. Hirunuma, S. Enomoto ,and H. Sakurai: "Distribution of biotrace elementsin partially hepatectomized rats" , RIKEN Rev.

329

No. 35, pp. 48- 49 (2001).
K. Igarashi, A. Sasaki, Y. Yoda, H. Inage, Y.
Nakakoshi, T. Yanagiya, R. Hirunuma, S. Enomoto,and S. Kimura: "Effect of sodium iron ethylenediaminetetraacetic acid on the absorption of various
trace elements in anemic rats" , RIKEN Rev. No. 35,
pp. 50- 54 (2001).
T. Ohyama, T. Yoshida, H. Maetsu, M. Noguchi, H.
Suganuma, R. Hirunuma, S. Enomoto, M. Yanaga,
and T. Omori: "Specific cobalt metabolism underZn-deficient condition", RIKEN Rev. No. 35, pp. 5556 (2001).
H. Tamano, S. Enomoto, R. Hirunuma, and A. Takeda:"Uptake of radioactive elements in rats brain tumor", RIKEN Rev. No. 35, pp. 57-58 (2001).
T. Tarohda, Y. Yabushita, Y. Kanayama, R. Amano,
and S. Enomoto: "Elemental concentrations andtracer uptake behavior of manganese, zinc, and selenium in brain of normal mice during development",
RIKEN Rev. No. 35, pp. 61- 63 (2001).
Y. Yabushita, Y. Kanayama, T. Tarohda, K.
Washiyama, R. Amano, and S. Enomoto: "Elementelement interrelationship in brain under deficientand excessive states of an essential trace element",
RIKEN Rev. No. 35, pp. 64- 66 (2001).
S. Yoshida, M. Masuda, M. Nakayama, M. Yamasaki,
H. Morikawa, R. Hirunuma, and S. Enomoto:"Study on the absorption site of divalent cations in
the intestinal loop, using the multitracer technique" ,RIKEN Rev. No. 35 , pp. 67- 68 (2001).
T. Nabekura, T. Minami, R. Hirunuma, S. Enomoto,and Y. Ito: "Uptake of trace elements in adult andsuckling rat lenses", RIKEN Rev. No. 35, pp. 69- 70(2001).
T. Yanagiya, N. Imura, S. Enomoto, Y. Kondo, and
S. Himeno: "Reduction of cadmium cytotoxicity by
manganese", RIKEN Rev. No. 35, pp. 71- 72 (2001) .
Y. Oura, S. Enomoto, and H. Nakahara: "Applicationof prompt gamma ray analysis to biological sampIes", RIKEN Rev. No. 35, pp. 73- 75 (2001).
J. Furukawa, R. Hirunuma, S. Enomoto , and T.
Nakanishi: "Measurement of binding affinity of various metal elements to plant apoplast protein in roottips", RIKEN Rev. No. 35, pp. 78- 79 (2001).
H. Suzuki, H. Kumagai, F. Mori, K. Sakamoto, K.
Inubushi , and S. Enomoto: "Influence of lanthanumon the uptake of various elements by marigold",
RIKEN Rev. No. 35, pp. 80- 81 (2001).
T. Ozaki and S. Enomoto: "Uptake of rare earth elements by Dryopteris erythrosora (autumn fern)",
RIKEN Rev. No. 35 pp. 84- 87 (2001).
R. Amano, T. Tsuji, K. Washiyama, S. Enomoto, K.
Tagami, and S. Uchida: "Isolation and purificationof 95mTc and 96Tc from Ag target irradiated withheavy ion beams", RIKEN Rev. No. 35, pp. 94- 95(2001) .
C. Egawa, Y. Takahashi, S. Enomoto, R. Hirunuma,

330

and H. Shimizu: "Multitracer study on the diffusion
behavior of various ions through the porewater of
granite", RIKEN Rev. No. 35, pp. 96- 97 (2001).
S. Shibata, S. Enomoto, and R. Hirunuma: "Preliminary study of amalgam extracting method for production of multitracer", RIKEN Rev. No. 35, p. 115(2001).
S. Motomura, Y. Yang, Y. Gono, S. Enomoto, Y. Yano,
and K. Asahi: "MT-GEI: A new detection system
for multirtracer" , RIKEN Rev. No. 35, pp. 116- 117(2001) .
H. Suzuki, H. Kumagai, K. Oohashi, K. Sakamoto, K.
Inubushi, and S. Enomoto: "Transport of trace elements through the hyphae of an arbuscular mycorrhizal fungus into marigold determined by the multitracer technique", Soil Sci. Plant Nutr. 47, 131- 137(2001) .
T. Nabekura, T. Minami, R. Hirunuma, S. Enomoto,R. Hori, and Y. Ito: "Comparative uptake behaviorof trace elements in adult and suckling rat lens",
Toxicology 163, 101- 105 (2001).
5.

Material analysis

M. Tanaka and K. Takahashi: "Determination of thechanges of the basic structures of silica species independence on the concentration of sodium chloride
by FAB-MS", Fresenius J. Anal. Chern. 368 , 786790 (2000).
K. Maeda, T. Hasegawa, H. Hamanaka, K. Hasegawa,and M. Maeda: "Direct speciation of sulfur inmarine sediment by high-resolution PIXE", Int. J.
PIXE 10, 47- 56 (2000).
T. Sugimura, J. Kawai, K. Maeda, A. Fukushima, S.
Shin, M. Motoyama, and T. Nakajima: "F K-edge
soft X-ray absorption spectroscopy", Adv. X-Ray
Chern. Anal. Jpn. 32 , 161- 172 (2001).
K. Maeda, K. Hasegawa, and H. Hamanaka: "Chemical specification by high-resolution PIXE" , Proc. 1st
Seminar on Application of Accelerator Radiation,(National Tsing Hua University), Hsinchu, Taiwan,
2000- 12, edited by T.-C. Chu, National Tsing Hua
University, Hsinchu, pp. 263- 273 (2001).
6.

RIKEN-BNL Collaboration on Spin Physics Program

R. Jaffe and N. Saito: "QCD selection rules in polarized hadron collisions'~, Phys. Lett. B 382 , 165- 172(1996).
N. Saito and PHENIX Collaboration: "Spin physics
with the PHENIX detector system", Nucl. Phys. A
638 , 575c- 578c (1998).
H. Hamagaki and N. Saito: "The PHENIX experiment and PHENIX-J activities", Nucl. Phys. News
8 , No.4, pp. 26- 30 (1998).
N. Saito: "High Energy Spin Physics and RIKEN BNL
Research Center", Parity 13, No. 12, pp. 108- 109

(1998).
N. Hayashi, Y. Goto, and N. Saito: "RHIC spin
physics", Proc. 6th Int. Workshop on Deep Inelastic Scattering and QCD: DIS98 , Brusseis, Belgium,
1998- 4, edited by G. H. Coremans and R. Roosen,
World Scientific, Singapore, pp. 675- 679 (1998).
G. Bunce, N. Saito, J. Soffer, and W . Vogelsang:"Prospects for spin physics at RHIC", Ann. Rev.
Nucl. Part. Sci. 50, 525- 575 (2000).
B. A. Berg, H. Markum, R. Pullirsch, and T. Wettig:"Spectrum of the U (1) staggered Dirac operator
in four dimensions", Phys. Rev. D 63 , 014504-1014504-4 (2000).
E. Laenen, G. Sterman, and W. Vogelsang: "Higherorder QCD corrections in prompt photon production", Phys. Rev. Lett. 84, 4296- 4299 (2000).
T. Tominaka, M. Okamura, and T. Katayama: "Analytical field calculation of helical coils", Nucl. Instrum. Methods Phys. Res. A 459, 398- 411 (2001).
N. Ishii: "Goldberger-Treiman relation and g7fNN fromthe three quark BS/Faddeev approach in the NJL
model", Nucl. Phys. A 689 , 793- 845 (2001).
A. Ali Khan, S. Aoki , Y. Aoki, R. Burkhalter, S. Ejiri ,M. Fukugita, S. Hashimoto, N. Ishizuka, Y. Iwasaki,
T. Izubuchi, K. Kanaya, T. Kaneko , Y. Kuramashi,
T. Manke, K. Nagai, J. Naoki, M. Okawa, H. P.
Shanahan, Y. Taniguchi, A. Ukawa, and T . Yoshie:"Calculation of K ---7 7r matrix elements in quencheddomain-wall QCD", Nucl. Phys. B (Proc. Suppl.)
94,283-286 (2001).
A. Ali Khan, S. Aoki , Y . Aoki, R. Burkhalter, S. Ejiri,
M. Fukugita, S. Hashimoto, N. Ishizuka, Y. Iwasaki,
T. Izubuchi, K. Kanaya, T. Kaneko, Y. Kuramashi ,K. Nagai , J. Naoki, M. o kawa , H. P. Shanahan,
Y. Taniguchi, A. Ukawa, and T . Yoshie: "Kaon Bparameter from quenched domain-wall QCD", Nucl.
Phys. B (Proc. Suppl.) 94, 287- 290 (2001).
A. Ali Khan , S. Aoki, Y. Aoki, R. Burkhalter, S. Ejiri,
M. Fukugita, S. Hashimoto, N. Ishizuka, Y. Iwasaki,
T. Izubuchi, K. Kanaya, T. Kaneko, Y. Kuramashi,
T. Manke, K. I. Nagai, J. Naoki , M. o kawa , H. P.
Shanahan, Y. Taniguchi, A. Ukawa, and T . Yoshie:"Eigenvalues of the hermitian Wilson-Dirac operator
and chiral properties of the domain-wall fermion",
Nucl. Phys. B (Proc. Suppl.) 94, 725- 728 (2001).
R. Baier, A. Mueller, D. Schiff, and D. Son: "Bottomup thermalization in heavy ion collisions", Phys.
Lett. B 502 , 51- 58 (2001).
K. Kurita and E-802 Collaboration: "Systematics of
midrapidity transverse energy distributions in limited apertures from p+Be to Au+Au collisions at
relativistic energies", Phys. Rev. C 63, 064602-1064602-25 (2001).
M. Glueck, E. Reya, M. Stratmann, and W. Vogelsang:"Models for the polarized parton distributions of
the nucleon", Phys. Rev. D 63 , 094005-1- 094005-12(2001) .

M. Wingate and S. Ohta: "Deconfinement transitionand string tensions in SU(4) Yang-Mills theory",
Phys. Rev. D 63, 094502-1- 094502-9 (2001).
A. Ali Khan, S. Aoki, Y. Aoki, R. Burkhalter, S.
Ejiri, M. Fukugita, S. Hashimoto, N. Ishizuka, Y.
Iwasaki , T. Izubuchi, K. Kanaya, T. Kaneko, Y.
Kuramashi , T. Manke, I. K. Nagai, J. Naoaki, M.
o kawa , P. H. Shanahan, Y. Taniguchi, A. Ukawa,and T. Yoshie: "Chiral properties of domain-wallquarks in quenched QCD" , Phys. Rev. D 63 , 1145041- 114504-19 (2001).
M. Stratmann and W. Vogelsang: "Towards a global
analysis of polarized parton distributions", Phys.
Rev. D 64, 114007-1- 114007-10 (2001).
A. Ali Khan, S. Aoki, Y. Aoki, R. Burkhalter, S.
Ejiri, M. Fukugita, S. Hashimoto, N. Ishizuka, Y.
Iwasaki , T. Izubuchi, K. Kanaya, T. Kaneko , Y.
Kuramashi, T. Manke, K. Nagai, J. Naoki, M.
Okawa, H. P. Shanahan, Y. Taniguchi, A. Ukawa,and T. Yoshie: "Kaon B parameter from quencheddomain-wall QCD", Phys. Rev. D 64, 114506-1114506-21 (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, F. 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
charged particle multiplicity in Au-Au collisions at
JS N N = 130 GeV", Phys. Rev. Lett. 86, 3500- 3505
(2001).
D. Son, M. Stephanov, and A. Zhitnisky: "Domain
wall of high density QCD", Phys. Rev. Lett. 86,
3955- 3958 (2001).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En'yo,
Y. Goto, P. M. Gross, N. Hayashi, T. Ichihara, K.
Imai , M. Ishihara, K. Kurita, Y. Mao, J . Murata, N.
Saito, F . Sakuma, H. Sato, T. Shibata, A. Taketani,
J. Tohjo, H. Torii, Y. Watanabe, S. Yokkaichi, and
PHENIX Collaboration: "Mesurement of the midrapidity transverse energy distribution from JS N N =130 Gev Au + Au collisions at RHIC", Phys. Rev.
Lett. 87, 05230-1- 05230-6 (2001).
V. W. Hughes, M. G. Perdekamp, D. Kawall , W. Liu,
K. Jungmann, and G. zuPutlitz: "Test of CPT and
Lorentz invariance from muonium spectroscopy",
Phys. Rev. Lett. 87, 11804-1- 11804-4 (2001).
M. Gockeler , P. E. L. Rakow, A. Schafer, W. Soldner,and T. Wettig: "Calorons and localization of quark
eigenvectors in lattice QCD" , Phys. Rev. Lett. 87,
042001-1- 042001-4 (2001).
D. Rischke, D. Son, and M. Stephanov: "Asyptonic deconfinement in high-density QCD" , Phys. Rev. Lett.
87, 062001-1- 062001-4 (2001).
A. Kusenko and P. J. Steinhardt: "Q-ball candidates
for self-interacting dark matter", Phys. Rev. Lett.

331

87, 141301-1- 141301-4 (2001).
N. Ishii, H. Suganuma, and H. Matsufuru: "Glueball properties in anisotropic SU(3) lattice QCD
with an improved action", Proc. of the Workshop on Lepton Scattering, Hadrons and QCD,(The Special Research Center for the Subatomic
Structure of Matter, National Institute for Theoretical Physics) , Adelaide , Australia, 2001- 3 ~ 4,edited by W. Melnitchouk, A. W. Schreiber, A. W.
Thomas , and P. C. Tandy, World Scientific, Singapore, pp. 252- 259 (2001).
K. Itakura and S. Maedan: "Light-front realization ofchiral symmetry breaking", Prog. Theor. Phys. 105,
537- 571 (2001).
M. Gockeler, H. Hehl, P. E. L. Rakow, A. Schafer, and

332

T. Wettig: "Spectrum of the SU(3) Dirac operator
on the lattice: Transition from random matrix theory to chiral perturbation theory", Phys. Rev. D 65 ,
034503-1- 034503-10 (2002).
A. Bazilevsky, G. M. Bunce, A. Deshpande, H. En 'yo,
M. G. Perdekamp, N. Hayashi , T. Ichihara, K. Imai ,M. Ishihara, B. V. Jacak, K. Kurita, Z. Li , Y. Mao,
J. Murata, N. Saito, F. Sakuma, H. Sato, T. Shibata,
M. Sugioka, A. Taketani, E. Taniguchi, J. Tojo ,H. Torii , Y. Watanabe, S. Yokkaichi, and PHENIX
Collaboration: "Suppression of Hadrons with large
trasverse momentum in central Au + Au collisions
at JS N N = 130 GeV", Phys. Rev. Lett. 88 , 0223011- 022301-6 (2002).

VIII. LIST OF PREPRINTS
2001
RIKEN-AF-NP
381 N. Dinh. Dang, V. K. Au, T . Suzuki, and A. Arima: "E1 resonances in neutron-rich nuclei within phonon
darn ping model"
382 Y. Mochizuki:
INTEGRAL",,44Ti: Its initial abundance in Cas A and its detection possibility in SN 1987A with

383 T. Kato, T. Doke, J. Kikuchi, F. Nishikido, H. Okada, K. Morimoto, and 1. Tanihata: "Time and energy
resonanses of liquid-xenon scintillation chamber for 20Ne ion beam at 135A MeV"
384 A. Ozawa, T. Suzuki, and 1. Tanihata: "Nuclear size and related topics"
385 Y. X. Watanabe, A. Yoshida, T. Fukuda, T. Sekine, Y. Watanabe, H. Ikezoe, Y. Nagame , T. Ikuta, 1.
Nishinaka, Y. Mizoi, J. Nakano, M. Hirai, H. Sakurai, H . Kobinata, Y. Pu , K. Kimura, and M. Ishihara:"Measurement of fusion excitation functions of 27,29,31 AI+197 Au"
386 N. Itagaki, S. Okabe, K. Ikeda, and 1. Tanihata: "Molecular-orbital structure in neutron-rich C isotopes"
387 H. Sagawa and K. Asahi: "N/ Z dependence of core polarization charges and quadrupole moments of Bisotopes"
388 P. Kienle and T. Yamazaki: "Empirical deduction of a medium-modified quark condensate from 1 s 7[states in heavy nuclei"
389 H. Geissel, H. Gilg, A. Gillitzer , R. S. Hayano, S. Hirenzaki, K. Itahashi, M. Iwasaki , P. Kienle , M. Munch,
G. Munzenberg, W. Schott, K. Suzuki, D. Tomono, H. Weick, T. Yamazaki, and T. Yoneyama: "Deeply
bound Is and 2p pionic states in 205Pb and determination of the s-wave part of the pion-nucleus interaction"
390 M. Hori , J. Eades , R. S. Hauyano, T. Ishikawa, J. Sakaguchi, E. Widmann, H. Yamaguchi, H. A. Torii, B.
Juhasz , D. Horvath, and T. Yamazaki: "Sub-ppm laser spectroscopy of antiprotonic helium and a CPTviolation limit on the antiprotonic charge and mass"
391 T. Yamazaki: "Antiprotonic helium - An exotic hydrogenic atom"
392 Y. Akaishi and T. Yamazaki: "Deeply-bound kaonic nuclear states"
393 T . Yamazaki: "Strangeness nuclear physics toward the new millenium - A personal summary of HYP2000"
394 H. Koura, M. Uno, T . Tachibana, and M. Yamada: "Table of atomic masses and related quantities calculatedby the mass formula of Koura, Uno, Tachibana, and Yamada"
395 M. Petrascu, 1. Tanihata, K. Kobayashi, M. Giurgiu, K. Morimoto, K. Katori, 1. Cruceru, A. Isbasescu , H.
Petrascu, R. Ruscu, M. Chiba, Y. Nishi, S. Nishimura, A. Ozawa, T. Suda, K. Yoshida, A. Constantinescu,
C. Bordeanu, and A. Tudorica: "Neutron pair pre-emission in the fusion of 11 Li halo nuclei with Si targets"
396 M. Terasawa, K. Sumiyoshi, T. Kajino, G. J. Mathews, and 1. Tanihata: "New nuclear reaction flow duringr-process nucleosynthesis in supernovae: Critical role of light neutron-rich nuclei"
397 S. Takeuchi, S. Shimoura, T. Motobayashi, H. Akiyoshi , Y. Ando, N. Aoi, Zs. 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: "Isobaric analog of 14Be"

333

398 T. Motobayashi: "Indirect measurements of the solar-neutrino production reaction 7Be(p,1) BB"
399 H. Kurasawa and T. Suzuki: "Electron scattering in relativistic nuclear models"

400 R. Kanungo, 1. Tanihata, and A. Ozawa: "Possibility of enlarged core structure of N =15 neutron-richnuclei"401 R. Kanungo, 1. Tanihata, and A. Ozawa: "Observation of new neutron and proton magic numbers"
402 M. Hirai, S. Kumano, and M. Miyama: "Parton distribution functions in nuclei"
403 K. Sugawara-Tanabe, S. Yamaji , and A. Arima: "Pseudospin symmetry and spin symmetry in the relativistic
mean-field with deformed potential"
404 T. Motobayashi: "Spectroscopy of nuclei around N = 20 with direct reactions"
405 Y. Akaishi and T. Yamazaki: "Nuclear K bound states in light nuclei"
406 T. Yamazaki , N. Morita, R. S. Hayano, E. Widmann, and J. Eades: "Antiprotonic helium"
407 N. Dinh. Dang and V. Zelevinsky: "Improved treatment of ground-state correlations: Modified random
phase approximation"
408 N. Itagaki, S. Hirose, T. Otsuka, and K. Ikeda: "Triaxial deformation in lOBe"
409 H. Iwasaki, T. Motobayashi, H. Sakurai, K. Yoneda, T. Gomi, N. Aoi, N. Fukuda, ZS. Fulop , U. Futakami,
Z. Gacsi, Y. Higurashi, N. Imai , N. Iwasa, T. Kubo, M. Kunibu, M. Kurokawa, Z. Liu, T. Minemura, A.
Saito, M. Serata, S. Shimoura, S. Takeuchi, Y. X. Watanabe, K. Yamada, Y. Yanagisawa, and M. Ishihara:"Large collectivity of 34Mg"
410 Y. Satou, S. Ishida, H. Sakai, H. Okamura, H. Otsu , N. Sakamoto, T. Uesaka, T. Wakasa, T. Ohnishi,
K. Sekiguchi, K. Yako , T. Ichihara, T. Niizeki, K. S. Itoh, and N. Nishimori: "Measurement of single anddouble spin-flip probabilities in inelastic deuteron scattering on l2C at 270 MeV"
411 N. Dinh. Dang: "Strength of the double-phonon state within an exactly solvable model"

412 T. Yamazaki: "Quasi-stable exotic atoms/nuclei as resonances states"
413 A. Kohama, R. Seki, A. Arima, and S. Yamaji: "Determination of matter surface distribution of unstable
nuclei"

RIKEN-AF-AC
26 A. Bolshakov, P. Zenkevich, and T. Katayama: "Code for calculation of dynamical aperture with accountof the space charge effect and its application to ACR storage Ring"
27 V. Alexandrov , N. Kazarinov, V. Mironov. V. Shevtsov, G. Shirkov, Y. Yano, and T. Nakagawa: "Optimization of ion beam line from ECRIS to RFQ at RIKEN"
28 G. Shirkov: "Different modes of laser ion loading into ECR ion source"
29 M. Takanaka: "Characteristics of electron-cooled bunched beams predicted by a simulation"
30 C. C. Yun: "The simulation of emittance growth by Ray-tracing method"334

31 A. Skrinsky, I. Meshkov, V. Alexandrov, V. Shevtsov, and G. Shirfkov: "Selected reports of the ISTCRIKEN Japan workshop on Russia/CIS accelerator technologies"
32 N. Nagaoka: "Evoluation of some properties of the electron ring for MUSES"

335

IX. PAPERS PRESENTED AT MEETINGS
1.

Accelerator
physics

development

andaccelerator

T. Tominaka, M. Okamura, and T. Katayama: "Rotation angle of a helical dipole", 1999 Particle Accelerator Conf. (PAC '99), (Brookhaven National Laboratory), New York , USA, Mar.- Apr. (1999).
A. Goto: "RIKEN RI Beam Factory", Seminar on
Accelerator Technology and Its Applications, Yogyakarta, Indonesia, Sept. (2000).
Y. Yano, T. Katayama, A. Goto, and M. Kase:"RIKEN RI Beam Factory Project", 16th Int. Conf.
on Application of Accelerators in Research and Industry, Denton, USA, Nov. (2000).
T. Mitsumoto, A. Goto, M. Kase , J. Ohnishi, O.
Kamigaito, N. Sakamoto, K. Ikegami , H. Okuno ,Y. Miyazawa, Y . Yano, T . Hiasa, and Y . Kumata:"Construction of the RIKEN IRC" , 16th Int. Conf.
on Cyclotrons and Their Applicat ions, East Lansing,USA, May (2001).
A. Goto, H. Okuno , J. Ohnishi, N. Fukunishi, T.
Mitsumoto, S. Fujishima, T. Tominaka, K. Ikegami,
Y. Miyazawa, and Y. Yano: "Progress on the sector
magnets for the RIKEN SRG', 16th Int. Conf. on
Cyclotrons and Their Applications, East Lansing,USA, May (2001).
S. Vorojtsov , A. Vorozhtsov, A. Goto, T. Mitsumoto,
N. Fukunishi, and Y. Yano: "Space charge effects in
RIKEN Cyclotrons", 16th Int. Conf. on Cyclotrons
and Their Applications , East Lansing, US A, May(2001).
J . Ohnishi, T. Mitsumoto, A. Goto , and Y. Yano:"Magnetic field measurement of RIKEN IRC sector
magnets", 16th Int. Conf. on Cyclotrons and Their
Applications , East Lansing , USA, May (2001).
T. Tanabe, M. Nishiura, 1. Watanabe, T. Katayama,
E. Syresin, and 1. Meshikov: "MUSES-ACR electron coolers" , Workshop on Beam Cooling and Related Topics 2001, (Forschungszentrum Julich) , Bad
Honnef, Germany, May (2001) .
M. Kidera, T . Nakagawa, S. Enomoto, K. Takahashi,
H. Baba, R. Hirunuma, T . Ohyama, K. Igarashi,
M. Fujimaki, E. Ikezawa, O. Kamigaito, M. Kase,
A. Goto , and Y. Yano: "Development of new analytical system using the electron cyclotron resonance ion source and heavy ion linear accelerator" , Int. Congr. on Analytical Sciences 2001 (ICAS
2001 ), (The Japan Society for Analytical Chemistry), Tokyo, Aug. (2001) .
O. Kamigaito , M. Kase, E. Ikezawa, M. Fujimaki, S.
Kohara, N. Fukunishi, N. Sakamoto, M. Hemmi , Y.
Miyazawa, Y. Chiba, T. Chiba, A. Goto, and Y.
Yano: "Upgrade of RIKEN heavy-ion linac for nuclear physics experiments", 26th Linear Accelerator
Meet. in Japan, (KEK) , Tsukuba, Aug . (2001).

336

M. Kidera, T. Nakagawa, Y. Higurashi , M. Kase, andY. Yano: "Effect of plasma chamber surface for production of highly charged ions from ECRIS", 9th Int.
Conf. on Ion Sources, (Lawrence Berkeley National
Laboratory), Oakland , USA, Sept. (2001).
Y. Higurashi, T. Nakagawa, M. Kidera, T. Aihara,
M. Kase , and Y. Yano: "Effect of plasma electrode position on the beam intensity of heavy ionsfrom RIKEN 18 GHz ECRIS" , 9th Int. Conf. on Ion
Sources, (Lawrence Berkeley National Laboratory),
Oakland, USA, Sept. (2001).
T. Nakagawa, M. Kidera, T . Kurita, Y. Higurashi, T .
Kageyama, M. Kase, and Y. Yano: "Intense beam
production from RIKEN 18 GHz ECRIS and liquid
He free SC-ECRIS", 9th Int. Conf. on Ion Sources,(Lawrence Berkeley National Laboratory), Oakland,
USA, Sept. (2001).
Y. Yano: "Progress report on RI Beam Factory Projectat RIKEN (Invited)", 2nd Asian Particle Accelerator Conf. (APAC '01) , (Institute of High Energy
Physics of the Chinese Academy of Sciences), Beijing, China, Sept. (2001).
M. Takanaka:"Characteristics of electron-cooled
bunched beams predicted by a simulation", 13th
Symp. on Accelerator Science and Technology,(RCNP and ISIR, Osaka University), Suita, Oct.
(2001) .
M. Nishiura, T. Tanabe, T. Katayama, 1. Watanabe,
and E . Syresin: "Development of MUSES electron
cooler at RIKEN", 13th Symp . on Accelerator Science and Technology, (RCNP and ISIR, Osaka University), Suita, Oct. (2001) .
O. Kamigaito , N. Sakamoto, M. Kase , E . Ikezawa, S.
Kohara, Y. Miyazawa: T. Chiba, M. Hemmi , Y.
Chiba, A. Goto, and Y. Yano: "Rf cavities of the
RIKEN charge-state multiplier", 13th Symp . on Accelerator Science and Technology, (RCNP and ISIR,
Osaka University), Suita, Oct. (200 1).
T. Masuoka, M. Takano, and T. Katayama: "Preliminary design of MUSES control system based on RTCORBA and java", 8th Int. Conf. on Accelerator
and Large Experimental Physics Control Systems(ICALEPCS 2001) , (SLAC) , San Jose , USA, Nov.
(2001).
2.

Nuclear physics and nuclear instrumentation

H. Ogawa, K. Sakai, T. Suzuki, M. Nagakura, H.
Miyoshi, K. Asahi , K. Yogo, A. Goto, T . Suga, T .
Honda, A. Yoshimi, H. Ueno, N. Imai, Y. Watanabe,
K. Yoneda, N. Fukuda, N. Aoi, Y. Kobayashi, W.
Schmidt-Ott, G. Neyens, S. Teughels, A. Yoshida, T.
Kubo, and M.d Ishihara: "Electric quadrupole moment of 17B and magnetic moment of 15 C measured
with polarized radioac tive beams", Int. RIKEN

Symp. on Shell Model 2000, Wako, Mar. (2000).
K. Asahi, K. Sakai, H. Ogawa, H. Miyoshi, K. Yogo, A.
Goto, T. Suga, H. Ueno, Y. Kobayashi , A. Yoshida,
T. Kubo, Y. Watanabe, N. Imai, K. Yoneda, N.
Fukuda, N. Aoi , M. Ishihara, W. Schmidt-Ott, G.
Neyens, and S. Teughels: "Electromagnetic moments of neutron-rich nuclei measured with polarized radioactive ion beams", Int. RIKEN Symp. on
Shell Model 2000, Wako, Mar. (2000).
K. Asahi: "Nuclear spin maser, and an attempt at
new masing scheme", Int. Symp. on Strong Correlations in Many-body Systems, (University of Tokyo) ,Nikko, June (2000).
J. Kim, F. Saito, N. Suzuki, L. Wei, T. Kurihara,
Y. Nagashima, M. Okamura, Y. Itoh, A. Goto,
T. Hyodo, and F. Saito: "A design of spin rotator for polarized slow positron beam at RIKEN" ,12th Int. Conf. on Positron Annihilation (ICPA-12) ,Munchen, Germany, Aug. (2000).
H. Ogawa, K. Asahi , H. Ueno, T. Suzuki, M.
Nagakura, A. Goto, T. Suga, K. Yo go , H. Miyoshi,
T. Honda, K. Sakai, A. Yoshimi, Y. Watanabe,
N. Imai , K . Yoneda, N. Aoi, N. Fukuda, Y.
Kobayashi, A. Yoshida, T. Kubo , W. Schmidt-Ott,
G. Neyens, and S. Teughels: "Electromagnetic moment of neutron-rich nuclei", CNSjRIKEN Symp.
on Physics of RI-Beam at Low Energy, Wako, Aug.
(2000).
K. Asahi: "RIKEN radioactive beam facility and polarized radioactive beams", Int. School of Nuclear
Physics , 22nd Course Radioactive Beams for Nuclear and Astro Physics, (Deutsche Forschungsgemeinschaft), Erice, Italy, Sept. (2000).
K. Morimoto, K. Morita, 1. Tanihata, N. Iwasa, R.
Kanungo, T. Kato, K. Katori, H. Kudo, T. Suda,
1. Sugai, S. Takeuchi, F. Tokanai , K . Uchiyama, Y.
Wakasaya, T. Yamaguchi, A. Yeremin, A. Yoneda,
and A. Yoshida: "Search for a Z = 118 superheavy nucleus in the reaction of Kr with Pb target at RIKEN" , Tours Symp. on Nuclear Physics IV(TOURS 2000), Tours, France, Sept. (2000).
H. Ogawa, K. Sakai, H. Ueno, M. Nagakura, K. Asahi,
H. Miyoshi, T. Suzuki, K. Yo go , A. Goto, T. Suga,
T. Honda, N. Imai, Y. Watanabe, K. Yoneda, A.
Yoshimi, N. Fukuda, N. Aoi, Y. Kobayashi, W.
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", 14th Int. Spin Physics Symp.
(SPIN 2000), (RCNP and ISIR, Osaka University) ,Suita, Oct. (2000).
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. Schmidt-Ott, G. Neyens, S. Teughels,
A. Yoshida, T. Kubo, and M. Ishihara: "Nuclear
moment studies with polarized radioactive nuclear

beams", 14th Int. Spin Physics Symp. (SPIN 2000),(RCNP and ISIR, Osaka University), Suita, Oct.
(2000).
H. Ueno, H. Miyatake, Y . Yamamoto, M. Sasaki,
N. Aoi , Y. Mizoi, T. Shimoda, A. Ozawa, K.
Yoneda, H. Izumi, H. Ogawa, M. Notani, K. Asahi,
S. Tanimoto, E. Ideguchi , T . Kubo, T. Kishida,
S. Mitsuoka, T. Shirakura, N. Takahashi, and M.
Ishihara: "Beta-delayed neutron spectroscopy using a spin-polarized 17B beam", Int. Symp. on Perspectives in Physics with Radioactive Isotope Beams
2000 (RIBOO), (RIKEN and Center for Nuclear
Study, University of Tokyo), Hayama, Nov. (2000).
S. Takeuchi , S. Shimoura, T. Motobayashi, H.
Akiyoshi, Y. Ando, N. Aoi, Z. FUlop, T. Gomi ,Y. Higurashi, M. Hirai, N. Iwasa, H. Iwasaki, Y.
Iwata, H. Kobayashi, M. Kurokawa, T. Minemura,S. Ozawa, H. Sakurai, M. Serata, T. Teranishi, K .
Yamada, Y. Yanagisawa, L. Zhong, and M. Ishihara:"Isobaric analog state of 14Be", Int. Symp. on Perspectives in Physics with Radioactive Isotope Beams
2000 (RIBOO) , (RIKEN and Center for Nuclear
Study, University of Tokyo), Hayama, Nov. (2000).
K. Yoneda, H. Sakurai, T. Gomi, T. Motobayashi,
N. Aoi, N. Fukuda, U. Futakami, Z. Gacsi, Y.
Higurashi, N. Imai, N. Iwasa, H. Iwasaki, T . Kubo,
M. Kunibu, M. Kurokawa, Z. Liu, T. Minemura,
A. Saito, M. Serata, S. Shimoura, S. Takeuchi, Y.
Watanabe, K. Yamada, Y . Yanagisawa, K. Yogo,
A. Yoshida, and M. Ishihara: "Very large deformation of the neutron-rich isotope 34Mg from in-beamgamma-ray spectroscopy with RI beam fragmentation", Int. Symp. on Perspectives in Physics with
Radioactive Isotope Beams 2000 (RIBOO), (RIKEN
and Center for Nuclear Study, University of Tokyo),
Hayama, Nov. (2000).
H. Ogawa, K. Asahi , K. Sakai, H. Ueno, T. Suzuki,
H. Miyoshi, M. Nagakura, K. Yogo, A. Goto, T.
Suga, T. Honda, N. Imai, Y. Watanabe, K. Yoneda,
N. Fukuda, A. Yoshimi, N. Aoi, Y . Kobayashi, W.
Schmidt-Ott, G. Neyens, S. Teughels, A. Yoshida, T .
Kubo, and M. Ishihara: "Quenching of neutron E2
effective charge in neutron-rich nuclei", Int. Symp.
on Perspectives in Physics with Radioactive Isotope
Beams 2000 (RIBOO), (RIKEN and Center for Nuclear Study, University of Tokyo), Hayama, Nov.
(2000).
H. Miyoshi, K. Asahi , H. Ogawa, H. Ueno, D. Kameda,
K . Yoneda, T. Suga, A. Goto, A. Yoshimi, H.
Watanabe, W. Sato, and T. Shinozuka: "Development of low energy polarized radioactive isotope beams" , Shingata Saikurotoron Kyoudou Riyou
Purojekuto Kentoukai, (Tohoku University) , Sendai,
Nov. (2000).
K . Yoneda, H. Sakurai, T. Gomi, T. Motobayashi,
N. Aoi, N. Fukuda, U. Futakami, Z. Gacsi, Y.
Higurashi, N. Imai, N. Iwasa, H. Iwasaki , T. Kubo,

337

M. Kunibu, M. Kurokawa, Z. Liu, T. Minemura,
A. Saito, M. Serata, S. Shimoura, S. Takeuchi, Y.
Watanabe, K. Yamada, Y. Yanagisawa, K. Yo go ,A. Yoshida, and M. Ishihara: "In-beam gammaray spectroscopy with RI projectile fragmentation" ,Workshop on Direct Reactions with Radioactive
Isotope Beams, (Rikkyo University), Tokyo , Nov.
(2000).
S. Takeuchi, S. Shimoura, T. Motobayashi, H.
Akiyoshi, Y. Ando, N. Aoi, Z. Ftilop, T. Gomi,
Y. Higurashi, M. Hirai, N. Iwasa, H. Iwasaki, Y.
Iwata, H. Kobayashi, M. Kurokawa, T. Minemura,S. Ozawa, H. Sakurai, M. Serata, T. Teranishi, K.
Yamada, Y. Yanagisawa, L. Zhong, and M. Ishihara:"Isobaric analog state of 14Be", Workshop on Direct
Reactions with Radioactive Isotope Beams, (Rikkyo
University), Tokyo, Nov. (2000).
T. Nakatsukasa: "Theoretical introduction to nuclear
collective motion", 11th RIKEN Winter School on
In-beam Gamma-ray Spectroscopy with RI Beams,
Tsunan-cho, Jan. (2001).
T. Nakatsukasa: "Linear response in the continuum
spectral region", Mean-field Approaches to Structure of Unstable Nuclei, Wako, Jan. (2001).
K. Ishida: "Simulation of pion and muon production
at a carbon target with 3 GeV proton beam", Muon
Science 2001 Symp. for KEK-JEARI Joint Project,(KEK, JEARI) , Tsukuba, Jan. (2001).
Y. Mochizuki: "Magic numbers related to the r-process
nucleosynthesis and RI-Beam Factory Project",Workshop on the Origin of the Elements and the
Evolution of the Universe, (Sophia University),
Tokyo, Jan. (2001).
S. Fujii: "Shell-model calculations for ~7 0 using microscopic AN and EN effective interactions", Int. Symp.
on Hadrons and Nuclei, (Yonsei University), Seoul,
Korea, Feb. (2001).
A. Ozawa: "Measurements of total reaction cross sections", Int. Workshop Reaction Mechanisms with
Exotic Nuclei, (ECT*), Trento, Italy, Feb. (2001).
T. Nakatsukasa and K. Yabana: "3D real space calculations of the continuum response", RIKEN Symp.
on Physics at Drip Lines, Wako, Feb. (2001).
K. Asahi, H. Ogawa, H. Ueno, H. Miyoshi, D. Kameda,
Y. Kobayashi, A. Yoshimi, K. Yo go , A. Goto,
T. Suga, K. Sakai, N. Imai, Y. Watanabe, K.
Yoneda, N. Fukuda, N. Aoi, A. Yoshida, T. Kubo,
M. Ishihara, W . Schmidt-Ott, G . Neyens, and S.
Teughels: "Quadrupole moments and magnetic moments in exotic nuclei", RIKEN Symp. on Physics
at Drip Lines, Wako, Feb. (2001).
T. N akatsukasa: "Local harmonic approaches to nuclear collective dynamics", Workshop on Nuclear
Structure of Unstable Nuclei, (Kyoto University),
Kyoto, Feb. (2001).
D. Kameda, K. Asahi, H . Ogawa, H. Ueno, H. Miyoshi,
K. Yoneda, H. Watanabe, N. Imai, T. Suga, K.

338

Oono, W . Sato, A. Yoshimi, K. Yogo, K. Sakai, Y.
Kobayashi, A. Yoshida, T. Kubo, and M. Ishihara:"Development of an adiabatic field rotation method
for the polarization measurement of a fragmentbeam", 56th Ann. Meet. of Physical Soc. of Japan,
Hachioji, Mar. (2001).
K. Ishida, K. Nagamine, T. Matsuzaki, S. Nakamura,N. Kawamura, Y. Matsuda, S. Sakamoto, M.
Tanase, M. Kato, H. Sugai, K. Kudoh, N. Takeda,
and G. Eaton: "Muon catalyzed fusion experimentin D-T system at RIKEN-RAL Muon Facility: Nonequilibrium effect", 56th Ann. Meet. of Physical Soc.
of Japan , Hachioji, Mar. (2001).
A. Kohama, S. Yamaji , R. Seki, and A. Arima: "Systematic error in analysis of one-body density distributions with a Gaussian-basis expansion", 56th
Ann. Meet. of Physical Soc. of Japan, Hachioji, Mar.
(2001).
Y. Mochizuki: "Video presentation "The quest for theorigin of the elements" and beyond (invited)", 56th
Ann. Meet. of Physical Soc. of Japan, Hachioji, Mar.
(2001).
T. Matsuzaki, K. Nagamine, K. Ishida, N. Kawamura,
Y. Matsuda, S. Nakamura, M. Tanase, M. Kato, H.
Sugai, K. Kudoh, N. Takeda, and G. Eaton: "t-tmuon catalyzed fusion experiment at RIKEN-RAL
Muon Facility: Fusion neutron energy distribution",
56th Ann. Meet. of Physical Soc. of Japan, Hachioji,Mar. (2001).
Y. Mochizuki: "Returded beta-deccay of 44Ti in supernova remnants and its importance", ISAS HighEnergy Astrophysics Branch Seminar, (The Institute of Space and Astronautical Science), Sagamihara, Apr. (2001) .
M. Kato, H. Sugai, M. Tanase, T. Matsuzaki, K.
Ishida, and K. Nagamine: "Development of compact
tritium gas recycling system", Int. RIKEN Conf. on
Muon Catalyzed Fusion and Related Exotic Atoms(/-lCF01), Shimoda, Apr. (2001) .
K. Ishida, K. Nagamine, T. Matsuzaki, N. Kawamura,
S. Nakamura, Y. Matsuda, M. Kato, H. Sugai, M.
Tanase, K. Kudo, N. Takeda, and G. H. Eaton:"Measurement of fusion protons and X-rays in muon
catalyzed d-t fusion at RIKEN-RAL", Int. RIKEN
Conf. on Muon Catalyzed Fusion and Related Exotic
Atoms (/-lCFOl), Shimoda, Apr. (2001).
T. Matsuzaki, K. Nagamine, K. Ishida, N. Kawamura,
S. Nakamura, Y. Matsuda, M. Kato, H. Sugai, M.
Tanase, K . Kudoh , N. Takeda, and G. Eaton: "Recent results on muon catalyzed t-t fusion at RIKENRAL", Int. RIKEN Conf. on Muon Catalyzed Fusion
and Related Exotic Atoms (/-lCF01) , Shimoda, Apr.
(2001) .
T. Nakatsukasa and K . Yabana: "Resonance and continuum states in weakly bound systems", 7th Int.
Spring Seminar on Nuclear Physics, 'Challenges of
Nuclear Structure', (INFN, University of Naples),Maiori, Italy, May (2001).
A. Ozawa: "New Magic Number, N = 16, near
the neutron magic number", Int. Conf. on Nuclear
Physics at Border Lines, (Messina University, Fondazione Bonino-Pulejo Messina), Lipari, Italy, May(2001).
Y. Mochizuki: "Element genesis: Solving the mystery(video presentation and interpretation) (invited)",Int. Symp. on Nuclear Astrophysics (NAP 2001),
Darmstadt, Germany, May (2001).
S. Fujii: "YN interactions and spin-orbit splittings in A
hypernuclei", KEK Theory Seminar, Tsukuba, May(2001).
S. Fujii: "A study of A hypernuclear structure withunitary-model-operator approach", Nuclear Theory
Seminar at University of Tsukuba, Tsukuba, May(2001) .
Y. Mochizuki: "Element genesis: Solving the mystery (video presentation and interpretation)", Seminar at Max-Planck-Institut fuer Astronomie, Heidelberg, Germany, May (2001).
N. Shimizu: "Quadrupole collective states in theMonte Carlo shell model", NATO Advanced Research Workshop on the Nuclear Many-Body Problem 2001, Pula, Croatia, June (2001).
Y. Mochizuki: "Microscopic nuclear rod model forthe origin of neutron star glitches" , Nuclear Physics
Seminar at RCNP of Osaka University, Osaka, June
(2001).
S. Fujii: "YN interactions and spin-orbit splittings in
A hypernuclei", Nuclear Physics Seminar at Tokyo
Institute of Technology, Tokyo, June (2001).
H. Sakai, T. Wakui, M. Hatano, A. Tamii, and T.
Uesaka: "Spin polarized solid proton target for experiments by the radio-isotope beam", 3rd Int. Conf.
on Exotic Nuclei and Atomic Masses (enam 2001),(University of Jyvaskyla) , Hameenlinna, Finland,
July- Aug. (2001) .
H. Sakai, K. Sekiguchi, Y. Maeda, W. Glockle,
M. B. Greenfield, K. Hatanaka, M. Hatano, D.
Hirooka, H. Kamada, J. Kamiya, H. Kato, T.
Ohnishi, H. Okamura, J. Rapaport, T. Saito, N.
Sakamoto, S. Sakoda, Y. Sato, K. Suda, A. Tamii, N.
Uchigashima, T. Uesaka, T. Wakasa, H. Wit ala, andK. Yakou: "Clear signature of three-nucleon force effects via the precise measurements of ap and rid scatterings", Int. Nuclear Physics Conf. (INPC2001),(Berkeley National Laboratory), Berkeley, USA,
July- Aug. (2001).
Y. Mochizuki: "Electron capture beta-decay underultra-high pressures" , Nuclear Physics Seminar at
Kyushu University, Fukuoka, July (2001).
S. Fujii: "Unitary-model-operator approach to A hypernuclei" , Nuclear Theory Seminar at University ofTokyo, Tokyo, July (2001).
Y. Mochizuki: "Microscopic nuclear rod model for theorigin of neutron star glitches" , Nuclear and Statis-

tics Physics Seminar at Nihon University, Tokyo,
July (2001).
Y. Mochizuki: "The origin of elements and life in theuniverse (invited)", Atomic Collision Soc. of Japan,
Tokyo, Aug. (2001).
A. Ozawa: "Nuclear size and related topics", BeijingInt. Summer School on Subatomics Physics, (Beijing
University), Beijing, China, Aug. (2001).
H. Sakai, T. Wakui, M. Hatano, A. Tamii, and T.
Uesaka: "Development of a spin polarized solid
proton target for experiments by the radio- isotope
beam" ,9th Workshop on High Energy Spin Physics(Spin-01): Joint Inst. for Nucl. Res. Int. Committee for Energy Spin Physics Symp., Dubna, Russia,
Aug. (2001).
H. Sakai: "Search for a three-nucleon force effects via
the polarization measurements on ap and rid scattering", 9th Workshop on High Energy Spin Physics(Spin-01): Joint Inst. for Nucl. Res. Int. Committee for Energy Spin Physics Symp., Dubna, Russia,
Aug. (2001).
K. Iida: "Color superconductivity: Approach fromweak coupling", Thermal quantum field theories andtheir application, (Yukawa Institute for Theoretical
Physics, Kyoto University), Kyoto, Aug. (2001).
K. Ishida: "Measurement of X-rays from muon-toalpha sticking in muon catalyzed fusion" , Meet. on
Basic Scieince using Muons and Muon Catalyzed Fusion, (Meson Science Users Association), Tsukuba,
Sept. (2001).
A. Kohama: "RIKEN efforts on proton scatteing withunstable nuclei", Workshop on Relativistic Description of Proton-Nucleus Scattering, (PCNP, Osaka
University), Osaka, Sept. (2001) .
H. Sakai: "Clear evidence of three-nucleon force effects in Nd scattering", 1st Joint Meet. of the Nuclear Physics Divisions of APS and JPS Hawaii 2001
(HAW01), Maui, USA, Oct. (2001).
Y. Mochizuki, I. Tanihata, Y. Yano, and R . N. Boyd:"Element genesis: Solving the mystery (video presentation) (invited)" , 1st Joint Meet. of the Nuclear Physics Divisions of APS and JPS Hawaii 2001
(HAW01), Maui, USA, Oct. (2001) .
H. En'yo: "Measurements of in-medium decay of vector mesons at KEK-PS", 1st Joint Meet. of the Nuclear Physics Divisions of APS and JPS Hawaii 2001
(HAW01), Maui, USA, Oct. (2001).
K. Ishida, K. Nagamine, T. Matsuzaki, Y. Matsuda,
N. Kawamura, S. Nakamura, M. Kato, H. Sugai,
M. Tanase, K. Kudo, N. Takeda, and G. H. Eaton:"Muon-catalyzed fusion experiments at RIKENRAL muon facility" , 1st Joint Meet . of the Nuclear Physics Divisions of APS and JPS Hawaii 2001
(HAW01), Maui, USA, Oct. (2001).
K. Sekiguchi, H. Sakai, A. Tamii, K. Yakou, S. Sakoda,
H. Kato, Y. Maeda, M. Hatano, T. Saito, N.
Uchigashima, H. Okamura, T. Uesaka, K. Suda, J.

339

Nishikawa, N. Sakamoto, T. Ohnishi, T. Wakasa,
Y. Sato, N. Kalantar-Nayestanaki, and K. Ermisch:"Search for three nucleon force effect via deuteronproton scattering" , 1st Joint Meet. of the Nuclear
Physics Divisions of APS and JPS Hawaii 2001
(HAW01), Maui, USA, Oct . (2001).
H. Koura, T. Tachibana, and T. Yoshida: "Estimationof alpha-decay half lives and fission barriers fromthe viewpoint of a new mass formula", Int. Conf. on
Nuclear Data for Science and Technology, (JAERI),
Tsukuba, Oct. (2001).
T. Matsuzaki, K. N agamine, K. Ishida, M. Kato,
H. Sugai, M. Tanase , and G. H. Eaton: "An insitu tritium-deuterium gas-purification system formuon catalyzed fusion experiments at the RIKENRAL Muon Facility", 6th Int. Conf. on Tritium Science and Technology (TRITIUM 2001), (JAERI),
Tsukuba, Nov. (2001).
M. Kato , T. !toh, H. Sugai, K. Yoshinori, H. Takumi,
N. Masataka, M. Tanase, T. Matsuzaki , K. Ishida,
and K. Nagamine: "Development of a compact
tritium gas recycling system", 6th Int. Conf. on
Tritium Science and Technology (TRITIUM 2001) ,(JAERI), Tsukuba, Nov. (2001).
A. Saito, S. Shimoura, S. Takeuchi, T. Motobayashi,
H. Akiyoshi , Y. Ando , N. Aoi, Z. Fulop, T. Gomi, Y.
Higurashi , M. Hirai , N. Iwasa, H. Iwasaki , Y. Iwata,
H. Kobayashi , M. Uesaka, 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", Int.
Symp. on Clustering Aspects of Quantum Manybody Systems, (Yukawa Institute for Theoretical
Physics , Kyoto University) , Kyoto, Nov. (2001).
K. !ida: "Phenomenology and sum rules in color superconducting quark matter", 6th APCTP WinterSchool/2nd Dense Matter School, Pohang, Korea,
Nov. (2001).
K. !ida, G. Watanabe, and K. Sato: "Formation of nuclear "pasta" in cold neutron star matter", Yukawa
Int. Seminar 2001 (YKIS01): Physics of Unstable
Nuclei, (Yukawa Institute for Theoretical Physics,
Kyoto University) , Kyoto, Nov. (2001).
A. Kohama, R. Seki, A. Arima, and S. Yamaji:"Model-independent determination of surface density distribution of unstable nuclei at radioactive beam facilities", Yukawa Int. Seminar 2001
(YKIS01): Physics of Unstable Nuclei , (Yukawa Institute for Theoretical Physics , Kyoto University),
Kyoto, Nov. (2001).
A. Saito, S. Shimoura, S. Takeuchi , T. Motobayashi,
H. Akiyoshi , Y. Ando , N. Aoi , Z. Fulop, T. Gomi ,Y. Higurashi , M. Hirai, N. Iwasa, H. Iwasaki,
Y. Iwata, H. Kobayashi , 11. Uesaka, Z. Liu, T.
Minemura, S. Ozawa, H. Sakurai, M. Serata, T.
Teranishi, K. Yamada, Y. Yanagisawa, and M.
Ishihara: "Molecular states in neutron-rich beryl-

340

lium isotopes", Yukawa Int. Seminar 2001 (YKIS01):
Physics of Unstable Nuclei , (Yukawa Institute for
Theoretical Physics, Kyoto University), Kyoto , Nov .
(2001).
Y. Mochizuki: "Intersection between meteorites andnucleosynthesis studies:', Earth and Planet Science
Seminar at University of Tokyo , Tokyo, Dec. (2001).
S. Fujii: "Shell-model calculations for ~7 0 and ~6 0
using microscopic effective interactions with degrees
of freedom of ~" , YITP Workshop on New Topics
for Strangeness Nuclear Physics, (Yukawa Institutefor Theoretical Physics , Kyoto University), Kyoto,
Dec. (2001).

3.

Atomic and solid-state physics

Y. Yoshida, Y. Kobayashi , F. Ambe , E. Vagi , X. Diao,
J. Nakamura, H. Hasslein, A. Feinauer, T . Grund ,A. Rock , and A. Seeger: "Direct observation of selfinterstitial motion in pure iron by 56Fe( d ,p )57 Fe inbeam Mossbauer spectroscopy", Int. Symp. of Diffusion in Materials 2000 (DIMAT2000), Paris, France,
July (2000).
Y. Yoshida, Y . Kobayashi, K. Hayakawa, K. Yukihira,F . Shimura, A. Yoshida, X. Diao, H. Ogawa, Y.
Yano, and F. Ambe: "In-beam Mossbauer study oninterstitial and substitutional 57Mn/ 57 Fe jumps inSi", Int. Symp. of Diffusion in Materials 2000 (DIMAT2000), Paris, France, July (2000).
Y. Kanai , Y. Iwai, D. Dumitriu, H. Masuda, Y.
Morishita, D. Murakoshi, and Y. Yamazaki: "Excited states produced by beam-capillary interaction" , 13th Int. Workshop on Inelastic Ion-Surface
Collisions, (Instituto Balseiro and Centro Atomico Bariloche) , San Carlos de Bariloche, Argentina,
Nov. (2000).
T. Hasegawa, A. Iwase , S. Ishino, Y. Chimi, N.
Ishikawa, T. Tobita, M. Suzuki, and T. Kambara:"Hardness of FeCu alloys irradiated with Ge V heavyions", Kyoto Daigaku Genshiro Jikkenjo Kenkyukai ,Kumatori, Jan . (2001 ).
T. Matsuzaki: "Pion target at ISIS facility", Muon
Science 2001 Symp. for KEK-JEARI Joint Project ,Tsukuba, Jan. (2001).
T . Ikeda: "Application to atomic physics", RIKEN
Symp. on Development and Application of Superconductor Radiation Detectors, Wako, Jan. (2001).
M. Wada: "Test experiment on the ion transport in gas
cell by RFion-guide", Workshop on Physics Applications of Medical Use Particle Accelerator, (National
Institute Radiological Sciences) , Chiba, Jan. (2001).
M. Wada: "Precision hyperfine structure spectroscopyof unstable nuclei", RIKEN Symp. on Studies on
Condensed Matter Physics , Atomic Physics , Hyperfine Interactions and Biomedical Sciences Using
RIKEN Accelerators , Wako, Feb. (2001).
Y. Nakai: "TOF analysis of fragment ion of C 60 byfast ion impact", RIKEN Symp. on Studies on Condensed Matter Physics, Atomic Physics, Hyperfine
Interactions and Biomedical Sciences Using RIKEN
Accelerators, Wako, Feb. (2001).
N. Ishikawa, Y. Chimi, A. Iwase, O. Michikami,
H. Wakana, T. Hashimoto, R. Neumann, and T.
Kambara: "Defect production process in oxide superconductors irradiated with high energy ions",
56th Ann. Meet. of Physical Soc. of Japan, Hachioji ,Mar. (2001).
N. Oshima, T. Kojima, D. Dumitriu, A. Mohri, H.
Oyama, Y. Kanai, T. Kambara, Y. Nakai, M. Wada,
M. Niigaki, and Y. Yamazaki: "Development of aslow positron beam using a rare gas solid moderator(III)", 56th Ann. Meet. of Physical Soc. of Japan ,Hachioji, Mar. (2001).
Y. Nakai , T. Kambara, A. Itoh, H. Tsuchida, and Y.
Yamazaki: "Ionization and fragmentation of C 60 byfast ion impact: Analysis of TOF spectrum profile
of fullerene-like fragment ions (II)", 56th Ann. Meet.
of Physical Soc. of Japan , Hachioji, Mar. (2001).
D. Murakoshi, N. Okabayashi, Y. Iwai, Y. Morishita,
Y. Nakai, Y. Kanai, H. Torii, K. Nishio, H. Masuda,
K. Komaki, and Y. Yamazaki: "Measurement ofcharge state distribution of Nq+ transmitted throughmicro-capillaries", 56th Ann. Meet. of Physical Soc.
of Japan, Hachioji, Mar. (2001).
A. Endo, H. Torii, K. Yoshiki Franzen, K. Komaki, andY. Yamazaki: "The development of a mini-EBIS using high-Tc superconductors (III)" ,56th Ann. Meet.
of Physical Soc. of Japan, Hachioji, Mar. (2001).
T. Ikeda, Y. Iwai, T. Oku, N. Oshima, C. Otani, H.
Oyama, H. Kato, Y. Kanai, K. Kawai , H. Sato,
H. Shimizu, Y. Takizawa, Y. Nakai, K. Nishio, H.
Masuda, H. Miyasaka, Y. Morishita, H. Watanabe,
and Y. Yamazaki: "X-ray spectroscopy of highly
charged ions using superconducting tunnel junctions(II)", 56th Ann. Meet. of Physical Soc. of Japan,
Hachioji, Mar. (2001).
Y. Iwai, R. Hutton, Y. Kanai, H. Oyama, K. Ando, H.
Masuda, K. Nishio, K. Komaki, and Y. Yamazaki:"High resolution soft X-ray spectroscopy of highly
charged ions through Au micro capillary target",56th Ann. Meet. of Physical Soc. of Japan, Hachioji,Mar. (2001) .
E. Vagi: "The analysis of the state of hydrogen dissolved in crystals by means of the nuclear reaction
channelling method", Symp. on the Role of Hydrogen in the Embrittlement of Structural Materials in
the Environmental Atmosphere, (The Iron and SteelInstitute of Japan), Tokyo, Mar. (2001).
T. Ikeda, Y. Nakai, C. Ohtani, H. Sato, Y. Kanai,
H. Oyama, Y. Takizawa, Y. Iwai, Y. Morishita,
N. Oshima, T. Oku, H. Shimizu, H. Watanabe, H.
Miyasaka, H. Kato, K. Kawai, Y. Yamazaki, H.
Akoh, M. Aoyagi, H. Nakagawa, S. Takada, and T.
Taino: "X-ray spectroscopy of highly charged ionsusing superconducting tunnel junctions", 8th Int.
Surperconductive Electronics Conf., Osaka, June
(2001) .
Y. Yamazaki: "Soft x-rays emitted in HCI-microcapillary interactions", 17th Int. Symp. on Ion-Atom
Collisions (IS lAC XVII), (Centro de Ciencias Fisicas), Baja California, Mexico, July (2001) .
Y. Yamazaki:"A micro-capillary target as ametastable hollow ion source", 19th Int. Conf. on
Atomic Collisions in Solids, Paris, France, July- Aug.
(2001).
T. Kambara, K. Kageyama, Y. Kanai, T. Kojima, Y.
Nakai, A. Yoneda, and Y. Yamazaki: "Elastic wave
from fast heavy-ion irradiation on solids" , 19th Int.
Conf. on Atomic Collisions in Solids, Paris, France,
July- Aug. (2001).
Y. Iwai , Y. Kanai, H. Oyama, K. Ando, H. Masuda, K.
Nishio, M. Nakao, T. Tamamura, K. Komaki, and Y.
Yamazaki: "High-resolution soft x-ray spectroscopyof 2.3 ke V lu N 7+ ions through a microcapillary target", 19th Int. Conf. on Atomic Collisions in Solids,
Paris, France, July- Aug. (2001).
T. Ikeda, Y . Nakai, C. Ohtani, H. Sato, H. Oyama,
Y. Kanai, Y. Iwai, Y. Morishita, N. Oshima, H.
Shimizu, and Y. Yamazaki: "X-ray detection using superconducting tunnel junctions in slow highly
charged ion collision with surface", 19th Int. Conf.
on Atomic Collisions in Solids, Paris, France, JulyAug. (2001).
M. Wada: "Development of an RF ion guide for trapping energetic radioactive nuclear ions", 2001 Workshop on Non-Neutral Plasmas, San Diego, USA,
July- Aug. (2001).
A. Mohri, T. Kojima, N. Ohshima, M. Niigaki, andY. Yamazaki: "System of slow highly charged ion
beam generation using a cold positron plasma trap
at RIKEN" , 2001 Workshop on Non-Neutral Plasmas, San Diego, USA, July- Aug. (2001).
M. Takekawa, Y. Itikawa, and I. Shimamura: "Elastic
scattering of electrons from carbonyl sulfide", 22ndInt. Conf. on Photonic, Electronic and Atomic Collisions (XXII ICPEAC) , (IUPAP and others), Santa
Fe, USA, July (2001).
M. Niigaki, N. Ohshima, T. Kojima, and Y. Yamazaki:"Extraction system for ultra-slow highly-charged
ions from a trap in a strong magnetic field", 22ndInt. Conf. on Photonic, Electronic and Atomic Collisions (XXII ICPEAC), (IUPAP and others), Santa
Fe, USA , July (2001).
H. Shimada, Y. Nakai, T. Kambara, K. Ando, H.
Oyama, and Y. Yamazaki: "Momentum distributions of highly charged noble gas ions produced byintense laser light", 22nd Int. Conf. on Photonic,
Electronic and Atomic Collisions (XXII ICPEAC) ,(IUPAP and others), Santa Fe, USA, July (2001).
"Production of heavy fragment ionsY. Nakai:(C 60 - 2n 1+ ,2+ ,3+) in collisions of C 60 with fast ions",341

22nd Int. Conf. on Photonic, Electronic and Atomic
Collisions (XXII ICPEAC) , (IUPAP and others) ,Santa Fe, USA, July (2001).
S. Sakaguti, K. Ohtsuki, and T . Watanabe: "Theoretical caluculation of double electron transfer processes
in collisions of He 2 + with Mg;' , 22nd Int. Conf. on
Photonic, Electronic and Atomic Collisions (XXIIICPEAC), (IUPAp and others), Santa Fe , USA, July
(2001) .
Y. Iwai , Y. Kanai , H. Oyama, K. Ando, H. Masuda, K.
Nishio, M. Nakao, T. Tamamura, K. Komaki, andY. Yamazaki: "X-ray measurement for 2.3 keY lu
15N7+ ions passing through Au and Ni microcapillary targets", 22nd Int. Conf. on Photonic,
Electronic and Atomic Collisions (XXII ICPEAC) ,(IUPAP and others), Santa Fe, USA, July (2001).
T. Ikeda, Y. Nakai, C. Ohtani, H. Sato, H. Oyama,
Y. Kanai , Y. Iwai, Y. Morishita, N. Oshima, H.
Shimizu, and Y. Yamazaki: "X-ray spectroscopy ofhighly charged ions using superconducting tunnel
junctions" , 22nd Int. Conf. on Photonic, Electronicand Atomic Collisions (XXII ICPEAC), (IUPAP
and others), Santa Fe, USA, July (2001).
Y. Nagashima, Y. Ito, A. Goto, and T. Hyoudo: "Detection of positron annihilation induced characteristic X-rays", 38th Ann . Meet. on Radioisotopes
and Radiation in the Physical Sciences and Industries , (Japan Radioisotope Association), Tokyo, July
(2001).
N. Oshima, T. Kojima, A. Mohri, M. Niigaki, T.
Kambara, Y. Kanai, Y. Nakai, H. Oyama, M. Wada,and Y. Yamazaki: "Study of a slow HCI production
technique using a positron cooling method", 38th
Ann. Meet. on Radioisotopes and Radiation in the
Physical Sciences and Industries , (Japan Radioisotope Association), Tokyo, July (2001) .
F. Saito, Y. Nagashima, T. Kurihara, Y. Ito , A. Goto,
and T. Hyoudo: "Tungsten mesh moderator for slow
positron beams", 38th Ann. Meet. on Radioisotopes
and Radiation in the Physical Sciences and Industries, (Japan Radioisotope Association) , Tokyo, July
(2001).
1. Shimamura:"Bound states of positron withmolecules", 11th Workshop on Low Energy Positronand Positronium Physics, (ICPEAC) , Santa Fe,
USA, Aug . (2001).
S. Sakaguti, K. Otsuki , and T. Watanabe: "Calculation of double electron transfer processes in collisionsof He 2 + with Mg", 26th Ann. Meet. of the Soc. for
Atomic Collision Research , Tokyo , Aug. (2001) .
M. Takekawa, Y. Itikawa, and I. Shimamura: "Elastic scattering of electrons from carbonyl sulfide",
26th Ann. Meet. of the Soc. for Atomic Collision
Research, Tokyo , Aug. (2001).
M. Hoshino , M. Kitajima, Y. Kanai, Y. Nakai, H.
Tanaka, and Y. Yamazaki: "Experimental studies for highly-charged-ion and atom collisions with342

crossed-beam technique", 26th Ann. Meet. of theSoc. for Atomic Collision Research, Tokyo, Aug.
(2001) .
T. Ikeda: "X-ray detection using superconducting tunnel junctions" , 26th Ann. Meet. of the Soc. for
Atomic Collision Research , Tokyo, Aug. (2001).
T. Ikeda, Y. Nakai, C. Ohtani, H. Sato, H. Oyama,
Y. Kanai, Y. Takizawa, Y. lwai, Y. Morishita, T.
Oku, N. Ohshima, H. Watanabe, H. Miyasaka, K.
Kawai , H. Kato, Y. Yamazaki, and H. Shimizu: "Xray spectroscopy in atomic collision experiment using superconducting tunnel junctions", 5th European Conf. on Applied Superconductivity (EUCAS2001), (DEFU and others), Copenhagen, Denmark,Aug. (2001).
K. Ishioka, M. Hase, K. Ushida, and M. Kitajima:"Coherent acoustic phonon-defect scattering ingraphite", 10th Int. Conf. on Phonon Scattering in
Condensed Matter, Hanover, USA , Aug. (2001).
N. Ohshima, T. Kojima, A. Mohri, M. Niigaki, H.
Oyama, Y. Kanai, T. Kambara, Y. Nakai, M. Wada,
K. Komaki, and Y. Yamazaki: "Development ofa slow positron source for cooling highly chargedions", 2001 Fall Meet. of the Physical Soc. of Japan ,Tokushima, Sept. (2001).
A. Mohri, T. Kojima, N. Ohshima, M. Niigaki, and Y.
Yamazaki: "Dynamics during positron beam injection into an electron plasma", 2001 Fall Meet. of the
Physical Soc. of Japan , Tokushima, Sept. (2001).
T. Kambara, K. Kageyama, Y. Kanai, T . Kojima,
Y. Nakai, A. Yoneda, and Y. Yamazaki: "Elastic
wave generation in solid by irradiation of fast heavyions", 2001 Fall Meet. of the Physical Soc. of Japan ,Tokushima, Sept. (2001).
Y. Iwai, Y. Kanai , H. Oyama, K. Ando, H. Masuda,
K. Nishio , M. Nakao , T. Tamamura, K. Komaki,
and Y. Yamazaki: "High resolution soft X-ray spectroscopy of highly charged ions through Au microcapillary target II", 2001 Fall Meet. of the PhysicalSoc. of Japan, Tokushima, Sept. (2001).
T. Kojima, N. Ohshima, M. Niigaki, A. Mohri, and Y.
Yamazaki: "RIKEN positron-MCI trap II: confinement of electrons positrons" , 2001 Fall Meet. of the
Physical Soc. of Japan , Tokushima, Sept . (2001).
M. Wada: "Slow and trapped RNB from a projectile fragment separator and their applications", 4th
Italy-Japan Symp. on Heavy Ion Physics, Wako,
Sept. (2001).
F. Saito, Y. Nagashima, 1. Wei, Y. Ito, A. Goto,
and T. Hyoudo: "High-efficiency positron moderator with electro-polished tungsten meshes", 9th Int.
Workshop on Positron Beam Techniques for Solids
and Surfaces, Dresden, Germany, Sept. (2001).
F. Saito, N. Suzuki, Y. Ito, A. Goto , T. Kurihara,
Y. Nagashima, and T. Hyoudo: "Development andapplication of spin polarized positron beams" , Specialist Research Meet. on Positron Beam Techniques

and Their Applications, Kumatori, Oct. (2001).
Y. Nagashima, T. Hyoudo, Y. Ito, and A. Goto:"Search for positron annihilation induced charateristic X-rays", Specialist Research Meet. on Positron
Beam Techniques and Their Applications, Osaka,
Oct. (2001).
M. Hase, K. Ishioka, K. Ushida, and M. Kitajima:"Dephasing of coherent THz phonons in bismuth
studied by femtosecond pump-probe technique", 6thInt. Conf. on Laser Ablation (COLA '01), Tsukuba,
Oct. (2001).
K. Ishioka, M. Hase, K. Ushida, and M. Kitajima:"Femtosecond carrier and phonon dynamics in defective graphite and GaAs", 6th Int. Conf. on Laser
Ablation (COLA '01), Tsukuba, Oct. (2001).
4.

Radiochemistry, radiation chemistry, and radiation biology

S. Enomoto: "Dynamics of various trace elements inthe body: Approach of physiological metabolism using multitracer technique", 49th Symp. on Coordination Chemistry of Japan, Sapporo, Sept. (1999).
Y. Oura, S. Enomoto, and H. Nakahara: "Applicationof prompt I ray analysis to rats" , 43rd Meet. of Radiation Chemical Soc. of Japan, (The Japan Societyof Nuclear and Radiochemical Sciences) , Tsuku ba,
Oct. (1999).
K. Matsumoto, S. Ueda, H. Urata, K. Endo, R.
Hirunuma, S. Enomoto, S. Ambe, and F. Ambe:"Distribution of elements in cell fraction of the liverof Se-deficient rats", 43rd Meet. of Radiation Chemical Soc. of Japan, (The Japan Society of Nuclear andRadiochemical Sciences), Tsukuba, Oct. (1999).
T. Ozaki, Y. Kawamura, S. Ambe, S. Enomoto, Y.
Minai, and Y. Makide: "Study on the antagonism
between elements and uptake of vatious elements inplants", 43rd Meet. of Radiation Chemical Soc. ofJapan, (The Japan Society of Nuclear and Radiochemical Sciences), Tsuku ba, Oct. (1999).
T. Ohyama, T. Yoshida, M. Iwama, M. Yanaga, M.
Noguchi, T. Omori, R. Hirunuma, and S. Enomoto:"U ptake of trace elements in Zn-deficient mice" ,43rd Meet. of Radiation Chemical Soc. of Japan,(The Japan Society of Nuclear and Radiochemical
Sciences) , Tsukuba, Oct. (1999).
T. Taroda, R. Amano, H. Sakamoto, and S. Enomoto:"Bio-behavior of multitracer in the young mice",
43rd Meet. of Radiation Chemical Soc. of Japan,(The Japan Society of Nuclear and Radiochemical
Sciences), Tsuku ba, Oct. (1999).
S. Enomoto, Y. Kawamura, Y. Komatsu, and R.
Amano: "Separation of metal ions for multitracer
products", 16th Int. Symp. on Separation Chemistry, (National Institute of Research in Inorganic
Materials), Tsukuba, Nov. (1999).
S. Yoshida, M. Masuda, M. Nakayama, M. Yamasaki,

S. Enomoto, and H. Morikawa: "Study on the absorption of mineral in the digestive organs", 19th
Ann. Meet . Japanese Society of Magnesium Research, Hiroshima, Nov. (1999).
S. Enomoto and R. Hirunuma: "Fetoplacental transport and metabolism of various trace elements: development of the multitracer technique", RIKEN
Symp. on Bio-Trace Elements '99.12, Wako, Dec.
(1999).
T. Taroda, R. Amano, H. Sakamoto, and S. Enomoto:"Biobehavior of multitracers in the brain of youngmice", RIKEN Symp. on Bio-Trace Elements '99.12,
Wako, Dec. (1999).
K. Matsumoto, S. Ueda, H. Urata, K. Endo, R.
Hirunuma, and S. Enomoto: "Distribution of traceelements in cell fraction of selenium-deficient rat
liver", RIKEN Symp. on Bio-Trace Elements '99.12,
Wako, Dec. (1999).
K. Igarashi, Y. Nakanishi, S. Kimura, R. Hirunuma,
and S. Enomoto: "Effect of NaFeEDTA on thebiodistribution of trace elements in rats", RIKEN
Symp. on Bio-Trace Elements '99.12, Wako, Dec.
(1999).
Y. Shiobara, Y. Ogura, K. Suzuki, R. Hirunuma, and
S. Enomoto: "Effect of dietary selenium species
and dose on the organ distribution of multitracer" ,RIKEN Symp. on Bio-Trace Elements '99.12, Wako ,Dec. (1999).
H. Suzuki, H. Kumagaya, K. Oohashi, and S.
Enomoto: "Influence of Arbuscular mycorrhizal hyphae on absorption of trace elements in plants",
RIKEN Symp. on Bio-Trace Elements '99.12, Wako,
Dec. (1999).
Y. Kawamura, T. Ozaki, S. Enomoto, and R. Amano:"Synthesis of organometallic complex using the multitracer technique" , RIKEN Symp. on Bio-Trace Elements '99.12, Wako, Dec. (1999) .
T. Yanagiya, S. Enomoto, N. Imura, S. Himeno, and Y.
Kondo: "The role of transport system for manganesein cadmium resistance" , RIKEN Symp. on Bio-Trace
Elements '99.12 , Wako, Dec. (1999).
T. Ohyama, T. Yoshida, H. Maetsu, M. Iwama, M.
Yanaga, M. Noguchi, T. Omori, R. Hirunuma, and
S. Enomoto: "Uptake of trace elements in Zndeficient mice" , RIKEN Symp. on Bio-Trace Elements '99.12, Wako, Dec. (1999) .
H. Tamano, S. Enomoto, E. Igasaki, N. Oku, N. Itoh,K. Tanaka, and A. Takeda: "Study on hepatic zincmetallothionein elevated after subcataneous inj ection of tumor cells", 120th Ann. Meet. of the Pharmaceutical Soc. of Japan, Gifu, lVlar. (2000) .
T. Yanagiya, N. Imura, S. Enomoto, Y. Kondo, and
S. Himeno: "Suppression of Mn transport system
in Cd-resistant cell live", 120th Ann. Meet. of thePharmaceutical Soc. of Japan, Gifu, Mar. (2000).
R. Hirunuma, H. Tamano, Y. Kawamura, Y. Yano,and S. Enomoto: "Transfer of various elements from343

the placenta to the fetus by using the multitracer
technique", 120th Ann. Meet. of the Pharmaceutical
Soc. of Japan, Gifu, Mar. (2000).
K. Matsumoto, S. Ueda, H. Urata, K. Endo, R.
Hirunuma, and S. Enomoto: "Behavior of trace elements in the liver of Se-deficient rats", 120th Ann.
Meet. of the Pharmaceutical Soc. of Japan, Gifu ,Mar. (2000).
S. Yoshida, M. Masuda, M. Nakayama, M. Yamasaki ,S. Enomoto, and H. Morikawa: "Study on the intestinal absorption of mineral", 52h Ann. Meet.
of Japan Soc. of Obstetrics and Gynecology,
Tokushima, Apr. (2000).
R. Hirunuma, K. Matsumoto , S. Enomoto , and K.
Endo: "Behavior of metals in cell fraction ofselenium-deficient rat liver", 10th Symp. on theRole of Metals in Biological Reaction , Biology, andMedicine , (The Pharmaceutical Society of Japan) ,Tokyo, May (2000).
S. Enomoto, R. Hirunuma, H. Tamano, Y. Kawamura,and Y. Yano: "Biological transport of the various
trace elements in the pregnant rats and fetus", 6thInt. Symp. on Metal Ions in Biology and Medicine ,(Armed Forces Institute of Pathology) , Puerto Rico ,USA , May (2000).
H. Sakurai, H. Yasui , T. Takino, S. Enomoto, and R.
Hirunuma: "Treatment of diabetes by vanadium",
11 th Ann. Meet. of the Japan Soc. for Biomedical
Research on Trace Elements, Nagoya, June (2000).
S. Enomoto, F. Ambe, and Y. Yano: "Advancementof manufacture technology of multitracer and applied research of multitracer", 13th Seminar on Ion
Exchange, (The Japan Society on Ion Exchange) ,Tokyo, July (2000).
T. Abe, T. Matsuyama, N. Fukunishi, S. Sekido , and S.
Yoshida: "An effective mutation method for plants
using heavy-ion beams (II)" , 18th Ann. Meet. andSymp. of Japanese Soc. for Plant Cell and Molecular
Biology, Shizuoka, July (2000).
S. Yoshida, M. Masuda, M. Nakayama, M. Yamasaki,
S. Enomoto , and H. Morikawa: "Study on the intestinal absorption of divalent cations", 24th Ann.
Meet. of the Japan Soc. of Women's Nutrition andMetabolism, Nagoya, Aug. (2000).
T. Ohyama, M. Yanaga, T. Yoshida, H. Maetsu , M.
Noguchi , H. Suganuma, T . Omori , R. Hirunuma,
and S. Enomoto: "Characteristic behavior of metals
in Zn-deficient mice" , 44th Symp. on Radiochemistry, (The Japan Society of Nuclear and Radiochemical Sciences), Kobe, Sept. (2000).
T. Taroda, Y. Yabushita, R. Amano, T. Nakanishi , and
S. Enomoto: "Concentration and uptake-behaviorof trace elements in the brain of young mice using
instrumental neutron activation analysis and multitracer technique", 44th Symp. on Radiochemistry,(The Japan Society of Nuclear and Radiochemical
Sciences) , Kobe, Sept. (2000).

344

S. Shibata, S. Enomoto, and R . Hirunuma: "Preliminary study of amalgam extracting method of multitracer production", 44th Symp. on Radiochemistry,(The Japan Society of Nuclear and Radiochemical
Sciences) , Kobe, Sept. (2000) .
Y. Yabushita, Y. Kanayama, T. Kimura, T. Taroda, K.
Washiyama, R. Amano, and S. Enomoto: "Elementelement interaction in mouse brain under deficientand excessive state of an essential trace element using multitracer technique" , 44th Symp. on Radiochemistry, (The Japan Society of Nuclear and Radiochemical Sciences) , Kobe, Sept. (2000).
S. Yoshida, M. Masuda, M. Yamasaki, M. Nakayama,
H. Morikawa, R. Hirunuma, and S. Enomoto:"Study on the absorption of divalent cations in
the digestive organs", 9th Int. Magnesium Symp.
(MAG2000) , (The International Society for theDevelopment of Research on Magnesium) , Vichy,
France, Sept. (2000).
Y. Gono, Y. Yang, S. Motomura, S. Enomoto, andY. Yano: "Position identification of gamma-ray
sources", Nuclear Science Symp. and Medical Imaging Conf. , (IEEE), Lyon, France, Oct. (2000).
Y. Kobayashi , Y. Yoshida, A. Yoshida, K. Kubo , Y.
Yamada, K. Hayakawa, K. Yukihira, H. Ogawa, H.
Ueno, K. Asahi , and F. Ambe: "In-beam Mossbauer
study of 57Fe using a secondary 57Mn beam and ion
implantation", Int. Symp. on Perspectives in Physics
with Radioactive Isotope Beams 2000 (RIBOO),(RIKEN and Center for Nuclear Study, Universityof Tokyo) , Hayama, Nov. (2000).
S. Yoshida, M. Masuda, M. Nakayama, M. Yamasaki,
S. Enomoto, and H. Morikawa: "Study on the intestinal absorption of divalent cations in the digestive organs", 37th Ann. Meet. of Japanese Societyof Applied Physiology, Nara, Nov. (2000).
S. Enomoto: "Biological transport of the various traceelements in pregnant rats and tetuses" , Int. Chemical Congr. of Pacific Basin Soc. (PACIFICHEM
2000) , Honolulu , USA , Dec. (2000).
K. Matsumoto , R. Hirunuma, S. Enomoto, and K.
Endo: "Contents and uptakes of Mn , Fe , Co , Zn ,and Se in Se-deficient rat liver cell-fractions by instrumental neutron activation analysis and multitracer technique", Int. Chemical Congr. of PacificBasin Soc. (PACIFICHEM 2000) , Honolulu, USA ,Dec. (2000).
T. Ohyama, T. Yoshida, M. Yanaga, M. Noguchi ,H. Suganuma, T. Omori , R. Hirunuma, and S.
Enomoto: "Effects of Zn-deficiency to uptakes oftrace elements", Int. Chemical Congr. of PacificBasin Soc. (PACIFICHEM 2000), Honolulu, USA ,Dec. (2000).
Y. Kobayashi, K. Kubo, Y. Yamada, A. Yoshida,
H. Ogawa, K. Asahi , and F. Ambe: "In-beam
Mossbauer studies of 57Fe ions arising from 57Mn
implanted into KMn04 ", Int. Chemical Congr. ofPacific Basin Soc. (PACIFICHEM 2000), Honolulu,
USA, Dec. (2000).
K . Matsumoto, N. Sotogaku, R. Hirunuma, S.
Enomoto, S. Ambe, and F. Ambe: "Multitracer
study on complex formation of lanthanide ions withbovine serum albumin and transferrin" , Int. Chemical Congr. of Pacific Basin Soc. (PACIFICHEM
2000), Honolulu, USA , Dec. (2000).
Y. Kawamura, S. Komatsu, S. Umetani , S. Tsurubou ,A. Hokura, S. Enomoto , and R. Amano: "Separation of alkaline earth metal ions by solvent extraction method combined with inorganic ion-exchangesystem", Int. Chemical Congr. of Pacific Basin Soc.
(PACIFICHEM 2000), Honolulu, USA, Dec. (2000).
A. Nakayama, H. Yasui , R. Hirunuma, S. Enomoto ,and H. Sakurai: "Distribution of multitracer elements in rats partially hepatectomized" , RIKEN
Symp. on Bio-Trace Elements 2000 , Wako , Dec.
(2000).
Y. Yabushita, Y. Kanayama, T. Taroda, K.
Washiyama, R. Amano, and S. Enomoto: "Elementelement interaction in mouse brain under deficientand excessive state of an essential trace element",
RIKEN Symp. on Bio-Trace Elements 2000 , Wako ,Dec. (2000).
T. Taroda, Y. Yabushita, Y. Kanayama, R. Amano,
and S. Enomoto: "Elemental concentration an
tracer uptake behavior of manganese, zinc and selenium in the brain of normal mice during development", RIKEN Symp. on Bio-Trace Elements 2000 ,Wako, Dec. (2000).
S. Enomoto and R. Hirunuma: "Fetoplacental transport of the various trace elements in the pregnant rat
by using the multitracer technique" , RIKEN Symp.
on Bio-Trace Elements 2000, Wako, Dec. (2000).
J. Furukawa, R. Hirunuma, S. Enomoto , and T.
Nakanishi: "Measurement of the affinity for binding of various metal elements with plant apoplast
protein in root tip", RIKEN Symp. on Bio-Trace
Elements 2000 , Wako, Dec. (2000).
S. Shibata, S. Enomoto, and R. Hirunuma: "Preliminary study of amalgan extracting method for production of multitracer" , RIKEN Symp. on Bio-Trace
Elements 2000 , Wako , Dec. (2000).
T . Yanagiya, N. Imura, S. Enomoto, Y. Kondo, and
S. Himeno: "Reduction of cadmium toxicity by
manganese", RIKEN Symp. on Bio-Trace Elements
2000, Wako, Dec. (2000).
T. Ohyama, T. Yoshida, H. Maet su , M. Noguchi , H.
Suganuma, R. Hirunuma, S. Enomoto, M. Yanaga,
and T. Omori: "Specific cobalt metabolism underZn-deficient state" , RIKEN Symp. on Bio-Trace Elements 2000 , '\Tako , Dec. (2000).
S. Yoshida, M. Masuda, M. Yamasaki, M. Nakayama,
H. Morikawa, R. Hirunuma, and S. Enomoto:"Study on the absorption of divalent cations in thedigestive organs", RIKEN Symp. on Bio-Trace Ele-ments 2000 , Wako, Dec. (2000).
T. Nabekura, T. Minami, R. Hirunuma, S. Enomoto ,and Y. Ito: "Uptake of trace elements in adult andsuckling rat lens", RIKEN Symp. on Bio-Trace Elements 2000 , Wako, Dec. (2000).
Y . Oura, S. Enomoto, and H. Nakahara: "Applicationof prompt gamma ray analysis to biological sampIes", RIKEN Symp. on Bio-Trace Elements 2000 ,Wako, Dec. (2000).
R. Hirunuma and S. Enomoto: "Application of themultitracer technique: Effect of selenium on the distribution of trace elements in rat" , RIKEN Symp.
on Bio-Trace Elements 2000 , Wako, Dec. (2000).
K. Igarashi, A. Sasaki, Y. Yoda, H. Inage , Y.
Nakanishi, R. Hirunuma, S. Enomoto , and S.
Kimura: "Effect of sodium iron EDTA on the absorption and the distribution of trace elements inanemic rats" , RIKEN Symp. on Bio-Trace Elements
2000, Wako , Dec. (2000).
K. Matsumoto, R. Hirunuma, S. Enomoto , and K .
Endo: "Evaluation of in vivo oxidative stress in liverof selenium-deficient rat" , RIKEN Symp. on BioTrace Elements 2000 , Wako , Dec. (2000).
H. Suzuki , H. Kumagaya, F. Mori, K. Sakamoto, K.
Inubushi, and S. Enomoto: "Influence of lanthanumon the uptake of various elements by marigold" ,RIKEN Symp. on Bio-Trace Elements 2000 , Wako,
Dec. (2000).
R. Amano, T. Tsuji, T. Taroda, K. Washiyama, and S.
Enomoto: "Isolation and purification of 95mTc and
96Tc in the distilled waste fraction during chemical
separation of multitracer from Ag target" , RIKEN
Symp. on Bio-Trace Elements 2000 , Wako , Dec.
(2000).
C. Egawa, Y. Takahashi, S. Enomoto, R. Hirunuma,
and H. Shimizu: "Multitracer study on the diffusionof various ions through the porewater of granite",
RIKEN Symp. on Bio-Trace Elements 2000 , Wako,
Dec. (2000).
H. Tamano , S. Enomoto, R. Hirunuma, and A. Takeda:"u ptake of radioactive elements in rat brain tumor" ,RIKEN Symp. on Bio-Trace Elements 2000, Wako ,Dec. (2000).
F. Yatagai, T. Nohmi , and M. Kusakabe: "Mutationinduction by heavy-ion of gpt6. transgenic mice: effect of p53 gene knockout", 17th Symp. on Space
Utilization Research, (The Institute of Space andAstronautical Science), Sagamihara, Jan. (2001).
R . Hirunuma and S. Enomoto: "Analysis of metals
in various organs of Se-deficient rats", 9th Symp. on
Research Center for Nuclear Science and Technology
in University of Tokyo , Tokyo, Jan. (2001).
Y. Kobayashi: "Applications of 57Mn/ 57 Fe Mossbauer
spectroscopy to chemistry" , RIKEN Symp. on Studies on Condensed Matter Physics, Atomic Physics ,Hyperfine Interactions and Biomedical Sciences Using RIKEN Accelerators, Wako, Feb. (2001).

345

T. Matsuyama, T. Abe, R. Kiuchi , T. Nakano, T.
Asami , and S. Yoshida: "Profiling of RLGS patterns
using DNA sequences in Arabidopsis genomes", 2001
Ann. Meet. of Japan Soc. for Bioscience: Biotechnology and Agrochemistry, Kyoto, Mar. (2001).
Y. Konomi , T. Abe, K. Sekino, H. Koyanagi, Y.
Yamada, F. Sugawara, and S. Yoshida: "Benzobicyclon resistance using beavy ion-beam mutagenesis",26th Ann. Meet. of Pesticide Science Soc. of Japan,
Sakai, Mar. (2001).
M. Hase, K. Ishioka, M. Kitajima, and K. Ushida: "Effect of lattice defects on generation and relaxationof coherent phonons in n-GaAs", 56th Ann. Meet.
of Physical Soc. of Japan, Hachioji , Mar. (2001).
K. Ishioka, M. Hase, M. Kitajima, and K. Ushida:"Effect of defects on carrier and phonon dynamics
in graphite", 56th Ann. Meet. of Physical Soc. ofJapan, Hachioji, Mar. (2001).
Y. Yoshida, A. Saeki, T. Kozawa, S. Seki, K. Ushida,
and S. Tagawa: "Geminate ion recombination in liquid alkane studied by subpicosecond pulse radiolysis", 79th Natl. Meet. of the Chemical Soc. of Japan,
Kobe, Mar. (2001).
K. Takahashi, S. Enomoto, T. Minami, T. Nakagawa,
M. Kidera, and Y. Yano: "Chemical and mineralogical studies on natural cinnabar ore and the samples
from ancient tomb", RIKEN Symp. on Research for
Cinnabar from Ancient Tomb, Wako, Mar. (2001).
M. Kidera, T. Nakagawa, S. Enomoto, K. Takahashi ,T. Minami, M. Fujimaki, E. Ikezawa, O. Kamigaito,
M. Kase, A. Goto, and Y. Yano: "Trace elements
analysis and isotope search using the electron cyclotron resonance ion source", RIKEN Symp. on Research for Cinnabar from Ancient Tomb , Wako, Mar.
(2001).
H. Tamano, M. Hirate , R. Hirunuma, S. Enomoto, N.
Oku , and A. Takeda: "Behavior of bio-trace elements in El (epilepsy) rat brain", 121st Ann. Meet.
of the Pharmaceutical Soc. of Japan, Sapporo, Mar.
(2001) .
T. Nabekura, T. Minami, R. Hirunuma, S. Enomoto,and Y. Ito: "Behavior of uptake of bio-trace elements in adult and suckling rat lenses", 121st Ann.
Meet. of the Pharmaceutical Soc. of Japan , Sapporo,
Mar. (2001).
H. Tamano, M. Hirate, R. Hirunuma, S. Enomoto, N.
Oku , and A. Takeda: "Distribution of trace elementsin the brain of El (epilepsy) mice", 121st Ann. Meet.
of the Pharmaceutical Soc. of Japan, Sapporo, Mar.
(2001).
R. Hirunuma and S. Enomoto: "Study of the uptakeof trace elements in Se-excessive rats using the multitracer technique", 121st Ann. Meet. of the Pharmaceutical Soc. of Japan, Sapporo, Mar. (2001) .
K. Matsumoto, I. Ui, R. Hirunuma, S. Enomoto, and
K. Endo: "In vivo evaluation of behavior of biotrace elements in rats using the multitracer tech-

346

nique", 121st Ann. Meet. of the Pharmaceutical Soc.
of Japan, Sapporo, Mar. (2001).
M. Kitajima, M. Hase, K. Ishioka, and K. Ushida:"Coherent phonons and the effect of lattice defects insolids", 48th Spring Meet. 2001 of The Japan Soc.
of Applied Physics and Related Soc. , Tokyo, Mar.
(2001).
Y. Kobayashi: "Exotic valence states of 57Fe arisingfrom 57Mn", Workshop on Science with Low-Energy
Short-lived Nuclear Beam, (KEK) , Tsukuba, Mar.
(2001) .
M. Hamatani, T. Abe, K. Miyoshi, M. Yamamoto,and S. Yoshida: "Flower mutants of dahlia (Dahlia
pinnata Cav.) induced by heavy-ion beams", 99th
Congr. of the Breeding Soc. of Japan , Fujisawa, Apr.
(2001).
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 cell", 13th Symp. on
Microdosimetry (MICROS 2001), (INFN-Laboratori
N azionali di Legnaro and Sezione INFN di Milano),Stresa, Italy, May-June (2001).
F. Yatagai, S. Morimoto, S. Goto, T. Kato, M. Honma,
and F. Hanaoka: "Mutation induction in humancell after low-dose X-ray exposure", 13th Symp. on
Microdosimetry (MICROS 2001), (INFN -Laboratori
N azionali di Legnaro and Sezione INFN di Milano),Stresa, Italy, May- June (2001).
S. Enomoto: "Research proposal for RIBF Projectfrom viewpoint of Multitrace Technology", Nuclear
Crossover Research: 2001 Workshop on Radiation Damage Repair and Multitracer Application,
Kanazawa, May (2001).
F. Yatagai: "Research proposal for RIBF Projectfrom viewpoint of Radiation Biology Effects", Nuclear Crossover Research: 2001 Workshop on Radiation Damage Repair and Multitracer Application,
Kanazawa, May (2001).
R. Hirunuma and S. Enomoto: "Study of the uptake ofbio-trace elements in Se-excessive rats", 18th Symp.
of Trace Nutrients Research, Kyoto, May (2001).
K. Ishioka, M. Hase, K. Ushida, and M. Kitajima:"Coherent acoustic phonon in ion-irradiatedgraphite", 10th Int. Conf. on Time-resolved
Vibrational Spectroscopy, Okazaki, May (2001) .
T. Abe , K. Sekino, T. Matsuyama, Y. Konomi, H.
Koyanagi, Y. Yamada, F. Sugawara, and S. Yoshida:"Heavy ion-beam mutagenesis for benzobicyclon resistant plants", 17th Int. Conf. on Plant Growth
Substances (IPGSA 2001) , (Mendel University ofAgriculture and Forestry) , Brno, Czech Republic ,June (2001).
F. Yatagai , S. Morimoto, T. Kato, M. Honma,
and F. Hanaoka: "Change in pattern of LOH
on chromosome 17q after 10 cGy of X-ray exposure", DOE/NASA Radiation Investigators ' Work-

shop, Washington, D.C., USA, June (2001).
K. Suzuki, Y. Yomo, T. Abe, Y. Katsumoto, S.
Yoshida, and T. Kusumi: "Isolation of sterile mutants of Verbena hybrida using heavy-ion beams irradiation", 19th Ann. Meet. and Symp. of Japanese
Soc. for Plant Cell and Molecular Biology, Tokyo,
July (2001).
K. Miyazaki, K . Suzuki, T. Abe, S. Yoshida, and T.
Kusumi: "Isolation of variegated mutants of Petunia
hybrida using heavy-ion beams irradiation", 19th
Ann . Meet. and Symp. of Japanese Soc. for Plant
Cell and Molecular Biology, Tokyo, July (2001).
T. Abe, T . Matsuyama, S. Yoshida, N. Fukunishi, andY. Yano: "New method of plant mutagenesis using
heavy-ion beams", 19th Ann . Meet . and Symp. ofJapanese Soc. for Plant Cell and Molecular Biology,
Tokyo, July (2001).
T. Matsuyama, T. Abe, K . Koike, T. Ebisuzaki, andS. Yoshida: "Analysis of mutants indused by radiation using RLGS-simulation pattern", 19th Ann.
Meet. and Symp. of Japanese Soc. of Plant Cell andMolecular Biology, Tokyo, July (2001).
T. Abe and N. Fukunishi: "Ion-beam mutagenesis
research in RARF" , 40th Gamma Field Symp.,
Tsukuba, July (2001).
S. Goto, S. Morimoto, T. Kurobe, M. Izumi, N.
Fukunishi, M. Watanabe, and F. Yatagai: "Delayed
cell-cycle arrest following heavy-ion exposure", Int.
Symp. on Radiation and Homeostasis, (Health Research Foundation), Kyoto, July (2001).
T. Ohyama, H. Maetsu, M. Noguchi, H. Suganuma, R.
Hirunuma, S. Enomoto, M. Yanaga, and T. Omori:"Abnormal metabolisms in trace elements under
the Zn-deficient condition", 12th Ann. Meet . of theJapan Soc. for Biomedical Research on Trace Elements, Tokyo, July (2001).
S. Enomoto, T. Yanagiya, R. Hirunuma, and R.
Amano: "Multitracer gamma-ray emission imaging(MT-GEI): A new detection system for multitracer",
12th Ann. Meet. of the Japan Soc. for Biomedical
Research on Trace Elements, Tokyo, July (2001).
R. Hirunuma and S. Enomoto: "Study on development of new trace elements analytical system using the electron cyclotron resonance ion source andheavy ion linear accelerator", 12th Ann. Meet. of
the Japan Soc. for Biomedical Research on Trace
Elements, Tokyo, July (2001).
H. Tamano, A. Takeda, N. Oku, S. Enomoto, and
R. Hirunuma: "U ptake of various elements in rat
brain tumor" , 12th Ann. Meet. of the Japan Soc.
for Biomedical Research on Trace Elements , Tokyo,
July (2001).
J. Furukawa, R. Hirunuma, S. Enomoto, and T.
Nakanishi: "A study of multitracer to measure thebinding affinity to an apoplast protein of the rootin the presence of AI", IUPAC Int. Congr. on Analytical Sciences 2001, (Japan Society for Analytical

Chemistry), Tokyo, Aug. (2001) .
Y. Takahashi, Y. Minai, and S. Enomoto: "Application of multitracer technique for environmental andgeochemical studies" , IUPAC Int. Congr. on Analytical Sciences 2001 , (Japan Society for Analytical
Chemistry), Tokyo, Aug. (2001).
R. Hirunuma and S. Enomoto: "Application of themultitracer technique: Metabolic study of various elements in Se-deficient an Se-excessive rats", IUPAC
Int. Congr. on Analytical Sciences 2001, (Japan Society for Analytical Chemistry), Tokyo, Aug. (2001).
K. Matsumoto, R. Hirunuma, S. Enomoto, and K.
Endo: "In vivo detection of dynamics elements in aliving rat using multitracer technique", IUPAC Int.
Congr. on Analytical Sciences 2001, (Japan Society
for Analytical Chemistry), Tokyo, Aug. (2001).
S. Enomoto: "The multitracer technique: Manufacturing and application to bio-trace elemental research" ,IUPAC Int. Congr. on Analytical Sciences 2001,(J apan Society for Analytical Chemistry) , Tokyo,
Aug. (2001).
T. Ohyama, M. Kidera, T. Nakagawa, K. Takahashi,
K. Igarashi, R. Hirunuma, and S. Enomoto: "Accelerator mass spectrometry using electron cyclotron
resonance ion source (Application study for analysis of trace elements)", 12th Cholk Talk (Meet.
for Organism and Trace Elements), (University of
Shizuoka), Shizuoka, Aug. (2001).
T. Abe, T. Matsuyama, and S. Yoshida: "Genome
Analysis of plant mutants induced by ion-beam irradiation using RLGS profiles", 8th Seminar of Accelerator and Related Technology for Application,
Tokyo, Sept. (2001).
Y. Kobayashi , K. Kubo, Y. Yamada, T. Saito, A.
Yoshida, H. Ogawa, H. Ueno, and K. Asahi: "Inbeam Mossbauer study of 57Fe species arising from
57Mn implanted into KMn04", Int. Conf. on the
Apllications of the Mossbauer Effect (ICAME2001) ,Oxford, UK, Sept. (2001).
F. Yatagai, S. Goto, S. Morimoto, and T. Kato: "Estimation for biological effects of heavy-ion exposurein space", 15th Ann. Meet. of Japanese Soc. for Biological Sciences in Space, Tokyo, Sept. (2001).
T. Takanami, H. Takahashi, T. Abe, S. Yoshida, and
A. Higashitani: "Repair systems for DNA damage
by heavy-ion irradiation in meiotic cells", 15th Ann.
Meet. of Japanese Soc. for Biological Sciences inSpace, Tokyo, Sept. (2001).
H. Nagase, F. Ike, N. Hiraiwa, and A. Yoshiki: "Anattempt to screen cancer susceptibility loci by introducing germline mutation using heavy ion beams",
60th Ann. Meet . of the Japanese Cancer Association,
Yokohama, Sept. (2001).
H. Tsujimoto, M. Kishii, T. Yamada, and T. Abe:"Molecular cytogenetic analysis of chromosome
breakage in wheat induced by heavy ion-beam irradiation", 73rd Ann. Meet. of the Genetics Soc. of347

Japan, Tokyo, Sept. (2001).
T. Matsuyama: "RLGS analysis in plant mutants induced by physical mutagens and virtual RLGS profiling", 100th Congr. of the Breeding Soc. of Japan,
Fukuoka, Oct.- Nov. (2001).
K. Matsumoto, H. Nagashima, R. Hirunuma, S.
Enomoto, and K. Endo: "Affinity of various biotrace elements to lipid membrane: In vitro study
using multitracer", 2001 Asia-Pacific Symp. on Radiochemistry and Ann. Meet. of the Japan Soc. of
Nuclear and Radiochemical Sciences (APSORC 2001
and 45th SORC), Fukuoka, Oct.- Nov. (2001).
T. Saito, Y. Kobayashi, K. Kubo, and Y. Yamada:"Development and application of Parallel-Plate
Avalanche Counter for in-beam Mossbauer spectroscopy", 2001 Asia-Pacific Symp. on Radiochemistry and Ann. Meet. of the Japan Soc. of Nuclear
and Radiochemical Sciences (APSORC 2001 and45th SORC) , Fukuoka, Oct.- Nov. (2001).
Y. Kobayashi, K. Kubo, Y. Sakai, Y. Yamada, T.
Saito, H. Shoji, C. Yonezawa, and H. Matsue: "Inbeam Mossbauer spectroscopic studies of chemical effects associated with the 56Fe(n,1' ) 57 Fe reaction", 2001 Asia-Pacific Symp. on Radiochemistry
and Ann. Meet. of the Japan Soc. of Nuclear andRadiochemical Sciences (APSORC 2001 and 45th
SORC), Fukuoka, Oct.- Nov. (2001).
Y. Yabushita, Y. Kanayama, T. Tarohda, R. Amano,
and S. Enomoto: "Multitracer and neutron activation screening: Brain regional concentration andtracer uptake behavior in mice bred under controlled
diets", 2001 Asia-Pacific Symp. on Radiochemistry
and Ann. Meet. of the Japan Soc. of Nuclear andRadiochemical Sciences (APSORC 2001 and 45th
SORC), Fukuoka, Oct.- Nov. (2001).
T. Ohyama, M. Yanaga, H. Maetsu, M. Noguchi , H.
Suganuma, K. Ishikawa, M. Kidera, T. Nakagawa,R. Hirunuma, S. Enomoto, and T. Omori: "Theabnormal metabolism of trace elements in mouse
induced by Zn deficiency during the growing period", 2001 Asia-Pacific Symp. on Radiochemistry
and Ann. Meet. of the Japan Soc. of Nuclear andRadiochemical Sciences (APSORC 2001 and 45th
SORC), Fukuoka, Oct.- Nov. (2001).
Y. Kobayashi , K. Kubo, T . Saito, H. Ueno, H. Miyoshi ,K. Yoneda, W. Sato, and Y. Yamada: "Valence
states of 57Fe decayed from 57Mn implanted into
KMn04" , 2001 Asia-Pacific Symp. on Radiochemistry and Ann. Meet. of the Japan Soc. of Nuclear
and Radiochemical Sciences (APSORC 2001 and45th SORC) , Fukuoka, Oct.- Nov. (2001).
K. Matsumoto , 1. Ui, R. Hirunuma, S. Enomoto, and
K. Endo: "In vivo assessment of dynamics of various
elements living rat using multitracer", 2001 AsiaPacific Symp. on Radiochemistry and Ann. Meet. of
the Japan Soc. of Nuclear and Radiochemical Sciences (APSORC 2001 and 45th SORC), Fukuoka,

348

Oct.- Nov. (2001).
S. Morimoto, T. Kato, M. Honma, S. Goto, M. Izumi ,F . Hanaoka, and F. Yatagai: "Analysis of tk mutation induced by low dose ionizing radiation in humancells", 44th Ann. Meet. of the J apan Radiation Research Society, Osaka, Oct. (2001).
F. Yatagai, S. Goto, S. Morimoto, T. Kato, F.
Hanaoka, and Y. Yano: "Cellular responses after
heavy-ion exposure", 44th Ann. Meet. of the Japan
Radiation Research Society, Osaka, Oct. (2001).
M. Hoshino, K. Masumura, F. Yatagai, M. Ochiai, O .
Ueda, H. Suzuki, H. Nakagama, M. Fukuoka, and T.
Nomi: "X-ray-induced mutations in the brain andthe spleen of gpt delta transgenic mouse", 8th Int .
Conf. on Environmental Mutagens , Shizuoka, Oct.
(2001) .
Y. Kobayashi: "Valence states of 57Fe atoms arisingfrom 57Mn implanted into KMN0 4", Specialist Research Meet. on Positron Beam Techniques and Condensed Matter, (Research Reactor Institute, Kyoto
University), Kumatori, Oct. (2001).
T. Abe: "A new method for muation induction by
heavy-ion irradiation on plants", 100th Meet. of theJapanese Society of Breeding, Fukuoka, Oct. (2001).
Y. Konomi , T. Abe, K. Sekino, H. Koyanagi, Y.
Yamada, F. Sugawara, and S. Yoshida: "Benzobicyclon resistant tobacco using heavy ion-beam mutagenesis", 36th Ann. Meet. of the Japanese Society
for the Chemical Regulation of Plants, Toyama, Oct.
(2001).
T . Matsuyama, K. Koike, T. Ebisuzaki, T. Abe, andS. Yoshida: "A DNA polymorphism detection system by computer simulation using the Arabidopsis
genome sequences-a virtual imaging restriction landmark genomic scanning", 10th DNA Polymorhism,
Okayama, Nov . (2001).
S. Morimoto, S. Goto, T. Kato, M. Honma, F.
Hanaoka, and F. Yatagai : "Genetic Alteration inhuman cell after low-dose IR exposure", 18th Radiation Biology Center Int. Symp. on Bioregulationof Radiation Response: Damage Recognition, Processing and Cellular Response , (Radiation Biology
Center, Kyoto University) , Kyoto, Nov . (2001) .
T. Abe, T. Matsuyama, and S. Yoshida: "Induction of
mutation in plants using ion-beam irradiation" , 9thRadiation Process Symp. , Tokyo , Dec. (2001).
5.

Material analysis

K. Maeda, K. Hasegawa, and H. Hamanaka: "Chemical specification by high-resolution PIXE" , 1st
Sino-Japanese Seminor on Application of Acceleration Radiation , (National Science Council Taiwan),
Hsinchu , Taiwan, Dec. (2000).
K. Maeda, K. Hasegawa, H. Hamanaka, M. Maeda,
S. Yabuki, and K. Ogiwara: "Rapid chemical state
analysis by a highly sensitive high-resolution PIXE

system", 15th Int. Conf. on Ion Beam Analysis, (The
Australian National University), Cairns, Australia,
July (2001).
J. Kawai, Y. Fukuda, J. Kawamura, and K. Maeda:"PK,8 X-ray fluorescence spectrum of B 13 P 2", 50th
Ann. Meet. of the Japan Soc. for Analytical Chemistry, Kumamoto, Nov. (2001).
H. Hamanaka, K. Maeda, K. Hasegawa, and S.
Yumoto: "Chemical state analysis of Al compounds
using a crystal spectrometer in PIXE measurements(sample positioning using a laser displacement sensor)" , 18th PIXE Symp., (The Japan Society for
Particle Induced X-ray Emission (PIXE) Research),
Chiba, Nov. (2001).
K. Maeda, K. Hasegawa, H. Hamanaka, and M.
Maeda: "Improvement in the sensitivity of in-air
high-resolution PIXE" , 18th PIXE Symp., (TheJapan Society for Particle Induced X-ray Emission(PIXE) Research) , Chiba, Nov. (2001).
H. Hamanaka, K. Hasegawa, and K. Maeda: "Sample
positioning using a laser displacement sensor in highresolution PIXE with a position sensitive crystal
spectrometer", 20th Symp. on Materials Science andEngineering, (Research Center of Ion Beam Technology, Hosei University), Koganei , Dec. (2001).
6.

RIKEN-BNL Collaboration on Spin Physics Program

W. Vogelsang: "Current issues in prompt photon product ion" , 8th Int. Workshop on Deep-Inelastic Scattering (DIS 2000), Liverpool, UK , Apr. (2000).
W. Vogelsang: "Prompt photon production in polarized hadron collisions", 8th Int. Workshop on DeepInelastic Scattering (DIS 2000), Liverpool, UK, Apr.
(2000).
W. Vogelsang: "Spin asymmetries in polarized hadroncollisions and the polarized gluon density" , 7th Conf.
on Intersections of Particle and Nuclear Physics(CIPANP2000), Quebec, Canada, May (2000).
E. Laenen, G. Sterman, and W. Vogelsang: "Combined recoil and threshold resummation for hard
scattering cross sections", 30th Int. Conf. on HighEnergy Physics (ICHEP 2000) , Osaka, July- Aug.
(2000) .
E. Laenen , G. Sterman, and W. Vogelsang: "Powercorrections in eikonal cross sections" ,30th Int. Conf.
on High Energy Physics (ICHEP 2000) , Osaka,July- Aug. (2000).
D. Son: "Hydrodynamics of relativistic systems withbroken continuous symmetries", Meet. of the Division of Particle and Fields of the Am. Phys. Soc.
(DPF2000), (APS), Columbus, USA, Aug. (2000).
J. Murata, N. Saito, T. Shibata, and M. Sugioka:"Construction of the PHENIX south arm muontracking chamber" ,55th Ann. Meet. of Physical Soc.
of Japan, Niigata, Sept. (2000).

S. Yokkaichi, T. Ichihara, H. En 'yo, Y. Goto, S.
Sawada, A. Taketani, N. Hayashi, H. Hamagaki,
and Y. Watanabe: "PHENIX computing center inJapan (CC-J): Open and operating status", 55th
Ann. Meet. of Physical Soc. of Japan, Niigata, Sept.
(2000).
W. Vogelsang: "Nucleon spin structure functions",
14th Int. Spin Physics Symp. (SPIN 2000) , (RCNP,
Osaka University), Suita, Oct. (2000).
D. Son: "Electroweak matter", 2000 Fall Meet. of theDivision of Nuclear Physics, (ADS) , Williamsburg,
USA, Oct. (2000).
H. Kobayashi: "Polarized parton distributions with estimate of uncertainties" , Int. Workshop on Polarized
Partons at High Q2 Region, Kyoto , Oct. (2000).
J. Murata: "Beyond standard model at RHIC", Int.
Workshop on Polarized Partons at High Q2 Region,(Yukawa Institute for Theoretical Physics , Kyoto
University), Kyoto, Oct. (2000).
W. Vogelsang: "Soft-gluon effects in prompt-photon
production" , RSC Meet. , Kyoto , Oct. (2000) .
K. Itakura: "Gluon saturation from non-linear evolution equation at small x" , Kenkyukai "Ba no Ryoshiron no Kisoteki Shomondai to Oyo" , (Yukawa Institute for Theoretical Physics , Kyoto University),
Kyoto, Dec. (2000).
Y. Watanabe: "Regional computing center in Japanfor RHICjPHENIX Experiment", ICEPP Seminar
2001 , (International Elementary Particle Physics,
University of Tokyo) , Tokyo, Jan. (2001).
N. Ishii, H. Suganuma, and H. Matsufuru: "Glueballproperties in anisotropic SU(3) lattice QCD with an
improved action", Workshop on Lepton Scattering,
Hadrons and QCD , (The Special Research Centerfor the Subatomic Structure of Matter and the National Institute for Theoretical Physics) , Adelaide,
Australia, Mar.- Apr. (2001).
M. Hirai: "Determination of polarized parton distirbution at RHIC", RCNP Workshop on Hadron Structure and Reaction by Non-Perturbative QCD Approach, (RCNP and ISIR, Osaka University), Osaka,
July (2001).
N. Ishii , H. Suganuma, and H. Matsufuru: "Glueball properties at finite temperature" , RCNP Workshop on Hadron Structure and Reaction by NonPerturbative QCD Approach, (RCNP and ISIR,
Osaka University), Osaka, July (2001).
N. Ishii, H. Suganuma, and H. Matsufuru: "Glueballproperties at finite temperature", LATTICE2001:
19th Int. Symp. on Lattice Field Theory, (DESY
Zeuthen) , Berlin, Germany, Aug. (2001).
S. Yokkaichi , T. Ichihara, Y. Watanabe, N. Hayashi, S.
Sawada, Y. Goto, O. Jinnouchi, H. Hamagaki , and
H. En 'yo: "The RIKEN CCJ (computing center inJapan) for RHIC physics", Int. Conf. on Computing
in High Energy and Nuclear Physics (CHEP 2001) ,Beijing, China, Sept. (2001).

349

H. Kobayashi: "Alignment and calibration of the
PHENIX muon tracker", 1st Joint Meet. of the Nuclear Physics Divisions of APS and JPS Hawaii 2001
(HAW01), (American Physical Society) , Maui, USA,
Oct. (2001).
N. Ishii, H. Suganuma, and H. Matsufuru: "Glueballproperties at finite temperature" , 1st Joint Meet .

350of the Nuclear Physics Divisions of APS and JPS
Hawaii 2001 (HAW01), Maui, USA, Oct. (2001).
M. Hirai: "Uncertainty of polarized parton distributions", 3rd Circum-Pan-Pacific Symp. on HighEnergy Spin Physics, (Peking University), Beijing,
China, Oct. (2001).

x. LIST OF SYMPOSIA(Jan.- Dec. 2001)
1) 11th RIKEN Winter School on In-beam Gamma-ray Spectroscopy with RI Beams
8- 13 Jan., Niigata, RI Beam Science Lab., RIKEN
2) RIKEN Workshop on Approaches to the Structure of Unstable Nuclei in the Mean Field Models
17- 19 Jan., Wako, RI Beam Science Lab., RIKEN
3) RIKEN Symp. on Physics at Drip Lines
13- 16 Feb. , Wako, RI Beam Science Lab., RIKEN
4) RBRC Workshop on RHIC Spin Physics V
21 Feb., New York, USA, RBRC, RIKEN
5) Int. Workshop on Radiation Damage 2001: Repair, Mutagenesis , and Visualization
14- 16 Mar., Tokyo, Radioisotope Technology Div. , Cellular Physiology Lab., RIKEN and Promotion Committee on Nuclear Cross-Over Research
6) RIKEN Workshop on Towards Physics of Unstable Nuclei
24- 26 Mar., Wako, RI Beam Science Lab., RIKEN
7) Muon Catalyzed Fusion and Related Exotic Atoms
22-26 Apr. , Shimoda, Muon Science Lab., RIKEN
8) RIKEN Workshop on Alpha-particle Condensation and Two-neutron Condensation in the Neutron-rich
Nuclei (N » Z)
1- 3 May, Wako , RI Beam Science Lab. , RIKEN
9) RBRC Workshop on Spin Physics at RHIC in Year-1 and Beyond
14- 18 May, New York, USA, RBRC, RIKEN
10) RBRC Workshop on High Energy QCD: Beyond the Pomeron21- 25 May, New York, USA, RBRC, RIKEN
11) RIKEN Workshop on Cluster Physics and Unstable Nuclei
30 Aug.-1 Sept., Wako, RI Beam Science Lab., RIKEN
12) 4th Italy-Japan Symp. on Heavy Ion Physics
26- 29 Sept. , Wako, Tokyo, RI Beam Science Lab. , RIKEN
13) t-tSR Studies at RIKEN-RAL
1 Oct. , Wako, Muon Science Lab., RIKEN
14) RBRC Workshop on RHIC Spin Physics VI
1 Oct., New York, USA, RBRC, RIKEN
15) RIBF Nuclear Astrophysics Workshop (I) on Pigmy Resonances and the r-Process
6 Oct. , Wako, RI Beam Science Lab., RIKEN
16) Workshop on Cyclotron Mutagenesis
8 Oct., Fukuoka, Plant Functions Lab., RIKEN and Japanese Society of Breeding17) RBRC Workshop on RHIC Spin Physics VI Part-2
15 Nov ., New York, USA, RBRC, RIKEN

351

18) Physics with Primay Beams of 400 MeV lu at RIBF
28- 29 Nov. , Wako , RI Beam Science Lab., RIKEN
19) RIBF Nuclear Astrophysics Workshop (II) on Stellar Electron Capture and Supernovae
10- 11 Dec. , Wako, RI Beam Science Lab. , RIKEN
20) Int. Workshop on Developments of Ge Detector Array and Frontiers of Gamma-ray Spectroscopy
11- 13 Dec. , Wako and Tokyo, RI Beam Science Lab., RIKEN , CNS, and Rikkyo University21) Development and Application of the Multitracer Technique
21 Dec. , Wako, Cyclotron Center, RIKEN

352

XI. LIST OF SEMINARS(Jan.-Dec. 2001)
Radiation Lab., RI Beam Science Lab., Applied Nuclear Physics Lab., and Beam Technology Div.

1) T .-L. Khoo, Argonne National Laboratory(USA), 15 Jan.
"At the limits of nuclear charge, spin and energy
with heavy shell-stablilized nuclei"
2) G. Bunce, BNLjRBRC (USA), 14 Feb.
"Precise measurement of the positive muon
anomalous magnetic moment""Quadrupole collective states in the Monte-Carloshell model"
13) K . Arai, Universite Libre de Bruxelles (Belgium) ,3 Sept .
"Low-energy 6He+p reaction in a microscopic
multicluster model"
14) C . Shen, China Institute of Atomic Energy(China), 17 Sept.
"Dynamical calculation of residue cross section
for superheavy elements"

3) K. Hikasa, Tohoku University (Sendai), 14 Feb.
"Old and new physics vs (g-2)p,"15) O. Klepper, GSI Darmstadt (Germany), 21 Sept.
"Measurements of nuclear masses and half-lives
in the cooler-storage ring ESR"

4) G. D. Dang, Laboratoire de Physique Theorique
Universite de Paris-Sud (France), 9 Mar.
"Dissipation of a slow motion by a complex system: A random matrix approach"16) A. Bulgac, University of Washington (USA), 24
Oct .
"Local density approximation for systems withpairing correlations"

5) V. Zagrebaev, JINR (Russia), 13 Mar.
"Exploration of multi-neutron halos in 6,8He induced low-energy transfer reactions"17) J . Gal, ATOMKI (Hungary), 6 Nov.
"The electronics of the EUROBALL's CsI particle
detector array. (Processing of CsI detector signals
for determination of the type and the energy ofthe particles)"6) P. Schuck, Universite Joseph Fourier (France), 26
Apr.
"Proton-neutron pairing in low density symmetricand asymmetric nuclear matter"7) G. Roepke , UniversUit Rostock (Germany), 26
Apr.
"Correlations in dense matter"8) G. Duchene, Institut de Recherches Subactomiques (France), 4 June"First results with EUROBALL IV and hints inthe future of 'Y-spectroscopy"9) K. Iida, RIKEN (Wako), 26 June
"Superfiuid phases of quark matter: GinzburgLandau theory and color neutrality"10) K. Varga, Oak Ridge National Laboratory (USA),
16 July"From nuclei to quantum dots: Large scale variational calculations"11) G. Kosenko, Omsk State University (Russia), 27
Aug.
"Stochastic-statistical approach for fusion-fission
reactions"18) G. Kalinka, ATOMKI (Hungary), 6 Nov.
"Construction of high quality CsI(TI) scintillation
detectors for charged particle spectroscopy"19) G. Lalazissis, Aristotle University of Thessaloniki(Greece), 12 Nov.
"Relativistic Hartree-Bogoliubov (RHB) description"20) A. Volya, Michigan State University (USA), 13
Nov.
"Towards better understanging of nuclear pairingand its interplay with other residual interactions"21) U. D. Pramanik, GSI (Germany), 16 Nov.
"The study of properties of unstable nuclei at
GSI"22) V. Y . Denisov, GSI (Germany), 16 Nov.
"Formation of superheavy elements in fusion reactions: Interaction potential well between very
heavy ions"23) Z. Ren , Nanjing University (China), 19 Nov.
"Neutron halo and proton halo in light exotic nuclei"12) N. Shimizu, RIKEN (Wako), 28 Aug.

353

24) N. Sandulescu, Institute for Physics and Nuclear
Engineering (Romania) , 26 Nov.
"Pairing correlations and continuum effects in
drip line nuclei"25) S. M. Lukyanov, JINR (Russia) , 29 Nov.
"Fusion enhancement above the barrier for the
6He + 209Bi-reaction""Brownian motion and anchor effect"2) R. H. Herber , The Hebrew University ofJerusalem (Israel), 26 Oct.
"Metal atom dynamics and vibrational anisotropy
in iron organometallics"
Atomic Physics Lab.

26) Yu. E. Penionzhkevich, JINR (Russia), 29 Nov.
"Radioactive ion beams in Dubna: The DRIBs
project"

1) R. Neumann, GSI (Germany) , 27 Feb.
"Survey of materials research at GSI"RI Beam Science Lab.

2) J. Horacek, Charles University (Czech Republic) ,9 Mar.
"Recent progress in dissociative attachment"

1) T. Suzuki, Fukui University (Fukui)/RIKEN(Wako), 24 May"N uclear surface"2) B. Sherrill, Michigan State University (USA) , 14
June
"Coupled cyclotron facility at MSU"
3) Y. Oganesseian, JINR (Russia) , 14 June
"The properties of superheavy nuclei with Z =114-116 and their synthesis in fusion reactions
with 48Ca ions"4) K. Oyamatsu, Aichi Shukutoku University (Nagakute) , 23 July
"The equation of state of asymmetric nuclear
matter"5) Y. En 'yo, KEK (Tsukuba), 18 Sept.
"Neutron and proton densities in light unstable
nuclei studied with AMD"6) M. Smith, Oak Ridge National Laboratory(USA) , 4 Oct.
"Radioactive beam experiments & theoreticalmodels of stellar explosions"7) A. Schaefer, Regensburg University (Germany),
30 Oct.
"Topological modes in lattice QCD"
8) W. von Oertzen, Freie Universita Berlin/HahnMeitner-Institut (Germany) , 31 Oct.
"Covalently bound molecular structures in lightnuclei"

3) D. Gotta, University Juelich (Germany) , 20 Apr.
"Strong-interaction effects in light antiprotonic
atoms"
4) H. Tsuchida, Nara Women 's University (Nara) ,26 Apr.
"Elastic deformation of metal foils by ion beamirradiation"5) P. Nordlander, Rice University (USA) , 18 May"Interaction of Rydberg atoms with metal surfaces"
6) V. Varentsov , V. G. Khlopin Radium Institute(Russia), 8 June
"A new approach to the extraction system design
and a cooler for intense low-energy ion beams"
7) H. O. Lutz , Bielefeld University (Germany) , 15
June"How molecules and clusters explode"8) T. Nishimura, University Rome (Italy) , 10 Aug.
"Low-energy positron dynamics in polyatomic
gases"
9) H. Suno, Kansas State University (USA), 10 Aug.
"Rydberg atoms in parallel electromagnetic field"
10) B. DePaola, Kansas State University (USA), 16
Aug.
"Low-energy alkali collisions with ground and excited state Rb, investigated using MOTRIMS"

Applied Nuclear Physics Lab.

11) K. D. A. Wendt , Johannes Gutenberg-Universitat(Germany), 16 Aug.
"Ultra trace isotope determination in environmental , bio-medical and fundamental research byhigh resolution laser-mass spectrometry"

1) Y. Hsia, Nanjing University (China) , 26 Oct .

12) A. Casares, Oak Ridge National Laboratory

9) K . Langanke, Aarhus University (Denmark), 11
Dec.
"Supernova and nuclear physics"354

(USA), 26 Oct.
"Multi reflection time of flight mass spectrometer"

6) R. Nagaoka, ESRF (France), 3 Sept.
"Overview of transverse beam instability studies
made at the ESRF"

13) W. Heiland, Osnabriick University (Germany) , 19
Nov.
"Electronic surface corrugation evaluated fromsurface channeling experiments"

7) D. Bazin, Michigan State University (USA), 11
Sept.
"The S800 spectrograph at NSCL: Presentationand some results"14) R. Hutton, Lund University (Sweden), 26 Nov.
"Atomic physics in the home"8) M. D. Giacomo, GANIL (France), 12 Sept.
"Introduction to the GANIL RF systems"

15) H. A. Schuessler, Texas A&M University (USA) ,4 Dec.
"Endohedral secrets"

9) R. Nagaoka, ESRF (France), 17 Sept.
"Work carried out at the ESRF to characterizeand correct the coupling"16) F. B. Rosmej, GSI (Germany), 11 Dec.
"Direct observation of space resolved charge state
distribution of fast ions inside matter"10) 1. N. Meshkov, JINR (Russia), 5 Oct.
"Recent progress of electron cooling at Julich"

Cellular Physiology Lab.

1) H. Matsumoto, Fukui Medical Univ. (Fukui), 16
Feb.
"Bystander effects by NO radical"
2) E. Drobetsky, Maisonneuve-Rosemont Hospital(Canada) , 12 Mar.
"The role of the p53/p21/pRb pathway in nucleotide excision repair"3) E. Sage, Institut Curie (France) , 19 Oct.
"Roles of RAD30 and REV3 genes in solar UVmutagenesis in Saccharomyces cerevisiae"
RIBF Project Office, Beam Physics and EngineeringLab., Beam Dynamics Div., and Beam Technology
Div.

1) G. Shirkov, JINR (Russia) , 9 May"Laser ion loading into ECR source"2) Y. Mori and S. Machida, KEK (Tsukuba), 8 June
"FFAG Accelerator (I): Aiming at acceleration of
the short-lived particles"3) N. Ohuchi, KEK (Tsukuba) , 22 June
"Magnetic field measurement system for super
conducting magnets at KEK"
4) M. Yoshii , KEK (Tsukuba) , 16 July"Longitudinal barrier bucket"
5) K. Sato, RCNP, Osaka University (Suita) , 17 July"Longitudinal-transverse coupling motion withsecond-order term of energy deviation in circular
accelerators"

11) B. Sharkov, ITEP (Russia) , 5 Oct.
"Status of laser ion source for LHC-CERN"
12) M. Shiho, JAERI (Tokai), 19 Nov.
"Studies of induction linacs at the JAERI"
Computational Science Div.

1) K. Isao , Universite de Sherbrooke (Canada) , 19
Apr.
"Electron wave packet dynamics with a dualtransformation technique"2) H. Shinkai, RIKEN (Wako) , 10 May"Introduction to numerical relativity"
3) T. Yamamoto, RIKEN (Wako) , 14 June"First principles calculations of minerals"4) T. Iitaka, RIKEN (Wako) , 30 Aug.
"First principles calculation of elastic properties
of solid argon at high pressures"
5) T. Morishita, RIKEN (Wako), 11 Oct.
"Liquid-liquid phase transitions of phosphorus
via constant-pressure first-principles molecular
dynamics simulations"
RIKEN BNL Research Center

1) M. Burkhardt, New Mexico State University(USA) , 9 Jan.
"Physics of off-forward parton distributions"2) A. Ogawa, Pennsylvania State University (USA),
6 Feb.
"Azimuthal asymmetries in hadron production at
e+e- colliders and chiral-odd fragmentation functions"355

ization prediction at RHIC"

3) R. Bellwied, Wayne State University (USA), 27
Feb.
"Transverse polarization of the Lambda measured
in Au-Au collisions"15) S. Sasaki, University of Tokyo (Tokyo), 15 Aug.
"Spin on lattice"4) S. Gupta, Tata Institute for Fundamental Physics(India), 13 Mar.
"Longitudinally polarised parton densities"16) P. Haegler, Universitat Regensburg (Germany),
14 Sept .
"Parton orbital angular momentum"5) Y. Koike , Niigata Univ. , 27 Mar.
"Single spin asymmetries at RHIC"

17) A. Freund, U niversitat Regensburg ( Germany) ,18 Sept.
"DVCS in next-to-leading order"

6) P. Nadolsky, Michigan State University (USA) , 3
Apr.
"Resummation in polarized W-Boson production:
Lepton-level results"18) J. Tojo, Kyoto University (Kyoto), 21 Sept.
"E950 data"

7) K. Orginos , RBRC (USA) , 17 Apr.
"Nucleon matrix elements with lattice QCD"

19) B. Kopeliovich, L. Trueman, Max-Planck-Institute (Germany)/BNL (USA), 21 Sept.
"Polarimetry at RHIC: Present status and perspectives"

8) V. Rykov , Wayne State University (USA) , 21 May"CP-violating higgs at RHIC spin and at the future linear e+e- collider"

20) H. Huang, BNL (USA), 16 Oct.
"Tutorial of polarized proton acceleration"

9) J.-C. Peng, Los Alamos National Laboratory(USA) , 12 June"pA physics opportunities at PHENIX 7"21) G. Xu, BNL (USA), 23 Oct.
"A possible test to T-violation and its mechanisms"

10) A. Deshpande, RBRC (USA), 19 June
"The physics and status of EIC (I)"22) D. Boer, Vrije University (The Netherlands) , 30
Oct.
"Transversely polarized Lambda production"11) J. Murata, RIKEN (Wako)/RBRC (USA), 3 July
"Simulation formalism for parity violation via SM
and contact interaction"12) Y. Shestakov, BINP (Russia), 10 July"High density polarized deuterium gas targets"
13) J. Qiu, Iowa State University (USA), 14 Aug.
"Single transverse spin asymmetries in drell-yan
lepton's angular distribution"14) E. Predazzi, INFN (Italy), 15 Aug.
"Diffractive contribution to spin flip and polar-

35623) W. Mackay, BNL (USA), 6 Nov.
"Preparation for first polarizated proton collisions: Update on accelerator preparation"24) K. Kurita, RBRC (USA), 6 Nov.
"Preparation for first polarizated proton collisions: Update on polarimetry"25) Y. Goto, RBRC (USA), 6 Nov.
"Preparation for first polarizated proton collisions: Spin monitoring"XII. LIST OF PERSONNELRARF /RIBF Project Head Office

INOUE Yorinao it L:illl (Director)
ISHIHARA Masayasu 15)Jj( lE(Project Advisor)*

Cyclotron GroupYAN 0 Yasushige-!k. 'f 17:: ~ * 1

Beam Dynamics TeamFU JIMAKI Masaki Iii ~ lE 1M
GOTO Akira f~ Iii~ *2
INABE Naohito fffi ill riD A
KAGEYAMA Tadashi ~ LlJ
lE
NAGASE Makoto :& ~Ji
Wit
OHTAKE Masao -}:;. it 1& it
SAKAMOTO Naruhiko :t&~ "&WAKASUGI Masanori 11f 1~ ~ f!

*

FUKUNISHI Nobuhisa t~"@ ~ riD
IKEGAMI Kumio 7t!!L1L =~ITO Sachiko iJt Ii tf r
KAMIGAITO Osamu L±l!ji-11~ ­o HNISHI J un-ichi -}:;."@ *4. OKUNO Hiroki ~!f r.t 1M
TANABE Toshiya EI3 ill ~ ti1

Beam Technology TeamFU JIMAKI Masaki Ii ~ lE 1M (~)
FU JITA Shin Ii EI3#JrINABE Naohito fffi ill riD A (~)
KAGEYAMA Tadashi ~ LlJ
lE (j.:)KOHARA Shigeo IJ'\)Jj( ~ :;tNAGASE Makoto :& ?~]iWit (~)
OGIWARA Kiyoshi ~)Jj(
jw==

FUJITA Jiro Ii EI3e~
IKEZAWA Eiji it!! rR ~ITO Sachiko 1Jt Iii tf r (~)
KASE Masayuki
7iji ~ Z *2
MORITA Kosuke ~ fE 115- 11'NAKAGAWA Takahide I=j:l}ll ~TANABE Toshiya EI3 ill ~ ti1 (~)

no*Experimental Rings Group

KATAYAMA Takeshi

h LlJ lit ~ *1

Accumulator Cooler Ring Team

INABE Naohito fffi ill riD A (~)
NAKAMURA Masato I=j:l ift 1= 1f
TANABE Toshiya EI3 ill ~ ti1 (~)
WATANABE Tamaki rOC jI~

KATAYAMA Takeshi h LlJ lit P] (~) *2
OKAMURA Masahiro IRiJ ift ~WAKASUGI Masanori 11f 1~ ~ f! (~)*

Collider Ring Team

INABE Naohito fffi ill riD A (~)
OKAMURA Masahiro [RiJ ift ~(~)
WATANABE Tamaki rOC jI
~ (~)

*

KATAYAMA Takeshi h LlJ lit ~ (~) *2
WAKASUGI Masanori 11f 1~ ~ f! ( ~)Experimental System GroupTANIHATA Isao

~ 1m ~ :;t *1

Nuclear Reaction Team*KORSHENINNIKOV Alexei A.
MORIMOTO Kouji ~¥ ~OZAWA Akira IJ'\ rR~l
TANIHATA Isao ~ 1m ~ :;t (~) *2
YOSHIDA Koichi ~ EI3 Jt -KUBO Toshiyuki ~ 1~ ~ ¥NISHIMURA Shunji "@ ift 13f:
SUDA Toshimi ~J{ fE flJ ~WATANABE Yasushi rOC:il
YOSHIDA Atsushi -ff EI3
~51:

=
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357

Low Energy TeamASAHI Koichiro M *11=- ~~ *2
KOBAYASHI Yoshio IJ'\;ft ~ ~UEN 0 Hideki L lff ~ ;fit

KISHIDA Takashi
SHIMIZU Hirohiko* 7.K tfr &Atomic and Other Science TeamABE Tomoko ~OJ:g~ 920 -=f
IKEDA Tokihiro ?lli 83 ~ ¥~KANAI Yasuyuki sj£:#- 1:* Z
KOJIMA Takao IJ'\ ~ ~f ~NAKAI Yoichi 9J:#- ~~ WADA Michiharu
83 jg i5*0*'*

ENOMOTO Shuichi flf;; KAMBARA Tadashi 1$
iE
KOBAYASHI Yoshio IJ'\
~ ~ (~)
MATSUO Yukari fJ}~EB~5f1J
OYAMA Hitoshi
LlJ~
YAMAZAKI Yasunori LlJ 1iI~ ~*2*

Experiment Support Teamm'*

I CHIHARA Takashi!j[
KANAI Yasuyuki sj£:#- f:lf!:(~)
MORITA Kosuke ~ 83 ¥~ fr (~)
YATAGAI Fumio :fi.83~Jt~

z

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83

1~

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KAMBARA Tadashi 1$
iE (~) *2
MATSUZAKI Teiichiro fJ}liPp}t~m ~~WATANABE Yasushi iJi jJ(~)"*

Planning and Coordination GroupMAN ABE Tadashi~ f~?!{ *1

Planning and Coordination OfficerI *EMOTO Takashi~i
NAKAMURA Toshiko 9J ift C: l-=f
OKAZOE Hiromu [tli] i~~L. *3TASHIRO Satoshi 83 it~;g
UWAMIN 0 Yoshitomo L Jt ~ ~JJ

KOGURE Mieko IJ'\~ ~~-=f
NUMATA Shigeo
83~
SATO Kenji 1tc ii :PJf 15
TOKUOKA Haruhiro 1~ [tli] 15 i$m a:Steering Committee

ASAHI Koichiro jl.§. *it- ~~EN'YO Hideto W;S W f;; A
KAMBARA Tadashi 1$
iE
KATAYAMA Takeshi h LlJ m: 15]
NAG AMINE Kanetada 7]( ~ ~ ,~,TANIHATA Isao :fi. 1ffi ~ j(
YAN 0 Yasushige
lff 11:YOSHIDA Shigeo E 83~'*

* a: .m*1 Group Director,

358*2 Team Leader,*3 HeadGOTO Akira 1& ii~
I CHIHARA Takashi
JJjf,
!j[
KASE Masayuki 110 11 ~ z
MATSUZAKI Teiichiro tJ}liPp}t~m~~
SAWA Hiroshi ~~71;
YAMAZAKI Yasunori LlJ i1J~ ~ *J!
YATAGAI Fumio :fi.EE~Jtj(m

111111111111111111111111111111111111111111111111

Members (included Special Postdoctoral Researcher,
RIKEN Fellow, and Contract Researcher)
111111111111111111111111111111111111111111111111

Cosmic Radiation Laboratory
Members
KATO Hiroshi 110 iii
ffl
YOSHIDA Atsumasa E 133 ~ lE

MIYASAKA Hiromasa

g

* lE
i~

* *=

Visiting Members
GOKA Tateo 1i§t(NASDA)KOSHIISHI Hideki ~ n "!J[; ttt (NASDA)
MATSUMOTO Haruhisa :t~ /.$: 8ff IJ\. (NASDA)

Radiation Laboratory
Head

EN'YO Hideto~ W~ A

Members
HIRAI Masanori If it lE *'2ISHII Noriyoshi nit~fl~
KISHIDA Takashi *133~i
MURATA Jiro iff 133
rm
OKADA Kensuke [i'liJ133~1i'
TABARU Tsuguchika 133 }Jj( ~ ~~TANIDA Kiyoshi :e:-133~
WATANABE Yutaka iii :ill
1ft
YOKKAICHI Satoshi ImBm 'Itt*-!j[
I CHIHARA Takashi m}Jj(
JINNOUCHIOsamu ~! I*Jfl~
MIZOI Yutaka
iti~
NAITO Kenichi l*Jiii~ SAITO Naohito ~iii@:A
TAKETANI Atsushi ¥r:e:~
WATANABE Yasushi iii jI
E!t
YASUI Yoshiaki ~itN.~

7.

Visiting Members
AKIBA Yasuyuki f:k ~ ~ Z(KEK)
ALEKSEEV Igor
(Phys. Dept. , BNL, USA)~(ColI. Sci., Rikkyo Univ.)
ANDO Yoshiaki ~ iii
1f (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
AOI Nori W it
ASAI Masato ~~ it ~ A (J AERI)AS AMI Hiroyasu i~?HJ: ~L 1~ (KEK)
ASAKAWA Masayuki i~ 111 IE Z (Fac. Sci. , Kyoto Univ.)
BAUMANN Thomas(Natl. Puperconducting Cycl. Lab., Michigan State Univ., USA)BAZIN Daniel(Natl. Puperconducting Cycl. Lab. , Michigan State Univ., USA)
BECK F. A.
(CRN, France)
BENTZ Wolfgang(Dept. Phys. , Grad. Sch. Sci. , Univ. Tokyo)
BHANG Hyong Chan
(Dept. Phys., Seoul Natl. Univ., Korea)
BROG LIA R.
(U niv. Milano, Italy)
BROOKS Melynda(LANL, USA)
(Dept. Phys. , State University New York, Stony Brook, USA)
BURWARD-HOY Muriel Jane
CASTEN Rick(Phys. Dept. , BNL, USA)CHUJO Tatsuya 9=J 11* Ji -til (Phys. Dept., BNL, USA)COLO Gianluca(Univ. Milano, Italy)
CRIST Norman(Columbia Univ. , USA)DOMBRADI Zsolt(Inst. Nucl. Res. Hung. Acad. Sci. , Hungary)
DOOI Makoto 1it it~(Inst. Phys., Univ. Tsukuba)
ELEKES Zoltan(Inst. Nucl. Res. Hung. Acad. Sci., Hungary)
FLOCARD Hubert(Div. Phys. Theor., Inst. Phys. Nucl. , France)
FUCHI Yoshihide i~U~f Jij(KEK)
FUJII Hirotsugu iii it 7i:.
(Grad. Sch. Arts Sci. , Univ. Tokyo)
FUJIKAWA Kazuo iii}ll to 515 (Fac. Sci., Univ. Tokyo)
FUKUDA Mitsunori t{i; 133 7t JII~ (Grad. Sch. Sci., Osaka Univ.)

a

*-

359

FUKUDA Tomokazu t~ B3 ~ to (KEK)
FULOP Zsolt(Inst. Nucl. Res. Hung. Acad. Sci., Hungary)
FURUTAKA Kazuyoshi iJ ~ to t~ (JAERI)GAL Janos(Inst. Nucl. Res. Hung. Acad. Sci. , Hungary)
GELBERG Adrian(Koln Univ., Germany)
GONO Yasuyuki ~H~ Jl j/~ Z (Fac. Sci., Kyushu Univ.)
HAMAMOTO Ikuko ?*W -=f (Lund Inst. Technol. , Univ. Lund, Sweden)
HATSUDA Tetsuo f}] ill rg- ~ (Fac. Sci ., Kyoto Univ .)If[ t~t (JAERI)
HAYASHI Naoki ~*%=Jf(Dept . Phys. , Grad. Sch. Sci., Univ. Tokyo)
HAYASHIGAKI Arata ~*:tlf
HIKASA Kenichi B:Ii 11 (Grad. Sch. Sci., Tohoku Univ.)
HIRANO Tetsufumi
It rg- -.!J:. (Dept . Phys. Grad. Sch. Sci. , Univ. Tokyo)
HOMMA Kensuke
Fa' ~ *m (Fac. Sci., Hiroshima Univ .)HORIUCHI Hisashi :ifte I*J
m! (Fac. Integr. Human Studies, Dept. Fund . Sci., Kyoto Univ .)HOTTA Tomohiro :ifte ill ~ i$ (Grad. Sch. Arts Sci. , Univ. Tokyo)(Grad. Sch. Arts Sci., Univ. Tokyo)
ICHIMURA Munetake m;!-t
IEKI Kazuo~ to ~(ColI. Sci. , Rikkyo Univ.)(Fac. Sci. , Kyoto Univ.)
IMAI Kenichi ~ #IMOTO Michiko #j1[ -=f(ColI. Sci. Technol. , Nihon Univ.)
ISHII Tetsuro 15 # rg-~}j (J AERI)(Tokyo Inst. Technol.)
ITABASHI Kenta ~~;{t 11
IWASAKI Masahiko E W~ :fIt"& (Tokyo Inst. Technol.)IZUMI Hideaki ill 7.K
SjJ(Grad. Sch. Sci., Osaka Univ.)
JIN Genming WT
11 SjJ (Inst. Mod. Phys., Chin. Acad. Sci., China)
KAKI Kaori ~ ~l :N ~ (Fac. Sci. , Shizuoka Univ.)(Inst. Nucl. Res. Hung. Acad. Sci., Hungary)
KALINKA Gabor
KASAGI Jirota :Ii*?5~~* (Lab. Nucl. Sci. , Tohoku Univ.)
KATO Seigo 110 iii D:g. (Fac. Ed. , Yamagata Univ.)
KIM Jong Chan i:~l Jf(Dept . Phys., Seoul Nat!. Univ., Korea)
KISTENEV Edouard(Phys. Dept. , BNL, USA)
KIYO Yuichiro ¥~ 1ft-~~ (Grad. Sch. Sci., Tohoku Univ.)
KODAIRA Jirou IJ\?5 ~~ (Fac. Sci. , Hiroshima Univ.)
KOIKE Yuji IJ\ ¥ili 1ft F1J (Fac. Sci. , Niigata Univ.)
KUMANO Shunzo ft~ It 1& ~ (Fac. Sci. Eng., Saga Univ.)
KUNIHIRO Teiji ~ 5]" 'It(Yukawa Inst. Theor. Phys., Kyoto Univ.)
KUSAKARI Hideshige 1ji)(1j ~ ~ (Fac. Ed., Chiba Univ.)
LIU Guanhua ~~J(t iff(Inst. Mod. Phys., Chin. Acad. Sci. , USA)LIU Zhong(Inst. Mod. Phys. , Chin. Acad. Sci. , China)
LOMON Earle(Massachusets Inst. Techno!. , USA)
LOUKIANOV Serguei(Flerov Lab. Nucl. React. , Joint Inst. Nuc!. Res., Russia)
LUCCIO Alfredo(Phys. Dept., BNL, USA)
MAO Yajun(Inst. Mod. Phys., Chin. Acad. Sci., China)
MATSUDA Satoshi 11 ill
rg- (Dept. Fund. Sci., Fac. Integr. Human Studies, Kyoto Univ.)
MATSUI Tetsuo 11 # rg- ~ (Grad. Sch. Arts Sci., Univ. Tokyo)
MATSUYANAGI Kenichi t~ t~n 1iJf (Fac. Sci. , Kyoto Univ.)
MENGONI Alberto(Phys. Div. , ENEA , Italy)
MIAKE Yasuo = SjJ ~ ~~ (Inst. Phys., Univ. Tsukuba)
MIDORIKAWA Shoichi ~J<)l 1 ~ (Fac. Eng. , Aomori Univ .)~ IlK(Korea At. Energy Res. Inst. , Korea)
MIN Byung-Joo ~MITARAI Shiro fill~7Jt;t~~ (Fac. Sci., Kyushu Univ.)
MIYAMA Masanori i* LlJ .lE *2. (Fac. Sci. , Tokyo Metrop. Univ.)
MIYATAKE Hiroari g
~ tIL
(KEK)
MOLLER Peter(LANL, USA)MORII Toshiyuki ~ # 1& 11' (Fac. Human Develop. , Kobe Univ.)
MORIKAWA Tsuneyasu ~}l 1 'l:g 1i: (Fac. Sci., Kyushu Univ.)
MORINOBU Shunpei ~ 1~ 1&(Fac. Sci., Kyushu Univ.)~*
J! (ColI. Sci. , Rikkyo Univ.)
MOTOBAYASHI Tohru**+* * - * m:
*
*

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+

=

m:

* +

360

MOTTELSON Ben R.
(Nordita, Denmark)
MUELLER Ludwig(Phys. Dept. , Univ. Padoba, Italy)~(Natl. Inst. Radiol. Sci.)
MURAKAMI Takeshi iJ'j J:
MURAKAMI Hiroyuki iJ'j J: r-i§- Z (ColI. Sci., Rikkyo Univ.)
NAGAE Tomofumi 71<. rI ~D X (KEK)
NAGAI Yasuki 71<. #- ~ 1M (RCNP, Osaka Univ.)
NAGAMIYA Shoji 7]( g JE
(KEK)
NAKAJIMA Mitsuo 9=I!i!J 7t:1C (Grad. Sch. Nagatsuta, Tokyo Inst. Technol.)
NAKAMURA Shogo 9=I iJ'j 1£:g. (Fac. Ed., Yokohama Natl. Univ.)
NAKAMURA Takashi 9=I iJ'j ~l P] (Tokyo Inst. Technol.)
NAKAMURA Masanobu 9=I iJ'j JE 1~ (Fac. Sci., Kyoto Univ.)
NAKAYAMA Shintaro 9=IUJf8*f!~ (Fac. Integr. Arts Sci., Univ. Tokushima)
NIIZEKI Takashi fJT t*l~l(Tokyo Kasei Univ.)
NISHIMURA Jun "® iJ'j¥¥ (Cen. Integr. Res. Sci. Eng. , Nagoya Univ.)
NONAKA Chiho If 9=I T f! (Fac. Sci. , Hiroshima Univ.)
NORO Tetsuo If g :gr:1C (RCNP, Osaka Univ.)
ODAHARA Atsuko IJ'\83)Jj(JJ-=f (Nishinippon Inst. Technol.)
OGAWA Masao IJ'\ )11 ~ 1:. (Tokyo Inst. Technol.)
OGAWA Akio IJ'\]l1 BJt 1:. (Phys. Dept., BNL, USA)OHSIMA Kazuto -}(~!1!; - A (Gunma Natl. ColI. Technol.)
OKAMURA Hiroyuki l1Ii1 iJ'j "51. Z (Fac. Sci. , Saitama Univ.)
ONISHI Hiroaki -}("® 7i: I3Ji (Phys. Dept. , BNL, USA)OOISHI Ryutaro -}(Eii*f!~ (Inst. Phys. , Univ. Tsukuba)
ORIHARA Hikonojo ~)Jj(~ZZJS (Cycl. Radioisot. Cen., Tohoku Univ.)
OSHIMA Masumi -}(!i!J ~ rn: (JAERI)
OUTA Haruhiko r.t 83~(KEK)
PAN Qiangyan it~m:'5(Inst. Mod. Phys., Chin. Acad. Sci. , China)
PASCUZZI Edward(Phys. Dept., BNL, USA)PENIONZHKEVICH Iouri(Flerov Lab. Nucl. React. , Joint Inst. Nucl. Res., Russia)
PIERROUTSAKOU Dimitra(Sezione Napoli (INFN) , Italy)
REN Zhongzhou if
9=I iHI (Nanjing Univ. , China)(Tohoku Pharm. Univ .)SAITO Koichi ~ ~ ~ SAKAGUCHI Harutaka ~ D~l(Fac. Sci., Kyoto Univ.)"51. Z (Fac. Sci. , Osaka City Univ.)
SAKURAGI Hiroyuki t~
SAKURAI Hiroyoshi t~ #- tf fi (Dept. Phys. , Grad. Sch. Sci. , Univ. Tokyo)
SASAKI Shoichi 16.:4 *$(Dept. Phys., Grad. Sch. Sci. , Univ. Tokyo)
SATO Hikaru 1tc ~815 (KEK)
SATO Susumu 16.: ~J!t (Inst. Phys. , Univ. Tsukuba)
SAWADA Shinya i' 83 ~ ill (KEK)
SCHAEFER Markus(Phys. Inst., Univ. Goettingen, Germany)
SCHAFER Andreas(Inst . Theor. Phys., Univ. Regensburg, Germany)
SCHMIDT-OTT Wolf-Dieter(Phys. Inst. , Univ. Goettingen, Germany)
SEDERWALL Bo(Royal Inst. Technol., Sweden)
SEKIMOTO Michiko t*l*~*D-=f (KEK)
SHIBATA Toshiaki ~ 83 5f1J I3Ji (Tokyo Inst. Technol.)
SHIGAKI Kenta ;=t- j:~ ~(KEK)
SHIMIZU Hajime 1W 7)(~(Fac. Ed., Yamagata Univ.)
SHIMIZU Yoshifumi 1W 7)( .& X (Fac. Sci., Kyushu Univ.)
SHIMODA Tadashi r 83
1£ (Grad. Sch. Sci. , Osaka Univ.)
SIGNORINI Cosimo(Phys. Dept. , Univ. Padoba, Italy)
STROE Lucian(Phys. Dept. , Univ. Padoba, Italy)
SUGAWARA Masahiko -g:)Jj( ~ ~ (Chiba Inst. Technol.)
SUGITATE Toru :f~ fL
11& (Fac. Sci. , Hiroshima Univ.)
SUN Zuxun(China Inst. At. Energy, China)
SUZUKI Yasuyuki ~~1i: Z (Fac. Sci., Niigata Univ.)
SUZUKI Katsuhiko r~
52: ~ (Dept. Phys. , Grad. Sch. Sci., Univ. Tokyo)
SUZUKI Toshio ~~fi& ~ (Fac. Eng. , Fukui Univ.)

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361

TAJIMA Yasuhisa EEl fib }iff 0.. (Cycl. Radioisot. Cen., Tohoku Univ.)
TAKADA Eiichi ~ EEl(Natl. Inst. Radiol. Sci.)(Inst . Space Astronaut. Sci.)
TAKAHASHI Tadayuki ~;jt ,~, ¥TAKEMOTO Hiroki
7i.
(JAERI)(Grad. Sch. Sci., Tohoku Univ.)
TAKIGAWA Noboru iii)ll
TAKIZAWA Makoto ~~~JOC(Showa ColI. Pharm. Sci.)
TAMIl Atsushi N': if"{¥ (Fac. Sci., Univ. Tokyo)
TANAKA Masahiko EEl $ ~ ~ (KEK)
TANOKURA Atsushi EEltff ~ ~.t (Fac. Sci. Technol., Sophia Univ.)
TERAKAWA Atsuki ~ JII . . tM (Cycl. Radioisot. Cen., Tohoku Univ.)
TOYAMA Takeshi
LlJ
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(KEK)
TOYOKAWA Hidenori ':')1 1 ~J11 (JASRI)
UEMATSU Tsuneo tl tl '\:§: ~ (Dept. Fund. Sci., Fac. Integr. Human Studies, Kyoto Univ.)
UENO Hideki 1:. tff{n (Lab. Nucl. Studies, Fac. Sci., Osaka Univ .)UNO Masahiro
tff iE 7i. (Min. Ed., Culture, Sports Sci. Technol.)
WAKAMATSU Masashi ~ f~ iE;=t (Lab. Nucl. Studies, Fac. Sci., Osaka Univ .)WAKASA Tomotsugu ~ 3~ ~ Ifflm (RCNP, Osaka Univ .)WHITE Sebastian(Phys. Dept., BNL, USA)XU Shuwei 1~~j ~(Inst. Mod. Phys., Chin. Acad. Sci., China)-Ii! (Fac. Eng., Fukui U niv . Technol.)
YAMANISHI Teruya LlJ [9YAMASHITA Yoshiki LlJ T 7i tM (Hirosaki Univ.)(Tokyo Women's Chr. Univ.)
YAZAKI Koichi 1ft;. i1J~ ~ YOSHIMURA Koji E *t rt6 P] (Int. Cen. Element . Part. Phys., Univ. Tokyo)
YOSHINAGA Naotaka E 71<. ~ -1f:. (Fac. Sci., Saitama Univ.)YOSOI Masaru W.~if 11 (Fac. Sci., Kyoto Univ.)~ JJE.
(Inst. Mod. Phys., Chin. Acad . Sci., China)
ZHANG Yu-Hu
IJ, *1 (Inst. Mod. Phys., Chin. Acad . Sci., China)
ZHOU Xiaohong mJ
ZHU Lihua(China Inst . At. Energy, China)

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Trainees
ADACHI Yusuke JE fL~(Dept. Phys. , Grad. Sch. Sci., Univ. Tokyo)
BABA Hidetada ,~:t~,'if!, (ColI. Sci., Rikkyo Univ.)
DEMICHI Kimihiko tB:@: f= ~ (ColI. Sci., Rikkyo Univ.)
ENOKIZONO Akitomo 11 ~ BE ~ (Fac. Sci., Hiroshima Univ.)
FUKAO Yoshinori i* ~ :ff *-2. (Fac. Sci., Kyoto Univ.)
FUKUCHI Tomonori 1~ ±Ih *0 ~Ij (Fac. Sci., Kyushu Univ.)
GOMI Tomoko Ii. p,* ~~ -=f (ColI. Sci., Rikkyo Univ.)
HACHIYA Takashi ~~ ~(Fac. Sci. , Hiroshima Univ.)
HASEGAWA Hirokazu -lit~)llrt6- (ColI. Sci ., Rikkyo Univ.)
IlilJIJ 51:.
(Tokyo Inst. Technol.)
HAYASHI Takeshi
if - 'if (Tokyo Inst. Technol.)
HIRAI Kazuyoshi
1~ ~;=t(Dept. Phys., Grad. Sch. Sci. , Univ. Tokyo)
HIRAMATSU Takashi
IKEDA Hiroshi ?tl! EEl
83 (Tokyo Inst. Technol.)
INOUE Masaki if 1:. iE ~j (Fac. Sci., Kyushu Univ.)
ISHIDA Tomoyuki 15 EEl ~ Z (Dept . Phys., Grad. Sch. Sci., Univ. Tokyo)
KAJIHARA Fukutaro t~ml1~:t:f!~ (Dept. Phys. , Grad. Sch. Sci., Univ. Tokyo)
KAMIHARA Nobuyuki t$ ml1§" ¥(Tokyo Inst. Technol.)
KANEKO Emi i: -=f ~ ~ (ColI. Sci., Rikkyo Univ.)
KANG Byonghwi(Dept. Phys., Seoul Natl. Univ., Korea)
KANNO Shouko 1f tff 1$ -=f (ColI. Sci. , Rikkyo Univ.)
KATAYAMA Takeshi 11 LlJ lEt ±(Tokyo Inst. Technol.)
KAWASAKI Hiroaki iPJ i1J~ i$ iir (ColI. Sci., Rikkyo U niv.)
KIM Jungho(Dept . Phys. , Seoul Natl. Univ ., Korea)
KIYOMICHI Akio ?ff:@: SjJ ~ (Inst. Phys., Univ. Tsukuba)
KOMIYAMA Takeshi IJ'\gLlJlEt± (Dept . Phys., Grad. Sch. Sci., Univ. Tokyo)
KONDO Yosuke ili: Ii i$ 1r (Tokyo Inst. Technol.)
KUBOKI Hironori j\J~*rt6Jj] (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)

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362

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KUROKI Yoshiaki !J.
~ BE(Inst. Phys. ) Univ. Tsukuba)_ LIM Heejoong(Dept. Phys. ) Seoul Natl. Univ. ) Korea)
MAEDA Yukie lW 83 ¥.m: (Dept. Phys. , Grad. Sch. Sci., Univ. Tokyo)
MATSUYAMA Yuuichi tt:- LlJ fa (ColI. Sci.) Rikkyo Univ.)
MIURA Motooki -=: iffi 7C ~i (Tokyo Inst. Technol.)
MIYAJIMA Akari g ~ SA -='- (Tokyo Inst . Technol.)
MOTOMURA Shinji
tt 1§ is (Fac. Sci. , Kyushu Univ.)
MUTO Ryotaro iEtiii;,t:.*.E~ (Fac. Sci., Kyoto Univ.)
NAKAMURA Tomoaki r:p tt ~ BE (Fac. Sci., Hiroshima Univ.)
NARUKI Megumi ~2. (Fac. Sci., Kyoto Univ.)(ColI. Sci., Rikkyo U niv.)
N ARUSHIMA Koichi ~ ~~ J)] OHKUMA Kazumasa~~
1£ (Fac. Human Dev. , Kobe Univ.)
OKADA Shinji 1m] 83 1§(Tokyo Inst. Technol.)ONG Hooi Jin(Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
W it ~ (Dept. Phys., Grad. Sch. Sci. , Univ. Tokyo)
ONISHI Takeo
ONO Masaya IJ'\ If ~ i:Q (Inst. Phys., Univ. Tsukuba)
OYAMA Satoshi 7::. LlJ
Wi: (Dept. Phys., Grad . Sch. Sci. , Univ. Tokyo)
SAITO Takaaki ~ Jli ~ I=1.I3 (Dept. Phys. , Grad . Sch. Sci. , Univ. Tokyo)
SAITOU Akito ~ Jli SA 1t (ColI. Sci. , Rikkyo Univ.)
SAKUMA Fuminori 1tc)\ra~9:.~ (Fac. Sci. , Kyoto Univ.)
SASAKI Takafumi 1tc4 *~i)( (Fac. Sci.) Kyushu Univ.)
SATO Hiroki 1tc iii tt *2. (Fac. Sci. , Kyoto Univ.)(Tokyo Inst . Technol.)
SATO Masaharu 1tc iii ~q
SUDOH Kazutaka ~J[ iii to f§t (Fac. Human Dev. , Kobe Univ.)
SUGIMOTO Takashi ifb(Tokyo Inst. Technol.)(Fac. Sci. , Hiroshima Univ.)
SUGITA Noriyuki ifb 83 '§" ZSUZUKI Miwako ~fJ*~5fO-T (Inst. Phys., Univ. Tsukuba)
SUZUKI Takatoshi ~fJ~i ~(Dept. Phys., Grad. Sch. Sci. , Univ. Tokyo)lJ. (ColI. Sci. , Rikkyo Univ.)
TAKESHITA Eri 1t T
TANAKA Shuichi 83 r:p mJ (Fac. Sci., Kyushu Univ.)
TOGAWA Manabu )7}][1":!f (Fac. Sci., Kyoto Univ.)
TOJO Junji}II& is (Fac. Sci., Kyoto Univ.)TORII Hisayuki ,~#)\ iT (Fac. Sci., Kyoto Univ.)
TSURUOKA Hiroshi t~ 1m] fa ± (Inst . Phys. , Univ. Tsukuba)
UCHIGASHIMA Nobuyuki I*J 7" ~~Z (Dept. Phys. , Grad. Sch. Sci., Univ. Tokyo)
WAKABAYASHI Yasuo :E if* ~ ~ (Fac. Sci., Kyushu Univ.)
YAKO Kentaro *[o]~*.E~ (Dept. Phys. , Grad. Sch. Sci. , Univ. Tokyo)
LlJ
fg- (Tokyo Inst. Technol.)
YONEYAMA Tetsu

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Head
TANIHATA Isao~:t1B ~ ~Members
FANG Deging
IDEGUCHI Eiji #-¥D*is
ISHIDA Yoshihisa D 83 it )\KOHAMA Akihisa IJ'\ i~ i:+ ~KUSAKA Kensuke B T il ::tt
MOCHIZUKI Yuko ~ Ji if -=f
NAKATSUKASA Takashi r:p ~~NISHIMURA Shunji W tt 1~
OZAWA Akira IJ'\ iR~i
OHNISHI Tetsuya
W fg- tt!
WAKUI Takashi ij #;=t,
YAMAZAKI Toshimitsu LlJ w~ ~ 7t**=

FUKUYAMA Yoshimitsu fM LlJ 1$ 7t
IIDA Kei iN. 83
KANUNGO Rituparna
KORSHENINNIKOV Alexei A.
MATSUO Yukari t~fi§Ei3~tlj
MORIMOTO Kouji ~¥ PJNISHI Yuji 1!9~
NISHIMURA Mizuki W tt ~ Ji
ONISHI Takashi
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Visiting Members
ABE Yasuhisa ~ilJ:g:~:m ~ (Yukawa Inst. Theor. Phys., Kyoto Univ.)
ADACHI Shizuko q; Ji m- -T (ICFD)
AHMADY Mohammad(Western Ontario Univ., Canada)
AOKI Yasuo W i*:;t: (Fac. Sci., Univ. Tsukuba)
AOYAMA Shigeyoshi -W LlJ~(Kitami Inst. Tech.)
ARITOMO Yoshihiro :ff R & y~ (J .I. N.R. , Russia)
BOLBOT Michael(Notre Dame Univ. , USA)
BOYD Richard(Ohio Univ ., USA)
BROCKMANN Roff (Inst. Phys., Univ. Mainz, Germany)
CASARES Antonio(Oak Ridge Lab., USA)
CRUCCERU llie(Horia Inst. Eng., Romania)(Bhabha At . Res. Cen. , India)
DATAR Vivek
DAVID Dean J.
(CALTEC, USA)DEMYANOVA Alla S. (Kurchatov Inst . At. Energy, Russia)
DOKE Tadayoshi ~,'iP, ~ (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
ENYO Yoshiko J!S W. it -=f (Cen. Nucl. Study, Univ. Tokyo)
FAMIANO Michael(Ohio State Univ., USA)FOMITCHEV Andrei(JNRF, Russia);:f (RCNP, Osaka Univ .)FUJIWARA Mamoru Ji mt
FULOP Zsolt(ATOMKI, Hungary)
GACSI Zoltan(ATOMKI, Hungary)
GEISSEL Hans
(GSI, Germany)
GIURGIU Mircea(Horia Inst. Nucl. Eng., Romania)
GOLOVKOV Mkheil S.
(Kurchatov Inst. , Russia)
GONCHAROV Sergei A.
(Kurchatov Inst., Russia)
GORIELY Stephanoe(Inst. Astron., Belgium)
GORINE Alexander(IHEO , Russia.)
GOSWAMI Ranjana(Variable Energy Cycl. Cen. Calcutta, India)
GUNJI Shuichi ;g~ P] 11~ (Fac. Sci., Yamagata Univ .)HARADA Toru mt EB~t(Fac. Sci. Inf. , Sapporo Gakuin Univ .)HASEBE Nobuyuki ttft:g:~ f$1T (Fac. Sci. Eng. , Waseda Univ .)HIEN Nguyen Thuc
(Hanoi U niv., Vietnam.)
HIRENZAKI Satoru .J:tjlilJ~ 'I! (Fac . Sci., Nara Women's Univ.)
HONMA MichiorEl~ :1m a(Univ. Aizu)
HORIBATA Takatoshi :ifte mffi -1f. f~ (Fac. Eng., Aomori Univ.)
HORIGUCHI Masakatu :ifte 0 iE M} (Horiguchi Ironworks)
HORIUCHI Hisashi :ifte pq
7N! (Fac. Sci., Kyoto Univ.)
IKEDA Akitsu itP. EB tj( if (Shizuoka Inst . Sci. Tech.)
IKEDA Kiyomi ?ill EB~
ISHIMOTO Shigeru D 5C
(KEK)(Fac. Sci. , Univ. Tokyo)
ITAGAKI Naoyuki 1& ±l[ i1I Z
ITAHASHI Kenta 1& ift ~(Fac. Sci., Tokyo Inst. Technol.)
IWAMOTO Akira :fi
BE (Tokai Res. Estab., JAERI)IWASA Naohito :fi ftc i1I i= (Fac. Sci., Tohoku Univ.)(Nishogakusya Univ .)IWASAKI Aiichi :fi IU~ ~ IZUMIKAWA Takuji jjt JII £j[ P] (Fac. Sci., Niigata Univ. )IZUYAMA Takeo fttR LlJ ~:;t: (Fac. Sci. , Toho Univ.)
KAMIMURA Masayasu J:. ft iE(Fac. Sci., Kyushu Univ .)KANEKO Kazuya :ili: -T to ill (Kyushu Sangyo Univ. )KATO Kiyoshi lJO Ji ~ 7i (Fac. Sci. , Hokkaido Univ.)
KATORI Kenji If[ JfJ. jt
KIKUCHI Jun ~ itP.
}II& (Sci. Eng. Res. Lab ., Waseda Univ.)
KIMURA Kikuo *ft%~it (Fac. Eng., Nagasaki Inst. Appl. Sci .)KOBAYASHI Toshio IJ'\
i~ it
(Fac. Sci. , Tohoku Univ.)

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KOLATA James(Notre Dame Univ., USA)
KOSSENKO Grigori(OMSK State Univ., Russia)
KOURA Hiroyuki Ij, iii Jl Z (Fac. Sci. Eng. , Waseda Univ.)
KOUZMINE Evgueni(Kurchatov Inst. , Russia)
KRASZNAHORKAY Attila(ATOMKI, Hungary)
KUMAGAI Hidekazu ~~ ~ f;; *0
KUMARU Suresh(Bhabha At. Res. Cen., India)
LE HONG Khiem(Inst. Phys. , Natl. Cen. Sci. Technol. , Vietnam)
LU Hongfeng(Peking Univ., China)
MIZUSAKI Takahiro
m~ ~ 115(Fac. Sci., Univ. Tokyo)
MARUYAMA Koichi 1L LlJ 1~ (Inst. Nucl. Study. , Univ. Tokyo)
MARUYAMA Tomoyuki 1L LlJ ~ ¥(Nihon Univ.)
MATSUOKA Nobuyuki t111YiJ 1$ iT (RCNP, Osaka Univ.)
MATSUTA Kensaku tl ~ 1l
(Fac. Sci. , Osaka Univ.)
MATSUYANAGI Kenichi 1~ tDn ~Jf (Grad. Sch. Sci., Kyoto Univ.)
MATSUZAKI Masayuki t1 m~ J§ Z (Fac. Ed., Fukuoka Univ. Ed.)
MATSUYAMA Yoshitaka t1 LlJ 7i -#f. (Inst. Nucl. Study., Univ. Tokyo)
MENG Jie(Peking Univ., China)(Fac. Eng. , Aomori Univ. )MIDORIKAWA Shouichi k~)lI:$: MINAMISONO Kei
III§(Fac. Sci., Osaka Univ.)
MINAMISONO Tadanori
III ,liE', ~Ij (Fac. Sci. , Osaka Univ.)
MITTING M.
(GANIL, France)
MIHARA Mototugu =£ Iffl~ (Fac. Sci. , Osaka Univ.)
MIRGULE Ekanath Tanu
(Bhabha At. Res. Cen., India)
S)3 Eft fi,/j(Fac. Sci. , Univ. Tsukuba)
MIYAKE Yasuo
MIYAMURA Osamu g tt
11~(Fac. Sci. , Hiroshima Univ.)
MIYACHI Takashi g it!!
-#f. (Fac. Sci. Eng., Waseda Univ.)
MOMOTA Sadao Bffift~~ (Kochi Univ. Technol.)
MORITA Hiroaki ~ ffi ~.L. S)3 (Horiguchi Ironworks)
MURAOKA Mitsuo tt I1YiJ 7t ~ (Fac. Eng., Aomori Univ.)
MUTA Atsushi :$. ffi
l.!f. (Inst. Phys., Univ. Tsukuba)
MUTO Kazuo m: Jii - tl (Inst. Sci., Tokyo Inst. Technol.)
NAKADA Hitoshi J:fl ffi
1= (Fac. Sci., Chiba Univ.)
NOJIRI Yoichi ~ JJL if (Kochi Univ. Technol.)
NOMURA Izumi ~ tt *0 jjt (NIFS)
OGAWA Kengo Ij,)l1 ~:g. (Fac. Sci. , Chiba Univ.)
OGAWA Yoko Ij,)II if r(Fac. Sci. , Osaka Univ.)(Kurchatov. Inst., Russia)
OGLOBLIN Alexei A.
OHTA Masahisa
ffi
0. (Fac. Sci. , Konan Univ.)
OHTSU Hideaki
if f;; BJt (Fac. Sci., Tohoku Univ.)
OHTSUBO Takashi
if ~i (Fac. Sci. , Niigata Univ.)
OMATA Kazuo Ij, 1*= *O:;R: (Inst. Nuc!. Study, Univ. Tokyo)
ONISHI Naoki
1§ 11l2: (Fac. Eng. , Yamanashi Univ.)
ONO Akira Ij, ~:$: (Fac. Sci. , Tohoku Univ.)
OKUDA Takashi ~ ffi .. ~ (Fac. Sci., Tohoku Univ.)
001 Makito *#7J*'cA (Dep. Phys. , Sch. Sci., Univ. Tokyo)
ORYU Shinsho fit. fL 1!f 1* (Fac. Sci. Techno!., Tokyo Univ. Sci.)
j-~ -#f. is(Fac. Sci. , Univ. Tokyo.)OTSUKA Takaharu
OYAMATSU Kazuhiro
tl *0 115 (Aichi Shukutoku Univ.)
OZEKI Takashi~ *0"(Fac. Sci. , Tohoku Univ.)
PETRASCU Horia(Horia Inst. Phys. Nuc!. Eng., Romania)
PETRASCU Marius(Horia Inst. Phys. Nucl. Eng., Romania)
POLLACCO Emmanuel(EAC , France)
REN Zhang Zhou
(Nanjing Univ., China)
ROUSSEL-CHAMAZ P.
(GANIL, France)
SAGAWA Hiroyuki it JII ~.L. ¥ (Cen. Math. Sci. , Univ. Aizu)
SAKAGUCHI Harutaka ~ 0 is ~i (Grad. Sch. , Kyoto Univ.)

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SAKAI Hideyuki i@ it 3i:. iT (Fac. Sci. , Univ. Tokyo)
SAKURAI Hirohisa tf it ~ (A (Fac. Sci., Yamagata Univ.)
SAMANTA Chhanda(Sala Inst. Nucl. Phys. , Calcutta, India)
SARHAN Badawy(Cairo Univ., Egypt)
SASA Hiromasa ftr. 4 tt 1& (Horiguchi Ironworks)
SATO Hiroshi ftr. ni
tt (Seikei Univ.)
SATO Kazuhiro ftr. ni *O?$ (Tokyo Fire Dept.)(Dept. Phys. , Tohoku ColI. Pharm.)
SATO Kenichi ftr. ni ~ SAVAJOLS H.
(GANIL, France)
SCHROEDER Lee S.
(Laurence BerKeley Lab. , USA)
:It:. (California Univ., USA)
SEKI Ryoichi ~SERRA Milena(Tech. Munich Univ., Germany)
SHERRIL Bradley M.
(Michigan State Univ., USA)SHEN Caiwan(Dept. Nucl. Phys., China Inst. At. Energy, China)
SHIBATA Mitihiro ~ B3 l-' ~ (Dept. Energy Eng. Sci. , Nagoya Univ.)
fiji (Sci. Eng., Aoyama Gakuin Univ.)
SHIBATA Toru ~ B3
SIGNORINI Cosimo(INFN, Italy)
SMITH Michael(Inst. Oak Ridge, USA)
5jj:::K (RCNP, Osaka Univ.)
SUGANUMA Hideo -g
SUGAWARA Masahiko -g§ ~ (Fund . Sci., Chiba Inst. Technol.)
SUMIYOSHI Kohsuke ft B 7t 1f- (Numazu College Technol.)
SUMMERER Klaus(GSI, Germany)SUZUKI Akihiro ~ii
BE fJL (Shinshu Univ.)
SUZUKI Hideyuki ~ii
3i:. iT (KEK)SUZUKI Takeshi ~ii
1l (Fac. Sci. , Niigata Univ.)tg(Fac. Sci. , Kanazawa Univ.)
SUZUKI Tsuneo ~ii{~~(ColI. Hum. Sci. , Nihon Univ.)
SUZUKI Toshio ~ii~ 5J5(Sci. Eng., Fukui Univ.)
SUZUKI Toshio ~ii
SUZUKI Yasuyuki ~ii'§' Z(Fac. Sci. , Niigata Univ.)
TACHIBANA Takahiro fl%~ tt(Sen. High Sch. , Waseda Univ.)
TAKAHASHI Yoshiyuki ~;fit ~ ¥(Alabama Univ. , USA)--=- (Fac. Sci., Osaka Univ.)
TAKAHASHI Yutaka r\§J tit
TAKANO Masatoshi JI ff 1£;f1J (Fac. Sci. Eng. , Waseda Univ.)
TAKEMASA Tadashi
1& 7'" ± (Kyoto Univ. Ed.)
TAKIGAWA Noboru ¥i]ll~(Fac. Sci. , Tohoku Univ.)
TAJIMA Naoki B3 W,~
1it (Fac. Sci., Fukui Univ .)TANABE Kazuko B3:ill fo -T (Otsuma Women's Univ.)
TANAKA Kazuhiro B3 $ fo rt (Med. Dept. , Juntendo Univ.)
TANAKA Takaya B3 $ # ~ (Fac. Sci., Saitama Univ.)
TERASAWA Kazuhiro ;!f ¥R fO?$ (Fac. Sci. Eng., Waseda Univ.)
TER-AKOPIAN G.
(Dubna, Russia)
TEZUKA Hirokazu .:f j~ ?$ (Dept. Liberal Arts. Fac. Literature, Toyo Univ.)
THIROLF P.
(Univ. Munchen, Germany)
TOHYAMA Mitsuru Ji LlJ
ifdlJ(Kyorin Univ.)
TOKANAI Fuyuki r~ Pt ~ 1it (Fac. Sci., Yamagata Univ .)TOKI Hiroshi ± rultt (RCNP, Osaka Univ.)
TOMODA Toshiaki 1ft:. B3 ~ ~ (Fac. Sci. , Aomori Univ.)TORBJOEN Baeck(Stockholm Univ., Sweden)
TOSTEVIN Jeffrey A.
(Univ. Surry, India)
UCHIHORI Yukio I*J:tJill ¥:::K (Inst. Rad. Sci.)
UTSUNO Yutaka *iflff ti (Tokai Res. Estab. , JAERI)UTSUNOMIYA Hiroaki *t~gfJJ,.~ (Fac. Sci. , Konan Univ.)
VARGA Kalman(lnst. Oak Ridge, USA)
WADA Takahiro fO B3 ~i 7i (Fac. Sci. , Konan Univ.)
WAKAI Masamiti ~ it 1£ j]! (Grad. Sch. Sci., Osaka Univ.)
WINKLER Martin(GSI, Germany)
WOLLNIK Hermann(Oak Ridge Lab., USA)

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366

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YABANA Kazuhiro(Fac. Sci., Univ. Tsukuba)
YAGI Hirosuke J\
i1!i ,jIf (Fac. Sci., Univ. Tsukuba)
YAMADA Shoichi LlJ 83 ~ (Fac. Sci. , Univ. Tokyo)
YAMAGUCHI Yoshio LlJ 0 :a ~ (Inst. Nucl. Study., Univ. Tokyo)
YORANN Alhassid(Yale Univ., USA)YOSHIDA Nobuaki E 83 '§' ~ (Fac. Inf., Kansai Univ.)
YOSHINAGA Naotaka E 7X fa] 1(:. (Fac. Sci., Saitama Univ.)YUZUKI Akira ifm~(Toshiba Corp.)
ZAHAR Mohamed(Dept. Phys., Notre Dam Univ., USA)ZHENG Tao
(Fac. Sci. Technol., Sci. Univ. Tokyo)
ZHOU Shan-Gi(Peking Univ., China)*

Trainees
CHIBA Masami# ~q. 7C (Fac. Sci., Tohoku Univ.)
COURALLET Delphine(Ecole Mines Nantes, France)
FUZIMURA Takeshi Ri ift-ffi (Sci. Eng., Aoyama Gakuin Univ.)
HARA Kenichiro JJR 'OO! - J!!~ (Fac. Sci. Eng. , Waseda Univ.)
HARUKI Masamichi
lE ill (Fac. Sci. Eng., Waseda Univ.)
HASHIMOTO Izumi
iJt (Fac. Sci., Osaka Univ.)
HASHIZUME Kazuaki§5(Fac. Sci. , Konan Univ.)
HIBINO Masaru B ltlff 1~ (Fac. Sci. Eng. , Waseda Univ.)
IHARA Akifumi #JJR:9EJ2.5I:. (Fac. Sci. Eng., Waseda Univ.)
ITO Hiroshi 1fr Ri i1!i E (Fac. Sci. Eng., Waseda Univ.)
KATO Tomomi 110 Ri ~(Fac. Sci. , Niigata Univ.)
KATO Toshiyuki 110 ii 1~ ¥ (Fac. Sci. Eng., Waseda Univ. )KAWA Tadahisa iilJ,'iP,:A (Fac. Sci., Osaka Univ.)
KAWAMURA Yoshie )II ift i~ 2: (Fac. Sci., Niigata Univ.)
KIHIRA Eiichi E f(Fac. Sci. Eng., Waseda Univ.)
KITANI Takao~ J: til(Fac. Sci. Eng. , Waseda Univ.)
KIYAMU Atushi %~Jit~5I:. (Fac. Sci. Eng. , Ibaraki Univ.)
KOBAYASHI Shingo IJ'\
J1t 1I; (Fac. Sci. Eng., Waseda Univ.)
KOIKE Takayuki IJ'\?ill J: Z
(Fac. Sci. Eng., Waseda Univ.)
KUDO Syuichi I ii 11~ (Fac. Sci., Osaka Univ.)
KURIYAMA Koji ~ LlJ ¥ is (Sci. Eng., Aoyama Gakuin Univ.)
MASUMURA Takahiro j:~ ift ~ i$ (Fac. Sci. Eng., Waseda Univ.)
MIYAKE Toru~f~(Fac. Sci. , Osaka Univ.)
MUTO Nobuo TIk Ri 18 til (Fac. Eng., Aoyama Gakuin Univ.)
NAGATOMO Kiyoshi ffi: 1ft:.
~(Fac. Sci. , Osaka Univ.)
NISHIKIDO Humihiko im p X"& (Fac. Sci. Eng., Waseda Univ.)
OGURA Masako IJ'\ ~ J§ -=f (Fac. Sci., Osaka Univ.)OHZEKI Kazuki~(Fac. Sci., Tohoku Univ.)
OKA Akihiro IRiJ
jib ~L (Fac. Sci. Eng., Waseda Univ .)OKUDA Takashi ~ 83 .. ;it (Fac. Sci. , Tohoku Univ.)
11~(Fac. Sci. Eng. , Waseda Univ.)
OKUDAIRA Osamu ~OZAKI Kiminori ~ 1iJ~ 0~!Z (Fac. Sci. Eng., Waseda Univ.)
SAKAGUCHI Takao t& 0 .. ~ (Fac. Sci. Eng., Waseda Univ.)
IDiX:(Fac. Sci. , Osaka Univ.)
SASAKI Makoto f1:4
SATO Kazunori f1: Ri~Ij(Fac. Sci., Osaka Univ.)
SEKIGUCHI Masatugu 1*1 0 J§ ffiim (Fac. Sci., Tohoku Univ.)
SHIMIZU Noritaka 1~ 7j'( ~Ij 1(:. (Fac. Sci., Univ. Tokyo)
SOURI Hirofumi ~&£*flj§5I:. (Fac. Sci. Eng. , Waseda Univ .)SUGIMOTO Satoshi ifb
Jf:rs (RCNP, Osaka Univ.)
TAKEMURA Atsushi t1 ift?¥ (Fac. Sci., Osaka Univ.)
TAKEMURA Haruyuki it ift
fL (Fac. Sci. Eng., Waseda Univ.)
TAKENAKA Sunao it r:p~(Fac. Sci. Eng. , Waseda Univ.)
TAKENOUCHI Masatoshi t'rzf1'1lE{~ (Fac. Sci. Eng., Waseda Univ.)
TAKEUCHI Satoshi TIk f1'1
Jf:rs (Fac. Sci. , Rikkyo Univ.)-+*m** *0m *0 SA

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TANAKA Motoyuki ffi t::p £ Z (Fac. Sci ., Waseda Univ.)
TAZAWA Shinya ffi ¥R i$ itt (Fac. Sci. , Tohoku Univ.)
TERASAWA Mariko ~i'JP]l-=f (Fac. Sci., Univ. Tokyo.)
TERUHI Shigeru ~~ B~
(Fac. Sci. Eng., Waseda Univ.)
UMEMURA Tomohiro l~ f1 ~JI ~L (Fac. Sci. Eng. , Waseda Univ.)
1~(Fac. Sci., Tohoku Univ .)UZIIE Toru .B;;
WATANABE Kiwamu iJi ill {pI Z (Fac. Sci., Tohoku Univ .)WATANABE Shigeo iJi it 7{:ft:: (Fac. Sci., Niigata Univ.)
YAKUSHIJI Takashi ~HfP~ ~ (Fac. Sci., Tohoku Univ.)
YAMADA Kazunari LlJ ffi - mt (Fac. Sci. , Rikkyo Univ.)
YAMAGUCHI Yoshitaka LlJ 0 ill ~ (Fac. Sci. , Niigata Univ.)
YAMASHITA Masaki LlJ T ~ ~t (Adv. Res. Inst. Sci. Eng. , Waseda Univ .)(Fac. Sci. Eng., Waseda Univ.)
YAMASHITA Naoyuki LlJ T @: Z
it i-f (Fac. Sci. Eng., Waseda Univ.)
YASHIRO Junichi
YOSHIOKA Hideki E IUiJ~t(Fac. Sci. Eng., Waseda Univ.)

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Applied Nuclear Physics Laboratory
Head
ASAHI Koichiro M *11=- f!~Members
KOBAYASHI Yoshio Ij" t* ~ ~MURATA Jiro f1 ffi ;);: J!mYONEDA Kenichiro *ffif@: - f!~
WATANABE Hiroshi rJi it
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UEN 0 Hideki 1:. ff~t
SATO Wataru 1£ Ii
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YOSHIMI Akihiro E J! ,~ i$* *Visiting Members
EINAGA Yasuaki-R
I3Ji (Fac. Sci. , Univ. Tokyo)
IMAI Nobuaki ~ #- i$ I3Ji (Dept. Phys. , Grad. Sch. Sci. , Univ. Tokyo)
KUBO Kenya ).... i* ~ ~ (Fac. Sci. , Univ. Tokyo)~t iK =gr
(Grad. Sch. Sci. Eng., Tokyo Inst. Technol.)
MIYOSHI Hisanori
OGAWA Hiroshi Ij,,)11 tf ffii~ (Fac. Sci. , Tokyo Inst. Technol.)
OKADA Takuya IUiJ ffi !j! -ill (Fac. Sci. , Gakushuin Univ.)
SAKAI Kenji i@ #- f@:(Fac. Sci., Tokyo Inst. Technol.)i$ (Fac. Sci. , Tokyo Univ. Sci.)
YAMADA Yasuhiro LlJ ffi=='*

Trainees
HORI Kentaro #ffi f@:*f!~ (Fac. Sci ., Tokyo Univ. Sci.)
KATSUMATA Keiichi ~ X § (Fac. Sci. , Tokyo Univ. Sci.)
MIYAZAKI Jun g 1iJ~
i-f (Fac. Sci., Tokyo Univ. Sci.):* (Fac. Sci. , Tokyo Univ. Sci.)
SAITO Takashi ~ Ii
KAMEDA Daisuke *. ffi -}( ,ill (Fac. Sci., Tokyo Inst. Technol.)(Fac. Sci. , Tokyo Inst. Technol.)
KAIHARA Jou ffi! JJj{ £7{(Fac. Sci. , Shizuoka Inst. Sci. Tech.)
OGAWA Shigeru Ij" JIIONO Yuuki Ij" ff ;f{]" fit (Fac. Sci. , Tokyo Univ. Sci.)
SHIMAZAKI Hideo 1ZJ 1iJ~~
(Fac. Sci. , Tokyo Univ. Sci.)
ISHIKAWA Yumiko E)II EI3~-=f (Fac. Sci., Tokyo Univ. Sci.)
SHIMIZU Yasunori iw 7](
Jj] (Fac. Sci. , Shizuoka Inst. Sci. Tech.)**'*Atomic Physics Laboratory
Head
YAMAZAKI Yasunori LlJ 1iJ~

Members
IKEDA Tokihiro

368

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KAMBARA Tadashi

1$ JJj{iE

KANAI Yasuyuki ~ # i¥ Z
MORISHITA Yuichiro ~Tfti - rm
NAKAMURA Takashi 9=J ft .. ;=t,o URA Masaki -)( 7~ lE 1!t
SHIMAMURA Isao ~ ft~
TERANISHI Yoshiaki ~ ® ~ 1§"

KOJIMA Takao M. IJ'\ ~ ~f ~NAKAI Yoichi 9=J # ~JJ1 NISHIDA Masami ® EB ~ ~OYAMA Hitoshi -)( ill~
TAKEKAWA Michiya
ili t!1
WADA Michiharu ~O EB ili rElrr)ll

Visiting Members
ANDO · Kozo !i: Jii IJilJIJ ~AWAYA Yohko ~~ -T(ColI. Art Design Gen. Ed., Musashino Art Univ.)i~ 11"(Dept . Phys., Tokyo Metrop. Univ.)
AZUMA Toshiyuki
CHIMI Yasuhiro ~D J! ~ ~t. (Tokai Res. Estab., JAERI)
DEPAOLA Brett(Dept . Phys., Kansas State Univ., USA)
DUMITRIU Dana
(Natl. Inst. Phys. Nucl. Eng. , Romania)
EICHLER Jorg
(Hahn-Meitner Inst . Berlin, Germany)
ENDO Atsumi :ii: Jii ~ ~ (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
FAIFMAN Mark
(Russ. Res. Cen., Kurchatov Inst. , Russia)
FUJIMA Kazumi Jii Fa' - ~ (Fac. Eng., Yamanashi Univ.)
HARA Shunsuke JJj(
i~ 11"(Dept. Gen. Ed., Tsukuba ColI. Technol.)RAYAKAWA Kazuo If!. JII - ~ (Shizuoka Inst . Sci. Technol.)
RINO Ken-ichi B!f ~(Inst. Appl. Phys., Univ. Tsukuba)
HITACHI Akira }j ill~(Kochi Med. Sch.)
HORACEK Jiri
(Charles Univ., Czech Republic)
HOSHINO Masamitsu £ H lE 7t (Grad. Sch. Sci. Eng., Sophia Univ.)
HUTTON Roger(Dept . Phys. , Lund Univ., Sweden)
ICHIMURA Atsushi mft?¥ (Inst. Space Astr. Sci.)
IGARASHI Akinori 1i+JiBJHII] (Fac. Eng., Miyazaki Univ.)
IKEDA Hiroshi 7lli EB
tt (Univ. Tsukuba)
INOKUTI Mitio # 0 ili ~ (Argonne Natl. Lab ., USA)ISHII Keishi E # ~ Z (Fac. Sci. Eng., Ritsumeikan Univ.)
ISHIKAWA Norito E JII it A (Tokai Res. Estab., JAERI)
ITO Takaomi ifr Jii ~ ~ (Grad. Sch. Arts Sci. , Univ. Tokyo)
ITOH Akio ffr Jii f* ~ (Fac. Eng., Kyoto Univ.)
ITOH Yoh ifr iii~JJ1(Fac. Sci., Josai Univ.)
IWAI Yoshio :'fi # '&:1(: (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
IWASE Akihiro :'fi il ~ 7i. (Tokai Res. Estab., JAERI)
KAGEYAMA Kensuke Ii ill i@11" (Fac. Eng., Saitama Univ.)
KAWATSURA Kiyoshi JII 00
IT[ (Fac. Eng. Design, Kyoto Inst. Technol.)ft i@(Fac. Eng., Kyoto Univ.)
KIMURA Kenji
KIMURA Mineoft ~ (Fac. Eng., Yamaguchi Univ.)
KITAJIMA Masashi ~t ~ @lr 9:. (Fac. Sci. Technol. , Sophia Univ.)
1~:1(:(Dept. Phys. , Tokyo Metrop. Univ.)
KOBAYASHI Nobuo IJ'\
KOIKE Fumihiro IJ'\ im X tt (Sch. Med., Kitasato Univ.)
KOIZUMI Tetsuo IJ'\ jJt :tg:1(: (Dept . Phys ., Rikkyo Univ.)
KOMAKI Ken-ichiro IJ'\tl:fcpJf-e~ (Grad. Sch. Arts Sci., Univ. Tokyo)
KOWARI Kenichi IJ'\ ~U ~ (Dept. Appl. Phys. Chern., Univ. Electro-Commun.)
KUROKI Kenro~ e~(Natl. Res. Inst. Police Sci.)
MATSUNAMI Noriaki t~ r& *2. BjJ (Sch. Eng. , Nagoya Univ.)
MATSUO Takashi t~ ~(Dept. Pathol., Tokyo Med. Dent. Univ.)
MATSUZAWA Michio t~ ilJ Jm ~ (Dept. Appl. Phys. Chern. , Univ. Electro-Commun.)
MITSUKE Koichiro J!~ftq:-e~ (Inst. Mol. Sci.)
MIZOGAWA Tatsumi i.}II m: E. (Wakayama Natl. ColI. Technol.)M 0 HRI Akihiro =E ~I] ~ tt
MUKOYAMA Takeshi rQ] ill~(Kansai Gaidai Univ.)
NIIGAKI Megumi *Jf ±li~(Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
NISHIMURA Tamio ® ft ~ ~ (Univ. Rome , Italy)
OHTANI Shunsuke -)( ~ 1~ 1r- (Dept. Appl. Phys. Chern., Univ. Electro-Commun.)

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369

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OSHIMA Nagayasu 7:.. ~ 71<.
(Grad. Sch. Arts Sci., Univ. Tokyo)
OKABAYASHI Norio [tij];{t ~IJ(Grad. Sch. Arts Sci. , Univ. Tokyo)
OKADA Kunihiro lUi] E8 f~ 7i: (Fac. Sci. Technol., Sophia Univ.)
OKAYASU Satoru lUi] 1i:'I'! (Tokai Res. Estab., JAERI)
OKUNO Kazuhiko ~ ff *0 ~ (Dept. Phys. , Tokyo Metrop. Univ.)
ONO Fumihisa IJ\ ~ X j.... (Dept. Phys., Okayama Univ.)
PICHL Lukas(Dept. Comput . Software, Univ. Aizu)
QU Yi-Zhi Jffi
- ~ (Univ. Sci. Technol. China, China)
ROSMEJ Frank B.
(GSI, Germany)
SAKAI Akio t& it BE(Vacuum Products Co.)
SATO Hiroshi it ~ ¥15 9: (Fac. Sci., Ochanomizu Univ.)
SCHUCH Reinhold H.
(Stockholm Univ., Sweden)
SCHUESSLER Hans A.
(Texas A & M Univ. , USA)SHIMA Kunihiro ~f~ tf!J:(Tandem Accel. Cen., Univ. Tsukuba)
SHIMAKURA Noriyuki ~ ~ *2. Z (Fac. Sci. , Niigata Univ.)
TONUMA Tadao p iB iE 1lft (Adv. Res. Inst. Sci. Eng. , Waseda Univ.)
TORI! Hiroyuki ,~m Jf Z (Grad. Sch. Arts Sci., Univ. Tokyo)
TOSHIMA Nobuyuki p ~,~ 1~ ¥(Inst. Appl. Phys. , Univ. Tsukuba)
TSUCHIDA Hidetsugu ± E8 Jij(Fac. Sci., Nara Women's Univ.)
UEDA Kiyoshi J:. 83?~(Inst. Multidiscip. Res. Adv. Mater., Tohoku Univ.)(Dept. Appl. Phys. Chern., Univ. Electro-Commun.)
WATANABE Shinichi iJi illi~ YAGISHITA Akira WP T
I3jj
(KEK)
YOSHIDA Yutaka -ff E8~(Shizuoka Inst. Sci. Technol.)
YOSHIKI FRANZEN Ken(Grad. Sch. Arts Sci., Univ. Tokyo)
ZOU Yarning(Shanghai Jiao Tong Univ., China)

*

*

*

Trainees
ARIKAWA Kazuhiro ~ )1 \ *0 11; (Grad. Sch. Sci. , Shizuoka Inst. Sci. Technol.)
CHEN Fanfu lit~JL(Dept. Phys. , Grad. Sch. Sci. , Rikkyo Univ.)
GHADA H. Machtoub(Dept. Appl. Phys. Chern., Univ. Electro-Commun.)
HAMATANI Yuutarou il~t{j1P-!i!~ (Dept. Phys. , Okayama Univ.)
KANEKO Manabu$(Grad. Sch. Sci., Shizuoka Inst. Sci. Technol.)
KURODA Naofumi ~ 83 II 9: (Dept . Phys. , Grad. Sch. Sci ., Univ. Tokyo)
MAJIMA Takuya rs, ~~ 111 -tiL (Grad. Sch. Eng. , Kyoto Univ.)
MIZOGUCHI Satoshi i~ 0~
(Grad. Sch. Sci. Eng., Sophia Univ.)
OGAWA Shigeru IJ\)I \(Grad. Sch. Sci., Shizuoka Inst. Sci. Technol.)
SAKAGUTI Syuiti t& 0 11~ (Grad. Sch. Sci. Eng., Saitama Univ.)
SATO Hiroyuki it ~ r~ 11" (Fac. Eng. , Iwate Univ.)
SATO Yasuhiro it ~ r-G r.t (Dept. Phys. , Grad. Sch. Sci., Univ. Tokyo)
SHIMADA Hiroyuki ~ E8 tt 11" (Dept. Phys., Grad. Sch. Sci., Univ. Tokyo)
SONODA Tetsu [I] 83=fg" (Grad. Sch. Sci., Tohoku Univ.)
TAKABAYASHI Yuichi r'aJ;{t 1lft (Dept. Phys. , Grad. Sch. Sci., Univ. Tokyo)
WATANABE Satoko iJi it Wt:.:r (Grad. Sch. Sci. Eng., Saitama Univ.)

*

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Muon Science Laboratory
Head
NAG AMINE Kanetada

7k ~ ~ I~'

M embers
ISHIDA Katsuhiko E 83 ~ ~MATSUDA Yasuyuki t~ E8¥o KAM OTO Toshifumi lUi] fit 9:
WATANABE Isao iJi it J3J tit:m*Visiting Members
ADACHI Tadashi

370

JE rL

llE

KOYAMA Akio IJ\ LlJ BE tit
MATSUZAKI Teiichiro t~~f~m!i!~STRASSER Patrick
YAMASE Hiroyuki ill~! tf!J: Z(Fac. Eng. , Tohoku Univ.)

ADROJA Devashibhai(Fac. Sci., Hiroshima Univ.)
AJIRO Yoshitami *~ it 7i.B: (Fac. Sci., Kyushu Univ.)
AKIMITSU Jun f1< 7t(ColI. Sci. Eng., Aoyama Gakuin Univ.)
AKOSHIMA Megumi ~iiJr~&') ( ' J-;.. (Fac. Eng., Tohoku Univ.)
ARAI Juichiro *Jf#m-e~ (Tokyo Univ. Sci.)
AWAGA Kunio ~iiJ1~~~~:1;: (Gard. Sch. Arts Sci., Univ. Tokyo)
BAKULE Pavel
(Rutherford Appleton Lab. , UK)(Inst. Theor. Exp. Phys., Russia)
BOGDANOVA N. Ludmila
BRIERRE Tina M.
(KEK)
DAS Prasad Tara
(Dept. Phys., State Univ. New York, Albany, USA)FLEMING D.
(TRIUMF , Canada)
FUJII Yutaka Ji #(Fac. Eng. , Fukui Univ.)
FUJITA Masaki Ji 83 ~ £(Inst. Chern. Res., Kyoto Univ.)
FUKAYA Atsuko~X(Columbia Univ., USA)
FUKUSHIMA Kenji ti ~ ~HAGIWARA Makoto ~)Jj(
J[ (Fac. Eng. Design, Kyoto lnst. Technol.)
HIGEMOTO Wataru f~
E!.
(KEK)
HONDA Morihiro
83 ~ rt. (Inst. Cosmic Ray Res. , Univ. Tokyo)
HIYAMA Emiko ~~LlJwj(~r (KEK)
IKEDA Susumu it!! 83
Jl (KEK)ITO Atsuko 1]1' Ji /!j: -T
IWASAKI Masahiko :E ~~ ~ ~ (Dept . Phys ., Tokyo Inst. Technol.)
KADONO Ryosuke r~ 'f .N. ~ (KEK)
KAMIMURA Masayasu L ft iE(Fac. Sci., Kyushu Univ.)
KATO Mineo JJO Ji ~ ~ (Tokai Res. Estab., JAERI)
KAWAMURA Naritoshi iilJ ft px ~ (KEK)
KINO Yasushi'f(Fac. Sci., Tohoku Univ.)
KOIKE Takahisa IJ\ ¥ill .. ~ (KEK)
KOIKE Youji IJ\ ¥ill ?$(Fac. Eng., Tohoku Univ.)
KRAVTSOV Andrey(Russ. Fed. Nucl. Cen., Russia)
KUNO Yoshitaka ~ 'f .N."# (KEK)
MACRAE Roderick M.
(Notre Dame Radiat. Lab. , USA)
MAKIMURA Syunsuke 4X ft 1~ WJ (KEK)
MARUTA Goro 1L 83 'I'! ~~ (KEK)
MEKATA Mamoru § 15~
(Fac. Eng., Fukui Univ.)(Petersburg Nucl. Phys. lnst., Russia)
MIKHAILOV A.
MINAMISONO Tadanori f¥j rnI ,liP, ~ Ij (Fac. Sci. , Osaka Univ.)
MIYAKE Yasuhiro =: ~
t~
(KEK)
t~ 1=
(Fac. Sci., Osaka Univ.)
MIYAKO Yoshihito tf~
MOCHIKU Takashi~ ±(Natl. Res. lnst. Metals)
NAKAMURA Satoshi N. $ i'1'~
(Fac. Sci. , Tohoku Univ.)
NAKANO Takehito $ 'f -ffi 1= (Fac. Sci., Osaka Univ.)
NISHIDA Nobuhiko j§ 83 18' ~ (Fac. Sci., Tokyo Inst. Technol.)NISHIYAMA Kusuo j§ LlJ ~ ~ (KEK)NOZUE Yasuo 'f~:1;:(Fac. Sci., Osaka Univ.)
PEREVOZCHIKOV V. V.
(Inst. Theor. Exp. Phys. , Russia)
PONOMAREV Leonid I.
(Kurchatov lnst., Russia)
PRATT Francis L.
(Rutherford Appleton Lab. , UK)
SAKAMOTO Shinichi ±R 5C ~ (KEK)
SATO Kazuhiko 16": Ji - ~ (Fac. Sci., Saitama Univ.)
SHIMOMURA Koichiro Ti'1'¥~-fm (KEK)
SOLOVJEW E.
(Univ. Skopja, Russia)
STORCHAK Vyacheslav G.
(Kurchatov Inst. , Russia)
SUGAI Hiroyuki ~Jt J! 1i 11' (Tokai Res. Estab., JAERI)
TAKABATAKE Toshiro ~ ~ ~ e~ (Grad. Sch . Adv. Sci. Matter, Hiroshima Univ.)
TAKEDA Keiji m: B3 § PJ (Hokkaido Univ.)
TAKIGAWA Masashi ~[J II
1= (Inst. Solid State Phys.)

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TANASE Masakazu 1M i~j iE ~O (Tokai Res. Estab., JAERI)TOLSTIKHINE O.
(Kurchatov Inst., Russia)
TORIKAI Eiko ,~Jt B;J(
(Fac. Eng., Yamanashi Univ.)
TOYODA Akihisa :a fE :Yb fA (KEK)
UEDA Kazuo 1:. B3 ~O ~ (Inst. Solid State Phys.)
UMEO Kazunori t~ fit. ~O ~Ij (Fac. Sci., Hiroshima Univ.)
WADA Nobuo ~O B3 1~ it (Grad. Sch. Arts Sci., Univ. Tokyo)
WATANABE Tsutomu ill 1tB
1] (Int. Chr. Univ.)=* YAGI Eiichi }\YAMADA Kazuyoshi LlJ B3 ~O 7i (Inst. Chern. Res. , Kyoto Univ.)
YUKHIMCHUK A. A.
(Russ. Fed. Nucl. Cen., Russia)r*Trainees
MIYADERA Haruo
TANAKA Hiroyuki(Grad. Sch. , Univ. Tokyo)(Grad. Sch., Nagoya Univ.)

Beam Physics and Engineering Laboratory

Head
KATAYAMA Takeshi

h LlJ ffi: FlJ

Members
FUKUDA Naoki t~ B3 J1[ 1M
KOSEKI Tadashi IJ\ rMJ
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NAKAMURA Masato l:/=l tt 1= 1f
OKAMURA Masahiro IffiJ tt ~ 1i
SAKUMI Akira 1t ~Sj]
TAMBA Moritake Tt 111 ~I ffi:
YANAGISAWA Yoshiyuki tgp i*
YUN Chong-Cheoul jI"~l tg.a 11'HAMAGAKI Manabu i~ f.:§:KUMAGAI Keiko ~~:a- tt
NISHIURA Naoki W?m iE Jt
OZAWA Shuichi IJ\ i* 11~ TAKANAKA Masao ~ 1$ 1& it
WATANABE Tamaki ill jI~
YOKKAICHI Satoshi 1mBm H}rVisiting Members
AMEMIYA Hiroshi f:f:j g
1i
CHIBA Yoshiaki T ~ ~t Sj]
DIKANSKI Nikolai(Budka Inst. Nucl. Phys. , Russia)
HARA Tamio.§'; ~ (Toyota Technol. Inst.)
iff (Canon Inc.)HASHIMOTO Yuichi tl
HATTORI Toshiyuki m~ 1tB 1& ¥(Res. Lab. Nucl. React., Tokyo Inst. Technol.)(Univ. Colorado, USA)JAMESON Robert
KAMETANI Souichiro 1l:a-~~-~Ji (CNS, Univ. Tokyo)
KATO Shigeki 110 Ii tt Jt (KEK)
MATSUMOTO Takashi tl 5C .. ;it (CNS, Univ. Tokyo)
MICHIMASA Shin'ichiro JE!iE*Jf-f!~ (CNS, Univ. Tokyo)
MIYAZAKI Hirofumi g i1J~ i$)( (Sumitomo Heavy Ind., Ltd.)OGAWA Masao IJ\)II ~ ~ (Tokyo Inst. Technol.)
OGURI Yoshiyuki IJ\ ~ ~ Z (Res. Lab. Nucl. React., Tokyo Inst. Technol.)
OKAZAKI Kiyohiko lRiJiIJ~¥~.ltil
SAKAKIBARA Takeshi m/lUll](Chuo Univ.)(Nichimen Co.)
SAKAMOTO Yuichi :1:&
SERATA Masaki tit &fE~* (Coll. Sci., Rikkyo Univ.)
SIDORIN Anatoly(J.I.N.R., Russia)
SUGn Kazuo Ifb #- - ~ (Osaka Vacuum, Ltd.)SYRESIN Evgeny(J.I.N.R., Russia)
TAKANO Motonobu ~ H 5C 1~
TAKEUCHI Takeshi tt r*J
11E (CNS, Univ. Tokyo)
TSUTSUI Hiroshi MJ #- 1ft ± (Sumitomo Heavy Ind., Ltd.)TUCHIYA Masao ± ~ ~q ~ (Ishikawajima-Harima Heavy Ind. , Ltd.)'*** a'* -

'372

YAMAKAWA Koji LlJ )11 ~ RJ (Irie Koken Co. Ltd.)YANO Katsuki~ M} %YUKITAKE Mitsuteru § it 7t *l (Hitachi, Ltd)XIAO Meiqin ~~ ¥(Fermi N atl. Accel. Lab., USA)FUCHI Yoshihide 1tU
H(KEK)FULOP Zsolt(ATOMKI, Hungary)
GALSTER Wilfried(CNS, Univ. Tokyo)
HAMAGAKI Hideki ?~ j:~
1M (CNS, Univ. Tokyo)
HIRANO Midori ~~h- c" V)(CNS, Univ. Tokyo)
IWASAKI Hironori ~ UJ~ ~L. ~ (CNS, Univ. Tokyo)
KATO Seigo 1Jo Ri ijf:g. (Yamagata Univ.)
KOHNO Kiyoji iPJ ~ i~
(CNS, Univ. Tokyo)
KUBONO Shigeru j,J;*~ tt.. (CNS, Univ. Tokyo)
KUBOTA Shogo 0..1~B3J§:g. (CNS, Univ. Tokyo)
MIYACHI Takashi '8 ±t!1
-4 (CNS, Univ. Tokyo)
NAKANO Joe 9 ~B!l (CNS, Univ. Tokyo)
NOTANI Masahiro ~ ~ ~q. rt (CNS, Univ. Tokyo)
OHSHIRO Yukimitsu~ ¥ 7t(CNS, Univ. Tokyo)
11 (CNS, Univ. Tokyo)
OYAMA Ken *!lJ
OZAWA Kyoichiro IJ'\¥R~ -f! ~ (CNS , Univ. Tokyo)
SAKAGUCHI Takao ~ 0 • ~(CNS, Univ. Tokyo)
SATO Yoshiteru 1t Ri ~ *l (CNS, Univ. Tokyo)
SHIMOKOSHI Fumio ;f:Ij ~ X 7c (CNS, Univ. Tokyo)
SHIMOURA Susumu T?m!'? (CNS, Univ . Tokyo)
TAKAKU Seisaku ~ 0.. 1~ ft (CNS, Univ. Tokyo)
TANAKA Masahiko B3 9=' ~ ~ (KEK)TERANISHI Takashi ~ ~~(CNS, Univ. Tokyo)
UESAKA Meiko 1::. ~ ~ T(CNS, Univ. Tokyo)
WATANABE Shin-ichi iJi ill f$ (CNS , Univ. Tokyo)
YAMAZAKI Norio !lJ UJ~ ~ iJ 7c (CNS, Univ. Tokyo)

*

*

"*

'*

*

*

Trainees
NISHIMOTO Takeshi ~lEt 51: (Res. Lab. Nucl. React ., Tokyo Inst. Technol.)
ISOBE Tadaaki fit fm ,[" BE (Waseda Univ.)
KATO Koichi 1Jo Ri 0. (Waseda Univ.)
LEE Ju Hahn
1.3: i~ (Chung-Ang Univ. , Korea)
NANJYO Hajime 1¥J 11*~Ij(Univ. Tokyo)
OTA Shinsuke
B3(Kyoto Univ.)
TAMAI Munetaka ± #-4 (Waseda Univ.)
UE Koji 1::.
t15
(CNS, Univ. Tokyo)** 1lf.m*=

Cellular & Molecular Biology Laboratory
Head
SHIBATA Takehiko ~ B3 lEt ~Members
LIN G Feng

i$t.

1Jlt

Cellular Physiology Laboratory
Head
HANAOKA Fumio Tt. I1¥iJ X iLl
M embers
YATAGAI Fumio~B3J'!X7c373

Visiting Members
ANDO Koichi 1; Ii J1J. (N atl. Inst. Radiol. Sci.)
FURUSAWA Yoshiya ~ i'it t!1 (Natl. Inst. Radiol. Sci.)
HAMA Yoshimasa i~~ J§(Sci. Eng. Res. Lab., Waseda Univ.)
HASE Yoshihiro -& ~ *r!! 7i. (Takasaki Rad. Chern. Res. Estab., JAERI)HOSHINO Kazuo £ ~ (Natl. lnst. Radiol. Sci.)
ITO Hisao i¥
IJ\ ~ (Sch. Med. , Chiba Univ.)
ITSUKAICHI Hiromi 11. B l} 0 h(N atl. lnst. Radiol. Sci.)
KANAI Tatsuaki i::#- Jll3jJ (Natl. lnst. Radiol. Sci.)
KASAl Kiyomi !i: # i~ ~ (Natl. Inst. Radiol. Sci.)
KAWACHI Kiyomitsu iar I*J i~ 7t (Natl. Inst. Radiol. Sci.)
KOBAYASHI Yasuhiko IJ, iI:,t ~ ~ (Takasaki Rad. Chern. Res. Estab., JAERI)
MATSUFUJI Naruhiro f]} ik- nX:?.t. (Natl. lnst. Radiol. Sci.)MINOHARA Shinichi ~ 1* i$ (Natl. Inst. Radiol. Sci.)
MURAKAMI Masahiro ift J:. iE?.t. (N atl. Inst. Radiol. Sci.)
SAITO Mizuho 1f Ii liM ~ (Natl. lnst. Radiol. Sci.)
SASAKI Hiroshi 1t4~.t.
(Fac. Med., Kyushu Univ.)
SHIKAZONO Naoya Jf[ III @: ~ (Takasaki Rad. Chern. Res. Estab., JAERI)
SOGA Fuminori ~ fit X Eif (Inst. Nucl. Study, Univ. Tokyo)
TANAKA Atsushi EB I:fJ"{!f- (Takasaki Rad. Chern. Res. Estab. , JAERI)
TOMURA Hiromi Y'i- # ¥~ ~ (Natl. lnst. Radiol. Sci.)
WATANABE Masami ill ill iE C (Fac. Pharm., Nagasaki Univ.)
YAMASHITA Shoji LlJ r J§
(Natl. Saitama Hospital)

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Trainees
LI Ryonpha

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(N atl. lnst. Radiol. Sci.)

Plant Functions Laboratory

Head
YOSHIDA Shigeo

E ffi tt :513

Members
ABE Tomoko ~ilJ fm
SAKAMOTO Koichi
MIYAZAWA Yutaka*0 r~::$: i~­g tR

MATSUYAMA Tomoki t~ LlJ *ol1t
FUJIWARA Makoto Ii rnl
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Visiting M embers
CHIN Chee-kok(Dept. Plant Sci. , Rutgers Univ. , USA)FURUKAWA Koji t!I}ll i~(Mukoyama Orchids Ltd.)HAMATANI Misako i~~~1t(Hiroshima City Agr. Forest. Promot. Cen.)
HARA Yasuhide rnly~(Kanagawa Inst. Agr. Sci.)
HONDA Ichiro ::$: ~ - ~~ (Natl. Agr. Res. Cen., Min. Agr. Forest. Fish.)
HORITA Mitsugu #ill EI3~(Hokkaido Green-bio lnst.)
KITAURA Takeo ~t?m ~ ~ (Kanagawa Inst. Agr. Sci.)
LILL Ross Edward(Crop & Food Research, New Zealand)
MIYOSHI Kazumitsu := E - 7t (Fac. Bioresour. Sci. , Akita Pref. Univ.)
SUZUKI Kenichi i~~(Suntory Ltd.)TOKUHARA Ken f~ rnl
J! (Dogashima Orchid Cen.)
YOSHIDA Takuji E ffi 115 PJ (Takii Seed Co., Ltd.)TSUJIMOTO Hisashi :it::$:~(Kihara Biol. Res. lnst. , Yokohama City Univ.)

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Trainees
KONOMI Yuki
SAITO Hiroyuki

374

Bf ~ it! ~2. (Fac. Sci. Tech., Tokyo Univ. Sci.)
1fli7i.z (Dep. Agr., Grad. Sch. Sci. Technol. , Niigata Univ.)

Microbial Toxicology Laboratory
Head
YAMAGUCHI Isarnu LlJ 0~
Members
MOTOYAMA Takayuki

* LlJ

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CYCLOTRON CENTER
Chief Scientist
YAN 0 Yasushige
fi' 1i: ~*-RIBF Project OfficeHead
YAN 0 Yasushige*- fi' 1i: ~M embers
DINH DANG Nguyen
INABE Naohito fffi:ill ~ A
KUBO Toshiyuki ~ 1* 11& ¥MINEMURA Toshiyuki
ft 1~ 1TWAKASUGI Masanori E t~ {§ 1~*

FUJII Shinichiro ni#*JT - ~~KIM Ka-hae ~it yg
MADOKORO Hideki rl3~ pJT;{tt
TAKEICHI Hiroshige tT
t-f ~YAMAJI Shuhei LlJ ~ {I~ :qz*mVisiting Members
ARAKAWA Kazuo JiE]l1 to ~ (Takasaki Rad. Chern. Res. Estab., JAERI)BANDYOPADHYAN Arup
(Var. Ener. Cycl. Cen. , India)
CHAKRABARTI Alok
(Var. Ener. Cycl. Cen., India)(Var. Ener. Cycl. Cen. , India)
CHATTOPADHYAY Subrata
FUJINAWA Tadashi jji)ft(Mitsubishi Electric Co. , Ltd.)FUJISHIMA Shiro jji ~ 9:. ~~ (Ishikawajirna-Harirna Heavy Ind. Co. , Ltd.)FUKUDA Mitsuhiro t~ ill 7t 1i (Takasaki Res. Estab. , JAERI)
HIASA Toshikazu B ¥}j 1~ (Surnitorno Heavy Ind. , Ltd.)HIRUMACHI Tarniko ~fllfT~~-T (Toshiba Corp.)
HONMA Toshihirorl3~ ff It(Natl. Inst. Radiol. Sci.)(Toshiba Corp.)
KAKUTANI Nobukazu jFJ ~ ~ p {I~ (Hitachi Ltd.)KIDO Syuuichi(Toshiba Corp.)
KOZU Hideo t$ if
KUMADA Masayuki !f~ ill )ft Z(N atl. Inst. Radiol. Sci.)
KUNO Kazuo ~ ff to tit (Mitsubishi Electric Co. , Ltd.)(Mitsubishi Electric Co., Ltd.)MASUNO Shin-ichi iirl: ~ A MASUOKA Toshikatu iirl: ItliJ i~ Jl9} (Hitachi Zosen Corp.)
MATSUI Ju-Mei t~ # ~ ~ (Mitsubishi Electric Co., Ltd.)MIRONOV Vladrnir(J.I.N.R. , Russia )MITSUMOTO Toshinori W 1~ ~ (Surnitorno Heavy Ind. , Ltd.)MORIKAWA Tetsuya ~ JII ~ -tQ
MOT ONAGA Shoushichi 7C 71<. BB -t;~~
NAKAZAWA Taro ~ ¥R
OHKAWA Tornohiro 7:.]11 ~ 1i (Mitsubishi Res. Inst. Inc.)OHTOMO Kiyotaka 7:. 1i:.
~i
(Surnitorno Heavy Ind. , Ltd.)SASAKI Mutsuko 1~4 *H~-=f
SHEN Caiwan(Inst. Theor. Phys. , China)
SIDORIN Anatoly(J .I.N.R. , Russia)
TOMINAKA Toshiharu ~ ~ tlj ¥E1 (Hitachi Ltd.)

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375

Beam Dynamics Division
Head
GOTO Akira 1& nif;Members

FUKUNISHI Nobuhisa t~ i!9 ~ ~OHNISHI Jun-ichi
i!9 *~SAKAMOTO Naruhiko :t&fflG &* *-KAMIGAITO Osamu L!.:gY''f.11~ ­OKUNO Hiroki ~ ~ It l1t
SUZUKI Naoki ~~Il ~*Visiting Members

FUJISAWA Takashi ni 1R f@j;t: (Natl. Inst. Radiol. Sci.)
FUJIWARA Ichiro ni J]( - ~~ (Dept. Econ. , Otemon Gakuin Univ.)
HYODO Toshio :% ~J[ f~:K (Grad. Sch. Arts Sci. , Univ. Tokyo)
7i -T (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
ITOH Yoshiko 1JJITOH Kazuya 1¥ ni to -tiL (Tandem Accel. Cen. , Univ. Tsukuba)~t(Cycl. Radioisot. Cen., Tohoku Univ.)
IWATA Ren :5 EEl
KAWAZU Akira iBJ if
If (Techno Riken Co., Ltd.)KURIHARA Toshikazu ~ Nt 1~ (KEK)(KEK)
MACHIDA Shinji IBJ ffi 'IJ!
MATSUO Junko tl ~ ~ -T (Yuuai Corp.)
MORI Yoshiharu ~
~ 15
(KEK)
Z (Grad. Sch. Arts Sci., Univ. Tokyo)
NAGASHIMA Yasuyuki -& Iil~NOZAKI Tadashi ~ Iil~lE (Purex Co.)OKAMURA Hiroyuki lit] tt "5t. Z (Dept . Phys. , Saitama Univ.)
SAITO Fuminori jf ni X fl~
SAITO Katsuhiko jf ni Jm & (Sumitomo Heavy Ind. , Ltd.)UESAKA Tomohiro L:IR 1J:. i$ (Dept. Phys. , Saitama Univ.)
VOROJTSOV Serguei(J.I.N.R. , Russia)

*

=

*

Trainees

IKEDA Takuichiro iillffi11J ~~ (Dept. Phys., Saitama Univ.)
ISHIKAWA Kazuhiro ::0 )11 to 71; (Dept. Phys., Saitama Univ.)
ITOH Keisuke 1JJ- ni ~ 11' (Dept. Phys. , Saitama Univ.)
ITOKAWA Sakutaro ifd IIU**~~ (Dept. Phys. , Saitama Univ.)
KAMIYA Junichiro t$ij.i~j-~~ (Grad. Sch. Sci. , Osaka Univ.)
KUDO Takashi I Ji
~i
(Dept. Phys. , Saitama Univ.)
KUMASAKA Hirokazu ~R:IR"5t. (Dept. Phys. , Saitama Univ.)
NISHIKAWA Jun i!9}11*~(Dept. Phys., Saitama Univ.)
SEKIGUCHI Kimiko 00 0 1= -T (Dept. Phys., Sch. Sci., Univ. Tokyo)
SUDA Kenji @[ ffi ~ Iffi~ (Dept. Phys. , Saitama Univ.)
SUZUKI Ryoko W'Pif?- -T (Dept. Phys. , Saitama Univ.)
i$ (Dept. Phys., Saitama Univ.)
YAMADA Hiroshi LiJ ffi*

Beam Technology Division
Head
KASE Masayuki 110 ?~j ~ Z
M embers

AKIYOSHI Hiromichi f;k E § 7E
FUJIMAKI Masaki ni ~ lE l1t
FUJITA Shin ni ffi$JT
ITO Sachiko 1¥ ni :tf: -T
KID ERA Masanori~ lE ~KOHARA Shigeo IJ\ J]( ~ :K
MASUDA Akiko ~ EEl J38 -T
NAGASE Makoto -& l~j
wx:

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376

BHATTACHARJEE Sudeep
FUJITA Jiro ni EEl~~
IKEZAWA Eiji iill 1R
KAGEYAMA Tadashi "J; LiJlE
KIMURA Kazuie
tt KOMIYAMA Misaki :i6 LiJ ~ U*
MORITA Kosuke ~ ffi r15 11'
NAKAGAWA Takahide 9=' }II q:. 7}ij

=

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OGIWARA Kiyoshi Me JJR
USHIDA Kiminori :It B3 1:;; 1Ji1.
YONEDA Akira :?IE: B3
jt

TANABE Toshiya B3:ill ~ t!L
YOKOUCHI Tadashi
1*1
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*

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Visiting Members
ABURAYA Takashi ¥8I ~
it (NASDA)
ANZAWA Osamu 1;: rR
fl~(NASDA)AOYAMA Kazuhiro W LlJ 5fD Jt (NASDA)
ARAI Nobuaki# fl~ J[, (Grad. Sch. Inf., Kyoto Univ.)
BABA Shinji ,~jJJi 1§:I;( (NASDA)
BIRI Sandor(ATOMKI, Hungary)
CHIBA Toshiya -+ ~ flj ~DEGUCHI Yasushi tB 0
(NASDA)
EFREMOV Andrei(J.I.N.R., Russia)
FURUSE Kaoru ti il¥ (NASDA)FUTAMI Yasuyuki
Je. Z (Natl. Inst. Radiol. Sci.)
GOKA Tateo 1i~:k:(NASDA)HATANAKA Kichiji ifE 9=' E is (RCNP, Osaka Univ.)
HATSUKAWA Yuichi fJJ}II &1 (Tokai Res. Estab. , JAERI)
HAYANO Ryugo S. !f- ti' fllJi (Fac. Sci. , Univ. Tokyo)
HEMMI Masatake ~ ~ i& lEt
HIEDA Kohtaro ttttJ't*f2~ (ColI. Sci. , Rikkyo Univ.)(NASDA)HIROSE Takayuki Jt 11 4- ¥HIROTA Teruo IJ: B3 ~l:k: (Toyo Denshi Keisoku Co ., Ltd)IDESAWA Masanori tB if JI 1e (Univ. Electro-Commun.)
IIDE Yoshiya §R tB =Jj sfri (NASDA)
no Seiji iN. f=§ B~(Sumitomo Heavy Ind., Ltd.)IKEZOE Hiroshi im i~
tt (Tokai Res. Estab. , JAERI)INAMUARA Takashi tiEi iff~(Warsaw Univ. , Poland)
ISHIZUKA Takeo 15
lEt ~ (Dept. Phys., Saitama Univ.)
IWAI Satoshi :E #~(Nucl. Dev. Co., Ltd)JEONG S. C.
(KEK)
KANAMORI Takashi i: ~(NASDA)KATAYAMA Ichiro h LlJ - f2~ (KEK)
KATSURAGAWA Hidetsugu tE)l 1 oo~ (Fac. Sci. , Toho Univ.)i~(Grad. Sch. Eng., Kyoto Univ.)
KAWAI Jyun iPJ %KUBOYAMA Satoshi jd*LlJ~P] (NASDA)
KUDO Hisaaki I Ii fA 8B (Fac. Sci. , Niigata Univ.)
KUROSAWA Tadahiro ~ if ,[!, ~J.,. (Electrotechn. Lab. , Agency Ind. Sci. Tech.)
LEE San-mu
ifEl Dt (Inst. Phys., Univ. Tsukuba)
MAKIHARA Akiko tJ!JJRBPJ2.-=f (NASDA)
MATSUDA Sumio 11 B3 *4!:k: (NASDA)
MATSUNAMI Noriaki tl 7~ *2. SA (Sch. Eng. Nagoya Univ.)
MATSUNO Kiyoshi 11 ti'(Fujiden Eng. Co., Ltd)
(Fac. Textile Sci. Tech., Shinshu Univ.)
MATSUSE Takehiro t111:t:
MECHTCHRIAKOV Nikolai(Inst. Theor. Phys., China)
MINAMISONO Tadanori /¥j III ,[I, ~Ij (Grad. Sch. Sci., Osaka Univ.)-tJ2 (KEK)MIYATAKE Hiroari '8 lEt
MIYAZAWA Yoshitoshi '8 rR it ~MURAKAMI Tetsuya iff 1:. :gr t!L (Grad. Sch. Sci., Kyoto Univ.)
NAGAI Yuki 71< # EI3 *2. (NASDA)
NAKAMURA Takashi 9=' iff raJ p] (Cycl. Radioisot. Cen. , Tohoku Univ.)
NAKAO Noriaki 9=' f=§ 1e E~ (KEK)
NEMOTO Norio tl~
1Ji1. ~ (NASDA)-7 (KEK)NOMURA Toru ~ iff
OHIRA Hideharu 1::. Sf(NASDA)OHTSUKI Tsutomu 1::. ijiJ.
(Lab. Nucl. Sci. , Tohoku Univ .)m** = "*

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*- *- ****-OHYA Jiro~~(NASDA)
III Y15 Z (NASDA)
OHZONO Hironobu
OISHI Koji
15 ::Yb fflim (Shimizu Construction Co., Ltd)OOTOMO Hiromitsu
1X i$ 7t (NASDA)
SAGARA Kenshi ~§.& ~ ~ (Pac. Sci., Kyushu Univ .)SAKAI Hideyuki i@~ iT(Dept. Phys., Sch. Sci., Univ. Tokyo)
SAKURAI Yutaka t* #1ft (Jyoho System Kenkyusho):Ell[ (Mitsubishi Res. Inst. Inc.)
SATO Osamu 1t iii
SEKINE Toshiaki ~;f~ 1~ Sjj (Takasaki Rad. Chern. Res. Estab., JAERI)
SHEN W.-Q.
(Shanghai Inst. Nucl. Res., China)
SHIBAMURA Eido ~ ft ~ ~ (NASDA)
11~(NASDA)SHIMADA Osamu lib ffi
SHINDO Hiroyuki *JT iii Y~ Z
(NASDA)*iI (Cycl. Radioisot. Cen., Tohoku Univ.)
SHINOZUKA Tsutomu ii:t~
SHIRKOV Grigori(J.I.N.R., Russia)
iar f;j is (NASDA)
SOMEKAWA Shuji
SUEKI Keisuke~ 11' (Pac. Sci., Tokyo Metrop. Univ.)~(KEK)
SUGAI Isao ;g #~f
(NASDA)SUGIYAMA Hiroki ~~ Lll
SUZUKI Masami ifJ
lE ~ (Irie Koken Co. Ltd.)~ 11;(Inst. Phys., Univ. Tsukuba)
TAGISHI Yoshihiro rn
TAKADA Norio ~ rn ~ ~ (NASDA)
TAKAGI Syunji ~1~ is(Mitsubishi Res. Inst. Inc.)(Electrotechn. Lab., Agency Ind. Sci. Tech.)
TOYOKAWA Hiroyuki -=- JlI ~L. Z~ Ij ¥(NASDA)TSUBAKI Noriyuki
1i (Nuclear Development Co., Ltd)UEHARA Takashi L m:~
(Dept. Phys., Grad. Sch. Sci., Nagoya Univ.)
URITANI Akira JR ~UTSUNOMIYA Hiroaki *t~8~L.~ (Fac. Sci., Konan Univ.)(Texas A&M Univ., USA)
WADA Ryoichi ~D 133 .& WASHIO Masakazu J; /it; 1J (Adv. Res. Inst. Sci. Eng., Waseda Univ.)
fj;
YAMAKI Tsutomu )\ ~YAMAZAKI Hirohito Lll UI~ Jt 1= (Lab. Nucl. Sci., Tohoku Univ.)
YOKOYAMA Ichiro tJi LlJ - ~~YOSHIOKA Yasuhiro E I1YiJ~L.
(NASDA)

*

* **
** **
*

'*

Trainees
FUJIMOTO Rintaro iii*~**~~ (Dept. Phys., Sch. Sci., Univ. Tokyo)~~ ~(ColI. Sci., Rikkyo Univ.)
GOMI Tomoko Ii
HIGURASHI Yoshihide B ~ 1-* ~ (ColI. Sci., Rikkyo Univ.)
Jt (Fac. Sci., Tohoku Univ.)
IWASE Hiroshi E i~
KAJI Daiya
7S ~ (Fac. Sci., Niigata Univ.)
KOBAYASHI Masataka IJ~..
(Adv. Res. Inst. Sci. Eng., Waseda Univ.)
KOSHIMIZU Masanori M; 7]( lE ~ (Dept. Eng., Grad. Sch. Eng., Univ. Tokyo)
MATSUYAMA Tadayoshi 1~ LlJ lE 1! (Fac. Sci., Tohoku Univ.)
MIYAKE Norio =: ~ ~~ 7c (Grad. Sch. Eng., Univ. Tokyo)
MORI Masakazu ~~ ~D(Adv. Res. Inst. Sci. Eng., Waseda Univ.)
NOMURA Masayoshi ff ft ~ 7i (Grad. Sch. Eng., Univ. Tokyo)
SASAKI Michiya 1t4 *~ttt (Grad. Sch. Sci., Tohoku Univ.)
IWJ (Dept. Eng., Grad. Sch. Eng., Univ. Tokyo)
UMEBAYASHI Rei t~ 1*
YONAI Shunsuke
1*11~ f,fJ
(Fac. Sci., Tohoku Univ.)

P*

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Radioisotope Technology Division
Head
YATAGAI Fumio ~rnJt)(7c

378

*-

Members
ENOMOTO Shuichi 11 /.$:TSUKADA Teruyo ±~ B3 :fb 1-t
HIRUNUMA Rieko ~£¥fjfljiIr

TAKAHASHI Kazuya
YAN AG IYA Takahiro

trt~
5fD -ili{~n ~ ~i*Visiting Members
DING Wenjun T)( 11[ (Inst. High Energy Phys., Chin. Acad. Sci., China)
GORDON Alasdair
7t (Adv. Sci. Res. Cen., JAERI)
HABA Hiromitsu ~~ j:~
KAGAWA Yasuhiro W 111(Toray Res. Cen. Inc.)
KATO Takesi 110 § lit PJ
KAWABE Kenji JII ill jf PJ (Kyoto Pharm. Univ.)
KAWATA Tetsuya 111 B3 ~ -ili (Sch. Med., Chiba Univ.)
tt (Fac. Med. Technol., Univ. Tokushima)
MAEZAWA Hiroshi WI
MORIMOTO Shigeko ~ /.$: If.
NAGAME Yuichiro 71< § ~iltr-~~ (Adv. Sci. Res. Cen., JAERI)
NAKANISI Tomoko~ 1X(Grad. Sch. Agr. Life Sci., Univ . Tokyo)(ColI. Ind. Technol. , Nihon Univ.)
OGURA Koichi Ij, ~ ild1 PAN Qiangyan iiI}
~m E
(Inst. Mod. Phys. , Chin. Acad. Sci ., China)
AMANO Ryohei 7( ff .E!.
(Fac. Med., Kanazawa Univ.)
HIMENO Seiichiro Y!lffIDOC -~~ (Sch. Pharm. Sci. , Kitasato Univ.)
INAGE Hiroko fIB ~ Jl
(Showa Women's Univ.)
MATSUMOTO Ken-ichiro t~/.$:~-~~ (Showa Pharm. Univ.)
MINAI Yoshitaka ~ ~ ft -1f:. (Cen. Art. Sci., Musashi Univ.)
lit z: (Dept. Living Sci., Kinki Univ., Toyooka Jr. ColI.)
MINAMI Takeshi f¥j
NABEKURA Tomohiro f~ ~ ~ ~L. (Fac. Pharm. Sci., Kinki Univ.)
NAKANISHI Yukiko 9J~EB*r (Showa Women's Univ.)
OGURA Yasumitsu Ij, ~7t (Fac. Pharm. Sci. , Chiba Univ.)
SAKURAI Hiromu f* it~L.
(Kyoto Pharm. Univ.)
SHIBATA Sadao ~ B3 ~ ~ (Natl. Inst. Radiol. Sci.)
J1j[ (Dept. Chern. , Grad. Sch. Sci. , Osaka Univ .)SHINOHARA Atsushi r~)Jj{
SUZUKI Hiroyuki ~iJ~L. 1T(RI Res. Cen., Chiba Univ.)
SUZUKI Kazuo ~iJ
5fO ~ (Fac. Pharm. Sci., Chiba Univ.)(Natl. Inst. Radiol. Sci.)TAGAMI Keiko B3 1::. ~TAKAHASHI Masaaki ~ trt .lE BE (ColI. Agr. , Osaka Pref. Univ.)
TAKAHASHI Yoshio ~ trt~(Fac. Sci. , Hiroshima Univ.)
TAKEDA Atsushi lit B3 J1j[ PJ (Sch. Pharm. Sci. , Shizuoka Univ .)TAMANO Haruna ~ ff
f¥j(Sch. Pharm. Sci., Shizuoka Univ.)
UCHIDA Shigeo I*J B3 irt ~ (Natl. Inst. Radiol. Sci.)
YAMASAKI Mineo LIJ ~~ ~~ ~ (Nara Med . Univ.)
71< ~Jik: A (Fac. Sci., Shizuoka Univ.)
YANAGA Makoto
YANG Yongfeng
71< ~~ (Inst. Mod. Phys. , Chin. Acad. Sci., China)
YASUI Hiroyuki $: it 1ft Z(Kyoto Pharm. Univ.)/L (Inst. High Energy Phys. , Chin. Acad. Sci., China)
ZHAO Yuliang iE11*"* r*

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Trainees
FUGONO Jun ~ ff
*l!! (Kyoto Pharm. Univ.)
FURUKAWA Jun r5]11*l!! (Grad . Sch. Agr. Life Sci., Univ . Tokyo)
GOTO Sachiko 1~iii1t~r (Fac. Pharm. Sci., Nagasaki Univ.)
IGARASHI Kaori n-tilW~ (Showa Women's Univ.)
IKEGAMI Hiromu illi 1::.
115 (Fac. Sci. Eng., Waseda Univ.)
KANAYAMA Yousuke i: LIJ i$ fr (Fac. Med. , Kanazawa Univ.)
KAWAMOTO Yumi )II /.$: :ff ~ (Fac. Sci., Shizuoka Univ .)KOIKE Mariko IJ'itjt~J1.r (Fac. Sci., Shizuoka Univ.)
MAETSU Hitomi WI if: 1= ~ (Fac. Sci., Shizuoka Univ.)
1J (Fac. Sci. Eng. , Waseda Univ .)MATSUO Tsutomu 11:- ~NAKAYAMA Akihiro q:t LIJ SJI ~L. (Kyoto Pharm. Univ.)

379

**

OGI Takanori Ij,
it ~OHYAMA Takuya
LlJ 11] ill (Fac. Sci. , Shizuoka Univ.)
OIDA Takashi ztEB~1109:. (Fac. Sci. , Shizuoka Univ.)
OKA Toshitaka I1YiJ•(Fac. Sci. Eng. , Waseda Univ.)
SHIOBARA Yamato tl mt *;to (Fac. Pharm. Sci. , Chiba Univ.)
TSUJI Takae :it-# t~ (Fac. Med. , Kanazawa Univ.)(Fac. Sci. Eng. , Waseda Univ.)
UCHIYAMA Junichi pq LlJ i~ YABUSHITA Yuko It T 1ft -T (Fac. Med. , Kanazawa Univ.)
YOSHIDA Shozo ~ EB BH(Nara Med. Univ.)*-=

Liquid Helium Service DivisionHead
YAN 0 Yasushige
ff 1i: ~*Members
IKEGAMI Kumio

MIn ~ :5'5

OTAKE Masao* t1' Mt
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Visiting Members
KATO Kenichi 110 jff 'if N AKAN 0 Kazushiro $ ff ;to :9&

ADVANCED ENGINEERING CENTER
Research Instruments Development Division
Head
SENOO Katsumi ~ ~ Sl C
Members
IKEGAMI Yuji illi I 1,b ~NOMIYA Yoshio ff g 7i it
SHIMODA Susumu ;ffi EB:ii
SUGAHARA Seigo rg mt lE :g.
URAl Teruo iii #~YAMADA Shogo LlJ EB 1£ :g.

KITSUN AI Tokuji t~ I*J 1~ F1JSHIGA Tsunenobu ;E=: ~ 1jt 1§"
SHIRAISHI Akira B D
Sjj
TAJIMA Norio EB ~ ~ ~WATANABE Tokuji rOC:ill 1~ ~s
YAMADA Yutaka LlJ EB-=-*"

Contracting Members
KANEKO Naoe i: -T Ii !!
KUBO Ushizo !A.. 1~ ft Ii.
MATSUMOTO Akira ;f'l::$:BE
NIIOKA Yuzo *Jf I1YiJ ~ ~SASAMOTO Tetsuji %:::$::gr F1J
TAKAHASHI Kiyoji r!§J;j£' i~
TOKIWA Saburo 1jt ti ~ fm
YAMAMOTO Sumio LlJ::$: ~ Mt=

CHARACTERIZATION CENTER
Surface Characterization Division
Head
IWAKI Masaya E
lE ~*Members
KOBAYASHI Tomohiro IJ,
WATANABE Kowashi rOC:ill

**

380

~D

i-+

/lfiJIJ

NAKAO Aikor:p ~ ~ -T

ADVANCED COMPUTING CENTER
Computational Science Division
HeadtX: Ill~ 1~ -EBISUZAKI Toshikazu*

Members
jj~~jtIITAKA Toshiaki
SHINKAI Hisaaki

YAMAMOTO Tomoyuki LlJ~D Z
MORISHITA Tetsuya ~ T 11& tIL• .& % 13~

Image Information Division
Head

SHIMIZU HirohikoMembers¥w 7.K 1ft m*

SATO Hiromi it ~ Jt i4ii:
TAKIZAWA Yoshiyuki 1rg i' It
KAWASAKI Yoshiya )II Ill~ ji tIL
IKEDA Kazuaki ith 83 - BE
M 0 RISHIMA Takahiro ~ ~~ ~i 1ft
SUZUKI Shun ~iJ

OTANI Chiko~ ~D iTOKU Takayuki ~~i Z
WATANABE Hiroshi iJi illt$
ADACHI Tomohiro ~:it ~ 7i.
SHIKI Shigetomo ;=t li!t nx: 1X
SAKAKI Naoto
~ A

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Visiting Members

KURAKADO Masahiko
SAKAI Kenji i@ #- fl~ F~ ~=

m

RIKEN BIORESOURCE CENTER
Experimental Animal Division
Head

Obata Yuichi

IJ\ rJt 1ft -Members

HIRAIWA Noriko ~ E ~ -=f
YOSHIDA-NORO Chikako ffg~D1JD-=f

IKE Fumio 7thfl~ ~YOSHIKI Atsushi 15*i~

RIKEN BNL Research Center
Head

LEE Tsung-Dao*l
SAMIOS Nicholas p. *2
EN'YO Hideto ~ W* A *3*1 Director, *2 Deputy Director, *3 Associate Director
Experimental
Group Leader

EN'YO Hideto

~ W

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Deputy Group Leader

BUNCE Gerry M.
Members

BAZILEVSKY Alexander
FIELDS Douglas Edward
GOTO Yuji 1~ ~ iii=

DESHPANDE Abhay
FOX Brendan
GROSS PERDEKA11P Matthias381

I CHIHARA Takashi m]Jjl~
KURITA Kazuyoshi ~ B3 *0 ~f
SAITO Naohito ~ Mi II A
WATANABE Yasushi iJi jI
EftVisiting Members
LANGE Jens Soren

KOBAYASHI Hideyuki IJ'\ iff ~ ¥MURATA Jiro :ft B3 *- e~
TAKETANI Atsushi tT ~~YOKKAICHI Satoshi [Ig B'I~m(BNL , USA)

TheoryGroup Leader
LEE Tsung-Dao
Deputy Group Leader
BALTZ Anthony J .

**Members
AOKI Yasumichi W 1:W: ~BOER Daniel
ITAKURA Kazunori *~ ~ ~ ~2.
NEMOTO Yukio tl¥ at
ORIGINOS Konstantinos
VOGELSANG Werner

BLUM Thomas
DAWSON Christopher
NARA Yasushi ~.&~NOAKI Jun-ichi ff fj( i$: SCHAFFNER-BElLI CH J urgen

Visiting Members
BASS Steffen A.
(Duke Univ. , USA)BODEKER Dietrich(Niels Bohr Inst. , Denmark)
GYULASSY Miklos(Columbia Univ. , USA)
JAFFE Robert L.
(Massachusetts Inst. Technol., USA)JEON Sangyong(McGill Univ. , Canada)
KUSENKO Alexander(Univ. California, Los Angels, USA)
MAWHINNEY Robert(Columbia Univ. , USA)SCHAEFER Thomas(State Univ. New York, Stony Brook, USA)SHURYAK Edward(State Univ. New York, Stony Brook, USA)
(Columbia Univ. , USA)SON Dam Thanh
STEPHANOV Mikhail A.
(Univ. Illinois, Chicago, USA)VAN KOLCK Ubirajara(Univ. Arizona, USA)
VENUGOPALAN Rajagopal(BNL, USA)WETTIG Tilo
(Yale Univ. , USA)
Administration
ESPOSITO Pamela
GREENBERG Rae
HEINZ Tammy Anne
ITO Taeko {7t Mi ~ji -T
Administrative Manag er
NODA Toshihito ff EEl 1~ A
Deputy Administrative Manager
H0 RIE Hironori #ill iI t-t ~RIKEN PLANT SCIENCE CENTER
Laboratory for Remediation Research
Head
YAMAGUCHI Isamu LlJ 0~382

Members
SOSHI Takayuki~ lltt ~i 11-

Safety Center
Head
SAWA Hiroshi

i*

7i:.

Members
FUKAZAWA Kunio i* ¥R 00
KAGAYA Satoru 110~~ 'I'!
KOBAYASHI Hiroshi IJ"
tf
SHIMAGAKI Masayuki ~~ ±l[ iE Z
UWAMINO Yoshitomo J: ~ ~ ~J3
YOSHIKI Hajime E ~~
~

a

**

'*

HARASAWA Kaoru¥R •KATO Hiroko 110 ~ tf r
MIYAGAWA Makoto g )/1 ~ 8
SHINOHARA Shigemi •DI:.
YAMAGISHI Nobuyasu LiJ J1t 18''* e.'*

383

AUTHOR INDEXABE Ryo~ilJ:g:B~

BOYLE Peter A.

5,266

209

ABE Tomoko~ilJ~B:tD-=f128, 129, 130, 131

BROOKS Melynda L.

ABE Yasuhisa~ilJ:g:B$j...

29

BROWN B. Alex11, 12

231,232

ABUKI Hiroaki~ilJjEI;:*§ajj

192

BROWN David S.

228, 232

ADACHI Tadashi

)En-.

@.

104

BRUNER Nichelle

231,232~W-5fIj:7t

BUCHMANN Lothar

80

AKAGI Hiroyasu ~*~~ 5
AKAISHI Yoshinori ~E ~if.C 37

BUCURESCU Dorel

41

BUENKER Robert J.

83

AKIBA Yasuyuki f.:k~'*z 241
AKIYOSHI Hiromichi f.:k'2f§7E 53, 54, 55, 56, 58, 59,

BUNCE Gerry

AIHARA Toshimitsu

ALEKSEEV Igor

221, 226, 228

AMANO Ryohei~IDf.E!.f

AMAUDRUZ Pierre

80

AMEMIYA Hiroshi]:f:j'§

3, 251, 253, 254

CASARES Antonio

157

61, 62, 63, 71, 74, 262,

CEDERWALL Bo

41264, 285

CHAKRABARTY Dipak Ranjan
CHEN Dong

110, 111, 112, 113, 114, 116~

38

70, 74, 75, 76

W#~

ARIMA Akito

20, 21, 23:t!!!

fJt - ~B28

65, 77, 91, 107, 143, 145,
146, 151, 179.1~PJJJ:31;:}~,DHAWAN Satish

70, 71, 72, 74, 75, 76, 135,

DINH DANG Nguyen

137, 247

DOMBRADI Zsolt

222

DOSKOW Jack

204

EADES John

BATSOULI Sotiria
BAUMANN Thomas

BONCHE PaulELEKES Zolt
EN'YO Hideto

9!j:Ir~JC

20, 21, 22

49*:!t 18522139¥I)lI~*~

121

221
49
~~* A

216, 218, 220, 222, 224, 225,
226, 228, 236, 238, 240, 243,245

43207,211100

ENOMOTO Shuichi;fI**-

108, 109, 110, 111, 112,
113, 114, 115, 116, 117,
118, 119, 121, 122, 123,

16

BOYD Richard N.

EILERTS.Scott
218,219,220,243

221, 228

106

52

BHANG Hyoungchan
BOESTEN Ludwig

EGAWA Chie

159

57

49, 69, 70, 71, 72, 75,

226, 228

EATON Gordon H.

221

231

BAZILEVSKY Alexander

BLUM Thomas

DAWSON Chris 208
DEMICHI Kimihiko /:f1J]!1=m

43, 49, 53, 54, 57, 61, 69,

138

BEAUMEL Didier

244

50

DATAR Vivek Muralidhar

DONG Yu-Bing iii
DONG Zhihua 209

BASSALLECK Bernd

BAZIN Daniel

171

CRISTIAN Cailin 209
DANMURA Ayako Bj;j;;HfiJ-=f76, 169

221

BASS Steffen A.

244

224,225

DESHPANDE Abhay

BABA Hidetada

BAKULE Pavel

9J1~j!t!1

196

41

BARISH Kenneth

89

209

COURALLET Delphine

BAcK Torbjorn

BAI MeiCHRIST Norman H.

76~~:gjilr

BODEKER Dietrich:tD~,*5l

CHIMI Yasuhiro

CIANCIOLO Vince~.Ii~~jJA

42, 64, 67, 68, 164, 171

CHIBA Toshiya f-jj€5f1J ~ 264
CHIBA Yoshiaki f-jj€Hajj 268, 316

CHUJO Tatsuya

205

245

f-~~;f7E

61, 62, 63, 69, 70, 71, 73, 74, 75,

ARITOMO Yoshihiro
ASAHI Koichirof-~)llfiJVt

CHIBA J unsei

49, 52, 53, 54, 55, 56, 57, 58, 59,

W*1~d]!

AOKI Yasumichi

50

209

CHIBA Masami

ANDO Kozo ~JiilMliJ = 95,96
ANDO Yoshiaki ~ji~. 53, 55, 56, 58, 59, 62 , 69,
AOI Nori

216, 220, 221, 226, 228

32, 80179,247

ERMISCH Karsten
FULOP Zsolt

44

HARDTKE David H.

rIftJ 1lf-

ESUMI Shinichi

244

49, 55, 56, 58, 59, 60, 62, 63, 69, 70, 73, 74

FAMIANO Michael A.
FIELDS Douglas E.
FUJII Shinichiro

ii#~ - e~ii83 = e~

FUJITA Shin

ni83

57

:fit~6lD ~28

HASHIZUME Kazuaki
HATANAKA Kichiji

11285, 289, 291, 293

HATTORI Toshiyuki
HAYANO Ryugo S.

f~:I@J[H!IJ

41

fMlffirmI'5J 3, 5, 274, 283, 285 ,
287, 291, 293, 295,

FUKUYAMA Yoshimitsu~1l~~{3t$260

If.lff~li

82, 106~43** Il;jij 236, 238

HAYASHI Naoki

43, 49, 52, 57, 71, 72, 73, 74

182

im9=JE"?-El 174
HATANO Michio 1&:83ffj!l;;.lc 44, 45, 46, 148, 149, 174
HATSUDA Tetsuo :fJJ83=g:x 192

319, 321, 323

f~B3Il~t

FUKUNISHI Nobuhisaiit~)lli15--

178~

FUKUCHI Tomonoriiit~)l I Jf-

HASEGAWA Koichi
3,5,247,266

ii*~*e~ii~9::e~

FUJITA Jiro

FULTON Brian49, 69, 70, 71, 72,

HASEGAWA Kenichi

36

ii~iE;jij

FUJIMOTO Rintaro

FUKUDA Naokiiit~)l1115--

HASEGAWA Hirokazu

75,76, 169

221, 226, 228, 229, 231, 232
52

FUJISHIMA Shiro3, 262, 264

32, 80

FORTIER Simone
FUJIMAKI Masaki

204

iit~g:~rfrt$

HASEBE Hiroo

HAYASHI Takeshi

1ifil1]9::

B /;( ff if 242

HIBINO Masaru

B ~t$*HIGURASHI Yoshihide

53, 54, 55, 56, 58,

321

59, 61, 62, 63, 69,

fMWt$:7t 101, 141

70, 71, 73, 74, 75,

8076, 251, 253, 254
fittt*~

FUNAHASHI Haruhiko

245

HIMENO Seiichiro

ttlllffIDit - e~
~#-Jf

117

FURUKAWA Junil)1 1 *~ 118

HIRAI Kazuyoshi

FUTAKAMI Udai

=x.¥i*J 69, 70, 73, 74, 75, 76

HIRAI Masaaki~#iEaAHIRAI Masanori

f# iEiFC 52, 188

GACSI Zoltan

73

G ARA Alan209

G EISSEL Hans

flff=gJt 202

HIRANO Tetsufumi

82

GILG Hansjoerg

f~¥t~

HIRAO Norie

G ELBERG Adrian

49

JtJl ~~
Jtil~~

224, 225

HIROSE Shun-ichi

GLENN Woody

228

HIROTA Teruo
224, 225

103

18

JtB3*f:x 173!k!rBflJrIr

HIRUNUMA Rieko

108, 109, 114, 115,

liP*ml=f 49, 53, 54, 55, 56, 57, 58, 59,

GOMI Tomoko

116, 118, 121, 123,

61, 62, 63, 69, 70, 71, 72, 73,
74,75,76
GONO Yasuyuki~JlJt~Z~

f&ni

GOTO Akira

41, 77, 116, 179

3, 5, 102, 103, 140, 160, 247,

GOTO Yuji*ra'iE3'E 132
HONMA Michio *ra'J!!a 9, 10, 11, 12
HONMA Masamitsu
HOOVER Andrew232

HORAGUCHI Takuma

289, 291, 293, 295

HORI Masaki

f&ii1tt'r 133
i&iia= 188, 218, 220, 221, 222, 228,
236, 238, 240, 243

GROSSE PERDEKAMP Matthias
HABA Hiromitsu

247

272, 277, 279, 281, 285, 287,
GOTO Sachiko)]~~7.i:7t*

220, 222

123

HACHIYA Takashi !t~241
HAMAGAKI Hideki i;!:U.§:~;jij 78, 236, 238, 240, 242,

iliiJ OffiM

Wi

~;jij

106

HORITA Mitsugu#lii 83

jt

HORvATH Deszo

106

HOSHINO Masamitsu

#Ii:~

jlt

HUGHES Vernon

221, 226, 228

221, 226, 228

101

HUTTON Roger

96

245

HYODO Toshio~~JH~:x

182

IANCU Edmond

191

HAMATANI Yutaro

il~*fi~aJ]

89

ICHIHARA Takashi

HANAOKA Fumio:rEfIliJJtt$ 132

ii

131

HUANG Haixin
HUI Qin188£ff iE:7t 97

i~9=JJJO!

HAMANAKA Hiromi

179'I! 82

HIRENZAKI Satoru

GLENN Andrew

GOGIBERIDZE George

?fJ.

~i"~~

HIRASAWA Masahiko82

319, 323~fIliJHIRAOKA Nozomu

82

GILLITZER Albrecht

43
55, 56, 58, 59, 62mJJi(

102, 103, 140, 160¥

48, 176,225,228,236,
238, 240

#-=¥-D~iil

IDEGUCHI Eiji

*J.... IE iii 245

IEIRI Masaharu*:9iX~D~

IEKI Kazuo

IIDA Kei

71, 72, 73, 74, 75, 76,

115, 247

226, 228

i&83 :£ 31
itl!83 EB 43, 75, 76, 159

IKEDA Kiyomi

itl!83iff~

IKEDA Tokihiro

itl!83lJ;fi15- 314

13, 14, 18, 19.6f#l!-# LVf:iil

E83Mf~ISHIDA Katsuhiko

260
~I*J

JINNOUCHI Osamu
JOO Balint 209

fl~220, 228, 236, 238, 240

106

liillf@1r 88
KAGEYAMA Tadashi ~W IE 5,254,256,270
KAIHARA Jou JtJJi(£+ 65, 143, 145, 146
KAJI Daiya 1JDiil*~ 154
KAJINO Toshitaka ;fJllfffij!cl"

119

KAMBARA Tadashi

39, 138

KAMEDA Daisuke

E83 ,t! 48
ISHIDA Tomoyuki E 83 ~ Z 174
ISHIDA Yoshihisa E83ftj... 141, 157
ISHIHARA Masayasu EJJi(IE* 41,49, 52, 54, 55, 56,

42,66

199

33, 34~:a:-~-KAKUTANI Nobukazu

102, 103*f*~DZINUBUSHI Kazuyuki

JAMESON Robert A.

KAGEYAMA Kensuke

76, 91, 107, 143, 145, 146
INOUE Koji

jRJlI£l!m

JUHASZ Berti#ltf$IE 117

IMURA Nobumasa:fi831tz 55, 56, 58, 59, 62, 63

243
62, 63, 65, 69, 70, 71, 73, 75,

43,82

89

IZUMIKAWA Takuji

218, 221, 224, 225, 226, 228,

.6f#f$1¥J 49, 52, 53, 54, 57, 58, 59, 61,

IMAI Nobuaki:fili~*IWATA Yoshiyuki

JEON Sangyong

IKEGAMI Kumio itl!L:7L::::~ 285, 291
IKEZAWA Eiji itl!tR~= 3, 5, 247, 266:fiilJ~~~IWASAKI Masahiko
IWASE Akihiro

IKEDA Hiroshi

IMAI Ken'ichi

135, 137, 167

53, 54, 61, 62, 69, 70, 74, 75, 76

1i+m.~.

IGARASHI KaoriIGO George

59, 60, 61, 62, 63, 69, 70,

41

1$JJi( IE 88, 89, 93, 125, 141
1l83*,m- 65, 77, 91, 107, 143, 145,

ISHIDA Satoru

E#:@'f~

ISHIKAWA Norito

E JII

-~

~i

106

245

1$JJi(fN$ 231, 232*$:a:-i~-f!~

174
KANAI Yasuyuki :31£#1*z 88, 95, 96, 97, 141
KANAVETS Vadim 221,226,228:31£Wi$1r 110, 111, 112, 113:fIIJJJi(*~

KANBARA Akemi
KANDA Hiroki
KANEKO Emi

191,192114

1$ 831*~:t 245:31£.:r~~49

43~lfft$r· 49, 53, 54, 61, 69, 70, 71,

72,75,76

45, 46t[~~~GITAKURA Kazunori281, 285

KANNO Shoukot[:lRwrz 18, 19
t[litf@:t: 43, 82

ITAHASHI Kenta

3, 5, 247, 268, 272,

KANG Byoung Hwi

tf 5

ISUPOV Alexandre Yurievich
ITAGAKI Naoyuki

L:@j}fl~-

KANAYAMA Yousuke

213

ISHIKAWA Takashi

Elff~flHQ.

KAMIGAITO Osamu

KAMIYA Junichiro

EJIIMftlJ 109
EJI11tA 89

ISSHIKI Hiroshi

78, 242

KAMIHARA Nobuyuki

ISHIKAWA Katsutoshi

ISHINO Masaya

1l:a:-~~-!!}j70, 72, 73, 74, 75, 76,
221, 224, 228, 236,
ISHII Noriyoshi

146
KAMETANI Soichiro57, 58, 59, 62, 63, 69,

240

303,305

KANUNGO Rituparna24, 25, 42, 50, 64, 66, 67, 68,
164, 165, 171

KASE Masayuki

1JDli~z3, 5, 125, 132, 133, 135,

ITO Sachiko1¥Hi1$r 173, 319, 321, 323

137, 247, 251, 253, 254,

ITOH Akio

WHif.k~256, 262, 264, 266, 270,

1¥Hi~Dttt

ITOH Kc,tzuya S.

272, 274, 275, 283, 285,

48

WJlfJj:.:r 102, 103, 140, 160

ITOH Yoshiko

WHi~~

ITOU Masayoshi
IWAI Yoshio

93:fi#'&~

103

95

IWAKI Masaya:fi*IE~IWASA Naohito:fi1ft:wrc 53, 54, 55, 56, 58, 59, 61,

IWASAKI Hironori

314, 319, 323
KASHIYAMA Osamu:mW fl~ 41

KATAKURA Jun-ichi

Jt~*~ -KATAYAMA Ichiro

181

KATAYAMA Takeshi

JtW-f!~

J:lWm:m249
99, 100, 141
38,92, 234, 256, 258,

62, 63, 67, 68, 69, 70, 71,

260, 272, 275, 307,

72, 73, 74, 75, 76

308, 310, 314, 316:fiilJ~5h$

49, 52, 53, 54, 55, 56, 58,

KATAYAMA Takeshi

J:lWm:±

43

iii

1JaJirtiJe 44,45, 46

KATO Hiromitsu

KOIKE Yoji

IJ"ngi$= 104
IJ"ngrti~

KATO Mineo

1JaJi~~

39

KOIKE Yuji

KATO Seigo

1JaJim-~40, 135

KOJIMA Takao M.

KATO Sumio

1JaJi*iJ!:!1 244
132

KATO Tomomi

1JaJi~~

66

KONDO Yousuke

42, 64, 171

KONDRASHEV Sergei

JlllX~=KATORI Kenji

KOTCHENDA Leonid

KAWASAKI Hiroaki

KOURA Hiroyuki

39

KOWARI Ken-ichi

JIIH~~

66

i~~~i$ijt

49, 169

KAWAMURA Yoshie

KRASNITZ AlexKRISST Ray

KHARZEEV Dima

198

KIDERA Masanori*=i¥<iEfi: 3, 5, 247, 251, 253, 254,

128

224

+iiflJiz 26, 27

141?~Hfflt.

KAWAMURA Naritoshi

258

29

KOSENKO Grigory

108

JII.L*~KAWAKAMI Hirokane

Jli:Jii$1r- 49, 57~f~1:ti;f.2.

KONOMI Yuki

64, 154

JlljllJf~

KAWABE Kenji

KOMATSU Yu

JJi5[;$)\ 129, 130

KATSUMOTO Yukihisa

IJ"~Uit-

87

203

228

KUBO Kenya M.

)\f*~~KUBO Toshiyuld)\f*fit$ 41,49,52,57,69,70,73,

107
74, 75, 76, 141, 152, 177,

256, 270
KIENLE Paul82

KIKUCHI Jun~ng

297, 299, 301, 303, 305

KIM Changhoan

JI[~

78,242)\ f*mrKUBONO Shigeru

74, 135, 137, 156, 256,
274, 275

232

KIM Jungho

43

KIM Ka-Hae
KIM Seyong

~

ft~

~

tit1§:IJiJJi)\ 39

KUDO Katsuhisa

KUMAGAI Hidekazu ~~~~*D 52, 74
KUMAGAI Hiroshi ~~~ 7i:. 119

16
210*H-* 125*H%)\$ 66

KIMURA Kazuie
KIMURA Kikuo~~mrf~=KUMANO Shunzo
KUMAR Suresh

50

tx: JlI rti .A. 74

KINU G AWA Hiroto

~i

'*E8

KISHIDA Takashi~t~~9:
r~J!!f!I3~

KIYOMICHI Akio

244~

IJ,,;jt~$

140~E8*DHKUROKAWA Meiko"'Jllf!I3-=f 55,56,58,59,60,62,

220, 221, 225, 226, 228
63, 71, 72, 73, 135,75, 76
188,220,231,232

137, 167

IJ,,;jt Ji 55, 56, 58, 59, 62, 63

KUROKAWA Minako

KOBAYASHI Kiyoshi

IJ,,;jtr~z

KUROKI Yoshiaki
KUSAKA Kensuke

580, 162

KURITA Kazuyoshi

KOBAYASHI Hiroshi"'JII=~-=f75,76, 159"'*~BB

IJ"**~$

57

244
B Titft 50, 297, 299, 301, 303, 305
KUSAKABE Toshio B Tt}M~~ ' 105

IJ,,;jt~~

65, 77, 90, 91, 107, 143,

KUSENKO Alexander145, 146

KUSUMI Takaaki

KOBAYASHI Tomohiro
KOBAYASHI Toshio
KOBAYASHI Yoshio~E8 -"@;ft ~Ji~JJj(f~ -KURIHARA Toshikazu

245
97

IJ".!f'-JlI

KOBAYAKAWA Akira
KOBAYASHI Hideyuki

73, 74, 75, 76
KURATA-NISHIMURA Mizuki

41, 49, 77, 135~tD~BJt

KITAGUCHI Masaaki
KITAJIMA Masashi

188

KUMASAKA Hirokazu ~~~~~- 45,46, 174
KUNIBU Makoto ~5J' IDOC 53, 54, 61, 69, 70, 71, 72,

KIMURA Mineo *H*~ 83,105
KIMURA Shuichi *H11~- 115+;jt9:a7$ 7,181

KOBAYASHI-KOMIYAMA Misaki

IJ,,;jt-J6LlJ~P.:k)\ 11~ijt

177,

LADYGIN Vladimir Petrovich

266

LADYGINA Nadezhda Borisovna

228

LAINE Mikko

IJ"ili$:9;!: 23

LAURENT Henri

52

LAURET Jerome240

INJj(~~

KOIKE Shigetoshi

IJ"ngJl:iF 94
IJ"ng~f!13

3, 5, 272, 281
65, 143, 146, 151

129, 130KWIATKOWSKI Kris

KOEHLER Daniel
KOHARA Shigeo

197

3, 5,

KOHAMA AkihisaIV

Jl: 53, 54, 60, 61, 69, 70,

209

KIM DongJ 0

KOIKE Takaaki

95, 96

IJ";f1 fl 122

1JaJim:~tmJif~$

88, 98, 141

IJ"t&-fiJf - f!~

KOMAKI Ken-ichiro

KATO Takeshi
KATO Toshiyuki

189

IJ"~~i~

221

196

LEE David M.

231,232

LEITCH Mike

232

45,46
45,46

LEVKOVA Ludmila

72, 74, 75, 76,
135, 137, 156,

221

LEWIS BenjiLI Zheng

209

275

226, 228= ~fifnfi15

LIAO Xiadong

209

MIFUNE Tomoharu

LIM Heejoong

43

LIU Ming X.

231, 232

MIHARA Satoshi
MINEMURA Toshiyuki

LIU Zhong

M

,liP,

52

75,76

82
82

MIRGULE Ekanath Tanu

50

MITSUMOTO Toshinori

W:;t~~

287, 291

Fa'pJT3 HM
I

Mrn*~-f-

15

182
182

M rn MJ
Mrn¥£ 44,45,46,174
M7fC~

109

MIURA Motooki=oo5G~i43, 49, 57, 75, 76, 159

MIYAJIMA Akari

g ~ ~£43

MIYAKE Yasuhiro= ~*tf138

i*wiEi£ 188
MIYASHITA Takuya gT*-ill. 245
MIYAMA Masanori

MIYAZAKI Kiy:oshi gW~ ~ 129, 130
MIYAZAWA Yoshitoshi grR1t~ 281, 285, 291

226, 228:It*ffi:± 5

MAISON Jean-Marie52= HjK;]'g 65, 77, 91, 107, 143, 145,

MIYOSHI Hisanori

MAKDISI Yousef 221,226,228

146

tj;((Hf~M

MAKIMURA Shunsuke

138

MALAKHOV Alexandre Ivanovich
MAO Yajun'§nwi1!i-~rn*;fjt

MASUDA Hideki

MIZOI Yutaka

E8

~#-

it#- ii!r 72, 135, 156, 297, 299, 301,

45,46

224, 225

1[11[MARUYAMA Koichi
MASUI Hiroshi

277,279,281,285,

226, 228

MAETSU Hitomi
MAHLER George
MAlE Takeshi

49, 53, 54, 55, 56,
69, 70, 71, 73, 74,

MADOKORO Hideki

MAEDA Yukie*H1~1T58, 59, 61, 62, 63,

MUNZENBERG Gottfried

MAEDA Kuniko
MAEDA Masaru

121

245

221,226, 228

LUKYANOV Serguei M.

MACKAY William~

55, 56, 58, 59, 62, 63, 73, 75, 76

LOZOWSKI William
MUNCH Matthias='*

303, 305
7j(w~~i1!iMIZUSAKI Takahiro
40

244

MASUOKA Toshikatsu irl:1iGJ1~Mf
MATHEWS Grant 33, 34~}Hf-f-MOCHIZUKI Yuko

95, 96=€.flJ ~tf 98

MOMOTA Sadao

8rnft~~

tlrn:$¥ 39, 138

MORIKAWA Tetsuya

MATSUFURU Hideot~il*::*:MORIKAWA Tsuneyasu

t~~E8fi5f1J

MATSUO Yukari~?m~:J;-f-

MATSUURA Taeko

78,242

r1f 173

t~'f

MATSUNO Kiyoshi

213

tl:;tffi:$ 94

MATSUMOTO Takehiko~JI I 't.g*

MOROZOV Boris V.

41, 60, 135, 137

50, 64, 154, 161, 162~T;a-e~~83i1!i1r

MORITA Kosuke

285~*a:-f-

MORIMOTO Shigeko
MORISHITA Yuichiro75, 7653, 54, 61, 69, 70,~JII~-ill.

~*¥PJ

MORIMOTO Kouji

101, 141, 157

tlWffr-

MATSUYAMA Yuuichi U.

66

MORI Fumiko ~ 9=.-f- 119
MORII Toshiyuki ~#1~1T 185, 187307

t~5G.~

30

MOHRI Akihiro

MATSUDA Yasuyuki
MATSUMOTO Takashi

9, 10, 11, 12

132, 133
96

154

221

:;t*

MOTOBAYASHI Tohru~

49, 51, 52, 53, 54,
55, 56, 57, 58, 59,

71, 75, 76

MATSUZAKI Masayuki

t~w~ ~ Z

15

61, 62, 63, 69, 70,

MATSUZAKI Teiichiro~~tJnne~39, 138

71, 72, 73, 74, 75,

MAWHINNEY Robert D.

209

226,228

McGAHERN William
McLERRAN Larry

191 ,198

MENGONI Alberto

52-=

MOTOMURA Shinji:;tHf§"15 41, 116, 179
5G11f7j(~1f-

MOTOSHIMIZU Yosuke
258;w::;tftiJ[f 89ft Li1!iz 53,58,59,62,69,70,

MURAKAMI Tetsuya

ft L;tg-ill. 165,245

221

MIAKE Yasuo~*e~
MICHIMASA Shin'ichiro

89

MURAKAMI Hiroyuki

MUKUMOTO Yoshinori

MESCHERYAKOV Nickolay
MEYER Hans-Otto

76, 147, 169

74, 75, 76, 167, 169
244~lD~JT -e~

49, 53, 54, 60,
61 , 69, 70, 71,

MURATA Jiro Hrn*e~
MURPHY Alexander 80

65, 143, 146, 223, 231, 232v

MUTO Ryotaro ilkEi~*f!~ 245
NAGAE Tomofumi 7idI:mJt 43
7k§~~ - f!~

NAGAME Yuichiro

39, 104, 138

316

3*JfR - lE

OHKUMA Kazumasa

fitli Wit 3, 5, 266, 274

NAGASE Makoto**~ J'lrJ

OHKI Tomonori
123

7k~~,~,NAG AMINE Kanetada*JII~*OHKAWA Tomohiro

187

OHNISHI Hiroaki*iffi*~

244

OHNISHI Jun-ichi*iffi*~ -279, 285, 291, 295

NAGASHIMA Yasuyuki

fitm~*z

140, 160

OHNISHI Takeo

NAKAGAWA Takahide

J:j:lJII~3§:-

3,5,247,251,253,

OHNISHI Tetsuya*iffi:gr~

OHNUMA Hajime*m Ii 52

*im~:jc

254, 256, 258, 270

J:j:l#IWi-

NAKAI Yoichi

88, 93, 97, 141

J:j:lHlEf§ 221
NAKAMURA Satoshi N. J:j:l ft ;fg 39
NAKAMURA Takashi J:j:lft ... ;:t- 99, 100, 141
NAKAMURA Takashi J:j:lfHiPJ 43, 49, 52, 53, 54, 57,
NAKAMURA Masanobu

NAKAMURA Takeshi

270,275*ffi~)...
*ffi~i-5

1!fIHilk;:t- 319, 323

OHTA Shigemi*83i~~

209,210,211

J:j:lim~f-

118

181

OHTANI Shunsuke

95
17

108

222

OKABE Shigeto
OKADA Kensuke*~iff~i308

ffliJffBnX::t 18, 19
ffliJ 83~1l'- 222
ffliJffi~B*

OKADA Kunihiro*.& ~ 203
NARUKI Megumi nX:* ff- 245

99, 100, 141*llJ :t5) 141*llJ1tit!1 109, 247

OHYAMA Takuya

J:j:lllJ~5l

28*i:l-f~1r

OHTOMO Kiyotaka
OHYAMA Hitoshi

J:j:l:f9J 1f.

NAKATSUKASA Takashi
NANDI Basanta K.

*:9&;$:lt 135, 137, 156, 256,OHSHIRO Yukimitsu
OHTA Masahisa

J:j:limEl3*f- 115

NAKAYAMA Akihiro

OHSAKI Osamu *~~ iEi 303
OHSHIMA Nagayasu *~7k,,* 141

OHTA Ryuichi

J:j:l~lE~

NAKAO Masashi

161, 16576, 159

J:j:l~~f-

NAKAO Aiko44, 45, 46, 48, 64, 148,

61, 69, 70, 71, 72, 75,

NAKANISHI Tomoko M.
NAKANISHI Yukiko

49

99, 100, 141

NIIGAKI Megumi$Jf:l:~~

98

ffliJ83f§ = 43
OKAMOTO Ryoji ffliJ::$:.&iEi 36
OKAMURA Hiroyuki ffliJft5hZ 44, 45, 46, 48, 148, 174
OKAMURA Masahiro ffliJfH§* 234,258,260
OKUNO Hiroki J!IfJt:f1t 281, 285, 289, 291, 293, 295

NIIZEKI Takashi

$Jf ~

~i

48

OMORI Takashi

OKADA Shinji

N ARA Yasushi

44

NAYESTANAKI Nasser-Kalatar
NEWBY Jason

224,225NISHI Yuji iffi ~ = 32, 80, 159, 162
NISHIDA Minoru iffi 83 tt 5
NISHIKAWA Jun iffiJ1 1 ~ 44,45,46
NISHIMORI Nobuyuki

iffi~f§1T

NISHIMOTO Takeshi

iffi::$:ilk9: 92
iffiHf~ =NISHIMURA Shunjiiffi~fDZNISHIO Kazuyuki

NODA Koji

32, 67, 68, 80, 159, 16295

fffk?~-

1f83fjj:PJ

206

141
109

NOMACHI Masaharu ~~lIfJlEiEi 245
NOTANI Masahiro ff~~q.Jt 49, 60, 71, 72, 75, 76,
135, 137, 156, 275¥g83a~NUMATA Shigeo
ODAHARA Atsuko

5

OGAWA Hiroshi

Ij'\Jlltfffil~

OGAWA Shigeru;j...JII a~rnl

Ij'\~~Zvi

Ij'\If~t!1

244

212

ONO Masaya

211

ORGINOS Kostas*~7k,,*OTA Shinsuke*83~ijj

165

OTSU Hideaki*7f3lf;~48*~1f.iEi

90
7, 94, 182

9, 10, 11, 12, 16, 18, 19* llJ ~ 95*llJ -&t 78,242
OYAMA Satoshi *llJ ~~ 187
OYAMA Hitoshi
OYAMA KenOZAWA Akira

Ij'\~

OZAWA Kyoichiro

92

98

r.t\ffiiEi& 43

OUTA Haruhiko~~fDi*OZAWA Shuichi
PAN Qiangyan249:II 24,25,42,50,64,66,67,68,

65, 91, 107, 143, 145, 146i.

OGIWARA Kiyoshi
OGURI Yoshiyuki

89

ORGINOS Konstantinos

OYAMATSU Kazuhiro
41, 77

Ij'\83rnlWr

109

* 66

OTSUKA Takaharu

ffD~f-NOGUCHI Motoko~

ONISHI Takashi *~ONO Fumihisa IJ'\IfJt~

OSHIMA Nagayasu

imimlE-W 310

NISHIURA Masaki
NOAKI Jun-ichi

48*~.:E ff-f= 49

ONG Hooi Jin

159, 17178,242,245

Ij'\~~-f!~

Ij'\7'f~-

55,56, 58,59,62,63,258

il S!!g 75, 76, 179

PANITKIN Sergei Y.

204

*4

PATE Stephen

232

SASAKI Osamu
SASAKI Shoichi

PITA Santiago

52

SASAKI Takafumi

POUTISSOU Jean-Michel
POUTISSOU Renee

PRZEWOSKI Barbara
READ Ken

80

80
221

221

ROSER Thomas

221,226,228
221

RUSSO Thomas

*~Mf~

31

*~~q.~

43*Ei J! 244*Ei iW 65, 77, 91, 107, 143, 145, 146

SATOU Yoshiteru*Ei~~44, 45, 46, 48, 60, 135,

SAWADA Shin'ya

1i83~t!1

236,238,240

SCHAFFNER-BIELICH Jiirgen

228

SCHOTT Wolfgang~:t&7t;q-T

SAGISAKA Mitsuyuki
SAHIN Latife 80
SAITO Akito

ftEitf1F2. 220, 224, 225, 245

137, 174

RINCKEL Tom
RUSEK Adam

45, 46

179

SATO Hiroki D.

SATO Wataru

REZNIKOV Serguei Grigorievich

245
211

SATO Katsuhiko
SATO Susumu

226,228RESCIA Sergio

fl~*4*~fJt

SATO Masaharu

224, 225*ft4 *Mf-~~aA![

249

198

82

SCHUESSLER Hans A. 99
SCHAFER Thomas 200

ff- 23~49, 53, 54, 55, 57, 60, 61, 69,

SEKI Ryoichi

70, 71, 72, 73, 74, 75, 76, 135,

SEKIGUCHI Kimiko

137, 169

SEKIMOTO Michiko ~*~9lJr 245
SERATA Masaki t!tA83J{* 53,54,55,56,58,59,61,

SAITO Fuminori

ifjDtfl~140, 160

SAITO Naohito~~WIA

188, 218, 220, 221, 222, 224,

~Df=r62, 63, 69, 70, 71, 73, 75,

225, 226, 228, 231, 232, 236,
SAITO Takaaki

ifji~aA

SAITO Takashi
SAITOH Kohji

if ~

*

if~ii!PJ

SAKAGUCHI Takao

107
41~83~~f41

SHIBATA Toshi-Aki~83~IJEY3188, 231, 232

165

106

:t&DJt~78, 242

iE!i#9HT 44,45,46,48, 148, 149,

SAKAI Hideyuki

167, 174
SAKAI Kenji

iE!i#~=SAKAI Shingo:t&#~:g.

i:t *3 7J

SHEN Caiwan

SHIBATA Masataka:t&D i¥SAKAGUCHI Jun

258

44, 45, 46, 148, 174:t&DiE;~f

SAKAGUCHI Harutaka

76
SHARKOV Boris

240, 243

44,45,46,48,148,174

29~83~PJSHIMADA Kenji

65, 143, 146

SHIMAMURA Isao

~H

SHIMIZU Noritaka

i~Jk~IJ~~

rHii! - ~~SHIMOMURA Koichiro~rim

SHIMOURA Susumu

83,84,85,105
9
138

49, 53, 54, 55, 56, 58,

143, 146

59, 60, 61, 62, 63, 69,

244 ·70, 71, 72, 73, 74, 75,:t&*A:lii 319, 323:t&*-l! 119
SAKAMOTO Koichi Il&*ii!- 131
SAKAMOTO Hisao

76, 135, 137, 156, 167,

SAKAMOTO Kazunori

169

SAKAMOTO Naruhiko:t&*~~:i§83~*~~SAKODA Seitaro

44,45,46,48,148,
174, 268, 272, 277,

SOFF SvenSON Dam T.

44, 45, 46, 148*Ara'9::!J4. 245
SAKUMI Akira ft~ aA 92
SAKURAI Hiromu t;:# "5b. 108
SAKURAI Hiroyoshi tt#tffi 49, 52, 53, 54, 55, 56,
57, 58, 59, 61, 62, 63,

SAKURAI Yoshiharu

tt#BR~SAMANTA Chhanda

67,68

SANETO Ryuji

~~ll=

101

SMITH Braunen

281, 285
SAKUMA Fuminori

1illj{ J!1 123

SHINOHARA Atsushi
221

204
193

SONDHEIM Walter

231, 232

11183 ¥f 141

SONODA Tetsu

224,225

SORENSEN Soren
SOSHI Takayuki~JItl~fqT

SPINKA Harold

226, 228

STEPHANOV Mikhail

69, 70, 71, 72, 73, 74,

STRASSER Patrick

75,76

SUDA Kenji

103

SUDA Toshimi

127

201

138

~Jt83~ffli~

44, 45, 46, 148, 174 ·~Jt83~IJ~

40, 42, 64, 66, 67, 68, 154,
164, 165, 171

SUDOH Kazutaka~JUJi*D~186

VII

~Jiffil *1T

SUGAI Hiroyuki
SUGAI Isao

~#

~

~m~~

109

SUGANUMA Hideo

~rB~~

213

SUGAWARA Fumio~)jj{==~*TANASE Masakazu

177

TANIHATA Isao

;f~*

~

SUGIMOTO Satoru;f~*

Wg 13, 14

SUGIMOTO Takashi;f~*~ilH~~

24, 25, 32, 40, 42, 50, 64,
66, 67, 68, 80, 101, 147,
152, 154, 157, 159, 161,

43, 49, 57, 69, 70, 71,
72, 75, 76, 159

1±E7t1f- 33, 34, 35

SUZUKI Hideyuki

j1i*~Z33, 35SUZUKI Hiroyuki

j1i*~h1T

119

245

83 r:p~A 78
WiilE5fD 39

TANAKA Yoshito

128

SUGIMOTO Makoto*

38, 266, 307, 310

TANAKA Hiroshi 83 r:p
97
TANAKA Kazuhiro H. 83r:plJif:

262

SUGANUMA Hideo

SUMIYOSHI Kohsuke

83ill~itt

TANABE Toshiya

39

162, 164, 165, 171*~~83

TAROHDA Tohru~~

110, 111=.J::j[g j@j 52, 53, 54, 55, 56, 58,

TERANISHI Takashi

59, 60, 61, 62, 63, 135,

i1i*Jf- 129, 130
i1i*Jf= 36

137, 156, 274, 275

SUZUKI Ken-ichi
SUZUKI Kenji=.J::j[g~tf

TERANISHI Yoshiaki

84, 85SUZUKI Naoki

i1i*@:~

102, 103, 140

TERASAWA Mariko =.J::i'~~-=r 33,34
TERASHIMA Satoru =.J::1il~ ~D 165

SUZUKI Ryoko

i1i*iHt-=r45,46, 174

THOENNESSEN Michael

SUZUKI Ken

~1i*

~

82

i1i*~i~SUZUKI Takatoshi
SUZUKI Takeshi

i1i* •SUZUKI Toshio~1i*~~

43
42,66,67,68

THOMAS Timothy L.

221

THROWE Thomas G.

240

TOJO Junji20(i1i*) ~5fD-=r~.&

SUZUKI-NARA Miwako

244*:9&;}IIJUEi 220, 221, 226, 228
r~pt~.fij

TOKANAI Fuyuki

221, 226, 228

TOKI Hiroshi

SYPHERS Michael

221

TOMINAKA Toshiharu

SYRESIN Evgeny

31083)jj{RJ~

~

~if:

27
83

TORII Hisayuki
TOWELL Rusty

j@jtl£~

5

TSUCHIDA Hideo

TAKAHASHI Katsuhiko
TAKAHASHI Kazuya

j@jtt5fD-ili. 247

TAKAHASHI Kenichiro

7i1Mi.-~~

TAKAHASHI Yoshio

j@jfrjj&~

TAKAHASHI Yutaka

j@jfrjj

TAKANAKA Masao~f$i&!l104,~#~1T

232±83~~

TSUCHIDA Hidetsugu ±83~* 93
TSUCHIHASHI Takahiro ±frjj~itf 303
jj:

~tt

152

TSUKIORI Noritoshi

Jim.f~

5

312

TSURUOKA Hiroshi

1t,~IiliJ;f.ti±

244

TAKANO Motonobu

TSUTSUMI Tsuyoshi

TAKEDA Naoto

J@Jfl'5Cf§' 307
11'83i1!fz 165
ffi:83@:A 39

TSUTSUI Hiroshi

TAKEDA Hiroyuki
TAKESHITA Eri

11'r~~

53, 54, 61, 69, 70, 71, 72,

UCHIYAMA Akito

75,76

UE Koji

TAKETANI Atsushi

11'~

TAKEUCHI Hiroki

11' I*] ~h:fj 249

f,;j#rfi± 308~

IMlIJ~

L

I*]?' ~tmz

11'1*]TAMAI Munetaka::E.#*~TAMAMURA Toshiaki~iL

135, 137, 156, 275
UENO Hideki

Lfl'~1tt

65, 77, 91, 107, 143, 145, 146

L~::ti$44, 45, 46, 48, 148, 149,
174

UMETANI Shigeo~Jij:~ ~~UNDERWOOD David

258, 260

UNO Koichi*fl'i1!f- 277

URAl Teruo

im#~~

78,242
95

R:# ?¥ 44, 45, 46, 148, 149, 174

UTSUNO Yutaka

7,94*t~fl'UWAMINO Yoshitomo

122

221,226

71, 73, 74, 75, 76, 169::E.H~ 8B

44, 45, 46, 148

i1!f= 53, 54, 60, 61, 69, 70, 71, 72, 75, 76,

49, 53, 54, 55, 56, 58,

TAKEUCHI Takeshi

41

I*JLlJIl%1= 3

UESAKA Tomohiro

59, 61, 62, 63, 69, 70,viii112, 114

UCHIGASHIMA Nobuyuki

220, 221, 224, 225, 228,
231

TAMIl Atsushi

41

TSUJI Takae£i!..

TAKEUCHI Satoshi

218, 243

121.It!!.

:If(;

293, 295, ·303*

TO MONO Dai ::tfl'
43, 82TORII Hiroyuki A. ,~mJEz 96, 106

245

TACHIKAWA Masanori JtJlI1=$
TAJIMA Norio 83~$~ 94

TACHIBANA Takahiro

50, 161±dJt tf 13, 14, 35'i"r:pfljiE 234, 285, 289, 291,

SVIRIDA Dmitry N.

TABARU Tsuguchika

159~

10, 11

L~~~A

173, 319, 321, 323

van KOLCK Ubirajara

194

YAMAMOTO Kazuhiro

LlJ*f05h

221

195, 198, 203

YAMAMOTO Sukeyasu

LlJ*;f.i5~~

41

VILLATTE Laurence

224, 225

YAMAMOTO Tomoyuki

LlJ *~Z

86

VOGELSANG Werner

190

YAMANISHI Teruya

VENUGOPALAN Raju

fOEBiE!riJ

WADA Michiharu

99, 100, 141, 157

LlJi!B*ft!1

YAMAUCHI Hiromoto

WAKASA Tomotsugu;E=~*~Iffl~

44, 48, 174

YAMAZAKI Norio

WAKASUGI Masanori;E=;fb~~316

YAMAZAKI Toshimitsu

WAKUI Takashi

im#*;:t:

WALDEN Patrie

80

149

185

LlJl*J§j'f

LlJJlJ~HliJ7c3135, 137, 156, 274, 275

LlJJlJ~1j::7t

LlJ JlJ~*m

YAMAZAKI Yasunori

37, 82, 106
88,93,95,96,97,98,
141

WATANABE Gentaro illill5C::;t~~ 31
WATANABE Hiroshi Vijl Jl 41, 49, 65, 77, 91, 107,YANAGA Makoto 9;;:7kWiX.A 109
YANAGISAWA Yoshiyuki ;WPi*i!HT53, 54, 55, 56, 57,

143, 145, 146
WATANABE Ikuo

vtillfl~~310

WATANABE Isao

ill:ilJj]!i

104, 138

58, 59, 60, 61, 62,
63, 69, 70, 71, 72,

WATANABE Kiwamu

711ill~Z

57

73, 74, 75, 76,
135, 137, 156,

WATANABE Shin-ichi

illill1$-

135, 137, 156, 256,275

WATANABE Tamaki

711~

WATANABE Yasushi

V.tjl

WATANABE Yutaka X.
~

WEI Long

YANAGIYA Takahiro
YANG Yongfeng

238, 240

YANO Yasushige'* 176, 225, 228, 236,
ittillill

WEICK Hermut

82
209, 215

YANO Katsuki

7kJlJf;9;;:ffJm%

258

9;;:ff*~

3,5, 179,247,251,253,
254, 264, 272, 274, 277,
279, 281, 283, 285, 287,106

YASUI Hiroyuki*#ftiz108

YATAGAI Fumio~EBJt)(7c

YABANA Kazuhiro

1m B

YOKOUCHI Shigeru:f1l!l*J

YOKOYAMA Ichiro:f1l!LlJ-~~

240, 245

9;;:1£-i*9;;:~~ it17

182~rftiT110, 111, 113

YABUSHITA Yuko)\**- 94~~

YAIRI Satoshi9;;:A9;;:raJ~::;t~~1m:1J,*,,[

YONEDA Akira

*= EB

a

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5, 88, 154*=EBll-~~*57

107, 143, 145, 146
YONEYAMA Tetsu

122

YONGIL Kwon

53,54,55,56,58,59,

YOSHIDA Atsushi

73, 75, 76, 147
YAMADA Masami

LlJEBJm~

YAMADA Satoru

LlJEB

YAMADA Shoichi

LlJEB]j[-*LlJ

1!f 43,82

irEB

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232

YOSHIDA Koichi

15B3:7t-

YOSHIDA Shigeo

15B3a~

33,35

YOSHIDA Yutaka

irB3

107

YOSHIMI Akihiro

15 ~~i$

LlJEB,*i$

YAMAGUCHI Isamu

106

127

YOSHIMURA Yoshio
YOUNG Glenn

90
65,77,91, 143, 145, 146,

42,64,66,67,68,171

ZELEVINSKY Vladimir

YAMAGUCHI Yoshitaka

LlJ D EI3~

64, 66ZHANG Yuho
ZHAO Yu-Liang

15Hi!f~~245

224, 225

LlJDJtZ
23

128, 129, 130, 131

151

YAMAGUCHI Takayuki

LlJ Jmfl~f~209

LlJ D~1j:~50, 58, 59, 62, 63, 64, 66,
176, 177

LlJD2t?-::1~

LlJ D

64, 69, 70, 90, 141, 152,
154,176

27'IN 245YAMAGUCHI Hidetoshi

49, 52, 57, 65, 69, 70,
71, 73, 74, 75, 76, 91,

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ZHENG Tao~ZHOU Xiaohong
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